Search results for "carbon"

Morfologia e proprietà di sistemi nanocompositi poliammide/CNTs e poliammide/carbon black sottoposti a stiro elongazionale

2011

Experimental Investigation on Stiffness and Strength of Single-Lap Z-Pinned Joints in a Laminated CFRP Stress-Ribbon Strip

2016

Carbon fiber-reinforced polymer (carbon-polymer) is an advanced lightweight composite material with high strength and excellent resistance to corrosion and fatigue. Over the past decades, application of fiber-reinforced polymers has been spread from the aerospace to other branches of industry such as automobile and civil engineering. Unidirectional carbon-polymers have a high potential for replacing steel in tensile members. Recently, the first carbonpolymer stress-ribbon bridge has been constructed in Germany. The non-laminated strip-loop carbon-polymer thin strips were used as the load bearing components in this bridge. In comparison with the laminated components, the applied cables are c…

Titanocene Selenide Sulfides Revisited: Formation, Stabilities, and NMR Spectroscopic Properties

2019

[TiCp2S5] (phase A), [TiCp2Se5] (phase F), and five solid solutions of mixed titanocene selenide sulfides [TiCp2SexS5−x] (Cp = C5H5−) with the initial Se:S ranging from 1:4 to 4:1 (phases B–E) were prepared by reduction of elemental sulfur or selenium or their mixtures by lithium triethylhydridoborate in thf followed by the treatment with titanocene dichloride [TiCp2Cl2]. Their 77Se and 13C NMR spectra were recorded from the CS2 solution. The definite assignment of the 77Se NMR spectra was based on the PBE0/def2-TZVPP calculations of the 77Se chemical shifts and is supported by 13C NMR spectra of the samples. The following complexes in varying ratios were identified in the CS2 solutions of …

A one-pot method to enhance dissolution rate of low solubility drug molecules using dispersion polymerization in supercritical carbon dioxide

2009

Preparation of pH sensitive poly(vinilydenefluoride) porous membranes by grafting of acrylic acid assisted by supercritical carbon dioxide

2010

Aim of this work is to study the preparation of pH sensitive membranes for biomedical applications via thermal induced graft polymerization of acrylic acid (AA) on poly(vinilydenefluoride) (PVDF) assisted by supercritical carbon dioxide (scCO2). Using scCO2 as a solvent and swelling agent, the monomer and initiator (benzoyl peroxide) could diffuse faster and distribute more uniformly into the polymer matrix. A better control of the final molecular architecture should be achieved because bimolecular grafting reactions are accelerated with respect to chain degradation processes. Commercial hydrophobic PVDF porous matrixes were selected as model membranes. Grafted polymers were characterized b…

Melt phase ring opening polymrization of lactide and glycolide assisted by supercritical carbon dioxide

2010

Supercritical carbon dioxide induces sterilization of PLLA scaffolds contaminated by E. coli.

2014

The common sterilization techniques are based on physical processes that involve, for example, the use of autoclaves or systems to radiation such as γ-rays that can cause a structural change of the polymer treated. Therefore, the use of supercritical carbon dioxide (scCO2) is an excellent alternative, as it does not induce any variation of biomaterials treated (Perrut M., 2012). It's a good candidate because is readily available at low cost, non-toxic and non-flammable, it has an easily accessible critical point (7.38 MPa and 304.2 K) and excellent transport properties and wettability (White A. et al., 2005). We report the development of a supercritical CO2 based process capable of steriliz…

Modeling Heterogeneous copolymerization in scCO2

2008

Réponses du d13C au forçage astronomique dans divers contextes de production carbonatée : le cas du Valanginien du Sud-Est de la France

2018

International audience; Le d13C est un outil fréquemment utilisé pour établir des échelles de temps astronomiques en milieu (hémi-) pélagique. Pourtant le lien entre d13C et forçage astronomique n’est pas toujours clair, tant les sources de carbone sont multiples. Nous avons comparé le d13C à la susceptibilité magnétique (SM) et aux cortèges argileux dans les séries marno-calcaires du Valanginien du Bassin Vocontien (SE France). Ces deux signaux sont fréquemment utilisés pour détecter un forçage astronomique dans les alternances marno-calcaires. Deux intervalles de 400 ka (correspondant à un cycle de grande excentricité) ont été ciblés, l’un avant la crise des producteurs carbonatés associé…

Economical evaluation of ecological benefits of the demand side management

2014

Environmental pollution and over-exploitation of non-renewable sources to find energy are current topics for the modern world that is now at having to deal with several issues such as the greenhouse effect, acid rain and climate change. In this study, the economical estimate of the savings in carbon dioxide obtained with a careful management of electrical loads is presented. Four particular scenarios are designed as case studies: Italy, France, United Kingdom and Germany. A comparison is presented with a similar study, made in 2007, when green energies were not yet very developed.