Particle shape effect on heat transfer performance in an oscillating heat pipe

The effect of alumina nanoparticles on the heat transfer performance of an oscillating heat pipe (OHP) was investigated experimentally. A binary mixture of ethylene glycol (EG) and deionized water (50/50 by volume) was used as the base fluid for the OHP. Four types of nanoparticles with shapes of platelet, blade, cylinder, and brick were studied, respectively. Experimental results show that the alumina nanoparticles added in the OHP significantly affect the heat transfer performance and it depends on the particle shape and volume fraction. When the OHP was charged with EG and cylinder-like alumina nanoparticles, the OHP can achieve the best heat transfer performance among four types of particles investigated herein. In addition, even though previous research found that these alumina nanofluids were not beneficial in laminar or turbulent flow mode, they can enhance the heat transfer performance of an OHP

Assessment of Cryoprotectant Concentration by Electrical Conductivity Measurement and Its Applications in Cryopreservation

This chapter presents an important application of the electrical conductivity measurement in cryopreservation. Long-term cryopreservation of cells and tissues is essential in both clinical treatments and fundamental researches. In order to reduce the cryo-injury to the cells during cryopreservation, cryoprotective agents (CPAs) should be added before freezing, but also removed after thawing duo to the cytotoxicity. In these steps, severe osmotic stresses may result in injuries to the cells too. Therefore, monitoring the addition and removal of CPAs to the cell samples is critical in order to prevent the osmotic injury. In this chapter, the electrical conductivity measurement was applied to assess the CPA concentration in cryopreservation. Firstly, the standard correlations between the CPA concentration and the electrical conductivity of the solutions (including CPA-NaCl-water ternary solutions and CPA-albumin-NaCl-water quaternary solutions) were experimentally obtained for a few mostly used CPAs. Then a novel ?dilution-filtration? system with hollow fiber dialyzer was designed and applied to remove the CPA from the solutions effectively. Measurement of electrical conductivity was validated as a safer and easier way to on-line and real-time monitoring of CPA concentration in cell suspensions. This work demonstrated a very important application of electrical conductivity in the biomedical engineering field

Virtual Goods Recommendations in Virtual Worlds

Virtual worlds (VWs) are computer-simulated environments which allow users to create their own virtual character as an avatar. With the rapidly growing user volume in VWs, platform providers launch virtual goods in haste and stampede users to increase sales revenue. However, the rapidity of development incurs virtual unrelated items which will be difficult to remarket. It not only wastes virtual global companies’ intelligence resources, but also makes it difficult for users to find suitable virtual goods fit for their virtual home in daily virtual life. In the VWs, users decorate their houses, visit others’ homes, create families, host parties, and so forth. Users establish their social life circles through these activities. This research proposes a novel virtual goods recommendation method based on these social interactions. The contact strength and contact influence result from interactions with social neighbors and influence users’ buying intention. Our research highlights the importance of social interactions in virtual goods recommendation. The experiment’s data were retrieved from an online VW platform, and the results show that the proposed method, considering social interactions and social life circle, has better performance than existing recommendation methods

Effects of Quality of Financial Statements and CEO Turnover

The purpose of this study is to explore the effect of CEO turnover and CFO turnover on earnings management. In addition, Taiwan’s authorities will require listed companies to complete the establishment of audit committee replacing supervisors in 2022. Corporate governance is not an overnight phenomenon. It has been existing from a long time. It is only that the beginning of 21st century when colossal enterprises started to fall, government across globe started giving it due credit. The present paper is an attempt to trace the history of corporate governance. It starts with discussing various theories which led to the development of such an important concept and then dwells on various models in which economies employ corporate governance in their structure and finally the evolution of corporate governance across globe. The paper sheds light on important committees and reforms which have been the genesis of corporate governance across globe. It undertakes an extensive literature review on different aspects of corporate governance. Corporate governance is a concept which still debatable among experts in describing it. The purpose of this study is to explore how the implementation and principal problems of good corporate governance in the management of current limited liability company

Terminal proteins of Streptomyces chromosome can target DNA into eukaryotic nuclei

Streptomyces species are highly abundant soil bacteria that possess linear chromosomes (and linear plasmids). The 5′ ends of these molecules are covalently bound by terminal proteins (TPs), that are important for integrity and replication of the telomeres. There are at least two types of TPs, both of which contain a DNA-binding domain and a classical eukaryotic nuclear localization signal (NLS). Here we show that the NLS motifs on these TPs are highly efficient in targeting the proteins along with covalently bound plasmid DNA into the nuclei of human cells. The TP-mediated nuclear targeting resembles the inter-kingdom gene transfer mediated by Ti plasmids of Agrobacterium tumefaciens, in which a piece of the Ti plasmid DNA is targeted to the plant nuclei by a covalently bound NLS-containing protein. The discovery of the nuclear localization functions of the Streptomyces TPs not only suggests possible inter-kingdom gene exchanges between Streptomyces and eukaryotes in soil but also provides a novel strategy for gene delivery in humans and other eukaryotes

