bluuebunny/crossref_metadata_2025 huggingface dataset:
High Specific Infectivity of Plasma Virus from the Pre-Ramp-Up and Ramp-Up Stages of Acute Simian Immunodeficiency Virus Infection
Authors: Ma Zhong-Min , Stone Mars , Piatak Mike , Schweighardt Becky , Haigwood Nancy L. , Montefiori David , Lifson Jeffrey D. , Busch Michael P. , Miller Christopher J.
Published: January 2009

To define the ratio of simian immunodeficiency virus (SIV) RNA molecules to infectious virions in plasma, a ramp-up-stage plasma pool was made from the earliest viral RNA (vRNA)-positive plasma samples (collected approximately 7 days after inoculation) from seven macaques, and a set-point-stage plasma pool was made from plasma samples collected 10 to 16 weeks after peak viremia from seven macaques; vRNA levels in these plasma pools were determined, and serial 10-fold dilutions containing 1 to 1,500 vRNA copies/ml were made. Intravenous (i.v.) inoculation of a 1-ml aliquot of diluted ramp-up-stage plasma containing 20 vRNA copies infected 2 of 2 rhesus macaques, while for the set-point-stage plasma, i.v. inoculation with 1,500 vRNA copies was needed to transmit infection. Further, when the heat-inactivated set-point-stage plasma pool was mixed with ramp-up-stage virions, infection of inoculated macaques was blocked. Notably, 2 of 2 animals inoculated with 85 ml of a pre-ramp-up plasma pool containing <3 SIV RNA copies/ml developed SIV infections characterized by high levels of viral replication, demonstrating that “vRNA-negative” plasma collected from macaques in the pre-ramp-up stage is infectious. Furthermore, there is a high ratio of infectious virions to total virions in ramp-up-stage plasma (between 1:1 and 1:10) and a lower ratio in set-point-stage plasma (between 1:75 and 1:750). Heat-inactivated chronic-stage plasma can “neutralize” the highly infectious ramp-up-stage virions. These findings have implications for the understanding of the natural history of SIV and human immunodeficiency virus infection and transmission.
WELL POSEDNESS FOR A PHASE TRANSITION MODEL IN SUPERCONDUCTIVITY WITH VELOCITY AND MAGNETIC CRITICAL FIELDS
Authors: BERTI V. , FABRIZIO M.
Published: January 2009

In this paper we present a Ginzburg–Landau model to describe the phenomenon of superconductivity as a second-order phase transition. The model proposed, which also includes thermal effects, allows to explain the existence of threshold values, both of the magnetic field and of the superconducting current, beyond which superconductivity vanishes. This is achieved by introducing a constitutive equation for the magnetic induction where the magnetic permeability depends on the complex order parameter. The model is proved to be consistent with thermodynamical principles. The resulting differential system is studied under the assumption that the temperature is a fixed parameter and its well-posedness is proved.
AN EXISTENCE AND UNIQUENESS RESULT FOR AN ELASTO-PIEZOELECTRIC PROBLEM WITH DAMAGE
Authors: FERNÁNDEZ JOSÉ R. , KUTTLER KENNETH L.
Published: January 2009

The aim of this paper is to study the damage evolution in an elasto-piezoelectric body. The effect of the damage, due to internal tension or compression and caused by the opening and growth of micro-cracks and micro-cavities, and the piezoelectric effects are included into the model. The variational formulation leads to a coupled system of evolutionary equations. An existence and uniqueness result is then proved by using the theory of maximal monotone operators, the Schauder fixed-point theorem, and a comparison result.
LOWER ORDER RECTANGULAR NONCONFORMING MIXED FINITE ELEMENT FOR THE THREE-DIMENSIONAL ELASTICITY PROBLEM
Authors: MAN HONG-YING , HU JUN , SHI ZHONG-CI
Published: January 2009

In this paper, we propose a first-order rectangular nonconforming element for the stress-displacement system derived from the Hellinger–Reissner variational principle for the three-dimensional elasticity problem. We show that the discrete inf–sup condition holds for this scheme. Based on some superconvergence of the consistency error, we prove the optimal error estimate of [Formula: see text] for both the displacement and stress.
HIGHER ORDER ENTROPIES FOR COMPRESSIBLE FLUID MODELS
Authors: GIOVANGIGLI VINCENT
Published: January 2009

We investigate higher order entropies for compressible fluid models and related a priori estimates. Higher order entropies are kinetic entropy estimators suggested by Enskog expansion of Boltzmann entropy. These quantities are quadratic in the density ρ, velocity v, and temperature T renormalized derivatives. We investigate governing equations of higher order entropy correctors and related differential inequalities in the natural situation where the volume viscosity, the shear viscosity, and the thermal conductivity depend on temperature, essentially in the form Tϰ, as given by the kinetic theory of gases. Entropic inequalities are established when ‖ log ρ‖ BMO , [Formula: see text], ‖ log T‖ BMO , ‖h∂x ρ/ρ ‖L∞, [Formula: see text], ‖ h∂xT/T‖L∞, and [Formula: see text] are small enough, where [Formula: see text] is a weight associated with the dependence of the local mean free path on density and temperature. As an example of application, we investigate global existence of solutions when the initial values log (ρ0/ρ∞), [Formula: see text], and log (T0/T∞) are small enough in appropriate spaces.
DIPOLE-EXCHANGE SPIN WAVES IN FERROMAGNETIC NANOSTRUCTURES WITH SPHERICAL GEOMETRIES
Authors: NGUYEN HOA T. , COTTAM M. G.
Published: January 2009

