Effects of self-assembly process of latex spheres on the final topology of macroporous silica

This paper surveys the topology of macroporous silica prepared using latex templates covering the submicrometric range (0.1-0.7 mu m). The behavior of latex spheres in aqueous dispersion has been analyzed by dynamic light scattering (DLS) measurement indicating the most appropriate conditions to form well-defined cubic arrays. The optical behavior of latex spheres has been analyzed by transmittance and reflectance measurements in order to determine their diameter and filling factor when they were assembled in bidimensional arrays. Macroscopic templates have been obtained by a centrifugation process and their crystalline ordering has been confirmed by porosimetry and scanning electron microscopy. These self-assembled structures have been used to produce macroporous silica, whose final topology depends on the pore size distribution of the original template. It has been seen that latex spheres are ordered in a predominant fcc arrangement with slipping of tetragonal pores due to the action of attractive electrostatic interactions. The main effect is to change the spherical shape of voids in macroporous silica into a hexagonal configuration with possible applications to fabricate photonic devices with novel optical properties. (c) 2005 Elsevier B.V. All rights reserved.

Nanostructured films from phthalocyanine and carbon nanotubes: Surface morphology and electrical characterization

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Construction of the dispositions of institutional habitus in the academic field

This paper describes the main phases of development of an Institute of Chemistry in relation with national policy from the academic field. Its history begins with a proposal to meet the demand for chemistry teacher education and goes on to become a major center for research, education and extension. Throughout its 50 years of history, the Institution has faced numerous challenges by adopting strategies that have established and revealed its institutional habitus. To this end, we use some of René Kaës’s concepts about the development of groups and institutions, highlighting mainly the origins, expectations and covenants that underpinned its foundation, and the entire process of its expansion and institutionalization. Our main focus, also interpreted based on the theory of Pierre Bourdieu and followers, is the establishment of its institutional habitus, i.e., how it interprets and organizes its institutional teaching, research and extension activities within the context of the academic field. The peculiarity of the process has been the mismatch between internal and external pressures. Even though presenting the results of a case study, in general, our methodology can improve the understanding of institution’s development in relation with educational policy.

Growth evolution of self-textured ZnO films deposited by magnetron sputtering at low temperatures

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Percepção do cirurgião-dentista sobre formação profissional e dificuldades de inserção no mercado de trabalho

Introduction: The evaluation of the perception of graduates is an essential strategy to support the political project educational in universities. Objective: This study aimed to verify the perception of dentists which are working in the labor market, about the difficulties of professional insertion after the graduation, positives and negatives aspects and suggestions regarding the training received. Methodology: This is a qualitative survey conducted with graduates of the years 2000 to 2010, of dentistry course from a Brazilian Public University. A self-administered questionnaire was sent by mail/email to all graduates in the period. The data were transcribed and subjected to content analysis, divided into pre-analysis, characterized by carefully reading floating, material exploration, guidelines for finding the analysis itself. Result: The categories related to the difficulties in early life were: getting a job/workplace, adequate working conditions and low pay, insecurity and confrontation obtained the academic and lack of administrative experience. The perceived positive aspects for the training were: good infrastructure and reputation of the university, integrating teaching-research, teacher-student relationship. The negative aspects comprised the following categories: administrative preparation, lack of integration between content theoretical/ practical, concepts used in the labor market. The suggestions presented are consistent with the difficulties to the beginning of professional life and the negative aspects. Conclusion: The professionals have faced the saturation of the labor market and different reality from those found in academic life. Despite the positive aspects, graduates suggest changes in the course conducted.

How Student Self-Assessment Influences Mastery Of Objectives

In this action research study of my classroom of 7th grade students, enrolled in Pre- Algebra (an 8th grade course), I investigated: rate of homework completion when not taken as part of the academic grade, cognizant self-assessment and its affect on mastery of objectives, and use of self-assessment to guide instruction and re-teaching of classroom objectives. I learned that without sufficient accountability homework completion rates drop with time. Similarly, students can be overconfident in their abilities but unmoved when their summative reports do not match their initial perceived formative benchmarks. Finally, due in part to our society’s reactive nature; students find it more practical to play catch-up rather than staying caught up. As a result of this research, I plan to create, with the help of the students, an accountability statute to help students stay caught up with their understanding of the objectives, as well as allow additional time and energy spent by both student and teacher to react in a timely manner to complete student knowledge within a day or two rather than a week or two later.

