| 1. |
- Bououdina, M., et al.
(författare)
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Lithium storage in amorphous TiNi hydride : Electrode for rechargeable lithium-ion batteries
- 2013
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Ingår i: Materials Chemistry and Physics. - : Elsevier BV. - 0254-0584 .- 1879-3312. ; 141:1, s. 348-354
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Tidskriftsartikel (refereegranskat)abstract
- In this study, amorphous TiNi phase was successfully prepared using mechanically milling for a very short time of 8 h. HRTEM confirms the formation of amorphous phase with the presence of nanocrystalline Fe particles. After hydrogenation (30 bars of H-2 for a duration of 2 h), the electrochemical reaction shows that TiNi hydride/Li cell discharges at a current of one Li for 10 h between 3 V and 0.005 V. The discharge of TiNiH electrode around x = 1 Li corresponds to a capacity of 251 mAh g(-1) and a hydride composition of TiNiH1.0 at an average voltage of 0.4 V. Ex-situ X-ray diffraction pattern collected at the end of the discharge shows a mixture of amorphous TiNi compound and LiH. A general mechanism for the electrochemical reaction is then proposed: alpha-TiNiH + Li+ + e(-) -> alpha-TiNi + LiH. The results from DFT calculations yield an average cell voltage of 0.396 V, which is in good agreement with the experimental pseudo-plateau occurring at 0.4 V.
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| 2. |
- Curtin, W. A., et al.
(författare)
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Hybrid discrete dislocation models for fatigue crack growth
- 2010
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Ingår i: International Journal of Fatigue. - : Elsevier BV. - 1879-3452 .- 0142-1123. ; 32:9, s. 1511-1520
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Tidskriftsartikel (refereegranskat)abstract
- A framework for accurately modeling fatigue crack growth in ductile crystalline solids is necessarily multiscale The creation of new free surface occurs at the atomistic scale, where the material's cohesive strength is controlled by the local chemistry On the other hand, significant dissipation during fatigue crack growth takes place at a size scale that can be modeled appropriately by conventional continuum mechanics. The intermediate size scale where the discreteness of dislocations comes Into play is the main origin of the hysteresis needed for fatigue and of the high stresses required for atomistic separation to take place. We focus on recent developments which permit analyses of fatigue crack growth involving the direct coupling of disparate size scales. Although no analyses have been carried out directly coupling size scales from the atomic to the conventional continuum, the ingredients to do so are in place. We provide background that illustrates the key role played by the intermediate discrete dislocation size scale and review steps that have been taken to permit direct size scale coupling. The prospects and modeling needs for further developments are also discussed (C) 2009 Elsevier Ltd All rights reserved.
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| 3. |
- Pandian, J. D., et al.
(författare)
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Low-noise 6-8 GHz receiver
- 2006
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Ingår i: IEEE Microwave Magazine. - 1527-3342 .- 1557-9581. ; 7:6, s. 74-84
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Tidskriftsartikel (refereegranskat)
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| 4. |
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| 5. |
- Maji, K. J., et al.
(författare)
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Assessment of city level human health impact and corresponding monetary cost burden due to air pollution in India taking Agra as a model city
- 2017
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Ingår i: Aerosol and Air Quality Research. - : Taiwan Association for Aerosol Research. - 1680-8584 .- 2071-1409. ; 17:3, s. 831-842
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Tidskriftsartikel (refereegranskat)abstract
- Objectives of the present study are to provide quantitative estimations of air pollution health impacts and monetary burden on people living in Agra city, the fourth most populated city in Uttar Pradesh, India. To estimate the direct health impacts of air pollution in Agra city during year 2002 to 2014, ‘Risk of Mortality/Morbidity due to Air Pollution’ model was used which is adopted from air quality health impact assessment software, developed by world health organization (WHO). Concentrations of NO2, SO2 and PM10 have been used to assess human health impacts in terms of attributable proportion of the health outcome as- annual number of excess cases of total mortality, cardiovascular mortality, respiratory mortality, hospital admission chronic obstructive pulmonary disease (COPD), hospital admission respiratory disease and hospital admission cardiovascular disease and it was observed that attributable number of cases were 1325, 908, 155, 138, 1230 and 348 respectively in year 2002. However, after thirteen years these figures increased to 1607, 1095, 189, 167, 1568 and 394 respectively. From these results, it was observed that from 2002 to 2014, the attributable number of cases increased almost by 13.43 to 27.52%. As a result, the monetary cost burden due to air pollution related health effects also increased very highly; it was 67.99 million US$ in 2002, which transformed into 254.52 million US$ in 2014. In future, if air quality continues to follow current pollutant concentration trend, the monetary cost burden will reach a level of US$ 570.12 million in year 2020, which is not only a thoughtful matter but also a threatful matter and it signifies the importance of rectification measures for air quality in Agra city.
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| 6. |
- Deshpande, Srikanth, et al.
(författare)
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Effect of spanwise variation of chord on the performance of a turbine cascade
- 2017
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Ingår i: Turbomachinery. - 9780791850787 ; 2A-2017
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Konferensbidrag (refereegranskat)abstract
- This paper compares the aerodynamic performance of two cascade designs, viz.: -constant-chord and varying-chord. The varying-chord design is typical of industrial gas turbines and steam turbine stators in order to reduce manufacturing costs. The present study aims to increase the understanding of the implications of this manufacturing constraint on the aerodynamics of the stator. Experiments are carried out in a linear cascade wind tunnel. Numerical simulations are performed using commercial code CFX. The profile losses and secondary losses in the two designs are compared. The overall total pressure losses indicate better aerodynamic performance of a turbine cascade with constant chord as compared to a turbine cascade of varying-chord design
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| 7. |
- Kazemahvazi, Sohrab, 1981-, et al.
(författare)
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Dynamic failure of clamped circular plates subjected to an underwater shock
- 2007
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Ingår i: Journal of Mechanics of Materials and Structures. - : Mathematical Sciences Publishers. - 1559-3959. ; 2:10, s. 2007-2023
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Tidskriftsartikel (refereegranskat)abstract
- Clamped circular copper plates have been subjected to exponentially decaying underwater blast waves with peak pressures in the range 10MPa to 300MPa and decay constants varying between 0.05ms to 1.1 ms. The deformation and failure modes were observed by high-speed photography. For the thin plates considered in this study, the failure modes were primarily governed by the peak pressures and were reasonably independent of the blast wave decay constant. Three modes of deformation and failure were identified. At low pressures, the plates undergo bending and stretching without rupture (mode I). At intermediate pressures a range of tensile tearing modes were observed, from petalling failures to tearing at the supports with increasing blast pressures. These tearing modes are referred to as mode II failures. At the highest pressures investigated here, the plate tears at the supports in a manner that is reminiscent of a shear-off failure. This failure is labeled as mode III. Scanning electron micrographs of the failure surfaces showed that in all cases, the local failure mechanism was tensile necking. Finite element (FE) simulations employing a local shear failure criterion are used to model the rupture of the material. Appropriately calibrated FE models capture all failure modes with sufficient fidelity.
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