Dipole–exchange spin waves (SWs) are studied in ferromagnetic nanostructures with spherical geometries such as spheres, part spheres, and spherical shells, both individually and in finite-sized arrays. A microscopic theory is used based on a spin Hamiltonian, which incorporates the short-range exchange and long-range magnetic dipole–dipole interactions, as well as an external magnetic field applied in any direction. Our theory is advantageous for describing the dynamical properties of inhomogeneously magnetized samples, and the use of phenomenological boundary conditions is avoided. Numerical results are deduced for the frequencies of the discrete SW modes and their dependence on the radius, spacing between particles, applied field, etc. Applications are made to Permalloy Fe 19 Ni 81 and alloy Co 80 Ni 20 nanoparticles with their sizes varying from 10 to 100 nm. Through a Green function theory, the spatial distributions and spectral intensities of the SWs are also deduced. The mode-mixing (hybridization) effects on the SW branches are found to be important, depending on the particle sizes and geometries.
KINETICS OF ELECTROCHEMICAL REACTIONS ON MODEL SUPPORTED CATALYSTS: READSORPTION AND MASS TRANSPORT
Authors: ZHDANOV VLADIMIR P. , KASEMO BENGT
Published: January 2009

To bridge the structure gap, electrochemical reactions can be studied in flow cells with nm-sized catalyst particles deposited or fabricated on the cell walls. The understanding of the role of mass transport in such cells is now limited. To clarify the likely effects in this field, we analyze the simplest reaction scheme including intermediate desorption, readsorption, and subsequent reaction and show how the net rate of the formation of intermediate can be influenced by its diffusion in the liquid phase. With certain approximations, we derive analytical results describing reaction and diffusion near catalyst particles and in more remote regions in the simplest 1D case and more complex 2D and 3D situations.
SURFACE PLASMON POLARITON LOCALIZATION
Authors: COELLO VICTOR
Published: January 2009

Localization of surface plasmons polariton is reviewed in the context of experiments and modeling of near-field optical images. Near-field imaging of elastic (in-plane) surface plasmon scattering is discussed, and approaches for the correct image interpretation are outlined. Nonlinear effects related to localized surface plasmons are pressented. Surface plasmon localization opens up numerous possibilities for application in biosensing, nanophotonics, and in general in the area of surface optics properties.
HYDROPHILIZATION OF POLYVINYL CHLORIDE SURFACE BY OZONATION
Authors: KUROSE KEISUKE , OKUDA TETSUJI , NAKAI SATOSHI , TSAI TSUNG-YUEH , NISHIJIMA WATARU , OKADA MITSUMASA
Published: January 2009

The surface modification mechanism of polyvinyl chloride (PVC) by ozonation was investigated to study the selective hydrophilization of PVC surface among other plastics. Infrared analysis confirmed the increase of hydrophilic groups. XPS analysis revealed that the increase was due to the structural change in chlorine group in PVC to hydroxylic acid, ketone, and carboxylic groups by ozonation. This chemical reaction by ozone could occur only for polymers with chlorides in its structure and resulted in the selective hydrophilization of PVC among various polymers.
IN SITU SCANNING TUNNELING MICROSCOPY TOPOGRAPHY CHANGES OF GOLD (111) IN AQUEOUS SULFURIC ACID PRODUCED BY ELECTROCHEMICAL SURFACE OXIDATION AND REDUCTION AND RELAXATION PHENOMENA
Authors: PASQUALE M. A. , NIETO F. J. RODRÍGUEZ , ARVIA A. J.
Published: January 2009

The electrochemical formation and reduction of O -layers on gold (111) films in 1 m sulfuric acid under different potentiodynamic routines are investigated utilizing in situ scanning tunneling microscopy. The surface dynamics is interpreted considering the anodic and cathodic reaction pathways recently proposed complemented with concurrent relaxation phenomena occurring after gold (111) lattice mild disruption (one gold atom deep) and moderate disruption (several atoms deep). The dynamics of both oxidized and reduced gold topographies depends on the potentiodynamic routine utilized to form OH / O surface species. The topography resulting from a mild oxidative disruption is dominated by quasi-2D holes and hillocks of the order of 5 nm, involving about 500–600 gold atoms each, and their coalescence. A cooperative turnover process at the O -layer, in which the anion ad-layer and interfacial water play a key role, determines the oxidized surface topography. The reduction of these O -layers results in gold clusters, their features depending on the applied potential routine. A moderate oxidative disruption produces a surface topography of hillocks and holes several gold atoms high and deep, respectively. The subsequent reduction leads to a spinodal gold pattern. Concurrent coalescence appears to be the result of an Ostwald ripening that involves the surface diffusion of both gold atoms and clusters. These processes produce an increase in surface roughness and an incipient gold faceting. The dynamics of different topographies can be qualitatively explained employing the arguments from colloidal science theory. For 1.1 V ≤ E ≅ E pzc weak electrostatic repulsions favor gold atom/cluster coalescence, whereas for E < E pzc the attenuated electrostatic repulsions among gold surfaces stabilize small clusters over the substrate producing string-like patterns.
COTTON FABRIC PROPERTIES WITH WATER-REPELLENT FINISHING VIA SOL–GEL PROCESS
Authors: WANG CHAOXIA , LI MAO , WU MIN , CHEN LI
Published: January 2009

