496 research outputs found
A modified energyâbased fatigue parameter for short fiber reinforced polymers: Performance analysis with varying thicknesses, load ratios, and fiber orientations
The durability of Short Fibre Reinforced Polymers (SFRPs) is affected by several variables. Accurate unifying fatigue parameters are thus essential for an efficient characterization campaign. This research investigated the fatigue behaviour of a Polyphtalamide PA6T/6I reinforced with 50% of glass ïŹbres. Two thicknesses (1.6 mm and 3 mm), two orientations from the injection moulding direction (0° and 90°) and three load rations (-0.5, 0.1, 0.5) were investigated. A new fatigue parameter, called Alternating Energy Density (AED), was presented; its ability to correlate the fatigue tests results was compared to other known fatigue parameters â cyclic mean strain rate and cyclic creep energy density. All the fatigue parameters were found to be independent of specimen thickness. Furthermore, the prediction of the fatigue lifetime based on AED showed greater accuracy with respect to the other known investigated methods. AED could thus be used for accurate and efficient lifetime prediction of SFRPs
Modelling the static and fatigue behavior of hybrid spot welded-adhesively bonded single lap joints
Using hydrothermal dolomite to constrain the age and genesis of Alpine-type Pb-Zn deposits. Insights from the Gorno district (Lombardy, Italy)
Nickel Phosphides Fabricated through a CodepositionâAnnealing Technique as Low-Cost Electrocatalytic Layers for Efficient Hydrogen Evolution Reaction
Water splitting will be one of the most strategic techniques in the upcoming hydrogen-based economy. In this context, the development of efficient and low-cost Pt-free electrocatalysts is crucial t..
Evidence of hydrothermal fluid flow in a hyperextended rifted margin: the case study of the Err nappe (SE Switzerland)
Analysis of peel and shear strains in cracked lap shear specimens subjected to fatigue loading using digital image correlation
Adhesive bonding presents many advantages, such as efficient manufacturing and improved structural performance [1]. However, in structures subjected to fatigue, cracks might initiate and propagate in joints, leading to in-service failure [2]. Most adhesively bonded joints are subjected to combination of peel and shear loads, so mixed I+II mode loading conditions are present [3]. In this work, Cracked Lap Shear specimens, which feature mixed I+II mode loading conditions, were tested under fatigue loading. During tests, crack growth was monitored using Visual Testing and Digital Image Correlation. With Digital Image Correlation, opening and sliding displacements in the bondline were extracted from the substratesâ displacement fields and compared against a Finite Element Model, revealing a highly strained process zone ahead of the crack tip. Results highlight the usefulness of DIC in capturing the deformation behaviour of adhesive joints under mixed mode loading conditions
Enhancing Logic Synthesis of Switching Lattices by Generalized Shannon Decomposition Methods
In this paper we propose a novel approach to the synthesis of minimal-sized lattices, based on the decomposition of logic functions. Since the decomposition allows to obtain circuits with a smaller area, our idea is to decompose the Boolean functions according to generalizations of the classical Shannon decomposition, then generate the lattices for each component function, and finally implement the original function by a single composed lattice obtained by glueing together appropriately the lattices of the component functions. In particular we study the two decomposition schemes defining the bounded-level logic networks called P-circuits and EXOR-Projected Sums of Products (EP-SOPs). Experimental results show that about 34% of our benchmarks achieve a smaller area when implemented using the P-circuit decomposition for switching lattices, with an average gain of at least 25%, and about 27% of our benchmarks achieve a smaller area when implemented using the EP-SOP decomposition, with an average gain of at least 22%
Syn-rift hydrothermal circulation in the Mesozoic carbonates of the western Adriatic continental palaeomargin (Western Southalpine Domain, NW Italy)
