9,178 research outputs found
The Impact of Chronic Liver Diseases on the Level of Heart-Type Fatty Acid-Binding Protein (H-FABP) Concentrations
Objectives: Heart-type fatty acid binding-protein (H-FABP) has been reported to be a potential novel biochemical marker for the early diagnosis of acute myocardial infarction (AMI). The presence of H-FABP in the liver has not been reported. The aim of this study was to compare the effect of chronic liver diseases on the level of H-FABP concentrations. Methods: The effects of chronic liver diseases including infective hepatitis and cirrhosis on the concentration of H-FABP was studied in a small group of patients (n=10, mean age ±SD = 58.33 ± 7.19 years). The serum concentrations of the following markers were measured: H-FABP, alanine aminotransferase (ALT) and bilirubin and compared with a reference control group (20 healthy blood donors, mean age ±SD = 63.8 ±8.01). Results: The serum concentrations of these markers in the control group as compared to patients with chronic liver disease were as follows (mean ± SD): H-FABP = 6.86 ±2.21 µg/L versus 6.44 ±3.06 µg/L (p = NS); ALT = 29.8 ±14.7 U/L versus ALT = 198.67 ±122.89 U/L (p < 0.0005) and bilirubin = 9.6 ±4.0 µmol/L versus bilirubin = 100.89 ±87.85 µmol/L (p < 0.0001). Conclusion: These data illustrate clearly that there is no significant interference with the normal concentration of H-FABP in the presence of liver diseases, despite the significant elevation of liver enzymes and proteins. These data may support a useful role of H-FABP for the diagnosis of myocardial injury in patients with liver diseases
Improving performance of CFRP retrofitted RC members using rubber modified epoxy (ongoing research)
Although the method of external attachment of CFRP to the concrete members is the most effective and economical solution for strengthening and repairing concrete structure in the century, the bonding issue between CFRP and the hosting surface still a challenge for the structural engineers. Many solutions are proposed to overcome the early debonding failure in the strengthened members. This paper reports an ongoing experimental program for testing CFRP retrofitted RC beams and slabs. Fifteen RC beams of dimensions 150x250x2300mm and twelve two- way RC slabs of size 85x1670x1670mm will be strengthened using different types of epoxies, different configurations and variable number of layers of CFRP strips (MBrace-230). Rubber modified epoxy will be used for carbon fibre external attachment using wet lay-up method. Loading frame of 500 kN capacity will be used for beams testing. While for applying uniformly distributed load on the slabs a purpose built attachment will be used. The experimental results will report on the ultimate load, failure mode, mid-span deflection, strains readings in different locations and the ductility for both groups of strengthened beams and slabs. A mathematical model will be developed to predict the behavior of RC beams and two-way slabs
Experimental investigation on CFRP-steel bond properties using ionic liquid
Solving the problem of pre mature debonding of CFRP retrofitted structure is a main concern for most of structural engineers nowadays. Reducing the brittleness of the bonding agent at the CFRP/concrete interface is a major factor to avoid this behaviour. In this research, the effect of modifying the bonding agent using different percentages of ionic liquid (IL) is investigated. This paper reports on an experimental investigation on the behaviour of modified epoxy resin with IL. Steel plates were used as hosting surface of the CFRP laminates, the laminates were attached to the steel surface using the IL modified epoxy. The shear mechanism at the interface of CFRP laminates to steel plates is discussed considering the relationship between the shear and the slip at the interface. The shear stress- displacement are traced for all specimens, the results are compared with control test prepared using unmodified epoxy. A 20% IL modified epoxy shows improved Behaviour. The improvement is with respect to ductility enhancement of the overall behaviour
Bond properties of rubber modified epoxy
In this paper, the bond integrity of unmodified and rubber-modified epoxy used for bonding the carbon fibre sheets to the hosting steel surface was investigated. The rigidity of the bonding agent is one of the factors that have a significant role in the premature failure (debonding) of this application. In order to overcome this issue, a series of experiments were conducted on the steel plates using the epoxy resin modified by CTBN and ATBN reactive liquid polymers, in addition to the unmodified epoxy resin. The interface between the carbon fibre matrix and the hosting surface is subjected to a longitudinal shear force for which the corresponding displacement is recorded. The shear stress-strain relationship for the tested specimen is plotted. The result shows that, the bond behaviour of modified epoxy using CTBN and ATBN reactive liquid polymers was improved in terms of ductility and toughness
Magnetic and Optical properties of strained films of multiferroic GdMnO3
The effects of strain on a film of mulitferroic GdMnO3 are investigated using
both magnetometry and magneto-optic spectroscopy. Optical spectra, in the
energy range 1.5eV - 3.5eV, were taken in Faraday geometry in an applied
magnetic field and also at remanence. This yielded rich information on the
effects of strain on the spin ordering in these films. Epitaxial films of
GdMnO3 were grown on SrTiO3 and LaAlO3 substrates. The LaAlO3 was twinned and
so produced a highly strained film whereas the strain was less for the film
grown on SrTiO3. The Ne\'el temperatures and coercive fields were measured
using zero field data and hysteresis loops obtained using a SQUID magnetometer.
Optical absorption data agreed with earlier work on bulk materials. The two
well known features in the optical spectrum, the charge transfer transition
between Mn d states at ~2eV and the band edge transition from the oxygen p band
to the d states at ~3eV are observed in the magnetic circular dichroism;
however they behaved very differently both as a function of magnetic field and
temperature. This is interpreted in terms of the magnetic ordering of the Mn
spins.Comment: 9 pages of text including figure
On Using Magnetic and optical methods to determine the size and characteristics of nanoparticles embedded in oxide semiconductors
Films of oxides doped with transition metals are frequently believed to have
magnetic inclusions. Magnetic methods to determine the amount of nanophases and
their magnetic characteristics are described. The amount of the sample that is
paramagnetic may also be measured. Optical methods are described and shown to
be very powerful to determine which defects are also magnetic.Comment: Manuscript of poster to be presented at MMM-Intermag 2010. Accepted
for publication in Magnetic Trans of IEE
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