Bar Width Research Articles

Coupling of Surface-Plasmon-Polariton-Hybridized Cavity Modes between Submicron Slits in a Thin Gold Film

Electron energy loss spectroscopy (EELS) in a monochromated transmission electron microscope is applied to probe standing-wave-like cavity modes hybridized with surface plasmon polaritons (SPP) in rectangular submicron slits in a thin gold film. Coupling of hybridized SPP-cavity modes between two adjacent slits is studied by systematically varying the width of the metal bar d that separates the identical slits in a two-slit system. Measurements on two-slit systems with different slit lengths L and fixed width reveal energy shifts and mode splitting of the fundamental SPP cavity mode which can be generally described as a function of a dimensionless scaling parameter L/d. Numerical simulations with the Discontinuous Galerkin Time-Domain (DGTD) method confirm the experimental data and reveal insights into the underlying complex coupling mechanisms.

P-193L:Late-News Poster: Everybody Can Improve Motion Image Quality of One's LCD by Only Visual Inspection

This paper proposes a novel method to find out optimum overdrive (OD) values through only users' visual inspection. To investigate the relation between OD values measured from optical equipment and human eyes, three scrolling bar width (Viewing angle) and three difference values from the measured OD value (Delta) are used in the experiment. We found that people distinguish delta 1 when the viewing angle of scrolling bar was 4° is used. We propose an application of proposed pattern to a smart device. Users can optimize the OD values quickly and easily with their own eyes without any knowledge about OD technology.

Semi-empirical calculation for design of flexural mode silicon mechanical resonator with variable cross section

This paper newly proposes a semi-empirical calculation for design of electrostatically driven flexural mode silicon (Si) mechanical resonators with a variable cross section which is applicable to a feasibility study of their development without finite element analysis (FEA). In the design for Si mechanical resonators with a variable cross section, a mode function describing a shape of vibration is simply assumed to be a static deflection function, and a resonant frequency is derived by applying the Rayleigh-Ritz method. The static deflection function, which reflects an effect of stress concentration generated by a variation of cross section, is semi-empirically formulated using some FEA results. This research adopts a clamped–clamped beam Si mechanical resonator which a wide rectangular bar located at the center is supported by same two narrow rectangular bars clamped to anchors. The resonant frequencies of the Si mechanical resonators are calculated within a mean absolute percentage error of 3% from the FEA results. In order to confirm the applicability of the semi-empirical formula, twenty different sizes of clamped–clamped beam Si mechanical resonators having the first-mode resonant frequency of 5–20MHz are designed and fabricated from a silicon-on-insulator (SOI) wafer, and their vibration characteristics in a vacuum environment are measured by a network analyzer. From the comparison with the measured resonant frequency of each Si mechanical resonator, the mean and maximum absolute percentage errors of the semi-empirical calculation are 28.6 and 51.3%, respectively, which are not negligible errors for the feasibility study. The fabricated Si mechanical resonators are different from an ideal clamped–clamped beam due to undercuts of the insulator layer under the anchors. The resonant frequency of each Si mechanical resonator is analyzed by the FEA model taking into account the effect of the undercuts. The mean and maximum absolute percentage errors of the FEA results from the measured ones are reduced to 9.61 and 19.9%, respectively. These results show that the large errors of the semi-empirical calculation are mainly caused by the undercuts, i.e., flexural stiffness degradation at both clamped ends. Under the condition that the FEA results obtained from FEA models precisely imitating actual geometry and boundary condition are used in the semi-empirical calculation, this is adequately applicable to the feasibility study for developing the Si mechanical resonator with a variable cross section.

Sequential learning of relative size by the Neotropical ant Gigantiops destructor.

The question of whether insects can perform concept learning or can use the geometry of space as in mammals has been recently addressed in Hymenoptera in an extensive way. We investigate here the ability of the tropical ant Gigantiops destructor to perform sequential learning and to use size relationships during navigation. Ants were trained to solve a dichotomic six-stage linear maze relying on the apparent width of two vertical landmarks. Each individual ant first learnt to associate a given landmark width to the motor decision of turning right or left to avoid dead-ends independently of a motor routine. When confronted for the first time with a new intermediate-sized pattern, for which no supposed snapshot could have been stored, ants made directional choices indicating that bar width judgments were not absolute but rather relative to the familiar visual patterns seen in the previous chambers. This result demonstrates that ants can generalize relationship rules by interpolating the relative width of a novel stimulus according to visual information kept in spatial working memory. In conclusion, ants can perform conditional discriminations reliably not only when stimuli are simultaneous but also when they are sequential.

