bluuebunny/crossref_metadata_2025 huggingface dataset:
Effectiveness of sealers in counteracting alkali-silica reaction in highway median barriers exposed to wetting and drying, freezing and thawing, and deicing salt
Authors: Bérubé Marc-André , Chouinard Dominique , Pigeon Michel , Frenette Jean , Rivest Michel , Vézina Daniel
Published: July 2002

This study follows another experimental study where different types of sealers were applied on plain and air-entrained large concrete cylinders made with high-alkali contents and highly alkalisilica reactive limestone aggregates. The main objective was to determine the effectiveness of these sealers in counteracting concrete expansion and surface deterioration due to alkalisilica reaction under various exposure conditions. This study indicated that all three sealers tested, the silane-, oligosiloxane-, and polysiloxane-based sealers, could stop concrete expansion due to ASR and even produced contraction, even for concrete cylinders subjected to wetting and drying, freezing and thawing, and sodium chloride solutions. In 1991, the same silane, oligosiloxane, and polysiloxane were applied on sections of median barriers showing various degrees of deterioration due to ASR. These sections were subjected to wetting and drying, freezing and thawing, and, during winter, to deicing salt. The silane was also applied on other sections of the same barriers in 1994. Observations and measurements over 10 years indicate that the aesthetic appearance of these median barriers, particularly those sealed with the silane, was greatly improved, while internal humidity was significantly reduced, and concrete expansion as well, when not arrested. The period of time during which the above three sealers were capable to stop ASR expansion varies with the sealer used and the degree of concrete deterioration at the time of sealing. For instance, the silane, which was the best among all products tested, caused concrete contraction for at least 6 years in median barriers that were severely affected by ASR, and likely for more than 10 years in moderately affected barriers. The overall results confirm the conclusions obtained previously in the laboratory: a good sealer such as the silane tested may greatly improve the aesthetic appearance and stop the expansion of non-massive ASR-affected concrete members, at least up to about 300 mm in thickness, and subjected to wetting and drying, freezing and thawing, and salt water. However, the poor result obtained in the field with another silane-based sealer indicates that a sealer cannot be selected based on its composition only.Key words: alkalisilica reaction, concrete; cracking, expansion, internal humidity, median barrier, sealer, silane, siloxane.
Construction, operation, and maintenance of rubber dams
Authors: Zhang X Q , Tam P W.M , Zheng W
Published: July 2002

Rubber dams are inflatable and deflatable hydraulic structures. Thousands of rubber dams have been installed worldwide for various purposes: irrigation, water supply, power generation, tidal barrier, flood control, environmental improvement, and recreation. Furthermore, rubber dams have been used in cold areas where the temperature is as low as  40°C. The simplicity and flexibility of the rubber dam structure and its proven reliability are key considerations in its wide scope of applications. Based on the management practices of 20 rubber dams in Hong Kong in the past 35 years, interviews with rubber dam experts and practitioners, and the investigation to the construction of a recent rubber dam, this paper provides a detailed discussion on various issues related to the construction, operation, maintenance, and repair of rubber dams.Key words: construction, hydraulic structure, maintenance, operation, repair, rubber dam.
Bacterial lactoferrin receptors: insights from characterizing theMoraxella bovisreceptors
Authors: Yu Rong-Hua , Schryvers Anthony B
Published: July 2002

Moraxella bovis is the causative agent of infectious conjunctivitis in cattle. Moraxella bovis isolates were shown to specifically bind bovine lactoferrin (bLf) and bovine transferrin (bTf) and to use these proteins as a source of iron to support the growth of iron-limited cells. Affinity isolation experiments with immobilized bTf yielded two proteins readily resolved by SDS-PAGE analysis, whereas only a single band of approximately 100 kDa was detected when immobilized bLf was used as the affinity ligand. Using a novel cloning strategy, regions containing the genes encoding the lactoferrin (Lf) and transferrin (Tf) receptor proteins were isolated and sequenced, demonstrating that they both consisted of two genes, with the tbpB or lbpB gene preceding the tbpA or lbpA gene. The cloned lbp genes were used to generate isogenic mutants deficient in lactoferrin binding protein A and (or) B, and the resulting strains were tested in growth and binding assays. The isogenic mutants were deficient in their use of bLf for growth and had substantially diminished bLf binding capability. The predicted amino acid sequence from the segment encoding Lf binding protein B revealed an internal amino acid homology suggesting it is a bi-lobed protein, with a C-lobe enriched in acidic amino acids, but without the evident clustering observed in Lf-binding proteins from other species.Key words: outer membrane protein, iron-binding protein, lactoferrin, receptor, iron, transport, specificity.
Synthesis of ribosomal proteins in developingDictyostelium discoideumcells is controlled by the methylation of proteins S24 and S31
Authors: Mangiarotti Giorgio , Giorda Roberto
Published: July 2002

Ribosomal protein mRNAs left over from growth are selectively excluded from polyribosomes in the first half of Dictyostelium discoideum development. This is due to the fact that they are sequestered by a class of free 40S ribosomal subunits, characterized by possessing a methylated S24 protein. At the time of formation of tight cell aggregates, the methylated S24 is substituted by an unmethylated S24, while protein S31 of the same or other 40S subunits becomes methylated. This leads to a rapid degradation of the ribosomal protein mRNAs.Key words: synthesis of ribosomal proteins, Dictyostelium, methylation of S24, methylation of S31.
Dimorphism and perturbed growth kinetics of cadmium sulfide thin films in a chemical working solution
Authors: Zehe A , Ramírez A , Vázquez J
Published: July 2002

