Photochemistry of Nanostructured Materials for Energy Applications

A number of major disciplines have separately developed as distinctfields of energy research utilizing nanostructure materials: i.Heterogeneous photocatalysis; ii. Photoelectrochemistry—includingelectrochemical photovoltaic cells; iii. Photochemistry in zeolites andintercalated materials; iv. Photochemistry of thin films andmembranes—including self assembled structures; and v. Supramolecularphotochemistry. Photophysical properties of small particles, in the angstromto nanosized regime—depending on specific material, resulting in bandgap broadening as compared to bulk properties, and corresponding phenomenawith organic dyes as a function of aggregate size having relevance to energyrelated applications are discussed, as are dielectric confinement effectscontrolling the geometric distribution of light absorption within aparticle, aggregate or adsorbed molecular deposit. Synergism among fieldshas emerged, as for example with transition metal oxide photocatalysts andphotoelectrodes, combined with supramolecular spectral sensitizingtransition metal ligand complexes used to harvest light and vectoriallytransfer photo-generated electrons and holes along selected energeticpathways. Two systems have already demonstrated potential for significantlyreducing reliance on fossil fuels and concomitant environmental stress.These are: i. Pollution remediation with wide band gap semiconductingparticulate and nanoporous photocatalysts; and ii. Electrochemicalphotovoltaic cells utilizing nanoporous semiconducting electrodes fabricatedby lightly sintering nanosized TiOÄ2É particulates, followed byspectral sensitization with tri-nuclear ruthenium ligand dyes.Heterojunction contacts between inorganic photoconducting particulates,termed photocatalytic diodes, and three phase systems, termed photocatalytictransistors, have been demonstrated to increase photocatalytic conversionefficiency in catalytic processes and to increase light sensitivity ofanalogous silver halide photographic systems. Research being carried out inlaboratories throughout the world, aimed at improving the efficiency andunderstanding of the multi-disciplinary processes involved are described.Suggested areas of investigation for achievement of short (5 years) andlong term (5–20 years) goals are reviewed.     

Vakuumimprägnierung poröser Metallwerkstücke mit anorganischen Nanosolen

Vacuum impregnation of porous metal materials with inorganic nanosol The sealing of porous metal pieces is possible by application of inorganic nanosols. For suitable sealing it is necessary that the nansols are applied by vacuum impregnation. For sealing useful nanosols contain particles of silicon/aluminium‐oxide with a modification of organic methyl groups. The nanosol particles are smaller than 100nm and the maximum of the particle size distribution is around 10nm. Beside sealing of the metal pieces, also their stability against corrosion can be improved by this nanosol application. The further development of this technology is especially promising for applications in machine factory or automobile.     

On O16–O18 Isotope Effects in Manganese Perovskites

Large isotope effects which have been found by others [1,2] in some colossal magneto resistance manganite perovskites, AMnO₃, are evidence of unusually strong interactions between the lattice and magnetism. We offer a model which is based upon the approximate degeneracy of two Mn⁺³ states: one with high spin S = 2, and the other with low spin S = 1. These states have different radii and different electron form factors. They thus have different force constants governing the interaction with neighboring oxygen ions which provide the sought for link between magnetism and oxygen mass. The experiments can be understood with the reasonable assumption that the LS has greater force constants than HS. The dependence of changes in T_c with isotopic substitution as a function of the A-ion radius, the metal insulator transitions and the Mossbauer effect changes, are discussed in terms of this model.     

三电平和两电平逆变器效率分析与比较

在分析、计算二极管箝位型三电平逆变器和两电平逆变器的通态损耗、开关损耗以及输出滤波电感损耗的基础上,对这两种逆变器的损耗、效率进行了比较。     

新型高压油浸组合互感器的研制与运用

文章阐述了几种组合互感器的特点,介绍了组合互感器的误差特性。较详细地介绍了由1台倒立式电流互感器和1台具有开放式铁心的电磁式电压互感器组合而成的新型高压组合互感器（VAU型）的基本特征及主要性能,测量结果表明,VAU型组合互感器误差特性好,瓷套管上电场强度沿高度分布均匀,体积小,占空间少,制造成本低,而且还可防铁磁谐振,现在的最高设备电压已达550kV。     

The Influence of an Acid-base-equilibrium on the Adsorption Behaviour of a Weak Polyampholyte

