• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 165
  • 27
  • 22
  • Tagged with
  • 212
  • 212
  • 212
  • 212
  • 152
  • 151
  • 124
  • 123
  • 123
  • 123
  • 81
  • 75
  • 30
  • 26
  • 24
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
181

Parental Correlates of Outdoor Play in Boys and Girls Aged 0 to 12: A Systematic Review

Boxberger, Karolina, Reimers, Anne Kerstin 13 February 2019 (has links)
Outdoor play is one major source of physical activity (PA) in children. In particular, parents act as gatekeepers, because they can enable their children’s outdoor play. This systematic review aims to provide an overview of parental correlates of outdoor play. A systematic literature research of six electronic databases (ERIC, PsycARTICLES, PsycINFO, PubMed/Medline, SCOPUS, and Web of Science Core Collection) was conducted with previously defined search terms, focusing on children 0–12 years old. In total, 1719 potentially publications were screened based on eligibility criteria. Included studies were scored for overall study quality. Findings were summarized using a semi-quantitative method. Twenty-one peer-reviewed publications which examined the relationship of parental correlates and outdoor play were included. Overall, five parental correlates were associated with children’s amount of outdoor play: mothers’ ethnicity, mothers’ employment status, parents’ education level, the importance parents assign to outdoor play, and perceived social cohesion in the neighborhood. Merely four studies reported sex/gender-stratified results. In summary, only parents’ encouragement/support provided evidence for girls’ amount of outdoor play. The findings are considered to be of public health relevance for developing intervention programs to increase outdoor play and for improving child’s health. More research, especially considering sex/gender of the child, is required.
182

Humidity Sensing Behavior of Endohedral Li-Doped and Undoped SWCNT/SDBS Composite Films

Müller, Christian, Al-Hamry, Ammar, Kanoun, Olfa, Rahaman, Mahfujur, Zahn, Dietrich R. T., Matsubara, Elaine Yoshiko, Rosolen, José Mauricio 14 February 2019 (has links)
We have investigated single-walled carbon nanotube (SWCNT) networks wrapped with the cationic surfactant sodium dodecyl-benzenesulfonate (SBDS) as promising candidates for water detection. This is the first time that the humidity behavior of endohedral Li-doped (Li@) and undoped SWCNTs/SDBS has been shown. We identified a strong and almost monotonic decrease in resistance as humidity increased from 11 to 97%. Sensitivities varied between −3 and 65% in the entire humidity range. Electrical characterization, Raman spectroscopy, and high-resolution transmission electron microscopy (HRTEM) analysis revealed that a combination of the electron donor behavior of the water molecules with Poole-Frenkel conduction accounted for the resistive humidity response in the Li@SWCNT/SDBS and undoped SWCNT/SDBS networks. We found that Li@SWCNTs boosted the semiconducting character in mixtures of metallic/semiconducting SWCNT beams. Moreover, electrical characterization of the sensor suggested that endohedral Li doping produced SWCNT beams with high concentration of semiconducting tubes. We also investigated how frequency influenced film humidity sensing behavior and how this behavior of SWCNT/SDBS films depended on temperature from 20 to 80 ∘ C. The present results will certainly aid design and optimization of SWCNT films with different dopants for humidity or gas sensing in general.
183

Conference Proceedings of the Advanced Manufacturing Student Conference

Odenwald, Stephan 30 March 2022 (has links)
The Advanced Manufacturing Student Conference (AMSC) represents an educational format designed to foster the acquisition and application of skills related to Research Methods in Engineering Sciences. Participating students are required to write and submit a conference paper and are given the opportunity to present their findings at the conference. The AMSC provides a tremendous opportunity for participants to practice critical skills associated with scientific publication. Conference Proceedings of the conference will benefit readers by providing updates on critical topics and recent progress in the advanced manufacturing engineering and technologies and, at the same time, will aid the transfer of valuable knowledge to the next generation of academics and practitioners.
184

Wissen.Auf den Punkt - Das Jahrbuch der Technischen Universität Chemnitz

18 November 2014 (has links)
Das Jahrbuch der TU Chemnitz erscheint einmal jährlich und gibt einen Rück- und Ausblick auf die Entwicklung der Universität. / The yearbook of TU Chemnitz is published once a year and gives retrospect and perspective of the development of the university.
185

