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This work applied the AutoLab 2000 test system to investigate three kinds of core samples of sandstone from the Yanchang oilfield that were cut parallel and perpendicular to the bedding planes (named H and V, respectively), and obtained accurate P- and S-wave velocities, and wave velocity anisotropy data at pressures up to 180 MPa in dry, water- and oil-saturated states for those sandstone. The results show the wave velocities VP, VSH and VSV for all H and V samples cut from three kinds of samples of sandstone Y1, Y2 and Y3 change basically logarithmically with increasing confining pressure p, and for all VP, the slopes of the oil-saturated curves are greater than that of the corresponding water-saturated curves. For all H samples, in dry, water- and oil-saturated conditions, the VP and VSH and VSV are larger than the corresponding ones for V samples. For two kinds of sandstones Y1 and Y2, the wave velocity anisotropy parameters e, γ and ζ change exponentially or in a quadratic curve with increasing confining pressure, and Y2 has a greater correlation coefficient of anisotropy parameters than Y1, but there is no wave velocities anisotropy in Y3. In addition, in dry, water- and oil-saturated conditions the relationships between e, γ and p or γ, ζ and p are quite distinct from each other, that is, the anisotropy factors e, γ and ζ of Y1 and Y2 exhibit a clear correlation with pressure and the fluid property, and e and γ in oil-saturated condition are larger than that in the corresponding water-saturated condition at the experimental pressure. The experimental results can provide an important basis for the interpretation of seismic data, identifying oil and water zones and comparing with well log data in the study area.

Fabrication of capillaries with tapered tips is an important technique that is required in many analytical chemistry areas, such as ESI-MS, CE, electrochemical analysis, and microinjection. This paper describes a simple and effective grinding-based fabrication method for capillaries with tapered tips. A novel grinding mode utilizing the combination of rotation and precession of an elastic capillary was developed, which significantly improved the controllability to the grinding process as well as the capillary tip shape. The capillary was fabricated by fixing it in an electric drill installed perpendicularly, and grind the capillary tip rotated around its own axis as well as the drill axis on sandpapers. Compared with conventional fabrication techniques for capillary tips, the present method is easy to control the capillary tip shape in routine laboratories without the requirement of expensive equipments or poisonous reagent (e.g. hydrofluoric acid (HF) solution). Various capillaries with different tip diameters and tip taper angles could be fabricated using the present method with good controllability and reproducibility. These capillaries were applied in high-speed CE and ESI-MS analysis to demonstrate the feasibility and potential of this fabrication method.

Summary This paper introduces a double-image multiple-beam Fizeau fringes system. The introduced system can dynamically determine the variations of the refractive indices for both parallel and perpendicular polarization simultaneously. This is achieved by the simultaneous capturing of two multiple-beam interference patterns during the mechanical processing of isotactic polypropylene fibre. This parallel determination of the refractive indices of both polarization directions allowed us to determine the full-field distribution of the stress vector, S. To accomplish this, a mathematical model was deduced to calculate the components of the stress vector, S, i.e. parallel stress component, S1, and perpendicular stress component, S2. Double-image Fizeau fringes system and the deduced mathematical model were used to investigate the variation of the refractive index and stress components of the fibre during the stretching process and propagation of necked regions.

Recurrence rate of hiatal hernia can be reduced with prosthetic mesh repair; however, type and shape of the mesh are still a matter of controversy. The purpose of this study was to investigate the biomechanical properties of four conventional meshes: pure polypropylene mesh (PP-P), polypropylene/poliglecaprone mesh (PP-U), polyvinylidenefluoride/polypropylene mesh (PVDF-I), and pure polyvinylidenefluoride mesh (PVDF-S). Meshes were tested either in warp direction (parallel to production direction) or perpendicular to the warp direction. A Zwick testing machine was used to measure elasticity and effective porosity of the textile probes. Stretching of the meshes in warp direction required forces that were up to 85-fold higher than the same elongation in perpendicular direction. Stretch stress led to loss of effective porosity in most meshes, except for PVDF-S. Biomechanical impact of the mesh was additionally evaluated in a hiatal hernia model. The different meshes were used either as rectangular patches or as circular meshes. Circular meshes led to a significant reinforcement of the hiatus, largely unaffected by the orientation of the warp fibers. In contrast, rectangular meshes provided a significant reinforcement only when warp fibers ran perpendicular to the crura. Anisotropic elasticity of prosthetic meshes should therefore be considered in hiatal closure with rectangular patches.

Summary In near-fault regions, forward directivity causes long-period pulse-like motions with high amplitude and short duration perpendicular to the fault surface. Pulse-like motions have important roles in forming the distribution of damages over the structure height. Recent studies indicate that the number of spans influences the demand distribution over the moment frame's height. Considering the destruction of the buildings near causative fault in Bam earthquake, Iran (2003) demonstrates that most damages are concentrated in the ground floor of moment frames. Hence, in this study, forward directivity effect on vulnerability distribution of steel moment-resisting frames with a few number of spans has been studied by nonlinear dynamic analysis of five structural models with different heights under 20 earthquake records. Related to frames height, results showed that 70% to 90% of forward directivity effects are accumulated in lower one-third or half of model's height. Also, in near field of fault, growing rate of ductility demand at lower parts of model's height is two times higher than that of far-fault regions. In addition, it was observed that ductility capacity in lower half of low-rise or one-third of high-rise models has a key role in stability of moment frames under near-fault pulse-like motions. Copyright © 2014 John Wiley & Sons, Ltd.

