Response of Doppler spacecraft tracking to gravitational radiation

A calculation is made of the effect of gravity waves on the observed Doppler shift of a sinusoidal electromagnetic signal transmitted to, and transponded from, a distant spacecraft. We find that the effect of plane gravity waves on such observations is not intuitively immediate and in fact can have surprisingly different spectral signatures for different spacecraft directions and distances. We suggest the possibility of detecting such plane waves by simultaneous coherent Doppler tracking of several spacecraft.     

Synthesis of the Gastrointestinal Peptide Hormone Secretin by the Repetitive Excess Mixed Anhydride (REMA) Method

The REMA method was found to be very suitable for the synthesis of secretin. The procedure was rapid, since on a 0.2 mmol-scale the rate of one amino acid per day could be attained, and yielded an unambiguous product after simple ion-exchange chromatography. REMA-secretin was found to be chemically identical with secretin prepared by fragment condensations and showed a biological activity of 3.4 (2.9–4.3) clinical units/μg, comparable to that of the natural product (4 clinical units/μg). The yield of purified secretin, a heptacosapeptide amide, calculated on the basis of C-terminal residue, amounted to 5%.     

Introduction of a planar defect in a molecularly imprinted photonic crystal sensor for the detection of bisphenol A

This paper reports the preparation of a molecularly imprinted inverse opal hydrogel containing a 2D defect layer, by combining the Langmuir-Blodgett technique and the photonic crystal template method. By coupling the exceptional characteristics of molecularly imprinted polymers, sensitive to the presence of a target molecule, and those of photonic crystals in a single device, we could obtain a defect-embedded imprinted photonic polymer consisting in a three-dimensional, highly-ordered and interconnected macroporous array, where nanocavities complementary to analytes in shape and binding sites are distributed. As a proof of concept, we prepared a three-dimensional macroporous array of poly(methacrylic acid) (PMAA) containing molecular imprints of bisphenol A (BPA) and a planar defect layer consisting in macropores of different size. The optical properties of the resulting inverse opal were investigated using reflection spectroscopy. The defect layer was shown to enhance the sensitivity of the photonic crystal material, opening new possibilities towards the development smart optical sensing devices.     

Rheological changes in the bitumen caused by heating and interaction with rubber during asphalt–rubber production

The demand for more safe and durable roads, combined with the need to preserve the environment, led to the production and application of asphalt–rubber (AR) on roads. Nevertheless, this complex material needs further study in order to better distinguish among the phenomena that take place during AR production, as they impact on the final product characteristics. Here, we effectively quantify the rheological changes related to bitumen aging due to diffusion of small molecules of bitumen into the rubber particles and to the release of fillers from rubber into the bitumen during AR production. “A sphere AR production simulator” was developed to assess AR aging independently. The comparison of the characteristic relaxation times of both AR and simulated AR shows that the aging alone cannot explain the rheological changes during AR production. The extent of the changes related to the combined effects of aging and filler release increases as the bitumen used to produce AR is softer.     

Extraction of bulk wave characteristics from a pulsed ultrasonic polar scan

The pulsed ultrasonic polar scan (P-UPS) technique provides a map with characteristic contours reflecting the critical bulk wave angles, which directly relate to the in-plane elastic properties of the insonified material spot. Besides these contours, additional information is captured in a P-UPS experiment which has particular importance for the inspection of anisotropic materials. By extensive post-processing on a single P-UPS experiment, we successfully extracted the local directional (i) critical bulk wave angles, (ii) phase velocity profiles, (iii) slowness curves, (iv) walk-off angles and (v) energy velocity profiles, for the three different polarization states of bulk waves. The procedure is demonstrated and discussed for an isotropic aluminum sample as well as an autoclave manufactured orthotropic _[0]8${\left[0\right]}_8$ carbon/epoxy laminate. In addition, a numerical and experimental investigation of the role of the immersion liquid as a lens for the P-UPS result is performed. This lensing effect permits to zoom in/out on the P-UPS fingerprint, hence broadening the class of materials which can be inspected by the P-UPS technique.     

