Examining for possible non-thermal effects during heating in a microwave oven

The assumption that the thermal effect (heating) is the sole factor that should be considered when a microwave source is applied has been debated by many reports, often claiming that athermal (non-thermal) effects exist as well. Such effects are claimed to change the chemical, biochemical, or the physical behaviour of some systems while the temperature and all other parameters remain unaltered. The possibility of an athermal effect was tested in a number of chemical, biological and physical systems in a very well controlled, high radiation intensity system (2.45 GHz, up to 1000 W/kg, with continuous radiation up to 48 h). The systems that were tested included: Maillard reaction, protein denaturation and polymer solubility, mutagenesis of bacteria, mutarotation equilibrium of α/β-d-glucose, and saturation solubility of NaCl. All data failed to show any significant athermal effects. The results of this study are in contrast to what has been previously reported for some of the tested systems.     

Viscoplastic response and modeling of asphalt-aggregate mixes

The strain response of asphalt-aggregate mixes to applied stresses is decomposed additively into a viscoelastic part and a viscoplastic part. The paper focuses on the response and modeling of the viscoplastic component; it includes the development of a multiaxial constitutive formulation that is capable of generating: (i) strain hardening when the loading is applied in one direction; (ii) strain softening immediately after stress reversals; (iii) volumetric changes under uniaxial conditions or isotropic conditions, or both; and (iv) directional non-symmetry. In order to investigate the model’s capabilities, four tests were performed sequentially on one asphalt sample. The tests were limited to pre-peak conditions and one temperature and consisted of creep and recovery sequences in uniaxial tension, uniaxial compression, isotropic compression and uniaxial tension-compression. Analysis of the results showed that the new theory, once calibrated, was able to adequately reproduce the viscoplastic strain component; its forecastability, however, was found limited.     

LiMoSense: live monitoring in dynamic sensor networks

We present LiMoSense, a fault-tolerant live monitoring algorithm for dynamic sensor networks. This is the first asynchronous robust average aggregation algorithm that performs live monitoring, i.e., it constantly obtains a timely and accurate picture of dynamically changing data. LiMoSense uses gossip to dynamically track and aggregate a large collection of ever-changing sensor reads. It overcomes message loss, node failures and recoveries, and dynamic network topology changes. The algorithm uses a novel technique to bound variable size. We present the algorithm and formally prove its correctness. We use simulations to illustrate its ability to quickly react to changes of both the network topology and the sensor reads, and to provide accurate information.     

BCC vs. HCP—The Effect of Crystal Symmetry on the High Temperature Mobility of Solid 4He

We report results of torsional oscillator (TO) experiments on solid ⁴He at temperatures above 1?K. We have previously found that single crystals, once disordered, show some mobility (decoupled mass) even at these rather high temperatures. The decoupled mass fraction with single crystals is typically 20–30%. In the present work we performed similar measurements on polycrystalline solid samples. The decoupled mass with polycrystals is much smaller, ～1%, similar to what is observed by other groups. In particular, we compared the properties of samples grown with the TO’s rotation axis at different orientations with respect to gravity. We found that the decoupled mass fraction of bcc samples is independent of the angle between the rotation axis and gravity. In contrast, hcp samples showed a significant difference in the fraction of decoupled mass as the angle between the rotation axis and gravity was varied between zero and 85 degrees. Dislocation dynamics in the solid offers one possible explanation of this anisotropy.     

Exciton-plasmon interactions in quantum dot-gold nanoparticle structures

We present a self-assembly method to construct CdSe/ZnS quantum dot-gold nanoparticle complexes. This method allows us to form complexes with relatively good control of the composition and structure that can be used for detailed study of the exciton-plasmon interactions. We determine the contribution of the polarization-dependent near-field enhancement, which may enhance the absorption by nearly two orders of magnitude and that of the exciton coupling to plasmon modes, which modifies the exciton decay rate.     

