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Analysis of Radial vibrations in a two layered poroelastic hollow cylinder loaded and surrounded by inviscid fluids is presented. A poroelastic composite hollow cylinder consists of two concentric cylindrical shells with each one made with different poroelastic materials. The poroelastic materials are assumed as homogeneous and isotropic, whereas the inner and outer fluids are homogeneous, isotropic and inviscid. The frequency equation of Radial vibrations of two layered poroelastic cylindrical shell is derived. The effect of inviscid fluid on Radial vibrations is observed. The frequency equation of fluid-loaded poroelastic composite cylinder surrounded by a fluid is obtained along with several particular cases, namely, fluid-loaded poroelastic composite cylinder, fluid-loaded composite bore, poroelastic composite cylinder surrounded by fluid. Non-dimensional frequency is computed as a function of ratio of thickness to inner radius of core cylinder then discussed. The results are presented graphically for two types of poroelastic composite cylinders and then discussed.

This article presents the microwave imaging techniques in order to detect early lung cancer with dielectric properties of normal and cancerous tissues which affect the propagation of the microwave signal. Identifying the contrast of dielectric properties of normal and cancerous lung tissues is significant in microwave imaging because it is used in reconstructing the image either in radar-based or tomographic imaging techniques. In microwave imaging measurement from past researchers are highlighted in order to identify the optimum distance of the antenna from the human thorax and the significant size of the tumour that can be detectable.

The numerical analysis of thermal damage process proceeding in biological tissue, containing blood vessel, during laser irradiation is presented. Heat transfer in the tissue is assumed to be transient and two-dimensional with perfusion coefficient dependent on tissue injury. The internal heat source resulting from the laser irradiation based on the solution of diffusion equation is taken into account. At the stage of numerical computations the boundary element method and the finite difference method have been used. In the final part of the paper the results obtained are shown.

In this paper, couple stress fluid flow in a rectangular channel generated due to applied transverse magnetic field. Since the magnetic parameter is very small, the induced magnetic field is neglected. The 4th order PDE for axial velocity w is solved under i) the no slip and ii) hyper stick boundary conditions. The velocity w is obtained in Fourier series. The effects of physical parameters like couple stress parameter and Hartmann number on skin friction and volumetric flow rate are studied through graphs. It is observed that the external magnetic field decreases the skin friction and the volumetric flow rate.

In photoacoustic spectroscopic (PAS) technique, acoustic piston model is considered and the optical properties of solids are studied. One has to detect the photoacoustic (PA) signal produced when a sample placed in a cell is irradiated by an intensity modulated beam of light. The PA signal is used to investigate the optical properties of solids. In this paper we report on the theoretical, experimental issues on the application of photoacoustic spectroscopy for the investigation of optical properties of Cu2GeSe3 compound. Optical-absorption spectra has been obtained in the range of 0.76 -0.81 eV photon-energy at temperatures between 70 and 300 K. The thermal variation of band-gap energy has been estimated from the optical-absorption spectra at different temperatures.

Quantitative ultrasound (QUS) has shown a great potential in the assessment of bone characteristics in the recent research. However, wave propagation in bones is very challenging due to the nature of multi-layer, anisotropic, and viscoelastic behaviors. Therefore, our knowledge of wave interaction with bone structures is far from complete and the resulting wave modes have not been fully explained. The aim of the current study is to develop a model for propagation of ultrasonic guided waves in a soft-tissue layer over a cortical bone layer. The amplitudes of wave modes generated by time- harmonic loads in the bilayered plate are theoretically computed by reciprocity consideration.

Medical ultrasound imaging provides images of interior of the body for diagnosis. Speckle noise is a major problem degrading image quality. In this paper a wide class of noise reduction models is considered from the group analysis point of view. Group classification is performed and conservation laws of the equation studied in cylindrical coordinates are presented.

Silver nanoparticles were prepared in polymeric solution of ethanol by laser ablation method. The effect of these nanoparticles on the linear and nonlinear optical properties of neutral red dye has been studied. Single beam Z-scan technique was used for the nonlinear characterization of the samples. The nonlinear optical properties of neutral red dye enhanced significantly in the presence of silver nanoparticles and the reasoning is given on the basis of increased local field effects of nanoparticles.Silver nanoparticles were prepared in polymeric solution of ethanol by laser ablation method. The effect of these nanoparticles on the linear and nonlinear optical properties of neutral red dye has been studied. Single beam Z-scan technique was used for the nonlinear characterization of the samples. The nonlinear optical properties of neutral red dye enhanced significantly in the presence of silver nanoparticles and the reasoning is given on the basis of increased local field effects of nanoparticles.

