bluuebunny/crossref_metadata_2025 huggingface dataset:
Comparison of Snowmelt Infiltration under Different Soil‐Freezing Conditions Influenced by Snow Cover
Authors: Iwata Yukiyoshi , Hayashi Masaki , Hirota Tomoyoshi
Published: January 2008

The depth of soil frost is decreasing in cold regions around the world as a result of climate warming. To evaluate the potential impacts of the reduction in frost depth on the hydrologic cycle, it is necessary to understand snowmelt infiltration processes in frozen soils. A field study was conducted at an agricultural site characterized by volcanic ash soil in Tokachi, Hokkaido, Japan, where frost depths have decreased significantly in the last 20 yr. Soil temperature, water content, matric potential, snow cover, and meteorological parameters were monitored to quantify snowmelt infiltration flux for four winters that had different snow and soil conditions. When snowmelt began, the soil frost was 0.1 to 0.2 m thick in two winters and was absent in two other winters, providing a unique opportunity to compare snowmelt infiltration under frozen and unfrozen conditions. Most of the snowmelt water infiltrated into the soil under both frozen and unfrozen conditions, indicating that the frozen soil layer did not impede infiltration. The lack of flow impedance in the frozen soil was partly due to relatively high air temperature and an absence of freeze‐back events during the snowmelt period. Furthermore, the temperature of the frozen soil layer was close to 0°C when the melt started, meaning that very little meltwater refroze in the soil before the temperature reached 0°C. The thick (>1 m) snow cover insulated the soil surface, allowing the frozen soil layer to warm up with the upward conduction of heat from the unfrozen layer below. These results indicate the importance of the interaction between snow cover and soil, which can be significantly affected by climate change.
Performance Evaluation of Models That Describe the Soil Water Retention Curve between Saturation and Oven Dryness
Authors: Khlosi Muhammed , Cornelis Wim M. , Douaik Ahmed , van Genuchten Martinus Th. , Gabriels Donald
Published: January 2008

The objective of this work was to evaluate eight closed‐form unimodal analytical expressions that describe the soil‐water retention curve across the complete range of soil water contents. To meet this objective, the eight models were compared in terms of their accuracy (RMSE), linearity (coefficient of determination, R2, and adjusted coefficient of determination, R2adj), and prediction potential. The latter was evaluated by correlating the model parameters to basic soil properties. Retention data for 137 undisturbed soils from the Unsaturated Soil Hydraulic Database (UNSODA) were used for the model comparison. The samples showed considerable differences in texture, bulk density, and organic matter content. All functions were found to provide relatively realistic fits and anchored the curve at zero soil water content for the coarse‐textured soils. The performance criteria were similar when averaged across all data sets. The criteria were found to be statistically different between the eight models only for the sandy clay loam soil textural class. An analysis of the individual data sets separately showed that the performance criteria were statistically different between the models for 17 data sets belonging to six different textural classes. We found that the Khlosi model with four parameters was the most consistent among different soils. Its prediction potential was also relatively good due to significant correlation between its parameters and basic soil properties.
Modeling Transport of Microbes in Ten Undisturbed Soils under Effluent Irrigation
Authors: Pang Liping , McLeod Malcolm , Aislabie Jacqueline , Šimůnek Jirka , Close Murray , Hector Ross
Published: January 2008

The HYDRUS‐1D mobile–immobile water model (MIM) was used to evaluate the transport of fecal coliforms, Salmonella bacteriophage, and Br in 10 soils. At a flux of 5 mm h−1, a pulse of dairy shed effluent was applied to 30 large undisturbed lysimeters, followed by water irrigation. Soil types included clayey gley soil, clay loam, silt loam, silt loam over gravels, fine sandy loam, dune sand soil, pumice soil, and allophanic soil. Except for dune sand, modeling results showed lower mobile water contents and dispersivities for microbes than for Br, indicating the exclusion of microbes from smaller pores. The MIM‐derived removal rates were in the order: volcanic soils > greywacke‐derived silt loams > granular young sandy soils, and were the most variable in clayey gley loam and silt loam over gravels. Microbial reduction was 100% in allophanic soil, 16 to 18 log m−1 in pumice soil (where the unit log is the log10 reduction in maximum concentration compared with the original concentration), and was lowest in clayey gley soil (0.1–2 log m−1). For most of the other soils, the reduction was 2 to 3 log m−1, except for 9 to 10 log m−1 for fecal coliforms in a fine sandy loam. The detachment rate was only 1% of the attachment rate, indicating irreversible attachment of microbes. Soil structure (macroporosity) appeared to play the most important role in the transport of microbes and Br, while soil lithology had the greatest influence on attenuation and mass exchange. The general pattern of predicted mobile water content agrees with the measured macroporosity, which is positively related to leaching vulnerability but negatively related to dispersivity.
Alternative approaches in the conceptualization of social capital
Authors: Golubovic Natasa , Golubovic Srdjan
Published: January 2008

Despite the great interest for the concept and a considerable number of papers that deal with the subject of social capital, yet there is no unique and consistent definition of social capital. Forming a consistent theory of social capital is hindered by the presence of several different approaches in the analysis of this phenomenon. Depending on the author?s theoretical position in the definition of social capital or the analysis of its sources, components and outcomes, the emphasis rests on different social processes and relationships. The aim of this paper is to analyze alternative approaches in the conceptualization of social capital, their advantages and shortfalls, and their implications for the development of the social capital theory.
Paleogene-early miocene deformations of Bukulja-Vencac crystalline (Vardar zone, Serbia)
Authors: Marovic Milun , Djokovic Ilija , Toljic Marinko , Milivojevic Jelena , Spahic Darko
Published: January 2008

