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The accident of modal characteristics directly provides an indication of structural damage. Based on changes in structural frequencies and mode shapes, a virtual flexibility matrix(VFM) technique is proposed in this paper for detecting damage locations and their severity. The method is applied at an element level with a conventional finite-element model. The element damage index is established from the changes of the generalized strain in element’s undamaged and damaged modes. The severity of...
Topics: Damage, Structures, Modal Analysis, Virtual Flexibility Matrix (VFM), Identification
Studies on the effect of different types of solvent for the extraction of bioactive compounds from the white-rot fungi have been investigated. Results showed that 70% (v/v) methanol-water system provided the maximal extraction yield at 41.47% and 52.48% for S. commune and P. sanguineus, respectively. Fick’s second law was used to calculate the predicted diffusion coefficient during the extraction process. For S. commune, the Dfast and Dslow obtained were 7.04 x 10-7 m2/h and 8.42 x 10-8 m2/h....
Topics: Schizophyllum Commune, Pycnoporus Sanguineus, Extraction, Yield, Kinetic
The biosorption of copper (II) ions onto Luffa cylindrica was investigated. Luffa cylindrica, a biomaterial with wide distribution particularly in the tropical world, is characterized with the surface area, chemical bonds, bulk density, pore size distribution, microstructures, composition, morphology and elemental composition which are determined. Biosorption studies were carried out with varying dosage and the experimental data obtained were fitted to Pseudo-Second order kinetic model. The...
Topics: Sorption Capacity, Luffa Cylindrica, Biosorption, Mathematical Modelling, Artificial Neural Network
 Prey predator population dynamics has been frequently studied in literature to model many robust but contrastive biological populations. In this paper, based on prey predator population dynamics, a nonlinear model to predict the behavior of virus treatment of cancer cells is suggested. Based on the goals of virus curing and consideration of some practical issues, the suggested model has the capability to cover these following cases: both cancer cells and viruses vanish, one is eliminated by...
Topics: Cancer Tumours, Virus Therapy, Limit Cycle, Bifurcation, Predator Prey Model
Folkscanomy: General Academic Papers
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A cohesive zone model (CZM) is presented for material fatigue analysis. This cyclic CZM contains a damage variable as well as a new evolution law. Considering the influence of the constraint condition for CZM, the triaxiality factor is involved in this model, too. The new cyclic CZM can describe the different damage evolution mechanisms in the fatigue crack initiation and fatigue crack growth process. A unique set of model parameters is used. The material damage parameters included in the...
Topics: Cohesive Zone Model, Damage Evolution, Triaxiality Dependence, Low Cycle Fatigue
 Enterococcus faecalis is a leading cause of bacterial persistence root canal infections. These bacteria have the ability to invade dentinal tubule size which is very small between 1-3μm causing difficulty drug penetration to eliminate root canal. 2% Chlorhexidine is recommended as a remedy to eliminate root canal bacteria. Root canal drugs should remain stable in solution and remain active despite the blood, serum and tissue protein derivatives. Necessary efforts to protect the root canal...
Topics: Microencapsulation, Chlorhexidine
 Impact mixed-mode I/II fracture experiments were carried-out on rigid foam using single edge notched bend (SENB) specimens with inclined notch. A drop-weight rig was used to perform the low-velocity impact fracture tests. SENB specimens with different notch inclination were tested at various impact potential energies by varying the drop-height in order to determine the critical impact potential energy at which the crack growth is initiated from the notch tip. Three-dimensional linear-elastic...
Topics: Low-velocity Impact, Fracture Behavior, Rigid Foam, Strain Energy Release Rate
Folkscanomy: General Academic Papers
Aug 31, 2016
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A new formula of experimental evaluation of the stress intensity factor was proposed depending on the area of the caustic. From series of experiments, which were performed in single edge-cracked specimens made of Lexan (PCBA), it was found that the values of the stress intensity factor KI,, which were based on the diameters of the caustics, were varied with the load, the crack length and the caustic shape because the caustic become oval in higher loads or higher crack lengths. This means that...
Topics: Cracks, Caustics, Caustics Crea, Stress Intensity Factors, Contact Problems
 TiAlBN nanocomposite coating have been deposited by varying nitrogen-to-total gas flow rate ratio (RN) of 5, 15, 20, 25%, and varying substrate temperature of 100, 200, 300, and 400 °C. The coating was deposited on AISI 316 substrates using radio frequency (RF) magnetron sputtering with single Ti-Al-BN hot-pressed target. The crystallographic phase, structural, and grain size was evaluated using glancing angle X-ray diffraction analysis (GAXRD). The corrosion behavior of the coating was...
Topics: TiAlBN, Nanocomposite, GAXRD, Polarization, Grain Size, Corrosion Potential, Corrosion Current...
 The increased use and research on direct composite restorations materials are mainly attributed to the demand for esthetic and excellent strength restorations. Early composites that were used for restoration process tend to had unfavorable properties, such as weak and having bad interaction with teeth interface. Combination of metakaolin-zirconia-apatite can yield a very good composite for teeth restoration application. It produces high hardness and good interaction with the teeth. The...
Topics: Restoration, Teeth, Nanocomposite, Hardness, Shrinkage
Folkscanomy: General Academic Papers
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 In view of the mechanics problems of the thick-walled open-sectional structural members that cannot be dealt with by existing beam theories, a novel computational methodology named Finite Nodal-Line Method (FNLM) is developed to perform the analysis of the thick-walled open-section beam with a length-aspect ratio less than 3. The computational results coming from an example of L-shaped thick-walled beam have verified the validity of the FNLM.
Topics: Thick Walled Open Section Beam, Finite Nodal-line Method, Non-uniform Torsion, Torsional Center,...
This paper discusses the wavelet-based Finite Difference Time Domain (FDTD) method and a tunable high resolution estimator with a specific problem of sound wave propagation through phononic crystals. If the band structures of a phononic crystal are calculated by the traditional FDTD method combined with the fast Fourier transform (FFT), some disadvantages, such as time consuming and the numerical instability of FDTD iterations are encountered. Moreover, good frequency estimation can only be...
