bluuebunny/crossref_metadata_2025 huggingface dataset:
A Simplified Integration System for the Fabrication of Total Surface Bearing Transtibial Socket by Employing Rapid Prototyping Technology
Authors: Hsu L. H. , Tzeng M. J. , Chen J. T.
Published: June 2012

This project is to validate the preliminary result of rapid prototyping (RP)-based transtibial socket that was reinforced by wrapping a layer of unsaturated polyester resin. By employing contemporary technologies including a scanner, computer-aided engineering systems, a rapid prototyping machine, together with the expertise of a prosthetist, RP-based prosthetic sockets with a comfortable fit to volunteer amputees can be fabricated. However, the expensive cost and complex procedure of using current commercial scanners and CAD systems will be barriers experienced by clinical professionals. As the existing service bureau infrastructure and cheaper RP technology are easily accessed, fabrication and technology cost barriers will be reduced. The remaining problems include the availability of easily-used CAD systems for designing prosthetic sockets, simple scanner and stump duplicating tool. This study therefore focuses on the integration of simplified systems including a vacuum forming tool, compact scanner and an interface system for designing prosthetic sockets. Although the type of PTB (patella tendon bearing) transtibial socket is widely adopted in plaster-based manual process, TSB (total surface bearing) sockets are more acceptable by amputees. Since the concept of TSB socket should obtain the stump mold of an amputee under appropriate pressure by using a specific stump forming tool, editing complex surfaces can be avoided when using a TSB-based stump model to design a socket. The quality of socket fit is expected to improve by a simplified design process in which an interface system based on grid-editing algorithms is utilized. In addition, cheaper RP technology, such as 3-D printing or droplet binding process, can be alternative means to fabricate RP-based prosthetic sockets. By combining TSB stump mold, simplified design process and a cheaper RP machine, this study proposes a simplified integrating system to manufacture RP stump mold. Using this RP stump mold together with the traditional lamination method of infiltrating resin into cotton layers, the RP-based transtibial sockets will then be fabricated easily. The expected result will demonstrate the feasibility of employing cheaper emerging technologies to assist an unskilled prosthetist who will be able to produce good quality of prosthetic socket.
Acoustic Emission Source Location During the Monitoring of Composite Fracture Using a Closely Arranged Sensor Array
Authors: Aljets Dirk , Chong Alex , Wilcox Steve
Published: June 2012

Acoustic Emission (AE) has become a powerful tool for Non-Destructive Testing (NDT) and Structural Health Monitoring (SHM) to identify and locate damage in engineering structures. Propagation cracks and other damages emit stress waves which can be detected by suitable sensors mounted on the structures surface. AE is becoming more and more popular for composite structures since it is not only able to monitor a relative large area at a time and without scanning but also because it is able to detect and potentially discriminate all different failure types such as matrix cracking, delamination and fibre breakage. In order to identify the location of AE sources in large plate-like structures it typically requires the use of at least three widely spaced sensors. The distance between these sensors is defined by, for example, expected AE intensity and attenuation of the signals. This paper presents AE monitoring results from a tensile test on a composite plate. The origin of each AE event was located using a novel configuration of the three sensors, which were installed in a closely arranged triangular array with the sensors just 45 mm apart. The algorithm locates AE sources by determining the direction from which the wave approaches the array using the time of arrival and the distance the wave has travelled using the wave mode separation. The test was conducted on a carbon fibre reinforced composite (CFRP) plate with anisotropic lay-up. The technique is particularly suitable for NDT and SHM applications where the close positioning of the sensors allows the array to be installed in one housing to simplify mounting and wiring.
A Method for Roughness and Texture Simulation via Tactile Displays
Authors: Mengoni Maura , Morichetti Paolo , Peruzzini Margherita , Germani Michele
Published: June 2012

This paper presents a tactile synthesis method to provide roughness and texture coarseness sensations using a selective stimulation approach implemented by a tactile display. Digitizing, elaborating and processing real material surfaces obtain signals. The selection of their frequency range is based on the reactive frequencies of SAI and FAI types receptors. An electro-tactile display provided with a mechanical vibration to stimulate FAII units located at the deeper skin layers has been developed. A SW tool allows to manage selective signals modulation and configuration according to the displayed material. The research aims at overcoming a crucial problem concerning the signals adopted by most electro-tactile displays to stimulate skin mechanoreceptors. The paper focuses on the description of the adopted method and of the implemented software tool to control the tactile display. Preliminary experimentations were carried out to measure the system’s latency, accuracy and reliability. Experimental sessions show a promising system response: minimal latency (30ms), good reliability (>98%) and acceptable accuracy (>70%).
Efficient Operational Space Sensitivity Analysis of Dynamic Multibody Systems
Authors: Mukherjee Rudranarayan M.
Published: June 2012

