Influence of front light configuration on the visual conspicuity of motorcycles

A recent study (Cavallo and Pinto, 2012) showed that daytime running lights (DRLs) on cars create “visual noise” that interferes with the lighting of motorcycles and affects their visual conspicuity. In the present experiment, we tested three conspicuity enhancements designed to improve motorcycle detectability in a car-DRL environment: a triangle configuration (a central headlight plus two lights located on the rearview mirrors), a helmet configuration (a light located on the motorcyclist's helmet in addition to the central headlight), and a single central yellow headlight. These three front-light configurations were evaluated in comparison to the standard configuration (a single central white headlight). Photographs representing complex urban traffic scenes were presented briefly (for 250 ms). The results revealed better motorcycle-detection performance for both the yellow headlight and the helmet configuration than for the standard configuration. The findings suggest some avenues for defining a new visual signature for motorcycles in car-DRL environments.     

Eikonal equation‐based front propagation for arbitrary complex configurations

This paper presents a front propagation method using the Eikonal equation, ?? ? ?? = 1, in which, ? represents the smallest Euclidean distance field to the front to be propagated. The offset capturing approach consists in first calculating the ? field over a uniform Cartesian grid fully covering the front to be propagated, and then constructing the iso‐? curves or surfaces as the propagated result. The calculation of ? uses a 3D numerical scheme, the Fast Sweeping Scheme. Validation for accuracy of the method is presented using academic test cases. A real 3D industry application, draft tube with two piers, is successfully propagated and demonstrated using special boundary conditions to cope with inlet and outlet planes during front propagtion. This application involves the propagation of a front that exhibits both concave and convex shape regions, sharp corners, and local tangent plane surface discontinuities as well as a multi‐connected domain. Copyright © 2007 John Wiley & Sons, Ltd.     

Separation of DNA with different configurations on flat and nanopatterned surfaces

We demonstrate that electrophoresis on a flat Si substrate is an effective method in separation of DNA with different configurations, e.g., linear, supercoiled, and relaxed or DNA of different length, e.g., supercoiled DNA ladder. The surface separation arises from the different number of contacts due to the conformational differences between adsorbed DNA chains. Imposing a Au nanopattern on the Si surface further improves the separation effect. The simulation of electric field on this patterned surface by the finite element method shows that Au nanodots act as local pinning points for DNA segments due to dielectrophoretic force. The results of molecular dynamics simulation showed that the conformational differences between adsorbed polymer chains were amplified on the patterned surface and enhanced separations were achieved, which are consistent with the experimental results.     

Clearance of small molecules in different dialyzer flow configurations

To overcome problems of insufficient clearance, multiple dialyzers may be placed in series or in parallel. The present study aimed to investigate in vitro the overall clearance of small molecules in different dialyzer configurations in which mutual flow directions were changed. Single pass tests were performed with low flux Fresenius F6HPS dialyzers placed in series (12 tests), in parallel (6) and in single use (2). As blood substitute, either high concentrated (45 mS) bicarbonate dialysate (AB solution – MW20‐180) or a trisodiumphosphate (Na₃PO₄– MW395) concentration (30 mS) was used. Standard blood and dialysate flows of 250 and 500 mL/min, respectively, were applied. Furthermore, clearance was derived from conductivity measurements in the inlet and outlet bloodline, correcting for the overall ultrafiltration rate of 0.5 L/h (AB) and 0.1 L/h (Na₃PO₄). Compared to the standard setup using a single dialyzer with counter current flows, clearance increases by 3 to 8%(AB) and by 15 to 18%(Na₃PO₄) using two dialyzers in parallel and in series, respectively. With co‐current flows in a serial dialyzer set up, clearance increases by 16%(AB) and 22%(Na₃PO₄) compared to the single dialyzer use. Changing subsequently the counter current flows to co‐current in one and both dialyzers in series, the overall clearance decreases by 2 to 9%, respectively, for the AB solution, and by 8 to 15% for the Na₃PO₄ concentration. With respect to the parallel dialyzer setup, a split dialysate flow (250 mL/min in each dialyzer) counter current to the blood flow, increases the clearance by 4 and 12%, respectively. In conclusion, overall clearance is most ameliorated using two dialyzers in series with counter current flows.     

