| 1. |
|
|
| 2. |
- Hitzler, P., et al.
(författare)
-
Preface
- 2019
-
Ingår i: Lecture Notes in Computer Science. - : Springer. - 9783030213473 ; , s. v-vii
-
Bokkapitel (populärvet., debatt m.m.)
|
|
| 3. |
- Streubel, K., et al.
(författare)
-
Long wavelength vertical cavity lasers
- 1999
-
Ingår i: Proceedings of SPIE - The International Society for Optical Engineering. - San Jose, CA, USA. ; 3625:Bellingham, WA, United States, s. 304-314
-
Tidskriftsartikel (refereegranskat)abstract
- We report on three novel vertical cavity laser (VCL) structures for 1.55 Όm operation. Two of the VCL structures utilize an n-type GaInAsP/InP Bragg mirror combined with an Al(Ga)As/GaAs mirror using either wafer-fusion or metamorphic epitaxial growth. The third VCL employs two wafer fused AlGaAs/GaAs mirrors, in which lateral current confinement is obtained by localized fusion of the p-mirror. All three VCLs use strained GaInAsP quantum wells as active material and achieve continuous-wave (CW) operation at room-temperature or above. The single fused VCL operates up to 17 °C and 101 °C in continuous-wave and pulsed mode, respectively. The monolithic VCL-structure with a metamorphic GaAs/AlAs n-type mirror uses a reversed biased tunnel junction for current injection. This laser achieves record high output power (1mW) at room temperature and operates CW up to 45 °C. The double fused VCLs with a 10×10 Όm2 active area operate CW up to 30 °C with threshold current as low as 2.5 mA and series resistance of 30 Ohms. The emission spectra exhibit a single lasing mode polarized with 30 dB extinction ratio and a spectral linewidth of 150 MHz.
|
|
| 4. |
- Hammar, Arvid, 1986, et al.
(författare)
-
Optical designs for a multi-beam 340 and 625/640 GHz Spaceborne climate research instrument
- 2015
-
Ingår i: 26th International Symposium on Space Terahertz Technology, ISSTT 2015.
-
Konferensbidrag (refereegranskat)abstract
- We report on an ongoing study where different optical configurations for a multi-beam limb-viewing (four to eight receiver channels at 340 and two channels at 625 GHz) space-borne instrument for climate research are presented and compared. The optical configurations are analyzed in terms of optical performance (gain, side lobe levels, beam efficiency etc.), weight and size of the overall instrument envelope. Using ideal fundamental Gaussian beam modes and numerical tools relying on ray-tracing and physical optics methods, the different configurations are designed and evaluated. Preliminary results indicate that a 1.3 m × 0.65 m primary reflector can be used in a configuration that includes a relay optics system having two to four elements. In addition to the limb-viewing instrument, there will be an additional instrument operating at 640 GHz for observing clouds in nadir mode.
|
|
| 5. |
- Siedler, S., et al.
(författare)
-
High throughput droplet sorting of yeast for p-Coumaric acid production detected by co-encapsulated E. coli biosensor bacteria
- 2016
-
Ingår i: 20th International Conference on Miniaturized Systems for Chemistry and Life Sciences, MicroTAS 2016. - : Chemical and Biological Microsystems Society. - 9780979806490 ; , s. 551-552
-
Konferensbidrag (refereegranskat)abstract
- We present the optimization of E. coli biosensor bacteria and demonstrate their use to detect and sort co-encapsulated S. cerevisiae yeast cells by their p-Coumaric acid (pCA) production in picoliter microfluidic droplets at high throughput. This strategy allows us to enrich pCA producing cell factories by the cell permeable product pCA using a biosensor in a separate cell.
|
|
| 6. |
- Siedler, S., et al.
(författare)
-
Development of a Bacterial Biosensor for Rapid Screening of Yeast p-Coumaric Acid Production
- 2017
-
Ingår i: ACS Synthetic Biology. - : American Chemical Society (ACS). - 2161-5063. ; 6:10, s. 1860-1869
-
Tidskriftsartikel (refereegranskat)abstract
- Transcription factor-based biosensors are used to identify producer strains, a critical bottleneck in cell factory engineering. Here, we address two challenges with this methodology: transplantation of heterologous transcriptional regulators into new hosts to generate functional biosensors and biosensing of the extracellular product concentration that accurately reflects the effective cell factory production capacity. We describe the effects of different translation initiation rates on the dynamic range of a p-coumaric acid biosensor based on the Bacillus subtilis transcriptional repressor PadR by varying its ribosomal binding site. Furthermore, we demonstrate the functionality of this p-coumaric acid biosensor in Escherichia coli and Corynebacterium glutamicum. Finally, we encapsulate yeast p-coumaric acid-producing cells with E. coli-biosensing cells in picoliter droplets and, in a microfluidic device, rapidly sort droplets containing yeast cells producing high amounts of extracellular p-coumaric acid using the fluorescent E. coli biosensor signal. As additional biosensors become available, such approaches will find broad applications for screening of an extracellular product.
|
|
| 7. |
- Stevens, R., et al.
(författare)
-
Microstructured photonic crystal for single-mode long wavelength VCSELs
- 2008
-
Ingår i: Semiconductor Lasers and Laser Dynamics III. - : SPIE.
