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Daytime visibility aspects under alternative use of headlamps

ARTEB-Carlos Alberto Leite de Moura
PRIME ONE-Paulo Victor S. Pingueiro
  • Technical Paper
  • 2019-36-0072
Published 2020-01-13 by SAE International in United States
Daytime visibility represents one of the most important themes in automotive safety. Some accidents, especially frontal collisions, used to occur as a result of a bad recognition of vehicle presence. In order to keep vehicles more visible during the day, there is a luminous device called Daytime Running Lamp (DRL). Nowadays DRL is not mandatory in Brazil, but it will be in 2021 for new vehicles. As with any situation that involves technological transitions, some questions appear, among them: how to equalize the market, in terms of daytime visibility, considering newer and older vehicles together? How to improve visibility in older vehicles that were not designed with DRL? The answer maybe lies in the alternative usage of automotive headlamps. Among other facts, one luminous device for two functions can result in safety improvements without unexpected investments. Therefore, how can this technically be achieved? By CONTRAN 667, that has adopted North America references, including luminous devices according to FMVSS, it is possible to use a low beam or a high beam dimmed to a maximum 7000…
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Effect of pressure cycling on gas exchange in a transparent fuel injector

Sandia National Laboratories, 7011 East Ave, 94550 Livermore-Paul M. Abers, Emre Cenker, Koji Yasutomi, Joonsik Hwang, Lyle M. Pickett
  • Technical Paper
  • 2019-01-2280
Published 2019-12-19 by SAE International in United States
Gas ingested into the sac of a fuel injector after the injector needle valve closes is known to have crucial impacts on initial spray formation and plume growth in a following injection cycle. Yet little research has been attempted to understand the fate sac gases during pressure expansion and compression typical of an engine. This study investigated cavitation and bubble processes in the sac including the effect of chamber pressure decrease and increase consistent with an engine cycle. A single axial-hole transparent nozzle based on the Engine Combustion Network (ECN) Spray D nozzle geometry was mounted in a vessel filled with nitrogen, and the nitrogen gas pressure was cycled after the end of injection. Interior nozzle phenomena were visualized by high-speed longdistance microscopy with a nanosecond pulsed LED back-illumination. Experimental results showed that the volume of gas in the sac after the needle closes depends upon the vessel gas pressure. Higher back pressure results in less cavitation and a smaller volume of non-condensable gas in the sac. But a pressure decrease mimicking the expansion stroke…
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Enhancing Flight Path Separation to Reduce Bird Strikes with Ultraviolet Radiation

SAE International Journal of Aerospace

Lite Enterprises, USA-Donald J. Ronning
  • Journal Article
  • 01-12-02-0005
Published 2019-10-29 by SAE International in United States
In the autumn of 2018, a pilot study using a prototype (PAR46 size) landing light that incorporated ultraviolet light emitting diodes (UVLEDs) was attached on a one-quarter scale remote controlled (RC) plane. The plane was flown in the direction of birds to measure their behavioral response to the approaching plane with landing lights either turned ON or OFF. Data were collected from multiple sources including cameras on the plane and the ground and a bird radar unit to measure the flight path separation between the plane and the birds. The purpose of this study was to determine the effectiveness of using UVLEDs integrated into a PAR46 landing light to trigger bird avoidance behavioral responses that would increase flight path separation to reduce the incidence of bird strikes. The findings showed the mean distance of the avoidance response was statistically significantly greater when the PAR46 landing light with UVLEDs was turned ON versus OFF. Field test data were used to create a three-variable model based upon recent neuroscience research corresponding to visual image capture, retinal neural…
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Vision Based Surface Roughness Characterization of Flat Surfaces Machined with EDM

BSA Crescent Institute of Science & Technology-Mahashar Ali, Siddhi Jailani, Mangalnath Anandan, Vignesh Pavithran
Vellore Institute of Technology-Murugan Mariappan
Published 2019-10-11 by SAE International in United States
Surface roughness measurement is an important one in any manufacturing next to dimensions. In this investigation, a vision system and image processing tools were used to develop reliable surface roughness characterization technique for Electrical Discharge Machined surfaces. A CMOS camera with red LED light source were used for capturing images of EDMed surfaces. A separate signal vector generated for all the images from its image pixel intensity matrices. The mean, skewness and kurtosis were obtained from the signal vector. The mean, skewness and kurtosis of the images signal vector correlates very well with the stylus measured hybrid roughness parameters Rda and Rdq. Hence the technique may be preferred for online surface roughness characterization of Electrical Discharge Machined (EDMed) surfaces.
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How to Use Rotary Encoders to Quickly Convert Mechanical Rotation into Digital Signals

