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Ultrasonics Sonochemistry

Balarabe B Ismail, Mingming Guo, Yunfeng Pu, Wenjun Wang, Xingqian Ye, Donghong Liu
In this study, ultrasound-assisted extraction (UAE) of phenolic compounds in baobab (Adansonia digitata) seeds was optimised using RSM. Based on the single factor experiment results, the effect of four parameters, extraction time (10-20 min), temperature (40-60 °C), % amplitude (30-50) and solvent to solid ratio (20-30, mL/g) on Total Flavonoids Content (TFC) were investigated and optimised using a central composite design (CCD). The predicted optimal conditions with the highest desirably (0.874) were: 20 min, 30% amplitude, 60 °C temperature and 30 mL/g solvent to solid ratio...
November 26, 2018: Ultrasonics Sonochemistry
Yang Tao, Hongbin Han, Wangxin Liu, Lu Peng, Yue Wang, Shekhar Kadam, Pau Loke Show, Xiaosong Ye
In this work, sonication (20-kHz) was conducted to assist the biosorption of phenolics from blueberry pomace extracts by brewery waste yeast biomass. The adsorption capacity of yeast increased markedly under ultrasonic fields. After sonication at 394.2 W/L and 40 °C for 120 min, the adsorption capacity was increased by 62.7% compared with that under reciprocating shaking. An artificial neural network was used to model and visualize the effects of different parameters on yeast biosorption capacity. Both biosorption time and acoustic energy density had positive influences on yeast biosorption capacity, whereas no clear influence of temperature on biosorption process was observed...
November 24, 2018: Ultrasonics Sonochemistry
Rajashree H Jawale, Parag R Gogate
Significant development in the industrial technologies and applications based on the use of cyanide derivatives has also led to significant environmental problems critically needing research in developing new technologies for effluent treatment. Present study investigates the use of novel treatment approach of hydrodynamic cavitation (HC) combined with chemical oxidation and catalyst for the degradation of Potassium Thiocyante (KSCN) for the first time. The effect of operating pressure (over the range of 2-5 bar) and initial pH (over the range of 2-7...
November 22, 2018: Ultrasonics Sonochemistry
Vijay Bhooshan Kumar, Raj Kumar, Aharon Gedanken, Orit Shefi
There is a growing need for biocompatible nanocomposites that may efficiently interact with biological tissues through multiple modalities. Carbon dots (CDs) could serve as biocompatible fluorescence nanomaterials for targeted tissue/cell imaging. Important goals toward this end are to enhance the fluorescence quantum yields of the CDs and to increase their targetability to cells. Here, sonochemistry was used to develop a one-pot synthesis of CDs, including metal-doped CDs (M@CDs), demonstrating how various experimental parameters, such as sonication time, temperature, and power of sonication affect the size of the CDs (2-10 nm) and their fluorescence properties...
November 22, 2018: Ultrasonics Sonochemistry
Alberto Claudio Miano, Meliza Lindsay Rojas, Pedro Esteves Duarte Augusto
This work aimed to demonstrate the internal and external structural changes in potato cylinders caused by different times of ultrasound pretreatment. In addition, the structural changes were associated with the viscoelasticity and mass transfer. For which, potato cylinders were immersed in distilled water and pretreated with and without ultrasound (ultrasonic bath of 91 W/L and 25 kHz) up to 120 min. Then, the microstructure was evaluated by stereoscopic observation as a direct method, and by viscoelasticity and mass transfer evaluation (pigment diffusion and drying) as indirect methods...
November 15, 2018: Ultrasonics Sonochemistry
S Behnia, M Yahyavi, R Habibpourbisafar, F Mottaghi
Ultrasound contrast agents have been recently utilized in therapeutical implementations for targeted delivery of pharmaceutical substances. Radial pulsations of a cluster of encapsulated microbubbles under the action of an ultrasound field are complex and highly nonlinear, particularly for drug and gene delivery applications with high acoustic pressure amplitudes. In this paper, based on Qin-Ferrara's model (Qin and Ferrara, 2010), the complete synchronization and cluster formation in targeted microbubbles network are studied...
