Measuring Color Perception through Laser Mitigation Coatings on Aircraft Windshields

Ground-based laser illuminations directed towards arriving and departing aircraft have increased in the past decade. A laser aimed at the windshield of an aircraft may distract a pilot and compromise safety. Previous studies provided empirical evidence of laser intensity in the flight deck from ground-based laser illumination events and the potential for adverse effects to flight safety. Most recent studies focused on testing the application of various coatings to aircraft windshields in order to reduce the effects of laser exposure to crewmembers. Safe and efficient flight operations depend on the ability of a pilot to see normal spectrums of color. Therefore, this study used the Ishihara Pseudoisochromatic Plates Color Vision Test to investigate participants’ color perception through an aircraft windshield coated with a photoresponsive nanocomposite film designed to reduce laser intensity from entering a flight deck. This study tested the hypothesis that there were no differences between color vision test scores when conducting trials with coated and non-coated windshields. Participants were individuals who held a current FAA medical certificate and held a minimum of a student pilot certificate (N = 104). Data analysis consisted of a repeated measures design that included within-subjects factors where each of the participants was tested from two trials, each under two conditions: coated and non-coated. The order of trials was altered using a counterbalancing technique which also provided a between-subjects factor. A paired-samples t-test was calculated to compare the mean of error by participants when taking the Ishihara Test through the non-coated windshield to the mean of the error by participants when taking the test through the coated windshield. No significant difference from the non-coated to the coated windshield was found (t(103) = 1.274, p > 0.05, n = 104). Findings suggest that effective color vision can be maintained through photoresponsive nanocomposite coatings

Drain-Engineered Reconfigurable Transistor Exhibiting Complementary Operation

Abstract In this paper, we propose and simulate a multifunctional transistor that exhibits device reconfigurability and realizes both nFET and pFET electrical characteristics when adequately biased. The use of this device will significantly reduce the transistor count in realizing sequential and combinational circuits and will result in highly compact design. The device uses a dual fin structure having a single mid-gap workfunction gate (∼4.65 eV) alongside dual metal (metal-silicide) drain regions. It employs n + / p + - i junctions at the source-channel interface along with the Schottky junctions at the channel-drain interface. In practice, metal-silicides such as erbium/ytterbium silicide (ErSi x /YbSi x ) for the n -drain and platinum silicide (PtSi) for the p -drain can be used as they provide smallest electron and hole Schottkybarrier heights (SBHs). Simulations carried out using calibrated parameters show better drive current (≈ 10 −2 −10 −3 A/ µ m) compared to the quantum tunneling current in simulated stateof-the-art multifunctional devices (≈ 10 −4 − 10 −5 A/ µ m). In addition, butterfly curves show symmetric high (NM H ) and low (NM L ) noise margins of 0.43V and 0.29V for zero and finite SBHs, respectively. The switching characteristics is shown to have an overshoot of ∼0.15 V for realistic SBHs which is then eliminated for the case of zero SBHs. In the last section, it is also demonstrated that a simplified structure having single mid-gap workfunction (∼4.65 eV) drain of Nickel silicide (NiSi) does not hamper the reconfigurability of the device. Index Terms —MOSFET, Multifunctional circuit, CMOS,
Schottky junction.</jats:p

Design of High Temperature Combline Band-pass Filters for Downhole Communications

Abstract The decline of easily accessible reserves pushes the oil and gas industry to drill deeper to explore previously untapped wells. Temperatures in these wells can exceed 210 °C. Cooling and conventional heat extraction techniques are impractical in such a harsh environment. Reliable electronic designs that can sustain high temperature become necessary. This paper presents RF and IF microstrip combline band-pass filters for downhole communications, which can reliably operate up to 250 °C. Both filters are prototyped on a Rogers RO4003C substrate. Measured results at 250 °C show that the RF and IF filters have insertion losses of 4.53 dB and 3.45 dB, respectively. Both filters have stable performance at high temperatures. The maximum insertion loss variation with temperature for the RF filter is 1.88 dB, and bandwidth variation is 1.3 MHz. The maximum insertion loss variation with temperature for the IF filter is 1.48 dB, and bandwidth variation is 0.4 MHz. Return loss for the RF filter is more than 12 dB, and for the IF filter more than 10 dB in the passband. This paper also describes a simple method to find spacing between coupled symmetrical microstrip lines of a combline filter.</jats:p