Double Dome Research Articles

Model of the electronic structure of electron-doped iron-based superconductors: evidence for enhanced spin fluctuations by diagonal electron hopping.

We present a theoretical understanding of the superconducting phase diagram of the electron-doped iron pnictides. We show that, besides the Fermi surface nesting, a peculiar motion of electrons, where the next nearest neighbor (diagonal) hoppings between iron sites dominate over the nearest neighbor ones, plays an important role in the enhancement of the spin fluctuation and thus superconductivity. In the highest T(c) materials, the crossover between the Fermi surface nesting and this "prioritized diagonal motion" regime occurs smoothly with doping, while in relatively low T(c) materials, the two regimes are separated and therefore results in a double dome T(c) phase diagram.

열성형 진동판의 미세주름 두께변화가 구조강성 및 진동특성에 미치는 영향 분석

Recently, micro-speakers have attracted much attention due to their increasing demand in mobile devices. Micro-speakers use polymer diaphragms, which are manufactured from thin polymer film by the thermoforming process. The diaphragm is generally designed to be a circular membrane with a cross section consisting of a double dome structure, and a number of corrugations are located in the outer region to produce better sound quality. In the current study, a finite element (FE) analysis is performed for thermoforming, and the resulting thickness reduction in the corrugation regions is estimated. The estimated thickness distribution is used in further structural and modal FE analyses, from which the effects of local thickness reduction on the stiffness and vibration characteristics are determined.

마이크로 스피커 진동판의 형상설계에 따른 진동특성 고찰

Micro-speaker diaphragms play an important role in generating a desired audio response. The diaphragm is generally a circular membrane, and the cross section is a double dome, with an inner dome and an outer dome. To improve the sound quality of the speaker, a number of corrugations may be included in the outer dome region. In this study, the role of these corrugations is investigated using two kinds of finite element method (FEM) calculations. Structural FEM modeling was carried out to investigate the change in stiffness of the diaphragm when the corrugations were included. Modal FEM modeling was then carried out to compare the natural frequencies and the resulting vibrational modes of the plain and corrugated diaphragms. The effects of the corrugations on the vibration characteristics of the diaphragm are discussed.

Spatially Homogeneous Ferromagnetism below the Enhanced Curie Temperature inEuO1−xThin Films

We have used low-energy implanted muons as a volume sensitive probe of the magnetic properties of EuO(1-x) thin films. We find that static and homogeneous magnetic order persists up to the elevated T(C) in the doped samples, and the muon signal displays the double dome feature also observed in the sample magnetization. Our results appear incompatible with either the magnetic phase separation or bound magnetic polaron descriptions previously suggested to explain the elevated T(C), but are compatible with an RKKY-like interaction mediating magnetic interactions above 69 K.

A simple anisotropic hyperelastic constitutive model for textile fabrics with application to forming simulation

A simple hyperelastic constitutive model is developed to characterize the anisotropic and large deformation behavior of textile fabrics. In the model, the strain energy function is decomposed into two parts representing fiber stretches and fiber–fiber interaction (cross-over shearing) between weft and warp yarns. The proposed constitutive model is demonstrated on a balanced plain woven fabric. The actual forms of the strain energy functions are determined by fitting uni-axial tensile and picture-frame shear tests of the woven fabrics. The developed model is validated by comparing numerical results with experimental bias extension data, and then applied to simulation of a benchmark double dome forming, demonstrating that the proposed anisotropic hyperelastic constitutive model is highly suitable to predict the large deformation behavior of textile fabrics.

Double dome osteotomy for the treatment of cubitus varus in children

The purpose of this study was to report double dome osteotomy used to correct paediatric cubitus varus and to avoid lateral prominence after correction. Eighteen children with cubitus varus underwent double dome osteotomy. Preoperative templating created from radiographs was used to determine the bone cuts. Double dome osteotomy created a proximal and distal cut, then varus deformity and sagittal alignment were corrected. The osteotomies were fixed with K-wires and immobilised in a long-arm cast. Radiographics and clinical histories were evaluated. Ulno-humeral angle pre and postoperative, range of motion and lateral prominent index were evaluated. The osteotomy was performed in 18 patients, with an average age of 7.5 years. All patients ended up with flexion of 130° or greater with full and symmetrical pronation and supination. The average ulno-humeral angle difference compared to the uninjured side was 3.27°. The mean of the lateral prominent index was -0.91. The mean follow up was 50.3 months (30-115 months). All of the patients had excellent clinical and radiographic alignment. No revisions were made in this series. One transient radial nerve palsy and one superficial infection occurred. This series demonstrates that double dome osteotomy can provide reliable correction of varus deformity and prevent lateral prominence with a minimal complication rate.