  • Magazine Article
  • TBMG-35291
Published 2019-10-01 by Tech Briefs Media Group in United States

In the digital age, the measurement of rotation of a mechanical shaft on a motor or a rotating instrument knob needs to be done quickly and efficiently. Analog methods such as potentiometers and rotating switches are being replaced by rotary encoders that directly digitize rotary movement, but designers need to be able to appreciate the differences among various encoder types and accurately interpret their digital outputs.

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Photometric and Colorimetric Measurement Procedures for Airborne Electronic Flat Panel Displays

A-20A Crew Station Lighting
  • Aerospace Standard
  • ARP4260B
  • Current
Published 2019-09-17 by SAE International in United States
This SAE Aerospace Recommended Practice (ARP) contains methods used to measure the optical performance of airborne electronic flat panel display (FPD) systems. The methods described are specific to the direct view, liquid crystal matrix (x-y addressable) display technology used on aircraft flight decks. The focus of this document is on active matrix, liquid crystal displays (LCD). The majority of the procedures can be applied to other display technologies, however, it is cautioned that some techniques need to be tailored to different display technologies. The document covers monochrome and color LCD operation in the transmissive mode within the visual spectrum (the wavelength range of 380 to 780 nm). These procedures are adaptable to reflective and transflective displays paying special attention to the source illumination geometry. Photometric and colorimetric measurement procedures for airborne direct view CRT (cathode ray tube) displays are found in ARP1782. Optical measurement procedures for airborne head up displays (HUDs) can be found in ARP5287. Generally, the procedures describe manual single point measurements. The individual procedures may be readily incorporated into automated testing equipment…
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Flight Deck Lighting for Commercial Transport Aircraft

A-20A Crew Station Lighting
  • Aerospace Standard
  • ARP4103A
  • Current
Published 2019-09-17 by SAE International in United States
This document recommends design and performance criteria for aircraft lighting systems used to illuminate flight deck controls, luminous visual displays used for transfer of information, and flight deck background and instrument surfaces that form the flight deck visual environment. This document is for commercial transport aircraft except for applications requiring night vision compatibility.
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Organic Carbon-Nitride Semiconductor

  • Magazine Article
  • TBMG-35128
Published 2019-09-01 by Tech Briefs Media Group in United States

Some organic materials cannot be utilized similarly to silicon semiconductors in optoelectronics. Whether in solar cells, light-emitting diodes, or in transistors, what is important is the bandgap, i.e. the difference in energy level between electrons in the valence band (bound state) and the conduction band (mobile state). Charge carriers can be raised from the valence band into the conduction band by means of light or an electrical voltage. This is the principle behind how all electronic components operate. Bandgaps of one to two electron volts are ideal.

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Requirements for Plastic Encapsulated Discrete Semiconductors in Space Applications

CE-12 Solid State Devices
  • Aerospace Standard
  • AS6294/3
  • Current
Published 2019-08-07 by SAE International in United States
This document establishes the requirements for screening, qualification, and lot acceptance testing of Plastic Encapsulated Discrete Semiconductors (PEDS) for use in space application environments. The scope of this document is intended for standard silicon based technology only, but the process and methodology described within can be adopted for other technologies such as Silicon Carbide, Gallium Nitride, and Gallium Arsenide. However, when non-silicon based technology parts are being used, the device characterization shall be modified, and it is recommended to use available industry standards based upon published research/testing reports for those technology to address applicable physics of failure.
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Double-Sided Si(Ge)/Sapphire/III-Nitride Hybrid Structures

  • Magazine Article
  • TBMG-34888
Published 2019-08-01 by Tech Briefs Media Group in United States

NASA Langley Research Center has developed a double-sided Si(Ge)/ Sapphire/III-Nitride hybrid structure. This technology uses both sides of a sapphire wafer to build device structures — on one side, making either Si or SiGe devices and on the other side, making III-Nitride device structures (e.g. GaN, InGaN, AlGaN).