Nanoscale insight of high piezoelectricity in high-TC PMN-PH-PT ceramics

Science.gov (United States)

Zhu, Rongfeng; Zhang, Qihui; Fang, Bijun; Zhang, Shuai; Zhao, Xiangyong; Ding, Jianning

2018-03-01

The piezoelectric properties of the high-Curie temperature (high-TC) 0.15Pb(Mg1/3Nb2/3)O3-0.38PbHfO3-0.47PbTiO3 (0.15PMN-0.38PH-0.47PT) ceramics prepared by three different methods were compared. The 0.15PMN-0.38PH-0.47PT ceramics synthesized by the partial oxalate route exhibit the optimum properties, in which d33* = 845.3 pm/V, d33 = 456.2 pC/N, Kp = 67.2%, and TC = 291 °C. The nanoscale origin of the high piezoelectric response of the 0.15PMN-0.38PH-0.47PT ceramics was investigated by piezoresponse force microscopy (PFM) using the ceramics synthesized by the partial oxalate route. Large quantities of fine stripe submicron ferroelectric domains are observed, which form large island domains. In order to give further insights into the piezoelectric properties of the 0.15PMN-0.38PH-0.47PT ceramics from a microscopic point of view, the local poling experiments and local switching spectroscopy piezoresponse force microscopy (SS-PFM) were investigated, from which the local converse piezoelectric coefficient d33*(l) is calculated as 220 pm/V.

Comparison of PZN-PT, PMN-PT single crystals and PZT ceramic for vibration energy harvesting

International Nuclear Information System (INIS)

Yang, Zhengbao; Zu, Jean

2016-01-01

Highlights: • Systematic analysis of PMN-PT and PZN-PT single crystals for energy harvesters. • Performance analysis and comparison under various conditions. • Discussion of the effect of the SSHI technique on single crystal energy harvesters. • Efficiency analysis in both on-resonance and off-resonance conditions. - Abstract: Vibration energy harvesting has a great potential to achieve self-powered operations for wireless sensors, wearable devices and medical electronics, and thus has attracted much attention in academia and industry. The majority of research into this subject has focused on the piezoelectric effect of synthetic materials, especially the perovskite PZT ceramics. Recently the new-generation piezoelectric materials PMN-PT and PZN-PT single crystals have gained significant interest because of their outstanding piezoelectric properties. They can be used to replace the widely-adopted PZT ceramics for improving energy harvesters’ performance substantially. However, there is little research on comparing PMN-PT and PZN-PT energy harvesters against PZT harvesters. In this paper, we present a systematic comparison between vibration energy harvesters using the PMN-PT, PZN-PT single crystals and those using the PZT ceramics. Key properties of the three materials are summarized and compared. The performance of the PMN-PT and PZN-PT energy harvesters is characterized under different conditions (beam length, resistance, frequency, excitation strength, and backward coupling effect), and is quantitatively compared with the PZT counterpart. Furthermore, the effect of the synchronized switch harvesting on inductor (SSHI) circuit on the three harvesters is discussed. The experimental results indicate that energy harvesters using the PMN-PT and PZN-PT single crystals can significantly outperform those using the PZT ceramics. This study provides a strong base for future research on high-performance energy harvesters using the new PMN-PT and PZN-PT single

Structural health monitoring of glass/epoxy composite plates with MEMS PMN-PT sensors

Science.gov (United States)

Simon, Brenton R.; Tang, Hong-Yue; Horsley, David A.; La Saponara, Valeria; Lestari, Wahyu

2009-03-01

Sensors constructed with single-crystal PMN-PT, i.e. Pb(Mg1/3Nb2/3)O3-PbTiO3 or PMN, are developed in this paper for structural health monitoring of composite plates. To determine the potential of PMN-PT for this application, glass/epoxy composite specimens were created containing an embedded delamination-starter. Two different piezoelectric materials were bonded to the surface of each specimen: PMN-PT, the test material, was placed on one side of the specimen, while a traditional material, PZT-4, was placed on the other. A comparison of the ability of both materials to transmit and receive an ultrasonic pulse was conducted, with the received signal detected by both a second surface-bonded transducer constructed of the same material, as well as a laser Doppler vibrometer (LDV) analyzing the same location. The optimal frequency range of both sets of transducers is discussed and a comparison is presented of the experimental results to theory. The specimens will be fatigued until failure with further data collected every 3,000 cycles to characterize the ability of each material to detect the growing delamination in the composite structure. This additional information will be made available during the conference.

Aging and Barkhausen Noise in the Relaxor Ferroelectric SBN:La and PMN/PT

Science.gov (United States)

Chao, Lambert K.; Colla, Eugene V.; Weissman, M. B.

2003-03-01

Relaxor ferroelectrics form a diverse class of materials which exhibit frequency-dependent freezing into a disordered state. The relation to other cooperative glassy freezing, such as in spin glasses, remain uncertain. Previous aging investigations on several relaxors already indicate diverse behavior (E.V. Colla phet al., Phys. Rev. B 63, 134107 (2001)). We present results on aging behavior on PMN/PT (90/10) and SBN:La. SBN:La, believed to fit a random-field Ising model, exhibits complicated aging behavior with a low-temperature regime lacking the memory effects characteristic of spin-glass-like aging seen in the perovskites PMN and PMN/PT. Further information on the glassy freezing is provided via Barkhausen noise experiments using a balanced capacitance bridge technique capable of measuring random noise despite a large systematic background signal [E.V. Colla phet al., Phys. Rev. Lett. 88 017601 (2002).].

Regulation of Endothelial Cell Inflammation and Lung PMN Infiltration by Transglutaminase 2

Science.gov (United States)

Bijli, Kaiser M.; Kanter, Bryce G.; Minhajuddin, Mohammad; Leonard, Antony; Xu, Lei; Fazal, Fabeha; Rahman, Arshad

2014-01-01

We addressed the role of transglutaminase2 (TG2), a calcium-dependent enzyme that catalyzes crosslinking of proteins, in the mechanism of endothelial cell (EC) inflammation and lung PMN infiltration. Exposure of EC to thrombin, a procoagulant and proinflammatory mediator, resulted in activation of the transcription factor NF-κB and its target genes, VCAM-1, MCP-1, and IL-6. RNAi knockdown of TG2 inhibited these responses. Analysis of NF-κB activation pathway showed that TG2 knockdown was associated with inhibition of thrombin-induced DNA binding as well as serine phosphorylation of RelA/p65, a crucial event that controls transcriptional capacity of the DNA-bound RelA/p65. These results implicate an important role for TG2 in mediating EC inflammation by promoting DNA binding and transcriptional activity of RelA/p65. Because thrombin is released in high amounts during sepsis and its concentration is elevated in plasma and lavage fluids of patients with Acute Respiratory Distress Syndrome (ARDS), we determined the in vivo relevance of TG2 in a mouse model of sepsis-induced lung PMN recruitment. A marked reduction in NF-κB activation, adhesion molecule expression, and lung PMN sequestration was observed in TG2 knockout mice compared to wild type mice exposed to endotoxemia. Together, these results identify TG2 as an important mediator of EC inflammation and lung PMN sequestration associated with intravascular coagulation and sepsis. PMID:25057925

Raman selection rules and tensor elements for PMN-0.3PT single crystal

International Nuclear Information System (INIS)

Ge, Wanyin; Zhu, Wenliang; Pezzotti, Giuseppe

2009-01-01

Selection rules were put forward theoretically and Raman tensor elements experimentally determined for PMN-0.3PT single-crystal. Such a body of information was then employed to evaluate local domain orientation in a relaxor-based PMN-0.3PT material by means of polarized microprobe Raman spectroscopy. The dependence of Raman spectra upon crystal rotation under different polarized probe configurations was experimentally confirmed by collecting the intensity variation of selected Raman modes on Euler's angle rotation in a poled single-crystal. The periodicity of relative Raman intensity of selected Raman bands revealed symmetry properties. Upon exploiting such properties and with the knowledge of the Raman tensor elements from the A g and E g vibrational modes, a viable path becomes available to determine domain texture in relaxor-based PMN-PT materials with high spatial resolution. (copyright 2009 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

Features of dielectric response in PMN-PT ferroelectric ceramics

International Nuclear Information System (INIS)

Guerra, J D S; Araujo, E B; Guarany, C A; Reis, R N; Lima, E C

2008-01-01

In this paper, electrical and structural properties were reported for pyrochlore free (1 - x)[Pb(Mg 1/3 Nb 2/3 )O 3 ] - xPbTiO 3 (PMN-PT) (with 35 mol% PbTiO 3 ) ceramics obtained from fine powders. Dielectric studies were focused on the investigation of the complex dielectric permittivity (ε' - iε'') as a function of frequency and temperature. The effects of the dc applied electric field on dielectric response were also investigated. Results revealed a field dependence dielectric anomaly in the dielectric permittivity curves (ε(T)) in the low dc electric field region, which in turn prevails in the whole analysed frequency interval. To the best of our knowledge, these properties for the PMN-PT ceramic system have not been reported before as in this work. The results were analysed within the framework of the current models found in the literature.

Effect of manganese doping on PIN-PMN-PT single crystals for high power applications

Science.gov (United States)

Sahul, Raffi

Single crystals based on relaxor-lead titanate (relaxor-PT) solid solutions have advanced the world of piezoelectric materials for the past two decades with their giant piezoelectric properties achieved by domain engineered configurations. When single crystals of lead magnesium niobate-lead titanate (PMN-PT) solid solution in the rhombohedral phase were poled along [001]c direction with "4R" domain configuration, they exhibited high piezoelectric charge coefficient (d33 >2000 pC/N) and high electromechanical coupling (k33 >0.9) which led to their widespread use in advanced medical imaging systems and underwater acoustic devices. However, PMN-PT crystals suffer from low phase transition temperature (Trt ˜85-95 °C) and lower coercive field (depolarizing electric field, Ec ˜2-3 kV/cm). Lead indium niobate - lead magnesium niobate - lead titanate (PIN-PMN-PT) ternary single crystals formed by adding indium as another constituent exhibit higher coercive field (E c ˜5kV/cm) and higher Curie temperature (Tc >210 °C) than the binary PMN-PT crystals (Ec ˜2.5 kV/cm and Tc high mechanical Q-factor (Qm >600) compared to the undoped binary crystals (Qm of PMN-PT 2000 pC/N for PMN-PT) occurs in the [001]c poled crystals, which is attributed to the polarization rotation mechanisms. Hence, domain engineering configurations induced by poling these crystals in orientations other than their polarization axis are critical for achieving large piezoelectric effects. Based on the phase diagram of these solid solutions, with the increase in PT content beyond the rhombohedral phase region, orthorhombic/monoclinic and tetragonal phases are formed. In the orthorhombic and tetragonal phases, the spontaneous polarization directions are in the [011]c and [001] c directions respectively. Similar to the "4R" domain configuration achieved in [001]c poled rhombohedral crystals, other domain configurations can be achieved by poling the single crystals in different orientations, leading to

Air-Coupled Low Frequency Ultrasonic Transducers and Arrays with PMN-32%PT Piezoelectric Crystals

Directory of Open Access Journals (Sweden)

Rymantas J. Kazys

2017-01-01

Full Text Available Air-coupled ultrasonic techniques are being increasingly used for material characterization, non-destructive evaluation of composite materials using guided waves as well as for distance measurements. Application of those techniques is mainly limited by the big losses of ultrasonic signals due to attenuation and mismatch of the acoustic impedances of ultrasonic transducers and air. One of the ways to solve this problem is by application of novel more efficient piezoelectric materials like lead magnesium niobate-lead titanate (PMN-PT type crystals. The objective of this research was the development and investigation of low frequency (<50 kHz wide band air-coupled ultrasonic transducers and arrays with an improved performance using PMN-32%PT crystals. Results of finite element modelling and experimental investigations of the developed transducers and arrays are presented. For improvement of the performance strip-like matching elements made of low acoustic impedance, materials such as polystyrene foams were applied. It allowed to achieve transduction losses for one single element transducer −11.4 dB, what is better than of commercially available air-coupled ultrasonic transducers. Theoretical and experimental investigations of the acoustic fields radiated by the eight element ultrasonic array demonstrated not only a good performance of the array in a pulse mode, but also very good possibilities to electronically focus and steer the ultrasonic beam in space.

Twistor space, Minkowski space and the conformal group

International Nuclear Information System (INIS)

Broek, P.M. van den

1983-01-01

It is shown that the conformal group of compactified Minkowski space is isomorphic to a group of rays of semilinear transformations of twistor space. The action of the conformal group on twistor space is given by an explicit realisation of this isomorphism. In this way we determine the transformation of twistor space under space inversion and time inversion. (orig.)

A possible scenario for two soft branches in PMN

Czech Academy of Sciences Publication Activity Database

Kempa, Martin; Hlinka, Jiří

2011-01-01

Roč. 84, 9-10 (2011), s. 784-788 ISSN 0141-1594 R&D Projects: GA ČR GAP204/10/0616 Institutional research plan: CEZ:AV0Z10100520 Keywords : PMN relaxor * waterfall phenomenon * phonon dispersions * inelastic scattering Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 1.006, year: 2011

Study of liquid scintillator in detecting the PMN-CL, Ly-CL and extracellular matrix in liver fibrosis

International Nuclear Information System (INIS)

Li Tianxing; Cao Rui; Liang Qizhong; Zou Xiaowei

1997-01-01

Chemiluminescence (CL) of polymorphonuclear (PMN) and lymphocyte(Ly) in blood of patients with cirrhosis has two peaks. Basic peak value of PMN-CL and Ly-CL is increased, the maximal peak values of Zym-PMN and PHA-Ly are decreased, phagolyosis and opsonic function is also decreased, extracellular matrix (ECM) is all increased, HA is positively correlated with 'child' sort (r = 0.96, A>B>C). It suggests that OR is produced and released during CL and superoxide phosphatides is produced by OR in ECM of cirrhosis. It injures the membrane of cells and tissue. Analysis of CL is aided to study the development mechanism of liver fibrosis

Tamm-Horsfall Glycoprotein Enhances PMN Phagocytosis by Binding to Cell Surface-Expressed Lactoferrin and Cathepsin G That Activates MAP Kinase Pathway

Directory of Open Access Journals (Sweden)

Chia-Li Yu

2011-03-01

Full Text Available The molecular basis of polymorphonuclear neutrophil (PMN phagocytosis-enhancing activity (PEA by human purified urinary Tamm-Horsfall glyco- protein (THP has not been elucidated. In this study, we found human THP bound to lactoferrin (LF and cathepsin G (CG expressed on the surface of PMN, identified by a proteomic study with MALDI-TOF- LC/LC/mass spectrometric analysis. Pre-incubation of 10% SDS-PAGE electrophoresed PMN lysates with monoclonal anti-LF or anti-CG antibody reduced the binding with THP. To elucidate the signaling pathway of THP on PMN activation, we found THP enhanced ERK1/2 phosphorylation, reduced p38 MAP kinase phosphorylation, but had no effect on DNA binding of the five NF-kB family members in PMN. To further clarify whether the carbohydrate-side chains or protein-core structure in THP molecule is responsible for THP-PEA, THP was cleaved by different degrading enzymes with carbohydrate specificity (neuraminidase and β-galactosidase, protein specificity (V8 protease and proteinase K or glycoconjugate specificity (carboxylpeptidase Y and O-sialoglycoprotein endopeptidase. We clearly demonstrated that the intact protein-core structure in THP molecule was more important for THP-PEA than carbohydrate-side chains. Putting these results together, we conclude that THP adheres to surface-expressed LF and CG on PMN and transduces signaling via the MAP kinase pathway to enhance PMN phagocytosis.

Twistor space, Minkowski space and the conformal group

NARCIS (Netherlands)

van den Broek, P.M.

1983-01-01

It is shown that the conformal group of compactified Minkowski space is isomorphic to a group of rays of semilinear transformations of twistor space. The action of the conformal group on twistor space is given by an explicit realisation of this isomorphism. In this way we determine the

In-plane electric field controlled ferromagnetism and anisotropic magnetoresistance in an LSMO/PMN-PT heterostructure

Science.gov (United States)

Guo, Qi; Xu, Xiaoguang; Wang, Fang; Lu, Yunhao; Chen, Jikun; Wu, Yanjun; Meng, Kangkang; Wu, Yong; Miao, Jun; Jiang, Yong

2018-06-01

We report the in-plane electric field controlled ferromagnetism of La2/3Sr1/3MnO3 (LSMO) films epitaxially deposited on [Pb(Mg1/3Nb2/3)O3]0.7-(PbTiO3)0.3 (PMN-PT) (001), (011) and (111) single crystal substrates. The in-plane coercivities (H c∥) and remanences of the LSMO films greatly depend on the in-plane electric field applied on the PMN-PT (001) and (011) substrates. The experimental change of H c∥ is consistent with the Stoner–Wohlfarth model and first principle calculation with the electric field varying from ‑10 to 10 kV cm‑1. Moreover, the Curie temperature and anisotropic magnetoresistance of the LSMO films can also be manipulated by an in-plane electric field. Finally, the LSMO/PMN-PT (001) heterostructure is designed to be a new kind of magnetic signal generator with the source of electric field.

Cofiring behavior and interfacial structure of NiCuZn ferrite/PMN ferroelectrics composites for multilayer LC filters

International Nuclear Information System (INIS)

Miao Chunlin; Zhou Ji; Cui Xuemin; Wang Xiaohui; Yue Zhenxing; Li Longtu

2006-01-01

The cofiring behavior, interfacial structure and cofiring migration between NiCuZn ferrite and lead magnesium niobate (PMN)-based relaxor ferroelectric materials were investigated via thermomechanical analyzer (TMA), X-ray diffractometer (XRD), scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS). Mismatched sintering shrinkage between NiCuZn ferrite and PMN was modified by adding an appropriate amount of sintering aids, Bi 2 O 3 , into NiCuZn ferrite. Pyrochlore phase appeared in the mixture of NiCuZn ferrite and PMN, which is detrimental to the final electric properties of LC filters. EDS results indicated that the interdiffusion at the heterogeneous interfaces in the composites, such as Fe, Pb, Zn, existed which can strengthen combinations between ferrite layers and ferroelectrics layers

Combined wet-chemical process to synthesize 65PMN-35PT nanosized powders

International Nuclear Information System (INIS)

Santos, Luis P.S.; Longo, Elson; Leite, Edson R.; Camargo, Emerson R.

2004-01-01

Columbite MgNb 2 O 6 precursors were synthesized by a wet-chemical method by means of the dissolution of Nb 2 O 5 .5H 2 O and magnesium carbonate in a solution of oxalic acid. Pure 65PMN-35PT powders could be obtained by the columbite method with the use of the partial oxalate and oxidant peroxo methods. Powders were characterized by X-ray diffraction and FT-Raman spectroscopy showing that pure 65PMN-35PT are obtained when the powders are calcined up to 800 deg. C, without any trace of Pb-Nb pyrochlore. Cubic Pb 1,86 Mg 0.24 Nb 1.76 O 6.5 pyrochlore phase is formed by lead loss in the powders calcined at 900 deg. C and higher temperatures as undoubtedly characterized by Raman spectroscopy

Spectral Variation of NLS1 Galaxy PMN J0948+0022

Indian Academy of Sciences (India)

2016-01-27

Jan 27, 2016 ... Four well-sampled Spectral Energy Distributions (SEDs) of PMN J0948+0022 are fitted with the syn+SSC+EC model to derive the physical parameters of its jets and to investigate the spectral variations of its SEDs. A tentative correlation between the peak luminosity (c) and peak frequency (c) of its ...

Electric-field tunable spin diode FMR in patterned PMN-PT/NiFe structures

Energy Technology Data Exchange (ETDEWEB)

Ziętek, Slawomir, E-mail: zietek@agh.edu.pl; Skowroński, Witold; Stobiecki, Tomasz [AGH University of Science and Technology, Department of Electronics, Al. Mickiewicza 30, 30-059 Kraków (Poland); Ogrodnik, Piotr, E-mail: piotrogr@if.pw.edu.pl [AGH University of Science and Technology, Department of Electronics, Al. Mickiewicza 30, 30-059 Kraków (Poland); Faculty of Physics, Warsaw University of Technology, ul. Koszykowa 75, 00-662 Warszawa (Poland); Stobiecki, Feliks [Institute of Molecular Physics, Polish Academy of Sciences, ul. Smoluchowskiego 17, 60-179 Poznań (Poland); Dijken, Sebastiaan van [NanoSpin, Department of Applied Physics, Aalto University School of Science, P.O. Box 15100, FI-00076 Aalto (Finland); Barnaś, Józef [Faculty of Physics, Adam Mickiewicz University, ul. Umultowska 85, 61-614 Poznań (Poland); Institute of Molecular Physics, Polish Academy of Sciences, ul. Smoluchowskiego 17, 60-179 Poznań (Poland)

2016-08-15

Dynamic properties of NiFe thin films on PMN-PT piezoelectric substrate are investigated using the spin-diode method. Ferromagnetic resonance (FMR) spectra of microstrips with varying width are measured as a function of magnetic field and frequency. The FMR frequency is shown to depend on the electric field applied across the substrate, which induces strain in the NiFe layer. Electric field tunability of up to 100 MHz per 1 kV/cm is achieved. An analytical model based on total energy minimization and the Landau-Lifshitz-Gilbert equation, taking into account the magnetostriction effect, is used to explain the measured dynamics. Based on this model, conditions for optimal electric-field tunable spin diode FMR in patterned NiFe/PMN-PT structures are derived.

Human dental stem cells suppress PMN activity after infection with the periodontopathogens Prevotella intermedia and Tannerella forsythia

Science.gov (United States)

Hieke, Cathleen; Kriebel, Katja; Engelmann, Robby; Müller-Hilke, Brigitte; Lang, Hermann; Kreikemeyer, Bernd

2016-01-01

Periodontitis is characterized by inflammation associated with the colonization of different oral pathogens. We here aimed to investigate how bacteria and host cells shape their environment in order to limit inflammation and tissue damage in the presence of the pathogen. Human dental follicle stem cells (hDFSCs) were co-cultured with gram-negative P. intermedia and T. forsythia and were quantified for adherence and internalization as well as migration and interleukin secretion. To delineate hDFSC-specific effects, gingival epithelial cells (Ca9-22) were used as controls. Direct effects of hDFSCs on neutrophils (PMN) after interaction with bacteria were analyzed via chemotactic attraction, phagocytic activity and NET formation. We show that P. intermedia and T. forsythia adhere to and internalize into hDFSCs. This infection decreased the migratory capacity of the hDFSCs by 50%, did not disturb hDFSC differentiation potential and provoked an increase in IL-6 and IL-8 secretion while leaving IL-10 levels unaltered. These environmental modulations correlated with reduced PMN chemotaxis, phagocytic activity and NET formation. Our results suggest that P. intermedia and T. forsythia infected hDFSCs maintain their stem cell functionality, reduce PMN-induced tissue and bone degradation via suppression of PMN-activity, and at the same time allow for the survival of the oral pathogens. PMID:27974831

Pulmonary alveolar macrophages (PAM) engulf and regain elastin particles and do not respond to some stimuli of neutrophil (PMN) elastinolysis

International Nuclear Information System (INIS)

Tricomi, S.M.; Hyers, T.M.; Yu, S.Y.; Liao, J.J.

1986-01-01

Elastin degradation by PMN and by PAM differs in the proteinases produced and in the method of cellular attack on the substrate. To further characterize the elastinolytic mechanisms of these two cells, 14 C-labelled bovine ligament elastin was dried onto 24-well culture plates and live cells were placed on the substrate in culture medium. Incubation times were 4 hours for PMN and 20 hours for PAM. Elastinolytic activity was determined by counting 14 C-elastin peptides in the supernatant. By lidocaine release of PAM from the surface, 14 C-elastin retained by the cell was measured. Studies on rabbit PAM showed that 40% of dpm remain associated with the cell at 20 hours. Transmission electron microscopy of human PAM confirmed that PAM can engulf and retain elastin particles at 4 and 24 hours of incubation when in close contact with the substrate. Of the number of dpm released by PMN in 4 hours, PAM in 20 hours released only 23% of that number into supernatant and retained 17% closely associated with the cell after lidocaine treatment. Platelet factor 4, a protein released by platelets upon aggregation which stimulates activity of PMN elastase on elastin, was shown to enhance elastinolysis by whole PMN by 57% at 10 μg/ml in this assay. Platelet factor 4 did not enhance elastinolysis by PAM at concentrations up to 100 μg/ml

Affinity Spaces and 21st Century Learning

Science.gov (United States)

Gee, James Paul

2017-01-01

This article discusses video games as "attractors" to "affinity spaces." It argues that affinity spaces are key sites today where people teach and learn 21st Century skills. While affinity spaces are proliferating on the Internet as interest-and-passion-driven sites devoted to a common set of endeavors, they are not new, just…

PMN-Portuguese Meteor Network and OLA-Observatório do Lago Alqueva agreement

Science.gov (United States)

Saraiva, C.

2018-01-01

The PMN-Portuguese Meteor Network has two new video meteor detecting systems at OLA- Observartório do Lago Alqueva, situated at the South East Portuguese territory with a pristine night sky and more than 290 clear nights each year.

Simple derivation of magnetic space groups

International Nuclear Information System (INIS)

Bertaut, E.F.; CEA Centre d'Etudes Nucleaires de Grenoble, 38

1975-01-01

The magnetic translation lattices can be described by invariant wave vectors k. Advantages of the wave vector notation over the notations used by Belov et al. and Opechowski et al. are pointed out. In a one-dimensional real representation a space group element (α/tau(1)) has either the character +1 (symmetry element) or -1 (antisymmetry element). Thus the square of any space group operation must have the character +1 in a one-dimensional real representation. This simple ''square criterion'' is used to limit the admissible k-vectors and to derive the family of magnetic space groups, i.e. the set of all possible magnetic space groups, belonging to the same crystallographic space group. In the discussion some useful side results are obtained. Not only the real one-dimensional representations of point groups are connected to real one-dimensional representations of space groups, but a direct connection is shown to exist between one-dimensional complex representations of the point groups 3, 4 and 6 and one-dimensional real representations, belonging to P[001/2]=Psub(2c)(Psub(c))-lattices with screw axes 3 1 , 3 2 , 4 2 , 6 2 and 6 4 . Rules are derived for finding the Belov symbol when the Opechowski-Guccione symbol of the magnetic space group is known and this opportunity is used for correcting errors in the Opechowski-Guccione tables [fr

Reversible electrical-field control of magnetization and anomalous Hall effect in Co/PMN-PT hybrid heterostructures

Science.gov (United States)

Wang, J.; Huang, Q. K.; Lu, S. Y.; Tian, Y. F.; Chen, Y. X.; Bai, L. H.; Dai, Y.; Yan, S. S.

2018-04-01

Room-temperature reversible electrical-field control of the magnetization and the anomalous Hall effect was reported in hybrid multiferroic heterojunctions based on Co/Pb(Mg1/3Nb2/3)0.7Ti0.3O3 (PMN-PT). We demonstrate herein that electrical-field-induced strain and oxygen-ion migration in ZnO/Co/PMN-PT junctions exert opposing effects on the magnetic properties of the Co sublayer, and the competition between these effects determines the final magnitude of magnetization. This proof-of-concept investigation opens an alternative way to optimize and enhance the electrical-field effect on magnetism through the combination of multiple electrical manipulation mechanisms in hybrid multiferroic devices.

FERMI/LARGE AREA TELESCOPE DISCOVERY OF GAMMA-RAY EMISSION FROM A RELATIVISTIC JET IN THE NARROW-LINE QUASAR PMN J0948+0022

International Nuclear Information System (INIS)

Abdo, A. A.; Ackermann, M.; Ajello, M.; Bechtol, K.; Bloom, E. D.; Borgland, A. W.; Axelsson, M.; Battelino, M.; Baldini, L.; Bellazzini, R.; Bregeon, J.; Brez, A.; Ballet, J.; Barbiellini, G.; Bastieri, D.; Baughman, B. M.; Bonamente, E.; Brigida, M.; Caliandro, G. A.; Bruel, P.

2009-01-01

We report the discovery by the Large Area Telescope (LAT) onboard the Fermi Gamma-Ray Space Telescope of high-energy γ-ray emission from the peculiar quasar PMN J0948+0022 (z = 0.5846). The optical spectrum of this object exhibits rather narrow Hβ (FWHM(Hβ) ∼1500 km s -1 ), weak forbidden lines, and is therefore classified as a narrow-line type I quasar. This class of objects is thought to have relatively small black hole mass and to accrete at a high Eddington ratio. The radio loudness and variability of the compact radio core indicate the presence of a relativistic jet. Quasi-simultaneous radio/optical/X-ray and γ-ray observations are presented. Both radio and γ-ray emissions (observed over five months) are strongly variable. The simultaneous optical and X-ray data from Swift show a blue continuum attributed to the accretion disk and a hard X-ray spectrum attributed to the jet. The resulting broadband spectral energy distribution (SED) and, in particular, the γ-ray spectrum measured by Fermi are similar to those of more powerful Flat-Spectrum Radio Quasars (FSRQs). A comparison of the radio and γ-ray characteristics of PMN J0948+0022 with the other blazars detected by LAT shows that this source has a relatively low radio and γ-ray power with respect to other FSRQs. The physical parameters obtained from modeling the SED also fall at the low power end of the FSRQ parameter region discussed in Celotti and Ghisellini. We suggest that the similarity of the SED of PMN J0948+0022 to that of more massive and more powerful quasars can be understood in a scenario in which the SED properties depend on the Eddington ratio rather than on the absolute power.

Space groups for solid state scientists

CERN Document Server

Glazer, Michael; Glazer, Alexander N

2014-01-01

This Second Edition provides solid state scientists, who are not necessarily experts in crystallography, with an understandable and comprehensive guide to the new International Tables for Crystallography. The basic ideas of symmetry, lattices, point groups, and space groups are explained in a clear and detailed manner. Notation is introduced in a step-by-step way so that the reader is supplied with the tools necessary to derive and apply space group information. Of particular interest in this second edition are the discussions of space groups application to such timely topics as high-te

Electric-field tunable spin waves in PMN-PT/NiFe heterostructure: Experiment and micromagnetic simulations

Energy Technology Data Exchange (ETDEWEB)

Ziȩtek, Slawomir, E-mail: zietek@agh.edu.pl [AGH University of Science and Technology, Department of Electronics, Al. Mickiewicza 30, 30-059 Kraków (Poland); Chȩciński, Jakub [AGH University of Science and Technology, Department of Electronics, Al. Mickiewicza 30, 30-059 Kraków (Poland); AGH University of Science and Technology, Faculty of Physics and Applied Computer Science, Al. Mickiewicza 30, 30-059 Kraków (Poland); Frankowski, Marek; Skowroński, Witold; Stobiecki, Tomasz [AGH University of Science and Technology, Department of Electronics, Al. Mickiewicza 30, 30-059 Kraków (Poland)

2017-04-15

We present a comprehensive theoretical and experimental study of voltage-controlled standing spin waves resonance (SSWR) in PMN-PT/NiFe multiferroic heterostructures patterned into microstrips. A spin-diode technique was used to observe ferromagnetic resonance (FMR) mode and SSWR in NiFe strip mechanically coupled with a piezoelectric substrate. Application of an electric field to a PMN-PT creates a strain in permalloy and thus shifts the FMR and SSWR fields due to the magnetostriction effect. The experimental results are compared with micromagnetic simulations and a good agreement between them is found for dynamics of FMR and SSWR with and without electric field. Moreover, micromagnetic simulations enable us to discuss the amplitude and phase spatial distributions of FMR and SSWR modes, which are not directly observable by means of spin diode detection technique.

Surface acoustic load sensing using a face-shear PIN-PMN-PT single-crystal resonator.

Science.gov (United States)

Kim, Kyungrim; Zhang, Shujun; Jiang, Xiaoning

2012-11-01

Pb(In(0.5)Nb(0.5))O(3)-Pb(Mg(1/3)Nb(2/3))O(3)-PbTiO(3) (PIN-PMN-PT) resonators for surface acoustic load sensing are presented in this paper. Different acoustic loads are applied to thickness mode, thickness-shear mode, and face-shear mode resonators, and the electrical impedances at resonance and anti-resonance frequencies are recorded. More than one order of magnitude higher sensitivity (ratio of electrical impedance change to surface acoustic impedance change) at the resonance is achieved for the face-shear-mode resonator compared with other resonators with the same dimensions. The Krimholtz, Leedom, and Matthaei (KLM) model is used to verify the surface acoustic loading effect on the electrical impedance spectrum of face-shear PIN-PMN-PT single-crystal resonators. The demonstrated high sensitivity of face-shear mode resonators to surface loads is promising for a broad range of applications, including artificial skin, biological and chemical sensors, touch screens, and other touch-based sensors.

PMN-PT single crystal, high-frequency ultrasonic needle transducers for pulsed-wave Doppler application.

Science.gov (United States)

Zhou, Qifa; Xu, Xiaochen; Gottlieb, Emanuel J; Sun, Lei; Cannata, Jonathan M; Ameri, Hossein; Humayun, Mark S; Han, Pengdi; Shung, K Kirk

2007-03-01

High-frequency needle ultrasound transducers with an aperture size of 0.4 mm were fabricated using lead magnesium niobate-lead titanate (PMN-33% PT) as the active piezoelectric material. The active element was bonded to a conductive silver particle matching layer and a conductive epoxy backing through direct contact curing. An outer matching layer of parylene was formed by vapor deposition. The active element was housed within a polyimide tube and a 20-gauge needle housing. The magnitude and phase of the electrical impedance of the transducer were 47 omega and -38 degrees, respectively. The measured center frequency and -6 dB fractional bandwidth of the PMN-PT needle transducer were 44 MHz and 45%, respectively. The two-way insertion loss was approximately 15 dB. In vivo high-frequency, pulsed-wave Doppler patterns of blood flow in the posterior portion and in vitro ultrasonic backscatter microscope (UBM) images of the rabbit eye were obtained with the 44-MHz needle transducer.

Linear Thermal Expansion Measurements of Lead Magnesium Niobate (PMN) Electroceramic Material for the Terrestrial Planet Finder Coronagraph

Science.gov (United States)

Karlmann, Paul B.; Halverson, Peter G.; Peters, Robert D.; Levine, Marie B.; VanBuren, David; Dudik, Matthew J.

2005-01-01

Linear thermal expansion measurements of nine samples of Lead Magnesium Niobate (PMN) electroceramic material were recently performed in support of NASA's Terrestrial Planet Finder Coronagraph (TPF-C) mission. The TPF-C mission is a visible light coronagraph designed to look at roughly 50 stars pre- selected as good candidates for possessing earth-like planets. Upon detection of an earth-like planet, TPF-C will analyze the visible-light signature of the planet's atmosphere for specific spectroscopic indicators that life may exist there. With this focus, the project's primary interest in PMN material is for use as a solid-state actuator for deformable mirrors or compensating optics. The nine test samples were machined from three distinct boules of PMN ceramic manufactured by Xinetics Inc. Thermal expansion measurements were performed in 2005 at NASA Jet Propulsion Laboratory (JPL) in their Cryogenic Dilatometer Facility. All measurements were performed in vacuum with sample temperature actively controlled over the range of 270K to 3 10K. Expansion and contraction of the test samples with temperature was measured using a JPL developed interferometric system capable of sub-nanometer accuracy. Presented in this paper is a discussion of the sample configuration, test facilities, test method, data analysis, test results, and future plans.

Holomorphic representation of constant mean curvature surfaces in Minkowski space: Consequences of non-compactness in loop group methods

DEFF Research Database (Denmark)

Brander, David; Rossman, Wayne; Schmitt, Nicholas

2010-01-01

We give an infinite dimensional generalized Weierstrass representation for spacelike constant mean curvature (CMC) surfaces in Minkowski 3-space $\\R^{2,1}$. The formulation is analogous to that given by Dorfmeister, Pedit and Wu for CMC surfaces in Euclidean space, replacing the group $SU_2$ with...

Air-Coupled Ultrasonic Receivers with High Electromechanical Coupling PMN-32%PT Strip-Like Piezoelectric Elements

Directory of Open Access Journals (Sweden)

Rymantas J. Kazys

2017-10-01

Full Text Available For improvement of the efficiency of air-coupled ultrasonic transducers PMN-32%PT piezoelectric crystals which possess very high piezoelectric properties may be used. The electromechanical coupling factor of such crystals for all main vibration modes such as the thickness extension and transverse extension modes is more than 0.9. Operation of ultrasonic transducers with such piezoelectric elements in transmitting and receiving modes is rather different. Therefore, for transmission and reception of ultrasonic signals, separate piezoelectric elements with different dimensions must be used. The objective of this research was development of novel air-coupled ultrasonic receivers with PMN-32%PT strip-like piezoelectric elements vibrating in a transverse-extension mode with electromechanically controlled operation and suitable for applications in ultrasonic arrays. Performance of piezoelectric receivers made of the PMN-32%PT strip-like elements vibrating in this mode may be efficiently controlled by selecting geometry of the electrodes covering side surfaces of the piezoelectric element. It is equivalent to introduction of electromechanical damping which does not require any additional backing element. For this purpose; we have proposed the continuous electrodes to divide into two pairs of electrodes. The one pair is used to pick up the electric signal; another one is exploited for electromechanical damping. Two types of electrodes may be used—rectangular or non-rectangular—with a gap between them directed at some angle, usually 45°. The frequency bandwidth is wider (up to 9 kHz in the case of non-rectangular electrodes. The strip-like acoustic matching element bonded to the tip of the PMN-32%PT crystal may significantly enhance the performance of the ultrasonic receiver. It was proposed to use for this purpose AIREX T10.110 rigid polymer foam, the acoustic impedance of which is close to the optimal value necessary for matching with air. It was

Mapping spaces and automorphism groups of toric noncommutative spaces

Science.gov (United States)

Barnes, Gwendolyn E.; Schenkel, Alexander; Szabo, Richard J.

2017-09-01

We develop a sheaf theory approach to toric noncommutative geometry which allows us to formalize the concept of mapping spaces between two toric noncommutative spaces. As an application, we study the `internalized' automorphism group of a toric noncommutative space and show that its Lie algebra has an elementary description in terms of braided derivations.

Space activity in the 21 st century forum at unispace III

Science.gov (United States)

Doetsch, Karl H.; Zhdanovich, Olga V.

2000-07-01

During the 21st Century, space activity will have a profound influence on life on Earth and on the development of society. Space activity will touch ever more firmly on the provision of the necessities and qualities of life and will accelerate the movement of nations towards the concept of the global village. A study by Prospective 2100, a group identifying major global trends for the next century, ranked space activity as one of the twelve most important factors for shaping the next century, alongside such items as education, ocean cities, the planetary garden, caring and sharing. The International Space University, ISU, the International Astronautical Federation, IAF, and Prospective 2100 joined forces to study in detail how this influence of space activity would be manifested in the next century. The one-day forum at UNISPACE III was one of a number of international, intercultural and interdisciplinary fora held during the past year to consider what would be the most appropriate space activity for the next century to meet the needs of humanity. The findings and recommendations of the forum are presented in this report.

NUSTAR, SWIFT, and GROND Observations of the Flaring MEV Blazar PMN J0641-0320

DEFF Research Database (Denmark)

Ajello, M.; Ghisellini, G.; Paliya, V. S.

2016-01-01

Area Telescope and subsequent follow-up observations with NuSTAR, Swift, and GROND of a new member of the MeV blazar family: PMN J0641-0320. Our optical spectroscopy provides confirmation that this is a flat-spectrum radio quasar located at a redshift of z = 1.196. Its very hard NuSTAR spectrum (power...

Shear piezoelectric coefficients of PZT, LiNbO3 and PMN-PT at cryogenic temperatures

International Nuclear Information System (INIS)

Bukhari, Syed; Islam, Md; Haziot, Ariel; Beamish, John

2014-01-01

Piezoelectric transducers are used to detect stress and to generate nanometer scale displacements but their piezoelectric coefficients decrease with temperature, limiting their performance in cryogenic applications. We have developed a capacitive technique and directly measured the temperature dependence of the shear coefficient d 15 for ceramic lead zirconium titanate (PZT), 41° X-cut lithium niobate (LiNbO 3 ) and single crystal lead magnesium niobium-lead titanate (PMN-PT). In PZT, d 15 decreases nearly linearly with temperature, dropping by factor of about 4 by 1.3 K. LiNbO3 has the smallest room temperature d15, but its value decreased by only 6% at the lowest temperatures. PMN-PT had the largest value of d15 at room temperature (2.9 × 10 −9 m/V, about 45 times larger than for LiNbO 3 ) but it decreased rapidly below 75 K; at 1.3 K, d 15 was only about 8% of its room temperature value

Space Nuclear Facility test capability at the Baikal-1 and IGR sites Semipalatinsk-21, Kazakhstan

Science.gov (United States)

Hill, T. J.; Stanley, M. L.; Martinell, J. S.

1993-01-01

The International Space Technology Assessment Program was established 1/19/92 to take advantage of the availability of Russian space technology and hardware. DOE had two delegations visit CIS and assess its space nuclear power and propulsion technologies. The visit coincided with the Conference on Nuclear Power Engineering in Space Nuclear Rocket Engines at Semipalatinsk-21 (Kurchatov, Kazakhstan) on Sept. 22-25, 1992. Reactor facilities assessed in Semipalatinski-21 included the IVG-1 reactor (a nuclear furnace, which has been modified and now called IVG-1M), the RA reactor, and the Impulse Graphite Reactor (IGR), the CIS version of TREAT. Although the reactor facilities are being maintained satisfactorily, the support infrastructure appears to be degrading. The group assessment is based on two half-day tours of the Baikals-1 test facility and a brief (2 hr) tour of IGR; because of limited time and the large size of the tour group, it was impossible to obtain answers to all prepared questions. Potential benefit is that CIS fuels and facilities may permit USA to conduct a lower priced space nuclear propulsion program while achieving higher performance capability faster, and immediate access to test facilities that cannot be available in this country for 5 years. Information needs to be obtained about available data acquisition capability, accuracy, frequency response, and number of channels. Potential areas of interest with broad application in the U.S. nuclear industry are listed.

Estudio de la adición de K+ y LiNbO3 en las propiedades finales del Relaxor PMN procesado por mezcla de polvos

Directory of Open Access Journals (Sweden)

Fernández, J. F.

2004-06-01

Full Text Available PMN ceramic relaxor has been investigated by several researchers and many aspects of this material, like powder morphology, phase decomposition, weight loss during sintering process, densification, between others, still are investigated. PMN powder preparation has been shown more efficient when synthesized by columbite route, however lead addition stage for the PMN powder synthesis remains problematical. Therefore, this work proposes a new association of methodologies, using columbite route and the hydroxide precipitation method. Through use of the powder mixture technique, which permitted to obtain good green and sintered densities, was possible to observe K+ y Li+ dopants reduce weight loss in sintering process and change significantly the dielectric properties. Addition of LiNbO3 seeds in conformation stage, which react in a distinct way as a function of the particle size, promotes the formation of differenced grains in the ceramic bulk. Consequently, very different dielectrics properties from conventional PMN ceramic were obtained.El relaxor cerámico PMN ha sido investigado por un gran número de investigadores en el transcurso del tiempo y muchos aspectos de este material, como la morfología de los polvos, descomposición de fases, pérdida de peso en el proceso de sinterización, densificación, entre otras, siguen siendo objetos de investigación. La preparación de polvos de PMN se ha mostrado más efectiva cuando son sintetizados por la ruta de la columbita, pero la etapa de adición de plomo para la síntesis de polvos de PMN todavía sigue problemática. Por lo tanto, este trabajo propone una nueva asociación de metodologías, utilizando la ruta de la columbita y el método de precipitación por hidróxidos. Mediante la utilización de una técnica de mezcla de polvos, la cual permitió lograr buenas densidades en verde y sinterizadas, fue posible observar que los dopantes K+ y Li+ reducen las pérdidas de peso en el proceso de

Selenomethionine substitution of orotidine-5-monophosphate decarboxylase causes a change in crystal contacts and space group

DEFF Research Database (Denmark)

Poulsen, Jens-Christian Navarro; Harris, Pernille; Jensen, Kaj Frank

2001-01-01

with the inhibitor 1-(5'-phospho- -D-ribofuranosyl)barbituric acid crystallizes under similar conditions as the native enzyme. In contrast to the native enzyme, where the crystals belong to the orthorhombic space group P212121, the SeMet-substituted enzyme crystallizes in the monoclinic space group P21......-wavelength anomalous dispersion technique, both native and SeMet-substituted proteins have been produced and purified. During the production of SeMet ODCase, it was observed that SeMet was the only amino acid that it was necessary to add to the defined medium during expression. SeMet-substituted ODCase in complex...

Quantum group gauge theory on quantum spaces

International Nuclear Information System (INIS)

Brzezinski, T.; Majid, S.

1993-01-01

We construct quantum group-valued canonical connections on quantum homogeneous spaces, including a q-deformed Dirac monopole on the quantum sphere of Podles quantum differential coming from the 3-D calculus of Woronowicz on SU q (2). The construction is presented within the setting of a general theory of quantum principal bundles with quantum group (Hopf algebra) fiber, associated quantum vector bundles and connection one-forms. Both the base space (spacetime) and the total space are non-commutative algebras (quantum spaces). (orig.)

Canadian space agency discipline working group for space dosimetry and radiation science

International Nuclear Information System (INIS)

Waker, Anthony; Waller, Edward; Lewis, Brent; Bennett, Leslie; Conroy, Thomas

2008-01-01

Full text: One of the great technical challenges in the human and robotic exploration of space is the deleterious effect of radiation on humans and physical systems. The magnitude of this challenge is broadly understood in terms of the sources of radiation, however, a great deal remains to be done in the development of instrumentation, suitable for the space environment, which can provide real-time monitoring of the complex radiation fields encountered in space and a quantitative measure of potential biological risk. In order to meet these research requirements collaboration is needed between experimental nuclear instrumentation scientists, theoretical scientists working on numerical modeling techniques and radiation biologists. Under the auspices of the Canadian Space Agency such a collaborative body has been established as one of a number of Discipline Working Groups. Members of the Space Dosimetry and Radiation Science working group form a collaborative network across Canada including universities, government laboratories and the industrial sector. Three central activities form the core of the Space Dosimetry and Radiation Science DWG. An instrument sub-group is engaged in the development of instruments capable of gamma ray, energetic charged particle and neutron dosimetry including the ability to provide dosimetric information in real-time. A second sub-group is focused on computer modeling of space radiation fields in order to assess the performance of conceptual designs of detectors and dosimeters or the impact of radiation on cellular and sub-cellular biological targets and a third sub-group is engaged in the study of the biological effects of space radiation and the potential of biomarkers as a method of assessing radiation impact on humans. Many working group members are active in more than one sub-group facilitating communication throughout the whole network. A summary progress-report will be given of the activities of the Discipline Working Group and the

Sobolev Spaces on Locally Compact Abelian Groups: Compact Embeddings and Local Spaces

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Przemysław Górka

2014-01-01

Full Text Available We continue our research on Sobolev spaces on locally compact abelian (LCA groups motivated by our work on equations with infinitely many derivatives of interest for string theory and cosmology. In this paper, we focus on compact embedding results and we prove an analog for LCA groups of the classical Rellich lemma and of the Rellich-Kondrachov compactness theorem. Furthermore, we introduce Sobolev spaces on subsets of LCA groups and study its main properties, including the existence of compact embeddings into Lp-spaces.

Noncommutative phase spaces on Aristotle group

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Ancille Ngendakumana

2012-03-01

Full Text Available We realize noncommutative phase spaces as coadjoint orbits of extensions of the Aristotle group in a two dimensional space. Through these constructions the momenta of the phase spaces do not commute due to the presence of a naturally introduced magnetic eld. These cases correspond to the minimal coupling of the momentum with a magnetic potential.

Retabulation of space group extinctions for electron diffraction

International Nuclear Information System (INIS)

Goodman, P.; Tanaka, M.

1989-01-01

The space group tables previously published by one of the authors and others are here presented in a revised and compacted form designed to make for compatability with existing tables for X-ray diffraction. 136 of the 230 space groups are subject to dynamic extinctions due to glide planes and screw axes, and the observables from these space groups in specific settings are tabulated. Tabs

Group structure and group process for effective space station astronaut teams

Science.gov (United States)

Nicholas, J. M.; Kagan, R. S.

1985-01-01

Space Station crews will encounter new problems, many derived from the social interaction of groups working in space for extended durations. Solutions to these problems must focus on the structure of groups and the interaction of individuals. A model of intervention is proposed to address problems of interpersonal relationships and emotional stress, and improve the morale, cohesiveness, and productivity of astronaut teams.

Student Facebook groups as a third space

DEFF Research Database (Denmark)

Aaen, Janus Holst; Dalsgaard, Christian

2016-01-01

-institutional, personal space of the Facebook network. The main study of the article examines six student-managed Facebook groups and provides an analysis of a total of 2247 posts and 12,217 comments. Furthermore, the study draws on group interviews with students from 17 Danish upper secondary schools and a survey......The paper examines educational potentials of Facebook groups that are created and managed by students without any involvement from teachers. The objective is to study student-managed Facebook groups as a ‘third space' between the institutional space of teacher-managed Facebook groups and the non...... answered by 932 students from 25 schools. Based on the survey and interviews, the paper concludes that Facebook is an important educational tool for students in Danish upper secondary schools to receive help on homework and assignments. Furthermore, on the basis of the analysis of Facebook groups...

Hazy spaces, tangent spaces, manifolds and groups

International Nuclear Information System (INIS)

Dodson, C.T.J.

