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Ultrasonics Sonochemistry

José Carlos Martínez-Patiño, Beatriz Gullón, Inmaculada Romero, Encarnación Ruiz, Mladen Brnčić, Jana Šic Žlabur, Eulogio Castro
Olive tree pruning biomass (OTP) and olive mill leaves (OML) are the main residual lignocellulosic biomasses that are generated from olive trees. They have been proposed as a source of value-added compounds and biofuels within the biorefinery concept. In this work, the optimization of an ultrasound-assisted extraction (UAE) process was performed to extract antioxidant compounds present in OTP and OML. The effect of the three parameters, ethanol/water ratio (20, 50, 80% of ethanol concentration), amplitude percentage (30, 50, 70%) and ultrasonication time (5, 10, 15 min), on the responses of total phenolic content (TPC), total flavonoid content (TFC) and antioxidant activities (DPPH, ABTS and FRAP) were evaluated following a Box-Behnken experimental design...
May 26, 2018: Ultrasonics Sonochemistry
Candice R Ellison, Sean Overa, Dorin Boldor
Lipids extracted from algal biomass could provide an abundant, rapidly growing, high yield feedstock for bio-diesel and other green fuels to supplement current fossil-based sources. Ultrasound pretreatment is a mechanical cell disruption method that has been shown to enhance lipid recovery from algae due to cavitation effects that disrupt algae cell walls. In this study, a locally grown mixture of Chlorella vulgaris/Cyanobacteria leptolyngbya was sonicated in an ultrasonic reactor with a clamp-on transducer prior to solvent lipid extraction...
May 19, 2018: Ultrasonics Sonochemistry
Mazdak Rasapoor, Mehrdad Adl, Saeid Baroutian, Zeynab Iranshahi, Mohammad Pazouki
It has been proven that ultrasonic pretreatment (UP) has positive effect on biogas generation from previous lab-scale studies. However, that is not always the case in larger scale processes. The purpose of this study was to evaluate the effectiveness of UP to biogas generation in terms of anaerobic digestion process and energy efficiency. Parameters including total solids (TS) and ultrasonic treatment operational parameters of organic solid waste (OSW) resulted from our past lab scale UP studies were applied in this study...
April 30, 2018: Ultrasonics Sonochemistry
Nur Afiqah Azmi, Azila Idris, Nor Saadah Mohd Yusof
Feather keratin is a biomass generated in excess from various livestock industries. With appropriate processing, it holds potential as a green source for degradable biopolymer that could potentially replace current fossil fuel based materials. Several processing methods have been developed, but the use of ultrasonication has not been explored. In this study, we focus on (i) comparing and optimizing the dissolution process of turkey feather keratin through sonication and conventional processes, and (ii) generating a biodegradable polymer material, as a value added product, from the dissolved keratin that could be used in packaging and other applications...
October 2018: Ultrasonics Sonochemistry
Francisco Javier Trujillo
This paper strictly demonstrated a nonlinear Helmholtz equation, with its corresponding new expressions for the wave number of the mixture, for the propagation of sound trough a bubbly liquid. The demonstration was conducted under the assumption of periodicity of volume fluctuations, the acoustic approximation and considering only mono-harmonic pressure oscillations. The model revealed a beautiful symmetry between the average acoustic energy density and the average energy dissipation, as well as between the time average of the first and second derivatives of such fluctuations...
October 2018: Ultrasonics Sonochemistry
Lihua Zhu, Yanjin Guan, Jun Lin, Jiqiang Zhai, Zhendong Xie
A nanocrystalline-amorphous (NC-A) mixed layer was obtained by ultrasonic shot peening (USP) on pure titanium at room temperature and observed by X-ray diffraction pattern (XRD), scanning electron microscope (SEM) and high-resolution transmission electron microscope (HRTEM). The results showed that the amorphization percentage in the NC-A mixed layer increased continuously with the increase of the peening duration, shot diameter and sonotrode amplitude or the decrease of the peening distance. The maximum amorphization percentage achieved in this study was 44...
October 2018: Ultrasonics Sonochemistry
Xuedong Wang, Mei Wang, Xuran Wang, Liyang Du, Fangyu Chu, Weinan Ding, Haidong Gu, Huili Wang
A microextraction method was developed based on utilization of a novel ionic liquid (IL) [C4 MIM][NCA] as disperser and conventional ILs as extractor (IL-IL-DLLME). This method was integrated with an in-situ metathesis reaction to achieve high extraction efficiency by eliminating the loss of analytes in the discarded disperser after microextraction. Ultrasonic energy was compared to traditional mechanical shaking to accelerate the in-situ metathesis reaction. A 3-min ultrasonic treatment provided similar extraction efficiency as a 120-min mechanical shaking...
