Energy Dissipation in Shape Memory Alloy Devices

A way of reasoning to reduce the response of a structural system under dynamic excitation is to think in terms of energy dissipation via plastic deformation devices. The concept of recoverable plastic deformation opens the way to the application of smart materials and, in particular, of shape memory alloys (SMAs). The characterization of the TiNi alloy structural component, with a complete definition of its mechanical properties and assembling features, is discussed.     

Near-recursive optical flow from weighted image differences.

This correspondence derives a formal link between temporally weighted frame differences, or disturbance fields, which carry limited information suitable for motion detection, and the optic flow (OF), which carries richer information on local image motion. We use this link to derive a novel, simple, near-recursive optic flow algorithm based on a recursive-filter formulation. Most quantities involved are computed recursively, using only data from the current and previous frame. We can limit expensive OF calculations to pixels where motion magnitude is sufficiently high using image differences which the algorithm computes anyway. Experimental results with well-known synthetic, ground-truthed test sequences and standard performance metrics indicate good quantitative performance. Tests with real sequences suggest similar or better performance than a well-known, similar algorithm due to Lucas and Kanade (LK).     

A Knowledge-Based System for Seismic Vulnerability Assessment of Masonry Buildings

Abstract: A specific class of structures, masonary, is considered. For its analysis a great expertise is available. The 'state of health' of a single existing building is assissed by an expert system which incorporates this expertise. The paper illustrates a knowledge-based expert system for the seismic vulneraility assesment of masonry buildings.     

Parallel Patterns for Window-Based Stateful Operators on Data Streams: An Algorithmic Skeleton Approach

The topic of Data Stream Processing is a recent and highly active research area dealing with the in-memory, tuple-by-tuple analysis of streaming data. Continuous queries typically consume huge volumes of data received at a great velocity. Solutions that persistently store all the input tuples and then perform off-line computation are impractical. Rather, queries must be executed continuously as data cross the streams. The goal of this paper is to present parallel patterns for window-based stateful operators, which are the most representative class of stateful data stream operators. Parallel patterns are presented “à la” Algorithmic Skeleton, by explaining the rationale of each pattern, the preconditions to safely apply it, and the outcome in terms of throughput, latency and memory consumption. The patterns have been implemented in the \(\mathtt {FastFlow}\) framework targeting off-the-shelf multicores. To the best of our knowledge this is the first time that a similar effort to merge the Data Stream Processing domain and the field of Structured Parallelism has been made.     

New Glass–Ceramic Inclusion Pigment

Recently, the traditional ceramic industry has demonstrated increased interest in obtaining inclusion pigments to stabilize unstable chromophores, such as hematite or cadmium sulfoselenide, at firing temperature and in studying the actions of molten glasses. This present work focuses on a new method for synthesizing hematite–zircon inclusion pigments from an unconventional mixture of precursors. For this purpose, a glassy composition that belongs to the LiO₂–ZrO₂–SiO₂ system and that crystallizes into zircon during the calcination step has been chosen.     

Rh(1%)@CexZr1−xO2–Al2O3 nanocomposites: Active and stable catalysts for ethanol steam reforming

Rh(1%)@Ce_xZr_1−xO₂–Al₂O₃ nanocomposites have been investigated as active and thermally stable catalysts for ethanol steam reforming. Preformed Rh nanoparticles have been efficiently protected from deactivation/sintering by a porous layer of nanocomposite oxides. Chemisorption and activity data confirm the good accessibility of the metal phase to the reaction mixture. No appreciable deactivation is observed after 160 h of reaction at 873 K. The ceria–zirconia mixed oxides favour reforming reactions, reduce coke formation and facilitate its removal. The alumina component is important to stabilize the ceria–zirconia mixed oxides, preventing their sintering.     

Calibration of the load enhancement factors

This paper presents a calibration procedure capable of deriving the load enhancement factors from fully probabilistic calculations, to apply to the design of a wide range of types of structure. For this purpose the selection of a target reliability level and the load combination treatment are discussed first. Then the policy for estimating the load partial safety factors is illustrated. Under suitable assumptions, required to perform numerical computations, the calibration problem is formulated as a linear programming problem. Finally the numerical values of the enhancement factors are determined with reference to the more meaningful combinations of structural self weight, imposed dead load, wind action and snow load.     

Inherent variability of an experimental crack growth curve

A statistical data analysis method is applied to a sample of crack growth curves collected by the authors. Details on the experimental environment are provided and the resulting sample is illustrated. The statistical estimates of the model parameters are compared with the analytical assessment made possible by an approximate analytical framework.     

Aggregation-Enhanced Photoluminescence and Photoacoustics of Atomically Precise Gold Nanoclusters in Lipid Nanodiscs (NANO2)

The authors designed a structurally stable nano-in-nano (NANO²) system highly capable of bioimaging via an aggregation-enhanced NIR excited emission and photoacoustic response achieved based on atomically precise gold nanoclusters protected by linear thiolated ligands [Au₂₅(SC_nH_2n+1)₁₈, n  = 4–16] encapsulated in discoidal phospholipid bicelles through a one-pot synthesis. The detailed morphological characterization of NANO² is conducted using cryogenic transmission electron microscopy, small/wide angle X-ray scattering with the support of molecular dynamics simulations, providing information on the location of Au nanoclusters in NANO². The photoluminescence observed for NANO² is 20–60 times more intense than that of the free Au nanoclusters, with both excitation and emission wavelengths in the near-infrared range, and the photoacoustic signal is more than tripled. The authors attribute this newly discovered aggregation-enhanced photoluminescence and photoacoustic signals to the restriction of intramolecular motion of the clusters’ ligands. With the advantages of biocompatibility and high cellular uptake, NANO² is potentially applicable for both in vitro and in vivo imaging, as the authors demonstrate with NIR excited emission from in vitro A549 human lung and the KB human cervical cancer cells.