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Several representative examples of nonlinear electronic circuits modeled by discontinuous 1-dimensional maps, including the 1-D maps derived from Chua's circuit, are reviewed. Although very little general results are presently available for studying the chaotic dynamics of such 1-D maps, an important subclass C where useful properties are known is identified and reviewed. This subclass is characterized by monotonic expansive maps within each continuous subinterval, and where the map assumes at each discontinuity point a left and a right limit equal in value to the boundary (end points) of the defining interval I. The main property characterizing discontinuous maps belonging to class C is that they possess a "good" invariant measure, which can be translated roughly by saying the associated chaotic attractor can be proved rigorously to be ergodic.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">></ETX>
Kinetic isotope effects of atom-transfer reactions and their temperature dependences at high temperatures have been calculated for various hydrogen-atom–formaldehyde reactions. In the case of the “abstracting atom” kinetic isotope effect, a negative temperature coefficient is predicted in the high-temperature limit. The theoretical calculations are compared with experimental results in the literature and satisfactory agreement is obtained.
We show that Supernova (SN) 2002kg in NGC 2403, initially classified as Type II-narrow (IIn), has photometric and spectroscopic properties unlike those of normal SNe. Its behavior, instead, is more typical of highly massive stars which experience the short-lived luminous blue variable (LBV) phase toward the end of their lives. The star, in fact, most resembles the LBV S Doradus in outburst. The precursor of SN 2002kg is the irregular, bright blue variable star 37 (V37), catalogued by Tammann & Sandage in 1968. Using high-quality ground-based, multi-band images we can constrain the initial mass of V37 to be M_ini >~ 40 M_sun. We find that, although the spectra indicate a nitrogen enhancement, possibly revealing the products of CNO processing by V37 in the ejecta, the star lacks a substantial LBV nebula. The outburst from SN 2002kg/V37 is not nearly as energetic as the giant eruptions of the eta Carinae-like variables, such as SN 1954J/V12, also in NGC 2403. SN 2002kg/V37, however, is among a growing number of ``SN impostors'' exhibiting a broad range of outburst energetics during a pre-SN phase of massive-star evolution.
In the early 1990s, Mayor Rudolph Giuliani launched a zero-tolerance campaign aimed at street disorders and petty offenders, incarnated in the infamous squeegee man. New York City soon became a planetary showcase for an aggressive approach to law enforcement that, despite its extravagant costs and the absence of connection to the crime drop, came to be admired and imitated by other cities in the United States, Western Europe, and Latin America. In Prisons of Poverty, Loic Wacquant tracks the incubation and internationalization of the slogans, theories, and measures composing this new punitive common sense, fashioned to curb mounting urban inequality and marginality in the metropolis. He finds that a network of Reagan-era conservative think tanks (led by the Manhattan Institute) forged them as weapons in their crusade to dismantle the welfare state and, in effect, to criminalize poverty. He traces their import and export through the agency of the media and the pro-market policy institutes that have mushroomed across the European Union, particularly in Tony Blair's Britain. And he shows how local academics helped smuggle U.S. techniques of penalization into their countries by dressing them up in scholarly garb. Now available in English for the first time in an expanded edition, Prisons of Poverty reveals how the Washington consensus on economic deregulation and welfare retrenchment was extended to encompass punitive crime control because the invisible hand of the market necessitates and calls forth the iron fist of the penal state.
Abstract. The effect of photoinhibition on the activity of photosystem II (PSII) in spinach chloroplasts was investigated. Direct light‐induced absorbance change measurements at 320 nm (Δ A 320 ) provided a measure of the PSII charge separation reaction and revealed that photoinhibition prevented the stable photoreduction of the primary quinone acceptor Q A . Sensitivity to photoinhibition was substantially enhanced by treatment of thylakoids with NH 2 OH which extracts manganese from the H 2 O‐splitting enzyme and prevents electron donation to the reaction centre. Incubation with 3‐(3,4,‐dichlorophenyl)‐1,1‐dimethylurea (DCMU) during light exposure did not affect the extent of photoinhibitory damage. The chlorophyll (Chl) b ‐less chlorina (2 mutant of barley displayed a significantly smaller light‐harvesting antenna size of PSII (about 20% of that in wild type chloroplasts) and, simultaneously, a lower sensitivity to photoinhibition. These observations suggest that photoinhibition depends on the amount of light absorbed by PSII and that the process of photoinhibition is accelerated when electron donation to the reaction centre is prevented. It is postulated that the probability of photoinhibition is greater when excitation energy is trapped by P680 + , the oxidized form of the PSII reaction centre. The results are discussed in terms of the D1/D2 heterodimer which contains the functional PSII components P680, pheophytin, Q A and Q B .
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTAnalysis of the design of bubble-column reactors for Fischer-Tropsch synthesisDavid Stern, Alexis T. Bell, and Heinz HeinemannCite this: Ind. Eng. Chem. Process Des. Dev. 1985, 24, 4, 1213–1219Publication Date (Print):October 1, 1985Publication History Published online1 May 2002Published inissue 1 October 1985https://pubs.acs.org/doi/10.1021/i200031a053https://doi.org/10.1021/i200031a053research-articleACS PublicationsRequest reuse permissionsArticle Views227Altmetric-Citations12LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InRedditEmail Other access options Get e-Alerts
