Use of Tin-Bismuth (Sn–Bi) Eutectic Alloy in Contact with Austenitic Class Steel for Hydraulic Seals

Metallurgist - Quantitative results are presented for a study of the interaction of tin-bismuth eutectic alloy (used as a solder) as the working body of a hydraulic seal in contact with austenitic...     

Evaluation of Water Retention Functions and Computer Program “Rosetta” in Predicting Soil Water Characteristics of Seasonally Impounded Shrink–Swell Soils

Soil water retention is a critical factor influencing irrigation decisions and hence agricultural crop yields. However, information on soil water retention characteristics (SWRC) is seldom available for irrigation planning, crop yield modeling, or hydrological simulations, especially for problematic soils, such as seasonally impounded shrink-swell soils. As large scale direct measurement of SWRC is not viable due to a number of reasons, researchers have developed pedotransfer functions (PTFs) to estimate SWRC from easily measured soil properties, such as texture, organic matter content, bulk density, etc. However, PTF applicability in locations other than those of data collection has been rarely reported. One of the most recent PTFs that has shown overall reasonable predictions in evaluation studies is Rosetta, a numerical code for estimating soil hydraulic parameters with hierarchical pedotransfer functions. Relatively, the development of large databases makes it one of the widely used PTFs. If validated for spatial application, it has immense use potential in countries like India, where data on soil hydraulic properties are seldom available, a deficiency that hampers better simulations in processes, like partitioning runoff and infiltration, assessing evapotranspiration, irrigation scheduling, etc. Rosetta is also relatively flexible allowing estimation of hydraulic properties from easily available minimum input of textural fractions. This study was conducted to evaluate (1) an applicability of four widely used soil water retention functions to describe SWRC; and (2) the computer program Rosetta for its validity. Statistical indices, i.e., root mean square error (RMSE), mean absolute error, maximum absolute error, and degree of agreement (d) were computed to evaluate “goodness-of-fit” of the four functions to the measured SWRC data. These indices were also used to compare measured SWRC with estimates of SWRC by Rosetta. For soil samples collected from 41 profiles, 175 SWRC were measured in the laboratory. The van Genuchten function fitted relatively better (RMSE = 0.052?m3?m?3) to SWRC of clay soils, whereas the Brooks–Corey (BC) function was better in expressing SWRC of clay loam and sandy clay loam soils with RMSE = 0.06 and 0.07?m3?m?3, respectively. Campbell and Cass–Hutson (CH) functions were of intermediate value. Worst performing functions were BC (clay soils), Campbell (clay loam), and CH (sandy clay loam) with corresponding RMSE = 0.059, 0.065, and 0.077?m3?m?3. Estimates of two important points on the SWRC curve, i.e., field capacity and permanent wilting point were predicted with relatively better accuracy for clay and sandy clay loam soils by all the four functions. RMSE and d ranged from 0.027?to?0.043?m3?m?3 and from 0.73 to 0.88 for clay soils. Corresponding values for sandy clay loam soils were 0.008?–0.019?m3?m?3, and 0.92–0.98. However, in clay loam soils, only two functions were found suitable. Estimates of SWRC obtained by applying hierarchical rules in Rosetta were reliable (RMSE<0.05?m3?m?3). Magnitude of average RMSE increased progressively in clay loam, clay and sandy clay loam soils (0.028<0.035<0.042?m3?m?3). The study established that SWRC of the “Haveli” soils could be estimated using generic PTF and thus information that is prerequisite in simulating hydrological processes occurring in seasonally impounded soils could be acquired.     

Measurements of Thermal Conductivity Variations with Temperature for the Organic Analog of the Nonmetal–Nonmetal System: Urea–4-Bromo-2-Nitroaniline

Thermal conductivity variations with temperature for solid phases in the Urea (U)–[X] mol pct 4-bromo-2-nitroaniline (BNA) system (X = 0, 2, 45, 89.9, and 100) were measured using the radial heat flow method. From graphs of thermal conductivity variations with temperature, the thermal conductivities of the solid phases at their melting temperature and temperature coefficients for the U–[X] mol pct BNA system (X  =  0, 2, 45, 89.9, and 100) were found to be 0.26, 0.55, 0.46, 0.38, and 0.23 W/Km and 0.007781, 0.005552, 0.002058, 0.002188, and 0.002811 K^?1, respectively. The ratios of thermal conductivity of the liquid phase to thermal conductivity of the solid phase in the U–[X] mol pct BNA system (X  =  0, 2, 45, 89.9, and 100) were also measured to be 0.30, 0.44, 0.46, 0.49, and 0.51, respectively, with a Bridgman-type directional solidification apparatus at their melting temperature.     

Effects of word frequency and spelling–to–sound regularity in naming with and without preceding lexical decision.

