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Sample records for jani heikkil tiina

  1. Newman-Janis Algorithm Revisited

    NASA Astrophysics Data System (ADS)

    Brauer, O.; Camargo, H. A.; Socolovsky, M.

    2015-01-01

    The purpose of the present article is to show that the Newman-Janis and Newman et al algorithm used to derive the Kerr and Kerr-Newman metrics respectively, automatically leads to the extension of the initial non negative polar radial coordinate r to a cartesian coordinate running from to , thus introducing in a natural way the region in the above spacetimes. Using Boyer-Lindquist and ellipsoidal coordinates, we discuss some geometrical aspects of the positive and negative regions of , like horizons, ergosurfaces, and foliation structures

  2. Five-dimensional Janis-Newman algorithm

    NASA Astrophysics Data System (ADS)

    Erbin, Harold; Heurtier, Lucien

    2015-08-01

    The Janis-Newman algorithm has been shown to be successful in finding new stationary solutions of four-dimensional gravity. Attempts for a generalization to higher dimensions have already been found for the restricted cases with only one angular momentum. In this paper we propose an extension of this algorithm to five-dimensions with two angular momenta—using the prescription of Giampieri—through two specific examples, that are the Myers-Perry and BMPV black holes. We also discuss possible enlargements of our prescriptions to other dimensions and maximal number of angular momenta, and show how dimensions higher than six appear to be much more challenging to treat within this framework. Nonetheless this general algorithm provides a unification of the formulation in d=3,4,5 of the Janis-Newman algorithm, from which several examples are exposed, including the BTZ black hole.

  3. Group Dynamics in Janis's Theory of Groupthink: Backward and Forward.

    PubMed

    McCauley

    1998-02-01

    Janis's groupthink theory is an appealing explanation of how group process can get in the way of optimal decision making. Unfortunately, Janis was selective and not always consistent in his application of research in group dynamics. This paper traces groupthink to its theoretical roots in order to suggest how a broader and more consistent use of research in group dynamics can advance understanding of decision-making problems. In particular, the paper explores and reinterprets the groupthink prediction that poor decision making is most likely when group cohesion is based on the personal attractiveness of group members. Copyright 1998 Academic Press. PMID:9705800

  4. Deciphering and generalizing Demiański-Janis-Newman algorithm

    NASA Astrophysics Data System (ADS)

    Erbin, Harold

    2016-05-01

    In the case of vanishing cosmological constant, Demiański has shown that the Janis-Newman algorithm can be generalized in order to include a NUT charge and another parameter c, in addition to the angular momentum. Moreover it was proved that only a NUT charge can be added for non-vanishing cosmological constant. However despite the fact that the form of the coordinate transformations was obtained, it was not explained how to perform the complexification on the metric function, and the procedure does not follow directly from the usual Janis-Newman rules. The goal of our paper is threefold: explain the hidden assumptions of Demiański's analysis, generalize the computations to topological horizons (spherical and hyperbolic) and to charged solutions, and explain how to perform the complexification of the function. In particular we present a new solution which is an extension of the Demiański metric to hyperbolic horizons. These different results open the door to applications on (gauged) supergravity since they allow for a systematic application of the Demiański-Janis-Newman algorithm.

  5. An extension of the Newman-Janis algorithm

    NASA Astrophysics Data System (ADS)

    Keane, Aidan J.

    2014-08-01

    The Newman-Janis algorithm is supplemented with a null rotation and applied to the tensors of the Reissner-Nordström spacetime to generate the metric, Maxwell, Ricci and Weyl tensors for the Kerr-Newman spacetime. This procedure also provides a mechanism whereby the Carter Killing tensor arises from the geodesic angular momentum tensor of the underlying Reissner-Nordström metric. The conformal Killing tensor in the Kerr-Newman spacetime is generated in a similar fashion. The extended algorithm is also applied to the Killing vectors of the Reissner-Nordström spacetime with interesting consequences. The Schwarzschild to Kerr transformation is a special case.

  6. Applicability of the Newman-Janis algorithm to black hole solutions of modified gravity theories

    NASA Astrophysics Data System (ADS)

    Hansen, Devin; Yunes, Nicolás

    2013-11-01

    The Newman-Janis algorithm has been widely used to construct rotating black hole solutions from nonrotating counterparts. While this algorithm was developed within general relativity (GR), it has more recently been applied to nonrotating solutions in modified gravity theories. We find that the application of the Newman-Janis algorithm to an arbitrary non-GR spherically symmetric solution introduces pathologies in the resulting axially symmetric metric. This then establishes that, in general, the Newman-Janis algorithm should not be used to construct rotating black hole solutions outside of General Relativity.

  7. Geodesic Structure of Janis-Newman-Winicour Space-time

    NASA Astrophysics Data System (ADS)

    Zhou, Sheng; Zhang, Ruanjing; Chen, Juhua; Wang, Yongjiu

    2015-08-01

    In the present paper we study the geodesic structure of the Janis-Newman-Winicour(JNW) space-time which contains a strong curvature naked singularity. This metric is an extension of the Schwarzschild geometry included a massless scalar field. We find that the strength parameter μ of the scalar field takes affection on the geodesic structure of the JNW space-time. By solving the geodesic equation and analyzing the behavior of effective potential, we investigate all geodesic types of the test particle and the photon in the JNW space-time. At the same time we simulate all the geodesic orbits corresponding to the energy levels of the effective potential in the JNW space-time.

  8. Supergravity, complex parameters and the Janis-Newman algorithm

    NASA Astrophysics Data System (ADS)

    Erbin, Harold; Heurtier, Lucien

    2015-08-01

    The Demiański-Janis-Newman (DJN) algorithm is an original solution generating technique. For a long time it has been limited to producing rotating solutions, restricted to the case of a metric and real scalar fields, despite the fact that Demiański extended it to include more parameters such as a NUT charge. Recently two independent prescriptions have been given for extending the algorithm to gauge fields and thus electrically charged configurations. In this paper we aim to end setting up the algorithm by providing a missing but important piece, which is how the transformation is applied to complex scalar fields. We illustrate our proposal through several examples taken from N = 2 supergravity, including the stationary BPS solutions from Behrndt et al and Sen's axion-dilaton rotating black hole. Moreover we discuss solutions that include pairs of complex parameters, such as the mass and the NUT charge, or the electric and magnetic charges, and we explain how to perform the algorithm in this context (with the example of Kerr-Newman-Taub-NUT and dyonic Kerr-Newman black holes). The final formulation of the DJN algorithm can possibly handle solutions with five of the six Plebański-Demiański parameters along with any type of bosonic fields with spin less than two (exemplified with the stationary Israel-Wilson-Perjes solutions). This provides all the necessary tools for applications to general matter-coupled gravity and to (gauged) supergravity.

  9. Janie Porter Barrett (1865-1948): Exemplary African American Correctional Educator

    ERIC Educational Resources Information Center

    Muth, Bill; Gehring, Thom; Puffer, Margaret; Mayers, Camille; Kamusikiri, Sandra; Pressley, Glenda

    2009-01-01

    One problem with the literature of correctional education (CE) and prison reform is that the contributions of African Americans have been generally neglected. This is the first of three essays that will begin to fill that gap. Janie Porter Barrett was an important Virginia leader in the period before and after the turn of the 20th century. She…

  10. JANIS 4: An Improved Version of the NEA Java-based Nuclear Data Information System

    NASA Astrophysics Data System (ADS)

    Soppera, N.; Bossant, M.; Dupont, E.

    2014-06-01

    JANIS is software developed to facilitate the visualization and manipulation of nuclear data, giving access to evaluated data libraries, and to the EXFOR and CINDA databases. It is stand-alone Java software, downloadable from the web and distributed on DVD. Used offline, the system also makes use of an internet connection to access the NEA Data Bank database. It is now also offered as a full web application, only requiring a browser. The features added in the latest version of the software and this new web interface are described.

  11. JANIS 4: An Improved Version of the NEA Java-based Nuclear Data Information System

    SciTech Connect

    Soppera, N. Bossant, M.; Dupont, E.

    2014-06-15

    JANIS is software developed to facilitate the visualization and manipulation of nuclear data, giving access to evaluated data libraries, and to the EXFOR and CINDA databases. It is stand-alone Java software, downloadable from the web and distributed on DVD. Used offline, the system also makes use of an internet connection to access the NEA Data Bank database. It is now also offered as a full web application, only requiring a browser. The features added in the latest version of the software and this new web interface are described.

  12. Recasting Janis's Groupthink Model: The Key Role of Collective Efficacy in Decision Fiascoes.

    PubMed

    Whyte

    1998-02-01

    This paper advances an explanation for decision fiascoes that reflects recent theoretical trends and was developed in response to a growing body of research that has failed to substantiate the groupthink model (Janis, 1982). In this new framework, the lack of vigilance and preference for risk that characterizes groups contaminated by groupthink are attributed in large part to perceptions of collective efficacy that unduly exceed capability. High collective efficacy may also contribute to the negative framing of decisions and to certain administrative and structural organizational faults. In the making of critical decisions, these factors induce a preference for risk and a powerful concurrence seeking tendency that, facilitated by group polarization, crystallize around a decision option that is likely to fail. Implications for research and some evidence in support of this approach to the groupthink phenomenon are also discussed. Copyright 1998 Academic Press. PMID:9705802

  13. Why Janie Can't--or Won't--Do Math

    ERIC Educational Resources Information Center

    Tobias, Sheila

    1978-01-01

    From elementary school through college women have failed to keep up with men in the study of mathematics. Examines the differences in social experience for men and women in learning mathematics, some reasons for these differences, and what a number of colleges are doing to offset the problem of anxiety suffered by women who attempt to study…

  14. Revision of Aspergillus section Flavipedes: seven new species and proposal of section Jani sect. nov.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Aspergillus section Flavipedes contains species that are distributed world-wide in soil and rhizosphere, indoor and cave environments, plant endophytes, food contaminants, and occasionally causing human infections. They are producers of many bioactive and extensively studied secondary metabolites an...

  15. Janie Porter Barrett and the Virginia Industrial School for Colored Girls: Community Response to the Needs of African American Children.

    ERIC Educational Resources Information Center

    Peebles-Wilkins, Wilma

    1995-01-01

    Discusses how during the late 19th and early 20th centuries, a social ethos evolved among African American women that led to internal child welfare reform in legally segregated African American communities. Uses as an example the Virginia Industrial School for Colored Girls, founded in 1915, to describe these child welfare developments. (TM)

  16. May Johnny or Janie play the clarinet? The Eastman Study: a report on the orthodontic evaluations of college-level and professional musicians who play brass and woodwind instruments.

    PubMed

    Gualtieri, P A

    1979-09-01

    It is apparent from the findings in this study that although there are some significant differences in the incidence of certain pertinent oral and facial entities between some wind-instrument musicians and their counterpart controls, among mature persons, there is no reason to categorically prohibit all persons with potential malocclusions from studying music. On the other hand, it could be folly to permit any or all instrument pursuits without an extensive, complete, thorough orthodontic analysis. Each case must be counseled on its own merits. In addition, each orthodontically treated patient must be observed closely in the posttreatment retention phase, which should probably be much longer than usual, with particular attention devoted to prevention of lingual collapse or retroclination of the mandibular anterior teeth. PMID:290272

  17. Storage of cord blood attracts private-sector interest

    PubMed Central

    Hass, J

    1999-01-01

    Storage of cord blood from their babies can cost parents several hundred dollars, and some private companies are already offering the service. Janis Hass reports that some Canadian specialists question the value of the banks. PMID:10081471

  18. Caffeine Intake -- Even Dad's -- Linked to Miscarriage, Study Says

    MedlinePlus

    ... new in this study is that men's caffeine consumption also appears to play a role, said Janis ... time to get your body ready -- reduce your consumption of caffeine, get to a healthy weight, don' ...

  19. Parents of Kids with Infectious Diseases

    MedlinePlus

    ... helpful articles antibiotics colds fevers injection tips sports travel in health travel tips janis morrow scholarship links & resources listservs ... disease workshop links & resources personal items standard precautions travel in health immunizations about immunizations current news Flu's Gonna Lose ...

  20. Estimation of the incidence of MRSA patients: evaluation of a surveillance system using health insurance claim data.

    PubMed

    Tanihara, S; Suzuki, S

    2016-08-01

    Because sentinel surveillance systems cannot obtain information about patients who visit non-sentinel medical facilities, the characteristics of patients identified by these systems may be biased. In this study, we evaluated the representativeness of a methicillin-resistant Staphylococcus aureus (MRSA) surveillance system using health insurance claim (HIC) data, which does not depend on physician notification. We calculated the age-specific incidence of MRSA patients using data from the Japan Nosocomial Infections Surveillance (JANIS) programme, which is based on sentinel surveillance systems, and inpatient HICs submitted to employee health insurance organizations in 2011, and then computed age-specific incidence ratios between the HIC and JANIS data. Age-specific MRSA incidence in both datasets followed J-shaped curves with similar shapes. For all age groups, the ratios between HIC and JANIS data were around 10. These findings indicate that JANIS notification of MRSA cases was not affected by patients' age. PMID:27350233

  1. Asthma: NIH-Sponsored Research and Clinical Trials | NIH MedlinePlus the Magazine

    MedlinePlus

    ... the National Institute of Environmental Health Sciences (NIEHS). “Early life exposure to mold seems to play a critical role in childhood asthma development,” says Tiina Reponen, Ph.D., lead study author ...

