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  • Effect of carbon tetrachloride on the luminol sonochemiluminescence reaction kinetics during multibubble cavitation
    Ultrason. Sonochem. (IF 4.218) Pub Date : 2018-06-15
    Bryan A. Corzo, Marco F. Suárez-Herrera

    The sonochemiluminescence (SCL) of luminol reaction was studied in alkaline medium using a dissolution of luminol, sodium carbonate, hydrogen peroxide and carbon tetrachloride. The presence of carbon tetrachloride enhances the SCL reaction up to allow the study of the reaction in real time using a cell phone video camera. This experimental setup allows the study of the cavitation dynamics in real time and through all the reactor, including homogeneous and heterogeneous cavitation zones. Finally, it was tested the effect of ethanol, the ionic strength and pH on the SCL.

    更新日期:2018-06-15
  • Sonochemical synthesis of WS2 nanosheets and its application in sonocatalytic removal of organic dyes from water solution
    Ultrason. Sonochem. (IF 4.218) Pub Date : 2018-06-15
    Alireza Khataee, Paria Eghbali, Mahsa Haddad Irani-nezhad, Aydin Hassani

    In this research, tungsten disulfide (WS2) nanosheets as sonocatalyst were synthesized through a sonochemical route. Characterization of as-synthesized sonocatalyst was carried out by X-ray diffraction (XRD), scanning electron microscopy (SEM), electron dispersive X-ray spectroscopy (EDX), Dot-mapping, high resolution transmission electron microscopy (HRTEM), Brunauer-Emmett-Teller (BET), Fourier transform infrared spectroscopy (FTIR), and ultraviolet-visible diffuse reflectance spectroscopy (UV-vis DRS) analysis. WS2 nanosheets were evaluated for their sonocatalytic performance in order to remove basic violet 10 (BV10) under ultrasonic irradiation. The removal efficiency was maximized (94.01%) via the use of 1 g L-1 catalyst and 10 mg L-1 BV10 at pH = 4.5 and an ultrasonic power of 400 W within a reaction time of 150 min. In addition to BV10, the sonocatalytic elimination for a number of organic dyes viz. direct blue 71, acid blue 92, methylene blue, basic orange 2 and basic red 46 was examined to demonstrate the performance of WS2 nanosheets under the ultrasonic irradiation. The experimentation of trapping was conducted using edetate disodium (EDTA-2Na), tert-butyl alcohol (t-BuOH), and benzoquinone (BQ). According to the results, all radicals participated in the sonocatalytic activity. •OH played a more prominent role than h+ and View the MathML source O 2 - ∙ in the process of BV10 separation. Following five repetitive runs, the nanocomposites revealed a reusability of circa 18% drop in the elimination efficiency. The main removal intermediates were recognized by GC-MS technique.

    更新日期:2018-06-15
  • Extraction of Proteins from Microalgae using Integrated Method of Sugaring-out Assisted Liquid Biphasic Flotation (LBF) and Ultrasound
    Ultrason. Sonochem. (IF 4.218) Pub Date : 2018-06-04
    Revathy Sankaran, Sivakumar Manickam, Yee Jiun Yap, Tau Chuan Ling, Jo-Shu Chang, Pau Loke Show

    In this study, a simple sugaring-out supported by liquid biphasic flotation technique combined with ultrasonication was introduced for the extraction of proteins from microalgae. Sugaring-out as a phase separation method is novel and has been used in the extraction of metal ions, biomolecules and drugs. But, its functioning in protein separation from microalgae is still unknown. In this work, the feasibility of sugaring-out coupled with ultrasound for the extraction of protein was investigated. Primary studies were carried out to examine the effect of sonication on the microalgae cell as well as the separation efficiency of the integrated method. Effect of various operating parameters such as the concentration of microalgae biomass, the location of sonication probe, sonication time, ultrasonic pulse mode (includes varying ON and OFF duration of sonication), concentration of glucose, types of sugar, concentration of acetonitrile and the flow rate in the flotation system for achieving a higher separation efficiency and yield of protein were assessed. Besides, a large-scale study of the integration method was conducted to verify the consistency of the followed technique. A maximum efficiency (86.38%) and yield (93.33%) were attained at the following optimised conditions: 0.6% biomass concentration, 200 g/L of glucose concentration, 100% acetonitrile concentration with 5 min of 5s ON/10s OFF pulse mode and at a flow rate of 100 cc/min. The results obtained for large scale were 85.25% and 92.24% for efficiency and yield respectively. The proposed liquid biphasic flotation assisted with ultrasound for protein separation employing sugaring-out demonstrates a high production and separation efficiency and is a cost-effective solution. More importantly, this method provides the possibility of extending its application for the extraction of other important biomolecules.

    更新日期:2018-06-04
  • Eu-doped ZnO nanoparticles: Sonochemical synthesis, characterization, and sonocatalytic application
    Ultrason. Sonochem. (IF 4.218) Pub Date : 2015-03-30
    Alireza Khataee, Atefeh Karimi, Mahmoud Zarei, Sang Woo Joo

    Undoped and europium (III)-doped ZnO nanoparticles were prepared by a sonochemical method. The prepared samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), and X-ray photoelectron spectroscopy (XPS) analysis. The crystalline sizes of undoped and 3% Eu-doped ZnO were found to be 16.04 and 8.22 nm, respectively. The particle size of Eu-doped ZnO nanoparticles was much smaller than that of pure ZnO. The synthesized nanocatalysts were used for the sonocatalytic degradation of Acid Red 17. Among the Eu-doped ZnO catalysts, 3% Eu-doped ZnO nanoparticles showed the highest sonocatalytic activity. The effects of various parameters such as catalyst loading, initial dye concentration, pH, ultrasonic power, the effect of oxidizing agents, and the presence of anions were investigated. The produced intermediates of the sonocatalytic process were monitored by GC–Mass (GC–MS) spectrometry.

    更新日期:2018-06-03
  • Synthesis of poly(acrylamide-co-itaconic acid)/MWCNTs superabsorbent hydrogel nanocomposite by ultrasound-assisted technique: Swelling behavior and Pb (II) adsorption capacity
    Ultrason. Sonochem. (IF 4.218) Pub Date : 2017-12-16
    Alireza mohammadinezhad, Gholam Bagheri Marandi, Majid Farsadrooh, Hamedreza Javadian

    In this research, the poly (acrylamide-co-itaconic acid)/multi walled carbon nanotubes (P(AAm-co-IA)/MWCNTs) as a novel superabsorbent hydrogel nanocomposite was synthesized by graft copolymerization of acrylamide (AAm) and itaconic acid (IA) mixture in the presence of the MWCNTs using ammonium persulfate (APS) as a free radical initiator and methylenebisacrylamide (MBA) as a crosslinker under ultrasound-assisted condition. The blank P(AAm-co-IA) hydrogel and its composite with the MWCNTs were characterized by means of SEM, FTIR, XRD and TGA methods. The effects of different parameters such as pH, time, the MWCNTs content and salt solutions on swelling behavior were investigated. The stability of the hydrogel increased by any increase in the MWCNTs content, which might be attributed to the hydrophobic nature of the MWCNTs as well as the increase of the crosslinker density. The water retention capacity (WRC) of the P(AAm-co-IA) hydrogel increased in the presence of the MWCNT (10 wt%). The synthesized hydrogel nanocomposite was studied for Pb (II) adsorption from aqueous solution. The effects of different parameters such as contact time (5-90 min), Pb (II) initial concentration (25-175 mg/L) and initial pH (1.5-4.5) of solution on Pb (II) adsorption were investigated by batch method. In comparison to P(AAm-co-IA) hydrogel, the P(AAm-co-IA)/MWCNTs hydrogel nanocompoite showed better adsorption behavior toward Pb (II). One of the most important aspects of this research was to investigate the effects of ultrasonic waves on polymer matrix and its ability.

    更新日期:2018-06-03
  • In situ observation of single cell response to acoustic droplet vaporization: Membrane deformation, permeabilization, and blebbing
    Ultrason. Sonochem. (IF 4.218) Pub Date : 2018-02-06
    Dui Qin, Lei Zhang, Nan Chang, Pengying Ni, Yujin Zong, Ayache Bouakaz, Mingxi Wan, Yi Feng

    In this study, the bioeffects of acoustic droplet vaporization (ADV) on adjacent cells were investigated by evaluating the real-time cell response at the single-cell level in situ, using a combined ultrasound-exposure and optical imaging system. Two imaging modalities, high-speed and fluorescence imaging, were used to observe ADV bubble dynamics and to evaluate the impact on cell membrane permeabilization (i.e., sonoporation) using propidium iodide (PI) uptake as an indicator. The results indicated that ADV mainly led to irreversible rather than reversible sonoporation. Further, the rate of irreversible sonoporation significantly increased with increasing nanodroplet concentration, ultrasound amplitude, and pulse duration. The results suggested that sonoporation is correlated to the rapid formation, expansion, and contraction of ADV bubbles near cells, and strongly depends on ADV bubble size and bubble-to-cell distance when subjected to short ultrasound pulses (1 μs). Moreover, the displacement of ADV bubbles was larger when using a long ultrasound pulse (20 μs), resulting in considerable cell membrane deformation and a more irreversible sonoporation rate. During sonoporation, cell membrane blebbing as a recovery manoeuvre was also investigated, indicating the essential role of Ca2+ influx in the membrane blebbing response. This study has helped us gain further insights into the dynamic behavior of ADV bubbles near cells, ADV bubble-cell interactions, and real-time cell response, which are invaluable in the development of optimal approaches for ADV-associated theranostic applications.