Magnetic resonance imaging(MRI) is a technique used to form images of anatomical and physiological processes. On the other hand, MRI images by the diffusion tensor are based on measurements of the diffusion water along different directions, these measurements allow to calculate the diffusion tensor. Apparent diffusion coefficient (ADC) is a measure of the magnitude of diffusion of water molecules within a tissue. Fractional anisotropy (FA) shows the direction of the diffusion. In this way, from a sample of 34 patients, the values of the fractional anisotropy and the diffusion apparent coefficient were obtained, from the areas classically associated with language, with the goal to future studies will allow to document and standardize his values in the developing pediatric brain and to detect abnormalities in patients with specific language disorders.

The nonlinear optical (NLO) properties of nematic liquid crystal (LC)N-(4-methoxybenzylidene)-4-n-butylaniline (MBBA)doped with various concentrations of multi walled carbon nanotubes (MWCNTs) have been investigated utilizing Z- scan technique. The obtained results showed that the NLO properties of MBBA LC sample can be varied by changing the concentration of CNTs. A small concentration of carbon nanotubes (CNTs) can be enhanced optical nonlinearity, and the maximum nonlinearity was noticed at the sample doped with 0.1 wt% concentration of CNTs.

A novel approach to acoustic collimated beam generation is discussed. It relies on the radial modes of vibration of piezoelectric discs. Ultrasonic beam generation from these radial modes is investigated using numerical simulations and experiments. A free piezo-disc generates Bessel beams that possess a well-collimated central lobe and significant side- lobes. Clamping the lateral edge of the disc was shown to drastically reduce the side-lobes, generating a highly collimated acoustic beam. This technique has a wide variety of low-frequency ultrasonic applications as in borehole integrity monitoring, particle manipulation and acousto-optics.

The present study is devoted to the computational problem of the residual stresses inside human blood vessel wall during atherosclerosis. The blood vessel (artery) wall is simulated by the thick-walled very long circular cylinder. The governing and constitutive equations of mechanics of surface growth solids are reminded for thick-walled solid case. The boundary value problem of the surface growth of an elastic thick-walled vessels is stated, solved and analyzed. The analytical solution is obtained in terms of velocities of stress strain state parameters. The condition of thickness allows us to study finite displacements of cylinder surfaces by means of infinitesimal deformations. The residual stresses caused by the influence of internal pressure are computed according to various initial growth tension in the adding layer.

In this research, a non-Newtonian model for blood flow within a stenosed artery is investigated numerically. Finite Element Method of Galerkin’s weighted residual scheme is used to solve the transport equations with appropriate boundary conditions. The main objective of this study is to explore the influence of magnetic field on the blood flow. The numerical results are presented in terms of the velocity, pressure distribution and shear rate of the stenosed artery.

This paper presents numerical investigation results of airflow through a square duct with an installed tripping rod. A square section duct with a hydraulic diameter of 125 mm was built for this study. This duct consists of straight duct at upstream and downstream also square elbow 90° with curvature ratio (R/Dh=3). Tripping rod is installed on a square elbow (90°) with three variations on shapes. These shapes are circular cylinder, square cylinder, and oriented square cylinder, respectively. All tripping rod has a constant dimension based on circular cylinder diameter. Tripping rods are located near the inner wall of a square elbow with a constant gap ratio of (g/d) 0.2. The turbulent viscous models are used to simulate with a k-epsilon standard with enhanced wall treatment. All simulations are modeled for Re 1.59 × 104 based on the hydraulic diameter of the duct. The numerical simulation result is consists of turbulent intensity and pressure drop. There is a reduction of downstream pressure drop based on the result if the circular cylinder used as the comparison point, as follows oriented square cylinder has 2.23 % reduction. square cylinder has 1.74 % reduction at downstream at 8°.This paper presents numerical investigation results of airflow through a square duct with an installed tripping rod. A square section duct with a hydraulic diameter of 125 mm was built for this study. This duct consists of straight duct at upstream and downstream also square elbow 90° with curvature ratio (R/Dh=3). Tripping rod is installed on a square elbow (90°) with three variations on shapes. These shapes are circular cylinder, square cylinder, and oriented square cylinder, respectively. All tripping rod has a constant dimension based on circular cylinder diameter. Tripping rods are located near the inner wall of a square elbow with a constant gap ratio of (g/d) 0.2. The turbulent viscous models are used to simulate with a k-epsilon standard with enhanced wall treatment. All simulations are modeled for Re 1.59 × 104 based on the hydraulic diameter of the duct. The numerical simulation result is consists of turbulent intensity and pressure drop. There is a reduction of downstream pressure drop based on...

