Degradation of the insecticide azinphos methyl in orange and peach juices during storage at different temperatures

The degradation of azinphos methyl in orange and peach juice was studied. The insecticide was aseptically added to packed orange and peach juices and stored at 40, 20 and 0°C. Samples were removed at regular intervals and were analysed for residues of azinphos methyl. Residues were determined with a simple gas-chromatographic method using a 30m glass capillary column and an NP detector. The recoveries of azinphos methyl were 87-110% for orange juice and 92-108% for peach juice, and the limit of determination was 0.004mg/kg for both juices. From the experimental data, rate constants, half-lives, and times needed to reach legal limits for the decomposition of azinphos methyl in orange and peach juices were evaluated. Half-lives for orange and peach juices were 6.5 and 7.8 days at 40°C, 86.6, and 92.4 days at 20°C, and 407.7 and 495.1 days at 0°C, respectively.     

Influence of atomic layer deposition chemistry on high-k dielectrics for charge trapping memories

In this work we report the performance of the SiO₂/Si₃N₄/HfO₂ and SiO₂/Si₃N₄/ZrO₂ stacks with emphasis on the influence of atomic layer deposition chemistry used for forming the HfO₂ and ZrO₂ blocking layers. Two Hf precursors were employed – tetrakis(ethylmethylamino)hafnium (TEMAH) and bis(methylcyclopentadienyl)methoxymethyl hafnium (HfD-04). For ZrO₂, tetrakis(ethylmethylamino)zirconium (TEMAZ) and bis(methylcyclopentadienyl)methoxymethyl zirconium (ZrD-04) were used as metal precursors. Ozone was used as the oxygen source. The structural characteristics of the stacks were examined by transmission electron microscopy and grazing incidence X-ray diffraction. The electrical properties of the stacks were studied using platinum-gated capacitor structures. The memory performance of the stacks was evaluated by write/erase (W/E) measurements, endurance and retention testing. Endurance measurements revealed the most important difference between the stacks. The films grown from TEMAH and TEMAZ could withstand a significantly higher number of W/E pulses (>3 × 10⁵ in the 10 V/?11 V, 10 ms regime), in comparison to the stacks made from HfD-04 and ZrD-04 precursors (<5 × 10³ W/E cycles). This difference in endurance characteristics is attributed mainly to the different deposition temperatures suited for these two precursors and the nature of the layer formed at the Si₃N₄/HfO₂ and the Si₃N₄/ZrO₂ interfaces.     

Analytical modelling of plastic behaviour of uniformly FRP confined concrete members

A method is presented for the assessment and calibration of the elastoplastic behaviour of FRP confined concrete. The method is based on the evaluation of permanent deformations from observed experimental deformations and theoretical elastic response of confined concrete. The inelastic response of concrete and the parameters of its mathematical modelling are investigated. Closed form expressions are produced to relate the model parameters to the mechanical properties of the material. A strain-hardening Drucker–Prager model is developed which simulates both the hardening and softening material response with reasonable agreement to the experimental observations. The predictive ability of the model is verified through comparisons to numerous published experimental data and analytical models.     

The MoveOn database: motorcycle environment speech and noise database for command and control applications

The MoveOn speech and noise database was purposely designed and implemented in support of research on spoken dialogue interaction in a motorcycle environment. The distinctiveness of the MoveOn database results from the requirements of the application domain—an information support and operational command and control system for the two-wheel police force—and also from the specifics of the adverse open-air acoustic environment. In this article, we first outline the target application, motivating the database design and purpose, and then report on the implementation details. The main challenges related to the choice of equipment, the organization of recording sessions, and some difficulties that were experienced during this effort, are discussed. We offer a detailed account of the database statistics, the suggested data splits in subsets, and discuss results from automatic speech recognition experiments which illustrate the degree of complexity of the operational environment.     

