Origins of the odd optical observables in plutonium and americium tungstates

A series of f-block tungstates show atypical coloration for both the Ce(iii) and Pu(iii) compounds; whereas the other lanthanide and Am(iii) compounds possess normal absorption features. The different optical properties are actually derived from the tungstate component rather than from 5f electrons/orbitals.

Experimental Investigation of the Effect of Generator Temperature on the Performance of Solution Transportation Absorption Chiller

It is effective to recover waste heat to reduce primary energy consumption. From this point of view, we proposed and examined a new idea of heat transportation using ammonia–water as the working fluid in the system named the Solution Transportation Absorption chiller (STA). As waste heat sources are not necessarily located close to areas of heat demand, conventionally, absorption chillers are located on heat source side and produce chilled water that is transported to heat demand side through pipelines with an insulation. In contrast, the proposed system STA divides an absorption chiller into two parts. The generator and the condenser are located on heat source side while the evaporator and the absorber are on heat demand side. Both the conventional system and STA system satisfy the same boundary condition of heat recovery and heat supply to the demand side, STA can work for transferring thermal energy as the conventional system does even though the temperature of the media is ambient without an insulation. Our previous studies of the STA were based on the experimental investigation with the STA facility where the cooling power was 90[Formula: see text]kW (25.6 refrigeration ton) at the generator temperature 120[Formula: see text]C from 0[Formula: see text]m (normal absorption chiller) to 1000[Formula: see text]m. Thus, the Coefficient of Performance (COP) of STA was found to have almost the same value of 0.65 with conventional absorption chillers without depending on the transportation distances. The objective of this study is to examine the effect of generator temperature from 100[Formula: see text]C to 120[Formula: see text]C on the performance of solution transportation of ammonia–water solution, because the generator temperature is directly linked to the waste heat temperature, so its effect needs to be investigated. The experimental facility tested the performance with 0[Formula: see text]m (normal absorption chiller), 200[Formula: see text]m and 500[Formula: see text]m distance. The results indicate that the effect of the generator temperature and solution transportation distances showed no significant on the COP.

Sound-Absorbing Composites Based on Flax and Polymer Fibers

The paper considers sound absorption of the composite materials, which are based on the natural flax and polymer fibers. The thickness of a single layer of obtained nonwoven composite is about 10 mm. The analysis of absorption dependences is carried out for different thicknesses of the material. It is shown that in the low frequency range the absorption almost linearly increases depending on the thickness. The coefficient of the normal absorption increases with the frequency in the range from 50 Hz up to 1600 Hz. The hot-pressed material can be used for panel production. The sound absorption increases with the thickness of the pressed material. The measurements show the possibilities of application of the composite for the production of the parts of cabs’ interior.

Consecutive intercalation of a cationic porphyrin dimer between the GC base-pairs: a kinetic study

One of the porphyrin moieties of the porphyrin dimer intercalates rapidly between the DNA base-pairs, followed by the slow intercalation of the other. The slow intercalation of the second porphyrin moiety of porphyrin dimer to poly[d(G-C)2] was investigated by normal absorption and circular dichroism spectroscopy. The change in absorbance in the Soret band of porphyrin upon association with poly[d(G-C)2] can be best elucidated by the combination of the two single exponential curves, suggesting the intercalation occurred via two independent first order reactions. Activation energies of these two first order reactions were calculated to be 0.37 kcal/mol and 3.19 kcal/mol, respectively. The intercalation associated with lower activation energy can be assigned to the intercalation of second porphyrin moiety to 5′CG3′ site while that with higher activation energy to 5′GC3′ intercalation site. Increasing the flexibility of poly[d(G-C)2] by adding Na+ ion resulted in an enhancement of the reaction rate for both steps in an exponential manner.

Experimental Research on the Normal Absorption Coefficient of the Multilayer Material

The normal absorption coefficient of the multilayer material was studied in this research. A measurement duct system was established at first, and then the absorption coefficients of multilayer material with different structures were measured through this experimental system. Some conclusions could be drawn: Compared with the uniform material, the multiple layer material can change the absorption coefficient significantly without increasing the thickness of the material in low frequency band. The position and the area density of the aluminum plate can both change the absorption coefficient significantly. The frequency corresponding to the absorbing peak value decreases with the increasing of the area density of aluminum plate. The absorption coefficient becomes larger near to one in low frequency band and in the meantime changes lower than 0.1 in the high frequency band. The position and area density of the aluminum plate can be designed to satisfy the requirements of the sound absorption.