| 1. |
- Bergqvist, Björn, 1965, et al.
(author)
-
Effect of microwave radiation on permeability of liposomes. Evidence against non-thermal leakage
- 1994
-
In: Biochimica et Biophysica Acta - General Subjects. - : Elsevier BV. - 1872-8006 .- 0304-4165. ; 1201:1, s. 51-54
-
Journal article (peer-reviewed)abstract
- The effect of 2.45 GHz microwave radiation on the permeability of unilamellar phosphatidylcholine liposomes has been studied. Leakage of 5(6)-calboxyfluorescein from the liposomes was measured using spectrofluorimetry after exposure to either microwaves or thermal heating for 5-20 min intervals. The exposure temperature, 37.6 +/- 0.5 degrees C, was well above the phase transition temperature of the lipid membrane. The microwave exposure did not result in any non-thermal increase in permeability above that produced by thermal heating. This study refutes the results reported by Saalman et al. [1] in which an increased liposome permeability due to microwave exposure was reported. The refined analysis in the present study shows that this increased liposome permeability was not a non-thermal microwave effect.
|
|
| 2. |
|
|
| 3. |
- Engström, David, 1976, et al.
(author)
-
Analog low-loss full-range phase modulation by utilizing a V-shaped switched ferroelectric liquid-crystal cell in reflective mode
- 2006
-
In: Optics Letters. - 0146-9592 .- 1539-4794. ; 31:19, s. 2906-2908
-
Journal article (peer-reviewed)abstract
- We have studied the analog (V-shaped switching) mode in ferroelectric liquid crystals in reflective mode for analog phase modulation applications. We have found that several combinations of cell thicknesses and input polarization states exist for which near-lossless analog phase modulation with a range of ~2π rad is obtained, and we demonstrate one such combination experimentally. Despite a slight deviation from the ideal conditions, e.g., the tilt angle was 38° instead of the desired 45°, virtually pure 1.6π rad phase modulation was obtained; the measured values agree very well with our numerical simulations of the real device.
|
|
| 4. |
- Engström, David, 1976, et al.
(author)
-
Diffraction-based determination of the phase modulation for general spatial light modulators
- 2006
-
In: Applied Optics. - 1539-4522. ; 45:28, s. 7195-7204
-
Journal article (peer-reviewed)abstract
- We describe a characterization method based on diffraction for obtaining the phase response of spatial light modulators (SLMs), which in general exhibit both amplitude and phase modulation. Compared with the conventional interferometer-based approach, the method is characterized by a simple setup that enables in situ measurements, allows for substantial mechanical vibration, and permits the use of a light source with a fairly low temporal coherence. The phase determination is possible even for a SLM with a full amplitude modulation depth, i.e., even if there are nulls in the amplitude transmission characteristic of the SLM. The method successfully determines phase modulation values in the full 2pi rad range with high accuracy. The experimental work includes comparisons with interferometer measurements as well as a SLM characterization with a light-emitting diode (LED).
|
|
| 5. |
|
|
| 6. |
- Engström, David, 1976, et al.
(author)
-
Three-level phase modulator based on orthoconic antiferroelectric liquid crystals
- 2006
-
In: Optics Letters. - 0146-9592 .- 1539-4794. ; 31:21, s. 3158-3160
-
Journal article (peer-reviewed)abstract
- Surface-stabilized orthoconic antiferroelectric liquid crystals (OAFLCs) have a director tilt of θ=45° and are, with no field applied, negatively uniaxial with the optic axis perpendicular to the cell substrates. We demonstrate that OAFLCs can be utilized to achieve lossless phase modulation with three almost equidistant phase levels. This turns out to be true also for polymer-stabilized OAFLCs, where the polymer network increases the switching speed of the device without affecting the phase modulation appreciably.
|
|
| 7. |
- Galt, Sheila, 1956
(author)
-
A coarse look at course evaluations - coupling to course quality and gender bias
- 2020
-
Conference paper (other academic/artistic)abstract
- What do student course evaluations really tell us about course (and teacher) quality? Let’s look at possible problems (example: gender bias) and other evaluation methods (example: teaching practices inventory). Data on “overall impression”, suggests that Chalmers students favour courses given by male examiners when it comes to “top notch” ratings.
