Experimental investigation of a timber-concrete floor panel system with a hybrid glass fibre reinforced polymer-timber corrugated core

Hybrid timber-concrete (HTC) floor systems are well-suited for prefabricated construction and so have seen widespread use in modern sustainable buildings. This paper investigates a novel extension to such systems by introducing a corrugated core between tensile timber and compressive concrete layers. This new ‘HTCC’ floor panel system is hypothesised to have an increased weight-specific flexural capacity relative to HTC systems, by reducing the volume of concrete below the panel neutral axis without decreasing flexural capacity. This paper experimentally investigates the flexural performance of the new system, acting in two configurations: with core orientation parallel to the span for maximum longitudinal one-way spanning capacity; and with core orientation transverse to the span for generation of a novel transverse spanning capacity. In total, eight HTCC floor panels were prepared and tested, with the flexural capacities and critical failure modes analysed for each. Effects of different core geometries, shear force transfer methods, and manifested composite action are also closely studied. Longitudinal specimens achieved the best composite action and correspondingly the highest panel performance, with a 73% ultimate moment carrying efficiency and an 85% stiffness efficiency at SLS, compared to an idealised HTC section with full composite action

Use of DNA technology in forensic dentistry

The established importance of Forensic Dentistry for human identification, mainly when there is little remaining material to perform such identification (e.g., in fires, explosions, decomposing bodies or skeletonized bodies), has led dentists working with forensic investigation to become more familiar with the new molecular biology techniques. The currently available DNA tests have high reliability and are accepted as legal proofs in courts. This article presents a literature review referring to the main studies on Forensic Dentistry that involve the use of DNA for human identification, and makes an overview of the evolution of this technology in the last years, highlighting the importance of molecular biology in forensic sciences

Breast cancer polygenic risk score and contralateral breast cancer risk

Previous research has shown that polygenic risk scores (PRSs) can be used to stratify women according to their risk of developing primary invasive breast cancer. This study aimed to evaluate the association between a recently validated PRS of 313 germline variants (PRS313) and contralateral breast cancer (CBC) risk. We included 56,068 women of European ancestry diagnosed with first invasive breast cancer from 1990 onward with follow-up from the Breast Cancer Association Consortium. Metachronous CBC risk (N = 1,027) according to the distribution of PRS313 was quantified using Cox regression analyses. We assessed PRS313 interaction with age at first diagnosis, family history, morphology, ER status, PR status, and HER2 status, and (neo)adjuvant therapy. In studies of Asian women, with limited follow-up, CBC risk associated with PRS313 was assessed using logistic regression for 340 women with CBC compared with 12,133 women with unilateral breast cancer. Higher PRS313 was associated with increased CBC risk: hazard ratio per standard deviation (SD) = 1.25 (95%CI = 1.18–1.33) for Europeans, and an OR per SD = 1.15 (95%CI = 1.02–1.29) for Asians. The absolute lifetime risks of CBC, accounting for death as competing risk, were 12.4% for European women at the 10th percentile and 20.5% at the 90th percentile of PRS313. We found no evidence of confounding by or interaction with individual characteristics, characteristics of the primary tumor, or treatment. The C-index for the PRS313 alone was 0.563 (95%CI = 0.547–0.586). In conclusion, PRS313 is an independent factor associated with CBC risk and can be incorporated into CBC risk prediction models to help improve stratification and optimize surveillance and treatment strategies

Polygenic Risk Scores for Prediction of Breast Cancer and Breast Cancer Subtypes.

Stratification of women according to their risk of breast cancer based on polygenic risk scores (PRSs) could improve screening and prevention strategies. Our aim was to develop PRSs, optimized for prediction of estrogen receptor (ER)-specific disease, from the largest available genome-wide association dataset and to empirically validate the PRSs in prospective studies. The development dataset comprised 94,075 case subjects and 75,017 control subjects of European ancestry from 69 studies, divided into training and validation sets. Samples were genotyped using genome-wide arrays, and single-nucleotide polymorphisms (SNPs) were selected by stepwise regression or lasso penalized regression. The best performing PRSs were validated in an independent test set comprising 11,428 case subjects and 18,323 control subjects from 10 prospective studies and 190,040 women from UK Biobank (3,215 incident breast cancers). For the best PRSs (313 SNPs), the odds ratio for overall disease per 1 standard deviation in ten prospective studies was 1.61 (95%CI: 1.57-1.65) with area under receiver-operator curve (AUC) = 0.630 (95%CI: 0.628-0.651). The lifetime risk of overall breast cancer in the top centile of the PRSs was 32.6%. Compared with women in the middle quintile, those in the highest 1% of risk had 4.37- and 2.78-fold risks, and those in the lowest 1% of risk had 0.16- and 0.27-fold risks, of developing ER-positive and ER-negative disease, respectively. Goodness-of-fit tests indicated that this PRS was well calibrated and predicts disease risk accurately in the tails of the distribution. This PRS is a powerful and reliable predictor of breast cancer risk that may improve breast cancer prevention programs

