Ultrasonics

超声波
  • 文章类型: Journal Article
    在这里,枸杞用碳酸钠(Na2CO3)预处理,然后通过超声辅助空气干燥或微波干燥进行干燥。在干燥条件下研究了枸杞的水分迁移和酚类化学。三维椭球体输水模型,考虑孔隙度和温度波动,是为了探索干燥机理的复杂性而建立的。一般来说,与超声干燥相比,微波干燥促进了内部水的运输。在所有的干燥方法中,240W(MW-240W)的微波干燥表现出最高的De(从7.34×10-9到9.61×10-9m2/s)和kc(6.78×10-4m/s)值。在所有干燥处理的前2s内,枸杞的表面和中心之间的含水量梯度相当高。微波干燥比空气干燥和超声辅助空气干燥处理更早地降低了水含量梯度。此外,在酚类物质之间观察到的大多数相关性,氧化酶活性,细胞壁果胶与既定的理论不一致,强调了枸杞干燥过程中酚类化学的高度非线性性质。本研究为研究枸杞的传质机理提供了三维模型,并分析了干燥过程中多酚的演变规律。
    Herein, goji berries were pretreated with sodium carbonate (Na2CO3) and then dried via ultrasound-assisted air drying or microwave drying. Water migration and phenolic chemistry of goji berries were studied under drying. A three-dimensional ellipsoid water transport model, accounting for porosity and temperature fluctuations, was established to explore the intricacies of the drying mechanism. Generally, microwave drying promoted interior water transport compared to ultrasound drying. Among all the drying methods, microwave drying at 240 W (MW-240 W) exhibited the highest De (from 7.34 × 10-9 to 9.61 × 10-9 m2/s) and kc (6.78 × 10-4 m/s) values. The goji berries received a considerably high water content gradient between its surface and center within the first 2 s of all the drying treatments. Microwave drying diminished the water content gradient earlier than air drying and ultrasound-assisted air drying treatments. Furthermore, most correlations observed among phenolics, oxidase activity, and cell wall pectin did not align with the established theories, highlighting the highly nonlinear nature of phenolic chemistry during goji berry drying. This study provides a three-dimensional model to study the mass transfer mechanism of goji berries and analyzes the evolution of polyphenols during the drying process.
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  • 文章类型: Journal Article
    超声波加湿器通常用于家庭以保持室内湿度并产生大量的液滴或喷雾气溶胶。然而,有各种与加湿器使用相关的健康问题,主要是由于操作过程中产生的气溶胶。这里,我们调查了大小分布,化学成分,和从商业超声波加湿器发出的气溶胶颗粒的带电部分。发现用于加湿器的水中的重金属在超声加湿器气溶胶(UHA)中高度富集,富集系数在102到107之间。这种浓缩可能会给建筑居住者带来健康问题,观察到UHA浓度高达106个颗粒/cm3或3mg/m3。此外,观察到大约90%的UHA带电,根据我们的知识,这是第一次。基于这一发现,我们提出并测试了一种通过使用简单的电场来去除UHA的新方法。在这项工作中设计的电场可以有效地去除81.4%的UHA。因此,应用该电场可能是UHA显着降低健康风险的有效方法。
    Ultrasonic humidifiers are commonly used in households to maintain indoor humidity and generate a large number of droplets or spray aerosols. However, there have been various health concerns associated with humidifier use, largely due to aerosols generated during operation. Here, we investigated the size distribution, chemical composition, and charged fraction of aerosol particles emitted from commercial ultrasonic humidifiers. Heavy metals in water used for humidifiers were found to be highly enriched in the ultrasonic humidifier aerosols (UHA), with the enrichment factors ranging from 102 to 107. This enrichment may pose health concerns for the building occupants, as UHA concentrations of up to 106 particles/cm3 or 3 mg/m3 were observed. Furthermore, approximately 90% of UHA were observed to be electrically charged, for the first time according to our knowledge. Based on this discovery, we proposed and tested a new method to remove UHA by using a simple electrical field. The designed electrical field in this work can efficiently remove 81.4% of UHA. Therefore, applying this electrical field could be an effective method to significantly reduce the health risks by UHA.
