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11.
Tae-Jin Park Mark J. Davis Paula Vullo Tina M. Nenoff James L. Krumhansl Alexandra Navrotsky 《Journal of the American Ceramic Society》2009,92(9):2053-2058
Barium titanosilicates are possible oxide forms for the immobilization of short-lived fission products in radioactive waste. Ba2 TiSi2 O8 (fresnoite) and BaTiSiO5 (Ba-titanite) samples were prepared by a solid-state synthesis. The enthalpies of formation of Ba2 TiSi2 O8 crystal and glass at 25°C and of BaTiSiO5 glass were obtained from drop solution calorimetry in a molten lead borate (2PbO–B2 O3 ) solvent at 701°C. The enthalpy of formation for fresnoite composition samples from constituent oxides was exothermic and became more exothermic with increasing crystallinity. Differential scanning calorimetry revealed that the crystallization rate of the fresnoite glasses increased with increasing devitrification. A modified Product Consistency Test-Procedure B (PCT-B) was used to collect solubility data on the fresnoite and titanate phases. The tests suggest that both glassy and crystalline fresnoite exhibit favorable aqueous stability and should be explored further as radioactive waste forms for long-term storage. 相似文献
12.
This study investigated the effect of steam cooking on distribution of paralytic shellfish poisoning toxins (PSP-toxins) in scallops Patinopecten yessoensis. Toxins analysis by high-performance liquid chromatography showed that most of the PSP-toxins (>70%) were accumulated in viscera and adductor muscle of the raw scallops. Steam cooking induced significant loss (p < 0.05) of PSP-toxins from viscera (16%), adductor muscle (24%), gill and mantle (11%) while 32% of the toxins were retained inside viscera and adductor muscle. Overall, 51% of PSP-toxins leaked out from scallop tissues during steam cooking. However, there was no significant loss (p > 0.05) of PSP-toxins from gonad. Consumption of viscera was the most significant risk factor for causing PSP, while gonad and scallop soup were the second most significant. A rapid PSP test further verified detectable levels of PSP-toxins in all samples. However, possible interfering substance(s) in adductor muscles and gonads might potentially affect the results from this test. 相似文献
13.
In this research, the effect of carbon dioxide laser irradiation on various properties of raw and bleached cotton fabrics, including fabric weight, bending rigidity, wetting, and air permeability, as well as dyeing, was examined and compared. The experiments were carried out at three different laser powers ranging from 4.5 to 6 W to determine the effect of laser treatment on fabric properties. In particular, the influence of laser irradiation on the dyeing properties of treated fabrics with CI Reactive Blue 198 was studied. The colour change of laser‐treated fabrics was determined by calculation of the K/S values as a function of fabric reflectance. The morphological changes in laser‐treated fabrics were observed by scanning electron microscopy. The effects of laser treatment on the properties of raw and bleached cotton fabrics were varied. For instance, the wettability of raw cotton samples was reduced after laser irradiation, whereas the wettability of bleached cotton fabrics was greater. Possible reasons for the various dyeing behaviours observed with irradiation at different laser powers are discussed. 相似文献
14.
Jennifer Neville Brian Gallagher Tina Eliassi-Rad Tao Wang 《Knowledge and Information Systems》2012,30(1):31-55
Recently, a number of modeling techniques have been developed for data mining and machine learning in relational and network
domains where the instances are not independent and identically distributed (i.i.d.). These methods specifically exploit the
statistical dependencies among instances in order to improve classification accuracy. However, there has been little focus
on how these same dependencies affect our ability to draw accurate conclusions about the performance of the models. More specifically,
the complex link structure and attribute dependencies in relational data violate the assumptions of many conventional statistical
tests and make it difficult to use these tests to assess the models in an unbiased manner. In this work, we examine the task
of within-network classification and the question of whether two algorithms will learn models that will result in significantly
different levels of performance. We show that the commonly used form of evaluation (paired t-test on overlapping network samples) can result in an unacceptable level of Type I error. Furthermore, we show that Type
I error increases as (1) the correlation among instances increases and (2) the size of the evaluation set increases (i.e.,
the proportion of labeled nodes in the network decreases). We propose a method for network cross-validation that combined
with paired t-tests produces more acceptable levels of Type I error while still providing reasonable levels of statistical power (i.e.,
1−Type II error). 相似文献
15.