This paper presents a generalization of the divide and conquer algorithm for sensitivity analysis of dynamic multibody systems based on direct differentiation. While similar sensitivity analysis approach has been demonstrated for multi-rigid and multi-flexible systems in tree topologies and a limited set of kinematically closed loop topologies, this paper presents the generalization of these approaches to systems in generalized topologies including many coupled kinematically closed loops. This generalization retains the efficient complexity of the underlying formulations i.e. linear and logarithmic complexity in serial and parallel implementation. Other than the computational efficiency, the advantages of this method include concurrent sensitivity analysis with forward dynamics, no numerical artifacts arising from parametric perturbation and significantly reduced data storage compared to traditional methods. An interesting application of this work in control of multibody systems is discussed.
Application of Targeted Energy Transfer (TET) Techniques to the Seismic Protection of a Small Scale Multistorey Eccentric Steel Structure
Authors: Tripepi Concetta , Nucera Francesco , Bergman Lawrence A. , McFarland D. Michael , Vakakis Alexander F.
Published: June 2012

The aim of this work is to show that is possible to apply the Nonlinear Energy Sink (NES) concept to protect seismically excited eccentric steel structures through Targeted Energy Transfer (TET). We consider, as the primary (linear) system, a small-scale four-storey unsymmetrical-plan building, modeled as a twelve-degree-of-freedom-system, with floors sufficiently rigid so that the frame can reasonably be considered as shear-type and with additional eccentric mass for each floor. To the primary (linear) system, we connect two NESs, which are non-smooth and precisely the vibro-impact devices (VI-NESs), both placed on the top floor. In order to analyze the dynamics of the controlled model (structure with VI-NESs), we study the performance and the robustness of the augmented structure excited by a set of Eurocode8 (EC8) spectrum compliant earthquakes. Our purpose is to check the effectiveness of the VI-NESs to different earthquake excitations, that is, testing that an optimal VI-NES setting computed for a specific earthquake will still produce satisfactory results for the other earthquakes. We show that the nonlinear attachments are capable of engaging in transient resonance with linear modes at arbitrary frequencies by generating a one-way irreversible (on the average) transfer of the energy of vibration from the primary structure to local attachment. There the energy is confined and locally dissipated without “spreading” back to the main structure because of the instantaneous internal resonance. As energy decreases due to damping the conditions for Transient Resonance Capture (TRC) fail and escape from resonance capture takes place.
Review of Sensitivity Studies for Impressed Current Cathodic Protection Systems
Authors: DeGiorgi Virginia G. , Wimmer Stephanie A.
Published: June 2012

The Naval Research Laboratory has conducted investigations into the computational simulations of shipboard cathodic protection systems for several decades providing a scientific basis for the application of computational modeling to corrosion and signature systems. This work has expanded to other facilities and organizations, several of which are commercial in nature. However, much of the individual sensitivity studies which have led to an increased understanding of the behavior of cathodic protection systems have not had a high visibility. In this paper the authors review selected critical studies with notes towards future work. Because of their impact on modeling accuracy and means of defining components the authors have selected variations in electrolyte conductivity, damage modeling approaches, material characterization and paint characterization for review.
Identification of Equivalent Modal Damping and Frequencies in Multi Degree-of-Freedom Nonlinear Systems
Authors: Quinn D. Dane , Ott Richard J. , Hubbard Sean , McFarland D. Michael , Bergman Lawrence A. , Vakakis Alexander F.
Published: June 2012

We consider the response of a linear structural system when coupled to an attachment containing strong or even essential nonlinearities. For this system, the attachment is designed as a nonlinear vibration absorber, serving to dissipate energy from the structural system. Moreover, the attachment not only leads to a reduction in the total energy of the system, but also couples together the vibration modes of the linear structural system, thereby allowing for energy to also be redistributed among these structural modes of the system. The effect of the nonlinear attachment on the linear primary system can be quantified in terms of equivalent measures for the damping and frequency of each mode, derived through consideration of the energy in each mode. The identification of these equivalent measures is illustrated on a two degree-of-freedom primary system. Moreover, this procedure depends only on the time history of the response and is therefore suited to both simulation and experimental results.
A Low Cost Attitude and Heading Reference System Based on a MEMS IMU for a T-Quadrotor
Authors: Long Yangbo , Bai Shi , Patel Paras , Cappelleri David J.
Published: June 2012

Combining signals from accelerometers and gyroscopes is a widely used way to estimate robot attitude. However, when using a Kalman filter in this case, the measurements are vulnerable to dynamic accelerations which will result in substantial attitude estimation errors. The attitude acquisition method presented in this paper takes an attitude quaternion as system measurements and uses a Kalman filter to fuse signals from MEMS gyroscopes, accelerometers and magnetic sensors. In order to remove the influence of dynamic accelerations, when dynamic accelerations are found to be significant, a Quaternion-based Strapdown Navigation System (Q-SINS) algorithm is only applied without the Kalman filtering. When the dynamic accelerations are not significant, both the Q-SINS and the Bi-vector algorithms are utilized and fused using the Kalman filter for improved system performance. Compared with some other highly nonlinear and complicated attitude algorithms, the Attitude and Heading Reference System (AHRS) proposed in this paper is computationally less expensive and more suitable for real-time applications.
Damage Detection of Space Frame Structures With L-Shaped Beams and Bolted Joints Using Changes in Natural Frequencies
Authors: He K. , Zhu W. D.
Published: June 2012

