Ultrasonic Time Research Articles

Effect of physical field-assisted freezing on the quality attributes of frozen baked sweet potato and its optimization

Freezing plays a crucial role in ensuring the safety of foods over long storage periods. However, ice crystals within the cells can cause irreversible damages to tissue structures during the freezing process, resulting a significant problem on the quality. The present study aimed to investigate the effects of physical field-assisted freezing on the quality attributes of frozen baked sweet potato and identify the optimum operational parameters of quick-frozen process. Combination of magnetic field and ultrasound suggested the best results, with a 58.33% reduction in freezing time, 59.63% reduction in thawing loss, compared to IF. The hardness and the signal values of Sweetness and W2W of CF were 58.90%, 20.03%, and 27.07% higher than those of IF, which showed that CF have better maintenance of sample quality. Low field-nuclear magnetic resonance results showed that CF caused a decrease in the proportion of free water and an increase in the proportion of immobile water, and the water status are more similar to FB. Microscopic observations confirmed that the CF had the smallest and the most evenly distribution of ice crystals. Optimization of frozen baked sweet potato via response surface methodology, which revealed that the optimal conditions included a magnetic field intensity of 30 mT, an ultrasonic intensity of 320 W, and an ultrasonic time of 10 s. Therefore, treatment of combination with magnetic field and ultrasound is a promising novel method to improve the quality of frozen foods.

Application of machine learning in ultrasonic pretreatment of sewage sludge: Prediction and optimization

In this research, typical industrial scenarios were analyzed optimized by machine learning algorithms, which fills the gap of massive data and industrial requirements in ultrasonic sludge treatment. Principal component analysis showed that the ultrasonic density and ultrasonic time were positively correlated with soluble chemical oxygen demand (SCOD), total nitrogen (TN), and total phosphorus (TP). Within five machine learning models, the best model for SCOD prediction was XG-boost (R2 = 0.855), while RF was the best for TN and TP (R2 = 0.974 and 0.957, respectively). In addition, SHAP indicated that the importance feature for SCOD, TN, and TP was ultrasonic time, and sludge concentration, respectively. Finally, the typical industrial scenario of ultrasonic pretreatment of sludge was analyzed. In the secondary sludge, treatment volume at 0.6 L, the pH at 7.0, and the ultrasonic time at 20 min was best to improve the SCOD. In the ultrasonic pretreatment primary sludge, treatment volume of 0.3 L, pH of 7.0, and ultrasonic time of 15 min was best to improve the SCOD. Furthermore, the ultrasonic power at 700 W and ultrasonic time at 20 min were best to improve the C/N and C/P in the secondary sludge. In the primary sludge, the ultrasonic power at 600 W, and the ultrasonic time at 15 min were best to improve C/N and C/P. This study lays a foundation for the practical application of ultrasonic pretreatment of sludge and provides basic information for typical industrial scenarios.

Optimization of the preparation process of Spirulina blended liquor and Spirulina fermented wine, analysis of volatile components and in vitro antioxidant study.

The optimal conditions were explored for the preparation of Spirulina blended liquor (SBL) and Spirulina fermented wine (SFW), respectively. The parameters obtaining highest alga polysaccharide were calculated by response surface methodology. The optimal conditions for SBL preparation were base liquor of 42%vol, ultrasonication time of 37-min and ultrasonic power of 80W with polysaccharide content (PC) and alcohol content (AC) of 0.2181g/L and 39.7%vol, respectively. In the case of SFW, optimum fermentation occurred at 22°C, with a 4% inoculum and 6-day period with PC and AC of 8.533g/L and 11.2%vol, respectively. Headspace solid-phase microextraction-gas chromatography-mass spectrometry was used to quantitatively analyze the volatile components of SBL and SFW. There were 32 and 40 main aroma compounds in SBL and SFW, respectively. Volatile organic compounds, including α-ionone and β-ionone, produced by Spirulina were detected in both SBL and SFW. Comparative evaluation of scavenging activity and total reducing power revealed the antioxidant capacity of SFW significantly outperformed that of SBL.

