86 research outputs found
Lignin as Sustainable Antimicrobial Fillers to Develop PET Multifilaments by Melting Process
Nowadays, textiles functionalization is developing increasingly, fabrics are not only defined by the intrinsic properties of the fiber but some properties are also brought to provide them added value. Among the desired properties, antibacterial activity is targeted to improve the comfort and durability of textiles but many commercial products use chemical substances which are harmful for the environment (regulation 528/2012). The goal of this study was to use bio-based biocide which can be incorporated in the polyethylene terephthalate (PET) by melt spinning for the development of functional PET. This biocide had to resist to the PET processing temperature up to 264°C which was the maximum temperature of implementation. Two kinds of Kraft lignin and titanium dioxide as reference were added by melting way. The antimicrobial activity was characterized at low concentration (1 and 2 wt.%), to avoid a significant decrease in mechanical strength for the multifilaments and to maintain optimal rheological properties of the polymer for the melt spinning process. Filled PET pellets were obtained by twin screw extrusion step and the multifilaments by melt spinning step. Finally, knitting structures were developed for the evaluation of the antibacterial activity. The mechanical (tensile test) and thermal (DSC and TGA) properties of the filaments were characterized
Insole customized Part 2: 2D/3D graphical process
Potrebe u području ortopedskih uložaka postaju sve važnije. Medicinska svrha ovih plantarnih proteza često je ispravljanje držanja ili biomehaničke neravnoteže koji imaju tendenciju da uzrokuju bol u raznim dijelovima tijela, ovisno o patologiji pacijenta. To se događa zbog povećanja broja ljudi s visokim tlakom ili onih koji imaju problema s dijabetesom ili drugim bolestima. No, cijena tih proizvoda može varirati. Bez obzira za što je terapijski proizvod bio predviđen, ekonomski model nije prilagođen za socijalno osiguranje. Za poboljšanje kvalitete proizvoda potreban je nov kreativan proces. Ovaj rad je
nastavak prethodnih radova. Proces koji se koristio za otkrivanje antropometrijskih točaka na stopalu uključen je u proces izrade prilagođenih uložaka. Kombinacijom tehnike koja izdvaja otisak stopala, uz specifičan postupak koji koristi obris (siluetu) za stvaranje 2D oblika uloška i upotrebljava 3D oblik standardnog kalupa cipele stvorili smo 3D oblik uloška koji je prilagođen stopalu.The needs in the sector of orthopedic insoles are becoming more important. The medical purpose of these plantar prostheses is often to correct the posture or biomechanical imbalance that tends to cause pain in various areas of the body depending on the pathology of the patient. This is due to the progression of people who are increasingly obese or have problems with diabetes or other diseases. But, the cost of its products can vary from one to two or more depending on the quality of the product that requires adaptation by a manual process to the morphology of the foot. Whatever the therapeutic product envisaged, the economic model is no longer adapted to the needs of patients and the budgetary imperatives of social security. A new creative process is
needed and must incorporate digital tools to reduce these manufacturing costs while improving the quality of products. This study is the continuity of previous works. The process that was used to detect the anthropometric points of the foot was incorporated into a process of creating customized insoles. By combining the technique that extracts the outline encompassing the footprint, a specific process that uses this outline to create the 2D shape of the insole and the using of 3D shape of the standard shoe-last, we have created the 3D shape of the insole adjusted to foot
Insole customized Part 1: Non-contact Method of Anthropometric points Detection for Feet
Bez obzira na ciljeve studije, bilo da se radi o morfološkoj klasifikaciji stopala ili prilagođavanju proizvoda poput ortopedskih uložaka / potplata ili prikladne obuće za atipična stopala, neophodno je pronaći racionalnu metodu za otkrivanje antropometrijskih točaka i krivulja. Studije o objašnjenju antropometrije stopala su malobrojne, a u nekim slučajevima predstavljaju suprotnosti mjerenjima između ručnog postupka i postupka automatskog skeniranja. Također, naš cilj bio je upotrijebiti beskontaktnu metodu mjerenja da se otkriju antropometrijske točke na stopalu. U ovoj metodi se predlažu različite tehnike praćenja pomoću različitih podesivih ravnina. U 3D grafičkom procesu, morfološke krivulje su lokalizirane pomoću tih antropometrijskih točaka i omogućuju identifikaciju stopala tim mjerenjima. Ona su uspoređena s mjerenjima pomoću 3D skenera stopala da bi se metoda otkrivanja antropometrijskih točaka
mogla potvrditi i poboljšati metoda koju koriste ovi skeneri.Regardless of the objectives of the study, whether it is the morphological classification of the feet or the customization of products such as orthopedic insoles or appropriate footwear for atypical feet, it is the imperative to find a rational method for detecting the anthropometric points and curves. The studies explaining the anthropometry of the foot are very few and in some cases present contradictions in the measurements between the manual and automatic
scanning processes. In addition, our goal was to implement a non-contact measurement method to detect the anthropometric points of feet. This method proposes different tracking techniques using different adjustable planes. In a 3D graphical process, the morphological curves have been located with the help of these anthropometrics points and allowed the identification of the foot by their measurements. These measurements were compared with those obtained by a 3D foot scanner to validate the detection method of anthropometric points and improve it by employing these scanners
40S hnRNP particles are a novel class of nuclear biomolecular condensates.