Thin films of numerous compound semiconductors, which crystallize in a (cubic) sphalerite structure, often display an alternative allotropic form as (hexagonal) wurtzite. The relative proportion of each depends in a characteristic manner on the growth conditions chosen. We applied an external magnetic flux during the growth of cadmium sulfide thin films from a chemical working solution, where the CdS molecules or small clusters are formed by a controlled reaction in an aqueous solution. The incorporation mechanism of such neutral particles into the polycrystalline CdS thin film is supposed to happen in a transition layer via a dissociation into charged constituents close to the growing interface. We found a clear effect of the external magnetic field on the film morphology, when the Lorentz force was acting parallel to the surface plane of the layer. Band-gap energy data from optical absorption measurements suggest dimorphism of the grown films, where the field application turns the commonly cubic crystal modification (Eg = 2.38 eV) into a hexagonal polytype with a 200 meV larger energy gap.

PACS Nos.: 81.05Dz, 81.15Lm, 81.15Aa, 81.70Fy, 82.65My, 82.80Ch, 82.80Ej
Covariant approach to equilibration in effective field theories
Authors: Burgess M , Carrington M E , Kunstatter G
Published: July 2002

The equilibration of two coupled reservoirs is studied using a Green function approach that is suitable for future development with the closed time path method. The problem is solved in two parameterizations, to demonstrate the nontrivial issues of parameterization in both the intermediate steps and the interpretation of physical quantities. We use a covariant approach to find self-consistent solutions for the statistical distributions as functions of time. We show that by formally introducing covariant connections, one can rescale a slowly varying nonequilibrium theory so that it appears to be an equilibrium one, for the purposes of calculation. We emphasize the importance of properly tracking variable redefinitions to correctly interpret physical quantities.

PACS Nos.: 11.10-z, 03.70+k, 05.70ln
The physics of putting
Authors: Penner A R
Published: July 2002

The motion of a rolling golf ball on a sloped golf green is modeled. The resulting calculated path of a golf ball is then used, along with a model of the capture of the golf ball by the hole, to determine the resulting launch conditions required for a successful putt. Estimates of the probability of making certain putts are also presented.

PACS No.: 01.80+b
Electron momentum spectroscopy of the frontier electrons of DABCO does not support ansp3hybrid lone-pair description
Authors: Wolfe Saul , Shi Zheng , Brion C E , Rolke James , Zheng Yenyou , Cooper Glyn , Chong Delano P , Hu C Y
Published: July 2002

The highest occupied molecular orbital (HOMO) and next-highest occupied molecular orbital (NHOMO) valence orbital electron density distributions of 1,4-diazabicyclo[2.2.2]octane (DABCO) have been investigated by electron momentum spectroscopy, a technique that probes the orbital-like nature of valence (frontier) electron transfer out of a molecule. The experimental results are compared to a range of 6-311++G** calculations to assess the relative merits of three different orbital models that have commonly been used in chemistry. The delocalized (correlated) canonical KohnSham orbitals calculated using the B3LYP or B3PW91 functionals and density functional theory provide near quantitative agreement with the observed valence electron momentum density distributions, and the delocalized canonical molecular orbitals of HartreeFock (independent particle) theory are in semiquantitative agreement. In contrast, Pauling's widely used and taught valence bond (hybridization) model, which is equivalent to a localized molecular orbital description, does not correspond at all to the experimental measurements. It follows that, for considerations of electron transfer, the "lone pairs" of DABCO are not localized or hybridized, but rather exist as nondegenerate orbitals that are delocalized differently over the molecular framework. The existence of two different experimental valence orbital electron densities of DABCO provides direct confirmation of the frontier orbital HOMONHOMO energy splitting and reordering predicted many years ago by Hoffmann et al. using extended Hückel theory, and interpreted in terms of "through bond" and "through space" interactions.Key words: orbitals, lone pairs, orbital interaction, hybridization.
Magnetic and structural studies on 1,3-diazolate complexes of cobalt(II)  The characterization of three new cobalt(II) molecule-based magnets
Authors: Sánchez Victor , Storr Alan , Thompson Robert C
Published: July 2002

The cobalt(II) compounds ([Co(imid)2]x (1), [Co(2-meimid)2]x (2), [Co(4-meimid)2]x (3), [Co(benzimid)2]x (4), and [Co3(imid)6(imidH)2]x (5) (imid = imidazolate, 2-meimid = 2-methylimidazolate, 4-meimid = 4-methylimi dazolate, benzimid = benzimidazolate)), have been synthesized and structurally and magnetically characterized. Electronic and vibrational spectroscopy and thermogravimetric studies on all five compounds support structures involving tetrahedrally coordinated cobalt centers with single-bridging 1,3-diazolate ligands forming extended polymeric lattices. Moreover, X-ray powder diffraction studies on 1 and 5 established, through isomorphism with published structures, that the molecular connectivity in these materials is 3-D. Variable temperature and applied field magnetization studies revealed antiferromagnetism as the primary magnetic exchange process in all five compounds. In addition, 1, 4, and 5 show magnetic phase transitions to ferromagnetically ordered states below critical temperatures of 16, 13, and 15 K, respectively. Magnetization measurements at 4.8 K as the applied field was cycled between +55 000 and 55 000 G revealed typical hysteresis behavior and gave remnant magnetizations of 334, 257, and 175 cm3 G mol1 and coersive fields of 6620, 5280, and 4140 G for 1, 4, and 5, respectively. No evidence for long-range magnetic order was obtained for either 2 or 3. A comparison of the magnetic properties of three pairs of isostructural iron(II) and cobalt(II) molecule-based magnets shows that while the coersive fields are in general larger for cobalt over iron, the magnitude of the difference varies significantly suggesting that one cannot conclude that cobalt analogues will always be harder magnets.Key words: cobalt(II), 1,3-diazolates, canted spins, molecule-based magnets.
HAMILTONIAN THEORY OF THE RELATIVISTIC STRING
Authors: Pron’ko G.P.
Published: July 2002

