A map and a pipe : a new approach to characterizing erosion-corrosion regimes of Fe in three dimensions using CFD modelling

In studies of erosion-corrosion, much work has been carried out in recent years to identify regimes of behaviour. Such regimes describe the transition between the erosion and corrosion dominated mechanisms. They can also be used, by assigning various criteria, to identify other regimes of behaviour such as extent of "synergy/antagonism" in the process, so-called "additive" behaviour and the extent of wastage. Despite this work, there has been very little effort to combine the two dimensional erosion-corrosion map with CFD modelling approaches, in which the characteristics of the fluid are accounted for in the regime description. This means that extrapolation of such maps in two dimensions to a three dimensional real surface presents some difficulties. However, it is these surfaces that corrosion engineers are required to tailor, either through modification of the material composition, the surface or the process parameters, for optimum erosion-corrosion resistance. In this paper, a methodology is generated to combine the concepts of CFD modelling, and the erosion-corrosion regime map for a specific geometry and for a range of pure metals in descending order in the Galvanic series. The changes in regimes are presented as a function of variation in the erosion and corrosion variables i.e. particle size, hardness and solution pH. Erosion-corrosion regimes are presented, based on the model results, showing the wide range of mechanistic and wastage mechanisms possible over the component surface

Review of \u3cem\u3eStriving to Save: Creating Policies for Financial Security of Low-Income Families.\u3c/em\u3e Margaret Sherrard Sherraden & Amanda Moor McBride, with Sondra G. Beverly. Reviewed by Carol B. Stack.

Book review of Margaret Sherrard Sherraden & Amanda Moor McBride, with Sondra G. Beverly, Striving to Save: Creating Policies for Financial Security of Low-Income Families. University of Michigan Press (2010). 340 pages, $65.00 (hardcover)

Predicted and hot-film measured Tollmien-Schlichting wave characteristics

The Tollmien-Schlichting (TS) instability is a time-dependence instability which can lead to transition of laminar boundary layers on airfoils. A comparison of theoretical predictions and experimental observations of the TS instability on the NLF(1)-0414F airfoil designed by Viken and Pfenninger. The theoretical predictions were obtained using the SALLY stability code. Test results, from the same hot films that were used to detect transition, revealed that TS waves could be detected by the hot films if the hot-film signal was adequately modified

Micro-abrasion resistance of thermochemically treated steels in aqueous solutions: Mechanisms, maps, materials selection

The area of micro-abrasion is an interesting and relatively recent area in tribo-testing methodologies, where small particles of less than 10 μm are employed between interacting surfaces. It is topical for a number of reasons; its direct relation to the mechanisms of the wear process in bio-tribological applications, ease in conducting tests and the good repeatability of the test results. It has widespread applications in conditions used in the space and offshore industries to bio-engineering for artificial joints and implants. There have been many recent studies on the micro-abrasion performance of materials, ranging from work basic metals to nano-structured coatings. However, no significant work is reported on the micro-abrasion resistance of thermochemically treated steels. Hence, this paper looks at the performance of two thermochemically treated steels, Tenifer bath nitride stainless steel (T-SS) and vanadized carbon steel (V-CS) in such conditions with reference to the stainless steel (SS) by varying the applied load and sliding distance. The results indicated that T-SS demonstrates exceptionally poor resistance to micro-abrasion. It was observed that the heat treatment process and properties of the hardened layer (hardness and thickness) are extremely important in determining the micro-abrasion resistance of such steels. Finally, the results were used to develop micro-abrasion mechanism and wastage maps, which can be used to optimize the surface treated materials for micro-abrasion resistance

