Measurement of carrier transport and recombination parameter in heavily doped silicon

The minority carrier transport and recombination parameters in heavily doped bulk silicon were measured. Both Si:P and Si:B with bulk dopings from 10 to the 17th and 10 to the 20th power/cu cm were studied. It is shown that three parameters characterize transport in bulk heavily doped Si: the minority carrier lifetime tau, the minority carrier mobility mu, and the equilibrium minority carrier density of n sub 0 and p sub 0 (in p-type and n-type Si respectively.) However, dc current-voltage measurements can never measure all three of these parameters, and some ac or time-transient experiment is required to obtain the values of these parameters as a function of dopant density. Using both dc electrical measurements on bipolar transitors with heavily doped base regions and transients optical measurements on heavily doped bulk and epitaxially grown samples, lifetime, mobility, and bandgap narrowing were measured as a function of both p and n type dopant densities. Best fits of minority carrier mobility, bandgap narrowing and lifetime as a function of doping density (in the heavily doped range) were constructed to allow accurate modeling of minority carrier transport in heavily doped Si

Heavy-Quark Hybrid Mass Splittings: Hyperfine and "Ultrafine"

It is argued that the heavy-quark limit of QCD requires a certain combination of hyperfine mass splittings in heavy-quark hybrid-meson multiplets to be unusually small. This observation will assist in the exploration of the heavy-quark hybrid spectrum at facilities such as PANDA. Alternatively, a large measured value for this mass splitting indicates that at least one member of the multiplet must contain significant light-quark degrees of freedom.Comment: Version to appear in Few-Body Systems. Substantial modifications from previous version, including extensive additional references and an expanded discussion of relevant operators. 7 page

Duty Performance of Vocational Guidance Counselors

It appeared to the author from reviewing the proposed Washington State Standards that perhaps the quality and guidance functions recommended by the Panel and adopted by the Vocational Education Act, to be available to students, were not being met by the counselors qualifying under the variety of requirements available to Washington State counselors. More specifically, it appeared that counselors being certified under a particular set of requirements would tend to perform a particular stage of counseling more successfully due to the experiences required for certification. The problem as viewed by the author is that the variety of criteria available for certification overshadows the efficacy of a single certificate. It appeared that fulfillment of one set of requirements does not imply success in all stages of counseling

Prediction and simulation using simple models characterized by nonstationarity and seasonality

In this paper, we provide new evidence on the empirical usefulness of various simple seasonal models, and underscore the importance of carefully designing criteria by which one judges alternative models. In particular, we underscore the importance of both choice of forecast or simulation horizon and choice between minimizing point or distribution based loss measures. Our empirical analysis centers around the implementation of a series of simulation and prediction experiments, as well as a discussion of the stochastic properties of seasonal unit root models. Our prediction experiments are based on analysis of a group of 14 variables have been chosen to closely mimic the set of indicators used by the Federal Reserve to help in setting U.S. monetary policy, and our simulation experiments are based on a comparison of simulated and historical distributions of said variables using the testing approach of Corradi and Swanson (2007a). A key impetus for this paper stems from the fact that various financial service companies routinely create economic scenario, whereby seasonal and nonstationary financial and economic variables such as those examined here are simulated (and predicted) using relatively simple time series models. These economic scenarios are subsequently used in risk management and asset allocation, as is often mandated by various world financial regulatory authorities. Our findings suggest that a simple version of the seasonal unit root (SUR) model performs very well for predicting 8 of 14 variables, when the forecast horizon is 1-step ahead. However, for horizons of greater than one-step ahead, our SUR model perform poorly when used for prediction, suggesting that parameter estimation error is crucial to understanding the empirical performance of such models. This parameter estimation error result is confirmed via a series of Monte Carlo experiments. Simulation experiments yield similar conclusions, although SUR models in this case are useful for constructing forward conditional distributions at 1- and 3-step ahead horizons. Interestingly, simple periodic autoregressions do not have this property, and are found to perform very well in both prediction and simulation experiments, at all horizons up to 60 months ahead

Environment assisted degradation mechanisms in advanced light metals

The general goals of the research program are to characterize alloy behavior quantitatively and to develop predictive mechanisms for environmental failure modes. Successes in this regard will provide the basis for metallurgical optimization of alloy performance, for chemical control of aggressive environments, and for engineering life prediction with damage tolerance and long term reliability

The effects of climate risk on hydropower P3 contract value: Preliminary study of the Inga 3 Dam

Large hydropower dams are at the centre of a debate weighing the value and costs of renewable energy against the risks of climate change. The debate is especially relevant on the African continent, which offers vast hydropower potential, but which is exposed to possible climatic changes. This paper presents one possible framework for analysing, valuing, and mitigating the possible impacts of climate change on investment returns. It applies the framework to the proposed series of Inga projects. We find that project concessions can recapture value by phasing dam build-out. Our optionality framework can help structure P3 contracts to improve hydropower project value as well as insure sponsors against climate risk

Conrad Specialty Roofing

I know it’s hard to believe, Allen, but Max is dying,” said Bill Levis, as he paced about the cramped, dingy office of Conrad Specialty Roofing (CSR). “He and I were partners for 15 years and friends for a lot longer than that. Mary and his kids are devastated; hell, he’s only 50 years old. I don’t know how she’s going to get through this – you know what kind of person she is.”Yes, I know what kind of person she is, thought Allen. She’s worked in this office for the past four years, if you could describe what she did as work. In addition to successfully building CSR for the past five years, Max had always taken care of Mary and the children, made even the smallest decisions for them. And now he’s going to be leaving them on their own… He’s going to be leaving me on my own, too, Allen’s thoughts continued. “ This certainly explains Max’s odd behavior over the last few months” said Allen, shaking his head.  “He’s pretty much put me in charge of everything lately – sales, supervision, ordering material, paying bills, the works. He hired me last year as a project manager, but he’s been around here so little I feel like the owner.”                 “That’s good,” replied Bill, “because it looks like you are going to be the owner. When I saw Max yesterday, he told me how proud he was of the way you took up the slack and kept the business going smoothly over the past six months. He told me that he wanted you to own CSR and was going to see his lawyer to put something about it in his will. I agreed with him, possibly for the first time since we split up our partnership five years ago; you have really been a lifesaver for this business – without you, it would have been doomed, just like Max… You are CSR, you know.”                 “Now all we need to do is arrange something equitable with Mary,” continued Bill. “I’ve known her so long… perhaps I can help.

The Decline of the Non-Hispanic White Population in the United States of America

Objectives: The question of a declining non-Hispanic white (NHW) population has sparked debate in the United States. In examining this question, three bodies of research have emerged. One group reports that the decline is real, a second argues that it is an illusion, and the third provides evidence that the decline is concentrated within socio-economic segments of the NHW population. We use the third groups’ insight as the starting point for our research objective. Methods: In conjunction with data from Census Bureau sources, we use a series of Regression Models in this inquiry. Results: Our results show that the decline of the NHW population is real and related to factors embedded in the institutional anomie theory (IAT) framework. Conclusions: We conclude that the IAT framework is a suitable approach for examining the question of NHW population decline. However, we suggest that future research consider refining our approach by: (1) using sub-state areas as the units of analyses; (2) examining changes in the NHW population relative to lagged changes in the IAT framework at both the state and sub-state levels; (3) placing our framework into an “algorithmic modeling approach” that employs machine learning; and (4) developing anomie predictors