Ocean Noise

Scientific and societal concern about the effects of underwater sound on marine ecosystems is growing. While iconic megafauna was of initial concern, more and more taxa are being included. Some countries have joined in multi-national initiatives to measure, monitor and mitigate environmental impacts of ocean noise at large, trans-boundary spatial scales. Approaches to regulating ocean noise change as new scientific evidence becomes available, but may also differ by country. The OCEANOISE conference series has provided a platform for the exchange of scientific results, management approaches, research needs, stakeholder concerns, etc. Attendees have represented various sectors, including academia, offshore industry, defence, NGOs, consultants and government regulators. The published articles in the Special Issue cover a range of topics and applications central to ocean noise

Development and Analysis of a Split-Cycle Engine Fuelled with Methane

Natural gas, which is primarily composed of methane, o ers many advantages over other hydrocarbon fuels for use in reciprocating piston engines. Generally, these include: a high octane rating, wide ammability limits, a high gravimetric energy content, reduced CO2 output, and lower levels of harmful exhaust gas emissions. However, natural gas presents some unique challenges due to its low density and slow laminar burning velocity. The former causes issues with volumetric e ciency and/or charge homogeneity depending on the fuel delivery method. The latter results in prolonged combustion durations that are counter-productive to high fuel conversion e ciencies. A split-cycle engine divides the conventional four-stroke engine process between two adjoining cylinders: one cylinder for intake and compression, the second cylinder for combustion and exhaust. The passage that connects these two cylinders together provides an alternative location for fuel injection and mixing. Furthermore, the uid exchange process occurring from this passage to the combustion chamber is a source of turbulence generation desired to enhance the rate of combustion. In this work a spark ignition split-cycle research engine has been developed and tested for the purpose of evaluating its ability to alleviate the aforementioned problems associated with natural gas (methane) fuelled engines. A novel fuel injector location and timing have been employed and the results show excellent mixture homogeneity was achieved. The fuelling strategy also decoupled the injection event from the engine\u27s intake air ow rate; however, the volumetric e ciency still remained low, between 71{75 %, due to ow losses in the compression cylinder. Combustion rates were found to be very rapid with both early and main burn duration periods on the order of 10{15 °CA (crank angle), despite unfavourable burning conditions (i.e. low cylinder temperature and late combustion phasing). The exhaust gas emission levels of nitrogen oxide, carbon monoxide, and total unburned hydrocarbons were all below average values listed for spark ignition engines

IKUWA6. Shared Heritage

Celebrating the theme ‘Shared heritage’, IKUWA6 (the 6th International Congress for Underwater Archaeology), was the first such major conference to be held in the Asia-Pacific region, and the first IKUWA meeting hosted outside Europe since the organisation’s inception in Germany in the 1990s. A primary objective of holding IKUWA6 in Australia was to give greater voice to practitioners and emerging researchers across the Asia and Pacific regions who are often not well represented in northern hemisphere scientific gatherings of this scale; and, to focus on the areas of overlap in our mutual heritage, techniques and technology. Drawing together peer-reviewed presentations by delegates from across the world who converged in Fremantle in 2016 to participate, this volume covers a stimulating diversity of themes and niche topics of value to maritime archaeology practitioners, researchers, students, historians and museum professionals across the world

Argonne National Laboratory Reports

This revised publication updates a previous report (ANL-7291) initially published in 1965, entitled Radiation Safety Technician Training Course which was intended to complement on-the-job monitoring training for Health Physics Technicians. Sections include basic information concerning atomic structure and other useful physical quantities, natural radioactivity, the properties of alpha, beta, gamma, x rays and neutrons, and the concepts and units of radiation dosimetry (including SI units)

Argonne National Laboratory Reports

Report is an update to 1965 publication regarding on-the-job monitoring training for Health Physics technicians