bluuebunny/crossref_metadata_2025_split huggingface dataset:
Die chemisch‐analytische Untersuchung von Bränden
Authors: Wichmann Hubertus , Richter Hans , Bahadir Müfit 
Published: May 2007

AbstractGESTEUERTE VERBRENNUNGEN in speziell konstruierten Anlagen stellen eine Grundlage unserer industriellen Entwicklung und unserer Zivilisation dar. Man denke beispielsweise an Verbrennungen in Kraftwerken, Abfallverbrennungsanlagen, Heizungsöfen oder Kraftfahrzeugmotoren: Durch eine optimale „Fahrweise”︁ der Anlagen unter den jeweils gegebenen Bedingungen, z.T. gekoppelt mit Abgasreinigungsverfahren, werden Verbrennungsvorgänge bei geringer Schadstoffemission zur Wärme‐ und Krafterzeugung bestmöglich genutztEine andere Dimension des Feuers, nämlich sein Zerstörungs‐ und Schadstofffreisetzungspotential, wird bei ungesteuerten Bränden häufig deutlich erkennbar. Trotz aller Umsicht sind Brandunglücke im Umfeld des Menschen unvermeidlich und zahlreich. Im Jahr 1996 mußten die Feuerwehren in Deutschland beispielsweise 243.791 Brände bekämpfen [1]. Im folgenden sollen eben diese ungesteuerten Brände und deren Potential zur Bildung und Freisetzung von umweltrelevanten Schadstoffen näher betrachtet werden.
Liesegangsche Ringe Ein faszinierendes Beispiel für räumliche Stukturbildung
Authors: Ducci Matthias , Müller Kathrin , Oetken Marco 
Published: May 2007

AbstractRAPHAEL EDUARD LIESEGANG machte im Jahre 1896 eine aufregende Entdeckung: Er beobachtete, daß das Auftropfen von Silbernitrat‐Lösung auf eine Gelatinefläche mit geringen Kaliumdichromatgehalt nicht zu einem gleichförmigen Silberchromat‐Niederschlag, sondern zur Ausbildung konzentrischer Ringe ‐ der Liesegangschen Ringe ‐ führt. Im folgenden wird neben diesem „klassischen”︁ Liesegang‐Experiment die Entstehung periodischer Schichten im Reagenzglas anhand eindrucksvoller Beispiele geschildert. So treten z. B. beim Eindiffundieren von Ammoniak‐Lösung in ein cobaltsalzhaltiges Gelatinegel wunderschöne blau‐grüne Cobalthydroxid‐Schichten auf, die sehr eng zusammen liegen, jedoch scharf voneinander abgesetzt sind. Demgegenüber können bei der rhythmischen Fällung von weißem Zinkhydroxid niederschlagsfreie Zwischenzonen von bis zu einigen Zentimetern Höhe beobachtet werden. Ferner wird gezeigt, daß die Bildung Liesegangscher Ringe nicht auf Reaktionen in Gelen beschränkt ist, sondern auch im wäßrigen Medium gelingt, sofern ungestörte Diffusion und die Lokalisierung der schwerlöslichen Umsetzungsprodukte auf andere Weise, wie z.B. in Kapillaren mit sehr geringem Durchmesser, gewährleistet ist. Schließlich wird ein Experiment vorgestellt, bei dem innerhalb weniger Minuten periodische Ammoniumchlorid‐Schichten in einem langen, dünnen Glasrohr entstehen, wenn Ammoniak‐ und Chlorwasserstoff‐Gas von beiden Seiten gegeneinander diffundieren.
β‐Carotin — ein Multitalent
Authors: Tausch Michael W. , Schmidt Andrea 
Published: May 2007