The purpose of this study is to find the uncertainties in the reconstruction of MR compatible ring‐tandem intracavitary applicators of high‐dose rate image‐based brachytherapy treatment planning using rigid registration of 3D MR and CT image fusion. Tandem and ring reconstruction in MR image based brachytherapy planning was done using rigid registration of CT and MR applicator geometries. Verifications of registration for applicator fusion were performed in six verification steps at three different sites of tandem ring applicator set. The first site consists of three errors at the level of ring plane in (1) cranio–caudal shift (Cranial Shift) of ring plane along tandem axis, (2) antero–posterior shift (AP Shift) perpendicular to tandem axis on the plane containing the tandem, and (3) lateral shift (Lat Shift) perpendicular to the plane containing the tandem at the level of ring plane. The other two sites are the verifications at the tip of tandem and neck of the ring. The verification at the tip of tandem consists of two errors in (1) antero–posterior shift (AP Shift) perpendicular to tandem axis on the plane containing the tandem, and (2) lateral shift (Lat Shift) perpendicular to the plane containing the tandem. The third site of verification at the neck of the ring is the error due to the rotation of ring about tandem axis. The impact of translational errors from −5 mm to 5 mm in the step of 1 mm along x‐, y‐, and z‐axis and three rotational errors about these axes from −19.1° to 19.1° in the step of 3.28° on dose‐volume histogram parameters (D2cc,D1cc,D0.1cc, and D5cc of bladder, rectum, and sigmoid, and D90 and D98 of HRCTV were also analyzed. Maximum registration errors along cranio–caudal direction was 2.2 mm (1 case), whereas the errors of 31 out of 34 cases of registration were found within 1.5 mm, and those of two cases were less than 2 mm but greater than 1.5 mm. Maximum rotational error of ring about tandem axis was 3.15° (1.1 mm). In other direction and different sites of the ring applicator set, the errors were within 1.5 mm. The impacts of registration errors on DVH parameters of bladder, rectum, and sigmoid were very sensitive to antero–posterior shift. Cranio‐caudal errors of registration also largely affected the rectum DVH parameters. Largest change of 17.95% per mm and 20.65% per mm in all the DVH parameters of all OARs and HRCTV were observed for ϕ and Ψ rotational errors as compare to other translational and rotational errors. Catheter reconstruction in MR image using rigid registration of applicator geometries of CT and MR images is a feasible technique for MR image‐based intracavitary brachytherapy planning. The applicator registration using the contours of tandem and neck of the ring of CT and MR images decreased the rotational error about tandem axis. Verification of CT MR image fusion using applicator registration which consists of six steps of verification at three different sites in ring applicator set can report all the errors due to translation and rotational shift along θ,ϕ, and Ψ. ϕ and Ψ rotational errors, which produced potential changes in DVH parameters, can be tackled using AP Shift and Lat Shift at the tip of tandem. The maximum shift was still found along the tandem axis in this technique. PACS number: 87.55.km

The impact of dislocations on surface topology as well as on quantum well emission in c-plane, semipolar, and nonpolar InGaN/GaN heterostructures is being analyzed by micro-photoluminescence and white-light-interferometry. V-pits with (101) and (10) side facets are identified in a (102) semipolar heterostructure. Hillocks formed by spiral growth around screw dislocations change from hexagonal to triangular to rectangular shape in polar, semipolar, and nonpolar heterostructures, respectively, reflecting the symmetry of the individual surface. The emission in semipolar quantum wells, grown homoepitaxially on bulk GaN substrates, show dark stripes aligned with misfit dislocations. For (112) and (201) orientation, these dark stripes are perpendicular and parallel, respectively, to surface striation.

A biologically inspired, multilayer laminate structural design is deployed into nanocomposite films of graphene oxide-poly(methyl methacrylate) (GO-PMMA). The resulting multilayer GO-PMMA films show greatly enhanced mechanical properties compared to pure-graphene-oxide films, with up to 100% increases in stiffness and strength when optimized. Notably, a new morphology is observed at fracture surfaces: whereas pure-graphene-oxide films show clean fracture surfaces consistent with crack initiation and propagation perpendicular to the applied tensile load, the GO-PMMA multilayer laminates show terracing consistent with crack stopping and deflection mechanisms. As a consequence, these macroscopic GO-PMMA films become defect-tolerant and can maintain their tensile strengths as their sample volumes increase. Linear elastic fracture analysis supports these observations by showing that the stiffness modulation introduced by including PMMA layers within a graphene oxide film can act to shield or deflect cracks, thereby delaying failure and allowing the material to access more of its inherent strength. Together, these data clearly demonstrate that desirable defect-tolerant traits of structural biomaterials can indeed be incorporated into graphene- oxide-based nanocomposites.

Lab ultrasonic measurements to metamorphic kinds of coal reveal the relation between the maximum vitrinite reflectance and ultrasonic quality factor. And then the relations between ultrasonic velocities and quality factors, including the anisotropic characteristics of quality factors are analyzed. The results show that there are good linear correlations between the maximum vitrinite reflectance and P- and S-wave quality factors, between velocities in direction perpendicular to seams and quality factors, and between the P- wave quality and S-wave's quality factors in direction vertical to seams. Moreover, there are stronger anisotropies in seismic quality factors than velocities. Comparison of the measured S-wave Q values with estimated values, based on a theoretical formula, indicates an only 7.2% relative error in this method. It proves that this theoretical formula can be applied to attenuation compensation of the converted shear wave in processing of multi-component seismic data.