1977-03-01

The results on hazy spaces and the developments leading to hazy manifolds and groups are summarized. Proofs have appeared elsewhere so here examples are considered and some motivation for definitions and constructions in the theorems is analyzed. It is shown that quite simple ideas, intuitively acceptable, lead to remarkable similarity with the theory of differentiable manifolds. Hazy n manifolds have tangent bundles that are hazy 2n manifolds and there are hazy manifold structures for groups. Products and submanifolds are easily constructed and in particular the hazy n-sphere manifolds as submanifolds of the standard hazy manifold Zsup(n+1)

String cohomology groups of complex projective spaces

DEFF Research Database (Denmark)

Ottosen, Iver; Bökstedt, Marcel

2007-01-01

Let X be a space and write LX for its free loop space equipped with the action of the circle group T given by dilation. The equivariant cohomology H*(LXhT;Z/p) is a module over H*(BT;Z/p). We give a computation of this module when X=CPr for any positive integer r and any prime number p. The compu......Let X be a space and write LX for its free loop space equipped with the action of the circle group T given by dilation. The equivariant cohomology H*(LXhT;Z/p) is a module over H*(BT;Z/p). We give a computation of this module when X=CPr for any positive integer r and any prime number p...

Fabrication and comparison of PMN-PT single crystal, PZT and PZT-based 1-3 composite ultrasonic transducers for NDE applications.

Science.gov (United States)

Kim, Ki-Bok; Hsu, David K; Ahn, Bongyoung; Kim, Young-Gil; Barnard, Daniel J

2010-08-01

This paper describes fabrication and comparison of PMN-PT single crystal, PZT, and PZT-based 1-3 composite ultrasonic transducers for NDE applications. As a front matching layer between test material (Austenite stainless steel, SUS316) and piezoelectric materials, alumina ceramics was selected. The appropriate acoustic impedance of the backing materials for each transducer was determined based on the results of KLM model simulation. Prototype ultrasonic transducers with the center frequencies of approximately 2.25 and 5MHz for contact measurement were fabricated and compared to each other. The PMN-PT single crystal ultrasonic transducer shows considerably improved performance in sensitivity over the PZT and PZT-based 1-3 composite ultrasonic transducers. Copyright (c) 2010 Elsevier B.V. All rights reserved.

Second harmonic generation and dielectric study of the fine and coarse grain PMN-35PT ceramics

Czech Academy of Sciences Publication Activity Database

Kroupa, Jan; Bovtun, Viktor; Nuzhnyy, Dmitry; Savinov, Maxim; Vaněk, Přemysl; Kamba, Stanislav; Petzelt, Jan; Holc, J.; Kosec, M.; Amorin, H.; Alguero, M.

2008-01-01

Roč. 81, 11-12 (2008), s. 1059-1064 ISSN 0141-1594 R&D Projects: GA ČR(CZ) GA202/06/0403; GA MŠk OC 101 Institutional research plan: CEZ:AV0Z10100520 Keywords : relaxor ferroelectrics * phase transitions * PMN-PT * SHG * dielectric Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 1.201, year: 2008

A Phase Transformation with no Change in Space Group Symmetry: Octafluoronaphtalene

DEFF Research Database (Denmark)

Pawley, G. S.; Dietrich, O. W.

1975-01-01

A solid-state phase transformation in octafluoronaphthalene has been discovered at 266.5K on cooling, and at 15K higher on heating. The symmetry of both phases is found to be the same, namely monoclinic with space group P21/c. The unit cell parameters change by up to 10%, but the integrity...... of a single crystal, which shatters on cooling, is good enough for a single-crystal structure determination. This has been done in both phases to a sufficient accuracy that a mechanism for the transformation can be proposed. Molecules which lie parallel to one another shear to a new parallel position...

The International Space Life Sciences Strategic Planning Working Group

Science.gov (United States)

White, Ronald J.; Rabin, Robert; Lujan, Barbara F.

1993-01-01

Throughout the 1980s, ESA and the space agencies of Canada, Germany, France, Japan, and the U.S. have pursued cooperative projects bilaterally and multilaterally to prepare for, and to respond to, opportunities in space life sciences research previously unapproachable in scale and sophistication. To cope effectively with likely future space research opportunities, broad, multilateral, coordinated strategic planning is required. Thus, life scientists from these agencies have allied to form the International Space Life Sciences Strategic Planning Working Group. This Group is formally organized under a charter that specifies the purpose of the Working Group as the development of an international strategic plan for the space life sciences, with periodic revisions as needed to keep the plan current. The plan will be policy-, not operations-oriented. The Working Group also may establish specific implementation teams to coordinate multilateral science policy in specific areas; such teams have been established for space station utilization, and for sharing of flight equipment.

Space power technology for the twenty-first century (SPT21)

International Nuclear Information System (INIS)

Borger, W.U.; Massie, L.D.

1988-01-01

During the spring and summer months of 1987, the Aero Propulsion Laboratory of the Air Force Wright Aeronautical Laboratories, Wright-Patterson AFB, Ohio in cooperation with the Air Force Space Technology Center at Kirtland AFB, New Mexico, undertook an initiative to develop a Strategic Plan for Space Power Technology Development. The initiative was called SPT21, Space Power Technology for the Twenty-First Century. The planning process involved the participation of other Government organizations (U.S. Army, Navy, DOE and NASA) along with major aerospace companies and universities. Following an SPT21 kickoff meeting on 28 May 1987, detailed strategic planning was accomplished through seven (7) Space Power Technology Discipline Workshops commencing in June 1987 and concluding in August 1987. Technology Discipline Workshops were conducted in the following areas: (1) Solar Thermal Dynamic Power Systems (2) Solar Photovoltaic Cells and Arrays (3) Thermal Management Technology (4) Energy Storage Technology (5) Nuclear Power Systems Technology (6) Power Conditioning, Distribution and Control and (7) Systems Technology/Advanced Concepts. This technical paper summarizes the planning process and describes the salient findings and conclusions of the workshops

Estudio de PMN cerámico dopado con KNbO3 y LiNbO3 sintetizado por Pechini

Directory of Open Access Journals (Sweden)

Cilense, M.

2002-04-01

Full Text Available PMN belongs to a special class of materials named relaxor ferroelectrics. It has high volumetric efficiency due to its high dielectric constant, which makes it in a perfect material for application in multilayer capacitors. When prepared the columbite route its preparation has many advantages. In this work, the preparations of columbite and PMN were done by Pechini and Partial Oxalate methods, respectively. The effects of the KNbO3 and LiNbO3 dopants added in various concentrations. The idea is founded on the correlations that they have with BaTiO3 y PbTiO3, respectively. The whole process was supervised by TG/DTA, XRD, SEM and determination of the specific surface area of the powders. LiNbO3 carries out the pre-sinterization of the particles, observed by a reduction in the surface area. There are not particle grow, but occur its lengthening. However, for KNbO3 these particle growth, but the agglomerates are softer. The effect produced by the doping during the synthesis of the PMN powder is different from the one produced in the columbite precursor. Pure precursor shows an average particle size of 0,2μm, but the addition of 5,0mol% of dopants carries out the formation of agglomerates close to 4μm. LiNbO3 addition carries out spherical particles and pre-sinterization, while KNbO3 addition does not change the particles shape.El PMN pertenece a una clase especial de materiales conocido como ferroeléctricos relaxores. Posee gran eficacia volumétrica debido a su gran constante dieléctrica, siendo un perfecto candidato para la aplicación en capacitores multicapas. Su preparación es más ventajosa cuando se sintetiza por la ruta de la columbita. Las preparaciones de la columbita y del PMN se basaron en los métodos Pechini y Oxalato Parcial, respectivamente. Se ha estudiado los efectos de los dopantes KNbO3 y LiNbO3 añadidos a varias concentraciones. La idea esta basada en las correlaciones que estos tienen con BaTiO3 y PbTiO3, respectivamente

Mapping Spaces, Centralizers, and p-Local Finite Groups of Lie Type

DEFF Research Database (Denmark)

Laude, Isabelle

We study the space of maps from the classifying space of a finite p-group to theBorel construction of a finite group of Lie type G in characteristic p acting on itsbuilding. The first main result is a description of the homology with Fp-coefficients,showing that the mapping space, up to p...... between a finite p-group and theuncompleted classifying space of the p-local finite group coming from a finite groupof Lie type in characteristic p, providing some of the first results in this uncompletedsetting.......-completion, is a disjoint union indexedover the group homomorphism up to conjugation of classifying spaces of centralizersof p-subgroups in the underlying group G. We complement this description bydetermining the actual homotopy groups of the mapping space. These resultstranslate to descriptions of the space of maps...

NASA's Internal Space Weather Working Group

Science.gov (United States)

St. Cyr, O. C.; Guhathakurta, M.; Bell, H.; Niemeyer, L.; Allen, J.

2011-01-01

Measurements from many of NASA's scientific spacecraft are used routinely by space weather forecasters, both in the U.S. and internationally. ACE, SOHO (an ESA/NASA collaboration), STEREO, and SDO provide images and in situ measurements that are assimilated into models and cited in alerts and warnings. A number of years ago, the Space Weather laboratory was established at NASA-Goddard, along with the Community Coordinated Modeling Center. Within that organization, a space weather service center has begun issuing alerts for NASA's operational users. NASA's operational user community includes flight operations for human and robotic explorers; atmospheric drag concerns for low-Earth orbit; interplanetary navigation and communication; and the fleet of unmanned aerial vehicles, high altitude aircraft, and launch vehicles. Over the past three years we have identified internal stakeholders within NASA and formed a Working Group to better coordinate their expertise and their needs. In this presentation we will describe this activity and some of the challenges in forming a diverse working group.

Quantum groups and quantum homogeneous spaces

International Nuclear Information System (INIS)

Kulish, P.P.

1994-01-01

The usefulness of the R-matrix formalism and the reflection equations is demonstrated on examples of the quantum group covariant algebras (quantum homogeneous spaces): quantum Minkowski space-time, quantum sphere and super-sphere. The irreducible representations of some covariant algebras are constructed. The generalization of the reflection equation to super case is given and the existence of the quasiclassical limits is pointed out. (orig.)

HIF-1α is essential for effective PMN bacterial killing, antimicrobial peptide production and apoptosis in Pseudomonas aeruginosa keratitis.

Directory of Open Access Journals (Sweden)

Elizabeth A Berger

Full Text Available Hypoxia-inducible factor (HIF-1α, is a transcription factor that controls energy metabolism and angiogenesis under hypoxic conditions, and a potent regulator of innate immunity. The studies described herein examined the role of HIF-1α in disease resolution in BALB/c (resistant, cornea heals mice after ocular infection with Pseudomonas (P. aeruginosa. Furthermore, the current studies focused on the neutrophil (PMN, the predominant cell infiltrate in keratitis. Using both siRNA and an antagonist (17-DMAG, the role of HIF-1α was assessed in P. aeruginosa-infected BALB/c mice. Clinical score and slit lamp photography indicated HIF-1α inhibition exacerbated disease and corneal destruction. Real time RT-PCR, immunohistochemistry, ELISA, Greiss and MPO assays, bacterial load, intracellular killing, phagocytosis and apoptosis assays further tested the regulatory role of HIF-1α. Despite increased pro-inflammatory cytokine expression and increased MPO levels after knocking down HIF-1α expression, in vivo studies revealed a decrease in NO production and higher bacterial load. In vitro studies using PMN provided evidence that although inhibition of HIF-1α did not affect phagocytosis, both bacterial killing and apoptosis were significantly affected, as was production of antimicrobial peptides. Overall, data provide evidence that inhibition of HIF-1α converts a normally resistant disease response to susceptible (corneal thinning and perforation after induction of bacterial keratitis. Although this inhibition does not appear to affect PMN transmigration or phagocytosis, both in vivo and in vitro approaches indicate that the transcriptional factor is essential for effective bacterial killing, apoptosis and antimicrobial peptide production.

Space Interferometry Science Working Group

Science.gov (United States)

Ridgway, Stephen T.

1992-12-01

Decisions taken by the astronomy and astrophysics survey committee and the interferometry panel which lead to the formation of the Space Interferometry Science Working Group (SISWG) are outlined. The SISWG was formed by the NASA astrophysics division to provide scientific and technical input from the community in planning for space interferometry and in support of an Astrometric Interferometry Mission (AIM). The AIM program hopes to measure the positions of astronomical objects with a precision of a few millionths of an arcsecond. The SISWG science and technical teams are described and the outcomes of its first meeting are given.

Symmetries of quantum spaces. Subgroups and quotient spaces of quantum SU(2) and SO(3) groups

International Nuclear Information System (INIS)

Podles, P.

1995-01-01

We prove that each action of a compact matrix quantum group on a compact quantum space can be decomposed into irreducible representations of the group. We give the formula for the corresponding multiplicities in the case of the quotient quantum spaces. We describe the subgroups and the quotient spaces of quantum SU(2) and SO(3) groups. (orig.)

Chiral symmetry breaking and confinement in Minkowski space QED2+1

International Nuclear Information System (INIS)

Sauli, V.; Batiz, Z.

2010-01-01

Without any analytical assumption we solve the ladder QED2+1 in Minkowski space. Obtained complex fermion propagator exhibits confinement in the sense that it has no pole. Further, we transform Greens functions to the Temporal Euclidean space, wherein we show that in the special case of ladder QED2+1 the solution is fully equivalent to the Minkowski one. Obvious invalidity of Wick rotation is briefly discussed. The infrared value of the dynamical mass is compared with other known approaches, e. g. with the standard Euclidean calculation. We have presented for the first analysis of the electron gap equation in Minkowski and Temporal Euclidean space. The dynamical generation of imaginary part of the fermion mass leads to the absence of Khallen-Lehmann representation, providing thus confining solution for all value of m. Apart very small κ the real pole in the propagator is absent as well. Similarly to Euclidean QED3 Minkowski QED2+1 exhibits spontaneous chiral symmetry breaking the mass function has nontrivial solution in the limit m = 0, however the mass is complex function. Furthermore, we compare with QED solved in similar approximation in spacelike Euclidean and Temporal Euclidean space. As a interesting results, although based on the simple ladder approximation, is the proof of the exact equivalence between the theories defined in Minkowski 2+1 and 3D Temporal Euclidean space. We expect large quantitative changes when the polarization effect is taken account, especially the existence of critical number of flavors can be different when compared to the known Euclidean space estimates. Opposite to naive belief we showed and explained that the Wick rotation -the well known calculational trick in quantum theory- provides continuation of Schwinger function of the Euclidean theory which do not correspond with the Greens function calculated directly in the original Minkowski space. We can note our finding has a little to do with the know usefulness of various

Effects of dietary supplementation with eicosapentaenoic acid or gamma-linolenic acid on neutrophil phospholipid fatty acid composition and activation responses.

Science.gov (United States)

Fletcher, M P; Ziboh, V A

1990-10-01

Previous data that alimentation with fish oil rich in eicosapentaenoic acid (EPA; 20:n-3) or vegetable oil rich in gamma-linolenic acid (GLA; 18:3n-6) can reduce symptoms of inflammatory skin disorders lead us to determine the effects of dietary supplements of oils rich in EPA or GLA on guinea pig (GP) neutrophil (PMN) membrane potential (delta gamma), secretion, and superoxide (O2-) responses. Weanling GPs were initially fed diets supplemented with olive oil (less than 0.1% EPA; less than 0.1% GLA) for 2 weeks, followed by a crossover by two sets of animals to diets supplemented with fish oil (19% EPA) or borage oil (25% GLA). At 4-week intervals, 12% sterile casein-elicited peritoneal neutrophils (PMN) were assessed for membrane polyunsaturated fatty acid (PUFA) profiles and FMLP-, LTB4-, and PMA-stimulated delta gamma changes, changes in flow cytometrically measured forward scatter (FWD-SC) (shape change), 90 degrees scatter (90 degrees -SC) in cytochalasin B-pretreated-PMN (secretion response), and superoxide responses, GP incorporated EPA and GLA (as the elongation product, dihomo-GLA or DGLA) into their PMN phospholipids by 4 weeks. The peritoneal PMN of all groups demonstrated broad resting FWD-SC and poor activation-related FWD-SC increases, suggesting in vivo activation. While secretion was comparable in the three groups in response to FMLP, there was a trend toward inhibition of LTB4-stimulated 90 degrees -SC loss in both fish and borage oil groups. This was significant only with borage oil (21.7 +/- 2.1 vs 15.3 +/- 1.2% loss of baseline 90 degrees -SC, olive vs borage: P = 0.03). PMN from borage- and fish oil-fed GPs showed a progressively lower O2- response to FMLP than the olive oil group (73.9 +/- 3.9 and 42.9 +/- 6.8% of olive oil response for borage and fish oils, respectively; P less than 0.005 and P less than 0.01, respectively, at 12 weeks), while PMA-stimulated O2- was inhibited only in the fish oil-fed group and only at 12 weeks (62.0 +/- 2

Suppression of polymorphonuclear (PMN) and monocyte-mediated inhibition of Candida albicans growth by delta-9-tetrahydrocannabinol

International Nuclear Information System (INIS)

Djeu, J.Y.; Parapanios, A.; Halkias, D.; Friedman, H.

1986-01-01

This study was an in vitro attempt to identify the effector cells responsible for growth inhibition of the opportunistic fungus, candida albicans, and to determine if THC or another marijuana derivatives, 11-hydroxyTHC, would adversely affect their function. Using a 24h radiolabel assay, the authors found that growth inhibition of C. albicans was primarily mediated by PMN and monocytes that could be isolated normal human peripheral blood. Both effector cell types caused almost complete inhibition of Candida growth at effector/target ratio of 300/1 and inhibition was often still seen at 30/1-. Incubation of PMN, PBL, or monocytes for 1 hr at 37C with THC or 11-hydroxyTHC caused a marked suppression of function in all 3 cell populations. Maximal suppression was obtained with 7.5-10μg/ml of the drugs in medium containing 10% fetal bovine serum (FBS) or with 2-4μg/ml in 1% FBS. These drug concentrations did not affect lymphoid cell viability or candida growth in the absence of lymphoid effector cells. Marijuana derivatives, therefore, are doubly dangerous in that opportunistic fungi such as C. albicans can grow in their presence while the effector cells that control fungal growth are readily inactivated

Professional Discussion Groups: Informal Learning in a Third Space

Science.gov (United States)

Jordan, Robert A.

2013-01-01

In this ethnographic study, I explored two discussion groups and discovered Third Space elements such as cultural hybridity, counterscript, and sharing of experiences and resources contributed to a safe learning environment existing at the boundaries between participant personal and professional spaces. The groups operated under the auspices of a…

Group theoretical construction of planar noncommutative phase spaces

Energy Technology Data Exchange (ETDEWEB)

Ngendakumana, Ancille, E-mail: nancille@yahoo.fr; Todjihoundé, Leonard, E-mail: leonardt@imsp.uac.org [Institut de Mathématiques et des Sciences Physiques (IMSP), Porto-Novo (Benin); Nzotungicimpaye, Joachim, E-mail: kimpaye@kie.ac.rw [Kigali Institute of Education (KIE), Kigali (Rwanda)

2014-01-15

Noncommutative phase spaces are generated and classified in the framework of centrally extended anisotropic planar kinematical Lie groups as well as in the framework of noncentrally abelian extended planar absolute time Lie groups. Through these constructions the coordinates of the phase spaces do not commute due to the presence of naturally introduced fields giving rise to minimal couplings. By symplectic realizations methods, physical interpretations of generators coming from the obtained structures are given.

Group theoretical construction of planar noncommutative phase spaces

International Nuclear Information System (INIS)

Ngendakumana, Ancille; Todjihoundé, Leonard; Nzotungicimpaye, Joachim

2014-01-01

Noncommutative phase spaces are generated and classified in the framework of centrally extended anisotropic planar kinematical Lie groups as well as in the framework of noncentrally abelian extended planar absolute time Lie groups. Through these constructions the coordinates of the phase spaces do not commute due to the presence of naturally introduced fields giving rise to minimal couplings. By symplectic realizations methods, physical interpretations of generators coming from the obtained structures are given

Influence of piezoelectric strain on the Raman spectra of BiFeO{sub 3} films deposited on PMN-PT substrates

Energy Technology Data Exchange (ETDEWEB)

Himcinschi, Cameliu, E-mail: himcinsc@physik.tu-freiberg.de; Talkenberger, Andreas; Kortus, Jens [TU Bergakademie Freiberg, Institute of Theoretical Physics, 09596 Freiberg (Germany); Guo, Er-Jia [Institute of Physics, Martin-Luther-University Halle-Wittenberg, 06099 Halle (Germany); Institute for Metallic Materials, IFW Dresden, 01069 Dresden (Germany); Quantum Condensed Matter Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37830 (United States); Dörr, Kathrin [Institute of Physics, Martin-Luther-University Halle-Wittenberg, 06099 Halle (Germany); Institute for Metallic Materials, IFW Dresden, 01069 Dresden (Germany)

2016-01-25

BiFeO{sub 3} epitaxial thin films were deposited on piezoelectric 0.72Pb(Mg{sub 1/3}Nb{sub 2/3})O{sub 3}-0.28PbTiO{sub 3} (PMN-PT) substrates with a conductive buffer layer (La{sub 0.7}Sr{sub 0.3}MnO{sub 3} or SrRuO{sub 3}) using pulsed laser deposition. The calibration of the strain values induced by the electric field applied on the piezoelectric PMN-PT substrates was realised using X-Ray diffraction measurements. The method of piezoelectrically induced strain allows one to directly obtain a quantitative correlation between the strain and the shift of the Raman-active phonons. This is a prerequisite for making Raman scattering a strong tool to probe the strain coupling in multiferroic nanostructures. Using the Poisson's number for BiFeO{sub 3}, one can determine the volume change induced by strain, and therefore the Grüneisen parameters for specific phonon modes.

Performance of direct-driven flapping-wing actuator with piezoelectric single-crystal PIN-PMN-PT

Science.gov (United States)

Ozaki, Takashi; Hamaguchi, Kanae

2018-02-01

We present a prototype flapping-wing actuator with a direct-driven mechanism to generate lift in micro- and nano-aerial vehicles. This mechanism has an advantage of simplicity because it has no transmission system between the actuator and wing. We fabricated the piezoelectric unimorph actuator from single-crystal PIN-PMN-PT, which achieved a lift force up to 1.45 mN, a value about 1.9 times larger than the mass of the actuator itself. This is the first reported demonstration of an insect-scale actuator with a direct-driven mechanism that can generate a lift force greater than its own weight.

Optical Fiber Assemblies for Space Flight from the NASA Goddard Space Flight Center, Photonics Group

Science.gov (United States)

Ott, Melanie N.; Thoma, William Joe; LaRocca, Frank; Chuska, Richard; Switzer, Robert; Day, Lance

2009-01-01

The Photonics Group at NASA Goddard Space Flight Center in the Electrical Engineering Division of the Advanced Engineering and Technologies Directorate has been involved in the design, development, characterization, qualification, manufacturing, integration and anomaly analysis of optical fiber subsystems for over a decade. The group supports a variety of instrumentation across NASA and outside entities that build flight systems. Among the projects currently supported are: The Lunar Reconnaissance Orbiter, the Mars Science Laboratory, the James Webb Space Telescope, the Express Logistics Carrier for the International Space Station and the NASA Electronic Parts. and Packaging Program. A collection of the most pertinent information gathered during project support over the past year in regards to space flight performance of optical fiber components is presented here. The objective is to provide guidance for future space flight designs of instrumentation and communication systems.

Non-Supramenable Groups Acting on Locally Compact Spaces

DEFF Research Database (Denmark)

Kellerhals, Julian; Monod, Nicolas; Rørdam, Mikael

2013-01-01

Supramenability of groups is characterised in terms of invariant measures on locally compact spaces. This opens the door to constructing interesting crossed product $C^*$-algebras for non-supramenable groups. In particular, stable Kirchberg algebras in the UCT class are constructed using crossed ...

Electric field mediated non-volatile tuning magnetism in CoPt/PMN-PT heterostructure for magnetoelectric memory devices

Science.gov (United States)

Yang, Y. T.; Li, J.; Peng, X. L.; Wang, X. Q.; Wang, D. H.; Cao, Q. Q.; Du, Y. W.

2016-02-01

We report a power efficient non-volatile magnetoelectric memory in the CoPt/(011)PMN-PT heterostructure. Two reversible and stable electric field induced coercivity states (i.e., high-HC or low-HC) are obtained due to the strain mediated converse magnetoelectric effect. The reading process of the different coercive field information written by electric fields is demonstrated by using a magnetoresistance read head. This result shows good prospects in the application of novel multiferroic devices.

Poincare group and relativistic wave equations in 2+1 dimensions

Energy Technology Data Exchange (ETDEWEB)

Gitman, Dmitri M. [Instituto de Fisica, Universidade de Sao Paulo, Sao Paulo, SP (Brazil); Shelepin, A.L. [Moscow Institute of Radio Engenering, Electronics and Automation, Moscow (Russian Federation)

1997-09-07

Using the generalized regular representation, an explicit construction of the unitary irreducible representations of the (2+1)-Poincare group is presented. A detailed description of the angular momentum and spin in 2+1 dimensions is given. On this base the relativistic wave equations for all spins (including fractional) are constructed. (author)

Design Optimization for Interferometric Space-Based 21-cm Power Spectrum Measurements

Science.gov (United States)

Pober, Jonathan

2018-06-01

Observations of the highly-redshifted 21 cm hyperfine line of neutral hydrogen (HI) are one of the most promising probes for the future of cosmology. At redshifts z > 30, the HI signal is likely the only measurable emission, as luminous objects have yet to form. At these very low radio frequencies, however, the earth’s ionosphere becomes opaque — necessitating observations from space. The major challenge to neutral hydrogen cosmology (at all redshifts) lies in the presence of bright foreground emission, which can dominate the HI signal by as much as eight orders of magnitude at the highest redshifts. The only method for extracting the cosmological signal relies on the spectral smoothness of the foregrounds; since each frequency of the HI signal probes a different redshift, the cosmological emission is essentially uncorrelated from frequency to frequency. The key challenge for designing an experiment lies in maintaining the spectral smoothness of the foregrounds. If the frequency response of the instrument introduces spectral structure (or at least, a residual that cannot be calibrated out at the necessary precision), it quickly becomes impossible to distinguish the cosmological signal from the foregrounds. This principle has guided the design of ground-based experiments like the Precision Array for Probing the Epoch of Reionization (PAPER) and the Hydrogen Epoch of Reionization Array (HERA). However, there still exists no unifying framework for turning this design "philosophy" into a robust, quantitative set of performance metrics and specifications. In this talk, I will present updates on the efforts of my research group to translate lessons learned from ground-based experiments into a fully traceable set of mission requirements for Cosmic Dawn Mapper or other space-based 21 cm interferometer.

Voltage control of metal-insulator transition and non-volatile ferroelastic switching of resistance in VOx/PMN-PT heterostructures.

Science.gov (United States)

Nan, Tianxiang; Liu, Ming; Ren, Wei; Ye, Zuo-Guang; Sun, Nian X

2014-08-04

The central challenge in realizing electronics based on strongly correlated electronic states, or 'Mottronics', lies in finding an energy efficient way to switch between the distinct collective phases with a control voltage in a reversible and reproducible manner. In this work, we demonstrate that a voltage-impulse-induced ferroelastic domain switching in the (011)-oriented 0.71Pb(Mg1/3Nb2/3)O3-0.29PbTiO3 (PMN-PT) substrates allows a robust non-volatile tuning of the metal-insulator transition in the VOx films deposited onto them. In such a VOx/PMN-PT heterostructure, the unique two-step electric polarization switching covers up to 90% of the entire poled area and contributes to a homogeneous in-plane anisotropic biaxial strain, which, in turn, enables the lattice changes and results in the suppression of metal-insulator transition in the mechanically coupled VOx films by 6 K with a resistance change up to 40% over a broad range of temperature. These findings provide a framework for realizing in situ and non-volatile tuning of strain-sensitive order parameters in strongly correlated materials, and demonstrate great potentials in delivering reconfigurable, compactable, and energy-efficient electronic devices.

Multiwavelength Monitoring of the Enigmatic Narrow-Line Seyfert 1 PMN J0948 0022 in March-July 2009

Energy Technology Data Exchange (ETDEWEB)

Abdo, A.A.; /Naval Research Lab, Wash., D.C. /Federal City Coll.; Ackermann, M.; /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept.; Ajello, M.; /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept.; Axelsson, M.; /Stockholm U. /Stockholm U., OKC; Baldini, L.; /INFN, Pisa; Ballet, J.; /DAPNIA, Saclay; Barbiellini, G.; /INFN, Trieste /Trieste U.; Bastieri, D.; /INFN, Padua /Padua U.; Baughman, B.M.; /Ohio State U.; Bechtol, K.; /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept.; Bellazzini, R. /INFN, Pisa; Berenji, B.; /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept.; Bloom, E.D.; /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept.; Bonamente, E. /INFN, Perugia /Perugia U.; Borgland, A.W.; /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept.; Bregeon, J.; /INFN, Pisa; Brez, A.; /INFN, Pisa; Brigida, M.; /Bari U. /INFN, Bari; Bruel, P.; /Ecole Polytechnique; Burnett, T.H.; /Washington U., Seattle; Caliandro, G.A.; /Bari U. /INFN, Bari /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept. /IASF, Milan /Milan Polytechnic /DAPNIA, Saclay /ASDC, Frascati /INFN, Perugia /Perugia U. /NASA, Goddard /NASA, Goddard /CSST, Baltimore /SISSA, Trieste /Naval Research Lab, Wash., D.C. /George Mason U. /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept. /INFN, Perugia /Perugia U. /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept. /Montpellier U. /Garching, Max Planck Inst., MPE /Stockholm U. /Stockholm U., OKC /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept. /ASDC, Frascati /INFN, Trieste /Bari U. /INFN, Bari /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept. /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept. /CENBG, Gradignan /CENBG, Gradignan /Montpellier U. /Bari U. /INFN, Bari /Ecole Polytechnique /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept. /Ecole Polytechnique /Brera Observ. /INFN, Trieste /Bonn, Max Planck Inst., Radioastron. /Hiroshima U. /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept.; /more authors..

2012-03-29

Following the recent discovery of {gamma} rays from the radio-loud narrow-line Seyfert 1 galaxy PMN J0948+0022 (z = 0.5846), we started a multiwavelength campaign from radio to {gamma} rays, which was carried out between the end of 2009 March and the beginning of July. The source displayed activity at all the observed wavelengths: a general decreasing trend from optical to {gamma}-ray frequencies was followed by an increase of radio emission after less than two months from the peak of the {gamma}-ray emission. The largest flux change, about a factor of about 4, occurred in the X-ray band. The smallest was at ultraviolet and near-infrared frequencies, where the rate of the detected photons dropped by a factor 1.6-1.9. At optical wavelengths, where the sampling rate was the highest, it was possible to observe day scale variability, with flux variations up to a factor of about 3. The behavior of PMN J0948+0022 observed in this campaign and the calculated power carried out by its jet in the form of protons, electrons, radiation, and magnetic field are quite similar to that of blazars, specifically of flat-spectrum radio quasars. These results confirm the idea that radio-loud narrow-line Seyfert 1 galaxies host relativistic jets with power similar to that of average blazars.

MULTIWAVELENGTH MONITORING OF THE ENIGMATIC NARROW-LINE SEYFERT 1 PMN J0948+0022 IN 2009 MARCH-JULY

International Nuclear Information System (INIS)

Abdo, A. A.; Ackermann, M.; Ajello, M.; Bechtol, K.; Berenji, B.; Bloom, E. D.; Borgland, A. W.; Axelsson, M.; Baldini, L.; Bellazzini, R.; Bregeon, J.; Brez, A.; Ballet, J.; Barbiellini, G.; Bastieri, D.; Baughman, B. M.; Bonamente, E.; Brigida, M.; Bruel, P.; Burnett, T. H.

2009-01-01

Following the recent discovery of γ rays from the radio-loud narrow-line Seyfert 1 galaxy PMN J0948+0022 (z = 0.5846), we started a multiwavelength campaign from radio to γ rays, which was carried out between the end of 2009 March and the beginning of July. The source displayed activity at all the observed wavelengths: a general decreasing trend from optical to γ-ray frequencies was followed by an increase of radio emission after less than two months from the peak of the γ-ray emission. The largest flux change, about a factor of about 4, occurred in the X-ray band. The smallest was at ultraviolet and near-infrared frequencies, where the rate of the detected photons dropped by a factor 1.6-1.9. At optical wavelengths, where the sampling rate was the highest, it was possible to observe day scale variability, with flux variations up to a factor of about 3. The behavior of PMN J0948+0022 observed in this campaign and the calculated power carried out by its jet in the form of protons, electrons, radiation, and magnetic field are quite similar to that of blazars, specifically of flat-spectrum radio quasars. These results confirm the idea that radio-loud narrow-line Seyfert 1 galaxies host relativistic jets with power similar to that of average blazars.

Effects of oral administration of yam tuber storage protein, dioscorin, to BALB/c mice for 21-days on immune responses.

Science.gov (United States)

Liu, Yen-Wenn; Liu, Ju-Chi; Huang, Chun-Yao; Wang, Chung-Kwe; Shang, Huey-Fang; Hou, Wen-Chi

2009-10-14

Dioscorin, the tuber storage protein of yam, was reported to have immunomodulatory activity in RAW264.7 murine macrophage cell lines ( Food and Chemical Toxicology , 2007 , 45 , 2312 -2318 ). However, the immunomodulatory function of dioscorin after being ingested was not elucidated in vivo. Hence, BALB/c mice were given oral dioscorin (2.5 and 20 mg/kg/day) once a day for 21-days. Lymphocyte subpopulation changes in the peripheral blood and splenocytes, stimulation in phagocytosis of the polymorphonuclear cell (PMN) and monocytes, the natural killer (NK) cell cytotoxicity, the splenocyte proliferation, and cytokine secretions in the presence of PHA were determined. The number changes of Peyer's patches and secreted IgA (sIgA) in the feces were determined. Oral dioscorin for 21-days increased the subpopulation in natural killer cells (CD49(+)) and/or B cells (CD19(+)), elevated the phagocytosis of PMN (p dioscorin and significant difference to those of the control (p dioscorin exhibited systemic and mucosal immunomodulatory activities after being ingested in vivo.

The effect of supportive E. coli mastitis treatment on PMN chemiluminescence and subpopulations of T lymphocytes.

Science.gov (United States)

Markiewicz, H; Krumrych, W; Gehrke, M

2013-01-01

The aim of this field study was to assess the impact of a single i.m. injection of lysozyme dimer and flunixin meglumine in combination with intramammary and systemic antibiotic on chemiluminescence of PMN (polymorphonuclear leucocytes) and subpopulations of lymphocyte T in blood of cows with E. coli mastitis. Examinations were performed on 30 dairy cows affected with naturally occurring acute form of E. coli mastitis. Cows were randomly divided into three groups according to the method of treatment. The first group was treated with approved intramammary antibiotic product, the same antibiotic in i.m. injection and one injection of flunixin meglumine on the first day of therapy. Next group was treated with the same antibiotic and additionally one injection of lysozyme dimer on the first day of therapy. The third one was treated only with an antibiotic and served as a control group. Blood samples were taken before treatment and on days 3 and 7. In samples haematology indices were determined, spontaneous and opsonised zymosan stimulated CL and PMA measurements were performed and the subpopulations of T lymphocyte (CD2(+), CD4(+), CD8(+)) were assayed in whole blood. There was no effect of the applied supportive treatment on the value of morphological blood indices. A significant influence of the time of sample collection on the level of CL and dynamics of lymphocytes T subpopulation was demonstrated. A single injection of flunixin meglumine or lysozyme dimer on the day of the beginning of treatment of E. coli mastitis, does not affect the level of neutrophil chemiluminescence and the percentage of T lymphocytes in the blood of mastitic cows in the analysed period of time.

The birth of NASA the work of the Space Task Group, America's first true space pioneers

CERN Document Server

von Ehrenfried, Dutch

2016-01-01

This is the story of the work of the original NASA space pioneers; men and women who were suddenly organized in 1958 from the then National Advisory Committee on Aeronautics (NACA) into the Space Task Group. A relatively small group, they developed the initial mission concept plans and procedures for the U. S. space program. Then they boldly built hardware and facilities to accomplish those missions. The group existed only three years before they were transferred to the Manned Spacecraft Center in Houston, Texas, in 1962, but their organization left a large mark on what would follow. Von Ehrenfried's personal experience with the STG at Langley uniquely positions him to describe the way the group was structured and how it reacted to the new demands of a post-Sputnik era. He artfully analyzes how the growing space program was managed and what techniques enabled it to develop so quickly from an operations perspective. The result is a fascinating window into history, amply backed up by first person documentation ...

The space shuttle payload planning working groups: Volume 9: Materials processing and space manufacturing

Science.gov (United States)

1973-01-01

The findings and recommendations of the Materials Processing and Space Manufacturing group of the space shuttle payload planning activity are presented. The effects of weightlessness on the levitation processes, mixture stability, and control over heat and mass transport in fluids are considered for investigation. The research and development projects include: (1) metallurgical processes, (2) electronic materials, (3) biological applications, and (4)nonmetallic materials and processes. Additional recommendations are provided concerning the allocation of payload space, acceptance of experiments for flight, flight qualification, and private use of the space shuttle.

Endometrial cytology as an indicator of subclinical endometritis of dairy cattle Holstein Friesian and Jersey breeds

Directory of Open Access Journals (Sweden)

Reátegui J

2016-12-01

Full Text Available In order to evaluate the presence of polymorphonuclear neutrophils (% PMN-N as an indicator of endometritis sub clinic in dairy cattle Holstein Friesian and Jersey breeds, by the method of endometrial cytology. 94 dairy cows were sampled, and were grouped by genotypic characteristics as: Group 1: 47 Holstein Friesian cows; Group 2: 47 Jersey cows, both between 21 and 56 days postpartum. It were evaluated: age, body condition, lactation number, number of birth, date of birth and days in milk to obtain the sample data were evaluated with a test of homogeneity based on statistical Chi square (p 0.05 was found in any of the variables studied, the% PMN-N reached a range between 0.4% and 4.4%, with an average of 2.2% still below the values indicating the present investigation reports the% PMN-N by genetic group both as multiparous or primiparous cows showed no significant differences between them. It has be concluded that the overall frequency for SE in different genotype cows did show statistically significant differences (p>0.05, however the presence of PMN-N as an indicator of subclinical endometritis in dairy cows of different genotype with 2 and 4 lactations showed differences statistically significant (p<0.05.

Projective unitary-antiunitary representations of the Shubnikov space groups

International Nuclear Information System (INIS)

Broek, P.M. van den.

1979-01-01

Some mathematical aspects of the symmetry of a physical system in quantum mechanics are examined with special emphasis on the symmetry groups of charged particles in crystalline solids, the Shuknikov space groups. (Auth.)

21 CFR 864.9185 - Blood grouping view box.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Blood grouping view box. 864.9185 Section 864.9185 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES HEMATOLOGY AND PATHOLOGY DEVICES Products Used In Establishments That Manufacture Blood...

HIF-1? Is Essential for Effective PMN Bacterial Killing, Antimicrobial Peptide Production and Apoptosis in Pseudomonas aeruginosa Keratitis

OpenAIRE

Berger, Elizabeth A.; McClellan, Sharon A.; Vistisen, Kerry S.; Hazlett, Linda D.

2013-01-01

Hypoxia-inducible factor (HIF)-1α, is a transcription factor that controls energy metabolism and angiogenesis under hypoxic conditions, and a potent regulator of innate immunity. The studies described herein examined the role of HIF-1α in disease resolution in BALB/c (resistant, cornea heals) mice after ocular infection with Pseudomonas (P.) aeruginosa. Furthermore, the current studies focused on the neutrophil (PMN), the predominant cell infiltrate in keratitis. Using both siRNA and an antag...

Elon Musk, founder of SpaceX and PayPal, to speak on campus Feb. 21

OpenAIRE

Crumbley, Liz

2006-01-01

Elon Musk, founder and chief executive officer of Space Exploration Technologies Co. (SpaceX), will speak on his company's Falcon rocket series and the future of university space research on Tuesday, Feb. 21 at 7:30 p.m. in Virginia Tech's Burruss Hall Auditorium. The event is free and open to the public.

A summary of activities of the US/Soviet-Russian joint working group on space biology and medicine

Science.gov (United States)

Doarn, Charles R.; Nicogossian, Arnauld E.; Grigoriev, Anatoly I.; Tverskaya, Galina; Orlov, Oleg I.; Ilyin, Eugene A.; Souza, Kenneth A.

2010-10-01

The very foundation of cooperation between the United States (US) and Russia (former Soviet Union) in space exploration is a direct result of the mutual desire for scientific understanding and the creation of a collaborative mechanism—the Joint Working Group (JWG) on Space Biology and Medicine. From the dawn of the space age, it has been the quest of humankind to understand its place in the universe. While nations can and do solve problems independently, it takes nations, working together, to accomplish great things. The formation of the JWG provided an opportunity for the opening of a series of productive relationships between the superpowers, the US and the Union of Soviet Socialist Republics (USSR); and served as a justification for continued relationship for medical assistance in spaceflight, and to showcase Earth benefits from space medicine research. This relationship has been played out on an international scale with the construction and operation of the International Space Station. The fundamental reason for this successful endeavor is a direct result of the spirit and perseverance of the men and women who have worked diligently side-by-side to promote science and move our understanding of space forward. This manuscript provides a historical perspective of the JWG; how it came about; its evolution; what it accomplished; and what impact it has had and continues to have in the 21st century with regard to human spaceflight and space life sciences research. It captures the spirit of this group, which has been in continuous existence for over 40 years, and provides a never before reported summary of its activities.

21 CFR 864.9175 - Automated blood grouping and antibody test system.

Science.gov (United States)

2010-04-01

...) Identification. An automated blood grouping and antibody test system is a device used to group erythrocytes (red blood cells) and to detect antibodies to blood group antigens. (b) Classification. Class II (performance... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Automated blood grouping and antibody test system...

Student "Facebook" Groups as a Third Space: Between Social Life and Schoolwork

Science.gov (United States)

Aaen, Janus; Dalsgaard, Christian

2016-01-01

The paper examines educational potentials of "Facebook" groups that are created and managed by students without any involvement from teachers. The objective is to study student-managed "Facebook" groups as a "third space" between the institutional space of teacher-managed "Facebook" groups and the…

Critical role of non-muscle myosin light chain kinase in thrombin-induced endothelial cell inflammation and lung PMN infiltration.

Science.gov (United States)

Fazal, Fabeha; Bijli, Kaiser M; Murrill, Matthew; Leonard, Antony; Minhajuddin, Mohammad; Anwar, Khandaker N; Finkelstein, Jacob N; Watterson, D Martin; Rahman, Arshad

2013-01-01

The pathogenesis of acute lung injury (ALI) involves bidirectional cooperation and close interaction between inflammatory and coagulation pathways. A key molecule linking coagulation and inflammation is the procoagulant thrombin, a serine protease whose concentration is elevated in plasma and lavage fluids of patients with ALI and acute respiratory distress syndrome (ARDS). However, little is known about the mechanism by which thrombin contributes to lung inflammatory response. In this study, we developed a new mouse model that permits investigation of lung inflammation associated with intravascular coagulation. Using this mouse model and in vitro approaches, we addressed the role of non-muscle myosin light chain kinase (nmMLCK) in thrombin-induced endothelial cell (EC) inflammation and lung neutrophil (PMN) infiltration. Our in vitro experiments revealed a key role of nmMLCK in ICAM-1 expression by its ability to control nuclear translocation and transcriptional capacity of RelA/p65 in EC. When subjected to intraperitoneal thrombin challenge, wild type mice showed a marked increase in lung PMN infiltration via expression of ICAM-1. However, these responses were markedly attenuated in mice deficient in nmMLCK. These results provide mechanistic insight into lung inflammatory response associated with intravascular coagulation and identify nmMLCK as a critical target for modulation of lung inflammation.

Renormalization group in statistical physics - momentum and real spaces

International Nuclear Information System (INIS)

Yukalov, V.I.

1988-01-01

Two variants of the renormalization group approach in statistical physics are considered, the renormalization group in the momentum and the renormalization group in the real spaces. Common properties of these methods and their differences are cleared up. A simple model for investigating the crossover between different universality classes is suggested. 27 refs

Probing the Nanodomain Origin and Phase Transition Mechanisms in (Un)Poled PMN-PT Single Crystals and Textured Ceramics

Science.gov (United States)

Slodczyk, Aneta; Colomban, Philippe

2010-01-01

Outstanding electrical properties of solids are often due to the composition heterogeneity and/or the competition between two or more sublattices. This is true for superionic and superprotonic conductors and supraconductors, as well as for many ferroelectric materials. As in PLZT ferroelectric materials, the exceptional ferro- and piezoelectric properties of the PMN-PT ((1−x)PbMg1/3Nb2/3O3−xPbTiO3) solid solutions arise from the coexistence of different symmetries with long and short scales in the morphotropic phase boundary (MPB) region. This complex physical behavior requires the use of experimental techniques able to probe the local structure at the nanoregion scale. Since both Raman signature and thermal expansion behavior depend on the chemical bond anharmonicity, these techniques are very efficient to detect and then to analyze the subtitle structural modifications with an efficiency comparable to neutron scattering. Using the example of poled (field cooling or room temperature) and unpoled PMN-PT single crystal and textured ceramic, we show how the competition between the different sublattices with competing degrees of freedom, namely the Pb-Pb dominated by the Coulombian interactions and those built of covalent bonded entities (NbO6 and TiO6), determine the short range arrangement and the outstanding ferro- and piezoelectric properties. PMID:28883367

Groups, matrices, and vector spaces a group theoretic approach to linear algebra

CERN Document Server

Carrell, James B

2017-01-01

This unique text provides a geometric approach to group theory and linear algebra, bringing to light the interesting ways in which these subjects interact. Requiring few prerequisites beyond understanding the notion of a proof, the text aims to give students a strong foundation in both geometry and algebra. Starting with preliminaries (relations, elementary combinatorics, and induction), the book then proceeds to the core topics: the elements of the theory of groups and fields (Lagrange's Theorem, cosets, the complex numbers and the prime fields), matrix theory and matrix groups, determinants, vector spaces, linear mappings, eigentheory and diagonalization, Jordan decomposition and normal form, normal matrices, and quadratic forms. The final two chapters consist of a more intensive look at group theory, emphasizing orbit stabilizer methods, and an introduction to linear algebraic groups, which enriches the notion of a matrix group. Applications involving symm etry groups, determinants, linear coding theory ...

Depression Anxiety and Stress Scales (DASS-21): psychometric analysis across four racial groups.

Science.gov (United States)

Norton, Peter J

2007-09-01

Growing cross-cultural awareness has led researchers to examine frequently used research instruments and assessment tools in racially diverse populations. The present study was conducted to assess the psychometric characteristics of the 21-item version of the Depression, Anxiety, and Stress Scales (DASS-21) among different racial groups. The DASS-21 was chosen because it appears to be a reliable and easy to administer measure, ideal for both clinical and research purposes. Results suggest that the internal consistency, and convergent and divergent validity of the DASS-21 are similar across racial groups. Multigroup CFA, however, indicated that item loadings were invariant, while scale covariances were not invariant. This suggests that, although the items may load similarly on the depression, anxiety and stress constructs, these constructs may be differentially inter-related across groups. Implications for application in clinical practice are discussed.

System theory on group manifolds and coset spaces.

Science.gov (United States)

Brockett, R. W.

1972-01-01

The purpose of this paper is to study questions regarding controllability, observability, and realization theory for a particular class of systems for which the state space is a differentiable manifold which is simultaneously a group or, more generally, a coset space. We show that it is possible to give rather explicit expressions for the reachable set and the set of indistinguishable states in the case of autonomous systems. We also establish a type of state space isomorphism theorem. Our objective is to reduce all questions about the system to questions about Lie algebras generated from the coefficient matrices entering in the description of the system and in that way arrive at conditions which are easily visualized and tested.

Derivation of space groups in mm2, 222 and mmm crystal classes

International Nuclear Information System (INIS)

Nigam, G.D.

1987-08-01

An algebraic approach is developed to derive space groups using 4x4 Seitz matrices for the crystal classes mm2, 222 and mmm in the orthorhombic system. The advantage of the present method is that it is relatively simple and can be adapted to introduce space groups to beginners. One of the advantages of the present method is that it admits a geometrical visualization of the symmetry elements of space group. The method can easily be extended to other crystal classes in a straightforward way. 16 refs, 1 fig., 2 tabs

The influence of thermal stresses on the phase composition of 0.65Pb(Mg1/3Nb2/3)O3-0.35PbTiO3 thick films

Science.gov (United States)

Uršič, Hana; Zarnik, Marina Santo; Tellier, Jenny; Hrovat, Marko; Holc, Janez; Kosec, Marija

2011-01-01

The influence of thermal stresses versus the phase composition for 0.65Pb(Mg1/3Nb2/3)O3-0.35PbTiO3 (0.65PMN-0.35PT) thick films is being reported. The thermal residual stresses in the films have been calculated using the finite-element method. It has been observed that in 0.65PMN-0.35PT films a compressive stress enhances the thermodynamic stability of the tetragonal phase with the space group P4mm.

Analysis of Adult Female Mouse (Mus musculus) Group Behavior on the International Space Station (ISS)

Science.gov (United States)

Solomides, P.; Moyer, E. L.; Talyansky, Y.; Choi, S.; Gong, C.; Globus, R. K.; Ronca, A. E.

