170,191 research outputs found
Mikrowellen-Simulationen am IGVP -- Für Technologie und Fusionsforschung
No full textDie kontrollierte Kernfusion auf der Erde wird mit 100 Millionen Grad Celsius heißen Wasserstoffplasmen erforscht, die durch magnetische Felder eingeschlossen werden. Dabei führt Plasmaturbulenz zu einer Verschlechterung des Einschlusses. Diese Präsentation veranschaulicht Simulationen zur Messung der turbulenten Dichtefluktuationen mittels Dopplerreflektometrie.
Die Präsentation lief anlässlich des Tags der Wissenschaft der Uni Stuttgart am 25.6.2022.
Referenz: Lechte C, Conway G D, Görler T, Tröster C and the ASDEX Upgrade Team 2017 Plasma Phys. Contr. Fusion 59 07500
Effect of Different Working Settings of Sandblasting on Resin Composite Repair Bond Strength
No full textTo investigate the effect of different sandblasting settings on the shear bond strength (SBS) in the repair of resin composite, specimens (resin composite, enamel, and dentin; each group n = 16) were sandblasted by varying the parameters of air pressure (0.2/0.3/0.4 MPa), angle (45/90°), particle size (27/50 μm), tip size (0.8/1.2 mm), and distance (2/5/10 mm) prior to the application of a universal adhesive (Adhese Universal) and resin composite (adhesive area: 7.07 mm2). The specimens were subjected to artificial aging (10,000 cycles, 5–55 °C) prior to (resin composite only) and after repair. Groups without mechanical pretreatment and resin composite incremental bond strength served as controls. Statistical analysis was performed using ANOVAs, post hoc tests, and Chi2-tests (p < 0.05). Only air pressure and distance impacted SBS (p ≤ 0.049). However, resin composite SBS did not differ from the resin composite incremental SBS within all sandblasting settings (positive control: 21.0 ± 5.0 MPa, p ≥ 0.566). While sandblasting did not impact bond strength on enamel (control: 20.5 ± 5.1 MPa, p ≥ 0.999), most settings resulted in a lower bond strength on dentin (control: 20.1 ± 4.7 MPa, p ≤ 0.027). In conclusion, sandblasting significantly improves resin composite repair bond strength, while application parameters are of minor relevance
Going Beyond Counting First Authors in Author Co-citation Analysis
No full textThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Mitomycin C in highly myopic eyes - Author reply
No full textOphthalmology. 2005 Feb;112(2):208-18; discussion 219.
Mitomycin C modulation of corneal wound healing after photorefractive keratectomy in highly myopic eyes.
Gambato C, Ghirlando A, Moretto E, Busato F, Midena E.
SourceRefractive Surgery Service and Antimetabolite Therapy Research Unit, Department of Ophthalmology, University of Padova, Padova, Italy.
Abstract
PURPOSE: To evaluate the role of topical mitomycin C in corneal wound healing (CWH) after photorefractive keratectomy (PRK) in highly myopic eyes.
DESIGN: Prospective, double-masked, randomized clinical trial.
PARTICIPANTS: Seventy-two eyes of 36 patients affected by high (>7 diopters) myopia.
METHODS: In each patient, one eye was randomly assigned to PRK with intraoperative topical 0.02% mitomycin C application, and the fellow eye was treated with a placebo. Postoperatively, mitomycin C-treated eyes received artificial tears (3 times daily, tapered in 3 months), whereas the fellow eye was treated with fluorometholone sodium 2% and artificial tears (3 times daily, tapered in 3 months).
MAIN OUTCOME MEASURES: Uncorrected visual acuity (UCVA) and best-corrected visual acuity (BCVA), contrast sensitivity, manifest refraction, and biomicroscopy. Contrast sensitivity was determined using the Pelli-Robson chart. Corneal confocal microscopy documented CWH.
RESULTS: Mean follow-up was 18 months (range, 12-36). No side effects or toxic effects were documented. At 12-month follow-up examination, UCVAs (logarithm of the minimum angle of resolution) were 0.4+/-0.48 and 0.5+/-0.53 (P = .03) in mitomycin C-treated eyes and corticosteroid-treated eyes, respectively. At 1 year, corneal haze developed in 20% of corticosteroid-treated eyes, versus 0% of mitomycin C-treated eyes. At 12, 24, and 36 months, corneal confocal microscopy showed activated keratocytes and extracellular matrix significantly more evident in untreated eyes (Ps = 0.004, 0.024, and 0.046, respectively).
CONCLUSION: Topical intraoperative application of 0.02% mitomycin C can reduce haze formation in highly myopic eyes undergoing PRK.
