WorldWideScience

Sample records for nanoscopically flat open-ended

  1. Open-ended education

    DEFF Research Database (Denmark)

    Nørgård, Rikke Toft; Paaskesen, Rikke Berggreen

    2016-01-01

    THE ARTICLE DESCRIBES OPEN-ENDED EDUCATION FOR 21ST CENTURY LEARNING AS THE COMING TOGETHER OF OPEN-ENDED TECHNOLOGY, OPEN-ENDED PROJECTS, AND OPEN-ENDED INSTITUTIONS IN WAYS THAT FOSTER AND PROMOTE FUTURE EDUCATION FOR CITIZENSHIP IN SOCIETY. THROUGH THE CASE OF THE CODING PIRATES FUTURE ISLAND......, THE ARTICLE DEMONSTRATES HOW OPEN-ENDED EDUCATION CAN BE PRACTICED TO FOSTER AND PROMOTE TECHNOLOGICAL IMAGINATION, ENTERPRISING, AND PARTICIPATION. THIS PRACTICE IS THEN DEVELOPED INTO A THEORETICAL MODEL FOR THE CONCEPT OF OPEN-ENDED EDUCATION AS A WAY OF AND FRAMEWORK FOR PRACTICING FUTURE EDUCATION FOR 21......ST CENTURY LEARNING WITH NEW TECHNOLOGIES. THE ARTICLE PRESENTS AN ANSWER TO THE CALL FOR 21ST CENTURY LEARNING AS THOROUGHLY COLLABORATIVE, COMMUNICATIVE, CREATIVE, AND CRITICALLY REFLECTIVE THROUGH THE CASE AND THE CONCEPT OF OPEN-ENDED EDUCATION. IT OUTLINES THE IMPLICATIONS OF THIS CALL...

  2. Open-Ended Evolution

    DEFF Research Database (Denmark)

    Taylor, Tim; Bedau, Mark A.; Channon, Alastair

    2016-01-01

    This report describes the First Workshop on Open-Ended Evolution: Recent Progress and Future Milestones (OEE1), held during the ECAL 2015 conference at the University of York, U.K., in July 2015. We briefly summarise the content of the talks and discussions and the workshop, and provide links...

  3. Open-Ended Electric Motor

    Science.gov (United States)

    Gould, Mauri

    1975-01-01

    Presents complete instructions for assembling an electric motor which does not require large amounts of power to operate and which is inexpensive as well as reliable. Several open-ended experiments with the motor are included as well as information for obtaining a kit of parts and instructions. (BR)

  4. The Open-Ended Approach Framework

    Science.gov (United States)

    Munroe, Lloyd

    2015-01-01

    This paper describes a pedagogical framework that teachers can use to support students who are engaged in solving open-ended problems, by explaining how two Japanese expert teachers successfully apply open-ended problems in their mathematics class. The Open-Ended Approach (OPA) framework consists of two main sections: Understanding Mathematical…

  5. Getting Started with Open-Ended Assessment

    Science.gov (United States)

    Leatham, Keith R.; Lawrence, Kathy; Mewborn, Denise S.

    2005-01-01

    The open-ended assessment item supports students in achieving mathematical understanding that the National Council of Teachers of Mathematics (NCTM) advocates. The items encourage students to demonstrate their understanding in creative and informative ways.

  6. KEEFEKTIFAN PENDEKATAN OPEN-ENDED DAN PROBLEM SOLVING PADA PEMBELAJARAN BANGUN RUANG SISI DATAR DI SMP

    Directory of Open Access Journals (Sweden)

    Nuning Melianingsih

    2015-11-01

    Full Text Available Penelitian ini bertujuan untuk menentukan keefektifan dan perbandingan keefektifan dari pendekatan open-ended dan problem solving pada pembelajaran bangun ruang sisi datar ditinjau dari pencapaian kemampuan penalaran, pemecahan masalah, dan komunikasi matematis. Penelitian ini adalah quasi experiment dengan desain pretest-posttest nonequivalent group design. Populasi penelitian mencakup seluruh siswa kelas VIII SMP Negeri 1 Pandak, Bantul, Yogyakarta. Selanjutnya dengan memilih secara acak dari keseluruhan kelas tersebut, terpilih kelas VIII F dan VIII G sebagai sampel penelitian. Untuk menguji keefektifan masing-masing pendekatan pembelajaran digunakan uji one sample t-test. Untuk menguji bahwa pendekatan open-ended lebih efektif daripada pendekatan problem solving, data dianalisis menggunakan MANOVA yang dilanjutkan dengan uji t-Bonferroni. Hasil penelitian menunjukkan bahwa kedua pendekatan pembelajaran efektif ditinjau dari masing-masing aspek, dan pendekatan open-ended lebih efektif daripada pendekatan problem solving pada pembelajaran bangun ruang sisi datar ditinjau dari pencapaian kemampuan penalaran, pemecahan masalah, dan komunikasi matematis di SMP. Kata Kunci: pendekatan open-ended, pendekatan problem solving, kemampuan penalaran, kemampuan pemecahan masalah, kemampuan komunikasi matematis   THE EFFECTIVENESS OF OPEN-ENDED AND PROBLEM SOLVING APPROACH IN MATTER OF FLAT SIDE CONSTRUCT IN JUNIOR HIGH SCHOOL Abstract The aims of this research are to decide the effectiveness and the comparison of the effectiveness of open-ended and problem solving approach toward matter of flat side construct lesson viewed from achivement of reasoning ability, problem solving and mathematics communication. This study was a quasi experimental study using the pretest-posttest nonequivalent group design. The research population covered the entire VIII class students’ of SMP Negeri 1 Pandak, Bantul, Yogyakarta. From the population, classes of VIII F and

  7. Open-end Investment Funds in Croatia

    Directory of Open Access Journals (Sweden)

    Bojan Morić Milovanović

    2006-03-01

    Full Text Available This work discusses investment funds in Croatia, with a particular emphasis on openend investment funds. After a short review of the development of the funds, the perception of the funds is analysed, as are the trends in total assets and in average yields. The degree of concentration of open-end investment funds is shown with statistical measures of concentration (the Gini Coefficient, the Lorenz Curve and concentration ratios. All these indicators show that the concentration is moderate to strong. The greatest yields are given by the equity funds, but these are also the most risky.

  8. The Physics of Open Ended Evolution

    Science.gov (United States)

    Adams, Alyssa M.

    What makes living systems different than non-living ones? Unfortunately this question is impossible to answer, at least currently. Instead, we must face computationally tangible questions based on our current understanding of physics, computation, information, and biology. Yet we have few insights into how living systems might quantifiably differ from their non-living counterparts, as in a mathematical foundation to explain away our observations of biological evolution, emergence, innovation, and organization. The development of a theory of living systems, if at all possible, demands a mathematical understanding of how data generated by complex biological systems changes over time. In addition, this theory ought to be broad enough as to not be constrained to an Earth-based biochemistry. In this dissertation, the philosophy of studying living systems from the perspective of traditional physics is first explored as a motivating discussion for subsequent research. Traditionally, we have often thought of the physical world from a bottom-up approach: things happening on a smaller scale aggregate into things happening on a larger scale. In addition, the laws of physics are generally considered static over time. Research suggests that biological evolution may follow dynamic laws that (at least in part) change as a function of the state of the system. Of the three featured research projects, cellular automata (CA) are used as a model to study certain aspects of living systems in two of them. These aspects include self-reference, open-ended evolution, local physical universality, subjectivity, and information processing. Open-ended evolution and local physical universality are attributed to the vast amount of innovation observed throughout biological evolution. Biological systems may distinguish themselves in terms of information processing and storage, not outside the theory of computation. The final research project concretely explores real-world phenomenon by means of

  9. Open-ended fusion devices and reactors

    International Nuclear Information System (INIS)

    Kawabe, T.; Nariai, H.

    1983-01-01

    Conceptual design studies on fusion reactors based upon open-ended confinement schemes, such as the tandem mirror and rf plugged cusp, have been carried out in Japan. These studies may be classified into two categories: near-term devices (Fusion Engineering Test Facility), and long-term fusion power recators. In the first category, a two-component cusp neutron source was proposed. In the second category, the GAMMA-R, a tandem-mirror power reactor, and the RFC-R, an axisymetric mirror and cusp, reactor studies are being conducted at the University of Tsukuba and the Institute of Plasma Physics. Mirror Fusion Engineering Facility parameters and a schematic are shown. The GAMMA-R central-cell design schematic is also shown

  10. Open-ended questions in sensory testing practice

    NARCIS (Netherlands)

    Piqueras Fiszman, B.

    2015-01-01

    Why use open-ended questions? This chapter provides an up-to-date overview on the use of open-ended questions in novel rapid sensory methodologies and the potential applications in which they could provide unique benefits. Next, the step-by-step process is described (from task performance to

  11. Review: Open-ended objects: A tool for brainstorming

    NARCIS (Netherlands)

    van den Broek, Egon

    2010-01-01

    Cruz and Gaudron sketch the concept of open-ended objects that are positioned as facilitating brainstorming workshops for human-computer interaction (HCI) purposes. Open-ended objects are characterized by four features: those that provide a preliminary experience, a tangible representation of a

  12. Technology of interdisciplinary open-ended designing in engineering education

    Science.gov (United States)

    Isaev, A. P.; Plotnikov, L. V.; Fomin, N. I.

    2017-11-01

    Author’s technology of interdisciplinary open-ended engineering is presented in this article. This technology is an integrated teaching method that significantly increases the practical component in the educational program. Author’s technology creates the conditions to overcome the shortcomings in the engineering education. The basic ideas of the technology of open-ended engineering, experience of their implementation in higher education and the author’s vision of the teaching technology are examined in the article. The main stages of development process of the author’s technology of open-ended engineering to prepare students (bachelor) of technical profile are presented in the article. Complex of the methodological tools and procedures is shown in the article. This complex is the basis of the developed training technology that is used in educational process in higher school of engineering (UrFU). The organizational model of the technology of open-ended engineering is presented. Organizational model integrates the functions in the creation and implementation of all educational program. Analysis of the characteristics of educational activity of students working on author’s technology of interdisciplinary open-ended engineering is presented. Intermediate results of the application of author’s technology in the educational process of the engineering undergraduate are shown.

  13. Semi-automated categorization of open-ended questions

    Directory of Open Access Journals (Sweden)

    Matthias Schonlau

    2016-08-01

    Full Text Available Text data from open-ended questions in surveys are difficult to analyze and are frequently ignored. Yet open-ended questions are important because they do not constrain respondents’ answer choices. Where open-ended questions are necessary, sometimes multiple human coders hand-code answers into one of several categories. At the same time, computer scientists have made impressive advances in text mining that may allow automation of such coding. Automated algorithms do not achieve an overall accuracy high enough to entirely replace humans. We categorize open-ended questions soliciting narrative responses using text mining for easy-to-categorize answers and humans for the remainder using expected accuracies to guide the choice of the threshold delineating between “easy” and “hard”. Employing multinomial boosting avoids the common practice of converting machine learning “confidence scores” into pseudo-probabilities. This approach is illustrated with examples from open-ended questions related to respondents’ advice to a patient in a hypothetical dilemma, a follow-up probe related to respondents’ perception of disclosure/privacy risk, and from a question on reasons for quitting smoking from a follow-up survey from the Ontario Smoker’s Helpline. Targeting 80% combined accuracy, we found that 54%-80% of the data could be categorized automatically in research surveys.

  14. Diagnosing Students’ conception on atomic structure using open ended questions

    Science.gov (United States)

    Fitriza, Z.; Gazali, F.

    2018-05-01

    This study aims to diagnose students’ conception on atomic structure concepts using open ended questions. For this reason, a 7 items of assay test was administered to 135 senior high school students from different schools in West Sumatera. The data were collected using a an open ended test which is covering the concept used in the topic Atomic Structure. The open ended test of students’ conceptual was developed to identify the alternative conceptions that student might have regarding the concepts in Atomic Structure, to measure the level of students’ conceptions, and the way of students’ thinking concerning the concepts. The results showed that students find difficulties about some concepts of Atomic structure such as atom, atomic model, electron configuration, period and group.The result of this study illuminated the concepts to be underlined in developing teaching and learning approach concerning the topic of Atomic Structure.

  15. Phase Radiation Characteristics of an Open-Ended Circular Waveguide

    DEFF Research Database (Denmark)

    Shishkova, A.V.; Pivnenko, Sergiy; Kim, O.S.

    2002-01-01

    Analytic expressions for phase radiation characteristics of a semi-infinite open-ended circular waveguide regardless of its aperture size and operating frequency have been obtained making use of the rigorous Weinstein's theory. The analysis of phase radiation patterns has been carried out...... for the dominant mode (TE11) as well as for the high order modes TM01 and TE01, both for a single and multimode propagation. The measurement of radiation characteristics of an open-ended circular waveguide has been carried out at the DTU-ESA Spherical Near-Field Antenna Test Facility. It is shown...

  16. Phase radiation characteristics of an open-ended circular waveguide

    DEFF Research Database (Denmark)

    Shishkova, Anna; Pivnenko, Sergey; Kim, Oleksiy S.

    2007-01-01

    General analytical expressions are derived for the far-field amplitude and phase radiation patterns of an open-ended circular waveguide (OE-CWG) regardless of its radius or the operation frequency for the dominant and symmetric higher-order excitation modes. The derivation is based on the rigorous...... solution to the problem of diffraction at an open end of a waveguide proposed by Weinstein. The near-field amplitude and phase patterns of an OE-CWG are then calculated using the spherical wave expansion technique. The measurement of the radiation pattern of an OE-CWG was carried out to verify the validity...

  17. Open-ended magnetic confinement systems for fusion

    International Nuclear Information System (INIS)

    Post, R.F.; Ryutov, D.D.

    1995-05-01

    Magnetic confinement systems that use externally generated magnetic fields can be divided topologically into two classes: ''closed'' and 'open''. The tokamak, the stellarator, and the reversed-field-pinch approaches are representatives of the first category, while mirror-based systems and their variants are of the second category. While the recent thrust of magnetic fusion research, with its emphasis on the tokamak, has been concentrated on closed geometry, there are significant reasons for the continued pursuit of research into open-ended systems. The paper discusses these reasons, reviews the history and the present status of open-ended systems, and suggests some future directions for the research

  18. PENGEMBANGAN BAHAN AJAR MATA KULIAH ALJABAR LINEAR BERBASIS OPEN ENDED

    Directory of Open Access Journals (Sweden)

    Nurul Farida

    2017-01-01

    Full Text Available Teaching materials is one important component in learning because teaching materials can be used for independent study. On the other hand, the lack of teaching materials are on open-ended problems leads to an underdevelopment of creativity in learning. With the open-ended problems, students are expected to have more than one solution to solve problems in everyday life, especially in mathematical problem solving. The purpose of this study is to develop teaching materials based on open-ended valildly, practically and effectively in the subject of linear algebra. This research is the development by using Plomp models which consists of three stages: preliminary research, prototyping, and assessment. Data collection technique through observation, questionnaires and tests. The instruments used were observation sheet, questionnaire sheet and a test sheet. Based on result of the research that has been done shows that the teaching materials is based on open-ended in the subject linear algebra that have been developed otherwise valid with a value of 3.43, practice with a value 3,11 or in the percentage reached 77,75%, and effective with value of learning outcomes experiment class (use teaching materials developed higher than control class.

  19. Two Open-Ended, Experiential Learning Cases in Accounting

    Science.gov (United States)

    Fuglister, Jayne; Stegmoyer, Matthew; Castrigano, Renee

    2010-01-01

    The rapidly changing environment in international business provides an excellent opportunity for instructors to design timely, adaptable, experiential learning, and open-ended cases. This paper presents and discusses how to prepare and use two such cases in the areas of bank accounting and international accounting. The cases can be offered and…

  20. Stimulating Mathematical Reasoning with Simple Open-Ended Tasks

    Science.gov (United States)

    West, John

    2018-01-01

    The importance of mathematical reasoning is unquestioned and providing opportunities for students to become involved in mathematical reasoning is paramount. The open-ended tasks presented incorporate mathematical content explored through the contexts of problem solving and reasoning. This article presents a number of simple tasks that may be…

  1. FDTD analysis of open-ended dielectric sensors

    Energy Technology Data Exchange (ETDEWEB)

    Anderson, J.; Okoniewski, M.; Stuchly, S.S. [Univ. of Victoria (Canada)

    1994-12-31

    The reflection coefficient of an open-ended coaxial line immersed in water and methanol is simulated using a modified FDTD code. Calculated values are compared with previously obtained moment method and experimental values. The effects of variations in the end of line geometry on the reflection coefficient are investigated.

  2. Performance Evaluation of Open-Ended ELSS Mutual Fund ...

    African Journals Online (AJOL)

    This study examined the performance of the open-ended equity linked saving mutual fund schemes (ELSS) in India during the financial distress in 2008-2009. In this study, the month end net asset values of selected equity linked saving mutual fund schemes were considered and the data was obtained from the website of ...

  3. Course Evaluation Systems for Open-ended Quality Enhancement

    DEFF Research Database (Denmark)

    Piihl, Jesper; Rasmussen, Jens Smed

    2013-01-01

    Quality in higher education is widely controlled through surveys asking students to evaluate teaching. However, control of quality does not necessarily lead to enhancement of quality. Drawing on accounting research and a case study, a measurement-based and open-ended quality control system...... emphasising quality enhancement is suggested. The case shows how interactive use of performance measurement can lead to more engaged and enabling dialogue amongst involved actors concerning quality enhancement, however institutionalised beliefs regarding course evaluation systems makes a change challenging....... The chapter suggests that open-ended measurement systems enabling stakeholders to take responsibility for quality enhancement is not so much a matter of technical design as a matter of an enabling style of use....

  4. Open-ended guidewire for percutaneous therapy of varicocele

    International Nuclear Information System (INIS)

    Benea, G.; Galeotti, R.; Tartari, S.; Mannella, P.

    1989-01-01

    Percutaneous transvenous treatment has become the elective therapy for varicocele because it is a simple, safe, economic and reliable procedure. The presence of proximal anastomoses connecting a competent valved spermatic trunk with the renal vein can be responsible for a varicocele and make its treatment difficult. In such cases, the valve of the spermatic venous trunk can be bypassed using an open-ended guidewire with a removable mandril core, and then injecting the sclerosing agent through the guide. Moreover, the guidewire can facilitate the insertion of catheter through the competent valve, thus allowing the placement of Gianturco coils. During the past 12 months the authors have successfully treated 4 patients affected by varicocele with competent valved venous trunk using the open-ended guidewire

  5. A Computational Analysis Model for Open-ended Cognitions

    Science.gov (United States)

    Morita, Junya; Miwa, Kazuhisa

    In this paper, we propose a novel usage for computational cognitive models. In cognitive science, computational models have played a critical role of theories for human cognitions. Many computational models have simulated results of controlled psychological experiments successfully. However, there have been only a few attempts to apply the models to complex realistic phenomena. We call such a situation ``open-ended situation''. In this study, MAC/FAC (``many are called, but few are chosen''), proposed by [Forbus 95], that models two stages of analogical reasoning was applied to our open-ended psychological experiment. In our experiment, subjects were presented a cue story, and retrieved cases that had been learned in their everyday life. Following this, they rated inferential soundness (goodness as analogy) of each retrieved case. For each retrieved case, we computed two kinds of similarity scores (content vectors/structural evaluation scores) using the algorithms of the MAC/FAC. As a result, the computed content vectors explained the overall retrieval of cases well, whereas the structural evaluation scores had a strong relation to the rated scores. These results support the MAC/FAC's theoretical assumption - different similarities are involved on the two stages of analogical reasoning. Our study is an attempt to use a computational model as an analysis device for open-ended human cognitions.

  6. Open-Ended Behavioral Complexity for Evolved Virtual Creatures

    DEFF Research Database (Denmark)

    Lessin, Dan; Fussell, Don; Miikkulainen, Risto

    2013-01-01

    notable exception to this progress. Despite the potential benefits, there has been no clear increase in the behavioral complexity of evolved virtual creatures (EVCs) beyond the light following demonstrated in Sims' original work. This paper presents an open-ended method to move beyond this limit, making...... creature with behavioral complexity that clearly exceeds previously achieved levels. ESP thus demonstrates that EVCs may indeed have the potential to one day rival the behavioral complexity--and therefore the entertainment value--of their non-virtual counterparts....

  7. Open-ended response theory with polarizable embedding

    DEFF Research Database (Denmark)

    Steindal, Arnfinn Hykkerud; Beerepoot, Maarten T P; Ringholm, Magnus

    2016-01-01

    We present the theory and implementation of an open-ended framework for electric response properties at the level of Hartree-Fock and Kohn-Sham density functional theory that includes effects from the molecular environment modeled by the polarizable embedding (PE) model. With this new state......-of-the-art multiscale functionality, electric response properties to any order can be calculated for molecules embedded in polarizable atomistic molecular environments ranging from solvents to complex heterogeneous macromolecules such as proteins. In addition, environmental effects on multiphoton absorption (MPA...

  8. Vortex formation at the open end of an acoustic waveguide

    Science.gov (United States)

    Martinez Del Rio, Leon; Rendon, Pablo L.; Malaga, Carlos; Zenit, Roberto

    2017-11-01

    For high enough levels of acoustic pressure inside a cylindrical tube, a nonlinear mechanism is responsible for the formation of annular vortices at the open end of the tube, which results in energy loss. Higher sound pressure levels in the tube lead, in turn, to larger values of the acoustic velocity at the exit, and thus to higher Reynolds numbers. It has been observed [Buick et al., 2011] that, provided the magnitude of the acoustic velocity is large enough, two nonlinear regimes are possible: in the first regime, the vorticity appears only in the immediate vicinity of the tube; for higher velocities, vortex rings are formed at the open end of the tube and are advected outwards. We use a Lattice Boltzmann Method (LBM) to simulate the velocity and the pressure fields at the exit of the tube in 3D, with Reynolds numbers based on the acoustic boundary layer thickness 18 >Rδ > 1.8 . We also conduct experiments with phase-locked particle image velocimetry (PL-PIV) 2D within a range of 25.5 >Rδ > 10.2 . Experimental and numerical results are compared for a range of Womersley numbers. The effects of varying both the tube geometry and the end shape are addressed.

  9. Discontinuous phase transition in an open-ended Naming Game

    International Nuclear Information System (INIS)

    Crokidakis, Nuno; Brigatti, Edgardo

    2015-01-01

    In this work we study on a 2D square lattice a recent version of the Naming Game, an agent-based model used for describing the emergence of linguistic structures. The system is open-ended and agents can invent new words throughout the evolution of the game, picking them up from a pool characterised by a Gaussian distribution with standard deviation σ. The model displays a nonequilibrium phase transition at a critical point σ c  ≈ 25.6, which separates an absorbing consensus state from an active fragmented state where agents continuously exchange different words. The finite-size scaling analysis of our simulations strongly suggests that the phase transition is discontinuous. (paper)

  10. An Open-Ended Approach to Evaluating Android Faces

    DEFF Research Database (Denmark)

    Vlachos, Evgenios; Schärfe, Henrik

    2015-01-01

    relevant to the portrayed facial expressions for the emotions of Surprise, Fear, Anger, and Happiness, and less relevant for the emotions of Disgust, and Sadness. Statistical analysis indicated the existence of a moderate degree of correlation between the emotions of Fear-Surprise, and a high degree...... of correlation between the pair Disgust-Sadness. With a set of validated facial expressions prior to nonverbal emotional communication, androids and other humanoids can convey more accurate messages to their interaction partners, and overcome the limitations of their current limited affective interface.......Expectation and intention understanding through nonverbal behavior is a key topic of interest in socially embedded robots. This study presents the results of an open-ended evaluation method pertaining to the interpretation of Android facial expressions by adult subjects through an online survey...

  11. MAXIMUM AIR SUCTION INTO HORIZONTAL OPEN ENDED CYLINDRICAL LOUVERED PIPE

    Directory of Open Access Journals (Sweden)

    SAMEER RANJAN SAHU

    2017-02-01

    Full Text Available The main approach behind the present numerical investigation is to estimate the mass flow rate of air sucked into a horizontal open-ended louvered pipe from the surrounding atmosphere. The present numerical investigation has been performed by solving the conservation equations for mass, momentum and energy along with two equation based k-ɛ model for a louvered horizontal cylindrical pipe by finite volume method. It has been found from the numerical investigation that mass suction rate of air into the pipe increases with increase in louvered opening area and the number of nozzles used. Keeping other parameters fixed, for a given mass flow rate there exists an optimum protrusion of nozzle for highest mass suction into the pipe. It was also found from the numerical investigation that increasing the pipe diameter the suction mass flow rate of air was increased.

  12. Microwave corrosion detection using open ended rectangular waveguide sensors

    Energy Technology Data Exchange (ETDEWEB)

    Qaddoumi, N.; Handjojo, L.; Bigelow, T.; Easter, J.; Bray, A.; Zoughi, R.

    2000-02-01

    The use of microwave and millimeter wave nondestructive testing methods utilizing open ended rectangular waveguide sensors has shown great potential for detecting minute thickness variations in laminate structures, in particular those backed by a conducting plate. Slight variations in the dielectric properties of materials may also be detected using a set of optimal parameters which include the standoff distance and the frequency of operation. In a recent investigation, on detecting rust under paint, the dielectric properties of rust were assumed to be similar to those of Fe{sub 2}O{sub 3} powder. These values were used in an electromagnetic model that simulates the interaction of fields radiated by a rectangular waveguide aperture with layered structures to obtain optimal parameters. The dielectric properties of Fe{sub 2}O{sub 3} were measured to be very similar to the properties of paint. Nevertheless, the presence of a simulated Fe{sub 2}O{sub 3} layer under a paint layer was detected. In this paper the dielectric properties of several different rust samples from different environments are measured. The measurements indicate that the nature of real rust is quite diverse and is different from Fe{sub 2}O{sub 3} and paint, indicating that the presence of rust under paint can be easily detected. The same electromagnetic model is also used (with the newly measured dielectric properties of real rust) to obtain an optimal standoff distance at a frequency of 24 GHz. The results indicate that variations in the magnitude as well as the phase of the reflection coefficient can be used to obtain information about the presence of rust. An experimental investigation on detecting the presence of very thin rust layers (2.5--5 x 10{sup {minus}2} mm [09--2.0 x 10{sup {minus}3} in.]) using an open ended rectangular waveguide probe is also conducted. Microwave images of rusted specimens, obtained at 24 GHz, are also presented.

  13. Nanoscopic Electrofocusing for Bio-Nanoelectronic Devices

    Science.gov (United States)

    Lakshmanan, Shanmugamurthy

    2015-01-01

    The ability to arrange precisely designed patterns of nanoparticles into a desired spatial configuration is the key to creating novel nanoscale devices that take advantage of the unique properties of nanomaterials. While two-dimensional arrays of nanoparticles have been demonstrated successfully by various techniques, a controlled way of building ordered arrays of three-dimensional (3D) nanoparticle structures remains challenging. This book describes a new technique called the 'nanoscopic lens' which is able to produce a variety of 3D nano-structures in a controlled manner. This ebook describes the nanoscopic lens technique and how it can serve as the foundation for device development that is not limited to a variety of optical, magnetic and electronic devices, but can also create a wide range of bio-nanoelectronic devices.

  14. 24 CFR 203.256 - Insurance of open-end advance.

    Science.gov (United States)

    2010-04-01

    ... Insurance § 203.256 Insurance of open-end advance. Insurance on an open-end advance will be evidenced by delivery of a certificate stating the amount of the advance, the date of insurance, and the regulations... 24 Housing and Urban Development 2 2010-04-01 2010-04-01 false Insurance of open-end advance. 203...

  15. Nanoscopic Manipulation and Imaging of Liquid Crystals

    Energy Technology Data Exchange (ETDEWEB)

    Rosenblatt, Charles S. [Case Western Reserve Univ., Cleveland, OH (United States)

    2014-02-04

    This is the final project report. The project’s goals centered on nanoscopic imaging and control of liquid crystals and surfaces. We developed and refined techniques to control liquid crystal orientation at surfaces with resolution as small as 25 nm, we developed an optical imaging technique that we call Optical Nanotomography that allows us to obtain images inside liquid crystal films with resolution of 60 x 60 x 1 nm, and we opened new thrust areas related to chirality and to liquid crystal/colloid composites.

  16. Vegetation dielectric characterization using an open-ended coaxial probe

    Science.gov (United States)

    Mavrovic, A.; Roy, A.; Royer, A.; Boone, F.; Pappas, C.; Filali, B.

    2017-12-01

    The detection of freeze/thaw (F/T) physical state of soil is one of the main objectives of the SMAP mission as well as one of the secondary objectives of the SMOS mission. Annual F/T cycles have substantial impacts on surface energy budgets, permafrost conditions, as well as forest water and carbon dynamics. It has been shown that spaceborne L-band passive radiometry is a promising tool to monitor F/T due to the substantial differences between the permittivity of water and ice at these frequencies. However, the decoupling of the signal between soil and vegetation components remains challenging for all microwave remote sensing applications at various spatial scales. Radiative transfer models in the microwave domain are generally poorly parameterized to consider the non-negligible contribution of vegetation. The main objective of this research is to assess the skill of a recently developed Open-Ended Coaxial Probe (OECP) to measure the complex microwave permittivity of vegetation and soils and to derive a relation between the impact of vegetation on the microwave signal and the vegetation permittivity that could serve as a validation tool for soil models especially in frozen state. Results show that the OECP is a suitable tool to infer the radial profile of the complex permittivity in L-band of trees. A clear distinction can be made between the dielectric characterization of the sapwood where the permittivity is high because of the high permittivity of water but decrease with depth, and the heartwood where the permittivity is low and relatively constant. The seasonal cycle of the F/T state of the vegetation can also be observed since it is strongly correlated with the permittivity of the wood. The permittivity of a tree over the winter season is very low and homogenous since the permittivity of ice is significantly lower than water and the sap flow is negligible. The fluctuation of the frozen and thawed permittivity for different tree species was evaluated, focusing

  17. Functional polymers as nanoscopic building blocks

    International Nuclear Information System (INIS)

    Hernandez-Lopez, J.L.; Bauer, R.E.; Chang, W.-S.; Glasser, G.; Grebel-Koehler, D.; Klapper, M.; Kreiter, M.; Leclaire, J.; Majoral, J.-P.; Mittler, S.; Muellen, K.; Vasilev, K.; Weil, T.; Wu, J.; Zhu, T.; Knoll, W.

    2003-01-01

    Polyphenylene dendrimers are introduced as polymeric building blocks--with a strictly monodisperse particle size distribution within the nanometer range--for the construction of nanostructured materials and devices. The possibility for the introduction of different functionalities in the core, the scaffold or the periphery of the dendrimers offer their use as interesting modules for photonic, electronic or bioactive structures and supramolecular functional assemblies. Thus, dendrimers complement the available set of nanoscopic building blocks made from metals, e.g., Au nanoclusters and semiconductors, e.g., luminescent quantum dots. In a first set of experiments, we describe the fabrication of multilayer architectures using dendrimers with chargeable groups at the surface. This way, the polyelectrolyte deposition technique can be applied for the construction of hybrid layered assemblies with a control of the internal supramolecular structure at the nanometer level. Surface plasmon field-enhanced fluorescence spectroscopy is used to monitor the luminescent properties of dendrimers with a phthalocyanine core integrated into such a multilayer assembly. AFM and SEM micrographs demonstrate the use of surface-functionalized dendrimers (exposing sulfur groups at the periphery) in combination with Au nanoparticles for the controlled assembly of hybrid aggregates as nanoscopic functional devices

  18. Visualizing Nanoscopic Topography and Patterns in Freely Standing Thin Films

    Science.gov (United States)

    Yilixiati, Subinuer; Zhang, Yiran; Pearsall, Collin; Sharma, Vivek

    Thin liquid films containing micelles, nanoparticles, polyelectrolyte-surfactant complexes and smectic liquid crystals undergo thinning in a discontinuous, step-wise fashion. The discontinuous jumps in thickness are often characterized by quantifying changes in the intensity of reflected monochromatic light, modulated by thin film interference from a region of interest. Stratifying thin films exhibit a mosaic pattern in reflected white light microscopy, attributed to the coexistence of domains with various thicknesses, separated by steps. Using Interferometry Digital Imaging Optical Microscopy (IDIOM) protocols developed in the course of this study, we spatially resolve for the first time, the landscape of stratifying freestanding thin films. In particular, for thin films containing micelles of sodium dodecyl sulfate (SDS), discontinuous, thickness transitions with concentration-dependent steps of 5-25 nm are visualized and analyzed using IDIOM protocols. We distinguish nanoscopic rims, mesas and craters and show that the non-flat features are sculpted by oscillatory, periodic, supramolecular structural forces that arise in confined fluids

  19. Product differentiation among health maintenance organizations: causes and consequences of offering open-ended products.

    Science.gov (United States)

    Wholey, D R; Christianson, J B

    1994-01-01

    Open-ended products that allow an HMO enrollee to use providers who are not affiliated with the HMO have become an important component of the Clinton administration's health reform proposal, because these products maintain consumer freedom of choice of any provider. However, little is known about the consequences of offering an open-ended product from an organizational standpoint. This paper uses a theory of "spatial competition" to examine the decisions of health maintenance organizations to offer an open-ended product and the effect of offering an open-ended product on their enrollment.

  20. 78 FR 79298 - Securities Exempted; Distribution of Shares by Registered Open-End Management Investment Company...

    Science.gov (United States)

    2013-12-30

    ...] Securities Exempted; Distribution of Shares by Registered Open- End Management Investment Company...) 551-6792, Investment Company Rulemaking Office, Division of Investment Management, U.S. Securities and... Distribution of shares by registered open-end management investment company. * * * * * (g) If a plan covers...

  1. Leaving room for improvisation: towards a design approach for open-ended play.

    NARCIS (Netherlands)

    Valk, de L.C.T.; Bekker, M.M.; Eggen, J.H.

    2013-01-01

    Open-ended play with interactive objects provides children with the freedom to construct their own rules, goals and meaning. Instead of games with strict rules, open-ended play designs offer interaction opportunities as a trigger for creating personalized games. The process of developing these

  2. 12 CFR 221.109 - Loan to open-end investment company.

    Science.gov (United States)

    2010-01-01

    ... CARRYING MARGIN STOCK (REGULATION U) Interpretations § 221.109 Loan to open-end investment company. In... customarily purchases stocks registered on a national securities exchange, the Board stated that in view of... 12 Banks and Banking 3 2010-01-01 2010-01-01 false Loan to open-end investment company. 221.109...

  3. Optimized Integrated Harmonic Filter Inductor for Dual-Converter-Fed Open-End Transformer Topology

    DEFF Research Database (Denmark)

    Gohil, Ghanshyamsinh Vijaysinh; Bede, Lorand; Teodorescu, Remus

    2017-01-01

    Many high power converter systems are often connected to the medium voltage network using a step-up transformer. In such systems, the converter-side windings of the transformer can be configured as an open-end and multi-level voltage waveforms can be achieved by feeding these open-end windings from...

  4. Radiation pattern of open ended waveguide in air core surrounded by annular plasma column

    International Nuclear Information System (INIS)

    Sharma, D.R.; Verma, J.S.

    1977-01-01

    Radiation pattern of open ended waveguide excited in circular symmetric mode (TM 01 ) in an air core having central conductor and surrounded by an annular plasma column is studied. The field distribution at the open end of the waveguide is considered to be equivalent to the vector sum of magnetic current rings of various radii, ranging from the outer radius of the inner conductor to the inner radius of the outer conductor of the waveguide at the open end. The radiation field is obtained as a vector sum of field components due to individual rings of current. Such a configuration gives rise to multiple narrow radiation beams away from the critical angle. (author)

  5. Ambiguity Towards Multiple Historical Performance Information Signals: Evidence From Indonesian Open-Ended Mutual Fund Investors

    OpenAIRE

    Haris Pratama Loeis; Ruslan Prijadi

    2015-01-01

    This study focuses on the behavior of open-ended mutual fund investors when encountered with multiple information signals of mutual fund’s historical performance. The behavior of investors can be reflected on their decision to subscribe or redeem their funds from mutual funds. Moreover, we observe the presence of ambiguity within investors due to multiple information signals, and also their reaction towards it. Our finding shows that open-ended mutual fund investors do not only have sen...

  6. Percutaneous sclerotherapy of the internal spermatic vein for varicocele through an open ended guide wire

    Energy Technology Data Exchange (ETDEWEB)

    Wilms, G.; Oyen, R.; Casselman, J.; Baert, A.L.

    1987-08-01

    Percutaneous sclerotherapy of the internal spermatic vein through an open ended guide wire was performed in 50 patients with left sided variocele. The procedure was successful in 47 patients, without major complications. Percutaneous sclerotherapy through an open ended guide wire offers the advantage of very distal and superselective catheterization with complete embolization of the internal spermatic vein, its side branches and parallel collateral channels. Further follow-up hopefully will confirm the reduction of recurrence rate in our patients.

  7. Models for randomly distributed nanoscopic domains on spherical vesicles

    Science.gov (United States)

    Anghel, Vinicius N. P.; Bolmatov, Dima; Katsaras, John

    2018-06-01

    The existence of lipid domains in the plasma membrane of biological systems has proven controversial, primarily due to their nanoscopic size—a length scale difficult to interrogate with most commonly used experimental techniques. Scattering techniques have recently proven capable of studying nanoscopic lipid domains populating spherical vesicles. However, the development of analytical methods able of predicting and analyzing domain pair correlations from such experiments has not kept pace. Here, we developed models for the random distribution of monodisperse, circular nanoscopic domains averaged on the surface of a spherical vesicle. Specifically, the models take into account (i) intradomain correlations corresponding to form factors and interdomain correlations corresponding to pair distribution functions, and (ii) the analytical computation of interdomain correlations for cases of two and three domains on a spherical vesicle. In the case of more than three domains, these correlations are treated either by Monte Carlo simulations or by spherical analogs of the Ornstein-Zernike and Percus-Yevick (PY) equations. Importantly, the spherical analog of the PY equation works best in the case of nanoscopic size domains, a length scale that is mostly inaccessible by experimental approaches such as, for example, fluorescent techniques and optical microscopies. The analytical form factors and structure factors of nanoscopic domains populating a spherical vesicle provide a new and important framework for the quantitative analysis of experimental data from commonly studied phase-separated vesicles used in a wide range of biophysical studies.

  8. EFEKTIVITAS OPEN-ENDED EXPERIENTIAL LEARNING CASES DALAM PENINGKATAN PERTIMBANGAN PROFESIONAL

    Directory of Open Access Journals (Sweden)

    Andian Ari Istiningrum

    2015-04-01

    Full Text Available Abstrak: Penelitian ini bertujuan untuk mengetahui efektivitas implementasi model pembelajaran Open-Ended Experiential Learning Cases dalam usaha peningkatan kemampuan mahasiswa untuk memberikan pertimbangan profesional. Penelitian ini merupakan penelitian pre-experimental design dengan jenis one-group pretes-postes design. Popolasi penelitian adalah mahasiswa jurusan Akuntansi yang mengambil mata kuliah Akuntansi Keuangan Menengah 1 sebanyak 75 orang, sedangkan sampel yang digunakan adalah 44 orang. Teknik pengambilan sampel dilakukan dengan convenience sampling. Data dikumpulkan dengan tes uraian dan dianalisis dengan uji beda t test untuk sampel berhubungan. Hasil penelitian menunjukkan bahwa terdapat perbedaan signifikan kemampuan mahasiswa dalam memberikan pertimbangan profesional sebelum dan sesudah model pembelajaran open-ended experiential learning cases diimplementasikan yang menunjukkan terjadinya peningkatan pertimbangan profesional setelah mahasiswa mengikuti pembelajaran dengan model pembelajaran openended experiential learning cases. Kata Kunci: open-ended experiential learning cases, pertimbangan profesional THE EFFECTIVENESS OF OPEN-ENDED EXPERIENTIAL LEARNING CASES TO IMPROVE PROFESSIONAL JUDGMENT Abstract: This study was aimed to reveal the effectiveness of the implementation of the open-ended experiential learning cases to improve students’ professional judgment. To achieve this purpose, the study was designed as the pre-experimental design with the one-group pretest-post-test design type. The population of the study was the Accounting Department Students at Yogyakarta State University taking the 1 st Intermediate Financial Accounting course. There were 75 students as the population and 44 students were chosen as the research sample. The sampling technique used was the convenience sampling. The data were collected by using the essay test and analyzed by t-test for paired samples. The findings showed that there was a

  9. 17 CFR 270.12b-1 - Distribution of shares by registered open-end management investment company.

    Science.gov (United States)

    2010-04-01

    ... registered open-end management investment company. 270.12b-1 Section 270.12b-1 Commodity and Securities... 1940 § 270.12b-1 Distribution of shares by registered open-end management investment company. (a)(1... the printing and mailing of sales literature; (b) A registered, open-end management investment company...

  10. 17 CFR 274.11A - Form N-1A, registration statement of open-end management investment companies.

    Science.gov (United States)

    2010-04-01

    ... statement of open-end management investment companies. 274.11A Section 274.11A Commodity and Securities...(b) of the Investment Company Act of 1940 by open-end management investment companies other than... registration under the Securities Act of 1933 of the securities of all open-end management investment companies...

  11. Clad vent set cup open end (closure weld zone) wall-thickness study

    Energy Technology Data Exchange (ETDEWEB)

    Ulrich, G.B.; Sherrill, M.W.

    1994-09-01

    The wall thickness at the open end of Clad Vent Set (CVS) cups is a very important parameter for maintaining control of the fueled CVS closure weld process. Ideally, the wall thickness in the closure weld zone should be constant. The DOP-26 iridium alloy is very difficult to machine; therefore, key dimensional features are established during the two-draw warm-forming operation. Unfortunately, anisotropy in the forming blanks produces four ears at the open end of each cup. Formation of these ears produces axial and circumferential variations in wall thickness. The cup certification requirement is that the wall thickness in the closure weld zone, defined as the 2.5-mm band at the open end of a cup, measure from 0.63 to 0.73 mm. The wall thickness certification data for the open end of the CVS cups have been statistically evaluated. These data show that the cups recently produced for the Cassini mission have well-controlled open-end wall thicknesses.

  12. PENGEMBANGAN MODUL DENGAN PENDEKATAN OPEN ENDED UNTUK MEMFASILITASI PENCAPAIAN LITERASI MATEMATIS

    Directory of Open Access Journals (Sweden)

    Agung Putra Wijaya

    2017-12-01

    Full Text Available This research and development aimed to develop module with an open ended approach to facilitate the achievement of mathematical literacy. This study was conducted only until the  field trial and the revision of product. The module was validated by experts with attention to aspects: matter, appearance, and practicality. Having been declared valid by experts, the test readability by the students was done. Based on the steps, it was obtained (1 the use of the module with an open ended approach in Linier Programmingwas expected by the students, (2 the module characteristics were in accordance with the curriculum and designed in accordance with the open-ended approach, (3 the experts responses to the module were appropriate in terms of aspects of matter, appearance, and practicality and (4 the students responses were good viewed by readability.

  13. Optimizing Open-Ended Crowdsourcing: The Next Frontier in Crowdsourced Data Management

    Science.gov (United States)

    Parameswaran, Aditya; Sarma, Akash Das; Venkataraman, Vipul

    2017-01-01

    Crowdsourcing is the primary means to generate training data at scale, and when combined with sophisticated machine learning algorithms, crowdsourcing is an enabler for a variety of emergent automated applications impacting all spheres of our lives. This paper surveys the emerging field of formally reasoning about and optimizing open-ended crowdsourcing, a popular and crucially important, but severely understudied class of crowdsourcing—the next frontier in crowdsourced data management. The underlying challenges include distilling the right answer when none of the workers agree with each other, teasing apart the various perspectives adopted by workers when answering tasks, and effectively selecting between the many open-ended operators appropriate for a problem. We describe the approaches that we’ve found to be effective for open-ended crowdsourcing, drawing from our experiences in this space. PMID:28951893

  14. Designing students’ worksheet based on open-ended approach to foster students’ creative thinking skills

    Science.gov (United States)

    Romli, S.; Abdurrahman; Riyadi, B.

    2018-01-01

    This study aimed at designing an open-ended worksheet to enhance students’ creative thinking skills. The study was conducted at one private school in Bandar Lampung, Indonesia. The participants of the study were twenty students of tenth grade students and two physics teachers. This study used descriptive data. Data were collected by analyzing qualitative data, literature and focus group discussion to gain information about students’ conceptions of physics in the context of open-ended learning. The result showed that students needed innovative learning resources in form of open ended-based worksheet which could give the students an opportunity to develop various solutions related to physics problem. Therefore, students’ creative thinking skill could be improved.

  15. MENINGKATKAN KEMAMPUAN BERPIKIR KREATIF MATEMATIS SISWA SMA MELALUI PEMBELAJARAN OPEN ENDED PADA MATERI SPLDV

    Directory of Open Access Journals (Sweden)

    Firdaus Firdaus

    2016-02-01

    Penelitian ini bertujuan untuk mendeskripsikan kemampuan berpikir kreatif matematis siswa SMA melalui pembelajaran open ended problem materi SPLDV. Jenis penelitian ini, yaitu deskriptif kualitatif. Subjeknya adalah siswa kelas X.2 SMA Negeri 1 Woja Dompu. Tahap pembelajaran dalam penelitian ini adalah (1 Orientasi, (2 pembekalan materi, (3 penyajian dan pengerjaan soal open ended, (4 presentasi, (5 kesimpulan. Kemampuan berpikir kreatif matematis siswa meliputi: (a fluency, kemampuan siswa lancar dalam memberikan jawaban benar, (b flexibility, kemampuan siswa dalam menggunakan berbagai cara penyelesaian masalah, (c novelty, kemampuan siswa dalam memberikan jawaban yang baru dan berbeda dengan siswa lain. Penelitian ini hasilnya, bahwa siswa mempunyai kemampuan berpikir kreatif matematis.

  16. Fabrication of nickel hydroxide electrodes with open-ended hexagonal nanotube arrays for high capacitance supercapacitors.

    Science.gov (United States)

    Wu, Mao-Sung; Huang, Kuo-Chih

    2011-11-28

    A nickel hydroxide electrode with open-ended hexagonal nanotube arrays, prepared by hydrolysis of nickel chloride in the presence of hexagonal ZnO nanorods, shows a very high capacitance of 1328 F g(-1) at a discharge current density of 1 A g(-1) due to the significantly improved ion transport.

  17. Designing EEG Neurofeedback Procedures to Enhance Open-Ended versus Closed-Ended Creative Potentials

    Science.gov (United States)

    Lin, Wei-Lun; Shih, Yi-Ling

    2016-01-01

    Recent empirical evidence demonstrated that open-ended creativity (which refers to creativity measures that require various and numerous responses, such as divergent thinking) correlated with alpha brain wave activation, whereas closed-ended creativity (which refers to creativity measures that ask for one final correct answer, such as insight…

  18. Developing Open-Ended Questions for Surface Area and Volume of Beam

    Science.gov (United States)

    Kurniawan, Henry; Putri, Ratu Ilma Indra; Hartono, Yusuf

    2018-01-01

    The purpose of this research was to show open-ended questions about surface area and beam volume which valid and practice, have potential effect. This research is research development which consists of two main phases: preliminary phase (preparation phase and problem design) and formative evaluation phase (evaluation and revision phases). The…

  19. 17 CFR 230.498 - Summary Prospectuses for open-end management investment companies.

    Science.gov (United States)

    2010-04-01

    ...-end management investment companies. 230.498 Section 230.498 Commodity and Securities Exchanges... management investment companies. (a) Definitions. For purposes of this section: (1) Class means a class of... reliance on an exemptive rule adopted by the Commission. (3) Fund means an open-end management investment...

  20. Students’ Spatial Ability through Open-Ended Approach Aided by Cabri 3D

    Science.gov (United States)

    Priatna, N.

    2017-09-01

    The use of computer software such as Cabri 3D for learning activities is very unlimited. Students can adjust their learning speed according to their level of ability. Open-ended approach strongly supports the use of computer software in learning, because the goal of open-ended learning is to help developing creative activities and mathematical mindset of students through problem solving simultaneously. In other words, creative activities and mathematical mindset of students should be developed as much as possible in accordance with the ability of spatial ability of each student. Spatial ability is the ability of students in constructing and representing geometry models. This study aims to determine the improvement of spatial ability of junior high school students who obtained learning with open-ended approach aided by Cabri 3D. It adopted a quasi-experimental method with the non-randomized control group pretest-posttest design and the 2×3 factorial model. The instrument of the study is spatial ability test. Based on analysis of the data, it is found that the improvement of spatial ability of students who received open-ended learning aided by Cabri 3D was greater than students who received expository learning, both as a whole and based on the categories of students’ initial mathematical ability.

  1. The Effect of Contextualized Conversational Feedback in a Complex Open-Ended Learning Environment

    Science.gov (United States)

    Segedy, James R.; Kinnebrew, John S.; Biswas, Gautam

    2013-01-01

    Betty's Brain is an open-ended learning environment in which students learn about science topics by teaching a virtual agent named Betty through the construction of a visual causal map that represents the relevant science phenomena. The task is complex, and success requires the use of metacognitive strategies that support knowledge acquisition,…

  2. Centrifuge modeling of rapid load tests with open-ended piles

    NARCIS (Netherlands)

    Nguyen, T.C.; Van Lottum, H.; Holscher, P.; Van Tol, A.F.

    2012-01-01

    Rapid and static load tests were conducted on open-ended and close-ended piles in the Deltares GeoCentriflige. hi flight, a pile was driven into the soil. Both fme-grained sand and silt beds were tested. Both the rapid and static soil resistances o f a close-ended pile were higher than the soil

  3. Large Scale Metric Learning for Distance-Based Image Classification on Open Ended Data Sets

    NARCIS (Netherlands)

    Mensink, T.; Verbeek, J.; Perronnin, F.; Csurka, G.; Farinella, G.M.; Battiato, S.; Cipolla, R,

    2013-01-01

    Many real-life large-scale datasets are open-ended and dynamic: new images are continuously added to existing classes, new classes appear over time, and the semantics of existing classes might evolve too. Therefore, we study large-scale image classification methods that can incorporate new classes

  4. Text mining in students' course evaluations: Relationships between open-ended comments and quantitative scores

    DEFF Research Database (Denmark)

    Sliusarenko, Tamara; Clemmensen, Line Katrine Harder; Ersbøll, Bjarne Kjær

    2013-01-01

    Extensive research has been done on student evaluations of teachers and courses based on quantitative data from evaluation questionnaires, but little research has examined students' written responses to open-ended questions and their relationships with quantitative scores. This paper analyzes suc...

  5. Designing to bring the field to the showroom through open-ended provocation.

    NARCIS (Netherlands)

    Kelly, J.; Wensveen, S.A.G.

    2014-01-01

    Engaging formats are required to communicate designerly understandings of field studies to a broader audience within organisations. Here we present a case where the format of an exhibition, consisting of a collection of open-ended provocative design concepts, has been used to disseminate knowledge

  6. Expressivity in Open-ended Constructive Play: Building and Playing Musical Lego Instruments

    DEFF Research Database (Denmark)

    Jakobsen, Kasper; Stougaard, Jeppe; Petersen, Marianne Graves

    2016-01-01

    This paper presents the findings from a case study in designing for open-ended constructive play for children. The study is based on a workshop where more that 150 children in ages 3-13 built and played their own musical instruments from Lego. The children used different sensors for playing...

  7. Downtown Study Centre: An Open-Ended ABE Program in an Urban Shopping Mall

    Science.gov (United States)

    Harrison, David

    1976-01-01

    Describes an adult basic education facility after one year of operation in an urban shopping mall in Nanaimo, British Columbia, Canada. The center is an informal open-ended classroom and advising center where part-time adult learners study an individualized curriculum. Summarizes the major findings of a program evaluation. (EM)

  8. Text analysis of open-ended survey responses : a complementary method to preference mapping

    NARCIS (Netherlands)

    ten Kleij, F; Musters, PAD

    The present study illustrates the use of computer-aided text analysis to evaluate the content of open-ended survey responses. During an in-hall test, different varieties of mayonnaise were evaluated by 165 respondents on a 10-point liking scale, with the option to freely comment on these

  9. Transparency in Transcribing: Making Visible Theoretical Bases Impacting Knowledge Construction from Open-Ended Interview Records

    Directory of Open Access Journals (Sweden)

    Audra Skukauskaite

    2012-01-01

    Full Text Available This article presents a reflexive analysis of two transcripts of an open-ended interview and argues for transparency in transcribing processes and outcomes. By analyzing ways in which a researcher's theories become consequential in producing and using transcripts of an open-ended interview, this paper makes visible the importance of examining and presenting theoretical bases of transcribing decisions. While scholars across disciplines have argued that transcribing is a theoretically laden process (GREEN, FRANQUIZ & DIXON, 1997; KVALE & BRINKMAN, 2009, few have engaged in reflexive analyses of the data history to demonstrate the consequences particular theoretical and methodological approaches pose in producing knowledge claims and inciting dialogues across traditions. The article demonstrates how theory-method-claim relationships in transcribing influence research transparency and warrantability. URN: http://nbn-resolving.de/urn:nbn:de:0114-fqs1201146

  10. The Solving of Problems in Chemistry: the more open-ended problems

    Science.gov (United States)

    Reid, Norman; Yang, Mei-Jung

    2002-01-01

    Most problem solving in chemistry tends to be algorithmic in nature, while problems in life tend to be very open ended. This paper offers a simple classification of problems and seeks to explore the many factors which may be important in the successful solving of problems. It considers the place of procedures and algorithms. It analyses the role of long-term memory, not only in terms of what is known, but how that knowledge was acquired. It notes the great importance of the limitations of working memory space and the importance of confidence which comes from experience. Finally, various psychological factors are discussed. This paper argues that solving open-ended problems is extremely important in education and that offering learners experience of this in a group work context is a helpful way forward.

  11. A qualitative analysis of kindergarteners’ open-ended drawing and story telling opportunities

    Directory of Open Access Journals (Sweden)

    Pirtle Jody M.

    2012-01-01

    Full Text Available The purpose of this study was to identify and examine the themes in the written productions of 114 kindergarten students. Participants were from two schools in different regions in the United States and were given an open-ended opportunity to draw and subsequently dictate a story. Content analysis was performed and six themes emerged: (a family, (b inanimate objects/personal belongings, (c activities/events, (d fantasy stories, (e self-talk/reflection, and (f nature/outdoors. Comparative analysis was performed for both gender and ethnicity and few differences were found between boys’ and girls’ stories or across ethnicities. Recommendations were included for teachers and families to allow young children more open-ended literacy opportunities and future research to analyze children’s drawings and stories between classrooms and across grade levels were included.

  12. Motives for Volunteering: Categorization of Volunteers' Motivations Using Open-ended Questions

    Directory of Open Access Journals (Sweden)

    Fernando Chacón

    2010-12-01

    Full Text Available Most studies of volunteers’ motivations use standardized questionnaires with one of the most commonly-used being the Volunteer Function Inventory. Open-ended questions about what drives individuals to be volunteers are seldom used. We hypothesize that questionnaires tend to overestimate the number of motivations and to underestimate their variety. Therefore, in this paper we analyze the answers of 1515 volunteers to an open-ended question and categorize these answers. Results show that volunteers give an average of 2 motivations, fewer than the questionnaires, and that the Value motivation is the most frequently mentioned and the most important for volunteers. In addition, this motivation coexists with other motivations, which are lacking in the standard questionnaires, such as Organizational Commitment, Personal Development, Religiosity, Social Change or Interest in the Activity.