Topics: Wavelet, Phononic Crystal, Finite Difference Time Domain, Tunable High Resolution Estimator
Folkscanomy: General Academic Papers
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 This paper discusses a problem about dynamic system identification over computer networks. A method to identify mathematical models of controlled objects over computer networks is proposed based on modified 1bit delta-sigma transformations and least squares methods for ARX models. The efficacy of the proposed method is verified based on numerical simulations and experiments. In the experiments, mathematical models of a DC motor are identified by using input-output signals of the DC motor over...
Topics: System Identification, Delta-Sigma Transformation, Least Squares Methods, ARX Models, Computer...
We investigate the profiles of diagonal components of static linear (xx and yy), and first nonlinear (xxx and yyy), optical responses of repulsive impurity doped quantum dots. The dopant impurity potential assumes Gaussian form. The dopant is considered to be propagating under damped condition which is otherwise linear inherently. The study principally puts emphasis on investigating the role of damping strength on the static polarizability components. In view of this the doped dot...
Topics: Quantum dot, Impurity, Static Polarizability, Damping, Dopant Propagation, Confinement Potential
In this communication, we present some results on thermo-electric properties of various high temperature superconductors. We have performed measurements on three rare-earth based cuprate superconductors. All the superconductors were prepared using solid state reaction method. The XRD studies on the present samples indicate that all the samples are in single phase. We observe that among the rare-earths studied in the present work, Gd-123 has the highest value of Z. In fact around 200K, the...
Topics: High Temperature Superconductors, Doping, Figure of Merit
 We are investigating the accuracy of various techniques for representing the temperature profile inside a fuel pin. The simplest approach consists to replace the temperature profile by a single effective temperature. Here, we propose to treat explicitly the temperature gradient in fuel pins, using a subgroup self-shielding model together with various representations of the temperature correlation effect between different isotopes and fuel regions. We conclude that it is now possible to use an...
Topics: Lattice Calculation, Resonance Self-shielding, Doppler Effect, Computational Schemes
 A scheme of direct time-domain extrapolation to far fields in half-space by finite-difference time-domain (FDTD) method was proposed, called the time-domain three-wave extrapolation that was in agreement with the nature of FDTD. The result for scattering from a perfectly conducting circular cylinder in half-space validated the proposed scheme.
Topics: FDTD Method, Half-space, Time-domain Extrapolation
Folkscanomy: General Academic Papers
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 This paper reviewed the history of sequential advances of the physical concepts regarding the vacuum space in different ages. There are three widely divergent physical concepts about the vacuum space; the first one of which is based on the old classical physics that the vacuum space is absolutely empty space while the second is the transition thought that this space is filled up with some unknown material called ether. However, the lack of concrete investigational support, leads to the...
Topics: Vacuum Space, Classical Physics, Quantum Physics, Nano-scale Activities
With the help of the measurements (the methods are the NMR 1H and 13C, infrared (IR) and the UV-absorption, Raman scattering of light, the fluorescence and the phosphorescence, Generation radiated of light, the pumping of the lasers and lamps, the low-temperature spectroscopy in the solutions and vapors and also with application by the methods of the rate balance of populations and deactivation the energy of pumping in the electronic excited states, and the spectroscopy of properties in the...
Topics: Spectra, Optical, Photophysic, Electronic Excited States, Dye-laser, Nanocurrent, Quantum Yields,...
Folkscanomy: General Academic Papers
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This work presents a new approach to find the exact solutions for the free vibration analysis of a beam based on the Timoshenko type with different boundary conditions. The solutions are obtained by the method of Lagrange multipliers in which the free vibration problem is posed as a constrained variational problem. The Legendre orthogonal polynomials are used as the beam eigenfunctions. Natural frequencies and mode shapes of various Timoshenko beams are presented to demonstrate the efficiency...
Topics: Timoshenko Beam, Natural Frequencies, Mode Shapes, Legendre Polynomials, Lagrange Multipliers
 Within the framework of a model representing the potential of a graphene sheet U(z) as an electro-neutral layer formed by smeared carbon atoms, the effect of this potential on spectral characteristics of atoms adsorbed on a graphene sheet has been studied. Since the distance between the adsorbed atom nucleus and sheet surface significantly exceeds the radii of inner atomic shells, the potential U(z) makes influence on the continuum wave functions only. Their behavior in the upper semi-space...
Topics: Photoionization, Atom, Graphene, Angular Distribution
The problem under consideration concerns information extraction from eukaryotic DNA sequences regarding existence of protein coding regions. Spectral Analysis using classical Fourier Transform techniques such as Discrete Fourier Transform (DFT) has long been used for this purpose with the help of period-3 peaks. Since this method has low Signal to Noise Ratio (SNR), the spectral peaks are difficult to distinguish in the background of noise. Researchers have designed various types of filters to...
Topics: Non-parametric, Periodogram, Power Spectral Density, Codon, Principal Component Analysis,...
 The problem under consideration concerns information extraction from eukaryotic DNA sequences regarding existence of protein coding regions. Spectral Analysis using classical Fourier Transform techniques such as Discrete Fourier Transform (DFT) has long been used for this purpose with the help of period-3 peaks. Since this method has low Signal to Noise Ratio (SNR), the spectral peaks are difficult to distinguish in the background of noise. Researchers have designed various types of filters...
Topics: Non-parametric, Periodogram, Power Spectral Density, Codon, Principal Component Analysis,...
In a companion paper [Unal, Stull, Williams, 2013], the parametric uncertainty in a thermal conductivity model of uranium oxide fuel was assessed using Markov Chain Monte Carlo (MCMC) analysis. This paper presents a similar assessment using an independent methodology aimed at examining the predictive capability of the empirically-derived thermal conductivity model adopted in [Unal, Stull, Williams, 2013]. The methodology considers the effect of uncertain parameters – a plausible reality in...
Topics: Nuclear, Info-Gap Decision Theory, Reactor, Parametric, Uncertainty, Thermal Conduction, Uranium...
 In the absence of a well-accepted, mathematical description of how units of material respond to one or more external actions, scientists must often rely upon empirically-derived models to make predictions. These models are often employed to model very complex phenomena with an unfortunate side-effect that intuition, as to the values of particular model parameters, may not serve to guide their use. Given our increased reliance on modeling and simulation to make predictions in the absence of...
Topics: Nuclear, Markov Chain Monte Carlo, Reactor, Parametric, Uncertainty, Thermal Conduction, Uranium...
