880 research outputs found
The early life of the first student of the M.A.O. college,
No full textIncludes "Unrest in India" by Afzal-ul-Ulema Nawab Sarbulang Jung Mahomed Hameed-Ullah Khan, Chief Justice, Hyderabad, Deccan p. 15-25 (2d group)Includes some unpublished extracts from Mahomed Ullah's diary.Cover title lacking.Mode of access: Internet
Horizontal Sustained Force Delivery with an Aerial Manipulator Using Hybrid Force/Position Control
No full textThis paper introduces a novel hybrid force/position control system tailored for aerial manipulators, aiming to enable efficient and sustained delivery of horizontal forces. Unlike existing approaches mainly designed for ground-fixed manipulators, this architecture is specifically developed for aerial robotics. By leveraging physics-engine based simulations, the proposed system demonstrates effectiveness in generating large controlled forces over extended periods, improving comparable hybrid controllers documented in the literature. These findings offer valuable insights for optimizing aerial manipulators, particularly in scenarios necessitating prolonged horizontal force exertion. The study’s contributions hold promise for various applications, including search and rescue operations, infrastructure maintenance, and environmental monitoring, thereby driving advancements in aerial manipulation technologies
Finite sample econometrics / Aman Ullah.
No full texteconomic&political bookfair2015Includes bibliographical references (p. 199-225) and index.x, 230 pages
Investigating soliton phenomena in incompressible fluids: Study of the (2+1)-dimensional Boiti–Leon–Manna–Pempinelli equation
No full textPushing and Rotating a Heavy Mass Rigid Body Using an Omnidirectional Aerial Manipulator
No full textThis paper presents the pushing and rotation of a heavy rigid body using an omnidirectional actively tilted aerial manipulator, controlled via a hybrid force/position controller. Unlike conventional unmanned aerial vehicles, the proposed system enables precise horizontal force application, making it ideal for aerial physical interaction tasks. The hybrid controller is implemented in the Robot Operating System and validated through extensive simulations in a Gazebo physics-engine-based environment. The manipulator's performance was evaluated in two scenarios: circular trajectory tracking and the rotation of a heavy rigid mass. Results demonstrated its capability to follow complex trajectories with high accuracy and exert sustained forces for object manipulation. The system exhibited excellent stability and precision, underscoring its potential for real-world applications in challenging environments
SHANGHAI COOPERATION ORGANISATION AND AFGHANISTAN: INTERESTS AND LIMITATIONS
No full textShanghai Cooperation Organisation has greater relevance in Afghanistan because of its strategic importance and geographic proximity. For years, the country has harboured numerous extremist groups and insurgents. It has remained a battleground for US-led coalition forces and the Taliban for about two decades. Despite efforts by the US and its allies, peace has yet to be restored in Afghanistan, and the responsibility now rests on regional countries. It is crucial for these states, especially Eurasian nations, to work together to stabilise the war-torn country and bring lasting peace to the region. Therefore, the study examines the push and pull factors of the Shanghai Cooperation Organisation’s interests in Afghanistan and the challenges that come with implementing their peace plans. The data has been collected from various primary and secondary sources, including websites, newspapers and research articles. The paper also highlights two major concerns for the Shanghai Cooperation Organisation, the economic crisis in Afghanistan and the international recognition of the Taliban government.