  13. Ambiguity towards Multiple Historical Performance Information Signals: Evidence from Indonesian Open-Ended Mutual Fund Investors

    Directory of Open Access Journals (Sweden)

    Haris Pratama Loeis

    2015-10-01

    Full Text Available This study focuses on the behavior of open-ended mutual fund investors when encountered with multiple information signals of mutual fund’s historical performance. The behavior of investors can be reflected on their decision to subscribe or redeem their funds from mutual funds. Moreover, we observe the presence of ambiguity within investors due to multiple information signals, and also their reaction towards it. Our finding shows that open-ended mutual fund investors do not only have sensitivity towards past performance information signals, but also have additional sensitivity towards the ambiguity of multiple information signals. Because of the presence of ambiguity, investors give more consideration to negative information signals and the worst information signal in their investment decisions. Normal 0 false false false EN-US X-NONE X-NONE

  14. Virtual and physical toys: open-ended features for non-formal learning.

    Science.gov (United States)

    Petersson, Eva; Brooks, Anthony

    2006-04-01

    This paper examines the integrated toy--both physical and virtual--as an essential resource for collaborative learning. This learning incorporates rehabilitation, training, and education. The data derived from two different cases. Pedagogical issues related to non-formal learning and open-ended features of design are discussed. Findings suggest that social, material, and expressive affordances constitute a base for an alterative interface to encourage children's play and learning.

  15. Using Stepwise Reality Check to Analyze Open-end Fund Investors’Herding Redemption in Taiwan

    OpenAIRE

    Nan-Yu Wang; Chih-Jen Huang; Ying-Lin Hsu; Shian-Chang Huang

    2015-01-01

    This study aims to examine whether funds with illiquid assets exhibit stronger sensitivity of redemption outflows to bad past performance than funds with liquid assets. An important aspect of our study is whether large outflows should damage future fund performance in illiquid funds more than in liquid funds. When redeemed in a large scale, the liquidity risk of open-end funds will increase, which in turn leads to a vicious circle between fund redemption and the net asset value decline. Accor...

  16. Microwave Interferometry Based On Open-ended Coaxial Technique for High Sensitivity Liquid Sensing

    Directory of Open Access Journals (Sweden)

    H. Bakli

    2017-10-01

    Full Text Available This paper describes a modified open-ended coaxial technique for microwave dielectric characterization in liquid media. A calibration model is developed to relate the measured transmission coefficient to the local properties of the sample under test. As a demonstration, the permittivity of different sodium chloride solutions is experimentally determined. Accuracies of 0.17% and 0.19% are obtained respectively for the real and imaginary parts of dielectric permittivity at 5.9 GHz.

  17. Open-ended and Open-door Treatment Groups for Young People with Mental Illness.

    Science.gov (United States)

    Miller, Rachel; Mason, Susan E

    2012-01-01

    The concept of open-ended groups is expanded to include an open-door model (OEOD) wherein members with severe mental illnesses, including schizophrenia disorders and bi-polar, can join, leave, and re-enter groups as their life circumstances dictate their availability and willingness for treatment. This model is grounded on the work of Schopler and Galinsky's (1984/2006) and Galinsky and Schopler's (1989) theses on the value and processes of open-ended groups and includes perspectives on mutual aid and group development. Groupwork with the OEOD format is illustrated with examples taken from a group of 79 participants diagnosed with first-episode schizophrenia/schizoaffective disorders, 40 of who had co-occurring substance abuse. Of the 79 participants in the OEOD group program, 70 (89%) remained in treatment for the maximum of 3 years. The over-all value of group treatment for this population is reviewed along with the small number of available publications on open-ended and open-door-type groups.

  18. Metacognition Difficulty of Students with Visual-Spatial Intelligence during Solving Open-Ended Problem

    Science.gov (United States)

    Rimbatmojo, S.; Kusmayadi, T. A.; Riyadi, R.

    2017-09-01

    This study aims to find out students metacognition difficulty during solving open-ended problem in mathematics. It focuses on analysing the metacognition difficulty of students with visual-spatial intelligence in solving open-ended problem. A qualitative research with case study strategy is used in this study. Data in the form of visual-spatial intelligence test result and recorded interview during solving open-ended problems were analysed qualitatively. The results show that: (1) students with high visual-spatial intelligence have no difficulty on each metacognition aspects, (2) students with medium visual-spatial intelligence have difficulty on knowledge aspect on strategy and cognitive tasks, (3) students with low visual-spatial intelligence have difficulty on three metacognition aspects, namely knowledge on strategy, cognitive tasks and self-knowledge. Even though, several researches about metacognition process and metacognition literature recommended the steps to know the characteristics. It is still important to discuss that the difficulties of metacognitive is happened because of several factors, one of which on the characteristics of student’ visual-spatial intelligence. Therefore, it is really important for mathematics educators to consider and pay more attention toward students’ visual-spatial intelligence and metacognition difficulty in designing better mathematics learning.

  19. Open-ended versus guided laboratory activities:Impact on students' beliefs about experimental physics

    Science.gov (United States)

    Wilcox, Bethany R.; Lewandowski, H. J.

    2016-12-01

    Improving students' understanding of the nature of experimental physics is often an explicit or implicit goal of undergraduate laboratory physics courses. However, lab activities in traditional lab courses are typically characterized by highly structured, guided labs that often do not require or encourage students to engage authentically in the process of experimental physics. Alternatively, open-ended laboratory activities can provide a more authentic learning environment by, for example, allowing students to exercise greater autonomy in what and how physical phenomena are investigated. Engaging in authentic practices may be a critical part of improving students' beliefs around the nature of experimental physics. Here, we investigate the impact of open-ended activities in undergraduate lab courses on students' epistemologies and expectations about the nature of experimental physics, as well as their confidence and affect, as measured by the Colorado Learning Attitudes about Science Survey for Experimental Physics (E-CLASS). Using a national data set of student responses to the E-CLASS, we find that the inclusion of some open-ended lab activities in a lab course correlates with more expertlike postinstruction responses relative to courses that include only traditional guided lab activities. This finding holds when examining postinstruction E-CLASS scores while controlling for the variance associated with preinstruction scores, course level, student major, and student gender.

  20. Determining the Response Behaviors of Middle School Students for Open-Ended Questions

    Directory of Open Access Journals (Sweden)

    Neslihan Tuğçe ŞİMŞEK

    2017-04-01

    Full Text Available When the literature for measurement and evaluation in education is reviewed, research related to student achievement are mainly outcome-oriented rather than process-oriented. Researchers pay attention to the responses that a student constructs or chooses, and ignore the cognitive processes that forces students to construct or choose that specific response. Recognizing the cognitive processes a student uses in responding to a question affects the item construction process and psychometric audit on items. Response behavior is a result of a cognitive process used to respond to a question and is accepted as an indicator of student cognitive competence. This study aims to determine the students’ response behaviors for open-ended questions. The study group consisted of 70 students from the 5th grade studying during the 2015-2016 education year spring term in the Cankaya and Mamak districts of Ankara province, Turkey. An authentic achievement test which consisted of eight open-ended questions is used as the data collection tool. Students are asked to write in detail how they construct their response in their mind in the blank space set aside after each question. Data is analyzed via grouping students’ response behaviors and expert opinions. Research findings revealed that students perform 14 different response behaviors for open-ended questions. These behaviors are themed as responses constructed directly from the text, responses constructed by interpreting the text, and responses constructed by linking real life and the text.

  1. Undecidability and Irreducibility Conditions for Open-Ended Evolution and Emergence.

    Science.gov (United States)

    Hernández-Orozco, Santiago; Hernández-Quiroz, Francisco; Zenil, Hector

    2018-01-01

    Is undecidability a requirement for open-ended evolution (OEE)? Using methods derived from algorithmic complexity theory, we propose robust computational definitions of open-ended evolution and the adaptability of computable dynamical systems. Within this framework, we show that decidability imposes absolute limits on the stable growth of complexity in computable dynamical systems. Conversely, systems that exhibit (strong) open-ended evolution must be undecidable, establishing undecidability as a requirement for such systems. Complexity is assessed in terms of three measures: sophistication, coarse sophistication, and busy beaver logical depth. These three complexity measures assign low complexity values to random (incompressible) objects. As time grows, the stated complexity measures allow for the existence of complex states during the evolution of a computable dynamical system. We show, however, that finding these states involves undecidable computations. We conjecture that for similar complexity measures that assign low complexity values, decidability imposes comparable limits on the stable growth of complexity, and that such behavior is necessary for nontrivial evolutionary systems. We show that the undecidability of adapted states imposes novel and unpredictable behavior on the individuals or populations being modeled. Such behavior is irreducible. Finally, we offer an example of a system, first proposed by Chaitin, that exhibits strong OEE.

  2. Financial Investments in Romania. A Comparative Analysis between Open-end Mutual Funds and Bank Deposits

    Directory of Open Access Journals (Sweden)

    Pop Izabela Luiza

    2017-01-01

    Full Text Available Despite the failures that investment funds have registered in Romania by the year 2000, they are a financial instrument chosen by more and more people to capitalize on their savings. Therefore, open-end investment funds have had a steady growth trend in Romania over the past 10 years; their net asset value increased by 24 times and the number of investors tripled. In this context, the purpose of our paper is to present possible factors that have caused this increase. Particularly, the empirical research focuses on studying the links that might exist between open-end investment funds, bank deposits and interest rates on bank deposits. The correlations between these variables were analysed by computing the Pearson's correlation coefficient. The results highlight a high negative relationship that exist between net asset value of investment funds and bank interest. Nevertheless, it has been found that bank deposits are related neither to the interest rate nor to the open-end investment funds.

  3. Magnetic susceptibility in the edged topological disordered nanoscopic cylinder

    International Nuclear Information System (INIS)

    Faizabadi, Edris; Omidi, Mahboubeh

    2011-01-01

    The effects of edged topological disorder on magnetic susceptibility are investigated in a nanoscopic cylinder threaded by a magnetic flux. Persistent current versus even or odd number of electrons shows different signs in ordered and disordered cylinders and also in short or long ones. In addition, temperature-averaged susceptibility has only diamagnetic signs in strong regimes and it is associated with paramagnetic signs in ordered and weak disordered ones. Besides, in an edged topological disordered cylinder, the temperature-averaged susceptibility decreases by raising the temperature somewhat and then increasing initiates and finally at high temperature tends to zero as the ordered one. - Research highlights: → Magnetic susceptibility in one-dimensional topological disordered quantum ring. → Edged topological disorder effect on magnetic susceptibility in nanoscopic cylinder. → Edged topological disorder effect on temperature-averaged susceptibility in cylinder.

  4. Unusual buffer action of free-standing nanoscopically confined water.

    Science.gov (United States)

    Liao, Kylin; Xu, Xiaozhou; Du, Xuezhong

    2010-01-15

    The acid-base properties of nanoscopic water confined in the black soap films (BSFs), which were prepared from aqueous solutions of sodium dodecylsulphate (SDS) with the dye neutral red (NR) as a pH probe, were investigated using a combination of UV-vis and FTIR spectroscopy. For the SDS micellar solutions at pH 1.0-9.5 adjusted with HCl/NaOH solutions and at pH 9.4 with ammonium buffered solution, the aqueous core thicknesses in the corresponding BSFs ranged from 2.7 to 6.2 nm, and the nanoscopically confined water exhibits unusual buffer action resistant not only to acidic/alkaline solutions but also to standard buffer solution. In the heavily water-depleted confined zones, it is most likely that charge pairs in proton-transfer reactions could not be formed effectively and proton transfer was prohibited in the absence of sufficient solvating ability. Theoretical analyzes indicated that the buffer action of the nanoscopic water originated from the confinement effect of two charged surfaces of the BSFs. These results might inspire deeper understanding and further studies of biobuffering, enzyme superactivity, acid-catalyzed reactions, and Nafion fuel cell membranes.

  5. 17 CFR 274.11 - Form N-1, registration statement of open-end management investment companies.

    Science.gov (United States)

    2010-04-01

    ... statement of open-end management investment companies. 274.11 Section 274.11 Commodity and Securities Exchanges SECURITIES AND EXCHANGE COMMISSION (CONTINUED) FORMS PRESCRIBED UNDER THE INVESTMENT COMPANY ACT...(b) of the Investment Company Act of 1940 by open-end management investment companies that are...

  6. 17 CFR 239.15A - Form N-1A, registration statement of open-end management investment companies.

    Science.gov (United States)

    2010-04-01

    ... statement of open-end management investment companies. 239.15A Section 239.15A Commodity and Securities... Registration Statements § 239.15A Form N-1A, registration statement of open-end management investment companies... management investment companies other than separate accounts of insurance companies registered under the...

  7. Investigating Students' Success in Solving and Attitudes towards Context-Rich Open-Ended Problems in Chemistry

    Science.gov (United States)

    Overton, Tina L.; Potter, Nicholas M.

    2011-01-01

    Much research has been carried out on how students solve algorithmic and structured problems in chemistry. This study is concerned with how students solve open-ended, ill-defined problems in chemistry. Over 200 undergraduate chemistry students solved a number of open-ended problem in groups and individually. The three cognitive variables of…

  8. Magnetic integration of the harmonic filter inductor for dual-converter fed open-end transformer topology

    DEFF Research Database (Denmark)

    Gohil, Ghanshyamsinh Vijaysinh; Bede, Lorand; Teodorescu, Remus

    2016-01-01

    Many high power converter systems are often connected to the medium voltage network using a step-up transformer. In such systems, the converter-side windings of the transformer can be configured as an open-end and multi-level voltage waveforms can be achieved by feeding these open-end windings from...

  9. Open-Ended Cases in Agroecology: Farming and Food Systems in the Nordic Region and the US Midwest

    Science.gov (United States)

    Francis, Charles; King, James; Lieblein, Geir; Breland, Tor Arvid; Salomonsson, Lennart; Sriskandarajah, Nadarajah; Porter, Paul; Wiedenhoeft, Mary

    2009-01-01

    Our aim is to describe open-ended case studies for learning real-life problem solving skills, and relate this approach to conventional, closed-ended decision case studies. Teaching methods are open-ended cases in agroecology, an alternative to traditional strategies that lead students through prepared materials and structured discussions to…

  10. Wakefield radiation from the open end of an internally coated metallic tube

    Directory of Open Access Journals (Sweden)

    M. Ivanyan

    2014-07-01

    Full Text Available In this paper the problem of radiation from the open end of a semi-infinite circular metallic waveguide with perfectly conducting walls and a thin internal low-conducting metal coating is considered. Electromagnetic fields are generated by the ultrarelativistic point charge moving along the axis of the waveguide. The far fields of radiation are obtained using the near-field to far-field recovery technique. The technique is extended for the nonmonochromatic waves. It is shown that the radiation has a narrow-band and narrow-directional character.

  11. Open-end tube dynamic flow model with an oscillatory extortion

    Directory of Open Access Journals (Sweden)

    Tulwin Tytus

    2017-01-01

    Full Text Available This paper presents a derivation of dynamic 2d mathematical model for open end tube with oscillatory extortion in the region of the closed end. The aim the research is to investigate possible uses of the increased pressure in the enclosed tube chamber, especially for energy efficient lift generation. The mathematical model allows to test and predict how flow modifications impact the resultant lifting force. A derivation of the proposed mathematical model is shown. The mathematical model is then compared to the computational fluid dynamics discrete model. The results prove the accuracy of the mathematical physical model.

  12. Student’s Critical Thinking in Solving Open-Ended Problems Based on Their Personality Type

    Science.gov (United States)

    Fitriana, L. D.; Fuad, Y.; Ekawati, R.

    2018-01-01

    Critical thinking plays an important role for students in solving open-ended problems. This research aims at describing student’s critical thinking in solving open-ended problems based on Keirsey’s personality types, namely rational, idealist, guardian, and artisan. Four students, with the higher rank in the mathematics’ test and representing each type of Keirsey personality, were selected as the research subjects. The data were collected from the geometry problem and interviews. The student’s critical thinking is described based on the FRISCO criteria. The result underlines that rational and idealist students fulfilled all FRISCO criteria, and but not for guardian and artisan students. Related to the inference criteria, guardian and artisan students could not make reasonable conclusions and connect the concepts. Related to the reason of criteria, rational student performed critical thinking by providing logical reason that supported his strategy to solve the problem. In contrast, the idealist student provided subjective reason. This results suggest that teachers should frequently train the students’ logical thinkingin every lesson and activity to develop student’s critical thinking and take the student’s personality character into account, especially for guardian and artisan students.

  13. The Use of Open-Ended Questions with Giving Feedback (OEQGF) for Effective Mathematic Learning

    Science.gov (United States)

    Sabilah, I.; Manoy, J. T.

    2018-01-01

    Feedback deals with giving information to students related to their task which is done through score of their achievement, reaction, and comments. Considering its hierarchy, task difficulty level consists of low, middle and high levels. The difficulty level of open-ended questions is middle to high. Open-ended question is a good way to train students’ knowledge. This research is a descriptive research which aims at describing teacher’s learning management, students’ activities, students’ learning achievement, and students’ responses in mathematic learning using OEQGF. The subject was a teacher of mathematics who teaches eighth graders, and students themselves. The research design used is one shot case study. The result shows that: management learning has been very well implemented by the teacher; every students’ activity has been carried out by students; the students’ learning achievement have reached the criteria of completeness, and the students’ responses can be considered as positive. Therefore, it can be concluded that mathematic learning using OEQGF is effective.

  14. Temporal and Spatial Patterns of Neural Activity Associated with Information Selection in Open-ended Creativity.

    Science.gov (United States)

    Zhou, Siyuan; Chen, Shi; Wang, Shuang; Zhao, Qingbai; Zhou, Zhijin; Lu, Chunming

    2018-02-10

    Novel information selection is a crucial process in creativity and was found to be associated with frontal-temporal functional connectivity in the right brain in closed-ended creativity. Since it has distinct cognitive processing from closed-ended creativity, the information selection in open-ended creativity might be underlain by different neural activity. To address this issue, a creative generation task of Chinese two-part allegorical sayings was adopted, and the trials were classified into novel and normal solutions according to participants' self-ratings. The results showed that (1) novel solutions induced a higher lower alpha power in the temporal area, which might be associated with the automatic, unconscious mental process of retrieving extensive semantic information, and (2) upper alpha power in both frontal and temporal areas and frontal-temporal alpha coherence were higher in novel solutions than in normal solutions, which might reflect the selective inhibition of semantic information. Furthermore, lower alpha power in the temporal area showed a reduction with time, while the frontal-temporal and temporal-temporal coherence in the upper alpha band appeared to increase from the early to the middle phase. These dynamic changes in neural activity might reflect the transformation from divergent thinking to convergent thinking in the creative progress. The advantage of the right brain in frontal-temporal connectivity was not found in the present work, which might result from the diversity of solutions in open-ended creativity. Copyright © 2017 IBRO. Published by Elsevier Ltd. All rights reserved.

  15. PEMBELAJARAN KONTEKSTUAL OPEN ENDED PROBLEM SOLVING DENGAN KOMIK MATEMATIKA UNTUK MENINGKATKAN KETERAMPILAN PEMECAHAN MASALAH

    Directory of Open Access Journals (Sweden)

    Lenny Kurniati

    2017-01-01

    ABSTRACT The aim of this research to develop a mathematics learning instrument using contextual open ended problem solving with mathematic comic to increase the problem solving skill which valid, practical and effective. The type of research used in this study is development research using modification of Plomp model. Learning instrumen that have been develop are: syllabus, Lesson plan, worksheet, mathematics comic, and problem solving ability test. The results showed: (1 device developed valid; (2 practical learning is characterized by the positive response of students and good teachers ability, (3 Effectiveness characterized by (a problem solving ability score of the experimental class higher than minimum completeness criterion, (b learn interest and problem solving skill, both affected the problem solving ability positively,  (c problem solving ability of the experimental class score is higher than the control class, (d problem solving skill of the experimental class is increasing by 31%, the problem solving ability of the experimental class higher than the control class.. Because of the learning instrument develope are valid, practice and effective, it is shows that the research has ben reach out. Keywords: contextual teaching and learning, open ended problem solving, mathematics comic, problem solving.

  16. Comparison of performance on multiple-choice questions and open-ended questions in an introductory astronomy laboratory

    OpenAIRE

    Michelle M. Wooten; Adrienne M. Cool; Edward E. Prather; Kimberly D. Tanner

    2014-01-01

    When considering the variety of questions that can be used to measure students’ learning, instructors may choose to use multiple-choice questions, which are easier to score than responses to open-ended questions. However, by design, analyses of multiple-choice responses cannot describe all of students’ understanding. One method that can be used to learn more about students’ learning is the analysis of the open-ended responses students’ provide when explaining their multiple-choice response. I...

  17. Open-Ended Interaction in Cooperative Pro-to-typing: A Video-based Analysis

    DEFF Research Database (Denmark)

    Bødker, Susanne; Grønbæk, Kaj; Trigg, Randal

    1991-01-01

    Cooperative Prototyping can be characterized as the use and development of prototypes as catalysts during discussions between designers and potential users – the overall intention being one of mutual learning. On the one hand, the designers learn more about the work practices of the users in ways...... that are tied concretely to some current version of the prototype. On the other hand, the users learn more about the potential for change in their work practice, whether computer-based or otherwise. This paper presents the results of a field study of the cooperative prototyping process. The study is based...... on a fine-grained video-based analysis of a single prototyping session, and focuses on the effects of an open-ended style of interaction between users and designers around a prototype. An analysis of focus shifts, initiative and storytelling during the session is brought to bear on the question of whether...

  18. Field-oriented control of five-phase induction motor with open-end stator winding

    Directory of Open Access Journals (Sweden)

    Listwan Jacek

    2016-09-01

    Full Text Available The mathematical model of the five-phase squirrel-cage induction motor and the system of the dual five-phase voltage source inverter have been presented. The control methods and control systems of the field-oriented control of the five-phase induction motor with an open-end stator winding are described. The structures of the direct fieldoriented control system (DFOC and the Indirect Field-oriented control system (IFOC with PI controllers in outer and inner control loops are analyzed. A method of space vector modulation used to control the system of the dual five-phase voltage source inverter has been discussed. The results of simulation studies of the field-oriented control methods are presented. Comparative analysis of the simulation results was carried out.

  19. Effect of filling ratio on premixed methane/air explosion in an open-end pipe

    Directory of Open Access Journals (Sweden)

    Chang Guo

    2016-06-01

    Full Text Available The propagation characteristics of premixed methane/air explosion under different filling ratios (20%, 30%, 40%, 50%, 60%, and 100% were studied using an experimental system. The results indicate that the peak overpressure showed a decreasing trend at the initial stage but then showed an increasing trend until reaching its maximum value under different filling ratios. As the explosion propagated to the open end, the overpressure showed a downtrend. At this point, the flame speed initially increased along the pipe but then dropped dramatically. In addition, the explosion overpressure and flame speed increased with the increase of filling ratio. However, when the filling ratio reached 50%, the explosion overpressure and flame speed tended to be stable and the increase was not obvious. These results will be of great importance in evaluating the explosive damage to equipment and human personnel working in coal mines or other chemical industries.

  20. Physics of zero- and one-dimensional nanoscopic systems

    CERN Document Server

    Maiti, Santanu; Chowdhury, Jayeeta

    2007-01-01

    In recent years submicron and nanoscale systems have featured strongly on the research agenda due to the technological progress and new physics that have emerged from studies of ultra-small systems. A fundamental understanding of basic physical phenomena on the mesoscopic and nanoscopic scales is required to exploit the technological potential offered by these exotic materials. The present book contains review-like chapters by some of the leading experts in the field, covering topics such as the Kondo effect, electron transport, disorder and quantum coherence with electron-electron interaction, persistent current, thermoelectric phenomena, etc. in quantum dots, quantum wires, carbon nanotubes and more. This book will be valuable to researchers and students in condensed matter physics.

  1. Formal Definitions of Unbounded Evolution and Innovation Reveal Universal Mechanisms for Open-Ended Evolution in Dynamical Systems.

    Science.gov (United States)

    Adams, Alyssa; Zenil, Hector; Davies, Paul C W; Walker, Sara Imari

    2017-04-20

    Open-ended evolution (OEE) is relevant to a variety of biological, artificial and technological systems, but has been challenging to reproduce in silico. Most theoretical efforts focus on key aspects of open-ended evolution as it appears in biology. We recast the problem as a more general one in dynamical systems theory, providing simple criteria for open-ended evolution based on two hallmark features: unbounded evolution and innovation. We define unbounded evolution as patterns that are non-repeating within the expected Poincare recurrence time of an isolated system, and innovation as trajectories not observed in isolated systems. As a case study, we implement novel variants of cellular automata (CA) where the update rules are allowed to vary with time in three alternative ways. Each is capable of generating conditions for open-ended evolution, but vary in their ability to do so. We find that state-dependent dynamics, regarded as a hallmark of life, statistically out-performs other candidate mechanisms, and is the only mechanism to produce open-ended evolution in a scalable manner, essential to the notion of ongoing evolution. This analysis suggests a new framework for unifying mechanisms for generating OEE with features distinctive to life and its artifacts, with broad applicability to biological and artificial systems.

  2. The Cultural Evolution of Structured Languages in an Open-Ended, Continuous World.

    Science.gov (United States)

    Carr, Jon W; Smith, Kenny; Cornish, Hannah; Kirby, Simon

    2017-05-01

    Language maps signals onto meanings through the use of two distinct types of structure. First, the space of meanings is discretized into categories that are shared by all users of the language. Second, the signals employed by the language are compositional: The meaning of the whole is a function of its parts and the way in which those parts are combined. In three iterated learning experiments using a vast, continuous, open-ended meaning space, we explore the conditions under which both structured categories and structured signals emerge ex nihilo. While previous experiments have been limited to either categorical structure in meanings or compositional structure in signals, these experiments demonstrate that when the meaning space lacks clear preexisting boundaries, more subtle morphological structure that lacks straightforward compositionality-as found in natural languages-may evolve as a solution to joint pressures from learning and communication. Copyright © 2016 The Authors. Cognitive Science published by Wiley Periodicals, Inc. on behalf of Cognitive Science Society.

  3. Open-ended response theory with polarizable embedding: multiphoton absorption in biomolecular systems.

    Science.gov (United States)

    Steindal, Arnfinn Hykkerud; Beerepoot, Maarten T P; Ringholm, Magnus; List, Nanna Holmgaard; Ruud, Kenneth; Kongsted, Jacob; Olsen, Jógvan Magnus Haugaard

    2016-10-12

    We present the theory and implementation of an open-ended framework for electric response properties at the level of Hartree-Fock and Kohn-Sham density functional theory that includes effects from the molecular environment modeled by the polarizable embedding (PE) model. With this new state-of-the-art multiscale functionality, electric response properties to any order can be calculated for molecules embedded in polarizable atomistic molecular environments ranging from solvents to complex heterogeneous macromolecules such as proteins. In addition, environmental effects on multiphoton absorption (MPA) properties can be studied by evaluating single residues of the response functions. The PE approach includes mutual polarization effects between the quantum and classical parts of the system through induced dipoles that are determined self-consistently with respect to the electronic density. The applicability of our approach is demonstrated by calculating MPA strengths up to four-photon absorption for the green fluorescent protein. We show how the size of the quantum region, as well as the treatment of the border between the quantum and classical regions, is crucial in order to obtain reliable MPA predictions.

  4. Ethics roundtable: 'Open-ended ICU care: can we afford it?'.

    Science.gov (United States)

    Crippen, David; Burrows, Dick; Stocchetti, Nino; Mayer, Stephan A; Andrews, Peter; Bleck, Tom; Whetstine, Leslie

    2010-01-01

    The patient is a 27-year-old previously healthy male with a diagnosis of viral encephalitis with a lymphocytic pleocytosis on cerebrospinal fluid examination. For 3 months, he has been in status epilepticus (SE) on high doses of barbiturates, benzodiazepines, and ketamine and a ketogenic feeding-tube formula. He remains in burst suppression on continuous electroencephalography (EEG). He is trached and has a percutaneous endoscopic gastrostomy (PEG) feeding tube. He has been treated several times for pneumonia, and he is on a warming blanket and is on vasopressors to maintain his blood pressure. His vitals are stable and his lab work is within limits. The sedation is decreased under EEG guidance every 72 hours, after which he goes back into SE and heavy sedation is resumed. The latest magnetic resonance imaging (MRI) shows edema but otherwise no obvious permanent cortical damage. The family wants a realistic assessment of the likely outcome. The neurologist tells them the literature suggests the outlook is poor but not 100% fatal. As long as all of his other organs are functioning on life support, there is always a chance the seizures will stop at some time in the future, and so the neurologist recommends an open-ended intensive care unit (ICU) plan and hopes for that outcome.

  5. Open-Ended Measurement of Whole-Body Movement: A Feasibility Study

    Directory of Open Access Journals (Sweden)

    Finn, Michael T. M.

    2018-02-01

    Full Text Available As the importance of embodiment emerges for psychology, there is a need to advance methodology for measuring the dynamics of movement in an open-ended fashion. Such a tool should be versatile across contexts and track spontaneous and natural movement with minimal constraints. We test the feasibility of a method for measuring whole-body movement over time that attempts to meet this need. We use a motion capture system comprised of two Microsoft Kinect version 2.0 cameras and iPiSoft Motion Capture software, and compare its estimates of magnitude rotational velocity and whole-body movement complexity (multivariate multiscale sample entropy; MMSE to that of a gold standard motion capture system across a variety of movement sequences. The candidate system satisfactorily estimated the instantaneous velocity of 13 body segments in agreement with the gold standard system across movement sequences demonstrating initial feasibility of this process. Summary calculations of velocity by sequence and MMSE calculations were also in high agreement with the gold standard, crucially suggesting that the candidate system could pick up on the complex dynamics of movement over time. The candidate system was feasible and demonstrates preliminary validity for general use in the tracking of continuous human movement for clinical and experimental psychology. We also provide R code and sample data for the importing and processing of movement data exported from iPiSoft Motion Capture Studio.

  6. Vortex ring formation at the open end of a shock tube: A particle image velocimetry study

    Science.gov (United States)

    Arakeri, J. H.; Das, D.; Krothapalli, A.; Lourenco, L.

    2004-04-01

    The vortex ring generated subsequent to the diffraction of a shock wave from the open end of a shock tube is studied using particle image velocimetry. We examine the early evolution of the compressible vortex ring for three-exit shock Mach numbers, 1.1, 1.2, and 1.3. For the three cases studied, the ring formation is complete at about tUb/D=2, where t is time, Ub is fluid velocity behind shock as it exits the tube and D is tube diameter. Unlike in the case of piston generated incompressible vortex rings where the piston velocity variation with time is usually trapezoidal, in the shock-generated vortex ring case the exit fluid velocity doubles from its initial value Ub before it slowly decays to zero. At the end of the ring formation, its translation speed is observed to be about 0.7 Ub. During initial formation and propagation, a jet-like flow exists behind the vortex ring. The vortex ring detachment from the tailing jet, commonly referred to as pinch-off, is briefly discussed.

  7. Experimental study on pressure wave propagation through the open end of pipe

    International Nuclear Information System (INIS)

    Yoshida, K.; Kumagai, H.

    1994-01-01

    The steam generators of a double pool type liquid metal fast breeder reactor (LMFBR) are used in a large sodium pool which is formed between the primary vessel and the secondary vessel and accommodates the entire secondary heat transport system. Therefore, if there is a sodium-water reaction event in the steam generator, it becomes important to evaluate the pressure rises at the walls of the primary and secondary vessels as well as those at the other secondary components. An experimental study was performed, focusing on the propagation of the initial pressure spike of the-sodium-water reaction from the bottom end of the steam generator to the sodium pool. Pressure wave propagation from inside of a pipe to an open space through the pipe end was measured. Two kinds of pressure propagation media, water and air, ensured a wide range of experimental conditions. The experimental results revealed that the pressure attenuation at the open end of a pipe can be put in order using the concept of inertial length, and that the dimensionless inertial length, i.e., the inertial length divided by the half wave length of the pressure pulse, is proportional to the square of the dimensionless diameter. These results provide a prediction method for a pressure rise by the initial pressure spike in the secondary sodium pool of the Double Pool LMFBR

  8. MENINGKATKAN KEMAMPUAN PEMECAHAN MASALAH MATEMATIS DAN SELF-CONCEPT CALON GURU DI KABUPATEN KARAWANG MELALUI PENDEKATAN OPEN-ENDED

    Directory of Open Access Journals (Sweden)

    Hendra Kartika

    2017-12-01

    Full Text Available This study aims to investigate open-ended learning approach in improving undergraduate students’ mathematical problem-solving ability and self-concept toward linear algebra subject. Population in this study is mathematics education students FKIP Unsika in four semesters that takes linear algebra courses while the sample is two classes became experiment class and control class. The research design that used in this study is non-equivalent control group design. Results show that undergraduate students’ mathematical problem-solving ability and self-concept who followed open-ended learning approach were fostered significantly compared to undergraduate students’ who received conventional teaching method.

  9. Using Negotiated Joining to Construct and Fill Open-ended Roles in Elite Culinary Groups.

    Science.gov (United States)

    Tan, Vaughn

    2015-03-01

    This qualitative study examines membership processes in groups operating in an uncertain environment that prevents them from fully predefining new members' roles. I describe how nine elite high-end, cutting-edge culinary groups in the U.S. and Europe, ranging from innovative restaurants to culinary R&D groups, use negotiated joining-a previously undocumented process-to systematically construct and fill these emergent, open-ended roles. I show that negotiated joining is a consistently patterned, iterative process that begins with a role that both aspirant and target group explicitly understand to be provisional. This provisional role is then jointly modified and constructed by the aspirant and target group through repeated iterations of proposition, validation through trial and evaluation, and selective integration of validated role components. The initially provisional role stabilizes and the aspirant achieves membership if enough role components are validated; otherwise the negotiated joining process is abandoned. Negotiated joining allows the aspirant and target group to learn if a mutually desirable role is likely and, if so, to construct such a role. In addition, the provisional roles in negotiated joining can support absorptive capacity by allowing novel role components to enter target groups through aspirants' efforts to construct stable roles for themselves, while the internal adjustment involved in integrating newly validated role components can have the unintended side effect of supporting adaptation by providing opportunities for the groups to use these novel role components to modify their role structure and goals to suit a changing and uncertain environment. Negotiated joining thus reveals role ambiguity's hitherto unexamined beneficial consequences and provides a foundation for a contingency theory of new-member acquisition.

  10. Comparison of Performance on Multiple-Choice Questions and Open-Ended Questions in an Introductory Astronomy Laboratory

    Science.gov (United States)

    Wooten, Michelle M.; Cool, Adrienne M.; Prather, Edward E.; Tanner, Kimberly D.

    2014-01-01

    When considering the variety of questions that can be used to measure students' learning, instructors may choose to use multiple-choice questions, which are easier to score than responses to open-ended questions. However, by design, analyses of multiple-choice responses cannot describe all of students' understanding. One method that can…

  11. A Multimode Equivalent Network Approach for the Analysis of a 'Realistic' Finite Array of Open Ended Waveguides

    NARCIS (Netherlands)

    Neto, A.; Bolt, R.; Gerini, G.; Schmitt, D.

    2003-01-01

    In this contribution we present a theoretical model for the analysis of finite arrays of open-ended waveguides mounted on finite mounting platforms or having radome coverages. This model is based on a Multimode Equivalent Network (MEN) [1] representation of the radiating waveguides complete with

  12. Open-Ended Approach: An Effort in Cultivating Students' Mathematical Creative Thinking Ability and Self-Esteem in Mathematics

    Science.gov (United States)

    Fatah, Abdul; Suryadi, Didi; Sabandar, Jozua; Turmudi

    2016-01-01

    The present study aims at examining the use of open-ended approach in cultivating senior high school students' mathematical creative thinking ability (MCTA) and self-esteem (SE) in mathematics viewed from school category. The subjects of this research were the students grade XI at three schools; high, middle and low category in Kota Serang, Banten…

  13. Exploring droplet impact near a millimetre-sized hole: comparing a closed pit with an open-ended pore

    NARCIS (Netherlands)

    de Jong, Rianne; Enriquez Paz y Puente, O.R.; van der Meer, Roger M.

    2015-01-01

    We investigate drop impact dynamics near closed pits and open-ended pores experimentally. The resulting impact phenomena differ greatly in each case. For a pit, we observe three distinct phenomena, which we denote as a splash, a jet and an air bubble, whose appearance depends on the distance between

  14. Learning autonomy in two or three steps : linking open-ended development, authority, and agency to motivation

    NARCIS (Netherlands)

    Andringa, Tjeerd; van den Bosch, Kirsten; Vlaskamp, Carla

    2013-01-01

    In this paper we connect open-ended development, authority, agency, and motivation through (1) an analysis of the demands of existing in a complex world and (2) environmental appraisal in terms of affordance content and the complexity to select appropriate behavior. We do this by identifying a

  15. Open-Ended Science Inquiry in Lower Secondary School: Are Students' Learning Needs Being Met?

    Science.gov (United States)

    Whannell, Robert; Quinn, Fran; Taylor, Subhashni; Harris, Katherine; Cornish, Scott; Sharma, Manjula

    2018-01-01

    Australian science curricula have promoted the use of investigations that allow secondary students to engage deeply with the methods of scientific inquiry, through student-directed, open-ended investigations over an extended duration. This study presents the analysis of data relating to the frequency of completion and attitudes towards long…

  16. Multiple Problem-Solving Strategies Provide Insight into Students' Understanding of Open-Ended Linear Programming Problems

    Science.gov (United States)

    Sole, Marla A.

    2016-01-01

    Open-ended questions that can be solved using different strategies help students learn and integrate content, and provide teachers with greater insights into students' unique capabilities and levels of understanding. This article provides a problem that was modified to allow for multiple approaches. Students tended to employ high-powered, complex,…

  17. Communicating Quantitative Literacy: An Examination of Open-Ended Assessment Items in TIMSS, NALS, IALS, and PISA

    Directory of Open Access Journals (Sweden)

    Karl W. Kosko

    2011-07-01

    Full Text Available Quantitative Literacy (QL has been described as the skill set an individual uses when interacting with the world in a quantitative manner. A necessary component of this interaction is communication. To this end, assessments of QL have included open-ended items as a means of including communicative aspects of QL. The present study sought to examine whether such open-ended items typically measured aspects of quantitative communication, as compared to mathematical communication, or mathematical skills. We focused on public-released items and rubrics from four of the most widely referenced assessments: the Third International Mathematics and Science Study (TIMSS-95: the National Adult Literacy Survey (NALS; now the National Assessment of Adult Literacy, NAAL in 1985 and 1992, the International Adult Literacy Skills (IALS beginning in 1994; and the Program for International Student Assessment (PISA beginning in 2000. We found that open-ended item rubrics in these QL assessments showed a strong tendency to assess answer-only responses. Therefore, while some open-ended items may have required certain levels of quantitative reasoning to find a solution, it is the solution rather than the reasoning that was often assessed.

  18. OPEN-ENDED APPROACH: AN EFFORT IN CULTIVATING STUDENTS’ MATHEMATICAL CREATIVE THINKING ABILITY AND SELF-ESTEEM IN MATHEMATICS

    Directory of Open Access Journals (Sweden)

    Abdul Fatah

    2016-01-01

    Full Text Available The present study aims at examining the use of open-ended approach in cultivating senior high school students’ mathematical creative thinking ability (MCTA and self-esteem (SE in mathematics viewed from school category. The subjects of this research were the students grade XI at three schools; high, middle and low category in Kota Serang, Banten Province. In every school category, two classes were chosen; one class was the experimental group which was taught by open-ended approach, while another class was a control group which was taught by conventional way. This quasi-experimental research employed MCTA test and SE in mathematics scale as the instruments. In general, the research result shows that the MCTA improvement and SE level of the students who are taught by open-ended approach is better than those who are taught conventionally. The results of students’ MCTA and SE viewed from school category will be further discussed.Keywords: mathematical creative thinking ability, self-esteem, open-ended approach DOI: http://dx.doi.org/10.22342/jme.7.1.2813.9-18

  19. Physics 30 Program Machine-Scorable Open-Ended Questions: Unit 2: Electric and Magnetic Forces. Diploma Examinations Program.

    Science.gov (United States)

    Alberta Dept. of Education, Edmonton.

    This document outlines the use of machine-scorable open-ended questions for the evaluation of Physics 30 in Alberta. Contents include: (1) an introduction to the questions; (2) sample instruction sheet; (3) fifteen sample items; (4) item information including the key, difficulty, and source of each item; (5) solutions to items having multiple…

  20. Does the sequence of data collection influence participants' responses to closed and open-ended questions? A methodological study.

    Science.gov (United States)

    Covell, Christine L; Sidani, Souraya; Ritchie, Judith A

    2012-06-01

    The sequence used for collecting quantitative and qualitative data in concurrent mixed-methods research may influence participants' responses. Empirical evidence is needed to determine if the order of data collection in concurrent mixed methods research biases participants' responses to closed and open-ended questions. To examine the influence of the quantitative-qualitative sequence on responses to closed and open-ended questions when assessing the same variables or aspects of a phenomenon simultaneously within the same study phase. A descriptive cross-sectional, concurrent mixed-methods design was used to collect quantitative (survey) and qualitative (interview) data. The setting was a large multi-site health care centre in Canada. A convenience sample of 50 registered nurses was selected and participated in the study. Participants were randomly assigned to one of two sequences for data collection, quantitative-qualitative or qualitative-quantitative. Independent t-tests were performed to compare the two groups' responses to the survey items. Directed content analysis was used to compare the participants' responses to the interview questions. The sequence of data collection did not greatly affect the participants' responses to the closed-ended questions (survey items) or the open-ended questions (interview questions). The sequencing of data collection, when using both survey and semi-structured interviews, may not bias participants' responses to closed or open-ended questions. Additional research is required to confirm these findings. Copyright © 2011 Elsevier Ltd. All rights reserved.

  1. Nanoscopic dynamics of bicontinous microemulsions: effect of membrane associated protein.

    Science.gov (United States)

    Sharma, V K; Hayes, Douglas G; Urban, Volker S; O'Neill, Hugh M; Tyagi, M; Mamontov, E

    2017-07-19

    Bicontinous microemulsions (BμE) generally consist of nanodomains formed by surfactant in a mixture of water and oil at nearly equal proportions and are potential candidates for the solubilization and purification of membrane proteins. Here we present the first time report of nanoscopic dynamics of surfactant monolayers within BμEs formed by the anionic surfactant sodium dodecyl sulfate (SDS) measured on the nanosecond to picosecond time scale using quasielastic neutron scattering (QENS). BμEs investigated herein consisted of middle phases isolated from Winsor-III microemulsion systems that were formed by mixing aqueous and oil solutions under optimal conditions. QENS data indicates that surfactants undergo two distinct motions, namely (i) lateral motion along the surface of the oil nanodomains and (ii) localized internal motion. Lateral motion can be described using a continuous diffusion model, from which the lateral diffusion coefficient is obtained. Internal motion of surfactant is described using a model which assumes that a fraction of the surfactants' hydrogens undergoes localized translational diffusion that could be considered confined within a spherical volume. The effect of cytochrome c, an archetypal membrane-associated protein known to strongly partition near the surfactant head groups in BμEs (a trend supported by small-angle X-ray scattering [SAXS] analysis), on the dynamics of BμE has also been investigated. QENS results demonstrated that cytochrome c significantly hindered both the lateral and the internal motions of surfactant. The lateral motion was more strongly affected: a reduction of the lateral diffusion coefficient by 33% was measured. This change is mainly attributable to the strong association of cytochrome c with oppositely charged SDS. In contrast, analysis of SAXS data suggested that thermal fluctuations (for a longer length and slower time scale compared to QENS) were increased upon incorporation of cytochrome c. This study

  2. Formation of Kinetically Trapped Nanoscopic Unilamellar Vesicles from Metastable Nanodiscs

    Energy Technology Data Exchange (ETDEWEB)

    Nieh, Mu-Ping [Univ. of Connecticut, Storrs, CT (United States). Inst. of Materials Science, Dept. of Chemical, Materials & Biomolecular Engineering; Dolinar, Paul [Univ. of Ottawa, ON (Canada); Kucerka, Norbert [National Research Council, Chalk River, ON (Canada). Chalk River Lab., Canadian Neutron Beam Centre; Comenius Univ., Bratislava (Slovakia). Dept. of Physical Chemistry of Drugs; Kline, Steven R. [National Inst. of Standards and Technology (NIST), Gaithersburg, MD (United States); Debeer-Schmitt, Lisa M. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Neutron Scattering Science Division; Littrell, Kenneth C. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Neutron Scattering Science Division; Katsaras, John [National Research Council, Chalk River, ON (Canada). Chalk River Lab., Canadian Neutron Beam Centre; Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Neutron Scattering Science Division; Brock Univ., St. Catharines, ON (Canada). Dept. of Physics; Univ. of Guelph, ON (Canada). Guelph-Waterloo Physics Inst.

    2011-09-27

    Zwitterionic long-chain lipids (e.g., dimyristoyl phosphatidylcholine, DMPC) spontaneously form onion-like, thermodynamically stable structures in aqueous solutions (commonly known as multilamellar vesicles, or MLVs). It has also been reported that the addition of zwitterionic short-chain (i.e., dihexanoyl phosphatidylcholine, DHPC) and charged long-chain (i.e., dimyristoyl phosphatidylglycerol, DMPG) lipids to zwitterionic long-chain lipid solutions results in the formation of unilamellar vesicles (ULVs). Here, we report a kinetic study on lipid mixtures composed of DMPC, DHPC, and DMPG. Two membrane charge densities (i.e., [DMPG]/[DMPC] = 0.01 and 0.001) and two solution salinities (i.e., [NaCl] = 0 and 0.2 M) are investigated. Upon dilution of the high-concentration samples at 50 °C, thermodynamically stable MLVs are formed, in the case of both weakly charged and high salinity solution mixtures, implying that the electrostatic interactions between bilayers are insufficient to cause MLVs to unbind. Importantly, in the case of these samples small angle neutron scattering (SANS) data show that, initially, nanodiscs (also known as bicelles) or bilayered ribbons form at low temperatures (i.e., 10 °C), but transform into uniform size, nanoscopic ULVs after incubation at 10 °C for 20 h, indicating that the nanodisc is a metastable structure. The instability of nanodiscs may be attributed to low membrane rigidity due to a reduced charge density and high salinity. Moreover, the uniform-sized ULVs persist even after being heated to 50 °C, where thermodynamically stable MLVs are observed. This result clearly demonstrates that these ULVs are kinetically trapped, and that the mechanical properties (e.g., bending rigidity) of 10 C nanodiscs favor the formation of nanoscopic ULVs over that of MLVs. From a practical point of view, this method of forming uniform-sized ULVs may lend itself to their mass production, thus making them economically feasible for medical

  3. Formation of Kinetically Trapped Nanoscopic Unilamellar Vesicles from Metastable Nanodiscs

    International Nuclear Information System (INIS)

    Nieh, Mu-Ping; Dolinar, Paul; Kucerka, Norbert; Kline, Steven R.; Debeer-Schmitt, Lisa M.; Littrell, Ken; Katsaras, John

    2011-01-01

    Zwitterionic long-chain lipids (e.g., dimyristoyl phosphatidylcholine, DMPC) spontaneously form onion-like, thermodynamically stable structures in aqueous solutions (commonly known as multilamellar vesicles, or MLVs). It has also been reported that the addition of zwitterionic short-chain (i.e., dihexanoyl phosphatidylcholine, DHPC) and charged long-chain (i.e., dimyristoyl phosphatidylglycerol, DMPG) lipids to zwitterionic long-chain lipid solutions results in the formation of unilamellar vesicles (ULVs). Here, we report a kinetic study on lipid mixtures composed of DMPC, DHPC, and DMPG. Two membrane charge densities (i.e., (DMPG)/(DMPC) = 0.01 and 0.001) and two solution salinities (i.e., (NaCl) = 0 and 0.2 M) are investigated. Upon dilution of the high-concentration samples at 50 C, thermodynamically stable MLVs are formed, in the case of both weakly charged and high salinity solution mixtures, implying that the electrostatic interactions between bilayers are insufficient to cause MLVs to unbind. Importantly, in the case of these samples small angle neutron scattering (SANS) data show that, initially, nanodiscs (also known as bicelles) or bilayered ribbons form at low temperatures (i.e., 10 C), but transform into uniform size, nanoscopic ULVs after incubation at 10 C for 20 h, indicating that the nanodisc is a metastable structure. The instability of nanodiscs may be attributed to low membrane rigidity due to a reduced charge density and high salinity. Moreover, the uniform-sized ULVs persist even after being heated to 50 C, where thermodynamically stable MLVs are observed. This result clearly demonstrates that these ULVs are kinetically trapped, and that the mechanical properties (e.g., bending rigidity) of 10 C nanodiscs favor the formation of nanoscopic ULVs over that of MLVs. From a practical point of view, this method of forming uniform-sized ULVs may lend itself to their mass production, thus making them economically feasible for medical applications that

  4. Should essays and other "open-ended"-type questions retain a place in written summative assessment in clinical medicine?

    Science.gov (United States)

    Hift, Richard J

    2014-11-28

    Written assessments fall into two classes: constructed-response or open-ended questions, such as the essay and a number of variants of the short-answer question, and selected-response or closed-ended questions; typically in the form of multiple-choice. It is widely believed that constructed response written questions test higher order cognitive processes in a manner that multiple-choice questions cannot, and consequently have higher validity. An extensive review of the literature suggests that in summative assessment neither premise is evidence-based. Well-structured open-ended and multiple-choice questions appear equivalent in their ability to assess higher cognitive functions, and performance in multiple-choice assessments may correlate more highly than the open-ended format with competence demonstrated in clinical practice following graduation. Studies of construct validity suggest that both formats measure essentially the same dimension, at least in mathematics, the physical sciences, biology and medicine. The persistence of the open-ended format in summative assessment may be due to the intuitive appeal of the belief that synthesising an answer to an open-ended question must be both more cognitively taxing and similar to actual experience than is selecting a correct response. I suggest that cognitive-constructivist learning theory would predict that a well-constructed context-rich multiple-choice item represents a complex problem-solving exercise which activates a sequence of cognitive processes which closely parallel those required in clinical practice, hence explaining the high validity of the multiple-choice format. The evidence does not support the proposition that the open-ended assessment format is superior to the multiple-choice format, at least in exit-level summative assessment, in terms of either its ability to test higher-order cognitive functioning or its validity. This is explicable using a theory of mental models, which might predict that the

  5. Learning Autonomy in Two or Three Steps: Linking Motivation, Authority, and Agency, with Open-ended Development

    Directory of Open Access Journals (Sweden)

    Tjeerd C Andringa

    2013-10-01

    Full Text Available In this paper we connect open-ended development, authority, agency, and motivation through 1 an analysis of the demands of existing in a complex world and 2 environmental appraisal in terms of affordance content and the complexity to select appropriate behavior. We do this by identifying a coherent core from a wide range of contributing fields. Open-ended development is a structured three-step process in which the agent first learns to master the body and then aims to make the mind into a reliable tool. Preconditioned on success in step two, step three aims to effectively co-create an optimal living environment. We argue that these steps correspond to right-left-right hemispheric dominance, where the left hemisphere specializes in control and the right hemisphere in exploration. Control (e.g., problem solving requires a closed and stable world that must be maintained by external authorities or, in step three, by the right hemisphere acting as internal authority. The three-step progression therefore corresponds to increasing autonomy and agency.Depending on how we appraise the environment, we formulate four qualitatively different motivational states: submission, control, exploration, and consolidation. Each of these four motivational states has associated reward signals of which the last three — successful control, discovery of novelty, and establishing new relations — form an open-ended development loop that, the more it is executed, helps the agent to become progressively more agentic and more able to co-create a pleasant-to-live-in world. We conclude that for autonomy to arise, the agent must exist in a (broad transition region between order and disorder in which both danger and opportunity (and with that open-ended development and motivation are defined. We conclude that a research agenda for artificial cognitive system research should include open-ended development through intrinsic motivations and ascribing more prominence to right

  6. Learning autonomy in two or three steps: linking open-ended development, authority, and agency to motivation.

    Science.gov (United States)

    Andringa, Tjeerd C; van den Bosch, Kirsten A; Vlaskamp, Carla

    2013-01-01

    In this paper we connect open-ended development, authority, agency, and motivation through (1) an analysis of the demands of existing in a complex world and (2) environmental appraisal in terms of affordance content and the complexity to select appropriate behavior. We do this by identifying a coherent core from a wide range of contributing fields. Open-ended development is a structured three-step process in which the agent first learns to master the body and then aims to make the mind into a reliable tool. Preconditioned on success in step two, step three aims to effectively co-create an optimal living environment. We argue that these steps correspond to right-left-right hemispheric dominance, where the left hemisphere specializes in control and the right hemisphere in exploration. Control (e.g., problem solving) requires a closed and stable world that must be maintained by external authorities or, in step three, by the right hemisphere acting as internal authority. The three-step progression therefore corresponds to increasing autonomy and agency. Depending on how we appraise the environment, we formulate four qualitatively different motivational states: submission, control, exploration, and consolidation. Each of these four motivational states has associated reward signals of which the last three-successful control, discovery of novelty, and establishing new relations-form an open-ended development loop that, the more it is executed, helps the agent to become progressively more agentic and more able to co-create a pleasant-to-live-in world. We conclude that for autonomy to arise, the agent must exist in a (broad) transition region between order and disorder in which both danger and opportunity (and with that open-ended development and motivation) are defined. We conclude that a research agenda for artificial cognitive system research should include open-ended development through intrinsic motivations and ascribing more prominence to right hemispheric strengths.

  7. Learning autonomy in two or three steps: linking open-ended development, authority, and agency to motivation

    Science.gov (United States)

    Andringa, Tjeerd C.; van den Bosch, Kirsten A.; Vlaskamp, Carla

    2013-01-01

    In this paper we connect open-ended development, authority, agency, and motivation through (1) an analysis of the demands of existing in a complex world and (2) environmental appraisal in terms of affordance content and the complexity to select appropriate behavior. We do this by identifying a coherent core from a wide range of contributing fields. Open-ended development is a structured three-step process in which the agent first learns to master the body and then aims to make the mind into a reliable tool. Preconditioned on success in step two, step three aims to effectively co-create an optimal living environment. We argue that these steps correspond to right-left-right hemispheric dominance, where the left hemisphere specializes in control and the right hemisphere in exploration. Control (e.g., problem solving) requires a closed and stable world that must be maintained by external authorities or, in step three, by the right hemisphere acting as internal authority. The three-step progression therefore corresponds to increasing autonomy and agency. Depending on how we appraise the environment, we formulate four qualitatively different motivational states: submission, control, exploration, and consolidation. Each of these four motivational states has associated reward signals of which the last three—successful control, discovery of novelty, and establishing new relations—form an open-ended development loop that, the more it is executed, helps the agent to become progressively more agentic and more able to co-create a pleasant-to-live-in world. We conclude that for autonomy to arise, the agent must exist in a (broad) transition region between order and disorder in which both danger and opportunity (and with that open-ended development and motivation) are defined. We conclude that a research agenda for artificial cognitive system research should include open-ended development through intrinsic motivations and ascribing more prominence to right hemispheric

  8. When familiar social partners are selected in open-ended situations: further tests of the socioemotional selectivity theory.

    Science.gov (United States)

    Dudley, Nikki M; Multhaup, Kristi S

    2005-01-01

    Socioemotional selectivity theory (SST; Carstensen, 1995, Current Directions in Psychological Science, 4, 151-156) predicts that novel social partners are preferred in open-ended situations, whereas familiar social partners are preferred in future-limited situations. The authors attempted to generalize past research to new familiar and novel partner options. Studies 1 (N=144; undergraduates, community-dwelling adults ages 65 to 95) and 2 (N=336 community-dwelling participants ages 11 to 89) indicated that young and older participants in a future-limited situation preferred familiar partners. However, with different social partner options than have been used in previous research, young participants in an open-ended situation also preferred a familiar partner, contrary to the predictions of SST.