The properties of the cotton fabric with water-repellence finishing by sol method with the hexadecyltrimethoxysilane as additive were observed. The cotton fabrics were immersed in the prepared sols with double dip and double nip dried at 90°C, annealed at 160°C for 3 min. The water repellence and the physical properties such as gas permeability, bending properties, beetling properties, tensile strength, elongation at break, abrasion resistance, and anti-crease properties of the cotton fabrics were investigated. The results showed that anti-crease and tensile strength were improved. However, the abrasion resistance of the cotton fabrics decreased in some way. Both the bending and beetling properties measurement proved that the handle of the treated cotton fabrics changed stiffness. For the dyed fabrics by the water-repellent finishing, the hue was slightly changed, the deeper color was achieved. There is no adverse effect for treated fabric by water-repellent finishing on the fastness.
MORPHOLOGY AND ELECTRICAL RESISTIVITY OF AuCu NANOFILM ALLOYS
Authors: MALDONADO R. D. , OLIVA A. I.
Published: January 2009

Au / Cu thin films (33–320 nm thickness) were deposited by thermal evaporation on p-type silicon (100) substrates. Two groups of these bimaterial films were alloyed into a vacuum oven by diffusion. The first group was prepared with 24% Au atomic concentration (i.e. 33, 96, 158, 224, and 320 nm as AuCu total thickness). The second group was prepared changing the Au atomic concentration from 10% to 90%, with 10% Au steps and similar total thickness (100 nm). Prepared alloys were characterized with atomic force microscopy (AFM), scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), X-ray diffraction (XRD), and collinear four-probe techniques in order to obtain their morphology, stoichiometry, crystalline structure, and electrical resistivity, respectively. Particularly, electrical resistivity presented abrupt changes with the atomic concentration and the annealing temperature with important differences as compared with pure Au and Cu thin films.
SPECTROSCOPIC CHARACTERIZATIONS OF NONAMPHIPHILIC 2,5-BIS (5-TERT-BUTYL-BENZOXAZOLYL)-THIOPHENE MOLECULES AT THE AIR–WATER INTERFACE AND IN LANGMUIR–BLODGETT FILMS
Authors: BISWAS S. , HUSSAIN SYED ARSHAD , BHATTACHARJEE D.
Published: January 2009

This paper reports the π–A isotherm and spectroscopic characterizations of mixed Langmuir and Langmuir–Blodgett films of a nonamphiphilic thiophene derivative, namely, 2,5-Bis (5-tert-butyl-benzoxazolyl)-thiophene (BBOT) molecules, mixed with polymethyl methacrylate (PMMA) and stearic acid (SA). The π–A isotherms and molefraction vs. area per molecule studies indicate some repulsive interaction between sample (BBOT) and matrix (PMMA or SA) molecules. At higher surface pressure in the SA mixed BBOT Langmuir monolayer, a phase transition occurs, which has been revealed by π–A isotherm studies. UV-vis absorption and fluorescence spectroscopic studies confirm this phase transition and closer association of BBOT molecules. Spectroscopic studies of LB films lifted at higher surface pressure clearly confirm the presence of dimmers and higher-order n-meric sites.
SIMULATION OF MINIMUM ICE UNIT AND ITS EFFECT ON WATER PROPERTIES
Authors: PENG CHANGSHENG , SONG SHAOXIAN
Published: January 2009

The formation of a minimum ice unit (MIU) and ice crystal is simulated. The simulation indicates that an MIU is made up of 10 H 2 O molecules, and the MIU shows a four-hexagon cage structure. On the basis of simulation, we can calculate that 1 mol ice crystal contains 2 mol hydrogen bonds, and 16.67% hydrogen bonds should be broken during water fusion at 0°C. A total of 12.5% hydrogen bonds should be broken when 1 mol water is heated from 0°C to 100°C, and 70.83% hydrogen bonds should be broken when 1 mol water is vaporized into steam at 100°C. A total of 8.33% volume contract during water fusion at 0°C can also be calculated according to the MIU simulation in this paper.
ADHESIVE WEAR PERFORMANCE OF CFRP MULTILAYERED POLYESTER COMPOSITES UNDER DRY/WET CONTACT CONDITIONS
Authors: DANAELAN D. , YOUSIF B. F.
Published: January 2009

