Polarization Characterization of LEDs by Stokes Parameters Measurements

Stokes parameters have been measured by using a polarimeter consisting of a rotating phase plate before a fixed polarizer for bullet-shaped red, green and blue LEDs at 3 different directions of 0°, 45° and 90° from the principal axis. The degree of polarization is minimum at the observation angle 0° (observed head-on) for all colors as expected but has non-zero values (1-9%). As for the possible cause for the partial polarization, it is likely to be brought by striae inside the transparent epoxy resin that can be easily visible. Data at observation angle 90° have features common for all colors; the degree of polarization is highest, the long axis azimuth of the polarization ellipse is nearly in the horizontal direction, and the ellipticity is small. These features can be explained as follows. At observation angle 90°, only small fraction of the beam emitted nearly horizontally is detected possibly through multireflection (the plane of incidence is in the vertical plane) inside the top- and bottom-surfaces (in the horizontal direction) of the chip substrate. Since the reflectance for s-polarization (horizontal component) is higher than that for p-polarization, the emerging beam becomes horizontally polarized. The hypotheses that geometrical asymmetry generates polarization is experimentally supported.

Controls of Deep-Seated Faults and Folds on Hydrocarbon Fluid Migration and Accumulation in Sedimentary Basins: A Case Study from the Northwestern Sichuan Basin, China

Deep-seated faults and folds of foreland basin systems have become important exploration targets in the recent years because they are crucial in controlling fluid migration and hydrocarbon accumulation. In this study, we analyzed the characteristics and formation history of these structures in the northwestern Sichuan Basin using recently acquired two-dimensional (2D) and three-dimensional (3D) seismic data. The seismic interpretation revealed that the thrust sheets, tectonic wedges, and foredeep were well developed in the northwestern Sichuan Basin from the mountain to the basin. Forward thrusts, fault-bend folds, and wedges are the main types of structures in the thrust sheets and tectonic wedges. The deep-seated faults and folds were easily recognized in the high-resolution 3D seismic data. The imbricate thrust faults that merged into detachment layers of the Lower Cambrian are the main types of structures in the foredeep, and they show a prominent strike-slip influence in the horizontal direction. The formation of these structures in the foredeep in the northwestern Sichuan Basin mainly endured two stages of thrusting, including those during the Middle-to-Late Triassic and Cenozoic. Based on the tectonic evolution and seismic data, we infer that these deep-seated faults and folds in the foredeep may have formed earlier than the northern Longmen Shan fold-and-thrust belts and they may have been initially active in the late of Early Triassic and reactive during the Cenozoic. Furthermore, evaporites in the Lower and Middle Triassic were crucial in forming these structures. The petroleum exploration data suggested that the deep-seated faults can facilitate hydrocarbon accumulation. The thrust faults in the foredeep were more likely to act as migration pathways for fluids instead of sealing barriers along the horizontal direction. The interconnected reservoirs of deep-seated folds possess a great potential to allow large-scale hydrocarbon accumulation. Our study provides a good example for evaluating the hydrocarbon exploration potential in the deeply buried area in the sedimentary basin.

Plume neutralization of ionic liquid electrospray thruster: Better insights from Particle-in-cell modelling

Ionic liquid electrospray thrusters with high specific impulse, high thrust accuracy and low thrust noise are very promising for space gravitational wave detection missions. The plume which may lead to surface charging of solar panels and sensitive spacecraft components is a great concern for the applications of electrospray thruster. Therefore, this paper investigates the plume neutralization process of the ionic liquid electrospray thruster through fully kinetic Particle­in­cell simulations. The unipolarity operation mode is firstly simulated and compared with the experimental measurements. The bipolar operation mode is analyzed by considering the premixing and the separation of positive and negative ion beams. At the same time, the effect of beam spacing on the plume characteristics is investigated. The results show that the plume neutralization of the ionic liquid electrospray thruster is achieved by the spatial and temporal oscillations of the ion beams. In the horizontal direction, the spatial oscillations are caused by the different mass and hence velocities of positive and negative ions. In the vertical direction, the spatial oscillations are mainly because of the non-zero beam spacing. The temporal oscillations may be related to the charge separation induced by the different mass and hence velocities of positive and negative ions. As the beam spacing increases, the amplitude of the electric potential oscillations changes scarcely in the horizontal direction while increases in the vertical direction. The ion temperature goes up with the beam spacing and the deviation of the temperature of beam ions does not exceed 15 eV in the horizontal direction but exceeds 100 eV in the vertical direction. Moreover, the plume divergence half angle and the beam spacing are positively correlated, suggesting that the ionic electrospray thrusters with positive and negative polarity need to be placed as close as possible in the spacecraft.

Evaluation and Analysis of Tractor Driver’s Seat Vibrations without Implements and with Implements during Tillage Process

In day to day operations tractor has to move with tillage implements and without tillage implements. In this work emphasis has been given to compare the effect of vibrations on driver’s seat of tractor while working with implements during tillage and while working without implements. The experiment was conducted in the fields of Punjab (India). During the experiment, first time the tractor was made to move without implements and second time tractor was moving with chisel plough (tillage implement). Both times real time vibration data of driver’s seat was collected with three-axis accelerometer and it was observed that when tractor was moving without implements the vibration amplitude was highest in vertical direction Z as compared to transverse direction Y and horizontal direction X. But when the tractor was moving in the fields with tillage implement (chisel plough) the vibration amplitude was high in transverse direction Y relative to horizontal direction X and vertical direction Z.