Lipid-related residual risk and renal function for occurrence and prognosis among patients with first-event acute coronary syndrome and normal LDL cholesterol

<p>Abstract</p> <p>Background</p> <p>We investigated relationship of low levels of high density lipoprotein cholesterol (HDL-C), high levels of triglycerides, and renal function for the odds, prognosis and survival following acute coronary events among patients with a first event and normal low density lipoprotein cholesterol levels.</p> <p>Results</p> <p>A case-control study based on 557 patients and 1086 matched control subjects was conducted. Case patients were followed up for survival with a median of 1.9 years. Participants in the higher quintiles of HDL-C had lower odds to develop acute coronary events (the adjusted odds ratios were 0.24 for the second, 0.24 for the third, 0.10 for the fourth and 0.05 for the fifth quintile). Patients with normal glomerular filtration rate were at a lower risk for all-cause death. However, a reverse association between triglycerides and death risk was found: patients with higher triglycerides were at a lower risk for all-cause death (adjusted relative risk, 0.38 for triglycerides ranging from 82 to 132.9 mg/dL, and 0.14 for triglycerides > = 133 mg/dL).</p> <p>Conclusions</p> <p>Low HDL-C was significantly associated with acute coronary events, and triglyceride levels as well as renal function were inversely related to all-cause deaths after the coronary event.</p

The Uses of a Dual-Band Corrugated Circularly Polarized Horn Antenna for 5G Systems

This paper presents the development of a wide-beam width, dual-band, omnidirectional antenna for the mm-wave band used in 5G communication systems for indoor coverage. The 5G indoor environment includes features of wide space and short range. Additionally, it needs to function well under a variety of circumstances in order to carry out its diverse set of network applications. The waveguide antenna has been designed to be small enough to meet the requirements of mm-wave band and utilizes a corrugated horn to produce a wide beam width. Additionally, it is small enough to integrate with 5G communication products and is easy to manufacture. This design is simple enough to have multi-feature antenna performance and is more useful for the femtocell repeater. The corrugated circularly polarized horn antenna has been designed for two frequency bands; namely, 26.5–30 GHz for the low band and 36–40 GHz for high band. The results of this study show that return-loss is better than 18 dB for both low and high band. The peak gain is 6.1 dBi for the low band and 8.7 dBi for the high band. The beam width is 105 degrees and 77 degrees for the low band and the high band, respectively. The axial ratio is less than 5.2 dB for both low and high band. Generally, traditional circularly polarized antennas cannot meet the requirements for broadband. The designs for the antennas proposed here can meet the requirements of FR2 bandwidths. This feature limits axial ratio performance. The measurement error in the current experiment comes from the high precision control on the size of the ridge

Prediction model for high glycated hemoglobin concentration among ethnic Chinese in Taiwan

<p>Abstract</p> <p>Background</p> <p>This study aimed to construct a prediction model to identify subjects with high glycated hemoglobin (HbA1c) levels by incorporating anthropometric, lifestyle, clinical, and biochemical information in a large cross-sectional ethnic Chinese population in Taiwan from a health checkup center.</p> <p>Methods</p> <p>The prediction model was derived from multivariate logistic regression, and we evaluated the performance of the model in identifying the cases with high HbA1c levels (> = 7.0%). In total 17,773 participants (age > = 30 years) were recruited and 323 participants (1.8%) had high HbA1c levels. The study population was divided randomly into two parts, with 80% as the derivation data and 20% as the validation data.</p> <p>Results</p> <p>The point-based clinical model, including age (maximal 8 points), sex (1 point), family history (3 points), body mass index (2 points), waist circumference (4 points), and systolic blood pressure (3 points) reached an area under the receiver operating characteristic curve (AUC) of 0.723 (95% confidence interval, 0.677- 0.769) in the validation data. Adding biochemical measures such as triglycerides and HDL cholesterol improved the prediction power (AUC, 0.770 [0.723 - 0.817], <it>P </it>= < 0.001 compared with the clinical model). A cutoff point of 7 had a sensitivity of 0.76 to 0.96 and a specificity of 0.39 to 0.63 for the prediction model.</p> <p>Conclusions</p> <p>A prediction model was constructed for the prevalent risk of high HbA1c, which could be useful in identifying high risk subjects for diabetes among ethnic Chinese in Taiwan.</p