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81.
Anum Kayani Muhammad Asim Raza Arsalan Raza Tajamal Hussain Muhammad Sarfraz Akram Aneela Sabir Atif Islam Bilal Haider Rafi Ullah Khan Sang Hyun Park 《International journal of molecular sciences》2021,22(5)
Chitosan and polyethylene glycol (PEG-600) membranes were synthesized and crosslinked with 3-aminopropyltriethoxysilane (APTES). The main purpose of this research work is to synthesize RO membranes which can be used to provide desalinated water for drinking, industrial and agricultural purposes. Hydrogen bonding between chitosan and PEG was confirmed by displacement of the hydroxyl absorption peak at 3237 cm−1 in pure chitosan to lower values in crosslinked membranes by using FTIR. Dynamic mechanical analysis revealed that PEG lowers Tg of the modified membranes vs. pure chitosan from 128.5 °C in control to 120 °C in CS-PEG5. SEM results highlighted porous and anisotropic structure of crosslinked membranes. As the amount of PEG was increased, hydrophilicity of membranes was increased and water absorption increased up to a maximum of 67.34%. Permeation data showed that flux and salt rejection value of the modified membranes was increased up to a maximum of 80% and 40.4%, respectively. Modified films have antibacterial properties against Escherichia coli as compared to control membranes. 相似文献
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S.S.Batool Z.Imran M.Israr Qadir M.Usman H.Jamil M.A Rafiq M.M.Hassan M.Willander 《材料科学技术学报》2013,29(5):411-414
The effect of metal(Ti,Ni,and Au) electrodes on humidity sensing properties of electrospun TiO2 nanofibers was investigated in this work.The devices were fabricated by evaporating metal contacts on SiO2 layer thermally grown on silicon substrate.The separation between the electrodes was 90μm for all sensors.The sensors were tested from 40%to 90%relative humidity(RH) by AC electrical characterization at room temperature. When sensors are switched between 40%and 90%RH,the corresponding response and recovery time are 3 s and 5 s for Ti-electrode sensor,4 s and 7 s for Ni-electrode sensor,and 7 s and 13 s for Au-electrode sensor.The hysteresis was 3%,5%and 15%for Ti-,Ni-,and Au-electrode sensor,respectively.The sensitivity of Ti,Ni,and Au-electrode sensors are 7.53 MΩ/%RH,5.29 MΩ/%RH and 4.01 MΩ/%RH respectively at 100 Hz.Therefore Ti-electrode sensor is found to have linear response,fast response and recovery time and higher sensitivity as compared with those of Ni- and Au-electrode sensors.Comparison of humidity sensing properties of sensors with different electrode material may propose a compelling route for designing and optimizing humidity sensors. 相似文献
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Shaik Abdul Subhani Karsh Ram Kumar Islam Mohiul Laskar Rabul Hussain 《Multimedia Tools and Applications》2022,81(2):2489-2516
Multimedia Tools and Applications - In the recent digitization era, image hashing is a key technology, including image recognition, authentication and manipulation detection, among many multimedia... 相似文献
84.
Noor-Ul-Ain Babar Yasir Faheem Joya Hassan Khalil Fayyaz Hussain Khurram Saleem Joya 《International Journal of Hydrogen Energy》2021,46(11):7885-7902
Developing only Fe derived bifunctional overall water splitting electrocatalyst both for oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) while performing at low onset overpotential and with high catalytic stability is a rare instance. We present here the first demonstration of unique iron-oxide nanobeads (FeOx-NBs) based electrocatalyst executing both OER and HER with high activity. Thin-film electrocatalytic FeOx-NBs assembly is surface grown via simple spray coating (SC). The unique SC/FeOx-NBs propels OER initiating water oxidation just at 1.49 VRHE (η = 260 mV) that is the lowest observable onset potential for OER on simple Fe-oxide based catalytic films reported so far. Catalyst also reveals decently high HER activity and competent overall water splitting performance in the FeOx-NBs two-electrode system as well. Catalyst also presents stable kinetics, with promising high electrochemically active surface area (ECSA) of 1765 cm2, notable Tafel slopes of just 54 mV dec1? (OER) and 85 mV dec1? (HER), high exchange current density of 1.10 mA cm2? (OER), 0.58 mA cm2? (HER) and TOF of 74.29s1?@1.58VRHE, 262s1?@1.62VRHE (OER) and 82.5s1?@-0.45VRHE, 681s1?@-0.56VRHE (HER). 相似文献
85.
Ziauddin Sobia Asghar Ibrar Hussain Rahmat Ullah Muqaddar Abbas 《Journal of Modern Optics》2020,67(8):737-745
ABSTRACTWe present a theoretical model to realize the symmetric and asymmetric diffraction grating in a four-level atomic medium. The proposed atomic medium follows a double lambda configuration where four fields interact with it. We get control over symmetric and asymmetric behavior of the diffraction grating by manipulating the relative phase of the fields. Interestingly, the symmetric and asymmetric diffraction grating become prominent when the vortex beam is used instead of the plane wave. Enhanced first, second, and third-order diffraction gratings are achieved via the vortex beam. Further, we find control over asymmetric diffraction gratings by the relative phase of the fields. Coherent control of asymmetric diffraction grating in negative and positive diffracted angles is also achieved via the relative phase. 相似文献
86.
Salman Majeed Muhammad Zafar Mushtaq Ahmad Omer Kilic Shazia Sultana Jamil Raza Ghulam Yaseen Hina Gul Sehrosh Mir Lubna Munazza Jabeen 《Microscopy research and technique》2020,83(7):767-777
The family Cactaceae is the diversified group of angiosperm plants whose pollen statistics has been used for taxonomic identification. In this article, we present the pollen morphology of eight species belong to seven taxonomically complex genera of Cactaceae including Astrophytum, Cylindropuntia, Echinocereus, Echinopsis, Mammillaria, Opuntia, and Thelocactus using light and scanning electron microscopy. The pollen grains were acetolyzed, measured, described, and electron photomicrographs were taken. Cactaceae can be characterized by presenting different palynomorphological features including pollen type, sculpturing, polar and equatorial diameter, aperture orientation, exine thickness, P/E ratio, and echini features. Four types of pollen shapes, that is, prolate spheroidal (three species), subprolate (two species), prolate (two species), and oblate spheroidal in Echinocereus reichenbachii were observed. The polar and equatorial diameter observed maximum in O. ficus indica 116.95 and 112.27 μm while minimum in M. compressa 38.42 and 21.05 μm. Pollen of two types, tricolpate in members of subfamily Cactioideae and pantoporate in the Opuntioideae were examined. The fertility percentage has been observed maximum in Opuntia macrocentra (83.84%) and minimum in Opuntia ficus‐indica (57.89%). Exine sculpturing showing great variations such as granulate, reticulate, granulate perforate and micro‐echinate foveolate ornamentation was examined only in Echinopsis eyriesii. A key to species, based on pollen micromorphological attributes, has been constructed for correct identification of complex cactus species. 相似文献
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