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991.
992.
Paciorek-Sadowska Joanna Czupryński Bogusław Liszkowska Joanna 《Journal of Porous Materials》2011,18(5):631-638
Solid parts of the wheat slops (90% w/w of dry mass and 10% w/w of water) were applied as a filler (5–30% w/w in relation
to the sum of polyisocyanate and polyol masses) in PUR-PIR composition. Six foams containing different amounts of slops were
prepared by this method and then, their physical–mechanical properties i.e. apparent density, compressive strength, brittleness,
after-combustion residue, stability of linear dimensions, change of volume, loss in mass (48 h, temp 120 °C), softening point,
content of the closed cells and absorbability of water were determined. Moreover, the foams were subjected to thermogravimetric
and infrared analyses. 相似文献
993.
994.
A. Grajcar M. Kciuk S. Topolska A. Płachcińska 《Journal of Materials Engineering and Performance》2016,25(6):2245-2254
The electrochemical corrosion properties of 26Mn-3Si-3Al and 27Mn-4Si-2Al austenitic steels in two different states were studied in 0.1 M H2SO4 and 3.5% NaCl using potentiodynamic polarization tests. The effect of cold deformation on the microstructure and corrosion behavior of steels was analyzed. In acid solution, both steels exhibited lower corrosion resistance than in chloride solution independently on the steel state (hot-rolled, cold-worked). Cold deformation decreases the corrosion resistance, though this effect is smaller than the effect of chemical composition related to the combined Al + Si addition. All steels showed the evidence of pitting corrosion. The intensive dissolution of Fe and Mn takes place in the acid medium. 相似文献
995.
Tomasz Gancarz Zbigniew Moser Władysław Gąsior Janusz Pstruś Hani Henein 《International Journal of Thermophysics》2011,32(6):1210-1233
This work is aimed at comparing several methods for the measurement of physical properties for molten Sn and Sn–Ag alloys,
namely, surface tension, density, and viscosity. The method used for viscosity in this work is the modified capillary method.
For surface tension and density, the data used for comparison were previously measured using the maximum bubble pressure method
and the dilatometer technique, respectively, for four Sn–Ag alloys having (3.8, 32, 55, and 68) at% Ag. The results are compared
with those obtained using a new method based on a fluid draining from a crucible under the influence of gravity, designated
the Roach–Henein (RH) method. This new method enables the determination of these three physical properties in one set of measurements.
Liquid Sn was used as well as two liquid Sn–Ag alloys having (3.8 and 34.6) at% Ag with the RH method. It was determined that
the RH method may be used to simultaneously obtain surface tension, viscosity, and density and that the errors associated
with these measurements were similar to those obtained using traditional and separate techniques. Comparisons of the measured
viscosity and surface tension to those predicted using thermodynamic models will also be presented. Finally a comparison of
mixing model predictions with the experimentally measured alloy surface tension and viscosity is also presented. 相似文献
996.
Tomasz Sokół 《Structural and Multidisciplinary Optimization》2011,43(2):181-190
The main purpose of the paper is to provide an easy-to-use code for topological optimization of the least weight trusses,
written in the Mathematica programming language. The main idea of the presented approach consists in using a fixed ground
structure and the linear programming formulation of the optimization problem. The solver is based on the fast interior point
method. The strong effort is done to create the effective generator of the computational model utilizing the high regularity
of the ground structure and the high sparsity of the geometric matrix. The efficiency and reliability of the algorithm is
confirmed in several numerical tests. Due to a linear programming formulation of the optimization problem the method presented
in the paper assures finding the global optimum, hence it may be considered as the useful tool for verification of results
obtained in other ways. The appended complete Mathematica code of the program developed will be supplied by the Publisher
on SpringerLink. 相似文献
997.
998.
Agnieszka Wiśniewska Krzysztof Sozański Tomasz Kalwarczyk Karolina Kędra-Królik Christoph Pieper Stefan A. Wieczorek Sławomir Jakieła Jörg Enderlein Robert Hołyst 《Polymer》2014
We postulate an empirical scaling equation, which accurately describes flow of polymer solutions, complimenting the paradigm of length-scale-dependent viscosity. We investigated poly(ethylene glycol) aqueous solutions and observed an exponential dependence of viscosity on the hydrodynamic radius of a single coil Rh divided by the correlation length ξ. Properties of the system changed abruptly with the onset of chain entanglement at concentration corresponding to ξ = Rh. We propose a single equation valid for all the investigated systems, analyze the physical meaning of parameters appearing therein and discuss the impact of chain entanglement. Viscous flow is treated as an activated process, following the Eyring rate theory. We show that the difference of activation energy for flow between pure solvent and polymer solution, ΔEa, is a function of concentration, whose derivative has a discontinuity at the crossover concentration. For dilute PEG solutions ΔEa takes values of up to several kJ/mol and is proportional to the intrinsic viscosity. We successfully apply the scaling approach to the diffusive motion of a protein (aldolase) in solutions of 25 kg/mol PEO (concentrations of 2–20%), investigated by fluorescence correlation spectroscopy (FCS). A significant difference in the influence of crowding on translational and rotational motion of the protein is revealed. 相似文献
999.
Magda Corgneau Claire Gaiani Jeremy Petit Yoana Nikolova Sylvie Banon Léa Ritié-Pertusa Doan Thanh Lam Le Joël Scher 《International Journal of Food Science & Technology》2019,54(6):2132-2140
Influence of diverse botanical sources (wheat, maize, waxy maize, cassava, potato, rice or waxy rice) on in vitro native starch digestibility has been investigated. Physicochemical properties (chemical composition, particles size and shape, surface features) of starch granules were determined with a view to explaining digestibility differences between samples. Rapidly digestible starch (RDS), slowly digestible starch (SDS) and resistant starch (RS) contents were measured according to Englyst method. Potato starch was shown to be composed of large rounded granules having smooth surfaces, which explains its slow enzymatic breakdown. Potato starch displayed the highest RS (86%) content and the lowest RDS content (9.9%). Since RS positively influences health and SDS may result in cell, tissue and/or organ damages, potato starch is an ideal starch nutrient. Conversely, waxy rice starch was rich in amylopectin and displayed small diameters and angular shapes, which are both known to facilitate enzymatic starch hydrolysis. It exhibited a near-zero RS content (0.9%) and a high RDS fraction (60%). According to this study, potato starch exhibited the best nutrient profile, followed up in this order by cassava, waxy maize, wheat, maize and waxy rice starches. 相似文献
1000.
Kropiowska Dorota Mikulski Leszek Szeptyński Paweł 《Structural and Multidisciplinary Optimization》2019,59(5):1581-1598
Structural and Multidisciplinary Optimization - An approximate thickness optimization of a rectangular Kirchhoff-Love plate with variable stiffness under uniform load is performed in this paper.... 相似文献