Parametric Modeling of Six Typical Double Reticulated Dome

Based on the structure features of double reticulated domes, a method for node generation and element connection of six typical double reticulated domes was produced. A macro program was designed by using ANSYS Parametric Design Language (APDL). The six typical double reticulated dome modeling was produced under given parameters such as span, rise high, double thickness, grid number in circular and radial direction. It is proved by several examples that this method is simple, efficient and possible. It can be easily used to analyze the internal force and optimized design in shell structures.

Textile composite double dome stamping simulation using a non-orthogonal constitutive model

Stamping is one of the most effective ways to form textile composites in industry for providing high-strength, low-weight and cost-effective products. This paper presents a fully continuum mechanics-based approach for stamping simulation of textile fiber reinforced composites by using finite element (FE) method. A previously developed non-orthogonal constitutive model is used to represent the anisotropic mechanical behavior of textile composites under large deformation during stamping. Simulation are performed on a balanced plain weave composite with 0°/90° and ±45° as initial yarn orientation over a benchmark double dome device. Simulation results show good agreement with experimental output in terms of a number of parameters selected for comparison. The effects of meshing and shear moduli obtained from bias extension test and picture frame test on forming simulation results are also investigated.

Partially Double-Layered Dome Structure Linear and Nonlinear Buckling Analysis

Space steel structure stability has been a focused problem in the engineering field, in the past the study mainly concentrated on the single layer dome structure stability and elastic stability analysis, but with the structure shape complex, new type structure emerges continually, it needs more accurate stability analysis method. In this paper the linear and nonlinear buckling theory and analysis method are introduced firstly, and then a new type steel space structure with partially double layer dome structure is chosen as the computational model. The structure self vibration mode, linear buckling analysis and nonlinear buckling process and buckling characteristics are studied by the FEM commercial code ANSYS; the nonlinear load-deflection curves at the different points are gotten and some conclusions about this kind of structure are drawn.

Numerical and experimental analyses of woven composite reinforcement forming using a hypoelastic behaviour. Application to the double dome benchmark

Continuous textile reinforcements hold crucial role when composites are employed as load bearing components. Numerical simulations of the composite forming processes are essential in the design phase of the composite structures. The continuous approach predicts the mechanical characteristics of woven composite fabrics during forming which considers the fibrous materials as a continuum in average at macroscopic scale. An algorithm based on a hypoelastic behaviour is proposed for the simulation of composite reinforcement forming processes. It is shown here that using hypoelastic law with an objective derivative based on the warp and weft fibre rotation tensors can correctly trace the specific behaviour of the woven materials. A number of elementary tests validate the numerical output with theoretical results and the de facto standard in-plane shear test of picture frame has also been validated numerically. An experimental device for textile composite forming on a double dome has been implemented. This forming case has been defined as an international benchmark of woven composites. The simulations performed with the proposed numerical approach show a good agreement with the experimental results obtained with this double dome device.

Numerical and experimental forming analysis of woven composites with double dome benchmark

Numerical analysis of the forming processes for composite materials has already an acknowledged worth and thus urge to explore even more flexible techniques. The current research is intended to analyse the woven fabric composites using benchmark geometry of double dome for forming. The study has been carried out both experimentally and numerically. The latter has been accomplished by means of a continuous approach; used to analyse numerically the fibrous media exploiting a commercial finite element code i. e. ABAQUS/Explicit. The use of hypoelastic law with an objective derivative based on the fibre rotation tensor makes it possible to track the re-orientation of fibres after deformation. The user material subroutine VUMAT has been developed to incorporate the algorithm and the formulations adopted for fibrous media analysis. The tests have been executed by selecting two different orientations of fabric with respect to the edges of the die or punch. The experimental tests have been duly performed with a local development of forming tools. The digital image correlation (DIC) has also been exploited treating only the final form of the woven reinforcements to measure the shear angles. The numerical results corroborate very well with the experimental output in terms of a number of parameters selected for comparison.