The relativistic string theory is considered from the Hamiltonian point of view. It is proposed to formulate the dynamics of string in d-dimensional space-time with the help of the auxiliary spectral problem. This approach gives the possibility to construct a completely new set of variables of string relevant for Lorentz-invariant gauge fixing. The notion of smooth string is introduced for which the successive relativistic invariant quantization could be done explicitly for the d=4 case.
LINK MANIFOLDS AND GLOBAL GRAVITATIONAL ANOMALIES
Authors: BAADHIO RANDY A. , KAUFFMAN LOUIS H.
Published: July 2002

A new method of constructing exotic 11-dimensional structures, as solutions for the cancellation of global gravitational anomalies, is revealed.

The construction makes use of link manifolds. Of relevant interest is the fact that the geometry and topology of the exotic 11-dimensional manifolds are encoded in the classical invariants of knots and links in dimension three.
NOTES ON THE STRUCTURE OF QUANTIZED HERMITIAN SYMMETRIC SPACES
Authors: BORTHWICK DAVID , LESNIEWSKI ANDRZEJ , RINALDI MAURIZIO
Published: July 2002

We give a self-contained presentation of quantization theory for non-compact hermitian symmetric spaces within a non-perturbative scheme, reviewing previously established facts as needed. A number of new results are proven, with emphasis on the algebraic and structural aspects of the theory. In addition, we formulate a number of conjectures concerning the structure of the [Formula: see text]-algebras of quantized functions.
GENERAL ESTIMATES ON DISTORTED RESOLVENTS AND APPLICATION TO STARK HAMILTONIANS
Authors: BRIET PHILIPPE
Published: July 2002

We give a method to obtain estimates on distorted resolvents which we apply to the Stark effect with general potentials. This paper also contains a geometric perturbation theory which together with the estimates mentioned above, shows the existence of resonances and gives an upper bound on the width of resonances in various situations.
EFFECT OF INHERITED GENETIC INFORMATION ON STOCHASTIC PREDATOR-PREY MODEL
Authors: DUDA ARTUR , DYŚ PAWEŁ , NOWICKA ALEKANDRA , DUDEK MIROSŁAW R.
Published: July 2002

We discuss the Lotka–Volterra dynamics of two populations, preys and predators, in the case when the predators posses a genetic information. The genetic information is inherited according to the rules of the Penna model of genetic evolution. Each individual of the predator population is uniquely determined by sex, genotype and phenotype. In our case, the genes are represented by 8-bit integers and the phenotypes are defined with the help of the 8-state Potts model Hamiltonian. We showed that during time evolution, the population of the predators can experience a series of dynamical phase transitions which are connected with the different types of the dominant phenotypes present in the population.
FITTING OF WATER HYDROGEN BOND ENERGY DATA WITH UNCERTAINTIES IN BOTH VARIABLES BY HELP OF ORTHONORMAL POLYNOMIALS
Authors: BOGDANOVA NINA , TODOROV STEFAN
Published: July 2002

We generalize our previously given calculational procedure based on orthogonal polynomial expansions for curve fitting applicable to data with errors only in the dependent variable to the case when both independent and dependent variables have errors. We apply this procedure to an effect of water physics, namely water aeration, with importance also to environmental and biological issues.
NEW INSIGHTS CONCERNING DIMENSION EIGHT EFFECTS IN WEAK DECAYS
Authors: DONOGHUE JOHN F.
Published: July 2002

Most past work on weak nonleptonic decays has mixed dimensional regularization in the weak operator product expansion with some form of a cutoff regularization in the evaluation of the matrix elements. Even with the usual technique of matching the two schemes, this combination misses physics at short distance which can be described by dimension eight (and higher dimension) operators. I describe some recent work with V. Cirigliano and E. Golowich which clarifies these effects and provides a numerical estimate suggesting that they are important.
THERMODYNAMICS OF GAUSSIAN FLUCTUATIONS AND PARACONDUCTIVITY IN LAYERED SUPERCONDUCTORS
Authors: MISHONOV TODOR , PENEV EVGENI
Published: July 2002

