Distillation

蒸馏
  • 文章类型: Journal Article
    这项工作使用顶空固相微萃取-气相色谱-质谱法(HS-SPME-GC-MS)分析了柑橘×'Daidai'和柑橘×aurantiumL.干芽(CAVA和CADBs)的水溶胶的挥发性成分。结果表明,在水溶胶中总共检测到106种挥发物,主要是酒精,烯烃,和酯类,水溶胶的高含量成分是芳樟醇,α-松油醇,和反式香叶醇.就品种而言,CAVA水溶胶的总组分和独特组分远高于CADB水溶胶;CAVA水溶胶中13种组分的相对含量大于CADB水溶胶,乙酸香叶酯高达15倍;所有的水溶胶都有柑橘,花卉,和木质香气。从预处理,更多的挥发性成分保留在浸泡中;通过超声-微波程序增加芳樟醇和α-松油醇的相对含量;超声-微波程序有利于激发CAVA水溶胶的香气,但它减少了CADB水溶胶的香气。本研究为基于CAVA药食同源特性的深入探索和提高废弃资源利用率提供了理论支持。
    This work used headspace solid-phase microextraction with gas chromatography-mass spectrometry (HS-SPME-GC-MS) to analyze the volatile components of hydrosols of Citrus × aurantium \'Daidai\' and Citrus × aurantium L. dried buds (CAVAs and CADBs) by immersion and ultrasound-microwave synergistic-assisted steam distillation. The results show that a total of 106 volatiles were detected in hydrosols, mainly alcohols, alkenes, and esters, and the high content components of hydrosols were linalool, α-terpineol, and trans-geraniol. In terms of variety, the total and unique components of CAVA hydrosols were much higher than those of CADB hydrosols; the relative contents of 13 components of CAVA hydrosols were greater than those of CADB hydrosols, with geranyl acetate up to 15-fold; all hydrosols had a citrus, floral, and woody aroma. From the pretreatment, more volatile components were retained in the immersion; the relative contents of linalool and α-terpineol were increased by the ultrasound-microwave procedure; and the ultrasound-microwave procedure was favorable for the stimulation of the aroma of CAVA hydrosols, but it diminished the aroma of the CADB hydrosols. This study provides theoretical support for in-depth exploration based on the medicine food homology properties of CAVA and for improving the utilization rate of waste resources.
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  • 文章类型: Journal Article
    二十二碳六烯酸在婴儿脑功能中起着至关重要的作用,高纯度二十二碳六烯酸的市场需求不断增加。天然鱼油中二十二碳六烯酸的可用性有限,促使人们探索微藻类等替代来源。对于藻类油,酶法乙醇分解比化学方法更优选,因为前者更温和,可以避免二十二碳六烯酸氧化。然而,由于脂肪酶对长链多不饱和脂肪酸的底物特异性差,酶法的产率通常较低,影响二十二碳六烯酸的收率和纯度。因此,我们开发了一种从藻类油生产高纯度二十二碳六烯酸乙酯的有效方法,通过筛选脂肪酶,优化酶解和应用分子蒸馏。脂肪酶UM1是由藻类油生产乙酯的最佳脂肪酶,乙酯收率最高(95.41%)。同时,它是长链多不饱和脂肪酸与乙醇反应的催化剂。二十二碳六烯酸的脂肪酸转化率超过90%。分子蒸馏后,得到含有96.52%乙酯的最终产物,其中二十二碳六烯酸含量高达80.11%。我们的发现为生产高纯度二十二碳六烯酸乙酯提供了一种高效的酶法,具有潜在的商业应用。
    Docosahexaenoic acid plays a crucial role in infant brain function, and the market demand of high-purity docosahexaenoic acid is continuously increasing. The availability of docosahexaenoic acid in natural fish oil is limited, prompting the exploration of alternative sources like microalgae. For algal oil, enzymatic ethanolysis is preferred to chemical methods because the former is milder and can avoid docosahexaenoic acid oxidation. However, enzymatic methods have generally low yield due to the poor substrate-specificity of lipase to long-chain polyunsaturated fatty acids, affecting the yield and purity of docosahexaenoic acid. Therefore, we developed an efficient process to produce high-purity docosahexaenoic acid ethyl ester from algal oil, by screening lipases, optimizing enzymatic ethanolysis and applying molecular distillation. Lipase UM1 was the best lipase to produce ethyl ester from algal oil with the highest ethyl ester yield (95.41%). Meanwhile, it was a catalyst for the reaction of long-chain polyunsaturated fatty acids with ethanol. The fatty acid docosahexaenoic acid conversion rates exceeded 90%. After molecular distillation, a final product containing 96.52% ethyl ester was obtained with a docosahexaenoic acid content up to 80.11%. Our findings provide an highly effective enzymatic method for the production of high-purity docosahexaenoic acid ethyl esters, with potential commercial applications.
