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The Culture of Islamic Architecture and Urbanism

$Research paper thumbnail of Evaluation of the accuracy of the cubic law for flow through fractures using Lattice Boltzmann method$

International Journal on Smart Sensing and Intelligent Systems

A novel ultrasonic dispersion system for the dispersing of particles which are mixed in liquid ha... more A novel ultrasonic dispersion system for the dispersing of particles which are mixed in liquid has been proposed in this paper. The frequency of produced ultrasonic wave varies from 30 kHz to 60 kHz with 100 Hz steps. It means that the operating frequency band of designed system is 30 kHz. The maximum and optimum energy of ultrasonic wave can be transfer inside the liquid container with the high efficiency in majority of operating time by the use of some facilities which are implemented in our novel system, so it causes one of the superiority of manufactured system in compare with the other similar systems which are available in

Canadian Institute of Food Science and Technology Journal

Botulinum Neurotoxins (BoNTs) are a large protein family that includes the most potent neurotoxin... more Botulinum Neurotoxins (BoNTs) are a large protein family that includes the most potent neurotoxins known to humankind. BoNTs delivered locally in humans at low doses are widely used pharmaceuticals. Reliable and quantitative detection of BoNTs is of paramount importance for the clinical diagnosis of botulism, basic research, drug development, potency determination, and detection in clinical, environmental, and food samples. Ideally, a definitive assay for BoNT should reflect the activity of each of the four steps in nerve intoxication. The in vivo mouse bioassay (MBA) is the 'gold standard' for the detection of BoNTs. The MBA is sensitive, robust, semi-quantitative, and reliable within its sensitivity limits. Potential drawbacks with the MBA include assay-to-assay potency variations, especially between laboratories, and false positives or negatives. These limitations can be largely avoided by careful planning and performance. Another detection method that has gained importance in recent years for research and potency determination of pharmaceutical BoNTs is cell-based assays, as these assays can be highly sensitive, quantitative, human-specific, and detect fully functional holotoxins at physiologically relevant concentrations. A myriad of other in vitro BoNT detection methods exist. This review focuses on critical factors and assay limitations of the mouse bioassay and cell-based assays for BoNT detection.

Ultrasonic wave can be widely used in different steps of nonomaterial synthesizing processes. The... more Ultrasonic wave can be widely used in different steps of nonomaterial synthesizing processes. The most obvious is dispersing of materials in liquids in order to break particle agglomerates. Known types of systems which are used to this purpose, composed of a liquid tank and a high power ultrasonic generator. In this paper, an ultrasonic dispersion system has been proposed and designed with new method of particle dispersing strategy. The main advantage of the proposed is decreasing dispersion time and increasing the particles size uniformity. It assumed that the mix of particles and liquid medium is passing through a cubical pipe. Suitable number of transducers embedded on one side of the pipe with optimum distance from each other, so that the ultrasonic intensity can be focused on some cavitations zones to stimulate dispersion function gradually. Evaluating of the optimum placement of transducers is calculated and simulated using FEMLAB package (COMSOL multi-physics 3.4). The ultras...

Circuits, Systems, and Signal Processing, 2015

ABSTRACT Sampling switches have a dominant role in switched-capacitor circuits and analog-to-digi... more ABSTRACT Sampling switches have a dominant role in switched-capacitor circuits and analog-to-digital convertors. Since they act as input gates, their nonlinearities directly degrade the quality of the input signals. The scaling-down trend of CMOS technology and increasing demands for high-speed and power-efficient circuits pose design challenge in high-speed sampling switches for low-voltage applications. To address this issue, an optimized CMOS switch is proposed in this paper consisting of a bootstrappedNMOSswitch and a boosted PMOSswitch as a transmission gate.By utilizing this technique, the nonlinearity resulting from the threshold voltage variation (body effect) of NMOS switch is mitigated, considerably. To evaluate the proposed switch, it is designed in 0.18 μm CMOS process technology. According to the obtained simulation results, this switch can achieve total harmonic distortion of−78.81 and−62.99dB in 100 MS/s at Vdd = 1 Volt and 50 MS/s at Vdd = 0.8 V, respectively.

The application of ultrasonic tomography systems for producing cross-sectional images of objects ... more The application of ultrasonic tomography systems for producing cross-sectional images of objects by a noninvasive method plays a dominant role in industry, especially in the oil industry. Since finding the appropriate ultrasonic sensor is the main step in designing an ultrasonic tomography system, determination of the properties of the ultrasonic sensor is very important. In this paper, the manner of ultrasonic wave propagation in various regions and its dependence on frequency are investigated. A finite element software (COMSOL Multiphysics 3.5) is used for visualizing the practical module in a virtual environment to describe the physical interaction inside a metal pipe. Since the transmission mode of an ultrasonic wave is significant in accordance with the data being carried, a frequency should be chosen in which the straight path wave is improved and other propagation modes such as a surface wave on the wall of a metal pipe are attenuated. A frequency of 40 kHz is extracted as the resonance frequency of a desired ultrasonic sensor owing to the simulation results. This claim is proved by the practical testing that is presented in this paper.