|
|
| 8. |
- Galt, Sheila, 1956
(author)
-
Att stödja lärarutveckling i praktiken – med utblick från praktiken på Lärande och Ledarskap
- 2016
-
Conference paper (other academic/artistic)abstract
- Kort sammanfattning:Hur kan man göra rent praktiskt för att stödja lärares utveckling? Vi tar en titt under ytan på våra första två praktikkurser på masterprogrammet MPLOL. Skulle studenters lärande över hela Chalmers gagnas av att deras lärare (bland mycket annat) fått stöd med liknande metoder?Kort abstract: Lärandemålen, aktiviteterna och examinationsmetoderna beskrivs kortfattat för de två 7,5 hp kurserna där mastersstudenter på Lärande och Ledarskap (MPLOL) tränar upp sina praktiska färdigheter som gymnasielärare. Dessa verksamhetsförlagd utbildning (VFU) kurser är förlagda till speciellt utvalda övningsskolor i trakten, där studenterna vägleds av gymnasielärare som erbjuds en handledarutbildning på 7,5 hp på Chalmers. Dessutom får studenterna stöd av två mästarlärare, yrkesverksamma gymnasielärare som anställs på deltid under två år på Chalmers. Institutionen MC2 ger dessa tre kurser, där jag själv agerar examinator och kursansvarig lärare.Under presentationen kommer jag att lyfta fram några delar av innehållet och metodiken i dessa två VFU kurser som skulle kunna inspirera till vidareutveckling av Chalmers egna lärarkår. Några aspekter liknar det som idag redan ingår i paketet med 15 hp som utgör ”Diploma of Higher Education”, den formella pedagogiska utbildningen som erbjuds Chalmers lärare. Ytterligare några aspekter liknar arbetsmetoder som Chalmers pedagogiska utvecklare (peduler) använder vid stöd till enskilda lärare. Viceprefekter för grundutbildning och programansvariga kan finna metoder här som kan anpassas till utvecklingsaktiviteter för ”sina” lärargrupper.Det är min förhoppning att inspiration även kan hämtas ur presentationen för att stödja ”självhjälp” och kollegialt utbyte till gagn för Chalmerslärares egen utveckling. Återkommande strukturerad observation i den verkliga undervisningssituationen (auskultation) är ett starkt drivande verktyg som används flitigt på VFU-kurserna. Detta är relativt enkelt att implementera kollegor emellan.Lärandeaktiviteterna på VFU-kurserna inkluderar, förutom övningsundervisning och auskultation, även en rad andra aktiviteter. Vid minst ett tillfälle under varje kurs får studenterna spela in sina lektioner och utvärdera filmerna tillsammans med sina handledare i relation till utvalda lärandemål. Studenterna skriver en strukturerad loggbok till stöd för kommunikationen med mästarlärarna. Situationer som sällan uppstår men ändå behöver förberedas inför yrkeslivet som lärare får tränas med ”torrsim” via seminarier och inlämningsuppgifter. Exempel på dessa är etiska dilemman, konflikthantering och specialpedagogik.En återkommande problematik för både gymnasielärare och Chalmerslärare är det breda spektrum av förkunskaper och fallenhet man möter i en klass. Att kunna stödja de svagaste och utmana de starkaste är ett explicit lärandemål som studenterna jobbar med.Ledarskap i klassrummet betonas och studenterna får träna metoder att aktivera eleverna under ”genomgångar”, metoder som med fördel kan användas för att aktivera Chalmersstudenter under föreläsningar.VFU-kurserna heter Lärande och Ledarskap i praktiken 1 och 2 (CIU207 och CIU212). I den första kursen fokuserar studenterna på matematikundervisning och i den andra på antingen fysik- kemi- eller teknikundervisning, beroende på vilket program de går på Chalmers.Examinationen i kurserna ger graderade slutbetyg (underkänt, 3, 4 eller 5) där mycket av input till betyget kommer ifrån handledarens utvärdering samt två olika lektionsbesök av mästarlärare och examinator. Kvalitet på skriftliga inlämningsuppgifter samt kommunikations- och reflektionsförmåga i loggboken ligger också till grund för betyget. Totalt under dessa två kurser har studenterna ett obligatorium på 50 timmars egen övningsundervisning och 30 timmars auskultation.Vi har idag en klass på 19 studenter som går först året tillsammans (14 MPLOL och 5 KPLOL, kompletterande pedagogisk utbildning). MPLOL startade 2011, och studenterna blir både gymnasielärare och civilingenjörer. Ungefär en tredjedel av de som gått ut programmet arbetar nu som gymnasielärare.
|
|
| 9. |
- Galt, Sheila, 1956, et al.
