Search results for "RICH"

The rate of polymerization in two loci reaction systems: VDF-HFP precipitation copolymerization in supercritical carbon dioxide

2011

When the copolymerization of vinylidene fluoride (VDF) and hexafluoropropylene (HFP) is carried out in supercritical carbon dioxide (scCO 2) under heterogeneous conditions, the reaction occurs both in the continuous CO 2-rich phase and in the dispersed polymer-rich phase. The two phases being characterized by different values of reactant concentrations and kinetic parameters, one would expect that the reaction kinetics is affected by the polymer phase holdup in the reactor. However, the reaction rate is almost insensitive to the amount of produced polymer, at least at specific reaction conditions. This apparent contradiction is discussed and clarified in this paper by a series of comparativ…

Memory effects in MOS capacitors with silicon quantum dots

2001

To form crystalline Si dots embedded in SiO2, we have deposited thin films of silicon-rich oxide (SRO) by plasma-enhanced chemical vapor deposition of SiH4 and O2. Then the materials have been annealed in N2 ambient at temperatures between 950°C and 1100°C. Under such processing, the supersaturation of Si in the amorphous SRO film produces the formation of crystalline Si dots embedded in SiO2. The narrow dot size distributions, analyzed by transmission electron microscopy, are characterized by average grain radii and standard deviations down to about 1 nm. The memory functions of such structures has been investigated in MOS capacitors with a SRO film sandwiched between two thin SiO2 layers …

Solid-state electrochemical characterization of emissions and authorities producing Roman brass coins

2020

[EN] The voltammetry of immobilized particles (VIMP) is applied to describe the solid state electrochemistry of brass. This methodology, which involves sampling at the nanogram level, is applied to discriminate mints/authorities producing different Roman monetary emissions covering since the Republic (88 BCE) to Domitianus (55-96 CE) Upon attachment to graphite electrodes in contact with aqueous acetate buffer at pH 4.75, well defined voltarnmetric responses were obtained centered on Cu- and Zn-localized signals whose intensity can be correlated to EMP data, being sensitive to the contents of Zn (15-30 wt.%) and Sn (0.01-1.1 wt.%). Voltammetric data, combined with ATR-FTIR and FIB-PESEM/EDS…

Antimicrobial Properties of the Modified Cotton Textiles by the Sol-Gel Technology

2015

Comparison of the antimicrobial properties of textiles with amorphous coatings containing Zn and Si obtained by the sol-gel technology against microorganismsPseudomonas fluorescens,Saccharomyces cerevisae,Trichoderma viridethat can cause cotton textile destruction was made. Modified textile were evaluated using scanning electron microscopy, energy dispersive x-ray spectroscopy. Investigation of antimicrobial properties of the cotton fabric samples treated with different zinc acetate dihydrate concentration sols and various thermal post-treatments was made. Strong inhibition of microbial growth was detected for all cotton textile samples treated via sol-gel method according all tests microor…

Optical Sensor for Real-Time Detection of Trichlorofluoromethane

2019

Trichlorofluoromethane was once a promising and versatile applicable chlorofluorocarbon. Unaware of its ozone-depleting character, for a long time it was globally applied as propellant and refrigerant and thus led to significant thinning of the ozone layer and contributed to the formation of the so-called ozone hole. Although production and application of this substance were gradually reduced at an early stage, we still face the consequences of its former careless use. Today, trichlorofluoromethane is released during recycling processes of waste cooling devices, traded on the black market, and according to recent findings still illegally manufactured. Here, we present an optical sensor devi…

Regenerable ZnO/GaAs Bulk Acoustic Wave Biosensor for Detection of Escherichia coli in “Complex” Biological Medium

2021

A regenerable bulk acoustic wave (BAW) biosensor is developed for the rapid, label-free and selective detection of Escherichia coli in liquid media. The geometry of the biosensor consists of a GaAs membrane coated with a thin film of piezoelectric ZnO on its top surface. A pair of electrodes deposited on the ZnO film allows the generation of BAWs by lateral field excitation. The back surface of the membrane is functionalized with alkanethiol self-assembled monolayers and antibodies against E. coli. The antibody immobilization was investigated as a function of the concentration of antibody suspensions, their pH and incubation time, designed to optimize the immunocapture of bacteria. The perf…

Bacteria survival and growth in multi-layered silica thin films

2012

International audience; The fields of application of sol–gel encapsulation technology for living cells have been greatly extended over the last few years. Photobioreactors,1 biofuel cells,2 bio-remediation materials,3 biosensors4 and biomedical devices5 are currently being developed taking advantage of the robustness of inorganic materials compared to their (bio)-organic counterparts. In many of these applications, the formation of stable thin films (<1 μm) would be highly desirable for integration, for instance, in bio-chips.6 However, several limitations exist when trying to transfer a protocol mainly developed from bulk hydrogels to thin films. Especially, the storage stability becomes m…

Regularization and finite element approximation of the wave equation with Dirichlet boundary data

1990

Error Estimates of Uzawa Iteration Method for a Class of Bingham Fluids

2015

The paper is concerned with fully guaranteed and computable bounds of errors generated by Uzawa type methods for variational problems in the theory of visco-plastic fluids. The respective estimates have two forms. The first form contains global constants (such as the constant in the Friedrichs inequality for the respective domain), and the second one is based upon decomposition of the domain into a collection of subdomains and uses local constants associated with subdomains.

Incremental heuristic approach for meter placement in radial distribution systems

2019

The evolution of modern power distribution systems into smart grids requires the development of dedicated state estimation (SE) algorithms for real-time identification of the overall system state variables. This paper proposes a strategy to evaluate the minimum number and best position of power injection meters in radial distribution systems for SE purposes. Measurement points are identified with the aim of reducing uncertainty in branch power flow estimations. An incremental heuristic meter placement (IHMP) approach is proposed to select the locations and total number of power measurements. The meter placement procedure was implemented for a backward/forward load flow algorithm proposed by…