加拿大一枝黄花总酚超声提取工艺

利用超声提取的方法,通过单因素和正交实验分析了溶液浓度、超声时间、料液比、提取次数4个主要因素对总酚提取率的影响。确立了加拿大一枝黄花总酚的最佳提取工艺条件为:60%甲醇、超声50min、料液比1∶20、提取3次。在此条件下,总酚的提取率为44.61mg/g。     

Ultrasound-assisted extraction of capsaicinoids from Capsicum frutescens on a lab- and pilot-plant scale

The influence of operating parameters (solvent type, powder to solvent ratio and temperature) on the ultrasonically assisted extraction of capsaicinoids from dried Capsicum frutescens (fruit) was studied. From the economic perspective, the suitable condition for capsaicinoid extraction by indirect sonication in an ultrasonic bath with a working frequency of 35 kHz was at a ratio of 1g of solid material: 5 ml of 95% (v/v) ethanol, 45 degrees C, where 85% of the capsaicinoids were removed from the raw material in 3h. In an experimental pilot study in 20-l extraction tank at the fixed ultrasonic frequency of 26 kHz and 70 kHz, the recovery of capsaicinoids was 76% and 70%, respectively. It was shown that the ultrasonic extraction produced a significant reduction in extraction time at a lower operational temperature than under a conventional industrial hot maceration process.     

Effects of various factors of ultrasonic treatment on the extraction yield of all-trans-lycopene from red grapefruit (Citrus paradise Macf.)

The effects of various factors, including the extraction time, temperature, solvent/material ratio, the ultrasonic intensity and duty cycle of ultrasonic irradiation on the extraction yield of all-trans-lycopene from red grapefruit by ultrasound-assisted extraction (UAE) were investigated. In comparison with conventional solvent extraction (CSE), UAE showed a pronounced greater extraction yield and reduced extraction time effectively with a peak value at 30 min. The extraction yield was significantly influenced by temperature and the optimum condition was 30 °C. The extraction yield increased with increasing of solvent/material ratio until equilibrium was arrived at the optimal ratio of 3:1 (mL/g). The extraction yield increased first and then decreased with an increase in ultrasonic intensity. The extraction yield of UAE increased with the increase of duty cycle, whereas pulsed ultrasound with proper intervals was more efficient than continuous ultrasonication. The degradation via isomerisation of all-trans-lycopene under ultrasonic treatment was also observed with the formation of 9,13′-di-cis-, 9,13-di-cis-, 15-cis-, 13-cis- and 9-cis-lycopene isomers which were tentatively identified by HPLC-PAD.     

Optimization of ultrasonic extraction of 23 elements from cotton

Optimization of ultrasonic extraction of 23 elements from cotton was performed with different solvent volume ratios. For this purpose nitric acid, hydrochloric acid and water were mixed and applied in a mixture for the extraction of elements adsorbed on cotton material. The elements chosen for the extraction procedure (Al, As, Be, Bi, Ca, Cd, Co, Cr, Cu, Fe, Hg, K, Mg, Mn, Mo, Na, Ni, Pb, Sb, Si, Sn, Tl and Zn) were those that are important in textile processing. Some of them cause problems during fiber processing, dyeing or bleaching. The removal of elements from the processed fabric can be successfully done with ultrasonic extraction in the ultrasonic bath. Extraction procedure was optimized by software package Design Expert 6 (DX6) and the optimum of ultrasonic extraction was achieved with the mixture of 1M HCl-1M HNO(3)-H(2)O=3.32/2.83/93.85 (v/v). Ultrasonic extraction was a fast and efficient extraction procedure easily applied on cotton textile material.     

性能可调的纵向振动圆锥形超声变幅杆*

提出了一种基于压电效应的性能可调纵向振动圆锥形超声变幅杆,并对其振动性能进行了研究。该变幅杆由传统的圆锥形超声变幅杆和压电陶瓷材料组合而成。论文研究了圆锥变幅杆中压电陶瓷材料的厚度、位置以及电阻抗的改变对变幅杆性能参数的影响,并进行了数值模拟仿真及实验验证。结果表明,通过改变压电陶瓷材料的厚度、位置和电阻抗值,可以实现变幅杆共振频率和位移放大系数的改变。理论计算结果与数值模拟值和实验测试值符合得很好。     

The enhancement and scale up of the extraction of anti-oxidants from Rosmarinus officinalis using ultrasound

The aim of this study was to examine the effect of ultrasound on the solvent extraction of anti-oxidants from the rosemary herb and to scale up the ultrasonic extraction process. The anti-oxidants of interest were identified using HPLC. Results indicated that, compared with conventional solvent extraction, the use of ultrasound gives a more effective extraction at lower temperatures with less dependence on the extraction solvent employed and that scale up of the process is possible.     

