Basic Square Research Articles

Functional group changes of polyacrylonitrile fibres during their oxidative, carbonization and electrochemical treatment

A unique consideration is intended, concerning the creation of functional groups during the production of carbon fibres from polyacrylonitrile, i.e. oxidation/stabilization, carbonization/pyrolysis and electrochemical modification processes and their role for applications. Acrylic fibres of homopolymer PAN are subjected to thermo-oxidative treatment following a four-stage or a two-stage isothermal programme, and the resulting oxidized fibres are pyrolyzed up to 1000 °C for 30 min or they are flash-pyrolyzed at 1000 °C for 5 min, and the shrinkage and weight loss are determined. According to FTIR spectra, two indices were expressed to follow the dehydrogenations and cyclizations (nitrile groups) and the band intensity of carbonyl groups to follow the oxidation. The carbon fibres produced from the four-stage oxidation were examined using SEM/EDS. Based on SEM/EDS analysis, an oxygen content of approx. 8.7 at.% in the fibres is needed for the stabilization of the fibres during the oxidation by a four-stage treatment up to 300 °C. These carbon fibres were electrochemically modified by Cyclic Voltammetry in narrow and wide potential regions, using aqueous H2SO4. The electrochemical treatment of carbon fibres in the wide region leads to the introduction of an additional amount of oxygen of about 5 at.%, exhibiting also acidic and basic groups in adequate amount. The formation of oxygenous groups on carbon fibres during the three processes is indirectly followed by their ability to adsorb methylene blue or alizarin yellow dyes, based on the concept of “acid–base interaction”. Considering a model of a graphitic monolayer of a basic square that includes 9 rings, the O atoms introduced in this segment were estimated. Carbon fibre applications depend on the amount and type of oxygenous groups that can be targeted by selecting proper treatment conditions.

All-angle self-collimation in two-dimensional square array photonic crystals based on index contrast tailoring

A comprehensive study has been performed to achieve all-angle self-collimation in basic two-dimensional square array photonic crystals with cylindrical scatterers. Based on plane wave expansion and finite difference time domain analysis for both rod- and hole-type structures, we report on all-angle self-collimation (SC) in the first band of the structure, which results in loss suppression due to out-of-plane scatterings. A lower threshold for index contrast has been obtained to achieve all-angle SC, which offers more design flexibility regarding structural parameters. Furthermore, it has been shown that a minimum and maximum coupling efficiency enhancement of ∼40% and 80% can be achieved for the proposed structure, respectively, by introducing a row of scatterers with proper radius at the input and the output air/photonic crystal interfaces.

A fully implicit combined field scheme for freely vibrating square cylinders with sharp and rounded corners

We present a fully implicit combined field scheme based on Petrov–Galerkin formulation for fluid–body interaction problems. The motion of the fluid domain is accounted by an arbitrary Lagrangian–Eulerian (ALE) strategy. The combined field scheme is more efficient than conventional monolithic schemes as it decouples the computation of ALE mesh position from the fluid–body variables. The effect of corner rounding is studied in two-dimensions for stationary as well as freely vibrating square cylinders. The cylinder shapes considered are: square with sharp corners, circle and four intermediate rounded squares generated by varying a single rounding parameter. Rounding of the corners delays the primary separation originating from the cylinder base. The secondary separation, seen solely for the basic square along its lateral edges, initiates at a Reynolds number, Re between 95 and 100. Imposition of blockage lowers the critical Re marking the onset of secondary separation. For free vibrations without damping, Re range is 100–200 and mass ratio, m∗ of each cylinder is 10. The rounded cylinders undergo vortex-induced motion alone whereas motion of the basic square is vortex-induced at low Re and galloping at high Re. The flow is periodic for vortex-induced motion and quasi-periodic for galloping. The lower branch and desynchronization characterize the response of rounded cylinders. For the square cylinder, the components of response are the lower branch, desynchronization and galloping. Removal of the sharp corners of square cylinder drastically alters the flow and vibration characteristics.

Architectural Space Evolution of Railway Passenger Station

Architectural space evolution process and form of railway passenger station are studied in this paper. Firstly, architectural connotation evolution of railway passenger station is distinguished into three phases, namely railway-oriented passenger station, comprehensive transportation hub and urban complex. Then, architectural space evolution of three basic functional divisions, namely yard, station building and square, are studied. Furthermore, architecture space evolution of overall railway passenger station is divided into five stages with respective features of yard-dominated, yard-building-square plane layout, yard-building-square three-dimension layout, comprehensive transportation hub, and station complex. Finally, railway passenger station architectural space evolution in China is analyzed.