Bi-funtional resonance effects of plasmon-induced transparency and Fano-like response using an asymmetry metamaterial resonator consisting of three metallic strips at terahertz frequency

Bi-functional metamaterial resonance device operated at terahertz frequency is designed in this paper. It is composed of three metallic strips, in which two parallel metallic strips having the identical dimensions are arranged in the longitudinal direction, and a single metallic strip deviated from the center position is arranged in the horizontal direction. Bi-functional resonance effects of plasmon-induced transparency (PIT) and Fano-like response are simultaneously obtained in this simple metamaterial structure. The formation mechanisms of the two resonance effects are analyzed with the aid of the near-field distributions and the dependence of structure parameters on the whole resonance performance. Results further show that the metallic strip placed horizontally plays an important role in adjusting the resonance response of the metamaterial resonator. More importantly, when the deviation value of the metallic strip in the horizontal direction exceeds a certain amount, for example 10 μm, the metamaterial resonator can realize the effective regulation from bi-functional resonance to single-functional PIT effect. Our proposed structure can be used as valuable platform for ideas to inspire the design of novel electro-optic devices.

Electrical Screening Method of VNAND Flash Channel Hole Bending Defects

A novel electrical screening method of channel hole bending (ChB) defects is proposed for the implementation of high-density vertical NAND (VNAND) flash memory. The ChB defects induces the leakage current between the two adjacent channel holes, which leads to fatal failure in storage systems. Thus, it is one of the key requirements for VNAND mass production to screen ChB defects electrically in advance. In the proposed screening method, a 3D checkerboard (CKBD) pattern is introduced, which consists of alternating programed (‘0’) and inhibited (‘1’) memory cells in a diagonal and horizontal direction. By measuring the leakage current between the channel holes, ChB defects can be successfully detected electrically.

A Comparative Eye Tracking Study of Usability—Towards Sustainable Web Design

Websites are one of the most frequently used communication environments, and creating sustainable web designs should be an objective for all companies. Ensuring high usability is proving to be one of the main contributors to sustainable web design, reducing usage time, eliminating frustration and increasing satisfaction and retention. The present paper studies the usability of different website landing pages, seeking to identify the elements, structures and designs that increase usability. The study analyzed the behavior of 22 participants during their interaction with five different landing pages while they performed three tasks on the webpage and freely viewed each page for one minute. The stimuli were represented by five different banking websites, each of them presenting the task content in a different mode (text, image, symbol, graph, etc.).; the data obtained from the eye tracker (fixations location, order and duration, saccades, revisits of the same element, etc.), together with the data from the applied survey lead to interesting conclusions: the top, center and right sides of the webpage attract the most attention; the use of pictures depicting persons increase visibility; the scanpaths follow a vertical and horizontal direction; numerical data should be presented through graphs or tables. Even if a user's past experience influences their experience on a website, we show that the design of the webpage itself has a greater influence on webpage usability.

Convolutions of Harmonic Mappings Convex in the Horizontal Direction

In this paper, we establish some results concerning the convolutions of harmonic mappings convex in the horizontal direction with harmonic vertical strip mappings. Furthermore, we provide examples illustrated graphically with the help of Maple to illuminate the results.

The Study on Internal Flow Characteristics of Disc Filter under Different Working Condition

A disc filter (DF) is an important component in a micro irrigation system. However, it has a high head loss and low filtration efficiency, which can lead to the inoperability of micro irrigation systems. To improve the filtration ability and to decrease the pressure loss of the irrigation system, it is necessary to internalize the hydraulic characteristics of DFs. In this study, the filter bed of a DF was divided into three parts, i.e., upper, middle, and lower, which were wrapped with a transparent film. The wrapped part was completely blocked. The purpose was to analyze the hydraulic characteristics of different clogged conditions in three types of filters under four types of flows. In addition, we attempted to simulate the filter operation process with computational fluid dynamics, based on two aspects—a macroscopic model and a simplified model. The results showed that the patterns of head loss among all of the DFs was consistent, and the macroscopic model that treated filter bed as a porous medium could express the measured results. The macroscopic models observed that there was a circular flow in the DF, and the flow velocity presented a symmetrical distribution in a horizontal direction. The middle of the filter element appeared in a high-pressure area and demonstrated the highest head loss, which may be the main flow area of the DF, and the inner flow characteristics of the DF were consistent under different conditions. The simplified models showed that the main flow area is near the filter bed in the inner DF, and the flow is tangent to the filter bed between 45 and 90 degrees in a horizontal direction. The uneven distribution of velocity and pressure on the filter bed might be necessary factors to impact filter efficiency.

Analisa Karakteristik Getaran Pada Mesin Asphalt Mixing Plant Tipe Apollo ANP- 1500 Berdasarkan Kapasitas Pembuatan Aspal Jalan Pada Daerah Horizontal, Vertikal Dan Longitudinal Berdasarkan Time Domain

Asphalt mixing plant machine is a tool used to process several materials into road asphalt, where it is necessary to know how to analyze the vibration characteristics of the asphalt mixing plant machine based on the capacity of making asphalt road in horizontal, vertical and longitudinal areas based on the time domain. The research method is carried out by collecting data on the amount of deviation, speed and acceleration that arise due to the processing of several materials so as to produce road asphalt based on differences in the capacity of different asphalt processed. Based on the measurement results, it is found that the highest vibration occurs at the asphalt mixing plant machine seat for a capacity of 60 tons/hour where the magnitude of the deviation is 0.222 mm in the horizontal direction at 100 seconds, the largest velocity is 11.99 mm/s horizontally in the second 40 mm/s and the largest acceleration is 369.7 mm/s2 in the horizontal direction of the 20th second. According to the ISO IS 2372 standard, the vibration of the Apollo ANP-1500 asphalt mixing plant machine enters class IV with a generator capacity above 75 KW, to be more precise (150KVA = 120KW). Then it can be analyzed that the generator vibration falls into the category of "vibration within tolerance limits and is only operated for a limited time" where the highest speed is 11.99 mm/s.