A brief family and academic biography of Benson E. Ginsburg.
Maxson, Stephen C
2011-11-01
This is a brief personal biography of Benson E. Ginsburg, my friend, colleague and mentor. This is personal in several ways. First, it is about Benson's family as well as his career. Second, much of what I write is based on discussions with Benson. Third, after 1960, Benson's story is a big part of my story. I have been there for more than 50 years as it has unfolded.
Chiral correlators in Landau-Ginsburg theories and N=2 superconformal models
Howe, P.S.; West, P.C.
1989-01-01
Chiral correlation functions are computed in N=2 Landau-Ginsburg models using the ε-expansion and the superconformal Ward identities for the Landau-Ginsburg effective action. They are also computed directly using superconformal model techniques. The same results are obtained yielding further confirmation of the identification of superconformal minimal models with Landau-Ginsburg models evaluated at their fixed points. The formulae for the chiral commutators that we compute are extremely simple when expressed in terms of effective actions. (orig.)
Ginsburg-Landau equation around the superconductor-insulator transition
Ng, T.K.
1991-01-01
Based on the scaling theory of localization, we construct a Ginsburg-Landau (GL) equation for superconductors in an arbitrary strength of disordered potential. Using this GL equation, we reexamine the criteria for the superconductor-insulator transition and find that the transition to a localized superconductor can happen on both sides of the (normal) metal-insulator transition, in contrast to a previous prediction by Ma and Lee [Phys. Rev. B 32, 5658 (1985)] that the transition can only be on the insulator side. Furthermore, by comparing our theory with a recent scaling theory of dirty bosons by Fisher et al. [Phys. Rev. Lett. 64, 587 (1990)], we conclude that nontrivial crossover behavior in transport properties may occur in the vicinity of the superconductor-insulator transition
Non perturbative analysis of an N=2 Landau-Ginsburg model
Leaf Herrmann, W.A.
1993-01-01
We analyze the topological sector of an N=2 Landau-Ginsburg model using nonperturbative methods. In particular, we study the renormalization group flow between two superconformal minimal models, numerically compute the correlation functions along this trajectory, and compare the results to semi-classical calculations. We also study some aspects of arbitrary supersymmetric perturbations of the Landau-Ginsburg model. 20 refs, 4 figs
Boundary conditions in Ginsburg Landau theory and critical temperature of high-T superconductors
Lykov, A. N.
2008-06-01
New mixed boundary conditions to the Ginsburg-Landau equations are found to limit the critical temperature ( T) of high- T superconductors. Moreover, the value of the pseudogap in these superconductors can be explained by using the method. As a result, the macroscopic approach is proposed to increase T of cuprate superconductors.
N=2 superconformal models, Landau-Ginsburg Hamiltonians and the ε expansion
Howe, P.S.; West, P.C.
1989-01-01
The anomalous dimensions of a class of operators, operator product expansions and the central change, c, are calculated in a family of N=2 supersymmetric two-dimensional Landau-Ginsburg models. The results allow the identification of these theories with N=2 minimal superconformal models. A key role is placed by the N=2 non-renormalization theorem. (orig.)
Ginsburg criterion for an equilibrium superradiant model in the dynamic approach
Trache, M.
1991-10-01
Some critical properties of an equilibrium superradiant model are discussed, taking into account the quantum fluctuations of the field variables. The critical region is calculated using the Ginsburg criterion, underlining the role of the atomic concentration as a control parameter of the phase transition. (author). 16 refs, 1 fig
Boundary conditions in Ginsburg-Landau theory and critical temperature of high-Tc superconductors
Lykov, A.N.
2008-01-01
New mixed boundary conditions to the Ginsburg-Landau equations are found to limit the critical temperature (T c ) of high-T c superconductors. Moreover, the value of the pseudogap in these superconductors can be explained by using the method. As a result, the macroscopic approach is proposed to increase T c of cuprate superconductors
Landau-Ginsburg models with N=2 supersymmetry as conventional conformal theories
Marshakov, A.
1990-01-01
The conformal Landau-Ginsburg (LG) models are identified with the Toda-like two-dimensional field theories. At least in the N=2 supersymmetric case they possess a simple free-field representation, related to the Nicolai map. (orig.)
Morales, J.
1989-08-01
Full Text Available In 1980, Ginsburg created the new genus Xenobyus for a large suiform artiodactyl which he considered to belong to the family Suidae. Among the distinguishing characters of the genus, Ginsburg cited the enlarged, strongly curved and inflated central upper incisors possessing a distal accessory cusplet, the shortened muzzle, the enlarged lower first and second incisors, and the c10se packing of the entire tooth row (i.e. reduced to absent diastemata. These and other characters, such as the vertically implanted mandibular canines, the sympbyseal morphology, and the shape of the third upper incisor, suggest that Xenobyus belongs instead to the family Tayassuidae, subfamily Doliochoerinae. Whereas Ginsburg suggested that Xenobyus had an unknown ancestry and that it represented an immigrant into Europe at about the beginning of zone MN2b, it now seems more likely that it represents a late doliochoere of the sort represented by Doliochoerus quercyi which occurs in late Stampian deposits (Ginsburg, 1974. In many ways it is merely an enlarged version of this species, but there are sufficient morphological differences to warrant retention of the genus Xenobyus. Viewed within a tayassuid framework, Xenobyus is not seen to be unusual and not to run counter to evolutionary trends in the Suidae, the latter view being a necessity following its identifiation as a suid. Sorne fundamental similarities between tbe molars of Xenobyus and Kenyapotamus could provide a link between late doliochoeres and early hippopotamids, an hypothesis already mentioned by Pickford (1983. Newly discovered fossils from Loranca, Cuenca, Spain belong to two different species of Xenobyus, X venitor and an undescribed larger species. Nuevos fósiles, descubiertos en Loranca (Cuenca, España, pertenecientes a dos diferentes especies de Xenobyus; X vemtor y Xenobyus sp. de talla mayor que el anterior, son también descritos en este trabajo.Ginsburg (1980 creó un nuevo género Xenobyus
Solutions without phase-slip for the Ginsburg-Landau equation
Collet, P.; Eckmann, J.P.
1992-01-01
We consider the Ginsburg-Landau equation for a complex scalar field in one dimension and consider initial data which have two different stationary solutions as their limits in space as x→±∞. If these solutions are not very different, then we show that the initial data will evolve to a stationary solution by a 'phase melting' process which avoids 'phase slips,' i.e., which does not go through zero amplitude. (orig.)
Modeling of superconductors based on the timedependent Ginsburg-Landau equations
Grishakov, K. S.; Degtyarenko, P. N.; Degtyarenko, N. N.; Elesin, V. F.; Kruglov, V. S.
2009-11-01
Results of modeling of superconductor magnetization process based on a numerical solution of the timedependent Ginsburg-Landau equations are presented. Methods of grid approximation of the equations and method of finite elements are used. Two-dimensional patterns of changes in the order parameter and supercurrent distribution in superconductors are calculated and visualized. The main results are in agreement with the well-known representations for type I and II superconductors.
Léonard Ginsburg et la Paléontologie Portugaise. Hommage amical
Telles Antunes, M.
2011-12-01
Full Text Available Léonard Ginsburg has been a distinguished palaeontologist. He was a gifted one: intelligence, high working capacity, experience, knowledge and critical sense. As critical sense is not always the best for some people, adversaries were not rare. He was both an accomplished researcher and a deep connoisseur of the collections under his responsibility, as well as someone with a broad knowledge of the science world. By the high number and value of his contributions, an homage that he deserved so much is but an act of justice. As far as I am concerned, Ginsburg was a Colleague and Friend since 1961 until the end, even after his research activities ceased. Of course, his contributions cannot be valued just from a personal viewpoint. We can recognize their value for, among many others, a Country as Portugal. After obtaining a scholarship to prepare my Ph.D., I drove to Paris loaded with vertebrate fossils from Angola and Portugal, not without a few incidents because, by sheer chance, I arrived just the day of the Algerian “putsch”. Here they are my beginnings in Paris that developed into an institutional and personal collaboration and friendship for half a century. I have been very well received by the Director of the Muséum’s Institut de Paléontologie, Professor Jean-Pierre Lehman. I was lodged at the building’s basement. Soon afterwards, an unknown man approached asking me if I was a young « Spaniard » that came in to study fossil vertebrates, as Mr. Lehman had told him. He was Léonard Ginsburg. Our collaboration begun. We dealt mainly with the Miocene mammalian faunas from Portugal, and especially from Lisbon, as well as some Eocene ones. Nevertheless we also studied some other groups as crocodilians and areas, mostly in France. Research was carried on at the Paris Museum, the concerned Portuguese institutions and on the field. Under a palaeontological viewpoint, a most important place concerns Carnivora and Rhinocerotidae, as well as
Ginsburg-Landau theory of two antagonistic order parameters: magnetism and superconductivity
Suhl, H.
1978-01-01
An attempt is made to construct a Ginsburg-Landau theory of so-called magnetic superconductors. Two order parameters, the magnetization field and the gap function, are introduced in such a way as to inhibit each others growth. It is found that the non-local character of the superconducting order parameter must be taken into account in any evaluation of effects of the critical magnetic fluctuations. Some predictions are made within the limits of Ornstein-Zoernicke-like fluctuation theory and some comparison is made with available data. (Auth.)
Hamiltonian formalism of Whitham-type hierarchies and topological Landau-Ginsburg models
Dubrovin, B.A.
1992-01-01
We show that the bi-hamiltonian structure of the averaged Gelfand-Dikii hierarchy is involved in the Landau-Ginsburg topological models (for A n -Series): The Casimirs for the first P.B. give the correct coupling parameters for the perturbed topological minimal model; the correspondence {coupling parameters}→{primary fields} is determined by the second P.B. The partition function (at the tree level) and the chiral algebra for LG minimal models are calculated for any genus g. (orig.)
Morales, J.
2011-12-01
Full Text Available Several dental remains from the Early Miocene of Estrepouy (MN3, France previously reported as Amphitragulus aurelianensis by Roman & Viret (1934 are described in this work and assigned to Andegameryx andegaviensis Ginsburg, 1971. The re-study of this material and the comparison with other remains of A. andegaviensis from several european localities of the early Miocene, including the type locality of the species, have permitted us to confirm the presence of A. andegaviensis in the ruminant fauna from Estrepouy.En esta nota describimos algunos de los restos del yacimiento del Mioceno inferior de Estrepouy (MN3, Francia atribuidos por Roman & Viret (1934 a Amphitragulus aruelianensis, cambiando su asignación a Andegameryx andegaviensis Ginsburg, 1971. El reestudio del material y su comparación con los restos de A. andegaviensis de otras localidades europeas del Mioceno inferior, incluyendo la localidad tipo de la especie, permiten confirmar su presencia entre la fauna de rumiantes fósiles de Estrepouy.
Rosana Beatriz Silveira
2000-06-01
Full Text Available The sequence of events of the ossification process in the newly bom specimens of Hippocampus reidi Ginsburg, 1933 up to 37 days of life has been described, mainly the ossification in the ethmoid plate, palatine, pectoral girdle, and postorbital bones and bony structures such as mesoethmoid, articular and six suborbitals. Observation on adult specimens are presented too.
Renormalization group equations and the Lifshitz point in noncommutative Landau-Ginsburg theory
Chen, G.-H.; Wu, Y.-S.
2002-01-01
A one-loop renormalization group (RG) analysis is performed for noncommutative Landau-Ginsburg theory in an arbitrary dimension. We adopt a modern version of the Wilsonian RG approach, in which a shell integration in momentum space bypasses the potential IR singularities due to UV-IR mixing. The momentum-dependent trigonometric factors in interaction vertices, characteristic of noncommutative geometry, are marginal under RG transformations, and their marginality is preserved at one loop. A negative Θ-dependent anomalous dimension is discovered as a novel effect of the UV-IR mixing. We also found a noncommutative Wilson-Fisher (NCWF) fixed point in less than four dimensions. At large noncommutativity, a momentum space instability is induced by quantum fluctuations, and a consequential first-order phase transition is identified together with a Lifshitz point in the phase diagram. In the vicinity of the Lifshitz point, we introduce two critical exponents ν m and β k , whose values are determined to be 1/4 and 1/2, respectively, at mean-field level
Hansen, Nienke; Patruno, Giulio; Wadhwa, Karan; Gaziev, Gabriele; Miano, Roberto; Barrett, Tristan; Gnanapragasam, Vincent; Doble, Andrew; Warren, Anne; Bratt, Ola; Kastner, Christof
2016-08-01
Prostate biopsy supported by transperineal image fusion has recently been developed as a new method to the improve accuracy of prostate cancer detection. To describe the Ginsburg protocol for transperineal prostate biopsy supported by multiparametric magnetic resonance imaging (mpMRI) and transrectal ultrasound (TRUS) image fusion, provide learning points for its application, and report biopsy results. The article is supplemented by a Surgery in Motion video. This single-centre retrospective outcome study included 534 patients from March 2012 to October 2015. A total of 107 had no previous prostate biopsy, 295 had benign TRUS-guided biopsies, and 159 were on active surveillance for low-risk cancer. A Likert scale reported mpMRI for suspicion of cancer from 1 (no suspicion) to 5 (cancer highly likely). Transperineal biopsies were obtained under general anaesthesia using BiopSee fusion software (Medcom, Darmstadt, Germany). All patients had systematic biopsies, two cores from each of 12 anatomic sectors. Likert 3-5 lesions were targeted with a further two cores per lesion. Any cancer and Gleason score 7-10 cancer on biopsy were noted. Descriptive statistics and positive predictive values (PPVs) and negative predictive values (NPVs) were calculated. The detection rate of Gleason score 7-10 cancer was similar across clinical groups. Likert scale 3-5 MRI lesions were reported in 378 (71%) of the patients. Cancer was detected in 249 (66%) and Gleason score 7-10 cancer was noted in 157 (42%) of these patients. PPV for detecting 7-10 cancer was 0.15 for Likert score 3, 0.43 for score 4, and 0.63 for score 5. NPV of Likert 1-2 findings was 0.87 for Gleason score 7-10 and 0.97 for Gleason score ≥4+3=7 cancer. Limitations include lack of data on complications. Transperineal prostate biopsy supported by MRI/TRUS image fusion using the Ginsburg protocol yielded high detection rates of Gleason score 7-10 cancer. Because the NPV for excluding Gleason score 7-10 cancer was very
Rosana Beatriz Silveira
2000-06-01
Full Text Available The cartilaginous Structures of the cmbryos of Hippocampus reidi Ginsburg, 1933, were described as well as the beginning of the ossification process in the dentary, angular, retroarticular, operculum, frontal, supraoccipital bonés and neural end hemal arches. The viteline sac is well developed. The results show that cartilaginous structures are predominam in specimens with an average of 4.85 mm in total length.
Lin, Shan; Lü, Tianquan; Jin, Changqing; Wang, Xiaohui
2006-10-01
Grain size effects on the dielectric properties of BaTiO3 nanoceramics have been studied by using the modified Ginsburg-Landau-Devonshire (GLD) thermodynamic theory. Considering the existence of internal stresses, it is found that with decreasing grain size the transition temperature of cubic-tetragonal phase decreases, while those of tetragonal-orthorhombic and orthorhombic-rhombohedral phases increase. With further reducing grain size, our model predicts that the two ferroelectric structures of orthorhombic and tetragonal phases will become unstable and disappear at a critical size, leaving only one stable ferroelectric phase of rhombohedral structure. Consequently, a theoretical phase diagram of the transition temperature versus grain size is established wherein two triple points and a reentrance behavior are indicated. The results are compared with experimental data.
Bhattarai, Susma; Cassarini, Chiara; Rene, Eldon R; Zhang, Yu; Esposito, Giovanni; Lens, Piet N L
2018-07-01
This study was performed to enrich anaerobic methane-oxidizing archaea (ANME) present in sediment from the Ginsburg Mud Volcano (Gulf of Cadiz) in a polyurethane foam packed biotrickling filter (BTF). The BTF was operated at 20 (±2) °C, ambient pressure with continuous supply of methane for 248 days. Sulfate reduction with simultaneous sulfide production (accumulating ∼7 mM) after 200 days of BTF operation evidenced anaerobic oxidation of methane (AOM) coupled to sulfate reduction. High-throughput sequence analysis of 16S rRNA genes showed that after 248 days of BTF operation, the ANME clades enriched to more than 50% of the archaeal sequences, including ANME-1b (40.3%) and ANME-2 (10.0%). Enrichment of the AOM community was beneficial to Desulfobacteraceae, which increased from 0.2% to 1.8%. Both the inoculum and the BTF enrichment contained large populations of anaerobic sulfur oxidizing bacteria, suggesting extensive sulfur cycling in the BTF. Copyright © 2018 Elsevier Ltd. All rights reserved.
Toyos, María H.; Medialdea, Teresa; León, Ricardo; Somoza, Luis; González, Francisco Javier; Meléndez, Nieves
2016-06-01
High-resolution single channel and multichannel seismic reflection profiles and multibeam bathymetric and backscatter data collected during several cruises over the period 1999 to 2007 have enabled characterising not only the seabed morphology but also the subsurface structural elements of the Yuma, Ginsburg, Jesús Baraza and Tasyo mud volcanoes (MVs) in the Gulf of Cádiz at 1,050-1,250 m water depth. These MVs vary strongly in morphology and size. The data reveal elongated cone-shaped edifices, rimmed depressions, and scarps interpreted as flank failures developed by collapse, faulting, compaction and gravitational processes. MV architecture is characterised by both extrusive and intrusive complexes, comprising stacked edifices (including seabed cones and up to four buried bicones) underlain by chaotic vertical zones and downward-tapering cones suggesting feeder systems. These intrusive structures represent the upper layer of the feeder system linking the fluid mud sources with the constructional edifices. The overall architecture is interpreted to be the result of successive events of mud extrusion and outbuilding alternating with periods of dormancy. Each mud extrusion phase is connected with the development of an edifice, represented by a seabed cone or a buried bicone. In all four MVs, the stacked edifices and the intrusive complexes penetrate Late Miocene-Quaternary units and are rooted in the Gulf of Cádiz wedge emplaced during the late Tortonian. Major phases of mud extrusion and outbuilding took place since the Late Pliocene, even though in the Yuma and Jesús Baraza MVs mud volcanism started in the Late Miocene shortly after the emplacement of the Gulf of Cádiz wedge. This study shows that fluid venting in the eastern sector of the Gulf of Cádiz promoted the outbuilding of large long-lived mud volcanoes active since the Late Miocene, and which have been reactivated repeatedly until recent times.
Field studies of a Brazilian seahorse population, Hippocampus reidi Ginsburg, 1933
Natalie Villar Freret-Meurer
2008-08-01
Full Text Available This study was carried out to fill the gaps that remain under Hippocampus reidi biology. Analysis of variations of sex ratio, density, breeding season, distribution and home range of a population of the endangered Brazilian seahorse H. reidi from a rocky shore on Araçatiba beach, Ilha Grande, Brazil were carried out. Araçatiba beach is a tourist Environmental Protected Area, suffering antropic pressure. A fixed population of H. reidi was studied, where al lthe individuals were visually tagged and sex, reproductive state and location on site were identified from December 2002 to November 2004. A total of 20 individuals were visually tagged with a mean density of 0.18 m-2. Sex ratios were skewed, with more females than males. All the males brooded during 13 months and presented smaller home range than the females during the breeding season. The highest densities were found on shallowest areas.Este estudo foi realizado com o objetivo de preencher algumas lacunas sobre a biologia natural de Hippocampus reidi. Foram analisadas as variações na proporção sexual e densidade, período reprodutivo, distribuição e área de deslocamento de uma população do cavalo marinho brasileiro ameaçado de extinção Hippocampus reidi de um costão rochoso da praia de Araçatiba, Ilha Grande, Brasil. A praia de Araçatiba é uma Área de Proteção Ambiental turística, a qual sofre com a pressão antropogênica. Foi estudada uma população fixa de H. reidi, sendo que todos os indivíduos foram marcados visualmente e foram determinados o sexo, o período reprodutivo e a localização na área de novembro de 2002 a novembro de 2004. Um total de 20 indivíduos foram marcados com uma densidade média na área de 0,18 m-2. A proporção sexual variou de forma alternada com maior número de fêmeas que de machos. Durante 13 meses todos os machos encontrados estavam incubando. Os cavalos marinhos apresentaram área de deslocamento menor que as fêmeas durante o período reprodutivo. As maiores densidades foram encontradas em áreas mais rasas da área de estudo.
Novel sex-related characteristics of the longsnout seahorse Hippocampus reidi Ginsburg, 1933
Tacyana P. R Oliveira
Full Text Available This paper presents novel sex-related characteristics in Hippocampus reidi, expressed as a prominent and pigmented keel (males only, and by a row of dorsolateral spots mostly (97.4% found in males. While the keel was found even in the smallest males sampled, the dorsolateral spots appear to be associated with body size. Ex situ observations revealed that during courtship males highlighted both characters by turning pale their background body colour. Understanding such colour and behavioural patterns is relevant to increase our knowledge about sexual selection in a morphologically and biologically unique group of fishes.
