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Sample records for high speed counter-current

  1. High-speed counter-current chromatographic isolation of ricinine, an insecticide from Ricinus communis.

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    Cazal, Cristiane de Melo; Batalhão, Jaqueline Raquel; Domingues, Vanessa de Cássia; Bueno, Odair Corrêa; Filho, Edson Rodrigues; Forim, Moacir R; da Silva, Maria Fátima G Fernandes; Vieira, Paulo Cezar; Fernandes, João Batista

    2009-05-08

    The alkaloid ricinine, an insecticide for leaf-cutting ant (Atta sexdens rubropilosa), was obtained from Ricinus communis. A two-phase solvent system composed of CH(2)Cl(2)/EtOH/H(2)O (93:35:72, v/v/v) was used for high-speed counter-current chromatographic (HSCCC) isolation of ricinine in high yield and with over 96% purity, as determined by liquid and gas chromatography-mass spectrometry (LC-MS and GC-MS). Identification of ricinine was performed by comparison of (1)H NMR, (13)C NMR and LC-MS/MS data.

  2. Isolation of deoxypodophyllotoxin and podophyllotoxin from Juniperus sabina by high speed counter current chromatography

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    Zhao, Y.; Yang, Y.; Chen, Q.; Kasimu, R.; Aisa, H.A.

    2016-11-01

    Deoxypodophyllotoxin and podophyllotoxin are known for their excellent anti-proliferative and anti-tumor activities, therefore large amount of pure compounds is urgently needed as authentic standards for various in vivo and in vitro studies. In this paper, an effective, rapid separation and purification method of deoxypodophyllotoxin and podophyllotoxin from the crude extract of Juniperus sabina was established using high speed counter current chromatography (HSCCC). HSCCC was performed with atwo phase solvent system comprising of n-hexane-ethylacetate-methanol-water (3:5:3:5, v/v) at the flow rate of 2mL/min at the speed of 850 rpm. 34.8 mg of deoxypodophyllotoxin and 7.9 mg of podophyllotoxin were obtained from 200 mg crude sample with a purity of 96.5% and 94.4%, respectively, as determined by high performance liquid chromatography (HPLC). (Author)

  3. Preparative Isolation of Three Anthraquinones from Rumex japonicus by High-Speed Counter-Current Chromatography

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    Shuying Guo

    2011-01-01

    Full Text Available Three anthraquinones—emodin, chrysophanol, and physcion—were successfully purified from the dichloromethane extract of the Chinese medicinal herb Rumex japonicus by high-speed counter-current chromatography (HSCCC. The extract was separated with n-hexane–ethanol–water (18:22:3, v/v/v as the two-phase solvent system and yielded 3.4 mg of emodin, 24.1 mg of chrysophanol, and 2.0 mg of physcion from 500 mg of sample with purities of 99.2 %, 98.8% and 98.2%, respectively. The HSCCC fractions were analyzed by high-performance liquid chromatography (HPLC and the chemical structures of the three anthraquinones were confirmed by 1H-NMR and 13C-NMR analysis. This is the first time these anthraquinones have been obtained from R. japonicus by HSCCC.

  4. Preparative separation of grape skin polyphenols by high-speed counter-current chromatography.

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    Luo, Lanxin; Cui, Yan; Zhang, Shuting; Li, Lingxi; Li, Yuanyuan; Zhou, Peiyu; Sun, Baoshan

    2016-12-01

    To develop an efficient method for large preparation of various individual polyphenols from white grape skins (Fernão Pires; Vitis vinifera) by preparative high-speed counter-current chromatography (HSCCC) and preparative-HPLC, an optimized preparative HSCCC condition with two-phase solvent system composed of Hex-EtOAc-H2O (1:50:50, v/v) was used to separate grape skin polyphenols into various fractions. Both the tail-head and head-tail elution modes were used with a flow rate of 3.0ml/min and a rotary speed of 950rpm. Afterwards, a preparative-HPLC separation was applied to isolate individual polyphenols in each of the fractions from HSCCC. Total of 7 fractions (Fraction A to G) were obtained from grape skin extract by HSCCC. After preparative-HPLC isolation, fifteen individual compounds were obtained, most of which presented high yields and purity (all over 90%). The HSCCC method followed with preparative-HPLC appeared to be convenient and economical, constituting an efficient strategy for the isolation of grape skin polyphenols.

  5. Preparative Separation of Phenolic Compounds from Halimodendron halodendron by High-Speed Counter-Current Chromatography

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    Zhu Yu

    2010-08-01

    Full Text Available Three phenolic compounds, p-hydroxybenzoic acid (1, isorhamnetin-3-O-β-D-rutinoside (2, and 3,3'-di-O-methylquercetin (5, along with a phenolic mixture were successfully separated from the ethyl acetate crude extract of Halimodendron halodendron by high-speed counter-current chromatography (HSCCC with chloroform-methanol-water-acetic acid (4:3:2:0.05, v/v as the two-phase solvent system. The phenolic mixture from HSCCC was further separated by preparative HPLC and purified by Sephadex LH-20 to afford quercetin (3 and 3-O-methylquercetin (4. Seven hundred mg of ethyl acetate crude extract was separated by HSCCC to obtain six fractions which were then analyzed by high performance liquid chromatography (HPLC. The HSCCC separation obtained total of 80 mg of the mixture of quercetin (3 and 3-O-methylquercetin (4 (26.43% and 71.89%, respectively in fraction 2, 14 mg of 3,3'-di-O-methylquercetin (5 at 95.14% of purity in fraction 3, 15 mg of p-hydroxybenzoic acid (1 at 92.83% of purity in fraction 5, 12 mg of isorhamnetin-3-O-β-D-rutinoside (2 at 97.99% of purity in fraction 6. This is the first time these phenolic compounds have been obtained from H. halodendron, and their chemical structures identified by means of physicochemical and spectrometric analysis.

  6. Preparative separation of cacao bean procyanidins by high-speed counter-current chromatography.

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    Li, Lingxi; Zhang, Shuting; Cui, Yan; Li, Yuanyuan; Luo, Lanxin; Zhou, Peiyu; Sun, Baoshan

    2016-11-15

    In this work, an efficient method for preparative separation of procyanidins from raw cacao bean extract by high-speed counter-current chromatography (HSCCC) was developed. Under the optimized solvent system of n-hexane-ethyl acetate-water (1:50:50, v/v/v) with a combination of head-tail and tail-head elution modes, various procyanidins fractions with different polymerization degrees were successfully separated. UPLC, QTOF-MS and (1)H NMR analysis verified that these fractions contained monomer up to pentamer respectively. Dimeric procyanidin B2 (purity>86%) could be isolated by HSCCC in a single run. Other individual procyanidins in these fractions could be further isolated and purified by preparative HPLC. The developed HSCCC together with preparative HPLC techniques appeared to be a useful tool for large preparation of different procyanidins from cacao beans. Furthermore, by antioxidant activity assays, it was proved that both fractions and individual procyanidins possessed greater antioxidant activities compared to standard trolox. The antioxidant activities of procyanidins increase as the increase of their polymerization degree. Copyright © 2016 Elsevier B.V. All rights reserved.

  7. Flat-Twisted Tubing: Novel Column Design for Spiral High-Speed Counter-Current Chromatography

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    Yang, Yi; Aisa, Haji Akber; Ito, Yoichiro

    2009-01-01

    The original spiral tube assembly for high-speed counter-current chromatography (HSCCC) is further improved by a new tube configuration called “flat-twisted tubing” which was made by extruding the tube (1.6 mm I.D.) through a narrow slot followed by twisting along its axis forming about 1 cm twisted screw pitch. This modification interrupts the laminar flow of the mobile phase through the tube and continuously mixes the two phases through the column. The performance of this spiral tube assembly was tested by three types of two-phase solvent systems with different polarity each with a set of suitable test samples such as DNP-amino acids, dipeptides and proteins at the optimal elution modes. In general all these test samples yielded higher resolution with the lower mobile phase than the upper mobile phase. In the most hydrophobic two-phase solvent system composed of hexane-ethyl acetate-metanol-0.1M hydrochloric acid (1:1:1:1, v/v), DNP-amino acids were separated with Rs-a (peak resolution based on the same column capacity adjusted for comparison) at 4.40 and 73 % of stationary phase retention at a flow rate of 0.5 ml/min with the lower mobile phase. In the polar solvent system composed of 1-butanol-acetic acid-water (4: 1: 5, v/v), dipeptide samples were resolved with Rs-a at 4.06, compared to 2.79 with the cross-pressed tube assembly at 45 % stationary phase retention, each at a flow rate of 1 ml/min. Finally in the aqueous-aqueous polymer phase systems composed of polyethylene glycol 1000 – dibasic potassium phosphate each 12.5% (w/w) in water, protein samples were resolved with Rs-a at 2.53 compared to 1.10 with the cross-pressed tube assembly at 52 % of stationary phase retention, each at a flow rate of 1 ml/min. These results indicate that the present system substantially improves the partition efficiency with a satisfactory level of stationary phase retention by the lower mobile phase. PMID:19486987

  8. Isolation of xanthyletin, an inhibitor of ants' symbiotic fungus, by high-speed counter-current chromatography.

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    Cazal, Cristiane de Melo; Domingues, Vanessa de Cássia; Batalhão, Jaqueline Raquel; Bueno, Odair Corrêa; Filho, Edson Rodrigues; da Silva, Maria Fátima G Fernandes; Vieira, Paulo Cezar; Fernandes, João Batista

    2009-05-08

    Xanthyletin, an inhibitor of symbiotic fungus (Leucoagaricus gongylophorus) of leaf-cutting ant (Atta sexdens rubropilosa), as well as suberosin, seselin and xanthoxyletin were isolated from Citrus sinensis grafted on Citrus limonia. A two-phase solvent system composed of hexane/ethanol/acetonitrile/water (10:8:1:1, v/v) was used for the high-speed counter-current chromatographic isolation of xanthyletin with high yield and over 99% purity as determined by liquid and gas chromatography with mass spectrometry detection. Identifications were performed by UV spectra, IR spectra, (1)H NMR and (13)C NMR.

  9. Preparative isolation and purification of harpagoside from Scrophularia ningpoensis hemsley by high-speed counter-current chromatography.

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    Tong, Shengqiang; Yan, Jizhong; Lou, Jianzhong

    2006-01-01

    The bioactive component harpagoside was successfully separated from the crude extract of Scrophularia ningpoensis Hemsley by one-step purification using high-speed counter-current chromatography (HSCCC). A two-phase solvent system containing n-butanol:ethyl acetate:water (1:9:10) was selected following consideration of the partition coefficient of the target compound. A 276 mg quantity of the crude extract was loaded onto a 250 mL HSCCC column and yielded 11 mg harpagoside at over 97% purity. The chemical structure of harpagoside was determined by HPLC-ESI/MS and 1H-NMR.

  10. Isolation and purification of arctigenin from Fructus Arctii by enzymatic hydrolysis combined with high-speed counter-current chromatography.

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    Liu, Feng; Xi, Xingjun; Wang, Mei; Fan, Li; Geng, Yanling; Wang, Xiao

    2014-02-01

    Enzymatic hydrolysis pretreatment combined with high-speed counter-current chromatography for the transformation and isolation of arctigenin from Fructus Arctii was successfully developed. In the first step, the extract solution of Fructus Arctii was enzymatic hydrolyzed by β-glucosidase. The optimal hydrolysis conditions were 40°C, pH 5.0, 24 h of hydrolysis time, and 1.25 mg/mL β-glucosidase concentration. Under these conditions, the content of arctigenin was transformed from 2.60 to 12.59 mg/g. In the second step, arctigenin in the hydrolysis products was separated and purified by high-speed counter-current chromatography with a two-phase solvent system composed of petroleum ether/ethyl acetate/methanol/water (10:25:15:20, v/v), and the fraction was analyzed by HPLC, ESI-MS, and (1)H NMR spectroscopy. Finally, 102 mg of arctigenin with a purity of 98.9% was obtained in a one-step separation from 200 mg of hydrolyzed sample.

  11. Enrichment and separation of antitumor triterpene acids from the epidermis of Poria cocos by pH-zone-refining counter-current chromatography and conventional high-speed counter-current chromatography.

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    Dong, Hongjing; Wu, Panpan; Yan, Renyi; Xu, Qihua; Li, Hua; Zhang, Fangbo; Li, Jianrong; Yang, Bin

    2015-06-01

    Triterpene acids were extracted from the epidermis of Poria cocos (Schw.) Wolf. These acids were found to inhibit the growth of lung cancer cells in vitro and in vivo. An efficient method for the preparative separation of antitumor triterpene acids was established that involves the combination of pH-zone-refining counter-current chromatography and conventional high-speed counter-current chromatography. We used pH-zone-refining counter-current chromatography to concentrate the triterpene acids using a two-phase solvent system composed of petroleum ether/ethyl acetate/methanol/water (3:7:5:5, v/v/v/v), trifluoroacetic acid (10 mM) was added to the upper phase as a retainer, and ammonia (10 mM) was added to the lower phase as an eluter. As a result, 200 mg concentrate of triterpene acids was obtained from 1.0 g of crude extract. The concentrate was further separated by conventional high-speed counter-current chromatography using a solvent system composed of petroleum ether/ethyl acetate/methanol/water (0.8:1.2:1.2:0.9, v/v), yielding 50 mg of poricoic acid A and 5 mg of poricoic acid B from 120 mg concentrate, respectively. The inhibitory activity of the major compound on lung A549 cells was examined and poricoic acid A was found to significantly inhibit the growth of A 549 cells.

  12. Preparative isolation and purification of xanthohumol from hops (Humulus lupulus L.) by high-speed counter-current chromatography.

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    Chen, Qi-He; Fu, Ming-Liang; Chen, Miao-Miao; Liu, Jing; Liu, Xiao-Jie; He, Guo-Qing; Pu, Shou-Cheng

    2012-05-01

    Xanthohumol (XN) and related prenylflavonoids are the main bioactive components of hops (Humulus lupulus L.). The current work is to investigate the use of high-speed counter-current chromatography (HSCCC) in search for high isolation of xanthohumol from hops. A solvent system consisted of n-hexane-ethyl acetate-methanol-water at a volume ratio of 5:5:4:3 was employed. The results demonstrated that the constructed method could be well applied for the isolation of xanthohumol from hops extract. After HSCCC isolation procedure, the purity of xanthohumol was over 95% assayed by HPLC and the yield of extraction was 93.60%. The chemical structure identification of xanthohumol was carried out by UV, (1)H NMR and (13)C NMR. The present results demonstrated that xanthohumol could be efficiently obtained using a single HSCCC step from H. lupulus L. extract.

  13. Preparative separation of isovitexin and isoorientin from Patrinia villosa Juss by high-speed counter-current chromatography.

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    Peng, Jinyong; Fan, Guorong; Hong, Zhanying; Chai, Yifeng; Wu, Yutian

    2005-05-13

    High-speed counter-current chromatography (HSCCC) with a solvent system composed of ethyl acetate-n-butanol-water (2:1:3, v/v/v) was used to isolate and separate two C-glycosylflavones from Patrinia villosa Juss, a traditional Chinese medicine. The separation produced 42.9 mg isovitexin and 20.1 mg isoorientin with purities of 99.3% and 98.5%, respectively as determined by high-performance liquid chromatography (HPLC) in one step elution from 250 mg crude extract, and identification was performed by MS, 1H NMR and 13C NMR. It is the first report of discovering isovitexin and isoorientin from the plant of Patrinia genus.

  14. Separation and purification of astaxanthin from Phaffia rhodozyma by preparative high-speed counter-current chromatography.

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    Du, Xiping; Dong, Congcong; Wang, Kai; Jiang, Zedong; Chen, Yanhong; Yang, Yuanfan; Chen, Feng; Ni, Hui

    2016-09-01

    An effective high-speed counter-current chromatography (HSCCC) method was established for the preparative isolation and purification of astaxanthin from Phaffia rhodozyma. With a two-phase solvent system composed of n-hexane-acetone-ethanol-water (1:1:1:1, v/v/v/v), 100mg crude extract of P. rhodozyma was separated to yield 20.6mg of astaxanthin at 92.0% purity. By further one step silica gel column chromatography, the purity reached 99.0%. The chemical structure of astaxanthin was confirmed by thin layer chromatography (TLC), UV spectroscopy scanning, high performance liquid chromatography with a ZORBAX SB-C18 column and a Waters Nova-pak C18 column, and ESI/MS/MS.

  15. Isolation and Purification of Oridonin from the Whole Plant of Isodon rubescens by High-Speed Counter-Current Chromatography

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    ChunYue Yu

    2011-09-01

    Full Text Available Semi-preparative high-speed counter-current chromatography (HSCCC was successfully used for isolation and purification of oridonin from Isodon rubescens by using a two-phase-solvent system composed of n-hexane-ethyl acetate-methanol-water (2.8:5:2.8:5, v/v/v/v. The targeted compound isolated, collected and purified by HSCCC was analyzed by high performance liquid chromatography (HPLC. A total of 40.6 mg of oridonin with the purity of 73.5% was obtained in less than 100 min from 100 mg of crude Isodon rubescens extract. The chemical structure of the compound was identified by IR, 1H-NMR and 13C-NMR.

  16. Preparative isolation of guaipyridine sesquiterpene alkaloid from Artemisia rupestris L. flowers using high-speed counter-current chromatography.

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    Su, Zhen; Wu, Hankui; Yang, Yi; Aisa, Haji Akber; Slukhan, Usmanova; Aripova, Salimakhon

    2008-07-01

    Although the medicinal plant Artemisia rupestris L. has been widely researched for several decades, its alkaloids have never been isolated before. To our surprise, the alkaloids in the plant were not detected in the stems but detected in the flowers. Herein, a novel and strange guaipyridine sesquiterpene alkaloid with a carboxyl group named rupestine was purified successfully from the total alkaloids extracted from the flowers by high-speed counter-current chromatography (HSCCC). The two-phase solvent system used was composed of ethyl acetate-methanol-water (8:1:7, v/v/v). Fifty six milligrams of rupestine was obtained at over 97% purity and 95% recovery from 200 mg of the total alkaloids in one-step separation. Its structure was elucidated by spectroscopic methods including high resolution ESI-MS, (1)H NMR, (13)C NMR, Heteronuclear Multiple Bond Correlation (HMBC), Heteronuclear Single Quantum Coherence (HSQC), and Nuclear Overhauser Enhancement Spectroscopy (NOESY).

  17. Isolation and purification of orientin and vitexin from Trollius chinensis Bunge by high-speed counter-current chromatography.

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    Yu, Xiao-Xue; Huang, Jie-Yun; Xu, Dan; Xie, Zhi-Yong; Xie, Zhi-Sheng; Xu, Xin-Jun

    2014-01-01

    Orientin and vitexin are the two main bioactive compounds in Trollius chinensis Bunge. In this study, a rapid method was established for the isolation and purification of orientin and vitexin from T. chinensis Bunge using high-speed counter-current chromatography in one step, with a solvent system of ethyl acetate-ethanol-water (4:1:5, v/v/v). A total of 9.8 mg orientin and 2.1 mg vitexin were obtained from 100 mg of the ethyl acetate extract, with purities of 99.2% and 96.0%, respectively. Their structures were identified by UV, MS and NMR. The method was efficient and convenient, which could be used for the preparative separation of orientin and vitexin from T. chinensis Bunge.

  18. Simultaneous preparation of naturally abundant and rare catechins by tannase-mediated biotransformation combining high speed counter current chromatography.

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    Xia, Guobin; Hong, Shan; Liu, Songbai

    2014-05-15

    Simultaneous preparation of naturally rare catechins, EGC and EC, has been realized by tannase-mediated biotransformation combining high speed counter current chromatography. In addition, simultaneous preparation of the four catechins, EGCG, ECG, EGC, and EC in green tea extract has also been achieved by HSCCC under the normal phase and the reversed phase modes. The identity of the catechins was determined by HPLC-DAD-ESI-MS and quantification of the catechins was performed by HPLC-DAD. In a typical HSCCC separation, 27.2 mg 98.8% EGCG, 14.1 mg 94.7% EGC, and 9.3 mg 97.5% EC were obtained. This new method is efficient, time-saving and valuable for biological studies.

  19. [Isolation and preparation of gallic acid from Terminalia chebula Retz. with high-speed counter-current chromatography].

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    Li, Zhongqin; Li, Qiuyun; Jiang, Xinglong; Zhang, Kun; Guan, Ruizhang

    2014-12-01

    A separation method based on high-speed counter-current chromatography (HSCCC) has been established for the isolation and preparation of gallic acid from the ethanol extract of Terminalia chebula Retz. After comparing five kinds of solvent protocols of HSCCC, the two-phase system of n-hexane-ethyl acetate-methanol-water (1:5:1:5, v/v/v/v) was finally chosen as the operating solvent of HSCCC for the separation of gallic acid, in which the lower phase was used as the mobile phase and the upper phase as stationary phase. The detection in the experiments was performed with an ultraviolet detector at 254 nm. Under the conditions of rotation speed of 850 r/min, lower phase flow rate of 2 mL/min, four peaks (I/II/III/IV) were displayed on HSCCC chromatogram. Among them, only peak III contained a large amount of gallic acid (about 96. 40%), which was confirmed by electrospray ionization mass spectrometry (ESI-MS) and high performance liquid chromatographic (HPLC) analysis. As much as 8. 6 mg of gallic acid was obtained from 100 mg of the ethanol extract of Terminalia chebula Retz., indicating the method is simple, robust and efficient for the preparation of gallic acid.

  20. Separation and purification of glucosinolates from crude plant homogenates by high-speed counter-current chromatography.

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    Fahey, Jed W; Wade, Kristina L; Stephenson, Katherine K; Chou, F Edward

    2003-05-01

    Glucosinolates are anionic, hydrophilic plant secondary metabolites which are of particular interest due to their role in the prevention of cancer and other chronic and degenerative diseases. The separation and purification of glucosinolates from a variety of plant sources (e.g. seeds of broccoli, arugula and the horseradish tree), was achieved using high-speed counter-current chromatography (HSCCC). A high-salt, highly polar system containing 1-propanol-acetonitrile-saturated aqueous ammonium sulfate-water (1:0.5:1.2:1), was run on a semi-preparative scale and then transferred directly to preparative scale. Up to 7 g of a concentrated methanolic syrup containing about 10% glucosinolates was loaded on an 850-ml HSCCC column, and good separation and recovery were demonstrated for 4-methylsulfinylbutyl, 3-methylsulfinylpropyl, 4-methylthiobutyl, 2-propenyl and 4-(rhamnopyranosyloxy)benzyl glucosinolates. Multiple injections (5 to 6 times) were performed with well-preserved liquid stationary phase under centrifugal force. Pooled sequential runs with broccoli seed extract yielded about 20 g of its predominant glucosinolate, glucoraphanin, which was produced at > 95% purity and reduced to powdered form.

  1. Preparative purification of five bioactive components from Agrimonia pilosa Ledeb by high-speed counter-current chromatography.

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    Wang, Yan; Liu, Mozhen; Zheng, Lingli; Yin, Lianhong; Xu, Lina; Qi, Yan; Ma, Xiaochi; Liu, Kexin; Peng, Jinyong

    2012-08-01

    High-speed counter-current chromatography (HSCCC) coupled with ultraviolet (UV) detection or evaporative light-scattering detection was successfully applied for preparative separation of five bioactive compounds from Agrimonia pilosa Ledeb. In preliminary process, D101 macroporous resin was used to separate the crude extract of the plant and four fractions (20, 40, 50, and 60% aqueous ethanol elutions) were produced. Then, these fractions were directly subjected to HSCCC purification. Five chemicals including taxifolin-3-glucoside (6.4 mg), quercetin-3-rhamnoside (13.0 mg), tiliroside (14.7 mg), agrimonolide (21.4 mg), and tormentic acid (29.8 mg) with the purities of 94.24, 95.37, 97.42, 95.29, and 96.34% were separated from each 200 mg prepared fraction. The purities were analyzed by high-performance liquid chromatography, and the chemical structures of the products were identified by UV detection, mass spectrometry, nuclear magnetic resonance, and the standards. This paper used a simple method to separate five bioactive compounds from A. pilosa Ledeb, and it could provide a new idea for the purification of bioactive compounds from other medicinal plants.

  2. Separation of phenolic acids and flavonoids from Trollius chinensis Bunge by high speed counter-current chromatography.

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    Qin, Yanhua; Liang, Yizeng; Ren, Dabing; Qiu, Ximin; Li, Xi

    2015-09-15

    In this work, eleven compounds were successfully separated from Trollius chinensis Bunge by using a two-step high-speed counter-current chromatography (HSCCC) method. NRTL-SAC (nonrandom two-liquid segment activity coefficient) method, a newly developed solvent system selection strategy, was applied to screening the suitable biphasic liquid systems. Hexane/ethyl acetate/ethanol/water (3:7:3:7, v/v) solvent system was used in the first step, while the hexane/ethyl acetate/methanol/water (1:2:1:2, 1:4:1:4, 1:9:1:9, v/v) systems were employed in the second step. The chemical structures of the separated compounds were identified by UV, high resolution ESI-MS and MS/MS data. The separated compounds are 3,4-dihydroxyphenylethanol (1), vanillic acid (2), orientin (3), vitexin (4), veratric acid (5), 2″-O-(3‴, 4‴-dimethoxybenzoyl) orientin (6), 2″-O-feruloylorientin (7), 2″-O-feruloylvitexin (8), 2″-O-(2‴-methylbutyryl) vitexin (9), 2″-O-(2‴-methylbutyryl) isoswertiajaponin (10), 2″-O-(2‴-methylbutyryl) isoswertisin (11). The results demonstrate that HSCCC is a powerful tool for the separation of compounds from extremely complex samples.

  3. Preparative Separation of Spirobisnaphthalenes from Endophytic Fungus Berkleasmium sp. Dzf12 by High-Speed Counter-Current Chromatography

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    Ligang Zhou

    2013-10-01

    Full Text Available High-speed counter-current chromatography (HSCCC was applied for the first time for the preparative separation of spirobisnaphthalenes from a crude extract of the endophytic fungus Berkleasmium sp. Dzf12, associated with the medicinal plant Dioscorea zingiberensis. Six spirobisnaphthalenes were successfully separated by HSCCC with a two-phase solvent system composed of n-hexane-chloroform-methanol-water (1.5:3.0:2.5:2.0, v/v. About 18.0 mg of diepoxin k (1, 245.7 mg of palmarumycin C13 (2, 42.4 mg of palmarumycin C16 (3, 42.2 mg of palmarumycin C15 (4, 32.6 mg of diepoxin δ (5, and 22.3 mg of diepoxin γ (6 with purities of 56.82, 71.39, 76.57, 75.86, 91.01 and 82.48%, respectively, as determined by high-performance liquid chromatography (HPLC, were obtained from 500 mg of the crude extract in a one-step elution within 7 h of separation procedure by HSCCC. The purified spirobisnaphthalenes were further structurally characterized by means of physicochemical and spectrometric analysis.

  4. Preparative separation of six antimycin A components from antimycin fermentation broth by high-speed counter-current chromatography.

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    Wang, Jiaoyan; Wen, Yaoming; Chen, Xiuming; Lin, Yuhan; Zhou, Jingming; Xie, Ying; Wang, Huaiwang; Jiang, Hong; Zheng, Wei

    2010-09-03

    A method of using high-speed counter-current chromatography (HSCCC) was established for preparative isolation and purification of antimycin A components from antimycin fermentation broth. Six antimycin A components were successfully purified for the first time by HSCCC with a two-phase solvent system composed of n-hexane-ethyl acetate-methanol-water (5:2:4:1, by volume). Total of 20mg antimycin A(4)(a or b), 25mg antimycin A(3)(a or b), 21mg antimycin A(8)(a or b), 34mg antimycin A(2)(a or b), 26mg antimycin A(1)(a or b) and 34mg antimycin A(1)(a or b) with the purities of 93.2, 98.6, 96.2, 94.1, 94.9 and 96.7%, respectively, determined by high-performance liquid chromatography (HPLC), were yielded from 200mg crude sample only in one HSCCC run. 2010 Elsevier B.V. All rights reserved.

  5. [Isolation and purification of diarylheptanoids from Alpinia officinarum Hance by high-speed counter-current chromatography].

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    Ye, Qiongxian; Tan, Xiong; Zhu, Longping; Zhao, Zhimin; Yang, Depo; Yin, Sheng; Wang, Dongmei

    2012-03-01

    Three diarylheptanoids were isolated and purified from Alpinia officinarum Hance by high-speed counter-current chromatography (HSCCC). A two-phase solvent system composed of hexane-ethyl acetate-methanol-water (2: 3: 1.75: 1, v/v/v/v) was used. The lower phase was used as the stationary phase. From 122.20 mg petroleum ether extract of A. officinarum, 5R-hydroxy-7-(4-hydroxy-3-methoxyphenyl )-1-phenyl-3-heptanone (7.37 mg), 7-(4-hydroxy-3-methoxyphenyl)-1-phenyl-4E-en-3-heptanone (9.11 mg) and 1,7-diphenyl-4E-en-3-heptanone (15.44 mg) with purities over 93% were obtained within 140 min in one-step separation by HSCCC under the conditions of a flow rate of 1.5 mL/min and 858 r/min. The obtained compounds were analyzed by high performance liquid chromatography to provide their purities, and their structures were confirmed by using mass spectrometry, 1H-nuclear magnetic resonance (1H-NMR) and 13C-NMR. The established HSCCC method is relatively simple, fast and suitable for the isolation and purification of diarylheptanoids from A. officinarum.

  6. Preparative separation of polyphenols from artichoke by polyamide column chromatography and high-speed counter-current chromatography

    Energy Technology Data Exchange (ETDEWEB)

    Shu, Xikai; Wang, Mei; Liu, Daicheng [College of Life Science, Shandong Normal University, Jinan, Shandong (China); Wang, Daijie; Lin, Xiaojing; Liu, Jianhua; Wang, Xiao; Huang, Luqi, E-mail: wxjn1998@126.com [Shandong Analysis and Test Center, Shandong Academy of Sciences, Jinan, Shandong (China)

    2013-09-01

    An efficient method for the rapid separation and purification of polyphenols from artichoke by polyamide column chromatography in combination with high-speed counter-current chromatography (HSCCC) was successfully built. The crude ethanol extracts from dry artichoke were first pre-separated by polyamide column chromatography and divided in two parts as sample 1 and sample 2. Then, the samples were further separated by HSCCC and yielded 7.8 mg of chlorogenic acid (compound I), 24.5 mg of luteolin-7-O-{beta}-D-rutinoside (compound II), 18.4 mg of luteolin-7-O-{beta}-D-glucoside (compound III), and 33.4 mg of cynarin (compound IV) with purity levels of 92.0%, 98.2%, 98.5%, and 98.0%, respectively, as determined by high-performance liquid chromatography (HPLC) method. The chemical structures of these compounds were identified by electrospray ionization-mass spectrometry (ESI-MS) and nuclear magnetic resonance (NMR). (author)

  7. Extraction and preparative purification of tanshinones from Salvia miltiorrhiza Bunge by high-speed counter-current chromatography.

    Science.gov (United States)

    Sun, Ailing; Zhang, Yongqing; Li, Aifeng; Meng, Zhaoling; Liu, Renmin

    2011-07-01

    A method for extraction and preparative separation of tanshinones from Salvia miltiorrhiza Bunge was successfully established in this paper. Tanshinones from Salvia miltiorrhiza Bunge were extracted using ethyl acetate as the extractant under reflux. The extracts were then purified by high speed counter-current chromatography (HSCCC) with light petroleum-ethyl acetate-methanol-water (6:4:6.5:3.5, v/v) as the two phase solvent system. The upper phase was used as the stationary phase and the lower phase as the mobile phase. 8.2mg of dihydrotanshinone I, 5.8 mg of 1,2,15,16-tetrahydrotanshiquinone, 26.3mg of cryptotanshinone, 16.2mg of tanshinone I, 25.6 mg of neo-przewaquinone A, 68.8 mg of tanshinone IIA and 9.3mg of miltirone were obtained from 400mg of extracts from Salvia miltiorrhiza Bunge in one-step HSCCC separation, with the purity of 97. 6%, 95.1%, 99.0%, 99.1%, 93.2%, 99.3% and 98.7%, respectively, as determined by HPLC area normalization method. Their chemical structures were identified by ¹H NMR.

  8. Isolation of secondary metabolites from Hortia oreadica (Rutaceae) leaves through high-speed counter-current chromatography.

    Science.gov (United States)

    Severino, Vanessa Gisele Pasqualotto; Cazal, Cristiane de Melo; Forim, Moacir Rossi; da Silva, Maria Fátima das Graças Fernandes; Rodrigues-Filho, Edson; Fernandes, João Batista; Vieira, Paulo Cezar

    2009-05-08

    High-speed counter-current chromatography (HSCCC) with a two-phase solvent system (hexane-ethanol-acetonitrile-water 10:8:1:1, v/v) was applied to examine the leaves of Hortia oreadica, which afforded the known limonoid guyanin (1), the alkaloids rutaecarpin (2) and dictamnine (6), the dihydrocinnamic acid derivatives methyl 5,7-dimethoxy-2,2-dimethyl-2H-1-benzopyran-6-propanoate (3), 5,8-dimethoxy-2,2-dimethyl-2H-1-benzopyran-6-propanoic acid (4), together with the new E-3,4-dimethoxy-alpha(3-hydroxy-4-carbomethoxyphenyl)cinnamic acid (5). The recovery of compounds 1-6 was determined by comparison with LC-atmospheric pressure chemical ionization MS/MS data: 66.2%, 93.1%, 102.5%, 101.2%, 99.0% and 84.9%, respectively. Compound 3 showed IC(50) of 23.6microM against Plasmodium falciparum and 15.6microM against Trypanosoma brucei rhodesienses and was not toxic to KB cells (IC(50)>100microM).

  9. Purification of two triterpenoids from Schisandra chinensis by macroporous resin combined with high-speed counter-current chromatography.

    Science.gov (United States)

    Zhu, Lijie; Li, Bin; Liu, Xiuying; Meng, Xianjun

    2014-10-01

    A method for preparative purification of corosolic acid and nigranoic acid from Schisandra chinensis (SC) was established using a combination of macroporous absorption resin column separation and high-speed counter-current chromatography (HSCCC). The crude extracts obtained from SC using 70% ethanol were separated on a macroporous resin column and then eluted with a graded ethanol series. The 70% ethanol fraction was used as the sample for separation of the two triterpenoids by HSCCC. The two-phase solvent system used for HSCCC separation was chloroform-n-butanol-methanol-water (10:0.5:7:4, v/v/v/v). The upper phase was used as the stationary phase of HSCCC. Corosolic acid (16.4 mg) of 96.3% purity and nigranoic acid (9.5 mg) of 98.9% purity were obtained in a one-step HSCCC separation from 100 mg of the sample. The structures of corosolic acid and nigranoic acid were identified by (1)H-nuclear magnetic resonance (NMR) and (13)C-NMR.

  10. Enantioseparation of racemic trans-δ-viniferin using high speed counter-current chromatography based on induced circular dichroism technology.

    Science.gov (United States)

    Han, Chao; Xu, Jinfang; Wang, Xiaobing; Xu, Xiaoming; Luo, Jianguang; Kong, Lingyi

    2014-01-10

    A preparative chiral high speed counter-current chromatography (HSCCC) method based on induced circular dichroism (ICD) spectrum was developed to separate trans-δ-viniferin (TVN) enantiomers successfully. The important parameters for the chiral HSCCC separation process, including the type of chiral selector (CS), the concentration of chiral selector and the equilibrium temperature, were optimized using induced circular dichroism spectrum. The final separation procedure was established with a biphasic solvent system composed of n-hexane-ethyl acetate-25 mmol L(-1) hydroxypropyl-β-cyclodextrin aqueous solution (5:5:10, v/v/v) in the head-to-tail elution mode at 5 °C. Under optimum chiral HSCCC separation conditions, 8.2mg of (7S, 8S)-TVN (1) and 9.4 mg of (7R, 8R)-TVN (2) were successfully separated from 20mg TVN enantiomers with the purity of 99.51% and 99.36%, respectively. Copyright © 2013 Elsevier B.V. All rights reserved.

  11. Isolation and purification of seven lignans from Magnolia sprengeri by high-speed counter-current chromatography.

    Science.gov (United States)

    Sun, Yu; Yu, Zongyuan; Duan, Wenjuan; Fang, Lei; Xu, Shuangshuang; Wang, Xiao

    2011-12-01

    Seven lignans including (-)-maglifloenone, futoenone, magnoline, cylohexadienone, fargesone C, fargesone A and fargesone B were isolated and purified from Magnolia sprengeri Pamp. using high-speed counter-current chromatography (HSCCC) with two-step separation. In the first step, a stepwise elution mode with the two-phase solvent system composed of petroleum ether-ethyl acetate-methanol-water (1:0.8:0.6:1.2, 1:0.8:0.8:1, v/v) was used and 15.6 mg of (-)-maglifloenone, 19.2 mg of futoenone, 10.8 mg of magnoline, 14.7 mg of cylohexadienone and 217 mg residues were obtained from 370 mg crude extract. In the second step, the residues were successfully separated by HSCCC with the solvent system composed of petroleum ether-ethyl acetate-methanol-water (1:0.8:1.2:0.6, v/v), yielding 33.2 mg of fargesone C, 47.5 mg of fargesone A and 17.7 mg of fargesone B. The purities of the separated compounds were all over 95% determined by HPLC. The chemical structures of these compounds were confirmed by (1)H NMR, (13)C NMR and ESI-MS. Copyright © 2011 Elsevier B.V. All rights reserved.

  12. Separation and purification of four compounds from Desmodium styracifolium using off-line two-dimensional high-speed counter-current chromatography.

    Science.gov (United States)

    Su, Wen; Liu, Qi; Yang, Qing; Yu, Jingang; Chen, Xiaoqing

    2013-10-01

    An off-line 2D high-speed counter-current chromatography technique in preparative scale has been successfully applied to separate and purify the main compounds from the ethyl acetate extract of Desmodium styracifolium. A two-phase solvent system composed of n-hexane/ethyl acetate/methanol/water at an optimized volume ratio of 1:2:1:2 v/v/v/v was used. Conventional high-speed counter-current chromatography was used as the first dimension, and the upper phase of the solvent system was used as the stationary phase in the head-to-tail elution mode at a flow rate of 2.0 mL/min and a rotation speed of 900 rpm. Recycling high-speed counter-current chromatography served as the second dimension to separate an impure fraction of the first dimension. A total of four well-separated substances including vanillic acid (1), β-sitosterol (2), formononetin (3), and aromadendrin (4) were obtained, and their purities and structures were identified by HPLC-MS and (1) H NMR spectroscopy. The results illustrated that off-line 2D high-speed counter-current chromatography is an effective way to isolate compounds in complex samples.

  13. Preparative isolation and purification of two benzoxazinoid glucosides from Acanthus ilicifolius L. by high-speed counter-current chromatography.

    Science.gov (United States)

    Yin, Hao; Zhang, Si; Luo, Xiongming; Liu, Yonghong

    2008-09-26

    The first preparative separation of two benzoxazinoids, (2R)-2-O-beta-d-glucopyranosyl-2H-1,4-benzoxazin-3(4H)-one (HBOA-Glc) and (2R)-2-O-beta-d-glucopyranosyl-4-hydroxy-2H-1,4-benzoxazin-3(4H)-one (DIBOA-Glc), by means of high-speed counter-current chromatography (HSCCC) from the n-butanol extract of Acanthus ilicifolius L. is presented. The two-phase solvent system containing ethyl acetate-n-butanol-0.5%NH(4)OH (2:3:5, v/v/v, system B) was selected for the one-step HSCCC separation of HBOA-Glc and DIBOA-Glc according to the partition coefficient values (K) for target compounds and the separation factor (alpha) between the two target compounds. In the one-step HSCCC separation using solvent B, from 100mg n-butanol extract of A. ilicifolius, 6.3 mg HBOA-Glc and 6.8 mg DIBOA-Glc were isolated with purities of 90.3% and 80.2%, respectively. In order to obtain the two target compounds with higher purity, a second separation process was developed comprising two steps. In the two-step separation, the sample was first pre-purified by HSCCC using ethyl acetate-n-butanol-water (2:3:5, v/v/v, system A) solvent system and then purified using solvent system B. A 100-mg amount of the n-butanol extracts of A. ilicifolius was separated to yield 5.8 mg of HBOA-Glc and 4.8 mg of DIBOA-Glc with purities of 97.1% and 94.8%, respectively, which were directly used for NMR analyses.

  14. Preparative Separation of Main Ustilaginoidins from Rice False Smut Balls by High-Speed Counter-Current Chromatography

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    Weibo Sun

    2016-01-01

    Full Text Available Ustilaginoidins are bis-naphtho-γ-pyrone mycotoxins isolated from the rice false smut balls (FSBs infected by the pathogen Villosiclava virens in rice spikelets on panicles. In order to obtain large amounts of pure ustilaginoidins to further evaluate their biological activities and functions, phytotoxicity on rice, security to human and animals as well as to accelerate their applications as pharmaceuticals, preparative high-speed counter-current chromatography (HSCCC was successfully applied to the isolation and purification of seven bis-naphtho-γ-pyrone mycotoxins, namely ustilaginoidins A (1, G (2, B (3, H (4, I (5, C (6, and J (7 from the ethyl acetate crude extract of rice FSBs. Both 1 and 2 were prepared by HSCCC from the low-polarity fraction of the crude extract using the two-phase solvent system composed of n-hexane-ethyl acetate-methanol-water at the volume ratio of 6.5:3.5:5.0:5.0. Similarly, 3, 4 and 5 were prepared from the medium-polarity fraction using the system at the volume ratio of 4.0:5.0:5.0:6.0, and 6 and 7 were prepared from the higher-polarity fraction using the system at volume ratio of 3.0:5.0:4.0:6.7. A total of 6.2 mg of 1, 5.1 mg of 2, 3.9 mg of 3, 1.2 mg of 4, 5.7 mg of 5, 3.5 mg of 6, and 6.1 mg of 7 with purities of 88%, 82%, 91%, 80%, 92%, 81% and 83%, respectively, were yielded from total 62 mg fraction samples in three independent HSCCC runs. The structures of the purified ustilaginoidins were characterized by means of physicochemical and spectrometric analysis.

  15. Isolation of all-trans lycopene by high-speed counter-current chromatography using a temperature-controlled solvent system.

    Science.gov (United States)

    Baldermann, Susanne; Ropeter, Katharina; Köhler, Nils; Fleischmann, Peter

    2008-05-23

    The effect of solvent system, partition coefficient, retention of stationary phase, column, revolution speed, and flow rate of mobile phase are well known parameters to effect HSCCC (high-speed counter-current chromatography) separations. Temperature effects on chromatographic techniques like HPLC and GC are well studied, but the influence of temperature on CCC solvent systems is hardly investigated. This paper presents the influence of temperature on several key parameters (partition coefficient, settling time, volume ratios) in the hydrophobic HSCCC solvent system hexane:dichloromethane:acetonitrile (30:11:18, v/v/v) used for the isolation of lycopene from tomato paste at 10, 15, 20 and 25 degrees C.

  16. Purification of six lignans from the stems of Schisandra chinensis by using high-speed counter-current chromatography combined with preparative high-performance liquid chromatography.

    Science.gov (United States)

    Zhu, Lijie; Li, Bin; Liu, Xiuying; Huang, Guohui; Meng, Xianjun

    2015-11-01

    A method for the preparative purification of lignans from Schisandra chinensis was established using a combination of high-speed counter-current chromatography (HSCCC) and preparative high-performance liquid chromatography (HPLC). The crude extracts obtained from S. chinensis by using 70% ethanol were separated on a macroporous resin column and then eluted with a graded ethanol series. A two-phase solvent system consisting of n-hexane-ethyl acetate-methanol-water (1:1:1:1, v/v) was used for HSCCC, and a mobile phase of acetonitrile-water (50:50, v/v) was used for preparative HPLC. The results obtained using HSCCC were compared with those obtained using preparative HPLC, and their advantages were further integrated to improve the separation efficiency. Six known lignans were identified by electrospray ionisation mass spectrometry and (1)H nuclear magnetic resonance (NMR) and (13)C NMR analyses; the purities of all the compounds were more than 91%.

  17. Preparative separation of bioactive compounds from essential oil of Flaveria bidentis (L.) Kuntze using steam distillation extraction and one step high-speed counter-current chromatography.