Low-grade metamorphic rocks of the crystalline of Mts. Bukulja and Vencac, which are integral parts of the Vardar Zone, are of Late Cretaceous age. From the Middle Paleogene to the beginning of the Miocene, they were subjected to three phases of intensive deformations. In the first phase, during the Middle Paleogene, these rocks were subjected to intense shortening (approximately in the E-W direction), regional metamorphism and deformations in the ductile and brittle domains, when first-generation folds with NNE-SSW striking fold hinges were formed. In the second phase, during the Late Oligocene and up to the Early Miocene, extensional unroofing and exhumation of the crystalline occurred, which was followed by intrusion of the granitoid of Bukulja and refolding of the previously formed folds in a simple brachial form of Bukulja and Vencac with an ESE-WNW striking B-axis. The third phase was expressed in the Early lowermost Miocene (before the Ottnanghian), under conditions of NE-SW compression and NW-SE tension. It was characterized by wrench-tectonic activity, particularly by dextral movements along NNW-SSE striking faults.
Extensional unroofing of the Veliki Jastrebac dome (Serbia)
Authors: Marovic Milun , Djokovic Ilija , Toljic Marinko , Spahic Darko , Milivojevic Jelena
Published: January 2008

This paper presents the basic structural elements of the dome of Veliki Jastrebac, as well as the chronology and mechanisms of the deformational events responsible for its formation. It was determined that the dome of Veliki Jastrebac consists of two large sequences which are, in the vertical section, in the inverse position. The lower part is made of Late Cretaceous and Cretaceous-Palaeogene low-grade to medium-grade metamorphic rocks, which are intruded by Paleogene granitoid (probably the Vardar Zone), which are covered with a large overthrust consisting metamorphics of the Serbian-Macedonian Mass. The low-grade to medium-grade metamorphosed complex of Veliki Jastrebac, with the granitoid, represents a metamorphic core complex, exhumed by mechanisms of extensional tectonics in the Paleogene.
COST531 project: Study of the advanced materials for lead free soldering
Authors: Kroupa A. , Dinsdale A.T. , Watson A. , Vrestal J. , Zemanova A.
Published: January 2008

The COST 531 [1] project runt in the years 2002-2007, and dealt with the materials suitable for lead-free soldering. The main aim was to increase the basic knowledge on possible alloy systems that were used or planned to be used as lead-free solder materials and offer scientific information about these materials in order to replace the currently used lead-containing solders. The databases of materials and thermodynamic properties are one of the expected results and the basic features and properties of the thermodynamic database, allowing to model phase diagrams in multicomponent systems, are described in following paper.
Supplementary X-ray studies of the Ni-Sn-Bi system
Authors: Vassilev G.P. , Lilova K.I. , Gachon J.C.
Published: January 2008

Phase equilibria were studied in the system Ni-Sn-Bi. Special attention has been paid to the identification of the recently found ternary phase. For this purpose samples were synthesized using intimately mixed powders. After annealing and quenching, all alloys were analyzed by scanning electron microscope and by X-ray diffraction. The results give evidences about the existence of a ternary compound with approximate formula Ni6Sn2Bi to Ni7Sn2Bi. Overlapping of some neighboring diffraction peaks of this phase with NiBi and Ni3Sn_LT is the reason for the difficulties related to the X-ray diffraction identification of the ternary phase.
A linear solvation energy relationship study for the reactivity of 2-substituted cyclohex-1-enecarboxylic and 2-substituted benzoic acids with diazodiphenylmethane in aprotic and protic solvents
Authors: Nikolic Jasmina , Uscumlic Gordana
Published: January 2008

The rate constants for the reaction of 2-substituted cyclohex-1-enecarboxylic acids and the corresponding 2-substituted benzoic acids with diazodiphenylmethane were determined in various aprotic solvents at 30 ?C. In order to explain the kinetic results through solvent effects, the second order rate constants of the reaction of the examined acids were correlated using the Kamlet-Taft solvatochromic equation. The correlations of the kinetic data were carried out by means of multiple linear regression analysis and the solvent effects on the reaction rates were analyzed in terms of the contributions of the initial and transition state. The signs of the equation coefficients support the proposed reaction mechanism. The quantitative relationship between the molecular structure and the chemical reactivity is discussed, as well as the effect of geometry on the reactivity of the examined molecules.
Quantitative analysis of sesquiterpene lactone cnicin in seven Centaurea species wild-growing in Serbia and Montenegro using 1H-NMR spectroscopy
Authors: Tesevic Vele , Milosavljevic Slobodan , Vajs Vlatka , Janackovic Pedja , Djordjevic Iris , Jadranin Milka , Vuckovic Ivan
Published: January 2008

1H-NMR spectroscopy was applied for the quantitative analysis of cnicin, a bioactive germacranolide type sesquiterpene lactone, in the aerial parts of seven wild-growing Centaurea species collected in Serbia and Montenegro. The analysis was performed by comparison of the integral of the one-proton signal of cnicin (H-13, ? 5.75) with that of the two-proton singlet ( ? 6.98) of 2,6-bis(1,1-dimethylethyl)-4-methylphenol (BHT), used as the internal standard. Cnicin, within the concentration range 1.06-6.12 mg/g, calculated per weight of the fresh plant material was detected in six species, the exception being C. salonitana. This method allows the rapid and simple quantification of cnicin without any pre-purification step.
Effect of temperature on the electrodeposition of disperse copper deposits
Authors: Nikolic Nebojsa , Pavlovic Ljubica , Pavlovic Miomir , Popov Konstantin
Published: January 2008

