Eccentric Core Research Articles

Nonlinear liquid oscillation in a cylindrical tank with an eccentric core barrel

The nonlinear liquid motion in a partially filled cylindrical tank with an eccentric core barrel is investigated. The nonlinearity of the liquid surface oscillation is considered in the response analysis of the sloshing motion. Basic equations are derived by employing the variational principle. The nonlinear ordinary differential equations governing the liquid surface oscillation are then derived by applying Galerkin's method to the basic equations. The admissible functions of the velocity potential and liquid surface displacement are assumed to be represented by combining the modal functions obtained by the linearized analysis. The effects of the eccentricity of core barrel on liquid surface oscillation are discussed. The time histories of the liquid surface displacement are calculated to the harmonic pitching excitations. An experiment was conducted using a model tank. A good agreement was found between the theoretical and experimental results. It is shown that the nonlinear analysis is important for estimating the sloshing responses.

Surface/interface effects on elastic behavior of a screw dislocation in an eccentric core–shell nanowire

The elastic behavior of a screw dislocation which is positioned inside the shell domain of an eccentric core–shell nanowire is addressed with taking into account the surface/interface stress effect. The complex potential function method in combination with the conformal mapping function is applied to solve the governing non-classical equations. The dislocation stress field and the image force acting on the dislocation are studied in detail and compared with those obtained within the classical theory of elasticity. It is shown that near the free outer surface and the inner core–shell interface, the non-classical solution for the stress field considerably differs from the classical one, while this difference practically vanishes in the bulk regions of the nanowire. It is also demonstrated that the surface with positive (negative) shear modulus applies an extra non-classical repelling (attracting) image force to the dislocation, which can change the nature of the equilibrium positions depending on the system parameters. At the same time, the non-classical solution fails when the dislocation approaches very close to the surface/interface with negative shear modulus. The effects of the core–shell eccentricity and nanowire diameter on dislocation behavior are discussed. It is shown that the non-classical surface/interface effect has a short-range character and becomes more pronounced when the nanowire diameter is smaller than 20nm.

An Unconventional Role of Ligand in Continuously Tuning of Metal–Metal Interfacial Strain

We show that embedding of a surface ligand can dramatically affect the metal-metal interfacial energy, making it possible to create nanostructures in defiance of traditional wisdom. Despite matching Au-Ag lattices, Au-Ag hybrid NPs can be continuously tuned from concentric core-shell, eccentric core-shell, acorn, to dimer structures. This method can be extended to tune even Au-Au and Ag-Ag interfaces.

Coupled-Mode Analysis for Chiral Fiber Long-Period Gratings Using Local Mode Approach

Starting from the conventional coupled-mode theory and using the mode transformation method, a unified local mode approach is presented to analyze the chiral fiber long-period gratings (CLPGs) formed by twisting a high-birefringence fiber as an example of a chiral fiber with double-helix symmetry. Similarly, a helical-core fiber, as an example of single-helix CLPGs, is analyzed by using the ideal mode approach. The coupled-mode equations for both the cases are transformed and reduced to two-mode equations. The derivation is simple, and the results are explicit in concept. These results reveal the scheme of polarization selectivity of mode coupling, and for the first time, the necessary condition for achieving the polarization selection is given. The analysis indicates that conventional coupled-mode theory is efficient for studying chiral fiber grating, and more importantly, it is better to be understood. A numerical simulation has been done on a twisted conventional Panda fiber with a beat length of 2.5 mm. It has been shown that in a right-handed twisted structure, a total power transfer of a right-handed circular polarization light is obtained with a grating pitch of 0.382 mm and a grating length of 64.9 mm at the wavelength of 1.55 μm . On the other hand, through the simulation on single-helix CLPG with an eccentric core, it has been shown that a total power transfer of the core mode to LP <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">11</sub> mode is obtained with a grating pitch of 0.723 mm and a grating length of 10.46 mm at the wavelength of 1.55 μm.

Analytical estimation of liquid film thickness in two-phase annular flow using electrical resistance measurement

This paper presents an analytical solution to estimate the liquid film thickness in two-phase annular flow through a circular pipe using electrical resistance tomography. Gas–liquid flow with circular gas core surrounded by a liquid film is considered. Conformal mapping is employed to obtain the analytic solution for annular flow with an eccentric circular gas core. The liquid film thickness for an arbitrary annular flow is estimated by comparing the resistance values for concentric and eccentric annular flows. The film thickness estimation has a good performance when the normalized distance between the gas core center and the flow center is less than 0.2 and the void fraction is greater than 0.4, the estimated error of the normalized thickness is less than 0.04.