Comment in
Ophthalmology. 2006 Feb;113(2):357; author reply 357-8
Towards an Understanding of Hydrogen Supply Chains: A Structured Literature Review Regarding Sustainability Evaluation
No full textHydrogen technologies have received increased attention in research and development to foster the shift towards carbon-neutral energy systems. Depending on the specific production techniques, transportation concepts, and application areas, hydrogen supply chains (HSCs) can be anything from part of the energy transition problem to part of the solution: Even more than battery-driven electric mobility, hydrogen is a polyvalent technology and can be used in very different contexts with specific positive or negative sustainability impacts. Thus, a detailed sustainability evaluation is crucial for decision making in the context of hydrogen technology and its diverse application fields. This article provides a comprehensive, structured literature review in the context of HSCs along the triple bottom line dimensions of environmental, economic, and social sustainability, analyzing a total of 288 research papers. As a result, we identify research gaps mostly regarding social sustainability and the supply chain stages of hydrogen distribution and usage. We suggest further research to concentrate on these gaps, thus strengthening our understanding of comprehensive sustainability evaluations for HSCs, especially in social sustainability evaluation. In addition, we provide an additional approach for discussion by adding literature review results from neighboring fields, highlighting the joint challenges and insights regarding sustainability evaluation
Dispelling the Myths Behind First-author Citation Counts
No full textWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
A Multi-Language Comparison of Influences on Author Verification using Character N-Grams
No full textWe create a new multi-language corpus for author verification based on Wikipedia talkpages, and evaluate the influence that differences in topic and time have on character n-gram author profiles. Topic alignment between two texts is found to increase author verification precision, and an authors writing style is found to change over time, but not more significantly after 3 years than after 1 year.Information ArchitectureWISElectrical Engineering, Mathematics and Computer Scienc
A 0.12mm<sup>2</sup> Wien-Bridge Temperature Sensor with 0.1°C (3σ) Inaccuracy from -40°C to 180°C
No full text Resistor-based temperature sensors can achieve much higher resolution and energy efficiency than conventional BJT-based sensors [1], but they typically occupy more area (> 0.25 mm 2 ) and have lower operating temperatures (le 125 {circ} {C}) [2]-[4]. This work describes a 0.12mm 2 resistor-based sensor that uses a Wien-bridge (WB) filter to achieve 0.1 {circ} {C} (3 sigma) inaccuracy from - 40 {circ} {C} to 180 {circ} {C}. Compared to a state-of-the-art WB sensor [4], it occupies 6 × less area and achieves comparable relative accuracy over a 76% wider operating range. Session 10.3 Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Electronic InstrumentationMicroelectronic
Barthes, Bakhtin, Structuralism: A Reassessment
No full textPhDThe thesis is a comparative analysis of the shared ideas and concerns in the works of
Mikhail Bakhtin and Roland Barthes from the point of view of differences between
French and Slavic literary structuralisms. Its background argument is that the
structuralism developed in the later works of the Russian Formalists and by Prague
Structuralists and Soviet Semioticians is more historically and socially oriented than its
French version, defining the structure of a literary work as a system of all of its
elements and effects (even those that take us outside of the text, like literary tradition
and historical and political circumstances). In this sense, Bakhtin can be seen as a part
of the Slavic structuralist tradition (and not opposed to it as is often claimed), and
Barthes (seen throughout his career) is on the whole perhaps closer to the Slavic
structuralism than he is to the French.
The particular problems discussed are those of the relationship between
literature and ideology, the notions of intertextuality, heteroglossia, dialogism and
polyphony and the differences between them, and the role of the author.
Barthes and Bakhtin shared a lifelong interest in the role of ideology in literature
and the influence of authoritarian language or myth on culture in general and the literary
text in particular. They looked for ways in which the deadening effect of the
mythological (epic, monological) thought and word can be counteracted through
literature, and different versions of what Kristeva termed 'intertextuality' played an
important part in their treatment of the subject. They also both discussed the role of the
author and their voice in the literary text, and the question of their power over the text,
its characters (Bakhtin) and the reader (Barthes).
The main thread of Barthes and Bakhtin's thought focuses on the problem of
counteracting authoritarian language through literature, and the solutions they proposed
can fruitfully be seen in the light of Slavic structuralism's notions of literary structure
A ±25A Versatile Shunt-Based Current Sensor with 10kHz Bandwidth and ±0.25% Gain Error from -40°C to 85°C Using 2-Current Calibration
No full textAccurate current sensing is critical in many industrial applications, such as battery management and motor control. Precise shunt-based current sensors have been reported with gain errors of less than 1% over the industrial temperature range (-40°C to 85°C) [1]–[4]. However, since they are intended for coulomb counting, their bandwidth is limited to a few tens of Hz, making them unsuitable for battery impedance or motor-current sensing. This paper presents a current sensor with a wide (10kHz) bandwidth and a tunable temperature compensation scheme (TCS), which allows it to be flexibly used with different types of shunts while maintaining high accuracy. A low-cost room-temperature calibration scheme is proposed to optimize gain flatness over temperature by exploiting the shunt's self-heating at large currents. Over the industrial temperature range and a ±25A current range, it achieves state-of-the-art gain error (±0.25%) with both low-cost PCB and stable metal-alloy shunts.Green Open Access added to TU Delft Institutional Repository 'You share, we take care!' - Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Electronic InstrumentationMicroelectronic
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