2016-01-01

As interest in long duration effects of space habitation increases, understanding the behavior of model organisms living within the habitats engineered to fly them is vital for designing, validating, and interpreting future spaceflight studies. A handful of papers have previously reported behavior of mice and rats in the weightless environment of space. The Rodent Research Hardware and Operations Validation (Rodent Research-1; RR1) utilized the Rodent Habitat (RH) developed at NASA Ames Research Center to fly mice on the ISS (International Space Station). Ten adult (16-week-old) female C57BL/6 mice were launched on September 21st, 2014 in an unmanned Dragon Capsule, and spent 37 days in microgravity. Here we report group behavioral phenotypes of the RR1 Flight (FLT) and environment-matched Ground Control (GC) mice in the Rodent Habitat (RH) during this long-duration flight. Video was recorded for 33 days on the ISS, permitting daily assessments of overall health and well-being of the mice, and providing a valuable repository for detailed behavioral analysis. We previously reported that, as compared to GC mice, RR1 FLT mice exhibited the same range of behaviors, including eating, drinking, exploration, self- and allo-grooming, and social interactions at similar or greater levels of occurrence. Overall activity was greater in FLT as compared to GC mice, with spontaneous ambulatory behavior, including organized 'circling' or 'race-tracking' behavior that emerged within the first few days of flight following a common developmental sequence, and comprised the primary dark cycle activity persisting throughout the remainder of the experiment. Participation by individual mice increased dramatically over the course of the flight. Here we present a detailed analysis of 'race-tracking' behavior in which we quantified: (1) Complete lap rotations by individual mice; (2) Numbers of collisions between circling mice; (3) Lap directionality; and (4) Recruitment of mice into a group

Johnson Space Center's Risk and Reliability Analysis Group 2008 Annual Report

Science.gov (United States)

Valentine, Mark; Boyer, Roger; Cross, Bob; Hamlin, Teri; Roelant, Henk; Stewart, Mike; Bigler, Mark; Winter, Scott; Reistle, Bruce; Heydorn,Dick

2009-01-01

The Johnson Space Center (JSC) Safety & Mission Assurance (S&MA) Directorate s Risk and Reliability Analysis Group provides both mathematical and engineering analysis expertise in the areas of Probabilistic Risk Assessment (PRA), Reliability and Maintainability (R&M) analysis, and data collection and analysis. The fundamental goal of this group is to provide National Aeronautics and Space Administration (NASA) decisionmakers with the necessary information to make informed decisions when evaluating personnel, flight hardware, and public safety concerns associated with current operating systems as well as with any future systems. The Analysis Group includes a staff of statistical and reliability experts with valuable backgrounds in the statistical, reliability, and engineering fields. This group includes JSC S&MA Analysis Branch personnel as well as S&MA support services contractors, such as Science Applications International Corporation (SAIC) and SoHaR. The Analysis Group s experience base includes nuclear power (both commercial and navy), manufacturing, Department of Defense, chemical, and shipping industries, as well as significant aerospace experience specifically in the Shuttle, International Space Station (ISS), and Constellation Programs. The Analysis Group partners with project and program offices, other NASA centers, NASA contractors, and universities to provide additional resources or information to the group when performing various analysis tasks. The JSC S&MA Analysis Group is recognized as a leader in risk and reliability analysis within the NASA community. Therefore, the Analysis Group is in high demand to help the Space Shuttle Program (SSP) continue to fly safely, assist in designing the next generation spacecraft for the Constellation Program (CxP), and promote advanced analytical techniques. The Analysis Section s tasks include teaching classes and instituting personnel qualification processes to enhance the professional abilities of our analysts

Differential calculus on quantum spaces and quantum groups

International Nuclear Information System (INIS)

Zumino, B.

1992-01-01

A review of recent developments in the quantum differential calculus. The quantum group GL q (n) is treated by considering it as a particular quantum space. Functions on SL q (n) are defined as a subclass of functions on GL q (n). The case of SO q (n) is also briefly considered. These notes cover part of a lecture given at the XIX International Conference on Group Theoretic Methods in Physics, Salamanca, Spain 1992

The crystallographic space groups and Heterotic string theory

International Nuclear Information System (INIS)

El Naschie, M.S.

2009-01-01

While the 17 planar crystallographic groups were shown to correspond to 17 two and three Stein spaces with a total dimension equal to DimE12=5α-bar o ≅685, the present work reveals that the corresponding 219 three dimensional groups leads to a total dimensionality equal to N o ≅8872 which happens to be the exact total number of massless states of the transfinite version of Heterotic super string spectrum.

The National Space Biomedical Research Institute's education and public outreach program: Working toward a global 21st century space exploration society

Science.gov (United States)

MacLeish, Marlene Y.; Thomson, William A.; Moreno, Nancy P.

2011-05-01

Space Exploration educators worldwide are confronting challenges and embracing opportunities to prepare students for the global 21st century workforce. The National Space Biomedical Research Institute (NSBRI), established in 1997 through a NASA competition, is a 12-university consortium dedicated to space life science research and education. NSBRI's Education and Public Outreach Program (EPOP) is advancing the Institute's mission by responding to global educational challenges through activities that: provide teacher professional development; develop curricula that teach students to communicate with their peers across the globe; provide women and minority US populations with greater access to, and awareness of science careers; and promote international science education partnerships. A recent National Research Council (NRC) Space Studies Board Report, America's Future in Space: Aligning the Civil Program with National Needs, acknowledges that "a capable workforce for the 21st century is a key strategic objective for the US space program… (and that) US problems requiring best efforts to understand and resolve…are global in nature and must be addressed through mutual worldwide action". [1] This sentiment has gained new momentum through a recent National Aeronautics and Space Administration (NASA) report, which recommends that the life of the International Space Station be extended beyond the planned 2016 termination. [2] The two principles of globalization and ISS utility have elevated NSBRI EPOP efforts to design and disseminate science, technology, engineering and mathematics (STEM) educational materials that prepare students for full participation in a globalized, high technology society; promote and provide teacher professional development; create research opportunities for women and underserved populations; and build international educational partnerships. This paper describes select EPOP projects and makes the case for using innovative, emerging information

Short communication: Evaluation of vaginal discharge following treatment with a progesterone insert.

Science.gov (United States)

Fischer-Tenhagen, C; von Krueger, X; Heuwieser, W

2012-08-01

Yellowish discharge after application of intravaginal progesterone releasing inserts is frequently observed in cows. The objective of this study was to compare the bacteriological contamination of the vagina and uterus before and after a treatment with a progesterone insert in heifers. Forty-two Holstein heifers received a progesterone releasing insert [Eazi-Breed controlled internal drug release (CIDR) insert; Pfizer Animal Health, Berlin, Germany] for 7d. The protruding tail had been removed from half of the inserts (no tail group: n=21; tail group: n=21). Nine heifers from the tail group lost the insert within the 7-d treatment interval and were excluded. Heifers identified in estrus were artificially inseminated on d 9 or 10. Vaginal discharge was scored on a 4-point scale [vaginal discharge score (VDS) 0 to 3] and vaginal swabs were taken for bacteriological examination on d 0 and 7 and the day of artificial insemination (AI). Furthermore, cytological and bacteriological samples were obtained from the uterus on d 7 and the day of AI. On d 0, coliforms and Streptococcus spp. were found in vaginal swabs of 21 heifers (64%). On d 7, all heifers showed purulent vaginal discharge (VDS 2 to 3). The VDS was higher in the tail group compared with the no tail group. Arcanobacterium pyogenes, coliforms, and Streptococcus spp. were isolated from the vaginal swabs in 32 of 33 (96%) heifers on d 7. On the day of AI, VDS had improved to 0 or 1 in 96% of the heifers. However, A. pyogenes, coliforms, and Streptococcus spp. were still isolated in 17 of 33 (53%) heifers from the vagina and in 32 of 33 (96%) heifers from the endometrium. Endometrial cytology revealed polymorphonuclear neutrophils (PMN) in 11 heifers (6 to 32% PMN). Five samples exceeded the threshold of 5% PMN, and 2 samples exceeded the 10% PMN threshold, indicative of subclinical endometritis. In conclusion, pyogenic bacteria were found in the vagina and uterus on d 7 and the day of AI after intravaginal

COSTANZA, 1-D 2 Group Space-Dependent Reactor Dynamics of Spatial Reactor with 1 Group Delayed Neutrons

International Nuclear Information System (INIS)

Agazzi, A.; Gavazzi, C.; Vincenti, E.; Monterosso, R.

1964-01-01

1 - Nature of physical problem solved: The programme studies the spatial dynamics of reactor TESI, in the two group and one space dimension approximation. Only one group of delayed neutrons is considered. The programme simulates the vertical movement of the control rods according to any given movement law. The programme calculates the evolution of the fluxes and temperature and precursor concentration in space and time during the power excursion. 2 - Restrictions on the complexity of the problem: The maximum number of lattice points is 100

Preparation and temperature dependence of electrostriction properties for PMN-based composite ceramics

International Nuclear Information System (INIS)

Zhao Jingbo; Qu Shaobo; Du Hongliang; Zheng Yanju; Xu Zhuo

2009-01-01

Both low- and high-temperature units were prepared by columbite precursor method, and Pb(Mg 1/3 Nb 2/3 )O 3 (PMN)-based ferroelectric composite ceramics were prepared by conventional method, baking-block method and coating method, respectively. The effects of preparation methods on dielectric and electrostriction properties as well as the temperature-dependence property of the obtained composite ceramics were studied. The results show that compared with the samples prepared by traditional blend sintering method, of the samples prepared by baking-block and coating methods have much better dielectric and electrostriction properties. For those prepared by baking-block method, the electrostriction temperature-dependence properties are good in the range of 20-60 deg. C. For those prepared by coating method, the dielectric temperature-dependence properties are also good in the broad range of -30 to 70 deg. C, and the electrostriction temperature properties are better than those prepared by blending-block. Compared with the traditional blending sintering method, the dielectric and electrostriction temperature-dependence properties are much better, which effectively solves the problem of temperature properties existing in present engineering applications.

MINUTE-SCALE RAPID VARIABILITY OF THE OPTICAL POLARIZATION IN THE NARROW-LINE SEYFERT 1 GALAXY PMN J0948+0022

Energy Technology Data Exchange (ETDEWEB)

Itoh, Ryosuke; Tanaka, Yasuyuki T.; Fukazawa, Yasushi; Kawaguchi, Kenji; Takaki, Katsutoshi; Ueno, Issei [Department of Physical Sciences, Hiroshima University, Higashi-Hiroshima, Hiroshima 739-8526 (Japan); Kawabata, Koji S.; Moritani, Yuki; Uemura, Makoto; Akitaya, Hiroshi; Yoshida, Michitoshi; Ohsugi, Takashi [Hiroshima Astrophysical Science Center, Hiroshima University, Higashi-Hiroshima, Hiroshima 739-8526 (Japan); Hanayama, Hidekazu; Miyaji, Takeshi [Ishigakijima Astronomical Observatory, National Astronomical Observatory of Japan, 1024-1 Arakawa, Ishigaki, Okinawa 907-0024 (Japan); Kawai, Nobuyuki, E-mail: itoh@hep01.hepl.hiroshima-u.ac.jp [Department of Physics, Tokyo Institute of Technology, 2-12-1 Ookayama, Meguro-ku, Tokyo 152-8551 (Japan)

2013-09-20

We report on optical photopolarimetric results of the radio-loud narrow-line Seyfert 1 (RL-NLSy1) galaxy PMN J0948+0022 on 2012 December to 2013 February triggered by flux enhancements in the near infrared and γ-ray bands. With the one-shot polarimetry of the Hiroshima One-shot Wide field Polarimeter installed on the Kanata Telescope, we detected very rapid variability in the polarized-flux (PF) light curve on MJD 56281 (2012 December 20). The rise and decay times were about 140 s and 180 s, respectively. The polarization degree (PD) reached 36% ± 3% at the peak of the short-duration pulse, while the polarization angle remained almost constant. In addition, temporal profiles of the total flux and PD showed highly variable but well correlated behavior and discrete correlation function analysis revealed that no significant time lag of more than 10 minutes was present. The high PD and minute-scale variability in PF provides clear evidence of synchrotron radiation from a very compact emission region of ∼10{sup 14} cm size with a highly ordered magnetic field. Such micro-variability of polarization is also observed in several blazar jets, but its complex relation between total flux and PD are explained by a multi-zone model in several blazars. The implied single emission region in PMN J0948+0022 might reflect a difference of jets between RL-NLSy1s and blazars.

Library Spaces for 21st-Century Learners: A Planning Guide for Creating New School Library Concepts

Science.gov (United States)

Sullivan, Margaret

2013-01-01

"Library Spaces for 21st-Century Learners: A Planning Guide for Creating New School Library Concepts" focuses on planning contemporary school library spaces with user-based design strategies. The book walks school librarians and administrators through the process of gathering information from students and other stakeholders involved in…

On the Chabauty space of locally compact abelian groups

OpenAIRE

Cornulier, Yves

2010-01-01

This paper contains several results about the Chabauty space of a general locally compact abelian group. Notably, we determine its topological dimension, we characterize when it is totally disconnected or connected; we characterize isolated points.

Micro-Raman study of the microheterogeneity in the MA-MC phase transition in 0.67PbMg1/3Nb2/3O3-0.33PbTiO3 single crystal

KAUST Repository

Yang, Y.

2011-04-20

Polarized Raman spectroscopy has been employed to investigate the evolution of the microstructure of 0.67PbMg1/3Nb2/3O3-0.33PbTiO3 (PMN-33%PT) single crystal in the temperature range from −195 to 300 °C. The M A-M C-cubic transition sequence was observed in the microareas with M A-type (space group Cm) and M C-type (space group Pm) monoclinic structures. Interestingly, the M A-M Cphase transition temperature exhibited remarkable microareal dependence due to the spatial inhomogeneity of polar nanoregions (PNRs). The M C-cubic phase transition took place at 155 °C in both microareas, which consisted well with previous reports. These results reveal that the phase transition in PMN-33%PT single crystal is closely related with the thermal dynamics of PNRs, which will be useful for understanding the microheterogeneity in this compound.

Toward a standardized structural-functional group connectome in MNI space.

Science.gov (United States)

Horn, Andreas; Blankenburg, Felix

2016-01-01

The analysis of the structural architecture of the human brain in terms of connectivity between its subregions has provided profound insights into its underlying functional organization and has coined the concept of the "connectome", a structural description of the elements forming the human brain and the connections among them. Here, as a proof of concept, we introduce a novel group connectome in standard space based on a large sample of 169 subjects from the Enhanced Nathan Kline Institute-Rockland Sample (eNKI-RS). Whole brain structural connectomes of each subject were estimated with a global tracking approach, and the resulting fiber tracts were warped into standard stereotactic (MNI) space using DARTEL. Employing this group connectome, the results of published tracking studies (i.e., the JHU white matter and Oxford thalamic connectivity atlas) could be largely reproduced directly within MNI space. In a second analysis, a study that examined structural connectivity between regions of a functional network, namely the default mode network, was reproduced. Voxel-wise structural centrality was then calculated and compared to others' findings. Furthermore, including additional resting-state fMRI data from the same subjects, structural and functional connectivity matrices between approximately forty thousand nodes of the brain were calculated. This was done to estimate structure-function agreement indices of voxel-wise whole brain connectivity. Taken together, the combination of a novel whole brain fiber tracking approach and an advanced normalization method led to a group connectome that allowed (at least heuristically) performing fiber tracking directly within MNI space. Such an approach may be used for various purposes like the analysis of structural connectivity and modeling experiments that aim at studying the structure-function relationship of the human connectome. Moreover, it may even represent a first step toward a standard DTI template of the human brain

Smile attractiveness related to buccal corridor space in 3 different facial types: A perception of 3 ethnic groups of Malaysians.

Science.gov (United States)

Nimbalkar, Smita; Oh, Yih Y; Mok, Reei Y; Tioh, Jing Y; Yew, Kai J; Patil, Pravinkumar G

2018-03-16

Buccal corridor space and its variations greatly influence smile attractiveness. Facial types are different for different ethnic populations, and so is smile attractiveness. The subjective perception of smile attractiveness of different populations may vary in regard to different buccal corridor spaces and facial patterns. The purpose of this study was to determine esthetic perceptions of the Malaysian population regarding the width of buccal corridor spaces and their effect on smile esthetics in individuals with short, normal, and long faces. The image of a smiling individual with a mesofacial face was modified to create 2 different facial types (brachyfacial and dolicofacial). Each face form was further modified into 5 different buccal corridors (2%, 10%, 15%, 22%, and 28%). The images were submitted to 3 different ethnic groups of evaluators (Chinese, Malay, Indian; 100 each), ranging between 17 and 21 years of age. A visual analog scale (50 mm in length) was used for assessment. The scores given to each image were compared with the Kruskal-Wallis test, and pairwise comparison was performed using the Mann-Whitney U test (α=.05). All 3 groups of evaluators could distinguish gradations of dark spaces in the buccal corridor at 2%, 10%, and 28%. Statistically significant differences were observed among 3 groups of evaluators in esthetic perception when pairwise comparisons were performed. A 15% buccal corridor was found to score esthetically equally within 3 face types by all 3 groups of evaluators. The Indian population was more critical in evaluation than the Chinese or Malay populations. In a pairwise comparison, more significant differences were found between long and short faces and the normal face; the normal face was compared with long and short faces separately. The width of the buccal corridor space influences smile attractiveness in different facial types. A medium buccal corridor (15%) is the esthetic characteristic preferred by all groups of evaluators

Interstellar scintillations of PSR B1919+21: space-ground interferometry

Science.gov (United States)

Shishov, V. I.; Smirnova, T. V.; Gwinn, C. R.; Andrianov, A. S.; Popov, M. V.; Rudnitskiy, A. G.; Soglasnov, V. A.

2017-07-01

We carried out observations of pulsar PSR B1919+21 at 324 MHz to study the distribution of interstellar plasma in the direction of this pulsar. We used the RadioAstron (RA) space radio telescope, together with two ground telescopes: Westerbork (WB) and Green Bank (GB). The maximum baseline projection for the space-ground interferometer was about 60 000 km. We show that interstellar scintillation of this pulsar consists of two components: diffractive scintillations from inhomogeneities in a layer of turbulent plasma at a distance z1 = 440 pc from the observer or homogeneously distributed scattering material to the pulsar; and weak scintillations from a screen located near the observer at z2 = 0.14 ± 0.05 pc. Furthermore, in the direction to the pulsar we detected a prism that deflects radiation, leading to a shift in observed source position. We show that the influence of the ionosphere can be ignored for the space-ground baseline. Analysis of the spatial coherence function for the space-ground baseline (RA-GB) yielded a scattering angle in the observer plane of θscat = 0.7 mas. An analysis of the time-frequency correlation function for weak scintillations yielded an angle of refraction in the direction to the pulsar θref, 0 = 110 ms and a distance to the prism zprism ≤ 2 pc.

An introduction to Lie groups and the geometry of homogeneous spaces

CERN Document Server

Arvanitoyeorgos, Andreas

2003-01-01

It is remarkable that so much about Lie groups could be packed into this small book. But after reading it, students will be well-prepared to continue with more advanced, graduate-level topics in differential geometry or the theory of Lie groups. The theory of Lie groups involves many areas of mathematics. In this book, Arvanitoyeorgos outlines enough of the prerequisites to get the reader started. He then chooses a path through this rich and diverse theory that aims for an understanding of the geometry of Lie groups and homogeneous spaces. In this way, he avoids the extra detail needed for a thorough discussion of other topics. Lie groups and homogeneous spaces are especially useful to study in geometry, as they provide excellent examples where quantities (such as curvature) are easier to compute. A good understanding of them provides lasting intuition, especially in differential geometry. The book is suitable for advanced undergraduates, graduate students, and research mathematicians interested in differenti...

Electric-regulated enhanced in-plane uniaxial anisotropy in FeGa/PMN-PT composite using oblique pulsed laser deposition

Science.gov (United States)

Zhang, Yi; Huang, Chaojuan; Turghun, Mutellip; Duan, Zhihua; Wang, Feifei; Shi, Wangzhou

2018-04-01

The FeGa film with in-plane uniaxial magnetic anisotropy was fabricated onto different oriented single-crystal lead magnesium niobate-lead titanate using oblique pulsed laser deposition. An enhanced in-plane uniaxial magnetic anisotropy field of FeGa film can be adjusted from 18 Oe to 275 Oe by tuning the oblique angle and polarizing voltage. The competitive relationship of shape anisotropy and strain anisotropy has been discussed, which was induced by oblique angle and polarizing voltage, respectively. The (100)-oriented and (110)-oriented PMN-PT show completely different characters on voltage-dependent magnetic properties, which could be attributed to various anisotropy directions depended on different strain directions.

Determining sociability, social space, and social presence in (a)synchronous collaborative groups.

Science.gov (United States)

Kreijns, Karel; Kirschner, Paul A; Jochems, Wim; Van Buuren, Hans

2004-04-01

The effectiveness of group learning in asynchronous distributed learning groups depends on the social interaction that takes place. This social interaction affects both cognitive and socioemotional processes that take place during learning, group forming, establishment of group structures, and group dynamics. Though now known to be important, this aspect is often ignored, denied or forgotten by educators and researchers who tend to concentrate on cognitive processes and on-task contexts. This "one-sided" educational focus largely determines the set of requirements in the design of computer-supported collaborative learning (CSCL) environments resulting in functional CSCL environments. In contrast, our research is aimed at the design and implementation of sociable CSCL environments which may increase the likelihood that a sound social space will emerge. We use a theoretical framework that is based upon an ecological approach to social interaction, centering on the concept of social affordances, the concept of the sociability of CSCL environments, and social presence theory. The hypothesis is that the higher the sociability, the more likely that social interaction will take place or will increase, and the more likely that this will result in an emerging sound social space. In the present research, the variables of interest are sociability, social space, and social presence. This study deals with the construction and validation of three instruments to determine sociability, social space, and social presence in (a)synchronous collaborating groups. The findings suggest that the instruments have potential to be useful as measures for the respective variables. However, it must be realized that these measures are "first steps."

Evaluation of 2.1μm DFB lasers for space applications

Science.gov (United States)

Barbero, J.; López, D.; Esquivias, I.; Tijero, J. M. G.; Fischer, M.; Roessner, K.; Koeth, J.; Zahir, M.

2017-11-01

This paper presents the results obtained in the frame of an ESA-funded project called "Screening and Preevaluation of Shortwave Infrared Laser Diode for Space Application" with the objective of verifying the maturity of state of the art SWIR DFB lasers at 2.1μm to be used for space applications (mainly based on the occultation measurement principle and spectroscopy). The paper focus on the functional and environmental evaluation test plan. It includes high precision characterization, mechanical test (vibration and SRS shocks), thermal cycling, gamma and proton radiation tests, life test and some details of the Destructive Physical Analysis performed. The electro-optical characterization includes measurements of the tuning capabilities of the laser both by current and by temperature, the wavelength stability and the optical power versus laser current.

Industrializing the near-earth asteroids: Speculations on human activities in space in the latter half of the 21st century

Science.gov (United States)

Sercel, Joel C.

1990-01-01

The use of solar system resources for human industry can be viewed as a natural extension of the continual growth of our species' habitat. Motivations for human activities in space can be discussed in terms of five distinct areas: (1) information processing and collection; (2) materials processing; (3) energy production to meet terrestrial power needs; (4) the use of extraterrestrial materials; and (5) disaster avoidance. When considering 21st-Century activities in space, each of these basic motivations must be treated in light of issues likely to be relevant to the 21st-Century earth. Many of the problems facing 21st-Century earth may stem from the need to maintain the world population of 8 to 10 billion people as is projected from expected growth rates. These problems are likely to include managing the impact of industrial processes on the terrestrial biosphere while providing adequate energy production and material goods for the growing population. The most important human activities in space in the latter half of the 21st Century may be associated with harnessing the resources of the near-earth asteroids for industrial processes. These above topics are discussed with an emphasis on space industrialization.

The homology groups of moduli spaces on non-classical Klein surfaces

International Nuclear Information System (INIS)

Zaw, Myint

2001-08-01

We describe the moduli space M-vector±(g,c) of non-classical directed Klein surfaces of genus g=h-c-1 with c≥0 distinguished points as a configuration space B ± (h,c) of classes h-slit pairs in C. Based on this model, we prove that M-vector ± (g,c) is non-orientable for any g and c and we compute the homology groups of the moduli spaces M-vector ± (g,c) for g≤2. (author)

Representation of SO(4,1) group and Hawking effect in the de-Sitter space

International Nuclear Information System (INIS)

Bogush, A.A.; Otchik, V.S.

1983-01-01

Expression relating the solution of the equation for particles with spin 1/2 to matrix elements of group SO(4, 1), is obtained. When using the relation of the Dirac equation solutions in the de Sitter space with matrix elements of representations of group SO(4, 1) the presence of the Hawking effect in the space is established. The de Sitter space is considered as 4-dimensional hyperboloid, inserted into 5-dimensional pseudo-Euclidean space. It is established, that the average number of emitted spinor particles obeys the Fermi-Dirac distribution

An unusual methylene aziridine refined in P2(1)/c and the nonstandard setting P2(1)/n.

Science.gov (United States)

Feast, George C; Haestier, James; Page, Lee W; Robertson, Jeremy; Thompson, Amber L; Watkin, David J

2009-12-01

The unusual methylene aziridine 6-tert-butyl-3-oxa-2-thia-1-azabicyclo[5.1.0]oct-6-ene 2,2-dioxide, C(9)H(15)NO(3)S, was found to crystallize with two molecules in the asymmetric unit. The structure was solved in both the approximately orthogonal and the oblique settings of space group No. 14, viz. P2(1)/n and P2(1)/c, respectively. A comparison of these results clearly displayed an increase in the correlation between coordinates in the ac plane for the oblique cell. The increase in the corresponding covariances makes a significant contribution to the standard uncertainties of derived parameters, e.g. bond lengths. Since there is yet no CIF definition for the full variance-covariance matrix, there are clear advantages to reporting the structure in the nonstandard space-group setting.

Impact of initial spacing on yield per acre and wood quality of unthinned loblolly pine at age 21

Science.gov (United States)

Alexander, III Clark; Richard F. Daniels; Lewis Jordan; Laurie Schimleck

2010-01-01

The market for southern pine first thinnings is soft. Thus, forest managers are planting at wider spacings, and using weed control and fertilization to grow chipping-saw and sawtimber trees in shorter rotations. A 21-year-old unthinned spacing study was sampled to determine the effect of initial spacing on wood quality and yield per acre of planted loblolly pine (

Influence of La in xPBBiN of ternary nanoceramic composite (1-x0.5PMN-0.5PZT-xPBBiN system by mechanic al activatio n technique for dielectric and piezoelectric properties

Directory of Open Access Journals (Sweden)

K. CHANDRAMOULI

2011-06-01

Full Text Available (1-x[0.5Pb(Mg0.33Nb0.67O3-0.5Pb(Zr0.53Ti0.47O3]-x[Pb0.557Ba0.38La0.022Bi0.02Nb2O6] with both perovskite and tungsten bronze structured composite have been synthesized through mechanical activation technique. The strong influence of lanthanum addition to the lead-barium-bismuth-niobate (xPBLBiN ceramics in perovskite structured (1-xPMN-PZT on structural and functional properties is confirmed. X-ray diffraction patterns studies showed that these complex composites consisted of perovskite Cubic with tungsten bronze Orthorhombic phases. La modification in PBBiN of a ternary system (1-xPMN-PZTxPBBiN revealed intensified orthorhombicity. As La increased the dielectric and piezoelectric properties tremendously increased in (1-xPMN-PZT-xPBLBiN nanoceramic composite. The optimum dielectric and piezoelectric properties (εRT = 2931, kp = 0.461 and d33 = 428 pC/N were found in x =0.4 composite. We achieved novel nanocomposites synthesized by high energy ball milling method and having binary structures in a single composite with excellent functional properties that can be used for energy harvesting applications.

Managing medical groups: 21st century challenges and the impact of physician leadership styles.

Science.gov (United States)

Martin, William E; Keogh, Timothy J

2004-01-01

Physician group managers and administrators charged with leading medical groups in the 21st century face a set of old and new challenges and opportunities. Leadership is assumed to make the difference between a successful and not-so-successful medical group. Yet, there is little research about how physician manager leadership styles contribute to the success of medical group practices. This article is a study of physician leadership styles using the DiSC, based upon a sample of 232 physician managers. Dominance (D) and conscientiousness (C) were the two dominant styles found in this study. Moreover, the two dominant combination leadership styles fall under the categories of the "creative" and the 'perfectionist." The article formulates practical recommendations for both physician managers and administrators for leading medical groups to respond more effectively to the challenges and opportunities facing medical groups in the 21st century.

Modelling redshift space distortion in the post-reionization H I 21-cm power spectrum

Science.gov (United States)

Sarkar, Debanjan; Bharadwaj, Somnath

2018-05-01

The post-reionization H I 21-cm signal is an excellent candidate for precision cosmology, this however requires accurate modelling of the expected signal. Sarkar et al. have simulated the real space H I 21-cm signal and have modelled the H I power spectrum as P_{{H I}}(k)=b^2 P(k), where P(k) is the dark matter power spectrum and b(k) is a (possibly complex) scale-dependent bias for which fitting formulas have been provided. This paper extends these simulations to incorporate redshift space distortion and predicts the expected redshift space H I 21-cm power spectrum P^s_{{H I}}(k_{\\perp },k_{allel }) using two different prescriptions for the H I distributions and peculiar velocities. We model P^s_{{H I}}(k_{\\perp },k_{allel }), assuming that it is the product of P_{{H I}}(k)=b^2 P(k) with a Kaiser enhancement term and a Finger of God (FoG) damping which has σp the pair velocity dispersion as a free parameter. Considering several possibilities for the bias and the damping profile, we find that the models with a scale-dependent bias and a Lorentzian damping profile best fit the simulated P^s_{{H I}}(k_{\\perp },k_{allel }) over the entire range 1 ≤ z ≤ 6. The best-fitting value of σp falls approximately as (1 + z)-m with m = 2 and 1.2, respectively, for the two different prescriptions. The model predictions are consistent with the simulations for k models underpredict P^s_2(k) at large k, and the fit is restricted to k < 0.15 Mpc-1.

Local Agenda 21 is not a group

DEFF Research Database (Denmark)

Hoffmann, Birgitte

1999-01-01

The article is a critical overview of the Danish approach to Local Agenda 21. It states Local Agenda 21 as a tool for the process of change.......The article is a critical overview of the Danish approach to Local Agenda 21. It states Local Agenda 21 as a tool for the process of change....

Evidence for anisotropic polar nanoregions in relaxor Pb(Mg1/3Nb2/3)O3: A neutron study of the elastic constants and anomalous TA phonon damping in PMN

Science.gov (United States)

Stock, C.; Gehring, P. M.; Hiraka, H.; Swainson, I.; Xu, Guangyong; Ye, Z.-G.; Luo, H.; Li, J.-F.; Viehland, D.

2012-09-01

We use neutron inelastic scattering to characterize the acoustic phonons in the relaxor Pb(Mg1/3Nb2/3)O3 (PMN) and demonstrate the presence of a highly anisotropic damping mechanism that is directly related to short-range polar correlations. For a large range of temperatures above Tc˜210 K, where dynamic, short-range polar correlations are present, acoustic phonons propagating along [11¯0] and polarized along [110] (TA2 phonons) are overdamped and softened across most of the Brillouin zone. By contrast, acoustic phonons propagating along [100] and polarized along [001] (TA1 phonons) are overdamped and softened for a more limited range of wave vectors q. The anisotropy and temperature dependence of the acoustic phonon energy linewidth Γ are directly correlated with neutron diffuse scattering cross section, indicating that polar nanoregions are the cause of the anomalous behavior. The damping and softening vanish for q→0, i.e., for long-wavelength acoustic phonons near the zone center, which supports the notion that the anomalous damping is a result of the coupling between the relaxational component of the diffuse scattering and the harmonic TA phonons. Therefore, these effects are not due to large changes in the elastic constants with temperature because the elastic constants correspond to the long-wavelength limit. We compare the elastic constants we measure to those from Brillouin scattering experiments and to values reported for pure PbTiO3. We show that while the values of C44 are quite similar, those for C11 and C12 are significantly less in PMN and result in a softening of (C11-C12) over PbTiO3. The elastic constants also show an increased elastic anisotropy [2C44/(C11-C12)] in PMN versus that in PbTiO3. These results are suggestive of an instability to TA2 acoustic fluctuations in PMN and other relaxor ferroelectrics. We discuss our results in the context of the current debate over the “waterfall” effect and show that they are inconsistent with

Working Group 2 summary: Space charge effects in bending systems

International Nuclear Information System (INIS)

Bohn, C.L.; Emma, P.J.

2000-01-01

At the start of the Workshop, the authors asked the Working Group 2 participants to concentrate on three basic goals: (1) survey the status of how comprehensively the physics concerning space-charge effects in bends is understood and how complete is the available ensemble of analytic and computational tools; (2) guided by data from experiments and operational experience, identify sources of, and cures for, beam degradation; and (3) review space-charge physics in rings and the limitations it introduces. As the Workshop unfolded, the third goal naturally folded into the other two goals, and these goals, they believe, were fulfilled in that the Working Group was able to compile an end product consisting of a set of recommendations for potentially fruitful future work. This summary constitutes an overview of the deliberations of the Working Group, and it is their hope that the summary clarifies the motivation for the recommended work listed at the end. The summary is organized according to the two aforementioned goals, and the prime topics of discussion appear as subsections under these goals

Challenges in Teaching Space Physics to Different Target Groups From Space Weather Forecasters to Heavy-weight Theorists

Science.gov (United States)

Koskinen, H. E.

2008-12-01

Plasma physics as the backbone of space physics is difficult and thus the space physics students need to have strong foundations in general physics, in particular in classical electrodynamics and thermodynamics, and master the basic mathematical tools for physicists. In many universities the number of students specializing in space physics at Master's and Doctoral levels is rather small and the students may have quite different preferences ranging from experimental approach to hard-core space plasma theory. This poses challenges in building up a study program that has both the variety and depth needed to motivate the best students to choose this field. At the University of Helsinki we require all beginning space physics students, regardless whether they enter the field as Master's or Doctoral degree students, to take a one-semester package consisting of plasma physics and its space applications. However, some compromises are necessary. For example, it is not at all clear, how thoroughly Landau damping should be taught at the first run or how deeply should the intricacies of collisionless reconnection be discussed. In both cases we have left the details to an optional course in advanced space physics, even with the risk that the student's appreciation of, e.g., reconnection may remain at the level of a magic wand. For learning experimental work, data analysis or computer simulations we have actively pursued arrangements for the Master's degree students to get a summer employments in active research groups, which usually lead to the Master's theses. All doctoral students are members of research groups and participate in experimental work, data analysis, simulation studies or theory development, or any combination of these. We emphasize strongly "learning by doing" all the way from the weekly home exercises during the lecture courses to the PhD theses which in Finland consist typically of 4-6 peer-reviewed articles with a comprehensive introductory part.

Real-space renormalization group approach to driven diffusive systems

Energy Technology Data Exchange (ETDEWEB)

Hanney, T [SUPA and School of Physics, University of Edinburgh, Mayfield Road, Edinburgh, EH9 3JZ (United Kingdom); Stinchcombe, R B [Theoretical Physics, 1 Keble Road, Oxford, OX1 3NP (United Kingdom)

2006-11-24

We introduce a real-space renormalization group procedure for driven diffusive systems which predicts both steady state and dynamic properties. We apply the method to the boundary driven asymmetric simple exclusion process and recover exact results for the steady state phase diagram, as well as the crossovers in the relaxation dynamics for each phase.

Real-space renormalization group approach to driven diffusive systems

International Nuclear Information System (INIS)

Hanney, T; Stinchcombe, R B

2006-01-01

We introduce a real-space renormalization group procedure for driven diffusive systems which predicts both steady state and dynamic properties. We apply the method to the boundary driven asymmetric simple exclusion process and recover exact results for the steady state phase diagram, as well as the crossovers in the relaxation dynamics for each phase

Generation of symmetry coordinates for crystals using multiplier representations of the space groups

DEFF Research Database (Denmark)

Hansen, Flemming Yssing

1978-01-01

Symmetry coordinates play an important role in the normal-mode calculations of crystals. It is therefore of great importance to have a general method, which may be applied for any crystal at any wave vector, to generate these. The multiplier representations of the space groups as given by Kovalev...... and the projection-operator technique provide a basis for such a method. The method is illustrated for the nonsymmorphic D36 space group, and the theoretical background for the representations of space groups in general is reviewed and illustrated on the example above. It is desirable to perform the projection...... of symmetry coordinates in such a way that they may be used for as many wave vectors as possible. We discuss how to achieve this goal. The detailed illustrations should make it simple to apply the theory in any other case....

A geometric renormalization group in discrete quantum space-time

International Nuclear Information System (INIS)

Requardt, Manfred

2003-01-01

We model quantum space-time on the Planck scale as dynamical networks of elementary relations or time dependent random graphs, the time dependence being an effect of the underlying dynamical network laws. We formulate a kind of geometric renormalization group on these (random) networks leading to a hierarchy of increasingly coarse-grained networks of overlapping lumps. We provide arguments that this process may generate a fixed limit phase, representing our continuous space-time on a mesoscopic or macroscopic scale, provided that the underlying discrete geometry is critical in a specific sense (geometric long range order). Our point of view is corroborated by a series of analytic and numerical results, which allow us to keep track of the geometric changes, taking place on the various scales of the resolution of space-time. Of particular conceptual importance are the notions of dimension of such random systems on the various scales and the notion of geometric criticality

Fundamental group of dual graphs and applications to quantum space time

International Nuclear Information System (INIS)

Nada, S.I.; Hamouda, E.H.

2009-01-01

Let G be a connected planar graph with n vertices and m edges. It is known that the fundamental group of G has 1 -(n - m) generators. In this paper, we show that if G is a self-dual graph, then its fundamental group has (n - 1) generators. We indicate that these results are relevant to quantum space time.

Validation of missed space-group symmetry in X-ray powder diffraction structures with dispersion-corrected density functional theory.

Science.gov (United States)

Hempler, Daniela; Schmidt, Martin U; van de Streek, Jacco

2017-08-01

More than 600 molecular crystal structures with correct, incorrect and uncertain space-group symmetry were energy-minimized with dispersion-corrected density functional theory (DFT-D, PBE-D3). For the purpose of determining the correct space-group symmetry the required tolerance on the atomic coordinates of all non-H atoms is established to be 0.2 Å. For 98.5% of 200 molecular crystal structures published with missed symmetry, the correct space group is identified; there are no false positives. Very small, very symmetrical molecules can end up in artificially high space groups upon energy minimization, although this is easily detected through visual inspection. If the space group of a crystal structure determined from powder diffraction data is ambiguous, energy minimization with DFT-D provides a fast and reliable method to select the correct space group.

The Picard group of the moduli space of r-Spin Riemann surfaces

DEFF Research Database (Denmark)

Randal-Williams, Oscar

2012-01-01

An r-Spin Riemann surface is a Riemann surface equipped with a choice of rth root of the (co)tangent bundle. We give a careful construction of the moduli space (orbifold) of r-Spin Riemann surfaces, and explain how to establish a Madsen–Weiss theorem for it. This allows us to prove the “Mumford...... conjecture” for these moduli spaces, but more interestingly allows us to compute their algebraic Picard groups (for g≥10, or g≥9 in the 2-Spin case). We give a complete description of these Picard groups, in terms of explicitly constructed line bundles....

A primer on Hilbert space theory linear spaces, topological spaces, metric spaces, normed spaces, and topological groups

CERN Document Server

Alabiso, Carlo

2015-01-01

This book is an introduction to the theory of Hilbert space, a fundamental tool for non-relativistic quantum mechanics. Linear, topological, metric, and normed spaces are all addressed in detail, in a rigorous but reader-friendly fashion. The rationale for an introduction to the theory of Hilbert space, rather than a detailed study of Hilbert space theory itself, resides in the very high mathematical difficulty of even the simplest physical case. Within an ordinary graduate course in physics there is insufficient time to cover the theory of Hilbert spaces and operators, as well as distribution theory, with sufficient mathematical rigor. Compromises must be found between full rigor and practical use of the instruments. The book is based on the author's lessons on functional analysis for graduate students in physics. It will equip the reader to approach Hilbert space and, subsequently, rigged Hilbert space, with a more practical attitude. With respect to the original lectures, the mathematical flavor in all sub...

Convergent-beam electron diffraction study of incommensurately modulated crystals. Pt. 2. (3 + 1)-dimensional space groups

International Nuclear Information System (INIS)

Terauchi, Masami; Takahashi, Mariko; Tanaka, Michiyoshi

1994-01-01

The convergent-beam electron diffraction (CBED) method for determining three-dimensional space groups is extended to the determination of the (3 + 1)-dimensional space groups for one-dimensional incommensurately modulated crystals. It is clarified than an approximate dynamical extinction line appears in the CBED discs of the reflections caused by an incommensurate modulation. The extinction enables the space-group determination of the (3 + 1)-dimensional crystals or the one-dimensional incommensurately modulated crystals. An example of the dynamical extinction line is shown using an incommensurately modulated crystal of Sr 2 Nb 2 O 7 . Tables of the dynamical extinction lines appearing in CBED patterns are given for all the (3 + 1)-dimensional space groups of the incommensurately modulated crystal. (orig.)

An introduction to data reduction: space-group determination, scaling and intensity statistics.

Science.gov (United States)

Evans, Philip R

2011-04-01

This paper presents an overview of how to run the CCP4 programs for data reduction (SCALA, POINTLESS and CTRUNCATE) through the CCP4 graphical interface ccp4i and points out some issues that need to be considered, together with a few examples. It covers determination of the point-group symmetry of the diffraction data (the Laue group), which is required for the subsequent scaling step, examination of systematic absences, which in many cases will allow inference of the space group, putting multiple data sets on a common indexing system when there are alternatives, the scaling step itself, which produces a large set of data-quality indicators, estimation of |F| from intensity and finally examination of intensity statistics to detect crystal pathologies such as twinning. An appendix outlines the scoring schemes used by the program POINTLESS to assign probabilities to possible Laue and space groups.

Ferroelectricity, Piezoelectricity, and Dielectricity of 0.06PMnN-0.94PZT(45/55 Thin Film on Silicon Substrate

Directory of Open Access Journals (Sweden)

Tao Zhang

2015-01-01

Full Text Available The high piezoelectricity and high quality factor ferroelectric thin films are important for electromechanical applications especially the micro electromechanical system (MEMS. The ternary compound ferroelectric thin films 0.06Pb(Mn1/3, Nb2/3O3 + 0.94Pb(Zr0.45, Ti0.55O3 (0.06PMnN-0.94PZT(45/55 were deposited on silicon(100 substrates by RF magnetron sputtering method considering that Mn and Nb doping will improve PZT properties in this research. For comparison, nondoped PZT(45/55 films were also deposited. The results show that both of thin films show polycrystal structures with the main (111 and (101 orientations. The transverse piezoelectric coefficients are e31,eff=−4.03 C/m2 and e31,eff=-3.5 C/m2, respectively. These thin films exhibit classical ferroelectricity, in which the coercive electric field intensities are 2Ec=147.31 kV/cm and 2Ec=135.44 kV/cm, and the saturation polarization Ps=30.86 μC/cm2 and Ps=17.74 μC/cm2, and the remnant polarization Pr=20.44 μC/cm2 and Pr=9.87 μC/cm2, respectively. Moreover, the dielectric constants and loss are εr=681 and D=5% and εr=537 and D=4.3%, respectively. In conclusion, 0.06PMnN-0.94PZT(45/55 thin films act better than nondoped films, even though their dielectric constants are higher. Their excellent ferroelectricity, piezoelectricity, and high power and energy storage property, especially the easy fabrication, integration realizable, and potentially high quality factor, make this kind of thin films available for the realistic applications.

Future In-Space Operations (FISO): A Working Group and Community Engagement

Science.gov (United States)

Thronson, Harley; Lester, Dan

2013-01-01

Long-duration human capabilities beyond low Earth orbit (LEO), either in support of or as an alternative to lunar surface operations, have been assessed at least since the late 1960s. Over the next few months, we will present short histories of concepts for long-duration, free-space human habitation beyond LEO from the end of the Apollo program to the Decadal Planning Team (DPT)/NASA Exploration Team (NExT), which was active in 1999 2000 (see Forging a vision: NASA s Decadal Planning Team and the origins of the Vision for Space Exploration , The Space Review, December 19, 2005). Here we summarize the brief existence of the Future In-Space Operations (FISO) working group in 2005 2006 and its successor, a telecon-based colloquium series, which we co-moderate.

Space-time versus world-sheet renormalization group equation in string theory

International Nuclear Information System (INIS)

Brustein, R.; Roland, K.

1991-05-01

We discuss the relation between space-time renormalization group equation for closed string field theory and world-sheet renormalization group equation for first-quantized strings. Restricting our attention to massless states we argue that there is a one-to-one correspondence between the fixed point solutions of the two renormalization group equations. In particular, we show how to extract the Fischler-Susskind mechanism from the string field theory equation in the case of the bosonic string. (orig.)

Direct crystallization of perovskite phase in PMN-PT thin films prepared by polyvinylpyrrolidone modified sol-gel processing and their properties

International Nuclear Information System (INIS)

Du, Z.H.; Zhang, T.S.; Zhu, M.M.; Ma, J.

2009-01-01

A modified sol-gel processing has been developed by using polyvinylpyrrolidone (PVP) as modifier and lead nitrate as lead source to synthesize (1-x)Pb(Mg 1/3 ,Nb 2/3 )O 3 -xPbTiO 3 (PMN-PT) thin films with x=0.23-0.43. With PVP additions, perovskite phase could directly crystallize from amorphous films at the temperature as low as 430 deg. C via bypassing the metastable phase-pyrochlore and crystallinity was significantly enhanced. The PVP addictives have been optimized with molecular weight 1/3 ,Nb 2/3 )O 3 -PbTiO 3 films via bypassing pyrochlore phase.

Linearized fermion-gravitation system in a (2+1)-dimensional space-time with Chern-Simons data

International Nuclear Information System (INIS)

Mello, E.R.B. de.

1990-01-01

The fermion-graviton system at linearized level in a (2+1)-dimensional space-time with the gravitational Chern-Simons term is studied. In this approximation it is shown that this system presents anomalous rotational properties and spin, in analogy with the gauge field-matter system. (A.C.A.S.) [pt

Production and testing of HENDL-2.1/CG coarse-group cross-section library based on ENDF/B-VII.0

International Nuclear Information System (INIS)

Xu Dezheng; He Zhaozhong; Zou Jun; Zeng Qin

2010-01-01

A coarse-group coupled neutron and photon (27n + 21γ) cross-section library HENDL-2.1/CG, based on ENDF/B-VII.0 evaluate data source, has been produced by FDS Team in Institute of Plasma Physics, Chinese Academy of Sciences (ASIPP). HENDL-2.1/CG containing 350 nuclide cross-section files (from 1 H to 252 Cf) was generated in MATXS format with the NJOY processing system and then by compiling coarse-group problem-dependent format using the TRANSX code. In order to verify the availability and reliability of the HENDL-2.1/CG data library, requisite benchmark calculations were performed and compared with HENDL-2.0/MG fine-group coupled neutron and photon (175n + 42γ) cross-section library. In general, results using the coarse-group library showed similarly believable as fine-group library.

The Lp Spectrum of Locally Symmetric Spaces with Small Fundamental Group

International Nuclear Information System (INIS)

Weber, Andreas

2009-01-01

We determine the L p spectrum of the Laplace-Beltrami operator on certain complete locally symmetric spaces M whose universal covering X is a symmetric space of non-compact type with rank one. More precisely, we show that the L p spectra of M and X coincide if the fundamental group of M is small and if the injectivity radius of M is bounded away from zero. In the L 2 case, the restriction on the injectivity radius is not needed

Multiple-wavelength Variability and Quasi-periodic Oscillation of PMN J0948+0022

Energy Technology Data Exchange (ETDEWEB)

Zhang, Jin [Key Laboratory of Space Astronomy and Technology, National Astronomical Observatories, Chinese Academy of Sciences, Beijing 100012 (China); Zhang, Hai-Ming; Zhu, Yong-Kai; Lu, Rui-Jing; Liang, En-Wei [Guangxi Key Laboratory for Relativistic Astrophysics, Department of Physics, Guangxi University, Nanning 530004 (China); Yi, Ting-Feng [Department of Physics, Yunnan Normal University, Kunming 650500 (China); Yao, Su, E-mail: jinzhang@bao.ac.cn [Kavli Institute for Astronomy and Astrophysics, Peking University, Beijing 100871 (China)

2017-11-01

We present a comprehensive analysis of multiple-wavelength observational data of the first GeV-selected narrow-line Seyfert 1 galaxy PMN J0948+0022. We derive its light curves in the γ -ray and X-ray bands from the data observed with Fermi /LAT and Swift /XRT, and generate the optical and radio light curves by collecting the data from the literature. These light curves show significant flux variations. With the LAT data we show that this source is analogous to typical flat spectrum radio quasars in the L {sub γ} –Γ {sub γ} plane, where L {sub γ} and Γ {sub γ} are the luminosity and spectral index in the LAT energy band. The γ -ray flux is correlated with the V-band flux with a lag of ∼44 days, and a moderate quasi-periodic oscillation (QPO) with a periodicity of ∼490 days observed in the LAT light curve. A similar QPO signature is also found in the V-band light curve. The γ -ray flux is not correlated with the radio flux in 15 GHz, and no similar QPO signature is found at a confidence level of 95%. Possible mechanisms of the QPO are discussed. We propose that gravitational-wave observations in the future may clarify the current plausible models for the QPO.

Disintegration of positive isometric group representations on L^p-spaces

NARCIS (Netherlands)

Jeu, de M.F.E.; Rozendaal, J.