Luminescent columnar liquid crystals based on tristriazolotriazine

Five discotic molecules comprising a tris[1,2,4]triazolo[1,3,5] triazine core were designed and synthesized to obtain luminescent and charge-transporting columnar liquid crystalline materials. With the exception of one compound containing terminal hydroxyl groups all compounds presented a wide thermal range and stable columnar liquid crystalline phase, characterized by differential scanning calorimetry, polarized optical microscopy, and X-ray diffraction (XRD) techniques. The phase formation appeared to be associated to some extent with interdigitation of the alkoxy and benzylalkoxy portion, as suggested by the XRD results. All compounds have a strong blue luminescence in solution and solid phase. At the temperature at which the compounds enter in the mesophase the luminescence decreases significantly. This result suggests that entrance into the Col(h) phase is accompanied by a better π-stacking of the peripheral phenyl rings compared to the solid phase, consistent with the intramolecular distances (3.5 ?) observed in the XRD analysis. These compounds based on tristriazolotriazine are quite robust with good optical and thermal properties for application as solid state emitters, and we anticipate that they may provide an interesting alternative to other discotic molecules based on N-heterocycles, which generally present a high-temperature Col(h) phase.     

Catalytic Antioxidant Activity of Bis-Aniline-Derived Diselenides as GPx Mimics

Herein, we describe a simple and efficient route to access aniline-derived diselenides and evaluate their antioxidant/GPx-mimetic properties. The diselenides were obtained in good yields via ipso-substitution/reduction from the readily available 2-nitroaromatic halides (Cl, Br, I). These diselenides present GPx-mimetic properties, showing better antioxidant activity than the standard GPx-mimetic compounds, ebselen and diphenyl diselenide. DFT analysis demonstrated that the electronic properties of the substituents determine the charge delocalization and the partial charge on selenium, which correlate with the catalytic performances. The amino group concurs in the stabilization of the selenolate intermediate through a hydrogen bond with the selenium.     

Modeling and simulation of circulating fluidized bed reactors applied to a carbonation/calcination loop

A fluid dynamic model for a gas-solid circulating fluidized bed （CFB） designed using two coupled riser reactors is developed and implemented numerically with code programmed in Matlab. The fluid dynamic model contains heat and species mass balances to calculate temperatures and compositions for a carbonation/calcination loop process. Because of the high computational costs required to resolve the three-dimensional phenomena, a model representing a trade-offbetween computational time requirements and accuracy is developed. For dynamic processes with a solid flux between the two reactor units that depends on the fluid dynamics of both risers, a dynamic one-dimensional two-fluid model is sufficient. A two-fluid model using the constant particle viscosity closure for the stress term is used for the solid phase, and an algebraic turbulence model is applied to the gas phase. The numerical model implementa- tion is based on the finite volume method with a staggered grid scheme. The exchange of solids between the reactor units constituting the circulating fluidized bed （solid flux） is implemented through additional mass source/sink terms in the continuity equations of the two phases, For model validation, a relevant experimental analysis provided in the literature is reproduced by the numerical simulations, The numerical analysis indicates that sufficient heat integration between the two reactor units is important for the performance of the circulating fluidized bed system, The two-fluid model performs fairly well for this chemical process operated in a CFB designed as two coupled riser reactors. Further analysis and optimization of the solution algorithms and the reactor coupling strategy is warranted.     

Strongly convex set-valued maps

We introduce the notion of strongly $t$ -convex set-valued maps and present some properties of it. In particular, a Bernstein–Doetsch and Sierpiński-type theorems for strongly midconvex set-valued maps, as well as a Kuhn-type result are obtained. A representation of strongly $t$ -convex set-valued maps in inner product spaces and a characterization of inner product spaces involving this representation is given. Finally, a connection between strongly convex set-valued maps and strongly convex sets is presented.     

Brunn–Minkowski and Zhang inequalities for convolution bodies

A quantitative version of Minkowski sum, extending the definition of θ$\theta$-convolution of convex bodies, is studied to obtain extensions of the Brunn–Minkowski and Zhang inequalities, as well as, other interesting properties on Convex Geometry involving convolution bodies or polar projection bodies. The extension of this new version to more than two sets is also given.