•Unilateral sample preparation and control of oxygen did not reduce scatter.•Oxide deposition was observed in some facilities while others reported oxide loss.•Interlaboratory statistics indicate ...between-laboratory differences were significant.•Temperature distributions within autoclaves proposed as one cause of scatter.
Supercritical water-cooled reactor candidate materials are typically corrosion-resistant alloys whose mass changes in supercritical water fluctuate around zero. A previous interlaboratory corrosion experiment exercise revealed large scatter in mass change results between laboratories. Here, we reduced systemic differences between laboratories by unilateral preparation of coupons and unilateral chemical cleaning. Type 310S stainless steel and Alloy 800HT test coupons were exposed for 1000 h to 550 °C, 25 MPa, deaerated water. Average mass loss for 310S and 800HT was 38 ± 26 and 51 ± 31 mg/dm2, respectively. Differences in mass transfer, galvanic and local corrosion, and average coupon temperature may explain the poor reproducibility.
Soil microbes are influenced by their environment, and soil pH is well known as a driver of community structure, including within the plant root zone. However, the effect of pH induced changes on ...root-associated microbial communities for plant growth, resource allocation, and disease resistance is not well understood, especially for long-lived woody plants. In this study, we examined whether soil microbial communities altered by soil pH could affect tree growth, resource allocation, and resistance to a soil-borne pathogen. In a controlled greenhouse setting, we treated
Fagus grandifolia
saplings with small amounts of forest soil that had been manipulated to alter soil pH and microbial communities. In addition, 1-yr after inoculation with forest soil, half of the trees were also inoculated with the root rot pathogen
Phytophthora cinnamomi
to induce physiological stress
.
Tree growth showed no response to treatment with forest microbes; however,
P. cinnamomi
altered resource allocation, leading to increased ratios of aboveground to belowground biomass for trees treated with forest microbes. Interestingly, trees grown in pasteurized soil had a tendency toward the opposite pattern of reduced ratios of aboveground to belowground biomass. Soil treatment and pathogen inoculation interacted to alter water transport tissues; stems grown with microbes from acidic forest soil had higher vessel density when challenged with
P. cinnamomi
, while trees grown with microbes from neutral forest soil had higher vessel density in the absence of the pathogen. Our study suggests that the composition of root-associated microbes can affect resource allocation under stressful conditions for long-lived woody plants.
Drain use in pancreatic surgery remains controversial. This survey sought to evaluate habits, experiences, and opinions of experts in the field on the use of drains to provide interesting insights ...for pancreatic surgeons worldwide.
An online survey designed via Google Forms was sent in December 2020 to experienced surgeons of the International Study Group for Pancreatic Surgery.
Forty-two surgeons (42/63, 67%) completed the survey. During their career, 74% (31/42) performed personally >500 pancreatic resections; of these, 9 (21%) >1,500. Sixty-nine percent of the respondents (29/42) declared to always use drains during pancreatic resections and 17% (7/42) in >50% of the operations. For these participants, the use of drains does not increase but reduces the risk of pancreatic fistula and other complications, and more importantly, helps to detect them earlier and manage them better. By contrast, 2 surgeons (5%) declared to never apply drains, whereas other 4 (10%) use drains only in selective cases, deeming that drains increase the risk of infection and other complications. When applied, drains are managed very heterogeneously as for the type of drains, enzyme testing, and removal schedules. Four participants declared to practice continuous irrigation. Twenty-two surgeons (55%) remove drains routinely within the third postoperative day, other 11 (27.5%) only in selected cases, whereas 7 (17.5%) normally keep drains longer.
Despite plenty of publications on this topic, drain management in pancreatic surgery remains very heterogeneous. Safety and the surgeon´s personal experience seem to play a determining role.
For the first time, the response function to high-energy photons of a 3times3 matrix comprising large volume LYSO crystals was measured using energy marked photons provided by the tagged photon ...facility of MAMI. The crystal quality was determined based on the optical transparency, the intrinsic radioactivity and the luminescence yield. Energy and time resolutions for photons up to 490 MeV photon energy have been deduced from the reconstruction of the electromagnetic shower deposited into the crystal array and the data deliver very promising results.
The performance of the most recent prototypes of the ANDA barrel electromagnetic calorimeter (EMC) will be compared. The first large scale prototype PROTO60 was designed to test the performance of ...the improved tapered lead tungstate crystals (PWO-II). The PROTO60 which consists of 6 × 10 crystals was tested at various accelerator facilities over the complete envisaged energy range fulfilling the requirements of the TDR of the ANDA EMC in terms of energy, position and time resolution. To realize the final barrel geometry and to test the final front end electronics, a second prototype PROTO120 has been constructed. It represents a larger section of a barrel slice, containing the most tapered crystals and the close to final components for the ANDA EMC. The performance of both prototypes will be compared with a focus on the analysis procedure including the signal extraction, noise rejection, calibration and the energy resolution. In addition, the influence of the non-uniformity of the crystal on the energy resolution will be discussed.