  2. Synemon ignita sp. nov., a new sun moth species from southern Australia (Lepidoptera, Castniidae).

    PubMed

    Kallies, Axel; Edwards, Ted; Young, Andy; Douglas, Fabian

    2016-01-01

    Sun moths (Castniidae) constitute a family of day-flying moths that due to their slim bodies, broad and often richly coloured wings and clubbed antennae closely resemble butterflies. However, despite this superficial similarity, sun moths are not related to butterflies but belong to the diverse cossoid assemblage of lepidopterous families (Edwards et al. 1998). Until recently, Castniidae were assigned to the superfamily Sesioidea (Minet 1991). A molecular study by Mutanen et al. (2010), however, failed to find support for a close relationship of Sesiidae and Castniidae, resulting in the inclusion of both families in a larger concept of Cossoidea (Nieukerken et al. 2011). In contrast, Heikkil et al. (2015) who added considerable morphological data to DNA, recovered Sesioidea as monophyletic, with Sesiidae, Castniidae and Brachodidae as constituent families, yet with low support values. Thus, although the monophyly of Castniidae is well supported, the systematic position of this family is unresolved. PMID:27394467

  3. Towards a History of Adult Literacy in Australia. A Record of the History of Adult Literacy Weekend (Armidale, New South Wales, Australia, November 12-13, 1994). Second Edition, Revised.

    ERIC Educational Resources Information Center

    Technology Univ., Sydney (Australia).

    This document contains materials about and from the "History of Adult Literacy Weekend" that was held at the University of New England in Armidale, Australia. The following papers about the weekend are included: "Foreword" (Patricia Ward, Rosie Wickert); "Introduction" (Rosie Wickert); "Focus on Oral History" (Janis Wilton); and "Arch Nelson…

  4. Effects of Organic and Inorganic Fertilizers on Marigold Growth and Flowering

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Two experiments were conducted to evaluate the growth and flowering responses of greenhouse-grown French marigold (Tagetes patula L. ‘Janie Deep Orange’) to two non-composted broiler chicken litter-based organic fertilizers 4-2-2 and 3-3-3, and one commonly used synthetic controlled-release fertiliz...

  5. The Midcareer Crisis: A Description of the Psychological Dynamics of Transition and Adaptation.

    ERIC Educational Resources Information Center

    Perosa, Sandra L.; Perosa, Linda M.

    1983-01-01

    Compared three groups of people (N=134) facing midcareer crisis using a structured interview. Suggested that Hopson and Adams' (1977) model can provide a framework for understanding emotional factors in voluntary career transitions. Janis and Mann's (1977) conflict model describes where in the decision-making process the groups chose alternative…

  6. 15. 'Southern Pacific R.R., One 236'0' Bet. End Pins S. ...

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

    15. 'Southern Pacific R.R., One 236'-0' Bet. End Pins S. Tr. Thro'. Draw Bridge over Sacramento River at Tehama, The Phoenix Bridge Co., Phoenixville, Pa., Jan'y 19th 98, Dwg. 585.' - Southern Pacific Railroad Shasta Route, Bridge No. 210.52, Milepost 210.52, Tehama, Tehama County, CA

  7. 75 FR 75695 - Certain Footwear: Recommendations for Modifying the Harmonized Tariff Schedule of the United States

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-12-06

    ... INFORMATION CONTACT: David Beck, Director, Office of Tariff Affairs and Trade Agreements (202-205-2603, fax 202-205-2616, david.beck@usitc.gov ), or Janis L. Summers, Attorney Advisor, Office of Tariff Affairs... promote the uniform application of the Harmonized System Convention. Subsections (b)-(d) of section...

  8. High School Gifted.

    ERIC Educational Resources Information Center

    Drum, Jean, Ed.

    1993-01-01

    This theme issue on gifted high school students presents several feature articles, a California legislative update, and an editorial. In "Summer Seminar '93--California in the 21st Century," Janis Van Dreal describes a 2-week residential program in which gifted high school students examined California's future. "Visiting a Gifted Program in…

  9. ACUTE AND CHRONIC TOXICITY OF BREVETOXIN TO OYSTERS AND GRASS SHRIMP

    EPA Science Inventory

    Walker, Calvin C., James T. Winstead, Steven S. Foss, Janis C. Kurtz, James Watts, Jeanne E. Scott and William S. Fisher. In press. Acute and Chronic Toxicity of Brevetoxin to Oysters and Grass Shrimp (Abstract). To be presented at the SETAC Fourth World Congress, 14-18 November ...

  10. Are We Facing an Epidemic of Self-Injury?

    ERIC Educational Resources Information Center

    Brumberg, Joan Jacobs

    2006-01-01

    This article discusses two Cornell research studies on the prevalence of self-injury or "cutting" in today's youth, led by Janis Whitlock, and presents historical perspectives on the issue. The first study randomly surveyed 3,069 undergraduate and graduate students at Cornell University and Princeton University. Data showed that 17 percent of the…

  11. Performance of BNL-TSTA compound cryopump

    SciTech Connect

    Hseuh, H C; Worwetz, H A

    1980-01-01

    A compound cryopump using cryocondensation pumping for hydrogen isotopes and cryosorption pumping with coconut charcoal as adsorbent for helium was designed. This compound cryopump was subsequently built (by Janis Research, Stoneham, MA) and has been tested at Brookhaven, fulfilling the design requirements and are delivered to Tritium Systems Test Assembly (TSTA) Vacuum Facility at Los Alamos Scientific Laboratory (LASL) for on-line operations.

  12. Decisionmaking Context Model for Enhancing Evaluation Utilization.

    ERIC Educational Resources Information Center

    Brown, Robert D.; And Others

    1984-01-01

    This paper discusses two models that hold promise for helping evaluators understand and cope with different decision contexts: (1) the conflict Model (Janis and Mann, 1977) and the Social Process Model (Vroom and Yago, 1974). Implications and guidelines for using decisionmaking models in evaluation settings are presented. (BS)

  13. Black Image: Education Copes With Color. Essays on the Black Experience.

    ERIC Educational Resources Information Center

    Grambs, Jean Dresden, Ed.; And Others

    The contents of this book, about the impact on the values of young people which textbooks and other books designed for them from preschool through twelfth grade have by the way they depict black people in the United States, include the following articles: (1) "Storytellers and gatekeepers," J. Janis and P. Franklin; (2) "Black vs. Negro history:…

  14. Defining Strong State Accountability Systems: How Can Better Standards Gain Greater Traction? A First Look

    ERIC Educational Resources Information Center

    Reed, Eileen; Scull, Janie; Slicker, Gerilyn; Winkler, Amber M.

    2012-01-01

    Rigorous standards and aligned assessments are vital tools for boosting education outcomes but they have little traction without strong accountability systems that attach consequences to performance. In this pilot study, Eileen Reed, Janie Scull, Gerilyn Slicker, and Amber Winkler lay out the essential features of such accountability systems,…

  15. Proceedings of the Annual Meeting of the Association for Education in Journalism and Mass Communication (86th, Kansas City, Missouri, July 30-August 2, 2003). Miscellaneous Divisions.

    ERIC Educational Resources Information Center

    2003

    The Miscellaneous Divisions of the proceedings contains the following 17 papers: "Analyzing Sequential Art: Visual Narrative Techniques in 'Calvin and Hobbes'" (Sharron M. Hope); "A Critical Vision of Gender in 2002 Campaign Ads" (Janis Teruggi Page); "Personal Impact Assessment of Advertising Culture of 'Whiteness': Facial Skin Color Preferences…

  16. 76 FR 41450 - Notice of Request for Extension of a Currently Approved Information Collection

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-07-14

    ... of the Sugar Import Licensing Program is to permit entry of raw cane sugar, unrestricted by the... for Sugar Import Licensing Programs described in 7 CFR part 1530. DATES: Comments should be received... (202) 720-2194, or by e-mail at: William.Janis@fas.usda.gov . SUPPLEMENTARY INFORMATION: Title:...

  17. Teaching Medical Student Psychiatry Through Contemporary Music

    ERIC Educational Resources Information Center

    Egan, William H.

    1977-01-01

    An audio technique uses contemporary music recordings to illustrate various personality disorders, including: schizoid, paranoid, compulsive, antisocial, and hysterical. The works of Bob Dylan, Paul Simon, Harry Chapin, the Beatles, Janis Ian, James Taylor, Tammy Wynette, and others are cited. (LBH)

  18. A Preliminary View of the Quality of Decision-Making in the Benchmark Year of 1984. AIR 1985 Annual Forum Paper.

    ERIC Educational Resources Information Center

    Spiro, Louis M.; Campbell, Jill F.

    Perceptions of college institutional research directors concerning the quality of executive decision making at their institutions were studied. Perceptions were assessed using a theoretical model of Groupthink developed by Janis, who postulates that a high amount of environmental stress should lead to a greater degree of "sticking-together" by the…

  19. Groupthink: Hypothesis in Need of Testing.

    ERIC Educational Resources Information Center

    Moorhead, Gregory

    1982-01-01

    Reviews the major tenets of the groupthink hypothesis of Irving Janis, as well as the research on which it is based. Reviews previous research on group dynamics related to groupthink. Proposes guidelines for research to test the propositions of groupthink. (Author/RC)

  20. Groupthink: Effects of Cohesiveness and Problem-Solving Procedures on Group Decision Making.

    ERIC Educational Resources Information Center

    Callaway, Michael R.; Esser, James K.

    1984-01-01

    Tested Janis' groupthink formulation with 126 students by manipulating group cohesiveness and adequacy of decision procedures in a factorial design. Results showed highest quality decisions were produced by groups of intermediate cohesiveness. Highly cohesive groups without adequate decision procedures (the groupthink condition) tended to make the…

  1. Small Group Dynamics and the Watergate Coverup: A Case Study of Groupthink.

    ERIC Educational Resources Information Center

    Cline, Rebecca J.

    The decisions President Richard Nixon and his closest advisors made in the Watergate coverup were products of what Irving Janis calls "groupthink." Groupthink, a type of decision-making emphasizing unanimity over objective evaluation, develops when the decision makers (1) form a group of marked cohesiveness, (2) insulate themselves from outside…

  2. "Feminism Lite?" Feminist Identification, Speaker Appearance, and Perceptions of Feminist and Antifeminist Messengers

    ERIC Educational Resources Information Center

    Bullock, Heather E.; Fernald, Julian L.

    2003-01-01

    Drawing on a communications model of persuasion (Hovland, Janis, & Kelley, 1953), this study examined the effect of target appearance on feminists' and nonfeminists' perceptions of a speaker delivering a feminist or an antifeminist message. One hundred three college women watched one of four videotaped speeches that varied by content (profeminist…

  3. Effective Teaching in the Multi-Cultural Classroom.

    ERIC Educational Resources Information Center

    Gotch, Donna; Brydges, Michael

    Community college instructors and administrators need to understand teacher immediacy research and the role of immediacy in the multi-cultural classroom. Immediacy can be viewed as a combination of nonverbal behaviors used to accentuate a verbal message and reduce physical and psychological distance between interactants. Janis Andersen's research…

  4. Structural properties and UV to NIR absorption spectra of metal-free phthalocyanine (H2Pc) thin films P. B. Thakor, P. N. Gajjar and A. R. Jani: Different reference systems in the study of structural properties of some simple liquid metals Shazia Bashir, M. S. Rafique, M. Khaleeq-ur-Rahman, Faizan-ul-Haq and B. R. Alvina: CO2 and Nd:YAG laser radiation induced damage in aluminium Smail Bougouffa: The study of atomic transitions by use of Numerov technique in schematic model

    NASA Astrophysics Data System (ADS)

    El-Nahass, M. M.; Farid, A. M.; Attia, A. A.; Ali, H. A. M.

    The structural properties and absorption spectra of H2Pc thin films have been studied. The films used in these studies were thermally evaporated on glass/quartz substrates with thickness ranging from 60 to 460 nm. The XRD studies of H2Pc thin films showed that the as-deposited films have a-form with monoclinic system. The mean crystallite size (L), the dislocation density (d) and the strain (x) were evaluated. The molecular structure of H2Pc thin films is confirmed by analysis of (FTIR) spectra. The surface morphology of H2Pc thin films was examined by scanning electron microscope. The absorption spectra of H2Pc recorded in the UV - VIS - IR region for the as-deposited and the annealed thin films of different thickness have been analyzed. The spectra showed two absorption bands namely the Q-band and the Soret (B)-band. The Q-band shows its characteristic splitting (Davydove splitting) with DQ = 0.21 eV. Values of some important optical parameters, namely optical absorption coefficient (a¢), molar extinction coefficient (emolar), half-band-width (Dl), electronic dipole strength (q2) and oscillator strength (f) were calculated. The fundamental and the onset of the indirect energy gaps were also determined as 2.47 and 1.4 eV, respectively.

