An experimental study of failure and softening in sand under three-dimensional stress condition

This paper describes an experimental study of failure and softening behaviour in dense Toyoura sand. A true triaxial apparatus equipped with three pairs of rigid loading platens is used to test sand sample under three-dimensional stress condition. The testing results demonstrate that the rigid boundary around the sand samples cannot prevent formation of shear localization. Shear localization are observed to emerge in the hardening or the softening regime in the loading depending on the magnitude of intermediate principal stress. Uniform deformation for the whole strain range is obtained only in triaxial compression tests. The peak stress state obtained from tests of sand samples of the same initial density can be described with good approximation by the Matsuoka–Nakai criterion.     

Detection of shock-wave-induced internal stresses in Cu-Al-Ni shape memory alloy by means of acoustic technique

1. The present results indicate that the stress-induced β₁→γ₁′ martensitic transformation occurs for an impact duration of 2 × 10⁻⁶ s. This time interval appears to be sufficient also for the subsequent deformation of the γ₁′ martensitic phase to occur.2. A structure memory effect has been found: Cu-Al-Ni austenitic crystals, shock-loaded at room temperature to induce γ₁′–martensite, recall during subsequent temperature-induced martensitic transformation the martensitic variant structure (elastic properties) formed under the shock loading.3. Elastic properties of quenched β₁′ and γ₁′ crystals of the Cu-Al-Ni system are extremely sensitive to the shock-wave loading. Mechanisms of these effects, as well as of the structure memory effect, include the generation of internal stresses due to the high elastic anisotropy of the martensitic phases. These internal stresses either change the distribution of martensitic variants or govern the formation of the martensitic variant structure during the temperature-induced martensitic transformation. The generation of high internal stresses by impact loading of the β₁′ martensitic phase is also detected by several anelastic phenomena.4. In contrast to elastic and anelastic properties, transformation temperatures are insensitive to the impact loading, pointing to the difference of structural elements responsible for the anelastic effects and for the interval and hysteresis of the thermoelastic martensitic transformation.     

Selective emitters in Si by single step rapid thermal diffusion forphotovoltaic devices

Selective phosphorous diffusion is performed in Si to simultaneously form shallow n⁺p junctions of different depths in the submicron range by rapid thermal annealing (RTA). Low temperature (400°C) atmospheric pressure chemical vapor deposited (APCVD) phosphosilicate glass (PSG) is used as diffusion source. A wide range of n⁺p junctions could be tailored with the same thermal budget by changing only the APCVD-PSG composition. This allows the formation of selectively diffused emitters in different regions of the wafer in one RTA step. 10 cm×10 cm Cz-Si selective emitter photovoltaic (PV) devices are fabricated this way with high energy conversion efficiencies in the range of 17% to 18%     

Capacity of full frame DCT image watermarks

The evaluation of the number of bits that can be hidden within an image through digital watermarking is a crucial topic, which has been addressed only for additive watermarks. The evaluation of watermark capacity is very important because it allows to put a theoretical upper bound on the amount of information that can be hidden into an image by a given watermarking procedure, regardless of the watermark extraction technique. It is the purpose of this work to suggest a methodology for the evaluation of the watermark capacity in a nonadditive, non-Gaussian framework, and to discuss the results we obtained by applying it to a set of standard images.     

The effects of drying, aging and curing on an organic - inorganic coating

The effects of drying, aging and curing on an organic - inorganic coating deposited on float glass substrates were analyzed. Methyltrimethoxysilane was used to immobilize parts of the network connections and silica particles were used as seeds for the nucleation of the gel structure. The coating was produced under acidic conditions to enhance the hydrolysis reaction. The coatings were deposited using a spin-coating technique. The dependence of the elastic modulus, hardness, fracture toughness and residual stress obtained by indentation on the preparation conditions is reported. In addition results obtained by X-ray diffraction (XRD), Atomic Force Microscopy (AFM), X-ray Photon Spectroscopy (XPS) and Infrared-Spectroscopy are analyzed.     

Router design for nano‐communication using actin quantum cellular automata

Logic expressions can be designed from actin filaments. It is a protein that makes the cellular structure and plays an important role in intracellular communication. Nano communication technique has been established using actin cellular automata. Among several rules, (1, 30) and (4, 27) rules have been used to design 2 to 1 multiplexer, 4 to 1 multiplexer, 1 to 2 demultiplexer and 1 to 4 demultiplexer. Router or data selector has been made of using multiplexer and demultiplexer. Three novel circuits such as multiplexer, demultiplexer and nano‐router have been designed using the projected mechanism. The primary focus of this proposed technique is on different designs of the multiplexer, demultiplexer and minimum cell count with minimum time steps. The different router circuits have been simulated with the help of Simulink by which output has been verified for different circuits. Stuck at fault analysis is also done in this study. Device density and power consumption have also been included in this study. A comparative analysis of the different designs of the router provides a better concept of circuit optimisation. Furthermore, this study analyses convenient forthcoming applications in nano‐technology and nano‐bio‐molecular systems involving the proposed parameters.Inspec keywords: cellular automata, demultiplexing equipment, proteins, logic circuits, logic design, telecommunication network routing, nanocommunication (telecommunication), nanoelectronics, multiplexing equipmentOther keywords: nanocommunication technique, actin cellular automata, 2 to 1 multiplexer design, data selector, multiplexer demultiplexer, actin‐based cellular automata, logic circuits, multiplexer cell count, demultiplexer cell count, minimum cell count, minimum time steps, router circuits, circuit optimisation, nanotechnology, nanobiomolecular systems, actin quantum cellular automata, logic expressions, actin filaments, cellular structure, intracellular communication, logic implementation, 4 to 1 multiplexer, 1 to 2 demultiplexer, 1 to 4 demultiplexer, nanorouter design, Simulink, stuck at fault analysis, device density, power consumption     

Toxicological Profile of Plasmonic Nanoparticles in Zebrafish Model

Plasmonic nanoparticles are increasingly employed in several fields, thanks to their unique, promising properties. In particular, these particles exhibit a surface plasmon resonance combined with outstanding absorption and scattering properties. They are also easy to synthesize and functionalize, making them ideal for nanotechnology applications. However, the physicochemical properties of these nanoparticles can make them potentially toxic, even if their bulk metallic forms are almost inert. In this review, we aim to provide a more comprehensive understanding of the potential adverse effects of plasmonic nanoparticles in zebrafish (Danio rerio) during both development and adulthood, focusing our attention on the most common materials used, i.e., gold and silver.     

Well-being and organizational attitudes in alternative employment: The role of contract and job preferences.

This study focuses upon the heterogeneity in the contemporary workforce in relation to well-being and organizational attitudes. This heterogeneity may concern (a) the specific type of contract (permanent full-time vs. alternative arrangements; e.g., permanent part-time, fixed-term, and on-call work), (b) job and contract preferences, or (c) specific combinations of contract type and preferences. The authors argue that working in alternative employment, but also being in a nonpreferred contract or job may imply stress and, hence, strain (i.e., poor well-being). This may lead to withdrawal from the organization (i.e., poor organizational attitudes). A combination of the stressors may strengthen these effects. Analyses of questionnaire data from Sweden collected in 2004 (N = 716) reveal that preferences, particularly preferences for the job and partly also for the contract, were associated with the outcomes. Contract heterogeneity was not informative for well-being, while it was for differences in reported organizational attitudes. Type of employment contract interacted with job and contract preferences: for permanent full-time workers, job preferences displayed stronger associations with well-being and attitudes than for workers in alternative employment. (PsycINFO Database Record (c) 2010 APA, all rights reserved)