2011 IEEE 7th International Colloquium on Signal Processing and its Applications, 2011

Design and Manufacture an Ultrasonic Dispersion System with Automatic Frequency Adjusting Propert... more Design and Manufacture an Ultrasonic Dispersion System with Automatic Frequency Adjusting Property. Herlina Abdul Rahim, Javad Abbaszadeh Bargoshadi, Sahar Sarrafi, Ruzairi Abdul Rahim Sensors & Transducers 126 ...

Sensor Review, 2014

Purpose – Since the importance role of ultrasonic tomography (UT) in industry, especially in oil ... more Purpose – Since the importance role of ultrasonic tomography (UT) in industry, especially in oil industry, to produce noninvasive and nondestructive plane images, research on UT system with a metal pipe conveyor is investigated. The produced cross-sectional images are used for detecting the concentration of solid and liquid mixture inside the pipe, noninvasively. In practice, due to application of metal pipes as the conveyor of oil mixture so the capability of manufacturing an UT system with a metal pipe is investigated in this paper. The paper aims to discuss these issues. Design/methodology/approach – Finite element software (COMSOL Multiphysics 3.5) for visualizing the structure of pipe with mounted sensors on the periphery of the pipe is used. The manner of ultrasonic wave propagation on different layers on various frequencies and finding the time of flight for transmission mode signal and lamb mode signal are achieved by the means of done simulations. Finding the proper ultraso...

Microelectronics Journal, 2014

ABSTRACT Decreasing the size of DAC capacitors is a solution to achieve high-speed and low-power ... more ABSTRACT Decreasing the size of DAC capacitors is a solution to achieve high-speed and low-power successive-approximation register analog-to-digital converters (SAR ADCs). But decreasing the size of capacitors directly effects the linearity performance of converter. In this paper, the effect of capacitor mismatch on linearity performance of charge redistribution SAR ADCs is studied. According to the achieved results from this investigation, a new tri-level switching algorithm is proposed to reduce the matching requirement for capacitors in SAR ADCs. The integral non-linearity (INL) and the differential non-linearity (DNL) of the proposed scheme are reduced by factor of two over the conventional SAR ADC which is the lowest compared to the previous schemes. In addition, the switching energy of the proposed scheme is reduced by 98.02% as compared with the conventional architecture which is the most energy-efficient algorithms in comparison with the previous algorithms, too. To evaluate the proposed method an 8-bit 50 MS/s SAR ADC is designed in 0.18 um CMOS process technology. According to the obtained simulation results, the designed ADC digitizes a 25-MHz input with 48.16 dB SNDR while consuming about 589 μW from a 1.2-V supply.

Journal of Circuits, Systems and Computers, 2014

This paper presents an analog-to-digital converter (ADC), using pipelined successive approximatio... more This paper presents an analog-to-digital converter (ADC), using pipelined successive approximation register (SAR) architecture. The structure which is a combination of SAR-ADC and pipelined ADC benefits from each of their advantages. A new synchronization method is proposed to improve the pipelined SAR-ADC's speed. The proposed method reduces the total conversion without limiting the ADC performance. To evaluate the proposed method a 10-bit 100 MS/s is designed in 0.5 μm CMOS process technology. According to the obtained simulation results, the designed ADC digitizes a 9-MHz input with 54.19 dB SNDR while consuming 57.3 mw from a 5-V supply.

Applied Mechanics and Materials, 2013

Ultrasonic Tomography has a dominant role in industry to generate cross sectional images of any o... more Ultrasonic Tomography has a dominant role in industry to generate cross sectional images of any object. In this paper, method of designing an Ultrasonic Tomography System due to the propagation manner of ultrasonic wave inside the various materials is investigated. The correct method of mounting of Ultrasonic sensors and behavior of the ultrasonic wave propagation in different layers has been simulated by the use of finite element software (COMSOL Multiphysics 3.5). To increase in practical nondestructive evaluation and inspection, we should increase our understanding of the basic physics and wave mechanics associated with guided wave inspection. A suitable ultrasonic sensor base on its efficiency and satisfying the simulation criteria is found and practically implemented on the surface of metal pipe. it is done by estimating the resonance frequency of sensor due to manner of ultrasonic wave propagation in different frequencies shown in simulation results. The proposed optimum frequ...