It is difficult to use conventional non-destructive testing methods to detect damage, such as loosening of bolted connections, in a space frame structure due to the complexity of the structure and the nature of the possible damage. A vibration-based method that uses changes in the natural frequencies of a structure to detect the locations and extent of damage in it has the advantage of being able to detect various types of damage in the structure, including loosening of bolted connections. Since the vibration-based method is model-based, applying it to a space frame structure with L-shaped beams and bolted joints will face challenges ranging from the development of an accurate dynamic model of the structure to that of a robust damage detection algorithm for a severely under-determined, nonlinear least-square problem under the effects of relatively large modeling error and measurement noise. With the development of the modeling techniques for fillets in thin-walled beams (He and Zhu, 2009, “Modeling of Fillets in Thin-Walled Beams Using Shell/Plate and Beam Finite Elements,” ASME J. Vibr. Acoust., 131(5), p. 051002) and bolted joints (He and Zhu, “Finite Element Modeling of Structures with L-shaped Beams and Bolted Joints,” ASME J. Vibr. Acoust., p. 011010) by the authors, accurate physics-based models of space frame structures can be developed with a reasonable model size. A new damage detection algorithm that uses a trust-region search strategy combined with a logistic function transformation is developed to improve the robustness of the vibration-based damage detection method. The new algorithm can ensure global convergence of the iterations and minimize the effects of modeling error and measurement noise. The damage detection method developed is experimentally validated on an aluminum three-bay space frame structure with L-shaped beams and bolted joints. Three types of introduced damage, including joint damage, member damage, and boundary damage, were successfully detected. In the numerical simulation where there are no modeling error and measurrement noise, the almost exact locations and extent of damage can be detected.
Vibration Reduction in Large Flexible Systems Through Independent Modal Control
Authors: Braghin Francesco , Cinquemani Simone , Resta Ferruccio
Published: June 2012

Many systems have, by their nature, a small damping and therefore they are potentially subjected to dangerous vibration phenomena. The aim of active vibration control is to contain this phenomenon, increasing the damping of the system without changing its natural frequencies and vibration modes. A control of this type can improve the dynamic performance, reduce the vibratory phenomenon (and the resulting acoustic noise) and increase the fatigue strength of the system. The paper introduces a new approach to the synthesis of a modal controller to suppress vibrations in structures: it turns from the traditional formulation of the problem showing how the performance of the designed controller can be evaluated through the analysis of the resulting modal damping matrix of the controlled system. Such analysis allows to evaluate spillover effects, due to the presence of un-modeled modes, the stability of the control and the consequent effectiveness in reducing vibration. The ability to easily manage this information allows the synthesis of an efficient modal controller. Theoretical aspects are supported by experimental applications on a large flexible system.
An Accurate Spatial Discretization and Substructural Method With Application to Moving Elevator Cable-Car Systems: Part II—Application
Authors: Ren H. , Zhu W. D.
Published: June 2012

This paper uses the methodology developed in Part I of this work to study the longitudinal, transverse, and their coupled vibrations of moving elevator cable-car systems. A suspension cable is a one-dimensional length-variant distributed-parameter component. When there is only one suspension cable connected to the car, the car is modeled as a point mass. When there are multiple suspension cables, the car is modeled as a rigid body, and the rotation of the car is also included. There are complicated matching conditions between the cable and the car, which cannot be satisfied in the classical assumed modes method, but can be satisfied in the current method. Hence not only the longitudinal and transverse displacements, but also the internal forces/moment, such as the axial force, the bending moment, and the shear force, which are related to the spatial derivatives of the longitudinal and transverse displacements, are accurately calculated. The results from different choices of boundary motions and trial functions are essentially the same, and the convergence is much faster than that of the assumed modes method. The longitudinal-transverse coupled vibrations of a moving cable-car system are also studied using the current method, and the results are compared with those from the linear models. While the result from the linear model for the transverse vibration agrees well with that from the nonlinear coupled model, the axial force from the linear model can significantly differ from that from the nonlinear model when the car approaches the top of the hoistway.
UAVs Safe Landing Using Range Images
Authors: Frontoni Emanuele , Mancini Adriano , Zingaretti Primo
Published: June 2012

In this paper a mixed vision-range based approach, based on Kinect technology, for safe landing of an Unmanned Aerial Vehicle (UAV) is proposed. The guidance system allows a remote user to define target areas from an high resolution aerial or satellite image to determine the waypoints of the navigation trajectory or the landing area. The system is based on our previous work on UAV navigation and landing: a feature-based image matching algorithms finds the natural landmarks and gives feedbacks to the control system for autonomous navigation and landing. An algorithm for safe landing areas detection is proposed, based on the use of 4D RGBD (Red, Green, Blue, Distance) image analysis. The helicopter is required to navigate from an initial to a final position in a partially known environment, to locate a landing area and to land on it. Results show the appropriateness of the vision-based approach that does not require any artificial landmark (e.g., helipad) and is quite robust to occlusions, light variations and high vibrations.
Volumetric Contact Dynamics Models and Experimental Validation of Normal Forces for Simple Geometries
Authors: Boos Michael , McPhee John
Published: June 2012

