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1.
The design of many thermal Microelectromechanical (MEMS) actuators is often based on finite element analysis, but lacks analytical
insight. In this paper we report a novel electro-thermal microgripper and a comprehensive thermal modeling of a general 5
lineshape microbeam’s actuator using 1-D steady state heat equations. Because of the variety of microgripper fabrication technologies
and their applications, different thermal boundary conditions are considered for lifted off and attached grippers. Parametric
and nonparametric electrothermomechanical identification models for silicon on insulator microgripper, fabricated on 100 μm
device layer, are obtained. 相似文献
2.
Mayyas K. Aboulnasr T. 《Circuits and Systems II: Express Briefs, IEEE Transactions on》2004,51(3):136-142
This paper proposes a new low-complexity transform-domain (TD) adaptive algorithm for acoustic echo cancellation. The algorithm is based on decomposing the long adaptive filter into smaller subfilters and employing the selective coefficient update (SCU) approach in each subfilter to reduce computational complexity. The resulting algorithm combines the fast converging characteristic of the TD decomposition technique and the benefits of the SCU of low complexity with minimal performance losses. The improvement in convergence speed comes at the expense of a corresponding increase in misadjustment. To overcome this problem, a hybrid of the proposed algorithm and the standard TD LMS algorithm (TDLMS) is presented. The hybrid algorithm retains the fast convergence speed capabilities of the original algorithm while allowing for low final MSE. Simulations show that the hybrid algorithm offers a superior performance when compared to the standard TDLMS algorithm with less computational overhead. 相似文献
3.
Mohannad Qurie Jehad Abbadi Laura Scrano Gennaro Mecca Sabino A. Bufo Mustafa Khamis Rafik Karaman 《International journal of molecular sciences》2013,14(7):13808-13825
The reverse osmosis (RO) brine generated from the Al-Quds University wastewater treatment plant was treated using an epuvalisation system. The advanced integrated wastewater treatment plant included an activated sludge unit, two consecutive ultrafiltration (UF) membrane filters (20 kD and 100 kD cutoffs) followed by an activated carbon filter and a reverse osmosis membrane. The epuvalisation system consisted of salt tolerant plants grown in hydroponic channels under continuous water flowing in a closed loop system, and placed in a greenhouse at Al-Quds University. Sweet basil (Ocimum basilicum) plants were selected, and underwent two consecutive hydroponic flowing stages using different brine-concentrations: an adaptation stage, in which a 1:1 mixture of brine and fresh water was used; followed by a functioning stage, with 100% brine. A control treatment using fresh water was included as well. The experiment started in April and ended in June (2012). At the end of the experiment, analysis of the effluent brine showed a remarkable decrease of electroconductivity (EC), PO43−, chemical oxygen demand (COD) and K+ with a reduction of 60%, 74%, 70%, and 60%, respectively, as compared to the influent. The effluent of the control treatment showed 50%, 63%, 46%, and 90% reduction for the same parameters as compared to the influent. Plant growth parameters (plant height, fresh and dry weight) showed no significant difference between fresh water and brine treatments. Obtained results suggest that the epuvalisation system is a promising technique for inland brine treatment with added benefits. The increasing of channel number or closed loop time is estimated for enhancing the treatment process and increasing the nutrient uptake. Nevertheless, the epuvalisation technique is considered to be simple, efficient and low cost for inland RO brine treatment. 相似文献
4.
Shapsough Salsabeel Takrouri Mohannad Dhaouadi Rached Zualkernan Imran A. 《Wireless Networks》2021,27(6):4313-4329
Wireless Networks - This paper presents a novel IoT-based architecture that utilizes IoT hardware, software, and communication technologies to enable real-time monitoring and management of solar... 相似文献
5.
Yifang Wang Mohannad Mayyas Jiong Yang Jianbo Tang Mohammad B. Ghasemian Jialuo Han Aaron Elbourne Torben Daeneke Richard B. Kaner Kourosh Kalantar-Zadeh 《Advanced functional materials》2021,31(3):2005866
2D transition metal dichalcogenides (TMDs) play increasingly significant roles in research and future optoelectronics. However, the large-scale deposition of 2D TMDs remains challenging due to sparse nucleation and substrate dependency. Liquid metals can offer effective solutions to meet these challenges due to their reactive, non-polarized, and templating properties. Here, self-deposition of 2D molybdenum sulfide is shown by introducing a molybdenum precursor onto the surface of a eutectic alloy of gallium and indium (EGaIn). EGaIn serves as an ultra-smooth template and reducing agent for the precursor to form large-scale planar molybdenum sulfides, which is transferrable to any substrate. The molybdenum sulfides form spontaneously on the surface of EGaIn, which has a sufficient potential to drive the cathodic reactions of the deposition process. A highly crystalline 2H-MoS2 is obtained after a final annealing step. This work demonstrates a fundamentally new capability for the formation of large-scale 2D TMDs. 相似文献
6.
