Effect Of Vertical Alignment Research Articles

Effects of Vertical Alignment of Leg on the Knee Trajectory and Pedal Force during Pedaling

Objective: This study evaluated the vertical and horizontal forces in the frontal plane acting on a pedal due to the vertical alignment of the lower limbs. Method: Seven male subjects (age: 25.3 ± 0.8 years, height: 175.4 ± 4.7 cm, weight: 74.7 ± 14.2 kg, foot size: 262.9 ± 7.6 mm) participated in two 2-minute cycle pedaling tests, with the same load and cadence (60 revolutions per minute) across all subjects. The subject``s saddle height was determined by the height when the knee was at 25° flexion when the pedal crank was at the 6 o``clock position (knee angle method). The horizontal force acting on the pedal, vertical force acting on the pedal in the frontal plane, ratio of the two forces, and knee range of motion in the frontal plane were calculated for four pedaling phases (phase 1: 330~30°, phase 2: 30~150°, phase 3: 150~210°, phase 4: 210~330°) and the complete pedaling cycle. Results: The range of motion of the knee in the frontal plane was decreased, and the ratio of vertical force to horizontal force and overall pedal force in the complete cycle were increased after vertical alignment. Conclusion: The ratio of vertical force to horizontal force in the frontal plane may be used as an injury prevention index of the lower limb.

Surface Vertical Alignment Effect on the Morphology of Liquid Crystal Optical Devices

The effect of liquid crystal (LC) vertical alignment on phase separation dynamics of liquid crystal optical devices with different cell gaps is investigated in this paper. As the cell gap increases, the surface effect on the bulk LC droplets is reduced due to the longer distance. It is found in this experiment that the vertical alignment film can influence the LC droplets in the middle of the gap, and in the meanwhile the surface effect is not too strong to disturb phase separate. In that case, the LC droplets separate at a fixed position during phase separation and also can flow to form good morphology. The surface vertical alignment has a significant effect on the morphology of liquid crystal optical devices.

사이클 페달링 시 웨지를 이용한 하지 수직정렬이 무릎 궤적 및 페달링 파워, 속도에 미치는 영향

사이클 페달링 시 웨지를 이용한 하지 수직정렬이 무릎 궤적 및 페달링 파워, 속도에 미치는 영향

The electro-optical characteristics of liquid crystal device in multi-component liquid crystal mixture system with non-contact photo-induced vertical alignment mode

In previous studies, we mixed photo-curable acrylic pre-polymer into negative dielectric anisotropy nematic type liquid crystal (N-type LC, NLC) to obtain a NLC/photo-curable acrylic pre-polymer mixture solution (NLC mixture system). After irradiation with UV light of fixed intensity, we successfully fabricated copolymer films with vertical alignment effect among the LC molecules. In this study, we propose a new type of multi-component LC mixture system by mixing chiral smectic type (SmA*) LC with homeotropic texture into NLC/photo-curable acrylic pre-polymer mixture system (NSLC mixture system). Our experimental results revealed that this SmA* LC exhibited the vertical alignment effect associated with LC molecules in the auxiliary LC mixture system. Moreover, we also discovered that altering the main chain type biphenol acrylic pre-polymer had drastic impact on the contrast ratio (CR) of the LC mixture system, with an increase of as much as 73%. More importantly, adding the SmA* LC can evidently increase the anchoring energy of the alignment film surface. We also further performed measurements, analyses, and discussions of electro-optical properties of devices fabricated from the new LC mixture systems.

Assessment of the design of reverse horizontal curves to accommodate heavy vehicles based on simulation

Current geometric design policies use passenger cars as design vehicles, while truck operational and dynamic characteristics are not included or not addressed consistently. Furthermore, critical geometric design parameters such as horizontal curves radii are determined without consideration of the effect of vertical alignment. The objective of this work is to investigate whether critical sections such as reverse horizontal curves with spiral curves, can accommodate typical heavy vehicles with safety. The analysis was focused on rural and suburban two-lane roads with undivided pavement that produce the largest accident rates. By means of road - driver - simulation system developed in TruckSim, the vehicle dynamic response to inputs from the immediate environment is analyzed, while same kind of outputs that might be measured with physical tests involving instrumented vehicles are calculated and plotted. Results indicated that horizontal curves minimum radii that are implemented according to several design criteria, can not be used in conjunction with the allowed interval of grades, and that the table of minimum radii must comprehend a limitation for the applicable grade. Otherwise, exclusively speed limits depending on the geometry or larger radii must be used in order to adequately accommodate heavy vehicles.

