bluuebunny/crossref_metadata_2025 huggingface dataset:
Creep, shrinkage, frost, and sulphate resistance of high strength concrete
Authors: Ghosh Sujit , Nasser K. W.
Published: January 2010

A comprehensive study was undertaken to determine the shrinkage, creep, and durability of high strength concrete (50–70 MPa) containing silica fume and lignite fly ash. The concrete mixtures contained normal CSA type 10 (ASTM type 1) portland cement, 10% condensed silica fume, and different amounts of fly ash that varied between 0 and 80% of the weight of binder in the mixture. The aggregates-to-binder ratio by weight was maintained at 5 and the weight of the superplasticizer was varied between 1.5% and 2.2% of the binder while the water-to-binder ratio was maintained at 0.27. The test program consisted of compressive strength tests at various ages on concrete cylinders; drying shrinkage tests at room temperature; creep tests of sealed and unsealed concrete at room temperature (21 °C (70°F)) and at high temperatures (up to 232 °C (450°F)) under three different stress regimes; frost resistance tests on concrete prisms up to 300 freezing and thawing cycles; and sulphate resistance tests on concrete prisms immersed in 5% Na2SO4 solution for up to 10 months. The results indicated that up to 60% fly ash replacement with 10% silica fume showed either superior or similar 28- and 56-day compressive strengths when compared with the 100% cement control mixture. Fly ash + silica fume concrete indicated lower shrinkage and long-term creep. Creep increased with increase in temperature due to physico-chemical processes, which were confirmed by microstructure analysis using the scanning electron microscope. The creep and shrinkage data of high fly ash + silica fume concrete fitted well to the current ACI creep and shrinkage model. Replacement of cement by up to 35% fly ash and 10% silica fume indicated enhanced frost resistance, without any air-entrainment. The addition of 8% air-entrainment to the 20% fly ash + 10% silica fume mixture increased the durability factor by about 10%. For the 50% fly ash + 10% silica fume mixture, the frost durability factor was found comparable to that of the 100% cement control mixture, and air entrainment did not improve its value appreciably. Sulphate resistance of concrete made with 100% CSA type 10 cement was found satisfactory; however, with increasing fly ash contents (up to 50%), the expansion due to sulphate action was suppressed. A study of matrix morphology and microstructure bonding, using the scanning electron microscope, helped to explain the observed results in a comprehensive manner. Key words: creep, shrinkage, compressive strength, frost resistance, durability factor, sulphate resistance, fly ash, silica fume, high-strength concrete, SEM micrograph, matrix morphology.
Effects of roof size, heat transfer, and climate on snow loads: studies for the 1995 NBC
Authors: Irwin P. A. , Gamble S. L. , Taylor D. A.
Published: January 2010

As roof sizes increase, the ability of the wind to reduce the uniform snow loads is diminished, thus resulting in higher uniform loads. Results of recent research into this size effect and the influence of heat loss through roofs in four Canadian cities (St. John's, Montreal, Saskatoon, and Edmonton) using the finite area element method are described and snow load formulae for uniform loads on large roofs are proposed. Also, the drift loading on lower roofs adjacent to large area upper roofs has been studied using similar techniques, and revised formulae for the peak loading in the drift at the step are put forward taking into account the size of the upper roof and the presence of parapets. The snow load provisions developed in this paper have been proposed for the 1995 edition of the National Building Code. Key words: snow loads, drift loads, uniform loads, large flat roofs, size effect, heat loss, finite area element method, computational fluid dynamics.
NEUROSLAB – neural network system for horizontal formwork selection
Authors: Hanna Awad S. , Senouci Ahmed B.
Published: January 2010

This paper presents an overview of the neural network technique as a tool for concrete formwork selection. The paper discusses the development and the implementation of a neural network system, NEUROSLAB, for the selection of horizontal formwork systems. A rule-based expert system for the selection of horizontal systems, SLABFORM, was used as the basis for the development of NEUROSLAB. A training set of 202 cases was used to train the network. The network adequately learned the training examples with an average training error of 0.025. A set of 50 cases was used to test the generalization ability of the system. The network was able to accurately select the appropriate horizontal formwork system with an average testing error of 0.057. The ability of the network to deal with noisy data was also tested. Up to 50% noise was added to the data and introduced to the network. The results showed that the network presented could accurately identify the appropriate horizontal formwork system at high level of noise. Finally, the solution chosen by an expert was compared to that produced by the network. The network was able to mimic the expert's formwork selection. Key words: formwork, horizontal formwork systems, neural network, formwork selection, back propagation, expert system.
Étude numérique et expérimentale des ondes secondaires de Favre consécutives à la rupture d'un barrage
Authors: Marche Claude , Beauchemin Patrick , Kayloubi Abdelaziz El
Published: January 2010