Spin-12J1-J2Heisenberg model on a cross-striped square lattice

Using the coupled cluster method (CCM) we study the full (zero-temperature) ground-state (GS) phase diagram of a spin-half ($s=1/2$) $J_{1}$-$J_{2}$ Heisenberg model on a cross-striped square lattice. Each site of the square lattice has 4 nearest-neighbour exchange bonds of strength $J_{1}$ and 2 next-nearest-neighbour (diagonal) bonds of strength $J_{2}$. The $J_{2}$ bonds are arranged so that the basic square plaquettes in alternating columns have either both or no $J_{2}$ bonds included. The classical ($s \rightarrow \infty$) version of the model has 4 collinear phases when $J_{1}$ and $J_{2}$ can take either sign. Three phases are antiferromagnetic (AFM), showing so-called N\'{e}el, double N\'{e}el and double columnar striped order respectively, while the fourth is ferromagnetic. For the quantum $s=1/2$ model we use the 3 classical AFM phases as CCM reference states, on top of which the multispin-flip configurations arising from quantum fluctuations are incorporated in a systematic truncation hierarchy. Calculations of the corresponding GS energy, magnetic order parameter and the susceptibilities of the states to various forms of valence-bond crystalline (VBC) order are thus carried out numerically to high orders of approximation and then extrapolated to the (exact) physical limit. We find that the $s=1/2$ model has 5 phases, which correspond to the four classical phases plus a new quantum phase with plaquette VBC order. The positions of the 5 quantum critical points are determined with high accuracy. While all 4 phase transitions in the classical model are first order, we find strong evidence that 3 of the 5 quantum phase transitions in the $s=1/2$ model are of continuous deconfined type.

ARTIFICIAL MAGNETIC CONDUCTORS ON WIDEBAND PATCH ANTENNA

The use of Artiflcial Magnetic Conductor (AMC) as a re∞ector in a printed antenna is known to improve the antenna's radiation characteristics. This work investigates the implementation of AMC as a re∞ector on a wideband planar monopole antenna. The investigation is conflned to a basic square unit cell of AMC with four possible variations. The AMC structures are constructed with square cells which have either similar square cells or a Perfect Electric Conductor (PEC) as the back plane. These same structures are also fabricated with vias. The impedance bandwidth, gain and power pattern are simulated and measured over the measured i10dB impedance bandwidth of 3GHz to 10GHz. The outcome of the investigation is that, for the antenna element and AMC structures considered in this study, a gain enhancement of up to 6dB can be achieved with the AMC structures. In addition, introduction of vias is observed not to in∞uence gain, though it improves cross-polarization levels by 3dB to 5dB for AMC constructed of squares backed by PEC.

Diffusion consistent calibrations for improved chemical imaging using nanoparticle enhanced optical sensors

A basic square root function was successfully used as a diffusion consistent calibration function that considers depletion mechanisms often occurring within optical chemical sensors. This continuous function improved image quality and simplified the calibration process. It may be a universal tool for the typical response function of reversible diffusion controlled sensing reactions. Further, we demonstrate that the gold nanoparticle interaction based ammonium fluorosensor is suitable for non-invasive high-resolution quantitative imaging of complex samples. The plasmon sensitized optical sensors were utilized as a bioanalytical tool for chemical imaging of natural degradation processes occurring in biological tissues. Analytical performance of the nanoparticle enhanced sensors confirmed superior sensitivity, reversibility, durability and overall image quality over non-doped sensing membranes. Although applied in a complex matrix of high potassium (major interferent) and very high sodium (interferent) excellent performance is achieved. The nanoparticle interaction/coextraction based sensing scheme utilized in this study is general and can be used for numerous ions, preferably combined with the diffusion consistent calibrations for superior analytical performance. A table with 44 commercially available ionophores is provided to guide potential users of this sensor configuration.

Design and Simulation of Miniaturized Multiband Fractal Antennas for Microwave Applications

Though there exists a variety of antennas for various purposes, the thirst for excelling in this area is ever increasing. This paper proposes a new miniaturized fractal antenna as a combination of Minkowski and Koch curves. The structure of the proposed antenna is the result of the modifications made with the basic fractal square and triangular curves. The design and simulation have been performed using IE3D, a full-wave electromagnetic simulator. It offers the best accuracy for planar microstrip antenna designs. The simulation with microstrip feed and coplanar waveguide feed systems and the results reveal that both the designs are extremely good in terms of multiband operations. Index Terms—Antenna, coplanar waveguide feed, fractal, IE3D, microstrip feed and miniaturization

Laparoscopic Intracorporeal Cinch Knots: Changing the Square Knot Paradigm

The ability to tie a reliably snug knot is a surgical sine qua non. Intracorporeal tying of a basic Square or Surgeon's knot using two instruments presents significant challenges to even the competent laparoscopist and is a skill requiring training and dexterity. The cinch knot, extracorporeally tied and slid to the tissue with a knot pusher, is perhaps technically easier but for its requirement of long suture length has limitations to its surgical application. The purpose of this video is to demonstrate a novel technique – employing basic laparoscopic instrument motions – for tying cinch knots entirely intracorporeally as an easily learned alternative to existing knot tying techniques. We further identify the particular suitability of this technique for single incision laparoscopic procedures.