AbstractALLTAGSRELEVANT und lebensnah, begeisternd und verständlich, experimentell und problemorientiert, systematisch und systemisch, fächerübergreifend und allgemeinbildend, die Liste der Forderungen an einen „zeitgemäßen”︁ Chemieunterricht ließe sich noch weiter fortführen. Kaum eine der Forderungen, die derzeit gestellt und diskutiert werden, ist völlig neu. Je nach Gewichtung dieser Forderungen in der Unterrichtspraxis resultieren verschiedene didaktisch‐methodische Ansätze. Die „richtige”︁ Dosis ist umstritten und wird es vermutlich auch bleiben. Doch die Suche danach ist ebenso wie die Erschließung neuer Inhalte für den Unterricht eine permanente Triebkraft fachdidaktischer ForschungIm Aufsatz wird zentriert an der Titelsubstanz β‐Carotin zunächst ein Pool mit Informationen und Experimenten zusammengestellt, aus dem unabhängig vom individuell bevorzugten didaktisch‐methodischen Ansatz geschöpft werden kann. Ausgehend von der Überzeugung, daß Chemie‐verstehen und dadurch auch Chemie‐mögen nur über die Vermittlung ihrer hierarchischen, fachsystematischen Struktur möglich ist, erscheint es heute notwendiger denn je, die lebensnahen Aspekte der Chemie und die Fachsystematik zu integrieren. In diesem Sinne ist β‐Carotin ein Stoff, der bereits im Sachunterricht der Grundschule als Farbstoff in Pflanzen eingeführt und bis zum Abitur immer wieder aufgegriffen werden kann.
Chemiehistorische Experimente: Erze als Ausgangsprodukte für die Herstellung von Arzneimitteln
Authors: Soukup Rudolf Werner 
Published: May 2007

AbstractIN EINER ZEIT, in der insbesondere junge Menschen nach Orientierungspunkten suchen, kommt der Chemiegeschichte eine Wichtige Aufgabe zu. Durch das Kennenlernen ursprünglicher Rohstoffe und im Nachvollzug einfacher alter chemischer Technologien wird ein Bezug zu den materiellen und historischen Voraussetzungen unserer heutigen Existenz hergestellt.
Niedertemperatur‐Zink‐Schwefel‐und Lithium‐Schwefel‐Batterie
Authors: Helms Hartmut , Ristau Jens , Jansen Walter 
Published: May 2007

AbstractSEIT EINIGEN JAHRZEHNTEN sind Hochtemperatur‐Natrium‐Schwefel‐Batterien bereits bekannt und Ziel intensiver Forschung. Hierbei werden flüssiges Natrium und flüssiger Schwefel unter Verwendung geeigneter Festelektrolyte bei Temperaturen von etwa 350°C elektrochemisch umgesetztBei Raumtemperatur und in wäßrigen Elektrolyt‐Lösungen, z.B. Kalilauge, läßt sich der Luftsauerstoff in Zink‐Luft‐Batterien elektrochemisch zur Reaktion bringen. Diese Batterien sind inzwischen technisch ausgereift und z.B. für Hörgeräte im Einsatz. Es stellt sich die Frage, ob nicht auch der gruppenhomologe Schwefel bei Raumtemperatur in wäßrigen Elektrolyt‐Lösungen an geeigneten Elektrodenmaterialien in elektrochemischen Zellen zur Reaktion gebracht werden kannDas ist in der Tat möglich, wenn man Schwefel und Eisen(II)‐sulfid in Ammoniumchlorid‐ oder Natriumchlorid‐Lösungen suspendiert ‐ elektrochemisch reduziert. Die Reduktion verläuft ‐ wahrscheinlich durch Eisen(II)‐sulfid katalysiert ‐ mit großer Schnelligkeit ab, so daß in Zink‐Schwefel‐Batterien Kapazitäten und Energiedichten wie bei Zink‐Braunstein‐Zellen erreicht werden können.
Von der Lumineszenz der Schwefelsäure bis zur Oxidation von Iodid Einfache Versuche im Ultraschallbad
Authors: Lühken Arnim , Bader Hans Joachim 
Published: May 2007

AbstractULTRASCHALL wird nicht ‐ wie meist angenommen ‐ nur für diagnostische Zwecke in der Medizin oder zur Reinigung von Oberflächen eingesetzt. Neben einer ganzen Reihe anderer Anwendungen können bei geeigneten Frequenzen und Intensitäten durch Ultraschall auch chemische Reaktionen ausgelöst oder stark beschleunigt werden. Ebenso lassen sich mit Hilfe von Ultraschall Lösungen entgasen oder Emulsionen herstellen. Besonders bemerkenswert ist die Anregung bestimmter Systeme zur Lumineszenz. Man spricht in diesen Fällen von SonolumineszenzIm vorliegenden Beitrag wird kurz in die Thematik eingeführt und die Wirkung von Ultraschall anhand von Beispielen aufgezeigt, die sich auch sehr einfach im Chemieunterricht nachvollziehen lassen. Experimentell sehr eindrucksvoll sind dabei die Lumineszenz von Schwefelsäure und Natronlauge, die hier erstmalig beschrieben werden.
Self‐oriented perfectionism in eating disorders
Authors: Castro‐Fornieles Josefina , Gual Pilar , Lahortiga Francisca , Gila Araceli , Casulà Vanesa , Fuhrmann Cynthia , Imirizaldu Milagros , Saura Begoña , Martínez Esteve , Toro Josep 
Published: May 2007

