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Sources of Radiation
Published in Douglas S. McGregor, J. Kenneth Shultis, Radiation Detection, 2020
Douglas S. McGregor, J. Kenneth Shultis
Today the development of ever more energetic particle accelerators is driven by the high energy physics community. With these enormous and costly machines, physicists will perform experiments that will reveal information about the fundamental physics governing the subatomic world. Accelerators with lower energies are also central to other areas of research such as the study of atomic and nuclear physics. A 1-GeV proton accelerator is now used at the Spallation Neutron Source at Oak Ridge National Laboratory to bombard a liquid mercury target. The resulting spallation reactions release copious neutrons which are ideal probes to determine molecular structures. Accelerators can also be used to produce intense x-ray beams that in turn can be used in fundamental research on materials. As in most areas of fundamental research, accelerator technology has spun off many practical applications such as cancer therapy, production of important radionuclides, ion implanting, and food preservation to name a few.
Basics of beam dynamics
Published in Xiaobiao Huang, Beam-based Correction and Optimization for Accelerators, 2019
A particle beam consists of particles that move roughly with the same speed and in the same direction within a finite cross-section. In an accelerator, electromagnetic fields of various distributions in space and time are placed along the path of the beam through the accelerator components to guide the beam motion, change the beam energy, and provide focusing. Beam motion is also affected by the electromagnetic fields generated by the beam itself, directly or through the interactions with the environment. The study of beam motion under the influence of electromagnetic fields in accelerators is called beam dynamics.
Ionizing Radiation
Published in Martin B., S.Z., of Industrial Hygiene, 2018
Accelerators produce radiation by accelerating charged particles in a vacuum through a potential drop of 10,000 to millions of volts or more. Accelerator is a generic term which includes linear accelerators for scientific research, ion implant devices used on the semiconductor electronics production, medical and dental X-ray machines, industrial radiography X-ray machines, cyclotrons to produce artificial radionuclides, cathode ray tubes used as TV screens and computer monitors, and electron microscopes.
Networked control design for an engine throttle valve system
Published in International Journal of Control, 2023
M. Abdelrahim, M. A. Mabrok, M. A. H. Darwish
Automatic control plays an essential role in automotive technology in order to improve the efficiency of vehicle operation, to reduce emissions and to provide some safety features for the passengers, see e.g. Vincentelli and Balluchi (2006) and the references therein. Examples of such control systems include engine and transmission control (Outbib et al., 2014; Sun & Dourra, 2015), cruise control (He et al., 2019; Huang et al., 2018), traction control (Burgio & Zegelaar, 2006), and vehicle suspension (Casavola et al., 2018; Yurlin et al., 2015). One of the most important control tasks is to maintain an appropriate air/fuel ratio to guarantee an efficient combustion inside the engine so that a desirable speed command by the driver can be achieved. To that end, a throttle valve system is used to regulate the amount of air into the intake manifold. The throttle valve system is an electromechanical device that consists of a tilting throttle plate driven by a DC motor via a gear unit. The opening angle of the throttle plate determines the airflow rate and hence the throttle plate angle need to be measured and sent to the controller to ensure the desired operation. For instance, when the driver requires to increase the vehicle forward speed by pressing on the accelerator pedal, the driver's request is sent to the engine control unit (ECU). The ECU consequently translates the driver's demand into a control signal for the throttle valve system to increase the opening of the throttle plate by a certain amount allowing more air flow rate, and vice versa.
An eco-aware framework for AI-based analysis of contextually enriched automotive trip data
Published in Energy Sources, Part A: Recovery, Utilization, and Environmental Effects, 2023
Ivana Gace, Hrvoje Vdovic, Jurica Babic, Vedran Podobnik
Each trip is described by a series of points that carry information about automotive (OBD) data enriched with location, sensor, signal, surrounding traffic, weather and information about data collection time. Automotive data include data on vehicle speed, RPM, accelerator pedal position, engine load, and the like. Sensory data store information about the accelerometer, gyroscope, rotation vector, etc. Signal data contain data about the network, bandwidth, operator name, and other data related to the signal. Surrounding traffic data contain various information, the most important of which is information about the speed limit at the driving location and the current speed of other vehicles on the road. Finally, the weather data contain information about wind speed, cloud cover, visibility and so on. Since each trip is a set of points, within 110 trips we have a total of 65,482 points. In total, drivers and passengers traveled 687 km, with total duration of 24 h, 21 min and 55 s. The average distance of one trip is 6.2 km and the average driving time is 13 min and 17 s.
Framework for fault-tolerant speed tracking control of gasoline engines using the first principle-based engine model
Published in Journal of Control and Decision, 2022
Raheel Anjum, Ahmed Yar, Ghulam Murtaza, Qadeer Ahmed, Aamer I. Bhatti
In a gasoline engine, the throttle position varies to control the airflow rate according to the required torque. Fuel injection is regulated by ECU to achieve desired speed profile by keeping the AFR at a designed value of the engine. Engine speed depends on the torque demand, which is passed by pressing the accelerator pedal to vary the throttle valve angle. Set points of the desired speed provide the interface between accelerator pedal position and engine torque management. Information on desired torque does not exist in reality as position of the accelerator pedal acts as the driver's input for torque generation. In other words, the pedal position signal is interpreted as torque demand, that must be delivered by the vehicle driveline. The pedal map is shown in Figure 6, which gives the relationship between torque demand, throttle opening and engine speed. During nominal driving, accelerator pedal angle is first mapped to the engine throttle opening, which is further mapped to engine speed to generate desired torque. Thus, the speed generation system in an engine can be divided into two subsystems. The first subsystem is comprised of the throttle valve to torque generation in the engine cylinder, whereas the second subsystem is from generation of the torque to engine output speed.