Ultrasound-assisted desolventizing of fragrant oil from red pepper seed by subcritical propane extraction

In the present study, ultrasound was used to remove the residual solvent from the fragrant oil of red pepper seed obtained by subcritical propane extraction. The physical and chemical characteristics, particularly the volatile flavor compounds present of the oil before and after ultrasound-assisted desolventizing were comprehensively analyzed to determine the effect of the desolventizing process on product quality. The results showed that the maximum loss of residual solvent was achieved at a temperature of 90 °C maintained for 70 min with ultrasound applied during the entire process. After this treatment only a small amount of solvent (2.3% based on the total residual solvent originally present) remained in the oil. Although it was hypothesized that ultrasound treatment could result in the loss of volatile components, the analytical results showed no obvious reduction in the components associated with the typical aroma of the oil. After ultrasonic treatment, the oil also had good oxidation stability and quality. Additionally, after ultrasonic desolventizing, the oil samples were more suitable for cooking because they could more effectively minimize oxidation. Thus, these results demonstrate that this new ultrasonic technique is an effective and efficient method for removing the solvent remaining in fragrant oil after subcritical propane extraction.     

Ultrasound-assisted extraction of hesperidin from Penggan (Citrus reticulata) peel

Hesperidin, an abundant and inexpensive bioflavonoid in Penggan (Citrus reticulata) peel, has been reported to possess a wide range of pharmacological properties. Ultrasonic extraction is an effective technique for the isolation of bioactive compounds from vegetable materials. In this study, the application of ultrasonic method was shown to be more efficient in extracting hesperidin from Penggan (C. reticulata) peel than the classical method. The effects of main ultrasonic-assisted extraction conditions on extraction yields of hesperidin from Penggan (C. reticulata) peel were evaluated, including extraction solvents, solvent volume, temperature, extraction time, ultrasonic power, ultrasonic frequency. Results showed that solvent, frequency and processing temperature were the most important factors for improving the extracting yields of hesperidin. When performed at the same temperature under the same time using three frequencies, methanol as the solvent improved the extraction yield evidently compared with ethanol or isopropanol; by comparison of the frequency influence, the yield of hesperidin was higher at 60 kHz than at 20 kHz and 100 kHz. The optimum ultrasonic conditions were determined as: methanol, frequency of 60 kHz, extraction time of 60 min, and temperature of 40 degrees C. In addition, the ultrasonic power had a weak effect on the yields of hesperidin within the experimental range. Extending ultrasonic treatment times did not result in degradation of hesperidin; the rotary beaker for materials can increase the yields of hesperidin.     

Methods of analysis for backscattering from tissues.

Two techniques for tissue characterization by ultrasonic analysis are described. In the first, using narrow-band pulses, the angular variation I (theta) of the ultrasonic intensity back-scattered by vegetal or animal targets is analysed. We examine how it is possible to estimate the surface roughness and the average spatial periodicity d characteristic of the tissues, by calculating the Fourier transform or the autocorrelation function of I (theta). In the second technique the sample is insonified with a broadband pulse at a fixed angle. A value of the mean periodicity can be obtained directly from the frequency spectrum of the echo for tissues of fairly regular structure.     

Ultrasound-homogenization-assisted extraction of polyphenols from coconut mesocarp: Optimization study

Coconut pericarp (shell fiber (mesocarp) and shell (endocarp)), the main by-product of coconut production, is often discarded and causing serious environmental pollution. To make better use of coconut pericarp, the extraction process of polyphenols from coconut mesocarp (CM) carefully studied by screening seven solvent systems, optimizing the assisted ultrasonic process by response surface methodology, and comparing the four processes of Ultrasound-Assisted Extraction (UAE), Homogenization-Assisted Extraction (HAE), Homogenization-Ultrasound-Assisted Extraction (HUAE), and Ultrasound-Homogenization-Assisted Extraction (UHAE). The UAE and HAE are considered to be the main methods for efficient extraction of natural active ingredients. The former effectively destroys the cell wall structure and promotes the intermolecular diffusion based on the cavitation, thermal and mechanical effect of ultrasonic, while the latter breaks the material based on strong shear force between the rotor and stator. Their combinations (HUAE and UHAE) enhance the damage to the cell wall of raw materials and improve the extraction efficiency by the synergistic effect. The results showed that using 60% acetone (V : V) as extraction solvent, solid-liquid ratio of 1:5 g mL⁻¹, ultrasonic temperature of 80 ℃, ultrasonic time of 80 min, ultrasonic power of 225 W, and then homogenizing at 10,000 rpm for 10 min, the total flavonoid content of CM reached the maximum value of 551.99 ± 12.69 mg Rutin g⁻¹ dry weight (dw), while the total phenolic content reached the maximum value of 289.48 ± 4.41 mg GAE g⁻¹ dw at 10,000 rpm for 5 min, which may be related to the oxidative degradation of polyphenols caused by the increase of polyphenol oxidase with the extension of homogenization time. This study provides a technical guarantee for the further utilization of phenolic substances in CM.     