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  • 文章类型: Journal Article
    已研究了精油(EO)对真菌水果病原体的有效性。本综述文章总结了在果实收获前后阶段抑制链格孢菌和炭疽菌的EO。选择了39篇科学论文,重点研究了EO的提取条件和抗真菌活性。检索到的研究主要来自中国和巴西。加氢蒸馏已被确定为最常用的萃取方法。产量和化学特征在物种之间是可变的。体外研究大于体内研究。EO的应用降低了番茄真菌病的发生率(Lycopersiconesculentum),木瓜(番木瓜)和芒果(芒果)。EO是治疗水果真菌疾病的潜在生态替代品,需要进一步研究。
    Essential oils (EOs) have been investigated for their effectiveness against fungal fruit pathogens. The present review article summarises the EOs that inhibit Alternaria alternata and Colletotrichum gloeosporioides in the pre- and post-harvest stages of fruits. Thirty-nine scientific papers focusing on the extraction conditions and the antifungal activity of EOs were selected. The retrieved studies came mainly from China and Brazil. Hydrodistillation has been identified as the most used extractive method. The yields and chemical profiles were variable among the species. The in vitro studies were larger than the in vivo studies. The application of EOs reduced the incidence of fungal diseases in tomatoes (Lycopersicon esculentum), papaya (Carica papaya) and mango (Mangifera indica). EOs resulted as a potential ecological alternative for treating fungal diseases in fruits requiring further investigation.
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  • 文章类型: Journal Article
    膜蒸馏(MD)为回收页岩气采出水(SGPW)提供了希望,而膜污染仍然是独立MD的主要障碍。在这里,提出了过碳酸钠(SPC)氧化作为MD预处理,以及单个MD的性能,对SGPW处理的SPC-MD混合工艺和Fe(II)/SPC-MD混合工艺进行了系统评价。结果表明,与原始SGPW相比,SPC和Fe(II)/SPC的应用导致荧光有机物分别减少28.54%和54.52%,分别。疏水性分数从原始SGPW中的52.75%下降到SPC和Fe(II)/SPC的37.70%和27.20%,分别,MD归一化通量从处理原始SGPW时的0.19分别增加到0.65和0.81。通过扫描电镜观察进一步证实了SPC氧化在减少沉积的膜污垢和恢复膜性能方面的优越性,衰减全反射傅里叶变换红外,结垢膜的水接触角和表面张力分析。相关分析表明,SGPW中的疏水/亲水物质和荧光有机物在MD污染中起着至关重要的作用。通过Fe(II)/SPC氧化缓解MD污染的机理归因于通过协同氧化降低有机物的浓度和疏水性,混凝和吸附。
    Membrane distillation (MD) offers promise for recycling shale gas produced water (SGPW), while membrane fouling is still a major obstacle in standalone MD. Herein, sodium percarbonate (SPC) oxidation was proposed as MD pretreatment, and the performance of the single MD, SPC-MD hybrid process and Fe(II)/SPC-MD hybrid process for SGPW treatment were systematically evaluated. Results showed that compared to raw SGPW, the application of SPC and Fe(II)/SPC led to the decrease of the fluorescent organics by 28.54 % and 54.52 %, respectively. The hydrophobic fraction decreased from 52.75 % in raw SGPW to 37.70 % and 27.20 % for SPC and Fe(II)/SPC, respectively, and the MD normalized flux increased from 0.19 in treating raw SGPW to 0.65 and 0.81, respectively. The superiority of SPC oxidation in reducing the deposited membrane foulants and restoring membrane properties was further confirmed through scanning electron microscopy observation, attenuated total reflection fourier transform infrared, water contact angle and surface tension analyses of fouled membranes. Correlation analysis revealed that hydrophobic/hydrophilic matters and fluorescent organics in SGPW took a crucial role in MD fouling. The mechanism of MD fouling mitigation by Fe(II)/SPC oxidation was attributed to the decrease in concentrations and hydrophobicity of organic by synergistic oxidation, coagulation and adsorption.