    更新日期:2018-06-03
  • Experimental Investigation of the Thermal and Disinfection Performances of a Novel Hydrodynamic Cavitation Reactor
    Ultrason. Sonochem. (IF 4.218) Pub Date : 2018-02-26
    Xun Sun, Jong Jin Park, Hyun Soo Kim, Seung Ho Lee, Si Jin Seong, Ae Son Om, Joon Yong Yoon

    In the present study, we proposed an effective, efficient, and economical approach to disinfect water using a novel, advanced, rotational hydrodynamic cavitation reactor (HCR). First, analyses of the flow field and cavitation generation mechanism in the HCR were conducted through visualization of the reactor flow field using a high-speed camera. Second, the thermal performance was tested in 20 experiments with various rotational speeds of the rotor (2700, 3000, 3300, and 3600 rpm) and pump pressure settings (0.0, 0.5, 0.7, 1.0, and 1.5 bar gauge pressure). The HCR maximally achieved a heat generation rate of 48.15 MJ/h and thermal efficiency of 82.18%. Then, the disinfection effect was evaluated using water that simulated an effluent containing Escherichia coli (E. coli) for various flow rates (8, 11, and 14 L/min), a pump pressure setting fixed at 0.5 bar, and a rotational speed of 3600 rpm. In addition, an economical assessment of the disinfection processes was performed by considering the measured electric consumption. The thermal effect generated by the HCR was the dominant factor affecting the concentration of E. coli. The HCR achieved a 100% disinfection rate with a 4.3 L/min treatment rate and a cost of US $ 3.019/m3 at the optimal flow rate. The effects of the pressure setting and rotational speed on the performance were discussed in detail. Finally, compared to the recent studies, the treatment rate of the HCR is several hundred times greater than that obtained by the HCRs utilized in those studies, and also has a reasonable cost.

    更新日期:2018-06-03
  • 更新日期:2018-06-02
  • Investigation on ultrasonic volume effects: stress superposition, acoustic softening and dynamic impact
    Ultrason. Sonochem. (IF 4.218) Pub Date : 2018-06-01
    Jun Hu, Tetsuhide Shimizu, Ming Yang

    Conventional high power ultrasonic vibration has been widely used to improve manufacturing processes like surface treatment and metal forming. Ultrasonic vibration affects material properties, leading to a flow stress reduction, which is called ultrasonic volume effect. The volume effect contains multi-mechanisms such as stress superposition due to oscillatory stress, acoustic softening by easier dislocation motion and dynamic impact leading to extra surface plastic deformation. However, most researches ignored the stress superposition for the convenience of measurement, and few studies considered ultrasonic dynamic impact since the relatively low ultrasonic energy in macro scale. The purpose of this study is to investigate the characteristics and mechanisms of different ultrasonic volume effects in micro-forming. A 60 kHz longitudinal ultrasonic-assisted compression test system was developed and a series of ultrasonic-assisted compression tests at different amplitudes on commercially pure aluminum A1100 in micro-scale were carried out combining the surface analysis by SEM, EDX and micro-hardness test. Three different ultrasonic volume effects, stress superposition, acoustic softening and dynamic impact, were confirmed in the ultrasonic-assisted compression tests. In order to quantitatively predict stress superposition, a hybrid model for stress superposition is developed considering the elastic deformation of experimental apparatus in practice, the evolution of the modeling results fitted well with the experimental results. With low ultrasonic amplitude, stress superposition and acoustic softening occurred because vibrated punch contacted with the specimen all the time during compression. However, with higher amplitude, due to the extra surface plastic deformation by larger ultrasonic energy, forming stress was further reduced by the ultrasonic dynamic impact. A possible method to distinguish the effects of dynamic impact and acoustic softening is to analyze the waveform of the oscillatory stress in the process. In the case of ultrasonic dynamic impact effect, a higher amount of oxidation was observed on the specimen surface, which could be the result of local heating by surface plastic deformation and surface friction when the vibrated punch detached from the specimen. The findings of this study provide an instructive understanding of the underlying mechanisms of volume effects in ultrasonic-assisted micro-forming.

    更新日期:2018-06-01
  • Ultrasound- and Microwave-Assisted Convective Drying of Carrots – Process Kinetics and Product’s Quality Analysis
    Ultrason. Sonochem. (IF 4.218) Pub Date : 2018-06-01
    Joanna Kroehnke, Justyna Szadzińska, Marcin Stasiak, Elżbieta Radziejewska-Kubzdela, Róża Biegańska-Marecik, Grzegorz Musielak
    更新日期:2018-06-01
  • Characterisation of flow behaviour and velocity induced by ultrasound using particle image velocimetry (PIV): Effect of fluid rheology, acoustic intensity and transducer tip size
    Ultrason. Sonochem. (IF 4.218) Pub Date : 2018-05-30
    Jonathan J. O'Sullivan, Cyrus J.U. Espinoza, Olga Mihailova, Federico Alberini

    Acoustic streaming phenomena of ultrasound propagation through liquid media was investigated experimentally employing particle image velocimetry (PIV). Parameters associated with the ultrasonic processor of ultrasonic amplitude (i.e., acoustic power) and transducer tip diameter (i.e., surface area), as well as, fluid rheology (i.e., water, glycerol solution and CMC solution), were studied for their effects on overall flow behaviour and fluid velocity. PIV yielded velocity gradient maps, demonstrating the acoustic streaming phenomena of ultrasound and its associated flow behaviour as a function of ultrasonic amplitude and fluid rheology, whereby increasing amplitude allowed for greater penetration of the acoustic-beam through the bulk of the fluid, and increasing fluid rheology yielded the converse effect. Moreover, upon impingement of the acoustic-beam with the base of vessel, vortex formation occurred, yielding a recirculation pattern. The maximum observed fluid velocities for water, glycerol solution and CMC solution were 0.329 m s-1, 0.423 m s-1, and 0.304 m s-1, respectively (large diameter sonotrode tip for an ultrasonic amplitude of 80%). Furthermore, shear rates were attained (maximum values of 24.25 s-1), and Reynolds numbers were determined in order to assess the degree of turbulence as a function of investigated parameters.

    更新日期:2018-05-31
  • Wetting mechanism of Sn to Zr50.7Cu28Ni9Al12.3 bulk metallic glass assisted by ultrasonic treatment
    Ultrason. Sonochem. (IF 4.218) Pub Date : 2018-05-30
    Zhiwu Xu, Zhengwei Li, Shijiang Zhong, Zhipeng Ma, Jiuchun Yan

    In this work, pure Sn was used to wet Zr50.7Cu28Ni9Al12.3 bulk metallic glasses (BMGs) assisted by ultrasonic. Without ultrasonic treatment, pure Sn showed a non-wetting condition to BMG. Ultrasonic vibration facilitated the wetting of Sn to BMG. Prior to ultrasonication for 30 s, only physical adsorption formed at the Sn/BMG interface. Increasing ultrasonic time led to the alteration of the bond at the Sn/BMG interface from point contact to local surface contact, and to diffusion layer. Two bonding modes of order–order and order–disorder were discovered at the Sn/BMG interface. Cu content was higher than the other elements near the bonding interface. Longer diffusion distances of Sn into the BMG were obtained at high ultrasonic power, high temperature and large dip depth.

    更新日期:2018-05-31
  • Sonoprecipitation Dispersion of ZnO Nanoparticles over Graphene Oxide Used in Photocatalytic Degradation of Methylene Blue in Aqueous Solution: Influence of Irradiation Time and Power
    Ultrason. Sonochem. (IF 4.218) Pub Date : 2018-05-30
    Mahdi Zarrabi, Mohammad Haghighi, Reza Alizadeh

    In this paper, ZnO/Graphene Oxide (ZnO/GO) is synthesized via ultrasound assisted precipitation method and the effect of power and ultrasound time irradiation is studied on photocatalyst properties. The synthesized samples are used for methylene blue (MB) degradation as an organic water pollutant. Physicochemical properties of the samples are investigated by XRD, FESEM, EDX, BET-BJH, FTIR and DRS techniques. Moreover, pHpzc of the sample with the best performance is calculated to study the effect of acidity on the photocatalyst efficiency in photocatalytic process. Ultrasound has a positive effect on photocatalyst performance. That is because of its effect on distribution of particles and band gap, but it has no effect on photostability of the nanocomposite. Sonication has modified distribution of particles by enhancing the active sites for oxidation process. Making structural gaps by ultrasound irradiation increases available surface area which has a similar effect on photocatalyst performance. Graphene oxide as electron collector and transporter prevents electron-hole recombination and it can be an acceptable reason for enhancement at photocatalyst performance. Finally, some of operational parameters such as pH, photocatalyst loading and dye concentration are investigated.

