Thermodynamic performance of a double-effect absorption heat-transformer using TFE/E181 as the working fluid

Trifluoroethanol(TFE)-tetraethylenglycol dimethylether (TEGDME or E181) is a new organic working-pair which is non-corrosive, completely miscible and thermally stable up to 250 °C. It is suitable for upgrading low-temperature level industrial waste-heat to a higher temperature level for reuse. In this paper, the thermodynamic performance of the double-effect absorption heat-transformer (DEAHT) using TFE/E181 as the working fluid is simulated, based on the thermodynamic properties of TFE/E181 solution. The results show that, when the temperature in the high-pressure generator exceeds 100 °C and the gross temperature lift is 30 °C, the coefficient of performance (COP) of the DEAHT is about 0.58, which is larger than the 0.48 of the single-stage absorption heat-transformer (SAHT), the increase of COP is about 20%. But it is still less than 0.64 of the DEAHT using LiBr-H2O as the working fluid. Meanwhile, the COP of the DEAHT decreases more rapidly with increases of the absorption temperature than that for the SAHT. The range of available gross temperature-lift for the DEAHT is narrower than that of the SAHT. The higher the temperature in the high-pressure generator, the larger the gross temperature-lift could be. So the double-effect absorption heat-transformer is more suitable for being applied in those circumstances of having a higher-temperature heat-resource and when a higher temperature-lift is not needed.Double-effect absorption heat-transformer Thermodynamic performance Organic working-fluid TFE/E181 Industrial waste-heat recovery

A ratiometric fluorescence probe for imaging sulfur dioxide derivatives in the mitochondria of living cells

Although sulfur dioxide (SO) plays an essential role in several physiological processes, monitoring of intracellular SO at subcellular levels remains challenging due to the lack of rapid and sensitive methods for its quantification in a 100% aqueous solution. Herein, a new hemicyanine dyes-based fluorescence probe, NBD-Id, was designed and synthesized for the detection of SO derivatives in pure aqueous solution and living cells. By virtue of a specific 1,4-addition reaction of SOHSO and the polymethine chain of hemicyanine, significant changes in the absorption and fluorescence emission spectra were observed in less than 20 seconds. The ratiometric fluorescence (F/F) detection of SO derivatives was then obtained with high sensitivity (detection limit 3.6 nM). It was noted that NBD-Id has a specific response towards SO derivatives without interference from other anions and biomolecules. Intracellular fluorescence imaging indicated that NBD-Id is cell membrane permeable and mainly distributed within the mitochondria. Therefore, ratiometric fluorescence imaging of SO derivatives in the mitochondria of MCF-7 cells was successfully demonstrated

CEO power and labor productivity

Purpose: This paper aims to examine how Chief Executive Officer (CEO) power affects firm-level labor productivity. Design/methodology/approach: The authors rely on regression analysis to examine the relation between CEO power and labor productivity. Findings: Following prior research (i.e. the sequential rank order tournament theory), the authors predict that powerful CEOs lead to high labor productivity. They find a significant and positive relationship between CEO power and labor productivity. They further decompose labor productivity into labor efficiency and labor cost components and find a positive (negative) relationship between CEO power and labor efficiency (cost) component, suggesting that more powerful CEOs better manage labor efficiency and control labor cost. The results are also robust to various additional tests. Originality/value: This study contributes to two streams of research: the CEO power literature in finance and the labor productivity and cost literature in accounting. To the best of the authors’ knowledge, it is the first study that performs a direct empirical test on the relation between CEO power and labor productivity

Meaningful Secret Image Sharing Scheme with High Visual Quality Based on Natural Steganography

The (k,n)-threshold Secret Image Sharing scheme (SISS) is a solution to image protection. However, the shadow images generated by traditional SISS are noise-like, easily arousing deep suspicions, so that it is significant to generate meaningful shadow images. One solution is to embed the shadow images into meaningful natural images and visual quality should be considered first. Limited by embedding rate, the existing schemes have made concessions in size and visual quality of shadow images, and few of them take the ability of anti-steganalysis into consideration. In this paper, a meaningful SISS that is based on Natural Steganography (MSISS-NS) is proposed. The secret image is firstly divided into n small-sized shadow images with Chinese Reminder Theorem, which are then embedded into RAW images to simulate the images with higher ISO parameters with NS. In MSISS-NS, the visual quality of shadow images is improved significantly. Additionally, as the payload of cover images with NS is larger than the size of small-sized shadow images, the scheme performs well not only in visual camouflage, but also in other aspects, like lossless recovery, no pixel expansion, and resisting steganalysis

Testing symmetry based on empirical likelihood

<p>In this paper, we propose a general <i>k</i>th correlation coefficient between the density function and distribution function of a continuous variable as a measure of symmetry and asymmetry. We first propose a root-<i>n</i> moment-based estimator of the <i>k</i>th correlation coefficient and present its asymptotic results. Next, we consider statistical inference of the <i>k</i>th correlation coefficient by using the empirical likelihood (EL) method. The EL statistic is shown to be asymptotically a standard chi-squared distribution. Last, we propose a residual-based estimator of the <i>k</i>th correlation coefficient for a parametric regression model to test whether the density function of the true model error is symmetric or not. We present the asymptotic results of the residual-based <i>k</i>th correlation coefficient estimator and also construct its EL-based confidence intervals. Simulation studies are conducted to examine the performance of the proposed estimators, and we also use our proposed estimators to analyze the air quality dataset.</p

A radiomics model fusing clinical features to predict microsatellite status preoperatively in colorectal cancer liver metastasis

Abstract Purpose To study the combined model of radiomic features and clinical features based on enhanced CT images for noninvasive evaluation of microsatellite instability (MSI) status in colorectal liver metastasis (CRLM) before surgery. Methods The study included 104 patients retrospectively and collected CT images of patients. We adjusted the region of interest to increase the number of MSI-H images. Radiomic features were extracted from these CT images. The logistic models of simple clinical features, simple radiomic features, and radiomic features with clinical features were constructed from the original image data and the expanded data, respectively. The six models were evaluated in the validation set. A nomogram was made to conveniently show the probability of the patient having a high MSI (MSI-H). Results The model including radiomic features and clinical features in the expanded data worked best in the validation group. Conclusion A logistic regression prediction model based on enhanced CT images combining clinical features and radiomic features after increasing the number of MSI-H images can effectively identify patients with CRLM with MSI-H and low-frequency microsatellite instability (MSI-L), and provide effective guidance for clinical immunotherapy of CRLM patients with unknown MSI status