The Effects of Hydrogen on Alloy Steel Production

As a result of work done in the last twenty years or so, it is now accepted that hydrogen can cause unsoundness in ingots in killed steel , with accompanying defects in the products of such ingots . It is reasonably established that hydrogen, if present in solid steel, Call lead to reduction in the ductility. It is also fairly certain that hydrogen plays a very important part in the formation of hairline cracks. Reduction in ductility and hairline cracks are both extremely unwelcome to the producer of large forgings and he has to go to considerable lengths to avoid these ill-effects of hydrogen. To him, therefore, and to any producer of high quality steel, a clearer under-standing of the effects of hydrogen in steel, together with an indication of the means which may be useful in preventing excessive amounts of hydrogen from entering the steel , is of great value

Chemical variations in Yellowknife Bay formation sedimentary rocks analyzed by ChemCam on board the Curiosity rover on Mars

The Yellowknife Bay formation represents a ~5 m thick stratigraphic section of lithified fluvial and lacustrine sediments analyzed by the Curiosity rover in Gale crater, Mars. Previous works have mainly focused on the mudstones that were drilled by the rover at two locations. The present study focuses on the sedimentary rocks stratigraphically above the mudstones by studying their chemical variations in parallel with rock textures. Results show that differences in composition correlate with textures and both manifest subtle but significant variations through the stratigraphic column. Though the chemistry of the sediments does not vary much in the lower part of the stratigraphy, the variations in alkali elements indicate variations in the source material and/or physical sorting, as shown by the identification of alkali feldspars. The sandstones contain similar relative proportions of hydrogen to the mudstones below, suggesting the presence of hydrous minerals that may have contributed to their cementation. Slight variations in magnesium correlate with changes in textures suggesting that diagenesis through cementation and dissolution modified the initial rock composition and texture simultaneously. The upper part of the stratigraphy (~1 m thick) displays rocks with different compositions suggesting a strong change in the depositional system. The presence of float rocks with similar compositions found along the rover traverse suggests that some of these outcrops extend further away in the nearby hummocky plains.

Effects of vertical distribution of soil inorganic nitrogen on root growth and subsequent nitrogen uptake by field vegetable crops

Information is needed about root growth and N uptake of crops under different soil conditions to increase nitrogen use efficiency in horticultural production. The purpose of this study was to investigate if differences in vertical distribution of soil nitrogen (Ninorg) affected root growth and N uptake of a variety of horticultural crops. Two field experiments were performed each over 2 years with shallow or deep placement of soil Ninorg obtained by management of cover crops. Vegetable crops of leek, potato, Chinese cabbage, beetroot, summer squash and white cabbage reached root depths of 0.5, 0.7, 1.3, 1.9, 1.9 and more than 2.4 m, respectively, at harvest, and showed rates of root depth penetration from 0.2 to 1.5 mm day)1 C)1. Shallow placement of soil Ninorg resulted in greater N uptake in the shallow-rooted leek and potato. Deep placement of soil Ninorg resulted in greater rates of root depth penetration in the deep-rooted Chinese cabbage, summer squash and white cabbage, which increased their depth by 0.2–0.4 m. The root frequency was decreased in shallow soil layers (white cabbage) and increased in deep soil layers (Chinese cabbage, summer squash and white cabbage). The influence of vertical distribution of soil Ninorg on root distribution and capacity for depletion of soil Ninorg was much less than the effect of inherent differences between species. Thus, knowledge about differences in root growth between species should be used when designing crop rotations with high N use efficiency

Is omission of free text records a possible source of data loss and bias in Clinical Practice Research Datalink studies? A case-control study.

This is the final version of the article. Available from the publisher via the DOI in this record.OBJECTIVES: To estimate data loss and bias in studies of Clinical Practice Research Datalink (CPRD) data that restrict analyses to Read codes, omitting anything recorded as text. DESIGN: Matched case-control study. SETTING: Patients contributing data to the CPRD. PARTICIPANTS: 4915 bladder and 3635 pancreatic, cancer cases diagnosed between 1 January 2000 and 31 December 2009, matched on age, sex and general practitioner practice to up to 5 controls (bladder: n=21 718; pancreas: n=16 459). The analysis period was the year before cancer diagnosis. PRIMARY AND SECONDARY OUTCOME MEASURES: Frequency of haematuria, jaundice and abdominal pain, grouped by recording style: Read code or text-only (ie, hidden text). The association between recording style and case-control status (χ(2) test). For each feature, the odds ratio (OR; conditional logistic regression) and positive predictive value (PPV; Bayes' theorem) for cancer, before and after addition of hidden text records. RESULTS: Of the 20 958 total records of the features, 7951 (38%) were recorded in hidden text. Hidden text recording was more strongly associated with controls than with cases for haematuria (140/336=42% vs 556/3147=18%) in bladder cancer (χ(2) test, p<0.001), and for jaundice (21/31=67% vs 463/1565=30%, p<0.0001) and abdominal pain (323/1126=29% vs 397/1789=22%, p<0.001) in pancreatic cancer. Adding hidden text records corrected PPVs of haematuria for bladder cancer from 4.0% (95% CI 3.5% to 4.6%) to 2.9% (2.6% to 3.2%), and of jaundice for pancreatic cancer from 12.8% (7.3% to 21.6%) to 6.3% (4.5% to 8.7%). Adding hidden text records did not alter the PPV of abdominal pain for bladder (codes: 0.14%, 0.13% to 0.16% vs codes plus hidden text: 0.14%, 0.13% to 0.15%) or pancreatic (0.23%, 0.21% to 0.25% vs 0.21%, 0.20% to 0.22%) cancer. CONCLUSIONS: Omission of text records from CPRD studies introduces bias that inflates outcome measures for recognised alarm symptoms. This potentially reinforces clinicians' views of the known importance of these symptoms, marginalising the significance of 'low-risk but not no-risk' symptoms.SJP is funded by a University of Exeter PhD studentship. This report presents independent research part funded by the National Institute for Health Research Programme Grants for Applied Research programme (RP-PG-0608- 10045). The views expressed are those of the authors and not necessarily those of the National Health Service, the National Institute for Health Research, or the Department of Health

