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Issue Info: 
  • Year: 

    2016
  • Volume: 

    5
Measures: 
  • Views: 

    200
  • Downloads: 

    106
Abstract: 

RESPONSE SURFACE METHODOLOGY (RSM) BASED ON CENTRAL ROTATABLE EXPERIMENTAL DESIGN WAS USED TO INVESTIGATE THE EFFECT OF ULTRASOUND ASSISTED SIMULTANEOUS ADSORPTION PROCESS VARIABLES ON CU: ZNS-NPS-AC FROM AQUEOUS SOLUTION. CU: ZNS-NPS-AC WAS CHARACTERIZED USING FIELD EMISSION SCANNING ELECTRON MICROSCOPY (FE-SEM), ENERGY DISPERSIVE X-RAY SPECTROSCOPY (EDX) AND X-RAY DIFFRACTION (XRD). TO OVERCOME THE SEVERE METHYLENE BLUE (MB) AND BRILLIANT GREEN (BG) DYES SPECTRAL OVERLAPPING, DERIVATIVE SPECTROPHOTOMETRIC METHOD WERE SUCCESSFULLY APPLIED FOR THE SIMULTANEOUS DETERMINATION OF DYES IN THEIR BINARY SOLUTIONS. SIMULTANEOUS DETERMINATION OF THE DYES CAN BE CARRIED OUT USING THE FIRST- ORDER AND SECOND ORDER DERIVATIVE SIGNAL AT 664 AND 663 NM FOR BG AND MB, RESPECTIVELY. THE FACTORS INVESTIGATED WERE PH (2.5-8.5), ADSORBENT MASS (0.006-2033 0.030 G), SONICATION TIME (1-5 MIN) AND INITIAL MB AND BG CONCENTRATION (3-15 MG L-1). FIVE LEVELS, WHICH WERE LOW LEVEL, CENTER POINT, UPPER LEVEL AND TWO AXILLAR POINTS, WERE CONSIDERED FOR EACH OF THE FACTORS. THE DESIRABILITY FUNCTION (DF: 0.9853) ON THE STATISTICA VERSION 10.0 SOFTWARE SHOWED THAT THE OPTIMUM REMOVAL (99.832 AND 99.423% FOR MB AND BG, RESPECTIVELY) WAS OBTAINED AT PH 8.0, ADSORBENT MASS 0.024 G, SONICATION TIME 4 MIN AND 9 MG L-1 INITIAL CONCENTRATION FOR EACH DYE. BESIDES, THE RESULTS SHOW THAT OBTAINED DATA WERE ADEQUATELY FITTED INTO THE SECOND-ORDER POLYNOMIAL MODEL, SINCE THE CALCULATED MODEL F VALUE (172.96 AND 96.35 FOR MB AND BG, RESPECTIVELY) IS HIGHER THAN THE CRITICAL F VALUE. THE VALUES OF COEFFICIENT OF DETERMINATION (0.9968 AND 0.9943 FOR MB AND BG, RESPECTIVELY) AND ADJUSTED COEFFICIENT OF DETERMINATION (0.9911 AND 0.9840 FOR MB AND BG, RESPECTIVELY) ARE CLOSE TO 1, INDICATING A HIGH CORRELATION BETWEEN THE OBSERVED AND THE PREDICTED VALUES. THE ULTRASONIC AMPLITUDE AND ADSORBENT MASS WERE FOUND TO BE THE MOST EFFECTIVE VARIABLE INFLUENCING THE ADSORPTION PROCESS. THE ADSORPTION EQUILIBRIUM WAS WELL DESCRIBED BY THE LANGMUIR ISOTHERM MODEL WITH MAXIMUM ADSORPTION CAPACITY OF 185.2 AND 151.5 MG G-1 FOR MB AND BG RESPECTIVELY ON ADSORBENT. THE RESULTS INDICATE THAT PSEUDO-SECOND-ORDER KINETIC EQUATION AND INTRA-PARTICLE DIFFUSION MODEL CAN BETTER DESCRIBE THE ADSORPTION KINETICS.