Ultrasound-assisted extraction of scopolamine and hyoscyamine from Hyoscyamus niger roots using central compost design

Hyoscyamus niger is an important medicinal plant used in medicine and contains tropane alkaloid compounds such as hyoscyamine and scopolamine. In this study, after the selection of the solvent for extracting hyoscyamine and scopolamine, the central composite design of the response surface methodology was used to study the effect of solvent concentrations (0, 25, 50, 75, and 100 %), temperatures (25, 30, 35, 40, and 45 °C) and ultrasonication times (10, 20, 30, 40, and 50 min). The hyoscyamine and scopolamine content were obtained by HPLC-DAD. The results indicated that the predicted optimal condition for hyoscyamine and scopolamine extraction from H. niger root was as follows. Hyoscyamine: 100 % methanol, temperature 45 °C and ultrasonication time 10 min, obtained 172.06 μg/g dry weight; and scopolamine: 98.50 % methanol, temperature 25 °C and ultrasonication time 10 min, provided 229.48 μg/g dry weight. To confirm the predicted extraction conditions, a separate experiment was conducted, and the results showed that the hyoscyamine and scopolamine contents were 164.72 and 209.23 μg/g dry weight, respectively.

Optimization of Eugenol Extraction From Piper betle Leaves Using Natural Deep Eutectic Solvents and Ultrasound‐Assisted Extraction

ABSTRACTPiper betle L. (Piperaceae) is a herbal plant used in Thai traditional medicine for its antifungal and antiallergic properties, particularly through topical application. This study aimed to optimize the extraction of Piper betle leaves using natural deep eutectic solvents to enhance the extraction efficiency of eugenol, the active compound in Piper betle leaves. Various types of hydrogen bond donors—including glycolic acid, lactic acid, malic acid, tartaric acid, ascorbic acid, and citric acid—were combined with a hydrogen bond acceptor, choline chloride, to prepare natural deep eutectic solvents. The results indicated that lactic acid was the most effective hydrogen bond donor for eugenol extraction. Subsequently, the choline chloride:lactic acid molar ratios, the natural deep eutectic solvent:water mass ratios, and ultrasonication times were varied. Results showed that the optimal conditions based on one‐factor‐at‐a‐time approach were a choline chloride:lactic acid molar ratio of 1:5, a natural deep eutectic solvent:water mass ratio of 2:1, and an ultrasonication time of 30 min. Under these conditions, the eugenol concentration reached 457.22 ± 21.68 µg/mL, compared to 224.76 ± 6.99 µg/mL when ethanol was used. In conclusion, this study successfully optimized the extraction of eugenol from Piper betle leaves using natural deep eutectic solvents. These findings suggest that natural deep eutectic solvents could be a more effective solvent for the extraction of eugenol.

Use of molybdenum as a pressure calibrant in a cubic press and sound velocity measurement of tungsten to 5 GPa

ABSTRACT The pressure limit of the conventional cubic press is normally below 6 GPa, and the suitable pressure calibrant of the fixed-point method is scarce. In this study, we developed a new method for pressure determination using an acoustic travel time approach. Based on the reported ultrasonic travel times of polycrystalline molybdenum under high pressure in literature, an acoustic gauge of polycrystalline molybdenum was derived. The shear wave travel times of molybdenum were measured at high pressures and utilized for the pressure calibration in a cubic press. The pressures derived from this new travel time method are in excellent agreement with those from the fixed-point method. Subsequent compressional and shear wave velocities of polycrystalline tungsten were measured up to about 5 GPa at room temperature to further verify this method. This travel time method for pressure calibration is valuable for the sound velocity measurement of other materials in an offline laboratory.