Free-surface transient flows generate wave propagation. Digital models of this phenomenon are based on Saint Venant's equations and assumptions, which do not consider the impact of stream line curves. In some cases, this approach leads to incorrect forecasts of the water line profile and flow speeds generated, and hence underestimation of the size of the flood zone, for example, or the destructive capacity of the dam-break flow. This paper suggests a more complete model, based on Boussinesq's approach, that yields much more accurate consequence forecasts. Laboratory tests confirmed heights, speeds, and pressures, which were also consistent with conclusions drawn from the Favre diagram. Key words: transient flows, dam failure, Favre waves, flooding, damage. [Journal translation]
Modelling of pollutant mixing in the St. Lawrence River
Authors: Zhou Siping , McCorquodale J. A. , Biberhofer J.
Published: January 2010

Many of Canada's large rivers, such as the connecting channels of the Great Lakes, receive contaminant loads from industrial, municipal, and tributary sources. These contaminants experience two general types of mixing, outlet-dominated mixing processes (near field) and river-dominated mixing processes (far field). This note is concerned with the numerical modelling of the far field processes by a fully elliptic form of the two-dimensional depth-averaged river model proposed by Rodi et al. Many of the popular hydrodynamics codes experience numerical diffusion which far exceeds the real turbulent diffusion; a new method known as the semi-implicit skewed upwind method is introduced to minimize the numerical dispersion for rivers with highly nonlinear alignment. The new model is verified by comparison with the field data obtained from a dye study in the St. Lawrence River. Key words: pollutant transport, river mixing, far field model, numerical diffusion.
Falling weight deflectometer data interpretation using dynamic impedance
Authors: Stolle Dieter , Peiravian Farideddin
Published: January 2010

This paper deals with the characterization of pavements and their supporting subgrade by comparing the measured dynamic impedance of a site, based on falling weight deflectometer data, with that of a two-layer, elastodynamic model. The pavement is modelled as a Kirchhoff plate and the subgrade as an incompressible, semi-infinite, elastic half space. The impedance of the two-layer problem is developed in graphical form as a function of a dimensionless angular frequency that depends on the pavement and subgrade properties. The characterization methodology outlined is applied to both simulated and actual field data. The effects of bedrock location and increasing subgrade stiffness with depth on dynamic impedance are addressed, and some limitations associated with the back calculation of system parameters are discussed. Key words: pavements, layer moduli, impedance, dynamic, back calculation.
Seismic behavior of single-storey steel structures with a flexible roof diaphragm
Authors: Tremblay Robert , Stiemer Siegfried F.
Published: January 2010

The nonlinear response of 36 rectangular single-storey steel buildings subjected to historical earthquake accelerograms is examined. The buildings were designed according to current Canadian practice. The lateral load resisting system of the buildings includes a flexible metal roof deck diaphragm and vertical bracing located along the exterior walls. The results indicate that the fundamental period of the structures, the maximum drift, the forces and deformations in the roof diaphragm, and the ductility demand on the vertical bracings cannot be adequately predicted with existent design provisions. Tentative design guidelines are proposed on the basis of the results obtained in the study. Key words: analysis, design, seismic, dynamic, structures, steel, roof diaphragm.
Design of face-shell bedded hollow masonry subject to concentrated loads
Authors: Sayed-Ahmed Ezzeldin Y. , Shrive Nigel G.
Published: January 2010

Many parameters affect the behaviour and failure of face-shell bedded hollow masonry subject to concentrated load. Detailed study of these parameters is needed to develop realistic design rules for this situation. The effects of loaded length and wall dimensions on capacity of the face-shell bedded hollow masonry subject to concentrated load are studied; the effect of mortar joint strength is also evaluated. The current design detail of filling some of the blocks under the concentrated load with grout is reviewed. The study was performed with a nonlinear elastoplastic finite element model that takes into account geometric and material nonlinearities as well as damage due to progressive cracking. The methodology, when combined with substructuring, allows analysis of substantially larger walls than would more typical three-dimensional analyses. The results indicate that the length of the loading plate is the significant parameter for load capacity. A possible design equation for plain hollow masonry subject to concentrated loads, concentric across the width of the wall, is provided. Adjustments could be made given the precise loading detail specified. Improvement details are explained. Key words: masonry, hollow concrete masonry, finite element modelling, cracking, failure, strength-enhancement factor, concentrated loads.
Borehole penetration and expansion devices for ice testing
Authors: Ladanyi Branko
Published: January 2010

The paper presents two methods for in situ testing of strength and creep properties of ice, together with their theoretical interpretation and typical results. The two methods which are relatively new in this area of application, are the stress-controlled cone penetration test (CPT), and the sharp cone test (SCT). The CPT has been shown in the last few years to be an excellent tool for both ice quality profiling and ice creep and strength properties determination. The test can be used for penetrating vertically through an ice sheet, or laterally into an ice wall in a trench. The SCT is a special kind of borehole-expansion test. The method consists in pushing a smooth, low-angle, conical indentor into a predrilled conical portion of a borehole, which ends with a smaller diameter pilot hole. The creep properties of ice are then deduced from the relationship between the applied load, time, and cone penetration, which is directly related to the hole expansion. Key words: ice, creep, strength, in situ testing, cone penetration, borehole expansion, sharp cone.
Reliability analysis for critical reaction forces of lumber members with an end notch
Authors: Smith Ian , Chui Ying Hei , Hu Lin Juan
Published: January 2010

