The lock‐in phase in the urotropine–sebacic acid system

The 1,10‐decane­dioic acid–1,3,5,7‐tetra­aza­tri­cyclo­[3.3.1.1^3,7]­decane (1/1) system, C₁₀H₁₈O₄·C₆H₁₂N₄, was studied at 215 (2) K. Its analysis provides important information with regard to the long‐standing acid–carboxyl­ate controversy in the urotropine–alkanedioic acid system. In the present structure, all the chain end‐groups display a clear acid character. The asymmetric unit of this commensurate modulated phase contains two mol­ecules of diacid as well as two mol­ecules of urotropine. Furthermore, the chain packing suggests a possible order parameter for the lock‐in transition.     

Memory effects and homogenization

Dedicated to Bernard D. Coleman on his sixtieth birthday     

Comparison of PIV parameters effects on displacement identification and cross correlation

An algorithm is presented to determine displacements thanks to the identification method. Its main properties are described: no link with the particle size, measurement of the velocity distribution. Determination of effects of PIV parameters on displacement identification is made. Parameters used are noise, bias, velocity distribution. Therefore, we can define a validity domain of PIV parameters for identification and compare it with the domain of cross correlation. The identification validity range is based on 70% of isolated particles, on a displacement norm and on displacement gradients corresponding to less than half the size of the interrogation cell and to 10% of the average velocity. The comparison with cross correlation domains indicates that the cross correlation is more robust. However, the identification method is interesting because of the possibility of displacement distribution measurement. We use it to measure the decreasing of the turbulence intensity for a grid-generated turbulence.     

Random Version of the Theorems of the Alternative

Three theorems of the alternative for abstract linear inequality systems which depend on random parameter are produced in infinite dimensions.     

Blends of carbon blacks and multiwall carbon nanotubes as reinforcing fillers for hydrocarbon rubbers

The reinforcement of a styrene‐butadiene rubber (SBR) by single fillers—carbon black (CB) or multiwall carbon nanotubes (MWNTs)—or by mixtures of CB and MWNTs, is investigated. The morphologies, mechanical and electrical properties of the composites, are analyzed. A significant improvement in the tensile properties is observed for samples containing a dual phase. Using atomic force (AFM) and transmission electron (TEM) microscopies, we demonstrate that the double loading improves the dispersion of the nanotubes in SBR. Electrical measurements show lower resistivity and a lower percolation threshhold for composites containing blends of fillers, which provides further evidence of better dispersion. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci 46: 1939–1951, 2008     

Analysis of an industrial component commonality problem

We discuss a case study of an industrial production-marketing coordination problem involving component commonality. For the product line considered, the strategic goal of the company is to move from the current low volume market to a high volume market. The marketing department believes that this can be achieved by substantially lowering the end products’ prices. However, this requires a product redesign to lower production costs in order to maintain profit margins. The redesign decision involves grouping end products into families. All products within one family use the same version of some components. This paper fits in the stream of recent literature on component commonality where the focus has shifted from inventory cost savings to production and development cost savings. Further, we consider both costs and revenues, leading to a profit maximization approach. The price elasticity of demand determines the relationship between the price level and number of units sold. Consequently, we integrate information from different functional areas such as production, marketing and accounting. We formulate the problem as a net-present-value investment decision. We propose a mixed integer nonlinear optimization model to find the optimal commonality decision. The recommendation based on our analysis has been implemented in the company. In addition, the application allows us to experimentally validate some claims made in the literature and obtain managerial insights into the trade-offs.     

Isotopic characteristics of the Garonne River and its tributaries

The Garonne is the largest river in the south‐west of France, and its drainage basin stretches between the Pyrénées and the Massif Central mountains. Until now, no water stable isotope study has been performed on the whole Garonne river basin which is composed of different geological substrata, and where the water resources are limited during the dry summer period. This study focuses on the Garonne river and its tributaries from the Pyrénées foothill upstream to its confluence with the Lot River downstream. The aim of the study is to determine the origins of the surface waters using their chemical and stable isotopic compositions (¹⁸O, D and ¹³C), to better understand their circulation within the drainage basin and to assess the anthropogenic influences. The Garonne displays a specific ¹⁸O seasonal effect, and keeps its Pyrénean characteristics until its confluence with the Tarn River. The difference in the dissolved inorganic carbon (DIC) comes mainly from the change in lithology between the Pyrénées and the Massif Central mountains. Agriculture activity is only detected in the small tributaries. Copyright © 2009 John Wiley & Sons, Ltd.     

Scalarization of vector optimization problems

In this paper, we investigate the scalar representation of vector optimization problems in close connection with monotonic functions. We show that it is possible to construct linear, convex, and quasiconvex representations for linear, convex, and quasiconvex vector problems, respectively. Moreover, for finding all the optimal solutions of a vector problem, it suffices to solve certain scalar representations only. The question of the continuous dependence of the solution set upon the initial vector problems and monotonic functions is also discussed.The author is grateful to the two referees for many valuable comments and suggestions which led to major imporvements of the paper.