超声辅助法提取白筋茎皮总黄酮的工艺研究

采用超声辅助法提取白霸茎皮中总黄酮化合物,通过单因素试验和正交试验,研究了超声提取条件（超声功率,乙醇浓度,料液比,时间）对其中总黄酮提取的影响。白筋茎皮总黄酮最佳提取工艺为：料液比1：30．乙醇浓度70％,超声功率120W,提取时间25min。在此工艺条件下提取,总黄酮含量为53．0843mg／g。     

超声振动对光学玻璃加工的锯切力特征研究

超声振动辅助方法已在各种硬脆性材料的加工工艺中得以应用,其优异的加工能力和效果已得到广泛证明。本研究中通过采集有无超声振动条件下锯切光学玻璃的平均锯切力以及单颗金刚石磨粒划擦实验下的力信号,对不同工艺条件下的平均锯切力、单颗磨粒受力特征进行分析。同时通过扫描电镜观察对应力信号下工件与工具加工后表面形貌,进一步通过超声振动下材料去除机理解释超声振动对锯切力影响。结果表明：与传统锯切工艺相比,超声振动辅助使得单颗磨粒划擦过程中的受力降低引起平均锯切力的降低;超声振动改变普通锯切下材料的去除方式;同时可使工具保持良好的锯切状态,降低光学玻璃材料的锯切力比,改善其可加工性。     

Kinetics of ultrasonic extraction of extractive substances from garden (Salvia officinalis L.) and glutinous (Salvia glutinosa L.) sage

The kinetics of ultrasonic extraction of extractive substances (ES) from dry herbs of garden (Salvia officinalis L.) and glutinous (Salvia glutinosa L.) sage using petroleum ether, 70% ethanol or water at 40 degrees C, as well as the composition of dry extracts, were studied. The mechanism of ultrasonic extraction is confirmed to occur in two steps: first, dissolution of the ES near the particle surface (washing) and, second, diffusion from the solid particles to the bulk of the liquid extract (slow extraction). The process is described mathematically using three concepts of the unsteady diffusion through plant material, the film theory and the empirical equation of Ponomaryov. The yield of ES increases with increasing solvent polarity, and nearly the maximum concentration of ES in liquid extracts is achieved for about 20 min. The composition of extracts depends on both the extraction conditions applied and the plant material.     

流体动力式超声与槽式超声提取黄芩的比较

目的:比较两种超声发生器对化学反应的促进作用。方法:首先用碘释放测量法进行实验,分别用气哨式流体动力式超声发生器和槽式超声清洗仪处理碘化钾溶液,采用分光光度法测定碘化钾溶液的吸光度。随后分别用流体动力式超声与槽式超声提取黄芩,采用高效液相色谱法测定黄芩苷含量。结果:经流体动力式超声发生器和槽式超声清洗仪处理的碘化钾溶液的吸光度分别为0.990和0.498。以水为溶剂用流体动力式超声提取黄芩,黄芩苷含量显著高于槽式超声。结论:流体动力式发生器(每升能耗0.0156kwh)的空化效应高于槽式超声清洗仪(每升能耗0.0148kwh)。     

Intensification of alkaline delignification of sugarcane bagasse using ultrasound assisted approach