Structural characterization of amylose-long chain fatty acid complexes produced via the acidification method

Amylose molecular inclusion complexes, or V-amylose, have been studied as a possible nano-sized delivery system for unsaturated fatty acids. This study aimed to study three different structural levels of V-amylose produced via an acidification method. Molecular attributes were studied using XRD, DSC and ¹³C CP/MAS NMR, nanostructures using SAXS and AFM, and the microscopic level by SEM and AFM. ¹³C labeled fatty acids revealed head groups were entrapped in both COO- and COOH forms. SAXS data, showed that conjugated linoleic acid yield particles with the highest values for parameters like average crystalline lamellar thickness (φ = 0.46) and characteristic particle dimension (R_g = 1011). AFM revealed surface roughness increases from 7.72 ± 4.34 nm to 11.54 ± 6.05 nm during the formation of V-amylose. The insights described contribute to the understanding of V-amylose structure and help establish a model for V-amylose structure which may prospectively be used in the fabrication of a novel delivery system.     

Ordered carbon nanotubes for optical power limiting devices

The electrospinning (ES) process was used to fabricate composite nanofibers (NFs) of poly(methyl methacrylate), PMMA, with embedded multiwalled carbon nanotubes (MWNTs) from a solution of PMMA in N,N-dimethylformamide (DMF) with homogenously dispersed MWNTs. Using both the sinklike and the elongation flows in the electrospinning process, we aligned the carbon nanotubes (CNTs) along the fiber axis. The NFs were subsequently deposited in an aligned manner on a glass surface using the electrostatic lens created by the edge of a rotating wheel collector. Semitransparent optical power limiter (OPL) films (~50% transmittance) were fabricated using an optically compatible polymeric resin infiltrated into the collected NFs. These comprised oriented NFs with different carbon nanotube loadings and film thicknesses. The OPLs exhibited high limiting abilities, with a limiting threshold of 1.5 J/cm(2) at about 50% linear transmittance. Some degree of polarization was also achieved, but significantly lower than expected because of the NF orientation.     

Speeding and the time-saving bias: How drivers’ estimations of time saved in higher speed affects their choice of speed

According to the time-saving bias, drivers overestimate the time saved when increasing from an already relatively high speed and underestimate the time saved when increasing from a relatively low speed. This study examined the effect the time-saving bias may have on drivers’ choice of speed using hypothetical situations. Drivers were presented with a situation involving acceleration from a relatively low speed in order to arrive at a destination on time and were asked to estimate the time that could be saved by increasing to higher speeds. Drivers also estimated the speed required for arriving on time, the speed they would personally choose and the speed they believed other drivers would opt for in such a situation. Results showed that drivers indeed underestimated the time that could be saved by increasing from a low speed. In addition, drivers who showed a high time-saving bias (above median) indicated notably higher speeds in all three categories above and their indicated speeds exceeded the speed limit more frequently. These findings suggest that the time-saving bias may help explain why drivers, in some situations, prefer an overly high speed and violate the legal speed limit.     

Prime Time Commemoration: An Analysis of Television Broadcasts on Israel's Memorial Day for the Holocaust and the Heroism

This study explores the ways in which commercial media perceive and manifest their public mnemonic role. It does so via an exploration of the "memory menu"—the contents and flow of programming—offered by Channel 2, Israel's leading commercial television channel, on the eve of the country's Memorial Day for the Holocaust and the Heroism (MDHH), in which the airing of commercials is banned. In order to do so, the study incorporates a multilevel analysis that probes the structure of entire broadcasting evenings as well as the narrative building blocks that constitute each item. The study investigates the ways in which commercial media outlets operate in the context of "commercial vacuums" as they substitute material capital with symbolic capital. This process is illuminated through Channel 2's inability to work MDHH into its extremely successful routine broadcasting formulas. The channel's MDHH broadcasts construct a commemorative narrative that is insulated from day-to-day Israeli public Holocaust memory discourse; hence they operate as a significant site of Israeli postmemory work. Furthermore, such a narrative not only commemorates the memory of the Holocaust itself but also the ways in which Israeli culture used to narrate the memory of the Holocaust in the past.