Forming simulation of a thermoplastic commingled woven textile on a double dome

This paper presents thermoforming experiments and FE simulations of a commingled glass-PP woven composite on a double dome geometry, with the aim of assessing the correspondence of predicted and experimental shear angles. Large local deformations - especially in-plane shear, i.e. relative rotation between the two yarn families – occur when draping a textile on a three dimensional part and eventually unwanted phenomena like wrinkling or tearing may occur. The macroscopic drape behaviour of a weave is generally subdivided into: 1) The high tensile resistance along the yarn directions, expressed as non-linear stress-strain curves, and 2) The shear resistance, expressed as non-linear shear force versus shear angle curves. The constitutive model is constituted of a dedicated non-orthogonal hypo-elastic shear resistance model, previously described in [1, 2], combined with truss elements that represent the high tensile resistance along the yarn directions. This model is implemented in a user subroutine of the ABAQUS explicit FE solver. The material parameters have been identified via textile biaxial tensile tests at room temperature and bias extension tests at 200°. Thermoforming experiments are performed on a rectangular blank with the warp direction along the second symmetry plane of the tool, with a preheating temperature of 200°C, a constant mold temperature of about 70°C, and a blankholder ring. It was concluded that the shear angles were fairly well predicted for this particular case study, which could be expected in view of the fact that no wrinkles had formed during the thermoforming experiment.

Preforming simulation of the reinforcements of woven composites: continuous approach within a commercial code

Contrary to the classical continuous media of metallic structures, fibrous composites have a very specific mechanical behaviour due to their composition. The prediction of the properties in simulating the forming processes of woven reinforcements necessitates special analysis methods. The objective of this research work is to present the continuous approach which can be exploited within a commercial code (e.g. ABAQUS, used here). For that we treat, primarily, the elementary tests with continuous approach in large deformations with three different methods i.e. single element with unidirectional fibers, single element with bidirectional fibers and two superimposed elements with unidirectional fibers. The tests are performed using locally developed user material subroutine (VUMAT) for membrane elements in ABAQUS/Explicit. The numerical results of the elementary tests conform with each other and to the exact analytical solutions. Also, these tests are extended to the bias extension test, picture frame test, hemispherical dome forming and the international benchmark draping of double dome. The numerical outputs reasonably corroborate with experimental tests.

Contribución al estudio anatomo-morfológico del suelo pélvico en la mujer asintomática: utilización de la imagen por RMN

To confirm the results of previous studies demonstrating the morphology of the levator ani muscle in the living subject is different to that described in classic anatomical works; to evaluate the anatomical-morphological differences of the pelvic floor between nulliparous and multiparous women in order to analyze the influence of pregnancy and delivery. Comparative study of the morphological variations of the iliococcigeous fascicle of the levator ani muscle between two groups of females using T2 MRI.: the first group included 11 nulliparous women and the second group 9 multiparous women. The curvature radium of the fascicles was calculated in the frontal projections. The differences in height were also calculated. The anterior limit of the iliococcygeal muscle dome was determined in the sagittal plane. The software Image Tool 3.0 was employed for the measurements. The Kolmogorov-Smirnov test was employed to analyze the distribution of the study populations; mean value comparisons between groups were performed by the Student's t test. Finally, the various morphological measurements were compared in relation to various parameters: parity, side, body mass index (BMI), sports practice, menstrual cycle phase, and presence or absence of episiotomy. Data obtained were analyzed using the Fisher's exact test, with a statistical significance of p < 0.05. Morphological measurements: We observed that the concavity of the iliococcygeal fascicle dome is larger in nulliparous women (p = 0.03 for the right side and p = 0.04 for the left). Moreover, these women have the domes significantly more anterior (p < 0.001 for both sides). Comparisons between other variables: an association between nulliparous status and the presence of a higher and more anterior left dome, and multiparous status and a higher and more anterior right dome were (p = 0.02). The hypothesis of the pelvic floor morphology being a double dome with inferior-posterior concavity in the living asymptomatic female is confirmed. We also demonstrate the existence of anatomical-morphological differences in the iliococcygeal muscle of the levator ani between nulliparous and multiparous females, which seems to confirm a relationship with pregnancy and/or delivery.

2313 薄膜金属ガラスを用いた集積形ERマイクロアクチュエータ(OS8-3 アクチュエータシステム(3))

A novel 3-DOF ER micractuator using thin film metallic glass was proposed and fabricated. The actuator consists of 3-DOF stacked diaphragms and a micro ER valves unit. By internal stress elimination in the supercooled liquid region and wide elastic range of thin film metallic glass, the diaphagms have capability to generate large displacement. In this paper, as a simple diaphagm configulation for larger displacement, a double dome diaphragm was obtained based on FEM analysis. Through fabrications using MEMS process, process conditions to fabricate the double dome diaphragms were experimentally clarified. Also, the micro ER valves unit large model was fabricated and the valve control characteristics were experimentally clarified.