Triboelectricity: Macroscopic Charge Patterns Formed by Self-Arraying Ions on Polymer Surfaces

Tribocharged polymers display macroscopically patterned positive and negative domains, verifying the fractal geometry of electrostatic mosaics previously detected by electric probe microscopy. Excess charge on contacting polyethylene (PE) and polytetrafluoroethylene (PTFE) follows the triboelectric series but with one caveat: net charge is the arithmetic sum of patterned positive and negative charges, as opposed to the usual assumption of uniform but opposite signal charging on each surface. Extraction with n-hexane preferentially removes positive charges from PTFE, while 1,1-difluoroethane and ethanol largely remove both positive and negative charges. Using suitable analytical techniques (electron energy-loss spectral imaging, infrared microspectrophotometry and carbonization/colorimetry) and theoretical calculations, the positive species were identified as hydrocarbocations and the negative species were identified as fluorocarbanions. A comprehensive model is presented for PTFE tribocharging with PE: mechanochemical chain homolytic rupture is followed by electron transfer from hydrocarbon free radicals to the more electronegative fluorocarbon radicals. Polymer ions self-assemble according to Flory-Huggins theory, thus forming the experimentally observed macroscopic patterns. These results show that tribocharging can only be understood by considering the complex chemical events triggered by mechanical action, coupled to well-established physicochemical concepts. Patterned polymers can be cut and mounted to make macroscopic electrets and multipoles.

Stabilizing molecular self-assemblies via on-surface reactions

Für die Realisierung zukünftiger Technologien, wie z.B. molekulare Elektronik, werden Strategien benötigt, um funktionale Strukturen direkt auf Oberflächen zu erzeugen. Für die Bewältigung dieser Aufgabe ist die molekulare Selbstanordnung ein äußerst vielversprechender Bottom-up-Ansatz. Hierbei ist eine der größten Herausforderungen das Zusammenspiel aus intramolekularer Wechselwirkung und der Wechselwirkung zwischen Substrat und Molekülen in ein Gleichgewicht zu bringen. Da jedoch die wirkenden Kräfte der molekularen Selbstanordnung ausschließlich reversibler Natur sind, ist eine langfristige Stabilität fragwürdig. Somit ist die kovalente Verknüpfung der gebildeten Strukturen durch Reaktionen direkt auf der Oberfläche unerlässlich, um die Stabilität der Strukturen weiter zu erhöhen. Hierzu stellt die vorliegende Arbeit eine ausführliche Studie zu molekularer Selbstanordnung und der zielgerichteten Modifikation ebensolcher Strukturen dar. Durch den Einsatz von hochauflösender Rasterkraftmikroskopie im Ultrahochvakuum, welche es erlaubt einzelne Moleküle auf Nichtleitern abzubilden, wurde der maßgebliche Einfluss von Ankerfunktionalitäten auf den Prozess der molekularen Selbstanordnung gezeigt. Des Weiteren konnte die Stabilität der selbst angeordneten Strukturen durch neue Oberflächenreaktionskonzepte entschieden verbessert werden. Der Einfluss von Ankerfunktionen, die elektrostatische Wechselwirkung zwischen Molekül und Substrat vermitteln, auf den Strukturbildungsprozess der molekularen Selbstanordnung wird eingehend durch den Vergleich eines aromatischen Moleküls und seines vierfach chlorierten Derivates gezeigt. Für diese beiden Moleküle wurde ein deutlich unterschiedliches Verhalten der Selbstanordnung beobachtet. Es wird gezeigt, dass die Fähigkeit zur Bildung selbst angeordneter, stabiler Inseln entscheidend durch die Substituenten und die Abmessungen des Moleküls beeinflusst wird. Auch wird in dieser Arbeit die erste photochemische Reaktion organischer Moleküle auf einem Isolator gezeigt. Qualitative und quantitative Ergebnisse liefern ein detailliertes Bild darüber, wie die Abmessungen des Substratgitters die Richtung der Reaktion gezielt beeinflussen. Des Weiteren wird ein allgemeines Konzept zur selektiven Stabilisierung selbstangeordneter Molekülstrukturen durch den kontrollierten Transfer von Elektronen präsentiert. Durch die gezielte Steuerung der Menge an Dotierungsatomen wird die Desorptionstemperatur der molekularen Inseln signifikant erhöht und das Desorptionsverhalten der Inseln entschieden verändert. Diese Arbeit präsentiert somit erfolgreich durchgeführte Strategien um den Prozess der molekularen Selbstanordnung zu steuern, sowie entscheidende Mechanismen um die Stabilisierung und Modifizierung von selbst angeordneten Strukturen zu gewährleisten.

