Short Commentaries for Imaging of Gas-liquid Annular Flows for Underbalanced Drilling Using Electrical Resistance Tomography

The paper may be of particular interest to the readers as it presented a unsteady flow phenomenon of annular flow recognition which would occur during underbalanced drilling. This paper presents a feasibility study on calculation of gas volume fraction and visualisation of flow regimes in gas-liquid upwards annular flow using ERT. Experiments were conducted at three flow regimes, namely bubble, transition pseudo-static and slug. Gas volume fraction profiles were reconstructed with the modified sensitivity coefficient back projection method (MSBP) with a sensitivity map generated from an annular finite element mesh respectively. 

Flow regimes were visualised by axial images stacked from diameter-pixels of 2D tomograms reconstructed with the conjugate gradient method (SCG). Although tomographic images cannot be as clear as the photographs captured during theme asurements, ERT is still able to provide enough information regarding the prevailing flow regime within the annulus. The air volume fraction profiles in the annulus region, produced from the ERT, indicate a good agreement between the profiles and visual observation (photographs). The stacked images are reasonably accurate representation of air water in the annulus region for the conditions used in this study.

Keys to Selecting a Prediction Model for Carcass Composition from Computed Tomography Images

Linear, nonlinear and volume measurements obtained from computed tomography (CT) images of live pigs are good predictors of carcass characteristics there are different ways to analyse the goodness of a prediction equation, including the decomposition of the predicted error and the biases and coefficient of determination. 

The present paper compares the goodness of fit of individual prediction equations within three different geno types and the prediction obtained by a global equation for the different geno types at the same time comparison is performed by means of the error decomposition, the standard deviation of the bias and the coefficient of model determination The results showed a good mean square prediction error and a high error due to disturbances (random effects) for most of the predictions

Deblurring computed tomography medical images by using Gaussian prior

Due to the blurring artefact of various real-world limitations computed tomography (CT) images get affected. Such pervasive scarcities are usually difficult toavoid and they vastly contributed in concealing the important medicalinformation that existed already. As a result, the visual quality of the recorded images is reduced immensely. 

Hence, different deblurring concepts have been practised to address the ill-posed problem. Intensive tests have been conducted to demonstrate the validity of this algorithm, for which bothnaturally and synthetically degraded CT images are developed. Furthermore, the results obtained from the conducted experiments revealed that the effectiveness of the adopted algorithm has overtaken various famous algorithms in terms of recorded accuracy, speed and visual quality.

Short Commentaries for Imaging of Gas-liquid Annular Flows for Underbalanced Drilling Using Electrical Resistance Tomography

The paper may be of particular interest to the readers as it presented an unsteady flow phenomenon of annular flow recognition which would occur during underbalanced drilling. This paperpresents a feasibility study on calculation of gas volume fraction andvisualisation of flow regimes in gas-liquid upwards annular flow using ERT. Experiments were conducted at three flow regimes, namely bubble, transition pseudo-static and slug. 

Gas volume fraction profiles were reconstructed with the modified sensitivity coefficient back projection method (MSBP) with a sensitivity map generated from an annular finite element mesh respectively. Flow regimes were visualised by axial images stacked from diameter-pixels of 2Dtomograms reconstructed with the conjugate gradient method (SCG). Although tomographic images cannot be as clear as the photographs captured during the measurements, ERT is still able to provide enough information regarding the prevailing flow regime within the annulus. The air volume fraction profiles in the annulus region, produced from the ERT, indicate a good agreement between the profiles and visual observation (photographs). The stacked images are reasonably accurate representation of air water in the annulus region for the conditions used in this study.