An Investigation into the Thermal Boundary Resistance Associated with the Twin Boundary in Bismuth Telluride

The thermal boundary resistances (TBRs) of twin boundaries occurring at three different atomic layers (Te1, Bi, and Te2) of bismuth telluride (Bi₂Te₃) are investigated in use of the non-equilibrium molecular dynamics (NEMD) simulation method. The simulation results show that among all, the Te1-twin boundaries bring about a lowest interfacial energy corresponding to a most stable system, which explains why this type of twin boundaries is mostly often observed in the laboratory; the Te2-twin boundaries on the other hand possess a largest interfacial energy, resulting in a least stable system. The order in magnitude of the TBRs associated with these three types of twin boundaries is Te2-twin > Bi-twin > Te1-twin. Moreover, the TBR associated with a pair of twin boundaries separated by a distance of 4 unit cell (UC) is found to be about twice as large as that of a single twin boundary of the same type. It implies that the mutual coupling, which causes an increase in TBRs, may be ignored and the effect of twin boundaries may be counted individually as long as the separation distance is larger than 4 UC.     

Myocardial infarction classification with multi-lead ECG using hidden Markov models and Gaussian mixture models

This study presented a new diagnosis system for myocardial infarction classification by converting multi-lead ECG data into a density model for increasing accuracy and flexibility of diseases detection. In contrast to the traditional approaches, a hybrid system with HMMs and GMMs was employed for data classification. A hybrid approach using multi-leads, i.e., lead-V1, V2, V3 and V4 for myocardial infarction were developed and HMMs were used not only to find the ECG segmentations but also to calculate the log-likelihood value which was treated as statistical feature data of each heartbeat's ECG complex. The 4-dimension feature vector extracted by HMMs was clustered by GMMs with different numbers of distribution (disease and normal data). SVMs classifier was also examined for comparison with our system in experimental result. There were total 1129 samples of heartbeats from clinical data, including 582 data with myocardial infarction and 547 normal data. The sensitivity of this diagnosis system achieved 85.71%, specificity achieved 79.82% and accuracy achieved 82.50% statistically.     

A study on the characteristics and pervaporation performance of polyamide thin‐film composite membranes with modified polyacrylonitrile as substrate for bioethanol dehydration

To improve the pervaporation performance in separating an aqueous ethanol solution, polyamide thin‐film composite (TFC) membranes (m‐tolidine‐H‐TMC/mPAN) were prepared through the interfacial polymerization reaction between trimesoyl chloride (TMC) and 2,2'‐dimethylbenzidine hydrochloride (m‐tolidine‐H) on the surface of a modified polyacrylonitrile (mPAN) membrane. The effects of the feed ethanol concentration on the pervaporation performance and the durability of m‐tolidine‐H‐TMC/mPAN TFC membranes were investigated. To choose the optimal mPAN membrane as the TFC substrate, the effect of hydrolysis time on the chemical properties and separation performance of an mPAN substrate was also studied. An appropriate hydrolysis time of 15 min was chosen to obtain the mPAN substrate due to the corresponding high permeation flux. The m‐tolidine‐H‐TMC/mPAN TFC membrane exhibited a high pervaporation performance for ethanol dehydration. A positron annihilation lifetime spectroscopy experiment was used to estimate the mean free‐volume radius of the m‐tolidine‐H‐TMC polyamide selective layer, which lay between the radii of the water and ethanol molecules. © 2013 Society of Chemical Industry     

Roles of Nitric Oxide and Asymmetric Dimethylarginine in Pregnancy and Fetal Programming

Nitric oxide (NO) regulates placental blood flow and actively participates in trophoblast invasion and placental development. Asymmetric dimethylarginine (ADMA) can inhibit NO synthase, which generates NO. ADMA has been associated with uterine artery flow disturbances such as preeclampsia. Substantial experimental evidence has reliably supported the hypothesis that an adverse in utero environment plays a role in postnatal physiological and pathophysiological programming. Growing evidence suggests that the placental nitrergic system is involved in epigenetic fetal programming. In this review, we discuss the roles of NO and ADMA in normal and compromised pregnancies as well as the link between placental insufficiency and epigenetic fetal programming.     

