| 1. |
- Javed, Muhammad Sufyan, et al.
(författare)
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Electrochemical studies of perovskite cathode material for direct natural gas fuel cell
- 2016
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Ingår i: International journal of hydrogen energy. - : Elsevier. - 0360-3199 .- 1879-3487. ; 41:4, s. 3072-3078
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Tidskriftsartikel (refereegranskat)abstract
- Natural gas is the most promising renewable energy source and its widespread availability ensured its importance for early applications in stationary fuel cells as a reliable and low cost fuel. Therefore it is very important to efficiently utilization of natural gas in low temperature fuel cells. Herein, we demonstrate the synthesis of perovskite material of Yttrium doped Sr0.92FexTi1-xO3-delta (x = 0.25, 030) (YSFT) by solid state reaction method and further investigated as a new cathode material for a low temperature solid oxide fuel cell fueled by natural gas. The YSFT is characterized by X-ray powder diffraction, Brunauer-Emmett-Teller and scanning electron microscopy. The perovskite structure is achieved at relatively low temperature (850 degrees C). The average crystalline size is found 28 nm and 36 nm for x = 0.25 and 0.30 respectively. TGA results showed the lattice oxygen loss of YSFT is about 0.206% in its original weight in the temperature range of 25-1000 degrees C. The maximum electronic conductivities of 2.3 Scm(-1) and 2.07 Scm(-1) are achieved for x = 025 and x = 0.30 at 550 degrees C in air atmosphere respectively. It is observed that the oxygen reduction is enhanced due to the perovskite crystal structure and oxygen vacancies play an important role in the redox reaction to improve the performance of fuel cell. The YSFT perovskite cathode material based fuel cell with natural gas have achieved the power density of 250 mWcm(-2) for x = 025 at 550 degrees C. The fuel cell device has demonstrated very stable results by running continuously for 5 h with domestic available natural gas.
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| 2. |
- Khan, Muhammad Ahsan Iqbal, et al.
(författare)
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An Experimental and Comparative Performance Evaluation of a Hybrid Photovoltaic-Thermoelectric System
- 2021
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Ingår i: Frontiers in Energy Research. - : FRONTIERS MEDIA SA. - 2296-598X. ; 9
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Tidskriftsartikel (refereegranskat)abstract
- The majority of incident solar irradiance causes thermalization in photovoltaic (PV) cells, attenuating their efficiency. In order to use solar energy on a large scale and reduce carbon emissions, their efficiency must be enhanced. Effective thermal management can be utilized to generate additional electrical power while simultaneously improving photovoltaic efficiency. In this work, an experimental model of a hybrid photovoltaic-thermoelectric generation (PV-TEG) system is developed. Ten bismuth telluride-based thermoelectric modules are attached to the rear side of a 10 W polycrystalline silicon-based photovoltaic module in order to recover and transform waste thermal energy to usable electrical energy, ultimately cooling the PV cells. The experiment was then carried out for 10 days in Lahore, Pakistan, on both a simple PV module and a hybrid PV-TEG system. The findings revealed that a hybrid system has boosted PV module output power and conversion efficiency. The operating temperature of the PV module in the hybrid system is reduced by 5.5%, from 55 degrees C to 52 degrees C. Due to a drop in temperature and the addition of some recovered energy by thermoelectric modules, the total output power and conversion efficiency of the system increased. The hybrid system's cumulative output power increased by 19% from 8.78 to 10.84 W, compared to the simple PV system. Also, the efficiency of the hybrid PV-TEG system increased from 11.6 to 14%, which is an increase of 17% overall. The results of this research could provide consideration for designing commercial hybrid PV-TEG systems.
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| 3. |
- Javed, Muhammad Ahsan, et al.
(författare)
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Impact of intensified chemotherapy in metastatic pancreatic ductal adenocarcinoma (PDAC) in clinical routine in Europe
- 2019
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Ingår i: Pancreatology (Print). - : Elsevier. - 1424-3903 .- 1424-3911. ; 19:1, s. 97-104
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Pancreatic ductal adenocarcinoma (PDAC) is associated with poor prognosis. Gemcitabine is the standard chemotherapy for patients with metastatic pancreatic adenocarcinoma (MPA). Randomized clinical trials evaluating intensified chemotherapies including FOLFIRINOX and nab-paclitaxel plus gemcitabine (NAB+GEM) have shown improvement in survival. Here, we have evaluated the efficacy of intensified chemotherapy versus gemcitabine monotherapy in real-life settings across Europe.METHODS: A retrospective multi-center study including 1056 MPA patients, between 2012 and 2015, from nine centers in UK, Germany, Italy, Hungary and the Swedish registry was performed. Follow-up was at least 12 months. Cox proportional Harzards regression was used for uni- and multivariable evaluation of prognostic factors.RESULTS: Of 1056 MPA patients, 1030 (98.7%) were assessable for survival analysis. Gemcitabine monotherapy was the most commonly used regimen (41.3%), compared to FOLFIRINOX (n = 204, 19.3%), NAB+GEM (n = 81, 7.7%) and other gemcitabine- or 5-FU-based regimens (n = 335, 31.7%). The median overall survival (OS) was: FOLFIRINOX 9.9 months (95%CI 8.4-12.6), NAB+GEM 7.9 months (95%CI 6.2-10.0), other combinations 8.5 months (95%CI 7.7-9.3) and gemcitabine monotherapy 4.9 months (95%CI 4.4-5.6). Compared to gemcitabine monotherapy, any combination of chemotherapeutics improved the survival with no significant difference between the intensified regimens. Multivariable analysis showed an association between treatment center, male gender, inoperability at diagnosis and performance status (ECOG 1-3) with poor prognosis.CONCLUSION: Gemcitabine monotherapy was predominantly used in 2012-2015. Intensified chemotherapy improved OS in comparison to gemcitabine monotherapy. In real-life settings, the OS rates of different treatment approaches are lower than shown in randomized phase III trials.
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