Refractive indices, extinction coefficients and dielectric properties of B+ implanted polyethylene terephthalate (PET) have been measured for the mid-infrared wavelength region. PET specimens were implanted with 50 keV boron ions in the fluence range of 1×1015- 5×1016 ions cm−2. The change in refractive index and extinction coefficient values due to ion implantation has been studied by specular reflectance Fourier transform infrared spectroscopic technique. Using refractive index and extinction coefficient values dielectric constant has also been find out in THz frequency region. Furthermore, structural modification in ion implanted matrix has been observed by FTIR transmission spectra. The intensity of characteristics bands observed in FTIR spectra of implanted specimens show a remarkable decline compared to virgin specimen pointing towards structural rearrangements. The possible correlation between the changes observed in optical constant values and structural modification have been discussed. The modified ion implanted PET polymer allows fabrication of optical waveguides and filters etc. in IR range of wavelength.

International audience; Nanoparticles are grown in a capacitively-coupled radio-frequency discharge (ccrf) in argon from the sputtering of a carbonaceous film deposited on the electrodes. This brown film was previously formed from the ethanol decomposition obtained in argon/ethanol plasmas. During the nanoparticle growth, optical emission spectroscopy reveals the evolution of some typical carbonaceous molecules. The nanoparticle formation also disturbs the plasma equilibrium and induces several plasma instabilities consisting in some cases in regular plasma rotation at very low frequencies. Once nanoparticles are large enough to be observed, they constitute a dense cloud trapped in between the electrode with one central or two symmetrical voids. Ex-situ analysis by scanning electron microscopy evidences that grown nanoparticles can have original surface stuctures.

In this work pure and Ni-doped ZnO nanoparticles have been prepared by sol-gel method. Influence of nickel doping on structural, morphological and magnetic properties of prepared nanoparticles was investigated by X-ray diffraction technique (XRD), Scanning electron microscopy (SEM) and Pulse field magnetic hysteresis loop. X-ray diffraction pattern shows the formation of a single phase with hexagonal wurtzite structure of both pure and Ni-doped ZnO nanoparticles. The lattice parameters ‘an’ and ‘c’ of Ni-doped ZnO is slightly less than that of pure ZnO nanoparticles. The crystalline size of prepared nanoparticles is found to be in 29 and 31 nm range. SEM technique used to examine the surface morphology of samples, SEM image confirms the nanocrystalline nature of present samples. From the pulse field hysteresis loop technique pure and Ni-doped ZnO nanoparticles show diamagnetic and ferromagnetic behavior at room temperature respectively.

The article presents the mathematical modeling of the phenomenon of artificial hyperthermia which is caused by the interaction of an electric field. The electric field is induced by the applicator positioned within the biological tissue with cancer. In addition, in order to estimate the degree of tumor destruction under the influence of high temperature an Arrhenius integral has been used. The distribution of electric potential in the domain considered is described by the Laplace system of equations, while the temperature field is described by the Pennes system of equations. These problems are coupled by source function being the additional component in the Pennes equation and resulting from the electric field action. The boundary element method is applied to solve the coupled problem connected with the heating of biological tissues.

This study presents the results of Monte Carlo simulations to obtain stopping power of protons in energy ranges and materials of therapeutic importance. The source was modeled as a point source emitting mono-energetic pencil beam of protons. A cylinder containing the material of interest was placed in vacuum to represent the phantom, a cylinder of 30 cm radius and 100 cm height. A disk-shaped thin detector (r=2 cm) was created in this phantom to compute average values of absorbed dose and flux. Its thickness varied from simulation to simulation depending on the energy of the incoming source protons. Average flux and absorbed dose were computed in the detector cell to evaluate the value of the stopping power for the material of interest at that specific energy. The results obtained in this study are compared with the data from the NIST compilation.