  5. Charged rotating noncommutative black holes

    NASA Astrophysics Data System (ADS)

    Modesto, Leonardo; Nicolini, Piero

    2010-11-01

    In this paper we complete the program of the noncomutative geometry inspired black holes, providing the richest possible solution, endowed with mass, charge and angular momentum. After providing a prescription for employing the Newman-Janis algorithm in the case of nonvanishing stress tensors, we find regular axisymmetric charged black holes in the presence of a minimal length. We study also the new thermodynamics and we determine the corresponding higher-dimensional solutions. As a conclusion we make some consideration about possible applications.

  6. Charged rotating noncommutative black holes

    SciTech Connect

    Modesto, Leonardo; Nicolini, Piero

    2010-11-15

    In this paper we complete the program of the noncomutative geometry inspired black holes, providing the richest possible solution, endowed with mass, charge and angular momentum. After providing a prescription for employing the Newman-Janis algorithm in the case of nonvanishing stress tensors, we find regular axisymmetric charged black holes in the presence of a minimal length. We study also the new thermodynamics and we determine the corresponding higher-dimensional solutions. As a conclusion we make some consideration about possible applications.

  7. Uniqueness of the static spacetimes with a photon sphere in Einstein-scalar field theory

    NASA Astrophysics Data System (ADS)

    Yazadjiev, Stoytcho

    2015-06-01

    In the present paper we prove a uniqueness theorem for the static and asymptotically flat solutions to the Einstein-scalar field equations which possess a photon sphere. We show that such solutions are uniquely specified by their mass M and scalar charge q and that they are isometric to the Janis-Newman-Winicour solution with the same mass and scalar charge subject to the inequality q/2M2<3 .

  8. Group Dynamics in Top Management Teams: Groupthink, Vigilance, and Alternative Models of Organizational Failure and Success.

    PubMed

    Peterson; Owens; Tetlock; Fan; Martorana

    1998-02-01

    This study explored the heuristic value of Janis' (1982) groupthink and vigilant decision making models as explanations of failure and success in top management team decision making using the Organizational Group Dynamics Q-sort (GDQ). Top management teams of seven Fortune 500 companies were examined at two historical junctures-one when the team was successful (defined as satisfying strategic constituencies) and one when the team was unsuccessful. Results strongly supported the notion that a group' decision making process is systematically related to the outcomes experienced by the team. Ideal-type Q-sorts organized around Janis' analysis of groupthink and vigilance were substantially correlated with Q-sorts of failing and successful groups, respectively. The fit was, however, far from perfect. Ideal-type Q-sorts derived from other frameworks correlated better with the failure-success classification than did the Janis-derived ideal types. Successful groups showed some indicators of groupthink (e.g., risk-taking, cohesion, and strong, opinionated leaders), whereas unsuccessful groups showed signs of vigilance (e.g., internal debate to the point of factionalism). The results illustrate the usefulness of the GDQ for developing and empirically testing theory in organizational behavior from historical cases. Copyright 1998 Academic Press. PMID:9705805

  9. Newman-Penrose constants of the Kerr-Newman metric

    SciTech Connect

    Gong Xuefei; Shang Yu; Bai Shan; Cao Zhoujian; Lau, Y. K.; Luo Ziren

    2007-11-15

    The Newman-Unti formalism of the Kerr-Newman metric near future null infinity is developed, with which the Newman-Penrose constants for both the gravitational and electromagnetic fields of the Kerr-Newman metric are computed and shown to be zero. The multipole structure near future null infinity in the sense of Janis-Newman of the Kerr-Newman metric is then further studied. It is found that up to the 2{sup 4}-pole, modulo a constant dependent upon the order of the pole, these multipole moments agree with those of Geroch-Hansen multipole moments defined at spatial infinity.

  10. Time delay and magnification centroid due to gravitational lensing by black holes and naked singularities

    SciTech Connect

    Virbhadra, K. S.; Keeton, C. R.

    2008-06-15

    We model the massive dark object at the center of the Galaxy as a Schwarzschild black hole as well as Janis-Newman-Winicour naked singularities, characterized by the mass and scalar charge parameters, and study gravitational lensing (particularly time delay, magnification centroid, and total magnification) by them. We find that the lensing features are qualitatively similar (though quantitatively different) for Schwarzschild black holes, weakly naked, and marginally strongly naked singularities. However, the lensing characteristics of strongly naked singularities are qualitatively very different from those due to Schwarzschild black holes. The images produced by Schwarzschild black hole lenses and weakly naked and marginally strongly naked singularity lenses always have positive time delays. On the other hand, strongly naked singularity lenses can give rise to images with positive, zero, or negative time delays. In particular, for a large angular source position the direct image (the outermost image on the same side as the source) due to strongly naked singularity lensing always has a negative time delay. We also found that the scalar field decreases the time delay and increases the total magnification of images; this result could have important implications for cosmology. As the Janis-Newman-Winicour metric also describes the exterior gravitational field of a scalar star, naked singularities as well as scalar star lenses, if these exist in nature, will serve as more efficient cosmic telescopes than regular gravitational lenses.

  11. "Bipolar groupthink": assessing groupthink tendencies in authentic work groups.

    PubMed

    Rosander, M; Stiwne, D; Granström, K

    1998-06-01

    Research on regressive group processes such as Janis' (1982) "groupthink" phenomenon has rarely focused on work groups in authentic settings. In this study, teams from six different organisations (n = 308) were studied by using a groupthink questionnaire constructed in accordance with the symptoms of groupthink described by Janis. It was hypothesised that groupthink could be described as a bipolar construct identifying either an omnipotent or a depressive variant of a group's delusions about its own and other groups' features. The questionnaire showed reasonably good reliability as a whole and a factor analysis identified three factors in line with the proposed theoretical model in which the two different types of groupthink can be distinguished. We propose that any group might have a tendency or predisposition to react in either of the two directions during provocative circumstances. The six different organisations exhibited different types of groupthink to a varying degree. A religious sect was the one most characterised by omnipotent groupthink, while a technological company and a psychiatric team seemed to be the ones with most features of depressive groupthink. PMID:9676161

  12. Groupthink, Bay of Pigs, and Watergate Reconsidered.

    PubMed

    Raven

    1998-02-01

    Irving Janis's concept of groupthink can be seen in the context of our on-again-off-again love affair with groups. Group decisions have often been seen as offering the benefits of collective wisdom, but may also lead to disastrous consequences. Groupthink then focuses on the negative effects of erroneous group decisions. Two major examples of groupthink are reexamined and compared: the disastrous Bay of Pigs decision by the elite advisory group of President Kennedy, and the advisory groups of President Nixon, which led to the Watergate disaster and at unsuccessful attempts to cover up. In both, it is suggested there was a "runaway norm," escalation and polarization with the norm being to exceed other members of the group in taking more extreme and unrestrained actions against an "enemy." While Janis seems to suggest that groupthink will ultimately lead the group to fail in its ultimate endeavors, we need to consider the frightening possibility that in the case of the Nixon group, the group actions came close to being successful. Copyright 1998 Academic Press. PMID:9705808

  13. Light on curved backgrounds

    NASA Astrophysics Data System (ADS)

    Batic, D.; Nelson, S.; Nowakowski, M.

    2015-05-01

    We consider the motion of light on different spacetime manifolds by calculating the deflection angle, lensing properties and by probing into the possibility of bound states. The metrics in which we examine the light motion include, among other items, a general relativistic dark matter metric, a dirty black hole, and a worm hole metric, the last two inspired by noncommutative geometry. The lensing in a holographic screen metric is discussed in detail. We study also the bending of light around naked singularities like, e.g., the Janis-Newman-Winicour metric and include other cases. A generic property of light behavior in these exotic metrics is pointed out. For the standard metric like the Schwarzschild and Schwarzschild-de Sitter cases, we improve the accuracy of the lensing results for the weak and strong regimes.

  14. Cosmic Perspectives

    NASA Astrophysics Data System (ADS)

    Biswas, S. K.; Mallik, D. C. V.; Vishveshwara, C. V.

    2008-07-01

    1. Astronomy in ancient and medieval China Joseph Needham; 2. Indian astronomy: an historical perspective B. V. Subbarayappa; 3. Making of astronomy in ancient India Debiprasad Chattopadhyaya; 4. The impact of astronomy on the development of western science Jean-Claude Pecker; 5. Man and the Universe Hubert Reeves; 6. Understanding the Universe - challenges and directions in modern observational astronomy Harlan Smith, Jr: 7. Frontiers in cosmology Fred Hoyle; 8. Did the Universe originate in a big bang? Jayant Narlikar; 9. The dark matter problem Bernard Carr; 10. Geometry and the Universe C. V. Vishveshwara; 11. The origin and evolution of life Cyril Ponnamperuma; 12. The anthropic principle: self selection as an adjunct to natural selection Brandon Carter; 13. Astrology and science: an examination of the evidence Ivan Kelly, Roger Culver and Peter Loptson; 14. Astronomy and science fiction Allen Janis.

  15. Penrose process in a charged axion-dilaton coupled black hole

    NASA Astrophysics Data System (ADS)

    Ganguly, Chandrima; SenGupta, Soumitra

    2016-04-01

    Using the Newman-Janis method to construct the axion-dilaton coupled charged rotating black holes, we show that the energy extraction from such black holes via the Penrose process takes place from the axion/Kalb-Ramond field energy responsible for rendering the angular momentum to the black hole. Determining the explicit form for the Kalb-Ramond field strength, which is argued to be equivalent to spacetime torsion, we demonstrate that at the end of the energy extraction process, the spacetime becomes torsion free with a spherically symmetric non-rotating black hole remnant. In this context, applications to physical phenomena, such as the emission of neutral particles in astrophysical jets, are also discussed. It is seen that the infalling matter gains energy from the rotation of the black hole, or equivalently from the axion field, and that it is ejected as a highly collimated astrophysical jet.

  16. Rotating black hole and quintessence

    NASA Astrophysics Data System (ADS)

    Ghosh, Sushant G.

    2016-04-01

    We discuss spherically symmetric exact solutions of the Einstein equations for quintessential matter surrounding a black hole, which has an additional parameter (ω ) due to the quintessential matter, apart from the mass ( M). In turn, we employ the Newman-Janis complex transformation to this spherical quintessence black hole solution and present a rotating counterpart that is identified, for α =-e^2 ne 0 and ω =1/3, exactly as the Kerr-Newman black hole, and as the Kerr black hole when α =0. Interestingly, for a given value of parameter ω , there exists a critical rotation parameter (a=aE), which corresponds to an extremal black hole with degenerate horizons, while for aaE. We find that the extremal value a_E is also influenced by the parameter ω and so is the ergoregion.

  17. Ultrarelativistic boost with scalar field

    NASA Astrophysics Data System (ADS)

    Svítek, O.; Tahamtan, T.

    2016-02-01

    We present the ultrarelativistic boost of the general global monopole solution which is parametrized by mass and deficit solid angle. The problem is addressed from two different perspectives. In the first one the primary object for performing the boost is the metric tensor while in the second one the energy momentum tensor is used. Since the solution is sourced by a triplet of scalar fields that effectively vanish in the boosting limit we investigate the behavior of a scalar field in a simpler setup. Namely, we perform the boosting study of the spherically symmetric solution with a free scalar field given by Janis, Newman and Winicour. The scalar field is again vanishing in the limit pointing to a broader pattern of scalar field behaviour during an ultrarelativistic boost in highly symmetric situations.