    更新日期:2018-05-31
  • Mysteries of bulk nanobubbles (ultrafine bubbles); Stability and radical formation
    Ultrason. Sonochem. (IF 4.218) Pub Date : 2018-05-30
    Kyuichi Yasui, Toru Tuziuti, Wataru Kanematsu

    There are two main mysteries in bulk nanobubbles which are cavitation nuclei. One is the mechanism of stability of a bulk nanobubble. The other is the problem whether OH radicals are produced from bulk nanobubbles without a dynamic stimulus. For the former problem, several proposed models are briefly reviewed. The dynamic equilibrium model is discussed in details that a bulk nanobubble is stabilized by a partial coverage of the bubble surface by a hydrophobic material. The TEM images of bulk nanobubbles seem to support the dynamic equilibrium model. For the latter problem, numerical simulations of dissolution of an air nanobubble are reviewed, which suggest that no OH radical is produced from a dissolving nanobubble. A possible role of H2O2 generated during bulk nanobubble production using hydrodynamic cavitation is briefly discussed in relation to the experimental results of “OH radical” detection.

    更新日期:2018-05-31
  • Hydrodynamic cavitation assisted degradation of persistent endocrine-disrupting organochlorine pesticide Dicofol: Optimization of operating parameters and investigations on the mechanism of intensification
    Ultrason. Sonochem. (IF 4.218) Pub Date : 2018-05-30
    Debabrata Panda, Sivakumar Manickam

    Dicofol, a recommended Stockholm convention persistent organic pollutants (POPs) candidate is well known for its endocrine disruptive properties and has been extensively used as an organochlorine pesticide worldwide. The Hydrodynamic cavitation (HC) treatment of Dicofol in aqueous media induced by a liquid whistle reactor (LWR) has been investigated while considering important parameters such as inlet pressure, initial concentration of Dicofol, solution temperature, pH, addition of H2O2 and radical scavenger for the extent of degradation. The pseudo-first-order degradation rate constant (k) was determined to be 0.073 min-1 with a cavitational yield of 1.26 × 10-5 mg/J at optimum operating conditions and a complete removal of Dicofol was achieved within 1 h of treatment. Considering the removal rate and energy efficiency, the optimal inlet pressure was found to be 7 bar, resulting in a cavitation number of 0.17. High performance liquid chromatography (HPLC) and Gas chromatography mass spectroscopy (GC-MS) analyses indicated a sharp decline in the concentration of Dicofol with treatment time and indicated the presence of degraded products. An 85 % total organic carbon (TOC) removal was achieved within 1 h of treatment time, demonstrating successful mineralization of Dicofol. The obtained results suggest that the degradation of Dicofol followed thermal decomposition and successive recombination reactions at bubble-vapor interface. Overall, the attempted hydrodynamic cavitation demonstrated successful and rapid removal of endocrine disruptive chemicals such as Dicofol and is expected to provide efficient solution for wastewater treatment.

    更新日期:2018-05-31
  • Experimental and theoretical study of crude oil pretreatment using low-frequency ultrasonic waves
    Ultrason. Sonochem. (IF 4.218) Pub Date : 2018-05-29
    Ali Khajehesamedini, Ali Sadatshojaie, Payam Parvasi, Mohammad Reza Rahimpour, Mohammad Mehdi Naserimojarad

    In this work, an ultrasound experimental setup was designed to investigate the feasibility of using low-frequency ultrasonic waves as a substitute to reduce the consumption of chemical demulsifiers in the pretreatment of crude oil. The experiments were planned to study the effects of irradiation time, ultrasonic field intensity and initial water content on the efficiency of separation. The results of experiments showed that by selecting a proper irradiation time and field intensity, it is possible to decrease the usage of demulsifiers by 50%. Moreover, a population balance model was proposed to explicate the experimental data. A hybrid coalescence model was developed to determine the frequency of aggregation. The parameters of the model were estimated by linear regression. The parameter estimation was performed using a parallel execution of the particle swarm optimization algorithm. The results of the model showed a decent agreement with the experimental data.

    更新日期:2018-05-29
  • The effect of high-energy environments on the structure of laccase-polymerized poly(catechol)
    Ultrason. Sonochem. (IF 4.218) Pub Date : 2018-05-29
    Jing Su, Tarsila G. Castro, Jennifer Noro, Jiajia Fu, Qiang Wang, Carla Silva, Artur Cavaco-Paulo
    更新日期:2018-05-29
  • Optimized removal of natural organic matter by ultrasound-assisted coagulation of recycling drinking water treatment sludge
    Ultrason. Sonochem. (IF 4.218) Pub Date : 2018-05-25
    Zhiwei Zhou, Yanling Yang, Xing Li, Pangyi Li, Tingting Zhang, Xuquan Lv, Lujian Liu, Jun Dong, Dan Zheng

    In previous work we have shown that recycling pre-sonciated drinking water treatment sludge (DWTS) could improve coagulated water quality. Here, the removal of naturally occurring organic matter of source water was further optimized using response surface methodology (RSM) with Box-Behnken Design (BBD). The four variables, i.e., volumetric recycling ratio of DWTS, energy density, ultra-sonication time and duty cycle in an experimental jar test of ultrasound assisted flocculation-coagulation were optimized. All the variables showed a significant effect on dissolved organic carbon (DOC) removal of source water (p < 0.05), of which the duty cycle had a stronger effect on the removal performance compared to the other independent variables. The predicted optimal DOC removal rate was 36.94%, and this matched well the observed performance of 36.54 ± 0.56%, obtained by ultra-sonicating the sludge prior to recycling using a power input of 1.015W/mL, an ultra-sonciation time of 9min50sec, and a duty cycle of 80%, while the volumetric recycling ratio of DWTS was 5.8%. The natural organic matter fractions in the coagulated water samples indicated that recycling sonicated DWTS that had been washed prior to recycling in order to remove solubilzied extracellulaer polymers could enhance removal of hydrophobic acids and 3-30 kDa fractions, but this treatment increased the presence of substances with molecular weight <3 kDa. Humic-like substances were effectively removed while tyrosine-like substances could be enriched. Sludge samples (raw DWTS, sonicated DWTS, sludge formed by recycling raw DWTS, and sludge formed by recycling sonicated DWTS without solubilzied extracellular organics) were characterized by XRF, X-ray diffraction patterns and FE-SEM-EDS to reveal possible physical characteristics that could be related to the DOC removal performance.

    更新日期:2018-05-27
  • Optimization of ultrasound-assisted extraction of biomass from olive trees using response surface methodology
    Ultrason. Sonochem. (IF 4.218) Pub Date : 2018-05-26
    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. The optimal conditions obtained from the model, taking into account simultaneously the five responses, were quite similar for OTP and OML, with 70% amplitude and 15 minutes for both biomasses and a slight difference in the optimum concentration of ethanol. (54.5% versus 51.3% for OTP and OML, respectively). When comparing the antioxidant activities obtained with OTP and OML, higher values were obtained for OML (around 40% more than for OTP). The antioxidant activities reached experimentally under the optimized conditions were 31.6 mg of TE/ g of OTP and 42.5 mg of TE/ g of OML with the DPPH method, 66.5 mg of TE/ g of OTP and 95.9 mg of TE/ g of OML with the ABTS method, and 36.4 mg of TE/ g of OTP and 49.7 mg of TE/ g of OML with the FRAP method. Both OTP and OML could be a potential source of natural antioxidants.

    更新日期:2018-05-27
  • The effect of high intensity ultrasound (HIU) on the kinetics of crystallization of sucrose: Elimination of latent period ☆
    Ultrason. Sonochem. (IF 4.218) Pub Date : 2018-05-26
    Kaman Singh, Satya Prakash Gupta, Ashok Kumar, Ajay Kumar

    The application of a technique to eliminate the latent period during crystallization of sucrose by high intensity ultrasound (HIU) was investigated in this paper. Employing HIU (20 kHz, 750W) to crystallization of sucrose, latent period was eliminated and it was found to obey first order kinetics (K ∼10-5 sec-1) in the temperature range of 30-50°C. Employing Arrhenius equation, the average energy of activation (Ea) estimated as 5.0 kcal mol-1. Traditional knowledge indicates that crystallization is sufficiently spontaneous; however, the magnitude of “K” and other thermodynamic quantities of the process indicate that crystallization is actually a slow process. Generally, chemical reactions which posses low rate constants, need the high energy of activation. On the contrary, the energy of activation is appreciably less. The energy of activation with a rate constant of the order of 10-5 sec-1 could be predicted of the order of 20 kcal mol-1 at 27 °C. The low energy of activation for crystallization of sucrose is of interest. A very interesting elucidation can be had from neutron diffraction data and transport property of the sucrose which is discussed in details in this paper.