Self-organization of developing embryo using scale-invariant approach

BackgroundSelf-organization is a fundamental feature of living organisms at all hierarchical levels from molecule to organ. It has also been documented in developing embryos.MethodsIn this study, a scale-invariant power law (SIPL) method has been used to study self-organization in developing embryos. The SIPL coefficient was calculated using a centro-axial skew symmetrical matrix (CSSM) generated by entering the components of the Cartesian coordinates; for each component, one CSSM was generated. A basic square matrix (BSM) was constructed and the determinant was calculated in order to estimate the SIPL coefficient. This was applied to developing C. elegans during early stages of embryogenesis. The power law property of the method was evaluated using the straight line and Koch curve and the results were consistent with fractal dimensions (fd). Diffusion-limited aggregation (DLA) was used to validate the SIPL method.Results and conclusionThe fractal dimensions of both the straight line and Koch curve showed consistency with the SIPL coefficients, which indicated the power law behavior of the SIPL method. The results showed that the ABp sublineage had a higher SIPL coefficient than EMS, indicating that ABp is more organized than EMS. The fd determined using DLA was higher in ABp than in EMS and its value was consistent with type 1 cluster formation, while that in EMS was consistent with type 2.

Visual simulation of retinal images through microstructures

The space distribution of photoreceptors is a main topic in artificial retina design procedures. A fundamental question is how different retina architectures reproduce the same image and which their properties are? This paper presents a new method to emulate the visual response of biological or artificial retinas. The proposed method can predict the vision output image of any retina with known photoreceptors distribution. A simple method is proposed that considers only two parameters to simulate the output image of any retina architecture: the distribution of the photoreceptors in the retina and the estimated light response of its photoreceptors. The distribution of the photoreceptors along the retina is modeled by geometrical figures that let define a set of many different outer trajectories. The paper discusses also a new method to organize the layout of any retinal architecture design using a set of basic square vertical phototransistors cells according with a previously defined photoreceptors distribution. The Lena image is used to predict the degree of resolution at the central area and how it is faded towards the periphery.

A new simple square root option pricing model

This study derives a simple square root option pricing model using a general equilibrium approach in an economy where the representative agent has a generalized logarithmic utility function. Our option pricing formulae, like the Black–Scholes model, do not depend on the preference parameters of the utility function of the representative agent. Although the Black–Scholes model introduces limited liability in asset prices by assuming that the logarithm of the stock price has a normal distribution, our basic square root option pricing model introduces limited liability by assuming that the square root of the stock price has a normal distribution. The empirical tests on the S&P 500 index options market show that our model has smaller fitting errors than the Black–Scholes model, and that it generates volatility skews with similar shapes to those observed in the marketplace. © 2010 Wiley Periodicals, Inc. Jrl Fut Mark

QSPR study of partition coefficient (Ko/w) of some organic compounds using radial basic function-partial least square (RBF-PLS)

In this work, we introduce a new method ability radial basic function-partial least square (RBF-PLS) with high accuracy and precision in QSPR studies. Three quantitative structure-propertty relationship (QSPR) methods have been compared for the prediction of n-octanol-water partition coefficients (Ko/w) of some organic compounds. The multiple linear regressions (MLR), partial least square (PLS) and radial basis function-partial least squares (RBF-PLS) models were employed to construct linear and nonlinear models to predict of Ko/w. The theoretical descriptors that calculated by Dragon and Gaussian 98 were explored by stepwise regressions, encoding different aspects of the topological, geometrical and electronic molecular structures. The root means square error of prediction (RMSEP) for training and prediction sets by MLR, PLS and RBF-PLS models were 0.4022, 0.4128, 0.3050, 0.3564, 0.0364 and 0.0533, respectively. Also, the relative standard error of prediction (RSEP) for training and prediction sets by MLR, PLS and RBF-PLS models were 13.24, 13.60, 10.04, 11.74, 1.197 and 1.757 respectively. The resultant data explained that RBF-PLS produced better results than PLS and MLR.