On interfacial energy of macroscopic domains in polycrystalline NiTi shape memory alloys

Under tension or tension/torsion combined loading, the formation and movement of macroscopic interfaces (domain fronts which separate the austenite and martensite regions) in the phase transition of a bulk fine-grained polycrystalline NiTi shape memory alloy (SMA) bar or tube specimen are well-observed phenomena. The interfacial energy of the macroscopic domain front, i.e., the energy per unit area of the front (interface), competes with the bulk energy of the system and plays an important role in understanding and modeling both equilibrium and non-equilibrium domain patterns. This paper investigates the physical origin of the interfacial energy of a planar interface and its orientation and length scale dependences in a bar structure. The energetics of a martensite domain with such a planar interface is quantified by using an elastic inclusion model. We show that the strain energy due to the presence of the martensite domain consists of two parts, the bulk energy (such as from bending) due to the constraints at the bar ends and the localized energy due to the mismatch between the spontaneous transformation strain of the domain and the surrounding austenite. The latter is stored around the domain front and is named as the interfacial energy (domain front energy). It is proved that the interface or the domain front of the bar prefers the orientation that minimizes the system total energy. This is supported by comparison with the experimental observation. The dependences of the interfacial energy on the bar geometry (bar thickness and width), the transformation strain and the interface orientation are quantified.

The design of the totally active scintillator detector

In the project of Advanced European Infrastructures for Detectors at Accelerators (AIDA), the Institute of Nuclear Research designed and tested the Totally Active Scintillator Detector (TASD). This paper reports the results of design of TASD prototype and outlines requirements for a test beam at CERN to test these, tentatively planned on the H8 beamline in the North Area, which is equipped with a large aperture magnet. TASD consists of 50 modules of plastic scintillators. Each module is instrumented with one X and one Y plane, with 90 scintillator bars per plane. The bar width, height and length are 1.0 cm, 0.7 cm and 90 cm respectively. The distance between modules can be varied from 0 to 2.5 cm. Other components such as active detectors or passive sheets of material can be inserted in these 2.5 cm gaps if required. The full detector depth can therefore be varied from 75 cm to 200 cm and in its compact form, it is 1 m3 in volume. The paper presents measurement results for the TASD elements that included in the prototype elements (measurement of crosscurrents, the light yield of scintillators, and the characteristics of photodiodes).

Female genital morphology and sperm storage in the velvet spiderEresus kollari(Araneae: Eresidae)

Abstract In the present study, we examined the female genital system of a velvet spider (Eresus kollari Rossi 1846) using light and electron microscopy. The female entelegyne genitalia of E. kollari comprises an epigyne with an anterior wide longitudinal bar and folds which are incurvated sidewards. The anterior end of these folds corresponds to enlarged anterior bulges which are connected to a distinct copulatory duct leading to lobular spermathecae. The anterior bulge is equipped with many large pores whereas the spermathecae has many small pores. At present, only a few studies have focussed on the ultrastructure and possible function of adjacent epithelia in entelegyne genitalia of spiders revealing the presence of complex class 3 gland cell units around the spermathecae and ducts. Alternatively our analysis finds two different types of epithelia. The anterior bulge is equipped with class 3 gland cells whereas the spermathecae are surrounded by a putative transport epithelium. This epithelium is charac...

Female genital morphology and sperm storage in the velvet spiderEresus kollari(Araneae: Eresidae)