A detailed theoretical analysis of the Gaussian fluctuations of the order parameter in layered superconductors is performed within the Ginzburg–Landau (GL) theory. The available results for the Gaussian fluctuations are systematized and a number of novel formulae for the fluctuation magnetization, nonlinear magnetic susceptibility, heat capacity and high-frequency conductivity in layered superconductors are derived. We propose several new prescriptions: how to determine the life-time constant of fluctuation Cooper pairs τ0, the in-plane coherence length ξab(0), the energy cutoff parameter [Formula: see text] and the Ginzburg number ∊ Gi . It is demonstrated, for example, how the spectroscopy of the life-time can be used to verify the existence of depairing mechanisms in layered cuprates. The ultraviolet regularization of the GL free energy is carried out by means of the well-known from the field theory ζ-function method. We further show that the archetype of the latter method has its origin in the century of enlightenment and the novel result is that the fluctuation part of the thermodynamic variables of the layered superconductors can be expressed in terms of the Euler Γ-function and its derivatives. Universal scaling curves for the magnetic field dependence of the paraconductivity σab(T c ,B), fluctuation magnetization M(T c ,B) and the heat capacity C(T c ,B) are found for the quasi-2D superconductors at T c and further related to the form-factor of the Cooper pairs.
STUDY OF COMPLEX Cu-O LATTICE IN La8-xSrxCu8O20 BY HIGH RESOLUTION X-RAY ABSORPTION SPECTROSCOPY
Authors: SAINI N. L. , LANZARA A. , GARG K. B. , BIANCONI A. , ITO T. , OKA K. , OYANAGI H.
Published: July 2002

Cu K-edge XANES spectroscopy has been used to study local structure around the Cu-site in three-dimensional oxygen deficient perovkite La 8- x Sr x Cu 8 O 20 system. The combination of E//ab and E//c polarization and high resolution XANES spectra on high quality single crystals has allowed us to distinguish the various features associated with the complex Cu-O networks in the system which have then been compared with those of the La 2- x Sr x CuO 4 system.
COHERENT DESCRIPTION OF ELECTRICAL AND THERMAL IMPURITY–AND–PHONON LIMITED TRANSPORT IN SIMPLE METALS
Authors: AUSLOOS M. , DURCZEWSKI K. , ULNER J.
Published: July 2002

The electrical resistivity, thermoelectric power and electronic thermal conductivity of simple (isotropic) metals are studied in a uniform way. Starting from results of a variational solution of the Boltzmann equation, a generalized Matthiessen rule is used in order to superpose the inelastic (or not) electron–phonon and elastic electron–impurity scattering cross sections ("matrix elements"). The temperature dependence relative to these processes is given through simple functions and physical parameters over the usually investigated range of temperature for each transport coefficient. The coherence of such results is emphasized.
NEUTRON STARS: RECENT DEVELOPMENTS
Authors: HEISELBERG HENNING
Published: July 2002

Recent developments in neutron star theory and observation are discussed. Based on modern nucleon-nucleon potentials more reliable equations of state for dense nuclear matter have been constructed. Furthermore, phase transitions such as pion, kaon and hyperon condensation, superfluidity and quark matter can occur in cores of neutron stars. Specifically, the nuclear to quark matter phase transition and its mixed phases with intriguing structures are treated. Rotating neutron stars with and without phase transitions are discussed and compared to observed masses, radii and glitches. The observations of possible heavy ~2M⊙ neutron stars in X-ray binaries and quasi-periodic oscillations require relatively stiff equations of state and restrict strong phase transitions to occur at very high nuclear densities only.
SYNTHESIS AND CHARACTERIZATION OF TERNARY AL-C-N COMPOUND
Authors: JIANG N. , XU S. , OSTRIKOV K. N. , TSAKADZE E. L. , LONG J. D. , CHAI J. W. , TSAKADZE Z. L.
Published: July 2002

An attempt for modification of carbon nitride material by introduction of Al to form a ternary Al-C-N compound in a thin film deposited using inductively coupled plasma (ICP) assisted DC magnetron sputtering is reported. Optical emission spectroscopy (OES) is used for in-situ observation and identification of reactive species. The films were characterized using x-ray photoelectron spectroscopy (XPS) and x-ray diffraction spectroscopy (XRD). The results indicate that C-N bond is formed in the plasma. The XPS narrow scam spectra confirm the existence of C-Al, sp2C-N and sp3C-N bonds. Elemental proportion of carbon increases with the CH4/N2 flow rate ratio, and has a tendency to saturate. The film is dominated by c-AlN (111), mixed with Al4C3 and AlCN ternary compound.
RECENT DEVELOPMENTS IN STRONGLY INTERACTING LATTICE SYSTEMS
Authors: OITMAA J.
Published: July 2002

I give an overview of areas of recent and current research in the theoretical study of strongly interacting lattice systems, in the areas of lattice spin models (magnetism), lattice electron models (superconductivity) and lattice gauge models (elementary particles). The emphasis is on novel and interesting physics, and recent results.
IONIZATION AND STABILIZATION OF A ONE-DIMENSIONAL MODEL ATOM: MAP APPROACH
Authors: CHENG TAIWANG , LIU JIE , CHEN SHIGANG
Published: July 2002

In this paper, the interactions between a one-dimensional model atom and intense laser field is approximately described by a map. Both the classical version and quantum version of this map are studied. It is shown that besides classical stable islands which can bound some phase space region against ionization and then are responsible for the atomic stabilization, there is another structure in phase space, the unstable manifold, which can determine the ionization process of the system. Quantumly, the quantum quasienergy eigenstates (QE state) under absorptive boundaries, which directly related to the ionization process, are calculated. We define the QE state with smallest ionization rate as QE0 state, which represents the stabilization degree. The Wigner distribution of such QE0 state show clear fringe structures. Finally we show that the classical description and quantum description are in a correspondence manner.
Dissipation of Energy in a Concentric ER Clutch and its Refined Quasi-Static Model
Authors: Oravský Vladimír
Published: July 2002