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  • 文章类型: Journal Article
    使用天然深共晶溶剂(UAE-NADES)的超声波辅助提取是提取葡萄籽多酚(GSPs)的有效方法。在这项研究中,采用响应面法优化UAE-NADES提取GSPs,GSPs的理论提取率为139.014mgGAE/g,实际提取率为135.78±1.3mgGAE/g。建立了拟二级动力学萃取拟合来模拟萃取过程和机理(R2>0.99)。抗氧化能力分析,傅里叶红外光谱和扫描电子显微镜显示,UAE-NADES协同作用以保持提取的GSP的稳定性。高效液相色谱结果表明,儿茶素(41.14mg/g)是提取物中GSPs的主要成分。UAE-NADES提取的GSPs在0.25mgGAE/g时可以抑制链格孢菌的生长,而其他方法提取的GSPs在0.35mgGAE/g时可有效抑制链格孢菌的生长。因此,这项研究表明,UAE-NADES是提取GSP的高效手段,在更广泛的意义上,是一种很有前途的废弃资源绿色利用提取技术。
    Ultrasonic-assisted extraction using a natural deep eutectic solvent (UAE-NADES) is an efficient method for extracting grape seed polyphenols (GSPs). In this study, response surface methodology was used to optimize the extraction of GSPs with UAE-NADES, and the theoretical extraction rate of GSPs was 139.014 mg GAE/g, the actual extraction rate was 135.78 ± 1.3 mg GAE/g. A pseudo-second-order kinetic extraction fitting was established to simulate the extraction process and mechanism (R2 > 0.99). Analysis of antioxidant capacity, Fourier-infrared spectroscopy and scanning electron microscopy revealed that UAE-NADES works synergetically to maintain the stability of extracted GSPs. The results of high-performance liquid chromatography showed that catechin (41.14 mg/g) is the main component of GSPs in the extract. The UAE-NADES extraction of GSPs can inhibit the growth of Alternaria alternata at 0.25 mg GAE/g, while the GSPs extracted by other methods can effectively inhibit the growth of Alternaria alternata at 0.35 mg GAE/g. Thus, this study demonstrates that UAE-NADES is a high-efficiency means of extracting GSPs and, in a wider sense, is a promising extraction technology for the green utilization of waste resources.
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  • DOI:
    文章类型: Journal Article
    目的:探讨超声冲洗联合洗必泰在牙髓炎根管治疗中的临床效果。
    方法:将120例根管治疗牙髓炎患者随机分为研究组(60、72颗患牙)和对照组(60、70颗患牙)。在根管预备期间,研究组采用氯己定联合超声冲洗,对照组采用氯己定常规灌洗。比较两组根管预备前后根管内细菌计数和内毒素含量,以及牙髓性相互间疼痛(EIAP),侧支根管充填率,根管治疗后牙齿疼痛程度。随访1年,对治疗成功率进行统计学分析。采用SPSS19.0软件包进行统计学分析。
    结果:根管预备后,与根管预备前相比,实验组和对照组菌落数明显减少(P<0.05),实验组菌落数明显低于对照组(P<0.05)。根管预备后,实验组和对照组的内毒素水平明显低于根管预备前(P<0.05),实验组水平明显低于对照组(P<0.05).研究组和对照组的侧支根管充填率分别为29.17%和11.43%,分别,组间差异有统计学意义(P<0.05)。EIAP的发生率分别为4.17%和14.29%,分别,两组比较差异有统计学意义(P<0.05)。手术后48小时,研究组和对照组的视觉模拟评分(VAS)分别为(2.74±0.61)和(3.29±0.68),分别,显著低于术前(P<0.05)。两组患者术后48hVAS评分比较,差异有统计学意义(P<0.05).手术后一周,研究组和对照组的VAS评分分别为(1.52±0.34)和(1.81±0.42),分别,术前、术后48h显著降低(P<0.05)。两组术后1周VAS评分比较差异有统计学意义(P<0.05).对照组治疗成功率为84.62%,研究组为95.71%,两组比较差异有统计学意义(P<0.05)。
    结论:应用超声冲洗联合洗必泰治疗牙髓炎根管有助于降低根管预备后细菌和内毒素水平。减轻术后牙齿疼痛的程度,提高侧枝根管的充填率,具有优越的疗效。
    OBJECTIVE: To explore the clinical effect of ultrasonic irrigation combined with chlorhexidine in root canal treatment of pulpitis.