A numerical simulation of heat conduction in a grain aggregate is carried out to determine the packing fraction (the spatial fraction occupied by grains or 1-porosity) dependence of the thermal conductivity of the aggregate. Arrangements of grains are given by random ballistic deposition. It is found that the packing fraction dependence is well approximated by an exponential function. The number of contacts between grains is the crucial quantity in the conduction, and its packing fraction dependence is exponential. Heat conduction is found to be anisotropic, where the conduction along the deposition direction is more efficient than that perpendicular to the deposition direction.

Four new layered pentaborates Rb4Ba2.5B20O34Br, Rb2Ba4B20O34Br2, Rb4Ba2.5B20O34Cl, and KBaB5O9 have been successfully synthesized via a high-temperature solution method; the former three are the first series of compounds reported in the Rb-Ba-B-O-X (X = halogen) system. Interestingly, the structures of the above compounds are composed of the same [B5O11]7– fundamental building block (FBB), which could be further linked to form 2∞[B10O17]4– double layers for the former three compounds and 2∞[B5O9]3– single layers for the last one. The structure comparisons among all the available anhydrous pentaborates reveal that the structures of the anionic framework are affected by the relationship between the orientation of [B5O11]7– FBB axes and the layer plane (parallel or perpendicular), which will produce the different number of terminal O atoms in the initial pentaborate blocks. The viewpoints give us a feasible way to investigate the layered structures and expand the structural diversity of borates. Furthermore,...

From Fe3Si/FeSi2 artificial lattices, wherein Fe3Si layers are partially epitaxially grown from the first layer on Si(111) up to the top layer across the FeSi2 layers with the same orientation relationship as that in the first layer, current-perpendicular-to-plane (CPP) structures that partially contain current-in-to-plane (CIP) structural portions were fabricated by a mask method. It was confirmed that the antiparallel alignment of magnetization at a zero magnetic field due to antiferromagnetic interlayer coupling is changed to parallel alignment with the applied magnetic field by polarized neutron reflectometry. The MR ratio was comparable to that of CIP structural films. It might be because a current should predominantly flow in the CIP portion since the CIP structural portion is dimensionally so large as compared with that of the CPP portion. (© 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)

We report on the fabrication and electrical characterization of etched graphene single electron transistors (SETs) of various sizes on hexagonal boron nitride (hBN) in high magnetic fields. The electronic transport measurements show a slight improvement compared to graphene SETs on SiO2. In particular, SETs on hBN are more stable under the influence of perpendicular magnetic fields up to 9 T in contrast to measurements reported on SETs on SiO2. This result indicates a reduced surface disorder potential in SETs on hBN, which might be an important step toward clean and more controllable graphene quantum dots (QDs).

Vertical arrays of anisotropic particles are desired for many applications including solar cells, battery electrodes, and lasers. Partially etched nano­wires (PENs) are hybrid silica nanotube/nanowires with partial metallic cores. These particles spontaneously form vertical arrays in which on average 70% of the particles are oriented perpendicular to the underlying substrate. Here, we perform PEN self-assembly on lithographically prepared substrates patterned with square microwells having dimensions comparable to the length of the particles. Particle self-assembly is observed both in the microwells and on the intervening surfaces. PENs both directly deposit into a well and diffuse across the surface between microwells until falling into a well. Assembly occurs as the local concentration of PENs in a well increases by these two mechanisms. Microwells provide a way to control array location on a surface and improve standing percentages up to 100% when the edge dimensions are decreased to a size approximately equal to the nanowire length. Micro­wells also protect against array disruption during sample drying.

Purpose To describe contact, thickness, density, and orientation of connective tissue fibers around healing abutments of different geometries by means of a new method using coordinates. Materials and Methods Following the bilateral extraction of mandibular premolars (P2, P3, and P4) from six fox hound dogs and a 2-month healing period, 36 titanium implants were inserted, onto which two groups of healing abutments of different geometry were screwed: Group A (concave abutments) and Group B (wider healing abutment). After 3 months the animals were sacrificed and samples extracted containing each implant and surrounding soft and hard tissues. Histological analysis was performed without decalcifying the samples by means of circularly polarized light under optical microscope and a system of vertical and horizontal coordinates across all the connective tissue in an area delimited by the implant/abutment, epithelium, and bone tissue. Results In no case had the connective tissue formed a connection to the healing abutment/implant in the internal zone; a space of 35 ± 10 μm separated the connective tissue fibers from the healing abutment surface. The total thickness of connective tissue in the horizontal direction was significantly greater in the medial zone in Group B than in Group A (p

A nickel-nickel-bonded complex, [{Ni(μ-L(.-))}2] (1; L=[(2,6-iPr2C6H3)NC(Me)]2), was synthesized from reduction of the LNiBr2 precursor by sodium metal. Further controllable reduction of 1 with 1.0, 2.0 and 3.0 equiv of Na, respectively, afforded the singly, doubly, and triply reduced compounds [Na(DME)3]·[{Ni(μ-L(.-))}2] (2; DME=1,2-dimethoxyethane), [Na(Et2O)]Na[(L(.-))Ni-NiL(2-)] (3), and [Na(Et2O)]2Na[L(2-)Ni-NiL(2-)] (4). Here L represents the neutral ligand, L(.-) denotes its radical monoanion, and L(2-) is the dianion. All of the four compounds feature a short Ni-Ni bond from 2.2957(6) to 2.4649(8) Å. Interestingly, they display two different structures: the perpendicular (1 and 2) and the coaxial (3 and 4) structure, in which the metal-metal bond axis is perpendicular to or collinear with the axes of the α-diimine ligands, respectively. The electronic structures, Ni-Ni bonding nature, and energetic comparisons of the two structure types were investigated by DFT computations.

