Home About us Contact
|
Home About us Contact | ||
|
|
||
Damaged Areas (damaged + area)
Selected AbstractsAnalysis of the behaviour of the structural concrete after the fire at the Windsor Building in MadridFIRE AND MATERIALS, Issue 2 2010E. Menéndez Abstract The analysis of the concrete subjected to high temperatures is usually undertaken by means of tests specifically designed and carried out in the laboratory, or by using theoretical approaches using standardized curves for theoretical fires. An analysis by different techniques has been carried out on structural concrete to real fire of Windsor Building in Madrid, which was severally damaged by a fire in 2005. These techniques are X-ray diffraction, differential thermal and thermogravimetric analysis and backscattered electron microscopy with dispersive X-ray microanalysis. Samples of the concrete were taken from different floors in the building and analyses were carried out at different depths starting from the surface exposed to the fire itself. The analysis allows the damaged area to be limited as well as situating the 500,C isotherm in the concrete element. In accordance with the results obtained, the damage is limited to just a few centimeters from the surface exposed to the fire itself, in spite of its prolonged exposure to the fire. This would justify that the concrete has demonstrated a suitable resistant behaviour. Likewise, it can be deduced from the results obtained that the fire, to which the concrete was subjected, can be qualified as severe. Also, these results can confirm that the calculation hypothesis in the project is correct in relation to the fire resistance exigencies of the concrete. Copyright © 2009 John Wiley & Sons, Ltd. [source] Selenium and selenoproteins in the brain and brain diseasesJOURNAL OF NEUROCHEMISTRY, Issue 1 2003Jun Chen Abstract Over the past three decades, selenium has been intensively investigated as an antioxidant trace element. It is widely distributed throughout the body, but is particularly well maintained in the brain, even upon prolonged dietary selenium deficiency. Changes in selenium concentration in blood and brain have been reported in Alzheimer's disease and brain tumors. The functions of selenium are believed to be carried out by selenoproteins, in which selenium is specifically incorporated as the amino acid, selenocysteine. Several selenoproteins are expressed in brain, but many questions remain about their roles in neuronal function. Glutathione peroxidase has been localized in glial cells, and its expression is increased surrounding the damaged area in Parkinson's disease and occlusive cerebrovascular disease, consistent with its protective role against oxidative damage. Selenoprotein P has been reported to possess antioxidant activities and the ability to promote neuronal cell survival. Recent studies in cell culture and gene knockout models support a function for selenoprotein P in delivery of selenium to the brain. mRNAs for other selenoproteins, including selenoprotein W, thioredoxin reductases, 15-kDa selenoprotein and type 2 iodothyronine deiodinase, are also detected in the brain. Future research directions will surely unravel the important functions of this class of proteins in the brain. [source] GRAZING IMPACT OF, AND INDIRECT INTERACTIONS BETWEEN MESOGRAZERS ASSOCIATED WITH KELP (LAMINARIA DIGITATA),JOURNAL OF PHYCOLOGY, Issue 1 2010Markus Molis Little is known about the indirect effects of nonlethal grazing impacts in mesograzer,seaweed interactions. Using laboratory experiments, the effect of grazing by the seasonally abundant kelp-associated gastropod Lacuna vincta on subsequent kelp consumption by one kelp-associated (Idotea granulosa) and one nonassociated species of isopod (I. emarginata) was determined. Measurements of the toughness and elemental composition of different parts of the sporophyte of Laminaria digitata (Huds.) J. V. Lamour., as well as grazer-induced changes in the palatability of the blade, were conducted to explore possible mechanisms of indirect effects. In situ grazing pressure was the highest between July and September, with the blade being the preferred part of the kelp sporophyte, despite missing differences in the elemental composition among kelp parts. The laboratory experiments supported our hypotheses in that kelp consumption by both species of isopods was lower on intact than on L. vincta,damaged areas of the blade. This pattern was not caused by grazing-induced changes in blade palatability. Instead, the observed increase in isopod consumption following grazing by L. vincta resulted more likely from the combined effects of a reduction in the toughness of L. vincta,damaged kelp blades and some unknown gastropod cue(s). These results suggest that kelp-associated and nonassociated mesograzers may benefit from the nonlethal grazing impact of L. vincta due to changes in physical traits of the seaweed. Thus, the nonlethal grazing impact by one species of mesograzer can positively modify the trophic interactions between kelp and other potential competitors, suggesting that the interactions among mesograzers might be more complex than previously assumed. [source] Impact damage detection and degradation monitoring of wet GFRP composites using noncontact ultrasonicsPOLYMER COMPOSITES, Issue 8 2009K. Berketis Two different non-crimp glass fabrics with a polyester resin were used to produce laminated plates that were subjected to low velocity impact testing using three impact energy levels. The plates were immersed in water at 65°C for up to 24 months. The effectiveness of a traditional water coupled and an air-coupled ultrasonic C-Scan system was assessed in terms of damage size evaluation at various time intervals. The conditioned impacted plates were retested statically in compression to determine the residual strength for evaluation of damage tolerance. Weight change measurements revealed an initial increase due to water diffusion, followed by an extended decrease due to matrix dissolution at long-term immersion times. The use of water coupled pulse-echo ultrasonics proved ineffective after long-term water immersion as damaged areas became ultrasound-invisible. The contrast between impact damaged areas and water diffused areas was restored with the air-coupled C-scan. The macroscopic damage size was not affected by the long-term water immersion and the overall weight change while the residual compression strength was seemed to be dependent on the time of immersion and the size of the pre-existing impact damage. Calibrating the air-coupled system to a dry condition specimen, a good qualitative and quantitative indication of the degraded state of water immersed plates was obtained. This monitoring system for the degradation process seems to be very promising. POLYM. COMPOS., 2009. © 2008 Society of Plastics Engineers [source] Factors impacting on psychological distress and recovery after the 2004 Niigata,Chuetsu earthquake, Japan: Community-based studyPSYCHIATRY AND CLINICAL NEUROSCIENCES, Issue 5 2008Hideki Kuwabara md Aim:, This study was undertaken 5 months after the 2004 Niigata,Chuetsu earthquake in Japan to assess factors that impacted on psychological distress and its recovery. Methods:, Three thousand and twenty-six adult victims who lived in temporary shelter and in seriously damaged areas were evaluated by questionnaire. The questionnaire queried subject profile, degree of house damage, health status, and psychological distress using a 5-point scale before, immediately and 5 months after the earthquake. Results:, Immediately after the earthquake, 59.3% of the subjects had psychological distress. At 5 months after the earthquake, however, this percentage decreased to 21.8%. The psychological distress immediately after the earthquake was significantly serious in victims who: (i) were female; (ii) felt stronger fear of the earthquake and the aftershocks; (iii) lived at home or office after the earthquake; and (iv) were injured due to the earthquake or suffered from sickness after the earthquake. In contrast, the factors impairing psychological recovery 5 months after the earthquake were as follows: (i) being with unfamiliar member(s) during the night after the earthquake; (ii) serious house damage; (iii) living in temporary shelter or at a relative's home after the earthquake; and (iv) physical illness after the earthquake. Conclusion:, Despite differences between disasters, these results were consistent with those in some previous studies and may be useful for long-term mental care support. [source] | ||||||||||