Some Characteristics of Free Cell Population in the Airways of Rats after Intratracheal Instillation of Copper-Containing Nano-Scale Particles

We used stable water suspensions of copper oxide particles with mean diameter 20 nm and of particles containing copper oxide and element copper with mean diameter 340 nm to assess the pulmonary phagocytosis response of rats to a single intratracheal instillation of these suspensions using optical, transmission electron, and semi-contact atomic force microscopy and biochemical indices measured in the bronchoalveolar lavage fluid. Although both nano and submicron ultrafine particles were adversely bioactive, the former were found to be more toxic for lungs as compared with the latter while evoking more pronounced defense recruitment of alveolar macrophages and especially of neutrophil leukocytes and more active phagocytosis. Based on our results and literature data, we consider both copper solubilization and direct contact with cellular organelles (mainly, mitochondria) of persistent particles internalized by phagocytes as probable mechanisms of their cytotoxicity.     

Design certification with information-gap uncertainty

This paper presents a concept for formulating structural design-codes which is based on information-gap models of uncertainty rather than on probabilistic concepts. Info-gap models quantify uncertainty as the size of the gap between what is known and what could be known. Info-gap models of uncertainty are particularly useful when data on the uncertainties are quite limited. In the proposed procedure a design is certified if the robustness to failure from uncertain fluctuations exceeds a code-specified threshold. Design is thus based on immunity to uncertainty rather than on probability of survival. The key conclusion is that design-certification can exploit data about uncertainties without introducing probabilistic models. This is important when information is scarce, since verification of probabilistic models can then be difficult. Second, when partial probabilistic information is available, it can be incorporated in a hybrid info-gap/probabilistic analysis. Third, the proposed design certification incorporates recognition of the dual nature of uncertainty: that it may be pernicious but may also entail propitious possibilities. Examples are presented which illustrate the design procedure. The incorporation of partial probabilistic information is also demonstrated. The antagonism between the pernicious and propitious potentials of ambient uncertainty is illustrated.     

Synthesis and characterization of grafted copolymers of aromatic polyimides and ε‐caprolactam

Anionic polymerization of ε‐caprolactam was performed in the presence of only 5 wt % of aromatic polyimides having five‐ and six‐membered imide cycles and bearing hexafluoroisopropylidene, ether, fluorene, siloxane, phthalide, or SO₃H? groups, both in the polymer backbone and as side moieties. The synthesized new copolymers were fully characterized by IR spectroscopy, thermomechanical analysis, dilatometry, and X‐ray diffraction. Tough and frictional properties of the obtained copolymers were estimated as well. It was found that on the selection of polyimide activator it is possible to gain the desirable control over the polymer properties, namely the gel‐fraction content, phase composition, compression modulus, notched Izod impact strength, temperature of frictional contact, friction coefficient, etc. These investigations will facilitate the choice of the optimum macromolecular activator for the modification of both the synthetic method and the properties of the commercial polycaproamide. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

On dynamic irreversibilites

Industrial energy systems experience time-dependent temperature variations in a heat-transfer apparatus. These variations introduce dynamic irreversibilities in the thermodynamic cycles. To account for these, a modified and discretely reversible sample cycle is introduced and described. Simple examples are used to illustrate aplication of the cycle to thermal efficiency analysis.     

Info-gap robustness for the correlation of tests and simulations of a non-linear transient

An alternative to the theory of probability is applied to the problem of assessing the robustness, to uncertainty in model parameters, of the correlation between measurements and computer simulations. The analysis is based on the theory of information-gap uncertainty, which models the clustering of uncertain events in families of nested sets instead of assuming a probability structure. The system investigated is the propagation of a transient impact through a layer of hyper-elastic material. The two sources of non-linearity are (1) the softening of the constitutive law representing the hyper-elastic material and (2) the contact dynamics at the interface between metallic and crushable materials. The robustness of the correlation between test and simulation, to sources of parameter variability, is first studied to identify the parameters of the model that significantly influence the agreement between measurements and predictions. Model updating under non-probabilistic uncertainty is then illustrated, based on two complementary immunity functions: the robustness to uncertainty and the opportunity from uncertainty. Finally an info-gap model is embedded within a probability density function to represent uncertainty in the knowledge of the model's parameters and their correlation structure. Although computationally expensive, it is demonstrated that info-gap reasoning can greatly enhance our understanding of a moderately complex system when the theory of probability cannot be applied due to insufficient information.     