The tribo-performance of a new engineering composite material based on coconut fibers was investigated. In this work, coconut fibers reinforced polyester (CFRP) composites were developed. The tribo-experiments were conducted by using pin-on-disc machine under dry and wet sliding contact condition against smooth stainless steel counterface. Worn surfaces were observed using optical microscope. Friction coefficient and specific wear rate were presented as a function of sliding distance (0–0.6 km) at different sliding velocities (0.1–0.28 m/s). The effect of applied load and sliding velocity was evaluated. The results showed that all test parameters have significant influence on friction and wear characteristics of the composites. Moreover, friction coefficient increased as the normal load and speed increased, the values were about 0.7–0.9 under dry contact condition. Meanwhile, under wet contact condition, there was a great reduction in the friction coefficient, i.e. the values were about 0.1–0.2. Furthermore, the specific wear rates were found to be around 2–4 (10-3) mm3/Nm under dry contact condition and highly reduced under wet condition. In other words, the presence of water as cleaner and polisher assisted to enhance the adhesive wear performance of CFRP by about 10%. The images from optical microscope showed evidence of adhesive wear mode with transition to abrasive wear mode at higher sliding velocities due to third body abrasion. On the other hand, optical images for wet condition showed less adhesive wear and smooth surfaces.
INFLUENCE OF THE REACTION TEMPERATURE ON THE OSCILLATORY BEHAVIOR DURING PARTIAL OXIDATION OF METHANE
Authors: REN XIU-BIN , GUO XIANG-YUN
Published: January 2009

The oscillatory behavior during partial oxidation of methane was studied by the Monte Carlo simulation with Langmuir–Hinshelwood mechanism and oxide formation and removal. The well-developed reaction rate oscillations can be observed when the CH 4 adsorption probability varies in a small window. The oscillation window is very sensitive to the variation of reaction temperature. When the temperature increases, the window for sustained oscillation becomes narrow and has an obvious shift. In the meantime, the oscillation period tends to become small and the amplitude decreases. When the temperature increases to a certain value, the oscillations will disappear.
ON THE POSSIBILITY OF SMALL Mn CLUSTERS HAVING CUBIC SYMMETRY AND THEIR MAGNETIC MOMENTS
Authors: LEE KEEYUNG
Published: January 2009

Possibility of cubic structures in small manganese ( Mn ) clusters has been studied using the linear combination of Gaussian orbitals (LCGO) method. Local spin density approximation is adopted for the exchange correlation potential. Both high-spin and low-spin states are found for Mn 13 and Mn 19 clusters with the face-centered cubic symmetry; however, no equilibrium lattice constant could be found. For Mn 9 and Mn 15 clusters with the body-centered cubic symmetry, only high-spin states are found. No equilibrium lattice constant could be found for bcc Mn 9; however, a weak possibility of bcc structure in Mn 15 is found. The calculated magnetic moment of Mn 15 is, however, found to be too large compared with the experimental result.
NUCLEATION, GROWTH, AND MORPHOLOGICAL PROPERTIES OF ELECTRODEPOSITED NICKEL FILMS FROM DIFFERENT BATHS
Authors: SAHARI A. , AZIZI A. , SCHMERBER G. , DINIA A.
Published: January 2009

The processes of nickel electrodeposition on Pt / Si (100) substrate from an aqueous sulfate, Watts, and chloride solution have been studied using electrochemical techniques and atomic force microscopy (AFM). It was found that hydrogen evolution reaction (HER) was shifted more cathodically and the nickel electrodeposition obeys to inhibition process, caused by adsorbed species in surface substrate. At early stage of the deposition chronoamperometric results were compared with Sharifker and Hills theoretical model. The nucleation was in agreement with progressive mode followed by 3D diffusion growth mechanism. The nucleation is generally slow at low over potentials, in all studied baths. AFM images show distribution nickel clusters, with different sizes.
SIZE AND SURFACE EFFECT OF GOLD NANOPARTICLES (AuNPs) IN NANOGOLD-ASSISTED PCR
Authors: HUANG JIEHUAN , ZHANG XIAODONG , WANG CHUNMEI , WANG LIHUA , LI HAIKUO , CAO XUEYAN , ZHANG AILI , LI XUELING , FAN CHUNHAI , HU JUN
Published: January 2009

Recently, gold nanoparticles ( AuNPs ) were reported to increase the specificity and efficiency of the polymerase chain reaction (PCR). In this paper, we tested the enhancement of AuNPs with five different sizes on the specificity of two-round PCR. The results showed that, except 5.02 nm AuNPs , the AuNPs that could achieve the similar enhancement happened to have nearly the same total surface area. The surface effect seems to be the key factor of nanogold-assisted PCR.
ROLE OF SOLVENT IN SLURRY PHASE REACTIONS
Authors: ZHOU YAN , HU KAI , SHEN JUNFENG , JI ZHENPING , CHENG GONGZHEN
Published: January 2009

There exists an optimal amount of solvent (generally water) that can be added to the slurry phase reaction between solid reactants; the reactivity and efficiency of such reactions are different from those without solvent or those with large amount of solvent. Obviously, the solvent plays a crucial role in the process of the reaction, and it is the key to the understanding of unique reactivity and high efficiency of such slurry phase reactions. The water molecule absorbed on the surface of solid reactants, which is called bound water, has uniquely different properties compared with bulk water. Surface hydroxylation resulting from bound water greatly influences the chemical activity of the surface, which could be playing a role as catalyst or as the initialization point for further reactions, so that the reactants can react easily and fast under a simple reaction condition.
EFFECT OF THE C2H2 AND N2 FLOW RATE ON NANOCOMPOSITE nc-ZrCN/a-C:H(N) FILM SYNTHESIZED BY FILTERED CATHODIC VACUUM ARC TECHNIQUE
Authors: ZHOU KUI , WU XIANYING , ZHANG XU , QIN LIZHAO , LIAO BIN
Published: January 2009

