| 1. |
- Zhang, Renyun, et al.
(författare)
-
Soap-film coating : High-speed deposition of multilayer nanofilms
- 2013
-
Ingår i: Scientific Reports. - Nature Publishing Group : Springer Science and Business Media LLC. - 2045-2322. ; 3, s. Art. no. 1477-
-
Tidskriftsartikel (refereegranskat)abstract
- The coating of thin films is applied in numerous fields and many methods are employed for the deposition of these films. Some coating techniques may deposit films at high speed; for example, ordinary printing paper is coated with micrometre-thick layers of clay at a speed of tens of meters per second. However, to coat nanometre thin films at high speed, vacuum techniques are typically required, which increases the complexity of the process. Here, we report a simple wet chemical method for the high-speed coating of films with thicknesses at the nanometre level. This soap-film coating technique is based on forcing a substrate through a soap film that contains nanomaterials. Molecules and nanomaterials can be deposited at a thickness ranging from less than a monolayer to several layers at speeds up to meters per second. We believe that the soap-film coating method is potentially important for industrial-scale nanotechnology.
|
|
| 2. |
- Balliu, Enkeleda, et al.
(författare)
-
Compact nanosecond pulsed single stage Yb-doped fiber amplifier
- 2014
-
Ingår i: Proceedings of SPIE - The International Society for Optical Engineering. - : SPIE. - 9780819498724 ; , s. Art. no. 895910-
-
Konferensbidrag (refereegranskat)abstract
- In this work we present a compact, nanosecond pulsed, single frequency, single stage Yb-doped fiber amplifier by using an overall fiber core diameter of 20 μm. The key component is a custom made, compact, ultra-low noise, single frequency ring-cavity solid state laser (SSL) at 1064 nm used as a master oscillator. The SSL can be designed to provide nanosecond pulses with pulse energies in the sub-mJ range. Our ultimate goal is to develop a compact linearly polarized, single frequency, nanosecond pulsed laser source in an all-fiber format. Short (less than 1m), highly Yb-doped fibers have been used in order to suppress non-linear effects. © 2014 SPIE.
|
|
| 3. |
- Carlsson, Katrin, et al.
(författare)
-
Fear and the Amygdala : Manipulation of Awareness Generates Differential Cerebral Responses to Phobic and Fear-Relevant (but Nonfeared) Stimuli
- 2004
-
Ingår i: Emotion. - : American Psychological Association (APA). - 1528-3542 .- 1931-1516. ; 4:4, s. 340-353
-
Tidskriftsartikel (refereegranskat)abstract
- Rapid response to danger holds an evolutionary advantage. In this positron emission tomography study, phobics were exposed to masked visual stimuli with timings that either allowed awareness or not of either phobic, fear-relevant (e.g., spiders to snake phobics), or neutral images. When the timing did not permit awareness, the amygdala responded to both phobic and fear-relevant stimuli. With time for more elaborate processing, phobic stimuli resulted in an addition of an affective processing network to the amygdala activity, whereas no activity was found in response to fear-relevant stimuli. Also, right prefrontal areas appeared deactivated, comparing aware phobic and fear-relevant conditions. Thus, a shift from top-down control to an affectively driven system optimized for speed was observed in phobic relative to fear-relevant aware processing. (PsycINFO Database Record (c) 2006 APA, all rights reserved) (journal abstract)
|
|
| 4. |
- Danemar, Magnus, et al.
(författare)
-
The associations between health problems and performance in elite cross-country skiers
- 2020
-
Konferensbidrag (refereegranskat)abstract
- Purpose: The aim of this study was to examine the relationships between health problems, defined as injury or illness, on performance during a competitive season among elite XC skiers (9 females; 9 males).Methods: Data was collected for 17 weeks using the Oslo Sports Trauma Research Center questionnaire on health problems, resulting in a total of 296 athlete weeks’ worth of data. Prevalence and severity measures were calculated for all health problems and substantial health problems (defined as problems leading to moderate or severe reductions in training volume or sports performance, or complete inability to participate). Acssociations between health problems and performance were analyzed using regressions with change in FIS points from the 2018/19 season to the 2019/20 season, representing performance.Results: The average weekly prevalence of all health problems was 19% (95% CI: 3.5% to 34%). Prevalence of substantial health problems was 12% (95% CI: -0.4% to 25%). Illness was the most common health problem, representing 74 days (71%) of total time loss compared to overuse injuries (12 days, 12%) and acute injuries (18 days, 17%). There was no significant association between the cumulative severity score of health problems (-0.03; 95% CI: -0.08 to 0.02; p = 0.25).Conclusions: No relationship was identified between the cumulative severity of health problems and performance.Practical applications: The findings from this study suggest that ongoing surveillance programs could be useful in mapping athlete injury and illness trends.
|
|
| 5. |
|
|
| 6. |
- Edvardsson, Sverker, et al.