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Author(s): 

Zarrabi Mansur

Issue Info: 
  • Year: 

    2024
  • Volume: 

    11
  • Issue: 

    2
  • Pages: 

    91-103
Measures: 
  • Citations: 

    0
  • Views: 

    0
  • Downloads: 

    0
Abstract: 

A highly stable and high-density amino group (6.54 µmol/m2 ) was loaded on super-hydrophobic silica aerogel derived from pumice by the ultrasonic method and used to remove arsenate (As). After ultrasonic amine grafting, the specific surface area did not change, as 832 m2 /g of a specific surface, a hole volume of 3.84 cm3 /g, and an average hole diameter of 12.39 nm were observable. The selected parameters were directly dependent on As adsorption (100% As removal at the pH rate of 6.85, reaction time of 120 minutes, and initial solute concentration of 95.21 µg/L based on multiple non-linear regression analyses). The kinetics of As adsorption was best explained by the pseudo-first-order kinetic, which is proof of the chemical adsorption mechanism. The heterogeneous surface with multilayer adsorption sites for As adsorption was obtained from various isotherm models. The maximum uptake capacity of 42.2 mg/g was observed based on the Khan model. The spent adsorbent was successfully regenerated and reused by HCl, but a substantial reduction in adsorption capacity was detected after five regeneration-reuse cycles. Based on the results, the ultrasonic method was found to be more effective, economical, and environmentally friendly compared to conventional sol-gel methods for the surface amine functionalization of silica aerogel to remove As from the aqueous solution.

Yearly Impact: مرکز اطلاعات علمی Scientific Information Database (SID) - Trusted Source for Research and Academic Resources

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Issue Info: 
  • Year: 

    2008
  • Volume: 

    1
  • Issue: 

    4
  • Pages: 

    69-74
Measures: 
  • Citations: 

    0
  • Views: 

    1938
  • Downloads: 

    0
Abstract: 

Ultrasonic Assisted Drilling (USD) is new technique to drill difficult to machine materials. In this method, tool or workpiece vibrates with amplitude of few microns in addition to conventional drill bite rotation. In this experimental research, the bone was drilled both conventionally and using UAD, then the thrust was measured in two methods at feed rates of 50, 75 and 125 mm/s and 500, 710 and 1000 RPMs. The results show that USD method causes the thrust force decreases considerably in compare whit conventional drilling. The maximum temperature is less in USD at low RPMs.

Yearly Impact: مرکز اطلاعات علمی Scientific Information Database (SID) - Trusted Source for Research and Academic Resources

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Issue Info: 
  • Year: 

    2014
  • Volume: 

    17
Measures: 
  • Views: 

    150
  • Downloads: 

    87
Keywords: 
Abstract: 

INTRODUCTION: DYE AS MAIN SOURCES OF ESTHETIC POLLUTION AND EUTROPHICATION ENLARGLY EFFECT THE VARIOUS LIVING THINGS MEDIA: SYNTHETIC DYES REPRESENT A RELATIVELY LARGE GROUP OF ORGANIC CHEMICALS THAT ARE DISCARDED BY VARIOUS INDUSTRIES LIKE; TEXTILE, FOOD, PULP AND PAPER TO THEIR EFFLUENTS. …

Yearly Impact:   مرکز اطلاعات علمی Scientific Information Database (SID) - Trusted Source for Research and Academic Resources

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Author(s): 

Sajjady S.A. | AMINI S.