Wang, Xin; Zhang, Yanhong; Zhang, Huixian; Meng, Tan; Lin, Qiang
2016-01-01
The complete mitochondrial genome sequence of the longsnout seahorse Hippocampus reidi was fisrt determined in this article. The total length of H. reidi mitogenome is 16,529 bp and consists of 13 protein-coding genes, 2 rRNA genes, 22 tRNA genes and 1 control region. The gene order and composition of H. reidi were similar to those of most other vertebrates. The overall base composition of H. reidi is 32.47% A, 29.41% T, 14.75% G and 23.37% C, with a slight A + T rich feature (61.88%).
VizieR Online Data Catalog: Central Molecular Zone H2O temperature maps (Ginsburg+, 2016)
Ginsburg, A.; Henkel, C.; Ao, Y.; Riquelme, D.; Kauffmann, J.; Pillai, T.; Mills, E. A. C.; Requena-Torres, M. A.; Immer, K.; Testi, L.; Ott, J.; Bally, J.; Battersby, C.; Darling, J.; Aalto, S.; Stanke, T.; Kendrew, S.; Kruijssen, J. M. D.; Longmore, S.; Dale, J.; Guesten, R.; Menten, K. M.
2015-08-01
We observed the Central Molecular Zone from -0.4°
Analytic solutions to a family of boundary-value problems for Ginsburg-Landau type equations
Vassilev, V. M.; Dantchev, D. M.; Djondjorov, P. A.
2017-10-01
We consider a two-parameter family of nonlinear ordinary differential equations describing the behavior of a critical thermodynamic system, e.g., a binary liquid mixture, of film geometry within the framework of the Ginzburg-Landau theory by means of the order-parameter. We focus on the case in which the confining surfaces are strongly adsorbing but prefer different components of the mixture, i.e., the order-parameter tends to infinity at one of the boundaries and to minus infinity at the other one. We assume that the boundaries of the system are positioned at a finite distance from each other and give analytic solutions to the corresponding boundary-value problems in terms of Weierstrass and Jacobi elliptic functions.
VizieR Online Data Catalog: JVLA images of W51A (Ginsburg+, 2016)
Ginsburg, A.; Goss, W. M.; Goddi, C.; Galvan-Madrid, R.; Dale, J.; Bally, J.; Battersby, C.; Youngblood, A.; Sankrit, R.; Smith, R.; Darling, J.; Kruijssen, J. M. D.; Liu, H.-Y. B.
2016-07-01
We used the Karl G. Jansky Very Large Array (JVLA) in multiple bands and configurations. In project 12B-365, we observed in A-array in S and C bands (3 and 5GHz, approximately) with 2GHz total bandwidth. In project 13A-064, we observed in C-band in C (1h) and A (5h) arrays and in Ku-band in D (1h) and B (5h) arrays. We also include continuum data from project 12A-274 (Goddi et al., 2015A&A...573A.109G, 2016, Cat. J/A+A/589/A44) covering the range 25-36GHz using the JVLA B array configuration. Our spectral coverage included o-H2CO 11,01-1,1_ at 4.82966GHz and 21,1-21,2 at 14.488GHz with 0.3km/s resolution and the radio recombination lines (RRLs) H77α (14.1286GHz) and H110α (4.8741GHz) at 1km/s resolution. The H110α line had lower S/N than the H77α line but was otherwise similar; it is not discussed further in this paper. (3 data files).
Matveev, S. K.; Arkhangelskaya, L. A.; Akimov, G. A.
2018-05-01
Isaak Pavlovich Ginzburg (1910-1979) was a professor at the hydroaeromechanics department of Leningrad State University, a prominent scientist, an outstanding organizer and a brilliant educator, who had trained more than one generation of specialists in the field of fluid, gas and plasma mechanics. Many of his students became major scientists and organizers of science. The present paper is devoted to the students of I.P. Ginzburg graduated from the Mathematics and Mechanics Faculty of Leningrad State University.
Viviane Martins de Oliveira
2012-06-01
Full Text Available Seahorses are found all over the world, in tropical and temperate coastal waters. The main aim of this study was to characterize the Hippocampus reidi populations in different depth and hydrodynamism categories in Arraial do Cabo, Rio de Janeiro state. The study was developed through scuba diving, with transects of 20m x 5m in two different depth layers: shallow, between 0 and 5m, and deep, between 5 and 10m. Through visual surveys, individuals were identified according to species, sex, and size (height – HT. The density of H. reidi varied according to depth and hydrodynamism. The highest mean depth was found in the Cabo Frio Island – Ponta do Anequin, as the lowest depth was found in Praia do Forno – Ponta D’água. There is no significant difference in the size of individuals nor in the sex ratio between the depth categories. The sex ratio of H. reidi in the population of Arraial do Cabo was 1:1. The results obtained indicated that the population characteristics are similar between the two depth layers.
Otero-Ferrer, Francisco; Izquierdo, Marisol; Fazeli, Alireza; Holt, William V
2016-06-01
The aim of the present study was to investigate the hypothesis that parental periconception nutrition in adult seahorses affects the development and growth of their offspring. We tested the hypothesis that because seahorse embryos develop inside the male's brood pouch, manipulation of the male's diet would affect offspring growth and development independently of the female's diet. Adult males and females were fed separately with either wild-caught crustaceans or commercial aquarium diet for 1 month before conception to influence the periconception environment. Approximately 10000 offspring were obtained from four different treatment groups (Male/Wild or Male/Commercial×Female/Wild or Female/Commercial). Weights, physical dimensions and fatty acid profiles of the newborns were determined. Offspring produced when the males receiving commercial diet were mated with wild-fed females were larger (P<0.05) than those produced by wild-fed males. When both males and females were fed with commercial diet, their offspring were significantly smaller than those from the other treatment groups. When commercial diet-fed females were mated with wild-fed males, the offspring showed distortion of the snout:head length ratio. These results support the view that the preconception diet received by males and females differentially affects embryonic development.
ML. Martins
Full Text Available The aim of this study was to evaluate the pathogenicity of Vibrio alginolyticus isolated from an outbreak of sea horse Hippocampus reidi reared in the State of Santa Catarina, Brazil, by experimental infection. Sea horses with necrosis on the mouth epithelium were collected from aquaria at the Aquaculture Department, UFSC and the bacterium isolated from the mouth, liver, heart and blood in tiosulphate citrate bilesalt sucrose agar broth. The strains were identified by API 20E kit with 99.1% probability as Vibrio alginolyticus. Twelve adult sea horses (9.63 ± 2.42 g and 15.12 ± 0.87 cm were distributed in six aquaria of 10 L capacity with aerated sea water. Fish from three aquaria were submitted to an immersion bath in a solution containing 1.0 × 10(7 CFU of V. alginolyticus/mL for 15 minutes. Fish from the other three aquaria received the same procedure without bacteria. Twenty four hours after this challenge, 100% mortality was observed in the animals infected with V. alginolyticus. No mortality was observed in non-infected fish. Hyperplasia, displacement and fusion of secondary lamellae of the gills; leukocyte infiltration and necrotic foci in the kidney; hyperplasia, sinusoidal deformation and necrotic foci in the liver were observed in histopathological analysis. The V. alginolyticus isolated in this study was pathogenic to H. reidi and constitutes an important sanitary problem to its culture.
Bliss, Stacy
2006-01-01
The Test of Early Mathematics Ability--Third Edition (TEMA-3) is a norm-referenced parallel forms test intended to identify the level of mathematical ability for children aged 3 years 0 months through 8 years 11 months. According to the authors, the instrument can also be used as a criterion referenced or diagnostic tool for older students who are…
Lassen, Hans; Barriga Rivera, Edward; Palacios León, Jacqueline; Vargas López, Nathaly; Díaz Acuña, Erich; Argüelles Torres, Juan
2009-01-01
Análisis del estado del stock de la merluza peruana, mediante un análisis de población virtual, haciendo uso de la información disponible en la Unidad de Investigaciones en Peces Demersales, Bentónicos y Litorales (UIPDBL) del Instituto del Mar del Perú (IMARPE), actualizada y revisada a partir de la información empleada en los paneles de expertos precedentes (2003 y 2004). Boletín IMARPE vol. 24 nº 1-2, 2009; p. 21-26
Natalie Freret-Meurer
2012-02-01
Full Text Available http://dx.doi.org/10.5007/2175-7925.2012v25n2p59 Os cavalos-marinhos são encontrados em todo o mundo, em águas rasas da costa tropical e temperada. Este trabalho tem como objetivo caracterizar as populações de cavalos-marinhos em diferentes gradientes de profundidade e hidrodinamismo. O estudo foi realizado em seis áreas selecionadas aleatoriamente em Arraial do Cabo, Rio de Janeiro. O estudo foi desenvolvido com mergulho autônomo. Foram realizadas transecções de 20m x 5m em dois estratos de profundidade: acima de cinco metros de profundidade (0 - 5m e abaixo de cinco metros (5 – 10m. Utilizando censo visual, os exemplares foram identificados quanto à espécie, ao sexo e biometrados (height – HT. De acordo com os resultados, a densidade do cavalo-marinho variou com a profundidade e o hidrodinamismo do local. A maior profundidade média foi encontrada na Ilha de Cabo Frio – Ponta do Anequin, já a menor foi na Praia do Forno – Ponta D’água. Não há diferença significativa no tamanho dos indivíduos acima e abaixo dos 5m. A profundidade de machos e fêmeas também não apresentou variações significativas. A razão sexual de H. reidi na população de Arraial do Cabo é de 1:1. Os resultados obtidos indicaram que as características populacionais são semelhantes entre os dois estratos de profundidade.
Time Well Spent: Making Choices and Setting Priorities in Adult Numeracy Instruction
Braaten, Melissa
2017-01-01
In her Forum piece, "What's an Adult Numeracy Teacher to Teach? Negotiating the Complexity of Adult Numeracy Instruction," Lynda Ginsburg set the stage of the current problem (poor numeracy levels in American adults) and the bevy of standards, legislation, and new exams that have recently been developed to address it. Ginsburg also…
An Algebraic Approach to Incomparable Families of Formal Languages
Rozenberg, G.; Asveld, P.R.J.; Salomaa, A.
1993-01-01
We extend some results of Ginsburg and Spanier [S. Ginsburg & E.H. Spanier, On incomparable Abstract Families of Languages (AFL), J. Comput. Systems Sci. 9 (1974) 88-108] on incomparable full AFL's (full Abstract Families of Languages) to similar structures like full hyper-AFL's, full hyper(1)-AFL's
The Case against Michelle Rhee: How Persuasive Is It?
Peterson, Paul E.
2011-01-01
Recently, two separate studies--one by Alan Ginsburg, a former director of Policy and Program Studies in the U.S. Department of Education, the other by a committee constituted by the National Research Council (NRC)--have sought to discredit the work of Michelle Rhee, former chancellor of schools for the District of Columbia. According to Ginsburg,…
An Algebraic Approach to Incomparable Families of Formal Languages
Asveld, P.R.J.; Rozenberg, G.; Salomaa, A.
1992-01-01
We extend some results of Ginsburg and Spanier [S. Ginsburg & E.H. Spanier, On incomparable Abstract Families of Languages (AFL), J. Comput. Systems Sci. 9 (1974) 88-108] on incomparable full AFL's (full Abstract Families of Languages) to similar structures like full hyper-AFL's, full hyper(1)-AFL's
Young Children's Mathematics References during Free Play in Family Childcare Settings
Hendershot, Shawnee M.; Berghout Austin, Ann M.; Blevins-Knabe, Belinda; Ota, Carrie
2016-01-01
Very little is known about children's discussion of mathematics topics during unstructured play. Ginsburg, Lin, Ness, and Seo [2003. Young American and Chinese children's everyday mathematical activity. Mathematical Thinking and Learning, 5(4), 235-258. Retrieved from…
Gauge groups and topological invariants of vacuum manifolds
Golo, V.L.; Monastyrsky, M.I.
1978-01-01
The paper is concerned with topological properties of the vacuum manifolds in the theories with the broken gauge symmetry for the groups of the type SO(k) x U(n), SO(k) x SO(p) x U(r). For the Ginsburg-Landau theory of the superfluid 3 He the gauge transformations are discussed. They provide the means to indicate all possible types of the vacuum manifolds, which are likely to correspond to distinct phases of the superfluid 3 He. Conditions on the existence of the minimums of the Ginsburg-Landau functional are discussed
Oliveira, I.G. de.
1994-04-01
Using the London theory, a correction is obtained between the direction of the magnetic induction B and the applied magnetic field H in superconductors with uniaxial anisotropy when the Ginsburg-Landau constant is not so large. One analysis of the magnetization as function of angle α is made. (author). 5 refs, 2 figs
Oliveira, I.G. de
1994-04-01
Using the London theory, a correction is obtained between the direction of the magnetic induction B and the applied magnetic field H in superconductors with uniaxial anisotropy when the Ginsburg-Landau constant is not so large. One analysis of the magnetization as function of angle {alpha} is made. (author). 5 refs, 2 figs.
The Global Positioning System--Direction for the Future [and] GPS Technology and Agriculture.
Edmondson, Paul R.; Ginsburg, Alan
1996-01-01
Edmondson introduces a satellite-based radio navigation, positioning, and timing system that can be integrated into a variety of curriculum areas. Ginsburg describes how the global positioning system brings far-reaching benefits for crop growers and the environment. (Author)
Extensions of Families of Languages: Lattices of Full X-AFL's
Asveld, P.R.J.
1976-01-01
This paper is a continuation of our research on $X$-extensions and full $X$-AFL's. We discuss the algebraic structure of the class of all full $X$-AFL's and establish a Canonical Form Theorem for full $X$-AFL's (similar to a theorem for full AFL's obtained earlier by Ginsburg & Spanier (1971)) i.e.
The Development of Contour Interpolation: Evidence from Subjective Contours
Hadad, Bat-Sheva; Maurer, Daphne; Lewis, Terri L.
2010-01-01
Adults are skilled at perceiving subjective contours in regions without any local image information (e.g., [Ginsburg, 1975] and [Kanizsa, 1976]). Here we examined the development of this skill and the effect thereon of the support ratio (i.e., the ratio of the physically specified contours to the total contour length). Children (6-, 9-, and…
Departures from predicted type II behavior in dirty strong-coupling superconductors
Park, J.C.; Neighbor, J.E.; Shiffman, C.A.
1976-01-01
Calorimetric measurements of the Ginsburg-Landau parameters for Pb-Sn and Pb-Bi alloys show good agreement with the calculations of Rainer and Bergmann for kappa 1 (t)/kappa 1 (1). However, the calculations of Rainer and Usadel for kappa 2 (t)/kappa 2 (1) substantially underestimate the enhancements due to strong-coupling. (Auth.)
Mean-field theory for the Tsub(c2)-minimum in the phase diagram of Ersub(1-x)Hosub(x)Rh4B4
Schuh, B.; Grewe, N.
1981-01-01
The experimentally observed shape of the phase boundary between the superconducting and the ferromagnetically ordered state in the reentrant ferromagnetic superconductor compound Ersub(1-x)Hosub(x)Rh 4 B 4 is explained within a simple Ginsburg-Landau mean field theory as resulting from a competition of two order parameters corresponding to the magnetic Ho- and Er-moments respectively. (author)
Dr Olaleye
(200ppm). After 24hr fast, gastric acid secretion was measured using the continuous perfusion method of. Ghosh and Schild (1958), modified by Amure and. Ginsburg (1964). Animals where anaesthetized with pentobarbital (35 mg/kg i.p) and a midline laparotomy was made to expose the stomach and duodenum. A semi-.
Evaluation of a commercial Streptococcus pyogenes in a kit for ...
1990-07-03
Jul 3, 1990 ... 4. Cruickshank R, Duguid JP, Marmion BP, Swain RHA, Medical Microbiology. 12th ed. Edinburgh: Churchill Livingsrone, 1975: 367-372. 5. Ginsburg PJ. A ceview of bum-wound infections in 1986 with a critical . analysis of diagnostic methods, rreatment and prophylaxis at Hillbrow. Hospital. M. Med. (path.
On the theory of type-I superconductor surface tension and twinning-plane-superconductivity
Mishonov, T.M.
1990-01-01
A correction is found to the surface tension in type-I superconductors which is proportional to the square root of the Ginsburg-Landau parameter. This correction is essential for obtaining the phase diagram and other thermodynamical variables of the narrow superconducting layer arising near the twinning plane in some metals
Theories of Career Development. Fourth Edition.
Osipow, Samuel H.; Fitzgerald, Louise F.
This book describes and assesses the major theories of career choice and related research. The following are among the topics examined: history of vocational and career psychology (historical foundations; psychoanalytic conceptions of career choice; the Ginzberg, Ginsburg, Axelrad, and Herma theory; Tiedeman's developmental theory; recent history…
Heng, Mary Anne; Sudarshan, Akhila
2013-01-01
This paper examines the perceptions and understandings of ten grades 1 and 2 Singapore mathematics teachers as they learned to use clinical interviews (Ginsburg, "Human Development" 52:109-128, 2009) to understand students' mathematical thinking. This study challenged teachers' pedagogical assumptions about what it means to teach for…
Always Searching for Strengths: Interviewing and Counseling with the Circle of Courage
Frankowski, Barbara; Duncan, Paula
2013-01-01
Several excellent frameworks exist that define components of positive youth development and demonstrate an inverse relationship with adolescent risks (Ginsburg, 2007). The authors have found that many of their colleagues have been drawn to the Circle of Courage for its clarity and spirit (Brendtro, Brokenleg, & Van Bockern, 2002). This model is…
Genetic diversity of Plasmodium falciparum field isolates
Administrator
Bourdy M, Willcox L, Ginsburg H, Rasoanaivo. P, Graz B, and Deharo E. Ethnopharmacology and malaria: New hypothetical leads or old efficient antimalarials? International Journal for. Parasitology. 2008; 38: 33–41. 5. Basco LK, Tahar R, Escalante A. Molecular epidemiology of malaria in Cameroon. Xviii. Polymorphisms ...
Dyayiya et al., Afr J Tradit Complement Altern Med. (2016) 13(1):114 ...
PROF ADEWUNMI
University, Mthatha, Republic of South Africa, 2Department of Pharmacology, Faculty of Pharmacy, Obafemi Awolowo. University, Ile-Ife, Osun State, Nigeria, 31124 Buchanan Street, Ginsburg, King Williams Town, Eastern Cape, South. Africa, 4Department of Chemistry, Faculty of Science & Agriculture, University of Fort ...
Rheumatic fever prophylaxis in South Africa - is bicillin 1,2 million ...
1993-09-30
Sep 30, 1993 ... inducing loss of the organism's hyaluronic acid capsule and. M-proteins'6.21 Rheumatogenic strains of GABHS tend to· be highly virulent."·'6 It is therefore possible that serum penicillin concentrations below the MBCs for GABHS might be effective in secondary prophylaxis of rheumatic fever. Ginsburg et al.
Edge modes in the fractional quantum Hall effect without extra edge fermions
Lima, G. L. S.; Dias, S. A.
2011-05-01
We show that the Chern-Simons-Landau-Ginsburg theory that describes the quantum Hall effect on a bounded sample is anomaly free and thus does not require the addition of extra chiral fermions on the boundary to restore local gauge invariance.
Understanding Educational Reform in Global Context: Economy, Ideology, and the State.
Ginsburg, Mark B., Ed.
This book presents a set of national case studies on educational reform of higher education that views reform as processes of ideological and social struggles. The titles and authors are as follows: "Educational Reform: Social Struggles, the State and the World Economic System" (Mark B. Ginsburg, et al.); "Restructuring Education…
Analysis of flux-flow curves in superconductors as a function of temperature
Boboshko, N.
1978-01-01
A phenomenological method to analyse the experimental data of flux-flow resistivity in superconductors as a function of temperature is proposed and successfully applied to existing data for t = kappa >= 0.07. An empirical curve relating the flux-flow resistivity with the Ginsburg-Landau parameter kappa was obtained. (author)
Taylor, Kelley R.
2009-01-01
"Chief Justice Flubs Oath." "Justice Ginsburg Has Cancer Surgery." At the start of this year, those were the news headlines about the U.S. Supreme Court. But January 2009 also brought news about key education cases--one resolved and two others on the docket--of which school administrators should take particular note. The Supreme Court updates on…
The Visual Rhetoric of Yoruba Video Films | Faniran | Humanities ...
As pointed out by Faye Ginsburg (2002:212), this cultural approach opens a new discursive space for indigenous media that respects and understands them on their own terms. It also leads to the appreciation of their producers as people who are creatively engaged in the process of constructing identities in ways that ...
Katayama fever ID scuba divers
1991-03-02
Mar 2, 1991 ... A. C. EVANS, D. J. MARTIN, B. D. GINSBURG. Summary. Katayama fever or acute schistosomiasis probably occurs more commonly than is recorded. Interviews with a 3-man scuba diving team who had had contact with a large dam in an·endemic area of the eastern Transvaal Lowveld at the same time ...
