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201.
Frank Dudek Bashir Al-Hashimi Mansour Moniri 《International Journal of Electronics》2013,100(2):163-175
This paper describes a current-mode elliptic filter structure based on dual-output OTAs and grounded capacitors. The filter is capable of producing both lowpass and highpass notch responses without changing the filter structure. This is achieved using a symmetrical current switching technique based on two switches controlled with a 2-bit digital word. The proposed filter structure forms a basic second-order building block in the design of high-order elliptic filters with tuneable frequency response. To confirm the theoretical analysis, simulated and measured results of fourth-order elliptic lowpass and highpass filters with tuneable bandwidth in the range of 0.65MHz to 1.3MHz are included. Finally, detailed analysis of the OTAs non-ideal parameters on the filter performance is presented and an example is given. 相似文献
202.
Sajad A Loan M. Saqib Akhoon Faisal Bashir Abdulrahman M. Alamoud Shuja A. Abbasi 《International Journal of Electronics》2013,100(1):111-125
In this work, we propose a new structure of a lateral bipolar junction transistor (LAT-BJT) on partial buried oxide (PBOX). The novelty of the proposed LAT-BJT device is the use of PBOX, covering just base and emitter regions only. A two-dimensional (2D) calibrated simulation study of the proposed LAT-BJT device has shown that the proposed LAT-BJT on PBOX’s performance is unique when the PBOX is just covering base and emitter regions. At this length of PBOX, a sharp enhancement in cut-off frequency (fT) (~10 times higher) is achieved in the proposed LAT-BJT on PBOX in comparison to an LAT-BJT on silicon-on-insulator (SOI). The breakdown voltage of the proposed LAT-BJT on PBOX is double than that of the LAT-BJT on SOI device at this PBOX length. A notable enhancement in current gain (β) is observed in the proposed LAT-BJT on PBOX in comparison to the LAT-BJT on bulk device. To check the performance of the proposed LAT-BJT on PBOX at the circuit level, two inverters have been designed and simulated using the mixed-mode simulations of Atlas simulator. It has been observed that the proposed LAT-BJT on PBOX significantly outperforms the conventional LAT-BJT device in switching performance. A notable improvement of 32% in ON delay and 72.9% in OFF delay is obtained in the proposed LAT-BJT on PBOX device in comparison to the conventional LAT-BJT device. 相似文献
203.
In this paper, we prove the existence and uniqueness of solutions for an anti-periodic boundary value problem of nonlinear impulsive differential equations of fractional order α∈(2,3] by applying some well-known fixed point theorems. Some examples are presented to illustrate the main results. 相似文献
204.
Al-Ayed AS Ali MS Al-Lohedan HA Al-Sulaim AM Issa ZA Kabir-ud-Din 《Journal of colloid and interface science》2011,357(2):393-399
Herein we have investigated the hydrolysis of 1H-indol-2,3-dione (isatin, I) and its derivatives of different hydrophobicities, viz. N-dimethylaminomethyl indol-2,3-dione (II), N-morpholinomethyl indol-2,3-dione (III), N-pipridinomethyl indol-2,3-dione (IV), N-heptylaminomethyl indol-2,3-dione (V), N-dodecylaminomethyl indol-2,3-dione (VI), N-hexylanilinomethyl indol-2,3-dione (VII), N-decylanilinomethyl indol-2,3-dione (VIII), and N-hexadecylanilinomethyl indol-2,3-dione (IX), in the presence of an excess amount of sodium hydroxide. All the isatin derivatives were synthesized in the laboratory. The progress of the reactions was studied by exploiting UV-visible spectrophotometry. The observed rate constant, k(w), increases linearly on increasing the hydroxide ion concentration, indicating first-order dependence on [OH(-)]. The effects of surfactants, cationic (cetyltrimethylammonium chloride, CTACl), and anionic (sodium dodecyl sulfate, SDS) were also investigated. The rate of reaction increased on increasing the concentration of CTACl and, after reaching a maximum, it started decreasing. Conversely, anionic micelles of SDS inhibited the rate of hydrolysis of isatin and its derivatives. The results of the effect of CTACl were analyzed using a pseudophase ion-exchange model while the inhibition by SDS was analyzed using a simple Menger-Portnoy model. The effects of added salts, such as NaBr, NaCl, and (CH(3))(4)NBr, were also seen on the isatin hydrolysis. It was found that the addition of salts decreased the rate enhancement efficiency of the CTACl. 相似文献
205.
Liu DJ Credo GM Su X Wu K Lim HC Elibol OH Bashir R Varma M 《Chemical communications (Cambridge, England)》2011,47(29):8310-8312
A new pyrophosphate (PPi) chelator was designed for surface-sensitive electrical detection of biomolecular reactions. This article describes the synthesis of the PPi-selective receptor, its surface immobilization and application to label-free electrical detection on a silicon-based field-effect transistor (FET) sensor. 相似文献
206.