Bibliography Entry
Khan, Hameed Ullah, Muhammad Farooq Shah and Muhammad Ilyas Khan. 2023. "Shanghai Cooperation Organisation and Afghanistan: Interests and Limitations." Margalla Papers 27 (1): 82-95
Numerical analysis a guide to improve the efficiency of experimentally designed solar cell
No full text[EN] In this paper a numerical modelling guide is proposed about how to improve the efficiency of experimentally designed solar cells with the aid of numerical analysis. To validate the study presented in this paper, we first reproduce the results for experimentally designed solar cell in SCAPS with solar cell structure p-SnS/n-CdS having a conversion efficiency of 1.5%. After this device performance was optimized in solar cell capacitance simulator (SCAPS) by changing absorber layer thickness, buffer layer thickness, minority carrier lifetime, absorber acceptor doping concentration, buffer donor doping concentration and adding window layer. After optimization of physical device parameters and structure the new solar cell structure p-SnS/n-CdS/n-ZnO achieves power conversion efficiency (PCE) of 14.01% in SCAPS.This work was supported by Ministerio de Economia y Competitividad (ENE2016-77798-C4-2-R) and Generalitat valenciana (Prometeus 2014/044).Baig, F.; Khattak, YH.; Ullah, S.; Marí, B.; Ullah, H. (2018). Numerical analysis a guide to improve the efficiency of experimentally designed solar cell. Applied Physics A. 124(7). https://doi.org/10.1007/s00339-018-1877-xS1247M.A. Green et al., Solar cell efficiency tables (version 50). Prog. Photovolt. Res. Appl. 25(7), 668–676 (2017)L. Vinet, A. Zhedanov, A ‘missing’ family of classical orthogonal polynomials. Science (80-.), 348(6240), 1234–1237 (2010)J. You et al., Improved air stability of perovskite solar cells via solution-processed metal oxide transport layers. Nat. Nanotechnol. 11(1), 75–81 (2016)C. Yan et al., Beyond 11% efficient sulfide kesterite Cu2ZnxCd1−xSnS4 solar cell: effects of cadmium alloying. ACS Energy Lett. 2(4), 930–936 (2017)T. Minemoto, S. Harada, H. Takakura, SnS thin film solar cells with Zn1−xMgxO buffer layers. Curr. Appl. Phys. 12(1), 171–173 (2012)H. Fu, Environment-friendly and earth-abundant colloidal chalcogenide nanocrystals for photovoltaic applications. J. Mater. Chem. C. 6(3), 414–445 (2017)A. Zakutayev, V. Stevanovic, S. Lany, Non-equilibrium alloying controls optoelectronic properties in Cu2O thin films for photovoltaic absorber applications. Appl. Phys. Lett. 106(12), 123903 (Mar. 2015)M. Mousavi-Kamazani, Z. Zarghami, M. Salavati-Niasari, Facile and novel chemical synthesis, characterization, and formation mechanism of copper sulfide (Cu2S, Cu2S/CuS, CuS) nanostructures for increasing the efficiency of solar cells. J. Phys. Chem. C 120(4), 2096–2108 (2016)V.R. Minnam Reddy, S. Gedi, C. Park, M. R.w, and R.R. Ramakrishna, Development of sulphurized SnS thin film solar cells. Curr. Appl. Phys. 15(5), 588–598 (2015)J.A. Andrade-Arvizu, M. Courel-Piedrahita, O. Vigil-Galán, SnS-based thin film solar cells: perspectives over the last 25 years. J. Mater. Sci. Mater. Electron. 26(7), 4541–4556 (2015)P. Sinsermsuksakul et al., Overcoming efficiency limitations of SnS-based solar cells. Adv. Energy Mater. 4(15), 1–7 (2014)W. Albers, C. Haas, F. Van Der Maesen, The preparation and the optical properties of electrical and SnS crystals. J. Phys. Chem. Solids 15(3–4), 306–310 (1960)M.M. Nassary, Temperature dependence of the electrical conductivity, Hall effect and thermoelectric power of SnS single crystals. J. Alloy. Compd. 