Positron annihilation lifetime (PAL) technique has been employed to
study the microstructural changes of polyurethane (PU), EUXIT 101
and epoxy risen (EP), EUXIT 60 by Gamma-ray irradiation with the
dose range (95.76 - 957.6) kGy. The size of the free volume hole and
their fraction in PU and EP were determined from ortho-positronium
lifetime component and its intensity in the measured lifetime spectra.
The results show that the irradiation causes significant changes in the
free volume hole size (Vh) and the fractional free volume (Fh), and
thereby the microstructure of PU and EP. The results indicate that
the γ-dose increases the crystallinity in the amorphous regions of PU
and increase the cross-linking of EP.
Recent developments in two main phases of cumulus cloud studies are discussed; first the relations between the clouds and their energy sources in the subcloud layer and second, the interaction between the clouds and their environment in the cloud layer. Under the first heading, the various originating impulses for cumulus formation are mentionitd. and how the character of this impulse affects the spacing, scale and temperature structure of the clouds. The possible origins of trade cumuli are considered.
It is well known that monotherapy does not provide therapeutic response in all hypertensive. Somepatients show an excellent response, while in others there is a poor response. Combinationantihypertensive therapy is administered when blood pressure is inadequately controlled bymonotherapy to achieve a balanced and additive antihypertensive effect with minimum adverse effects.Both angiotensin converting enzyme (ACE) inhibitors and dihydropyridine type of calcium antagonistsare well established and widely used in monotherapy. An understanding of differences in themechanism of action of these agents allows a logical approach for the use of these agents as acombination therapy. This study was designed to evaluate the possible beneficial
... Show MoreIncident laser power and concentration effects on fluorescence emission from DCM dye in PMMA polymer have been investigated. Different concentrations of the dye were used. It was found that the fluorescence intensity increased with increasing of the concentration of the dye, with a red shift. In addition, it was found that the fluorescence intensity increased with the increase of the incident laser power I0.
The present study aimed to evaluate the effect of lead exposure on hemopoetic system (through the index delta-Aminolevulinic acid dehydratase ?-ALAD activity & hemoglobin concentration (Hb) ) and on iron status (levels of iron Fe, Ferritin Fr, Total iron binding capacity TIBC, percentage of transferine saturation TF%) in 44 Iraqi worker at lead batteries factory. Workers divided into two groups: smokers(n=21) mean aged (37.33±4.82 year)and non smokers(n=23) mean aged(40.78±7.89 year) and 45 healthy subjects mean aged (33.97±5.08)as control group . Activity of ?-ALAD ratio shows significant decrease (p ? 0.05) ,while Hb and hematocrit Hct were non significant (p ? 0.05) in smoker workers more than non smoker as compared to control . The r
... Show MoreExperiments research is done to determine how saturated stiff clayey soil responds to a single impulsive load. Models made of saturated, stiff clay were investigated. To supply the single pulse energy, various falling weights from various heights were tested using the falling weight deflectometer (FWD). Dynamic effects can range from the major failure of a sensitive sensor or system to the apparent destruction of structures. This study examines the response of saturated stiff clay soil to a single impulsive load (vertical displacement at the soil surface below and beside the bearing plates). Such reactions consist of displacements, velocities, and accelerations caused by the impact occurring at the surface depth induced by the impact loads
... Show MoreThe photooxidative degradation process of plastics caused by ultraviolet irradiation leads to bond breaking, crosslinking, the elimination of volatiles, formation of free radicals, and decreases in weight and molecular weight. Photodegradation deteriorates both the mechanical and physical properties of plastics and affects their predicted life use, in particular for applications in harsh environments. Plastics have many benefits, while on the other hand, they have numerous disadvantages, such as photodegradation and photooxidation in harsh environments and the release of toxic substances due to the leaching of some components, which have a negative effect on living organisms. Therefore, attention is paid to the design and use of saf
... Show MoreObjectives: Recently, there have been important advances in the clinical application of targeted hybrid near-infrared (NIR) fluorescent-radioactive tracers. ICG-99mTc-nanocolloid, for example, is already being used by some centres for sentinel lymph node biopsy in head and neck cancer. The radioactive component allows imaging at depths which would not be possible with NIR alone and, once exposed, the NIR fluorescence reporter can be imaged at very high resolution. Gamma detection is currently carried out with a separate hand-held gamma camera or with a non-imaging probe. Visualisation of NIR fluorescence during surgery requires a dedicated NIR camera, several of which are available commercially. We describe a novel hand-held hybrid NIR-gamm
... Show MoreBackground: White spot lesions are esthetic problems caused by subsurface enamel demineralization that seen as white opacity. Aim of the study: This study aimed to evaluate and to compare the color change after the treatment of the white spot lesions with resin nϔtrton and micro abrasion. Materials and Methods: rtϔ white spot lesions were generated on 48 premolar teeth by the use of a demineralization solution. The teeth were randomly divided using the Diagnodent into three study groups (16 teeth for each group) depending on the depth of the induced lesions: outer enamel, inner enamel and outer dentine. Then each group was fatherly subdivided into two groups (8 teeth for each group) the ϔrst group was treated wit
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