The effects of word frequency and spelling-to-sound regularity were examined using standard naming, standard lexical-decision, go/no-go naming, and go/no-go lexical-decision tasks. In both the standard and go/no-go naming tasks, tasks requiring phonological coding, a significant Frequency?×?Regularity interaction was observed. That is, the regularity effect was limited to low-frequency words. In the standard and go/no-go lexical-decision tasks, tasks not requiring phonological coding, no Frequency?×?Regularity interaction was observed. These results indicate not only that the Frequency?×?Regularity interaction is a product of phonological coding processes but also that these processes are similar in the standard and go/no-go naming tasks. Results are discussed in terms of the dual-route and the parallel distributed processing frameworks. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Predicting adjustment in children and adolescents with sickle cell disease: A test of the risk-resistance–adaptation model.

Objective: A theoretical model was used to examine the impact of risk and resistance factors on the psychological adjustment of children and adolescents with sickle cell disease (SCD). Participants: One hundred eighteen children and adolescents with SCD receiving treatment at a comprehensive sickle cell center and their mothers. Measures: Included risk factors (condition parameters, functional independence, and disability stressors), resistance factors (stress processing, intrapersonal factors, and social ecological factors), and adjustment. Results: Adaptive behavior was associated with child maladjustment, severity of disability was associated with disability stress, and child competence was associated with child maladjustment. Coping did not moderate the association between stress and maladjustment, and adaptive behavior and stress did not mediate the association between severity of disability and maladjustment, as the model had predicted. Conclusions: Results support the continued use of theoretically driven models to investigate the adjustment of children and adolescents with chronic conditions and to promote comparisons of different chronic illnesses and disabling conditions… (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

G–D Map Method for Analyzing Effects of Elements on Size Control of In Situ Formed Mg2Si in Mg Melts

Metallurgical and Materials Transactions A - An approach for selecting alloying elements to control the size of an in situ formed phase is proposed based on a G–D map, which is derived from...     

Effects of cerium and tungsten addition on acid–base properties of spindle-like α-Fe2O3 in low-temperature SCR of NOx with NH3

Low-temperature selective catalytic reduction (SCR) is important for the elimination of NO_x from stationary sources. In the present study, the loading of Ce and W on α-Fe₂O₃ was achieved through the integration of single-mode microwave and incipient wetness impregnation (IWI) methods. The scanning electron microscopy (SEM) and transmission electron microscopy (TEM) images reveal that the structure of α-Fe₂O₃ is spindle-like, and the structure remains unchanged after the introduction of Ce and/or W. The results of NH₃-SCR investigation demonstrate that NO_x conversion over Ce–W/α-Fe₂O₃ is more than 85% at 300 °C, which is much higher than that over Ce/α-Fe₂O₃ and α-Fe₂O₃. Our studies illustrate that the addition of Ce can significantly increase the amount of surface oxygen vacancies as well as sites of moderate basicity. On the other hand, the addition of W can obviously decrease the amount of basic sites and increase the number of Brønsted acid sites. The synergistic effect of Ce and W addition on balancing acidity/basicity properties accounts for the high activity of Ce₂₀W₁₀/α-Fe₂O₃ for NO_x removal at low temperatures. The study provides insight into the relationship between acidity/basicity properties and catalytic performance of Ce–W/α-Fe₂O₃ catalysts, which is beneficial to the design of high-performance NH₃-SCR catalyst for NO_x removal at low temperatures.     

Mechanism for the Reduction of Oxides in Copper-Smelting Slag under Blowing with CO–CO2 Gas Mixtures

Russian Journal of Non-Ferrous Metals - A mechanism is proposed for the joint reduction of oxides from multicomponent copper-smelting slag when they are blown with CO–CO2 gas mixtures and an...     

Increase in the efficiency of electric melting of pellets in an arc furnace with allowance for the energy effect of afterburning of carbon oxide in slag using fuel–oxygen burners

The problems of increasing the efficiency of electric steelmaking using fuel–oxygen burners to supply oxygen for the afterburning of effluent gases in an arc furnace are considered. The application of a new energy-saving regime based on a proposed technology of electric melting is shown to intensify the processes of slag formation, heating, and metal decarburization.     

Fluid–Solid Reaction Kinetics for Solids of Non-basic Geometries: Application of the Law of Additive Times in Combination with the Shape-Factor Method

Metallurgical and Materials Transactions B - Fluid–solid reactions often occur under the mixed rate control of chemical and mass transfer processes. The results of this work demonstrate that...     

Contact and Capillary Processes in Systems Promising for Brazing: Eutectic Melts of Niobium with Cobalt,Nickel, and Iron–Nonmetallic Al2O3–SiO2 and AlN–TiN Materials

Powder Metallurgy and Metal Ceramics - The contact and capillary processes that occur in the interaction of eutectic Nb melts containing Co, Ni, and Fe with Al2O3–SiO2 and AlN–TiN solid...