What's an Adult Numeracy Teacher to Teach? Negotiating the Complexity of Adult Numeracy Instruction
Ginsburg, Lynda
2017-01-01
In this Forum article, the author addresses how to assist adults in improving mathematics and numeracy literacy. Ginsburg observes educators who strive to address their learners' educational gaps and needs are finding themselves in an environment of competing priorities and expectations that can be expressed as mathematics numeracy education. What…
Editorial Coverage of Reagan Supreme Court Nominees.
Hale, F. Dennis
To measure the editorial advocacy of influential newspapers concerning the membership of the Supreme Court, a study analyzed editorials from such newspapers concerning the last five Supreme Court nominees of President Ronald Reagan (William Rehnquist, Antonin Scalia, Robert Bork, Douglas Ginsburg, and Anthony Kennedy). A telephone survey of 100…
Shayer, Michael; Ginsburg, Denise
2009-01-01
Background: Shayer, Ginsburg, and Coe (2007) showed that children leaving primary school in Y6 entered secondary school with much lower levels of understanding of the physical conservations than in 1976. It seemed desirable to investigate cognitive development in the first three years of secondary education. Aims: By using two Piagetian tests of…
Katayama fever in scuba divers - A report of 3 cases | Evans | South ...
Katayama fever in scuba divers - A report of 3 cases. A.C. Evans, D.J. Martin, B.D. Ginsburg. Abstract. Katayama fever or acute schistosomiasis probably occurs more commonly than is recorded. Interviews with a 3-man scuba diving team who had had contact with a large dam in an ·endemic area of the eastern Transvaal ...
Career Development: Issues of Gender, Race, and Class. Information Series No. 371.
Stitt-Gohdes, Wanda L.
The premise of this paper is that, although career choice implies options, issues of gender, race, and class may constrain the occupational choices an individual makes. Dominant career development theories are being reexamined for their appropriateness to diverse groups. This paper reviews the following theories: Ginzberg, Ginsburg, Axelrad, and…
Multicritical points in two dimensions, the renormalization group and the ε expansion
Howe, P.S.; West, P.C.
1989-01-01
We calculate, using the ε expansion, the critical exponents for the two-dimensional potential θ 2n . It is found that the results at lowest perturbative order are not in agreement with what would be expected from the proposed correspondence between such Landau-Ginsburg hamiltonians and minimal conformal field theories. (orig.)
Mineralogical and geochemical study of mud volcanoes in north ...
The gulf of Cadiz is one of the most interesting areas to study mud volcanoes and structures related to cold fluid seeps since their discovery in 1999. In this study, we present results from gravity cores collected from Ginsburg and Meknes mud volcanoes and from circular structure located in the gulf of Cadiz (North Atlantic ...
Gunderson, Elizabeth A.; Levine, Susan C.
2011-01-01
Before they enter preschool, children vary greatly in their numerical and mathematical knowledge, and this knowledge predicts their achievement throughout elementary school (e.g. Duncan et al., 2007; Ginsburg & Russell, 1981). Therefore, it is critical that we look to the home environment for parental inputs that may lead to these early…
Journal of Biosciences | Indian Academy of Sciences
2008-09-19
Sep 19, 2008 ... Author Affiliations. Simona Ginsburg1 Eva Jablonka2. Natural Science Department, The Open University of Israel, POB 808, Raanana, Israel; The Cohn Institute for the History and Philosophy of Science and Ideas, Tel-Aviv University, Tel-Aviv 66978, Israel ...
The Preschool Rating Instrument for Science and Mathematics (PRISM)
Brenneman, Kimberly; Stevenson-Garcia, Judi; Jung, Kwanghee; Frede, Ellen
2011-01-01
Until recently, few valid and reliable assessments were available to measure young children's mathematics and science learning in a "comprehensive" way. Now, a number of mathematics assessments have been developed and subjected to testing (Klein, Starkey, & Wakeley, 2000; Ginsburg, 2008; Clements & Sarama, 2008), and progress has…
Theories of Career Development. A Comparison of the Theories.
Osipow, Samuel H.
These seven theories of career development are examined in previous chapters: (1) Roe's personality theory, (2) Holland's career typology theory, (3) the Ginzberg, Ginsburg, Axelrod, and Herma Theory, (4) psychoanalytic conceptions, (5) Super's developmental self-concept theory, (6) other personality theories, and (7) social systems theories.…
Durden, Lance A; Knapp, Charles R; Beati, Lorenza; Dold, Stephanie
2015-02-01
Ticks were collected or recorded from 522 individual reptiles on Dominica and from 658 reptiles from the Bahamas. Two species of ticks were collected on Dominica: Amblyomma antillorum and Amblyomma rotundatum. Similarly, 2 species were collected in the Bahamas: Amblyomma albopictum and Amblyomma torrei. On Dominica, A. antillorum was recorded from 517 Lesser Antillean iguanas (Iguana delicatissima), 2 boa constrictors (Boa nebulosa), 1 Antilles snake (Alsophis sibonius), and 1 Dominican ground lizard (Ameiva fuscata), whereas A. rotundatum was recorded from 1 Lesser Antillean skink (Mabuya mabouya). In the Bahamas, A. albopictum was recorded from 131 Andros iguanas (Cyclura cychlura cychlura), 271 Exuma Island iguanas (Cyclura cychlura figginsi), and 1 Andros curlytail lizard (Leiocephalus carinatus coryi), whereas A. torrei was recorded from 255 Exuma Island iguanas. In the Bahamas, A. albopictum parasitized iguanas on Andros Island and the central Exuma Islands, and A. torrei parasitized iguanas in the southern Exumas. An exception to this trend was that A. torrei was collected from iguanas on Pasture Cay in the central Exumas, an anomaly that is explained by the fact that iguanas (with attached ticks) on Pasture Cay were introduced by humans in the past from islands further south. External hyperparasitic larval erythraeid mites ( Leptus sp.) were recorded from A. torrei in the Bahamas.
Effect of twinning plane on superconductor magnetic properties
Buzdin, A.I.; Kuptsov, D.A.
1989-01-01
Effect of twinning planes on pinning of the Abrikosov vortices in superconductors of the second order with the Ginsburg-Landau parameter, κ >> 1, is considered. The modified Ginsburg-Landau functional, where the effect of superconducting properties improvement near the twinning plane is taken into account by adding the additional δ-function component, is used to descibe superconductivity of twinning plane. Force of interaction of a vortex filament and the twinning plane is calculated. It is shown that in case of the twinning plane opaque to electrons, additional attractive force, being analogous to that occurring in the problem on the surface Been-Livingston barrier, affects the vortex filament. The results can explain anisotropy of vortex pinning observed in the periodic twinning structure in high-temperature superconductors
Nodes in an alternatively defined order parameter in HTSC
Nettel, Stephen
2008-10-01
In a previous study the BCS wave function was generalized to include the motion of the center-of-mass of Cooper pairs. It was found that the Ginsburg-Landau order parameter could be identified with a wave function describing this motion. Here attention is focussed on the effects of replacing free electron orbitals by Bloch waves. In the copper oxides, where the Fermi surface lies contiguous to the Brillouin zone boundary, and with pairs coupled by soft phonon modes, limitations on the wave vectors associated with the center-of-mass coordinates are found. These limitations lead to nodes in the Fourier transform of the Ginsburg-Landau order parameter. Possible relevance of the nodes to the more recently discovered properties of high TC superconductors is discussed.
Nodes in an alternatively defined order parameter in HTSC
Nettel, Stephen
2008-01-01
In a previous study the BCS wave function was generalized to include the motion of the center-of-mass of Cooper pairs. It was found that the Ginsburg-Landau order parameter could be identified with a wave function describing this motion. Here attention is focussed on the effects of replacing free electron orbitals by Bloch waves. In the copper oxides, where the Fermi surface lies contiguous to the Brillouin zone boundary, and with pairs coupled by soft phonon modes, limitations on the wave vectors associated with the center-of-mass coordinates are found. These limitations lead to nodes in the Fourier transform of the Ginsburg-Landau order parameter. Possible relevance of the nodes to the more recently discovered properties of high T C superconductors is discussed
Quantum phase transitions in semilocal quantum liquids
Iqbal, Nabil; Liu, Hong; Mezei, Márk
2015-01-01
We consider several types of quantum critical phenomena from finite-density gauge-gravity duality which to different degrees lie outside the Landau-Ginsburg-Wilson paradigm. These include: (i) a "bifurcating" critical point, for which the order parameter remains gapped at the critical point, and thus is not driven by soft order parameter fluctuations. Rather it appears to be driven by "confinement" which arises when two fixed points annihilate and lose conformality. On the condensed side, there is an infinite tower of condensed states and the nonlinear response of the tower exhibits an infinite spiral structure; (ii) a "hybridized" critical point which can be described by a standard Landau-Ginsburg sector of order parameter fluctuations hybridized with a strongly coupled sector; (iii) a "marginal" critical point which is obtained by tuning the above two critical points to occur together and whose bosonic fluctuation spectrum coincides with that postulated to underly the "Marginal Fermi Liquid" description of the optimally doped cuprates.
Singularity theory and N = 2 superconformal field theories
Warner, N.P.
1989-01-01
The N = 2 superconformal field theories that appear at the fixed points of the renormalization group flows of Landau-Ginsburg models are discussed. Some of the techniques of singularity theory are employed to deduce properties of these superconformal theories. These ideas are then used to deduce the relationship between Calabi-Yau compactifications and tensored discrete series models. The chiral rings of general N = 2 superconformal theories are also described. 14 refs
2013-01-09
intensity [6]. Although previous studies with dengue, melioidosis, tuberculosis, candidiasis , and sepsis have focused on diagnosis in patients as they...the quarantine. All subjects received oral oseltamivir (Roche Pharmaceuticals) 75 mg by mouth twice daily as treatment or prophylaxis at day 6...Lucas J, Perfect JR, Ginsburg GS (2010) Blood gene expression signatures predict invasive candidiasis . Sci Transl Med 2: 21ra17. 8. Berry MP, Graham
Minnhagen, P.; Weber, H.
1985-01-01
A Monte Carlo simulation of the Ginsburg-Landau Coulomb-gas model for vortex fluctuations is described and compared to the measured resistance scaling function for two-dimensional superconductors. This constitutes a new, more direct way of confirming the vortex-fluctuation explanation for the resistive tail of high-sheet-resistance superconducting films. The Monte Carlo data obtained indicate a striking accordance between theory and experiments
Domain walls of BaTiO.sub.3./sub. and PbTiO.sub.3./sub. within Ginzburg-Landau-Devonshire model
Hlinka, Jiří
2008-01-01
Roč. 375, č. 1 (2008), 132-137 ISSN 0015-0193 R&D Projects: GA ČR GA202/06/0411 Institutional research plan: CEZ:AV0Z10100520 Keywords : domain walls * Landau- Ginsburg theory * ferroelectricity * BaTiO 3 * PbTiO 3 Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 0.562, year: 2008
Magnetic phase transitions with incommensurate structures in systems with coupled order parameters
Izyumov, Yu.A.; Laptev, V.M.; Petrov, S.B.
1984-01-01
Modulated magnetic phases are investigated for the case when symmetry does not allow linear by gradients Lifshits invariants and magnetic momenta are converted by two irreducible representations. Possible phase diagrams with participation of incommensurable phases are plotted on the base of Ginsburg-Landau functional for 2 bound parameters of the order. The role of the highest harmonics in spatial distribution of the order parameters is clarified on the example of magnetic phase transitions in Er
Un apéndice ornamental a Reyes en el ms. M1 de la Universidad Complutense de Madrid
de Azcárraga, M. J.
2004-12-01
Full Text Available The analysis of the ornamental masorah of folio 158a of Manuscript M1 allows the author to correct and improve the description made by Ch. D. Ginsburg in his introduction to the Bible. The author indeed agrees on the identification of the text as a masoretic appendix to the books of Kings. However, the beginning and the contents of the manuscript must be revised. Ginsburg describes only one of the four lists of the appendix, namely the one dealing with the differences between Eastern and Western recensions; the other three lists are the following: sedarim, peseqim, and words vocalized with patah, which are exceptional because they are pausal forms.
El estudio detallado de la masora ornamental del folio 158a del manuscrito M1 me ha permitido corregir y puntualizar la descripción que hace de este folio Ch. D. Ginsburg en la Introducción a su Biblia. Por una parte, estamos de acuerdo en que se trata de un apéndice masorético a los libros de Reyes, pero no lo estamos en lo que se refiere al sitio donde comienza, ni al contenido total del mismo. Ginsburg sólo describe una lista de las cuatro que contiene, la de las diferencias entre los textos orientales y occidentales; las otras tres son: sedarîm, paseqîm y palabras vocalizadas con patah, que constituyen una excepción por estar en pausa.
Theory of the superconducting proximity effect below the transition temperature
Silvert, W.
1975-01-01
The form of the low-temperature theory of the superconducting proximity effect depends on whether the non-linear terms are assumed to depend only on the local value of the gap or on its average value over some finite range. The local assumption leads to smaller values of the gap and to unphysical results at low temperatures. The effect of non-locality is significant even in the Ginsburg-Landau regime. (author)
The critical current of superconductors: an historical review
Dew-Hughes, D.
2001-01-01
The most important practical characteristic of a superconductor is its critical current density. This article traces the history, both of the experimental discoveries and of the development of the theoretical ideas that have lead to the understanding of those factors that control critical current densities. These include Silsbee's hypothesis, the Meissner effect, London, Ginsburg-Landau and Abrikosov theories, flux pinning and the critical state, and the control of texture in high temperature superconductors
Aspects of high temperature superconductivity
Deutscher, G.
1989-01-01
We present some remarks on special features that distinguish the phenomenology of the new high T c oxides from that of the conventional superconductors. They include a measurable width of the critical region and a high sensitivity to crystallographic defects. A consistent Landau Ginsburg interpretation is possible, with a short coherence length <15 A and a penetration depth <900 A. The latter is somewhat smaller than the currently accepted value, and implies a broad band scheme
Extension of equilibrium formation criteria to metastable microalloys
Kaufmann, E.N.; Vianden, R.; Chelikowsky, J.R.; Phillips, J.C.
1977-01-01
Metastable microalloys of 25 metallic elements with beryllium have been prepared by ion implantation. The injected atoms have been found to occupy one of three sites available in the solvent lattice. A modified Laudau-Ginsburg expansion using bulk alloy variables proposed by Miedema is completely successful in predicting the observed metastable-site preferences and indicates a broader applicability of these variables than was heretofore anticipated
High-Tc superconductivity in the d-p electron system
Ivanov, V.A.; Zaitsev, R.A.
1991-01-01
The relaxation time with spin flip τ s and the parameters ξ, δ, χ of superconducting phase have been calculated on the basis of the kinematical mechanism of superconductivity in strongly correlated oxide models. An inter-relation between the superconducting gap Δ o and the specific heat jump Δ c allowing the experimental verification was obtained and the Ginsburg-Landau equation derived. (author). 8 refs., 2 figs
Structure of a compressible superfluid
Condat, C.A.; Guyer, R.A.
1981-01-01
A simple model of the spin-polarized hydrogen system in an external field is developed. The thermal and interaction support of the fluid work to prevent its collapse when the Bose-Einstein condensation occurs. The existence of the condensate causes a reduction in the thermal support of the fluid; the condensate is modeled with a local Ginsburg-Landau functional. The effects of temperature, sample size, and external field on the evolution of the fluid are explored
Properties of a magnetic superconductor with weak magnetization-application to ErNi2B2C
Ng, T.K.; Leung, W.T.
2001-01-01
Using a Ginsburg-Landau free-energy functional, we study the H-T phase diagram of a weak magnetic superconductor, where the magnetization from the magnetic component is marginal in supporting a spontaneous vortex phase. In particular, the competition between the spiral state and spontaneous vortex phase is analysed. Our theory is applied to understand the magnetic properties of ErNi 2 B 2 C. (orig.)
Ground state energy values and moments of the anharmonic oscillator
Seetharaman, M.; Raghavan, Sekhar; Subba Rao, G.
1981-01-01
It is shown that a very satisfactory estimate of the energy values (for all values of the anharmonicity) and moments of the ground state of the quartic anharmonic oscillator can be obtained in the variational method, by considering trial wavefunctions which have the correct asymptotic properties. The results derived with a single variational parameter are a considerable improvement over the recent results of C.A. Ginsburg and E.W. Montroll (1978). (author)
Analytic properties of the Ruelle ζ-function for mean field models of phase transition
Hallerberg, Sarah; Just, Wolfram; Radons, Guenter
2005-01-01
We evaluate by analytical means the Ruelle ζ-function for a spin model with global coupling. The implications of the ferromagnetic phase transitions for the analytical properties of the ζ-function are discussed in detail. In the paramagnetic phase the ζ-function develops a single branch point. In the low-temperature regime two branch points appear which correspond to the ferromagnetic state and the metastable state. The results are typical for any Ginsburg-Landau-type phase transition
Superconducting parameters of polycrystalline niobium films
Kandyba, P.E.; Kolesnikov, D.P.; Tkachev, V.A.
1978-01-01
The niobium semi-crystalline films, having a thickness of 200-5,050 A have been studied. The films have been produced by the electron-beam evaporation in the oilless vacuum and by the ionic plasma spraying with diode and triode methods. Determined have been the coherence length, the magnetic field penetration depth and the Ginsburg-andau parameter. An attempt is made to determine the electron states density of the Fermi surface
de la Nuez Hernández, Daril; Pastor Gutiérrez, Lourdes; Pérez Angulo, Alejandro; Piloto Cubero, Yuliet; Corrada Wong, Raúl Igor
2016-01-01
Fish populations of the Syngnathidae family, including the charismatic seahorse, have significantly declined worldwide during the last decades. Up to now, these populations have been poorly researched in their habitat in Cuba. The objective of this study was to determinate site fidelity and home range of the longsnout seahorse (Hippocampus reidi Ginsburg, 1933), which has been poorly studied and has been classified as a Data Deficient (DD) species by the IUCN. Sampling was conducted between A...
Rock, Adam J.; Coventry, William L.; Morgan, Methuen I.; Loi, Natasha M.
2016-01-01
Generally, academic psychologists are mindful of the fact that, for many students, the study of research methods and statistics is anxiety provoking (Gal, Ginsburg, & Schau, 1997). Given the ubiquitous and distributed nature of eLearning systems (Nof, Ceroni, Jeong, & Moghaddam, 2015), teachers of research methods and statistics need to cultivate an understanding of how to effectively use eLearning tools to inspire psychology students to learn. Consequently, the aim of the present paper is to...
Higher order terms in the inflation potential and the lower bound on the tensor to scalar ratio r
Destri, C.; Vega, H.J. de; Sanchez, N.G.
2011-01-01
Research highlights: → In Ginsburg-Landau (G-L) approach data favors new inflation over chaotic inflation. → n s and r fall inside a universal banana-shaped region in G-L new inflation. → The banana region for the observed value n s =0.964 implies 0.021 s and ratio r. Furthermore, we compute in close form the inflaton potential dynamically generated when the inflaton field is a fermion condensate in the inflationary universe. This inflaton potential turns out to belong to the Ginsburg-Landau class too. The theoretical values in the (n s , r) plane for all double well inflaton potentials in the Ginsburg-Landau approach (including the potential generated by fermions) fall inside a universal banana-shaped region B. The upper border of the banana-shaped region B is given by the fourth order double-well potential and provides an upper bound for the ratio r. The lower border of B is defined by the quadratic plus an infinite barrier inflaton potential and provides a lower bound for the ratio r. For example, the current best value of the spectral index n s = 0.964, implies r is in the interval: 0.021 < r < 0.053. Interestingly enough, this range is within reach of forthcoming CMB observations.
On (orientifold of) type IIA on a compact Calabi-Yau
Misra, A.
2004-01-01
We study the gauged sigma model and its mirror Landau-Ginsburg model corresponding to type IIA on the Fermat degree-24 hypersurface in WCP 4 [1,1,2,8,12] (whose blow-up gives the smooth CY 3 (3,243)) away from the orbifold singularities, and its orientifold by a freely-acting antiholomorphic involution. We derive the Picard-Fuchs equation obeyed a period integral of a parent N=2 type IIA theory. We obtain the Meijer's basis of solutions to the equation in the large and small complex structure limits (on the mirror Landau-Ginsburg side) of the abovementioned Calabi-Yau, and make some remarks about the monodromy properties associated at the same and another MATHEMATICAlly interesting point. Based on a recently shown N=1 four-dimensional triality between Heterotic on the self-mirror Calabi-Yau CY 3 (11,11), M theory on CY 3 (3,243) x S 1 /(Z 2 ) and F-theory on an elliptically fibered CY 4 with the base given by CP 1 x Enriques surface, we first give a heuristic argument that there can be no superpotential generated in the orientifold of of CY 3 (3,243), and then explicitly verify the same using a mirror symmetry formulation for the abovementioned hypersurface away from its orbifold singularities. We then discuss briefly the sigma model and the mirror Landau-Ginsburg model corresponding to the resolved Calabi-Yau as well. (Abstract Copyright [2004], Wiley Periodicals, Inc.)
Higher order terms in the inflaton potential and the lower bound on the tensor to scalar ratio r
Destri, C.; de Vega, H. J.; Sanchez, N. G.