The basis of new design provisions for avoidance of brittle failures in sawn lumber members with an end notch is explained. Linear elastic fracture mechanics and structural reliability concepts are combined with material property data to determine appropriate forms of equations for limiting the reaction force, when a notch is made on either the tension or compression face of a member. Following from this, the factored reaction force resistance of a member designed to the 1994 edition of the CSA Standard 086.1 "Engineering design in wood (limit states design)" depends upon the depth of the member and the geometry and size of an end notch if the notch is located on the tension face. A new property, the specified reaction force strength, which is a measure of the capability of the material to resist fracture, is taken to be independent of the timber species and stress grade of the lumber. Design variables such as duration of load and moisture service condition influence assignments of factored reaction force resistances for members end notched on the tension face. When a notch is located on the compression face of a member the resistance is simply the factored shear resistance of the residual cross section. As in previous editions of CSA Standard 086.1, notches are not permitted to have a depth greater than 0.25 times the depth of the section. Key words: lumber, fracture, structural reliability, notched beam, design criterion.
Torsional – flexural buckling strength of steel angles
Authors: Adluri Seshu M. R. , Madugula Murty K. S.
Published: January 2010

Although structural steel angles have a wide variety of applications, they have not received attention comparable to that given to heavy shapes such as wide-flange sections. Because steel angles are singly symmetric or asymmetric, torsional-flexural buckling is an important mode of failure. The Canadian steel design practice for hot-rolled steel members (as given by CAN/CSA-S16.1-94) does not give a detailed procedure applicable to all sizes of steel angles. Some of the world codes applicable for steel angles specify torsional–flexural buckling check and plate buckling check to be considered simultaneously wherever applicable. The paper presents the results of an experimental investigation consisting of 34 hot-rolled steel angles under concentric compression (slenderness ratios between 50 and 150) failing in torsional?flexural buckling. The width to thickness ratios of test specimens ranged from 13 to 20. The results give a continuous spread of compressive strengths for practical ranges of slenderness parameters. The results show that torsional–flexural buckling and plate buckling need not be considered simultaneously even for unequal angles if they are designed according to CAN/CSA-S16.1-94. Key words: angle, buckling, codes and standards, compression, design strength, flexural buckling, local buckling, specifications, steel, torsional–flexural buckling.
The precision of average annual daily traffic volume estimates from seasonal traffic counts: Alberta example
Authors: Sharma Satish C. , Wu Yongquiang , Kilburn Peter
Published: January 2010

Investigated in this note is the precision of average annual daily traffic (AADT) volumes estimated from seasonal traffic counts (STC). A large number of road sites located on Alberta's rural highway system were studied. Three frequencies for seasonal traffic counts were considered. They were rotations where the automated traffic recording devices would be active for 2, 3, or 4 selected noncontinuous months of the year. The AADT volume error margins or precision at a 95% confidence level as found in this study are (i) ± 8.00% for 2 noncontinuous month counts during a year, (ii) ± 5.60% for 3 noncontinuous month counts during a year (1993 Alberta program), and (iii) ± 3.61% for 4 noncontinuous month counts during a year. The research can help traffic engineers in carrying out a cost-effectiveness analysis of STC programs, and the precision values such as presented in this research can play an important role in considering a trade-off between the cost and the accuracy of various counts. Key words: AADT, sampling errors, seasonal traffic counts, transportation, traffic volume studies.
Laboratory tests of ice interaction with steel booms
Authors: Timco G. W. , Cornett A. M.
Published: January 2010

A test program was carried out to study the interaction of ice with sections of ice-control booms. Two different boom shapes and four different boom sizes were tested. The results indicate that there can be several different failure modes for the ice during the interaction. Particularly high loads were obtained when the ice failed in a buckling failure mode. To minimize the ice-induced loads, the boom must be designed to prevent this failure mode and induce flexural failures in the ice. This note presents quantitative information on the loads measured for different boom shapes and sizes, and for different ice thickness. The results can be used to help optimize the design of a suitable boom for ice control. Key words: ice, ice control, ice booms, St. Lawrence River, loads, forces, design.
Sight distance evaluation on complex highway vertical alignments
Authors: Easa Said M. , Hassan Yasser , Halim A. O. Abd El
Published: January 2010

Sight distance (stopping, passing, and decision) is a key element in highway geometric design. Existing models for evaluating sight distance on vertical alignments are applicable only to simple, isolated elements such as a crest vertical curve, a sag vertical curve, and a reverse vertical curve (a sag curve following a crest curve, or vice versa). This paper presents an analytical methodology for evaluating sight distance on complex vertical alignments that involve any combination of vertical alignment elements. The methodology can be used for evaluating passing sight distance on two-lane highways, and stopping sight distance and decision sight distance on all highways. Sight distance controlled by the headlight beam can also be evaluated. The locations of sight-hidden dips, which may develop when a sag vertical curve follows a crest vertical curve with or without a common tangent, can be determined. Also, sight distances obstructed by overpasses are evaluated. A profile of the available sight distance can be established and used to evaluate sight distance deficiency and the effect of alignment improvements. A software was developed and can be used for determining the available sight distance accurately. The software may replace the current field and graphical practice for establishing the no-passing zones and evaluating stopping and decision sight distances on complex vertical alignments. Key words: sight distance, vertical alignment, highway, passing zones.
Seismic design of steel buildings: lessons from the 1995 Hyogo-ken Nanbu earthquake
Authors: Tremblay Robert , Filiatrault Andre , Bruneau Michel , Nakashima Masayoshi , Prion Helmut G. L. , DeVall Ron
Published: January 2010