In a series of papers by Smirnova and Hayakawa, fractal analyses of the ULF emissions in the frequency range of f = 0.001–0.3 Hz have been performed based on the geomagnetic data obtained in seismic active regions including Guam Island and Izu Peninsula. A certain dynamics of the spectrum slopes and the corresponding first-order fractal dimensions have been revealed in relation to the preparation phase of some strong earthquakes (EQs). In order to advance such a fractal approach which seems...
Topics: Earthquake Precursor, Ground-based Geomagnetic Observations, Multifractal Approach, Earthquake...
This paper presents a study on optimization of process parameters using genetic algorithm to reduce the transverse distortion in 304 L stainless steel butt welded plates. Distortion, the major problem in welded plates, results from the expansion and contraction of the weld metal and adjacent base metal during the heating and cooling cycle of the welding process. During this heating and cooling cycle, many factors affect shrinkage of the metal and lead to distortion, such as physical and...
Topics: Arc Welding, 304L Stainless Steel, Distortion, Finite Element, Genetic Algorithm
The interaction of carbon monoxide with the gold monomer in two oxidation states 0 and +1 both in the gas phase and on an NaY zeolite support is studied using density functional theory (DFT).Three structures of the zeolite having different Na ion loading are considered.CO vibrational frequency shows a blue shift on going from the oxidation state 0 to +1.The CO binding energy values of 1.19 and 1.21 eV for the oxidation state 0 are higher than the corresponding values in the oxidation state...
Topics: NaY Zeolite, Gold Monomer, CO Adsorption, Density Functional Theory
 In this paper, the design, construction and results of test as well as numerically simulation of a solar powered zeolite 4A-water adsorption refrigeration were presented. The performance of the designed and constructed system was investigated and numerically simulated using Zaria weather data obtained in a typical meteorological year (TMY) format while the design was modeled and simulated using Transient system simulation (TRNSYS) software. The simulation results showed that for a typical...
Topics: Adsorption System, Zeolite 4A –Water, Experiment, Performance, Simulation
Continuous cross-sectional analysis of atomic force microscope (AFM) images of several types of hybrids of DNA and carbon nanotubes (CNT) has been demonstrated. When conventional cross-sectional analysis was employed, the difference in surface roughness between chemical vapor deposition (CVD)-produced single-walled nanotubes (SWNTs) and high-pressure carbon monoxide (HiPco)-produced SWNT could not be distinguished. However, when continuous cross-sectional analysis was carried out using homemade...
Topics: Carbon Nanotube, DNA, Atomic Force Microscopy, Cross-Section, Binarization, Surface Morphology
Folkscanomy: General Academic Papers
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This paper presents the optimization process of MR – magnetorheological brake in order to define its configuration, and to reach the requested vehicle braking torque. FEM analysis previously carried out, concerning structural sizing of such a brake, showed that both braking torque and brake mass did not satisfy the requirements. Due to the necessity of limitation on the suspended mass of a motor vehicle, the optimization of the form of MR brake stator has been executed, including...
Topics: Magnetorheological Brake, FEM Optimization, Magnetic FEM, Thermal FEM, Fade Braking Test
 The classical method for counting platelets (Thrombocytes) is use of two types of microscopy: Burcker Turk chambers (hemacytometer) and slides with peripheral blood smears. In the last ten years, a new method, flow cytometry with application of the impedance principle has been developed for CBC and counting of platelets. Scope: The current studies sought to compare the results of platelet counts from the optic microscope with the values obtained by use of flow cytometry and the impedance...
Topics: Variation Coefficient, %Diff-differential Percent, SD-standard Deviation, VCS Technology -Volume,...
In this contribution, the unsteady, viscous and two dimensional flow over a plunging NACA0012 airfoilwas simulated using a high-order numerical method associated with a moving frame of reference technique. The goal of using a high-order numerical method is to characterize heaving airfoil wakes with very fine temporal and spatial resolutions. This characterization is essential in understanding the transition process in which oscillating airfoils undergone can enable more control on the...
Topics: Computational Fluid Dynamics, Boundary Layer, Oscillating Airfoils, Spectral/Hp Element Methods,...
A monolayer of carbon is called graphene. It exhibits unusual properties in the Hall effect and in the cyclotron resonance. It is found that it exhibits fractional charge in the Hall effect. The interactions amongst electrons almost become constant at low temperatures. Hence, the Kohn's theorem, which shows that the interactions do not play much role in determining the cyclotron resonance, becomes operative at low temperatures. The experiments on graphene do not depend on the wave vector...
Topics: Graphene, Kohn’s Theorem, Quantum Hall effect, Hubbard Model
 In general, the thermal-convection (Navier-Stokes and energy) equations are nonlinear partial differential equations that in most cases require the use of complex algorithms in combination with opportune discretization techniques for obtaining reliable numerical solutions. There are some cases, however, in which such equations admit analytical solutions. Such exact solutions have enjoyed a widespread use in the literature as basic states for determining the linear stability limits in some...
Topics: Thermal Convection, Navier-Stokes Equations, Analytic Solutions
Folkscanomy: General Academic Papers
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Nonlinear transmission lines (NLTL) that consist of coplanar waveguide periodically loaded with resonant tunnel diode are capable of shaping signal waveforms during transmission. Such system is the basis of very interesting microwave signal generation circuits and it has a lot of applications in electronics. Pspice is used to model analog to digital converter by generating short electrical pulses on a nonlinear transmission line. Nonlinear transmission line is realized as electrical lattice...
Topics: Nonlinera Transmission Line, Resonant Tunneling Diode, Signal Reshaping, Analog to Digital Converter
Folkscanomy: General Academic Papers
Aug 31, 2016
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In order to solve the problem that bispectrum has large amount of information, which is unfavorable for classification. A method that extract rolling characteristics of spectrum diagonal as features to recognize target using the SVM classifier is presented. Human echo is simulated by using finite difference time domain (FDTD) algorithm based on precise human 3D entity model. The effectiveness of the proposed method is proved.Finally measured data from ultra-Wide Bandwidth(UWB) radar proved the...
Topics: Ultra-wide Bandwidth, Multi-Angle, Limited finite difference time domain (FDTD), Higher-order...
