Electrospun Nano-fibrous webs have great potential in application in high efficiency air cleaning systems. In filtration process, the formation of cake on the filter media causes pressure drop that increase the filtration efficiency. Pressure drop of fibrous media is a function of cake characteristics such as porosity and air permeability. In this paper, the cake formation on Nano-fibrous filter media is simulated using an image processing technique. The effects of particles’ characteristics, such as shape, size and configuration on cake porosity are investigated using the newly developed algorithm. Results of simulation show that the larger particles in air stream cause higher cake porosity.

This study presents a novel method for observation of stage position in a 2D Nano-positioning system based on a hybrid Kalman  lter. The proposed method obviates the need to measure the stage position directly using complex and costly capacity sensors. Instead, traditional piezo actuators equipped with strain gauge sensors are utilized to measure the de ection of the magni cation system at the position of actuators. Then, a powerful estimation algorithm called Kalman  lter was employed to observe stage displacements. The designed hybrid Kalman  lter uses dynamical equations of motion in the prediction step. The piezo actuators de ections are measured and exploited to correct the predicted values for the system state variables. In order to simulate realistic conditions, a relatively exact COMSOL model was developed for the Nano-positioner. Here, the noise was added to the piezo displacements obtained by simulating this model, and these noisy data were used as measurements in the Kalman  lter algorithm. The designed hybrid Kalman  lter was examined for three di erent updating time steps. The results showed that the designed Kalman  lter appropriately estimated the stage displacements, and its accuracy was enhanced upon reducing the  lter time step.

Abstract This paper proposed LC-ladder filter based on transconductance (GmC) with 130 nm RF CMOS process technology node at 1. 2 V. Further, a seventh-order low-pass filter prototype and a sixth-order band-pass filter prototype have been invented to prove high-frequency functioning in a way that is relatively suited for s-parameters modelling. The low pass and band pass elements of an LC filter have been successfully implemented with GmC, and high-frequency operation has been achieved with compact passive components. To perform simulations and validate s-parameters in the intended frequency range of 2 GHz to 6 GHz, an RF-simulation platform (ADS from Keysight) has been utilised. The 8-bit capacitor-bank array used in this device allows the wideband adjustable function to be controlled by a digital or analogue signal from the external control. Due to the current mode multi-port GmC operation, an average selectivity with Q in the range of 27 to 39 has been achieved at 4. 3mW, while maintaining low power consumption. By selecting the appropriate Gm and capacitive sizes for the cap-bank, it was feasible to achieve the broad operation required in the existing wireless range (2GHz-6GHz). SPICE and RF (s-parameter, harmonic balancer) simulations in ADS have been used in combination to examine the frequency response and noise performance of the proposed structure. When compared to state-of-the-art-work, the suggested Low power tunable filter stands out because to its improved frequency range, low supply voltage, better value of noise performance, and low power dissipation, which will be useful for complex analogue circuit design.

A critical research area overlooked in previous studies on Nano-silica material is the understanding of how its physical characteristics influence its final behavior as a composite when added to the asphalt binder. This study aimed to understand the feasibility of modifying the Nanosilica with asphalt binder based on the asphalt binder characteristics. 60/70 penetration grade asphalt cement was prepared by adding (2%, 4% and 6%) of Nanosilica by weight of asphalt. Properties of Nanosilica material and asphalt cement were first examined. To prepare the modified asphalt binder was heated at 140C, blended by mechanical mixer at a speed of 2000 rpm for different mixing durations (30 to 60) minute. The modified asphalt binder was examined for rheological properties including penetration grade, softening point temperature, penetration index, Brookfield rotational viscosity and ductility test. Results shows that the modified asphalt binder stiffness increases based on rheological properties and sensitivity of temperature decreases with increasing Nanosilica percentage. A­4 % Nano silica by asphalt weight enhanced the conventional properties of the modified asphalt binder and became proper in hot weather conditions. While ductility of modified asphalt decreases with increasing Nano silica percentage, due to stiffness and agglomeration increased. Finally, longer mixing time to more than 60 min had an adverse effect on the ductility property and lead to agglomeration of Nanosilica modified asphalt binder.

Many studies have been conducted to investigate the removal of various pollutants from water using Nanoparticles. The results indicate that this method has a very high efficiency. In this study, polyurethane filter is modified by Nano sized polypyrrole (PPy) and used to improve the quality of the waste water. The chemical polymerization by in place method was used for polymerization of PPy. The Scanning Electron Microscopy (SEM) and Fourier Transform Infrared Spectroscopy (FT-IR) was used for characterization of morphology, size and porosity of synthesized Nano-polymers. The results indicate that the synthesized polymers are granular and uniformly (≈ 50 to 120 nm) synthesized on the polyurethane filter. Central Composite Design (CCD) was used to study the effect of filtration time and filter height on the improving of waste water quality. The quality of waste water after filtration was checked by spectroscopy and various devices such as BOD meters, salinity gauge and so. The results indicate that designed filter has a good performance in improving the parameters such as total dissolved solids (TDS), biological oxygen demand (BOD), chemical oxygen demand (COD), color, salinity, hardness and pH from waste water. After data modeling, optimal conditions for improving the quality of waste water such as the number of passing waste water samples from filter and filter thickness were obtained using graphical method. The optimum thickness for the filter is 1. 3 centimeters and the most suitable filtration is 8 times.

In this research, we studied isolation of the cellulolitic fungi from the persimmon tree, grapevine, pomegranate tree and walnut soils. Among of them, persimmon soil was selected because of maximum cellulolitic fungi. Seven fungi werw isolated from persimmon soil, which three of them had suitable cellulose activity and they were identificated by 18S rRNA and named: Aspergillus niger MZM 89-a2, Penicillium decumbens ZHE 89-p3, Penicillium decumbens MMH 89-p1. Cellulase activities of these fungi were respectively (U/d): FPA 3.1671, 3.5740, 3.1812 and Avicelase 1.6605, 0.3869, 1.1451 and CMCase 2.950, 0.2644, 0.4604. Response surface activity (RSM) was studied to evaluate the effects of temperature, moisture content and particle size for FPA by Aspergillus niger MZM 89-a2. The optimum FPA was in temperature, moisture content and particle size respectively: 28.49oC, 66.62٪ and 1.5-2 (mm). The maximum predicted FPA was 4.35 (U/g) and obtained FPA under this condition was 4.42 (U/g), which indicates the efficacy of the model for prediction of FPA activity under different conditions of the medium.