Airway events in obese vs. non-obese elective surgical patients: a cross-sectional observational study

Obesity is an increasingly prevalent comorbidity within the UK population. The aim of this study was to determine the proportion of obese patients in an elective surgical population. The second aim was to determine the choice of airway equipment and incidence of airway events in obese vs. non-obese patients. We conducted a cross-sectional observational study over two 24-h periods in March 2018 across 39 hospitals in the greater London area. Data were collected regarding 1874 patients. The incidence of obesity was 32% in the study population compared with 26% in the general UK population (p < 0.0001). Minor airway events were defined as: desaturation to Sp O2 < 90%; failed mask ventilation; supraglottic airway device problem; aspiration; airway trauma and difficult intubation; or recognised oesophageal intubation. Major airway events were defined as: unrecognised oesophageal intubation; a 'cannot intubate cannot oxygenate' emergency; the need for unplanned front-of-neck airway; cardiac arrest; or unplanned intensive care unit admission due to an airway event. In total, 89 minor and two major airway events were recorded. Obese patients were more likely to experience a minor airway event (RR 2.39, 95%CI 1.60-3.57), the most common being desaturation (Sp O2 < 90%). The use of a supraglottic airway device in obese vs. non-obese patients was associated with increased airway events (RR 3.46 [1.88-6.40]). Tracheal intubation vs. supraglottic airway device use increased with obesity class but was not associated with a decrease in airway events (RR 0.90 [0.53-1.55]). Our data suggest that obesity is more common in the elective surgical vs. general population and minor airway events are more common in obese vs. non-obese elective patients

Modelling diverse root density dynamics and deep nitrogen uptake — a simple approach

We present a 2-D model for simulation of root density and plant nitrogen (N) uptake for crops grown in agricultural systems, based on a modification of the root density equation originally proposed by Gerwitz and Page in J Appl Ecol 11:773–781, (1974). A root system form parameter was introduced to describe the distribution of root length vertically and horizontally in the soil profile. The form parameter can vary from 0 where root density is evenly distributed through the soil profile, to 8 where practically all roots are found near the surface. The root model has other components describing root features, such as specific root length and plant N uptake kinetics. The same approach is used to distribute root length horizontally, allowing simulation of root growth and plant N uptake in row crops. The rooting depth penetration rate and depth distribution of root density were found to be the most important parameters controlling crop N uptake from deeper soil layers. The validity of the root distribution model was tested with field data for white cabbage, red beet, and leek. The model was able to simulate very different root distributions, but it was not able to simulate increasing root density with depth as seen in the experimental results for white cabbage. The model was able to simulate N depletion in different soil layers in two field studies. One included vegetable crops with very different rooting depths and the other compared effects of spring wheat and winter wheat. In both experiments variation in spring soil N availability and depth distribution was varied by the use of cover crops. This shows the model sensitivity to the form parameter value and the ability of the model to reproduce N depletion in soil layers. This work shows that the relatively simple root model developed, driven by degree days and simulated crop growth, can be used to simulate crop soil N uptake and depletion appropriately in low N input crop production systems, with a requirement of few measured parameters

Magnetic transfer function entropy and the 2009 Mw = 6.3 L'Aquila earthquake (Central Italy)