Mohammad B. Ghasemian Mohannad Mayyas Shuhada A. Idrus‐Saidi Muhammad A. Jamal Jiong Yang Sajjad S. Mofarah Esmaeil Adabifiroozjaei Jianbo Tang Nitu Syed Anthony P. O'Mullane Torben Daeneke Kourosh Kalantar‐Zadeh 《Advanced functional materials》2019,29(36)
Liquid metals offer unprecedented chemistry. Here it is shown that they can facilitate self‐limiting oxidation processes on their surfaces, which enables the growth of metal oxides that are atomically thin. This claim is exemplified by creating atomically thin hydrated MnO2 using a Galvanic replacement reaction between permanganate ions and a liquid gallium–indium alloy (EGaIn). The “liquid solution”–“liquid metal” process leads to the reduction of the permanganate ions, resulting in the formation of the oxide monolayer at the interface. It is presented that under mechanical agitation liquid metal droplets are established, and simultaneously, hydrated gallium oxides and manganese oxide sheets delaminate themselves from the interfacial boundaries. The produced nanosheets encapsulate a metallic core, which is found to consist of solid indium only, with the full migration of gallium out of the droplets. This process produces core/shell structures, where the shells are made of stacked atomically thin nanosheets. The obtained core/shell structures are found to be an efficient photocatalyst for the degradation of an organic dye under simulated solar irradiation. This study presents a new research direction toward the modification and functionalization of liquid metals through spontaneous interfacial redox reactions, which has implications for many applications beyond photocatalysis. 相似文献
7.
Khaled Mayyas 《Digital Signal Processing》2013,23(1):75-85
Selective partial update of the adaptive filter coefficients has been a popular method for reducing the computational complexity of least mean-square (LMS)-type adaptive algorithms. These algorithms use a fixed step-size that forces a performance compromise between fast convergence speed and small steady state misadjustment. This paper proposes a variable step-size (VSS) selective partial update LMS algorithm, where the VSS is an approximation of an optimal derived one. The VSS equations are controlled by only one parameter, and do not require any a priori information about the statistics of the system environment. Mean-square performance analysis will be provided for independent and identically distributed (i.i.d.) input signals, and an expression for the algorithm steady state excess mean-square error (MSE) will be presented. Simulation experiments are conducted to compare the proposed algorithm with existing full-update VSS LMS algorithms, which indicate that the proposed algorithm performs as well as these algorithms while requiring less computational complexity. 相似文献
8.
Abdalla Alrashdan Ahmad Turki Mayyas Said Al-Hallaj 《Journal of Materials Processing Technology》2010,210(1):174-179
In this paper, blocks for the thermal management of Li-ion battery are prepared. The blocks are made of paraffin wax, which is used as a phase change material (PCM), and graphite flakes. The process starts by compacting expanded graphite into the desired modular shapes and then impregnating it into molten paraffin wax. The modular pieces were assembled together, followed by finishing operations to achieve a desired packaging geometry.Thermo-mechanical properties of the produced phase change material–expanded graphite (PCM/EG) composites have been studied. The tests include thermal conductivity, tensile compression and bursting test. The results showed that as mass fraction of paraffin wax increases in the composite material, the thermal conductivity, tensile strength, compression strength, and burst strength were improved while tested at low operating temperatures. In contrast, the results showed reverse behaviors when tested at relatively high operating temperature. 相似文献
9.
The influence of the lubricant magnesium stearate (MgSt) on the powder and tablet properties of chitin-Mg silicate coprecipitate was examined and compared with lubricated Avicel® 200 and Avicel-Mg silicate coprecipitate. Crushing strength and disintegration time studies were conducted in order to evaluate tablet properties at different compression pressures. Lubrication of chitin-Mg silicate powder with MgSt was evaluated using a high speed rotary tablet press. The compactability and disintegration time of chitin-Mg silicate are unaffected by the possible deleterious action of up to 2% (w/w) MgSt. The deleterious effect of MgSt on Avicel® 200 compaction was found to be minimized when magnesium silicate was coprecipitated onto Avicel® 200. Lubrication of chitin-Mg silicate with MgSt does not enhance particle agglomeration, whereas the opposite is the case for Avicel® 200; the foregoing was ascertained by measurements of the fixed bulk density, constant powder porosity using Kawakita analysis and by the absence of variation in particle size distribution in the presence of up to 5% (w/w) MgSt. In the case of chitin-Mg silicate tablets the ejection force was greatly reduced at a compression speed of 150,000 tablet/h at a MgSt concentration of 0.5% (w/w). The physical properties and drug dissolution profile of ibuprofen tablets were found to be unaffected when chitin-Mg silicate was lubricated up to 5% (w/w) with MgSt. Optimal drug dissolution was attained for gemfibrozil tablets using 3% (w/w) MgSt when compared to a reference (Lopid tablets). 相似文献
10.
Maricruz G. Saborio Shengxiang Cai Jianbo Tang Mohammad B. Ghasemian Mohannad Mayyas Jialuo Han Michael J. Christoe Shuhua Peng Pramod Koshy Dorna Esrafilzadeh Rouhollah Jalili Chun H. Wang Kourosh Kalantar‐Zadeh 《Small (Weinheim an der Bergstrasse, Germany)》2020,16(12)
Colloidal liquid metal alloys of gallium, with melting points below room temperature, are potential candidates for creating electrically conductive and flexible composites. However, inclusion of liquid metal micro‐ and nanodroplets into soft polymeric matrices requires a harsh auxiliary mechanical pressing to rupture the droplets to establish continuous pathways for high electrical conductivity. However, such a destructive strategy reduces the integrity of the composites. Here, this problem is solved by incorporating small loading of nonfunctionalized graphene flakes into the composites. The flakes introduce cavities that are filled with liquid metal after only relatively mild press‐rolling (<0.1 MPa) to form electrically conductive continuous pathways within the polymeric matrix, while maintaining the integrity and flexibility of the composites. The composites are characterized to show that even very low graphene loadings (≈0.6 wt%) can achieve high electrical conductivity. The electrical conductance remains nearly constant, with changes less than 0.5%, even under a relatively high applied pressure of >30 kPa. The composites are used for forming flexible electrically‐conductive tracks in electronic circuits with a self‐healing property. The demonstrated application of co‐fillers, together with liquid metal droplets, can be used for establishing electrically‐conductive printable‐composite tracks for future large‐area flexible electronics. 相似文献