| 1. |
- Corrêa, Gregório B., et al.
(författare)
-
Raman characterization of single-crystalline Ga0.96Mn0.04As:Zn nanowires realized by ion-implantation
- 2019
-
Ingår i: Nanotechnology. - Bristol : IOP Publishing. - 0957-4484 .- 1361-6528. ; 30:33
-
Tidskriftsartikel (refereegranskat)abstract
- Recent progress in the realization of magnetic GaAs nanowires (NWs) doped with Mn has attracted a lot of attention due to their potential application in spintronics. In this work, we present a detailed Raman investigation of the structural properties of Zn doped GaAs (GaAs:Zn) and Mn-implanted GaAs:Zn (Ga0.96Mn0.04As:Zn) NWs. A significant broadening and redshift of the optical TO and LO phonon modes are observed for these NWs compared to as-grown undoped wires, which is attributed to strain induced by the Zn/Mn doping and to the presence of implantation-related defects. Moreover, the LO phonon modes are strongly damped, which is interpreted in terms of a strong LO phonon-plasmon coupling, induced by the free hole concentration. Moreover, we report on two new interesting Raman phonon modes (191 and 252 cm-1) observed in Mn ion-implanted NWs, which we attribute to Eg (TO) and A1g (LO) vibrational modes in a sheet layer of crystalline arsenic present on the surface of the NWs. This conclusion is supported by fitting the observed Raman shifts for the SO phonon modes to a theoretical dispersion function for a GaAs NW capped with a dielectric shell.
|
|
| 2. |
- Gupta, Anil, et al.
(författare)
-
Patient controlled regional analgesia after carpal tunnel release: a double-blind study using distal perineural catheters
- 2011
-
Ingår i: JOURNAL OF HAND SURGERY-EUROPEAN VOLUME. - : Elsevier Science B. V., Amsterdam. - 1753-1934 .- 2043-6289. ; 36E:3, s. 219-225
-
Tidskriftsartikel (refereegranskat)abstract
- This study was done to assess the efficacy of a perineural catheter for pain relief following carpal tunnel release (CTR). Sixty-six patients undergoing open CTR under local anaesthesia (LA) were randomly divided into three groups: Groups A and B had a perineural catheter and Group C served as non-blinded control group. Postoperative pain relief was by self-administration of either ropivacaine (Group A) or saline (Group B) via an elastometric pump and by oral paracetamol in Group C. Patients in Group A had a significantly greater difference in summed pain intensity than Group B. Fewer patients in Group A requested supplementary analgesics than in Group C. Patient satisfaction was higher in Group A than in Group B on day 1. However better analgesia was not associated with better functional recovery.
|
|
| 3. |
- Håkansson, Stellan, et al.
(författare)
-
Real-time PCR-assay in the delivery suite for determination of group B streptococcal colonization in a setting with risk-based antibiotic prophylaxis
- 2014
-
Ingår i: Journal of Maternal-Fetal & Neonatal Medicine. - : Informa UK Limited. - 1476-7058 .- 1476-4954. ; 27:4, s. 328-332
-
Tidskriftsartikel (refereegranskat)abstract
- Objective: Intrapartum antibiotic prophylaxis (IAP) reduces the incidence of neonatal early onset group B streptococcal infections. The present study investigated if an automated PCR-assay, used bedside by the labor ward personnel was manageable and could decrease the use of IAP in a setting with a risk-based IAP strategy. Methods: The study comprises two phases. Phase 1 was a multicenter, randomized, controlled trial. Women with selected risk-factors were allocated either to PCR-IAP (prophylaxis given if positive or indeterminate) or IAP. A vaginal/rectal swab and superficial swabs from the neonate for conventional culture were also obtained. Phase 2 was non-randomized, assessing an improved version of the assay. Results: Phase 1 included 112 women in the PCR-IAP group and 117 in the IAP group. Excluding indeterminate results, the assay showed a sensitivity of 89% and a specificity of 90%. In 44 % of the PCR assays the result was indeterminate. The use of IAP was lower in the PCR group (53 versus 92%). Phase 2 included 94 women. The proportion of indeterminate results was reduced (15%). The GBS colonization rate was 31%. Conclusion: The PCR assay, in the hands of labor ward personnel, can be useful for selection of women to which IAP should be offered.
|
|
| 4. |
- Kumar, Sandeep, et al.
