University of Adelaide

About: University of Adelaide is a education organization based out in Adelaide, South Australia, Australia. It is known for research contribution in the topics: Population & Poison control. The organization has 27251 authors who have published 79167 publications receiving 2671128 citations. The organization is also known as: The University of Adelaide & Adelaide University.

Nanostructured metal-free electrochemical catalysts for highly efficient oxygen reduction.

Abstract: Replacing precious and nondurable Pt catalysts with cheap and commercially available materials to facilitate sluggish cathodic oxygen reduction reaction (ORR) is a key issue in the development of fuel cell technology. The recently developed cost effective and highly stable metal-free catalysts reveal comparable catalytic activity and significantly better fuel tolerance than that of current Pt-based catalysts; therefore, they can serve as feasible Pt alternatives for the next generation of ORR electrocatalysts. Their promising electrocatalytic properties and acceptable costs greatly promote the R&D of fuel cell technology. This review provides an overview of recent advances in state-of-the-art nanostructured metal-free electrocatalysts including nitrogen-doped carbons, graphitic-carbon nitride (g-C3N4)-based hybrids, and 2D graphene-based materials. A special emphasis is placed on the molecular design of these electrocatalysts, origin of their electrochemical reactivity, and ORR pathways. Finally, some perspectives are highlighted on the development of more efficient ORR electrocatalysts featuring high stability, low cost, and enhanced performance, which are the key factors to accelerate the commercialization of fuel cell technology.

Engineering Noise Control: Theory and Practice, Third Edition

Abstract: Fundamentals and Basic Terminology Introduction Noise-Control Strategies Acoustic Field Variables Wave Equations Mean Square Quantities Energy Density Sound Density Sound Power Units Spectra Combining Sound Pressures Impedance Flow Resistance The Human Ear Brief Description of the Ear Mechanical Properties of the Central Partition Noise Induced Hearing Loss Subjective Response to Sound Pressure Level Instrumentation for Noise Measurement and Analysis Microphones Weighting Networks Sound Level Meters Classes of Sound Level Meter Sound Level Meter Calibration Noise Measurements Using Sound Level Meters Time-Varying Sound Noise Level Measurement Data Loggers Personal Sound Exposure Meter Recording of Noise Spectrum Analysers Intensity Meter Energy Density Sensors Sound Source Localization Criteria Introduction Hearing Loss Hearing Damage Risk Hearing Damage Risk Criteria Implementing a Hearing Conservation Program Speech Interference Criteria Psychological Effects of Noise Ambient Noise Level Specification Environmental Noise Level Criteria Environmental Noise Level Surveys Sound Sources and Outdoor Sound Propagation Introduction Simple Source Dipole Source Quadruple Source (Far-Field Approximation) Line Source Piston in an Infinite Baffle Incoherent Plane Radiator Directivity Reflection Effects Reflection and Transmission at a Plane/Two Media Interface Sound Propagation Outdoors, General Concepts Sound Power, its Use and Measurement Introduction Radiation Impedance Relation between Sound Power and Sound Pressure Radiation Field of a Sound Source Determination of Sound Power Using Intensity Measurements Determination of Sound Power Using Surface Vibration Measurements Some Uses of Sound Power Information Sound in Enclosed Spaces Introduction Low Frequencies Bound between Low-Frequency and High-Frequency Behavior High Frequencies, Statistical Analysis Transit Response Porous Sound Absorbers Panel Sound Absorbers Flat and Long Rooms Applications of Sound Absorption Auditorium Design Partitions, Enclosures and Barriers Introduction Sound Transmission through Partitions Noise Reduction vs Transmission Loss Enclosures Barriers Pipe Lagging Muffling Devices Introduction Measures of Performance Diffusers as Muffling Devices Classification of Muffling Devices Acoustic Impedance Lumped Element Devices Reactive Devices Lined Ducts Duct Bends or Elbows Unlined Ducts Effect of Duct End Reflections Duct Break-Out Noise Line Plenum Attenuator Water Injection Directivity of Exhaust Duct Vibration Control Introduction Vibration Isolation Types of Isolators Vibration Absorbers Vibration Neutralizers Vibration Measurement Damping of Vibrating Surfaces Measurement of Damping Sound Power and Sound Pressure Level Estimation Procedures Introduction Fan Noise Air Compressors Compressors for Chillers and Refrigeration Units Cooling Towers Pumps Jets Control Valves Pipe Flow Boilers Turbines Diesel and Gas-Driven Engines Furnace Noise Electric Motors Generators Transformers Gears Transportation Noise Practical Numerical Acoustics Introduction Low-Frequency Region High-Frequency Region: Statistical Energy ANalysis