Pengaruh Waktu Iradiasi Ultrasonik dengan Aktivasi Kalium Hidroksida terhadap Sifat Fisis Karbon Aktif dari Serbuk Karet End Life Tire

Processing End Life Tire (ELT) rubber powder into activated carbon is an alternative for handling tire waste. One way to improve physical properties such as proximate characteristics, surface area and pore diameter of activated carbon is through chemical activation assisted by ultrasonic irradiation. This research aims to determine the effect of ultrasonic irradiation time with potassium hydroxide (KOH) activation on the quality of ELT rubber activated carbon. Activated carbon was synthesized and activated using 30% KOH at various ultrasonic irradiation times, namely 0 minutes, 15 minutes, 30 minutes, 45 minutes and 60 minutes. Based on the characterization results, activated carbon with an ultrasonic irradiation time of 30 minutes is the active carbon that has the most superior properties. The proximate characteristics of activated carbon meet the active carbon quality requirements of SNI 06–3730–1995 and have the highest surface area, namely 401.11 m2/g and pore diameter of 2.1652 nm, which is included in the mesoporous structure category so that it has the potential to be applied as an adsorbent for heavy metals from contaminated fluid.

Enhancement of extraction efficiency and functional properties of chickpea protein isolate using pulsed electric field combined with ultrasound treatment

Chickpea protein isolate (CPI) is a promising dietary protein with the advantages of low allergenicity, easy digestion and balanced composition of essential amino acids. However, due to the thick skin of chickpeas, the extraction of CPI is challenging, resulting in lower efficiency of the alkaline extraction-isoelectric precipitation (AE-IEP) method. Therefore, the present study investigated the effect of pulsed electric field combined with ultrasound (PEF-US) treatment on the extraction efficiency of CPI and the functional properties was characterized. Parameter optimization was carried out using response surface methodology (RSM), with the following optimized conditions: pulse duration of 87 s, electric field intensity of 0.9 kV/cm, ultrasonic time of 15 min, and ultrasonic power of 325 W. Under the optimized conditions, the yield of CPI after combined (PEF-US) treatment was 13.52 ± 0.13 %, which was a 47.28 % improvement over the AE-IEP method. This yield was better than that obtained with either individual PEF or US treatment. Additionally, the functional properties (solubility, emulsification, and foaming) of CPI were significantly enhanced compared to AE-IEP. However, the stability of emulsification and foaming did not show significant differences among the four methods. The PEF-US method efficiently extracts CPI with excellent functional properties, enabling the production of proteins as desired functional additives in the food industry.

Ultrasonic-assisted extraction of nanocellulose from sweet potato residue and its application in noodles.

Enhancing the amount of dietary fiber without compromising the quality of noodles remains a challenge in the food industry. This study aimed to optimize the ultrasound-assisted extraction parameters to enhance the yield of nanocellulose from sweet potato residue (SPR) using a response surface methodology. The impact of SPR nanocellulose on noodles' physicochemical properties was also explored. Results showed that the optimal extraction conditions for nanocellulose from SPR were identified as 180.73 U/mL cellulase concentration, 4.28 h ultrasonic time, 444.12 W ultrasonic power, and 14.17 h enzymatic hydrolysis time. The max yield of nanocellulose was 15.93% at optimum extraction conditions. Increasing the amount of SPR nanocellulose resulted in a reduction in the optimal cooking time, water absorption, elongation index, and springiness, as well as an increase in the breaking rate, cooking loss, hardness, gumminess, and chewiness of the noodles. Sensory analysis revealed higher acceptability of the noodles with 6%-12% SPR nanocellulose compared to other treatments. Microstructure demonstrated that noodles with 0%-18% SPR nanocellulose exhibited fewer holes and denser network structures, but higher SPR nanocellulose damaged the protein network. Those findings suggested that noodles with less than 12% SPR nanocellulose exhibited higher quality. This research provided the foundation for the development of nanocellulose-enriched foods.

Ultrasonic-Assisted Biphasic Aqueous Extraction of Polyphenols from Vaccinium Dunalianum Leaves: Optimization, Antioxidant, and Tyrosinase Inhibition Activities.