November 13, 2018: Ultrasonics Sonochemistry
Yacine Cherifi, Ahmed Addad, Hervé Vezin, Alexandre Barras, Baghdad Ouddane, Ahcène Chaouchi, Sabine Szunerits, Rabah Boukherroub
This study addresses the influence of ultrasound irradiation on the activation of peroxymonosulfate (PMS) using reduced graphene oxide (rGO) under metal-free conditions for the catalytic degradation of rhodamine B (RhB), bisphenol A (BPA) and tetracycline (TC). Our results revealed that the combination of PMS/rGO and ultrasonication enhanced significantly the degradation rate, reaching full degradation in relatively short times with total organic carbon (TOC) removal exceeding 85% of the investigated pollutants...
November 13, 2018: Ultrasonics Sonochemistry
Seyed Mohammad Mohsen Modarres-Gheisari, Roghayeh Gavagsaz-Ghoachani, Massoud Malaki, Pedram Safarpour, Majid Zandi
The emulsions with nano-sized dispersed phase is called nanoemulsions having a wide variety of applications ranging from food, dairy, pharmaceutics to paint and oil industries. As one of the high energy consumer methods, ultrasonic emulsification (UE) are being utilized in many processes providing unique benefits and advantages. In the present review, ultrasonic nano-emulsification is critically reviewed and assessed by focusing on the main parameters such pre-emulsion processes, multi-frequency or multi-step irradiations and also surfactant-free parameters...
November 9, 2018: Ultrasonics Sonochemistry
Lei Qiao, Yuping Wu, Sheng Hong, Jie Cheng
A Fe-based amorphous/nanocrystalline coating was prepared on the AISI 321 steel by the high-velocity oxygen-fuel (HVOF) thermal spraying technology in this paper. Cavitation erosion behavior and mechanism of the coating was studied through the analysis of curves for cavitation erosion resistance versus time and the observation of eroded particles, with the AISI 321 steel as a reference. It was found that the Fe-based coating had better cavitation erosion resistance than the AISI 321 steel, and exhibited obvious periodic failure behavior in the cavitation erosion process...
November 9, 2018: Ultrasonics Sonochemistry
Saki Fukunaga, Sayaka Higashi, Takafumi Horie, Hiroaki Sugiyama, Akihisa Kanda, Tong-Yang Hsu, Kuo-Lun Tung, Keita Taniya, Satoru Nishiyama, Naoto Ohmura
This study investigated the position of ultrasonic irradiation source and reactor geometry on fragmentation rate of a layered compound, α-zirconium phosphate (α-ZrP). By numerically solving the acoustic pressure distribution using COMSOL Multiphysics®, it is clarified the mechanism whereby the operating factors influenced the α-ZrP dispersion to make a suggestion of guideline of the process design method. Two vessels made of glass with a flat-bottom and a spherical-bottom, respectively, were used. Although the flat-bottom vessel at lower horn position showed the best performance of fragmentation, the region of high acoustic pressure field in the flat bottom vessel sharply narrowed and the transmittance became prominently low...
November 9, 2018: Ultrasonics Sonochemistry
Ding Min
In this study, the joint at low temperature with nano-Al2 O3 particles and Al2 O3 nano + micro particles were fabricated by semisolid assisted ultrasonic vibration with nano-Al2 O3 particle of 50 nm and volume fractions of 1% and micron-Al2 O3 particle of 10 μm and volume fractions of 1%. The joints were examined in order to understand the effects of Al2 O3 additions as microstructure, interface morphology and shear strength as well as mechanical properties of soldering 6061 aluminum alloys. Due to different size, the scallop-shaped solid solution layer was changed into a groove layer, and its thickness of Al3 Zn2 solid solution layer was decreased...
November 9, 2018: Ultrasonics Sonochemistry
Masoud Rahimi, Shahrokh Shahhosseini, Salman Movahedirad
Ultrasound assisted oxidative desulfurization (UAOD) is a promising technology, which can result in ultra-low sulfur fuels in order to reduce the environmental crisis. Most of the researches have been conducted with the experimental approaches. In the present study, a computational fluid dynamic (CFD) model has been developed to investigate the hydrodynamics as well as the reactions involved in a sonoreactor. The results indicate that the physical and chemical effects associated with the ultrasonic field can contribute to the enhancement of the reaction and sulfur removal rates...
November 9, 2018: Ultrasonics Sonochemistry
Christos Vaitsis, Georgia Sourkouni, Christos Argirusis
Metal-organic frameworks (MOFs) have received a lot of attention due to their unique properties and abundant functionalities. Permanent porosity and high surface area are just a few traits that have made them attractive to researchers. They can be prepared as task-specific materials by exploiting the functional group variety and tuning their size and geometry. The main purpose of this review is to present an alternative method of preparing MOF crystals and underline the advantages of ultrasound assisted (sonochemical) synthesis...