(författare)
-
Accurate spin axes and solar system dynamics: climatic variations for the Earth and Mars
- 2002
-
Ingår i: Astronomy & Astrophysics. - : EDP Sciences. - 0004-6361 .- 1432-0746. ; 384:2, s. 689-701
-
Tidskriftsartikel (refereegranskat)abstract
- Celestial mechanical simulations from a purely classical point of view of the solar system, including our Moon and the Mars moons {Phobos and Deimos {are carried out for 2 millions of years before present. Within the classical approximation, the results are derived at a very high level of accuracy. Effects from general relativity for a number of variables are investigated and found to be small. For climatic studies of about 1 Myr, general relativity can safely be ignored. Three different and independent integration schemes are used in order to exclude numerical anomalies. The converged results from all methods are found to be in complete agreement. For verification, a number of properties such as spin axis precession, nutation, and orbit inclination for Earth and Mars have been calculated. Times and positions of equinoxes and solstices are continously monitored. As also observed earlier, the obliquity of the Earth is stabilized by the Moon. On the other hand, the obliquity of Mars shows dramatic variations. Climatic influences due to celestial variables for the Earth and Mars are studied. Instead of using mean insolation as in the usual applications of Milankovitch theory, the present approach focuses on the instantaneous solar radiation power (insolation) at each summer solstice. Solar radiation power is compared to the derivative of the icevolume and these quantities are found to be in excellent agreement. Orbital precessions for the inner planets are studied as well. In the case of Mercury, it is investigated in detail.
|
|
| 7. |
- Eliasson, Nina, 1965-
(författare)
-
Att kommunicera skolans naturvetenskap : ett genusperspektiv på elevers deltagande i gemensam och enskild kommunikation
- 2017
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Both individual and whole class communication of students are described in this thesis, which is based on a clear gender perspective. Two articles describe the participation of boys and girls in communication with the whole class, the empirical data collected consisting of videotaped lessons. The extent to which boys and girls participate in the communication is reported in the first study, and in the second the extent to which boys and girls respond to the teacher's closed or open questions about science is presented. The third study reports boys' and girls' individual communication when responding to written science questions. The summary chapter ties the results together from the perspective of Positioning Theory, making the thesis a result of Mixed Methods Research.Results show that boys participate in whole class communication more often than girls, with approximately the same level of dominance as shown in research from the early 80s. Boys also answer more questions than girls, the differences becoming apparent when teachers ask closed questions that can be answered in one or two words. In isolation, girls answer written questions to the same extent as boys, but give longer responses containing a more developed scientific language.Results showing that boys position themselves as knowledgeable more often than girls when teachers ask closed questions, are explained from the perspective of Positioning Theory. Girls more often position themselves as knowledgeable when teachers ask open questions that require reflection. In test situations, with time for reflection, the boys and girls position themselves as knowledgeable students to the same extent.Teachers need to be aware of the positioning attempts created by teaching, and consequently take into account that different approaches in teaching provide boys and girls with different access to the communication space.
|
|
| 8. |
- Eliasson, Nina, 1965-, et al.
(författare)
-
PISA 2012 - Digital problemlösningsförmåga hos 15-åringar i ett internationellt perspektiv
- 2014
-
Rapport (övrigt vetenskapligt/konstnärligt)abstract
- I PISA 2012 genomfördes för första gången ett digitalt prov i problemlösning, i vilket ca 1250 svenska 15-åringar från 209 skolor deltog. Problemlösning kräver bland annat nyfikenhet, uthållighet och kritiskt tänkande. Att kunna lösa problem är också en av de förmågor som på senare tid alltmer har uppmärksammats som betydelsefulla för framgång i utbildning och arbetsliv. Det digitala problemlösningsprovet genomfördes av 28 OECD-länder och 16 icke OECD-länder.
|
|
| 9. |
- Engqvist, Cecilia, et al.
(författare)
-
Interactions between single latex particles and silica surfaces studied with AFM
- 2007
-
Ingår i: Colloids and Surfaces A. - : Elsevier BV. - 0927-7757 .- 1873-4359. ; 302:03-jan, s. 197-203
-
Tidskriftsartikel (refereegranskat)abstract
- The spreading of single styrene-acrylic latex particles on silicon oxide C surfaces was studied using atomic force microscopy (AFM). Three latexes with different glass transition temperature (Tg) were used and the effects of temperature, time and preparation method were investigated. Particle sizes and shape were measured with AFM and the contact angles were calculated. The observed rate for the spreading of latex particles was low and it took several days before the particles reached steady state, even at temperatures well above their T-g. The experimental particle spreading results deviated with two orders of magnitude from predictions Using the WLF equation for polymer diffusion. The deviation could be attributed to polymer-surface interactions that slowed down the particle spreading. The work of adhesion was calculated using two models. The results from using the regular Young-Dupre equation and a modified version of this equation that also included the mechanical properties (E-modulus and Poisson's ratio) of the latexes, were compared. For soft latex particles the results from the two models agreed well and were of the order of 75 J/m(2), but for glassy latexes the Young-Dupre equation underestimated the work of adhesion.
|
|
| 10. |
|
|
