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In the April 2017 edition of this journal, the Author published a theoretical Technical Note in the peer-reviewed section of the journal. Commentary on that Technical Note was provided in Forum section of that same issue by Jeff Parnell of the NSW Department of Planning and Environment. The primary concerns were that simplification of the method could result in underestimation of noise impacts. This reply aims to allay some of those concerns.

Measurement procedures for calculating sound power levels of mining equipment often include modifications to the formal requirements of ISO6395 for practicality and safety purposes on site. The formal procedures involving six measurement points are necessary for homologation certification against contractual requirements for the supply of mining equipment. This is a relatively minor percentage of the total number of sound power tests conducted within the Australian coalfields, however, as most testing is for ongoing compliance purposes where consent conditions require sound power testing of mining fleets every 2 or 3 years. Acoustical consultants have reported accurate results by using a reduced 4-point measurement regime which enables consent conditions to be met without undue disturbance to a mine’s operations. A theoretical basis for omission of two of the ISO measurement points is presented, as well as demonstration that a 2-point measurement regime is mathematically equivalent to the 4-point method. A correction for using sound pressure instead of sound intensity for calculation of sound power level is also calculated.

Alcohol misuse is common and increasing in the United Kingdom, and has a significant effect on patients with orthopaedic conditions both in the acute and elective setting. Identifying patients with alcohol-related disorders, and understanding the consequences are essential for their management. This article reviews the literature with regards to both diseases caused directly by alcohol and those associated with its consumption, and considers their impact on orthopaedic practice.

Shoulder arthroplasty is an established successful treatment with increasing numbers of primary procedures being performed each year. There is also an increasing revision surgery burden linked to this and for a number of reasons. A comprehensive and logical approach, to the assessment of a patient for consideration of revision shoulder surgery, is provided. The evidence base for indications for revision surgery and expected outcomes has been comprehensively reviewed to aid surgical decision-making by the surgeon and patient.

Variations in the anatomy of the abdominal aorta and its branches are of interest as vessel geometry not only determines flow dynamics, but is also crucial in the pathogenesis of vascular disease. The relationship between the anterior visceral and renal arteries is important when undertaking diagnostic arteriography and endovascular interventions. To examine these relationships, the length of the abdominal aorta was determined and measurements taken of the position of origin of the celiac artery, superior mesenteric artery (SMA), inferior mesenteric artery (IMA) and renal arteries, as well as the three-dimensional projection of each vessel from the aorta. The mean level of bifurcation of the aorta was at the lower third of the body of L4, with the celiac artery, SMA, renal arteries and IMA arising at the level of the T12/L1 intervertebral disc, upper third of the body of L1, lower third of the body of L1 and lower third of the body of L3, respectively. The horizontal projection of the celiac artery, SMA and IMA was to the left of the midline; in the sagittal plane, the celiac artery and SMA projected anteriorly and the IMA posteriorly; in the coronal plane all vessels projected inferiorly, with the SMA to the right and the IMA to the left. The celiac artery, SMA and both renal arteries all arise from the proximal half of the abdominal aorta within 45 mm of each other, with the origins of the renal arteries being remarkably consistent. It is concluded that the celiac artery and SMA are both useful landmarks for determining the position of the renal arteries.

A number of variations in hepatic arterial anatomy have been described. Anomalous arterial supply is of particular relevance to the hepatobiliary, pancreatic or liver transplant surgeon.We describe the case of a 57-year-old gentleman who presented with painless obstructive jaundice and was found to have a mass in the head of the pancreas. At pylorus-preserving pancreaticoduodenectomy a distal quadrifurcation of the hepatic artery was discovered. It gave rise to the right hepatic artery, left hepatic artery, intermediate branch and a right accessory hepatic artery. The right accessory hepatic artery gave rise to the gastroduodenal artery.The surgeon and interventional radiologist need to be aware of the potential for such aberrant anatomy in order to avoid potentially disastrous complications.

Acute posterior shoulder dislocations are severe and possibly easily missed injuries. High clinical suspicion, a properly performed physical evaluation, and the appropriate shoulder imaging are necessary in order to diagnose and manage these injuries timely and efficiently. Treatment may be closed reduction and immobilization with the arm slightly abducted and externally rotated for 4–6 weeks. The size of the humeral head defect (reverse Hill–Sachs lesion) should determine if some kind of tendon transfer or humeral head reconstruction by the use of an articular allograft is indicated. When the humeral head defect exceeds 45% of the articular surface, prosthetic replacement is considered.

Abstract A mid-infrared spectroscopic measurement technique is presented for determination of the concentration of methane and other short-chained aliphatic hydrocarbons dissolved in sea water. This approach will be used for studying gas hydrate reservoirs providing analytical information on the amount of methane, ethane, and propane in the vicinity of hydrate fields. On account of their methane content gas hydrates are considered a potential energy resource for the future. Furthermore, environmental concerns are related to methane as greenhouse gas. If large amounts of methane are released from hydrate sites through the water column into the atmosphere major impact on the climate is expected. Furthermore, gas hydrates are stabilizing the sea floor and disturbances e.g. by oil exploration drillings can result in release of large amounts of gas posing serious risks for oil rigs. The proposed target analytes are detected at low concentrations due to their molecule specific absorption spectra in the mid-infrared spectral range (3-20 µm). As the water matrix itself is a strong IR absorber, conventional transmission spectroscopy can not be applied. The presented approach is based on attenuated total reflection (ATR) spectroscopy utilizing a polymer coated waveguide as sensor head. This measurement principle is based on IR radiation evanescently guided as exponentially decaying electromagnetic field at the waveguide-polymer interface. Hence, resonant absorptions of IR-active molecules present at the waveguide-polymer interface result in spectra similar to conventional transmission absorption experiments. Hydrophobic polymer coatings at the waveguide surface prevent water from being in contact with the evanescent field and simultaneously enrich analytes at the waveguide-polymer interface for sensitivity enhancement. The deep sea sensor will be based on a compact Fourier transform infrared (FT-IR) spectrometer and a high-pressure sensor head for ATR spectroscopy encapsulated into a spherical glass pressure vessel. Concentrations of multiple analytes dissolved in sea water with overlapping spectral features are evaluated using chemometric1 data evaluation algorithms, which are modified to handle spectroscopic difficulties encountered in deep sea applications. Introduction Gas hydrates ([ 1 ] - [ 5 ] and further citations given there) are of growing interest mainly due to three reasons:Since gas hydrates are a major source of methane and natural gas, they are considered as an important future energy resource. The economic impact of gas hydrates has been discussed recently [ 6 ]. It was estimated that there is more than twice as much carbon bound in gas hydrates than in crude oil, natural gas, and coal deposits together [ 5 ], [ 7 ].Sub sea gas hydrate fields are very sensitive to environmental conditions, in particular temperature and pressure. If these condition change, gaseous methane is released in large quantities into the atmosphere [ 8]. Methane, however, acts as green house gas with a warming effect 30 times stronger than CO2. Moreover, methane is slowly oxidized to CO2 and resides in the atmosphere as green house gas for a long time.