The effect of temperature on the electrodeposition of copper at overpotentials belonging to the plateau of the limiting diffusion current density and higher was examined by the determination of the average current efficiency of hydrogen evolution and by scanning electron microscopic (SEM) analysis of the morphology of the formed copper deposits. Increasing the temperature of the solution led to a shift of both the beginning and the end of the plateau of the limiting diffusion current density towards lower electrodeposition overpotentials. Also, higher temperatures led to the formation of morphological forms of copper deposits characteristic for electrodeposition of copper at some higher overpotentials. The unexpected trend in the development of copper structures electrodeposited at an overpotential of 800 mV is discussed in terms of the effect of temperature on the viscosity and surface tension of the electroplating solution.
Mixtures of methanol and 2-propanol as a potential fuel for direct alcohol fuel cells
Authors: Gojkovic S.Lj. , Tripkovic A.V. , Stevanovic R.M.
Published: January 2008

The electrochemical oxidation of methanol, 2-propanol, and their mixtures was investigated on a Pt/C thin film electrode in acid solution. It was confirmed that the oxidation of 2-propanol commences at less positive potentials than that of methanol and exhibits significantly higher oxidation current densities at low potentials. When both methanol and 2-propanol were present in the solution, the onset of the oxidation current was the same as for the oxidation of pure 2-propanol. Although both alcohols inhibit the oxidation reaction of each other to a certain extent, steady-state polarization measurements showed that their mixture provides higher current densities than single alcohols over the entire potential region from the hydrogen region to oxide formation on the Pt surface. This implies that the addition of 2-propanol into the fuel may extend the operational range of direct methanol fuel cells.
Determination of various insecticides and pharmaceuticals using differently modified glassy carbon electrodes
Authors: Gaál Ferenc , Guzsvány Valéria , Bjelica Luka
Published: January 2008

The applicability of differently modified glassy carbon (GC) electrodes for direct or indirect determinations of various physiologically active compounds (insecticides and pharmaceuticals) in different formulations and some real samples was investigated. Samples of selected insecticides from the group of neonicotinoids with nitroguanidine (thiamethoxam and imidacloprid), cyanoimine (acetamiprid) and nitromethilene (nitenpyram) fragments, prepared in an appropriate manner, were determined by voltammetry on bare and surface-modified GC electrodes, while in the case of pharmaceuticals such as Trodon and Akineton, the chloride anion titration was followed using bare GC and phosphorus doped (P-GC) electrodes. The P-GC was also used to monitor the chloride content in the photocatalytic degradation of the (4-chloro-2-methylphenoxy)acetic acid herbicide. It was found that apart from the nature of the electrode material, the analyte and supporting electrolyte, as well as the pretreatment of the electrode surface essentially influences the applicability of the employed sensors.
Influence of Bi2O3 on microstructure and electrical properties of ZnO-SnO2 ceramics
Authors: Ivetic T. , Nikolic M.V. , Slankamenac M. , Zivanov M. , Minic D. , Nikolic P.M. , Ristic M.M.
Published: January 2008

The effects of small amounts (0.5; 1.0 and 1.5 mol. %) of bismuth oxide on the microstructure and electrical properties of ZnO-SnO2 ceramics have been studied. Starting powders of ZnO and SnO2 were mixed in the molar ratio 2:1. After adding Bi2O3 this mixture was mechanically activated for 10 minutes in a planetary ball mill, uniaxially pressed and sintered at 1300?C for 2h. The phase composition of the sintered samples was analyzed by X-Ray Diffraction (XRD) and by Energy Dispersive Spectrometer (EDS). Morphologies were examined by Scanning Electron Microscopy (SEM). An Impedance/Gain Phase Analyzer (HP 4194A) was used to measure the impedance spectra (100Hz - 10MHz) at different temperatures. The electrical DC resistivity/conductivity at different temperatures was measured using a High Resistance Meter (HP 4329A).
Co-combustion: A summary of technology
Authors: Leckner Bo
Published: January 2008

Co-combustion of biomass or waste together with a base fuel in a boiler is a simple and economically suitable way to replace fossil fuels by biomass and to utilize waste. Co-combustion in a high-efficiency power station means utilization of biomass and waste with a higher thermal efficiency than what otherwise had been possible. Due to transport limitations, the additional fuel will only supply a minor part (less than a few hundreds MW fuel) of the energy in a plant. There are several options: co-combustion with coal in pulverized or fluidized bed boilers, combustion on added grates inserted in pulverized coal boilers, combustors for added fuel coupled in parallel to the steam circuit of a power plant, external gas producers delivering its gas to replace an oil, gas or pulverized fuel burner. Furthermore biomass can be used for reburning in order to reduce NO emissions or for afterburning to reduce N2O emissions in fluidized bed boilers. Combination of fuels can give rise to positive or negative synergy effects, of which the best known are the interactions between S, Cl, K, Al, and Si that may give rise to or prevent deposits on tubes or on catalyst surfaces, or that may have an influence on the formation of dioxins. With better knowledge of these effects the positive ones can be utilized and the negative ones can be avoided.
Evaluation of distributional solar radiation parameters of Cacak using long-term measured global solar radiation data
Authors: Dragicevic Snezana , Vuckovic Nikola
Published: January 2008