    更新日期:2018-05-27
  • Combining pressurized liquids with ultrasound to improve the extraction of phenolic compounds from pomegranate peel (Punica granatum L.)
    Ultrason. Sonochem. (IF 4.218) Pub Date : 2018-05-23
    Beatriz Rocchetti Sumere, Mariana Corrêa de Souza, Mariana Pacífico dos Santos, Rosângela Maria Neves Bezerra, Diogo Thimoteo da Cunha, Julian Martinez, Mauricio Ariel Rostagno
    更新日期:2018-05-24
  • Synergistic effect between ultrasound and fierce mechanical activation towards mineral extraction: a case study of ZnO ore
    Ultrason. Sonochem. (IF 4.218) Pub Date : 2018-05-23
    Hongping He, Jianglin Cao, Ning Duan

    Though the positive role of ultrasound has been confirmed in the mineral extraction, its potential towards fiercely mechanically-activated mineral was not yet mentioned. In this study, as a novel mechanical activation style, bead milling (BM) was presented and ZnO ore was selected to determine its effectiveness. Results showed that median particle size of ZnO ore could be pulverized to as low as 1/164 of its original value (from ∼29.2 μm to ∼178 nm), indicating much higher activation potential of BM than that of conventional ball milling. Besides, structure destruction, even phase transformation with the direct participation of airborne CO2 occurred. All these processes rendered the superior activation capacity of BM. In view of the extraction promotion, the combination of ultrasound and BM exerted more pronounced effect than those of individual ones, indicating the synergistic effect between extra energy input (by ultrasound) and inner energy storage (by fierce BM). The classic shrinking core model with the product layer diffusion as the rate-controlling step was found to well model the extraction kinetics. The modeling disclosed high capability of ultrasound and BM combination in decreasing the activation energy (Ea) (from 54.6 kJ/mol to 26.4 kJ/mol), while ultrasound, BM could only decrease the Ea to 44.9 kJ/mol, 41.5 kJ/mol, respectively. The dual roles of ultrasound were specially highlighted: (i) participation in the extraction process via direct energy input, (ii) regulation of the aggregation that the activated ore suspension was confronted with.

    更新日期:2018-05-24
  • Structural, morphological and thermal properties of nanocomposites poly(GMA)/clay prepared by ultrasound and in-situ polymerization
    Ultrason. Sonochem. (IF 4.218) Pub Date : 2018-05-23
    Zakaria Cherifi, Bouhadjar Boukoussa, Aniss Zaoui, Mohammed Belbachir, Rachid Meghabar

    This work focuses on the preparation and characterization of nanocomposites poly(glycidylmethacrylate)/organoclay. Effect of the organoclays nature and the preparation method were investigated in order to evaluate their structural, morphological and thermal properties. X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), nitrogen sorption at 77 K, scanning and transmission electronic microscopy (SEM, TEM) and thermogravimetric analysis (TGA) were employed to determine the features of the obtained materials. In the first step, the Algerian clay was modified by ultrasonic-assisted method using different concentrations of CTAB or TBAHS in which they used as green nano-filler. A series of nanocomposites were prepared by two different methods. The first deals the in-situ polymerization of GMA within the organoclay galleries and the second pathway involves the use of solution blending of poly(GMA) assisted by ultrasound. The obtained results confirm the intercalation of surfactants within the clay layers, while the nanocomposites obtained by the both methods showed different morphologies and structures in which the exfoliated and intercalated forms were obtained. Both the nanocomposites displayed significant enhancement in the thermal stabilities compared to the unmodified poly(GMA). The best results in terms of reaction time, clay dispersion and nanocomposite yield were obtained by the ultrasound method.

    更新日期:2018-05-24
  • A novel ultrasonic-assisted method for enhanced yield of light oil in the thermal cracking of residual oil
    Ultrason. Sonochem. (IF 4.218) Pub Date : 2018-05-23
    Guanlong Song, De-Hui Wang, Zhiwei Zhang, Mei Liu, Qian Xu, De-Zhi Zhao
    更新日期:2018-05-24
  • Curcumin-assisted ultrasound exfoliation of graphite to graphene in ethanol
    Ultrason. Sonochem. (IF 4.218) Pub Date : 2018-05-22
    Rahul Navik, Yanzhe Gai, Wucong Wang, Yaping Zhao
    更新日期:2018-05-23
  • Sonochemical synthesis and properties of two new nanostructured silver(I) coordination polymers
    Ultrason. Sonochem. (IF 4.218) Pub Date : 2018-05-22
    Jun-Xuan Li, Zhan-Bin Qin, Yue-Hua Li, Guang-Hua Cui

    Two new Ag(I) coordination polymers (CPs), namely, Ag(L)(Htp) (1) and [Ag(L)]·(Htp)·2H2O (2) were synthesized from the long flexible ligand of 1,6-bis(2-methylbenzimidazolyl)hexane (L), terephthalic acid (H2tp) and different silver(I) salts using hydrothermal and sonochemical methods, These CPs were characterized by elemental analysis, IR spectra, scanning electron microscopy, single-crystal and powder X-ray diffraction analysis. 1 features a uninodal 3-connected 2D hcb layered structure, while 2 exhibits an infinite 1D linear chain and ultimately extended into 3D supramolecular framework via O–H⋯O and Ag···O interactions. In addition, the effect of various sonication concentrations of the initial reagents, ultrasonic time and power of ultrasound irradiation on the size and morphology of nanostructured 1 and 2 were evaluated. Nano-sized 1 and 2 exhibit relatively high performance as UV light driven photocatalysts for the degradation of methylene blue.

    更新日期:2018-05-23
  • Depth effect on the inertial collapse of cavitation bubble under ultrasound: Special emphasis on the role of the wave attenuation
    Ultrason. Sonochem. (IF 4.218) Pub Date : 2018-05-21
    Nassim Kerabchi, Slimane Merouani, Oualid Hamdaoui

    Acoustic cavitation concentrates and releases a very large amount of energy in localized areas, which can be used for many physical and chemical processes. Even though acoustic cavitation has been studied widely for decades in lab-scale sonoreactors, only few studies have been devoted to characterize this event in big-scale sonoreactors, where the liquid depth may have a critical influence on the bubble collapse. The present computational study furnished numerical data about the effect of depth (z = 0-10 m) on acoustic cavitation with special focus on the role of attenuation of the ultrasound wave on the dramatic conditions developed within bubbles at collapse. The used mathematical model takes into account the liquid compressibility, surface tension and viscosity, depth as well as the attenuation of the ultrasound wave with depth. It was found that the maximum bubble temperature (Tmax) and pressure (pmax) at the collapse diminished considerably with deepening into water up to 10 m with a considerable contribution of the ultrasound wave attenuation in the overall reduction event. The reduction in Tmax and pmax with depth was more pronounced at higher frequency (1000 kHz) and lower temperature (10 °C) in which losses of about up to 72% in Tmax and till 94% in pmax (as compared with values at z = 0) were obtained at z = 10 m. Depending on operating conditions, i.e. frequency, acoustic intensity or liquid temperature, the ultrasound wave attenuation may contribute with up to 47% and 79% in the overall reductive effect of depth toward Tmax and pmax, respectively. These results were discussed, interpreted and used to support some available experimental observations. Finally, the results of the present study may help in designing large-scale sonoreactors through providing data about the effect of one of the missing links between lab-scale sonoreactors and industrial large-scale sonoreactors.

    更新日期:2018-05-22
  • Title: Central Composite Design Parameterization of Microalgae/Cyanobacteria Co-culture Pretreatment for Enhanced Lipid Extraction Using an External Clamp-On Ultrasonic Transducer
    Ultrason. Sonochem. (IF 4.218) Pub Date : 2018-05-19
    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. This configuration allows for a non-contact delivery method of ultrasonic energy with improved operational advantages (no fouling of transducer, continuous operation, and fully scalable design). A central composite design (CCD) was implemented to statistically analyze and evaluate the effect of ultrasonic power (350 to 750 W) and treatment time (5 to 30 minutes) on lipid yield. Lipid recovery was found to increase with both ultrasonic power and treatment time. Total lipid yields (on dry biomass basis) extracted via the Bligh and Dyer method from Chlorella vulgaris/cyanobacteria co-culture ranged from 8.3% for untreated algae to 16.9% for algae sonicated with 750W power for 30 minutes, which corresponds to more than a doubling of lipid recovery due to ultrasound pretreatment. Increased power and treatment times were found to increase the degree of cell disruption as observed in the SEM and TEM images after ultrasonic pretreatment. Additionally, hexane (1:1 v/v) was evaluated as an alternative to the standard Bligh & Dyer (2:2:1.8 v/v/v chloroform/methanol/cell suspension) lipid extraction solvent system. On average, the Bligh and Dyer method extracted on average over twice the amount of lipids compared to hexane extraction. The lipid profile of the algae extracts indicates high concentrations of lauric acid (12:0), palmitic acid (16:0), stearic acid (18:0), oleic acid (18:1), and linoleic acid (18:2). This particular configuration of an ultrasonic system proved to be a viable method for the pretreatment of algae for enhanced lipid yields. Future research should focus on identifying alternative extraction solvents and expanding the range of treatment conditions to optimize the ultrasonic power and treatment times for maximum lipid recovery.

    更新日期:2018-05-19
  • Water disinfection by hydrodynamic cavitation in a rotor-stator device
    Ultrason. Sonochem. (IF 4.218) Pub Date : 2018-05-19
    Luis M. Cerecedo, Cesar Dopazo, Rafael Gomez-Lus

    The efficiency of a rotor-stator device for water disinfection based on hydrodynamic cavitation is investigated. Water is infected with E.coli and E.faecalis with initial concentrations in the range 5x102-1.2x106 5 x 10 2 - 1.2 x 10 6 CFU/ml. Various geometries of the cavitation channel between rotor and stator are tested, achieving bacterial annihilation in less than 10 minutes of treatment times. Microorganism permanent elimination is verified via micro-seeding to discard viable non-culturable bacteria; micro-seeding was done for those samples displaying no CFU growth via normalized cultures on a Petri dish. TEM photographs are analyzed and the extent of bacterial damages is tentatively correlated with the various cavitation mechanisms. Rotor-stator cavitation assemblies used in the current research are between one and two orders of magnitude more energy efficient than those tested by other investigators. Acoustic pressure spectra are measured to assess the implosion intensity. Parametric analyses are conducted changing the rotor diameter (110-155 mm), the cavitation channel contraction ratio, Amax/Amin(4.56-5.0) A max / A min ( 4.56 - 5.0 ) , and the number of contractions (Nr:58-80 N r : 58 - 80 rotor vanes; Ns:8-16 N s : 8 - 16 stator vanes).