2011-03-01
The MCMC analysis of the CMB + LSS data in the context of the Ginsburg-Landau approach to inflation indicated that the fourth degree double-well inflaton potential in new inflation gives an excellent fit of the present CMB and LSS data. This provided a lower bound for the ratio r of the tensor to scalar fluctuations and as most probable value r ≃ 0.05, within reach of the forthcoming CMB observations. In this paper we systematically analyze the effects of arbitrarily higher order terms in the inflaton potential on the CMB observables: spectral index ns and ratio r. Furthermore, we compute in close form the inflaton potential dynamically generated when the inflaton field is a fermion condensate in the inflationary universe. This inflaton potential turns out to belong to the Ginsburg-Landau class too. The theoretical values in the (ns, r) plane for all double well inflaton potentials in the Ginsburg-Landau approach (including the potential generated by fermions) fall inside a universal banana-shaped region B. The upper border of the banana-shaped region B is given by the fourth order double-well potential and provides an upper bound for the ratio r. The lower border of B is defined by the quadratic plus an infinite barrier inflaton potential and provides a lower bound for the ratio r. For example, the current best value of the spectral index ns = 0.964, implies r is in the interval: 0.021 < r < 0.053. Interestingly enough, this range is within reach of forthcoming CMB observations.
Flexoelectricity induced increase of critical thickness in epitaxial ferroelectric thin films
Zhou Hao; Hong Jiawang; Zhang Yihui; Li Faxin; Pei Yongmao; Fang Daining
2012-01-01
Flexoelectricity describes the coupling between polarization and strain/stress gradients in insulating crystals. In this paper, using the Landau-Ginsburg-Devonshire phenomenological approach, we found that flexoelectricity could increase the theoretical critical thickness in epitaxial BaTiO 3 thin films, below which the switchable spontaneous polarization vanishes. This increase is remarkable in tensile films while trivial in compressive films due to the electrostriction caused decrease of potential barrier, which can be easily destroyed by the flexoelectricity, between the ferroelectric state and the paraelectric state in tensile films. In addition, the films are still in a uni-polar state even below the critical thickness due to the flexoelectric effect.
Closed-form irreducible differential formulations of the Wilson renormalization group
Vvedensky, D.D.; Chang, T.S.; Nicoll, J.F.
1983-01-01
We present a detailed derivation of the one-particle--irreducible (1PI) differential renormalization-group generators originally developed by Nicoll and Chang and by Chang, Nicoll, and Young. We illustrate the machinery of the irreducible formulation by calculating to order epsilon 2 the characteristic time exponent z for the time-dependent Ginsburg-Landau model in the cases of conserved and nonconserved order parameter. We then calculate both z and eta to order epsilon 2 by applying to the 1PI generator an extension of the operator expansion technique developed by Wegner for the Wilson smooth-cutoff renormalization-group generator
Brandt, E.H.
1976-01-01
The elastic properties of the flux line lattice in Type II superconductors as calculated from the Ginsburg-Landau theory are discussed. They are non-local on a length scale much larger than the flux line distance and divergent at Hsub(c2). The compression modulus may become much smaller than its long-wavelength limit, B 2 /4π, and if the deformation is not homogeneous, at Hsub(c2) the modulus vanishes as (Hsub(c2) - B) 2 . At arbitrary induction the compression modulus of strain waves with wavelengths of several flux line distances is of the order of the (small) shear modulus. (author)
Borisevich, Albina; Chang, Hye Jung; Kalinin, Sergei; Morozovska, Anna; Chu, Ying-Hao; Yu, Pu; Ramesh, Ramamoorthy; Pennycook, Stephen
2011-03-01
Polarization, electric field, charge and potential across ferroelectric-oxide interfaces are obtained from direct atomic position mapping by aberration corrected scanning transmission electron microscopy combined with Ginsburg-Landau-Devonshire theory. We compare two antiparallel polarization orientations, which allows separation of the polarization and intrinsic interface charge contributions. Using the Born effective charges, the complete interface electrostatics is obtained in real space, providing an alternative method to holography. The results provide new microscopic insight into the thermodynamics of polarization distribution at the atomic level. Research is sponsored by the of Materials Sciences and Engineering Division, U.S. DOE.
Aharanov--Bohm currents in thin superconducting cylinders
Kunstatter, G.; Revzen, M.; Trainor, L.E.H.
1983-01-01
The Aharanov--Bohm effect is the influence of classically inaccessible electromagnetic fields on quantum wave functions. In this paper we consider the Ginsburg--Landau (GL) equations for the stationary states of a thin, superconducting cylinder in the presence of a curl-free, static electromagnetic potential corresponding to zero fields. We solve the GL equations explicitly to obtain self-consistent solutions for the current density, the induced field and the free energy in a well-defined and accessible approximation. The analysis makes quantitative predictions which can, in principle, be experimentally tested to provide a clear and convincing demonstration of the Aharanov--Bohm effect
Critical unpairing currents in narrow niobium films
Gershenzon, M.E.; Gubankov, V.N.
1979-01-01
Investigated are the dependences of critical currents of narrow ( with the width of W=0.5-15 μm) superconducting niobium films on temperature and a magnetic field. The proposed method of film production with the width of the 1μm order and with small edge inhomogeneities ((<=500 A) permitted to realize the Ginsburg-Landau unpairing currents in the wide range of temperatures. The correct comparison with the theory showed that the unpairing currents are observed if W(< or approximately) 2delta, where delta is the effective depth of the penetration of the perpendicular magnetic field
Lower critical field of an anisotropic type-II superconductor
Klemm, R.A.; Clem, J.R.
1980-01-01
We consider the Ginzburg-Landau free energy of the anisotropic mass form in the presence of a magnetic field of arbitrary fixed direction. It is shown that the free energy may be transformed into the isotropic Ginsburg-Landau form with a kappa that depends upon the direction of the magnetic induction B relative to the crystal lattice. The lower critical field H/sub c/1 is then found for arbitrary direction of B. For highly anisotropic crystals the angular dependence of H/sub c/1 can exhibit a discontinuity or a cusp. The special case of a crystal with uniaxial symmetry is considered in detail
Critical Fluctuations in Spatial Complex Networks
Bradde, Serena; Caccioli, Fabio; Dall'Asta, Luca; Bianconi, Ginestra
2010-05-01
An anomalous mean-field solution is known to capture the nontrivial phase diagram of the Ising model in annealed complex networks. Nevertheless, the critical fluctuations in random complex networks remain mean field. Here we show that a breakdown of this scenario can be obtained when complex networks are embedded in geometrical spaces. Through the analysis of the Ising model on annealed spatial networks, we reveal, in particular, the spectral properties of networks responsible for critical fluctuations and we generalize the Ginsburg criterion to complex topologies.
Chen Xiaojia; Xu Zhuan; Jiao Zhengkuan; Zhang Qirui
1997-01-01
The nonmonotonic dependence of the superconducting transition temperature on the number of CuO 2 layers (n) per unit cell for mercury-based cuprate systems is investigated with the framework of the electrostatic model and the Ginsburg-Landau theory. It is found that the largest value of the normalized density of states is 1.8 when n=3, which corresponds to the highest T c in this series. Using reasonable parameters we predict an upper limit of T c of 160 K. (orig.)
Critical region of a type II superconducting film near Hsub(c2): rational approximants
Ruggeri, G.J.
1979-01-01
The high-temperature perturbative expansions for the thermal quantities of a type II superconducting film are extrapolated to the critical region near Hsub(c2) by means of new rational approximants of the Pade type. The new approximants are forced to reproduce the leading correction to the flux lattice contribution on the low-temperature side of the transition. Compared to those previously considered in the literature: (i) the mutual consistency of the approximants is improved; and (ii) they are nearer to the exact solution of the zero-dimensional Landau-Ginsburg model. (author)
Superconductivity in Th-Nb composites
Goodrich, L.F.
1980-01-01
Heat capacities, critical temperatures and critical currents have been measured for directionally solidified eutectic Th-Nb wires in order to determine whether superconductor-normal metal boundary is a strong pinning center for quantized vortices. The heat capacity data show that there is a large change in pair potential at the super-normal boundaries as predicted by de Gennes boundary conditions. The T/sub c/ data were used to evaluate the extrapolation length b, and to show that Ginsburg-Landau predicts the changes in the superconductors rather well. Hence, the equilibrium thermodynamical properties are predicted from the filament size and spacing rather well
Anisotropic superconducting state parameters of Tl-2212 superconductors
Khaskalam, Amit K.; Singh, R.K.; Varshney, Dinesh
2001-01-01
We have estimated the superconducting state parameters and their anisotropy in thallium based superconductors (Tl-2212), in the frame work of Fermi liquid approach. Determination of the effective mass of the charge carriers from the Fermi velocity and estimated anisotropic superconducting state parameters, particularly, the magnetic penetration depth along and perpendicular to the conducting plane. The coherence length along and perpendicular to the ab plane is evaluated and appears to be higher. The temperature dependence of penetration depth, their anisotropy and Ginsburg Landau parameter for optimised doped Tl based cuprates shows the power law. The technique permits a consistency with the reported data. (author)
Introduction to superconductivity
Darriulat, Pierre
1998-01-01
The lecture series will address physicists, such as particle and nuclear physicists, familiar with non-relativistic quantum mechanics but not with solid state physics. The aim of this introduction to low temperature superconductivity is to give sufficient bases to the student for him/her to be able to access the scientific literature on this field. The five lectures will cover the following topics : 1. Normal metals, free electron gas, chambers equation. 2. Cooper pairs, the BCS ground state, quasi particle excitations. 3. DC superconductivity, Meissner state, dirty superconductors.4. Self consistent approach, Ginsburg Landau equations, Abrikosov fluxon lattice. 5. Josephson effects, high temperature superconductivity.
Modelling of dielectric hysteresis loops in ferroelectric semiconductors with charged defects
Morozovska, Anna N; Eliseev, Eugene A
2004-01-01
We have proposed the phenomenological description of dielectric hysteresis loops in ferroelectric semiconductors with charged defects and prevailing extrinsic conductivity. We have modified the Landau-Ginsburg approach and shown that the macroscopic state of the aforementioned inhomogeneous system can be described by three coupled equations for three order parameters. Both the experimentally observed coercive field values well below the thermodynamic values and the various hysteresis-loop deformations (constricted and double loops) have been obtained in the framework of our model. The obtained results quantitatively explain the ferroelectric switching in such ferroelectric materials as thick PZT films
Regeneralized London free energy for high-Tc vortex lattices
M. A. Shahzamanian
2006-09-01
Full Text Available The London free-energy is regeneralized by the Ginsburg-Landau free-energy density in the presence of both d and s order parameters. We have shown that the strength of the s-d coupling, makes an important rule to determine the form of the lattice vortex. Appearance of the ratios of the coherence length to penetration depth in the higher order corrections of the free-energy density will truncate these corrections for even large values of .
High critical magnetic field superconductor La3S4
Westerholt, K.; Bach, H.; Wendemuth, R.; Methfessel, S.
1979-01-01
A report is presented on electrical conductivity, specific heat and magnetization measurements on La 3 S 4 single crystals. The results show that La 3 S 4 is a strong coupling superconductor with a BCS coherence length of 132 A. This extremely low value makes La 3 S 4 an intrinsic high critical magnetic field superconductor with a Landau-Ginsburg parameter of 20. For the temperature gradient of the upper critical magnetic field at the transition temperature values are found up to 35 kG/K. (author)
Negative self-inductance in superconducting thin wires and weak links
Christiansen, P.V.; Hansen, E.B.; Sjostrom, C.J.
1971-01-01
The concept of negative self-inductance is explained by deriving the velocity dependence of the superinductance on the basis of the uniform Ginsburg-Landau (GL) solution. A formulation of the GL theory is presented which is suited for describing the depairing effects in a thin wire or film. The stability of the solutions to the GL equations is discussed. It is found that for a long wire or film negative self-inductance and instability always go together. An application of the developed theory to weak links is considered
Critical fields of niobium nitride films of various granularity
Antonova, E.A.; Sukhov, V.A.
1983-01-01
The behaviour of lattice parameter, specific electrical resistivity, critical temperature, and temperature dependence of upper critical field near Tsub(cr) of sputtered niobium nitride films is investigated versus the substrate temperature and gas mixture composition in the process of reactive cathode sputtering. The relation between extrapolated value of the upper critical field and granularity of niobium nitride films, close as to composition to the stoichiometric one, has been found. Values of the kappa parameter of the Ginsburg-Landau theory and of the coherence length for niobium nitride films of various granularity are estimated in an approximation of uniform distribution of impurities in a sample
Monte Carlo Simulations of Compressible Ising Models: Do We Understand Them?
Landau, D. P.; Dünweg, B.; Laradji, M.; Tavazza, F.; Adler, J.; Cannavaccioulo, L.; Zhu, X.
Extensive Monte Carlo simulations have begun to shed light on our understanding of phase transitions and universality classes for compressible Ising models. A comprehensive analysis of a Landau-Ginsburg-Wilson hamiltonian for systems with elastic degrees of freedom resulted in the prediction that there should be four distinct cases that would have different behavior, depending upon symmetries and thermodynamic constraints. We shall provide an account of the results of careful Monte Carlo simulations for a simple compressible Ising model that can be suitably modified so as to replicate all four cases.
Analysis of the susceptibility in a fluid system with Neumann – plus boundary conditions
Djondjorov Peter
2018-01-01
Full Text Available The behaviour of the local and total susceptibilities of a fluid system bounded by different surfaces is studied in the framework of the Ginsburg-Landau Ising type model. The case of a plain geometry, Neumann-infinity boundary conditions under variations of the temperature and an external ordering field is considered. Exact analytic expressions for the order parameter, local and total susceptibilities in such a system are presented. They are used to analyse the phase behaviour of fluids confined in regions close to the bulk critical point of the respective infinite system.
Elastic constants and the structural phase transition in La2-xSrxCuO4
Sarrao, J.L.; Lei, Ming; Stekel, A.; Bell, T.M.; Leisure, R.G.; Sham, L.J.; Visscher, W.M.; Migliori, A.; Bussmann-Holder, A.; Tanaka, I.; Kojima, H.
1991-01-01
Resonant ultrasound spectroscopy is used to measure the temperature dependence of all six elastic moduli of La 2-x Sr x CuO 4 . A giant softening (> 50% reduction) in the in-plane shear modulus, c 66 , is observed and is attributed to the tetragonal-orthorhombic structural phase transition in this material. This phase transition and the corresponding softening is examined with a simple anharmonic mechanical model and a macroscopic Ginsburg-Landau formalism exploiting the full symmetry of the crystal. 16 refs., 5 figs
Talamo, Alberto
2007-01-01
We analytically evaluated the fuel coefficient of temperature both for pebble bed and prismatic high temperature reactors when they utilize as fuel plutonium and minor actinides from light water reactors spent fuel or a mixture of 50% uranium, enriched 20% in 235 U, and 50% thorium. In both cores the calculation involves the evaluation of the resonances integrals of the high absorbers fuel nuclides 240 Pu, 238 U and 232 Th and it requires the esteem of the Dancoff-Ginsburg factor for a pebble bed or prismatic core. The Dancoff-Ginsburg factor represents the only discriminating parameter in the results for the two different reactors types; in fact, both the pebble bed and the prismatic reactors share the same the pseudo-cross-section describing an infinite medium made of graphite filled by TRISO particles. We considered only the resolved resonances with a statistical spin factor equal to one and we took into account 267, 72, 212 resonances in the range 1.057-5692, 6.674-14485, 21.78-3472 eV for 240 Pu, 238 U and 232 Th, respectively, for investigating the influence on the fuel temperature reactivity coefficient of the variation of the TRISO kernel radius and TRISO particles packing fraction from 100, 200 to 300 μm and from 10% to 50%, respectively. Finally, in the pebble bed core, we varied the radius of the pebble for setting a fuel temperature reactivity coefficient similar to the one of a prismatic core
Jowzani-Moghaddam, A.
1981-01-01
An integral transport method of calculating the geometrical shadowing factor in multiregion annular cells for infinite closely packed lattices in cylindrical geometry is developed. This analytical method has been programmed in the TPGS code. This method is based upon a consideration of the properties of the integral transport method for a nonuniform body, which together with Bonalumi's approximations allows the determination of the approximate multiregion collision probability matrix for infinite closely packed lattices with sufficient accuracy. The multiregion geometrical shadowing factors have been calculated for variations in fuel pin annular segment rings in a geometry of annular cells. These shadowing factors can then be used in the calculation of neutron transport from one annulus to another in an infinite lattice. The result of this new geometrical shadowing and collision probability matrix are compared with the Dancoff-Ginsburg correction and the probability matrix using constant shadowing on Yankee fuel elements in an infinite lattice. In these cases the Dancoff-Ginsburg correction factor and collision probability matrix using constant shadowing are in difference by at most 6.2% and 6%, respectively
The eastern Pacific species of Bathygobius (Perciformes: Gobiidae).
Miller, P J; Stefanni, S
2001-07-01
The circumtropical gobiid genus Bathygobius Bleeker is defined and three Eastern Pacific species are redescribed, with first dorsal fin pattern and postorbital blotches being shown to be additional characters of diagnostic value. Two mainland species are recognised, the Mexican-Panamanian B. ramosus Ginsburg 1947 and the Panamanian B. andrei (Sauvage 1880). B. ramosus is now reported from Clarión Island, Revillagigedos, and also from Cocos Island. Meristic variation of ramosus is tabulated for local populations and PCA analysis of their morphometry suggests regional differentiation in this species, with Tres Marias and Revillagigedos populations clustering away from mainland and Montuosa material. An insular species, B. lineatus (Jenyns 1842) from the Galapagos is defined, with B. arundelii (Garman 1899) from Clipperton Island and B. l. lupinus Ginsburg 1947 from Lobos de Afuera, off Peru, placed as nominal subspecies of lineatus. This species resembles the Indo-west Pacific B. fuscus and Atlantic basin B. soporator more closely than it does ramosus and andrei and may be the product of transpacific dispersal. A similar origin for B. ramosus is discussed but it seems more likely that both B. ramosus and B. andrei have Caribbean sister species.
Geometric singularities and spectra of Landau-Ginzburg models
Greene, B.R.; Roan, S.S.; Yau, S.T.
1991-01-01
Some mathematical and physical aspects of superconformal string compactification in weighted projective space are discussed. In particular, we recast the path integral argument establishing the connection between Landau-Ginsburg conformal theories and Calabi-Yau string compactification in a geometric framework. We then prove that the naive expression for the vanishing of the first Chern class for a complete intersection (adopted from the smooth case) is sufficient to ensure that the resulting variety, which is generically singular, can be resolved to a smooth Calabi-Yau space. This justifies much analysis which has recently been expended on the study of Landau-Ginzburg models. Furthermore, we derive some simple formulae for the determination of the Witten index in these theories which are complementary to those derived using semiclassical reasoning by Vafa. Finally, we also comment on the possible geometrical significance of unorbifolded Landau-Ginzburg theories. (orig.)
The history of cholinesterase reactivation: hydroxylamine and pyridinium aldoximes.
Petroianu, G A
2012-10-01
Hydroxylamine (NH2OH) the substance which will turn out to be of importance to those interested in the treatment of organophosporus cholinesterase inhibitor exposure, was synthesized by Wilhem Clemens Lossen in 1865 while working in Halle as an assistant in the laboratory of Wilhelm Heinrich Heintz. The Lossen synthesis generated hydroxylamine in aqueous solution. Anhydrous hydroxylamine was prepared almost simultaneously by Lobry de Bruyn and Crismer (1891). Using hydroxylamine as a starting point Meyer synthesized aldoximes and ketoximes (1897). Lange, a PhD student of Ladenburg, isolated 2-methyl-pyridine (alpha-picoline). Some fifty years later Wilson, working in the laboratory of Nachmansohn, demonstrated the ability of hydroxylamine to reactivate cholinesterase inhibited by organophosphates. Finally Wilson and Ginsburg using 2-methyl-pyridine as a starting point synthesized the first pyridinium aldoxime reactivator of clinical relevance, pralidoxime (1955).
Liu Chaoqian; Fei Weidong; Li Weili
2008-01-01
It is well accepted that textures in polycrystalline films have significant effects on film properties. The magnetoelectric (ME) coupling in a 2-2-type multiferroic composite film was theoretically discussed using Landau-Ginsburg-Devonshire theory, where the influences of dispersive texture and residual stress were considered. As an example, the 2-2-type CoFe 2 O 4 /BaTiO 3 composite film was theoretically analysed, wherein the case of both the magnetostrictive phase and the piezoelectric phase with (0 0 1)-oriented texture was considered. Our results show that the ME coupling is enhanced with the texture degree of the piezoelectric phase and/or the magnitude of the residual tensile stress, but weakened with the magnitude of residual compressive stress. With increasing texture degree of the magnetostrictive phase, the ME coupling is enhanced when the texture degree is smaller than a critical value, but weakened when the texture degree is larger than the critical value
Researching media through practices: an ethnographic approach
Antoni Roig
2009-05-01
Full Text Available Anthropological and ethnographic research on media have been largely focused on analyzing reception of media products (television, radio, press and film and media consumption related to domestic appropriation of technologies (Rothenbuhler et al., 2005. There is also a wide body of research devoted to the study of the political dimension of alternative and indigenous media (Ginsburg, 2002. However, there has been a separation between media and internet studies, and between the analysis of media reception and practices of self-production, such as family photography or home video. Current digital media practices urge reexamination of self-produced content and media flows from a broader perspective that cuts across divisions between public and private, corporative media products and people's releases, home production and cultural industry, political activism and everyday life.