A concentric electrorheological clutch (ERC) constituting the central part of a broader system: electro-hydro-aggregate (EHA) with an electrodrive (ED) on one side and a loading machine (brake B) on the other side is considered. The corresponding quasi-static model (at constant load and speed) is investigated and refined by insertion of power absorbed by electrorheological fluid (ERF). This increases the number of nondimensional parameters of the model from 8 to 12. Classification of several kinds of dissipation of energy in ERC is presented. Description and analysis of dissipation of the first kind are given more in detail and illustrated by synoptical diagrams. Also two definitions of efficiency of ERC are introduced and discussed.
APPLICATION OF THE SEKE SELF-CONSISTENT PROJECTION OPERATOR METHOD IN THE CASE OF A DISCRETIZED ATOM-FIELD INTERACTION MODEL
Authors: SEKE J. , SOLDATOV A. V. , BOGOLUBOV N. N.
Published: July 2002

The relaxation dynamics in the case of a discretized atom-field interaction model, being of great importance in quantum optics, is investigated numerically by an algorithm based on Seke's self-consistent projection operator method. The transition from reversible to irreversible dynamics in the continuous limit is simulated numerically. The dependence of the time evolution of atomic nondecay probability on the number of discrete-field modes, coupled to the atom, is discussed.
THEORY OF QUANTUM HALL EFFECT AND HIGH LANDAU LEVELS
Authors: SHRIVASTAVA KESHAV N.
Published: July 2002

The angular momentum model which couples the spin and charge is discussed as a possible theory of the quantum Hall effect. The high Landau level filling fractions 5/2, 7/3 and 8/3 are understood by this model. It is found that 7/3 and 8/3 are the particle–hole conjugates and 5/2 arises due to a limiting level at 1/2 with Landau level number n=5 which makes the fraction as 5/2.
THERMAL ZIPPER: IDEALIZED STATISTICAL MECHANICS OF CRACK FORMATION
Authors: MATTIS DANIEL C.
Published: July 2002

Cracks are known to form easily along certain crystallographic directions, presumably because of weaker bonds or lower coordination numbers along those directions. We uncover the manner in which such weak bonds break as the temperature is raised, by evaluating the partition function of an anisotropic grid in two dimensions of atoms with nearest-neighbor bonds.
A GENERALIZED MULTIPHOTON JAYNES–CUMMINGS MODEL FOR TWO COLLECTIVELY RADIATING ATOMS SOLVED VIA SUPERSYMMETRIC UNITARY TRANSFORMATION
Authors: LU HUAI-XIN , WANG XIAO-QIN , LIU HAN-JUN , ZHANG YONG-DE
Published: July 2002

The multiphoton Jaynes–Cummings model is theoretically generalized to the simplest case of collectively radiating atoms. For this Jaynes–Cummings model, we find its supersymmetric structure. Based on this, we introduce a supersymmetric unitary transformation to diagonalize the Hamiltonian, and in so doing, its eigenvalues and eigenfunctions are obtained. Some transition processes are calculated.
QUANTIZATION OF THE ONE-DIMENSIONAL FREE PARTICLE MOTION WITH DISSIPATION
Authors: LÓPEZ G. , MURGUÍA M. , SOSA M.
Published: July 2002

Using Schrödinger's quantization method, the Hamiltonian of a particle moving in a one-dimensional dissipative medium is quantized in a box of length L and at first order on dissipation strength. Expressions for ,
 and |ψ|2 are obtained in terms of the dissipation parameter. A treatment for the case of free particle motion with friction is presented.
EFFECTS OF INTERACTION WITH SOLVENT AND CHAIN CONFORMATION OF SURFACTANTS ON EMULSIFICATION
Authors: LIU HAO-YANG , ZOU XIAN-WU , YUAN YIN-QUAN , JIN ZHUN-ZHI
Published: July 2002

The details of the emulsification process has been investigated by discontinuous molecular dynamic simulation. The surfactants help to bring about emulsification. The emulsification can be divided crudely into two stages: splitting and uniting process. The splitting and uniting of oil droplets occurs in this position, where surfactants at the interface is rather scarce. The effects of the conformation of surfactant chain and the strength of surfactant–water and surfactant–oil interactions on emulsification were also studied. The surfactants with longer tail and stronger surfactant–water and surfactant–oil interactions promote the emulsification more.
QUANTUM-CLASSICAL CROSSOVER OF THE ESCAPE RATE IN THE NANO-FERROMAGNET WITH COMPLEX CRYSTAL SYMMETRY
Authors: PARK CHANG-SOO
Published: July 2002

We investigate the quantum-classical crossover of the escape rate in the nanoscale ferromagnetic particle with complex crystal symmetries placed in an external field along the hard anisotropy axis. We use the periodic instanton technique based on the spin coherent state representation and the condition of the first-order crossover to determine the type of crossover. In the high field limit of ∊(=1-Hc/H)→0 the crossover is found to be second-order. We also calculate the crossover temperature with leading order behavior of T0~∊1/2.
MORPHOMETRIC ANALYSIS OF HUMAN CORNEAL ENDOTHELIUM BY MEANS OF SPATIAL POINT PATTERNS
Authors: DOMINGO JUAN , AYALA GUILLERMO , DÍAZ MARÍA ELENA
Published: July 2002

