1. |
- Ahmed, K. M., et al.
(författare)
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Implementation of arsenic mitigation : Insights from Araihazar and Matlab – two extensively studied areas in Bangladesh
- 2018
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Ingår i: Environmental Arsenic in a ChangingWorld - 7th International Congress and Exhibition Arsenic in the Environment, 2018. - London : CRC Press/Balkema. - 9781138486096 ; , s. 565-566
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Konferensbidrag (refereegranskat)abstract
- Despite many efforts over the last 25 years, millions of people are still drinking groundwater having arsenic above Bangladesh and World Health Organization limits. This can be linked, to some extent, to a lack of pragmatic policies and implementation strategies. Important lessons have been learned from extensive studies in Araihazar and Matlab in Bangladesh. Also better mitigation strategies for reducing arsenic exposure have been demonstrated at both locations. New policy and mitigation strategies should focus on mapping using mobile technology for village scale mapping. Dissemination of test result is extremely important in increasing awareness of the users and a new three-color scheme (Blue, Green, Red corresponding to <10, 10–50, and >50 µg L−1) instead of existing Red-Green color scheme should be adopted to lower arsenic intake. Safe wells can be installed at appropriate locations and depth by combining hydrogeological and social criteria aided by applications-based score ranking.
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2. |
- Haglund, Erik, 1985, et al.
(författare)
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30 GHz bandwidth 850 nm VCSEL with sub-100 fJ/bit energy dissipation at 25-50 Gbit/s
- 2015
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Ingår i: Electronics Letters. - : Institution of Engineering and Technology (IET). - 1350-911X .- 0013-5194. ; 51:14, s. 1096-1097
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Tidskriftsartikel (refereegranskat)abstract
- A high-speed and energy-efficient oxide-confined 850 nm vertical-cavity surface-emitting laser (VCSEL) for optical interconnects is presented. A record-high modulation bandwidth of 30 GHz is reached for a 3.5 mu m oxide aperture VCSEL, with 25 GHz bandwidth already at a bias current of 1.8 mA. The high bandwidth at low currents enables energy-efficient transmission with a dissipated heat energy in the VCSEL of
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3. |
- Marchitto, Thomas M., et al.
(författare)
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Dynamical Response of the Tropical Pacific Ocean to Solar Forcing During the Early Holocene
- 2010
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Ingår i: Science. - : American Association for the Advancement of Science (AAAS). - 1095-9203 .- 0036-8075. ; 330:6009, s. 1378-1381
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Tidskriftsartikel (refereegranskat)abstract
- We present a high-resolution magnesium/calcium proxy record of Holocene sea surface temperature (SST) from off the west coast of Baja California Sur, Mexico, a region where interannual SST variability is dominated today by the influence of the El Nino-Southern Oscillation (ENSO). Temperatures were lowest during the early to middle Holocene, consistent with documented eastern equatorial Pacific cooling and numerical model simulations of orbital forcing into a La Nina-like state at that time. The early Holocene SSTs were also characterized by millennial-scale fluctuations that correlate with cosmogenic nuclide proxies of solar variability, with inferred solar minima corresponding to El Nino-like (warm) conditions, in apparent agreement with the theoretical "ocean dynamical thermostat" response of ENSO to exogenous radiative forcing.
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4. |
- Treviño Morales, Sandra, 1985, et al.
(författare)
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Dynamics of cluster-forming hub-filament systems The case of the high-mass star-forming complex Monoceros R2
- 2019
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Ingår i: Astronomy and Astrophysics. - : EDP Sciences. - 0004-6361 .- 1432-0746. ; 629
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Tidskriftsartikel (refereegranskat)abstract
- Context. High-mass stars and star clusters commonly form within hub-filament systems. Monoceros R2 (hereafter Mon R2), at a distance of 830 pc, harbors one of the closest of these systems, making it an excellent target for case studies. Aims. We investigate the morphology, stability and dynamical properties of the Mon R2 hub-filament system. Methods. We employed observations of the (CO)-C-13 and (CO)-O-18 1 -> 0 and 2 -> 1 lines obtained with the IRAM-30m telescope. We also used H-2 column density maps derived from Herschel dust emission observations. Results. We identified the filamentary network in Mon R-2 with the DisPerSE algorithm and characterized the individual filaments as either main (converging into the hub) or secondary (converging to a main filament). The main filaments have line masses of 30-100 M-circle dot pc(-1) and show signs of fragmentation, while the secondary filaments have line masses of 12-60 M-circle dot pc(-1) and show fragmentation only sporadically. In the context of Ostriker's hydrostatic filament model, the main filaments are thermally supercritical. If non-thermal motions are included, most of them are transcritical. Most of the secondary filaments are roughly transcritical regardless of whether non-thermal motions are included or not. From the morphology and kinematics of the main filaments, we estimate a mass accretion rate of 10(-4)-10(-3) M-circle dot yr(-1) into the central hub. The secondary filaments accrete into the main filaments at a rate of 0.1-0.4 x 10(-4) M-circle dot yr(-1). The main filaments extend into the central hub. Their velocity gradients increase toward the hub, suggesting acceleration of the gas. We estimate that with the observed infall velocity, the mass-doubling time of the hub is similar to 2.5 Myr, ten times longer than the free-fall time, suggesting a dynamically old region. These timescales are comparable with the chemical age of the HII region. Inside the hub, the main filaments show a ring-or a spiral-like morphology that exhibits rotation and infall motions. One possible explanation for the morphology is that gas is falling into the central cluster following a spiral-like pattern.
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5. |
- Westbergh, Petter, 1981, et al.
(författare)
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High-speed 850 nm VCSELs with 28 GHz modulation bandwidth operating error-free up to 44 Gbit/s
- 2012
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Ingår i: Electronics Letters. - : Institution of Engineering and Technology (IET). - 1350-911X .- 0013-5194. ; 48:18, s. 1145-U178
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Tidskriftsartikel (refereegranskat)abstract
- A new generation of high-speed oxide confined 850 nm vertical cavity surface-emitting lasers is presented. A record high modulation bandwidth of 28 GHz is achieved and error-free data transmission at bit-rates up to 44 Gbit/s is demonstrated.
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6. |
- Westbergh, Petter, 1981, et al.
(författare)
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High-Speed Oxide Confined 850-nm VCSELs Operating Error-Free at 40 Gb/s up to 85 degrees C
- 2013
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Ingår i: IEEE Photonics Technology Letters. - 1041-1135 .- 1941-0174. ; 25:8, s. 768-771
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Tidskriftsartikel (refereegranskat)abstract
- We present the temperature dependence of the performance characteristics of our latest generation high-speed oxide confined 850-nm vertical cavity surface-emitting lasers (VCSELs). Using a 7-mu m oxide aperture diameter VCSEL, we demonstrate a maximum modulation bandwidth of similar to 27 GHz at room temperature and similar to 21 GHz at 85 degrees C. With a new highspeed optical receiver, these bandwidths enable error-free data transmission ( defined as a bit-error-rate
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