We Did It Our Way: Motivations, Satisfactions, and Accomplishments of Senior Academic Women

In a survey of senior academic women whose careers began around 1970, over half of the 98 respondents cited the desire to serve or make a difference and sought personal fulfillment in their work. Most saw men’s motivations as dissimilar, typically as more self-interested and competitive. Despite generally high satisfaction, dissatisfaction with time pressure/workload and with support was common. Satisfactions and accomplishments overlapped. Frequently mentioned were teaching, scholarship, and their discipline, especially by faculty, and programmatic accomplishments, especially by administrators. Many respondents mentioned helping women; many mentioned a collaborative, nurturing style as integral to their success and as different from their typical male colleagues. Context is provided by the metaphor of immigration (Martin, 1997, 2000), the concept of ambivalent sexism (Krefting, 2003; Glick & Fiske, 1999), and recent work on women and leadership by Eagly and colleagues (e.g., Eagly, 2005; Eagly & Carli, 2007).

The Effects of Self-Esteem and Expectancies for Success on Affective Reactions to Achievement

Affective reactions to academic performance appear to be influenced by performance outcome, self-esteem, and causal attributions. We investigated whether expectancies for success and the confirmation or disconfirmation of epectancies also influenced students' affective reactions and causal attributions in achievement settings. Subjects were 132 university students. Causal attributions and affective reactions to an achievement-related situation were assessed and related to students' self-esteem, expectancies for success, and confirmation or disconfirmation of expectancies. Results indicated that causal attributions were related to confirmation or disconfirmation of expectancies for success and to self-esteem. Affective reactions were related to the interaction of self-esteem, expectancies for success, and confirmation or disconfirmation of expectancies. Further analysis suggested that students' affective reactions to performance may serve to maintain existing levels of self-esteem. The role of self-referent and other-referent emotions in self-esteem maintenance was also discussed.

The role of self-esteem in affective reactions to achievement-related situations

Investigated whether affective reactions in achievement settings were related to self-esteem in 308 undergraduates. Ss completed a self-esteem questionnaire and an affect questionnaire in which achievement outcomes and causal sources were manipulated within a short-story format. Affective reactions to various academic situations portrayed in the stories then were assessed and related to Ss' self-esteem. Resulting biserial correlations between the dichotomized affective reactions and self-esteem indicate that affective reactions to success and failure were related to Ss' level of self-esteem. An extrapolation from the present results and related research is that causal internalization with resulting self-referent affects may be facilitated by providing academic feedback consistent with self-esteem.

Effect of Classroom Gender Composition on Students' Development of Self-Regulated Learning Competencies

Success in any field depends on a complex interplay among environmental and personal factors. A key set of personal factors for success in academic settings are those associated with self-regulated learners (SRL). Self-regulated learners choose their own goals, select and organize their learning strategies, and self-monitor their effectiveness. Behaviors and attitudes consistent with self-regulated learning also contribute to self-confidence, which may be important for members of underrepresented groups such as women in engineering. This exploratory study, drawing on the concept of "critical mass", examines the relationship between the personal factors that identify a self-regulated learner and the environmental factors related to gender composition of engineering classrooms. Results indicate that a relatively student gender-balanced classroom and gender match between students and their instructors provide for the development of many adaptive SRL behaviors and attitudes.