    METHODS: A total of 120 patients with pulpitis treated with root canal therapy were randomly divided into a study group (n=60, 72 affected teeth) and a control group (n=60, 70 affected teeth). During root canal preparation, the study group was treated with chlorhexidine combined with ultrasonic irrigation, while the control group was treated with chlorhexidine conventional irrigation. The bacterial count and endotoxin content in the root canal before and after root canal preparation were compared between the two groups, as well as the endodontic inter-appointment pain (EIAP), lateral branch root canal filling rate, and degree of tooth pain after root canal treatment. The success rate of treatment was statistically analyzed after one-year follow-up. Statistical analysis was performed with SPSS 19.0 software package.
    RESULTS: After root canal preparation, the number of colonies in experimental group and control group was significantly decreased compared with that before root canal preparation(P<0.05), and the number of colonies in experimental group was significantly lower than that in control group(P<0.05). After root canal preparation, endotoxin levels in experimental group and control group were significantly lower than those before root canal preparation(P<0.05), and the level in experimental group was significantly lower than that in control group(P<0.05). The lateral branch root canal filling rate in the study group and the control group was 29.17% and 11.43%, respectively, with significant difference between the groups(P<0.05). The incidence of EIAP was 4.17% and 14.29%, respectively, with significant difference between the two groups(P<0.05). At 48 hours after surgery, the visual analogue score (VAS) of the study group and the control group was (2.74±0.61) and (3.29±0.68), respectively, which were significantly lower than at before surgery(P<0.05). There was a significant difference in VAS score between the two groups 48 hours after surgery(P<0.05). One week after surgery, the VAS score in the study group and the control group was (1.52±0.34) and (1.81±0.42), respectively, significantly lower than that before and 48 hours after surgery(P<0.05). There was a significant difference in VAS score between the two groups at one week after surgery (P<0.05). The successful rate of treatment in the control group was 84.62%, and 95.71% in the study group, with a significant difference between the two groups(P<0.05).
    CONCLUSIONS: The application of ultrasonic irrigation combined with chlorhexidine in the treatment of pulpitis root canals can help reduce the level of bacteria and endotoxin after root canal preparation, alleviate the degree of postoperative tooth pain, and improve the filling rate of lateral branch root canals, with superior curative effects.
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  • 文章类型: Journal Article
    食物过敏是世界上主要的公共卫生疾病。超声波是一种环境友好的技术,通常会导致蛋白质展开和蛋白质结构丢失,这意味着它有可能与其他技术相结合,以实现食品中致敏性的大大降低。本文从三个组合总结了超声与其他技术联合对食品致敏性的影响:超声先于其他技术,其他技术下的超声,和其他技术之后的超声波。每种组合都会通过不同的机制影响食物的致敏性:(1)至于其他技术之前的超声,超声预处理可以展开和失去蛋白质结构,以提高其他技术对表位的可及性;(2)对于其他技术下的超声,超声可以持续影响其他技术对表位的可及性;(3)至于其他技术之后的超声,超声进一步诱导结构变化来掩盖和破坏表位。致敏性的降低与超声/其他技术条件和食物类型/品种有关,等。超声前的比较,under,在其他降低食品致敏性的技术之后,未来应进一步研究。超声波与其他技术的结合有望生产低过敏性食品。
    Food allergies are a main public health disease in the world. Ultrasound is an environmentally friendly technology that typically leads to protein unfolding and loss of protein structure, which means it has the potential to be combined with other technologies to achieve a great reduction of allergenicity in foods. This review concludes the effects of the combined ultrasound with other technologies on food allergenicity from three combinations: ultrasound before other technologies, ultrasound under other technologies, and ultrasound after other technologies. Each combination affects food allergenicity through different mechanisms: (1) as for ultrasound before other technologies, ultrasound pretreatment can unfold and lose the protein structure to improve the accessibility of other technologies to epitopes; (2) as for ultrasound under other technologies, ultrasound can continuously affect the accessibility of other technologies to epitopes; (3) as for ultrasound after other technologies, ultrasound further induces structural changes to mask and disrupt the epitopes. The reduction of allergenicity is related to the ultrasound/other technologies conditions and food types/cultivars, etc. The comparison of ultrasound before, under, and after other technologies to decrease food allergenicity should be further investigated in the future. The combination of ultrasound with other technologies is promising to produce hypoallergenic foods.