Superconductivity and spin fluctuations in M-Zr metallic glasses (M = Cu, Ni, Co, and Fe)
Altounian, Z.; Strom-Olsen, J.O.
1983-01-01
The superconducting transition temperature, upper critical field, and magnetic susceptibility have been measured in four binary metallic glass systems: Cu-Zr, Ni-Zr, Co-Zr, and Fe-Zr. For each alloy system, a full and continuous range of Zr-rich compositions accessible by melt spinning has been examined. For Cu-Zr, the range is 0.75>x>0.30; for Ni-Zr, 0.80>x>0.30; for Co-Zr, 0.80>x>0.48, and for Fe-Zr, 0.80>x>0.55 (x being the concentration of Zr in at. %). The results show clearly the influence of spin fluctuations in reducing the superconducting transition temperature. The data have been successfully analyzed using a modified form of the McMillan equation together with expressions for the Stoner enhanced magnetic susceptibility and the Ginsburg-Landau-Abrikosov-Gor'kov expression for the upper critical field
Nonlinear spin fluctuations in the Fermi liquid of itinerant electron ferromagnets
Solontsov, A.; Lacroix, C.
2003-01-01
A microscopic derivation of nonlinear equations of magnetic dynamics for itinerant ferromagnets is presented within the electron Fermi liquid model accounting for both long-range Coulomb and short-range interactions of quasiparticles, which founds the basis for the phenomenological description of nonlinear spin fluctuations (SF) using the Ginsburg-Landau formalism. Crystal lattice is shown to play a significant role screening the long-range Coulomb interaction and affecting magnetic dynamics. The spectrum of longitudinal SF with account of nonlinear mode-mode coupling is shown to result from an interplay of quasielastic SF and inelastic excitations near the magnon frequencies, both having mainly the nonlinear nature and arising due to their emission (absorption) by magnons
Vavilov-Cherenkov and Synchrotron Radiation Foundations and Applications
Afanasiev, G. N
2005-01-01
The theory of the Vavilov-Cherenkov radiation observed by Cherenkov in 1934 was created by Tamm, Frank and Ginsburg who associated the observed blue light with the uniform charge motion of a charge at a velocity greater than the velocity of light in the medium. On the other hand, Vavilov, Cherenkov's teacher, attributed the observed blue light to the deceleration of electrons. This has given rise to the appearance of papers in which the radiation of a charge uniformly moving in a finite space interval was related to the Bremsstrahlung arising at the end points of the motion interval. This monograph is intended for students of the third year and higher, for postgraduates, for professional scientists (both experimentalists and theoreticians) dealing with Vavilov-Cherenkov and synchrotron radiation. An acquaintance with the three volumes of the Landau and Lifshitz course (Quantum Mechanics, Classical Field Theory and Macroscopic Electrodynamics) is sufficient for understanding the text.
Fang Chao; Chen Liangyan; Zhou Dongxiang
2013-01-01
The dielectric property of BaTiO 3 nanoparticles and nanoceramics has been studied on the basis of Ginsburg-Landau-Devonshire thermodynamic theory. In this paper, considering nanodomains, Landau coefficients have been written as a function of grain size, and the dielectric constant of the material has been calculated at a variety of temperatures and grain size. The results indicate that with decreasing grain size, the dielectric peak decreases. The two lower dielectric peaks of the orthorhombic-rhombohedral phase and tetragonal-orthorhombic phase move to higher temperature, while cubic-tetragonal phase dielectric peak moves to lower temperature. The dielectric constant of BaTiO 3 ceramics decreases with decreasing grain size. The dielectric constant peak at room temperature is at the grain size which is larger than the critical grain size 17-30 nm. The calculated result is consistent with the experimental data.
Critical properties of the Kitaev-Heisenberg Model
Sizyuk, Yuriy; Price, Craig; Perkins, Natalia
2013-03-01
Collective behavior of local moments in Mott insulators in the presence of strong spin-orbit coupling is one of the most interesting questions in modern condensed matter physics. Here we study the finite temperature properties of the Kitaev-Heisenberg model which describe the interactions between the pseudospin J = 1 / 2 iridium moments on the honeycomb lattice. This model was suggested as a possible model to explain low-energy physics of AIr2O3 compounds. In our study we show that the Kitaev-Heisenberg model may be mapped into the six state clock model with an intermediate power-law phase at finite temperatures. In the framework of the Ginsburg-Landau theory, we provide an analysis of the critical properties of the finite-temperature ordering transitions. NSF grant DMR-1005932
Itinerant density instability at classical and quantum critical points
Feng, Yejun; van Wezel, Jasper; Flicker, Felix; Wang, Jiyang; Silevitch, D. M.; Littlewood, P. B.; Rosenbaum, T. F.
2015-03-01
Itinerant density waves are model systems for studying quantum critical behavior. In both the model spin- and charge-density-wave systems Cr and NbSe2, it is possible to drive a continuous quantum phase transition with critical pressures below 10 GPa. Using x-ray diffraction techniques, we are able to directly track the evolution of the ordering wave vector Q across the pressure-temperature phase diagram. We find a non-monotonic dependence of Q on pressure. Using a Landau-Ginsburg theoretical framework developed by McMillan for CDWs, we evaluate the importance of the physical terms in driving the formation of ordered states at both the thermal and quantum phase transitions. We find that the itinerant instability is the deciding factor for the emergent order, which is further influenced by the critical fluctuations in both the thermal and quantum limits.
Phase Diagram of a Simple Model for Fractional Topological Insulator
Chen, Hua; Yang, Kun
2012-02-01
We study a simple model of two species of (or spin-1/2) fermions with short-range intra-species repulsion in the presence of opposite (effetive) magnetic field, each at filling factor 1/3. In the absence of inter-species interaction, the ground state is simply two copies of the 1/3 Laughlin state, with opposite chirality. Due to the overall time-reversal symmetry, this is a fractional topological insulator. We show this phase is stable against moderate inter-species interactions. However strong enough inter-species repulsion leads to phase separation, while strong enough inter-species attraction drives the system into a superfluid phase. We obtain the phase diagram through exact diagonalization caluclations. Nature of the fractional topological insluator-superfluid phase transition is discussed using an appropriate Chern-Simons-Ginsburg-Landau effective field theory.
Fang Chao, E-mail: yyohjh@sina.com [Department of Electrical and Electronic Engineering, Wuhan Polytechnic University, Wuhan 430023 (China); Chen Liangyan [Department of Electrical and Electronic Engineering, Wuhan Polytechnic University, Wuhan 430023 (China); Zhou Dongxiang [Department of Electronic Science and Technology, Huazhong University of Science and Technology, Wuhan City Hubei Province 430074 (China)
2013-01-15
The dielectric property of BaTiO{sub 3} nanoparticles and nanoceramics has been studied on the basis of Ginsburg-Landau-Devonshire thermodynamic theory. In this paper, considering nanodomains, Landau coefficients have been written as a function of grain size, and the dielectric constant of the material has been calculated at a variety of temperatures and grain size. The results indicate that with decreasing grain size, the dielectric peak decreases. The two lower dielectric peaks of the orthorhombic-rhombohedral phase and tetragonal-orthorhombic phase move to higher temperature, while cubic-tetragonal phase dielectric peak moves to lower temperature. The dielectric constant of BaTiO{sub 3} ceramics decreases with decreasing grain size. The dielectric constant peak at room temperature is at the grain size which is larger than the critical grain size 17-30 nm. The calculated result is consistent with the experimental data.
Dynamics of an N-vortex state at small distances
Ovchinnikov, Yu. N.
2013-01-01
We investigate the dynamics of a state of N vortices, placed at the initial instant at small distances from some point, close to the "weight center" of vortices. The general solution of the time-dependent Ginsburg-Landau equation for N vortices in a large time interval is found. For N = 2, the position of the "weight center" of two vortices is time independent. For N ≥ 3, the position of the "weight center" weakly depends on time and is located in the range of the order of a 3, where a is a characteristic distance of a single vortex from the "weight center." For N = 3, the time evolution of the N-vortex state is fixed by the position of vortices at any time instant and by the values of two small parameters. For N ≥ 4, a new parameter arises in the problem, connected with relative increases in the number of decay modes.
Impurity dependence of superconductivity in niobium
Laa, C.
1984-04-01
Jump temperatures, the critical fields Hsubc and Hsubc 2 and specific heats were measured on niobium samples where the impurity content was systematically varied by loading with nitrogen. Quantities could thus be extrapolated to lattice perfection and absolute purity. Comparisons with theories were made and some parameters extracted. Agreement was found with Gorkov theory for small impurities. A new value of the Ginsburg-Landau parameter Ko was determined to be just above 1/sqrt2 which proves that niobium is an elementary Type II semiconductor. By comparisons with the BCS and the CLAC theory the values of the mean Fermi velocity, the London penetration depth, the BCS coherence length and the impurity parameter were extracted. (G.Q.)
Surface bond contraction and its effect on the nanometric sized lead zirconate titanate
Haitao Huang; Sun, Chang Q.; Hing, Peter
2000-01-01
The grain size effect of lead zirconate titanate PbZr 1-x Ti x O 3 (PZT, x≥0.6) caused by surface bond contraction has been investigated by using the Landau-Ginsburg-Devonshire (LGD) phenomenological theory. It has been shown that, due to the surface bond contraction, both the Curie temperature and the spontaneous polarization of tetragonal PZT decrease with decreasing grain size. These effects become more significant when the grain size is in the nanometre range. A dielectric anomaly appears with decreasing grain size, which corresponds to a size dependent phase transformation. The ferroelectric critical size below which a loss of ferroelectricity will happen is estimated from the results obtained. (author). Letter-to-the-editor
Combined optical and electrical effects in ferroelectric crystal for high laser intensities
Kukhtarev, N. V.; Kukhtareva, T. V.; Stargell, G.; Wang, J. C.
2009-08-01
In this study, we have derived equations for the pyroelectric and photogalvanic contribution to the electrical charging of the photosensitive ferroelectric crystal. Standard photorefractive equations are supplemented by the equation of state for the polarization density following the Devonshire-Ginsburg-Landau (DGL) approach. The photogalvanic voltage and current is considered for a wide intensity range, which includes the CW and the pulsed photo-excitation with high intensities when the impurity is fully ionized and when the traditional linear-recombination approach is not valid. The crystal electrostatic accelerators, based on charging of ferroelectric crystals by pyroelectric and photogalvanic effects, are discussed in relation to the generation of the self-focused electron beam, X-rays, and neutrons.
Flexoelectricity induced increase of critical thickness in epitaxial ferroelectric thin films
Zhou Hao [State Key Laboratory for Turbulence and Complex Systems, College of Engineering, Peking University, Beijing 100871 (China); Hong Jiawang; Zhang Yihui [Department of Engineering Mechanics, Tsinghua University, Beijing 100084 (China); Li Faxin [State Key Laboratory for Turbulence and Complex Systems, College of Engineering, Peking University, Beijing 100871 (China); Pei Yongmao, E-mail: peiym@pku.edu.cn [State Key Laboratory for Turbulence and Complex Systems, College of Engineering, Peking University, Beijing 100871 (China); Fang Daining, E-mail: fangdn@pku.edu.cn [State Key Laboratory for Turbulence and Complex Systems, College of Engineering, Peking University, Beijing 100871 (China); Department of Engineering Mechanics, Tsinghua University, Beijing 100084 (China)
2012-09-01
Flexoelectricity describes the coupling between polarization and strain/stress gradients in insulating crystals. In this paper, using the Landau-Ginsburg-Devonshire phenomenological approach, we found that flexoelectricity could increase the theoretical critical thickness in epitaxial BaTiO{sub 3} thin films, below which the switchable spontaneous polarization vanishes. This increase is remarkable in tensile films while trivial in compressive films due to the electrostriction caused decrease of potential barrier, which can be easily destroyed by the flexoelectricity, between the ferroelectric state and the paraelectric state in tensile films. In addition, the films are still in a uni-polar state even below the critical thickness due to the flexoelectric effect.
On the theory of twinning plane superconductivity
Mishonov, T.M.
1988-01-01
The thermodynamic potential of the superconducting layer in the twinning plane (TP) vicinity for the type I superconductors is found. The corrections to the surface tension in powers of the Ginsburg-Landau parameter κ are obtained. The corresponding states law for the supercooling field for the type I twinning plane superconductivity (TPS) is obtained, as well as the critical field law for the type II TPS. A review of experimental and theoretical works on TPS and some similar systems is given. The conditions for the Berezinski-Kosterlitz-Thouless transition for the proximity effect are discussed, as well as the possible mechanisms for the conducting phase transition TPS in Nb and the pinning forces close to the twinning plane. The obtained order parameter distribution can be used for description of the superlattices from normal and superconducting metals as well. 6 figs., 44 refs
Experimental test of proximity effect theories by surface impedance measurements on the Pb-Sn system
Hook, J.R.; Battilana, J.A.
1976-01-01
The proximity effect in the Pb-Sn system in zero magnetic field has been studied by measuring the surface impedance at 3 GHz of a thin film of tin evaporated on to a bulk lead substrate. The results are compared with the predictions of theories of the proximity effect. It is found that good agreement can be obtained by using a theory due to Hook and Waldram of the spatial variation of the superconducting order parameter Δ inside each metal together with suitable boundary conditions on Δ at the interface between the metals. The required boundary conditions are a generalization to the case of non-zero electron reflection at the interface of the boundary conditions given by Zaitsev for the Ginsburg-Landau equation. (author)
Disorder and the upper critical field of Nb3Ge
Habermeier, H.U.
1981-01-01
The upper critical field, H/sub c2/, as determined from experimental values of T/sub c/ and (dH/sub c2//dT)/sub Tc/, has been investigated in Nb 3 Ge superconducting thin films with different degree of structural disorder. An increase of H/sub c2/(O) up to 36.9 T was found for samples with resistivities ranging from 40 to 60 /mu/sub/ OMEGA/cm and a decrease of H/sub c2/(O) to 5.7 T for /rho/.150 /mu/sub/ OMEGA/cm. Based on the Ginsburg-Landau solution for H/sub c2/(O) and the change of the coherence length with the electron mean free path a model is presented which describes the change of H/sub c2/(O) with resistivity, qualitatively. 15 refs
Intrinsic pinning in superconductors with extremely small coherence lengths
Schimmele, L.; Kronmueller, H.; Teichler, H.
1988-01-01
By means of a Ginsburg-Landau-type theory which takes into account the discrete lattice structure the variation of the energy ('Peierls potential') of an isolated flux line is calculated when shifted relatively to the crystal lattice. In particular, a primitive cubic lattice is considered with a straight flux line, aligned parallel to a cubic axis. The resulting Peierls potential may lead to intrinsic pinning if the coherence length is smaller than about two nearest neighbour distances. The coherence lengths at low temperatures determined for the recently discovered high T c superconductors of the YBa 2 Cu 3 O 7 class come very close to this value so that intrinsic pinning might possibly be relevant for these superconductors. (author)
Fang, Chao; Liu, Wei Hua
2017-07-01
The influence of the surface effect on the ferroelectric property of strained barium titanate film has been investigated. In this study, based on time-dependent Ginsburg-Landau-Devonshire thermodynamic theory, the surface effects have been simulated by introducing a surface constant, which leads to the strained BaTiO3 film consisting of inner tetragonal core and gradient lattice strain layer. Further, surface effects produce a depolarization field which has a dominant effect on the ferroelectric properties of the films. The spontaneous polarization, dielectric properties and ferroelectric hysteresis loop of BaTiO3 film are calculated under different boundary conditions. Theoretical and experimental results for strained BaTiO3 film are compared and discussed.
Algebraic geometry and effective lagrangians
Martinec, E.J.; Chicago Univ., IL
1989-01-01
N=2 supersymmetric Landau-Ginsburg fixed points describe nonlinear models whose target spaces are algebraic varieties in certain generalized projective spaces; the defining equation is precisely the zero set of the superpotential, considered as a condition in the projective space. The ADE classification of modular invariants arises as the classification of projective descriptions of P 1 ; in general, the hierarchy of fixed points is conjectured to be isomorphic to the classification of quasihomogeneous singularities. The condition of vanishing first Chern class is an integrality condition on the Virasoro central charge; the central charge is determined by the superpotential. The operator algebra is given by the algebra of Wick contractions of perturbations of the superpotential. (orig.)
Classification of a Supersolid: Trial Wavefunctions, Symmetry Breakings and Excitation Spectra
Chen, Yu; Ye, Jinwu; Tian, Guangshan
2012-11-01
A state of matter is characterized by its symmetry breaking and elementary excitations. A supersolid is a state which breaks both translational symmetry and internal U(1) symmetry. Here, we review some past and recent works in phenomenological Ginsburg-Landau theories, ground state trial wavefunctions and microscopic numerical calculations. We also write down a new effective supersolid Hamiltonian on a lattice. The eigenstates of the Hamiltonian contains both the ground state wavefunction and all the excited states (supersolidon) wavefunctions. We contrast various kinds of supersolids in both continuous systems and on lattices, both condensed matter and cold atom systems. We provide additional new insights in studying their order parameters, symmetry breaking patterns, the excitation spectra and detection methods.
Bourdier, A.
1983-03-01
We present a method which simplifies the investigation of the form of an oblique incident wave on a plasma. The electric field vector of the wave is assumed to be in the plane of incidence. Our method consists in introducing a new frame in which the wave is normally incident. To do so, we use a LORENTZ transformation. This way, we reduce a two-dimensional problem to a one-dimensional one. In the new frame, relativistic terms due to the drift-velocity of the plasma are taken into consideration. The solution we obtain is complementary to GINSBURG's; it is accurate for small angles of incidences. We also describe another resonance taking place at four times the critical density (N 0 = 4 Nsub(c)) [fr
Fleuriet, K Jill
2009-09-01
In this article, I contrast conceptualizations of authoritative knowledge in pregnancy and birth between U.S. midwives and their Mexican immigrant clients at a religious birthing center in south Texas. Although the two groups share certain orientations to pregnancy management, essential differences in prenatal care and birth epistemologies underscore distinct social and economic positions. I use narrative data to document and explain these differences, which throw into relief the hierarchies of identity and need that structure immigrant women's reproductive experiences. Unveiling the different epistemologies can also help to explain sometimes radically divergent ideas that have impacted the very survivability of the birthing center. By focusing on Mexican immigrant women's reproductive decision making in an alternative birthing center, this analysis responds to feminists' call to look to the margins to understand the diversity of women's responses to what Rapp and Ginsburg have called "stratified reproduction".
Classic and quantic interpretation of Doppler effect in a refractive medium
Frank, M.I.
1978-01-01
Ginsburg giving quantum consideration to the Vavilov-Cherenkov effect made an assumption that the emission of a photon corresponds to the momentum Psub(ω) = nhω/c. From here one obtains a correct relationship for the frequency and direction of radiation in the Doppler effect. In the present paper on the basis of the author's data (1942 and 1947) and those of Ginzburg and Eidman the energy of radiation is compared with the work made by the field acting on a moving source of radiation. It is shown that the relatjonship Psub(ω) = nEsub(ω)/c between the total momentum flux and energy must take place without fail. Therefore, it is impossible to say which of the energy-momentum tensor by Minkowski or Abraham is to prefer, since they consider the momentum density and not the total momentum flux. (author)
Theory of fractional quantum hall effect
Kostadinov, I.Z.
1985-08-01
A theory of the Fractional Quantum Hall Effect is constructed based on magnetic flux fractionization, which lead to instability of the system against selfcompression. A theorem is proved stating that arbitrary potentials fail to lift a specific degeneracy of the Landau level. For the case of 1/3 fractional filling a model 3-particles interaction is constructed breaking the symmetry. The rigid 3-particles wave function plays the role of order parameter. In a BCS type of theory the gap in the single particles spectrum is produced by the 3-particles interaction. The mean field critical behaviour and critical parameters are determined as well as the Ginsburg-Landau equation coefficients. The Hall conductivity is calculated from the first principles and its temperature dependence is found. The simultaneous tunnelling of 3,5,7 etc. electrons and quantum interference effects are predicted. (author)
Estudio de la competencia matemática en la infancia
Myriam Ortiz Padilla
2012-01-01
Full Text Available Abstract This research paper presents the results of a research study which was carried out in the Colombian Caribbean Region. The goal of which was to determine the level of Math competence of preschool age children. The aim of the study is to provide elements to develop so that we might improve competence within this education level. This is a cross-sectional study and the sample consisted of 116 children in grade transition in public and private schools from Santa Martha District. The instrument used was “Test of Early Math Ability”, designed by Ginsburg y Baroody, in its Spanish adaptation. The results conclude that the Math competence has developed to a medium level in the searched sample. However, it finds differences in relation to the type of school. Resumen En este artículo de investigación se presentan los resultados de un proceso investigativo que se viene realizando en la región Caribe colombiana, en el cual se busca determinar el nivel de competencia matemática en niños en edad preescolar. Esto con el objetivo de aportar elementos al desarrollo de dicha competencia desde los inicios de la formación académica. En un estudio descriptivo de corte transversal y con una muestra de 116 niños y niñas, se describen así las características de la competencia matemática de la población matriculada en el grado transición de las instituciones públicas y privadas del distrito de Santa Marta. El instrumento utilizado fue el Test de Competencia Matemática Básica, Tema 3, diseñado por Ginsburg y Baroody, en su adaptación española.
