Attachment security in very low birth weight infants.

34 infants of very low birth weight (VLBW) and a comparison group of 40 full-term infants were observed in the Strange Situation of M. D. Ainsworth et al (1978) at 14 and 19 mo and observed in the home at 14 mo of age, using E. Waters's (1995) Attachment Q-set. Results indicated that at 14 mo VLBW infants were more likely than the full-term infants to be insecurely attached when rated using the Q-set but not when using the Strange Situation. However, at 19 mo VLBW infants were also more likely than full-term infants to be insecurely attached in the Strange Situation assessment. There were no associations between the Q-set and Strange Situation measures of attachment security. These results are discussed in terms of the social-emotional development of VLBW infants. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Metals and incinerators: The latest regulatory phase

Recent regulations in the United States controlling emissions of metals and halogen acid gases from boilers and industrial furnaces (BIFs) burning regu     

Spatially Configuring Wrinkle Pattern and Multiscale Surface Evolution with Structural Confinement

Surface elastic instabilities, such as wrinkling and creasing, can enable a convenient strategy to impart reversible patterned topography to a surface. Here the classic system of a stiff layer on a soft substrate is focused, which famously produces parallel harmonic wrinkles at modest uniaxial compression that period‐double repeatedly at higher compressions and ultimately evolve into deep folds and creases. By introducing micrometer‐scale planar Bravais lattice holes to spatially pattern the substrate, these instabilities are guided into a wide variety of different patterns, including wrinkling in parallel bands and star shape bands, and radically reduce the threshold compression. The experimental patterns and thresholds are enabled to understand by considering a simple plane‐strain model for the patterned substrate‐deformation, decorated by wrinkling on the stiff surface layer. The experiments also show localized wrinkle‐crease transitions at modest compression, yielding a hierarchical surface with different generations of instability mixed together. By varying the geometrical inputs, control over the stepwise evolution of surface morphologies is demonstrated. These results demonstrate considerable control over both the patterns and threshold of the surface elastic instabilities, and have relevance to many emerging applications of morphing surfaces, including in wearable/flexible electronics, biomedical systems, and optical devices.     

Wearable Soft Technologies for Haptic Sensing and Feedback

Virtual reality (VR) and augmented reality (AR) systems have garnered recent widespread attention due to increased accessibility, functionality, and affordability. These systems sense user inputs and typically provide haptic, audio, and visual feedback to blend interactive virtual environments with the real world for an enhanced or simulated reality experience. With applications ranging from immersive entertainment, to teleoperation, to physical therapy, further development of this technology has the potential for impact across multiple disciplines. However, VR/AR devices still face critical challenges that hinder integration into everyday life and additional applications; namely, the rigid and cumbersome form factor of current technology that is incompatible with the dynamic movements and pliable limbs of the human body. Recent advancements in the field of soft materials are uniquely suited to provide solutions to this challenge. Devices fabricated from flexible and elastic bio-compatible materials have significantly greater compatibility with the human body and could lead to a more natural VR/AR experience. This review reports state-of-the-art experimental studies in soft materials for wearable sensing and haptic feedback in VR/AR applications, explores emerging soft technologies for on-body devices, and identifies current challenges and future opportunities toward seamless integration of the virtual and physical world.     

Going with the Flow: Tunable Flow‐Induced Polymer Mechanochemistry

Mechanical forces can drive chemical transformations in polymers, directing reactions along otherwise inaccessible pathways, providing exciting possibilities for developing smart, responsive materials. The state‐of‐the‐art test for solution‐based polymer mechanochemistry development is ultrasonication. However, this does not accurately model the forces that will be applied during device fabrication using processes such as 3D printing or spray coating. Here, a step is taken toward predictably translating mechanochemistry from molecular design to manufacturing by demonstrating a highly controlled nozzle flow setup in which the shear forces being delivered are precisely tuned. The results show that solvent viscosity, fluid strain rate, and the nature of the breaking bond can be individually studied. Importantly, it is shown that the influence of each is different to that suggested by ultrasonication (altered quantity of chain breakage and critical polymer chain length). Significant development is presented in the understanding of polymer bond breakage during manufacturing flows to help guide design of active components that trigger on demand. Using an anthracene‐based mechanophore, the triggering of a fluorescence turn‐on is demonstrated through careful selection of the flow parameters. This work opens the avenue for programmed chemical transformations during inline manufacturing processes leading to tunable, heterogeneous final products from a single source material.     

A low complexity high efficiency hybrid multiplicative-additive crest factor reduction for OFDM systems

In this paper, we propose a novel technique to reduce the crest factor (CF) in orthogonal frequency division multiplexing systems. It consists of two inverse fast Fourier transform (IFFT) blocks, the input symbols of the first IFFT are the mapped symbols, whereas the input symbols of the second IFFT are the summations of the absolute value of the real part of the outer signal constellation points and zero symbols. First, the output of the two IFFT blocks is partitioned into four subblocks, which are subsequently used to rearrange the subblocks with padding zeros in a specific manner. Then, a new optimization scheme is introduced, in which only a single two-phase sequence and four iterations need to be applied. Numerical analysis shows that the proposed hybrid technique achieves better CF reduction performance with significantly lower complexity and better bit error rate performance than the existing scrambling (multiplicative) and additive CF techniques.     

Is mother nature long oil?

Journal of the American Oil Chemists' Society -     

Effects of La2O3/ZnO Additives on Microstructure And Microwave Dielectric Properties of Zr0.8Sn0.2TiO4 Ceramics

Dielectric ceramics of Zr_0.8Sn_0.2TiO₄ containing La₂O₃ and ZnO as sintering aids were prepared and investigated for microstructure and microwave dielectric properties. Low-level doping with La₂O₃ and ZnO (up to 0.30 wt%) is good for densification and dielectric properties. These additives do not affect the dielectric constant and the temperature coefficient. Dielectric losses increase significantly at additive levels higher than 0.15 wt%. The combined additives La₂O₃ and ZnO act as grain growth enhancers. With 0.15 wt% additives, a ceramic having a dielectric constant, a quality factor, and a temperature coefficient of frequency at 4.2 GHz of 37.6, 12 800, and –2.9 ppm/°C, respectively, was obtained. The quality factor was considerably improved by prolonged sintering.     

An expert system manipulating knowledge to help human learners into virtual environment

This research is situated within the context of the creation of human learning environments using virtual reality. We propose the integration of a generic and adaptable intelligent tutoring system (Pegase). The aim is to instruct the learner, and to assist the instructor. The multi-agent system emits a set of knowledge (actions carried out by the learner, knowledge of the field, etc.) used by an artificial intelligence to make pedagogical decisions. Our study focuses on the representation of knowledge about the environment, and on the adaptable pedagogical agent providing instructive assistance.