Nanocomposite nc - ZrCN / a - C : H(N) films were prepared by filtered cathodic vacuum arc technique using the C 2 H 2 and N 2 gas as the precursor. The effect of the C 2 H 2 and N 2 flow rate on the microstructure, internal stress, phase composition, and mechanical properties of nanocomposite nc - ZrCN / a - C : H(N) films has been investigated by glancing incidence X-ray diffraction (GIXRD), surface profiler, and X-ray photoelectron spectroscopy(XPS). It was revealed that the C 2 H 2 and N 2 flow rate affected the structure, Zr content, and internal stress of the films significantly. Furthermore, XRD pattern indicated the presence of the ZrCN crystalline grains in the range of 3–10 nm, and the deconvolution results for XPS spectra showed that the film mainly was constituted by Zr – C , C = C (sp2) and C – C (sp3) bonds.
RECENT DEVELOPMENTS ON PORPHYRIN ASSEMBLIES
Authors: CHARVET RICHARD , HILL JONATHAN P. , XIE YONGSHU , WAKAYAMA YUTAKA , ARIGA KATSUHIKO
Published: January 2009

The porphyrin macrocycle is one of the most frequently investigated functional molecular entities and can be incorporated into advanced functional nanomaterials upon formation of organized nanostructures. Thus, study of the science and technology of porphyrin assemblies has attracted many organic, biological and supramolecular chemists. A wide variety of nanostructures can be obtained by supramolecular self-assembly because the porphyrin moiety is amenable to chemical modifications through thoughtful synthetic design and moderate preparative effort. Some recent developments in porphyrin assembly, obtained through various supramolecular approaches, are briefly summarized. Topics described in this review are classified into four categories: (i) non-specific assemblies; (ii) specific assemblies; (iii) assemblies in organized films; (iv) molecular-level arrangement. We present examples in the order of structural precision of assemblies.
HOTPLATE TECHNIQUE FOR NANOMATERIALS
Authors: ZHU YANWU , SOW CHORNG HAUR
Published: January 2009

As an efficient and cost-effective method to synthesize nanomaterials, the hotplate technique has been reviewed in this article. Systematic studies have been carried out on the characterizations of the materials synthesized. In addition to the direct preparation of nanomaterials on metals, this method has been extended to the substrate-friendly and plasma-assisted hotplate synthesis. Apart from chemically pure nanostructures, a few nanohybrids were synthesized, further demonstrating the flexibility of this technique. The investigations on their applications indicate that they are promising material systems with potential applications in field emission devices, gas sensors, Li -ion batteries and ultrafast optical devices.
NANOMEDICINE: NANOPARTICLES OF BIODEGRADABLE POLYMERS FOR CANCER DIAGNOSIS AND TREATMENT
Authors: FENG S. S.
Published: January 2009

Nanomedicine is to apply and further develop nanotechnology to solve problems in medicine, i.e. to diagnose, treat and prevent diseases at the cellular and molecular level. This article demonstrates through a full spectrum of proof-of-concept research, from nanoparticle preparation and characterization, in vitro drug release and cytotoxicity, to in vivo pharmacokinetics and xenograft model, how nanoparticles of biodegradable polymers could provide an ideal solution for the problems encountered in the current regimen of chemotherapy. A system of vitamin E TPGS coated poly(lactic-co-glycolic acid) (PLGA) nanoparticles is used as an example for paclitaxel formulation as a model drug. In vitro HT-29 cancer cell viability experiment demonstrated that the paclitaxel formulated in the nanoparticles could be 5.64 times more effective than Taxol® after 24 hr of treatment. In vivo pharmacokinetics showed that the drug formulated in the nanoparticles could achieve 3.9 times higher therapeutic effects judged by area-under-the curve (AUC). One shot can realize sustainable chemotherapy of 168 hr compared with 22 hr for Taxol® at a single 10 mg/kg dose. Xenograft tumor model further confirmed the advantages of the nanoparticle formulation versus Taxol®.
NANOSTRUCTURES FROM DESIGNER PEPTIDES
Authors: ONG BOON TEE , AJIKUMAR PARAYIL KUMARAN , VALIYAVEETTIL SURESH
Published: January 2009

The present article reviews the self-assembly of oligopeptides to form nanostructures, both in solution and in solid state. The solution structures of the peptides were examined using circular dichroism and dynamic light scattering. The solid state assembly was examined by adsorbing the peptides onto a mica surface and analyzing it using atomic force microscopy. The role of pH and salt concentration on the peptide self-assembly was also examined. Nanostructures within a size range of 3–10 nm were obtained under different conditions.
COMBINATORICS AND N-KOSZUL ALGEBRAS
Authors: BERGER ROLAND
Published: January 2009

The numerical Hilbert series combinatorics for quadratic Koszul algebras was extended to N-Koszul algebras by Dubois-Violette and Popov [9]. In this paper, we give a striking application of this extension when the relations of the algebra are all the antisymmetric tensors of degree N over given variables. Furthermore, we present a new type of Hilbert series combinatorics, called comodule Hilbert series combinatorics, and due to Hai, Kriegk and Lorenz [15]. When the relations are all the antisymmetric tensors, a natural generalization of the MacMahon Master Theorem (MMT) is obtained from the comodule level, the original MMT corresponding to N = 2 and to polynomial algebras.
TERNARY AND NON-ASSOCIATIVE STRUCTURES
Authors: KERNER RICHARD
Published: January 2009

We discuss ternary algebraic structures appearing in various domains of theoretical and mathematical physics. Some of them are associative, and some are not. Their interesting and curious properties can be exploited in future applications to enlarged and generalized field theoretical models in the years to come.