In the present study, we examined the female genital system of a velvet spider (Eresus kollari Rossi 1846) using light and electron microscopy. The female entelegyne genitalia of E. kollari comprises an epigyne with an anterior wide longitudinal bar and folds which are incurvated sidewards. The anterior end of these folds corresponds to enlarged anterior bulges which are connected to a distinct copulatory duct leading to lobular spermathecae. The anterior bulge is equipped with many large pores whereas the spermathecae has many small pores. At present, only a few studies have focussed on the ultrastructure and possible function of adjacent epithelia in entelegyne genitalia of spiders revealing the presence of complex class 3 gland cell units around the spermathecae and ducts. Alternatively our analysis finds two different types of epithelia. The anterior bulge is equipped with class 3 gland cells whereas the spermathecae are surrounded by a putative transport epithelium. This epithelium is characterized by an extensive basal labyrinth, numerous mitochondria, and an invaginated cell apex with microvilli. The functions of the different parts are unclear, but the secretion produced by the class 3 cell glands in the anterior bulge could be involved in the transport of sperm by flushing a considerable quantity of secretion towards the posterior. Alternatively, it could also contribute to the amorphous mass which is formed during mating covering most of the epigyne. On the other hand, the epithelium around the spermathecae might only be involved in the alteration of the milieu in the spermathecal lumen but not contribute to the nutrition of spermatozoa during sperm storage.

White tail spots in breeding Barn SwallowsHirundo rusticasignal body condition during winter moult

The determinants and function of pigmentation of feathers and other tissues have been the focus of a large number of studies, particularly with respect to socio‐sexual communication. However, many birds exhibit depigmented white spots or bars on their feathers whose function is poorly understood. Here we assess whether white feather spots reflect phenotypic condition at the time of moult by investigating the covariation between spot size or shape and condition‐dependent feather growth rate, as gauged by width of the growth bars on the tail feathers of Barn Swallows. We found that feathers with higher growth rates had larger, less rounded white spots. In addition, variance in spot perimeter for a given spot area was larger in males than in females. This study is the first to provide evidence that features of white markings on feathers directly reflect body condition at the time of moult and can therefore reliably signal phenotypic quality in the context of socio‐sexual communication. In addition, the study highlights the potential communication function of the shape and not just the size of colour signals.

Sexual Dimorphism and Population Differences in Structural Properties of Barn Swallow (Hirundo rustica) Wing and Tail Feathers.

Sexual selection and aerodynamic forces affecting structural properties of the flight feathers of birds are poorly understood. Here, we compared the structural features of the innermost primary wing feather (P1) and the sexually dimorphic outermost (Ta6) and monomorphic second outermost (Ta5) tail feathers of barn swallows (Hirundo rustica) from a Romanian population to investigate how sexual selection and resistance to aerodynamic forces affect structural differences among these feathers. Furthermore, we compared structural properties of Ta6 of barn swallows from six European populations. Finally, we determined the relationship between feather growth bars width (GBW) and the structural properties of tail feathers. The structure of P1 indicates strong resistance against aerodynamic forces, while the narrow rachis, low vane density and low bending stiffness of tail feathers suggest reduced resistance against airflow. The highly elongated Ta6 is characterized by structural modifications such as large rachis width and increased barbule density in relation to the less elongated Ta5, which can be explained by increased length and/or high aerodynamic forces acting at the leading tail edge. However, these changes in Ta6 structure do not allow for full compensation of elongation, as reflected by the reduced bending stiffness of Ta6. Ta6 elongation in males resulted in feathers with reduced resistance, as shown by the low barb density and reduced bending stiffness compared to females. The inconsistency in sexual dimorphism and in change in quality traits of Ta6 among six European populations shows that multiple factors may contribute to shaping population differences. In general, the difference in quality traits between tail feathers cannot be explained by the GBW of feathers. Our results show that the material and structural properties of wing and tail feathers of barn swallows change as a result of aerodynamic forces and sexual selection, although the result of these changes can be contrasting.

Performance of Corroded Reinforced Concrete Columns under the Action of Eccentric Loads

AbstractThis paper presents an experimental investigation on the performance of RC columns with corroded reinforcing steel bars. The corrosion of steel bars was induced by using a combined electrochemical process and wet-dry cycles. The corroded-RC columns were tested under eccentric-compressive loading, from which the residual strength of the columns was obtained. Relationships between the average cross-sectional area loss of the steel bar, the average and maximum crack widths of concrete cover, and the strength loss of the RC column were examined. Finally, a load-carrying capacity model is proposed to quantitatively estimate the residual compressive strength of the corroded-RC column.

Inhibitory input to the direction-selective ganglion cell is saturated at low contrast.