  9. Design of a Short/Open-Ended Slot Antenna with Capacitive Coupling Feed Strips for Hepta-Band Mobile Application

    Directory of Open Access Journals (Sweden)

    Kyoseung Keum

    2018-01-01

    Full Text Available In this paper, a planar printed hybrid short/open-ended slot antenna with capacitive coupling feed strips is proposed for hepta-band mobile applications. The proposed antenna is comprised of a slotted ground plane on the top plane and two capacitive coupling feed strips with a chip inductor on the bottom plane. At the low frequency band, the short-ended long slot fed by strip 1 generates its half-wavelength resonance mode, whereas the T-shaped open ended slot fed by strip 2 generates its quarter-wavelength resonance mode for the high frequency band. The antenna provides a wide bandwidth covering GSM850/GSM900/DCS/PCS/UMTS/LTE2300/LTE2500 operation bands. Moreover, the antenna occupies a small volume of 15 mm × 50 mm × 1 mm. The operating principle of the proposed antenna and the simulation/measurement results are presented and discussed.

  10. The dark and the bright side of liquidity risks: evidence from open-end real estate funds in Germany

    OpenAIRE

    Fecht, Falko; Wedow, Michael

    2009-01-01

    We use a unique and comprehensive data set on open-end real estate funds in Germany to study a liquidity crisis that hit this industry between 2005 and 2006. Since this industry is comparably unregulated our data set permits us to contrast competing explanations of liquidity crisis. We find that fundamental factors matter for the liquidity outflow in normal times. During the crisis, however, they do not play a role. During the panic only strategic complementarities drive withdrawals. Furtherm...

  11. A Possible Link between Supra-Second Open-Ended Timing Sensitivity and Obsessive-Compulsive Tendencies.

    Science.gov (United States)

    Gilaie-Dotan, Sharon; Ashkenazi, Hamutal; Dar, Reuven

    2016-01-01

    One of the main characteristics of obsessive-compulsive disorder (OCD) is the persistent feeling of uncertainty, affecting many domains of actions and feelings. It was recently hypothesized that OCD uncertainty is related to attenuated access to internal states. As supra-second timing is associated with bodily and interoceptive awareness, we examined whether supra-second timing would be associated with OC tendencies. We measured supra-second (~9 s) and sub-second (~450 ms) timing along with control non-temporal perceptual tasks in a group of 60 university students. Supra-second timing was measured either with fixed criterion tasks requiring to temporally discriminate between two predefined fixed interval durations (9 vs. 9.9 s), or with an open-ended task requiring to discriminate between 9 s and longer intervals which were of varying durations that were not a priori known to the participants. The open-ended task employed an adaptive Bayesian procedure that efficiently estimated the duration difference required to discriminate 9 s from longer intervals. We also assessed symptoms of OCD, depression, and anxiety. Open-ended supra-second temporal sensitivity was correlated with OC tendencies, as predicted (even after controlling for depression and anxiety), whereas the other tasks were not. Higher OC tendencies were associated with lower timing sensitivity to 9 s intervals such that participants with higher OC tendency scores required longer interval differences to discriminate 9 s from longer intervals. While these results need to be substantiated in future research, they suggest that open-ended timing tasks, as those encountered in real-life (e.g., estimating how long it would take to complete a task), might be adversely affected in OCD.

  12. Ultralow field emission from thinned, open-ended, and defected carbon nanotubes by using microwave hydrogen plasma processing

    Energy Technology Data Exchange (ETDEWEB)

    Deng, Jian-Hua, E-mail: jhdeng1983@163.com [College of Physics and Materials Science, Tianjin Normal University, Tianjin 300387 (China); Cheng, Lin; Wang, Fan-Jie; Yu, Bin; Li, Guo-Zheng; Li, De-Jun [College of Physics and Materials Science, Tianjin Normal University, Tianjin 300387 (China); Cheng, Guo-An [Key Laboratory of Beam Technology and Material Modification of Ministry of Education, Beijing Normal University, Beijing 100875 (China)

    2015-01-01

    Graphical abstract: Thinned, open-ended, and defected carbon nanotubes were prepared by using hydrogen plasma processing. The processed carbon nanotubes have far better field emission performance than that of the pristine ones. - Highlights: • CVD prepared CNT arrays were processed by microwave hydrogen plasma. • Thinned, open-ended, and defected CNTs were obtained. • Processed CNTs have far better field emission performance than the pristine ones. • Processed CNTs have applicable emission stability after being perfectly aged. - Abstract: Ultralow field emission is achieved from carbon nanotubes (CNTs) by using microwave hydrogen plasma processing. After the processing, typical capped CNT tips are removed, with thinned, open-ended, and defected CNTs left. Structural analyses indicate that the processed CNTs have more SP{sup 3}-hybridized defects as compared to the pristine ones. The morphology of CNTs can be readily controlled by adjusting microwave powers, which change the shape of CNTs by means of hydrogen plasma etching. Processed CNTs with optimal morphology are found to have an ultralow turn-on field of 0.566 V/μm and threshold field of 0.896 V/μm, much better than 0.948 and 1.559 V/μm of the as-grown CNTs, respectively. This improved FE performance is ascribed to the structural changes of CNTs after the processing. The thinned and open-ended shape of CNTs can facilitate electron tunneling through barriers and additionally, the increased defects at tube walls can serve as new active emission sites. Furthermore, our plasma processed CNTs exhibit excellent field emission stability at a large emission current density of 10.36 mA/cm{sup 2} after being perfectly aged, showing promising prospects in applications as high-performance vacuum electron sources.

  13. FIXED ASSETS WITH AN OPEN-ENDED USEFUL LIFE AS A NEW OBJECT OF ACCOUNTING IN THE SHIP REPAIR INDUSTRY

    Directory of Open Access Journals (Sweden)

    Olga Zharikova

    2015-09-01

    Full Text Available The industry-specific factors that contribute to the allocation of a new object of accounting in property, plant and equipment of the ship repair industry organizations are revealed. Specificity the salvaging operation of hydraulic structures, which affect the organization and methodology of objects` accounting, is described. The definition of «fixed assets with an open-ended useful life» is proposed.

  14. Nonlocal continuum-based modeling of mechanical characteristics of nanoscopic structures

    Energy Technology Data Exchange (ETDEWEB)

    Rafii-Tabar, Hashem, E-mail: rafii-tabar@nano.ipm.ac.ir [Department of Medical Physics and Biomedical Engineering, Faculty of Medicine, Shahid Beheshti University of Medical Sciences, Tehran (Iran, Islamic Republic of); Ghavanloo, Esmaeal, E-mail: ghavanloo@shirazu.ac.ir [School of Mechanical Engineering, Shiraz University, Shiraz 71963-16548 (Iran, Islamic Republic of); Fazelzadeh, S. Ahmad [School of Mechanical Engineering, Shiraz University, Shiraz 71963-16548 (Iran, Islamic Republic of)

    2016-06-06

    Insight into the mechanical characteristics of nanoscopic structures is of fundamental interest and indeed poses a great challenge to the research communities around the world. These structures are ultra fine in size and consequently performing standard experiments to measure their various properties is an extremely difficult and expensive endeavor. Hence, to predict the mechanical characteristics of the nanoscopic structures, different theoretical models, numerical modeling techniques, and computer-based simulation methods have been developed. Among several proposed approaches, the nonlocal continuum-based modeling is of particular significance because the results obtained from this modeling for different nanoscopic structures are in very good agreement with the data obtained from both experimental and atomistic-based studies. A review of the essentials of this model together with its applications is presented here. Our paper is a self contained presentation of the nonlocal elasticity theory and contains the analysis of the recent works employing this model within the field of nanoscopic structures. In this review, the concepts from both the classical (local) and the nonlocal elasticity theories are presented and their applications to static and dynamic behavior of nanoscopic structures with various morphologies are discussed. We first introduce the various nanoscopic structures, both carbon-based and non carbon-based types, and then after a brief review of the definitions and concepts from classical elasticity theory, and the basic assumptions underlying size-dependent continuum theories, the mathematical details of the nonlocal elasticity theory are presented. A comprehensive discussion on the nonlocal version of the beam, the plate and the shell theories that are employed in modeling of the mechanical properties and behavior of nanoscopic structures is then provided. Next, an overview of the current literature discussing the application of the nonlocal models

  15. Nonlocal continuum-based modeling of mechanical characteristics of nanoscopic structures

    International Nuclear Information System (INIS)

    Rafii-Tabar, Hashem; Ghavanloo, Esmaeal; Fazelzadeh, S. Ahmad

    2016-01-01

    Insight into the mechanical characteristics of nanoscopic structures is of fundamental interest and indeed poses a great challenge to the research communities around the world. These structures are ultra fine in size and consequently performing standard experiments to measure their various properties is an extremely difficult and expensive endeavor. Hence, to predict the mechanical characteristics of the nanoscopic structures, different theoretical models, numerical modeling techniques, and computer-based simulation methods have been developed. Among several proposed approaches, the nonlocal continuum-based modeling is of particular significance because the results obtained from this modeling for different nanoscopic structures are in very good agreement with the data obtained from both experimental and atomistic-based studies. A review of the essentials of this model together with its applications is presented here. Our paper is a self contained presentation of the nonlocal elasticity theory and contains the analysis of the recent works employing this model within the field of nanoscopic structures. In this review, the concepts from both the classical (local) and the nonlocal elasticity theories are presented and their applications to static and dynamic behavior of nanoscopic structures with various morphologies are discussed. We first introduce the various nanoscopic structures, both carbon-based and non carbon-based types, and then after a brief review of the definitions and concepts from classical elasticity theory, and the basic assumptions underlying size-dependent continuum theories, the mathematical details of the nonlocal elasticity theory are presented. A comprehensive discussion on the nonlocal version of the beam, the plate and the shell theories that are employed in modeling of the mechanical properties and behavior of nanoscopic structures is then provided. Next, an overview of the current literature discussing the application of the nonlocal models

  16. How do open-ended problems promote mathematical creativity? A reflection of bare mathematics problem and contextual problem

    Science.gov (United States)

    Wijaya, A.

    2018-03-01

    Creativity is often seen as one of the fundamental aspects of character education. As one of the 21st century skills, creativity has also been considered as an important goal of education across the world. This paper reports a study on promoting mathematical creativity through the use of open-ended mathematics problems. A total of 53 undergraduate students participated in the study. These students worked on open-ended problems in two types, i.e. bare mathematics problem and contextual problem. The contextual problem was presented in the form of paper-based and Geogebra-based. The students’ works were analysed qualitatively in order to describe how students’ mathematical creativity developed. It was found that the open-ended problems successfully promote students’ creativity as indicated by various solutions or strategies that were used by students to solve the problems. The analysis of students’ works show that students’ creativity developed through three kinds of exploration, i. e. (1) exploration of contexts, (2) exploration of software features, and (3) exploration of mathematics concepts. The use of metacognitive questioning was found to be helpful to develop the first two explorations into mathematical exploration.

  17. EFEKTIVITAS PEMBELAJARAN MATEMATIKA MENGGUNAKAN METODE TPS (THINK-PAIR-SHARE BERBASIS OPEN-ENDED-PROBLEM TERHADAP KREATIVITAS BELAJAR SISWA

    Directory of Open Access Journals (Sweden)

    Sri Hudia Rohmatin

    2015-08-01

    Full Text Available This study was aimed at finding out whether or not Open-Ended-Problem Based TPS Method was effective on student’s mathematics learning creativity. The type of this research was quasi-eksperimental with one-group pretet posttest desaign. The sample of this research was 33 students. Instrument in form of 4 essay that was valid and reliable. Normality testing with Chi-kuadrat and homogeneity testing with Barlett-test  while hypotesis testing with paramteric statistical analysis t-test. Based on the data analysis average pre test was 44 and post test was 64. The results of the normality testing pre-test group obtained x2count < x2tabel or 4.452  < 11.070 and post test group obtained x2count < x2tabel or 5,946 < 11.070. Data homogeneity testing results obtained x2count < x2tabel 2,484  < 3,841. The results of hypothesis testing data was obtained tcount > ttabel or 12,317 > 2,001. Based on the test results concluded that the hypothesis Ho was rejected and Ha accepted. To sum up, Open-Ended-Problem-Based TPS was significantly effective on student’s mathematics learning creativity. Key words: effectiveness, TPS method, open-ended-problem, students creativity DOI: http://dx.doi.org/10.22342/jpm.9.2.2085.178 - 187

  18. Translating Answers to Open-Ended Survey Questions in Cross-Cultural Research: A Case Study on the Interplay between Translation, Coding, and Analysis

    Science.gov (United States)

    Behr, Dorothée

    2015-01-01

    Open-ended probing questions in cross-cultural surveys help uncover equivalence problems in cross-cultural survey research. For languages that a project team does not understand, probe answers need to be translated into a common project language. This article presents a case study on translating open-ended, that is, narrative answers. It describes…

  19. 17 CFR 270.6c-10 - Exemption for certain open-end management investment companies to impose deferred sales loads.

    Science.gov (United States)

    2010-04-01

    ... management investment companies to impose deferred sales loads. 270.6c-10 Section 270.6c-10 Commodity and... ACT OF 1940 § 270.6c-10 Exemption for certain open-end management investment companies to impose... purposes of this section: (1) Company means a registered open-end management investment company, other than...

  20. Contribution of Adsorbed Protein Films to Nanoscopic Vibrations Exhibited by Bacteria Adhering through Ligand-Receptor Bonds

    NARCIS (Netherlands)

    Song, Lei; Sjollema, Jelmer; Norde, Willem; Busscher, Henk J.; van der Mei, Henny C.

    2015-01-01

    Bacteria adhering to surfaces exhibit nanoscopic vibrations that depend on the viscoelasticity of the bond. The quantification of the nanoscopic vibrations of bacteria adhering to surfaces provides new opportunities to better understand the properties of the bond through which bacteria adhere and

  1. Educational Implication For Adopting Open-Ended Response Systems In Higher Education The Scenario Of Wa Polytechnic Ghana.

    Directory of Open Access Journals (Sweden)

    Nicholas A. Tetteh

    2015-08-01

    Full Text Available Teaching and learning is fundamentally a two-way affair the teacher transferring knowledge and the learner making meaning from the knowledge. Teaching becomes complete when the learner acquires the knowledge transferred and applies it appropriately to real life situations. However in Ghana teaching and learning has undergone a lot of alteration coupled with both negative and positive effects. In Wa Polytechnic teaching and learning has seen little or no improvement with regards to information and communication Technology ICT making it difficult for students to acquire 21st century skills and be part of the digitally connected ecosystem. Active classroom participation and engagement information sharing communication collaboration coupled with large class sizes have been a problem for teachers and students in Wa Polytechnic hence the need to conduct a study to identify productive solutions that enhance students participation and engagement in the classroom. The study investigates the role of ICT in augmenting active participation and engagement of students in the classroom via open-ended response systems. The study was conducted using Educational Design Research EDR methods. A critical analysis was done by studying the responses of the respondents which identified three forms of students classroom participation and engagement verbal classroom participation non-verbal classroom participation and after classroom teaching and learning activities. Smart phones laptop tablet iPad and regular cellular phone were the predominant devices used by students for other purpose rather than teacher-led class activities. When students were made to actively participate in the classroom using the devices as open-ended response system students engagement and their ability to contribute during lectures appreciated comparatively. It was however evident that open-ended response system was effective tool to manage large class sizes as students who were timid could

  2. The Effect of an Open-Ended Design Experience on Student Achievement in an Engineering Laboratory Course

    Directory of Open Access Journals (Sweden)

    Matthew Cullin

    2017-11-01

    Full Text Available This study explores the effect of incorporating an Open-Ended Design Experience (OEDE into an undergraduate materials science laboratory taken by third-year mechanical engineering students. The focus of the OEDE was carbon fiber reinforced plastics and sandwich structures. The results indicate that the incorporation of OEDE’s in laboratory courses produces significant benefits in terms of student engagement, participation, and perception of competence. In addition, the OEDE was found to enhance students’ ability to apply related concepts as compared to non-OEDE lab activities. The authors conclude that the incorporation of OEDE’s can increase the effectiveness of engineering laboratory courses.

  3. Mudaraba-Venture Capital Closed-end Mutual Funds and Mudaraba-Venture Capital Open-end Mutual Funds

    OpenAIRE

    Halil Ibrahim Bulut

    2008-01-01

    The important part of this study attempts to explain that both venture capital and interest-free financing are based on similar ground, if not the same. Two new models called Mudaraba-Venture Capital Closed-End Mutual Funds and Mudaraba-Venture Capital Open-End Mutual Funds, based on both the similarities and the needs of financial innovation in the interest-free financing system, are detailed. It is believed that the development of these two models could make some improvements not only in th...

  4. A perspective on the interfacial properties of nanoscopic liquid drops

    International Nuclear Information System (INIS)

    Malijevský, Alexandr; Jackson, George

    2012-01-01

    The structural and interfacial properties of nanoscopic liquid drops are assessed by means of mechanical, thermodynamical, and statistical mechanical approaches that are discussed in detail, including original developments at both the macroscopic level and the microscopic level of density functional theory (DFT). With a novel analysis we show that a purely macroscopic (static) mechanical treatment can lead to a qualitatively reasonable description of the surface tension and the Tolman length of a liquid drop; the latter parameter, which characterizes the curvature dependence of the tension, is found to be negative and has a magnitude of about a half of the molecular dimension. A mechanical slant cannot, however, be considered satisfactory for small finite-size systems where fluctuation effects are significant. From the opposite perspective, a curvature expansion of the macroscopic thermodynamic properties (density and chemical potential) is then used to demonstrate that a purely thermodynamic approach of this type cannot in itself correctly account for the curvature correction of the surface tension of liquid drops. We emphasize that any approach, e.g., classical nucleation theory, which is based on a purely macroscopic viewpoint, does not lead to a reliable representation when the radius of the drop becomes microscopic. The description of the enhanced inhomogeneity exhibited by small drops (particularly in the dense interior) necessitates a treatment at the molecular level to account for finite-size and surface effects correctly. The so-called mechanical route, which corresponds to a molecular-level extension of the macroscopic theory of elasticity and is particularly popular in molecular dynamics simulation, also appears to be unreliable due to the inherent ambiguity in the definition of the microscopic pressure tensor, an observation which has been known for decades but is frequently ignored. The union of the theory of capillarity (developed in the nineteenth

  5. Use of open-ended problems as the basis for the mathematical creativity growth disclosure of student

    Science.gov (United States)

    Suyitno, A.; Suyitno, H.; Rochmad; Dwijanto

    2018-03-01

    Mathematical creativity is the essence of learning in mathematics. However, mathematical creativity had not yet grown among students. Means there was a gap between needs and reality. This gap must be bridged through by scientific studies, and there were novelty findings, namely the discovery of stages to cultivate of Mathematical Creativity. The problem formulation: How to use of open-ended problems as the basis for the mathematical creativity growth disclosure of student? The goal was to use of open issues as the basis for the mathematical creativity growth disclosure of student. Research method with a qualitative approach. After data was collected then activity in data analysis, include data reduction, data presentation, data interpretation, and conclusion/verification. The results of the research: After the learning by applying the modification of RTTW learning model, then the students were trained to do the open-ended problems and by looking at the UTS and UAS values then qualitatively the results: (1) There was a significant increase of the student's final score. (2) The category of the growth of mathematical creativity of students, the Very Good there were three students, the Good there were six students, There were 17 students, and there were six students. The validation of these results was reinforced by interviews and triangulation. (3) Stage to cultivate mathematical creativity: lecturers should need to provide inputs on student work; Apply an appropriate learning model, and train students to work on the continuing problems.

  6. Fuel cell integral bundle assembly including ceramic open end seal and vertical and horizontal thermal expansion control

    Science.gov (United States)

    Zafred, Paolo R [Murrysville, PA; Gillett, James E [Greensburg, PA

    2012-04-24

    A plurality of integral bundle assemblies contain a top portion with an inlet fuel plenum and a bottom portion containing a base support, the base supports a dense, ceramic air exhaust manifold having four supporting legs, the manifold is below and connects to air feed tubes located in a recuperator zone, the air feed tubes passing into the center of inverted, tubular, elongated, hollow electrically connected solid oxide fuel cells having an open end above a combustion zone into which the air feed tubes pass and a closed end near the inlet fuel plenum, where the open end of the fuel cells rest upon and within a separate combination ceramic seal and bundle support contained in a ceramic support casting, where at least one flexible cushion ceramic band seal located between the recuperator and fuel cells protects and controls horizontal thermal expansion, and where the fuel cells operate in the fuel cell mode and where the base support and bottom ceramic air exhaust manifolds carry from 85% to all of the weight of the generator.

  7. A Rectangular Ring, Open-Ended Monopole Antenna with Two Symmetric Strips for WLAN and WiMAX Applications

    Directory of Open Access Journals (Sweden)

    Joong-Han Yoon

    2013-01-01

    Full Text Available A triple-band rectangular ring, open-ended monopole antenna with symmetric L strips for wireless local area network (WLAN/Worldwide Interoperability of Microwave Access (WiMAX applications is proposed. The proposed antenna consists of two symmetric folded arms and L strips. Based on the concept, a prototype of the proposed triple antenna has been designed, fabricated, and tested. The numerical and experimental results demonstrated that the proposed antenna satisfied the −10 dB impedance bandwidth requirement while simultaneously covering the WLAN and WiMAX bands. Furthermore, this paper presented and discussed the 2D radiation patterns and 3D gains according to the results of the experiment. The proposed antenna’s peak gain varied between 2.17 and 4.93 dBi, and its average gain varied between −2.97 and −0.53 dBi.

  8. Experimental Investigation of Damage and Fracture Mechanisms Controlling the Performance of Full Aperture Easy Open Ends for Food Containers

    Science.gov (United States)

    Taylor, D. L. P.; Nagy, G. T.; Owen, D. R. J.

    2011-05-01

    Can manufacturers produce hundreds of millions of cans annually, increasingly, food cans are being opened by lifting a tab on the can end that initiates a fracture, which then propagates around a circumferential score. The damage and fracture mechanisms that lead to crack initiation and propagation in the opening process, however, are not fully understood, therefore optimisation of easy open end scores is largely based on trial and error. This paper presents an experimental analysis that concentrates on the combined shear and bending forces as applied to the particular industrial method concerning full aperture easy open ends. The influence of a gradually increasing gap measured between the score and shear force location on traditional groove geometries and depths are examined for two different packaging steels. Earlier studies have shown that the complete opening cycle depends on fracture modes I, II & III as well as their combination. Experimental results for Modes I, II & III will be presented, however attention will focus on the behaviour of the initial fracture point, whereby prior investigations have shown it to be influenced primarily by mode II shearing. After initial specimen manufacture, where the score is formed by pressing a punch into a thin steel sheet the predeformed scored specimens are loaded in shear to simulate the local stress field found during the initial opening phase. Experiments have been completed using a novel Mode II experimental technique that has been designed for use in the majority of commercially available tensile test machines. Experimental results indicate that opening forces can change radically with different gap sizes and that there is considerable potential for the industrialised process of can end manufacture to be optimised through the efficient management and control of the can ends dimensional parameters.

  9. Open ended tubing cutters

    Science.gov (United States)

    Girala, A. S. (Inventor)

    1981-01-01

    A self clamping cutting tool which includes a handle attached to a C-shaped housing is described. Rotatably mounted within the housing is a C-shaped tool body carrying a set of clamping rolls, two support rolls, and an edged cutting roll (64). The support rolls are disposed to one side of the axis of a pipe and the cutting roll is disposed to the other side of a pipe axis so that these rolls contact a pipe at three circumferential points. Cutter advancing apparatus advance the cutting roll toward the support rollers. The support rolls and cutting roll are rotatable independently of the C-shaped housing. A one way ratchet mechanism disposed between the C-shaped housing and the C-shaped tool body permits operation by movement in one rotational direction about the pipe axis.

  10. Spatial cluster analysis of nanoscopically mapped serotonin receptors for classification of fixed brain tissue

    Science.gov (United States)

    Sams, Michael; Silye, Rene; Göhring, Janett; Muresan, Leila; Schilcher, Kurt; Jacak, Jaroslaw

    2014-01-01

    We present a cluster spatial analysis method using nanoscopic dSTORM images to determine changes in protein cluster distributions within brain tissue. Such methods are suitable to investigate human brain tissue and will help to achieve a deeper understanding of brain disease along with aiding drug development. Human brain tissue samples are usually treated postmortem via standard fixation protocols, which are established in clinical laboratories. Therefore, our localization microscopy-based method was adapted to characterize protein density and protein cluster localization in samples fixed using different protocols followed by common fluorescent immunohistochemistry techniques. The localization microscopy allows nanoscopic mapping of serotonin 5-HT1A receptor groups within a two-dimensional image of a brain tissue slice. These nanoscopically mapped proteins can be confined to clusters by applying the proposed statistical spatial analysis. Selected features of such clusters were subsequently used to characterize and classify the tissue. Samples were obtained from different types of patients, fixed with different preparation methods, and finally stored in a human tissue bank. To verify the proposed method, samples of a cryopreserved healthy brain have been compared with epitope-retrieved and paraffin-fixed tissues. Furthermore, samples of healthy brain tissues were compared with data obtained from patients suffering from mental illnesses (e.g., major depressive disorder). Our work demonstrates the applicability of localization microscopy and image analysis methods for comparison and classification of human brain tissues at a nanoscopic level. Furthermore, the presented workflow marks a unique technological advance in the characterization of protein distributions in brain tissue sections.

  11. Owhership of flats

    OpenAIRE

    Přibil, Jan

    2012-01-01

    Ownership of Flats Summary In his diploma thesis "Ownership of Flats", the author focuses on applicable law of flat ownership in the Czech Republic, especially the Flat Ownership Act 72/1994 Sb. The author puts the contemporary regulation in historical context; he describes the theoretical principles underlining the current applicable law and defines in detail the basic legal terms used by the Flat Ownership Act. Original and derivative forms of flat ownership acquisition are explained, namel...

  12. An Enhanced Three-Level Voltage Switching State Scheme for Direct Torque Controlled Open End Winding Induction Motor

    Science.gov (United States)

    Kunisetti, V. Praveen Kumar; Thippiripati, Vinay Kumar

    2018-01-01

    Open End Winding Induction Motors (OEWIM) are popular for electric vehicles, ship propulsion applications due to less DC link voltage. Electric vehicles, ship propulsions require ripple free torque. In this article, an enhanced three-level voltage switching state scheme for direct torque controlled OEWIM drive is implemented to reduce torque and flux ripples. The limitations of conventional Direct Torque Control (DTC) are: possible problems during low speeds and starting, it operates with variable switching frequency due to hysteresis controllers and produces higher torque and flux ripple. The proposed DTC scheme can abate the problems of conventional DTC with an enhanced voltage switching state scheme. The three-level inversion was obtained by operating inverters with equal DC-link voltages and it produces 18 voltage space vectors. These 18 vectors are divided into low and high frequencies of operation based on rotor speed. The hardware results prove the validity of proposed DTC scheme during steady-state and transients. From simulation and experimental results, proposed DTC scheme gives less torque and flux ripples on comparison to two-level DTC. The proposed DTC is implemented using dSPACE DS-1104 control board interface with MATLAB/SIMULINK-RTI model.

  13. A New Dual Circularly Polarized Feed Employing a Dielectric Cylinder-Loaded Circular Waveguide Open End Fed by Crossed Dipoles

    Directory of Open Access Journals (Sweden)

    Jae-Hoon Bang

    2016-01-01

    Full Text Available This paper presents a new dual circularly polarized feed that provides good axial ratio over wide angles and low cross-polarized radiation in backward direction. A circular waveguide open end is fed with two orthogonally polarized waves in phase quadrature by a pair of printed crossed dipoles and a compact connectorized quadrature hybrid coupler. The waveguide aperture is loaded with a dielectric cylinder to reduce the cross-polarization beyond 90 degrees off the boresight. The fabricated feed has, at 5.5 GHz, 6.33-dBic copolarized gain, 3-dB beamwidth of 106°, 10-dB beamwidth of 195°, 3-dB axial ratio beamwidth of 215°, maximum cross-polarized gain of −21.4 dBic, and 27-dB port isolation. The reflection coefficient of the feed is less than −10 dB at 4.99–6.09 GHz.

  14. Willingness to pay more for value-added pomegranate juice (Punica granatum L.): An open-ended contingent valuation.

    Science.gov (United States)

    Romano, Karen Rodrigues; Dias Bartolomeu Abadio Finco, Fernanda; Rosenthal, Amauri; Vinicius Alves Finco, Marcus; Deliza, Rosires

    2016-11-01

    This study aimed at estimating the consumer's willingness to pay (WTP) more for value-added pomegranate juice using the contingent valuation method (CVM). The WTP was estimated applying the open-ended elicitation technique with 454 consumers in two supermarkets located in Rio de Janeiro, Brazil. The average consumer's WTP more for pomegranate juice was estimated in R$2.04 (Brazilian currency) and the income elasticity coefficient at the midpoint was 0.19, i.e., a 10% increase in consumer income will increase, on average, 1.9% the WTP of pomegranate juice (ceteris paribus). Therefore, the income elasticity coefficient was considered inelastic, once an increase in income would have low effect on the WTP for these consumers. The results indicated that the consumers were interested in acquiring a non-traditional juice processed using a technology that preserves vitamins and antioxidants, maintains the flavor of "fresh juice" without colorants and preservatives, despite the pomegranate is not part of the Brazilian diet. Copyright © 2016 Elsevier Ltd. All rights reserved.

  15. Chiropractors' perception of occupational stress and its influencing factors: a qualitative study using responses to open-ended questions.

    Science.gov (United States)

    Williams, Shawn

    2016-01-01

    Job stress and emotional exhaustion have been shown to have a negative impact on the helping professional. The development and causal relations of job stress and emotional exhaustion are rather unclear in the chiropractic profession. The objective of this study is to understand the main sources of occupational stress and emotional exhaustion among doctors of chiropractic. Analysis of the written responses to web-based open-ended questionnaire was performed using an interpretive research methodology. Additionally, cross tabulation and Chi square statistical tests were conducted to match and couple the demographic data with the categorical themes. Fourteen professional stress categories emerged from the 970 completed surveys. "Managed Care Organization regulation", "Managed Care reimbursement" and "Scope of Practice Issues" were the most common stressors that negatively influenced chiropractors' professional and personal lives. The results of the categorical analysis suggests that age, marital status, number of years in practice and location of practice may have an influence on the category of stress reported by chiropractors. The qualitative approach revealed common, conventional and culture-specific job stressors in doctors of chiropractic. Notably, these findings suggest an association between third-party payer influences (increased regulation/decreased reimbursement) with that of increased job stress. Further research will be undertaken to refine the stress and satisfaction parameters and address stress interventions.

  16. Open-ended Laboratory Investigations in a High School Physics Course: The difficulties and rewards of implementing inquiry-based learning in a physics lab

    Science.gov (United States)

    Szott, Aaron

    2014-01-01

    often closed-ended. The outcomes are known in advance and students replicate procedures recommended by the teacher. Over the years, I have come to appreciate the great opportunities created by allowing students investigative freedom in physics laboratories. I have realized that a laboratory environment in which students are free to conduct investigations using procedures of their own design can provide them with varied and rich opportunities for discovery. This paper describes what open-ended laboratory investigations have added to my high school physics classes. I will provide several examples of open-ended laboratories and discuss the benefits they conferred on students and teacher alike.

  17. Development of a microwave dielectric spectroscopy system for materials characterization using the open-ended coaxial probe technique

    Energy Technology Data Exchange (ETDEWEB)

    Garcia-Ruiz, I.; Aviles-Castro, D. [Centro Nacional de Metrologia, Queretaro (Mexico); Jardon-Aguilar, H. [Instituto Politecnico Nacional, Mexico, D. F. (Mexico)

    2001-02-01

    Dielectric spectroscopy is a measurement technique to characterize the interaction between electromagnetic energy and macroscopic samples as a function of frequency. It is based on the measurement of complex permittivity plus conductivity and it has shown to be very useful to provide information about internal structure of matter. It has some advantages over others like optical or chemical analysis: it is very fast, easy to implement, requires little or no preparation of the sample, it can be non-destructive and/or minimally intrusive. In this paper the development of a dielectric spectroscopy system for the microwave frequency range (50 MHz-20 GHz), using an open-ended coaxial probe as sensor, is described. The complete system includes a vector network analyzer, a microwave coaxial cable, the probe, a sample holder and a computer to automate measurements and further data processing. This system has been used to measure some liquid and solid materials such as alcohol, water and Teflon. The real and imaginary parts of permittivity as function of frequency, for several sugarcane alcohol and deionised water mixtures, tequilas and Teflon samples are given. Measurement repeatability and accuracy considerations were taken and it was identified that uncertainty of reference standards and system repeatability are the most important error sources. Also, it was found that open-ended coaxial probe technique is appropriate for measuring not only liquids but also solid materials. Some of the obtained results were compared to those reported in literature and good convergence was observed. [Spanish] La espectroscopia dielectrica es una tecnica moderna de medicion para caracterizar la interaccion entre la energia electromagnetica y muestras macroscopicas como funcion de la frecuencia. Esta tecnica se basa en la medicion de la permitividad compleja y conductividad de los materiales y ha mostrado ser muy util para proporcionar informacion sobre la estructura interna de estos. Tiene

  18. Comparison between Long-Menu and Open-Ended Questions in computerized medical assessments. A randomized controlled trial

    Directory of Open Access Journals (Sweden)

    Fischer Martin R

    2006-10-01

    Full Text Available Abstract Background Long-menu questions (LMQs are viewed as an alternative method for answering open-ended questions (OEQs in computerized assessment. So far this question type and its influence on examination scores have not been studied sufficiently. However, the increasing use of computerized assessments will also lead to an increasing use of this question type. Using a summative online key feature (KF examination we evaluated whether LMQs can be compared with OEQs in regard to the level of difficulty, performance and response times. We also evaluated the content for its suitability for LMQs. Methods We randomized 146 fourth year medical students into two groups. For the purpose of this study we created 7 peer-reviewed KF-cases with a total of 25 questions. All questions had the same content in both groups, but nine questions had a different answer type. Group A answered 9 questions with an LM type, group B with an OE type. In addition to the LM answer, group A could give an OE answer if the appropriate answer was not included in the list. Results The average number of correct answers for LMQs and OEQs showed no significant difference (p = 0.93. Among all 630 LM answers only one correct term (0.32% was not included in the list of answers. The response time for LMQs did not significantly differ from that of OEQs (p = 0.65. Conclusion LMQs and OEQs do not differ significantly. Compared to standard multiple-choice questions (MCQs, the response time for LMQs and OEQs is longer. This is probably due to the fact that they require active problem solving skills and more practice. LMQs correspond more suitable to Short answer questions (SAQ then to OEQ and should only be used when the answers can be clearly phrased, using only a few, precise synonyms. LMQs can decrease cueing effects and significantly simplify the scoring in computerized assessment.

  19. Questões discursivas para avaliação escolar = Open-ended questions in school tests

    Directory of Open Access Journals (Sweden)

    Maria Auxiliadora Bezerra

    2008-07-01

    Full Text Available O objetivo deste artigo é descrever questões discursivas presentes em atividades escolares do Ensino Médio para avaliação da aprendizagem. Foram estudadas, à luz de teorias sobre atividades e tarefas escolares (Chartrand, 2002, sobre elaboração de provas eexercícios (Moretto, 2005; Bloom, 1973 e sobre perguntas de compreensão (Marcuschi, 1996, 93 questões recolhidas nas disciplinas Literatura Brasileira, História e Geografia. Foram descritas questões (descontextualizadas, propondo, do ponto de vista cognitivo,tarefas funcionais (predominantes, seguidas de formativas e metacognitivas. Seus comandos são dados por meio de pronomes interrogativos (principalmente e de verbos no imperativo ou no infinitivo. As questões focalizam os conteúdos específicos das disciplinas, privilegiando seus conceitos, e enfatizam o desenvolvimento cognitivo dos alunos, sem relação com aspectos sociais. Parece ser suficiente a demonstração passiva de conhecimentoscomo resultado de uma aprendizagem correspondente a acúmulo de informações e de um ensino entendido como repasse de dados.Open-ended questions in high school activities are described to evaluate the learning process. Ninety-three questions fromBrazilian Literature, History and Geography were analyzed, based on school activity and task theories (Chartrand, 2002, test and exercise theories (Moretto, 2005; Bloom, 1973, and comprehension question theories (Marcuschi, 1996. (Decontextualized questions,which propose (predominantly functional, formative and metacognitive tasks, were described from the cognitive point-of-view. Question instructions were given by using (mainly interrogative pronouns and verbs either in the infinitive or in the imperative. Questions focus on the specific contents of the subject matter, emphasizing concepts and the students’ cognitive development, regardless of social aspects. Passive demonstration of knowledge as a result of learning related to collected passive

  20. Lattice Boltzmann analysis of effect of heating location and Rayleigh number on natural convection in partially heated open ended cavity

    Energy Technology Data Exchange (ETDEWEB)

    Gangawane, Krunal Madhukar; Bharti, Ram Prakash; Kumar, Surendra [Indian Institute of Technology Roorkee, Uttarakhand (India)

    2015-08-15

    Natural convection characteristics of a partially heated open ended square cavity have been investigated numerically by using an in-house computational flow solver based on the passive scalar thermal lattice Boltzmann method (PS-TLBM) with D2Q9 (two-dimensional and nine-velocity link) lattice model. The partial part of left wall of the cavity is heated isothermally at either of the three different (bottom, middle and top) locations for the fixed heating length as half of characteristic length (H/2) while the right wall is open to the ambient conditions. The other parts of the cavity are thermally isolated. In particular, the influences of partial heating locations and Rayleigh number (103≤ Ra≤106) in the laminar zone on the local and global natural convection characteristics (such as streamline, vorticity and isotherm contours; centerline variations of velocity and temperature; and local and average Nusselt numbers) have been presented and discussed for the fixed value of the Prandtl number (Pr=0.71). The streamline patterns show qualitatively similar nature for all the three heating cases and Rayleigh numbers, except the change in the recirculation zone which is found to be largest for middle heating case. Isotherm patterns are shifted towards a partially heated wall on increasing Rayleigh number and/or shifting of heating location from bottom to top. Both the local and average Nusselt numbers, as anticipated, shown proportional increase with Rayleigh number. The cavity with middle heating location shown higher heat transfer rate than that for the top and bottom heating cases. Finally, the functional dependence of the average Nusselt number on flow governing parameters is also presented as a closure relationship for the best possible utilization in engineering practices and design.

  1. Development of Open-Ended Problems for Measuring The Higher-Order-Thinking-Skills of High School Students on Global Warming Phenomenon

    Science.gov (United States)

    Fianti; Najwa, F. L.; Linuwih, S.

    2017-04-01

    Higher-order-thinking-skills can not be developed directly, except by training which is employing open-ended problems for measuring and developing critics, creativeness, and problem-solving thinking-skills of students. This study is a research and development producing open-ended problems. The purpose of this study is to measure the properness and effectiveness of the developed product and to observe the profile of higher-order-thinking-skills of students on global warming phenomenon. The result of properness test of open-ended problems according to the experts is 92,59% on the first stage and 97,53% on the second stage, so we can assume that the product isvery proper. The result of effectiveness test shows the coefficient of correlation between student’s midterm test scores and open-ended questions is 0,634 which is in the category of strong. Higher-order-thinking-skills of SMA Negeri 1 Salatiga students is in the category of good with the average achievement scores 61,28.

  2. The Different Role of Working Memory in Open-Ended versus Closed-Ended Creative Problem Solving: A Dual-Process Theory Account

    Science.gov (United States)

    Lin, Wei-Lun; Lien, Yunn-Wen

    2013-01-01

    This study examined how working memory plays different roles in open-ended versus closed-ended creative problem-solving processes, as represented by divergent thinking tests and insight problem-solving tasks. With respect to the analysis of different task demands and the framework of dual-process theories, the hypothesis was that the idea…

  3. Eco-Dialogical Learning and Translanguaging in Open-Ended 3D Virtual Learning Environments: Where Place, Time, and Objects Matter

    Science.gov (United States)

    Zheng, Dongping; Schmidt, Matthew; Hu, Ying; Liu, Min; Hsu, Jesse

    2017-01-01

    The purpose of this research was to explore the relationships between design, learning, and translanguaging in a 3D collaborative virtual learning environment for adolescent learners of Chinese and English. We designed an open-ended space congruent with ecological and dialogical perspectives on second language acquisition. In such a space,…

  4. Threats to Validity When Using Open-Ended Items in International Achievement Studies: Coding Responses to the PISA 2012 Problem-Solving Test in Finland

    Science.gov (United States)

    Arffman, Inga

    2016-01-01

    Open-ended (OE) items are widely used to gather data on student performance in international achievement studies. However, several factors may threaten validity when using such items. This study examined Finnish coders' opinions about threats to validity when coding responses to OE items in the PISA 2012 problem-solving test. A total of 6…

  5. 17 CFR 239.15 - Form N-1 for open-end management investment companies registered on Form N-8A.

    Science.gov (United States)

    2010-04-01

    ... management investment companies registered on Form N-8A. 239.15 Section 239.15 Commodity and Securities... Registration Statements § 239.15 Form N-1 for open-end management investment companies registered on Form N-8A...-end management investment companies that are separate accounts of insurance companies as defined by...

  6. What Bacteria Are Living in My Food?: An Open-Ended Practical Series Involving Identification of Unknown Foodborne Bacteria Using Molecular Techniques

    Science.gov (United States)

    Prasad, Prascilla; Turner, Mark S.

    2011-01-01

    This open-ended practical series titled "Molecular Identification of Unknown Food Bacteria" which extended over a 6-week period was designed with the aims of giving students an opportunity to gain an understanding of naturally occurring food bacteria and skills in contemporary molecular methods using real food samples. The students first isolated…

  7. Choice consistency and preference stability in test-retests of discrete choice experiment and open-ended willingness to pay elicitation formats

    NARCIS (Netherlands)

    Brouwer, R.; Logar, I.; Sheremet, O.I.

    2017-01-01

    This study tests the temporal stability of preferences, choices and willingness to pay (WTP) values using both discrete choice experiment (DCE) and open-ended (OE) WTP elicitation formats. The same sample is surveyed three times over the course of two years using each time the same choice sets.

  8. Comparisons of an open-ended vs. forced-choice 'mind reading' task: implications for measuring perspective-taking and emotion recognition.

    Directory of Open Access Journals (Sweden)

    Tracy G Cassels

    Full Text Available Perspective-taking and emotion recognition are essential for successful social development and have been the focus of developmental research for many years. Although the two abilities often overlap, they are distinct and our understanding of these abilities critically rests upon the efficacy of existing measures. Lessons from the literature differentiating recall versus recognition memory tasks led us to hypothesize that an open-ended emotion recognition measure would be less reliant on compensatory strategies and hence a more specific measure of emotion recognition abilities than a forced-choice task. To this end, we compared an open-ended version of the Reading the Mind in the Eyes Task with the original forced-choice version in two studies: 118 typically-developing 4- to 8-year-olds (Study 1 and 139 5- to 12-year-olds; 85 typically-developing and 54 with learning disorders (Study 2. We found that the open-ended version of the task was a better predictor of empathy and more reliably discriminated typically-developing children from those with learning disorders. As a whole, the results suggest that the open-ended version is a more sensitive measure of emotion recognition specifically.

  9. Automated Scoring of Short-Answer Open-Ended GRE® Subject Test Items. ETS GRE® Board Research Report No. 04-02. ETS RR-08-20

    Science.gov (United States)

    Attali, Yigal; Powers, Don; Freedman, Marshall; Harrison, Marissa; Obetz, Susan

    2008-01-01

    This report describes the development, administration, and scoring of open-ended variants of GRE® Subject Test items in biology and psychology. These questions were administered in a Web-based experiment to registered examinees of the respective Subject Tests. The questions required a short answer of 1-3 sentences, and responses were automatically…

  10. Values and motivations of private forest owners in the United States: a framework based on open-ended responses in the national woodland owner survey

    Science.gov (United States)

    David N. Bengston; Brett J. Butler; Stanley T. Asah

    2009-01-01

    The National Woodland Owner Survey (NWOS) is a recurring and comprehensive national survey of private forest landowners in the United States, and is a social complement to the U.S. Forest Service Forest Inventory and Analysis program's biologic resource inventory. An open-ended question in the NWOS explores private forest owners' motivations and values...

  11. Open-Ended Waveguide Measurement and Numerical Simulation of the Reflectivity of Petri Dish Supported Skin Cell Monolayers in the mm-wave Range

    Science.gov (United States)

    Beneduci, Amerigo; Chidichimo, Giuseppe

    2012-05-01

    Open-ended waveguide reflectometry is a promising tool for permittivity and other material properties calculation at mm-waves (30-300 GHz). Measurement of the reflection coefficient does not require sample manipulation, allowing in vivo and in vitro non destructive studies on cells. Here we used this technique for measuring the power reflection coefficient (reflectivity) of water and Petri dish supported human skin melanoma and keratinocyte cell cultures, in the 53-72 GHz frequency range. The dependence of the reflectivity on polystyrene or glass thickness of the Petri base plate and on the cell layer thickness was analyzed. Permittivity data were then easily retrieved by using a plane wave-dominant mode approach for formulating the reflectivity at the aperture of the flange-mounted open-ended rectangular waveguide probe. Limits and validity of such an approximate approach were analyzed and compared with full-wave near field formulations for which magnitude and phase of the reflection coefficient must be measured and solved using complicated systems of integral equations and extensive numerical calculation. Finally, Petri dish reflectivity measured by the open-ended waveguide method was compared with that numerically simulated under far-field exposure conditions used in a large number of in vitro studies. Such an analysis showed that, under certain conditions, open-ended reflectivity values approach the far field ones.

  12. Authentic Learning Enviroment in Analytical Chemistry Using Cooperative Methods and Open-Ended Laboratories in Large Lecture Courses

    Science.gov (United States)

    Wright, John C.

    1996-09-01

    It is recognized that a need exists to move from the passive learning styles that have characterized chemistry courses to an active style in which students participate and assume responsibility for their learning (1 - 5). In addition, it is argued that course reform should be linked to authentic student achievement, so that students can actively experience the feelings of practicing professionals (6). Course experiments where such changes have been introduced have proven successful but the number of examples of such changes is limited in the higher level courses or courses with large enrollments (7 - 11). In this paper, a one-semester introductory analytical chemistry course is described that accomplishes this goal by the use of open-ended laboratories, cooperative learning, and spreadsheet programs. The course uses many of the ideas described by Walters (7). It is offered at the upperclass level to nonmajors and at the freshman level to students with solid chemistry backgrounds from high school. Typically there are 90 students, who are divided into 5 sections. A teaching assistant is assigned to each section. The course has two 4-hour laboratories and two or three lectures each week (depending on whether it is the upperclass or freshman course). The heart of the course changes is the use of open-ended laboratory experiments in the last half of the course. A sample group project is to have the students develop a mixture of acid-base indicators that can serve as a spectroscopic pH meter. These projects are enhanced by dividing the students into teams of four who take charge of all aspects of accomplishing the projects' goals. Since there are many skills required to make these projects work, the first half of the course is spent developing the individual conceptual, computational, laboratory, problem solving, and group skills so students are prepared for the last half. These changes have markedly improved the student attitudes towards each other and towards learning

  13. Spouses of Military Members' Experiences and Insights: Qualitative Analysis of Responses to an Open-Ended Question in a Survey of Health and Wellbeing

    Science.gov (United States)

    Runge, Catherine E.; Waller, Michael; MacKenzie, Alison; McGuire, Annabel C. L.

    2014-01-01

    Introduction There are few studies on the experiences of spouses of military members, with most focused on adverse impacts of deployment. Responses to an open-ended question in a survey of spouses' health and wellbeing enabled access to perceptions and insights on a broad range of topics. The objective of this investigation was to examine how respondents used the open-ended question and what they discussed, in aim of informing support service agencies and spouses of military members. Methods Thematic analysis was conducted on responses to the open-ended question. Descriptive analysis was performed on the demographics, military member characteristics and self-reported health of respondents and non-respondents to the open-ended question. Findings Over a quarter (28.5%) of the 1,332 survey participants answered the open-ended question, with respondents having a significantly higher level of education than non–respondents. Respondents expressed negative and positive experiences and insights on military life, provided personal information, commented on the survey, and qualified their responses to closed-ended questions. Topics included ‘inadequate support’, ‘deployment impacts’, ‘suggestions for supporting agencies’, ‘appraisal of experiences’ and ‘coping strategies’. Conclusions This investigation uncovered issues of importance to spouses of military members that were not included or identified in a quantitative study. The findings provide a platform from which to explore these issues further, particularly the impact of military life on the non-serving spouse's career. The findings also provide support agencies with evidence to strengthen their services and they give spouses an opportunity to reflect on their own and others' feelings and evaluations of military life. PMID:25479135

  14. Effect Of Open Ended Teaching Learning Approach On Secondary School Students Mathematics Achievement In Learning Three Dimensional Geometry

    Directory of Open Access Journals (Sweden)

    Chogo C.N.

    2017-12-01

    Full Text Available Mathematics is globally valued for use by an individual and society. It plays a significant role in the development of modern science and technology. Despite its importance students motivation to learn and achievement at national examinations globally and at the KCSE mathematics examination in Kenya particularly has been dismal over the years. The learners low achievement in the subject has been attributed to the didactic teaching methods that the teachers use among other factors. The study of geometry in Mathematics poses a number of difficulties to learners which are different in nature from those of arithmetic and algebra. This is because geometry is primarily abstract in nature. The purpose of this study was to determine the effects of Open Ended Teaching and Learning Approach OETLA on Secondary School students mathematics achievement in learning Three Dimensional Geometry 3DG. The study employed Solomon four non-equivalent control group design. The two experimental groups E1amp E2 received OETLA treatment while the control groups C1ampC2 were taught using the conventional teaching and learning methods. Only E1amp C1 took a pre-test and a post test for all the groups. The target population for this study was form four 17 year old students of secondary schools in Marani Sub County in Kisii County. Purposive sampling was used to obtain the four county mixed-sex secondary schools for the study. A total of 152 students formed the sample size. Students Mathematics Achievement Test SMAT was used to collect data. The instruments were validated by three experts from the department of curriculum and instruction of Egerton University and three Secondary School Mathematics Heads of Department. The reliability of the instruments were established using Cronbachs Alpha. A reliability coefficient of 0.92 was obtained and thus considered acceptable. The SMAT was administered to two groups as a pretest before the treatment and as a posttest to all the four

  15. Transport mechanisms in capillary condensation of water at a single-asperity nanoscopic contact.

    Science.gov (United States)

    Sirghi, Lucel

    2012-02-07

    Transport mechanisms involved in capillary condensation of water menisci in nanoscopic gaps between hydrophilic surfaces are investigated theoretically and experimentally by atomic force microscopy (AFM) measurements of capillary force. The measurements showed an instantaneous formation of a water meniscus by coalescence of the water layers adsorbed on the AFM tip and sample surfaces, followed by a time evolution of meniscus toward a stationary state corresponding to thermodynamic equilibrium. This dynamics of the water meniscus is indicated by time evolution of the meniscus force, which increases with the contact time toward its equilibrium value. Two water transport mechanisms competing in this meniscus dynamics are considered: (1) Knudsen diffusion and condensation of water molecules in the nanoscopic gap and (2) adsorption of water molecules on the surface region around the contact and flow of the surface water toward the meniscus. For the case of very hydrophilic surfaces, the dominant role of surface water transportation on the meniscus dynamics is supported by the results of the AFM measurements of capillary force of water menisci formed at sliding tip-sample contacts. These measurements revealed that fast movement of the contact impedes on the formation of menisci at thermodynamic equilibrium because the flow of the surface water is too slow to reach the moving meniscus.

  16. Graphene Quantum Dot-Aerogel: From Nanoscopic to Macroscopic Fluorescent Materials. Sensing Polyaromatic Compounds in Water.

    Science.gov (United States)

    Martín-Pacheco, Ana; Del Río Castillo, Antonio Esaú; Martín, Cristina; Herrero, María Antonia; Merino, Sonia; García Fierro, José Luis; Díez-Barra, Enrique; Vázquez, Ester

    2018-05-17

    Fluorescence based on quantum confinement is a property restricted to the nanoscopic range. The incorporation of nanoparticles in a three-dimensional polymeric network could afford macroscopic scaffolds that show nanoscopic properties. Moreover, if these scaffolds are based on strong bonds, the stability of the resulting materials can be preserved, thus enhancing their final applications. We report for the first time the preparation of a graphene quantum dot (GQD) composite based on a cationic covalent network. This new material has unusual features: (i) the final composite remains stable after several swelling-deswelling cycles, thus demonstrating strong interactions between GQDs and the polymeric material, and therefore it could be used as a portable system. (ii) Fluorescence emission in the composite and in solution is quasi-independent to the excitation wavelength. (iii) However, and in contrast to the behavior observed in GQD solutions, the fluorescence of the composite remains unaltered over a wide pH range and in the presence of different ions commonly found in tap water. (iv) Fluorescence quenching is only observed as a consequence of molecules that bear aromatic systems, and this could be applied to the preparation of in situ water sensors.

  17. Computer-Assisted, Self-Interviewing (CASI Compared to Face-to-Face Interviewing (FTFI with Open-Ended, Non-Sensitive Questions

    Directory of Open Access Journals (Sweden)

    John Fairweather PhD

    2012-07-01

    Full Text Available This article reports results from research on cultural models, and assesses the effects of computers on data quality by comparing open-ended questions asked in two formats—face-to-face interviewing (FTFI and computer-assisted, self-interviewing (CASI. We expected that for our non-sensitive topic, FTFI would generate fuller and richer accounts because the interviewer could facilitate the interview process. Although the interviewer indeed facilitated these interviews, which resulted in more words in less time, the number of underlying themes found within the texts for each interview mode was the same, thus resulting in the same models of national culture and innovation being built for each mode. Our results, although based on an imperfect research design, suggest that CASI can be beneficial when using open-ended questions because CASI is easy to administer, capable of reaching more efficiently a large sample, and able to avoid the need to transcribe the recorded responses.

  18. Computer-Assisted, Self-Interviewing (CASI) Compared to Face-to-Face Interviewing (FTFI) with Open-Ended, Non-Sensitive Questions

    OpenAIRE

    John Fairweather PhD; Tiffany Rinne PhD; Gary Steel PhD

    2012-01-01

    This article reports results from research on cultural models, and assesses the effects of computers on data quality by comparing open-ended questions asked in two formats—face-to-face interviewing (FTFI) and computer-assisted, self-interviewing (CASI). We expected that for our non-sensitive topic, FTFI would generate fuller and richer accounts because the interviewer could facilitate the interview process. Although the interviewer indeed facilitated these interviews, which resulted in more w...

  19. Renal access in PNL under sonographic guidance: Do we really need to insert an open end ureteral catheter in dilated renal systems? A prospective randomized study.

