The System Bi2O,—B2O3

The phase diagram for the system Bi₂O₃-B₂O₃ has been determined experimentally. The melting point of Bi₂O₃ has been redetermined as 825° C with an estimated overall uncertainty of about ±3°C, and the molal heat of fusion of Bi₂O₃, calculated from the slope of the liquidus curve, is 2050 cal per mole. The system contains a body-centered cubic phase of approximate composition 12Bi₂O₃·B₂O₃, which melts incongruently at 632°C. Four congruently melting compounds exist in the system: 2Bi₂O₃· B₂O₃·5B₂O₃, Bi₂O₃·3B₂O₃, and Bi₂O₃·4B₂O₃, with melting points, respectively, of 675°, 722°, 708°, and 715°C. The Bi₂O₃·4B₂O₃ compound exhibits a sluggish transformation at 696°C. Compositions containing up to 97.5 wt% (85 mole %) Bi₂O₃ can be partly or totally quenched to glass. Indices of the quenched glasses are greater than 1.74. A region of liquid immiscibility extends at 709°C from almost pure B₂O₃ to 19.0 mole % Bi₂O₃. The extent of immiscibility theoretically calculated agrees with the experimentally determined value when 1.20 A is used for the ionic radius of Bi³⁺.     

A probabilistic measure for model purposiveness in identification for control

The question of whether the identified process model will lead to a stable closed loop is of practical relevance during iterative identification and controller design. It is known that, in the case of overly demanding closed-loop requirements, the model resulting from the iterative procedure might conflict with prior knowledge about the process. Nevertheless, in many cases the violation of the plausibility of the identified models does not necessarily violate its purposiveness. Therefore, it is a matter of practical importance to have a confident indication as to whether the given model will result in a stable closed-loop design or not. If not, the iterative identification and controller design should be stopped, that is more appropriate model structures should be chosen. In this paper, a probabilistic measure is proposed which relies on the estimated model error obtainable by the stochastic embedding technique. The idea behind it is to estimate the probability that the critical point ( -1,0) will not be encircled by the Nyquist curve of the return ratio transfer function of the true system. The results obtained from experiments on a motor-generator laboratory set-up show that the proposed probabilistic measure provides a reliable indication of the stability of the designed closed loop.     

Stability criteria for control systems with one non-linear element†

Liapunov functions are used to develop frequency domain criteria for a class of systems in which the given non–linear characteristic is bounded in both sector and slope. The criteria include the special case when order of numerator and denominator is equal in the linear transfer functions of the class of systems.     

WRITING THE RULES TO RANK THE CANDIDATES: EXAMINING THE IMPACT OF INSTANT‐RUNOFF VOTING ON RACIAL GROUP TURNOUT IN SAN FRANCISCO MAYORAL ELECTIONS

Instant‐runoff voting (IRV)—a relatively new electoral reform adopted in several cities in the United States—gives voters the option to rank‐order more than one candidate preference for each office. When no candidate initially obtains a majority of first choice votes, rank‐ordered preferences are used to “instantly” calculate a winner without requiring a separate runoff election. The impact of IRV on racial group voter turnout in urban elections has not previously been subject to rigorous analysis. Based on racial group interest theory, I argue that the complexity of IRV increases information costs and obscures racial group interests for voters. Analysis of precinct‐level racial group voter turnout rates in five San Francisco mayoral elections from 1995 to 2011 reveals a significant relationship between IRV and decreased turnout among Black and White voters. IRV exacerbates turnout disparities related to age and education in the population, but decreases the effect of income. The relationship between turnout and racial diversity is diminished among some groups.     

Enhancement of Ferroelectric Properties of Pb(Zr,Ti)O3 Films Grown by Metal-Organic Chemical Vapor Deposition on Noble-Alloy Bottom Electrodes

Pb(Zr,Ti)O₃ (PZT) films grown on Ir electrodes by a metal-organic chemical vapor deposition (MOCVD) have suffered from high leakage and rough surface. We sputtered Pt and Ir simultaneously onto Ti/SiO₂/Si substrates and formed Ir-Pt alloy bottom electrodes with various compositions. With an optimal composition of Ir and Pt, PZT films grown by MOCVD on this substrate showed smoother surface and suppressed leakage via the bottom interface. At the specific composition of Ir and Pt, two different phases seemed to be acquired. They constituted the electrodes and affected the PZT grain nucleation independently so that the grains with different origins grew and restrained the vicinal grains, and finally soothed the faceted-grain-formation. No fatigue was observed even in PZT on Ir-Pt alloy with much Pt content.     

贮烟仓库中苏云金芽孢杆菌对烟草甲的杀灭活性

为研究苏云金芽孢杆菌(Bt)防治贮烟害虫的可行性,从全国7个主要卷烟厂的不同贮烟仓库中采集到不同类型的样品521份,采用醋酸钠抑制选择法从其中的225份样品中分离获得Bt952株,其分布率为100%,检出率为43.19%,用其中600株的发酵液对2~3龄烟草甲幼虫进行了初步毒力测定。结果表明,有18株分离株对烟草甲幼虫具有较高的生物活性,药后9d烟草甲幼虫的校正死亡率均达73%以上。     

Flavor Characteristics of Lactic, Malic, Citric, and Acetic Acids at Various pH Levels

The objective of this study was, through the use of free-choice profiling, to determine flavor characteristics of four acids (citric, malic, lactic, acetic) and two acid blends (lactic/acetic 1:1 and 2:1) at three different pH levels (3.5, 4.5, 6.5) and at 0.2% (w/v). Research was conducted to explores flavor differences and similarities among common food acidulants. Generalized Procrustes Analysis was performed on free-choice profiling data, which resulted in three significant principal axes. The first principal axis was characterized by overall intensity and sourness, the second by vinegar and saltiness, and the third by astringency.     

Odor Analysis of Pinot Noir Wines from Grapes of Different Maturities by a Gas Chromatography-Olfactometry Technique (Osme)

Pinot noir character varies significantly with vintage and with maturity within a given vintage. Our objective was to use a gas chromatography-olfactometry technique (Osme) to compare odor profiles of Pinot noir wines from grapes harvested at different maturities, during 1987 and 1988. Odor profiles of Pinot noir wines from those years were very different from each other with only 4 odor-active peaks common to both vintages. Wines made with grapes harvested at the end of the ripening period had more odor-active peaks than wines from earlier harvested fruit. The 1988 wines had more odor-active peaks than the 1987 wines.     

SEASONAL VARIABILITY OF CHEDDAR CHEESE WHEY POWDER: A CASE STUDY

Cheddar whey powder from one plant was evaluated for variations in quality parameters over 12 months. Representative samples were analyzed monthly for microbiological, physicochemical and sensory properties. The seasonal variability in the physicochemical properties was minor. Fall samples were higher in Hunter Lab parameter L* (lightness) and pH but lower in solubility index. Summer samples were high in solubility index and titratable acidity but low in L*. May production was significantly higher in standard plate count (SPC) and free moisture than the rest of the year. February production was significantly lower in SPC and free moisture content. There were no significant differences in aroma and flavor across the seasons. The flavor was generally bland, with the most intense attribute rating 5 on the 15‐point intensity scale. The order of intensity of the most intense attributes was cooked flavor and aroma > sweetness > caramelized flavor and aroma.