To optimize the ultrasonic-assisted biphasic aqueous extraction conditions for polyphenolic compounds from Vaccinium dunalianum Wight leaves and investigate their antioxidant and tyrosinase inhibition activities, single-factor experiments were conducted to investigate the effects of ethanol volume fraction (%), ammonium sulfate mass fraction (%), solid-liquid ratio (g/mL), ultrasonic temperature (°C), and ultrasonic time (min) on polyphenolic content during extraction. Based on these experiments, three key factors influencing extraction were selected for response surface methodology (RSM) optimization. The results indicated that under conditions of 26 % ethanol, 20 % ammonium sulfate, a solid-liquid ratio of 1 : 30, and extraction for 35 minutes at 50 °C, the polyphenol content reached 61.62 mg/g. The relative contents of 6'-O-caffeoylarbutin, β-arbutin, and chlorogenic acid were 34.45 %, 4.56 %, and 31.06 %, respectively. The DPPH⋅ and ABTS+⋅ scavenging rates were above 95 % and 96 %, respectively, and the ferric reducing ability exhibited a significant dose-effect relationship. The inhibition rates of monophenolase and diphenolase activities of tyrosinase were 43.84 % and 35.73 %, respectively. The optimized process for ultrasonic-assisted biphasic aqueous extraction of polyphenols from Vaccinium dunalianum Wight leaves demonstrated significant antioxidant and tyrosinase inhibition activities.

Kinetic and optimization study of ultrasound-assisted biodiesel production from waste coconut scum oil using porous CoFe2O4@sulfonated graphene oxide magnetic nanocatalysts: CI engine approach

In this study, CoFe2O4@sulfonated graphene oxide (SGO) heterogeneous nanocatalyst was synthesized and utilized to produce biodiesel from waste coconut scum oil (WCSO). The structural features of CoFe2O4@SGO nanocatalyst were evaluated by SEM, TEM, EDX, FTIR, XRD, CO2/TPD, VSM, and BET analyses. According to these analyses, CoFe2O4@SGO nanocatalyst has high specific surface area, suitable functional groups, and good reactivity. The highest biodiesel yield using CoFe2O4@SGO nanocatalyst in optimal conditions (MeOH/WCSO ratio = 12.41, temperature = 64.73 °C, catalyst concentration = 2.24 %, and ultrasonic time = 33.08 min) was 96.87 %. The yield of biodiesel decreased from 96.91 % to 90.17 % after six reuse cycles, which demonstrates the significant stability of CoFe2O4@SGO nanocatalyst in the transesterification process. After 7 reuse steps, XRD and CO2/TPD analyzes revealed that the catalytic activity and crystallinity of the nanocatalyst were almost retained. The kinetic behavior of biodiesel generation showed that the transesterification reaction is endothermic. Enhancing the concentration of biodiesel in the fuel mix had a positive impact on the reduction of CO and UHC emissions, as well as diesel engine parameters such as cylinder pressure, BP, EGT, BSFC, and BTE. Owing to the high biodiesel yield, significant reusability, and positive impacts on the diesel engine, CoFe2O4@SGO nanocatalyst is recommended for industrial applications.

Optimum ultrasonication duration for effective antimicrobial activity of Ti3C2-MXene

The characteristics of two-dimensional (2D) nanomaterials have attracted remarkable attention, particularly in the fields of environmental engineering, sciences and medicine. This study was focused on Ti3C2Tx-MXene, a novel 2D nanomaterial known for its antibacterial efficacy against both Gram-negative and Gram-positive bacteria. Our investigation has represented the initial exploration of the primary antifungal capabilities of Ti3C2Tx-MXene nanosheets, with variations in lateral size induced by ultrasonication time. The Ti3C2-MXene, characterized by negative surface potential, was tested against Staphylococcus aureus, Escherichia coli, Klebsiella pneumonia, Enterobacter cloacae and fungal strains of Candida albicans. Ultrasonication was employed without the use of any chemical intercalant for delamination, separation, and exfoliation. The optimal ultrasonication duration was determined, revealing the minimum inhibitory concentrations of 8 μl/mL and 4 μl/mL against E. coli and S. aureus, respectively, as observed through the broth dilution test. The antifungal activity against Candida albicans has been assessed using the well diffusion method, revealing a substantial zone of inhibition measuring 14 mm. The demonstrated antimicrobial efficacy of ultrasonicated MXene sheets has shown a huge potential for serving as an effective anti-biofouling material.

