Global Environmental Change: Management Under Long-range Uncertainty

This paper gives an overview of social science challenges in global environmental research. After a sketch of backgrounds, the ‘social dilemma’ is introduced as a major research question. It is asserted that current uncertainties over global environmental change provoke innovative studies on risk behaviour and management of long-range, largely unpredictable, phenomena. Various illustrations of new research initiatives and directions are given.     

Applications of Telos

EuLisp has an integrated object system with reflective capabilities. We discuss some example applications which use these facilities to experiment with some advanced and powerful concepts, namely, finalization, virtual shared memory and persistence. A secondary goal is to attempt to illustrate the additional possibilities of metaobject programming over non-metalevel techniques.     

Computer interface design: A user-centered approach

Enhancing the way people use computers to perform tasks has become a very important issue in interface design and human-computer interactions. When the concept of human-computer interaction first began to emerge it was commonly understood as the hardware and software through which a human and computer could effectively communicate (Laurel, 1990). This effective communication is also know as user-friendliness. The concept of user friendliness has recently been expanded to include various attributes and cognitive aspects of the user's needs and experiences. Focus should be on the user's experiences, expectations, preferences, and cognitive aspects in developing efficient and effective computer interface designs. It is the basic premise of this paper to emphasize using a user-centered design in developing computer interfaces.     

Deorthogonalization of ODS-CDMA QPSK by AM/PM Nonlinearity

When using a conventional demodulator, a sufficient condition to maintain ODS-CDMA codeword orthogonality is constant relative channel amplitude over the codeword duration. When transmitted over a memoryless, AM/PM nonlinearity channel, the chip-to-chip fluctuating amplitude of a composite ODS-CDMA QPSK waveform produces a chip-to-chip fluctuating phase that deorthogonalizes the ODS-CDMA codewords, resulting in an additional multiple access self-interference similar to that found in asynchronous DS-CDMA. For ODS-CDMA QPSK in an AM/PM nonlinearity channel, we utilize the Central Limit Theorem, derive, and evaluate: (i) an expression for the signal-to-distortion ratio at the demodulator output, (ii) an expression for the uncoded bit error probability, and (iii) an upper bound on the convolutionally-coded bit error probability. We find that the degradation to BER depends on both the AM/PM nonlinearity slope and the ODS-CDMA channel loading.     

Thermoreversible Gelcasting: A Novel Ceramic Processing Technique

A new ceramic processing method, thermoreversible gelcasting (TRG), has been developed. The method uses a gelation process that can be reversed multiple times. Two Al₂O₃ systems have been explored with the use of a specific triblock copolymer to form a binding gel network. The mixture becomes a free-flowing liquid on heating above 60°C. However, on cooling below 60°C, the slurry instantaneously transforms to a physical gel. This process can be reversed easily (essentially with an infinite processing time window) while the solvent is present in the system, which is advantageous when trying to produce high-quality dense pieces if initial casting irregularities occur. Near-theoretically dense specimens have been produced with properties consistent with reported values of high-density Al₂O₃.     

Treatment with alendronate prevents fractures in women at highest risk: results from the Fracture Intervention Trial

