1,607 research outputs found

    Herbicide and Application Timing Effects on Windmillgrass (Chloris verticillata) Control

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    Windmillgrass (Chloris verticillata Nutt.) populations commonly infest turfgrass systems in the midwest, which result in aesthetically unacceptable turfgrass stands. Research trials were initiated in 2017 and 2018, in Onaga and Junction City, KS, to determine windmillgrass control with various single herbicide applications at dif­ferent application timings. Pylex (topramezone) resulted in more than 80% wind­millgrass control 8 weeks after spring and summer application

    Influence of Herbicide Combinations and Sequential Applications on Windmillgrass (Chloris verticillata) Control

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    Windmillgrass (Chloris verticillata Nutt.) populations commonly infest turfgrass systems in the midwest, which result in aesthetically unacceptable turfgrass stands. Pylex (topramezone) and Acclaim Extra (fenoxaprop) have resulted in fair control of windmillgrass with single applications. For adequate control of windmillgrass, a sequential application of Tenacity (mesotrione), three weeks after the initial application, is recommended. Additionally, studies have shown the addition of triclopyr to HPPD inhibitor herbicides increases windmillgrass control in a controlled environ­ment. Field experiments were initiated in 2018, at the Kansas State University Rocky Ford Turfgrass Research Center in Manhattan, KS, to determine the influence of herbicide combinations with the addition of triclopyr and sequential applications on windmillgrass control

    Herbicide and Application Timing Effects on Windmillgrass Control

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    Windmillgrass (Chloris verticillata Nutt.) populations commonly infest turfgrass systems in the midwest, which result in aesthetically unacceptable turfgrass stands. Research trials were initiated in 2017 in Onaga and Junction City, KS, to determine windmillgrass control with various single herbicide applications at multiple application timings (spring, summer, and fall). Data collection for research trials consisted of visual percent windmillgrass cover (0–100%), line intersect analysis on four-inch spacing, normalized difference vegetation index (NDVI) (0 to 1 scale), and windmillgrass seedhead counts. Initial observations resulted in greater windmillgrass control with summer applications compared to fall applications. Pylex (topramezome) resulted in 80% windmillgrass control 8 weeks after summer application. Initial results indicate alternative herbicides options for windmillgrass control

    Assessing the Elastic Moduli of Pavement Marking Tapes using the Tape Drape Test

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    Temporary pavement marking (TPM) tape adhesion with roadway surfaces is critical for tape performance. The two main TPM performance issues both stem from the adhesive strength. Weak adhesion results in premature detachment and excessive adhesion requires extensive removal processes that often leave ghost markings, both of which can cause dangerous confusion in road construction zones. Tape adhesion is directly related to the elastic modulus (E) role= presentation \u3e(E) of TPM tapes. Thus, accurate characterization of E role= presentation \u3eE before tape installation is essential to fully understand and predict the adhesion performance and ultimately the durability of TPMs. To determine the most appropriate E role= presentation \u3eE characterization technique for three different commercial TPM tape brands, two commonly used techniques—tensile and three-point bend testing—were compared with a less common technique, the Peirce cantilever testing or “Tape Drape Test” (ASTM D1388-18). The Tape Drape Test was the only method that accurately characterized E role= presentation \u3eE of tapes with raised surface features. Measured E role= presentation \u3eE values from tensile and three-point bend testing showed significant variation caused by the structural features of the tapes. The Tape Drape Test, which can be implemented quickly in the field before tape installation with little equipment, effectively characterized E role= presentation \u3eE for all the tapes to inform tape adhesion performances and installation procedures

    Polymerization initated at sidewalls of carbon nanotubes

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    The present invention is directed to aryl halide (such as aryl bromide) functionalized carbon nanotubes that can be utilized in anionic polymerization processes to form polymer-carbon nanotube materials with improved dispersion ability in polymer matrices. In this process the aryl halide is reacted with an alkyllithium species or is reacted with a metal to replace the aryl-bromine bond with an aryl-lithium or aryl-metal bond, respectively. It has further been discovered that other functionalized carbon nanotubes, after deprotonation with a deprotonation agent, can similarly be utilized in anionic polymerization processes to form polymer-carbon nanotube materials. Additionally or alternatively, a ring opening polymerization process can be performed. The resultant materials can be used by themselves due to their enhanced strength and reinforcement ability when compared to their unbound polymer analogs. Additionally, these materials can also be blended with pre-formed polymers to establish compatibility and enhanced dispersion of nanotubes in otherwise hard to disperse matrices resulting in significantly improved material properties. The resultant polymer-carbon nanotube materials can also be used in drug delivery processes due to their improved dispersion ability and biodegradability, and can also be used for scaffolding to promote cellular growth of tissue

    Effects of Normobaric Hypoxia on Oculomotor Dynamics of Aviator Students during a Simulated Flight Task

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    Hypoxia occurs when the body\u27s tissues are unable to obtain adequate oxygen supply and is the primary environmental factor present when pilots are exposed to increasing altitude levels. Hypoxia leads to impaired vision, cognition, and motor control function, which can negatively affect performance and become deadly if a pilot becomes incapacitated. Thus, objective identification of early-onset hypoxia is critical to increase the time of useful consciousness and prevent physiological episodes. Of the few studies utilizing eye-tracking, there is disagreement and mixed results concerning saccadic eye metrics as a means to measure and detect hypoxia. Therefore, the purpose of this study was to investigate saccadic velocity changes driven by acute normobaric hypoxia. Using a noninvasive infrared-based eye-tracking device, we recorded saccadic average peak velocity during flight tasks at simulated altitudes of 0 ft, 12,500 ft, and 19,000 ft. No changes were observed in saccadic average peak velocity among different altitude exposures. As time on task increased, saccadic average peak velocity decreased, suggesting that eye metrics can serve as an indicator of mental fatigue

