Mars analysis by laser-induced breakdown spectroscopy (MALIS): influence of mars atmosphere on plasma emission and study of factors influencing plasma emission with the use of doehlert designs

A project called MALIS (Mars Analysis by Laser-Induced breakdown Spectroscopy) is under progress to perform in situ analysis of Mars soils and rocks. This paper reports on the behavior of plasma in Martian conditions, i.e., in a CO2 atmosphere at pressures between 5 and 12 mbar. Plasma expansion and lifetime have been studied in order to compare plasma evolution under standard conditions (air at atmospheric pressure) and in a Mars atmosphere. We have shown that the Mars environment favors plasma expansion and lifetime. The second part of the study concerns optimization of the emission signal from the plasma. An original approach has been chosen, as we used a Doehlert design for the first time in laser-induced breakdown spectroscopy (LIBS). The best conditions obtained are for a laser wavelength of 1064 nm with the maximum energy available due to space limitations, which is 40 mJ at 15 Hz. The other factors studied are delay, angle of incidence, and CO2 pressure. We have shown that these factors do not have the same influence depending on which spectroscopic line is used, i.e., the atomic line or the ionic line.     

Prof. Dr. Geert De Schutter, 2001 Robert L'hermite Medallist

RILEM Bulletin

Prof. Dr. Geert De Schutter, 2001 Robert L'hermite Medallist     

Investigation of 3-D mechanical properties of blood vessels using a new in vitro tests system: results on sheep common carotid arteries

In order to investigate the three-dimensional (3-D) mechanical properties of blood vessels, a new experimental device is described allowing in vitro static and dynamic measurements on segments of arteries with high technical performances. Static tests are applied to sheep common carotid arteries. Considering a thick-walled cylindrical model of orthotropic material under large deformations, a classical 3-D approach based on strain energy density is used to calculate the resulting mechanical behavior law in radial and circumferencial directions and stresses distribution throughout the wall thickness. Results are presented with reference to unloaded and zero-stress initial state thanks to simple measurements of inner and outer circumferences. A particular ratio relating the two main stresses (circumferential and longitudinal) is calculated that put into the forth the progressive modifications in the direction of the predominant stress in the wall and the specific radial location where these changes occur. The authors observe that this point location is a function of the test conditions of the specimen, i.e., stretching length and level of pressure     

Distance semantics for database repair

In many scenarios, a database instance violates a given set of integrity constraints. In such cases, it is often required to repair the database, that is, to restore its consistency. A primary motif behind the repairing approaches is the principle of minimal change, which is the aspiration to keep the recovered data as faithful as possible to the original (inconsistent) database. In this paper, we represent this qualitative principle quantitatively, in terms of distance functions and some underlying metrics, and so introduce a general framework for repairing inconsistent databases by distance-based considerations. The uniform way of representing repairs and their semantics clarifies the essence behind several approaches to consistency restoration in database systems, helps to compare the underlying formalisms, and relates them to existing methods of defining belief revision operators, merging data sets, and integrating information systems.      

Hardware architectures for the Tate pairing over GF(2)

In this paper two different approaches to the design of a reconfigurable Tate pairing hardware accelerator are presented. The first uses macro components based on a large, fixed number of underlying Galois Field arithmetic units in parallel to minimise the computation time. The second is an area efficient approach based on a small, variable number of underlying components. Both architectures are prototyped on an FPGA. Timing results for each architecture with various different design parameters are presented.     

综合先进技术的交通噪音评估(一)-以立体地理资讯系统为基础的区域噪音模型

为了解、组织及整理整个香港区域的道路交通噪音资料,从而确定、量化及分折交通噪音的严重性,再鉴定相关的噪音缓解措施,香港环境保护署综合了数种先进的技朮,包括地理信息系统、大型的电脑噪音模型、立体影像技朮等,自行开发了一套以立体地理资讯系统为基础的区域噪音模型。从这个系统和模型计算出来的交通噪音地图,加上利用地理信息系统軟件、人口分布的资料库和统计学方法的帮助,评估了整个城市总共有多少居民在那些区域受着多少交通噪音的影响。这些结果可以分析交通噪音的问题,继而决定未来噪音缓解设施及制定综合的计划,以应付这噪音问题。     

TIME OPERATOR IN QUANTUM MECHANICS AND SOME STOCHASTIC PROCESSES WITH LONG MEMORY

Time operator describes the lifetime of quantum irreversible processes on the level of statistical states. The existence, interpretation, and properties of time operator are discussed and the master equation is derived. Time operator exists also in other dynamical systems with mixing properties. Models of non-Markovian processes with long memory having a time operator are discussed.     