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  • 文章类型: Journal Article
    锗(Ge)是主要从二次含Ge资源中回收的分散金属。传统的处理方法因杂质去除不彻底而受阻,导致低品位的单宁锗残留物(TGR)和Ge精矿,生产成本高,和重大危险废物。这项研究提出了一种涉及超声预纯化TGR的新技术,以提高通过焙烧制备的Ge精矿的质量。在最佳条件下(超声功率225W,液固比7:1,H2SO4浓度20g/L,反应时间30分钟,和反应温度40°C),杂质Zn的去除效率,Mg,Fe,As,来自纯化单宁锗残留物(PTGR)的S增加了4.2%,4.2%,17.4%,8.7%,和分别为2.9%。此外,PTGR中的Ge含量从2.9%增加到4.1%。超声作用机理表明,超声能量使反应物的粒径从67.698μm降至31.768μm,从而加速杂质去除。在650°C下用40L/h的空气流量将超声波纯化的单宁锗残留物(U-PTGR)焙烧120分钟,产生的Ge精矿的Ge品位为33.26%,比常规方法高6.11%。使用XRD和HRTEM进行分析,结合微晶尺寸计算,表明U-PTGR制备的Ge精矿具有较低的烧结度,良好的晶体性能,和高结晶度。实施这项技术每年可为企业节省约57,412美元的生产成本。此外,它对减少危险废物排放和促进Ge产业的高质量发展具有重要的现实意义。
    Germanium (Ge) is a dispersed metal primarily recovered from secondary Ge-containing resources. The traditional treatment method is hindered by incomplete impurity removal, resulting in a low grade of tannin germanium residue (TGR) and Ge concentrate, high production costs, and significant hazardous waste. This study proposes a new technology involving ultrasonic pre-purification of TGR to enhance the quality of Ge concentrate prepared by roasting. Under optimal conditions (ultrasonic power 225 W, liquid-solid ratio 7:1, H2SO4 concentration 20 g/L, reaction time 30 min, and reaction temperature 40 °C), the removal efficiencies of impurities Zn, Mg, Fe, As, and S from purified tannin germanium residue (PTGR) increased by 4.2%, 4.2%, 17.4%, 8.7%, and 2.9% respectively. Moreover, the Ge content in PTGR increased from 2.9% to 4.1%. The mechanism of ultrasonic action indicated the ultrasonic energy reduced the particle size of the reactants from 67.698 μm to 31.768 μm, thereby accelerating impurity removal. Roasting ultrasonic-purified tannin germanium residue (U-PTGR) at 650 °C with 40 L/h air flow for 120 min produced Ge concentrate with a Ge grade of 33.26%, which is 6.11% higher than the regular method. Analysis using XRD and HRTEM, combined with crystallite size calculation, revealed that the Ge concentrate prepared by U-PTGR exhibited low sintering degree, good crystal properties, and high crystallinity. Implementing this technology could save enterprises approximately $57,412 annually in production costs. Additionally, it holds significant practical importance in reducing hazardous waste emissions and promoting the high-quality development of the Ge industry.
