Stability Studies of Agrifood Reference Materials Under Different Conditions of Storage by Near-Infrared Spectroscopy

Reference materials (RM) play an increasingly important role for laboratories. The aim of this work is to compare different conditions of storage and assess the stability of agrifood external reference materials (ERM). These materials could be used as tools by laboratories notably for their quality control procedure. However, as the other RM, their stability must be assessed during stability studies. The determination of the limiting date of stability (LDS), defined as the period during which analytes called marker of stability are still considered as stable, is used on this purpose. The influences of the environmental factor were tested by the application of full experimental designs with two tested environmental factors: the temperature (storage at +4 °C or +20 ± 10 °C) and the composition of the atmosphere (absence or presence of gases in the packaging). Thus, the setting under vacuum increases clearly the stability for the studied analyte. Almost all ERM stored in the best conditions have a determined LDS higher than those stored in current condition of storage. Indeed, the bread wheat ERM LDS is higher than the current storage of 24 months     

Placement of reference electrode in solid electrolyte cells

The placement of reference electrodes in solid state ionic conductors is not as flexible as in liquid state electrochemistry. This is in particular a problem when material from the gas phase is involved, as in solid oxide fuel cell. Many of the arrangements used are problematic: either they produce results that are very sensitive to electrode placement, change the potential distribution, do not provide a uniform current density and overpotential at the electrode or require delicate patterns liable to fail. We here present a new approach suitable for thin layer SOFC. It includes a calibration procedure derived from numerical simulations in combination with experiments. This allows the use of the common three-electrode arrangement on thin solid electrolyte (SEs) where the reference electrode is placed side by side with the working electrode, on an extension of the thin layer SE. This is so despite the sensitivity of that arrangement to both misalignment of the electrodes and to a difference in the impedance of the two current carrying electrodes. The misalignment tolerated, with the present method, may exceed the SE thickness. The allowed misalignment increases with the electrode/SE impedance ratio. The method copes also with the difference in the electrode impedance. Two special configurations are discussed in which the calibration is not required. However, these require a more accurate preparation technique of the cell.     

Online measurement of water content in candidate reference materials by acousto-optical tuneable filter near-infrared spectrometry (AOTF-NIR) using pork meat calibrants controlled by Karl Fischer titration

Certified reference materials (CRMs) are prepared from a wide variety of matrices. Water removal is an excellent way of achieving increased matrix lifetime and hence CRM stability. High-speed acousto-optical tuneable filter near-infrared spectrometry (AOTF-NIR) has been implemented for measurement of water content in powder matrix reference materials in amber glass vials. Almost 50,000 spectra were collected from 1300 to 2100 nm with a 2 nm increment for powders of meat, rye grass, potato, cotton seed and sugar beet. The AOTF-NIR instrument was placed in a capping machine, with a measurement frequency of 10–15 vials/min and a trigger signal for reproducible collection of spectra. The calibrants comprised 19 pork meat powder samples equilibrated with different hygrostatic solutions or subjected to oven drying to achieve different water concentrations. Mixtures of powders with different water content were also prepared in order to obtain a calibration range from 0.5 to 8.3% water (m/m). All calibration samples were measured by volumetric Karl Fischer titration (V-KFT), accredited under ISO 17025. The calibrants were then measured by AOTF-NIR together with the samples. Multiplicative scatter correction (MSC) was applied to the absorbance spectra in order to correct for the scattering of light in the different powders and scattering effects from the vials. A partial least squares regression model (PLS) based on two principal components was created and applied for prediction of water content in the samples with a standard error of 0.5% water (m/m).     

微型反应堆照射座内热中子通量谱的测定

一、基本原理用一组展开函数?_i(E)来表示所测的真实谱φ(E),典型的展开函数是一组N—1项的多项式,N是探测箔种类数。     

Optical Fiber Pressure Sensor with Reference channel^①

The principle of optical fiber pressure sensing probe with common diaphragm and the method for stabilizing the laser diodes are described in this paper at first.Then we discussed the improvement in characteristics of the system by means of taking the techniques of reference light channel and ratio measurement.     

Sampling-resampling techniques for the computation of posterior densities in normal means problems

Summary Implementation of Bayesian methods is complicated in many contexts by the apparent need for specialized numerical integration techniques, unfamiliar to most statistical practitioners. In fact, a shift of focus to a sampling-resampling perspective enables one to carry out Bayesian calculations without recourse to numerical integration. Such an approach is illustrated here in the familiar context of normal means inference problems, with particular focus on implementing analyses with reference priors.     

拓宽基础 开发意念──对未来建筑教育的思考

本文从分析建筑教育现状入手，展望未来建筑的发展及对人才的需要，为培养高层次，具有较大适应性和创造力的建筑师．提出了拓宽专业基础和开发设计意念的设想。     

Enabling the creation of domain-specific reference collections to support text-based information retrieval experiments in the architecture, engineering and construction industries

The increasing importance of text-based information retrieval (IR) developments in the architecture, engineering, and construction industries (AEC) and the lack of sharable testing resources to support these developments call for an approach that can be used to generate domain-specific reference collections. To address this need, the authors investigated the characteristics of the testing environment in AEC and ways to adapt dominant collection preparation methods for the domain. This paper presents the authors’ collection generation approach through the preparation process of the Taiwanese National Center for Research on Earthquake Engineering (NCREE) collection. The collection’s Chinese-to-English translation instruments are also discussed as matching semantic/linguistic resources are highly valued in AEC’s text-based IR developments. The paper also includes a use case for the NCREE collection to show how a collection generated by the proposed approach could be applied to support research experiment and validation. The direct outputs, the NCREE collection and its translation instruments, are sharable and reusable testing resources, while mechanisms for seeking collections from other researchers are part of the extended research endeavors.     

Design of nonlinear controllers for active vehicle suspension with state constraints

Design of active vehicle suspension has tradeoffs between three main performance metrics (passenger comfort, suspension deflection and road holding ability). It has been known that each performance can be achieved by H _∞ controller and they can be gathered by LPV (Linear Parameter Varying) method. However, because the suspension deflection limit was not explicitly considered, this limit may be exceeded. In this paper, the authors propose a “reference shaping“ based method in order to improve the control performance. In this approach, a “virtual reference” signal is imposed to the system such that the suspension deflection is kept small. The effectiveness of the approach is examined by numerical simulations. This work was presented in part at the 13th International Symposium on Artificial Life and Robotics, Oita, Japan, January 31–February 2, 2008     

架空输电线路基本风速的确定方法探讨

本文根据《110～750 kV架空输电线路设计规范》和《建筑结构荷载规范》的要求,提出了架空输电线路基本风速的确定方法,其结果大于设计手册公式和一般软件的计算结果,值得有关人员借鉴与参考.