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1.
《Comptes Rendus Chimie》2014,17(3):261-267
Solvent extraction processes have been largely used in various industries. They recently were improved through new physical concepts such as CO2 Supercritical Fluid Extraction, Ultrasound assisted process, Microwave-assisted extraction, Instant Controlled Pressure Drop DIC-assisted extraction… Systematically, a pretreatment stage of grinding takes place in order to improve the exchange surface increasing the starting accessibility. Swelling of the material structure implies an increase of the porosity thus leading to higher solvent diffusivity within the solid matrix. A new concept of expanded granule powder has recently been defined using Instant Controlled Pressure Drop DIC technology. Whatever the type of solvent is (even CO2-SFE), such a swelled structure dramatically intensifies the kinetics through a higher specific exchange surface thanks to the open pores, while improving the solution solvent–solute diffusivity within the solid. Coupled to ultrasound, the internal transfer of solute within the pore solvent can likewise be intensified by replacing molecular diffusion within the pores by an effective convection transfer. In this work, we carried out a first approach of modeling of solvent extraction kinetics of expanded granules involving higher exchange surface and greater internal diffusion process.  相似文献   
2.
Détente Instantanée contrôlée (DIC), French for Instant Controlled Pressure Drop, was performed on laboratory apparatus as well as on a pilot plant for proving its feasibility, and identifying the optimized processing conditions and recognizing the energy consumption and the quantity of water used for such an operation. GC–MS and SPME analysis of the extracts and residue material were carried out to assess the extracts and solid residues. The lavandin essential oils obtained by using the new DIC extraction process was studied, modeled and quantitatively and qualitatively compared to the conventional hydrodistillation method. The most important differences between the two essential oils were reflected in the yields, with 4.25 as against 2.3 g EO/100 g of raw matter, and in the extraction time, with 480 s as against some hours for respectively the DIC and the hydrodistillation operations. These differences have been previewed through the fundamental analysis. They can normally explain the great decreasing of energy consumption to be 662 kWh/t of raw material. The amount of water to be added was about 42 kg water/t of raw material.  相似文献   
3.
谢利  于江  任鹏刚  刁沙沙  李爽 《分析化学》2011,(9):1368-1372
利用顶空/气相色谱-质谱(HS/GC-MS)联用法对袋装方便面印刷包装材料中7种挥发性有机物(异丙醇、乙酸乙酯、苯、乙酸丁酯、乙苯、间/对二甲苯、邻二甲苯)进行了检测分析.优化的实验参数为:平衡温度80℃,平衡时间40 min.本方法线性关系良好,7种挥发性有机物的相关系数均大于0.9991,检出限为0.004~0.0...  相似文献   
4.
陈望  陈河宏  黄琼  张视焕  刘雁彬  张琪枫 《应用声学》2016,24(5):230-233, 236
在移动互联网飞速发展的今天,即时通讯工具已经成为人们生活和工作中不可或缺的工具。但是,国内外主流的即时通讯工具依然面临着两大主要问题。一个是基于不同协议的软件的互联互通问题,另一个是日益严峻的即时通讯的安全性与隐私性问题。为了从根本上解决问题,针对即时通讯工具的特点进行了深入分析,最终设计并实现了一款基于安卓平台上更具安全性、更实用、用户体验更好的即时通讯工具SecretChat。本工具采用开放的XMPP通讯协议,并在XMPP上实现OTR安全协议。经过系统测试,系统具备稳定性并且具有良好的互联互通性能和隐私保护功能。  相似文献   
5.