BACKGROUND: The efficacy of antiresorptive therapy in preventing fractures in women at highest fracture risk, such as very elderly women or those with severe osteoporosis, is uncertain. PARTICIPANTS AND METHODS: Using data from a double-blind, randomized, placebo-controlled clinical trial that enrolled 2027 postmenopausal women aged 55 to 81 years with low femoral neck bone mineral density (BMD) and existing vertebral fractures, we examined the consistency of the effect of treatment with alendronate sodium in preventing fractures within a priori-specified risk subgroups defined at baseline by age, bone density, number of preexisting vertebral fractures, and history of postmenopausal fracture. The women were randomized to oral administration of alendronate or placebo and followed up for an average of 2.9 years. The initial dose of alendronate sodium was 5 mg/d; the dosage was increased from 5 to 10 mg/d at 24 months. New vertebral fractures, the primary end point of this arm of the trial, were defined by morphometry as a decrease of 20% and at least 4 mm in any vertebral height between baseline and a follow-up radiograph at 36 months. Incident clinical fractures, the secondary end point, included nonspine and clinical (symptomatic) vertebral fractures. All clinical fractures were confirmed with x-ray film reports or, in the case of clinical vertebral fractures, x-ray films. RESULTS: Overall, there was a 47% significant reduction in risk of new vertebral fractures in the alendronate group compared with the placebo group. The reduction in risk of new vertebral fracture was consistent across fracture risk categories including age (relative risk [RR], 0.49 in women < 75 years compared with 0.62 in those > or = 75 years), BMD (RR, 0.54 in women with a femoral neck BMD < 0.59 g/cm2 [median] compared with 0.53 in those with a BMD > or = 0.59 g/cm2), and number of preexisting vertebral fractures (RR, 0.58 in women with 1 vertebral fracture compared with 0.52 in those with > or = 2). The overall significant 28% reduction in risk of incident clinical fractures in the alendronate group compared with the placebo group was also observed within these subgroups. Compared with the number of lower-risk women, a similar or smaller number of high-risk women needed to be treated to prevent 1 fracture. For example, 8 women aged 75 years or older compared with 9 women younger than 75 years, or 4 women with 2 or more existing vertebral fractures compared with 16 women with 1 existing vertebral fracture, needed to be treated with alendronate for 5 years to prevent 1 new vertebral fracture. CONCLUSIONS: Alendronate effectively reduces fracture risk in postmenopausal women with vertebral fractures and low BMD, including those women at highest risk because of advanced age or severe osteoporosis. Since the risk reductions observed with alendronate treatment were consistent within fracture risk categories, more fractures were prevented by treating women at highest risk.     

Effects of category prototypes on performance-rating accuracy.

Two studies examined whether the accessibility of performance prototypes influences performance appraisals. Pilot studies revealed students used performance prototypes when rating instructor performance. Study 1 manipulated the accessibility of these prototypes and the time delay of performance ratings. Results showed no effect of the prime on rating error and accuracy; however, discrimination accuracy decreased over time and recognition bias became more conservative. Study 2 manipulated prototype accessibility and type of rating stimuli (videotape vs. vignette). Rating accuracy and recall were higher for vignette than videotape stimuli, and only those participants exposed to the vignette exhibited priming effects. Results supported transfer-appropriate processing and implied that cognitive primes may have a stronger effect on performance ratings based on "paper-people" than videotaped stimuli. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Electrical Characterization of p-Type Pb1−x Eu x Te

The transport properties of p-type Pb_1?x Eu _x Te epitaxial layers were studied as a function of Eu content, temperature, and magnetic field. The low-temperature hole mobility is drastically reduced when the Eu concentration is increased from 0 to 6%, while the hole concentration remains almost constant. A metal-insulator transition was observed for x ≈ 0.04, which is probably induced by the disorder caused by the introduction of Eu. For temperatures down to 10 K, only positive magnetoresistance has been observed at low magnetic fields. An anomalous behavior of the resistivity as a function of temperature has been detected for a Eu content about 5%, which is attributed to the resonance between the localized Eu 4f level and the valence band maximum.     