October 2018: Ultrasonics Sonochemistry
Liliana Santos-Zea, Marilena Antunes-Ricardo, Janet A Gutierrez-Uribe, Jose V García-Pérez, Jose Benedito
Power ultrasound is applied in food technology to intensify extraction processes, due to the phenomena ultrasonic energy induces in the medium, enhancing mass transfer. The purpose of this work was the acoustic characterization of four transducers of different geometries and the evaluation of their performance in the ultrasonically assisted supercritical fluid extraction of antioxidants from oregano. The transducers differed in the amount of energy transmitted into the medium. Designs varied from the base model (T1), a larger cylindrical headmass (T2), a stepped circular section sonotrode (T3) and a multiplate configuration (T4)...
October 2018: Ultrasonics Sonochemistry
Zohreh Parsaee, Nima Karachi, Razieh Razavi
This work introduces novel selective and sensitive optical sensor based on a nano sized triazine based Schiff base (H2 L) immbolized on a transparent glass substrate through the sol-gel process to detection of copper (II) ions in aqueous solutions. This sensor can determine the copper (II) in the range of 8.54 × 10-8 -1.0 × 10-5  mol L-1 with a low detection limit of 1.53 × 10-8  mol L-1 . The optimized geometry of H2 L and its copper complex was obtained based on DFT/B3LYP levels of theory with B3LYP/6-311 + G(d,p) and LANL2DZ/6-311 + G(d,p) basis sets respectively...
October 2018: Ultrasonics Sonochemistry
Olushola S Ayanda, Simphiwe M Nelana, Eliazer B Naidoo
In this study, nano iron (nano-Fe) was successfully synthesized by sodium borohydride reduction of ferric chloride solution to enhance the ultrasonic degradation of phenolsulfonphthalein (PSP). The nano-Fe was characterized by scanning electron microscopy - energy dispersive spectroscopy (SEM-EDX), transmission electron microscopy (TEM), powder X-ray diffraction (XRD), attenuated total reflection - Fourier transform infrared spectroscopy (ATR-FTIR), and Brunauer, Emmett and Teller (BET) surface area determination...
October 2018: Ultrasonics Sonochemistry
Sevgi Polat, Perviz Sayan
The polymorphic phase transformation of β-glycine to α-glycine was analyzed in the absence and presence of three different intensities of ultrasonic irradiation in a batch system at 25 °C. The experiments were performed to explore the effects of ultrasonic irradiation and its intensity on phase transformation time, morphology, storage stability, and filtration characteristics. The crystals obtained with and without ultrasound were characterized by X-ray diffraction (XRD). The XRD results showed that the ultrasound tended to reduce the transformation time...
October 2018: Ultrasonics Sonochemistry
Zhengxu Yan, Lingling Zhang, Zhe Zhao, Huan Qi, Yu Li, Daqiang Cang
This study investigated the inactivation efficiency of ZnO nanofluids against E. coli in sonophotocatalysis with the aeration of nitrogen, oxygen, argon and their mixtures. The results showed that inactivation efficiency was increased when aeration was combined with sonophotocatalysis. Addition of different types of gases could lead to the different inactivation efficiency. The inactivation efficiencies were shown in the following order: no aeration < nitrogen < argon < oxygen < Ar/O2 (3:7) < Ar/O2 (7:3) < Ar/O2 (5:5)...
October 2018: Ultrasonics Sonochemistry
Luyun Cai, Minjie Cao, Ailing Cao, Joe Regenstein, Jianrong Li, Rongfa Guan
Ultrasound assisted vacuum thawing (UVT) or microwave vacuum thawing (MVT) with red seabream fillets were compared to fresh, chill storage thawing, vacuum thawing, microwave thawing and ultrasound thawing. The thermal stability and gelation properties were studied with DSC and dynamic rheology, respectively. Raman spectra before and after H/D isotope exchange and intrinsic fluorescence were used to measure protein secondary and tertiary structure. Low-field NMR was done to measure water migration. The two thawing techniques both retained actin thermal stability and generally retained more stable tertiary structures than the other thawing methods...
October 2018: Ultrasonics Sonochemistry
Eric Keven Silva, Ana Letícia Rodrigues Costa, Andresa Gomes, Matheus A Bargas, Rosiane L Cunha, M Angela A Meireles
In this study, coupling of ultrasound (US) device and rotor-stator (RS), operating at low-energy densities, was studied as an alternative process to individual US and RS to produce modified starch-stabilized oil-in-water emulsions, as well as its potential use to encapsulate eugenol. To this aim, a full factorial design was employed to evaluate the effects of the US nominal power (0, 360 and 720 W) and RS nominal power (0, 150 and 300 W) on the physical properties, encapsulation efficiency and kinetic stability of emulsions produced...