Many ideas presented here have been developed and clarified in countless discussions with Michel Dubois-Violette.
EXAMPLES OF DERIVATION-BASED DIFFERENTIAL CALCULI RELATED TO NONCOMMUTATIVE GAUGE THEORIES
Authors: MASSON T.
Published: January 2009

Some derivation-based differential calculi which have been used to construct models of noncommutative gauge theories are presented and commented. Some comparisons between them are made.
PARASTATISTICS ALGEBRA, YOUNG TABLEAUX AND THE SUPER PLACTIC MONOID
Authors: LODAY JEAN-LOUIS , POPOV TODOR
Published: January 2009

The parastatistics algebra is a superalgebra with (even) parafermi and (odd) parabose creation and annihilation operators. The states in the parastatistics Fock-like space are shown to be in one-to-one correspondence with the Super Semistandard Young Tableaux (SSYT) subject to further constraints. The deformation of the parastatistics algebra gives rise to a monoidal structure on the SSYT which is a super-counterpart of the plactic monoid.
RENORMALIZED PERTURBATION THEORY: A MISSING CHAPTER
Authors: STORA RAYMOND
Published: January 2009

Renormalized perturbation theory à la BPHZ can be founded on causality as analyzed by Epstein and Glaser in the seventies.

Here, we list and discuss a number of additional constraints of algebraic character some of which have to be considered as parts of the core of the BPHZ framework.
ALGEBRAIC DYNAMICS AND ALGEBRAIC ENTROPY
Authors: VIALLET C.-M.
Published: January 2009

We give the definition of algebraic entropy, which is a global index of complexity for dynamical systems with a rational evolution. We explain its geometrical meaning, and different methods, heuristic or exact to calculate this entropy. This quantity is a very good integrability detector. It also has remarkable properties, which make it an interesting object of study by itself. It is in particular conjectured to be the logarithm of algebraic integer, with a limited range of values, still to be explored.
BOSONS IN RAPID ROTATION
Authors: YNGVASON JAKOB
Published: January 2009

Some recent progress in the mathematical physics of rapidly rotating, dilute Bose gases in anharmonic traps is reviewed.
Computer security and intrusion detection
Authors: Labib Khaled
Published: January 2009

Computer attacks are now commonplace. By connecting your computer to the Internet, you increase the risk of having someone break in, install malicious programs and tools on it, and possibly use it to attack other machines on the Internet by controlling it remotely.Several major banks have been subject to attacks, in which attackers gained access into customers' accounts and viewed detailed information about the activities on these accounts. In some instances the attackers stole credit card information to blackmail e-commerce companies by threatening to sell this information to unauthorized entities. Several online trading companies and e-commerce sites were shut down temporarily due to major packet flood attacks, also known as Denial-of-Service (DoS) attacks, causing these companies to lose revenue, customer satisfaction, and trust [10]. A major software development company discovered that attackers had broken into its network and stolen the source code for future releases of its popular products. Just recently, the source code of the future flagship product belonging to a major software development company was stolen and made publicly available on the Internet.In order to combat this growing trend of computer attacks, both academic and industry groups have been developing systems to monitor networks and systems and raise alarms of suspicious activities. These systems are called Intrusion Detection Systems (IDS).
Stratego
Authors: Kalleberg Karl Trygve
Published: January 2009

Programming languages have a dual role in the construction of software. The language is both our substrate (the stuff we make software from), and our tool (what we use to construct software). Program transformation (PT) deals with the analysis, manipulation and generation of software. Therefore a close relationship exists between program transformation and programming languages, to the point where the PT field has produced many domain-specific languages for manipulating programs. In this article, I will show you some interesting aspects from one of these languages : Stratego.
Modeling protein dependency networks using CoCoA
Authors: Ballard Grey
Published: January 2009

In an interdisciplinary effort to model protein dependency networks, biologists measure signals from certain proteins within cells over a given interval of time. Using this time series data, the goal is to deduce protein dependency relationships. The mathematical challenges is to statistically measure correlations between given proteins over time in order to conjecture probable relationships. Biologists can then consider these relationships with more scrutiny, in order to confirm their conjectures. One algorithm for finding such relationships makes use of interpolation of the data to produce next-state functions for each protein and the Deegan-Packel Index of Power voting method to measure the strength of correlations between pairs of proteins. The algorithm was previously implemented, but limitations associated with the original language required the algorithm to be re-implemented in a more computationally efficient language. Because of the algebraic focus of the Computational Commutative Algebra language, or CoCoA, the algorithm was re-implemented in this language, and results have been produced much more efficiently. In this paper I discuss the algorithm, the CoCoA language, the implementation of the algorithm in CoCoA, and the quality of the results.
Achieving I/O improvements in a mass spectral database
Authors: Puryear Eric , Van Puymbrouck Jennifer , Angulo David Sigfredo , Drew Kevin , Hollenbeck Lee Ann , Battre Dominic , Schilling Alex , Jabon David , von Laszewski Gregor
Published: January 2009