We study the dynamics of a spheroidal galaxy with a gravitating polar ring whose plane is perpendicular to the equator. We consider this problem in the tidal approximation and derive a closed set of equations, which we reduce to a seventh-order differential equation. We solve the resulting equation to find that perturbations from the polar ring deform the spheroid into a non-stationary rotating triaxial ellipsoid with linear internal velocity field. (© 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)

Block copolymer thin films are highly versatile and accessible materials capable of producing nanofeatures in the size regime of a few to hundreds of nanometers by a simple spin-coating-and-anneal process. Unfortunately, this simple protocol usually leads to parallel microdomains, which limits the applicability of such nanofeatures. A great deal of effort has been put into achieving perpendicular microdomains, but those that incorporate thermal annealing are arguably the most practical and reproducible in the lab and industry. This review discusses the recent ongoing efforts on various thermal approaches to achieving perpendicular microdomains in order to provide the readers with a toolbox to work with.

For determination of film thickness with a reflectometer, the incident light is usually perpendicular to the film. Often, however, measuring heads are used that keep the aperture of the optical fiber constant or even microscopes are used to increase the lateral resolution in film thickness determination. Analogous to a fixed angle of incidence α the thickness determination is influenced in both cases. In contrast to a fixed angle now all angles between 0° and the aperture angle αapt are present for a measuring head or a microscope objective. We demonstrate here, how the aperture of the measuring head affects the thickness determination and give a quantitative estimation of the influence by assigning an effective angle of incidence αeff to a measuring head with aperture angle αapt.

The end-to-side anastomosis is frequently used in microvascular free flap transfer, but detailed rheological analyses are not available. The purpose of this study was to introduce a new modified end-to-side (Opened End-to-Side, OES-) technique and compare the resulting flow pattern to a conventional technique. The new technique was based on a bi-triangulated preparation of the branching-vessel end, resulting in a "fish-mouthed" opening. We performed two different types of end-to-side anastomoses in forty pig coronary arteries and produced one elastic, true-to-scale silicone rubber model of each anastomosis. Then we installed the transparent models in a circulatory experimental setup that simulated the physiological human blood flow. Flow velocity was measured with the one-component Laser-Doppler-Anemometer system, recording flow axial and perpendicular to the model at four defined cross-sections for seven heart cycles in each model. Maximal and minimal axial velocities ranged in the conventional model between 0.269 and -0.122 m/s and in the experimental model between 0.313 and -0.153 m/s. A less disturbed flow velocity distribution was seen in the experimental model distal to the anastomosis. The OES-technique showed superior flow profiles distal to the anastomosis with minor tendencies of flow separation and represents a new alternative for end-to-side anastomosis.

A variant of the auxetic helical yarn is explored herein by means of sewing an inextensible thin cord through an elastic fat cord, in a triangular pattern, to form a semi-auxetic yarn. When stretched in the longitudinal direction, the semi-auxetic yarn exhibits conventional and auxetic behavior in the plane perpendicular and parallel, respectively, to the plane which the inextensible thin cord lies on. A simplified model is developed herein to describe the effective Poisson's ratio of the yarn in the conventional and auxetic planes in terms of the initial half angle of the thin cord and the Poisson's ratio of the fat cord. Results show that the Poisson's ratio of the yarn in the auxetic plane decreases and increases with the initial half angle of the thin cord and the Poisson's ratio of the fat cord, respectively, while the Poisson's ratio of the yarn in the conventional plane increases with both parameters. In addition, the dominant parameters for the yarn in the auxetic and conventional planes are the initial half angle of the thin cord and the Poisson's ratio of the fat cord, respectively. Finally, other types of semi-auxetic yarns in the same category are proposed with suggested ways of producing them.

We have extended a previous model for calculating the effects of dislocations on the characteristics of a Si solar cell to include the effects of front and back surface recombination. This improved dislocation model uses Green's function approach to solve the three-dimensional continuity equation of the minority carriers with suitable boundary conditions corresponding to surface recombination at the n and p sides. The dislocations are considered to be localized lines, extending perpendicular to the front and back surfaces of the cell and having a recombination velocity. We discuss effect of several parameters such as bulk dislocation density, minority carrier diffusion length in p and n regions on the J-V characteristics, and spectral response of the cell. It is shown that these results agree well with previously published, experimental data. Copyright © 2013 John Wiley & Sons, Ltd.