A weak diblock polyampholyte PMAA-b-PDMAEMA, poly(methacrylic acid)-block-poly((dimethylamino)ethyl methacrylate), was investigated as a model system for the influence of an acid-base-equilibrium of a phthalic acid buffer system on the polyelectrolyte adsorption behaviour. The adsorption of polyampholyte from aqueous solution onto silicon surfaces is known to be strongly influenced by the parameters of the polymer solution and the properties of the polyampholyte itself like block ratio or molecular weight. In the case of the investigated polyampholytes, the main parameter with the most significant influence on the adsorption is the pH. The big influence of pH on adsorption results from the charges of the polymer chains and the substrate, which are determined by the pH. Therefore, it should be useful to investigate the influence of a buffer system on the polyampholyte adsorption. On the one hand the buffer system enables to determine the pH of the aqueous polyampholyte solution more precisely. On the other hand the concentrations of different phthalic species like the phthalic acid, the hydrogen phthalate and the phthalate are strongly influenced by pH. These different species were observed to have a strong influence on the adsorption behaviour of the polyampholyte, so the adsorption as function of pH was observed to be also determined by the acid-base-equilibrium of the buffer system. The adsorbed amount of polyampholyte dried after the adsorption process was determined using ellipsometry, while the surface topography of these adsorbed layers were characterized by atomic force microscopy (AFM). This revised version was published online in July 2006 with corrections to the Cover Date.     

A Comprehensive Review of Genetically Engineered Mouse Models for Prader-Willi Syndrome Research

Prader-Willi syndrome (PWS) is a neurogenetic multifactorial disorder caused by the deletion or inactivation of paternally imprinted genes on human chromosome 15q11-q13. The affected homologous locus is on mouse chromosome 7C. The positional conservation and organization of genes including the imprinting pattern between mice and men implies similar physiological functions of this locus. Therefore, considerable efforts to recreate the pathogenesis of PWS have been accomplished in mouse models. We provide a summary of different mouse models that were generated for the analysis of PWS and discuss their impact on our current understanding of corresponding genes, their putative functions and the pathogenesis of PWS. Murine models of PWS unveiled the contribution of each affected gene to this multi-facetted disease, and also enabled the establishment of the minimal critical genomic region (PWScr) responsible for core symptoms, highlighting the importance of non-protein coding genes in the PWS locus. Although the underlying disease-causing mechanisms of PWS remain widely unresolved and existing mouse models do not fully capture the entire spectrum of the human PWS disorder, continuous improvements of genetically engineered mouse models have proven to be very powerful and valuable tools in PWS research.     

Phosphorylated sodium alginate/APP/DPER intumescent flame retardant used for polypropylene

Flame-retardant polypropylene (FR-PP) materials are realized by use of natural-sourced flame-retardant materials. Phosphorylated sodium alginate, ammonium polyphosphate, and dipentaerythritol are used to create an intumescent flame retardant (IFR). This realized flame retardant is embedded into polypropylene (PP) through melt blending method. The components, chemical structures, thermal properties, and degradation mechanisms of the samples are characterized by infrared spectrometry, thermogravimetric analysis, differential scanning calorimetry, scanning electron microscopy, and cone calorimeter test. The results indicate that an effective IFR is obtained due to gas phase and condensed phase synergistic flame-retardant ability during combustion and degradation of FR-PP. This work presents a facile method for preparing FR-PP with efficient flame retardancy. This study is a first proof of concept for an innovative flame retardant, which could find application in future in the fields of automotive industry and the construction of electronic devices. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 47794.     

Search for the most stable folds of protein chains: I. Application of a self-consistent molecular field theory to a problem of protein three-dimensional structure prediction

We present a general approach to the prediction of 3-D foldsof protein chains from their amino acid sequences. The approachis based on the use of the self-consistent molecular field theoryfor long-range interactions, the use of 1-D statistical mechanicsfor short-range interactions and on the discovery that thereis and should only be a relatively small discrete set of foldingpatterns. This makes it possible to examine the full varietyof ‘potentially stable’ folds and to determine thethermodynamically stable structure. In this paper, we give thegeneral theoretical background of the approach. The encouragingresults of the application of this approach to ß-domainsare described in another paper.     

Biosorbents based on pine sawdust and malt sprouts for preconcentration and ICP-OES determination of nonferrous,heavy, and precious metals in the environmental samples

Pine sawdust and malt sprouts modified with orthophosphoric acid and carbamide have been proposed for solid-phase extraction (SPE) of nonferrous, heavy, and precious metals and their subsequent determination in the environmental samples by inductively coupled plasma optical emission spectrometry (ICP-OES). Modified adsorbents were characterized by SEM, TGA, and FT-IR and compared with native matrixes. SPE of some nonferrous and precious metal ions by biosorbents was studied. Depending on the SPE conditions, it was possible to separate nonferrous and heavy metals from alkali and alkaline earth metals. The proposed adsorbents are effective for preconcentration of nonferrous and heavy metals from natural waters and precious metals from solutions after digestion of geological samples.