Past and current seismic design provisions for steel structures in Japan are presented and compared with Canadian requirements. The performance of steel framed structures during the January 17, 1995, Hyogo-ken Nanbu earthquake is described. Numerous failures and examples of inadequate behaviour could be observed in buildings of various ages, sizes, and heights, and braced with different structural systems. In moment resisting frames, the damage included failures of beams, columns, beam-to-column connections, and column bases. Fracture of bracing members or their connections was found in concentrically braced frames. The adequacy of the current Canadian seismic design provisions is examined in view of the observations made. Key words: earthquake, seismic design, steel structures.
Beams prestressed with unbonded tendons at ultimate
Authors: Pisani Marco Andrea , Nicoli Emilio
Published: January 2010

This paper presents a numerical investigation on beams and slabs prestressed with either unbonded internal or external tendons. Twenty-three experimental tests (beams and slabs prestressed with unbonded internal tendons) were numerically simulated to verify the reliability of the numerical algorithm adopted. The good agreement established enables us to study the behaviour of these beams in depth and to compare it with the behaviour of similar beams prestressed with external tendons. The numerical analyses were then repeated after including the safety factors related to the materials. The outputs were then compared with the results adopted by making use of the simplified method suggested by Eurocode E.C.2 Part 1-5, to check the size of the error involved in the adoption of the latter. Key words: numerical analysis, unbonded internal tendons, external tendons, European Prestandard, prestressed concrete, beams, post-tensioned.
Kinetics of an anaerobic fluidized bed reactor using biolite carrier
Authors: Prakash R. , Kennedy K. J.
Published: January 2010

Start-up and steady state operation of anaerobic fluidized bed reactors (AFBRs) with biolite as the inert carrier material was studied. Start-up and concomitant biofilm development of AFBRs was performed using two common start-up techniques, the maximum efficiency profile (MEP) technique and the maximum load profile (MLP) technique. The MEP start-up technique increases the volumetric organic loading rates to the reactor gradually and is tied to the removal efficiency of the process. The MLP start-up technique maintains a moderately high but constant volumetric organic loading rate irrespective of reactor performance. Using sucrose-based wastewater as feed, both start-up techniques led to equally fast biofilm development and start-up times of approximately 5 weeks. However, the MEP technique resulted in more stable controlled reactor operation during the start-up period. The quick start-up confirms the high compatibility of biolite for bio-adhesion and the development of a healthy active biofilm.High concentrations of biofilm biomass achieved in AFBRs (69 g volatile biofilm solids (VBS)/L of expanded bed volume at an organic loading rate of 25 g COD/(Lùd)) allowed the successful treatment of wastewaters at high organic loading rates and organic removal efficiencies. During steady state experiments, organic removal efficiencies over 80% were obtained for organic loading rates as high as 20 g COD/(L∙d). It was found that the dependence of removal efficiency on hydraulic retention time is influenced by substrate concentration. Total biofilm yield was determined to be 0.08 g VBS/g COD removed, demonstrating the low net synthesis of solids in the AFBR. AFBRs had an average solids retention time of 150 days, corresponding to a washout factor of 0.01. Extrinsic kinetics of the AFBRs was determined to be zero order with a maximum specific utilization rate of 0.48 g COD/(g VBS∙d).AFBRs used to treat municipal landfill leachate with a BOD5:COD ratio of 0.86 achieved steady state COD removal efficiencies that ranged from 70% to 87%, depending on the reactor organic loading rate and the concentration of the leachate being treated. During leachate treatment, biofilm biomass gradually became "mineralized" as a result of precipitation of metal sulfides and carbonates. This eventually resulted in a decrease in biofilm microbial activity and the need for higher pumping rates to maintain the same degree of bed expansion. Key words: anaerobic, biological fluidized bed reactor, biolite, landfill leachate, sucrose, modeling, start-up, steady state kinetics.
Characterization of Nova Scotia surface waters and treatment options for removal of colour and trihalomethane precursors
Authors: Waller D. H. , MacPhee M. J. , Prendiville P. W. , McCurdy R. F. , Gates A. W. , D'Eon W. J.
Published: January 2010

This paper provides an overview of the results of a study undertaken to provide a basis for predesign evaluation of the effectiveness of options for treatment of municipal surface waters in the province of Nova Scotia. Seasonal samples of raw water were obtained from the fall of 1992 through the fall of 1993 from five sites. Results were compared with a Nova Scotia Department of Health data base of randomly collected samples. For project samples, strong relationships were evident between raw water total organic carbon (TOC) and both colour and trihalomethane formation potential. Laboratory batch tests, supported by plant results, indicated that percentage removals of TOC increase with raw water TOC, and that settling-filtration was more effective than direct filtration for waters with higher raw TOC concentrations. Results of solids settling tests were consistent with TOC results. A treatment optimized for TOC removal also ensured removal of colour. TOC removals by dissolved air flotation followed by filtration exceeded removals by direct filtration or settling-filtration, based on laboratory bench tests, particularly at sites with higher values of raw TOC. Colour removal by dissolved air flotation was consistently higher at all sites. Key words: enhanced coagulation, trihalomethane precursors, total organic carbon, surface water treatment, dissolved air flotation.
Rehabilitation measures for Champlain Bridge, Montreal, Canada
Authors: Carlin G. P. , Mirza M. S. , Gaudreault M.
Published: January 2010

