Search results for " swelling"

Thermo-mechanical analysis of irradiation swelling and design optimization of the IFMIF target assembly with bayonet backplate

2017

Abstract The availability of a high flux neutron source for testing candidate materials under irradiation conditions, which will be typically encountered in future fusion power reactors (ITER, DEMO, FPR), is a fundamental step towards the development of fusion energy. To this purpose, the International Fusion Materials Irradiation Facility (IFMIF) represents the reference option to provide the fusion community with a DEMO-relevant neutron source capable of irradiating samples at a damage rate of up to 20 dpa/fpy (in steel) in a volume of 0.5 l. In the framework of the engineering design activities of IFMIF, ENEA is committed in the design of the lithium target assembly (TA) with removable (…

Postmortale Ver�nderungen am Gehirn

1963

1. Den Ergebnissen einer Grundversuchsreihe an nicht vorgeschadigten Ratten uber postmortale und artefizielle Zell- und Gewebeveranderungen wurden die Befunde bei mit Histamin, Adrenalin vorbehandelten Tieren sowie denen nach Erstickungstod und dem Tod nach Hirntrauma erhobenen Befunde gegenubergestellt. 2. Die Auffassungen uber einen sich nach dem Tod vollziehenden dreiphasigen Strukturwandel und bezuglich der Bedeutung der beim Todeseintritt bestehenden kolloidalen Struktur fur den Typ der postmortalen Veranderungen wurden durch die erganzenden Untersuchungen bestatigt. 3. Die widerspruchsvoll erscheinenden Befunde der bei der Sektion in Erscheinung tretenden Zustandsbilder der sog. Hirns…

Reversed sexual conflict in a promiscuous antelope.

2007

SummaryA general tenet of sexual conflict theory is that males have higher optimum mating rates than do females and therefore should be more persistent when it comes to mating. However, in promiscuous species, females might benefit from high mating rates as a result of increased conception probability with favored males, whereas favored males benefit from mating selectively because of sperm depletion. When this results in higher optimum mating rates for females than for males, there is potential for reversed sexual conflicts between persistent females and resistant males. Here I report evidence of such a reversed sexual conflict in a promiscuous antelope, the African topi. Rather than matin…

Heterogeneity of osteogenesis imperfecta. Biochemical and morphological findings in a case of type III according to Sillence.

1986

A male infant with pale-blue sclerae, who died at the age of 6 weeks through the aspiration of food, presented multiple fractures and deformation of the long tubular bones. The clinical and radiological findings and the course indicated osteogenesis imperfecta, type III, according to Sillence's classification. The family history was unremarkable. Light and electron microscopic studies of iliac crest bone obtained postmortem, showed an abrupt interruption of endochondral ossification, with an active periosteal ossification. In the region of the fractures, a mixed desmochondral callus was seen. The endoplasmic reticulum of the osteoblasts was markedly dilated, the mitochondria were swollen. T…

Training-induced protection and effect of terminated training on exercise-induced damage and water content in mouse skeletal muscles.

1995

Muscle swelling in connection with training-induced protection against exercise-induced damage and the disappearance of the protective adaptation after termination of training was studied in male NMRI-mice, aged 8 weeks at the beginning of the experiment. Mice were randomly assigned to several different treatment groups (training, training-exercise, exercise, detraining, detraining-exercise, together with their respective controls). Training and prolonged exercise sessions were performed by running uphill (6 degrees) on a motor-driven treadmill. Muscle damage was estimated by the total activity of beta-glucuronidase and water content from the red parts of m. quadriceps femoris (MQF), m. sol…

CHARACTERIZATION OF RUBBERIZED ASPHALT FOR RAILWAY SUB-BALLASTS

Tesi di dottorato sotto la supervisione del professore Gaetano di Mino del Dipartimento di Ingegneria Civile di Palermo), come borsista Marie-Curie all'interno del progetto SUPRITN 2013/2017. Il mio lavoro e la linea della ricerca riguarda i conglomerati bituminosi con granulato di gomma per lo strato di sub-ballast nelle linee ferroviarie. L’attività di ricerca comprende il mix-design dell’asfalto con aggiunta di gomma, la caratterizzazione e le prestazioni per la ferrovia in termini di comportamento meccanico e lo smorzamento delle vibrazioni. In particolare con l’avvento dell’alta velocità, diversi studi hanno evidenziato ottime caratteristiche fisico-meccaniche per ciò che riguarda il c…

Water diffusion and swelling stresses in ionizing radiation cured epoxy matrices

2017

Abstract In this work a DGEBF epoxy monomer was cured by electron beam radiation in the presence of an iodonium salt and the obtained system was hydrothermally aged as such and also after a thermal treatment, in order to obtain two systems having different uniformity in the cross-linking degree. On both systems, the transient stress field arising from swelling was measured and monitored by an optical Photoelastic technique and the results were commented with reference to a thermally cured epoxy system containing the same monomer and already discussed in a previous work. Beam samples with identical dimensions, obtained from the irradiated systems, have been aged at 80 °C in water, and charac…

Water diffusion and swelling stresses in highly crosslinked epoxy matrices

2016

Abstract The present work investigates the swelling induced stresses arising in two epoxy systems during water uptake. The analysed systems are two epoxy resin based on DGEBA monomer and DGEBF monomer respectively, both fully cured by DDS amine. The systems achieve different cross-link density degrees, and are characterised by high glass transition temperatures ranging between 200 and 230 °C. Both epoxies have been conditioned in deionized water baths at two different temperatures (50 °C and 80 °C). A desorption process at room temperature in a dry airborne environment was performed after saturation. Dynamic Mechanical Thermal Analysis, carried out at the various stages of hydrothermal cond…

Fracture Toughness of Hydrothermally Aged Epoxy Systems with Different Crosslink Density

2015

Abstract The present work investigates the fracture toughness behaviour of Single Edge Notched Bending (SENB) samples of epoxy systems subject to water uptake aging. Two epoxy systems with a significantly different Glass Transition Temperature, T g , are in particular considered: a typical commercial non-aeronautical grade resin matrix for composite applications, reaching a T g of 90 °C, and a DGEBA+DDS epoxy system achieving a T g of 230 °C.The materials have been conditioned by hydrothermal aging in a thermal bath at the temperature of 50 °C. TransmissionPhotoelastic Stress Analysisis carried outon SENB samples during water aging, monitoring the presence and evolution of swelling stresses…

Effect of relative humidity on carvacrol release and permeation properties of chitosan based films and coating

2014

International audience; The influence of water vapour conditions on mass transport and barrier properties of chitosan based films and coatings were studied in relation to surface and structural properties. Water contact angles, material swelling, polymer degradation temperature, barrier properties (PO2, PCO2, WVP) and aroma diffusion coefficients were determined. The solvent nature and the presence of carvacrol influenced the surface and structural properties and then the barrier performance of activated chitosan films. Increasing RH from 0% to 100% led to a significant increase in material swelling. The plasticization effect of water was more pronounced at high humid environment, while at …