Ultrasonic Duty Cycle Research Articles

Application of ultrasonication and PEGylation as green extraction technology for yield intensification of diallyl thiosulfinate (allicin)

The numerous advantages of bioactive phytochemicals like Diallyl thiosulfinate (DATS) or allicin on human health have attracted scientific inventions and innovations in the latest years for the application in formulating dietary supplements, food products and medicines. In order to maximize the extraction of the phytodrug DATS from Allium sativum, an indigenous approach was devised that relies on the hybrid application of ultrasonication and self-aggregation property of nonionic polymers. Under the optimal conditions of several process parameters (including solvent to garlic biomass ratio, ultrasonic amplitude, ultrasonic duty cycle, ultrasonication time), optimal efficiency of DATS extraction was achieved (3.67 mg/g of garlic biomass). From the two-way ANOVA analysis, ultrasound amplitude was found most significant parameter. Additionally, this proposed approach was able to enhance ∼2.67 fold yield of DATS with significantly lower electric power consumption than the conventional technique. Moreover, polyethylene glycol based pH responsive self-assembly carrier system was prepared which helped to maintain a 94% concentration of DATS for around 30 days and reduced the concentration loss of DATS because of molecular degradation. This hybrid extraction-stabilization method can be beneficial for the industrial application of DATS extraction because its bioactivity was well preserved as observed from the in vitro antibacterial experiment.

Use of mesoporous BiOI microspheres for sonocatalytic degradation of tetracycline hydrochloride

Self-assembled mesoporous BiOI microsphere with nanosheets were prepared by a solvothermal method and used as sonocatalysts. The sonocatalytic performances of the BiOI microspheres were evaluated in terms of the degradation rate of tetracycline hydrochloride (TCH) as a model pollutant. We designed three comparative experiments to explore the degradation of TCH solution under natural light, namely with sonication, with BiOI alone, and with ultrasound (US)/BiOI synergy. The degradation rate of TCH with US/BiOI synergy was 227 times higher than that achieved with sonication and 83 times higher than that achieved with BiOI alone. The maximum TCH degradation rate was 93.0%. The synergistic effect was therefore significant, and the synergy factor was estimated to be 61. Many factors such as the ultrasonic duty cycle, applied power, catalyst concentration, and initial TCH dye concentration may affect the ultrasonic degradation efficiency. Box–Behnken design of the response surface method were used to optimize the parameters and to study the effects of the catalyst concentration, ultrasonic duty cycle, and applied power. Analysis of variance confirmed that the quadratic response surface model for predicting the sonocatalytic efficiency was good for the corresponding parameters (R2 = 0.9936 and adjusted R2 = 0.9854). The optimization results were verified by replicate experiments. The high TCH degradation rate may be related to the generation of reactive oxygen species at the end of cavitation bubble collapse, which can improve the chemical yields.

Study on Sonocatalytic Degradation of Tetracycline Hydrochloride by Mesoporous BiOI Microspherical Under Ultrasonic Irradiation

Degradation of tetracycline hydrochloride (TCH) was carried out using natural light driven BiOI photocatalyst through sonophotocatalytic technique. Sonocatalytic degradation was considered as a new and advanced strategy for the elimination of hazardous organic pollutants from wastewater. Until now, the synergy of employing ultrasonic irradiation with BiOI based on catalysts for the removal of antibiotic residues is rarely reported. BiOI was an excellent semiconductor catalyst of Bi class. In this paper, mesoporous BiOI microspheres self-assembled from nanosheets were prepared by solvothermal method and its ultrasonic catalytic performance was studied. The sonocatalytic performance of BiOI was evaluated in terms of the degradation of tetracycline hydrochloride (TCH) as a simulate pollutant under ultrasonic irradiation. Three comparative experiments were designed to explore the degradation of TCH in natural light as follows: ultrasound alone, BiOI alone and ultrasound/BiOI synergy. The degradation rate of TCH by ultrasound/BiOI synergy was 227 times higher than that catalyzed by ultrasound alone and 83 times higher than that catalyzed by BiOI, and the maximum degradation ratio of TCH could reach to 93.0%. Therefore, the synergistic effect was significant, and the value of synergy factor was estimated as 61. Many factors, such as the ultrasonic power, catalyst concentration (Ccatalytic), ultrasonic duty cycle, concentration of initial TCH dye (CTCH), could affect the ultrasonic degradation efficiency. The BBD methodology with RSM was applied for modeling, optimization and investigation of influence of operational parameters, i.e. ultrasonic power, catalyst concentration, ultrasonic duty cycle. Analysis of variance (ANOVA) confirmed a good quadratic response surface model for predicting the sonocatalytic efficiency at various operational parameters (R2= 0.9936 and Adjusted R2=0.9854. The possible mechanism of the high degradation rate of TCH might be associated with the generation of reactive oxygen species (ROS) which could improve the chemistry yields.

