Development of superconducting wind turbine generators

Bogi B. Jensen, Nenad Mijatovic, and Asger B. Abrahamsen

In this paper, the commercial activities in the field of superconducting machines, particularly superconducting wind turbine generators, are reviewed and presented. Superconducting generators have the potential to provide a compact and light weight drive train at high torques and slow rotational speeds, because high magnetic fields can be produced by coils with very little loss.

J. Renewable Sustainable Energy 5, 023137 (2013)

Improved performance of vanadium redox battery using methylsulfonic acid solution as supporting electrolyte

Zhangxing He, Zhen Li, Zhi Zhou, Feiyue Tu, Yifan Jiang, Chunyue Pan, and Suqin Liu

Methylsulfonic acid (MSA) as supporting electrolyte for vanadium redox battery was studied and evaluated by thermal stability test, cyclic voltammetry, linear sweep voltammetry, and charge-discharge technique. The results show that the V(V)-MSA solution has better thermal stability than the sulfuric acid solutions, which may be due to the formation of VO(CH₃SO₃)₂ to prevent further condensation.

J. Renewable Sustainable Energy 5, 023130 (2013)

Nanoporous tin oxide photoelectrode prepared by electrochemical anodization in aqueous ammonia to improve performance of dye sensitized solar cell

Jun Jie Teh, Guan Hong Guai, Xuewan Wang, Kam Chew Leong, Chang Ming Li, and Peng Chen

In this work, a nanoporous thin film consisting of sieve-like tin oxide (SnO2) sheets was prepared by anodization of tin foil in aqueous ammonia and applied as a photoelectrode for dye-sensitized solar cell (DSSC). Compared to the conventional SnO2 nanoparticle-based photoelectrode, the anodized nanoporous SnO2 electrode offers higher short circuit current (6.85 vs. 3.64 mA/cm2) and open circuit voltage (0.56 vs. 0.51 V) due to better charge transportation and better suppression of charge recombination.

J. Renewable Sustainable Energy 5, 023120 (2013)

Validation of a FAST semi-submersible floating wind turbine numerical model with DeepCwind test data

Alexander J. Coulling, Andrew J. Goupee, Amy N. Robertson, Jason M. Jonkman, and Habib J. Dagher

There are global efforts in the offshore wind community to develop reliable floating wind turbine technologies that are capable of exploiting the abundant deepwater wind resource. These efforts require validated numerical simulation tools to predict the coupled aero-hydro-servo-elastic behavior of such systems.

J. Renewable Sustainable Energy 5, 023116 (2013)

Performance of hybrid compact filter system in a down-draft gasifier: An experimental study

Rameshkumar Ramasamy and Mayilsamy Kavandappa Gounder

Tar formation in biomass gasification is a major problem which in subsequent stages decomposes under the conditions such as temperature, pressure drop, gas flow rate, and retention time. Crucial review of literature discloses that all existing systems have maximum 90% tar removal capability.

J. Renewable Sustainable Energy 5, 013116 (2013)

Isotope effect in the photochemical decomposition of CO₂ (ice) by Lyman-α radiation

Chunqing Yuan and John T. Yates, Jr.

The photochemical decomposition of CO₂(ice) at 75 K by Lyman-α radiation (10.2 eV) has been studied using transmission infrared spectroscopy. An isotope effect in the decomposition of the CO₂ molecule in the ice has been discovered, favoring ¹²CO₂ photodecomposition over ¹³CO₂ by about 10%.

J. Chem. Phys. 138, 154302 (2013)

Nonlinear femtosecond laser induced scanning tunneling microscopy

Shirshendu Dey, Daniel Mirell, Alejandro Rodriguez Perez, Joonhee Lee, and V. Ara Apkarian

The authors demonstrate ultrafast laser driven nonlinear scanning tunneling microscopy (STM), under ambient conditions. The design is an adaptation of the recently introduced cross-polarized double beat method, whereby z-polarized phase modulated fields are tightly focused at a tunneling junction consisting of a sharp tungsten tip and an optically transparent gold film as substrate.

J. Chem. Phys. 138, 154202 (2013)

Planar junctionless transistor with non-uniform channel doping

Partha Mondal, Bahniman Ghosh, and Punyasloka Bal

The authors propose a planar junctionless transistor (JLT) in silicon-on-insulator (SOI) with non-uniform channel doping in vertical direction to improve the ON to OFF drain current ratio. In single gate JLT in SOI, a thin device layer is depleted in the off-state from the top of the layer and the leakage current flows through bottom of the device layer, and the leakage current depends on the device layer thickness.

Appl. Phys. Lett. 102, 133505 (2013) | HTML | PDF

Band alignment in SnS thin-film solar cells: Possible origin of the low conversion efficiency

Lee A. Burton and Aron Walsh

Tin sulfide is an attractive absorber material for low-cost thin-film solar cells. Despite the ideal physical properties of bulk SnS, the photovoltaic conversion efficiencies achieved in devices to date have been no greater than 2%.

Appl. Phys. Lett. 102, 132111 (2013) | HTML | PDF

Tuning magnetic anisotropy in (001) oriented L1₀ (Fe_1−xCux)₅₅Pt₄₅ films

Dustin A. Gilbert, Liang-Wei Wang, Timothy J. Klemmer, Jan-Ulrich Thiele, Chih-Huang Lai, and Kai Liu

The authors have achieved (001) oriented L10 (Fe_1−xCu_x)₅₅Pt₄₅ thin films, with magnetic anisotropy up to 3.6 × 10⁷ erg/cm³, using atomic-scale multilayer sputtering and post annealing at 400 °C for 10 s. By fixing the Pt concentration, structure and magnetic properties are systematically tuned by the Cu addition.

Appl. Phys. Lett. 102, 132406 (2013) | HTML | PDF