A volumetric contact dynamics model has been proposed for the purpose of generating reliable and rapid simulations of contact dynamics. Forces and moments between bodies in contact can be expressed in terms of the volume of interference between the undeformed geometries. This allows for the modelling of contact between complex geometries and relatively large contact surfaces, while being computationally less expensive than finite element methods. However, the volumetric model requires experimental validation. Models for simple geometries in contact have been developed for stationary and dynamic contact; an apparatus has been developed to experimentally validate these models. This paper focuses on validation of the normal contact models. Measurements of forces and displacements will be used to identify the parameters related to the normal force, i.e. the volumetric stiffness and hysteretic damping factor for metallic surfaces. The experimental measurements are compared with simulated results to assess the validity of the volumetric model.
Near-edge x-ray absorption fine structure spectroscopy studies of charge redistribution at graphene/dielectric interfaces
Authors: Schultz Brian J. , Lee Vincent , Price Jimmy , Jaye Cherno , Lysaght Patrick S. , Fischer Daniel A. , Prendergast David , Banerjee Sarbajit
Published: June 2012

Charge redistribution at graphene/dielectric interfaces is predicated upon the relative positioning of the graphene Fermi level and the charge neutralization level of the dielectric. The authors present an angle-resolved near-edge x-ray absorption fine structure (NEXAFS) spectroscopy investigation of single-layered graphene transferred to 300 nm SiO2/Si with subsequent deposition of ultrathin high-κ dielectric layers to form graphene/dielectric interfaces. The authors’ NEXAFS studies indicate the appearance of a distinct pre-edge absorption for graphene/HfO2 heterostructures (but not for comparable TiO2 and ZrO2 constructs). The hole doping of graphene with substantial redistribution of electron density to the interfacial region is proposed as the origin of the pre-edge feature as electron depletion renders part of the initially occupied density of states accessible for observation via NEXAFS spectroscopy. The spectral assignment is validated by calculating the NEXAFS spectra of electron- and hole-doped graphene using density functional theory. In contrast, a similarly sputtered metallic TiN layer shows substantial covalent interfacial hybridization with graphene.
The Virus That Came In from the Cold
Authors: Bell John C.
Published: June 2012

A common-cold virus uses an undercover strategy to avoid neutralizing antibodies in cancer patients and targets distant sites of metastatic cancer growth.
Novel Method for Evaluating
In Vitro
Activity of Anidulafungin in Combination with Amphotericin B or Azoles
Authors: Teixeira-Santos R. , Rocha R. , Moreira-Rosário A. , Monteiro-Soares M. , Cantón E. , Rodrigues A. G. , Pina-Vaz C.
Published: June 2012

A combination of drugs possessing different targets has been used as salvage therapy, although without scientific support.
In vitro
studies validating such combinations are scarce, and the methodology is very laborious and time-consuming. This study proposes a flow cytometric (FC) protocol as an alternative to evaluate the effect of the combination of anidulafungin (AND) with amphotericin B (AMB) and azoles (fluconazole and voriconazole), tested upon 39 and 36
Candida
strains, respectively. The concentration assayed in the combination was 0.5× MIC of each drug. The membrane potential marker DiBAC
4
(3) [Bis-(1,3-dibutylbarbituric acid) trimethine oxonol] was used for AND-AMB, and the metabolic marker FUN-1 was used for AND-azoles. Drug interaction was determined by calculating a staining index (SI): the sum of the percentage of depolarized cells (DC) after treatment with drug combinations divided by the DC of the drug alone, and the sum of the mean intensity of fluorescence (MIF) displayed by cells treated with drug combinations divided by the MIF of the drug alone for FUN-1. An SI of <1 means antagonism, an SI between 1 and 4 means no interaction, and an SI of >4 means synergism. The combination of AND and AMB by FC and checkerboard was synergistic for 46 and 43% of isolates and antagonistic for 5 and 8%, respectively. For the combination of AND and azoles, it was synergistic for 36% and antagonistic for 3% by FC and synergistic for 44% and antagonistic for 3% by checkerboard. When the FC method was compared to the gold standard checkerboard method, the agreement was 0.91 (95% confidence interval [95% CI] of 0.88 to 0.94), sensitivity was 0.88 (95% CI of 0.73 to 0.95), and specificity was 0.95 (95% CI of 0.84 to 1). Thus, FC is a rapid and reliable method (<2 h) to assess the effect of antifungal combinations.
First Report of an Extensively Drug-Resistant VIM-2 Metallo-β-Lactamase-Producing Brevundimonas diminuta Clinical Isolate
Authors: Almuzara Marisa N. , Barberis Claudia M. , Rodríguez Carlos H. , Famiglietti Angela M. R. , Ramirez Maria S. , Vay Carlos A.
Published: June 2012

In the literature, only threeBrevundimonas diminutaenvironmental isolates carrying metallo-β-lactamase genes were recently published. However, so far, noB. diminutaclinical isolates carrying these carbapenem resistance genes have been described. Here we report the first VIM-2 metallo-β-lactamase-producingB. diminutaclinical isolate obtained from an immunocompromised patient.
Serial angiographic appearance of segmental arterial mediolysis manifesting as vertebral, internal mammary and intra-abdominal visceral artery aneurysms in a patient presenting with subarachnoid hemorrhage and review of the literature
Authors: Cooke Daniel L , Meisel Karl M , Kim Warren T , Stout Charles E , Halbach Van V , Dowd Christopher F , Higashida Randall T
Published: June 2012

