Cross Shape Research Articles

Photoexcitation ofHe−Hollow-Ion Resonances: Observation of the2s2p2 P4State

Highly correlated states are studied in He-, a fundamental 3-electron system and prototypical negative ion. The 2s2p(2) 4P state is observed for the first time. This state is detected in a resonant simultaneous double-Auger decay of unprecedented strength. In addition, the first measurements of photodetachment cross sections, positions, widths, and shapes of triply excited resonances in He- are reported. These measurements provide a sensitive test for several sophisticated ab initio calculations, and indicate differences in the position and shape of some structures.

Pressure field in flow through uniform straight pipes with varying wall cross curvature

Pressure fields in rigid smooth straight tubes with an axially uniform cross section, in which an incompressible Newtonian fluid flows steadily, have been determined. Five cross section shapes are used. The reference cross section S 0 is slightly elliptic (ellipticity of 1.005). Four cross section shapes, which mimic collapsed vessels in an uniformly frozen state, are defined according to the curvature of their opposite faces (the mid-face is located on the minor axis) S q (parallel faces), S t (face folding), S c (point contact between faces) and S ℓ (line contact). These four selected cross shapes are characterized by large changes in both the cross sectional shape and area with respect to S 0 . The cross shapes are obtained from the computation of the deformation under uniform transmural pressures, without extension, of a thin-walled conduit of infinite length and of homogeneous purely elastic walls of constant thickness. The Navier–Stokes equations are solved using the finite element method for the five tubes ∑ 0 , ∑ q , ∑ t , ∑ c and ∑ ℓ , which are associated with S 0 , S q , S t , S c and S ℓ , respectively. The numerical tests are performed with the same value of the volume flow rate whatever the tube configuration for three Reynolds numbers ( R e 0 = 35 , 500 and 1000). The present work is aimed at studying the pressure field for the design of the flow chamber in which endothelial cells are cultured. This field is used not only to define a new relative pressure index to determine the entry length but also to estimate the wall shear stress when the flow is fully developed.

ENHANCEMENT OF BLOWOUT LIMIT BY THE INTERACTION OF MULTIPLE NONPREMIXED JET FLAMES

The effects of interaction between nonpremixed flames on the enlargement of blowout velocity are experimentally investigated. Nozzle separation distances, fuel flow rates, number of nozzles, and array shapes are considered to make flame interaction. Four types of nozzle arrays, which are arranged in diamond, cross, matrix, and circle shapes, are used. Interacting flame has two distinct characteristics compared with a single jet flame—higher blowout velocity and constant turbulent liftoff heights. There are optimum nozzle separation distances for the augmentation of blowout limit. Blowout velocities for the small-diameter multiple jets are higher than a single large-diameter nozzle with the same area. The flames are not extinguished even in choking conditions at the nozzle exit when there is not a nozzle at the center of optimally spaced matrix- or circle-shaped configurations. Flow visualization shows that the enhanced stability in the case without a center nozzle is due to recirculation within the fuel jet arrays.

膝蓋けん断裂に人工靭帯を使用した治療経験

Patellar tendon rupture rarely occurs in adults without systemic diseases. We report two cases of fresh patellar tendon rupture treated with augmentation using the Leeds-Keio artificial ligament. The remnants of the ruptured tendon were preserved. The artificial ligament was passed transversely through the distal end of the quadriceps tendon along the proximal margin of the patella and it crossed itself in front of the patella in a cross shape. Both ends of the implant were passed through a transverse tunnel drilled through the tibial tuberosity. CPM exercise was begun on the second day after surgery. Active knee extension was permitted at three weeks postoperatively. The advantages of this method are there is no need for immobilization and that rehabilitation is much quicker.

Transluminal EndosurgerySingle Lumen Access Anastomotic Device for Flexible Endoscopy

Forming anastomoses between two hollow organs at flexible endoscopy might reduce the need for surgery for obstructing malignancy. Current methods require access to both lumens. The aim of this work was to develop methods of forming an anastomosis at flexible endoscopy, such as a gastrojejunostomy or cholecystoduodenostomy, when access to only one lumen is feasible. A modified needle was passed through a large-channel echoendoscope from the accessible lumen into the target hollow organ. An anastomotic device was formed by using two 7F catheter segments, which were pushed over a guidewire into the target, the less accessible lumen. When released, by withdrawing the guidewire, the catheters formed a cross shape and created an anastomosis when compressed against a plate from the accessible side. These devices were tested in live animal experiments. With an echoendoscope in the stomach, it was repeatedly possible to place needles, threaded tags, and guidewires into the small intestine and gallbladder. In 4 to 7 days, anastomoses were formed in 16 pigs between the small intestine and the stomach, and between the gallbladder and the stomach. The initial diameter of the anastomoses ranged from 3 to 9 mm. No complication occurred. It is feasible to form anastomoses at flexible endoscopy when access is limited to a single side.