Eccentric core single-mode fiber optical attenuator

An all-fiber optical attenuator is fabricated by splicing an eccentric core single-mode fiber (ECSMF) between two single-mode fibers (SMFs).The attenuation is mainly caused by the core offset between the ECSMF and the SMFs. Attenuators with different attenuations were fabricated. The device is simple, reliable, economical, and temperature independent. © 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett 53:1236–1238, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26003

Multi-Beam Interference Transmission Spectrum Observed from an Eccentric Core Single-Mode Fiber

An eccentric core single-mode fiber, whose core is away from the axis of the fiber, is fabricated by using the fiber preform goniometric-groove method and the stack-and-draw method. An eccentric core single-mode fiber without coating is spliced between two single-mode fibers. Fundamental mode and cladding modes are excited at one splicing point between the eccentric core single-mode fiber and the single-mode fiber, and propagate in the eccentric core single-mode fiber, then interfere with each other at the other splicing point. Multi-beam interference transmission spectrum is observed. An in-line fiber interferometric strain sensor based on the eccentric core single-mode fiber is realized.

Cellular response in semi-intensively cultured sea bream gills to Ergasilus sieboldi (Copepoda) with emphasis on the distribution, histochemistry and fine structure of mucous cells

Light and ultrastructure studies were carried out on gill of sea bream, Sparus aurata L., naturally infected with Ergasilus sieboldi (Copepoda) to assess pathology and host cell responses. Thirty S. aurata were examined, and 23 (74%) were infected, the intensity of infection ranging from 3 to 50 parasites per host. The copepod encircled gill lamellae with its second antennae, occluded arteries, compressed the epithelium, provoked hyperplasia and haemorrhage, and often caused tissue disruption. Adjacent to the site of attachment, rodlet cells (RCs), mast cells (MCs) and mucous cells were observed. In parasitized fish, mucous cells were more abundant in infected gills than in uninfected (t-test, P<0.01), while no significant differences were encountered in the numbers of RCs and MCs between gill of infected and uninfected fish (t-test, P>0.01). In both infected and uninfected gill, the RCs were within the primary lamella and also sometimes occurred in secondary lamella. In healthy and infected gill, MCs were free within the connective tissue inside and outside the blood vessels of the primary lamellae and made close contact with vascular endothelial cells. Infected and uninfected gill mucous cells stained positively for neutral muco-substances (PAS positive). In all sea bream, gill mucous cells presented a central or eccentric electron-dense core within the mucus granules.

Histochemical and Ultrastructural Observations of Respiratory Epithelium and Gland in Yak (Bos grunniens)

Submucous glands and epithelial mucous cells of yak (Bos grunniens) respiratory tract have been studied by a variety of histochemical methods and transmission electron microscopy for differentiating and characterizing serous and mucous cells. By light microscopy, the distribution, numbers of mucous cells, volume of mucous glands (Reid index), and the ratio of mucous cell to serous cell in the bronchial tree were measured with different staining. Histochemically, a majority of mucous cells, presented in the surface epithelium of bronchi and glands, secreted neutral and acid mucosubstances, only a few sulfated mucosubstances were present. No mucus-producing cells were observed from the terminal to respiratory bronchiolar level. Ultrastructurally, serous cells in glands of the lamina propria had two distinct forms: one type filled with many round dense secretory granules, plentiful RER and few other organelles, similar to other animals; the other type contained some oval mitochondrial and distended RER, the granules resembled the former. The mucous cells in gland were similar to that of epithelium, which containing abundant secretory granules with an eccentric core. The mucous cells of the surface epithelium differ from other animals in the structure and histochemistry of their secretory granules. Analysis of the size and distribution of the secretory granules and other organelles of serous cells suggested that differences represent different phases of a secretory cycle, not various populations of cell or granules.

Highly Sensitive Bend Sensor Based on Bragg Grating in Eccentric Core Polymer Fiber

We report on an optical bend sensor based on a Bragg grating inscribed in an eccentric core polymer optical fiber. The device exhibits the strong fiber orientation dependence, the wide bend curvature range of ±22.7 m-1, and high bend sensitivity of 63 pm/m-1.