Experimentelle und numerische Untersuchung des Tropfenaufstiegs

The results of an experimental and numerical investigation of an organic toluene droplet rising in a continuous aqueous phase are presented. The experiments were carried out in a small‐scale, high‐speed measuring unit. The numerical simulations were performed with the aid of the level set method implemented in the commercial CFD tool COMSOL Multiphysics 3.3a. Both measured and simulated terminal velocities are found to be in excellent agreement and match recent results. Moreover, the deviation from the spherical form is captured very well for different droplet sizes. Based on the experimental and numerical data obtained, an improvement of an existing terminal velocity correlation is suggested.     

框架结构弹塑性分析的一种有效数值方法

框架结构的不完全弹塑性分析是一个非线性过程,按照假定的加载模式,利用荷载因子进行逐步加载。基于力学和数值方法,研究框架结构的极限承载力和变形能力。假定材料为理想弹塑性,并利用零长度塑性铰模拟塑性行为。该方法基于增量方程,类似于求解两个连续塑性铰之间的凸二次参数规划问题。利用虚荷载因子将凸二次参数规划转化为凸二次规划,并使用标准算法求解凸二次规划问题,可满足出现塑性铰的要求并自动判别塑性。该方法起初仅适用于纯弯作用,后延伸至弯矩-轴力共同作用。分别分析单调、变化、循环加载作用下的算例。整个过程稳定、可靠、高效,并比基于直接刚度法的交替位移方法更省时。     

Wedge indentation of elastic–plastic layered substrates: Designing against contact-induced plasticity

The present paper investigates the indentation of plastically graded substrates by wedge indenters. Substrates made of graded materials are often encountered in nature or are artificially produced. The variation of the plastic properties depends on micro-structural or compositional changes of the material with depth. The introduction of certain controlled gradients in plastic properties can minimize plasticity and promote resistance to the onset of damage at contact surfaces during tribological applications. Contact analysis of plastically graded surfaces can be particularly useful in the design of load-bearing devices such as gears, rollers and electric contacts found in many macro- and micro-electro-mechanical systems. A comprehensive parametric finite element study of the mechanics of indentation of plastically graded materials by a rigid wedge is presented in the present paper. Of particular interest in the current investigation is the variation of the elastic modulus and the yield strength, of the type E = E₀ y₀/y and σ_Y = σ_Y0 y₀/y. This type of distribution is inspired from the material properties distribution of the human tooth. The results of this work show how surface modifications that result in certain plastic graded properties can strengthen substrates against contact-induced damage.     

A model for European Biogenic Volatile Organic Compound emissions: Software development and first validation

A grid-oriented Biogenic Emission Model (BEM) has been developed to calculate Non-Methane Volatile Organic Compound (NMVOC) emissions from vegetation in high spatial and temporal resolutions. The model allows the emissions calculation for any modeling domain covering Europe on the basis of: 1) the U.S. Geological Survey 1-km resolution land-use database, 2) a land-use specific, monthly isoprene, monoterpene and Other Volatile Organic Compound (OVOC) emission potentials and foliar biomass densities database, 3) temperature and solar radiation data provided by the mesoscale meteorological model MM5. The model was applied for Europe in 30-km spatial resolution for the year 2003. The European total emissions for 2003 consist of 33.0% isoprene, 25.5% monoterpenes and 41.5% OVOC. BEM results are compared with those from the well-documented global Model of Emissions of Gases and Aerosols from Nature (MEGAN). The BEM total emissions compare well with the MEGAN ones. In July 2003, the results of both models agree within a factor of 1.2 for total isoprene emissions and within a factor of 2 for total monoterpene emissions. The comparison of the spatial distributions of the July 2003 isoprene and monoterpene emissions calculated with BEM and MEGAN shows that, in the greater part of the study area, the differences are below the current uncertainty limit for the estimation of spatially-resolved biogenic VOC emissions in Europe being equal to about ±600 kg km^?2 month^?1. Differences that are above this limit are found mainly in the eastern European countries for isoprene and in the Mediterranean countries for monoterpenes.