Search results for "SITE"

Photocatalytic activity in gas–solid regime of ZnO-ZnAl2O4 composites

2011

Prevention of injuries among youth team sports : the role of decreased movement control as a risk factor

2017

Good movement control is essential in team sports that require fast-paced running, pivoting, jumping and landing. Alterations in dynamic neuromuscular control may cause significant stress on the musculoskeletal system, and increase the risk of both acute and overuse injuries. The purpose of this dissertation was to investigate the effectiveness of interventions to prevent sports injuries, the incidence and severity of overuse injuries, and the role of decreased movement control as a risk factor for future injuries in young team sports athletes. The study methods included a systematic literature review and meta-analysis of randomized controlled trials, a retrospective epidemiological investi…

Multi-functional Stabilizers-functionalized Carbon Nanotubes for advanced Ultra-High Molecular Weight Polyethylene-based Nanocomposites

2015

Stabilizing molecules, such as hindered phenols (both synthetic and naturally occurring), polyphenols and hindered amine light stabilizers, were covalently linked or physically absorbed onto outer surface of multi-walled carbon nanotubes (CNTs) and the obtained multi-functional fillers (Stab-f-CNTs) were dispersed in Ultra High Molecular Weight Polyethylene (UHMWPE) aiming at obtaining advanced nanocomposites with enhanced thermo- and/or photo-oxidative stability, electrical and mechanical properties. The chemical grafting or physical absorption of stabilizing molecules is confirmed by spectroscopic, spectrometric and thermo-gravimetric analyses, and the influence of the multi-functional na…

Dos conceptos de Estado en el debate constitucional español de 1931

2019

“Indagine sperimentale per la caratterizzazione meccanica di elementi strutturali misti in legno-acciaio e legno-acciaio-calcestruzzo"

2009

The paper reports the results of the research activity aimed to define the physical-mechanics characteristics of structural elements made of wood-steel, and/or wood-steel-concrete, jointed by steel con¬nectors. The elements used for the tests are: glulam beams with two dif¬ferent dimensions (110x240x4000 mms and 110x140x4000 mms); steel flats 100x6x4000 mms with holes  20 mms arranged like "quinconce"; steel connectors like: flat with 6 mms thickness;  18; angular; polymeric synthetic binder with epoxy base bicomponent (Xepox 40.3/5). Shear tests have been made to define the capacity for deformation and the re¬sistance of the different steel connectors. Moreover, bending tests have been m…

Toxicity of Dental Amalgams vs Composite Resins

2016

Ideal qualities of dental materials should include, in terms of biocompatibility, passivity towards oral tissues, so the material should not contain any leachable toxic and diffusible substances, neither release any harmful substance that can cause in time side effects, locally or generally. Even if amalgams are a group of dental materials with a long recorded history, many practitioners blame them, in contradiction with composite resins, especially for releasing free mercury into the body. On the other side, composite resins have reached great biocompatibility specifications, but also have many qualities that need more research, especially long term type.

The effect of defect location on coating fragmentation patterns under biaxial tension

2005

Fragmentation of a coating possessing orthogonal preferential crack propagation directions is modeled for equibiaxial tensile loading. Two plausible cracking scenarios are compared, caused by flaws randomly distributed over the area of the coating or along the coating fragment edges. The two fragmentation scenarios considered are shown to yield qualitatively different fragment patterns.

Influence of the Resin Layer Thickness at the Interface of Hybrid Metal-composite Co-cured Joints

2011

As discussed in literature, the accurate analysis of the modern co-cured joints between composite materials or between a metal and a composite material (hybrid joints) is complicated by the influence of the interface resin layer on the interface singular stress field. In such joints, in fact, there is not a proper adhesive layer and the thickness of the resin layer, that plays the role of the adhesive, is not constant due to the presence of the reinforcing fibers in the composite adherent. For this reason several authors assume that a generic co-cured joint can not be studied as a simple bi-material joint, without considering the particular characteristics of the actual resin layer. This pr…

Experimental Investigation on Stiffness and Strength of Single-Lap Z-Pinned Joints in a Laminated CFRP Stress-Ribbon Strip

2016

Carbon fiber-reinforced polymer (carbon-polymer) is an advanced lightweight composite material with high strength and excellent resistance to corrosion and fatigue. Over the past decades, application of fiber-reinforced polymers has been spread from the aerospace to other branches of industry such as automobile and civil engineering. Unidirectional carbon-polymers have a high potential for replacing steel in tensile members. Recently, the first carbonpolymer stress-ribbon bridge has been constructed in Germany. The non-laminated strip-loop carbon-polymer thin strips were used as the load bearing components in this bridge. In comparison with the laminated components, the applied cables are c…

Teknostressi ja sitä lieventävät mekanismit

2016

Teknologia on muuttanut ratkaisevalla tavalla ihmisten työntekoa ja oppimista. Laitteistojen ja ohjelmistojen jatkuvan kehityksen tarkoituksena on ollut tehdä elämästä ja arjesta helpompaa, mutta se on tuonut mukanaan myös ei-toivottuja sivuvaikutuksia. Ihmisten pyrkimykset selvitä tämän jatkuvasti kehittyvän tek- nologian mukana ovat aiheuttaneet teknostressiä, jolla tarkoitetaan suoraan tai epäsuoraan teknologian käytöstä johtuvia negatiivista vaikutuksia yksilöön. Teknostressin tiedetään aiheuttavan sekä psykologista, fyysistä että käyttäyty- misellistä kuormitusta. Tieto- ja viestintäteknologia on siis muuttanut työnteon kaavoja ja tuonut mukanaan uusia vaatimuksia. Työympäristössä tekn…