Experimental investigation of effect of ultrasonic duty cycle on generation of reactive oxygen species for highly efficient sonodynamic treatment

Sonodynamic treatment (SDT) is a non-invasive treatment of cancer, combining ultrasound, reactive oxygen species (ROS), and sonosensitizer. When cavitation bubbles generated by ultrasound oscillate and collapse, ROS are generated due to the high temperature and high pressure inside the bubble. By generating cavitation bubbles in a target tissue, it can be treated by the cytotoxicity of ROS, which can be further enhanced by a sonosensitizer. In SDT, the small treatment region by a single shot of HIFU results in a long treatment time, which needs to be reduced by improving the efficiency of ROS generation. ROS can be visualized by the sonochemiluminescence of luminol. In this study, a polyacrylamide gel soaked with luminol solution is used as a target of ultrasonic exposure. The effect of the duty cycle of HIFU exposure on ROS generation was investigated by capturing sonochemiluminescent light emission, and high-speed photography of cavitation bubbles.

Investigation of ultrasound-assisted KOH and CaO catalyzed transesterification for biodiesel production from waste cotton-seed cooking oil: Process optimization and conversion rate evaluation

Development of Ultrasound (US)-assisted biodiesel production from Waste Cotton-seed Cooking Oil (WCCO) is gaining importance due to significantly lower reaction time and high energy-efficiency. In the present novel work, a comprehensive experimental study for KOH and CaO catalyzed transesterification process with detailed process optimization was performed. Kinetic modeling, scalability and energy analysis were performed to confirm the relative importance of US compared to Mechanical Stirring (MS). The optimized process parameters for KOH and CaO catalyst conditions were determined as methanol/oil molar proportion: 6.1:1 and 10.9:1, catalyst amount (w/w) %: 0.46 % and 0.96 %, reaction temperature: 53.2 °C and 48.3 °C, and the corresponding yield: 97.76 % ± 0.03 and 96.16 % ± 0.03 respectively. Box-Behnken model exhibits a significant correlation with experimental results in case of KOH (R2 = 0.98) and CaO (R2 = 0.97) catalyzed conditions. Triglyceride conversion follows pseudo-first-order reaction kinetics. The activation energy calculated for KOH and CaO catalyzed conditions was 21.36 and 33.83 kJ/mol respectively, which is 1.5 – 1.7 times lower as compared to MS process. Energy analysis showed that dissipated energy in US process is higher compared to MS. The scalability effect (with tenfold batch size), and ultrasonic duty cycle analysis showed that the continuous sonication is more effective in comparison to pulse mode. Physicochemical properties of produced biodiesel were observed in accordance with fuel specification as prescribed by ASTM D6751. Outcomes of this study are useful for development of energy-efficient US-assisted biodiesel production process on industrial scale.

Optimization of ultrasonic-assisted extraction of bioactive compounds from Nepeta (Nepeta binaludensis Jamzad)

Ultrasonication technology was utilized for extraction of effective components from Nepeta (Nepeta binaludensis Jamzad). Response surface methodology was employed in order for investigation the effects of independent process variables (ultrasonic extraction time (UET, min): 5, 10 and 15 min, ultrasound amplitude (UA, %): 20, 60 and 100%, ultrasonic extraction temperature (UEC, °C): 25, 35 and 45 °C and ultrasonic duty cycle (UDC, %): 20, 60 and 100%) on the yield (Y), total phenolic compounds (TPC), half maximal of radical (1,1-diphenyl-2-picryl hydrazyl, DPPH) scavenging activity (IC50) and ferric reducing-antioxidant power (FRAP) of ethanolic Nepeta extract. According to Derringer’s desired function approach, the optimal conditions based on both individual and combinations of all process variables were UET 15 min, UA 60%, UEC 25 °C and UDC 60%. At this optimum condition, the Y, TPC, IC50 and FRAP of the ultrasound-assisted extract (USx) were found to 10.93%, 402.63 mg GA/kg, 0.33 mg/mL and 2838.34 µmol Fe2+/kg, respectively which were well matched with the predicted values. The evaluation of antioxidant activity (IC50 and FRAP) indicates that the phenolic compounds from Nepeta possess significant antioxidant activity. Also, HPLC analysis revealed that at optimal condition of UAE, the quantity of caffeic acid (85.71%), rutin (3550%) and rosemarinic acid (468.62%) in extract increased in comparison with conventional method (solvent extraction).

