The design of haunched composite beam frames for buildings

This thesis examines the design and overall behaviour of haunched composite beam frames braced against sidesway. It has been compiled as a result of both a theoretical and an experimental study. A detailed design method is presented, which incorporates options for plastic or elasto-plastic analysis at the Ultimate Limit State. A method for checking the susceptibility to lateral instability in the hogging regions of composite beams is also presented, and it has been developed by using elastic energy theory. The design method is intended to be applied in conjunction with the British Standard for the design of steel-framed building structures, BS5950 Parts 1 and 3, although the engineering principles involved could be used with other countries’ codes. A detailed design example is also included to demonstrate the application of the method. A review of other relevant experimental and theoretical work has also been undertaken and is critically appraised where appropriate. The experimental programme carried out as part of this work involved two full-scale tests, and these are described. Particular attention was given to the stiffening details at the shallow end of the haunches, and several options were tested. The most successful proved to be that where full-depth web stiffeners were fitted at this position. Analyses of the tests are included and they show that the theoretical predictions are generally slightly conservative. A finite element model of the hogging region of a haunched composite beam was also developed, and this was applied to one of the tests. The results of this are presented. It is intended that this particular work will enable further computer simulations to be carried out. To enable early dissemination of the ideas developed in this thesis, during the course of this work an interim design guide, written jointly by this author and his industrial supervisor, Dr R M Lawson, was published by the Steel Construction Institute

The effects of stand characteristics on the understory vegetation in Quercus petraea and Q. cerris dominated forests

The shelterwood system used in Hungary has many effects on the composition and structure of the herb layer. The aim of our study was to identify the main variables that affect the occurence of herbs and seedlings in Turkey oak-sessile oak (Quercus cerris and Q. petraea) stands. The study was carried out in the Bükk mountains, Hungary. 122 sampling plots were established in 50-150 year old oak forests, where we studied the species composition and structure of the understorey and overstorey. The occurence of herbs was affected by canopy closure, the heterogenity and patchiness of the stand, the slope and the east-west component of the aspect. The composition of saplings was significantly explained by the ratio of the two major oak species in the stand and the proximity of the adult plants. An important result for forest management was that sessile oaks were able to regenerate almost only where they were dominant in the overstorey

State-of-the-Art on Composite Cold-formed Steel Flooring Systems

The current study presents a comprehensive review of the state-of-the-art on composite cold-formed steel flooring research over the past couple of years. The most relevant and significant literature references were reviewed to provide some profundity in the trends and development of the composite cold-formed steel floors. Advantages of this type of composite flooring system are also highlighted. A broad description of mainly two types of the composite floors mainly consisting cold-formed steel and concrete, and cold-formed steel and timber-based floorboards have been outlined in this study. The experimental and numerical investigations that have been carried out worldwide is likewise discussed in the paper. The most important aspects covered are shear connection behaviour, flexural and dynamic behaviour of the floors, and a brief description of fire testing

Differences in 5'untranslated regions highlight the importance of translational regulation of dosage sensitive genes

Background: Untranslated regions (UTRs) are important mediators of post-transcriptional regulation. The length of UTRs and the composition of regulatory elements within them are known to vary substantially across genes, but little is known about the reasons for this variation in humans. Here, we set out to determine whether this variation, specifically in 5’UTRs, correlates with gene dosage sensitivity. Results: We investigate 5’UTR length, the number of alternative transcription start sites, the potential for alternative splicing, the number and type of upstream open reading frames (uORFs) and the propensity of 5’UTRs to form secondary structures. We explore how these elements vary by gene tolerance to loss-of-function (LoF; using the LOEUF metric), and in genes where changes in dosage are known to cause disease. We show that LOEUF correlates with 5’UTR length and complexity. Genes that are most intolerant to LoF have longer 5’UTRs, greater TSS diversity, and more upstream regulatory elements than their LoF tolerant counterparts. We show that these differences are evident in disease gene-sets, but not in recessive developmental disorder genes where LoF of a single allele is tolerated. Conclusions: Our results confirm the importance of post-transcriptional regulation through 5'UTRs in tight regulation of mRNA and protein levels, particularly for genes where changes in dosage are deleterious and lead to disease. Finally, to support gene-based investigation we release a web-based browser tool, VuTR, that supports exploration of the composition of individual 5'UTRs and the impact of genetic variation within them

ACCESS, LRG-BEASTS, & MOPSS: Featureless Optical Transmission Spectra of WASP-25b and WASP-124b

We present new optical transmission spectra for two hot Jupiters: WASP-25b (M = 0.56~M$_J$; R = 1.23 R$_J$; P =~3.76 days) and WASP-124b (M = 0.58~M$_J$; R = 1.34 R$_J$; P = 3.37 days), with wavelength coverages of 4200 - 9100\AA\ and 4570 - 9940\AA, respectively. These spectra are from the ESO Faint Object Spectrograph and Camera (v.2) mounted on the New Technology Telescope (NTT) and Inamori-Magellan Areal Camera & Spectrograph on Magellan Baade. No strong spectral features were found in either spectra, with the data probing 4 and 6 scale heights, respectively. \texttt{Exoretrievals} and \texttt{PLATON} retrievals favor stellar activity for WASP-25b, while the data for WASP-124b did not favor one model over another. For both planets the retrievals found a wide range in the depths where the atmosphere could be optically thick ($\sim0.4\mu$ - 0.2 bars for WASP-25b and 1.6 $\mu$ -- 32 bars for WASP-124b) and recovered a temperature that is consistent with the planets' equilibrium temperatures, but with wide uncertainties (up to $\pm$430$^\circ$K). For WASP-25b, the models also favor stellar spots that are $\sim$500-3000$^\circ$K cooler than the surrounding photosphere. The fairly weak constraints on parameters are owing to the relatively low precision of the data, with an average precision of 840 and 1240 ppm per bin for WASP-25b and WASP-124b, respectively. However, some contribution might still be due to an inherent absence of absorption or scattering in the planets' upper atmospheres, possibly because of aerosols. We attempt to fit the strength of the sodium signals to the aerosol-metallicity trend proposed by McGruder et al. 2023, and find WASP-25b and WASP-124b are consistent with the prediction, though their uncertainties are too large to confidently confirm the trend.Comment: Accepted in AJ July 202

Design and Synthesis of High Affinity Inhibitors of Plasmodium falciparum and Plasmodium vivax N-Myristoyltransferases Directed by Ligand Efficiency Dependent Lipophilicity (LELP)

N-Myristoyltransferase (NMT) is an essential eukaryotic enzyme and an attractive drug target in parasitic infections such as malaria. We have previously reported that 2-(3-(piperidin-4-yloxy)benzo[b]thiophen-2-yl)-5-((1,3,5-trimethyl-1H-pyrazol-4-yl)methyl)-1,3,4-oxadiazole (34c) is a high affinity inhibitor of both Plasmodium falciparum and P. vivax NMT and displays activity in vivo against a rodent malaria model. Here we describe the discovery of 34c through optimization of a previously described series. Development, guided by targeting a ligand efficiency dependent lipophilicity (LELP) score of less than 10, yielded a 100-fold increase in enzyme affinity and a 100-fold drop in lipophilicity with the addition of only two heavy atoms. 34c was found to be equipotent on chloroquine-sensitive and -resistant cell lines and on both blood and liver stage forms of the parasite. These data further validate NMT as an exciting drug target in malaria and support 34c as an attractive tool for further optimization