Folkscanomy: General Academic Papers
Aug 31, 2016
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In order to solve the problem that bispectrum has large amount of information, which is unfavorable for classification. A method that extract rolling characteristics of spectrum diagonal as features to recognize target using the SVM classifier is presented. Human echo is simulated by using finite difference time domain (FDTD) algorithm based on precise human 3D entity model. The effectiveness of the proposed method is proved.Finally measured data from ultra-Wide Bandwidth(UWB) radar proved the...
Topic: UWB Multi-Angle Human Posture Recognition
Folkscanomy: General Academic Papers
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 A method for classifying types of brain activity in magnetoencephalographic (MEG) signals is proposed. Sources of abnormal cortical activity are localized by performing a generalized spectral analysis in the space of Fourier coefficients of the expansions of recorded signals in adaptive orthogonal bases. The basic principles of the method are discussed, and the results of its application to actual MEG records are presented for functional brain mapping in normal and pathological states.
Topics: Biomagnetic field, Magnetoencephalography, Generalized spectral-analytical method, Sources...
:  This paper presents an electromagnetic velocity (EMV) gauge technique which allowsuse of conductive samples in the measurement of material velocity subject to shockwave compression. A dynamic model of the induced current in the EMV gauge caused by the conductive samples moving in a uniform magnetic field is developed and the motional emf generated in the EMV gaugeis extracted from the measured signal. Experimental results are presented and discussed to demonstrate the effectiveness of the...
Topics: Electromagnetic Velocity Gauging, Shockwave, Particle Velocity
In this study we intend to present a new strategy to clinical practices that can help researchers in medical and correlated areas to evaluate the effectiveness of new treatments which has been tested in animal models. Furthermore, we also present a discussion about the economic viability of applying these alternative procedures in clinical laboratories.
Topics: XRF, Whole Blood, Clinical Practices, Animal Models
 We study the survival probability of charmonium states in a strongly-interacting quark–gluon plasma with the dissociation temperatures obtained by correcting the full cornell potential not its Coulomb part alone with a dielectric function encoding the effects of deconfined medium. Our results show nice agreement with the experimental results at RHIC.
Topics: Debye Mass, Medium-Modified, Heavy Quark Potential, Dissociation Temperature
A model to estimate the tensile properties of carbon fiber-reinforced polymers (CFRP) based on their moisture contents and molecular structures is formulated and studied. In the proposed model, water molecules absorbed by polymers are considered congregated near the sub-micro-cavities within the polymers. The absorbed water molecules form hydrogen bonds with the polymer molecules and cause the regions around the sub-micro-cavities to have a reduced elastic modulus. The additive group...
Topics: Mechanical Properties, Carbon Fiber-Reinforced Polymer Composites, Epoxy, Moisture
This study describes a reactive process to transfer an electrical conductive polycarbonate (PC) film onto the surface of bulk polycarbonate by an injection molding process using hyper branched poly (ethylenimine) (PEI). Due to a nucleophilic substitution reaction between the amino groups of the poly (ethylenimine) and the carbonate groups of the PC, a stable covalent crosslinking is established. The resulting conductive layer has an average thickness of about 3 -7 µm and a surface roughness...
Topics: Injection Molding, Carbon Nanotubes, Surface Functionalization, Polymer Matrix Composites (Pmcs),...
 The physical foaming agent is dissolved in the polymer at a pressure and temperature beyond its critical condition and the foam structure is formed by a sudden pressure drop or a temperature increase in the mixture in three steps; nucleation, growth and coalescence. In the nucleation step, due to a supersaturation, thermodynamic unstability is formed in the mixture. This induces a tendency in the solvent molecules for a phase transition from a supersaturated state to a gas state in the...
Topics: Thermoplastic Foam, Nucleation, Classical Nucleation Theory, Phase Transitio
Cutting mechanism of drilling CFRP laminates and effects of ultrasonic torsional mode vibration cutting are investigated. CFRP laminates are made of carbon fiber reinforced/epoxy-resin matrix composite ply. Challenges in drilling CFRP laminates arise because of anisotropy due to carbon fiber orientation and heterogeneousness between carbon fiber and epoxy-resin. Experimental works are performed to characterize major hole quality parameters and cutting mechanism encountered when conventional...
Topics: CFRP Laminates, Drilling, Cutting Mechanism, Anisotropy, Heterogeneousness, Hole Quality,...
 A synergistic flame-retardant compound containing magnesium hydroxide (MH) and melamine cyanurate (MCA) ingredients was prepared with ethylene-propylene-diene monomer (EPDM) composite to find a highly efficient, halogen-free, and phosphorus-free flame retardant. The flame-retardant MH/MCA compound particles were modified by a silane coupling agent to increase surface activity. Two series of EPDM/MH/MCA composites were prepared by direct blending methods. The mechanical and flame-retardant...
Topics: Additives, Elastomers, Flame Retardance, Blending, Rubber
Plastic waste management faces severe challenges and opportunities worldwide, regardless of their sustainability awareness and technological advances. In this paper, a better framework for plastic waste management and close loop recycling is proposed. A special emphasis is paid on functional analysis of recycling and utility of a cross functional team for plastic waste management. Paper also focuses on investigating the behaviour of stakeholders and factors that influence the techniques and...
Topics: Plastic waste, Framework, Close loop Recycling, Fast Approach
EMI is necessary to protect electronic equipment from extraneous EM fields and to provide a controlled emission free environment for reliable functioning of electronic equipment. In this paper, the specific roles of reflection and absorption in determining the total shielding efficiency of three layer electromagnetic shielding, as a function of the frequency and the thickness of each layer is discussed. In particular, the reflection, the absorption and the shielding effectiveness of...
Topics: Multi-layer Structure, Electromagnetic Shielding, Reflection, Absorption, Shielding Efficiency
Enhancement of abrasion resistance of phenol formaldehyde based composite brake pad material with various constituents viz. abrasive, filler and binder have been synergistically investigated in the present study. The influence of applied load and abrading distance on three-body abrasive wear behaviour of composite brake pad material has been studied using quartz as abrasives. Wear tests were carried out on a dry sand/rubber wheel abrasion tester. The results indicate that the wear volume loss...