(författare)
-
Evaluation of carrier density and mobility in Mn ion-implanted GaAs:Zn nanowires by Raman spectroscopy
- 2020
-
Ingår i: Nanotechnology. - Bristol : IOP Publishing. - 0957-4484 .- 1361-6528. ; 31:20
-
Tidskriftsartikel (refereegranskat)abstract
- The fabrication of complex nanoscale electronics with reduced dimensions poses challenges on novel techniques to accurately determine fundamental electronic parameters. In this article, we present a universal contactless method based on Raman scattering for measuring the mobility and hole concentration independently in GaAs:Zn and Mn ion-implanted GaAs:Zn nanowires, potentially of great interest for spintronics applications. Clear coupled longitudinal optical phonon-plasmon modes were recorded and fitted with a dielectric function, based on the Drude model, which includes contributions from both plasmons and phonons. From the fitting, we extract accurate values of the plasma frequency and plasma damping constant from which we directly calculate the hole density and mobility, respectively. The extracted mobilities were also used as input data for analysis of complementary four-probe transport measurements, where the corresponding hole concentrations could be calculated and found to be in good agreement with those extracted directly from the Raman data. We also investigated the influence of annealing of the GaAs:Zn nanowires on the hole concentration and mobility and found strong indications of thermally activated defects related to a formed crystalline As/oxide shell around the nanowires. The method proposed here is extremely powerful for the characterization of nanoelectronics in general, and nanospintronics in particular for which Hall measurements are difficult to pursue due to problems related to contact formation, as well as to inherent magnetic properties of the devices.
|
|
| 5. |
- Pettersson, Sven-Göran, et al.
(författare)
-
Light-in-flight recording. 6: Experiment with view-time expansion using a skew reference wave
- 1989
-
Ingår i: Applied Optics. - 2155-3165. ; 28:4, s. 766-770
-
Tidskriftsartikel (refereegranskat)abstract
- In normal light-in-flight holography the largest time difference that can be created in the image is when the reference light falls nearly parallel with the photographic plate. In that case, where the pulse front is perpendicular to the direction of propagation, the time scale on the plate is given by the speed of light. Thus the time it takes for the reference light to go from one side of the plate to the other sets the upper limit of the observable time interval. By using a reference light where the pulse front is leaning backward, this view time can be increased several times.
|
|
| 6. |
|
|
| 7. |
- Vieider, Christian, et al.
(författare)
-
Low-cost far infrared bolometer camera for automotive use
- 2007
-
Ingår i: P SOC PHOTO-OPT INSTRUM ENG. - : SPIE. - 9780819466648 ; , s. 5421-5421
-
Konferensbidrag (refereegranskat)abstract
- A new low-cost long-wavelength infrared bolometer camera system is under development. It is designed for use with an automatic vision algorithm system as a sensor to detect vulnerable road users in traffic. Looking 15 in in front of the vehicle it can in case of an unavoidable impact activate a brake assist system or other deployable protection system. To achieve our cost target below epsilon 100 for the sensor system we evaluate the required performance and can reduce the sensitivity to 150 mK and pixel resolution to 80 x 30. We address all the main cost drivers as sensor size and production yield along with vacuum packaging, optical components and large volume manufacturing technologies. The detector array is based on a new type of high performance thermistor material. Very thin Si/SiGe single crystal multi-layers are grown epitaxially. Due to the resulting valence barriers a high temperature coefficient of resistance is achieved (3.3%/K). Simultaneously, the high quality crystalline material provides very low 1/f-noise characteristics and uniform material properties. The thermistor material is transferred from the original substrate wafer to the read-out circuit using adhesive wafer bonding and subsequent thinning. Bolometer arrays can then be fabricated using industry standard MEMS process and materials. The inherently good detector performance allows us to reduce the vacuum requirement and we can implement wafer level vacuum packaging technology used in established automotive sensor fabrication. The optical design is reduced to a single lens camera. We develop a low cost molding process using a novel chalcogenide glass (GASIR (R) 3) and integrate anti-reflective and anti-erosion properties using diamond like carbon coating.
|
|
