用碱回收炉增加电产量的可能性--用多种工艺参数比较背压汽轮机和冷凝汽轮机

人们对用黑液碱回收炉来增加发电量的重要性认识不断提高,这些变化的主要原因是电的价格.本文将介绍增加电产量的某些传统方法、一些新的思想和见解,特别是采用冷凝汽轮机.本研究的基本事例为一台传统的碱回收炉,能力为4000t(固形物)/24h,同时配备有背压汽轮机和冷凝汽轮机.将要介绍的这些方法为:增加黑液固形物含量、空气预热、吹灰系统、给水预热、蒸汽参数和电除尘后的热回收.     

Label-free detection of DNA-binding proteins based on microfluidic solid-state molecular beacon sensor

A solid-state molecular beacon using a gold support as a fluorescence quencher is combined with a polydimethylsiloxane (PDMS) microfluidic channel to construct an optical sensor for detecting single-stranded DNA binding protein (SSBP) and histone protein. The single-stranded DNA-Cy3 probe or double-stranded DNA-Cy3 probe immobilized on the gold surface is prepared for the detection of SSBP or histone, respectively. Due to the different quenching ability of gold to the immobilized single-stranded DNA-Cy3 probe and the immobilized double-stranded DNA-Cy3 probe, low fluorescence intensity of the attached single-stranded DNA-Cy3 is obtained in SSBP detection, whereas high fluorescence intensity of the attached double-stranded DNA-Cy3 is obtained in histone detection. The amounts of SSBP in sample solutions are determined from the degree of fluorescence recovery of the immobilized single-stranded DNA-Cy3 probe, whereas that of histone in sample solutions is determined from the degree of fluorescence quenching of the immobilized double-stranded DNA-Cy3 probe. Using this approach, label-free detection of target proteins at nanomolar concentrations is achieved in a convenient, general, continuous flow format. Our approach has high potential for the highly sensitive label-free detection of various proteins based on binding-induced conformation changes of immobilized DNA probes.     

Molecular mechanisms of mutations in factor XIII A-subunit deficiency: in vitro expression in COS-cells demonstrates intracellular degradation of the mutant proteins

Factor XIII deficiency is an autosomal recessive bleeding disorder that is largely caused by various mutations in FXIII A-subunit gene. Characteristically, the patients lack both A-subunit activity and antigen in the circulation. Here we have analysed the consequences of four missense mutations (Met242-->Thr, Arg252-->Ile, Arg326-->Gln, Leu498 to Pro) and one stop mutation (Arg661-->Stop) in the FXIII A-subunit gene by expression in COS-cells. After transient transfection each mutant cDNA expressed mRNA at an equal level to the wild type FXIII. However, the mutant polypeptides accumulated in the cells in significantly reduced quantities and demonstrated only very low enzymatic activity. Analysis of immunoprecipitated metabolically labelled polypeptides demonstrated remarkable instability and intracellular degradation of all mutant FXIII proteins. These results verify the deleterious nature of the individual amino acid changes and confirm that protein instability and susceptibility to proteolysis are consequences of the mutations, as predicted from the three-dimensional model of crystallised FXIII A-subunit.     

Mortars containing wood-based fibres under thermal exposure using cone calorimeter heating

The behaviour of concrete structures under fire can be improved by adding fibers. However, relatively little is known of the details of the possible beneficial features of the fibre addition. The aim of this study was to compare the effects of different wood-based fibres on the thermal properties of a standard laboratory cement mortar at conditions of a developing fire. The cone calorimeter heating method was used, and the sample thickness and heat flux were varied (25 mm or 50 mm, 25 kWm^?2 or 50 kWm^?2) to compare test conditions. The fibres comprised chemical pulp, chemi-thermomechanical pulp, recycled fibres and viscose fibres. The fibre content in the mortar was 0.15–0.5% by weight. Temperature and mass loos measurements of oven-dried specimens (moisture content <0.1%) showed no differences between different wood-based fibre mortars and plain mortar. With increasing moisture content (about 5%), however, the presence of fibres affected the release of moisture from the fibre mortar material. With rapid heating of mortars, which have a moisture content of about 5%, local pressures are easily built up. These pressures are mainly caused by free water vaporization. The rear surface temperature measurements indicate that in mortars containing wood-based fibres (0.15–0.5% by weight) the vaporization temperatures may be 20 –25% lower than in the reference mortar. Some effects on heat transfer can also be observed due to differences in water vaporization and movement processes.     

Properties of crystalline reduced nicotinamide adenine dinucleotide phosphate-adrenodoxin reductase from bovine adrenocortical mitochonria. I. Physicochemical properties of holo- and apo-NADPH-adrenodoxin reductase and interaction between non-heme iron proteins and the reductase

A crystalline NADPH-adrenodoxin reductase was obtained from bovine adrenocortical mitochondria and its properties were investigated. Its molecular weights and isoelectric point were estimated to be 51 000 and 5.4, respectively. Amino acid and sugar contents and the interaction between the apo-reductase and flavin of NADPH-adrenodoxin reductase were investigated. Formation of a complex of bovine NADPH-adrenodoxin reductase with adrenodoxin, its apoadrenodoxin, or other non-heme iron proteins caused quenching of fluorescence of the tryptophanyl residue and bound FAD of the NADPH-adrenodoxin reductase. The results obatined suggest that adrenodoxin and apoadrenodoxin bind functionally to a site close to the tryptophanyl residue and the bound FAD of the reductase. The circular dichroism spectrum of oxidized NADPH-adrenodoxin reductase was measured in the ultraviolet and visible regions. This spectrum showed negative absorption in the visible region and was not appreciably influenced in either the ultraviolet or visible region by formation of a complex with adrenodoxin or apoadrenodoxin.     

Preparation of barium titanate nanoparticle sphere arrays and their dielectric properties

Barium titanate (BaTiO3) nanoparticles from 27 to 192 nm were prepared by the 2-step thermal decomposition method from barium titanyl oxalate nanoparticles. These particles were dispersed well into 1-propanol, and dense BaTiO3 nanoparticle sphere arrays without stress-field were prepared by the meniscus method. Temperature dependence of dielectric properties was successfully measured using these dense nanoparticle sphere arrays, and size effect on dielectric properties was discussed.     

Synthesis and characterization of calcium–alumino-silicate hydrates from oil shale ash – Towards industrial applications

The influence of the alkaline medium on the hydrothermal activation of the oil shale fly ash with NaOH and KOH was studied using SEM/EDX, XRD, ²⁹Si and ²⁷Al high-resolution MAS-NMR spectra. In the presence of NaOH the silicon in the original fly ash was completely converted into calcium–aluminum–silicate–hydrates, mainly into 1.1 nm tobermorite structure during 24-h treatment at 160 °C. At similar reaction conditions, the activation with KOH resulted only to the formation of amorphous calcium–silica-hydrate gel on the surface of ash particles at temperature. The results obtained in this study indicate that the oil shale fly ash can be used for production of Al-substituted tobermorites when strongly alkaline media (NaOH) is applied. The synthesized product was used in a catalytic d-lactose isomerization reaction.