Effect of vertical alignment of ladle shroud on transient steel quality output from multistrand tundish

Slight misalignments of the ladle shroud in a multistrand continuous casting tundish can lead to significant differences in the amounts of slag entrained into individual moulds during transient operations. In this full scale water modelling work, the effects of ladle shroud alignment on steel quality was measured in terms of ‘slag’ entrainment into the individual moulds. The ladle shroud was purposefully biased by about 4–5° off vertical, and the numbers of ‘slag particles’ entering individual strands of the four‐strand billet caster were measured during a ladle change and compared with the no bias condition. Given the great sensitivity of steel quality to this slight misalignment during a ladle change, possible remedial actions are discussed for equivalent steel plant operations.

The electro-optical characteristics and applicability evaluation of a photo-induced vertical alignment negative-type liquid crystal/photo-curable acrylic pre-polymer mixture system mixed with chiral smectic A phase liquid crystal

In this study, we have investigated newly synthesised chiral smectic A (SmA*) liquid crystals (LCs) with a lactic acid structure with polarised optical microscopy (POM). We started cooling from the clear point until a SmA* phase emerged as the temperature dropped to the range 55.7–88.6°C. At this point, the alignment of the LC molecules resulted in a homeotropic texture. To take advantage of this characteristic, we then mixed the SmA* LC into a negative dielectric anisotropy nematic-type liquid crystal (NLC)/photo-curable acrylic pre-polymer mixture system (the NLC mixture system) with photo-induced vertical alignment, to realise the vertical alignment effect among the NLC molecules. This multi-component LC mixture system gave rise to a special, unknown twist grain boundary AX (TGB AX *) phase with rather broad temperature range, which maintained its helix structure even after crystallisation. In addition, we also utilised the electrical field induced molecular tilt effect (the electroclinic effect) within the SmA* LC to improve the response time of the LC device and gray-scale capability of the NLC mixture system. We further observed this multi-component LC mixture system after ultraviolet light irradiation treatment with POM, to investigate the alignment of the LC molecules, device display and electro-optical properties.

Electro-Optical Characteristics of Vertical Alignment Cell by Ion-Beam Exposure on the SiC Thin Film Layer

We studied the electro-optical (EO) characteristics and nematic liquid crystal (NLC) aligning capabilities with the new alignment material of the Silicon Carbide (SiC) thin film using two kinds of ion beam (IB) gun. The SiC thin film exhibits good chemical and thermal stability. A vertical alignment of nematic liquid crystal by atomic beam exposure on the SiC thin film surface was achieved via all IB exposure system. The generated NLC tilt angle is about 87° using Kaufman type ion gun. The about 88° of stable tilt angle was achieved with incident angle of 10° using duoPIGatron type ion gun. An excellent voltage-transmittance (V-T) and response time curve of the IB-aligned VA-LCD using duoPIGatron type ion gun was observed. The V-T hysteresis characteristics of IB-aligned VA-LCD are almost the same as that of the rubbing-aligned VA-LCD. Consequently, the vertical alignment effect of liquid crystal and the good EO characteristics by the atomic beam alignment method on the SiC thin film layer can be achieved.

Effects of Vertical Alignment of Liquid Crystals on Rubbed Polymer Surfaces Using Transparent Electrodes

We investigated the liquid crystal (LC) aligning capabilities and electrooptical characteristics of transparent Al-doped ZnO (ZnO:Al) electrodes substituting indium tin oxide (ITO) electrodes. Experimental results show that a uniform vertical LC alignment and a large pretilt angle were achieved using the ZnO:Al electrodes. The vertical alignment mode based on the ZnO:Al electrodes showed appropriate electrooptical characteristics and a high transparency in comparison with that based on the ITO electrodes. These results indicate that the transparent ZnO:Al electrodes of liquid crystal displays could substitute the ITO electrodes.

Vertical Alignment of Nematic Liquid Crystal on the SiC Thin Film Layer with Ion-beam Irradiation

We studied the nematic liquid crystal (NLC) aligning capabilities using the new alignment material of the SiC (Silicon Carbide) thin film. The SiC thin film exhibits good chemical and thermal stability. The good thermal and chemical stability make SiC an attractive candidate for electronic applications. A vertical alignment of nematic liquid crystal by atomic beam exposure on the SiC thin film surface was achieved. The about of stable pretilt angle was achieved at the range from of incident angle. Consequently, the vertical alignment effect of liquid crystal electro-optical characteristic by the atomic beam alignment method on the SiC thin film layer can be achieved.

