Internal short circuit in Li-ion cells

Effects of internal short circuit (ISCr) on thermal stability of Li-ion cells of various sizes (130-1100 mAh) are investigated using a combination of experimental methods and thermal modeling. Three experimental methods were evaluated: small nail penetration, small indentation, and cell pinch test. The small nail penetration and indentation tests created significant heat sinking to the cell-can or to the nail. Only the cell pinch test provided a reasonable approximation of a high risk ISCr event. ISCr location plays a critical role in the consequences of an ISCr event. ISCr at the edge of the electrode is the worst case because of its limited heat conduction to the cell-can. The effects of cell capacity and state of charge on ISCr are also evaluated through tests and thermal modeling.     

Applications of the psychotherapy phase model to clinically significant deterioration.

While previous research on deterioration has focused on identifying individuals at risk for negative outcomes, little is known about the nature or pattern by which deterioration occurs. The problem of deterioration is especially salient in training clinics; a setting in which higher deterioration rates have been reported. Two studies were designed to test the applicability of the phase model to deterioration in a training clinic and to replicate the model with a training clinic referral-base sample. In Study 1, the course of therapy was monitored for 135 clients. For the 38 clients who deteriorated during therapy, a model where increased symptoms (demediation) reliably preceded both decreased functioning (dehabilitation) and decreased well-being (demoralization) was found. In Study 2, the same three phases were prospectively monitored for 914 undergraduate students on a weekly basis throughout a single semester. For the 158 individuals who deteriorated during this time, a model where demediation reliably preceded dehabilitation, which preceded demoralization was found. These results have clinical implications for the use of tailored intervention strategies focusing on the deterioration phases. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Engineering Cardiac Tissues from Pluripotent Stem Cells for Drug Screening and Studies of Cell Maturation

Using cardiomyocytes derived from human pluripotent stem cells (hPSC-CMs), it is now possible to develop models of human cardiac diseases and to screen novel pharmaceutical agents on human cardiac cells and tissues. However, since hPSC-CMs display an immature phenotype, significant focus has turned to cardiac tissue engineering to deliver a means to mature these cells. In this review we discuss the maturation state of currently available hPSC-CMs and provide an overview of the processes involved in cardiomyocyte maturation. We then explore the differences between pathological and physiological hypertrophy and discuss how tissue engineering techniques that rely on the combined use of biomaterials and bioreactors can be utilized to enhance and study the hypertrophic response.     

Physicochemical changes in intermediate-moisture protein bars made with whey protein or calcium caseinate

This study examined model protein bars made with whey protein isolate (WPI) or calcium caseinate and stored at 20 °C for 50 days. WPI bars remained very soft and, throughout storage, confocal micrographs showed a continuous matrix containing soluble protein and increasing quantities of glucose crystals. In contrast, calcium caseinate bars had a firm texture within 1–5 days of manufacture (fracture stress 199 ± 16 Pa) and hardened progressively during storage (final fracture stress 301 ± 18 Pa). Electrophoresis showed no evidence of covalent protein aggregation, but there were substantial changes in microstructure over the first day of storage, resulting in segregation of a protein phase from a water–glucose–glycerol phase. Proton nuclear magnetic resonance (¹H-NMR) relaxometry and nuclear Overhauser effect spectroscopy (NOESY) experiments showed that water migration away from protein towards glucose and glycerol occurred 10–18 h after manufacture, lowering the molecular mobility of protein. Phase separation was probably driven by the high osmotic pressure generated by the glucose and glycerol. These results confirm that the hardening of protein bars is driven by migration of water from protein to glucose and glycerol, and microstructural phase separation of aggregated protein.     

High temperature and pressure alkaline electrolysis

This paper describes experimental work involving the direct-current electrolysis of highly concentrated potassium hydroxide solutions at high temperatures (up to 400 °C) and under various pressures. A high-temperature alkaline electrolysis cell resistant to chemical attack from the highly corrosive electrolyte solution and capable of high-pressure operation was designed and tested. The cell was constructed with a Monel^® alloy housing and cathode, while various anode materials were compared. The anode materials tested included nickel, Monel alloy, lithiated nickel, and cobalt-plated nickel. The advantages of operating an alkaline electrolysis cell at high temperatures include increasing the ionic conductivity of the electrolyte and enhancing the rates of electrochemical reactions at the electrode surfaces. Cell operation with increasing steam partial pressure over the solution is also shown to enhance cell performance. The prudent selection of anode material also impacts the required terminal potential for a given current density, and consequently the cell's electric power efficiency. The best cell performance was achieved using a cobalt-plated nickel anode at a temperature of 400 °C and a steam partial pressure of 8.7 MPa.     

Seeing the mean: Ensemble coding for sets of faces.

We frequently encounter groups of similar objects in our visual environment: a bed of flowers, a basket of oranges, a crowd of people. How does the visual system process such redundancy? Research shows that rather than code every element in a texture, the visual system favors a summary statistical representation of all the elements. The authors demonstrate that although it may facilitate texture perception, ensemble coding also occurs for faces—a level of processing well beyond that of textures. Observers viewed sets of faces varying in emotionality (e.g., happy to sad) and assessed the mean emotion of each set. Although observers retained little information about the individual set members, they had a remarkably precise representation of the mean emotion. Observers continued to discriminate the mean emotion accurately even when they viewed sets of 16 faces for 500 ms or less. Modeling revealed that perceiving the average facial expression in groups of faces was not due to noisy representation or noisy discrimination. These findings support the hypothesis that ensemble coding occurs extremely fast at multiple levels of visual analysis. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Large-Bar Connection for Precast Bridge Bents in Seismic Regions

A new beam-to-column connection has been developed for assembling precast concrete bridge bents in regions of high seismicity. The connection is made with a small number of large column bars, which are grouted into large corrugated-metal ducts embedded in the cap beam. Bents built with these connections can be erected quickly and permit generous construction tolerances. To evaluate the seismic performance of the proposed connection, lateral-load tests were performed on three manifestations of the connection, as well as on a comparable cast-in-place connection. The tests demonstrated that the force-displacement response and damage progression in the precast connection are similar to those of typical cast-in-place concrete connections. Deliberate partial debonding of the longitudinal reinforcement only slightly affected the force-displacement response and observed damage.     

柏莱沃古典音乐俱乐部:一座旧建筑的重生

柏莱沃古典音乐俱乐部是一个典型的建筑再生项目,原来是一座工厂,后来被改造为售楼处,如今再次被赋予新的生命,成为一处以古典音乐为主题的俱乐部。设计的挑战在于如何突破原有建筑的限制,寻求创新以满足各种不同的功能需求并表现音乐的特色。