    Science.gov (United States)

    Eryildirim, Bilal; Tuncer, Murat; Camur, Emre; Ustun, Fatih; Tarhan, Fatih; Sarica, Kemal

    2017-10-03

    To evaluate the true necessity of open end ureteral catheter insertion in patients with moderate to severe pelvicalyceal system dilation treated with percutaneous nephrolithotomy (PNL) under sonographic guidance. 50 cases treated with PNL under sonographic guidance in prone position for solitary obstructing renal stones were evaluated. Patients were randomly divided into two groups; Group 1: Patients in whom a open end ureteral catheter was inserted prior to the procedure; Group 2: Patients receiving no catheter before PNL. In addition to the duration of the procedure as a whole and also all relevant stages as well, radiation exposure time, hospitalization period, mean nephrostomy tube duration, mean drop in Hb levels and all intra and postoperative complications have been evaluated. Mean size of the stones was 308.5 ± 133.2 mm2. Mean total duration of the PNL procedure in cases with open end ureteral catheter was significantly longer than the other cases (p < 0.001). Evaluation of the outcomes of the PNL procedures revealed no statistically significant difference between two groups regarding the stone-free rates (86% vs 84%). Additionally, there was no significant difference with respect to the duration of nephrostomy tube, hospitalization period and secondary procedures needed, complication rates as well as the post-operative Hb drop levels in both groups (p = 0.6830). Our results indicate that the placement of an open end ureteral catheter prior to a PNL procedure performed under sonographic access may not be indicated in selected cases presenting with solitary obstructing renal pelvic and/or calyceal stones.

  20. EKSPERIMENTASI MODEL PEMBELAJARAN KOOPERATIF TIPE THINK PAIR SHARE (TPS DENGAN PENDEKATAN OPEN-ENDED DITINJAU DARI DISPOSISI MATEMATIS SISWA KELAS VIII SMP NEGERI DI KABUPATEN PURWOREJO

    Directory of Open Access Journals (Sweden)

    Zainnur Wijayanto

    2015-02-01

    Full Text Available prestasi belajar matematika lebih baik, siswa dengan disposisi matematis tinggi, sedang, atau rendah, 4 pada masing-masing kategori disposisi matematis, manakah yang mempunyai prestasi belajar matematika lebih baik, siswa yang dikenai model pembelajaran kooperatif tipe TPS dengan pendekatan open-ended atau pembelajaran langsung. Penelitian ini merupakan penelitian eksperimental semu. Populasi penelitian ini adalah siswa kelas VIII SMP Negeri di Kabupaten Purworejo tahun ajaran 2013/2014. Sampel dalam penelitian ini adalah siswa SMPN 20 Purworejo, SMPN 14 Purworejo, SMPN 13 Purworejo yang diambil secara stratified cluster random sampling. Instrumen yang digunakan untuk mengumpulkan data adalah instrumen tes prestasi belajar matematika, instrumen angket disposisi matematis siswa. Teknik analisis data yang digunakan adalah uji hipotesis menggunakan anava dua jalan dengan sel tak sama. Dari hasil analisis disimpulkan bahwa : 1 prestasi belajar matematika siswa yang diberi pembelajaran dengan model pembelajaran kooperatif tipe TPS dengan pendekatan open-ended lebih baik daripada siswa yang diberi pembelajaran langsung, 2 prestasi belajar matematika siswa dengan disposisi matematis tinggi lebih baik daripada siswa dengan disposisi matematis sedang dan rendah, begitu juga dengan prestasi belajar matematika siswa dengan disposisi matematis sedang lebih baik daripada siswa dengan disposisi matematis rendah, 3 pada model pembelajaran kooperatif tipe TPS dengan pendekatan open-ended prestasi belajar matematika siswa yang memiliki disposisi matematis tinggi lebih baik daripada siswa yang memiliki disposisi matematis sedang maupun rendah. Pada pembelajaran langsung, siswa dengan disposisi matematis tinggi memiliki prestasi belajar yang lebih baik daripada siswa yang memiliki disposisi matematis sedang dan rendah, siswa dengan disposisi matematis sedang memiliki prestasi belajar yang sama dengan siswa yang memiliki disposisi matematis rendah, 4 Pada siswa

  1. Using open-ended data to enrich survey results on the meanings of self-rated health: a study among women in underprivileged communities in Beirut, Lebanon.

    Science.gov (United States)

    Salem, Mylene Tewtel; Abdulrahim, Sawsan; Zurayk, Huda

    2009-12-01

    This study extends the debate on self-rated health by using different sources of data in the same study to explore the meanings of self-rated health among women who live in socio-economically disadvantaged communities in Beirut, Lebanon. Using data from the Urban Health Study, a cross-sectional household survey of 1,869 women between 15 and 59 years of age, multiple logistic regression models were developed to assess factors associated with self-rated health. Also, open-ended data was used to analyze women's explanations of their self-rated health ratings. Self-rated health was found to be a complex concept, associated not only with physical health but also with a combination of social, psychological, and behavioral factors. This open-ended analysis revealed new meanings of self-rated health that are often not included in self-rated health epidemiologic research, such as women's experiences with pain and fatigue, as well as exposure to financial stressors and the legacy of wars. We argue that triangulating survey and open-ended data provides a better understanding of the context-specific social and cultural meanings of self-rated health.

  2. Convergent validity between a discrete choice experiment and a direct, open-ended method: comparison of preferred attribute levels and willingness to pay estimates.

    Science.gov (United States)

    Marjon van der Pol; Shiell, Alan; Au, Flora; Johnston, David; Tough, Suzanne

    2008-12-01

    The Discrete Choice Experiment (DCE) has become increasingly popular as a method for eliciting patient or population preferences. If DCE estimates are to inform health policy, it is crucial that the answers they provide are valid. Convergent validity is tested in this paper by comparing the results of a DCE exercise with the answers obtained from direct, open-ended questions. The two methods are compared in terms of preferred attribute levels and willingness to pay (WTP) values. Face-to-face interviews were held with 292 women in Calgary, Canada. Similar values were found between the two methods with respect to preferred levels for two out of three of the attributes examined. The DCE predicted less well for levels outside the range than for levels inside the range reaffirming the importance of extensive piloting to ensure appropriate level range in DCEs. The mean WTP derived from the open-ended question was substantially lower than the mean derived from the DCE. However, the two sets of willingness to pay estimates were consistent with each other in that individuals who were willing to pay more in the open-ended question were also willing to pay more in the DCE. The difference in mean WTP values between the two approaches (direct versus DCE) demonstrates the importance of continuing research into the different biases present across elicitation methods.

  3. Nanoscopic studies of domain structure dynamics in ferroelectric La:HfO2 capacitors

    Science.gov (United States)

    Buragohain, P.; Richter, C.; Schenk, T.; Lu, H.; Mikolajick, T.; Schroeder, U.; Gruverman, A.

    2018-05-01

    Visualization of domain structure evolution under an electrical bias has been carried out in ferroelectric La:HfO2 capacitors by a combination of Piezoresponse Force Microscopy (PFM) and pulse switching techniques to study the nanoscopic mechanism of polarization reversal and the wake-up process. It has been directly shown that the main mechanism behind the transformation of the polarization hysteretic behavior and an increase in the remanent polarization value upon the alternating current cycling is electrically induced domain de-pinning. PFM imaging and local spectroscopy revealed asymmetric switching in the La:HfO2 capacitors due to a significant imprint likely caused by the different boundary conditions at the top and bottom interfaces. Domain switching kinetics can be well-described by the nucleation limited switching model characterized by a broad distribution of the local switching times. It has been found that the domain velocity varies significantly throughout the switching process indicating strong interaction with structural defects.

  4. Radiative interaction of a focused relativistic electron beam in energy-loss spectroscopy of nanoscopic platelets

    International Nuclear Information System (INIS)

    Itskovsky, M. A.; Maniv, T.; Cohen, H.

    2008-01-01

    A quantum-mechanical scattering theory for relativistic, highly focused electron beams in the vacuum near nanoscopic platelets is presented, revealing an excitation mechanism due to the electron wave scattering from the platelet edges. Radiative electromagnetic excitations within the light cone are shown to arise, allowed by the breakdown of momentum conservation along the beam axis in the inelastic-scattering process. Calculated for metallic (silver and gold) and insulating (SiO 2 and MgO) nanoplatelets, radiative features are revealed above the main surface-plasmon-polariton peak, and dramatic enhancements in the electron-energy-loss probability at gaps of the 'classical' spectra are found. The corresponding radiation should be detectable in the vacuum far-field zone, with e beams exploited as sensitive 'tip detectors' of electronically excited nanostructures

  5. Radiative interaction of a focused relativistic electron beam in energy-loss spectroscopy of nanoscopic platelets

    Science.gov (United States)

    Itskovsky, M. A.; Cohen, H.; Maniv, T.

    2008-07-01

    A quantum-mechanical scattering theory for relativistic, highly focused electron beams in the vacuum near nanoscopic platelets is presented, revealing an excitation mechanism due to the electron wave scattering from the platelet edges. Radiative electromagnetic excitations within the light cone are shown to arise, allowed by the breakdown of momentum conservation along the beam axis in the inelastic-scattering process. Calculated for metallic (silver and gold) and insulating ( SiO2 and MgO) nanoplatelets, radiative features are revealed above the main surface-plasmon-polariton peak, and dramatic enhancements in the electron-energy-loss probability at gaps of the “classical” spectra are found. The corresponding radiation should be detectable in the vacuum far-field zone, with e beams exploited as sensitive “tip detectors” of electronically excited nanostructures.

  6. Nanoscopic surfactant behavior of the porin MspA in aqueous media

    Directory of Open Access Journals (Sweden)

    Ayomi S. Perera

    2013-04-01

    Full Text Available The mycobacterial porin MspA is one of the most stable channel proteins known to date. MspA forms vesicles at low concentrations in aqueous buffers. Evidence from dynamic light scattering, transmission electron microscopy and zeta-potential measurements by electrophoretic light scattering indicate that MspA behaves like a nanoscale surfactant. The extreme thermostability of MspA allows these investigations to be carried out at temperatures as high as 343 K, at which most other proteins would quickly denature. The principles of vesicle formation of MspA as a function of temperature and the underlying thermodynamic factors are discussed here. The results obtained provide crucial evidence in support of the hypothesis that, during vesicle formation, nanoscopic surfactant molecules, such as MspA, deviate from the principles underlined in classical surface chemistry.

  7. Novel mechanisms for self-assembled pattern formation in nanoscopic metal films

    Science.gov (United States)

    Kalyanaraman, R.; Trice, J.; Favazza, C.; Thomas, D.; Sureshkumar, R.

    2007-03-01

    Classical hydrodynamic theory of dewetting of spinodally unstable thin films (Vrij, Disc. farad. Soc. 1966) predicts a monotonic increase in patterning length scales with increasing film thickness. We verified this effect for nanoscopic Co metal films following melting by ns laser pulses for thickness regime hFavazza et al. Nanotechnology, 2006). However, a dramatic change is observed beyond this thickness hc, with length scales decreasing with increasing h. This novel behavior arises from strong thickness dependence of heating by ultrafast laser light resulting in thermocapillary effects, whose magnitude and sign are thickness dependent. We modified the classical theory, according to which the instability occurs when the stabilizing capillary force is overcome by destabilizing attractive long-range interactions, to include thermocapillary effects. The modified theory accurately predicts the experimentally observed trend. This result suggests that a variety of new length scales can be accessed by robust self-assembly via dewetting of metal films under ultrafast light.

  8. Nanoscopic morphological changes in yeast cell surfaces caused by oxidative stress: an atomic force microscopic study.

    Science.gov (United States)

    Canetta, Elisabetta; Walker, Graeme M; Adya, Ashok K

    2009-06-01

    Nanoscopic changes in the cell surface morphology of the yeasts Saccharomyces cerevisiae (strain NCYC 1681) and Schizosaccharomyces pombe (strain DVPB 1354), due to their exposure to varying concentrations of hydrogen peroxide (oxidative stress), were investigated using an atomic force microscope (AFM). Increasing hydrogen peroxide concentration led to a decrease in cell viabilities and mean cell volumes, and an increase in the surface roughness of the yeasts. In addition, AFM studies revealed that oxidative stress caused cell compression in both S. cerevisiae and Schiz. pombe cells and an increase in the number of aged yeasts. These results confirmed the importance and usefulness of AFM in investigating the morphology of stressed microbial cells at the nanoscale. The results also provided novel information on the relative oxidative stress tolerance of S. cerevisiae and Schiz. pombe.

  9. The influence of nanoscopically thin silver films on bacterial viability and attachment.

    Science.gov (United States)

    Ivanova, Elena P; Hasan, Jafar; Truong, Vi Khanh; Wang, James Y; Raveggi, Massimo; Fluke, Christopher; Crawford, Russell J

    2011-08-01

    The physicochemical and bactericidal properties of thin silver films have been analysed. Silver films of 3 and 150 nm thicknesses were fabricated using a magnetron sputtering thin-film deposition system. X-ray photoelectron and energy dispersive X-ray spectroscopy and atomic force microscopy analyses confirmed that the resulting surfaces were homogeneous, and that silver was the most abundant element present on both surfaces, being 45 and 53 at.% on the 3- and 150-nm films, respectively. Inductively coupled plasma time of flight mass spectroscopy (ICP-TOF-MS) was used to measure the concentration of silver ions released from these films. Concentrations of 0.9 and 5.2 ppb were detected for the 3- and 150-nm films, respectively. The surface wettability of the films remained nearly identical for both film thicknesses, displaying a static water contact angle of 95°, while the surface free energy of the 150-nm film was found to be slightly greater than that of the 3-nm film, being 28.8 and 23.9 mN m(-1), respectively. The two silver film thicknesses exhibited statistically significant differences in surface topographic profiles on the nanoscopic scale, with R (a), R (q) and R (max) values of 1.4, 1.8 and 15.4 nm for the 3-nm film and 0.8, 1.2 and 10.7 nm for the 150-nm film over a 5 × 5 μm scanning area. Confocal scanning laser microscopy and scanning electron microscopy revealed that the bactericidal activity of the 3-nm silver film was not significant, whereas the nanoscopically smoother 150-nm silver film exhibited appreciable bactericidal activity towards Pseudomonas aeruginosa ATCC 9027 cells and Staphylococcus aureus CIP 65.8 cells, obtaining up to 75% and 27% sterilisation effect, respectively.

  10. Creating flat design websites

    CERN Document Server

    Pratas, Antonio

    2014-01-01

    This book contains practical, step-by-step tutorials along with plenty of explanation about designing your flat website. Each section is introduced sequentially, building up your web design skills and completing your website.Creating Flat Design Websites is ideal for you if you are starting on your web development journey, but this book will also benefit seasoned developers wanting to start developing in flat.

  11. Efficient photocatalytic degradation of gaseous N,N-dimethylformamide in tannery waste gas using doubly open-ended Ag/TiO2 nanotube array membranes

    Science.gov (United States)

    Zhao, Yang; Ma, Lin; Chang, Wenkai; Huang, Zhiding; Feng, Xugen; Qi, Xiaoxia; Li, Zenghe

    2018-06-01

    Gaseous N,N-dimethylformamide (DMF), typical volatile organic compound exhausted from manufacturing factories, may damage the health of workers under long-term exposure even at low levels. The defined geometry, porous surface and highly ordered channels make the free-standing anodic TiO2 nanotube (TiNT) arrays particularly suitable for applications of practical air purification by flow-through photocatalysis. In the present work, crystallized doubly open-ended Ag/TiNT array membranes were designed and prepared by employing a lift-off process based on an anodization-annealing-anodization-etching sequence, followed by uniform Ag nanoparticles decoration. For the photocatalytic degradation of gaseous DMF at low concentration levels close to that found in realistic pollutant air, an analytical methodology for the monitoring and determination of degradation process was developed based on the coupling of headspace sampling with gas chromatography mass spectrometry (HS-GC-MS). The doubly open-ended Ag/TiNT arrays exhibited higher removal efficiency of gaseous DMF from air compared with conventional bottom-closed Ag/TiNT arrays and pure bottomless TiNT arrays. These results indicated that the photocatalytic properties of TiNT arrays were improved with the open-bottom morphology and the Ag nanoparticles decoration. Based on the analysis with GC-MS and high performance ion chromatography (HPIC), it was found that demethylation is the main pathway of DMF degradation in photocatalytic reactions. Furthermore, decontamination of actual polluted tannery waste gas collected in leather factory proved that the photocatalysis on doubly open-ended Ag/TiNT array membrane is an efficient way and a promising application to treat air contaminated by DMF despite the complexity of various volatile organic compounds.

  12. Nitrate supplementation improves physical performance specifically in non-athletes during prolonged open-ended tests: a systematic review and meta-analysis.

    Science.gov (United States)

    Campos, Helton O; Drummond, Lucas R; Rodrigues, Quezia T; Machado, Frederico S M; Pires, Washington; Wanner, Samuel P; Coimbra, Cândido C

    2018-03-01

    Nitrate (NO3 -) is an ergogenic nutritional supplement that is widely used to improve physical performance. However, the effectiveness of NO3 - supplementation has not been systematically investigated in individuals with different physical fitness levels. The present study analysed whether different fitness levels (non-athletes v. athletes or classification of performance levels), duration of the test used to measure performance (short v. long duration) and the test protocol (time trials v. open-ended tests v. graded-exercise tests) influence the effects of NO3 - supplementation on performance. This systematic review and meta-analysis was conducted and reported according to the guidelines outlined in the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) statement. A systematic search of electronic databases, including PubMed, Web of Science, SPORTDiscus and ProQuest, was performed in August 2017. On the basis of the search and inclusion criteria, fifty-four and fifty-three placebo-controlled studies evaluating the effects of NO3 - supplementation on performance in humans were included in the systematic review and meta-analysis, respectively. NO3 - supplementation was ergogenic in non-athletes (mean effect size (ES) 0·25; 95 % CI 0·11, 0·38), particularly in evaluations of performance using long-duration open-ended tests (ES 0·47; 95 % CI 0·23, 0·71). In contrast, NO3 - supplementation did not enhance the performance of athletes (ES 0·04; 95 % CI -0·05, 0·15). After objectively classifying the participants into different performance levels, the frequency of trials showing ergogenic effects in individuals classified at lower levels was higher than that in individuals classified at higher levels. Thus, the present study indicates that dietary NO3 - supplementation improves physical performance in non-athletes, particularly during long-duration open-ended tests.

  13. Observation of enhanced electric field in an RF-plugged sheet plasma in the RFC-XX-M open-ended machine

    International Nuclear Information System (INIS)

    Oda, T.; Takiyama, K.; Kadota, K.

    1987-12-01

    We report nonperturbing observation of the electric field in the sheet plasma for RF end-plugging on the RFC XX-M open-ended machine by using the Stark effect with a combined technique of beam-probe and laser-induced fluorescence. Under the optimum condition for the RF plugging, enhanced electric field is found in the sheet plasma by about 2.5 times with respect to the electric field when no plasma is produced. The field spatial profile is also measured, which is discussed in connection with the electrostatic eigenmode. (author)

  14. The Effect of Reading Involvement through Open-Ended Strategy vs. Fill-in- the- Blanks Strategy on Young EFL Learners’ Reading Comprehension Ability

    Directory of Open Access Journals (Sweden)

    Rita Salehi Sepehr

    2014-11-01

    Full Text Available The present study investigated the extent to which an instructional framework of integrating strategy instruction (open-ended strategy and fill-in-the blanks strategy with motivation- support affected on reading result for young EFL learners. The central area of exploration included a comparison among three approaches to reading instruction: First, fill-in-the blanks strategy intervention; second, open-ended strategy intervention; and last, a control group which received the conventional reading strategies. The participants were sampled from amongst a group of seventy-seven pre-intermediate EFL learners in a language school in Tehran- Iran based on convenient sampling technique. For the sake of measurement, the researchers administered PET and CELT along with reading strategy based-test to quantify the participants’ current level of knowledge as well as the degree of achievement after treatment. For measurement’s sake, different types of tests such as PET, reading comprehension test (CELT, and reading strategy based- test were employed to quantify the participants’ current level of knowledge as well as the degree of achievement before and after instruction. The result of the present study indicated that the experimental groups had a significant improvement over the control group. Also, the level of learners’ reading engagement during classroom work mediated the instructional effects on reading outcomes. The results of this study can be to the benefit of both EFL and ESL teachers to teach reading comprehension using the student's critical mind as well as critical involvement in the reading tasks.

  15. Nanoscopic diffusion studies on III-V compound semiconductor structures: Experiment and theory

    Science.gov (United States)

    Gonzalez Debs, Mariam

    The electronic structure of multilayer semiconductor heterostructures is affected by the detailed compositional profiles throughout the structure and at critical interfaces. The extent of interdiffusion across these interfaces places limits on both the processing time and temperatures for many applications based on the resultant compositional profile and associated electronic structure. Atomic and phenomenological methods were used in this work through the combination of experiment and theory to understand the nanoscopic mechanisms in complex heterostructures. Two principal studies were conducted. Tin diffusion in GaAs was studied by fitting complex experimental diffusion profiles to a phenomenological model which involved the diffusion of substitutional and interstitial dopant atoms. A methodology was developed combining both the atomistic model and the use of key features within these experimentally-obtained diffusion profiles to determine meaningful values of the transport and defect reaction rate parameters. Interdiffusion across AlSb/GaSb multi-quantum well interfaces was also studied. The chemical diffusion coefficient characterizing the AlSb/GaSb diffusion couple was quantitatively determined by fitting the observed photoluminescence (PL) peak shifts to the solution of the Schrodinger equation using a potential derived from the solution of the diffusion equation to quantify the interband transition energy shifts. First-principles calculations implementing Density Functional Theory were performed to study the thermochemistry of point defects as a function of local environment, allowing a direct comparison of interfacial and bulk diffusion phenomena within these nanoscopic structures. Significant differences were observed in the Ga and Al vacancy formation energies at the AlSb/GaSb interface when compared to bulk AlSb and GaSb with the largest change found for Al vacancies. The AlSb/GaSb structures were further studied using positron annihilation spectroscopy

  16. Far-field interaction of focused relativistic electron beams in electron energy loss spectroscopy of nanoscopic platelets

    OpenAIRE

    Itskovsky, M. A.; Cohen, H.; Maniv, T.

    2008-01-01

    A quantum mechanical scattering theory for relativistic, highly focused electron beams near nanoscopic platelets is presented, revealing a new excitation mechanism due to the electron wave scattering from the platelet edges. Radiative electromagnetic excitations within the light cone are shown to arise, allowed by the breakdown of momentum conservation along the beam axis in the inelastic scattering process. Calculated for metallic (silver and gold) and insulating (SiO2 and MgO) nanoplatelets...

  17. Diffusion of flexible, charged, nanoscopic molecules in solution: Size and pH dependence for PAMAM dendrimer

    Science.gov (United States)

    Maiti, Prabal K.; Bagchi, Biman

    2009-12-01

    In order to understand self-diffusion (D) of a charged, flexible, and porous nanoscopic molecule in water, we carry out very long, fully atomistic molecular dynamics simulation of PAMAM dendrimer up to eight generations in explicit salt water under varying pH. We find that while the radius of gyration (Rg) varies as N1/3, the self-diffusion constant (D ) scales, surprisingly, as N-α, with α =0.39 at high pH and 0.5 at neutral pH, indicating a dramatic breakdown of Stokes-Einstein relation for diffusion of charged nanoscopic molecules. The variation in D as a function of radius of gyration demonstrates the importance of treating water and ions explicitly in the diffusion process of a flexible nanoscopic molecule. In agreement with recent experiments, the self-diffusion constant increases with pH, revealing the importance of dielectric friction in the diffusion process. The shape of a dendrimer is found to fluctuate on a nanosecond time scale. We argue that this flexibility (and also the porosity) of the dendrimer may play an important role in determining the mean square displacement of the dendrimer and the breakdown of the Stokes-Einstein relation between diffusion constant and the radius.

  18. Flat-port connectors

    KAUST Repository

    Alrashed, Mohammed

    2017-05-26

    Disclosed are various embodiments for connectors used with electronic devices, such as input and/or output ports to connect peripheral equipment or accessories. More specifically, various flat-port are provided that can be used in place of standard connectors including, but not limited to, audio jacks and Universal Serial Bus (USB) ports. The flat-port connectors are an alternate connection design to replace the traditional receptacle port (female-port), making the device more sealed creation more dust and water resistant. It is unique in the way of using the outer surfaces of the device for the electrical connection between the ports. Flat-port design can allow the manufacture of extremely thin devices by eliminating the side ports slots that take a lot of space and contribute to the increase thickness of the device. The flat-port receptacle improves the overall appearance of the device and makes it more resistant to dust and water.

  19. Flat-space singletons

    International Nuclear Information System (INIS)

    Fronsdal, C.

    1987-01-01

    Singletons exist, as particles and as local fields, only in 3+2 de Sitter space. Their kinematical properties make them natural candidates for constituents of massless fields, and perhaps for quarks. It is interesting to find out how to describe this type of compositeness in flat space. A theory of interacting singleton fields in de Sitter space is now available, and in this paper we study the flat-space limit of the Green's functions of that theory. The flat-space limit is an autonomous theory of Green's functions, but is not an operator field theory. The three-point function is calculated and its flat-space limit is found to reveal glimpses of a physical interpretation. Causal and spectral properties are in accord with the tenets of axiomatic field theory. The theory is a generalization of local field theory, in which photons appear as composite objects although the physical S matrix is the same as in conventional QED

  20. Nanoscopic characterization of Pr2Zr2O7 at Zr sites

    International Nuclear Information System (INIS)

    Martinez, J.A.; Caracoche, M.C.; Rodriguez, A.M.; Rivas, P.C.; Bondioli, F.; Manfredini, T.; Ferrari, A.M.

    2005-01-01

    By using Perturbed Angular Correlation Spectroscopy, a suitable technique to explore internal fields at nanoscopic scale, the electric field gradients at Zr 4+ sites in the Pr 2 Zr 2 O 7 compound have been determined as a function of temperature. Three nonequivalent nanoconfigurations are present, which have been interpreted with the aid of point charge model calculations. Two of them correspond to pyrochlore - oxygen defective and perfect structures -, and the third one to the pyrochlore-related defect fluorite structure. The most abundant interaction is a disordered and fluctuating electric field gradient, which describes the oxygen defective pyrochlore. As temperature increases, its gradual and reversible transformation towards the perfect form is observed. Below 750 C the oxygen vacancies movement, which exhibits an activation energy of 0.14 eV, is assumed to be due to vacancies jumping among 48f equivalent sites. At higher temperatures the movement is interpreted as the fast diffusion of oxygen vacancies involving 48f and 8b sites, thus giving place to anionic disorder. The activation energy for this movement has been determined to be of 0.85 eV. (copyright 2005 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  1. Effective Debye length in closed nanoscopic systems: a competition between two length scales.

    Science.gov (United States)

    Tessier, Frédéric; Slater, Gary W

    2006-02-01

    The Poisson-Boltzmann equation (PBE) is widely employed in fields where the thermal motion of free ions is relevant, in particular in situations involving electrolytes in the vicinity of charged surfaces. The applications of this non-linear differential equation usually concern open systems (in osmotic equilibrium with an electrolyte reservoir, a semi-grand canonical ensemble), while solutions for closed systems (where the number of ions is fixed, a canonical ensemble) are either not appropriately distinguished from the former or are dismissed as a numerical calculation exercise. We consider herein the PBE for a confined, symmetric, univalent electrolyte and quantify how, in addition to the Debye length, its solution also depends on a second length scale, which embodies the contribution of ions by the surface (which may be significant in high surface-to-volume ratio micro- or nanofluidic capillaries). We thus establish that there are four distinct regimes for such systems, corresponding to the limits of the two parameters. We also show how the PBE in this case can be formulated in a familiar way by simply replacing the traditional Debye length by an effective Debye length, the value of which is obtained numerically from conservation conditions. But we also show that a simple expression for the value of the effective Debye length, obtained within a crude approximation, remains accurate even as the system size is reduced to nanoscopic dimensions, and well beyond the validity range typically associated with the solution of the PBE.

  2. The Origin of Nanoscopic Grooving on Vesicle Walls in Submarine Basaltic Glass: Implications for Nanotechnology

    Directory of Open Access Journals (Sweden)

    Jason E. French

    2009-01-01

    Full Text Available Dendritic networks of nanoscopic grooves measuring 50–75 nm wide by <50 nm deep occur on the walls of vesicles in the glassy margins of mid-ocean ridge pillow basalts worldwide. Until now, their exact origin and significance have remained unclear. Here we document examples of such grooved patterns on vesicle walls in rocks from beneath the North Atlantic Ocean, and give a fluid mechanical explanation for how they formed. According to this model, individual nanogrooves represent frozen viscous fingers of magmatic fluid that were injected into a thin spheroidal shell of hot glass surrounding each vesicle. The driving mechanism for this process is provided by previous numerical predictions of tangential tensile stress around some vesicles in glassy rocks upon cooling through the glass transition. The self-assembling nature of the dendritic nanogrooves, their small size, and overall complexity in form, are interesting from the standpoint of exploring new applications in the field of nanotechnology. Replicating such structures in the laboratory would compete with state-of-the-art nanolithography techniques, both in terms of pattern complexity and size, which would be useful in the fabrication of a variety of grooved nanodevices. Dendritic nanogrooving in SiO2 glass might be employed in the manufacturing of integrated circuits.

  3. Mid-point for open-ended income category and the effect of equivalence scales on the income-health relationship

    Directory of Open Access Journals (Sweden)

    Roger Keller Celeste

    2013-12-01

    Full Text Available To estimate the mid-point of an open-ended income category and to assess the impact of two equivalence scales on income-health associations. Data were obtained from the 2010 Brazilian Oral Health Survey ( Pesquisa Nacional de Saúde Bucal – SBBrasil 2010. Income was converted from categorical to two continuous variables ( per capita and equivalized for each mid-point. The median mid-point was R$ 14,523.50 and the mean, R$ 24,507.10. When per capita income was applied, 53% of the population were below the poverty line, compared with 15% with equivalized income. The magnitude of income-health associations was similar for continuous income, but categorized equivalized income tended to decrease the strength of association.

  4. Shifting investments strategy from equity funds to money market funds – the case of Romanian open - end fund market during the financial crisis

    Directory of Open Access Journals (Sweden)

    Radu, I.

    2012-01-01

    Full Text Available Mutual funds are one of the key suppliers of liquidity in Romanian capital market. This paper uses quarterly data on Romanian open-end funds starting with 2006 until 2010. We find that significant negative flows (outflows were registered beginning with the end of 2007 (equity funds, during 2008 (equity funds, balanced funds, other funds and bond funds in the last 2 quarters of the year and from 2009 to 2010 (in the case of money market funds. There is evidence that the changing market conditions attract differently the incoming flows in these mutual funds. This is the reason why such perturbations affect investors’ confidence for these investment vehicles and impose the reorientation of the investment funds and of their investors to other alternatives in order to preserve their capital.

  5. Mid-point for open-ended income category and the effect of equivalence scales on the income-health relationship.

    Science.gov (United States)

    Celeste, Roger Keller; Bastos, João Luiz

    2013-12-01

    To estimate the mid-point of an open-ended income category and to assess the impact of two equivalence scales on income-health associations. Data were obtained from the 2010 Brazilian Oral Health Survey (Pesquisa Nacional de Saúde Bucal--SBBrasil 2010). Income was converted from categorical to two continuous variables (per capita and equivalized) for each mid-point. The median mid-point was R$ 14,523.50 and the mean, R$ 24,507.10. When per capita income was applied, 53% of the population were below the poverty line, compared with 15% with equivalized income. The magnitude of income-health associations was similar for continuous income, but categorized equivalized income tended to decrease the strength of association.

  6. Rates of Return on Open-End Debt Investment Funds and Bank Deposits in Poland in the Years 1995–2015 – A Comparative Analysis

    Directory of Open Access Journals (Sweden)

    Dittmann Iwona

    2016-12-01

    Full Text Available This paper presents the results of a comparison of the rates of return on specific open-end debt investment funds in Poland with the rates of return on bank deposits, in light of different time horizons. A comparative analysis was conducted based on the quartiles of the empirical distributions of the rates of return on selected funds and bank deposits. The empirical distributions were obtained using a moving window of observation. The results were largely influenced by very high interest rates on bank deposits in Poland in the years 1995–2001 (in the case of the oldest funds, and by the boom in the bond market in the years 2011–2012 (for the youngest funds. The investment horizon turned out to be significant. The best and worst funds were identified.

  7. Dye-sensitized solar cells employing doubly or singly open-ended TiO2 nanotube arrays: structural geometry and charge transport.

    Science.gov (United States)

    Choi, Jongmin; Song, Seulki; Kang, Gyeongho; Park, Taiho

    2014-09-10

    We systematically investigated the charge transport properties of doubly or singly open-ended TiO2 nanotube arrays (DNT and SNT, respectively) for their utility as electrodes in dye-sensitized solar cells (DSCs). The SNT or DNT arrays were transferred in a bottom-up (B-up) or top-up (T-up) configuration onto a fluorine-doped tin oxide (FTO) substrate onto which had been deposited a 2 μm thick TiO2 nanoparticle (NP) interlayer. This process yielded four types of DSCs prepared with SNTs (B-up or T-up) or DNT (B-up or T-up). The photovoltaic performances of these DSCs were analyzed by measuring the dependence of the charge transport on the DSC geometry. High resolution scanning electron microscopy techniques were used to characterize the electrode cross sections, and electrochemical impedance spectroscopy was used to characterize the electrical connection at the interface between the NT array and the TiO2 NP interlayer. We examined the effects of decorating the DNT or SNT arrays with small NPs (sNP@DNT and sNP@SNT, respectively) in an effort to increase the extent of dye loading. The DNT arrays decorated with small NPs performed better than the decorated SNT arrays, most likely because the Ti(OH)4 precursor solution flowed freely into the array through the open ends of the NTs in the DNT case but not in the SNT case. The sNP@DNT-based DSC exhibited a better PCE (10%) compared to the sNP@SNT-based DSCs (6.8%) because the electrolyte solution flow was not restricted, direct electron transport though the NT arrays was possible, the electrical connection at the interface between the NT array and the TiO2 NP interlayer was good, and the array provided efficient light harvesting.

  8. Rocky Flats Compliance Program

    International Nuclear Information System (INIS)

    1994-02-01

    The Department of Energy (DOE) established the Office of Technology Development (EM-50) (OTD) as an element of Environmental Restoration and Waste Management (EM) in November 1989. The primary objective of the Office of Technology Development, Rocky Flats Compliance Program (RFCP), is to develop altemative treatment technologies for mixed low-level waste (wastes containing both hazardous and radioactive components) to use in bringing the Rocky Flats Plant (RFP) into compliance with Federal and state regulations and agreements. Approximately 48,000 cubic feet of untreated low-level mixed waste, for which treatment has not been specified, are stored at the RFP. The cleanup of the Rocky Flats site is driven by agreements between DOE, the Environmental Protection Agency (EPA), and the Colorado Department of Health (CDH). Under these agreements, a Comprehensive Treatment and Management Plan (CTMP) was drafted to outline the mechanisms by which RFP will achieve compliance with the regulations and agreements. This document describes DOE's strategy to treat low-level mixed waste to meet Land Disposal Restrictions and sets specific milestones related to the regulatory aspects of technology development. These milestones detail schedules for the development of technologies to treat all of the mixed wastes at the RFP. Under the Federal Facilities Compliance Act (FFCA), the CTMP has been incorporated into Rocky Flats Plant Conceptual Site Treatment Plan (CSTP). The CSTP will become the Rocky Flats Plant site Treatment Plan in 1995 and will supersede the CTMP

  9. Equilibrium state of a cylindrical particle with flat ends in nematic liquid crystals.

    Science.gov (United States)

    Hashemi, S Masoomeh; Ejtehadi, Mohammad Reza

    2015-01-01

    A continuum theory is employed to numerically study the equilibrium orientation and defect structures of a circular cylindrical particle with flat ends under a homeotropic anchoring condition in a uniform nematic medium. Different aspect ratios of this colloidal geometry from thin discotic to long rodlike shapes and several colloidal length scales ranging from mesoscale to nanoscale are investigated. We show that the equilibrium state of this colloidal geometry is sensitive to the two geometrical parameters: aspect ratio and length scale of the particle. For a large enough mesoscopic particle, there is a specific asymptotic equilibrium angle associated to each aspect ratio. Upon reducing the particle size to nanoscale, the equilibrium angle follows a descending or ascending trend in such a way that the equilibrium angle of a particle with the aspect ratio bigger than 1:1 (a discotic particle) goes to a parallel alignment with respect to the far-field nematic, whereas the equilibrium angle for a particle with the aspect ratio 1:1 and smaller (a rodlike particle) tends toward a perpendicular alignment to the uniform nematic direction. The discrepancy between the equilibrium angles of the mesoscopic and nanoscopic particles originates from the significant differences between their defect structures. The possible defect structures related to mesoscopic and nanoscopic colloidal particles of this geometry are also introduced.

  10. Evidence-based nanoscopic and molecular framework for excipient functionality in compressed orally disintegrating tablets.

    Directory of Open Access Journals (Sweden)

    Ali Al-Khattawi

    Full Text Available The work investigates the adhesive/cohesive molecular and physical interactions together with nanoscopic features of commonly used orally disintegrating tablet (ODT excipients microcrystalline cellulose (MCC and D-mannitol. This helps to elucidate the underlying physico-chemical and mechanical mechanisms responsible for powder densification and optimum product functionality. Atomic force microscopy (AFM contact mode analysis was performed to measure nano-adhesion forces and surface energies between excipient-drug particles (6-10 different particles per each pair. Moreover, surface topography images (100 nm2-10 µm2 and roughness data were acquired from AFM tapping mode. AFM data were related to ODT macro/microscopic properties obtained from SEM, FTIR, XRD, thermal analysis using DSC and TGA, disintegration testing, Heckel and tabletability profiles. The study results showed a good association between the adhesive molecular and physical forces of paired particles and the resultant densification mechanisms responsible for mechanical strength of tablets. MCC micro roughness was 3 times that of D-mannitol which explains the high hardness of MCC ODTs due to mechanical interlocking. Hydrogen bonding between MCC particles could not be established from both AFM and FTIR solid state investigation. On the contrary, D-mannitol produced fragile ODTs due to fragmentation of surface crystallites during compression attained from its weak crystal structure. Furthermore, AFM analysis has shown the presence of extensive micro fibril structures inhabiting nano pores which further supports the use of MCC as a disintegrant. Overall, excipients (and model drugs showed mechanistic behaviour on the nano/micro scale that could be related to the functionality of materials on the macro scale.

  11. Evidence-Based Nanoscopic and Molecular Framework for Excipient Functionality in Compressed Orally Disintegrating Tablets

    Science.gov (United States)

    Al-khattawi, Ali; Alyami, Hamad; Townsend, Bill; Ma, Xianghong; Mohammed, Afzal R.

    2014-01-01

    The work investigates the adhesive/cohesive molecular and physical interactions together with nanoscopic features of commonly used orally disintegrating tablet (ODT) excipients microcrystalline cellulose (MCC) and D-mannitol. This helps to elucidate the underlying physico-chemical and mechanical mechanisms responsible for powder densification and optimum product functionality. Atomic force microscopy (AFM) contact mode analysis was performed to measure nano-adhesion forces and surface energies between excipient-drug particles (6-10 different particles per each pair). Moreover, surface topography images (100 nm2–10 µm2) and roughness data were acquired from AFM tapping mode. AFM data were related to ODT macro/microscopic properties obtained from SEM, FTIR, XRD, thermal analysis using DSC and TGA, disintegration testing, Heckel and tabletability profiles. The study results showed a good association between the adhesive molecular and physical forces of paired particles and the resultant densification mechanisms responsible for mechanical strength of tablets. MCC micro roughness was 3 times that of D-mannitol which explains the high hardness of MCC ODTs due to mechanical interlocking. Hydrogen bonding between MCC particles could not be established from both AFM and FTIR solid state investigation. On the contrary, D-mannitol produced fragile ODTs due to fragmentation of surface crystallites during compression attained from its weak crystal structure. Furthermore, AFM analysis has shown the presence of extensive micro fibril structures inhabiting nano pores which further supports the use of MCC as a disintegrant. Overall, excipients (and model drugs) showed mechanistic behaviour on the nano/micro scale that could be related to the functionality of materials on the macro scale. PMID:25025427

  12. Flat-port connectors

    KAUST Repository

    Alrashed, Mohammed

    2017-01-01

    and water resistant. It is unique in the way of using the outer surfaces of the device for the electrical connection between the ports. Flat-port design can allow the manufacture of extremely thin devices by eliminating the side ports slots that take a lot

  13. Piecewise flat gravitational waves

    NARCIS (Netherlands)

    van de Meent, M.

    2011-01-01

    We examine the continuum limit of the piecewise flat locally finite gravity model introduced by ’t Hooft. In the linear weak field limit, we find the energy–momentum tensor and metric perturbation of an arbitrary configuration of defects. The energy–momentum turns out to be restricted to satisfy

  14. Flat out and bluesome

    OpenAIRE

    Wilson, Mark; Snaebjornsdottir, Bryndis; Byatt, Lucy

    2008-01-01

    ‘Nanoq: flat out and bluesome’ is the story of polar bears, the largest land predators on earth, and their journey from the arctic wilderness to the museums and stately homes of the UK. The work documents the histories of each of these bears, the legacies of the hunters who shot them and the skills and expertise of the taxidermists who stuffed them.

  15. Nanoscopic X-ray fluorescence imaging and quantification of intracellular key-elements in cryofrozen Friedreich's ataxia fibroblasts.

    Directory of Open Access Journals (Sweden)

    Björn De Samber

    Full Text Available Synchrotron radiation based nanoscopic X-ray fluorescence (SR nano-XRF analysis can visualize trace level elemental distribution in a fully quantitative manner within single cells. However, in-air XRF analysis requires chemical fixation modifying the cell's chemical composition. Here, we describe first nanoscopic XRF analysis upon cryogenically frozen (-150°C fibroblasts at the ID16A-NI 'Nano-imaging' end-station located at the European Synchrotron Radiation Facility (ESRF in Grenoble (France. Fibroblast cells were obtained from skin biopsies from control and Friedreich's ataxia (FRDA patients. FRDA is an autosomal recessive disorder with dysregulation of iron metabolism as a key feature. By means of the X-ray Fundamental Parameter (FP method, including absorption correction of the ice layer deposited onto the fibroblasts, background-corrected mass fraction elemental maps of P, S, Cl, K, Ca, Fe and Zn of entire cryofrozen human fibroblasts were obtained. Despite the presence of diffracting microcrystals in the vitreous ice matrix and minor sample radiation damage effects, clusters of iron-rich hot-spots with similar mass fractions were found in the cytoplasm of both control and FRDA fibroblasts. Interestingly, no significant difference in the mean iron concentration was found in the cytoplasm of FRDA fibroblasts, but a significant decrease in zinc concentration. This finding might underscore metal dysregulation, beyond iron, in cells derived from FRDA patients. In conclusion, although currently having slightly increased limits of detection (LODs compared to non-cryogenic mode, SR based nanoscopic XRF under cryogenic sample conditions largely obliterates the debate on chemical sample preservation and provides a unique tool for trace level elemental imaging in single cells close to their native state with a superior spatial resolution of 20 nm.

  16. Contribution of Adsorbed Protein Films to Nanoscopic Vibrations Exhibited by Bacteria Adhering through Ligand-Receptor Bonds.

    Science.gov (United States)

    Song, Lei; Sjollema, Jelmer; Norde, Willem; Busscher, Henk J; van der Mei, Henny C

    2015-09-29

    Bacteria adhering to surfaces exhibit nanoscopic vibrations that depend on the viscoelasticity of the bond. The quantification of the nanoscopic vibrations of bacteria adhering to surfaces provides new opportunities to better understand the properties of the bond through which bacteria adhere and the mechanisms by which they resist detachment. Often, however, bacteria do not adhere to bare surfaces but to adsorbed protein films, on which adhesion involves highly specific ligand-receptor binding next to nonspecific DLVO interaction forces. Here we determine the contribution of adsorbed salivary protein and fibronectin films to vibrations exhibited by adhering streptococci and staphylococci, respectively. The streptococcal strain used has the ability to adhere to adsorbed salivary proteins films through antigen I/II ligand-receptor binding, while the staphylococcal strain used adheres to adsorbed fibronectin films through a proteinaceous ligand-receptor bond. In the absence of ligand-receptor binding, electrostatic interactions had a large impact on vibration amplitudes of adhering bacteria on glass. On an adsorbed salivary protein film, vibration amplitudes of adhering streptococci depended on the film softness as determined by QCM-D and were reduced after film fixation using glutaraldehyde. On a relatively stiff fibronectin film, cross-linking the film in glutaraldehyde hardly reduced its softness, and accordingly fibronectin film softness did not contribute to vibration amplitudes of adhering staphylococci. However, fixation of the staphylococcus-fibronectin bond further decreased vibration amplitudes, while fixation of the streptococcus bond hardly impacted vibration amplitudes. Summarizing, this study shows that both the softness of adsorbed protein films and the properties of the bond between an adhering bacterium and an adsorbed protein film play an important role in bacterial vibration amplitudes. These nanoscopic vibrations reflect the viscoelasticity of the

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

    Science.gov (United States)

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

    2017-12-01

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

  18. Perceived Effects of Pornography on the Couple Relationship: Initial Findings of Open-Ended, Participant-Informed, "Bottom-Up" Research.

    Science.gov (United States)

    Kohut, Taylor; Fisher, William A; Campbell, Lorne

    2017-02-01

    The current study adopted a participant-informed, "bottom-up," qualitative approach to identifying perceived effects of pornography on the couple relationship. A large sample (N = 430) of men and women in heterosexual relationships in which pornography was used by at least one partner was recruited through online (e.g., Facebook, Twitter, etc.) and offline (e.g., newspapers, radio, etc.) sources. Participants responded to open-ended questions regarding perceived consequences of pornography use for each couple member and for their relationship in the context of an online survey. In the current sample of respondents, "no negative effects" was the most commonly reported impact of pornography use. Among remaining responses, positive perceived effects of pornography use on couple members and their relationship (e.g., improved sexual communication, more sexual experimentation, enhanced sexual comfort) were reported frequently; negative perceived effects of pornography (e.g., unrealistic expectations, decreased sexual interest in partner, increased insecurity) were also reported, albeit with considerably less frequency. The results of this work suggest new research directions that require more systematic attention.

  19. The Knowledge, Awareness, and Practices of Portuguese General Practitioners Regarding Multimorbidity and its Management: Qualitative Perspectives from Open-Ended Questions

    Directory of Open Access Journals (Sweden)

    Filipe Prazeres

    2016-11-01

    Full Text Available Multimorbidity’s high prevalence and negative impact has made it a subject of worldwide interest. The main aim of this study was to access the Portuguese knowledge, awareness, and practices of general practitioners (GPs regarding multimorbidity and its management, in order to aid in the development of interventions for improving outcomes in multimorbid patients in primary care. A web-based qualitative descriptive study was carried out in the first trimester of 2016 with primary care physicians working in two districts of the Centre region of Portugal. Open-ended questions were analysed via inductive thematic content analysis. GPs pointed out several difficulties and challenges while managing multimorbidity. Extrinsic factors were associated with the healthcare system logistics’ management (consultation time, organization of care teams, clinical information and society (media pressure, social/family support. Intrinsic factors related to the GP, patient, and physician-patient relationship were also stated. The most significant conclusion to emerge from this study is that although GPs perceived difficulties and challenges towards multimorbidity, they also have the tools to deal with them: the fundamental characteristics of family medicine. Also, the complex care required by multimorbid patients needs adequate consultation time, multidisciplinary teamwork, and more education/training.

  20. The Knowledge, Awareness, and Practices of Portuguese General Practitioners Regarding Multimorbidity and its Management: Qualitative Perspectives from Open-Ended Questions.

    Science.gov (United States)

    Prazeres, Filipe; Santiago, Luiz

    2016-11-08

    Multimorbidity's high prevalence and negative impact has made it a subject of worldwide interest. The main aim of this study was to access the Portuguese knowledge, awareness, and practices of general practitioners (GPs) regarding multimorbidity and its management, in order to aid in the development of interventions for improving outcomes in multimorbid patients in primary care. A web-based qualitative descriptive study was carried out in the first trimester of 2016 with primary care physicians working in two districts of the Centre region of Portugal. Open-ended questions were analysed via inductive thematic content analysis. GPs pointed out several difficulties and challenges while managing multimorbidity. Extrinsic factors were associated with the healthcare system logistics' management (consultation time, organization of care teams, clinical information) and society (media pressure, social/family support). Intrinsic factors related to the GP, patient, and physician-patient relationship were also stated. The most significant conclusion to emerge from this study is that although GPs perceived difficulties and challenges towards multimorbidity, they also have the tools to deal with them: the fundamental characteristics of family medicine. Also, the complex care required by multimorbid patients needs adequate consultation time, multidisciplinary teamwork, and more education/training.

  1. The Use of Open-Ended Problem-Based Learning Scenarios in an Interdisciplinary Biotechnology Class: Evaluation of a Problem-Based Learning Course Across Three Years

    Directory of Open Access Journals (Sweden)

    Todd R. Steck

    2012-02-01

    Full Text Available Use of open-ended Problem-Based Learning (PBL in biology classrooms has been limited by the difficulty in designing problem scenarios such that the content learned in a course can be predicted and controlled, the lack of familiarity of this method of instruction by faculty, and the difficulty in assessment. Here we present the results of a study in which we developed a team-based interdisciplinary course that combined the fields of biology and civil engineering across three years. We used PBL scenarios as the only learning tool, wrote the problem scenarios, and developed the means to assess these courses and the results of that assessment. Our data indicates that PBL changed students’ perception of their learning in content knowledge and promoted a change in students’ learning styles. Although no  statistically significant improvement in problem-solving skills and critical thinking skills was observed, students reported substantial changes in their problem-based learning strategies and critical thinking skills.

  2. Views from Within a Narrative: Evaluating Long-Term Human-Robot Interaction in a Naturalistic Environment Using Open-Ended Scenarios.

    Science.gov (United States)

    Syrdal, Dag Sverre; Dautenhahn, Kerstin; Koay, Kheng Lee; Ho, Wan Ching

    2014-01-01

    This article describes the prototyping of human-robot interactions in the University of Hertfordshire (UH) Robot House. Twelve participants took part in a long-term study in which they interacted with robots in the UH Robot House once a week for a period of 10 weeks. A prototyping method using the narrative framing technique allowed participants to engage with the robots in episodic interactions that were framed using narrative to convey the impression of a continuous long-term interaction. The goal was to examine how participants responded to the scenarios and the robots as well as specific robot behaviours, such as agent migration and expressive behaviours. Evaluation of the robots and the scenarios were elicited using several measures, including the standardised System Usability Scale, an ad hoc Scenario Acceptance Scale, as well as single-item Likert scales, open-ended questionnaire items and a debriefing interview. Results suggest that participants felt that the use of this prototyping technique allowed them insight into the use of the robot, and that they accepted the use of the robot within the scenario.

  3. Exposure to thin-ideal media affect most, but not all, women: Results from the Perceived Effects of Media Exposure Scale and open-ended responses.

    Science.gov (United States)

    Frederick, David A; Daniels, Elizabeth A; Bates, Morgan E; Tylka, Tracy L

    2017-12-01

    Findings conflict as to whether thin-ideal media affect women's body satisfaction. Meta-analyses of experimental studies reveal small or null effects, but many women endorse appearance-related media pressure in surveys. Using a novel approach, two samples of women (Ns=656, 770) were exposed to bikini models, fashion models, or control conditions and reported the effects of the images their body image. Many women reported the fashion/bikini models made them feel worse about their stomachs (57%, 64%), weight (50%, 56%), waist (50%, 56%), overall appearance (50%, 56%), muscle tone (46%, 52%), legs (45%, 48%), thighs (40%, 49%), buttocks (40%, 43%), and hips (40%, 46%). In contrast, few women (1-6%) reported negative effects of control images. In open-ended responses, approximately one-third of women explicitly described negative media effects on their body image. Findings revealed that many women perceive negative effects of thin-ideal media in the immediate aftermath of exposures in experimental settings. Copyright © 2017 Elsevier Ltd. All rights reserved.

  4. [What is the situation with human rights of the elderly? : UN Open-ended Working Group on Ageing - review and prospects].

    Science.gov (United States)

    Mahler, Claudia

    2017-06-01

    In November 2010 the United Nations General Assembly set up a working group to strengthen the protection of human rights for older persons (UN Open-ended Working Group on Ageing) with the United Nations Resolution A/C.3/65/L.8/Rev.1. In December 2016 the members of the working group met for the seventh time and discussed how they can approach the fulfillment of the mandate. In addition to better implementation, the strengthening of rights can consist of closing existing gaps or further differentiation of the rights in order to give the member states better guidance on how to implement them. To improve the human rights of older persons a task of the members of the working group would be to examine the existing rights and, where possible, adjust them to the real needs of the group. One of the major challenges facing the working group is already apparent: who belongs to the group of older persons and how could the group be described? This article deals with the presentation of the international process, new developments at the regional level and the attitudes of the member states and the civil society. A further aim is to present the possibilities and effects of a comprehensive legally binding instrument.

  5. Flat feet in children

    Directory of Open Access Journals (Sweden)

    Vukašinović Zoran

    2009-01-01

    Full Text Available The authors describe flatfoot, as one of very frequent deformities in everyday medical practice. A special condition of the deformity associated with a calcaneal valgus position and complicated by a knee valgus position (as a consequence of non-treatment is described. Also, the precise anatomy of the longitudinal foot arches (medial and lateral, definition and classification of the deformity, clinical findings and therapeutic protocols are proposed. The authors especially emphasise that the need for having extensive knowledge on the differences between a flexible and rigid flatfoot, having in mind that the treatment of flexible flat foot is usually not necessary, while the treatment of rigid flatfoot is usually unavoidable.

  6. Ricci-flat branes

    International Nuclear Information System (INIS)

    Brecher, D.; Perry, M.J.

    2000-01-01

    Up to overall harmonic factors, the D8-brane solution of the massive type IIA supergravity theory is the product of nine-dimensional Minkowski space (the world-volume) with the real line (the transverse space). We show that the equations of motion allow for the world-volume metric to be generalised to an arbitrary Ricci-flat one. If this nine-dimensional Ricci-flat manifold admits Killing spinors, then the resulting solutions are supersymmetric and satisfy the usual Bogomol'nyi bound, although they preserve fewer than the usual one half of the supersymmetries. We describe the possible choices of such manifolds, elaborating on the connection between the existence of Killing spinors and the self-duality condition on the curvature two-form. Since the D8-brane is a domain wall in ten dimensions, we are led to consider the general case: domain walls in any supergravity theory. Similar considerations hold here also. Moreover, it is shown that the world-volume of any magnetic brane - of which the domain walls are a specific example - can be generalised in precisely the same way. The general class of supersymmetric solutions have gravitational instantons as their spatial sections. Some mention is made of the world-volume solitons of such branes

  7. Flat Engineered Multichannel Reflectors

    Directory of Open Access Journals (Sweden)

    V. S. Asadchy

    2017-09-01

    Full Text Available Recent advances in engineered gradient metasurfaces have enabled unprecedented opportunities for light manipulation using optically thin sheets, such as anomalous refraction, reflection, or focusing of an incident beam. Here, we introduce a concept of multichannel functional metasurfaces, which are able to control incoming and outgoing waves in a number of propagation directions simultaneously. In particular, we reveal a possibility to engineer multichannel reflectors. Under the assumption of reciprocity and energy conservation, we find that there exist three basic functionalities of such reflectors: specular, anomalous, and retroreflections. Multichannel response of a general flat reflector can be described by a combination of these functionalities. To demonstrate the potential of the introduced concept, we design and experimentally test three different multichannel reflectors: three- and five-channel retroreflectors and a three-channel power splitter. Furthermore, by extending the concept to reflectors supporting higher-order Floquet harmonics, we forecast the emergence of other multichannel flat devices, such as isolating mirrors, complex splitters, and multi-functional gratings.

  8. Flat Engineered Multichannel Reflectors

    Science.gov (United States)

    Asadchy, V. S.; Díaz-Rubio, A.; Tcvetkova, S. N.; Kwon, D.-H.; Elsakka, A.; Albooyeh, M.; Tretyakov, S. A.