An optimal range of information quantity on computer-based procedure interface design in the advanced main control room

The quantification of information in the interface design is a critical issue. Too much information on an interface can confuse a user while executing a task, and too little information may result in poor user performance. This study focused on the quantification of visible information on computer-based procedures (CBPs). Levels of information quantity and task complexity were considered in this experiment. Simulated CBPs were developed to consist of three levels: high (at least 10 events, i.e. 3.32 bits), medium (4–8 events, i.e. 2–3 bits), and low information quantity (1 or 2 events, i.e. 0 or 1 bits). Task complexity comprised two levels: complex tasks and simple tasks. The dependent variables include operation time, secondary task performance, and mental workload. Results suggested that medium information quantity of five to eight events has a remarkable advantage in supporting operator performance under both simple and complex tasks. This research not only suggested the appropriate range of information quantity on the CBP interface, but also complemented certain deficient results of previous CBP interface design studies. Additionally, based on results obtained by this study, the quantification of information on the CBP interface should be considered to ensure safe operation of nuclear power plants.     

Error-tolerability enhancement via bit inversion and median filtering for single-bit errors in image processing circuits

Microsystem Technologies - Error-tolerance has been proposed as a new method to increase effective yield of a system. The basic idea is that faulty chips might be still acceptable as long as their...     

Multiple roles of color information in the perception of icon‐type images

Despite the ubiquity of icons in computing and mobile devices, the role of color in icon‐based interface design has yet to be fully elucidated. This study began by conducting a card sorting experiment to determine the importance of color in the perception of commercial icons, as opposed to the simpler icons typically used in a laboratory setting. The study also sought to ascertain the importance of color when considered alongside other visual attributes in the general perception of icons. Participants were then asked to answer preset questions as a means of determining the relationship between the known color properties (e.g., hue, saturation, and brightness) of icons and their functional meaning, effectiveness in conveying meaning, and visual attractiveness. Finally, the speed and accuracy was assessed by which participants recognized well‐known icons rendered using familiar and unfamiliar colors. The empirical results identified color as an important attribute in the process of sorting icons, far exceeding other visual attributes including shape, complexity, pictorial style, and orientation. Nonetheless, it appears that color is not necessarily dominant in the initial stages of sorting. The results also revealed that color is closely related to visual attractiveness but largely irrelevant to effectiveness in the conveyance of meaning. The study also confirmed that correct color information is crucial to naming accuracy and the speed at which icons are recognized. Finally, the results indicate that icons lacking a unique symbol as a cue to recognition rely heavily on their signature color for identification. This study opens up several avenues of research by which to enhance our understanding of the functional role of color in icon perception.     

Design and implementation of a web-based medical drawing management system

This paper addresses the architecture and implementation of a medical drawing management system. The system enables physicians to draw directly on a patient picture or built-in anatomical templates of a body part. It contains modules for querying patient data and managing associated drawings including sketching, uploading, and sharing features. The system adapts to embed Windows-based applications into web pages; the web-based applications contain Windows-based graphical tools and enable seamlessly incorporating necessary drawing modules into the web-based healthcare information system at National Taiwan University Hospital. The system provides a web-based sketching capability that effectively support practitioners’ daily operations, as well as the use of paperless, digitizing patient records, and ultimately, will improve the overall quality of healthcare.     

Experimental and computational studies of bulk polymerization of styrene in the presence of N-(O-(1-phenylmethyl)oxy) phthalimide or cyclohexanone-O-(1-phenylmethyl)oxime

Summary Syntheses of potential initiators N-(O-(1-phenylethyl)oxy)phthalimide, N-(O-(1-phenylmethyl)oxy)phthalimide (POP), cyclohexanone-O-(1-phenylethyl)oxime, and cyclohexanone-O-(1-phenylmethyl)oxime (CHPO) are described. Bulk polymerization of styrene in the presence of POP or CHPO and molecular weight measurement by GPC indicate that the polymerization is not a living process. Ab initio calculations show that the C-O or O-N bond cleavage energies of POP and CHPO are close to each other (3: C-O: 46.4, O-N: 47.3 kcal/mol; 1: C-O: 46.9, O-N: 63.0 kcal/mol) and much higher than the similar analogs of 2,2,6,6-tetramethylpiperidinyloxy (TEMPO) (C-O: 20.9, O-N: 34.4 kcal/mol). The similar C-O and O-N bond cleavage energies of the synthesized initiators (POP/CHPO) indicate two possible cleavage pathways and may explain the non-living nature of the polymerization. These results may be helpful in finding future reversible terminator compounds for living polymerization. Received: 28 August 2000/Revised version: 5 December 2000/Accepted: 7 December 2000