    Science.gov (United States)

    Wei, Yun; Du, Jilin; Lu, Yuanyuan

    2012-10-01

    In order to utilize and control the invasive weed, bioactive compounds from essential oil of Flaveria bidentis (L.) Kuntze were studied. Steam distillation extraction and one step high-speed counter-current chromatography were applied to separate and purify the caryophyllene oxide, 7,11-dimethyl-3-methylene-1,6,10-dodecatriene, and caryophyllene from essential oil of Flaveria bidentis (L.) Kuntze. The two-phase solvent system containing n-hexane/acetonitrile/ethanol (5:4:3, v/v/v) was selected for the one step separation mode according to the partition coefficient values (K) of the target compounds and the separation factor (α). The purity of each isolated fraction after a single high-speed counter-current chromatography run was determined by high performance liquid chromatography. A 3.2 mg of caryophyllene oxide at a purity of 92.6%, 10.4 mg of 7,11-dimethyl-3-methylene-1,6,10-dodecatriene at a purity of 99.1% and 5.7 mg of caryophyllene at a purity of 98.8% were obtained from 200 mg essential oil of Flaveria bidentis (L.) Kuntze. The chemical structures of these components were identified by GC-MS, (1) H-NMR, and (13) C-NMR.

  18. Three-phase solvent systems for the comprehensive separation of a wide variety of compounds from Dicranostigma leptopodum by high-speed counter-current chromatography.

    Science.gov (United States)

    Liu, Yanjuan; Chen, Xiaofen; Liu, JunXi; Di, Duolong

    2015-06-01

    A three-phase solvent system was efficiently applied for high-speed counter-current chromatography to separate secondary metabolites with a wide range of hydrophobicity in Dicranostigma leptopodum. The three-phase solvent system of n-hexane/methyl tert-butyl ether/acetonitrile/0.5% triethylamine (2:2:3:2, v/v/v/v) was selected for high-speed counter-current chromatography separation. The separation was initiated by filling the column with a mixture of intermediate phase and lower phase as a stationary phase followed by elution with upper phase to separate the hydrophobic compounds. Then the mobile phase was switched to the intermediate phase to elute the moderately hydrophobic compounds, and finally the polar compounds still retained in the column were fractionated by eluting the column with the lower phase. In this research, 12 peaks were eluted out in one-step operation within 110 min, among them, eight compounds with acceptable purity were obtained and identified. The purities of β-sitosterol, protopine, allocryptopine, isocorydione, isocorydine, coptisine, berberrubine, and berberine were 94.7, 96.5, 97.9, 86.6, 98.9, 97.6, 95.7, and 92.8%, respectively.

  19. Single-step purification of dracorhodin from dragon's blood resin of Daemonorops draco using high-speed counter-current chromatography combined with pH modulation.

    Science.gov (United States)

    Shi, Jianmei; Hu, Ruilin; Lu, Yanbin; Sun, Cuirong; Wu, Tianxing

    2009-12-01

    Dracorhodin is a major constituent found in "Dragon's blood" resin of Daemonorops draco Willd. Blume. This natural flavylium compound is a potent pharmaceutical substance due to its biological and pharmacological activities such as antimicrobial, antiviral, antitumor and cytotoxic activity. An effective high-speed counter-current chromatography method was successfully established for the isolation and purification of dracorhodin directly from extract of D. draco by using a two-phase solvent system composed of n-hexane/ethyl acetate/methanol/water (2:3:2:3 v/v). Under the optimal conditions, 6.6 mg dracorhodin was obtained from 100 mg crude resin. The isolated fraction of counter-current chromatography was determined by HPLC, NMR, UV/visible and ESI/MS combined with pH modulation, since dracorhodin is unstable in solution which exists in different forms depending on pH values. The data were compared with those of the reference substance, and the literatures as well. The purity of dracorhodin was over 98% based on the HPLC result.

  20. Separation and purification of three stilbenes from the radix of Polygonum cillinerve (Nakai Ohwl by macroporous resin column chromatography combined with high-speed counter-current chromatography

    Directory of Open Access Journals (Sweden)

    Xiaofeng Chi

    2014-01-01

    Full Text Available An effective method for the rapid separation and purification of three stilbenes from the radix of Polygonum cillinerve (Nakai Ohwl by macroporous resin column chromatography combined with high-speed counter-current chromatography (HSCCC was successfully established. In the present study, a two-phase solvent system composed of chloroform-n-butanol-methanol-water (4:1:4:2, v/v/v/v was used for HSCCC separation. A one-step separation in 4 h from 150 mg of crude extract produced 26.3 mg of trans-resveratrol-3-O-glucoside, 42.0 mg of pieceid-2"-O-gallate, and 17.9 mg of trans-resveratrol with purities of 99.1%, 97.8%, and 99.4%, respectively, as determined by high-performance liquid chromatography (HPLC. The chemical structures of these compounds were identified by nuclear magnetic resonance (NMR spectroscopy.

  1. Preparative separation and purification of bufadienolides from ChanSu by high-speed counter-current chromatography combined with preparative HPLC

    Energy Technology Data Exchange (ETDEWEB)

    Li, Jialian; Zhang, Yongqing, E-mail: fleiv@163.com [College of Pharmacy, Shandong University of Traditional Chinese Medicine, Jinan, Shandong (China); Lin, Yunliang; Wang, Xiao; Fang, Lei; Geng, Yanling [Shandong Analysis and Test Center, Shandong Academy of Sciences, Jinan, Shandong (China); Zhang, Qinde [Shandong College of Traditional Chinese Medicine, Laiyang, Shandong (China)

    2013-09-01

    Eight bufadienolides were successfully isolated and purified from ChanSu by high-speed counter-current chromatography (HSCCC) combined with preparative HPLC (prep-HPLC). First, a stepwise elution mode of HSCCC with the solvent system composed of petroleum ether-ethyl acetate-methanol-water (4:6:4:6, 4:6:5:5, v/v) was employed and four bufadienolides, two partially purified fractions were obtained from 200 mg of crude extract. The partially purified fractions III and VI were then further separated by prepHPLC, respectively, and another four bufadienolides were recovered. Their structures were confirmed by ESI-MS and {sup 1}H-NMR spectra. (author)

  2. Comprehensive separation of secondary metabolites in natural products by high-speed counter-current chromatography using a three-phase solvent system.

    Science.gov (United States)

    Yanagida, Akio; Yamakawa, Yutaka; Noji, Ryoko; Oda, Ako; Shindo, Heisaburo; Ito, Yoichiro; Shibusawa, Yoichi

    2007-06-01

    High-speed counter-current chromatography (HSCCC) using the three-phase solvent system n-hexane-methyl acetate-acetonitrile-water at a volume ratio of 4:4:3:4 was applied to the comprehensive separation of secondary metabolites in several natural product extracts. A wide variety of secondary metabolites in each natural product was effectively extracted with the three-phase solvent system, and the filtered extract was directly submitted to the HSCCC separation using the same three-phase system. In the HSCCC profiles of crude natural drugs listed in the Japanese Pharmacopoeia, several physiologically active compounds were clearly separated from other components in the extracts. The HSCCC profiles of several tea products, each manufactured by a different process, clearly showed their compositional difference in main compounds such as catechins, caffeine, and pigments. These HSCCC profiles also provide useful information about hydrophobic diversity of whole components present in each natural product.

  3. Preparative Isolation and Purification of Four Compounds from Cistanches deserticola Y.C. Ma by High-Speed Counter-Current Chromatography

    Directory of Open Access Journals (Sweden)

    Lifeng Han

    2012-07-01

    Full Text Available Following a constituent enrichment step on a silica gel column, four phenyl-ethanoid glycosides were successfully isolated from Cistanches deserticola and purified by preparative high-speed counter-current chromatography (HSCCC with a two-phase solvent system composed of ethyl acetate-n-butanol-ethanol-water (40:6:6:50, v/v/v/v. A total of 30.9 mg acteoside, 13.0 mg isoacteoside, 12.5 mg syringalide A 3'-α-L-rhamnopyranoside and 7.2 mg 2'-acetylacteoside with purity of higher than 95%, as determined by HPLC-ELSD, were obtained in one-step separation from 297 mg of Cistanche deserticola extract, respectively. Their structures were identified by HR-MS, 1H-NMR and 13C-NMR.

  4. Preparative isolation and purification of harpagoside and angroside C from the root of Scrophularia ningpoensis Hemsley by high-speed counter-current chromatography.

    Science.gov (United States)

    Tian, Jinfeng; Ye, Xiaoli; Shang, Yuanhong; Deng, Yafei; He, Kai; Li, Xuegang

    2012-10-01

    In this study, the bioactive component harpagoside and angroside C in the root of Scrophularia ningpoensis Hemsley was simultaneously separated by high-speed counter-current chromatography (HSCCC). A two-phase solvent system containing chloroform/n-butanol/methanol/water (4:1:3:2, v/v/v/v) was selected following consideration of the partition coefficient of the target compound. The crude extract (200 mg) was loaded onto a 280-mL HSCCC column and yielded 22 mg harpagoside and 31 mg angroside C with the purity of higher than 98 and 98.5%, respectively. It is feasible to isolate active compounds harpagoside and angroside C from S. ningpoensis using HSCCC.

  5. Extraction and isolation of dictamnine, obacunone and fraxinellone from Dictamnus dasycarpus Turcz. by supercritical fluid extraction and high-speed counter-current chromatography

    Directory of Open Access Journals (Sweden)

    Daijie Wang

    2012-01-01

    Full Text Available Supercritical fluid extraction was used to extract active compounds from the Chinese traditional medicinal D. dasycarpus under the pressure of 30 MPa and temperature of 45 ºC. Further separation and purification was established by high-speed counter-current chromatography (HSCCC with a two-phase solvent system composed of n-hexane-ethyl acetate-methanol-water (1:0.8:1.3:0.9, volume ratio. The separation yielded a total of 47 mg of dictamnine, 24 mg of obacunone and 83 mg of fraxinellone from 1.0 g of the crude extract in one step separation with the purity of 99.2, 98.4 and 99.0%, respectively, as determined by HPLC. The chemical structures of these compounds were identified by ESI-MS, IR, ¹H-NMR and 13C-NMR.

  6. Application of preparative high-speed counter-current chromatography for isolation and separation of schizandrin and gomisin A from Schisandra chinensis.

    Science.gov (United States)

    Peng, Jinyong; Fan, Guorong; Qu, Liping; Zhou, Xin; Wu, Yutian

    2005-08-05

    Following an initial cleaning-up step on the D101 macroporous resin, a preparative high-speed counter-current chromatography (HSCCC) with a two-phase solvent system composed of n-hexane-ethyl acetate-methanol-water (1:0.9:0.9:1, v/v) was used to isolate and separate schizandrin and gomisin A from Schisandra chinensis. A total of 107 mg schizandrin and 36 mg gomisin A with purities of 99.5% and 99.1% were obtained from 400 mg crude extract in one-step elution and less than 3 h, and the structure identification was performed by UV, IR, MS, 1H NMR and 13C NMR.

  7. Preparative separation and purification of bufadienolides from ChanSu by high-speed counter-current chromatography combined with preparative HPLC

    Directory of Open Access Journals (Sweden)

    Jialian Li

    2013-01-01

    Full Text Available Eight bufadienolides were successfully isolated and purified from ChanSu by high-speed counter-current chromatography (HSCCC combined with preparative HPLC (prep-HPLC. First, a stepwise elution mode of HSCCC with the solvent system composed of petroleum ether - ethyl acetate - methanol - water (4:6:4:6, 4:6:5:5, v/v was employed and four bufadienolides, two partially purified fractions were obtained from 200 mg of crude extract. The partially purified fractions III and VI were then further separated by prep-HPLC, respectively, and another four bufadienolides were recovered. Their structures were confirmed by ESI-MS and ¹H-NMR spectra.

  8. Separation of five flavonoids from tartary buckwheat (Fagopyrum tataricum (L.) Gaertn) grains via off-line two dimensional high-speed counter-current chromatography.

    Science.gov (United States)

    Jiang, Shujing; Liu, Qi; Xie, Yixi; Zeng, Hualiang; Zhang, Li; Jiang, Xinyu; Chen, Xiaoqing

    2015-11-01

    An off-line two dimensional (2D) high-speed counter-current chromatography (HSCCC) strategy was successfully used for preparative separation of five flavonoids from tartary buckwheat (Fagopyrum tataricum (L.) Gaertn) grains with different solvent systems for the first time in this paper. n-Hexane-ethyl acetate-methanol-water 3:5:3:5 (v/v) was selected as the first dimension solvent system to purify quercetin (4) and kaempferol (5). The second dimension solvent system, ethyl acetate-n-butanol-water 7:3:10 (v/v), was used to isolate quercetin 3-O-rutinoside-3'-O-β-glucopyranoside (1), rutin (2) and kaempferol 3-rutinoside (3). The purities of these compounds were all above 96.0% and their structures were identified through UV, MS and (1)H NMR. The results indicated that the off-line 2D HSCCC is an efficient technique to isolate flavonoids compounds from grains.

  9. Extraction and isolation of dictamnine, obacunone and fraxinellone from Dictamnus dasycarpus Turcz. by supercritical fluid extraction and high-speed counter-current chromatography

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Daijie; Lin, Yunliang; Lin, Xiaojing; Geng, Yanling; Wang, Xiao, E-mail: wxjn1998@126.com [Process Control Research Center of TCM. Shandong Academy of Sciences. Shandong Analysis and Test Center (China); Zhang, Jinjie [College of Biosystems Engineering and Food Science, Zhejiang University (China); Qiu, Jiying [Institute of Agro-Food Science and Technology, Shandong Academy of Agricultural Science, Shandong (China)

    2012-07-01

    Supercritical fluid extraction was used to extract active compounds from the Chinese traditional medicinal D. dasycarpus under the pressure of 30 MPa and temperature of 45 degree C. Further separation and purification was established by high-speed counter-current chromatography (HSCCC) with a two-phase solvent system composed of n-hexane-ethyl acetate-methanol-water (1:0.8:1.3:0.9, volume ratio). The separation yielded a total of 47 mg of dictamnine, 24 mg of obacunone and 83 mg of fraxinellone from 1.0 g of the crude extract in one step separation with the purity of 99.2, 98.4 and 99.0%, respectively, as determined by HPLC. The chemical structures of these compounds were identified by ESI-MS, IR, 1H-NMR and {sup 13}C-NMR. (author)

  10. An improved design of spiral tube assembly for separation of proteins by high-speed counter-current chromatography.

    Science.gov (United States)

    Dasarathy, Dhweeja; Ito, Yoichiro

    2015-10-30

    A new spiral tube assembly was designed to improve the column capacity and partition efficiency for protein separation. This spiral tube assembly has greater column capacity than the original tubing because of an increase in radial grooves from 4 to 12 to accommodate more spiral layers and 12 narrow spots instead of 4 in each circular loop to interrupt the laminar flow that causes sample band broadening. Standard PTFE tubing (1.6mm ID) and the modified flat-twisted tubing were used as the separation column. The performances of both assemblies were compared for separating three stable test proteins including cytochrome c, myoglobin, and lysozyme using a two phase aqueous-aqueous solvent system composed of polyethylene glycol 1000 (12.5% w/w) and dibasic potassium phosphate (12.5% w/w). All samples were run at 1, 2, 3, and 5mL/min at both 800rpm and 1000rpm. The separation of these three protein samples produced high stationary phase retentions at 1, 2, and 3mL/min, yet separated efficiently at 5mL/min in 40min. After comparing the separation efficiency in terms of the peak resolutions, theoretical plate numbers, and separation times, it was determined that the flat-twisted tubing was more effective in separating these protein samples. In order to validate the efficacy of this novel assembly, a mixture of five protein samples (cytochrome c, myoglobin, ovalbumin, lysozyme, and hemoglobin) were separated, under the optimal conditions established with these three protein samples, at 1mL/min with a revolution speed of 1000rpm. There were high stationary phase retentions of around 60%, with effective separations, demonstrating the efficiency of the flat-twisted spiral tube assembly. The separation time of 6h was a limitation but can potentially be shortened by improving the strength of the column that will permit an increase in revolution speed and flow rate. This novel spiral separation column will allow rapid and efficient separation of mixtures with high yield of the

  11. Separation and identification of polyphenols in apple pomace by high-speed counter-current chromatography and high-performance liquid chromatography coupled with mass spectrometry.

    Science.gov (United States)

    Cao, Xueli; Wang, Cong; Pei, Hairun; Sun, Baoguo

    2009-05-01

    Apple pomace, a by-product in the processing of apple juice, was investigated as a potential source of polyphenols. Two methods of separation and purification of polyphenols from apple pomace extract were established by combination of gel chromatography with high-speed counter-current chromatography (HSCCC) and solvent extraction with HSCCC, respectively. The optimal separation was performed on a Sephadex LH-20 column using gradient aqueous ethanol as eluting solvent from 0% to 100% in increments of 10%. HPLC analysis indicated that main polyphenols existed in fractions eluted between 40% and 50% aqueous ethanol. The fractions of interest from column were separated by HSCCC with the solvent system hexane-ethyl acetate-1% aqueous acetic acid (0.5:9.5:10, v/v/v). Ethyl acetate fractionation of the apple pomace extract followed by direct HSCCC separation by the same solvent system in the volume ratio of 1:9:10 also produced a good separation of the main polyphenols of interest. Six high-purity polyphenols were achieved tentatively and identified by HPLC/MS: chlorogenic acid (1, m/z 354), quercetin-3-glucoside/quercetin-3-glacaside (2, m/z 464), quercetin-3-xyloside (3, m/z 434), phloridzin (4, m/z 436), quercetin-3-arabinoside (5, m/z 434), and quercetin-3-rhamnoside (6, m/z 448). These results provided a preliminary foundation for further development and exploration of apple pomace.

  12. Rapid preparative separation of six bioactive compounds from Gentiana crassicaulis Duthie ex Burk. using microwave-assisted extraction coupled with high-speed counter-current chromatography.

    Science.gov (United States)

    Liang, Jinru; Ito, Yoichiro; Zhang, Xinxin; He, Jiao; Sun, Wenji

    2013-12-01

    A rapid method combining microwave-assisted extraction (MAE) and high-speed counter-current chromatography (HSCCC) was applied for preparative separation of six bioactive compounds including loganic acid (I), isoorientin-4'-O-glucoside (II), 6'-O-β-d-glucopyranosyl gentiopicroside (III), swertiamarin (IV), gentiopicroside (V), sweroside (VI) from traditional Tibetan medicine Gentiana crassicaulis Duthie ex Burk. MAE parameters were predicted by central composite design response surface methodology. That is, 5.0 g dried roots of G. crassicaulis were extracted with 50 mL 57.5% aqueous ethanol under 630 W for 3.39 min. The extract (gentian total glycosides) was separated by HSCCC with n-butanol/ethyl acetate/methanol/1% acetic acid water (7.5:0.5:0.5:3.5, v/v/v/v) using upper phase mobile in tail-to-head elution mode. 16.3, 8.8, 12., 25.1, 40.7, and 21.8 mg of compounds I-VI were obtained with high purities in one run from 500 mg of original sample. The purities and identities of separated components were confirmed using HPLC with photo diode array detection and quadrupole TOF-MS and NMR spectroscopy. The study reveals that response surface methodology is convenient and highly predictive for optimizing extraction process, MAE coupled with HSCCC could be an expeditious method for extraction and separation of phytochemicals from ethnomedicine.

  13. Preparative isolation and purification of urolithins from the intestinal metabolites of pomegranate ellagitannins by high-speed counter-current chromatography.

    Science.gov (United States)

    Zhao, Wenhua; Wang, Yuji; Hao, Weijia; Yang, Hua; Song, Xueying; Zhao, Ming; Peng, Shiqi

    2015-05-15

    Urolithins were separated from the intestinal metabolites of pomegranate ellagitannins by high-speed counter current chromatography in two steps using two solvent systems composed of n-hexane-ethyl acetate-methanol-acetic acid-water (2.5:2:0.25:5, v/v/v/v/v) and n-hexane-ethyl acetate-methanol-acetic acid-water (2.5:0. 8:0.25:5, v/v/v/v/v) for the first time. Each injection of 100mg extract yielded 21mg of pure urolithin A and 10mg of pure urolithin B. High-performance liquid chromatography analyses revealed that the purity of urolithin A and urolihtin B was over 98.5%. The structures of urolithin A and urolitihn B were identified by high resolution-MS, NMR and single crystal x-ray analysis. Urolithins reduced the oxidative stress status in colon cancer by decreasing the intracellular ROS and malondialdehyde levels, and increasing SOD activity in H2O2 treated Caco-2 cells.

  14. Separation and Purification of Ombuoside from Gynostemma Pentaphyllum by Microwave-Assisted Extraction Coupled with High-Speed Counter-current Chromatography.

    Science.gov (United States)

    Jiang, Wenhui; Shan, Hu; Song, Jiying; Lü, Haitao

    2017-01-01

    A rapid and efficient method for the separation and purification of ombuoside from Gynostemma pentaphyllum by microwave-assisted extraction coupled with high-speed counter-current chromatography (HSCCC) was successfully developed. Using an orthogonal array design L9 (3(4)), the extraction conditions, including microwave power, irradiation time, solid-to-liquid ratio and extraction times, were optimized. Ombuoside was isolated and purified from the crude extraction by HSCCC with two-phase solvent system composed of n-hexane:ethyl acetate:ethanol:water (5:6:5:5, v/v) in a single run. A 210 mg quantity of the crude extract containing 2.16% ombuoside was loaded, yielding 3.9 mg of ombuoside at 96.7% purity. The chemical structure of ombuoside was determined by comparison with the high-performance liquid chromatography retention time of standard substance as well as UV, FT-IR, ESI-MS, (1)H NMR and (13)C NMR spectra. The purified ombuoside had strong 1,1-diphenyl-2-picrylhydrazyl and hydroxyl free radical scavenging activities. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  15. Preparative separation of sulfur-containing diketopiperazines from marine fungus Cladosporium sp. using high-speed counter-current chromatography in stepwise elution mode.

    Science.gov (United States)

    Gu, Binbin; Zhang, Yanying; Ding, Lijian; He, Shan; Wu, Bin; Dong, Junde; Zhu, Peng; Chen, Juanjuan; Zhang, Jinrong; Yan, Xiaojun

    2015-01-09

    High-speed counter-current chromatography (HSCCC) was successively applied to the separation of three sulfur-containing diketopiperazines (DKPs) (including two new compounds cladosporin A (1) and cladosporin B (3), and a known compound haematocin (2)) from a marine fungus Cladosporium sp. The two-phase solvent system composed of n-hexane-ethyl acetate-methanol-water at (1:1:1:1, v/v) and (2:1:2:1, v/v), in stepwise elution mode, was used for HSCCC. The preparative HSCCC separation was performed on 300 mg of crude sample yielding 26.7 mg of compound 3 at a purity of over 95%, 53.6 mg of a mixture of compounds 1 and 2, which was further separated by preparative-HPLC yielding 14.3 mg of compound 1 and 25.4 mg of compound 2 each at a purity of over 95%. Their structures were established by spectroscopic methods. The sulfur-containing DKPs suppressed the proliferation of hepatocellular carcinoma cell line HepG2. The present work represents the first application of HSCCC in the efficient preparation of marine fungal natural products.

  16. Preparative Isolation of Two Prenylated Biflavonoids from the Roots and Rhizomes of Sinopodophyllum emodi by Sephadex LH-20 Column and High-Speed Counter-Current Chromatography

    Directory of Open Access Journals (Sweden)

    Yan-Jun Sun

    2015-12-01

    Full Text Available Two prenylated biflavonoids, podoverines B–C, were isolated from the dried roots and rhizomes of Sinopodophyllum emodi using a Sephadex LH-20 column (SLHC and high-speed counter-current chromatography (HSCCC. The 95% ethanol extract was partitioned with ethyl acetate in water. Target compounds from the ethyl acetate fraction were further enriched and purified by the combined application of SLHC and HSCCC. n-Hexane–ethyl acetate–methanol–water (3.5:5:3.5:5, v/v was chosen as the two phase solvent system. The flow rate of mobile phase was optimized at 2.0 mL·min−1. Finally, under optimized conditions, 13.8 mg of podoverine B and 16.2 mg of podoverine C were obtained from 200 mg of the enriched sample. The purities of podoverines B and C were 98.62% and 99.05%, respectively, as determined by HPLC. For the first time, podoverins B and C were found in the genus Sinopodophyllum. Their structures were determined by spectroscopic methods (HR-ESI-MS, 1H-NMR, 13C-NMR, HSQC, HMBC. Their absolute configurations were elucidated by comparison of their experimental and calculated ECD spectra. The cytotoxic activities were evaluated against MCF-7 and HepG2 cell lines. The separation procedures proved to be practical and economical, especially for trace prenylated biflavonoids from traditional Chinese medicine.

  17. One-step separation of nine structural analogues from Poria cocos (Schw.) Wolf. via tandem high-speed counter-current chromatography.

    Science.gov (United States)

    Zeng, Hualiang; Liu, Qi; Yu, Jingang; Jiang, Xinyu; Wu, Zhiliang; Wang, Meiling; Chen, Miao; Chen, Xiaoqing

    2015-11-01

    A novel one-step separation strategy-tandem high-speed counter-current chromatography (HSCCC) was developed with a six-port valve serving as the switch interface. Nine structural analogues including three isomers were successfully isolated from Poria cocos (Schw.) Wolf. by one step. Compared with conventional HSCCC, peak resolution of target compounds was effectively improved in tandem one. Purities of isolated compounds were all over 90% as determined by HPLC. Their structures were then identified via UV, MS and (1)H NMR, and eventually assigned as poricoic acid B (1), poricoic acid A (2), 3β,16α-dihydroxylanosta-7, 9(11), 24-trien-21-oic acid (3), dehydrotumulosic acid (4), polyporenic acid C (5), 3-epi-dehydrotumulosic acid (6), 3-o-acetyl-16α-hydroxydehydrotrametenolic acid (7), dehydropachymic acid (8) and dehydrotrametenolic acid (9) respectively. The results indicated that tandem HSCCC can effectively improve peak resolution of target compounds, and can be a good candidate for HSCCC separation of structural analogues.

  18. Preparative Isolation of Two Prenylated Biflavonoids from the Roots and Rhizomes of Sinopodophyllum emodi by Sephadex LH-20 Column and High-Speed Counter-Current Chromatography.

    Science.gov (United States)

    Sun, Yan-Jun; Pei, Li-Xin; Wang, Kai-Bo; Sun, Yin-Shi; Wang, Jun-Min; Zhang, Yan-Li; Gao, Mei-Ling; Ji, Bao-Yu

    2015-12-23

    Two prenylated biflavonoids, podoverines B-C, were isolated from the dried roots and rhizomes of Sinopodophyllum emodi using a Sephadex LH-20 column (SLHC) and high-speed counter-current chromatography (HSCCC). The 95% ethanol extract was partitioned with ethyl acetate in water. Target compounds from the ethyl acetate fraction were further enriched and purified by the combined application of SLHC and HSCCC. n-Hexane-ethyl acetate-methanol-water (3.5:5:3.5:5, v/v) was chosen as the two phase solvent system. The flow rate of mobile phase was optimized at 2.0 mL·min(-1). Finally, under optimized conditions, 13.8 mg of podoverine B and 16.2 mg of podoverine C were obtained from 200 mg of the enriched sample. The purities of podoverines B and C were 98.62% and 99.05%, respectively, as determined by HPLC. For the first time, podoverins B and C were found in the genus Sinopodophyllum. Their structures were determined by spectroscopic methods (HR-ESI-MS, ¹H-NMR, (13)C-NMR, HSQC, HMBC). Their absolute configurations were elucidated by comparison of their experimental and calculated ECD spectra. The cytotoxic activities were evaluated against MCF-7 and HepG2 cell lines. The separation procedures proved to be practical and economical, especially for trace prenylated biflavonoids from traditional Chinese medicine.

  19. Isolation of C-glycosylflavonoids with α-glucosidase inhibitory activity from Passiflora bogotensis Benth by gradient high-speed counter-current chromatography.

    Science.gov (United States)

    Costa, Geison Modesti; Cárdenas, Paola Andrea; Gazola, Andressa Córneo; Aragón, Diana Marcela; Castellanos, Leonardo; Reginatto, Flávio Henrique; Ramos, Freddy Alejandro; Schenkel, Eloir Paulo

    2015-05-15

    In this study, we applied a gradient High-Speed Counter-Current Chromatography (HSCCC) method that allowed, by direct injection of an aqueous crude extract of the leaves of Passiflora bogotensis, the successful isolation of six flavonoids in a single run, with purity of each compound higher than 81%. This separation enabled the isolation of two new flavonoid glycosides, apigenin-6-C-α-l-rhamnopyranosyl-(1→2)-(6″-O-acetyl)-β-d-glucopyranoside (2) and luteolin-6-C-α-l-rhamnopyranosyl-(1→2)-(6″-O-acetyl)-β-d-glucopyranoside (4), and four known ones, isovitexin (1), isoorientin (3), isovitexin-2″-O-rhamnoside (5) and isoorientin-2″-O-rhamnoside (6). The structures of the isolated compounds were identified by HPLC-DAD, LC-MS, (1)H and (13)C NMR and comparison with literature data. The inhibitory activities of all of these compounds were evaluated in vitro on α-glucosidase from S. cerevisiae, and the IC50 was determinate. This is the first study concerning the chemical composition and biological activity of Passiflora bogotensis.

  20. Bioassay-guided preparative separation of angiotensin-converting enzyme inhibitory C-flavone glycosides from Desmodium styracifolium by recycling complexation high-speed counter-current chromatography.

    Science.gov (United States)

    Zhang, Ying-Qi; Luo, Jian-Guang; Han, Chao; Xu, Jin-Fang; Kong, Ling-Yi

    2015-01-01

    A new strategy of the convergence of high-speed counter-current chromatography (HSCCC) and bioactive assay technique was developed for rapidly screening and separating the angiotensin-converting enzyme (ACE) inhibitors from the aerial parts of Desmodium styracifolium. Bioactivity-guided fractionation of the crude extract was first established to target the bioactive fractions based on HSCCC coupled with in vitro ACE inhibitory assay. Subsequently, the bioactive fractions were further separated by the recycling complexation HSCCC respectively, using 0.10 mol/L copper sulfate in the lower phase of two-phase solvent system composed of n-butanol/water (1:1, v/v). Five C-glycosylflavones, vicenin 2 (1), carlinoside (2), vicenin 1 (3), schaftoside (4) and vicenin 3 (5), were successfully obtained. Their chemical structures were identified using ESI-MS and NMR. All the isolates showed in vitro ACE inhibitory activity with the IC50 values between 33.62 and 58.37 μM. The results demonstrated that the established method was proposed as an excellent strategy to systematically screen and purify active compounds from traditional Chinese medicines.

  1. Offline coupling of high-speed counter-current chromatography and gas chromatography/mass spectrometry generates a two-dimensional plot of toxaphene components.

    Science.gov (United States)

    Kapp, Thomas; Vetter, Walter

    2009-11-20

    High-speed counter-current chromatography (HSCCC), a separation technique based solely on the partitioning of solutes between two immiscible liquid phases, was applied for the fractionation of technical toxaphene, an organochlorine pesticide which consists of a complex mixture of structurally closely related compounds. A solvent system (n-hexane/methanol/water 34:24:1, v/v/v) was developed which allowed to separate compounds of technical toxaphene (CTTs) with excellent retention of the stationary phase (S(f) = 88%). Subsequent analysis of all HSCCC fractions by gas chromatography coupled to electron-capture negative ion mass spectrometry (GC/ECNI-MS) provided a wealth of information regarding separation characteristics of HSCCC and the composition of technical toxaphene. The visualization of the large amount of data obtained from the offline two-dimensional HSCCC-GC/ECNI-MS experiment was facilitated by the creation of a two-dimensional (2D) contour plot. The contour plot not only provided an excellent overview of the HSCCC separation progress, it also illustrated the differences in selectivity between HSCCC and GC. The results of this proof-of-concept study showed that the 2D chromatographic approach involving HSCCC facilitated the separation of CTTs that coelute in unidimensional GC. Furthermore, the creation of 2D contour plots may provide a useful means of enhancing data visualization for other offline two-dimensional separations.

  2. Separation of polyphenols from leaves of Malus hupehensis (Pamp.) Rehder by off-line two-dimensional High Speed Counter-Current Chromatography combined with recycling elution mode.

    Science.gov (United States)

    Liu, Qi; Zeng, Hualiang; Jiang, Shujing; Zhang, Li; Yang, Fuzhu; Chen, Xiaoqing; Yang, Hua

    2015-11-01

    In this study, off-line two-dimensional High Speed Counter-Current Chromatography (2D HSCCC) strategy combined with recycling elution mode was developed to isolate compounds from the ethyl acetate extract of a common green tea--leaves of Malus hupehensis (Pamp.) Rehder. In the orthogonal separation system, a conventional HSCCC was employed for the first dimension and two recycling HSCCCs were used for the second in parallel. Using a solvent system consisting of n-hexane-ethyl acetate-methanol-water (1:4:0.6:4.4, v/v) in the first and second dimension, four compounds including 3-hydroxy-phlorizin (1), phloretin (2), avicularin (3) and kaempferol 3-O-β-D-glucoside (4) were obtained. The purities of these four compounds were all over 95.0% as determined by HPLC. And their structures were all identified through UV, MS and (1)H NMR. It has been demonstrated that the combination of off-line 2D HSCCC with recycling elution mode is an efficient technique to isolate compounds with similar polarities in natural products.

  3. Application of high-speed counter-current chromatography for isolation of triterpenes from Schisandra Chinensis (Turcz.) Baill and induction apoptosis mechanism of HSC-T6.

    Science.gov (United States)

    Li, Bin; Meng, Xianjun; Zhu, Lijie; Jiao, Xinyao; Zhang, Jiachen

    2014-01-01

    Triterpenes have shown many beneficial activities in researches, but their separation and preparation usually require multiple methods. Following an initial cleaning-up step on the AB-8 macroporous resin, a preparative high-speed counter-current chromatography (HSCCC) with a two-phase solvent system comprising chloroform-n-butyl alcohol-methanol-water (10:1:7:4, v/v/v/v) was used to isolate and separate triterpenes from caculis of Schisandra Chinensis (Turcz.) baill. A total of 89 mg corosolic acid with purities of 98.5% were obtained from 400 mg crude extract in one-step elution and less than 4 h, and the structure identification was performed by UV, IR, MS, 1H NMR and 13C NMR. The inhibition on liver fibrosis activities of the triterpenes against HSC-T6 in vitro were studied by cell culture methods. The results showed that the corosolic acid have better inhibitory effects on HSC-T6 cells with the IC50 value of 5~25 μg/mL and the study also indicated that corosolic acid might be a potential Chinese medical component to inhibit liver fibrosis.

  4. Preparative isolation and purification of lignans from Justicia procumbens using high-speed counter-current chromatography in stepwise elution mode.

    Science.gov (United States)

    Zhou, Peijuan; Luo, Qijun; Ding, Lijian; Fang, Fang; Yuan, Ye; Chen, Juanjuan; Zhang, Jinrong; Jin, Haixiao; He, Shan

    2015-04-20

    Lignans, which are recognized as main constituents in Justicia procumbens, have attracted considerable attention due to their pharmacological activities, including antitumor, anti-hepatitic, cytotoxic, anti-microbial, and anti-virus properties. Preparative high-speed counter-current chromatography (HSCCC) was successfully applied to the isolation and purification of four lignans (justicidin B (1), justicidin A (2), 6'-hydroxyjusticidin C (3) and lignan J1 (4)) from J. procumbens using stepwise elution with a pair of two-phase solvent systems composed of n-hexane-ethyl acetate-methanol-water at (1.3:1:1.3:1, v/v) and (2.5:1:2.5:1, v/v). The preparative HSCCC separation was performed on 300 mg of crude sample yielding compounds 1 (19.7 mg), 2 (9.86 mg), 3 (11.26 mg), and 4 (2.54 mg) in a one-step separation, with purities over 95% as determined by HPLC. The structures of these compounds were identified by MS, 1H-NMR and 13C-NMR. This is the first report on the application of HSCCC to the efficient separation of lignans from J. procumbens.

  5. Preparative Separation of Sulfur-Containing Diketopiperazines from Marine Fungus Cladosporium sp. Using High-Speed Counter-Current Chromatography in Stepwise Elution Mode

    Directory of Open Access Journals (Sweden)

    Binbin Gu

    2015-01-01

    Full Text Available High-speed counter-current chromatography (HSCCC was successively applied to the separation of three sulfur-containing diketopiperazines (DKPs (including two new compounds cladosporin A (1 and cladosporin B (3, and a known compound haematocin (2 from a marine fungus Cladosporium sp. The two-phase solvent system composed of n-hexane-ethyl acetate-methanol-water at (1:1:1:1, v/v and (2:1:2:1, v/v, in stepwise elution mode, was used for HSCCC. The preparative HSCCC separation was performed on 300 mg of crude sample yielding 26.7 mg of compound 3 at a purity of over 95%, 53.6 mg of a mixture of compounds 1 and 2, which was further separated by preparative-HPLC yielding 14.3 mg of compound 1 and 25.4 mg of compound 2 each at a purity of over 95%. Their structures were established by spectroscopic methods. The sulfur-containing DKPs suppressed the proliferation of hepatocellular carcinoma cell line HepG2. The present work represents the first application of HSCCC in the efficient preparation of marine fungal natural products.

  6. Separation and purification of neohesperidin from the albedo of Citrus reticulata cv. Suavissima by combination of macroporous resin and high-speed counter-current chromatography.

    Science.gov (United States)

    Zhang, Jiukai; Zhu, Xiaoyan; Luo, Fenglei; Sun, Chongde; Huang, Jianzhen; Li, Xian; Chen, Kunsong

    2012-01-01

    In this article, a simple and efficient protocol for rapid preparation and separation of neohesperidin from the albedo of Citrus reticulata cv. Suavissima was established by the combination of macroporous resin column chromatography and high-speed counter-current chromatography (HSCCC). Six types of resin were investigated by adsorption and desorption tests, and D101 macroporous resin was selected for the first cleaning-up procedure, in which 55% aqueous ethanol was used to elute neohesperidin. After treatment with D101 resin, the neohesperidin purity increased 11.83-fold from 4.92% in the crude extract to 58.22% in the resin-refined sample, with a recovery of 68.97%. The resin-refined sample was directly subjected to HSCCC purification with a two-phase solvent system composed of ethyl acetate-n-butanol-water (4:1:5, v/v), and 23.6 mg neohesperidin with 97.47% purity was obtained from 60 mg sample in only one run. The recovery of neohesperidin in HSCCC separation procedure was 65.85%. The chemical structure of the purified neohesperidin was identified by both HPLC and LC-MS. The established purification process will be helpful for further characterization and utilization of Citrus neohesperidin.

  7. Efficient Preparation of Streptochlorin from Marine Streptomyces sp. SYYLWHS-1-4 by Combination of Response Surface Methodology and High-Speed Counter-Current Chromatography

    Directory of Open Access Journals (Sweden)

    Lin Li

    2016-05-01

    Full Text Available Since first isolated from the lipophilic extract of Streptomyces sp. SF2583, streptochlorin, has attracted a lot of attention because of its various pharmacological properties, such as antibiotic, antiallergic, antitumor, and anti-inflammatory activities. For the efficient preparation of streptochlorin from a producing strain Streptomyces sp. SYYLWHS-1-4, we developed a combinative method by using response surface methodology (RSM and high-speed counter-current chromatography (HSCCC. In the fermentation process, we used RSM to optimize the condition for the efficient accumulation of streptochlorin, and the optimal parameters were: yeast extract 1.889 g/L, soluble starch 8.636 g/L, K2HPO4 0.359 g/L, CaCl2 2.5 g/L, MgSO4 0.625 g/L, marine salt 25 g/L, medium volume 50%, initial pH value 7.0, temperature 27.5 °C, which enhanced streptochlorin yield by 17.7-fold. During the purification process, the preparative HSCCC separation was performed using a petroleum ether–ethyl acetate–methanol–water (9:0.8:5:5, v/v/v/v biphasic solvent system, where 300 mg of crude sample yielded 16.5 mg streptochlorin with over 95% purity as determined by UPLC. Consequently, the combination method provided a feasible strategy for highly effective preparation of streptochlorin, which ensured the supply of large amounts of streptochlorin for in vivo pharmacological assessments or other requirements.

  8. Isolation and purification of lignans from Schisandra chinensis by combination of silica gel column and high-speed counter-current chromatography

    Directory of Open Access Journals (Sweden)

    Sun Yu

    2013-01-01

    Full Text Available Silica gel column combined with high-speed counter-current chromatography separation was successfully applied to the separation of schizandrin (I, angeloylgomisin H (II, gomisin A (III, schisantherin C (IV, deoxyschizandrin (V, γ-schisandrin (VI and schisandrin C (VII from the fruits of Schisandra chinensis (Turcz. Baillon. The petroleum ether extracts of the fruits of S. chinensis were pre-separated first on a silica gel column and divided into two fractions as sample 1 and sample 2. 260 mg of sample 1 was separated by HSCCC using petroleum ether-ethyl acetate-methanol-water (10:8:10:8, v/v as the two-phase solvent system and 18.2 mg of schizandrin, 15.7 mg of angeloylgomisin H, 16.5 mg of gomisin A and 16.7 mg of schisantherin C were obtained. 230 mg of sample 2 was separated using petroleum ether-ethyl acetate-methanol-water (10:0.5:10:1, v/v as the two-phase solvent system and 19.7 mg of deoxyschizandrin, 23.4 mg of γ-schisandrin and 18.2 mg of schisandrin C were obtained. The purities of the separated compounds were all over 94% as determined by HPLC. The chemical structures of these compounds were confirmed by ESI-MS and 1H NMR. [Acknowledgments. Natural Science Foundation of China (20872083, scientific and technological major special project (2010ZX09401-302-5-12 and the Key Science and Technology Program of Shandong Province (BS2009SW047

  9. Performance comparison of three types of high-speed counter-current chromatographs for the separation of components of hydrophilic and hydrophobic color additives.

    Science.gov (United States)

    Weisz, Adrian; Ito, Yoichiro

    2011-09-09

    The performance of three types of high-speed counter-current chromatography (HSCCC) instruments was assessed for their use in separating components in hydrophilic and hydrophobic dye mixtures. The HSCCC instruments compared were: (i) a J-type coil planet centrifuge (CPC) system with a conventional multilayer-coil column, (ii) a J-type CPC system with a spiral-tube assembly-coil column, and (iii) a cross-axis CPC system with a multilayer-coil column. The hydrophilic dye mixture consisted of a sample of FD&C Blue No. 2 that contained mainly two isomeric components, 5,5'- and 5,7'-disulfonated indigo, in the ratio of ∼7:1. The hydrophobic dye mixture consisted of a sample of D&C Red No. 17 (mainly Sudan III) and Sudan II in the ratio of ∼4:1. The two-phase solvent systems used for these separations were 1-butanol/1.3M HCl and hexane/acetonitrile. Each of the three instruments was used in two experiments for the hydrophilic dye mixture and two for the hydrophobic dye mixture, for a total of 12 experiments. In one set of experiments, the lower phase was used as the mobile phase, and in the second set of experiments, the upper phase was used as the mobile phase. The results suggest that: (a) use of a J-type instrument with either a multilayer-coil column or a spiral-tube assembly column, applying the lower phase as the mobile phase, is preferable for separating the hydrophilic components of FD&C Blue No. 2; and (b) use of a J-type instrument with multilayer-coil column, while applying either the upper phase or the lower phase as the mobile phase, is preferable for separating the hydrophobic dye mixture of D&C Red No. 17 and Sudan II.

  10. Preparative separation of two subsidiary colors of FD&C Yellow No. 5 (Tartrazine) using spiral high-speed counter-current chromatography◊

    Science.gov (United States)

    Roque, Jose A.; Mazzola, Eugene P.; Ito, Yoichiro

    2014-01-01

    Specifications in the U.S. Code of Federal Regulations for the color additive FD&C Yellow No. 5 (Colour Index No. 19140) limit the level of the tetrasodium salt of 4-[(4',5-disulfo[1,1'-biphenyl]-2-yl)hydrazono]-4,5-dihydro-5-oxo-1-(4-sulfophenyl)-1H-pyrazole-3-carboxylic acid and that of the trisodium salt of 4,4'-[4,5-dihydro-5-oxo-4-[(4-sulfophenyl)hydrazono]-1H-pyrazol-1,3-diyl]bis[benzenesulfonic acid], which are subsidiary colors abbreviated as Pk5 and Pk7, respectively. Small amounts of Pk5 and Pk7 are needed by the U.S. Food and Drug Administration for confirmatory analyses and for development of analytical methods. The present study describes the use of spiral high-speed counter-current chromatography (HSCCC) with the recently introduced highly polar organic/high-ionic strength aqueous solvent systems to separate Pk5 and Pk7 from a sample of FD&C Yellow No. 5 containing ~3.5% Pk5 and ~0.7% Pk7. Multiple ~1.0 g portions of FD&C Yellow No. 5 (totaling 6.4 g dye) were separated, using the upper phase of the solvent system 1-BuOH/EtOHabs/saturated ammonium sulfate/water, 1.7:0.3:1:1, v/v/v/v, as the mobile phase. After applying a specially developed method for removing the ammonium sulfate from the HSCCC-collected fractions, these separations resulted in an enriched mixture (~160 mg) of Pk5 and Pk7 (~46% and ~21%, respectively). Separation of the enriched mixture, this time using the lower phase of that solvent system as the mobile phase, resulted in ~ 61 mg of Pk5 collected in fractions whose purity ranged from 88.0% to 92.7% (by HPLC at 254 nm). Pk7 (20.7 mg, ~83% purity) was recovered from the upper phase of the column content. Application of this procedure also resulted in purifying the major component of FD&C Yellow No. 5 to >99% purity. The separated compounds were characterized by high-resolution mass spectrometry and several 1H and 13C nuclear magnetic resonance spectroscopic techniques (COSY, NOESY, HSQC, and HMBC). PMID:24755184

  11. Preparative separation of two subsidiary colors of FD&C Yellow No. 5 (Tartrazine) using spiral high-speed counter-current chromatography.