A nanomodified-ultrasonic method to improve the shear strength of adhesively bonded composite joints

Adhesive bonding method has become prevalent in joining composite structures in the aerospace and automotive industries. The bonding quality is critical in terms of service safety. This research proposed a nanomodified-ultrasonic method to enhance the shear strength of adhesively composite joints. Functional multi-walled carbon nanotubes (MWCNTs) were dispersed into the adhesive, followed by the ultrasonic vibration during the bonding process. Orthogonal experiments considering different combinations of the NWCNT concentrations, ultrasonic power, and ultrasonic time were conducted to investigate the effect of different factors and to obtain the optimal processing parameters. Results indicate that the nanomodified-ultrasonic method is beneficial to the composite bonded joint and a maximum increase of 75.1% in shear strength was achieved. Furthermore, the bondline before testing and fracture surface were critically analyzed to illustrate the enhancement mechanisms.

Combining Ultra-Turrax and ultrasonic homogenization to achieve higher vitamin E encapsulation efficiency in spray drying

Vitamin E, a soluble antioxidant widely used in the food and pharmaceutical industries, is rich in tocopherols and phytosterols. Since vitamin E molecules are highly sensitive to oxidation, encapsulation is a viable and effective technique for preservation of the properties of Vitamin E and improving its stability during storage, maintaining the nutritional value. In this work, the aim was to encapsulate concentrated vitamin E using a combination of Ultra-Turrax and ultrasonication to achieve higher encapsulation efficiency in spray drying. In the first stage, the vitamin E oil was encapsulated employing only Ultra-Turrax homogenization, with subsequent optimization of spray drying. The coating materials used were maltodextrin and whey protein isolate. Optimization of the spray drying step evaluated the effects of the drying air temperature (T) and the feed flow rate (Q), to obtain better yields and a high-quality product. In the second stage, the use of ultrasonication in an additional homogenization step was evaluated, aiming to further improve the encapsulation process. The results showed that the best drying conditions (first stage) were T = 180 °C and Q = 0.6 L/h, which provided the highest yield (67.73%) and high encapsulation efficiency (73.73%). The microspheres produced had similar properties, with mean diameters ranging from 0.64 to 12.99 μm. In the second stage of the investigation, the application of ultrasonication immediately after the Ultra-Turrax homogenization enabled the encapsulation efficiency to be increased to 94.05%, with a yield of 57.54%, using an ultrasonication time of only 7 min. This showed that addition of the ultrasonic homogenization step to the process greatly improved the encapsulation efficiency and could be used to produce vitamin E-enriched powder microcapsules by spray drying, with application in the food industry.

Ultrasound assisted enzymatic synthesis of OPO structured lipids by covalent organic framework immobilized lipase

In this study, the covalent organic framework immobilized Rhizomucor miehie lipase COF@RML as a novel biocatalyst was applied in the enzymatic synthesis of OPO structured lipids (1, 3-dioleoyl-2-palmitoylglycerol). The impact of reaction medium, substrate molar ratio, enzyme addition amount, reaction time and temperature on the enzymatic synthesis of OPO structured lipids were studied. Furthermore, the effects of ultrasonic power and ultrasonic time on the synthesis of OPO structural lipids were studied. The results showed that ultrasonication could increase the yeild of OPO structured lipids by improving substrate mass transfer and enzyme particle dispersion. The optimal process for the synthesis of OPO structured lipids was obtained. When the ultrasonic power was set at 90 W, ultrasonic time at 12 minutes, enzyme addition amount at 10 wt%, substrate molar ratio at 1:8, reaction temperature at 45 °C, and reaction time at 6 hours, the yield of OPO structured lipids reached a remarkable 51.27 %. Finally, the commercial lipase Lipozyme RM IM was compared with the COF@RML. The findings indicated that COF@RML immobilized enzyme had better application value in the synthesis of OPO structured lipids.