A numerical simulation to investigate the Non-Newtonian modeling effects on physiological flows in a three dimensional idealized stenosed carotid artery with 75% severity (by area) is taken from patient specific model. The wall vessel is considered to be rigid. Oscillatory physiological and parabolic velocity profile has been imposed for inlet boundary condition. Where the physiological waveform was performed using a Fourier series with sixteen harmonics. The investigation has a Reynolds number range of 94 to 1120. Low Reynolds number k − ω model is used as governing equation. The investigation has been carried out to characterize two Non-Newtonian constitutive equations of blood, namely, (i) Carreau and (ii) Cross models. The Newtonian model has been investigated also to study the physics of fluid. The results of Newtonian model are compared with the Non-Newtonian models. The numerical results are presented in terms of pressure, wall shear stress distributions and the streamlines contours. At early systole pressure differences between Newtonian and Non-Newtonian models are observed at pre-stenotic, throat and immediately after throat regions. In the case of wall shear stress, some differences between Newtonian and Non-Newtonian models are observed when the flows are the minimum such as at early systole or diastole. It is known that blood is Bingham plastic fluid. So the viscosity of blood will decrease with increase in shear rate and when shear rate will be greater than 100 then viscosity will be constant. The viscosity of Newtonian model is less than that of non-Newtonian model when shear rate is less than 100, but viscosity of all models is equal when shear rate is equal to 100. When Reynolds number is very low then pressure and WSS of Newtonian model will be less than that of non-Newtonian model but opposite scenario will be seen for velocity distribution. Since early systole and diastole there are comparatively low Reynolds numbers, the results of Newtonian and non-Newtonian condition may be different at early systole and diastole. On the other hand maximum Reynolds number is seen at peak systole. So the results of Newtonian and non Newtonian condition follow each other at peak systole. Again the velocity of the throat region is high for any time instant. So the results of Newtonian and non Newtonian condition may be same at the throat region but different at the pre and post stenotic region. The results of pressure, WSS, and velocity distribution are discussed below with respective figure.

The article presents the study of heat and mass transfer effects on the two-phase model of the blood flow through a stenosed artery. The blood flow is considered as Newtonian fluid in both phases, i.e., the core and the plasma region. The coupled nonlinear differential equations are modeled for momentum, energy and concentration of the blood flow in the central core and plasma regions. Since the study takes care of radiation and magnetic effects on blood flow, major characteristics of the blood flow such as flow resistance, total flow rate and wall shear stress are calculated for different values of magnetic field and radiation parameter. The study reveals that increasing the magnetic field intensity and radiation effect leads to decreased velocity and temperature profiles of the blood flow. It is pointed out here that the concentration of the blood flow in core and plasma regions increases as values of the Schmidt number increase. Streamlines in stenosed, narrowed artery are demonstrated for the case of 20%, 40% and 50% of the arterial blockage.

Biomedical image is generally noisy and little blur due to the physical mechanisms of the acquisition process, so one of the common degradations in biomedical image is their noise and poor contrast. The idea of biomedical image enhancement is to improve the quality of the image for early diagnosis. In this paper we are using Wavelet Transformation to remove the Gaussian noise from biomedical images: Positron Emission Tomography (PET) image and Radiography (Radio) image, in different color spaces (RGB, HSV, YCbCr), and we perform the fusion of the denoised images resulting from the above denoising techniques using add image method. Then some quantive performance metrics such as signal -to -noise ratio (SNR), peak signal-to-noise ratio (PSNR), and Mean Square Error (MSE), etc. are computed. Since this statistical measurement helps in the assessment of fidelity and image quality. The results showed that our approach can be applied of Image types of color spaces for biomedical images.

The microstructural model of Red Blood Cells (RBCs) behavior was proposed. The erythrocyte is treated as elastic object, which is denoted by network of virtual particles connected by elastic springs. The modeled RBC is submerged in plasma modeled by lattice Boltzmann fluid, which allow incorporating fluid – structure interactions. The simulations of RBCs behavior during flow between two parallel plates and wall impact were performed.The microstructural model of Red Blood Cells (RBCs) behavior was proposed. The erythrocyte is treated as elastic object, which is denoted by network of virtual particles connected by elastic springs. The modeled RBC is submerged in plasma modeled by lattice Boltzmann fluid, which allow incorporating fluid – structure interactions. The simulations of RBCs behavior during flow between two parallel plates and wall impact were performed.