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  • 文章类型: Journal Article
    本研究通过使用双频超声(DFUS)研究了食品中黄曲霉毒素B1(AFB1)的降解以及声化学氧化对功效的影响。研究发现,浴超声(BU)降解AFB1,探头超声(PU),和DFUS均符合一级动力学。DFUS的使用使AFB1降解率显着提高到91.3%,与BU和PU相比,治疗30分钟后增加了约177.0%和61.5%。DFUS可以产生协同作用,加速自由基的产生,促进声化学氧化降解AFB1。可以推测,羟自由基(·OH)可能在DFUS降解AFB1中起主要作用,和氢原子(·H)也可能有贡献。这些结果表明DFUS是一种有效的AFB1降解方法。
    This study investigated the degradation of aflatoxin B1 (AFB1) in food by using dual-frequency ultrasound (DFUS) and the effects of sonochemical oxidation on the efficacy. It was found that the degradation of AFB1 by bath ultrasound (BU), probe ultrasound (PU), and DFUS were all consistent with first-order kinetics. The use of DFUS significantly increased the AFB1 degradation to 91.3%, and compared with BU and PU, it increased by about 177.0% and 61.5% after 30 min treatment. DFUS could generate a synergistic effect to accelerate the generation of free radicals, which promoted sonochemical oxidation to degrade AFB1. It could be speculated that hydroxyl radical (·OH) probably acted a dominant part in the AFB1 degradation by DFUS, and the hydrogen atoms (·H) might also are contributed. These results indicated that DFUS was an effective method of AFB1 degradation.
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  • 文章类型: Journal Article
    中药活性成分的提取受到了广泛的关注。在这项研究中,选用16种天然低共熔溶剂(NADES)超声提取紫山药根皂苷,并对其提取机理进行了研究。结果表明,氯化物/丙烯酸(1:2;n/n)对皂苷的提取率最高。最佳提取工艺参数为含水量24%,20mL/g液固比,超声提取85分钟(81℃,600瓦)。紫山药皂苷的提取率(ER)为0.935%,接近96.5mg/g的拟合结果。分子动力学模拟和FT-IR结果表明,NADES可以通过氢键从紫山药中提取皂苷成分。与传统的提取方法和分子印迹聚合物方法相比,NADES具有较高的ER和较低的成本(1.53$/g),为后续工业定量生产提供参考。
    The extraction of active ingredients from traditional Chinese medicine has received considerable attentions. In this study, 16 kinds of natural deep eutectic solvent (NADES) with ultrasonic were selected to extract saponins from purple yam root and the extraction mechanism was investigated. The results showed that chloride/acrylic acid (1:2; n/n) had the highest extraction yield for saponins. The optimal extraction process parameters were 24% water content, 20 mL/g liquid-solid ratio, and ultrasonic extraction for 85 min (81 °C, 600 W). The extraction rate (ER) of purple yam saponins was 0.935%, close to the fitted result of 96.5 mg/g. Molecular dynamics simulations and FT-IR results showed that the NADES may extract the saponin constituents from purple yam through hydrogen bonding. Compared with traditional extraction methods and molecularly imprinted polymer methods, NADES has a higher ER and lower cost (1.53 $/g), which provides a reference for subsequent industrial quantitative production.