Fibre Orientation Modelling for Rubber Press Forming of Thermoplastic Laminates

The fibre re-orientation caused by the press forming of thermoplastic composites is one of the main factors in the process induced product distortions. Classical geometric drape simulation methods can be used to predict this fibre re-orientation. However, these methods have difficulties to incorporate the process specific boundary conditions. Therefore, a fabric reinforced fluid model was implemented into the Finite Element package DIEKA, which is capable of modelling the boundary conditions as well. The predictions of both types of simulations are compared with the results of drape experiments on a double dome geometry.

3-D elastic prestack, reverse‐time depth migration

By combining and extending previous algorithms for 2-D prestack elastic migration and 3-D prestack acoustic migration, a full 3-D elastic prestack depth migration algorithm is developed. Reverse‐time extrapolation of the recorded data is by 3-D elastic finite differences; computation of the image time for each point in the 3-D volume is by 3-D acoustic finite differences. The algorithm operates on three‐component, vector‐wavefield common‐source data and produces three‐component vector reflectivity distributions. Converted P‐to‐S reflections are automatically imaged with the primary P‐wave reflections. There are no dip restrictions as the full wave equation is used. The algorithm is illustrated by application to synthetic data from three models; a flat reflector, a dipping truncated wedge overlying a flat reflector, and the classical French double dome and fault model.

Annual Meeting of the American Academy of Facial Plastic and Reconstructive Surgery

From September 29 through October 1, 1993, the American Academy of Facial Plastic and Reconstructive Surgery held its annual meeting in Minneapolis, Minn. A new technique for nasal tip refinement was presented by Geoffrey W. Tobias, MD, Englewood, NY. The technique, which he calls modified universal tiplasty, involves division of the medial crura of the lower lateral cartilages with subsequent double dome suturing of the tip. The author explained that this converts the tip structure from the familiar tripod to an A-frame. He believes that by first dividing the medial crura, the tip becomes more pliable and can be fashioned into a more natural appearance. An 8-year experience in 935 patients was reviewed. All of his procedures were performed through a delivery technique. Complications consisted of infection and columellar retraction. The author stated he has not had problems with unwanted deprojection. He believes the real advantage is that none of

A Modified Goldman Nasal Tip Procedure for the Drooping Nasal Tip

A modification of Irving Goldman's nasal tip procedure that borrows from the lateral crus to augment the height of the medial crus is described. Goldman's procedure has been modified by not including the vestibular skin with the segment of the lateral crus that is rolled medially to increase nasal tip projection, by adding a nasal septal cartilage strut between the medial crura for support when the medial crura are weak, and by maintaining a small separation caudally of the repositioned lateral crura at the new nasal dome to simulate a double nasal dome. This modified Goldman nasal tip procedure allows the surgeon to reshape the lower lateral nasal cartilage to increase nasal tip projection as an alternative to the use of a shield-type nasal tip graft, and at the same time it narrows the nasal tip with minimal resection of the lateral crus of the lower lateral nasal cartilage.

Geochemistry of ultramafic and calc-llkaline lamprophyres from the Lac Shortt area, Quebec

Petrographic and geochemical data are presented for the Lac Shortt lamprophyre dyke swarm. The primary mineralogy in all samples has been largely destroyed either by alteration at the time of emplacement or by subsequent metamorphism. Most of the dykes are ultramafic lamprophyres. Extended trace element plots (ETP) for these dykes feature a characteristic double dome pattern, with one dome extending between Sr and Zr and the other between Zr and Yb. One ultramafic dyke was selected for detailed study. The ETP and rare earth element (REE) curves for the analyses of this dyke are essentially parallel, indicating the relative immobility of both groups of elements during the subsequent events. Significant correlation coefficients between the high field strength elements using phosphorus as representative of these elements, and the major element concentrations suggests that these were also relatively immobile. Pearce plots and principal component analyses reveal that olivine and apatite fractionation controlled the chemical variation across the control dyke. A plot of Nb anomalies against silica for Precambrian ultramafic and cafe-alkaline lamprophyres reveals two clear groupings—the former has no such anomalies in contrast to the latter which possesses this feature. A calc-alkaline lamprophyre dyke from the Lac Shortt Mine features significant Nb depletion on ETP suggesting that magmas with low Si02 content Si02 = 35.85 weight and chondrite normalized La = 1458) may be related to this catagory of lamprophyre.