AbstractObjective:To assess perfectionism dimensions in eating disorders in comparison with other psychiatric disorders and subjects from the general population.Method:The Child and Adolescent Perfectionism Scale (CAPS), the Eating Disorders Inventory (EDI‐2), and the Eating Attitudes Test (EAT) were administered to a group of 108 female eating‐disordered patients (75 anorexia nervosa and 33 bulimia nervosa), to a group of 86 female psychiatric patients with anxiety (N = 32), depressive (N = 38), or adaptive disorders (N = 16), and to 213 healthy female participants.Results:Both bulimic and anorexic patients scored higher on Self‐Oriented Perfectionism (p < 0.001) than the other two groups but not on Socially‐Prescribed Perfectionism (p = 0.054). Among patients with eating disorder, 17.6% obtained a score two standard deviations higher than the mean in the healthy comparison group on self‐oriented perfectionism; this percentage was significantly higher than in the other two groups. The percentage of eating disorder patients with high socially‐prescribed perfectionism was similar to that found in other psychiatric disorders. Moreover, self‐oriented perfectionism was a predictor of an eating disorder.Conclusion:Self‐oriented perfectionism is more specific to eating disorders than to depressive or anxiety disorders. © 2007 by Wiley Periodicals, Inc.
Illusory correlation as accentuation of actual intercategory difference: Evidence for the effect with minimal stimulus information
Authors: McGarty Craig , Haslam S. Alexander , Turner John C. , Oakes Penelope J. 
Published: May 2007

AbstractDistinctiveness‐based illusory correlation effects (ICEs) have been implicated in the formation of negative stereotypes of minorities. In standard experiments subjects are presented with information about a large and small group in which the ratio of desirable to undesirable members is the same. These conditions normally lead to a negative representation of the smaller group. Explanations of this effect suggest it is a product of (a) over‐representing highly distinctive stimuli, (b) sampling from memory, or (c) regression to the mean following information loss. The present research investigated the possibility that the ICE would occur even where no stimulus information linking behaviours to groups was presented—an outcome inconsistent with the first two explanations. Two experiments (Ns = 83, 112) produced ICEs in the absence of this standard stimulus information in a range of conditions. Results in these and previous studies are shown to be consistent with an explanation in terms of the principle of meta‐contrast derived from self‐categorization theory.
Decoders' processing of emotional facial expression — a top‐down or bottom‐up mechanism?
Authors: Wallbott Harald G. , Ricci‐Bitti Pio 
Published: May 2007

AbstractTo date little evidence is available as to how emotional facial expression is decoded, specifically whether a bottom‐up (data‐driven) or a top‐down (schema‐driven) approach is more appropriate in explaining the decoding of emotions from facial expression. A study is reported (conducted with N = 20 subjects each in Germany and Italy), in which decoders judged emotions from photographs of facial expressions. Stimuli represented a selection of photographs depicting both single muscular movements (action units) in an otherwise neutral face, and combinations of such action units. Results indicate that the meaning of action units changes often with context; only a few single action units transmit specific emotional meaning, which they retain when presented in context. The results are replicated to a large degree across decoder samples in both nations, implying fundamental mechanisms of emotion decoding.
Majority — minority status and perceived ingroup variability revisited
Authors: Bartsch Robert A. , Judd Charles M. 
Published: May 2007

AbstractSocial identity theory predicts that ingroup members should see their group as more homogeneous when confronted by a large and presumably dominant outgroup. This prediction has been supported in a series of recent studies, all of which purport to show that the usual ingroup—outgroup difference in perceived variability, i.e. outgroup homogeneity, is reversed when the ingroup is in a minority position. In all of these studies, however, the ingroup—outgroup distinction has been confounded with the size of the target group judged. The present study was conducted to overcome this confound. Subjects judged both the ingroup and outgroup, under one of two different orders, and the first group judged varied in size across subjects while the size of the second group was held constant. This permitted comparisons of the perceived variability of the second judged group (be it the ingroup or outgroup) when it followed the judgment of either a larger or equal size first group. Consistent with social identity theory, ingroups were judged as less variable when judged after a large outgroup than after a small one. This was true, however, only on measures of perceived dispersion and not on measures of perceived stereotypicality. On both sorts of measures, however, overall outgroup homogeneity was found, over and above the difference due to the comparison of the ingroup with a large or small outgroup.
Acquaintance versus stranger rape: Testing the ambiguity reduction hypothesis
Authors: Kanekar Suresh , Seksaria Veenapani 
Published: May 2007