    Science.gov (United States)

    Weisz, Adrian; Ridge, Clark D; Roque, Jose A; Mazzola, Eugene P; Ito, Yoichiro

    2014-05-23

    Specifications in the U.S. Code of Federal Regulations for the color additive FD&C Yellow No. 5 (Color Index No. 19140) limit the level of the tetrasodium salt of 4-[(4',5-disulfo[1,1'-biphenyl]-2-yl)hydrazono]-4,5-dihydro-5-oxo-1-(4-sulfophenyl)-1H-pyrazole-3-carboxylic acid and that of the trisodium salt of 4,4'-[4,5-dihydro-5-oxo-4-[(4-sulfophenyl)hydrazono]-1H-pyrazol-1,3-diyl]bis[benzenesulfonic acid], which are subsidiary colors abbreviated as Pk5 and Pk7, respectively. Small amounts of Pk5 and Pk7 are needed by the U.S. Food and Drug Administration for confirmatory analyses and for development of analytical methods. The present study describes the use of spiral high-speed counter-current chromatography (HSCCC) to separate the closely related minor components Pk5 and Pk7 from a sample of FD&C Yellow No. 5 containing ∼3.5% Pk5 and ∼0.7% Pk7. The separations were performed with highly polar organic/high-ionic strength aqueous two-phase solvent systems that were chosen by applying the recently introduced method known as graphic optimization of partition coefficients (Zeng et al., 2013). Multiple ∼1.0g portions of FD&C Yellow No. 5 (totaling 6.4g dye) were separated, using the upper phase of the solvent system 1-butanol/abs. ethanol/saturated ammonium sulfate/water, 1.7:0.3:1:1, v/v/v/v, as the mobile phase. After removing the ammonium sulfate from the HSCCC-collected fractions, these separations resulted in an enriched dye mixture (∼160mg) of which Pk5 represented ∼46% and Pk7, ∼21%. Separation of the enriched mixture, this time using the lower phase of that solvent system as the mobile phase, resulted in ∼61mg of Pk5 collected in fractions whose purity ranged from 88.0% to 92.7%. Pk7 (20.7mg, ∼83% purity) was recovered from the upper phase of the column contents. Application of this procedure also resulted in purifying the major component of FD&C Yellow No. 5 to >99% purity. The separated compounds were characterized by high-resolution mass

  12. The separation of flavonoids from Pongamia pinnata using combination columns in high-speed counter-current chromatography with a three-phase solvent system.

    Science.gov (United States)

    Yin, Hao; Zhang, Si; Long, Lijuan; Yin, Hang; Tian, Xinpeng; Luo, Xiongming; Nan, Haihan; He, Sha

    2013-11-01

    The mangrove plant Pongamia pinnata (Leguminosae) is well known as a plant pesticide. Previous studies have indicated that the flavonoids are responsible of the biological activities of the plant. A new high-speed counter-current chromatography (HSCCC) method for the separation of three flavonoids, karanjin (1), pinnatin (2), and pongaflavone (3), from P. pinnata was developed in the present study. The lower and intermediate phase (LP and IP) of a new three-phase solvent system, n-hexane-acetonitrile-dichloromethane-water, at a volume ratio of 5:5:1:5, were used as the stationary phases, while the upper phase (UP) was used as the mobile phase, and the volume ratio between the stationary phases in the CCC column could be tuned by varying the initial pumped volume ratio of the stationary phases. The CCC columns containing all three phases of the solvent system were considered combination columns. According to the theories of combination column, it is possible to optimize the retention time of the target compounds by varying the volume ratio of the stationary phases in the HSCCC combination columns, as well as the suitable volume ratios of the stationary phases for the separation of the target compounds were predicted from the partition coefficients of the compounds in the three-phase solvent system. Then, three HSCCC separations using the combination columns with initial pumped LP:IP volume ratios of 1:0, 0.9:0.1, and 0.7:0.3 were performed separately based on the prediction. Three target compounds were prepared with high purity when the initial pumped volume ratio of the stationary phases was 0.9:0.1. The baseline separation of compounds 2 and 3 was achieved on the combination column with an initial pumped volume ratio of 0.7:0.3. Furthermore, the three experiments clearly demonstrated that the retentions and resolutions of the target compounds increased with an increasing volume ratio of IP, which is consistent with the prediction for the retention times for the

  13. Investigation of unsaponifiable matter of plant oils and isolation of eight phytosterols by means of high-speed counter-current chromatography.

    Science.gov (United States)

    Schröder, Markus; Vetter, Walter

    2012-05-11

    Phytosterols are minor components of plant oils. Due to their beneficial effect on human serum cholesterol level, new products supplemented with phytosterols have been marketed. Commercial phytosterol standards are frequently of insufficient purity, very expensive, only available in (semi-) synthetic form or not available at all. For this reason we aimed to explore the unsaponifiable matter of three plant oils (rapeseed oil, linseed oil and olive oil) in order to study their compositions and to purify several phytosterols. We fractionated ∼ 100 mg of the unsaponifiable matter of the plant oils with high-speed counter-current chromatography (HSCCC) by the combination of an enrichment step and a purification step. In the first part (enrichment step) composition of phytosterols, alkanes, fatty alcohols from 14:0 to 30:0 including isomers, 15-nonacosanone and other ketones as well as further minor compounds in the different fractions was studied by GC/MS. By means of the solvent system n-hexane/methanol/aqueous silver nitrate solution (34/24/1, v/v/v) in normal phase mode (tail-to-head) β-sitosterol could be isolated (6.4 mg, purity ≥ 99%) and several phytosterols (e.g. citrostadienol, cycloeucalenol and erythrodiol) could be enriched. Moreover, the fast eluting hydrocarbons squalene and nonacosane as well as the later eluting phytol (pure, 7 mg) and geranyl geraniol could also be efficiently enriched. Suited HSCCC fractions from the three plant oils were merged and re-injected into the HSCCC system (purification step). The HSCCC purification step provided 6.9 mg campesterol (≥ 99%), 2.9 mg brassicasterol (≥ 99%), 0.3mg Δ5-avenasterol (≥ 90%), 9.5mg cycloartenol (≥ 90%), 3.7 mg 24-methylene-cycloartanol (≥ 99%), and ∼ 1mg of an unknown compound (∼ 80%) isolated from rapeseed and linseed oil. Furthermore, the combined HSCCC enrichment and purification of a hydrogenated sterol standard provided two pure phytostanols (campestanol ≥ 99% and sitostanol

  14. Preparative Separation of Phenolic Compounds from Chimonanthus praecox Flowers by High-Speed Counter-Current Chromatography Using a Stepwise Elution Mode

    Directory of Open Access Journals (Sweden)

    Huaizhi Li

    2016-08-01

    Full Text Available High-speed counter-current chromatography (HSCCC has been successfully used for the separation of eight compounds from Chimonanthus praecox flowers. Firstly, the crude extract of Chimonanthus praecox flowers was dissolved in a two-phase solvent system composed of petroleum ether–ethyl acetate–methanol–H2O (5:5:3:7, v/v and divided into two parts: the upper phase (part I and the lower phase (part II. Then, HSCCC was applied to separate the phenolic acids from part I and part II, respectively. Considering the broad polarity range of target compounds in part I, a stepwise elution mode was established. Two optimal solvent systems of petroleum ether–ethyl acetate–methanol–H2O–formic acid (FA (5:5:3:7:0.02, 5:5:4.3:5.7:0.02, v/v were employed in this separation. Five phenylpropanoids and two flavonoids were successfully separated from 280 mg of part I, including 8.7 mg of 3,4-dihydroxy benzoic acid (a, 95.3% purity, 10.9 mg of protocatechualdehyde (b, 96.8% purity, 11.3 mg of p-coumaric acid (c, 98.9% purity, 12.2 mg of p-hydroxybenzaldehyde (d, 95.9% purity, 24.7 mg of quercetin (e, 97.3% purity, 33.8 mg of kaempferol (f, 96.8% purity, and 24.6 mg of 4-hydroxylcinnamic aldehyde (g, 98.0% purity. From 300 mg of part II, 65.7 mg of rutin (h, 98.2% purity, 7.5 mg of 3,4-dihydroxy benzoic acid (a, 77.4% purity, and 4.7 mg of protocatechualdehyde (b, 81.6% purity were obtained using the solvent system EtOAc–n-butanol (n-BuOH–FA–H2O (4:1:0.5:5, v/v. The structures of the eight pure compounds were confirmed by electrospray ionization-mass spectrometry (ESI-MS, 1H-NMR and 13C-NMR. To the best of our knowledge, compounds a–d and f were the first separated and reported from the Chimonanthus praecox flower extract.

  15. Separation of five compounds from leaves of Andrographis paniculata (Burm. f.) Nees by off-line two-dimensional high-speed counter-current chromatography combined with gradient and recycling elution.

    Science.gov (United States)

    Zhang, Li; Liu, Qi; Yu, Jingang; Zeng, Hualiang; Jiang, Shujing; Chen, Xiaoqing

    2015-05-01

    An off-line two-dimensional high-speed counter-current chromatography method combined with gradient and recycling elution mode was established to isolate terpenoids and flavones from the leaves of Andrographis paniculata (Burm. f.) Nees. By using the solvent systems composed of n-hexane/ethyl acetate/methanol/water with different volume ratios, five compounds including roseooside, 5,4'-dihydroxyflavonoid-7-O-β-d-pyranglucuronatebutylester, 7,8-dimethoxy-2'-hydroxy-5-O-β-d-glucopyranosyloxyflavon, 14-deoxyandrographiside, and andrographolide were successfully isolated. Purities of these isolated compounds were all over 95% as determined by high-performance liquid chromatography. Their structures were identified by UV, mass spectrometry, and (1) H NMR spectroscopy. It has been demonstrated that the combination of off-line two-dimensional high-speed counter-current chromatography with different elution modes is an efficient technique to isolate compounds from complex natural product extracts.

  16. Application of an efficient strategy based on liquid-liquid extraction, high-speed counter-current chromatography, and preparative HPLC for the rapid enrichment, separation, and purification of four anthraquinones from Rheum tanguticum.

    Science.gov (United States)

    Chen, Tao; Liu, Yongling; Zou, Denglang; Chen, Chen; You, Jinmao; Zhou, Guoying; Sun, Jing; Li, Yulin

    2014-01-01

    This study presents an efficient strategy based on liquid-liquid extraction, high-speed counter-current chromatography, and preparative HPLC for the rapid enrichment, separation, and purification of four anthraquinones from Rheum tanguticum. A new solvent system composed of petroleum ether/ethyl acetate/water (4:2:1, v/v/v) was developed for the liquid-liquid extraction of the crude extract from R. tanguticum. As a result, emodin, aloe-emodin, physcion, and chrysophanol were greatly enriched in the organic layer. In addition, an efficient method was successfully established to separate and purify the above anthraquinones by high-speed counter-current chromatography and preparative HPLC. This study supplies a new alternative method for the rapid enrichment, separation, and purification of emodin, aloe-emodin, physcione, and chrysophanol. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  17. Fishing and knockout of bioactive compounds using a combination of high-speed counter-current chromatography (HSCCC) and preparative HPLC for evaluating the holistic efficacy and interaction of the components of Herba Epimedii.

    Science.gov (United States)

    Jin, Jing; Li, Yubo; Kipletting Tanui, Emmanuel; Han, Liwen; Jia, Yuan; Zhang, Lu; Wang, Yuming; Zhang, Xiuxiu; Zhang, Yanjun

    2013-05-20

    Due to the complex chemical compositions and pharmacological effects of traditional Chinese medicines, we developed a strategy based on fishing and knockout of bioactive compounds using a combination of high-speed counter-current chromatography (HSCCC) and preparative HPLC for evaluating the holistic activity and interaction of the components of Herba Epimedii. First, osteoblast target cell extraction was used for preliminary screening of the potential bioactive compounds of Herba Epimedii. Second, the bioactive compounds identified (epimedin A, epimedin B, epimedin C and icariin) were fished and knocked out using high-speed counter-current chromatography and preparative HPLC. Third, the bioactivity of resulting fractions was assessed by determining their influence on cell proliferation and differentiation, thereby allowing for an evaluation of their interaction.The pharmacodynamic contribution ratio of each bioactive compound to the efficacy of the herbal medicine could then be comprehensively and intuitively determined based on the spectra-activity correlations (VIP values) of the tested compositions using partial least-squares regression (PLS-R), through which the reliability of the screening and isolation of bioactive compounds by the target cell extraction technique were verified. The proposed strategy is a useful approach with potential application in other traditional Chinese medicines.

  18. Partition efficiencies of newly fabricated universal high-speed counter-current chromatograph for separation of two different types of sugar derivatives with organic-aqueous two-phase solvent systems.

    Science.gov (United States)

    Shinomiya, Kazufusa; Sato, Kazuki; Yoshida, Kazunori; Tokura, Koji; Maruyama, Hiroshi; Yanagidaira, Kazuhiro; Ito, Yoichiro

    2013-12-27

    A new design of universal high-speed counter-current chromatograph (HSCCC) was fabricated in our laboratory. It holds a set of four column holders symmetrically around the rotary frame at a distance of 11.2cm from the central axis. By engaging the stationary gear on the central axis of the centrifuge to the planetary gears on the column holder shaft through a set of idle gears, two pairs of diagonally located column holders simultaneously rotate about their own axes in the opposite directions: one forward (type-J planetary motion) and the other backward (type-I planetary motion) each synchronously with the revolution. Using the eccentric coil assembly, partition efficiencies produced by these two planetary motions were compared on the separation of two different types of sugar derivatives (4-methylumbelliferyl and 5-bromo-4-chloro-3-indoxyl sugar derivatives) using organic-aqueous two-phase solvent systems composed of n-hexane/ethyl acetate/1-butanol/methanol/water and aqueous 0.1M sodium tetraborate, respectively. With lower phase mobile, better peak resolution was obtained by the type-J forward rotation for both samples probably due to higher retention of the stationary phase. With upper phase mobile, however, similar peak resolutions were obtained between these two planetary motions for both sugar derivatives. The overall results indicate that the present universal HSCCC is useful for counter-current chromatographic separation since each planetary motion has its specific applications: e.g., vortex CCC by the type-I planetary motion and HSCCC by the type-J planetary motion both for separation of various natural and synthetic products.

  19. Preparative isolation of cordycepin, N(6)-(2-hydroxyethyl)-adenosine and adenosine from Cordyceps militaris by macroporous resin and purification by recycling high-speed counter-current chromatography.

    Science.gov (United States)

    Zhang, Zhong; Tudi, Tuernisan; Liu, Yanfang; Zhou, Shuai; Feng, Na; Yang, Yan; Tang, Chuanhong; Tang, Qingjiu; Zhang, Jingsong

    2016-10-15

    In this study, cordycepin, N(6)-(2-hydroxyethyl)-adenosine (HEA) and adenosine from the fruiting bodies of Cordyceps militaris were separated by using macroporous resin NKA-II adsorption. The parameters of static adsorption were tested and the optimized conditions were as follow: the total adsorption time was 12h, 50% ethanol was used for desorption and the desorption time was 9h. The crude sample that was prepared by macroporous resin NKA-II contained 3.4% cordycepin, 3.7% HEA and 4.9% adenosine. Then the crude sample was further purified by recycling high-speed counter-current chromatography (HSCCC) with ethyl acetate, n-butanol, 1.5% aqueous ammonium hydroxide (1:4:5, v/v/v) as the optimized two-phase solvent system. Three nucleosides including 15.6mg of cordycepin, 16.9mg of HEA and 23.2mg of adenosine were obtained from 500mg of crude sample in one-step separation. The purities of three compounds were 98.5, 98.3 and 98.0%, respectively, as determined by high performance liquid chromatography. Copyright © 2016. Published by Elsevier B.V.

  20. An Efficient Method for the Preparative Isolation and Purification of Flavonoid Glycosides and Caffeoylquinic Acid Derivatives from Leaves of Lonicera japonica Thunb. Using High Speed Counter-Current Chromatography (HSCCC and Prep-HPLC Guided by DPPH-HPLC Experiments

    Directory of Open Access Journals (Sweden)

    Daijie Wang

    2017-02-01

    Full Text Available In this work, the n-butanol extract from leaves of Lonicera japonica Thunb. (L. japonica was reacted with DPPH and subjected to a HPLC analysis for the guided screening antioxidants (DPPH-HPLC experiments. Then, nine antioxidants, including flavonoid glycosides and caffeoylquinic acid derivatives, were isolated and purified from leaves of L. japonica using high speed counter-current chromatography (HSCCC and prep-HPLC. The n-butanol extract was firstly isolated by HSCCC using methyl tert-butyl ether/n-butanol/acetonitrile/water (0.5% acetic acid (2:2:1:5, v/v, yielding five fractions F1, F2 (rhoifolin, F3 (luteoloside, F4 and F5 (collected from the column after the separation. The sub-fractions F1, F4 and F5 were successfully separated by prep-HPLC. Finally, nine compounds, including chlorogenic acid (1, lonicerin (2, rutin (3, rhoifolin (4, luteoloside (5, 3,4-Odicaffeoylquinic acid (6, hyperoside (7, 3,5-O-dicaffeoylquinic acid (8, and 4,5-O-dicaffeoylquinic acid (9 were obtained, respectively, with the purities over 94% as determined by HPLC. The structures were identified by electrospray ionization mass spectrometry (ESI-MS, 1H- and 13C-NMR. Antioxidant activities were tested, and the isolated compounds showed strong antioxidant activities.

  1. Preparative isolation and purification of cuminaldehyde and p-menta-1,4-dien-7-al from the essential oil of Cuminum cyminum L. by high-speed counter-current chromatography.

    Science.gov (United States)

    Chen, Qinqin; Hu, Xuefang; Li, Jingming; Liu, Ping; Yang, Yang; Ni, Yuanying

    2011-03-09

    High-speed counter-current chromatography (HSCCC) technique in semi-preparative scale was successfully used in isolation and purification of cuminaldehyde and p-menta-1,4-dien-7-al from the essential oil of Cuminum cyminum L. by using a two-phase solvent system composed of n-hexane-methanol-water (5:4:1, v/v/v). The targeted compounds were isolated, collected, purified by HSCCC in the head-tail mode, and then analyzed by gas chromatography (GC). A total of 12.72 ± 0.22 mg of cuminaldehyde and 10.61 ± 0.27 mg of p-menta-1,4-dien-7-al were obtained from 50 mg of the essential oil of C. cyminum L. in less than 6 h, with purities of 95.42% and 97.21%, respectively. In addition to GC-EI/MS, the identity of the cuminaldehyde was further confirmed with the retention time using the method of standard addition, while, the structural identification of p-menta-1,4-dien-7-al was performed with GC-EI/MS, (1)H NMR and (1)H-(1)H COSY.

  2. Separation and preparation of 6-gingerol from molecular distillation residue of Yunnan ginger rhizomes by high-speed counter-current chromatography and the antioxidant activity of ginger oils in vitro.

    Science.gov (United States)

    Gan, Zhilin; Liang, Zheng; Chen, Xiaosong; Wen, Xin; Wang, Yuxiao; Li, Mo; Ni, Yuanying

    2016-02-01

    Molecular distillation residue (MD-R) from ginger had the most total phenol content of 247.6mg gallic acid equivalents per gram (GAE/g) among the ginger oils. High-speed counter-current chromatography (HSCCC) technique in semi-preparative scale was successfully performed in separation and purification of 6-gingerol from MD-R by using a two-phase solvent system composed of n-hexane-ethyl acetate-methanol-water (10:2:5:7, v/v/v/v). The target compound was isolated, collected, purified by HSCCC in the head-tail mode, and then analyzed by HPLC. A total of 90.38±0.53mg 6-gingerol was obtained from 600mg MD-R, with purity of 99.6%. In addition, the structural identification of 6-gingerol was performed by EI/MS, (1)H NMR and (13)C NMR. Moreover, the orders of antioxidant activity were vitamin E (VE)>supercritical fluid extraction oleoresin (SFE-O)=MD-R=6-gingerol>molecular distillation essential oil (MD-EO) and butylated hydroxytoluene (BHT)=VE>6-gingerol>MD-R=SFE-O>MD-EO, respectively in 2,2-diphenyl-1-picrylhydrazyl radical (DPPH) scavenging and β-Carotene bleaching.

  3. 高速逆流色谱分离制备胡椒中的胡椒碱%Preparative Separation and Purification of Piperine from Piper nigrum Linn.by High-speed Counter-current Chromatography

    Institute of Scientific and Technical Information of China (English)

    王晓; 苑金鹏; 耿岩玲; 李福伟; 王岱杰; 刘建华

    2008-01-01

    利用高速逆流色谱从胡椒粗提物中分离制备其主要成分胡椒碱,两相溶剂系统为石油醚-乙酸乙酯-甲醇-水(体积比1:0.8:0:0.8),上相为固定相,下相为流动相.从300 g的粗提物中经过一次分离得到纯度为99.1%的胡椒碱65.2 mg,其化学结构由EI-MS、1H NMR和13CNMR鉴定.%Piperine,a major plant alkaloid presenting in pepper,was successfully separated and purified from the crude extract of Piper nigrum Linn.by high-speed counter-current chromatography(HSCCC)with a two-phase solvent system composed of petroleum ether(60-90℃)-ethyl acetate-methanol-water(1:0.8:1:0.8,volume ratio).The upper phase was used as stationary phase,while the lower phase was used as mobile phase.From 300 mg of crude extract,65.2 rag of piperine was obtained at 99.1% purity in one-step separation.The structure of the target compound was identified by EI-MS,1H NMR and 13C NMR.

  4. One-step separation and purification of two chromones and one pyrone from Aloe barbadensis Miller: a comparison between reversed-phase flash chromatography and high-speed counter current chromatography.

    Science.gov (United States)

    Zhong, Jia-Sheng; Wan, Jin-Zhi; Ding, Wen-Jing; Wu, Xiao-Fang; Xie, Zhi-Yong

    2014-01-01

    Chromones and pyrones are the major secondary metabolites of Aloe barbadensis Miller. As they are minor components of the plant, an efficient purification procedure for them is of great importance for promoting their pharmacological studies. To develop efficient methods for one-step separation and purification of two chromones (5-((S)-2'-oxo-4'-hydroxypentyl)-2-hydroxymethylchromone (1) and 5-((4E)-2'-oxo-pentenyl)-2-hydroxymethylchromone (3)) and one pyrone (aloenin aglycone (2)) from A. barbadensis via reversed-phase flash chromatography (RP-FC) and high-speed counter current chromatography (HSCCC). The RP-FC separation was performed using methanol:water (26:74, v/v) as the mobile phase at a flow rate of 20 mL/min. A solvent system composed of dichloromethane:methanol:water (3:1.5:1, v/v/v) was used for the HSCCC separation, at a flow rate of 2.0 mL/min. A one-step RP-FC operation within 110 min was successfully used for the purification of compounds 1 (27.9 mg, 96.5%), 2 (32.4 mg, 98.2%) and 3 (4.1 mg, 99.0%) from 129 mg of crude sample, and a one-step HSCCC separation within 95 min was successfully implemented for the purification of compounds 1 (31.1 mg, 97.6%), 2 (35.8 mg, 96.7%) and 3 (2.7 mg, 98.1%) from 134 mg of crude sample. The developed procedures were efficient, with low cost and high yield, which would afford sufficient amounts of high-purity compounds for chromatographic purposes and pharmacological activity screening. Copyright © 2014 John Wiley & Sons, Ltd.

  5. Preparative Separation of Two glycosides from Swertia Mussotti by High-Speed Counter-Current Chromatography%高速逆流色谱分离制备川西獐牙菜中两种苷类化合物

    Institute of Scientific and Technical Information of China (English)

    陈涛; 贾静; 王萍; 尤进茂; 刘永军; 李玉林

    2012-01-01

    A high performance method for isolation and purification of two glycosides from Swertia mussotti was successfully established by utilizing high-speed counter-current chromatography ( HSCCC). Separation was performed with a two-phase solvent system composed of n-butanol-chloroform-methanol-water (3.4:8:5 :6,v/v). 1-O-primevenosyl-3,7, 8-trimethoxyxanthone (11 mg) and isoorientin (24 mg) were isolated and purified in one-step elution from 100 mg crude sample under the conditions of a flow rate 1.5 mL/min in the initial 210 min followed by 2.5 mL/min,800 r/min and the detection wavelength of 254 run. HPLC analysis showed that the purity of two compounds was over 99%. Their chemical structures were confirmed by UV,1H- and 13C NMR.%采用高速逆流色谱从川西獐牙菜中分离制备了两种高纯度苷类化合物.以正丁醇-氯仿-甲醇-水(3.4∶8∶5∶6,v/v)为溶剂系统,主机转速为800 rpm,流速:O~210 min,1.5mL/min;210 ~360m in,2.5 mL/min,检测波长254 nm的条件下进行分离制备,在360 min内从100 mg样品中一步分离制备得到1-O-樱草糖-3,7,8-三甲氧基(口山)酮(Ⅰ,11 mg)和异荭草苷(Ⅱ,24 mg).经HPLC检测,两个化合物的纯度均在99%以上,结构由UV、1H和13C NMR鉴定.

  6. Separation of Catechin and Epicatechin from Persimmon by High Speed Counter Current Chromatography%高速逆流色谱法分离制备柿子中儿茶素及表儿茶素

    Institute of Scientific and Technical Information of China (English)

    郭琳博; 李宇华; 周婧; 岳溪; 陈湘宁

    2012-01-01

    采用HP2MGL大孔树脂对柿子中的儿茶素类物质进行初步分离,用高速逆流色谱进一步分离纯化柿子中的(-)-儿茶素、(-)-表儿茶素.结果表明,在以正丁醇-乙酸乙酯-水(体积比为1∶2∶3)组成的溶剂体系,上相为固定相,下相为流动相,转速800 r/min,流速1 mL/min的条件下进行HSCCC制备,经高效液相法测定,从58mg样品中分离出7.25 mg(-)-儿茶素和0.43 mg(-)-表儿茶素,纯度分别为98.3%和97.9%.%HP2MGL macroporous resin was adopted to separate catechin and epicatechin, and then High-speed Counter Current Chromatography instrument was used for further separation and purification. The separation conditions were 800 r/min rotated rate, 1 mL/min flow rate in the solvent system was composed of normal butanol-ethyl acetate-wa-ter(1:2:3,V:V:V); the upper was used as the stationary phase and the lower phase was used as the mobile phase. The results indicated that 7.25 mg catechin and 0.43 mg epicatechin could be obtained with 58 mg persimmon extraction by HSCCC at the above conditions. The purity of catechin and epicatechin was individually 98.3% and 97.9% by High Performance Liquid Chromatographic analysis.

  7. Preparative separation and identification of novel subsidiary colors of the color additive D&C Red No. 33 (Acid Red 33) using spiral high-speed counter-current chromatography.

    Science.gov (United States)

    Weisz, Adrian; Ridge, Clark D; Mazzola, Eugene P; Ito, Yoichiro

    2015-02-06

    Three low-level subsidiary color impurities (A, B, and C) often present in batches of the color additive D&C Red No. 33 (R33, Acid Red 33, Colour Index No. 17200) were separated from a portion of R33 by spiral high-speed counter-current chromatography (HSCCC). The separation involved use of a very polar solvent system, 1-BuOH/5mM aq. (NH4)2SO4. Addition of ammonium sulfate to the lower phase forced partition of the components into the upper phase, thereby eliminating the need to add a hydrophobic counterion as was previously required for separations of components from sulfonated dyes. The very polar solvent system used would not have been retained in a conventional multi-layer coil HSCCC instrument, but the spiral configuration enabled retention of the stationary phase, and thus, the separation was possible. A 1g portion of R33 enriched in A, B, and C was separated using the upper phase of the solvent system as the mobile phase. The retention of the stationary phase was 38.1%, and the separation resulted in 4.8 mg of A of >90% purity, 18.3mg of B of >85% purity, and 91 mg of C of 65-72% purity. A second separation of a portion of the C mixture resulted in 7 mg of C of >94% purity. The separated impurities were identified by high-resolution mass spectrometry and NMR spectroscopic techniques as follows: 5-amino-3-biphenyl-3-ylazo-4-hydroxy-naphthalene-2,7-disulfonic acid, A; 5-amino-4-hydroxy-6-phenyl-3-phenylazo-naphthalene-2,7-disulfonic acid, B; and 5-amino-4-hydroxy-3,6-bis-phenylazo-naphthalene-2,7-disulfonic acid, C. The isomers A and B are compounds reported for the first time. Application of the spiral HSCCC method resulted in the additional benefit of yielding 930 mg of the main component of R33, 5-amino-4-hydroxy-3-phenylazo-naphthalene-2,7-disulfonic acid, of >97% purity. Published by Elsevier B.V.

  8. Preparative separation and identification of novel subsidiary colors of the color additive D&C Red No. 33 (Acid Red 33) using spiral high-speed counter-current chromatography☆

    Science.gov (United States)

    Weisz, Adrian; Ridge, Clark D.; Mazzola, Eugene P.; Ito, Yoichiro

    2015-01-01

    Three low-level subsidiary color impurities (A, B, and C) often present in batches of the color additive D&C Red No. 33 (R33, Acid Red 33, Colour Index No. 17200) were separated from a portion of R33 by spiral high-speed counter-current chromatography (HSCCC). The separation involved use of a very polar solvent system, 1-BuOH/5 mM aq. (NH4)2SO4. Addition of ammonium sulfate to the lower phase forced partition of the components into the upper phase, thereby eliminating the need to add a hydrophobic counterion as was previously required for separations of components from sulfonated dyes. The very polar solvent system used would not have been retained in a conventional multi-layer coil HSCCC instrument, but the spiral configuration enabled retention of the stationary phase, and thus, the separation was possible. A 1 g portion of R33 enriched in A, B, and C was separated using the upper phase of the solvent system as the mobile phase. The retention of the stationary phase was 38.1%, and the separation resulted in 4.8 mg of A of >90% purity, 18.3 mg of B of >85% purity, and 91 mg of C of 65–72% purity. A second separation of a portion of the C mixture resulted in 7 mg of C of >94% purity. The separated impurities were identified by high-resolution mass spectrometry and NMR spectroscopic techniques as follows: 5-amino-3-biphenyl-3-ylazo-4-hydroxy-naphthalene-2,7-disulfonic acid, A; 5-amino-4-hydroxy-6-phenyl-3-phenylazo-naphthalene-2,7-disulfonic acid, B; and 5-amino-4-hydroxy-3,6-bis-phenylazo-naphthalene-2,7-disulfonic acid, C. The isomers A and B are compounds reported for the first time. Application of the spiral HSCCC method resulted in the additional benefit of yielding 930 mg of the main component of R33, 5-amino-4-hydroxy-3-phenylazo-naphthalene-2,7-disulfonic acid, of >97% purity. PMID:25591404

  9. 高速逆流色谱分离纯化苦豆子生物碱%Separation of alkaloids from sophora alopecuroides L.by high speed counter-current chromatography

    Institute of Scientific and Technical Information of China (English)

    朱桂花; 杨晋

    2011-01-01

    应用高速逆流色谱分离纯化了苦豆子中的生物碱。以氯仿-甲醇-0.08mol/LKH2PO4(27:20:13,v/v/v)为溶剂体系,以上相为固定相,下相为流动相,分离得到纯度分别为96.37%及98.10%的金雀花碱及槐定碱。以氯仿-甲醇-0.08mol/LKH2PO4(27:20:21,v/v/v,盐溶液pH6.50)为溶剂体系,分离得到纯度为92.53%的氧化苦参碱。分离所得组分用标准品进行对照,用反相高压液相色谱进行分析。该法有效改善了溶剂体系的两相乳化情况,具有简便、快速、产物纯度高的优点。%High speed counter current chromatography(HSCCC) was used to isolate and purify alkaloids from Sophora alopecuroides L.A two-phase solvent system composed of chloroform-methanol-0.08 mol/L KH2PO4(27:20:13,v/v/v) was selected.The lower phase was used as the mobile phase and the upper phase was used as the stationary phase.Under the optimized conditions,cytisine with the purity of 96.37% and sophoranol with the purity of 98.10% were obtained.Oxymatrine with the purity of 92.53% were obtained with another two-phase solvent system composed of chloroform-methanol-0.08 mol/LKH2PO4(27:20:17,v/v/v,saline solution pH=6.50).The separated fractions are identified with standard samples and analyzed using HPLC.The method can effectively improve solvent system emulsification.The advantages of the method is simple,rapid and high purity samples.

  10. Isolation of Alkaloids from Corydalis saxicola by High-speed Counter-current Chromatography%高速逆流色谱法分离岩黄连中的生物碱类成分

    Institute of Scientific and Technical Information of China (English)

    程轩轩; 杨得坡; 王冬梅; 蒋林

    2011-01-01

    目的:从岩黄连的粗提物中快速分离生物碱类成分.方法:采用高速逆流色谱技术,以正丁醇-乙酸乙酯-水-甲酸(5∶1∶5∶0.01)和正丁醇-乙酸乙酯-甲醇-水-甲酸(5∶5∶1∶9∶0.05)作为两相溶剂系统分离岩黄连中的主要生物碱.结果:经过连续三次色谱分离,从岩黄连的正丁醇粗提物(300 mg)中得到6个纯度较高的生物碱,分别为:scoulerine(3.6 mg,质量分数:71%)、isocorydine(9.2mg,质量分数:92%)、dehydrocheilanthifoline(5.5 mg,质量分数:85%)、dehydrocavidine(7.5 mg,质量分数:76%)、palmatine(20.4 mg,质量分数:90%)、berberine(20.9 mg,质量分数:97%).结论:采用高速逆流色谱法制备分离岩黄连中的生物碱,省时、方便、产物得率和纯度较高.%Objective:To develop a method for the rapid isolation of alkaloids from the crude extract of Corydalis saxicola. Methods :High-speed counter-current chromatography ( HSCCC) was applied for the separation of alkaloids from Corydalis saxicola,with the biphase solvent systems comprised n-butanol-ethyl acetate-water-formic acid (5:1:5:0.01) and n-butanol-ethyl acetate-methanol-wa-ter-fonnic acid (5:3:1:9:0.05). Results: About 300 mg of crude extract was isolated by HSCCC,yielding 3. 6 mg of scoulerine,9.2 mg of isocorydine.5.5 mg of dehydrocheilanthifoline,7.5 mg of dehydrocavidine,20.4 mg of palmatine and 20. 9 mg of berberine,with purities of 71% ,92% ,85% ,76% ,90% ,97% ,respectively. Conclusion:It is time-saving and simple to isolate alkaloids from Corydalis saxicola by HSCCC with high yields and purities.

  11. Optimization of the Ultrasonic-Assisted Extraction of Bioactive Flavonoids from Ampelopsis grossedentata and Subsequent Separation and Purification of Two Flavonoid Aglycones by High-Speed Counter-Current Chromatography

    Directory of Open Access Journals (Sweden)

    Hongbing Zhang

    2016-08-01

    Full Text Available The fermented leaf of Ampelopsis grossedentata has been used as a beverage and folk medicine called “vine tea” in the southern region of China. In this paper, the optimum extraction conditions for the maximum recovery amounts of total flavonoids (TF, dihydromyricetin (DMY, myricitrin (MYG and myricetin (MY from natural Ampelopsis grossedentata leaves subjected to ultrasonic-assisted extraction (UAE were determined and optimized by using response surface methodology. The method was employed by the Box–Behnken design (BBD and Derringer’s desirability function using methanol concentration, extraction time, liquid/solid ratio as factors and the contents of TF, DMY, MYG and MY as responses. The obtained optimum UAE conditions were as follows: a solvent of 80.87% methanol, an extraction time of 31.98 min and a liquid/solid ratio of 41.64:1 mL/g. Through analysis of the response surface, it implied that methanol concentration and the liquid/solid ratio had significant effects on TF, DMY, MYG and MY yields, whereas extraction time had relatively little effects. The established extraction and analytical methods were successfully applied to determine the contents of the total flavonoids and three individual flavonoids in 10 batches of the leaf samples of A. grossedentata from three counties in Fujian Province, China. The results suggested the variability in the quality of A. grossedentata leaves from different origins. In addition, high purities of dihydromyricetin and myricetin were simultaneously separated and purified from the extract subjected to optimized UAE, by high-speed counter-current chromatography using a solvent system of N-hexane–ethyl acetate–methanol–water (1:3:2:4; v/v/v/v. In a single operation, 200 mg of the extract were separated to yield 86.46 mg of dihydromyricetin and 3.61 mg of myricetin with the purity of 95.03% and 99.21%, respectively. The results would be beneficial for further exploiting the herbal products and

  12. Isolation and preparation of gallic acid from Terminalia chebula Retz. with high-speed counter-current chromatography%高速逆流色谱法分离制备中药诃子中的没食子酸

    Institute of Scientific and Technical Information of China (English)

    李忠琴; 李秋云; 江兴龙; 张坤; 关瑞章

    2014-01-01

    A separation method based on high-speed counter-current chromatography ( HSCCC)has been established for the isolation and preparation of gallic acid from the ethanol extract of Terminalia chebula Retz. After comparing five kinds of solvent protocols of HSCCC, the two-phase system of n-hexane-ethyl acetate-methanol-water(1:5:1:5,v/v/v/v)was final-ly chosen as the operating solvent of HSCCC for the separation of gallic acid,in which the low-er phase was used as the mobile phase and the upper phase as stationary phase. The detection in the experiments was performed with an ultraviolet detector at 254 nm. Under the conditions of rotation speed of 850 r/min,lower phase flow rate of 2 mL/min,four peaks(Ⅰ/Ⅱ/Ⅲ/Ⅳ) were displayed on HSCCC chromatogram. Among them,only peak Ⅲ contained a large amount of gallic acid( about 96. 40%),which was confirmed by electrospray ionization mass spectrom-etry( ESI-MS)and high performance liquid chromatographic( HPLC)analysis. As much as 8. 6 mg of gallic acid was obtained from 100 mg of the ethanol extract of Terminalia chebula Retz., indicating the method is simple,robust and efficient for the preparation of gallic acid.%利用高速逆流色谱法从100 mg诃子醇提物中一次性分离制备得到8.6 mg没食子酸。通过分析型高速逆流色谱对5种溶剂系统进行筛选,确定以正己烷-乙酸乙酯-甲醇-水(体积比为1:5:1:5)为两相溶剂体系并放大到制备型上,以上相为固定相,下相为流动相,在主机转速850 r/min、流动相流速2 mL/min、检测波长254 nm 的条件下进行分离制备,获得4个分离峰(组分Ⅰ、Ⅱ、Ⅲ、Ⅳ)。经高效液相色谱检测,按照面积归一法计算,其中组分Ⅲ的纯度达96.40%。经电喷雾电离质谱分析,并结合与没食子酸标准品的高效液相色谱测定结果的对比,确定组分Ⅲ为没食子酸。该方法简便、快速、重复性好,适合于诃子中没食子酸的分离制备。

  13. Study on the Separation of Monoterpenes from Piper nigrum L·by High-speed Counter-current Chromatography%高速逆流色谱分离制备白胡椒中单萜类化合物

    Institute of Scientific and Technical Information of China (English)

    蒋志国; 陈文学; 刘四新

    2011-01-01

    Three monoterpenes were prepared, isolated and purified from Piper nigrum L.. by high-speed counter-current chromatography (HSCCC) . A two-phase solvent system composed of TBME-methanol-water (2: 1: 1, v/v/v) was used. The upper phase was stationary phase and lower phase was mobile phase. By one-step elution, under the conditions of a flow rate of 2.5 mL/min and 900 r/min, 35 mg of 3,7-dimethyloct-2E-en-1,6,7-triol, 55 mg of p-menthane-l ,2,8-triol-2-O-β-D-glucopyranoside and 40 mg of 5-hydroxy bornyl-2-O-β-D-glucopyranoside was obtained from 2. 76 mg of the butanol extract of Piper nigrum L. , the purities was over 95.0% detected by high performance liquid chromatography with evaporative light scattering detection. The obtained fractions were analyzed by high performance liquid chromatography ( HPLC), and identified by mass spectrometry ( MS), 1 H-nuclear magnetic resonance (NMR) and 13C-NMR. The results indicated that HSCCC is a powerful technique for the purification of monoterpenes from Piper nigrum L. with high productive capacity and high efficiency.%应用高速逆流色谱法分离制备了白胡椒中3种单萜类化合物.以V(叔丁基甲基醚):V(甲醇):V(水)=2:1:1为两相溶剂系统,上相为固定相,下相为流动相,在主机转速900 r/rain、流动相流速2.5 mI/min条件下,从2.76 g样品中一步分离制备得到3,7-二甲基-2-辛烯-1,6,7-三醇35 mg,对薄荷烷-1,2,8-三醇-2-O-β-D 葡萄糖苷55mg,5-羟基龙脑-2-O-β-D葡萄糖苷40mg,经高效液相蒸发光散射检测器(HPLC-ELSD)检测纯度均达95.0%以上,各化合物结构经质谱和核磁共振氢谱、碳谱鉴定.研究结果表明,利用该方法可以对白胡椒中的单萜类化合物进行快速的分离和纯化,且制备量大,分离效率高.

  14. Rapid Preparation of Naringin and Neohesperidin with High Purities from Fructus Aurantii by High-speed Counter-current Chromatography%采用高速逆流色谱法快速制备枳壳中高纯度柚皮苷和新橙皮苷的研究

    Institute of Scientific and Technical Information of China (English)

    胡昌盛; 彭金咏

    2013-01-01

    目的 建立一种从枳壳中快速分离制备高纯度柚皮苷和新橙皮苷的方法.方法 以高速逆流色谱(High-speed counter-current chromatography,HSCCC)对枳壳大孔吸附树脂纯化物进行分离纯化,以乙酸乙酯∶正丁醇∶水(2:1:3)为两相溶剂系统,上相为固定相,下相为流动相,流速2.0ml/min,主机转速800r/min,检测波长280 nm.结果 按此分离条件经一步洗脱从500 mg枳壳粗提物中得到210 mg和122 mg纯度高于99%的柚皮苷和新橙皮苷.结论 该法操作简便、产品纯度高、适合于大规模制备.

  15. Isolation of terpenoids from Pimpinella anisum essential oil by high-performance counter-current chromatography.

    Science.gov (United States)

    Skalicka-Woźniak, Krystyna; Walasek, Magdalena; Ludwiczuk, Agnieszka; Głowniak, Kazimierz

    2013-08-01

    High-performance counter-current chromatography was successfully used for the isolation and purification of terpenoid compounds from the essential oil of Pimpinella anisum L. A two-phase solvent system composed of n-heptane/methanol/ethyl acetate/water (5:2:5:2, v/v/v/v) was suitable for the purification of linalool, terpinen-4-ol, α-terpineol, p-anisaldehyde, while n-heptane/methanol (1:1, v/v) was used for the isolation of anethole and foeniculin. A scale-up process from analytical to preparative was developed. Additionally, a stepwise gradient elution was applied and instead of two different runs, 40 min each, one 80 min separation was performed; although the time of separation remains the same, it was possible to repeat the efficiency even if the water-containing mobile phase was changed to a nonaqueous system. The obtained essential oil, as well as purified compounds, was analyzed by GC. A total of 0.64 mg of linalool, 0.52 mg of terpinen-4-ol, 0.10 mg of α-terpineol, 0.62 mg of p-anisaldehyde, 15 mg of anethole, and 2.12 mg of foeniculin were obtained from 210 mg of the essential oil of P. anisum L. in a short time with purities of 99, 98, 94, 93.54, 93, and 93.6%, respectively.