Talamo, Alberto [Department of Nuclear and Reactor Physics, Royal Institute of Technology - KTH, Roslagstullsbacken 21, S-10691 Stockholm (Sweden)]. E-mail: alby@anl.gov
2007-01-15
We analytically evaluated the fuel coefficient of temperature both for pebble bed and prismatic high temperature reactors when they utilize as fuel plutonium and minor actinides from light water reactors spent fuel or a mixture of 50% uranium, enriched 20% in {sup 235}U, and 50% thorium. In both cores the calculation involves the evaluation of the resonances integrals of the high absorbers fuel nuclides {sup 240}Pu, {sup 238}U and {sup 232}Th and it requires the esteem of the Dancoff-Ginsburg factor for a pebble bed or prismatic core. The Dancoff-Ginsburg factor represents the only discriminating parameter in the results for the two different reactors types; in fact, both the pebble bed and the prismatic reactors share the same the pseudo-cross-section describing an infinite medium made of graphite filled by TRISO particles. We considered only the resolved resonances with a statistical spin factor equal to one and we took into account 267, 72, 212 resonances in the range 1.057-5692, 6.674-14485, 21.78-3472 eV for {sup 240}Pu, {sup 238}U and {sup 232}Th, respectively, for investigating the influence on the fuel temperature reactivity coefficient of the variation of the TRISO kernel radius and TRISO particles packing fraction from 100, 200 to 300 {mu}m and from 10% to 50%, respectively. Finally, in the pebble bed core, we varied the radius of the pebble for setting a fuel temperature reactivity coefficient similar to the one of a prismatic core.
Morales, J.
2011-12-01
Full Text Available New fossil remains of ruminants from the Lower Miocene (Ramblian, MN3 of the Bardenas Reales (Navarre are studied in this paper. The material, which comprises dentition, is assigned to Andegameryx aff. andegaviensis Ginsburg, 1971. Morphological and metrical similarities exist between these remains and the Spanish population of Andegameryx andegaviensis from Cetina de Aragón (Zaragoza, which is somewhat larger than the French material of this species. However, there are also some affinities with Andegameryx fossils from other Spanish localities as Loranca del Campo (Cuenca. The new material from the Bardenas Reales allows us to confirm certainly the presence of Andegameryx in the area and to provide the evidence that it was a widespread genus of ruminant in Spain during the early Miocene.En este trabajo se describen los nuevos hallazgos de rumiantes fósiles del Mioceno inferior (Rambliense, MN3 de las Bardenas Reales (Navarra. Este material está compuesto por dentición y ha sido clasificado como Andegameryx aff. andegaviensis Ginsburg, 1971. El estudio morfológico y métrico muestra que los restos de las Bardenas son muy semejantes a los de la población española de Andegameryx andegaviensis de Cetina de Aragón (Zaragoza, de talla algo mayor que las poblaciones francesas de esta especie. Sin embargo, también tiene afinidades con material de Andegameryx procedente de otras localidades españolas como Loranca del Campo (Cuenca. Los nuevos hallazgos permiten confirmar sin dudas la presencia de Andegameryx en las Bardenas Reales (Cuenca del Ebro, poniendo de manifiesto que este género de rumiante estuvo ampliamente extendido en las cuencas interiores de España durante el Mioceno inferior.
The parent/child/teacher reading relation
Myrna Machet
2008-08-01
Full Text Available Becoming a reader involves gaining the meaning of the activities involved which includes the purposes, values and roles that are part of the activity. At home literacy is contextualised and a child becomes aware of the uses and practises of reading in his or her culture. This home based literacy is a more natural form of literacy and must be distinguishedfrom school based literacy which is a more organised, systematic literacy. Teachers need to be aware of the important role that preliteracy experience plays in a child's ability to learn to read successfully. They can then provide experiences that will help those children who come to school without the prerequisite emergent literacy skills to become good readers. Teachers will benefit from being aware of family literacy practices and encouraging parents to become involved in their children's reading, because this will help children to make reading and general literacy activities more meaningful. Children who become successful readers associate books with enjoyment and are therefore willing to make the effort to become readers. This is more likely to happen with the support from the family. Research indicates that a key predictor of student success is family involvement in children's education (Ginsburg, 1999:3. Om 'n leser te word, hou in dat betekenis gevorm moet word van die aktiwiteite wat by lees betrokke is, nl die doel, waardes en rolle wat deel van die aktiwiteite. Geletterdheid word by die huis gekontekstualiseer en 'n kind word bewus van die gebruike van en praktyke vir lees in sy of haar kultuur. Hierdie huisgebaseerde geletterdheid is die natuurlikste vorm van geletterdheid en moet onderskei word van skoolgebaseerde geletterdheid wat 'n meer georganiseerde sistematiese soort geletterdheid is. Onderwysers moet bewus wees van die belangrike rol wat voor-geletterdheidervaring speel in In kind se vermoe om suksesvol te leer lees. Hulle kan dan geleenthede organiseer wat daardie kinders
Health care law versus constitutional law.
Hall, Mark A
2013-04-01
National Federation of Independent Business v. Sebelius, the Supreme Court's ruling on the Patient Protection and Affordable Care Act, is a landmark decision - both for constitutional law and for health care law and policy. Others will study its implications for constitutional limits on a range of federal powers beyond health care. This article considers to what extent the decision is also about health care law, properly conceived. Under one view, health care law is the subdiscipline that inquires how courts and government actors take account of the special features of medicine that make legal or policy issues especially problematic - rather than regarding health care delivery and finance more generically, like most any other economic or social enterprise. Viewed this way, the opinions from the Court's conservative justices are mainly about general constitutional law principles. In contrast, Justice Ruth Bader Ginsburg's dissenting opinion for the four more liberal justices is just as much about health care law as it is about constitutional law. Her opinion gives detailed attention to the unique features of health care finance and delivery in order to inform her analysis of constitutional precedents and principles. Thus, the Court's multiple opinions give a vivid depiction of the compelling contrasts between communal versus individualistic conceptions of caring for those in need, and between health care and health insurance as ordinary commodities versus ones that merit special economic, social, and legal status.
Sessler, A.M.
1995-04-01
Since the seminal work by Ginsburg, et at., the subject of giving the Next Linear Collider photon-photon capability, as well as electron-positron capability, has drawn much attention. A 1990 article by V.I. Teinov describes the situation at that time. In March 1994, the first workshop on this subject was held. This report briefly reviews the physics that can be achieved through the photon-photon channel and then focuses on the means of achieving such a collider. Also reviewed is the spectrum of backscattered Compton photons -- the best way of obtaining photons. We emphasize the spectrum actually obtained in a collider with both polarized electrons and photons (peaked at high energy and very different from a Compton spectrum). Luminosity is estimated for the presently considered colliders, and interaction and conversion-point geometries are described. Also specified are laser requirements (such as wavelength, peak power, and average power) and the lasers that might be employed. These include conventional and free-electron lasers. Finally, we describe the R ampersand D necessary to make either of these approaches viable and explore the use of the SLC as a test bed for a photon-photon collider of very high energy
Geochemical mobility and weathering degree of San Felipe deposit in Camagüey, Cuba
Alfonso Chang-Rodríguez
2018-04-01
Full Text Available San Felipe es un yacimiento residual de corteza de intemperismo distintivo por su alto contenido de sílice. El propósito de este trabajo fue determinar los índices de intemperismo y los coeficientes de movilidad geoquímica en la corteza de meteorización. Utilizando los coeficientes de meteorización de Ginsburg (1946 y Rudnik (1966 se calculó la acumulación y extracción de los principales componentes (SiO2, MgO, FeO, Fe2O3, Al2O3. El análisis de los índices de intemperismo y del grado de acumulación-extracción absoluto permitió evaluar la movilidad, distribución y concentración de los elementos y esclarecer el mecanismo de migración y evacuación del níquel. El balance de masas reveló cómo ocurre la reducción de los componentes más móviles (magnesio, sílice y el aumento de los acumulativos (hierro, aluminio hacia arriba en el perfil, evidenciando que el contenido de sílice supera los valores atribuibles a un proceso de meteorización.
Seahorse (Hippocampus reidi) as a bioindicator of crude oil exposure.
Delunardo, Frederico Augusto Cariello; de Carvalho, Luciano Rodrigues; da Silva, Bruno Ferreira; Galão, Michel; Val, Adalberto Luís; Chippari-Gomes, Adriana R
2015-07-01
This study explored the suitability of the seahorse Hippocampus reidi (Ginsburg, 1933) for assessing biomarkers of genotoxic effects and its use as a sentinel organism to detect the effects of acute exposure to petroleum hydrocarbons. Fish were exposed to three concentrations of crude oil (10, 20 and 30 g/kg) for 96 h, and the activity of phase II biotransformation enzyme glutathione S-transferase (GST) was measured. In addition, we performed genotoxicity assays, such as comet assay, micronucleus (MN) test and nuclear abnormalities (NA) induction, on the erythrocytes of the fish species. Our results revealed that the inhibition of hepatic GST activity in H. reidi was dependent on increasing crude oil concentrations. In contrast, an increase in the damage index (DI) and MN frequency were observed with increased crude oil concentrations. These results indicate that the alkaline comet assay and micronucleus test were suitable and useful in the evaluation of the genotoxicity of crude oil, which could improve determinations of the impact of oil spills on fish populations. In addition, H. reidi is a promising "sentinel organism" to detect the genotoxic impact of petroleum hydrocarbons. Copyright © 2015 Elsevier Inc. All rights reserved.
Demonstration of the Kibble-Zurek mechanism in a non-equilibrium phase transition
Patil, Yogesh S.; Cheung, Hil F. H.; Date, Aditya G.; Vengalattore, Mukund
2017-04-01
We describe the experimental realization of a driven-dissipative phase transition (DPT) in a mechanical parametric amplifier and demonstrate key signatures of a critical point in the system, where the susceptibilities and relaxation time scales diverge and coincide with the spontaneous breaking of symmetry and the emergence of macroscopic order. While these observations are reminiscent of equilibrium phase transitions, it is presently an open question whether such DPTs are amenable to the conventional Landau-Ginsburg-Wilson paradigm that relies on concepts of scale invariance and universality - Indeed, recent theoretical work has predicted that DPTs can exhibit phenomenology that departs from these conventional paradigms. By quenching the system past the critical point, we measure the dynamics of the emergent ordered phase and its departure from adiabaticity, and find that our measurements are in excellent agreement with the Kibble-Zurek hypothesis. In addition to validating the KZ mechanism in a DPT for the first time, we also uniquely show that the measured critical exponents accurately reflect the interplay between the intrinsic coherent dynamics and the environmental correlations, with a clear departure from mean field exponents in the case of non-Markovian system-bath interactions. We also discuss how the techniques of reservoir engineering and the imposition of artificial environmental correlations can result in the stabilization of novel many-body quantum phases and exotic non-equilibrium states of matter.
The Kibble-Zurek mechanism in phase transitions of non-equilibrium systems
Cheung, Hil F. H.; Patil, Yogesh S.; Date, Aditya G.; Vengalattore, Mukund
2017-04-01
We experimentally realize a driven-dissipative phase transition using a mechanical parametric amplifier to demonstrate key signatures of a second order phase transition, including a point where the susceptibilities and relaxation time scales diverge, and where the system exhibits a spontaneous breaking of symmetry. Though reminiscent of conventional equilibrium phase transitions, it is unclear if such driven-dissipative phase transitions are amenable to the conventional Landau-Ginsburg-Wilson paradigm, which relies on concepts of scale invariance and universality, and recent work has shown that such phase transitions can indeed lie beyond such conventional universality classes. By quenching the system past the critical point, we investigate the dynamics of the emergent ordered phase and find that our measurements are in excellent agreement with the Kibble-Zurek mechanism. In addition to verifying the Kibble-Zurek hypothesis in driven-dissipative phase transitions for the first time, we also demonstrate that the measured critical exponents accurately reflect the interplay between intrinsic coherent dynamics and environmental correlations, showing a clear departure from mean field exponents in the case of non-Markovian system-bath interactions. We further discuss how reservoir engineering and the imposition of artificial environmental correlations can result in the stabilization of novel many-body quantum phases and aid in the creation of exotic non-equilibrium states of matter.
Gunderson, Elizabeth A; Levine, Susan C
2011-09-01
Before they enter preschool, children vary greatly in their numerical and mathematical knowledge, and this knowledge predicts their achievement throughout elementary school (e.g. Duncan et al., 2007; Ginsburg & Russell, 1981). Therefore, it is critical that we look to the home environment for parental inputs that may lead to these early variations. Recent work has shown that the amount of number talk that parents engage in with their children is robustly related to a critical aspect of mathematical development - cardinal-number knowledge (e.g. knowing that the word 'three' refers to sets of three entities; Levine, Suriyakham, Rowe, Huttenlocher & Gunderson, 2010). The present study characterizes the different types of number talk that parents produce and investigates which types are most predictive of children's later cardinal-number knowledge. We find that parents' number talk involving counting or labeling sets of present, visible objects is related to children's later cardinal-number knowledge, whereas other types of parent number talk are not. In addition, number talk that refers to large sets of present objects (i.e. sets of size 4 to 10 that fall outside children's ability to track individual objects) is more robustly predictive of children's later cardinal-number knowledge than talk about smaller sets. The relation between parents' number talk about large sets of present objects and children's cardinal-number knowledge remains significant even when controlling for factors such as parents' socioeconomic status and other measures of parents' number and non-number talk. © 2011 Blackwell Publishing Ltd.
Structure of the φ photoproduction amplitude at a few GeV
Titov, A.I.; Toki, H.; Titov, A.I.; Streltsova, O.; Lee, T.H.
1999-01-01
The structure of the φ photoproduction amplitude in the √ (s) ∼2-5 GeV region is analyzed based on Pomeron-exchange and meson-exchange mechanisms. The SU(3) symmetry and the φ decay widths are exploited to determine the parameters that are needed to predict the amplitudes due to pseudoscalar mesons (π 0 ,η) exchange, scalar mesons (σ,a 0 ,f 0 ) exchange, and the φ radiation from the nucleon. In addition to the universally accepted Pomeron exchange with an intercept α(0)∼1.08, we investigate the role of a second Pomeron with α(0) π =0 + ,M b 2 ∼3 GeV 2 ) predicted by the lattice QCD calculation and dual Ginsburg-Landau model. It is found that the existing limited data at low energies near threshold can accommodate either the second Pomeron or the scalar mesons exchange. The differences between these two competing mechanisms are shown to have profound effects on various density matrices which can be used to calculate the cross sections as well as various single and double polarization observables. We predict a definite isotopic effect: polarization observables of φ photoproduction on the proton and neutron targets can have differences of a factor 2 and more. copyright 1999 The American Physical Society
Super Picard-Fuchs equation and monodromies for supermanifolds
Kaura, Payal; Misra, Aalok; Shukla, Pramod
2007-01-01
Following, Aganagic and Vafa (e-print hep-th/0403192) and Hori and Vafa (e-print hep-th/0002222), we discuss the Picard-Fuchs equation for the super Landau-Ginsburg mirror to the super Calabi-Yau in WCP (3vertical bar2) [1,1,1,3 vertical bar 1,5] (using techniques of Greene and Lazaroiu [Nucl. Phys. B 604, 181 (2001), e-print hep-th/0001025] and Misra [Fortschr. Phys. 52, 831 (2004), e-print hep-th/0311186]), Meijer basis of solutions, and monodromies (at 0,1 and ∞) in the large and small complex structure limits, as well as obtain the mirror hypersurface, which in the large Kaehler limit turns out to be either a bidegree-(6,6) hypersurface in WCP (3|1) [1,1,1,2]xWCP (1vertical bar1) [1,1 vertical bar 6] or a (Z 2 singular) bidegree-(6,12) hypersurface in WCP (3vertical bar1) [1,1,2,6 vertical bar 6]xWCP (1vertical bar1) [1,1 vertical bar 6
Structure elucidation of a novel oligosaccharide (Medalose) from camel milk
Gangwar, Lata; Singh, Rinku; Deepak, Desh
2018-02-01
Free oligosaccharides are the third most abundant solid component in milk after lactose and lipids. The study of milk oligosaccharides indicate that nutrients are not only benefits the infant's gut but also perform a number of other functions which include stimulation of growth, receptor analogues to inhibit binding of pathogens and substances that promote postnatal brain development. Surveys reveal that camel milk oligosaccharides possess varied biological activities that help in the treatment of diabetes, asthma, anaemia, piles and also a food supplement to milking mothers. In this research, camel milk was selected for its oligosaccharide contents, which was then processed by Kobata and Ginsburg method followed by the HPLC and CC techniques. Structure elucidation of isolated compound was done by the chemical degradation, chemical transformation and comparison of chemical shift of NMR data of natural and acetylated oligosaccharide structure reporter group theory, the 1H, 13C NMR, 2D-NMR (COSY, TOCSY and HSQC) techniques, and mass spectrometry. The structure was elucidated as under: MEDALOSE
Field-theoretic approach to fluctuation effects in neural networks
Buice, Michael A.; Cowan, Jack D.
2007-01-01
A well-defined stochastic theory for neural activity, which permits the calculation of arbitrary statistical moments and equations governing them, is a potentially valuable tool for theoretical neuroscience. We produce such a theory by analyzing the dynamics of neural activity using field theoretic methods for nonequilibrium statistical processes. Assuming that neural network activity is Markovian, we construct the effective spike model, which describes both neural fluctuations and response. This analysis leads to a systematic expansion of corrections to mean field theory, which for the effective spike model is a simple version of the Wilson-Cowan equation. We argue that neural activity governed by this model exhibits a dynamical phase transition which is in the universality class of directed percolation. More general models (which may incorporate refractoriness) can exhibit other universality classes, such as dynamic isotropic percolation. Because of the extremely high connectivity in typical networks, it is expected that higher-order terms in the systematic expansion are small for experimentally accessible measurements, and thus, consistent with measurements in neocortical slice preparations, we expect mean field exponents for the transition. We provide a quantitative criterion for the relative magnitude of each term in the systematic expansion, analogous to the Ginsburg criterion. Experimental identification of dynamic universality classes in vivo is an outstanding and important question for neuroscience
Yang Gang; Yue Zhenxing; Sun Tieyu; Gou Huanlin; Li Longtu
2008-01-01
The dielectric properties of (Nb, Y)-doped BaTiO 3 in a multilayer ceramic capacitor (MLCC) under combined external uniaxial compressive stress and dc bias field were investigated at room temperature by using a modified Ginsburg-Landau-Devonshire thermodynamic theory and the dielectric measurement. It is found that although dc bias decreases the dielectric properties dominantly, the influence of the external uniaixial compressive stress should not be neglected. When applied along a direction perpendicular to the internal electrode layer in the MLCC, the external uniaixal compressive stress will strengthen the negative effect of dc bias. In contrast, the external uniaxial compressive stress along a direction parallel to the internal electrode layer in the MLCC will increase the dielectric permittivity under dc bias field, i.e. improve the ε-V response of the MLCC. Furthermore, although there is a difference between the calculated permittivity and the measured permittivity, the effects of the combined external uniaxial compressive stress and dc bias field on the dielectric permittivity described through two approaches are in good agreement
Random matrix models for phase diagrams
Vanderheyden, B; Jackson, A D
2011-01-01
We describe a random matrix approach that can provide generic and readily soluble mean-field descriptions of the phase diagram for a variety of systems ranging from quantum chromodynamics to high-T c materials. Instead of working from specific models, phase diagrams are constructed by averaging over the ensemble of theories that possesses the relevant symmetries of the problem. Although approximate in nature, this approach has a number of advantages. First, it can be useful in distinguishing generic features from model-dependent details. Second, it can help in understanding the 'minimal' number of symmetry constraints required to reproduce specific phase structures. Third, the robustness of predictions can be checked with respect to variations in the detailed description of the interactions. Finally, near critical points, random matrix models bear strong similarities to Ginsburg-Landau theories with the advantage of additional constraints inherited from the symmetries of the underlying interaction. These constraints can be helpful in ruling out certain topologies in the phase diagram. In this Key Issues Review, we illustrate the basic structure of random matrix models, discuss their strengths and weaknesses, and consider the kinds of system to which they can be applied.