Major rehabilitation of the Champlain Bridge, Montreal, Quebec, has been undertaken with the goal of restoring its overall integrity. The bridge is a major transportation link carrying over 42 million vehicle transits annually. Repairs to all elements of the structure have recently been under way, such as deck replacement, pier repairs including submerged regions, restoration to prestressed girders, implementation of cathodic protection to control corrosion, new drainage provisions, and crash barriers. Rehabilitation of the main steel truss spans over the St. Lawrence Seaway is presented elsewhere. Testing of two cathodic protection systems on prestressed concrete beams has been undertaken with the goal of full-scale installation on all 50 affected spans. A possible pilot project is being examined, which incorporates the use of zinc anode spray applied to the concrete surface to act as passive, or induced current type, or as a combination of active and passive systems on the different sections of the bridge. Key words: bridge rehabilitation, cathodic protection systems, condition survey, corrosion protection strategy, external prestressing, honeycombing and spalling, impervious membrane, injection of cracks, prestressed concrete beams, underwater pier repairs.
Replacement of reinforced concrete deck of Champlain Bridge, Montreal, by orthotropic steel deck
Authors: Carlin G. P. , Mirza M. S.
Published: January 2010

The Champlain Bridge, Montreal, Quebec, has recently undergone replacement of its deteriorated reinforced concrete deck situated over the St. Lawrence Seaway with a new orthotropic steel deck. The new deck consists of 210 prefabricated steel panels which have been installed at the rate of one panel per night. The panels arrived on site with a base course of pavement to allow traffic flow over the new panels without disrupting the rush hour and daytime traffic. As a result of the new deck being 25% lighter in weight, the reserve strength capacity of the steel superstructure to accommodate live loads has increased sufficiently to bring the bridge within the governing live load requirements of the CAN/CSA Standard S6-1988 "Design of highway bridges." The governing design live loads on bridges have increased by about 50% since the original construction of the bridge over 30 years ago and reflect the larger vehicle weights permitted over Canadian roadways. Key words: alternative deck systems, cantilevered steel superstructure, closed rib stiffeners, counterweights, diaphragms, field erection, orthotropic plate deck, prefabrication, reinforced concrete, welding.
Supersymmetric form of the string action in the presence of the gauge field
Authors: Kamani Davoud
Published: January 2010

In this manuscript, we study the superstring theory with an Abelian worldsheet gauge field. The components of the gauge field appear as space and time coordinates. We call them “fictitious coordinates”. The worldsheet supersymmetry and the Poincaré symmetry of this model will be analyzed. The T-duality and quantization of the two fictitious coordinates are also obtained.
Diffusion superélastique des électrons sur les états métastables nsnp 3P0,2 des atomes de magnésium et de strontium
Authors: Shafranyosh I. I. , Marushka V. I.
Published: January 2010

Experimental results are presented on electron superplastic diffusion processes on nsnp 3P0,2 metastable states in magnesium and strontium atoms. An electron spectrometer with right angle crossed beams for electrons and atoms was used, the electron energy ranging between 0.15 and 2.0 eV. For the first time, superelastic electron diffusion cross-sections were measured on metastable magnesium and strontium atoms, with maximum values of (3.0 ± 1.8) × 10−16 cm2 and (20 ± 12) × 10−16 cm2, respectively. We have observed resonances, associated with the formation of negative ions, on the energy fonctions of the diffusion cross-sections for superelastic electron diffusion at 0.4 eV and 0.45 eV on Mg and Sr, respectively.
A nonlinear stability analysis in a double-diffusive magnetized ferrofluid with magnetic-field-dependent viscosity saturating a porous medium
Authors: Sunil  , Mahajan Amit
Published: January 2010

A rigorous nonlinear stability result is derived by introducing a suitable generalized energy functional for a magnetized ferrofluid layer heated and soluted from below with magnetic-field-dependent (MFD) viscosity saturating a porous medium, in the stress-free boundary case. The mathematical emphasis is on how to control the nonlinear terms caused by the magnetic-body and inertia forces. For ferrofluids, we find that there is possibility of existence of subcritical instabilities, however, it is noted that, in case of a non-ferrofluid, the global nonlinear stability Rayleigh number is exactly the same as that for linear instability. For lower values of magnetic parameters, this coincidence is immediately lost. The effect of the magnetic parameter, M3; solute gradient, Sf; Darcy number, Da; and MFD viscosity parameter, δ; on the subcritical instability region has also been analyzed.
A Bose description of the 1-D para-Bose and para-Fermi oscillators
Authors: Cova Ramón J.
Published: January 2010

