黑液加热处理—改善非木材纤维黑液的蒸发和燃烧性能

讨论了黑液加热处理对芦苇硫酸盐浆和麦草碱法浆黑液的影响。试验采用工厂的黑液，黑液热处理有效地降低了这两种黑液的粘度，在相同２００ｍＰａｓ的粘度值，处理后的芦苇硫酸盐浆黑液固形物含量增加了约１０％，而麦草碱黑液增加了近１５％。增加黑液固形物含量可明显提高碱回收锅炉的生产效率，根据计算的结果，锅炉生产能力可增加１３％。     

A summary of methods applied to tool condition monitoring in drilling

This paper presents a summary of the monitoring methods, signal analysis and diagnostic techniques for tool wear and failure monitoring in drilling that have been tested and reported in the literature. The paper covers only indirect monitoring methods such as force, vibration and current measurements, i.e. direct monitoring methods based on dimensional measurement etc. are not included. Signal analysis techniques cover all the methods that have been used with indirect measurements including e.g. statistical parameters and Fast Fourier and Wavelet Transform. Only a limited number of automatic diagnostic tools have been developed for diagnosis of the condition of the tool in drilling. All of these rather diverse approaches that have been available are covered in this study. In the reported material there are both success stories and also those that have not been so successful. Only in a few of the papers have attempts been made to compare the chosen approach with other methods. Many of the papers only present one approach and unfortunately quite often the test material of the study is limited especially in what comes to the cutting process parameter variation, i.e. variation of cutting speed, feed rate, drill diameter and material and also workpiece material.     

Mining tailings as raw materials for reaction-sintered aluminosilicate ceramics: Effect of mineralogical composition on microstructure and properties

This paper presents studies on the utilization of aluminosilicate-based mining tailings as raw materials for mullite-based ceramics. Based on the 3:2 stoichiometric composition, mullite was synthesised by reactive sintering with a series of powder mixtures with alumina additions. X-ray diffractometry and scanning electron microscopy analyses revealed that, at the specific mineralogical composition, mullite structure formed surrounded by an amorphous glass phase in reaction-sintered powder mixtures. Results demonstrated that the chemical and mineralogical composition of mining tailings do have an effect on mullite formation possibilities and, only with the particular mineralogical composition, the mullite formation is possible regardless of the correct Al:Si ratio in tailings. Physical and mechanical properties of the formed ceramics were defined, showing comparable values to 3:2 mullite reference. Mullite structure formation enables a better thermal resistance up to above 1450?°C of the formed tailings-based ceramics compared to other aluminosilicates, reflecting their utilization potential for refractory ceramic applications.     

Stereolithography as a manufacturing method for a hierarchically porous ZSM-5 zeolite structure with adsorption capabilities

Hierarchically porous structures are important in adsorption applications and can be used in gas treatment. Hierarchy in adsorbents offers flow channels on different scales, resulting in fast gas flow into a structure. Additive manufacturing, a technology capable of forming intricate geometries, was seen as a potential method to form porous adsorption structures. Stereolithography was chosen as the fabrication method for hierarchically porous zeolite structures because of its high resolution and superior forming capability. The focus of this study was on tailoring the properties of light-cured resin to maximize stability during shaping and shape retention in the debinding stage. Successful slurry preparation was required for demonstrating that monoliths with channel geometry and retained adsorption properties can be manufactured with stereolithography. The final printed structures exhibited hierarchical porosity consisting of flow channels, macropores between the primary particles and the characteristic microporosity of zeolite framework. The structure was manufactured by using blue light to cure layers of resin containing ZSM-5 zeolite. An appropriate debinding heat-treatment cycle was generated based on the TGA and DSC thermal analysis results. The properties of the porous structure were analysed by comparing the BET surface area, XRD patterns and SEM images of as-received powder and a debound piece. The measured BET adsorption properties of the final monoliths remained comparable to the as-received ZSM-5 powder. Based on this study, stereolithography can be utilized to manufacture porous zeolite structures.     

Characterization of thin films based on reflectance and transmittance measurements at oblique angles of incidence

The optical parameters of a SiO2 thin-film coating determined from the spectral reflectance and transmittance measurements at various incidence angles, including the normal incidence and the Brewster's angle, are compared in this paper. The high-accuracy measurements were carried out through visible-near-infrared spectral regions by using our purpose-built instruments. The optical parameters obtained from the reflectance and the transmittance data are consistent over the angles of incidence and agree within 0.2%. The effect of important systematic factors in the oblique-incidence spectrophotometric measurements is also discussed.     