    2017-07-01

    Recent advances in engineered gradient metasurfaces have enabled unprecedented opportunities for light manipulation using optically thin sheets, such as anomalous refraction, reflection, or focusing of an incident beam. Here, we introduce a concept of multichannel functional metasurfaces, which are able to control incoming and outgoing waves in a number of propagation directions simultaneously. In particular, we reveal a possibility to engineer multichannel reflectors. Under the assumption of reciprocity and energy conservation, we find that there exist three basic functionalities of such reflectors: specular, anomalous, and retroreflections. Multichannel response of a general flat reflector can be described by a combination of these functionalities. To demonstrate the potential of the introduced concept, we design and experimentally test three different multichannel reflectors: three- and five-channel retroreflectors and a three-channel power splitter. Furthermore, by extending the concept to reflectors supporting higher-order Floquet harmonics, we forecast the emergence of other multichannel flat devices, such as isolating mirrors, complex splitters, and multi-functional gratings.

  9. UVIS Flat Field Uniformity

    Science.gov (United States)

    Quijano, Jessica Kim

    2009-07-01

    The stability and uniformity of the low-frequency flat fields {L-flat} of the UVIS detector will be assessed by using multiple-pointing observations of the globular clusters 47 Tucanae {NGC104} and Omega Centauri {NGC5139}, thus imaging moderately dense stellar fields. By placing the same star over different portions of the detector and measuring relative changes in its brightness, it will be possible to determine local variations in the response of the UVIS detector. Based on previous experience with STIS and ACS, it is deemed that a total of 9 different pointings will suffice to provide adequate characterization of the flat field stability in any given band. For each filter to be tested, the baseline consists of 9 pointings in a 3X3 box pattern with dither steps of about 25% of the FOV, or 40.5", in either the x or y direction {useful also for CTE measurements, if needed in the future}. During SMOV, the complement of filters to be tested is limited to the following 6 filters: F225W, F275W, F336W, for Omega Cen, and F438W, F606W, and F814W for 47 Tuc. Three long exposures for each target are arranged such that the initial dither position is observed with the appropriate filters for that target within one orbit at a single pointing, so that filter-to-filter differences in the observed star positions can be checked. In addition to the 9 baseline exposures, two sets of short exposures will be taken:a} one short exposure will be taken of OmegaCen with each of the visible filters {F438W, F606W and F814W} in order to check the geometric distortion solution to be obtained with the data from proposal 11444;b} for each target, a single short exposure will be taken with each filter to facilitate the study of the PSF as a function of position on the detector by providing unsaturated images of sparsely-spaced bright stars.This proposal corresponds to Activity Description ID WF39. It should execute only after the following proposal has executed:WF21 - 11434

  10. Estimation of adsorption-induced pore pressure and confinement in a nanoscopic slit pore by a density functional theory

    Science.gov (United States)

    Grégoire, David; Malheiro, Carine; Miqueu, Christelle

    2018-03-01

    This study aims at characterising the adsorption-induced pore pressure and confinement in nanoscopic pores by molecular non-local density functional theory (DFT). Considering its important potential industrial applications, the adsorption of methane in graphitic slit pores has been selected as the test case. While retaining the accuracy of molecular simulations at pore scale, DFT has a very low computational cost that allows obtaining highly resolved pore pressure maps as a function of both pore width and thermodynamic conditions. The dependency of pore pressure on these parameters (pore width, pressure and temperature) is carefully analysed in order to highlight the effect of each parameter on the confined fluid properties that impact the solid matrix.

  11. [Characteristics of mental health problems among Japanese young workers and their measures--a cross-sectional survey using an open-ended questionnaire].

    Science.gov (United States)

    Ikegami, Kazunori; Eguchi, Masafumi; Osaki, Yohei; Nakao, Tomo; Nakamoto, Kengo; Hino, Ayako; Hiro, Hisanori

    2014-01-01

    The purpose of this study is to investigate the characteristics of mental health problems faced by young workers and the effectiveness of measures implemented for improving their mental health. We sent anonymous open-ended questionnaires to 386 occupational physicians in Japan, and received questionnaire responses from 109 of them. The questionnaire was comprised of two parts. The first part addressed the age-specific characteristics of workers with mental health problems. The second part focused on the mental health measures implemented for young workers and opinions on their effectiveness. The responses were entered in a database. Frequently appearing words were identified and the number of times of the appearance was counted for each question. We conducted statistical analysis to examine the association between word frequency and age group in the first part. Ten investigators and collaborators of this study arranged the descriptions of the mental health measures for young workers and the opinions on their effectiveness in the second part. For mentally ill subjects in their 20s, we identified a range of frequently occurring words using correspondence analysis. The frequently occurring words were: "personality", "immaturity", "extrapunitive", "developmental disorder", "schizophrenia," "new-type depression", "maladjustment", "entering a company", "society", "superior," and "co-worker", Work-related words, such as "qualitative workloads" and "quantitative workloads", were identified for those in their 30s, and greater numbers of words on life outside of the workplace, such as "home," "child" and "nursing care" were identified for those in their 40s. Among the responses about the types of measures implemented for young workers, education and interviews were most common, and most respondents indicated that the effectiveness of these measures was unknown. A few respondents indicated that coordination between young workers' families and the persons concerned in the

  12. Exact piecewise flat gravitational waves

    NARCIS (Netherlands)

    van de Meent, M.

    2011-01-01

    We generalize our previous linear result (van de Meent 2011 Class. Quantum Grav 28 075005) in obtaining gravitational waves from our piecewise flat model for gravity in 3+1 dimensions to exact piecewise flat configurations describing exact planar gravitational waves. We show explicitly how to

  13. Flat plate collector. Solarflachkollektor

    Energy Technology Data Exchange (ETDEWEB)

    Raab, N

    1979-03-29

    The invention refers to a flat solar collector with an absorber plate, which is arranged on a support and is covered by a transparent window, between which and the plate there is an air space. The previously known structures of this type had the disadvantage that the thermal expansion of the enclosed air caused considerable difficulties. The purpose of the invention is therefore to create a collector, which can be used on the modular system, retains its properties and is safe in spite of the great temperature variations. According to the invention this problem is solved by providing a compensating space in the collector, which is separated by a diaphragm from the airspace between the plate and the covering window. The airspace therefore remains sealed against the atmosphere, so that no dirt, corrosion of the inside and no condensation can reduce the efficiency of the collector. A rise in pressure due to an increase in temperature is immediately reduced by expansion of the diaphragm, which enters the compensation space. In order to increase the pressure in the airspace above the plate for increases in temperature, the compensation space is connected to the atmosphere. The diaphragm can be mirrored on the side towards the absorber, which makes the diaphragm into an insulating element, as it reflects radiated heat from the absorber.

  14. 40 CFR 230.42 - Mud flats.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 24 2010-07-01 2010-07-01 false Mud flats. 230.42 Section 230.42... Aquatic Sites § 230.42 Mud flats. (a) Mud flats are broad flat areas along the sea coast and in coastal rivers to the head of tidal influence and in inland lakes, ponds, and riverine systems. When mud flats...

  15. Flat slices in Minkowski space

    Science.gov (United States)

    Murchadha, Niall Ó.; Xie, Naqing

    2015-03-01

    Minkowski space, flat spacetime, with a distance measure in natural units of d{{s}2}=-d{{t}2}+d{{x}2}+d{{y}2}+d{{z}2}, or equivalently, with spacetime metric diag(-1, +1, +1, +1), is recognized as a fundamental arena for physics. The Poincaré group, the set of all rigid spacetime rotations and translations, is the symmetry group of Minkowski space. The action of this group preserves the form of the spacetime metric. Each t = constant slice of each preferred coordinate system is flat. We show that there are also nontrivial non-singular representations of Minkowski space with complete flat slices. If the embedding of the flat slices decays appropriately at infinity, the only flat slices are the standard ones. However, if we remove the decay condition, we find non-trivial flat slices with non-vanishing extrinsic curvature. We write out explicitly the coordinate transformation to a frame with such slices.

  16. Radioactive material defense construction using wind fan system against nuclear fallout in the aspect of nano-scopic dispersion

    International Nuclear Information System (INIS)

    Woo, Tae Ho

    2012-01-01

    Highlights: ► A realistic radiation protection system using aerodynamics is suggested. ► Manual formation procedure is constructed by this modeling. ► Chemical and natural accidents by wind fan are applicable. ► Nuclear disaster is avoided by national defense system. ► A sample case is realistically modeled. -- Abstract: Radioactive fallout defense system (RFDS) is suggested against possible nuclear accidents. A procedure consisting of several stages is considered. In particular, the dispersion of radioactive material is investigated for the case of wind fan operation where the radioactive molecules are considered as nano-scopic material. The modeling is done for one country dealing with a possible nuclear accident in another country. This study is thus applicable to regions where westerlies are prevailing. An aerodynamic fan analysis is performed. The incoming free wind stream is characterized by random sampling in Monte-Carlo simulation. The velocity of the fan is a critical aspect of the model. This model is applicable for volcanic ashes, nuclear bomb fallout, chemical material dispersion, and any other material combined with airflow. In addition, this fan could be studied, with nano-scale considerations, by a multi-scale technique.

  17. Nanoscopic designs of radiological protection in environmental scale for the Fukushima nuclear accident: Strategy by dispersion, dissolution, and filtration

    International Nuclear Information System (INIS)

    Woo, Tae Ho

    2016-01-01

    Highlights: • New kind of radiological protection concept is introduced. • The shielding concept is accompanied with the water spray system. • The solubility of radioactive material could be used for protection. • Practical method is suggested. • The system is variable by the random number quantities. - Abstract: The environmental defense system in the nuclear power plants (NPPs) is investigated in the aspect of the environmental scale incorporated with atmospheric and marine sectors. The object is to find the radiological protection protocol in the environmental scale which is different from the conventional three kinds of radiological protection principles. Conventional laboratory based principles are not applicable in the mass failure accident such as the case of Fukushima disaster. This newly introduced protocol has many useful applications for the nature treatment oriented methods where the atmospheric protection of dispersion and dissolution is performed first and the filtration of seawater would follow. The maximum and minimum values in fan velocity are about 7.5 m/s and 5.3 m/s respectively. For the spray system, the mole fractions by the water spray are shown where maximum and minimum values are 6.57 × 10 −17 and 8.84 × 10 −19 moles respectively. The maximum and minimum values of discharged values in filtration are 99.4 and 1.3 square velocity (m/s), respectively. The total and general radiological protection concept is suggested in the nanoscopic molecular scale performance.

  18. Wetting of flat gradient surfaces.

    Science.gov (United States)

    Bormashenko, Edward

    2018-04-01

    Gradient, chemically modified, flat surfaces enable directed transport of droplets. Calculation of apparent contact angles inherent for gradient surfaces is challenging even for atomically flat ones. Wetting of gradient, flat solid surfaces is treated within the variational approach, under which the contact line is free to move along the substrate. Transversality conditions of the variational problem give rise to the generalized Young equation valid for gradient solid surfaces. The apparent (equilibrium) contact angle of a droplet, placed on a gradient surface depends on the radius of the contact line and the values of derivatives of interfacial tensions. The linear approximation of the problem is considered. It is demonstrated that the contact angle hysteresis is inevitable on gradient surfaces. Electrowetting of gradient surfaces is discussed. Copyright © 2018 Elsevier Inc. All rights reserved.

  19. Soil decontamination at Rocky Flats

    International Nuclear Information System (INIS)

    Olsen, R.L.; Hayden, J.A.; Alford, C.E.; Kochen, R.L.; Stevens, J.R.

    1979-01-01

    A soils decontamination project was initiated, to remove actinides from soils at Rocky Flats. Wet screening, attrition scrubbing with Calgon at high pH, attrition scrubbing at low pH, and cationic flotation were investigated. Pilot plant studies were carried out. Conceptual designs have been generated for mounting the process in semi-trailers

  20. Individual energy savings for individual flats in blocks of flats

    DEFF Research Database (Denmark)

    Nielsen, Anker; Rose, Jørgen

    2014-01-01

    and 1980. Normally, we expect the reduction in energy consumption to be around 20% for a 2 °C lower temperature, but for an inner flat the reduction can be up to 71%. The owners of the adjoining flats get an increase in energy demand of 10 to 20% each. They will not be able to figure out whether...... this is because the neighbour maintains a low temperature or the fact that they maintain a higher temperature. The best solution is to keep your own indoor temperature low. We can also turn the problem around: if you maintain a higher temperature than your neighbours, then you will pay part of their heating bill....

  1. Laser illuminated flat panel display

    Energy Technology Data Exchange (ETDEWEB)

    Veligdan, J.T.

    1995-12-31

    A 10 inch laser illuminated flat panel Planar Optic Display (POD) screen has been constructed and tested. This POD screen technology is an entirely new concept in display technology. Although the initial display is flat and made of glass, this technology lends itself to applications where a plastic display might be wrapped around the viewer. The display screen is comprised of hundreds of planar optical waveguides where each glass waveguide represents a vertical line of resolution. A black cladding layer, having a lower index of refraction, is placed between each waveguide layer. Since the cladding makes the screen surface black, the contrast is high. The prototype display is 9 inches wide by 5 inches high and approximately I inch thick. A 3 milliwatt HeNe laser is used as the illumination source and a vector scanning technique is employed.

  2. Polyurethane adhesives in flat roofs

    OpenAIRE

    Bogárová Markéta; Stodůlka Jindřich; Šuhajda Karel

    2017-01-01

    It is necessary to stabilize individual layers of flat roofs, mainly because of wind suction. Apart from anchoring and surcharge, these layers can be secured by bonding. At present gluing is an indispensable and widely used stabilization method. On our market we can found many types of adhesives, most widely used are based on polyurethane. This paper focuses on problematic about stabilization thermal insulation from expanded polystyrene to vapor barrier from bitumen. One of the main issues is...

  3. Flat space physics from holography

    International Nuclear Information System (INIS)

    Bousso, Raphael

    2004-01-01

    We point out that aspects of quantum mechanics can be derived from the holographic principle, using only a perturbative limit of classical general relativity. In flat space, the covariant entropy bound reduces to the Bekenstein bound. The latter does not contain Newton's constant and cannot operate via gravitational back reaction. Instead, it is protected by - and in this sense, predicts - the Heisenberg uncertainty principle. (author)

  4. Flat panel planar optic display

    Energy Technology Data Exchange (ETDEWEB)

    Veligdan, J.T. [Brookhaven National Lab., Upton, NY (United States). Dept. of Advanced Technology

    1994-11-01

    A prototype 10 inch flat panel Planar Optic Display, (POD), screen has been constructed and tested. This display screen is comprised of hundreds of planar optic class sheets bonded together with a cladding layer between each sheet where each glass sheet represents a vertical line of resolution. The display is 9 inches wide by 5 inches high and approximately 1 inch thick. A 3 milliwatt HeNe laser is used as the illumination source and a vector scanning technique is employed.

  5. A small flat fission chamber

    International Nuclear Information System (INIS)

    Li Yijun; Wang Dalun; Chen Suhe

    1999-01-01

    With fission materials of depleted uranium, natural uranium, enriched uranium, 239 Pu, and 237 Np, the authors have designed and made a series of small flat fission chamber. The authors narrated the construction of the fission chamber and its technological process of manufacture, and furthermore, the authors have measured and discussed the follow correct factor, self-absorption, boundary effect, threshold loss factor, bottom scatter and or so

  6. Residue management at Rocky Flats

    International Nuclear Information System (INIS)

    Olencz, J.

    1995-01-01

    Past plutonium production and manufacturing operations conducted at the Rocky Flats Environmental Technology Site (RFETS) produced a variety of plutonium-contaminated by-product materials. Residues are a category of these materials and were categorized as open-quotes materials in-processclose quotes to be recovered due to their inherent plutonium concentrations. In 1989 all RFETS plutonium production and manufacturing operations were curtailed. This report describes the management of plutonium bearing liquid and solid wastes

  7. Flat beams in the SLC

    International Nuclear Information System (INIS)

    Adolphsen, C.; Barklow, T.; Burke, D.; Decker, F.J.; Emma, P.; Hildreth, M.; Himel, T.; Krejcik, P.; Limberg, T.; Minty, M.

    1993-01-01

    The Stanford Linear Collider was designed to operate with round beams; horizontal and vertical emittance made equal in the damping rings. The main motivation was to facilitate the optical matching through beam lines with strong coupling elements like the solenoid spin rotator magnets and the SLC arcs. Tests in 1992 showed that open-quote flat close-quote beams with a vertical to horizontal emittance ratio of around 1/10 can be successfully delivered to the end of the linac. Techniques developed to measure and control the coupling of the SLC arcs allow These beams to be transported to the Interaction Point (IP). Before flat beams could be used for collisions with polarized electrons, a new method of rotating the electron spin orientation with vertical arc orbit bumps had to be developed. Early in the 1993 run, the SLC was switched to open-quote flat close-quote beam operation. Within a short time the peak luminosity of the previous running cycle was reached and then surpassed. The average daily luminosity is now a factor of about two higher than the best achieved last year. In the following the authors present an overview of the problems encountered and their solutions for different parts of the SLC

  8. Harmonic manifolds with minimal horospheres are flat

    Indian Academy of Sciences (India)

    Abstract. In this note we reprove the known theorem: Harmonic manifolds with minimal horospheres are flat. It turns out that our proof is simpler and more direct than the original one. We also reprove the theorem: Ricci flat harmonic manifolds are flat, which is generally affirmed by appealing to Cheeger–Gromov splitting ...

  9. Harmonic Manifolds with Minimal Horospheres are Flat

    Indian Academy of Sciences (India)

    In this note we reprove the known theorem: Harmonic manifolds with minimal horospheres are flat. It turns out that our proof is simpler and more direct than the original one. We also reprove the theorem: Ricci flat harmonic manifolds are flat, which is generally affirmed by appealing to Cheeger–Gromov splitting theorem.

  10. 49 CFR 231.6 - Flat cars.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Flat cars. 231.6 Section 231.6 Transportation... TRANSPORTATION RAILROAD SAFETY APPLIANCE STANDARDS § 231.6 Flat cars. (Cars with sides 12 inches or less above the floor may be equipped the same as flat cars.) (a) Hand brakes—(1) Number. Same as specified for...

  11. Trajectory Optimization for Differential Flat Systems

    OpenAIRE

    Kahina Louadj; Benjamas Panomruttanarug; Alexandre Carlos Brandao Ramos; Felix Mora-Camino

    2016-01-01

    International audience; The purpose of this communication is to investigate the applicability of Variational Calculus to the optimization of the operation of differentially flat systems. After introducingcharacteristic properties of differentially flat systems, the applicability of variational calculus to the optimization of flat output trajectories is displayed. Two illustrative examples are also presented.

  12. Flat panel display - Impurity doping technology for flat panel displays

    Energy Technology Data Exchange (ETDEWEB)

    Suzuki, Toshiharu [Advanced Technology Planning, Sumitomo Eaton Nova Corporation, SBS Tower 9F, 10-1, Yoga 4-chome, Setagaya-ku, 158-0097 Tokyo (Japan)]. E-mail: suzuki_tsh@senova.co.jp

    2005-08-01

    Features of the flat panel displays (FPDs) such as liquid crystal display (LCD) and organic light emitting diode (OLED) display, etc. using low temperature poly-Si (LTPS) thin film transistors (TFTs) are briefly reviewed comparing with other FPDs. The requirements for fabricating TFTs used for high performance FPDs and system on glass (SoG) are addressed. This paper focuses on the impurity doping technology, which is one of the key technologies together with crystallization by laser annealing, formation of high quality gate insulator and gate-insulator/poly-Si interface. The issues to be solved in impurity doping technology for state of the art and future TFTs are clarified.

  13. Flat panel display - Impurity doping technology for flat panel displays

    International Nuclear Information System (INIS)

    Suzuki, Toshiharu

    2005-01-01

    Features of the flat panel displays (FPDs) such as liquid crystal display (LCD) and organic light emitting diode (OLED) display, etc. using low temperature poly-Si (LTPS) thin film transistors (TFTs) are briefly reviewed comparing with other FPDs. The requirements for fabricating TFTs used for high performance FPDs and system on glass (SoG) are addressed. This paper focuses on the impurity doping technology, which is one of the key technologies together with crystallization by laser annealing, formation of high quality gate insulator and gate-insulator/poly-Si interface. The issues to be solved in impurity doping technology for state of the art and future TFTs are clarified

  14. The Ongoing and Open-Ended Simulation

    Science.gov (United States)

    Cohen, Alexander

    2016-01-01

    This case study explores a novel form of classroom simulation that differs from published examples in two important respects. First, it is ongoing. While most simulations represent a single learning episode embedded within a course, the ongoing simulation is a continuous set of interrelated events and decisions that accompany learning throughout…

  15. OPEN-ENDED NARRATIVE AND MORAL FORMATION

    African Journals Online (AJOL)

    Dr John Klaasen, Faculty of Arts Ethics, Religion and Theology Department .... worship, democratic models relate our innermost psychological depth with the broadest ... are discussed in some detail in my doctoral thesis entitled “The interplay.

  16. Reflections on a flat wall

    International Nuclear Information System (INIS)

    Stevenson, G.R.; Huhtinen, M.

    1995-01-01

    This paper describes an investigation into whether estimates of attenuation in the flat sidewalls of the tunnel for the MC main ring can be based on a simple point-source/line-of-sight model. Having seen the limitations of such a model, an alternative is proposed where the main radiation source is not the initial object struck by the beam but the plane source provided by the first interactions of secondaries from the target in the shield-wall. This is shown to have a closer relation to reality than the point-source/line-of-sight model. (author)

  17. Blowup for flat slow manifolds

    DEFF Research Database (Denmark)

    Kristiansen, Kristian Uldall

    2017-01-01

    In this paper, we present a way of extending the blowup method, in the formulation of Krupa and Szmolyan, to flat slow manifolds that lose hyperbolicity beyond any algebraic order. Although these manifolds have infinite co-dimensions, they do appear naturally in certain settings; for example, in (a......) the regularization of piecewise smooth systems by tanh, (b) a particular aircraft landing dynamics model, and finally (c) in a model of earthquake faulting. We demonstrate the approach using a simple model system and the examples (a) and (b)....

  18. Blowup for flat slow manifolds

    Science.gov (United States)

    Kristiansen, K. U.

    2017-05-01

    In this paper, we present a way of extending the blowup method, in the formulation of Krupa and Szmolyan, to flat slow manifolds that lose hyperbolicity beyond any algebraic order. Although these manifolds have infinite co-dimensions, they do appear naturally in certain settings; for example, in (a) the regularization of piecewise smooth systems by \\tanh , (b) a particular aircraft landing dynamics model, and finally (c) in a model of earthquake faulting. We demonstrate the approach using a simple model system and the examples (a) and (b).

  19. Nanoelectronics-biology frontier: From nanoscopic probes for action potential recording in live cells to three-dimensional cyborg tissues.

    Science.gov (United States)

    Duan, Xiaojie; Fu, Tian-Ming; Liu, Jia; Lieber, Charles M

    2013-08-01

    for the first time using macroporous nanoelectronic scaffolds that are analogous to synthetic tissue scaffold and the extracellular matrix in tissue. Free-standing 3D nanoelectronic scaffolds were cultured with neurons, cardiomyocytes and smooth muscle cells to yield electronically-innervated synthetic or 'cyborg' tissues. Measurements demonstrate that innervated tissues exhibit similar cell viability as with conventional tissue scaffolds, and importantly, demonstrate that the real-time response to drugs and pH changes can be mapped in 3D through the tissues. These results open up a new field of research, wherein nanoelectronics are merged with biological systems in 3D thereby providing broad opportunities, ranging from a nanoelectronic/tissue platform for real-time pharmacological screening in 3D to implantable 'cyborg' tissues enabling closed-loop monitoring and treatment of diseases. Furthermore, the capability of high density scale-up of the above extra- and intracellular nanoscopic probes for action potential recording provide important tools for large-scale high spatio-temporal resolution electrical neural activity mapping in both 2D and 3D, which promises to have a profound impact on many research areas, including the mapping of activity within the brain.

  20. Polyurethane adhesives in flat roofs

    Directory of Open Access Journals (Sweden)

    Bogárová Markéta

    2017-01-01

    Full Text Available It is necessary to stabilize individual layers of flat roofs, mainly because of wind suction. Apart from anchoring and surcharge, these layers can be secured by bonding. At present gluing is an indispensable and widely used stabilization method. On our market we can found many types of adhesives, most widely used are based on polyurethane. This paper focuses on problematic about stabilization thermal insulation from expanded polystyrene to vapor barrier from bitumen. One of the main issues is to calculate the exact amount of adhesive, which is required to guarantee the resistance against wind suction. In this problematic we can not find help neither in technical data sheets provided by the manufactures. Some of these data sheets contain at least information about amount of adhesive depending on location in roof plane and building height, but they do not specify the strength of such connection. It was therefore resorted to select several representatives polyurethane adhesives and their subsequent testing on specimens simulating the flat roof segment. The paper described the test methodology and results for two types of polyurethane adhesives.

  1. Closing Rocky Flats by 2006

    International Nuclear Information System (INIS)

    Tuor, N. R.; Schubert, A. L.

    2002-01-01

    Safely accelerating the closure of Rocky Flats to 2006 is a goal shared by many: the State of Colorado, the communities surrounding the site, the U.S. Congress, the Department of Energy, Kaiser-Hill and its team of subcontractors, the site's employees, and taxpayers across the country. On June 30, 2000, Kaiser-Hill (KH) submitted to the Department of Energy (DOE), KH's plan to achieve closure of Rocky Flats by December 15, 2006, for a remaining cost of $3.96 billion (February 1, 2000, to December 15, 2006). The Closure Project Baseline (CPB) is the detailed project plan for accomplishing this ambitious closure goal. This paper will provide a status report on the progress being made toward the closure goal. This paper will: provide a summary of the closure contract completion criteria; give the current cost and schedule variance of the project and the status of key activities; detail important accomplishments of the past year; and discuss the challenges ahead

  2. Flat Coalgebraic Fixed Point Logics

    Science.gov (United States)

    Schröder, Lutz; Venema, Yde

    Fixed point logics are widely used in computer science, in particular in artificial intelligence and concurrency. The most expressive logics of this type are the μ-calculus and its relatives. However, popular fixed point logics tend to trade expressivity for simplicity and readability, and in fact often live within the single variable fragment of the μ-calculus. The family of such flat fixed point logics includes, e.g., CTL, the *-nesting-free fragment of PDL, and the logic of common knowledge. Here, we extend this notion to the generic semantic framework of coalgebraic logic, thus covering a wide range of logics beyond the standard μ-calculus including, e.g., flat fragments of the graded μ-calculus and the alternating-time μ-calculus (such as ATL), as well as probabilistic and monotone fixed point logics. Our main results are completeness of the Kozen-Park axiomatization and a timed-out tableaux method that matches ExpTime upper bounds inherited from the coalgebraic μ-calculus but avoids using automata.

  3. National construction, Denmark. Flat roofs

    Energy Technology Data Exchange (ETDEWEB)

    Rode, C

    1995-04-01

    The Paris meeting of IEA Annex 24 (held in the spring of 1991) declared a set of typical building constructions, the Heat, Air and Moisture characteristics of which should be dealt with as part of the Annex work. Each type of construction was assigned to one or more countries as their National Construction, and it has been the responsibility of each country to prepare a report on what may be regarded as common knowledge in the country on the hygrothermal behaviour of their construction. This knowledge is in part due to experimental work carried out by research bodies in the countries, and due to experience form practice. This report has two main sections: Section 2 gives a general overview of the design of the most common variants of flat roofs and common knowledge reported for such roofs. Section 3 gives an account of research projects carried out in Denmark on flat roofs to analyze their hygrothermal performance. Whenever possible, an emphasis will be put on the hygrothermal consequences of thermally insulating such constructions. (EG) 19 refs.

  4. Neuroanatomy from Mesoscopic to Nanoscopic Scales: An Improved Method for the Observation of Semithin Sections by High-Resolution Scanning Electron Microscopy.

    Science.gov (United States)

    Rodríguez, José-Rodrigo; Turégano-López, Marta; DeFelipe, Javier; Merchán-Pérez, Angel

    2018-01-01

    Semithin sections are commonly used to examine large areas of tissue with an optical microscope, in order to locate and trim the regions that will later be studied with the electron microscope. Ideally, the observation of semithin sections would be from mesoscopic to nanoscopic scales directly, instead of using light microscopy and then electron microscopy (EM). Here we propose a method that makes it possible to obtain high-resolution scanning EM images of large areas of the brain in the millimeter to nanometer range. Since our method is compatible with light microscopy, it is also feasible to generate hybrid light and electron microscopic maps. Additionally, the same tissue blocks that have been used to obtain semithin sections can later be used, if necessary, for transmission EM, or for focused ion beam milling and scanning electron microscopy (FIB-SEM).

  5. "Flat-Fish" Vacuum Chamber

    CERN Multimedia

    CERN PhotoLab

    1978-01-01

    The picture shows a "Flat-Fish" vacuum chamber being prepared in the ISR workshop for testing prior to installation in the Split Field Magnet (SFM) at intersection I4. The two shells of each part were hydroformed from 0.15 mm thick inconel 718 sheet (with end parts in inconel 600 for easier manual welding to the arms) and welded toghether with two strips which were attached by means of thin stainless steel sheets to the Split Field Magnet poles in order to take the vertical component of the atmospheric pressure force. This was the thinnest vacuum chamber ever made for the ISR. Inconel material was chosen for its high elastic modulus and strenght at chamber bake-out temperature. In this picture the thin sheets transferring the vertical component of the atmosferic pressure force are attached to a support frame for testing. See also 7712182, 7712179.

  6. Research on Control Strategies of an Open-End Winding Permanent Magnet Synchronous Driving Motor (OW-PMSM-Equipped Dual Inverter with a Switchable Winding Mode for Electric Vehicles

    Directory of Open Access Journals (Sweden)

    Liang Chu

    2017-05-01

    Full Text Available An open-end winding permanent magnet synchronous motor (PMSM has a larger range of speed regulation than normal PMSM with the same DC voltage, and the control method is more flexible. It can also manage energy distribution between two power sources without a DC/DC converter. This paper aims at an electric vehicle equipped with OW-PMSM drive system with dual power sources and dual inverters; based on analyzing the external characteristics of each winding mode, we propose a winding mode switching strategy whose torque saturation judgmental algorithm, which is insensitive to motor’s parameters, could automatically realize upswitching of the winding mode. The proposed multi-level current hysteresis modulation algorithm could set the major power source and switch it at any time in independent mode, which accomplishes energy distribution between two power sources; its two control methods, low switching frequency method and high power difference method, could achieve different energy distribution effects. Simulation results confirm the validity and effectiveness of the winding mode switching strategy and current modulation method. They also show that an electric vehicle under the proposed control methods has better efficiency than one equipped with a traditional OW-PMSM drive system under traditional control.

  7. Laser Doppler thermometry in flat flames

    NARCIS (Netherlands)

    Maaren, van A.; Goey, de L.P.H.

    1994-01-01

    Laser Doppler Velocimetry measurements are performed in flat flames, stabilized on a newly developed flat-flame burner. It is shown that the velocity component perpendicular to the main flow direction, induced by expansion in the reaction zone and buoyancy in the burnt gas, is significant. A method

  8. Radiation monitor training program at Rocky Flats

    International Nuclear Information System (INIS)

    Medina, L.C.; Kittinger, W.D.; Vogel, R.M.

    The Rocky Flats Radiation Monitor Training Program is tailored to train new health physics personnel in the field of radiation monitoring. The purpose of the prescribed materials and media is to be consistent in training in all areas of Rocky Flats radiation monitoring job involvement

  9. Flat flexible polymer heat pipes

    International Nuclear Information System (INIS)

    Oshman, Christopher; Li, Qian; Liew, Li-Anne; Yang, Ronggui; Bright, Victor M; Lee, Y C

    2013-01-01

    Flat, flexible, lightweight, polymer heat pipes (FPHP) were fabricated. The overall geometry of the heat pipe was 130 mm × 70 mm × 1.31 mm. A commercially available low-cost film composed of laminated sheets of low-density polyethylene terephthalate, aluminum and polyethylene layers was used as the casing. A triple-layer sintered copper woven mesh served as a liquid wicking structure, and water was the working fluid. A coarse nylon woven mesh provided space for vapor transport and mechanical rigidity. Thermal power ranging from 5 to 30 W was supplied to the evaporator while the device was flexed at 0°, 45° and 90°. The thermal resistance of the FPHP ranged from 1.2 to 3.0 K W −1 depending on the operating conditions while the thermal resistance for a similar-sized solid copper reference was a constant at 4.6 K W −1 . With 25 W power input, the thermal resistance of the liquid–vapor core of the FPHP was 23% of a copper reference sample with identical laminated polymer material. This work shows a promising combination of technologies that has the potential to usher in a new generation of highly flexible, lightweight, low-cost, high-performance thermal management solutions. (paper)

  10. Long-range Rocky Flats utilization study

    International Nuclear Information System (INIS)

    1983-02-01

    The purpose of this Study was to provide information concerning the Rocky Flats Plant and its operations that will be useful to the Nation's decision-makers in determining the long-range future of the Plant. This Study was conducted under the premise that national defense policy must be supported and, accordingly, the capabilities at Rocky Flats must be maintained there or at some other location(s). The Study, therefore, makes no attempt to speculate on how possible future changes in national defense policy might affect decisions regarding the utilization of Rocky Flats. Factors pertinent to decisions regarding Rocky Flats, which are included in the Study, are: physical condition of the Plant and its vulnerabilities to natural phenomena; risks associated with plutonium to Plant workers and the public posed by postulated natural phenomena and operational accidents; identification of alternative actions regarding the future use of the Rocky Flats Plant with associated costs and time scales; local socioeconomic impacts if Rocky Flats operations were relocated; and potential for other uses if Rocky Flats facilities were vacated. The results of the tasks performed in support of this Study are summarized in the context of these five factors

  11. Chaotic inflation in models with flat directions

    International Nuclear Information System (INIS)

    Graziani, F.; Olive, K.

    1989-01-01

    We consider the chaotic inflationary scenario in models with flat directions. We find that unless the scalars along the flat directions have vacuum expectation values p or 10 14 M p 15 M p depending on the expectation values of the chaotic inflator, Ψ, one or two or more periods of inflation occur but with a resulting energy density perturbation δρ/ρ ≅ 10 -16 , far too small to be of any consequence for galaxy formation. Even with p only limited initial values of ≅ (3-200) M p result in inflation with reasonable density perturbations. Thus chaotic inflation in models with flat directions require rather special initial conditions. (orig.)

  12. Morphodynamic Modeling of Tidal Mud Flats

    National Research Council Canada - National Science Library

    Winterwerp, Johan C

    2008-01-01

    The objective of the current research proposal is to develop and test a numerical model to simulate and predict the seasonal morphodynamic evolution of intertidal mud flats in macrotidal environments...

  13. Near-field flat focusing mirrors

    Science.gov (United States)

    Cheng, Yu-Chieh; Staliunas, Kestutis

    2018-03-01

    This article reviews recent progress towards the design of near-field flat focusing mirrors, focusing/imaging light patterns in reflection. An important feature of such flat focusing mirrors is their transverse invariance, as they do not possess any optical axis. We start with a review of the physical background to the different focusing mechanisms of near- and far-field focusing. These near-field focusing devices like flat lenses and the reviewed near-field focusing mirrors can implement planar focusing devices without any optical axis. In contrast, various types of far-field planar focusing devices, such as high-contrast gratings and metasurfaces, unavoidably break the transverse invariance due to their radially symmetrical structures. The particular realizations of near-field flat focusing mirrors including Bragg-like dielectric mirrors and dielectric subwavelength gratings are the main subjects of the review. The first flat focusing mirror was demonstrated with a chirped mirror and was shown to manage an angular dispersion for beam focusing, similar to the management of chromatic dispersion for pulse compression. Furthermore, the reviewed optimized chirped mirror demonstrated a long near-field focal length, hardly achieved by a flat lens or a planar hyperlens. Two more different configurations of dielectric subwavelength gratings that focus a light beam at normal or oblique incidence are also reviewed. We also summarize and compare focusing performance, limitations, and future perspectives between the reviewed flat focusing mirrors and other planar focusing devices including a flat lens with a negative-index material, a planar hyperlens, a high-contrast grating, and a metasurface.

  14. Flat H Frangible Joint Evolution

    Science.gov (United States)

    Diegelman, Thomas E.; Hinkel, Todd J.; Benjamin, Andrew; Rochon, Brian V.; Brown, Christopher W.

    2016-01-01

    Space vehicle staging and separation events require pyrotechnic devices. They are single-use mechanisms that cannot be tested, nor can failure-tolerant performance be demonstrated in actual flight articles prior to flight use. This necessitates the implementation of a robust design and test approach coupled with a fully redundant, failure-tolerant explosive mechanism to ensure that the system functions even in the event of a single failure. Historically, NASA has followed the single failure-tolerant (SFT) design philosophy for all human-rated spacecraft, including the Space Shuttle Program. Following the end of this program, aerospace companies proposed building the next generation human-rated vehicles with off-the-shelf, non-redundant, zero-failure-tolerant (ZFT) separation systems. Currently, spacecraft and launch vehicle providers for both the Orion and Commercial Crew Programs (CCPs) plan to deviate from the heritage safety approach and NASA's SFT human rating requirements. Both programs' partners have base-lined ZFT frangible joints for vehicle staging and fairing separation. These joints are commercially available from pyrotechnic vendors. Non-human-rated missions have flown them numerous times. The joints are relatively easy to integrate structurally within the spacecraft. In addition, the separation event is debris free, and the resultant pyro shock is lower than that of other design solutions. It is, however, a serious deficiency to lack failure tolerance. When used for critical applications on human-rated vehicles, a single failure could potentially lead to loss of crew (LOC) or loss of mission (LOM)). The Engineering and Safety & Mission Assurance directorates within the NASA Johnson Space Center took action to address this safety issue by initiating a project to develop a fully redundant, SFT frangible joint design, known as the Flat H. Critical to the ability to retrofit on launch vehicles being developed, the SFT mechanisms must fit within the same

  15. Transport processes in intertidal sand flats

    Science.gov (United States)

    Wu, Christy

    2010-05-01

    Methane rich sulfate depleted seeps are observed along the low water line of the intertidal sand flat Janssand in the Wadden Sea. It is unclear where in the flat the methane is formed, and how it is transported to the edge of the sand flat where the sulfidic water seeps out. Methane and sulfate distributions in pore water were determined along transects from low water line toward the central area of the sand flat. The resulting profiles showed a zone of methane-rich and sulfate-depleted pore water below 2 m sediment depth. Methane production and sulfate reduction are monitored over time for surface sediments collected from the upper flat and seeping area. Both activities were at 22 C twice as high as at 15 C. The rates in sediments from the central area were higher than in sediments from the methane seeps. Methanogenesis occurred in the presence of sulfate, and was not significantly accelerated when sulfate was depleted. The observations show a rapid anaerobic degradation of organic matter in the Janssand. The methane rich pore water is obviously transported with a unidirectional flow from the central area of the intertidal sand flat toward the low water line. This pore water flow is driven by the pressure head caused by elevation of the pore water relative to the sea surface at low tide (Billerbeck et al. 2006a). The high methane concentration at the low water line accumulates due to a continuous outflow of pore water at the seepage site that prevents penetration of electron acceptors such as oxygen and sulfate to reoxidize the reduced products of anaerobic degradation (de Beer et al. 2006). It is, however, not clear why no methane accumulates or sulfate is depleted in the upper 2 m of the flats.

  16. Flat detectors and their clinical applications

    International Nuclear Information System (INIS)

    Spahn, Martin

    2005-01-01

    Diagnostic and interventional flat detector X-ray systems are penetrating the market in all application segments. First introduced in radiography and mammography, they have conquered cardiac and general angiography and are getting increasing attention in fluoroscopy. Two flat detector technologies prevail. The dominating method is based on an indirect X-ray conversion process, using cesium iodide scintillators. It offers considerable advantages in radiography, angiography and fluoroscopy. The other method employs a direct converter such as selenium which is particularly suitable for mammography. Both flat detector technologies are based on amorphous silicon active pixel matrices. Flat detectors facilitate the clinical workflow in radiographic rooms, foster improved image quality and provide the potential to reduce dose. This added value is based on their large dynamic range, their high sensitivity to X-rays and the instant availability of the image. Advanced image processing is instrumental in these improvements and expand the range of conventional diagnostic methods. In angiography and fluoroscopy the transition from image intensifiers to flat detectors is facilitated by ample advantages they offer, such as distortion-free images, excellent coarse contrast, large dynamic range and high X-ray sensitivity. These characteristics and their compatibility with strong magnetic fields are the basis for improved diagnostic methods and innovative interventional applications. (orig.)

  17. Instability of flat space at finite temperature

    International Nuclear Information System (INIS)

    Gross, D.J.; Perry, M.J.; Yaffe, L.G.

    1982-01-01

    The instabilities of quantum gravity are investigated using the path-integral formulation of Einstein's theory. A brief review is given of the classical gravitational instabilities, as well as the stability of flat space. The Euclidean path-integral representation of the partition function is employed to discuss the instability of flat space at finite temperature. Semiclassical, or saddle-point, approximations are utilized. We show how the Jeans instability arises as a tachyon in the graviton propagator when small perturbations about hot flat space are considered. The effect due to the Schwarzschild instanton is studied. The small fluctuations about this instanton are analyzed and a negative mode is discovered. This produces, in the semiclassical approximation, an imaginary part of the free energy. This is interpreted as being due to the metastability of hot flat space to nucleate black holes. These then evolve by evaporation or by accretion of thermal gravitons, leading to the instability of hot flat space. The nucleation rate of black holes is calculated as a function of temperature

  18. Magnetized and Flat Beam Experiment at FAST

    Energy Technology Data Exchange (ETDEWEB)

    Halavanau, A. [Fermilab; Hyun, J. [Sokendai, Tsukuba; Mihalcea, D. [NIU, DeKalb; Piot, P. [NICADD, DeKalb; Sen, T. [Fermilab; Thangaraj, C. [Fermilab

    2017-05-22

    A photocathode, immersed in solenoidal magnetic field, can produce canonical-angular-momentum (CAM) dominated or “magnetized” electron beams. Such beams have an application in electron cooling of hadron beams and can also be uncoupled to yield asymmetric-emittance (“flat”) beams. In the present paper we explore the possibilities of the flat beam generation at Fermilab’s Accelerator Science and Technology (FAST) facility. We present optimization of the beam flatness and four-dimensional transverse emittance and investigate the mapping and its limitations of the produced eigen-emittances to conventional emittances using a skew-quadrupole channel. Possible application of flat beams at the FAST facility are also discussed.

  19. Issues evaluation process at Rocky Flats Plant

    International Nuclear Information System (INIS)

    Smith, L.C.

    1992-01-01

    This report describes the issues evaluation process for Rocky Flats Plant as established in July 1990. The issues evaluation process was initiated February 27, 1990 with a Charter and Process Overview for short-term implementation. The purpose of the process was to determine the projects required for completion before the Phased Resumption of Plutonium Operations. To determine which projects were required, the issues evaluation process and emphasized risk mitigation, based on a ranking system. The purpose of this report is to document the early design of the issues evaluation process to record the methodologies used that continue as the basis for the ongoing Issues Management Program at Rocky Flats Plant

  20. Holography and Entanglement in Flat Spacetime

    International Nuclear Information System (INIS)

    Li Wei; Takayanagi, Tadashi

    2011-01-01

    We propose a holographic correspondence of the flat spacetime based on the behavior of the entanglement entropy and the correlation functions. The holographic dual theory turns out to be highly nonlocal. We argue that after most part of the space is traced out, the reduced density matrix gives the maximal entropy and the correlation functions become trivial. We present a toy model for this holographic dual using a nonlocal scalar field theory that reproduces the same property of the entanglement entropy. Our conjecture is consistent with the entropy of Schwarzschild black holes in asymptotically flat spacetimes.

  1. Remediation of the Maxey Flats Site

    International Nuclear Information System (INIS)

    1990-01-01

    This report describes issues associated with remedial action of Maxey Flats, a low-level radioactive waste disposal site from 1963-1977, located in Fleming County, Kentucky. Present remedial action alternatives being considered are discussed along with emergency plans, ground water monitoring plans, and budgets

  2. Status of flat electron beam production

    International Nuclear Information System (INIS)

    Edwards, Donald A.

    2001-01-01

    Last year at LINAC2000 [1] the authors reported their initial verification of the round beam (comparable transverse emittances) to flat beam (high transverse emittance ratio) transformation described by Brinkmann, Derbenev, and Floettmann [2]. Further analysis of the data has confirmed that a transverse emittance ratio of approximately 50 was observed. Graphics representing observational detail are included here, and future plans outlined

  3. Flat deformation theorem and symmetries in spacetime

    International Nuclear Information System (INIS)

    Llosa, Josep; Carot, Jaume

    2009-01-01

    The flat deformation theorem states that given a semi-Riemannian analytic metric g on a manifold, locally there always exists a two-form F, a scalar function c, and an arbitrarily prescribed scalar constraint depending on the point x of the manifold and on F and c, say Ψ(c, F, x) = 0, such that the deformed metric η = cg - εF 2 is semi-Riemannian and flat. In this paper we first show that the above result implies that every (Lorentzian analytic) metric g may be written in the extended Kerr-Schild form, namely η ab := ag ab - 2bk (a l b) where η is flat and k a , l a are two null covectors such that k a l a = -1; next we show how the symmetries of g are connected to those of η, more precisely; we show that if the original metric g admits a conformal Killing vector (including Killing vectors and homotheties), then the deformation may be carried out in a way such that the flat deformed metric η 'inherits' that symmetry.

  4. Flat roofs, a grey area; Grauzone Flachdach

    Energy Technology Data Exchange (ETDEWEB)

    Riedel, Anja

    2012-11-01

    The boom of low-ballast assembly systems for flat roofs is going on. Solar assembly racks are set up directly on the sealing foil without fastening bolts. But what happens in case of water ingress? And what should be done to prevent damage to the roof cover? (orig.)

  5. Computational Design of Flat-Band Material

    Science.gov (United States)

    Hase, I.; Yanagisawa, T.; Kawashima, K.

    2018-02-01

    Quantum mechanics states that hopping integral between local orbitals makes the energy band dispersive. However, in some special cases, there are bands with no dispersion due to quantum interference. These bands are called as flat band. Many models having flat band have been proposed, and many interesting physical properties are predicted. However, no real compound having flat band has been found yet despite the 25 years of vigorous researches. We have found that some pyrochlore oxides have quasi-flat band just below the Fermi level by first principles calculation. Moreover, their valence bands are well described by a tight-binding model of pyrochlore lattice with isotropic nearest neighbor hopping integral. This model belongs to a class of Mielke model, whose ground state is known to be ferromagnetic with appropriate carrier doping and on-site repulsive Coulomb interaction. We have also performed a spin-polarized band calculation for the hole-doped system from first principles and found that the ground state is ferromagnetic for some doping region. Interestingly, these compounds do not include magnetic element, such as transition metal and rare-earth elements.

  6. Do intertidal flats ever reach equilibrium?

    NARCIS (Netherlands)

    Maan, D.C.; van Prooijen, B.C.; Wang, Z.B.; de Vriend, H.J.

    2015-01-01

    Various studies have identified a strong relation between the hydrodynamic forces and the equilibrium profile for intertidal flats. A thorough understanding of the interplay between the hydrodynamic forces and the morphology, however, concerns more than the equilibrium state alone. We study the

  7. Nonflat equilibrium liquid shapes on flat surfaces.

    Science.gov (United States)

    Starov, Victor M

    2004-01-15

    The hydrostatic pressure in thin liquid layers differs from the pressure in the ambient air. This difference is caused by the actions of surface forces and capillary pressure. The manifestation of the surface force action is the disjoining pressure, which has a very special S-shaped form in the case of partial wetting (aqueous thin films and thin films of aqueous electrolyte and surfactant solutions, both free films and films on solid substrates). In thin flat liquid films the disjoining pressure acts alone and determines their thickness. However, if the film surface is curved then both the disjoining and the capillary pressures act simultaneously. In the case of partial wetting their simultaneous action results in the existence of nonflat equilibrium liquid shapes. It is shown that in the case of S-shaped disjoining pressure isotherm microdrops, microdepressions, and equilibrium periodic films exist on flat solid substrates. Criteria are found for both the existence and the stability of these nonflat equilibrium liquid shapes. It is shown that a transition from thick films to thinner films can go via intermediate nonflat states, microdepressions and periodic films, which both can be more stable than flat films within some range of hydrostatic pressure. Experimental investigations of shapes of the predicted nonflat layers can open new possibilities of determination of disjoining pressure in the range of thickness in which flat films are unstable.

  8. 8. Asymptotically Flat and Regular Cauchy Data

    Science.gov (United States)

    Dain, Sergio

    I describe the construction of a large class of asymptotically flat initial data with non-vanishing mass and angular momentum for which the metric and the extrinsic curvature have asymptotic expansions at space-like infinity in terms of powers of a radial coordinate. I emphasize the motivations and the main ideas behind the proofs.

  9. Design scenarios for flat panel photobioreactors

    NARCIS (Netherlands)

    Slegers, P.M.; Wijffels, R.H.; Straten, van G.; Boxtel, van A.J.B.

    2011-01-01

    Evaluation of the potential of algae production for biofuel and other products at various locations throughout the world requires assessment of algae productivity under varying light conditions and different reactor layouts. A model was developed to predict algae biomass production in flat panel

  10. Completeness for flat modal fixpoint logics

    NARCIS (Netherlands)

    Santocanale, L.; Venema, Y.

    2010-01-01

    This paper exhibits a general and uniform method to prove axiomatic completeness for certain modal fixpoint logics. Given a set Γ of modal formulas of the form γ(x,p1,…,pn), where x occurs only positively in γ, we obtain the flat modal fixpoint language L♯(Γ) by adding to the language of polymodal

  11. Hangingwall accomodation styles in flat ramp trust

    NARCIS (Netherlands)

    Mulugeta, G.; Sokoutis, D.

    2003-01-01

    In this paper we study the dynamic and rheologic control of hanging wall accommodation in ramp-flat thrust models. In particular we vary the dimensionless ratio of shear strength to gravity stress to model hanging wall accommodation styles in different materials. In all models we require that the

  12. Designing Flat-Plate Photovoltaic Arrays

    Science.gov (United States)

    Ross, R. G., Jr.

    1984-01-01

    Report presents overview of state of art in design techniques for flat-plate solar photovoltaic modules and arrays. Paper discusses design requirements, design analyses, and test methods identified and developed for this technology over past several years in effort to reduce cost and improve utility and reliability for broad spectrum of terrestrial applications.

  13. Exact Riemann solutions of the Ripa model for flat and non-flat bottom topographies

    Science.gov (United States)

    Rehman, Asad; Ali, Ishtiaq; Qamar, Shamsul

    2018-03-01

    This article is concerned with the derivation of exact Riemann solutions for Ripa model considering flat and non-flat bottom topographies. The Ripa model is a system of shallow water equations accounting for horizontal temperature gradients. In the case of non-flat bottom topography, the mass, momentum and energy conservation principles are utilized to relate the left and right states across the step-type bottom topography. The resulting system of algebraic equations is solved iteratively. Different numerical case studies of physical interest are considered. The solutions obtained from developed exact Riemann solvers are compared with the approximate solutions of central upwind scheme.

  14. General classification of a normally flat Ric- semi symmetric submanifolds

    International Nuclear Information System (INIS)

    Mirzoyan, V.A.

    2012-01-01

    It has been proved that a normally flat submanifold M in Euclidean space En satisfies the condition R(X,Y)Ricci =0 if and only if it is the open part of one of the following submanifolds: (1) normally flat two-dimensional submanifold, (2) normally flat Einstein submanifold (in particular Ricci-flat or locally Euclidean), (3) normally flat semi- Einstein submanifold, (4) normally flat interlacing product of semi-Einstein submanifolds and locally Euclidean submanifold (may be of zero dimension), (5) direct product of the above enumerated classes of submanifolds

  15. A Flat World with Deep Fractures

    Directory of Open Access Journals (Sweden)

    Emil Constantinescu

    2016-10-01

    Full Text Available The Internet manages to connect different parts of the world, defies geographical distances and gives the impression that our planet is flat, but the Internet is there only for the ones who have the possibility and the ability to use it. Our contemporary flat world has deep transversal fractures which, like in many geological structures, make a direct connection between layers with different characteristics. The elites are moving across information avenues with targets set in the future; at the same time, in many parts of our planet, there are people organizing their lives in pre-modern agrarian cycles. Diversity in ways of living and in social organization is a sign of human freedom, not a sign of error, so, having different alternatives to achieving prosperity and happiness should be good news. Holding dear to a society’s lifestyle should not push for the destruction of societies with different sets of values.

  16. Towards a flat 45%-efficient concentrator module

    Energy Technology Data Exchange (ETDEWEB)

    Mohedano, Rubén, E-mail: rmohedano@lpi-europe.com; Hernandez, Maikel; Vilaplana, Juan; Chaves, Julio; Sorgato, S.; Falicoff, Waqidi [LPI, Altadena, CA, USA and Madrid (Spain); Miñano, Juan C.; Benitez, Pablo [LPI, Altadena, CA, USA and Madrid (Spain); Universidad Politécnica de Madrid (UPM), Campus de Montegancedo, Madrid (Spain)

    2015-09-28

    The so-called CCS{sup 4}FK is an ultra-flat photovoltaic system of high concentration and high efficiency, with potential to convert, ideally, the equivalent of a 45% of direct solar radiation into electricity by optimizing the usage of sun spectrum and by collecting part of the diffuse radiation, as a flat plate does. LPI has recently finished a design based on this concept and is now developing a prototype based on this technology, thanks to the support of FUNDACION REPSOL-Fondo de Emprendedores, which promotes entrepreneur projects in different areas linked to energy. This works shows some details of the actual design and preliminary potential performance expected, according to accurate spectral simulations.

  17. Release fractions for Rocky Flats specific accidents

    International Nuclear Information System (INIS)

    Weiss, R.C.

    1992-01-01

    As Rocky Flats and other DOE facilities begin the transition process towards decommissioning, the nature of the scenarios to be studied in safety analysis will change. Whereas the previous emphasis in safety accidents related to production, now the emphasis is shifting to accidents related tc decommissioning and waste management. Accident scenarios of concern at Rocky Flats now include situations of a different nature and different scale than are represented by most of the existing experimental accident data. This presentation will discuss approaches at sign to use for applying the existing body of release fraction data to this new emphasis. Mention will also be made of ongoing efforts to produce new data and improve the understanding of physical mechanisms involved

  18. Standard specification for silvered flat glass mirror

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2008-01-01

    1.1 This specification covers the requirements for silvered flat glass mirrors of rectangular shape supplied as cut sizes, stock sheets or as lehr ends and to which no further processing (such as edgework or other fabrication) has been done. 1.2 This specification covers the quality requirements of silvered annealed monolithic clear and tinted flat glass mirrors up to 6 mm (¼ in.) thick. The mirrors are intended to be used indoors for mirror glazing, for components of decorative accessories or for similar uses. 1.3 This specification does not address safety glazing materials nor requirements for mirror applications. Consult model building codes and other applicable standards for safety glazing applications. 1.4 Mirrors covered in this specification are not intended for use in environments where high humidity or airborne corrosion promoters, or both, are consistently present (such as swimming pool areas, ocean-going vessels, chemical laboratories and other corrosive environments). 1.5 The dimensional val...

  19. History of Rocky Flats waste streams

    International Nuclear Information System (INIS)

    Luckett, L.L.; Dickman, A.A.; Wells, C.R.; Vickery, D.J.