Topics: Composite Brake Pad Material, Three-Body Abrasive Wear, Dispersoid Phases, Morphology of Worn...
This paper exploits a new approach for synthesis of carboxymethyl cellulose grafted poly 2-acrylamdoglycolic acid (CMC-g-PAG) superabsorbent copolymer in aqueous solution by a simple one-step using γ-radiation as a crosslinking agent. The reaction parameters affecting the equilibrium swelling, i.e., mass ratio of AG to CMC and irradiation dose were systematically optimized to achieve a superabsorbent hydrogel with a maximum swelling capacity. The structure, crystallinity, thermal stability and...
Topics: Graft Copolymer, Carboxymethyl Cellulose, 2-Acrylamidoglycolic Acid, γ-Radiation
The thermal degradation behaviour of 50:50 blends of High density polyethylene (HDPE) and petroleum coke has been investigated using mechanical alloying (milling) at speeds ranging between 100 to 300 rpm and for periods up to 5 hours. Milled specimens were characterised using SEM and x-ray diffraction; their thermal degradation behaviour was investigated using thermo-gravimetric analyser (TGA) for temperatures up to 1200°C. Whereas HDPE specimens showed a tendency towards flattening out and...
Topics: HDPE, Petroleum Coke, Mechanical Alloying
 Three ply and five ply composite laminates of jute/glass-epoxy have been prepared by hand moulding technique. Tensile strength at fracture has been determined experimentally and compared to that of theoretical values. Moisture absorption capacity for both the specimens has been found out by hygrometric principle. Corrosion tests have also been carried out by experimental set up developed in house at a low cost referring to the standard ASTM B117. It has been observed that the deviation for...
Topics: Jute/Glass-Epoxy Laminates, Tensile Strength, Moisture Absorption and Corrosion Tests
In this work, we conducted a study on the extraction of natural polymer and use of natural polymer such as coagulating agent in the process of coagulation/flocculation for water treatment, which was carried out to study the removal of turbidity parameter. The natural polymer was extracted from the plant Moringa oleifera, and the extraction occurred in saline, and saline solutions were employed, so did the monovalent (KCl and NaCl) and divalent (BaCl2, CaCl2 and MgCl2). Therefore, given that the...
Topics: Polymer Natural Moringa Oleifera, Coagulation/Flocculation
Unidirectional carbon fibres/epoxy resin composites gamma rays irradiated to doses from 4.8 to 27.2 MGy. Before and after irradiations and annealing at 180 and 250°C, the coupons are tested in the nanoindentation and delamination toughness tests. By nano indentation testing, the hardness and modulus of composite’s phases have obtained. The priority aim was to establish and explain irradiation and annealing effects on hardness and modulus of composites phases; as well to emphasize the...
Topics: Nanoindentation, Hardness, Young Modulus, Mode I Tensile Tests, Strain Energy Release Rate,...
 In order to minimize the environmental pollution due to littered plastic packaging polypropylene (PP) films, the photodegradation of PP films was carried out under natural weathering conditions using ferric carboxylates as prodegradants. Since sunlight (energy source for the photodegradation) is abundantly available, photo-degradation has been chosen one among the various degradation technologies. The photodegradation was followed using the simplest analytical techniques like Fourier...
Topics: Polypropylene, Ferric carboxylates, Natural weathering, FTIR, SEM
Modern society has made the water unfit for consumption by pollution. To comply with quality standards, the water passes through treatment chemicals are applied Which Which allow the removal of turbidity and bodies deleterious to health. These coagulant chemicals and related products, although efficient, physical and chemical characteristics Affect of water, complicate the disposal of sludge generated, and make the water has a high cost, Which is passed on to Consumers. In view of the...
Topics: Water Clarification, Polyelectrolytes, Natural Sources
Thermal conductivity is an important thermal property of materials and plays an important role in determining their heat conduction/insulation capability. The present work aims to study the effect of embedded solid glass microspheres (SGM) on the effective thermal conductivity of epoxy resin. Composite samples were prepared by embedding SGMs of different sizes in the epoxy resin. Three-dimensional spheres-in-cube lattice array models were constructed using finite element method (FEM) to...
Topics: Composites, Glass Microspheres, Thermal Conductivity, Insulation
The effect of vacuum carbonization of waste maize stalk on the thermal resistance of polyester/maize stalk particulate composites has been carried out. Maize stalk were carbonized at a temperature of 1200oC to convert the biomass into biocarbon. The carbonized maize stalk was used to reinforce polyester while the uncarbonized ones served as the control. The carbonized maize stalk particulates (CMSp) were added in different volume fractions into a polyester matrix at an interval of 2, 4, 6, 8,...
Topics: Carbonized Maize Stalk Particulates, Polyester Resin, Thermal Resistance, Thermal Degradation
Folkscanomy: General Academic Papers
Aug 31, 2016
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Homogeneous and crack-free with micron pores organic-inorganic composite monoliths in a binary system of Ca and Si, were prepared by means of a sol-gel route starting from polymerized vinyltrimethoxysilane, about 20-mers, and an alcoholic solutions of calcium acetate. The surfaces of the specimens were characterized using XRD, FT-IR, SEM and EDX analysis. In vitro bioactivity tests were performed in SBF. The in vitro studies showed that all composite monoliths produced were bioactive. These...
Topics: Organic-Inorganic Composite, Monolith, Sol-Gel Process, Bioactivity
Agricultural feed stocks are one of the readily available and inexpensive lignocellulosic feed stocks for preparing cellulose nano fibrils. The very common method for isolation and separation of cellulosic fibrils from these feed stocks include successive physicochemical techniques. In this paper, a mild chemical treatment was used to remove pectinic substances and lignin, following a mechanical defibrillation using a commercial grinder to isolate nano fibres from agricultural fibres such as...
Topics: Bio fibres, Cellulose Nanofibrils, Nanocomposites, Agro- fibres
The degradability properties of cross linked chitosan (ODAC) filled chitosan bio-composites were investigated under swelling analysis. The swelling analysis was performed under the pH medium of 2 to 12, and recorded as swelling ratio (Qt) and swelling rate (Qr). The optimum Qt and Qr values of the bio-composites occurred at pH 7. The Qt and Qr values reduced linearly with the ODAC filler content up to 8 wt/v %. The Fourier Transform Infra-Red (FTIR) analysis of the bio-composites confirms a...
