Critical quality prediction for saturated flow boiling of CO2 in horizontal small diameter tubes

The dryout for flow boiling carbon dioxide (CO₂) in horizontal small diameter tubes is investigated through experiment and theoretical modeling. Tests are conducted in conditions where the saturation temperature is 0, 5, and 10 °C, heat flux is 7.2-48.1 kW/m² and mass flux is 500-3000 kg/m² s. The dryout phenomena of CO₂ are similar with those of water in many respects, while the effects of mass flux on dryout show differences among them. The dryout of CO₂ is predicted by a theoretical dryout model, which is developed and verified with steam-water data. Two entrainment mechanisms of interface deformation and bubble bursting are considered in the model and dryout is determined when the liquid film thickness is less than the critical liquid film thickness, the criteria film thickness of dryout. The present model well predicts the experimental critical qualities except when mass flux is relatively high, at which the deposition of liquid droplet on the liquid film and the occurrence of dryout patches become very significant.     

Developing heat transfer coefficient and pressure drop model for CO2-hydrate gas mixture for CO2 transportation

The issue of CO₂ hydrate has drawn attention in terms of the pipeline transporting and injection process of the captured CO₂. Designing a pipeline network under onshore or offshore conditions for transporting CO₂ and designing a pipeline for injection to a reservoir requires knowing the exact CO₂ thermodynamic status for safety in the pipeline and for controlling operational facilities, including compressors and gas boosters. In the present study, a model for estimating the in-tube heat-transfer coefficient for a CO₂-hydrate gas mixture was developed by considering the significant effects of the temperature difference between the CO₂-hydrate crystallization temperature and the actual operational temperature on the heat transfer coefficient. In addition, a pressure drop model for a CO₂-hydrate gas mixture was developed by introducing a pressure ratio of P/P_crit and the Breault and Mathur model, which was developed for estimating a pressure drop for solid particles and gas flow in a pipeline.

     

Prediction of heat transfer coefficient and compressor power consumption for CO2 with impurities under pipeline transporting condition

Journal of Mechanical Science and Technology - In CCS (carbon capture & storage) process, carbon dioxide is captured with impurities of various componets and different concentration. Under...     

Magnetoluminescence from trion and biexciton in type-II quantum dot

We theoretically investigate optical Aharonov-Bohm (AB) effects on trion and biexciton in the type-II semiconductor quantum dots, in which holes are localized near the center of the dot, and electrons are confined in a ring structure formed around the dot. Many-particle states are calculated numerically by the exact diagonalization method. Two electrons in trion and biexciton are strongly correlated to each other, forming a Wigner molecule. Since the relative motion of electrons are frozen, the Wigner molecule behaves as a composite particle whose mass and charges are twice those of an electron. As a result, the period of AB oscillation for trion and biexciton becomes h/2e as a function of magnetic flux penetrating the ring. We find that the magnetoluminescence spectra from trion and biexciton change discontinuously as the magnetic flux increases by h/2e.PACS: 71.35.Ji, 73.21.-b, 73.21.La, 78.67.Hc.     

Prada Transformer

正在2009年4月下旬,令人期待已久的Prada Transformer在首尔隆重面世,一系列震撼性的跨文化展览、电影放映和现场活动在这里进行。五个月以来,多项跨学科的项目在这个姿态多变的场地上举行了,为韩国带来别树一帜的视觉艺术大融和。Transformer的形态是由一个四面体而衍生的,当每个面旋转至不同的角度时,都能发挥不同的作用。这里举办过的活动包括     

Diagnosis of superficial-type early carcinoma of the gallbladder by endoscopic ultrasonography--comparison with ultrasonography

The detectability of superficial-type carcinoma of the gallbladder by ultrasonography (US) and endoscopic ultrasonography (EUS) were investigated. Eight patients with such carcinoma of the gallbladder were reviewed. They had undergone both US and EUS previous to surgery. The tumor was detected in 3 patients by US, 2 patients with IIa + IIb-type carcinoma and 1 patient with IIa-type carcinoma. Those lesions were visualized as localized thickening of the gallbladder wall or as broad-based tumor. In 2 patients, lesions were not initially detected by US, but were shown by US after the examination by EUS. The tumor was detected by EUS also in 1 case of IIb + IIa-type carcinoma besides those 3 patients mentioned above. All four of these lesions were visualized as broad-based tumor by EUS. It was difficult to detect pure IIb-type or small IIa-type carcinoma even by EUS. In patients with concomitant acute cholecystitis or gallbladder stone, it was difficult to evaluate the abnormal findings of the gallbladder wall.     