Alternating current (ac) susceptibility-based magnetic biosensing techniques in liquids are promising biomedical applications of magnetic nanoparticles because the methods have a potential for realizing the simple wash-free detection of diseases. Controlling magnetic relaxation of nanoparticles is crucial in the biosensing; Brownian relaxation based on the particle rotation in liquids should be dominant to improve the sensitivity. Therefore, we focus on magnetically anisotropic Fe3O4 nanorods because it is considered that the particle rotation dominates magnetic response of suspended Fe3O4 nanorods due to the shape magnetic anisotropy. In the present paper, the Fe3O4 nanorods are fabricated and the dynamic magnetic response of Fe3O4 nanorods is evaluated under the liquid phase and the solid phase.

Here we provide computable approach to percolation, with possible applications to tissue growth modeling.Here we provide computable approach to percolation, with possible applications to tissue growth modeling.

The miniaturization of electronic devices with high processing components is promoting the rapid increase in heat generation of devices/systems. Synthetic jet cooling flexible thin device has major advantages in order to suit the device miniaturization and compactness. Diaphragm motion is the main component in the device that generate fluid motion for cooling application. In this paper, the synthetic jet diaphragm has been characterized using Laser Doppler to record the motion to determine the motion type. Based on the recorded motion, a User Define Function coding has been develop to imitate the motion in Computational Fluid Dynamic (CFD) software in order to simulate the fluid motion based from the actual diaphragm motion. The diaphragm motion showed a dome shape motion as the laser tracking result were plotted at three points across the diaphragm diameter. Results show that the diaphragm has sinusoidal motion which produce maximum amplitude at 500Hz driving frequency. The UDF program for diaphragm motion has been able to mimic the experimental result.The miniaturization of electronic devices with high processing components is promoting the rapid increase in heat generation of devices/systems. Synthetic jet cooling flexible thin device has major advantages in order to suit the device miniaturization and compactness. Diaphragm motion is the main component in the device that generate fluid motion for cooling application. In this paper, the synthetic jet diaphragm has been characterized using Laser Doppler to record the motion to determine the motion type. Based on the recorded motion, a User Define Function coding has been develop to imitate the motion in Computational Fluid Dynamic (CFD) software in order to simulate the fluid motion based from the actual diaphragm motion. The diaphragm motion showed a dome shape motion as the laser tracking result were plotted at three points across the diaphragm diameter. Results show that the diaphragm has sinusoidal motion which produce maximum amplitude at 500Hz driving frequency. The UDF program for diaphragm moti...

Third-order optical nonlinearity of the co-doped CdS nanoparticles embedded in polymer thin films is studied with the Z-scan technique with 632.8 nm excitation using a cw laser. The results show that the co-doped CdS nanocomposite film exhibits enhanced negative nonlinear refractive index in the order of n2 ≈ 10-5 cm2/W, as compared to the undoped CdS nanoparticles. Nonlinear refractive index of co-doped CdS-PVP thin film are found maximum for the sample doped with 5 wt% of Nd3+-Li+ concentration. The underlying mechanism is discussed.

For the specific structure and extraordinary properties, carbon nanotubes (CNTs) have many applications in diversified fields. The interaction of CNTs with ammonia is a very interesting matter to study as it is related to the application of CNTs as ammonia sensor. Here the interaction of single walled zigzag, armchair and chiral carbon nanotubes is studied in respect of the change in energies before and after binding with ammonia by molecular dynamics simulation. Their deformation after simulation is modeled. The change of thermal conductivity of the CNTs is also found by simulation. The potential energy before and after absorption of ammonia gives useful information of the system. Thermal conductivities of the ammonia bound CNTs are changed considerably. It is observed that the potential energy and thermal conductivity both are changing for the interaction with ammonia and hence they are sensitive to ammonia binding.For the specific structure and extraordinary properties, carbon nanotubes (CNTs) have many applications in diversified fields. The interaction of CNTs with ammonia is a very interesting matter to study as it is related to the application of CNTs as ammonia sensor. Here the interaction of single walled zigzag, armchair and chiral carbon nanotubes is studied in respect of the change in energies before and after binding with ammonia by molecular dynamics simulation. Their deformation after simulation is modeled. The change of thermal conductivity of the CNTs is also found by simulation. The potential energy before and after absorption of ammonia gives useful information of the system. Thermal conductivities of the ammonia bound CNTs are changed considerably. It is observed that the potential energy and thermal conductivity both are changing for the interaction with ammonia and hence they are sensitive to ammonia binding.

