Full-Scale Field Testing of Colloidal Silica Grouting for Mitigation of Liquefaction Risk

This paper reports results of a full-scale field test to assess the performance of dilute colloidal silica stabilizer in reducing the settlement of liquefiable soil. Slow injection methods were used to treat a 2-m-thick layer of liquefiable sand. Eight injection wells were installed around the perimeter of the 9-m-diameter test area and 8% by weight colloidal silica grout was slowly injected into the upper 2?m of a 10-m-thick layer of liquefiable sand. A central extraction well was used during grout injection to direct the flow of the colloidal silica towards the center of the test area. Details of the field injection are described. Subsequently, the injection wells were used to install explosive charges and liquefaction was induced by blasting. After blasting, approximately 0.3?m of settlement occurred versus 0.5?m of settlement in a nearby untreated area. The mechanism of improvement is thought to be bonding between the colloidal silica and the individual sand particles; the colloidal silica gel encapsulates the soil structure and maintains it during dynamic loading.     

CMOS为移动通信设备设置影像标准

CMOS传感器具有许多CCD传感器无法比拟的优点,比如更快的帧速率,更少的元件数目,更低的系统成本和更低的耗电量.本文将与您一起探讨CMOS图像传感器将如何改变移动通信设备.     

Optimization of Alumina and Aluminosilicate Aerogel Structure for High-Temperature Performance

Alumina and aluminosilicate aerogels offer potential for use at temperatures above 700°C, where silica aerogels begin to sinter. Stability of alumina and aluminosilicate pore structures at high temperatures is governed by the starting aerogel structure, which, in turn is controlled by the synthesis route. Structure, morphology, and crystallization behavior are compared for aerogels synthesized from AlCl₃ and propylene oxide with those synthesized from a variety of boehmite precursors. The aerogels possessing a crystalline boehmite structure in the as-synthesized condition retained mesoporous structures to temperatures of 1200°C, while the AlCl₃-derived aerogels, although exhibiting higher as-synthesized surface areas, crystallized and densified at 980–1005°C.     

Determining human exposure and sensory detection of odorous compounds released during showering

Modeling of human exposure to aqueous algal odorants geosmin (earthy), 2-methylisoborneol (musty), and (trans,cis)-2,6-nonadienal (cucumber, fishy), and the solvent trichloroethylene (sweet chemical), was investigated to improve the understanding of water-air transfer by including humans as sensors to detect contaminants. A mass-transfer model was employed to determine indoor air concentrations when water was used for showering under varying conditions (shower stall volume, water and air flow rate, temperature, aqueous odorant concentration, shower duration). Statistical application of multiple linear regression and tree regression were employed to determine critical model parameters. The model predicted that concentrations detectable to the human senses were controlled by temperature, odor threshold, and aqueous concentration for the steady-state model, whereas shower volume, air flow, and water flow are also important for the dynamic model and initial detection of the odorant immediately after the showering is started. There was excellent agreement of model predictions with literature data for human perception of algal odorants in their homes and complaints to water utilities. TCE performed differently than the algal odorants due to its higher Henry's law constant, in spite of similar gas and liquid diffusivities. The use of nontoxic odorants offers an efficient tool to calibrate indoor air/water shower models.     

Standardization of models and methods used to assess nanoparticles in cardiovascular applications

Nanotechnology has the potential to revolutionize the management and treatment of cardiovascular disease. Controlled drug delivery and nanoparticle-based molecular imaging agents have advanced cardiovascular disease therapy and diagnosis. However, the delivery vehicles (dendrimers, nanocrystals, nanotubes, nanoparticles, nanoshells, etc.), as well as the model systems that are used to mimic human cardiac disease, should be questioned in relation to their suitability. This review focuses on the variations of the biological assays and preclinical models that are currently being used to study the biocompatibility and suitability of nanomaterials in cardiovascular applications. There is a need to standardize appropriate models and methods that will promote the development of novel nanomaterial-based cardiovascular therapies.     