This paper presents a method for detecting abnormalities in spatial arrangements of cells within any tissue that can be described by different sets of relevant points. The method has been applied to the detection of subtle abnormalities in corneal endothelia. Images of this type of tissue can be characterized by two types of points: cell centroids and triple points associated with the apical intersections as it was proposed by Díaz.7 Both types of points jointly considered are modeled using a bivariate spatial point process; then a statistical analysis based on certain distributional descriptors proposed by Doguwa4,9 is carried out to discriminate severe and subtle abnormalities from controls. According to the results, the method constitutes a valid alternative to currently used techniques, which involve statistical descriptions of cell density, cell area and hexagonality, that fail in the detection of these subtle abnormalities.
BAYESIAN VIDEO MOSAICING WITH MOVING OBJECTS
Authors: BARCELÓ LLUIS , BINEFA XAVIER
Published: July 2002

This paper presents a framework that creates background, foreground and a temporal summarization of the motions in a scene. The method is based on the Dominant Motion Assumption (DMA), where the background has a parametric motion and occupies the main part of the scene. Under this assumption, we present a robust optical flow based method to extract the moving parts of the scene using the clustering capabilities of mixtures of Gaussians. A general mosaicing method to summarize the background, the foreground and the trajectories of objects in the scene is also presented.
FRACTURE IN COMPOSITES IN A NONLINEAR DYNAMIC SCHEME
Authors: TONELLI ROBERTO , MELONI FRANCO , AYMERICH FRANCESCO
Published: July 2002

We consider the fracture of a fibre reinforced graphite peek polymer when an axial periodical fatigue is applied. The energy-time diagram shows various critical points during the cyclic tensile loading. An analysis of the temporal series in the representative phase space, in terms of fractal and embedding dimension, enhances some properties not revealed by the standard engineering approach. In particular, variation of the correlation dimension before fracture may be used as a useful indicator for the subsequent breakdown.
PROPER WEAKLY LEFT AMPLE SEMIGROUPS
Authors: GOMES GRACINDA M. S. , GOULD VICTORIA
Published: July 2002

Much of the structure theory of inverse semigroups is based on constructing arbitrary inverse semigroups from groups and semilattices. It is known that E-unitary (or proper) inverse semigroups may be described as P-semigroups (McAlister), or inverse subsemigroups of semidirect products of a semilattice by a group (O'Carroll) or Cu-semigroups built over an inverse category acted upon by a group (Margolis and Pin). On the other hand, every inverse semigroup is known to have an E-unitary inverse cover (McAlister).

The aim of this paper is to develop a similar theory for proper weakly left ample semigroups, a class with properties echoing those of inverse semigroups. We show how the structure of semigroups in this class is based on constructing semigroups from unipotent monoids and semilattices. The results corresponding to those of McAlister, O'Carroll and Margolis and Pin are obtained.
THE ORIGIN OF SCALE–SCALE CORRELATIONS OF THE DENSITY PERTURBATIONS DURING INFLATION
Authors: FANG LI-ZHI , LEE WOLUNG , PANDO JESÚS
Published: July 2002

We show that scale–scale correlations are a generic feature of slow-roll inflation theories. These correlations result from the long-time tails characteristic of the time dependent correlations because the long wavelength density perturbation modes are diffusion-like. A relationship between the scale–scale correlations and time-correlations is established providing a way to reveal the time correlations of the perturbations during inflation. This mechanism provides for a testable prediction that the scale–scale correlations at two different spatial points will vanish.
GLOBAL DYNAMICS AND CONTROLLABILITY OF A HARVESTED PREY-PREDATOR SYSTEM
Authors: SRINIVASU P. D. N. , ISMAIL SHAIK , NAIDU CH. RAGHAVENDRA
Published: July 2002

In this paper we have considered a prey-predator model with Holling type of predation and independent harvesting in either species. The purpose of the work is to offer mathematical analysis of the model and to discuss some significant qualitative results that are expected to arise from the interplay of biological forces. Our study shows that, using the harvesting efforts as controls, it is possible to break the cyclic behaviour of the system and drive it to a required state. Also it is possible to introduce globally stable limit cycle in the system using the above controls.
QUALITATIVE ANALYSIS FOR THE MERKIN ENZYME REACTION SYSTEM
Authors: WANG YUQUAN , SHEN ZUORUI
Published: July 2002

Applying qualitative theory and Hopf bifurcation theory, we detailedly discuss the Merkin enzyme reaction system, and the sufficient conditions derived for the global stability of the unique positive equilibrium, the local stability of three equilibria and the existence of limit cycles. Meanwhile, we show that the Hopf bifurcations may occur. Using MATLAB software, we present three examples to simulate these conclusions in this paper.
MAKING NEW DIGITS IN THE APLASTIC HAND
Authors: Pho Robert W.H.
Published: July 2002

This paper reviews the various techniques and procedures available for reconstruction of the digits to restore form and function in the aplastic hand. The author presents his own experience and discusses future trends in the management of missing digits.
CONSTRUCTING A PERSONAL WEB MAP WITH ANYTIME-CONTROL OF WEB ROBOTS
Authors: YAMADA SEIJI , NAGINO NORIKATSU
Published: July 2002