Ultrasonic-assisted stripping of single-crystal SiC after laser modification

Laser stripping technology is an advanced processing method with high efficiency and low material loss, which can greatly reduce material loss in the production process of single-crystal SiC wafer, but the single-crystal SiC ingot still have a certain bonding force after laser modification. Ultrasonic vibration can reduce the bonding force and thus strip single-crystal SiC wafer. In order to investigate the effect of ultrasonic vibration on the reduction of the bonding force of single-crystal SiC internal modification layer, through the ultrasonic-assisted stripping of single-crystal SiC orthogonal experiment, the ultrasonic vibration parameters of ultrasonic frequency, vibration time and ultrasonic power of the three indexes of the reduction of the bonding force was analyzed. The results show that the bonding force of the modified layer decreased by 25 %–60 % after ultrasonic vibration. Variance analysis of the experiment results showed that the main factors influencing the bond strength reduction were vibration time and ultrasonic power in turn. When the vibration time is longer and the ultrasonic power is higher, the stripping force decreases more, and the stripping force of single-crystal SiC wafers decreases up to 60 % under the condition of vibration time of 5min and ultrasonic power of 700 W. Through analysis of the single-crystal SiC cross-section, distinct cleavage steps and cleavage channels are evident. The laser-modified region exhibits defect such as nano-pores, micro-cracks, and nano-particles.After the single-crystal SiC laser modification process was upgraded, the distance between the ultrasonic tool head and the single-crystal SiC was 1.5 mm can directly strip off the single-crystal SiC wafer. And eventually stripped 6-inch single-crystal sic wafers. Therefore, ultrasonic vibration can increase the internal defects in the single-crystal SiC modified layer, causing crack expansion to occur and ultimately stripping the single-crystal SiC wafer.

Sustainable bio-sourced nanoemulsions: Pectin-based delivery systems for vitex essential oil and its therapeutic potentials

Herein we report the feasibility of pectin vitex essential oil (VEO) nanoemulsions (NE). NE formulations were prepared both in the absence and presence of a conventional surfactant (Tween 80) by ultrasonication using pectin aqueous solutions as the aqueous phase and VEO as the oil phase. Different surfactant amounts and various ultrasonication times were employed. Droplet size and Zeta potential measurements were performed and their data were statistically evaluated. The minimum droplet size (prediction: 299.342 nm) could be achieved when employing an ultrasonication time of 5.9 min in the absence of the conventional surfactant. SEM characterization delivered supporting results related to the droplet sizes obtained. Stability tests showed that pectin VEO NE formulations were stable after 42 days. The results clearly showed that it was possible to generate VEO containing NEs in one pot and at once using pectin, which also acted as a natural surfactant, without the need for an additional conventional surfactant. Considering also moisturizing property of pectin and the antifungal activity of VEO, their combination in the form of a nanoemulsion could be promising for potential women’s health applications.

Spectrophotometric determination for green hydrophobic deep eutectic solvent-based microextraction of Brilliant Blue FCF (E133) from beverages

In this study, a simple, sensitive, and rapid method called green hydrophobic deep eutectic solvent-based liquid-liquid microextraction was developed to extract Brilliant Blue FCF dye from beverages. This method utilizes hydrophobic DES obtained by forming tetrabutylammonium bromide and 1-octanol in a 1:5 ratio as green extraction solvent. The transition of Brilliant Blue FCF to the DES phase occurred on its own, without the need for any reagents such as added salt or tetrahydrofuran. Several crucial factors were tried to get the best extraction efficiency, including species, DES volume and molar ratio, solution pH, ultrasonication, and centrifugation time. Under optimum conditions, extraction recoveries were achieved in the range of 95.1–101.3 % with the method developed for Brilliant Blue FCF. The detection and determination limits were observed to be 4.1 μg l-1 and 12.1 μg l-1, respectively. In addition, the relative standard deviation values for the method's accuracy were found to be 2.23 % and 3.48 % within and between days, respectively. It has been established that the developed method is highly environmentally friendly thanks to the application of the Analytical GREENness (AGREE) and Green Analytical Procedure Index (GAPI) tools. This study shows that DES applications can be carried out without the use of emulsifiers and dispersants by prioritizing the use of hydrophobic DES compounds as environmentally friendly and green extraction solvents in food samples.