Serbia is becoming more dependent on imported primary energy to meet its increasing energy demand. The ratio of indigenous primary energy production to primary energy consumption is decreasing. Therefore, it is of great importance for Serbia to make use of its indigenous energy resources more effectively, including its solar energy potential. Knowledge of global solar radiation is essential in the prediction, study, and design of the economic viability of systems which use solar energy. In this paper, the solar radiation data on Cacak (lat 43.87?N, long 20.33?E) are analyzed based on 4 years of global solar radiation data measured on a horizontal surface. The distributional solar radiation parameters are derived from the available data and analyzed. The available solar radiation data on a horizontal surface are converted to that of various tilt angles and the yearly and monthly optimum tilt angles are determined.
Connection between participation in sport and pro-social orientation and aggression of adolescents: Differences according to gender
Authors: Gasic-Pavisic Slobodanka , Janjetovic Dragan
Published: January 2008

Former researches on the contribution of organized sport to antisocial and pro-social behavior of the young have yielded discordant and contradictory results. However, in the majority of researches, it was determined that active practice of sport has a different effect on psycho-social development of male and female participants. We have undertaken the research with the aim of examining whether there is a connection between the participation of the pupils of secondary school age in organized sport activities and their pro-social value orientation and aggressiveness, and, if there is, whether there are gender differences in that connection. The sample consisted of 300 pupils of secondary school (Mathematical High School in Belgrade), out of which 150 (49 female and 101 male) regularly practice sport for more than two years, and 150 pupils (84 male and 66 female) do not practice organized sport. The indicators of practicing sport are: the length of practicing sport activities, regularity and intensity of training, participation in contests and the kind of sport (individual or team sport). The following variables of pro-social orientation were examined: readiness for cooperation, caring for other people, social responsibility and empathy. Aggressiveness was examined through aggressive tendencies towards others. All variables were examined by the application of appropriate questionnaires and evaluation scales which were answered by the pupils themselves. The results have shown significant (although low), positive correlations between practicing sport and pro-social values, as well as the negative (low) correlation between practicing sport and aggression, for both genders of students. Statistically significant differences were found between boys and girls regarding pro-social orientation (higher level in girls), as well as aggressiveness (higher levels in boys). Significant correlations were lower and more numerous in male than in female respondents.
Effects of Whole-Body Vibration Exercise on Lower-Extremity Muscle Strength and Power in an Older Population: A Randomized Clinical Trial
Authors: Rees Sven S , Murphy Aron J , Watsford Mark L
Published: January 2008

Background and Purpose

Vibration training is a relatively new exercise intervention. This study investigated the effects of vibration exercise on strength (force-producing capacity) and power in older adults who are healthy.

Participants and Methods

Thirty participants (mean age=73.7 years, SD=4.6) were randomly assigned to a vibration exercise training (VIB) group or an exercise without vibration training (EX) group. The interventions consisted of 3 sessions per week for 8 weeks. Outcome measures included isokinetic flexor and extensor strength and power of the hip, knee, and ankle.

Results

The VIB group significantly improved ankle plantar flexor strength and power compared with the EX group. However, there were no significant differences between the VIB and EX groups for knee flexor or extensor strength.

Discussion and Conclusion

Vibration training contributed to an increase in plantar flexor strength and power. However, the strength gains for the knee and hip flexors and extensors for the VIB group and the EX group were comparable. Future vibration protocols should explore different body positions to target muscles higher up on the leg.
Strong Unique Continuation Property for the Dirac Equation
Authors: De Carli Laura , Ōkaji Takashi
Published: January 2008

We discuss some Carleman type inequalities which lead to a strong unique continuation property for Dirac operators with potential dominated by the Coulomb singularity.
A Theorem of Tits, Normalizers of Maximal Tori and Fibrewise Bousfield–Kan Completions
Authors: Neuman Frank
Published: January 2008

We use a theorem of Tits on the presentation of the normalizer of a maximal torus of a connected compact semisimple Lie group in terms of generators and relations to give several equivalent conditions for the splitting of the associated normalizer group extension and interprete them in terms of
p
-adic fibrewise homotopy theory.
Coincidence Points for Perturbations of Linear Fredholm Maps of Index Zero
Authors: Agarwal Ravi P. , O'Regan Donal
Published: January 2008

Coincidence points for single and set valued maps are discussed in this paper. We show if

F

is essential and

F \cong G

then

G

has a coincidence point.
An Integral Transformation and its Applications to Harmonic Analysis on the Space of Solutions of the Heat Equation
Authors: Chung Soon-Yeong , Yeom Yongjin
Published: January 2008

We introduce an integral transformation

T

defined by

(Tf)(x,t) = ∫ e^{−ixy−t|y|^2} f(y)dy,\quad f\in L^1(\boldsymbol R^n)

in order to do harmonic analysis on the space of

C^∞

solutions of the heat equation.

First, the Paley–Wiener type theorem for the transformation

T

will be given for the

C^∞

functions and distributions with compact support.

Secondly, as an application of the transformation the solutions of heat equation given on the torus

T^n

will be characterized.