Segmental arterial mediolysis (SAM) is a rare, non-inflammatory, non-atherosclerotic vasculopathy typically affecting the abdominal arteries although it may also affect the great vessels and cerebral vasculature. Diseased vessels manifest with aneurysms and/or dissections, often presenting clinically with catastrophic thromboembolic injury and less frequently with subarachnoid hemorrhage (SAH). The etiology of SAM remains indeterminate although there is evidence it may be an endogenous pathological response to vasospasm. The SAM literature is reviewed and a case of SAH related to a ruptured dissecting-type vertebral artery aneurysm is described. In addition to furthering awareness of SAM, this unique case offers insight into the acute phase of the disease and the potential role of vasospastic induction.
OBSERVATION OF REDUCTION IN CASIMIR FORCE WITHOUT CHANGE OF DIELECTRIC PERMITTIVITY
Authors: BANISHEV A. A. , CHANG C.-C. , CASTILLO-GARZA R. , KLIMCHITSKAYA G. L. , MOSTEPANENKO V. M. , MOHIDEEN U.
Published: June 2012

Additional information is provided on the effect of the significant (up to 35%) reduction in the magnitude of the Casimir force between an Au -coated sphere and an indium tin oxide film which was observed after UV treatment of the latter. A striking feature of this effect is that the reduction is not accompanied with a corresponding variation of the dielectric permittivity, as confirmed by direct ellipsometry measurements. The measurement data are compared with computations using the Lifshitz theory. It is shown that the data for the untreated sample are in a very good agreement with theory taking into account the free charge carriers in the indium tin oxide. The data for the UV-treated sample exclude the theoretical results obtained with account of free charge carriers. These data are found to be in a very good agreement with theory disregarding the free charge carriers in an indium tin oxide film. A possible theoretical explanation of our observations as a result of phase transition of indium tin oxide from metallic to dielectric state is discussed in comparison with other related experiments.
ENERGY DENSITY AND PRESSURE IN POWER-WALL MODELS
Authors: FULLING S. A. , MILTON K. A. , WAGNER JEF
Published: June 2012

A finite ultraviolet cutoff near a reflecting boundary yields a stress tensor that violates the basic energy-pressure relation. Therefore, a "soft" wall described by a power-law potential, which needs no ad hoc cutoff, is being investigated by the collaboration centered at Texas A&M University and the University of Oklahoma. Progress is reported here.
CASIMIR FRICTION FORCE FOR MOVING HARMONIC OSCILLATORS
Authors: HØYE JOHAN S. , BREVIK IVER
Published: June 2012

Casimir friction is analyzed for a pair of dielectric particles in relative motion. We first adopt a microscopic model for harmonically oscillating particles at finite temperature T moving nonrelativistically with constant velocity. We use a statistical-mechanical description where time-dependent correlations are involved. This description is physical and direct, and, in spite of its simplicity, is able to elucidate the essentials of the problem. This treatment elaborates upon, and extends, an earlier theory of ours back in 1992. The energy change ΔE turns out to be finite in general, corresponding to a finite friction force. In the limit of zero temperature the formalism yields, however, ΔE → 0, this being due to our assumption about constant velocity, meaning slowly varying coupling. For couplings varying more rapidly, there will also be a finite friction force at T = 0. As second part of our work, we consider the friction problem using time-dependent perturbation theory. The dissipation, basically a second order effect, is obtainable with the use of first order theory, the reason being the absence of cross terms due to uncorrelated phases of eigenstates. The third part of the present paper is to demonstrate explicitly the equivalence of our results with those recently obtained by Barton (2010); this being not a trivial task since the formal results are seemingly quite different from each other.
NONPERTURBATIVE T-MATRIX OPERATOR FOR SPIN–ORBIT SCATTERING BASED ON GENERIC SYMMETRY CONSIDERATION AND ITS RELEVANCE FOR ANOMALOUS AND SPIN HALL EFFECT
Authors: PAREEK T. P.
Published: June 2012

Using symmetry consideration and previous results in anomalous and spin Hall effect it is argued and shown that the effect of spin–orbit (SO) scattering is of nonperturbative nature. Moreover it is shown to be of higher relevance compared to potential disorder scattering and therefore should be taken into account first. Therefore building upon symmetry consideration we derive an (nonperturbative) exact T-Matrix operator for SO scattering. It is shown that due to SO scattering local spin polarization (local moment) appears which is missing in standard perturbative schemes. This has important consequence for anomalous velocity and spin accumulation which are illustrated. The appearance of local moment has a nontrivial effect on SU(2) gauge symmetry which is also discussed. This exact T-matrix will be helpful on building detailed Boltzmann type of theories which has the potential to clarify the intrinsic or extrinsic nature of anomalous and spin Hall effect.
TIGHTENING THE EAVESDROPPING ACCESSIBLE INFORMATION FOR CONTINUOUS VARIABLE QUANTUM KEY DISTRIBUTION PROTOCOLS THAT INVOLVE NONMAXIMALLY ENTANGLEMENT
Authors: BECIR A. , WAHIDDIN M. R. B.
Published: June 2012

