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1

Relationship between porosity characteristics and concrete frost durability in bridges

Wawrzeńczyk J., Molendowska A., Kłak A.

Structure and Environment

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2012

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Vol. 4, no. 4

28--34

EN

Current requirements for concrete mix design for bridges, including the acceptable absorption value of nw ≤ 4% are being widely discussed. This paper presents the results of the research conducted on concrete with granite aggregate content. The research involved the analysis of relationshp between strength, absorption, permeability, porosity structure and the freeze-thaw resistance of air entrained and non-air entrained concretes with variable W/C ratios.

2

Estimation and measurements of resonance scattering on the gas filled polymer microspheres

Secomski W., Klimonda Z.

Hydroacoustics

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2009

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Vol. 12

201-208

EN

The gas filled polymer spheres are used either as an ultrasonic contrast agents or controlled drug delivery microcapsules. The power spectrum of the ultrasonic backscattered signal was calculated from the resonance scattering theory for the gas bubbles surrounded by elastic shield. The size distribution of the measured microspheres was included in the calculations. In experiment, the backscattered power spectrum of measured sample was recorded by Siemens Antares ultrasonic scanner. Radio frequency (RF) data was recorded for 2.5 - 6.7 MHz transmitted ultrasonic frequencies. The backscattered spectra were calculated by Matlab software and subtracted from the transmitter spectrum, recorded as an echo from the perfect reflector. The particle size in measured sample was 12 µm mean š 8 µm sd. The resonance frequency, measured under the microscope, was 0.60 MHz for 45 µm diameter microsphere which corresponds to 2.25 MHz for 12 µm sphere. The sample volume was 10cm? and the mean quantity of scatterers was 6ź103/cm?. In conclusion, measured spectra matched those calculated from theory. The use of ultrasonic scanner with RF data output and the high sensitivity, wide bandwidth ultrasonic transducer allows to measure backscattered signal from the very small quantity of resonance scatterers with satisfactory results at 40 dB signal to noise ratio.

3

Polymer microspheres with immobilized enzymes and other proteins as materials for biosensors

Słomkowski S., Miksa B., Basinska T., Gambhir A.G., Kumar A., Malhotra B. D.

Biocybernetics and Biomedical Engineering

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2001

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Vol. 21, no. 4

49-65

EN

Poly(styrene/acrolein) (P(S/A)), poly(styrene/ !..-t-butoxy-!..-vinylbenzylpolyglycidol) (P(S/VB-PGL)), and poly(pyrrole/acrolein) (P(P/A)) microspheres were synthesized by emulsifier-Iess emulsion-precipitation copolymerization (P(S/A) and (P(S/VB-PGL)) and/or by sequential redox emulsion and precipitation polymerizations (P (P/A)). These microspheres were used for immobilization of glucose oxidase (GOD), urease (Urs) and human serum albumin (HSA). Activity of immobilized enzymes has been determined. Model biosensor elements, based on microsphere-enzyme conjugates, for oximetric (glucose) and potentiometric (urea) detection have been investigated. A new type of antibody (anti-HSA) detection system based on changes in electrophoretic mobility of microspheres with immobilized antigens (HSA) was designed and its effectiveness was experimentally verified.

PL

Mikrosfery z poli(styren/akroleiny) (P(S/A)), poli(styren/..-t-butoksy-..-winylobenzylpoliglicydolu) (P(S/VB-PGL) i poli(pirol/akroleiny) (P(P/A)) syntezowano stosując polimeryzację emulsyjną bez środków powierzchniowych. Na tych mikrosferach immobilizowano oksydazę glukozową (GOD), ureazę (Urs) i albuminę z ludzkiej surowicy (HSA). Określono aktywność immobilizowanych enzymów. Zbadano właściwości modelowych bioczujników wykorzystujących sprzężenie mikrosfer i enzymów: oksymetrycznego - detekcja glukozy i potencjometrycznego - dla mocznika. Wykonano i zbadano właściwości nowego układu detekcyjnego przeciwciała (przeciw - HSA) wykorzystującego elektroforetyczną ruchliwość mikrosfer z immobilizowanymi antygenami (HSA).

4

Polymer microspheres: synthesis, properties and application in modern diagnostics

Słomkowski S.

Biocybernetics and Biomedical Engineering

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1999

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Vol. 19, no. 1

155-171

EN

This paper illustrates various methods suitable for synthesis of polymer microspheres in the range of diameters from ca. 100 nm to a few micrometers and describes basic properties of these particles. Procedures allowing to adsorb and/or to immobilize covalently, in the controlled manner, macromolecules of proteins, in particular human serum albumin (HSA), gamma globulins (-yG), horseradish peroxidase (HRP), and glucose oxidase (GOD) on the microspheres and results of evaluation of their biological activity after immobilization are described. Examples of application of microspheres with immobilized antigens and/or antibodies in aggregation tests are given. Modern types of dry tests based on polymer microspheres and methods allowing to obtain monolayers of microspheres immobilized onto solid supports are discussed. Their potential usefulness for fabrication of biosensors is noted.

PL

W pracy przedstawiono metody syntezy mikrosfer polimerowych o średnicach od 100 nm do kilku mikrometrów oraz opisano podstawowe właściwości tych cząstek. Omówiono sposoby umożliwiające kontrolowaną adsorpcję lub immobilizację kowalencyjną białek na mikrosferach, w szczególności albuminy surowicy ludzkiej (BSA), gamma globulin (...G), peroksydazy z chrzanu (BRP) i oksydazy glukozy (GOD), oraz przedstawiono wyniki oceny aktywności biologicznej immobilizowanych białek. Podano przykłady zastosowań mikrosfer, z immobilizowanymi antygenami lub przeciwciałami, w testach agglutynacyjnych. Omówiono zasadę nowych "suchych" testów diagnostycznych oraz metodę immobilizacji monowarstw mikrosfer na podłożu stałym. Przedyskutowano przydatność tej metody do wytwarzania biosensorów.