Finally, we represent solutions of the heat equation as an infinite series of Hermite temperatures, which are to be defined as the images of Hermite polynomials under the transformation

T

.
Algebraic Coset Conformal Field Theories II
Authors: Xu Feng
Published: January 2008

Some mathematical questions relating to coset conformal field theories (CFT) are considered in the framework of algebraic quantum field theory as developed previously by us. We consider the issue of fix point resolution in the diagonal cosets of type A. We show how to decompose certain reducible representations into irreducibles, and prove that the coset CFT gives rise to a unitary modular category and therefore may be used to construct 3-manifold invariants. We prove that if the coset inclusion satisfies certain conditions which can be checked in examples, the Kac–Wakimoto Hypothesis (KWH) is equivalent to the Kac–Wakimoto Conjecture (KWC), a result which seems to be hard to prove by purely representation considerations. Examples are also presented.
Multiple Poles at Negative Integers for $\int_Af^λ☐$ in the Case of an Almost Isolated Singularity
Authors: Barlet Daniel
Published: January 2008

We give a necessary and sufficient topological condition on

A\in H^0(\{f≠ 0\},ℂ)

, for a real analytic germ

f: (ℝ^{n+1},0) → (ℝ,0)

, whose complexification has an isolated singularity relatively to the eigenvalue 1 of the monodromy, in order that the meromorphic continuation of

\int_Af^λ☐

has a multiple pole at sufficiently “large” negative integers. We show that if such a multiple pole exists, it occurs already at

λ = −(n + 1)

with its maximal order which is computed topologically.

Nous donnons une condition necessaire et suffisante topologique sur

A\in H^0(\{f≠ 0\},ℂ)

, pour un germe analytique réel

f: (ℝ^{n+1},0) → (ℝ,0)

, dont la complexifiée présente une singularité isolée relativement á la valeur propre 1 de la monodromie, pour que le prolongement analytique de

\int_Af^λ☐

présente un pôle multiple aux entiers négatifs assez “grands.” On montre en particulier que si un tel pôle multiple existe, il apparaît déjà pour

λ = −(n + 1)

avec l'ordre maximal que nous calculons topologiquement.
On Totally Characteristic Type Non-linear Partial Differential Equations in the Complex Domain
Authors: Chen Hua , Tahara Hidetoshi
Published: January 2008

The paper deals with a singular non-linear partial differential equation

t∂u/∂t = F(t, x, u, ∂u/∂x)

with two independent variables

(t,x) \in \boldsymbol C^2

under the assumption that

F(t, x, u,v)

is holomorphic and

F(0,x,0,0) = 0

. Set

γ(x) = (∂F/∂v)(0,x,0,0)

. In case

γ(x) = 0

the equation was investigated quite well by Gérard–Tahara [3]. In case

γ(0) = 0

and

\mathrm{Re}\,γ' < 0

the existence of holomorphic solution was proved in Chen–Tahara [2] under a non-resonance condition. The present paper proves the existence of holomorphic solution under the same non-resonance condition but using the following weaker condition:

γ(0) = 0

and

γ'(0) \in \boldsymbol C \backslash [0, ∞)

. The result is extended to higher order equations.
Propagation of Singularities in the Ramified Cauchy Problem for a Class of Operators with Non-involutive Multiple Characteristics
Authors: Igari Katsuju
Published: January 2008

In the ramified Cauchy problem, analytic continuation of holomorphic solutions has been mainly studied. In this paper, we prove the propagation of singularities for a class of linear partial differential equations with non-involutive multiple characteristics.
The Furuta Inequality and an Operator Equation for Linear Operators
Authors: Lin Chia-Shiang
Published: January 2008

We show that a special form of the Futura inequality is equivalent to an operator equation

H^{\frac{p-2rn}{2(n+1)}} T (H^{\frac{p+2r}{n_+1}} T)^n H^{\frac{p-2_rn}{2(n+1)}} = K^p

.
This result also generalizes Lemma 1 in [3] which is about the operator equation

T(H^{1/n}T)^n = K

. A new characterization of the Löwner–Heinz formula and some applications are given.
Resonances for a Semi-Classical Schrödinger Operator Near a Non Trapping Energy Level
Authors: Rouleux Michel
Published: January 2008

We give an example of a short range potential F on the real line that is dilation analytic at infinity, non trapping at energy
E
>0, but oscillating in the neighborhood of some points, so rapidly that the Schrödinger operator
P
=-_h_2Δ+
V
shows a string of resonances near
E
in the lower half plane when
h
>0 is small enough. The extended states behave as standing waves partially reflected off the bumps of
V
. Such a potential is the analogue of the Wigner-Von Neumann potential in the case of embedded eigenvalues.
Pairings of $p$-Compact Groups and $H$-Structures on the Classifying Spaces of Finite Loop Spaces
Authors: Ishiguro Kenshi
Published: January 2008

We consider the maps between classifying spaces of

p

-compact groups of the form

BX \times BY → BZ

. The main theorem shows that if the restriction map on

BY

is a weak epimorphism, then the restriction on

BX

should factor through the classifying spaces of the center of the

p

-compact group

Z

.
Higher-Codimensional Boundary Value Problems and $F$-Mild Microfunctions —Local and Microlocal Uniqueness—
Authors: Oaku Toshinori , Yamazaki Susumu
Published: January 2008

For the study of local and microlocal boundary value problems with a boundary of codimension greater than one, sheaves of

F

-mild hyperfunctions and

F

-mild microfunctions are introduced. They are refinements of the notions of hyperfunctions and microfunctions with real analytic parameters and have natural boundary values.