2017-01-01

Let G be a Polish locally compact group acting on a Polish space X" role="presentation">X with a G-invariant probability measure μ" role="presentation">μ. We factorize the integral with respect to μ" role="presentation">μ in terms of the integrals with respect to the ergodic measures on X, and show

Description of symmetry of magnetic structures by representations of space groups. [Tables, projecton operator methods

Energy Technology Data Exchange (ETDEWEB)

Sikora, W

1974-10-15

A description of magnetic structures based on the use of representations of space groups is given. Representations of the space groups were established for each compound on the basis of experimental data by the method of projection operators. The compounds contained in the list are collected according to crystal systems, alphabetically within each system. The description of each compound consists of the four parts. The first part contain the chemical symbol of the compound, the second its space group. The next part contains the chemical symbol of the magnetic atom and its positions in Wychoff notation with the number of equivalent positions in the crystal unit cell. The main description of a compound magnetic structure is given in the fourth part. It contains: K vector defined in the reciprocal space, the representation according to which a magnetic structure is transformed and the axial vector function S which describes the magnetic structure.

Mathematical aspects of molecular replacement. III. Properties of space groups preferred by proteins in the Protein Data Bank.

Science.gov (United States)

Chirikjian, G; Sajjadi, S; Toptygin, D; Yan, Y

2015-03-01

The main goal of molecular replacement in macromolecular crystallography is to find the appropriate rigid-body transformations that situate identical copies of model proteins in the crystallographic unit cell. The search for such transformations can be thought of as taking place in the coset space Γ\\G where Γ is the Sohncke group of the macromolecular crystal and G is the continuous group of rigid-body motions in Euclidean space. This paper, the third in a series, is concerned with viewing nonsymmorphic Γ in a new way. These space groups, rather than symmorphic ones, are the most common ones for protein crystals. Moreover, their properties impact the structure of the space Γ\\G. In particular, nonsymmorphic space groups contain both Bieberbach subgroups and symmorphic subgroups. A number of new theorems focusing on these subgroups are proven, and it is shown that these concepts are related to the preferences that proteins have for crystallizing in different space groups, as observed in the Protein Data Bank.

21 CFR 864.9160 - Blood group substances of nonhuman origin for in vitro diagnostic use.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Blood group substances of nonhuman origin for in... Used In Establishments That Manufacture Blood and Blood Products § 864.9160 Blood group substances of nonhuman origin for in vitro diagnostic use. (a) Identification. Blood group substances of nonhuman origin...

Group Analysis in FieldTrip of Time-Frequency Responses: A Pipeline for Reproducibility at Every Step of Processing, Going From Individual Sensor Space Representations to an Across-Group Source Space Representation

Directory of Open Access Journals (Sweden)

Lau M. Andersen

2018-05-01

Full Text Available An important aim of an analysis pipeline for magnetoencephalographic (MEG data is that it allows for the researcher spending maximal effort on making the statistical comparisons that will answer his or her questions. The example question being answered here is whether the so-called beta rebound differs between novel and repeated stimulations. Two analyses are presented: going from individual sensor space representations to, respectively, an across-group sensor space representation and an across-group source space representation. The data analyzed are neural responses to tactile stimulations of the right index finger in a group of 20 healthy participants acquired from an Elekta Neuromag System. The processing steps covered for the first analysis are MaxFiltering the raw data, defining, preprocessing and epoching the data, cleaning the data, finding and removing independent components related to eye blinks, eye movements and heart beats, calculating participants' individual evoked responses by averaging over epoched data and subsequently removing the average response from single epochs, calculating a time-frequency representation and baselining it with non-stimulation trials and finally calculating a grand average, an across-group sensor space representation. The second analysis starts from the grand average sensor space representation and after identification of the beta rebound the neural origin is imaged using beamformer source reconstruction. This analysis covers reading in co-registered magnetic resonance images, segmenting the data, creating a volume conductor, creating a forward model, cutting out MEG data of interest in the time and frequency domains, getting Fourier transforms and estimating source activity with a beamformer model where power is expressed relative to MEG data measured during periods of non-stimulation. Finally, morphing the source estimates onto a common template and performing group-level statistics on the data are

Studying the evolutionary relationships and phylogenetic trees of 21 groups of tRNA sequences based on complex networks.

Science.gov (United States)

Wei, Fangping; Chen, Bowen

2012-03-01

To find out the evolutionary relationships among different tRNA sequences of 21 amino acids, 22 networks are constructed. One is constructed from whole tRNAs, and the other 21 networks are constructed from the tRNAs which carry the same amino acids. A new method is proposed such that the alignment scores of any two amino acids groups are determined by the average degree and the average clustering coefficient of their networks. The anticodon feature of isolated tRNA and the phylogenetic trees of 21 group networks are discussed. We find that some isolated tRNA sequences in 21 networks still connect with other tRNAs outside their group, which reflects the fact that those tRNAs might evolve by intercrossing among these 21 groups. We also find that most anticodons among the same cluster are only one base different in the same sites when S ≥ 70, and they stay in the same rank in the ladder of evolutionary relationships. Those observations seem to agree on that some tRNAs might mutate from the same ancestor sequences based on point mutation mechanisms.

Lie groups and symmetric spaces in memory of F. I. Karpelevich

CERN Document Server

Gindikin, S G

2003-01-01

The book contains survey and research articles devoted mainly to geometry and harmonic analysis of symmetric spaces and to corresponding aspects of group representation theory. The volume is dedicated to the memory of Russian mathematician F. I. Karpelevich (1927-2000).

Charting the Parameter Space of the 21-cm Power Spectrum

Science.gov (United States)

Cohen, Aviad; Fialkov, Anastasia; Barkana, Rennan

2018-05-01

The high-redshift 21-cm signal of neutral hydrogen is expected to be observed within the next decade and will reveal epochs of cosmic evolution that have been previously inaccessible. Due to the lack of observations, many of the astrophysical processes that took place at early times are poorly constrained. In recent work we explored the astrophysical parameter space and the resulting large variety of possible global (sky-averaged) 21-cm signals. Here we extend our analysis to the fluctuations in the 21-cm signal, accounting for those introduced by density and velocity, Lyα radiation, X-ray heating, and ionization. While the radiation sources are usually highlighted, we find that in many cases the density fluctuations play a significant role at intermediate redshifts. Using both the power spectrum and its slope, we show that properties of high-redshift sources can be extracted from the observable features of the fluctuation pattern. For instance, the peak amplitude of ionization fluctuations can be used to estimate whether heating occurred early or late and, in the early case, to also deduce the cosmic mean ionized fraction at that time. The slope of the power spectrum has a more universal redshift evolution than the power spectrum itself and can thus be used more easily as a tracer of high-redshift astrophysics. Its peaks can be used, for example, to estimate the redshift of the Lyα coupling transition and the redshift of the heating transition (and the mean gas temperature at that time). We also show that a tight correlation is predicted between features of the power spectrum and of the global signal, potentially yielding important consistency checks.

Validation of missed space-group symmetry in X-ray powder diffraction structures with dispersion-corrected density functional theory

DEFF Research Database (Denmark)

Hempler, Daniela; Schmidt, Martin U.; Van De Streek, Jacco

2017-01-01

More than 600 molecular crystal structures with correct, incorrect and uncertain space-group symmetry were energy-minimized with dispersion-corrected density functional theory (DFT-D, PBE-D3). For the purpose of determining the correct space-group symmetry the required tolerance on the atomic...... with missed symmetry were investigated by dispersion-corrected density functional theory. In 98.5% of the cases the correct space group is found....

What happens to the pleural space affected by malignant effusion after bedside pleurodesis?

Science.gov (United States)

de Araujo, Pedro H X N; Terra, Ricardo M; da Silva Santos, Thiago; Chate, Rodrigo C; de Paiva, Antonio F L; Pêgo-Fernandes, Paulo M

2018-03-24

Evaluate radiological characteristics of postpleurodesis pleural space of patients with recurrent malignant pleural effusion(RMPE). Prospective cohort study including patients with RPME treated with bedside pleurodesis. We used CT scans to calculate pleural cavity volume immediately before pleurodesis(iCT) and 30 days after(CT30). Radiological evolution was calculated by the difference between pleural volumes on CT30 and iCT(Δvolume). We categorized initial pleural volume as small(space(≥500 mL) and Δvolume as positive(>254.49 mL), unchanged(≥-268.77-≤ 254.49 mL), or negative(space(62.06%) and 33 large(37.93%). Clinical failure occurred in 7.4% of small space group and in 24.6% of large(P = 0.051, OR4.0(CI:1.098-14.570)). In small space group, 27.77% evolved with positive, 66.66% with unchanged and 5.55% with negative Δvolume. In the large space group these numbers were respectively 21.21%, 27.27%, and 51.51%. There is significant variability on pleural space volume. However, pleural volume remains unchanged in many cases. Besides that, more than half patients with initial large space coursed with relevant reduction. Finally, patients with initial small space presented a greater chance of clinical success. © 2018 Wiley Periodicals, Inc.

Winter School on Operator Spaces, Noncommutative Probability and Quantum Groups

CERN Document Server

2017-01-01

Providing an introduction to current research topics in functional analysis and its applications to quantum physics, this book presents three lectures surveying recent progress and open problems.  A special focus is given to the role of symmetry in non-commutative probability, in the theory of quantum groups, and in quantum physics. The first lecture presents the close connection between distributional symmetries and independence properties. The second introduces many structures (graphs, C*-algebras, discrete groups) whose quantum symmetries are much richer than their classical symmetry groups, and describes the associated quantum symmetry groups. The last lecture shows how functional analytic and geometric ideas can be used to detect and to quantify entanglement in high dimensions.  The book will allow graduate students and young researchers to gain a better understanding of free probability, the theory of compact quantum groups, and applications of the theory of Banach spaces to quantum information. The l...

International Space Station Earth Observations Working Group

Science.gov (United States)

Stefanov, William L.; Oikawa, Koki

2015-01-01

The multilateral Earth Observations Working Group (EOWG) was chartered in May 2012 in order to improve coordination and collaboration of Earth observing payloads, research, and applications on the International Space Station (ISS). The EOWG derives its authority from the ISS Program Science Forum, and a NASA representative serves as a permanent co-chair. A rotating co-chair position can be occupied by any of the international partners, following concurrence by the other partners; a JAXA representative is the current co-chair. Primary functions of the EOWG include, 1) the exchange of information on plans for payloads, from science and application objectives to instrument development, data collection, distribution and research; 2) recognition and facilitation of opportunities for international collaboration in order to optimize benefits from different instruments; and 3) provide a formal ISS Program interface for collection and application of remotely sensed data collected in response to natural disasters through the International Charter, Space and Major Disasters. Recent examples of EOWG activities include coordination of bilateral data sharing protocols between NASA and TsNIIMash for use of crew time and instruments in support of ATV5 reentry imaging activities; discussion of continued use and support of the Nightpod camera mount system by NASA and ESA; and review and revision of international partner contributions on Earth observations to the ISS Program Benefits to Humanity publication.

Quantum group random walks in strongly correlated 2+1 D spin systems

International Nuclear Information System (INIS)

Protogenov, A.P.; Rostovtsev, Yu.V.; Verbus, V.A.

1994-06-01

We consider the temporal evolution of strong correlated degrees of freedom in 2+1 D spin systems using the Wilson operator eigenvalues as variables. It is shown that the quantum-group diffusion equation at deformation parameter q being the k-th root of unity has the polynomial solution of degree k. (author). 20 refs, 1 tab

Electromechanical properties of a textured ceramic material in the (1 - x)PMN- xPT system: Simulation based on the effective-medium method

Science.gov (United States)

Aleshin, V. I.; Raevskiĭ, I. P.; Sitalo, E. I.

2008-11-01

A complete set of dielectric, piezoelectric, and elastic parameters for the textured ceramic material 0.67PMN-0.33PT is calculated by the self-consistency method with due regard for the anisotropy and piezoelectric activity of the medium. It is shown that the best piezoelectric properties corresponding to those of a single crystal are observed for the ceramic material with a texture in which all crystallites are oriented parallel to the [001] direction of the parent perovskite cubic cell. The simplest models of the polarization of an untextured ceramic material with a random initial orientation of crystallites are considered. The results obtained are compared with experimental data.

Group quantization on configuration space: Gauge symmetries and linear fields

International Nuclear Information System (INIS)

Navarro, M.; Aldaya, V.; Calixto, M.

1997-01-01

A new, configuration-space picture of a formalism of group quantization, the GAQ formalism, is presented in the context of a previous algebraic generalization. This presentation serves to make a comprehensive discussion in which other extensions of the formalism, principally to incorporate gauge symmetries, are developed as well. Both images are combined in order to analyze, in a systematic manner and with complete generality, the case of linear fields (Abelian current groups). To illustrate these developments we particularize them for several fields and, in particular, we carry out the quantization of the Abelian Chern endash Simons models over an arbitrary closed surface in detail. copyright 1997 American Institute of Physics

Effect of mechanical vs dilute ethanol epithelial removal on keratocyte apoptosis and polymorphonuclear leukocyte migration.

Science.gov (United States)

Gurelik, G; Bilgihan, K; Sezer, C; Akyol, G; Hasanreisoglu, B

2002-03-01

To investigate keratocyte apoptosis and polymorphonuclear (PMN) cell infiltration to the corneal stroma after mechanical epithelial scraping and chemical de-epithelialization with 18% ethanol solution. Twelve New Zealand Albino rabbits (24 eyes) were randomly divided into three groups. Group A was the control group with no epithelial removal. Group B underwent a 7.5-mm mechanical epithelial removal with a blunt spatula. Group C underwent 7.5-mm chemical de-epithelialization with 18% ethanol-balanced salt solution. Corneas were stained with terminal deoxyribonucleotidyl transferase-mediated dUTP-digoxigenin nick-end labeling (TUNEL) assay after 24 h. Only nuclear staining in keratocytes was counted. Polymorphonuclear (PMN) leukocyte densities were also assessed by light microscopy. Mechanical de-epithelialization (group B) and chemical de-epithelialization with 18% ethanol (group C) showed no difference in keratocyte apoptosis compared with the control group. There was also no difference between groups B and C. Group B showed no difference in PMN leukocyte counts compared with the control group. But the number of PMN leukocytes observed in group C was significantly higher than those encountered in the corneas of the control group (P < 0.05) and group B (P < 0.05). Dilute alcohol induces more PMN cell infiltration when compared with mechanical de-epithelialization although there is no difference in the apoptosis rates.

Advanced Exploration Technologies: Micro and Nano Technologies Enabling Space Missions in the 21st Century

Science.gov (United States)

Krabach, Timothy

1998-01-01

Some of the many new and advanced exploration technologies which will enable space missions in the 21st century and specifically the Manned Mars Mission are explored in this presentation. Some of these are the system on a chip, the Computed-Tomography imaging Spectrometer, the digital camera on a chip, and other Micro Electro Mechanical Systems (MEMS) technology for space. Some of these MEMS are the silicon micromachined microgyroscope, a subliming solid micro-thruster, a micro-ion thruster, a silicon seismometer, a dewpoint microhygrometer, a micro laser doppler anemometer, and tunable diode laser (TDL) sensors. The advanced technology insertion is critical for NASA to decrease mass, volume, power and mission costs, and increase functionality, science potential and robustness.

Space Biology in the 21st century

Science.gov (United States)

Halstead, Thora W.; Krauss, Robert W.

1990-01-01

Space Biology is poised to make significant contributions to science in the next century. A carefully crafted, but largely ground-based, program in the United States has evolved major questions that require answers through experiments in space. Science, scientists, and the new long-term spacecrafts designed by NASA will be available for the first time to mount a serious Space Biology effort. The scientific challenge is of such importance that success will provide countless benefits to biologically dependent areas such as medicine, food, and commerce in the decades ahead. The international community is rapidly expanding its role in this field. The United States should generate the resources that will allow progress in Space Biology to match the recognized progress made in aeronautics and the other space sciences.

Irreducible quantum group modules with finite dimensional weight spaces

DEFF Research Database (Denmark)

Pedersen, Dennis Hasselstrøm

a finitely generated U q -module which has finite dimensional weight spaces and is a sum of those. Our approach follows the procedures used by S. Fernando and O. Mathieu to solve the corresponding problem for semisimple complex Lie algebra modules. To achieve this we have to overcome a number of obstacles...... not present in the classical case. In the process we also construct twisting functors rigerously for quantum group modules, study twisted Verma modules and show that these admit a Jantzen filtration with corresponding Jantzen sum formula....

CfDS attends the first meeting of the All-Party Parliamentary Astronomy and Space Environment Group

Science.gov (United States)

Mizon, B.

1999-06-01

This group first met on March 11th, 1999, as 'a forum for discussion to further parliamentary interest in astronomy and the space environment affecting terrestrial life and its climate; and to increase awareness of the social, political and philosophical implications of present and future space technologies connected with exploring and understanding the cosmos'. CfDS coordinator Bob Mizon attended the first meeting of the group.

The coadjoint orbit spaces of Diff(S1) and Teichmueller spaces

International Nuclear Information System (INIS)

Nag, S.; Verjovsky, A.

1989-09-01

Precisely two of the homogeneous spaces that appear as coadjoint orbits of the group of string reparametrizations (Diff (S 1 )) carry in a natural way the structure of infinite dimensional, holomorphically homogeneous complex analytic Kaehler manifolds. These are N = Diff (S 1 )/Rot (S 1 ) and M = Diff (S 1 )/Moeb (S 1 ). Note that N is a holomorphic disc fiber space over M. Now, M can be naturally considered as embedded in the classical universal Teichmueller space T(1), simply by noting that a diffeomorphism of S 1 is a quasisymmetric homeomorphism. T(1) is itself a homomorphically homogeneous complex Banach manifold. We prove in the first part of the paper that the inclusion of M in T(1) is complex analytic. In the latter portion of this paper it is shown that the unique homogeneous Kaehler metric carried by M = Diff (S 1 )/SL(2, R) induces precisely the Weil-Petersson metric on the Teichmueller space. This is via our identification of M as a holomorphic submanifold of universal Teichmueller space. Now recall that every Teichmueller space T(G) of finite or infinite dimension is contained canonically and holomorphically within T(1). Our computations allow us also to prove that every T(G), G any infinite Fuchsian group, projects out of M transversely. This last assertion is related to the ''fractal'' nature of G-invariant quasicircles, and to Mostow rigidity on the line. Our results thus connect the loop space approach to bosonic string theory with the sumover moduli (Polyakov path integral) approach. (author). 21 refs

14 CFR 33.21 - Engine cooling.

Science.gov (United States)

2010-01-01

... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Engine cooling. 33.21 Section 33.21 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: AIRCRAFT ENGINES Design and Construction; General § 33.21 Engine cooling. Engine design and...

The dual algebra of the Poincare group on Fock space

International Nuclear Information System (INIS)

Klink, W.H.; Iowa Univ., Iowa City, IA

1989-01-01

The Lie algebra of operators commuting with the Poincare group on the Fock space appropriate for a massive spinless particle is constructed in terms of raising and lowering operators indexed by a Lorentz invariant function. From the assumption that the phase operator is an element of this Lie algebra, it is shown that the scattering operator can be written as a unitary representation operator of the group associated with the Lie algebra. A simple choice of the phase operator shows that the Lorentz invariant function can be interpreted as a basic scattering amplitude, in the sense that all multiparticle scattering amplitudes can be written in terms of this basic scattering amplitude. (orig.)

Giant Electric Field Control of Magnetism and Narrow Ferromagnetic Resonance Linewidth in FeCoSiB/Si/SiO2/PMN PT Multiferroic Heterostructures (Open Access Author’s Manuscript)

Science.gov (United States)

2016-06-06

the widely used lead zirconate titanate ceramics which have a typical piezoelectric coefficient d31 of ~- 200pC/N, PMN-PT single crystals used in...substrate clamping effect, therefore, a relatively giant tunability can be obtained. However, the normally large roughness of piezoelectric layer...is the saturation magnetostriction constant, Y the Young’s modulus of the magnetic film, deff the effective piezoelectric coefficient, E

Estudio de la migración y de la actividad metabólica de los polimofonucleares neutrófilos en pacientes con periodontitis juvenil localizada Migration and metabolic activity of polymorphonuclear neutrophils in patients with localized juvenile periodontitis

Directory of Open Access Journals (Sweden)

Pablo Javier Patiño Grajales

1993-03-01

Full Text Available La periodontitis juvenil localizada (PJL se caracteriza por presentar una pérdida rápida de la inserción del tejido conectivo y el hueso alveolar alrededor de los primeros molares e incisivos de la dentición permanente. Esta Investigación se realizó para establecer una relación entre el comportamiento In vitro de los polimorfonucleares neutrófilos (PMN y los diferentes tipos clínicos de la enfermedad. Se estudiaron 21 pacientes con PJL clasificados en tres grupos: incipiente, moderada y avanzada. Antes de que los pacientes recibieran algún tipo de tratamiento odontológico, se les aislaron los neutrófilos y se estudió, In vitro, la quimiotaxis bajo agarosa y la actividad metabólica mediante la quimioluminiscencia dependiente de luminol (QLDL. Las mismas pruebas fueron practicadas en forma paralela a un grupo de individuos sanos como controles. Los pacientes con PJL avanzada tuvieron una disrninución significativa de la quimiotaxis (p=0.023. Su índice quimiotáctico fue de 9.4 :t 1.01 mientras el de los controles fue 11.9 :t 0.33. De otro lado, la QLDL de los PMN estimulados con forbol miristato acetato (PMA fue normal en todos los grupos, comparados con los controles; en contraste la estimulación de los PMN con zymosan opsonizado, evidenció una actividad metabólica significativamente disminuida en los pacientes con PJL incipiente y avanzada: el promedio de producción de energía lumínica en cpm para el grupo con PJL avanzada fue 703376:!: 74510 y para el de PJL incipiente fue 737000:!: 168610; en contraste en el grupo control fue 916597:!: 47418 (p=0.012. Estos hallazgos revelan que los pacientes con PJL conforman un grupo heterogéneo en cuanto a la función de los PMN. Para esclarecer la respuesta de los PMN en cada tipo de PJL, se hace necesario estudiar la vinculación entre los componentes genéticos, el medio ambiente y los fenotipos clínicos de la enfermedad.

Real space renormalization group for spectra and density of states

International Nuclear Information System (INIS)

Wiecko, C.; Roman, E.

1984-09-01

We discuss the implementation of the Real Space Renormalization Group Decimation Technique for 1-d tight-binding models with long range interactions with or without disorder and for the 2-d regular square lattice. The procedure follows the ideas developed by Southern et al. Some new explicit formulae are included. The purpose of this study is to calculate spectra and densities of states following the procedure developed in our previous work. (author)

14 CFR 21.615 - FAA inspection.

Science.gov (United States)

2010-01-01

... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false FAA inspection. 21.615 Section 21.615 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT CERTIFICATION PROCEDURES FOR PRODUCTS AND PARTS Technical Standard Order Authorizations § 21.615 FAA inspection. Upon the...

14 CFR 21.181 - Duration.

Science.gov (United States)

2010-01-01

... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Duration. 21.181 Section 21.181 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT CERTIFICATION... those alterations performed in accordance with an applicable consensus standard and authorized by the...

Altered polymorphonuclear leukocyte Fc gamma R expression contributes to decreased candicidal activity during intraabdominal sepsis

International Nuclear Information System (INIS)

Simms, H.H.; D'Amico, R.; Monfils, P.; Burchard, K.W.

1991-01-01

We investigated the effects of untreated intraabdominal sepsis on polymorphonuclear leukocyte (PMN) candicidal activity. Two groups of swine were studied. Group I (n=6) underwent sham laparotomy, group II (n=7) underwent cecal ligation and incision. Untreated intraabdominal sepsis resulted in a progressive decrease in PMN candicidal activity. Concomitant rosetting and phagocytosis assays demonstrated a decrease in both the attachment and phagocytosis of Candida albicans opsonized with both normal and septic swine serum by PMNs in group II. Iodine 125-labeled swine immunoglobulin G (IgG) and fluorescein isothioalanate (FITC)-labeled swine IgG were used to investigate Fc gamma receptor ligand interactions. Scatchard analyses demonstrated a progressive decline in both the binding affinity constant and number of IgG molecules bound per PMN. Stimulation of the oxidative burst markedly reduced 125I-labeled IgG binding in both group I and group II, with a greater decrement being seen in animals with intraabdominal sepsis. Further, in group II, PMN recycling of the Fc gamma receptor to the cell surface after generation of the oxidative burst was reduced by postoperative day 4. Binding of monoclonal antibodies to Fc gamma receptor II, but not Fc gamma receptor I/III markedly reduced intracellular candicidal activity. Immunofluorescence studies revealed a homogeneous pattern of FITC-IgG uptake by nearly all group I PMNs, whereas by postoperative day 8 a substantial number of PMNs from group II failed to internalize the FITC-IgG. These studies suggest that untreated intraabdominal sepsis reduces PMN candicidal activity and that this is due, in part, to altered PMN Fc gamma receptor ligand interactions

METHOD OF GROUP OBJECTS FORMING FOR SPACE-BASED REMOTE SENSING OF THE EARTH

Directory of Open Access Journals (Sweden)

A. N. Grigoriev

2015-07-01

Full Text Available Subject of Research. Research findings of the specific application of space-based optical-electronic and radar means for the Earth remote sensing are considered. The subject matter of the study is the current planning of objects survey on the underlying surface in order to increase the effectiveness of sensing system due to the rational use of its resources. Method. New concept of a group object, stochastic swath and stochastic length of the route is introduced. The overview of models for single, group objects and their parameters is given. The criterion for the existence of the group object based on two single objects is formulated. The method for group objects formation while current survey planning has been developed and its description is presented. The method comprises several processing stages for data about objects with the calculation of new parameters, the stochastic characteristics of space means and validates the spatial size of the object value of the stochastic swath and stochastic length of the route. The strict mathematical description of techniques for model creation of a group object based on data about a single object and onboard special complex facilities in difficult conditions of registration of spatial data is given. Main Results. The developed method is implemented on the basis of modern geographic information system in the form of a software tool layout with advanced tools of processing and analysis of spatial data in vector format. Experimental studies of the forming method for the group of objects were carried out on a different real object environment using the parameters of modern national systems of the Earth remote sensing detailed observation Canopus-B and Resurs-P. Practical Relevance. The proposed models and method are focused on practical implementation using vector spatial data models and modern geoinformation technologies. Practical value lies in the reduction in the amount of consumable resources by means of

El Naschie's Cantorian space-time and general relativity by means of Barbilian's group. A Cantorian fractal axiomatic model of space-time

International Nuclear Information System (INIS)

Gottlieb, I.; Agop, M.; Jarcau, M.

2004-01-01

One builds the vacuum metrics of the stationary electromagnetic field through the complex potential model. There are thus emphasized both a variational principle, independent on the Ricci tensor, and some internal symmetries of the vacuum solutions. One shows that similar results may be obtained using the Barbiliant's group. By analytical continuation of a Barbilian transformation the link between the fixed points of the modular groups of the vacuum and the golden mean PHI=(1/(1+PHI))=(√5-1)/2 of ε (∞) space-time is established. Finally, a Cantorian fractal axiomatic model of the space-time is presented. The model is explained using a set of coupled equations which may describe the self organizing processes at the solid-liquid, plasma-plasma, and superconductor-superconductor interfaces

Grouped fuzzy SVM with EM-based partition of sample space for clustered microcalcification detection.

Science.gov (United States)

Wang, Huiya; Feng, Jun; Wang, Hongyu

2017-07-20

Detection of clustered microcalcification (MC) from mammograms plays essential roles in computer-aided diagnosis for early stage breast cancer. To tackle problems associated with the diversity of data structures of MC lesions and the variability of normal breast tissues, multi-pattern sample space learning is required. In this paper, a novel grouped fuzzy Support Vector Machine (SVM) algorithm with sample space partition based on Expectation-Maximization (EM) (called G-FSVM) is proposed for clustered MC detection. The diversified pattern of training data is partitioned into several groups based on EM algorithm. Then a series of fuzzy SVM are integrated for classification with each group of samples from the MC lesions and normal breast tissues. From DDSM database, a total of 1,064 suspicious regions are selected from 239 mammography, and the measurement of Accuracy, True Positive Rate (TPR), False Positive Rate (FPR) and EVL = TPR* 1-FPR are 0.82, 0.78, 0.14 and 0.72, respectively. The proposed method incorporates the merits of fuzzy SVM and multi-pattern sample space learning, decomposing the MC detection problem into serial simple two-class classification. Experimental results from synthetic data and DDSM database demonstrate that our integrated classification framework reduces the false positive rate significantly while maintaining the true positive rate.

The bicovariant differential calculus on the κ-Poincare group and on the κ-Minkowski space

International Nuclear Information System (INIS)

Kosinski, P.; Maslanka, P.; Sobczyk, J.

1996-01-01

The bicovariant differential calculus on the four-dimensional κ-Poincare group and the corresponding Lie-algebra-like structure are described. The differential calculus on the n-dimensional κ-Minkowski space covariant under the action of the κ-Poincare group was constructed. 5 refs

Extended system of space-time coordinates and generalized translation group of transformations

International Nuclear Information System (INIS)

Yamaleev, R.M.

1980-01-01

A method of extending space-time is considered. In the nonrelativistic case extending goes by joining a scalar to the 3-dimensional radius-vector, completing this to a quaternion. The interpretation of scalar obtained as a parameter of scale transfornation of the generalized translation of group of transformations is given. Some basic expressions of nonrelativistic classical mechanics in the quaternion representation are given. In the relativistic case space-time is constructed from two quaternions: the first one consists of a pair scalar-3-dimensional radius-vector; the second one, of a pair-time-scalar-3-dimensional time-vector. Time and space coordinates, enter into the expression with the opposite signature. The introduction of a time-vector as well as of a new scalar is stipulated by the requirement of the principle of conforming quantum mechanics of the 1/2 spin to classical mechanics [ru

Canonical Groups for Quantization on the Two-Dimensional Sphere and One-Dimensional Complex Projective Space

International Nuclear Information System (INIS)

Sumadi A H A; H, Zainuddin

2014-01-01

Using Isham's group-theoretic quantization scheme, we construct the canonical groups of the systems on the two-dimensional sphere and one-dimensional complex projective space, which are homeomorphic. In the first case, we take SO(3) as the natural canonical Lie group of rotations of the two-sphere and find all the possible Hamiltonian vector fields, and followed by verifying the commutator and Poisson bracket algebra correspondences with the Lie algebra of the group. In the second case, the same technique is resumed to define the Lie group, in this case SU (2), of CP'.We show that one can simply use a coordinate transformation from S 2 to CP 1 to obtain all the Hamiltonian vector fields of CP 1 . We explicitly show that the Lie algebra structures of both canonical groups are locally homomorphic. On the other hand, globally their corresponding canonical groups are acting on different geometries, the latter of which is almost complex. Thus the canonical group for CP 1 is the double-covering group of SO(3), namely SU(2). The relevance of the proposed formalism is to understand the idea of CP 1 as a space of where the qubit lives which is known as a Bloch sphere

Space Weather Activities of IONOLAB Group: IONOLAB-TEC

Science.gov (United States)

Arikan, F.; Sezen, U.; Arikan, O.; Ugurlu, O.; Nayir, H.

2009-04-01

Space Weather (SW) is the concept of changing environmental conditions in outer space and affect Earth and its technological systems. SW is a consequence of the solar activities and the coupling of solar energy on Earth's atmosphere due to the Earth's magnetic field. The monitoring and prediction of SW has utmost importance for HF communication, Satellite communication, navigation and guidance systems, Low Earth Orbit (LEO) satellite systems, Space Craft exit and entry into the atmosphere. Ionosphere is the plasma layer of the atmosphere that is ionized by solar radiation and it is a key player of SW. Ionosphere is a temporally and spatially varying, dispersive, anisotropic and inhomogeneous medium that is characterized primarily by its electron density distribution. IONOLAB is a group of researchers of various disciplines, getting together to handle challenges of the Earth's ionosphere. The team has researchers from Hacettepe University and Bilkent University, Department of Electrical and Electronics Engineering and General Command of Mapping of Turkish Army. One of the most important contributions of IONOLAB group is the automated web-based computation service for Total Electron Content (TEC). TEC corresponds to the line integral of electron density distribution on a given path. TEC can also be expressed as the amount of free electrons within 1 m2 cross-sectional area of the cylinder on the ray path. Global Position System (GPS) provides a cost-effective medium for monitoring of ionosphere using the signals recorded by stationary GPS receivers in estimating TEC. IONOLAB group has developed IONOLAB-TEC for reliable and robust estimates for all latitudes and both calm and disturbed days by using RINEX, IONEX and satellite ephemeris data provided from the IGS centers. IONOLAB-TEC consists of a regularized signal estimation algorithm which combines signals from all GPS satellites for a given instant and a given receiver, for a desired time period or for 24 hours

Realization of vector fields for quantum groups as pseudodifferential operators on quantum spaces

International Nuclear Information System (INIS)

Chu, Chong-Sun; Zumino, B.

1995-01-01

The vector fields of the quantum Lie algebra are described for the quantum groups GL q (n), SL q (N) and SO q (N) as pseudodifferential operators on the linear quantum spaces covariant under the corresponding quantum group. Their expressions are simple and compact. It is pointed out that these vector fields satisfy certain characteristic polynomial identities. The real forms SU q (N) and SO q (N,R) are discussed in detail

Assessment of space plasma effectsfor satellite applications:Working Group 2 overview

Directory of Open Access Journals (Sweden)

N. Jakowski

2004-06-01

Full Text Available An important part of the tasks of Working Group 2 of the COST Action 271 «Assessment of space plasma effect for satellites applications» is the assessment of novel data sources for information about the state of ionisation of the ionosphere. This report deals with those aspects which are not represented adequately in the scientific papers in this issue. Here emphasis is given to the product aspect (data and model collections, descriptions of methods and algorithms, availability of products, expected future developments and the links between the past COST Actions 238 and 251 with the present Action 271 and with possible future cooperations. Working Group 2 was leading in the transionospheric propagation aspects of possible products for the International Telecommunication Union?s Radiocommunication (ITU-R Study Group 3. This report gives a short overview emphasizing future developments.

Weighted Composition Operators from Hardy Spaces into Logarithmic Bloch Spaces

Directory of Open Access Journals (Sweden)

Flavia Colonna

2012-01-01

Full Text Available The logarithmic Bloch space Blog⁡ is the Banach space of analytic functions on the open unit disk 𝔻 whose elements f satisfy the condition ∥f∥=sup⁡z∈𝔻(1-|z|2log⁡  (2/(1-|z|2|f'(z|<∞. In this work we characterize the bounded and the compact weighted composition operators from the Hardy space Hp (with 1≤p≤∞ into the logarithmic Bloch space. We also provide boundedness and compactness criteria for the weighted composition operator mapping Hp into the little logarithmic Bloch space defined as the subspace of Blog⁡ consisting of the functions f such that lim⁡|z|→1(1-|z|2log⁡  (2/(1-|z|2|f'(z|=0.

14 CFR 21.8 - Approval of articles.

Science.gov (United States)

2010-01-01

... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Approval of articles. 21.8 Section 21.8 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT CERTIFICATION PROCEDURES FOR PRODUCTS AND PARTS General § 21.8 Approval of articles. If an article is required to be...

Fourier-space TEM reconstructions with symmetry adapted functions for all rotational point groups.

Science.gov (United States)

Trapani, Stefano; Navaza, Jorge

2013-05-01

A general-purpose and simple expression for the coefficients of symmetry adapted functions referred to conveniently oriented symmetry axes is given for all rotational point groups. The expression involves the computation of reduced Wigner-matrix elements corresponding to an angle specific to each group and has the computational advantage of leading to Fourier-space TEM (transmission electron microscopy) reconstruction procedures involving only real valued unknowns. Using this expression, a protocol for ab initio view and center assignment and reconstruction so far used for icosahedral particles has been tested with experimental data in other point groups. Copyright © 2013 Elsevier Inc. All rights reserved.

The Community-based Organizations Working Group of the Space Science Education Support Network

Science.gov (United States)

Lutz, J. H.; Lowes, L. L.; Asplund, S.

2004-12-01

The NASA Space Science Support Network Community-based Organizations Working Group (CBOWG) has been working for the past two years on issues surrounding afterschool programs and programs for youth (e.g., Girl Scouts, Boy Scouts, Boys and Girls Clubs, 4-H, summer camps, afterschool and weekend programs for various ages, programs with emphases on minority youth). In this session the co-leaders of the CBOWG will discuss the challenges of working with community-based organizations on a regional or national level. We will highlight some ties that we have forged with the National Institute for Out of School Time (NIOST) and the National Afterschool Association (NAA). We will also talk about efforts to coordinate how various entities within NASA cooperate with community-based organizations to serve the best interests of these groups. We will give a couple of examples of how NASA space science organizations have partnered with community-based organizations. The session will include some handouts of information and resources that the CBOWG has found useful in developing an understanding of this segment of informal education groups. We would like to thank NASA for providing resources to support the work of the CBOWG.

Cosmological time in (2+1)-gravity

International Nuclear Information System (INIS)

Benedetti, Riccardo; Guadagnini, Enore

2001-01-01

We consider maximal globally hyperbolic flat (2+1)-spacetimes with compact space S of genus g>1. For any spacetime M of this type, the length of time that the events have been in existence is M defines a global time, called the cosmological time CT of M, which reveals deep intrinsic properties of spacetime. In particular, the past/future asymptotic states of the cosmological time recover and decouple the linear and the translational parts of the ISO(2,1)-valued holonomy of the flat spacetime. The initial singularity can be interpreted as an isometric action of the fundamental group of S on a suitable real tree. The initial singularity faithfully manifests itself as a lack of smoothness of the embedding of the CT level surfaces into the spacetime M. The cosmological time determines a real analytic curve in the Teichmueller space of Riemann surfaces of genus g, which connects an interior point (associated to the linear part of the holonomy) with a point on Thurston's natural boundary (associated to the initial singularity)

Cosmological time in /(2+1)-gravity

Science.gov (United States)

Benedetti, Riccardo; Guadagnini, Enore

2001-10-01

We consider maximal globally hyperbolic flat (2+1)-spacetimes with compact space S of genus g>1. For any spacetime M of this type, the length of time that the events have been in existence is M defines a global time, called the cosmological time CT of M, which reveals deep intrinsic properties of spacetime. In particular, the past/future asymptotic states of the cosmological time recover and decouple the linear and the translational parts of the ISO(2,1)-valued holonomy of the flat spacetime. The initial singularity can be interpreted as an isometric action of the fundamental group of S on a suitable real tree. The initial singularity faithfully manifests itself as a lack of smoothness of the embedding of the CT level surfaces into the spacetime M. The cosmological time determines a real analytic curve in the Teichmüller space of Riemann surfaces of genus g, which connects an interior point (associated to the linear part of the holonomy) with a point on Thurston's natural boundary (associated to the initial singularity).

Comparison of the Cc and R3c space groups for the superlattice phase of Pb(Zr0.52Ti0.48)O3

International Nuclear Information System (INIS)

Ranjan, Rajeev; Singh, Akhilesh Kumar; Ragini; Pandey, Dhananjai

2005-01-01

Recent controversy about the space group of the low temperature superlattice phase of Pb(Zr 0.52 Ti 0.48 )O 3 is settled. It is shown that the R3c space group for the superlattice phase cannot correctly account for the peak positions of the superlattice reflections present in the neutron diffraction patterns. The correct space group is reconfirmed to be Cc. A comparison of the atomic coordinates of Cc and Cm space groups is also presented to show that in the absence of superlattice reflections, as is the case with x-ray diffraction data, one would land up in the Cm space group. This superlattice phase is found to coexist with another monoclinic phase of the Cm space group

Effect of the compressive stress on both polarization rotation and phase transitions in PMN-30%PT single crystal

Directory of Open Access Journals (Sweden)

Hui Zhang

2014-05-01

Full Text Available In this paper, we have investigated the dependence of both the electromechanical effect and the electrostriction on the compressive stress in PMN-30%PT single crystal on the basis of single domain polarization rotation model. In the model, the electroelastic energy induced by the compressive stress is taken into account. The results have demonstrated that the compressive stress can lead to a significant change in the initial polarization state in the crystal. The reason lies in the stress induced anisotropy which is the coupling between the compressive stress and the electrostrictive coefficients. Thus, the initial polarization state in single crystal is determined by the combination of both electrocrystalline anisotropy and the stress induced anisotropy. The compressive stress along the [100] axis can make the polarization in the crystal be perpendicular to the stress direction, and make it difficult to be polarized to the saturation. This model is useful for better understanding both the polarization rotation and electromechanical effect in ferroelectric crystals with the compressive stress present.

14 CFR 399.21 - Charter exemptions (except military).

Science.gov (United States)

2010-01-01

... 14 Aeronautics and Space 4 2010-01-01 2010-01-01 false Charter exemptions (except military). 399.21 Section 399.21 Aeronautics and Space OFFICE OF THE SECRETARY, DEPARTMENT OF TRANSPORTATION... Authority § 399.21 Charter exemptions (except military). In deciding applications for exemptions from...

Rietveld refinement and electronic structure studies for the Sm2FeMnO6 new complex perovskite

International Nuclear Information System (INIS)

Landinez Tellez, D.A.; Munevar, J.A.; Arbey Rodriguez, J.M.; Fajardo, F.; Roa-Rojas, J.

2008-01-01

We report synthesis and crystalline structure study of the Sm 2 FeMnO 6 new complex perovskite, by X-ray diffraction experiments and through the application of Rietveld refinement. Results revealed the crystallization of system in a structure given by Pmn21 (no. 31) space group and lattice parameters a=7.621(1) A, b=5.675(3) A and c=5.378(3) A. Ab initio calculations of density of states (DOS) and electronic structure were carried out for this perovskite-like system by the density functional theory (DFT) and using the full-potential linearized augmented plane waves (FP-LAPW) method. All calculations were carried out using spin polarization. Material evidences a conductor-like character, predominantly due to d-xy Fe orbital of the spin down channel. Magnetic response of system has contributions of Fe and Mn spin up orientation. The calculated magnetic moment in cell was 34.48 μ B and the magnetic moment in interstitial was 1.54 μ B

Group-velocity dispersion effects on quantum noise of a fiber optical soliton in phase space

International Nuclear Information System (INIS)

Ju, Heongkyu; Lee, Euncheol

2010-01-01

Group-velocity dispersion (GVD) effects on quantum noise of ultrashort pulsed light are theoretically investigated at the soliton energy level, using Gaussian-weighted pseudo-random distribution of phasors in phase space for the modeling of quantum noise properties including phase noise, photon number noise, and quantum noise shape in phase space. We present the effects of GVD that mixes the different spectral components in time, on the self-phase modulation(SPM)-induced quantum noise properties in phase space such as quadrature squeezing, photon-number noise, and tilting/distortion of quantum noise shape in phase space, for the soliton that propagates a distance of the nonlinear length η NL = 1/( γP 0 ) (P 0 is the pulse peak power and γ is the SPM parameter). The propagation dependence of phase space quantum noise properties for an optical soliton is also provided.

Implementation of small group discussion as a teaching method in earth and space science subject

Science.gov (United States)

Aryani, N. P.; Supriyadi

2018-03-01

In Physics Department Universitas Negeri Semarang, Earth and Space Science subject is included in the curriculum of the third year of physics education students. There are various models of teaching earth and space science subject such as textbook method, lecturer, demonstrations, study tours, problem-solving method, etc. Lectures method is the most commonly used of teaching earth and space science subject. The disadvantage of this method is the lack of two ways interaction between lecturers and students. This research used small group discussion as a teaching method in Earth and Space science. The purpose of this study is to identify the conditions under which an efficient discussion may be initiated and maintained while students are investigating properties of earth and space science subjects. The results of this research show that there is an increase in student’s understanding of earth and space science subject proven through the evaluation results. In addition, during the learning process, student’s activeness also increase.

EFSA Panel on Food Contact Materials, Enzymes, Flavourings and Processing Aids (CEF); Scientific Opinion on Flavouring Group Evaluation 21, Revision 2 (FGE.21Rev2): Thiazoles, thiophene, thiazoline and thienyl derivatives from chemical group 29. Miscellaneous substances from chemical group 30

DEFF Research Database (Denmark)

Larsen, John Christian; Nørby, Karin Kristiane; Beltoft, Vibe Meister

The Panel on Food Contact Materials, Enzymes, Flavourings and Processing Aids of the European Food Safety Authority was requested to evaluate 56 flavouring substances in the Flavouring Group Evaluation 21, Revision 2, using the Procedure in Commission Regulation (EC) No 1565/2000. Seven...... of commerce have also been considered. For two substances are an identity test lacking and for one has the stereoisomeric composition to be specified....

Positive-definite functions and unitary representations of locally compact groups in a Hilbert space

International Nuclear Information System (INIS)

Gali, I.M.; Okb el-Bab, A.S.; Hassan, H.M.

1977-08-01

It is proved that the necessary and sufficient condition for the existence of an integral representation of a group of unitary operators in a Hilbert space is that it is positive-definite and continuous in some topology

Non-commutative phase space and its space-time symmetry

International Nuclear Information System (INIS)

Li Kang; Dulat Sayipjamal

2010-01-01

First a description of 2+1 dimensional non-commutative (NC) phase space is presented, and then we find that in this formulation the generalized Bopp's shift has a symmetric representation and one can easily and straightforwardly define the star product on NC phase space. Then we define non-commutative Lorentz transformations both on NC space and NC phase space. We also discuss the Poincare symmetry. Finally we point out that our NC phase space formulation and the NC Lorentz transformations are applicable to any even dimensional NC space and NC phase space. (authors)

21 CFR 1403.21 - Payment.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 9 2010-04-01 2010-04-01 false Payment. 1403.21 Section 1403.21 Food and Drugs... opportunities for minority business enterprises, grantees and subgrantees are encouraged to use minority banks (a bank which is owned at least 50 percent by minority group members). A list of minority owned banks...

Loop space representation of quantum general relativity and the group of loops

International Nuclear Information System (INIS)

Gambini, R.

1991-01-01

The action of the constraints of quantum general relativity on a general state in the loop representation is coded in terms of loop derivatives. These differential operators are related to the infinitesimal generators of the group of loops and generalize the area derivative first considered by Mandelstam. A new sector of solutions of the physical states space of nonperturbative quantum general relativity is found. (orig.)

Generalized 2-vector spaces and general linear 2-groups

OpenAIRE

Elgueta, Josep

2008-01-01

In this paper a notion of {\\it generalized 2-vector space} is introduced which includes Kapranov and Voevodsky 2-vector spaces. Various kinds of generalized 2-vector spaces are considered and examples are given. The existence of non free generalized 2-vector spaces and of generalized 2-vector spaces which are non Karoubian (hence, non abelian) categories is discussed, and it is shown how any generalized 2-vector space can be identified with a full subcategory of an (abelian) functor category ...

Distributed Model Predictive Control over Multiple Groups of Vehicles in Highway Intelligent Space for Large Scale System

Directory of Open Access Journals (Sweden)

Tang Xiaofeng

2014-01-01

Full Text Available The paper presents the three time warning distances for solving the large scale system of multiple groups of vehicles safety driving characteristics towards highway tunnel environment based on distributed model prediction control approach. Generally speaking, the system includes two parts. First, multiple vehicles are divided into multiple groups. Meanwhile, the distributed model predictive control approach is proposed to calculate the information framework of each group. Each group of optimization performance considers the local optimization and the neighboring subgroup of optimization characteristics, which could ensure the global optimization performance. Second, the three time warning distances are studied based on the basic principles used for highway intelligent space (HIS and the information framework concept is proposed according to the multiple groups of vehicles. The math model is built to avoid the chain avoidance of vehicles. The results demonstrate that the proposed highway intelligent space method could effectively ensure driving safety of multiple groups of vehicles under the environment of fog, rain, or snow.

Planning and managing future space facility projects. [management by objectives and group dynamics

Science.gov (United States)

Sieber, J. E.; Wilhelm, J. A.; Tanner, T. A.; Helmreich, R. L.; Burgenbauch, S. F.

1979-01-01

To learn how ground-based personnel of a space project plan and organize their work and how such planning and organizing relate to work outcomes, longitudinal study of the management and execution of the Space Lab Mission Development Test 3 (SMD 3) was performed at NASA Ames Research Center. A view of the problems likely to arise in organizations and some methods of coping with these problems are presented as well as the conclusions and recommendations that pertain strictly to SMD 3 management. Emphasis is placed on the broader context of future space facility projects and additional problems that may be anticipated. A model of management that may be used to facilitate problem solving and communication - management by objectives (MBO) is presented. Some problems of communication and emotion management that MBO does not address directly are considered. Models for promoting mature, constructive and satisfying emotional relationships among group members are discussed.

Cytokine production by oral and peripheral blood neutrophils in adult periodontitis.

Science.gov (United States)

Galbraith, G M; Hagan, C; Steed, R B; Sanders, J J; Javed, T

1997-09-01

Proinflammatory cytokines such as tumor necrosis factor-alpha (TNF-alpha) and interleukin 1 beta (IL-1 beta) also possess bone-resorptive properties, and are generally considered to play a role in the pathogenesis of periodontal disease. In the present study, TNF-alpha and IL-1 beta production by oral and peripheral blood polymorphonuclear leukocytes (PMN) was examined in 40 patients with adult periodontitis and 40 orally healthy matched controls. Oral PMN released considerable amounts of both cytokines in unstimulated culture, and there was no difference between patients and controls when the cytokine levels were corrected for cell number. However, when the effect of disease activity was examined, cytokine release by oral PMN was found to be greatest in patients with advanced periodontitis. Within the healthy control group, IL-1 beta production by oral PMN was significantly higher in males (Mann-Whitney test, P = 0.0008). Examination of IL-1 beta production by peripheral blood PMN exposed to recombinant human granulocyte-macrophage colony stimulating factor revealed no difference between the patient and control groups. In contrast, IL-1 beta production by peripheral blood PMN was significantly reduced in patients with advanced disease (Mann-Whitney test, P = 0.02), and peripheral PMN IL-1 beta synthesis was greater in female controls (Mann-Whitney test, P = 0.054). No effect of race on cytokine production could be discerned in patients or controls. These results indicate that several factors influence cytokine production in oral health and disease, and that a dichotomy in cytokine gene expression exists between oral and peripheral blood PMN in adult periodontitis.

