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91.
Islam Shafi Ul Latief Urosa Ahmad Iftkhar Khan Zeeshan Ali Javid Khan Mohd. Shahid 《Journal of Materials Science: Materials in Electronics》2022,33(29):23137-23152
Journal of Materials Science: Materials in Electronics - The NiO/ZnO/Fe2O3 ternary nanocomposites with different molar ratios (1:1:1), (2:1:1), (3:1:1) and (4:1:1) were synthesized by... 相似文献
92.
This work presents a triband antenna, which is compact, low profile, and covers the bandwidth requirements for WLAN and WiMAX applications. The proposed design is a modified and miniaturized printed monopole antenna. It consists of beveling rectangular patch, a Pi‐shape slot element, and an inverted‐L slot element to achieve resonance in three bands. The physical size of the antenna is 27.5 × 20 mm2 while the electrical size is 0.26 λ0 × 0.23 λ0 at the lower operating frequency which is very compact as compared to other triband designs. It works in three bands, that is, 2.37 to 2.52 GHz, 3.35 to 3.90 GHz, and 4.97 to 7.85 GHz with |S11| < ? 10 dB within these operating bands. The prototype of the proposed miniaturized antenna has been fabricated and the measured results are provided for validation. Antenna performance is studied in terms of input match, gain, radiation efficiency, surface current distributions, and radiation pattern. The antenna shows a nearly omnidirectional radiation pattern with peak efficiency of 90% and acceptable gain of 4 dBi over the three operating bands of WLAN and WiMAX. The prototype of the antenna is fabricated, and simulated results have been verified through measurements. 相似文献
93.
Stemming is the basic operation in Natural language processing (NLP) to remove derivational and inflectional affixes without performing a morphological analysis. This practice is essential to extract the root or stem. In NLP domains, the stemmer is used to improve the process of information retrieval (IR), text classifications (TC), text mining (TM) and related applications. In particular, Urdu stemmers utilize only uni-gram words from the input text by ignoring bigrams, trigrams, and n-gram words. To improve the process and efficiency of stemming, bigrams and trigram words must be included. Despite this fact, there are a few developed methods for Urdu stemmers in the past studies. Therefore, in this paper, we proposed an improved Urdu stemmer, using hybrid approach divided into multi-step operation, to deal with unigram, bigram, and trigram features as well. To evaluate the proposed Urdu stemming method, we have used two corpora; word corpus and text corpus. Moreover, two different evaluation metrics have been applied to measure the performance of the proposed algorithm. The proposed algorithm achieved an accuracy of 92.97% and compression rate of 55%. These experimental results indicate that the proposed system can be used to increase the effectiveness and efficiency of the Urdu stemmer for better information retrieval and text mining applications. 相似文献
94.
Farokhi Hamed Ghayesh Mergen H. Gholipour Alireza Hussain Shahid 《Microsystem Technologies》2018,24(5):2123-2136
Microsystem Technologies - This paper analyses the coupled resonant motion of three-layered shear-deformable microbeams. On the basis of the modified couple stress theory, while both the rotational... 相似文献
95.
Shahid Iqbal Le Thai Duy Hyunwoo Kang Ranveer Singh Mohit Kumar Jucheol Park Hyungtak Seo 《Advanced functional materials》2021,31(46):2102567
To realize the potential of Mott transition of multiphasic vanadium oxides (VOx) for memory applications, the development of VOx memtransistors on SiO2 wafer is introduced. Through electrical characterizations, the volatile memory behaviors of the VOx memtransistors are observed in both two- and three-terminal measurements. Their capacitive memory and resistive switching mechanisms are strongly related to the mixed VOx/SiO2 interface (called VSiOx). VSiOx supports the Mott transition in VOx at low bias voltages (<0.5 V), leading to the low power consumption of the memtransistor. Moreover, the fast switching time (≈35 ns) and tunable memory retention with the synaptic functions (potentiation and depression) of the memtransistors (by using the gate and drain biases) are demonstrated. Overall, the findings open up major opportunities for constructing ultrafast and femto-joule power-consuming neuromorphic devices. 相似文献
96.
