Allocating harmonic emission to MV customers in long feeder systems

Previous work has attempted to find satisfactory methods for the allocation of harmonic current emission MV subsystems containing long feeders. It has been proposed that best use of the network\u27s harmonic absorption capacity is made if the allocated current varies with the inverse square root of the harmonic impedance at the point of connection. It has been shown that an exact solution following this principle requires an impracticably large amount of data. Here it is assumed that each feeder supplied from a given substation has its load distributed uniformly and continuously along it, giving equations requiring only a modest amount of data. It is demonstrated by means of a suitable example that the method is sufficiently accurate for practical situations where loads are lumped non-uniformly

Tracking the full annual-cycle of the Great Knot, Calidris tenuirostris, a long-distance migratory shorebird of the East Asian-Australasian Flyway

The Great Knot Calidris tenuirostris is one of the iconic long-distance migratory species of the East Asian-Australasian Flyway. However, despite extensive flagging and banding efforts, very little is known about the migratory strategies and the breeding grounds of this species that spends the non-breeding season mainly on the northern shorelines of Australia. Using light-level geolocators deployed on Great Knots at Roebuck Bay (Western Australia), we describe the individual migration strategies, breeding locations and breeding-related behaviour. Based on data from eight successfully tracked individuals, we found that all except one migrated to the western part of the known breeding range. This was 2,000–2,500 km from the eighth individual that commenced breeding in the potentially sep- arated eastern part of the range. Light intensity and temperature profiles provided evidence that four of the birds successfully hatched chicks. Of the three which failed, one appeared to have laid a second clutch before failing again. Arrival at the breeding grounds and the laying of eggs were remarkably synchronous between individuals, as were the arrival dates back at Roebuck Bay. Departure from the breeding grounds was more spread out, partly dependent on breeding success and also as a result of females probably leaving the nesting area before males. The individual migration strategies confirmed the strong dependence of this species on the Yellow Sea as their major stopover site during both southward and northward migration. Furthermore, all individuals stopped at least once on their northward journey to the Yellow Sea from Australia. And in reverse, all individuals stopped at least once on the southward migration before arriving at the Yellow Sea coming from their Arctic breeding grounds. The results indicate that this species will most likely be further affected by the rapid habitat loss in the area of the Yellow Sea and other parts of the Chinese coastline

Perceptions of Australasian emergency department staff of the impact of alcohol-related presentations

Objectives: To survey emergency department (ED) clinical staff about their perceptions of alcohol-related presentations. Design, setting and participants: A mixed methods online survey of ED clinicians in Australia and New Zealand, conducted from 30 May to 7 July 2014. Main outcome measures: The frequency of aggression from alcoholaffected patients or their carers experienced by ED staff; the perceived impact of alcohol-related presentations on ED function, waiting times, other patients and staff. Results: In total, 2002 ED clinical staff completed the survey, including 904 ED nurses (45.2%) and 1016 ED doctors (50.7%). Alcohol-related verbal aggression from patients had been experienced in the past 12 months by 97.9% of respondents, and physical aggression by 92.2%. ED nurses were the group most likely to have felt unsafe because of the behaviour of these patients (92% reported such feelings). Alcohol-related presentations were perceived to negatively or very negatively affect waiting times (noted by 85.5% of respondents), other patients in the waiting room (94.4%), and the care of other patients (88.3%). Alcohol-affected patients were perceived to have a negative or very negative impact on staff workload (94.2%), wellbeing (74.1%) and job satisfaction (80.9%). Conclusions: Verbal and physical aggression by alcohol-affected patients is commonly experienced by ED clinical staff. This has a negative impact on the care of other patients, as well as on staff wellbeing. Managers of health services must ensure a safe environment for staff and patients. More importantly, a comprehensive public health approach to changing the prevailing culture that tolerates alcohol-induced unacceptable behaviour is required

Severe acute respiratory syndrome coronavirus 2 and blood safety : an updated review