Ultrasound-assisted approach has been investigated for delignification so as to develop green and sustainable technology. Combination of NaOH with ultrasound has been applied with detailed study into effect of various parameters such as time (operating range of 15–90 min), alkali concentration (0.25 M−2.5 M), solvent loading (1:15–1:30 w/v), temperature (50–90 ˚C), power (40–140 W) and duty cycle (40–70 %) at fixed frequency of 20 kHz. The optimized operating conditions established for the ultrasonic horn were 1 M as the NaOH concentration, 1 h as treatment time, 70˚C as the operating temperature, 1:20 as the biomass loading ratio, 100 W as the ultrasonic power and 70% duty cycle yielding 67.30% as the delignification extent. Comparative study performed using conventional and ultrasonic bath assisted alkaline treatment revealed lower delignification as 48.09% and 61.55% respectively. The biomass samples were characterized by SEM, XRD, FTIR and BET techniques to establish the role of ultrasound during the treatment. The morphological changes based on the ultrasound treatment demonstrated by SEM were favorable for enhanced delignification and also the crystallinity index was more in the case of ultrasound treated material than that obtained by conventional method. Specific surface area and pore size determinations based on BET analysis also confirmed beneficial role of ultrasound. The overall results clearly demonstrated the intensification obtained due to the use of ultrasonic reactors.     

超声波强化响应面法优化提取桔皮黄酮

从提取溶剂及提取条件等方面对柑桔皮总黄酮超声波辅助提取工艺进行优化研究.以黄酮得率为考察指标,用单因子试验对提取溶剂进行筛选,用析因试验对提取条件进行分析,通过最陡爬坡试验和中心组合设计试验,优化超声波辅助提取工艺.结果表明,乙醇和水组成的复合体系是理想的提取溶剂;液料比、提取时间、乙醇浓度、pH值都对柑桔皮总黄酮提取产生一定的影响,其中液料比和提取时间的影响最为显著.超声波辅助提取工艺优化条件为:液料比37mL/g,提取时间83min;在此条件下总黄酮的最大提取量为3.321%.经验证试验表明,该方法是一种实用的提取方法.     

超声滚压中的空化现象*

在超声滚压加工中引入切削液后可能会产生空化现象,由此产生的微射流和冲击波对超声表面强化将有积极作用。为研究超声滚压加工中空化现象是否存在及空化效应在超声滚压中的作用,本文首先分析了超声滚压中的空化阈值,然后进行了染色法试验和超声滚压后试样氧元素能谱分析,最后通过超声滚压加工对比试验研究了空化效应对加工后材料表面粗糙度和显微硬度的影响。研究发现,超声滚压加工中的声压幅值远大于空化阈值,满足空化存在的必要条件;超声滚压中发生了明显的卡纸染色现象,引入切削液后工件超声滚压加工表面氧元素含量显著提高,表明超声滚压中发生了空化现象。超声滚压加工中的空化效应能进一步降低工件表面粗糙度和提高表面显微硬度,有利于提高工件表面强化质量。本研究为空化效应在超声滚压中的积极利用提供了依据。     

用于铝板缺陷无损检测的激光超声有限元模拟研究

激光超声技术能够在材料表面形成超声波，是实现材料缺陷无损检测的重要环节。借助Abaqus有限元分析工具，基于激光超声热弹机制建立了轴对称铝板的表面缺陷模型，模拟了激光激发产生的表面波在材料中的传播特性及其与铝板缺陷的相互作用过程。数值模拟实验表明，铝板表面缺陷的分布深度值越大，反射波越强，并且当缺陷深度达到一定程度时，反射波的幅值趋于稳定；但缺陷的分布宽度对于反射波的影响则十分有限。所得结论为基于激光超声的材料缺陷的定量检测及识别提供有效的理论依据。     

The effect of ultrasonic waves in conducting polymer solution

The effects of ultrasonic wave on the conducting polymer polyaniline dissolved in DMSO were observed. The UV-visible, infrared and NMR analysis show that the polymer undergo a redox and doping transition when the ultrasound wave interacts with the polymer dissolved into the solvent. The proposed mechanism to explain these effects is based on the solvent's hygroscopicity properties. The interaction with the ultrasonic wave, homolitically dissociates the water molecule producing radical species, and these species interact with the dissolved conducting polymer changing its oxidation and doped state. The resulting effects of that interaction are the modification of oxidation state of the conducting polymer and the decrease of the amount of water molecule in the solvent. From those results, we have proposed one straightforward method to eliminate water contamination in the solvent DMSO using ultrasonic waves.     

土壤中无机砷测定的三种前处理方法比较

对土壤无机砷分析的样品前处理技术-微波辅助提取、超声波提取、水浴提取进行了对比研究.结合氢化物发生-原子荧光光谱(HG-AFS)测定技术比较了3种方法对国家土壤标准物质中无机砷的提取效果,并对溶剂类型、提取时间和提取剂用量等影响因素进行了考察.与超声波提取法和水浴提取法相比,微波辅助提取法具有快速、高效的优势.