This paper solves fluid-structure interaction between flexible wall and two types of fluid. Wall was considered as aorta and was described as hyperelastic material by 5-parameters Mooney-Rivlin model. Fluids and structure were set as incompressible. First fluid was Newtonian and has dynamic viscosity of the blood. Second was non-Newtonian and its viscosity was defined with Carreau rheology model. The aim of this paper is to show a comparison between Newtonian and non-Newtonian fluid flow in pliable vessel.

In this research, we are focused on mathematical modeling for blood flows in an elastic artery. We considered the blood as an incompressible inviscid fluid and treated the artery as an incompressible, isotropic and thick elastic tube. The modulation of nonlinear wave modulation wave in thick elastic tube filled with inviscid fluid is studied. By using reductive perturbation method, we obtained the Nonlinear Schrodinger (NLS) type equation as the evolution equation for the corresponding mathematical model.

The investigation of gas pressure variation during its porosity trough fibrous composite material is offered. Rarefied gas pressure diffusion model is used for calculate the gas permeability of fibrous composite material. Simulation results are compared with the crystalline material regular lattice gas permeability, for example quartz.

The numerical analysis of thermal damage process proceeding in biological tissue during laser irradiation is presented. Heat transfer in the tissue is assumed to be transient and two-dimensional. The internal heat source resulting from the laser irradiation based on the solution of diffusion equation is taken into account. The tissue is regarded as a homogeneous domain with perfusion coefficient treated as dependent on tissue injury. At the stage of numerical computations the boundary element method and the finite difference method have been used. In the final part of the paper the results obtained are shown.

Thin films of GdFeO3, orthoferrite have been grown on MgO (001) substrate by pulsed laser deposition technique (PLD) to investigate the effect of swift heavy ion irradiation on their structural and magnetic properties. Thin films were irradiated with 200 MeV Ag15+ ions with fluence of 1×1011ions/cm2. The results of X-ray diffraction, atomic force microscopy and vibrating sample magnetometer characterization techniques are found to be different for the irradiated film from that of the pristine sample. The modifications in the irradiated samples are explained in terms of the ion-induced disorder.

The aim of the present study is to simulate healthy and pathological human bronchial trees. Analytical formulas are derived for constructing an individual bifurcation of a bronchus and the entire bronchial tree with allowance for the deviation of the inner surfaces of the bronchi from a cylindrical shape. All surfaces of the bronchial tree are matched with the second-order smoothness (there are no acute angles or ribs). The geometric characteristics of the bronchial tree and the “starry” shape of the inner structure are defined parametrically.

Characterization of material properties can be performed using a wide array of methods e.g. X-ray diffraction or tensile testing. Each method leads to a limited set of material properties. This paper is interested in using ultrasound tomography to map speed of sound inside a material sample. The velocity inside the sample is directly related to its elastic properties. Recent develop-ments in ultrasound diffraction tomography have enabled velocity mapping of high velocity contrast objects using a combination of bent-ray time-of-flight tomography and diffraction tomography. In this study, ultrasound diffraction tomography was investigated using simulations in human bone phantoms. A finite element model was developed to assess the influence of the frequency, the number of transduction positions and the distance from the sample as well as to adapt the imaging algorithm. The average velocity in both regions of the bone phantoms were within 5% of the true value.

Recently the cold atmospheric plasma jet is applied for wound healing, sterilization and disinfection. Room temperature non-equilibrium atmospheric plasma operates under the threshold of thermal damage to the tissue. The plasma jet formation and propagation characteristics are studied in the experiment and in numerical fluid model simulations.

In-vivo dosimetry for brachytherapy has been investigated since decades with a number of different detectors and measurement technologies. X-ray films, semiconductor detectors, thermo-luminescent dosimeters and ionization chambers are the systems most currently used. However, ionization chambers do not allow point-like dose measurements near the tumor, semiconductor detectors are not water equivalent and are very sensitive to temperature changes, and thermo-luminescent dosimeters do not allow real-time measurements. For these reasons, during the last two decades, there has been an increased interest for scintillation dosimetry using scintillating fibers, due to their most favorable characteristics and dosimetric properties, as water equivalence, response linearity with increasing dose rates, independence from temperature and small size. In the present work, we present experimental studies of key characteristics of the components of a scintillation dosimeter: the light collection in different types of scintillating fibers and the gain as a function of temperature of a silicon photomultiplier (SiPM), for the design and construction of an in-vivo scintillation dosimeter prototype for brachytherapy.