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  • 文章类型: Journal Article
    热塑性淀粉,作为石油基塑料的环保替代品,拥有众多优势,包括成本效益,完全可生物降解,和可再生采购。然而,通过剪切变形占主导地位的加工方法,增塑剂分散性和淀粉增塑效率较差。因此,本研究的目的是提出一种将超声处理和拉伸流变相结合的新方法来制备热塑性淀粉并评估其性能。这种创新的方法促进了在不同的转子速度下以甘油作为增塑剂的热塑性淀粉的生产。此外,这项研究是通过使用基于伸长流的自行开发的超声辅助叶片混合器(UVM)进行的。使用FTIR对样品进行分析,WAXD,偏振光学显微镜,动态流变仪,万能试验机和热重分析。FTIR和动态流变分析表明,拉伸流变和超声波刺激淀粉和甘油之间的氢键形成,提高淀粉的热塑性。拉伸测试和热重分析强调,高强度伸长场改善了热塑性淀粉的机械性能和热稳定性。此外,超声波处理的结合产生了进一步的改善,产生显著的拉伸强度(6.09MPa)和断裂伸长率(139.3%)。超声和伸长流变学之间的这种协同相互作用对于推进热塑性淀粉制造具有巨大的潜力。
    Thermoplastic starch, as an eco-friendly alternative to petroleum-based plastics, possesses numerous advantages, including cost-effectiveness, complete biodegradability, and renewable sourcing. Nevertheless, the plasticizer dispersion and starch plasticization efficiency are poor via the processing method dominate by shear deformation. Thus, the aim of this study is proposing a new approach combining ultrasonic treatment and elongational rheology to prepare thermoplastic starch and evaluate its properties. This innovative approach facilitated the production of thermoplastic starch with glycerol as the plasticizer at varying rotor speeds. Furthermore, this study was carried out by using a self-developed ultrasonic-assisted vane mixer (UVM) based on elongational flow. The samples were analyzed using FTIR, WAXD, polarized optical microscope, dynamic rheometer, universal testing machine and thermogravimetric analysis. FTIR and dynamic rheological analysis showed that elongational rheology and ultrasonics stimulate hydrogen bond formation between starch and glycerol, elevating starch thermoplasticity. Tensile tests and thermogravimetric analysis highlighted that high-intensity elongational field improved the mechanical properties and thermal stability of the thermoplastic starch. Additionally, the incorporation of ultrasonic treatment yielded further improvements, yielding remarkable tensile strength (6.09 MPa) and elongation at break (139.3 %). This synergistic interplay between ultrasonics and elongational rheology holds immense potential for advancing thermoplastic starch manufacturing.
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  • 文章类型: Journal Article
    在本文中,通过调节棕榈油/棕榈硬脂/大豆油的比例,由20%水相和80%油相制备了两种固体脂肪含量高和低的乳液体系。采用不同超声功率和时间对不同固体脂肪含量的乳化液进行预处理,并对超声波在W/O乳液中的应用特性进行了探索和评价。直接使用高强度超声制备脂肪乳液会削弱样品的硬度和储能模量G'。尽管超声波减少了乳剂中脂肪晶体的大小,需要考虑水滴和脂肪晶体之间的相互作用。超声波处理后,水滴难以固定在晶体表面上,因此充当活性填料以稳定乳液和脂肪晶体网络。在高固体脂肪乳剂系统中,与超声持续时间的增加(从30s到60s)相比,超声功率的增加(从100W到200W)对脂肪结晶行为的影响更大。晶体和液滴的分布更加均匀。在低固体脂肪乳剂系统中,超声处理后的样品质地较软,表面更细腻,更光滑。然而,较高的超声强度(200W)不利于制剂的铺展。虽然强度过大的超声促进了小晶体的形成,这也会导致小晶体的聚集。这些小晶体不能形成均匀的晶体网络,这增加了乳液的流动性。
    In this paper, two emulsion systems with high and low solid fat contents were prepared from 20 % water phase and 80 % oil phase by adjusting the palm oil/palm stearin/soybean oil ratio. Different ultrasonic power and time were used for the pretreatment of emulsion with different solid fat content, and the application characteristics of ultrasonic in W/O emulsions were explored and evaluated. Directly using high-intensity ultrasound to prepare fatty emulsions would weaken the hardness and storage modulus G\' of the samples. Although ultrasound reduced the size of fat crystals in emulsions, the interaction between water droplets and fat crystals needs to be considered. After ultrasonic treatment, water droplets were difficult to immobilize on the crystal surface and thus acted as an active filler to stabilize the emulsion together with the fat crystal network. In high solid fat emulsion systems, an increase in ultrasound power (from 100 W to 200 W) could more affect the crystallization behavior of fats than an increase in ultrasound duration (from 30 s to 60 s), and the distribution of crystals and droplets was more uniform. In the low solid fat emulsion system, the texture of the sample after ultrasonic treatment was softer, and the surface was more delicate and smoother. However, the higher ultrasonic intensity (200 W) was not conducive to the preparation of the spread. Although the ultrasound with excessive intensity promoted the formation of small crystals, it would also lead to the aggregation of small crystals. These small crystals cannot form a uniform crystal network, which increases the fluidity of emulsions.
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