Surface- and tip-enhanced resonant Raman scattering from CdSe nanocrystals

Sheremet, E., Milekhin, A. G., Rodriguez, R. D., Weiss, T., Nesterov, M., Rodyakina, E. E., Gordan, O. D., Sveshnikova, L. L., Duda, T. A., Gridchin, V. A., Dzhagan, V. M., Hietschold, M., Zahn, D. R. T. 27 February 2015 (has links)
Surface- and tip-enhanced resonant Raman scattering (resonant SERS and TERS) by optical phonons in a monolayer of CdSe quantum dots (QDs) is demonstrated. The SERS enhancement was achieved by employing plasmonically active substrates consisting of gold arrays with varying nanocluster diameters prepared by electron-beam lithography. The magnitude of the SERS enhancement depends on the localized surface plasmon resonance (LSPR) energy, which is determined by the structural parameters. The LSPR positions as a function of nanocluster diameter were experimentally determined from spectroscopic micro-ellipsometry, and compared to numerical simulations showing good qualitative agreement. The monolayer of CdSe QDs was deposited by the Langmuir–Blodgett-based technique on the SERS substrates. By tuning the excitation energy close to the band gap of the CdSe QDs and to the LSPR energy, resonant SERS by longitudinal optical (LO) phonons of CdSe QDs was realized. A SERS enhancement factor of 2 × 10<sup>3</sup> was achieved. This allowed the detection of higher order LO modes of CdSe QDs, evidencing the high crystalline quality of QDs. The dependence of LO phonon mode intensity on the size of Au nanoclusters reveals a resonant character, suggesting that the electromagnetic mechanism of the SERS enhancement is dominant. Finally, the resonant TERS spectrum from CdSe QDs was obtained using electrochemically etched gold tips providing an enhancement on the order of 10<sup>4</sup>. This is an important step towards the detection of the phonon spectrum from a single QD. / Dieser Beitrag ist aufgrund einer (DFG-geförderten) Allianz- bzw. Nationallizenz frei zugänglich.
186

Bismuth(III) benzohydroxamates: powerful anti-bacterial activity against Helicobacter pylori and hydrolysis to a unique Bi34 oxido-cluster [Bi34O22(BHA)22(H-BHA)14(DMSO)6]

Pathak, Amita, Blair, Victoria L., Ferrero, Richard L., Mehring, Michael, Andrews, Philip C. 13 March 2015 (has links)
Reaction of BiPh3 or Bi(OtBu)3 with benzohydroxamic acid (H2-BHA) results in formation of novel mono- and di-anionic hydroxamato complexes; [Bi2(BHA)3]∞1, [Bi(H-BHA)3] 2, [Bi(BHA)(H-BHA)] 3, all of which display nM activity against Helicobacter pylori. Subsequent dissolution of [Bi2(BHA)3]∞ in DMSO/toluene results in hydrolysis to the first structurally authenticated {Bi34} oxido-cluster [Bi34O22(BHA)22(H-BHA)14(DMSO)6] 4. / Dieser Beitrag ist aufgrund einer (DFG-geförderten) Allianz- bzw. Nationallizenz frei zugänglich.
187

Magnetic superexchange interactions: trinuclear bis(oxamidato) versus bis(oxamato) type complexes

Abdulmalic, Mohammad A., Aliabadi, Azar, Petr, Andreas, Krupskaya, Yulia, Kataev, Vladislav, Büchner, Bernd, Zaripov, Ruslan, Vavilova, Evgeniya, Voronkova, Violeta, Salikov, Kev, Hahn, Torsten, Kortus, Jens, Meva, Francois Eya'ane, Schaarschmidt, Dieter, Rüffer, Tobias 09 June 2015 (has links)
The diethyl ester of o-phenylenebis(oxamic acid) (opbaH2Et2) was treated with an excess of RNH2 in MeOH to cause the exclusive formation of the respective o-phenylenebis(N(R)-oxamides) (opboH4R2, R = Me 1, Et 2, nPr 3) in good yields. Treatment of 1–3 with half an equivalent of [Cu2(AcO)4(H2O)2] or one equivalent of [Ni(AcO)2(H2O)4] followed by the addition of four equivalents of [nBu4N]OH resulted in the formation of mononuclear bis(oxamidato) type complexes [nBu4N]2[M(opboR2)] (M = Ni, R = Me 4, Et 5, nPr 6; M = Cu, R = Me 7, Et 8, nPr 9). By addition of two equivalents of [Cu(pmdta)(NO3)2] to MeCN solutions of 7–9, novel trinuclear complexes [Cu3(opboR2)(L)2](NO3)2 (L = pmdta, R = Me 10, Et 11, nPr 12) could be obtained. Compounds 4–12 have been characterized by elemental analysis and NMR/IR spectroscopy. Furthermore, the solid state structures of 4–10 and 12 have been determined by single-crystal X-ray diffraction studies. By controlled cocrystallization, diamagnetically diluted 8 and 9 (1%) in the host lattice of 5 and 6 (99%) (8@5 and 9@6), respectively, in the form of single crystals have been made available, allowing single crystal ESR studies to extract all components of the g-factor and the tensors of onsite CuA and transferred NA hyperfine (HF) interaction. From these studies, the spin density distribution of the [Cu(opboEt2)]2− and [Cu(opbonPr2)]2− complex fragments of 8 and 9, respectively, could be determined. Additionally, as a single crystal ENDOR measurement of 8@5 revealed the individual HF tensors of the N donor atoms to be unequal, individual estimates of the spin densities on each N donor atom were made. The magnetic properties of 10–12 were studied by susceptibility measurements versus temperature to give J values varying from −96 cm−1 (10) over −104 cm−1 (11) to −132 cm−1 (12). These three trinuclear CuII-containing bis(oxamidato) type complexes exhibit J values which are comparable to and slightly larger in magnitude than those of related bis(oxamato) type complexes. In a summarizing discussion involving experimentally obtained ESR results (spin density distribution) of 8 and 9, the geometries of the terminal [Cu(pmdta)]2+ fragments of 12 determined by crystallographic studies, together with accompanying quantum chemical calculations, an approach is derived to explain these phenomena and to conclude if the spin density distribution of mononuclear bis(oxamato)/bis(oxamidato) type complexes could be a measure of the J couplings of corresponding trinuclear complexes. / Dieser Beitrag ist aufgrund einer (DFG-geförderten) Allianz- bzw. Nationallizenz frei zugänglich.
188