Heterogenous nuclear ribonucleoproteins (hnRNPs) are abundant proteins implicated in various steps of RNA processing that assemble on nuclear RNA into larger complexes termed 40S hnRNP particles. Despite their initial discovery 55 years ago, our understanding of these intriguing macromolecular assemblies remains limited. Here, we report the biochemical purification of native 40S hnRNP particles and the determination of their complete protein composition by label-free quantitative mass spectrometry, identifying A-group and C-group hnRNPs as the major protein constituents. Isolated 40S hnRNP particles dissociate upon RNA digestion and can be reconstituted in vitro on defined RNAs in the presence of the individual protein components, demonstrating a scaffolding role for RNA in nucleating particle formation. Finally, we revealed their nanometer scale, condensate-like nature, promoted by intrinsically disordered regions of A-group hnRNPs. Collectively, we identify nuclear 40S hnRNP particles as novel dynamic biomolecular condensates
An upper limit to the photon fraction in cosmic rays above 10^19 eV from the Pierre Auger Observatory
An upper limit of 16% (at 95% c.l.) is derived for the photon fraction in cosmic rays with energies above 10^19 eV, based on observations of the depth of shower maximum performed with the hybrid detector of the Pierre Auger Observatory. This is the first such limit on photons obtained by observing the fluorescence light profile of air showers. This upper limit confirms and improves on previous results from the Haverah Park and AGASA surface arrays. Additional data recorded with the Auger surface detectors for a subset of the event sample, support the conclusion that a photon origin of the observed events is not favoured
The effect of the geomagnetic field on cosmic ray energy estimates and large scale anisotropy searches on data from the Pierre Auger Observatory
We present a comprehensive study of the influence of the geomagnetic field on
the energy estimation of extensive air showers with a zenith angle smaller than
, detected at the Pierre Auger Observatory. The geomagnetic field
induces an azimuthal modulation of the estimated energy of cosmic rays up to
the ~2% level at large zenith angles. We present a method to account for this
modulation of the reconstructed energy. We analyse the effect of the modulation
on large scale anisotropy searches in the arrival direction distributions of
cosmic rays. At a given energy, the geomagnetic effect is shown to induce a
pseudo-dipolar pattern at the percent level in the declination distribution
that needs to be accounted for.Comment: 20 pages, 14 figure
Développement et mise en oeuvre de structures textiles multifonctionnelles contenant des nanotubes de carbone (application aux capteurs chimiques pour la détection de solvants)
Ce travail s inscrit dans le cadre du projet européen Inteltex dont l objectif est l élaboration de nouvelles structures textiles pour la détection de solvants. L utilisation de CPC (Composite Polymère Conducteur), composé d une matrice polymère isolante et de charges conductrices d électricité, permet de détecter la présence de solvant du polymère par son gonflement entraînant une déconnexion du réseau conducteur et une chute de la conductivité électrique. L utilisation de nanotubes de carbone (NTC) en tant que charge conductrice, permet d incorporer une faible quantité de charges pour une conductivité électrique recommandée pour la détection (10-3 S/m). Les matrices polymères, sensibles aux solvants et possédant un caractère filable, sont le polycarbonate (PC), le polylactide (PLA) et le polyéthylène téréphtalate (PET). Le seuil de percolation des NTC dans les monofilaments issus de l extrusion de 1,5 mm de diamètre est déterminé entre 1,5 et 2 % en masse. La transformation de ces composites en fil multifilamentaire par filage en voie fondue montre une chute de la conductivité des filaments avec l étirage. Un filament de PLA contenant au moins 4 % de NTC et de diamètre minimal de 80 m permet de conserver les propriétés électriques. Le filage de cette fibre nécessite l introduction d un plastifiant afin d améliorer la filabilité du mélange. Les propriétés électriques, thermiques, mécaniques, morphologiques et la fluidité des filaments sont étudiées en fonction du procédé de transformation et de leur composition. Des filaments proches du seuil de percolation et incorporés dans une structure tissée, montrent une sensibilité à l humidité, à l éthanol et au toluène.This work is performed through the European project Inteltex. The aim is to develop new textile structures for the solvent detection. The use of CPC (Conductive Polymer Composite) composed of an insulating polymer matrix and conductive fillers, allows to detect the solvent presence by the swelling of the polymer that induces the conductive network deconnexion and the decrease of the electrical conductivity. The use of carbon nanotubes (CNT) as conductive fillers is a biggest advantage because only a low content is necessary to achieve the appropriate electrical conductivity for sensing (10-3 S/m). The different sensitive and spinnable matrices are polycarbonate (PC), polylactide (PLA) and polyethylene terephthalate (PET). The percolation threshold of CNT in 1.5 mm diameter monofilament, produced by extrusion, is determined between 1.5 and 2 wt.% of CNT. The elaboration of multifilament yarns by melt spinning process show a decrease of the conductivity with the drawing effect. In order to maintain the electrical properties, PLA fibers containing at least 4 % of CNT and having a minimum diameter of 80 m have to be produced. In this way it is necessary to introduce a plasticizer to improve the composites spinnability. The electrical, thermal, mechanical, morphological properties and fluidity of filaments were studied depending on the processing conditions and their composition. Composite fibers, close the percolation threshold, show sensitivity to humidity, ethanol and toluene.LILLE1-Bib. Electronique (590099901) / SudocSudocFranceF