Polish Contempt

Page 8 American Book Review Polish Contempt Jaimy Gordon The small world of this novel—a public square of a nameless city in a nameless European country , circumnavigated by a streetcar line that goes nowhere—is summoned into being, in a voice curdling with exasperation, by a narrator who is worried about her bill. She is being woefully overcharged by a host of shady “master craftsmen and apprentices” for the work of building this rickety scene, which barely manages to pass for a basic city square, with views into the distance along its edges that turn out to be plyboard panels, painted and patched, some of the patches missing or upside down. Its human population is likewise the work of a dispirited and negligent craftsman: the tailor. “First will come the costumes”—so reads the opening sentence of Flaw. The tailor will supply them all wholesale. He’ll select the designs off-handedly and, with a few snips of the shears, will summon to life a predictable repertoire of gestures. See—scraps of fabric and thread in a circle of light, while all around is darkness. Out of the turmoil will emerge a fold of cloth, the germ of a tuck fastened with a pin. The tuck will create everything else. So we have seen them all before, these characters, in a certain kind of European novel, or a certain way of thinking about the world. We know their outer costumes and their inner lives, their sense of being overburdened and underpaid, worth more than the little credit they get. The querulous note is ubiquitous in Flaw, in the voice of its narrator, among its mysterious workmen, and now inside the characters. Because the materials are inferior, because the workers bear a grudge, what can we expect but this hierarchy of stereotypes, the harrumphing notary and his nervous wife, their maid whose bottom is regularly pinched, the bumbling policeman, the lowly washerwoman , the waiter in the one café, the law student.A couple of airmen are misdirected to the square and, when an unspecified political “catastrophe” occurs offstage, the one in a general’s uniform takes charge. Character is costume, the narrator explains, but costumes , too, are overpriced and never really fit, and the tailor, like the master craftsmen and apprentices, has learned to finish his flawed work in a hurry, with an attitude somewhere between malice and disgust. This is the flaw for which Flaw is named, “the flaw of contempt.” How can anything ever be made better under these conditions? “And what if I’m the one who placed the order?” the narrator asks. “What if I can barely afford the whole thing?” It goes without saying that all this carries a price—the pavement, the tracks, the streetcar. Every brick and every roof tile has to be paid for…. I provide work for painters, upholsterers, and decorators; for mechanics and lighting specialists; for swaggering types with cigarettes permanently stuck in the corners of their mouths; for master craftsmen and apprentices in crumpled overalls who value their pay and despise their work; for devout servants of all their own weaknesses . Were it not for the odious job it is their lot to perform, were it not for the rule in their pocket and the scuffed bandages on their fingers, they would have nothing but the despair that wrenches them from sleep at dawn. They are as bound to me as I am bound to them. I pay the advances and swallow without a murmur both smaller and larger chicaneries. I do not question the bills when they include props already long since paid for and used, or repainted backdrops in which a hole from a previous hook gives the game away at once. How painful it is to see plainly all the shortcomings of this world, its shabbiness and its inability to actually exist. Into this makeshift world comes “catastrophe”— the word is sown freely through Flaw—nameless, featureless catastrophe, which happens elsewhere, but overtakes the square in the form of tramcar upon tramcar full of refugees. How do we know they are refugees? “[B]ecause of the cap with the earflaps and the thick winter coat, which...

Iterative least square phase-measuring method that tolerates extended finite bandwidth illumination

Iterative least square phase-measuring techniques address the phase-shifting interferometry issue of sensitivity to vibrations and scanner nonlinearity. In these techniques the wavefront phase and phase steps are determined simultaneously from a single set of phase-shifted fringe frames where the phase shift does not need to have a nominal value or be a priori precisely known. This method is commonly used in laser interferometers in which the contrast of fringes is constant between frames and across the field. We present step-by-step modifications to the basic iterative least square method. These modifications allow for vibration insensitive measurements in an interferometric system in which fringe contrast varies across a single frame, as well as from frame to frame, due to the limited bandwidth light source and the nonzero numerical aperture of the objective. We demonstrate the efficiency of the new algorithm with experimental data, and we analyze theoretically the degree of contrast variation that this new algorithm can tolerate.

Considerations related to the standardization of methods for the qualification of free field test environments.