In the Fock space of two Bose operators all the irreducible representations of both the 1-D para-Bose and para-Fermi oscillators are constructed. Bose states of the form |p + k–1, kn > (|p – k, kn), n = 1,2, are shown to stand for states of k-parabosons (k-parafermions) of order p. For n = 1 or n = 2 the various subspaces may be visualized in the plane as either straight-lines or parabolae, respectively.
Entropy and its squeezing in an intensely driven atomic system
Authors: El-Deberky M. A.A.
Published: January 2010

Atomic entropy and its squeezing are investigated for an intensely driven two-level atom in the presence of a broadband-squeezed vacuum field. Specifically, the effect of the field-dependent atomic decay parameter combined with the initial atomic coherent state is examined in detail.
THE EFFECT OF DAMAGED VEHICLES EVACUATION ON TRAFFIC FLOW BEHAVIOR
Authors: MHIRECH ABDELAZIZ , EZ-ZAHRAOUY HAMID , ISMAILI ASSIA ALAOUI
Published: January 2010

The effect of the damaged car evacuation on the traffic flow behavior is investigated, in the one-dimensional deterministic Nagel–Schreckenberg model, using parallel dynamics. A realistic model applied to the cars involved in collisions is considered. Indeed, in this model we suppose that the damaged cars must be removed from the ring with a probability P exit . This investigation enables us to understand how the combination of the two probabilities, namely P col and P exit , acts on density and current. It is found that the current and density at the steady state, depend strongly on the initial density of cars in the ring. However, for the intermediate initial density ρi, the current J decreases when increasing either P exit and/or P col . While, for high initial density, J increases passes through a maximum and decreases for large values of P exit . Furthermore, the current can decrease or increase with the collision probability depending on the initial density.
FAULT TOLERANT QUANTUM KEY DISTRIBUTION BASED ON QUANTUM DENSE CODING WITH COLLECTIVE NOISE
Authors: LI XI-HAN , ZHAO BAO-KUI , SHENG YU-BO , DENG FU-GUO , ZHOU HONG-YU
Published: January 2010

We present two robust quantum key distribution protocols against two kinds of collective noise, following some ideas in quantum dense coding. Three-qubit entangled states are used as quantum information carriers, two of which form the logical qubit, which is invariant with a special type of collective noise. The information is encoded on logical qubits with four unitary operations, which can be read out faithfully with Bell-state analysis on two physical qubits and a single-photon measurement on the other physical qubit, not three-photon joint measurements. Two bits of information are exchanged faithfully and securely by transmitting two physical qubits through a noisy channel. When the losses in the noisy channel is low, these protocols can be used to transmit a secret message directly in principle.
A BIPED WITH A MOVING TORSO
Authors: KAPPAGANTHU KARTHIK , NATARAJ C.
Published: January 2010

The moving torso plays an important role in the dynamics of bipeds like human beings, the exploitation of which is the essential focus of this paper. A design is presented where the torso is actuated to make the biped walk with the required step-length while allowing the legs to move passively. A periodic response excitation is achieved and the motion of the torso is optimized with respect to the external energy input. A working model of the biped is designed and built in which only the torso is actuated and the legs are passive. This laboratory model is used to test and validate the analytical solutions.
DESIGN, CONTROL AND EVALUATION OF A WHOLE-SENSITIVE ROBOT ARM FOR PHYSICAL HUMAN-ROBOT INTERACTION
Authors: TSETSERUKOU DZMITRY , KAWAKAMI NAOKI , TACHI SUSUMU
Published: January 2010

The paper focuses on design and control of a new anthropomorphic robot arm enabling the torque measurement in each joint to ensure safety while performing tasks of physical interaction with human and environment. When the contact of the robot arm with an object occurs, local admittance algorithm provides active compliance of corresponding robot arm joint. Thus, the whole structure of the manipulator can safely interact with an unstructured environment. The detailed design procedure of the 4-DOF robot arm and optical torque sensors is described in the paper. The experimental results of joint admittance control revealed the feasibility of the proposed approach to provide safe interaction of entire structure of robot arm with a person. The control system with load angle position feedback and lead compensator is proposed to improve dynamic behavior of flexible joint arm. The experimental results show high performance of the developed controller in terms of successful damping of vibrations.
A BOUNDARY VERSION OF CARTAN–HADAMARD AND APPLICATIONS TO RIGIDITY
Authors: LAFONT JEAN-FRANÇOIS
Published: January 2010

The classical Cartan–Hadamard theorem asserts that a closed Riemannian manifold Mn with non-positive sectional curvature has universal cover [Formula: see text] diffeomorphic to ℝn, and a by-product of the proof is that [Formula: see text] is homeomorphic to Sn-1. We prove analogues of these two results in the case where Mn has a non-empty totally geodesic boundary. More precisely, if [Formula: see text], [Formula: see text] are two negatively curved Riemannian manifolds with non-empty totally geodesic boundary, of dimension n ≠ 5, we show that [Formula: see text] is homeomorphic to [Formula: see text]. We show that if [Formula: see text] and [Formula: see text] are a pair of non-positively curved Riemannian manifolds with totally geodesic boundary (possibly empty), then the universal covers [Formula: see text] and [Formula: see text] are diffeomorphic if and only if the universal covers have the same number of boundary components. We also show that the number of boundary components of the universal cover is either 0, 2 or ∞. As a sample application, we show that simple, thick, negatively curved P-manifolds of dimension ≥ 6 are topologically rigid. We include some straightforward consequences of topological rigidity (diagram rigidity, weak co-Hopf property, and the Nielson problem).
HOFER'S METRIC ON THE SPACE OF DIAMETERS
Authors: KHANEVSKY MICHAEL
Published: January 2010

