Optimal control of an aluminum casting furnace: Part I. The control model

This is a series of two articles on the control of an aluminum casting furnace to bring a mass of liquid aluminum from a known initial temperature to a desired final temperature in a given time with minimal fuel cost. An analytic model of the furnace already exists but is too complex for control purposes. Here in Part I, a simplified nonlinear control model is derived from the analytic model. In Part II, an optimization of the fuel flow is performed on the control model using Pontryagin’s maximum principle. The first article shows that despite the complexity of the analytic model, a tenth-order nonlinear control model with good representativity can be obtained. The second article shows that the maximum principle applied to this problem leads to a solution with optimal fuel cost. If modeling industrial processes is a complex problem in itself, obtaining a control model therefrom is just as delicate. This series of articles proposes an approach that works for the casting furnace and is indeed applicable to other industrial processes as well. In the existing analytic model, the casting furnace is treated as two one-dimensional conducting media (metal and refractories), while its chamber is seen as a well-stirred reactor. In this article, a control model is derived therefrom by a statistical method. The analytic model is run several times to obtain a set of predicted data on which a least-squares approximation is performed to determine the best parameter values to be used for the control model equations. The conduction equations in the two media are linear. The expressions for heat generation in the chamber and for radiative-convective heat transfer from the chamber to the two media are nonlinear and are kept to ensure maximum representativity. The result is a highly representative tenth-order control model, the degree of representativity being assessed by comparing the temperature outputs and the energy balances obtained from the analytic model with those obtained from the control model.     

Birth of an initiative

Dnepropetrovsk Regional Trade Union. Translated from Metallurg, No. 11, pp. 23–25, November, 1989.     

Birth control in the world

There are an estimated 120-150 million contraception users in the world, i.e. 30-35% of couples in fertile age. About 40-45 million utilize the pill, 33-40 million have been sterilized, especially in China, India, and the US, 20-25 million use the condom, especially in Japan, 10-15 million still use behavioral methods, and about 3 million recur to spermicidal agents. Abortion as a contraceptive measure is used mostly in Russia, with 8-13 million abortions a year, in the communist block countries, in the U.S., in Japan, in China, with 20 million abortions a year, and in India. There may be a total of about 50 million legal abortions a year world wide. Modern contraceptive methods are widely used, except in Latin America and in Africa. It must be remembered that all figures must be interpreted very carefully, especially those coming from communist countries.     

计划生育避孕药具发放和管理探讨

目的:探讨计划生育药具发放和管理措施.方法:分析新形势下计划生育避孕药具管理工作和发放过程管理;分析在药具应用过程中的康检工作实施方法.结果:根据计划生育避孕工作需要,首先要保证药具质量,对药具实施规范化管理;改进发放模式,实施统一化管理;加强药具随访工作,做好康检服务;建立药具和康检管理目标责任制,实施责任化管理制度.结论:新形势下的计划生育避孕药具管理和方法工作要实施规范化管理模式,要在实施过程中做好随访工作和康检工作,这样有助于提高避孕药具管理工作和实施效果.     

Identity and resurrective ideology in an age of trauma.

The author extends his conception of emotional trauma as a shattering of the tranquilizing “absolutisms of everyday life” that shield us from our finitude and our existential vulnerability, to a consideration of collective trauma. Using the collective trauma of 9/11 and its aftermath as his prime example, he illustrates how traumatized people fall prey to “resurrective ideologies” that promise to restore the sheltering illusions that have been lost. He suggests that an alternative to these grandiose illusions can be found in our “kinship-in-finitude.” (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Birth order and an experimental study of empathy.

104 Ss in all, divided into groups of 6, had the opportunity of empathizing with the assumed anxiety of 1 of their number with whom they had interacted. The critical S was placed in a test situation and in ? of the cases performed poorly and in the other ? very well. The palmar sweating of the other Ss was measured during the test performance and their reports on their own feelings of anxiety were obtained. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Freedom and voluntary death: suicide as ideology

Voices have been increasing in the last years, demanding the right of men to choose time and way of ending his life, thus asking consequently the liberty for mankind of killing themselves. The most important of these ideas are explained in connection with their philosophical, psychological and sociological background and confronted with the results of modern suicide research. The outcome of this review gives, however, no reason for changes in the previous and successful ways of suicide prevention.     

Professional ideology: A response to a critique.