The effect of different mixing processes on dough extensional rheology and baked attributes

BACKGROUND: Mixing is a significant part of the breadmaking process and is responsible for the development of the essential structure that will facilitate gas retention during proofing and the early stages of baking. The main objective of this study was to examine whether the dough extensional rheological and baking properties were affected from different mixers and energy inputs during mixing. RESULTS: It was found that extensional properties in uniaxial and biaxial extension were affected by the mixing equipment used and by the energy input used. Doughs mixed using a Farinograph had higher maximum resistance to uniaxial extension, higher P value and lower biaxial extensibility (Alveograph) and higher biaxial extensional viscosity than doughs mixed in a Stephan mixer (P < 0.01). The energy input was specific to each type mixing equipment and affected the biaxial extensional viscosity. Also, higher loaf volumes were achieved when higher energy inputs were used, whereas other baking properties were not affected. CONCLUSION: Altering the mixing equipment and the mixing speed affected the rheological properties of dough. Dough development during proofing as well as loaf volume was affected by the energy input levels and was increased by increasing the energy input and therefore the mixing time. Copyright © 2010 Society of Chemical Industry     

Differential recall as a function of mood disorder in clinically depressed patients: Between- and within-subject differences.

In Study 1, 23 depressed outpatients (aged over 60 yrs); 23 controls matched to the depressed group on age, sex, education, and SES; and 23 undergraduates rated trigrams as liked or disliked and were asked to recall a portion of these after a study period. Results show that depressed Ss recalled more trigrams they had disliked than ones they had liked. Both control groups had the opposite pattern, but undergraduates recalled significantly more trigrams than did older Ss. In Study 2, 20 of the 23 depressed Ss from Study 1 were administered different trigram packets at the middle and end of therapy using the same procedure. Results show that the change from a depressed to a nondepressed state across therapy correlated with a change from the superiority of disliked trigrams in the recall to a superiority of liked trigrams. It is suggested that this simple differential-recall procedure can be used as a moderate measure of the continuum of depression and success in therapy. (32 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effects of opioid microinjections into the medial septal area on spatial memory in rats.

Recent work has demonstrated that posttraining systemic opioid antagonist administration facilitates the acquisition of a radial arm maze task in new spatial environments. In this study, we examined the effect of posttraining naloxone and β-endorphin microinjections into the medial septal area on the acquisition of a radial maze task in new spatial environments. The results of these experiments demonstrated that posttraining intraseptal naloxone administration facilitated, whereas posttraining intraseptal β-endorphin administration impaired, the acquisition of criterion performance on a maze task performed in new spatial environments. Further, intraventricular β-endorphin administration did not produce effects that were comparable to those observed following intraseptal β-endorphin administration, which indicates that the septal region is a brain site that is sensitive to the effects of opioids on spatial memory in new environments. Further, posttraining intraseptal β-endorphin administration had no effect on working memory in a familiar spatial environment, whereas pretraining intraseptal β-endorphin administration had no effect on the performance of a previously acquired spatial task. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Impact of early socialization on union commitment and participation: A longitudinal study.

New members of a union (N?=?305) were surveyed twice over a 1-year period to assess the effects of institutional and individual socialization practices on union commitment and participation. Whereas individual socialization practices were found to impact on both affective and behavioral involvement in the union, institutional socialization practices were shown to be ineffective at best and counterproductive at worst. The theoretical and practical implications of the findings are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A three‐dimensional mesh refinement algorithm with low boundary reflections for the finite‐difference time‐domain simulation of metallic structures

We present a method for including areas of high grid density into a general grid for the finite‐difference time‐domain method in three dimensions. Reflections occurring at the boundaries separating domains of different grid size are reduced significantly by introducing appropriate interpolation methods for missing boundary points. Several levels of refinement can be included into one calculation using a hierarchical refinement architecture. The algorithm is implemented with an auxiliary differential equation technique that allows for the simulation of metallic structures. We illustrate the performance of the algorithm through the simulation of metal nano‐particles included in a coarser grid and by investigating gold optical antennas. Copyright © 2009 John Wiley & Sons, Ltd.