    更新日期:2018-05-19
  • Effect of ultrasound pre-treatment on adsorbent in dye adsorption compared with ultrasound simultaneous adsorption
    Ultrason. Sonochem. (IF 4.218) Pub Date : 2018-05-19
    Suk Khe Low, Mei Ching Tan, Nyuk Ling Chin

    Ultrasound was applied simultaneous with adsorption process in most of the previous study. However, this method is not practical to treat huge amount of coloured wastewater effluent. In this study, the efficiency of ultrasound pre-treated peanut husk powder at different power levels (1.5–3.5 W) in dye adsorption with several conditions of initial dye concentration (20–100 mg/L), contact time (0.5–5 h), solution pH (2–8), and dosage (0.1–0.3 g) was study and compared with ultrasound simultaneous adsorption process and the control. Adsorption efficiency of indirect ultrasound pre-treated peanut husk powder has increased 25.78%, 13.64% and 1.5% compared with the control, ultrasound simultaneous adsorption and direct ultrasound pre-treated sample respectively at 60 mg/L of initial dye concentration. Indirect ultrasound pre-treated sample at 3.5 W has achieved the highest adsorption efficiency of 89.96% at solution pH 8 and 94.83% at 0.3 g dose for 3 h. The surface feature and textural properties of samples were characterized by using scanning electron microscopy and surface characterization analyser. The result indicated that more porous structure was created on the ultrasound pre-treated sample at increasing power levels.

    更新日期:2018-05-19
  • Ultrasonic modification of carbonate scale electrochemically deposited in tap water
    Ultrason. Sonochem. (IF 4.218) Pub Date : 2018-05-19
    G. Vasyliev, S. Vasylieva, A. Novosad, Y. Gerasymenko

    Influence of the ultrasound intensity (28 kHz, 1.1−7.5 W/cm2) on CaCO3 nucleation-growth on the surface of a cylinder mild steel electrode rotating at 500 rpm was studied in tap water. The deposition kinetics was analyzed by chronoamperometry; the calcareous layer was characterized by gravimmetry, scanning electron microscopy and XRD. Application of ultrasound to calcium carbonate crystallization affects nucleation sites density, mass-transport rate and cavitation erosion of the deposits. Lower intensity ultrasound reduces scale porosity and area density by increasing nucleation site density and accelerating the mass transport. Higher intensity ultrasound promotes cavitation erosion of the formed layer, thus cleaning the surface from the scale. A scale layer with the highest blocking properties formed under applied ultrasound intensity of 1.9 W/cm2. The ultrasound doubled crystallization rate, reduced the scale porosity 5 times and halved its area density comparing to non-sonicated conditions. Ultrasound of controllable intensity can solve both scale and corrosion problems of industrial heat-exchange equipment by forming a protective scale layer and removing excessive deposits.

    更新日期:2018-05-19
  • Sonochemical reduction of Cr(VI) in air in the presence of organic additives: what are the involved mechanistic pathways?
    Ultrason. Sonochem. (IF 4.218) Pub Date : 2018-05-18
    Jorge M. Meichtry, Mariel Slodowicz, Lucía Cancelada, Hugo Destaillats, Marta I. Litter

    The sonochemical (850 kHz) reduction of Cr(VI) (0.3 mM, pH 2, reactor open to air) was analyzed in the presence of different additives. The effects on Cr(VI) reduction efficiency of added formic acid (FA, 10 mM), citric acid (Cit, 2 mM), ethylenediaminetetraacetic acid (EDTA, 1 mM), methanol (MeOH, 0.1 M), 2-propanol (2-PrOH, 0.1 M), tert-butanol (t-BuOH, 0.1 M), phenol (PhOH, 2 mM) and sodium lauryl sulfate (SLS, 1 mM) have been evaluated in comparison with the system in the absence of additives. Complete Cr(VI) reduction was obtained only when using EDTA (at 120 min) and Cit (at 180 min). Cr(III) complexes with these compounds or with their degradation products were detected as final products. For EDTA, Cit, t-BuOH, FA and SLS, the Cr(VI) decay could be adjusted to a zero-order kinetics; in the cases of MeOH, EtOH and 2-PrOH, there was a deviation from the zero-order kinetics. The Cr(VI) conversion increased in the order SLS (very low) < no additive ≅ MeOH ≅ EtOH ≅ 2-PrOH < FA < t-BuOH < PhOH < Cit < EDTA. The role of EDTA and Cit in stabilizing intermediate Cr(V) peroxo compounds and enhancing their direct transformation into different Cr(III) species is considered a major factor in the acceleration of Cr(VI) reduction processes. Mechanistic pathways are proposed.

    更新日期:2018-05-18
  • Research on the techniques of ultrasound-assisted liquid-phase peeling, thermal oxidation peeling and acid-base chemical peeling for ultra-thin graphite carbon nitride nanosheets
    Ultrason. Sonochem. (IF 4.218) Pub Date : 2018-05-17
    Jingang Cui, Dawei Qi, Xue Wang

    Graphite phase carbon nitride (g-C3N4) composite structure materials, as a kind of stable compound with graphite-like structure, has attracted more and more attention due to its excellent properties, such as being able to absorb solar energy, stable chemical and optical properties and having a suitable oxidation potential. However, its application in the field of photocatalysis is limited by its small specific surface area and poor dispersibility. To solve this problem, ultra-thin g-C3N4 nanosheets are often prepared using peeling methods. In this paper, the current status and mechanism of thermal oxidation peeling, ultrasound-assisted liquid-phase peeling and acid-base chemical peeling are reviewed in detail. In addition, the future research directions of ultra-thin graphite-like carbon nitride nanosheets are discussed

    更新日期:2018-05-18
  • Ultrasound-assisted Oil removal of γ-Al2O3-based spent hydrodesulfurization catalyst and Microwave roasting recovery of metal Mo
    Ultrason. Sonochem. (IF 4.218) Pub Date : 2018-05-17
    Lu Wang, Liu Chao, Wenwen Qu, Shengming Xu, Libo Zhang, Jinhui Peng, Xiaolei Ye

    Currently, roasting-leaching is the main treatment process of spent hydrodesulfurization (HDS) catalyst , but it will produce impurities, such as nickel molybdate and cobalt molybdate (NiMoO4 or CoMoO4), which is adverse to recover valuable metals. In this paper, a combined ultrasonic-microwave method was developed to remove oil and recover molybdenum (Mo) from the spent HDS catalyst. Firstly, ethanol was used to extract the surface oil of the spent MoNiCo/Al2O3 catalyst with ultrasonic assistance. Effects of temperature, ultrasonic time, liquid-solid ratio and ultrasonic power on the oil removal rate were investigated systematically and the process conditions were optimized using response surface methodology (RSM). The results showed that the oil removal rate was over 99% under the optimum conditions of temperature 55 oC, ultrosonic time 2 h, liquid to solid ratio 5: 1, and ultrasonic power 600 W. After oil removal, the sample was roasted in microwave field at 500 oC for 15 min. The generation of toxic gas could be effectively avoided and no hardest-to-recycle impurity CoMoO4 was found. At last, the roasted sample was subjected to ultrasonic leaching with sodium carbonate (Na2CO3) solution for recovering Mo. Extraction of Mo of the deoiled sample after microwave roasting reached 94.3%, which is about 7% higher than that of oily sample. Moreover, microwave roasting method resulted in a much higher Mo extraction than traditional method for both the oily and deoiled spent catalyst. It was concluded that the ultrasonic-microwave assisted method could remarkably improve the recovery of Mo and greatly shorten the processing time.

    更新日期:2018-05-18
  • Research on the dispersion of carbon nanotubes by ultrasonic oscillation, surfactant and centrifugation respectively and fiscal policies for its industrial development
    Ultrason. Sonochem. (IF 4.218) Pub Date : 2018-05-17
    Yanfeng Jiang, Hao Song, Rui Xu

    Carbon nanotubes (CNTs) have attracted wide attention because of their unique structure and properties. However, the prepared CNTs often present agglomeration state, which destroys the excellent properties of single carbon nanotubes and seriously affects the application of carbon nanotubes. How to effectively disperse carbon nanotubes has become an urgent problem to be solved. There are many factors affecting the dispersion of carbon nanotubes. In this paper, the effects of three aspects of surfactant, ultrasonic oscillation and centrifugation on the dispersion of carbon nanotubes and fiscal policies for the development of Nano high-tech industry are mainly studied.