The use of the evolutionary heuristic simulated evolution for the optimization of the multi-dimensional vector bin packing problem, which is encountered in several industrial applications, is described. These applications range from production planning and steel fabrication to assignment of virtual machines (VMs) onto physical hosts at cloud-based data centers. The dimensions of VMs can include demands of CPU, memory, bandwidth, disk space etc. The generalized goodness functions that aid traversing the search space in an intelligent manner are designed to cater to the multidimensional nature of items (VMs). The efficiency of heuristics is tested by considering phase transition in the generation of difficult test cases. The quality of the heuristics is judged by determining how close the solution is to the estimated lower bound. A new implementation of a tighter lower bound is proposed. Experiments show that superior quality results are obtained by employing the proposed strategy. 相似文献
97.
Dehydrogenation of ethane to ethylene via radical pathways enhanced by alkali metal based catalyst in oxysteam condition
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The dehydrogenation of ethane to ethylene in the presence of oxygen and water was conducted using Na2WO4/SiO2 catalyst at high temperatures. At 923 K, the conversion rate without water was proportional to ethane pressure and a half order of oxygen pressure, consistent with a kinetically relevant step where an ethane molecule is activated with dissociated oxygen on the surface. When water was present, the ethane conversion rate was drastically enhanced. An additional term in the rate expression was proportional to a quarter of the oxygen pressure and a half order of the water pressure. This mechanism is consistent with the quasi‐equilibrated OH radical formation with subsequent ethane activation. The attainable yield can be accurately described by taking the water contribution into consideration. At high conversion levels at 1073 K, the C2H4 yield exceeded 60% in a single‐pass conversion. The C2H4 selectivity was almost insensitive to the C2H6 and O2 pressures. © 2016 American Institute of Chemical Engineers AIChE J, 63: 105–110, 2017 相似文献
98.
The thermal conductivity, thermal diffusivity, and heat capacity per unit volume of dunite rocks taken from Chillas near Gilgit,
Pakistan, have been measured simultaneously using the transient plane source technique. The temperature dependence of the
thermal transport properties was studied in the temperature range from 303 K to 483 K. Different relations for the estimation
of the thermal conductivity are applied. A proposed model for the prediction of the thermal conductivity as a function of
temperature is also given. It is observed that the values of the effective thermal conductivity predicted by the proposed
model are in agreement with the experimental thermal conductivity data within 9%. 相似文献
99.
Metal Organic Framework Crystals in Mixed‐Matrix Membranes: Impact of the Filler Morphology on the Gas Separation Performance
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Anahid Sabetghadam Beatriz Seoane Damla Keskin Nicole Duim Tania Rodenas Salman Shahid Sara Sorribas Clément Le Guillouzer Guillaume Clet Carlos Tellez Marco Daturi Joaquin Coronas Freek Kapteijn Jorge Gascon 《Advanced functional materials》2016,26(18):3154-3163
Mixed‐matrix membranes comprising NH2‐MIL‐53(Al) and Matrimid or 6FDA‐DAM have been investigated. The metal organic framework (MOF) loading has been varied between 5 and 20 wt%, while NH2‐MIL‐53(Al) with three different morphologies, nanoparticles, nanorods, and microneedles has been dispersed in Matrimid. The synthesized membranes have been tested in the separation of CO2 from CH4 in an equimolar mixture. At 3 bar and 298 K for 8 wt% MOF loading, incorporation of NH2‐MIL‐53(Al) nanoparticles leads to the largest improvement compared to nanorods and microneedles. The incorporation of the best performing filler, i.e., NH2‐MIL‐53(Al) nanoparticles, into the highly permeable 6FDA‐DAM has a larger effect, and the CO2 permeability increases up to 85% with slightly lower selectivities for 20 wt% MOF loading. Specifically, these membranes have a permeability of 660 Barrer with a CO2/CH4 separation factor of 28, leading to a performance very close to the Robeson limit of 2008. Furthermore, a new non‐destructive technique based on Raman spectroscopy mapping is introduced to assess the homogeneity of the filler dispersion in the polymer matrix. The MOF contribution can be calculated by modeling the spectra. The determined homogeneity of the MOF filler distribution in the polymer is confirmed by focused ion beam scanning electron microscopy analysis. 相似文献
100.
Khurshid Salman Arif Saqib Iqbal Hafiza Mehwish Akbar Qurrat Ul Ain Yousaf Shahid 《Food science and biotechnology》2020,29(2):243-249
Food Science and Biotechnology - Current study was designed to evaluate sensory and textural quality characteristics of chapatti, a commonly consumed flat bread in South-Asia in relation to flour... 相似文献