The Experts below are selected from a list of 29214 Experts worldwide ranked by ideXlab platform

Marlan O Scully - One of the best experts on this subject based on the ideXlab platform.

  • insect Flight Velocity measurement with a cw near ir scheimpflug lidar system
    Optics Express, 2020
    Co-Authors: Kai Wang, Rafael Quinterotorres, Robert Brick, Alexei V Sokolov, Marlan O Scully
    Abstract:

    Flight Velocity measurement is an important aspect of insect research that can aid insect identification and facilitate studies and monitoring of insect movements. We propose a novel scheme for the 1-D Flight Velocity measurement of insects, based on a near-IR Scheimpflug lidar system. We implement this new technique and apply it to study insects at the Salter Research Farm, Robertson County, Texas. The resolution property perpendicular to the probing direction of the Scheimpflug lidar system is explored and reveals the capability of retrieving the Velocity component normal to the probing direction of insects passing through the field of view of our system. We observe a shift in wingbeat frequency, which indicates the presence of new insect species during the multi-day measurement. The study on 1-D Flight Velocity reveals a net directional movement of insects, providing supportive evidence of the arrival of a new species.

Jun Du - One of the best experts on this subject based on the ideXlab platform.

  • the analysis of melting and refining process for in Flight particles in supersonic plasma spraying
    Computational Materials Science, 2015
    Co-Authors: Guangxi Zhao, Jun Du
    Abstract:

    Abstract To understand the effect of in-Flight particle behavior so as to improve the coating quality, an accurate description of transport phenomena of particles is essential. For supersonic plasma spraying (SAPS), a three-dimensional computational model is developed to describe the plasma jet coupled with the injection of carrier gas and particles. The heating and melting processes of single particle were also studied by a numerical method. The model treats the particles in the flow as discrete Lagrangian entities that exchange mass, momentum, and energy with the gas. The governing equations for the Reynolds averaged flow parameters were solved using FVM method and the continuity and momentum equations are coupled using the PISO algorithm. The Velocity and temperature of the in-Flight particles were measured by SprayWatch-2i, and the morphology of particles was observed by Scanning Electron Microscope (SEM). Numerical and experimental results showed that, the Velocity and temperature of the in-Flight particles were reached maximum at the spraying distance of 80–100 mm. Particles were melted and broken into small child particles by plasma jet. The small child particles were accelerated to higher in-Flight Velocity by gas flow. Particles were completely melted when the spraying distance about of 95 mm at the time of 0.35 ms. Numerical results were compared with the experimental measurements and a good agreement has been achieved.

Luo Zhao - One of the best experts on this subject based on the ideXlab platform.

  • the influence of particle in Flight properties on the microstructure of coatings deposited by the supersonic atmospheric plasma spraying
    Ceramics International, 2013
    Co-Authors: Jingda Tang, Luo Zhao
    Abstract:

    Abstract In this work, yttria-stabilised zirconia (YSZ) coatings were deposited by a high-efficiency supersonic atmospheric plasma spraying (SAPS) system. During spraying, the in-Flight properties (including Velocity and surface temperature) of the sprayed particles were diagnosed on-line by a commercially available Spray Watch 2i system positioned normal to the spraying axis. The effect of the in-Flight properties of the sprayed particles on the microstructure of the coatings was studied, with the aim of achieving improved knowledge on the accurate control of their coating quality. The VT value, defined as a function of the in-Flight Velocity of the particles and the surface temperature of the substrate, was observed to be directly proportional to the reciprocal of the porosity and structure uniformity of the coatings, which indicated that the structure of the SAPS-coatings can be tailored by adjusting the VT value of the sprayed particles.

Hyung-jun Kim - One of the best experts on this subject based on the ideXlab platform.

  • the effects of powder properties on in Flight particle Velocity and deposition process during low pressure cold spray process
    Applied Surface Science, 2007
    Co-Authors: Xianjin Ning, Jaehoon Jang, Hyung-jun Kim
    Abstract:

    In cold spray process, impacting Velocity and critical Velocity of particles dominate the deposition process and coating properties for given materials. The impacting Velocity and critical Velocity of particles depend on the powder properties and cold spray conditions. In the present study, the in-Flight particle Velocity of copper powder in low pressure cold spraying was measured using an imaging technique. The effects of particle size and particle morphology on in-Flight particle Velocity and deposition efficiency were investigated. The critical Velocity of copper powder was estimated by combining the in-Flight particle Velocity and deposition efficiency. The effect of annealing of feedstock powder on deposition and critical Velocity was also investigated. The results showed that the irregular shape particle presents higher in-Flight Velocity than the spherical shape particle under the same condition. For irregular shape particles, the in-Flight Velocity decreased from 390 to 282 m/s as the particle size increases from 20 to 60 μm. Critical velocities of about 425 m/s and more than 550 m/s were estimated for the feedstock copper powder with spherical and irregular shape morphology, respectively. For the irregular shape particles, the critical Velocity decreased from more than 550 to 460 m/s after preheating at 390 °C for 1 h. It was also found that the larger size powder presents a lower critical Velocity in this study.

İkbal Eski - One of the best experts on this subject based on the ideXlab platform.

  • Neural network and fuzzy logic-based hybrid attitude controller designs of a fixed-wing UAV
    Neural Computing and Applications, 2021
    Co-Authors: Şaban Ulus, İkbal Eski
    Abstract:

    In this paper, a mini unmanned aerial vehicle (UAV) is planned to be used in applications such as spraying pesticide and weed control in agricultural areas. According to literature review, proportional + integral + derivative (PID) structure is used to control many of these UAVs. This controller is insufficient against uncertain weather conditions and disturbance effects. In this study, many different control techniques are evaluated to select the controller structure that can respond to these uncertainties. The structure having the best result was chosen as the UAV controller. Ultrastick-25e mini UAV model is used to control the roll and yaw angle lateral dynamics. State-space presentation of the UAV longitudinal and lateral dynamics is explained, and it is just obtained for the lateral dynamics to control the attitude of the UAV under 60 km/h Flight Velocity condition. According to the aileron and rudder inputs, lateral dynamics simulations have successfully done by using five different controller methods such as classical PID, artificial neuro-fuzzy inference system (ANFIS), fuzzy logic controller, combined ANFIS-PID, and PD-Fuzzy-PI controllers. Moreover, three different input signals are assumed to evaluate the system response. Additionally, transient response and the time performance parameters such as overshoots, peak, rise and settling times, and steady-state error have analyzed for the designed different controllers. The simulated results for the five different controller designs showed that combined PD-fuzzy-PI and ANFIS-PID controllers have more acceptable performance than other controllers at the steady level Flight condition. It is aimed that the simulation findings obtained in this study will contribute to experimental studies.