Group Analysis in MNE-Python of Evoked Responses from a Tactile Stimulation Paradigm: A Pipeline for Reproducibility at Every Step of Processing, Going from Individual Sensor Space Representations to an across-Group Source Space Representation.

Science.gov (United States)

Andersen, Lau M

2018-01-01

An important aim of an analysis pipeline for magnetoencephalographic data is that it allows for the researcher spending maximal effort on making the statistical comparisons that will answer the questions of the researcher, while in turn spending minimal effort on the intricacies and machinery of the pipeline. I here present a set of functions and scripts that allow for setting up a clear, reproducible structure for separating raw and processed data into folders and files such that minimal effort can be spend on: (1) double-checking that the right input goes into the right functions; (2) making sure that output and intermediate steps can be accessed meaningfully; (3) applying operations efficiently across groups of subjects; (4) re-processing data if changes to any intermediate step are desirable. Applying the scripts requires only general knowledge about the Python language. The data analyses are neural responses to tactile stimulations of the right index finger in a group of 20 healthy participants acquired from an Elekta Neuromag System. Two analyses are presented: going from individual sensor space representations to, respectively, an across-group sensor space representation and an across-group source space representation. The processing steps covered for the first analysis are filtering the raw data, finding events of interest in the data, epoching data, finding and removing independent components related to eye blinks and heart beats, calculating participants' individual evoked responses by averaging over epoched data and calculating a grand average sensor space representation over participants. The second analysis starts from the participants' individual evoked responses and covers: estimating noise covariance, creating a forward model, creating an inverse operator, estimating distributed source activity on the cortical surface using a minimum norm procedure, morphing those estimates onto a common cortical template and calculating the patterns of activity

Group Analysis in MNE-Python of Evoked Responses from a Tactile Stimulation Paradigm: A Pipeline for Reproducibility at Every Step of Processing, Going from Individual Sensor Space Representations to an across-Group Source Space Representation

Directory of Open Access Journals (Sweden)

Lau M. Andersen

2018-01-01

Full Text Available An important aim of an analysis pipeline for magnetoencephalographic data is that it allows for the researcher spending maximal effort on making the statistical comparisons that will answer the questions of the researcher, while in turn spending minimal effort on the intricacies and machinery of the pipeline. I here present a set of functions and scripts that allow for setting up a clear, reproducible structure for separating raw and processed data into folders and files such that minimal effort can be spend on: (1 double-checking that the right input goes into the right functions; (2 making sure that output and intermediate steps can be accessed meaningfully; (3 applying operations efficiently across groups of subjects; (4 re-processing data if changes to any intermediate step are desirable. Applying the scripts requires only general knowledge about the Python language. The data analyses are neural responses to tactile stimulations of the right index finger in a group of 20 healthy participants acquired from an Elekta Neuromag System. Two analyses are presented: going from individual sensor space representations to, respectively, an across-group sensor space representation and an across-group source space representation. The processing steps covered for the first analysis are filtering the raw data, finding events of interest in the data, epoching data, finding and removing independent components related to eye blinks and heart beats, calculating participants' individual evoked responses by averaging over epoched data and calculating a grand average sensor space representation over participants. The second analysis starts from the participants' individual evoked responses and covers: estimating noise covariance, creating a forward model, creating an inverse operator, estimating distributed source activity on the cortical surface using a minimum norm procedure, morphing those estimates onto a common cortical template and calculating the patterns

Representation theory of 2-groups on finite dimensional 2-vector spaces

OpenAIRE

Elgueta, Josep

2004-01-01

In this paper, the 2-category $\\mathfrak{Rep}_{{\\bf 2Mat}_{\\mathbb{C}}}(\\mathbb{G})$ of (weak) representations of an arbitrary (weak) 2-group $\\mathbb{G}$ on (some version of) Kapranov and Voevodsky's 2-category of (complex) 2-vector spaces is studied. In particular, the set of equivalence classes of representations is computed in terms of the invariants $\\pi_0(\\mathbb{G})$, $\\pi_1(\\mathbb{G})$ and $[\\alpha]\\in H^3(\\pi_0(\\mathbb{G}),\\pi_1(\\mathbb{G}))$ classifying $\\mathbb{G}$. Also the categ...

14 CFR 35.21 - Variable and reversible pitch propellers.

Science.gov (United States)

2010-01-01

... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Variable and reversible pitch propellers. 35.21 Section 35.21 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: PROPELLERS Design and Construction § 35.21 Variable and...

Odontogenic versus nonodontogenic deep neck space infections: CT manifestations

International Nuclear Information System (INIS)

Kim, Hyung Jin; Park, Eui Dong; Kim, Jung Hee; Kim, Jae Hyoung; Hwang, Eui Gee; Chung, Sung Hoon

1995-01-01

The purpose of this study was to evaluate computed tomographic (CT) findings of deep neck space infection (DNSI) with particular attention to the differences in the spaces involved and in complications between odontogenic and nonodontogenic groups. Forty-four patients (21 odontogenic and 23 nonodontogenic) were included in this study. Among odontogenic DNSIs, 15 had the dental infection in the second or third mandibular molar. We compared the CT features between odontogenic and nonodontogenic DNSIs with special emphasis on the differences in the spaces involved and in the rate and type of complications. In all patients, CT clearly differentiated abscess from cellulitis. The most common spaces involved in 21 patients with odontogenic DNSI were the parapharyngeal (n = 18), the submandibular (n = 18), the anterior visceral (n = 13), the masticator (n = 9), and the sublingual (n 7) spaces. In contrast, in 23 patients with nonodontogenic DNSI, the anterior visceral space (n = 14) was most frequently involved. The parapharyngeal, the submandibular, and the masticator spaces were statistically more frequently involved in odontogenic than in nonodontogenic DNSI (ρ < .05). Twenty-two patients had one or more complications shown by CT, of which airway compromise was more frequent and severe in odontogenic than in nonodontogenic DNSI. We conclude that the parapharyngeal, the submandibular, and the masticator spaces are more significantly vulnerable in odontogenic DNSI than in nonodontogenic DNSI. The predilection for certain spaces of the neck in odontogenic DNSI seems to originate from the intimate relationship of the mandibular molars to the adjacent deep neck spaces

Generating Lie Point Symmetry Groups of (2+1)-Dimensional Broer-Kaup Equation via a Simple Direct Method

International Nuclear Information System (INIS)

Ma Hongcai

2005-01-01

Using the (2+1)-dimensional Broer-Kaup equation as an simple example, a new direct method is developed to find symmetry groups and symmetry algebras and then exact solutions of nonlinear mathematical physical equations.

Minocycline affects human neutrophil respiratory burst and transendothelial migration.

Science.gov (United States)

Parenti, Astrid; Indorato, Boris; Paccosi, Sara

2017-02-01

This study aimed at investigating the in vitro activity of minocycline and doxycycline on human polymorphonuclear (h-PMN) cell function. h-PMNs were isolated from whole venous blood of healthy subjects; PMN oxidative burst was measured by monitoring ROS-induced oxidation of luminol and transendothelial migration was studied by measuring PMN migration through a monolayer of human umbilical vein endothelial cells. Differences between multiple groups were determined by ANOVA followed by Tukey's multiple comparison test; Student's t test for unpaired data for two groups. Minocycline (1-300 µM) concentration dependently and significantly inhibited oxidative burst of h-PMNs stimulated with 100 nM fMLP. Ten micromolar concentrations, which are superimposable to C max following a standard oral dose of minocycline, promoted a 29.8 ± 4 % inhibition of respiratory burst (P minocycline impaired PMN transendothelial migration, with maximal effect at 100 µM (42.5 ± 7 %, inhibition, n = 5, P minocycline exerted on innate immune h-PMN cell function.

Surface-bound capsular polysaccharide of type Ia group B Streptococcus mediates C1 binding and activation of the classic complement pathway

International Nuclear Information System (INIS)

Levy, N.J.; Kasper, D.L.

1986-01-01

The role of surface-bound type Ia group B Streptococcus (GBS) capsular polysaccharide in anti-body-independent binding of C1 and activation of the classic component pathway was investigated. In a radiolabeled bacterial-polymorphonuclear leukocyte (PMN) association assay, a measure of bacterial opsonization, preincubation of 3 H-type Ia GBS with purified F(ab') 2 to the organism blocked the association of the bacteria with PMN', and the inhibitory effect was dose dependent. The specificity of F(ab') 2 blocking was shown after adsorption of F(ab') 2 with type Ia polysaccharide-sensitized erythrocytes. Polysaccharide-adsorbed F(ab') 2 had a 70% decrease in ability to block the association of bacteria with PMN. Neuraminidase digestion removed 80% of the terminal sialic acid residues from the native polysaccharide. These neuraminidase-digested organisms had a 72% decrease in binding and transfer of purified C1 compared with non-enzyme-treated organisms. Type Ia capsular polysaccharide bound to sheep erythrocytes promoted classic complement pathway-mediated hemolysis of the cells. The role of C1 inhibitor (INH) in modulation of C1 activation by the organisms was investigated. The possibility existed that the C1 INH could be bound by the bacteria, allowing C1 activation to occur in the fluid phase. The inhibitor was purified from human serum, and its activity was measured before and after incubation with type Ia GBS. The organisms had no effect on C1 INH activity. Thus surface-bound capsular polysacchardie of type Ia GBS mediates C1 binding and classic pathway activation, and this does not involve the C1 INH

Yukawa couplings between (2,1)-forms

International Nuclear Information System (INIS)

Candelas, P.

1988-01-01

The compactification of superstrings leads to an effective field theory for which the space-time manifold is the product of a four-dimensional Minkowski space with a six-dimensional Calabi-Yau space. The particles that are massless in the four-dimensional world correspond to differential forms of type (1,1) and of type (2,1) on the Calabi-Yau space. The Yukawa couplings between the families correspond to certain integrals involving three differential forms. For an important class of Calabi-Yau manifolds, which includes the cases for which the manifold may be realized as a complete intersection of polynomial equations in a projective space, the families correspond to (2,1)-forms. The relation between (2,1)-forms and the geometrical deformations of the Calabi-Yau space is explained and it is shown, for those cases for which the manifold may be realized as the complete intersection of polynomial equations in a single projective space or for many cases when the manifold may be realized as the transverse intersection of polynomial equations in a product of projective spaces, that the calculation of the Yukawa coupling reduces to a purely algebraic problem involving the defining polynomials. The generalization of this process is presented for a general Calabi-Yau manifold. (orig.)

Independence of automorphism group, center, and state space of quantum logics

International Nuclear Information System (INIS)

Navara, M.

1992-01-01

We prove that quantum logics (-orthomodular posets) admit full independence of the attributes important within the foundations of quantum mechanics. Namely, we present the construction of quantum logics with given sublogics (=physical subsystems), automorphism groups, centers (=open-quotes classical partsclose quotes of the systems), and state spaces. Thus, all these open-quotes parametersclose quotes are independent. Our result is rooted in the line of investigation carried out by Greechie; Kallus and Trnkova; Kalmbach; and Navara and Ptak; and considerably enriches the known algebraic methods in orthomodular posets. 19 refs., 1 fig

Vision-21: Space Travel for the Next Millennium

International Nuclear Information System (INIS)

Landis, G.A.

1990-04-01

The papers from this symposium, that was held at the NASA Lewis Research Center on April 3-4, 1990, are presented. The theme selected for the symposium was space travel for the next millennium. It was hoped that the participants would allow their focus to consider possible advances in technologies for space travel not just for currently envisioned projects, but for possibilities beyond the next generation and the next thousand years. About half of the contributed papers focussed on propulsion and the other half on other issues related to space travel

Does the Health Impact of Exposure to Neighbourhood Green Space Differ between Population Groups? An Explorative Study in Four European Cities

Science.gov (United States)

Ruijsbroek, Annemarie; Droomers, Mariël; Kruize, Hanneke; van Kempen, Elise; Gidlow, Christopher J.; Hurst, Gemma; Andrusaityte, Sandra; Nieuwenhuijsen, Mark J.; Maas, Jolanda; Hardyns, Wim; Stronks, Karien; Groenewegen, Peter P.

2017-01-01

It has been suggested that certain residents, such as those with a low socioeconomic status, the elderly, and women, may benefit more from the presence of neighbourhood green space than others. We tested this hypothesis for age, gender, educational level, and employment status in four European cities. Data were collected in Barcelona (Spain; n = 1002), Kaunas (Lithuania; n = 989), Doetinchem (The Netherlands; n = 847), and Stoke-on-Trent (UK; n = 933) as part of the EU-funded PHENOTYPE project. Surveys were used to measure mental and general health, individual characteristics, and perceived neighbourhood green space. Additionally, we used audit data about neighbourhood green space. In Barcelona, there were positive associations between neighbourhood green space and general health among low-educated residents. In the other cities and for the other population groups, there was little evidence that the association between health and neighbourhood green space differed between population groups. Overall, our study does not support the assumption that the elderly, women, and residents who are not employed full-time benefit more from neighbourhood green space than others. Only in the highly urbanised city of Barcelona did the low-educated group benefit from neighbourhood green spaces. Perhaps neighbourhood green spaces are more important for the health of low-educated residents in particularly highly urbanised areas. PMID:28594390

Does the Health Impact of Exposure to Neighbourhood Green Space Differ between Population Groups? An Explorative Study in Four European Cities.

Science.gov (United States)

Ruijsbroek, Annemarie; Droomers, Mariël; Kruize, Hanneke; van Kempen, Elise; Gidlow, Christopher J; Hurst, Gemma; Andrusaityte, Sandra; Nieuwenhuijsen, Mark J; Maas, Jolanda; Hardyns, Wim; Stronks, Karien; Groenewegen, Peter P

2017-06-08

It has been suggested that certain residents, such as those with a low socioeconomic status, the elderly, and women, may benefit more from the presence of neighbourhood green space than others. We tested this hypothesis for age, gender, educational level, and employment status in four European cities. Data were collected in Barcelona (Spain; n = 1002), Kaunas (Lithuania; n = 989), Doetinchem (The Netherlands; n = 847), and Stoke-on-Trent (UK; n = 933) as part of the EU-funded PHENOTYPE project. Surveys were used to measure mental and general health, individual characteristics, and perceived neighbourhood green space. Additionally, we used audit data about neighbourhood green space. In Barcelona, there were positive associations between neighbourhood green space and general health among low-educated residents. In the other cities and for the other population groups, there was little evidence that the association between health and neighbourhood green space differed between population groups. Overall, our study does not support the assumption that the elderly, women, and residents who are not employed full-time benefit more from neighbourhood green space than others. Only in the highly urbanised city of Barcelona did the low-educated group benefit from neighbourhood green spaces. Perhaps neighbourhood green spaces are more important for the health of low-educated residents in particularly highly urbanised areas.

R-102, 1 Group Space-Independent Inverse Reactor Kinetics

International Nuclear Information System (INIS)

Kaganove, J.J.

1966-01-01

1 - Description of problem or function: Given the space-independent, one energy group reactor kinetics equations and the initial conditions, this program determines the time variation of reactivity required to produce the given input of flux-time data. 2 - Method of solution: Time derivatives of neutron density are obtained by application of (a) five-point quartic, (b) three-point parabolic, (c) five-point least-mean-square cubic, (d) five-point least-mean-square parabolic, or (e) five-point least-mean-square linear formulae to the neutron density or to the natural logarithm of the neutron density. Between each data point the neutron density is assumed to be (a) exponential*(third-order polynomial), (b) exponential, or (c) linear. Changes in reactivity between data points are obtained algebraically from the kinetics equations, neutron density derivatives, and the algebraic representation of neutron density. First and second time derivatives of the reactivity are obtained by use of any of the formulae applicable to the neutron density. 3 - Restrictions on the complexity of the problem: Maxima of - 50 delay groups; 1000 data points; 99 data blocks (A data block is a sequence of input points characterized by a fixed time-interval between points, a smoothing option, and a number of repetitions of the smoothing option)

Space-group approach to two-electron states in unconventional superconductors

International Nuclear Information System (INIS)

Yarzhemsky, V. G.

2008-01-01

The direct application of the space-group representation theory, makes possible to obtain limitations for the symmetry of SOP on lines and planes of symmetry in one-electron Brillouin zone. In the case of highly symmetric UPt 3 only theoretical nodal structure of IR E 2u is in agreement with all the experimental results. On the other hand, in the case of high-T c superconductors the two electron description of Cooper pairs in D 2h symmetry is not sufficient to describe experimental nodal structure. It was shown that in this case, the nodal structure is the result of underlying interactions between two-electron states and hidden symmetry D-4 h . (author)

Nonlinear dielectric properties and tunability of 0.9Pb(Mg1/3,Nb2/3)O3-0.1 PbTiO3 and Ba(Ti0.85,Sn0.15)O3 paraelectrics

Science.gov (United States)

Akdogan, E. K.; Hall, A.; Simon, W. K.; Safari, A.

2007-01-01

We investigate the nonlinear dielectric properties of 0.9Pb(Mg1/3,Nb2/3)O3•0.1PbTiO3 (PMN-PT) and Ba[Ti0.85,Sn0.15]O3 (BTS) paraelectrics experimentally and theoretically. We measure the nonlinear dielectric response in the parallel plate capacitor configuration, whereby we obtain the low frequency linear permittivity (ε33), and the higher order permittivities (ε3333,ε333333) at 298K as ε33PMN-PT=2.1×10-7 and ε33BTS=4.1×10-8F /m, ε3333PMN-PT=-4.9×10-20 and ε3333BTS=-7.3×10-21F3m /C2, and ε333333PMN-PT=7.6×10-33 and ε333333BTS=9.85×10-34F5m3/C4. By using a self-consistent thermodynamic theory in conjunction with the experimental data, we compute the E3 dependence of electrostatic free energy ΔG, the field-induced polarization P3, and the thermodynamic tunability ∂2P3/∂E32, and prove that electrostatic free energy has to be expanded at least up to the sixth order in the electric field to define the critical field ∣E3*∣ at which maximum tunability is attained. We also show that ∣E3*∣ is a function on ∣ε3333∣/ε333333 only. Consequently, we find ∣E3*∣PMN-PT=8.0×105V /m and ∣E3*∣BTS=8.6×105V/m. We compute the engineering tunabilities as ΓPMN-PT=65% and ΓBTS=55%, and then define a normalized tunability ξ to take into account the ∣E3*∣ parameter. Thereof, we determine ∣ξ ∣PMT-PT=8.1×10-5%/Vm-1 and ∣ξ∣BTS=6.4×10-5%/Vm-1. Our results reveal that ∣E3*∣BTS>∣E3*∣PMN-PT although ΓBTS<ΓPMN-PT, unequivocally showing the need for defining a critical field parameter in evaluating the nonlinear dielectric response and tunability, in particular, and in nonlinear dielectrics in general. The results also indicate that the nonlinear dielectric properties of PMN-PT are an order of magnitude higher than that of BTS, which we discuss in the context of structure-property relations of relaxors.

A lateral cephalometric study of the size of tongue and intermaxillary space in Korean

International Nuclear Information System (INIS)

Lee, Sang Rae

1977-01-01

A study was performed to investigate the size of tongue area and intermaxillary space area, and compare the sexual differences between normal Korean children and adults by introducing planimetric and linear analysis of the lateral cephalograms. The cephalograms were composed of 41 child male aged 10.8, 40 child female aged 10.5, 38 adult male aged 21.3 , and 40 adult female aged 20.8 respectively. In order to study and measure the intermaxillary space area, the following were selected, as reference items: occlusal plane, anterior intermaxillary space height, posterior intermaxillary space height, length of intermaxillary space. Among those reference items anterior intermaxillary space height and posterior intermaxillary space height were perpendicular to the maxillary plane. An index, (Anterior intermaxillary space height + posterior intermaxillary space height )/2 Length of intermaxillary space, was introduced for the calculation of intermaxillary space area. While the tongue area was plotted by outline of tongue shadow, above a line extending from the vallecula to the most anterior point on the hyoid body, and above a line from the most anterior point of the hyoid body to the mention. The obtained results were as follows: 1. In general, the measurements of male were larger than those of female in intermaxillary space area in childhood and adulthood group. But intermaxillary space area of childhood group showed no significant sexual difference, and that of adulthood group showed significant sexual difference when evaluated statistically. 2. In both groups, the measurements of male were larger than those of female in tongue area, and there are also statistical significance of sexual differences in both age groups. 3. Considerable growth changes between the childhood and adulthood groups were revealed in intermaxillary space area an d tongue area, and the tongue had tendency to become relatively smaller when compared with the intermaxillary space in both sexes.

A lateral cephalometric study of the size of tongue and intermaxillary space in Korean

Energy Technology Data Exchange (ETDEWEB)

Lee, Sang Rae [Department of Dental Radiology, College of Dentistry, Kung Hee University, Seoul (Korea, Republic of)

1977-11-15

A study was performed to investigate the size of tongue area and intermaxillary space area, and compare the sexual differences between normal Korean children and adults by introducing planimetric and linear analysis of the lateral cephalograms. The cephalograms were composed of 41 child male aged 10.8, 40 child female aged 10.5, 38 adult male aged 21.3 , and 40 adult female aged 20.8 respectively. In order to study and measure the intermaxillary space area, the following were selected, as reference items: occlusal plane, anterior intermaxillary space height, posterior intermaxillary space height, length of intermaxillary space. Among those reference items anterior intermaxillary space height and posterior intermaxillary space height were perpendicular to the maxillary plane. An index, (Anterior intermaxillary space height + posterior intermaxillary space height)/2 Length of intermaxillary space, was introduced for the calculation of intermaxillary space area. While the tongue area was plotted by outline of tongue shadow, above a line extending from the vallecula to the most anterior point on the hyoid body, and above a line from the most anterior point of the hyoid body to the mention. The obtained results were as follows: 1. In general, the measurements of male were larger than those of female in intermaxillary space area in childhood and adulthood group. But intermaxillary space area of childhood group showed no significant sexual difference, and that of adulthood group showed significant sexual difference when evaluated statistically. 2. In both groups, the measurements of male were larger than those of female in tongue area, and there are also statistical significance of sexual differences in both age groups. 3. Considerable growth changes between the childhood and adulthood groups were revealed in intermaxillary space area an d tongue area, and the tongue had tendency to become relatively smaller when compared with the intermaxillary space in both sexes.

Student Perceptions of a 21st Century Learning Space

Science.gov (United States)

Adedokun, Omolola A.; Henke, Jacqueline N.; Parker, Loran Carleton; Burgess, Wilella D.

2017-01-01

Higher education institutions are increasingly building or remodeling classrooms to be flexible spaces that support learner-centered instruction. However, little is known about the actual impact of these spaces on student outcomes. Using a mixed method design, this study examined student perceptions of a flexible learning space on student learning…

Space astronomy for the mid-21st century: Robotically maintained space telescopes

Science.gov (United States)

Schartel, N.

2012-04-01

The historical development of ground based astronomical telescopes leads us to expect that space-based astronomical telescopes will need to be operational for many decades. The exchange of scientific instruments in space will be a prerequisite for the long lasting scientific success of such missions. Operationally, the possibility to repair or replace key spacecraft components in space will be mandatory. We argue that these requirements can be fulfilled with robotic missions and see the development of the required engineering as the main challenge. Ground based operations, scientifically and technically, will require a low operational budget of the running costs. These can be achieved through enhanced autonomy of the spacecraft and mission independent concepts for the support of the software. This concept can be applied to areas where the mirror capabilities do not constrain the lifetime of the mission. Online material is available at the CDS via http://cdsarc.u-strasbg.fr/cgi-bin/qcat?J/AN/333/209

Response to the Comment by G. Emch on projective group representations in quaternionic Hilbert space

International Nuclear Information System (INIS)

Adler, S.L.

1996-01-01

We discuss the differing definitions of complex and quaternionic projective group representations employed by us and by Emch. The definition of Emch (termed here a strong projective representation) is too restrictive to accommodate quaternionic Hilbert space embeddings of complex projective representations. Our definition (termed here a weak projective representation) encompasses such embeddings, and leads to a detailed theory of quaternionic, as well as complex, projective group representations. copyright 1996 American Institute of Physics

Computing Analysis of Bearing Elements of Launch Complex Aggregates for Space Rocket "Soyuz-2.1v"

Directory of Open Access Journals (Sweden)

V. A. Zverev

2014-01-01

Full Text Available The research is devoted to the computational analysis of bearing structures of launch system aggregates, which are designed for the prelaunch preparation and launch security of space rocket (SR "SOYUZ-2" of 1B stage. The bearing structures taken under consideration are the following: supporting trusses (ST, bearing arms (BA, the upper cable girder (UCG, the umbilical mast (UM. The SR “SOYUZ-2" of 1B stage has the characteristics of the propulsion unit (PU thrust, different from those of the "Soyuz" family space rockets exploited before.The paper presents basic modeling principles to calculate units and their operating loadings. The body self-weight and the influence of a gas-dynamic jet of "SOYUZ-2.1B" propulsion unit have been considered as a load of units. Parameters of this influence are determined on the basis of impulse stream fields and of deceleration temperatures calculated for various SR positions according to the specified path of its ascent and demolition.Physical models of the aggregates and calculations are based on the finite elements method and super-elements method using “SADAS” software package developed at the chair SM8 of Bauman Moscow State Technical University.Fields of nodal temperatures distribution in the ST, BA, UCG, UM models, and fields of tension in finite elements as well represent the calculation results.Obtained results revealed the most vulnerable of considered starting system aggregates, namely UM, which was taken for local durability calculation. As an example, this research considers calculation of local durability in the truss branches junction of UM rotary part, for which the constructive strengthening has been offered. For this node a detailed finite-element model built in the model of UM rotary part has been created. Calculation results of local durability testify that the strengthened node meets durability conditions.SR developers used calculation results of launch system aggregates for the space

Does the Health Impact of Exposure to Neighbourhood Green Space Differ between Population Groups? An Explorative Study in Four European Cities

Directory of Open Access Journals (Sweden)

Annemarie Ruijsbroek

2017-06-01

Full Text Available It has been suggested that certain residents, such as those with a low socioeconomic status, the elderly, and women, may benefit more from the presence of neighbourhood green space than others. We tested this hypothesis for age, gender, educational level, and employment status in four European cities. Data were collected in Barcelona (Spain; n = 1002, Kaunas (Lithuania; n = 989, Doetinchem (The Netherlands; n = 847, and Stoke-on-Trent (UK; n = 933 as part of the EU-funded PHENOTYPE project. Surveys were used to measure mental and general health, individual characteristics, and perceived neighbourhood green space. Additionally, we used audit data about neighbourhood green space. In Barcelona, there were positive associations between neighbourhood green space and general health among low-educated residents. In the other cities and for the other population groups, there was little evidence that the association between health and neighbourhood green space differed between population groups. Overall, our study does not support the assumption that the elderly, women, and residents who are not employed full-time benefit more from neighbourhood green space than others. Only in the highly urbanised city of Barcelona did the low-educated group benefit from neighbourhood green spaces. Perhaps neighbourhood green spaces are more important for the health of low-educated residents in particularly highly urbanised areas.

Gauge fields in nonlinear group realizations involving two-dimensional space-time symmetry

International Nuclear Information System (INIS)

Machacek, M.E.; McCliment, E.R.

1975-01-01

It is shown that gauge fields may be consistently introduced into a model Lagrangian previously considered by the authors. The model is suggested by the spontaneous breaking of a Lorentz-type group into a quasiphysical two-dimensional space-time and one internal degree of freedom, loosely associated with charge. The introduction of zero-mass gauge fields makes possible the absorption via the Higgs mechanism of the Goldstone fields that appear in the model despite the fact that the Goldstone fields do not transform as scalars. Specifically, gauge invariance of the Yang-Mills type requires the introduction of two sets of massless gauge fields. The transformation properties in two-dimensional space-time suggest that one set is analogous to a charge doublet that behaves like a second-rank tensor in real four-dimensional space time. The other set suggests a spin-one-like charge triplet. Via the Higgs mechanism, the first set absorbs the Goldstone fields and acquires mass. The second set remains massless. If massive gauge fields are introduced, the associated currents are not conserved and the Higgs mechanism is no longer fully operative. The Goldstone fields are not eliminated, but coupling between the Goldstone fields and the gauge fields does shift the mass of the antisymmetric second-rank-tensor gauge field components

Electric field control of magnetic states in isolated and dipole-coupled FeGa nanomagnets delineated on a PMN-PT substrate.

Science.gov (United States)

Ahmad, Hasnain; Atulasimha, Jayasimha; Bandyopadhyay, Supriyo

2015-10-09

We report observation of a 'non-volatile' converse magneto-electric effect in elliptical FeGa nanomagnets delineated on a piezoelectric PMN-PT substrate. The nanomagnets are first magnetized with a magnetic field directed along their nominal major axes. Subsequent application of a strong electric field across the piezoelectric substrate generates strain in the substrate, which is partially transferred to the nanomagnets and rotates the magnetizations of some of them away from their initial orientations. The rotated magnetizations remain in their new orientations after the field is removed, resulting in 'non-volatility'. In isolated nanomagnets, the magnetization rotates by <90° upon application of the electric field, but in a dipole-coupled pair consisting of one 'hard' and one 'soft' nanomagnet, which are both initially magnetized in the same direction by the magnetic field, the soft nanomagnet's magnetization rotates by [Formula: see text] upon application of the electric field because of the dipole influence of the hard nanomagnet. This effect can be utilized for a nanomagnetic NOT logic gate.

Topological and homological properties of the orbit space of a compact linear Lie group with commutative connected component

OpenAIRE

Styrt, O. G.

2016-01-01

The problem in question is whether the quotient space of a compact linear group is a topological manifold and whether it is a homological manifold. In the paper, the case of an infinite group with commutative connected component is considered.

Torelli groups, extended Johnson homomorphisms, and new cycles on the moduli space of curves

DEFF Research Database (Denmark)

Morita, Shigeyuki; Penner, Robert

modulo N are derived for all N. Furthermore, the first Johnson homomorphism, which is defined from the classical Torelli group to the third exterior power of the homology of the surface, is shown to lift to an explicit canonical 1-cocycle of the Teichmueller space. The main tool for these results...... cocycle lifts of the higher Johnson homomorphisms....

Immunohistochemical distribution of phosphatidylglucoside using anti-phosphatidylglucoside monoclonal antibody (DIM21)

International Nuclear Information System (INIS)

Kitamura, Yukisato; Okazaki, Toshiro; Nagatsuka, Yasuko; Hirabayashi, Yoshio; Kato, Shinsuke; Hayashi, Kazuhiko

2007-01-01

The immunohistochemical distribution of phosphatidylglucoside (PhGlc) in organs obtained from human autopsy cases was investigated using the DIM21 antibody. Immunohistochemical staining was performed on formaline-fixed, paraffin-embedded sections using the simple stain peroxidase method. The sections were then subjected to antigen retrieval by microwave irradiation in citrate buffer. PhGlc expression was observed in not only the epithelial but also the non-epithelial components of several visceral organs. Squamous and glandular epithelial cells were positive for PhGlc in several organs. The surface areas of the epithelium, particularly the squamous epithelium, were positive. Mesothelial cells were also positive in some organs. Endothelial cells, polymorphonuclear (PMN) cells are positive in several organs. Macrophage is positive in many organs. Epithelial cells of the gallbladder were positive, however, the intrahepatic bile ducts were not positive. In the brain tissue, astroglial cells, the chorioide plexus, the pituitary gland, and ependymal cells were positive. Further investigation is indispensable in order to establish a relationship between cell differentiation and PhGlc expression

EFSA Panel on Food Contact Materials, Enzymes, Flavourings and Processing Aids (CEF); Scientific Opinion on Flavouring Group Evaluation 21, Revision 3 (FGE.21Rev3): Thiazoles, thiophenes, thiazoline and thienyl derivatives from chemical groups 29 and 30

DEFF Research Database (Denmark)

Larsen, John Christian; Nørby, Karin Kristiane; Beltoft, Vibe Meister

The Panel on Food Contact Materials, Enzymes, Flavourings and Processing Aids of the European Food Safety Authority was requested to evaluate 59 flavouring substances in the Flavouring Group Evaluation 21, including an additional three substances in this Revision 3, using the Procedure in Commiss......The Panel on Food Contact Materials, Enzymes, Flavourings and Processing Aids of the European Food Safety Authority was requested to evaluate 59 flavouring substances in the Flavouring Group Evaluation 21, including an additional three substances in this Revision 3, using the Procedure.......086, 15.090, 15.099, 15.114, 15.119 and 15.133] were considered to have genotoxic potential. The remaining 52 substances were evaluated through a stepwise approach (the Procedure) that integrates information on structure-activity relationships, intake from current uses, toxicological threshold of concern.......092, 15.093, 15.094, 15.096, 15.097, 15.106, 15.107, 15.129 and 15.135] evaluated through the Procedure, no appropriate NOAEL was available and additional data are required. Besides the safety assessment of these flavouring substances, the specifications for the materials of commerce have also been...

Preparation of Lead Magnesium Niobate-Lead Zirconate Titanate Films and Their Crystallization Behaviors

International Nuclear Information System (INIS)

Tursiloadi, Silvester

2002-01-01

The thin films with composition near morpotropic phase boundary (MPB) of the system xPb(Mg 1 /3, Nb 2 /3) O 3 -yPbTiO 3 -zPbZrO 3 (x = 0-0.35, y = 0.47 and z = 0.53), were prepared by sol-gel method. The starting materials were consisted of Pb(iso-OC 3 H 7 ) 2 , Zr(n-OC 4 H 9 ) 4 , Ti(iso-OC 3 H 7 ) 4 , Mg(CH 3 COO) 2 4H 2 O and Nb(OC 2 H 5 ) 5 . The l-propanol was used as solvent. The concentration of PMN-PT-PZ in coating solution was 0.7 M, and the pH of the solution was 4.5. The thin films were prepared by dip coating and spin coating. The crystallization behaviors of the PMN-PT-PZ thin films showed that the formation of perovskite phase at low temperature becomes difficult with increasing the content of PMN. The amounts of pyrochlore and perovskite phase in PMN-PT-PZ films depended on the heating temperatures, and PMN contents. Single-phase perovskite was found for the coated films containing 0 and 12.5 mol% after calculating at 600 o C, 21 mol% after calculating at 700 o C, and 30 mol% after calculating at 750 o C. Single-phase perovskite of coated films will never be found when the content of PMN was 35 mol%

On the Lie symmetry group for classical fields in noncommutative space

Energy Technology Data Exchange (ETDEWEB)

Pereira, Ricardo Martinho Lima Santiago [Universidade Federal da Bahia (UFBA), BA (Brazil); Instituto Federal da Bahia (IFBA), BA (Brazil); Ressureicao, Caio G. da [Universidade Federal da Bahia (UFBA), BA (Brazil). Inst. de Fisica; Vianna, Jose David M. [Universidade Federal da Bahia (UFBA), BA (Brazil); Universidade de Brasilia (UnB), DF (Brazil)

2011-07-01

Full text: An alternative way to include effects of noncommutative geometries in field theory is based on the concept of noncommutativity among degrees of freedom of the studied system. In this context it is reasonable to consider that, in the multiparticle noncommutative quantum mechanics (NCQM), the noncommutativity among degrees of freedom to discrete system with N particles is also verified. Further, an analysis of the classical limit of the single particle NCQM leads to a deformed Newtonian mechanics where the Newton's second law is modified in order to include the noncommutative parameter {theta}{sub {iota}j} and, for a one-dimensional discrete system with N particles, the dynamical evolution of each particle is given by this modified Newton's second law. Hence, applying the continuous limit to this multiparticle classical system it is possible to obtain a noncommutative extension of two -dimensional field theory in a noncommutative space. In the present communication we consider a noncommutative extension of the scalar field obtained from this approach and we analyze the Lie symmetries in order to compare the Lie group of this field with the usual scalar field in the commutative space. (author)

Implementation of rigorous renormalization group method for ground space and low-energy states of local Hamiltonians

Science.gov (United States)

Roberts, Brenden; Vidick, Thomas; Motrunich, Olexei I.

2017-12-01

The success of polynomial-time tensor network methods for computing ground states of certain quantum local Hamiltonians has recently been given a sound theoretical basis by Arad et al. [Math. Phys. 356, 65 (2017), 10.1007/s00220-017-2973-z]. The convergence proof, however, relies on "rigorous renormalization group" (RRG) techniques which differ fundamentally from existing algorithms. We introduce a practical adaptation of the RRG procedure which, while no longer theoretically guaranteed to converge, finds matrix product state ansatz approximations to the ground spaces and low-lying excited spectra of local Hamiltonians in realistic situations. In contrast to other schemes, RRG does not utilize variational methods on tensor networks. Rather, it operates on subsets of the system Hilbert space by constructing approximations to the global ground space in a treelike manner. We evaluate the algorithm numerically, finding similar performance to density matrix renormalization group (DMRG) in the case of a gapped nondegenerate Hamiltonian. Even in challenging situations of criticality, large ground-state degeneracy, or long-range entanglement, RRG remains able to identify candidate states having large overlap with ground and low-energy eigenstates, outperforming DMRG in some cases.

Temperature Increase during Different Post Space Preparation Systems: An In Vitro Study.

Science.gov (United States)

Nazari Moghadam, Kiumars; Shahab, Shahriar; Shirvani, Soghra; Kazemi, Ali

2011-01-01

  The purpose of this study was to evaluate external root surface temperature rise during post space preparation using LA Axxess bur, Beefill pack System, and Peeso Reamer drill. The distal canals of forty-five extracted human permanent mandibular first molars were instrumented in crown-apical manner and obturated with lateral condensation technique. Teeth were then randomly divided into three groups according to post space preparation technique including: group 1. LA Axxess bur (Sybronendo Co., CA, USA), group 2 Beefill pack System (VD W Co., Munich, Germany) and group 3 Peeso Reamer drill (Mani Co., Tochigi-ken, Japan). Temperature was measured by means of digital thermometer MT-405 (Comercio Co., Sao Paulo, Brazil) which was installed on the root surfaces. Data was collected and submitted to one-way ANOVA and Post hoc analysis. Root surface temperatures were found to be significantly higher (7.3±2.7 vs. 4.3±2.1 and 4±2.4,) in samples of Beefill pack System compared with the two other groups (P<0.02). Using Beefill pack System during post space preparation may be potentially hazardous for periodontal tissues.

A Topic Space Oriented User Group Discovering Scheme in Social Network: A Trust Chain Based Interest Measuring Perspective

Directory of Open Access Journals (Sweden)

Wang Dong

2016-01-01

Full Text Available Currently, user group has become an effective platform for information sharing and communicating among users in social network sites. In present work, we propose a single topic user group discovering scheme, which includes three phases: topic impact evaluation, interest degree measurement, and trust chain based discovering, to enable selecting influential topic and discovering users into a topic oriented group. Our main works include (1 an overview of proposed scheme and its related definitions; (2 topic space construction method based on topic relatedness clustering and its impact (influence degree and popularity degree evaluation; (3 a trust chain model to take user relation network topological information into account with a strength classification perspective; (4 an interest degree (user explicit and implicit interest degree evaluation method based on trust chain among users; and (5 a topic space oriented user group discovering method to group core users according to their explicit interest degrees and to predict ordinary users under implicit interest and user trust chain. Finally, experimental results are given to explain effectiveness and feasibility of our scheme.

The Impact of Group Size on Welfare Indicators of Ewes during Pregnancy

Science.gov (United States)

Averós, Xavier; Beltrán de Heredia, Ignacia; Ruiz, Roberto; Estevez, Inma

2016-01-01

Group size (GS) and space allowance have major implications for the welfare of production species, however their effects are often confounded. In a previous study we investigated the impact of varying space allowance at constant GS. In the present work we report the consequences of varying GS on pregnant ewes while controlling space allowance. We housed ewes at 6 (GS6) or 12 ewes/enclosure (GS12), while controlling space allowance to 1.5 m2/ewe (3 enclosures/treatment), and necessarily varying enclosure size. Therefore, when indicating GS effects we implicitly reflect a confounding effect with that of enclosure size. Movement, use of space, behaviour, serum cortisol concentration and body condition score (BCS) were collected during the last 12 gestation weeks. Movement, use of space, and behaviour were collected every other week, during 2 days/week, using 10 minute continuous scan samplings. Blood was collected during weeks 10, 13, 17, and 21 of gestation, and BCS during weeks 15 and 21. Data were analysed using repeated measures, generalized linear mixed models, with GS, week, and their interaction as fixed effects, and enclosure as random effect. GS mainly affected movement and use of space. GS12 ewes walked longer distances using longer steps (Pewe is given during gestation, larger GS will result in larger effective space, and no major implications for the welfare of ewes should be expected as GS increases. Ewes will adapt their movement patterns and use of space to enclosure size, and no further behavioural, physiological and physical consequences should be expected. PMID:27893817

Moduli space of self-dual connections in dimension greater than four for abelian Gauge groups

OpenAIRE

Cappelle, Natacha

2018-01-01

In 1954, C. Yang and R. Mills created a Gauge Theory for strong interaction of Elementary Particles. More generally, they proved that it is possible to define a Gauge Theory with an arbitrary compact Lie group as Gauge group. Within this context, it is interesting to find critical values of a functional defined on the space of connections: the Yang-Mills functional. If the based manifold is four dimensional, there exists a natural notion of (anti-)self-dual 2-form, which gives a natural notio...

Cubic scattering amplitudes for all massless representations of the Poincare group in any space-time dimension

International Nuclear Information System (INIS)

Fradkin, E.S.; Metsaev, R.R.

1996-02-01

Using the language of highest weight representations and the light cone formalism we construct a full list of cubic amplitudes of scattering for all bosonic massless representations of the Poincare group in any even space-time dimension. (author). 29 refs

USSR Space Life Sciences Digest, issue 21

Science.gov (United States)

Hooke, Lydia Razran; Donaldson, P. Lynn; Garshnek, Victoria; Rowe, Joseph

1989-01-01

This is the twenty-first issue of NASA's USSR Space Life Sciences Digest. It contains abstracts of 37 papers published in Russian language periodicals or books or presented at conferences and of a Soviet monograph on animal ontogeny in weightlessness. Selected abstracts are illustrated with figures and tables from the original. A book review of a work on adaptation to stress is also included. The abstracts in this issue have been identified as relevant to 25 areas of space biology and medicine. These areas are: adaptation, biological rhythms, body fluids, botany, cardiovascular and respiratory systems, cytology, developmental biology, endocrinology, enzymology, equipment and instrumentation, exobiology, gravitational biology, habitability and environmental effects, hematology, human performance, life support systems, mathematical modeling, metabolism, microbiology, musculoskeletal system, neurophysiology, operational medicine, perception, psychology, and reproductive system.

14 CFR 21.139 - Quality control.

Science.gov (United States)

2010-01-01

... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Quality control. 21.139 Section 21.139... PROCEDURES FOR PRODUCTS AND PARTS Production Certificates § 21.139 Quality control. The applicant must show that he has established and can maintain a quality control system for any product, for which he...

Clifford algebras, spinors, spin groups and covering groups

International Nuclear Information System (INIS)

Magneville, C.; Pansart, J.P.

1991-03-01

The Dirac equation uses matrices named Υ matrices which are representations of general algebraic structures associated with a metric space. These algebras are the Clifford algebras. In the first past, these algebras are studied. Then the notion of spinor is developed. It is shown that Majorana and Weyl spinors only exist for some particular metric space. In the second part, Clifford and spinor groups are studied. They may be interpreted as the extension of the notion of orthogonal group for Clifford algebras and their spaces for representation. The rotation of a spinor is computed. In the last part, the connexion between the spinor groups and the Universal Covering Groups is presented [fr

Penetration effect of prostaglandin E2 gel on oral mucosa of rats

Directory of Open Access Journals (Sweden)

Rafinus Arifin

2012-09-01

Full Text Available Background: Several researches reported that Prostaglandin E2 (PGE2 injection on buccal mucosa combined with orthodontic pressure can faster tooth movement but has disadvantages such as high alveolar bone and root resorption furthermore pain from injection needle. PGE2 gel was made to better replace the lacks of injectable PGE2. Purpose: This research was aimed to prove that PGE 2 gel can penetrate rat’s oral mucosa effecting the appearance of PMN cells. Methods: This research was an in vivo laboratory experiment using 36 Sprague Dawley rats which were divided into 3 groups: normal group, topical PGE2 gel group after 1, 2, 4, 8 hours (4 subgroups, and topical gel without PGE2 group after 1, 2, 4, 8 hours (4 subgroups. Each group consists of 4 rats, therefore the total sample for all research groups were 36 rats. Gel with 25 µg/mL of PGE2 and gel without PGE2 were applied on oral mucosa for 2 minutes. Then, the rats were sacrificed after 1 hour, 2 hours, 4 hours, and 8 hours application. After that, the samples were prepared for histological examination with Hematoxyllin and Eosin. The picture were taken with OptiLab View and PMN cells amount were counted with light microscope, set 400 times of magnification. Results: Penetration effect of PGE2 gel on rat’s oral mucosa result in PMN inflammation cells distribution. One-way ANOVA showed no significant difference on PMN cells count in rats’ lower jaws between groups of normal and gel without PGE2. There was significant difference between groups of PGE2 gel and gel without PGE2 (p=0,001. PGE2 gel application showed PGE2 as inflammatory media, even though administered topically. Conclusion: PGE2 gel can penetrate rat’s oral mucosa, effecting PMN cells 1, 2, 4 and 8 hours after application of PGE2 gel.Latar belakang: Beberapa penelitian melaporkan bahwa injeksi (Prostaglandin E2 PGE2pada mukosa bukal yang dikombinasikan dengan tekanan ortodonti dapat mempercepat pergerakan gigi, tapi

The Group Evacuation Behavior Based on Fire Effect in the Complicated Three-Dimensional Space

Directory of Open Access Journals (Sweden)

Jun Hu

2014-01-01

Full Text Available In order to effectively depict the group evacuation behavior in the complicated three-dimensional space, a novel pedestrian flow model is proposed with three-dimensional cellular automata. In this model the calculation methods of floor field and fire gain are elaborated at first, and the transition gain of target position at the next moment is defined. Then, in consideration of pedestrian intimacy and velocity change, the group evacuation strategy and evolution rules are given. Finally, the experiments were conducted with the simulation platform to study the relationships of evacuation time, pedestrian density, average system velocity, and smoke spreading velocity. The results had shown that large-scale group evacuation should be avoided, and in case of large pedestrian density, the shortest route of evacuation strategy would extend system evacuation time.

14 CFR 21.147 - Changes in quality control system.

Science.gov (United States)

2010-01-01

... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Changes in quality control system. 21.147 Section 21.147 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION... quality control system. After the issue of a production certificate, each change to the quality control...

14 CFR 420.21 - Launch site location review-launch site boundary.

Science.gov (United States)

2010-01-01

... 14 Aeronautics and Space 4 2010-01-01 2010-01-01 false Launch site location review-launch site boundary. 420.21 Section 420.21 Aeronautics and Space COMMERCIAL SPACE TRANSPORTATION, FEDERAL AVIATION... travels given a worst-case launch vehicle failure in the launch area. An applicant must clearly and...

Quantum spaces, central extensions of Lie groups and related quantum field theories

Science.gov (United States)

Poulain, Timothé; Wallet, Jean-Christophe

2018-02-01

Quantum spaces with su(2) noncommutativity can be modelled by using a family of SO(3)-equivariant differential *-representations. The quantization maps are determined from the combination of the Wigner theorem for SU(2) with the polar decomposition of the quantized plane waves. A tracial star-product, equivalent to the Kontsevich product for the Poisson manifold dual to su(2) is obtained from a subfamily of differential *-representations. Noncommutative (scalar) field theories free from UV/IR mixing and whose commutative limit coincides with the usual ϕ 4 theory on ℛ3 are presented. A generalization of the construction to semi-simple possibly non simply connected Lie groups based on their central extensions by suitable abelian Lie groups is discussed. Based on a talk presented by Poulain T at the XXVth International Conference on Integrable Systems and Quantum symmetries (ISQS-25), Prague, June 6-10 2017.

Extreme covariant quantum observables in the case of an Abelian symmetry group and a transitive value space

International Nuclear Information System (INIS)

Haapasalo, Erkka Theodor; Pellonpaeae, Juha-Pekka

2011-01-01

We represent quantum observables as normalized positive operator valued measures and consider convex sets of observables which are covariant with respect to a unitary representation of a locally compact Abelian symmetry group G. The value space of such observables is a transitive G-space. We characterize the extreme points of covariant observables and also determine the covariant extreme points of the larger set of all quantum observables. The results are applied to position, position difference, and time observables.

Multiple Group Confirmatory Factor Analysis of the DASS-21 Depression and Anxiety Scales: How Do They Perform in a Cancer Sample?