Solvability and thermal response of cellulose with different crystal configurations

Cellulose is a biodegradable and renewable natural material that it is naturally resistant to breaking and modification. Moreover, the crystalline structure of cellulose is a major factor restricting its industrial utilization. In this study, cellulose polymorphs were prepared from natural cellulose, and their solvability and thermal response were investigated. Using liquid- and solid-state NMR signals, the distinct types and dissolving states of cellulose polymorphs were identified. The thermal behavior of the polymorphic forms of cellulose-d was also evaluated, and cellulose II exhibited the poorest thermal stability and a unique exothermic reaction.     

On the efficiency of hybrid regenerators with different matrix configurations

In this technical note some experimental results obtained using a suitably hybridized single stage Gifford McMahon cryocooler are presented. Regenerator efficiency values are given for different matrix configurations. By a particular ‘microsphere bed’ configuration we attain a minimum working temperature of 35 K and a net refrigeration power greater than 6 W at liquid nitrogen temperature.     

Performance of different phoswich configurations in a balloon flight experiment

Four different phoswich units were included in a modular hard X-ray balloon experiment launched on August 10, 1982 in order to check the dependence of background level and rejection efficiency of NaI(Tl)/CsI(Na) phoswich detectors on scintillator thicknesses. The results concern the dependence of the background intensity on both the thickness of the active shield, for a fixed primary detector thickness, and on the thickness of the primary detector, given the active shield thickness. A direct comparison of phoswich detectors with passively shielded NaI(Tl) crystals is also given. As a consequence practical hints for designing new phoswich detectors are derived and the limiting sensitivity of these detectors for hard X-ray observations of celestial sources is inferred.     

Analytical closed-form solutions for different configurations of parallel-coupled microstrip lines

Closed-form solutions are presented for the even- and odd-mode impedances of the parallel-coupled microstrip lines with different configurations. The first set of equations is for the conventional-coupled microstrip lines. The second set is for the parallel-coupled microstrip lines with a slotted ground plane and the third set is for the parallel-coupled microstrip lines with a slotted ground plane and a floating-potential conductor added to cover most of the slot in the ground plane. The solution is achieved using the conformal mapping technique, which also considers the effect of any fringe capacitor that has an impact on the impedance of the coupled lines. To validate the accuracy of the presented equations, a comparison is made with the available empirical solution (only for the conventional-coupled microstrip lines), a numerical solution (using Galerkin?s technique) and the full-wave electromagnetic solution using the software HFSS. The result of the comparison indicates the high accuracy of the presented equations over a wide range of design parameters. The difference between the calculated values using the derived equations and those from the full-wave electromagnetic analysis is ,5% for most of the cases. To validate the derived equations experimentally, they are used to design a 3 dB coupler. The result of measurements on the manufactured coupler confirms the accuracy of the presented equations.     

Judgments of approach speed for motorcycles across different lighting levels and the effect of an improved tri-headlight configuration

The misperception of vehicle approach speed is a key contributory factor to road traffic crash involvement. Past research has indicated that individuals use the rate of visual looming to calculate the time to passage (TTP) of a vehicle, and that smaller vehicles loom to a lesser extent than larger vehicles. Despite a disproportionate number of fatal injuries occurring on the road after dark, and a higher than average number of accidents involving automobile drivers violating the right of way of a motorcyclist occurring in low light conditions, there has been very little consideration of the accuracy of TTP for smaller and larger vehicles under low levels of luminance. We investigated drivers’ judgments of motorcycle and car approach speeds across a number of levels of luminance within a virtual city scene, as well as the effectiveness of a tri-headlight formation on motorcycle speed judgments. The accuracy of car approach speed judgments were not affected by changes in lighting conditions, but speed judgments for the solo headlight motorcycle became significantly less accurate as lighting reduced in the early night and night-time conditions. Incorporation of a tri-headlight formation onto the standard motorcycle frame resulted in improved accuracy of approach speed judgments, relative to the solo headlight motorcycle, as ambient light levels reduced. The practical implications of the findings are discussed in terms of road safety and motorcycle design.     