  16. 高速逆流色谱分离纯化连翘中的两对立体异构体%Preparative Isolation and Purification of Two Pairs of Stereomer from the Fruits of Forsythia suspensa by High-speed Counter-current Chromatography

    Institute of Scientific and Technical Information of China (English)

    段文娟; 耿岩玲; 庄会永; 傅茂润; 刘建华; 王晓

    2011-01-01

    Two pairs of stereomeric lignan, namely (+) pinoresinol monomethyl elher-β-D-glueoside and phillyrin, (+) pinoresinol-β-D-glucoside and (+) epipinoresinol-£-/}-glucoside, were successfully isolated and purified from the fruits of Forsytkia suspensa by high-speed counter-current chromatography (HSCCC) using two-phase solvent systems with composed of ethyl acetate-n-butanol-melhanol-water (5:0.1:1:5, volume ratio) and ethyl acetate-n-butanol-methanol-water (5:0.5:1:5, volume ratio), respectively. The purities of the isolated compounds were all above 97 % determined by high-performance liquid chromatography (HPLC) and their structures were confirmed by electrospray ionization MS (ESI-MS),1HNMR, and 13C NMR.%应用高速逆流色谱法(HSCCC)分离纯化连翘果实中的两对木脂素类立体异构体.分别用乙酸乙酯-正丁醇-甲醇-水(体积比5∶0.7∶1∶5)和乙酸乙酯-正丁醇-甲醇-水(体积比5∶0.5∶1∶5)为两相溶剂体系,在转速为800r/min、流速为1.5 mL/min、检测波长为254 nm的条件下进行分离,所得馏分经高效液相色谱(HPLC)检测纯度,电喷雾电离质谱(ESI-MS)和碳核磁共振波谱(13C NMR)鉴定化合物的结构.

  17. ORGANIC-HIGH IONIC STRENGTH AQUEOUS SOLVENT SYSTEMS FOR SPIRAL COUNTER-CURRENT CHROMATOGRAPHY: GRAPHIC OPTIMIZATION OF PARTITION COEFFICIENT.

    Science.gov (United States)

    Zeng, Yun; Liu, Gang; Ma, Ying; Chen, Xiaoyuan; Ito, Yoichiro

    2013-01-10

    A new series of organic-high ionic strength aqueous two-phase solvents systems was designed for separation of highly polar compounds by spiral high-speed counter-current chromatography. A total of 21 solvent systems composed of 1-butanol-ethanol-saturated ammonium sulfate-water at various volume ratios are arranged according to an increasing order of polarity. Selection of the two-phase solvent system for a single compound or a multiple sample mixture can be achieved by two steps of partition coefficient measurements using a graphic method. The capability of the method is demonstrated by optimization of partition coefficient for seven highly polar samples including tartrazine (K=0.77), tryptophan (K=1.00), methyl green (K= 0.93), tyrosine (0.81), metanephrine (K=0.89), tyramine (K=0.98), and normetanephrine (K=0.96). Three sulfonic acid components in D&C Green No. 8 were successfully separated by HSCCC using the graphic selection of the two-phase solvent system.

  18. 粉被玛利亚霉中天然色素的高速逆流色谱法分离制备及质谱分析%Natural Pigments of Mariannaea puinosa Preparation with High-Speed Counter-Current Chromatography and Analysis with ESI-MS

    Institute of Scientific and Technical Information of China (English)

    王小董; 张德龙; 耿广青; 李康乐; 胡丰林

    2011-01-01

    High-speed counter-current chromatography was used for separation and purification of natural pigment from the mycelia of Mariannaea puinosa. The tow-phase solvent system was ethyl acetate-n-butanol-methanol-water (10: 3: 3: 10). The upper phase was stationary phase and the lower phase was mobile phase. The flow-rate of the mobile phase was 2.0 mL/min and the rotation speed was 850 r/min. The effluent of the column was monitored with a UV detector at 340 nm. The purity of the pigment fraction was evaluated by high-performance liquid chromatography (HPLC). High resolution MS analysis revealed that the molecular formula of the compound was C26H32O9, which was possibly a new compound according to the searching results of Chapman & Hall natural products database.%采用高速逆流色谱法分离制备粉被玛利亚霉菌丝体甲醇提取物中的天然色素.溶剂体系为V(乙酸乙酯)∶V(正丁醇)∶V(甲醇)∶V(水)=10∶3∶3∶10,以其下相为流动相,上相为固定相,转速850 r/min,流速为2mL/min,紫外检测波长340 nm.所得色素产物的纯度经高效液相色谱分析为95.3%(蜂面积归一化法),其分子武由高分辨ESI-MS确认为C26H32O9.经天然产物数据库查询,没有发现与该分子式匹配的化合物,因此该色素可能为一新化合物.

  19. 离子液体优化高速逆流色谱法分离槐花中的黄酮类化合物%Preparative Separation of Flavones from Sophora japonica by High-Speed Counter-current Chromatography

    Institute of Scientific and Technical Information of China (English)

    朱晓娜; 曹伟伟; 李明静

    2012-01-01

    Two flavones were isolated and purified from Sophora japonica by high-speed counter-current chromatography ( HSCCC) for the first time. The separation of the two flavones was improved by using ionic liquid. A two-phase solvent system composed of n-hexane : ethyl acetate : ethanol : water : acetic acid (1:1:1:1:0. 05, v/v) was used. The results indicated that 18.2 mg of rutin and 9.6 mg of quercetin with their purities over 97% were obtained from 50 mg crude extract of Sophora japonica. By adding ionic liquid, the peak retention time was shorten to 55 min from the previous 85 min, the peak resolution was increased from 0. 9 to 1.8. Hence,the addition of ionic liquid into HSCCC system contributed to achieve complete separation of these two flavones. The results can be used as the basis for future research.%应用高速逆流色谱法首次从槐花中一步分离出2种黄酮类化合物,并利用离子液体提高分离效果.以正己烷-乙酸乙酯-乙醇-水-冰醋酸(1:1:1:1:0.05,v/v)为两相溶剂体系,从50 mg槐花粗提物中一步分离得到芦丁18.2 mg,槲皮素9.6 mg,其纯度均在97%以上.加入离子液体1-丁基-3-甲基咪唑六氟化硼酸([BMIM][PF6]),使出峰时间由原来的85 min提前到55 min,分离度由0.9提高到1.8,达到完全分离,分离效果得到明显提高,为离子液体在高速逆流色谱中的进一步应用提供依据.

  20. Isolation of 6-gingerol, 8-gingerol and 6-shogaol from dry rhizome of Zingiber officinale Rosc.by silica gel column chromatography and high-speed counter-current chromatagraphy%高速逆流色谱结合硅胶柱色谱法分离制备干姜中的6-姜酚、8-姜酚、6-姜烯酚

    Institute of Scientific and Technical Information of China (English)

    徐美霞; 王晓; 刘建华; 耿岩玲; 王岱杰; 刘峰

    2013-01-01

    通过实验建立了高速逆流色谱(HSCCC)结合硅胶柱色谱法分离制备干姜中6-姜酚、8-姜酚和6-姜烯酚的方法.干姜样品采用乙酸乙酯超声提取,提取物经过硅胶柱色谱粗分,选取其中A3和A4两个馏分进行高速逆流色谱分离,所得单一成分采用高效液相色谱(HPLC)检测纯度,并采用电喷雾质谱(ESI-MS)、核磁共振氢谱(1H NMR)对所得化合物的结构进行鉴定.研究结果表明,该方法简便快捷,所得产物纯度高、制备量大、分离效率好.%We constructed the method of isolating 6-gingerol, 8-gingerol and 6-shogaol from dry rhizome of Zingiber officinale Rose, by silica gel column chromatography and high-speed counter-current chromatagraphy based on experiments. We extracted the samples of Zingiber officinale Rose, by ethyl acetate ultrasonic extraction and then coarsely treated them by silica gel column chromatography. We further selected fraction A3 and A4 to be separated by high-speed counter-current chromatography( HSCCC). The purity of the obtained single ingredient was detected by high-performance liquid chromatography(HPLC) and the structure of the obtained compound was identified by electrospray ionization(ESI-MS) and 1H-NMR. Results show that the method has such positives as simplicity, rapidity, high-purity products, large amount of preparation and high-efficiency separation.

  1. 硅胶柱色谱结合高速逆流色谱法分离纯化丹参中丹参酮%Separation and purification of tanshinone from Salvia miltiorrhiza by combination of silica gel and high-speed counter-current chromatography

    Institute of Scientific and Technical Information of China (English)

    蓝天凤; 于宗渊; 王岱杰; 王晓; 管仁军

    2011-01-01

    Objective To develop a method for separation and purification of tanshinone from Salvia miltiorrhiza by combination of silica gel and high-speed counter-current chromatography (HSCCC). Methods The crude extract of S. miltiorrhiza was separated by silica gel chromatography and Fl and F2 were obtained. Then, Fl and F2 were separated by HSCCC with a two-phase solvent system composed of petroleum ether-methanol-water (4: 3: 4: 2 and 8: 5: 8: 3), respectively. The lower phase was used as the mobile phase with a flow rate of 2.0 mL/min, while the apparatus rotated at 850 r/min and the eluates were detected at 254 nm. The structures of the target compounds were identified by ESI-MS and NMR. Results From 80 mg of F1, three compounds with tanshinone Ⅰ (14 mg), dihydrotanshinone Ⅰ (22 mg), and tanshinone ⅡA (26 mg) were obtained. And from 80 mg of F2,dihydrotanshinone (11 mg), trijuganone B (15 mg), and cryptotanshinone (30 mg) were obtained. The purities of these six compounds determined by HPLC were all over 96%, respectively. Conclusion Combination of silica gel and HSCCC is an efficient method for separation of tanshinone from S. miltiorrhiza.%目的 建立硅胶柱色谱结合高速逆流色谱(HSCCC)法分离纯化丹参中丹参酮的方法.方法 丹参粗提物经硅胶柱色谱分离,得到组分F1、F2,分别采用石油醚-醋酸乙酯-甲醇-水(4:3:4:2)、(8:5:8:3)的溶剂系统进行HSCCC分离,下相为流动相,体积流量2.0 mL/min,转速850 r/min,检测波长254 nm,所得产物采用ESI-MS、NMR进行结构鉴定.结果 80 mg组分F1分离得到丹参酮I(14 mg)、二氢丹参酮I (22 mg)、丹参酮IIA (26 mg); 80 mg组分F2分离得到二氢丹参酮(11 mg)、三叶鼠尾酮B (15 mg)、隐丹参酮(30 mg); 6个化合物进行HPLC分析,质量分数均大于96%.结论 硅胶柱色谱结合HSCCC是一种有效的分离制备丹参酮的方法.

  2. Separation of Anthocyanins in Echinacea Purpurea Flower by High Speed Counter-current Chromatography and the Research on the Antioxidant Activity of the Anthocyanins%高速逆流色谱法分离紫锥菊花色苷及其抗氧化性研究

    Institute of Scientific and Technical Information of China (English)

    李佳银; 罗晋; 李觅路; 陆英; 刘仲华

    2012-01-01

    建立了高速逆流色谱(HSCCC)分离制备紫锥菊花色苷类化合物的方法,并对所获得的2个花色苷单体进行了体外抗氧化性实验.以新鲜紫锥菊花瓣为原料,含0.1% HCI的60%乙醇为溶剂避光冷浸提取,经乙酸乙酯萃取和D101大孔吸附树脂(100 mL,2 cm×30 cm)纯化后,得2.1g紫锥菊花色苷提取物干粉样品.以水-正丁醇-甲基叔丁基甲醚-乙腈-三氟乙酸(6∶3∶2∶1∶0.001)为HSCCC分离溶剂系统,上相为固定相,下相为流动相,流速2.0 mL/min,进样量160 mg,通过一次分离得到2种花色苷单体化合物,经HPLC检测其纯度分别达95.1% (9.8 mg)、98.2%( 14.3 mg),MS及NMR技术鉴定其结构分别为矢车菊素-3-O-β-D葡萄糖苷(化合物1)和矢车菊素-3-O-(6″-O-丙二酰-β-D葡萄糖苷)(化合物2).以Vc为对照组,对所获得的2种花色苷单体化合物进行了1,1-二苯基-2苦肼基(DPPH·)体外抗氧化性能评价,结果显示2种花色苷对DPPH·的半清除率(EC50)均小于10 mg/L,小于对照样Vc,表明2种花色苷均具有较强的自由基清除作用,且化合物1的清除能力强于化合物2.%An efficient method for the isolation and preparation of two anthocyanins, cyaniding 3-0-(β-D-giucopyranoside) (compound 1) and cyaniding 3-0-(6"-0-malonyl-β-D-glucopyranoside) (compound 2) , from Echinacea purpurea flower by high speed counter-current chromatography ( HSCCC ) was established. The fresh flower was extracted with 60% ethanol (containing 0. 1% HC1) at low temperature and dark conditions. 2. 1 g of crude sample for HSCCC was prepared after extracted with ethyl acetate and passed through an adsorbing column (2 cm x 30 cm, containing 100 mL D101 macroporous resin). Then water - n-butanol - methyl tert-butyl ether - acetonitrile - trifluoroacetic acid(6 : 3 : 2 : 1 : 0. 001) was used as the two-phase solvent system, in which the upper phase was used as the stationary phase, while the lower phase was used as the mobile phase, the

  3. Isolation of chlorogenic acid from Mutellina purpurea L. herb using high-performance counter-current chromatography.

    Science.gov (United States)

    Sieniawska, Elwira; Skalicka-Woźniak, Krystyna

    2014-01-01

    The aim of the study was to explore proper isolation conditions of chlorogenic acid from the herb of Mutelina purpurea L. - a new source of this bioactive molecule. The accelerated solvent extraction (ASE) with 40% aqueous solution of methanol combined with high-performance counter-current chromatography (HPCCC) was utilised for the efficient extraction and the separation of chlorogenic acid from the M. purpurea herb in less than 30 min. The structure of the obtained compound was confirmed by mass spectrometry and NMR analysis. The preparative HPCCC was performed using the mixture of ethyl acetate, butanol and water (4:1:5, v/v/v) in the reverse-phase mode. The chlorogenic acid was isolated from this herb for the first time, yielding 96% purity. The ASE with 40% methanol combined with HPCCC separation was proven to be a useful tool for quick and efficient isolation of chlorogenic acid from M. purpurea.

  4. Effect of counter current gas phase on liquid film

    Institute of Scientific and Technical Information of China (English)

    Shujuan LUO; Huaizhi LI; Weiyang FEI; Yundong WANG

    2009-01-01

    Liquid film flow is very important in many industrial applications. However, there are few reports about its characteristics on structured packings. Therefore, in this paper, liquid film phenomena were investigated experimentally to exploit new approaches for intensifying the performance of the structured packings. All experiments were performed at room temperature. Water and air were the working fluids. The effect of counter current gas phase on the liquid film was taken into consideration. A high speed camera, a non-intrusive measurement technique, was used. It is shown that both liquid and gas phases have strong effects on film characteristics. In the present work, liquid film width increased by 57% because of increasing liquid flow rate, while it decreased by 25% resulting from the counter current gas phase.

  5. Preparative isolation and purification of anti-tumor agent ansamitocin P-3 from fermentation broth of Actinosynnema pretiosum using high-performance counter-current chromatography.

    Science.gov (United States)

    Yao, Yuqin; Cheng, Zhihui; Ye, Haoyu; Xie, Yongmei; He, Jing; Tang, Minghai; Shen, Tao; Wang, Jiangman; Zhou, Yan; Lu, Zejun; Luo, Feng; Chen, Lijuan; Yu, Luoting; Yang, Jin-Liang; Peng, Aihua; Wei, Yuquan

    2010-05-01

    Ansamitocin P-3 is a potent anti-tumor maytansinoid found in Actinosynnema pretiosum. However, due to the complexity of the fermentation broth of Actinomycete, how to effectively separate ansamitocin P-3 is still a challenge. In this study, both analytical and preparative high-performance counter-current chromatography were successfully used to separate and purify ansamitocin P-3 from fermentation broth. A total of 28.8 mg ansamitocin P-3 with purity of 98.4% was separated from 160 mg crude sample of fermentation broth in less than 80 min with the two-phase solvent system of hexane-ethyl acetate-methanol-water (0.6:1:0.6:1, v/v/v/v). The purity and structural identification were determined by HPLC, (1)H NMR, (13)C NMR and mass spectroscopy.

  6. Predictable and linear scale-up of four phenolic alkaloids separation from the roots of Menispermum dauricum using high-performance counter-current chromatography.

    Science.gov (United States)

    Luo, Houding; Peng, Ming; Ye, Haoyu; Chen, Lijuan; Peng, Aihua; Tang, Minghai; Zhang, Fan; Shi, Jie

    2010-07-15

    This paper describes how distribution ratios were used for prediction of peak elution in analytical high-performance counter-current chromatography (HPCCC) to explore the method for separation and purification of bioactive compounds from the roots of Menispermum dauricum. Then important parameters related to HPCCC separations including solvent systems, sample concentration, sample loading volume and flow rate were optimized on an analytical Mini-DE HPCCC and finally linearly scaled up to a preparative Midi-DE HPCCC with nearly the same resolutions and separation time. Four phenolic alkaloids were for the first time obtained by HPCCC separation with a two-phase solvent system composed of petroleum ether-ethyl acetate-ethanol-water (1:2:1:2, v/v). This process produced 131.3 mg daurisolin, 197.1 mg dauricine, 32.4 mg daurinoline and 14.7 mg dauricicoline with the purity of 97.6%, 96.4%, 97.2% and 98.3%, respectively from 500 mg crude extract of the roots of M. dauricum in a one-step separation. The purities of compounds were determined by high-performance liquid chromatography (HPLC). Their structures were identified by electrospray ionization mass spectrometer (ESI-MS) and nuclear magnetic resonance (NMR).

  7. Isolamento do alcalóide ricinina das folhas de Ricinus communis (Euphorbiaceae através de cromatografias em contracorrente Isolation of the alkaloid ricinine from the leaves of Ricinus communis (Euphorbiaceae through counter-current chromatography

    Directory of Open Access Journals (Sweden)

    Ana Cristina Leite

    2005-12-01

    Full Text Available Droplet counter-current chromatography, rotation locular counter-current chromatography and high-speed counter-current chromatography were applied to the preparative separation of the alkaloid ricinine from the dichloromethane extracts of Ricinus communis leaves. The solvent system used was composed of dichloromethane-methanol-water (93:35:72 v/v/v and all techniques led to the isolation of large amounts of the alkaloid. The best result was obtained through HSCCC, since the ricinine yield was respectively 50% and 30% higher than when using RLCCC or DCCC.

  8. Mixer-settler counter-current chromatography with multiple spiral disk assembly.

    Science.gov (United States)

    Ito, Yoichiro; Clary, Robert; Sharpnak, Frank; Metger, Howard; Powell, Jimmie

    2007-11-23

    A novel system for performing high-speed counter-current chromatography has been developed for separation of biopolymers using polymer phase systems. The spiral disk assembly consisting of eight units, each equipped with over 300 mixer-settler sets, was constructed and performance evaluated in terms of retention of the stationary phase and separation efficiency. A series of experiments was performed with a polymer phase system composed of polyethylene glycol 1000 (12.5%, w/w) and dibasic potassium phosphate (12.5%, w/w) using two stable protein samples of myoglobin and lysozyme at various experimental conditions of flow rates and revolution speeds. The best results were obtained with revolution speeds of 800-1000rpm at flow rates of 0.25-0.5ml/min where the partition efficiency of several 100 theoretical plates was achieved with over 50% stationary phase retention.

  9. High speed data converters

    CERN Document Server

    Ali, Ahmed MA

    2016-01-01

    This book covers high speed data converters from the perspective of a leading high speed ADC designer and architect, with a strong emphasis on high speed Nyquist A/D converters. For our purposes, the term 'high speed' is defined as sampling rates that are greater than 10 MS/s.

  10. Preparative Separation of Catechin and Epi-Catechin by High Performance Counter-Current Chromatography%儿茶素和表儿茶素异构体的高效逆流色谱分离制备

    Institute of Scientific and Technical Information of China (English)

    成超; 尹鹭; 曹学丽; 徐静

    2012-01-01

    应用高效逆流色谱法(HPCCC)对茶叶中的儿茶素和表儿茶素两种同分异构体的分离制备方法进行研究。结果表明:以正己烷-乙酸乙酯-水(体积比1:20:20)为两相溶剂系统,上相为固定相,下相为流动相,可以实现儿茶素和表儿茶素的完全分离。采用138mL的分离柱、1g儿茶素粗提物,在120min内一次制备即可得到纯度在95%以上的表儿茶素约35mg,纯度在99%以上的儿茶素325mg,纯度90%~99%的儿茶素100mg。%High performance counter-current chromatography(HPCCC) was used for the separation and preparation of two isomers,catechin and epicatechin from crude extract of green tea.The results indicated that catechin and epicatechin could be separated completely by HPCCC using a two-phase solvent system composed of hexane,ethyl acetate and water(1:20:20,V/V) to form an upper phase as the stationary phase and a lower phase as the mobile phase.By using a 138 mL separation column,approximately 35mg of epicatechin( 95% purity) and 325mg of( 99% purity) or 100mg of(90%-99% purity) cetechin were obtained from 1 g of crude extract through one-step separation in 120 min.

  11. Separation of patuletin-3-O-glucoside, astragalin, quercetin, kaempferol and isorhamnetin from Flaveria bidentis (L.) Kuntze by elution-pump-out high-performance counter-current chromatography.

    Science.gov (United States)

    Wei, Yun; Xie, Qianqian; Fisher, Derek; Sutherland, Ian A

    2011-09-09

    Flaveria bidentis (L.) Kuntze is an annual alien weed of Flaveria Juss. (Asteraceae) in China. Bioactive compounds, mainly flavonol glycosides and flavones from F. bidentis (L.) Kuntze, have been studied in order to utilize this invasive weed, Analytical high-performance counter-current chromatography (HPCCC) was successfully used to separate patuletin-3-O-glucoside, a mixture of hyperoside (quercetin-3-O-galactoside) and 6-methoxykaempferol-3-O-galactoside, astragalin, quercetin, kaempferol and isorhamnetin using two runs with different solvent system. Ethyl acetate-methanol-water (10:1:10, v/v) was selected by analytical HPCCC as the optimum phase system for the separation of patuletin-3-O-glucoside, a mixture of hyperoside and 6-methoxykaempferol-3-O-galactoside, and astragalin. A Dichloromethane-methanol-water (5:3:2, v/v) was used for the separation of quercetin, kaempferol and isorhamnetin. The separation was then scaled up: the crude extract (ca 1.5 g) was separated by preparative HPCCC, yielding 12 mg of patuletin-3-O-glucoside at a purity of 98.3%, yielding 9 mg of a mixture of hyperoside and 6-methoxykaempferol-3-O-galactoside constituting over 98% of the fraction, and 16 mg of astragalin (kaempferol-3-O-glucoside) at a purity of over 99%. The pump-out peaks are isorhanetin (98% purity), kaemferol (93% purity) and quercitin (99% purity). The chemical structure of patuletin-3-O-glucoside and astragalin were confirmed by MS and ¹H, ¹³C NMR.

  12. Evaluation of dual flow counter-current chromatography and intermittent counter-current extraction.

    Science.gov (United States)

    Ignatova, Svetlana; Hewitson, Peter; Mathews, Ben; Sutherland, Ian

    2011-09-09

    The aim of this research is to compare two continuous extraction technologies, intermittent counter-current extraction (ICcE) and dual flow counter-current chromatography (DFCCC), in terms of loading and throughput using the GUESSmix, and show the advantages and disadvantages of the two methods. A model sample containing caffeine, vanillin, naringenin and carvone, with a total load of 11.2 g, was employed with a hexane-ethyl acetate-methanol-water (2:3:2:3) phase system to evaluate an ICcE method on a preparative (912 ml coil volume) DE-Midi instrument. While DFCCC was carried out on a specially designed preparative (561 ml coil volume) bobbin installed in a similar Midi instrument case. While similar throughputs of 7.8 g/h and 6.9 g/h were achieved for the ICcE and DFCCC methods respectively, ICcE was demonstrated to have a number of advantages over DFCCC.

  13. High speed heterostructure devices

    CERN Document Server

    Beer, Albert C; Willardson, R K; Kiehl, Richard A; Sollner, T C L Gerhard

    1994-01-01

    Volume 41 includes an in-depth review of the most important, high-speed switches made with heterojunction technology. This volume is aimed at the graduate student or working researcher who needs a broad overview andan introduction to current literature. Key Features * The first complete review of InP-based HFETs and complementary HFETs, which promise very low power and high speed * Offers a complete, three-chapter review of resonant tunneling * Provides an emphasis on circuits as well as devices.

  14. Intermittent counter-current extraction-Equilibrium cell model, scaling and an improved bobbin design.

    Science.gov (United States)

    Hewitson, Peter; Sutherland, Ian; Kostanyan, Artak E; Voshkin, Andrei A; Ignatova, Svetlana

    2013-08-16

    This paper describes an equilibrium cell model for intermittent counter-current extraction that is analytically solved for the first time for continuous sample injection between a pair of columns. The model is compared with practice for injections of a model mixture of compounds on a standard high-performance counter-current chromatography instrument giving good agreement for compound elution order and the times to maximum concentration for the eluted components. An improved design of end fittings for the counter-current chromatography bobbins is described which permits on-column switching of the mobile and stationary phases. This on-column switching successfully eliminates the displaced stationary phase seen in fractions when operating ICcE with standard flying leads and gives a 6% reduction in the retention time of compounds and improved resolution due to the elimination of the time delay required to pump the previous mobile phase from standard flying leads.

  15. Two-dimensional counter-current chromatography for the preparative separation of prenylflavonoids from Artocarpus altilis.

    Science.gov (United States)

    Lu, Yanbin; Sun, Cuirong; Wang, Yu; Pan, Yuanjiang

    2007-06-01

    A two-dimensional counter-current chromatographic system (2D-CCC) for preparative isolation and purification of three prenylflavonoids from Artocarpus altilis is presented. An upright CCC instrument (CCC1, total capacity: 1600 ml) was used as the first dimension. Effluent of interest from CCC1 was collected on-line into a 30 ml sample loop by a laboratory-prepared column-switching interface and introduced into a high-speed CCC instrument (CCC2, total capacity: 210 ml) for the second dimension separation. With this 2D-CCC system and a pair of two-phase solvent systems composed of n-hexane-ethyl acetate-methanol-water (5:5:7:3 and 5:5:6.5:3.5, v/v/v/v), which had been selected by high-speed CCC, about a 500 mg amount of the crude extract was separated, yielding 9 mg of compound 1, 28 mg of compound 2 and 78 mg of compound 3. The purities of the three prenylflavonoids were 98.7 (1), 98.3 (2) and 97.2% (3), respectively, as determined by HPLC analysis. Their chemical structures were identified by electrospray ionization MS, (1)H NMR and (13)C NMR.

  16. Counter-current CO2 purification of partially deacylated sunflower oil

    Science.gov (United States)

    High oleic sunflower oil was partially deacylated by propanolysis to produce a mixture of diglycerides and triglycerides. To remove by-product fatty acid propyl esters (FAPEs) from this reaction mixture, a liquid carbon dioxide (L-CO2) counter-current fractionation method was developed. The fracti...

  17. Counter-current carbon dioxide purification of partially deacylated sunflower oil

    Science.gov (United States)

    High oleic sunflower oil was partially deacylated by propanolysis to produce a mixture of diglycerides and triglycerides. To remove by-product fatty acid propyl esters (FAPEs) from this reaction mixture, a liquid carbon dioxide (L-CO2) counter-current fractionation method was developed. The fracti...

  18. Preparative Isolation and Purification of Five Flavonoid Glycosides and One Benzophenone Galloyl Glycoside from Psidium guajava by High-Speed Counter-Current Chromatography (HSCCC

    Directory of Open Access Journals (Sweden)

    Yindi Zhu

    2013-12-01

    Full Text Available Psidium guajava leaves have a diverse phytochemical composition including flavonoids, phenolics, meroterpenoids and triterpenes, responsible for the biological activities of the medicinal parts. In particular, flavonol glycosides show beneficial effects on type II diabetes mellitus. A simple and efficient HSCCC method has been developed for the preparative separation of five flavonoid glycosides and one diphenylmethane glycoside from P. guajava. A solvent system composed of n-hexane–ethyl acetate–methanol–water (0.7:4:0.8:4, v/v/v/v was optimized for the separation. The upper phase was used as the stationary phase, and the lower phase was used as the mobile phase. Under the optimized conditions, hyperoside (15.3 mg, isoquercitrin (21.1 mg, reynoutrin (65.2 mg, quercetin-3-O-β-D-arabinopyranoside (71.7 mg, quercetin-3-O-α-L-arabinofuranoside (105.6 mg and 2,4,6-trihydroxy-3,5-dimethylbenzophenone 4-O-(6''-O-galloyl-β-D-glucopyranoside (98.4 mg were separated from crude sample (19.8 g. The structures of all the isolates were identified by ESI-MS, 1H- and 13C-NMR analyses and their purities (>95% were determined using HPLC.

  19. Isolation and purification of nootkatone from the essential oil of fruits of Alpinia oxyphylla Miquel by high-speed counter-current chromatography.

    Science.gov (United States)

    Xie, Jianchun; Wang, Shuaibin; Sun, Baoguo; Ito, Yoichiro

    2009-11-01

    HSCCC technique in a semi-preparative-scale was successfully applied for the first time to isolation and purification of nootkatone from the essential oil of fruits of Alpinia oxyphylla Miquel. Twelve pairs of two-phase solvent systems, consisting of seven non-aqueous and five organic-aqueous solvent systems, were evaluated by HSCCC. It revealed that the separation was mainly influenced by the partition coefficient (K) of nootkatone and the separation factor (α) between nootkatone and valencene while the organic-aqueous solvent systems were more efficient than the non-aqueous systems. With the optimal two-phase solvent system composed of n-hexane-methanol-water (5:4:1, v/v) by eluting the lower phase in a head-to-tail mode, 3.1 mg of nootkatone was obtained at a purity of 92.30 % by GC-MS in one step operation from 80 mg of crude essential oil in less than 4 h. The chemical structure of nootkatone fraction was confirmed by EI-MS and (1)H NMR.

  20. High Speed Video Insertion

    Science.gov (United States)

    Janess, Don C.

    1984-11-01

    This paper describes a means of inserting alphanumeric characters and graphics into a high speed video signal and locking that signal to an IRIG B time code. A model V-91 IRIG processor, developed by Instrumentation Technology Systems under contract to Instrumentation Marketing Corporation has been designed to operate in conjunction with the NAC model FHS-200 High Speed Video Camera which operates at 200 fields per second. The system provides for synchronizing the vertical and horizontal drive signals such that the vertical sync precisely coincides with five millisecond transitions in the IRIG time code. Additionally, the unit allows for the insertion of an IRIG time message as well as other data and symbols.

  1. High speed multiphoton imaging

    Science.gov (United States)

    Li, Yongxiao; Brustle, Anne; Gautam, Vini; Cockburn, Ian; Gillespie, Cathy; Gaus, Katharina; Lee, Woei Ming

    2016-12-01

    Intravital multiphoton microscopy has emerged as a powerful technique to visualize cellular processes in-vivo. Real time processes revealed through live imaging provided many opportunities to capture cellular activities in living animals. The typical parameters that determine the performance of multiphoton microscopy are speed, field of view, 3D imaging and imaging depth; many of these are important to achieving data from in-vivo. Here, we provide a full exposition of the flexible polygon mirror based high speed laser scanning multiphoton imaging system, PCI-6110 card (National Instruments) and high speed analog frame grabber card (Matrox Solios eA/XA), which allows for rapid adjustments between frame rates i.e. 5 Hz to 50 Hz with 512 × 512 pixels. Furthermore, a motion correction algorithm is also used to mitigate motion artifacts. A customized control software called Pscan 1.0 is developed for the system. This is then followed by calibration of the imaging performance of the system and a series of quantitative in-vitro and in-vivo imaging in neuronal tissues and mice.

  2. High speed flywheel

    Science.gov (United States)

    McGrath, Stephen V.

    1991-01-01

    A flywheel for operation at high speeds utilizes two or more ringlike coments arranged in a spaced concentric relationship for rotation about an axis and an expansion device interposed between the components for accommodating radial growth of the components resulting from flywheel operation. The expansion device engages both of the ringlike components, and the structure of the expansion device ensures that it maintains its engagement with the components. In addition to its expansion-accommodating capacity, the expansion device also maintains flywheel stiffness during flywheel operation.

  3. HIGH SPEED CAMERA

    Science.gov (United States)

    Rogers, B.T. Jr.; Davis, W.C.

    1957-12-17

    This patent relates to high speed cameras having resolution times of less than one-tenth microseconds suitable for filming distinct sequences of a very fast event such as an explosion. This camera consists of a rotating mirror with reflecting surfaces on both sides, a narrow mirror acting as a slit in a focal plane shutter, various other mirror and lens systems as well as an innage recording surface. The combination of the rotating mirrors and the slit mirror causes discrete, narrow, separate pictures to fall upon the film plane, thereby forming a moving image increment of the photographed event. Placing a reflecting surface on each side of the rotating mirror cancels the image velocity that one side of the rotating mirror would impart, so as a camera having this short a resolution time is thereby possible.

  4. Flooding in counter-current two-phase flow

    Energy Technology Data Exchange (ETDEWEB)

    Ragland, W.A.; Ganic, E.N.

    1982-01-01

    Flooding is a phenomenon which is best described as the transition from counter-current to co-current flow. Early notice was taken of this phenomenon in the chemical engineering industry. Flooding also plays an important role in the field of two-phase heat transfer since it is a limit for many systems involving counter-current flow. Practical applications of flooding limited processes include wickless thermosyphons and the emergency core cooling system (ECCS) of pressurized water nuclear reactors. The phenomenon of flooding also is involved in the behavior of nuclear reactor core materials during severe accident conditions where flooding is one of the mechanisms governing the motion of the molten fuel pin cladding.

  5. Counter-current membrane reactor for WGS process: Membrane design

    Energy Technology Data Exchange (ETDEWEB)

    Piemonte, Vincenzo; Favetta, Barbara [Department of Chemical Engineering Materials and Environment, University of Rome ' ' La Sapienza' ' , via Eudossiana 18, 00184 Rome (Italy); De Falco, Marcello [Faculty of Engineering, University Campus Bio-Medico of Rome, via Alvaro del Portillo 21, 00128 Rome (Italy); Basile, Angelo [CNR-ITM, c/o University of Calabria, Via Pietro Bucci, Cubo 17/C, 87030 Rende (CS) (Italy)

    2010-11-15

    Water gas shift (WGS) is a thermodynamically limited reaction which has to operate at low temperatures, reducing kinetics rate and increasing the amount of catalyst required to reach valuable CO conversions. It has been widely demonstrated that the integration of hydrogen selective membranes is a promising way to enhance WGS reactors performance: a Pd-based MR operated successfully overcoming the thermodynamic constraints of a traditional reactor thanks to the removal of hydrogen from reaction environment. In the first part of a MR, the H{sub 2} partial pressure starts from a minimum value since the reaction has not started. As a consequence, if the carrier gas in the permeation zone is sent in counter-current, which is the most efficient configuration, in the first reactor section the H{sub 2} partial pressure in reaction zone is low while in the permeation zone is high, potentially implying back permeation. This means a bad utilization of the first part of the membrane area and thus, a worsening of the MR performance with lower H{sub 2} recovery and lower CO conversion with respect to the case in which the whole selective surface is properly used. To avoid this problem different MR configurations were evaluated by a 1-D pseudo-homogeneous model, validated with WGS industrial data reported in scientific literature. It was demonstrated that the permeated H{sub 2} flow rate per membrane surface, i.e. the membrane flux, strongly improves if selective membrane is placed only in the second part of the reactor: in fact, if the membrane is placed at L{sub m}/L{sub tot} = 0.5, the membrane flux is 0.2 kmol/(m{sup 2}h) about, if it is placed along all reactor tube (L{sub m}/L{sub tot} = 1), flux is 0.05 kmol/(m{sup 2}h). The effect of the L/D reactor ratio and of the reactor wall temperature on the CO conversion were also assessed. (author)

  6. Counter-current chromatography of black tea infusions.

    Science.gov (United States)

    Wedzicha, B L; Lo, M F; Donovan, T J

    1990-05-04

    Counter-current chromatography using a multilayer coil planet centrifuge, with solvent system ethyl acetate-butanol-water, permits the separation of black tea infusions into fractions which include pure SII and a mixture of SI and SIa thearubigins. Good resolution of several components of the infusion may be achieved in elution times of 1 to 2 h. The appearance of chromatograms is altered on decaffeinating the infusion. The effect of stationary phase composition is considered. Resolution of the peaks improves with butanol content.

  7. Local heat transfer properties in co- and counter-current G-L-S magnetically stabilized fluidized beds

    Institute of Scientific and Technical Information of China (English)

    Jinli Zhang; Ming Zhang; Wei Li; Xiaofang Li; Xiangkun Meng; Baoning Zong

    2011-01-01

    Heat transfer coefficients were measured by immersed probes in co- and counter-current G-L-S magnetically stabilized fluidized beds (MSFBs) using air,water and nickel-alloy particles as the gas,liquid and solid phases. Influences of major factors,including magnetic field intensity,superficial gas and liquid velocities,liquid viscosity and surface tension,on heat-transfer properties were studied experimentally,indicating that both co- and counter-current G-L-S MSFB can provide relatively uniform radial distribution of heat transfer coefficients under appropriate operation conditions,thus controlling operation temperature for highly exothermic multi-phase reaction systems. Two correlations were provided to estimate accurately heat transfer properties in both co- and counter-current G-L-S MSFB systems,with an average error of less than 10%.

  8. High-speed AC motors

    Energy Technology Data Exchange (ETDEWEB)

    Jokinen, T.; Arkkio, A. [Helsinki University of Technology Laboratory of Electromechanics, Otaniemi (Finland)

    1997-12-31

    The paper deals with various types of highspeed electric motors, and their limiting powers. Standard machines with laminated rotors can be utilised if the speed is moderate. The solid rotor construction makes it possible to reach higher power and speed levels than those of laminated rotors. The development work on high-speed motors done at Helsinki University of Technology is presented, too. (orig.) 12 refs.

  9. High Speed Compressor Study

    Science.gov (United States)

    2011-12-21

    are listed below, and some of these are discussed at length later. o Heat capacity issues in low temperature regenerators o Pressure drop losses...carried out on a relatively old design of compressor, initially developed for use with a Stirling cycle domestic freezer12, and subsequently used in a...2003), pp 247-253. 3 Wang, X, Dai, W., et al, “Performance of a Stirling -Type Pulse Tube Cooler for High Efficiency Operation at 100Hz

  10. High speed preprocessing system

    Indian Academy of Sciences (India)

    M Sankar Kishore

    2000-10-01

    In systems employing tracking, the area of interest is recognized using a high resolution camera and is handed overto the low resolution receiver. The images seen by the low resolution receiver and by the operator through the high resolution camera are different in spatial resolution. In order to establish the correlation between these two images, the high-resolution camera image needsto be preprocessed and made similar to the low-resolution receiver image. This paper discusses the implementation of a suitable preprocessing technique, emphasis being given to develop a system both in hardware and software to reduce processing time. By applying different software/hardware techniques, the execution time has been brought down from a few seconds to a few milliseconds for a typical set of conditions. The hardware is designed around i486 processors and software is developed in PL/M. The system is tested to match the images obtained by two different sensors of the same scene. The hardware and software have been evaluated with different sets of images.

  11. High speed optical networks

    Science.gov (United States)

    Frankel, Michael Y.; Livas, Jeff

    2005-02-01

    This overview will discuss core network technology and cost trade-offs inherent in choosing between "analog" architectures with high optical transparency, and ones heavily dependent on frequent "digital" signal regeneration. The exact balance will be related to the specific technology choices in each area outlined above, as well as the network needs such as node geographic spread, physical connectivity patterns, and demand loading. Over the course of a decade, optical networks have evolved from simple single-channel SONET regenerator-based links to multi-span multi-channel optically amplified ultra-long haul systems, fueled by high demand for bandwidth at reduced cost. In general, the cost of a well-designed high capacity system is dominated by the number of optical to electrical (OE) and electrical to optical (EO) conversions required. As the reach and channel capacity of the transport systems continued to increase, it became necessary to improve the granularity of the demand connections by introducing (optical add/drop multiplexers) OADMs. Thus, if a node requires only small demand connectivity, most of the optical channels are expressed through without regeneration (OEO). The network costs are correspondingly reduced, partially balanced by the increased cost of the OADM nodes. Lately, the industry has been aggressively pursuing a natural extension of this philosophy towards all-optical "analog" core networks, with each demand touching electrical digital circuitry only at the in/egress nodes. This is expected to produce a substantial elimination of OEO costs, increase in network capacity, and a notionally simpler operation and service turn-up. At the same time, such optical "analog" network requires a large amount of complicated hardware and software for monitoring and manipulating high bit rate optical signals. New and more complex modulation formats that provide resiliency to both optical noise and nonlinear propagation effects are important for extended

  12. CFD studies on the phenomena around counter-current flow limitations of gas/liquid two-phase flow in a model of a PWR hot leg

    Energy Technology Data Exchange (ETDEWEB)

    Deendarlianto, E-mail: deendarlianto@ugm.ac.id [Helmholtz-Zentrum Dresden-Rossendorf e.V., Institute of Safety Research, P.O. Box 510 119, D-01314 Dresden (Germany); Department of Mechanical and Industrial Engineering, Faculty of Engineering, Gadjah Mada University, Jalan Grafika No. 2, Yogyakarta 55281 (Indonesia); Hoehne, Thomas; Lucas, Dirk; Vallee, Christophe [Helmholtz-Zentrum Dresden-Rossendorf e.V., Institute of Safety Research, P.O. Box 510 119, D-01314 Dresden (Germany); Zabala, Gustavo Adolfo Montoya [Department of Chemical Engineering, Simon Bolivar University, Valle of Sartenejas, Caracas 1080 (Venezuela, Bolivarian Republic of)

    2011-12-15

    Highlights: Black-Right-Pointing-Pointer We modelled CCFL in a PWR hot leg using Algebraic Interfacial Area Density model. Black-Right-Pointing-Pointer The model is able to distinguish the local flow morphologies. Black-Right-Pointing-Pointer Test fluids are air-water and steam-water. Black-Right-Pointing-Pointer Calculated CCFL and water level are in good agreement with experimental data. - Abstract: In order to improve the understanding of counter-current two-phase flow and to validate new physical models, CFD simulations of a 1/3rd scale model of the hot leg of a German Konvoi pressurized water reactor (PWR) with rectangular cross section were performed. Selected counter-current flow limitation (CCFL) experiments conducted at Helmholtz-Zentrum Dresden-Rossendorf (HZDR) were calculated with ANSYS CFX using the multi-fluid Euler-Euler modelling approach. The transient calculations were carried out using a gas/liquid inhomogeneous multiphase flow model coupled with a shear stress transport (SST) turbulence model. In the simulation, the drag law was approached by a newly developed correlation of the drag coefficient in the Algebraic Interfacial Area Density (AIAD) model. The model can distinguish the bubbles, droplets and the free surface using the local liquid phase volume fraction value. A comparison with the high-speed video observations shows a good qualitative agreement. The results indicate also a quantitative agreement between calculations and experimental data for the CCFL characteristics and the water level inside the hot leg channel.

  13. Two-phase flow experiments on Counter-Current Flow Limitation in a model of the hot leg of a pressurized water reactor (2015 test series)

    Energy Technology Data Exchange (ETDEWEB)

    Beyer, Matthias; Lucas, Dirk; Pietruske, Heiko; Szalinski, Lutz

    2016-12-15

    Counter-Current Flow Limitation (CCFL) is of importance for PWR safety analyses in several accident scenarios connected with loss of coolant. Basing on the experiences obtained during a first series of hot leg tests now new experiments on counter-current flow limitation were conducted in the TOPFLOW pressure vessel. The test series comprises air-water tests at 1 and 2 bar as well as steam-water tests at 10, 25 and 50 bar. During the experiments the flow structure was observed along the hot leg model using a high-speed camera and web-cams. In addition pressure was measured at several positions along the horizontal part and the water levels in the reactor-simulator and steam-generator-simulator tanks were determined. This report documents the experimental setup including the description of operational and special measuring techniques, the experimental procedure and the data obtained. From these data flooding curves were obtained basing on the Wallis parameter. The results show a slight shift of the curves in dependency of the pressure. In addition a slight decrease of the slope was found with increasing pressure. Additional investigations concern the effects of hysteresis and the frequencies of liquid slugs. The latter ones show a dependency on pressure and the mass flow rate of the injected water. The data are available for CFD-model development and validation.

  14. Performance evaluation of high speed compressors for high speed multipliers

    Directory of Open Access Journals (Sweden)

    Nirlakalla Ravi

    2011-01-01

    Full Text Available This paper describes high speed compressors for high speed parallel multipliers like Booth Multiplier, Wallace Tree Multiplier in Digital Signal Processing (DSP. This paper presents 4-3, 5-3, 6-3 and 7-3 compressors for high speed multiplication. These compressors reduce vertical critical path more rapidly than conventional compressors. A 5-3 conventional compressor can take four steps to reduce bits from 5 to 3, but the proposed 5-3 takes only 2 steps. These compressors are simulated with H-Spice at a temperature of 25°C at a supply voltage 2.0V using 90nm MOSIS technology. The Power, Delay, Power Delay Product (PDP and Energy Delay Product (EDP of the compressors are calculated to analyze the total propagation delay and energy consumption. All the compressors are designed with half adder and full Adders only.

  15. Elution-extrusion counter-current chromatography for the separation of two pairs of isomeric monoterpenes from Paeoniae Alba Radix.

