A new method of multi-beam real-time attitude compensation data processing

The traditional method for processing multi-beam real-time attitude compensation data did not consider the influence of attitude compensation error, which left attitude residual in data. So a new method for processing multi-beam data of real-time attitude compensation was proposed. By studying the nature of attitude compensation error, the calculation method of systematic attitude compensation error was put forward. The concept of correction threshold was introduced and the specific determination method was given. Finally, combining with the principle of real-time attitude compensation, a systematic attitude compensation error correction method, which makes use of a tracking algorithm considering attitude to make secondary attitude correction, was proposed, and the specific processing flow was given. By comparing the data processing accuracy of the tradition method and the new method, the results showed that the new method can effectively reduce the influence of systematic attitude compensation error, and significantly improve the data processing accuracy

Experimental and simulation study of hydrogen sulfide adsorption on impregnated activated carbon under anaerobic conditions

In this study., a sodium carbonate impregnated activated carbon (IAC) was applied as the adsorbent for low concentration hydrogen sulfide (H2S) in nitrogen under the anaerobic conditions in a fixed bed. The effects of impregnation, relative humidity, temperature, and the inlet H2S concentration on the adsorption process were intensively investigated. The data of adsorption capacity were correlated by Langmuir isotherm. The results showed that the data fitted the model well within the concentration range studied. The IAC demonstrated more than three times adsorption capacity for H2S under dry conditions, compared with the original activated carbon (AC). It was confirmed that increasing relative humidity enhanced H2S adsorption capacity on both AC and IAC, and the adsorption capacity of H2S decreased slightly with increasing temperature. To predict breakthrough curves, a one-dimension model for the fixed beds packed with porous adsorbents was proposed and numerically solved. Simulation results matched with the experimental data in most part of the breakthrough curves. (C) 2007 Elsevier B.V. All rights reserved

Phosphate Removal by Ca-Modified Magnetic Sludge Biochar Prepared by a One-Step Hydrothermal Method

The problem of phosphorus pollution and its resource utilization has been a source of general concern. The preparation of green, renewable, and non-secondary pollution adsorbents has become a research direction. In this paper, a one-step hydrothermal preparation method of Ca-modified magnetic sludge biochar (Ca-MSBC) is used for enhancing phosphate removal. The results show that the adsorption rate of phosphate by Ca-MSBC is mainly controlled by chemisorption but is also related to physical adsorption and an internal diffusion mechanism. The maximum phosphorus adsorption capacity of Ca-MSBC was 89.25 mg g−1 at 343 K (initial phosphate concentration 500 mg L−1). After nine cycles of adsorption experiments, the adsorption capacity of 70.16 mg g−1 was still high. In addition, coexisting ions Cl−, NO3−, SO42−, and CO32− have no significant effect on the adsorption properties of phosphate. XRD, FT-IR, VSM, XPS, and N2 adsorption/desorption isotherms showed that the mechanism of phosphate removal from water by Ca-MSBC was mainly the chemical precipitation reaction of phosphate and calcium. The results of this study indicate that Ca-MSBC has potential application and environmental value as a solid waste recycling material for environmental remediation

Search for beta-delayed fission of Ac-228

Radium was radiochemically separated from natural thorium. Thin Ra-228 ->beta Ac-228 sources were prepared and exposed to mica fission track detectors, and measured by an HPGe gamma-ray detector. The beta-delayed fission events of Ac-228 were observed and its beta-delayed fission probability was found to be (5 +/- 2)x10(-12)

Are medical record front page data suitable for risk adjustment in hospital performance measurement? Development and validation of a risk model of in-hospital mortality after acute myocardial infarction

Objectives To develop a model of in-hospital mortality using medical record front page (MRFP) data and assess its validity in case-mix standardisation by comparison with a model developed using the complete medical record data.Design A nationally representative retrospective study.Setting Representative hospitals in China, covering 161 hospitals in modelling cohort and 156 hospitals in validation cohort.Participants Representative patients admitted for acute myocardial infarction. 8370 patients in modelling cohort and 9704 patients in validation cohort.Primary outcome measures In-hospital mortality, which was defined explicitly as death that occurred during hospitalisation, and the hospital-level risk standardised mortality rate (RSMR).Results A total of 14 variables were included in the model predicting in-hospital mortality based on MRFP data, with the area under receiver operating characteristic curve of 0.78 among modelling cohort and 0.79 among validation cohort. The median of absolute difference between the hospital RSMR predicted by hierarchical generalised linear models established based on MRFP data and complete medical record data, which was built as ‘reference model’, was 0.08% (10th and 90th percentiles: −1.8% and 1.6%). In the regression model comparing the RSMR between two models, the slope and intercept of the regression equation is 0.90 and 0.007 in modelling cohort, while 0.85 and 0.010 in validation cohort, which indicated that the evaluation capability from two models were very similar.Conclusions The models based on MRFP data showed good discrimination and calibration capability, as well as similar risk prediction effect in comparison with the model based on complete medical record data, which proved that MRFP data could be suitable for risk adjustment in hospital performance measurement