耐腐蚀性镍基箔带钎料钎焊不锈钢接头性能

采用新型耐腐蚀性镍基箔带钎料BNi685对316L不锈钢进行真空钎焊,研究了钎焊间隙对钎缝组织及力学性能的影响,对比了新型BNi685钎料钎焊接头与商用BNi2钎料,BNi685膏状钎焊接头的耐腐蚀性. 结果表明,随着钎焊间隙的增加,钎焊接头的抗拉强度逐渐降低,钎缝中心的显微硬度增加. 钎焊间隙为50 μm时,接头平均抗拉强度为244 MPa,钎缝组织主要由Ni_2.9Cr_0.7Fe_0.36,CrNiP,Cr₃P,Ni₅Cr₃Si相组成. 随着钎焊间隙增加,钎缝中心的CrNiP,Cr₃,Ni₅Cr₃Si相增多,Ni_2.9Cr_0.7Fe_0.36相减少. BNi685钎料钎焊接头的耐腐蚀性优于BNi2和BNi685膏状钎料钎焊接头,在EGR冷却器制造领域具有较大的应用潜力.     

Using clinical information in goal-oriented learning.

We have proposed an extension to the Q-learning algorithm that incorporates the existing clinical expertise into the trial-and-error process of acquiring an appropriate administration strategy of rHuEPO to patients with anemia due to ESRD. The specific modification lies in multiple updates of the Q-values for several dose/response combinations during a single learning event. This in turn decreases the risk of administering doses that are inadequate in certain situations and thus increases the speed of the learning process. We have evaluated the proposed method using a simulation test-bed involving an "artificial patient" and compared the outcomes to those obtained by a classical Q-learning and a numerical implementation of a clinically used administration protocol for anemia management. The outcomes of the simulated treatments demonstrate that the proposed method is a more effective tool than the traditional Q-learning. Furthermore, we have observed that it has a potential to provide even more stable anemia management than the AMP.     

Comparative analysis of viscosity of complex liquids and cytoplasm of mammalian cells at the nanoscale

We present a scaling formula for size-dependent viscosity coefficients for proteins, polymers, and fluorescent dyes diffusing in complex liquids. The formula was used to analyze the mobilities of probes of different sizes in HeLa and Swiss 3T3 mammalian cells. This analysis unveils in the cytoplasm two length scales: (i) the correlation length ξ (approximately 5 nm in HeLa and 7 nm in Swiss 3T3 cells) and (ii) the limiting length scale that marks the crossover between nano- and macroscale viscosity (approximately 86 nm in HeLa and 30 nm in Swiss 3T3 cells). During motion, probes smaller than ξ experienced matrix viscosity: η(matrix) ≈ 2.0 mPa·s for HeLa and 0.88 mPa·s for Swiss 3T3 cells. Probes much larger than the limiting length scale experienced macroscopic viscosity, η(macro) ≈ 4.4 × 10(-2) and 2.4 × 10(-2) Pa·s for HeLa and Swiss 3T3 cells, respectively. Our results are persistent for the lengths scales from 0.14 nm to a few hundred nanometers.     

Determination of the interfacial area and mass transfer coefficients in the Taylor gas–liquid flow in a microchannel

The interfacial area in the Taylor (slug) gas–liquid flow in a microchannel was measured by the Danckwerts' (chemical) method, using CO₂ absorption from the CO₂/N₂ mixture into KHCO₃/K₂CO₃ buffer solutions, containing NaOCl as a catalyst. The rate of absorption was determined and the Danckwerts' plots were constructed. Reasonable agreement with the geometrical area measured photographically was obtained. This fact allowed to determine for the first time the mass transfer coefficients separately for liquid film and liquid caps. A correlation for the calculation of mass transfer coefficients has been proposed.     

Use of brassica plants in the phytoremediation and biofumigation processes

In recent decades, serious contamination of soils by heavy metals has been reported. It is therefore a matter of urgency to develop a new and efficient technology for removing contaminants from soil. Another aspect to this problem is that environmental pollution decreases the biological quality of soil, which is why pesticides and fertilizers are being used in ever-larger quantities. The environmentally friendly solutions to these problems are phytoremediation, which is a technology that cleanses the soil of heavy metals, and biofumigation, a process that helps to protect crops using natural plant compounds. So far, these methods have only been used separately; however, research on a technology that combines them both using white cabbage has been carried out.     

