Fugitive Diffusion Barrier for Integration of Sol-Gel-Derived Lead Titanate with Oxidized Silicon Substrates

The crystalline phase development and microstructural changes with heating of sol-gel-derived lead titanate (PT) particles and films on silica with and without a fugitive (or removable) diffusion barrier layer were investigated. Amorphous gel-derived PT particles were deposited on SiO₂-coated TEM grids with and without polyimide (PI) or carbon barrier layers between SiO₂ and PT. TEM analysis showed that PI or carbon barriers prevented reaction between the gel-derived PT particles and SiO₂. PT particles crystallize and then the PI or carbon film decomposes. Sol-gel-derived PT films were deposited on oxidized Si substrates (Si/SiO₂) with and without a PI barrier layer. Perovskite PT films were prepared on Si/SiO₂ substrates with a PI barrier; however, some porosity remained in the films. Identically prepared films without the PI barrier formed a mixture of pyrochlore and perovskite. X-ray photoelectron spectroscopy results indicate that the PI film pre- vents the diffusion of Si into the PT film.     

The effects of feedback on performance and retention of skill for a natural language interface

This study investigated the effectiveness of different types of on-line feedback following user errors for informing users of the information and functions available in a system with a natural language interface. Twenty-four individuals performed a task based on an industry cost savings program, in which they were given general goals to pursue with regard to the task. Three feedback levels which differed according to the type and amount of feedback provided, along with two levels of system complexity, were examined. In addition, subjects performed the task again after one week to determine the effects of feedback on retention. Results indicated that the subjects in the second level of feedback generally performed better with respect to accessing system functions and information than those in the first level. Although there was some performance improvement from the second to third level, it was not significant. However, the third level of feedback did significantly improve the efficiency with which subjects used information to complete the task during the return condition. Overall, feedback did not affect the errors made, though at certain more limited stages of the tasks this effect was observed.     

Silicon Valley Policy

Silicon Valley is hom e to the m ostdynam ic industries in the C aliforniaeconom y .These industries —— thehigh-tech sector—— are driven by in-novation,and each new wave of inno-vation is usually led by cre ativeentrepreneurs starting new firm s.D uri…     

Electrostatic Charging and Levitation of Helium II Drops

Liquid Helium II drops, of diameter 1 mm or less, are charged with positive helium ions and subsequently levitated by static electric fields. Stable levitation was achieved for drops of order 100–150 micrometers in diameter. The suspended drops could be translated to arbitrary positions within the levitator using additional superimposed DC electric fields, and also could be made to oscillate stably about their average positions by means of an applied time-varying electric field. A weak corona discharge was used to produce the necessary ions for levitation. A novel superfluid film flow device, developed for the controlled deployment of large charged drops, is described. Also discussed is an adjustable electric fountain that requires only a field emission tip operating at modest potentials, and works in both Helium I and Helium II.     

Ultrasonographically-guided fine-needle aspiration cytology in the diagnosis of colonic lesions

BACKGROUND: The use of fine-needle aspiration cytology (FNAC) in the diagnosis of colonic lesions was investigated. METHODS: Some 22 patients (median age 71 years) with a colonic lesion identified on abdominal ultrasonography underwent ultrasonographically-guided FNAC using a 21-G needle. The sample was checked immediately by a cytopathologist for adequacy. RESULTS: Eighteen patients had colonic carcinoma; aspiration cytology detected malignant epithelial cells consistent with colonic carcinoma in 17 patients and severely dysplastic cells in one patient. The sensitivity and specificity of ultrasonographically-guided FNAC in the diagnosis of colonic carcinoma was 94 and 100 per cent respectively. The remaining four patients had a diagnosis of ileocaecal tuberculosis, ileocaecal Crohn's disease, and metastatic adenocarcinoma in the liver with no identifiable primary (two patients). One demonstrated granulomata, grew acid-fast bacilli and the patient was treated for tuberculosis. One had inflammatory cells and the patient was found to have Crohn's disease on histology. The remaining two patients had confirmed metastatic adenocarcinoma in the liver on aspiration cytology but suspected colonic lesions were found to be benign on cytological examination and no primary lesion was subsequently demonstrated. There were no complications of FNAC and patients complained of minimal discomfort. There has been no evidence of tumour recurrence with a median follow-up of 12 (range 1-25) months. CONCLUSION: Ultrasonographically-guided FNAC is a valid method for the diagnosis of colonic tumours.     

The moderating influence of attitude strength on the susceptibility to context effects in attitude surveys.

In 3 experiments, the authors assessed whether attitude strength moderates the susceptibility of attitudes to item context effects in surveys. In Experiment 1, respondents completed multiple measures of attitude strength. Three weeks later, respondents participated in a context experiment. Results revealed that respondents with weak attitudes exhibited significantly larger context effect for 1 of 2 issues. In Experiment 2, the results of Experiment 1 were conceptually replicated by use of measures of interattitudinal embeddedness to assess attitude strength. In Experiment 3, significant strength-moderated context effects were found when attitude strength was assessed in a multi-item, multidimensional manner but not when it was assessed with a single item. Discussion focuses on measurement and theoretical issues related to the moderation and mediation of context effects in attitude surveys. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Do you have an internet acceptable use policy?

No longer is the question if the Internet will be used in the classroom but when the Internet will be used in the classroom. Superimposing this technology on procedural teaching methods in the highly regulated and structured environment known as public education is akin to managing chaos. The confusion experienced by educators at all levels is not unlike similar sentiments expressed by other professionals having survived rapid organizational changes in the business world over the period of the past five to seven years. With this in mind, an attempt to define educators' proactive responsibilities in preparation for these changes led to an extensive review of literature and a survey by one of the authors. A necessary first step in embracing technological changes in education is the development of an Internet Acceptable Use Policy. A policy shell is provided that can be used to formulate individual school policy.     

Connecting the dots: Understanding the interrelated impacts of type,quality and children's awareness of design features and the mathematics content learning goals in digital math games and related learning outcomes

This study focused on an examination of how type, quality and children's awareness of design features in digital math games, along with an awareness of the mathematics goals of the game, were related to learning outcomes. We conducted a parallel conversion mixed methods study with 45 students in Grades 3 and 4 (ages 9–10). Students participated in clinical interviews using three digital math games. The results suggest a moderated mediation relationship in which the quality of the design features moderated the mediating impact of children's awareness of the game's design features, specifically when the child was aware of the mathematics content learning goal (MCLG) of the game. These findings show how important it is that design features are of high quality in a digital math game, and how this is intertwined with children's awareness of the features and the MCLG. When these variables intertwined in just the right way, the interactions between the children and the digital math game afforded mathematical learning growth.