In this paper, we derive tight bounds for the eavesdropping attacks on continuous variable quantum key distribution (CV-QKD) protocol that involves nonmaximally entangled states. We show that deriving bounds on the eavesdropper's accessible information based on the Heisenberg uncertainty yields upper bounds, but those bounds are not tight. For this reason, we follow different techniques to derive the desired tight bounds. The new bounds are tight for all CV-QKD protocols that involve two-mode entangled state. Our derivations are applied to direct and reverse reconciliation schemes of protocol implementation, respectively.
ON THE COMPLETE INFORMATION FIRST-PRICE AUCTION AND ITS INTUITIVE SOLUTION
Authors: ALCALDE JOSÉ , DAHM MATTHIAS
Published: June 2012

Despite the popularity of auction theoretical thinking, it appears that no one has presented an elementary equilibrium analysis of the complete information first-price sealed-bid auction mechanism when the bidding space has a finite grid. This paper aims to remedy that omission. We show that there always exists a "high price equilibrium" which can be considered "the intuitive solution" (an agent with the highest valuation wins the auction bidding at the second highest valuation). Although there might be other "low price equilibria," we also show that when there are two bidders "the intuitive solution" is the unique limiting equilibrium when the grid size goes to zero and ties are randomly broken.
FAST-GROWING SMEs AND THE ROLE OF INNOVATION
Authors: GRUNDSTRÖM CHRISTINA , SJÖSTRÖM ROLAND , UDDENBERG ANDERS , RÖNNBÄCK ANNA ÖHRWALL
Published: June 2012

In a study of 409 Swedish SMEs, the difference between the highest growing, which can be characterized as gazelles, and the lowest growing companies were examined regarding performance change over a four year period and what contributed to the growth from an innovation perspective. It was concluded that, besides growing, the highest growing companies also showed high profitability,increased number of employees, and significantly higher markets shares locally, nationally and internationally than the lowest growing companies. Several traits were found to contribute to this. The highest growing companies had a significantly higher portion of new products as part of the turnover during the four years studied and they perceived themselves as differentiating from their competitors concerning: (1) offering better products, (2) understanding customer needs better, (3) having a higher pace or being more agile, and (4) keeping costs down. They also found it more important to take risks, reinvest any profit, and to focus on growth than the lowest growing companies, and this regardless of industry.
ON THE CONSISTENCY OF SOME CRISP CHOICE FUNCTIONS BASED ON A STRONGLY COMPLETE FUZZY PRE-ORDER
Authors: FOTSO SIMEON , FONO LOUIS AIME
Published: June 2012

This paper presents the first part of a general study of the structure of nine preference-based choice functions introduced by Barrett et al.2 More precisely, we show that, as for crisp total pre-orders, first and last alternatives exist in a finite set of alternatives equipped with a strongly complete fuzzy pre-order. We use that result to characterize each of those crisp choice functions for crisp total pre-orders and strongly complete fuzzy pre-orders. We study, by means of those characterizations, the consistency of those preference-based choice functions when preferences are strongly complete fuzzy pre-orders (thereby crisp total pre-orders), that is, we check if each choice function satisfies or violates each of six consistency conditions introduced by Sen.11
SOLITON NATURE OF EQUILIBRIUM STATE OF TWO CHARGED MASSES IN GENERAL RELATIVITY
Authors: ALEKSEEV G. A. , BELINSKI V. A.
Published: June 2012

New derivation of static equilibrium state for two charged masses in General Relativity is given in the framework of the Inverse Scattering Method in contradistinction to our previous derivation of this solution by the Integral Equation Method. This shows that such solution is of solitonic character and represents the particular case of more general (12-parametric) stationary axisymmetric electrovacuum two-soliton solution for two rotating charged objects obtained by one of the authors in 1986. This result gives an additional support to our comprehension that the appropriate analytical continuations of solitonic solutions in the space of their parameters are always possible and that applicability of the Inverse Scattering Method in presence of electromagnetic field is not restricted only to the cases with naked singularities. The paper represents the shortened version of the plenary talk given at the Second Galileo - Xu Guangqi meeting (July 12-18, 2010, Ventimiglia, Italy).
ON EINSTEIN CLUSTERS
Authors: GERALICO ANDREA , POMPI FRANCESCA , RUFFINI REMO
Published: June 2012

The classification of Einstein clusters based on the analysis of the stability of circular orbits according to the effective potential theory is compared with that resulting from the application of the maximum binding energy criterion. The stability properties are investigated for different choices of the energy density profile. The cases of clusters with constant energy density, those characterized by arbitrarily large values of the central gravitational redshift and clusters with Burkert-type and Navarro-Frenk-White-type energy density profiles used in the literature to model galactic halos are discussed.
MODELLING THE CORE AND THE HALO OF GALAXIES BY FERMIONS
Authors: GERALICO ANDREA , RUFFINI REMO
Published: June 2012

The possibility to describe in a consistent way both the supermassive compact object at the center and the halo of galaxies is explored by assuming the existence of a self-gravitating semi-degenerate system of fermions in thermodynamical equilibrium.
CONSTRAINTS OF INITIAL DATA FOR A DISCRETE UNIVERSE
Authors: ROSQUIST KJELL , SAMUELSSON LARS
Published: June 2012

The matter distribution of the universe is observed to be discrete in the form of stars, galaxies and clusters of galaxies. Due to the non-linearities of the Einstein field equations, the discrete nature of the matter implies modifications of the standard Friedmann cosmology paradigm. The modifications affect both the dynamics and the possible cosmological initial data. We discuss properties and restrictions for the intial data of a universe with a discrete matter distribution, in particular possible implications for the curvature and topology.
THE CHARACTERISTICS OF GRBs WITH PRESENCE OF HIGH ENERGY COMPONENT IN THEIR SPECTRA
Authors: ARKHANGELSKAJA IRENE V.
Published: June 2012

The properties of GRBs with presence of high energy emission in spectra are discussed.