Dusts,scale, slags,sludges... Not wastes,but sources of profits

Historically, the steel industry has focused on the need for and the many benefits of recycling steel that is discarded either in its own or in its customers’ manufacturing processes, as well as in recovery and reuse of steel scrap that arises after the product has served its intended purpose. In fact, modern steelmaking relies on the use of recycled iron units for at least half of its production. The other side of the story is the fate of the non-steel by-products (e.g., oxide dusts, sludges, scales, slags, spent refractories and the contained “low grade” energy units that are generated as natural adjuncts to iron and steelmaking processes). These valuable by-products often are classified as “wastes” and are discarded to landfills, at significant cost, although in reality they offer significant potential for cost savings or profit if reintroduced into the industrial arena via well planned programs. Examples of such instances will be presented, including energy credit issues, in the hope of pointing the way for future expansion of benefits from these opportunities. Preparing for a challenge and honor such as the Howe Memorial Lecture, one has to stand in awe of the accomplishments of the predecessor we honor in this forum. He worked in the early days of our industry without the benefits of the many technological improvements he and his successors brought to play as the years went by. John Stubbles, in his Howe Memorial Lecture in 1997,_[1] presented a masterful and entertaining biography of Howe and his very active and prolific life. Perhaps the most telling quotation he attributed to Howe is very pertinent to the topic we will address presently: “Metallurgy lives by profit, not logic,” to which I would like to add a comment that bears on the topic of this lecture from the 1991 Howe lecturer, my friend and mentor Bill Dennis, “Where there is muck, there is money.” There are numerous examples of “one hand washes the other” in this business; that is, of the synergism between needs and capabilities. We will address some of these situations, such as in a new process under development for dezincing of post consumer scrap, and in the use of iron units in by-product oxides and recycling of ladle slags and of spent refractories. Peter J. Koros, the Iron and Steel Society’s 77th Howe Memorial Lecturer (2001), is Principal of Koros Associates, Inc. (Pittsburgh, PA), a consultancy he founded following retirement from the former LTV Steel Company where he worked for nearly 41 years, retiring as Senior Research Consultant. He earned the Bachelor of Science degree in Metallurgical Engineering from Drexel University, and his master’s and doctoral degrees in Metallurgy from the Massachusetts Institute of Technology (MIT). In 1958, he joined Jones and Laughlin Steel (which became LTV Steel Company), where he held positions in research (Director, Process Metallurgy), Technical Services and Quality Control, with most activities focused on steelmaking and related areas. He was responsible for J&L’s development work in injection technology for desulfurization of hot metal and steel, was the inventor of the patented co-injection concept now in use worldwide, and had the lead role in LTV Steel’s programs for degalvanizing scrap and for recovery and utilization of by-product oxides. He led the AISI Opt-In program for degalvanizing scrap and the LTV-USS pilot program for processing “by-product” oxides. Koros has authored more than 75 publications and presentations, and holds eight U.S. patents, the latest issued in 2000. Dr. Koros was elected a Distinguished Member and Fellow of the ISS in 1984 and a Fellow of ASM International in 1988. Other honors include the ISS Distinguished Service Award (1998), ISS Electric Furnace Honorable Mention Citation (1987), International Magnesium Association Design and Applications Award (1978), AISI Gold (1977) and Silver (1969) Medals, ISS Herty (1963), McKune (1963), and Toy (1962) Awards. Koros served on the Technical Advisory Committee of the AISI-DOE Direct Steelmaking Program and its follow-on Waste Oxide Recycling Program. He was chairman of the AISI Task Force on Degalvanizing Steel Scrap and of the Industrial Advisory Panel to the Argonne Lab-MRI Program on Dezincing Steel Scrap. The 2001 Howe Memorial Lecture, titled “Dusts, Scale, Slags, Sludges ... Not Wastes But Sources of Profits,” as well as an invited Keynote Lecture for an International Recycling Conference in Sweden (June 2002, “Iron Units in Search of a Home: New Steel”) were based on the experience from these programs. Koros has been an active member of the ISS Advanced Technology Committee for which he participated in and chaired several symposia, including New Melting Technologies II (October 2002) and the first New Melting Technologies Symposium (1997). He was Director of the ISS 2000 Short Course on Injection Technology, a lecturer in the 2000 ISS/AISI Course on BOF Steelmaking, lead Co-chairman for the Elliott Symposium (1990), and Chairman of the Program Committee for the Fifth International Iron and Steel Congress (1986). Dr. Koros served on the Industrial Advisory Board of MIT’s Materials Processing Center (1995–98) and the AISI’s Iron and Steel Research Subcommittee (1976–86.) He was chairman of the ISS National Science Foundation Advisory Committee, the Advisory Council of the U.S. Bureau of Mines Generic Minerals Technology Center for Pyrometallurgy Research (1983–85), and of the Advisory Board for Carnegie Mellon University’s Center for Iron and Steel Research, for which he served as chairman (1991–1992). Service included participation in the NRC-NAS Alternative Energy and Development Strategy Study (1989–90.) Koros was very active in the creation of the ISS, having served as Chairman of the predecessor TMS Iron and Steel Division in 1972–73 and on the AIME Board of Directors (1974). Professional Society memberships: ISS (elected Distinguished Member and Fellow, Life Member), TMS (Senior or Life Member), ASM International (elected Fellow, Life Member), and AISE.