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The radiosterilization of plastic packaging theoretically induces two types of chemical modifications, namely reticulation and cleavage, that depend not only on the chemical structure of the polymer, but also on the kind and dose of radiation. This article proposes a methodology for studying plasticized polyvinylchloride (PVC) behavior submitted to β radiation. Analytical techniques such as thermogravimetric analysis (TGA) and size exclusion chromatography (SEC) coupled with a light scattering detector were used in this study. SEC has informed us directly on the modifications (reticulation, scission) that intervened after a radiotreatment; TGA allowed us to highlight polymer structural changes. In addition, FTIR was employed to demonstrate an intermolecular dehydrochlorination following the radiotreatment. The results of these investigations permitted us to demonstrate both a reticulation and a scission phenomena within the PVC polymer. © 1994 John Wiley & Sons, Inc.

After a short review of the different physical methods of determination of the HLB (lipophilic/hydrophilic balance) value of surface-active agents, two techniques were investigated and experiments were performed on a large number of commercial surface-active agents: H-NMR which computes HLB with the help of the integration of the H-signals from the lipophilic and hydrophilic parts of the molecule and by dielectric constant measurement which computes the HLB from knowledge of the polarity of molecules under the influence of an electrical field. The results are described and discussed.

Synopsis The purpose of this work was to compare the evolution of three multiple emulsions (ME) by different controls. The series of water-in-oil-in-water (W/O/W) multiple emulsions were elaborated and controlled by both the usual analyses which permitted the classification of the multiple emulsions with respect to their thermal stability, and the rheological oscillatory and flow analyses which are polyvalent methods. Further, these allow the ‘identity card’ of the multiple emulsion to be drawn, its evolution to be followed, and moreover, its behaviour being foreseen by simulating ageing by shear. Three different behaviours are observed; a destructuration, a phase inversion and stability. Resume L'objectif de ce travail est de comparer, a l'aide de differentes analyses, l'evolution de trois emulsions multiples H/L/H. Ces emulsions sont controlees par des analyses classiques qui permettent de classer les emulsions en fonction de leur stabilite thermique, et des analyses rheologiques en dynamique et en ecoulement qui permettent de dresser la ‘carte d'identite’ de l'emulsion multiple, de suivre son evolution et enfin de prevoir son comportement apres simulation du vieillissement par le cisaillement. Trois comportements sont observes; une destructuration, une inversion de phase et une stabilite.

Synopsis The main purpose of this article is to define multiple emulsions, their preparation (new materials and manufacturing processes) methods of characterisation and analysis, and their applications in cosmetology and pharmacy. The second part is devoted to a presentation of the investigation in our laboratory into the optimal manufacturing process to provide stable formulations. The study of release mechanisms from such formulations mainly shows a breakdown of multiple droplets which could be controlled by variation of solute concentration.

Synopsis The main purpose of this article is to define multiple emulsions, their preparation (new materials and manufacturing processes) methods of characterisation and analysis, and their applications in cosmetology and pharmacy. The second part is devoted to a presentation of the investigation in our laboratory into the optimal manufacturing process to provide stable formulations. The study of release mechanisms from such formulations mainly shows a breakdown of multiple droplets which could be controlled by variation of solute concentration. Resume Le principal objectif de cet article a consiste, dans une premiere partie, a effectuer une presentation generale des emulsions multiples, tant sur le plan de la definition, de l'obtention (matieres premieres, mode de fabrication) que des methodes de caracterisation et d'analyse et, enfin des differentes applications dans les domaines cosmetique et pharmaceutique. La seconde partie est consacree a la presentation des travaux effectues dans notre laboratoire et concerne la mise au point d'une procedure de fabrication optimale et la realisation de formulations stables. l'etude des mecanismes de liberation a partir de telles formulations est presentee. Il est possible d'envisager la realisation de systemes a liberation controlee qui s'effectuerait par eclatement des globules et qui serait modulee en faisant varier le gradient de concentration des especes dissoutes.