    更新日期:2018-05-18
  • Ultrasound-assisted Leaching of Cobalt and Lithium from Spent Lithium-ion Batteries
    Ultrason. Sonochem. (IF 4.218) Pub Date : 2018-05-17
    Feng Jiang, Yuqian Chen, Shaohua Ju, Qinyu Zhu, Libo Zhang, Jinhui Peng, Xuming Wang, Jan D. Miller

    Recovery of cobalt and lithium from spent Li-ion batteries (LIBs) has been studied using ultrasound-assisted leaching. The primary purpose of this work is to investigate the effects of ultrasound on leaching efficiency of cobalt and lithium. The results were compared to conventional leaching. In this study sulfuric acid was used as leaching agent in the presence of hydrogen peroxide. The cathode active materials from spent battery were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM) before and after leaching. Effects of leaching time, leaching temperature, H2SO4 concentration, H2O2 concentration, solid/liquid ratio, and ultrasonic power have been studied. Optimal leaching efficiency of 94.63% for cobalt, and 98.62% for lithium, respectively, was achieved by using 2M H2SO4 with 5% (v/v) H2O2 at a solid/liquid ratio of 100 g/L, and an ultrasonic power of 360 W, and the leaching time being 30 min under 30°C. Compared with conventional leaching, the ultrasound-assisted leaching gave a higher leaching rate and improved leaching efficiency under the same experimental conditionals. The kinetic analysis of ultrasound-assisted leaching showed that the activation energy of cobalt and lithium were 3.848 KJ/mol and 11.6348 KJ/mol, respectively, indicating that ultrasound-assisted leaching of cobalt and lithium from spent LIBs was controlled by diffusion.

    更新日期:2018-05-18
  • Ultrasound-assisted biosynthesis of novel methotrexate-conjugates
    Ultrason. Sonochem. (IF 4.218) Pub Date : 2018-05-17
    Jennifer Noro, Rui L. Reis, Artur Cavaco-Paulo, Carla Silva
    更新日期:2018-05-17
  • Use of ultrasound irradiation to inactivate Cryptosporidium parvum oocysts in effluents from municipal wastewater treatment plants
    Ultrason. Sonochem. (IF 4.218) Pub Date : 2018-05-17
    María Jesús Abeledo-Lameiro, Elvira Ares-Mazás, Hipólito Goméz-Couso
    更新日期:2018-05-17
  • Easy fabrication of poly(butyl acrylate)/silicon dioxide core-shell composite microspheres through ultrasonically initiated encapsulation emulsion polymerization
    Ultrason. Sonochem. (IF 4.218) Pub Date : 2018-05-17
    Shengwei Guo, Xin Wang, Zhiliang Gao, Guxia Wang, Min Nie

    In this study, instead of using the usual chemical methods, poly(butyl acrylate)/silicon dioxide (PBA/SiO2) core-shell composite microspheres were prepared using a physical method-ultrasonically initiated encapsulation emulsion polymerization. The morphology and particle size of the PBA/SiO2 microspheres were analysed using transmission electron microscopy (TEM) and dynamic light scattering (DLS). The encapsulation state was determined using X-ray photoelectron spectroscopy (XPS). The composition and thermogravimetric behavior were characterized using Fourier transform infrared spectroscopy (FTIR) and thermogravimetric analysis (TGA). The TEM and DLS results show that monodisperse PBA/SiO2 core-shell composite microspheres were successfully obtained. The diameter and shell thickness were 150 nm and 15 nm, respectively. The XPS and FTIR results show that there was no new chemical bond between the PBA shell and the SiO2 core. They were just combined by physical adsorption. The encapsulation efficiency of SiO2 microspheres by PBA is 8.2% through TGA. In addition, this article focuses on the formation mechanism of PBA/SiO2 core-shell microspheres prepared through ultrasonically initiated encapsulation emulsion polymerization. Intuitive observation and the results of TEM and DLS, especially the change in zeta potential, clearly indicate an encapsulation process. Thereinto, a bilayer-structure space established by appropriate amount of cetyltriethylammnonium bromide (CTAB) molecules is the key to realize ultrasonically initiated encapsulation emulsion polymerization.

    更新日期:2018-05-17
  • Bubble size measurements in different acoustic cavitation structures: filaments, clusters, and the acoustically cavitated jet
    Ultrason. Sonochem. (IF 4.218) Pub Date : 2018-05-16
    Fabian Reuter, Sergey Lesnik, Khadija Ayaz-Bustami, Gunther Brenner, Robert Mettin

    Acoustic cavitation typically forms a variety of bubble structures of generally unknown and wide size distributions. As the bubbles strongly oscillate, their (equilibrium) sizes are not directly observable. Here, a method is presented to experimentally determine the size distribution in bubble populations from high speed imaging of the bubbles in oscillation. To this end, a spherical bubble model is applied in statistical fashion. This technique is applied to several experimentally realized bubble structures: streamer filaments, clusters, and a peculiar structure we report here on, the acoustically cavitated jet. It is generated by the sonication of a submerged jet to produce abundant cavitation already at low flow velocities. Our analysis is complemented by numerical exploration of the hydrodynamic and acoustic properties of the experimental configuration in which the observed bubble structures are formed.

    更新日期:2018-05-16
  • Ultrasound-assisted synthesis of two novel [CuBr(diamine)2.H2O]Br complexes: Solvatochromism, crystal structure, physicochemical, Hirshfeld surface thermal, DNA/binding, antitumor and antibacterial activities
    Ultrason. Sonochem. (IF 4.218) Pub Date : 2018-05-12
    Ismail Warad, Firas F. Awwadi, Bahaa Abd Al-Ghani, Ashraf Sawafta, Naveen Shivalingegowda, Neartur Krishnappagowda Lokanath, Mohammad S. Mubarak, Taibi Ben Hadda, Abdelkader Zarrouk, Fuad Al-Rimawi, Abdallah Bani Odeh, Sameer A. Barghouthi

    Two new hydrated monocationic Cu(II) complexes with 1,3-propylenediamine and 1,2-ethylenediamine of general formula [CuBr(N-N)2.H2O]Br were prepared. The complexes were identified by means of several spectroscopic tools (Uv-visible, IR and MS), thermally (TG/DTA) and CHN-elemental analysis. The three dimensional structure for complex A and B was provide by X-ray diffraction studies and showed the Cu(II) ion as 4+1+1 coordinated, four nitrogen atoms of the diamine ligands, one bromide ion and one H2O semi-coordinated to the Cu(II) center, a typical trans effect is clearly observed in the two complexes. The molecular crystal structures are linked via several H-bonds like N__H...Br and N__H...O. Additionally, intra-molecular H-bonds of kind C__H....Br is observed; these interactions lead to crystal structure three dimensional architecture packing. Hirshfeld surfaces (HSA) analysis was served to figure out the inter-contacts and fingerprints atoms percentage. DNA-binding, antitumor and antibacterial effectiveness of the desired complexes were evaluated.

    更新日期:2018-05-12
  • Effects of high intensity ultrasound on the inactivation profiles of Escherichia coli K12 and Listeria innocua with salt and salt replacers
    Ultrason. Sonochem. (IF 4.218) Pub Date : 2018-05-11
    Elena S. Inguglia, Brijesh K. Tiwari, Joseph P. Kerry, Catherine M. Burgess

    This study investigated the efficacy of power ultrasound (US) for the inactivation of Escherichia coli and Listeria innocua in the presence of sodium salt and salt replacers. Inoculated bacteria suspensions were treated at ultrasonic frequencies of 33 or 20 kHz alone or in combination, and in the presence of 5% NaCl, 5% KCl or 5% NaCl/KCl. Inactivation curves were fitted to the Weibull and the Biphasic models. The goodness of the fit for each model was evaluated based on R2 and RMSE, while AIC and BIC values were used to choose the best model predictor. The Weibull and the biphasic models showed high regression coefficient (R2>0.99) and low RMSE (<0.03) values. According to the results, inactivation up to 6 log for E.coli K12 and to 4 log for L. innocua could be achieved within one hour of ultrasound treatment. However, the presence of NaCl, or its substitution with KCl did not affect the degree of inhibition for both microorganisms. The results of this study suggest that power ultrasound treatment may be employed for the inactivation of microorganisms when low salt or salt substitutes are employed.

    更新日期:2018-05-11
  • Ultrasonic pretreatment promotes diacylglycerol production from lard by lipase-catalysed glycerolysis and its physicochemical properties
    Ultrason. Sonochem. (IF 4.218) Pub Date : 2018-05-09
    Xinxin Zhao, Qinxiu Sun, Zeyu Qin, Qian Liu, Baohua Kong

    The objective of this study was to evaluate the effect of ultrasonic pretreatment on diacylglycerol (DAG) synthesis by lipase-catalysed glycerolysis of lard and to analyse the physicochemical properties of lard-based DAG. The optimal ultrasonic pretreatment conditions were: Rhizomucor miehei (Lipozyme® RMIM)-to-lard ratio 4:100 (W/W), 45 °C for 5 min, and power 250 W. The lard-based DAG samples for 4 h of glycerolysis reactions with ultrasonic pretreatment (named DAG-U) and 11 h of glycerolysis reactions without ultrasonic pretreatment (named DAG-N) had similar DAG contents and were used for further analysis. The major FA compositions and iodine value of lard, DAG-U and DAG-N were similar. Fourier transform infrared spectroscopy analysis proved that enzymatic glycerolysis with and without ultrasonic pretreatment did not change the structure of the lard. Differential scanning calorimetry analysis showed that the crystallization onset of DAG-U and DAG-N shifted to higher temperatures than that of lard, which indicated that DAG oils accelerated nucleation and crystal growth. X-ray diffraction analysis revealed that both DAG-U and DAG-N contained β′ crystal and a substantially lower amount of β crystal. Overall, ultrasonic pretreatment promotes diacylglycerol production from lard through lipase-catalysed glycerolysis, and DAG-U and DAG-N have similar physicochemical properties.