In this study, torsionally irregular single-story and multistory structures under the effect of near-fault ground motion excitation were controlled by active tendons. Near-fault ground motions contain two impulsive characters. These impulsive characters are the directivity effect perpendicular to fault and the flint step parallel to fault. The structural models were simulated under bidirectional earthquake records superimposed with impulsive motions to examine the response of active control under near-fault effects. Also, the structures were analyzed only under the effect of bidirectional impulsive pulses. The control signals were obtained by Proportional–Integral–Derivative (PID) type controllers and the parameters of the controllers were obtained by using a numerical algorithm depending on time domain analyses. Time delay effect was also considered for active control system. Different cases of orientation of active tendons were examined and the results of the single-story structure were compared with another control strategy using frequency domain responses in the optimization process. As a conclusion, the control concept is significantly effective on reducing maximum responses in translational and rotational directions and obtaining a steady-state response.

SiC fiber-bonded ceramics, SA-Tyrannohex®, (SA-THX) with perpendicular and parallel fiber orientations were brazed using Ag-, Ni- and Pd-base brazes, and four Si–X (X: Ti, Cr, Y, Ta) eutectics. Outcomes were variable, ranging from bonded joints through partially bonded to un-bonded joints. Prominent Ti- and Si-rich interfaces developed with Cusil-ABA, Ticusil, and Copper-ABA and Ni- and Si-rich layers with MBF-20. Stress rupture tests at 650 and 750°C on Cusil-ABA-bonded joints revealed a temperature-dependent behavior for the perpendicular joints but not for the parallel joints with failure occurring at brazed interface. Higher-use temperatures can be targeted with eutectic Si–Ti and Si–Cr alloys.

Thin binary blends of poly(styrene-b-methyl methacrylate) (PS-PMMA) block copolymers in films where the lamellar thickness of one domain is controlled while preserving the thickness of the other domain were demonstrated without microphase separation. One of the block copolymers used here was short and symmetric, and the other was long and asymmetric; the molecular weights of the PMMA block chains in the constituents were similar. A random copolymer brush was introduced and film thickness and composition of brush were adjusted to induce perpendicular orientation in thin film. As the blend composition of the long asymmetric block copolymer increased, the PS lamellar thickness increased from 15.8 to 25.1 nm, whereas the PMMA lamellar thickness remained constant at approximately 14 nm (the thickness decreased slightly from 14.0 to 13.3 nm). The domain spacing behavior in thin film was consistent in the bulk. These results were compared with the Birshtein, Zhulina, and Lyatskaya model and the theories for pure block copolymers in the strong segregation limit and in the intermediate segregation regime. © 2013 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2013, 51, 1393–1399

The structural evolution in poly(styrene-b-butadiene) (P(S-b-B)) diblock copolymer thin films during solvent vapor treatment is investigated in situ using time-resolved grazing-incidence small-angle X-ray scattering (GISAXS). Using incident angles above and below the polymer critical angle, structural changes near the film surface and in the entire film are distinguished. The swelling of the film is one-dimensional along the normal of the substrate. During swelling, the initially perpendicular lamellae tilt within the film to be able to shrink. In contrast, at the film surface, the lamellae stay perpendicular, and eventually vanish at the expense of a thin PB wetting layer. During the subsequent drying, the perpendicular lamellae reappear at the surface, and finally, PS blocks protrude. By modeling, the time-dependent height of the protrusions can be quantitatively extracted.

A range of triphenylene and phthalocyanine-based discotic liquid crystals (DLCs) can be aligned within micrometer-scale channels formed from SU8 patterned on silicon or glass surfaces. The channels can be filled with the DLC in its isotropic phase using capillary action. Alignment occurs spontaneously as the sample is slowly cooled into the Colh phase. Whilst all of these DLCs align with the columns perpendicular to the surface when they are ‘sandwiched’ between glass slides, in these channels, the DLC aligns with the column director parallel to the surface. It is also constrained to lie across the channels. The same alignment occurs when these DLCs are confined between SU8-topped interdigitated gold electrodes where it gives the optimum orientation for electrode-to-electrode conduction. The quality of the alignment depends on the particular liquid crystal used and on the width of the channel. For the Colr phase of octaoctylphthalocyanine there is additional epitaxial control over the orientation of the lattice such that the a/c face of the lattice is parallel to the surface. This is an important prerequisite for creating a bistable display device that switches by virtue of changing the direction of the tilt of the discs.

Ordering transitions are observed in azo-dendrimer-dissolved nematic liquid crystal (NLC) droplets dispersed in a glycerol matrix. The dendrimer molecules are spontaneously attached at the interface between NLC and glycerol, so that the nematic directors orient perpendicular to the interface, in the radial configuration. Photoisomerization makes the directors be tangential to the interface, in a photoinduced ordering transition from radial to bipolar structure. Similar experiments are conducted both in cholesteric (Ch) and smectic-A (SmA) LC droplets. Complicated photoinduced ordering transitions are also observed in Ch and SmA droplets, and the associated molecular orientation changes are discussed. Photoisomerizable azo-dendrimer molecules provide a possible way to control orientation, even in microdroplet systems in which the interface cannot be treated by conventional surface agents.

Various methods describing the directionality of honed cylinder liner surface topography are compared. The procedure of deep valleys recognition and determination of angular spectra on the basis of ratio of valleys widths in perpendicular directions is described in detail. The applications of deep valleys analysis, power spectral density, and cross-correlation functions for measured plateau-honed cylinder surface topographies were studied. It was found that method based on the deep valleys study assured correct values of honing angle estimation. Procedure of sampling interval selection for this method application was developed. Usefulness of deep valleys analysis for obtaining parameters characterizing other features specific for cylinder liner surfaces is described.