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  • 文章类型: Journal Article
    该文献计量分析对1990年至2023年的膜蒸馏(MD)研究进行了全面调查。涵盖4389种出版物,分析揭示了进化,趋势,以及该领域的未来方向。它深入研究了作者身份模式,出版趋势,著名期刊,以及揭示合作网络的全球贡献,研究热点,以及MD研究中新兴的主题。研究结果表明,广泛的全球参与,诸如海水淡化和膜科学杂志等备受尊敬的期刊是传播前沿研究的关键平台。分析进一步确定了推动MD研究的关键主题和概念,从膜特性到减轻膜污染的策略。共现分析进一步突出了研究主题的相互关联性,展示材料的进步,可持续供暖战略,污染物处理,和资源管理。叠加共现分析为新兴研究趋势提供了时间视角,勾勒出可能塑造MD未来的六个关键主题。这些包括材料和表面工程方面的创新,可持续供暖战略,新兴污染物处理,可持续水资源管理,数据驱动的方法,和可持续性评估。最后,这项研究是研究人员和工程师浏览MD研究动态景观的路线图,提供对当前趋势和未来轨迹的见解,最终旨在推动MD技术提高性能,可持续性和全球相关性。
    This bibliometric analysis offers a comprehensive investigation into membrane distillation (MD) research from 1990 to 2023. Covering 4389 publications, the analysis sheds light on the evolution, trends, and future directions of the field. It delves into authorship patterns, publication trends, prominent journals, and global contributions to reveal collaborative networks, research hotspots, and emerging themes within MD research. The findings demonstrate extensive global participation, with esteemed journals such as Desalination and the Journal of Membrane Science serving as key platforms for disseminating cutting-edge research. The analysis further identifies crucial themes and concepts driving MD research, ranging from membrane properties to strategies for mitigating membrane fouling. Co-occurrence analysis further highlights the interconnectedness of research themes, showcasing advancements in materials, sustainable heating strategies, contaminant treatment, and resource management. Overlay co-occurrence analysis provides temporal perspective on emerging research trends, delineating six key topics that will likely shape the future of MD. These include innovations in materials and surface engineering, sustainable heating strategies, emerging contaminants treatment, sustainable water management, data-driven approaches, and sustainability assessments. Finally, the study serves as a roadmap for researchers and engineers navigating the dynamic landscape of MD research, offering insights into current trends and future trajectories, ultimately aiming to propel MD technology towards enhanced performance, sustainability, and global relevance.