  18. Sex differences in self-concept in Spanish secondary school students.

    PubMed

    Sotelo, M J

    2000-12-01

    The aims of the study were to examine differences between boys and girls in global self-esteem and in specific domains of self-concept. Several measures of global self-esteem and multidimensional self-concept were administered to 61 boys and 64 girls. Analysis showed that boys reported higher scores than girls on global self-esteem, measured on the Coopersmith Self-esteem Inventory and the Feelings of Inadequacy Scale by Janis-Field, but this result was not reproduced when self-esteem was measured on the Rosenberg Self-esteem Scale. No differences have been found in domain-specific self-concepts, except for the ethical-moral self-concept, on which girls reported higher scores than boys. PMID:11191376

  19. Preventing Groupthink Revisited: Evaluating and Reforming Groups in Government.

    PubMed

    Hart

    1998-02-01

    This article critically examines Janis's recommendations for preventing groupthink in high-level policymaking. It puts forward three models of small group functioning in government, each of which highlights different dimensions of collegial policymaking and distinct criteria for evaluating group performance. Each model also inspires different proposals for groupthink prevention and improvement of group performance in general. Proposals for designing and managing high-level groups in government need to take into account these multiple perspectives. Furthermore, their proponents should be aware of the institutionalized and competitive context in which political decision groups operate. Evaluations of their performance and proposals for reforming them are inevitably tied up in this process. This has important implications for the feasibility of recommendations set forth by small group analysts. The article concludes with an agenda for increasing the policy relevance and practical feasibility of research on political decision groups. Copyright 1998 Academic Press. PMID:9705806

  20. Effects of dominance on group decision making: toward a stress-reduction explanation of groupthink.

    PubMed

    Callaway, M R; Marriott, R G; Esser, J K

    1985-10-01

    Janis (1972) proposed that groupthink is essentially a stress-reduction process. Cohesive groups reduce the stress of decision making by suppressing critical inquiry. Theoretically, groupthink could be prevented in cohesive groups if the stress could be diffused by other factors. We investigated the effects of task structure (decision-making procedures) and an individual factor (dominance) on the quality of group decision making, anxiety, and symptoms of groupthink. Students (n = 112) participated in twenty-eight 4-person, mixed-sex groups. Groups composed of highly dominant members made higher quality decisions, exhibited lower state anxiety, and took more time to reach a decision. They also tended to make more statements of disagreement and agreement, and to report more group influence on the members. Decision-making procedures had little effect on the decision process. PMID:4057051

  1. Magnetism, Superconductivity and Pseudogap at the LaAlO3-SrTiO3 Interface

    NASA Astrophysics Data System (ADS)

    Mannhart, Jochen

    2014-03-01

    The electron liquid at the LaAlO3-SrTiO3 interface is a two-dimensional superconductor and simultaneously displays magnetic order. To experimentally explore the fundamental properties of this state, we developed a planar tunnel junction technology that allows to measure the spectral density-of-states of the superconducting liquid while its carrier density can be altered by the electric-field effect. These studies yield surprising results, as key features of the superconducting electron liquid at the LaAlO3-SrTiO3 interface are found to be analogous to features deemed characteristic for the high-Tc cuprates. This work was performed in collaboration with C. Richter, H. Boschker, W. Dietsche, E. Fillis-Tsirakis, R. Jany, F. Loder, L.F. Kourkoutis, D.A. Muller, J.R. Kirtley, and C.W. Schneider.

  2. Cosmic Perspectives

    NASA Astrophysics Data System (ADS)

    Biswas, S. K.; Mallik, D. C. V.; Vishveshwara, C. V.

    1989-09-01

    1. Astronomy in ancient and medieval China Joseph Needham; 2. Indian astronomy: an historical perspective B. V. Subbarayappa; 3. Making of astronomy in ancient India Debiprasad Chattopadhyaya; 4. The impact of astronomy on the development of western science Jean-Claude Pecker; 5. Man and the Universe Hubert Reeves; 6. Understanding the Universe - challenges and directions in modern observational astronomy Harlan Smith, Jr: 7. Frontiers in cosmology Fred Hoyle; 8. Did the Universe originate in a big bang? Jayant Narlikar; 9. The dark matter problem Bernard Carr; 10. Geometry and the Universe C. V. Vishveshwara; 11. The origin and evolution of life Cyril Ponnamperuma; 12. The anthropic principle: self selection as an adjunct to natural selection Brandon Carter; 13. Astrology and science: an examination of the evidence Ivan Kelly, Roger Culver and Peter Loptson; 14. Astronomy and science fiction Allen Janis.

  3. Reproductive Biology and Its Impact on Body Size: Comparative Analysis of Mammalian, Avian and Dinosaurian Reproduction

    PubMed Central

    Werner, Jan; Griebeler, Eva Maria

    2011-01-01

    Janis and Carrano (1992) suggested that large dinosaurs might have faced a lower risk of extinction under ecological changes than similar-sized mammals because large dinosaurs had a higher potential reproductive output than similar-sized mammals (JC hypothesis). First, we tested the assumption underlying the JC hypothesis. We therefore analysed the potential reproductive output (reflected in clutch/litter size and annual offspring number) of extant terrestrial mammals and birds (as “dinosaur analogs”) and of extinct dinosaurs. With the exception of rodents, the differences in the reproductive output of similar-sized birds and mammals proposed by Janis and Carrano (1992) existed even at the level of single orders. Fossil dinosaur clutches were larger than litters of similar-sized mammals, and dinosaur clutch sizes were comparable to those of similar-sized birds. Because the extinction risk of extant species often correlates with a low reproductive output, the latter difference suggests a lower risk of population extinction in dinosaurs than in mammals. Second, we present a very simple, mathematical model that demonstrates the advantage of a high reproductive output underlying the JC hypothesis. It predicts that a species with a high reproductive output that usually faces very high juvenile mortalities will benefit more strongly in terms of population size from reduced juvenile mortalities (e.g., resulting from a stochastic reduction in population size) than a species with a low reproductive output that usually comprises low juvenile mortalities. Based on our results, we suggest that reproductive strategy could have contributed to the evolution of the exceptional gigantism seen in dinosaurs that does not exist in extant terrestrial mammals. Large dinosaurs, e.g., the sauropods, may have easily sustained populations of very large-bodied species over evolutionary time. PMID:22194835

  4. [Subjective verbal methods in preoperative measurement of anxiety].

    PubMed

    Höfling, S; Hutner, G; Ott, H; Fichte, K; Doenicke, A

    1988-06-01

    The role of preoperative anxiety in perioperative adaptation is viewed in two different ways. Janis suggested that anxiety is a drive that evokes the cognitive work of worrying. Leventhal stresses the importance of coping behavior for adaptation, while anxiety may or may not accompany this coping process. Both theories have empirical support. The aim of this study was to determine whether both theories could show empirical support because the scientists chose different methods: Janis used interviews, Leventhal and Lazarus anxiety scales. The study analyzed the pre- and postoperative emotional reactions of surgical patients with three different methods of anxiety measurement: an anxiety scale, a fear thermometer, and a psychoanalytic interview (Gottschalk-Gleser content analysis method). The different methods were compared and related to the adaptation behavior (Table 3). The data showed a clear interaction between the selected methods and respective theories about the effects of preoperative anxiety on intra- and postoperative adaptation. The anxiety scales showed no correlation with adaptation behavior (blood pressure and heart rate during surgery; postoperative pain medication) and were not related to the anxiety scores obtained from the interview (content analysis). On the other hand, the interview anxiety measurements showed a clear relationship between separation anxiety (and also shame anxiety), physiological excitement during surgery (increase in heart rate), and postoperative medication (increased analgesics and tranquilizers). The patients who worried about the risks of surgery (Verletzungsangst, see Fig. 3) had very good perioperative adjustment, so that the quality of anxiety measured in the interview was very important for the prediction of adaptation. PMID:3407901

  5. Revisiting the Bay of Pigs and Vietnam Decisions 25 Years Later: How Well Has the Groupthink Hypothesis Stood the Test of Time?

    PubMed

    Kramer

    1998-02-01

    Even after a quarter of a century, the groupthink hypothesis remains an influential framework for understanding the origins of group decision making fiascoes. Much of the original empirical evidence for this hypothesis was derived from a series of incisive qualitative studies of major policy fiascoes, including the ill-fated Bay of Pigs invasion and U.S. military escalation of the Vietnam War. In the 25 years since the groupthink hypothesis was first formulated, new evidence, including recently declassified documents, rich oral histories, and informative memoirs by key participants in these decisions have become available to scholars, casting new light on the decision making process behind both the Bay of Pigs and Vietnam. Much of this new evidence does not support Janis's original characterization of these processes. In particular, it suggests that dysfunctional group dynamics stemming from group members' strivings to maintain group cohesiveness were not as prominent a causal factor in the deliberation process as Janis argued. Instead, the evidence suggests that the decision making process was heavily influenced by how Presidents Kennedy and Johnson construed their options. Both Kennedy and Johnson tended to evaluate their alternatives primarily in terms of their political consequences, especially the desire to avoid what they construed as unacceptable political losses and potential damage to their reputations. Viewed in aggregate, this new evidence suggests that the groupthink hypothesis overstates the influence of small group dynamics, while understating the role political considerations played in these decisions. Thus, although both decisions may have been seriously flawed, the logic of this failure should be attributed to political psychological rather than social psychological processes. Copyright 1998 Academic Press. PMID:9705804

  6. 10Be in last deglacial climate simulated by ECHAM5-HAM - Part 1: Climatological influences on 10Be deposition

    NASA Astrophysics Data System (ADS)

    Heikkilä, U.; Phipps, S. J.; Smith, A. M.

    2013-07-01

    Be produced has to be deposited by mass conservation. This dominates over any climatic influences on 10Be deposition. Snow concentrations, however, do not follow mass conservation and can potentially be impacted more by climate due to precipitation changes. Quantifying the impact of deglacial climate modulation on 10Be in terms of preserving the solar signal locally is analysed in an accompanying paper (Heikkilä et al., 2013).

  7. 10Be in late deglacial climate simulated by ECHAM5-HAM - Part 1: Climatological influences on 10Be deposition

    NASA Astrophysics Data System (ADS)

    Heikkilä, U.; Phipps, S. J.; Smith, A. M.

    2013-11-01

    concentrations can vary significantly. Averaged over a longer period, all 10Be produced has to be deposited by mass conservation. This dominates over any climatic influences on 10Be deposition. Snow concentrations, however, do not follow mass conservation and can potentially be impacted more by climate due to precipitation changes. Quantifying the impact of deglacial climate modulation on 10Be in terms of preserving the solar signal locally is analysed in an accompanying paper (Heikkilä et al., 10Be in late deglacial climate simulated by ECHAM5-HAM - Part 2: Isolating the solar signal from 10Be deposition).

  8. PREFACE: Annual Conference on Functional Materials and Nanotechnologies - FM&NT 2011

    NASA Astrophysics Data System (ADS)

    Sternberg, Andris; Muzikante, Inta; Zicans, Janis

    2011-06-01

    The International Conference Functional Materials and Nanotechnologies (FM&NT-2011) was held in Riga, 5-8 April 2011 in the Institute of Solid State Physics, University of Latvia (ISSP LU). The conference was organized in co-operation with projects ERANET 'MATERA' and National Research programme in Materials Science and Information Technologies. The purpose of the conference was to bring together scientists, engineers and students from universities, research institutes and related industrial companies active in the field of advanced material science and materials technologies trends and future activities. Scientific themes covered in the conference are: theoretical research and modelling of processes and materials; materials for energetics, renewable energy technologies and phtovoltaics; multifunctional inorganic, organic and hybrid materials for photonic, micro and nanoelectronic applications and innovative methods for research of nanostructures; advanced technologies for synthesis and research of nanostructured materials, nanoparticles, thin films and coatings; application of innovative materials in science and economics. The number of registered participants from 17 countries was nearly 300. During three days of the conference 22 invited, 69 oral reports and 163 posters were presented. 40 papers, based on these reports, are included in this volume of IOP Conference Series: Materials Science and Engineering. Additional information about FM&NT-2011 is available in its homepage http://www.fmnt.lu.lv. The Organizing Committee would like to thank all speakers, contributors, session chairs, referees and meeting staff for their efforts in making the FM&NT-2011 successful. The Organizing Committee sincerely hopes that that the conference gave all participants new insights into the widespread development of functional materials and nanotechnologies and would enhance the circulation of information released at the meeting. Andris Sternberg Inta Muzikante Janis Zicans

  9. Integration of atomic layer deposited nanolaminates on silicon waveguides (Conference Presentation)

    NASA Astrophysics Data System (ADS)

    Autere, Anton; Karvonen, Lasse; Säynätjoki, Antti; Roussey, Matthieu; Roenn, John; Färm, Elina; Kemell, Marianna; Tu, Xiaoguang; Liow, Tsung-Yang; Lo, Patrick; Ritala, Mikko; Leskelä, Markku; Lipsanen, Harri; Honkanen, Seppo; Sun, Zhipei

    2016-05-01

    waveguides and show signal enhancement. Our results show that atomic layer deposited nanolaminates can potentially open new possibilities for various photonic applications, such as silicon photonic devices for light emission and amplification, optical sensing and all-optical signal processing. References [1] A. Autere, L. Karvonen, A. Säynätjoki, M. Roussey, E. Färm, M. Kemell, X. Tu, T.Y. Liow, G.Q. Lo, M. Ritala, M. Leskelä, S. Honkanen, H. Lipsanen, and Z. Sun, "Slot waveguide ring resonators coated by an atomic layer deposited organic/inorganic nanolaminate," Opt. Express 23, 26940-26951 (2015) [2] L. D. Salmi, E. Puukilainen, M. Vehkamäki, M. Heikkilä, and M. Ritala, "Atomic layer deposition of Ta2O5/polyimide nanolaminates," Chem. Vap. Deposition 15, 221-226 (2009). [3] S. Morino, T. Yamashita, K. Horie, T. Wada, and H. Sasabe, "Third-order nonlinear optical properties of aromatic polyisoimides," React. Funct. Polym. 44, 183-188 (2000). [4] C.-Y. Tai, J. Wilkinson, N. Perney, M. Netti, F. Cattaneo, C. Finlayson, and J. Baumberg, "Determination of nonlinear refractive index in a Ta2O5 rib waveguide using self-phase modulation," Opt. Express 12, 5110-5116 (2004).