A source of epithermal neutrons based on a vacuum-insulated tandem accelerator and a lithium target was proposed and developed for the technique of boron neutron capture therapy. A stationary proton beam of 2 MeV with a current of up to 6 mA was produced by the accelerator. To optimize the injection of a beam of negative hydrogen ions into the accelerator, a wire scanner OWS-30 (D-Pace, Canada) was installed [1]. The main problem is that using the profilometer in the form in which it was provided does not allow us to determine the main beam parameters such as position and size. Also, the electron emission does not allow measurement of the total beam current and may lead to incorrect measurement of the beam profile. We have modernized the scanner by placing metal rings in front and behind the scanner with a negative potential to suppress the secondary emission of electrons from the scanner wires. We have developed software in which methods for calculating the position and size of the beam, methods for calculating the total current are implemented. Modernization of the scanner has made it possible to expand its capabilities. The suppression of the secondary electron emission made it possible to reconstruct the current profile of the ion beam and determine the value of the total current. The developed program allowed to display the coordinates of the beam, its dimensions and the total current. We are the first who proposed and implemented a new way of measurement of the beam emittance. A movable diaphragm was inserted in front of the wire scanner. Ion beams passing through the aperture of the diaphragm were measured by the wire scanner with а high level of detail when the diaphragm was moved along a radius. The use of a modernized scanner made it possible to detect the effect of space charge and the effect of the spherical aberrations of the focusing magnetic lenses on a beam of negative hydrogen ions. The use of the modernized scanner made it possible to optimize the injection of a beam of negative hydrogen ions into the accelerator, which led to an increase in the proton current and an improvement of the accelerator stability. The modernized scanner with an additional program for processing the results data and visualization has become a reliable device for beam diagnostics and for controlling beam entry into the accelerator.

Prey-predator Interaction Model between herring and harbor seal is introduced in this study. Phocine Distemper Virus (PDV) that attacks the seals and catching the herring were included in the model. The model was built as a system of ordinary differential equations consisting of three-dimensional consist of herring, healthy seals and infected seals populations. The models derived from five equilibrium points among is trivial, equilibrium point without the presence of seals, namely the equilibrium point without the presence of the disease, that is the equilibrium point with the presence of the disease, and that is the equilibrium point coexistence. From the analytical results of the study obtained positive terms and conditions of the stability of each equilibrium. Numerical simulation supports multiple analytic studies also demonstrated in this paper.

We have experimentally measured the optical properties of Ag nanoparticle-CdTe quantum dot hybrid system and compared it with that of bare CdTe quantum dot colloid. It has been shown that the photoluminescence line shape of CdTe quantum dots becomes asymmetric in presence of Ag nanoparticles. The observed changes in the PL spectrum closely match the expected changes in the line shape due to Fano interaction between discrete level and continuum levels. Our experiment shows that a very small fraction of metal nanoparticles in the metal-semiconductor hybrid is sufficient to induce such changes in line shape which is in contrary to the earlier reported theoretical prediction on metal-semiconductor hybrid.

In this study, we examine dark energy, dark matter and baryonic matter in FRW by observational evidences. Also we study our model by considering possible dark energy candidates such as Phantom energy. Obtained solutions show that dark energy candidate may be phantom energy depending on accuracy of today’s observation.

The mathematical modeling and numerical simulations are expected to play an important role to predict the genesis of different cardiovascular diseases, such as the formation and rupture of aneurysms. In the present work, the numerical solutions of the oscillatory blood flow are constructed for an elastic artery with a model aneurysm by use of the software ANSYS. It is observed that the artery elastic strain behaves in a different way: stably or unstably depending on the different combinations between the flow parameter (outlet pressure) and the elastic modulus of the artery wall.The mathematical modeling and numerical simulations are expected to play an important role to predict the genesis of different cardiovascular diseases, such as the formation and rupture of aneurysms. In the present work, the numerical solutions of the oscillatory blood flow are constructed for an elastic artery with a model aneurysm by use of the software ANSYS. It is observed that the artery elastic strain behaves in a different way: stably or unstably depending on the different combinations between the flow parameter (outlet pressure) and the elastic modulus of the artery wall.

