Fully silicided NiSi:Hf-LaAlO/sub 3//SG-GOI n-MOSFETs with high electron mobility

We have integrated the low work function NiSi:Hf gate on high-/spl kappa/ LaAlO/sub 3/ and on smart-cut Ge-on-insulator (SC-GOI) n-MOSFETs. At 1.4-nm equivalent oxide thickness, the NiSi:Hf-LaAlO/sub 3//SC-GOI n-MOSFET has comparable gate leakage current with the control Al gate on LaAlO/sub 3/-Si MOSFETs that is /spl sim/5 orders of magnitude lower than SiO/sub 2/. In addition, the LaAlO/sub 3//SC-GOI n-MOSFET with a metal-like fully NiSi:Hf gate has high peak electron mobility of 398 cm/sup 2//Vs and 1.7 times higher than LaAlO/sub 3/-Si devices.     

Influence of cerium content on the structure and magnetic behavior of Co-Fe-Cu-Ce permanent magnets

As part of a continuing program to understand and optimize the magnetic behavior of Co-Fe-Cu-Ce permanent magnet alloys, we have made studies on the alloy system Co3.5Fe0.5CuCexwith x in the range 0.8 to 1.2. An alloy of x = 1 had previously been studied in detail and found to have good permanent magnet properties. In the present work, it was found that when x > 1, the coercive force was increased while both the Curie temperature and saturation magnetization were decreased. However when x < 1, the coercive force tends to decrease while the Curie temperature and saturation magnetization increase. The increase in coercive force with increase in cerium content can be accounted for largely by the decrease in saturation magnetization. These results are in accord with a domain wall pinning mechanism. Scanning electron microscopy studies have shown that a major second phase in the low cerium alloys is low in copper as compared with the matrix. On the contrary, the copper content of the second phase in the high cerium alloys is larger than that in the matrix.     

Socioeconomic factors in relation to fetal growth in white infants

Over 1,200 white mothers who were delivered consecutively at this medical center were classified in four different socioeconomic classes according to family affluence and occupations of the heat of the household. The frequency of low-birth-weight infants was highest in the lowest socioeconomic class. The high incidence of LBW infants in the lowest socioeconiomic group was not affected by any significant increase in number of mothers with medical problems or medical complications of pregnancy; it was dependent on the large number of mothers who were involved in four specific practices, largely of their own choosing, including low-weight gains, cigarette smoking, use of certain drugs during pregnancy, and refraining from all prenatal care. Mothers in the four socioeconomic classes who were not involved with these four specific practices (smoking, etc.) and whose pregnancies were free of medical problems and complications had uniformly low incidences of LBW infants and the mean birth weights of their infants were uniformly high and not significantly different. Unfavorable outcome of pregnancy with respect to fetal growth in this study appeared to depend less directly on socioeconomic circumstances than on the four specific maternal practices listed above.     

On the conductivity of phosphoric acid electrolyte

The specific electric conductivity and viscosity of 7.5–100 wt% aqueous phosphoric acid electrolyte have been measured in the temperature range 25–200°C. The product of conductivity and viscosity was found to decrease exponentially with increasing temperature. This suggests that the electric conduction in phosphoric acid follows the Grotthus proton switching mechanism. The measured conductivity data were correlated by the following empirical equation: $$\begin{array}{*{20}c} {k\mu = {\rm A} exp [BT]}\\ {A = 702.7X^{1.5} - 1734.2X^2 + 1446.5X^{2.5} - 350.7X^3 }\\ {B = - 0.010163 + 0.011634X - 0.08313X^2 }\\ \end{array}$$ wherek is conductivity in mho cm^?1; μ is viscosity in centipoise;T is the absolute temperature in K; andX is mole fraction of phosphoric acid in the electrolyte. The standard deviation for the percentage difference between the calculated and experimental values of 188 data points was less than 7.5%.     

Synthesis and characterization of novel sulfobetaines derived from 2,4‐tolylene diisocyanate

Novel sulfobetaines were synthesized from two urethanes derived from 2,4‐tolylene diisocyanate (TDI) blocked with 2‐hydroxyethyl methacrylate (HEMA) and either N,N‐dimethylaminopropylamine (DMAPA) or N,N‐dimethylaminoethanolamine (DMAEA). The first‐stage reaction of TDI with HEMA was carried out in petroleum ether heterogeneously with the precipitation of the intermediate monoadduct product in the reaction solution. The second stage is a homogeneous reaction of the monoadduct with the blocking agent, DMAPA or DMAEA, in tetrahydrofuran (THF). In both reactions, an inhibitor, hydroquinone, and a catalyst, dibutyltin diacetate (DBDAc), were used. The tertiary amine urethanes were quaternized by 1,3‐propane sultone to form the two novel sulfobetaines. The results of the elemental analysis of those products along with their ¹H‐NMR and IR spectra indicated that these materials were, indeed, the compounds expected. The products dissolved in strongly polar organic solvents. The copolymerization of these two monomers with comonomers such as styrene, methyl methacrylate, acrylamide, and HEMA was investigated. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 82: 3447–3459, 2001     

The fate of methane in a claus plant reaction furnace

Experimental kinetic data are reported for key side reactions occurring in the front end [i. e. the reaction furnace (RF) and the waste heat boiler (WHB)] of modified Claus plants used for sulfur recovery from the sour gases evolved in the treatment of natural gas. An extensive experimental study was conducted in a high temperature tubular reactor system for two important homogenous gas‐phase reactions. Firstly, experiments were carried out to study the oxidation of hydrogen sulfide and methane mixtures in the presence of oxygen. Secondly, the reaction between methane and sulfur dioxide was investigated experimentally. These results showed that methane was much less competitive for oxygen than hydrogen sulfide. Hence, in a partially oxidizing environment of a RF, data showed that methane reacted significantly with other major sulfur containing species, as secondary reactions, to form COS and especially CS². This is highly problematic from an environmental point of view.