The methods for qualification of acoustic free field environments, such as anechoic and hemi‐anechoic chambers, have historically been defined in Annexes to the basic sound power standards, such as ISO 3745. However, free field test environments are used for many applications other than just sound power level determination, such as basic acoustic research, audio test, and hearing sciences. There currently are no general standards for free field qualification that addresses the unique needs of these test methods. Although the basic inverse square law qualification method is very straightforward theoretically, there are a number of practical considerations that can make this qualification method technically complex, logistically difficult, and expensive to implement. Industry standards must strike the right balance between the technical needs of the test methods and the costs associated with chamber qualification, particularly in the chamber vendor/chamber customer business environment. This paper will address some of the practical issues associated with the current inverse square law qualification method and the work of ISO Technical Committee 43, Working Group 8 that is currently in the process of developing a more general and improved document for the qualification of free field environments using this method.

Synthesis and vibrational spectra of copper(II) and erbium(III) complexes with 2-[2′-(oxymethyldiphenylphosphinyl)phenyldiazenyl]-4-tert-butylphenol (HL) [CuL2] · 2H2O and Er(NO3)2 · 2 HL · 2H2O. Crystal structure of [CuL2] · 2H2O

The syntheses of the complex copper salt CuL2 · 2H2O (I) and the erbium nitrate complex Er(NO3)3 · 2HL · 2H2O (II) (HL is 2-[2′-(oxymethyldiphenylphosphinyl)phenyldiazenyl]-4-tert-butylphenol) have been described. Basic vibrational frequencies in the IR spectra of I and II have been interpreted. The crystal structure of I has been determined by X-ray crystallography: the crystals are monoclinic, a = 15.157(3) A, b = 17.080(2) A, c = 22.451(9) A, β = 106.09(3)°, V = 5584(3) A3, Z = 4, space group C2/c, R = 0.0546 (for 1152 reflections with I > 2σ(I)). The coordination polyhedron of the copper atom (symmetry C 2) can be described as a symmetrically elongated square bipyramid (4+2). The basic square of the Cu polyhedron is formed by the oxygen atom of the substituted phenol and one of the nitrogen atoms of the azo group of each of the two deprotonated ligands L− (Cu-N, 1.969(6) A; Cu-O, 1.899(5) A). The angles between the opposite O and N atoms are 157.6°, and the other equatorial angles are in the range 90.6°–95.9°. The axial positions are occupied by the anisole O(2) and O(2A) atoms (Cu-O, 2.737(6) A, the O(2)Cu(1)O(2A) angle, 132.3°). In the crystal of I, complex molecules and water molecules of crystallization are combined by a system of hydrogen bonds. IR spectra show that, in complex II, as distinct from compound I, the HL ligand is coordinated to the erbium atom through the phosphoryl oxygen atom.

Square stent: a new self-expandable endoluminal device and its applications.

The square stent is a new, simply constructed, self-expanding device that has recently been described. Compared with other stents, the square stent has a minimal amount of metal and thus requires a smaller-diameter catheter for introduction. Despite the small amount of metal present, the square stent has adequate expansile force. We have been evaluating the square stent for various interventional applications. In addition to the basic square stent, combinations of square stents and coverings for square stents were developed and evaluated to expand its uses and indications. One of the coverings tested is a new biomaterial: small intestinal submucosa (SIS). This paper will discuss the various applications of the square stent, which include a retrievable inferior vena cava filter, vascular occluder, graft adapter, and venous and aortic valves. In addition, we will review the important properties of SIS as a covering for the square stent.

A semi-analytical solution for vibration of rectangular plates with abrupt thickness variation

A semi-analytical analysis of free vibration of plates with cross-sectional discontinuities due to abrupt changes in thickness is presented. A basic square element divided into suitable subdomains dependent upon the positions of these abrupt changes is used as the basic building element. Admissible functions that satisfy the essential or geometric boundary conditions are used to define the transverse deflection of each subdomain. Continuities in the displacement, slope, moment and higher derivatives between adjacent subdomains are enforced at the interconnecting edges. The resulting global energy functional from the proper assembly of the coupled strain and kinetic energy contributions of each subdomain is then minimized via the Ritz procedure to extract the frequencies and mode shapes. Contour plots of a range of new mode shapes are presented for the enhancement of understanding the dynamic behavior of this class of plates.

明治期地形図からメッシュ人口データ推定

This paper discusses possibility of the estimation of the past population distribution pattern from old topographical maps. This estimation aims to make Basic Grid Square Spaces (BGSS) population distribution data that can be available in GIS. In the past, no reliable statistical material exists except topographical maps published in many regions, which are showing villages clearly. An efficient method of the estimation of the past population pattern from the maps will provide the way to analyze long time-space population movement in detail.We tried to estimate population distribution in the Meiji-Era at the selected area of East-Biwako area (Koto Plain) in Shiga-Prefecture, firstly by point sampling of buildings drawn in the maps, then using GIS (ArcView). The result shows that it is possible to estimate population distribution at that time with pretty accuracy and adapt it to other time and other regions.