Transport, magnetic, thermodynamic and optical properties in Ti-doped Sr_2RuO_4

We report on electrical resistivity, magnetic susceptibility and magnetization, on heat capacity and optical experiments in single crystals of Sr_2Ru_(1-x)Ti_xO_4. Samples with x=0.1 and 0.2 reveal purely semiconducting resistivity behavior along c and the charge transport is close to localization within the ab-plane. A strong anisotropy in the magnetic susceptibility appears at temperatures below 100 K. Moreover magnetic ordering in c-direction with a moment of order 0.01 mu_B/f.u. occurs at low temperatures. On doping the low-temperature linear term of the heat capacity becomes reduced significantly and probably is dominated by spin fluctuations. Finally, the optical conductivity reveals the anisotropic character of the dc resistance, with the in-plane conductance roughly following a Drude-type behavior and an insulating response along c

GT2006-91080 FLAME-OUT DETECTION FOR GAS TURBINE ENGINES BASED UPON THERMOCOUPLE SIGNAL ANALYSIS

ABSTRACT This paper describes an experimental study to examine the potential of using Exhaust Gas Temperature (EGT) thermocouples for prompt flame-out detection in gas turbine engines. The approach taken involved accelerating the response of a shielded, slow response thermocouple using electronic processing of the signal. Thus, the abrupt drop in temperature characteristic of a flame-out could be detected within a much shorter time period than would be possible through a conventional thermocouple temperature measurement method. This was intended to provide a robust alternative to existing optical flame-out sensors which have fast response but can be susceptible to false flame-out indications due to window sooting. A production EGT thermocouple with online electronic processing was compared with a production optical flame sensor from a GE F-404 and a laboratory photodiode sensing system. The devices were tested in a full scale GE J-85 combustion chamber sector rig with optical access. The results showed that the thermocouple flame sensor had a response time to flame-outs of less than 100 ms. This was much faster than a conventional thermocouple, but still an order of magnitude longer than the optical flame sensor. However, whereas the optical flame sensor could yield ambiguous results about the presence of flame under some conditions, the thermocouple flame sensor provided a clear indication of flame-out events for all the conditions that were tested

Advances in Catchment Science, Hydrochemistry, and Aquatic Ecology Enabled by High-Frequency Water Quality Measurements

High-frequency water quality measurements in streams and rivers have expanded in scope and sophistication during the last two decades. Existing technology allows in situ automated measurements of water quality constituents, including both solutes and particulates, at unprecedented frequencies from seconds to subdaily sampling intervals. This detailed chemical information can be combined with measurements of hydrological and biogeochemical processes, bringing new insights into the sources, transport pathways, and transformation processes of solutes and particulates in complex catchments and along the aquatic continuum. Here, we summarize established and emerging high-frequency water quality technologies, outline key high-frequency hydrochemical data sets, and review scientific advances in key focus areas enabled by the rapid development of high-frequency water quality measurements in streams and rivers. Finally, we discuss future directions and challenges for using high-frequency water quality measurements to bridge scientific and management gaps by promoting a holistic understanding of freshwater systems and catchment status, health, and function

Global Intraurban Intake Fractions for Primary Air Pollutants from Vehicles and Other Distributed Sources

We model intraurban intake fraction (iF) values for distributed ground-level emissions in all 3646 global cities with more than 100,000 inhabitants, encompassing a total population of 2.0 billion. For conserved primary pollutants, population-weighted median, mean, and interquartile range iF values are 26, 39, and 14-52 ppm, respectively, where 1 ppm signifies 1 g inhaled/t emitted. The global mean urban iF reported here is roughly twice as large as previous estimates for cities in the United States and Europe. Intake fractions vary among cities owing to differences in population size, population density, and meteorology. Sorting by size, population-weighted mean iF values are 65, 35, and 15 ppm, respectively, for cities with populations larger than 3, 0.6-3, and 0.1-0.6 million. The 20 worldwide megacities (each >10 million people) have a population-weighted mean iF of 83 ppm. Mean intraurban iF values are greatest in Asia and lowest in land-rich high-income regions. Country-average iF values vary by a factor of 3 among the 10 nations with the largest urban populations

Risk factors, complications and survival after upper abdominal surgery:a prospective cohort study