November 9, 2018: Ultrasonics Sonochemistry
Louis-Marly Kwedi-Nsah, Takaomi Kobayashi
By using 500 kHz high frequency ultrasound (US), 3,3'-diaminobenzidine (DAB) was treated at pH 2 under air atmosphere. The US effect of DAB absorption at 280 nm was composed at 43 and 141 kHz for the detection of fluorescence. When 100 W of US power was used, the DAB absorption band decreased with exposure time. It was noted that, a new absorption broad band at 350 nm-500 nm appeared only under 141 and 500 kHz. Also, fluorescence spectra of the treated DAB were measured when excited at 370 nm...
November 7, 2018: Ultrasonics Sonochemistry
B A Bhanvase, A Veer, S R Shirsath, S H Sonawane
In the present work, the synthesis of ternary chitosan/zinc oxide/titanium dioxide (CTS-ZnO-TiO2 ) nanocomposite was carried out with the use of mechanical stirring (conventional) and ultrasound assisted method. The characterization of prepared CTS-ZnO-TiO2 adsorbent was carried out using XRD, TEM, FTIR and the results of these analysis methods proved the successful preparation of ternary nanocomposite. Crystal violet (CV) dye was used as a pollutant to observe the adsorption ability of the prepared nanocomposite and the nanocomposite prepared by ultrasonic-assisted method proved to be a better adsorbent...
November 7, 2018: Ultrasonics Sonochemistry
Azar Hakimifar, Ali Morsali
Nanorods of zinc(II) based metal-organic framework (MOF) were prepared via ultrasonic method without any surfactants at room temperature and atmospheric pressure. Control of particle size and morphology was enhanced in this synthesis method. Nanorods of pillared-layer metal organic framework, [Zn2 (ubl)2 (bipy)]·DMF (TMU-18), where ubl (urea-based ligand) is 4,4'-carbonylbis(azanediyl)dibenzoic acid, 4,4'-Bipyridine (bipy) DMF = N,N-dimethyl formamide), was synthesized under ultrasound irradiation in different concentrations of initial precursor...
November 5, 2018: Ultrasonics Sonochemistry
Beibei Zhao, Siwei Sun, Hong Lin, Liding Chen, Si Qin, Weiguo Wu, Baodong Zheng, Zebin Guo
Complex starch is gaining research attention due to its unique physicochemical and functional properties. Lotus seed starch (LS) suspensions (6.7%, w/v) with added green tea polyphenols (GTPs) (10%, w/w) were subjected to ultrasound (200-1000 W)-microwave (150-225 W) (UM) treatment for 15 min. The effects of UM treatment on the physicochemical properties of the LS-GTP system were investigated and exceeded that of microwave or ultrasound alone. The properties (morphology, X-ray diffraction pattern and so on) were affected by GTPs to various extents, depending on ultrasonic power...
November 2, 2018: Ultrasonics Sonochemistry
Buxuan Li, Youwei Gu, Min Chen
Cavitation in liquid with impurities is important in heterogeneous nucleation applications. One of the most widely existing kinds of impurities is solid particles, which can be found in natural water from rivers and specially prepared water such as nanofluids. Understanding the effects caused by the existence of nanoparticles on cavitation in water is vital to the rapidly developed nanotechnologies and medical researches. In this study, cavitation in water with nanoparticles is investigated through molecular dynamics simulations...
October 30, 2018: Ultrasonics Sonochemistry
Zineb Boutamine, Oualid Hamdaoui, Slimane Merouani
No abstract text is available yet for this article.
October 28, 2018: Ultrasonics Sonochemistry
Yuki Ono, Kiyoaki Shinashi, Hisashi Tanaka, Hisashi Harada
The rate of sono-oxidation of KI increased in a CO2 -Ar system compared to Ar alone. Higher values were obtained at 200 kHz with a maximum ratio of about forty. To determine the role of additional CO2 in the system, the effect of the pH of the reactant solution, the additional effect of NaHCO3 , sonoluminescence, and an analysis of products were examined. It appeared that the pH was not a significant contributor to the acceleration of sono-oxidation activity although the rate depended on the pH. On the other hand, in spite of the alkaline solution, the reaction rate in NaHCO3 -KI solution was higher than that in the solution without NaHCO3 ...
October 26, 2018: Ultrasonics Sonochemistry
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