Transluminal Endosurgery: Single Lumen Access Anastomotic Device for Flexible Endoscopy

Background Forming anastomoses between two hollow organs at flexible endoscopy might reduce the need for surgery for obstructing malignancy. Current methods require access to both lumens. The aim of this work was to develop methods of forming an anastomosis at flexible endoscopy, such as a gastrojejunostomy or cholecystoduodenostomy, when access to only one lumen is feasible. Methods A modified needle was passed through a large-channel echoendoscope from the accessible lumen into the target hollow organ. An anastomotic device was formed by using two 7F catheter segments, which were pushed over a guidewire into the target, the less accessible lumen. When released, by withdrawing the guidewire, the catheters formed a cross shape and created an anastomosis when compressed against a plate from the accessible side. Observations These devices were tested in live animal experiments. With an echoendoscope in the stomach, it was repeatedly possible to place needles, threaded tags, and guidewires into the small intestine and gallbladder. In 4 to 7 days, anastomoses were formed in 16 pigs between the small intestine and the stomach, and between the gallbladder and the stomach. The initial diameter of the anastomoses ranged from 3 to 9 mm. No complication occurred. Conclusions It is feasible to form anastomoses at flexible endoscopy when access is limited to a single side.

Two-Dimensional Nucleation with Edge and Corner Diffusions

The effect of edge and corner diffusions on the morphology and on the density of islands nucleated irreversibly on a flat substrate surface is studied. Without edge and corner diffusion, islands are fractal. As an edge diffusion constant D e increases, islands tend to take a cross shape with four needles in the <10 > direction. Additional corner diffusion with a diffusion constant D c yields square islands. When D e is small relative to the surface diffusion constant D s , the square corner shows the Berg instability to produce hopper growth in the <11 > direction. The corner diffusion influences the island number density n . At a deposition flux F with a small D c , mainly monomers are mobile and n ∝( F / D s ) 1/3 . At large D c , dimers and trimers are also mobile and n ∝ F 3/7 D s -5/21 D c -4/21 . The F dependence is in good agreement to the rate equation analysis, but the dependence on D c cannot be explained by the theory.

406 ダブレット型粉粒体吸込みノズル入口形状に関する研究 : 十字ノズルの影響

406 ダブレット型粉粒体吸込みノズル入口形状に関する研究 : 十字ノズルの影響

Effect of stray field induced by cross shape in a 200-nm-wide Co wire

200-nm-wide Co wires connected to two 1-μm-width crossing probes, which play domain-wall-trap sites with a variable interval between the two probes in the range from 2 to 10 μm, were fabricated by using electron-beam lithography. The relation between the magnetization switch of the wire and the probe interval was studied by measuring the longitudinal magnetoresistance. The switching field enlarged with increasing the probe interval at the shorter length ( <6 μ m), and seemed to saturate at longer length ( >6 μ m). The resistance changes during the magnetization reversal reduced with increasing the probe interval. These behaviors were explained by considering the stray field caused by the magnetic charge generated at the boundary between the crossing and the wire regions.

M - P -ϕ Diagrams for Reinforced, Partially, and Fully Prestressed Concrete Sections under Biaxial Bending and Axial Load

An analytical model that determines the M-P-f diagrams including the inelastic structural re- sponse, ultimate strength, and failure mode of reinforced concrete, partially prestressed concrete, and fully prestressed concrete sections of any cross shape under combined biaxial bending and axial load is presented. The proposed method uses (1) a nonlinear stress-strain relationship for the concrete; (2) a multilinear elastic- plastic relationship for the conventional reinforcement; (3) a modified Ramberg-Osgood function for the pre- stressed steel; and (4) Gauss's integral method for equilibrium at the sectional level. The proposed method can be utilized to study the effects of creep, confinement, and tension-stiffening of the concrete and relaxation of the prestressed steel on the behavior, strength, ductility, and failure mode of reinforced concrete, partially pre- stressed concrete, and fully prestressed concrete sections under biaxial bending and axial load. The biaxial bending behavior, ultimate strength, failure mode, and M-P-f diagrams of any concrete section can be obtained using a minicomputer, and as expected, they depend on (1) cross-sectional characteristics and reinforcement layout; (2) the constitutive stress-strain characteristics of the concrete and reinforcements; and (3) the type and intensity of applied loads. Two numerical examples are presented in detail to verify and show the effectiveness of the proposed method.