Abstract. With the aim of obtaining a deeper knowledge of the physical phenomena associated with the 2009 L'Aquila (Central Italy) seismic sequence, culminating with a Mw = 6.3 earthquake on 6 April 2009, and possibly of identifying some kind of earthquake-related magnetic or geoelectric anomaly, we analyse the geomagnetic field components measured at the magnetic observatory of L'Aquila and their variations in time. In particular, trends of magnetic transfer functions in the years 2006–2010 are inspected. They are calculated from the horizontal to vertical magnetic component ratio in the frequency domain, and are very sensitive to deep and lateral geoelectric characteristics of the measurement site. Entropy analysis, carried out from the transfer functions with the so called transfer function entropy, points out clear temporal burst regimes of a few distinct harmonics preceding the main shock of the seismic sequence. A possible explanation is that they could be related to deep fluid migrations and/or to variations in the micro-/meso-fracturing that affected significantly the conductivity (ordered/disordered) distribution in a large lithospheric volume under the seismogenic layer below L'Aquila area. This interpretation is also supported by the analysis of hypocentres depths before the main shock occurrence

Root growth and nitrate uptake of three different catch crops in deep soil layers

Catch crops can reduce NO3 losses from leaching, but little is known about the importance of deep rooting for the efficiency of NO3 depletion. In a field experiment, we investigated the N uptake and root growth of three types of catch crops using minirhizotrons (glass tubes of 70-mm o.d.) reaching 2.4 m. Our purpose was to evaluate minirhizotron methodology and the importance of deep rooting in the ability of catch crops to take up NO3 from deep soil layers. Nitrogen uptake was studied over a 6-d period at the end of October by injection of 15NO3 at four depths in the ranges: 0.4 to 1, 0.5 to 1.4, and 1 to 2.5 m under Italian ryegrass (Lolium multiflorum Lam.), winter rye (Secale cereale L.), and fodder radish (Raphanus sativus L. var. oleiformis Pers.), respectively. The root depth of the three species were 0.6, 1.1, and more than 2.4 m, respectively. No 15N was taken up from placements below root depth, and linear relationships were found between root density and 15N uptake from different depths. Residual soil NO3 of 18, 59, and 87 kg N ha−1 was left under fodder radish, winter rye, and ryegrass, respectively. The measurements obtained with the minirhizotron method were highly relevant for evaluating N uptake from different soil layers, and root depths of the catch crops were important for N depletion. Knowledge about root growth and N uptake in deep soil layers may be utilized when designing crop rotations with improved N use efficiency. Where N has been left by a preceding crop and leached to deeper soil layers, it may be recycled by deep-rooted catch crops

Characterising those with incident polymyalgia rheumatica in primary care: results from the PMR Cohort Study.

BACKGROUND: The aim was to characterise the sociodemographic, general health and polymyalgia rheumatica (PMR)-specific features of participants in a large inception cohort of patients with PMR diagnosed in UK primary care. METHODS: Patients (n = 739) with a new diagnosis of PMR were referred into the study and mailed a questionnaire detailing their general health and sociodemographic characteristics in addition to the symptoms of and treatment for PMR. Characteristics of responders and non-responders were compared and descriptive statistics were used to characterise the health of the cohort. RESULTS: A total of 654 individuals responded to the questionnaire (adjusted response 90.1 %). Responders and non-responders were similar in age, gender and deprivation (based on postcode). The mean (standard deviation) age of the recruited cohort was 72.4 (9.3) years; 62.2 % were female. The sample reported high levels of pain and stiffness (8 out of 10 on numerical rating scales) and reported stiffness that lasted throughout the day. High levels of functional impairment, fatigue, insomnia and polypharmacy were also reported. Overall, women reported worse general and PMR-specific health than did men. CONCLUSIONS: This first primary care cohort of patients with incident PMR is similar in demographic terms to cohorts recruited in secondary care. However, the extent of symptoms, particularly reported stiffness, is higher than has been described previously. Given the majority of patients with PMR are exclusively managed in primary care, this cohort provides important information on the course of PMR in the community that will help clinicians managing this painful and disabling condition

Magnetic transfer function entropy and the 2009 Mw = 6.3 L’Aquila earthquake (Central Italy)

With the aim of obtaining a deeper knowledge of the physical phenomena associated with the 2009 L’Aquila (Central Italy) seismic sequence, culminating with a Mw = 6.3 earthquake on 6 April 2009, and possibly of identifying some kind of earthquake-related magnetic or geoelectric anomaly, we analyse the geomagnetic field components measured at the magnetic observatory of L’Aquila and their variations in time. In particular, trends of magnetic transfer functions in the years 2006–2010 are inspected. They are calculated from the horizontal to vertical magnetic component ratio in the frequency domain, and are very sensitive to deep and lateral geoelectric characteristics of the measurement site. Entropy analysis, carried out from the transfer functions with the so called transfer function entropy, points out clear temporal burst regimes of a few distinct harmonics preceding the main shock of the seismic sequence. A possible explanation is that they could be related to deep fluid migrations and/or to variations in the micro-/meso-fracturing that affected significantly the conductivity (ordered/disordered) distribution in a large lithospheric volume under the seismogenic layer below L’Aquila area. This interpretation is also supported by the analysis of hypocentres depths before the main shock occurrence