Search results for "fiber"

Interactions between cationic amylose derivatives and a pulp fiber model surface studied by molecular modelling

2007

This study was performed in order to obtain more information about the interactions between pulp fibers and acetylated cationic starch derivatives on a molecular scale. The adsorption of the polymers on the fiber surface was studied by simulating polymers on a fiber model surface at 300 K. Fractional atomic coordinates of regenerated cellulose II were used to generate a cellulose fiber surface model. Carboxylate groups were added on the cellulose surface to represent the anionic charge of pulp fiber which originates from hemicelluloses. Amylose chains cationized and acetylated atom by atom were chosen to represent four different starch derivatives. Atomic charges used in simulations were ca…

1986

Preparation and mechanical characterization of fibres from a new copoly(ether-ester-amide) are reported. The mechanical characteristics are slightly lower than those of polyamide 6, but satisfactory for textile use, and the fibres have larger moisture absorption. This gives rise to more comfortable fibres preventing the accumulation of electrostatic charges. Die Herstellung und mechanische Charakterisierung von Fasern aus einem neuen Copoly(ether-ester-amid) werden beschrieben. Die mechanischen Eigenschaften sind etwas schlechter als die von Polyamid 6, aber ausreichend fur textile Anwendungen. Die Fasern weisen eine grosere Feuchtigkeitsabsorption auf. Dies fuhrt zu einem angenehmeren Verh…

3.5-μm bandwidth mid-infrared supercontinuum generation in a 2-cm long suspended-core chalcogenide fiber

2014

A supercontinuum source extending from 0.6 to 4.1 µm has been successfully generated in a 2-cm long As2S3 chalcogenide suspended-core fiber by means of a nJ-level 200-fs pumping at 2.5 µm.

Evaluation of the retinal nerve fiber layer thickness in smokers

2019

Synthesis of novel fluorinated building blocks via halofluorination and related reactions.

2020

A study exploring halofluorination and fluoroselenation of some cyclic olefins, such as diesters, imides, and lactams with varied functionalization patterns and different structural architectures is described. The synthetic methodologies were based on electrophilic activation through halonium ions of the ring olefin bonds, followed by nucleophilic fluorination with Deoxo-Fluor®. The fluorine-containing products thus obtained were subjected to elimination reactions, yielding various fluorine-containing small-molecular entities.

Optimized Continuous Application of Hyperpolarized Xenon to Liquids

2018

International audience; In recent years, NMR with hyperpolarized (HP) xenon inside functionalized host structures (e.g. cryptophanes) have become a potential candidate for the direct observation of metabolic processes (i.e. molecular imaging). A critical issue for real applications is the dissolution of the HP-gas in the liquid which contains the host. In this work, we present recent developments for an improved and controlled dissolution of HP-Xe in liquids using hollow fiber membranes and different compressor systems. The designed apparatus consists of a compressor and a membrane unit. The compressor provides HP-129 Xe continuously at small adjustable pressures and in a polarization-prese…

Effect of the color of the intraocular lens on optical and visual quality

2014

Purpose: To analyze the optical quality of intraocular lenses (IOL) with an orange (PC440Y) and a yellow (SN60AT) filter, and correlate these results with the visual quality of patients with these implants. Setting: Fisabio Oftalmología Médica, Valencia, Spain. Design: Randomized prospective study. Materials and Methods: The IOL optical quality was determined using the modulation transfer function (MTF) and the spectral transmission. The visual quality of 87 eyes with cataract (51 with orange filter and 36 with yellow filter) was determined by best corrected visual acuity (BCVA) and contrast sensitivity function (CSF) under photopic and mesopic conditions. To analyze the results, we use a S…

Nonlinear beam self-cleaning in a coupled cavity composite laser based on multimode fiber

2017

International audience; We study a coupled cavity laser configuration where a passively Q-switched Nd:YAG microchip laser is combined with an extended cavity, including a doped multimode fiber. For appropriate coupling levels with the extended cavity, we observed that beam self-cleaning was induced in the multimode fiber thanks to nonlinear modal coupling, leading to a quasi-single mode laser output. In the regime of beam self-cleaning, laser pulse duration was reduced from 525 to 225 ps. We also observed a Q-switched mode-locked operation, where spatial self-cleaning was accompanied by far-detuned nonlinear frequency conversion in the active multimode fiber.

Morphology and properties of compatibilized PP/PET melt spun fibers

2017

This work provides a study on the influence of a rubbery compatibilizer on the morphology and on the physical properties of polypropylene (PP)/polyethylenetherephthalate(PET) melt spun fibers at different hot draw ratios. In particular, a sample of SEBS copolymer grafted with maleic anhydride was used as compatibilizer. Both the uncompatibilized PP/PET blend and the compatibilized one were prepared by melt compounding in a counter-rotating twin-screw extruder. The materials have been characterized from a rheological, morphological and mechanical point of view. The addition of the compatibilizer increased the viscosity in shear flow of the uncompatibilized blend, and significantly improved t…

A New System for Choosing the Form and Size of Complete Denture Anterior Teeth

2016

Introduction: In the absence of pre-extraction records, the choice of the size an form of anterior complete denture teeth can be extremely subjective. Several clinical and statistical parameters are usually used for choosing the correct size and form of the complete denture anterior teeth. Clinical Innovation: The technique consists of a system that allows the dentist to choose and, if necessary, easily change the dental mold during maxillomandibular recording session. The unique feature of the system is that six teeth of each mold are represented by veneers, which are connected to each other on the lingual surface by a fiber that allows each veneer some degree of movement. Discussion: This…