Background: Preoperative weight loss and abnormal serum-albumin have traditionally been associated with reduced survival. More recently, a correlation between postoperative complications and reduced long-term survival has been reported and the significance of the relative proportion of skeletal muscle, visceral and subcutaneous adipose tissue has been examined with conflicting results. We investigated how preoperative body composition and major non-fatal complications related to overall survival and compared this to established predictors in a large cohort undergoing upper abdominal surgery. Methods: From 2001 to 2006, 447 patients were included in a Norwegian multicenter randomized controlled trial in major upper abdominal surgery. Patients were now, six years later, analyzed as a single prospective cohort and overall survival was retrieved from the National Population Registry. Body composition indices were calculated from CT images taken within three months preoperatively. Results: Preoperative serum-albumin 5 % (HR = 1.38, p = 0.023) were independently associated with reduced survival. There was no association between any of the preoperative body composition indices and reduced survival. Major postoperative complications were independently associated with reduced survival but only as long as patients who died within 90 days were included in the analysis. Conclusions: Our study has confirmed the robust significance of the traditional indicators, preoperative serum-albumin and weight loss. The body composition indices did not prove beneficial as global indicators of poor prognosis in upper abdominal surgery. We found no association between non-fatal postoperative complications and long-term survival

Postoperative outcomes in oesophagectomy with trainee involvement

BACKGROUND: The complexity of oesophageal surgery and the significant risk of morbidity necessitates that oesophagectomy is predominantly performed by a consultant surgeon, or a senior trainee under their supervision. The aim of this study was to determine the impact of trainee involvement in oesophagectomy on postoperative outcomes in an international multicentre setting. METHODS: Data from the multicentre Oesophago-Gastric Anastomosis Study Group (OGAA) cohort study were analysed, which comprised prospectively collected data from patients undergoing oesophagectomy for oesophageal cancer between April 2018 and December 2018. Procedures were grouped by the level of trainee involvement, and univariable and multivariable analyses were performed to compare patient outcomes across groups. RESULTS: Of 2232 oesophagectomies from 137 centres in 41 countries, trainees were involved in 29.1 per cent of them (n = 650), performing only the abdominal phase in 230, only the chest and/or neck phases in 130, and all phases in 315 procedures. For procedures with a chest anastomosis, those with trainee involvement had similar 90-day mortality, complication and reoperation rates to consultant-performed oesophagectomies (P = 0.451, P = 0.318, and P = 0.382, respectively), while anastomotic leak rates were significantly lower in the trainee groups (P = 0.030). Procedures with a neck anastomosis had equivalent complication, anastomotic leak, and reoperation rates (P = 0.150, P = 0.430, and P = 0.632, respectively) in trainee-involved versus consultant-performed oesophagectomies, with significantly lower 90-day mortality in the trainee groups (P = 0.005). CONCLUSION: Trainee involvement was not found to be associated with significantly inferior postoperative outcomes for selected patients undergoing oesophagectomy. The results support continued supervised trainee involvement in oesophageal cancer surgery

Association analysis of low-phosphorus tolerance in West African pearl millet using DArT markers

Pearl millet [Pennisetum glaucum (L.) R. Br.] is a food security crop in the harshest agricultural regions of the world. While low soil phosphorus (P) availability is a big constraint on its production, especially in West Africa (WA), information on genomic regions responsible for low-P tolerance in pearl millet is generally lacking. We present the first report on genetic polymorphisms underlying several plant P-related parameters, flowering time (FLO) and grain yield (GY) under P-limiting conditions based on 285 diversity array technology markers and 151 West African pearl millet inbred lines phenotyped in six environments in WA under both high-P and low-P conditions. Nine markers were significantly associated with P-related traits, nine markers were associated with FLO, whereas 13 markers were associated with GY each explaining between 5.5 and 15.9 % of the observed variation. Both constitutive and adaptive associations were observed for FLO and GY, with markers PgPb11603 and PgPb12954 being associated with the most stable effects on FLO and GY, respectively, across locations. There were a few shared polymorphisms between traits, especially P-efficiency-related traits and GY, implying possible colocation of genomic regions responsible for these traits. Our findings help bridge the gap between quantitative and molecular methods of studying complex traits like low-P tolerance in WA. However, validation of these markers is necessary to determine their potential applicability in marker-assisted selection programs targeting low-P environments, which are especially important in WA where resource-poor farmers are expected to be the hardest hit by the approaching global P crisis