Tina Marolt Cebasek Jakob Likar 《土木工程与建筑:英文版》2014,(11):1457-1466
The design procedure is made for a mine shaft where permanent underground facilities are interconnected. The highly faulted grounds were identified using empirical and semi-empirical theories. Furthermore, the behavior types are presented. This paper presents excavation and support methods in such ground conditions and the calculations results show that the installation of the yielding elements have an effect on support elements and prevent shotcrete damage during the curing stage. Different numerical analyses carried out showed that, with the yielding elements installed, the total displacements increase but the final axial force reduces, and therefore, the characteristic compressive strength of shotcrete is not exceeded. The calculation results of ground loads and displacements on the designed support system are presented with a 3D numerical geo-mechanical model adopted for highly faulted ground surrounding deeper complex underground structures. 相似文献
16.
17.
Bor‐Sen Chiou Diana Valenzuela‐Medina Mark Wechsler Cristina Bilbao‐Sainz Artur K. Klamczynski Tina G. Williams Delilah F. Wood Greg M. Glenn William J. Orts 《应用聚合物科学杂志》2015,132(10)
Torrefied almond shells and wood chips were incorporated into polypropylene as fillers to produce torrefied biomass‐polymer composites. The composites were prepared by extrusion and injection molding. Response surface methodology was used to examine the effects of filler concentration, filler size, and lignin factor (relative lignin to cellulose concentration) on the material properties of the composites. The heat distortion temperatures, thermal properties, and tensile properties of the composites were characterized by thermomechanical analysis, differential scanning calorimetry, and tensile tests, respectively. The torrefied biomass composites had heat distortion temperatures of 8–24°C higher than that of neat polypropylene. This was due to the torrefied biomass restricting mobility of polypropylene chains, leading to higher temperatures for deformation. The incorporation of torrefied biomass generally resulted in an increase in glass transition temperature, but did not affect melting temperature. Also, the composites had lower tensile strength and elongation at break values than those of neat polypropylene, indicating weak adhesion between torrefied biomass and polypropylene. However, scanning electron microscopy results did indicate some adhesion between torrefied biomass and polypropylene. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 41582. 相似文献
18.
Genoveva Buelna Mutlu Ulutagay-Kartin Tina M. Nenoff 《Chemical Engineering Communications》2006,193(5):606-619
Alkylation reactions of benzene with propylene using heterogeneous catalysts H+-β zeolite, MCM-22, and ZSM-5 were studied for their affinity for cumene production. This work focused on the gas-phase reaction using different crystalline catalysts at several temperatures and amounts of reactants using both batch and continuous fixed-bed reactors. The properties of baseline commercial H+-β catalysts versus versions modified with Ga, La, and Pt were studied. Quantitative analysis of product mixture was performed by gas chromatography. For the batch reactor, β-zeolite produced the highest cumene yield and selectivity of 72% and 92%, respectively, at 225°C. At this temperature, a benzene:propylene dilution of 7:1 molar ratio was the optimum. For the continuous system, cumene production is favored at lower space velocities, higher benzene-to-propylene ratio, and temperatures close to 225°C. Ga modification of the H+-β zeolite significantly enhanced cumene yield in the continuous fixed-bed reactor at 225°C, from 27% of the unmodified β-zeolite to 36% for the Ga-modified one. The life span of modified β-catalysts was studied in the fixed-bed reactor for the first eight hours of reaction. 相似文献
19.
Cationic Nanogels: Reduction‐Sensitive Dextran Nanogels Aimed for Intracellular Delivery of Antigens (Adv. Funct. Mater. 20/2015) 下载免费PDF全文
20.
Tina M. Briere Marcel H. F. Sluiter Vijay Kumar Yoshiyuki Kawazoe 《Bulletin of Materials Science》2003,26(1):115-116
The geometries of several Mn clusters in the size range Mn13-Mn{on23} are studied via the generalized gradient approximation to density functional theory. For the 13-and 19-atom clusters, the
icosahedral structures are found to be most stable, while for the 15-atom cluster, the bcc structure is more favoured. The
clusters show ferrimagnetic spin configurations. 相似文献