F

-mild solutions of a general

\mathcal D

-Module

\mathcal M

(that is, a system of linear partial differential equations with analytic coefficients) are considered. In particular, local and microlocal uniqueness in the boundary value problem (the Holmgren type theorem) is proved if the boundary is non-characteristic for

\mathcal M

. or else if

\mathcal M

is Fuchsian along the boundary.
Singular Solutions with Asymptotic Expansion of Linear Partial Differential Equations in the Complex Domain
Authors: Ōuchi Sunao
Published: January 2008

We consider a linear partial differential equation with holomorphic coefficients in a neighbourhood of

z=0

in

C^{d+1}

,

P(z, ∂) u(z) = f(z),

where

u(z)

and

f(z)

admit singularities on the surface

K=\{z_0=0\}

. Our main result is the following:

For the operator

P

we define an exponent

γ^*

called the minimal irregularity of

K

and show that if

u(z)

grows at most exponentially with exponent

γ^*

as

z_0

tends to

0

and if

f(z)

has a Gevrey type expansion of exponent

γ^*

with respect to

z_0

, then

u(z)

also has the same one.
An Inverse Scattering Problem for Dirac Equations with Time-Dependent Electromagnetic Potentials
Authors: Ito Hiroshi T.
Published: January 2008

We consider an inverse scattering problem, by using a time-dependent method, for the Dirac equation with a time-dependent electromagnetic field. The Fourier transform of the field is reconstructed from the scattering operator on a Lorents invariant set

D: = \{(τ, ξ) \in \boldsymbol R \times \boldsymbol R^3;|τ|<c|ξ|\}

in the dual space of the space-time. As corollaries of this result, we can reconstruct the electromagnetic field completely if it is a finite sum of fields each of which is a time-independent one by a suitable Lorentz transform, and we can also determine the field uniquely if the fields satisfies some exponential decay condition. Our assumptions and results are independent of a choice of inertial frames.
On the Hydrodynamic Limit of the Enskog Equation
Authors: Lachowicz Miroslaw
Published: January 2008

The Enskog equation in the hydrodynamie limit is investigated. If the Knudsen number

ε

and the scale of diameter

a

of the hard sphere particles are of the same order, the resulting system of hydrodynamie equations (the Enskog–Euler system) is different from that for the Boltzmann equation. The existence and uniqueness theorem, in this case for the Enskog equation, is proven on the time interval independent of the small parameters. As

ε ↓ 0

, the solution of the Enskog equation tends to the Maxwellian whose fluid-dynamic parameters solve the Enskog–Euler system. As a by-product — the existence theorem for the Enskog–Euler system is obtained.
Commuting Squares and the Classification of Finite Depth Inclusions of AFD Type $\mathrm{III}_λ$ Factors, $λ \in (0, 1)$
Authors: Loi Phan H.
Published: January 2008

We give a new proof of the classification result due to Sorm Popa that a finite depth inclusion of AFD type

\mathrm{III}_λ

factors

N ⊂ M

,

λ ∈ (0, 1)

, with a common discrete decomposition

\{N^∞ ⊂ M^∞, θ\}

is classified, up to isomorphism, by the type

\mathrm{II}

core

N^∞ ⊂ M^∞

and the standard invariant of

θ

.
Quantum Toroidal Algebras and Their Vertex Representations
Authors: Saito Yoshihisa
Published: January 2008

We construct the vertex representations of the quantum toroidal algebras

U_q(\mathfrak{sl}_{n+ 1,\mathit{tor}})

. In the classical case the vertex representations are not irreducible. However in the quantum case they are irreducible.
Quadratic Weyl Representations
Authors: Robinson Paul Lee
Published: January 2008

We offer a new construction for the quadratic representations of the canonical commutation relations introduced by Proksch, Reents and Summers; our construction, which is related to the metaplectic representation, automatically produces the quadratic representations in Weyl form, circumventing the use of unbounded operators.
The Exactness Theorem for Floer Homology
Authors: Wang Hong-Yu
Published: January 2008

In this article, we study a long exact sequence relating the mstanton homology of two homology 3-spheres which are obtained from each other by ± 1 -surgery. We prove that the long exact sequence, via a short exact sequence of chain complex, is the same as the sequence defined by the exact triangle of cobordisms introduced by Floer.
An Upper Bound for the Characteristic Variety of an Induced $\mathscr D$-Module
Authors: Menezes Carlos
Published: January 2008

We generalise the

\textit{Car}^Z_Y (\mathfrak M)

upper bound of Laurent & Schapira [LS87] for the characteristic variety of the induced system of a coherent

\mathscr D_x

-module

\mathfrak M

on a hypersurface

Y

of

X

to the case where

Y

is a smooth submanifold of

X

of arbitrary codimension.
Nonlinear Singular First Order Partial Differential Equations Whose Characteristic Exponent Takes a Positive Integral Value
Authors: Yamane Hideshi
Published: January 2008

We consider nonlinear singular partial differential equations of the form

(tD_t–ρ(x))u = ta(x)+G_2(x)(t, tD_tu, u, D_1u,...,D_nu)

.

It has been proved by Gérard and Tahara that there exists a unique holomorphic solution with

u(0, x) ≡ 0

if the characteristic exponent

ρ(x)

avoids positive integral values. In the present paper we consider what happens if

ρ(x)

takes a positive integral value at

x=0

. Genetically, the solution

u(t, x)

is singular along the analytic set

\{t=0,\ ρ(x) \in \mathbf N^*\}

,

\mathbf N^*=\{1, 2,...\}

, and we investigate how far it can be analytically continued.
Goursat Problem for a Microdifferentlal Operator of Fuchsian Type and Its Application
Authors: Yamazaki Susumu
Published: January 2008

We consider a matrix of microdifferential operators of Fuchsian type with respect to several variables and obtain the Cauchy-Kovalevskaja type theorem for the Goursat problem. Moreover, we prove the existence theorem in the framework of microfunctions under some assumptions for initial values and the operator.
Operator Convex Functions of Several Variables
Authors: Hansen Frank
Published: January 2008