Background
The heterocyclic hydrazones constitute an important class of biologically active drug molecules. The hydrazones have also been used as herbicides, insecticides, nematocides, redenticides, and plant growth regulators as well as plasticizers and stabilizers for polymers. The importance of the phenolic quinolyl hydrazones arises from incorporating the quinoline ring with the phenolic compound; 2,4-dihydroxy benzaldehyde. Quinoline ring has therapeutic and biological activities whereas, phenols have antiseptic and disinfectants activities and are used in the preparation of dyes, bakelite and drugs. The present study is planned to check the effect of the counter anions on the type and geometry of the isolated copper(II)- complexes as well as the ligational behavior of the phenolic hydrazone; 4-[(2-(4,8-dimethylquinolin-2-yl)hydrazono)methyl] benzene-1,3-diol; (H2L). 相似文献207.
Soybean hulls were subjected to thermo-mechanical extrusion pretreatment at various in-barrel moisture contents and screw
speeds. Extrusion degraded the lignocellulosic structure and enhanced enzymatic hydrolysis of soybean hulls, with up to 155%
increase in glucose yield as compared to untreated substrate. Greater glucose yields were observed at higher in-barrel moistures
(45% and 50%) and lower screw speed (280 and 350 rpm). Maximum 74% cellulose to glucose conversion resulted from using a two-enzyme
cocktail consisting of cellulase and β-glucosidase. Conversion increased to 87% when a three-enzyme cocktail having a cell
wall degrading enzyme complex was used for hydrolysis. Fermentation inhibitors, such as furfural, 5-(hydroxymethyl)-2-furaldehyde
(HMF), and acetic acid, were found in the extrusion pretreated soybean hulls and hydrolysate. However, their concentrations
were below the known thresholds for inhibition. Fermentation of hydrolysate by Saccharomyces cerevisiae led to high yields of ethanol, with concentration ranging from 13.04 to 15.44 g/L. 相似文献
208.
Saeed Ahmad Haseeba Sadaf Muhammad Altaf Helen Stoeckli-Evans Seerat-ur-Rehman Sarfaraz Ahmed Bashir 《Crystallography Reports》2013,58(5):692-696
Two mercury(II) complexes containing cyanide and, N,N′-diethylthiourea (detu) and N,N′-dipropylthiourea (dprtu) ligands, [(detu)2Hg(CN)2] (1) and [(dprtu)2Hg(CN)2] (2), respectively, have been prepared and characterized by X-ray crystallography. In the both complexes Hg atom lies on a 2-fold rotation axis, and is coordinated to the sulfur atoms of two thiourea ligands and to two cyanide carbon atoms. Both have a distorted tetrahedral environment with bond angles about the Hg atoms in the range of 93.41(4)°–146.75(19)°. In the crystal structures symmetry related molecules are linked via N-H-N hydrogen bonds resulting in the formation of a two-dimensional network in 1, while in 2 a double stranded one-dimensional chain is formed. 相似文献
209.
Bashir Ahmed Tahir Rashid Ahmed M. G. B. Ashiq Afaq Ahmed M. A. Saeed 《中国物理 B》2012,21(4):44201-044201
This study deals with Nd:YAG laser cutting nonmetallic materials, which is one of the most important and popular industrial applications of laser. The main theme is to evaluate the effects of Nd:YAG laser beam power besides work piece scanning speed. For approximate cutting depth, a theoretical study is conducted in terms of material property and cutting speed. Results show a nonlinear relation between the cutting depth and input energy. There is no significant effect of speed on cutting depth with the speed being larger than 30 mm/s. An extra energy is utilized in the deep cutting. It is inferred that as the laser power increases, cutting depth increases. The experimental outcomes are in good agreement with theoretical results. This analysis will provide a guideline for laser-based industry to select a suitable laser for cutting, scribing, trimming, engraving, and marking nonmetallic materials. 相似文献
210.
Shazia Bashir Nazar Farid Khaliq Mahmood M. Shahid Rafique 《Applied Physics A: Materials Science & Processing》2012,107(1):203-212
The ablation of Cd has been performed by employing Q-switched Nd: YAG 10 ns laser pulses with a central wavelength of 1064 nm
for a pulsed energy of 200 mJ under various ambient environments of argon, air and helium. The optical emission spectroscopy
of Cd plasma has been studied under different filling pressures of shield gases ranging from 5 torr to 760 torr using LIBS
spectrometer system. The effect of different gases and their pressures on the intensity of spectral emission, electron temperature
and density of the laser-produced plasma has been investigated. SEM analysis has been performed to investigate the dependence
of surface morphological changes of an irradiated target on the nature and pressure of an ambient gas. A strong correlation
has revealed the vital role of electron temperature and density of laser-induced plasma for the surface modification of Cd.
These results strongly indicate that the nature and pressure of the ambient atmosphere is one of the controlling factors of
the plasma characteristics, as well as the factors related to the laser energy absorption for surface modification. 相似文献