Legality and Human Rights: Administrative Justice in Russia 1862-1917

The question of how far pre-revolutionary Russia was from the ideal of a lawful state has received little academic attention, particularly as relates to the legal regulation of relations between person, society and state within the state administration. Pravilova explored the methods of settling disputes between individuals and the administration, and the emergence of legal controls of the administration, analysed projects for the organisation of administrative justice and studied the particular nature of concepts from Russian administrative justice. The idea of an organisation of special bodies examining complaints by private persons against the actions of officials and state bureaucratic organs first appeared in the early 1860s. In the 1870s-1890s various projects for the reform of administrative justice (reorganisation of the Senate and local administrative institutions) were proposed by the Ministries of Justice and Finance, but none of these was put into practice, largely due to resistance from the bureaucracy. At the same time, however, the rapid development of private enterprise, the activities of the zemstvo and self-government produced new norms and mechanisms for the regulation of authorities and social relations. Despite the lack of institutional conditions, the Senate did consider complaints from private persons against illegal actions by administrative officials, playing a role similar to that of the supreme administrative courts in France and Germany. The spread of concepts of a 'lawful state' aroused support for a system of administrative justice and the establishment of administrative tribunals was seen as a condition of legality and a guarantee of human rights. The government was forced to understand that measures to maintain legality were vital to preserve the stability of the system of state power, but plans for liberal reforms were pushed into the background by constitutional reforms. The idea of guarantees of human rights in relations with the authorities was in contradiction with the idea of the monarchy and it was only when the Provisional Government took power in 1917 that the liberal programme of legal reforms had any chance of being put into practice. A law passed in June 1917 ordained the organisation of local administrative justice bodies, but its implementation was hampered by the war, the shortage of qualified judges and the existing absolute legal illiteracy, and the few administrative courts that were set up were soon abolished by the new Soviet authorities. Pravilova concluded that the establishment of a lawful state in pre-revolutionary Russia was prevented by a number of factors, particularly the autocratic nature of the supreme authority, which was incompatible with the idea of administrative justice as a guarantee of the rights of citizens in their relations with the state.

A chrysophyte stomatocyst-based reconstruction of cold-season air temperature from Alpine Lake Silvaplana (AD 1500–2003); methods and concepts for quantitative inferences

Relatively little is known about past cold-season temperature variability in high-Alpine regions because of a lack of natural cold-season temperature proxies as well as under-representation of high-altitude sites in meteorological, early-instrumental and documentary data sources. Recent studies have shown that chrysophyte stomatocysts, or simply cysts (sub-fossil algal remains of Chrysophyceae and Synurophyceae), are among the very few natural proxies that can be used to reconstruct cold-season temperatures. This study presents a quantitative, high-resolution (5-year), cold-season (Oct–May) temperature reconstruction based on sub-fossil chrysophyte stomatocysts in the annually laminated (varved) sediments of high-Alpine Lake Silvaplana, SE Switzerland (1,789 m a.s.l.), since AD 1500. We first explore the method used to translate an ecologically meaningful variable based on a biological proxy into a simple climate variable. A transfer function was applied to reconstruct the ‘date of spring mixing’ from cyst assemblages. Next, statistical regression models were tested to convert the reconstructed ‘dates of spring mixing’ into cold-season surface air temperatures with associated errors. The strengths and weaknesses of this approach are thoroughly tested. One much-debated, basic assumption for reconstructions (‘stationarity’), which states that only the environmental variable of interest has influenced cyst assemblages and the influence of confounding variables is negligible over time, is addressed in detail. Our inferences show that past cold-season air-temperature fluctuations were substantial and larger than those of other temperature reconstructions for Europe and the Alpine region. Interestingly, in this study, recent cold-season temperatures only just exceed those of previous, multi-decadal warm phases since AD 1500. These findings highlight the importance of local studies to assess natural climate variability at high altitudes.

Is low self-esteem a risk factor for depression? Findings from a longitudinal study of Mexican-origin youth

We examined the relation between low self-esteem and depression using longitudinal data from a sample of 674 Mexican-origin early adolescents who were assessed at age 10 and 12 years. Results supported the vulnerability model, which states that low self-esteem is a prospective risk factor for depression. Moreover, results suggested that the vulnerability effect of low self-esteem is driven, for the most part, by general evaluations of worth (i.e., global self-esteem), rather than by domain-specific evaluations of academic competence, physical appearance, and competence in peer relationships. The only domain-specific self-evaluation that showed a prospective effect on depression was honesty-trustworthiness. The vulnerability effect of low self-esteem held for male and female adolescents, for adolescents born in the United States versus Mexico, and across different levels of pubertal status. Finally, the vulnerability effect held when we controlled for several theoretically relevant 3rd variables (i.e., social support, maternal depression, stressful events, and relational victimization) and for interactive effects between self-esteem and the 3rd variables. The present study contributes to an emerging understanding of the link between self-esteem and depression and provides much needed data on the antecedents of depression in ethnic minority populations