Research in proteomics has created two significant needs: the need for an accurate public database of empirically derived mass spectrum information and the need for managing the I/O and organization of mass spectrometry data in the form of files and structures. Lack of an empirically derived database limits the ability of proteomic researchers to identify and study proteins. Managing the I/O and organization of mass spectrometry data is often time-consuming due to the many fields that need to be set and retrieved. As a result, incompatibilities and inefficiencies are created by each programmer handling this in his or her own way. Until recently, storage space and computing power has been the limiting factor in developing tools to handle the vast amount of mass spectrometry information. Now the resources are available to store, organize, and analyze mass spectrometry information.The Illinois Bio-Grid Mass Spectrometry Database is a database of empirically derived tandem mass spectra of peptides created to provide researchers with an organized and searchable database of curated spectrum information to allow more accurate protein identification. The Mass Spectrometry I/O Project creates a framework that handles mass spectrometry data I/O and data organization, allowing researchers to concentrate on data analysis rather than I/O. In addition, the Mass Spectrometry I/O Project leverages several cross-platform and portability-enhancing technologies, allowing it to be utilized on a variety of hardware and operating systems.
Avoid common pitfalls when programming 2D graphics in java
Authors: Denault Alexandre , Kienzle Jörg
Published: January 2009

This paper presents the core knowledge required to properly develop 2D games in Java. We describe the common pitfalls that can easily degrade graphics performance and show how we achieved impressive frames-per-second display updates when implementing Minueto, a game development framework.
Planning and improvisation in software processes
Authors: Gallardo-Valencia Rosalva E. , Sim Susan Elliott
Published: January 2009

This paper presents the results of an empirical study aimed at examining the extent to which software engineers follow a software process and the extent to which they improvise during the process. Our subjects tended to classify processes into two groups. In the first group are the processes that are formal, strict, and well-documented. In the second group are the processes that are informal and not well-structured. The classification has similar characteristics to the model proposed by Truex, Baskerville, and Travis [12]. Our first group is similar to their methodical classification, and our second group is similar to their amethodical classification. Interestingly, software engineers using a process in the second group stated that they were not using a process. We believe that software engineers who think that they are not using a process, because they have the prevalent concept of process as something methodical that is strict and structured, actually are using an informal (amethodical) process. We also found that software engineers improvise while using both types of processes in order to overcome shortcomings in the planned path which arose due to unexpected situations. This finding leads us to conclude that amethodical processes are processes too.
Storage capacity comparison of neural network models for memory recall
Authors: Patterson Kate
Published: January 2009

The physiology of how the human brain recalls memories is not well understood. Neural networks have been used in an attempt to model this process.

Two types of networks have been used in several models of temporal sequence memory for simple sequences of randomly generated and also of structured patterns: auto- and hetero-associative networks. Previous work has shown that a model with coupled auto- and hetero-associative continuous attractor networks can robustly recall learned simple sequences. In this paper, we compare Hebbian learning and pseudo-inverse learning in a model for recalling temporal sequences in terms of their storage capacities. The pseudo-inverse learning method is shown to have a much higher storage capacity, making the new network model 700% more efficient by reducing calculations.
How to succeed in graduate school
Authors: des Jardins Marie
Published: January 2009

This paper attempts to raise some issues that are important for graduate students to be successful and to get as much out of the process as possible, and for advisors who wish to help their students be successful. The intent is not to provide prescriptive advice-no formulas for finishing a thesis or twelve-step programs for becoming a better advisor are given-but to raise awareness on both sides of the advisor-student relationship as to what the expectations are and should be for this relationship, what a graduate student should expect to accomplish, common problems, and where to go if the advisor is not forthcoming.
Visualizing flow data using assorted glyphs
Authors: Sawant Amit Prakash , Healey Christopher G.
Published: January 2009

This project visualizes a scientific dataset containing two-dimensional flow data from a simulated supernova collapse provided by astrophysics researchers. We started our project by designing visualizations using multiple hand drawings representing the flow data without taking into consideration the implementation constraints of our designs. We implemented a few of our hand drawn designs. We used an assortment of simple geometric graphical objects, called glyphs, such as, dots, lines, arrows, and triangles to represent the flow at each sample point. We also incorporated transparency in our visualizations. We identified two important goals for our project: (1) design different types of graphical glyphs to support flexibility in their placement and in their ability to represent multidimensional data elements, and (2) build an effective visualization technique that uses glyphs to represent the two-dimensional flow field.
The use of compiler optimizations for embedded systems software
Authors: Bungo Joe
Published: January 2009

Optimizing embedded applications using a compiler can generally be broken down into two major categories: hand-optimizing code to take advantage of a particular processor's compiler and applying built-in optimization options to proven and well-polished code. The former is well documented for different processors, but little has been done to find generalized methods for optimal sets of compiler options based on common goal criteria such as application code size, execution speed, power consumption, and build time. This article discusses the fundamental differences between these two general categories of optimizations using the compiler. Examples of common, built-in compiler options are presented using a simulated ARM processor and C compiler, along with a simple methodology that can be applied to any embedded compiler for finding an optimal set of compiler options.
How to succeed in graduate school
Authors: desJardins Marie
Published: January 2009

