86 research outputs found
Chemical Looping Combustion of Rice Husk
A thermodynamic investigation of direct chemical looping combustion (CLC) of rice husk is presented in this paper. Both steam and CO2 are used for gasification within the temperature range of 500–1200˚C and different amounts of oxygen carriers. Chemical equilibrium model was considered for the CLC fuel reactor. The trends in product compositions of the fuel reactor, were determined. Rice husk gasification using 3 moles H2O and 0 moles CO2 per mole carbon (in rice husk) at 1 bar pressure and 900˚C was found to be the best operating point for hundred percent carbon conversion in the fuel reactor. Such detailed thermodynamic studies can be useful to design chemical looping combustion processes using different fuels
A multisite study of a breast density deep learning model for full-field digital mammography and synthetic mammography
PURPOSE: To develop a Breast Imaging Reporting and Data System (BI-RADS) breast density deep learning (DL) model in a multisite setting for synthetic two-dimensional mammographic (SM) images derived from digital breast tomosynthesis examinations by using full-field digital mammographic (FFDM) images and limited SM data.
MATERIALS AND METHODS: A DL model was trained to predict BI-RADS breast density by using FFDM images acquired from 2008 to 2017 (site 1: 57 492 patients, 187 627 examinations, 750 752 images) for this retrospective study. The FFDM model was evaluated by using SM datasets from two institutions (site 1: 3842 patients, 3866 examinations, 14 472 images, acquired from 2016 to 2017; site 2: 7557 patients, 16 283 examinations, 63 973 images, 2015 to 2019). Each of the three datasets were then split into training, validation, and test. Adaptation methods were investigated to improve performance on the SM datasets, and the effect of dataset size on each adaptation method was considered. Statistical significance was assessed by using CIs, which were estimated by bootstrapping.
RESULTS: Without adaptation, the model demonstrated substantial agreement with the original reporting radiologists for all three datasets (site 1 FFDM: linearly weighted Cohen κ [κ
CONCLUSION: A BI-RADS breast density DL model demonstrated strong performance on FFDM and SM images from two institutions without training on SM images and improved by using few SM images
Insulin resistance:Genetic associations with depression and cognition in population based cohorts
We are grateful to the families who took part in GS:SFHS, general practitioners and the Scottish School of Primary Care for their help in recruitment, and the whole GS:SFHS team that includes academic researchers, clinic staff, laboratory technicians, clerical workers, IT staff, statisticians and research managers. The research reported here, and the genotyping of GS:SFHS samples was funded by the Wellcome Trust, (Wellcome Trust Strategic Award ‘STratifying Resilience and Depression Longitudinally’ (STRADL) Reference 104036/Z/14/Z) and by the Medical Research Council. SF acknowledges support from the National Institute of Mental Health, USA (R01MH113619; R01MH116147) and the consortium for Psychopathology and Allostatic load across the Life Span (PALS; https://www.pals-network.org) AMM acknowledges the financial support received from the Dr. Mortimer and Theresa Sackler Foundation. IJD and AMM are members of The University of Edinburgh Centre for Cognitive Ageing and Cognitive Epidemiology, part of the cross council Lifelong Health and Wellbeing Initiative (MR/K026992/1). Generation Scotland received core support from the Chief Scientist Office of the Scottish Government Health Directorates (CZD/16/6) and the Scottish Funding Council (HR03006). Funding from the Biotechnology and Biological Sciences Research Council and Medical Research Council is gratefully acknowledged.Peer reviewedPublisher PD
Prognostic model to predict postoperative acute kidney injury in patients undergoing major gastrointestinal surgery based on a national prospective observational cohort study.
Background: Acute illness, existing co-morbidities and surgical stress response can all contribute to postoperative acute kidney injury (AKI) in patients undergoing major gastrointestinal surgery. The aim of this study was prospectively to develop a pragmatic prognostic model to stratify patients according to risk of developing AKI after major gastrointestinal surgery. Methods: This prospective multicentre cohort study included consecutive adults undergoing elective or emergency gastrointestinal resection, liver resection or stoma reversal in 2-week blocks over a continuous 3-month period. The primary outcome was the rate of AKI within 7 days of surgery. Bootstrap stability was used to select clinically plausible risk factors into the model. Internal model validation was carried out by bootstrap validation. Results: A total of 4544 patients were included across 173 centres in the UK and Ireland. The overall rate of AKI was 14·2 per cent (646 of 4544) and the 30-day mortality rate was 1·8 per cent (84 of 4544). Stage 1 AKI was significantly associated with 30-day mortality (unadjusted odds ratio 7·61, 95 per cent c.i. 4·49 to 12·90; P < 0·001), with increasing odds of death with each AKI stage. Six variables were selected for inclusion in the prognostic model: age, sex, ASA grade, preoperative estimated glomerular filtration rate, planned open surgery and preoperative use of either an angiotensin-converting enzyme inhibitor or an angiotensin receptor blocker. Internal validation demonstrated good model discrimination (c-statistic 0·65). Discussion: Following major gastrointestinal surgery, AKI occurred in one in seven patients. This preoperative prognostic model identified patients at high risk of postoperative AKI. Validation in an independent data set is required to ensure generalizability
Composition and morphology study of acid-digested pond ash
The present study examines the chemical composition and morphology of raw and acid-digested pond ash samples that were collected from four ash ponds of the Fertilizer Corporation of India Limited, Sindri unit, Jharkhand, India. Scanning electron microscopy and energy dispersive X-ray spectroscopy were used to analyse the four pond ash samples. The aim of the study was to characterize the pond ash samples in order to assess their utilization based on morphological characteristics. Besides, loss-on-ignition and leaching studies (both with distilled water and under acidic medium conditions) were also conducted to understand the mobility of various elements in the leachates. The information provided herein would be useful to clearly understand the difference in the chemical composition and morphology of the raw and acid digested pond ash samples
Influence of Thermal Maturity and Maceral Content of Coal Seams on In-situ Gas and its Composition at East Bokaro CBM Block, Jharkhand, India
The East Bokaro CBM block is one of the most promising area for bituminous rank coal bed methane production in India. This work investigates the coal seams of Barakar and Karharbari Formations for measuring their in-situ gas content, maceral composition, thermal maturity (Ro%), gas composition and its controlling parameters. The depth of coal core samples laterally varies from 394.0 to 1091.05m and thickness of coal seams varies from 0.45 to 20.9m. The coal samples are vitrinite rich, thermally matured and potential source rock of methane gas. Large amount of desorbed gas (1.57 to 10.50cc/g) contributing to in-situ gas content (2.2 to 11.8cc/g), signify control of overburden pressure to retain gas in coal seams. The desorbed gas was analysed for molecular as well as isotopic composition and correlated with the petrographic constituents and vitrinite reflectance of the coal beds. The large quantity of methane concentration compared to C2 and C3 and ratio of C1/(C2+C3), indicates thermogenic origin of coal seam gas during bituminisation and de-bituminisation stages. The increase in percentage of C1 with Ro% implies that methane concentration increases proportionately with coal rank. Enriched ä13C1isotopic values and presence of C2 and higher hydrocarbons indicates the possibility of mixing of methane, generated at high temperatures, with C2+ hydrocarbons during transport and storage. The paper presents various relations suggesting in-situ gas content and its composition controlled by thermal maturity and maceral group of coa
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