398(1–2), 21–25 (2005)P.K. Nair, A.R. Garcia-Angelmo, M.T.S. Nair, Cubic and orthorhombic SnS thin-film absorbers for tin sulfide solar cells. Phys. Status Solidi Appl. Mater. Sci. 213(1), 170–177 (2016)A. Niemegeers, M. Burgelman, Modelling of AC-characteristics solar cells. In 1996 22nd IEEE Photovoltaics Specialists Conference, pp. 901–904, April 1996M. Burgelman, P. Nollet, S. Degrave, Modelling polycrystalline semiconductor solar cells. Thin Solid Films 361, 527–532 (2000)Y.H. Khattak, F. Baig, S. Ullah, B. Marí, S. Beg, H. Ullah, Numerical modeling baseline for high efficiency (Cu2FeSnS4) CFTS based thin film kesterite solar cell. Optik (Stuttg) 164, 547–555 (2018)Y.H. Khattak, F. Baig, S. Ullah, B. Marí, S. Beg, H. Ullah, Enhancement of the conversion efficiency of thin film kesterite solar cell. J. Renew. Sustain. Energy 10(3), 33501 (2018)H. Ullah, B. Marí, Numerical analysis of SnS based polycrystalline solar cells. Superlattices Microstruct. 72, 148–155 (2014)S. Lin et al., Numerical analysis of SnS homojunction solar cell. Superlattices Microstruct. 91, 375–382 (2016)J. Xu, Y. Yang, Study on the performances of SnS heterojunctions by numerical analysis. Energy Convers. Manag. 78, 260–265 (2014)F. Baig, H. Ullah, Y.H. Khattak, B. Mari Soucase, Numerical analysis of SnS photovoltaic cells. In: Proceedings of 2016 International Renewable and Sustainable Energy Conference IRSEC 2016, pp. 596–600, 2017R. Chakraborty, V. Steinmann, N.M. Mangan, R.E. Brandt, J.R. Poindexter, R. Jaramillo, J.P. Mailoa, K. Hartman, A. Polizzotti, C. Yang, R.G. Gordon, T. Buonassisi, Non-monotonic effect of growth temperature on carrier collection in SnS solar cells. Appl. Phys. Lett. 106, 203901 (2015)K.T. Ramakrishna Reddy, P.A. Nwofe, R.W. Miles, Determination of the minority carrier diffusion length of SnS using electro-optical measurements. Electron. Mater. Lett. 9(3), 363–366 (2013)T.H. Sajeesh, N. Poornima, C. Sudha Kartha, K.P. Vijayakumar, Unveiling the defect levels in SnS thin films for photovoltaic applications using photoluminescence technique. Phys. Status Solidi Appl. Mater. Sci. 207(8), 1934–1939 (2010)P.A. Nwofe, R.W. Miles, K.T. Ramakrishna Reddy, Effects of sulphur and air annealing on the properties of thermally evaporated SnS layers for application in thin film solar cell devices. J. Renew. Sustain. Energy. 5, 011204 (2013)K.T. Ramakrishna Reddy, N. Koteswara, R.W. Reddy, Miles, Photovoltaic properties of SnS based solar cells. Sol. Energy Mater. Sol. Cells 90(18–19), 3041–3046 (2006)A. Polizzotti et al., Improving the carrier lifetime of tin sulfide via prediction and mitigation of harmful point defects. J. Phys. Chem. Lett. 8(15), 3661–3667 (2017)Y.H. Khattak et al., Effect of CZTSe BSF and minority carrier life time on the effeciency enhancement of CZTS kesterite solar cell. Curr. Appl. Phys. 18(6), 633–641 (2018)A.R. Garcia-Angelmo, R. Romano-Trujillo, J. Campos-Álvarez, O. Gomez-Daza, M.T.S. Nair, P.K. Nair, Thin film solar cell of SnS absorber with cubic crystalline structure. Phys. Status Solidi Appl. Mater. Sci. 212(10), 2332–2340 (2015
Reading James Jackson: Who's the author?:Reading Race, Collecting Cultures - The Roving Reader Files: 'Reading James Jackson'
No full textThe Ahmed Iqbal Ullah Race Relations Resource Centre is an open access University of Manchester facility. The blog 'Reading Race, Collecting Cultures' (www.aiucentre.wordpress.com) features on its website (http://www.racearchive.manchester.ac.uk). The Roving Reader Files category of blog posts is produced by Alison Newby (under the pseudonym The Roving Reader) in collaboration with Hannah Niblett (Collections Access Officer). The former provides the text and the latter provides the images. The Roving Reader Files are designed as public engagement materials. The intention is to introduce research skills and terminology to the general user/reader in an entertaining yet informative manner by revealing hidden stories, making unusual connections and sharing insights into using the Centre's collection for research. The related posts "Reading James Jackson: Who's the author?" and "Reading James Jackson: Footnotes" introduce readers to biography; scholarly editions and the role of the editor; the importance of contextualising sources in their historical period; footnotes and their uses