Summary The effect of temperature and type of solvent on the microdomain orientation during solvent-annealing of block copolymer ultrathin films on silicon substrates was investigated using asymmetric polystyrene-block-poly(2-vinylpyridine) (PS-b-P2VP) diblock copolymer. When the solvent-annealing was performed with THF at 20°C, the ultrathin film exhibited a mixed orientation of cylinders parallel and perpendicular to the substrate while at 25°C only parallel cylinders were observed by AFM. The solvent annealing with acetone gave a dot pattern at 20°C and a line pattern at 25°C. On the other hand, in the case of solvent-annealing with toluene perpendicular cylinders were observed at 25°C while at 20°C the morphology was not clear. The orientation and morphology of microdomains as well as the kinetics in PS-b-P2VP ultrathin films on solvent-annealing is significantly affected by temperature and type of solvent. By controlling temperature and selecting the solvent, perpendicular cylinders can be formed predominantly on the substrates.

Summary We applied the microbeam two-dimensional small-angle X-ray scattering (2d-µSAXS) technique in order to characterize orientation of polystyrene (PS) microdomains as a function of the distance from the free surface of a sample sheet down to the surface facing to the substrate, for depth profiling for spontaneous perpendicular orientation of PS cylinders in the matrix of polyethylenebutylene (PEB) in a PS-b-PEB-b-PS triblock copolymer thick sheet as thick as ∼0.5 mm. It has been revealed that near the free surface the cylinders were randomly oriented down to ∼70 µm in depth. Although this might indicate that the surface effect, which preferentially dictates cylinders to be oriented parallel to the surface, can propagate for such a long distance, 70 µm is unusually huge as compared to the general knowledge of the surface effect propagating at most for 1 µm. Experimentally examining further, we finally conclude that the 2d-µSAXS depth profiling overestimates the surface effect. This unfavorable conclusion may be ascribed to surface roughness of the sample sheet subjected to the measurement, and in order to obtain a good result a big effort is required to prepare the surface as flat as possible.

The purpose of this paper is to develop an analytical method to decompose an observed anisotropic compliance tensor into two transversely isotropic (TI) tensors that are associated with layers and fractures. Specifically, the fracture parameters and the TI background medium parameters are obtained from a given monoclinic compliance tensor. Here the set of parallel fractures and TI medium can be arbitrarily oriented in ; they are not constrained to vertical and horizontal directions respectively. First the summation of the two TI tensors, which represent fractures and layerings, is obtained in order to have the form of the resultant monoclinic medium. The orientation of each TI medium is represented by one Euler angle once the mirror plane normal of the monoclinic tensor is determined. This is because the mirror plane normal of the monoclinic medium is perpendicular to the rotation axes of the two TI tensors. Thus a layered medium with one set of parallel fractures is represented by nine parameters; two for rotationally symmetric fractures, five for a generic background TI medium and two Euler angles for the orientations of the structures. The decomposition problem, which is to find these nine parameters from a given monoclinic compliance tensor with thirteen parameters, is solved in the paper. Finally, the decomposition method is extended to media with three structures, namely two sets of fractures and layerings whose rotation axes lie in the same plane.

To clarify the mechanism of the deformation and fracture in a low-velocity impact test on the isotactic polypropylene (i-PP) sheet made by injection molding, the change of the style of fracture and the form of deformation was examined while changing the speed of the striker in a low-velocity impact test. In the injection molding sheet, an oriented skin layer of some thickness is formed on the surface of the sample sheet. By the stress perpendicular to the orientation direction of the skin layer, crazes were formed easily in parallel with the orientation direction in this layer, and cracks were formed from there. Because these cracks bring the sample sheet a strong restraint of strain, a high stress concentration occurs at the end of this crack even if the formation of the oriented layer is limited on the surface of the sample sheet only, and the low-velocity impact test leads the sample sheet to a brittle fracture. As a result, the injection molding sheet that forms oriented structure on its surface causes the ductility-brittleness transform at a lower velocity of deformation compared with the nonoriented sheet. POLYM. ENG. SCI., 53:2659–2665, 2013. © 2013 Society of Plastics Engineers

Objective To compare the screw push-out strength and resistance to cantilever bending of 5 different angle-stable systems using 4 different insertion torque values to tighten locking screws. Study Design In vitro mechanical testing of 5 screw-plate constructs. Sample Population Screw plate constructs (n = 60) were tested; 12 of each design, 3 for each torque value. Methods To compare push-out strength, screws were loaded in axial direction on the screw tip until loosening of the locking mechanism was recorded. For cantilever bending test, screws were loaded perpendicularly to their longitudinal axis at 2 mm of distance from the under surface of the plate. Load was applied in displacement control at 1 mm/min. Results There was a significant difference between the 5 different angle-stable systems regarding both push-out and cantilever bending strength. There was an influence of insertion torque value on push-out strength for 2 systems and insertion torque value influenced cantilever bending behavior only in 1 locking system. Conclusions Locking mechanisms using “thread in thread” principle provided a stronger screw push-out behavior. Screws materials and core diameter of the different screws were directly related to cantilever bending strength.