In this paper, we propose a [Formula: see text] (Personal Web Map) which is a personal and small database of interesting Web pages to a user and develop a method to construct it under the user's control of multiple Web robots. While general search engines with very large databases are valid for information retrieval in the WWW, it is still important that a user constructs a small, personal database of relevant Web pages to his/her interest. For such a Web page database, we propose a [Formula: see text] and develop a [Formula: see text] system. First a user gives keywords indicating his/her interest to a system, and it constructs a [Formula: see text] concerned with the keywords. For building a useful [Formula: see text], it is necessary that a user can interrupt the construction of a [Formula: see text] anytime and instruct a sub-field which should be explored more. For this function, we develop an anytime-control algorithm for multiple Web robots. A density blackboard is used for controlling Web robots, and an uniform distributed [Formula: see text] is built. Whenever a system is interrupted by a user, it provides a valid [Formula: see text] in terms of keeping search space wide, and indicates many alternatives on which he/she wants more information. From Web pages in a database, document vectors are generated and used to construct a 2D-map of a [Formula: see text] by using self-organization maps. A user easily recognizes interim results through the 2D-map, and gives instruction by clicking a node about which he/she wants more detail information. We made experiments by subjects and found out that our method outperformed breadth-first search for constructing a useful [Formula: see text]. As results, a [Formula: see text] system is considered as a promising approach to assist a user in gathering relevant information in the WWW.
Putting innovation to work
Authors: Francik Ellen , Rudman Susan Ehrlich , Cooper Donna , Levine Stephen
Published: July 2002

Multimedia communication systems promise better support for widely distributed workgroups. Their benefits for complex communication—problem-solving, negotiating, planning, and design —seem obvious, introducing appealing new technologies into the marketplace, however, can require years of Investment [13, 22]. In particular, finding productive uses for new systems takes time. Adoption strategies are needed to guide and accelerate the process.
Capturing, structuring, and representing ubiquitous audio
Authors: Hindus Debby , Schmandt Chris , Horner Chris
Published: July 2002

Although talking is an integral part of collaboration, there has been little computer support for acquiring and accessing the contents of conversations. Our approach has focused on
ubiquitous audio
, or the unobtrusive capture of speech interactions in everyday work environments. Speech recognition technology cannot yet transcribe fluent conversational speech, so the words themselves are not available for organizing the captured interactions. Instead, the structure of an interaction is derived from acoustical information inherent in the stored speech and augmented by user interaction during or after capture. This article describes applications for capturing and structuring audio from office discussions and telephone calls, and mechanisms for later retrieval of these stored interactions. An important aspect of retrieval is choosing an appropriate visual representation, and this article describes the evolution of a family of representations across a range of applications. Finally, this work is placed within the broader context of desktop audio, mobile audio applications, and social implications.
Graphical representation of programs in a demonstrational visual shell—an empirical evaluation
Authors: Modugno Francesmary , Corbett Albert T. , Myers Brad A.
Published: July 2002

An open question in the area of Programming by Demonstration (PBD) is how to best represent the inferred program. Without a way to view, edit, and share programs, PBD systems will never reach their full potential. We designed and implemented two graphical representation languages for a PBD desktop similar to the Apple Macintosh Finder. Although a user study showed that both languages enabled nonprogrammers to generate and comprehend programs, the study also revealed that the language that more closely reflected the desktop domain doubled users' abilities to accurately generate programs. Trends suggest that the same language was easier for users to comprehend. These findings suggest that it is possible for a PBD system to enable nonprogrammers to construct programs and that the form of the representation can impact the PBD system's effectiveness. A paper-and-pencil evaluation of the two versions of the PBD desktop prior to the study supported these finding and provided interesting feedback on the interaction between usability evaluations and user studies. In particular, the comparison of the paper-and-pencil evaluation with the empirical evaluation suggested that nonempirical evaluation techniques can provide guidance into how to interpret empirical data and, in particular, that PBD systems need to provide support for programming-strategy selection in order to be successful.
The weighted spectral test
Authors: Hellekalek Peter , Niederreiter Harald
Published: July 2002

In this article, we present a new approach to assessing uniform random number generators, the
weighted spectral test
, or
diaphony
. In contrast to the usual
spectral test
the weighted spectral test is not limited to random number generators with a lattice structure. Its computational complexity is
O
(s·N
2
) for any point set of cardinality
N
in the s-dimensional unit cube. As the main results of this article, we prove an analog of the classical inequality of Erdös-Turán-Koksma, present the necessary tools to transcribe known discrepancy bounds into bounds for diaphony, and provide bounds for the diaphony of multiplicative congruetial pseudorandom numbers. The last section contains numerical results.
Graphical definitions
Authors: Burnett Margaret M. , Gottfried Herkimer J.
Published: July 2002

In the past, attempts to extend the spreadsheet paradigm to support graphical objects, such as colored circles or user-defined graphical types, have led to approaches featuring
either
a direct way of creating objects graphically
or
strong compatibility with the spreadsheet paradigm, but not both. This inability to conveniently go beyond numbers and strings without straying outside the spreadsheet paradigm has been a limiting factor in the applicability of spreadsheet languages. In this article we present graphical definitions, an approach that removes this limitation, allowing both simple and complex graphical objects to be programmed directly using direct manipulation and gestures, in a manner that fits seamlessly within the spreadsheet paradigm. We also describe an empirical study, in which subjects programmed such objects faster and with fewer errors using this approach than when using a traditional approach to formula specification. Because the approach is expressive enough to be used with both built-in and user-defined types, it allows the directness of demonstrational and spreadsheet techniques to be used in programming a wider range of applications than has been possible before.
Database design with common sense business reasoning and learning
Authors: Storey Veda C. , Chiang Roger H. L. , Dey Debabrata , Goldstein Robert C. , Sudaresan Shankar
Published: July 2002

