Search results for " Plastic"

Conducting Polymer with Orthogonal Catechol and Disulfide Anchor Groups for the Assembly of Inorganic Nanostructures

2017

To combine several inorganic components with organic material in a controlled special and permanent manner still remains a difficult issue. Two specifically functionalized block copolymers were synthesized separately and combined in a second step. A heterofunctional poly(ethylene glycol) (PEG) block copolymer bearing a single amino unit, a short PEG spacer, and multiple catechol functionalities was obtained via anionic ring-opening polymerization (AROP). Using the reversible addition–fragmentation chain transfer (RAFT) radical polymerization technique, a semiconducting block copolymer with carbazole side groups was obtained. The second polyacrylate block contained reactive ester groups and …

Oligothiophenes for Pattern Formation by Stamping

2003

Oligothiophene monomers with a fixed length varying from 3 to 5 thiophene rings were prepared by Stille coupling. They were functionalised with one or two methacrylate groups to allow polymerization and cross-linking. These monomers can be patterned with the help of soft silicon stamps (e.g., with the micro-injection moulding in capillaries process) on substrates like glass or flexible polymer foils. If a photoinitiator has been added, they can then be hardened by exposure to UV-light through the transparent stamp. Afterwards the stamp can be removed. This allows the preparation of several centimeters long oligothiophene lines of a width varying between 50 and 0.5 μm. These lines of semicon…

Solid state NMR investigation of the roman Acqualadroni rostrum: tenth year assessment of the consolidation treatment of the wooden part

2020

Abstract: This work follows a previous one dealing with the state of conservation study of the wooden part of the roman Acqualadroni rostrum soon after its finding in the seabed of Acqualadroni (Messina, Italy). The archaeological survey and recovery were particularly relevant since this artefact is one of the two rostrums, nowadays known,found together with its wooden part. Following the recovery, it was consolidated by immersion in a melamine-formaldehyde resin (Kauramin) aqueous solution for eight months at the “Centro di Restauro del Legno Bagnato” (Pisa, Italy). The present investigation is aimed to determine at microscopic scale the wood state of conservation and to highlight interact…

Stress-Strain Law for Confined Concrete with Hardening or Softening Behavior

2013

This paper provides a new general stress-strain law for concrete confined by steel, fiber reinforced polymer (FRP), or fiber reinforced cementitious matrix (FRCM), obtained by a suitable modification of the well-known Sargin’s curve for steel confined concrete. The proposed law is able to reproduce stress-strain curve of any shape, having both hardening or softening behavior, by using a single closed-form simple algebraic expression with constant coefficients. The coefficients are defined on the basis of the stress and the tangent modulus of the confined concrete in three characteristic points of the curve, thus being related to physical meaningful parameters. It will be shown that if the v…

1996

The uses of atomic force microscopy, scanning tunneling microscopy, electron spectroscopic imaging, electron energy loss spectroscopy and low voltage, high resolution scanning electron microscopy in polymer research are reviewed

Multidentate Tetrahydrofurfuryloxide Ligand in a Ziegler−Natta Catalyst Studied by Molecular Modeling

2008

The transition from a generation III Ziegler-Natta catalyst with a monodentate Lewis base to a more modem generation 1V/V system, containing a tetrahydrofuran derivative, the tetrahydrofurturyloxide C 4 H 7 O-CH 2 O - bidentate ligand (THFFO), was studied by means of molecular modeling and DFT calculations. This particular ligand was carefully chosen so that it remained in the titanium coordination sphere in the model active site. With such a constraint, the dual role of tetrahydrofurfuryloxide was identified: it was demonstrated how the presence of this ligand limits the number of isomeric active sites as well as enhances the selectivity of the species that can still exist. The results ind…

Indicaxanthin is able to modulate human motor cortical excitability and plasticity

Plastic and cosmetic surgery of the male breast

2020

The thorax has a fundamental role in the aesthetic of the male body: Congenital or acquired alterations are experienced as extremely frustrating clinical situations. Most breast surgery texts briefly mention gynecomastia, but no text comprehensively addresses the male breast and thorax, including reconstructive and cosmetic surgery and surgery in transgender patients. This gap is now thoroughly filled by Plastic and Cosmetic Surgery of the Male Breast: After introducing principles of anatomy and aesthetics for the male thorax, the first part focusses on the main congenital malformations and their treatment; the main benign acquired pathologies and their treatment (including an ample section…

Reliability Estimation of Optimal Viscoelastic Composite Shells in Critical-Time Calculations

2003

The problem of reliability estimation for optimal viscoelastic composite shells in critical-time calculations is considered. The weight minimization of a viscoelastic composite shell, with constraints on deflections at the critical time, leads to a system deforming unstably, whose deflections grow in time with an increasing rate. A method for estimating the reliability of such shells in calculating the critical time is discussed. This time is regarded as a random variable depending on many, roughly equivalent, factors. An analysis of the reliability is carried out for different values of coefficients of variation, occurring in practice.

Analysis of Early Host Responses for Asymptomatic Disease Detection and Management of Specialty Crops

2010

The rapid and unabated spread of vector-borne diseases within US specialty crops threatens our agriculture, our economy, and the livelihood of growers and farm workers. Early detection of vector-borne pathogens is an essential step for the accurate surveillance and management of vector-borne diseases of specialty crops. Currently, we lack the tools that would detect the infectious agent at early (primary) stages of infection with a high degree of sensitivity and specificity. In this paper, we outline a strategy for developing an integrated suite of platform technologies to enable rapid, early disease detection and diagnosis of huanglongbing (HLB), the most destructive citrus disease. The re…