October 2018: Ultrasonics Sonochemistry
Martina Pilloni, Vijay Bhooshan Kumar, Guido Ennas, Ze'ev Porat, Alessandra Scano, Valentina Cabras, Aharon Gedanken
Concentrated suspensions of silver and copper salts in silicone oil were heated to 200 °C and irradiated with ultrasonic energy for different time durations. Characterization of the products was done using X-ray powder diffraction. In most cases, metallic Ag or Cu were obtained, together with their oxide forms Ag2 O and Cu2 O. The salts, used as precursors, do not dissolve in silicone oil but rather form a heterogeneous system, and we assume that local heating, caused by the acoustic cavitation, enhanced their thermal decomposition and the formation of metallic particles...
October 2018: Ultrasonics Sonochemistry
Ruihua Zhang, Xiaoyang Pang, Jing Lu, Lu Liu, Shuwen Zhang, Jiaping Lv
This work investigated the impact of high intensity ultrasound (HIUS) pretreatment on the functional properties and structural characteristics of micellar casein concentrate (MCC). Microfiltered casein protein retentates were treated with HIUS for 0.5, 1, 2, and 5 min prior to spray drying. The results showed that conductivity, solubility, emulsifying, gelling increased significantly as the ultrasonic time prolonged, but the change of pH value were insignificant. In addition, the structural characteristics of MCC for all samples were studied...
October 2018: Ultrasonics Sonochemistry
Arash Asfaram, Mehrorang Ghaedi, Hamedreza Javadian, Alireza Goudarzi
A simple, rapid, and efficient method of dispersive micro solid phase extraction (D-μ-SPE) combined with UV-Vis spectrophotometry via ultrasound-assisted (UA) was applied for the determination and preconcentration of quercetin in extract of watercress (Nasturtium officinale), fruit juice and water samples. The sorbent in this method was synthesized by doping copper and sulfide into the tetragonal structure of SnO2 -nanoparticles (Cu- and S- @SnO2 -NPs) and subsequently loading it on activated carbon (AC). The D-μ-SPE parameters with direct effect on the extraction efficiency of the targeted analyte, such as sample pH, volume of eluent, sorbent mass and ultrasound time were optimized using central composite design method...
October 2018: Ultrasonics Sonochemistry
Ebrahim Alipanahpour Dil, Mehrorang Ghaedi, Arash Asfaram, Ali Akbar Bazrafshan
In this study, gold-magnetic nanocomposite in the presence of ultrasound wave assisted was synthesized and loaded on activated carbon (Au-Fe3 O4 -NCs-AC) by simple, fast and low-cost process. This novel material was applied for ultrasound assisted adsorption of congo red (CR) as model of toxic and even carcinogenic substance from aqueous solution. The detail of morphology and identity of Au-Fe3 O4 -AC was characterized by SEM and TEM techniques and correlation among response to variables such as pH (2-10), adsorbent mass (0...
September 2018: Ultrasonics Sonochemistry
Nasim Karami, Parviz Mohammadi, Aliakbar Zinatizadeh, Farzaneh Falahi, Nasrin Aghamohammadi
The biomass concentration of conventional activated sludge (CAS) process due to low sludge sedimentation in clarifiers is limited to 3000 mg/L. In this study, high-frequency ultrasound wave (1.8 MHz) was applied to enhance the CAS process performance using high Mixed Liquor Suspended Solid (MLSS) concentration. The study conducted using a pilot scale CAS bioreactor (with and without ultrasound) and their performance for treating a hospital wastewater were compared. Experimental conditions were designed based on a Central Composite Design (CCD)...
September 2018: Ultrasonics Sonochemistry
Zhiwu Xu, Zhengwei Li, Jiaqi Li, Zhipeng Ma, Jiuchun Yan
To prevent the formation of Al/Mg intermetallic compounds (IMCs) of Al3 Mg2 and Al12 Mg17 , dissimilar Al/Mg were ultrasonic-assisted soldered using Sn-based filler metals. A new IMC of Mg2 Sn formed in the soldered joints during this process and it was prone to crack at large thickness. The thickness of Mg2 Sn was reduced to 22 μm at 285 °C when using Sn-3Cu as the filler metal. Cracks were still observed inside the blocky Mg2 Sn. The thickness of Mg2 Sn was significantly reduced when using Sn-9Zn as the filler metal...
September 2018: Ultrasonics Sonochemistry
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