This paper attempts to raise some issues that are important for graduate students to be successful and to get as much out of the process as possible, and for advisors who wish to help their students be successful. The intent is not to provide prescriptive advice -- no formulas for finishing a thesis or twelve-step programs for becoming a better advisor are given -- but to raise awareness on both sides of the advisor-student relationship as to what the expectations are and should be for this relationship, what a graduate student should expect to accomplish, common problems, and where to go if the advisor is not forthcoming.
A human's eye view
Authors: Scher Zagier Ellen J.
Published: January 2009

Frameless Rendering (FR) is a rendering paradigm which performs stochastic temporal filtering by updating pixels in a random order, based on most recent available input data, and displaying them to the screen immediately [1]. This is a departure from frame-based approaches commonly experienced in interactive graphics. A typical interactive graphics session uses a single input state to compute an entire frame. This constrains the state to be known at the time the first pixel's value is computed. Frameless Rendering samples inputs many times during the interval which begins at the start of the first pixel's computation and ends with the last pixel's computation. Thus, Frameless Rendering performs temporal supersampling - it uses more samples over time. This results in an approximation to motion blur, both theoretically and perceptually.This paper explores this motion blur and its relationship to: camera open shutter time, current computer graphics motion-blur implementations, temporally anti-aliased images, and the Human Visual System's (HVS) motion smear quality (see 'quality' footnote) [2].Finally, we integrate existing research results to conjecture how Frameless Rendering can use knowledge of the Human Visual System's blurred retinal image to direct spatiotemporal sampling. In other words, we suggest importance sampling (see 'sampling' footnote) by prioritizing pixels for computation based on their importance to the visual system in discerning what is occurring in an interactive image sequence.
Levels of detail & polygonal simplification
Authors: Krus Mike , Bourdot Patrick , Guisnel Françoise , Thibault Gullaume
Published: January 2009

This paper covers the techniques of Polygonal Simplification in order to produce Levels of Detail (LODs). The problem of creating LODs is a complex one: how can simpler versions of a model be created? How can the approximation error be measured? How can the visual degradation be estimated? Can all this be done automatically? After exposing the basic aims and principles of polygonal simplification, we compare recent algorithms and state their various qualities and weaknesses.
Faster 3D game graphics by not drawing what is not seen
Authors: Hoff Kenneth E.
Published: January 2009

The increasing demands of 3D game realism - in terms of both scene complexity and speed of animation - are placing excessive strain on the current low-level, computationally expensive graphics drawing operations. Despite these routines being highly optimized, specialized, and often being implemented in assembly language or even in hardware, the ever-increasing number of drawing requests for a single frame of animation causes even these systems to become overloaded, degrading the overall performance. To offset these demands and dramatically reduce the load on the graphics subsystem, we present a system that quickly and efficiently finds a large portion of the game world that is not visible to the viewer for each frame of animation, and simply prevents it from being sent to the graphics system. We build this searching mechanism for unseen parts from common and easily implemented graphics algorithms.
Techniques & tools for using color in computer interface design
Authors: Wright Peggy , Mosser-Wooley Diane , Wooley Bruce
Published: January 2009

Contemporary computers predominantly employ graphical user interfaces (GUIS) and colour is a major componenet of the GUI. Every man-machine interface is composed of two major parts:the man and the machine [4]. Color interfaces are no different in that they are also based on two parts, the Human visual system (HVS) and a color display system. A theoretical examination of these two components establishes a foundation for developing practical guidelines for color interfaces. This paper will briefly examine theoretical aspects of both components and established techniques and tools for the effective use of color for software interface design.
An investigation of current virtual reality interfaces
Authors: Perry Lynellen D. S. , Smith Christopher M. , Yang Steven
Published: January 2009

Virtual Reality hype is becoming a large part of everyday life. This paper explores the components of actual virtual reality systems, critiquing each in terms of human factors. The hardware and software of visual, aural, and haptic input and feedback are considered. Technical and human factor difficulties are discussed and some potential solutions are offered.
Protecting Java code via code obfuscation
Authors: Low Douglas
Published: January 2009

The Java language is compiled into a platform independent bytecode format. Much of the information contained in the original source code remains in the bytecode, thus decompilation is easy. We will examine how code obfuscation can help protect Java bytecodes.
Objective viewpoint: Java AWT layout management 101
Authors: Crawford George
Published: January 2009

This article provides a brief summary of basic layout management in the Java Abstract Window Toolkit (AWT) and is intended to serve as a foundation for more sophisticated AWT programming.
Signing electronic contracts
Authors: Molnar David
Published: January 2009

Electronic commerce faces the problem of signing electronic contracts. Three approaches for handling electronic contracts include 1) no trusted third party protocols, 2) strongly-trusted third party protocols and 3) weakly-trusted third party protocols. A secondary problem facing electronic commerce is self-enforcing contract design.
The processor-memory bottleneck
Authors: Mahapatra Nihar R. , Venkatrao Balakrishna
Published: January 2009

The rate of improvement in microprocessor speed exceeds the rate of improvement in DRAM (Dynamic Random Access Memory) speed. So although the disparity between processor and memory speed is already an issue, downstream someplace it will be a much bigger one. Hence computer designers are faced with an increasing Processor - Memory Performance Gap [1], which now is the primary obstacle to improved computer system performance. This article examines this problem as well as its various solutions.