Determination of spatial distribution in two-phase flow using scattered gamma radiation

A procedure has been developed and tested for measurement of the phase distribution along a chord of the flow channel in steady state two-phase flow. The method involves measurement of the zeroth and first moments of the energy spectra of Compton scattered radiation. This information allows determination of the mean position and thickness of each condensed phase region along the interrogated chord in the flow channel. Preparation of empirical calibration curves employing perspex disks, rods or tubes is explained. An iterative procedure for correcting the calibration curves for self-absorption is developed. The procedure has enabled determination of the position and thickness to within a few percent in simulated steady state tests.     

Safety implications of stochastic analysis of nuclear reactor transients

A ‘neutron-temperature random process’ is formulated by means of a probability generating function technique. The model accounts for the effect of the negative temperature feedback by treating the temperature as a continuous random variable, thereby making possible the computation of the expected values of the temperature, neutron and cumulative fission densities as well as their standard deviations. The special relationship of the stochastic behavior of the nuclear reactor to safety considerations is discussed. Typical numerical results are presented related to startup accidents and Anticipated Transient Without Scram (ATWS) in thermal reactors.     

MIPS：高效处理器架构推动新一代个人移动设备

MIPS战略市场经理Yakov Levy认为从PMP到MID,个人移动设备市场将在2009年迅猛增长。这些设备的基本功能与机顶盒和IPTV等其他高性能、功能丰富的多媒体设备基本相同。不同的是这些设备需要更好、更直觉的用户界面所带来的高速、高分辨率和个人电脑体验。消费者不断要求为他们提供独特和非常人性化体验的个人移动设备。     

EEG source localization using a sparsity prior based on Brodmann areas

Localizing the sources of electrical activity in the brain from electroencephalographic (EEG) data is an important tool for noninvasive study of brain dynamics. Generally, the source localization process involves a high‐dimensional inverse problem that has an infinite number of solutions and thus requires additional constraints to be considered to have a unique solution. In this article, we propose a novel method for EEG source localization. The proposed method is based on dividing the cerebral cortex of the brain into a finite number of “functional zones” which correspond to unitary functional areas in the brain. To specify the sparsity profile of human brain activity more concisely, the proposed approach considers grouping of the electrical current dipoles inside each of the functional zones. In this article, we investigate the use of Brodmann's areas as the functional zones while sparse Bayesian learning is used to perform sparse approximation. Numerical experiments are conducted on a realistic head model obtained from segmentation of MRI images of the head and includes four major compartments namely scalp, skull, cerebrospinal fluid (CSF), and brain with relative conductivity values. Three different electrode setups are tested in the numerical experiments. The results demonstrate that the proposed approach is quite promising in solving the EEG source localization problem. In a noiseless environment with 71 electrodes, the proposed method was found to accurately locate up to 6 simultaneously active sources with accuracy >70%.     

Stress relaxation in low‐shrink‐force polyolefin films

The morphology and stress relaxation of coextruded five‐layer LLDPE (linear low‐density polyethylene)/EVA (ethylene‐vinyl‐acetate) copolymer films were studied. Increasing VA (vinyl acetate) content in EVA causes a decrease of shrink tension in the films, which can be explained by a decrease in amount of crystallinity. The relaxation time spectrum of the coextruded crosslinked LLDPE/EVA films is similar to the relaxation time spectrum of crosslinked LLDPE film at room temperature. However, at elevated temperatures, an additional peak appears on the spectrum of coextruded film. The cause of this peak is temperature‐ and stress‐induced recrystallization of EVA during the relaxation test. This recrystallization was confirmed with DSC and wide angle X‐ray analysis. Polym. Eng. Sci. 44:1716–1720, 2004. © 2004 Society of Plastics Engineers.