The dependence of the magnetoresistance of iron-doped multi-walled carbon nanotubes (Fe-MWCNTs) on the carbon nanotubes arrangement, the temperature, the relative orientation of the magnetic field, and the current was investigated. The findings show that the magnetoresistance of partially-oriented Fe-MWCNTs is due to a combination of two mechanisms: (1) the giant magnetoresistance (GMR) that takes place in layered or cluster systems consisting of magnetic and nonmagnetic materials, and (2) the anisotropic magnetoresistance which is characteristic of ferromagnetic metals. For array-oriented Fe-MWCNTs the dominant mechanism of magnetoresistance depends on the relative orientation of the magnetic field and current through the sample, namely it depends on the localization mechanism at the mutually perpendicular orientation of the magnetic field and current and the GMR effect in mutual parallel orientation of the magnetic field and current.

Channeling a good catalyst: Highly porous palladium nanostructures (pPdNs) with perpendicular pore channels were prepared under mild conditions. The combination of high surface area and rich edge/corner atoms gives pPdNs better catalytic performance than known Pd catalysts for the hydrogenation of nitrobenzene and styrene and the Suzuki coupling reaction.

This paper describes a basic experiment and simulation of two peripheral visual field characteristics that are related to major factors in rural district accidents, namely, collision course relationships, and presence of objects in the peripheral visual field. The quantitative recognition threshold for shape changes (stimulus) in the peripheral visual field is studied. It is found that such critical dimensions as the diameter of a circle, the side length of a square or triangle, and the axis length of an oval are important in recognizing vehicles moving on a perpendicular course. It is shown that a similar principle applies to aircraft moving in three-dimensional space, not just to vehicles moving on a two-dimensional plane. This paper identifies the limit of the peripheral visual field characteristic, one of the human visual characteristics, and also shows that there is no dependence on figure shape for other figures whose maximum side size is the same as the diameter of the circle. © 2012 Wiley Periodicals, Inc. Electron Comm Jpn, 96(1): 25–32, 2013; Published online in Wiley Online Library (wileyonlinelibrary.com). DOI 10.1002/ecj.11428

This paper presents an analysis of fracture strength of multicrystalline silicon (mc-Si) solar wafers produced by slurry and diamond wire sawing. The wafers were bent in two orthogonal orientations relative to the saw marks. The fracture strength of slurry sawn wafers increases gradually from wire entry to wire exit whereas the strength variation in the wire feed direction is small. The fracture strength of diamond wire sawn wafers is bi-directional, with a higher strength if bent perpendicular to the saw marks and a lower strength if bent parallel to the saw marks. The fracture strength variation is related to the microcracks generated in the vicinity of grit-induced surface damage.

A series of samples consisting of alternating stripes of ZnO grown by molecular-beam epitaxy (MBE) and radio-frequency (rf) sputtered Ga-doped ZnO stripes was laterally microstructured with a self-aligned pattern transfer method. We measured as a function of temperature the Seebeck coefficient S and the electrical resistivity ρ in-plane of the samples with the transport direction perpendicular to the stripe direction. Throughout the series the bar width and hence the number of interfaces was kept constant, but the interface profile was varied yielding different interface lengths and geometries. The dependence of S, ρ and the power factor S2/ρ on the interface length at room temperature were simulated using an empirical network model and it was demonstrated that the macroscopic transport coefficients are very sensitive to the interface region and that even this rather simple modelling yields useful information about the interface region.

For a multitude of high-end applications such as photovoltaics and membranes for fuel cells or gas separation, creating large internal surfaces via fractal structuring during polymer processing can result in unique possibilities for enhancing performance. Structuring is possible even in processing techniques like injection molding. Inspired by microfluidic practice, an optimized splitting and recombining static mixer is realized on the parting surface of a mold. Different geometries are used to multiply, rotate, and add stratified structures. After the obvious structuring of a number of parallel layers, attention is focused on layers perpendicular to the product surface. A combination of the two allows complex hierarchical fractal structures to be obtained. A first demonstration of its feasibility is reported.

The impact of processing-induced chain orientation on the sliding wear behaviour of ultrahigh molecular weight polyethylene (UHMWPE) was investigated. The orientation of the molecular network of UHMWPE was done by means of uniaxial tension up to different residual strains. We found that high residual strain levels (higher than 0.45) enabled the sliding dissipated energy of UHMWPE to be decreased in dry conditions. In particular, oriented UHMWPE with a residual strain of 0.85 exhibited, at 500 000 sliding cycles in dry conditions, a decrease in volumetric wear loss by a factor of 3.3 and 19.4 compared with the reference UHMWPE tested in directions parallel and perpendicular to the chain direction, respectively. It is argued that oriented UHMWPE exhibits less adhesion during interfacial wear than the reference material, and hence orientation of UHMWPE bulk may be an alternative treatment to crosslinking for dry sliding conditions. In the case of sliding testing conducted in Ringer’s solution, the benefit of the initial chain orientation was quite weak due to a lubrication effect of the solution that markedly limited the effect of chain orientation on the sliding behaviour. c � 2012 Society of Chemical Industry

Perpendicular exchange bias (PEB) between [Co 0.3 nm/Pd 0.8 nm]5 multilayers and IrMn antiferromagnetic (AFM) layer is studied as functions of thickness of the interface layer and the AFM layer. It is found that increasing the thickness of a CoFe interface layer up to 2.1 nm could effectively improve the PEB. The achieved PEB field (Hbias) is more than 500 Oe. On the other hand, the coercivity (Hc) exhibits an opposite trend as a function of CoFe interface layer thickness, which might promote the integration of PEB structure with the perpendicular magnetic memory stack. It is also found that PEB is sensitive to the thickness of the AFM layer. The thickness window is only around 2 nm to achieve the largest Hbias. Moreover, for a very thin IrMn layer, a ferromagnetic nature is observed at low magnetic fields, which is likely owing to the net spins at the surface that might have been magnetized by the CoFe interface layer.