    Science.gov (United States)

    Chu, Chu; Zhang, Shidi; Tong, Shengqiang; Li, Xingnuo; Li, Qingyong; Yan, Jizhong

    2015-09-01

    In this work, a simple and efficient protocol for the rapid separation of two pairs of isomeric monoterpenes from Paeoniae Alba Radix was developed by combining macroporous resin and elution-extrusion counter-current chromatography. The crude extract was firstly subjected to a D101 macroporous resin column eluted with water and a series of different concentrations of ethanol. Then, effluents of 30 and 95% ethanol were collected as sample 1 and sample 2 for further counter-current chromatography purification. Finally, a pair of isomers, 96 mg of compound 1 and 48 mg of compound 2 with purities of 91.1 and 96.2%, respectively, was isolated from 200 mg of sample 1. The other pair of isomers, 14 mg of compound 3 and 8 mg of compound 4 with purities of 93.6 and 88.9%, respectively, was isolated from 48 mg of sample 2. Their purities were analyzed by high-performance liquid chromatography, and their chemical structures were identified by mass spectrometry and (1) H NMR spectroscopy. Compared to a normal counter-current chromatography separation, the separation time and solvent consumption of elution-extrusion counter-current chromatography were reduced while the resolutions were still good. The established protocol is promising for the separation of natural products with great disparity of content in herbal medicines. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  16. Modelling counter-current chromatography: a chemical engineering perspective.

    Science.gov (United States)

    Kostanian, A E

    2002-10-11

    In conventional chromatography, a solute is usually viewed to be longitudinally transported only in the mobile phase, remaining longitudinally motionless in the stationary phase. In counter-current chromatography, both phases undergo intense mixing in the variable force field of a coil planet centrifuge and longitudinal dispersion of matter in the stationary phase is not to be excluded. To take into account longitudinal mixing in both phases, a cell model of chromatographic process is proposed in which the number of perfectly mixed cells n is determined by the rates of mixing in stationary (Ds) and mobile (Dm) phases by the equation n = LF/(2ADc)/(1 + Sf(lambda - 1)) with A = K(D)D(S)/Dm (F, L, Ac and KD are the mobile phase flow-rate, column length, column cross-section and distribution ratio, respectively). This equation has been derived by comparing the discontinuous cell model with continuous diffusion assuming equilibrium conditions. Parameter determination and their relationships are discussed.

  17. Separation and purification of five alkaloids from Aconitum duclouxii by counter-current chromatography.

    Science.gov (United States)

    Wang, Yarong; Cai, Shining; Chen, Yang; Deng, Liang; Zhou, Xumei; Liu, Jia; Xu, Xin; Xia, Qiang; Lin, Mao; Zhang, Jili; Huang, Weili; Wang, Wenjun; Xiang, Canhui; Cui, Guozhen; Du, Lianfeng; He, Huan; Qi, Baohui

    2015-07-01

    C19 -diterpenoid alkaloids are the main components of Aconitum duclouxii Levl. The process of separation and purification of these compounds in previous studies was tedious and time consuming, requiring multiple chromatographic steps, thus resulted in low recovery and high cost. In the present work, five C19 -diterpenoid alkaloids, namely, benzoylaconine (1), N-deethylaconitine (2), aconitine (3), deoxyaconitine (4), and ducloudine A (5), were efficiently prepared from A. duclouxii Levl (Aconitum L.) by ethyl acetate extraction followed with counter-current chromatography. In the process of separation, the critical conditions of counter-current chromatography were optimized. The two-phase solvent system composed of n-hexane/ethyl acetate/methanol/water/NH3 ·H2 O (25%) (1:1:1:1:0.1, v/v) was selected and 148.2 mg of 1, 24.1 mg of 2, 250.6 mg of 3, 73.9 mg of 4, and 31.4 mg of 5 were obtained from 1 g total Aconitum alkaloids extract, respectively, in a single run within 4 h. Their purities were found to be 98.4, 97.2, 98.2, 96.8, and 96.6%, respectively, by ultra-high performance liquid chromatography analysis. The presented separation and purification method was simple, fast, and efficient, and the obtained highly pure alkaloids are suitable for biochemical and toxicological investigation.

  18. High-speed photonics interconnects

    CERN Document Server

    Chrostowski, Lukas

    2013-01-01

    Dramatic increases in processing power have rapidly scaled on-chip aggregate bandwidths into the Tb/s range. This necessitates a corresponding increase in the amount of data communicated between chips, so as not to limit overall system performance. To meet the increasing demand for interchip communication bandwidth, researchers are investigating the use of high-speed optical interconnect architectures. Unlike their electrical counterparts, optical interconnects offer high bandwidth and negligible frequency-dependent loss, making possible per-channel data rates of more than 10 Gb/s. High-Speed

  19. Low sensitivity of counter-current immuno-electrophoresis for serodiagnosis of typhoid fever.

    Science.gov (United States)

    Sharma, M; Datta, U; Roy, P; Verma, S; Sehgal, S

    1997-12-01

    Counter-current immuno-electrophoresis was evaluated as a diagnostic test for the serodiagnosis of typhoid fever with somatic (O), flagellar (H) and capsular polysaccharide (Vi) antigens of Salmonella typhi on the sera of patients who were blood culture positive (confirmed typhoid cases) or had high Widal agglutination titres, > or = 320, (presumptive typhoid cases). Of the 37 sera from confirmed cases, 30% showed positivity with O antigen, 24% with H antigens and 51% with Vi antigen. In patients with a presumptive diagnosis, 45% were positive for O antibody, 27% for flagellar antibody and 52% for Vi antibody. When all three antigens were combined the reactivity to any of the antigens was found to be 59% in confirmed typhoid cases, 79% in presumptive typhoid cases and 93% in patients who were simultaneously positive by blood culture and Widal agglutination. However, none of the sera from 45 controls gave a positive precipitation reaction with any of the antigens. It is concluded that counter-current immuno-electrophoresis is a rapid test with low sensitivity and high specificity with Vi antigen, a panel of antigens being most effective, and is, therefore, recommended for rapid diagnosis of typhoid fever.

  20. High-speed pulse techniques

    CERN Document Server

    Coekin, J A

    1975-01-01

    High-Speed Pulse Techniques covers the many aspects of technique in digital electronics and encompass some of the more fundamental factors that apply to all digital systems. The book describes the nature of pulse signals and their deliberate or inadvertent processing in networks, transmission lines and transformers, and then examines the characteristics and transient performance of semiconductor devices and integrated circuits. Some of the problems associated with the assembly of these into viable systems operating at ultra high speed are also looked at. The book examines the transients and w

  1. Simultaneous separation of three isomeric sennosides from senna leaf (Cassia acutifolia) using counter-current chromatography.

    Science.gov (United States)

    Park, Sait Byul; Kim, Yeong Shik

    2015-10-01

    Senna leaf is widely consumed as tea to treat constipation or to aid in weight loss. Sennoside A, A1 , and B are dirheinanthrone glucosides that are abundant and the bioactive constituents in the plant. They are isomers that refer to the (R*R*), (S*S*), and (R*S*) forms of protons on C-10 and C-10' centers and it is difficult to refine them individually due to their structural similarities. The new separation method using counter-current chromatography successfully purified sennoside A, A1 , and B from senna leaf (Cassia acutifolia) while reversed-phase medium-pressure liquid chromatography yielded sennoside A only. n-Butanol/isopropanol/water (5:1:6, v/v/v) was selected as the solvent system for counter-current chromatography operation, and the partition coefficients were carefully determined by adding different concentrations of formic acid. High-resolution mass spectrometry and NMR spectroscopy were performed to verify the chemical properties of the compounds.

  2. The effects of surface tension on flooding in counter-current two-phase flow in an inclined tube

    Energy Technology Data Exchange (ETDEWEB)

    Deendarlianto [Department of Mechanical and Industrial Engineering, Faculty of Engineering, Gadjah Mada University, Jalan Grafika No.2 Yogyakarta 55281 (Indonesia); Forschungszentrum Dresden-Rossendorf e.V., Institute of Safety Research, P.O. Box 510 119, D-01314 Dresden (Germany); Ousaka, Akiharu [Department of Mechanical Engineering, The University of Tokushima, 2-1 Minami Josanjima, Tokushima 770-8506 (Japan); Indarto [Department of Mechanical and Industrial Engineering, Faculty of Engineering, Gadjah Mada University, Jalan Grafika No.2 Yogyakarta 55281 (Indonesia); Kariyasaki, Akira [Department of Chemical Engineering, Fukuoka University, 8-19-1, Jyonan-ku, Fukuoka 814-0180 (Japan); Lucas, Dirk; Vallee, Christophe [Forschungszentrum Dresden-Rossendorf e.V., Institute of Safety Research, P.O. Box 510 119, D-01314 Dresden (Germany); Vierow, Karen; Hogan, Kevin [Department of Nuclear Engineering Texas A and M University, 129 Zachry Engineering Center, 3133 TAMU College Station, TX 77843-3133 (United States)

    2010-10-15

    The purpose of the present study is to investigate the effects of surface tension on flooding phenomena in counter-current two-phase flow in an inclined tube. Previous studies by other researchers have shown that surface tension has a stabilizing effect on the falling liquid film under certain conditions and a destabilizing or unclear trend under other conditions. Experimental results are reported herein for air-water systems in which a surfactant has been added to vary the liquid surface tension without altering other liquid properties. The flooding section is a tube of 16 mm in inner diameter and 1.1 m length, inclined at 30-60 from horizontal. The flooding mechanisms were observed by using two high-speed video cameras and by measuring the time variation of liquid hold-up along the test tube. The results show that effects of surface tension are significant. The gas velocity needed to induce flooding is lower for a lower surface tension. There was no upward motion of the air-water interfacial waves upon flooding occurrence, even for lower a surface tension. Observations on the liquid film behavior after flooding occurred suggest that the entrainment of liquid droplets plays an important role in the upward transport of liquid. Finally, an empirical correlation for flooding velocities is proposed that includes functional dependencies on surface tension and tube inclination. (author)

  3. High-speed OTDM switching

    DEFF Research Database (Denmark)

    Jepsen, Kim Stokholm; Mikkelsen, Benny; Clausen, Anders

    1998-01-01

    Optical TDM (OTDM) continues to be of interest both for point-point transmission and as a networking technology for both LANs and long-distance fibre transmission. Recent research has demonstrated enabling techniques for OTDM networks at high speeds. In conclusion, OTDM is emerging as an attracti...

  4. Small Scale High Speed Turbomachinery

    Science.gov (United States)

    London, Adam P. (Inventor); Droppers, Lloyd J. (Inventor); Lehman, Matthew K. (Inventor); Mehra, Amitav (Inventor)

    2015-01-01

    A small scale, high speed turbomachine is described, as well as a process for manufacturing the turbomachine. The turbomachine is manufactured by diffusion bonding stacked sheets of metal foil, each of which has been pre-formed to correspond to a cross section of the turbomachine structure. The turbomachines include rotating elements as well as static structures. Using this process, turbomachines may be manufactured with rotating elements that have outer diameters of less than four inches in size, and/or blading heights of less than 0.1 inches. The rotating elements of the turbomachines are capable of rotating at speeds in excess of 150 feet per second. In addition, cooling features may be added internally to blading to facilitate cooling in high temperature operations.

  5. Preparative separation of high-purity cordycepin from Cordyceps militaris(L.) Link by high-speed countercurrent chromatography

    Science.gov (United States)

    Zhu, Licai; Liang, Yong; Lao, Deqiang; Zhang, Tianyou; Ito, Yoichiro

    2009-01-01

    A high-speed counter-current chromatography (HSCCC) technique in a preparative scale has been applied to separate and purify cordycepin from the extract of Cordyceps militaris(L.) Link by a one-step separation. A high efficiency of HSCCC separation was achieved on a two-phase solvent system of n-hexane–n-butanol–methanol–water (23:80:30:155, v/v/v/v) by eluting the lower mobile phase at a flow rate of 2 ml/min under a revolution speed of 850 rpm. HSCCC separation of 216.2 mg crude sample (contained cordycepin at 44.7% purity after 732 cation-exchange resin clean-up) yielded 64.8 mg cordycepin with purity of 98.9% and 91.7% recovery. Identification of the target compound was performed by UV, IR, MS, 1H NMR and 13C NMR. PMID:21643461

  6. Exploring of Chinese High-speed Railways

    Institute of Scientific and Technical Information of China (English)

    liuYoumei

    2004-01-01

    Based ion experiences of high-speed railways in foreign countries,the speed-raise situation of the Chinese railways,the research & development and test of high-speed transportation carries,as well as the prospective of high-speed railway in China are introduced.

  7. High-Speed TCP Testing

    Science.gov (United States)

    Brooks, David E.; Gassman, Holly; Beering, Dave R.; Welch, Arun; Hoder, Douglas J.; Ivancic, William D.

    1999-01-01

    Transmission Control Protocol (TCP) is the underlying protocol used within the Internet for reliable information transfer. As such, there is great interest to have all implementations of TCP efficiently interoperate. This is particularly important for links exhibiting long bandwidth-delay products. The tools exist to perform TCP analysis at low rates and low delays. However, for extremely high-rate and lone-delay links such as 622 Mbps over geosynchronous satellites, new tools and testing techniques are required. This paper describes the tools and techniques used to analyze and debug various TCP implementations over high-speed, long-delay links.

  8. Linear and nonlinear instability in vertical counter-current laminar gas-liquid flows

    CERN Document Server

    Schmidt, Patrick; Lucquiaud, Mathieu; Valluri, Prashant

    2015-01-01

    We consider the genesis and dynamics of interfacial instability in gas-liquid flows, using as a model the two-dimensional channel flow of a thin falling film sheared by counter-current gas. The methodology is linear stability theory (Orr-Sommerfeld analysis) together with direct numerical simulation of the two-phase flow in the case of nonlinear disturbances. We investigate the influence of three main flow parameters (density contrast between liquid and gas, film thickness, pressure drop applied to drive the gas stream) on the interfacial dynamics. Energy budget analyses based on the Orr-Sommerfeld theory reveal various coexisting unstable modes (interfacial, shear, internal) in the case of high density contrasts, which results in mode coalescence and mode competition, but only one dynamically relevant unstable internal mode for low density contrast. The same linear stability approach provides a quantitative prediction for the onset of (partial) liquid flow reversal in terms of the gas and liquid flow rates. ...

  9. Cutting tool materials for high speed machining

    Institute of Scientific and Technical Information of China (English)

    LIU Zhanqiang; AI Xing

    2005-01-01

    High speed machining (HSM) is one of the emerging cutting processes, which is machining at a speed significantlyhigher than the speed commonly in use on the shop floor. In the last twenty years, high speed machining has received great attentions as a technological solution for high productivity in manufacturing. This article reviews the developments of tool materials in high speed machining operations, and the properties, applications and prospective developments of tool materials in HSM are also presented.

  10. Flexible high-speed CODEC

    Science.gov (United States)

    Segallis, Greg P.; Wernlund, Jim V.; Corry, Glen

    1993-08-01

    This report is prepared by Harris Government Communication Systems Division for NASA Lewis Research Center under contract NAS3-25087. It is written in accordance with SOW section 4.0 (d) as detailed in section 2.6. The purpose of this document is to provide a summary of the program, performance results and analysis, and a technical assessment. The purpose of this program was to develop a flexible, high-speed CODEC that provides substantial coding gain while maintaining bandwidth efficiency for use in both continuous and bursted data environments for a variety of applications.

  11. Application of high-speed counter-current chromatography coupled with high performance liquid chromatography for the separation and purification of Quercetin-3-O-sambubioside from the leaves of Nelumbo nucifera

    Institute of Scientific and Technical Information of China (English)

    Shengguo DENG; Zeyuan DENG; Yawei FAN; Jing LI; Rong LIU; Dongmei XIONG

    2009-01-01

    @@ This research was funded by the Natural Science Foundation of Jiangxi Province (2006GY0066), the Research Project of Education Office of Jiangxi Province (20030058) and the Program for Yangtse Scholars and Innovative Research Team in University (IRT0540). Dr. Guiming Fu (Nanchang University, Nanchang, China) and Dr. Delong Zhou (Jiangxi Normal University, Nanchang, China) are greatly acknowledged for their help in structure analysis and identification of compounds.

  12. Efficient counter-current chromatographic isolation and structural identification of two new cinnamic acids from Echinacea purpurea.

    Science.gov (United States)

    Lu, Ying; Li, JiaYin; Li, MiLu; Hu, Xia; Tan, Jun; Liu, Zhong Hua

    2012-10-01

    Two new cinnamic acids, 2-O-caffeoyl-3-O-isoferuloyltartaric (3), and 2, 3-di-O-isoferuloyltartaric acid (5), along with three known caffeic acids, cichoric acid (1), 2-O-caffeoyl-3-O-feruloyltartaric acid (2) and 2-O-caffeoyl-3-O-p-coumaroyltartaric acid (4), have been successfully isolated and purified from Echinacea purpurea. In this study, we investigated an efficient method for the preparative isolation and purification of cinnamic acids from E. purpurea by high-speed counter-current chromatography (HSCCC). The separation was performed using a two-phase solvent composed of n-hexane-ethyl-acetate-methanol-0.5% aqueous acetic acid (1:3:1:4, v/v). The upper phase was used as the stationary phase and the lower phase as the mobile phase, with a flow rate of 1.6 mL/min. From 250 mg of crude extracts, 65.1 mg of 1, 8.3 mg of 2, 4.0 mg of 3, 4.5 mg of 4, and 4.3 mg of 5 were isolated in one-step, with purities of 98.5%, 97.7%, 94.6%, 94.3%, and 98.6%, respectively, as evaluated by HPLC-DAD. The chemical structures were identified by electro spray ionization mass spectrometry (ESI-MS) and one- and two-dimensional NMR spectra. HSCCC was very efficient for the separation and purification of the cinnamic acids from

  13. Towards high-speed scanning tunneling microscopy

    NARCIS (Netherlands)

    Tabak, Femke Chantal

    2013-01-01

    In this thesis, two routes towards high-speed scanning tunneling microscopy (STM) are described. The first possibility for high-speed scanning that is discussed is the use of MEMS (Micro-Electro Mechanical Systems) devices as high-speed add-ons in STM microscopes. The functionality of these devices

  14. High Speed Viterbi Decoder Architecture

    DEFF Research Database (Denmark)

    Paaske, Erik; Andersen, Jakob Dahl

    1998-01-01

    The fastest commercially available Viterbi decoders for the (171,133) standard rate 1/2 code operate with a decoding speed of 40-50 Mbit/s (net data rate). In this paper we present a suitable architecture for decoders operating with decoding speeds of 150-300 Mbit/s.......The fastest commercially available Viterbi decoders for the (171,133) standard rate 1/2 code operate with a decoding speed of 40-50 Mbit/s (net data rate). In this paper we present a suitable architecture for decoders operating with decoding speeds of 150-300 Mbit/s....

  15. Scale-up of counter-current chromatography: demonstration of predictable isocratic and quasi-continuous operating modes from the test tube to pilot/process scale.

    Science.gov (United States)

    Sutherland, Ian; Hewitson, Peter; Ignatova, Svetlana

    2009-12-11

    Predictable scale-up from test tube derived distribution ratios and analytical-scale sample loading optimisation is demonstrated using a model sample system of benzyl alcohol and p-cresol in a heptane:ethyl acetate:methanol:water phase system with the new 18 L Maxi counter-current chromatography centrifuge. The versatility of having a liquid stationary phase with its high loading capacity and flexible operating modes is demonstrated at two different scales by separating and concentrating target compounds using a mixture of caffeine, vanillin, naringenin and carvone using a quasi-continuous technique called intermittent counter-current extraction.

  16. Experimental high-speed network

    Science.gov (United States)

    McNeill, Kevin M.; Klein, William P.; Vercillo, Richard; Alsafadi, Yasser H.; Parra, Miguel V.; Dallas, William J.

    1993-09-01

    Many existing local area networking protocols currently applied in medical imaging were originally designed for relatively low-speed, low-volume networking. These protocols utilize small packet sizes appropriate for text based communication. Local area networks of this type typically provide raw bandwidth under 125 MHz. These older network technologies are not optimized for the low delay, high data traffic environment of a totally digital radiology department. Some current implementations use point-to-point links when greater bandwidth is required. However, the use of point-to-point communications for a total digital radiology department network presents many disadvantages. This paper describes work on an experimental multi-access local area network called XFT. The work includes the protocol specification, and the design and implementation of network interface hardware and software. The protocol specifies the Physical and Data Link layers (OSI layers 1 & 2) for a fiber-optic based token ring providing a raw bandwidth of 500 MHz. The protocol design and implementation of the XFT interface hardware includes many features to optimize image transfer and provide flexibility for additional future enhancements which include: a modular hardware design supporting easy portability to a variety of host system buses, a versatile message buffer design providing 16 MB of memory, and the capability to extend the raw bandwidth of the network to 3.0 GHz.

  17. Topsy-turvy: Turning the counter-current heat exchange of leatherback turtles upside down

    Science.gov (United States)

    Davenport, John; Jones, T. Todd; Work, Thierry M.; Balazs, George H.

    2015-01-01

    Counter-current heat exchangers associated with appendages of endotherms feature bundles of closely applied arteriovenous vessels. The accepted paradigm is that heat from warm arterial blood travelling into the appendage crosses into cool venous blood returning to the body. High core temperature is maintained, but the appendage functions at low temperature. Leatherback turtles have elevated core temperatures in cold seawater and arteriovenous plexuses at the roots of all four limbs. We demonstrate that plexuses of the hindlimbs are situated wholly within the hip musculature, and that, at the distal ends of the plexuses, most blood vessels supply or drain the hip muscles, with little distal vascular supply to, or drainage from the limb blades. Venous blood entering a plexus will therefore be drained from active locomotory muscles that are overlaid by thick blubber when the adults are foraging in cold temperate waters. Plexuses maintain high limb muscle temperature and avoid excessive loss of heat to the core, the reverse of the accepted paradigm. Plexuses protect the core from overheating generated by muscular thermogenesis during nesting.

  18. Purification of Active Myrosinase from Plants by Aqueous Two-Phase Counter-Current Chromatography

    Science.gov (United States)

    Wade, Kristina L.; Ito, Yoichiro; Ramarathnam, Aarthi; Holtzclaw, W. David; Fahey, Jed W.

    2014-01-01

    Introduction Myrosinase (thioglucoside glucohydrolase; E.C. 3.2.1.147), is a plant enzyme of increasing interest and importance to the biomedical community. Myrosinase catalyses the formation of isothiocyanates such as sulforaphane (frombroccoli) and 4-(α-l-rhamnopyranosyloxy)benzyl isothiocyanate (from moringa), which are potent inducers of the cytoprotective phase-2 response in humans, by hydrolysis of their abundant glucosinolate (β-thioglucoside N-hydroxysulphate) precursors. Objective To develop an aqueous two-phase counter-current chromatography (CCC) system for the rapid, three-step purification of catalytically active myrosinase. Methods A high-concentration potassium phosphate and polyethylene glycol biphasic aqueous two-phase system (ATPS) is used with a newly developed CCC configuration that utilises spiral-wound, flat-twisted tubing (with an ovoid cross-section). Results Making the initial crude plant extract directly in the ATPS and injecting only the lower phase permitted highly selective partitioning of the myrosinase complex before a short chromatography on a spiral disk CCC. Optimum phase retention and separation of myrosinase from other plant proteins afforded a 60-fold purification. Conclusion Catalytically active myrosinase is purified from 3-day broccoli sprouts, 7-day daikon sprouts, mustard seeds and the leaves of field-grown moringa trees, in a CCC system that is predictably scalable. PMID:25130502

  19. Steady-state and non-steady state operation of counter-current chromatography devices.

    Science.gov (United States)

    Kostanyan, Artak E; Ignatova, Svetlana N; Sutherland, Ian A; Hewitson, Peter; Zakhodjaeva, Yulya A; Erastov, Andrey A

    2013-11-01

    Different variants of separation processes based on steady-state (continuous sample loading) and non-steady state (batch) operating modes of CCC columns have been analyzed and compared. The analysis is carried out on the basis of the modified equilibrium cell model, which takes into account both mechanisms of band broadening - interphase mass transfer and axial mixing. A full theoretical treatment of the intermittent counter-current chromatography with short sample loading time is performed. Analytical expressions are presented allowing the simulation of the intermittent counter-current chromatography separations for various experimental conditions. Chromatographic and extraction separations have been compared and advantages and disadvantages of the two methods have been evaluated. Further technical development of the CCC machines to implement counter-current extraction separations is considered.

  20. New 18-l process-scale counter-current chromatography centrifuge.

    Science.gov (United States)

    Sutherland, Ian; Hewitson, Peter; Ignatova, Svetlana

    2009-05-08

    A new Dynamic Extractions Maxi-counter-current chromatography (CCC) centrifuge with a column volume of 18-l has been installed in the Advanced Bioprocessing Centre at Brunel. This instrument has four times the capacity of the 4.6-l Maxi-CCC centrifuge which has been operating robustly for 3 years. Tests using the model sample system benzyl alcohol and p-cresol with a heptane:ethyl acetate:methanol:water (HEMWat) phase system (1.4:0.1:0.5:1.0) show that resolution is almost double with this new high capacity device. Commissioning tests with a mixture of caffeine, K(D)=0.21; ferulic acid, K(D)=0.82; umbelliferone, K(D)=1.2 and vanillin, K(D)=1.49 using a HEMWat phase system of 1:1.5:1:1.5 on the 9-l column show that resolutions equivalent to analytical instruments will be possible using the full 18-l capacity. They also show that predictable scale-up from simple test tube tests is feasible with knowledge of the stationary phase retention for the planned process scale run.

  1. 高速逆流色谱分离制备紫锥菊中的菊苣酸%Preparation and Separation of Cichoric Acid From Echinacea Purpurea by High Speed Counter-current Chromatography

    Institute of Scientific and Technical Information of China (English)

    刘建华; 赵善仓; 王晓; 耿岩玲; 李福伟

    2008-01-01

    建立了高速逆流色谱分离制备紫锥菊有效成分菊苣酸的新方法.溶剂系统为V(正己烷)∶ V(乙酸乙酯)∶ V(甲醇)∶ V(0.5%乙酸)=1∶ 4∶ 2∶ 5.5,上相为固定相,下相为流动相.从200 mg紫锥菊粗提物一次分离得到纯度为96.8%的菊苣酸33.6 mg,并用LC-MS-MS鉴定了化学结构.

  2. Preparative Separation of Gentiopicrin from Gentiana scabra Bunge by High Speed Counter Current Chromatography%HSCCC法分离制备龙胆有效成分龙胆苦苷

    Institute of Scientific and Technical Information of China (English)

    王艳艳; 王英平; 刘继永; 焉石; 孙成贺; 许世泉

    2007-01-01

    目的:采用高速逆流色谱技术(HSCCC)从龙胆中分离制备高纯度龙胆苦苷.方法:利用制备型高速逆流色谱仪,以氯仿-甲醇-正丁醇-水(5:4:2:4)为溶剂系统对龙胆甲醇粗提物进行分离,上相为固定相,下相为流动相,转速为820 r/min,流速为2.0 ml/min.结果:所得龙胆苦苷经HPLC分析,纯度达到96.68%(峰面积百分比).结论:此研究为其他环烯醚萜苷的分离纯化提供了依据.

  3. 高速逆流色谱分离小茴香中香气成分研究%Separation of Flavors from Foeniculum Vulgare by High-speed Counter-current Chromatography

    Institute of Scientific and Technical Information of China (English)

    肖阳; 谢建春; 马琳贺; 马洁峰

    2007-01-01

    以小茴香为原料,采用水中直接蒸馏的方法提取小茴香精油.采用V(正己烷):V(乙酸乙酯):V(甲醇):V(水)=5:2:5:2为溶剂体系,上相为固定相,下相做流动相,高速逆流色谱(HSCCC)转速854.6 r/min,流动相流速2 mL/min,UV检测波长254 nm,在保留时间95~100 min,分离出茴香醛,茴香脑,茴香酮一组化合物,结构经GC-MS确认.

  4. Preparative Isolation of Hypericin from St. John's Wort by High- Speed Counter- Current Chromatography%高速逆流色谱快速分离制备贯叶连翘中的金丝桃素

    Institute of Scientific and Technical Information of China (English)

    陈峰阳; 李晓誉; 叶益萍; 徐世芳

    2009-01-01

    目的:建立从贯叶连翘中快速分离制备高纯度金丝桃素的方法.方法:市售贯叶连翘提取物经聚酰胺树脂预处理后直接进行高速逆流色谱分离纯化,以正己烷-乙酸乙酯-甲醇-水(3:5:3:5)为溶剂系统,所得产物化学结构由1H NMR和13C NMR鉴定,纯度经高效液相色谱外标法检测.结果:在此条件下,经一步分离从300 mg预处理粗提物中可得到13.6mg纯度为95%的金丝桃素.结论:该法简便、快速、所得产物纯度高,适合于高纯度金丝桃素的制备.

  5. High speed imaging - An important industrial tool

    Science.gov (United States)

    Moore, Alton; Pinelli, Thomas E.

    1986-01-01

    High-speed photography, which is a rapid sequence of photographs that allow an event to be analyzed through the stoppage of motion or the production of slow-motion effects, is examined. In high-speed photography 16, 35, and 70 mm film and framing rates between 64-12,000 frames per second are utilized to measure such factors as angles, velocities, failure points, and deflections. The use of dual timing lamps in high-speed photography and the difficulties encountered with exposure and programming the camera and event are discussed. The application of video cameras to the recording of high-speed events is described.

  6. Comparison of High Speed Congestion Control Protocols

    Directory of Open Access Journals (Sweden)

    Jawhar Ben Abed

    2012-10-01

    Full Text Available Congestion control limits the quantity of information input at a rate less important than that of thetransmission one to ensure good performance as well as protect against overload and blocking of thenetwork. Researchers have done a great deal of work on improving congestion control protocols,especially on high speed networks.In this paper, we will be studying the congestion control alongside low and high speed congestion controlprotocols. We will be also simulating, evaluating, and comparing eight of high speed congestion controlprotocols : Bic TCP, Cubic TCP, Hamilton TCP, HighSpeed TCP, Illinois TCP, Scalable TCP,Compound TCP and YeAH TCP, with multiple flows.

  7. High Speed On-Wafer Characterization Laboratory

    Data.gov (United States)

    Federal Laboratory Consortium — At the High Speed On-Wafer Characterization Laboratory, researchers characterize and model devices operating at terahertz (THz) and millimeter-wave frequencies. The...

  8. High Speed On-Wafer Characterization Laboratory

    Data.gov (United States)

    Federal Laboratory Consortium — At the High Speed On-Wafer Characterization Laboratory, researchers characterize and model devices operating at terahertz (THz) and millimeter-wave frequencies. The...

  9. Fractionation of wheat gliadins by counter-current distribution using an organic two-phase system.

    Science.gov (United States)

    Truust, H; Johansson, G

    1998-06-26

    A liquid liquid two-phase system based on N,N-dimethylformamide and the two polymers, poly(ethyleneglycol) and Ficoll, useful for partitioning of hydrophobic proteins, has been developed. The system has been applied to a counter-current distribution process in 56 steps for analysing the heterogeneity of proteins extracted with N,N-dimethylformamide from wheat flour. The counter-current distribution patterns of proteins, extracted from eight kinds of wheat, have been analysed. The minimum number of hypothetical proteins necessary to describe the patterns was found to be seven. The relative amount of these hypothetical components varied among the wheats.

  10. Axillary artery counter-current aortography in the newborn with aortic arch obstruction

    Energy Technology Data Exchange (ETDEWEB)

    Lau, K.C.; Lo, R.N.S.; Leung, M.P.

    1989-08-01

    13 newborn infants with aortic coarctation were evaluated by counter-current aortographic technique. The right radial or brachial artery approach (2 cases in each group) did not give successful aortic arch imaging while the right axiallary artery approach resulted in adequate imaging in each of 9 cases investigated. In 2, the axillary artery was transiently weakened but returned to normal within 24 hours. No other complications were encountered. Axillary artery counter-current aortography is a safe and relatively non-invasive procedure which can be used to image the aortic arch in the newborn babies when other non-invasive diagnosis of aortic arch obstruction is tentative. (orig.).

  11. High-Speed Ring Bus

    Science.gov (United States)

    Wysocky, Terry; Kopf, Edward, Jr.; Katanyoutananti, Sunant; Steiner, Carl; Balian, Harry

    2010-01-01

    The high-speed ring bus at the Jet Propulsion Laboratory (JPL) allows for future growth trends in spacecraft seen with future scientific missions. This innovation constitutes an enhancement of the 1393 bus as documented in the Institute of Electrical and Electronics Engineers (IEEE) 1393-1999 standard for a spaceborne fiber-optic data bus. It allows for high-bandwidth and time synchronization of all nodes on the ring. The JPL ring bus allows for interconnection of active units with autonomous operation and increased fault handling at high bandwidths. It minimizes the flight software interface with an intelligent physical layer design that has few states to manage as well as simplified testability. The design will soon be documented in the AS-1393 standard (Serial Hi-Rel Ring Network for Aerospace Applications). The framework is designed for "Class A" spacecraft operation and provides redundant data paths. It is based on "fault containment regions" and "redundant functional regions (RFR)" and has a method for allocating cables that completely supports the redundancy in spacecraft design, allowing for a complete RFR to fail. This design reduces the mass of the bus by incorporating both the Control Unit and the Data Unit in the same hardware. The standard uses ATM (asynchronous transfer mode) packets, standardized by ITU-T, ANSI, ETSI, and the ATM Forum. The IEEE-1393 standard uses the UNI form of the packet and provides no protection for the data portion of the cell. The JPL design adds optional formatting to this data portion. This design extends fault protection beyond that of the interconnect. This includes adding protection to the data portion that is contained within the Bus Interface Units (BIUs) and by adding to the signal interface between the Data Host and the JPL 1393 Ring Bus. Data transfer on the ring bus does not involve a master or initiator. Following bus protocol, any BIU may transmit data on the ring whenever it has data received from its host. There

  12. Reducing Heating In High-Speed Cinematography

    Science.gov (United States)

    Slater, Howard A.

    1989-01-01

    Infrared-absorbing and infrared-reflecting glass filters simple and effective means for reducing rise in temperature during high-speed motion-picture photography. "Hot-mirror" and "cold-mirror" configurations, employed in projection of images, helps prevent excessive heating of scenes by powerful lamps used in high-speed photography.

  13. Hydrodynamic behaviour of a gas—solid counter-current packed column at trickle flow

    NARCIS (Netherlands)

    Roes, A.W.M.; Swaaij, van W.P.M.

    1979-01-01

    Trickle flow of a more or less fluidized catalyst through a packed column is a promising new gas—solid counter-current operation. The hydrodynamic, behaviour of such a column, filled with dumped PALL rings, has been investigated, while some results have been obtained with RASCHIG rings and cylindric

  14. Experimental Characterisation of the Interfacial Structure during Counter-Current Flow Limitation in a Model of the Hot Leg of a PWR

    Directory of Open Access Journals (Sweden)

    Christophe Vallée

    2012-01-01

    Full Text Available In order to investigate the two-phase flow behaviour during counter-current flow limitation in the hot leg of a pressurised water reactor, dedicated experiments were performed in a scaled down model of Kobe University. The experiments were performed with air and water at atmospheric pressure and room temperature. At high flow rates, CCFL occurs and the discharge of water to the reactor pressure vessel simulator is limited by the formation of slugs carrying liquid back to the steam generator. The structure of the interface was observed from the side of the channel test section using a high-speed video camera. An algorithm was developed to recognise the stratified interface in the camera frames after background subtraction. This method allows extracting the water level at any position in the image as well as performing further statistical treatments. The evolution of the interfacial structure along the horizontal part of the hot leg is shown by the visualisation of the probability distribution of the water level and analysed in function of the liquid and gas flow rates. The data achieved are useful for the analysis of the flow conditions as well as for the validation of modelling approaches like computational fluid dynamics.

  15. An investigation of counter-current flow in porous media with history-dependent modeling

    Science.gov (United States)

    Li, G.; Grader, A. S.; Halleck, P. H.; Karpyn, Z. T.

    2003-04-01

    Counter-current fluid flow occurs in many reservoir processes. It is important to understand and model these processes in order to operate them effectively. Both drainage and imbibition processes exist simultaneously when counter-current flow occurs. It has thus proven difficult to model this type of flow, especially when fluid banks form. Previously, counter-current flow experiments have been done in glass bead packs and the spatial and temporal saturation distributions obtained with X-ray computed tomography (CT). In the current paper, a new saturation-history-dependent approach has been developed to simulate the experiments. Hysteresis in both capillary pressure and relative permeabilities is considered during the process of matching the simulation results to experimental data. Capillary pressure and relative permeabilities are extracted with the aid of a deterministic reservoir simulator. During the history matching process, a family of curves (called scanning curves) is constructed connecting the two branches of the capillary hystersis loop. Each grid block of the sample is assigned a different scanning curve according to its saturation history. Simulation of the experiments reproduced two-dimensional saturation distributions over time with good accuracy. Similar results could not be obtained with traditional simulation using only one capillary pressure curve. History-dependent modeling successfully predicted cross-diameter counter-current flow in a cylindrical geometry. The parameters used in the single capillary pressure method are the average of the parameters used in the history-dependent method. Total effective mobility controls the flow process, being smaller in counter-current flow than in co-current flow. Experiments documented in the literature that exhibited formation of fluid banks were also successfully simulated. We anticipate that application of this method will improve the prediction of full-scale fluid flow processes such as ground water

  16. Active control system for high speed windmills

    Science.gov (United States)

    Avery, D.E.

    1988-01-12

    A pump stroke is matched to the operating speed of a high speed windmill. The windmill drives a hydraulic pump for a control. Changes in speed of a wind driven shaft open supply and exhaust valves to opposite ends of a hydraulic actuator to lengthen and shorten an oscillating arm thereby lengthening and shortening the stroke of an output pump. Diminishing wind to a stall speed causes the valves to operate the hydraulic cylinder to shorten the oscillating arm to zero. A pressure accumulator in the hydraulic system provides the force necessary to supply the hydraulic fluid under pressure to drive the actuator into and out of the zero position in response to the windmill shaft speed approaching and exceeding windmill stall speed. 4 figs.

  17. Preparative enantioseparation of propafenone by counter-current chromatography using di-n-butyl L-tartrate combined with boric acid as the chiral selector.

    Science.gov (United States)

    Tong, Shengqiang; Shen, Mangmang; Zheng, Ye; Chu, Chu; Li, Xing-Nuo; Yan, Jizhong

    2013-09-01

    This paper extends the research of the utilization of borate coordination complexes in chiral separation by counter-current chromatography (CCC). Racemic propafenone was successfully enantioseparated by CCC with di-n-butyl l-tartrate combined with boric acid as the chiral selector. The two-phase solvent system was composed of chloroform/ 0.05 mol/L acetate buffer pH 3.4 containing 0.10 mol/L boric acid (1:1, v/v), in which 0.10 mol/L di-n-butyl l-tartrate was added in the organic phase. The influence of factors in the enantioseparation of propafenone were investigated and optimized. A total of 92 mg of racemic propafenone was completely enantioseparated using high-speed CCC in a single run, yielding 40-42 mg of (R)- and (S)-propafenone enantiomers with an HPLC purity over 90-95%. The recovery for propafenone enantiomers from fractions of CCC was in the range of 85-90%. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  18. ERROR CORRECTION IN HIGH SPEED ARITHMETIC,

    Science.gov (United States)

    The errors due to a faulty high speed multiplier are shown to be iterative in nature. These errors are analyzed in various aspects. The arithmetic coding technique is suggested for the improvement of high speed multiplier reliability. Through a number theoretic investigation, a large class of arithmetic codes for single iterative error correction are developed. The codes are shown to have near-optimal rates and to render a simple decoding method. The implementation of these codes seems highly practical. (Author)

  19. Novel design for centrifugal counter-current chromatography: VI. Ellipsoid column.

    Science.gov (United States)

    Gu, Dongyu; Yang, Yi; Xin, Xuelei; Aisa, Haji Akber; Ito, Yoichiro

    2015-01-01

    A novel ellipsoid column was designed for centrifugal counter-current chromatography. Performance of the ellipsoid column with a capacity of 3.4 mL was examined with three different solvent systems composed of 1-butanol-acetic acid-water (4:1:5, v/v) (BAW), hexane-ethyl acetate-methanol-0.1 M HCl (1:1:1:1, v/v) (HEMH), and 12.5% (w/w) PEG1000 and 12.5% (w/w) dibasic potassium phosphate in water (PEG-DPP) each with suitable test samples. In dipeptide separation with BAW system, both stationary phase retention (Sf) and peak resolution (Rs) of the ellipsoid column were much higher at 0° column angle (column axis parallel to the centrifugal force) than at 90° column angle (column axis perpendicular to the centrifugal force), where elution with the lower phase at a low flow rate produced the best separation yielding Rs at 2.02 with 27.8% Sf at a flow rate of 0.07 ml/min. In the DNP-amino acid separation with HEMW system, the best results were obtained at a flow rate of 0.05 ml/min with 31.6% Sf yielding high Rs values at 2.16 between DNP-DL-glu and DNP-β-ala peaks and 1.81 between DNP-β-ala and DNP-L-ala peaks. In protein separation with PEG-DPP system, lysozyme and myolobin were resolved at Rs of 1.08 at a flow rate of 0.03 ml/min with 38.9% Sf. Most of those Rs values exceed those obtained from the figure-8 column under similar experimental conditions previously reported.

  20. Damping Bearings In High-Speed Turbomachines

    Science.gov (United States)

    Von Pragenau, George L.

    1994-01-01

    Paper presents comparison of damping bearings with traditional ball, roller, and hydrostatic bearings in high-speed cryogenic turbopumps. Concept of damping bearings described in "Damping Seals and Bearings for a Turbomachine" (MFS-28345).

  1. On China's High-Speed Railway Technology

    Institute of Scientific and Technical Information of China (English)

    You-tong FANG

    2011-01-01

    Energy and environmental issues have become increasingly prominent in matters of transportation.Compared with road,air,and sea transportation,railway transportation has the advantages of a large transmission capacity,with rapid,safe,and on-time travel,requiring less land resources,with lower energy consumption,less environmental pollution,and the capacity to operate under most weather conditions.In particular,high-speed railway technology has been growing rapidly.Since the world's first high-speed railway was built in Japan in 1964,more than ten countries and regions have developed high-speed railways,operating over a total of more than 10000 km.High-speed railways not only provide the public with a new type of rapid,convenient,safe,and comfortable travel,but also greatly boost the socio-economic development of the country.

  2. Flat belt continuously variable high speed drive

    Energy Technology Data Exchange (ETDEWEB)

    Kumm, E.L.

    1992-02-01

    A study was undertaken at Kumm Industries funded by DOE in the NBS/DOE Energy-Related Inventions Program starting in August 1990 to design, construct and test a novel very high speed flat belt drive. The test arrangement as shown in Figure 1 consists of a multiple belt-pulley configuration that transmits power from a low speed (2000--4000 RPM) input to a small pulley turbine'' (27,000 to 55,000 RPM) and then to the low speed output variable radius pulley (2000--5000 RPM) via a special self-active tensioner. Transmitting 25 HP to and from the turbine'' corresponds to obtaining 50 HP in one direction only in a possible turbo compounded engine application. The high speed of the turbine'' belts, i.e. 100 meters/sec. at 55,000 RPM, while transferring substantial power is a new much higher operating regime for belts. The study showed that the available belts gave overall test rig efficiencies somewhat above 80% for the higher speeds (50,000 RPM) and higher powers (corresponding to above 90% in the turbocompound application) and a significantly better efficiencies at slightly lower speeds. The tests revealed a number of improved approaches in the design of such high speed drives. It appears that there is considerable possibility for further improvement and application of such equipment.

  3. Scaling of Counter-Current Imbibition Process in Low-Permeability Porous Media, TR-121

    Energy Technology Data Exchange (ETDEWEB)

    Kvoscek, A.R.; Zhou, D.; Jia, L.; Kamath, J.

    2001-01-17

    This project presents the recent work on imaging imbibition in low permeability porous media (diatomite) with X-ray completed tomography. The viscosity ratio between nonwetting and wetting fluids is varied over several orders of magnitude yielding different levels of imbibition performance. Also performed is mathematical analysis of counter-current imbibition processes and development of a modified scaling group incorporating the mobility ratio. This modified group is physically based and appears to improve scaling accuracy of countercurrent imbibition significantly.

  4. Counter-current carbon dioxide extraction of fat from soy skim

    Science.gov (United States)

    This research aims to investigate the use of counter-current carbon dioxide extraction method as a means to reduce residual fat in soy skim after the enzyme-assisted aqueous extraction of soybeans. Extractions with liquid CO2 at 25°C and 10.34 MPa and supercritical CO2 at 50°C and 25.16 MPa are comp...