Issue Info: 
  • Year: 

    2019
  • Volume: 

    19
  • Issue: 

    8
  • Pages: 

    1845-1854
Measures: 
  • Citations: 

    0
  • Views: 

    809
  • Downloads: 

    0
Abstract: 

Since the invention of ultrasonic vibration assisted turning, this process has been widely considered and investigated. The reason for this consideration is the unique features of this process, which include reducing machining forces, reducing wear, and friction, increasing the tool life, creating periodic cutting conditions, increasing the machinability of difficult-to-cut material, increasing the surface quality, creating a hierarchical structure (micro-nano textures) on the surface and so on. Different methods have hitherto been used to apply ultrasonic vibration to the tip of the tool during the turning process. In this research, a unique horn has been designed and constructed to convert linear vibrations of piezoelectrics to threedimensional vibrations (longitudinal vibrations along the z axis, bending vibrations around the x axis, and bending vibrations around the y axis). The advantage of this ultrasonic machining tool compared with other similar tools is that in most other tools, it is only possible to apply one-dimensional (linear) and two-dimensional (elliptical) vibrations, while this tool can create three-dimensional vibrations. Additionally, since the nature of the designed horn can lead to the creation of three-dimensional vibrations, there is no need for piezoelectric half-rings (which are stimulated by 180 phase difference) to create bending vibrations around the x and y axes. The reduction of costs as well as simplicity of applying three-dimensional vibrations in this new method can play an important role in industrializing the process of three-dimensional ultrasonic vibration assisted turning.

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Issue Info: 
  • Year: 

    2019
  • Volume: 

    9
  • Issue: 

    2
  • Pages: 

    287-300
Measures: 
  • Citations: 

    0
  • Views: 

    145
  • Downloads: 

    71
Abstract: 

According to the increasing development of the mankind, social and technology activities in the earth, various industry is in a state of uncontrolled growth. In the present study, magnetite/nickel oxide mixed metal oxide nanoparticles (FNMMO NPs) were prepared by a simple method assisted by ultrasonic waves and applied as a novel adsorbent to dispose of dye wastewater. The morphology and chemical structures of the Fe3O4, NiO and FNMMO NPs were characterization by Fourier transform infrared (FT-IR), X-ray diffraction (XRD), vibrating sample magnetometer (VSM), energy-dispersive X-ray spectroscopy (EDX), scanning electronic microscope (SEM) and transmission electron microscope (TEM). The adsorption of methylene blue (MB) onto FNMMO NPs was studied in relation to initial concentration of MB, contact time, adsorbent dose and pH value of solution. The equilibrium adsorption isotherm was fitted by Langmuir isotherm. The capacity of adsorption was evaluated 40. 1 mg. g-1 and the time required to reach the adsorption equilibrium was 180 min.

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Issue Info: 
  • Year: 

    2017
  • Volume: 

    10
  • Issue: 

    1
  • Pages: 

    13-22
Measures: 
  • Citations: 

    0
  • Views: 

    499
  • Downloads: 

    290
Abstract: 

Equal channel angular extrusion (ECAE) is one of the most powerful processes for manufacturing microstructure and nanostructure materials. This process is a kind of severe plastic deformation technique, which requires large extrusion force. In this study, the numerical and experimental investigation of extrusion force in ultrasonic assisted equal channel angular extrusion process (UAECAE) is carried out. ABAQUS Software is used for 2D finite element analysis of the process considering superimposed ultrasonic vibrations to the round billet work material. Experimentally, the conventional and ultrasonic assisted ECAE are performed with copper material to validate simulation results. The reduction in extrusion forceis observed due to ultrasonic vibrations. In order to achieve more average force reduction, it is recommended that the extrusion speed decreases and (or) vibrations amplitude increases. Stress and strain distributions are numerically investigated in various vibrational conditions and die angles. The best die angle to obtain optimum force reduction is 120º. In other die angles, vibrations amplitudes of 15μmand higher is necessary. Ultrasonic vibrations lead to oscillatory stresses with reduced average value, but do not influence the amount of plastic strain distribution. Achieving the beneficial products in ECAE requires heavy special equipment, whereas using UAECAE will leadto more accessible equipment. Finally, some optimal process parameters such as die angle, vibrations amplitude, for the proper application of these vibrations are proposed.

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Author(s): 

Keymanesh m. | RAZAVI H.