A Greek cross dodecaphenylene: sparteine-mediated asymmetric synthesis of chiral D2-symmetric π-conjugated tetra- o-phenylenes

The asymmetric synthesis of a chiral, nonracemic π-conjugated system with D 2 point group of symmetry, dodecaphenylene 4 is described. In the key step, (−)-sparteine- and Cu(II)-mediated oxidation of 2,2′-dilithio-1,1′-biaryls in ether gives the corresponding dimers, tetra- o-phenylenes, in 80% isolated yields and 50–60% ee's. X-Ray crystallography confirms the structure of rac- 4 and its molecular shape of a Greek cross. The torsional angles between the benzene rings in the tetra- o-phenylene core of rac- 4 are in the 56.5–71.0° range. However, CD and UV spectra of 4 in CH 2Cl 2 are consistent with significant conjugation between the four terphenyl moieties.

Effect of triangular and elongated plasma shape on the sawtooth stability

In the TCV tokamak the sawtooth period and the sawtooth amplitude areobserved to depend strongly on the shape of the poloidal plasma cross section.Systematic scans of plasma elongation and triangularity show small sawteethwith short periods at high elongation or low and negative triangularity, andlarge sawteeth with long periods at low elongation or high triangularity.Additional central electron cyclotron heating power further amplifies theshape dependence of the sawtooth properties. The sawtooth period can increaseor decrease with additional heating power depending on the plasma shape.This shape dependence is determined by the role of ideal or resistiveMHD in triggering the sawtooth crash. For plasma shapes where additional heating and, consequently, a higher pressure shortens the sawtooth period, the low experimental limit of the pressure gradient within the q = 1 surface is consistent with ideal MHD predictions. The observed decrease of this limit with elongation is also in qualitative agreement with ideal MHD theory.

Hamiltonian magnetic reconnection

Magnetic reconnection in two dimensional (2D), collisionless, non-dissipative regimes is investigated analytically and numerically by means of a finite difference code in the nonlinear regime where the island size becomes macroscopic. The cross-shaped structure of the reconnection region, originally reported by Cafaro et al (1998 Phys. Rev. Lett. 80 20) is analysed as a function of the ratio between the ion sound Larmor radius and the inertial skin depth. This cross shape structure is found to survive in the presence of weak dissipation. Further insight on the quasi-explosive behaviour of the magnetic island width as a function of time and on the spatial structure of the perturbed current density is provided. We confirm that the amount of reconnected flux becomes of order unity on the time scale of the inverse linear growth rate. Results in the collisionless limit are interpreted on the basis of the Hamiltonian properties of the adopted collisionless, 2D, fluid model. Thus, collisionless reconnection is a fast, non-steady-state process, fundamentally different from 2D resistive magnetic reconnection, of which the Sweet-Parker model is the classic paradigm.

The ‘Alienated’ Body: Slaves and Castas in the Hospital de San Bartolomé in Lima, 1680 to 1700

“A machine which does not serve the purpose of labor is useless. So a slave who becomes equated with a machine is useless when some component part no longer works.” (Karl Marx,Manuscripts, 459)“Verás de abanzada edadA muchos bozales negrosQue al público pensionandoEstán después que sirvieron.”For years after the 1687 earthquake had devastated much of Lima, various published sermons pondered the significance of the inauspicious event. One specific panegyric written in 1694 detailed the structural damage to the Hospital of San Bartolomé, founded in 1661 for “freed, disabled, ill or elderly blacks.” In the baroque literary style characteristic of the period, the author, Francisco de Vargas Machuca, described how the heroic viceroy Laso de Portocarrero, the Count of Monclova, “born like the sun for the remedy of all,” exercised his “divine charity” toward the poor of the Royal hospital, and “bore the weight of its ruins upon his own majestic shoulders to attend to the poor slaves and their hospital at his own expense.” According to the author, only Christ himself could have predicted that in 1694 the viceroy would refurbish the vestibule with exquisitely adorned doors, place “costly stones of the court” in the portal and replace the damaged cornices with more ornate ones in order to replicate a “hospital of heaven where the poor would enter.” After four months of intensive labor, the wards, in the shape of a Greek cross, were restored and the roofing and masonry work completed. Ample food, bedding and medicine once again provided adequate sustenance for the poor, infirm and elderly slaves and free castas in the hospital.

The shape of the Durrow cross

The shape of the Durrow Cross is made up of lines with measures and distances answerable entirely to ratios incorporating only 1, 2, and φ (the golden section). This paper gives a practical method for its construction, and discusses the scheme of its proportions.