Assembly counts for a significant portion of the total cost of electronics devices. It is particularly true for optoelectronics devices as the majority of the assembly and packaging operations are still carried out manually. Cost reduction, linked to the integration of a larger number of elements into a single component is a preliminary condition to the deployment of optical networks in the telecommunications. Automation of the assembly improves processes reproducibility, increases yield and throughput and contributes to better control of the manufacturing cost. Planar technology is identified as a key enabling element of assembly automation. The integration of the optical components onto a silicon bench requires the use of a device bonder with flip chip capability and sub-micron placement accuracy. A particularity of the optoelectronics devices assembly is the need for using different processes for the various components being assembled with the same device. Bonding techniques such as thermo-compression, flux-less reflow and adhesive joining, together with very tight placement tolerance must be combined in a single assembly sequence. The paper describes the fully automatic assembly of an optical demonstrators consisting of a silicon bench on which are assembled various components: edge-emitting laser diode, photodiode, thermistance and cylindrical lens. A process mix is necessary: general reflow with self-alignment capability, in situ reflow and adhesive joining with 0.5/spl mu/m passive alignment accuracy. The assembly process is explained and the positive impact of high accuracy placement on the product performance is discussed. Furthermore, the use of the same platform and its high resolution stages (10nm) to perform active alignment by optimizing the signal output of a powered device is described.

We present the characteristics of an uncooled plastic module for outdoor operation (+3 dBm at 85/spl deg/C). A transmission experiment is reported at 622 Mbit/s and up to 85/spl deg/C temperature. We describe the module design, then we discuss the performance of the optoelectronic (OE) chips. Finally, the static and dynamic performance of the intermediate sub-assembly and of the whole 1.3 /spl mu/m CW plastic module are reported.

Summary form only given. This paper reports 1.3-/spl mu/m laser passively aligned with a cleaved single-mode fiber and encapsulated with silicone rubber on a Si substrate. Under 70-mA DC operation at 85/spl deg/C, a fiber power >2 mW is obtained for several assemblies. This result is thought to be the highest value reported so far for such type of device. It shows that these advanced technologies are promising for long-haul transmission.

A low cost integration technology has been developed to assemble 2.5 and 10 Gb/s photodiodes. It relies on flip-chipped devices with lensed fibres positioned in V-grooves. For 2.5 Gb/s the photodiode, the fibre and the transimpedance amplifier are integrated on a single Si motherboard compatible with mounting in a mini-dil module. The sensitivity is -23.5 dBm at 10/sup -10/ BER with no error floor.

We report here, to our knowledge, on the first demonstration of a modular 8/spl times/8 optical switch built with opto-hybrid 8/spl times/1 SOA-based space switch modules. A WDM experiment shows that this 8 x 8 optical switch offers a potential of 1.28 Tbit/s throughput.

A passive assembly process for laser modules has been developed that is based on silicon submounts with 3-dimensional structures and corresponding laser chips. It makes use of surface tension effects to pull the chips into their final position defined by mechanical stops and stand-offs. Full singlemode compatible accuracy is achieved. A prefabricated plastic housing with an integrated optical connector completes the concept. Due to the eliminated fixed fiber pigtail and the materials that are used all elements are compatible with automated surface mounting (SMT) into the system electronics. All these details contribute to the low cost technology for high performance laser modules. Although active cooling is not provided laser modules are capable of 2.5 mW emission for environmental temperatures as high as 85/spl deg/C. The concept is open for other applications like receivers and more complex integrated devices.

We report here, for the first time to our knowledge, on operation of 1x4 opto-hybrid space switch based on an array of 4 Gain-Clamped SOA (CG-SOA) gates. A loss-free 1x4 operation has been demonstrated over all paths for a 80mA injected current. This device is WDM compatible and operates up to 10 Gbit/s.

Nitration of styryl ketones with nitrogen peroxide leads to the corresponding α-nitroethylenic ketones in good yield. However, the presence of methoxy groups involves a nitration on the aromatic nucleus.LiAlH4 reduction of α-nitrostyrylketones yields the corresponding racemic erythro- and threo-aminoalcohols; after acylation and cyclisation a dihydro-quinoline or a 2-oxazoline is obtained.Electrochemical reduction of these nitrostyryl-ketones selectively provides the α-ketoximes, which are themselves reduced electrolytically to α-aminoketones. These latter compounds dimerise in neutral medium to dihydro-2,5-pyrazines which aromatise to the corresponding pyrazines. In acid medium an α-ketol is obtained.A mechanism for the reduction is proposed implicating an enaminol intermediate.