Design and digital fabrication of folded sandwich structures

This paper presents a design-to-fabrication process for folded sandwich structures that comprises surface to pattern conversion, manufacture rationalisation, and integral connection superposition. Folded sandwich structures are shown to possess a tessellated, origami-like structural form in which building component parameters are inherently dependant upon building surface parameters. Structural forms can therefore be designed with a minimum number of unique parts and with simultaneous consideration of surface and component constraints. The design-to-fabrication process is demonstrated for the Plate House, a cardboard shelter designed to meet transitional shelter packaged and deployed volume requirements. Additional prototypes are presented to demonstrate an extended set of parametric edge connection details for the production of cardboard, plywood, or steel folded sandwich structures. Prototypes are also presented to demonstrate how the method can be applied generally for the digital fabrication of developable 3D surfaces with a known crease pattern. </p

La ragazza con l’orecchino di perla

A modified planar foldcore geometry was developed by introducing sub-folds into a standard foldcore pattern. It was demonstrated using numerical simulation that the new geometry, deemed the indented foldcore, successfully triggered a high-order travelling hinge line failure mode. This was found to have a much higher and more uniform energy absorption than the plate buckling failure mode seen in a standard foldcore structure. A numerical analysis also established optimum standard and indented geometries with maximum energy absorption. Prototypes were constructed to experimentally validate numerical findings. Prototypes with no visible geometric imperfections displayed the travelling hinge line behaviour as predicted. Prototypes with visibly-buckled plates showed no change in failure mode compared to a standard foldcore, confirming numerical findings that the travelling hinge line failure mode is highly sensitive to geometric imperfections.</p

The behaviour of curved-crease foldcores under low-velocity impact loads

The primary aim of this paper was to manufacture aluminium curved-crease foldcores and assess their behaviour under quasi-static compressive loads, relative to existing straight-crease foldcores and a honeycomb cores. Four foldcore types, standard, indented, and two curved-crease foldcore tessellations, were constructed with comparable density and height to a commercial honeycomb core. An experimental and numerical study of foldcore performance under quasi-static crush loads showed that all foldcore types were highly sensitive to geometric imperfections, and that curved-crease foldcores had significantly higher energy-absorption capability than straight-crease foldcores. Validated numerical methods were used in a comprehensive parametric study on curved-crease foldcore geometry, with two main findings. First, it was seen that altering the curved-crease foldcore tessellation did not provide significant energy-absorption capability beyond that achievable with direct changes to the core aspect ratio. Second, an optimum configuration of the curved-crease foldcore was found which appeared to offer a comparable out-of-plane strength, energy-absorption under quasi-static compressive loads, and stiffness to a honeycomb core. A brief numerical investigation into low-velocity impact loading showed that curved-crease foldcores were the only foldcore type that saw a substantial inertial strengthening under dynamic loading, although not to as large an extent as honeycomb.</p

Miura-Base rigid origami: parametrizations of curved-crease geometries

Curved-crease (CC) origami differs from prismatic, or straight-crease origami, in that the folded surface of the pattern is bent during the folding process. Limited studies on the mechanical performance of such geometries have been conducted, in part because of the difficulty in parametrizing and modeling the pattern geometry. This paper presents a new method for generating and parametrizing rigid-foldable, CC geometries from Miura-derivative prismatic base patterns. The two stages of the method, the ellipse creation stage and rigid subdivision stage, are first demonstrated on a Miura-base pattern to generate a CC Miura pattern. It is shown that a single additional parameter to that required for the straight-crease pattern is sufficient to completely define the CC variant. The process is then applied to tapered Miura, Arc, Arc-Miura, and piecewise patterns to generate CC variants of each. All parametrizations are validated by comparison with physical prototypes and compiled into a matlab Toolbox for subsequent work

G. G. Filippi, Mrtyu: Concept of Death in Indian Traditions. New Delhi: D. K. Printworld (P)Ltd., 1996.

Curved-crease (CC) origami differs from prismatic, or straight-crease origami, in that the folded surface of the pattern is bent during the folding process. Limited studies on the mechanical performance of such geometries have been conducted, in part because of the difficulty in parametrizing and modeling the pattern geometry. This paper presents a new method for generating and parametrizing rigid-foldable, CC geometries from Miura-derivative prismatic base patterns. The two stages of the method, the ellipse creation stage and rigid subdivision stage, are first demonstrated on a Miura-base pattern to generate a CC Miura pattern. It is shown that a single additional parameter to that required for the straight-crease pattern is sufficient to completely define the CC variant. The process is then applied to tapered Miura, Arc, Arc-Miura, and piecewise patterns to generate CC variants of each. All parametrizations are validated by comparison with physical prototypes and compiled into a matlab Toolbox for subsequent work

Geometric assembly of rigid-foldable morphing sandwich structures

Morphing plate-based sandwich mechanisms consist of three layers: an inner core designed to achieve a particular deployed geometric envelope and two outer faces designed to preserve core rigid-foldability from flat-folded to a deployed sandwich form. This paper examines rigid-foldable morphing sandwich mechanisms based on the Miura rigid origami pattern. An alternative mechanism is developed that has improved stability and locking capability compared with the existing mechanism reported previously. These improvements are demonstrated with steel prototypes. The alternative mechanism is then extended to form a family of new morphing sandwich structures, including a fan-shaped mechanism, and single-curved cylindrical and conical mechanisms. Each are derived by substituting the base Miura core pattern with a Miura-derivative pattern, and attaching faces that have compatible rigid-foldability and avoid self-intersection during deployment. Morphing mechanisms and geometric derivations are validated with physical prototypes. </p