  5. Design of a High Speed Adder

    OpenAIRE

    Aritra Mitra; Amit Bakshi; Bhavesh Sharma; Nilesh Didwania

    2015-01-01

    In this paper we have compared different addition algorithms such as Ripple Carry Adder, Carry Save Adder, Carry Select Adder, Carry Look Ahead Adder & Kogge Stone Adder for different performance parameters i.e. Area Utilization, Speed of operation and Power Consumption. A high speed Adder is then designed by merging Kogge Stone & Carry Select Algorithms. The circuits have been designed using Verilog HDL & Synthesize using TSMC 180 nm standard cell. The performance parameters are ...

  6. Compressibility, turbulence and high speed flow

    CERN Document Server

    Gatski, Thomas B

    2013-01-01

    Compressibility, Turbulence and High Speed Flow introduces the reader to the field of compressible turbulence and compressible turbulent flows across a broad speed range, through a unique complimentary treatment of both the theoretical foundations and the measurement and analysis tools currently used. The book provides the reader with the necessary background and current trends in the theoretical and experimental aspects of compressible turbulent flows and compressible turbulence. Detailed derivations of the pertinent equations describing the motion of such turbulent flows is provided and

  7. Linear and nonlinear instability in vertical counter-current laminar gas-liquid flows

    Science.gov (United States)

    Schmidt, Patrick; Ó Náraigh, Lennon; Lucquiaud, Mathieu; Valluri, Prashant

    2016-04-01

    We consider the genesis and dynamics of interfacial instability in vertical gas-liquid flows, using as a model the two-dimensional channel flow of a thin falling film sheared by counter-current gas. The methodology is linear stability theory (Orr-Sommerfeld analysis) together with direct numerical simulation of the two-phase flow in the case of nonlinear disturbances. We investigate the influence of two main flow parameters on the interfacial dynamics, namely the film thickness and pressure drop applied to drive the gas stream. To make contact with existing studies in the literature, the effect of various density contrasts is also examined. Energy budget analyses based on the Orr-Sommerfeld theory reveal various coexisting unstable modes (interfacial, shear, internal) in the case of high density contrasts, which results in mode coalescence and mode competition, but only one dynamically relevant unstable interfacial mode for low density contrast. A study of absolute and convective instability for low density contrast shows that the system is absolutely unstable for all but two narrow regions of the investigated parameter space. Direct numerical simulations of the same system (low density contrast) show that linear theory holds up remarkably well upon the onset of large-amplitude waves as well as the existence of weakly nonlinear waves. For high density contrasts, corresponding more closely to an air-water-type system, linear stability theory is also successful at determining the most-dominant features in the interfacial wave dynamics at early-to-intermediate times. Nevertheless, the short waves selected by the linear theory undergo secondary instability and the wave train is no longer regular but rather exhibits chaotic motion. The same linear stability theory predicts when the direction of travel of the waves changes — from downwards to upwards. We outline the practical implications of this change in terms of loading and flooding. The change in direction of the

  8. VLSI Circuits for High Speed Data Conversion

    Science.gov (United States)

    1994-05-16

    Meeting, pp. 289-292, Sept. 199 1. [4] Behzad Razavi , "High-Speed, Nigh-Resolution Analog-to-Digital Conversion in VLSI Technologies, Ph.D. Thesis... Behzad Razavi and Bruce A. Wooley, "Design Techniques for High-Speed, High- Resolution Comparators," IEEE J. Solid-State Circuits, vol. 27, pp. 1916-192...Dec. 1992. [8] Behzad Razavi and Bruce A. Wooley, "A 12-Bkt 5-MSamplesoc Two-Step CMOS A/D Converter," IEEE J. Solid-State Circuits, vol. 27, pp

  9. Enantioseparation of (DL)-tryptophan by spiral tube assembly counter-current chromatography and evaluation of mass transfer rate for enantiomers.

    Science.gov (United States)

    Tong, Shengqiang; Ito, Yoichiro; Ma, Ying

    2014-12-29

    Spiral tube assembly counter-current chromatography was successfully applied in enantioseparation of dl-tryptophan using bovine serum albumin as chiral selector. An improved biphasic aqueous-aqueous solvent system 12.0% (w/w) polyethyleneglycol 8000-9.0% (w/w) dibasic potassium phosphate-0.1% ammonia-78.9% water was used as the solvent system for counter-current chromatography, in which bovine serum albumin was predominantly distributed in the lower phase of the two-phase aqueous system. The aqueous-aqueous solvent system gave a very high enantioselectivity for d- and l-tryptophan at α=2.605 along with distribution ratio DD=1.200 and DL=0.461. High peak resolution was obtained for enantioseparation of 2.0mg of dl-tryptophan by spiral tube assembly counter-current chromatography under room temperature. It was found that 0.1% ammonia added in the aqueous-aqueous solvent system greatly improved the enantioseparations. An unusual extremely broad peak for l-tryptophan was observed during enantioseparations. In order to give an explanation, mass transfer rates of d- and l-enantiomers through the interface between the two phases were measured. It was found that l-tryptophan showed lower mass transfer rate than d-tryptophan. Further discussions were proposed for possible reasons for mass transfer rate difference between the enantiomers.

  10. Aerodynamics of High-Speed Trains

    Science.gov (United States)

    Schetz, Joseph A.

    This review highlights the differences between the aerodynamics of high-speed trains and other types of transportation vehicles. The emphasis is on modern, high-speed trains, including magnetic levitation (Maglev) trains. Some of the key differences are derived from the fact that trains operate near the ground or a track, have much greater length-to-diameter ratios than other vehicles, pass close to each other and to trackside structures, are more subject to crosswinds, and operate in tunnels with entry and exit events. The coverage includes experimental techniques and results and analytical and numerical methods, concentrating on the most recent information available.

  11. DAC 22 High Speed Civil Transport Model

    Science.gov (United States)

    1992-01-01

    Between tests, NASA research engineer Dave Hahne inspects a tenth-scale model of a supersonic transport model in the 30- by 60-Foot Tunnel at NASA Langley Research Center, Hampton, Virginia. The model is being used in support of NASA's High-Speed Research (HSR) program. Langley researchers are applying advance aerodynamic design methods to develop a wing leading-edge flap system which significantly improves low-speed fuel efficiency and reduces noise generated during takeoff operation. Langley is NASA's lead center for the agency's HSR program, aimed at developing technology to help U.S. industry compete in the rapidly expanding trans-oceanic transport market. A U.S. high-speed civil transport is expected to fly in about the year 2010. As envisioned, it would fly 300 passengers across the Pacific in about four hours at Mach 2.4 (approximately 1,600 mph/1950 kph) for a modest increase over business class fares.

  12. A high speed digital noise generator

    Science.gov (United States)

    Obrien, J.; Gaffney, B.; Liu, B.

    In testing of digital signal processing hardware, a high speed pseudo-random noise generator is often required to simulate an input noise source to the hardware. This allows the hardware to be exercised in a manner analogous to actual operating conditions. In certain radar and communication environments, a noise generator operating at speeds in excess of 60 MHz may be required. In this paper, a method of generating high speed pseudo-random numbers from an arbitrarily specified distribution (Gaussian, Log-Normal, etc.) using a transformation from a uniform noise source is described. A noise generator operating at 80 MHz has been constructed. Different distributions can be readily obtained by simply changing the ROM set. The hardware and test results will be described. Using this approach, the generation of pseudo-random sequences with arbitrary distributions at word rates in excess of 200 MHz can be readily achieved.

  13. High Speed and Slow Motion: The Technology of Modern High Speed Cameras

    Science.gov (United States)

    Vollmer, Michael; Mollmann, Klaus-Peter

    2011-01-01

    The enormous progress in the fields of microsystem technology, microelectronics and computer science has led to the development of powerful high speed cameras. Recently a number of such cameras became available as low cost consumer products which can also be used for the teaching of physics. The technology of high speed cameras is discussed,…

  14. High speed technology development and evaluation

    Science.gov (United States)

    Parker, D. R.; Brown, E. R.; Dickson, J. F.

    1986-10-01

    Semiconductor technology suited to high on-board data handling rates was investigated. Very high speed discrete logic and high speed gate arrays; single chip digital signal processors and single chip floating point processing peripherals; and analog CCD technologies and custom designed CCD chips for synthetic aperture radar applications were assessed. The 2 micron CMOS technology is highly reliable, supporting semicustom design techniques. Process JGC, the CCD technology, is highly reliable except for tolerance to ionizing radiation. Reliability of the ECL 16-bit serial-parallel parallel-serial converter junction isolated bipolar process, process WZA, is compromised by a design error and oxide contamination contributing to high leakage levels. The bipolar circuit is tolerant to an ionizing radiation of 20kRad. Step stress environmental testing to 200 C produces no failures in CMOS and CCD technologies, but accelerates the degradation of the oxide contaminated bipolar process. All technologies are susceptible to single event upsets.

  15. High Speed Wireless Signal Generation and Demodulation

    DEFF Research Database (Denmark)

    Caballero Jambrina, Antonio; Sambaraju, Rakesh; Zibar, Darko;

    We present the experimental demonstration of high speed wireless generation, up to 40 Gb/s, in the 75-110 GHz wireless band. All-optical OFDM and photonic up-conversion are used for generation and single side-band modulation with digital coherent detection for demodulation....

  16. High-speed Power Line Communications

    Directory of Open Access Journals (Sweden)

    Matthew N. O. Sadiku,

    2015-11-01

    Full Text Available This is the idea of using existing power lines for communication purposes. Power line communications (PLC enables network communication of voice, data, and video over direct power lines. High-speed PLC involves data rates in excess of 10 Mbps. PLC has attracted a lot of attention and has become an interesting subject of research lately.

  17. High-Speed Rail & Air Transport Competition

    NARCIS (Netherlands)

    Adler, Nicole; Nash, Chris; Pels, Eric

    2008-01-01

    This paper develops a methodology to assess transport infrastructure investments and their effects on a Nash equilibria taking into account competition between multiple privatized transport operator types. The operators, including high-speed rail, hub and spoke legacy airlines and low cost carriers,

  18. High speed adaptive liquid microlens array

    NARCIS (Netherlands)

    Murade, C.U.; van den Ende, Henricus T.M.; Mugele, Friedrich Gunther

    2012-01-01

    Liquid microlenses are attractive for adaptive optics because they offer the potential for both high speed actuation and parallelization into large arrays. Yet, in conventional designs, resonances of the liquid and the complexity of driving mechanisms and/or the device architecture have hampered a

  19. High speed multiplier design using Decomposition Logic

    Directory of Open Access Journals (Sweden)

    Ramanathan Palaniappan

    2009-01-01

    Full Text Available The multiplier forms the core of a Digital Signal Processor and is a major source of power dissipation. Often, the multiplier forms the limiting factor for the maximum speed of operation of a Digital Signal Processor. Due to continuing integrating intensity and the growing needs of portable devices, low-power, high-performance design is of prime importance. A new technique of implementing a multiplier circuit using Decomposition Logic is proposed here which improves speed with very little increase in power dissipation when compared to tree structured Dadda multipliers. Tanner EDA was used for simulation in the TSMC 180nm technology.

  20. High Speed SPM of Functional Materials

    Energy Technology Data Exchange (ETDEWEB)

    Huey, Bryan D. [Univ. of Connecticut, Storrs, CT (United States)

    2015-08-14

    The development and optimization of applications comprising functional materials necessitates a thorough understanding of their static and dynamic properties and performance at the nanoscale. Leveraging High Speed SPM and concepts enabled by it, efficient measurements and maps with nanoscale and nanosecond temporal resolution are uniquely feasible. This includes recent enhancements for topographic, conductivity, ferroelectric, and piezoelectric properties as originally proposed, as well as newly developed methods or improvements to AFM-based mechanical, friction, thermal, and photoconductivity measurements. The results of this work reveal fundamental mechanisms of operation, and suggest new approaches for improving the ultimate speed and/or efficiency, of data storage systems, magnetic-electric sensors, and solar cells.

  1. Sensor study for high speed autonomous operations

    Science.gov (United States)

    Schneider, Anne; La Celle, Zachary; Lacaze, Alberto; Murphy, Karl; Del Giorno, Mark; Close, Ryan

    2015-06-01

    As robotic ground systems advance in capabilities and begin to fulfill new roles in both civilian and military life, the limitation of slow operational speed has become a hindrance to the wide-spread adoption of these systems. For example, military convoys are reluctant to employ autonomous vehicles when these systems slow their movement from 60 miles per hour down to 40. However, these autonomous systems must operate at these lower speeds due to the limitations of the sensors they employ. Robotic Research, with its extensive experience in ground autonomy and associated problems therein, in conjunction with CERDEC/Night Vision and Electronic Sensors Directorate (NVESD), has performed a study to specify system and detection requirements; determined how current autonomy sensors perform in various scenarios; and analyzed how sensors should be employed to increase operational speeds of ground vehicles. The sensors evaluated in this study include the state of the art in LADAR/LIDAR, Radar, Electro-Optical, and Infrared sensors, and have been analyzed at high speeds to study their effectiveness in detecting and accounting for obstacles and other perception challenges. By creating a common set of testing benchmarks, and by testing in a wide range of real-world conditions, Robotic Research has evaluated where sensors can be successfully employed today; where sensors fall short; and which technologies should be examined and developed further. This study is the first step to achieve the overarching goal of doubling ground vehicle speeds on any given terrain.

  2. High speed printing with polygon scan heads

    Science.gov (United States)

    Stutz, Glenn

    2016-03-01

    To reduce and in many cases eliminate the costs associated with high volume printing of consumer and industrial products, this paper investigates and validates the use of the new generation of high speed pulse on demand (POD) lasers in concert with high speed (HS) polygon scan heads (PSH). Associated costs include consumables such as printing ink and nozzles, provisioning labor, maintenance and repair expense as well as reduction of printing lines due to high through put. Targets that are applicable and investigated include direct printing on plastics, printing on paper/cardboard as well as printing on labels. Market segments would include consumer products (CPG), medical and pharmaceutical products, universal ID (UID), and industrial products. In regards to the POD lasers employed, the wavelengths include UV(355nm), Green (532nm) and IR (1064nm) operating within the repetition range of 180 to 250 KHz.

  3. Safety issues in high speed machining

    Science.gov (United States)

    1994-05-01

    There are several risks related to High-Speed Milling, but they have not been systematically determined or studied so far. Increased loads by high centrifugal forces may result in dramatic hazards. Flying tools or fragments from a tool with high kinetic energy may damage surrounding people, machines and devices. In the project, mechanical risks were evaluated, theoretic values for kinetic energies of rotating tools were calculated, possible damages of the flying objects were determined and terms to eliminate the risks were considered. The noise levels of the High-Speed Machining center owned by the Helsinki University of Technology (HUT) and the Technical Research Center of Finland (VTT) in practical machining situation were measured and the results were compared to those after basic preventive measures were taken.

  4. High speed, high current pulsed driver circuit

    Energy Technology Data Exchange (ETDEWEB)

    Carlen, Christopher R.

    2017-03-21

    Various technologies presented herein relate to driving a LED such that the LED emits short duration pulses of light. This is accomplished by driving the LED with short duration, high amplitude current pulses. When the LED is driven by short duration, high amplitude current pulses, the LED emits light at a greater amplitude compared to when the LED is driven by continuous wave current.

  5. Counter-current thermocapillary migration of bubbles in self-rewetting liquids

    Science.gov (United States)

    Nazareth, R.; Saenz, P.; Sefiane, K.; Kim, J.; Valluri, P.

    2016-11-01

    In this work, we study the counter-current thermocapillary propulsion of a suspended bubble in the fluid flowing inside a channel subject to an axial temperature gradient when the surface tension dependence on temperature is non-monotonic. We use direct numerical simulations to address the two-phase conservation of mass, momentum and energy with a volume-of-fluid method to resolve the deformable interface. Two distinct regimes of counter-current bubble migration are characterized: i) "exponential decay" where the bubble decelerates rapidly until it comes to a halt at the spatial position corresponding to the minimum surface tension and ii) "sustained oscillations" where the bubble oscillates about the point of minimum surface tension. We illustrate how these sustained oscillations arise at low capillary number O(10-5) and moderate Reynolds number O(10) and, they are dampened by viscosity at lower Reynolds number. These results are in agreement with the experiments by Shanahan and Sefiane (Sci. Rep. 4, 2014). The work was supported by the Science without Borders program from CAPES agency of Brazilian Ministry of Education and the European Commission's Thermapower Project (294905).

  6. Purification of semiconducting single-walled carbon nanotubes by spiral counter-current chromatography.

    Science.gov (United States)

    Knight, Martha; Lazo-Portugal, Rodrigo; Ahn, Saeyoung Nate; Stefansson, Steingrimur

    2017-02-03

    Over the last decade man-made carbon nanostructures have shown great promise in electronic applications, but they are produced as very heterogeneous mixtures with different properties so the achievement of a significant commercial application has been elusive. The dimensions of single-wall carbon nanotubes are generally a nanometer wide, up to hundreds of microns long and the carbon nanotubes have anisotropic structures. They are processed to have shorter lengths but they need to be sorted by diameter and chirality. Thus counter-current chromatography methods developed for large molecules are applied to separate these compounds. A modified mixer-settler spiral CCC rotor made with 3 D printed disks was used with a polyethylene glycol-dextran 2-phase solvent system and a surfactant gradient to purify the major species in a commercial preparation. We isolated the semi-conducting single walled carbon nanotube chiral species identified by UV spectral analysis. The further development of spiral counter-current chromatography instrumentation and methods will enable the scalable purification of carbon nanotubes useful for the next generation electronics.

  7. Development of a Revolutionary High Speed Spindle

    Science.gov (United States)

    Agba, Emmanuel I.

    1999-01-01

    This report presents the development of a hydraulic motor driven spindle system to be employed for high speed machining of composite materials and metals. The spindle system is conceived to be easily retrofitted into conventional milling machines. The need for the hydraulic spindle arises because of the limitations placed on conventional electric motor driven spindles by the low cutting power and the presence of vibrational phenomena associated with voltage frequency at high rotational speeds. Also, the electric motors are usually large and expensive when power requirements are moderately high. In contrast, hydraulic motor driven spindles promise a distinct increase in spindle life over the conventional electric motor driven spindles. In this report, existing technologies applicable to spindle holder for severe operating conditions were reviewed, conceptual designs of spindle holder system were developed and evaluated, and a detailed design of an acceptable concept was conducted. Finally, a rapid prototype of the design was produced for design evaluation.

  8. Nanometer lapping technology at high speed

    Institute of Scientific and Technical Information of China (English)

    YANG JianDong; TIAN ChunLin; WANG ChangXing

    2007-01-01

    In floating lapping with solid abrasives, the workpiece is taken as an isolated body. The forces that act on it are analyzed. A differential equation about the forces that act on it is set up, so the forces that act on it and its motion rule are received. Combining it with known lapping tool motion, the relative motion rule between the lapping tool and workpiece is determined too. According to the relative motion, the distribution of abrasives density is designed reasonably, which makes the lapping tool wear uniformly, which, in turn, avoids redressing the lapping tool, saves abrasives, and increases machining accuracy. Combining it with advantages in high speed lapping with solid abrasives, the low cost, high efficiency nanometer lapping at high speed is realized.

  9. Nanometer lapping technology at high speed

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    In floating lapping with solid abrasives, the workpiece is taken as an isolated body. The forces that act on it are analyzed. A differential equation about the forces that act on it is set up, so the forces that act on it and its motion rule are received. Combining it with known lapping tool motion, the relative motion rule between the lapping tool and workpiece is determined too. According to the relative motion, the distribution of abrasives density is designed reasonably, which makes the lapping tool wear uniformly, which, in turn, avoids redressing the lapping tool, saves abra-sives, and increases machining accuracy. Combining it with advantages in high speed lapping with solid abrasives, the low cost, high efficiency nanometer lapping at high speed is realized.

  10. CMOS Image Sensors for High Speed Applications

    Directory of Open Access Journals (Sweden)

    M. Jamal Deen

    2009-01-01

    Full Text Available Recent advances in deep submicron CMOS technologies and improved pixel designs have enabled CMOS-based imagers to surpass charge-coupled devices (CCD imaging technology for mainstream applications. The parallel outputs that CMOS imagers can offer, in addition to complete camera-on-a-chip solutions due to being fabricated in standard CMOS technologies, result in compelling advantages in speed and system throughput. Since there is a practical limit on the minimum pixel size (4~5 μm due to limitations in the optics, CMOS technology scaling can allow for an increased number of transistors to be integrated into the pixel to improve both detection and signal processing. Such smart pixels truly show the potential of CMOS technology for imaging applications allowing CMOS imagers to achieve the image quality and global shuttering performance necessary to meet the demands of ultrahigh-speed applications. In this paper, a review of CMOS-based high-speed imager design is presented and the various implementations that target ultrahigh-speed imaging are described. This work also discusses the design, layout and simulation results of an ultrahigh acquisition rate CMOS active-pixel sensor imager that can take 8 frames at a rate of more than a billion frames per second (fps.

  11. CMOS Image Sensors for High Speed Applications.

    Science.gov (United States)

    El-Desouki, Munir; Deen, M Jamal; Fang, Qiyin; Liu, Louis; Tse, Frances; Armstrong, David

    2009-01-01

    Recent advances in deep submicron CMOS technologies and improved pixel designs have enabled CMOS-based imagers to surpass charge-coupled devices (CCD) imaging technology for mainstream applications. The parallel outputs that CMOS imagers can offer, in addition to complete camera-on-a-chip solutions due to being fabricated in standard CMOS technologies, result in compelling advantages in speed and system throughput. Since there is a practical limit on the minimum pixel size (4∼5 μm) due to limitations in the optics, CMOS technology scaling can allow for an increased number of transistors to be integrated into the pixel to improve both detection and signal processing. Such smart pixels truly show the potential of CMOS technology for imaging applications allowing CMOS imagers to achieve the image quality and global shuttering performance necessary to meet the demands of ultrahigh-speed applications. In this paper, a review of CMOS-based high-speed imager design is presented and the various implementations that target ultrahigh-speed imaging are described. This work also discusses the design, layout and simulation results of an ultrahigh acquisition rate CMOS active-pixel sensor imager that can take 8 frames at a rate of more than a billion frames per second (fps).

  12. Rapid separation of polysaccharides using a novel spiral coil column by high-speed countercurrent chromatography.

    Science.gov (United States)

    Li, Weili; Wu, Tao

    2016-04-01

    The separation of polysaccharides is time consuming. We developed and optimized a type-J counter-current chromatography system with a novel tri-rotor spiral coil column for the rapid separation of polysaccharides. The optimal composition of an aqueous PEG1000/K2 HPO4 /KH2 PO4 system was found to be 14:16:14 w/w/w where the lower phase was the mobile phase. Optimal performance was achieved at a column rotational speed, temperature, and flow rate of 1200 rpm, 45°C, and 3.0 mL/min, respectively. The mobile phase was pumped from the inner terminal in a ''head-to-tail'' elution mode. Polysaccharide LCP-1 (10.7 mg) was successfully obtained in high purity in one step from 50.0 mg of a crude polysaccharide extracted from the lychee fruit (Litchi chinensis) within 100 min. LCP-1 possess a number-average molecular weight and weight-average molecular weight of 1.05 × 10(5) and 1.59 × 10(5) kDa, respectively. The monosaccharide composition consists of the molar ratio of glucose, galactose, and arabinose of 1.3:3.5:1.

  13. High-speed tensile test instrument.

    Science.gov (United States)

    Mott, P H; Twigg, J N; Roland, D F; Schrader, H S; Pathak, J A; Roland, C M

    2007-04-01

    A novel high-speed tensile test instrument is described, capable of measuring the mechanical response of elastomers at strain rates ranging from 10 to 1600 s(-1) for strains through failure. The device employs a drop weight that engages levers to stretch a sample on a horizontal track. To improve dynamic equilibrium, a common problem in high speed testing, equal and opposite loading was applied to each end of the sample. Demonstrative results are reported for two elastomers at strain rates to 588 s(-1) with maximum strains of 4.3. At the higher strain rates, there is a substantial inertial contribution to the measured force, an effect unaccounted for in prior works using the drop weight technique. The strain rates were essentially constant over most of the strain range and fill a three-decade gap in the data from existing methods.

  14. High speed functional magnetic resonance imaging

    CERN Document Server

    Gibson, A M

    2002-01-01

    The work in this thesis has been undertaken by the except where indicated by reference, within the Magnetic Resonance Centre at the University of Nottingham during the period from October 1998 to October 2001. This thesis documents the implementation and application of a novel high-speed imaging technique, the multi-slice, echo shifted, echo planar imaging technique. This was implemented on the Nottingham 3 T imaging system, for functional magnetic resonance imaging. The technique uses echo shifting over the slices in a multi-slice echo planar imaging acquisition scheme, making the echo time longer than the repetition time per slice. This allows for rapid volumar sampling of the blood oxygen level dependent effect in the human brain. The new high-speed technique was used to investigate the variability of measuring the timing differences between haemodynamic responses, at the same cortical location, to simple cued motor tasks. The technique was also used in an investigation into motor cortex functional connect...

  15. High-speed massively parallel scanning

    Science.gov (United States)

    Decker, Derek E.

    2010-07-06

    A new technique for recording a series of images of a high-speed event (such as, but not limited to: ballistics, explosives, laser induced changes in materials, etc.) is presented. Such technique(s) makes use of a lenslet array to take image picture elements (pixels) and concentrate light from each pixel into a spot that is much smaller than the pixel. This array of spots illuminates a detector region (e.g., film, as one embodiment) which is scanned transverse to the light, creating tracks of exposed regions. Each track is a time history of the light intensity for a single pixel. By appropriately configuring the array of concentrated spots with respect to the scanning direction of the detection material, different tracks fit between pixels and sufficient lengths are possible which can be of interest in several high-speed imaging applications.

  16. The Aerodynamics of High Speed Aerial Weapons

    OpenAIRE

    Prince, Simon A.

    1999-01-01

    The focus of this work is the investigation of the complex compressible flow phenomena associated with high speed aerial weapons. A three dimen- sional multiblock finite volume flow solver was developed with the aim of studying the aerodynamics of missile configurations and their component structures. The first component of the study involved the aerodynamic investigation of the isolated components used in the design of conventional missile config- urations. The computati...

  17. A High-Speed Information Retrieval System

    Institute of Scientific and Technical Information of China (English)

    SHI Shu-dong; LI Zhi-tang

    2004-01-01

    We cleveloped a high-speed information retrieval system. The system hased on the IXP 2800 is one of the dedicute device. The velocily of the information retrieval is 6.8 Gb/s. The protocol support Telnet, FTP, SMTP, POP3 etc. various networks protocols. The information retrieval supports the key word and the natural language process. This paper explains the hardware system, software system and the index of the performance.

  18. Network Based High Speed Product Innovation

    DEFF Research Database (Denmark)

    Lindgren, Peter

    In the first decade of the 21st century, New Product Development has undergone major changes in the way NPD is managed and organised. This is due to changes in technology, market demands, and in the competencies of companies. As a result NPD organised in different forms of networks is predicted...... to be of ever-increasing importance to many different kinds of companies. This happens at the same times as the share of new products of total turnover and earnings is increasing at unprecedented speed in many firms and industries. The latter results in the need for very fast innovation and product development...... - a need that can almost only be resolved by organising NPD in some form of network configuration. The work of Peter Lindgren is on several aspects of network based high speed product innovation and contributes to a descriptive understanding of this phenomenon as well as with normative theory on how NPD...

  19. High-Speed Propeller for Aircraft

    Science.gov (United States)

    Sagerser, D. A.; Gatzen, B. S.

    1986-01-01

    Engine efficiency increased. Propeller blades required to be quite thin and highly swept to minimize compressibility losses and propeller noise during high-speed cruise. Use of 8 or 10 blades with highpropeller-power loading allows overall propeller diameter to be kept relatively small. Area-ruled spinner and integrated nacelle shape reduce compressibility losses in propeller hub region. Finally, large modern turboshaft engine and gearbox provide power to advanced propeller. Fuel savings of 30 to 50 percent over present systems anticipated. Propfan system adaptable to number of applications, such as highspeed (subsonic) business and general-aviation aircraft, and military aircraft including V/STOL.

  20. Counter-current flow in a vertical to horizontal tube with obstructions

    Energy Technology Data Exchange (ETDEWEB)

    Tye, P.; Matuszkiewicz, A.; Teyssedou, A. [Institut de Genie Nucleaire, Quebec (Canada)] [and others

    1995-09-01

    This paper presents experimental results on counter-current flow and flooding in an elbow between a vertical and a horizontal run. The experimental technique used allowed not only the flooding limit to be determined, but also the entire partial delivery region to be studied as well. The influence that various size orifices placed in the horizontal run have on both the delivered liquid flow rates and on the flooding limits is also examined. It is observed that both the flooding limits and the delivered liquid flow rates decrease with decreasing orifice size. Further, it is also observed that the mechanisms that govern the partial delivery of the liquid are significantly different when an orifice is present in the horizontal leg as compared to the case when no orifice is present.

  1. Experimental investigation of droplet separation in a horizontal counter-current air/water stratified flow; Experimentelle Untersuchung der Tropfenabscheidung einer horizontalen, entgegengerichteten Wasser/Luft-Schichtenstroemung

    Energy Technology Data Exchange (ETDEWEB)

    Gabriel, Stephan Gerhard

    2015-07-01

    A stratified counter-current two-phase gas/liquid flow can occur in various technical systems. In the past investigations have mainly been motivated by the possible occurrence of these flows in accident scenarios of nuclear light water-reactors and in numerous applications in process engineering. However, the precise forecast of flow parameters, is still challenging, for instance due to their strong dependency on the geometric boundary conditions. A new approach which uses CFD methods (Computational Fluid Dynamics) promises a better understanding of the flow phenomena and simultaneously a higher scalability of the findings. RANS methods (Reynolds Averaged Navier Stokes) are preferred in order to compute industrial processes and geometries. A very deep understanding of the flow behavior and equation systems based on real physics are necessary preconditions to develop the equation system for a reliable RANS approach with predictive power. Therefore, local highly resolved, experimental data is needed in order to provide and validate the required turbulence and phase interaction models. The central objective of this work is to provide the data needed for the code development for these unsteady, turbulent and three-dimensional flows. Experiments were carried out at the WENKA facility (Water Entrainment Channel Karlsruhe) at the Karlsruhe Institute of Technology (KIT). The work consists of a detailed description of the test-facility including a new bended channel, the measurement techniques and the experimental results. The characterization of the new channel was done by flow maps. A high-speed imaging study gives an impression of the occurring flow regimes, and different flow phenomena like droplet separation. The velocity distributions as well as various turbulence values were investigated by particle image velocimetry (PIV). In the liquid phase fluorescent tracer-particles were used to suppress optical reflections from the phase surface (fluorescent PIV, FPIV

  2. Initial performance of the High Speed Photometer

    Science.gov (United States)

    Richards, Evan; Percival, Jeff; Nelson, Matt; Hatter, ED; Fitch, John; White, Rick

    1991-01-01

    The Hubble Space Telescope High Speed Photometer has four image dissector tubes, two with UV sensitive photocathodes, two sensitive to the near UV and to visual light, and a single red sensitive photomultiplier tube. The HSP is capable of photometric measurements from 1200 to 7500 A with time resolution of 11 microseconds and has no moving parts. An initial analysis of the on-orbit engineering performance of the HSP is presented with changes in operating procedures resulting from the primary mirror spherical aberration and experience gained during the verification period.

  3. High Speed Solid State Circuit Breaker

    Science.gov (United States)

    Podlesak, Thomas F.

    1993-01-01

    The U.S. Army Research Laboratory, Fort Monmouth, NJ, has developed and is installing two 3.3 MW high speed solid state circuit breakers at the Army's Pulse Power Center. These circuit breakers will interrupt 4160V three phase power mains in no more than 300 microseconds, two orders of magnitude faster than conventional mechanical contact type circuit breakers. These circuit breakers utilize Gate Turnoff Thyristors (GTO's) and are currently utility type devices using air cooling in an air conditioned enclosure. Future refinements include liquid cooling, either water or two phase organic coolant, and more advanced semiconductors. Each of these refinements promises a more compact, more reliable unit.

  4. Accident Safety Design for High Speed Elevator

    Directory of Open Access Journals (Sweden)

    Tawiwat Veeraklaew

    2012-12-01

    Full Text Available There have been many elevators exist in buildings for such a long time; however, an accident might happen as a free fall due to lacks of maintenance or some other accident such as firing. Although this situation is rarely occurred, many people are still concerned about it. The question here is how to make passengers to feel safe and confident when they are using an elevator, especially, high speed elevator. This problem is studied here in this paper as a free fall spring-mass-damper system with the stiffness and damping coefficient can be computed as minimum jerk of the system with given constraints on trajectories.

  5. High Speed Telescopic Imaging of Sprites

    Science.gov (United States)

    McHarg, M. G.; Stenbaek-Nielsen, H. C.; Kanmae, T.; Haaland, R. K.

    2010-12-01

    A total of 21 sprite events were recorded at Langmuir Laboratory, New Mexico, during the nights of 14 and 15 July 2010 with a 500 mm focal length Takahashi Sky 90 telescope. The camera used was a Phantom 7.3 with a VideoScope image intensifier. The images were 512x256 pixels for a field of view of 1.3x0.6 degrees. The data were recorded at 16,000 frames per second (62 μs between images) and an integration time of 20 μs per image. Co-aligned with the telescope was a second similar high-speed camera, but with an 85 mm Nikon lens; this camera recorded at 10,000 frames per second with 100 μs exposure. The image format was also 512x256 pixels for a field of view of 7.3x3.7 degrees. The 21 events recorded include all basic sprite elements: Elve, sprite halos, C-sprites, carrot sprites, and large jellyfish sprites. We compare and contrast the spatial details seen in the different types of sprites, including streamer head size and the number of streamers subsequent to streamer head splitting. Telescopic high speed image of streamer tip splitting in sprites recorded at 07:06:09 UT on 15 July 2010.

  6. High-Speed RaPToRS

    Science.gov (United States)

    Henchen, Robert; Esham, Benjamin; Becker, William; Pogozelski, Edward; Padalino, Stephen; Sangster, Thomas; Glebov, Vladimir

    2008-11-01

    The High-Speed Rapid Pneumatic Transport of Radioactive Samples (HS-RaPToRS) system, designed to quickly and safely move radioactive materials, was assembled and tested at the Mercury facility of the Naval Research Laboratory (NRL) in Washington D.C. A sample, which is placed inside a four-inch-diameter carrier, is activated before being transported through a PVC tube via airflow. The carrier travels from the reaction chamber to the end station where it pneumatically brakes prior to the gate. A magnetic latch releases the gate when the carrier arrives and comes to rest. The airflow, optical carrier-monitoring devices, and end gate are controlled manually or automatically with LabView software. The installation and testing of the RaPToRS system at NRL was successfully completed with transport times of less than 3 seconds. The speed of the carrier averaged 16 m/s. Prospective facilities for similar systems include the Laboratory for Laser Energetics and the National Ignition Facility.

  7. High-speed ACR/NEMA interface

    Science.gov (United States)

    Reijns, Gerard L.; Santilli, D.; Schellingerhout, G.; Jochem, A. J.; Ottes, Fenno P.; van Aken, I. W.

    1990-08-01

    The design and implementation of a standard high speed ACR-NEMA communications interface is described. The upper layers e.g. the Presentation layer, Session layer and part of the Transport/Network layer have been implemented in software. In order to reach the speed requirement of 8M byte/sec. the lower layers e.g. part of the Transport/Network layer and Data Link layer have been implemented in hardware. We have developed and built an interface for an IBM personal computer P5/2 model 50, working under the operating system OS/2. The PS/2, model 50 has been equipped with a fast micro-channel bus, which enables a large throughput. The operating systern OS/2 has a multitasking capability, which enables concurrent programming. In order to minimize the delays, we used this multitasking facility to create a number of parallel operating "threads". The Transport/Network layer functions have been implemented using a receive thread, two send threads and a device driver with three hardware registers. The time to transfer a packet by DMA, to initiate the DMA logic and to execute the required Kernal functions have each been measured and figures are shown. The Data Link layer provides for storage of two packets in two separate random access memories (RAM's). These two RAM's enable a pipelined operation, which minimizes the delay in the Data Link layer.

  8. High Speed Fibre Optic Backbone LAN

    Science.gov (United States)

    Tanimoto, Masaaki; Hara, Shingo; Kajita, Yuji; Kashu, Fumitoshi; Ikeuchi, Masaru; Hagihara, Satoshi; Tsuzuki, Shinji

    1987-09-01

    Our firm has developed the SUMINET-4100 series, a fibre optic local area network (LAN), to serve the communications system trunk line needs for facilities, such as steel refineries, automobile plants and university campuses, that require large transmission capacity, and for the backbone networks used in intelligent building systems. The SUMINET-4100 series is already in service in various fields of application. Of the networks available in this series, the SUMINET-4150 has a trunk line speed of 128 Mbps and the multiplexer used for time division multiplexing (TDM) was enabled by designing an ECL-TTL gate array (3000 gates) based custom LSI. The synchronous, full-duplex V.24 and V.3.5 interfaces (SUMINET-2100) are provided for use with general purpose lines. And the IBM token ring network, the SUMINET-3200, designed for heterogeneous PCs and the Ethernet can all be connected to sub loops. Further, the IBM 3270 TCA and 5080 CADAM can be connected in the local mode. Interfaces are also provided for the NTT high-speed digital service, the digital PBX systems, and the Video CODEC system. The built-in loop monitor (LM) and network supervisory processor (NSP) provide management of loop utilization and send loop status signals to the host CPU's network configuration and control facility (NCCF). These built-in functions allow both the computer system and LAN to be managed from a single source at the host. This paper outlines features of the SUMINET-4150 and provides an example of its installation.

  9. Phase-field simulation of counter-current spontaneous imbibition in a fractured heterogeneous porous medium

    Science.gov (United States)

    Rokhforouz, M. R.; Akhlaghi Amiri, H. A.

    2017-06-01

    Spontaneous imbibition is well-known to be one of the most effective processes of oil recovery in fractured reservoirs. However, the detailed pore-scale mechanisms of the counter-current imbibition process and the effects of different fluid/rock parameters on this phenomenon have not yet been deeply addressed. This work presents the results of a new pore-level numerical study of counter-current spontaneous imbibition, using coupled Cahn-Hilliard phase field and Navier-Stokes equations, solved by a finite element method. A 2D fractured medium was constructed consisting of a nonhomogeneous porous matrix, in which the grains were represented by an equilateral triangular array of circles with different sizes and initially saturated with oil, and a fracture, adjacent to the matrix, initially saturated with water and supported by low rate water inflow. Through invasion of water into the matrix, oil drops were expelled one by one from the matrix to the fracture, and in the matrix, water progressed by forming capillary fingerings, with characteristics corresponding to the experimental observations. The effects of wettability, viscosity ratio, and interfacial tension were investigated. In strongly water-wet matrix, with grain contact angles of θ movement, water bridging, and oil drop detachment. It was notified that there was a specific grain contact angle for this simulated model, θ = π/4, above it, matrix oil recovery was negligible by imbibition, while below it, the imbibition rate and oil recovery were significantly increased by decreasing the contact angle. In simulated mixed wet models, water, coming from the fracture, just invaded the neighboring water-wet grains; the water front was stopped moving as it met the oil-wet grains or wide pores/throats. Increasing water-oil interfacial tension, in the range of 0.005-0.05 N/m, resulted in both higher rate of imbibition and higher ultimate oil recovery. Changing the water-oil viscosity ratio (M), in the range of 0

  10. High Speed Magnetostrictive MEMS Actuated Mirror Deflectors Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The main goal of this proposal is to develop high speed magnetostrictive and MEMS actuators for rapidly deflecting or deforming mirrors. High speed, light-weight,...

  11. High Speed Magnetostrictive MEMS Actuated Mirror Deflectors Project

    Data.gov (United States)

    National Aeronautics and Space Administration — We propose to develop high speed magnetostrictive and MEMS actuators for rapidly deflecting or deforming mirrors. High speed, light-weight, low voltage beam...

  12. Using a High-Speed Camera to Measure the Speed of Sound

    Science.gov (United States)

    Hack, William Nathan; Baird, William H.

    2012-01-01

    The speed of sound is a physical property that can be measured easily in the lab. However, finding an inexpensive and intuitive way for students to determine this speed has been more involved. The introduction of affordable consumer-grade high-speed cameras (such as the Exilim EX-FC100) makes conceptually simple experiments feasible. Since the…

  13. Using a High-Speed Camera to Measure the Speed of Sound

    Science.gov (United States)

    Hack, William Nathan; Baird, William H.

    2012-01-01

    The speed of sound is a physical property that can be measured easily in the lab. However, finding an inexpensive and intuitive way for students to determine this speed has been more involved. The introduction of affordable consumer-grade high-speed cameras (such as the Exilim EX-FC100) makes conceptually simple experiments feasible. Since the…

  14. HIGH SPEED INJECTION MOLDING OF HIGH DENSITY POLYETHYLENE - EFFECTS OF INJECTION SPEED ON STRUCTURE AND PROPERTIES

    Institute of Scientific and Technical Information of China (English)

    Kun Jiang; Feng Chen; Qiang Fu; Fei-long Yu; Run Su; Jing-hui Yang; Tian-nan Zhou; Jian Gao; Hua Deng; Ke Wang; Qin Zhang

    2011-01-01

    Thin wall samples of high density polyethylene (HDPE) were prepared via injection molding with differentinjection speeds ranging from 100 mm/s to 1200 mm/s. A significant decrease in the tensile strength and Young's moduluswas observed with increasing injection speed. In order to investigate the mechanism behind this decrease, the orientation,molecular weight, molecular weight distribution, melt flow rate, crystallinity and crystal morphology of HDPE werecharacterized using two-dimensional wide-angle X-ray diffraction (2D-WAXD), gel permeation chromatography (GPC),capillary rheometry and differential scanning calorimetry (DSC), respectively. It is demonstrated that the orientation,molecular weight, molecular weight distribution, melt flow rate and crystallinity have no obvious change with increasinginjection speed. Nevertheless, the content of extended chain crystals or large folded chain crystals was found to decreasewith increasing injection speed. Therefore, it is concluded that the decrease in tensile properties is mainly contributed by the reduced content of extended chain crystals or large folded chain crystals. This study provides industry with valuableinformation for the application of high speed injection molding.

  15. Design of A Novel High Speed Dynamic Comparator with Low Power Dissipation for High Speed ADCs

    Directory of Open Access Journals (Sweden)

    Sougata Ghosh

    2013-01-01

    Full Text Available A new CMOS dynamic comparator using dual input single output differential amplifier as latch stage suitable for high speed analog-to-digital converters with High Speed, low power dissipation and immune to noise than the previous reported work is proposed. Back to-back inverter in the latch stage is replaced with dual-input single output differential amplifier. This topology completely removes the noise that is present in the input. The structure shows lower power dissipation and higher speed than the conventional comparators. The circuit is simulated with 1V DC supply voltage and 250 MHz clock frequency. The proposed topology is based on two cross coupled differential pairs positive feedback and switchable current sources, has a lower power dissipation, higher speed, less area, and it is shown to be very robust against transistor mismatch, noise immunity. Previous reported comparators are designed and simulated their DC response and Transient response in Cadence®Virtuoso Analog Design Environment using GPDK 90nm technology. Layouts of the proposed comparator have been done in Cadence® Virtuoso Layout XL Design Environment. DRC and LVS has been checked and compared with the corresponding circuits and RC extracted diagram has been generated. After that post layout simulation with 1V supply voltage has been done and compared the speed, power dissipation, Area, delay with the results before layout and the superior features of the proposed comparator are established

  16. Neutron and high speed photogrammetric arcjet diagnosis

    Energy Technology Data Exchange (ETDEWEB)

    Stewart, P.A.E.; Rogers, J.D.; Fowler, P.H.; Deininger, W.D.; Taylor, A.D.

    1989-01-01

    Two methods for real time internal diagnostics of arcjet engines are described. One method uses cold, thermal, or epithermal neutrons. Cold neutrons are used to detect the presence and location of hydrogenous propellants. Thermal neutrons are used to delineate the edge contours of anode and cathode surfaces and to measure stress/strain. Epithermal neutrons are used to measure temperatures on arcjet surfaces, bulk material temperatures, and point temperatures in bulk materials. It is found that this method, with an exposure time of 10 min, produces at temperature accuracy for W or Re of + or - 2.5 C. The other method uses visible-light high-speed photogrammetry to obtain images of the transient behavior of the arc during start-up and to relate this behavior to electrial supply characteristics such as voltage, current, and ripple.