Science.gov (United States)

Fox, Rina S; Lillis, Teresa A; Gerhart, James; Hoerger, Michael; Duberstein, Paul

2018-06-01

The DASS-21 is a public domain instrument that is commonly used to evaluate depression and anxiety in psychiatric and community populations; however, the factor structure of the measure has not previously been examined in oncologic settings. Given that the psychometric properties of measures of distress may be compromised in the context of symptoms related to cancer and its treatment, the present study evaluated the psychometric properties of the DASS-21 Depression and Anxiety scales in cancer patients ( n = 376) as compared to noncancer control participants ( n = 207). Cancer patients ranged in age from 21 to 84 years (mean = 58.3, standard deviation = 10.4) and noncancer control participants ranged in age from 18 to 81 years (mean = 45.0, standard deviation = 11.7). Multiple group confirmatory factor analysis supported the structural invariance of the DASS-21 Depression and Anxiety scales across groups; the factor variance/covariance invariance model was the best fit to the data. Cronbach's coefficient alpha values demonstrated acceptable internal consistency reliability across the total sample as well as within subgroups of cancer patients and noncancer control participants. Expected relationships of DASS-21 Depression and Anxiety scale scores to measures of suicidal ideation, quality of life, self-rated health, and depressed mood supported construct validity. These results support the psychometric properties of the DASS-21 Depression and Anxiety scales when measuring psychological distress in cancer patients.

Hybrid Electrostatic/Flextensional Mirror for Lightweight, Large-Aperture, and Cryogenic Space Telescopes

Science.gov (United States)

Patrick, Brian; Moore, James; Hackenberger, Wesley; Jiang, Xiaoning

2013-01-01

A lightweight, cryogenically capable, scalable, deformable mirror has been developed for space telescopes. This innovation makes use of polymer-based membrane mirror technology to enable large-aperture mirrors that can be easily launched and deployed. The key component of this innovation is a lightweight, large-stroke, cryogenic actuator array that combines the high degree of mirror figure control needed with a large actuator influence function. The latter aspect of the innovation allows membrane mirror figure correction with a relatively low actuator density, preserving the lightweight attributes of the system. The principal components of this technology are lightweight, low-profile, high-stroke, cryogenic-capable piezoelectric actuators based on PMN-PT (piezoelectric lead magnesium niobate-lead titanate) single-crystal configured in a flextensional actuator format; high-quality, low-thermal-expansion polymer membrane mirror materials developed by NeXolve; and electrostatic coupling between the membrane mirror and the piezoelectric actuator assembly to minimize problems such as actuator print-through.

14 CFR 21.31 - Type design.

Science.gov (United States)

2010-01-01

... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Type design. 21.31 Section 21.31... PROCEDURES FOR PRODUCTS AND PARTS Type Certificates § 21.31 Type design. The type design consists of— (a) The... configuration and the design features of the product shown to comply with the requirements of that part of this...

Space Ethics and Protection of the Space Environment

Science.gov (United States)

Williamson, Mark

2002-01-01

The construction of the International Space Station in low Earth orbit and the formulation of plans to search for life on Mars - one day by means of manned missions - indicate that mankind is intent on making the space environment part of its domain. Publicity surrounding space tourism, in-space `burials' and the sale of lunar `real estate' suggests that, some time in the 21st century, the space environment will become an extraterrestrial extension of our current business and domestic environment. This prompts the question of our collective attitude towards the space environment and the degree to which we should regulate its use and protect it for future generations. What, indeed, are the ethical considerations of space exploration and development? Ethics can be defined as "the philosophical study of the moral value of human conduct, and of the rules or principles that ought to govern it". More practically, it represents "an approved code of behaviour" adopted, for example, by a group or profession. If a set of ethics is to be developed for space, it is important that what we refer to as the `space community', or `space profession', is intimately involved. Indeed, if it is not, the profession risks having the job done for it, for example by politicians and members of the general public, who for their own reasons may wish to place restrictions on space development, or ban it altogether. The terrestrial nuclear power industry, for example, has already suffered this fate, while widespread ignorance of the subject has led to a moratorium on the use of RTGs in spacecraft. However, there is a danger in the discussion of ethics that consideration is confined to the philosophical aspects, thus excusing those involved from providing practical solutions to the problems that emerge. The fact that mankind has already affected, and arguably damaged, the space environment transports the discussion beyond the philosophical realm. This paper offers a pragmatic analysis of one

Effects of topical vitamin E on corneal superoxide dismutase, glutathione peroxidase activities and polymorphonuclear leucocyte infiltration after photorefractive keratectomy.

Science.gov (United States)

Bilgihan, Ayse; Bilgihan, Kamil; Yis, Ozgür; Sezer, Cem; Akyol, Gülen; Hasanreisoglu, Berati

2003-04-01

Photorefractive keratectomy (PRK) induces free radical formation and polymorphonuclear (PMN) cell infiltration in the cornea. Vitamin E is a free radical scavenger and protects the cells from reactive oxygen species. We investigated the effects of topical vitamin E on corneal PMN cell infiltration and corneal antioxidant enzyme activities after PRK. We studied four groups, each consisting of seven eyes. Group 1 were control eyes. In group 2 the corneal epithelium was removed by a blunt spatula (epithelial scrape). In group 3, corneal photoablation (59 micro m, 5 dioptres) was performed after epithelial removal (traditional PRK). In group 4 we tested the effects of topical Vitamin E after traditional PRK. Corneal tissues were removed and studied with enzymatic analysis (measurement of corneal superoxide dismutase and glutathione peroxidase activities) and histologically. Stromal PMN leucocyte counts were significantly higher after mechanical epithelial removal and traditional PRK (p < 0.05). Corneal superoxide dismutase and glutathione peroxidase activities decreased significantly after mechanical epithelial removal and traditional PRK (p < 0.05). In group 4, treated with vitamin E, corneal superoxide dismutase activity did not differ significantly from that in the medically non-treated groups, nor did corneal PMN cell infiltration after traditional PRK. The reduction of corneal glutathione peroxidase activity after PRK was reduced significantly after topical vitamin E treatment. Topical vitamin E treatment may be useful for reducing the harmful effects of reactive oxygen radical after epithelial scraping and PRK in that it increases corneal glutathione peroxidase activity.

Incubation of human blood fractions leads to changes in apparent miRNA abundance

DEFF Research Database (Denmark)

Skovgaard, Kerstin; Jørgensen, Stine Thuen; Heegaard, Peter M. H.

in significant changes in the abundance of miR-21, miR-155, Let-7c and Let 7f in plasma, miR-21, miR-23a and miR-150 in RBC and miR-15b, miR-126, miR155 and Let-7g in PBMC, while no change was seen in PRP and PMN. Interestingly, in the samples incubated with glass beads, no miRNAs were significantly affected...... in plasma, RBC, PBMC and PMN, while expression of miR-25, miR15a, miR-126 and miR223 was significantly changed in PRP. Thus, PRP, as the only blood fraction depended on stimulation to change its miRNA profile upon incubation. For the other fractions, stimulation either leveled out the changes induced...

Creating social spaces to tackle AIDS-related stigma: reviewing the role of church groups in Sub-Saharan Africa.

Science.gov (United States)

Campbell, C; Skovdal, M; Gibbs, A

2011-08-01

An expanding body of literature explores the role of African church groups in facilitating or hindering the support of people living with AIDS and challenging or contributing to HIV/AIDS-related stigma. Treating church groups as social spaces in which HIV/AIDS-related stigma may potentially be challenged, we systematically review this literature, identifying five themes that highlight the complex and contradictory role of the church as a potential agent of health-enhancing social change. In many ways the church perpetuates HIV/AIDS-related stigma through (i) moralistic attitudes and (ii) its reinforcement of conservative gender ideologies. However some churches have managed move towards action that makes a more positive contribution to HIV/AIDS management through (iii) promoting various forms of social control for HIV prevention, (iv) contributing to the care and support of the AIDS-affected and (v) providing social spaces for challenging stigmatising ideas and practices. We conclude that church groups, including church leadership, can play a key role in facilitating or hindering the creation of supportive social spaces to challenge stigma. Much work remains to be done in developing deeper understandings of the multi-layered factors that enable some churches, but not others, to respond effectively to HIV/AIDS.

基于MUSIC-Group Delay算法的相邻相干信号源定位%Closely spaced coherent-source localization based on MUSIC-group delay algorithm

Institute of Scientific and Technical Information of China (English)

郑家芝

2016-01-01

为了准确的进行相邻的相干信号源定位，提出了一种基于多重信号分类群延迟(MUSIC-group delay)的改进算法。首先，将空间平滑技术引入到波达方向(DoA)估计当中去除部分相干信号。由于在信号源相邻的情况下子空间算法的性能降低，就结合了 MUSIC-Group Delay算法来区分相邻的信号源，这种方法因为自身的加和性通过 MUSIC 相位谱来计算群延迟函数，从而能估计出相邻的信号源。理论分析和仿真结果表明提出的方法估计相邻的相干信号源比子空间算法更精确，分辨率更高。%In this paper,the closely spaced coherent-source localization is considered,and an improved method based on the group delay of Multiple Signal Classification (MUSIC)is presented.Firstly,we introduce the spatial smoothing technique into direction of arrival (DoA)estimation to get rid of the coherent part of signals.Due to the degraded per-formance of sub-space based methods on the condition of nearby sources,we then utilize the MUSIC-Group Delay algo-rithm to distinguish the closely spaced sources,which can resolve spatially close sources by the use of the group delay function computed from the MUSIC phase spectrum for efficient DoA estimation owing to its spatial additive property. Theoretical analysis and simulation results demonstrate that the proposed approach can estimate the DoA of the coherent close signal sources more precisely and have higher resolution compared with sub-space based methods.

Group vector space method for estimating enthalpy of vaporization of organic compounds at the normal boiling point.

Science.gov (United States)

Wenying, Wei; Jinyu, Han; Wen, Xu

2004-01-01

The specific position of a group in the molecule has been considered, and a group vector space method for estimating enthalpy of vaporization at the normal boiling point of organic compounds has been developed. Expression for enthalpy of vaporization Delta(vap)H(T(b)) has been established and numerical values of relative group parameters obtained. The average percent deviation of estimation of Delta(vap)H(T(b)) is 1.16, which show that the present method demonstrates significant improvement in applicability to predict the enthalpy of vaporization at the normal boiling point, compared the conventional group methods.

Fabrication of a PMN-PT Single Crystal-Based Transcranial Doppler Transducer and the Power Regulation of Its Detection System

Directory of Open Access Journals (Sweden)

Qingwen Yue

2014-12-01

Full Text Available Doppler sonographic measurement of flow velocity in the basal cerebral arteries through the intact skull was developed using a pulsed Doppler technique and 2 MHz emitting frequency. Relaxor-based ferroelectric single crystals Pb(Mg1/3Nb2/3O3-PbTiO3 (PMN-PT were chosen to be the piezoelectric transducer material due to their ultrahigh piezoelectric coefficients, high electromechanical coupling coefficients and low dielectric loss. The pulse-echo response of the transducer was measured using the conventional pulse-echo method in a water bath at room temperature. The −6 dB bandwidth of the transducer is 68.4% and the sensitivity is −17.4 dB. In order to get a good match between transducer and detection system, different transmission powers have been regulated by changing the impedance of the transmitting electric circuit. In the middle cerebral artery (MCA measurement photograph results, as the transmission power is increasing, the detection results become clearer and clearer. A comparison at the same transmission power for different transducers shows that the detection photograph obtained by the crystal transducer was clearer than that obtained with a commercial transducer, which should make it easier for doctors to find the cerebral arteries.

Leukotriene B4 (LTB4) induces formation of inositol-phosphates (IP's) in rat peritoneal polymorphonuclear leukocytes (PMN's)

International Nuclear Information System (INIS)

Chi-Rosso, G.; Crooke, S.T.; Mong, S.

1986-01-01

LTB 4 induced rapid breakdown of prelabeled inositol-phospholipids (PI) in rat PMN. Formation of [ 3 H]-inositol-trisphosphate ([ 3 H]-IP 3 ) was rapid, with a peak of 250-300% of the control level, after 5-15 sec of stimulation with LTB 4 . Accumulation of [ 3 H]-inositol-bisphosphate ([ 3 H]-IP 2 ) was rapid, peaking after 30 sec of stimulation. [ 3 H]-inositol-monophosphate ([ 3 H]-IP 1 ) accumulated gradually in the presence of LiCl. The kinetics of [ 3 H]-IP 3 , [ 3 H]-IP 2 and [ 3 H]-IP 1 accumulation suggested that LTB 4 may interact with receptors in PMNs, activate phospholipase C which, in turn, induces hydrolysis of PI. The agonist activities of several LTB 4 analogs were employed to investigate the structure activity relationship of LTB 4 receptor mediated activation of PI hydrolysis. Increases in [ 3 H]-IP 3 formation were dependent upon the concentration of LTB 4 and the agonist analogs. The rank order potency of these analogs were equivalent to that of the pharmacological activity of LTB 4 agonists in the chemotaxis assay. Furthermore, the Islet activation protein (IAP) inhibited LTB 4 induced [ 3 H]-IP 3 formation. The tumor promoting phorbomyristate ester also inhibited LTB 4 induced [ 3 H]-IP 3 formation. These results suggest LTB 4 may interact with receptors in rat PMNs, activate G/sub i/ protein regulated phospholipase C and induce [ 3 H]-IP 3 formation

Knot wormholes and the dimensional invariant of exceptional Lie groups and Stein space hierarchies

International Nuclear Information System (INIS)

Elokaby, Ayman

2009-01-01

The present short note points out a most interesting and quite unexpected connection between the number of distinct knot as a function of their crossing number and exceptional Lie groups and Stein space hierarchies. It is found that the crossing number 7 plays the role of threshold similar to 4 and 5 in E-infinity theory and for the 11 crossing the number of distinct knots is very close to 4α-bar 0 +1=548+1=549, where α-bar 0 =137 is the inverse integer electromagnetic fine structure constant. This is particularly intriguing in view of a similar relation pertinent to the 17 two and three Stein spaces where the total dimension is Σ 1 17 Stein=5α-bar 0 +1=685+1=686, as well as the sum of the eight exceptional Lie symmetry groups Σ i=1 8 |E i |=4α-bar 0 =548. The slight discrepancy of one is explained in both cases by the inclusion of El Naschie's transfinite corrections leading to Σ i=1 8 |E i |=(4)(137+k 0 )=548.328157 and Σ i=1 17 Stein=(5)(137+k 0 )=685.41097, where k o = φ 5 (1 - φ 5 ) and φ=(√(5)-1)/2.

Geometric group theory

CERN Document Server

Druţu, Cornelia

2018-01-01

The key idea in geometric group theory is to study infinite groups by endowing them with a metric and treating them as geometric spaces. This applies to many groups naturally appearing in topology, geometry, and algebra, such as fundamental groups of manifolds, groups of matrices with integer coefficients, etc. The primary focus of this book is to cover the foundations of geometric group theory, including coarse topology, ultralimits and asymptotic cones, hyperbolic groups, isoperimetric inequalities, growth of groups, amenability, Kazhdan's Property (T) and the Haagerup property, as well as their characterizations in terms of group actions on median spaces and spaces with walls. The book contains proofs of several fundamental results of geometric group theory, such as Gromov's theorem on groups of polynomial growth, Tits's alternative, Stallings's theorem on ends of groups, Dunwoody's accessibility theorem, the Mostow Rigidity Theorem, and quasiisometric rigidity theorems of Tukia and Schwartz. This is the f...

Space, time and group identity in Jubilees 8-9

African Journals Online (AJOL)

p1243322

This paper investigates this change in communication strategy and ... his orientation towards and organisation of space, as revealed in his ideas ..... two versions of the same tradition or the parallel development of an older, .... In the case of Numbers Israel ... with its chronological system of jubilees and heavenly space.

Classifying spaces with virtually cyclic stabilizers for linear groups

DEFF Research Database (Denmark)

Degrijse, Dieter Dries; Köhl, Ralf; Petrosyan, Nansen

2015-01-01

We show that every discrete subgroup of GL(n, ℝ) admits a finite-dimensional classifying space with virtually cyclic stabilizers. Applying our methods to SL(3, ℤ), we obtain a four-dimensional classifying space with virtually cyclic stabilizers and a decomposition of the algebraic K-theory of its...

14 CFR 120.21 - Testing for alcohol.

Science.gov (United States)

2010-01-01

... 14 Aeronautics and Space 3 2010-01-01 2010-01-01 false Testing for alcohol. 120.21 Section 120.21... AND OPERATORS FOR COMPENSATION OR HIRE: CERTIFICATION AND OPERATIONS DRUG AND ALCOHOL TESTING PROGRAM Air Traffic Controllers § 120.21 Testing for alcohol. (a) Each air traffic control facility not...

Local application of zoledronate for maximum anchorage during space closure.

Science.gov (United States)

Ortega, Adam J A J; Campbell, Phillip M; Hinton, Robert; Naidu, Aparna; Buschang, Peter H

2012-12-01

Orthodontists have used various compliance-dependent physical means such as headgears and intraoral appliances to prevent anchorage loss. The aim of this study was to determine whether 1 local application of the bisphosphonate zoledronate could be used to prevent anchorage loss during extraction space closure in rats. Thirty rats had their maxillary left first molars extracted and their maxillary left second molars protracted into the extraction space with a 10-g nickel-titanium closing coil for 21 days. Fifteen control rats received a local injection of phosphate-buffered saline solution, and 15 experimental rats received 16 μg of the bisphosphonate zoledronate. Bisphosphonate was also delivered directly into the extraction site and left undisturbed for 5 minutes. Cephalograms and incremental thickness gauges were used to measure tooth movements. Tissues were analyzed by microcomputed tomography and histology. The control group demonstrated significant (P <0.05) tooth movements throughout the 21-day period. They showed significantly greater tooth movements than the experimental group beginning in the second week. The experimental group showed no significant tooth movement after the first week. The microcomputed tomography and histologic observations showed significant bone loss in the extraction sites and around the second molars of the controls. In contrast, the experimental group had bone preservation and bone fill. There was no evidence of bisphosphonate-associated osteonecrosis in any sample. A single small, locally applied dose of zoledronate provided maximum anchorage and prevented significant bone loss. Copyright © 2012 American Association of Orthodontists. Published by Mosby, Inc. All rights reserved.

Birth spacing of pregnant women in Nepal: A community-based study

Directory of Open Access Journals (Sweden)

Rajendra Karkee

2016-09-01

Full Text Available BackgroundOptimal birth spacing has health advantages for both mother and child. In developing countries, shorter birth intervals are common and associated with social, cultural and economic factors, as well as a lack of family planning. This study investigated the first birth interval after marriage and preceding interbirth interval in Nepal.MethodsA community-based prospective cohort study was conducted in the Kaski district of Nepal. Information on birth spacing, demographic and obstetric characteristics was obtained from 701 pregnant women using a structured questionnaire. Logistic regression analyses were performed to ascertain factors associated with short birth spacing.ResultsAbout 39% of primiparous women gave their first child birth within one year of marriage and 23% of multiparous women had short preceding interbirth intervals (<24 months. The average birth spacing among the multiparous group was 44.9 (SD 21.8 months. Overall, short birth spacing appeared to be inversely associated with advancing maternal age.For the multiparous group, Janajati and lower caste women, and those whose newborn was female, were more likely to have short birth spacing.ConclusionsThe preceding interbirth interval was relatively long in the Kaski district of Nepal and tended to be associated with maternal age, caste, and sex of newborn infant. Optimal birth spacing programs should target Janajati and lower caste women, along with promotion of gender equality in society.

14 CFR 21.53 - Statement of conformity.

Science.gov (United States)

2010-01-01

... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Statement of conformity. 21.53 Section 21... CERTIFICATION PROCEDURES FOR PRODUCTS AND PARTS Type Certificates § 21.53 Statement of conformity. Link to an... conformity (FAA Form 317) to the Administrator for each aircraft engine and propeller presented to the...

WORKSHOP: Inner space - outer space

International Nuclear Information System (INIS)

Anon.

1984-01-01

During the first week of May, the Fermilab theoretical astrophysics group hosted an international conference on science at the interface of particle physics and cosmology/astrophysics. The conference (Inner Space-Outer Space) was attended by a very diverse group of more than 200 physical scientists, including astronomers, astrophysicists, cosmologists, low-temperature physicists, and elementary particle theorists and experimentalists. The common interest which brought this diverse group to gether is the connection between physics on the smallest scale probed by man - the realm of elementary particle physics - and physics on the largest scale imaginable (the entire Universe) - the realm of cosmology

WORKSHOP: Inner space - outer space

Energy Technology Data Exchange (ETDEWEB)

Anon.

1984-09-15

During the first week of May, the Fermilab theoretical astrophysics group hosted an international conference on science at the interface of particle physics and cosmology/astrophysics. The conference (Inner Space-Outer Space) was attended by a very diverse group of more than 200 physical scientists, including astronomers, astrophysicists, cosmologists, low-temperature physicists, and elementary particle theorists and experimentalists. The common interest which brought this diverse group to gether is the connection between physics on the smallest scale probed by man - the realm of elementary particle physics - and physics on the largest scale imaginable (the entire Universe) - the realm of cosmology.

A generalized Wigner function on the space of irreducible representations of the Weyl-Heisenberg group and its transformation properties

International Nuclear Information System (INIS)

Ibort, A; Man'ko, V I; Marmo, G; Simoni, A; Ventriglia, F

2009-01-01

A natural extension of the Wigner function to the space of irreducible unitary representations of the Weyl-Heisenberg group is discussed. The action of the automorphisms group of the Weyl-Heisenberg group onto Wigner functions and their generalizations and onto symplectic tomograms is elucidated. Some examples of physical systems are considered to illustrate some aspects of the characterization of the Wigner functions as solutions of differential equations

Empowering a group of seniors in a rural community

Directory of Open Access Journals (Sweden)

Ana Rita Marinho Machado

2015-02-01

Full Text Available OBJECTIVE To describe the stages of the empowerment process of a group of seniors in a rural community. METHOD Convergent care research whose foundation is to use the scope of practice. Conducted with the proposal to change the practice of 21 seniors and nine health professionals, with the aim of health promotion empowerment. Data were collected during 22 meetings, and group interviews at the end of the intervention. RESULTS Showed that despite the initial impact of the change, the group was able to welcome the new change, taking advantage of the space to express anxieties, share joys, and build new knowledge, which led to the incorporation of changes that reflected in the development of healthy habits and improvements in interpersonal relationships. CONCLUSION The convergent care research consisted of strategy that changed the group's lives, empowering them with health promoting actions.

The topotactic dehydration of monoclinic {[Co(pht)(bpy)(H2O)2]·2H2O}n into orthorhombic [Co(pht)(bpy)(H2O)2]n (pht is phthalate and bpy is 4,4'-bipyridine).

Science.gov (United States)

Harvey, Miguel Angel; Suarez, Sebastián; Cukiernik, Fabio D; Baggio, Ricardo

2014-10-01

Controlled heating of single crystals of the previously reported [Köferstein & Robl (2007). Z. Anorg. Allg. Chem. 633, 1127-1130] dihydrate {[Co(pht)(bpy)(H2O)2]·2H2O}n, (II) [where pht is phthalate (C8H4O4) and bpy is 4,4'-bipyridine (C10H8N2)], produced a topotactic transformation into an unreported diaqua anhydrate, namely poly[diaqua(μ2-benzene-1,2-dicarboxylato-κ(2)O(1):O(2))(μ2-4,4'-bipyridine-κ(2)N:N')cobalt(II)], [Co(C8H4O4)(C10H8N2)(H2O)2]n, (IIa). The structural change consists of the loss of the two solvent water molecules linking the original two-dimensional covalent substructures which are the `main frame' of the monoclinic P2/n hydrate (strictly preserved during the transformation), with further reaccommodation of the latter. The anhydrate organizes itself in the orthorhombic system (space group Pmn2(1)) in a disordered fashion, where the space-group-symmetry restrictions are achieved only in a statistical sense, with mirror-related two-dimensional planar substructures, mirrored in a plane perpendicular to [100]. Thus, the asymmetric unit in the refined model is composed of two superimposed mirror-related `ghosts' of half-occupancy each. Similarities and differences with the parent dihydrate and some other related structures in the literature are discussed.

A Corresponding Lie Algebra of a Reductive homogeneous Group and Its Applications

International Nuclear Information System (INIS)

Zhang Yu-Feng; Rui Wen-Juan; Wu Li-Xin

2015-01-01

With the help of a Lie algebra of a reductive homogeneous space G/K, where G is a Lie group and K is a resulting isotropy group, we introduce a Lax pair for which an expanding (2+1)-dimensional integrable hierarchy is obtained by applying the binormial-residue representation (BRR) method, whose Hamiltonian structure is derived from the trace identity for deducing (2+1)-dimensional integrable hierarchies, which was proposed by Tu, et al. We further consider some reductions of the expanding integrable hierarchy obtained in the paper. The first reduction is just right the (2+1)-dimensional AKNS hierarchy, the second-type reduction reveals an integrable coupling of the (2+1)-dimensional AKNS equation (also called the Davey-Stewartson hierarchy), a kind of (2+1)-dimensional Schrödinger equation, which was once reobtained by Tu, Feng and Zhang. It is interesting that a new (2+1)-dimensional integrable nonlinear coupled equation is generated from the reduction of the part of the (2+1)-dimensional integrable coupling, which is further reduced to the standard (2+1)-dimensional diffusion equation along with a parameter. In addition, the well-known (1+1)-dimensional AKNS hierarchy, the (1+1)-dimensional nonlinear Schrödinger equation are all special cases of the (2+1)-dimensional expanding integrable hierarchy. Finally, we discuss a few discrete difference equations of the diffusion equation whose stabilities are analyzed by making use of the von Neumann condition and the Fourier method. Some numerical solutions of a special stationary initial value problem of the (2+1)-dimensional diffusion equation are obtained and the resulting convergence and estimation formula are investigated. (paper)

Single Crystal Piezoelectric Stack Actuator DM with Integrated Low-Power HVA-Based Driver ASIC, Phase I

Data.gov (United States)

National Aeronautics and Space Administration — This SBIR Phase I project aims to develop an innovative batch fabrication technique to create single crystal PMN-PT stack actuator deformable mirrors (DM) at low...

14 CFR 21.37 - Flight test pilot.

Science.gov (United States)

2010-01-01

... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Flight test pilot. 21.37 Section 21.37... PROCEDURES FOR PRODUCTS AND PARTS Type Certificates § 21.37 Flight test pilot. Each applicant for a normal... holding an appropriate pilot certificate to make the flight tests required by this part. [Doc. No. 5085...

Real-space renormalization group; application to site percolation in square lattice

International Nuclear Information System (INIS)

Tsallis, C.; Schwachheim, G.

1978-05-01

The real-space renormalization group proposed by Reynolds, Klein and Stanley 1977 to treat the site percolation is analysed and extended . The best among 3 possible definitions of 'percolating' configurations and among 5 possible methods to weight these configurations, are established for percolation in square lattices. The use of n xn square clusters leads, for n = 2 (RKS), n = 3 and n = 4, to √ sub (p) approximately equal to 1.635, √ sub(p) approximately equal to 1.533 and √ sub(p) approximately equal to 1.498, and also to P sub(c) approximately equal to 0.382, P sub(c) approximately equal to 0.388 and P sub(c) approximately equal to 0.398, exhibiting in this way the correct (but slow) tendency towards the best up to date values [pt

Location preferences of groups in public leisure spaces: the case of Likya Cafe in Ankara

OpenAIRE

Altay, Can

1999-01-01

Ankara : Department of Interior Architecture and Environmental Design and Institute of Economics and Social Sciences, Bilkent Univ., 1999. Thesis (Master's) -- Bilkent University, 1999. Includes bibliographical references. In this study, public leisure spaces are examined considering the social and spatial behavior of occupant groups. After an introduction to the concepts of leisure, its types, its relations with public life and cultural concepts, the study discusses leisure ...

Applied Nanotechnology for Human Space Exploration

Science.gov (United States)

Yowell, Leonard L.

2007-01-01

A viewgraph presentation describing nanotechnology for human space exploration is shown. The topics include: 1) NASA's Strategic Vision; 2) Exploration Architecture; 3) Future Exploration Mission Requirements Cannot be met with Conventional Materials; 4) Nanomaterials: Single Wall Carbon Nanotubes; 5) Applied Nanotechnology at JSC: Fundamentals to Applications; 6) Technology Readiness Levels (TRL); 7) Growth, Modeling, Diagnostics and Production; 8) Characterization: Purity, Dispersion and Consistency; 9) Processing; 10) Nanoelectronics: Enabling Technologies; 11) Applications for Human Space Exploration; 12) Exploration Life Support: Atmosphere Revitalization System; 13) Advanced and Exploration Life Support: Regenerable CO2 Removal; 14) Exploration Life Support: Water Recovery; 15) Advanced Life Support: Water Disinfection/Recovery; 16) Power and Energy: Supercapacitors and Fuel Cells; 17) Nanomaterials for EMI Shielding; 18) Active Radiation Dosimeter; 19) Advanced Thermal Protection System (TPS) Repair; 20) Thermal Radiation and Impact Protection (TRIPS); 21) Nanotechnology: Astronaut Health Management; 22) JSC Nanomaterials Group Collaborations.

Groups on transformations in Finslerian spaces

International Nuclear Information System (INIS)

Misra, R.B.

1993-01-01

The article first appeared in the Internal Reports of the ICTP in 1981. Since then the topic has attracted a large number of authors and several contributions have been made thereafter. Thus, a previous work of the author is revised and up-dated here including the post-1981 contributions in the field. Infinitesimal transformations defining motions, affine motions, projective motions, conformal transformations and curvature collineations in various types of Finslerian spaces are discussed here. The notation and symbolism used in the paper is mainly based on the author's works. (author). 72 refs

Realizing spaces as path-component spaces

OpenAIRE

Banakh, Taras; Brazas, Jeremy

2018-01-01

The path component space of a topological space $X$ is the quotient space $\\pi_0(X)$ whose points are the path components of $X$. We show that every Tychonoff space $X$ is the path-component space of a Tychonoff space $Y$ of weight $w(Y)=w(X)$ such that the natural quotient map $Y\\to \\pi_0(Y)=X$ is a perfect map. Hence, many topological properties of $X$ transfer to $Y$. We apply this result to construct a compact space $X\\subset \\mathbb{R}^3$ for which the fundamental group $\\pi_1(X,x_0)$ is...

Compactness of the automorphism group of a topological parallelism on real projective 3-space: The disconnected case

OpenAIRE

Rainer, Löwen

2017-01-01

We prove that the automorphism group of a topological parallelism on real projective 3-space is compact. In a preceding article it was proved that at least the connected component of the identity is compact. The present proof does not depend on that earlier result.

Couplings in D(2,1;α) superconformal mechanics from the SU(2) perspective

Energy Technology Data Exchange (ETDEWEB)

Galajinsky, Anton [Laboratory of Mathematical Physics, Tomsk Polytechnic University,Lenin Ave. 30, 634050 Tomsk (Russian Federation)

2017-03-09

Dynamical realizations of the most general N=4 superconformal group in one dimension D(2,1;α) are reconsidered from the perspective of the R-symmetry subgroup SU(2). It is shown that any realization of the R-symmetry subalgebra in some phase space can be extended to a representation of the Lie superalgebra corresponding to D(2,1;α). Novel couplings of arbitrary number of supermultiplets of the type (1,4,3) and (0,4,4) to a single supermultiplet of either the type (3,4,1), or (4,4,0) are constructed. D(2,1;α) superconformal mechanics describing superparticles propagating near the horizon of the extreme Reissner-Nordström-AdS-dS black hole in four and five dimensions is considered. The parameter α is linked to the cosmological constant.

Interagency mechanical operations group numerical systems group

Energy Technology Data Exchange (ETDEWEB)

NONE

1997-09-01

This report consists of the minutes of the May 20-21, 1971 meeting of the Interagency Mechanical Operations Group (IMOG) Numerical Systems Group. This group looks at issues related to numerical control in the machining industry. Items discussed related to the use of CAD and CAM, EIA standards, data links, and numerical control.

The normal holonomy group

International Nuclear Information System (INIS)

Olmos, C.

1990-05-01

The restricted holonomy group of a Riemannian manifold is a compact Lie group and its representation on the tangent space is a product of irreducible representations and a trivial one. Each one of the non-trivial factors is either an orthogonal representation of a connected compact Lie group which acts transitively on the unit sphere or it is the isotropy representation of a single Riemannian symmetric space of rank ≥ 2. We prove that, all these properties are also true for the representation on the normal space of the restricted normal holonomy group of any submanifold of a space of constant curvature. 4 refs

Processing, properties, and application of textured 0.72lead(magnesium niobate)-0.28lead titanate ceramics

Science.gov (United States)

Brosnan, Kristen H.

In this study, XRD and electron backscatter diffraction (EBSD) techniques were used to characterize the fiber texture in oriented PMN-28PT and the intensity data were fit with a texture model (the March-Dollase equation) that describes the texture in terms of texture fraction (f), and the width of the orientation distribution (r). EBSD analysis confirmed the orientation of the microstructure, with no distinguishable randomly oriented, fine grain matrix. Although XRD rocking curve and EBSD data analysis gave similar f and r values, XRD rocking curve analysis was the most efficient and gave a complete description of texture fraction and texture orientation (f = 0.81 and r = 0.21, respectively). XRD rocking curve analysis was the preferred approach for characterization of the texture volume and the orientation distribution of texture in fiber-oriented PMN-PT. The dielectric, piezoelectric and electromechanical properties for random ceramic, 69 vol% textured, 81 vol% textured, and single crystal PMN-28PT were fully characterized and compared. The room temperature dielectric constant at 1 kHz for highly textured PMN-28PT was epsilonr ≥ 3600 with low dielectric loss (tan delta = 0.004). The temperature dependence of the dielectric constant for 81 vol% textured ceramic followed a similar trend as the single crystal PMN-28PT up to the rhombohedral to tetragonal transition temperature (TRT) at 104°C. 81 vol% textured PMN-28PT consistently displayed 60 to 65% of the single crystal PMN-28PT piezoelectric coefficient (d33) and 1.5 to 3.0 times greater than the random ceramic d33 (measured by Berlincourt meter, unipolar strain-field curves, IEEE standard resonance method, and laser vibrometry). The 81 vol% textured PMN-28PT displayed similarly low piezoelectric hysteresis as single crystal PMN-28PT measured by strain-field curves at 5 kV/cm. 81 vol% textured PMN-28PT and single crystal PMN-28PT displayed similar mechanical quality factors of QM = 74 and 76, respectively. The

Space Elevators: Building a Permanent Bridge for Space Exploration and Economic Development

Science.gov (United States)

Smitherman, David V., Jr.; Howell, Joe T. (Technical Monitor)

2000-01-01

A space elevator is a physical connection from the surface of the Earth to a geo-stationary orbit above the Earth approximately 35,786 km in altitude. Its center of mass is at the geo-stationary point such that it has a 24-hour orbit, and stays over the same point above the equator as the Earth rotates on its axis. The structure is utilized as a transportation and utility system for moving payloads, power, and gases between the surface of the Earth and space. It makes the physical connection from Earth to space in the same way a bridge connects two cities across a body of' water. The space elevator may be an important concept for the future development of space in the latter part of the 21th century. It has the potential to provide mass-transportation to space in the same way highways, railroads, power lines, and pipelines provide mass-transportation across the Earth's surface. The low energy requirements for moving payloads up and down the elevator make it one of only a few concepts that has the potential of lowering the cost to orbit to less than $10 per kilogram. This paper will summarize the findings from a 1999 NASA workshop on Space Elevators held at the NASA Marshall Space Flight Center (MSFC). The workshop was sponsored by the Advanced Projects Office in the Flight Projects Directorate at MSFC, and was organized in cooperation with the Advanced Space Transportation Program at MSFC and the Advanced Concepts Office in the Office of Space Flight at NASA Headquarters. New concepts will be examined for space elevator construction and a number of issues will be discussed that has helped to bring the space elevator concept out of the realm of science fiction and into the realm of possibility. In conclusion, it appears that the space elevator concept may well he possible in the latter part of the 21st century if proper planning and technology development is emphasized to resolve key issues in the development of this advanced space infrastructure concept.

Academic Training: Deep Space Telescopes

CERN Multimedia

Françoise Benz

2006-01-01

2005-2006 ACADEMIC TRAINING PROGRAMME LECTURE SERIES 20, 21, 22, 23, 24 February from 11:00 to 12:00 - Council Chamber on 20, 21, 23, 24 February, TH Auditorium, bldg 4 - 3-006, on 22 February Deep Space Telescopes G. BIGNAMI / CNRS, Toulouse, F & Univ. di Pavia, I The short series of seminars will address results and aims of current and future space astrophysics as the cultural framework for the development of deep space telescopes. It will then present such new tools, as they are currently available to, or imagined by, the scientific community, in the context of the science plans of ESA and of all major world space agencies. Ground-based astronomy, in the 400 years since Galileo's telescope, has given us a profound phenomenological comprehension of our Universe, but has traditionally been limited to the narrow band(s) to which our terrestrial atmosphere is transparent. Celestial objects, however, do not care about our limitations, and distribute most of the information about their physics thro...

Hilbert spaces contractively included in the Hardy space of the bidisk

NARCIS (Netherlands)

Alpay, D.; Bolotnikov, V.; Dijksma, A.; Sadosky, C.

We study the reproducing kernel Hilbert spaces h(D-2,S) with kernels of the form I-S(z(1),z(2)>)S(w(1),w(2))*/(1-z(1)w(1)*) (1-z(2)w(2)*) where S(z(1),z(2)) is a Schur function of two variables z(1),z(2)is an element of D. They are analogs of the spaces h(D,S) with reproducing kernel

Moduli space of Chern-Simons gravity

International Nuclear Information System (INIS)

Soda, Jiro; Yamanaka, Yuki

1990-09-01

Conformally invariant (2+1)-dimensional gravity, Chern-Shimons gravity, is studied. Its solution space, moduli space, is investigated using the linearization method. The dimension of moduli space is determined as 18g - 18 for g > 1,6 for g = 1 and 0 for g = 0. We discuss the geometrical meaning of our investigation. (author)

Unitary Representations of Gauge Groups

Science.gov (United States)

Huerfano, Ruth Stella

I generalize to the case of gauge groups over non-trivial principal bundles representations that I. M. Gelfand, M. I. Graev and A. M. Versik constructed for current groups. The gauge group of the principal G-bundle P over M, (G a Lie group with an euclidean structure, M a compact, connected and oriented manifold), as the smooth sections of the associated group bundle is presented and studied in chapter I. Chapter II describes the symmetric algebra associated to a Hilbert space, its Hilbert structure, a convenient exponential and a total set that later play a key role in the construction of the representation. Chapter III is concerned with the calculus needed to make the space of Lie algebra valued 1-forms a Gaussian L^2-space. This is accomplished by studying general projective systems of finitely measurable spaces and the corresponding systems of sigma -additive measures, all of these leading to the description of a promeasure, a concept modeled after Bourbaki and classical measure theory. In the case of a locally convex vector space E, the corresponding Fourier transform, family of characters and the existence of a promeasure for every quadratic form on E^' are established, so the Gaussian L^2-space associated to a real Hilbert space is constructed. Chapter III finishes by exhibiting the explicit Hilbert space isomorphism between the Gaussian L ^2-space associated to a real Hilbert space and the complexification of its symmetric algebra. In chapter IV taking as a Hilbert space H the L^2-space of the Lie algebra valued 1-forms on P, the gauge group acts on the motion group of H defining in an straight forward fashion the representation desired.

Fusion energy for space missions in the 21st Century

International Nuclear Information System (INIS)

Schulze, N.R.

1991-08-01

Future space missions were hypothesized and analyzed and the energy source for their accomplishment investigated. The mission included manned Mars, scientific outposts to and robotic sample return missions from the outer planets and asteroids, as well as fly-by and rendezvous mission with the Oort Cloud and the nearest star, Alpha Centauri. Space system parametric requirements and operational features were established. The energy means for accomplishing the High Energy Space Mission were investigated. Potential energy options which could provide the propulsion and electric power system and operational requirements were reviewed and evaluated. Fusion energy was considered to be the preferred option and was analyzed in depth. Candidate fusion fuels were evaluated based upon the energy output and neutron flux. Reactors exhibiting a highly efficient use of magnetic fields for space use while at the same time offering efficient coupling to an exhaust propellant or to a direct energy convertor for efficient electrical production were examined. Near term approaches were identified

Group dynamics in a long-term blind endeavor on Earth: An analog for space missions (Lewis & Clark Expedition group dynamic analysis)

Science.gov (United States)

Allner, M.; Rygalov, V.

2008-12-01

suggested distinguishable mission phase model, the Lewis and Clark Expedition will be analyzed for similarities to these space findings. Factors of consideration in support of this analysis involve an understanding of the leadership qualities of Lewis and Clark (and relations established and maintained with one another), the selection and diversity of their crew, and the group dynamics that were developed and maintained so carefully during the expedition. With this knowledge and understanding one can gain enormous insights useful in the planning and preparation for future long-duration space exploratory missions with high level of autonomy, mobility, minimal primary life support supply and high dependence on material re-circulation and In-Situ Resource Utilization approach.

Mode group specific amplification length in an asymmetric LPG assisted few-mode EDFA

Science.gov (United States)

Rastogi, Vipul; Gaur, Ankita; Aschieri, Pierre; Dussardier, Bernard

2017-01-01

This article presents a scheme for few-mode EDFA, which allows to choose independent amplification lengths for different mode groups. The EDF is a dual concentric core fiber, where the central core is connected to the line FMF and the ring core is doped with erbium to provide amplification. The modes of FMF are launched into the central core of the EDF, are converted into ring modes using LPG for amplification and then converted back into central core modes using another LPG. The distance between the LPGs determines the amplification length. The amplification length, can thus, be chosen for a given mode group. We demonstrate the working of this concept by choosing LP11 and LP21 mode groups of the FMF and show that a suitable choice of amplification lengths for the two mode groups can tailor the differential modal gain (DMG) to any desired value. We demonstrate achieving zero DMG among all the mode of LP11 and LP21 mode groups using this concept while having gain in excess of 20 dB. The study should be useful for optical fiber communication system employing space-division multiplexing (SDM).

The fundamental groupoid of the quotient of a Hausdorff space by a discontinuous action of a discrete group is the orbit groupoid of the induced action

OpenAIRE

Brown, Ronald; Higgins, Philip J.

2002-01-01

The main result is that the fundamental groupoid of the orbit space of a discontinuous action of a discrete group on a Hausdorff space which admits a universal cover is the orbit groupoid of the fundamental groupoid of the space. We also describe work of Higgins and of Taylor which makes this result usable for calculations. As an example, we compute the fundamental group of the symmetric square of a space. The main result, which is related to work of Armstrong, is due to Brown and Higgins in ...

Generalized spacetimes defined by cubic forms and the minimal unitary realizations of their quasiconformal groups

International Nuclear Information System (INIS)

Guenaydin, Murat; Pavlyk, Oleksandr

2005-01-01

We study the symmetries of generalized spacetimes and corresponding phase spaces defined by Jordan algebras of degree three. The generic Jordan family of formally real Jordan algebras of degree three describe extensions of the minkowskian spacetimes by an extra 'dilatonic' coordinate, whose rotation, Lorentz and conformal groups are SO(d-1), SO(d-1,1) x SO(1,1) and SO(d,2) x SO(2,1), respectively. The generalized spacetimes described by simple Jordan algebras of degree three correspond to extensions of minkowskian spacetimes in the critical dimensions (d = 3,4,6,10) by a dilatonic and extra commuting spinorial coordinates, respectively. Their rotation, Lorentz and conformal groups are those that occur in the first three rows of the Magic Square. The Freudenthal triple systems defined over these Jordan algebras describe conformally covariant phase spaces. Following hep-th/0008063, we give a unified geometric realization of the quasiconformal groups that act on their conformal phase spaces extended by an extra 'cocycle' coordinate. For the generic Jordan family the quasiconformal groups are SO(d+2,4), whose minimal unitary realizations are given. The minimal unitary representations of the quasiconformal groups F 4(4) , E 6(2) , E 7(-5) and E 8(-24) of the simple Jordan family were given in our earlier work

Quantum groups, roots of unity and particles on quantized Anti-de Sitter space

International Nuclear Information System (INIS)

Steinacker, H.

1997-01-01

Quantum groups in general and the quantum Anti-de Sitter group U q (so(2,3)) in particular are studied from the point of view of quantum field theory. The author shows that if q is a suitable root of unity, there exist finite-dimensional, unitary representations corresponding to essentially all the classical one-particle representations with (half) integer spin, with the same structure at low energies as in the classical case. In the massless case for spin ≥ 1, open-quotes naiveclose quotes representations are unitarizable only after factoring out a subspace of open-quotes pure gaugesclose quotes, as classically. Unitary many-particle representations are defined, with the correct classical limit. Furthermore, the author identifies a remarkable element Q in the center of U q (g), which plays the role of a BRST operator in the case of U q (so(2,3)) at roots of unity, for any spin ≥ 1. The associated ghosts are an intrinsic part of the indecomposable representations. The author shows how to define an involution on algebras of creation and anihilation operators at roots of unity, in an example corresponding to non-identical particles. It is shown how nonabelian gauge fields appear naturally in this framework, without having to define connections on fiber bundles. Integration on Quantum Euclidean space and sphere and on Anti-de Sitter space is studied as well. The author gives a conjecture how Q can be used in general to analyze the structure of indecomposable representations, and to define a new, completely reducible associative (tensor) product of representations at roots of unity, which generalizes the standard open-quotes truncatedclose quotes tensor product as well as many-particle representations

Quantum groups, roots of unity and particles on quantized Anti-de Sitter space

Energy Technology Data Exchange (ETDEWEB)

Steinacker, Harold [Univ. of California, Berkeley, CA (United States). Dept. of Physics

1997-05-23

Quantum groups in general and the quantum Anti-de Sitter group U_q(so(2,3)) in particular are studied from the point of view of quantum field theory. The author shows that if q is a suitable root of unity, there exist finite-dimensional, unitary representations corresponding to essentially all the classical one-particle representations with (half) integer spin, with the same structure at low energies as in the classical case. In the massless case for spin ≥ 1, "naive" representations are unitarizable only after factoring out a subspace of "pure gauges", as classically. Unitary many-particle representations are defined, with the correct classical limit. Furthermore, the author identifies a remarkable element Q in the center of U_q(g), which plays the role of a BRST operator in the case of U_q(so(2,3)) at roots of unity, for any spin ≥ 1. The associated ghosts are an intrinsic part of the indecomposable representations. The author shows how to define an involution on algebras of creation and anihilation operators at roots of unity, in an example corresponding to non-identical particles. It is shown how nonabelian gauge fields appear naturally in this framework, without having to define connections on fiber bundles. Integration on Quantum Euclidean space and sphere and on Anti-de Sitter space is studied as well. The author gives a conjecture how Q can be used in general to analyze the structure of indecomposable representations, and to define a new, completely reducible associative (tensor) product of representations at roots of unity, which generalizes the standard "truncated" tensor product as well as many-particle representations.

Center Director Bridges visits Disability Awareness and Action working Group Technology Fair

Science.gov (United States)

1999-01-01

Center Director Roy Bridges (standing, center) poses with members of the Disability Awareness and Action Working Group (DAAWG), which is holding the 1999 Technology Fair Oct. 20-21 at Kennedy Space Center. The Fair is highlighting vendors demonstrating mobility, hearing, vision and silent disability assistive technology. The purpose is to create an awareness of the types of technology currently available to assist people with various disabilities in the workplace. The theme is that of this year's National Disability Employment Awareness Month, 'Opening Doors to Ability.' Some of the vendors participating are Canine Companions for Independence, Goodwill Industries, Accessible Structures, Division of Blind Services, Space Coast Center for Independent Living, KSC Fitness Center and Delaware North Parks Services.

First meeting of the International Working Group on Advanced Technologies for Water Cooled Reactors, Vienna, 18-21 May 1987. (Pt. 1)

International Nuclear Information System (INIS)

1987-12-01

The first meeting of the IAEA International Working Group on Advanced Technologies for Water Cooled Reactors was held in Vienna, Austria from 18-21 May 1987. Part I of the Summary Report contains the minutes of the meeting

"Friends" and "Foes" in the Social Space of the Tatar Ethnic Group

Directory of Open Access Journals (Sweden)

Nataliia O. Khazieva

2017-10-01

Full Text Available The history of the World Culture is a demonstration of the "war" between the two opposites: on the one hand, we see a trend towards unification of all aspects of life on a global scale, and on the other, there is a clear confrontation between different groups of mankind. Of the many causes of the disunity of the people, the authors' focus at the opposition "friend – foe" as a metaphysical principle of formation of social space wasn't chosen by accident. The fact is that any culture, in principle, is dichotomous, and the opposition "friend – foe" is the fullest incarnation of this dichotomy. As a universal principle of the formation and functioning of the cultures, it originally manifests itself in every one of them. And, as the authors of the study suggest: this opposition could either "work" in general on the cross-cultural cooperation and unity or be one of the confrontation sources. The main result of the study is that history has prepared and put forward the Tartars for carrying out a special mission, to unite peoples and cultures. But the revolutionary social upheavals that take place in the modern world pose a threat (in the circumstances of forced migration of peoples, the growth of national consciousness of the former Soviet Union space, and especially in the face of Islamic fundamentalism on fulfilling this function.

EFSA CEF Panel (EFSA Panel on Food Contact Materials, Enzymes, Flavourings and Processing Aids), 2015. Scientific Opinion on Flavouring Group Evaluation 21, Revision 5 (FGE.21Rev5): Thiazoles, thiophenes, thiazoline and thienyl derivatives from chemical groups 29 and 30

DEFF Research Database (Denmark)

Nørby, Karin Kristiane; Beltoft, Vibe Meister

The Panel on Food Contact Materials, Enzymes, Flavourings and Processing Aids of the European Food Safety Authority was requested to evaluate 41 flavouring substances in Flavouring Group Evaluation 21, Revision 5, using the Procedure in Commission Regulation (EC) No 1565/2000. This revision...... have also been considered. Adequate specifications, including complete purity criteria and identity for the materials of commerce, have been provided for all 41 candidate substances....