Green aspects of techniques for the determination of currently used pesticides in environmental samples

Pesticides are among the most dangerous environmental pollutants because of their stability, mobility and long-term effects on living organisms. Their presence in the environment is a particular danger. It is therefore crucial to monitor pesticide residues using all available analytical methods. The analysis of environmental samples for the presence of pesticides is very difficult: the processes involved in sample preparation are labor-intensive and time-consuming. To date, it has been standard practice to use large quantities of organic solvents in the sample preparation process; but as these solvents are themselves hazardous, solvent-less and solvent-minimized techniques are becoming popular. The application of Green Chemistry principles to sample preparation is primarily leading to the miniaturization of procedures and the use of solvent-less techniques, and these are discussed in the paper.     

Energy consumption and CO2 emissions of the European glass industry

An in-depth analysis of the energy consumption and CO₂ emissions of the European glass industry is presented. The analysis is based on data of the EU ETS for the period 2005–2007 (Phase I). The scope of this study comprises the European glass industry as a whole and its seven subsectors. The analysis is based on an assignment of the glass installations (ca. 450) within the EU ETS to the corresponding subsectors and an adequate matching of the respective production volumes. A result is the assessment of the overall final energy consumption (fuel, electricity) as well as the overall CO₂ emissions (process, combustion and indirect emissions) of the glass industry and its subsectors in the EU25/27. Moreover, figures on fuel mix as well as fuel intensity and CO₂ emissions intensity (i.e. carbon intensity) are presented for each of the subsectors on aggregated levels and for selected EU Member States separately. The average intensity of fuel consumption and direct CO₂ emissions of the EU25 glass industry decreased from 2005 to 2007 by about 4% and amounted in 2007 to 7.8 GJ and 0.57 _tCO₂${\mathrm{t}}_{{\text{CO}}_{\mathrm{2}}}$ per tonne of saleable product, respectively. The economic energy intensity was evaluated with 0.46 toe/1000€ (EU27).     

Fabrication of the self‐reinforced composites using co‐extrusion technique

The results of this work relate to the use of co‐extrusion technology in the preparation of monocomposite pellets. The low‐melting polypropylene copolymer was used as a matrix material. The high strength polypropylene fibers were used as a fibrous reinforcement. Research confirms the possibility to produce the pellets with fibrous structure. The prepared composite material in the form of pellets was processed and shaped using the injection molding technology. Obtained samples were subjected to mechanical testing in the static tensile test and dynamic mechanical analysis. Research complements microscopic observation of scanning electron microscopy. The measurement results confirm the reinforcing effect of the fibers. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 41180.     

Comparison of the effects of different chemical activation methods on properties of carbonaceous adsorbents obtained from cherry stones

A method for obtaining activated carbons from cherry stones by chemical activation with NaOH is described. Carbonaceous adsorbents were obtained by two methods of activation (physical mixing and impregnation) and two variants of thermal treatment (at a constant or increasing temperature). Cherry stones were proved to be effective cheap precursors of carbon adsorbents, characterised by large pore volume (ranging from 0.22 to 0.47 cm³/g) and good sorption abilities (iodine number from 343 to 996 mg/g). The activated carbons obtained usually have strongly microporous structure and acidic surface character. The best physicochemical properties and adsorption properties towards iodine were found to be shown by the carbon samples obtained by physical mixing of the precursor or char with the activating agent followed by activation at 600 °C.     

Influence of fire retardants on smoke generation from wood and wood derived materials

The influence of three fire retardant agents: Polichron, Pyrolak W-10, and Pyrolak W-10 + Pyrolak W-1 on smoke density of pine wood, plywood, soft hardboard and tough hardboard was investigated. Surface samples of 25 cm² (5 × 5 cm) were used and the heat flux was varied over the range of 1.0 to 4.0 W/cm². Reference: Tadeusz Cisek and Jacek Piechocki, Influence of Fire Retardants on Smoke Generation from Wood and Wood Derived Materials,Fire Technology, Vol. 21, No. 2, May 1985, p. 122.