Mathematical model for a radioactive marker in silicide formation

A mathematical model is constructed to interpret the profiles of radioactive (^31)Si tracers in a computer simulation proposed by R. Pretorius and A. P. Botha [Thin Solid Films 91, 99 (1982)]. This model assumes that only Si moves in the silicide, that the Si moves interstitially and convectively, and that the moving Si can exchange sites with the stationary Si in the silicide lattice. An analytical solution of this model is given and confirms the published computer simulation data. However, it is shown that the model is physically inadequate. Solutions of another model which assumes that metal, instead of Si, is the moving species for silicide formation (either interstitially, or substitutionally, or both), with self-diffusion of (^31)Si in the silicide during silicide formation. Almost all the experimental data can be fitted by solutions of both models. These examples demonstrate that radioactive tracer experiments alone are insufficient to determine the moving species when a solid binary compound film forms by reaction of adjacent elemental layers. Both inert marker and tracer data are needed to identify the moving species and the mechanisms

Ledger Provision in Hog Marketing Contracts

Price-dependent loan agreements at low interest rates have sometimes been included in North American hog sector long-term marketing contracts. We show that a general form of this stipulation can be viewed as a hybrid between a forward rate agreement and a bundle of commodity spot options. In some cases, the provision amounts to a commodity swap. These observations provide an approach to valuing the provision. Historical data are used to estimate expected payouts to the producer under the contract feature.

Evaluating the Saskatchewan Short-Term Hog Loan Program

The Saskatchewan short-term hog loan program of 2002 provided a non-market credit line to participating hog producers. The repayment conditions for cash advances committed to by the provincial government depend on later hog prices, and so the program has derivative contract attributes. We model the contracts and use an estimated spot price stochastic process to establish summary statistics for producer benefits from the program.

ESFK 20-100 watt S-band amplifier Quarterly report

Electrostatically focused klystron tube modification

ESFK 20-100 watt S-band amplifier

Electrostatically focused klystron development for use in interplanetary spaceborne communication system

A structure marker study for Pd_2Si formation: Pd moves in epitaxial Pd_2Si

A sample with the configuration Si (111)/single crystalline Pd_2Si/polycrystalline Pd_2Si/Pd is used to study the dominant moving species during subsequent Pd_2Si formation by annealing at 275 °C. The interface between monocrystalline and polycrystalline Pd_2Si is used as a marker to monitor the dominant moving species. The result shows that Pd is the dominant moving species in the monocrystal

Synthesis of Style in Gabriel Faure\u27s Preludes for Piano

Gabriel Faure occupies an important position in the history of French music. Through his conscious rejection of the influences of German romanticism he was instrumental in the recovery of artis tic standards which are thought of as typically French— logic, clar ity, moderation, balance— qualities which link Faure to a long line of French classical tradition. His stature in this respect is indis putable. His importance as a transitional figure in the overall course of music history is less commonly recognized. Bridging the nineteenth and twentieth centuries, he synthesized a traditional, yet progressive, musical style. Faure\u27s Preludes for Piano are relatively late works which pro vide a clear view of his stylistic synthesis— a synthesis which is characterized by a remarkable conciseness of construction. An exami nation of his use of harmony, melody, texture, rhythm and form in the Preludes reveals elements of an evolving musical style. Such an examination also provides important implications for the performer. The importance of his work is not diminished by the fact that he will probably never be recognized as a major figure in the history of music. As a teacher he instilled in his students the high stan dards which permeated his compositional process. Faure intended that his music should enrich the lives of those who were open to it and in this respect he has been extremely successful

The prediction of antenatal and postnatal depression in a sample of Western Australian women

In Australia, the Edinburgh Postnatal Depression Scale (EPDS; Cox, Holden & Sagovsky, 1987) has been increasingly used to screen for antenatal depression prior to its evaluation on a sample of Australian pregnant women. Also, the identification of predictors associated with antenatal depression has been neglected relative to the research focus on postpartum depression. An aim of the study was to evaluate the antenatal screening properties of the EPDS against diagnoses of major depression with the Mini International Neuropsychiatric Interview (MINI; Sheehan eta!., 1998). The aims were also to develop predictive models of risk factors associated with antenatal depression as measured by: (a) diagnosis of major depression (MINI); (b) depressive symptoms (EPDS 2: 9); (c) depression false positive results (EPDS 2:9, but no MINI diagnosis of major depression); and (d) depression level (EPDS total score) in the antenatal and early postnatal period. The study was prospective in design, with 200 women enrolled from Western Australia\u27s largest public maternity hospital. An EPDS 2: 12 was identified to be optimum for the clinical screening of major depression at 32 weeks of pregnancy. The results from the different regression analyses showed that the strongest predictors of antenatal depression were: depression earlier in pregnancy, anxiety, stress, daily hassles, expectations of support, personality traits, and history variables. The findings were in support of routine screening for depression and anxiety during pregnancy, the effects of stress on mood, and the lesser importance of antenatal compared to postnatal variables in accounting for postpartum depression level

Improvement of thermally formed nickel silicide by ion irradiation

A significant improvement of the lateral uniformity of thermally formed Ni_(2)Si layers has been observed after low‐dose (10^(13)~3 × 10^(14) ion/cm^2) Xe irradiation of an As‐deposited Ni film. Measurements have also been made on samples that contained a thin impurity layer formed intentionally between the silicon substrate and the evaporated nickel film. The impurity layer was thick enough to prevent thermal silicide formation in unirradiated samples, but in irradiated samples, the silicide formation was not prevented. Similar results were obtained for As implantations. We attribute this effect to ion mixing of the interfacial layer. These results demonstrate that a low‐dose irradiation can render the process of silicide formation by thermal annealing more tolerant to interfacial impurities. The concept is of potential significance to VLSI technology