  10. High energy particle collisions and geometry of horizon

    NASA Astrophysics Data System (ADS)

    Zaslavskii, O. B.

    2016-06-01

    We consider collision of two geodesic particles near the lightlike surface (black hole horizon or naked singularity) of such an axially symmetric rotating or static metric that the coefficient gϕϕ → 0 on this surface. It is shown that the energy in the center of mass frame Ec.m. is indefinitely large even without fine-tuning of particles’ parameters. Kinematically, this is the collision between two rapid particles that approach the horizon almost with the speed of light but at different angles (or they align along the normal to the horizon too slowly). The latter is the reason why the relative velocity tends to that of light, hence to high Ec.m.. Our approach is model-independent. It relies on general properties of geometry and is insensitive to the details of material source that supports the geometries of the type under consideration. For several particular models (the stringy black hole, the Brans-Dicke analogue of the Schwarzschild metric and the Janis-Newman-Winicour one) we recover the results found in literature previously.

  11. Gravitational lensing by rotating naked singularities

    SciTech Connect

    Gyulchev, Galin N.; Yazadjiev, Stoytcho S.

    2008-10-15

    We model massive compact objects in galactic nuclei as stationary, axially symmetric naked singularities in the Einstein-massless scalar field theory and study the resulting gravitational lensing. In the weak deflection limit we study analytically the position of the two weak field images, the corresponding signed and absolute magnifications as well as the centroid up to post-Newtonian order. We show that there are static post-Newtonian corrections to the signed magnification and their sum as well as to the critical curves, which are functions of the scalar charge. The shift of the critical curves as a function of the lens angular momentum is found, and it is shown that they decrease slightly for the weakly naked and vastly for the strongly naked singularities with the increase of the scalar charge. The pointlike caustics drift away from the optical axis and do not depend on the scalar charge. In the strong deflection limit approximation, we compute numerically the position of the relativistic images and their separability for weakly naked singularities. All of the lensing quantities are compared to particular cases as Schwarzschild and Kerr black holes as well as Janis-Newman-Winicour naked singularities.

  12. Experimental setup for investigation of nanoclusters at cryogenic temperatures by electron spin resonance and optical spectroscopies

    NASA Astrophysics Data System (ADS)

    Mao, S.; Meraki, A.; McColgan, P. T.; Shemelin, V.; Khmelenko, V. V.; Lee, D. M.

    2014-07-01

    We present the design and performance of an experimental setup for simultaneous electron spin resonance (ESR) and optical studies of nanoclusters with stabilized free radicals at cryogenic temperatures. A gas mixture of impurities and helium after passing through a RF discharge for dissociation of molecules is directed onto the surface of superfluid helium to form the nanoclusters of impurities. A specially designed ESR cavity operated in the TE011 mode allows optical access to the sample. The cavity is incorporated into a homemade insert which is placed inside a variable temperature insert of a Janis 4He cryostat. The temperature range for sample investigation is 1.25-300 K. A Bruker EPR 300E and Andor 500i optical spectrograph incorporated with a Newton EMCCD camera are used for ESR and optical registration, respectively. The current experimental system makes it possible to study the ESR and optical spectra of impurity-helium condensates simultaneously. The setup allows a broad range of research at low temperatures including optically detected magnetic resonance, studies of chemical processes of the active species produced by photolysis in solid matrices, and investigations of nanoclusters produced by laser ablation in superfluid helium.

  13. Experimental setup for investigation of nanoclusters at cryogenic temperatures by electron spin resonance and optical spectroscopies

    SciTech Connect

    Mao, S. Meraki, A.; McColgan, P. T.; Khmelenko, V. V.; Lee, D. M.; Shemelin, V.

    2014-07-15

    We present the design and performance of an experimental setup for simultaneous electron spin resonance (ESR) and optical studies of nanoclusters with stabilized free radicals at cryogenic temperatures. A gas mixture of impurities and helium after passing through a RF discharge for dissociation of molecules is directed onto the surface of superfluid helium to form the nanoclusters of impurities. A specially designed ESR cavity operated in the TE{sub 011} mode allows optical access to the sample. The cavity is incorporated into a homemade insert which is placed inside a variable temperature insert of a Janis {sup 4}He cryostat. The temperature range for sample investigation is 1.25–300 K. A Bruker EPR 300E and Andor 500i optical spectrograph incorporated with a Newton EMCCD camera are used for ESR and optical registration, respectively. The current experimental system makes it possible to study the ESR and optical spectra of impurity-helium condensates simultaneously. The setup allows a broad range of research at low temperatures including optically detected magnetic resonance, studies of chemical processes of the active species produced by photolysis in solid matrices, and investigations of nanoclusters produced by laser ablation in superfluid helium.

  14. The Power of Water

    NASA Astrophysics Data System (ADS)

    Petrova, Zhaneta; Miteva, Kamelia

    2013-04-01

    The Power of Water Zh. Petrova, K. Miteva Bio Games, Sofia, Bulgaria (petrova.jani@gmail.com; miteva.kamelia@gmail.com) Lessons "The Power of Water" Due to our belief in the initial creativity of the children and their capacity for discover and perceive logically the world, we consider that the primary and even the pre-school learning have a significant influence in the process of suggesting the idea of respect to the natural forces. These classroom activities include a variety of hand- and self-made simulation models with natural materials and toys which lead the children to easy understanding of what could 'friendly' water do and how powerful, dangerous and not-friendly it could be. During the lessons the children draw their own conclusions of the causes and possible solutions of natural hazards caused by water in each of its forms - avalanches, inundations, floods, the water influence in activation of landslides. The children make on their own some of the models and test them via simulations. In the end they discuss what they have learned in groups.

  15. The K-8 Aeronautics Internet Testbook: Project Plan-Year 3

    NASA Technical Reports Server (NTRS)

    Pallis, Jani Macari

    1997-01-01

    The Project Plan - Year 3 includes: the major tasks and milestones, the assignment of tasks, and the key personnel assigned to each task, a description of the milestone and major task, and the deliverables for the project. Milestones have project numbers ending in "0.0", such as "25.0.0 Phase III Development". Major tasks under that milestone begin with the same first number such as, "25.0.1 Develop Future Of Aeronautics". The assignment of tasks included in the Year 3 project plan contains the names of the key personnel responsible for the task and others participating on the task. Although the PI has the overall and ultimately responsible for all the tasks and milestones, the name of the first individual on a task or milestone is the person responsible for that task. Other names listed under that task will be participating on the task. Since there are two individuals at Cislunar Aerospace, Inc. with the name "J. Pallis", the principal investigator, Jani Macari Pallis is designated as PI in the Project Plan and James Pallis is designated as J. Pallis.

  16. Susan Nolen-Hoeksema (1959-2013).

    PubMed

    Kaslow, Nadine J; Hilt, Lori; Wisco, Blair E; Brownell, Kelly D

    2013-01-01

    Presents an obituary for Susan Nolen-Hoeksema. Susan received her bachelor's degree from Yale University and her doctorate in clinical psychology from the University of Pennsylvania. Her undergraduate and graduate school mentors were Irving Janis, Robert Sternberg, and Martin Seligman. Susan began her career at Stanford University, where she became a tenured associate professor in 1993, and moved to the University of Michigan, where she was promoted to the rank of professor and directed the Institute for Research on Women and Gender. Susan joined the Yale University Department of Psychology in 2004 as a professor and served as its chair and director of graduate studies. Few words can capture Susan's masterful approach to research, which balanced creativity with pragmatism. A pioneer in the study of depression and a leading figure in research on sex differences in depression, she transformed clinical psychology with her research. Raised in the small town of Stonington, Illinois, Susan acquired a decency, kindness, and strength of character that lasted her lifetime. Despite her academic achievements and stature in the field, she treated everyone with respect and dignity. She was remarkable in her ability to support people through difficult circumstances, fairly treat all individuals, and be a kind and dedicated mentor and colleague to those of us fortunate enough to know her. Our field is richer for her presence, and her untimely death is a tragic loss. There could be no better colleague and friend. (PsycINFO Database Record (c) 2013 APA, all rights reserved). PMID:23895616

  17. Non-singular rotating black hole with a time delay in the center

    NASA Astrophysics Data System (ADS)

    Lorenzo, Tommaso De; Giusti, Andrea; Speziale, Simone

    2016-03-01

    As proposed by Bambi and Modesto, rotating non-singular black holes can be constructed via the Newman-Janis algorithm. Here we show that if one starts with a modified Hayward black hole with a time delay in the centre, the algorithm succeeds in producing a rotating metric, but curvature divergences reappear. To preserve finiteness, the time delay must be introduced directly at the level of the non-singular rotating metric. This is possible thanks to the deformation of the inner stationarity limit surface caused by the regularisation, and in more than one way. We outline three different possibilities, distinguished by the angular velocity of the event horizon. Along the way, we provide additional results on the Bambi-Modesto rotating Hayward metric, such as the structure of the regularisation occurring at the centre, the behaviour of the quantum gravity scale alike an electric charge in decreasing the angular momentum of the extremal black hole configuration, or details on the deformation of the ergosphere.

  18. Revision of the Gonioctena nivosa species-group (Coleoptera, Chrysomelidae, Chrysomelinae) in the Holarctic region, with descriptions of two new species

    PubMed Central

    Cho, Hee-Wook; Kippenberg, Horst; Borowiec, Lech

    2016-01-01

    Abstract The Gonioctena nivosa species-group of the genus Gonioctena Chevrolat, 1836 is defined and reviewed. It contains six species including two new to science: Gonioctena gracilicornis (Kraatz, 1879), Gonioctena nivosa (Suffrian, 1851), Gonioctena norvegica (Strand, 1936), Gonioctena springlovae (Bechyně, 1948), Gonioctena amurensis Cho & Borowiec, sp. n. and Gonioctena jani Cho & Borowiec, sp. n. Six new synonyms are proposed: Gonioctena nivosa (= Gonioctena arctica alberta Brown, 1952, syn. n., Phytodecta linnaeana bergrothi Jacobson, 1901, syn. n., Phytodecta linnaeanus var. mutatus Achard, 1924, syn. n., Phytodecta linnaeanus var. simplex Achard, 1924, syn. n. and Phytodecta nivosa var. cedehensis Ronchetti, 1922, syn. n.) and Gonioctena norvegica (= Gonioctena janovskii Medvedev, 1976, syn. n.). Phytodecta flavicornis var. limbatipennis Achard, 1924 and Phytodecta nivosa var. bicolor Heyden, 1883 are removed from synonymy with Gonioctena nivosa (Suffrian, 1851) and are synonymized with Gonioctena flavicornis (Suffrian, 1851). Distribution maps, a key to species, color variation, geographic variation of male genitalia and host plants are provided. Ovoviviparity is newly recorded in Gonioctena gracilicornis and Gonioctena nivosa. Lectotypes are designated for Gonioctena affinis, Gonioctena arctica, Gonioctena linnaeana bergrothi and Gonioctena nivosa. PMID:27408579

  19. Newtonian analogue of static general relativistic spacetimes: An extension to naked singularities

    NASA Astrophysics Data System (ADS)

    Ghosh, Shubhrangshu; Sarkar, Tamal; Bhadra, Arunava

    2015-10-01

    We formulate a generic Newtonian-like analogous potential for static spherically symmetric general relativistic (GR) spacetime and subsequently derived proper Newtonian-like analogous potential corresponding to Janis-Newman-Winicour (JNW) and Reissner-Nordström (RN) spacetimes, both exhibiting naked singularities. The derived potentials were found to reproduce the entire GR features including the orbital dynamics of the test particle motion and the orbital trajectories, with precise accuracy. The nature of the particle orbital dynamics including their trajectory profiles in JNW and RN geometries show altogether different behaviors with distinctive traits as compared to the nature of particle dynamics in Schwarzschild geometry. Exploiting the Newtonian-like analogous potentials, we found that the radiative efficiency of a geometrically thin and optically thick Keplerian accretion disk around naked singularities corresponding to both JNW and RN geometries, in general, is always higher than that for Schwarzschild geometry. The derived potentials would thus be useful to study astrophysical processes, especially to investigate more complex accretion phenomena in active galactic nuclei (AGNs) or in x-ray binaries (XRBs) in the presence of naked singularities and thereby to explore any noticeable differences in their observational features from those in the presence of black holes (BHs) to ascertain outstanding debatable issues relating to gravity—whether the end state of gravitational collapse in our physical Universe renders BH or naked singularity.