Group Work Publication-1991.

Science.gov (United States)

Zimpfer, David G.

1992-01-01

Lists 21 new publications in group work, of which 9 are reviewed. Those discussed include publications on group counseling and psychotherapy, structured groups, support groups, psychodrama, and social group work. (Author/NB)

21SSD: a new public 21-cm EoR database

Science.gov (United States)

Eames, Evan; Semelin, Benoît

2018-05-01

With current efforts inching closer to detecting the 21-cm signal from the Epoch of Reionization (EoR), proper preparation will require publicly available simulated models of the various forms the signal could take. In this work we present a database of such models, available at 21ssd.obspm.fr. The models are created with a fully-coupled radiative hydrodynamic simulation (LICORICE), and are created at high resolution (10243). We also begin to analyse and explore the possible 21-cm EoR signals (with Power Spectra and Pixel Distribution Functions), and study the effects of thermal noise on our ability to recover the signal out to high redshifts. Finally, we begin to explore the concepts of `distance' between different models, which represents a crucial step towards optimising parameter space sampling, training neural networks, and finally extracting parameter values from observations.

Kent in space: Cosmic dust to space debris

Science.gov (United States)

McDonnell, J. A. M.

1994-10-01

The dusty heritage of the University of Kent's Space Group commenced at Jodrell Bank, Cheshire, U.K., the home of the largest steerable radio telescope. While Professor Bernard Lovell's 250 ft. diameter telescope was used to command the U.S. deep space Pioneer spacecraft, Professor Tony McDonnell, as a research student in 1960, was developing a space dust detector for the US-UK Ariel program. It was successful. With a Ph.D. safely under the belt, it seemed an inevitable step to go for the next higher degree, a B.T.A.] Two years with NASA at Goddard Space Flight Center, Greenbelt, provided excellent qualifications for such a graduation ('Been to America'). A spirited return to the University of Kent at Canterbury followed, to one of the green field UK University sites springing from the Robbins Report on Higher Education. Swimming against the current of the brain drain, and taking a very considerable reduction in salary, it was with some disappointment that he found that the UK Premier Harold Wilson's 'white-hot technological revolution' never quite seemed to materialize in terms of research funding] Research expertise, centered initially on cosmic dust, enlarged to encompass planetology during the Apollo program, and rightly acquired international acclaim, notching up a history of space missions over 25 years. The group now comprises 38 people supported by four sources: the government's Research Councils, the University, the Space Agencies and Industry. This paper describes the thrust of the group's Research Plan in Space Science and Planetology; not so much based on existing international space missions, but more helping to shape the direction and selection of space missions ahead.

Extending trust to immigrants: Generalized trust, cross-group friendship and anti-immigrant sentiments in 21 European societies.

Directory of Open Access Journals (Sweden)

Meta van der Linden

Full Text Available The aim of this study is twofold. First, we expand on the literature by testing whether generalized trust is negatively related to anti-immigrant sentiments in Europe. Second, we examine to what extent the relation between generalized trust and anti-immigrant sentiments is dependent upon cross-group friendships. We apply multilevel linear regression modeling to representative survey data enriched with levels of ethnic diversity covering 21 European countries. Results show that both generalized trust and cross-group friendship are negatively related to anti-immigrant sentiments. However, there is a negligible positive relation between generalized trust and cross-group friendship (r = .10, and we can clearly observe that they operate independently from one another. Hence, trusting actors are not more likely to form more cross-group friendships, and cross-group friendship do not lead to the development of more generalized trust. Instead, the findings show that generalized trust leads immigrants too to be included in the radius of trusted others and, as a consequence, the benign effects of generalized trust apply to them as well. We conclude that the strength of generalized trust is a form of generalization, beyond the confines of individual variations in intergroup experiences.

The new ternary pnictides Er12Ni30P21 and Er13Ni25As19: Crystal structures and magnetic properties

International Nuclear Information System (INIS)

Oryshchyn, Stepan; Babizhetskyy, Volodymyr; Zhak, Olga; Zelinska, Mariya; Pivan, Jean-Yves; Duppel, Viola; Simon, Arndt; Kienle, Lorenz

2010-01-01

The new ternary pnictides Er 12 Ni 30 P 21 and Er 13 Ni 25 As 19 have been synthesized from the elements. They crystallize with hexagonal structures determined from single-crystal X-ray data for Er 12 Ni 30 P 21 (space group P6 3 /m, a=1.63900(3) nm, c=0.37573(1) nm, Z=1, R F =0.062 for 1574 F-values and 74 variable parameters), and for Er 13 Ni 25 As 19 (Tm 13 Ni 25 As 19 -type structure, space group P6-bar , a=1.6208(1) nm, c=0.38847(2) nm, Z=1, R F =0.026 for 1549 F-values and 116 variable parameters). These compounds belong to a large family of hexagonal structures with a metal-metalloid ratio of 2:1. HRTEM investigations were conducted to probe for local ordering of the disordered structure at the nanoscale. The magnetic properties of the phosphide Er 12 Ni 30 P 21 have been studied in the temperature of range 2 eff =9.59 μ B corresponds to the theoretical value of Er 3+ . - Graphical abstract: The new ternary pnictides Er 12 Ni 30 P 21 and Er 13 Ni 25 As 19 have been synthesized from the elements. They crystallize with hexagonal structures determined from single-crystal X-ray data. The compounds belong to a large family of structures with a metal-metalloid ratio of 2:1. HRTEM investigations were conducted to probe for local ordering of the disordered structure at the nanoscale. Display Omitted

Polar phase transitions in heteroepitaxial stabilized La0.5Y0.5AlO3 thin films

Science.gov (United States)

Liu, Shenghua; Zhang, Chunfeng; Zhu, Mengya; He, Qian; Chakhalian, Jak; Liu, Xiaoran; Borisevich, Albina; Wang, Xiaoyong; Xiao, Min

2017-10-01

We report on the fabrication of epitaxial La0.5Y0.5AlO3 ultrathin films on (001) LaAlO3 substrates. Structural characterizations by scanning transmission electron microscopy and x-ray diffraction confirm the high quality of the film with a - b + c - AlO6 octahedral tilt pattern. Unlike either of the nonpolar parent compound, LaAlO3 and YAlO3, second harmonic generation measurements on the thin films suggest a nonpolar-polar phase transition at T c near 500 K, and a polar-polar phase transition at T a near 160 K. By fitting the angular dependence of the second harmonic intensities, we further propose that the two polar structures can be assigned to the Pmc2 1 and Pmn2 1 space group, while the high temperature nonpolar structure belongs to the Pbnm space group.

Invariant subspaces in some function spaces on symmetric spaces. II

International Nuclear Information System (INIS)

Platonov, S S

1998-01-01

Let G be a semisimple connected Lie group with finite centre, K a maximal compact subgroup of G, and M=G/K a Riemannian symmetric space of non-compact type. We study the problem of describing the structure of closed linear subspaces in various function spaces on M that are invariant under the quasiregular representation of the group G. We consider the case when M is a symplectic symmetric space of rank 1

Managing the space sciences

Science.gov (United States)

1995-01-01

In April 1994 the National Research Council received a request from NASA that the NRC's Space Studies Board provide guidance on questions relating to the management of NASA's programs in the space sciences. The issues raised in the request closely reflect questions posed in the agency's fiscal year 1994 Senate appropriations report. These questions included the following: Should all the NASA space science programs be gathered into a 'National Institute for Space Science'? What other organizational changes might be made to improve the coordination and oversight of NASA space science programs? What processes should be used for establishing interdisciplinary science priorities based on scientific merit and other criteria, while ensuring opportunities for newer fields and disciplines to emerge? And what steps could be taken to improve utilization of advanced technologies in future space scienc missions? This report details the findings of the Committee on the Future of Space Science (FOSS) and its three task groups: the Task Group on Alternative Organizations, Task Group on Research Prioritization, and the Task Group on Technology.

The Asean Space Organization : legal aspects and feasibility

NARCIS (Netherlands)

Noichim, Chukeat

2008-01-01

In the 21st century, space activities increasingly affect global society, economy, technology, culture, and the environment. Many countries wish to develop space activities in order to obtain space benefits. However, a lot of them, especially developing countries, face huge obstacles such as lack of

Group Dynamics as a Critical Component of Successful Space Exploration: Conceptual Theory and Insights from the Biosphere 2 Closure Experiment

Science.gov (United States)

Nelson, Mark; Allen, John P.

As space exploration and eventually habitation achieves longer durations, successfully managing group dynamics of small, physically isolated groups will become vital. The paper summarizes important underlying research and conceptual theory and how these manifested in a well-documented example: the closure experiments of Biosphere 2. Key research breakthroughs in discerning the operation of small human groups comes from the pioneering work of W.R. Bion. He discovered two competing modalities of behavior. The first is the “task-oriented” or work group governed by shared acceptance of goals, reality-thinking in relation to time, resources and rational, and intelligent management of challenges presented. The opposing, usually unconscious, modality is what Bion called the “basic-assumption” group and alternates between three “group animal” groups: dependency/kill the leader; fight/flight and pairing. If not dealt with, these dynamics work to undermine and defeat the conscious task group’s goal achievement. The paper discusses crew training and selection, various approaches to structuring the work and hierarchy of the group, the importance of contact with a larger population through electronic communication and dealing with the “us-them” syndrome frequently observed between crew and Mission Control. The experience of the first two year closure of Biosphere 2 is drawn on in new ways to illustrate vicissitudes and management of group dynamics especially as both the inside team of biospherians and key members of Mission Control had training in working with group dynamics. Insights from that experience may help mission planning so that future groups in space cope successfully with inherent group dynamics challenges that arise.

Looking toward to the next-generation space weather forecast system. Comments former a former space weather forecaster

International Nuclear Information System (INIS)

Tomita, Fumihiko

1999-01-01

In the 21st century, man's space-based activities will increase significantly and many kinds of space utilization technologies will assume a vital role in the infrastructure, creating new businesses, securing the global environment, contributing much to human welfare in the world. Communications Research Laboratory (CRL) has been contributing to the safety of human activity in space and to the further understanding of the solar terrestrial environment through the study of space weather, including the upper atmosphere, magnetosphere, interplanetary space, and the sun. The next-generation Space Weather Integrated Monitoring System (SWIMS) for future space activities based on the present international space weather forecasting system is introduced in this paper. (author)

The group approach to AdS space propagators

International Nuclear Information System (INIS)

Leonhardt, Thorsten; Manvelyan, Ruben; Ruehl, Werner

2003-01-01

We show that AdS two-point functions can be obtained by connecting two points in the interior of AdS space with one point on its boundary by a dual pair of Dobrev's boundary-to-bulk intertwiners and integrating over the boundary point

14 CFR 21.609 - Approval for deviation.

Science.gov (United States)

2010-01-01

... deviation. (a) Each manufacturer who requests approval to deviate from any performance standard of a TSO shall show that the standards from which a deviation is requested are compensated for by factors or... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Approval for deviation. 21.609 Section 21...

14 CFR 21.130 - Statement of conformity.

Science.gov (United States)

2010-01-01

... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Statement of conformity. 21.130 Section 21... conformity. Each holder or licensee of a type certificate only, for a product manufactured in the United... Administrator a statement of conformity (FAA Form 317). This statement must be signed by an authorized person...

Usage of liquid scintillation counting for detecting the chemiluminescence of cells and its application in medicine

International Nuclear Information System (INIS)

Li Tianxing; Liang Qizhong; Zou Xiaowei; Yang Zhaohen; Huang Yong; Li Huaqiang

1995-01-01

The liquid scintillator counting-chemiluminescence (LSC-CL) of mono-photon radiance is a sensitive, handy and high-autoanalytic technique. Through measuring basic CL, dependent CL and maximum phagocytic CL of polymorphonuclear (PMN), we studied best factor levels of the method with orthogonal design [L 9 (3 4 )]. The results showed the peak forms changed markedly (inter-group P -4 M). PMN-CL in blood was measured during acute attack of the old patients with chronic bronchitis and the children with pneumonia bronchial. It was suggested that PMN phagocytosis decreased. So the dynamic analysis of maximum phagocytic CL would help us with the deep going clinical researches of the mechanisms of anti-inflammation and injuring by the oxygen free radicals

Between-group behaviour in health care: gaps, edges, boundaries, disconnections, weak ties, spaces and holes. A systematic review

Directory of Open Access Journals (Sweden)

Braithwaite Jeffrey

2010-12-01

Full Text Available Abstract Background Gaps are typically regarded as a problem to be solved. People are stimulated to close or plug them. Researchers are moved to fill deficits in the literature in order to realise a more complete knowledge base, health authorities want to bridge policy-practice disconnections, managers to secure resources to remedy shortfalls between poor and idealised care, and clinicians to provide services to patients across the divides of organisational silos. Despite practical and policy work in many health systems to bridge gaps, it is valuable to study research examining them for the insights provided. Structural holes, spaces between social clusters and weak or absent ties represent fissures in networks, located in less densely populated parts of otherwise closely connected social structures. Such gaps are useful as they illustrate how communication potentially breaks down or interactivity fails. This paper discusses empirical and theoretical work on this phenomenon with the aim of analysing a specific exemplar, the structures of silos within health care organisations. Methods The research literature on social spaces, holes, gaps, boundaries and edges was searched systematically, and separated into health [n = 13] and non-health [n = 55] samples. The health literature was reviewed and synthesised in order to understand the circumstances between stakeholders and stakeholder groups that both provide threats to networked interactions and opportunities to strengthen the fabric of organisational and institutional inter-relationships. Results The research examples illuminate various network structure characteristics and group interactions. They explicate a range of opportunities for improved social and professional relations that understanding structural holes, social spaces and absent ties affords. A principal finding is that these kinds of gaps illustrate the conditions under which connections are strained or have been severed, where the

Quantum isometry groups

Indian Academy of Sciences (India)

Jyotishman Bhowmick

2015-11-07

Nov 7, 2015 ... Classical. Quantum. Background. Compact Hausdorff space. Unital C∗ algebra. Gelfand-Naimark. Compact Group. Compact Quantum Group. Woronowicz. Group Action. Coaction. Woronowicz. Riemannian manifold. Spectral triple. Connes. Isometry group. Quantum Isometry Group. To be discussed.

Nickel titanium springs versus stainless steel springs: A randomized clinical trial of two methods of space closure.

Science.gov (United States)

Norman, Noraina Hafizan; Worthington, Helen; Chadwick, Stephen Mark

2016-09-01

To compare the clinical performance of nickel titanium (NiTi) versus stainless steel (SS) springs during orthodontic space closure. Two-centre parallel group randomized clinical trial. Orthodontic Department University of Manchester Dental Hospital and Orthodontic Department Countess of Chester Hospital, United Kingdom. Forty orthodontic patients requiring fixed appliance treatment were enrolled, each being randomly allocated into either NiTi (n = 19) or SS groups (n = 21). Study models were constructed at the start of the space closure phase (T0) and following the completion of space closure (T1). The rate of space closure achieved for each patient was calculated by taking an average measurement from the tip of the canine to the mesiobuccal groove on the first permanent molar of each quadrant. The study was terminated early due to time constraints. Only 30 patients completed, 15 in each study group. There was no statistically significant difference between the amounts of space closed (mean difference 0.17 mm (95%CI -0.99 to 1.34; P = 0.76)). The mean rate of space closure for NiTi coil springs was 0.58 mm/4 weeks (SD 0.24) and 0.85 mm/4 weeks (SD 0.36) for the stainless steel springs. There was a statistically significant difference between the two groups (P = 0.024), in favour of the stainless steel springs, when the mean values per patient were compared. Our study shows that stainless steel springs are clinically effective; these springs produce as much space closure as their more expensive rivals, the NiTi springs.

14 CFR 21.502 - Approval of materials, parts, and appliances.

Science.gov (United States)

2010-01-01

... appliances. 21.502 Section 21.502 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF..., Materials, Parts, and Appliances: Import § 21.502 Approval of materials, parts, and appliances. (a) A material, part, or appliance, manufactured in a foreign country with which the United States has an...

Fusion energy for space missions in the 21st century: Executive summary

International Nuclear Information System (INIS)

Schulze, N.R.

1991-08-01

Future space missions were hypothesized and analyzed, and the energy source of their accomplishment investigated. The missions included manned Mars, scientific outposts to and robotic sample return missions from the outer planets and asteroids, as well as fly-by and rendezvous missions with the Oort Cloud and the nearest star, Alpha Centauri. Space system parametric requirements and operational features were established. The energy means for accomplishing missions where delta v requirements range from 90 km/sec to 30,000 km/sec (High Energy Space Mission) were investigated. The need to develop a power space of this magnitude is a key issue to address if the U.S. civil space program is to continue to advance as mandated by the National Space Policy. Potential energy options which could provide the propulsion and electrical power system and operational requirements were reviewed and evaluated. Fusion energy was considered to be the preferred option and was analyzed in depth. Candidate fusion fuels were evaluated based upon the energy output and neutron flux. Additionally, fusion energy can offer significant safety, environmental, economic, and operational advantages. Reactors exhibiting a highly efficient use of magnetic fields for space use while at the same time offering efficient coupling to an exhaust propellant or to a direct energy convertor for efficient electrical production were examined. Near term approaches were identified. A strategy that will produce fusion powered vehicles as part of the space transportation infrastructure was developed. Space program resources must be directed toward this issue as a matter of the top policy priority

Fusion energy for space missions in the 21st century: Executive summary

Science.gov (United States)

Schulze, Norman R.

1991-08-01

Future space missions were hypothesized and analyzed, and the energy source of their accomplishment investigated. The missions included manned Mars, scientific outposts to and robotic sample return missions from the outer planets and asteroids, as well as fly-by and rendezvous missions with the Oort Cloud and the nearest star, Alpha Centauri. Space system parametric requirements and operational features were established. The energy means for accomplishing missions where delta v requirements range from 90 km/sec to 30,000 km/sec (High Energy Space Mission) were investigated. The need to develop a power space of this magnitude is a key issue to address if the U.S. civil space program is to continue to advance as mandated by the National Space Policy. Potential energy options which could provide the propulsion and electrical power system and operational requirements were reviewed and evaluated. Fusion energy was considered to be the preferred option and was analyzed in depth. Candidate fusion fuels were evaluated based upon the energy output and neutron flux. Additionally, fusion energy can offer significant safety, environmental, economic, and operational advantages. Reactors exhibiting a highly efficient use of magnetic fields for space use while at the same time offering efficient coupling to an exhaust propellant or to a direct energy convertor for efficient electrical production were examined. Near term approaches were identified. A strategy that will produce fusion powered vehicles as part of the space transportation infrastructure was developed. Space program resources must be directed toward this issue as a matter of the top policy priority.

A simulation study on the topotactic transformations from aluminophosphate AlPO(4)-21 to AlPO(4)-25.

Science.gov (United States)

Li, J; Yu, J; Wang, K; Zhu, G; Xu, R

2001-11-05

Aluminophosphate AlPO(4)-21 (AWO), formulated /(CH(3))(2)NH(2)/[Al(3)P(3)O(12)(OH)], has been synthesized solvothermally by using dimethylamine as the template. Single-crystal X-ray diffraction analysis shows that AlPO(4)-21 crystallizes in the monoclinic space group P2(1)/n with a = 8.687(2) A, b = 17.428(5) A, c = 9.159(2) A, beta = 109.60(2) degrees, V = 1306.3(5) A(3), and Z = 4. XRD analysis shows that AlPO(4)-21 transforms to AlPO(4)-25 (ATV) upon calcination at 500 degrees C. The molecular dynamics simulation approach was used to investigate the topotactic transformations from AlPO(4)-21. The simulation study suggests that AlPO(4)-21 is energetically favored to transform to AlPO(4)-25, as well as other hypothetical forms, by the changing of the UUDD chains to the UDUD chains.

The extensions of space-time. Physics in the 8-dimensional homogeneous space D = SU(2,2)/K

International Nuclear Information System (INIS)

Barut, A.O.

1993-07-01

The Minkowski space-time is only a boundary of a bigger homogeneous space of the conformal group. The conformal group is the symmetry group of our most fundamental massless wave equations. These extended groups and spaces have many remarkable properties and physical implications. (author). 36 refs

Contribution of on-site Coulomb repulsion energy to structural, electronic and magnetic properties of SrCoO3 for different space groups: first-principles study

Directory of Open Access Journals (Sweden)

Muhammady Shibghatullah

2018-03-01

Full Text Available We report structural, electronic, and magnetic properties of SrCoO3 in Pm3̅m and P4/mbm space groups, which are calculated by using generalized gradient approximation corrected with on-site Coulomb repulsion U and exchange energies J. The cubic lattice parameter a and local magnetic moments of Co (μCo are optimized by varying U at Co 3d site. Employing ultrasoft pseudopotential, the values of U = 8 eV and J = 0.75 eV are the best choice for Pm3̅m space group. We found the value of μCo = 2.56 μB, which is consistent with the previous results. It was also found that Co 3d, hybridized with O 2p, is the main contributor to ferromagnetic metallic properties. Besides, norm-conserving pseudopotential promotes a, which is in good agreement with experimental result. However, it is not suitable for P4/mbm space group. By using ultrasoft pseudopotential, the value of U = 3 eV (J = 0.75 is the most suitable for P4/mbm group. Ferromagnetic metallic properties, Jahn-Teller distortion, and reasonable lattice parameters have been obtained. This study shows that U has significant contribution to the calculated properties and also points out that P4/mbm space group with US-PP is suitable to describe experimental results.

Deformations of polyhedra and polygons by the unitary group

Energy Technology Data Exchange (ETDEWEB)

Livine, Etera R. [Laboratoire de Physique, ENS Lyon, CNRS-UMR 5672, 46 Allée d' Italie, Lyon 69007, France and Perimeter Institute, 31 Caroline St N, Waterloo, Ontario N2L 2Y5 (Canada)

2013-12-15

a similar fashion trading the unitary group for the orthogonal group. We conclude with a discussion of the possible (deformation) dynamics that one can define on the space of polygons or polyhedra. This work is a priori useful in the context of discrete geometry but it should hopefully also be relevant to (loop) quantum gravity in 2+1 and 3+1 dimensions when the quantum geometry is defined in terms of gluing of (quantized) polygons and polyhedra.

Symmetry and group theory in chemistry

CERN Document Server

Ladd, M

1998-01-01

A comprehensive discussion of group theory in the context of molecular and crystal symmetry, this book covers both point-group and space-group symmetries.Provides a comprehensive discussion of group theory in the context of molecular and crystal symmetryCovers both point-group and space-group symmetriesIncludes tutorial solutions

Elementary particles in curved spaces

International Nuclear Information System (INIS)

Lazanu, I.

2004-01-01

The theories in particle physics are developed currently, in Minkowski space-time starting from the Poincare group. A physical theory in flat space can be seen as the limit of a more general physical theory in a curved space. At the present time, a theory of particles in curved space does not exist, and thus the only possibility is to extend the existent theories in these spaces. A formidable obstacle to the extension of physical models is the absence of groups of motion in more general Riemann spaces. A space of constant curvature has a group of motion that, although differs from that of a flat space, has the same number of parameters and could permit some generalisations. In this contribution we try to investigate some physical implications of the presumable existence of elementary particles in curved space. In de Sitter space (dS) the invariant rest mass is a combination of the Poincare rest mass and the generalised angular momentum of a particle and it permits to establish a correlation with the vacuum energy and with the cosmological constant. The consequences are significant because in an experiment the local structure of space-time departs from the Minkowski space and becomes a dS or AdS space-time. Discrete symmetry characteristics of the dS/AdS group suggest some arguments for the possible existence of the 'mirror matter'. (author)

The NASA Space Life Sciences Training Program: Accomplishments Since 2013

Science.gov (United States)

Rask, Jon; Gibbs, Kristina; Ray, Hami; Bridges, Desireemoi; Bailey, Brad; Smith, Jeff; Sato, Kevin; Taylor, Elizabeth

2017-01-01

The NASA Space Life Sciences Training Program (SLSTP) provides undergraduate students entering their junior or senior years with professional experience in space life science disciplines. This challenging ten-week summer program is held at NASA Ames Research Center. The primary goal of the program is to train the next generation of scientists and engineers, enabling NASA to meet future research and development challenges in the space life sciences. Students work closely with NASA scientists and engineers on cutting-edge research and technology development. In addition to conducting hands-on research and presenting their findings, SLSTP students attend technical lectures given by experts on a wide range of topics, tour NASA research facilities, participate in leadership and team building exercises, and complete a group project. For this presentation, we will highlight program processes, accomplishments, goals, and feedback from alumni and mentors since 2013. To date, 49 students from 41 different academic institutions, 9 staffers, and 21 mentors have participated in the program. The SLSTP is funded by Space Biology, which is part of the Space Life and Physical Sciences Research and Application division of NASA's Human Exploration and Operations Mission Directorate. The SLSTP is managed by the Space Biology Project within the Science Directorate at Ames Research Center.

Geometric modular action and transformation groups

International Nuclear Information System (INIS)

Summers, S.J.

1996-01-01

We study a weak form of geometric modular action, which is naturally associated with transformation groups of partially ordered sets and which provides these groups with projective representations. Under suitable conditions it is shown that these groups are implemented by point transformations of topological spaces serving as models for space-times, leading to groups which may be interpreted as symmetry groups of the space-times. As concrete examples, it is shown that the Poincare group and the de Sitter group can be derived from this condition of geometric modular action. Further consequences and examples are discussed. (orig.)

Fisher's Zeros as the Boundary of Renormalization Group Flows in Complex Coupling Spaces

International Nuclear Information System (INIS)

Denbleyker, A.; Du Daping; Liu Yuzhi; Meurice, Y.; Zou Haiyuan

2010-01-01

We propose new methods to extend the renormalization group transformation to complex coupling spaces. We argue that Fisher's zeros are located at the boundary of the complex basin of attraction of infrared fixed points. We support this picture with numerical calculations at finite volume for two-dimensional O(N) models in the large-N limit and the hierarchical Ising model. We present numerical evidence that, as the volume increases, the Fisher's zeros of four-dimensional pure gauge SU(2) lattice gauge theory with a Wilson action stabilize at a distance larger than 0.15 from the real axis in the complex β=4/g 2 plane. We discuss the implications for proofs of confinement and searches for nontrivial infrared fixed points in models beyond the standard model.

14 CFR 21.43 - Location of manufacturing facilities.

Science.gov (United States)

2010-01-01

... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Location of manufacturing facilities. 21.43... CERTIFICATION PROCEDURES FOR PRODUCTS AND PARTS Type Certificates § 21.43 Location of manufacturing facilities... location of the manufacturer's facilities places no undue burden on the FAA in administering applicable...

Recombination in the evolution of enterovirus C species sub-group that contains types CVA-21, CVA-24, EV-C95, EV-C96 and EV-C99.

Directory of Open Access Journals (Sweden)

Teemu Smura

Full Text Available Genetic recombination is considered to be a very frequent phenomenon among enteroviruses (Family Picornaviridae, Genus Enterovirus. However, the recombination patterns may differ between enterovirus species and between types within species. Enterovirus C (EV-C species contains 21 types. In the capsid coding P1 region, the types of EV-C species cluster further into three sub-groups (designated here as A-C. In this study, the recombination pattern of EV-C species sub-group B that contains types CVA-21, CVA-24, EV-C95, EV-C96 and EV-C99 was determined using partial 5'UTR and VP1 sequences of enterovirus strains isolated during poliovirus surveillance and previously published complete genome sequences. Several inter-typic recombination events were detected. Furthermore, the analyses suggested that inter-typic recombination events have occurred mainly within the distinct sub-groups of EV-C species. Only sporadic recombination events between EV-C species sub-group B and other EV-C sub-groups were detected. In addition, strict recombination barriers were inferred for CVA-21 genotype C and CVA-24 variant strains. These results suggest that the frequency of inter-typic recombinations, even within species, may depend on the phylogenetic position of the given viruses.

Effects of incentives on psychosocial performances in simulated space-dwelling groups

Science.gov (United States)

Hienz, Robert D.; Brady, Joseph V.; Hursh, Steven R.; Gasior, Eric D.; Spence, Kevin R.; Emurian, Henry H.

Prior research with individually isolated 3-person crews in a distributed, interactive, planetary exploration simulation examined the effects of communication constraints and crew configuration changes on crew performance and psychosocial self-report measures. The present report extends these findings to a model of performance maintenance that operationalizes conditions under which disruptive affective responses by crew participants might be anticipated to emerge. Experiments evaluated the effects of changes in incentive conditions on crew performance and self-report measures in simulated space-dwelling groups. Crews participated in a simulated planetary exploration mission that required identification, collection, and analysis of geologic samples. Results showed that crew performance effectiveness was unaffected by either positive or negative incentive conditions, while self-report measures were differentially affected—negative incentive conditions produced pronounced increases in negative self-report ratings and decreases in positive self-report ratings, while positive incentive conditions produced increased positive self-report ratings only. Thus, incentive conditions associated with simulated spaceflight missions can significantly affect psychosocial adaptation without compromising task performance effectiveness in trained and experienced crews.

14 CFR 21.9 - Replacement and modification articles.

Science.gov (United States)

2010-01-01

... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Replacement and modification articles. 21.9... CERTIFICATION PROCEDURES FOR PRODUCTS AND PARTS General § 21.9 Replacement and modification articles. (a) If a person knows, or should know, that a replacement or modification article is reasonably likely to be...

14 CFR 21.305 - Approval of materials, parts, processes, and appliances.

Science.gov (United States)

2010-01-01

..., and appliances. 21.305 Section 21.305 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION..., Parts, Processes, and Appliances § 21.305 Approval of materials, parts, processes, and appliances. Whenever a material, part, process, or appliance is required to be approved under this chapter, it may be...

Space research in the Netherlands 1980

International Nuclear Information System (INIS)

1981-01-01

In 1960, the Royal Netherlands Academy of Arts and Sciences established a committee with the task of coordinating space research in the Netherlands and maintaining the necessary international contacts. This committe, usually called GROC, has instituted four working groups, in which most of the Netherlands space research is concentrated. These groups are: Working Group for Solar and Stellar Space Research, Working Group for Cosmic Rays, Working Group for Photometry and the Working Group for Satellite Geodesy. General information on space research in the Netherlands Anno 1980 is given. Detailed data about the working groups, their work during 1980 and their programmes are presented, together with a survey of their scientific publications. A financial summary is also included. (Auth.)

Child spacing and contraception among the poor in Zambia

Directory of Open Access Journals (Sweden)

Vijayan K Pillai

2010-03-01

Full Text Available Vijayan K Pillai1, Rashmi Gupta21School of Social Work, University of Texas at Arlington, Arlington, TX, USA; 2Department of Social Work, San Francisco State University, San Francisco, CA, USAAbstract: For decades, family planning programs have targeted women in developing countries. These programs bestow a great deal of autonomy on women with respect to fertility decision making. It is well known that a number of close relatives in multigenerational and extended family systems influence women’s fertility decisions with respect to child spacing and contraceptive use. One approach toward a systematic study of fertility decision making is to explicitly consider the husband’s influences on fertility decision making. This study examines the effects of a selected number of factors on the desired birth interval lengths. We interviewed husbands and wives separately from 165 randomly selected households from two poor neighborhoods in the city of Kitwe, Zambia. Three ordinal birth interval groups were obtained for both husbands and wives separately. The effect of selected factors on the likelihood of influencing the three groups was examined using ordinal logistic regression methods. Data from husbands and wives were analyzed separately. Qualitative methods such as semistructured interviews were used to gather extensive information on the various factors that husbands and wives perceive to influence their child spacing decisions. We found differences in accounts with respect to child spacing between husbands and wives, likely due to a lack of communication. A gender-sensitive approach is necessary to promote spacing methods among poor couples in Zambia.Keywords: child spacing, contraceptive use, correspondence analysis, couple decision making

Classical N-particle cosmology in 2+1 dimensions

NARCIS (Netherlands)

Hooft, G. 't

1993-01-01

In 2+1 dimensional cosmology particles are topological defects in a universe that is nearly everywhere flat. The author uses a time dependent triangulation procedure of space to formulate the laws of evolution and to construct the phase space of this system. A theorem is derived from which it

Crystal structure of the new ternary thorium indide Th{sub 4}Pd{sub 10}In{sub 21}

Energy Technology Data Exchange (ETDEWEB)

Hlukhyy, V.; Zaremba, V.; Stepien-Damm, J.; Troc, R

2003-03-24

The structure of Th{sub 4}Pd{sub 10}In{sub 21} was refined from single crystal X-ray diffraction data. The compound crystallizes in the monoclinic system, space group C2/m, mC70; with lattice parameters a=23.024(5) A, b=4.512(1) A, c=17.224(3) A, {beta}=124.57(3) deg. The crystal structure was refined using the SHELXL-97 program (R{sub 1}=0.0477, 2561 F{sup 2} values for 108 variables). This compound adopts the Ho{sub 4}Ni{sub 10}Ga{sub 21}-type structure. The crystal chemistry and relationships of this phase to other ones are briefly discussed.

Topological aspects of classical and quantum (2+1)-dimensional gravity

International Nuclear Information System (INIS)

Soda, Jiro.

1990-03-01

In order to understand (3+1)-dimensional gravity, (2+1)-dimensional gravity is studied as a toy model. Our emphasis is on its topological aspects, because (2+1)-dimensional gravity without matter fields has no local dynamical degrees of freedom. Starting from a review of the canonical ADM formalism and York's formalism for the initial value problem, we will solve the evolution equations of (2+1)-dimensional gravity with a cosmological constant in the case of g=0 and g=1, where g is the genus of Riemann surface. The dynamics of it is understood as the geodesic motion in the moduli space. This remarkable fact is the same with the case of (2+1)-dimensional pure gravity and seen more apparently from the action level. Indeed we will show the phase space reduction of (2+1)-dimensional gravity in the case of g=1. For g ≥ 2, unfortunately we are not able to explicitly perform the phase space reduction of (2+1)-dimensional gravity due to the complexity of the Hamiltonian constraint equation. Based on this result, we will attempt to incorporate matter fields into (2+1)-dimensional pure gravity. The linearization and mini-superspace methods are used for this purpose. By using the linearization method, we conclude that the transverse-traceless part of the energy-momentum tensor affects the geodesic motion. In the case of the Einstein-Maxwell theory, we observe that the Wilson lines interact with the geometry to bend the geodesic motion. We analyze the mini-superspace model of (2+1)-dimensional gravity with the matter fields in the case of g=0 and g=1. For g=0, a wormhole solution is found but for g=1 we can not find an analogous solution. Quantum gravity is also considered and we succeed to perform the phase space reduction of (2+1)-dimensional gravity in the case of g=1 at the quantum level. From this analysis we argue that the conformal rotation is not necessary in the sense that the Euclidean quantum gravity is inappropriate for the full gravity. (author)

14 CFR 49.21 - Return of original conveyance.

Science.gov (United States)

2010-01-01

... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Return of original conveyance. 49.21... RECORDING OF AIRCRAFT TITLES AND SECURITY DOCUMENTS General § 49.21 Return of original conveyance. If a person submitting a conveyance for recording wants the original returned to him, he must submit a true...

33-Foot-Diameter Space Station Leading to Space Base

Science.gov (United States)

1969-01-01

This picture illustrates a concept of a 33-Foot-Diameter Space Station Leading to a Space Base. In-house work of the Marshall Space Flight Center, as well as a Phase B contract with the McDornel Douglas Astronautics Company, resulted in a preliminary design for a space station in 1969 and l970. The Marshall-McDonnel Douglas approach envisioned the use of two common modules as the core configuration of a 12-man space station. Each common module was 33 feet in diameter and 40 feet in length and provided the building blocks, not only for the space station, but also for a 50-man space base. Coupled together, the two modules would form a four-deck facility: two decks for laboratories and two decks for operations and living quarters. Zero-gravity would be the normal mode of operation, although the station would have an artificial gravity capability. This general-purpose orbital facility was to provide wide-ranging research capabilities. The design of the facility was driven by the need to accommodate a broad spectrum of activities in support of astronomy, astrophysics, aerospace medicine, biology, materials processing, space physics, and space manufacturing. To serve the needs of Earth observations, the station was to be placed in a 242-nautical-mile orbit at a 55-degree inclination. An Intermediate-21 vehicle (comprised of Saturn S-IC and S-II stages) would have launched the station in 1977.

The Poincare group as the symmetry group of canonical general relativity

International Nuclear Information System (INIS)

Beig, R.; Murchadha, N. o

1986-01-01

This work reconsiders the formulation, due to Regge and Teitelboim, of the phase space approach to General Relativity in the asymptotically flat context, phrasing it in the language of symplectic geometry. The necessary boundary conditions at spatial infinity are spelled out in detail. Precise meaning is given to the statement that, as a result of these boundary conditions, the Poincare group acts as a symmetry group on the phase space of G.R. This situation is compared with the spi-picture of Ashtekar and Hansen, where a larger asymptotic symmetry group is obtained. (Author)

SpaceTech—Postgraduate space education

Science.gov (United States)

de Bruijn, Ferdi J.; Ashford, Edward W.; Larson, Wiley J.

2008-07-01

, Interpersonal Skills, Telecommunications, Earth Observation and Navigation. A group CCP, a major asset of this unique program, is a focused project, aimed at the formation of a credible virtual commercial space-related business. Participants exercise space systems engineering fundamentals as well as marketing and business engineering tools, with the goal of creating a financially viable business opportunity. They then present the result, in the form of an unsolicited proposal to potential investors, as well as a varied group of engineers, managers and executives from the space community. During the CCP, participants learn the ties between mission and system design and the potential return to investors. They develop an instinct for the technical concepts and which of the parameters to adjust to make their newly conceived business more effective and profitable.

EFSA CEF Panel (EFSA Panel on Food Contact Materials, Enzymes, Flavourings and Processing Aids), 2013. Scientific Opinion on Flavouring Group Evaluation 21, Revision 4 (FGE.21Rev4)

DEFF Research Database (Denmark)

Beltoft, Vibe Meister; Binderup, Mona-Lise; Frandsen, Henrik Lauritz

The Panel on Food Contact Materials, Enzymes, Flavourings and Processing Aids of the European Food Safety Authority was requested to evaluate 59 flavouring substances in the Flavouring Group Evaluation 21, Revision 4, using the Procedure in Commission Regulation (EC) No 1565/2000. This revision...... of these flavouring substances, the specifications for the materials of commerce have also been considered. Adequate specifications including complete purity criteria and identity for the materials of commerce have been provided for all 41 candidate substances...

Creating space for citizenship: The impact of group structure on validating the voices of people with dementia.

Science.gov (United States)

Wiersma, Elaine C; O'Connor, Deborah L; Loiselle, Lisa; Hickman, Kathy; Heibein, Bill; Hounam, Brenda; Mann, Jim

2016-05-01

Recently, there has been increasing attention given to finding ways to help people diagnosed with dementia 'live well' with their condition. Frequently however, the attention has been placed on the family care partner as the foundation for creating a context that supports the person with dementia to live well. A recent participatory action research (PAR) study highlighted the importance of beginning to challenge some of the assumptions around how best to include family, especially within a context of supporting citizenship. Three advisory groups consisting of 20 people with dementia, 13 care partners, and three service providers, were set up in three locations across Canada to help develop a self-management program for people with dementia. The hubs met monthly for up to two years. One of the topics that emerged as extremely important to consider in the structuring of the program revolved around whether or not these groups should be segregated to include only people with dementia. A thematic analysis of these ongoing discussions coalesced around four inter-related themes: creating safe spaces; maintaining voice and being heard; managing the balancing act; and the importance of solidarity Underpinning these discussions was the fifth theme, recognition that 'one size doesn't fit all'. Overall an important finding was that the presence of family care-partners could have unintended consequences in relation to creating the space for active citizenship to occur in small groups of people with dementia although it could also offer some opportunities. The involvement of care partners in groups with people with dementia is clearly one that is complex without an obvious answer and dependent on a variety of factors to inform a solution, which can and should be questioned and revisited. © The Author(s) 2016.

Factorizable sheaves and quantum groups

CERN Document Server

Bezrukavnikov, Roman; Schechtman, Vadim

1998-01-01

The book is devoted to the geometrical construction of the representations of Lusztig's small quantum groups at roots of unity. These representations are realized as some spaces of vanishing cycles of perverse sheaves over configuration spaces. As an application, the bundles of conformal blocks over the moduli spaces of curves are studied. The book is intended for specialists in group representations and algebraic geometry.

Stochastic quantum gravity-(2+1)-dimensional case

International Nuclear Information System (INIS)

Hosoya, Akio

1991-01-01

At first the amazing coincidences are pointed out in quantum field theory in curved space-time and quantum gravity, when they exhibit stochasticity. To explore the origin of them, the (2+1)-dimensional quantum gravity is considered as a toy model. It is shown that the torus universe in the (2+1)-dimensional quantum gravity is a quantum chaos in a rigorous sense. (author). 15 refs

ORF Alignment: NC_002754 [GENIUS II[Archive

Lifescience Database Archive (English)

Full Text Available , ... 5'-Deoxy-5'-Methylthioadenosine Phosphorylase Complex ... With Phosphate (Space Group P2...1) pdb|1JDS|E Chain E, ... 5'-Deoxy-5'-Methylthioadenosine Phosphorylase Complex ... With Phosphate (Space... ... With Phosphate (Space Group P21) pdb|1JDS|C Chain C, ... 5'-De...oxy-5'-Methylthioadenosine Phosphorylase Complex ... With Phosphate (Space Group P21) pdb|1JDS|B Chai...n B, ... 5'-Deoxy-5'-Methylthioadenosine Phosphorylase Complex ... With Phosphate (Space Group

Re-Imagining the 21st Century School Library: From Storage Space to Active Learning Space

Science.gov (United States)

Grigsby, Susan K. S.

2015-01-01

As libraries adjust to the needs of the 21st century, there needs to be a different way of thinking in regards to its design. School libraries have traditionally been designed as large rooms for the storage of materials for research and pleasure reading. As more and more districts focus their attention on digital acquisitions, the need for storage…

Automorphisms of free groups with boundaries

DEFF Research Database (Denmark)

A. Jensen, Craig; Wahl, Nathalie

2004-01-01

The automorphisms of free groups with boundaries form a family of groups A_{n,k} closely related to mapping class groups, with the standard automorphisms of free groups as A_{n,0} and (essentially) the symmetric automorphisms of free groups as A_{0,k}. We construct a contractible space L_{n,k} on......The automorphisms of free groups with boundaries form a family of groups A_{n,k} closely related to mapping class groups, with the standard automorphisms of free groups as A_{n,0} and (essentially) the symmetric automorphisms of free groups as A_{0,k}. We construct a contractible space L......_{n,k} on which A_{n,k} acts with finite stabilizers and finite quotient space and deduce a range for the virtual cohomological dimension of A_{n,k}. We also give a presentation of the groups and calculate their first homology group....

EFSA CEF Panel (EFSA Panel on Food Contact Materials, Enzymes, Flavourings and Processing Aids), 2013. Scientific Opinion on Flavouring Group Evaluation 21, Revision 4 (FGE.21Rev4)

OpenAIRE

Beltoft, Vibe Meister; Binderup, Mona-Lise; Frandsen, Henrik Lauritz; Lund, Pia; Nørby, Karin Kristiane

2013-01-01

The Panel on Food Contact Materials, Enzymes, Flavourings and Processing Aids of the European Food Safety Authority was requested to evaluate 59 flavouring substances in the Flavouring Group Evaluation 21, Revision 4, using the Procedure in Commission Regulation (EC) No 1565/2000. This revision is made due to the inclusion of the assessment of new toxicity data on one supporting substance 5,6-dihydro-2,4,6-tris(2-methylpropyl)-4H-1,3,5-dithiazine [FL-no: 15.113], which is considered to be str...

PRIMARY MULTIPLE MALIGNAT TUMORS MOST COMMON LOCALIZATIONS CANCER - CANCER STUDY CLINICS

Directory of Open Access Journals (Sweden)

G. V. Goncharenko

2015-01-01

Full Text Available The purpose. Analysis of statistical data of oncological departmental polyclinics, serving a permanent attached contingent of patients in cases of the most common cancer sites: basal cell skin cancer, breast cancer, prostate cancer. Materials and methods. Analisis of medical history patients of polyclinics. There were registered 1054 patients with malignant tumors. Of these 128 (12.14% and had the PMN, of that number, 8 patients had triple the localization of cancer. BCC: skin diagnosis was 132 patients, of which 52 (39.9% of had the PMN. With the diagnosis: breast cancer was registered 179 patients, including 30 patients had the PMN of the 8 patients had bilateral breast cancer. Diagnosed with FPW to outpatients included 139 patients, of whom 20 people (14.4%. On each localization of cancer presented with second and third cancer localizations. Conclusion. Patients with BCC skin were the in group of high risk for the development of PMN. The second location was in case of every third patient. Most commonly BCC combined with breast cancer, prostate cancer, cancer of the colon.

Quantum symmetries of classical spaces

OpenAIRE

Bhowmick, Jyotishman; Goswami, Debashish; Roy, Subrata Shyam

2009-01-01

We give a general scheme for constructing faithful actions of genuine (noncommutative as $C^*$ algebra) compact quantum groups on classical topological spaces. Using this, we show that: (i) a compact connected classical space can have a faithful action by a genuine compact quantum group, and (ii) there exists a spectral triple on a classical connected compact space for which the quantum group of orientation and volume preserving isometries (in the sense of \\cite{qorient}) is a genuine quantum...

A Unified Approach to UXO Discrimination Using the Method of Auxiliary Sources

Science.gov (United States)

2006-10-12

0 and is sin(mφ) for p = 1, bpmn the spheroidal expansion coefficients. Eq. (2.1) is a decomposition of a primary magnetic potential into a number of...spheroidal expansion coefficients bpmn can be derived as bpmn = − 2n+ 1 γπH0dP ′mn (ξ0) (n−m)! (n+m)! ∫ 1 −1 Pmn (η)hξ ∫ 2π 0 Hprξ (η, ξ0, φ)Tpm(φ)dφdη...the object’s response for each pmn excitation mode (Chen et al., 2004; Sun et al., 2005), i.e., Hsc(r) = M ∑ m=0 N ∑ n=m 1 ∑ p=0 bpmn Nq ∑ i=1 qpmni G

Activated human neutrophils release hepatocyte growth factor/scatter factor.

LENUS (Irish Health Repository)

McCourt, M

2012-02-03

BACKGROUND: Hepatocyte growth factor or scatter factor (HGF\\/SF) is a pleiotropic cytokine that has potent angiogenic properties. We have previously demonstrated that neutrophils (PMN) are directly angiogenic by releasing vascular endothelial growth factor (VEGF). We hypothesized that the acute inflammatory response can stimulate PMN to release HGF. AIMS: To examine the effects of inflammatory mediators on PMN HGF release and the effect of recombinant human HGF (rhHGF) on PMN adhesion receptor expression and PMN VEGF release. METHODS: In the first experiment, PMN were isolated from healthy volunteers and stimulated with tumour necrosis factor-alpha (TNF-alpha), lipopolysaccharide (LPS), interleukin-8 (IL-8), and formyl methionyl-leucyl-phenylalanine (fMLP). Culture supernatants were assayed for HGF using ELISA. In the second experiment, PMN were lysed to measure total HGF release and HGF expression in the PMN was detected by Western immunoblotting. Finally, PMN were stimulated with rhHGF. PMN CD 11a, CD 11b, and CD 18 receptor expression and VEGF release was measured using flow cytometry and ELISA respectively. RESULTS: TNF-alpha, LPS and fMLP stimulation resulted in significantly increased release of PMN HGF (755+\\/-216, 484+\\/-221 and 565+\\/-278 pg\\/ml, respectively) compared to controls (118+\\/-42 pg\\/ml). IL-8 had no effect. Total HGF release following cell lysis and Western blot suggests that HGF is released from intracellular stores. Recombinant human HGF did not alter PMN adhesion receptor expression and had no effect on PMN VEGF release. CONCLUSIONS: This study demonstrates that pro-inflammatory mediators can stimulate HGF release from a PMN intracellular store and that activated PMN in addition to secreting VEGF have further angiogenic potential by releasing HGF.

Tethers in Space

Science.gov (United States)

Johnson, Les; Bilén, Sven G.; Gilchrist, Brian E.; Krause, Linda Habash

2017-09-01

This Special Section of Acta Astronautica contains several peer-reviewed papers selected from among those presented at the Fifth International Conference on Tethers in Space (TiS2016). After a hiatus of 21 years since the last Conference on Tethers in Space, TiS2016 brought together experts, practitioners, and other interested in space tethers and related fields. TiS2016 was held May 24-26, 2016 at The University of Michigan in Ann Arbor, Michigan, U.S.A. Leveraging the hard work of a great many volunteers, the conference co-chairs Prof. Brian Gilchrist and Prof. Sven Bilén welcomed an international contingent with authors from the U.S., Canada, Japan, Spain, China, Finland, Estonia, and Italy. The community provided updates on what has transpired since their last gathering by providing lessons learned; describing new technologies and subsystems; and proposing new tether missions and applications. Papers overviewed de-orbit systems, power generation, orbital maneuvering, momentum capture, debris removal, space tugs, space elevators, collision avoidance, and tether dynamics, among others.

Effective dielectric function of porous Pb(Mg.sub.1/3./sub.Nb.sub.2/3./sub.O.sub.3./sub. ceramics

Czech Academy of Sciences Publication Activity Database

Nuzhnyy, Dmitry; Petzelt, Jan; Rychetský, Ivan; Trefalt, G.