Cláudio Clécio Vidal Eufrausino
2008-06-01
Full Text Available O objetivo deste artigo é discutir a necessidade de repensar o conflito entre disciplinaridade e interdisciplinaridade como se fossem opostos irreconciliáveis. Tentamos demonstrar que a riqueza das ciências humanas cresce através do confronto aberto entre estas duas modalidades de pesquisa, a fim de serem preenchidas as lacunas de ambas. Por meio desta análise, procuramos dar um novo significado para os termos superficialidade e profundidade, tentando superar a antiga oposição que considera profundidade como uma coisa boa em oposição ao caráter superficial. Ao fazermos isto, estamos revendo, com auxílio da teoria de Carlo Ginsburg, a oposição entre retórica e prova, ou, em outros termos, entre factualidade e demonstração argumentativa. Através do enfrentamento dos limites tanto da disciplinaridade quanto da interdisciplinaridade, tentamos apontar novas direções científicas, mostrando soluções marcantes não pelo poder que contêm em si mesmas, mas pela capacidade delas de estimular uma freqüente revisão dos paradigmas das ciências.
Cooper Pair Writing at the LaAlO3/ SrTiO 3 Interface
Cen, Cheng; Bogorin, Daniela F.; Bark, Chung Wung; Folkman, Chad M.; Eom, Chang-Beom; Levy, Jeremy
2011-03-01
Superconducting semiconductors offer unique ways to exert electrostatic control over macroscopic quantum phases. The recently demonstrated nanoscale control over conductivity at the LaAl O3 / SrTi O3 interface raises the question of whether nanoscale control over superconducting phases can be realized. Here we report low-temperature magnetotransport experiments on structures defined with nanoscale precision at the LaAl O3 / SrTi O3 interface. A quantum phase transition is observed that is associated with the formation of Cooper pairs, but a finite resistance is observed at the lowest temperatures. Higher mobility interfaces exhibit larger Ginsburg-Landau coherence lengths, a stronger suppression of pairing by magnetic field as well as Shubnikov-de Haas oscillations. Cooper pair localization, spin-orbit coupling, and finite-size effects may factor into an explanation for some of the unusual properties observed. The work is supported by Department of Energy and State of Florida, NSF (DMR-0906443 and DMR-0704022), DOE (DE-FG02-06ER46327) and the Fine Foundation.
Ginsburg I
2017-02-01
Full Text Available Isaac Ginsburg,1 Peter Vernon van Heerden,2 Erez Koren1 1Institute of Dental Sciences, Faculty of Dental Medicine, The Hebrew University of Jerusalem, 2General Intensive Care Unit, Hadassah University Hospital, Jerusalem, Israel Abstract: This paper describes the evolution of our understanding of the biological role played by synthetic and natural antimicrobial cationic peptides and by the highly basic nuclear histones as modulators of infection, postinfectious sequelae, trauma, and coagulation phenomena. The authors discuss the effects of the synthetic polymers of basic poly α amino acids, poly l-lysine, and poly l-arginine on blood coagulation, fibrinolysis, bacterial killing, and blood vessels; the properties of natural and synthetic antimicrobial cationic peptides as potential replacements or adjuncts to antibiotics; polycations as opsonizing agents promoting endocytosis/phagocytosis; polycations and muramidases as activators of autolytic wall enzymes in bacteria, causing bacteriolysis and tissue damage; and polycations and nuclear histones as potential virulence factors and as markers of sepsis, septic shock, disseminated intravasclar coagulopathy, acute lung injury, pancreatitis, trauma, and other additional clinical disorders Keywords: histones, sepsis, septic shock
Anomaly in the P- and R- branches in the spectra of hydrogen Fulcher band emission
Kado, Shinichiro; Yamasaki, Daisuke; Iida, Yohei; Xiao Bingjia
2004-01-01
Anomalies in the Fulcher-band (d 3 Π u -a 3 Σ g + ) spectra, which are widely used for the purpose of measuring ro-vibronic structure of the hydrogen molecule, are investigated using the hollow cathode glow discharge of 230 V-70 mA at 30 Pa. By making use of the recently developed analyzing scheme and experimentally determined life-time of the state involved, the historical data in the Ginsburg and Dieke's publication are reanalyzed and compared with our present data. Populations of the vibronic state v' ≥ 4 in the Q branch can be corrected to a considerable extend by taking into account the lifetime of the states, while those of any v' in the P and R branches cannot. However, the average values of the upper-Fulcher populations deduced from the P and R branches coincide with those from Q branch by taking into consideration the difference in the excitation from the ground electronic state. (author)
Ferroelectric properties of BaTiO3/PbZr0.2Ti.08O3 bilayer thin film
Salev, Pavel; Yang, Chun; Grigoriev, Alexei
2014-03-01
The thin film ferroelectric BaTiO3/PbZr0.2Ti0.8O3 bilayer was epitaxially grown on SrRuO3/SrTiO3 substrate by RF sputtering. Electrical measurements of polarization switching revealed two different switching regimes - a small ferroelectric hysteresis loop at low applied voltage and a larger loop at a high voltage. The measured dielectric permittivity corresponds to weak electrostatic coupling between two layers according to Landau-Ginsburg-Devonshire theory. This weak coupling may allow for independent polarization states to exist in individual layers. This can lead to stable head-to-head and tail-to-tail polarization domain configurations, which would explain the two switching regimes observed in electrical measurements. The compensation of polarization gradient across the interface can be explained by the enhancement of interface charge carrier density due to strong bending of electron energy bands. This work was supported by NSF award DMR-1057159.
Phonon-induced enhancements of the energy gap and critical current in superconducting aluminum
Seligson, D.
1983-01-01
The enhancement of the energy gap, Δ, and critical current, i/sub c/, in superconducting aluminum thin films were under the influence of 8 to 10 GHz phonons. The phonons were generated by piezoelectric transduction of a 1 kW microwave pulse of about 1 μsec duration. By means of a quartz delay line, the phonons were allowed to enter the aluminum only after the microwaves had long since disappeared. The critical current was measured in long narrow Al strips, in which the current flow is 1-dimensional and well described by Ginsburg-Landau theory. To measure Δ the Al film was used as one electrode in a superconductor-insulator-superconductor tunnel junction whose current-voltage characteristic gave Δ directly. For the measurements of i/sub c/, the total critical current was measured in the presence of the phonon perturbation. For the measurements of Δ the change of Δ away from its equilibrium value was measured. In both cases the first measurements of enhancement of these macroscopic variables under phonon irradiation is reported. The gap-enhancement was found to be in good agreement with theory, but only for relatively and surprisingly low input power. The critical current measurements are predicted to be in rough agreement with the Δ measurements but this was not observed
Type IIA on a compact Calabi-Yau and D=11 supergravity uplift of its orientifold
Misra, A.
2004-01-01
Using the prescription of K. Hori and C. Vafa for defining period integrals in the Landau-Ginsburg theory for compact Calabi-Yau's, we obtain the Picard-Fuchs equation and the Meijer basis of solutions for the compact Calabi-Yau CY 3 (3,243) expressed as a degree-24 Fermat hypersurface after resolution of the orbifold singularities. The importance of the method lies in the ease with which one can consider the large and small complex structure limits, as well as the ability to get the ''ln''-terms in the periods without having to parametrically differentiate infinite series. We consider in detail the evaluation of the monodromy matrix in the large and small complex structure limits. We also consider the action of the freely acting antiholomorphic involution on D=11 supergravity compactified on CY 3 (3,243) x S 1 and obtain the Kaehler potential for the same in the limit of large volume of the Calabi-Yau. As a by-product, we also give a conjecture for the action of the orientation-reversing antiholomorphic involution on the periods, given its action on the cohomology, using a canonical (co)homology basis. Finally, we also consider showing a null superpotential on the orientifold of type IIA on CY 3 (3,243), having taken care of the orbifold singularities. (Abstract Copyright [2004], Wiley Periodicals, Inc.)
Dynamics of an N-vortex state at small distances
Ovchinnikov, Yu. N.
2013-01-01
We investigate the dynamics of a state of N vortices, placed at the initial instant at small distances from some point, close to the “weight center” of vortices. The general solution of the time-dependent Ginsburg-Landau equation for N vortices in a large time interval is found. For N = 2, the position of the “weight center” of two vortices is time independent. For N ≥ 3, the position of the “weight center” weakly depends on time and is located in the range of the order of a 3 , where a is a characteristic distance of a single vortex from the “weight center.” For N = 3, the time evolution of the N-vortex state is fixed by the position of vortices at any time instant and by the values of two small parameters. For N ≥ 4, a new parameter arises in the problem, connected with relative increases in the number of decay modes.
Strange metals and quantum phase transitions from gauge/gravity duality
Liu, Hong
2011-03-01
Metallic materials whose thermodynamic and transport properties differ significantly from those predicted by Fermi liquid theory, so-called non-Fermi liquids, include the strange metal phase of cuprate superconductors, and heavy fermion systems near a quantum phase transition. We use gauge/gravity duality to identify a class of non-Fermi liquids. Their low-energy behavior is governed by a nontrivial infrared fixed point which exhibits non-analytic scaling behavior only in the temporal direction. Some representatives of this class have single-particle spectral functions and transport behavior similar to those of the strange metals, with conductivity inversely proportional to the temperature. Such holographic systems may also exhibit novel ``magnetic instabilities'', where the quantum critical behavior near the transition involves a nontrivial interplay between local and bulk physics, with the local physics again described by a similar infrared fixed point. The resulting quantum phase transitions do not obey the standard Landau-Ginsburg-Wilson paradigm and resemble those of the heavy fermion quantum critical points.
Dynamics of an N-vortex state at small distances
Ovchinnikov, Yu. N., E-mail: ovc@itp.ac.ru [Max-Planck Institute for Physics of Complex Systems (Germany)
2013-01-15
We investigate the dynamics of a state of N vortices, placed at the initial instant at small distances from some point, close to the 'weight center' of vortices. The general solution of the time-dependent Ginsburg-Landau equation for N vortices in a large time interval is found. For N = 2, the position of the 'weight center' of two vortices is time independent. For N {>=} 3, the position of the 'weight center' weakly depends on time and is located in the range of the order of a{sup 3}, where a is a characteristic distance of a single vortex from the 'weight center.' For N = 3, the time evolution of the N-vortex state is fixed by the position of vortices at any time instant and by the values of two small parameters. For N {>=} 4, a new parameter arises in the problem, connected with relative increases in the number of decay modes.
Els media a través de les pràctiques: una aproximació etnogràfica als estudis de comunicació
Elisenda Ardèvol
2009-06-01
Full Text Available La recerca antropològica i etnogràfica dels mitjans de comunicació s'ha centrat en gran part en l'anàlisi de la recepció dels productes dels mitjans tradicionals (televisió, ràdio, premsa escrita i pel·lícules i el consum relacionat amb l'apropiació domèstica de tecnologies (Rothenbuhler et al., 2005. També hi ha un ampli corpus de recerca dedicat a l'estudi de la dimensió política dels mitjans alternatius i indígenes (Ginsburg et al., 2002. Tanmateix, hi ha hagut una separació entre els estudis dels media i els estudis d'internet, i entre l'anàlisi de la recepció i les pràctiques d'autoproducció, com ara la fotografia familiar o el vídeo domèstic. Les pràctiques actuals en relació amb els mitjans digitals insten a reexaminar els continguts i els fluxos d'autoproducció amb una perspectiva més àmplia que difumina la frontera entre el que és públic i el que és privat, productes realitzats per corporacions i productes amateurs, producció domèstica i indústria cultural, activisme polític i vida quotidiana.
F-theory and 2d (0,2) theories
Schäfer-Nameki, Sakura [Department of Mathematics, King’s College London, The Strand, London WC2R 2LS (United Kingdom); Weigand, Timo [Institut für Theoretische Physik, Ruprecht-Karls-Universität,Philosophenweg 19, 69120 Heidelberg (Germany)
2016-05-11
F-theory compactified on singular, elliptically fibered Calabi-Yau five-folds gives rise to two-dimensional gauge theories preserving N=(0,2) supersymmetry. In this paper we initiate the study of such compactifications and determine the dictionary between the geometric data of the elliptic fibration and the 2d gauge theory such as the matter content in terms of (0,2) superfields and their supersymmetric couplings. We study this setup both from a gauge-theoretic point of view, in terms of the partially twisted 7-brane theory, and provide a global geometric description based on the structure of the elliptic fibration and its singularities. Global consistency conditions are determined and checked against the dual M-theory compactification to one dimension. This includes a discussion of gauge anomalies, the structure of the Green-Schwarz terms and the Chern-Simons couplings in the dual M-theory supersymmetric quantum mechanics. Furthermore, by interpreting the resulting 2d (0,2) theories as heterotic worldsheet theories, we propose a correspondence between the geometric data of elliptically fibered Calabi-Yau five-folds and the target space of a heterotic gauged linear sigma-model (GLSM). In particular the correspondence between the Landau-Ginsburg and sigma-model phase of a 2d (0,2) GLSM is realized via different T-branes or gluing data in F-theory.
Critical fields in high temperature superconductors
Finnemore, D.K.
1991-01-01
An analysis of various methods to obtain the critical fields of the high temperature superconductors from experimental data is undertaken in order to find definitions of these variables that are consistent with the models used to define them. Characteristic critical fields of H c1 , H c2 and H c that occur in the Ginsburg-Landau theory are difficult to determine experimentally in the high temperature superconductors because there are additional physical phenomena that obscure the results. The lower critical field is difficult to measure because there are flux pinning and surface barrier effects to flux entry; the upper critical field is difficult because fluctuation effects are large at this phase boundary; the thermodynamic critical field is difficult because fluctuations make it difficult to know the field where the magnetization integral should be terminated. In addition to these critical fields there are at least two other cross-over fields. There is the so called irreversibility line where the vortices transform from a rigid flux line lattice to a fluid lattice and there is a second cross-over field associated with the transition from the fluctuation to the Abrikosov vortex regime. The presence of these new physical effects may require new vocabulary
Adam John Rock
2016-03-01
Full Text Available Generally, academic psychologists are mindful of the fact that, for many students, the study of research methods and statistics is anxiety provoking (Gal, Ginsburg, & Schau, 1997. Given the ubiquitous and distributed nature of eLearning systems (Nof, Ceroni, Jeong, & Moghaddam, 2015, teachers of research methods and statistics need to cultivate an understanding of how to effectively use eLearning tools to inspire psychology students to learn. Consequently, the aim of the present paper is to discuss critically how using eLearning systems might engage psychology students in research methods and statistics. First, we critically appraise definitions of eLearning. Second, we examine numerous important pedagogical principles associated with effectively teaching research methods and statistics using eLearning systems. Subsequently, we provide practical examples of our own eLearning-based class activities designed to engage psychology students to learn statistical concepts such as Factor Analysis and Discriminant Function Analysis. Finally, we discuss general trends in eLearning and possible futures that are pertinent to teachers of research methods and statistics in psychology.
Paradigm lost: provider concentration and the failure of market theory.
Vladeck, Bruce C
2014-06-01
In classic market theory, increased concentration among providers leads to higher prices for consumers. In the world of contemporary health policy, many stakeholders echo the classic market theory, blaming high health care prices on the increased concentration of providers, such as occurs when hospitals merge or are acquired by other hospitals. Thus, the consolidation of providers has become a convenient target for policy makers who want to be viewed as actively pursuing solutions to the growth in health care spending. Yet many of the factors fueling increased provider concentration are widely believed to be desirable, or practically unavoidable. Meanwhile, health care prices are increasing at historically low levels. Thus, there appears to be a contradiction between efforts to contain health care prices and the fact that aggressive policies aimed at reducing provider concentration might be ineffective and could even have the unintended effect of stunting positive developments. In a group of Health Affairs articles, William Sage and Paul Ginsburg and Gregory Pawlson respond to this conundrum by proposing a range of policy alternatives that, in this author's opinion, are either impractical or counterproductive because they have their roots in classical economic models of an industry with pervasive market failure. More effective and practical responses may be less theoretically elegant but more realistic and more reasonable. Project HOPE—The People-to-People Health Foundation, Inc.
Monopoles and confinement in lattice gauge theory
Singh, V.
1992-01-01
The mechanism by which quarks, believed to be the fundamental constituents of matter, are prevented from existing in the free state is fundamental problems in physics. One of the most viable candidates for a hypothesis of confinement is the dual superconductor mechanism that likens quark confinement to the Meissner effect in superconductors. The peculiarities of quark interactions make a numerical approach to the subject a necessity, and therefore, much of the work in this area has been done through the methods of lattice gauge theory, with the simplicities afforded by putting spacetime on a four-dimensional grid. Over the years a large amount of indirect evidence has accumulated that the dual superconductor hypothesis does indeed lead to quark confinement but unambiguous evidence has eluded research efforts until recently. This work presents the first direct proof of a Meissner-like effect that leads to confinement, using the numerical techniques of lattice gauge theory. It is shown that for a U(1) lattice gauge theory, that serves as a toy model of the real world of quarks, a dual London relation and an electric fluxoid qauntization condition is satisfied, allowing the author to conclude that the vacuum in this case acts like an extreme type-II superconductor, and that quarks are confined. The author also shows that SU(2) lattice gauge theory, which is qualitatively different and another step closer to reality, shows a Meissner-like effect. In contrast to the U(1) case, the author's results are found consistent with a dual version of the Ginsburg-Landau theory of superconductor on the borderline between type-I and type-II. This approach paves the wave for a study of the more complicated theory, quantum chromodynamics, that is believed to describe quarks
Scheidt, E-W; Hauf, C; Reiner, F; Eickerling, G; Scherer, W, E-mail: Ernst-Wilhelm.Scheidt@physik.uni-augsburg.de [CPM, Institut fuer Physik, Universitaet Augsburg, 86159 Augsburg (Germany)
2011-01-01
The transition metal carbide Sc{sub 3}CoC{sub 4} consists of a quasi-one-dimensional (1D) structure with [CoC{sub 4}]{sub {infinity}} polyanionic chains embedded in a scandium matrix. At ambient temperatures Sc{sub 3}CoC{sub 4} displays metallic behavior. At lower temperatures, however, charge density wave formation has been observed around 143 K which is followed by a structural phase transition at 72 K. Below T{sub c}{sup onset} = 4.5 K the polycrystalline sample becomes superconductive. From H{sub c1}(0) and H{sub c2}(0) values we could estimate the London penetration depth ({lambda}{sub L} {approx_equal} 9750 A) and the Ginsburg-Landau (GL) coherence length ({xi}{sub GL} {approx_equal} 187 A). The resulting GL-parameter ({kappa} {approx_equal} 52) classifies Sc{sub 3}CoC{sub 4} as a type II superconductor. Here we compare the puzzling superconducting features of Sc{sub 3}CoC{sub 4}, such as the unusual temperature dependence i) of the specific heat anomaly and ii) of the upper critical field H{sub c2}(T) at T{sub c}, and iii) the magnetic hysteresis curve, with various related low dimensional superconductors: e.g., the quasi-1D superconductor (SN){sub x} or the 2D transition-metal dichalcogenides. Our results identify Sc{sub 3}CoC{sub 4} as a new candidate for a quasi-1D superconductor.
The June surprises: balls, strikes, and the fog of war.
Fried, Charles
2013-04-01
At first, few constitutional experts took seriously the argument that the Patient Protection and Affordable Care Act exceeded Congress's power under the commerce clause. The highly political opinions of two federal district judges - carefully chosen by challenging plaintiffs - of no particular distinction did not shake that confidence that the act was constitutional. This disdain for the challengers' arguments was only confirmed when the act was upheld by two highly respected conservative court of appeals judges in two separate circuits. But after the hostile, even mocking questioning of the government's advocate in the Supreme Court by the five Republican-appointed justices, the expectation was that the act would indeed be struck down on that ground. So it came as no surprise when the five opined the act did indeed exceed Congress's commerce clause power. But it came as a great surprise when Chief Justice John Roberts, joined by the four Democrat-appointed justices, ruled that the act could be sustained as an exercise of Congress's taxing power - a ground urged by the government almost as an afterthought. It was further surprising, even shocking, that Justices Antonin Scalia, Anthony Kennedy, Clarence Thomas, and Samuel Alito not only wrote a joint opinion on the commerce clause virtually identical to that of their chief, but that in writing it they did not refer to or even acknowledge his opinion. Finally surprising was the fact that Justices Ruth Bader Ginsburg and Stephen Breyer joined the chief in holding that aspects of the act's Medicaid expansion were unconstitutional. This essay ponders and tries to unravel some of these puzzles.
Miczek, Klaus A; Nikulina, Ella M; Takahashi, Aki; Covington, Herbert E; Yap, Jasmine J; Boyson, Christopher O; Shimamoto, Akiko; de Almeida, Rosa M M
2011-11-01
In this review, we examine how experiences in social confrontations alter gene expression in mesocorticolimbic cells. The focus is on the target of attack and threat due to the prominent role of social defeat stress in the study of coping mechanisms and victimization. The initial operational definition of the socially defeated mouse by Ginsburg and Allee (1942) enabled the characterization of key endocrine, cardiovascular, and metabolic events during the initial response to an aggressive opponent and during the ensuing adaptations. Brief episodes of social defeat stress induce an augmented response to stimulant challenge as reflected by increased locomotion and increased extracellular dopamine (DA) in the nucleus accumbens (NAC). Cells in the ventral tegmental area (VTA) that project to the NAC were more active as indicated by increased expression of c-fos and Fos-immunoreactivity and BDNF. Intermittent episodes of social defeat stress result in increased mRNA for MOR in brainstem and limbic structures. These behavioral and neurobiological indices of sensitization persist for several months after the stress experience. The episodically defeated rats also self-administered intravenous cocaine during continuous access for 24 h ("binge"). By contrast, continuous social stress, particularly in the form of social subordination stress, leads to reduced appetite, compromised endocrine activities, and cardiovascular and metabolic abnormalities, and prefer sweets less as index of anhedonia. Cocaine challenges in subordinate rats result in a blunted psychomotor stimulant response and a reduced DA release in NAC. Subordinate rats self-administer cocaine less during continuous access conditions. These contrasting patterns of social stress result from continuous vs. intermittent exposure to social stress, suggesting divergent neuroadaptations for increased vulnerability to cocaine self-administration vs. deteriorated reward mechanisms characteristic of depressive-like profiles.