Vertical Alignment of Nematic Liquid Crystal by Rubbing-Free Method on the SiC Thin Film Layer

We studied the nematic liquid crystal (NLC) aligning capabilities using the new alignment material of the silicon carbide (SiC) thin film. The SiC thin film exhibits good chemical and thermal stability. The good thermal and chemical stability make SiC an attractive candidate for electronic applications. A vertical alignment of nematic liquid crystal by atomic beam exposure on the SiC thin film surface was achieved. The about 87° of stable pretilt angle was achieved at the range from 30 to 45° of incident angle. The good LC alignment is maintained by the atomic beam alignment method on the SiC thin film surface until annealing temperature of 300 °C. Consequently, the vertical alignment effect of liquid crystal and the good thermal stability by the atomic beam alignment method on the SiC thin film layer can be achieved.

Design radius requirements for simple horizontal curves on three-dimensional alignments

Current North American design guides have established mathematical relationships to calculate the minimum radius required for horizontal curves as a function of design speed, maximum superelevation, and maximum side friction. For three-dimensional (3-D) alignments, the design guides consider the alignment as two separate horizontal and vertical alignments and consequently ignore the effect of vertical alignment. This paper evaluates the effect of vertical alignment on minimum radius requirements using computer simulation, with a focus on trucks. For 3-D alignments, the results showed that existing design guidelines for minimum radius need to be increased by as much as 20% to achieve the same comfort limit on flat horizontal curves. It is interesting to note that in some cases truck rollover occurred before the side-friction comfort level is reached. This indicates the need for developing a different design control for trucks on 3-D alignments than the comfort criterion used for passenger cars on flat horizontal curves. Based on the simulation results, mathematical models for design radius requirements for passenger cars and trucks were developed.Key words: geometric design, horizontal curve radius, three-dimensional alignments, vehicle stability.

Effect of Vertical Alignment on Driver Perception of Horizontal Curves

The perception of the driver of the road features ahead is an important human factor that can considerably affect traffic safety and design consistency, and should be addressed in road design. An erroneous perception of the road can lead to actions that may compromise traffic safety. Previous studies have shown that combined horizontal and vertical alignments can cause a wrong perception of the horizontal curvature. In this paper, the hypothesis that the perception of the driver of the horizontal curvature is affected by the overlapping vertical alignment is examined analytically. Computer animation was selected as a three-dimensional presentation method of the road perspective, and was found to produce a realistic view of the road. A sample of drivers was interviewed to determine the radius of a horizontal curve on a level grade that would look equal to a radius of a horizontal curve overlapping with a vertical curve. The statistical analysis showed that the horizontal curvature looked consistently sharper when it overlapped with a crest curve and consistently flatter when it overlaps with a sag curve. Field measurements of operating speed profiles on a selected sample of combined alignments confirmed that, for the selected sample of alignments, driver behavior on horizontal curves depended on the overlapping vertical curve rather than the vertical grade of the approach tangent.

Fabrication and characteristics of field emitter using carbon nanotubes directly grown by thermal chemical vapor deposition

We experimentally present the effects of vertical alignment and density of carbon nanotubes on the emission current level. For practical display application, we have fabricated the triode type emitter using directly grown nanotubes as emission tip, and characterized their basic field emission properties. The triode type emitter exhibited a turn-on voltage of 37 V and an anode current density of 1.7 μA with gate voltage at 47 V. The vertical alignment of nanotubes does not play a key role in improving the emission properties in triode type nanotubes emitter.

MBE Growth and Characterization of Composite InAlAs/In(Ga)As Vertically Aligned Quantum Dots

ABSTRACTIn the present work we study the effect of vertical alignment in the quantum dot array formed by successive deposition of several rows of InAlAs and InGaAs quantum dots separated by thin AIGaAs spacer layers. Transmission electron microscopy and photoluminescence studies revealed that the InAlAs QDs characterized by high areal density force InGaAs to be transformed into the denser array as compared to the case of spontaneous transformation. Using denser array of composite quantum dots in the active region of a diode laser leads to the increase in modal gain, decrease in internal loss, and decrease in the threshold current density for short cavity diodes. Room temperature continuous wave output power as high as 3.3 W at 0.87 µm is achieved.

Effect of vertical alignment on continuous‐phase axial mixing in a pilot liquid/liquid spray column

Effect of vertical alignment on continuous‐phase axial mixing in a pilot liquid/liquid spray column

Effect of vertical alignment on the performance of bubble and foam fractionation columns

Effect of vertical alignment on the performance of bubble and foam fractionation columns