2014-01-01

Roč. 89, č. 21 (2014), "214307-1"-"214307-5" ISSN 1098-0121 R&D Projects: GA ČR GAP204/12/0232 Institutional support: RVO:68378271 Keywords : PMN ceramics * infrared and THz spectroscopy * effective medium models * finite element method Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 3.736, year: 2014

Dopamine attenuates the chemoattractant effect of interleukin-8: a novel role in the systemic inflammatory response syndrome.

LENUS (Irish Health Repository)

Sookhai, S

2012-02-03

Activated neutrophil (PMN) adherence to vascular endothelium comprises a key step for both transendothelial migration and initiation of potentially deleterious release of PMN products. The biogenic amine, dopamine (DA), has been used for several decades in patients to maintain hemodynamic stability. The effect of dopamine on PMN transendothelial migration and adhesion receptor expression and on the endothelial molecules, E-selectin and ICAM-1, was evaluated. PMN were isolated from healthy controls, stimulated with lipopolysaccharide (LPS), and tumor necrosis factor-alpha (TNF-alpha) and treated with dopamine. CD 11b and CD 18 PMN adhesion receptor expression were assessed flow cytometrically. In a separate experiment, the chemoattractant peptide, IL-8, was placed in the lower chamber of transwells, and PMN migration was assessed. Human umbilical vein endothelial cells (HUVEC) were stimulated with LPS\\/TNF-alpha and incubated with dopamine. ICAM-1 and E-selectin endothelial molecule expression were assessed flow cytometrically. There was a significant increase in transendothelial migration in stimulated PMN compared with normal PMN (40 vs. 14%, P < 0.001). In addition, PMN CD11b\\/CD18 was significantly upregulated in stimulated PMN compared with normal PMN (252.4\\/352.4 vs. 76.7\\/139.4, P < 0.001) as were endothelial E-selectin\\/ICAM-1 expression compared with normal EC (8.1\\/9 vs. 3.9\\/3.8, P < 0.05). After treatment with dopamine, PMN transmigration was significantly decreased compared with stimulated PMN (8% vs. 40%, P < 0.001). Furthermore, dopamine also attenuated PMN CD11b\\/CD18 and the endothelial molecules E-selectin and ICAM-1 compared with stimulated PMN\\/EC that were not treated dopamine (174\\/240 vs. 252\\/352, P < 0.05 and 4\\/4.4 vs. 8.1\\/9, P < 0.05. respectively). The chemoattractant effect of IL-8 was also attenuated. These results identify for the first time that dopamine attenuates the initial interaction between PMN and the endothelium

Topology of actions and homogeneous spaces

International Nuclear Information System (INIS)

Kozlov, Konstantin L

2013-01-01

Topologization of a group of homeomorphisms and its action provide additional possibilities for studying the topological space, the group of homeomorphisms, and their interconnections. The subject of the paper is the use of the property of d-openness of an action (introduced by Ancel under the name of weak micro-transitivity) in the study of spaces with various forms of homogeneity. It is proved that a d-open action of a Čech-complete group is open. A characterization of Polish SLH spaces using d-openness is given, and it is established that any separable metrizable SLH space has an SLH completion that is a Polish space. Furthermore, the completion is realized in coordination with the completion of the acting group with respect to the two-sided uniformity. A sufficient condition is given for extension of a d-open action to the completion of the space with respect to the maximal equiuniformity with preservation of d-openness. A result of van Mill is generalized, namely, it is proved that any homogeneous CDH metrizable compactum is the only G-compactification of the space of rational numbers for the action of some Polish group. Bibliography: 39 titles.

Space Robotics Challenge

Data.gov (United States)

National Aeronautics and Space Administration — The Space Robotics Challenge seeks to infuse robot autonomy from the best and brightest research groups in the robotics community into NASA robots for future...

The past and space

DEFF Research Database (Denmark)

Lund, Christian

2013-01-01

of legitimate forms of land control, complex combinations of claims emerge. The ubiquity of ‘the past’ in African politics and the increasing competition over space suggest that the naturalness with which some refer to the past and others conceive of space should be under constant scrutiny. Based on work...... that competing social elite groups instrumentalize. Each group sees its interests best served by a particular reading of the past and a particular conception of space....

Human space flight and future major space astrophysics missions: servicing and assembly

Science.gov (United States)

Thronson, Harley; Peterson, Bradley M.; Greenhouse, Matthew; MacEwen, Howard; Mukherjee, Rudranarayan; Polidan, Ronald; Reed, Benjamin; Siegler, Nicholas; Smith, Hsiao

2017-09-01

Some concepts for candidate future "flagship" space observatories approach the payload limits of the largest launch vehicles planned for the next few decades, specifically in the available volume in the vehicle fairing. This indicates that an alternative to autonomous self-deployment similar to that of the James Webb Space Telescope will eventually be required. Moreover, even before this size limit is reached, there will be significant motivation to service, repair, and upgrade in-space missions of all sizes, whether to extend the life of expensive facilities or to replace outworn or obsolete onboard systems as was demonstrated so effectively by the Hubble Space Telescope program. In parallel with these challenges to future major space astronomy missions, the capabilities of in-space robotic systems and the goals for human space flight in the 2020s and 2030s offer opportunities for achieving the most exciting science goals of the early 21st Century. In this paper, we summarize the history of concepts for human operations beyond the immediate vicinity of the Earth, the importance of very large apertures for scientific discovery, and current capabilities and future developments in robot- and astronaut-enabled servicing and assembly.

Evaluation of the effects of subgingival injection of Simvastatin on space re-opening after orthodontic space closure in adults

Directory of Open Access Journals (Sweden)

Arezoo Jahanbin

2016-03-01

Full Text Available Background. This clinical trial evaluated the effect of Simvastatin on space re-opening after orthodontic space closure and its effect on the gingival index (GI and clinical attachment loss (CAL. Methods. 16 females, 25‒40 years old, with spaces between anterior mandibular teeth due to chronic periodontitis were participated in this study. The patients were randomly divided into control and experimental groups. In the experimental group, 1.2% Simvastatin gel and in the control group, 0.9% sodium chloride as a placebo was injected into the pocket depth of the six anterior teeth. The amount of space reopening, GI and CAL were measured. Results. No serious complications were observed during interventions and follow-up periods. Space re-opening was significantly reduced in patients receiving Simvastatin (P < 0.001. Moreover, GI reduction was significantly greater in Sim-vastatin group compared to the control group (P < 0.001. However, CAL did not demonstrate a significant difference between the groups. Conclusion. Simvastatin may decrease space re-opening after orthodontic space closure in human anterior teeth.

14 CFR 21.5 - Airplane or Rotorcraft Flight Manual.

Science.gov (United States)

2010-01-01

... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Airplane or Rotorcraft Flight Manual. 21.5... CERTIFICATION PROCEDURES FOR PRODUCTS AND PARTS General § 21.5 Airplane or Rotorcraft Flight Manual. (a) With each airplane or rotorcraft that was not type certificated with an Airplane or Rotorcraft Flight Manual...

SW21 Summary Report

Energy Technology Data Exchange (ETDEWEB)

Juarez, A. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

2016-02-10

Los Alamos and Lawrence Livermore National Laboratories hosted the tenth annual Strategic Weapons in the 21st Century Conference (SW21) on 21 January 2016 to reinforce the national commitment to leadership and institutional excellence for nuclear deterrence. The event has been successful over the years in drawing together a diverse, high-level group of policy makers and experts from multiple disciplines to engage in informed dialogue on topics related to strategic weapons in national and international security.

Vision 21: The NASA strategic plan

Science.gov (United States)

1992-01-01

The NASA Strategic Plan, Vision 21, is a living roadmap to the future to guide the men and women of the NASA team as they ensure U.S. leadership in space exploration and aeronautics research. This multiyear plan consists of a set of programs and activities that will retain our leadership in space science and the exploration of the solar system; help rebuild our nation's technology base and strengthen our leadership in aviation and other key industries; encourage commercial applications of space technology; use the unique perspective of space to better understand our home planet; provide the U.S. and its partners with a permanent space based research facility; expand on the legacy of Apollo and initiate precursor activities to establish a lunar base; and allow us a journey into tomorrow, journey to another planet (Mars), and beyond.

Space Science at Los Alamos National Laboratory

Science.gov (United States)

Smith, Karl

2017-09-01

The Space Science and Applications group (ISR-1) in the Intelligence and Space Research (ISR) division at the Los Alamos National Laboratory lead a number of space science missions for civilian and defense-related programs. In support of these missions the group develops sensors capable of detecting nuclear emissions and measuring radiations in space including γ-ray, X-ray, charged-particle, and neutron detection. The group is involved in a number of stages of the lifetime of these sensors including mission concept and design, simulation and modeling, calibration, and data analysis. These missions support monitoring of the atmosphere and near-Earth space environment for nuclear detonations as well as monitoring of the local space environment including space-weather type events. Expertise in this area has been established over a long history of involvement with cutting-edge projects continuing back to the first space based monitoring mission Project Vela. The group's interests cut across a large range of topics including non-proliferation, space situational awareness, nuclear physics, material science, space physics, astrophysics, and planetary physics.

q-deformed phase-space and its lattice structure

International Nuclear Information System (INIS)

Wess, J.

1998-01-01

Quantum groups lead to an algebraic structure that can be realized on quantum spaces. These are non-commutative spaces that inherit a well-defined mathematical structure from the quantum group symmetry. In turn, such quantum spaces can be interpreted as non-commutative configuration spaces for physical systems. We study the non-commutative Euclidean space that is based on the quantum group SO q (3)

Equivalence groups of (2+1) dimensional diffusion equation

OpenAIRE

Özer, Saadet

2017-01-01

If a given set of differential equations contain somearbitrary functions, parameters, we have in fact a family of sets of equationsof the same structure. Almost all field equations of classical physichs havethis property, representing different materials with various paramaters.  Equivalence groups are defined as the groupof transformations which leave a given family of differential equationsinvariant. Therefore, equivalence group of family of differential equations isan important area within...

14 CFR 39.21 - Where can I get information about FAA-approved alternative methods of compliance?

Science.gov (United States)

2010-01-01

... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Where can I get information about FAA-approved alternative methods of compliance? 39.21 Section 39.21 Aeronautics and Space FEDERAL AVIATION... information about FAA-approved alternative methods of compliance? Each airworthiness directive identifies the...

Wigner functions from the two-dimensional wavelet group.

Science.gov (United States)

Ali, S T; Krasowska, A E; Murenzi, R

2000-12-01

Following a general procedure developed previously [Ann. Henri Poincaré 1, 685 (2000)], here we construct Wigner functions on a phase space related to the similitude group in two dimensions. Since the group space in this case is topologically homeomorphic to the phase space in question, the Wigner functions so constructed may also be considered as being functions on the group space itself. Previously the similitude group was used to construct wavelets for two-dimensional image analysis; we discuss here the connection between the wavelet transform and the Wigner function.

Homogeneous Spaces and Equivariant Embeddings

CERN Document Server

Timashev, DA

2011-01-01

Homogeneous spaces of linear algebraic groups lie at the crossroads of algebraic geometry, theory of algebraic groups, classical projective and enumerative geometry, harmonic analysis, and representation theory. By standard reasons of algebraic geometry, in order to solve various problems on a homogeneous space it is natural and helpful to compactify it keeping track of the group action, i.e. to consider equivariant completions or, more generally, open embeddings of a given homogeneous space. Such equivariant embeddings are the subject of this book. We focus on classification of equivariant em

Fundamental study on the size and inter-key spacing of numeric keys for touch screen.

Science.gov (United States)

Harada, H; Katsuura, T; Kikuchi, Y

1996-12-01

The purpose of this study was to reveal the optimum size and inter-key spacing of numeric square keys for touch screens. Six male students (22-25 years old) and three female students (21-24 years old) volunteered as subjects for this experiment. Each subject took part in data entry tasks using numeric square keys of touch devices. The sizes of keys were 6, 12, 21, 30 and 39 mm and each the inter-key spacing was 0, 3, 6, 12 and 21 mm. Response times with key sizes of 6 and 12 mm were significantly slower than with key sizes of 21 and 30 mm (p touch screens should be more than 21 mm and optimum inter-key spacing should be from 3 to 6 mm. Optimum key size, however, must be selected with regard to the limitation of screen size.

The cohomology of orbit spaces of certain free circle group actions

Indian Academy of Sciences (India)

Abstract. Suppose that G = S1 acts freely on a finitistic space X whose (mod p) cohomology ring is isomorphic to that of a lens space L2m−1(p;q1,...,qm) or S1 ×. CPm−1. The mod p index of the action is defined to be the largest integer n such that αn = 0, where α ϵ H2(X/G; Zp) is the nonzero characteristic class of the S1-.

21 CFR 226.20 - Buildings.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 4 2010-04-01 2010-04-01 false Buildings. 226.20 Section 226.20 Food and Drugs... Facilities and Equipment § 226.20 Buildings. Buildings in which Type A medicated article(s) are manufactured... operation for their intended purpose. The building shall: (a) Provide adequate space for the orderly...

The new Zintl phases Eu{sub 21}Cd{sub 4}Sb{sub 18} and Eu{sub 21}Mn{sub 4}Sb{sub 18}

Energy Technology Data Exchange (ETDEWEB)

Wang, Yi; Darone, Gregory M.; Bobev, Svilen, E-mail: bobev@udel.edu

2016-06-15

Crystals of two new Zintl compounds, Eu{sub 21}Mn{sub 4}Sb{sub 18} and Eu{sub 21}Cd{sub 4}Sb{sub 18} have been synthesized using the molten metal flux method, and their structures have been established by single-crystal X-ray diffraction. Both compounds are isotypic and crystallize in the monoclinic space group C2/m (No. 12, Z=4). The structures are based on edge- and corner-shared MnSb{sub 4} or CdSb{sub 4} tetrahedra, which make octameric [Mn{sub 8}Sb{sub 22}] or [Cd{sub 8}Sb{sub 22}] polyanions. Homoatomic Sb–Sb bonds are present in both structures. The Eu atoms take the role of Eu{sup 2+}cations with seven unpaired 4f electrons, as suggested by the temperature-dependent magnetization measurements. The magnetic susceptibilities of Eu{sub 21}Mn{sub 4}Sb{sub 18} and Eu{sub 21}Cd{sub 4}Sb{sub 18} indicate that both phases order anti-ferromagnetically with Néel temperatures of ca. 7 K and ca. 10 K, respectively. The unpaired 3d electrons of the Mn atoms in Eu{sub 21}Mn{sub 4}Sb{sub 18} do contribute to the magnetic response, however, the bulk magnetization measurements do not provide evidence for long-range ordering of the Mn spins down to 5 K. Electrical resistivity measurements suggest that both compounds are narrow band gap semiconductors. - Graphical abstract: Eu{sub 21}Mn{sub 4}Sb{sub 18} and Eu{sub 21}Cd{sub 4}Sb{sub 18} have complex monoclinic structures, based on MnSb{sub 4} and CdSb{sub 4} tetrahedra, both edge- and corner-shared. A perspective of the crystal structure is shown, as viewed along the b axis. Display Omitted - Highlights: • Eu{sub 21}Mn{sub 4}Sb{sub 18} and Eu{sub 21}Cd{sub 4}Sb{sub 18} are novel compounds in the respective ternary phase diagrams. • For both structures, the Zintl-Klemm rules are followed, and both are small gap semiconductors. • Eu{sub 21}Mn{sub 4}Sb{sub 18} and Eu{sub 21}Cd{sub 4}Sb{sub 18} are air-stable Zintl phases and could be new thermoelectric materials.

INFLUENCE OF ECOLOGICAL GROUP COMPOSITION, PLANTATION SPACING AND ARRANGEMENT IN THE RESTORATION OF RIPARIAN FOREST ON RESERVOIR SHORES

Directory of Open Access Journals (Sweden)

Alvaro Augusto Vieira Soares

2016-01-01

Full Text Available This work aimed to assess the effect of spacing, arrangement and ecological group composition of planted seedlings on the restoration process of artificial reservoir shores in southeastern Brazil. The assessments were performed 12 years after the settlement of the experiment in which five mixed stand models were tested. First, a general evaluation of the stand was performed when we surveyed the overstory and understory, seed bank and soil for chemical analysis.Then, the restoration indicators survival of planted trees, basal area and density of the tree community, litter accumulated on the soil and canopy closure index were utilized to compare the plantation models and to assess the influence the experimental factors on these parameters. In the general analysis, we found that the studied stand presents low diversity, poor regeneration, and seed bank dominated mostly by one planted exotic tree species and weeds, which may jeopardize the self- maintenance of the stand in the future. The factor that most influenced the models was the ecological group composition with the best performance found for models in which both pioneer and non-pioneer groups were used. Probably, the plantation arrangement and spacing did not have greater influence due to both plant mortality and natural regeneration that has developed to this age. Hence, it is not recommended the use of only pioneer species in the implantation of riparian forest and the proportion of 50% pioneers and 50% non-pioneers using as much species as possible is indicated for areas that might present constraints for the natural regeneration.

Predicting Cost and Schedule Growth for Military and Civil Space Systems

National Research Council Canada - National Science Library

Rusnock, Christina F

2008-01-01

... for predicting cost and schedule growth. The analysis consists of logistic and multiple regression to assess 21 Department of Defense and 71 National Aeronautics and Space Administration (NASA) space programs...

Better library and learning space projects, trends, ideas

CERN Document Server

Watson, Les

2014-01-01

What are the most important things a 21st-century library should do with its space? This title includes chapters that address this critical question, capturing the insights and practical ideas of international librarians, educators and designers to offer you a 'creative resource bank' that helps to transform your library and learning spaces.

14 CFR 21.125 - Production inspection system: Materials Review Board.

Science.gov (United States)

2010-01-01

... § 21.125 Production inspection system: Materials Review Board. Link to an amendment published at 74 FR... Materials Review Board action for at least two years. (b) The production inspection system required in § 21... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Production inspection system: Materials...

Polymorphonuclear leucocyte dysfunction during short term metabolic changes from normo- to hyperglycemia in type 1 (insulin dependent) diabetic patients

DEFF Research Database (Denmark)

Kjersem, H; Hilsted, J; Madsbad, S

1988-01-01

Polymorphonuclear leucocyte (PMN) ingestion of particles coated with lipopolysaccharide (LPS) from Escherichia coli was compared to other PMN functions in seven patients with insulin dependent diabetes mellitus (IDDM) during short-term controlled metabolic changes from normo- to hyperglycemia...... without ketoacidosis. Factors known to interfere with PMN functions were excluded. PMN ingestion of particles coated with both LPS and bovine serum albumin became reduced from normo- to hyperglycemia. PMN motility was impaired in IDDM, but did not seem to be affected by short-term changes in metabolic...... control. PMN metabolism did not change from normo-to hyperglycemia. Particle-uptake by diabetic PMN is impaired after short term hyperglycemia in the range normally occurring in diabetics in every-day life....

Space Transportation Analysis and Design (Reissue A)

Science.gov (United States)

1993-02-17

RECOVERABLE LAUNCH VEHICLES ..................... 3-12 1. Domestic (STS Space Shuttle) ....................................... 3-12 2. Foreign (CIS Energia ...affects solar heating of the spacecraft and the availability of solar energy for generating spacecraft power. 2-1 Table 2-1. Typical Orbits and...Foreign (CIS Energia Buran) The CIS Energia , which became operational in 1987, was developed to launch a variety of heavy payloads including the Buran

14 CFR 21.617 - Issue of letters of TSO design approval: import appliances.

Science.gov (United States)

2010-01-01

...: import appliances. 21.617 Section 21.617 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION... Order Authorizations § 21.617 Issue of letters of TSO design approval: import appliances. (a) A letter of TSO design approval may be issued for an appliance that is manufactured in a foreign country with...

2-[1-(Methylsulfanylnaphtho[2,1-b]furan-2-yl]acetic acid

Directory of Open Access Journals (Sweden)

Uk Lee

2008-02-01

Full Text Available The title compound, C15H12O3S, was prepared by alkaline hydrolysis of ethyl 2-{1-(methylsulfanylnaphtho[2,1-b]furan-2-yl}acetate. The crystal structure is stabilized by CH2—H...π interactions between the methyl H atoms of the methylsulfanyl substituent and the central benzene ring of the naphthofuran system, and by inversion-related intermolecular O—H...O hydrogen bonds between the carboxyl groups.

The character of free topological groups II

Directory of Open Access Journals (Sweden)

Peter Nickolas

2005-04-01

Full Text Available A systematic analysis is made of the character of the free and free abelian topological groups on metrizable spaces and compact spaces, and on certain other closely related spaces. In the first case, it is shown that the characters of the free and the free abelian topological groups on X are both equal to the “small cardinal” d if X is compact and metrizable, but also, more generally, if X is a non-discrete k!-space all of whose compact subsets are metrizable, or if X is a non-discrete Polish space. An example is given of a zero-dimensional separable metric space for which both characters are equal to the cardinal of the continuum. In the case of a compact space X, an explicit formula is derived for the character of the free topological group on X involving no cardinal invariant of X other than its weight; in particular the character is fully determined by the weight in the compact case. This paper is a sequel to a paper by the same authors in which the characters of the free groups were analysed under less restrictive topological assumptions.

Damped soft phonons and diffuse scattering in 40%Pb(Mg1/3Nb2/3)O3-60%PbTiO3

International Nuclear Information System (INIS)

Stock, C.; Ellis, D.; Swainson, I. P.; Xu, Guangyong; Hiraka, H.; Shirane, G.; Zhong, Z.; Luo, H.; Zhao, X.; Viehland, D.; Birgeneau, R. J.

2006-01-01

Using neutron elastic and inelastic scattering and high-energy x-ray diffraction, we present a comparison of 40% Pb(Mg 1/3 Nb 2/3 )O 3 -60% PbTiO 3 (PMN-60PT) with pure Pb(Mg 1/3 Nb 2/3 )O 3 (PMN) and PbTiO 3 (PT). We measure the structural properties of PMN-60PT to be identical to pure PT, however, the lattice dynamics are exactly that previously found in relaxors PMN and Pb(Zn 1/3 Nb 2/3 )O 3 (PZN). PMN-60PT displays a well-defined macroscopic structural transition from a cubic to tetragonal unit cell at 550 K. The diffuse scattering is shown to be weak indicating that the structural distortion is long-range in PMN-60PT and short-range polar correlations (polar nanoregions) are not present. Even though polar nanoregions are absent, the soft optic mode is short-lived for wave vectors near the zone center. Therefore PMN-60PT displays the same waterfall effect as prototypical relaxors PMN and PZN. We conclude that it is random fields resulting from the intrinsic chemical disorder which is the reason for the broad transverse optic mode observed in PMN and PMN-60PT near the zone center and not due to the formation of short-ranged polar correlations. Through our comparison of PMN, PMN-60PT, and pure PT, we interpret the dynamic and static properties of the PMN-xPT system in terms of a random field model in which the cubic anisotropy term dominates with increasing doping of PbTiO 3

Geometrical aspects of quantum spaces

International Nuclear Information System (INIS)

Ho, P.M.

1996-01-01

Various geometrical aspects of quantum spaces are presented showing the possibility of building physics on quantum spaces. In the first chapter the authors give the motivations for studying noncommutative geometry and also review the definition of a Hopf algebra and some general features of the differential geometry on quantum groups and quantum planes. In Chapter 2 and Chapter 3 the noncommutative version of differential calculus, integration and complex structure are established for the quantum sphere S 1 2 and the quantum complex projective space CP q (N), on which there are quantum group symmetries that are represented nonlinearly, and are respected by all the aforementioned structures. The braiding of S q 2 and CP q (N) is also described. In Chapter 4 the quantum projective geometry over the quantum projective space CP q (N) is developed. Collinearity conditions, coplanarity conditions, intersections and anharmonic ratios is described. In Chapter 5 an algebraic formulation of Reimannian geometry on quantum spaces is presented where Riemannian metric, distance, Laplacian, connection, and curvature have their quantum counterparts. This attempt is also extended to complex manifolds. Examples include the quantum sphere, the complex quantum projective space and the two-sheeted space. The quantum group of general coordinate transformations on some quantum spaces is also given

ORF Alignment: NC_004431 [GENIUS II[Archive

Lifescience Database Archive (English)

Full Text Available stal ... Structure Of Vshp_bpp21 In Space Group C2 pdb|1TD3|B ... Chain B, Crystal Structure Of Vshp_bpp21 In Space...f Vshp_bpp21 ... In Space Group C2 gb|AAA32345.1| capsid protein small ... subunit ... L

Phase space representation of neutron monitor count rate and atmospheric electric field in relation to solar activity in cycles 21 and 22.

Science.gov (United States)

Silva, H G; Lopes, I

Heliospheric modulation of galactic cosmic rays links solar cycle activity with neutron monitor count rate on earth. A less direct relation holds between neutron monitor count rate and atmospheric electric field because different atmospheric processes, including fluctuations in the ionosphere, are involved. Although a full quantitative model is still lacking, this link is supported by solid statistical evidence. Thus, a connection between the solar cycle activity and atmospheric electric field is expected. To gain a deeper insight into these relations, sunspot area (NOAA, USA), neutron monitor count rate (Climax, Colorado, USA), and atmospheric electric field (Lisbon, Portugal) are presented here in a phase space representation. The period considered covers two solar cycles (21, 22) and extends from 1978 to 1990. Two solar maxima were observed in this dataset, one in 1979 and another in 1989, as well as one solar minimum in 1986. Two main observations of the present study were: (1) similar short-term topological features of the phase space representations of the three variables, (2) a long-term phase space radius synchronization between the solar cycle activity, neutron monitor count rate, and potential gradient (confirmed by absolute correlation values above ~0.8). Finally, the methodology proposed here can be used for obtaining the relations between other atmospheric parameters (e.g., solar radiation) and solar cycle activity.

Axiomatics of uniform space-time models

International Nuclear Information System (INIS)

Levichev, A.V.

1983-01-01

The mathematical statement of space-time axiomatics of the special theory of relativity is given; it postulates that the space-time M is the binding single boundary Hausedorf local-compact four-dimensional topological space with the given order. The theorem is proved: if the invariant order in the four-dimensional group M is given by the semi-group P, which contingency K contains inner points , then M is commutative. The analogous theorem is correct for the group of two and three dimensionalities

Space for Interaction

DEFF Research Database (Denmark)

Jørgensen, Mariane Ellen; Folmer, Mette Blicher; Mullins, Michael

SPACE FOR INTERACTION QUALIFYING GROUP TREATMENT FOR PATIENTS WITH CHRONIC PAIN THROUGH OPTIMIZATION(?) OF SPACE. A RANDOMIZED PILOT STUDY. In a Ph-D. Mariane Ellen Jørgensen / Nurse + psykoterapist / maej@rn.dk / Pain Center / Aalborg University Hospital / Denmark / Mette Blicher Folmer / Archit...

Phonological and semantic processing during comprehension in Wernicke's aphasia: An N400 and Phonological Mapping Negativity Study.

Science.gov (United States)

Robson, Holly; Pilkington, Emma; Evans, Louise; DeLuca, Vincent; Keidel, James L

2017-06-01

Comprehension impairments in Wernicke's aphasia are thought to result from a combination of impaired phonological and semantic processes. However, the relationship between these cognitive processes and language comprehension has only been inferred through offline neuropsychological tasks. This study used ERPs to investigate phonological and semantic processing during online single word comprehension. EEG was recorded in a group of Wernicke's aphasia n=8 and control participants n=10 while performing a word-picture verification task. The N400 and Phonological Mapping Negativity/Phonological Mismatch Negativity (PMN) event-related potential components were investigated as an index of semantic and phonological processing, respectively. Individuals with Wernicke's aphasia displayed reduced and inconsistent N400 and PMN effects in comparison to control participants. Reduced N400 effects in the WA group were simulated in the control group by artificially degrading speech perception. Correlation analyses in the Wernicke's aphasia group found that PMN but not N400 amplitude was associated with behavioural word-picture verification performance. The results confirm impairments at both phonological and semantic stages of comprehension in Wernicke's aphasia. However, reduced N400 responses in Wernicke's aphasia are at least partially attributable to earlier phonological processing impairments. The results provide further support for the traditional model of Wernicke's aphasia which claims a causative link between phonological processing and language comprehension impairments. Copyright © 2017 Elsevier Ltd. All rights reserved.

Preparation and structural properties of nonlinear optical borates K{sub 2(1-x)}Rb{sub 2x}Al{sub 2}B{sub 2}O{sub 7}, 0 < x < 0.75

Energy Technology Data Exchange (ETDEWEB)

Atuchin, V.V., E-mail: atuchin@thermo.isp.nsc.ru [Laboratory of Optical Materials and Structures, Institute of Semiconductor Physics, SB RAS, Novosibirsk 90, 630090 (Russian Federation); Bazarov, B.G. [Laboratory of Oxide Systems, Baikal Institute of Nature Management, SB RAS, Ulan-Ude 47, 670047 (Russian Federation); Gavrilova, T.A. [Laboratory of Nanodiagnostics and Nanolithography, Institute of Semiconductor Physics, SB RAS, Novosibirsk 630090 (Russian Federation); Grossman, V.G. [Laboratory of Oxide Systems, Baikal Institute of Nature Management, SB RAS, Ulan-Ude 47, 670047 (Russian Federation); Molokeev, M.S. [Laboratory of Crystal Physics, Institute of Physics, SB RAS, Krasnoyarsk 660036 (Russian Federation); Bazarova, Zh.G. [Laboratory of Oxide Systems, Baikal Institute of Nature Management, SB RAS, Ulan-Ude 47, 670047 (Russian Federation)

2012-02-25

Highlights: Black-Right-Pointing-Pointer Solid solutions K{sub 2(1-x)}Rb{sub 2x}Al{sub 2}B{sub 2}O{sub 7} are synthesized over wide composition range up to x {approx} 0.83. Black-Right-Pointing-Pointer Crystal structure of K{sub 2(1-x)}Rb{sub 2x}Al{sub 2}B{sub 2}O{sub 7} solutions is determined in space group P321. Black-Right-Pointing-Pointer Second harmonic generation is observed in KRbAl{sub 2}B{sub 2}O{sub 7}. Black-Right-Pointing-Pointer Drastic variation of cell parameters is found over KABO-type crystal family. - Abstract: The structures of K{sub 2(1-x)}Rb{sub 2x}Al{sub 2}B{sub 2}O{sub 7}, x = 0.25, 0.5, 0.75, have been determined in space group P321 through Rietveld analysis of X-ray powder diffraction data. The solubility limit in K{sub 2(1-x)}Rb{sub 2x}Al{sub 2}B{sub 2}O{sub 7} crystals has been estimated as x {approx} 0.83-0.9. Nonlinear optical properties of KRbAl{sub 2}B{sub 2}O{sub 7} have been verified by powder Kurtz-Perry method. Mechanisms of structural parameter variation in K{sub 2}Al{sub 2}B{sub 2}O{sub 7} crystal family have been discussed.

Solid-state epitaxial effects in structurally diphasic xerogel of Pb(Mg1/3Nb2/3)O3

International Nuclear Information System (INIS)

Ravindranathan, P.; Komarneni, S.; Roy, R.

1990-01-01

Lead magnesium niobate (PMN), Pb(Mg 1/3 Nb 2/3 )O 3 , with perovskite structure has been prepared using structurally diphasic PMN gels. The diphasic gels were made using various concentrations of perovskite PMN seeds. The unseeded gel calcined at 775 degrees C for 2 h gave ∼ 98% of perovskite PMN phase. The use of 1% PMN perovskite seed not only led to a pure perovskite phase but also lowered the crystallization temperature of these gels by about 75 degrees C. These results show that isostructural seeding helps to lower the crystallization temperature of perovskite PMN phase

Human neutrophils facilitate tumor cell transendothelial migration.

LENUS (Irish Health Repository)

Wu, Q D

2012-02-03

Tumor cell extravasation plays a key role in tumor metastasis. However, the precise mechanisms by which tumor cells migrate through normal vascular endothelium remain unclear. In this study, using an in vitro transendothelial migration model, we show that human polymorphonuclear neutrophils (PMN) assist the human breast tumor cell line MDA-MB-231 to cross the endothelial barrier. We found that tumor-conditioned medium (TCM) downregulated PMN cytocidal function, delayed PMN apoptosis, and concomitantly upregulated PMN adhesion molecule expression. These PMN treated with TCM attached to tumor cells and facilitated tumor cell migration through different endothelial monolayers. In contrast, MDA-MB-231 cells alone did not transmigrate. FACScan analysis revealed that these tumor cells expressed high levels of intercellular adhesion molecule-1 (ICAM-1) but did not express CD11a, CD11b, or CD18. Blockage of CD11b and CD18 on PMN and of ICAM-1 on MDA-MB-231 cells significantly attenuated TCM-treated, PMN-mediated tumor cell migration. These tumor cells still possessed the ability to proliferate after PMN-assisted transmigration. These results indicate that TCM-treated PMN may serve as a carrier to assist tumor cell transendothelial migration and suggest that tumor cells can exploit PMN and alter their function to facilitate their extravasation.

Local Agenda 21 and renewable energy

Energy Technology Data Exchange (ETDEWEB)

NONE

2000-07-01

This report summarises the findings of a study to examine the progress of the Local Agenda 21 (LA21) plans of local authorities relevant to renewable energy. Current UK policy and funding of renewable energy, the development of LA21 in the UK, the research methodology, and the results of a questionnaire survey are discussed. The findings of consultations with local LA21 groups, discussions of good practice examples and approaches, and final recommendations are outlined. (UK)

Dynamics of infinite-dimensional groups the Ramsey-Dvoretzky-Milman phenomenon

CERN Document Server

Pestov, Vladimir

2006-01-01

The "infinite-dimensional groups" in the title refer to unitary groups of Hilbert spaces, the infinite symmetric group, groups of homeomorphisms of manifolds, groups of transformations of measure spaces, etc. The book presents an approach to the study of such groups based on ideas from geometric functional analysis and from exploring the interplay between dynamical properties of those groups, combinatorial Ramsey-type theorems, and the phenomenon of concentration of measure. The dynamics of infinite-dimensional groups is very much unlike that of locally compact groups. For instance, every locally compact group acts freely on a suitable compact space (Veech). By contrast, a 1983 result by Gromov and Milman states that whenever the unitary group of a separable Hilbert space continuously acts on a compact space, it has a common fixed point. In the book, this new fast-growing theory is built strictly from well-understood examples up. The book has no close counterpart and is based on recent research articles. At t...

Causal symmetric spaces

CERN Document Server

Olafsson, Gestur; Helgason, Sigurdur

1996-01-01

This book is intended to introduce researchers and graduate students to the concepts of causal symmetric spaces. To date, results of recent studies considered standard by specialists have not been widely published. This book seeks to bring this information to students and researchers in geometry and analysis on causal symmetric spaces.Includes the newest results in harmonic analysis including Spherical functions on ordered symmetric space and the holmorphic discrete series and Hardy spaces on compactly casual symmetric spacesDeals with the infinitesimal situation, coverings of symmetric spaces, classification of causal symmetric pairs and invariant cone fieldsPresents basic geometric properties of semi-simple symmetric spacesIncludes appendices on Lie algebras and Lie groups, Bounded symmetric domains (Cayley transforms), Antiholomorphic Involutions on Bounded Domains and Para-Hermitian Symmetric Spaces

First meeting of the International Working Group on Advanced Technologies for Water Cooled Reactors, Vienna, 18-21 May 1987. (Pt. 2)

International Nuclear Information System (INIS)

1987-12-01

The First Meeting of the IAEA International Working Group on Advanced Technologies for Water Cooled Reactors was held in Vienna, Austria from 18-21 May 1987. The Summary Report (Pt. 2) contains the papers which review the national programmes in the field of Advanced Technologies for Water Cooled Reactors and other presentations at the Meeting. A separate abstract was prepared for each of the 10 papers presented at this meeting. Refs, figs

Evaluation of the effects of subgingival injection of Simvastatin on space re-opening after orthodontic space closure in adults.

Science.gov (United States)

Jahanbin, Arezoo; Abtahi, Mostafa; Namdar, Parastoo; Heravi, Farzin; Sadeghi, Fatemeh; Arab, Hamidreza; Shafaee, Hooman

2016-01-01

Background. This clinical trial evaluated the effect of Simvastatin on space re-opening after orthodontic space closure and its effect on the gingival index (GI) and clinical attachment loss (CAL). Methods. 16 females, 25-40 years old, with spaces between anterior mandibular teeth due to chronic periodontitis were participated in this study. The patients were randomly divided into control and experimental groups. In the experimental group, 1.2% Simvastatin gel and in the control group, 0.9% sodium chloride as a placebo was injected into the pocket depth of the six anterior teeth. The amount of space reopening, GI and CAL were measured. Results. No serious complications were observed during interventions and follow-up periods. Space re-opening was significantly reduced in patients receiving Simvastatin (P space re-opening after orthodontic space closure in human anterior teeth.

q-deformed Minkowski space

International Nuclear Information System (INIS)

Ogievetsky, O.; Pillin, M.; Schmidke, W.B.; Wess, J.; Zumino, B.

1993-01-01

In this lecture I discuss the algebraic structure of a q-deformed four-vector space. It serves as a good example of quantizing Minkowski space. To give a physical interpretation of such a quantized Minkowski space we construct the Hilbert space representation and find that the relevant time and space operators have a discrete spectrum. Thus the q-deformed Minkowski space has a lattice structure. Nevertheless this lattice structure is compatible with the operation of q-deformed Lorentz transformations. The generators of the q-deformed Lorentz group can be represented as linear operators in the same Hilbert space. (orig.)

The third spatial dimension risk approach for individual risk and group risk in multiple use of space

International Nuclear Information System (INIS)

Suddle, Shahid; Ale, Ben

2005-01-01

Buildings above roads and railways are examples of multiple use of space. Safety is one of the critical issues for such projects. Risk analyses can be undertaken to investigate what safety measures that are required to realise these projects. The results of these analyses can also be compared to risk acceptance criteria, if they are applicable. In The Netherlands, there are explicit criteria for acceptability of individual risk and societal risk. Traditionally calculations of individual risk result in contours of equal risk on a map and thus are considered in two-dimensional space only. However, when different functions are layered the third spatial dimension, height, becomes an important parameter. The various activities and structures above and below each other impose mutual risks. There are no explicit norms or policies about how to deal with the individual or group risk approach in the third dimension. This paper proposes an approach for these problems and gives some examples. Finally, the third dimension risk approach is applied in a case study of Bos en Lommer, Amsterdam

Making media work in space: an interdisciplinary perspective on media and communication requirements for current and future space communities

Science.gov (United States)

Babidge, S.; Cokley, J.; Gordon, F.; Louw, E.

2005-10-01

As humans expand into space communities will form. These have already begun to form in small ways, such as long-duration missions on the International Space Station and the space shuttle, and small-scale tourist excursions into space. Social, behavioural and communications data emerging from such existing communities in space suggest that the physically-bounded, work-oriented and traditionally male-dominated nature of these extremely remote groups present specific problems for the resident astronauts, groups of them viewed as ‘communities’, and their associated groups who remain on Earth, including mission controllers, management and astronauts’ families. Notionally feminine group attributes such as adaptive competence, social adaptation skills and social sensitivity will be crucial to the viability of space communities and in the absence of gender equity, ‘staying in touch’ by means of ‘news from home’ becomes more important than ever. A template of news and media forms and technologies is suggested to service those needs and enhance the social viability of future terraforming activities.

Proceedings of the Conference of the International Group for the Psychology of Mathematics Education (21st, Lahti, Finland, July 14-19, 1997). Volume 2.

Science.gov (United States)

Pehkonen, Erkki, Ed.

The second volume of the proceedings of 21st annual meeting of the International Group for the Psychology of Mathematics Education contains the following papers: (1) "The Dilemma of Transparency: Seeing and Seeing through Talk in the Mathematics Classroom" (J. Adler); (2) "Abstraction is Hard in Computer-Science Too" (D.…

Group covariance and metrical theory

International Nuclear Information System (INIS)

Halpern, L.

1983-01-01

The a priori introduction of a Lie group of transformations into a physical theory has often proved to be useful; it usually serves to describe special simplified conditions before a general theory can be worked out. Newton's assumptions of absolute space and time are examples where the Euclidian group and translation group have been introduced. These groups were extended to the Galilei group and modified in the special theory of relativity to the Poincare group to describe physics under the given conditions covariantly in the simplest way. The criticism of the a priori character leads to the formulation of the general theory of relativity. The general metric theory does not really give preference to a particular invariance group - even the principle of equivalence can be adapted to a whole family of groups. The physical laws covariantly inserted into the metric space are however adapted to the Poincare group. 8 references

The moduli space of instantons on an ALE space from 3d $\\mathcal{N}=4$ field theories

CERN Document Server

Mekareeya, Noppadol

2015-01-01

The moduli space of instantons on an ALE space is studied using the moduli space of $\\mathcal{N}=4$ field theories in three dimensions. For instantons in a simple gauge group $G$ on $\\mathbb{C}^2/\\mathbb{Z}_n$, the Hilbert series of such an instanton moduli space is computed from the Coulomb branch of the quiver given by the affine Dynkin diagram of $G$ with flavour nodes of unitary groups attached to various nodes of the Dynkin diagram. We provide a simple prescription to determine the ranks and the positions of these flavour nodes from the order of the orbifold $n$ and from the residual subgroup of $G$ that is left unbroken by the monodromy of the gauge field at infinity. For $G$ a simply laced group of type $A$, $D$ or $E$, the Higgs branch of such a quiver describes the moduli space of instantons in projective unitary group $PU(n) \\cong U(n)/U(1)$ on orbifold $\\mathbb{C}^2/\\hat{G}$, where $\\hat{G}$ is the discrete group that is in McKay correspondence to $G$. Moreover, we present the quiver whose Coulomb ...

Space station propulsion requirements study

Science.gov (United States)

Wilkinson, C. L.; Brennan, S. M.

1985-01-01

Propulsion system requirements to support Low Earth Orbit (LEO) manned space station development and evolution over a wide range of potential capabilities and for a variety of STS servicing and space station operating strategies are described. The term space station and the overall space station configuration refers, for the purpose of this report, to a group of potential LEO spacecraft that support the overall space station mission. The group consisted of the central space station at 28.5 deg or 90 deg inclinations, unmanned free-flying spacecraft that are both tethered and untethered, a short-range servicing vehicle, and a longer range servicing vehicle capable of GEO payload transfer. The time phasing for preferred propulsion technology approaches is also investigated, as well as the high-leverage, state-of-the-art advancements needed, and the qualitative and quantitative benefits of these advancements on STS/space station operations. The time frame of propulsion technologies applicable to this study is the early 1990's to approximately the year 2000.

SENSITIVE 21 cm OBSERVATIONS OF NEUTRAL HYDROGEN IN THE LOCAL GROUP NEAR M31

Energy Technology Data Exchange (ETDEWEB)

Wolfe, Spencer A.; Pisano, D. J. [Dept. of Physics and Astronomy, West Virginia University, Morgantown, WV 26506 (United States); Lockman, Felix J., E-mail: swolfe4@mix.wvu.edu, E-mail: DJPisano@mail.wvu.edu, E-mail: jlockman@nrao.edu [National Radio Astronomy Observatory, Green Bank, WV 24944 (United States)

2016-01-10

Very sensitive 21 cm H i measurements have been made at several locations around the Local Group galaxy M31 using the Green Bank Telescope at an angular resolution of 9.′1, with a 5σ detection level of N{sub H} {sub i} = 3.9 × 10{sup 17} cm{sup −2} for a 30 km s{sup −1} line. Most of the H i in a 12 square-degree area almost equidistant between M31 and M33 is contained in nine discrete clouds that have a typical size of a few kpc and a H i mass of 10{sup 5}M{sub ⊙}. Their velocities in the Local Group Standard of Rest lie between −100 and +40 km s{sup −1}, comparable to the systemic velocities of M31 and M33. The clouds appear to be isolated kinematically and spatially from each other. The total H i mass of all nine clouds is 1.4 × 10{sup 6}M{sub ⊙} for an adopted distance of 800 kpc, with perhaps another 0.2 × 10{sup 6}M{sub ⊙} in smaller clouds or more diffuse emission. The H i mass of each cloud is typically three orders of magnitude less than the dynamical (virial) mass needed to bind the cloud gravitationally. Although they have the size and H i mass of dwarf galaxies, the clouds are unlikely to be part of the satellite system of the Local Group, as they lack stars. To the north of M31, sensitive H i measurements on a coarse grid find emission that may be associated with an extension of the M31 high-velocity cloud (HVC) population to projected distances of ∼100 kpc. An extension of the M31 HVC population at a similar distance to the southeast, toward M33, is not observed.

Density character of subgroups of topological groups

OpenAIRE

Leiderman, Arkady; Morris, Sidney A.; Tkachenko, Mikhail G.

2015-01-01

A subspace Y of a separable metrizable space X is separable, but without X metrizable this is not true even If Y is a closed linear subspace of a topological vector space X. K.H. Hofmann and S.A. Morris introduced the class of pro-Lie groups which consists of projective limits of finite-dimensional Lie groups and proved that it contains all compact groups, locally compact abelian groups and connected locally compact groups and is closed under products and closed subgroups. A topological group...

Center Director Bridges visits Disability Awareness and Action working Group Technology Fair

Science.gov (United States)

1999-01-01

Center Director Roy Bridges stops to pet one of the dogs that serves with Canine Companions for Independence, a vendor displaying its capabilities at the Disability Awareness and Action Working Group (DAAWG) 1999 Technology Fair being held Oct. 20-21 at Kennedy Space Center. Standing at the right is Carol Cavanaugh, with KSC Public Services; behind Bridges is Nancie Strott (left), a multi-media specialist with Dynacs and chairperson of the Fair, and Sterling Walker (right), director of Engineering Development and chairman of DAAWG. The Fair is highlighting vendors demonstrating mobility, hearing, vision and silent disability assistive technology. The purpose is to create an awareness of the types of technology currently available to assist people with various disabilities in the workplace. The theme is that of this year's National Disability Employment Awareness Month, 'Opening Doors to Ability.' Some of the other vendors participating are Goodwill Industries, Accessible Structures, Division of Blind Services, Space Coast Center for Independent Living, KSC Fitness Center and Delaware North Parks Services.

“Here is the knowledge-where should I put it?” Findings from a study of how knowledge spaces are used within a support group

DEFF Research Database (Denmark)

Carstensen, P. H.; Snis, U.

1999-01-01

In order to design useful knowledge media spaces for knowledge workers it is essential that we understand the nature of the work conducted and the knowledge applied in real settings. The paper reports from a study of how a group of quality assurance specialists in the pharmaceutical industry gather......, structure and distribute information and knowledge. Based on the findings, a number of overall requirements for knowledge media spaces are identified and discussed. The essential findings were that information and knowledge are created and handled in many different ways and have many different forms....... The core issues of our lessons learned so far are that we carefully need to consider knowledge media spaces both in terms of communication channels and knowledge archives. Knowledge media spaces should be seen as spaces in which knowledge and information is exchanged, filed, retrieved, presented...

Symmetry-adapted Liouville space. Pt. 7

International Nuclear Information System (INIS)

Temme, F.P.

1990-01-01

In examining nuclear spin dynamics of NMR spin clusters in density operator/generalized torque formalisms over vertical strokekqv>> operator bases of Liouville space, it is necessary to consider the symmetry mappings and carrier spaces under a specialized group for such (k i = 1) nuclear spin clusters. The SU2 X S n group provides the essential mappings and the form of H carrier space, which allows one to: (a) draw comparisons with Hilbert space duality, and (b) outline the form of the Coleman-Kotani genealogical hierarchy under induced S n -symmetry. (orig.)

Critical Dynamics of the Xy-Model on the One-Dimensional Superlattice by Position Space Renormalization Group

Science.gov (United States)

Lima, J. P. De; Gonçalves, L. L.

The critical dynamics of the isotropic XY-model on the one-dimensional superlattice is considered in the framework of the position space renormalization group theory. The decimation transformation is introduced by considering the equations of motion of the operators associated to the excitations of the system, and it corresponds to an extension of the procedure introduced by Stinchcombe and dos Santos (J. Phys. A18, L597 (1985)) for the homogeneous lattice. The dispersion relation is obtained exactly and the static and dynamic scaling forms are explicitly determined. The dynamic critical exponent is also obtained and it is shown that it is identical to the one of the XY-model on the homogeneous chain.

"Con Café, Compañerismo, y Calidad": Latina Women Fashioning a Writing Group into a Space of Praxis and Belonging

Science.gov (United States)

Hurtig, Janise

2016-01-01

This article explores the spatial practices through which a group of Mexican immigrant women, participants in a school-based writing workshop I facilitated for four years, molded and gave meaning to our weekly writing routine to foster inclusivity as the basis for collective teaching and learning--creating what I refer to as a space of praxis and…

Does defibrotide induce a delay to polymorphonuclear neutrophil engraftment after hematopoietic stem cell transplantation? Observation in a pediatric population.

Science.gov (United States)

Maximova, Natalia; Pizzol, Antonio; Giurici, Nagua; Granzotto, Marilena

2015-04-01

In recent years, defibrotide (DFT) has emerged as a promising therapy for veno-occlusive disease (VOD). The aim of this study was to investigate whether DFT prophylaxis affects neutrophil engraftment in patients undergoing hematopoietic stem cell transplantation (HSCT). A cohort of 44 consecutive pediatric patients who underwent HSCT was retrospectively analyzed to see the role of DFT on engraftment. Patients were assigned into two groups based on the use or non-use of prophylaxis with DFT. The mean time to engraftment was statistically different between the two groups for both polymorphonuclear neutrophils (PMN) and white blood cells. Our study supports the hypothesis that prophylaxis with DFT for VOD leads to a delay to the engraftment of PMN in pediatric patients that underwent HSCT.