AbstractAfter reading a vignette about a hypothetical rape incident, 240 undergraduate students of the University of Bombay recommended imprisonment for the rapist and attributed fault to the rape victim. The experiment had a 2 (subject's sex) 2 (schoolteacher versus callgirl victim) × 2 (acquainted versus stranger rapist) × 2 (victim's physical resistance versus no physical resistance) factorial design with 15 subjects per cell. As predicted, attributed victim's fault was greater and recommended rapist's imprisonment was shorter with male rather than female subjects, with the callgirl rather than schoolteacher victim, and with no physical resistance rather than with physical resistance. Greater fault was also attributed to the acquainted rather than unacquainted victim. These main effects and the interaction effects were discussed primarily in light of the proposition that acquaintance rape is viewed less seriously than stranger rape because of ambiguity regarding the acquainted victim's consent.
Class, powerlessness and political polarization
Authors: Evans Geoffrey 
Published: May 2007

AbstractIt is proposed that perceptions of powerlessness influence attitudes towards political policies and ideologies, and that these attitudes influence levels of support for political parties. A cross‐sectional survey analysis of the relations between social class, powerlessness, ideology, and party preference supports this contention. However, the role of powerlessness in influencing the appeal of political attitudes is found to be conditional on respondents' social class. For middle class respondents, powerlessness is associated with opposition to economic redistribution, whereas for the working class it is associated with pro‐redistributive attitudes. For respondents in all classes, powerlessness is associated with authoritarian beliefs, but these are only of relevance for the partisanship of respondents in the middle class. As a consequence of this pattern of relationships, powerlessness is associated with political polarization between social classes, which takes the form of increased support for the Conservative party in the middle class and increased support for the Labour party in the working class. Apart from their substantive implications these findings illustrate the importance of social structural characteristics in conditioning the relationships between social psychological variables.
Anticipated outgroup evaluations and intergroup bias
Authors: Vivian James E. , Berkowitz Norman H. 
Published: May 2007

AbstractA study is reported that tests the hypothesis that group members exhibit intergroup bias in response to the belief that outsiders will discriminate against them. To this end, two experimental conditions are included in which subjects anticipate either biased evaluations or fair evaluations respectively. In a control condition, subjects do not expect to be evaluated from an external source. Results indicated, as expected, that those who anticipated biased evaluations from an outgroup exhibited bias themselves, while those who anticipated fair evaluations exhibited outgroup favouritism. The fact that control subjects exhibited the same degree of bias as those who anticipated biased evaluations from the outgroup poses some difficulties for the hypothesized connection between anticipated discrimination and intergoup bias. Thus, it appears that intergroup bias is the rule and not the exception in an intergroup context. Nevertheless, it is clear that anticipated evaluations of outgroup members can effect intergroup bias.
The impact of salient self‐identities on relative deprivation and action intentions
Authors: Kawakami Kerry , Dion Kenneth L. 
Published: May 2007

AbstractSalient self‐identities and their impact upon feelings of relative deprivation (RD) and subsequent action intentions were examined. Eight experimental conditions (Personal/Group Salience × Large/Small Intragroup Inequalities × Large/Small Intergroup Inequalities) were created utilizing a role‐play design. Significant main effects for both salience and social inequalities were found to influence both RD and action intentions. In accordance with self‐categorization theory, when group compared to personal identities were made salient, stronger feelings of group RD and greater likelihood of collective action intentions were reported. Alternatively, when personal compared to group identities were made salient, greater likelihood of individual actions were reported. In accordance with relative deprivation theory, when intergroup inequalities were large compared to small, stronger feelings of group RD and less likelihood of collective action were reported. Alternatively, when intragroup inequalities were large compared to small, stronger feelings of personal RD were reported.
Locating the central core of social representations: Towards a method
Authors: Guimelli Christian 
Published: May 2007

AbstractA method is presented for locating the central core of social representations which is based on the study of associative relations. The procedure proposed allows estimation of the quantity of the various relations which an inductive item has with induced items produced by subjects during an association task. The procedure shows that when the inductive item is a part of the central core of social representations, the number of relations is significantly greater.
Aiming at the top? Upward social comparison of abilities after failure
Authors: Ybema Jan F. , Buunk Bram P. 
Published: May 2007