    The Use of Molecular Pathway Inhibitors in the Treatment of Osteosarcoma

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    Presently, the 5-year survival rate for metastatic osteosarcoma remains low despite advances in chemotherapeutics and neoadjuvant therapy. A majority of the morbidity and nearly all of the mortality in osteosarcoma rely not in the primary disease but in the metastatic disease. The pursuit of novel molecular therapies is attractive due to their targeted ability to combat metastasis. Unlike traditional chemotherapy agents, which work by targeting rapidly dividing cells, targeted therapies may spare normal cells and decrease the adverse effects of chemotherapy by targeting specific pathways. Here, we discuss key molecular pathways in osteosarcoma and their ability to be modulated for the goal of eradication of primary and metastatic disease. We focus specifically on the aldehyde dehydrogenase (ALDH), epidermal growth factor receptor (EGFR), and insulin-like growth factor-1 receptor (IGF-1R) pathways

    Pilot Visual Detection of Small Unmanned Aircraft Systems (sUAS) Equipped with Strobe Lighting

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    When operating under Visual Flight Rules, pilots primarily rely on visual scanning to avoid other aircraft and airborne collision threats. Records from the Federal Aviation Administration indicate that near encounters with unmanned aircraft are on the rise, reaching 1,761 reported unmanned aircraft system (UAS) sightings or near-misses in 2016. This study sought to assess the effectiveness of pilot visual detection of UAS platforms that were equipped with strobe lighting. A sample of 10 pilots flew a general aviation aircraft on a scripted series of five intercepts with a small UAS (sUAS) that was equipped with strobe lighting. Participants were asked to indicate when they visually detected the unmanned aircraft. Geolocation information for both the aircraft and sUAS platform was compared to assess visibility distance. Findings were used to evaluate the efficacy of daytime strobe lighting as a method to enhance pilot sUAS detection, visibility, and collision avoidance. Participants detected the unmanned aircraft during 7.7% of the intercepts. Due to a lack of data points, the authors were unable to conclusively determine if strobe lighting improved UAS visual detection. The authors recommend further research to explore the effectiveness of using sUAS-mounted strobe lights for nighttime visual detection

    Detecting and Assessing Collision Potential of Aircraft and Small Unmanned Aircraft Systems (sUAS) by Visual Observers

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    Visual observers are used to assist the Remote Pilot with maintaining sight of the unmanned aircraft as well as scanning the surrounding airspace for potential collision hazards. The purpose of this study was to examine the effectiveness of visual observers in detecting an intruding general aviation aircraft approaching the small unmanned aircraft system (sUAS) operations area. The study sought to determine the effectiveness of sUAS visual observers in detecting a general aviation aircraft collision hazard with a sUAS. Ten participants were asked to perform visual observer duties in support of a sUAS operation. Participants were asked to indicate when they were able to hear and see an aircraft that conducted a scripted series of close intercepts with a sUAS. Additionally, researchers assessed each visual observer’s ability to accurately judge the closure rate of the aircraft, by estimating the duration from initial sighting until the aircraft would intercept the airborne sUAS platform. Geolocation data from both the aircraft and sUAS were time correlated and compared to determine estimation accuracy. Findings were used to formulate operational recommendations to improve visual observer performance in detecting and assessing intruder aircraft collision potential

    Pilot Visual Detection of Small Unmanned Aircraft on Final Approach during Nighttime Conditions

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    In December 2020, the Federal Aviation Administration (FAA) announced the release of a new final rule, permitting operators of small unmanned aircraft systems (sUAS) to perform routine night operations. Public comments to the Notice of Proposed Rulemaking indicated potential safety concerns regarding a pilot’s ability to spot a low-altitude sUAS during nighttime conditions. Leveraging data from the FAA’s UAS Sighting Report Database, the research team evaluated the significance of aircraft encounters with UAS at night. Researchers conducted an inflight experiment in which 10 pilots performed an instrument approach to airport during nighttime conditions in which a multi-rotor sUAS presented a potential collision hazard. The sUAS was equipped with lighting visible for 3 miles with a sufficient flash rate to avoid a collision, as specified by the new regulation. Participants performed five approaches, with the sUAS flying different scripted encounter profiles. Participants were asked to indicate when they visually spotted the sUAS, with sighting data recorded via an onboard observer. Geolocation information from both the aircraft and sUAS were compared at the time of each reported sighting to assess visibility distance and orientation. The sUAS was successfully spotted during 30 percent (n = 12) of the testing passes. Hovering sUAS were spotted at the same rate as moving sUAS, however, sUAS in motion were spotted at a much greater range. Researchers noted disproportionately higher spotting rates occurred when the sUAS was oriented on the starboard side of the aircraft vs. the port side. It is believed that airport lighting systems may have obscured or otherwise camouflaged portside sUAS encounters. When asked to estimate distance to an encountered sUAS, most participants underestimated, perceiving the sUAS to be much closer than reality. Additionally, the researchers assessed the potential for the participants to initiate evasive maneuvers, based on the distance and closure rate of the aircraft and sUAS at the time of sighting. Based on the FAA’s Aircraft Identification and Reaction Time Chart, collision avoidance would only have been successful during 15 percent of encounters (n = 6). The research team recommends Remote Pilots employ vigilant traffic awareness during nighttime operations, and leverage use of ADS-B (In) technology and monitor Common Traffic Advisory Frequencies to maintain situational awareness—particularly when operating in proximity to airports
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