Motivational readiness of children to school in nuclear and single parent families
Kateryna Ostrovska
2015-12-01
Full Text Available The aim of the paper is a comparison of psychological readiness of the child to go to school in nuclear and single parent families. To obtain the objectives of the paper the following methods were used: 1 methods “Two schools” by L.A Venger to identify the level of formation of internal position of the student; 2 the method “Motivational research studies in older preschoolers” by M.R. Ginsburg; 3 method “Pattern” by L.I. Tsehanskaya to determine the degree of development of skills training activities; 4 method “Graphic dictation” by D. El’konin to study the ability to follow adult instructions. The investigated group consisted of 40 students from first grade secondary school - 20 students from nuclear families (12 girls and 8 boys and 20 students from single parent families (9 girls and 11 boys. As a result of qualitative, comparative and correlation analysis it was shown that readiness of children to go to school susbstantially depends on completness of their families. The children from families have a higher level of skill training and internal position than children from single parent families. This occurs because both parents pay more attention to the children in the forming of a willingness to learn in school. The studies have shown that in the group of children from nuclear families dominate the highest level of development of skills training activities, increased formation of internal positions and childrens social motivation. These indicators are the hallmarks of readiness to learn at school. Also, some recommendations to teachers are provided as for increase of motivation to learn in children from single parent families.
P. K. Maheshwari
2015-09-01
Full Text Available We report successful growth of flux free large single crystals of superconducting FeSe1/2Te1/2 with typical dimensions of up to few cm. The AC and DC magnetic measurements revealed the superconducting transition temperature (Tc value of around 11.5K and the isothermal MH showed typical type-II superconducting behavior. The lower critical field (Hc1 being estimated by measuring the low field isothermal magnetization in superconducting regime is found to be above 200Oe at 0K. The temperature dependent electrical resistivity ρ(T showed the Tc (onset to be 14K and the Tc(ρ = 0 at 11.5K. The electrical resistivity under various magnetic fields i.e., ρ(TH for H//ab and H//c demonstrated the difference in the width of Tc with applied field of 14Tesla to be nearly 2K, confirming the anisotropic nature of superconductivity. The upper critical and irreversibility fields at absolute zero temperature i.e., Hc2(0 and Hirr(0 being determined by the conventional one-band Werthamer–Helfand–Hohenberg (WHH equation for the criteria of normal state resistivity (ρn falling to 90% (onset, and 10% (offset is 76.9Tesla, and 37.45Tesla respectively, for H//c and 135.4Tesla, and 71.41Tesla respectively, for H//ab. The coherence length at the zero temperature is estimated to be above 20Å ´ by using the Ginsburg-Landau theory. The activation energy for the FeSe1/2Te1/2 in both directions H//c and H//ab is determined by using Thermally Activation Flux Flow (TAFF model.
Kuffner, I.B.; Hickey, T.D.; Morrison, J.M.
2013-01-01
Coral reefs are degrading on a global scale, and rates of reef-organism calcification are predicted to decline due to ocean warming and acidification. Systematic measurements of calcification over space and time are necessary to detect change resulting from environmental stressors. We established a network of calcification monitoring stations at four managed reefs along the outer Florida Keys Reef Tract (FKRT) from Miami to the Dry Tortugas. Eighty colonies (in two sequential sets of 40) of the reef-building coral, Siderastrea siderea, were transplanted to fixed apparatus that allowed repetitive detachment for buoyant weighing every 6 months. Algal-recruitment tiles were also deployed during each weighing interval to measure net calcification of the crustose coralline algal (CCA) community. Coral-calcification rates were an order of magnitude greater than those of CCA. Rates of coral calcification were seasonal (summer calcification was 53% greater than winter), and corals in the Dry Tortugas calcified 48% faster than those at the other three sites. Linear extension rates were also highest in the Dry Tortugas, whereas percent area of the coral skeletons excavated by bioeroding fauna was lowest. The spatial patterns in net coral calcification revealed here correlate well with Holocene reef thickness along the FKRT and, in part, support the “inimical waters hypothesis” proposed by Ginsburg, Hudson, and Shinn almost 50 yrs ago to explain reef development in this region. Due to the homogeneity in coral-calcification rates among the three main Keys sites, we recommend refinement of this hypothesis and suggest that water-quality variables (e.g., carbonate mineral saturation state, dissolved and particulate organic matter, light attenuation) be monitored alongside calcification in future studies. Our results demonstrate that our calcification monitoring network presents a feasible and worthwhile approach to quantifying potential impacts of ocean acidification
Maneiras criativas de não gostar de Bakhtin: Lydia Ginzburg e Mikhail Gasparov
Caryl Emerson
2015-11-01
Full Text Available Este artigo contribui para nossa compreensão de como os russos receberam os conceitos de Bakhtin, principalmente dois influentes estudiosos russos, críticos de Bakhtin, cada um a partir de uma perspectiva diferente. O estudo de tais críticas é valioso, uma vez que nos incentiva a reexaminar nossas próprias percepções, por vezes complacentes, das teorias de Bakhtin. Mikhail Gasparov (1937-2005, um importante classicista e preeminente erudito do verso, publicou críticas virulentas contra Bakhtin entre 1979 e 2004. Seu problema com Bakhtin era essencialmente metodológico. Lydia Ginzburg (1902-1990, conhecida por suas Notes of a Blockade Person, e por estudos sobre os gêneros do diário, das memórias, da carta pessoal e do caderno do escritor, questionou os pressupostos psicológicos por trás das teorias bakhtinianas de simpatia e amor. Ginzburg também tinha sérias dúvidas quanto à ideia bakhtiniana do romance polifônico e a respeito do uso que Bakhtin fazia da oposição entre o monológico e o dialógico para caracterizar os romances de Tolstoi e Dostoiévski. Um exame atento das posições de Bakhtin e Ginzburg sobre o amor revela paralelos e diferenças interessantes. O artigo termina com sugestões sobre como as críticas de Ginsburg e de Gasparov podem nos ajudar a ler Bakhtin de maneiras criativas.
The instability of nonlinear surface waves in an electrified liquid jet
Moatimid, Galal M
2009-01-01
We investigate the weakly nonlinear stability of surface waves of a liquid jet. In this work, the liquids are uniformly streaming through two porous media and the gravitational effects are neglected. The system is acted upon by a uniform tangential electric field, that is parallel to the jet axis. The equations of motion are linearly treated and solved in the light of nonlinear boundary conditions. Therefore, the boundary-value problem leads to a nonlinear characteristic second-order differential equation. This characterized equation has a complex nature. The nonlinearity is kept up to the third degree. It is used to judge the behavior of the surface evolution. According to the linear stability theory, we derive the dispersion relation that accounts for the growth waves. The stability criterion is discussed analytically and a stability picture is identified for a chosen sample system. Several special cases are recovered upon appropriate data choices. In order to derive the Ginsburg-Landau equation for the general case, in the nonlinear approach, we used the method of multiple timescales with the aid of the Taylor expansion. This equation describes the competition between nonlinearity and the linear dispersion relation. As a special case for non-porous media where there is no streaming, we obtained the well-known nonlinear Schroedinger equation as it has been derived by others. The stability criteria are expressed theoretically in terms of various parameters of the problem. Stability diagrams are obtained for a set of physical parameters. We found new instability regions in the parameter space. These regions are due to the nonlinear effects.
Kuffner, I. B.; Hickey, T. D.; Morrison, J. M.
2013-12-01
Coral reefs are degrading on a global scale, and rates of reef-organism calcification are predicted to decline due to ocean warming and acidification. Systematic measurements of calcification over space and time are necessary to detect change resulting from environmental stressors. We established a network of calcification monitoring stations at four managed reefs along the outer Florida Keys Reef Tract (FKRT) from Miami to the Dry Tortugas. Eighty colonies (in two sequential sets of 40) of the reef-building coral, Siderastrea siderea, were transplanted to fixed apparatus that allowed repetitive detachment for buoyant weighing every 6 months. Algal-recruitment tiles were also deployed during each weighing interval to measure net calcification of the crustose coralline algal (CCA) community. Coral-calcification rates were an order of magnitude greater than those of CCA. Rates of coral calcification were seasonal (summer calcification was 53 % greater than winter), and corals in the Dry Tortugas calcified 48 % faster than those at the other three sites. Linear extension rates were also highest in the Dry Tortugas, whereas percent area of the coral skeletons excavated by bioeroding fauna was lowest. The spatial patterns in net coral calcification revealed here correlate well with Holocene reef thickness along the FKRT and, in part, support the "inimical waters hypothesis" proposed by Ginsburg, Hudson, and Shinn almost 50 yrs ago to explain reef development in this region. Due to the homogeneity in coral-calcification rates among the three main Keys sites, we recommend refinement of this hypothesis and suggest that water-quality variables (e.g., carbonate mineral saturation state, dissolved and particulate organic matter, light attenuation) be monitored alongside calcification in future studies. Our results demonstrate that our calcification monitoring network presents a feasible and worthwhile approach to quantifying potential impacts of ocean acidification, warming
León, Ricardo; Somoza, Luis; Medialdea, Teresa; Maestro, Adolfo; Díaz-del-Río, Victor; Fernández-Puga, María del Carmen
2006-06-01
Based on recently gathered swath-bathymetry, high- to ultra-high-resolution seismic, and underwater camera data, along with dredging and coring samples, this paper examines the relationship between sea-floor features and the nature of hydrocarbon-enriched fluid and gas leaks from degassing of deeply buried sediments along the continental margin of the Gulf of Cádiz (eastern Central Atlantic). A classification into three main groups is proposed on the basis of the morphology and nature of deposits: (1) mud volcanoes, (2) methane-derived authigenic carbonates (MDAC) mounds, and (3) crater-like pockmarks. Mud volcanoes are, topographically, cone-shaped sea-floor edifices, built up from catastrophic mud and fluid degassing, intercalated with periods of inactivity. So far more than 25 mud volcanoes have been discovered in the Gulf of Cádiz, named in memory of deceased colleagues (e.g., Ginsburg and Baraza), or researchers' birth places (e.g. Faro, Cibeles, Almazán, San Petersburgh, Yuma, Rabat, Bonjardim, Coruña, Gades). These structures range from 800 to 2500 m in diameter and tower 150-300 m above the seabed. The volcanoes consistently feature a well-defined outer ring or circular terrace and an inner dome. All mud volcanoes are built up of episodes of mud-breccia flows, intercalated with deep-current deposits, with evident indications of gas saturation: degassing structures, a strong H 2S smell, and chemosynthetic fauna (such as Pogonophora sp. tube worms and Calyptogena sp.). Commonly observed carbonate crusts and slabs overlying some mud volcanoes are thought to have been formed by slow, diffuse venting during periods of inactivity or slower rates of fluid venting following the ejection of mud. A "fermentation" process, the result of microbial-mediated oxidation of hydrocarbon-enriched fluids, seems to play an important role in the growth of large deep-water carbonate mounds and chimneys during periods of low methane-seep fluid pressure. More than 400 crater
Gonzalez, Eliseo A.
Fostering resiliency and educational success in students that are faced with adversity is not a simple task. The gap in educational success and achievement among low-income, first generation, traditionally marginalized students continues to be significant. California's educational system needs to stop the hemorrhaging from its educational pipeline, also known as the P-20 pipeline, of all students, especially those groups of students with larger gaps in educational attainment. One potential path towards fixing California's educational pipeline for all students is to form and keep partnerships with programs such as Upward Bound, AVID, and Math Engineering Science Achievement (MESA). In 2010-11, the California Department of Education (CDE) reported that over 51% of students enrolled in California's school system and 51% of all California high school seniors were Latino were Latino. Of the 231,231 Latino high school seniors, 79%, graduated. However, of those that graduated, only 26%, met University of California/California State University (UC/CSU) college entrance requirements. Even though 79% of Latinos graduated, 74% did not qualify to apply to a UC or CSU. If the majority of Latino students continue to fall through holes in the educational pipeline, companies will continue to look abroad to fill STEM jobs that remain unfilled by American workers (California Department of Education [CDE], 2012). Alongside the U.S.'s current economic woes, the lack of college preparedness and knowledge by parents and students has led to a decrease in first generation, low-income Latino students' higher education enrollment (Camacho & Lord, 2011). With strong and positive leadership from family, supplemented by the MESA program, these youths can exert their resiliency, face adversity, and overcome extraordinary barriers. Leaders in education such as teachers, coordinators, advisers, administrators, and parents are in the best position to teach students about resilience (Ginsburg, 2007
Schofield, P.J.
2003-01-01
Herein I compare the relative importance of preference for structurally complex habitat against avoidance of competitors and predators in two benthic fishes common in the Gulf of Mexico. The code goby Gobiosoma robustum Ginsburg and clown goby Microgobius gulosus (Girard) are common, ecologically similar fishes found throughout the Gulf of Mexico and in the southeastern Atlantic Ocean. In Florida Bay, these fishes exhibit habitat partitioning: G. robustum is most abundant in seagrass-dominated areas while M. gulosus is most abundant in sparsely vegetated habitats. In a small-scale field survey, I documented the microhabitat use of these species where their distributions overlap. In a series of laboratory experiments, I presented each species with structured (artificial seagrass) versus nonstructured (bare sand) habitats and measured their frequency of choosing either habitat type. I then examined the use of structured versus nonstructured habitats when the two species were placed together in a mixed group. Finally, I placed a predator (Opsanus beta) in the experimental aquaria to determine how its presence influenced habitat selection. In the field, G. robustum was more abundant in seagrass and M. gulosus was more abundant in bare mud. In the laboratory, both species selected grass over sand in allopatry. However, in sympatry, M. gulosus occupied sand more often when paired with G. robustum than when alone. G. robustum appears to directly influence the habitat choice of M. gulosus: It seems that M. gulosus is pushed out of the structured habitat that is the preferred habitat of G. robustum. Thus, competition appears to modify the habitat selection of these species when they occur in sympatry. Additionally, the presence of the toadfish was a sufficient stimulus to provoke both M. gulosus and G. robustum to increase their selection for sand (compared to single-species treatments). Distribution patterns of M. gulosus and G. robustum
Soemarsaid Moertono
1969-07-01
Full Text Available - D. van der Horst, Albert Herrmann, An historical atlas of China. New edition by Norton Ginsburg. Djambatan N.V., Amsterdam 1966. 88 pp. - A.F.P. Hulsewé, F.S. Drake, Symposium of historical, archaeological and linguistic studies on Southern China, South-East Asia and the Hongkong region. Proceedings of a meeting held in September 1961 as part of the Golden Jubilee Congress of the University of Hongkong. Hongkong, Hongkong University Press, 1967. X + 370 pp. - D.R. Jonker, Liu Shih-Shun, One hundred and one Chinese poems. With English translations and preface. UNESCO Collection of Representative Works, Chinese Series; Hong Kong University Press, 1967. XXXIX + 173 pp. - M.A.P. Meilink-Roelofsz, A. Das Gupta, Malabar in Asian trade 1740-1800. Cambridge South Asian Studies. Cambridge U.P. 1967. XII, 204 blz. Met krt. - C.R. Hooijer, Per Sorensen, Ban-Kao, Neolithic settlements with cemeteries in the Kanchanaburi Province. 140 pp., 140 plates, 4 maps, figs. The Thai-Danish Prehistoric Expedition 1960-62, Archaeological Excavations in Thailand, Vol. II. Munksgaard, Copenhagen, 1967. - C.R. Hooijer, H.R. van Heekeren, Sai-Yok, Stone-age settlements in the Kanchanaburi Province. 129 pp., 33 plates, 47 figs. The Thai-Danish Prehistoric Expedition 1960-1962, Archaeological Excavations in Thailand, Vol. I. Munksgaard, Copenhagen, 1967., Eigil Knuth (eds. - Th. G. Th. Pigeaud, C. Hooykaas, Bagus Umbara, Prince of Koripan. The story of a prince of Bali and a princess of Java, illustrated on palm leaves by a Balines artist. With Balinese text and English translation by Dr C. Hooykaas, Reader in Old Javanese, University of London. Published by the Trustees of the British Museum, London, 1968. 55 pp., 9 illustrations, 31 x 25 cm. - H.J. de Graaf, Soemarsaid Moertono, State and statecraft in old Java: A study of the late Mataram period 16th to 19th century. Monograph series Modern Indonesia Project. Southeast Asia Program Department of Asian Studies. Cornell
Texturing of sodium bismuth titanate-barium titanate ceramics by templated grain growth
Yilmaz, Huseyin
2002-01-01
crystal data. However, the complete polarization, dielectric, and piezoelectric tensors are not available for NBT-BT single crystals. Therefore, the properties of lead based (PZT, 52/48) rhombohedral ferroelectric single domain-single crystals, whose properties (polarization, dielectric and piezoelectric) were computed using Landau-Ginsburg-Devonshire phenomenological theory (by Haun et. al.), were used in the calculations for random and textured cases. (Abstract shortened by UMI.)
Research of the state of the stress-realizing systems in pregnant women with miscarriage
V. A. Plotnik
2013-06-01
Full Text Available Introduction. Miscarriage or spontaneous abortion is the spontaneous end of a pregnancy at a stage where the embryo or fetus is incapable of surviving independently, within the time limit to 22 weeks. Unfortunately, the incidence of abortion in Ukraine remains quite high and ranges from 15 to 23% of all reported pregnancies, while over 92% of them occurred before 12 weeks (Ventskivskyy BM, 2004, Ginsburg V., 2003, Beetle C.I., 2000. The hypothesis of the development of spontaneous miscarriage as a result of the impact of mental stress factors C.T. Javert first proposed back in 1954. Later it was shown that biochemical substances (epinephrine, norepinephrine, oxytocin, prostaglandins are involved in the processes of influence of stressfactors on pregnant women. The aim of the work was to investigate some stress-realizing systems by adopting an integrated approach in women with threatened abortion for further development of the algorithm of the evaluation and prediction of risk of the miscarriage, which will contribute to the reduction of perinatal losses and improve the reproductive health of women. Materials and methods. Study involved 34 pregnant women with diagnosis of "threatened abortion" gestational age from 7 to20 weeks with a singleton pregnancy. The control group consisted of 15 women with usual pregnancy. Was used an integrated approach, consisting of a set of methods for studying the autonomic nervous system using computer cardiointervalography, rheovasography, research levels of hormones such as cortisol, insulin, dehydroepiandrosteronesulfate, progesterone, estradiol, and clinical and laboratory parameters. Results. According to the gynecological, obstetric and physical anamnesis any significant difference between the women of the 1st and 2nd groups were not found. In the study were found that in the main group cortisol levels were significantly (p ≤ 0,01 elevated and index ratio of cortisol and insulin was higher almost in 2 times
Cho AH
2012-01-01
Full Text Available Alex H Cho1, Xiaolei Jiang2, Devin M Mann3, Kensaku Kawamoto4, Timothy J Robinson5, Nancy Wang6, Jeanette J McCarthy2, Mark Woodward7, Geoffrey S Ginsburg1,21Center for Personalized Medicine and Department of Medicine, Duke University, Durham, NC, 2Institute for Genome Sciences and Policy, Duke University, Durham, NC, 3Section of Preventive Medicine and Epidemiology, Department of Medicine, Boston University School of Medicine, Boston, MA, 4Department of Biomedical Informatics, University of Utah, Salt Lake City, UT, 5Medical College of Virginia, Richmond, VA, 6School of Medicine, University of North Carolina-Chapel Hill, Chapel Hill, NC, USA; 7George Institute for Global Health and University of Sydney, AustraliaBackground: Comparative effectiveness research and research in genomic medicine are not orthogonal pursuits. Both require a robust evidence base, and each stands to benefit from applying the methods of the other. There is an exponentially growing literature reporting associations between single nucleotide polymorphisms (SNPs and increased risk for diseases such as type 2 diabetes. Literature-based meta-analysis is an important method of assessing the validity of published gene-disease associations, but a traditional emphasis on exhaustiveness makes it difficult to study multiple polymorphisms efficiently. Here we describe a novel two-step search method for broadly yet systematically reviewing the literature to identify the "most-studied" gene-disease associations, thereby selecting those with a high possibility of replication on which to conduct abbreviated, simultaneous meta-analyses. This method was then applied to identify and evaluate the validity of SNPs reported to be associated with increased type 2 diabetes risk, to demonstrate proof of principle.Methods: A two-step MEDLINE search (1950 to present was conducted in September 2007 for published genetic association data related to SNPs associated with risk of type 2 diabetes. The