A facile way for sugar transformation catalyzed by carbon-based Lewis-Brønsted solid acid

In this work, catalytic transformation of sugar into 2-Formyl-5-ethoxymethylfuran (EMF) was studied using Zn-trapped sulfonated carbon (SO3H-Zn-SC) catalyst. The catalyst was easily prepared via impregnation-pyrolysis and sulfonation. The physical and chemical properties of as-prepared catalyst were tested and discussed in details. For upgrading experiment, EMF synthesis from glucose transformation via isomerization, dehydration and etherification processes was performed using ultrasonic system. The increasing of ultrasonic power and ultrasonic duty cycle promoted the formation of EMF product, providing a maximum EMF yield of 97.8%. The ultrasonic application promoted the selectivity for EMF formation at shorter-faster reaction rate. Moreover, SO3H-Zn-SC also exhibited good reusability with low amount of acid leaching in each cycle. This research provided alternative way for improving the yield of EMF at short reaction time.

3P5-8 Experimental Investigation of Effect of Ultrasonic Duty Cycle on Generation of Reactive Oxygen Species for Highly Efficient Sonodynamic Treatment

3P5-8 Experimental Investigation of Effect of Ultrasonic Duty Cycle on Generation of Reactive Oxygen Species for Highly Efficient Sonodynamic Treatment

In vitro and ex vivo delivery of tailored siRNA-nanoliposomes for E2F1 silencing as a potential therapy for colorectal cancer

Tailored developed nanoliposomes loaded with a siRNA against the transcription factor E2F1 (siE2F1), were produced and delivered to human colorectal adenocarcinoma cell lines and to intestinal human biopsies. siE2F1 loaded nanoliposomes were produced through a dedicated ultrasound assisted technique producing particles with about 40nm size (Small Unilamellar Vesicles, SUVs) and 100% siRNA encapsulation efficiency. Compared to other production methods, the one proposed here can easily produce particles in the nanometric scale by suitable ultrasonic duty cycle treatments. Furthermore, SUVs have a high degree of size homogeneity, a relevant feature for uniform delivery behaviour.siE2F1-loaded SUVs demonstrated a very low cytotoxicity in cells when compared to a commercial transfection agent. Moreover, SUVs loaded with siE2F1 were effective in the down regulation of the target in cultured colon carcinoma cells and in the consequent reduction of cell growth. Finally, a remarkable uptake and target silencing efficiencies were observed in cultured human biopsy of colonic mucosa. In conclusion, whereas further studies in more complex models are required, the siE2F1-SUVs generated have the potential to contribute to the development of novel effective inflammatory bowel diseases-associated colorectal cancer therapies for a future personalized medicine.

Evaluation of critical parameters for preparation of stable clove oil nanoemulsion

In this work, the effects of various factors, including the ultrasonic duty cycle and intensity of ultrasonic irradiation, ultrasonication and clove oil content in production of clove oil nanoemulsion were investigated. In preparation of nanoemulsion Tween® 80/Span® 80 as nonionic surfactants via ultrasonic emulsification method was used. The average droplets size of clove oil nanoemulsion decreased with an increase in duty cycle; whereas pulsed ultrasound with proper intervals was more efficient than continuous ultrasonication. In order to replace the use of organic solvent and increase the dispersity of active ingredient, suitable emulsifiers were used. The nanopesticides made by ultrasound at optimum formula conditions were defined at ultrasonication time of 300s, surfactants concentration of 5wt%, hydrophilic–lipophilic balance number of 9, duty cycle 0.75% and ultrasonic intensity 208W/cm2. The stability of droplets size of nanoemulsions for duration of 6months was evaluated. Stable nanoemulsion clove oil with 10wt% of clove oil content was formulated at optimum conditions with average droplets size around 43nm at the beginning and after 6months nanoemulsions re-sized and it was around 100nm. A stable nanoemulsion of clove oil in water with suitable droplets size as a nanopesticide was prepared.