The temporal profiles of part of events are similar in various energy bands in prompt phase (as for GRB 080528, GRB 021008) but during some events extended high energy emission was detected (for example, GRB 090902B). For other part of GRBs temporal profiles are quite different in various energy bands during prompt phase (as for GRB 050525B), but for some such events extended high energy emission was observed too – for example, GRB 080514B. Moreover, high energy precursors were registered for several GRBs: some photons in energy band 30 MeV - 30 GeV were detected by AGILE during GRB 080514B.

The shape of energy spectra of GRBs with presence of high energy emission can follows the Band model (or power law or broken power law) up to some tens or hundreds of MeV (as for GRB 021008) or contains additional high energy power law component (for example, GRB 050525B and GRB 090902B). Following this criteria it is possible to separate two main subclasses of GRBs with high energy emission. Both types of GRBs observed since CGRO mission beginning. The analysis of their energy spectra has shown that the break between additional high energy component and Band (or power law or broken power law) component was in energy region 2-200 MeV.

Both types can have got extended high energy emission including component with E > 500 MeV for some events and low energy precursors. The special features of second class of GRBs by the results of preliminary data analysis are the absence of hard to soft evolution in the low energy band and (or) presence of the high energy precursors for some events.
EQUILIBRIUM ORBITS OF PARTICLES UNDERGOING POYNTING-ROBERTSON EFFECT IN SCHWARZSCHILD SPACETIME
Authors: BINI DONATO , GERALICO ANDREA
Published: June 2012

Equilibrium orbits of particles moving on the equatorial plane of a Schwarzschild spacetime are investigated when a test radiation field is superposed to the background gravitational field. The radiation flux is endowed with a fixed but arbitrary (non-zero) angular momentum. It is found that multiple equilibrium circular orbit exist provided that the photon angular momentum is sufficiently high. The stability of such orbits is also analyzed.
THE TIANLAI PROJECT: A 21CM COSMOLOGY EXPERIMENT
Authors: CHEN XUELEI
Published: June 2012

In my talk at the 2nd Galileo-Xu Meeting, I presented several different topics in 21cm cosmology for which I have done research. These includes the 21cm signature of the first stars1,2, the 21cm signal from the IGM and minihalos3, effect of dark matter annihilations on 21cm signal4, the 21cm forest by ionized/neutral region5, and the 21cm forest by minihalo and earliest galaxies6,7. In this conference proceeding I shall not repeat these discussions, but instead focus on the last part of my talk, i.e. the Tianlai project, an experiment effort on low redshift 21cm intensity mapping observation for dark energy measurements.
TORTOISE COORDINATE TRANSFORMATION ON APPARENT HORIZON OF A DYNAMICAL BLACK HOLE
Authors: LIU XIANMING , ZHAO ZHENG , LIU WENBIAO
Published: June 2012

Thinking of Hawking radiation calculation from a Schwarzschild black hole using Damour-Ruffini method, some key requirements of the tortoise coordinate transformation are pointed out. Extending these requirements to a dynamical black hole, a dynamical tortoise coordinate transformation is proposed. Under this new dynamical tortoise coordinate transformation, Hawking radiation from a Vaidya black hole can be got successfully using Damour-Ruffini method. Moreover, we also find that the radiation should be regarded as originating from the apparent horizon rather than the event horizon at least from the viewpoint of the first law of thermodynamics.
INFLATION IN A GENERAL REIONIZATION SCENARIO
Authors: PANDOLFI STEFANIA
Published: June 2012

Inflation predicts primordial scalar perturbations with a nearly scale-invariant spectrum and a spectral index approximately unity (the Harrison–Zel'dovich (HZ) spectrum). The first important step for inflationary cosmology is to check the consistency of the HZ primordial spectrum with current observations. Recent analyses have claimed that a HZ primordial spectrum is excluded at more than 99% c.l. Here we show that the HZ spectrum is only marginally disfavored if one considers a more general reionization scenario. Data from the Planck mission will settle the issue.
Atomically Dispersed Supported Metal Catalysts
Authors: Flytzani-Stephanopoulos Maria , Gates Bruce C.
Published: June 2012