    更新日期:2018-05-09
  • A novel rapid ultrasonication-microwave treatment for total lipid extraction from wet oleaginous yeast biomass for sustainable biodiesel production
    Ultrason. Sonochem. (IF 4.218) Pub Date : 2018-05-04
    Alok Patel, Neha Arora, Vikas Pruthi, Parul A Pruthi

    Oleaginous yeasts have emerged as a sustainable source of renewable oils for liquid biofuels. However, biodiesel production from them has few constraints with respect to their cell disruption and lipid extraction techniques. The lipid extraction from oleaginous yeasts commonly includes dewatering and drying of cell biomass, which requires energy and time. The aim of this work was to establish a process for the lipid extraction techniques from wet biomass applying acid catalyzed hot water, microwave, rapid ultrasonication-microwave treatment together with conventional Bligh and Dyer method. In the wake of testing all procedures, it was revealed that rapid ultrasonication-microwave treatment has great potential to give high lipid content (70.86 % w/w) on the cell dry weight basis. The lipid profile after treatment showed the presence of appropriate quantities of saturated (10.39 ± 0.15%), monounsaturated (76.55 ± 0.19%) and polyunsaturated fatty acids (11.49 ± 0.23%) which further improves biodiesel quality compared to the rest of methods. To the best of our knowledge, this is the first report of using rapid ultrasonication-microwave treatment for the lipid extraction from wet oleaginous yeast biomass in the literature.

    更新日期:2018-05-04
  • Ultrasound or Microwave Vacuum Thawing of Red Seabream (Pagrus major) Fillets
    Ultrason. Sonochem. (IF 4.218) Pub Date : 2018-05-04
    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. MVT showed a desirable viscoelasticity of muscle proteins and UVT had a relatively stable secondary structure. There were no significant changes in free water. Thus, UVT and MVT could be used to improve the physicochemical properties of proteins during thawing of fillets.

    更新日期:2018-05-04
  • High-speed imaging of ultrasound driven cavitation bubbles in blind and through holes
    Ultrason. Sonochem. (IF 4.218) Pub Date : 2018-04-30
    Markus Kauer, Valentina Belova-Magri, Carlos Cairós, Gerd Linka, Robert Mettin

    The interest in application of ultrasonic cavitation for cleaning and surface treatment processes has increased greatly in the last decades. However, not much is known about the behavior of cavitation bubbles inside the microstructural features of the solid substrates. Here we report on an experimental study on dynamics of acoustically driven (38.5 kHz) cavitation bubbles inside the blind and through holes of PMMA plates by using high-speed imaging. Various diameters of blind (150, 200, 250 and 1000 µm) and through holes (200 and 1000 µm) were investigated. Gas bubbles are usually trapped in the holes during substrate immersion in the liquid thus preventing their complete wetting. We demonstrate that trapped gas can be successfully removed from the holes under ultrasound agitation. Besides the primary Bjerknes force and acoustic streaming, the shape oscillations of the trapped gas bubble seem to be a driving force for bubble removal out of the holes. We further discussed the bubble dynamics inside microholes for water and Cu2+ salt solution. It is found that the hole diameter and partly the type of liquid media influences the number, size and dynamics of the cavitation bubbles. The experiments also showed that a large amount of the liquid volume inside the holes can be displaced within one acoustic cycle by the expansion of the cavitation bubbles. This confirmed that ultrasound is a very effective tool to intensify liquid exchange processes, and it might significantly improve micro mixing in small structures. The investigation of the effect of ultrasound power on the bubble density distribution revealed the possibility to control the cavitation bubble distribution inside the microholes. At a high ultrasound power (31.5 W) we observed the highest bubble density at the hole entrances, while reducing the ultrasound power by a factor of ten shifted the bubble locations to the inner end of the blind holes or to the middle of the through holes.

    更新日期:2018-05-01
  • Formation of metallic silver and copper in non-aqueous media by ultrasonic radiation
    Ultrason. Sonochem. (IF 4.218) Pub Date : 2018-04-30
    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 Ag2O and Cu2O. 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. It was found that the presence of silver particles enhances the formation of metallic copper. This phenomenon was observed in the experiment with the acetate salts mixture.

    更新日期:2018-04-30
  • Energy performance evaluation of ultrasonic pretreatment of organic solid waste in a pilot-scale digester
    Ultrason. Sonochem. (IF 4.218) Pub Date : 2018-04-30
    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. OSW with 6-10 % TS was treated using a lab-scale ultrasonic processor using various power densities (0.2 - 0.6 W/mL) at different time periods up to 30 min. Results of lab scale confirmed that OSW with 6% TS sonicated with 0.2 W/mL power density in 30 min gave the best outcome for the pilot scale experiment. To simulate the condition of an actual scale, in addition to energy analysis, two different organic loading rates (OLR), namely 500 and 1500 gVS/m3day were examined. The pilot digester was fed with OSW with or without the pretreatment based on the aforementioned specifications. The results showed that UP effectively improves biogas generation in terms of quantity and quality (CH4/CO2). Furthermore, it decreases the time to reach the maximum cumulative biogas volume comparing to the untreated feed. The key achievement of this research has confirmed that although the relative increase in the energy gain by the influence of UP was more remarkable under the 500 gVS/m3day OLR, energy analysis showed a better energy gain and energy benefit as well as jumping in biogas yield up to 80% for UP treated OSW under 1500 gVS/m3day OLR..

    更新日期:2018-04-30
  • Coupling of high-intensity ultrasound and mechanical stirring for producing food emulsions at low-energy densities
    Ultrason. Sonochem. (IF 4.218) Pub Date : 2018-04-30
    Eric Keven Silva, Ana Letícia R. 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. Firstly, the action of modified starch and eugenol onto interface oil-water was evaluated. The emulsifier was rapidly adsorbed on the interface water-sunflower oil reducing the interfacial tension from 25 to 16 mN/m, while eugenol did not show surface activity. The increase of energy density, in general, resulted in droplet size reduction, indicating the relevant role of the forces involved in the droplet breakup on emulsion stability. Coupling was more efficient of the droplets breakup producing smaller droplet size with narrower size distribution. While the coupled system work during 5 min for an energy density of 583 J/mL, the corresponding emulsification time for operating singly US and RS were 7.09 min and 17.04 min, respectively. Therefore, the main advantage associate to coupled process is the reduced processing time to produce an emulsion with the better kinetic stability.

    更新日期:2018-04-30
  • Effect of ultrasound transducer design on the acoustically-assisted supercritical fluid extraction of antioxidants from oregano.
    Ultrason. Sonochem. (IF 4.218) Pub Date : 2018-04-30
    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). The highest nominal power density provided according to the calorimetric method was for T4 (151.6±7.1 W/L). The T2 produced a more uniform acoustic field and a higher acoustic pressure (150.6±20.5 kPa). Both parameters had an impact on total phenolics and antioxidants extraction with CO2 under supercritical conditions (35 MPa, 35 °C, 2.3% ethanol as co-solvent). T4 and T2 were equally efficient (4.0±0.2 and 4.2±0.2 mg GA/g) for phenolic extraction, and with respect to antioxidant capacity, the best performance was that of T4 (26.4±1.1 μmol TE/g). Of the antioxidant compounds extracted, flavones and flavanones were identified. Therefore, transducer geometry influenced the amount and distribution of energy transmitted into the medium, thus determining the efficiency of the extraction process.

    更新日期:2018-04-30
  • Ultrasonic Technology for Value Added Products from Feather Keratin
    Ultrason. Sonochem. (IF 4.218) Pub Date : 2018-04-27
    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. Sonication of feather keratin in pure ionic liquids (ILs) and a mixture containing ILs and different co-solvents was conducted under different applied acoustic power levels. It was found that ultrasonic irradiation significantly improved the rate of dissolution of feather keratin as compared to the conventional method, from about 2 hours to less than 20 minutes. The amount of ILs needed was also reduced by introducing a suitable co-solvent. The keratin was then regenerated, analyzed and characterized using various methods. This material holds the potential to be reused in various appliances.

    更新日期:2018-04-28
  • A nanocrystalline-amorphous mixed layer obtained by ultrasonic shot peening on pure titanium at room temperature
    Ultrason. Sonochem. (IF 4.218) Pub Date : 2018-04-27
    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 44.09%. Moreover, with the amorphization percentage in the NC-A mixed layer increasing, the surface hardness increased constantly. Base on the experimental results, the amorphization mechanism during USP treatment was also analyzed.