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  • 文章类型: Journal Article
    这项研究的目的是评估预处理和不同工艺条件对黑麦秸秆(RS)ABE发酵过程以及所得馏出物中挥发性化合物组成的影响。通过碱水解,然后进行脱毒和酶水解,从预处理的黑麦秸秆的发酵中获得最高浓度的ABE和丁醇。发酵72小时后,最大丁醇浓度,生产力,RS的产量为16.11g/L,0.224g/L/h,和0.402g/g,分别。测试了三种不同的生产丁醇的方法:两步法(SHF),同步过程(SSF),和同时糖化与ABE发酵(合并SHF/SSF)。SHF/SSF过程观察到ABE浓度(21.28g/L)高于SSF(20.03g/L),而低于SHF(22.21g/L)。分析了脱毒过程和各种ABE发酵技术对发酵和蒸馏过程中形成的挥发性化合物组成的影响。
    The objective of this study was to evaluate the effect of pretreatment and different technological conditions on the course of ABE fermentation of rye straw (RS) and the composition of volatile compounds in the distillates obtained. The highest concentration of ABE and butanol was obtained from the fermentation of pretreated rye straw by alkaline hydrolysis followed by detoxification and enzymatic hydrolysis. After 72 h of fermentation, the maximum butanol concentration, productivity, and yield from RS were 16.11 g/L, 0.224 g/L/h, and 0.402 g/g, respectively. Three different methods to produce butanol were tested: the two-step process (SHF), the simultaneous process (SSF), and simultaneous saccharification with ABE fermentation (consolidation SHF/SSF). The SHF/SSF process observed that ABE concentration (21.28 g/L) was higher than in the SSF (20.03 g/L) and lower compared with the SHF (22.21 g/L). The effect of the detoxification process and various ABE fermentation technologies on the composition of volatile compounds formed during fermentation and distillation were analyzed.
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  • 文章类型: Journal Article
    大规模变压器的兴起导致了有关计算成本和能耗的挑战。在这种情况下,尖峰神经网络(SNN)由于其能量效率和处理速度而提供了潜在的解决方案。然而,代理梯度和特征空间量化的不准确性对直接训练深度SNN变压器提出了挑战。为了应对这些挑战,我们提出了一种方法(称为LDD),以在Transformer网络中的不同抽象级别上对齐ANN和SNN功能。LDD结合了来自ANN的结构化特征知识,以指导SNN训练,通过设计逐层蒸馏损失,确保关键信息的保存和解决替代梯度的不准确性。所提出的方法优于CIFAR10上的现有方法(96.1%),CIFAR100(82.3%),和ImageNet(80.9%)数据集,并使用ImageNet训练最深的SNN变压器网络。
    The rise of large-scale Transformers has led to challenges regarding computational costs and energy consumption. In this context, spiking neural networks (SNNs) offer potential solutions due to their energy efficiency and processing speed. However, the inaccuracy of surrogate gradients and feature space quantization pose challenges for directly training deep SNN Transformers. To tackle these challenges, we propose a method (called LDD) to align ANN and SNN features across different abstraction levels in a Transformer network. LDD incorporates structured feature knowledge from ANNs to guide SNN training, ensuring the preservation of crucial information and addressing inaccuracies in surrogate gradients through designing layer-wise distillation losses. The proposed approach outperforms existing methods on the CIFAR10 (96.1%), CIFAR100 (82.3%), and ImageNet (80.9%) datasets, and enables training of the deepest SNN Transformer network using ImageNet.
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  • 文章类型: Journal Article
    今天,特殊纳米材料(NMs)和静电纺丝技术的协同组合已成为一种有希望的策略,通过开发用于污水净化和脱盐的光热膜来解决水资源短缺和能源问题。通过改变光热NMs的定位来优化膜性能,为光热真空膜蒸馏(PVMD)的膜设计提供了新的视角。聚(偏二氟乙烯)全疏光热膜通过在表面上定位氧化石墨烯纳米片(GONSh)(1)制备(0.2wt%),(2)在纳米纤维结构内(10重量%)或(3)在两个位置。考虑情况1,在暴露于1太阳强度光7分钟后,记录的最高温度(~93.5°C),这被分配给曝光后GONSh的可及性。与情况1相比,情况3的表面温度(〜90.4°C)略有降低,这表明当纳米纤维结构位于表面上时,无需将NM定位在纳米纤维结构内。另一个极端属于最低温度为71.3°C的情况2,这与辐照过程中GONSh的可及性较低是一致的。已证明,与光捕获相比,光热NM的可及性在膜表面温度中起着更明显的作用。然而,由于光热NMs的可及性增强,PVMD期间的表面温度较高,由于粘合剂阻塞了一些膜表面孔,因此渗透通量降低(情况1:1.51kg/m2h和情况2:1.83kg/m2h)抵消了。效率也遵循与通量相似的趋势。此外,对于不同的GONSh定位,未观察到排斥反应的变化。
