Particle size of aluminum oxide produced by a small rocket motor

Spectrophotometric method for measurement of aluminum oxide particle sizes during burning of solid propellant rocket engin

A comparison of two methods of measuring particle size of Al2O3 produced by a small rocket motor

The size of aluminum oxide particles produced by small rocket motors is determined by tank collection and spectrophotometry. The size of the particulate determines loss in thrust due to particle lag, particulate radiant heat transfer, acoustic attenuation and impingement and rocket plume structure and properties

Recent Measurements at JPL of Particle Size of Aluminum Oxide from Small Rocket Motors

Small rocket engine test firings conducted to measure particle size distribution of aluminum oxide exhaust

DNA fingerprinting analysis of coagulase negative staphylococci implicated in catheter related bloodstream infections

AIMS: The epidemiological assessment of cases of coagulase negative staphylococcal catheter related bloodstream infection. METHODS: Two hundred and thirty patients with suspected catheter related bloodstream infection were evaluated over a two year period. Central venous catheters were cultured both endoluminally and extraluminally. Peripheral blood, catheter hubs, skin entry, and skin control sites were also cultured. Pulsed field gel electrophoresis (PFGE) was used to DNA fingerprint coagulase negative staphylococci isolated from patients with presumptive catheter related bloodstream infection. RESULTS: Sixty cases of catheter related bloodstream infection were identified, 21 of which were attributed to coagulase negative staphylococci. Two hundred and ninety four separate isolates of coagulase negative staphylococci from the 21 cases of catheter related bloodstream infection were subjected to PFGE (mean of 14 for each case). Catheter related bloodstream infection was only confirmed by PFGE analysis in 16 of the 21 cases because in the remaining five cases peripheral blood and central venous catheter coagulase negative staphylococci isolates were different. Skin entry, control skin, and central venous catheter hub isolates matched peripheral blood isolates in six, four, and seven cases, respectively. Coagulase negative staphylococci isolates could not be cultured from the patients’ own skin in seven cases of catheter related bloodstream infection. Central venous catheter lumens were colonised in all cases of catheter related bloodstream infection compared with 44–81% of cases that had positive external surface catheter tip cultures, depending on the threshold used to define significant growth. CONCLUSIONS: Catheter related bloodstream infection as a result of coagulase negative staphylococci may be over stated in about a quarter of cases, unless a discriminatory technique is used to fingerprint isolates. No single, simplistic route of bacterial contamination of central venous catheters was identified, but endoluminal catheter colonisation is invariably present in cases of catheter related bloodstream infection. The use of central venous catheters as a means of access for monitoring and as a route of administration of drugs has become almost mandatory in patients with serious illnesses. Infections of central venous catheters are common and coagulase negative staphylococci remain the most frequent pathogens—for example, 37% of 1267 isolates in one meta-analysis.Controversy remains over the source of, and route of access by, these bacteria to the central venous catheters. Recent developments, such as catheters with antimicrobial properties, are an important advance, but until such issues are resolved it remains unclear how best to reduce the risk of catheter related bloodstream infection. “Pulsed field gel electrophoresis is well recognised as the gold standard for fingerprinting coagulase negative staphylococci” Because there are at least 33 distinct coagulase negative staphylococci species that have been identified, and because methods that use phenotyping alone cannot accurately distinguish between strains of coagulase negative staphylococci, DNA fingerprinting is required to clarify the epidemiology of coagulase negative staphylococci catheter related bacterial bloodstream infection. Despite the accepted difficulties in determining the relatedness of coagulase negative staphylococci, diagnostic laboratories routinely rely on limited information from phenotypic tests to compare isolates fro

The crux of the matter: did the ABC's Catalyst program change statin use in Australia?

This article argues that the ABC’s Catalyst program criticising statins affected people’s willingness to take these drugs. Abstract Objectives: To examine the impact of a two-part special edition of the Australian Broadcasting Corporation\u27s science journalism program Catalyst (titled Heart of the matter), aired in October 2013, that was critical of HMG-CoA reductase inhibitors (“statins”). Design, setting and participants: Population-based interrupted time-series analysis of a 10% sample of Australian long-term concessional beneficiaries who were dispensed statins under the Pharmaceutical Benefits Scheme (about 51% of all people who were dispensed a statin between 1 July 2009 and 30 June 2014); dispensing of proton pump inhibitors (PPIs) was used as a comparator. Main outcome measures: Change in weekly dispensings and discontinuation of use of statins and PPIs, adjusting for seasonal and long-term trends, overall and (for statins only) stratified by the use of cardiovascular and diabetes medicines. Results: In our sample, 191 833 people were dispensed an average of 26 946 statins weekly. Following the Catalyst program, there was a 2.60% (95% CI, 1.40%–3.77%; P < 0.001) reduction in statin dispensing, equivalent to 14 005 fewer dispensings Australia-wide every week. Dispensing decreased by 6.03% (95% CI, 3.73%–8.28%; P < 0.001) for people not dispensed other cardiovascular and diabetes medicines and 1.94% (0.42%–3.45%; P = 0.01) for those dispensed diabetes medicines. In the week the Catalyst program aired, there was a 28.8% (95% CI, 15.4%–43.7%; P < 0.001) increase in discontinuation of statin use, which decayed by 9% per week. An estimated 28 784 additional Australians ceased statin treatment. Discontinuation occurred regardless of the use of other cardiovascular and diabetes medicines. There were no significant changes in PPI use after the Catalyst program. Conclusions: Following airing of the Catalyst program, there was a temporary increase in discontinuation and a sustained decrease in overall statin dispensing. Up until 30 June 2014, there were 504 180 fewer dispensings of statins, and we estimate this to have affected 60 897 people

ARE ECONOMIC FUNDAMENTALS DRIVING FARMLAND VALUES?

Farmland, Land Value, Agricultural Finance, Land Economics/Use, Q14, Q15,