The Influence of 1-Butanol and Trisodium Citrate Ion on Morphology and Chemical Properties of Chitosan-Based Microcapsules during Rigidification by Alkali Treatment
Linseed oil which has various biomedical applications was encapsulated by chitosan (Chi)-based microcapsules in the development of a suitable carrier. Oil droplets formed in oil-in-water emulsion using sodium dodecyl sulfate (SDS) as emulsifier was stabilized by Chi, and microcapsules with multilayers were formed by alternate additions of SDS and Chi solutions in an emulsion through electrostatic interaction. No chemical cross-linker was used in the study and the multilayer shell membrane was formed by ionic gelation using Chi and SDS. The rigidification of the shell membrane of microcapsules was achieved by alkali treatment in the presence of a small amount of 1-butanol to reduce aggregation. A trisodium citrate solution was used to stabilize the charge of microcapsules by ionic cross-linking. Effects of butanol during alkali treatment and citrate in post alkali treatment were monitored in terms of morphology and the chemical properties of microcapsules. Various characterization techniques revealed that the aggregation was decreased and surface roughness was increased with layer formation
Étude de l'adhésion de latex sur des fibres dans les non-tissés liés par voie chimique
Dans le domaine des matériaux composites, quelle que soit la nature de leurs constituants, l'adhésion fibre-matrice joue un rôle de la plus haute importance. Ce travail a pour objet l'étude de l'adhésion entre des fibres polymères et des systèmes élastomères à bases de latex. L'objectif est d'améliorer l'interaction entre les fibres de polyester et la matrice élastomère constituée d'un mélange ded latex acrylique et de latex NBR. Les fibres industrielles de polyester utilisées sont désensimées ou ensimées, traitées avec un sel ou des groupements réactifs... Deux types de test d'adhésion ont été utilisés : le test pull out et la méthode de fragmentation sur composite monofilamentaire. Un test micromécanique utilisant le DMA (Dynamic Mechanical Analyser) a été développé, afin de caractériser l'adhésion entre les différents matériaux. Une caractérisation thermodynamique, réalisée par une étude de mouillage, sur les films de latex et sur les fibres en fonction du type d'ensimage a permis de déterminer les composantes polaires et apolaires des différents matériaux. Une étude topographique par microscopie à force atomique permet d'observer l'influence de la nature de l'ensimage sur l'état de surface et de la rugosité des fibres. Des mesures de potentiel zéta sont réalisées, sur les solutions colloïdales de latex et sur les fibres PET désensimées et traitées avec un sel divalent. Nous corrélons ces différents résultats obtenus avec ceux du test de pull out. Enfin, une approche de la morphologie d'un mélange de latex chargé en fibres est proposée par des mesures DSC sur ces composites et par la détermination des coefficients d'étalement des latex sur les fibres. De façon générale, il peut être intéressant de mélanger des polymères incompatibles, afin d'améliorer certaines propriétés mécaniques pour un coût moins élevé. Le phénomène de démixtion des deux latex a permis d'améliorer l'adhésion fibre/matrice grâce ...LILLE1-BU (590092102) / SudocTOULOUSE-ENSIACET (315552325) / SudocSudocFranceF
The Influence of 1-Butanol and Trisodium Citrate Ion on Morphology and Chemical Properties of Chitosan-Based Microcapsules during Rigidification by Alkali Treatment
Linseed oil which has various biomedical applications was encapsulated by chitosan (Chi)-based microcapsules in the development of a suitable carrier. Oil droplets formed in oil-in-water emulsion using sodium dodecyl sulfate (SDS) as emulsifier was stabilized by Chi, and microcapsules with multilayers were formed by alternate additions of SDS and Chi solutions in an emulsion through electrostatic interaction. No chemical cross-linker was used in the study and the multilayer shell membrane was formed by ionic gelation using Chi and SDS. The rigidification of the shell membrane of microcapsules was achieved by alkali treatment in the presence of a small amount of 1-butanol to reduce aggregation. A trisodium citrate solution was used to stabilize the charge of microcapsules by ionic cross-linking. Effects of butanol during alkali treatment and citrate in post alkali treatment were monitored in terms of morphology and the chemical properties of microcapsules. Various characterization techniques revealed that the aggregation was decreased and surface roughness was increased with layer formation
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