Ökologische, ökonomische und soziale Nachhaltigkeit an der TU Chemnitz: Posterband mit Beiträgen aus Lehre, Forschung, Administration und von universitären Interessengruppen

Albert, Martin, Hartwig, Melanie, Hüsig, Stefan, Lanfermann, Anna 30 November 2015 (has links)
Alle Akteure der TU Chemnitz wurden 2015 dazu aufgerufen sich an einem Diskurs für Nachhaltigkeit zu beteiligen. Dazu sollten sie folgende Leitfragen beantworten: „Welche Maßnahmen und Projekte setzen Sie, als Akteur (Fakultät, Forschungsverbund, administrative Einheit, universitäre Interessensgruppe), im Rahmen der „ökologischen, ökonomischen und sozialen Nachhaltigkeit“ um? Welche Definition bzw. Konzept oder Leitbild von Nachhaltigkeit legen Sie diesen Maßnahmen und Projekten zugrunde?“ Die eingereichten Beiträge sind in diesem Posterband gesammelt.:Vorwort.........................................................................................1 Forschungsbereich Biopolymere und Naturfaserverbunde (BNF).................3 Professur Energie und Hochspannungstechnik........................................7 Professur für Innovationsforschung und Technologiemanagement.............11 Bundesexzellenzcluster MERGE..........................................................15 Professur Nachrichtentechnik der TU Chemnitz.....................................18 NATUC – Referat für Ökologie und Nachhaltigkeit...................................21 Professur Personal und Führung.........................................................24 Professur Privatrecht und Recht des geistigen Eigentums........................28 SAXEED Gründernetzwerk..................................................................32 Studentenwerk Chemnitz-Zwickau......................................................36 Universitätsbibliothek.......................................................................40 / In 2015 all agents at TU Chemnitz were called to participate in a discours on sustainability. They were asked to answer the following questions: „Which steps and projects regarding „ecological, economic and social sustainability“ do you implement as an actor at the university (faculty, research association, admistrative unit or university interest group)? Which definition, concept or model do you take as a basis for these activities?“ The contributions to this call are collected in this publication.:Vorwort.........................................................................................1 Forschungsbereich Biopolymere und Naturfaserverbunde (BNF).................3 Professur Energie und Hochspannungstechnik........................................7 Professur für Innovationsforschung und Technologiemanagement.............11 Bundesexzellenzcluster MERGE..........................................................15 Professur Nachrichtentechnik der TU Chemnitz.....................................18 NATUC – Referat für Ökologie und Nachhaltigkeit...................................21 Professur Personal und Führung.........................................................24 Professur Privatrecht und Recht des geistigen Eigentums........................28 SAXEED Gründernetzwerk..................................................................32 Studentenwerk Chemnitz-Zwickau......................................................36 Universitätsbibliothek.......................................................................40
189

Chemnitzer Geschichtskalender

Schaarschmidt, Sebastian 06 January 2017 (has links)
Reihe digitaler Kalenderblätter, die historische Beiträge mit Bezug zur Region Chemnitz-Südwestsachsen veröffentlicht. / Series of digital calendar sheets to publish historical contributions related to the region of Chemnitz-South West Saxony.
190

Competition improves robustness against loss of information

Kolankeh, Arash Kermani, Teichmann, Michael, Hamker, Fred H. 21 July 2015 (has links)
A substantial number of works have aimed at modeling the receptive field properties of the primary visual cortex (V1). Their evaluation criterion is usually the similarity of the model response properties to the recorded responses from biological organisms. However, as several algorithms were able to demonstrate some degree of similarity to biological data based on the existing criteria, we focus on the robustness against loss of information in the form of occlusions as an additional constraint for better understanding the algorithmic level of early vision in the brain. We try to investigate the influence of competition mechanisms on the robustness. Therefore, we compared four methods employing different competition mechanisms, namely, independent component analysis, non-negative matrix factorization with sparseness constraint, predictive coding/biased competition, and a Hebbian neural network with lateral inhibitory connections. Each of those methods is known to be capable of developing receptive fields comparable to those of V1 simple-cells. Since measuring the robustness of methods having simple-cell like receptive fields against occlusion is difficult, we measure the robustness using the classification accuracy on the MNIST hand written digit dataset. For this we trained all methods on the training set of the MNIST hand written digits dataset and tested them on a MNIST test set with different levels of occlusions. We observe that methods which employ competitive mechanisms have higher robustness against loss of information. Also the kind of the competition mechanisms plays an important role in robustness. Global feedback inhibition as employed in predictive coding/biased competition has an advantage compared to local lateral inhibition learned by an anti-Hebb rule.

Page generated in 0.0699 seconds