The wetting properties of 100Cr6 bearing steel surfaces modified using laser interference metallurgy (LIMET) are analyzed. The steel surfaces are structured with line-like patterns with line-spacing. The topography of the ridged surface is analyzed by means of white light interferometry and scanning electron microscopy and surface chemistry of the different topographic regions by Raman spectroscopy. Contact angle (CA) measurements are performed on modified and non-irradiated surfaces, using bi-distilled water and FVA2 industrial oil. The angles are measured parallel and perpendicular to the line-pattern orientation. The topographical analysis shows steep line-pattern produced by laser. Raman analysis indicates that the laser irradiation does not significantly change the chemical species of the modified surfaces. The CA measurements elucidates that the parallel orientation provides a better wetting of the surface, because the laser line-pattern acts as capillary flow channels, whereas the perpendicular orientation imposes energy barrier thus preventing wetting. As expected, the wetting coverage is more effective for larger than for smaller periodic structures, due to the larger area of flat contact. These novel results highlight the relevant use of LIMET to tailor the wetting properties of steel surfaces.

A continuum of stable remanent resistance states is reported in perpendicularly magnetized pseudo spin valves with a graded anisotropy free layer. The resistance states can be systematically set by ...

Purpose The magnetic fields of linac-MR systems modify the path of contaminant electrons in photon beams, which alters patient skin dose. To accurately quantify the magnitude of changes in skin dose, the authors use Monte Carlo calculations that incorporate realistic 3D magnetic field models of longitudinal and transverse linac-MR systems. Methods Finite element method (FEM) is used to generate complete 3D magnetic field maps for 0.56 T longitudinal and transverse linac-MR magnet assemblies, as well as for representative 0.5 and 1.0 T Helmholtz MRI systems. EGSnrc simulations implementing these 3D magnetic fields are performed. The geometry for the BEAMnrc simulations incorporates the Varian 600C 6 MV linac, magnet poles, the yoke, and the magnetic shields of the linac-MRIs. Resulting phase-space files are used to calculate the central axis percent depth-doses in a water phantom and 2D skin dose distributions for 70 μm entrance and exit layers using DOSXYZnrc. For comparison, skin doses are also calculated in the absence of magnetic field, and using a 1D magnetic field with an unrealistically large fringe field. The effects of photon field size, air gap (longitudinal configuration), and angle of obliquity (transverse configuration) are also investigated. Results Realistic modeling of the 3D magnetic fields shows that fringe fields decay rapidly and have a very small magnitude at the linac head. As a result, longitudinal linac-MR systems mostly confine contaminant electrons that are generated in the air gap and have an insignificant effect on electrons produced further upstream. The increase in the skin dose for the longitudinal configuration compared to the zero B-field case varies from ∼1% to ∼14% for air gaps of 5-31 cm, respectively. (All dose changes are reported as a % of D(max).) The increase is also field-size dependent, ranging from ∼3% at 20 × 20 cm(2) to ∼11% at 5 × 5 cm(2). The small changes in skin dose are in contrast to significant increases that are calculated for the unrealistic 1D magnetic field. For the transverse configuration, the entrance skin dose is equal or smaller than that of the zero B-field case for perpendicular beams. For a 10 × 10 cm(2) oblique beam the transverse magnetic field decreases the entry skin dose for oblique angles less than ±20° and increases it by no more than 10% for larger angles up to ±45°. The exit skin dose is increased by 42% for a 10 × 10 cm(2) perpendicular beam, but appreciably drops and approaches the zero B-field case for large oblique angles of incidence. Conclusions For longitudinal linac-MR systems only a small increase in the entrance skin dose is predicted, due to the rapid decay of the realistic magnetic fringe fields. For transverse linac-MR systems, changes to the entrance skin dose are small for most scenarios. For the same geometry, on the exit side a fairly large increase is observed for perpendicular beams, but significantly drops for large oblique angles of incidence. The observed effects on skin dose are not expected to limit the application of linac-MR systems in either the longitudinal or transverse configuration.

Induced polarization data recorded at the field scale are usually processed using techniques based on isotropy. We study the effect of anisotropic complex conductivities in the frequency domain, with a particular emphasis on the polarization properties (i.e., phase angles). We consider anisotropy to be caused by a thin layering of isotropic media. Based on this, we derive corresponding mixing laws for the phase angles parallel and perpendicular to the layering and show that in cases of anisotropic layering, phase angles can only exist if the complex conductivity magnitudes are also anisotropic. We modified an existing isotropic finite‐element forward modelling code to support anisotropic complex conductivities. Based on an isotropic 2D inversion of a synthetic data set generated for an anisotropic model, we show that ignoring anisotropy may lead to artefacts and poor model recovery. Finally, we investigate a field data set recorded over a fault system in Germany, where anisotropic conductivities are expected. The isotropic 2D inversion of this data set yields a complex image that is difficult to interpret. We suggest an alternative interpretation based on trial‐and‐error forward modelling with anisotropic complex conductivities, using geological a priori information to constrain the model. The obtained model has a much simpler structure, consistent with the anticipated geology but yet is able to explain the measured data.