Performance of Sentry-Glas-laminated metal-reinforced glass beams at 23, -20, and 60 ºC

Keywords: 1=reinforced 2=beam 3=SentryGlas 4=interlayer 5=temperature 6=redundancy. Abstract To validate the novel concept of laminating a metal reinforcement to a glass beam using a SentryGlas (SG) interlayer, a series of bending tests has been performed at 23, -20 and 60°C on 1.5 m SG-laminated metal-reinforced glass beams. The beams consisted of three glass layers with a stainless steel box section laminated in between the glass at the lower edge. The test results showed high redundancy of the beam specimens at all tested temperature levels. However, the specific response of the beam specimens varied at different temperature levels. At 23°C the beam specimens showed the highest residual strength, whereas the residual strength was reduced at both -20 and 60°C. This difference in response was caused by a difference in glass cracking behaviour and the occurrence of plastic hinges in the beams. These plastic hinges limited the residual strength of the beam and probably originated from a more brittle response of the SG at -20°C and a lower metal-to-glass bond strength of the SG at 60°C. Since the SG-laminated metal-reinforced glass beams showed promising results, future research at TU Delft will further explore the possibilities of this concept

Hereditary and acquired transthyretin-mediated amyloidosis

We describe three cases, two 70-year-old males with mainly cardiac symptoms and a 34-year-old male with gastro-intestinal and neurologic symptoms. Each patient was shown to have a distinctive type of transthyretin-mediated amyloidosis (ATTR). ATTR amyloidosis is a life-threatening disease characterised by the extracellular deposition of pathogenic transthyretin (TTR). A distinction is made between hereditary ATTR (ATTRv), in case of a pathogenic TTR mutation, and the acquired wild-type ATTR (ATTRwt). The prevalence of ATTR amyloidosis is probably underestimated. The variety of symptoms means that patients often visit several specialists, resulting in an average diagnostic delay of two to three years. Because of the development of new therapeutic possibilities, early diagnosis becomes more important to allow initiation of therapy at an early stage of the disease. Family members should be screened and asymptomatic carriers should undergo follow-up.</p

Recognition and diagnosis of sleep disorders in Parkinson's disease

Contains fulltext : 109296.pdf (publisher's version ) (Open Access)Sleep disturbances are among the most frequent and incapacitating non-motor symptoms of Parkinson's disease (PD), and are increasingly recognized as an important determinant of impaired quality of life. Here we review several recent developments regarding the recognition and diagnosis of sleep disorders in PD. In addition, we provide a practical and easily applicable approach to the diagnostic process as a basis for tailored therapeutic interventions. This includes a stepwise scheme that guides the clinical interview and subsequent ancillary investigations. In this scheme, the various possible sleep disorders are arranged not in order of prevalence, but in a 'differential diagnostic' order. We also provide recommendations for the use of sleep registrations such as polysomnography. Furthermore, we point out when a sleep specialist could be consulted to provide additional diagnostic and therapeutic input. This structured approach facilitates early detection of sleep disturbances in PD, so treatment can be initiated promptly

Nature’s nations: the shared conservation history of Canada and the USA

Historians often study the history of conservation within the confines of national borders, concentrating on the bureaucratic and political manifestations of policy within individual governments. Even studies of the popular expression of conservationist ideas are generally limited to the national or sub-national (province, state, etc.) scale. This paper suggests that conservationist discourse, policy and practice in Canada and the USA were the products of a significant cross-border movement of ideas and initiatives derived from common European sources. In addition, the historical development of common approaches to conservation in North America suggests, contrary to common assumptions, that Canada did not always lag behind the USA in terms of policy innovation. The basic tenets of conservation (i.e. state control over resource, class-based disdain for subsistence hunters and utilitarian approaches to resource management) have instead developed at similar time periods and along parallel ideological paths in Canada and the USA

Numerical analyses of the effect of SG-interlayer shear stiffness on the structural performance of reinforced glass beams

This paper focuses on the numerical modelling of SentryGlas-laminated reinforced glass beams. In these beams, which have been experimentally investigated in preceding research, a stainless steel reinforcement section is laminated at the inner recessed edge of a triple-layer glass beam by means of SentryGlas (SG) interlayer sheets. The current contribution numerically investigates the effect of the SG-interlayer shear stiffness on the overall structural response of the beams. This is done by means of a 3D finite element model in which the individual glass layers, the SG-interlayers and the reinforcement are incorporated. In the model, the glass parts are allowed to crack, but all other parts are assumed linear elastic throughout the analyses. By changing the shear modulus of the SG-interlayer in multiple analyses, its contribution to the overall structural performance of the beams – especially at the post-breakage stage – is investigated. From the results of the analyses it is observed that the residual load-bearing capacity, i.e. the load-bearing capacity after glass fracture, increases with an increasing shear modulus of the SG-interlayer. Furthermore, the load-displacement response from the numerical model is predicting experimental observations very well. However, the crack pattern resulting from the numerical model is not matching the experimental observations. Further studies are thus needed to fully understand the mechanisms involved in the structural behaviour of SGlaminated reinforced glass beams