AbstractThis study examined the effects of feedback on a task on information seeking and partner preferences as forms of social comparison. It was predicted that subjects who experienced failure and perceived control over future performance would, for reasons of self‐improvement, choose more strongly upward a comparison other than subjects who experienced success or perceived no control. In the experiment, 121 college students were given either failure, average, or success feedback on a bogus test for either a stable or a controllable ability. Next, the subjects choose a comparison other whose test material they would examine, and a comparison other as a partner for writing an evaluation of the test. As predicted, the preferences for information seeking and affiliation were more strongly upward when subjects experienced failure than when subjects experienced success. Perceived control partly resulted in more strongly upward choices in information seeking for subjects experiencing failure.
Beyond mood and social judgment: Mood incongruent recall and mood regulation
Authors: Erber Ralph , Erber Maureen Wang 
Published: May 2007

AbstractTwo studies explored mood incongruent recall and the self‐regulation of moods. In Study I, subjects were put into sad or happy moods before recalling a mood incongruent event. Subjects engaged in one of three types of recall: effortless, effortful, or no recall. Results showed that the greatest change in mood occurred for effortful recall. In Study 2 subjects were again put into a particular mood and were asked to recall anything they wanted — either at the beginning or the end of a class session. In general, subjects chose to remember mood congruent events; however, subjects in negative moods recalled more positive events when they performed the task at the beginning of class. Implications of the results for issues of mood regulation and mood congruent judgment are discussed.
From the child to one's own child: Social dynamics and identities at work
Authors: Emiliani Francesca , Molinari Luisa 
Published: May 2007

AbstractThe present research considers how mothers explain the development of characteristics in different targets, namely their own children, children in general and pupils. This study also examines the role played by mothers' occupation in shaping their expressed views. A questionnaire was completed by 415 mothers in different occupations, housewives, office workers and teachers, and with children between four and eight years of age. The questionnaire presented six types of explanation (from intra‐individual to societal) regarding the development of four characteristics, autonomy, intelligence, order and obedience. Results indicate that when talking about development mothers use different kinds of explanation depending on the target child. Moreover, mothers' professional role is relevant in shaping explanations of children's development.
Reactions to self‐discrepant feedback: Feminist attitude and symbolic self‐completion
Authors: Schiffmann Rudolf , Nelkenbrecher Doris 
Published: May 2007

AbstractReactions to self‐discrepant feedback were theoretically and experimentally investigated. The conceptual frame was provided by the theory of symbolic self‐completion. Starting from the assumption that attitudes can function as central aspects of self‐definition, 81 female subjects were either presented with feedback that their attitudes were unfeminist (treatment, i.e. incompleteness condition) or they received no feedback (control condition) Then they were given the opportunity for self‐symbolizing by subscribing to a feminist journal. Subjects with strongly pro‐feminist attitudes who were made incomplete with respect to their feminist self‐definition subscribed more often and more intensively to the feminist journal than others. The results illustrate that attitudes can take on the character of self‐definitions. Furthermore, reactions to self‐discrepant feedback concerning a central attitude were as predicted by the theory of symbolic self‐completion.
The role of censorship in minority influence
Authors: Clark Russell D 
Published: May 2007

AbstractThis study was conducted to determine the impact of censoring a minority who had argued persuasively against the majority. While there was no significant increase in minority influence when one‐third of the minority's message was censored, the minority was more effective when two‐thirds of its message was censored. The minority was most effective when two‐thirds of its message was censored and when the minority was prevented from continuing to espouse its position. The results were explained by the theory of psychological reactance.
The cues decoders use in attempting to differentiate emotion‐elicited and posed facial expressions
Authors: Hess Ursula , Kleck Robert E. 
Published: May 2007

AbstractDynamic facial expressions, either posed or elicited by afectively evocative materials, were objectively scored to determine the movement cues and temporal parameters associated with the two types of expression. Subjects viewed these expressive episodes and rated each of them on a number of scales intended to assess perceived spontaneousness and deliberateness. Subsequent to viewing all stimuli, subjects reported the specfic cues that they felt they had used to discriminate spontaneous from deliberate expressions. The results reveal that (a) subjects were able to accurately report the cues they employed in the rating task and that (b) these cues were not always valid discriminators of posed and spontaneous expressions. Subjects were in fact relatively poor at identifying expressions of the two types and this low discrimination accuracy was found to be a function of the consistent use of these invalid cues. A measure of the level of perceived honest demeanour of the stimulus persons based on their neutral expressions was found to relate to perceivers accuracy in discriminating posed and spontaneous expressions.