Refuse tea is industrially identified as broken mixed fannings (BMF). It is a primary raw material for instant tea production. The aroma escape during the process affects the quality of instant tea used for application in the food and beverage industries. Capturing and adding back aroma to the instant tea is commercially important to overcome this drawback. Hence, the study was focused on profiling the aroma of BMF and respective instant tea based on low country (0–300 m MASL) and upcountry (>600 m MASL) elevation categories of Sri Lanka to identify the impact of growing elevation on aroma profiles to explore blending proportions for better aroma profiles. Furthermore, volatiles that escaped with steam during the instant tea production process were condensed, and this aroma extract was added back to the tea concentrate prior to spray drying to produce the aroma blended instant tea sample (ABIT). Solid-phase microextraction followed by gas chromatography–mass spectrometry was used to identify the volatile compounds in the headspace of instant tea, BMF and ABIT samples. BMF samples significantly contained linalool (9.94 ± 2.94 %), cis-linalool oxide (Furanoid) (4.69 ± 1.80 %), geraniol (2.47 ± 1.44 %), and 3-hexen-1-ol (3.46 ± 2.06 %); however, the volatile profile of instant tea samples had high amounts of hydrocarbons (51.60 ± 9.34 %) that did not contribute to creating a pleasant aroma for the product. Hexanal, geraniol, citral, cis-jasmon, α-ionone, nerol and E-2-Z-4-hexadienal are characteristic in upcountry BMF and were absent in the low country tea, indicating a difference in the aroma profiles with elevation. ABIT sample showed that there is a clear improvement in the aroma profile by retaining compounds such as linalool (5.48 %), geraniol (0.95 %), hotrienol (0.92 %), and γ-muurolene (0.22 %), which give a pleasant flowery aroma to the product. This study concluded the possibility to improve the aroma profile of instant tea to give the unique aroma of Ceylon tea as per customer requirements in an economically viable manner and this technology can be applied globally.  相似文献   
6.
以新鲜功托性保健锌蛋为原料.辅以鲜牛奶、大豆、蔗糖等配料,经不减损鸡蛋原有营养成分的科学方法加工成锌宝冲剂.经初步临床观察.本品是临床和日常饮食补充微量元素锌的保健珍品,并选用原子吸收分光光度法测定了本品微量元素锌的含量.  相似文献   
7.
We made a comprehensive investigation on the electro-optic(EO) properties of hybrid sol-gel silica film doped with Dispersed Red 1 dye(DR1/SiO2). An important finding is that the dipoles which don’t orient along the direction of corona poling field in the films can be instantaneously poled by alternate modulation electrical field. This instant poling effect results in the EO coefficients dependent on the frequency and intensity of alternate modulation electric field, and some experiments have proved it. We ...  相似文献   
8.
9.
《Arabian Journal of Chemistry》2020,13(10):7235-7246
As an intensification process of the unit operation of vegetable oil extraction, the cooking pre-treatment systematically results in damaging thermal degradations. However, recently, two thermomechanical expansion processes have been suggested and applied at industrial scales to pre-treat oilseeds: expansion and instant controlled pressure drop DIC. In both cases, it is a flash transformation from high-temperature/high-pressure to 100 °C/atmospheric pressure and 33 °C/vacuum phases, respectively. The use of DIC resulted in cumulative impact yields of 247 mg oil/g db, compared to 210, 230, and 224 for cracking, cracking/blocking, and expanding, respectively. To achieve the same yields obtained in 160 min for cracked or cracked/flaked soybean, the expander took 120 min against 35 min for DIC. Besides, thanks to the short heat treatment and the induced instant cooling, DIC allowed the highest preservation of soybean oil quality, with fatty acid concentrations almost identical to that of untreated seeds.Practical impactsIn the sector of the vegetal oil industry, researchers and engineers mostly look for increasing the extraction yields while preserving or improving the sensorial and biochemical quality of the oil. Henceforth, the modification of the oleaginous seed texture may usually be the major factor affecting and normally enhancing the capacity of extraction. Based on the improvement of material structure through adequate expansion, the higher the volume of vapor issued from the autovaporization throughout the instant controlled pressure-drop (DIC) technology, the higher the oil yields. Moreover, using the instantaneous thermodynamic theory, the feasibility of integrating DIC technology as an HTST treatment in the industrial-scale soybean extraction process could be performed and optimized without any biochemical degradation.  相似文献   
10.
采用傅里叶变换近红外光谱仪结合积分球附件对20个液体咖啡样品以漫反射方式采集近红外光谱,分别针对速溶咖啡、植脂末、糖建立定量校正模型。结果表明,速溶咖啡、植脂末、糖的模型因子数分别为4,5和4;测定系数(R2)分别为98.97%,99.94%和99.18%;校正均方根误差(root mean square error ofcalibration,RMSEC)分别为1.62,0.42和1.58;交互验证均方根误差(root mean square error of cross vali-dation,RMSECV)分别为2.12,0.72和2.01;F检验结果表明,三个模型的预测值-化学值之间存在极显著的相关关系。研究表明,近红外光谱法可以快速、准确地对液体咖啡中的三种主要成分同时进行定量测定,可为液体咖啡质量控制以及液体配方食品中具有一定组成的混合物的定量测定提供一定的参考。  相似文献   
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