In this paper, a stochastic Gompertzian model is developed to describe the growth process of a breast cancer by incorporating the noisy behavior into a deterministic Gompertzian model. The prediction quality of the stochastic Gompertzian model is measured by comparing the simulated result with the clinical data of breast cancer growth. The kinetic parameters of the model are estimated via maximum likelihood procedure. 4-stage stochastic Runge-Kutta (SRK4) is used to simulate the sample path of the model. Low values of mean-square error (MSE) of stochastic model indicate good fits. It is shown that the stochastic Gompertzian model is adequate in explaining the breast cancer growth process compared to the deterministic model counterpart.

The paper presents a study of ultrasound Rayleigh wave parameters depending on localized plastic strains in AlCu4MgSi alloy and AISI 304 austenitic stainless steel. The ultrasound parameters and motion of localized strain bands were measured in-situ in tensile tests at a constant rate and room temperature. It is shown that by measuring the ultrasound velocity it is possible to detect the initiation of a localized strain band and its location relative to an acoustic measurement area whatever the deformation mechanism.

An analytical calculation for the elastic opening of the cantilever ends of the double cantilever beam specimens under an external couple of forces is commonly performed using the beam theory. In this case, the ligament deformation of the specimen is not taken into account. The effect of elastic deformation of the double cantilever beam specimen ligament on displacements of the cantilever ends under the external load is analyzed in the paper. It is shown that an additional displacement of the cantilever ends can reach 28% of the value calculated by the beam theory. With an increase in the cantilever length, the increment of the cantilever deflection due to the ligament deformation decreases rapidly. Therefore, the contribution of the ligament to the opening of the cantilever ends from a certain length hardly changes.An analytical calculation for the elastic opening of the cantilever ends of the double cantilever beam specimens under an external couple of forces is commonly performed using the beam theory. In this case, the ligament deformation of the specimen is not taken into account. The effect of elastic deformation of the double cantilever beam specimen ligament on displacements of the cantilever ends under the external load is analyzed in the paper. It is shown that an additional displacement of the cantilever ends can reach 28% of the value calculated by the beam theory. With an increase in the cantilever length, the increment of the cantilever deflection due to the ligament deformation decreases rapidly. Therefore, the contribution of the ligament to the opening of the cantilever ends from a certain length hardly changes.

This article discusses the problems that arise during the radiation sterilization of medical products. It is propose the solution based on alanine EPR-dosimetry. The parameters of spectrometer and methods of absorbed dose calculation are given. In addition, the problems that arise during heavy particles irradiation are investigated.

We discuss propagation of traveling waves in a blood-filled hyper–elastic artery with a local dilatation (an aneurysm). The processes in the injured artery are modeled by an equation of the motion of the arterial wall and by equations of the motion of the fluid (the blood). Taking into account the specific arterial geometry and applying the reductive perturbation method in long-wave approximation we reduce the model equations to a version of the perturbed Korteweg-de Vries kind equation with variable coefficients. Exact traveling-wave solutions of this equation are obtained by the modified method of simplest equation where the differential equation of Abel is used as a simplest equation. A particular case of the obtained exact solution is numerically simulated and discussed from the point of view of arterial disease mechanics.

This paper proposed an acoustic technique to estimate size distribution of a cavitation bubble cloud induced by focused ultrasound (FUS) based on the dissolution of bubble cloud trapped by a wide beam of low acoustic pressure, after the acoustic exposure of FUS is turned off. Dissolution of cavitation bubbles in saline and in phase-shift nanodroplet emulsion diluted with degassed saline or saturated saline has been respectively studied to quantify the effects of pulse duration (PD) and acoustic power (AP) or peak negative pressure (PNP) of FUS on size distribution of cavitation bubbles.

The laminar convective heat transfer in a straight microchannel using nanofluids is investigated for a range of Reynolds number and nanoparticle concentration. Three-dimensional conjugate heat transfer in a straight microchannel is numerically analyzed using the ANSYS Fluent commercial CFD code. The effect of volumetric flow rate and nanoparticle concentration on the heat transfer and pumping power is investigated.

In this paper, the structure analysis and optimization for gantry beam of guideway grinder are studied. By using 3D modeling software, the 3D model of gantry beam is established. Then, the gantry beam is analyzed by finite element software. Thus, the change rule of stresses and displacements are obtained. Next, the optimization design for the gantry beam structure is considered and the optimization scheme is proposed. The results show that the maximum stress and displacement of gantry beam for the optimization scheme are clearly decreased. The results verify the rationality and reliability of the optimization design and have certain directive significance to improve the machining accuracy and performance of the grinding machine.