(author)
-
Demonstration of distortion suppression in photonic time-stretch ADC using back propagation method
- 2007
-
In: MWP 2007 - 2007 IEEE International Topical Meeting on Microwave Photonics. - 1424411688 ; , s. Pages 141-144
-
Conference paper (peer-reviewed)abstract
- We experimentally demonstrate the performance of the recently proposed "OBP" algorithm based on optical phase retrieval by numerical back-propagation. Using this technique, distortion due to the modulator transfer function as well as the group velocity dispersion in a photonic time-stretch ADC (TS-ADC) can be suppressed, and frequency fading eliminated thanks to the use of a dual output "phase diverse" modulator. The algorithm was tested with a swept input signal frequency from 10 to 50 GHz as well as with a two-tone signal, and is shown to recover the signal even in the presence of fading with a distortion suppression of up to 26 dB. These results also constitute the first experimental demonstration of channel combining in a phase diverse TS-ADC. © 2007 IEEE.
|
|
| 10. |
- Galt, Sheila, 1956
(author)
-
Do Urban Myths About Learning and Education Influence Students and Teachers at Chalmers?
- 2019
-
Conference paper (other academic/artistic)abstract
- SHORT SUMMARY There are a number of persistent myths about learning and education that could be important to be aware of as a student or teacher at Chalmers. For example, “learning styles” reflect preferences but not what really works best for learners. We will explore a few myths together in this workshop. ABSTRACT Introduction to the workshop topic The title of this presentation is a question, to which we ought to be able to answer an emphatic “no – of course not!” However, a more reasonable answer might be “probably now and then, but let’s systematically reduce the probability!” The purpose of this workshop is to relate and explore a few myths about learning and education taking our starting point from a recent book by de Bruyckere, Kirschner and Hulshof (2015). I have made a selection of three groups of myths I deem relevant for students and teachers at Chalmers to be aware of, and have designed a set of workshop activities to highlight and discuss. For each group of myths, the original (false) statements and the debunking of the myths will be followed by a structured group discussion. After the completion of the workshop, participants will hopefully have a nuanced view of the relevance of these myths for teaching and learning at Chalmers, and an understanding of suggested replacements for these myths using recommendations from evidence-based research. Relevance for quality of education Students and teachers have a tacit understanding that the most effective learning and teaching methods will be used in designing a high quality education at Chalmers. Allowing myths rather than evidence-based recommendations to guide choices is not going to provide the best possible educational quality, even though those involved are earnest in their belief in such myths. Workshop activities For each of the myth groups in the table below, the participants will explore the material in plenum and then small groups according to the following steps: 1. Plenum introduction to the pair of myths in the myth group at hand. 2. Small group discussion of examples where this might be relevant to teaching and learning at Chalmers. 3. Group discussion of what needs to be investigated in order to make an informed choice as to teaching and learning methods that work. 4. Plenum discussion of points 2 and 3 above, followed by a short overview of relevant evidence–based research results. Points 1-4 will be repeated for each of the three myth groups. In a concluding small group discussion, participants will be invited to articulate their own standpoints and how they intend to apply the insights they may have gained in the workshop. Documentation of a summary of discussions and personal standpoints will be collected electronically and anonymously after permission from the participants. Selected groups of myths for this workshop The following list covers the most important myths which participants will explore during the workshop. Each myth is described and debunked in the book by Bruyckere, Kirschner and Hulshof (2015). The phrasing of the myths as a postulation is used as subchapter headings in this book, and tabulated below for reference, along with the relevant page number in the book. I have also included a keyword phrase for each, and a short note on the debunking of the myth. Table headings (Note that table formatting is not available here.) Myth keywords Postulation of myth Page Debunking of myth Myth group 1: Myths about learning styles and quantitative learning pyramids Learning styles People have different styles of learning. 20 People may prefer different ways of learning, but this does not correlate with what works best. No evidence supports the grouping of people in learning styles. Learning pyramid The effectiveness of learning can be shown in a pyramid. 28 The even percentages attributed to activities such as 30% retention from demonstration is a tell-tale sign of a myth. Origin not based on sound evidence. Myth group 2: Myths about discovery and problem-based learning Discovery learning You learn better if you discover things for yourself rather than having them explained to you by others. 48 This is often ineffective, especially for the novice without prior knowledge of the subject matter. Low ability students enjoy it but learn very little. With the right guidance and support the method works better. Problem-based learning You can learn effectively through problem-based education. 54 This is not effective for learning new content, but rather for applying previous knowledge. Myth group 3: Myths about ICT in education and reading of course literature Digital natives Today’s digital natives are a new generation who want a new style of education. 139 Neither educational content nor learning methods need be changed for the generation who grew up with the internet. Reading habits Young people don’t read any more. 149 This is not true, although reading for pleasure is declining. REFERENCE de Bruyckere, P., Kirschner, P. and Hulshof, C. (2015). Urban myths about learning and education. London: Academic Press.
|
|