    1982-01-01

    An analysis of the waste streams at Rocky Flats was done to provide information for the Waste Certification program. This program has involved studying the types and amounts of retrievable transuranic (TRU) waste from Rocky Flats that is stored at the Idaho National Engineering Laboratory (INEL). The information can be used to estimate the types and amounts of waste that will need to be permanently stored in the Waste Isolation Pilot Plant (WIPP). The study covered mostly the eight-year period from June 1971 to June 1979. The types, amounts, and plutonium content of TRU waste and the areas or operations responsible for generating the waste are summarized in this waste stream history report. From the period studied, a total of 24,546,153 lbs of waste containing 211,148 g of plutonium currently occupies 709,497 cu ft of storage space at INEL

  20. Infiltration barrier demonstration at Maxey Flats, Kentucky

    International Nuclear Information System (INIS)

    Mills, D.; Razor, J.

    1983-01-01

    At the 1982 DOE LLWMP meeting, the Kentucky Natural Resources and Environmental Protection Cabinet presented a history of the Maxey Flats Waste Disposal Facility, its status, and current Commonwealth activities leading toward stabilization and decommissioning. Information was presented at that time on the purpose of the DOE Trench Moisture Barrier Demonstration Grant and the early phases of construction and implementation. In this paper, final construction and implementation of the trench moisture barrier demonstration are discussed. Data including trench water level measurements, lateral liquid flow in experimental sections, and soil moisture measurements are presented and discussed. The Paper is completed with a brief discussion of remediation activities currently being implemented at Maxey Flats. 9 references, 7 figures, 1 table

  1. Rocky Flats cleanup receives new deadline

    International Nuclear Information System (INIS)

    Anon.

    1993-01-01

    The Rocky Flats nuclear weapon plant near Denver narrowly missed a court-ordered shutdown of virtually all cleanup activities when it failed to meet an Aug. 22 deadline for a state permit to store mixed radioactive and hazardous wastes on site. US District Court Judge Lewis Babcock granted a 90-day stay of contempt charges against the US Dept. of Energy, but left open the possibility of civil penalties under the Resource Conservation and Recovery Act. DOE's problems stem from a lawsuit the Sierra Club won two years ago in which Babcock gave Rocky Flats until Aug. 22 to obtain a RCRA permit or interim status from Colorado to store 600 cu yd of mixed wastes. If DOE failed to do so, the court said it could not generate further hazardous wastes at the site

  2. Kinematic tests of exotic flat cosmological models

    International Nuclear Information System (INIS)

    Charlton, J.C.; Turner, M.S.; NASA/Fermilab Astrophysics Center, Batavia, IL)

    1987-01-01

    Theoretical prejudice and inflationary models of the very early universe strongly favor the flat, Einstein-de Sitter model of the universe. At present the observational data conflict with this prejudice. This conflict can be resolved by considering flat models of the universe which posses a smooth component of energy density. The kinematics of such models, where the smooth component is relativistic particles, a cosmological term, a network of light strings, or fast-moving, light strings is studied in detail. The observational tests which can be used to discriminate between these models are also discussed. These tests include the magnitude-redshift, lookback time-redshift, angular size-redshift, and comoving volume-redshift diagrams and the growth of density fluctuations. 58 references

  3. Modelling Flat Spring performance using FEA

    International Nuclear Information System (INIS)

    Fatola, B O; Keogh, P; Hicks, B

    2009-01-01

    This paper reports how the stiffness of a Flat Spring can be predicted using nonlinear Finite Element Analysis (FEA). The analysis of a Flat Spring is a nonlinear problem involving contact mechanics, geometric nonlinearity and material property nonlinearity. Research has been focused on improving the accuracy of the model by identifying and exploring the significant assumptions contributing to errors. This paper presents results from some of the models developed using FEA software. The validation process is shown to identify where improvements can be made to the model assumptions to increase the accuracy of prediction. The goal is to achieve an accuracy level of ±10 % as the intention is to replace practical testing with FEA modelling, thereby reducing the product development time and cost. Results from the FEA models are compared with experimental results to validate the accuracy.

  4. THERMAL PERFORMANCE OF FLAT PLATE SOLAR COLLECTOR

    Directory of Open Access Journals (Sweden)

    TABET I.

    2017-06-01

    Full Text Available In this paper, a theoretical and experimental studyof flat platesolar water collector with reflectors.A mathematical model based on energy balance equations saw the thermal behavior of the collector is investigated. The experimental test was made at the unit research applies in renewable energy (URAER located in southern Algeria.An increase of 23% for solar radiation incident on the collector surface with the addition of the planers reflectors in the day of May, this increase causes an improvement of the performance of the collector,the fluid temperature increases with an average of 5%. Thetests conducted on the flat plate solar water collector in open circuit enabled the determination of thermal performance of the collector by estimating the daily output The thermal efficiency of the collector ranges from 1% -63% during the day, a mean value of 36%obtained.

  5. Kinematic tests of exotic flat cosmological models

    International Nuclear Information System (INIS)

    Charlton, J.C.; Turner, M.S.

    1986-05-01

    Theoretical prejudice and inflationary models of the very early Universe strongly favor the flat, Einstein-deSitter model of the Universe. At present the observational data conflict with this prejudice. This conflict can be resolved by considering flat models of the Universe which possess a smooth component by energy density. We study in detail the kinematics of such models, where the smooth component is relativistic particles, a cosmological term, a network of light strings, or fast-moving, light strings. We also discuss the observational tests which can be used to discriminate between these models. These tests include the magnitude-redshift, lookback time-redshift, angular size-redshift, and comoving volume-redshift diagrams and the growth of density fluctuations

  6. Kinematic tests of exotic flat cosmological models

    Energy Technology Data Exchange (ETDEWEB)

    Charlton, J.C.; Turner, M.S.

    1986-05-01

    Theoretical prejudice and inflationary models of the very early Universe strongly favor the flat, Einstein-deSitter model of the Universe. At present the observational data conflict with this prejudice. This conflict can be resolved by considering flat models of the Universe which possess a smooth component by energy density. We study in detail the kinematics of such models, where the smooth component is relativistic particles, a cosmological term, a network of light strings, or fast-moving, light strings. We also discuss the observational tests which can be used to discriminate between these models. These tests include the magnitude-redshift, lookback time-redshift, angular size-redshift, and comoving volume-redshift diagrams and the growth of density fluctuations.

  7. Towards a flat 45%-efficient concentrator module

    Science.gov (United States)

    Mohedano, Rubén; Hernandez, Maikel; Vilaplana, Juan; Chaves, Julio; Miñano, Juan C.; Benitez, Pablo; Sorgato, S.; Falicoff, Waqidi

    2015-09-01

    The so-called CCS4FK is an ultra-flat photovoltaic system of high concentration and high efficiency, with potential to convert, ideally, the equivalent of a 45% of direct solar radiation into electricity by optimizing the usage of sun spectrum and by collecting part of the diffuse radiation, as a flat plate does. LPI has recently finished a design based on this concept and is now developing a prototype based on this technology, thanks to the support of FUNDACION REPSOL-Fondo de Emprendedores, which promotes entrepreneur projects in different areas linked to energy. This works shows some details of the actual design and preliminary potential performance expected, according to accurate spectral simulations.

  8. Towards a flat 45%-efficient concentrator module

    International Nuclear Information System (INIS)

    Mohedano, Rubén; Hernandez, Maikel; Vilaplana, Juan; Chaves, Julio; Sorgato, S.; Falicoff, Waqidi; Miñano, Juan C.; Benitez, Pablo

    2015-01-01

    The so-called CCS 4 FK is an ultra-flat photovoltaic system of high concentration and high efficiency, with potential to convert, ideally, the equivalent of a 45% of direct solar radiation into electricity by optimizing the usage of sun spectrum and by collecting part of the diffuse radiation, as a flat plate does. LPI has recently finished a design based on this concept and is now developing a prototype based on this technology, thanks to the support of FUNDACION REPSOL-Fondo de Emprendedores, which promotes entrepreneur projects in different areas linked to energy. This works shows some details of the actual design and preliminary potential performance expected, according to accurate spectral simulations

  9. Basic TRUEX process for Rocky Flats Plant

    International Nuclear Information System (INIS)

    Leonard, R.A.; Chamberlain, D.B.; Dow, J.A.; Farley, S.E.; Nunez, L.; Regalbuto, M.C.; Vandegrift, G.F.

    1994-08-01

    The Generic TRUEX Model was used to develop a TRUEX process flowsheet for recovering the transuranics (Pu, Am) from a nitrate waste stream at Rocky Flats Plant. The process was designed so that it is relatively insensitive to changes in process feed concentrations and flow rates. Related issues are considered, including solvent losses, feed analysis requirements, safety, and interaction with an evaporator system for nitric acid recycle

  10. Microwave solidification development for Rocky Flats waste

    Energy Technology Data Exchange (ETDEWEB)

    Dixon, D.; Erle, R.; Eschen, V. [and others

    1994-04-01

    The Microwave Engineering Team at the Rocky Flats Plant has developed a production-scale system for the treatment of hazardous, radioactive, and mixed wastes using microwave energy. The system produces a vitreous final form which meets the acceptance criteria for shipment and disposal. The technology also has potential for application on various other waste streams from the public and private sectors. Technology transfer opportunities are being identified and pursued for commercialization of the microwave solidification technology.

  11. Microwave solidification development for Rocky Flats waste

    International Nuclear Information System (INIS)

    Dixon, D.; Erle, R.; Eschen, V.

    1994-04-01

    The Microwave Engineering Team at the Rocky Flats Plant has developed a production-scale system for the treatment of hazardous, radioactive, and mixed wastes using microwave energy. The system produces a vitreous final form which meets the acceptance criteria for shipment and disposal. The technology also has potential for application on various other waste streams from the public and private sectors. Technology transfer opportunities are being identified and pursued for commercialization of the microwave solidification technology

  12. Optimised intake stroke analysis for flat and dome head pistons ...

    African Journals Online (AJOL)

    Optimised intake stroke analysis for flat and dome head pistons. ... in understanding the performance characteristics optioned between flat head and dome head pistons in engine design. ... EMAIL FREE FULL TEXT EMAIL FREE FULL TEXT

  13. How flat is our Universe really?

    International Nuclear Information System (INIS)

    Okouma, P.M.; Fantaye, Y.; Bassett, B.A.

    2013-01-01

    Distance measurement provides no constraints on curvature independent of assumptions about the dark energy, raising the question, how flat is our Universe if we make no such assumptions? Allowing for general evolution of the dark energy equation of state with 20 free parameters that are allowed to cross the phantom divide, w(z)=−1, we show that while it is indeed possible to match the first peak in the Cosmic Microwave Background with non-flat models and arbitrary Hubble constant, H 0 , the full WMAP7 and supernova data alone imply −0.12 k 0 prior, this tightens significantly to Ω k =0.002±0.009. These constitute the most conservative and model-independent constraints on curvature available today, and illustrate that the curvature-dynamics degeneracy is broken by current data, with a key role played by the Integrated Sachs Wolfe effect rather than the distance to the surface of last scattering. If one imposes a quintessence prior on the dark energy (−1⩽w(z)⩽1) then just the WMAP7 and supernova data alone force the Universe to near flatness: Ω k =0.013±0.012. Finally, allowing for curvature, we find that all datasets are consistent with a Harrison–Zel'dovich spectral index, n s =1, at 2σ, illustrating the interplay between early and late Universe constraints

  14. Stationary solutions and asymptotic flatness I

    International Nuclear Information System (INIS)

    Reiris, Martin

    2014-01-01

    In general relativity, a stationary isolated system is defined as an asymptotically flat (AF) stationary spacetime with compact material sources. Other definitions that are less restrictive on the type of asymptotic could in principle be possible. Between this article and its sequel, we show that under basic assumptions, asymptotic flatness indeed follows as a consequence of Einstein's theory. In particular, it is proved that any vacuum stationary spacetime-end whose (quotient) manifold is diffeomorphic to R 3 minus a ball and whose Killing field has its norm bounded away from zero, is necessarily AF with Schwarzschildian fall off. The ‘excised’ ball would contain (if any) the actual material body, but this information is unnecessary to reach the conclusion. In this first article, we work with weakly asymptotically flat (WAF) stationary ends, a notion that generalizes as much as possible that of the AF end, and prove that WAF ends are AF with Schwarzschildian fall off. Physical and mathematical implications are also discussed. (paper)

  15. Graphene nanoribbons production from flat carbon nanotubes

    Energy Technology Data Exchange (ETDEWEB)

    Melo, W. S.; Guerini, S.; Diniz, E. M., E-mail: eduardo.diniz@ufma.br [Departamento de Física, Universidade Federal do Maranhão, São Luís - MA 65080-805 (Brazil)

    2015-11-14

    Graphene nanoribbons are of great interest for pure and applied sciences due to their unique properties which depend on the nanoribbon edges, as, for example, energy gap and antiferromagnetic coupling. Nevertheless, the synthesis of nanoribbons with well-defined edges remains a challenge. To collaborate with this subject, here we propose a new route for the production of graphene nanoribbons from flat carbon nanotubes filled with a one-dimensional chain of Fe atoms by first principles calculations based on density functional theory. Our results show that Fe-filled flat carbon nanotubes are energetically more stable than non flattened geometries. Also we find that by hydrogenation or oxygenation of the most curved region of the Fe-filled flat armchair carbon nanotube, it occurred a spontaneous production of zigzag graphene nanoribbons which have metallic or semiconducting behavior depending on the edge and size of the graphene nanoribbon. Such findings can be used to create a new method of synthesis of regular-edge carbon nanoribbons.

  16. Graphene nanoribbons production from flat carbon nanotubes

    International Nuclear Information System (INIS)

    Melo, W. S.; Guerini, S.; Diniz, E. M.

    2015-01-01

    Graphene nanoribbons are of great interest for pure and applied sciences due to their unique properties which depend on the nanoribbon edges, as, for example, energy gap and antiferromagnetic coupling. Nevertheless, the synthesis of nanoribbons with well-defined edges remains a challenge. To collaborate with this subject, here we propose a new route for the production of graphene nanoribbons from flat carbon nanotubes filled with a one-dimensional chain of Fe atoms by first principles calculations based on density functional theory. Our results show that Fe-filled flat carbon nanotubes are energetically more stable than non flattened geometries. Also we find that by hydrogenation or oxygenation of the most curved region of the Fe-filled flat armchair carbon nanotube, it occurred a spontaneous production of zigzag graphene nanoribbons which have metallic or semiconducting behavior depending on the edge and size of the graphene nanoribbon. Such findings can be used to create a new method of synthesis of regular-edge carbon nanoribbons

  17. Design scenarios for flat panel photobioreactors

    International Nuclear Information System (INIS)

    Slegers, P.M.; Wijffels, R.H.; Straten, G. van; Boxtel, A.J.B. van

    2011-01-01

    Evaluation of the potential of algae production for biofuel and other products at various locations throughout the world requires assessment of algae productivity under varying light conditions and different reactor layouts. A model was developed to predict algae biomass production in flat panel photobioreactors using the interaction between light and algae growth for the algae species Phaeodactylum tricornutum and Thalassiosira pseudonana. The effect of location, variable sunlight and reactor layout on biomass production in single standing and parallel positioned flat panels was considered. Three latitudes were studied representing the Netherlands, France and Algeria. In single standing reactors the highest yearly biomass production is achieved in Algeria. During the year biomass production fluctuates the most in the Netherlands, while it is almost constant in Algeria. Several combinations of path lengths and biomass concentrations can result in the same optimal biomass production. The productivity in parallel place flat panels is strongly influenced by shading and diffuse light penetration between the panels. Panel orientation has a large effect on productivity and at higher latitudes the difference between north-south and east-west orientation may go up to 50%.

  18. How flat is our Universe really?

    Energy Technology Data Exchange (ETDEWEB)

    Okouma, P.M., E-mail: okouma@saao.ac.za [Department of Maths and Applied Maths, University of Cape Town, Rondebosch 7701, Cape Town (South Africa); South African Astronomical Observatory, Observatory, Cape Town (South Africa); African Institute for Mathematical Sciences, 6-8 Melrose Road, Muizenberg, Cape Town (South Africa); Centre for High Performance Computing, 15 Lower Hope St., Rosebank, Cape Town (South Africa); Fantaye, Y. [Astrophysics Sector, International School for Advanced Studies, SISSA, 34136 Trieste (Italy); Institute of Theoretical Astrophysics, University of Oslo, P.O. Box 1029 Blindern, N-0315, Oslo (Norway); Bassett, B.A. [Department of Maths and Applied Maths, University of Cape Town, Rondebosch 7701, Cape Town (South Africa); South African Astronomical Observatory, Observatory, Cape Town (South Africa); African Institute for Mathematical Sciences, 6-8 Melrose Road, Muizenberg, Cape Town (South Africa); Centre for High Performance Computing, 15 Lower Hope St., Rosebank, Cape Town (South Africa)

    2013-02-12

    Distance measurement provides no constraints on curvature independent of assumptions about the dark energy, raising the question, how flat is our Universe if we make no such assumptions? Allowing for general evolution of the dark energy equation of state with 20 free parameters that are allowed to cross the phantom divide, w(z)=−1, we show that while it is indeed possible to match the first peak in the Cosmic Microwave Background with non-flat models and arbitrary Hubble constant, H{sub 0}, the full WMAP7 and supernova data alone imply −0.12<Ω{sub k}<0.01 (2σ). If we add an H{sub 0} prior, this tightens significantly to Ω{sub k}=0.002±0.009. These constitute the most conservative and model-independent constraints on curvature available today, and illustrate that the curvature-dynamics degeneracy is broken by current data, with a key role played by the Integrated Sachs Wolfe effect rather than the distance to the surface of last scattering. If one imposes a quintessence prior on the dark energy (−1⩽w(z)⩽1) then just the WMAP7 and supernova data alone force the Universe to near flatness: Ω{sub k}=0.013±0.012. Finally, allowing for curvature, we find that all datasets are consistent with a Harrison–Zel'dovich spectral index, n{sub s}=1, at 2σ, illustrating the interplay between early and late Universe constraints.

  19. Rigidity of generalized Bach-flat vacuum static spaces

    Science.gov (United States)

    Yun, Gabjin; Hwang, Seungsu

    2017-11-01

    In this paper, we study the structure of generalized Bach-flat vacuum static spaces. Generalized Bach-flat metrics are considered as extensions of both Einstein and Bach-flat metrics. First, we prove that a compact Riemannian n-manifold with n ≥ 4 which is a generalized Bach-flat vacuum static space is Einstein. A generalized Bach-flat vacuum static space with the potential function f having compact level sets is either Ricci-flat or a warped product with zero scalar curvature when n ≥ 5, and when n = 4, it is Einstein if f has its minimum. Secondly, we consider critical metrics for another quadratic curvature functional involving the Ricci tensor, and prove similar results. Lastly, by applying the technique developed above, we prove Besse conjecture when the manifold is generalized Bach-flat.

  20. Flat H Redundant Frangible Joint Development

    Science.gov (United States)

    Brown, Chris

    2016-01-01

    Orion and Commercial Crew Program (CCP) Partners have chosen to use frangible joints for certain separation events. The joints currently available are zero failure tolerant and will be used in mission safety applications. The goal is to further develop a NASA designed redundant frangible joint that will lower flight risk and increase reliability. FY16 testing revealed a successful design in subscale straight test specimens that gained efficiency and supports Orion load requirements. Approach / Innovation A design constraint is that the redundant joint must fit within the current Orion architecture, without the need for additional vehicle modification. This limitation required a design that changed the orientation of the expanding tube assemblies (XTAs), by rotating them 90deg from the standard joint configuration. The change is not trivial and affects the fracture mechanism and structural load paths. To address these changes, the design incorporates cantilevered arms on the break plate. The shock transmission and expansion of the XTA applies force to these arms and creates a prying motion to push the plate walls outward to the point of structural failure at the notched section. The 2014 test design revealed that parts could slip during functioning wasting valuable energy needed to separate the structure with only a single XTA functioning. Dual XTA functioning fully separated the assembly showing a discrepancy can be backed up with redundancy. Work on other fully redundant systems outside NASA is limited to a few patents that have not been subjected to functionality testing Design changes to prevent unwanted slippage (with ICA funding in 2015) showed success with a single XTA. The main goal for FY 2016 was to send the new Flat H RFJ to WSTF where single XTA test failures occurred back in 2014. The plan was to gain efficiency in this design by separating the Flat H RFJ with thicker ligaments with dimensions baselined in 2014. Other modifications included geometry

  1. Flexible Polyhedral Surfaces with Two Flat Poses

    Directory of Open Access Journals (Sweden)

    Hellmuth Stachel

    2015-05-01

    Full Text Available We present three types of polyhedral surfaces, which are continuously flexible and have not only an initial pose, where all faces are coplanar, but pass during their self-motion through another pose with coplanar faces (“flat pose”. These surfaces are examples of so-called rigid origami, since we only admit exact flexions, i.e., each face remains rigid during the motion; only the dihedral angles vary. We analyze the geometry behind Miura-ori and address Kokotsakis’ example of a flexible tessellation with the particular case of a cyclic quadrangle. Finally, we recall Bricard’s octahedra of Type 3 and their relation to strophoids.

  2. Incorporation of flat glass in red ceramic

    International Nuclear Information System (INIS)

    Caldas, T.C.C.; Morais, A.S.C.; Pereira, P.S.; Monteiro, S.N.; Vieira, C.M.F.

    2011-01-01

    This work have as objective evaluate the effect of incorporation of up to 10% by weight of powdered flat glass , from civil industry, in red ceramic. The bodies were obtained by uniaxial pressing at 20 MPa and fired at temperatures of 850 ° C and 1050 ° C. The parameters studied were linear firing shrinkage, apparent density, water absorption and flexural rupture stress for the evaluation of the mechanical physical properties. The microstructure was observed by scanning electron microscopy and phase identification was performed by X-ray diffraction. The results showed that the waste changes the microstructure and properties of red ceramics. (author)

  3. Relative stiffness of flat conductor cables

    Science.gov (United States)

    Hankins, J. D.

    1976-01-01

    The measurement of the bending moment required to obtain a given deflection in short lengths of flat conductor cable (FCC) is presented in this report. Experimental data were taken on 10 different samples of FCC and normalized to express all bending moments (relative stiffness factor) in terms of a cable 5.1 cm (2.0 in.) in width. Data are presented in tabular and graphical form for the covenience of designers who may be interested in finding torques exerted on critical components by short lengths of FCC.

  4. Q-balls in flat potentials

    International Nuclear Information System (INIS)

    Copeland, Edmund J.; Tsumagari, Mitsuo I.

    2009-01-01

    We study the classical and absolute stability of Q-balls in scalar field theories with flat potentials arising in both gravity-mediated and gauge-mediated models. We show that the associated Q-matter formed in gravity-mediated potentials can be stable against decay into their own free particles as long as the coupling constant of the nonrenormalizable term is small, and that all of the possible three-dimensional Q-ball configurations are classically stable against linear fluctuations. Three-dimensional gauge-mediated Q-balls can be absolutely stable in the thin-wall limit, but are completely unstable in the thick-wall limit.

  5. Disposal of Rocky Flats residues as waste

    International Nuclear Information System (INIS)

    Dustin, D.F.; Sendelweck, V.S.

    1993-01-01

    Work is underway at the Rocky Flats Plant to evaluate alternatives for the removal of a large inventory of plutonium-contaminated residues from the plant. One alternative under consideration is to package the residues as transuranic wastes for ultimate shipment to the Waste Isolation Pilot Plant. Current waste acceptance criteria and transportation regulations require that approximately 1000 cubic yards of residues be repackaged to produce over 20,000 cubic yards of WIPP certified waste. The major regulatory drivers leading to this increase in waste volume are the fissile gram equivalent, surface radiation dose rate, and thermal power limits. In the interest of waste minimization, analyses have been conducted to determine, for each residue type, the controlling criterion leading to the volume increase, the impact of relaxing that criterion on subsequent waste volume, and the means by which rules changes may be implemented. The results of this study have identified the most appropriate changes to be proposed in regulatory requirements in order to minimize the costs of disposing of Rocky Flats residues as transuranic wastes

  6. Risk, media, and stigma at Rocky Flats

    International Nuclear Information System (INIS)

    Flynn, J.; Peters, E.; Mertz, C.K.; Slovic, P.

    1998-01-01

    Public responses to nuclear technologies are often strongly negative. Events, such as accidents or evidence of unsafe conditions at nuclear facilities, receive extensive and dramatic coverage by the news media. These news stories affect public perceptions of nuclear risks and the geographic areas near nuclear facilities. One result of these perceptions, avoidance behavior, is a form of technological stigma that leads to losses in property values near nuclear facilities. The social amplification of risk is a conceptual framework that attempts to explain how stigma is created through media transmission of information about hazardous places and public perceptions and decisions. This paper examines stigma associated with the US Department of energy's Rocky Flats facility, a major production plant in the nation's nuclear weapons complex, located near Denver, Colorado. This study, based upon newspaper analyses and a survey of Denver area residents, finds that the social amplification theory provides a reasonable framework for understanding the events and public responses that took place in regard to Rocky Flats during a 6-year period, beginning with an FBI raid of the facility in 1989

  7. Cosmological consequences of supersymmetric flat directions

    CERN Document Server

    Riva, Francesco; Sarkar, Subir; Giudice, Gian

    In this work we analyze various implications of the presence of large field vacum expectation values (VEVs) along supersymmetric flat direct ions during the early universe. First, we discuss supersymmetric leptogenesis and the grav itino bound. Supersym- metric thermal leptogenesis with a hierarchical right-han ded neutrino mass spectrum normally requires the mass of the lightest right-handed neu trino to be heavier than about 10 9 GeV. This is in conflict with the upper bound on the reheating t empera- ture which is found by imposing that the gravitinos generate d during the reheating stage after inflation do not jeopardize successful nucleosy nthesis. We show that a solution to this tension is actually already incorporated i n the framework, because of the presence of flat directions in the supersymmetric scalar potential. Massive right- handed neutrinos are efficiently produced non-thermally and the observed baryon asymmetry can be explained even for a reheating temperature respecting the grav- itino bound...

  8. Drift of a flat particle at longitudinal oscillations of gas in an open tube

    International Nuclear Information System (INIS)

    Zaripov, R G; Tkachenko, L A; R, Shaydullin L

    2014-01-01

    The particle motion is experimentally investigated at nonlinear oscillations of gas in the tube and in the external field near the open end in the shock-free mode. Dependence is obtained for the coordinates of the particle along the tube from time for various frequencies and amplitudes of displacement of the piston. Drift is set for a particle from the open end of the tube to the piston. It is determined that the particle moves into an external field at the open end outside the tube without appreciable oscillations. Detected position of the particle at the open end, wherein the particle does not perform drift towards the inside and outside of the tube

  9. Flat epithelial atypia and atypical ductal hyperplasia: carcinoma underestimation rate.

    Science.gov (United States)

    Ingegnoli, Anna; d'Aloia, Cecilia; Frattaruolo, Antonia; Pallavera, Lara; Martella, Eugenia; Crisi, Girolamo; Zompatori, Maurizio

    2010-01-01

    This study was carried out to determine the underestimation rate of carcinoma upon surgical biopsy after a diagnosis of flat epithelial atypia and atypical ductal hyperplasia and 11-gauge vacuum-assisted breast biopsy. A retrospective review was conducted of 476 vacuum-assisted breast biopsy performed from May 2005 to January 2007 and a total of 70 cases of atypia were identified. Fifty cases (71%) were categorized as pure atypical ductal hyperplasia, 18 (26%) as pure flat epithelial atypia and two (3%) as concomitant flat epithelial atypia and atypical ductal hyperplasia. Each group were compared with the subsequent open surgical specimens. Surgical biopsy was performed in 44 patients with atypical ductal hyperplasia, 15 patients with flat epithelial atypia, and two patients with flat epithelial atypia and atypical ductal hyperplasia. Five cases of atypical ductal hyperplasia were upgraded to ductal carcinoma in situ, three cases of flat epithelial atypia yielded one ductal carcinoma in situ and two cases of invasive ductal carcinoma, and one case of flat epithelial atypia/atypical ductal hyperplasia had invasive ductal carcinoma. The overall rate of malignancy was 16% for atypical ductal hyperplasia (including flat epithelial atypia/atypical ductal hyperplasia patients) and 20% for flat epithelial atypia. The presence of flat epithelial atypia and atypical ductal hyperplasia at biopsy requires careful consideration, and surgical excision should be suggested.

  10. Majorana flat bands in anisotropic systems

    Energy Technology Data Exchange (ETDEWEB)

    Mendler, Daniel; Kotetes, Panagiotis; Schoen, Gerd [Institut fuer theoretische Festkoerperphysik, Karlsruher Institut fuer Technologie (Germany)

    2015-07-01

    It has been recently proposed that topologically protected Majorana flat bands (MFBs) emerge in superconductors with nodal energy spectrum. In this work we introduce a new class of gapful superconductors, in which MFBs can occur due to strong anisotropy. The prototype system exhibiting this kind of behavior is the nematic p{sub x}+p{sub y} spinless superconductor, which supports an edge MFB with controllable bandwidth. Our proposal can be for instance experimentally implemented in topological superconductors engineered from i. semiconductors with tunable spin-orbit coupling or ii. topological insulator surfaces with intrinsic magnetic order in proximity to a conventional SC. By investigating the topological properties of both setups, we show that their unique features render them feasible platforms for manipulating the Majorana fermion bandstructure and realizing MFBs.

  11. The bifurcations of nearly flat origami

    Science.gov (United States)

    Santangelo, Christian

    Self-folding origami structures provide one means of fabricating complex, three-dimensional structures from a flat, two-dimensional sheet. Self-folding origami structures have been fabricated on scales ranging from macroscopic to microscopic and can have quite complicated structures with hundreds of folds arranged in complex patterns. I will describe our efforts to understand the mechanics and energetics of self-folding origami structures. Though the dimension of the configuration space of an origami structure scales with the size of the boundary and not with the number of vertices in the interior of the structure, a typical origami structure is also floppy in the sense that there are many possible ways to assign fold angles consistently. I will discuss our theoretical progress in understanding the geometry of the configuration space of origami. For random origami, the number of possible bifurcations grows surprisingly quickly even when the dimension of the configuration space is small. EFRI ODISSEI-1240441, DMR-0846582.

  12. Ultra flat ideal concentrators of high concentration

    Energy Technology Data Exchange (ETDEWEB)

    Chaves, Julio [IST, Physics Dept., Lisboa (Portugal); INETI-DER, Lisboa (Portugal); Collares-Pereira, Manuel [INETI-DER, Lisboa (Portugal)

    2000-07-01

    A new method for the design of nonimaging devices is presented. Its application to the design of ultra flat compact concentrators is analysed. These new concentrators are based on a combination of two stages: the first one is composed of a large number of small structures placed side by side and the second one is a very compact single device concentrating the radiation to the limit. These devices are ideal for 2D. These compact designs are much more compact than the traditional ones like lens-mirror combinations or parabolic primaries with nonimaging secondaries. Besides, they can be designed for any acceptance angle, while the traditional ones are limited to small acceptance angles. (Author)

  13. Theory of Fermi Liquid with Flat Bands

    Science.gov (United States)

    Khodel, V. A.

    2018-04-01

    A self-consistent theory of Fermi systems hosting flat bands is developed. Compared with an original model of fermion condensation, its key point consists in proper accounting for mixing between condensate and non-condensate degrees of freedom that leads to formation of a non-BCS gap Υ (p) in the single-particle spectrum. The results obtained explain: (1) the two-gap structure of spectra of single-particle excitations of electron systems of copper oxides, revealed in ARPES studies, (2) the role of violation of the topological stability of the Landau state in the arrangement of the T-x phase diagram of this family of high-T_c superconductors, (3) the topological nature of a metal-insulator transition, discovered in homogeneous two-dimensional low-density electron liquid of MOSFETs more than 20 years ago.

  14. NEPA/CERCLA integration at Rocky Flats

    International Nuclear Information System (INIS)

    Schassburger, R.J.

    1991-01-01

    Integration of two laws, the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) and the National Environmental Policy Act (NEPA) was mandated by the US Department of Energy (DOE) with issuance of DOE Order 5400.4 in October 6, 1989. NEPA documentation is required for all federal actions to thereby consider the impacts of such actions prior to the action taking place. On the other hand, CERCLA actions taken by the US Environmental Protection Agency (EPA) at non-federal and federal sites do not normally take NEPA into consideration, although it is not exempted at federal sites. EPA claims that CERCLA is functionally equivalent to N-EPA and therefore NEPA is not required. Although EPA maintains the functional equivalency of the two laws and formerly resisted to recognize NEPA even in Inter-Agency Agreements (IAGs), Rocky Flats has been integrating the two laws within documents to avoid duplication of information and effort

  15. Transparent Solar Concentrator for Flat Panel Display

    Science.gov (United States)

    Yeh, Chia-Hung; Chang, Fuh-Yu; Young, Hong-Tsu; Hsieh, Tsung-Yen; Chang, Chia-Hsiung

    2012-06-01

    A new concept of the transparent solar concentrator for flat panel display is experimentally demonstrated without adversely affecting the visual effects. The solar concentrator is based on a solar light-guide plate with micro prisms, not only increasing the absorption area of solar energy but also enhancing the conversion efficiency. The incident light is guided by the designed solar light-guide plate according to the total internal reflection (TIR), and converted into electrical power by photovoltaic solar cells. The designed transparent solar concentrator was made and measured with high transparency, namely 94.8%. The developed solar energy system for display can store energy and supply the bias voltage to light on two light-emitting diodes (LEDs) successfully.

  16. TRANSVERSE MODES FOR FLAT INTER-BUNCH WAKES*

    CERN Document Server

    Burov, A

    2013-01-01

    If inter-bunch wake fields are flat, i.e. their variations over a bunch length can be neglected, all coherent modes have the same coupled-bunch structure, provided the bunches can be treated as identical by their inner qualities (train theorem). If a flat feedback is strong enough, the transverse modes are single-bunch, provided the inter-bunch wakes are also flat (damper theorem).

  17. Development of Partial Tubular Flat Knitting Fabric Composite Preform

    Directory of Open Access Journals (Sweden)

    Jiang Wei Qing

    2016-01-01

    Full Text Available After building some structures of partial tubular flat knitting fabric composite preform, the influencing factor on tubular section was analyzed and the fabric was knitted selectively. The partial tubular flat knitting fabric composite preform were Knitted by changing different yarn, row number and two-sided partial tubular flat knitting fabric. Multilayer sheet would be got after hot pressing and it has big market prospects and good application value.

  18. Flat connection, conformal field theory and quantum group

    International Nuclear Information System (INIS)

    Kato, Mitsuhiro.

    1989-07-01

    General framework of linear first order differential equation for four-point conformal block is studied by using flat connection. Integrability and SL 2 invariance restrict possible form of flat connection. Under a special ansatz classical Yang-Baxter equation appears as an integrability condition and the WZW model turns to be unique conformal field theory in that case. Monodromy property of conformal block can be easily determined by the flat connection. 11 refs

  19. Criteria impacting shipments of Rocky Flats Plant radioactive mixed wastes

    International Nuclear Information System (INIS)

    Clawson, R.L.; Eide, J.H.

    1992-05-01

    Westinghouse Hanford Company, Transportation and Packaging Division, under contract for the Los Alamos Technology Office-Rocky Flats Plant, has developed this synopsis report to be used as a reference in the development of the Rocky Flats Plant Comprehensive Treatment and Management Plan and the Rocky Flats Plant Residue Elimination Plan. This report represents the criteria for packaging, shipping, and transporting Rocky Flats Plant radioactive mixed wastes. It is a compilation of state and federal regulations, US Department of Energy orders, and acceptance criteria specific to US Department of Energy radioactive mixed waste treatment, storage and disposal facilities

  20. 3D flat holography: entropy and logarithmic corrections

    International Nuclear Information System (INIS)

    Bagchi, Arjun; Basu, Rudranil

    2014-01-01

    We compute the leading corrections to the Bekenstein-Hawking entropy of the Flat Space Cosmological (FSC) solutions in 3D flat spacetimes, which are the flat analogues of the BTZ black holes in AdS 3 . The analysis is done by a computation of density of states in the dual 2D Galilean Conformal Field Theory and the answer obtained by this matches with the limiting value of the expected result for the BTZ inner horizon entropy as well as what is expected for a generic thermodynamic system. Along the way, we also develop other aspects of holography of 3D flat spacetimes

  1. An epidemiologic study of flat foot in Iran

    Directory of Open Access Journals (Sweden)

    Alamy B

    1997-07-01

    Full Text Available Among 880 studied feet of 7-14 years old children 6.9% suffered mild and severe flat foot. 53.8% of the affected children were symptomatic. As 40.1% of the general population experiences symptoms, in a small proportion of affected persons, symptoms are due to flat foot. The prevalence of symptoms rises with increasing severity of the disorder. In this article, reviewing general aspects of flat food, prevalence and other epidemiological aspects of flat foot for the first time in Iran have been presented

  2. Flat synchronizations in spherically symmetric space-times

    International Nuclear Information System (INIS)

    Herrero, Alicia; Morales-Lladosa, Juan Antonio

    2010-01-01

    It is well known that the Schwarzschild space-time admits a spacelike slicing by flat instants and that the metric is regular at the horizon in the associated adapted coordinates (Painleve-Gullstrand metric form). We consider this type of flat slicings in an arbitrary spherically symmetric space-time. The condition ensuring its existence is analyzed, and then, we prove that, for any spherically symmetric flat slicing, the densities of the Weinberg momenta vanish. Finally, we deduce the Schwarzschild solution in the extended Painleve-Gullstrand-LemaItre metric form by considering the coordinate decomposition of the vacuum Einstein equations with respect to a flat spacelike slicing.

  3. Evaluation of Flat Surface Temperature Probes

    Science.gov (United States)

    Beges, G.; Rudman, M.; Drnovsek, J.

    2011-01-01

    The objective of this paper is elaboration of elements related to metrological analysis in the field of surface temperature measurement. Surface temperature measurements are applicable in many fields. As examples, safety testing of electrical appliances and a pharmaceutical production line represent case studies for surface temperature measurements. In both cases correctness of the result of the surface temperature has an influence on final product safety and quality and thus conformity with specifications. This paper deals with the differences of flat surface temperature probes in measuring the surface temperature. For the purpose of safety testing of electrical appliances, surface temperature measurements are very important for safety of the user. General requirements are presented in European standards, which support requirements in European directives, e.g., European Low Voltage Directive 2006/95/EC and pharmaceutical requirements, which are introduced in official state legislation. This paper introduces a comparison of temperature measurements of an attached thermocouple on the measured surface and measurement with flat surface temperature probes. As a heat generator, a so called temperature artifact is used. It consists of an aluminum plate with an incorporated electrical heating element with very good temperature stability in the central part. The probes and thermocouple were applied with different forces to the surface in horizontal and vertical positions. The reference temperature was measured by a J-type fine-wire (0.2 mm) thermocouple. Two probes were homemade according to requirements in the European standard EN 60335-2-9/A12, one with a fine-wire (0.2 mm) thermocouple and one with 0.5mm of thermocouple wire diameter. Additional commercially available probes were compared. Differences between probes due to thermal conditions caused by application of the probe were found. Therefore, it can happen that measurements are performed with improper equipment or

  4. Flat Files - JSNP | LSDB Archive [Life Science Database Archive metadata

    Lifescience Database Archive (English)

    Full Text Available switchLanguage; BLAST Search Image Search Home About Archive Update History Data ... Data file File name: jsnp_flat_files File URL: ftp://ftp.biosciencedbc.jp/archiv...his Database Database Description Download License Update History of This Database Site Policy | Contact Us Flat Files - JSNP | LSDB Archive ...

  5. Programming the shape-shifting of flat soft matter

    NARCIS (Netherlands)

    van Manen, T.; Janbaz, S.; Zadpoor, A.A.

    2018-01-01

    Shape-shifting of flat materials into the desired 3D configuration is an alternative design route for fabrication of complex 3D shapes, which provides many benefits such as access to the flat material surface and the ability to produce well-described motions. The advanced production techniques

  6. Flat oysters in the Eierlandse Gat, Wadden Sea

    NARCIS (Netherlands)

    Have, van der T.M.; Kamermans, P.; Zee, van der E.M.

    2018-01-01

    This report presents the results of a short survey of flat oysters (Ostrea edulis) in the Western Wadden Sea. Ten sites were visited and flat oysters were found on nine locations in the Eijerlandse gat. Empty cockleshells and live and dead Pacific oysters provided the main settlement substrate. The

  7. Converting nested algebra expressions into flat algebra expressions

    NARCIS (Netherlands)

    Paredaens, J.; Van Gucht, D.

    1992-01-01

    Nested relations generalize ordinary flat relations by allowing tuple values to be either atomic or set valued. The nested algebra is a generalization of the flat relational algebra to manipulate nested relations. In this paper we study the expressive power of the nested algebra relative to its

  8. Detecting areal changes in tidal flats after sea dike construction ...

    Indian Academy of Sciences (India)

    The main objective of this study was to estimate changes in the area of tidal flats that occurred after sea dike construction on the western coast of South Korea using Landsat-TM images. Applying the ISODATA method of unsupervised classification for Landsat-TM images, the tidal flats were identified, and the resulting areas ...

  9. 75 FR 12981 - Eligibility for Commercial Flats Failing Deflection

    Science.gov (United States)

    2010-03-18

    ... applicable only to automation flats, for all commercial flat-size mail except saturation and high-density...[supreg] pricing. If automation prices are denied, pieces that are prepared to be part of full-service IMb... compliance, but at additional cost; and quarter-folding would not work well with any inserts. Also, there was...

  10. Temporal bed level variations in the Yangtze tidal flats (abstract)

    NARCIS (Netherlands)

    Yan, H.; Van Prooijen, B.C.

    2013-01-01

    The Yangtze River is one of the largest rivers in the world and the longest one in Asia. Its estuary forms an important entrance for shipping, but is also a key ecological system. Especially the inter-tidal flats are valuable habitats. The health and integrity of the estuarine tidal flat are however

  11. Generation of shape-invariant flat-top laser beams

    CSIR Research Space (South Africa)

    Ait-Ameur, K

    2015-02-01

    Full Text Available A great number of laser applications need in place of the usual Gaussian beam a flat-top intensity profile in the focal plane of a focusing lens. In general the transformation of the laser beam from the Gaussian to the flat-top shape is made by a...

  12. Forest Landscape Assessment Tool (FLAT): rapid assessment for land management

    Science.gov (United States)

    Lisa Ciecko; David Kimmett; Jesse Saunders; Rachael Katz; Kathleen L. Wolf; Oliver Bazinet; Jeffrey Richardson; Weston Brinkley; Dale J. Blahna

    2016-01-01

    The Forest Landscape Assessment Tool (FLAT) is a set of procedures and tools used to rapidly determine forest ecological conditions and potential threats. FLAT enables planners and managers to understand baseline conditions, determine and prioritize restoration needs across a landscape system, and conduct ongoing monitoring to achieve land management goals. The rapid...

  13. 75 FR 29582 - Yukon Flats National Wildlife Refuge, Fairbanks, AK

    Science.gov (United States)

    2010-05-26

    ... from climate change. Fourth, infrastructure associated with access corridors from the proposed exchange... statement (EIS) for a Proposed Land Exchange in the Yukon Flats National Wildlife Refuge (NWR, Refuge). We... this notice, we finalize the EIS process for a Proposed Land Exchange in the Yukon Flats NWR. In...

  14. Mussel beds are biological power stations on intertidal flats

    NARCIS (Netherlands)

    Engel, Friederike G.; Alegria, Javier; Andriana, Rosyta; Donadi, Serena; Gusmao, Joao B.; van Leeuwe, Maria A.; Matthiessen, Birte; Eriksson, Britas Klemens

    2017-01-01

    Intertidal flats are highly productive areas that support large numbers of invertebrates, fish, and birds. Benthic diatoms are essential for the function of tidal flats. They fuel the benthic food web by forming a thin photosynthesizing compartment in the top-layer of the sediment that stretches

  15. FLAT FEET OF DHE CHILDREN IN PRE-SCHOOL AGE

    Directory of Open Access Journals (Sweden)

    Admira Koničanin

    2011-03-01

    Full Text Available Subjekt : Of this research are flat feet of the children of both sexes in pre-school age children Aim : Of the research is confirm wheter is exists or flat feel of the children of both sexes in pre-school age.

  16. Eight year experience in open ended instrumentation laboratory

    Science.gov (United States)

    Marques, Manuel B.; Rosa, Carla C.; Marques, Paulo V. S.

    2015-10-01

    When designing laboratory courses in a Physics Major we consider a range of objectives: teaching Physics; developing lab competencies; instrument control and data acquisition; learning about measurement errors and error propagation; an introduction to project management; team work skills and scientific writing. But nowadays we face pressure to decrease laboratory hours due to the cost involved. Many universities are replacing lab classes for simulation activities, hiring PhD. and master students to give first year lab classes, and reducing lab hours. This leads to formatted lab scripts and poor autonomy of the students, and failure to enhance creativity and autonomy. In this paper we present our eight year experience with a laboratory course that is mandatory in the third year of Physics and Physical Engineering degrees. Since the students had previously two standard laboratory courses, we focused on teaching instrumentation and giving students autonomy. The course is divided in two parts: one third is dedicated to learn computer controlled instrumentation and data acquisition (based in LabView); the final 2/3 is dedicated to a group project. In this project, the team (2 or 3 students) must develop a project and present it in a typical conference format at the end of the semester. The project assignments are usually not very detailed (about two or three lines long), giving only general guidelines pointing to a successful project (students often recycle objectives putting forward a very personal project); all of them require assembling some hardware. Due to our background, about one third of the projects are related to Optics.

  17. Creating Futures through Participation and open-ended experiments

    DEFF Research Database (Denmark)

    Husted, Mia; Bladt, Mette; Tofteng, Ditte Maria Børglum

    This workshop will engage participants in a process that enables ‘ordinary people’ to take responsibility for creating new futures and to bring about new anticipations for democratic developments of local and societal issues. Founded in the Critical Utopian Action Research Tradition, the workshop...... will engage participants in a brief version of a Future Creating Workshop....

  18. Open-Ended Narrative and Moral Formation | Klaasen | Acta ...

    African Journals Online (AJOL)

    The PDF file you selected should load here if your Web browser has a PDF reader plug-in installed (for example, a recent version of Adobe Acrobat Reader). If you would like more information about how to print, save, and work with PDFs, Highwire Press provides a helpful Frequently Asked Questions about PDFs.

  19. Designing for social interaction in open-ended play environments

    NARCIS (Netherlands)

    de Valk, L.; Bekker, T.; Eggen, J.H.

    2015-01-01

    Interactive technology is becoming more strongly integrated in innovative play solutions. As play is often a social experience, understanding the dynamic social context in which such play takes place is an essential step in designing new interactive play environments. In this paper, we explore the

  20. Control of open end plasma flow utilizing orbital stochasticity

    International Nuclear Information System (INIS)

    Hojo, Hitoshi

    1995-01-01

    It has been known that the control of plasma outside the confinement region of diverter plasma and others in a magnetic field confinement device is very important for improveing the confinement of bulk plasma. The control of plasma outside a confinement region bears two roles, one is the reduction of the thermal load on a diverter plate and others due to the plasma particles lost from the confinement region, and another is the restriction of the back flow of cold plasma and impurities generated outside the confinement region to a bulk plasma region. In this study, the new method of controlling plasma outside a confinement region called magnetic diverter is considered. To the plasma particles advancing along magnetic force lines, the reflection and capture of the plasma particles occur in the region of orbital stochasticity, and the thermal load on an end plate and the reverse flow to a bulk plasma region are restricted. The numerical computation model used regarding the particle control utilizing the orbital stochasticity and the results of calculating the orbit of plasma particles in a magnetic field are reported. (K.I.)

  1. Visualizing Learning in Open - Ended Problem Solving in the Arts

    Directory of Open Access Journals (Sweden)

    Walter Bender

    2015-01-01

    Full Text Available En su artículo, "Hacer el aprendizaje visible" (Urrea y Bender, 2012, los autores describen un marco que hace que los resultados de las iniciativas de reforma de educación a gran escala sean visibles, y comprensibles y aplicables a todos los públicos: administr adores educativos, educadores, padres de familia, y los propios niños. En este trabajo, examinamos detalladamente los datos de un concurso de programación entre escuelas del proyecto "Conectándonos", una iniciativa de la computación uno a uno implementado en Costa Rica por la Fundación Quirós Tanzi y el Ministerio de Educación Pública. Aplicamos este marco a los proyectos de Bloques de la Tortuga de 45 niños. Se demuestra una correlación entre la aplicación de nuestro marco al trabajo de los niños y sus res ultados de aprendizaje, evaluados subjetivamente. Argumentamos que al demostrar la eficacia de un mecanismo de evaluación de actividades de resolución de problemas abiertos, eliminamos un obstáculo para hacer las artes una parte más dominante de la educaci ón primaria.

  2. On designing open-ended interpretations for collaborative design exploration

    DEFF Research Database (Denmark)

    Mattelmäki, Tuuli; Brandt, Eva; Vaajakallio, Kirsikka

    2011-01-01

    User-centred design is a widely acknowledged practice. Much attention has been paid to the methods, tools and processes on how to conduct design research and field studies with and about ‘users’ and existing or possible ‘contexts of use’. The underlying driver is that the design team will be bett...... interpretations which lead to empathic understanding and engagement. Rather than communicating the final results, design in supporting collaboration is applied in a process of exploring what it is that will create value for specific people....... at designing if they have an empathic understanding of the people to design with and for. Currently, more effort is invested in engaging various stakeholders in collaborative design activities that nurture an attitude of human-centredness as a strategy. Empathic design approaches are essential...... that they can allow and inspire new individual interpretations for various participants in the collaborative design processes, which include users, designers and other stakeholders. What is argued for here is the value of incompleteness of field study outcomes as it invites sense-making through making new...

  3. Exploring Open-Ended Design Space of Mechatronic Systems

    DEFF Research Database (Denmark)

    Fan, Zhun; Wang, J.; Goodman, E.

    2004-01-01

    To realize design automation of mechatronic systems, there are two major issues to be dealt with: open-topology generation of mechatronic systems and simulation or analysis of those models. For the first issue, we exploit the strong topology exploration capability of genetic programming to create...... and evolve structures representing mechatronic systems. With the help of ERCs (ephemeral random constants) in genetic programming, we can also evolve the sizing of mechatronic system components along with the structures. The second issue, simulation and analysis of those system models, is made more complex...... when they represent mixed-energy-domain systems. We take advantage of bond graphs as a tool for multi- or mixed-domain modeling and simulation of mechatronic systems. Because there are many considerations in mechatronic system design that are not completely captured by a bond graph, we would like...

  4. Progress In Research On Open - Ended Magnetic Traps

    International Nuclear Information System (INIS)

    Kruglyakov, E. P.; Burdakov, A. V.; Ivanov, A. A.

    2006-01-01

    At present, three modern types of mirror machines for plasma confinement and heating exist in Novosibirsk (Multi-mirror,-GOL-3, Gas Dynamic Trap,-GDT, and Tandem Mirror,- AMBAL-M). From the engineering point of view all these systems are very attractive because of simple axisymmetric geometry of magnetic configurations. In this paper, the status of GOL-3 and GDT machines is presented. The most crucial experiments for the mirror concept are described such as a demonstration of different principles of suppression of longitudinal electron heat conductivity (GDT, GOL-3), finding of MHD stable regimes of confinement of high β (more than 0.4) plasma in axisymmetric geometry of magnetic field, an effective heating of a dense plasma (of order of 10 21 m-3) by high current relativistic electron beam (GOL-3), etc. In the case of multi-mirror geometry (GOL-3) significant increase of confinement time of hot plasma (up to several tens times) was obtained in comparison with single mirror geometry. Besides, electron heating (up to 2 keV) in result of high current electron beam -- plasma interaction, the heating of ions (up to 2 keV) was discovered in the multi-mirror geometry (55 mirror cells with total length of the trap equal to 12 meters). There was no any effect of ion heating in the single mirror geometry. The reasons of appearance of the ion heating in multi-mirror geometry are discussed. It should be mentioned that on the basis of the GOL-3 and GDT one can obtain an important information for ITER and for future fusion program. In the case of GOL-3 the longitudinal energy density flux of plasma after heating by REB can be so high as 50 MJ/m2. A lot of experiments can be made on plasma-wall interaction (evaporation, erosion and ionization of wall material, propagation of the impurity ions along magnetic field lines at long distances, etc). Some of these experiments are described in this paper. Using principle of confinement of 'warm' collisional plasma placed in gas dynamic trap (GDT) together with oblique injection of fast atoms of D and T one can create a powerful 14 MeV neutron source for constructed materials tests of future fusion reactors with a moderate irradiation area (about 1 square meter) and, accordingly, with low tritium consumption. It should be mentioned that there is no one candidate to the plasma based neutron source with such moderate consumption of tritium (about 150 gram/year) and electric power (60 MW). The experimental results with NB injection of 4 MW are described and the experiments of the next step (GDT-U) with 10 MW injection are discussed

  5. Spatially varying index of refraction: An open ended undergraduate topic

    International Nuclear Information System (INIS)

    Krueger, D.A.

    1980-01-01

    There are many commonplace examples of waves moving along a curved path in an inhomogeneous media. There are reports of a simple lecture demonstration of light bending in a sugar solution being used to motivate students in physics, geophysics, and acoustics courses. For those students who wish to pursue this topic we discuss many avenues of additional research. With relatively simple equipment one can measure the index of refraction n (y,t) and its first and second spatial derivatives as well as the time dependence. The analysis can be approached from a generalization of Snell's law, the equations for the eikonal, Fermat's principle, and the classical approximation and analogies with trajectories of particles

  6. Comments on open-ended magnetic systems for fusion

    International Nuclear Information System (INIS)

    Post, R.F.

    1990-01-01

    Differentiating characteristics of magnetic confinement systems having externally generated magnetic fields that are ''open'' are listed and discussed in the light of their several potential advantages for fusion power systems. It is pointed out that at this stage of fusion research ''high-Q'' (as deduced from long energy confinement times) is not necessarily the most relevant criterion by which to judge the potential of alternate fusion approaches for the economic generation of fusion power. An example is given of a hypothetical open-geometry fusion power system where low-Q operation is essential to meeting one of its main objectives (low neutron power flux)

  7. Design of flat pneumatic artificial muscles

    Science.gov (United States)

    Wirekoh, Jackson; Park, Yong-Lae

    2017-03-01

    Pneumatic artificial muscles (PAMs) have gained wide use in the field of robotics due to their ability to generate linear forces and motions with a simple mechanism, while remaining lightweight and compact. However, PAMs are limited by their traditional cylindrical form factors, which must increase radially to improve contraction force generation. Additionally, this form factor results in overly complicated fabrication processes when embedded fibers and sensor elements are required to provide efficient actuation and control of the PAMs while minimizing the bulkiness of the overall robotic system. In order to overcome these limitations, a flat two-dimensional PAM capable of being fabricated using a simple layered manufacturing process was created. Furthermore, a theoretical model was developed using Von Karman’s formulation for large deformations and the energy methods. Experimental characterizations of two different types of PAMs, a single-cell unit and a multi-cell unit, were performed to measure the maximum contraction lengths and forces at input pressures ranging from 0 to 150 kPa. Experimental data were then used to verify the fidelity of the theoretical model.

  8. Workpiece Temperature Variations During Flat Peripheral Grinding

    Science.gov (United States)

    Smirnov, Vitalii A.; Repko, Aleksandr V.