  20. Regular rotating de Sitter–Kerr black holes and solitons

    NASA Astrophysics Data System (ADS)

    Dymnikova, Irina; Galaktionov, Evgeny

    2016-07-01

    We study the basic generic properties of the class of regular rotating solutions asymptotically Kerr for a distant observer, obtained with using the Gürses–Gürsey algorithm from regular spherically symmetric solutions specified by {T}tt={T}rr which belong to the Kerr–Schild metrics. All regular solutions obtained with the Newman–Janis complex translation from the known spherical solutions, belong to this class. Spherical solutions with {T}tt={T}rr satisfying the weak energy condition (WEC), have obligatory de Sitter center. Rotation transforms the de Sitter center into the interior de Sitter vacuum disk. Regular de Sitter–Kerr solutions have at most two horizons and two ergospheres, and two different kinds of interiors. In the case when an original spherical solution satisfies the dominant energy condition, there can exist the interior de Sitter vacuum { S }-surface which contains the de Sitter disk as a bridge. The WEC is violated in the internal cavities between the { S }-surface and the disk, which are filled thus with a phantom fluid. In the case when a related spherical solution violates the dominant energy condition, vacuum interior of a rotating solution reduces to the de Sitter disk only.

  1. Importance and usefulness of evaluating self-esteem in children

    PubMed Central

    2012-01-01

    Self-esteem is the "feeling of self-appreciation" and is an indispensable emotion for people to adapt to society and live their lives. For children, in particular, the environment in which they are raised contributes profoundly to the development of their self-esteem, which in turn helps them to adapt better to society. Various psychologists have provided definitions of self-esteem, and examined methods of objectively evaluating self-esteem. Questionnaire-style assessment methods for adult include Rosenberg Self-Esteem Scale and Janis-Field Feeling of Inadequacy Scale, and these for children include Coopersmith Self-Esteem Inventory, Pope's 5-Scale Test of Self-Esteem for children, and Kid- KINDL®. Other methods include Ziller Social Self-Esteem Scale and Implicit Association Test. The development of children's self-esteem is heavily influenced by their environment, that is, their homes, neighborhoods, and schools. Children with damaged self-esteem are at risk of developing psychological and social problems, which hinders recovery from low self-esteem. Thus, to recover low self-esteem, it is important for children to accumulate a series of successful experiences to create a positive concept of self. Evaluating children's self-esteem can be an effective method for understanding their past and present circumstances, and useful to treat for children with psychosomatic disorders. PMID:22433387

  2. Importance and usefulness of evaluating self-esteem in children.

    PubMed

    Hosogi, Mizuho; Okada, Ayumi; Fujii, Chikako; Noguchi, Keizou; Watanabe, Kumi

    2012-01-01

    Self-esteem is the "feeling of self-appreciation" and is an indispensable emotion for people to adapt to society and live their lives. For children, in particular, the environment in which they are raised contributes profoundly to the development of their self-esteem, which in turn helps them to adapt better to society. Various psychologists have provided definitions of self-esteem, and examined methods of objectively evaluating self-esteem. Questionnaire-style assessment methods for adult include Rosenberg Self-Esteem Scale and Janis-Field Feeling of Inadequacy Scale, and these for children include Coopersmith Self-Esteem Inventory, Pope's 5-Scale Test of Self-Esteem for children, and Kid- KINDL®. Other methods include Ziller Social Self-Esteem Scale and Implicit Association Test. The development of children's self-esteem is heavily influenced by their environment, that is, their homes, neighborhoods, and schools. Children with damaged self-esteem are at risk of developing psychological and social problems, which hinders recovery from low self-esteem. Thus, to recover low self-esteem, it is important for children to accumulate a series of successful experiences to create a positive concept of self. Evaluating children's self-esteem can be an effective method for understanding their past and present circumstances, and useful to treat for children with psychosomatic disorders. PMID:22433387

  3. Emotional vulnerability and coping styles for resolving decisional conflict.

    PubMed

    Umeh, Kanayo; Omari-Asor, Lorraine

    2011-01-01

    This investigation supplements the study by D. Bouckenooghe, K. Vanderheyden, S. Mestdagh, and S. van Laethem (2007) on the role of cognitive dispositions in coping patterns for resolving decisional conflict. Literature suggests emotional vulnerabilities may significantly affect decision making. Thus, the present authors assessed the role of trait anxiety and depression in decision coping styles as specified by I. L. Janis and L. Mann's (1977) conflict-theory model. The participants--100 young adults--completed the Taylor Manifest Anxiety Scale (J. A. Taylor, 1953), Beck's Depression Inventory (A. T. Beck, R. A. Steer, & G. M. Garbin, 1988), and the Melbourne Decision-Making Questionnaire (L. Mann et al., 1998), which measures 4 coping strategies: vigilance, buck-passing, procrastination, and hypervigilance. Hierarchical multiple regression analysis, controlling for demographic and lifestyle factors, revealed trait anxiety and depression as significant predictors of procrastination and hypervigilance. Depression failed to predict buck-passing but functioned as an important moderator variable whereby trait anxiety better predicted hypervigilance in nondepressed participants. Consistent with past research, emotional dispositions failed to predict vigilance. Overall, these findings implicate emotional vulnerabilities in the quality of decision making but raise important questions about their unique and conditional effects. PMID:21834323

  4. Erratum: Erratum to: Non-singular rotating black hole with a time delay in the center

    NASA Astrophysics Data System (ADS)

    De Lorenzo, Tommaso; Giusti, Andrea; Speziale, Simone

    2016-08-01

    As proposed by Bambi and Modesto, rotating non-singular black holes can be constructed via the Newman-Janis algorithm. Here we show that if one starts with a modified Hayward black hole with a time delay in the centre, the algorithm succeeds in producing a rotating metric, but curvature divergences reappear. To preserve finiteness, the time delay must be introduced directly at the level of the non-singular rotating metric. This is possible thanks to the deformation of the inner stationarity limit surface caused by the regularisation, and in more than one way. We outline three different possibilities, distinguished by the angular velocity of the event horizon. Along the way, we provide additional results on the Bambi-Modesto rotating Hayward metric, such as the structure of the regularisation occurring at the centre, the behaviour of the quantum gravity scale alike an electric charge in decreasing the angular momentum of the extremal black hole configuration, or details on the deformation of the ergosphere.

  5. The Intravenous Laser Blood Irradiation in Chronic Pain and Fibromyalgia

    PubMed Central

    Momenzadeh, Sirous; Abbasi, Mohammadzaki; Ebadifar, Asghar; Aryani, Mohammadreza; Bayrami, Jafar; Nematollahi, Fatemeh

    2015-01-01

    Intravenous laser blood irradiation was first introduced into therapy by the Soviet scientists EN.Meschalkin and VS.Sergiewski in 1981. Originally this method was developed for the treatment of cardiovascular diseases. Improvement of rheologic properties of the blood as well as improvement of microcirculation and reduction of the area of infarction has been proved. Further, reduction of dysrhythmia and sudden cardiac death was achieved. At first, only the Helium-Neon laser (632.8 nm) was used in this therapy. For that, a power of 1-3mW and a period of exposure of 20-60 minutes were applied. The treatments were carried out once or twice a day up to ten appointments in all1. In the years after, many, and for the most part Russian studies showed that helium-neon laser had various effects on many organs and on the hematologic and immunologic system. The studies were published mainly in Russian which were little known in the West because of decades of political separation, and were regarded with disapproval. Besides clinical research and application for patients, the cell biological basis was developed by the Estonian cell biologist Tiina Karu at the same time. An abstract is to be found in her work "The Science of Low-Power Laser-Therapy" PMID:25699161

  6. The intravenous laser blood irradiation in chronic pain and fibromyalgia.

    PubMed

    Momenzadeh, Sirous; Abbasi, Mohammadzaki; Ebadifar, Asghar; Aryani, Mohammadreza; Bayrami, Jafar; Nematollahi, Fatemeh

    2015-01-01

    Intravenous laser blood irradiation was first introduced into therapy by the Soviet scientists EN.Meschalkin and VS.Sergiewski in 1981. Originally this method was developed for the treatment of cardiovascular diseases. Improvement of rheologic properties of the blood as well as improvement of microcirculation and reduction of the area of infarction has been proved. Further, reduction of dysrhythmia and sudden cardiac death was achieved. At first, only the Helium-Neon laser (632.8 nm) was used in this therapy. For that, a power of 1-3mW and a period of exposure of 20-60 minutes were applied. The treatments were carried out once or twice a day up to ten appointments in all1. In the years after, many, and for the most part Russian studies showed that helium-neon laser had various effects on many organs and on the hematologic and immunologic system. The studies were published mainly in Russian which were little known in the West because of decades of political separation, and were regarded with disapproval. Besides clinical research and application for patients, the cell biological basis was developed by the Estonian cell biologist Tiina Karu at the same time. An abstract is to be found in her work "The Science of Low-Power Laser-Therapy" PMID:25699161

  7. Upper Devonian vertebrate taphonomy and sedimentology from the Klunas fossil site, Tervete Formation, Latvia

    NASA Astrophysics Data System (ADS)

    Vasiļkova, J.; Lukševičs, E.; Stinkulis, Ä.¢.; Zupinš, I.

    2012-04-01

    The deposits of the Tervete Formation, Famennian Stage of Latvia, comprising weakly cemented sandstone and sand intercalated with dolomitic marls, siltstone and clay, have been traditionally interpreted as having formed in a shallow, rather restricted sea with lowered salinity. During seven field seasons the excavations took place in the south-western part of Latvia, at the Klunas site, and resulted in extensive palaeontological and sedimentological data. The taphonomical analysis has been performed, having evaluated the size, sorting, orientation of the fossils, articulation and skeletal preservation as well as the degree of fragmentation and abrasion. The sedimentological analysis involved interpretation of sedimentary structures, palaeocurrent direction reconstruction, grain-size analysis and approximate water depth calculations. The vertebrate assemblage of the Klunas site represents all known taxa of the Sparnene Regional Stage of the Baltic Devonian, comprising placoderms Bothriolepis ornata Eichwald, B. jani Lukševičs, Phyllolepis tolli Vasiliauskas, Dunkleosteus sp. and Chelyophorus sp., sarcopterygians Holoptychius nobilissimus Agassiz, Platycephalichthys skuenicus Vorobyeva, Cryptolepis sp., Conchodus sp., Glyptopomus ? sp., "Strunius" ? sp., and Dipterus sp., as well as an undetermined actinopterygian. Placoderms Bothriolepis ornata and B. jani dominate the assemblage. The fossils are represented in the main by fully disarticulated placoderm plates and plate fragments, sarcopterygian scales and teeth, rarely bones of the head and shoulder girdle, and acanthodian spines and scales. The characteristic feature is the great amount of fragmentary remains several times exceeding the number of intact bones. The horizontal distribution of the bones over the studied area is not homogenous, distinct zones of increased or decreased density of fossils can be traced. Zones of the increased density usually contain many elements of various sizes, whereas zones of the

  8. The Fast Alternative Cryogenic Experiment Testbed

    NASA Technical Reports Server (NTRS)

    Nash, Alfred; Holmes, Warren

    2000-01-01

    One of the challenges in the area of cryogenics for space exploration in the next millennium is providing the capability for inexpensive, frequent, access to space. Faced with this challenge during the International Space Station (ISS) build era, when other Space Shuttle manifesting opportunities are unavailable, a "proof of concept" cryostat has been developed to demonstrate the ability to accommodate low temperature science investigations within the constraints of the Hitchhiker siderail carrier. The Hitchhiker siderail carrier is available on a "mass available" basis during the ISS build era. In fact, several hitchhiker payloads flew with the deployment of the Unity module. Hitchhiker siderail carrier payloads have historically flown an average of about four times a year. A hybrid Solid Neon - Superfluid Helium cryostat has been developed with Janis Research Company to accommodate instruments of 16.5 cm diameter and 30 cm. length. This hybrid approach was taken in part to provide adequate on-orbit lifetime for instruments with high (conducted) heat loads from the instrumentation wiring. Mass, volume, lifetime and the launch hold scenario were all design drivers. In addition, with Ball Aerospace and Technologies Corporation, a multichannel VME architecture Germanium Resistance Thermometer (GRT) readout and heater control servo system has been developed. In a flight system, the cryostat and electronics payloads would be umbilically attached in a paired Hitchhiker siderail mount, and permit on-orbit command and telemetry capability. The results of performance tests of both the cryostat, and a helium sample instrument will be presented. The instrument features a self contained, miniaturized, nano-Kelvin resolution High Resolution Thermometer (HRT). This high level of thermal resolution is achieved through the utilization of a dc Superconducting Quantum Interference Device (SQUID). Although developed for the Low Temperature Microgravity Fundamental Physics

  9. A Silent Safety Program

    NASA Technical Reports Server (NTRS)

    Goodin, James Ronald

    2006-01-01

    NASA's Columbia Accident Investigation Board (CAIB) referred 8 times to the NASA "Silent Safety Program." This term, "Silent Safety Program" was not an original observation but first appeared in the Rogers Commission's Investigation of the Challenger Mishap. The CAIB on page 183 of its report in the paragraph titled 'Encouraging Minority Opinion,' stated "The Naval Reactor Program encourages minority opinions and "bad news." Leaders continually emphasize that when no minority opinions are present, the responsibility for a thorough and critical examination falls to management. . . Board interviews revealed that it is difficult for minority and dissenting opinions to percolate up through the agency's hierarchy. . ." The first question and perhaps the only question is - what is a silent safety program? Well, a silent safety program may be the same as the dog that didn't bark in Sherlock Holmes' "Adventure of the Silver Blaze" because system safety should behave as a devil's advocate for the program barking on every occasion to insure a critical review inclusion. This paper evaluates the NASA safety program and provides suggestions to prevent the recurrence of the silent safety program alluded to in the Challenger Mishap Investigation. Specifically targeted in the CAM report, "The checks and balances the safety system was meant to provide were not working." A silent system safety program is not unique to NASA but could emerge in any and every organization. Principles developed by Irving Janis in his book, Groupthink, listed criteria used to evaluate an organization's cultural attributes that allows a silent safety program to evolve. If evidence validates Jams's criteria, then Jams's recommendations for preventing groupthink can also be used to improve a critical evaluation and thus prevent the development of a silent safety program.

