白炭黑胎面胶的新一代硅烷偶联剂

填充白炭黑的低滚动阻力轮胎的开发不断获得新进展。与填充普通炭黑的轮胎相比，白炭黑轮胎不仅降低了油耗，而且具有优异的牵引性能和与后者相当的磨耗寿命。高分散性白炭黑和多硫化双-烷氧基硅烷的发展使高填充白炭黑轮胎商品化获得重大突破。炭黑胶料和白炭黑-硅烷胶料的能耗散机理差异很大，     

Ceramic fibrous monolithic structures

High-strength ceramic fibers and composite structures that contain them are generally expensive. In a lower-cost approach for fabricating fibrous composites, reinforcing fiber-like cells that are distinct from a continuous matrix phase called the cell boundary can be formed in situ from powders. Structures can be constructed by assembly and consolidation of filaments that consist of the cell phase and its surrounding cell boundary.

Fabrication of ceramic fibrous monoliths (FMs) is reviewed and mechanical properties of the most widely studied FMs are discussed. Those based on Si₃N₄ cells within a BN cell boundary have achieved the best overall properties and uniformity of manufacture, but degrade severely at high temperatures in oxidizing environments. Those based on oxides are more stable, but are substantially weaker. Assessment of the future of FMs is offered, including cost reduction, fabrication practice, property improvement, and formation of complex structures.     

Regulation of Trafficking and Signaling of the High Affinity IgE Receptor by FcεRIβ and the Potential Impact of FcεRIβ Splicing in Allergic Inflammation

Mast cells are tissue-resident immune cells that function in both innate and adaptive immunity through the release of both preformed granule-stored mediators, and newly generated proinflammatory mediators that contribute to the generation of both the early and late phases of the allergic inflammatory response. Although mast cells can be activated by a vast array of mediators to contribute to homeostasis and pathophysiology in diverse settings and contexts, in this review, we will focus on the canonical setting of IgE-mediated activation and allergic inflammation. IgE-dependent activation of mast cells occurs through the high affinity IgE receptor, FcεRI, which is a multimeric receptor complex that, once crosslinked by antigen, triggers a cascade of signaling to generate a robust response in mast cells. Here, we discuss FcεRI structure and function, and describe established and emerging roles of the β subunit of FcεRI (FcεRIβ) in regulating mast cell function and FcεRI trafficking and signaling. We discuss current approaches to target IgE and FcεRI signaling and emerging approaches that could target FcεRIβ specifically. We examine how alternative splicing of FcεRIβ alters protein function and how manipulation of splicing could be employed as a therapeutic approach. Targeting FcεRI directly and/or IgE binding to FcεRI are promising approaches to therapeutics for allergic inflammation. The characteristic role of FcεRIβ in both trafficking and signaling of the FcεRI receptor complex, the specificity to IgE-mediated activation pathways, and the preferential expression in mast cells and basophils, makes FcεRIβ an excellent, but challenging, candidate for therapeutic strategies in allergy and asthma, if targeting can be realized.     

A biologically inspired active compliant joint using local positive velocity feedback (LPVF).

Starting from studies which revealed that positive feedback is found in the control system for walking in arthropods, we have constructed a new positive feedback driven joint that can be used for solving compliant motion tasks. We propose two different joint constructions each of which shows passive compliance. Based on these joints we introduce three different local positive velocity feedback (LPVF) controllers and discuss their properties in the context of motion generation in closed kinematic chains. The third circuit named undelayed dLPVF is used for the control of a compliant planar manipulator which turns a crank. Our concept is of highly decentralized nature and follows the idea of embodiment. In our case this means that a process which is controlled by LPVF controllers reveals its nature when the controllers interact with this process.     