Automated database design systems embody knowledge about the database design process. However, their lack of knowledge about the domains for which databases are being developed significantly limits their usefulness. A methodology for acquiring and using general world knowledge about business for database design has been developed and implemented in a system called the Common Sense Business Reasoner, which acquires facts about application domains and organizes them into a a hierarchical, context-dependent knowledge base. This knowledge is used to make intelligent suggestions to a user about the entities, attributes, and relationships to include in a database design. A distance function approach is employed for integrating specific facts, obtained from individual design sessions, into the knowledge base (learning) and for applying the knowledge to subsequent design problems (reasoning).
Arabic word processing
Authors: Becker Joseph D.
Published: July 2002

Recently developed word processing software can correctly format the cursive, interacting letters of the Arabic script. Moreover, new layout procedures can automatically intermix right-to-left Arabic writing with left-to-right text in European or other languages.
Analysis of Graphs by Connectivity Considerations
Authors: Ramamoorthy C. V.
Published: July 2002

Discrete sequential systems, such as sampled data systems, discrete Markov processes, linear shift register generators, computer programs, sequential code generators, and prefixed comma-free codes, can be represented and studied in a uniform manner by directed graphs and their generating functions. In this paper the properties of the generating functions are examined from certain connectivity considerations of these graphs.
Nondeterministic Algorithms
Authors: Floyd Robert W.
Published: July 2002

Programs to solve combinatorial search problems may often be simply written by using multiple-valued functions. Such programs, although impossible to execute directly on conventional computers, may be converted in a mechanical way into conventional backtracking programs. The process is illustrated with algorithms to find all solutions to the eight queens problem on the chessboard, and to find all simple cycles in a network.
Enumerating full-time programmers
Authors: Gilchrist Bruce , Weber Richard E.
Published: July 2002

Data from the 1970 Census and the Department of Labor's Area Wage Surveys are used to derive estimates of the number of full-time programmers employed during the years 1969 through 1973. The 1973 figure of 180,000 is considerably less than suggested in earlier reports. It is recommended that educational administrators consider whether the many courses aimed at training programmers are justified on a vocational basis.
Solution of a problem in concurrent programming control
Authors: Dijkstra E. W.
Published: July 2002

A number of mainly independent sequential-cyclic processes with restricted means of communication with each other can be made in such a way that at any moment one and only one of them is engaged in the “critical section” of its cycle.
Performance of rollback recovery systems under intermittent failures
Authors: Gelenbe E. , Derochette D.
Published: July 2002

A mathematical model of a transaction-oriented system under intermittent failures is proposed. The system is assumed to operate with a checkpointing and rollback/recovery method to ensure reliable information processing. The model is used to derive the principal performance measures, including availability, response time, and the system saturation point.
On-the-fly garbage collection
Authors: Dijkstra Edsger W. , Lamport Leslie , Martin A. J. , Scholten C. S. , Steffens E. F. M.
Published: July 2002

As an example of cooperation between sequential processes with very little mutual interference despite frequent manipulations of a large shared data space, a technique is developed which allows nearly all of the activity needed for garbage detection and collection to be performed by an additional processor operating concurrently with the processor devoted to the computation proper. Exclusion and synchronization constraints have been kept as weak as could be achieved; the severe complexities engendered by doing so are illustrated.
Interactive skeleton techniques for enhancing motion dynamics in key frame animation
Authors: Burtnyk N. , Wein M.
Published: July 2002

A significant increase in the capability for controlling motion dynamics in key frame animation is achieved through skeleton control. This technique allows an animator to develop a complex motion sequence by animating a stick figure representation of an image. This control sequence is then used to drive an image sequence through the same movement. The simplicity of the stick figure image encourages a high level of interaction during the design stage. Its compatibility with the basic key frame animation technique permits skeleton control to be applied selectively to only those components of a composite image sequence that require enhancement.
The state of computer oriented curricula in business schools 1970
Authors: McKenney J. L. , Tonge F. M.
Published: July 2002

The ACM Committee on Computer Education for Management, supported by a National Science Foundation Grant, is established to appraise the state of the art and to develop a series of recommendations for improving computer education for management. To provide the Committee with material for its study of curricular needs, five regional meetings in the United States were held in 1970, at each of which a broad cross section of invited academicians and practitioners considered the state of curricula in business schools. Three topics were covered: curricula for the general manager; computer-related material in required and functional courses; and curricula for students concentrating on computer-based information systems.

An analysis of the minutes of the meetings revealed a common set of experiences which raised similar pedagogic and economic issues. This presentation gives a summary of the discussions; a condensation of the pedagogic and substantive concerns raised; and consideration of the resource allocation issues involved.

Preliminary to the Committee's recommendations for improving computer education for management, this report has been prepared to provide the participants and the administrators of their institutions with background information for the ongoing task of course development.

Chairman of the ten-man Committee is Daniel Teichroew (The University of Michigan).