  17. Merging of high speed argon plasma jets

    Energy Technology Data Exchange (ETDEWEB)

    Case, A.; Messer, S.; Brockington, S.; Wu, L.; Witherspoon, F. D. [HyperV Technologies Corp., Chantilly, Virginia 22180 (United States); Elton, R. [University of Maryland, College Park, Maryland 20742 (United States)

    2013-01-15

    Formation of an imploding plasma liner for the plasma liner experiment (PLX) requires individual plasma jets to merge into a quasi-spherical shell of plasma converging on the origin. Understanding dynamics of the merging process requires knowledge of the plasma phenomena involved. We present results from the study of the merging of three plasma jets in three dimensional geometry. The experiments were performed using HyperV Technologies Corp. 1 cm Minirailguns with a preionized argon plasma armature. The vacuum chamber partially reproduces the port geometry of the PLX chamber. Diagnostics include fast imaging, spectroscopy, interferometry, fast pressure probes, B-dot probes, and high speed spatially resolved photodiodes, permitting measurements of plasma density, temperature, velocity, stagnation pressure, magnetic field, and density gradients. These experimental results are compared with simulation results from the LSP 3D hybrid PIC code.

  18. HIGH SPEED KERR CELL FRAMING CAMERA

    Science.gov (United States)

    Goss, W.C.; Gilley, L.F.

    1964-01-01

    The present invention relates to a high speed camera utilizing a Kerr cell shutter and a novel optical delay system having no moving parts. The camera can selectively photograph at least 6 frames within 9 x 10/sup -8/ seconds during any such time interval of an occurring event. The invention utilizes particularly an optical system which views and transmits 6 images of an event to a multi-channeled optical delay relay system. The delay relay system has optical paths of successively increased length in whole multiples of the first channel optical path length, into which optical paths the 6 images are transmitted. The successively delayed images are accepted from the exit of the delay relay system by an optical image focusing means, which in turn directs the images into a Kerr cell shutter disposed to intercept the image paths. A camera is disposed to simultaneously view and record the 6 images during a single exposure of the Kerr cell shutter. (AEC)

  19. High-Speed Low-Jitter Frequency Multiplication in CMOS

    NARCIS (Netherlands)

    van de Beek, R.C.H.

    2004-01-01

    This thesis deals with high-speed Clock and Frequency Multiplication. The term `high-speedù applies to both the output and the reference frequency of the multiplier. Much emphasis is placed on analysis and optimization of the total timing inaccuracies, and on implementing a high-speed feedback

  20. Photodetector having high speed and sensitivity

    Science.gov (United States)

    Morse, Jeffrey D.; Mariella, Jr., Raymond P.

    1991-01-01

    The present invention provides a photodetector having an advantageous combination of sensitivity and speed; it has a high sensitivity while retaining high speed. In a preferred embodiment, visible light is detected, but in some embodiments, x-rays can be detected, and in other embodiments infrared can be detected. The present invention comprises a photodetector having an active layer, and a recombination layer. The active layer has a surface exposed to light to be detected, and comprises a semiconductor, having a bandgap graded so that carriers formed due to interaction of the active layer with the incident radiation tend to be swept away from the exposed surface. The graded semiconductor material in the active layer preferably comprises Al.sub.1-x Ga.sub.x As. An additional sub-layer of graded In.sub.1-y Ga.sub.y As may be included between the Al.sub.1-x Ga.sub.x As layer and the recombination layer. The recombination layer comprises a semiconductor material having a short recombination time such as a defective GaAs layer grown in a low temperature process. The recombination layer is positioned adjacent to the active layer so that carriers from the active layer tend to be swept into the recombination layer. In an embodiment, the photodetector may comprise one or more additional layers stacked below the active and recombination layers. These additional layers may include another active layer and another recombination layer to absorb radiation not absorbed while passing through the first layers. A photodetector having a stacked configuration may have enhanced sensitivity and responsiveness at selected wavelengths such as infrared.

  1. High Speed/ Low Effluent Process for Ethanol

    Energy Technology Data Exchange (ETDEWEB)

    M. Clark Dale

    2006-10-30

    n this project, BPI demonstrated a new ethanol fermentation technology, termed the High Speed/ Low Effluent (HS/LE) process on both lab and large pilot scale as it would apply to wet mill and/or dry mill corn ethanol production. The HS/LE process allows very rapid fermentations, with 18 to 22% sugar syrups converted to 9 to 11% ethanol ‘beers’ in 6 to 12 hours using either a ‘consecutive batch’ or ‘continuous cascade’ implementation. This represents a 5 to 8X increase in fermentation speeds over conventional 72 hour batch fermentations which are the norm in the fuel ethanol industry today. The ‘consecutive batch’ technology was demonstrated on a large pilot scale (4,800 L) in a dry mill corn ethanol plant near Cedar Rapids, IA (Xethanol Biofuels). The pilot demonstrated that 12 hour fermentations can be accomplished on an industrial scale in a non-sterile industrial environment. Other objectives met in this project included development of a Low Energy (LE) Distillation process which reduces the energy requirements for distillation from about 14,000 BTU/gal steam ($0.126/gal with natural gas @ $9.00 MCF) to as low as 0.40 KW/gal electrical requirements ($0.022/gal with electricity @ $0.055/KWH). BPI also worked on the development of processes that would allow application of the HS/LE fermentation process to dry mill ethanol plants. A High-Value Corn ethanol plant concept was developed to produce 1) corn germ/oil, 2) corn bran, 3) ethanol, 4) zein protein, and 5) nutritional protein, giving multiple higher value products from the incoming corn stream.

  2. Continuous counter-current chromatography for capture and polishing steps in biopharmaceutical production.

    Science.gov (United States)

    Steinebach, Fabian; Müller-Späth, Thomas; Morbidelli, Massimo

    2016-09-01

    The economic advantages of continuous processing of biopharmaceuticals, which include smaller equipment and faster, efficient processes, have increased interest in this technology over the past decade. Continuous processes can also improve quality assurance and enable greater controllability, consistent with the quality initiatives of the FDA. Here, we discuss different continuous multi-column chromatography processes. Differences in the capture and polishing steps result in two different types of continuous processes that employ counter-current column movement. Continuous-capture processes are associated with increased productivity per cycle and decreased buffer consumption, whereas the typical purity-yield trade-off of classical batch chromatography can be surmounted by continuous processes for polishing applications. In the context of continuous manufacturing, different but complementary chromatographic columns or devices are typically combined to improve overall process performance and avoid unnecessary product storage. In the following, these various processes, their performances compared with batch processing and resulting product quality are discussed based on a review of the literature. Based on various examples of applications, primarily monoclonal antibody production processes, conclusions are drawn about the future of these continuous-manufacturing technologies.

  3. Sample injection strategy to increase throughput in counter-current chromatography: Case study of Honokiol purification.

    Science.gov (United States)

    Peng, Aihua; Hewitson, Peter; Ye, Haoyu; Zu, Liansuo; Garrard, Ian; Sutherland, Ian; Chen, Lijuan; Ignatova, Svetlana

    2016-12-09

    Counter-current chromatography (CCC) has been widely used as a preparative separation method to purify natural products from plant extracts and fermentation broths. Traditionally, throughput optimization in CCC has focused on sample concentration and sample volume. In this paper sample injection was considered as consisting of three variables: injection flow rate, post-injection flow rate and sample solvent. The effects of these parameters were studied using a honokiol purification from a Magnolia officinalis bark extract as a case study aiming to achieve the highest throughput/yield ratio for greater than 99% purity of this potential anti-cancer drug obtained for submission to the Chinese FDA. An injection method was established that increased the throughput of honokiol by 46.5% (from 3.05g/h to 4.47g/h), and decreased the solvent consumption of mobile phase and stationary phase per gram of honokiol by 40.0% (from 0.68L/g to 0.41L/g) and 48.4% (from 0.40L/g to 0.21L/g) respectively. These results show the importance of understanding the whole injection process when optimizing a given CCC separation.

  4. Pulsed counter-current ultrasound-assisted extraction and characterization of polysaccharides from Boletus edulis.

    Science.gov (United States)

    You, Qinghong; Yin, Xiulian; Ji, Chaowen

    2014-01-30

    Four methods for extracting polysaccharides from Boletus edulis, namely, hot-water extraction, ultrasonic clearer extraction, static probe ultrasonic extraction, and pulsed counter-current probe ultrasonic extraction (CCPUE), were studied. Results showed that CCPUE has the highest extraction efficiency among the methods studied. Under optimal CCPUE conditions, a B. edulis polysaccharide (BEP) yield of 8.21% was obtained. Three purified fractions, BEP-I, BEP-II, and BEP-III, were obtained through sequential purification by DEAE-52 and Sephadex G-75 chromatography. The average molecular weights of BEP-I, BEP-II, and BEP-III were 10,278, 23,761, and 42,736 Da, respectively. The polysaccharides were mainly composed of xylose, mannose, galactose, and glucose; of these, mannose contents were the highest. The antioxidant activities of the BEPs were further investigated by measurement of their ability to scavenge DPPH and hydroxyl radicals as well as their reducing power. The results indicated that the BEPs have good antioxidant activity.

  5. Effect of Coriolis force on counter-current chromatographic separation by centrifugal partition chromatography.

    Science.gov (United States)

    Ikehata, Jun-Ichi; Shinomiya, Kazufusa; Kobayashi, Koji; Ohshima, Hisashi; Kitanaka, Susumu; Ito, Yoichiro

    2004-02-06

    The effect of Coriolis force on the counter-current chromatographic separation was studied using centrifugal partition chromatography (CPC) with four different two-phase solvent systems including n-hexane-acetonitrile (ACN); tert-butyl methyl ether (MtBE)-aqueous 0.1% trifluoroacetic acid (TFA) (1:1); MtBE-ACN-aqueous 0.1% TFA (2:2:3); and 12.5% (w/w) polyethylene glycol (PEG) 1000-12.5% (w/w) dibasic potassium phosphate. Each separation was performed by eluting either the upper phase in the ascending mode or the lower phase in the descending mode, each in clockwise (CW) and counterclockwise column rotation. Better partition efficiencies were attained by the CW rotation in both mobile phases in all the two-phase solvent systems examined. The mathematical analysis also revealed the Coriolis force works favorably under the CW column rotation for both mobile phases. The overall results demonstrated that the Coriolis force produces substantial effects on CPC separation in both organic-aqueous and aqueous-aqueous two-phase systems.

  6. Isolation and purification of series bioactive components from Hypericum perforatum L. by counter-current chromatography.

    Science.gov (United States)

    Cao, Xueli; Wang, Qiaoe; Li, Yan; Bai, Ge; Ren, Hong; Xu, Chunming; Ito, Yoichiro

    2011-03-01

    Counter-current chromatography (CCC) combined with pre-separation by ultrasonic solvent extraction was successively used for the separation of series bioactive compounds from the crude extract of Hypericum perforatum L. The petroleum ether extract was separated by the solvent system of n-heptane-methanol-acetonitrile (1.5:0.5:0.5, v/v) and n-heptane-methanol (1.5:1, v/v) in gradient elution, yielding a phloroglucinol compound, hyperforin with HPLC purity over 98%. The ethyl acetate extract was separated by using the solvent system composed of hexane-ethyl acetate-methanol-water (1:1:1:1 and 1:3:1:3, v/v) in gradient through both reverse phase and normal phase elution mode, yielding a naphthodianthrone compound, hypericin with HPLC purity about 95%. The n-butanol extract was separated with the solvent system composed of n-butanol-ethyl acetate-water (1:4:5 and 1.5:3.5:5, v/v) in elution and back-extrusion mode, yielding two of flavones, rutin and hyperoside, with HPLC purity over 95%. HPLC-MS, reference sample and UV spectrum were selectively used in separation to search for target compounds from HPLC-DAD profiles of different sub-extracts. The structures of isolated compounds were further identified by ESI-MS, ¹HNMR and ¹³CNMR. Copyright © 2011 Elsevier B.V. All rights reserved.

  7. Mass transfer in thin films under counter-current gas: experiments and numerical study

    Science.gov (United States)

    Lucquiaud, Mathieu; Lavalle, Gianluca; Schmidt, Patrick; Ausner, Ilja; Wehrli, Marc; O Naraigh, Lennon; Valluri, Prashant

    2016-11-01

    Mass transfer in liquid-gas stratified flows is strongly affected by the waviness of the interface. For reactive flows, the chemical reactions occurring at the liquid-gas interface also influence the mass transfer rate. This is encountered in several technological applications, such as absorption units for carbon capture. We investigate the absorption rate of carbon dioxide in a liquid solution. The experimental set-up consists of a vertical channel where a falling film is sheared by a counter-current gas flow. We measure the absorption occurring at different flow conditions, by changing the liquid solution, the liquid flow rate and the gas composition. With the aim to support the experimental results with numerical simulations, we implement in our level-set flow solver a novel module for mass transfer taking into account a variant of the ghost-fluid formalism. We firstly validate the pure mass transfer case with and without hydrodynamics by comparing the species concentration in the bulk flow to the analytical solution. In a final stage, we analyse the absorption rate in reactive flows, and try to reproduce the experimental results by means of numerical simulations to explore the active role of the waves at the interface.

  8. Isolation of anti-HIV-1 lignans from Larrea tridentata by counter-current chromatography.

    Science.gov (United States)

    Gnabre, J N; Ito, Y; Ma, Y; Huang, R C

    1996-01-08

    Several lignans, mostly new, were isolated from Larrea tridentata by assay-guided counter-current chromatography (CCC). Using the secreted alkaline phosphatase bioassay of HIV Tat transactivation and the two-phase hexane-ethyl acetate-methanol-water solvent system, two major components (Gr and Lo) were identified as anti-HIV active principles. The chemical structures of the constituents of Gr (G1-G4) and Lo (L1-L4) were determined by GC-MS and NMR. After optimization of isolation conditions, a large-scale isolation with the chloroform-methanol-water system yielded five constituents (FB1-FB5). The most predominant anti-HIV compound FB2 (denoted Malachi 4:5-6 or mal.4), which occurs in 0.23% yield, was separated from its FB1 isomer (0.13% yield). Compound FB4 and two tricyclic lignans (FB3 and FB5) were also isolated in a substantial amount for further testing of their anti-HIV activities. These compounds may represent a new class of anti-HIV agents with important clinical relevance.

  9. VLSI circuits for high speed data conversion

    Science.gov (United States)

    Wooley, Bruce A.

    1994-05-01

    The focus of research has been the study of fundamental issues in the design and testing of data conversion interfaces for high performance VLSI signal processing and communications systems. Because of the increased speed and density that accompany the continuing scaling of VLSI technologies, digital means of processing, communicating, and storing information are rapidly displacing their analog counterparts across a broadening spectrum of applications. In such systems, the limitations on system performance generally occur at the interfaces between the digital representation of information and the analog environment in which the system is embedded. Specific results of this research include the design and implementation of low-power BiCMOS comparators and sample-and-hold amplifiers operating at clock rates as high as 200 MHz, the design and integration of a 12-bit, 5 MHz CMOS A/D converter employing a two-step architecture and a novel self-calibrating comparator, the design and integration of an optoelectronic communications receiver front-end in a GaAs-on-Si technology, the initiation of research into the use of an active silicon substrate probe card for fully testing high-performance mixed-signal circuits at the wafer level, and a preliminary study of means for correcting dynamic errors in high-performance A/D converters.

  10. Recovery of butanol by counter-current carbon dioxide fractionation with its potential application to butanol fermentation

    Science.gov (United States)

    A counter-current CO2 fractionation method was studied as a means to recover butanol (also known as 1-butanol or n-butanol) and other compounds that are typically obtained from biobutanol fermentation broth from aqueous solutions. The influence of operating parameters, such as solvent-to-feed ratio,...

  11. Mixer-settler counter-current chromatography with a barricaded spiral disk assembly with glass beads.

    Science.gov (United States)

    Ito, Yoichiro; Qi, Lin; Powell, Jimmie; Sharpnack, Frank; Metger, Howard; Yost, James; Cao, Xue-Li; Dong, Yin-Mao; Huo, Liang-Sheng; Zhu, Xiao-Ping; Li, Ting

    2007-06-01

    A novel spiral disk is designed by placing barricades at 6 mm intervals in the middle of the spiral channel to divide the channel into multiple sections. Glass beads are placed in every other section so that the planetary motion produces repetitive mixing and settling of polymer phase systems. Performance of this mixer-settler spiral disk assembly was examined for separation of lysozyme and myoglobin with a polymer phase system. The best results were obtained with a spiral disk equipped with barricades with openings ranging from 1.2 to 0.4 mm on each side at a high revolution speed up to 1200 rpm.

  12. High-tech maintenance for high-speed trains

    Energy Technology Data Exchange (ETDEWEB)

    Lopez, Javier Rutz [Nertus Mantenimiento Ferroviario, S.A., Madrid (Spain); Hofmann, Manfred [Siemens AG, Erlangen (Germany). Mobility Div., Integrated Services

    2011-03-15

    Reliable, punctual trains cannot do without professional maintenance. Nertus S.A., a joint subsidiary of Siemens and Renfe, is responsible for providing precisely this for the Spanish high-speed train, Velaro E (AVE S103), which operates between Madrid and Barcelona. (orig.)

  13. High-Speed Smart Camera with High Resolution

    Directory of Open Access Journals (Sweden)

    J. Dubois

    2007-02-01

    Full Text Available High-speed video cameras are powerful tools for investigating for instance the biomechanics analysis or the movements of mechanical parts in manufacturing processes. In the past years, the use of CMOS sensors instead of CCDs has enabled the development of high-speed video cameras offering digital outputs, readout flexibility, and lower manufacturing costs. In this paper, we propose a high-speed smart camera based on a CMOS sensor with embedded processing. Two types of algorithms have been implemented. A compression algorithm, specific to high-speed imaging constraints, has been implemented. This implementation allows to reduce the large data flow (6.55 Gbps and to propose a transfer on a serial output link (USB 2.0. The second type of algorithm is dedicated to feature extraction such as edge detection, markers extraction, or image analysis, wavelet analysis, and object tracking. These image processing algorithms have been implemented into an FPGA embedded inside the camera. These implementations are low-cost in terms of hardware resources. This FPGA technology allows us to process in real time 500 images per second with a 1280×1024 resolution. This camera system is a reconfigurable platform, other image processing algorithms can be implemented.

  14. High-Speed Smart Camera with High Resolution

    Directory of Open Access Journals (Sweden)

    Mosqueron R

    2007-01-01

    Full Text Available High-speed video cameras are powerful tools for investigating for instance the biomechanics analysis or the movements of mechanical parts in manufacturing processes. In the past years, the use of CMOS sensors instead of CCDs has enabled the development of high-speed video cameras offering digital outputs, readout flexibility, and lower manufacturing costs. In this paper, we propose a high-speed smart camera based on a CMOS sensor with embedded processing. Two types of algorithms have been implemented. A compression algorithm, specific to high-speed imaging constraints, has been implemented. This implementation allows to reduce the large data flow (6.55 Gbps and to propose a transfer on a serial output link (USB 2.0. The second type of algorithm is dedicated to feature extraction such as edge detection, markers extraction, or image analysis, wavelet analysis, and object tracking. These image processing algorithms have been implemented into an FPGA embedded inside the camera. These implementations are low-cost in terms of hardware resources. This FPGA technology allows us to process in real time 500 images per second with a 1280×1024 resolution. This camera system is a reconfigurable platform, other image processing algorithms can be implemented.

  15. High-temperature MAS-NMR at high spinning speeds.

    Science.gov (United States)

    Kirchhain, Holger; Holzinger, Julian; Mainka, Adrian; Spörhase, Andreas; Venkatachalam, Sabarinathan; Wixforth, Achim; van Wüllen, Leo

    2016-09-01

    A low cost version to enable high temperature MAS NMR experiments at temperatures of up to 700°C and spinning speeds of up to 10kHz is presented. The method relies on inductive heating using a metal coated rotor insert. The metal coating is accomplished via a two step process involving physical vapor deposition and galvanization.

  16. Material constraints on high-speed design

    Science.gov (United States)

    Bucur, Diana; Militaru, Nicolae

    2015-02-01

    Current high-speed circuit designs with signal rates up to 100Gbps and above are implying constraints for dielectric and conductive materials and their dependence of frequency, for component elements and for production processes. The purpose of this paper is to highlight through various simulation results the frequency dependence of specific parameters like insertion and return loss, eye diagrams, group delay that are part of signal integrity analyses type. In low-power environment designs become more complex as the operation frequency increases. The need for new materials with spatial uniformity for dielectric constant is a need for higher data rates circuits. The fiber weave effect (FWE) will be analyzed through the eye diagram results for various dielectric materials in a differential signaling scheme given the fact that the FWE is a phenomenon that affects randomly the performance of the circuit on balanced/differential transmission lines which are typically characterized through the above mentioned approaches. Crosstalk between traces is also of concern due to propagated signals that have tight rise and fall times or due to high density of the boards. Criteria should be considered to achieve maximum performance of the designed system requiring critical electronic properties.

  17. High-Speed Data Recorder for Space, Geodesy, and Other High-Speed Recording Applications

    Science.gov (United States)

    Taveniku, Mikael

    2013-01-01

    A high-speed data recorder and replay equipment has been developed for reliable high-data-rate recording to disk media. It solves problems with slow or faulty disks, multiple disk insertions, high-altitude operation, reliable performance using COTS hardware, and long-term maintenance and upgrade path challenges. The current generation data recor - ders used within the VLBI community are aging, special-purpose machines that are both slow (do not meet today's requirements) and are very expensive to maintain and operate. Furthermore, they are not easily upgraded to take advantage of commercial technology development, and are not scalable to multiple 10s of Gbit/s data rates required by new applications. The innovation provides a softwaredefined, high-speed data recorder that is scalable with technology advances in the commercial space. It maximally utilizes current technologies without being locked to a particular hardware platform. The innovation also provides a cost-effective way of streaming large amounts of data from sensors to disk, enabling many applications to store raw sensor data and perform post and signal processing offline. This recording system will be applicable to many applications needing realworld, high-speed data collection, including electronic warfare, softwaredefined radar, signal history storage of multispectral sensors, development of autonomous vehicles, and more.

  18. High Speed, Low Weight Momentum/Reaction Wheels

    OpenAIRE

    1999-01-01

    Advancements in several critical areas have made possible lightweight, strong and highly reliable momentum / reaction wheels. The development of reliable bearings with design features that allow high speed operation for space flight applications has significantly altered the weight / speed / wheel design considerations. Current designs typically operate at speeds at or below 6,000 RPM The new retainerless can achieve speeds 10 times that and meet or improve all other significant bearing opera...

  19. Modeling of high-speed electronic devices

    Directory of Open Access Journals (Sweden)

    V. G. Kudrya

    2013-09-01

    Full Text Available Introduction. The theme of this publication is the modeling of electronic tools that operate in the frequency range from zero to terahertz and higher. Application of new concepts and technologies, including biotechnology and nanotechnology in the development of monolithic integrated circuits led to a backlog of technologies of projecting from technologies and experimental research and manufacturing. The aim of this work is to develop algorithms for analysis, reflecting not only topological as well as morphological properties of the object, that is designing within the framework of accounting EMI communicational  transmission of energy and information in the volume of the monolithic integrated circuit. Basic steps for constructing the algorithm. The object of design is presented in the form of basic elements, which can be combined with a communication structure. The object of design is presented in the form of basic elements, which can be combined with a communication structure. There are three types of matrix equations: component; component - communication structure; communication structure. Systems of equations are reduced to standardized descriptors of mathematical model by which to understand current of poles and voltage arcs whole set of basic elements. In this way obtained mathematical model that can be implemented in CAD nano and micro technology electronics. Conclusions. Mathematical models of analysis of high-speed digital and analog electronic means. The algorithm allows morphological optimization is to minimize the adverse effects outside the system of electromagnetic interaction between the components and communicator.

  20. Enhanced high-speed coherent diffraction imaging

    Science.gov (United States)

    Potier, Jonathan; Fricker, Sebastien; Idir, Mourad

    2011-03-01

    Due to recent advances in X-ray microscopy, we are now able to image objects with nanometer resolution thanks to Synchrotron beam lines or Free Electron Lasers (FEL). The PCI (Phase Contrast Imaging) is a robust technique that can recover the wavefront from measurements of only few intensity pictures in the Fresnel diffraction region. With our fast straightforward calculus methods, we manage to provide the phase induced by a microscopic specimen in few seconds. We can therefore obtain high contrasted images from transparent materials at very small scales. To reach atomic resolution imaging and thus make a transition from the near to the far field, the Coherent Diffraction Imaging (CDI) technique finds its roots in the analysis of diffraction patterns to obtain the phase of the altered complex wave. Theoretical results about existence and uniqueness of this retrieved piece of information by both iterative and direct algorithms have already been released. However, performances of algorithms remain limited by the coherence of the X-ray beam, presence of random noise and the saturation threshold of the detector. We will present reconstructions of samples using an enhanced version of HIO algorithm improving the speed of convergence and its repeatability. As a first step toward a practical X-Ray CDI system, initial images for reconstructions are acquired with the laser-based CDI system working in the visible spectrum.

  1. High-speed image matching with coaxial holographic optical correlator

    Science.gov (United States)

    Ikeda, Kanami; Watanabe, Eriko

    2016-09-01

    A computation speed of more than 100 Gbps is experimentally demonstrated using our developed ultrahigh-speed optical correlator. To verify this high computation speed practically, the computation speeds of our optical correlator and conventional digital image matching are quantitatively compared. We use a population count function that achieves the fastest calculation speed when calculating binary matching by a central processing unit (CPU). The calculation speed of the optical correlator is dramatically faster than that using a CPU (2.40 GHz × 4) and 16 GB of random access memory, especially when the calculation data are large-scale.

  2. High Speed Dynamics in Brittle Materials

    Science.gov (United States)

    Hiermaier, Stefan

    2015-06-01

    Brittle Materials under High Speed and Shock loading provide a continuous challenge in experimental physics, analysis and numerical modelling, and consequently for engineering design. The dependence of damage and fracture processes on material-inherent length and time scales, the influence of defects, rate-dependent material properties and inertia effects on different scales make their understanding a true multi-scale problem. In addition, it is not uncommon that materials show a transition from ductile to brittle behavior when the loading rate is increased. A particular case is spallation, a brittle tensile failure induced by the interaction of stress waves leading to a sudden change from compressive to tensile loading states that can be invoked in various materials. This contribution highlights typical phenomena occurring when brittle materials are exposed to high loading rates in applications such as blast and impact on protective structures, or meteorite impact on geological materials. A short review on experimental methods that are used for dynamic characterization of brittle materials will be given. A close interaction of experimental analysis and numerical simulation has turned out to be very helpful in analyzing experimental results. For this purpose, adequate numerical methods are required. Cohesive zone models are one possible method for the analysis of brittle failure as long as some degree of tension is present. Their recent successful application for meso-mechanical simulations of concrete in Hopkinson-type spallation tests provides new insight into the dynamic failure process. Failure under compressive loading is a particular challenge for numerical simulations as it involves crushing of material which in turn influences stress states in other parts of a structure. On a continuum scale, it can be modeled using more or less complex plasticity models combined with failure surfaces, as will be demonstrated for ceramics. Models which take microstructural

  3. Experimental determination of the critical welding speed in high speed MAG welding

    Institute of Scientific and Technical Information of China (English)

    Hu Zhikun; Wu Chuansong

    2008-01-01

    In high speed MAG welding process, some weld formation defects may be encountered. To get good weld quality, the critical welding speed beyond which humping or undercutting weld bead can occur must be known for different conditions. In this research, high speed MAG welding tests were carried out to check out the effects of different factors on the critical welding speed. Through observing the weld bead profiles and the macrographs of the transverse sections of MAG welds, the occurrence tendency of humping weld was analyzed, and the values of critical welding speed were determined under different levels of welding current or voltage, and the effect of shielding gas compositions on the critical welding speed was also investigated.

  4. 622 Mbps High-speed satellite communication system for WINDS

    Science.gov (United States)

    Ogawa, Yasuo; Hashimoto, Yukio; Yoshimura, Naoko; Suzuki, Ryutaro; Gedney, Richard T.; Dollard, Mike

    2006-07-01

    WINDS is the experimental communications satellite currently under joint development by Japanese Aerospace Exploration Agency (JAXA) and the National Institute of Information and Communications Technology (NICT). The high-speed satellite communication system is very effective for quick deployment of high-speed networks economically. The WINDS will realize ultra high-speed networking and demonstrate operability of satellite communication systems in high-speed internet. NICT is now developing high-speed satellite communication system for WINDS. High-speed TDMA burst modem with high performance TPC error correction is underdevelopment. Up to the DAC on the transmitter and from the ADC on the receiver, all modem functions are performed in the digital processing technology. Burst modem has been designed for a user data rate up to 1244 Mbps. NICT is developing the digital terminal as a user interface and a network controller for this earth station. High compatibility with the Internet will be provided.

  5. High Speed Link Radiated Emission Reduction

    Science.gov (United States)

    Bisognin, P.; Pelissou, P.; Cissou, R.; Giniaux, M.; Vargas, O.

    2016-05-01

    To control the radiated emission of high-speed link and associated unit, the current approach is to implement overall harness shielding on cables bundles. This method is very efficient in the HF/ VHF (high frequency/ very high frequency) and UHF (ultra-high frequency) ranges when the overall harness shielding is properly bonded on EMC back-shell. Unfortunately, with the increasing frequency, the associated half wavelength matches with the size of Sub-D connector that is the case for the L band. Therefore, the unit connectors become the main source of interference emission. For the L-band and S-band, the current technology of EMC back-shell leaves thin aperture matched with the L band half wavelength and therefore, the shielding effectiveness is drastically reduced. In addition, overall harness shielding means significant increases of the harness mass.Airbus D&S Toulouse and Elancourt investigated a new solution to avoid the need of overall harness shielding. The objective is to procure EM (Electro-Magnetic) clean unit connected to cables bundles free of any overall harness shielding. The proposed solution is to implement EMC common mode filtering on signal interfaces directly on unit PCB as close as possible the unit connector.Airbus D&S Elancourt designed and manufactured eight mock-ups of LVDS (Low Voltage Differential Signaling) interface PCBs' with different solutions of filtering. After verification of the signal integrity, three mock-ups were retained (RC filter and two common mode choke coil) in addition to the reference one (without EMC filter).Airbus D&S Toulouse manufactured associated LVDS cable bundles and integrated the RX (Receiver) and TX (Transmitter) LVDS boards in shielded boxes.Then Airbus D&S performed radiated emission measurement of the LVDS links subassemblies (e.g. RX and TX boxes linked by LVDS cables) according to the standard test method. This paper presents the different tested solutions and main conclusions on the feasibility of such

  6. High-speed Stochastic Fatigue Testing

    DEFF Research Database (Denmark)

    Brincker, Rune; Sørensen, John Dalsgaard

    1990-01-01

    Good stochastic fatigue tests are difficult to perform. One of the major reasons is that ordinary servohydraulic loading systems realize the prescribed load history accurately at very low testing speeds only. If the speeds used for constant amplitude testing are applied to stochastic fatigue...... the analog control device remain as the basic control mechanism in the system, but distorting the input signal by computer in order to minimize the errors of the load history extremes. The principle proves to be very efficient to reduce all kinds of system errors and has shown to be able to increase...

  7. 33 CFR 84.24 - High-speed craft.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false High-speed craft. 84.24 Section... RULES ANNEX I: POSITIONING AND TECHNICAL DETAILS OF LIGHTS AND SHAPES § 84.24 High-speed craft. (a) The masthead light of high-speed craft with a length to breadth ratio of less than 3.0 may be placed at...

  8. Chicago-St. Louis high speed rail plan

    Energy Technology Data Exchange (ETDEWEB)

    Stead, M.E.

    1994-12-31

    The Illinois Department of Transportation (IDOT), in cooperation with Amtrak, undertook the Chicago-St. Louis High Speed Rail Financial and Implementation Plan study in order to develop a realistic and achievable blueprint for implementation of high speed rail in the Chicago-St. Louis corridor. This report presents a summary of the Price Waterhouse Project Team`s analysis and the Financial and Implementation Plan for implementing high speed rail service in the Chicago-St. Louis corridor.

  9. High Speed Switching Micoplasma in High Pressure Gases

    Science.gov (United States)

    Wakim, Dani; Staack, David

    2012-10-01

    Micro-plasma discharges with switching times approaching 1 ns are studied at pressures from 1 to 16 atm. Applications of these devices are robust high speed switching transistors able to withstand electric interference, high temperatures and harsh environments. Measured discharge conditions at 250 psia in Nitrogen are: gas temperature 2900 K, discharge diameter ˜7 μm and electron density ˜10^17 cm-3. High speed switching is achieved by taking advantage of rapid dynamics of instabilities at high pressure and high electron density. The capacitance and inductance of the circuit also significantly affect transients. Tradeoffs are observed in switching times. By reducing capacitances from 10 pF to ˜1pF attainment of steady state conditions can be reduced from 1 us to ˜ 20 ns. However current rise times increase from 1 ns at high capacitance to 20 ns at low capacitance. A decrease in switching time with increased pressure is also observed. Also investigated are configurations with a third electrode acting as a gate or trigger and various high temperature (>2000K) materials such as platinum rhodium alloys and ceria stabilized zirconia ceramics for device fabrication.

  10. Recovery of Butanol by Counter-Current Carbon Dioxide Fractionation with its Potential Application to Butanol Fermentation

    OpenAIRE

    Miriam Solana; Nasib Qureshi; Alberto Bertucco; Fred Eller

    2016-01-01

    A counter-current CO2 fractionation method was applied as a mean to recover n-butanol and other compounds that are typically obtained from biobutanol fermentation broth from aqueous solutions. The influence of operating variables, such as solvent-to-feed ratio, temperature, pressure and feed solution composition was experimentally studied in terms of separation efficiency, butanol removal rate, total removal and butanol concentration in the extract at the end of the continuous cycle. With res...

  11. BAYER COUNTER CURRENT SYSTEMS IN COMPARISON WITH CONVENTIONAL CO—CURRENT SYSTEM IN THE FIELD OF WATER TREATMENT

    Institute of Scientific and Technical Information of China (English)

    Mitschker.A; RauchfuB.K

    1994-01-01

    From an economical point of view both the quality of the ion exchange resins and the technology used in the field of industrial water treatment are important for a successful performance.In general,two different technologies have been established on the market:The main differneces between the CO-and counter current technologes will be discussed and data concerning the requirement of chemicals for regeneration and the quality of the deionized water will be opposed.In addition several different varieties of the modern counter current technologies,developed and patented by Bayer AG,will be described and the advantages,depending on the application and the demand on the quality of the deionized water,pointed out .In view of stronger regulations concerning the consumption of regeneration chemicals,and waste water,and also because of the superior quality of the produced water,the market share of counter current technologies will continue to increase world-wide.

  12. Preparative Separation of Six Rhynchophylla Alkaloids from Uncaria macrophylla Wall by pH-Zone Refining Counter-Current Chromatography

    Directory of Open Access Journals (Sweden)

    Qinghai Zhang

    2013-12-01

    Full Text Available pH-Zone refining counter-current chromatography was successfully applied to the preparative isolation and purification of six alkaloids from the ethanol extracts of Uncaria macrophylla Wall. Because of the low content of alkaloids (about 0.2%, w/w in U. macrophylla Wall, the target compounds were enriched by pH-zone refining counter-current chromatography using a two-phase solvent system composed of petroleum ether–ethyl acetate–isopropanol–water (2:6:3:9, v/v, adding 10 mM triethylamine in organic stationary phase and 5 mM hydrochloric acid in aqueous mobile phase. Then pH-zone refining counter-current chromatography using the other two-phase solvent system was used for final purification. Six target compounds were finally isolated and purified by following two-phase solvent system composed of methyl tert-butyl ether (MTBE–acetonitrile–water (4:0.5:5, v/v, adding triethylamine (TEA (10 mM to the organic phase and HCl (5 mM to aqueous mobile phase. The separation of 2.8 g enriched total alkaloids yielded 36 mg hirsutine, 48 mg hirsuteine, 82 mg uncarine C, 73 mg uncarine E, 163 mg rhynchophylline, and 149 mg corynoxeine, all with purities above 96% as verified by HPLC Their structures were identified by electrospray ionization-mass spectrometry (ESI-MS and 1H-NMR spectroscopy.

  13. High Speed and Wide Bandwidth Delta-Sigma ADCs

    NARCIS (Netherlands)

    Bolatkale, M.

    2013-01-01

    This thesis describes the theory, design and implementation of a high-speed, high-performance continuous-time delta-sigma (CTΔΣ) ADC for applications such as medical imaging, high-definition video processing, and wireline and wireless communications. In order to achieve a GHz clocking speed, this

  14. High Speed and Wide Bandwidth Delta-Sigma ADCs

    NARCIS (Netherlands)

    Bolatkale, M.

    2013-01-01

    This thesis describes the theory, design and implementation of a high-speed, high-performance continuous-time delta-sigma (CTΔΣ) ADC for applications such as medical imaging, high-definition video processing, and wireline and wireless communications. In order to achieve a GHz clocking speed, this th

  15. Installation position determination of wind speed sensors on steel pole along a high-speed railway

    Institute of Scientific and Technical Information of China (English)

    熊小慧; 梁习锋

    2016-01-01

    In order to consider the influence of steel pole on the measurement of wind speed sensors and determinate the installation position of wind speed sensors, the flow field around wind speed sensors was investigated. Based on the three-dimensional steady Reynolds-averaged Navier-Stokes equations andk-ε double equations turbulent model, the field flow around the wind speed sensor and the steel pole along a high-speed railway was simulated on an unstructured grid. The grid-independent validation was conducted and the accuracy of the present numerical simulation method was validated by experiments and simulations carried out by previous researchers. Results show that the steel pole has a significant influence on the measurement results of wind speed sensors. As the distance between two wind speed sensors is varied from 0.3 to 1.0 m, the impact angles are less than ±20°, it is proposed that the distance between two wind speed sensors is 0.8 m at least, and the interval between wind speed sensors and the steel pole is more than 1.0 m with the sensors located on the upstream side.

  16. Time optimal paths for high speed maneuvering

    Energy Technology Data Exchange (ETDEWEB)

    Reister, D.B.; Lenhart, S.M.

    1993-01-01

    Recent theoretical results have completely solved the problem of determining the minimum length path for a vehicle with a minimum turning radius moving from an initial configuration to a final configuration. Time optimal paths for a constant speed vehicle are a subset of the minimum length paths. This paper uses the Pontryagin maximum principle to find time optimal paths for a constant speed vehicle. The time optimal paths consist of sequences of axes of circles and straight lines. The maximum principle introduces concepts (dual variables, bang-bang solutions, singular solutions, and transversality conditions) that provide important insight into the nature of the time optimal paths. We explore the properties of the optimal paths and present some experimental results for a mobile robot following an optimal path.

  17. Design and Analysis of a High Speed Carry Select Adder

    OpenAIRE

    Simarpreet Singh Chawla; Swapnil Aggarwal; Anshika; Nidhi Goel

    2015-01-01

    An optimal high-speed and low-power VLSI architecture requires an efficient arithmetic processing unit that is optimized for speed and power consumption. Adders are one of the widely used in digital integrated circuit and system design.High speed adder is the necessary component in a data path, e.g. Microprocessors and a Digital signal processor. The present paper proposes a novel high-speed adder by combining the advantages of Carry Look Ahead Adder (CLAA) and Carry Select Adder (CSA), devis...

  18. Design and Analysis of a High Speed Carry Select Adder

    OpenAIRE

    Simarpreet Singh Chawla; Swapnil Aggarwal; Anshika; Nidhi Goel

    2015-01-01

    An optimal high-speed and low-power VLSI architecture requires an efficient arithmetic processing unit that is optimized for speed and power consumption. Adders are one of the widely used in digital integrated circuit and system design. High speed adder is the necessary component in a data path, e.g. Microprocessors and a Digital signal processor. The present paper proposes a novel high-speed adder by combining the advantages of Carry Look Ahead Adder (CLAA) and Carry Select Adder (CSA), devi...

  19. High speed twin roll casting of 6061 alloy strips

    OpenAIRE

    T. Haga; Sakaguchi, H.; H. Watari; S. Kumai

    2008-01-01

    Purpose: of this paper is to clear the possibility of high speed roll casting of thin strips of two aluminum alloys:6061 and recycled 6061. Mechanical properties of the roll cast 6061 and recycled 6061 strips were investigated inthe frame of this purpose.Design/methodology/approach: Methods used in the present study were high speed twin roll caster and lowtemperature casting. These methods were used to realize rapid solidification and increase the casting speed.Findings: are that 6061 and rec...

  20. Structural vulnerability and intervention of high speed railway networks

    Science.gov (United States)

    Zhang, Jianhua; Hu, Funian; Wang, Shuliang; Dai, Yang; Wang, Yixing

    2016-11-01

    This paper employs complex network theory to assess the structural vulnerability of high speed railway networks subjected to two different malicious attacks. Chinese, US and Japanese high speed railway networks are used to discuss the vulnerable characteristics of systems. We find that high speed railway networks are very fragile when suffering serious disturbances and two attack rules can cause analogous damages to one high speed railway network, which illustrates that the station with large degree possesses high betweenness, vice versa. Meanwhile, we discover that Japanese high speed railway network has the best global connectivity, but Chinese high speed railway network has the best local connectivity and possesses the largest transport capacity. Moreover, we find that there exist several redundant paths in Chinese high speed railway network and discover the critical stations of three HSRNs. Furthermore, the nearest-link method is adopted to implement topological interventions and to improve the connectivity and reliability of high speed railway networks. In addition, the feasibility and effectiveness of topological interventions are shown by simulations.

  1. Studies on the Effect of Column Angle in Figure-8 Centrifugal Counter-current Chromatography

    Science.gov (United States)

    Yang, Yi; Gu, Dongyu; Aisa, Haji Akber; Ito, Yoichiro

    2010-01-01

    The performance of the figure-8 column configuration in centrifugal counter-current chromatography was investigated by changing the angle between the column axis (a line through the central post and the peripheral post on which the figure-8 coil is wound) and the centrifugal force. The first series of experiments was performed using a polar two-phase solvent system composed of 1-butanol-acetic acid-water (4:1:5, v/v) to separate two dipeptide samples, Trp-Tyr and Val-Tyr, at a flow rate of 0.05 ml/min at 1000 rpm. When the column angle was changed from 0° (column axis parallel to the centrifugal force) to 45° and 45° to 90° (column axis perpendicular to the centrifugal force), peak resolution (Rs) changed from 1.93 (Sf = 37.8%) to 1.54 (Sf=30.6%), then to 1.31 (Sf = 40.5%) with the lower mobile phase and from 1.21 (Sf = 38.8%) to 1.10 (Sf =34.4%), then to 0.99 (Sf = 42.2%) with the upper mobile phase, respectively, where the stationary phase retention, Sf, is given in parentheses. The second series of experiments was similarly performed with a more hydrophobic two-phase solvent system composed of hexane-ethyl acetate-metanol-0.1M hydrochloric acid (1:1:1:1, v/v) to separate three DNP-amino acids, DNP-glu, DNP-α-ala and DNP-ala, at a flow rate of 0.05 ml/min at 1000 rpm. When the column angle was altered from 0° to 45° and 45° to 90°, Rs changed from 1.77 (1st peak/ 2nd peak) and 1.52 (2nd peak/3rd peak) (Sf = 27.3%) to 1.24 and 1.02 (Sf = 35.4%), then to 1.69 and 1.49 (Sf = 42.1%) with the lower mobile phase, and from 1.73 and 0.84 (SF = 41.2%) to 1.44 and 0.73 (Sf = 45.6%), then to 1.21 and 0.63 (Sf = 55.6%) with the upper mobile phase, respectively. The performance of figure-8 column at 0° and 90° was also compared at different flow rates. The results show that Rs was increased with decreased flow rate yielding the highest value at the 0° column angle with lower mobile phase. The overall results of our studies indicated that a 0° column angle for the

  2. Bubble snap-off and capillary-back pressure during counter-current spontaneous imbibition into model pores.

    Science.gov (United States)

    Unsal, Evren; Mason, Geoffrey; Morrow, Norman R; Ruth, Douglas W

    2009-04-09

    A previous paper (Unsal, E.; Mason, G.; Ruth, D. W.; Morrow, N. R. J. Colloid Interface Sci. 2007, 315, 200-209) reported experiments involving counter-current spontaneous imbibition into a model pore system consisting of a rod in an angled slot covered by a glass plate. Such an arrangement gives two tubes with different cross-sections (both size and shape) with an interconnection through the gap between the rod and the plate. In the previous experiments, the wetting phase advanced in the small tube and nonwetting phase retreated in the large tube. No bubbles were formed. In this paper, we study experimentally and theoretically the formation of bubbles at the open end of the large tube and their subsequent snap-off. Such bubbles reduce the capillary back pressure produced by the larger tube and can thus have an effect on the local rate of imbibition. In the model pore system, the rod was either in contact with the glass, forming two independent tubes, or the rod was spaced from the glass to allow cross-flow between the tubes. For small gaps, there were three distinct menisci. The one with the highest curvature was between the rod and the plate. The next most highly curved was in the smaller tube, and the least highly curved meniscus was in the large tube and this was the tube from which the bubbles developed. The pressure in the dead end of the system was recorded during imbibition. Once the bubble starts to form outside of the tube, the pressure drops rapidly and then steadies. After the bubble snaps off, the pressure rises to almost the initial value and stays essentially constant until the next bubble starts to form. After snap-off, the meniscus in the large tube appears to invade the large tube for some distance. The snap-off is the result of capillary instability; it takes place significantly inside the large tube with flow of wetting phase moving in the angular corners. As imbibition into the small tube progresses, the rate of imbibition decreases and the

  3. High speed matrix processors using floating point representation

    Energy Technology Data Exchange (ETDEWEB)

    Birkner, D.A.