    Today, synergistic combination of special nanomaterials (NMs) and electrospinning technique has emerged as a promising strategy to address both water scarcity and energy concerns through the development of photothermal membranes for wastewater purification and desalination. This work was organized to provide a new perspective on membrane design for photothermal vacuum membrane distillation (PVMD) through optimizing membrane performance by varying the localization of photothermal NMs. Poly(vinylidene fluoride) omniphobic photothermal membranes were prepared by localizing graphene oxide nanosheets (GO NSh) (1) on the surface (0.2 wt%), (2) within the nanofibers structure (10 wt%) or (3) in both positions. Considering the case 1, after 7 min exposure to the 1 sun intensity light, the highest temperature (∼93.5 °C) was recorded, which is assigned to the accessibility of GO NSh upon light exposure. The case 3 yielded to a small reduction in surface temperature (∼90.4 °C) compared to the case 1, indicating no need to localize NMs within the nanofibers structure when they are localized on the surface. The other extreme belonged to the case 2 with the lowest temperature of ∼71.3 °C, which is consistent with the less accessibility of GO NSh during irradiation. It was demonstrated that the accessibility of photothermal NMs plays more pronounced role in the membrane surface temperature compared to the light trapping. However, benefiting from higher surface temperature during PVMD due to enhanced accessibility of photothermal NMs is balanced out by decrease in the permeate flux (case 1: 1.51 kg/m2 h and case 2: 1.83 kg/m2 h) due to blocking some membrane surface pores by the binder. A trend similar to that for flux was also followed by the efficiency. Additionally, no change in rejection was observed for different GO NSh localizations.
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  • 文章类型: Journal Article
    配备有全疏(非润湿)膜的膜蒸馏(MD)已经发现了从高盐工业废水中回收水的利基。这里,我们检查了非氟化材料作为全疏MD膜制造表面涂层剂的功效,并确定了使用无氟材料获得最大抗湿性的必要机制。我们首先使用一系列直链烷基硅烷和聚二甲基硅氧烷(PDMS)作为代表无氟,制备了具有不同表面化学的MD膜,低表面能材料。在使用各种表面张力的给水的直接接触MD实验中,用较长链烷基硅烷改性的膜表现出较低的表面能,并表现出更高的抗湿性。尽管最长的烷基硅烷和PDMS测得的表面能几乎相同,与用最长的烷基硅烷处理的膜相比,PDMS改性的膜表现出延长的抗润湿性能。为了阐明独特的耐湿性的来源,我们通过环境扫描电子显微镜检查了具有不同表面化学的表面上的成核和冷凝动力学。我们的分析表明,用长链烷基硅烷处理的膜含有表面缺陷(即,亲水区域),而PDMS的高迁移率有效地最大限度地减少了缺陷暴露,减缓冷凝和随后的表面润湿。
    Membrane distillation (MD) equipped with omniphobic (non-wetting) membranes has found a niche in water reclamation from hypersaline industrial wastewater. Here, we examined the efficacy of non-fluorinated materials as surface coating agents for omniphobic MD membrane fabrication, and identified necessary mechanisms to attain a maximized wetting resistance using fluorine-free materials. We first prepared MD membranes with different surface chemistries using a series of linear alkylsilanes and polydimethylsiloxane (PDMS) as representative fluorine-free, low surface energy materials. Membranes modified with a longer chain alkylsilane exhibited a lower surface energy and demonstrated a greater wetting resistance in direct contact MD experiments using feedwaters of various surface tensions. Despite the nearly identical surface energy measured for the longest alkylsilane and PDMS, PDMS-modified membrane exhibited an extended antiwetting performance as compared to the membrane treated with the longest alkylsilane. To elucidate the source of the distinctive wetting resistance, we examined the nucleation and condensation kinetics on the surfaces with the different surface chemistries via environmental scanning electron microscopy. Our analysis suggests that the membranes treated with long chain alkylsilanes contain surface defects (i.e., hydrophilic regions) whereas the high mobility of the PDMS effectively minimizes the defect exposure, slowing down the condensation and subsequent surface wetting.