  10. Study of Sperm Reproductive Parameters in Mature Zanjani Viper

    PubMed Central

    Moshiri, Malihe; Todehdehghan, Fatemeh; Shiravi, Abdolhossein

    2014-01-01

    Objective Zanjani viper (Vipera albicornuta) is an endemic venomous snake in East Azerbai- jan Province, Iran which is medically important due to its application for antivenin production in the laboratory. We need to produce this snake in captivity. This study was conducted to charac- terize mature male Zanjani viper and to evaluate its sperm reproductive parameters. Materials and Methods This applied- descriptive study was conducted on twenty Zan- jani viper samples collected from Ag Dag Mountain in East Azarbaijan Province, Iran, between September and October 2010. After the snakes were anesthetized and sacrificed humanly, their morphometric specifications and sperm reproductive parameters, including concentration, motility, vitality, morphology, and survival time, were measured. Results Morphometric specifications and evaluation of sperms of the snake showed the following information: Zanjani male viper, body length of 73.65 ± 4.35 cm, tail length of 5.465 ± 0.48 cm, and mature snakes with testicular volumes of 0.61 ± 0.81 ml (right) and of 0.46 ± 0.17 ml (left). Our findings revealed average sperm concen- tration of 0.47 ± 0.1 ×106ml-1, motility of 49 -55 %, vitality of 46.11 ± 9.63 %, normal morphology of 61.71 ± 5.3%, and survival time of 6 ± 2 hours at the laboratory tem- perature. Statistical analyses were performed using Student’s t test for comparison of two values, and one-way ANOVA was applied where three values were compared. Conclusion Results suggest that mature Zanjani male viper with mature sperms in its vas deferens is present in late summer and early autumn seasons in Bostanabad County, Iran. PMID:24567940

  11. PREFACE: 7th EEIGM International Conference on Advanced Materials Research

    NASA Astrophysics Data System (ADS)

    Joffe, Roberts

    2013-12-01

    The 7th EEIGM Conference on Advanced Materials Research (AMR 2013) was held at Luleå University of Technology on the 21-22 March 2013 in Luleå, SWEDEN. This conference is intended as a meeting place for researchers involved in the EEIGM programme, in the 'Erasmus Mundus' Advanced Materials Science and Engineering Master programme (AMASE) and the 'Erasmus Mundus' Doctoral Programme in Materials Science and Engineering (DocMASE). This is great opportunity to present their on-going research in the various fields of Materials Science and Engineering, exchange ideas, strengthen co-operation as well as establish new contacts. More than 60 participants representing six countries attended the meeting, in total 26 oral talks and 19 posters were presented during two days. This issue of IOP Conference Series: Materials Science and Engineering presents a selection of articles from EEIGM-7 conference. Following tradition from previous EEIGM conferences, it represents the interdisciplinary nature of Materials Science and Engineering. The papers presented in this issue deal not only with basic research but also with applied problems of materials science. The presented topics include theoretical and experimental investigations on polymer composite materials (synthetic and bio-based), metallic materials and ceramics, as well as nano-materials of different kind. Special thanks should be directed to the senior staff of Division of Materials Science at LTU who agreed to review submitted papers and thus ensured high scientific level of content of this collection of papers. The following colleagues participated in the review process: Professor Lennart Walström, Professor Roberts Joffe, Professor Janis Varna, Associate Professor Marta-Lena Antti, Dr Esa Vuorinen, Professor Aji Mathew, Professor Alexander Soldatov, Dr Andrejs Purpurs, Dr Yvonne Aitomäki, Dr Robert Pederson. Roberts Joffe October 2013, Luleå Conference photograph EEIGM7 conference participants, 22 March 2013 The PDF

  12. Local conductivity enhancement due to the tetragonal domain structure in LaAlO3- SrTiO3 heterointerfaces

    NASA Astrophysics Data System (ADS)

    Moler, Kathryn

    2014-03-01

    Progress in the difficult task of growing oxide heterostructures has enabled the field of oxide interface engineering. The ability to control materials properties through interface engineering is demonstrated by the appearance of conductivity at the interface of certain insulators, most famously the {001}interface of the band insulators LaAlO3 (LAO) and TiO2-terminated SrTiO3 (STO). The prevailing explanation of conduction at the interface is electronic reconstruction due to a `polar catastrophe' in which charge migrates from the top LAO layer to the interface. Transport and other measurements in this system display a plethora of diverse physical phenomena. To better understand the interface conductivity, we used scanning superconducting quantum interference device (SQUID) microscopy to image the magnetic field locally generated by current in an interface. At low temperature, we found that the current flowed in conductive narrow paths oriented along the crystallographic axes, embedded in a less conductive background. The configuration of these paths changed upon thermal cycling above the STO cubic to tetragonal structural transition temperature, implying that the local conductivity is strongly modified by the STO tetragonal domain structure. In this talk, I will summarize these results and also report on measurements of conductivity and diamagnetism in related materials that firmly establish the influence of the STO tetragonal domains on electronic properties. Coauthors C. Bell, H.K. Sato, M. Hosoda, Y. Xie, Y. Hikita, & H.Y. Hwang (SIMES); R. Jany & C. Richter (Augsburg); C. Woltmann, G. Pfanzelt, & J. Mannhart (MP Stuttgart); B. Kalisky, E.M. Spanton, H. Noad, K.C. Nowack, A. Rosenberg, & J.R. Kirtley.

  13. Particle motion and Penrose processes around rotating regular black hole

    NASA Astrophysics Data System (ADS)

    Abdujabbarov, Ahmadjon

    2016-07-01

    The neutral particle motion around rotating regular black hole that was derived from the Ayón-Beato-García (ABG) black hole solution by the Newman-Janis algorithm in the preceding paper (Toshmatov et al., Phys. Rev. D, 89:104017, 2014) has been studied. The dependencies of the ISCO (innermost stable circular orbits along geodesics) and unstable orbits on the value of the electric charge of the rotating regular black hole have been shown. Energy extraction from the rotating regular black hole through various processes has been examined. We have found expression of the center of mass energy for the colliding neutral particles coming from infinity, based on the BSW (Baňados-Silk-West) mechanism. The electric charge Q of rotating regular black hole decreases the potential of the gravitational field as compared to the Kerr black hole and the particles demonstrate less bound energy at the circular geodesics. This causes an increase of efficiency of the energy extraction through BSW process in the presence of the electric charge Q from rotating regular black hole. Furthermore, we have studied the particle emission due to the BSW effect assuming that two neutral particles collide near the horizon of the rotating regular extremal black hole and produce another two particles. We have shown that efficiency of the energy extraction is less than the value 146.6 % being valid for the Kerr black hole. It has been also demonstrated that the efficiency of the energy extraction from the rotating regular black hole via the Penrose process decreases with the increase of the electric charge Q and is smaller in comparison to 20.7 % which is the value for the extreme Kerr black hole with the specific angular momentum a= M.

  14. A preliminary report on noble gas isotope analyses using the Helix-MC multi-collector mass spectrometer

    NASA Astrophysics Data System (ADS)

    Honda, M.; Zhang, X.; Phillips, D.; Szczepanski, S.; Deerberg, M.; Hamilton, D.; Krummen, M.; Schwieters, J.

    2013-12-01

    Analyses of noble gas isotopes by multi-collector mass spectrometry substantially improve measurement precision and accuracy, with the potential to revolutionise applications to cosmo-geo-sciences. The Helix-MC noble gas mass spectrometer manufactured by Thermo-Fisher is a 350mm, 120 degree extended geometry, high resolution, multi-collector mass spectrometer for the simultaneous analysis of noble gas isotopes. The detector array includes a fixed axial (Ax) detector, 2 adjustable high mass (H1 and H2) detectors and 2 adjustable low mass (L1 and L2) detectors. Each detector is equipped with a Faraday/ion counting multiplier CFM (Combined Faraday and CDD Multiplier) detector. Mass resolution and mass resolving power on the H2, Ax and L2 detectors of the Helix-MC installed at the Australian National University (ANU) are approximately 1,800 and 8,000, respectively. The noble gas handling system on-line to the Helix-MC consists of: (1) a resistively-heated, double-vacuum, tantalum furnace system, (2) air actuated vacuum crusher, (3) Photon-Machines diode laser heating system, (4) Janis He cryogenic trap assembly, (5) gas purification system and (6) standard gas pipette tanks, which are totally automated and controlled by the Qtegra software platform developed by Thermo-Fisher. Eleven repeat measurements of atmospheric Ar using the H2 Faraday (1E11 ohm resistor) and L2 CDD collectors on the Helix-MC, yield a mean 40Ar/36Ar ratio of 322.09 +- 0.28 (0.089%) with a 4,700 fA 40Ar beam current. This result compares favourably with the precision achieved by the Argus VI at the University of Melbourne (318.12 +- 0.17; 0.052%; n = 10) with a similar beam size of 4,200 fA. The high mass resolution of the L2 collector permits complete separation of the 36Ar and interfering 3 x 12C (required mass resolution (MR) of 1,100) and partial separation of H35Cl (MR = 3,900). This capability enables evaluation of the significance of Ar isotopic interferences related to the correction of

  15. Scalar fields and particle accelerators

    NASA Astrophysics Data System (ADS)

    Sultana, Joseph; Bose, Benjamin

    2015-06-01

    The phenomenon discovered in 2009 by Bañados, Silk and West where particle collisions can achieve arbitrary high center-of-mass (c.m.) energies close to the event horizon of an extreme Kerr black hole, has generated a lot of interest. Although rotation seemed to be an essential requirement, it was later shown that arbitrary high energies can also be achieved for collisions between radially moving particles near the horizon of the electrically charged extreme Reissner-Nordström black hole. Recently Patil and Joshi claimed that instead of spinning up the black hole one can also crank up the c.m. energy of particle collisions by "charging up" a static black hole with a massless scalar field. In this regard they showed that infinite energies can be attained in the vicinity of the naked singularity of the Janis-Newman-Wincour (JNW) spacetime, which contains a massless scalar field that also becomes infinite at the position of the curvature singularity. In this study we show that Patil and Joshi's claim does not apply for other static black hole systems endowed with a massless scalar field. In particular we consider the well-known Bekenstein black hole and the recently discovered Martínez-Troncoso-Zanelli black hole, and show that the expression of the c.m. energy for particle collisions near the event horizons of these black holes is no different than the corresponding case with vanishing scalar field represented by the Schwarzschild solution. Moreover by studying the motion of scalar test charges that interact with the background scalar field in these black hole spacetimes we show that the resulting c.m. energies are even smaller than in the case of free particles. This shows that the infinite energies obtained by Patil and Joshi may not be due to the fact that the black hole contains a massless scalar field, but may be instead related to the geometry of the naked singularity in the JNW spacetime. An analogous case of infinite c.m. energy in the vicinity of a naked

  16. Preface

    NASA Astrophysics Data System (ADS)

    Muiznieks, A.