Force-deflection behavior of NiTi archwire at different configurations of bracket system

NiTi shape memory alloy archwire is widely used in orthodontic treatment, replacing stainless steel for the flat and low deactivation force it can offer. However, the presence of friction at the contact region of wire and bracket may cause the low deactivation force to be ineffective to induce tooth movement. This work evaluated the bending deformation behavior of NiTi archwire in application using conventional orthodontic stainless steel bracket in levelling treatment. Experimental test rig was developed to perform three-brackets bending test at room temperatures (27 °C). The bracket used was 0.022-in stainless steel and the archwire was 0.016-in NiTi round wire. Fabricated polytetrafluoroethylene (Teflon) bracket was used as a control experiment to represent frictionless condition of deformation on three-bracket bending. Additionally, elastomeric ligature was also used to evaluate the effect of friction produced by the elastomer. Bending tests were done at 3 different deflection magnitudes of 2 mm, 3 mm and 4 mm. The results show that bending deformation behavior of the wire on frictionless Teflon bracket produced a flat force plateau on both activation and deactivation. On the other hand, when stainless steel brackets were used, the force plateau exhibited positive gradient on the activation and negative gradient on the deactivation.     

Full-depth flexible pavement responses to different truck tyre geometry configurations

Pavement stresses and strain responses due to tyre loading are essential data for design and performance analysis. The magnitude and distribution of these responses are primarily affected by the tyres configuration geometry. This study investigates the longitudinal strain responses at the bottom of a hot-mix asphalt layer for full-depth medium-volume flexible pavement under different truck tyres design. Pavement testing was carried out with a user-control accelerated pavement facility at various speeds and tyre inflation pressures and loading. Three truck tyre configurations: dual-tyre (11R22.5) and two wide-base tyres (425/65R22.5 and 455/55R22.5) widely used in the truck industry were examined. A 3D finite element model was developed to quantify surface stresses to loading at various critical locations in the pavement after being calibrated with the field-measured strains. Field measurements showed that the 455 wide-base tyres yield 7% more longitudinal strain than a dual-tyre assembly at the same tyre pressure.     

Numerical study on the mixing performance of a ring-type electroosmotic micromixer with different obstacle configurations

A new type of electrokinetic micromixer with a ring-type channel is introduced for fast mixing. The proposed mixer takes two fluids from different inlets and combines them in a ring-type mixing chamber. The fluids enter two different inlets (inner radius: 25 microm and outer radius: 50 microm), respectively. The total channel length is 500 microm, and four microelectrodes are positioned on the outer wall of the mixing chamber. The electric potentials on the four microelectrodes are sinusoidal with time, having various maximum values of voltage, zeta potential and frequency. Also, in order to compare the mixing performance with different obstacle configurations, we performed a numerical analysis using a commercial code, COMSOL. The concentration of the dissolved substances in the working fluid and the flow and electric fields in the channel were investigated and the results were graphically depicted for various flow and electric conditions.     