-
Konferensbidrag (refereegranskat)abstract
- In this article, we report on long wavelength (1.27 ÎŒm) single-mode micro-structured photonic crystal strained InGaAs quantum wells VCSELs for optical interconnection applications. Single fundamental mode room-temperature continuous-wave lasing operation was demonstrated for devices designed and processed with different two-dimensional etched patterns. The conventional epitaxial structure was grown by Metal-Organic Vapor Phase Epitaxy (MOVPE) and contains fully doped GaAs/AlGaAs DBRs, one oxidation layer and three strained InGaAs quantum wells. The holes were etched half-way through the top-mirror following various designs (triangular and square lattices) and with varying hole's diameters and pitches. We obtained up to 1.7 mW optical output power and more than 30 dB Side-Mode Suppression Ratio (SMSR) at room temperature and in continuous wave operation. Systematic static electrical, optical and spectral characterization was performed on wafer using an automated probe station. Numerical modeling using the MIT Photonic-Bands (MPB [1]) package of the transverse modal behaviors in the photonic crystal was performed using the plane wave method in order to understand the index-guiding effects of the chosen patterns, and to further optimize the design structures for mode selection at the given wavelength.
|
|
| 8. |
- Perry, Diana, et al.
(författare)
-
Temperate fish community variation over seasons in relation to large-scale geographic seascape variables
- 2018
-
Ingår i: Canadian Journal of Fisheries and Aquatic Sciences. - : Canadian Science Publishing. - 0706-652X .- 1205-7533. ; 75:10, s. 1723-1732
-
Tidskriftsartikel (refereegranskat)abstract
- In shallow-water marine environments, ecosystem functioning is a complex interworking of fine-scale characteristics and region-wide factors, and the importance of these variables can vary on multiple temporal and spatial scales. This underwater video study targeted seasonal changes in the fish community of seagrass habitats along the Swedish west coast and the influence of offshore seascape variables (latitudinal position, wave exposure, open ocean, and deep water). Results showed that fish assemblage structure exhibited seasonal changes between summer and autumn and strong spatiotemporal variations in the importance of offshore factors affecting shallow-water fish communities. In summer, abundance from the Gobiidae family responded to wave exposure, whereas the Gadidae family and juvenile migrant habitat preference guild responded to latitudinal position and proximity to deep water. In autumn, deep water was related to abundance of Gadidae and juvenile migrants, whereas latitudinal position influenced Gasterosteidae. These findings underscore the importance of understanding the influence of offshore factors on facets of coastal fish assemblages to address large-scale geographic connectivity along nearshore–offshore gradients.
|
|
| 9. |
- Zabel, Thomas, et al.
(författare)
-
Auger recombination in In(Ga)Sb/InAs quantum dots
- 2015
-
Ingår i: Applied Physics Letters. - : American Institute of Physics (AIP). - 0003-6951 .- 1077-3118. ; 106:1
-
Tidskriftsartikel (refereegranskat)abstract
- We report on the epitaxial formation of type II In0.5Ga0.5Sb/InAs and InSb/InAs quantum dot ensembles using metal organic vapor phase epitaxy. Employing scanning tunneling spectroscopy, we determine spatial quantum dot dimensions smaller than the de Broglie wavelength of InGaSb, which strongly indicates a three dimensional hole confinement. Photoluminescence spectroscopy at low temperatures yields an enhanced radiative recombination in the mid-infrared regime at energies of 170-200 meV. This luminescence displays a strong excitation power dependence with a blueshift indicating a filling of excited quantum dot hole states. Furthermore, a rate equation model is used to extract the Auger recombination coefficient from the power dependent intensity at 77 K yielding values of 1.35 x 10(-28) cm(6)/s for In0.5Ga0.5Sb/InAs quantum dots and 1.47 x 10(-27) cm(6)/s for InSb/InAs quantum dots, which is about one order of magnitude lower as previously obtained values for InGaSb superlattices.
|
|
| 10. |
- Eklöf, Johan, 1978, et al.
(författare)
-
The importance of grazing intensity and frequency for physiological responses of the tropical seagrass Thalassia hemprichii
- 2008
-
Ingår i: Aquatic Botany. - : Elsevier BV. - 0304-3770. ; 89, s. 337-340
-
Tidskriftsartikel (refereegranskat)abstract
- Seagrass grazing is an intrinsic disturbance in primarily tropical and subtropical areas. While there is a general parabolic response in seagrass growth to grazing intensity, there is less knowledge on the role of grazing frequency, as well as potential interactions between grazing intensity and frequency. This study experimentally investigated physiological responses in Thalassia hemprichii to simulated (leaf cutting) grazing regimes with different intensities (25% vs. 75%) and frequencies (I times vs. 3 times) over 35 days in Chwaka Bay (Zanzibar, Tanzania). The results showed that the two high-intensity treatments (75% removal) had 37-41% lower growth rate than the low-intensity/low-frequency treatment, and rhizome sugar and starch content were both affected in a similar way. A 36% lower starch content in the simulated low-intensity/high-frequency regime (25% x 3) compared to the one of low-intensity/low-frequency (25% x I) also shows an interaction between grazing intensity and frequency. This suggests that high-intensity (and to some extent frequency) grazing regimes, in comparison to low-intensity regimes, could negatively affect T. hemprichii growth, energy reserves, and thereby the ability to deal with additional stress like light limitation or grazing. (C) 2008 Elsevier B.V. All rights reserved.
|
|