Topics: Biopolymers, Composites, Cross Linking, Compatibility, Degradability
Polymeric films of pure poly (vinyl pyrrolidone) (PVP) and PVP/gelatin blend (60/40) containing various amounts of MgCl2 were prepared using a casting technique. The structural and related physical properties of the prepared films were studied using different techniques. The obtained data revealed that the addition of gelatin and magnesium chloride causes structural variation in the PVP network. The X-Ray diffraction (XRD) patterns reveal that the amorphous nature of the blend increases with...
Topics: Blends, XRD, FT-IR, DSC, Optical, Electrical Properties
 Al- Based metal matrix composites used for automobile brake pad applications are fabricated through P/M route using ‘Preform powder forging’ technology. Dry sliding wear behavior of Al-MMC based brake pads against cast iron disc is studied as per ECR R-90 regulation on Krauss machine tribo-tester. It was observed that the Al- based brake pads posses lower wear rate, same order of Coefficient of friction as in resin bonded brake pads, while the temperature rise is one third as compared...
Topics: Al-MMC, Automobile Brake Pad, Resin-Bonded Brake Pads, Dry Sliding Wear, Krauss Machine Tribo-tester
Recently, wearable devices on human activity sensing have become increasingly popular.In this paper, we propose a new method for walking and running speed estimation. A wearable device based on a tri-axial accelerometer is fixed on the chest to record the acceleration data of human body. Using the acceleration data, we design a fuzzy inference system (FIS) to determine whether the subject is motionless or locomotor. If the subject is walking or running, artificial neural networks (ANNs) are...
Topics: Tri-axial Accelerometer, Fuzzy Inference System, Artificial Neural Network, Speed Estimation
Folkscanomy: General Academic Papers
Aug 31, 2016
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 A clustering protocol based on evolutionary algorithm for Wireless Sensor Networks is proposed. The difference between total energy consumption and single node energy consumption is taken into account while designing the clustering protocol, which can guarantee relatively better tradeoff between the lifetime and the stability period of the network. Finally, the simulation results show that the proposed protocol is much more efficient compared with LEACH and EAERP.
Topics: Clustering, Network Lifetime, Wireless Sensor Networks
 Ultraviolet photons of KrF-laser (λ = 248 nm) based on reactive pulsed laser deposition (RPLD) were used for the synthesis of chromium oxides (Cr3-XO3-Y), iron oxides (Fe2O3-X) 2D structures and Fe2O3-X/Cr3-XO3-Y 2D heterostructure with variable stoichiometry, electrical properties and thickness. 2D structures’ depositions were carried out on Si substrate at its temperature change in the range of 293-800 K. XRD analysis showed the evidence of these structures deposited on substrate had...
Topics: Laser Deposition, 2D Structures, 2D Heterostructures, Oxides, Thermo Sensors
In this work, I propose two new equations which provide very useful information on how they are structured photons. These equations tells us that the photon behaves like a true capacitor and it informs us as well that the energy of a photon is a function of its voltage, its electric field, its magnetic field, the module Poynting, photon volume, the frequency and its wavelength. In this equation, it also presents the electrical charge unitary, the radius of photon and the radius of its core....
Topics: hotonics, Microsystems, Black Body, Laser, Physics, Accelerated Particles, Nanotechnologies, Light,...
In this work we demonstrate that photons, contrary to what is believed, have a mass directly proportional to their frequency. This mass is justified by the combination of 32 constants of physics that I have managed to achieve. The attribution of a mass to the photon is descended from equations, which validates and also demonstrates that it is necessary to define physical concepts such as force and momentum and can justify the increase in mass which is suffered by the particles that are...
Topics: Photonic, Microsystems, Black Body, Laser, Physics, Accelerated Particles
 In this work we demonstrate how the deployment of several types of agents increases the efficiency and the overall success concerning the task to explore unknown terrain, and finding a pathbetween a starting point and various points of interest. The used agents have different capabilities that are typically foundin technical assistance systems used in search and rescueoperations. In our test cases, the environments to be explored have both, regular characteristics like a maze or a building as...
Topics: Search and Rescue, Multi-Agent Systems, Ant Algorithms
In this research we have demonstrated Kalman Filter (KF) that improves the quality of the measurement of sensor signal. Kalman Filter has long been used to eliminate the process error and measurement noise. Bearing in mind that almost all industrial automation and control systems are stock with process errors and measurement noises, we tried to implement Kalman Filtering algorithm to typical processes that measure the height of the water level of a tank and the angle of deviation of the wheel...
Topics: Kalman Filter, Noise, Error, Estimation, Liner Model, Sensor, Mobile Robot, Water Level Measurement
Folkscanomy: General Academic Papers
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A technique for imaging distribution of chest's surface vibration due to heartbeat has been established. This technique is based on measurement of minute vibration of the chest surface using 64 sensors and image processing unit. Relations of the vibrational distribution and the heart motion were discussed. The results showed that vibration of the chest surface included three or four frequency bands; less than 50 Hz, 150-200 Hz, 500-600 Hz, and 700-800 Hz. Clear contour images of the heart were...
Topics: A technique for imaging distribution of chest's surface vibration due to heartbeat has been...
In this article a mathematical model of an immobilized oxidase enzyme electrode is presented. The model is based on the three reaction-diffusion equations containing a non-linear reaction term under the steady state conditions. A simple analytical expressions pertaining to concentrations of the immobilization of three enzyme substrates are obtained by using the new Homotopy perturbation method (HPM). A simple analytical expression of the concentrations of substrate, oxygen and oxidized mediator...
Topics: In this article a mathematical model of an immobilized oxidase enzyme electrode is presented. The...
Improvements on sensitivity resolution of Polarization Maintaining optical fibre sensor based on evanescent field interaction have been achieved by image processing and tracking of transversally immersed polarization maintaining optical fibre probe on HF acid. Etching rates of fibre dopants are tracked in real time and injected in an algorithm for real time simulation of the Polarization Maintaining optical fibre sensor. Resolution sensitivity better than 0.2 dB has been achieved, allowing a...