The functional calculus for functions of several variables associates to each tuple

x= (x_1, ⋯, x_k)

of selfadjoint operators on Hilbert spaces

H_1, ⋯,H_k

an operator

f(x)

in the tensor product

B(H_1)⊗ ⋯ ⊗B(H_k)

. We introduce the notion of generalized Hessian matrices associated with
f
. Those matrices are used as the building blocks of a structure theorem for the second Fréchet differential of the map

x → f(x)

. As an application we derive that functions with positive semi-definite generalized Hessian matrices of arbitrary order are operator convex. The result generalizes a theorem of Kraus [15] for functions of one variable.
Connectedness of the Fibers of a Liouvillian Function
Authors: Paul Emmanuel
Published: January 2008

Let

D

be a normal crossing divisor in a complex analytic manifold of dimension

n

, and let

Ω

be a closed logarithmic one-form, with poles on

D

. Under appropriate hypothesis, we prove the connectedness of the fibers for a primitive of

Ω

in “good” neighborhoods of

D

. We deduce the connectedness of the fibers of Liouvillian functions of type

f= f_1^{λ_1} ⋯ f_p^{λ_p}

at the origin of

\boldsymbol C^n

, under two conditions: the first extends the usual notion that “

f

is not a power”. The second excludes certain meromorphic functions.
On Certain Multiple Bailey, Rogers and Dougall Type Summation Formulas
Authors: van Diejen Jan F.
Published: January 2008

A multidimensional generalization of Bailey's very-well-poised bilateral basic hypergeometric

{}_6Ψ_6

summation formula and its Dougall type

{}_5H_5

hypergeometric degeneration for

q → 1

is studied. The multiple Bailey sum amounts to an extension corresponding to the case of a nonreduced root system of certain summation identities associated to the reduced root systems that were recently conjectured by Aomoto and Ito and proved by Macdonald. By truncation, we obtain multidimensional analogues of the very-well poised unilateral (basic) hypergeometric Rogers

{}_6\phi_5

and Dougall

{}_5F_4

sums (both nonterminating and terminating). The terminating sums may be used to arrive at product formulas for the norms of recently introduced (

q

-)Racah polynomials in several variables.
Fourier Transform for Paragroups and Its Application to the Depth Two Case
Authors: Sato Nobuya
Published: January 2008

We prove that the flatness condition in Ocneanu's paragroup theory for graphs with depth two is equivalent to existence of the multiplicative unitaries in the theory of Baaj-Skandalis by using "Fourier transform" introduced by A. Ocneanu. Moreover, from two Kac algebras dual to each other, we construct a subfactor as a crossed product by a Kac algebra action, with the string algebra construction.
Topological Tensor Products of Unbounded Operator Algebras on Frechet Domains
Authors: Heinrichs Wolf-Dieter
Published: January 2008

The aim of this paper is to investigate topological properties of unbounded operator algebras

\mathcal A⊂L^+(D)

and its stability under the formation of topological tensor products

\mathcal A_1 \otimes_\alpha \mathcal A_2

. It is used the method to define topological properties by operator.
Quantum Current Operators-I Zeros and Poles of Quantum Current Operators and the Condition of Quantum Integrability
Authors: Ding Jintai , Miwa Tetsuji
Published: January 2008

For the current realization of the affine quantum groups, a simple comultiplication for the quantum current operators was given by Drinfeld. With this comultiplication, we study the zeros and poles of the quantum current operators and present a condition of integrability on the quantum current operators of

U_q(\hat{\mathfrak{sl}}(2))

, which is a deformation of the corresponding condition for

\hat{\mathfrak{sl}}(2)

. We also present the results about the zeros and poles of the quantum current operators of

U_q(\hat{\mathfrak{sl}}(n))

.
Quantum Current Operators-II Difference Equations of Quantum Current Operators and Quantum Parafermion Construction
Authors: Ding Jintai , Feigin Boris
Published: January 2008

For the current realization of the affine quantum groups, a simple comultiplication for the quantum current operators was given by Drinfeld. With this comultiplication, we prove that, for the integrable modules of

U_q(\hat{\mathfrak{sl}}(2))

of level

k + 1

,

x^±(z)x^±(zq^{±2}) ⋯ x^±(zq^{±2k})

are vertex operators satisfying certain q-difference equations, and we derive the quantum parafermions of

U_q(\hat{\mathfrak{sl}}(2))

.
Generalization and Exact Deformations of Quantum Groups
Authors: Frønsdal Christian
Published: January 2008

A large family of “standard” coboundary Hopf algebras is investigated. The existence of a universal R-matrix is demonstrated for the case when the parameters are in general position. Algebraic surfaces in parameter space are characterized by the appearance of certain ideals; in this case the universal R-matrix exists on the associated algebraic quotient. In special cases the quotient is a “standard” quantum group; all familiar quantum groups including twisted ones are obtained in this way. In other special cases one finds new types of coboundary bi-algebras.

The “standard” universal R-matrix is shown to be the unique solution of a very simple, linear recursion relation. The classical limit is obtained in the case of quantized Kac–Moody algebras of finite and affine type.

Returning to the general case, we study deformations of the standard R-matrix and the associated Hopf algebras. A preliminary investigation of the first order deformations uncovers a class of deformations that incompasses the quantization of all Kac–Moody algebras of finite and affine type. The corresponding exact deformations are described as generalized twists,

R_\epsilon = (F^t)^{–1}RF

, where

R

is the standard R-matrix and the cocycle

F

(a power series in the deformation parameter

\epsilon

) is the solution of a linear recursion relation of the same type as that which determines

R

. Included here is the universal R-matrix for the elliptic quantum groups associated with

\textit{sl}(n)

, a big surprise!