Issue Info: 
  • Year: 

    2019
  • Volume: 

    15
  • Issue: 

    2 (56)
  • Pages: 

    119-129
Measures: 
  • Citations: 

    0
  • Views: 

    689
  • Downloads: 

    0
Abstract: 

Ultrasonic assisted surface rolling (UASR) process is one of the most prominent methods to create severe plastic deformation and fine-grained structures. The aim of this paper is to study the ultrasonic vibration effects in surface rolling process, experimentally. In this regard, the desired horn was designed and manufactured in order to vibrate at longitudinal mode, which the proposed horn is able to change the mechanical properties of the metal surface by applying static pressure and dynamic impacts. Experimental tests were performed for three samples: CK15, CK45 and CK60 (Low, medium and high carbon) with and without applying ultrasonic vibrations. Micro surface hardness tests of samples were compared before and after UASR. The results showed that the higher static pressure leads to the higher micro surface hardness of samples. In addition, the use of ultrasonic vibrations in UASR can cause considerable rise in micro surface hardness. Based on the experimental results, it was found that, applying ultrasonic vibrations in surface rolling process are more effectiveness specifically in high carbon samples. Fatigue life investigation in various amplitudes showed the relative fatigue life improved in UASR process, especially in high vibrations amplitudes.

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Issue Info: 
  • Year: 

    2020
  • Volume: 

    13
  • Issue: 

    3
  • Pages: 

    1-8
Measures: 
  • Citations: 

    0
  • Views: 

    151
  • Downloads: 

    169
Abstract: 

Indentation forming is an internal tube forming process in which a mandrel with a diameter slightly larger than that of the tube is pressed inside the tube and in so doing, creates the internal profile. Forming forces have a significant effect on the spring back, residual stress, quality of the inner surface, quality of tube dimensions, and tool wear. In this study, the forming process of CK45 steel tube by carbide tungsten tool in the presence of ultrasonic vibration has been simulated and the effect of ultrasonic on the forming mechanism has been investigated by introducing two regimes according to the forming conditions. The effects of tool feed-speed and amplitude of vibration on forming force reduction have been investigated. According to the simulation results, the main reason for the force reduction in the presence of longitudinal tube ultrasonic vibration is the intermittent phenomenon which is the continuous or impulsive regime. The critical amplitude which determines the borderline of continuous and impulsive regimes is obtained 38μ m by the simulation of the process. The maximum force reduction obtained in continuous regime is 64. 2% at the critical amplitude. The simulation results are consistent well with the previous experimental data.

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Issue Info: 
  • Year: 

    2022
  • Volume: 

    6
  • Issue: 

    4
  • Pages: 

    69-82
Measures: 
  • Citations: 

    0
  • Views: 

    29
  • Downloads: 

    0
Abstract: 

Research topic: One of the new methods in the process of increasing oil recovery from hydrocarbon reservoirs is the method of using ultrasonic waves. In this research, using ultrasonic waves and their application in a large-scale sample tank, their effect on increasing oil extraction by the numerical method is investigated. Research Method: The modeling process has been performed using MATLAB software in this research. First, by determining the porous environment, the amount of pressure increases due to ultrasonic waves due to solving the sound equations (Helmholtz) by MATLAB k-waves toolbox is investigated. Finally, considering the cumulative production at a specific time from the production well and determining the oil recovery from the reservoir in the presence of a wave, to examine the effect of well location parameters and its distance from the wave generation source, wave production starts time, wave application methods (Pulsed and continuous), is performed at an optimal frequency and power. Main results: According to the modeling results, the closer the wave start time is to the first days of production, the higher the oil recovery rate, So that by starting the application of ultrasonic wave under the power of 5 kW and frequency of 20 kHz simultaneously with the production of well oil from the first day, oil recovery compared to oil recovery in the case of starting the wave from the fifty and ninety days, respectively 4/5% and 8% more. Oil recovery is 1. 8% higher if the wave is applied continuously to the reservoir at a given time than when pulsed at the same time. The modeling results show that the shorter the distance between the wave source and the production well, the lower the pressure drop in the reservoir area and the higher the oil recovery. According to the results, if the source of wave production is located at a distance of 200 feet from the production well, it will increase by 7. 1% compared to the distance of 1800 feet from the oil recovery well.

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