Thermal and Electrical Conductivity of Amorphous and Graphitized Carbide‐Derived Carbon Monoliths

The influence of graphitization and composition of carbide‐derived carbon (CDC) monoliths on the electrical and thermal conductivity was investigated. Carbon monoliths with varying porosities were synthesized employing biomorphous macroporous TiC and SiC as precursors. Graphitization was carried out in situ during high‐temperature chlorination with and without addition of nickel, iron, and cobalt chloride to the carbide. The graphitized monoliths showed improved properties. The results demonstrate that despite graphitic carbon also glass‐like carbon, stemming from the carbide synthesis, increases the thermal and electrical conductivity significantly.     

Changes of fluorescent spectral features after successive rare earth doping of gadolinium oxide powders

We present a complex fluorescence study of a series of gadolinium oxide polycrystalline powders singly, doubly and triply doped with trivalent rare earth ions (Er³⁺, Tb³⁺, and Dy³⁺), to explore a possibility of their use as materials for white light emitting diodes. The excitation and luminescence spectra along with the decay kinetics were measured in the temperature range from 6 to 300 K. The luminescence efficiency was studied within the visible spectral range, i.e. −400 nm to 750 nm under excitation by 355 nm third harmonic Nd:YAG laser pulses. Singly doped Er³⁺ sample gave stronger luminescence signals, but others showed significantly larger decay lifetimes. The successive rare earths doping leads to substantial changes of the spectral positions due to the up-conversion processes. In the singly (Er³⁺) doped sample, following the time resolved spectrum and decay curves, there are two different types of emissions: at 660 nm and at shorter wavelengths (below 640 nm) the red emission's lifetime is ten times longer than at shorter wavelengths. The singly doped sample shows unclear temperature-dependence of luminescence with lifetime at 550 nm (the longest at 100 K, similarly at 6 K and 300 K) and achieved luminous efficacy 73.5 lm/W.     

A Mixture Toxicity Study Employing Binary Combinations Of Dinitrobenzene And Trinitrobenzene Using The Bioluminescent Marine Bacterium Vibrio Harveyi As The Test Organism

A combination mixture study was conducted with two organic compounds, dinitrobenzene and trinitrobenzene, using the marine bioluminescent bacterium Vibrio harveyi . This assay employs the photogenic properties of this organism for determination of toxicity in a direct procedure. Evaluation of toxicity was performed using an additive index methodology, mixture toxicity index and graphic representations. Graphic representations employed were isobole plot and isobologram, both isopleths. The additive index procedure employed both chemicals at their estimated median effective concentration (EC 50 ) for determination of a toxicity value. Isopleths employed combinations of both chemicals, using an equitoxic concentration, at 20% intervals of their EC 50 . An additive index value for this mixture was statistically antagonistic. Mixture toxicity index suggests that these chemical in various combinations are antagonistic. Combinations for both isopleths were similar and exhibited additivity for three mixture values and statistical synergism for one mixture. Statistical analysis of combinations using the z test found some mixtures to be statistically different. This analysis, in part, supports findings for isopleths. These results suggest that different mixtures of the two chemicals may have different interaction outcomes.     

Relevance of the acid–base approach in prediction of adhesion properties in two‐component injection moulding

We demonstrate the use of innovative wetting method in prediction of the adhesion properties of biobased polymers for two‐component injection moulding, taking into account the acid–base surface properties of joined materials. The measurements were carried out in accordance with modified Berger method by calculation of the difference in shortened acidity parameter ΔD_short between hard and soft component. Correlation factors up to 0.99 were observed between ΔD_short and peel force. In comparison to results obtained by conventional wetting methods, high potential for the selection of components with high interface adhesion and for prediction of the functionality by the acid–base approach was demonstrated. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43048.     

增强现实技术于洪水风险沟通中的应用

气候变迁,特别是洪水问题给地处三角洲的城市带来了与日俱增的风险。作为应对手段,提出一种整合性的洪水风险管理方法,该方法确保了洪水风险沟通在洪水风险管理战略中的重要地位。洪水的可视化作为洪水风险沟通的一种工具,在改变人们对洪水风险的观念方面有着强大的作用。它可以通过互动的方式,使当地的利益相关者了解洪水的剩余风险和未来风险。其中增强现实技术作为一种可视化手段,它的快速发展与应用为风景园林设计、规划与教育等领域提供了崭新的交互方式。首先,探讨增强现实技术(AR)在洪水风险沟通中的应用现状,并重点关注增强现实技术的2个关键应用领域:对现场决策的支持和针对高层次设计的可视化与对景观干预的评估。随后,展示一种基于增强现实技术所开发的应用,该款创新性的应用为洪水风险沟通提供了一种轻量化的可视化手段。     

Properties and weldability of plasticized polylactic acid films

The objectives of the presented work were to investigate films based on polylactic acid (PLA) and polyethylene glycol (PEG) in order to improve ductility and weldability of PLA films. The effect of plasticizer amount on the thermal, rheological, and mechanical properties of PLA plasticized films was investigated. The PEG content does affect the glass transition and the cold crystallization temperature of PLA in blends, while the melting temperature was not affected by the addition of PEG. The complex viscosity of the neat PLA granules and of plasticized films showed strong temperature and angular velocity dependence. The Young's modulus and tensile strength of plasticized films were improved with increasing plasticizer concentration, while the elongation at break stays rather constant. Plasticized PLA films were furthermore heat welded. These investigations showed that plasticized PLA films can be welded by heat welding. The obtained weld strength is strongly depending on the PEG amount as well as on selected welding parameters. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40394.     

Über die Struktur cyclisierter Fettsäureester

The Structure of Cyclised Fatty Acid Esters It is proved that the cyclic fatty acids which are obtained from tung and linseed oils by alkali-treatment contain mainly two types of products. Approximately 30% of these consist of 1,2-disubstituted cyclohexadiens, whose one double bond of the ring is in the 1-position and the other one is conjugated to the former. Approximately 60% of the mixture is comprised of ω-(2-alkyliden-cyclohexenyl)-fatty acid esters. The double bond in the ring is predominantly in the 3-position. As a result of the rearrangement of double bonds before cyclisation, R′varies from C₂ to C₁₁ and R″ from C₀ to C₉.