Direction-selective ganglion cells (DSGCs) respond selectively to motion toward a "preferred" direction, but much less to motion toward the opposite "null" direction. Directional signals in the DSGC depend on GABAergic inhibition and are observed over a wide range of speeds, which precludes motion detection based on a fixed temporal correlation. A voltage-clamp analysis, using narrow bar stimuli similar in width to the receptive field center, demonstrated that inhibition to DSGCs saturates rapidly above a threshold contrast. However, for wide bar stimuli that activate both the center and surround, inhibition depends more linearly on contrast. Excitation for both wide and narrow bars was also more linear. We propose that positive feedback, likely within the starburst amacrine cell or its network, produces steep saturation of inhibition at relatively low contrast. This mechanism renders GABA release essentially contrast and speed invariant, which enhances directional signals for small objects and thereby increases the signal-to-noise ratio for direction-selective signals in the spike train over a wide range of stimulus conditions. The steep saturation of inhibition confers to a neuron immunity to noise in its spike train, because when inhibition is strong no spikes are initiated.

Optimization of parabolic bars for maximum Bragg resonant reflection of long waves

This paper presents an analytical solution for the problem of the long wave reflection by a series of artificial bars with parabolic configuration in terms of the associated Legendre functions. It is shown that both the reflection and transmission coefficients depend solely upon the number of bars, the dimensionless bar height, the dimensionless bar width and the dimensionless bar distance. Particularly, under the Bragg resonance condition, i.e., the distance between two adjacent bars is about half of the wavelength of the normal incident waves, the analytical solution for the peak Bragg resonant reflection is obtained, which reveals that the peak Bragg resonance depends upon the number of bars, the dimensionless bar height and the dimensionless bar width. Based on this solution, the optimization of the parabolic bars is made to obtain the maximum Bragg resonance and a group of optimal curves, which may be very useful in the design of Bragg breakwaters with parabolic bars.

Energy harvesting from a vehicle suspension system

A dual-mass piezoelectric bar harvester is developed for energy harvesting from ambient vibrations of a vehicle suspension system subjected to roughness of road surfaces. The harvester is made of a sprung mass (body mass) and an unsprung mass (wheel mass) connected by a piezoelectric bar transducer which is equivalently modeled as a suspension spring and a damper in a mathematics model. The dual-mass piezoelectric bar harvester is practically designed in a vehicle suspension system on wheels to generate an electric charge. To describe the energy harvesting process, a mathematics model is developed to calculate the output charge and voltage from the harvester by an iteration method in the temporal domain. The influences of some practical considerations, such as the width of the piezoelectric bar, the speed of vehicles, and the class of the road roughness, on the root mean square of the generated electric power are discussed. Our results show that a power up to 738 W can be realized for a practical design of the harvester with a width and height of the piezoelectric bar of 0.015 m and 0.1 m respectively. This research develops a new design method for efficient and practical energy harvesting from vehicle vibrations.

Critérios técnicos para a seleção de pulverizadores autopropelidos comercializados no mercado brasileiro

Nos últimos anos, a oferta de pulverizadores autopropelidos no mercado brasileiro aumentou, principalmente para suprir a demanda de agricultores que possuem grandes extensões de áreas, nas quais se requer um alto ritmo operacional. Neste trabalho, foram avaliados, em função da potência nominal do motor, os diferentes tipos de transmissões, a capacidade do reservatório de calda, tamanho das barras e vão livre, considerados critérios técnicos importantes para a seleção dessas máquinas. Para tanto, utilizaram-se informações técnicas de 41 modelos de pulverizadores autopropelidos comercializados no mercado brasileiro. Como resultado, classificaram-se os pulverizadores em cinco classes, segundo a potência do motor. Verificou-se que, com o aumento da potência, os pulverizadores são equipados com transmissão hidrostática e a capacidade dos reservatórios de calda são maiores.

Modeling and experimental analysis of squeeze flow of sealant during hot bar sealing and methods of preventing squeeze-out

Excessive pressure and temperature during hot bar sealing of flexible packaging films can result in seal failure due to squeezing out of the sealant from the seal area. A model is developed that shows the amount of squeeze-out increases with increasing seal bar pressure, seal temperature (by lowering the viscosity of the sealant), sealing dwell time, film thickness, and decreasing seal bar width. Validation experiments qualitatively agree with the model predictions. Both the model and experimental results show that the rheology of the sealant plays a significant role in preventing squeeze-out; high viscosity at low shear rates favor less squeeze-out. The work shows that under normal sealing conditions, squeeze-out is not substantial. Avoiding excessive temperature or pressure is critical to minimizing squeeze out to ensure good sealing performance.