    2018-06-01

    The paper presents the results of researches of temperature variations during flat peripheral grinding. It is shown that the temperature variations of the workpiece can reach 25...30% of the average values, which can lead to some thermal defects. A nonlinear two-dimensional thermophysical grinding model is suggested. It takes into account local changes in the cutting conditions: the fluctuation of the cut layer and the cutting force, the thermal impact of the cutting grains, and the presence of surface cavities in the intermittent wheel. For the numerical solution of the problem, the method of finite differences is adapted. Researches of the method stability and convergence are made, taking into account the specific nature of the problem. A high accuracy of the approximation of the boundary conditions and the nonlinear heat equation is provided. An experimental verification of the proposed thermophysical model was carried out with the use of installation for simultaneous measurement of the grinding force and temperature. It is shown that the discrepancy between the theoretical and experimental values of the grinding temperature does not exceed 5%. The proposed thermophysical model makes it possible to predict with high accuracy the temperature variations during grinding by the wheel periphery.

  9. Rocky Flats Plant fluidized-bed incinerator

    International Nuclear Information System (INIS)

    Meile, L.J.; Meyer, F.G.; Johnson, A.J.; Ziegler, D.L.

    1982-01-01

    Laboratory and pilot-scale testing of a fluidized-bed incineration process for radioactive wastes led to the installation of an 82-kg/hr demonstration unit at Rocky Flats Plant in 1978. Design philosophy and criteria were formulated to fulfill the needs and objectives of an improved radwaste-incineration system. Unique process concepts include low-temperature (550 0 C), flameless, fluidized-bed combustion and catalytic afterburning; in-situ neutralization of acid gases; and dry off-gas cleanup. Detailed descriptions of the process and equipment are presented along with a summary of the equipment and process performance during a 2-1/2 year operational-testing period. Equipment modifications made during the test period are described. Operating personnel requirements for solid-waste burning are shown to be greater than those required for liquid-waste incineration; differences are discussed. Process-utility and raw-materials consumption rates for full-capacity operation are presented and explained. Improvements in equipment and operating procedures are recommended for any future installations. Process flow diagrams, an area floor plan, a process-control-system schematic, and equipment sketches are included

  10. Flat Surface Damage Detection System (FSDDS)

    Science.gov (United States)

    Williams, Martha; Lewis, Mark; Gibson, Tracy; Lane, John; Medelius, Pedro; Snyder, Sarah; Ciarlariello, Dan; Parks, Steve; Carrejo, Danny; Rojdev, Kristina

    2013-01-01

    The Flat Surface Damage Detection system (FSDDS} is a sensory system that is capable of detecting impact damages to surfaces utilizing a novel sensor system. This system will provide the ability to monitor the integrity of an inflatable habitat during in situ system health monitoring. The system consists of three main custom designed subsystems: the multi-layer sensing panel, the embedded monitoring system, and the graphical user interface (GUI). The GUI LABVIEW software uses a custom developed damage detection algorithm to determine the damage location based on the sequence of broken sensing lines. It estimates the damage size, the maximum depth, and plots the damage location on a graph. Successfully demonstrated as a stand alone technology during 2011 D-RATS. Software modification also allowed for communication with HDU avionics crew display which was demonstrated remotely (KSC to JSC} during 2012 integration testing. Integrated FSDDS system and stand alone multi-panel systems were demonstrated remotely and at JSC, Mission Operations Test using Space Network Research Federation (SNRF} network in 2012. FY13, FSDDS multi-panel integration with JSC and SNRF network Technology can allow for integration with other complementary damage detection systems.

  11. Prunus hybrids rootstocks for flat peach

    Directory of Open Access Journals (Sweden)

    Pilar Legua

    2012-02-01

    Full Text Available Peach (Prunus persica L. is the most important stone fruit tree grown in Spain and is the second most important fruit crop in Europe. The influence of eight Prunus rootstocks (GF-677, Krymsk® 86, PADAC 97-36, PADAC 99-05, PADAC 9912-03, PADAC 0024-01, PAC 0021-01 and PAC 0022-01 on vigor, yield and fruit quality traits of 'UFO 3' flat peach cultivar was studied. The highest trunk cross sectional area was exhibited by GF-677 and the lowest by PADAC 99-05, while intermediate values were found on the other rootstocks. The highest yield efficiency was found on PADAC 99-05, PAC 0021-01, PAC 0022-01 and PADAC 0024-01 and the lowest was shown on Krymsk® 86. The fruit quality parameters measured were color, fruit and stone weights, equatorial diameter, pulp thickness, pulp yield, firmness, pH, soluble solids content and titratable acidity. 'UFO 3' grafted on GF-677 resulted in the largest fruit weight, while the smallest was on PADAC 99-05. Fruits of 'UFO 3' showed a tendency to have higher firmness, higher red colored skin and RI when grafted on PADAC 99-05.

  12. Beam uniformity of flat top lasers

    Science.gov (United States)

    Chang, Chao; Cramer, Larry; Danielson, Don; Norby, James

    2015-03-01

    Many beams that output from standard commercial lasers are multi-mode, with each mode having a different shape and width. They show an overall non-homogeneous energy distribution across the spot size. There may be satellite structures, halos and other deviations from beam uniformity. However, many scientific, industrial and medical applications require flat top spatial energy distribution, high uniformity in the plateau region, and complete absence of hot spots. Reliable standard methods for the evaluation of beam quality are of great importance. Standard methods are required for correct characterization of the laser for its intended application and for tight quality control in laser manufacturing. The International Organization for Standardization (ISO) has published standard procedures and definitions for this purpose. These procedures have not been widely adopted by commercial laser manufacturers. This is due to the fact that they are unreliable because an unrepresentative single-pixel value can seriously distort the result. We hereby propose a metric of beam uniformity, a way of beam profile visualization, procedures to automatically detect hot spots and beam structures, and application examples in our high energy laser production.

  13. Commercial Decommissioning at DOE's Rocky Flats

    International Nuclear Information System (INIS)

    Freiboth, C.; Sandlin, N.; Schubert, A.; Hansen, S.

    2002-01-01

    Due in large part to the number of nuclear facilities that make up the DOE complex, DOE-EM work has historically been paperwork intensive and driven by extensive regulations. Requirements for non-nuclear facilities are often grouped with those of nuclear facilities, driving up costs. Kaiser-Hill was interested in applying a commercial model to demolition of these facilities and wanted to apply necessary and sufficient standards to the work activities, but avoid applying unnecessary requirements. Faced with demolishing hundreds of uncontaminated or non-radiologically contaminated facilities, Kaiser-Hill has developed a subcontracting strategy to drastically reduce the cost of demolishing these facilities at Rocky Flats. Aiming to tailor the demolition approach of such facilities to more closely follow commercial practices, Kaiser-Hill recently released a Request for Proposals (RFP) for the demolition of the site's former central administration facility. The RFP significantly reduced requirements for compliance with specific DOE directives. Instead, the RFP required subcontractors to comply with health and safety requirements commonly found in the demolition of similar facilities in a commercial setting. This resulted in a number of bids from companies who have normally not bid on DOE work previously and at a reduced cost over previous approaches. This paper will discuss the details of this subcontracting strategy

  14. Photonic crystal based polarization insensitive flat lens

    International Nuclear Information System (INIS)

    Turduev, M; Bor, E; Kurt, H

    2017-01-01

    The paper proposes a new design of an inhomogeneous artificially created photonic crystal lens structure consisting of annular dielectric rods to efficiently focus both transverse electric and transverse magnetic polarizations of light into the same focal point. The locations of each individual cell that contains the annular dielectric rods are determined according to a nonlinear distribution function. The inner and outer radii of the annular photonic dielectric rods are optimized with respect to the polarization insensitive frequency response of the transmission spectrum of the lens structure. The physical background of the polarization insensitive focusing mechanism is investigated in both spatial and frequency domains. Moreover, polarization independent wavefront transformation/focusing has been explored in detail by investigating the dispersion relation of the structure. Corresponding phase index distribution of the lens is attained for polarization insensitive normalized frequency range of a / λ   =  0.280 and a / λ   =  0.300, where a denotes the lattice constant of the designed structure and λ denotes the wavelength of the incident light. We show the wave transformation performance and focal point movement dynamics for both polarizations of the lens structure by specially adjusting the length of the structure. The 3D finite-difference time domain numerical analysis is also performed to verifiy that the proposed design is able to focus the wave regardless of polarization into approximately the same focal point (difference between focal distances of both polarizations stays below 0.25 λ ) with an operating bandwidth of 4.30% between 1476 nm and 1541 nm at telecom wavelengths. The main superiorities of the proposed lens structure are being all dielectric and compact, and having flat front and back surfaces, rendering the proposed lens design more practical in the photonic integration process in various applications such as optical switch

  15. A quantum kinematics for asymptotically flat gravity

    Science.gov (United States)

    Campiglia, Miguel; Varadarajan, Madhavan

    2015-07-01

    We construct a quantum kinematics for asymptotically flat gravity based on the Koslowski-Sahlmann (KS) representation. The KS representation is a generalization of the representation underlying loop quantum gravity (LQG) which supports, in addition to the usual LQG operators, the action of ‘background exponential operators’, which are connection dependent operators labelled by ‘background’ su(2) electric fields. KS states have, in addition to the LQG state label corresponding to one dimensional excitations of the triad, a label corresponding to a ‘background’ electric field that describes three dimensional excitations of the triad. Asymptotic behaviour in quantum theory is controlled through asymptotic conditions on the background electric fields that label the states and the background electric fields that label the operators. Asymptotic conditions on the triad are imposed as conditions on the background electric field state label while confining the LQG spin net graph labels to compact sets. We show that KS states can be realised as wave functions on a quantum configuration space of generalized connections and that the asymptotic behaviour of each such generalized connection is determined by that of the background electric fields which label the background exponential operators. Similar to the spatially compact case, the Gauss law and diffeomorphism constraints are then imposed through group averaging techniques to obtain a large sector of gauge invariant states. It is shown that this sector supports a unitary action of the group of asymptotic rotations and translations and that, as anticipated by Friedman and Sorkin, for appropriate spatial topology, this sector contains states that display fermionic behaviour under 2π rotations.

  16. Flat norm decomposition of integral currents

    Directory of Open Access Journals (Sweden)

    Sharif Ibrahim

    2016-05-01

    Full Text Available Currents represent generalized surfaces studied in geometric measure theory. They range from relatively tame integral currents representing oriented compact manifolds with boundary and integer multiplicities, to arbitrary elements of the dual space of differential forms. The flat norm provides a natural distance in the space of currents, and works by decomposing a $d$-dimensional current into $d$- and (the boundary of $(d+1$-dimensional pieces in an optimal way.Given an integral current, can we expect its at norm decomposition to be integral as well? This is not known in general, except in the case of $d$-currents that are boundaries of $(d+1$-currents in $\\mathbb{R}^{d+1}$ (following results from a corresponding problem on the $L^1$ total variation ($L^1$TV of functionals. On the other hand, for a discretized at norm on a finite simplicial complex, the analogous statement holds even when the inputs are not boundaries. This simplicial version relies on the total unimodularity of the boundary matrix of the simplicial complex; a result distinct from the $L^1$TV approach.We develop an analysis framework that extends the result in the simplicial setting to one for $d$-currents in $\\mathbb{R}^{d+1}$, provided a suitable triangulation result holds. In $\\mathbb{R}^2$, we use a triangulation result of Shewchuk (bounding both the size and location of small angles, and apply the framework to show that the discrete result implies the continuous result for $1$-currents in $\\mathbb{R}^2$ .

  17. On-Line Flatness Measurement in the Steelmaking Industry

    Directory of Open Access Journals (Sweden)

    Rubén Usamentiaga

    2013-08-01

    Full Text Available Shape is a key characteristic to determine the quality of outgoing flat-rolled products in the steel industry. It is greatly influenced by flatness, a feature to describe how the surface of a rolled product approaches a plane. Flatness is of the utmost importance in steelmaking, since it is used by most downstream processes and customers for the acceptance or rejection of rolled products. Flatness sensors compute flatness measurements based on comparing the length of several longitudinal fibers of the surface of the product under inspection. Two main different approaches are commonly used. On the one hand, most mechanical sensors measure the tensile stress across the width of the rolled product, while manufacturing and estimating the fiber lengths from this stress. On the other hand, optical sensors measure the length of the fibers by means of light patterns projected onto the product surface. In this paper, we review the techniques and the main sensors used in the steelmaking industry to measure and quantify flatness defects in steel plates, sheets and strips. Most of these techniques and sensors can be used in other industries involving rolling mills or continuous production lines, such as aluminum, copper and paper, to name a few. Encompassed in the special issue, State-of-the-Art Sensors Technology in Spain 2013, this paper also reviews the most important flatness sensors designed and developed for the steelmaking industry in Spain.

  18. On-Line Flatness Measurement in the Steelmaking Industry

    Science.gov (United States)

    Molleda, Julio; Usamentiaga, Rubén; Garcίa, Daniel F.

    2013-01-01

    Shape is a key characteristic to determine the quality of outgoing flat-rolled products in the steel industry. It is greatly influenced by flatness, a feature to describe how the surface of a rolled product approaches a plane. Flatness is of the utmost importance in steelmaking, since it is used by most downstream processes and customers for the acceptance or rejection of rolled products. Flatness sensors compute flatness measurements based on comparing the length of several longitudinal fibers of the surface of the product under inspection. Two main different approaches are commonly used. On the one hand, most mechanical sensors measure the tensile stress across the width of the rolled product, while manufacturing and estimating the fiber lengths from this stress. On the other hand, optical sensors measure the length of the fibers by means of light patterns projected onto the product surface. In this paper, we review the techniques and the main sensors used in the steelmaking industry to measure and quantify flatness defects in steel plates, sheets and strips. Most of these techniques and sensors can be used in other industries involving rolling mills or continuous production lines, such as aluminum, copper and paper, to name a few. Encompassed in the special issue, State-of-the-Art Sensors Technology in Spain 2013, this paper also reviews the most important flatness sensors designed and developed for the steelmaking industry in Spain. PMID:23939583

  19. Observations of ebb flows on tidal flats: Evidence of dewatering?

    Science.gov (United States)

    Rinehimer, J. P.; Thomson, J. M.; Chickadel, C.

    2010-12-01

    Incised channels are a common morphological feature of tidal flats. When the flats are inundated, flows are generally forced by the tidally varying sea surface height. During low tide, however, these channels continue to drain throughout flat exposure even without an upstream source of water. While the role of porewater is generally overlooked due to the low permeability of marine muds, it remains the only potential source of flows through the channels during low tide. In situ and remotely sensed observations (Figure 1) at an incised channel on a tidal flat in Willapa Bay from Spring 2010 indicate that dewatering of the flats may be driving these low tide flows. High resolution Aquadopp ADCP velocity profiles are combined with observations from tower-based infrared (IR) video to produce a complete time series of surface velocity measurements throughout low tide. The IR video observations provide a measurement of surface currents even when the channel depth is below the blanking distance of the ADCP (10 cm). As the depth within the channel drops from 50 cm to 10 cm surface velocities increase from 10 cm/s to 60 cm/s even as the tide level drops below the channel flanks and the flats are dry. As the drainage continues, the temperature of the flow rises throughout low tide, mirroring temperatures within the sediment bed on the tidal flat. Drainage salinity falls despite the lack of any freshwater input to the flat indicating that less saline porewater may be the source. The likely source of the drainage water is from the channel flanks where time-lapse video shows slumping and compaction of channel sediments. Velocity profiles, in situ temperatures, and IR observations also are consistent with the presence of fluid muds and a hyperpycnal, density driven outflow at the channel mouth highlighting a possible pathway for sediment delivery from the flats to the main distributary channels of the bay. Figure 1: Time series of tidal flat channel velocities and temperatures

  20. A New Triangular Flat Shell Element With Drilling Rotations

    DEFF Research Database (Denmark)

    Damkilde, Lars

    2008-01-01

    A new flat triangular shell element has been developed based on a newly developed triangular plate bending element by the author and a new triangular membrane element with drilling degrees of freedom. The advantage of the drilling degree of freedom is that no special precautions have to be made...... in connecting with assembly of elements. Due to the drilling rotations all nodal degrees of freedom have stiffness, and therefore no artificial suppression of degrees of freedom are needed for flat or almost flat parts of the shell structure....

  1. Flat directions in left-right symmetric string derived models

    International Nuclear Information System (INIS)

    Cleaver, Gerald B.; Clements, David J.; Faraggi, Alon E.

    2002-01-01

    The only string models known to reproduce the minimal supersymmetric standard model in the low energy effective field theory are those constructed in the free fermionic formulation. We demonstrate the existence of quasirealistic free fermionic heterotic string models in which supersymmetric singlet flat directions do not exist. This raises the possibility that supersymmetry is broken perturbatively in such models by the one-loop Fayet-Iliopoulos term. We show, however, that supersymmetric flat directions that utilize vacuum expectation values of some non-Abelian fields in the massless string spectrum do exist in the model. We argue that hidden sector condensates lift the flat directions and break supersymmetry hierarchically

  2. On maximal surfaces in asymptotically flat space-times

    International Nuclear Information System (INIS)

    Bartnik, R.; Chrusciel, P.T.; O Murchadha, N.

    1990-01-01

    Existence of maximal and 'almost maximal' hypersurfaces in asymptotically flat space-times is established under boundary conditions weaker than those considered previously. We show in particular that every vacuum evolution of asymptotically flat data for Einstein equations can be foliated by slices maximal outside a spatially compact set and that every (strictly) stationary asymptotically flat space-time can be foliated by maximal hypersurfaces. Amongst other uniqueness results, we show that maximal hypersurface can be used to 'partially fix' an asymptotic Poincare group. (orig.)

  3. Loop quantum gravity in asymptotically flat spaces

    International Nuclear Information System (INIS)

    Arnsdorf, M.

    2000-01-01

    This thesis describes applications and extensions of the loop variable approach to non-perturbative quantum gravity. The common theme of the work presented, is the need to generalise loop quantum gravity to be applicable in cases where space is asymptotically flat, and no longer compact as is usually assumed. This is important for the study of isolated gravitational systems. It also presents a natural context in which to search for the semi-classical limit, one of the main outstanding problems in loop quantum gravity. In the first part of the thesis we study how isolated gravitational systems can be attributed particle-like properties. In particular, we show how spinorial states can arise in pure loop quantum gravity if spatial topology is non-trivial, thus confirming an old conjecture of Friedman and Sorkin. Heuristically, this corresponds to the idea that we can rotate isolated regions of spatial topology relative to the environment at infinity, and that only a 4π-rotation will take us back to the original configuration. To do this we extend the standard loop quantum gravity formalism by introducing a compactification of our non-compact spatial manifold, and study the knotting of embedded graphs. The second part of the thesis takes a more systematic approach to the study of loop quantum gravity on non-compact spaces. We look for new representations of the loop algebra, which give rise to quantum theories that are inequivalent to the standard one. These theories naturally describe excitations of a fiducial background state, which is specified via the choice of its vacuum expectation values. In particular, we can choose background states that describe the geometries of non-compact manifolds. We also discuss how suitable background states can be constructed that can approximate classical phase space data, in our case holonomies along embedded paths and geometrical quantities related to areas and volumes. These states extend the notion of the weave and provide a

  4. Software Simulates Sight: Flat Panel Mura Detection

    Science.gov (United States)

    2008-01-01

    In the increasingly sophisticated world of high-definition flat screen monitors and television screens, image clarity and the elimination of distortion are paramount concerns. As the devices that reproduce images become more and more sophisticated, so do the technologies that verify their accuracy. By simulating the manner in which a human eye perceives and interprets a visual stimulus, NASA scientists have found ways to automatically and accurately test new monitors and displays. The Spatial Standard Observer (SSO) software metric, developed by Dr. Andrew B. Watson at Ames Research Center, measures visibility and defects in screens, displays, and interfaces. In the design of such a software tool, a central challenge is determining which aspects of visual function to include while accuracy and generality are important, relative simplicity of the software module is also a key virtue. Based on data collected in ModelFest, a large cooperative multi-lab project hosted by the Optical Society of America, the SSO simulates a simplified model of human spatial vision, operating on a pair of images that are viewed at a specific viewing distance with pixels having a known relation to luminance. The SSO measures the visibility of foveal spatial patterns, or the discriminability of two patterns, by incorporating only a few essential components of vision. These components include local contrast transformation, a contrast sensitivity function, local masking, and local pooling. By this construction, the SSO provides output in units of "just noticeable differences" (JND) a unit of measure based on the assumed smallest difference of sensory input detectable by a human being. Herein is the truly amazing ability of the SSO, while conventional methods can manipulate images, the SSO models human perception. This set of equations actually defines a mathematical way of working with an image that accurately reflects the way in which the human eye and mind behold a stimulus. The SSO is

  5. The rocky flats controversy on radionuclide soil action levels

    International Nuclear Information System (INIS)

    Earle, T.C.

    2004-01-01

    This report describes how stakeholder involvement processes led to the successful resolution of a dispute over radionuclide soil action levels at the Rocky Flats Site near Denver, Colorado. During the Cold War Era, Rocky Flats, a plutonium fabrication plant, was part of the American government's multi-site nuclear weapons production facilities. Although the Rocky Flats plant had significant positive effects on the local economy, it became a target of public protest due to concerns over both public safety in the area surrounding the site and global nuclear proliferation. In the late 1980's, local safety concerns led to investigations by state and federal agencies. In 1992, with the Cold War ended, the Department of Energy decided to decommission the Rocky Flats site and to begin the long process of decontamination. (author)

  6. Unitarity in three-dimensional flat space higher spin theories

    International Nuclear Information System (INIS)

    Grumiller, D.; Riegler, M.; Rosseel, J.

    2014-01-01

    We investigate generic flat-space higher spin theories in three dimensions and find a no-go result, given certain assumptions that we spell out. Namely, it is only possible to have at most two out of the following three properties: unitarity, flat space, non-trivial higher spin states. Interestingly, unitarity provides an (algebra-dependent) upper bound on the central charge, like c=42 for the Galilean W_4"("2"−"1"−"1") algebra. We extend this no-go result to rule out unitary “multi-graviton” theories in flat space. We also provide an example circumventing the no-go result: Vasiliev-type flat space higher spin theory based on hs(1) can be unitary and simultaneously allow for non-trivial higher-spin states in the dual field theory.

  7. Northern Mariana Islands Marine Monitoring Team Reef Flat Surveys

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Commonwealth of the Northern Mariana Islands' (CNMI) interagency marine monitoring team conducts surveys on reef flat areas on the islands of Saipan, Tinian and...

  8. CFD simulation of estimating critical shear stress for cleaning flat ...

    Indian Academy of Sciences (India)

    Sumit Kawale

    2017-11-22

    Nov 22, 2017 ... Jet impingement; wall shear stress; cleaning of flat plate; turbulence model; critical shear stress; ... On comparing the theoretical predictions with wall shear ... distance and Reynolds number on peak value of local shear stress ...

  9. Measuring and modeling exposure from environmental radiation on tidal flats

    International Nuclear Information System (INIS)

    Gould, T.J.; Hess, C.T.

    2005-01-01

    To examine the shielding effects of the tide cycle, a high pressure ion chamber was used to measure the exposure rate from environmental radiation on tidal flats. A theoretical model is derived to predict the behavior of exposure rate as a function of time for a detector placed one meter above ground on a tidal flat. The numerical integration involved in this derivation results in an empirical formula which implies exposure rate ∝tan-1(sint). We propose that calculating the total exposure incurred on a tidal flat requires measurements of only the slope of the tidal flat and the exposure rate when no shielding occurs. Experimental results are consistent with the model

  10. Theoretical study of a flat eddy current probe

    International Nuclear Information System (INIS)

    Bouchard, A.; Dumont-Fillon, J.; Labbe, G.

    1976-01-01

    A mathematical model for the computation of the impedance of an eddy current probe has been determined in the case of flat product testing. Various applications are discussed with particular emphasis on ferromagnetic materials [fr

  11. Select PC/windows flat to develop data acquisition system

    International Nuclear Information System (INIS)

    Zhang Jin

    1993-01-01

    Through needing analysis, and also, considering user's ability of payment, the characteristic of China computer market, the computer developing tending, and the system's compatibility and up grade capability, PC/Windows flat are selected to develop a data acquisition system

  12. Array elements for a DBS flat-plate antenna

    Science.gov (United States)

    Maddocks, M. C. D.

    1988-07-01

    The introduction of a direct broadcast by satellite (DBS) television service requires suitable receiving antennas to be available. An alternative to the parabolic dish antenna is a flat-plate antenna. The overall design of a circularly-polarized flat-plate antenna which can be mounted flat on the wall of a building has been considered in a companion Report. In this Report various types of elements are investigated and their advantages and disadvantages discussed. The most suitable element for use in a flat-plate array is identified as a linearly-polarized folded-dipole element; its performance is reported here. Linearly-polarized elements are found to perform better than circularly-polarized elements and could be used with a polarization converter to receive the circularly-polarized radiation that would be transmitted by DBS.

  13. Svendsen Symphony No. 2 in B flat / Robert Layton

    Index Scriptorium Estoniae

    Layton, Robert

    1994-01-01

    Uuest heliplaadist "Svendsen Symphony No. 2 in B flat, Op. 15... Stavanger Symphony Orchestra / Grant Llewellyn. Chatsworth CD FCM 1002; Symphony No. 2 - selected comparisons: Gothenburg SO, Järvi (11/87)(BIS) CD 347

  14. Benchmarking and performance improvement at Rocky Flats Technology Site

    International Nuclear Information System (INIS)

    Elliott, C.; Doyle, G.; Featherman, W.L.

    1997-03-01

    The Rocky Flats Environmental Technology Site has initiated a major work process improvement campaign using the tools of formalized benchmarking and streamlining. This paper provides insights into some of the process improvement activities performed at Rocky Flats from November 1995 through December 1996. It reviews the background, motivation, methodology, results, and lessons learned from this ongoing effort. The paper also presents important gains realized through process analysis and improvement including significant cost savings, productivity improvements, and an enhanced understanding of site work processes

  15. A flat spectral Faraday filter for sodium lidar.

    Science.gov (United States)

    Yang, Yong; Cheng, Xuewu; Li, Faquan; Hu, Xiong; Lin, Xin; Gong, Shunsheng

    2011-04-01

    We report a flat spectral Faraday anomalous dispersion optical filter (FS-FADOF) for sodium lidar. The physical and technical considerations for obtaining a FS-FADOF with a 3.5 GHz flat spectral transmission function are presented. It was found that the effective transmission of this filter was much higher (>94%) and more uniform than that of the ultranarrowband FADOF, and therefore were less sensitive to laser-frequency drift. Thus, the FS-FADOF can improve lidar efficiency and precision.

  16. Flat beams in a 50 TeV hadron collider

    International Nuclear Information System (INIS)

    Peggs, S.; Harrison, M.; Pilat, F.; Syphers, M.

    1997-01-01

    The basic beam dynamics of a next generation 50 x 50 TeV hadron collider based on a high field magnet approach have been outlined over the past several years. Radiation damping not only produces small emittances, but also flat beams, just as in electron machines. Based on open-quotes Snowmass 96close quotes parameters, we investigate the issues associated with flat beams in very high energy hadron colliders

  17. Thermal-hydraulic characteristics of double flat core HCLWR

    International Nuclear Information System (INIS)

    Sugimoto, Jun; Iwamura, Takamichi; Okubo, Tsutomu; Murao, Yoshio

    1989-02-01

    A thermal-hydraulic characteristics of double flat core high conversion light water reactor (HCLWR) is described. The concept of flat core proposed by Ishiguro et al. is to achieve negative void reactivity coefficient in tight lattice core, and at the same time, high conversion ratio and high burnup can be obtainable. The proposed double flat core HCLWR, based on these physical advantages and the consideration of safety assurance, aims at efficient use of the pressure vessel space to produce comparable thermal output as current 3-loop PWRs. The present work revealed the following items concerning the thermalhydraulic feasibility of the double flat core HCLWR: (1) Main thermal-hydraulic parameters of the plant can be almost the same as current PWRs, showing the use of PWR standard components without major modifications except in core region. (2) Heat removal from the fuel rod in a steady operational condition has enough margin to the critical heat flux (CHF) limit, which is evaluated with the existing CHF correlations. (3) The calculation by REFLA code shows that the maximum cladding temperature in LOCA-reflood is estimated to be far lower than the licensing criteria. It is therefore considered that the proposed double flat core HCLWR is feasible from the point of thermal-hydraulics. Since the available data base has certain applicational limit to the very short core as the present double flat core HCLWR, further detailed assessment is required. (author)

  18. Flat-panel detectors in x-ray diagnosis

    International Nuclear Information System (INIS)

    Spahn, M.; Heer, V.; Freytag, R.

    2003-01-01

    For all application segments X-ray systems with flat-panel detectors increasingly enter the market. In digital radiography, mammography and cardiologic angiography flat-panel detectors are already well established while they are made ready for market introduction in general angiography and fluoroscopy. Two flat-panel detector technologies are available. One technology is based on an indirect conversion process of X-rays while the other one uses a direct conversion method.For radiography and dynamic applications the indirect method provides substantial advantages, while the direct method has some benefits for mammography. In radiography and mammography flat-panel detectors lead to clear improvements with respect to workflow, image quality and dose reduction potentials. These improvements are fostered by the immediate availability of the image, the large dynamic range and the high sensitivity to X-rays. New applications and the use of complex image processing algorithms have the potential to enlarge the present diagnostic range of applications.Up to now, image intensifiers are still the well-established technology for angiography and fluoroscopy. Nevertheless flat-panel detectors begin to enter this field, especially in cardiologic angiography.Characteristics of flat-panel detectors such as the availability of distortion-free images, the excellent contrast resolution, the large dynamic range, the high sensitivity to X-rays and the usability in magnetic fields provide the basis for improved and new diagnostic and interventional methods. (orig.) [de

  19. New edge-centered photonic square lattices with flat bands

    Science.gov (United States)

    Zhang, Da; Zhang, Yiqi; Zhong, Hua; Li, Changbiao; Zhang, Zhaoyang; Zhang, Yanpeng; Belić, Milivoj R.

    2017-07-01

    We report a new class of edge-centered photonic square lattices with multiple flat bands, and consider in detail two examples: the Lieb-5 and Lieb-7 lattices. In these lattices, there are 5 and 7 sites in the unit cell and in general, the number is restricted to odd integers. The number of flat bands m in the new Lieb lattices is related to the number of sites N in the unit cell by a simple formula m =(N - 1) / 2. The flat bands reported here are independent of the pseudomagnetic field. The properties of lattices with even and odd number of flat bands are different. We consider the localization of light in such Lieb lattices. If the input beam excites the flat-band mode, it will not diffract during propagation, owing to the strong mode localization. In the Lieb-7 lattice, the beam will also oscillate during propagation and still not diffract. The period of oscillation is determined by the energy difference between the two flat bands. This study provides a new platform for investigating light trapping, photonic topological insulators, and pseudospin-mediated vortex generation.

  20. THE FLAT TAX - A COMPARATIVE STUDY OF THE EXISTING MODELS

    Directory of Open Access Journals (Sweden)

    Schiau (Macavei Laura - Liana

    2011-07-01

    Full Text Available In the two last decades the flat tax systems have spread all around the globe from East and Central Europe to Asia and Central America. Many specialists consider this phenomenon a real fiscal revolution, but others see it as a mistake as long as the new systems are just a feint of the true flat tax designed by the famous Stanford University professors Robert Hall and Alvin Rabushka. In this context this paper tries to determine which of the existing flat tax systems resemble the true flat tax model by comparing and contrasting their main characteristics with the features of the model proposed by Hall and Rabushka. The research also underlines the common features and the differences between the existing models. The idea of this kind of study is not really new, others have done it but the comparison was limited to one country. For example Emil Kalchev from New Bulgarian University has asses the Bulgarian income system, by comparing it with the flat tax and concluding that taxation in Bulgaria is not simple, neutral and non-distortive. Our research is based on several case studies and on compare and contrast qualitative and quantitative methods. The study starts form the fiscal design drawn by the two American professors in the book The Flat Tax. Four main characteristics of the flat tax system were chosen in order to build the comparison: fiscal design, simplicity, avoidance of double taxation and uniformity of the tax rates. The jurisdictions chosen for the case study are countries all around the globe with fiscal systems which are considered flat tax systems. The results obtained show that the fiscal design of Hong Kong is the only flat tax model which is built following an economic logic and not a legal sense, being in the same time a simple and transparent system. Others countries as Slovakia, Albania, Macedonia in Central and Eastern Europe fulfill the requirement regarding the uniformity of taxation. Other jurisdictions avoid the double

  1. Dynamics of intertidal flats in the Loire estuary

    Science.gov (United States)

    Kervella, Stephane; Sottolichio, Aldo; Bertier, Christine

    2014-05-01

    Tidal flats form at the edges of many tidal estuaries, and are found in broad climatic regions. Their evolution plays a fundamental role in maintaining the morphodynamic equilibrium of an estuary. The Loire estuary is one of the largest macrotidal systems of the french atlantic coast. Since 200 years, its geometry has been drastically modified through channeling, deepening, embanking, infilling of secondary channels, etc. These works altered many intertidal areas. In the recent years, efforts for the rectification of the morphology have been made in order to restore the ecology of the estuary. In this context, it is crucial to better understand the dynamics of intertidal flats, still poorly understood in this estuary. The aim of this work is to analyse a series of original observations conducted for the first time in two intertidal flats of the central Lore estuary between 2008 and 2010. The tidal flats are situated in the northern bank, at 12 and 17 km upstream from the mouth respectively. Six Altus altimeters were deployed at two cross shore transects, measuring continuously and at a high-frequency bed altimetry and water level, providing information on tide and waves. At the semi-diurnal tidal scale, the surficial sediment of intertidal flats is permanently mobilized. Altimetry variations are low, and their amplitude varies as a function of tides and river flow. At the scale of several months, the sedimentation is controlled by the position of the turbidity maximum (and therefore by the river flow) and also by the tidal amplitude. During low river flow periods, altimetry variations are only due to tidal cycles. During decaying tides, suspended sediment settle mainly on the lower part of the tidal flats, forming fluid mud layers of several cm thick, which can consolidate rapidly; under rising tides, the increasing of tidal currents promotes erosion. During periods of high river flow, the turbidity maximum shifts to the lower estuary. The higher suspended sediment

  2. Flexible flat feet in children: a real problem?

    Science.gov (United States)

    García-Rodríguez, A; Martín-Jiménez, F; Carnero-Varo, M; Gómez-Gracia, E; Gómez-Aracena, J; Fernández-Crehuet, J

    1999-06-01

    To estimate the prevalence of flexible flat feet in the provincial population of 4- to 13-year-old schoolchildren and the incidence of treatments considered unnecessary. Province of Málaga, Spain. We examined and graded by severity a sample of 1181 pupils taken from a total population of 198 858 primary schoolchildren (CI: 95%; margin of error: 5%). The sample group was separated into three 2-year age groups: 4 and 5 years, 8 and 9 years, and 12 and 13 years. The plantar footprint was classified according to Denis1 into three grades of flat feet: grade 1 in which support of the lateral edge of the foot is half that of the metatarsal support; grade 2 in which the support of the central zone and forefoot are equal; and grade 3 in which the support in the central zone of the foot is greater than the width of the metatarsal support. The statistical analysis for the evaluation of the differences between the groups was performed with Student's t and chi2 tests as appropriate. The prevalence of flat feet was 2.7%. Of the 1181 children sampled, 168 children (14.2%) were receiving orthopedic treatment, but only 2.7% had diagnostic criteria of flat feet. When we inspected the sample, we found that a number of children were being treated for flat feet with boots and arch supports. Most of them did not have a flat plantar footprint according to the criteria that we used for this work. Furthermore, in the group of children that we diagnosed as having flat feet, only 28.1% were being treated. We found no significant differences between the number of children receiving orthopedic treatments and the presence or absence of a flat plantar footprint. Children who were overweight in the 4- and 5-year-old group showed an increased prevalence for flat feet as diagnosed by us. The data suggest that an excessive number of orthopedic treatments had been prescribed in the province. When extrapolated to the 1997 population of schoolchildren within the age groups studied the figures

  3. Relationship between flexible flat foot and developmental hip dysplasia.

    Science.gov (United States)

    Ponce de León Samper, M C; Herrera Ortiz, G; Castellanos Mendoza, C

    2015-01-01

    To evaluate the possible relationship between flexible flat foot and developmental hip dysplasia in children between six and 15 years of age. Cross-sectional study including 65 patients that had undergone surgery due to residual hip dysplasia or hip dislocation and compared against 75 healthy patients. Flexible flat foot prevalence was measured in each group, with the results showing that 61% of the group with residual hip dysplasia or hip dislocation had this condition, vs. 12% in the healthy group. The statistical analysis shows that the chances of suffering from flexible flat foot, are five times greater in the hip dysplasia or hip dislocation group, than in the healthy group. There is no evidence in the literature showing a relationship between these two conditions, even though they have a common etiology. This study shows a potential measurable relation between this two conditions. Patients with hip dysplasia or dislocation may have a higher chance of presenting flexible flat foot during late childhood, adolescence and adulthood, a fact that suggests a relationship between these two pathologies. Also, patients who seek assistance for the first time because of a flexible flat foot condition without having been evaluated during the first year of life for hip dysplasia, would be better off if evaluated for residual hip dysplasia. Copyright © 2014 SECOT. Published by Elsevier Espana. All rights reserved.

  4. ACS/WFC Sky Flats from Frontier Fields Imaging

    Science.gov (United States)

    Mack, J.; Lucas, R. A.; Grogin, N. A.; Bohlin, R. C.; Koekemoer, A. M.

    2018-04-01

    Parallel imaging data from the HST Frontier Fields campaign (Lotz et al. 2017) have been used to compute sky flats for the ACS/WFC detector in order to verify the accuracy of the current set of flat field reference files. By masking sources and then co-adding many deep frames, the F606W and F814W filters have enough combined background signal that from Poisson statistics are efficiency tracks the thickness of the two WFC chips. Observations of blue and red calibration standards measured at various positions on the detector (Bohlin et al. 2017) confirm the fidelity of the F814W flat, with aperture photometry consistent to 1% across the FOV, regardless of spectral type. At bluer wavelengths, the total sky background is substantially lower, and the F435W sky flat shows a combination of both flat errors and detector artifacts. Aperture photometry of the red standard star shows a maximum deviation of 1.4% across the array in this filter. Larger residuals up to 2.5% are found for the blue standard, suggesting that the spatial sensitivity in F435W depends on spectral type.

  5. Experimental and theoretical investigation of column - flat slab joint ductility

    International Nuclear Information System (INIS)

    Iskhakov, I.; Ribakov, Y.; Shah, A.

    2009-01-01

    Most modern seismic codes use ductility as one of the basic design parameters. Actually, ductility defines the ability of a structure or its elements to absorb energy by plastic deformations. Until the end of the previous century ductility was defined qualitatively. Most research works related to ductility are focused on structural elements' sections. This study was aimed at complex experimental and theoretical investigation of flat slab-column joints ductility. It is one of the first attempts to obtain quantitative values of joint's ductility for the case of high strength concrete columns and normal strength concrete slabs. It was shown that the flat slab-column joint is a three-dimension (3D) element and its ductility in horizontal and vertical directions are different. This is the main difference between ductility of elements and joint ductility. In case of flat slab-column joints, essential contribution to joint's ductility can be obtained due to the slab's confining effect. Based on experimental data, the authors demonstrate that flat slab-column joint's ductility depends on the joint's confining effect in two horizontal and vertical directions. Furthermore, the influence of slab load intensity and slab reinforcement ratio on the joint's ductility is performed in this study. It is also demonstrated that the effect of the ratio between the slab thickness and the column's section dimension on the ductility parameter is significant. Equations for obtaining a quantitative value of a flat slab-column joint's ductility parameter were developed.

  6. Mussel beds are biological power stations on intertidal flats

    Science.gov (United States)

    Engel, Friederike G.; Alegria, Javier; Andriana, Rosyta; Donadi, Serena; Gusmao, Joao B.; van Leeuwe, Maria A.; Matthiessen, Birte; Eriksson, Britas Klemens

    2017-05-01

    Intertidal flats are highly productive areas that support large numbers of invertebrates, fish, and birds. Benthic diatoms are essential for the function of tidal flats. They fuel the benthic food web by forming a thin photosynthesizing compartment in the top-layer of the sediment that stretches over the vast sediment flats during low tide. However, the abundance and function of the diatom film is not homogenously distributed. Recently, we have realized the importance of bivalve reefs for structuring intertidal ecosystems; by creating structures on the intertidal flats they provide habitat, reduce hydrodynamic stress and modify the surrounding sediment conditions, which promote the abundance of associated organisms. Accordingly, field studies show that high chlorophyll a concentration in the sediment co-vary with the presence of mussel beds. Here we present conclusive evidence by a manipulative experiment that mussels increase the local biomass of benthic microalgae; and relate this to increasing biomass of microalgae as well as productivity of the biofilm across a nearby mussel bed. Our results show that the ecosystem engineering properties of mussel beds transform them into hot spots for primary production on tidal flats, highlighting the importance of biological control of sedimentary systems.

  7. Evaluation of the deformation value of an optical flat under gravity

    International Nuclear Information System (INIS)

    Kondo, Yohan; Bitou, Youichi

    2014-01-01

    The flatness of an optical surface can be evaluated using a Fizeau interferometer. There is strong demand for ensuring that the measurement uncertainty of flatness is of nanometer order over a measurement range of 300 mm or more; however, the measurement range and measurement uncertainty of flatness at the National Metrology Institute of Japan (NMIJ) are 300 mm and 10 nm, respectively. In a Fizeau flatness interferometer, the gap distance between the reference flat and the specimen is measured. To obtain the absolute profile of the specimen, the absolute profile of the reference flat should be measured in advance. The three-flat test is one of the methods used to measure the absolute profile of a reference flat. The reference flat, however, deforms under the force of gravity, and its absolute deformation value cannot be determined by the three-flat test. The deformation value of the reference flat can be corrected by the finite element method (FEM) analysis; however, it is difficult to ensure the validity of the analysis and there is a large uncertainty component of the Fizeau flatness interferometer. To verify the FEM analysis, we developed a scanning deflectometric profiler (SDP) that does not require a reference flat and can directly measure a profile. We calibrated an optical flat using a Fizeau flatness interferometer and the SDP. Finally, the deformation value of the reference flat under the force of gravity was evaluated by comparing the measurement results. (paper)

  8. Higher-spin flat space cosmologies with soft hair

    Energy Technology Data Exchange (ETDEWEB)

    Ammon, Martin [Theoretisch-Physikalisches Institut, Friedrich-Schiller University of Jena, Max-Wien-Platz 1, D-07743 Jena (Germany); Grumiller, Daniel [Institute for Theoretical Physics, TU Wien, Wiedner Hauptstrasse 8-10/136, A-1040 Vienna (Austria); CMCC-Universidade Federal do ABC,Santo André, S.P. (Brazil); Prohazka, Stefan [Institute for Theoretical Physics, TU Wien, Wiedner Hauptstrasse 8-10/136, A-1040 Vienna (Austria); Riegler, Max [Université libre de Bruxelles, Boulevard du Triomphe, Campus de la Plaine,1050 Bruxelles (Belgium); Wutte, Raphaela [Institute for Theoretical Physics, TU Wien, Wiedner Hauptstrasse 8-10/136, A-1040 Vienna (Austria)

    2017-05-08

    We present and discuss near horizon boundary conditions for flat space higher-spin gravity in three dimensions. As in related work our boundary conditions ensure regularity of the solutions independently of the charges. The asymptotic symmetry algebra is given by a set of û(1) current algebras. The associated charges generate higher-spin soft hair. We derive the entropy for solutions that are continuously connected to flat space cosmologies and find the same result as in the spin-2 case: the entropy is linear in the spin-2 zero-mode charges and independent from the spin-3 charges. Using twisted Sugawara-like constructions of higher-spin currents we show that our simple result for entropy of higher-spin flat space cosmologies coincides precisely with the complicated earlier results expressed in terms of higher-spin zero mode charges.

  9. Disruption effects from the collision of quasi-flat beams

    International Nuclear Information System (INIS)

    Chen, Pisin.

    1993-04-01

    The disruption effects from the collision of round beams and flat beams in linear colliders have been studied in the past, and has by now been well understood. In practice, however, in the current SLC running condition and in several designs of the next generation linear colliders, the quasi-flat beam geometries are expected. Namely, the beam aspect ratio R ≡ σ x /σ y > 1, but not infinitely large. In this regime the disruption effects in both x and y dimensions should be carefully included in order to properly describe the beam-beam interaction phenomena. In this paper we investigate two major disruption effects for the quasi-flat beam regime: The luminosity enhancement factor and the effective beamstrahlung. Computer simulations are employed and simple scaling laws are deduced

  10. Projective flatness in the quantisation of bosons and fermions

    Science.gov (United States)

    Wu, Siye

    2015-07-01

    We compare the quantisation of linear systems of bosons and fermions. We recall the appearance of projectively flat connection and results on parallel transport in the quantisation of bosons. We then discuss pre-quantisation and quantisation of fermions using the calculus of fermionic variables. We define a natural connection on the bundle of Hilbert spaces and show that it is projectively flat. This identifies, up to a phase, equivalent spinor representations constructed by various polarisations. We introduce the concept of metaplectic correction for fermions and show that the bundle of corrected Hilbert spaces is naturally flat. We then show that the parallel transport in the bundle of Hilbert spaces along a geodesic is a rescaled projection provided that the geodesic lies within the complement of a cut locus. Finally, we study the bundle of Hilbert spaces when there is a symmetry.

  11. The rocky flats controversy on radionuclide soil action levels

    International Nuclear Information System (INIS)

    Earle, T.C.

    2004-01-01

    This report describes the Rocky Flats radionuclide soil action level controversy as a case study for the purpose of understanding the nature and value of stakeholder involvement in the management of radiological hazards. The report consists of three main sections. The first section outlines the Rocky Flats story, including the Cold War era, the post-Cold War era, and the transition between the two. This provides the context necessary to understand the radionuclide soil action level controversy, the main events of which are described in the second section. In the final section, the Rocky Flats case is briefly discussed within the framework of a general model of stakeholder involvement and the lessons learned from the case are identified. (author)

  12. Rigidity of complete noncompact bach-flat n-manifolds

    Science.gov (United States)

    Chu, Yawei; Feng, Pinghua

    2012-11-01

    Let (Mn,g) be a complete noncompact Bach-flat n-manifold with the positive Yamabe constant and constant scalar curvature. Assume that the L2-norm of the trace-free Riemannian curvature tensor R∘m is finite. In this paper, we prove that (Mn,g) is a constant curvature space if the L-norm of R∘m is sufficiently small. Moreover, we get a gap theorem for (Mn,g) with positive scalar curvature. This can be viewed as a generalization of our earlier results of 4-dimensional Bach-flat manifolds with constant scalar curvature R≥0 [Y.W. Chu, A rigidity theorem for complete noncompact Bach-flat manifolds, J. Geom. Phys. 61 (2011) 516-521]. Furthermore, when n>9, we derive a rigidity result for R<0.

  13. Weyl-Euler-Lagrange Equations of Motion on Flat Manifold

    Directory of Open Access Journals (Sweden)

    Zeki Kasap

    2015-01-01

    Full Text Available This paper deals with Weyl-Euler-Lagrange equations of motion on flat manifold. It is well known that a Riemannian manifold is said to be flat if its curvature is everywhere zero. Furthermore, a flat manifold is one Euclidean space in terms of distances. Weyl introduced a metric with a conformal transformation for unified theory in 1918. Classical mechanics is one of the major subfields of mechanics. Also, one way of solving problems in classical mechanics occurs with the help of the Euler-Lagrange equations. In this study, partial differential equations have been obtained for movement of objects in space and solutions of these equations have been generated by using the symbolic Algebra software. Additionally, the improvements, obtained in this study, will be presented.

  14. On beam quality and flatness of radiotherapy megavoltage photon beams

    International Nuclear Information System (INIS)

    Hossain, Murshed; Rhoades, Jeffrey

    2016-01-01

    Ratio of percentage depth dose (PDD) at two depths, PDD at a depth of 10 cm (PDD 10 ), and beam flatness are monitored regularly for radiotherapy beams for quality assurance. The purpose of this study is to understand the effects of changes in one of these parameters on the other. Is it possible to monitor only the beam flatness and not PDD? The investigation has two components. Naturally occurring i.e., unintended changes in PDD ratio and in-plane flatness for 6 and 10 MV photon beams for one particular Siemens Artiste Linac are monitored for a period of about 4 years. Secondly, deliberate changes in the beam parameters are induced by changing the bending magnet current (BMI). Relationships between various beam parameters for unintended changes as well as deliberate changes are characterized. Long term unintentional changes of PDD ratio are found to have no systematic trend. The flatness in the in plane direction for 6 and 10 MV beams show slow increase of 0.43 and 0.75 % respectively in about 4 years while the changes in the PDD ratio show no such trend. Over 10 % changes in BMI are required to induce changes in the beam quality indices at 2 % level. PDD ratio for the 10 MV beam is found to be less sensitive, while the depth of maximum dose, d max , is more sensitive to the changes in BMI compared to the 6 MV beam. Tolerances are more stringent for PDD 10 than PDD ratio for the 10 MV beam. PDD ratio, PDD 10 , and flatness must be monitored independently. Furthermore, off axis ratio alone cannot be used to monitor flatness. The effect of beam quality change in the absolute dose is clinically insignificant.

  15. Movement Features Which Describe the Flat Bench Press

    Directory of Open Access Journals (Sweden)

    Król Henryk

    2017-06-01

    Full Text Available Introduction. In sport technique studies, motion features can be useful as they have a certain defined measure [1]. In this work, we examined the following three features: the structure of the movement (all the characteristics of the movement, the fluency of the movement, and the rhythm of the movement. The aim of the study was to determine the usefulness of the selected movement features in the evaluation of the flat bench press. The protocol of the study included a flat bench press with free weights and a “touch-and-go” technique. Material and methods. The study involved twenty healthy men; however, only two were selected for analysis. The first subject was a 25-year-old powerlifter (body mass = 95 kg; body height = 182 cm; 1-RM in flat bench press = 145 kg. The second one was a 25-year-old bodybuilder (body mass = 77 kg; body height = 175 cm; 1-RM in flat bench press = 100 kg. The subjects performed consecutive sets of a single repetition of flat bench pressing with an increasing load (70, 80, 90, and 100% 1-RM, with the anticipated maximum weight, until the completion of one repetition maximum. Multidimensional movement analysis was made with the measuring system Smart-E (BTS, Italy, which consisted of six infrared cameras (120 Hz and a wireless module to measure muscle bioelectric activity (Pocket EMG. Results. It was demonstrated that the internal structure of the bench press performed by the bodybuilder and the powerlifter was different. As the time-history of barbell kinematics (the acceleration-time curve showed, with increased loading of the barbell, the rhythm of the flat bench press changed, and the fluidity of the movement worsened.

  16. Blackbody radiation from light cone in flat space time

    International Nuclear Information System (INIS)

    Gerlach, U.H.

    1983-01-01

    Blackbody radiation in flat space-time is not necessarily associated with the flat event horizon of a single accelerated observer. The author considers a spherical bubble which expands in a uniformly accelerating fashion. Its history traces out a time-like hyperboloid. Suppose the bubble membrane has a spatially isotropic and homogeneous (surface) stress energy tensor i.e. the membrane is made out of the stiffest possible material permitted by causality considerations. It follows that this bubble membrane is in equilibrium even though it is expanding. Such an expanding bubble membrane may serve as a detector of electromagnetic radiation if the membrane can interact with the electromagnetic field. (Auth.)

  17. The removal of plutonium contaminants from Rocky Flats Plant soil

    International Nuclear Information System (INIS)

    Sunderland, N.R.

    1987-01-01

    This research was undertaken to determine if the TRUclean process could effectively remove radioactive elements from soils other than derived coral. This is an interim report prior to the project report and discusses the outcome of the tests of the Rocky Flats Plant (RFP) soil. The soil tested contained plutonium particulates in the micron and submicron range. Volume reduction and activity removal were accomplished with an overall efficiency of greater than 90%. The TRUclean process is a very practical and economical solution to soil contamination problems at the Rocky Flats Plant

  18. Development of Surfaces Optically Suitable for Flat Solar Panels

    Science.gov (United States)

    Desmet, D.; Jason, A.

    1978-01-01

    Three areas of research in the development of flat solar panels are described. (1) A reflectometer which can separately evaluate the spectral and diffuse reflectivities of surfaces was developed. The reflectometer has a phase locked detection system. (2) A coating composed of strongly bound copper oxide that is formed by an etching process performed on an aluminum alloy with high copper content was also developed. Because of this one step fabrication process, fabrication costs are expected to be small. (3) A literature search was conducted and conclusions on the required optical properties of flat plate solar collectors are presented.

  19. "Flat-Fish" vacuum chamber for the ISR

    CERN Multimedia

    CERN PhotoLab

    1983-01-01

    The "Flat-Fish" vacuum chamber was a very special one for the ISR beam intersection I-4, inside the Split-Field Magnet. Technical descriptions are given with pictures 7802042 and 7712182. There were several generations of this chamber. This picture was taken during the last year of ISR operation. See also 7510230X, 7511123X, 7802039, 7802041. A flat-fish type vacuum chamber was also used at I-8, inside the Open Axial Field Magnet (OAFM, experiment 807 on large transverse momentum collision products), see 7901358.

  20. Feedforward Tracking Control of Flat Recurrent Fuzzy Systems

    International Nuclear Information System (INIS)

    Gering, Stefan; Adamy, Jürgen

    2014-01-01

    Flatness based feedforward control has proven to be a feasible solution for the problem of tracking control, which may be applied to a broad class of nonlinear systems. If a flat output of the system is known, the control is often based on a feedforward controller generating a nominal input in combination with a linear controller stabilizing the linearized error dynamics around the trajectory. We show in this paper that the very same idea may be incorporated for tracking control of MIMO recurrent fuzzy systems. Their dynamics is given by means of linguistic differential equations but may be converted into a hybrid system representation, which then serves as the basis for controller synthesis

  1. Flat rotation curves using scalar-tensor theories

    Energy Technology Data Exchange (ETDEWEB)

    Cervantes-Cota, Jorge L [Depto de Fisica, Instituto Nacional de Investigaciones Nucleares, A.P. 18-1027, 11801 D.F. (Mexico); RodrIguez-Meza, M A [Depto de Fisica, Instituto Nacional de Investigaciones Nucleares, A.P. 18-1027, 11801 D.F. (Mexico); Nunez, Dario [Instituto de Ciencias Nucleares, Universidad Nacional Autonoma de Mexico, A.P. 70-543, 04510 D.F. (Mexico)

    2007-11-15

    We computed flat rotation curves from scalar-tensor theories in their weak field limit. Our model, by construction, fits a flat rotation profile for velocities of stars. As a result, the form of the scalar field potential and DM distribution in a galaxy are determined. By taking into account the constraints for the fundamental parameters of the theory ({lambda}, {alpha}), it is possible to obtain analytical results for the density profiles. For positive and negative values of {alpha}, the DM matter profile is as cuspy as NFW's.

  2. A flat triangular shell element with Loof nodes

    DEFF Research Database (Denmark)

    Poulsen, Peter Noe; Damkilde, Lars

    1996-01-01

    In the formulation of flat shell elements it is difficult to achieve inter-element compatibility between membrane and transverse displacements for non-coplanar elements. Many elements lack proper nodal degrees of freedom to model intersections making the assembly of elements troublesome. A flat...... triangular shell element is established by a combination of a new plate bending element DKTL and the well-known linear membrane strain element LST, and for this element the above-mentioned deficiences are avoided. The plate bending element DKTL is based on Discrete Kirchhoff Theory and Loof nodes. The nodal...