Le dihydro-1,2 oxo-1 triazino-1,2,4-[4,5-b] indazole et ses derives sont accessibles par transposition de l'[(oxadiazolyl-1,3,4)-2]-3 indazole ou par cyclisation d'ethoxymethylidene hydrazides indazoliques. La synthese du dioxo-1,4 tetrahydro-1,2,3,4 triazino-1,2,4-[4,5-b] indazole est realisable par cyclisation du N-carbethoxyhydrazide du carboxy-3 indazole et celle du dihydro-3,4 oxo-4 triazino-1,2,4-[4,5-b] indazole par cyclisation de la N-carbethoxy hydrazone du formyl-3 indazole. Le triazino-1,2,4- [4,5-b] indazole est accessible par l'intermediaire du dihydro-1,2 thioxo-1 triazino-1,2,4-[4,5-b] indazole. Les spectres de rmn 1H sont etudies. 1,2,4-Triazino[4,5-b]indazol-1(2H)one and its derivatives were prepared by transposition of 3-[2-(-1,3,4-oxadiazolyl)]indazole or by ring closure of indazole ethoxymethylidenehydrazides. The synthesis of 1,2,3,4-tetrahydro-l,2,4-triazino[4,5-b]indazole-1,4-dione was achieved by cyclising the N-carbethoxyhydrazide of indazole-3-carboxylic acid and the synthesis of 1,2,4-triazino-[4,5-b]indazol-4(3H)one was made by cyclising the N-carbethoxy-hydrazone of indazole-3-carboxaldehyde. The Oxydation of 1,2,4-triazino[4,5-b]indazole-l(2H)thione gave 1,2,4-triazino-[4,5-b]indazoles. Nmr spectral data are reported.

The 13 C NMR spectra of some iridoids of known structure are analysed. The data obtained have been applied to the determination of structure of feretoside and the identification of gardenoside, both isolated from the stem bark of Feretia apodanthera .

Les (propynyl-2)-1 aminomethyl-2 benzimidazoles, prepares a partir d'orthodiamines aromatiques, peuvent etre transformes avec de bons rendements en pyrido[1,2-a]benzimidazoles. Le premier temps de la reaction est une heterocyclisation: les intermediaires ont ete isoles et leur rearrangement etudie. La methode est applicable a certains azabenzimidazoles. The Cyclisation of 1-(2-propynyl)2-aminomethylbenzimidazoles leads to pyrido[1,2-a]benzimidazoles. The proposed mehcanism involves in a first step hetrocyckisation followed by a rerrangemnet. This Process is suitable for some aza analoga of benzimidazole.

La synthese de la 3H (indazolyl-3′)-5 oxadiazol-1,3,4 one-2 (2) est effectuee par cyclisation de l'hydrazide de l'acide indazole-3 carboxylique (3) avec l'oxychlorure de carbone. La determination de la structure est realisee grâce a une etude comparative par rmn du 13C et par spectrometrie de masse avec la 2H, 3H-triazino-1,2,4-[4,5-b]indazoledione-1,4 (1). Un rearrangement en 2 precede la fragmentation de 1 sous l'impact electronique. The 3H-5-(3′-indazolyl)-1,3,4-oxadiazol-2-one was obtained by cyclising the hydrazide of the 3-indazolecarboxylic acid with carbonyl chloride. The structure was assigned by 13C nmr and mass spectrometry comparing the 2H, 3H-triazino-1,2,3[4,5-b]indazoledione-1,4. Rearrangement into 3H-5-(3′-indazolyl)-1,3,4-oxadiazol-2-one precedes the fragmentation of 2H,3H-triazino-1,2,4-[4,5-b]indazoledione-1,4 upon electron-impact.

The main nmr parameters of 1,2,4-triazino[4,5-b]indazole derivatives were measured on the basis of their 13C nmr spectral analysis compared to indazole models. 1J C-H coupling constants were studied and the correct structure of 1,2,4-triazino[4,5-b]indazoles was elucidated.

Resume Cette etude met en evidence la structure du derive obtenu par l'action de l'acide ascorbique sur les amines primaires et les acides α amines; les methodes utilisees sont la resonance magnetique nucleaire du 13C, et la spectrophotometrie infra-rouge. La configuration chimique est comparable a celle du pourpre de Ruhemann obtenu par l'action de la ninhydrine sur les acides α amines.

This study outlines the structure of the by-product obtained by the action of ascorbic acid on primary amines and alpha-amino-acids; the methods used are (13)C, NMR and infrared spectrophotometry. The chemical form is comparable to that of Ruhemann purple, obtained by the action of ninhydrin on alpha-amino-acids.

A specific reverse-phase high-performance liquid chromatographic (HPLC) technique is described for the analysis of bile acids and their conjugates in human serum. Precise quantitation is obtained using UV detection. 13C-NMR spectrometry suggests a structural explanation for the different HPLC retention times of Chenodeoxycholic acid, its epimer (ursodeoxycholic acid), and their methyl esters.