Stata Tip 122: Variable Bar Widths in Two-Way Graphs

Stata Tip 122: Variable Bar Widths in Two-Way Graphs

Light-level geolocators reveal covariation between winter plumage molt and phenology in a trans-Saharan migratory bird

Contingent individual performance can depend on the environment experienced at previous life-stages. Migratory birds are especially susceptible to such carry-over effects as they periodically travel between breeding ranges and 'wintering' areas where they may experience broadly different ecological conditions. However, the study of carry-over effects is hampered by the difficulty of tracking vagile organisms throughout their annual life-cycle. Using information from light-level geolocators on the barn swallow (Hirundo rustica), we tested if feather growth bar width (GBW), a proxy of feather growth rate which depends on individual condition, and wing isometric size and shape predict the phenology of subsequent migration. GBW did not predict duration of wintering but negatively predicted the duration of spring migration and arrival date to the breeding sites, suggesting that migration phenology is not constrained by molt, and individuals in prime condition achieve both faster molt and earlier arrival. Wing morphology did not predict migration duration, as expected if wing shape were optimized for foraging, rather than migration performance, in this aerially foraging, insectivorous bird. Thus, we showed for the first time that migration phenology in a long-distance migratory bird covaries with body condition during wintering, as reflected by the growth rate of feathers.

Fast strain wave induced magnetization changes in long cobalt bars: Domain motion versus coherent rotation

A high frequency (88 MHz) traveling strain wave on a piezoelectric substrate is shown to change the magnetization direction in 40 μm wide Co bars with an aspect ratio of 103. The rapidly alternating strain wave rotates the magnetization away from the long axis into the short axis direction, via magnetoelastic coupling. Strain-induced magnetization changes have previously been demonstrated in ferroelectric/ferromagnetic heterostructures, with excellent fidelity between the ferromagnet and the ferroelectric domains, but these experiments were limited to essentially dc frequencies. Both magneto-optical Kerr effect and polarized neutron reflectivity confirm that the traveling strain wave does rotate the magnetization away from the long axis direction and both yield quantitatively similar values for the rotated magnetization. An investigation of the behavior of short axis magnetization with increasing strain wave amplitude on a series of samples with variable edge roughness suggests that the magnetization reorientation that is seen proceeds solely via coherent rotation. Polarized neutron reflectivity data provide direct experimental evidence for this model. This is consistent with expectations that domain wall motion cannot track the rapidly varying strain.

A reassessment of the horned dinosaur Judiceratops tigris (Ornithischia: Ceratopsidae) from the Upper Cretaceous (Campanian) of Montana, USA

Judiceratops tigris is a recently described ceratopsid, collected from sediments of the Upper Cretaceous (middle Campanian) Judith River Formation (JRF) of northern Montana, USA. The current diagnosis for this taxon is tentative, as it is based on four fragmentary cranial specimens that have limited anatomical overlap. Although these four specimens were not found associated, they were all collected from the same localized area (Kennedy Coulee). New observations, interpretations, and reconstructions of J. tigris are presented in this study, based on the original assumption that these specimens represent the same taxon. Based on these findings, J. tigris had elongate postorbital horncores with an autapomorphic ovate (egg-shaped) cross section; squamosals with non-imbricated episquamosals, and an anterolaterally oriented anteriormost episquamosal; a wide medial parietal bar with an autapomorphic meniscus-shaped cross section; an anteroposteriorly wide posterior parietal bar, and, consequently, reduced parietal fenestrae; and at least four small, low-lying epiparietals on each side of the frill. A phylogenetic analysis incorporating the revised diagnosis of J. tigris supports the previous referral of this taxon to Chasmosaurinae, but missing anatomy prevents an understanding of how J. tigris is related to other chasmosaurines. Judiceratops tigris is retained here as a distinct taxon, and, hence, the oldest known chasmosaurine, but it has more in common with other chasmosaurines than was previously thought. Further fossil collecting in the JRF of Montana may produce more complete specimens of J. tigris and provide a means of testing the new reconstructions presented here.