Image annotation with incomplete labelling by modelling image specific structured loss

In this paper, we address the problem of image annotation with incomplete labeling, where multiple objects in each training image are not fully labeled. The conventional one‐versus‐all support vector machine (OVA‐SVM), which performs fairly well on full labeling, decays drastically under the setting of incompleteness. Recently, a structured output learning method termed OVA‐SSVM was proposed to boost the performance of OVA‐SVM by modeling the structured associations of labels and show efficiency under the setting of incompleteness. OVA‐SSVM assumes that each training sample includes a single label and adopts an loss measure of classification style where, as long as one of the predicted label is correct, the overall prediction should be considered correct. However, this may not be appropriate for the multilabel annotation task. Therefore, we extend the OVA‐SSVM method to the multilabel situation and design a novel image‐specific structured loss to account for the dependences between predicted labels relying on image label associations. The superiority of the proposed image‐specific structured loss is that it can directly learn the semantic relationships of labels from training data without predefined semantic hierarchy. Extensive empirical results on a variety of benchmark datasets show that the proposed method performs significantly better than OVA‐SSVM on image annotation tasks with incomplete labeling and achieves competitive performance compared to other state‐of‐the‐art methods. © 2015 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.     

Diet-Regulating Microbiota and Host Immune System in Liver Disease

The gut microbiota has been known to modulate the immune responses in chronic liver diseases. Recent evidence suggests that effects of dietary foods on health care and human diseases are related to both the immune reaction and the microbiome. The gut-microbiome and intestinal immune system play a central role in the control of bacterial translocation-induced liver disease. Dysbiosis, small intestinal bacterial overgrowth, translocation, endotoxemia, and the direct effects of metabolites are the main events in the gut-liver axis, and immune responses act on every pathways of chronic liver disease. Microbiome-derived metabolites or bacteria themselves regulate immune cell functions such as recognition or activation of receptors, the control of gene expression by epigenetic change, activation of immune cells, and the integration of cellular metabolism. Here, we reviewed recent reports about the immunologic role of gut microbiotas in liver disease, highlighting the role of diet in chronic liver disease.     

益生菌微胶囊包埋及靶向递送体系研究进展

益生菌因具有调节肠道菌群，预防便秘，增强肠道免疫力等功能，在新型功能性食品、医药和微生态制剂研发生产中具有广阔的应用前景。近年来，益生菌产品的消费以20%的速度在逐年增加。由于益生菌在加工和储藏过程中极易受外界光、温度、氧气等影响而失活，摄食后还需经受住胃酸、胆盐等胃肠环境的挑战，只有少数菌能到达肠道，因此目前很多益生菌产品的活菌数和实际效果都难以达到预期。如何长时间保持益生菌的活性成为制约益生菌产业发展的“卡脖子”技术。近年来，微胶囊包埋及靶向递送体系在材料以及益生菌领域的应用方面取得的重大进展，提高了益生菌及其产品在加工、贮藏过程中的存活率、稳定性和实际功效。本文概述益生菌靶向递送研究现状，总结近年来益生菌微胶囊的壁材、包埋技术的研究进展、存在问题和发展趋势，旨在为进一步研究和开发高活性益生菌产品和技术，提高益生菌产品在体内的功效提供参考。     

Speaker Adaptation Using ICA‐Based Feature Transformation

Speaker adaptation techniques are generally used to reduce speaker differences in speech recognition. In this work, we focus on the features fitted to a linear regression‐based speaker adaptation. These are obtained by feature transformation based on independent component analysis (ICA), and the feature transformation matrices are estimated from the training data and adaptation data. Since the adaptation data is not sufficient to reliably estimate the ICA‐based feature transformation matrix, it is necessary to adjust the ICA‐based feature transformation matrix estimated from a new speaker utterance. To cope with this problem, we propose a smoothing method through a linear interpolation between the speaker‐independent (SI) feature transformation matrix and the speaker‐dependent (SD) feature transformation matrix. From our experiments, we observed that the proposed method is more effective in the mismatched case. In the mismatched case, the adaptation performance is improved because the smoothed feature transformation matrix makes speaker adaptation using noisy speech more robust.