Using gardenia pigment for ultrasonic natural dyeing of hemp fiber: A step towards sustainable dyeing

In recent years, with the country advocating the establishment of a resource-saving and environmentally friendly society, people have been pursuing a green and healthy quality of life. The non-toxic, harmless, and biodegradable characteristics of grass and wood dyeing have brought this method back to people's lives. Despite the presence of antibacterial substances such as tetrahydrocannabinol in cannabis fibers, they are still susceptible to microbial attacks. In recent years, scholars have conducted more research on the separation and purification of gardenia flower pigments, but there has been less analysis on the dyeing fibers and performance testing of gardenia flowers. The renewable characteristics, fewer side effects, and low cost increase the use of natural drugs as antibacterial agents in plant extracts or their active ingredients. This experiment used gardenia flowers as the raw material for dyeing experiments, and the dyeing percentage was used as the inspection index. Ultrasonic dyeing was carried out on hemp fibers after degumming treatment. It also aims to endow these dyed fabrics with natural antibacterial properties. During the sorting process, a liquid bath ratio of 1:20 was selected and experiments were conducted under different parameter variations. During the dyeing process, potassium aluminum sulfate (alum) is used as a mordant, and ultrasound is used as an auxiliary dyeing method. After dyeing, evaluate the fibers based on the percentage of exhaustion of obtained fiber and antibacterial activity against Staphylococcus aureus and Escherichia coli. At the same time, the FT-IR analysis, strength, and color fastness of the sorted samples were also checked. Single factor experiments were conducted by controlling the ultrasonic frequency, dyeing temperature, time, and mordant concentration to analyze the effect of gardenia pigment on the dyeing percentage. Response surface design experiments were used to optimize the dyeing process parameters. The research results indicate that the optimal process conditions for dyeing gardenia flowers are ultrasonic power of 85 %, dyeing temperature of 77 ℃, dyeing time of 60 min, and mordant concentration of 15 g/L. The main and secondary order of factors affecting the dyeing effect of hemp fibers is: mordant concentration>ultrasonic power>dyeing temperature. After optimal dyeing process, the hemp fiber shows a bright yellow color with a dyeing percentage of 57.32 %. The single fiber strength is not affected, and the color fastness to water washing and sun exposure meets the requirements for consumption. The infrared spectrum shows good dyeing effect. It has a certain antibacterial effect on Staphylococcus aureus, but the antibacterial effect on Escherichia coli is not significant. Due to these processes, it has been determined that hemp fiber can obtain antibacterial activity through the use of gardenia flowers and can be effectively colored.

Experimental study of high-pressure ultrasound-assisted oxidative desulfurization (UAOD) and sulfone adsorption/desorption using zeolite-13X

The sulfurous compounds in natural gas liquids should be reduced to the extent of satisfying the standard recipes due to corrosion, poisoning of catalysts in downstream processes, reduction in the quality of hydrocarbon products and environmental issues. Ultrasound-assisted oxidative desulfurization is an emerging method for sulfur removal from natural gas liquids. Since natural gas liquids exist in the liquid form of hydrocarbons at high pressures and ambient temperature (25 °C), this work aims to investigate the optimal conditions governing ultrasound-assisted oxidative desulfurization for various sulfurous compounds including mercaptan, sulfide and thiophene at high pressure and finally to appraise the adsorption of oxidized sulfurs and the regeneration of the adsorbent using elution with hot water. So, the effects of sulfur content and ultrasonication time were evaluated at 30 bar. Results showed that as the initial sulfur concentration in normal heptane was increased from 0.00 to 3000 ppmS, the sulfur removal efficiency was enhanced by less than 2 % of 95.9 % and of course, the increased ultrasonication time improved the sulfur removal efficiency. Next, results of the sulfone adsorption using zeolite-13X at 30 bar in continuous mode confirmed that the breakthrough time was reduced from 63 to 12 min as the weight hourly space velocity was increased from 5 to 20 h−1 and pursuantly, the mass transfer zone diminished. Besides, the breakthrough time decreased by 45 - 10 min for increasing the initial sulfur content from 200 to 1000 ppmS. Changing the pressure of the adsorption process from 1 to 30 bar caused the improvement of sulfone adsorption capacity by approximately 3.75 times. In continued, the regeneration of zeolite-13X contaminated with sulfone by flowing hot water was evaluated and the zeolite-13X bed was completely regenerated.