Numerical Modeling Baseline for high efficiency (Cu2FeSnS4) CFTS based Thin Film Kesterite Solar Cell
No full text[EN] Cu2FeSnS4 (CFTS) is auspicious nontoxic and earth abundant semiconductor compound having kesterite symmetrical structure. It is an attractive and suitable material for the fabrication of low cost, high efficiency and sustainable thin film photovoltaic cell. ¿¿¿¿¿¿¿¿ based kesterite photovoltaic cell device modeling was performed in this work. The influence of device parameters such as the thickness, acceptor and donor carrier concentration densities of absorber and electron transport layer (ETL), effect of back contact metal work function and the temperature effect on the performance of ¿¿¿¿¿¿¿¿ based kesterite photovoltaic cell is analyzed by using one dimensional solar cell capacitance simulator (SCAPS) software. In this work, promising optimized results had been achieved with the conversion efficiency of 19.97%, fill factor (¿¿¿¿) 85.94 %, short-circuit current (¿¿¿¿¿¿ ) 23.37 ¿¿¿¿/¿¿¿ 2 and open circuit voltage (¿¿¿¿¿¿ ) 0.995V. The above results will give imperative baselines and feasible directions for the fabrication of higher efficiency ¿¿¿¿¿¿¿¿ based photovoltaic cellThis work was supported by Ministerio de Economia y Competitividad (ENE2016-77798-C4-2-R) and Generalitat valenciana (Prometeus 2014/044).Khattak, YH.; Baig, F.; Ullah, S.; Marí, B.; Ullah, H. (2018). Numerical Modeling Baseline for high efficiency (Cu2FeSnS4) CFTS based Thin Film Kesterite Solar Cell. Optik - International Journal for Light and Electron Optics. 164:547-555. https://doi.org/10.1016/j.ijleo.2018.03.055S54755516
Enhancement of the conversion efficiency of thin film kesterite solar cell
No full text[EN] Cu2ZnSnS4(CZTS) is a non-toxic earth abundant material and a promising quaternary semiconductor compound of groups I - II - IV - VI having a kesterite symmetrical structure. Due to its optimum direct bandgap, it has been considered as a suitable material for absorber layers for photovoltaic cell applications. This paper presents the numerical simulation and modeling of CZTS based thin film kesterite photovoltaic cells using SCAP-1D software. The influence of device parameters such as the carrier concentration, thickness, densities of absorber, buffer and window layers, defect densities and the temperature effect on the performance of the ZnO/CdS/CZTS/Mo photovoltaic cell structure are analyzed. Defect densities are added to the absorber layer and the interface between the buffer layer and the absorber layer. This type of solar cell does not comprise any toxic material and can lead to non-toxic thin film photovoltaic cells with outstanding optical properties. In this work, promising optimized results had been achieved with a conversion efficiency of 23.72%, a fill factor of 82.54%, a short-circuit current (J(sc)) of 44.87 mA/cm(2), and an open circuit voltage (V-oc) of 0.64V. Published by AIP Publishing.This work was supported by Ministerio de Economia y Competitividad (ENE2016-77798-C4-2-R) and Generalitat valenciana (Prometeus 2014/044).Khattak, YH.; Baig, F.; Ullah, S.; Marí, B.; Ullah, H. (2018). Enhancement of the conversion efficiency of thin film kesterite solar cell. Journal of Renewable and Sustainable Energy. 10(3). https://doi.org/10.1063/1.5023478S10
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