Topics: Sensors, Fibre, Evanescent Field, Polarization, Image Processing
Folkscanomy: General Academic Papers
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pH sensor on AlGaN/GaN heterostructure with high aluminum mole fraction of 35% was developed. Evaluation demonstrated that transistor-like current-voltage characteristics with good pinch-off performance was confirmed in phthalate, phosphate and tetraborate standard buffer solutions. Decreasing on drain current and positive shift on threshold voltage were found with the pH value increasing. Sensitivity of about 57.7 mV/pH was obtained.
Topics: pH Sensor, Gallium Nitride, AlGaN/GaN Heterostructure
Alongside well-known negative effects on everyday school life, cell phones can be used to enhance physics instruction in many ways: for example, to document and analyze experiments using the camera, to exchange data using various interfaces, to carry out Internet research or to use the cell phone as a measurement and experiment tool. This article focuses on the latter property and makes suggestions as to how the acceleration sensors integrated in smartphones can be used to conduct quantitative...
Topics: Smartphone Physics, Experimental Tools, Acceleration Sensor
The contribution provides an overview of possible experiments with mobile phones in physics lessons. The focus of the article is therefore on the “mobile phone” as an experiment tool. Besides the use of mobile phones for documentation, experiments with mobile phones for analysing gravity acceleration and diffraction phenomena of infrared remote controls as well as experiments of the topic acoustics are discussed. This paper includes relevant examples of the project “N.E.T.–New Media...
Topics: Mobile Phone Applications, Physics Education, Experimental Tools, Material-Aided Situated Learning...
A new technique and circuit topology is proposed to read the output of a capacitive sensor for lab-on-chip (LOC) applications. Through capacitance-to-time conversion, together with several digital blocks, a first-order sigma-delta interface is developed. By encoding the change in capacitance as the difference in time between the rising edges of two digital signals, a compact, low-power realization is achieved. Moreover, the design is tunable along three axes: power, resolution and range. A...
Topics: Capacitive Sensors, Interface, Digital, Low-power, Calibration
A Wireless Mesh Network (WMN) consists of a three tier network that provides access to the internet consisting of clients and routers. The range of router is greater than that of the client in the Wireless Mesh Network. This causes link asymmetry, and leads to degradation in network performance. The link asymmetry causes three main problems, Unidirectional Link problem, Heterogeneous Hidden Terminal problem and Heterogeneous Exposed Terminal Problem. Cross-layer design is a promising method to...
Topics: WM, Cross-layer Design, Carrier Sense
A new Manganese (II) PVC membrane sensor incorporating 2,8,14,20-tetrakis(naphthyl)calix[4]resorcinarene (TNCR) as ionophore, tetraphenylborate (NaTPB) as anion excluder and dioctylphthalate (DOP) as plasticizer was constructed. The electrode exhibited an excellent potentiometric response over a wide concentration range of 1.0 × 10-5 - 1.0 × 10-1 M with a Nernstian slope of 29.8 (± 0.4) mV decade-1. The detection limit was 5.1 × 10-6 M. The electrode showed a better performance over a pH...
Topics: Calix[4]resorcinarene, Manganese (II), PVC Membrane, Potentiometry, Ion Selective Electrode
Folkscanomy: General Academic Papers
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The principle of operation, design aspects, experimentation and performance of a polymer fibre optic probe for sensing micro displacement are discussed. The device is based upon the phenomenon of reflective concept. The sensor can work in either the positive slope region or the negative slope region, in addition, it is capable to measure displacement ranging from 0.1 to 0.8 mm with sensitivity of 2.619 V/mm in the positive slope region and 1.3 to 2.9 mm in the negative slope region with a...
Topics: Displacement Sensor, Fibre Optic Probe, Polymer Optical Fibre
 The task under investigation is determination of disposition of emission source according to the temporal delays of the signals accepted in the network of sensors diversity. The criterion of efficiency for optimization of placing of sensors and the standard examples of network configuration are worked out.
Topics: Passive Location, Sensor Network, Ambiguity, Determination of Coordinates
Electrical resistance measurements on different rod materials in liquid solutions, molten salts, or molten lead are considered to design a liquid level sensor in a sealed containers when the temperature of the fluid is very high (~1000ºC) and conventional measurements are not possible due to properties of the fluid or condition of the container. An analytical solution to the problem is adopted to reduce the cost of the sensor and overcome the difficulties of calibration of sensors at high...
Topics: Analytical Solution, Electrical Circuit Mode, Confined Container, High Temperature Liquid, Liquid...
The aim of this work is to describe the physics-based simulation model of a custom 3D range laser scanner together with generic interface which offers the possibility for client applications to seamlessly interact with instances of the physical and virtual 3D range scanner. The physics-based virtual model of the 3D range scanner is realized in rigid body dynamics environment provided by Open Dynamics Engine (ODE) library. In order to simulate the stepper motor used in the real scanner, the...
Topics: Modeling, Simulation, 3D Range Scanner, Rigid Body Dynamics, Ray-cast Method
 The aim of this work is to describe the physics-based simulation model of a custom 3D range laser scanner together with generic interface which offers the possibility for client applications to seamlessly interact with instances of the physical and virtual 3D range scanner. The physics-based virtual model of the 3D range scanner is realized in rigid body dynamics environment provided by Open Dynamics Engine (ODE) library. In order to simulate the stepper motor used in the real scanner, the...
Topics: Modeling, Simulation, 3D Range Scanner, Rigid Body Dynamics, Ray-cast Method
The task under investigation is determination of disposition of emission source according to the temporal delays of the signals accepted in the network of sensors diversity. The criterion of efficiency for optimization of placing of sensors and the standard examples of network configuration are worked out.
Topics: Passive Location, Sensor Network, Ambiguity, Determination of Coordinates
 This paper proposes a method of surface electromyography (sEMG)-based mensuration of muscle fatigue during elbow flexion-extension. The proposed method has two parts. First, the joint angle and locations of body segments are estimated using inertial measurement units (IMU) and the OpenSim biomechanics simulator. Second, muscle fatigue is measured using OpenSim and a three-compartment muscle fatigue model. The experimental results show that muscle fatigue increases in accordance with the...