The present paper considers Hofer's distance between diameters in the unit disk. We prove that this distance is unbounded and show its relation to Lagrangian intersections.
MORSE THEORY FOR EIGENVALUE FUNCTIONS OF SYMMETRIC TENSORS
Authors: VALERO CARLOS
Published: January 2010

Given a symmetric tensor on a real vector bundle of dimension two, we construct a space where this tensor corresponds to a scalar function. We prove that under certain regularity conditions such a space and the corresponding scalar function are smooth. We study the topology of this space for the case of surfaces and produce a version of Morse inequalities for symmetric tensors. We apply our results to the geometry of surfaces.
BikeNet
Authors: Eisenman Shane B. , Miluzzo Emiliano , Lane Nicholas D. , Peterson Ronald A. , Ahn Gahng-Seop , Campbell Andrew T.
Published: January 2010

We present BikeNet, a mobile sensing system for mapping the cyclist experience. Built leveraging the MetroSense architecture to provide insight into the real-world challenges of people-centric sensing, BikeNet uses a number of sensors embedded into a cyclist's bicycle to gather quantitative data about the cyclist's rides. BikeNet uses a dual-mode operation for data collection, using opportunistically encountered wireless access points in a delay-tolerant fashion by default, and leveraging the cellular data channel of the cyclist's mobile phone for real-time communication as required. BikeNet also provides a Web-based portal for each cyclist to access various representations of her data, and to allow for the sharing of cycling-related data (for example, favorite cycling routes) within cycling interest groups, and data of more general interest (for example, pollution data) with the broader community. We present: a description and prototype implementation of the system architecture based on customized Moteiv Tmote Invent motes and sensor-enabled Nokia N80 mobile phones; an evaluation of sensing and inference that quantifies cyclist performance and the cyclist environment; a report on networking performance in an environment characterized by bicycle mobility and human unpredictability; and a description of BikeNet system user interfaces.
Ottoman archives explorer
Authors: Yalniz Ismet Zeki , Altingovde Ismail Sengor , Güdükbay Uğur , Ulusoy Özgür
Published: January 2010

This article presents Ottoman Archives Explorer, a Content-Based Retrieval (CBR) system based on character recognition for printed and handwritten historical documents. Several methods for character segmentation and recognition stages are investigated. In particular, sliding-window and histogram segmentation methods are coupled with recognition approaches using spatial features, neural networks, and a graph-based model. The prototype system provides CBR of document images using both example-based queries and a virtual keyboard to construct query words.
Dietary Predictors and Plasma Concentrations of Perfluorinated Compounds in a Coastal Population from Northern Norway
Authors: Rylander Charlotta , Brustad Magritt , Falk Helena , Sandanger Torkjel M.
Published: January 2010

Dietary intake, age, gender, and body mass index were investigated as possible predictors of perfluorinated compounds in a study population from northern Norway (44 women and 16 men). In addition to donating a blood sample, the participants answered a detailed questionnaire about diet and lifestyle. Perfluorooctane sulfonate (PFOS) (29 ng/mL), perfluorooctanoate (PFOA) (3.9 ng/mL), perfluorohexane sulfonate (PFHxS) (0.5 ng/mL), perfluorononanoate (PFNA) (0.8 ng/mL), and perfluoroheptane sulfonate (PFHpS) (1.1 ng/mL) were detected in more than 95% of all samples. Of the dietary items investigated, fruit and vegetables significantly reduced the concentrations of PFOS and PFHpS, whereas fatty fish to a smaller extent significantly increased the levels of the same compounds. Men had significantly higher concentrations of PFOS, PFOA, PFHxS, and PFHpS than women. There were significant differences in PFOS isomer pattern between genders, with women having the largest proportion of linear PFOS. PFOS, PFHxS, and PFHpS concentrations also increased with age.
Intoxication after Extreme Oral Overdose of Quetiapine to Attempt Suicide: Pharmacological Concerns of Side Effects
Authors: Müller C. , Reuter H. , Dohmen C.
Published: January 2010

Quetiapine is an atypical antipsychotic approved for the treatment of patients with psychotic disorders. Since approvement several case reports about intoxication with quetiapine were linked mainly with tachycardia,QTc-prolongation, somnolence, and hyperglycemia. Here, we present the first case report of an intoxication with an extreme overdose of quetiapine (36 g), ingested by a 32-year-old female (62 kg bodyweight) to attempt suicide. Symptoms associated with intoxication were coma without arterial hypotension, persistent tachycardia, hyperglycemia, and transient hypothyreoidism.QTc-interval was moderately extended. Management consisted of intubation for airway protection, gastric lavage, the use of activated charcoal, i.v. saline, and observation for 17 hours on an intensive care unit. Despite the extremely high dose of quetiapine, the patient recovered completely without residual symptoms.
Fuzzy Modelling and Control of the Air System of a Diesel Engine
Authors: Simani S. , Bonfè M.
Published: January 2010

