Lepidophyma gaigeae

Number of Pages: 4Integrative BiologyGeological Science

Characterization by full-size testing of pultruded frame joints for the Startlink house

Presented in this paper are test results to determine the moment-rotation characteristics of joint details for a portal frame specific to a pultruded fiber reinforced polymer assembly for the Startlink house. Two joints having beam-to-column dowel connections, with and without extra adhesively bonding, were statically loaded in increments of moment or rotation to ultimate failure. The floor beam and stud column members are bespoke closed-sections developed for the Startlink lightweight building system. The serviceability design calculations for the demonstrator house to be constructed in Bourne, England, assumed the frame’s joints to be rigid. Clauses in EN 1993-1-8:2005 have been applied to classify the measured rotational stiffnesses against the rigid requirement, and an evaluation is made of the modes of failure with respect to the joint’s design moments. Only the joint with extra bonding between the mating surfaces of members is found to be classified as rigid. Both joints are shown to have an acceptable joint strength

Laterally unrestrained bearing strength of hot-wet conditioned pultruded FRP material

Presented in this paper are test results of a study pertaining to the reduction in bearing strength due to the effect of hot-wet conditioning on specimens cut from a polyester matrix based pultruded FRP structural shape. A total of 100 coupons (for 20 batches of five) were immersed in distilled water for three and six months at a constant temperature of 40°C. Subsequently, they were load tested using stainless steel ‘pins’ of M10 and M20 sizes with material orientations of 0o, 45o and 90o to the direction of pultrusion. Furthermore, this test series considered the effect of loading with and without bolt thread in the bearing zone. Testing employed a non-standard set-up that accommodates smaller test coupons, allowing material to be sourced from the web and flange of a 254×254×9.53 mm wide flange shape. An evaluation of the salient results provides characteristic bearing strength values (in accordance with Annex D of EN1990) and comparisons are drawn between equivalent strengths for non-aged (zero months) material from a previous test series. The degree of strength reduction is found to be influenced by both the ‘pin’ size and type, and observations are drawn towards the safe and reliable design of bolted connections

Reinforcing attitudes in a gatewatching news era: individual-level antecedents to sharing fact-checks on social media

Despite the prevalence of fact-checking, little is known about who posts fact-checks online. Based upon a content analysis of Facebook and Twitter digital trace data and a linked online survey (N = 783), this study reveals that sharing fact-checks in political conversations on social media is linked to age, ideology, and political behaviors. Moreover, an individual’s need for orientation (NFO) is an even stronger predictor of sharing a fact-check than ideological intensity or relevance, alone, and also influences the type of fact-check format (with or without a rating scale) that is shared. Finally, participants generally shared fact-checks to reinforce their existing attitudes. Consequently, concerns over the effects of fact-checking should move beyond a limited-effects approach (e.g., changing attitudes) to also include reinforcing accurate beliefs.Accepted manuscrip

Black hole thermodynamics from simulations of lattice Yang-Mills theory

We report on lattice simulations of 16 supercharge SU(N) Yang-Mills quantum mechanics in the 't Hooft limit. Maldacena duality conjectures that in this limit the theory is dual to IIA string theory, and in particular that the behavior of the thermal theory at low temperature is equivalent to that of certain black holes in IIA supergravity. Our simulations probe the low temperature regime for N <= 5 and the intermediate and high temperature regimes for N <= 12. We observe 't Hooft scaling and at low temperatures our results are consistent with the dual black hole prediction. The intermediate temperature range is dual to the Horowitz-Polchinski correspondence region, and our results are consistent with smooth behavior there. We include the Pfaffian phase arising from the fermions in our calculations where appropriate.Comment: 4 pages, 4 figure

Influence of boundary conditions and geometric imperfections on lateral–torsional buckling resistance of a pultruded FRP I-beam by FEA

Presented are results from geometric non-linear finite element analyses to examine the lateral torsional buckling (LTB) resistance of a Pultruded fibre reinforced polymer (FRP) I-beam when initial geometric imperfections associated with the LTB mode shape are introduced. A data reduction method is proposed to define the limiting buckling load and the method is used to present strength results for a range of beam slendernesses and geometric imperfections. Prior to reporting on these non-linear analyses, Eigenvalue FE analyses are used to establish the influence on resistance of changing load height or displacement boundary conditions. By comparing predictions for the beam with either FRP or steel elastic constants it is found that the former has a relatively larger effect on buckling strength with changes in load height and end warping fixity. The developed finite element modelling methodology will enable parametric studies to be performed for the development of closed form formulae that will be reliable for the design of FRP beams against LTB failure