Shapes of Early Sculptured Crosses of Ireland

This paper proposes the hypothesis that the shapes of early sculptured crosses of Ireland were devised by constructive geometry employing concepts and procedures like those used to devise the shapes of full-page illuminations in the early Insular Gospel manuscripts. Both kinds of design exhibit the same aesthetic rules: parsimony of ratios and commodulation of measures. That is to say, relations among the principal dimensions are linked by one or two elementary ratios inherent in simple geometrical figures, the circle and the cross. The hypothesis is developed by showing that stone cross shapes, similar to cross-page designs, can be replicated time and again by straightforward, catenulate construction with compass and straight-edge. There is no attempt to identify the source of the designs, or their possible symbolism, or their developmental sequence, for reasons that will be given. The focus, rather, is on the nature of the individual shapes--something never before articulated--and on how they can all be alike without any two being the same.

Interrelation of tuning characteristics to bar, cross and corner in striate neurons

Characteristics of responses and background activity, as well as of tuning to a single bar orientation and to cross or corner shape and orientation have been compared in one third (56/174) of neurons in the cat striate cortex. Shortening of the response latency to cross vs bar, to corner vs bar and to corner vs cross was revealed in most of the units studied. Direct correlation between the response and tuning characteristics for bar, cross and corner was revealed: units with better tuning to one type of stimulus were typically better tuned to the other types of stimuli. At the middle cortical depth (700–1 200 μm from the surface) we found a reliable improvement of response magnitude and latency, cross/bar response ratio and selectivity of tuning in comparison with more superficial and deeper layers. Although we could not find a direct correlation between characteristics of tuning to figures and the type of the receptive field (simple, complex or hypercomplex), our data pointed to a lower cross/bar ratio and selectivity of tuning in the units with small receptive fields. The functional implication of neuronal sensitivity to cross and corner and possible meaning of correlation between their functional characteristics are discussed.

Vibration of Plates Having Orthogonal Straight Edges with Clamped Boundaries

A domain decomposition procedure is employed to investigate the vibratory characteristics of plates having orthogonal straight edges with fully clamped boundary conditions. Three rectangular segments are used to construct an L-shaped plate element by enforcing continuities along the adjacent segments in displacement, slope, and higher derivatives. The strain and kinetic energies of each plate segment are coupled through the continuity matrices, resulting in a global energy functional for the entire plate domain. A governing eigenvalue equation is derived by minimizing the energy functional by following the Ritz procedure. A set of beam characteristic orthogonal polynomials is employed as the admissible displacement function for each plate segment. By virtue of symmetry in geometry, the basic L-shaped plate element is employed to construct plates of I and cross shapes, and vibration solutions of these plates are obtained via the domain decomposition procedure.

The neural inducer chordin and its downstream genes

Twisted gastrulation (Tsg) and chordin are secreted glycoproteins that function together as BMP (bone morphogenetic protein) antagonists to regulate BMP growth factor signalling. Chordin binds to BMPs, preventing them from interacting with their receptors and Tsg is known to strengthen this inhibitory complex. Tsg also acts as a BMP agonist by promoting cleavage of chordin by tolloid-family proteinases. Here we explore the structural mechanism through which Tsg exerts this dual activity. We have characterized the nanoscale structure of human Tsg using in-solution biomolecular analysis and show that Tsg is a globular monomer with a flattened cross shape. Tsg has a high proportion of N-linked glycans, in relation to its molecular weight, which supports a role in solubilising BMPs. Tsg binds with high affinity to the C-terminal region of chordin and was also able to inhibit BMP-7 signalling directly but did not have an effect on BMP-4 signalling. Although both Tsg and mammalian tolloid are involved in chordin cleavage, no interaction could be detected between them using surface plasmon resonance. Together these data suggest that Tsg functions as a BMP-agonist by inducing conformational change in chordin making it more susceptible to tolloid cleavage and as a BMP-antagonist either independently or via a chordin-mediated mechanism. Following single cleavage of chordin by tolloids, Tsg continues to strengthen the inhibitory complex, supporting a role for partially cleaved chordin in BMP regulation.

Seismic tomography survey under the La Gileppe Dam

Abstract A tomographic survey of 15 panels was performed under the La Gileppe dam (Belgium) to assess the degree of fracturing in the rock foundation which consists of steeply dipping beds of sandstone and shale. A particular aim of the study was to locate fracture zones likely to cause leakage under the dam. The panel dimensions range from 9 by 15 m (between 2 boreholes) to 60 by 40 m (between 4 boreholes). An explosive source and a 12 hydrophone string were used for the experiment. The data inversion was made with the Rai2D software of the L.C.P.C. (Laboratoire Central des Ponts et ChaussÉes), based on the SIRT algorithm with circular ray paths. The velocity values were influenced both by rock type and fracturing. The tomography method has been shown to image successfully low velocity fracture zones which could not have been determined by classical cross-hole tests. In some cases, tomograms showed cross shape images with a high velocity zone along the diagonals. These artefacts have been explained by numerical modelling as a result of the poor angular ray coverage of the section.