This paper proposes a fuzzy modelling approach oriented to the design of a fuzzy controller for regulating the fresh airflow of a real diesel engine. This strategy has been suggested for enhancing the regulator design that could represent an alternative to the standard embedded BOSCH controller, already implemented in the Engine Control Unit (ECU), without any change to the engine instrumentation. The air system controller project requires the knowledge of a dynamic model of the diesel engine, which is achieved by means of the suggested fuzzy modelling and identification scheme. On the other hand, the proposed fuzzy PI controller structure is straightforward and easy to implement with respect to different strategies proposed in literature. The results obtained with the designed fuzzy controller are compared to those of the traditional embedded BOSCH controller.
Cardiac Manifestations from Non-FIP1L1-PDGFR-Associated Hypereosinophilic Syndrome in a 13-Year-Old African American Boy
Authors: Salm Cindy M. , Clair Nicole E. St. , Lustig James V. , Samyn Margaret M.
Published: January 2010

Hypereosinophilic syndrome (HES) is a rare disorder typically seen in males, aged 20 to 50, with a predisposition for Caucasians. It is marked by overproduction of eosinophils (>1,500/L) and multiorgan system damage due to eosinophilic infiltration and mediator release. There are multiple variants of HES. Cardiac complications are more common in myeloproliferative HES associated with the FIP1L1-PDGFR mutation. Sequelae range from acute necrosis and thrombus formation to fibrosis of the endomyocardium.
We describe a young boy who presented with chest pain and dyspnea. A diagnosis of HES was made after all other etiologies of eosinophilia were excluded. Although he was found to be negative for the FIP1L1-PDGFR mutation, his cardiac complications included pericardial effusion and restrictive cardiomyopathy, without myocardial necrosis. Multi-organ involvement resulted in pericarditis, pleuritis, nephritis, and dermatitis. In this paper, we review his case and discuss the known subtypes of HES, the classic cardiac complications, and available treatment strategies.
Nonparametric Binary Recursive Partitioning for Deterioration Prediction of Infrastructure Elements
Authors: Pittou Mariza , Karlaftis Matthew G. , Li Zongzhi
Published: January 2010

This paper introduces binary recursive partitioning (BRP) as a method for estimating bridge deck deterioration and treats it as a classification and decision problem. The proposed BRP method is applied to the Indiana bridge inventory database containing 25 years of detailed information on approximately 5,500 bridges on state-maintained highways. Classification trees are separately created for 4 and 2 prediction classes and relatively high degrees of success are achieved for deck condition prediction. The significant variables identified as the most influential include current deck condition and deck age. The proposed method offers an alternative nonparametric approach for bridge deck condition prediction and could be used for cross comparisons of models calibrated using the widely applied parametric approaches.
Systems Design, Fabrication, and Testing of a High‐Speed Miniature Motor for Cryogenic Cooler
Authors: Acharya Dipjyoti , Zhou Lei , Zheng Liping , Wu Thomas X. , Kapat Jay , Chow Louis , Arakere Nagaraj K.
Published: January 2010

The long‐term storage of liquid hydrogen for space missions is of considerable interest to NASA. To this end, the Reverse Turbo‐Brayton Cryocooler (RTBC) is considerably lighter than conventional designs and a potentially viable and attractive solution for NASA′s long‐term Zero‐Boil‐off (ZBO) hydrogen storage system for future space missions. We present the systems design, fabrication, and performance evaluation of the Permanent Magnet Synchronous Motor (PMSM) powering a cryocooler capable of removing 20 W of heat at 18 K with a COP of 0.005 and driven by two 2‐kW permanent magnet synchronous motors operating at 200 000 rpm and at room temperature and 77 K. Structural, thermal, and rotordynamic aspects of system design are considered.
A Current Review of Targeted Therapeutics for Ovarian Cancer
Authors: Campos Susana M. , Ghosh Sue
Published: January 2010

Difficult to detect, ovarian cancer typically presents at an advanced stage. Significant progress has been achieved in the treatment of ovarian cancer with therapeutics focused on DNA replication or cell division. However, despite sensitivity to induction chemotherapy the majority of patients will develop recurrent disease. Conventional agents for recurrent disease offer little in terms of long-term responses. Various targeted therapeutics have been explored in the management of ovarian cancer. These include monoclonal antibodies to epidermal growth factor receptors, small molecule tyrosine kinase inhibitors, monoclonal antibodies directed at the vascular endothelial growth factor (bevacizumab), and the small tyrosine kinase inhibitors that target the vascular endothelial growth factor receptor. Recently, several other agents have come forth as potential therapeutic agents in the management of ovarian cancer. These include monoclonal antibodies to the folate receptor, triple angiokinase inhibitors, PARP inhibitors, aurora kinase inhibitors, inhibitors of the Hedgehog pathway, folate receptor antagonists, and MTOR inhibitors.