  3. Interacting agegraphic dark energy models in non-flat universe

    International Nuclear Information System (INIS)

    Sheykhi, Ahmad

    2009-01-01

    A so-called 'agegraphic dark energy' was recently proposed to explain the dark energy-dominated universe. In this Letter, we generalize the agegraphic dark energy models to the universe with spatial curvature in the presence of interaction between dark matter and dark energy. We show that these models can accommodate w D =-1 crossing for the equation of state of dark energy. In the limiting case of a flat universe, i.e. k=0, all previous results of agegraphic dark energy in flat universe are restored.

  4. Color quality management in advanced flat panel display engines

    Science.gov (United States)

    Lebowsky, Fritz; Neugebauer, Charles F.; Marnatti, David M.

    2003-01-01

    During recent years color reproduction systems for consumer needs have experienced various difficulties. In particular, flat panels and printers could not reach a satisfactory color match. The RGB image stored on an Internet server of a retailer did not show the desired colors on a consumer display device or printer device. STMicroelectronics addresses this important color reproduction issue inside their advanced display engines using novel algorithms targeted for low cost consumer flat panels. Using a new and genuine RGB color space transformation, which combines a gamma correction Look-Up-Table, tetrahedrization, and linear interpolation, we satisfy market demands.

  5. Study of conformally flat polytropes with tilted congruence

    Science.gov (United States)

    Sharif, M.; Sadiq, Sobia

    This paper is aimed to study the modeling of spherically symmetric spacetime in the presence of anisotropic dissipative fluid configuration. This is accomplished for an observer moving relative to matter content using two cases of polytropic equation-of-state under conformally flat condition. We formulate the corresponding generalized Tolman-Oppenheimer-Volkoff equation, mass equation, as well as energy conditions for both cases. The conformally flat condition is imposed to find an expression for anisotropy which helps to study spherically symmetric polytropes. Finally, Tolman mass is used to analyze stability of the resulting models.

  6. Two theorems on flat space-time gravitational theories

    International Nuclear Information System (INIS)

    Castagnino, M.; Chimento, L.

    1980-01-01

    The first theorem states that all flat space-time gravitational theories must have a Lagrangian with a first term that is an homogeneous (degree-1) function of the 4-velocity usup(i), plus a functional of nsub(ij)usup(i)usup(j). The second theorem states that all gravitational theories that satisfy the strong equivalence principle have a Lagrangian with a first term gsub(ij)(x)usup(i)usup(j) plus an irrelevant term. In both cases the theories must issue from a unique variational principle. Therefore, under this condition it is impossible to find a flat space-time theory that satisfies the strong equivalence principle. (author)

  7. Prescribed curvature tensor in locally conformally flat manifolds

    Science.gov (United States)

    Pina, Romildo; Pieterzack, Mauricio

    2018-01-01

    A global existence theorem for the prescribed curvature tensor problem in locally conformally flat manifolds is proved for a special class of tensors R. Necessary and sufficient conditions for the existence of a metric g ¯ , conformal to Euclidean g, are determined such that R ¯ = R, where R ¯ is the Riemannian curvature tensor of the metric g ¯ . The solution to this problem is given explicitly for special cases of the tensor R, including the case where the metric g ¯ is complete on Rn. Similar problems are considered for locally conformally flat manifolds.

  8. Vacuum energy in asymptotically flat 2 + 1 gravity

    Energy Technology Data Exchange (ETDEWEB)

    Miskovic, Olivera, E-mail: olivera.miskovic@pucv.cl [Instituto de Física, Pontificia Universidad Católica de Valparaíso, Casilla 4059, Valparaíso (Chile); Olea, Rodrigo, E-mail: rodrigo.olea@unab.cl [Departamento de Ciencias Físicas, Universidad Andres Bello, Sazié 2212, Piso 7, Santiago (Chile); Roy, Debraj, E-mail: roy.debraj@pucv.cl [Instituto de Física, Pontificia Universidad Católica de Valparaíso, Casilla 4059, Valparaíso (Chile)

    2017-04-10

    We compute the vacuum energy of three-dimensional asymptotically flat space based on a Chern–Simons formulation for the Poincaré group. The equivalent action is nothing but the Einstein–Hilbert term in the bulk plus half of the Gibbons–Hawking term at the boundary. The derivation is based on the evaluation of the Noether charges in the vacuum. We obtain that the vacuum energy of this space has the same value as the one of the asymptotically flat limit of three-dimensional anti-de Sitter space.

  9. Vacuum energy in asymptotically flat 2 + 1 gravity

    International Nuclear Information System (INIS)

    Miskovic, Olivera; Olea, Rodrigo; Roy, Debraj

    2017-01-01

    We compute the vacuum energy of three-dimensional asymptotically flat space based on a Chern–Simons formulation for the Poincaré group. The equivalent action is nothing but the Einstein–Hilbert term in the bulk plus half of the Gibbons–Hawking term at the boundary. The derivation is based on the evaluation of the Noether charges in the vacuum. We obtain that the vacuum energy of this space has the same value as the one of the asymptotically flat limit of three-dimensional anti-de Sitter space.

  10. Stability of generic thin shells in conformally flat spacetimes

    Energy Technology Data Exchange (ETDEWEB)

    Amirabi, Z. [Eastern Mediterranean Univ., Gazimagusa (Turkey). Dept. of Physics

    2017-07-15

    Some important spacetimes are conformally flat; examples are the Robertson-Walker cosmological metric, the Einstein-de Sitter spacetime, and the Levi-Civita-Bertotti-Robinson and Mannheim metrics. In this paper we construct generic thin shells in conformally flat spacetime supported by a perfect fluid with a linear equation of state, i.e., p = ωσ. It is shown that, for the physical domain of ω, i.e., 0 < ω ≤ 1, such thin shells are not dynamically stable. The stability of the timelike thin shells with the Mannheim spacetime as the outer region is also investigated. (orig.)

  11. Feedforward Tracking Control of Flat Recurrent Fuzzy Systems

    Science.gov (United States)

    Gering, Stefan; Adamy, Jürgen

    2014-12-01

    Flatness based feedforward control has proven to be a feasible solution for the problem of tracking control, which may be applied to a broad class of nonlinear systems. If a flat output of the system is known, the control is often based on a feedforward controller generating a nominal input in combination with a linear controller stabilizing the linearized error dynamics around the trajectory. We show in this paper that the very same idea may be incorporated for tracking control of MIMO recurrent fuzzy systems. Their dynamics is given by means of linguistic differential equations but may be converted into a hybrid system representation, which then serves as the basis for controller synthesis.

  12. Holographic interferometry for early diagnosisof children flat foot

    Directory of Open Access Journals (Sweden)

    Oleg Petrovich Bolshakov

    2015-03-01

    Full Text Available The article presents the first experience ofthe use of holographic interferometr y for earlydiagnosis of the flat foot in 4-5 years old children.13 patients were examined. The results of the clinicalexamination, plantography, and of the graphicalreconstruction of the form of the foot arch basedon the interferogramms of the prints on Pedilen areanalyzed. We revealed typical differences betweenthe form of the foot arches in children with flat foot and children with normal status. The use of the proposed method for early detection of congenital pes valgus and of the signs of “flexible flat” foot is being suggested.

  13. Stationary closed strings in five-dimensional flat spacetime

    Science.gov (United States)

    Igata, Takahisa; Ishihara, Hideki; Nishiwaki, Keisuke

    2012-11-01

    We investigate stationary rotating closed Nambu-Goto strings in five-dimensional flat spacetime. The stationary string is defined as a world sheet that is tangent to a timelike Killing vector. The Nambu-Goto equation of motion for the stationary string is reduced to the geodesic equation on the orbit space of the isometry group action generated by the Killing vector. We take a linear combination of a time-translation vector and space-rotation vectors as the Killing vector, and explicitly construct general solutions of stationary rotating closed strings in five-dimensional flat spacetime. We show a variety of their configurations and properties.

  14. Benchmarking and Performance Improvement at Rocky Flats Environmental Technology Site

    Energy Technology Data Exchange (ETDEWEB)

    Elliott, C. [Kaiser-Hill Co., LLC, Golden, CO (United States)], Doyle, D. [USDOE Rocky Flats Office, Golden, CO (United States)], Featherman, W.D. [Project Performance Corp., Sterline, VA (United States)

    1997-12-31

    The Rocky Flats Environmental Technology Site (RFETS) has initiated a major work process improvement campaign using the tools of formalized benchmarking and streamlining. This paper provides insights into some of the process improvement activities performed at Rocky Flats from November 1995 through December 1996. It reviews the background, motivation, methodology, results, and lessons learned from this ongoing effort. The paper also presents important gains realized through process analysis and improvement including significant cost savings, productivity improvements, and an enhanced understanding of site work processes.

  15. EMG analysis and modelling of flat bench press using artificial ...

    African Journals Online (AJOL)

    The objective of this study was to evaluate the contribution of particular muscle groups during the Flat Bench Press (FBP) with different external loads. Additionally, the authors attempted to determine whether regression models or Artificial Neural Networks (ANNs) can predict FBP results more precisely and whether they can ...

  16. Rocky Flats Cleanup Agreement implementation successes and challenges

    International Nuclear Information System (INIS)

    Shelton, D.C.

    1997-01-01

    On July 19, 1996 the US Department of Energy (DOE), State of Colorado (CDPHE), and US Environmental Protection Agency (EPA) entered into an agreement called the Rocky Flats Cleanup Agreement (RFCA) for the cleanup and closure of the Rocky Flats Environmental Technology Site (RFETS or Rocky Flats). Major elements of the agreement include: an Integrated Site-Wide Baseline; up to twelve significant enforceable milestones per year; agreed upon soil and water action levels and standards for cleanup; open space as the likely foreseeable land use; the plutonium and TRU waste removed by 2015; streamlined regulatory process; agreement with the Defense Nuclear Facilities Safety Board (DNFSB) to coordinate activities; and a risk reduction focus. Successful implementation of RFCA requires a substantial effort by the parties to change their way of thinking about RFETS and meet the deliverables and commitments. Substantial progress toward Site closure through the implementation of RFCA has been accomplished in the short time since the signing, yet much remains to be done. Much can be learned from the Rocky Flats experience by other facilities in similar situations

  17. Cosmic microwave background anisotropies in multiconnected flat spaces

    International Nuclear Information System (INIS)

    Riazuelo, Alain; Weeks, Jeffrey; Uzan, Jean-Philippe; Lehoucq, Roland; Luminet, Jean-Pierre

    2004-01-01

    This article investigates the signature of the seventeen multiconnected flat spaces in cosmic microwave background (CMB) maps. For each such space it recalls a fundamental domain and a set of generating matrices, and then goes on to find an orthonormal basis for the set of eigenmodes of the Laplace operator on that space. The basis eigenmodes are expressed as linear combinations of eigenmodes of the simply connected Euclidean space. A preceding work, which provides a general method for implementing multiconnected topologies in standard CMB codes, is then applied to simulate CMB maps and angular power spectra for each space. Unlike in the 3-torus, the results in most multiconnected flat spaces depend on the location of the observer. This effect is discussed in detail. In particular, it is shown that the correlated circles on a CMB map are generically not back to back, so that negative search of back-to-back circles in the Wilkinson Microwave Anisotropy Probe data does not exclude a vast majority of flat or nearly flat topologies

  18. UPPER EXTREMITY KINEMATICS OF FLAT SERVE IN TENNIS ...

    African Journals Online (AJOL)

    Brian McAllister

    kinematics on the ball velocity at the impact phase of a tennis flat serve. 15 elite male tennis players were recruited to participate in this study (mean age 18.4±3.3 .... For field calibration, a Direct Linear Transformation technique, developed by ...

  19. Intertidal deposits: river mouths, tidal flats, and coastal lagoons

    NARCIS (Netherlands)

    Eisma, D.; Boer, de P.L.; Cadee, G.C.; Dijkema, K.; Ridderinkhof, H.; Phillippart, C.

    1998-01-01

    Intertidal Deposits: River Mouths, Tidal Flats, and Coastal Lagoons combines the authors personal and professional experience with the mass of available literature to present a cohesive overview of intertidal deposits and the widely diverse conditions of their formation worldwide. This includes the

  20. 19 CFR 148.102 - Flat rate of duty.

    Science.gov (United States)

    2010-04-01

    ... (CONTINUED) PERSONAL DECLARATIONS AND EXEMPTIONS Noncommercial Importations of Limited Value § 148.102 Flat... fair retail value in the country of acquisition. (b) American Samoa, Guam, the Northern Mariana Islands..., effective January 1, 2001, and 1.5 percent, effective January 1, 2002, of the fair retail value in the...

  1. Public involvement in cleanup - the Rocky Flats experience

    International Nuclear Information System (INIS)

    Paukert, J.; Pennock, S.; Schassburger, R.

    1992-01-01

    The U.S. Department of Energy's Rocky Flats Plant recently completed and implemented the Rocky Flats Plant Community Relations Plan for public involvement in environmental restoration of the site. The plan was developed in cooperation with the plant's regulators, the U.S. Environmental Protection Agency and the Colorado Department of Health. In addition, citizens near the plant played a significant role in shaping the document through extensive community interviews and public comment. The result of these cooperative efforts is a plan that meets and exceeds the applicable federal and state community relations requirements for a cleanup program. In fact, the U.S. Environmental Protection Agency has used the Rocky Flats Plant Community Relations Plants a model for similar plans at other federal facilities. Plan development, however, is only the starting point for an effective community relations effort. The Rocky Flats Plant and the public will face many challenges together as we implement the plan and build a partnership for addressing environmental cleanup issues. (author)

  2. Inevitable ambiguity in perturbation around flat space-time

    International Nuclear Information System (INIS)

    Ichinose, S.; Kaminaga, Y.

    1989-01-01

    Perturbation of general-relativistic predictions around flat geometry, in general, introduces inevitable ambiguity. The ambiguity reflects the geometrical nature of general relativity and is never a difficulty of it. We explain it by taking a concrete example of the radar-echo experiment

  3. Flat-screen detector systems in skeletal radiology

    International Nuclear Information System (INIS)

    Grampp, S.; Czerny, C.; Krestan, C.; Henk, C.; Heiner, L.; Imhof, H.

    2003-01-01

    Implementation of flat-panel detectors and digital integration of the technique instead of the use of conventional radiographs leads to a shortening of the work process. With flat-panel technology the image production process is shortened by more than 30%. Major advantages in the implementation of integrated RIS, PACS and flat-panel detector system are increases in quality because most mistakes in picture labeling can be avoided, easier handling without the need for cassettes, and the possibility of image post-processing. The diagnostic quality of the images in the field of musculoskeletal radiology is, in comparison to conventional radiographs, at least adequate and in most cases markedly improved with a marked reduction in radiation exposure of around 30-50%. With respect to the numerous advantages of the digital techniques and especially flat-panel technology there is a very high likelihood that conventional radiographs will be substituted in the coming years, even though the cost of the new technology is currently significantly higher compared to conventional systems. (orig.) [de

  4. Asymptotics and Numerics for Laminar Flow over Finite Flat Plate

    NARCIS (Netherlands)

    Dijkstra, D.; Kuerten, J.G.M.; Kaper, Hans G.; Garbey, Mare; Pieper, Gail W.

    1992-01-01

    A compilation of theoretical results from the literature on the finite flat-plate flow at zero incidence is presented. This includes the Blasius solution, the Triple Deck at the trailing edge, asymptotics in the wake, and properties near the edges of the plate. In addition, new formulas for skin

  5. Higher-spin algebras, holography and flat space

    Energy Technology Data Exchange (ETDEWEB)

    Sleight, C. [Max-Planck-Institut für Physik (Werner-Heisenberg-Institut),Föhringer Ring 6, D-80805 Munich (Germany); Université Libre de Bruxelles and International Solvay Institutes,ULB-Campus Plaine CP231, 1050 Brussels (Belgium); Taronna, M. [Université Libre de Bruxelles and International Solvay Institutes,ULB-Campus Plaine CP231, 1050 Brussels (Belgium)

    2017-02-20

    In this article we study the higher-spin algebra behind the type-A cubic couplings recently extracted from the free O(N) model in generic dimensions, demonstrating that they coincide with the known structure constants for the unique higher-spin algebra in generic dimensions. This provides an explicit check of the holographic reconstruction and of the duality between higher-spin theories and the free O(N) model in generic dimensions, generalising the result of Giombi and Yin in AdS{sub 4}. For completeness, we also address the same problem in the flat space for the cubic couplings derived by Metsaev in 1991, which are recovered from the flat limit of the AdS type-A cubic couplings. We observe that both flat and AdS{sub 4} higher-spin Lorentz subalgebras coincide, hinting towards the existence of a full higher-spin symmetry behind the flat-space cubic couplings of Metsaev.

  6. Evaluation of two styles of slotted, flat-head screws

    International Nuclear Information System (INIS)

    Reeves, C.A. Jr.; Johnson, W.B.

    1979-01-01

    A series of torque tests were performed to evaluate the relative merits of two different flat-head screws fabricated from a uranium--6% niobium alloy. The screws tested were machined with both normal, straight-through slots in the head and with slots having radiused bottoms. Test results indicate that both designs easily surpass the required 20-inch-pound-proof torque

  7. Engineering flat electronic bands in quasiperiodic and fractal loop geometries

    Energy Technology Data Exchange (ETDEWEB)

    Nandy, Atanu, E-mail: atanunandy1989@gmail.com; Chakrabarti, Arunava, E-mail: arunava_chakrabarti@yahoo.co.in

    2015-11-06

    Exact construction of one electron eigenstates with flat, non-dispersive bands, and localized over clusters of various sizes is reported for a class of quasi-one-dimensional looped networks. Quasiperiodic Fibonacci and Berker fractal geometries are embedded in the arms of the loop threaded by a uniform magnetic flux. We work out an analytical scheme to unravel the localized single particle states pinned at various atomic sites or over clusters of them. The magnetic field is varied to control, in a subtle way, the extent of localization and the location of the flat band states in energy space. In addition to this we show that an appropriate tuning of the field can lead to a re-entrant behavior of the effective mass of the electron in a band, with a periodic flip in its sign. - Highlights: • Exact construction of eigenstates with flat and dispersive bands is reported. • Competition between translational order and growth of aperiodicity is discussed. • The effect of magnetic field on the location of flat band states is shown. • Flux tunable re-entrant behavior of the effective mass of electron is studied.

  8. Diffractive flat panel solar concentrators of a novel design

    NARCIS (Netherlands)

    De Jong, T.M.; de Boer, D.K.G.; Bastiaansen, C.W.M.

    2016-01-01

    A novel design for a flat panel solar concentrator is presented which is based on a light guide with a grating applied on top that diffracts light into total internal reflection. By combining geometrical and diffractive optics the geometrical concentration ratio is optimized according to the

  9. Possibilities of Obtaining Flat Static Characteristic of DC Ferromagnetic Actuator

    Czech Academy of Sciences Publication Activity Database

    Doležel, Ivo; Dvořák, P.; Mach, M.; Ulrych, B.

    2005-01-01

    Roč. 220, č. 1 (2005), s. 29-39 ISSN 0032-6216 R&D Projects: GA MŠk(CZ) LN00B084 Institutional research plan: CEZ:AV0Z20570509 Keywords : flat static characteristic * DC ferromagnetic actuator Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering

  10. A Broadband Metasurface-Based Terahertz Flat-Lens Array

    KAUST Repository

    Wang, Qiu; Zhang, Xueqian; Xu, Yuehong; Tian, Zhen; Gu, Jianqiang; Yue, Weisheng; Zhang, Shuang; Han, Jiaguang; Zhang, Weili; Zhang, Weili

    2015-01-01

    A metasurface-based terahertz flat-lens array is proposed, comprising C-shaped split-ring resonators exhibiting locally engineerable phase discontinuities. Possessing a high numerical aperture, the planar lens array is flexible, robust, and shows excellent focusing characteristics in a broadband terahertz frequency. It could be an important step towards the development of planar terahertz focusing devices for practical applications.

  11. Adsorption study for uranium in Rocky Flats groundwater

    International Nuclear Information System (INIS)

    Laul, J.C.; Rupert, M.C.; Harris, M.J.; Duran, A.

    1995-01-01

    Six adsorbents were studied to determine their effectiveness in removing uranium in Rocky Flats groundwater. The bench column and batch (Kd) tests showed that uranium can be removed (>99.9%) by four adsorbents. Bone Charcoal (R1O22); F-1 Alumina (granular activated alumina); BIOFIX (immobilized biological agent); SOPBPLUS (mixed metal oxide); Filtrasorb 300 (granular activated carbon); and Zeolite (clinoptilolite)

  12. Design study of flat belt CVT for electric vehicles

    Science.gov (United States)

    Kumm, E. L.

    1980-01-01

    A continuously variable transmission (CVT) was studied, using a novel flat belt pulley arrangement which couples the high speed output shaft of an energy storage flywheel to the drive train of an electric vehicle. A specific CVT arrangement was recommended and its components were selected and sized, based on the design requirements of a 1700 KG vehicle. A design layout was prepared and engineering calculations made of component efficiencies and operating life. The transmission efficiency was calculated to be significantly over 90% with the expected vehicle operation. A design consistent with automotive practice for low future production costs was considered, together with maintainability. The technology advancements required to develop the flat belt CVT were identified and an estimate was made of how the size of the flat belt CVT scales to larger and smaller design output torques. The suitability of the flat belt CVT for alternate application to an electric vehicle powered by an electric motor without flywheel and to a hybrid electric vehicle powered by an electric motor with an internal combustion engine was studied.

  13. Atomically flat platinum films grown on synthetic mica

    Science.gov (United States)

    Tanaka, Hiroyuki; Taniguchi, Masateru

    2018-04-01

    Atomically flat platinum thin films were heteroepitaxially grown on synthetic fluorophlogopite mica [KMg3(AlSi3O10)F2] by van der Waals epitaxy. Platinum films deposited on a fluorophlogopite mica substrate by inductively coupled plasma-assisted sputtering with oxygen introduction on a synthetic mica substrate resulted in the growth of twin single-crystalline epitaxial Pt(111) films.

  14. A survey on conformal flatness and quasiumbilicity of submanifolds

    International Nuclear Information System (INIS)

    Zafindratafa, G.K.

    1989-06-01

    Presently, some confusions are made on the way of understanding the relation and the difference between the conformal flatness and the quasiumbilicity of submanifolds. The purpose of this paper is to make a clarification on these two topics: We review all the up-to-date known main results and the open related problems. (author). 18 refs

  15. Fire-induced reradiation underneath photovoltaic arrays on flat roofs

    DEFF Research Database (Denmark)

    Kristensen, Jens Steemann; Merci, Bart; Jomaas, Grunde

    2018-01-01

    The impact of the reflection of fire-induced heat from a gas burner was studied experimentally to gain knowledge on the interaction between photovoltaic (PV) panels and a fire on flat roofs. The heat flux was measured in a total of eight points at the same level as the top of the gas burner. The ...

  16. Present and future of flat panel detectors in the world

    International Nuclear Information System (INIS)

    Inamura, Kiyonari

    2002-01-01

    Present status of development of flat panel detectors and their clinical application in the world have been surveyed, and future trends are also explored especially in the field of material researches and methods of manufacturing. Also the importance of role of medical physicists on user side is described because characteristic physics measurement of a detector assembly is unavoidable and essential in quality assurance in clinical routine and acceptance test in hospitals. Even though physics measurements and clinical evaluations on flat panel detectors have shown remarkable progress and advances in these several years, future problems of cost down in manufacturing and quality assurance to prevent individual differences between detector assemblies must be resolved. Results of evaluation in mammography, chest radiography, fluoroscopy for cardiovascular examination, bone tumor examination and radiotherapy application indicate that flat panel detectors are future promising materials. Their systematic operation is contributing to heighten accuracy of image examinations and preciseness of radiation therapy. Encouragement to medical physicists relevant to flat panel detectors is also raised in this paper. (author)

  17. An Irrotational Flow Field That Approximates Flat Plate Boundary Conditions

    OpenAIRE

    Ruffa, Anthony A.

    2004-01-01

    An irrotational solution is derived for the steady-state Navier-Stokes equations that approximately satisfies the boundary conditions for flow over a finite flat plate. The nature of the flow differs substantially from boundary layer flow, with severe numerical difficulties in some regions.

  18. The Scale Invariant Synchrotron Jet of Flat Spectrum Radio Quasars

    Indian Academy of Sciences (India)

    2016-01-27

    Jan 27, 2016 ... In this paper, the scale invariance of the synchrotron jet of Flat Spectrum Radio Quasars has been studied using a sample of combined sources from FKM04 and from SDSS DR3 catalogue. Since the research of scale invariance has been focused on sub-Eddington cases that can be fitted onto the ...

  19. A Broadband Metasurface-Based Terahertz Flat-Lens Array

    KAUST Repository

    Wang, Qiu

    2015-02-12

    A metasurface-based terahertz flat-lens array is proposed, comprising C-shaped split-ring resonators exhibiting locally engineerable phase discontinuities. Possessing a high numerical aperture, the planar lens array is flexible, robust, and shows excellent focusing characteristics in a broadband terahertz frequency. It could be an important step towards the development of planar terahertz focusing devices for practical applications.

  20. Dynamic Modeling of Natural Convection Solar Energy Flat Plate ...

    African Journals Online (AJOL)

    The analytical solutions to the dynamic model of an air-heating flat plate solar energy thermal collector were validated by direct measurement from a physical model constructed for that purpose, of the temperatures of the cover and absorber plates, the inlet and outlet fluids, and the ambient air from morning to evening for ...

  1. Virological studies of water from the Cape Flats reclamation plant

    African Journals Online (AJOL)

    4500 m3 of water per day, was constructed at the Cape Flats sewage works and studied over a period of ... In brief, gels were fIxed with methanol 50%, acetic acid 10% for 1 hour, followed by ethanol 10%, acetic acid 0,5% for 1 hour and then ...

  2. The Earth is Flat, and I Can Prove It!

    Science.gov (United States)

    Klinger, Art

    1998-01-01

    Describes an educational program that asks students to attempt to prove that the earth is spherical and that it rotates. Presents tips to pique student interest and charts related to sensing the spin, nonrotation notions, flat earth fallacies, evidence that the earth is spherical and rotates, and the role of watersheds in proving that the earth…

  3. Flat microwave photonic filter based on hybrid of two filters

    International Nuclear Information System (INIS)

    Qi, Chunhui; Pei, Li; Ning, Tigang; Li, Jing; Gao, Song

    2010-01-01

    A new microwave photonic filter (MPF) hybrid of two filters that can realize both multiple taps and a flat bandpass or bandstop response is presented. Based on the phase character of a Mach–Zehnder modulator (MZM), a two taps finite impulse response (FIR) filter is obtained as the first part. The second part is obtained by taking full advantage of the wavelength selectivity of the fiber Bragg grating (FBG) and the gain of a erbium-doped fiber (EDF). Combining the two filters, the flat bandpass or bandstop response is realized by changing the coupler's factor k, the reflectivity of FBG1 R 1 or the gain of the EDF g. Optimizing the system parameters, a flat bandpass response with amplitude depth of more than 45 dB is obtained at k = 0.5, R 1 = 0.33, g = 10, and a flat bandstop response is also obtained at k = 0.4, R 1 = 0.5, g = 2. In addition, the free-spectral range (FSR) can be controlled by changing the length of the EDF and the length difference between two MZMs. The method is proved feasible by some experiments. Such a method offers realistic solutions to support future radio-frequency (RF) optical communication systems

  4. Natural phenomena risk assessment at Rocky Flats Plant

    International Nuclear Information System (INIS)

    Foppe, T.L.

    1985-01-01

    A realistic approach is currently being used at the Rocky Flats Plant to assess the risks of natural phenomena events. The methodology addresses frequency of occurrence estimates, damage stress on the facility and vital equipment, material-at-risk, release fractions and source terms, leakpath, dispersion and dosimetric models, risk curves, and an uncertainty analysis. 28 references, 1 figure

  5. Target aligned heliostat field layout for non-flat terrrain

    CSIR Research Space (South Africa)

    Buck, R

    2012-05-01

    Full Text Available The layout for a solar tower test facility for CSIR, Pretoria, is described. The solar tower system is designed for 400kWth receiver outlet power. The heliostat field layout takes into account both the real (non-flat) topography of the terrain...

  6. Holographic reconstruction and renormalization in asymptotically Ricci-flat spacetimes

    NARCIS (Netherlands)

    Caldeira Costa, R.N.

    2012-01-01

    In this work we elaborate on an extension of the AdS/CFT framework to a sub-class of gravitational theories with vanishing cosmological constant. By building on earlier ideas, we construct a correspondence between Ricci-flat spacetimes admitting asymptotically hyperbolic hypersurfaces and a family

  7. Seismic evaluation of large flat-bottomed tanks

    International Nuclear Information System (INIS)

    Kennedy, R.P.; Kassawara, R.P.

    1990-01-01

    This paper presents a procedure for conservatively evaluating the seismic capacity of flat-bottom fluid storage tanks. The authors know of no case of tank failures at capacity levels less than those predicted by this procedure. Thus, the predicted capacity represents a High Confidence Low Probability of Failure (HCLPF) capacity consistent with earthquake experience. (orig.)

  8. Conformally flat tilted Bianchi Type-V cosmological models in ...

    Indian Academy of Sciences (India)

    the complete determination of these quantities, we assume two extra conditions. First we assume that the space-time is conformally flat which leads to. 1008 .... Discussions. The model starts expanding with a big-bang at М = 0 and the expansion in the model stops at М = ∞ and = -2(Т + 2)¬. The model in general represents.

  9. Flat tori in three-dimensional space and convex integration.

    Science.gov (United States)

    Borrelli, Vincent; Jabrane, Saïd; Lazarus, Francis; Thibert, Boris

    2012-05-08

    It is well-known that the curvature tensor is an isometric invariant of C(2) Riemannian manifolds. This invariant is at the origin of the rigidity observed in Riemannian geometry. In the mid 1950s, Nash amazed the world mathematical community by showing that this rigidity breaks down in regularity C(1). This unexpected flexibility has many paradoxical consequences, one of them is the existence of C(1) isometric embeddings of flat tori into Euclidean three-dimensional space. In the 1970s and 1980s, M. Gromov, revisiting Nash's results introduced convex integration theory offering a general framework to solve this type of geometric problems. In this research, we convert convex integration theory into an algorithm that produces isometric maps of flat tori. We provide an implementation of a convex integration process leading to images of an embedding of a flat torus. The resulting surface reveals a C(1) fractal structure: Although the tangent plane is defined everywhere, the normal vector exhibits a fractal behavior. Isometric embeddings of flat tori may thus appear as a geometric occurrence of a structure that is simultaneously C(1) and fractal. Beyond these results, our implementation demonstrates that convex integration, a theory still confined to specialists, can produce computationally tractable solutions of partial differential relations.

  10. Strategic flat rolling of Ag/BSCCO-2223 tapes

    DEFF Research Database (Denmark)

    Nielsen, Morten Storgård; Bech, Jakob Ilsted; Eriksen, Morten

    2002-01-01

    In the process of single-step flat rolling of multifilament Ag/BSCCO-2223 wire to tape previous work has shown the optimum strategy giving maximum critical current density to be it balance between the length and width strain, so they are of equal size i.e. so, that the logarithmic strain ratio, L...

  11. Características dos Problemas que os Alunos Constroem a partir do Enunciado de uma Questão Aberta de Matemática Characteristics of Problems that Students build from the Enunciation of a Mathematical Open-ended Question

    Directory of Open Access Journals (Sweden)

    João Ricardo Viola dos Santos

    2009-04-01

    Full Text Available O presente artigo apresenta características dos problemas que alunos da 4ª e 8ª série do Ensino Fundamental e 3ª série do Ensino Médio construíram a partir do enunciado de uma questão discursiva, inferidas da sua produção escrita na questão comum da AVA-2002. Esses problemas se caracterizaram, parte por terem uma estrutura de resolução linear constituída a partir de interpretações das informações contidas no enunciado uma a uma sem relacioná-las, e, parte por uma estrutura de resolução não-linear constituída a partir de inter-relações entre as informações contidas no enunciado. A análise da produção escrita se mostra como uma alternativa para os professores conhecerem a atividade matemática dos alunos, bem como seus modos particulares de interpretação de enunciados. Palavras chaves: Educação Matemática. Análise da Produção Escrita. Avaliação em Matemática.The present paper shows characteristics of problems that students of 4th year Elementary School, 8th year Middle School and 3rd year High School built from an open-ended question enunciation, taken from their written work in the common question of AVA-2002 (Paraná State Large-Scale Assessment-2002. These problems have, on one hand, a linear resolution structure built from student interpretation of information of the enunciation, one by one, without connection, and, on other hand, they have a non-linear resolution structure built among information of the enunciation. The analysis of students’ written work is one alternative for teachers to know students' mathematical activity, as well as their particular ways of interpretation of enunciations. Keywords: Mathematics Education. Analysis of written work. Assessment in Mathematics.

  12. Nonconformally flat initial data for binary compact objects

    International Nuclear Information System (INIS)

    Uryu, Koji; Limousin, Francois; Gourgoulhon, Eric; Friedman, John L.; Shibata, Masaru

    2009-01-01

    A new method is described for constructing initial data for a binary neutron-star system in quasiequilibrium circular orbit. Two formulations for nonconformally flat data, waveless and near-zone helically symmetric, are introduced; in each formulation, the Einstein-Euler system, written in 3+1 form on an asymptotically flat spacelike hypersurface, is exactly solved for all metric components, including the spatially nonconformally flat potentials, and for irrotational flow. A numerical method applicable to both formulations is explained with an emphasis on the imposition of a spatial gauge condition. Results are shown for solution sequences of irrotational binary neutron-stars with matter approximated by parametrized equations of state that use a few segments of polytropic equations of state. The binding energy and total angular momentum of solution sequences computed within the conformally flat--Isenberg-Wilson-Mathews--formulation are closer to those of the third post-Newtonian (3PN) two point particles up to the closest orbits, for the more compact stars, whereas sequences resulting from the waveless/near-zone helically symmetric formulations deviate from the 3PN curve even more for the sequences with larger compactness. We think it likely that this correction reflects an overestimation in the Isenberg-Wilson-Mathews formulation as well as in the 3PN formula, by ∼1 cycle in the gravitational-wave phase during the last several orbits. The work suggests that imposing spatial conformal flatness results in an underestimate of the quadrupole deformation of the components of binary neutron-star systems in the last few orbits prior to merger.

  13. Broadband unidirectional cloaks based on flat metasurface focusing lenses

    International Nuclear Information System (INIS)

    Li, Yongfeng; Zhang, Jieqiu; Qu, Shaobo; Wang, Jiafu; Pang, Yongqiang; Xu, Zhuo; Zhang, Anxue

    2015-01-01

    Bandwidth extension and thickness reduction are now the two key issues of cloaks. In this paper, we propose to achieve broadband, thin uni-directional electromagnetic (EM) cloaks using metasurfaces. To this end, a wideband flat focusing lens is firstly devised based on high-efficiency transmissive metasurfaces. Due to the nearly dispersionless parabolic phase profile along the metasurface in the operating band, incident plane waves can be focused efficiently after passing through the metasurface. Broadband unidirectional EM cloaks were then designed by combining two identical flat lenses. Upon illumination, the incident plane waves are firstly focused by one lens and then are restored by the other lens, avoiding the cloaked region. Both simulation and experiment results verify the broadband unidirectional cloak. The broad bandwidth and small thickness of such cloaks have potential applications in achieving invisibility for electrically large objects. (paper)

  14. Broadband unidirectional cloaks based on flat metasurface focusing lenses

    Science.gov (United States)

    Li, Yongfeng; Zhang, Jieqiu; Qu, Shaobo; Wang, Jiafu; Pang, Yongqiang; Xu, Zhuo; Zhang, Anxue

    2015-08-01

    Bandwidth extension and thickness reduction are now the two key issues of cloaks. In this paper, we propose to achieve broadband, thin uni-directional electromagnetic (EM) cloaks using metasurfaces. To this end, a wideband flat focusing lens is firstly devised based on high-efficiency transmissive metasurfaces. Due to the nearly dispersionless parabolic phase profile along the metasurface in the operating band, incident plane waves can be focused efficiently after passing through the metasurface. Broadband unidirectional EM cloaks were then designed by combining two identical flat lenses. Upon illumination, the incident plane waves are firstly focused by one lens and then are restored by the other lens, avoiding the cloaked region. Both simulation and experiment results verify the broadband unidirectional cloak. The broad bandwidth and small thickness of such cloaks have potential applications in achieving invisibility for electrically large objects.

  15. Polymer solidification of mixed wastes at the Rocky Flats Plant

    International Nuclear Information System (INIS)

    Faucette, A.M.; Logsdon, B.W.; Lucerna, J.J.; Yudnich, R.J.

    1994-01-01

    The Rocky Flats Plant is pursuing polymer solidification as a viable treatment option for several mixed waste streams that are subject to land disposal restrictions within the Resource Conservation and Recovery Act provisions. Tests completed to date using both surrogate and actual wastes indicate that polyethylene microencapsulation is a viable treatment option for several mixed wastes at the Rocky Flats Plant, including nitrate salts, sludges, and secondary wastes such as ash. Treatability studies conducted on actual salt waste demonstrated that the process is capable of producing waste forms that comply with all applicable regulatory criteria, including the Toxicity Characteristic Leaching Procedure. Tests have also been conducted to evaluate the feasibility of macroencapsulating certain debris wastes in polymers. Several methods and plastics have been tested for macroencapsulation, including post-consumer recycle and regrind polyethylene

  16. Implementing DOE guidance for hazards assessments at Rocky Flats Plant

    International Nuclear Information System (INIS)

    Zimmerman, G.A.

    1993-01-01

    Hazards Assessments are performed for a variety of activities and facilities at Rocky Flats Plant. Prior to 1991, there was no guidance for performing Hazards Assessments. Each organization that performed Hazards Assessments used its own methodology with no attempt at standardization. In 1991, DOE published guidelines for the performance of Hazards Assessments for Emergency Planning (DOE-EPG-5500.1, ''Guidance for a Hazards Assessment Methodology''). Subsequently, in 1992, DOE published a standard for the performance of Hazards Assessments (DOE-STD-1027-92, ''Hazard Categorization and Accident Analysis, Techniques for Compliance with DOE Order 5480.23, Nuclear Safety Analysis Reports''). Although these documents are a step in the direction of standardization, there remains a great deal of interpretation and subjective implementation in the performance of Hazards Assessments. Rocky Flats Plant has initiated efforts to develop a uniform and standard process to be used for Hazards Assessments

  17. Optical identifications of flat-spectrum radio sources

    International Nuclear Information System (INIS)

    Condon, J.J.; Condon, M.A.; Broderick, J.J.; Davis, M.M.

    1983-01-01

    A complete sample of radio sources with S> or =0.3 Jy at 1400 MHz, +24 0 0 , and low-frequency spectral indices α(408, 1400) or =+0.5 are usually in empty fields. The lower limits that can be assigned to the radio-optical spectral indices α/sub RO/ of these sources are significantly higher than the median α/sub RO/ of the sources with flat high-frequency spectra, so the optical characteristics of the two classes of radio source are intrinsically different. The radio and optical fluxes of flat-spectrum QSO's appear to be correlated, at least when averaged over 10 2 --10 3 yr

  18. Actinide solution processing at the Rocky Flats Environmental Technology Site

    International Nuclear Information System (INIS)

    1995-04-01

    The Department of Energy (DOE) has prepared an Environmental Assessment (EA), DOE/EA-1039, for radioactive solution removal and processing at Rocky Flats Environmental Technology Site, Golden, Colorado. The proposal for solution removal and processing is in response to independent safety assessments and an agreement with the State of Colorado to remove mixed residues at Rocky Flats and reduce the risk of future accidents. Monthly public meetings were held during the scoping and preparation of the EA. The scope of the EA included evaluations of alternative methods and locations of solution processing. A comment period from February 20, 1995 through March 21, 1995 was provided to the public and the State of Colorado to offer written comment on the EA. Comments were received from the State of Colorado and the U.S. Environmental Protection Agency. A response to the agency comments is included in the Final EA

  19. Scalar hairy black holes and solitons in asymptotically flat spacetimes

    International Nuclear Information System (INIS)

    Nucamendi, Ulises; Salgado, Marcelo

    2003-01-01

    A numerical analysis shows that the Einstein field equations allow static and spherically symmetric black hole solutions with scalar-field hair in asymptotically flat spacetimes. When regularity at the origin is imposed (i.e., in the absence of a horizon) globally regular scalar solitons are found. The asymptotically flat solutions are obtained provided that the scalar potential V(φ) of the theory is not positive semidefinite and such that its local minimum is also a zero of the potential, the scalar field settling asymptotically at that minimum. The configurations, although unstable under spherically symmetric linear perturbations, are regular and thus can serve as counterexamples to the no-scalar-hair conjecture

  20. Digital radiography with large-area flat-panel detectors

    International Nuclear Information System (INIS)

    Kotter, E.; Langer, M.

    2002-01-01

    Large-area flat-panel detectors with active readout mechanisms have been on the market for the past 2 years. This article describes different detector technologies. An important distinction is made between detectors with direct and those with indirect conversion of X-rays into electrical charges. Detectors with indirect conversion are built with unstructured or structured scintillators, the latter resulting in less lateral diffusion of emitted light. Some important qualities of flat-panel detectors are discussed. The first phantom and clinical studies published report an image quality at least comparable to that of screen-film systems and a potential for dose reduction. The available studies are summarised in this article. (orig.)

  1. Pair Formation of Hard Core Bosons in Flat Band Systems

    Science.gov (United States)

    Mielke, Andreas

    2018-05-01

    Hard core bosons in a large class of one or two dimensional flat band systems have an upper critical density, below which the ground states can be described completely. At the critical density, the ground states are Wigner crystals. If one adds a particle to the system at the critical density, the ground state and the low lying multi particle states of the system can be described as a Wigner crystal with an additional pair of particles. The energy band for the pair is separated from the rest of the multi-particle spectrum. The proofs use a Gerschgorin type of argument for block diagonally dominant matrices. In certain one-dimensional or tree-like structures one can show that the pair is localised, for example in the chequerboard chain. For this one-dimensional system with periodic boundary condition the energy band for the pair is flat, the pair is localised.

  2. Turbulent thermal boundary layer on a permeable flat plate

    International Nuclear Information System (INIS)

    Vigdorovich, I. I.

    2007-01-01

    Scaling laws are established for the profiles of temperature, turbulent heat flux, rms temperature fluctuation, and wall heat transfer in the turbulent boundary layer on a flat plate with transpiration. In the case of blowing, the temperature distribution represented in scaling variables outside the viscous sublayer has a universal form known from experimental data for flows over impermeable flat plates. In the case of suction, the temperature distribution is described by a one-parameter family of curves. A universal law of heat transfer having the form of a generalized Reynolds analogy provides a basis for representation of the heat flux distributions corresponding to different Reynolds numbers and transpiration velocities in terms of a function of one variable. The results are obtained without invoking any special closure hypotheses

  3. A preparation of thin flat target for RD lifetime measurements

    Energy Technology Data Exchange (ETDEWEB)

    El-Badry, A M; Abdel Samie, Sh; Ahmed, A A [Department of Physics, Faculty of Science, El Minia University, Minia (Egypt); Kuroyanagi, T; Morinobu, S [Tandem Accelerator Laboratory, Department of Physics, Kyushu University, (Japan)

    1997-12-31

    An extreme flatness for a target surface is the most necessary in recoil distance method (RDM). A suitable technique was used for preparing a La target. The {sup 139} La target of thickness 0.22 mg/cm{sup 2} was evaporated onto a very flat soft Au foil of thickness 2 mg/cm{sup 2}. This target was successively used for lifetime measurements of the excited nuclear states in {sup 145} Sm nucleus through the nuclear reaction {sup 139} La ({sup 10} B, 4 n) {sup 145} Sm. Background {gamma} rays produced by the {sup 10} B irradiation for the Au backing and the Pb stopper without the La target were measured. Besides that, the {gamma} rays from residual activities were also measured. 3 figs.

  4. Facility overview for commercial application of selected Rocky Flats facilities

    International Nuclear Information System (INIS)

    1996-11-01

    The purpose of this Facility Overview is to support the Rocky Flats Local Impacts Initiative's Request for Interest, to solicit interest from commercial corporations for utilizing buildings 865 and 883, and the equipment contained within each building, for a commercial venture. In the following sections, this document describes the Rocky Flats Site, the buildings available for lease, the equipment within these buildings, the site services available to a tenant, the human resources available to support operations in buildings 865 and 883, and the environmental condition of the buildings and property. In addition, a brief description is provided of the work performed to date to explore the potential products that might be manufactured in Buildings 865 and 883, and the markets for these products

  5. Flat acoustic lens by acoustic grating with curled slits

    KAUST Repository

    Peng, Pai

    2014-10-01

    We design a flat sub-wavelength lens that can focus acoustic wave. We analytically study the transmission through an acoustic grating with curled slits, which can serve as a material with tunable impedance and refractive index for acoustic waves. The effective parameters rely on the geometry of the slits and are independent of frequency. A flat acoustic focusing lens by such acoustic grating with gradient effective refractive index is designed. The focusing effect is clearly observed in simulations and well predicted by the theory. We demonstrate that despite the large impedance mismatch between the acoustic lens and the matrix, the intensity at the focal point is still high due to Fabry-Perot resonance.

  6. A new method of constructing scalar-flat Kaehler surfaces

    International Nuclear Information System (INIS)

    Kim, Jongsu; Pontecorvo, M.

    1993-10-01

    Building on the work of Donaldson-Friedman we present a geometric way of constructing anti-self-dual hermitian metrics on compact complex surfaces which is based on the relative complex deformations of singular 3-folds with divisors. Some of the consequences are that under a mild condition, fully described by LeBrun-Singer, any blow up of a scalar-flat Kaehler surface admits scalar-flat Kaehler metrics; this is used to prove that such extremal Kaehler metrics exists on an open dense subset of the moduli space of non-minimal ruled surfaces of genus g ≥ 2. Related results have been obtained by LeBrun-Singer. (author). 25 refs

  7. Quantitative respirator man-testing at Rocky Flats

    International Nuclear Information System (INIS)

    Leigh, J.D.

    The dioctyl phthalate quantitative respirator man-testing method used at Rocky Flats is outlined. Using this method, 93 persons trained to use self contained breathing equipment were tested with eight respiratory protective devices. Test results obtained with the seven devices using high efficiency particulate filters are compared to the results obtained with the self contained breathing equipment. Also comparison is made for these results to test results for 1667 other employees

  8. Rocky Flats Plant Site Environmental Report: 1993 Highlights

    Energy Technology Data Exchange (ETDEWEB)

    1993-12-31

    The Rocky Flats Plant Site Environmental Report provides summary information on the plant`s environmental monitoring programs and the results recorded during 1993. The report contains a compliance summary, results of environmental monitoring and other related programs, a review of environmental remediation activities, information on external gamma radiation dose monitoring, and radiation dose estimates for the surrounding population. This section provides an overview of these topics and summarizes more comprehensive discussions found in the main text of this annual report.

  9. Properties of vitrified rocky flats TRUW with different waste loadings

    International Nuclear Information System (INIS)

    Eddy, T.L.; Sears, J.W.; Grandy, J.D.; Miley, D.V.; Erickson, A.W.; Farnsworth, R.N.; Larsen, E.D.

    1994-01-01

    Leach rates, phase structures, and mechanical properties of simulated Rocky Flats Plant 1st and 2nd slate sludge vitrified in an arc melter are described as a function of waste to soil fraction and method of devitrification to produce the glass-ceramic waste form. Volatile, hazardous, and transuranic (TRU) surrogate metals were added to assess dissolution effects. Zirconia and titania were also added to confirm their ability as transuranic-surrogate getters

  10. Detecting topology in a nearly flat spherical universe

    International Nuclear Information System (INIS)

    Weeks, Jeffrey; Lehoucq, Roland; Uzan, Jean-Philippe

    2003-01-01

    When the density parameter is close to unity, the universe has a large curvature radius independent of its being hyperbolic or spherical, or in the limiting case of an infinite curvature radius, flat. Whatever the curvature, the universe may have either a simply connected or a multiply connected topology. In the flat case, the topology scale is arbitrary, and there is no a priori reason for this scale to be of the same order as the size of the observable universe. In the hyperbolic case, any nontrivial topology would almost surely be on a length scale too large to detect. In the spherical case, in contrast, the topology could easily occur on a detectable scale. The present paper shows how, in the spherical case, the assumption of a nearly flat universe simplifies the algorithms for detecting a multiply connected topology, but also reduces the amount of topology that can be seen. This is of primary importance for the upcoming cosmic microwave background data analysis. This paper shows that for spherical spaces one may restrict the search to diametrically opposite pairs of circles in the circles-in-the-sky method and still detect the cyclic factor in the standard factorization of the holonomy group. This vastly decreases the algorithm's run time. If the search is widened to include pairs of candidate circles whose centres are almost opposite and whose relative twist varies slightly, then the cyclic factor along with a cyclic subgroup of the general factor may also be detected. Unfortunately, the full holonomy group is, in general, unobservable in a nearly flat spherical universe, and so a full six-parameter search is unnecessary. Crystallographic methods could also potentially detect the cyclic factor and a cyclic subgroup of the general factor, but nothing else

  11. Detecting topology in a nearly flat hyperbolic universe

    OpenAIRE

    Weeks, Jeffrey R.

    2002-01-01

    Cosmic microwave background data shows the observable universe to be nearly flat, but leaves open the question of whether it is simply or multiply connected. Several authors have investigated whether the topology of a multiply connect hyperbolic universe would be detectable when 0.9 < Omega < 1. However, the possibility of detecting a given topology varies depending on the location of the observer within the space. Recent studies have assumed the observer sits at a favorable location. The pre...

  12. Detecting topology in a nearly flat spherical universe

    Energy Technology Data Exchange (ETDEWEB)

    Weeks, Jeffrey [15 Farmer St, Canton NY 13617-1120 (United States); Lehoucq, Roland [CE-Saclay, DSM/DAPNIA/Service d' Astrophysique, F-91191 Gif sur Yvette Cedex (France); Uzan, Jean-Philippe [Institut d' Astrophysique de Paris, GReCO, CNRS-FRE 2435, 98 bis, Bd Arago, 75014 Paris (France)

    2003-04-21

    When the density parameter is close to unity, the universe has a large curvature radius independent of its being hyperbolic or spherical, or in the limiting case of an infinite curvature radius, flat. Whatever the curvature, the universe may have either a simply connected or a multiply connected topology. In the flat case, the topology scale is arbitrary, and there is no a priori reason for this scale to be of the same order as the size of the observable universe. In the hyperbolic case, any nontrivial topology would almost surely be on a length scale too large to detect. In the spherical case, in contrast, the topology could easily occur on a detectable scale. The present paper shows how, in the spherical case, the assumption of a nearly flat universe simplifies the algorithms for detecting a multiply connected topology, but also reduces the amount of topology that can be seen. This is of primary importance for the upcoming cosmic microwave background data analysis. This paper shows that for spherical spaces one may restrict the search to diametrically opposite pairs of circles in the circles-in-the-sky method and still detect the cyclic factor in the standard factorization of the holonomy group. This vastly decreases the algorithm's run time. If the search is widened to include pairs of candidate circles whose centres are almost opposite and whose relative twist varies slightly, then the cyclic factor along with a cyclic subgroup of the general factor may also be detected. Unfortunately, the full holonomy group is, in general, unobservable in a nearly flat spherical universe, and so a full six-parameter search is unnecessary. Crystallographic methods could also potentially detect the cyclic factor and a cyclic subgroup of the general factor, but nothing else.

  13. Wind flow simulation over flat terrain using CFD based software

    International Nuclear Information System (INIS)

    Petrov, Peter; Terziev, Angel; Genovski, Ivan

    2009-01-01

    Velocity distribution recognition over definite place (terrain) is very important because due to that the zones with high energy potential could be defined (the fields with high velocities). This is a precondition for optimal wind turbine generators micro-sitting. In current work a simulation of the open flow over the flat terrain using the CFD based software is reviewed. The simulations are made of a real fluid flow in order to be defined the velocity fields over the terrain

  14. Flat panel planar optic display. Revision 4/95

    Energy Technology Data Exchange (ETDEWEB)

    Veligdan, J.T.

    1995-05-01

    A prototype 10 inch flat panel Planar Optic display, (POD), screen has been constructed and tested. This display screen is comprised of hundreds of planar optic glass sheets bonded together with a cladding layer between each sheet where each glass sheet represents a vertical line of resolution. The display is 9 inches wide by 5 inches high and approximately 1 inch thick. A 3 milliwatt HeNe laser is used as the illumination source and a vector scanning technique is employed.

  15. Quantitative respirator man-testing at Rocky Flats

    Energy Technology Data Exchange (ETDEWEB)

    Leigh, J. D.

    1978-01-01

    The dioctyl phthalate quantitative respirator man-testing method used at Rocky Flats is outlined. Using this method, 93 persons trained to use self contained breathing equipment were tested with eight respiratory protective devices. Test results obtained with the seven devices using high efficiency particulate filters are compared to the results obtained with the self contained breathing equipment. Also comparison is made for these results to test results for 1667 other employees.

  16. Transmission of electrons with flat passbands in finite superlattices

    International Nuclear Information System (INIS)

    Barajas-Aguilar, A H; Rodríguez-Magdaleno, K A; Martínez-Orozco, J C; Enciso-Muñoz, A; Contreras-Solorio, D A

    2013-01-01

    Using the transfer matrix method and the Ben Daniel-Duke equation for variable mass electrons propagation, we calculate the transmittance for symmetric finite superlattices where the width and the height of the potential barriers follow a linear dependence. The width and height of the barriers decreases from the center to the ends of the superlattice. The transmittance presents intervals of stopbands and quite flat passbands.

  17. Maximally flat radiation patterns of a circular aperture

    Science.gov (United States)

    Minkovich, B. M.; Mints, M. Ia.

    1989-08-01

    The paper presents an explicit solution to the problems of maximizing the area utilization coefficient and of obtaining the best approximation (on the average) of a sectorial Pi-shaped radiation pattern of an antenna with a circular aperture when Butterworth conditions are imposed on the approximating pattern with the aim of flattening it. Constraints on the choice of admissible minimum and maximum antenna dimensions are determined which make possible the synthesis of maximally flat patterns with small sidelobes.

  18. Design of optimal linear antennas with maximally flat radiation patterns

    Science.gov (United States)

    Minkovich, B. M.; Mints, M. Ia.

    1990-02-01

    The paper presents an explicit solution to the problem of maximizing the aperture area utilization coefficient and obtaining the best approximation in the mean of the sectorial U-shaped radiation pattern of a linear antenna, when Butterworth flattening constraints are imposed on the approximating pattern. Constraints are established on the choice of the smallest and large antenna dimensions that make it possible to obtain maximally flat patterns, having a low sidelobe level and free from pulsations within the main lobe.

  19. Diffractive flat panel solar concentrators of a novel design.

    Science.gov (United States)

    de Jong, Ties M; de Boer, Dick K G; Bastiaansen, Cees W M

    2016-07-11

    A novel design for a flat panel solar concentrator is presented which is based on a light guide with a grating applied on top that diffracts light into total internal reflection. By combining geometrical and diffractive optics the geometrical concentration ratio is optimized according to the principles of nonimaging optics, while the thickness of the device is minimized due to the use of total internal reflection.

  20. SUSY Flat Directions - to get a VEV or not?

    International Nuclear Information System (INIS)

    Basboell, Anders

    2010-01-01

    We investigate the potential of SUSY flat directions (FDs). Large FD vacuum expectation values (VEVs) can delay thermalisation and solve the gravitino problem--if FDs decay perturbatively. This depends on how many and which directions get the VEVs. Recently the decay of the FDs have been studied with the VEVs as input. Here we look at how the VEVs come about--statistically and analytically.