Elastoplastic BIE analysis of cracked plates and related problems. Part 2: Numerical results

Part 1 of this paper reports on the formulation of an advanced boundary—integral equation model for fracture mechanics analysis of cracked plates, subject to elastoplastic behaviour or other, related body force problems. The basis of this formulation contrasts with other BIE elastoplastic formulations in the use of the Green's function for an infinite plane containing a stress free crack. This Green's function formulation assures that the total elastic strain field for the crack problem is accurately imbedded in the numerical model. The second part of this paper reports on the numerical implementation of this algorithm, as currently developed. The anelastic strain field (residual strains, thermal strains, plastic strains, etc.) is approximated as piecewise constant, while the boundary data is modelled with linear interpolations. An iteration solution scheme is adopted which eliminates the need for recalculation of the BIE matrices. The stability and accuracy of the algorithm are demonstrated for an uncracked, notch geometry, and comparison to finite element results is made for the centre-cracked panel. The data shows that even the crude plastic strain model applied is capable of excellent resolution of crack tip plastic behaviour.     

Metabolic balance studies in premature infants

Many investigators over the past three decades have successfully conducted traditional metabolic balance studies in efforts to determine the retention rates of key nutrients important to the optimal growth of preterm infants. Differences in methodologies discussed in this review may explain the inconsistent results of balance studies reported for some nutrients, particularly calcium. These methodologic differences include (1) variability in nutrient intake and nutritional course prior to the balance period, (2) differences in the method of stool collection (with and without markers), (3) use of single versus repeated balance periods, and (4) different durations of balance periods. The data presented here suggest that the variability of net fat absorptions among VLBW infants was decreased when an acclimation period of nutrient intake supportive of growth was provided prior to a metabolic balance study. In addition, the use of markers affected the estimates of net calcium absorption but not fat absorption. Additional factors that may influence net calcium absorption and methods for the estimation of calcium absorption in VLBW infants warrant further investigation. This review describes the methods of specimen collection for metabolic balance studies in VLBW preterm infants that demonstrated reproducible data. The recent application of stable isotope methodology to metabolic balance studies can be extremely advantageous in identifying the rates of nutrient absorption versus endogenous secretion in the GI tract.     

Vibrational Energy Transport in Hybrid Ordered/Disordered Nanocomposites: Hybridization and Avoided Crossings of Localized and Delocalized Modes

Vibrational energy transport in disordered media is of fundamental importance to several fields spanning from sustainable energy to biomedicine to thermal management. This work investigates hybrid ordered/disordered nanocomposites that consist of crystalline membranes decorated by regularly patterned disordered regions formed by ion beam irradiation. The presence of the disordered regions results in reduced thermal conductivity, rendering these systems of interest for use as nanostructured thermoelectrics and thermal device components, yet their vibrational properties are not well understood. Here, the mechanism of vibrational transport and the reason underlying the observed reduction is established in detail. The hybrid systems are found to exhibit glass‐crystal duality in vibrational transport. Lattice dynamics reveals substantial hybridization between the localized and delocalized modes, which induces avoided crossings and harmonic broadening in the dispersion. Allen/Feldman theory shows that the hybridization and avoided crossings are the dominant drivers of the reduction. Anharmonic scattering is also enhanced in the patterned nanocomposites, further contributing to the reduction. The systems exhibit features reminiscent of both nanophononic materials and locally resonant nanophononic metamaterials, but operate in a manner distinct to both. These findings indicate that such “patterned disorder” can be a promising strategy to tailor vibrational transport through hybrid nanostructures.     

A simplified MMC model for the control of an arm with redundant degrees of freedom

The paper proposes a model for the control of a multisegmented arm with redundant degrees of freedom. On the basis of an earlier model, the so-called MMC net, a simplified version is proposed here which has several advantages. First, it can easily be scaled up for the 3D case. Second, for the linear version a complete convergence proof is possible. Third, the properties of the earlier model are unchanged, namely versatile control of the redundant system, immediate change from direct kinematics to inverse kinematics or any mixed control task, as well as robustness against singularities.