4种不同加注结构在无排放加注中的性能比较

以175 L立式低温绝热气瓶为载体,对L型、U型、侧喷淋和直管4种不同的加注结构进行了实验研究,根据各结构随着供液压力变化对气瓶压力、最终充满率和加注时间的性能影响,得出直管加注结构更适用于小型立式低温容器的加注结构。通过分析各加注结构的结构特性及效果,验证了MMCAP(Martin Marietta Crgogenic Analysis Program)分析模型关于液面扰动比气相空间气液混合更容易提高冷凝率的预测是合理的。     

Hybrid laser/arc welding of thick high-strength steel in different configurations

In this investigation, hybrid laser/arc welding (HLAW) was employed to join 8-mm-thick high-strength quenched and tempered steel (HSQTS) plates in the butt-and T-joint configurations. The influences of welding parameters, such as laser power, welding speed, stand-off distance (SD) between the arc of gas metal arc welding, and the laser heat source on the weld quality and mechanical properties of joints, were studied to obtain non-porous and crack-free fully-penetrated welds. The weld microstructure, crosssection, and mechanical properties were evaluated by an optical microscope, and microhardness and tensile tests. In addition, a finite element model was developed to investigate the thermal history and molten pool geometry of the HLAW process to join the HSQTS. The numerical study demonstrated that the SD had a paramount role in good synergy between the heat sources and the stability of the keyhole. For the butt-joint configuration, the results showed that, at a higher welding speed (35 mm/s) and optimum SD between the arc and laser, a fully-penetrated sound weld could be achieved. A non-porous weld in the T-joint configuration was obtained at a lower welding speed (10 mm/s). Microstructural evaluations indicated that the formation of residual austenite and the continuous network of martensitic structure along the grain boundary through the heat affected zone were the primary reasons of the softening behavior of this area. This was confirmed by the sharp hardness reduction and failure behavior of the tensile coupons in this area.The full text can be downloaded at https://link.springer.com/article/10.1007/s40436-017-0193-6     

The kinematic features of motorcycles in congested urban networks

The aim of this paper is to compare the kinematic features of motorcycles with those of passenger cars in urban traffic. The hypothesis that motorcycles’ capability to swerve in urban traffic contributes to their seemingly assertive behaviour is examined. Data for this study were collected in afternoon peak hours at Central London using video recorders. Detailed information on the trajectories of 2109 vehicles (including 477 motorcycles and 1293 passenger cars) was extracted from the video images and the observable kinematic features were analysed. In addition, a model describing the longitudinal following behaviour of motorcycles was employed to analyse the impacts of motorcycles’ swerving behaviour. The model was calibrated using Markov Chain Monte Carlo (MCMC) numerical methods. The observable kinematic features show that in comparison to passenger cars, motorcycles have shorter safety gaps, higher speeds and severer acceleration and deceleration rates reflecting their generally much higher power to weight ratios and usage of available braking power. However, the data also support the hypothesis that motorcyclists maintain a considerable safety margin as they have the ability to avoid a collision by swerving away.     

Survival hazards of road environment factors between motor-vehicles and motorcycles

Motorcycles are frequently used in middle- and low-income societies. They are often involved in crashes, and account for a noticeable percentage of fatalities secondary to crashes. Comparing motor-vehicle occupants and motorcycle riders, the present study examined the survival hazard of crash injuries with respect to road environmental factors (i.e., area, road type, and location). We investigated the effects of such factors on survival and survival time after crashes via a binary logistic regression analysis and a Cox proportional hazard regression analysis, respectively. Results indicated that, for both motor-vehicle occupants and motorcycle riders, the fatal prevalence, occurrence likelihood, and risk based on time were decreased in urban areas and elevated on highways. The three indexes were also higher for motor-vehicle occupants on non-straight or non-level roadway sections. The prevalence of death on local roads and at intersections was relatively higher for motorcycle riders compared to motor-vehicle occupants. Speed may contribute to the survival hazard with respect to road environment factors. Speed management initiatives account for hazardous roadway, curve alignment re-examination, and increased traffic enforcement density are suggested. Collaboration among the roadway authorities, vehicle industry, and medical systems for a timely rescue is also advised. In addition, the attention to crashes at intersections and on local roads is a promising intervention for motorcycle riders.