The present author responds to the article by J. Stubbins (see record 1985-31779-001) on rehabilitation services as ideology by providing an analysis of historical and philosophical bases of disability policies. It is posited that socioeconomic forces have influenced rehabilitation services' focus upon the individual client and that their impact persists despite evidence of the ineffectiveness of this approach. It is suggested that what Stubbins says could be valid for all human-service programs. (7 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Serratia odorifera biogroup I: an emerging pathogen

Gram-negative bacteremia is a common cause of infection in hospitalized patients. Serratia sepsis is known to cause clinically significant morbidity and mortality. The most common species involved is Serratia marcescens. Clinicians have been uncertain as to the role of Serratia odorifera biogroup 1 as a human pathogen because most isolates have not been associated with invasive disease. In previous publications, 12 cases have been described in which S odorifera biogroup 1 caused sepsis. These observations verify the organism's role as a human pathogen.     

Political ideology and science: A reply to Eysenck.

Comments on an article by H. J. Eysenck (1982) in which he suggested that Marx, Engels, and Lenin failed to support environmentalism. It is contended that Eysenck ignored the overwhelming evidence of radical environmentalism in Marxist theory. (10 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Transformation-toughening in cemented carbides: Part I. Binder composition control

Successful application of “transformation-toughening” to cemented carbides is demonstrated in the system WC-(Fe, Ni, C). Strict control of the chemical composition of the binder and careful consideration to the effects of thermal residual stress and the constraint imposed by the surrounding carbide grains are essential for achieving the desired degree of metastability of the binder phase that can lead to enhancements in the hardness/fracture toughness behavior of this class of cemented carbides. Formerly Manager, Research-Development, Reed Tool Company, Houston, TX.     

Isothermal fatigue of an aluminide-coated single-crystal superalloy: Part I

The isothermal fatigue behavior of a high-activity aluminide-coated single-crystal superalloy was studied in air at test temperatures of 600 °, 800 °, and 1000 °. Tests were performed using cylindrical specimens under strain control at ≈0.25 Hz; total strain ranges from 0.5 to 1.6 pct were investigated. At 600 °, crack initiation occurred at brittle coating cracks, which led to a significant reduction in fatigue life compared to the uncoated alloy. Fatigue cracks grew from the brittle coating cracks initially in a stage II manner with a subsequent transition to crystallographic stage I fatigue. At 800 ° and 1000 °, the coating failed quickly by a fatigue process due to the drastic reduction in strength above 750 °, the ductile-brittle transition temperature. These cracks were arrested or slowed by oxidation at the coating-substrate interface and only led to a detriment in life relative to the uncoated material for total strain ranges of 1.2 pct and above 800 °. The presence of the coating was beneficial at 800 ° for total strain ranges less than 1.2 pct. No effect of the coating was observed at 1000 °. Crack growth in the substrate at 800 ° was similar to 600 °; at 1000 °, greater plasticity and oxidation were observed and cracks grew exclusively in a stage II manner. Formerly Research Student, Department of Materials Science and Metallurgy, University of Cambridge. Formerly Lecturer, Department of Materials Science and Metallurgy, University of Cambridge CB2 3QZ, United Kingdom.     

On the malleability of ideology: Motivated construals of color blindness.

The authors propose that the content of certain sociopolitical ideologies can be shaped by individuals in ways that satisfy their social motivations. This notion was tested in the context of color-blind ideology. Color blindness, when construed as a principle of distributive justice, is an egalitarian stance concerned with reducing discrepancies between groups' outcomes; as a principle of procedural justice, however, color blindness can function as a legitimizing ideology that entrenches existing inequalities. In Study 1, White people high in antiegalitarian sentiment were found to shift their construal of color blindness from a distributive to a procedural principle when exposed to intergroup threat. In Studies 2, 3A, and 3B, the authors used manipulations and a measure of threat to show that antiegalitarian White people endorse color blindness to legitimize the racial status quo. In Study 3B, participants' endorsement of color-blind ideology was mediated by increases in their preference for equal treatment (i.e., procedural justice) as a response to threat. In the Discussion section, the authors examine implications of the present perspective for understanding the manner in which individuals compete over the meaning of crucial ideologies. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Birth order: Reconciling conflicting effects.

Secular trends in test scores are accurately predicted by trends in aggregate birth orders. The trend data contradict individual-difference analyses that show birth order as a poor predictor of individual test scores. This article demonstrates why the 2 formulations of the problem—the individually distributed birth order analysis and aggregate-pattern analysis—generate different results. A meaningful interpretation is given by the confluence model, a theory specifying the process whereby the intellectual environment modulates intellectual development. The authors introduce the concept of collective potentiation that specifies collective side effects of birth order. In contrast to genetic theories, the confluence model quantifies the differential environmental contributions to intellectual development of successive siblings, and it offers several well-confirmed derivations that genetic and other developmental theories cannot explain. (PsycINFO Database Record (c) 2010 APA, all rights reserved)