    更新日期:2018-04-27
  • A novel naphthalene carboxylic acid-based ionic liquid mixed disperser combined with ultrasonic-enhanced in-situ metathesis reaction for preconcentration of triclosan and methyltriclosan in milk and eggs
    Ultrason. Sonochem. (IF 4.218) Pub Date : 2018-04-26
    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) [C4MIM][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. Due to their strong acidity and lower solubility than traditional hydrophilic ILs, utilization of [C4MIM][NCA] in the IL-IL-DLLME procedure increased extraction recoveries (ERs) for triclosan (TCS) and methyltriclosan (MTCS) by 10-12% and also avoided an extra pH adjustment step. A series of operational parameters were optimized using single-factor screening and central composite design as follows: 65 µL extraction solvent, 150 µL [C4MIM][BF4] and [C4MIM][NCA] (132/18, v/v, μL) as dispersive solvent, 0.16 g NH4PF6 and 3.3 min ultrasonic time. Under optimized conditions with a fortification of 100 µg kg-1, ERs were 92.6-93.4% for TCS and 92.7-94.2% for MTCS in bovine milk and chicken egg samples. LODs for TCS and MTCS were 0.16-0.24 µg kg-1 and the enrichment factors were 21.8-23.1. Inter- and intra-day precisions had relative standard deviations of 3.3-5.4% for the optimized method. Overall, this newly developed IL-IL-DLLME method was effective for detecting trace levels of TCS and MTCS in real-world, animal-based foods. Prominent advantages of the new method include high precision and accuracy, high extraction efficiency, simple analytical operations, and no use of organic solvents making the procedure environmentally benign.

    更新日期:2018-04-26
  • Effect of ultrasonic irradiation on morphology and polymorphic transformation of glycine
    Ultrason. Sonochem. (IF 4.218) Pub Date : 2018-04-26
    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. According to the scanning electron microscopy (SEM) images, the ultrasound had a significant effect on the crystal morphology. The highest ultrasound power applied yielded more rounded crystals compared to the crystals prepared in the absence of ultrasound. In addition to SEM analysis, detailed crystal shape analysis was performed and shape factors, namely the circularity, elongation, and convexity values, were determined quantitatively to get more information about the morphological changes related to the variations in the size and shape of the end products. From the morphological point of view, the circularity values of the crystals obtained under ultrasound were higher but the elongation values were smaller compared to the crystals obtained in the absence of ultrasound. It was also found that higher ultrasound decreased the length and width of the crystals, and the application of ultrasound increased the aspect ratio value from 0.483 to 0.657.

    更新日期:2018-04-26
  • Ultrasonic Degradation of aqueous Phenolsulfonphthalein (PSP) in the presence of nano-Fe/H2O2
    Ultrason. Sonochem. (IF 4.218) Pub Date : 2018-04-24
    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. Experimental results demonstrated that a combined ultrasonic/nano-Fe/H2O2 system was more effective for PSP removal in combination than they were individually and there was a significant difference between the combined and single processes. The ultrasonic/nano-Fe/H2O2 degradation follows the Langmuir–Hinshelwood (L–H) kinetic model. The addition of nano-Fe and H2O2 to the ultrasonic reactor greatly accelerated the degradation of PSP (25 mg/L) from 12.5% up to 96.5%. These findings indicated that ultrasonic degradation in the presence of nano-Fe and H2O2 is a promising and efficient technique for the elimination of emerging micropollutants from aqueous solution.

    更新日期:2018-04-25
  • Effect of high intensity ultrasound pretreatment on functional and structural properties of micellar casein concentrates
    Ultrason. Sonochem. (IF 4.218) Pub Date : 2018-04-24
    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, emusifying, gelling increased significantly as the ultrasonic time prolonged, but the change of pH value were insignificant. In addition, the structural characterisics of MCC for all samples were studied. There was an increase in surface hydrophobicity (Ho) and a reduction in particle size compared with the control (without HIUS pretreatment). The secondary structure of HIUS pretreated MCC samples changed significantly with an increase in β-sheets and random coils and a reduction in α-helix and β-turn. It can be speculated that HIUS pretreatment facilitate the change of functional properties of MCC and these changes would promote its application in food industry.

    更新日期:2018-04-25
  • Cu- and -S @SnO2 nanoparticles loaded on activated carbon for efficient ultrasound assisted dispersive µSPE-spectrophotometric detection of quercetin in Nasturtium Officinale extract and fruit juice samples: CCD-RSM design
    Ultrason. Sonochem. (IF 4.218) Pub Date : 2018-04-23
    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. Under optimized conditions, the calibration graph for quercetin was linear in the range of 20 to 4000 ng mL-1; the limit of detection and quantitation were 4.35 and 14.97 ng mL-1, respectively and the enrichment factor was 95.24. Application of this method to analyze spiked extract, fruit juice and water samples resulted in acceptable recovery values ranging from 90.3% to 97.28% with intra-day and inter-day relative standard deviation values lower than 6.0% in all cases. Among the equilibrium isotherms tested, Langmuir was found to be the best fitted model with maximum sorption capacity of 39.37 mg g-1, suggesting a homogeneous mode of sorption for quercetin.

    更新日期:2018-04-25
  • Ultrasound assisted fabrication of a novel optode base on a triazine based Schiff base immobilized on TEOS for copper detection
    Ultrason. Sonochem. (IF 4.218) Pub Date : 2018-04-18
    Zohreh Parsaee, Nima Karachi, Razieh Razavi

    This work introduces novel selective and sensitive optical sensor based on a nano sized triazine based Schiff base (H2L) 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 to 1.0×10−5 mol L-1 with a low detection limit of 1.53 × 10-8 mol L-1. The optimized geometry of H2L 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. The calculated electronic properties of them including the molecular orbital, Mulliken population analysis, contour of electrostatic potential, and molecular electrostatic potential map confirmed the behavior of the sensor. Some advantage of the fabricated sensor such as high selectivity, sensitivity, short response time, easy production, fast regeneration, low cost, being portable and user friendly can make it a good choice to detection of Cu(II) ion in various application. The suggested sensor was revealed excellent sensitivity in the natural samples that confirmed by Inductively Coupled Plasma-Mass (ICP) spectrometry method.

    更新日期:2018-04-25
  • Effects of ultrasonic assisted cooking on the chemical profiles of taste and flavor of spiced beef
    Ultrason. Sonochem. (IF 4.218) Pub Date : 2018-04-10
    Yunhe Zou, Dacheng Kang, Rui Liu, Jun Qi, Guanghong Zhou, Wangang Zhang

    The objective of this study was to assess the effects of ultrasonic assisted cooking on the chemical profiles of spiced beef taste and flavor. Ultrasound power with 0 W, 400 W, 600 W, 800 W and 1000 W (frequency of 20 kHz) were used for cooking 120 min. The sodium chloride, sugar, free amino acids (FAAs), 5′-ribonucleotides, lipid oxidation, volatile flavor substance contents and electronic nose of spiced beef were determined. Results showed that ultrasonic treatment could significantly increase the content of sodium chloride in beef sample (P<0.05). When the ultrasonic power lower than 1000 W, the content of sugar and 5′-ribonucleotides could be increased significantly compared with the control (P<0.05). The essential amino acid content and the essential amino acid/non-essential ratios (E/NE) were significantly increased with the ultrasound treatment (P<0.05). The lipid oxidation showed that ultrasound resulted in the increased of TBARS values compared with control significantly (P<0.05), but no significant differences were shown among the different ultrasonic power groups (P>0.05). With the ultrasonic treatment, the types and relative content of volatile flavor substances were significantly increased (P<0.05), especially for aldehydes, alcohols and ketones. However, there was no significant variation among the different ultrasound power groups (P>0.05). This result was consistent with the measurement of electronic nose. Data points of control samples were away from ultrasonic treatment groups, while data points of different ultrasonic treatment groups were flock together. The results indicate that the application of ultrasound during cooking has a positive effect on chemical profiles of spiced beef taste and flavor, particularly for the power of 800 W.

    更新日期:2018-04-10
  • Ultrasound assisted facile synthesis of Mn(II) and Cu(II) coordination polymers and their use as precursors for α-Mn3O4 and CuO nanoparticles: synthesis, characterization and catalytic properties
    Ultrason. Sonochem. (IF 4.218) Pub Date : 2018-04-09
    Mohamed I. Said, Asma I. El-Said, Aref A.M. Aly, Asia Abou-Taleb

    A self-assembly of pyridine-2,6-dicarboxylate with Cu(II) and Mn(II) under ultrasonic and microwave irradiation gave the two coordination polymers [Cu(PDA)(H2O)1.5]n (1) and [Mn(PDA)(H2O)1.5]n (2). Their structures were characterized using IR, elemental analysis, X-ray diffraction (XRD) and spectroscopic methods. The corresponding α-Mn3O4 and CuO nanoparticles were synthesized by calcination of 1 and 2 in air at 600 °C. Transmission electron microscopy (TEM) reveals a sphere-like morphology for the Mn3O4 nanoparticles. Shrinkage of the particle size from 90 nm (by conventional synthesis of the precursor) to 19 nm (ultrasonic-assisted) takes place, indicating the great effect of ultrasonication. CuO nanoparticles were of semispherical (conventional and ultrasonic-assisted methods) and hexagonal shapes (microwave irradiation) with an average diameter of 7, 15 and 25 nm, respectively. The catalytic performance of the coordination polymers towards degradation of methylene blue and methyl orange in the presence of hydrogen peroxide was studied. Using the same dose, catalyst 1 proved to be more efficient in color removal of both MB and MO than catalyst 2 did. Recycling test for 2 showed that it is a recyclable catalyst with no structural changes over three recycling experiments.

    更新日期:2018-04-10
Some contents have been Reproduced with permission of the American Chemical Society.
Some contents have been Reproduced by permission of The Royal Society of Chemistry.
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