Evidence of hydrothermal activity is reported for the Mesozoic pre- and syn-rift successions of the western Adriatic palaeomargin of the Alpine Tethys, preserved in the Western Southalpine Domain (NW Italy). The products of hydrothermal processes are represented by vein and breccia cements, as well as dolomitization and silicification of the host rocks. In the eastern part of the study area, interpreted as part of the necking zone of the continental margin, Middle Triassic dolostones and Lower Jurassic sediments are crossed by veins and hydrofracturing breccias cemented by saddle dolomite. The precipitation of dolomite cements occurred within the stratigraphic succession close to the sedimentâwater interface. Despite the shallow burial depth, fluid inclusion microthermometry and clumped isotopes show that hydrothermal fluids were relatively hot (80â150°C). In the western part of the study area, interpreted as part of the hyperextended distal zone, a polyphase history of host-rock fracturing is recorded, with at least two generations of veins cemented by calcite, dolomite and quartz. Vein opening and cementation occurred at shallow burial depth around the time of deposition of the syn-rift clastic succession. Fluid inclusion microthermometry on both quartz and dolomite cements indicates a fluid temperature of 90â130°C, again pointing to hydrothermal fluids. Both in Fenera-Sostegno and Montalto Dora areas, O, C and Sr isotope values, coupled with fluid inclusion and clumped isotope data, indicate that hydrothermal fluids derived from seawater interacted with crustal rocks during hydrothermal circulation. Stratigraphic and petrographic evidence, and UâPb dating of dolomitized clasts within syn-rift sediments, document that hydrothermal fluids circulated through sediments from the latest Triassic to the Toarcian, corresponding to the entire syn-rift evolution of the western portion of the Adriatic palaeomargin. The documented hydrothermal processes are temporally correlated with regional-scale thermal events that took place in the same time interval at deeper crustal levels
Prevalence of vitamin B12 depletion and deficiency in Liechtenstein
Abstract Objective Data about vitamin B12 (B12) deficiency in the general population are scarce. The present study was performed to determine the prevalence of B12 deficiency in the general population of the Principality of Liechtenstein, as well as to identify sub-populations potentially at high risk. Design Retrospective study. Setting Ambulatory setting, population of the Principality of Liechtenstein. Subjects Seven thousand four hundred and twenty-four patients seeking medical attention whose serum samples were referred for routine work-up in an ambulatory setting were consecutively enrolled. Serum total B12 was determined in all patients in this cohort. In addition, for a subgroup of 1328 patients, serum holotranscobalamin was also measured. Prevalence of B12 deficiency was calculated. Further, multivariate logistical regression models were applied to identify covariates independently associated with B12 deficiency and depletion. Results Nearly 8 % of the general population was suffering from either B12 depletion or deficiency. The ratio between B12 depletion and deficiency was 2:1 for all age ranges. Pathological changes were detected predominantly in older people. Female gender was a significant predictor of B12 depletion. In the cohort, nearly 40 % exhibited either depletion or deficiency of B12. Conclusions B12 depletion and deficiency are common in Liechtenstein, a Central European country. The measurement of biochemical markers represents a cost-efficient and valid assessment of the B12 state. When a deficiency of B12 is diagnosed at an early stage, many cases can be treated or prevented, with beneficial effects on individual outcomes and subsequent potential reductions in health-care cost
Logic synthesis and testing techniques for switching nano-crossbar arrays
Beyond CMOS, new technologies are emerging to extend electronic systems with features unavailable to silicon-based devices. Emerging technologies provide new logic and interconnection structures for computation, storage and communication that may require new design paradigms, and therefore trigger the development of a new generation of design automation tools. In the last decade, several emerging technologies have been proposed and the time has come for studying new ad-hoc techniques and tools for logic synthesis, physical design and testing. The main goal of this project is developing a complete synthesis and optimization methodology for switching nano-crossbar arrays that leads to the design and construction of an emerging nanocomputer. New models for diode, FET, and four-terminal switch based nanoarrays are developed. The proposed methodology implements logic, arithmetic, and memory elements by considering performance parameters such as area, delay, power dissipation, and reliability. With combination of logic, arithmetic, and memory elements a synchronous state machine (SSM), representation of a computer, is realized. The proposed methodology targets variety of emerging technologies including nanowire/nanotube crossbar arrays, magnetic switch-based structures, and crossbar memories. The results of this project will be a foundation of nano-crossbar based circuit design techniques and greatly contribute to the construction of emerging computers beyond CMOS. The topic of this project can be considered under the research area of Ăą\u80\u9cEmerging Computing ModelsĂą\u80\u9d or Ăą\u80\u9cComputational NanoelectronicsĂą\u80\u9d, more specifically the design, modeling, and simulation of new nanoscale switches beyond CMOS
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