Background: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a novel human coronavirus first identified in late 2019 and subsequently declared a worldwide pandemic in March 2020. In this review, we provide an overview of the implications of SARS-CoV-2 for blood safety and sufficiency. Summary: Approximately one-third of SARS-CoV-2 infections are asymptomatic. The reported mean incubation period typically varies from 2 to 11 days, but longer periods up to 22 days have been reported. The blood phase of SARS-CoV-2 appears to be brief and low level, with RNAaemia detectable in only a small proportion of patients, typically associated with more severe disease and not demonstrated to be infectious virus. A small number of presymptomatic and asymptomatic blood phase cases have been reported. Transfusion-transmission (TT) of SARS-CoV-2 has not been reported. Therefore, the TT risk associated with SARS-CoV-2 is currently theoretical. To mitigate any potential TT risk, but more importantly to prevent respiratory transmission in donor centers, blood services can implement donor deferral policies based on travel, disease status, or potential risk of exposure and encourage staff vaccination. Key Messages: The TT risk of SARS-CoV-2 appears to be low. The biggest risk to blood services in the current COVID-19 pandemic is to maintain the sufficiency of the blood supply while minimizing respiratory transmission of SARS-CoV-2 to donors and staff while donating blood

Staphylococcus aureus Bacteremia, Australia

S. aureus bacteremia in Australia is increasingly caused by MRSA, which is likely to affect empiric prescribing of antimicrobial drugs in suspected cases

Staphylococcus aureus bacteremia, Australia

Staphylococcus aureus bacteremia (SAB) is common and increasing worldwide. A retrospective review wyas undertaken to quantify the number of cases, their place of acquisition, and the proportions caused by methicillin-resistant S. aureus (MRSA) in 17 hospitals in Australia. Of 3,192 episodes, 1,571 (49%) were community onset. MRSA caused 40% of hospital-onset episodes and 12% of community-onset episodes. The median rate of SAB was 1.48/1,000 admissions (range 0.61-3.24; median rate for hospital-onset SAB was 0.7/1,000 and for community onset 0.8/1,000 admissions). Using these rates, we estimate that ≈6,900 episodes of SAB occur annually in Australia (35/100,000 population). SAB is common, and a substantial proportion of cases may be preventable. The epidemiology is evolving, with >10% of community-onset SAB now caused by MRSA. This is an emerging infectious disease concern and is likely to impact on empiric antimicrobial drug prescribing in suspected cases of SAB

The effect of data aggregation interval on voltage results

For various technical and operational reasons, many power quality surveys are carried out using non-standard data aggregation intervals. The data aggregation interval is the time interval that rapidly sampled data is reduced to by the monitoring instrument for subsequent analysis and reporting. Some of the rationales for using non-standard data aggregation intervals include instrumentation limitations, memory restrictions, a belief that more insights may be obtained from data captured at faster aggregation intervals and dual use of instrumentation (such is the case for many smart revenue meters). There is much conjecture over the effect which the data aggregation interval will have on the final outcomes of a power quality survey. IEC61000-4-30 which is the international standard describing power quality monitoring methodology suggests 10 minute data aggregation intervals are appropriate for routine power quality monitoring of most power quality disturbances including magnitude of supply voltage. This paper investigates the variation observed for magnitude of supply voltage monitoring when data is captured at a range of data aggregation intervals

Harmonic allocation using IEC/TR 61000-3-6 at the distribution/transmission interface

IEC Technical Report 61000-3-6 gives principles to be applied to ensure acceptable harmonic levels in power systems. Detailed analysis methods have been developed to apply these principles to both distribution and transmission systems. At the transmission/distribution interface, it is found that transmission harmonic allocations can be as little as one third of the allocation which would be given to an equivalent distribution load. Possible adverse consequences are discussed and several modifications to avoid this mismatch are given. The recommended modification is a hybrid approach combining aspects of both the distribution and transmission allocation methods