Specializing again, to the case of quantized Kac–Moody algebras, and taking the classical limit of these esoteric quantum groups, one re-discovers all the trigonometric and elliptic r-matrices of Belavin and Drinfeld. The formulas obtained here are easier to use than the original ones, and the structure of the space of classical r-matrices is more transparent. The r-matrices obtained here are more general in that they are defined on the full Kac–Moody algebras, the central extensions of the loop groups.
Local Uniqueness in the Cauchy Problem for Second Order Elliptic Equations with Non-Lipschitzian Coefficients
Authors: Tarama Shigeo
Published: January 2008

We show the local uniqueness of the Cauchy problem for the second order elliptic operators whose coefficients of the principal part are real-valued and continuous with some modulus of continuity. These coefficients are not necessarily lipschitz continuous. The proof is given by drawing the Carleman estimates with a weight attached to the modulus of continuity.
On Algebraic #-Cones in Topological Tensor Algebras II. Closed Hulls and Extremal Rays
Authors: Hofmann Gerald
Published: January 2008

The investigations on the structure of alg-# cones [
F
, #} in topological tensor algebras are continued, and they are aimed at the closed hulls and the extremal rays of such cones. Among others, it is proven that the elements of the closed hulls of a large class of alg-# cones with respect to some intermediate I.e. topologies are explicitely given by (infinite) sums of elements of (
F
, #}. Furthermore, a Krein-Milman like theorem is shown for some alg# cones, i.e., it is shown that there are enough extremal rays m {
F
, # } so that every element of {
F
, #} is an (infinite) sum of extremals of {
F
, #}.
Picard Groups of Hypersurfaces In Toric Varieties
Authors: Roan Shi-shyr
Published: January 2008

We study the structure of rational Picard groups of hypersurfaces of toric varieties. By using the fan structure associated to the ambient toric variety, an explicit basis of the Picard group is described by certain combinatorial data. We shall also discuss the application to Calabi-Yau spaces.
Cancellation and Non Cancellation Phenomena for Infinite Complexes
Authors: Shitanda Yoshimi
Published: January 2008

Let

L(I, J)

be defined by the pull-back of

CP^∞_1 → K(Q, 2) ← Ω S_J^3

where

\{I, J\}

is a partition of all primes. We classify spaces

\{Ω^k Σ^k C(f)\}

of loop-suspension of mapping cone of phantom map

f:L(I, J) → S^3

for

k = 0, 1, ⋯, ∞

which have the same

n

-type for all

n

. In the category of finite
CW
-complexes, cancellation and non cancellation phenomena are well studied. In the category of infinite
CW
-complexes, the phenomena are less known. We study cancellation and non cancellation phenomena for infinite dimensional complexes by using above spaces.
The Initial Value Problem for Cubic Semilinear Schrödinger Equations
Authors: Chihara Hiroyuki
Published: January 2008

We present local and global existence theorems for cubic semilinear Schrödinger equations. Our new results are the improvement of our previous ones ([2] , [3] , [4]). The idea of the proof consists of the energy and the decay estimates. These equations do not allow the classical energy estimates. To avoid this difficulty, we make strong use of S. Doi's method for linear Schrödinger type equations. Combining cubic nonlinearity and S. Doi's method, we obtain the improved results.
An Application of Orthoisomorphisms to Non-Commutative $L^p$-Isometries
Authors: Watanabe Keiichi
Published: January 2008

We prove that if there exists an into linear isometry between non-commutative

L^p

-spaces then there exists an into Jordan

*

-isomorphism between underlying von Neumann algebras, as an application of Araki–Bunce–Wright's theorem concerning the characterization of orthogonality preserving positive maps between preduals. Moreover, we determine the structure of a linear non-commutative

L^p

-isometry when it is surjective and

*

-preserving.
Differential Equations Associated to the $SU(2)$ WZNW Model on Elliptic Curves
Authors: Suzuki Takeshi
Published: January 2008

We study the

SU(2)

WZNW model over a family of elliptic curves. Starting from the formulation developed in [13], we derive a system of differential equations which contains the Knizhnik–Zamolodchikov–Bernard equations [1][9]. Our system completely determines the

N

-point functions and is regarded as a natural elliptic analogue of the system obtained in [12] for the projective line. We also calculate the system for the 1-point functions explicitly. This gives a generalization of the results in [7] for

\widehat{\mathfrak{sl}} (2, \mathbb C)

-characters.
A Discrete Model of the Integer Quantum Hall Effect
Authors: McCann Paul J. , Carey Alan L.
Published: January 2008

A discrete model of the integer quantum Hall effect is analysed via its associated
C
*-algebra. The relationship with the usual continuous models is established by viewing the observable algebras of each as both twisted group C*-algebras and twisted cross products. A Fredholm module for the discrete model is presented, and its Chern character is calculated.
Whittaker Functions for the Large Discrete Series Representations of $SU(2, 1)$ and Related Zeta Integrals
Authors: Koseki Harutaka , Oda Takayuki
Published: January 2008

In terms of classical Bessel function, we represent explicitly the radial part of Whittaker functions on

SU(2, 1)

belonging to the large discrete series representations. Moreover we compute archimedean local

L

-factors corresponding to a construction of

L

-function by Gelbart and Piatetski–Shapiro.