Topics: Muscle Fatigue, EMG, IMU, Biomechanics, Opensim, Motion Capture, Elbow Flexion-Extension
The cutting tool of cutting-off sugarcane-leaf returning machine was nonmetal material and rotated at high speed during working in field. The flexible cutting tool had large deformation when it stroked the ground. According the working condition of the cutter, the study researched the fatigue properties of the nonmetal cutting tool. In order to obtain the fatigue load spectrum of the stress, the ground stroking process of the rotary cutting tool was analyzed by Finite Element Method (FEM)...
Topics: Sugarcane Leaf, Returning Machine, Large Deformation, Fatigue Property, Finite Element Method
 An investigation of soil contamination is a very important issue in soil environmental studies. It leads to classification of all living organisms in the soil, as well as essential materials and particles that these organisms use to survive which together form the soil ecosystem. It is vital to study the soil ecosystem to understand interface and relationship of organisms existing in the soil and their impact to environment surrounding them. Soil environmental study attracts an interest of...
Topics: Geotechnical Investigations, Environment, Tests, Remote Sensing and GIS
Folkscanomy: General Academic Papers
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A test system was introduced in this article for infrared detector and pre-amplifier based on virtual instrument technology; in which an industrial PC was utilized as main control platform, and a self-design image data acquisition and processing board, a self-design channels switch control board and some general equipments were included. Using the virtual instrument software LabVIEW 2011, the system can achieve two infrared detectors and pre-amplifiers in high/low/normal temperature test....
Topics: Infrared Detector, Pre-amplifier, Blind Pixel, 3σ Principle, Test System
Aiming at reducing weight of equipment, saving material and increasing lifting capability of crane, variable stiffness structure is designed in project. Ccumbersome calculation has increased the design difficulty of variable stiffness structural. For large slenderness ratio telescopic jib structure, the existing calculation methods simplify self weight as concentrated load and assume obeying small deformation criterion. For flexural deformation, the effect of self weight different distribution...
Topics: Variable Stiffness, Large Slenderness Ratio, Telescopic Jib, Gravity Effect, FEM, Large-deformation
Aiming at large deformation, geometric, contact, material nonlinear and coupling for the structure of hectometer level elevating fire truck jib, limit state method is first adopted to design. In order to take into full consideration the impact of all kinds of load deviation value and discontinuity of materials from working grades classification, load states, load combination, material resistance and high risk coefficient to 3S (Strength, Stiffness, Stability) bearing capacity, load combination...
Topics: Elevating Platform Fire Truck, Jib Structure, Limit State Method, Geometric, Contact and Material...
Folkscanomy: General Academic Papers
Aug 30, 2016
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The distribution of stresses of the welded pipe-plate joints is complicated. To study the strength of the joints, the parameter analyses were undertaken using nonlinear finite element method and uniform design approach. The pipe diameter, thickness, the plate width, height, and thickness were considered. Three kinds of loading conditions on the plate-the axial force, the moment, the combined axial force and moment were analyzed. The strength formulas of the joints are proposed by regression...
Topics: Strength, Welded Pipe-plate Joint, Parameter Analyses, Uniform Design
 This paper develops a G-code programming tool for a SCARA robot with four degrees of freedom, which is easily operated by users. At first, in order to establish a connection between the G-codes which are entered by users and specified actions of the robot, a decoding protocol is formulated. Then, a communication protocol is planned for upper computer sending the decoding files to lower controller through a serial port to drive the robot. The protocols are applied to decode modules and...
Topics: G-code, Decoding, Serial Port, Robot
Folkscanomy: General Academic Papers
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 The efficiency of overhead traveling crane transportation is limited by payload swing induced by velocity change of the crane. To obtain high efficiency, this study introduced an ideal trajectory for crane’s speed trajectory tracking controller. Pontryagin’s maximum principle was used to develop an optimal trajectory to minimize the swing angle of payload based on the kinematic model of overhead traveling crane with constant hoist rope length. A simplified trajectory which is more...
Topics: Optimal Control, Ideal Trajectory, Anti-swing Control, Overhead Traveling Crane
This study conveys the results of long stroke ball screw vibrations that were studied using a nonlinear finite element method. Because the nut in the experiment moved both forward and backward, a formulation that incorporated an updated Lagrangian method was employed to examine large displacement in the lateral directions. When the nut changed position, one of the screw segments became longer and its natural frequencies decreased, resulting in the formation of high-to-low frequency curves....
Topics: Ball Screw, Nonlinear Finite Element Method, Vibration Ripple Patterns
The external layer in a building has a paramount role under the building’s energy behaviour point of view. The ventilated façade is a passive system installed on buildings to improve the global energy behaviour. The ventilated façade performance is described. Ventilated façade is mainly based on convection and radiation. This contribution focuses on the convective effect due to buoyancy driven respect to wind forces in the ventilated gap and their influence on the building thermal...
Topics: Convection, Natural Ventilation (NV), Ventilated Façade (VF), Computational Fluid Dynamics (CFD)
In this work, a methodology for analysis of the performance of wire meshes as regenerative media for Stirling engines is proposed. Methodology includes operation conditions of the engine and mesh physical characteristics, such as material and porosity, as parameters to predict the pressure drop and the thermal efficiency of the mesh. The proposed methodology was used to evaluate regenerators made of stainless steel wire meshes of 100, 150 and 250 threads per inch, of three different Stirling...
Topics: Stirling Engine, Regenerator, Pressure Drop, Thermal Efficiency, Wire Meshes
The behaviour of magnetohydrodynamic (MHD) natural convection flow from a porous vertical plate is studied with respect to variable viscosity. To model the flow, the governing boundary layer equations are first transformed into a non dimensional form. The resulting non linear system of partial differential equations is then solved numerically using finite difference method together with Keller-Box scheme. The study shows that the variation of viscosity influences the surface shear stress (skin...
Topics: Porous Plate, Magnetohydrodynamic, Natural Convection, Variable Viscosity
 Radiological makers for artificial implants have increased in number/ varieties/ applications during recent years. Lumbar Artificial Disk Technology uses frequently these markers to optimize the biomechanical positioning of the artificial implant, both during the setting-in at operation theatre, and along post-surgery period. These markers are practical to control the disk position/geometry and avoid post-surgical mechanical complications. In addition, geometrical/ algorithmic information...
Topics: Radiological Contrast (RC), Kilovoltage, Polymeric Material, Tantalum, Tungsten, C-Arm RX Machine,...