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  • 文章类型: Journal Article
    提取是获得药用植物有效成分的第一步,也是最重要的一步。薄荷(L.)L.作为食品和制药工业的天然原料,具有相当大的经济重要性。由于不同的提取方法(传统和现代方法)对数量的影响,该植物精油的质量和抗菌活性尚未同时完成;本研究是首次设计的,目的是根据这些特征确定最佳的提取方法。为此,用Clevenger装置(HDC)用加氢蒸馏方法提取龙叶分枝杆菌的精油,使用Kaiser装置(SDK)进行蒸汽蒸馏,用溶剂同时蒸馏(SDE),微波装置(HDM)加氢蒸馏,进行了超声波和Clevenger(UHDC)和超临界流体(SF)的预处理。通过气相色谱与质谱仪联用(GC-MS)鉴定化合物。通过琼脂扩散法评估精油对各种临床微生物菌株的抗菌活性,并确定最低抑菌浓度和最低杀菌浓度(MIC和MBC)。结果表明,黑叶香叶精油的最高和最低产量分别为HDC(1.6083%)和HDM(0.3416%)。属于SDK精油的化合物数量最高,等于72种化合物(相对百分比为87.13%),而与SF精油样品相关的化合物数量最低(7种化合物,相对百分比为100%)。哌啶酮(25.2-41.38%),哌啶酮氧化物(22.02-0%),pulegone(10.81-0%)和1,8-桉树脑(5-35.0%)是主要成分。抑菌活性结果表明,用HDM提取的精油MIC值最低,SDK,观察到SDE和U+HDC方法的值为1000μg/mL的革兰氏阴性菌志贺氏菌痢疾,比利福平弱5倍,比庆大霉素弱7倍。因此,可以得出结论,就HDC方法的效率而言,就HDM方法的化合物百分比而言,就微生物活性而言,SDK,HDM和U+HDC方法表现更好。
    Extraction is the first and most important step in obtaining the effective ingredients of medicinal plants. Mentha longifolia (L.) L. is of considerable economic importance as a natural raw material for the food and pharmaceutical industries. Since the effect of different extraction methods (traditional and modern methods) on the quantity, quality and antimicrobial activity of the essential oil of this plant has not been done simultaneously; the present study was designed for the first time with the aim of identifying the best extraction method in terms of these features. For this purpose, extracting the essential oil of M. longifolia with the methods of hydrodistillation with Clevenger device (HDC), steam distillation with Kaiser device (SDK), simultaneous distillation with a solvent (SDE), hydrodistillation with microwave device (HDM), pretreatment of ultrasonic waves and Clevenger (U+HDC) and supercritical fluid (SF) were performed. Chemical compounds were identified by gas chromatography coupled with mass spectrometer (GC-MS). Antimicrobial activity of essential oils against various clinical microbial strains was evaluated by agar diffusion method and determination of the minimum inhibitory concentration and minimum bactericidal concentration (MIC and MBC). The results showed that the highest and lowest yields of M. longifolia leaf essential oil belonged to HDC (1.6083%) and HDM (0.3416%). The highest number of compounds belonged to SDK essential oil and was equal to 72 compounds (with a relative percentage of 87.13%) and the lowest number of compounds was related to the SF essential oil sample (7 compounds with a relative percentage of 100%). Piperitenone (25.2-41.38%), piperitenone oxide (22.02-0%), pulegone (10.81-0%) and 1,8-cineole (5-35.0%) are the dominant and main components of M. longifolia essential oil were subjected to different extraction methods. Antimicrobial activity results showed that the lowest MIC value belonged to essential oils extracted by HDM, SDK, SDE and U+HDC methods with a value of 1000 μg/mL was observed against Gram-negative bacteria Shigella dysenteriae, which was 5 times weaker than rifampin and 7 times weaker than gentamicin. Therefore, it can be concluded that in terms of efficiency of the HDC method, in terms of the percentage of compounds of the HDM method, and in terms of microbial activity, the SDK, HDM and U+HDC methods performed better.
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