    2005-06-01

    The Workshop "Use of Magnetic Fields in Crystal Growth" was organized by the Institute of Physics of University of Latvia together with the Department of Physics of University of Latvia and held on December 5-6, 2004, at the Department of Physics of University of Latvia, 8 Zellu str., Riga. The workshop was organized in the framework of the supported by EU project "Development of the Institute of Physics of University of Latvia for European Centre of MagnetoHydroDynamics Research" (2003-2005, Research Programme: GROW-2001, coordinator of the project Dr. Janis Priede) and in the framework of the COST action P6, Magnetohydrodynamics, Working Group 2 "Use of Magnetic Fields in Crystal Growth" (coordinator asoc. prof. Dr. Andris Muiznieks, who was responsible for the workshop organization). The goal of the Workshop was to discuss the use of magnetic fields in crystal growth through mathematical analysis, numerical modeling and experimental investigations. Important part of reports was devoted to the crystal quality, e.g., occurrence and density of dislocations, distribution of dopants in semiconductors and growth stability. Other important aspects were: melt flow, turbulence, mass transport in the melt, melt flow stability and instability, shape of crystallization interface, etc. About 30 scientists from Latvia, Germany and the United Kingdom took part in the Workshop and 24 oral presentations were contributed. These presentations have shown the state of art in understanding the use of magnetic fields in crystal growth in such scientific centers as Forschungszentrum Rossendorf, Germany; Department of Physics, University of Latvia, Latvia; Institute for Electrothermal Processes, University of Hanover, Germany; Kristallographisches Institut, University of Freiburg, Germany; TU Bergakademie Freiberg, Institut fur NE-Metallurgie und Reinststoffe, Germany; Siltronic AG, Burghausen, Germany; Institute for Crystal Growth, Berlin, Germany; Coventry University, School of

  17. PREFACE: International Conference on Functional Materials and Nanotechnologies (FM&NT2012)

    NASA Astrophysics Data System (ADS)

    Sternberg, Andris; Muzikante, Inta; Sarakovskis, Anatolijs; Grinberga, Liga

    2012-08-01

    Organizing Committee sincerely hopes that the Conference gave all the participants new insights into the widespread development of functional materials and nanotechnologies and would enhance the circulation of the information released at the meeting. Inta Muzikante Andris Sternberg Liga Grinberga Anatolijs Sarakovskis Conference photograph The manuscripts are published thanks to the financial support from ERAF project 'Atbalsts starptautiskas sadarbibas projektiem zinatne un tehnologijas LU Cietvielu fizikas instituta' Nr.2010/0204/2DP/2.1.1.2.0./10/APIA/VIAA/010 Sponsors Sponsors flag Sponsors logo International Organizing Committee 1. Andris Sternberg (chairperson), Institute of Solid State Physics, University of Latvia, Latvia 2. Juras Banys, Vilnius University, Lithuania 3. Gunnar Borstel, University of Osnabrück, Germany 4. Niels E Christensen, University of Aarhus, Denmark 5. Robert A Evarestov, St. Petersburg State University, Russia 6. Claes-Goran Granqvist, Uppsala University, Sweden 7. Dag Høvik, The Research Council of Norway, Norway 8. Marco Kirm, Institute of Physics, University of Tartu, Estonia 9. Jiri Kulda, Institut Laue-Langevin, France 10. Witold Lojkowski, Institute of High Pressure Physics, Poland 11. Ergo Nommiste, University of Tartu, Estonia 12. Ingólfur Torbjörnsson, Icelandic Centre for Research, Iceland 13. Marcel H. Van de Voorde, University of Technology Delft, The Netherlands International Program Committee 1. Liga Grinberga (chairperson), Institute of Solid State Physics, University of Latvia, Latvia 2. Eugene Kotomin, Max Planck Institute for Solid State Research, Germany 3. Martins Rutkis, Institute of Solid State Physics, University of Latvia, Latvia 4. Inta Muzikante, Institute of Solid State Physics, University of Latvia, Latvia 5. Liga Berzina-Cimdina, Institute of Biomaterials and Biomechanics, Riga Technical University, Latvia 6. Janis Grabis, Institute of Inorganic Chemistry, Riga Technical University, Latvia 7. Linards Skuja

  18. Quantitative multiplex detection of biomarkers on a waveguide-based biosensor using quantum dots

    SciTech Connect

    Xie, Hongzhi; Mukundan, Harshini; Martinez, Jennifer S; Swanson, Basil I; Anderson, Aaron S; Grace, Kevin

    2009-01-01

    The quantitative, simultaneous detection of multiple biomarkers with high sensitivity and specificity is critical for biomedical diagnostics, drug discovery and biomarker characterization [Wilson 2006, Tok 2006, Straub 2005, Joos 2002, Jani 2000]. Detection systems relying on optical signal transduction are, in general, advantageous because they are fast, portable, inexpensive, sensitive, and have the potential for multiplex detection of analytes of interest. However, conventional immunoassays for the detection of biomarkers, such as the Enzyme Linked Immunosorbant Assays (ELISAs) are semi-quantitative, time consuming and insensitive. ELISA assays are also limited by high non-specific binding, especially when used with complex biological samples such as serum and urine (REF). Organic fluorophores that are commonly used in such applications lack photostability and possess a narrow Stoke's shift that makes simultaneous detection of multiple fluorophores with a single excitation source difficult, thereby restricting their use in multiplex assays. The above limitations with traditional assay platforms have resulted in the increased use of nanotechnology-based tools and techniques in the fields of medical imaging [ref], targeted drug delivery [Caruthers 2007, Liu 2007], and sensing [ref]. One such area of increasing interest is the use of semiconductor quantum dots (QDs) for biomedical research and diagnostics [Gao and Cui 2004, Voura 2004, Michalet 2005, Chan 2002, Jaiswal 2004, Gao 2005, Medintz 2005, So 2006 2006, Wu 2003]. Compared to organic dyes, QDs provide several advantages for use in immunoassay platforms, including broad absorption bands with high extinction coefficients, narrow and symmetric emission bands with high quantum yields, high photostablility, and a large Stokes shift [Michalet 2005, Gu 2002]. These features prompted the use of QDs as probes in biodetection [Michalet 2005, Medintz 2005]. For example, Jaiswal et al. reported long term multiple color

  19. Preface: Materiaux 2010

    NASA Astrophysics Data System (ADS)

    Cheikhrouhou, Abdelwaheb

    2012-02-01

    Ceramics, glasses, polymers Natural materials (phosphates, clay,...) Metallic materials, alloys, metallurgy,... Others (materials and environment, materials and energy, biomaterials,...) I want to thank the scientific committee, the organizing committee, the local committee and everyone who contributed to the organization of this meeting for their invaluable efforts in order to guarantee the complete success of this conference. Abdelwaheb Cheikhrouhou President of 'Tu-MRS' Chairman of the Conference 'MATERIAUX 2010' Conference photograph Committies Organizing Committee Chairman CHEIKHROUHOU Abdelwaheb (Faculté des Sciences de Sfax) Members ALAYA Sahbi (Faculté des Sciences de Gabès) BENNACEUR Raouf (Faculté des Sciences de Tunis) BEN SALEM Mohamed (Faculté des Sciences de Bizerte) CHEIKHROUHOU-KOUBAA Wissem (Faculté des Sciences de Sfax) EL JANI Belgacem (Faculté des Sciences de Monastir) EZZAOUIA Hatem (Centre de Recherches et de Technologies de l'Energie, Technopole de Borj Cédria) LAMLOUMI Jilani (Ecole Supérieure des Sciences et Techniques de Tunis) REZIG Bahri (Ecole Nationale d'Ingénieurs de Tunis) Local Committee Chairman CHEIKHROUHOU Abdelwaheb (Faculté des Sciences de Sfax) Members CHEIKHROUHOU-KOUBAA Wissem (Faculté des Sciences de Sfax) KOUBAA Mohamed (Institut Supérieur de Biotechnologie de Sfax) NJEH Anwar (Institut Préparatoire aux Etudes d'Ingénieurs de Sfax) BEN SALAH Issam (Faculté des Sciences de Sfax) TAKKALI Férid (Faculté des Sciences de Sfax) REGAIEG Yassin (Faculté des Sciences de Sfax) OTHMANI Safa (Faculté des Sciences de Sfax) MNASSRI Rafik (Faculté des Sciences de Sfax) Secretariat BEN GHOZLEN Afifa (Faculté des Sciences de Sfax) BOUGHARIOU Sana (Faculté des Sciences de Sfax) Scientific Committee M. ADDOU, Faculté des Sciences de Kénitra (Morocco) N. AMDOUNI, Faculté des Sciences de Tunis (Tunisia) M. BACCOUCHE, Faculté des Sciences d'Annaba (Algeria) H. BATIS, Faculté des Sciences de Tunis (Tunisia) A. BELAFHAL

  20. Motion4D-library extended

    NASA Astrophysics Data System (ADS)

    Müller, Thomas

    2011-06-01

    Chandrasekhar [6].HalilsoyWave: see Ref. [7].JaNeWi: Janis-Newman-Winicour metric, see Ref. [8].MinkowskiConformal: Minkowski metric in conformally rescaled coordinates.PTD_AI, PTD_AII, PTD_AIII, PTD_BI, PTD_BII, PTD_BIII, PTD_C Petrov-Type D - Levi-Civita spacetimes, see Ref. [7].PainleveGullstrand: Schwarzschild metric in Painlevé-Gullstrand coordinates, see Ref. [9].PlaneGravWave: Plane gravitational wave, see Ref. [10].SchwarzschildIsotropic: Schwarzschild metric in isotropic coordinates, see Ref. [11].SchwarzschildTortoise: Schwarzschild metric in tortoise coordinates, see Ref. [11].Sultana-Dyer: A black hole in the Einstein-de Sitter universe by Sultana and Dyer [12].TaubNUT: see Ref. [13]. The Christoffel symbols and the natural local tetrads of these new metrics are given in the Catalogue of Spacetimes, Ref. [14].To study the behavior of geodesics, it is often useful to determine an effective potential like in classical mechanics. For several metrics, we followed the Euler-Lagrangian approach as described by Rindler [10] and implemented an effective potential for a specific situation. As an example, consider the Lagrangian L=-αt˙+α-1r˙+r2φ˙ for timelike geodesics in the ϑ=π/2 hypersurface in the Schwarzschild spacetime with α=1-2m/r. The Euler-Lagrangian equations lead to the energy balance equation r˙+V(r)=k2 with the effective potential V(r)=(r-2m)(r2+h2)/r3 and the constants of motion k=αt˙ and h=r2φ˙. The constants of motion for a timelike geodesic that starts at (r=10m,φ=0) with initial direction ξ=π/4 with respect to the black hole direction and with initial velocity β=0.7 read k≈1.252 and h≈6.931. Then, from the energy balance equation we immediately obtain the radius of closest approach r≈5.927.Beside a standard Runge-Kutta fourth-order integrator and the integrators of the Gnu Scientific Library (GSL), we also implemented a standard Bulirsch-Stoer integrator.Running time: The test runs provided with the distribution require only a few

  1. Preface: phys. stat. sol. (b) 241/9

    NASA Astrophysics Data System (ADS)

    Morawetz, Klaus

    2004-07-01

    Modelling and Simulation in Molecular Systems, Mesoscopic Structures, and Material Science was the title of a workshop held at the University of Technology in Chemnitz from 21 to 23 April 2004. This workshop coincided with the 50th birthday of Michael Schreiber. Therefore, the idea to publish a special issue is supported by two good reasons. First, a topical collection is appropriate for giving an overview about a field and to initiate further studies. This is one intention of the present issue. Second, the birthday is a suitable occasion for reflecting on the status of the different fields where Michael Schreiber has been active himself. Motivated by the characteristic name of the workshop (MS4), which expresses the broad range of his activities, the contributions are grouped into three main chapters: Disorder and Interaction, Phase Transitions and Criticality, and Transport Properties.The first part starts with the currently intensively discussed topic of composite Fermions in the paper by B. Kramer et al. This method of rewriting correlations as new quasiparticles has amongst other things the merit of explaining such exciting phenomena as the fractional quantum Hall effect. The methodological questions of Ward identities, causality, and conservation laws are the focus of the systematic investiga-tion in the second article by V. Janis et al. which concentrates on the problem of disorder and configura-tional averaging. The interplay between disorder and correlation is treated in the third contribution by C. Schuster et al., where different theoretical methods are tested on the problem of Friedel oscillations within the one-dimensional Heisenberg and Hubbard model. In the next contribution, M. Berciu et al. focus on localization as one consequence of disorder. The localized and extended electronic states are treated, together with the magnetic degrees of freedom, like spin waves. One of the astonishing consequence of localiza-tion is the observation of resonant

  2. AAS 228: Day 4

    NASA Astrophysics Data System (ADS)

    Kohler, Susanna

    2016-06-01

    began the session by explaining his new models which trace the diffusive cooling of an initial supernova shock. His team has created an open source code, the SuperNova Explosion Code or SNEC, to allow others to explore a variety of explosion properties.Janie De La Rosa then spoke about her work on observing Type IIn supernovae (those with narrow emission lines in their spectra) at ultraviolet and optical wavelengths. These wavelengths are sensitive to progenitor models and the geometry of the surrounding material.Composite image of the supernova remnant Cassiopeia A, using data from the Chandra X-ray telescope, NASAs Spitzer Space Telescope, and ground-based facilities. [NASA/CXC/SAO]Following the exploration of progenitor geometry, Douglas C. Leonard spoke about his work in hunting for polarization in type IIP supernovae (those with long, plateaued light curves). A high degree of polarization implies asymmetry in the explosion itself, and he has been able to find such asymmetry in a number of type IIP supernovae. He pointed out that bubble-like structure (like what we see in the beautiful supernova remnant Cassiopeia A) might explain the polarization as well. Switching gears, Karri Kolijonen spoke about an interesting X-ray binary (a binary consistent of a compact object and star that emits strongly in X-rays) known as GS 1354-64. This pair has an extremely short orbital period of just two and a half days! He explained how an instability in the black holes accretion disk might explain a recent outburst in the system.Thomas Pannuti explained the basic morphologies of supernova remnants: shell, composite, and mixed. He has taken extensive, multiwavelength images of a mixed remnant known as W28 from radio through X-ray wavelengths. He notes that the radio masers in the remnant are offset from the X-ray light, although the significance of this is still an open question.Finally, Maria Dainotti wrapped up the session with a discussion of long duration GRBs as standard