Calculation of Temperature Distribution in Eccentric Multi Core Diode Pumped Fiber Lasers by Green Function Method

In this paper, the temperature distribution in fiber lasers pumped by multi diode bars located in out-of-fiber axis has been investigated semi-analytically. For this reason, we consider heat deposition in fiber lasers due to pump and the nonhomogeneous heat conduction equation has been solved by using Green function method in a cylindrical coordinate system. Our model has been used for single, double and multi pumped configuration and, for a typical fiber lasers, the results have been plotted and discussed.

Seismic Performance of Strengthened Reinforced Concrete Beam-Column Joints Using FRP Composites

Three nonseismically detailed interior reinforced concrete beam-column joints, namely, one eccentric and two concentric joints, strengthened with proposed fiber-reinforced polymer (FRP) wrapping configurations using glass fiber-reinforced polymer and carbon fiber-reinforced polymer strips and sheets, were tested under constant axial compression load and reversed cyclic loading which simulated low to moderate earthquake forces. Seismic performance of the strengthened beam-column joints in terms of their hysteresis response, stiffness, and energy dissipation capacity is evaluated and compared to those of the original and unstrengthened beam-column joints. Results indicate that applying strips at 45º on a flushed eccentric joint core and as cross bracing on the beam and confinement round the column is very effective. All specimens failed with gradual strength deterioration, bond degradation, and debonding of FRP sheets was observed near the joint core. The proposed strengthening schemes were found to be efficient and economical for mass repair or upgrading of nonseismically detailed structures.

Metal−Polymer Hybrid Colloidal Particles with an Eccentric Structure

We have synthesized metal-polymer hybrid colloidal particles characterized by an eccentric structure by precipitation polymerization in the presence of metal colloids. The key to the formation of an eccentric core-shell structure was to introduce metal colloids a few minutes after (rather than before) starting the polymerization. The hybrid particles were uniform in size, and each one of them contained only one metal nanoparticle at its surface after the experimental procedures had been optimized. This method could be extended to a number of different metal colloids stabilized by small molecules, and the yield was found to be more or less independent of the size of the metal nanoparticles. In addition, the position of the metal nanoparticle in the hybrid particle could be controlled by changing the concentration of cross-linker, and the overall size of the hybrid particles could be altered by solvent treatment. Because of the simplicity of this procedure, it should be possible to use it for the large-scale production of colloidal particles having a hybrid, complex structure.

The morphological study on the adrenal gland of African ostrich chicks

The morphology of the adrenal gland has been studied for a number of animal species all over the world, yet the detailed data about ostrich chick has not been reported. In the present study, the morphological features of the adrenal gland in African ostrich chicks were investigated by means of gross anatomy, light and electron microscope. Differences between the left and right adrenal glands were found in shape, size and location. The interrenal tissue and chromaffin cell interdigitated irregularly. The interrenal tissue was divided into a peripheral zone (PZ) and a central inner zone (CZ), and the PZ was further distinguished into an outer area (subcapsular zone, SCZ) and an inner area (IZ). The cellular arrangement in these zones showed evident zonation that resembled the mammalian. This phenomenon had been previously described only for the pelicanus. The cytoplasm of interrenal cells in SCZ was stained lightly than in IZ and CZ, and contained several vacuoles. Additionally, unlike CZ cells, SCZ cells appeared to contain more mitochondria and less lipid droplets. Two types of chromaffin cells: epinephrine cells and norepinephrine cells could be detected. The type 1 granules possessed a central core and a variable distance between membrane and core; the type 2 granules had an eccentric core, which leant to one side of granule and sticked to the membrane, giving a lager lacouna appearance in another side of the granule.

Synthesis of Eccentric Titania−Silica Core−Shell and Composite Particles

We describe a novel method to synthesize colloidal particles with an eccentric core−shell structure. Titania−silica core−shell particles were synthesized by silica coating of porous titania particles under Stober (Stober et al. J. Colloid Interface Sci. 1968, 26, 62) conditions. We can control access of silica to the pores in the titania, allowing us to produce either core−shell or composite particles. Calcination of the core−shell particles gives unique eccentric core−shell structures, as a result of extensive shrinkage of the highly porous titania core with respect to the silica shell. However, when the titania particles are silica treated prior to drying they result in composite titania−silica spheres, where two materials are mixed uniformly. These spheres are interesting for catalysis, (switchable) photonic crystal applications, optical tweezing, and new titiana based materials. We demonstrate photocatalytic activity of the eccentric spheres where the silica layer acts as a size selective membrane.