Immunological investigations and immunotherapy in lung cancer

This thesis examines the value of immunological methods in the treatment, diagnosis and assessment of prognosis of lung cancer.Delayed hypersensitivity skin tests and laboratory tests of immunological function were performed in patients with operable lung cancer who were then randomly allocated to the autograft or non-autograft groups. In a pilot trial in 15 patients, the autograft group received intradermal injections of autologous irradiated tumour cells and BCG. during three weeks after operation. In this trial only, both groups of patients were given radiotherapy to the mediastinum three weeks after operation. In the subsequent main trial in 83 patients, both groups received one pre¬ operative percutaneous injection of BCG.. The autograft group only were given serial injections of autologous irradiated tumour cells and percutaneous BCG. during the three weeks after operation.While the prevalence of positive tuberculin tests among the lung cancer patients before operation was similar to that of controls, sensitisation after challenge by DNCB. was less common in the lung cancer patients, suggesting that there is some impairment of the afferent limb of the immunological response in this condition. Lymphocyte transformation by PPD. but not PHA. or pokeweed mitogen was depressed. Relative depression of certain immunological tests was seen in patients with more advanced disease and a poorer prognosis (total lymphocytes, DNCB.reactivity) and in squamous cell carcinoma (tuberculin test). The main immunological effect of postoperative immunotherapy was a prolonged increase in tuberculin reactivity.By constructing actuarial life table curves for survival and duration of freedom from tumour recurrence and by measuring the median times for these, it was shown that DNCB. positive autograft group patients and those with stage I tumours had better clinical results than non-autograft patients (p = 0.02 to p = 0.09)« Although a higher proportion of stage I patients in the autograft group survived free of tumour recurrence two years after operation, the difference was not statistically significant. Adjuvant specific autologous immunotherapy thus seemed, at best, to have only a weak therapeutic action in operable lung cancer.In a separate study, circulating levels of tumour markers in unselected lung cancer patients were compared with those of control patients with benign pulmonary disease. Elevated levels of carcinoembryonic antigen (CEA.) were found in 17%» of pregnancy-associated a^-glycoprotein (a^-PAG.) in 16%, of casein in 1 b°/o, of human chorionic gonadotrophin in 6°/o and of a-foetoprotein in 1.5%• CEA. levels were higher in patients with extensive disease (23%) • There was discordance between raised levels of CEA. and a^-PAG.. Elevated levels of one or more markers were found in kG'/o of patients in whom four or more markers were measured. In a different series of unselected lung cancer patients, circulating levels of immunoreactive ACTH. were raised in 2k°/o of patients with small cell carcinoma but only in 3°/° of patients with non-small cell carcinoma. Elevated levels were commoner in small cell carcinoma patients with extensive disease.The results showed that when the upper limit of "normal" was that of patients with benign pulmonary disease, the prevalence of elevated levels of tumour markers was much lower than that claimed by other authors. Hence measurement of these markers is of little or no diagnostic value in lung cancer

Advanced passive communication satellite systems comparison studies. Volume 1 - Summary Final report

Passive communication satellites feasibility for Comsat system - Vol.

Advanced passive communication satellite systems comparison studies. Volume 2 - Technical discussion Final report

Passive communication satellites feasibility for Comsat system - Vol.

A feasibility study of signed consent for the collection of patient identifiable information for a national paediatric clinical audit database

Objectives: To investigate the feasibility of obtaining signed consent for submission of patient identifiable data to a national clinical audit database and to identify factors influencing the consent process and its success. Design: Feasibility study. Setting: Seven paediatric intensive care units in England. Participants: Parents/guardians of patients, or patients aged 12-16 years old, approached consecutively over three months for signed consent for submission of patient identifiable data to the national clinical audit database the Paediatric Intensive Care Audit Network (PICANet). Main outcome measures: The numbers and proportions of admissions for which signed consent was given, refused, or not obtained (form not returned or form partially completed but not signed), by age, sex, level of deprivation, ethnicity (South Asian or not), paediatric index of mortality score, length of hospital stay (days in paediatric intensive care). Results: One unit did not start and one did not fully implement the protocol, so analysis excluded these two units. Consent was obtained for 182 of 422 admissions (43%) (range by unit 9% to 84%). Most (101/182; 55%) consents were taken by staff nurses. One refusal (0.2%) was received. Consent rates were significantly better for children who were more severely ill on admission and for hospital stays of six days or more, and significantly poorer for children aged 10-14 years. Long hospital stays and children aged 10-14 years remained significant in a stepwise regression model of the factors that were significant in the univariate model. Conclusion: Systematically obtaining individual signed consent for sharing patient identifiable information with an externally located clinical audit database is difficult. Obtaining such consent is unlikely to be successful unless additional resources are specifically allocated to training, staff time, and administrative support

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.