Selective Metal Pattern Fabrication Through Micro-Contact or Ink-Jet Printing and Electroless Plating onto Polymer Surfaces Chemically Modified by Plasma Treatments

Simple versatile processes combining plasma treatments, micro-contact printing (µCP) or ink-jet printing (IJP), and electroless deposition (ELD) have been developed to produce micrometer and sub-micrometer scale metal (Ni, Ag) patterns at the surface of polymer substrates. Plasma treatments were mainly used to graft the substrate surfaces with either nitrogen-containing functionalities on which a palladium-based catalyst can be subsequently chemisorbed (case of Ni deposition through a tin-free process in solution) or oxygen-containing functionalities on which a tin-based sensitization agent can be subsequently chemisorbed (case of Ag deposition through a redox reaction). µCP of the catalyst or of self-assembled monolayers (SAMs) as well as ink printing were used to obtain locally active or non-active areas at the polymer surfaces. The metal micro-patterns were characterized using optical microscopy, scanning electron microscopy (SEM), and atomic force microscopy (AFM). Surface chemical characterization was carried out by X-ray photoelectron spectroscopy (XPS).     

COMPARISON OF TWO ANALYTICAL METHODS FOR THE DETERMINATION OF AZAARENES IN ATMOSPHERIC PARTICULATE MATTER

In this paper, the development of an analytical method for the separation and quantification of 20 azaarenes is described. Two methods are compared: high performance liquid chromatography with fluorescence detection (HPLC-fluorescence) and gas chromatography with mass spectrometry detection (GC-MS).

Although HPLC-fluorescence was proven to be the most sensitive method, GC-MS was selected in particular for the efficiency of the separation of the 20 azaarenes. The detection limits of the HPLC-fluorescence and GC-MS methods varied between 0.04 μ g.L^?1 (dibenz[a,c]acridine) and 1.30 μ g.L ^?1 (acridine) and between 1.50 μ g.L ^?1 (benz[c]acridine) and 2.56 μ g.L ^?1 (dibenz[a,c]acridine) respectively.

The GC-MS method was applied to particulate matter (PM ₁₀ ) samples collected over 48–72 h periods between April 2006 and February 2007 in Strasbourg (East of France). Before analysis aerosol samples were Soxhlet extracted and concentrated to a final volume of about 1 mL of hexane.

The seasonally mean concentrations of all azaarenes for this urban site have shown a seasonal variation in which the maximum concentration occurred in the winter (6.0 ng.m ³ ) and the minimum in the summer (0.90 ng.m³). For all the seasons the 2 rings species were the predominant azaarenes while the > 4 rings species were the less abundant.     

Awareness of coeliac disease and the gluten status of ‘gluten‐free’ food obtained on request in catering outlets in Ireland

The only current effective treatment for coeliac disease (CD) is a lifelong diet that is as free from gluten as possible. This study provides baseline evidence to inform future interventions of benefit to CD sufferers by examining awareness of CD issues by food servers and preparation staff, assessing their claims to provide gluten‐free foods by analysis of a meal concurrently sampled. While the majority of attempts to purchase a ‘gluten‐free’ meal on request in restaurants were successful, some 10% of all samples contained gluten, 2.7% between 21 and 100 mg kg^?1, and 7.7% >100 mg kg^?1 and two unsatisfactory samples were purchased from so‐called coeliac‐friendly restaurants. These findings were consistent with those obtained previously by Collin et al. [Alimentary Pharmacology & Therapeutics 19 (2004) 1277], Størsrud et al. [European Food Research & Technology 217 (2003) 481], Gélinas et al. [International Journal of Food Science & Technology 43 (2008) 1245] for cross contamination with gluten. Staff confidence, ‘gluten‐free’ notices, signs and menu choices were no guarantee of risk‐free dining for CD sufferers. Based on our findings we suggest the need for further training, specifically for chefs and managers.