Asymmetry ratio as a parameter of Eu3+ local environment in phosphors

Study of the local environment of certain ion is quite a complex problem. Due to the unique luminescent properties, Eu³⁺ ions can be used as a structural probe. In this paper, effect of doping concentration, excitation wavelength and excitation mechanism on asymmetry ratio was systematically studied using Y₃Al₅O₁₂:Eu³⁺, YVO₄:Eu³⁺ and Y₂O₃:Eu³⁺nanophosphors. The asymmetry ratio gives information about the local surrounding and environmental changes around the Eu³⁺ ions. Asymmetry ratios of YAG:Eu³⁺ and YVO₄:Eu³⁺ nanopowders were calculated using standard technique and the obtained average values were found to be 0.75 and 8.2, respectively. However, it is found that standard method of asymmetry ratio calculation is suitable only for samples where all Eu³⁺ ions occupy one site. The “multisite model” of asymmetry ratio calculation was developed and used for Y₂O₃:Eu³⁺ nanocrystalline powders. Average value of asymmetry ratio for Eu³⁺ ions occupied “normal” sites is 6.0 and for Eu³⁺ ions occupied “defect” sites is 2.3.     

Oxidative stress during Baltic salmon feeding migration may be associated with yolk-sac fry mortality

The wild populations of salmon in the Baltic Sea suffer from yolk-sac fry mortality (M74). M74 mainly occurs in populations spawning in rivers flowing to the Gulfs of Bothnia and Finland. On the basis of studies with fry, M74 may be caused by oxidative stresses. Because the eggs of M74-offspring-producing females have lower thiamine and astaxanthin levels and more oxidized fatty acids than eggs of females producing healthy offspring, oxidative stresses that adult salmon experience during their feeding migration may be decisive for the development of M74. In this study we have measured several oxidative stress parameters and have evaluated bothtemporal and regional differences in these parameters in salmon individuals during their feeding migration. At present, salmon feeding in the Gulf of Finland and in the Bothnian Sea are affected by oxidative stress as compared to populations feeding in the Baltic Proper. Moreover, the feeding population of salmon in the central Baltic Proper suffered much more from oxidative stress in 1999 than in 2006-2007. In 1999 the incidence of M74 was higher than that expected in 2007/2008. Oxidative stresses experienced by feeding salmon may thus be behind the development of M74.     

The aroma of the fruit of sea Buckthorn,Hippophae rhamnoides, L.

Summary Volatile components of Sea Buckthorn fruit were studied by combined gas chromatography-mass spectrometry. A total of 60 components were identified, corresponding to about 36 mg/kg of the total volatile oil. The aroma of Sea Buckthorn fruit was characterized by the presence of several aliphatic esters such as ethyl, 3-methylbutyl andcis-3-hexen-1-y1 esters. The most important compounds were ethyl hexanoate, 3-methylbutyl 3-methylbutanoate, 3-methylbutanoic acid, 3-methylbutyl hexanoate, 3-methylbutyl benzoate and 3-methylbutyl octanoate. The concentrations of terpenes and aromatic compounds were surprising low.

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Das Aroma von Sanddornfrüchten,Hippophae rhamnoides, L.

Zusammenfassung Die flüchtigen Aromastoffe von Sanddornfrüchten wurden gaschromatographisch-massenspektrometrisch bestimmt. Bei einem Gehalt von etwa 36 mg/kg wurden insgesamt 60 flüchtige Verbindungen identifiziert. Für das Aroma ist die Anwesenheit von zahlreichen aliphatischen Estern wie Ethyl-, 3-Methylbutyl- und cis-3-Hexen-1-y1-Estern charakteristisch. Die Hauptkomponenten sind Ethyl-hexanoat, 3-Methylbutyl-3-methylbutanoat, 3-Methylbutansäure, 3-Methylbutylhexanoat, 3-Methylbutylbenzoat und 3-Methylbutyloctanoat. Dagegen sind die Konzentrationen an Terpenen und aromatischen Verbindungen überraschend niedrig.

     

Phosphorescent metalloporphyrins as labels in time-resolved luminescence microscopy: effect of mounting on emission intensity

In this study, we present an investigation of the effects of mounting media on the phosphorescence of metalloporphyrin stained microscopy samples. The samples were: (1) Platinum(II) coproporphyrin (=PtCP) stained porous Sephadex beads; (2) compact polystyrene microspheres coated with IgG-PtCP conjugate; and (3) immunocytochemically labeled human peripheral blood neutrophils. The human neutrophils in a mixed leukocyte population were fixed, permeabilized, and then immunolabeled with PtCP conjugate of monoclonal mouse IgG directed to the intracellular antigen myeloperoxidase. The samples were mounted in twelve different mounting media and studied with quantitative time-resolved luminescence imaging microscopy with respect to the intensity and stability of the phosphorescence signal. The results indicate that microscopy samples stained with PtCP exhibit the brightest phosphorescence emission in non-mounted form or when mounted in non-aqueous permanent mounting media.