Our aim in this review is to assess key recent findings that point to atomically dispersed noble metals as catalytic sites on solid supports, which may be viewed as ligands bonded to the metal. Both zeolites and open metal oxide supports are considered; the former offer the advantages of uniform, crystalline structures to facilitate fundamental understanding, and the latter offer numerous advantages in applications. The notion of strong interactions between metals and supports has resurfaced in the recent literature to explain how subnanometer clusters and even atoms of noble metals such as platinum and gold survive under often harsh reaction conditions on some supports, such as ceria and perovskites. Individual cations of platinum, palladium, rhodium, or other metals anchored to supports through M–O bonds can be formed on these supports in configurations that are stable and catalytically active for several reactions illustrated here, notably, oxidation and reduction. The development of effective synthesis methods and the identification of suitable stabilizers and promoters are expected to lead to the increasing application of atomically dispersed noble metal catalysts for practical processes characterized by efficient resource utilization and cost savings.
Experimental Methods for Phase Equilibria at High Pressures
Authors: Dohrn Ralf , Fonseca José M.S. , Peper Stephanie
Published: June 2012

Knowledge of high-pressure phase equilibria is crucial in many fields, e.g., for the design and optimization of high-pressure chemical and separation processes, carbon capture and storage, hydrate formation, applications of ionic liquids, and geological processes. This review presents the variety of methods to measure phase equilibria at high pressures and, following a classification, discusses the measurement principles, advantages, challenges, and error sources. Examples of application areas are given. A detailed knowledge and understanding of the different methods is fundamental not only for choosing the most suitable method for a certain task but also for the evaluation of experimental data. The discrepancy between the (sometimes low) true accuracy of published experimental data and the (high) accuracy claimed by authors is addressed. Some essential requirements for the generation of valuable experimental results are summarized.
Membrane Materials for Addressing Energy and Environmental Challenges
Authors: Drioli Enrico , Fontananova Enrica
Published: June 2012

Our modern society must solve various severe problems to maintain and increase our quality of life: from water stress to global warming, to fossil fuel depletion, to environmental pollution. The process intensification (PI) strategy is expected to contribute to overcoming many of these issues by facilitating the transition from a resource-intensive to a knowledge-intensive industrial system that will guarantee sustainable growth. Membrane operations, which respond efficiently to the requirements of the PI strategy, have the potential to replace conventional energy-intensive separation techniques, which will boost the efficiency and reduce the environmental impact of separations as well as conversion processes. This work critically reviews the current status and emerging applications of (integrated) membrane operations with a special focus on energy and environmental applications.
Nanocrystals for Electronics
Authors: Panthani Matthew G. , Korgel Brian A.
Published: June 2012

Semiconductor nanocrystals are promising materials for low-cost large-area electronic device fabrication. They can be synthesized with a wide variety of chemical compositions and size-tunable optical and electronic properties as well as dispersed in solvents for room-temperature deposition using various types of printing processes. This review addresses research progress in large-area electronic device applications using nanocrystal-based electrically active thin films, including thin-film transistors, light-emitting diodes, photovoltaics, and thermoelectrics.
Simultaneous Occurrence of Erythema Nodosum in Monozygotic Twin Sisters
Authors: Babamahmoodi Farhanag , Babamahmoodi Abdolreza , Barani Hamidreza , Delavarian Leila
Published: June 2012

Erythema nodosum (EN) is the most frequent clinicopathologic variant of panniculitis with painful red or violaceous nodules on the anterior surfaces of the legs. The condition is a cutaneous reaction that might be associated with a wide variety of disorders or might be caused by medications that produce painful nodules on the shins, and less commonly on the thighs and forearms. In this paper, we describe, for the first time in the world, erythema nodosum as the simultaneous presenting complaint of monozygotic twin sisters after streptococcal pharyngitis. This paper might support the effect of heredity in the occurrence of erythema nodosum.
Methotrexate Increases Skeletal Muscle GLUT4 Expression and Improves Metabolic Control in Experimental Diabetes
Authors: Russo Giuseppina T. , Minutoli Letteria , Bitto Alessandra , Altavilla Domenica , Alessi Eugenio , Giandalia Annalisa , Romeo Elisabetta L. , Stagno Maria Francesca , Squadrito Francesco , Cucinotta Domenico , Selhub Jacob
Published: June 2012

Long-term administration of 5-aminoimidazole-4-carboxamide ribonucleoside (AICAR) mimics the effects of endurance exercise by activating AMP kinase and by increasing skeletal muscle expression of GLUT4 glucose transporter. AICAR is an intermediate in the purinede novosynthesis, and its tissue concentrations can be increased,in vivo, by low doses of methotrexate (MTX) through the inhibition of the enzyme AICAR transformylase. We report here the first evidence that, in experimental type 2 diabetes, chronic treatment with low doses of MTX increases skeletal muscle GLUT4 expression and improves metabolic control. MTX (0.5 mg/kg body weight) or vehicle was administered intraperitoneally, once a week for 4 weeks, to genetically diabetic female C57BL/KsJ-m+/+Leptdbmice (db+/db+) and their normoglycemic littermates (db+/+m). In thedb+/db+mice, MTX treatment was associated with a ∼2-fold increase in skeletal muscle GLUT4 protein concentration and a >4-fold increase in GLUT4 mRNA expression (P<0.01, all), as compared to vehicle-treated mice; no significant differences were noted in controls. MTX treatment was also associated with a significant reduction of glucose and insulin serum concentrations in diabetic mice (P<0.001), and glucose levels only (P<0.05) in controls. These data indicate a different route to increase skeletal muscle GLUT4 expression, through the potential inhibition of the enzyme AICAR transformylase.