Generation and conversion of optical vortices in long-period helical core optical fibers

We theoretically study generation and conversion of optical vortices (OVs) in long-period helical core fibers (HCFs) produced by drawing from a perform with an eccentric core. Solving scalar waveguide equation in the helical coordinates we demonstrate that in such fibers topologically induced corrections to scalar propagation constants lead to convergence of spectral curves. At their intersection points a resonance coupling takes place between the fundamental and the vortex modes, as well as the coupling between OVs, whose topological charges differ by unity. This coupling leads to energy exchange between the coupled modes, which is manifested either in conversion of the input fundamental mode into an OV or transformation of an OV into the OV with higher by 1 (or lower, depending on core's helicity) value of the topological charge. This effect can be used for creation of all-fiber generators of singular beams from regular input beams. We also study effect of ellipticity of the core's form on transformation properties of HCFs and show that this leads to splitting of resonance fiber's parameters, at which conversion of left and right circularly polarized input regular beams into OVs occurs. We prove that in long-period HCFs one can neglect this effect due to reduction of polarization mode dispersion in twisted fibers.

Scattering and Absorption of Sound by a Compound Cylindrical Porous Absorber with an Eccentric Core

The classical method of separation of variables along with the novel features of Biot theory of dynamic poroelasticity and the translational addition theorem for cylindrical wave functions are employed to present an exact solution for interaction of a plane acoustic wave with a composite cylindrical sound absorber suspended in air. The analytical results are illustrated with numerical examples in which a compound cylindrical absorber made of selected configurations of two common sound absorbent materials (plastic foam and light glass wool), is insonified by plane sound waves at selected angles of incidence. The backscattered form function amplitude as well as the absorption cross section spectra are calculated and discussed for representative values of the parameters characterizing the system. The effects of incident wave frequency, angle of incidence, core eccentricity and coating thickness are examined. Limiting cases are considered and fair agreements with available solutions are obtained.

249 複数の構造物を有する円筒容器内液面の非線形振動

249 複数の構造物を有する円筒容器内液面の非線形振動

Immunohistochemical localization of huntingtin-associated protein 1 in endocrine system of the rat.

Huntingtin-associated protein 1 (HAP1) was originally found to be localized in neurons and is thought to play an important role in neuronal vesicular trafficking and/or organelle transport. Based on functional similarity between neuron and endocrine cell in vesicular trafficking, we examined the expression and localization of HAP1 in the rat endocrine system using immunohistochemistry. HAP1-immunoreactive cells are widely distributed in the anterior lobe of the pituitary, scattered in the wall of the thyroid follicles, or clustered in the interfollicular space of the thyroid gland, exclusively but diffusely distributed in the medullae of adrenal glands, and selectively located in the pancreas islets. HAP1-containing cells were also found in the mucosa of stomach and small intestine with a distributive pattern similar to that of gastrointestinal endocrine cells. However, no HAP1-immunoreactive cell was found in the cortex of the adrenal gland, the testis, and the ovary. In the posterior lobe of the pituitary, HAP1-immunoreactive products were not detected in the cell bodies but in many stigmoid bodies, one kind of non-membrane-bound cytoplasmic organelle with a central or eccentric electron-lucent core. HAP1-immunoreactive stigmoid bodies were also found in the cytoplasm of endocrine cells in the thyroid gland, the medullae of adrenal gland, the pancreas islets, the stomach, and small intestine. The present study demonstrates that HAP1 is selectively expressed in part of the small peptide-, protein-, and amino-acid analog and derivative-secreting endocrine cells but not in steroid hormone-secreting cells, suggesting that HAP1 is also involved in intracellular trafficking in certain types of endocrine cells.

High Hamstring Tendinopathy in RunnersMeeting the Challenges of Diagnosis, Treatment, and Rehabilitation

High hamstring tendinopathy is an uncommon overuse injury seen in running athletes. Patients typically report deep buttock or thigh pain. A detailed physical examination and, occasionally, imaging studies are necessary to confirm the diagnosis. Rehabilitation involves soft-tissue mobilization, frequent stretching, and progressive eccentric hamstring strengthening and core stabilization exercises. In recalcitrant cases, an ultrasound-guided corticosteroid injection into the tendon sheath can be helpful, and, occasionally, surgery may be necessary to release the scar tissue around the proximal hamstring muscles and the sciatic nerve.