The National Institute of Standards and Technology (NIST) recently developed a new robotic scanning system for performing near-field measurements at millimeter-wave (mm-wave) frequencies above 100 ...GHz, the configurable robotic millimeterwave antenna (CROMMA) facility. This cost-effective system is designed for high-frequency applications, is capable of scanning in multiple configurations, and is able to track measurement geometry at every point in a scan. The CROMMA combines realtime six-degree-of-freedom optical spatial metrology and robotic motion to achieve antenna positioning to within 25 μm rms. A unified coordinated metrology approach is used to track all positional aspects of scanning. A vector network analyzer is used to capture amplitude and phase. We present spherical near-field measurements of the forward hemisphere of a 24-dBi standard gain horn at 183 GHz. Using the configurable scanning ability, two different scanning radii were used. Near-field data were taken at a 100-mm radius. Direct far-field measurements were also taken at 1000-mm radius. The E- and H-plane patterns are determined from the measurements and compared to theoretical patterns. We describe the system components of the CROMMA and the coordinated metrology approach used. An analysis of the positional repeatability and accuracy achievable is also presented.
Abstract Variation in structural geometry is present in adulthood, but when this variation arises and what influences this variation prior to adulthood remains poorly understood. Ethnicity is ...commonly the focus of research of skeletal integrity and appears to explain some of the variation in quantification of bone tissue. However, why ethnicity explains variation in skeletal integrity is unclear. Methods Here we examine predictors of bone cross sectional area (CSA) and section modulus (Z), measured using dual-energy X-ray absorptiometry (DXA) and the Advanced Hip Analysis (AHA) program at the narrow neck of the femur in adolescent (9–14 years) girls ( n = 479) living in the United States who were classified as Asian, Hispanic, or white if the subject was 75% of a given group based on parental reported ethnicity. Protocols for measuring height and weight follow standardized procedures. Total body lean mass (LM) and total body fat mass (FM) were quantified in kilograms using DXA. Total dietary and total dairy calcium intakes from the previous month were estimated by the use of an electronic semi-quantitative food frequency questionnaire (eFFQ). Physical activity was estimated for the previous year by a validated self-administered modifiable activity questionnaire for adolescents with energy expenditure calculated from the metabolic equivalent (MET) values from the Compendium of Physical Activities. Multiple regression models were developed to predict CSA and Z. Results Age, time from menarche, total body lean mass (LM), total body fat mass (FM), height, total calcium, and total dairy calcium all shared a significant (p < 0.05), positive relationship with CSA. Age, time from menarche, LM, FM, and height shared significant (p < 0.05), positive relationships with Z. For both CSA and Z, LM was the most important covariate. Physical activity was not a significant predictor of geometry at the femoral neck (p ≥ 0.339), even after removing LM as a covariate. After adjusting for covariates, ethnicity was not a significant predictor in regression models for CSA and Z. Conclusion Variability in bone geometry at the narrow neck of the femur is best explained by body size and pubertal maturation. After controlling for these covariates there were no differences in bone geometry between ethnic groups.
•Electrochemical impedance of stainless steel was measured in supercritical water.•High frequency impedance depends on water electric conductivity and permittivity.•Corrosion parameters can be ...obtained from low frequency impedance data.•Local increase in corrosion rate around the critical temperature was confirmed.•Electrochemical data agreed well with weight difference data from literature.
The traditional method of corrosion studies of structural materials exposed to water at high pressures and temperatures is ex-situ weight gain/loss estimation and analyses of the oxide scales. In this work, in-situ electrochemical impedance spectroscopy (EIS) is applied to study behaviour of 316 L stainless steel exposed to sub-critical and super-critical water (SCW) with the aim to investigate the effect of temperature, in particular close to the critical point of water. As the second objective, the effect of exposure time during the long-term exposure at 500 °C was investigated. Impedance data were analyzed and discussed, based on changes in the physical and chemical properties of water. Instantaneous corrosion rate data, estimated from impedance data, were converted in weight differences and compared with the literature data available for 316 L steel corrosion in SCW. The good agreement obtained supports applicability of in-situ EIS for corrosion studies in super-critical range.
Austenitic stainless steel is one of the key structural materials for a wide-range of components for present nuclear power plants. Moreover, this type of steel is also foreseen as a key structural ...material in future reactor systems, the so-called Generation IV. However, for the successful application of these materials in new environmental conditions an integrated Research and Development program needs to be successfully completed. This work is focused to the evaluation of cold-worked AISI-304 stainless steel from 20 to 45% of cold-worked deformation by different spectroscopic techniques within the aim to study the microstructural characteristics. In particular, positron annihilation spectroscopy and small angle neutron scattering have been used for characterization of phase transformation and microstructural behavior. Furthermore, outcomes of corrosion properties of cold-worked AISI-304 stainless steel exposed for 100 and 500
h in super-critical water reactor conditions are correlated with the obtained results.
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