    1980-01-01

    The author describes the architecture of a high-speed matrix processor which uses a floating-point format for data representation. It is shown how multipliers and other LSI devices are used in the design to obtain the high speed of the processor.

  4. High-Speed Photo-Polarimetry of Magnetic Cataclysmic Variables

    Directory of Open Access Journals (Sweden)

    S. B. Potter

    2015-02-01

    Full Text Available I review recent highlights of the SAAO High-speed Photo-POlarimeter (HIPPO on the study of magnetic Cataclysmic Variables. Its high-speed capabilities are demonstrated with example observations made of the intermediate polar NY Lup and the polar IGRJ14536-5522.

  5. Visualization of the boiling phenomena and counter-current flow limit of annular heat pipe

    Energy Technology Data Exchange (ETDEWEB)

    Kim, In Guk; Kim, Kyung Mo; Jeong, Yeong Shin; Bang, In Cheol [UNIST, Ulsan (Korea, Republic of)

    2015-10-15

    The thermal resistance of conventional heat pipes increases over the capillary limit because of the insufficient supplement of the working fluid. Due to the shortage of the liquid supplement, thermosyphon is widely used for vertically oriented heat transport and high heat load conditions. Thermosyphons are two-phase heat transfer devices that have the highly efficient heat transport from evaporation to condensation section that makes an upward driving force for vapor. In the condenser section, the vapor condenses and releases the latent heat. Due to the gravitation force acting on the liquid in the tube, working fluid back to the evaporator section, normally this process operate at the vertical and inclination position. The use of two-phase closed thermosyphon (TPCT) for the cooling devices has the limitation due to the phase change of the working fluid assisted by gravity force. Due to the complex phenomenon of two-phase flow, it is required to understand what happened in TPCT. The visualization of the thermosyphon and heat pipe is investigated for the decrease of thermal resistance and enhancement of operation limit. Weibel et al. investigated capillary-fed boiling of water with porous sintered powder wick structure using high speed camera. At the high heat flux condition, dry-out phenomenon and a thin liquid film are observed at the porous wick structure. Wong and Kao investigated the evaporation and boiling process of mesh wicked heat pipe using optical camera. At the high heat flux condition, the water filing became thin and partial dry-out was observed in the evaporator section. Our group suggested the concept of a hybrid heat pipe with control rod as Passive IN-core Cooling System (PINCs) for decay heat removal for advanced nuclear power plant. The hybrid heat pipe is the combination of the heat pipe and control rod. It is necessary for PINCs to contain a neutron absorber (B{sub 4}C) to have the ability of reactivity control. It has annular vapor space and

  6. High Speed Linear Induction Motor Efficiency Optimization

    Science.gov (United States)

    2005-06-01

    rotor d. 2 heightrotor ae + overhang length scon p-r length~~ 0 .5 7eto siemens .85 cru=5. 7-10 7 ___ se esc l:-z2.-17 siemens width: 100ikn 3.5 N:= 3...Vsnhs1482 Fp ot( slip1 ot) I K_______iplo)slppo speed ( slippiot) Vsych’ I~ nx sip (lipot 7t 2.106 1.5-.10 6 _ F~l0(s 5-100~ 5 50~ 0.9 0.8 0.7 0.6 0.5

  7. High Speed Laser 3D Measurement System

    Institute of Scientific and Technical Information of China (English)

    SONG Yuan-he; FAN Chang-zhou; GUO Ying; LI Hong-wei; ZHAO Hong

    2003-01-01

    Using the method of line structure light produced by a laser diode,three dimensional profile measurement is deeply researched.A hardware circuit developed is used to get the center position of light section for the improvement of the measurement speed.A double CCD compensation technology is used to improve the measurement precision. An easy and effective calibration method of the least squares to fit the parameter of system structure is used to get the relative coordinate relationship of objects and images of light section in the directions of height and axis. Sensor scanning segment by segment and layer by layer makes the measurement range expand greatly.

  8. Maneuverability Estimation of High-Speed Craft

    Science.gov (United States)

    2015-06-01

    different g-forces. The air-to-surface missile (Penguin anti-ship missile , AGM-114B/K/M Hellfire missile ) has a maximum speed around Mach 1.2. I assume...attacked by a missile . Three different attacking situations are analyzed in missile -vessel interactions for the safety of the vessel, and the optimum...distance has been found to start the escape maneuver. According to these escape situations, the missile should maintain a certain g-force to make an

  9. High Speed Sonar Array Depressor Program

    Science.gov (United States)

    1981-11-30

    were conducted in the Exuma Sound In August 1981. 33 Report 12482 1000 4000 z 3000 2000 - 500 1000 0 1I 0 0 5 10 15 20 25 30 SPEED-KNOTS 700 1:11 IS z...the ONR Sea Trial 1A6 on the R/V ATHENA. The depressor was deployed during that portion of the trials occuring on 5, 6, 7 and 8 August 1981 in Exuma ...Before the Exuma Sound runs the bolt holes in tVe depressor were permanently plugged and faired. From then on no relation was seen between the sign

  10. Spontaneous sidebanding in high speed rotordynamics

    Science.gov (United States)

    Ehrich, F. F.

    1992-10-01

    It is noted that the spontaneous sideband spacing frequency seems to be a whole number fraction (1/J) of the operating speed which indicates that the wave form is periodic and completes a full cycle every J rotations of the rotor. Employing a numerical model of a rotor that simulates local contact with a stator in close proximity as a bilinear spring, studies have been conducted to explore the circumstances for this spontaneous sidebanding. Two general classes of this type of response are determined in a system that is effectively single-degree-of-freedom.

  11. Intelligent high-speed cutting database system development

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    In this paper,the components of a high-speed cutting system are analyzed firstly.The component variables of the high-speed cutting system are classified into four types:uncontrolled variables,process variables,control variables,and output variables.The relationships and interactions of these variables are discussed.Then,by analyzing and comparing intelligent reasoning methods frequently used,the hybrid reasoning is employed to build the high-speed cutting database system.Then,the data structures of high-speed cutting case base and databases are determined.Finally,the component parts and working process of the high-speed cutting database system on the basis of hybrid reasoning are presented.

  12. Wake flow characteristics at high wind speed

    DEFF Research Database (Denmark)

    Aagaard Madsen, Helge; Larsen, Torben J.; Larsen, Gunner Chr.

    2016-01-01

    power. In the present study we simulate the wake flow for a row of turbines with the wind aligned with the row using a simplified approach. The velocity deficit, being a function of the thrust coefficient, is simulated based on the BEM solution for wake expansion. An axis-symmetric boundary layer...... equation model (the same as implemented in the DWM model) is subsequently used to develop the deficit down to the next turbine, and then the approach is successively repeated. Simulation results for four different spacing’s in a row with eight turbines show that there are two major flow regimes...... in the intersection region between the two flow regimes a strong variation in power and thrust occur, e.g. going from almost zero power to rated power for a wind speed change of 4m/s. Another result is that the inflow profile to the last turbine in the row at a wind speed of 16m/s for a spacing of 3D shows...

  13. Effect of welding current and speed on occurrence of humping bead in high-speed GMAW

    Institute of Scientific and Technical Information of China (English)

    Chen Ji; Wu Chuansong

    2009-01-01

    The developed mathematical model of humping formation mechanism in high-speed gas metal arc welding (GMAW) is used to analyze the effects of welding current and welding speed on the occurrence of humping bead. It considers both the momentum and heat content of backward flowing molten jet inside weld pool. Three-dimensional geometry of weld pool, the spacing between two adjacent humps and hump height along humping weld bead are calculated under different levels of welding current and welding speed. It shows that wire feeding rate, power intensity and the moment of backward flowing molten jet are the major factors on humping bead formation.

  14. Next Generation Modeling Technology for High Speed Rotorcraft Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Development of a new generation of high speed rotorcraft has been hampered by both an absence of strong predictive methods for rotors operating at very high advance...

  15. High-speed camera characterization of voluntary eye blinking kinematics.

    Science.gov (United States)

    Kwon, Kyung-Ah; Shipley, Rebecca J; Edirisinghe, Mohan; Ezra, Daniel G; Rose, Geoff; Best, Serena M; Cameron, Ruth E

    2013-08-01

    Blinking is vital to maintain the integrity of the ocular surface and its characteristics such as blink duration and speed can vary significantly, depending on the health of the eyes. The blink is so rapid that special techniques are required to characterize it. In this study, a high-speed camera was used to record and characterize voluntary blinking. The blinking motion of 25 healthy volunteers was recorded at 600 frames per second. Master curves for the palpebral aperture and blinking speed were constructed using palpebral aperture versus time data taken from the high-speed camera recordings, which show that one blink can be divided into four phases; closing, closed, early opening and late opening. Analysis of data from the high-speed camera images was used to calculate the palpebral aperture, peak blinking speed, average blinking speed and duration of voluntary blinking and compare it with data generated by other methods previously used to evaluate voluntary blinking. The advantages of the high-speed camera method over the others are discussed, thereby supporting the high potential usefulness of the method in clinical research.

  16. High speed sampling circuit design for pulse laser ranging

    Science.gov (United States)

    Qian, Rui-hai; Gao, Xuan-yi; Zhang, Yan-mei; Li, Huan; Guo, Hai-chao; Guo, Xiao-kang; He, Shi-jie

    2016-10-01

    In recent years, with the rapid development of digital chip, high speed sampling rate analog to digital conversion chip can be used to sample narrow laser pulse echo. Moreover, high speed processor is widely applied to achieve digital laser echo signal processing algorithm. The development of digital chip greatly improved the laser ranging detection accuracy. High speed sampling and processing circuit used in the laser ranging detection system has gradually been a research hotspot. In this paper, a pulse laser echo data logging and digital signal processing circuit system is studied based on the high speed sampling. This circuit consists of two parts: the pulse laser echo data processing circuit and the data transmission circuit. The pulse laser echo data processing circuit includes a laser diode, a laser detector and a high sample rate data logging circuit. The data transmission circuit receives the processed data from the pulse laser echo data processing circuit. The sample data is transmitted to the computer through USB2.0 interface. Finally, a PC interface is designed using C# language, in which the sampling laser pulse echo signal is demonstrated and the processed laser pulse is plotted. Finally, the laser ranging experiment is carried out to test the pulse laser echo data logging and digital signal processing circuit system. The experiment result demonstrates that the laser ranging hardware system achieved high speed data logging, high speed processing and high speed sampling data transmission.

  17. Research on Aerodynamic Noise Reduction for High-Speed Trains

    OpenAIRE

    Yadong Zhang; Jiye Zhang; Tian Li; Liang Zhang; Weihua Zhang

    2016-01-01

    A broadband noise source model based on Lighthill’s acoustic theory was used to perform numerical simulations of the aerodynamic noise sources for a high-speed train. The near-field unsteady flow around a high-speed train was analysed based on a delayed detached-eddy simulation (DDES) using the finite volume method with high-order difference schemes. The far-field aerodynamic noise from a high-speed train was predicted using a computational fluid dynamics (CFD)/Ffowcs Williams-Hawkings (FW-H)...

  18. Research on Aerodynamic Noise Reduction for High-Speed Trains

    OpenAIRE

    Yadong Zhang; Jiye Zhang; Tian Li; Liang Zhang; Weihua Zhang

    2016-01-01

    A broadband noise source model based on Lighthill’s acoustic theory was used to perform numerical simulations of the aerodynamic noise sources for a high-speed train. The near-field unsteady flow around a high-speed train was analysed based on a delayed detached-eddy simulation (DDES) using the finite volume method with high-order difference schemes. The far-field aerodynamic noise from a high-speed train was predicted using a computational fluid dynamics (CFD)/Ffowcs Williams-Hawkings (FW-H)...

  19. Characterizing speed-independence of high-level designs

    DEFF Research Database (Denmark)

    Kishinevsky, Michael; Staunstrup, Jørgen

    1994-01-01

    types, and internal as well as external non-determinism. This makes it possible to verify the speed-independence of a design without providing an explicit realization of the environment. The verification can be done mechanically. A number of experimental designs have been verified including a speed......This paper characterizes the speed-independence of high-level designs. The characterization is a condition on the design description ensuring that the behavior of the design is independent of the speeds of its components. The behavior of a circuit is modeled as a transition system, that allows data...

  20. Review of High-Speed Fiber Optic Grating Sensors Systems

    Energy Technology Data Exchange (ETDEWEB)

    Udd, E; Benterou, J; May, C; Mihailov, S J; Lu, P

    2010-03-24

    Fiber grating sensors can be used to support a wide variety of high speed measurement applications. This includes measurements of vibrations on bridges, traffic monitoring on freeways, ultrasonic detection to support non-destructive tests on metal plates and providing details of detonation events. This paper provides a brief overview of some of the techniques that have been used to support high speed measurements using fiber grating sensors over frequency ranges from 10s of kHz, to MHZ and finally toward frequencies approaching the GHz regime. Very early in the development of fiber grating sensor systems it was realized that a high speed fiber grating sensor system could be realized by placing an optical filter that might be a fiber grating in front of a detector so that spectral changes in the reflection from a fiber grating were amplitude modulated. In principal the only limitation on this type of system involved the speed of the output detector which with the development of high speed communication links moved from the regime of 10s of MHz toward 10s of GHz. The earliest deployed systems involved civil structures including measurements of the strain fields on composite utility poles and missile bodies during break tests, bridges and freeways. This was followed by a series of developments that included high speed fiber grating sensors to support nondestructive testing via ultrasonic wave detection, high speed machining and monitoring ship hulls. Each of these applications involved monitoring mechanical motion of structures and thus interest was in speeds up to a few 10s of MHz. Most recently there has been interest in using fiber grating to monitor the very high speed events such as detonations and this has led to utilization of fiber gratings that are consumed during an event that may require detection speeds of hundreds of MHz and in the future multiple GHz.

  1. Incorporating YBCO Coated Conductors in High-speed Superconducting Generators

    Science.gov (United States)

    2008-07-01

    4.0 kW/lb (8.82 kW/kg). The machine configuration chosen by GE for design was a homopolar inductor alternator (HIA) which locates the...extremely severe ac loss environment. Even if this is ultimately impossible for high speed generators, it may not preclude lower speed motors and

  2. High-speed display system for animation using multimicrocomputer

    Energy Technology Data Exchange (ETDEWEB)

    Onda, K.; Oako, Y.

    1983-01-01

    A high-speed display system architecture for computer animation is proposed. Many picture memories, each of which is connected to a microcomputer, and display controller are used for producing and displaying pictures in parallel. This system can be realized with low-speed processors without specific hardwares to display natural movement. 1 ref.

  3. HULL GESTURE AND RESISTANCE PREDICTION OF HIGH-SPEED VESSELS*

    Institute of Scientific and Technical Information of China (English)

    NI Chong-ben; ZHU Ren-chuan; MIAO Guo-ping; FAN Ju

    2011-01-01

    Since trim and sinkage are significant while vessels are advancing forward with high speed, the predicted vessel resistance based on restrained model theory or experiment may not be real resistance of vessels during voyage. It is necessary to take the influence of hull gesture into account for oredicting the resistance of high-speed ship. In the present work the resistance problem of high speed ship is treated with the viscous flow theory, and the dynamic mesh technique is adopted to coincide with variation of hull gesture of high speed vessel on voyage. The simulation of the models of S60 ship and a trimaran moving in towing tank with high speed are conducted by using the above theory and technique. The corresponding numerical results are in good agreement with the experimental data. It indicates that the resistance prediction for high speed vessels should take hull gesture into consideration and the dynamic mesh method proposed here is effective in calculating the resistance of high speed vessels.

  4. Application Of High Speed Photography In Science And Technology

    Science.gov (United States)

    Wu Ji-Zong, Wu; Yu-Ju, Lin

    1983-03-01

    The service works in high-speed photography carried out by the Department of Precision Instruments, Tianjin University are described in this paper. A compensation type high-speed camera was used in these works. The photographic methods adopted and better results achieved in the studies of several technical fields, such as velocity field of flow of overflow surface of high dam, combustion process of internal combustion engine, metal cutting, electrical are welding, experiment of piling of steel tube piles for supporting the marine platforms and characteristics of motion of wrist watch escape mechanism and so on are illustrated in more detail. As the extension of human visual organs and for increasing the abi-lities of observing and studying the high-speed processes, high-speed photography plays a very important role. In order to promote the application and development on high-speed photography, we have carried out the consultative and service works inside and outside Tianjin Uni-versity. The Pentazet 35 compensation type high-speed camera, made in East Germany, was used to record the high-speed events in various kinds of technical investigations and necessary results have been ob-tained. 1. Measurement of flow velocity on the overflow surface of high dam. In the design of a key water control project with high head, it is extremely necessary to determinate various characteristics of flow velocity field on the overflow surface of high dam. Since the water flow on the surface of high overflow dam possesses the features of large flow velocity and shallow water depth, therefore it is difficult to use the conventional current meters such as pilot tube, miniature cur-rent meter or electrical measuring methods of non-electrical quantities for studying this problem. Adopting the high-speed photographic method to study analogously the characteristics of flow velocity field on the overflow surface of high dam is a kind of new measuring method. People

  5. Improving the critical speeds of high-speed trains using magnetorheological technology

    Science.gov (United States)

    Sun, Shuaishuai; Deng, Huaxia; Li, Weihua; Du, Haiping; Qing Ni, Yi; Zhang, Jin; Yang, Jian

    2013-11-01

    With the rapid development of high-speed railways, vibration control for maintaining stability, passenger comfort, and safety has become an important area of research. In order to investigate the mechanism of train vibration, the critical speeds of various DOFs with respect to suspension stiffness and damping are first calculated and analyzed based on its dynamic equations. Then, the sensitivity of the critical speed is studied by analyzing the influence of different suspension parameters. On the basis of these analyses, a conclusion is drawn that secondary lateral damping is the most sensitive suspension damper. Subsequently, the secondary lateral dampers are replaced with magnetorheological fluid (MRF) dampers. Finally, a high-speed train model with MRF dampers is simulated by a combined ADAMS and MATLAB simulation and tested in a roller rig test platform to investigate the mechanism of how the MRF damper affects the train’s stability and critical speed. The results show that the semi-active suspension installed with MRF dampers substantially improves the stability and critical speed of the train.

  6. Separation of anthraquinone compounds from the seed of Cassia obtusifolia L. using recycling counter-current chromatography.

    Science.gov (United States)

    Yang, Jianhong; Ye, Haoyu; Lai, Huijun; Li, Shucai; He, Shichao; Zhong, Shijie; Chen, Lijuan; Peng, Aihua

    2012-01-01

    Recycling counter-current chromatography (CCC) together with step-gradient CCC and medium-pressure liquid chromatography (MPLC) was employed to separate nine anthraquinone compounds from Cassia obtusifolia L. in this study. The results showed that recycling CCC is a powerful tool for compounds that are difficult to separate with common elution mode. CCC was the better option for crude material while MPLC had advantage for the final tuning. The combination of recycling CCC and MPLC could simplify the method exploring process in the separation process. The structures of these compounds were identified according to their mass spectra, by (1)H-NMR and compared with standard compounds.

  7. High speed twin roll casting of 6016 strip

    OpenAIRE

    Haga, T.; Ikawa, M; H.Watari; S. Kumai

    2006-01-01

    Purpose: of this paper is to clear the possibility of high speed roll casting of thin aluminum alloy strip. 6016aluminum alloy is used for sheet metal of the automobile. Therefore, casting of 6016 was tried in this study.Castability and characteristics of roll cast 6016 strip were investigated.Design/methodology/approach: was a high speed twin roll caster. The high speed twin roll caster was designedto overcome the low castability of the twin roll caster.Findings: are as below. The 6016 could...

  8. High-speed AFM of human chromosomes in liquid

    Science.gov (United States)

    Picco, L. M.; Dunton, P. G.; Ulcinas, A.; Engledew, D. J.; Hoshi, O.; Ushiki, T.; Miles, M. J.

    2008-09-01

    Further developments of the previously reported high-speed contact-mode AFM are described. The technique is applied to the imaging of human chromosomes at video rate both in air and in water. These are the largest structures to have been imaged with high-speed AFM and the first imaging in liquid to be reported. A possible mechanism that allows such high-speed contact-mode imaging without significant damage to the sample is discussed in the context of the velocity dependence of the measured lateral force on the AFM tip.

  9. Trend on High-speed Power Line Communication Technology

    Science.gov (United States)

    Ogawa, Osamu

    High-speed power line communication (PLC) is useful technology to easily build the communication networks, because construction of new infrastructure is not necessary. In Europe and America, PLC has been used for broadband networks since the beginning of 21th century. In Japan, high-speed PLC was deregulated only indoor usage in 2006. Afterward it has been widely used for home area network, LAN in hotels and school buildings and so on. And recently, PLC is greatly concerned as communication technology for smart grid network. In this paper, the author surveys the high-speed PLC technology and its current status.

  10. AN ANALYSIS METHOD FOR HIGH-SPEED CIRCUIT SYSTEMS

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    A new method for analyzing high-speed circuit systems is presented. The method adds transmission line end currents to the circuit variables of the classical modified nodal approach. Then the matrix equation describing high-speed circuit system can be formulated directly and analyzed conveniently for its normative form. A time-domain analysis method for transmission lines is also introduced. The two methods are combined together to efficiently analyze high-speed circuit systems having general transmission lines. Numerical experiment is presented and the results are compared with that calculated by Hspice.

  11. High speed high dynamic range high accuracy measurement system

    Energy Technology Data Exchange (ETDEWEB)

    Deibele, Craig E.; Curry, Douglas E.; Dickson, Richard W.; Xie, Zaipeng

    2016-11-29

    A measuring system includes an input that emulates a bandpass filter with no signal reflections. A directional coupler connected to the input passes the filtered input to electrically isolated measuring circuits. Each of the measuring circuits includes an amplifier that amplifies the signal through logarithmic functions. The output of the measuring system is an accurate high dynamic range measurement.

  12. FPGA Flash Memory High Speed Data Acquisition

    Science.gov (United States)

    Gonzalez, April

    2013-01-01

    The purpose of this research is to design and implement a VHDL ONFI Controller module for a Modular Instrumentation System. The goal of the Modular Instrumentation System will be to have a low power device that will store data and send the data at a low speed to a processor. The benefit of such a system will give an advantage over other purchased binary IP due to the capability of allowing NASA to re-use and modify the memory controller module. To accomplish the performance criteria of a low power system, an in house auxiliary board (Flash/ADC board), FPGA development kit, debug board, and modular instrumentation board will be jointly used for the data acquisition. The Flash/ADC board contains four, 1 MSPS, input channel signals and an Open NAND Flash memory module with an analog to digital converter. The ADC, data bits, and control line signals from the board are sent to an Microsemi/Actel FPGA development kit for VHDL programming of the flash memory WRITE, READ, READ STATUS, ERASE, and RESET operation waveforms using Libero software. The debug board will be used for verification of the analog input signal and be able to communicate via serial interface with the module instrumentation. The scope of the new controller module was to find and develop an ONFI controller with the debug board layout designed and completed for manufacture. Successful flash memory operation waveform test routines were completed, simulated, and tested to work on the FPGA board. Through connection of the Flash/ADC board with the FPGA, it was found that the device specifications were not being meet with Vdd reaching half of its voltage. Further testing showed that it was the manufactured Flash/ADC board that contained a misalignment with the ONFI memory module traces. The errors proved to be too great to fix in the time limit set for the project.

  13. EXPERIMENTAL INVESTIGATION ON SOUND SPEED PROPAGATING THROUGH HIGH SPEED AERATED FLOW IN OPEN CHANNEL

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    An experiment concerning the sound propaga-tion in aerated open channel flow was designed and conductedin a variable slope chute. The acquisition of sound data wasdone by the hydro-phones installed into the bottom wall of thechute. The data were analyzed and processed by the tape re-corder and a 3562A analyzer. The primary experimetal resultsindicated that the sound speed in aerated flow is varied with the air concentration and highly lower than each of the soundspeed in pure water or air. As released by the derived theoryformula, the minimum sound of 24m/s in aerated flow hap-pened when the air concentration achieved to 50%. This resultshows that the compressibility of high speed aerated flowshould be considered when the air concentration is near to50%. A criterion of compressibility of high speed aerated flowwas also giv. En in this paper.

  14. Effects of High-Speed Power Training on Muscle Performance and Braking Speed in Older Adults

    Directory of Open Access Journals (Sweden)

    Stephen P. Sayers

    2012-01-01

    Full Text Available We examined whether high-speed power training (HSPT improved muscle performance and braking speed using a driving simulator. 72 older adults (22 m, 50 f; age = 70.6 ± 7.3 yrs were randomized to HSPT at 40% one-repetition maximum (1RM (HSPT: n=25; 3 sets of 12–14 repetitions, slow-speed strength training at 80%1RM (SSST: n=25; 3 sets of 8–10 repetitions, or control (CON: n=22; stretching 3 times/week for 12 weeks. Leg press and knee extension peak power, peak power velocity, peak power force/torque, and braking speed were obtained at baseline and 12 weeks. HSPT increased peak power and peak power velocity across a range of external resistances (40–90% 1RM; P<0.05 and improved braking speed (P<0.05. Work was similar between groups, but perceived exertion was lower in HSPT (P<0.05. Thus, the less strenuous HSPT exerted a broader training effect and improved braking speed compared to SSST.

  15. INTELLIGENT TOOL CONDITION MONITORING IN HIGH-SPEED ...

    African Journals Online (AJOL)

    MR PRINCE

    work model has been developed for on-line condition monitoring of tool wear in high-speed ... degraded behaviours in wire electrical dis- ... mathematical models such as regression (Lin et ... an 11 kW Computer Numerical Controlled.

  16. High-Speed Thermal Characterization of Cryogenic Flows Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Luna proposes to continue development on a high-speed fiber optic sensor and readout system for cryogenic temperature measurements in liquid oxygen (LOX) and liquid...

  17. High speed railway track dynamics models, algorithms and applications

    CERN Document Server

    Lei, Xiaoyan

    2017-01-01

    This book systematically summarizes the latest research findings on high-speed railway track dynamics, made by the author and his research team over the past decade. It explores cutting-edge issues concerning the basic theory of high-speed railways, covering the dynamic theories, models, algorithms and engineering applications of the high-speed train and track coupling system. Presenting original concepts, systematic theories and advanced algorithms, the book places great emphasis on the precision and completeness of its content. The chapters are interrelated yet largely self-contained, allowing readers to either read through the book as a whole or focus on specific topics. It also combines theories with practice to effectively introduce readers to the latest research findings and developments in high-speed railway track dynamics. It offers a valuable resource for researchers, postgraduates and engineers in the fields of civil engineering, transportation, highway & railway engineering.

  18. implementation and comparative study of a high speed multimode ...

    African Journals Online (AJOL)

    SUMAN HALDAR, SOUMITA HALDAR CHAKRABORTY, PRADIPTAMAITI, PRATIK KUMAR SINHA, PIJUSH BISWAS, Dr. AMITAVA SINHA

    2016-07-07

    Jul 7, 2016 ... The key feature of the work is reduced power and simple circuitry, without ... Keywords: Digital Communication, Multimode Modulator, High Speed ..... Implementation of Universal Modulator using Co-ordinate Rotation Digital ...

  19. Next Generation Modeling Technology for High Speed Rotorcraft Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Recent R&D associated with designing high speed rotorcraft has been greatly hampered by a lack of test data and confidence in predictions for rotors operating...

  20. CSIR National Laser Centre develops a high speed OCT system

    CSIR Research Space (South Africa)

    Sharma, Ameeth

    2016-11-01

    Full Text Available impact areas and applications include polymer characterisation, surface and thin-film characterisation and biometrics. The National laser Centre has developed a high speed, large area optical coherence tomography (OCT) prototype for fingerprint scanning...

  1. Parallelism and pipelining in high-speed digital simulators

    Science.gov (United States)

    Karplus, W. J.

    1983-01-01

    The attainment of high computing speed as measured by the computational throughput is seen as one of the most challenging requirements. It is noted that high speed is cardinal in several distinct classes of applications. These classes are then discussed; they comprise (1) the real-time simulation of dynamic systems , (2) distributed parameter systems, and (3) mixed lumped and distributed systems. From the 1950s on, the quest for high speed in digital simulators concentrated on overcoming the limitations imposed by the so-called von Neumann bottleneck. Two major architectural approaches have made ig possible to circumvent this bottleneck and attain high speeds. These are pipelining and parallelism. Supercomputers, peripheral array processors, and microcomputer networks are then discussed.

  2. Design of high speed camera based on CMOS technology

    Science.gov (United States)

    Park, Sei-Hun; An, Jun-Sick; Oh, Tae-Seok; Kim, Il-Hwan

    2007-12-01

    The capacity of a high speed camera in taking high speed images has been evaluated using CMOS image sensors. There are 2 types of image sensors, namely, CCD and CMOS sensors. CMOS sensor consumes less power than CCD sensor and can take images more rapidly. High speed camera with built-in CMOS sensor is widely used in vehicle crash tests and airbag controls, golf training aids, and in bullet direction measurement in the military. The High Speed Camera System made in this study has the following components: CMOS image sensor that can take about 500 frames per second at a resolution of 1280*1024; FPGA and DDR2 memory that control the image sensor and save images; Camera Link Module that transmits saved data to PC; and RS-422 communication function that enables control of the camera from a PC.

  3. Supersonic stall flutter of high-speed fans

    Science.gov (United States)

    Adamczyk, J. J.; Stevans, W.; Jutras, R.

    1981-01-01

    An analytical model is proposed for predicting the onset of supersonic stall bending flutter in high-speed rotors. The analysis is based on a modified two-dimensional, compressible, unsteady actuator disk theory. The stability boundary predicted by the analysis is shown to be in good agreement with the measured boundary of a high speed fan. The prediction that the flutter mode would be a forward traveling wave sensitive to wheel speed and aerodynamic loading is confirmed by experimental measurements. In addition, the analysis shows that reduced frequency and dynamic head also play a significant role in establishing the supersonic stall bending flutter boundary of an unshrouded fan.

  4. Application of Beyond Bound Decoding for High Speed Optical Communications

    DEFF Research Database (Denmark)

    Li, Bomin; Larsen, Knud J.; Vegas Olmos, Juan José;

    2013-01-01

    This paper studies the application of beyond bound decoding method for high speed optical communications. This hard-decision decoding method outperforms traditional minimum distance decoding method, with a total net coding gain of 10.36 dB.......This paper studies the application of beyond bound decoding method for high speed optical communications. This hard-decision decoding method outperforms traditional minimum distance decoding method, with a total net coding gain of 10.36 dB....

  5. A Multiprocessor Communication Architecture For High Speed Networks

    CERN Document Server

    S, Iyengar; Roy, A A; Sanyal, S; Singhi, N M; Feng, Wu Geng

    2010-01-01

    Over the years, communication speed of networks has increased from a few Kbps to several Mbps, as also the bandwidth demand, Communication Protocols, however have not improved to that extent. With the advent of Wavelength Division Multiplexing (WDM), it is now possible to "tune" protocols to current and future demands. The purpose of this paper is to evolve a High Speed Network architecture, which will cater to the needs of bandwidth-consuming applications, such as voice, video and high definition image transmission.

  6. High-speed optical signal processing using time lenses

    DEFF Research Database (Denmark)

    Galili, Michael; Hu, Hao; Guan, Pengyu;

    2015-01-01

    This paper will discuss time lenses and their broad range of applications. A number of recent demonstrations of complex high-speed optical signal processing using time lenses will be outlined with focus on the operating principle.......This paper will discuss time lenses and their broad range of applications. A number of recent demonstrations of complex high-speed optical signal processing using time lenses will be outlined with focus on the operating principle....

  7. Preparative Isolation of Seven Diterpenoid Alkaloids from Aconitum coreanum by pH-Zone-Refining Counter-Current Chromatography

    Directory of Open Access Journals (Sweden)

    Xueyong Wang

    2014-08-01

    Full Text Available The aim of this paper was to seek an efficient method to preparative separation of alkaloid compounds from Aconitum coreanum (Guanbaifu, a well-known traditional Chinese medicinal plant for heart disease. Seven alkaloid compounds were successfully purified by pH-zone-refining counter-current chromatography with two-phase solvent system of petroleum ether–ethyl acetate–methanol–water (5:5:1:9, v/v/v/v, 10 mM triethylamine in upper phase and 10 mM hydrochloric acid in lower phase. From 3.5 g of crude extract, 356 mg of Guanfu base I, 578 mg of Guanfu base A, 74 mg of atisine, 94 mg of Guanfu base F, 423 mg of Guanfu base G, 67 mg of Guanfu base R and 154 mg of Guanfu base P were obtained with the purity of 96.40%, 97.2%, 97.5%, 98.1%, 98.9%, 98.3% and 98.4%. Their chemical structures were identified by TOF-MS and 1H-NMR. This study indicated that pH-zone-refining counter-current chromatography was an efficient method for separating the kind of alkaloids with low absorbance values.

  8. Study of rare earth separation by counter current electromigration; Estudo da separacao de terras raras por eletromigracao em contra corrente

    Energy Technology Data Exchange (ETDEWEB)

    Correa, Sergio Machado

    1995-08-01

    The counter current electromigration (CCEM) is an electrophoretic technique where the charged species migrate on an electrical field toward an electrolytic flux. Usually this electrolyte is a complexing agent and is necessary to increase the small differences between the species mobilities. A new column was developed, all made of acrylic, in a cylindrical shape. A set of experiments was carried out with the species Na{sup +}/K{sup +}, K{sup +}/Sm{sup +3}, K{sup +}/Eu{sup +3} and K{sup +}/Sm{sup +3}/Eu{sup +3} using the {alpha}-hydrox i-isobutyric acid o,01 M as the counter current electrolytic flux. From a synthetic mixture of 90% of samarium and 10% of europium was obtained the samarium ion in a purity better than 99,9% where the concentration of Eu was determined by the polarography technique. The potassium ion was used as a leading electrolyte. It was also measured the mobilities of the involved species in the {alpha}-HIBA medium. Two models are proposed, a stationary model and a dynamic one. A simulator of a simplified stationary model, prepared in FORTRAN language, was developed and tested toward experimental results. (author)

  9. High Speed Frame Synchronization and Viterbi Decoding

    DEFF Research Database (Denmark)

    Paaske, Erik; Justesen, Jørn; Larsen, Knud J.

    1996-01-01

    The purpose of Phase 1 of the study is to describe the system structure and algorithms in sufficient detail to allow drawing the high level architecture of units containing frame synchronization and Viterbi decoding. The systems we consider are high data rate space communication systems. Also......, the systems use some form of QPSK modulation and transmit data in frames separated by a sync marker and protected by error-correcting codes. We first give a survey of trends within the area of space modulation systems. We then discuss and define the interfaces and operating modes of the relevant system...... components. Node synchronization performed within a Viterbi decoder is discussed, and algorithms for frame synchronization are described and analyzed. We present a list of system configurations that we find potentially useful. Further, the high level architecture of units that contain frame synchronization...

  10. Flat belt continuously variable high speed drive. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Kumm, E.L.

    1992-02-01

    A study was undertaken at Kumm Industries funded by DOE in the NBS/DOE Energy-Related Inventions Program starting in August 1990 to design, construct and test a novel very high speed flat belt drive. The test arrangement as shown in Figure 1 consists of a multiple belt-pulley configuration that transmits power from a low speed (2000--4000 RPM) input to a small pulley ``turbine`` (27,000 to 55,000 RPM) and then to the low speed output variable radius pulley (2000--5000 RPM) via a special self-active tensioner. Transmitting 25 HP to and from the ``turbine`` corresponds to obtaining 50 HP in one direction only in a possible turbo compounded engine application. The high speed of the ``turbine`` belts, i.e. 100 meters/sec. at 55,000 RPM, while transferring substantial power is a new much higher operating regime for belts. The study showed that the available belts gave overall test rig efficiencies somewhat above 80% for the higher speeds (50,000 RPM) and higher powers (corresponding to above 90% in the turbocompound application) and a significantly better efficiencies at slightly lower speeds. The tests revealed a number of improved approaches in the design of such high speed drives. It appears that there is considerable possibility for further improvement and application of such equipment.

  11. Analysis of external noise spectrum of high-speed railway

    Institute of Scientific and Technical Information of China (English)

    邓永权; 肖新标; 何宾; 金学松

    2014-01-01

    A schematic to make the spectra of the exterior noise of high speed railway was put forward. The exterior noise spectrum was defined based on the characteristics of the high-speed train exterior noise. Its characteristics considered here include identifying the exterior main sources and their locations, their frequency components including the Doppler effect due to the noise sources moving at high speed, the sound field intensity around the train in high-speed operation, the sound radiation path out of the train, and the pressure level and frequency components of the noise at the measuring points specified by the International Organization for Standardization(ISO). The characteristics of the high-speed train exterior noise of the high speed railways in operation were introduced. The advanced measuring systems and their principles for clearly indentifying the exterior noise sources were discussed in detail. Based on the concerned noise results measured at sites, a prediction model was developed to calculate the sound level and the characteristics of the exterior noise at any point where it is difficult to measure and to help to make the exterior noise spectrums. This model was also verified with the test results. The verification shows that there is a good agreement between the theoretical and experimental results.

  12. High-speed precision motion control

    CERN Document Server

    Yamaguchi, Takashi; Pang, Chee Khiang

    2011-01-01

    Written for researchers and postgraduate students in Control Engineering, as well as professionals in the Hard Disk Drive industry, this book discusses high-precision and fast servo controls in Hard Disk Drives (HDDs). The editors present a number of control algorithms that enable fast seeking and high precision positioning, and propose problems from commercial products, making the book valuable to researchers in HDDs. Each chapter is self contained, and progresses from concept to technique, present application examples that can be used within automotive, aerospace, aeronautical, and manufactu

  13. High speed multispectral fluorescence lifetime imaging

    NARCIS (Netherlands)

    Fereidouni, F.; Reitsma, K.; Gerritsen, H.C.

    2013-01-01

    We report a spectrally resolved fluorescence lifetime imaging system based on time gated single photon detection with a fixed gate width of 200 ps and 7 spectral channels. Time gated systems can operate at high count rates but usually have large gate widths and sample only part of the fluorescence d

  14. High-speed photography of high-resolution moire patterns

    Science.gov (United States)

    Whitworth, Martin B.; Huntley, Jonathan M.; Field, John E.

    1991-04-01

    The techniques of high resolution moire photography and high speed photography have been combined to allow measurement of the in-plane components of a transient displacement field with microsecond time resolution. Specimen gratings are prepared as casts in a thin layer of epoxy resin on the surface of a specimen. These are illuminated with a flash tube and imaged onto a reference grating with a specially modified camera lens, which incorporates a slotted mask in the aperture plane. For specimen gratings of 75 lines mm1, this selects the +1 and -1 order diffracted beams, thus doubling the effective grating frequency to 150 lines mm1. The resulting real-time moire fringes are recorded with a Hadland 792 image converter camera (Imacon) at an inter-frame time of 2-5ts. The images are digitised and an automatic fringe analysis technique based on the 2-D Fourier transform method is used to extract the displacement information. The technique is illustrated by the results of an investigation into the transient deformation of composite disc specimens, impacted with rectangular metal sliders fired from a gas gun.

  15. High Speed Frame Synchronization and Viterbi Decoding

    DEFF Research Database (Denmark)

    Paaske, Erik; Justesen, Jørn; Larsen, Knud J.

    1998-01-01

    The study has been divided into two phases. The purpose of Phase 1 of the study was to describe the system structure and algorithms in sufficient detail to allow drawing the high level architecture of units containing frame synchronization and Viterbi decoding. After selection of which specific...... separated by a sync marker and protected by error-correcting codes. We first give a survey of trends within the area of space modulation systems. We then discuss and define the interfaces and operating modes of the relevant system components. We present a list of system configurations that we find...... potentially useful.Algorithms for frame synchronization are described and analyzed. Further, the high level architecture of units that contain frame synchronization and various other functions needed in a complete system is presented. Two such units are described, one for placement before the Viterbi decoder...

  16. High-speed quantum networking by ship

    Science.gov (United States)

    Devitt, Simon J.; Greentree, Andrew D.; Stephens, Ashley M.; van Meter, Rodney

    2016-11-01

    Networked entanglement is an essential component for a plethora of quantum computation and communication protocols. Direct transmission of quantum signals over long distances is prevented by fibre attenuation and the no-cloning theorem, motivating the development of quantum repeaters, designed to purify entanglement, extending its range. Quantum repeaters have been demonstrated over short distances, but error-corrected, global repeater networks with high bandwidth require new technology. Here we show that error corrected quantum memories installed in cargo containers and carried by ship can provide a exible connection between local networks, enabling low-latency, high-fidelity quantum communication across global distances at higher bandwidths than previously proposed. With demonstrations of technology with sufficient fidelity to enable topological error-correction, implementation of the quantum memories is within reach, and bandwidth increases with improvements in fabrication. Our approach to quantum networking avoids technological restrictions of repeater deployment, providing an alternate path to a worldwide Quantum Internet.

  17. High-speed quantum networking by ship.

    Science.gov (United States)

    Devitt, Simon J; Greentree, Andrew D; Stephens, Ashley M; Van Meter, Rodney

    2016-11-02

    Networked entanglement is an essential component for a plethora of quantum computation and communication protocols. Direct transmission of quantum signals over long distances is prevented by fibre attenuation and the no-cloning theorem, motivating the development of quantum repeaters, designed to purify entanglement, extending its range. Quantum repeaters have been demonstrated over short distances, but error-corrected, global repeater networks with high bandwidth require new technology. Here we show that error corrected quantum memories installed in cargo containers and carried by ship can provide a exible connection between local networks, enabling low-latency, high-fidelity quantum communication across global distances at higher bandwidths than previously proposed. With demonstrations of technology with sufficient fidelity to enable topological error-correction, implementation of the quantum memories is within reach, and bandwidth increases with improvements in fabrication. Our approach to quantum networking avoids technological restrictions of repeater deployment, providing an alternate path to a worldwide Quantum Internet.

  18. High-speed cineradiography using electronic imaging

    Science.gov (United States)

    Lucero, Jacob P.; Fry, David A.; Gaskill, William E.; Henderson, R. L.; Crawford, Ted R.; Carey, N. E.

    1993-01-01

    The Los Alamos National Laboratory has constructed and is now operating a cineradiography system for imaging and evaluation of ballistic interaction events at the 1200 meter range of the Terminal Effects Research and Analysis (TERA) Group at the New Mexico Institute of Mining and Technology. Cineradiography is part of a complete firing, tracking, and analysis system at the range. The cine system consists of flash x-ray sources illuminating a one-half meter by two meter fast phosphor screen which is viewed by gated-intensified high resolution still video cameras via turning mirrors. The entire system is armored to protect against events containing up to 13.5 kg of high explosive. Digital images are available for immediate display and processing. The system is capable of frame rates up to 105/sec for up to five total images.

  19. High speed cineradiography using electronic imaging

    Science.gov (United States)

    Lucero, J. P.; Fry, D. A.; Gaskill, W. E.; Henderson, R. L.; Crawford, T. R.; Carey, N. E.

    1992-12-01

    The Los Alamos National Laboratory has constructed and is now operating a cineradiography system for imaging and evaluation of ballistic interaction events at the 1200 meter range of the Terminal Effects Research and Analysis (TERA) Group at the New Mexico Institute of Mining and Technology. Cineradiography is part of a complete firing, tracking, and analysis system at the range. The cine system consists of flash x-ray sources illuminating a one-half meter by two meter fast phosphor screen which is viewed by gated-intensified high resolution still video cameras via turning mirrors. The entire system is armored to protect against events containing up to 13.5 kg of high explosive. Digital images are available for immediate display and processing. The system is capable of frame rates up to 10(exp 5)/sec for up to five total images.

  20. High Speed Blood and Transfusion Equipment

    Science.gov (United States)

    2013-10-14

    used to calculate percent hemolysis of red blood cells. Plasma Free Hemoglobin Assay - pRBCs samples were assayed for plasma free hemoglobin (PFH...resulting in high temperatures gradients that preludes blood hemolysis if fluid flow stops. • The solenoid valve has been replaced with a valve of a more...pRBCs to test efficacy. Both pre and post cartridge blood samples were evaluated to determine if any damage may have occurred to blood cells. The

  1. High-speed integrated electroabsorption modulators

    Science.gov (United States)

    Johnson, John E.; Morton, Paul A.; Park, Yong-Kwan; Ketelsen, Leonard J. P.; Grenko, J. A.; Miller, Thomas J.; Sputz, Sharon K.; Tanbun-Ek, Tawee; Vandenberg, J. M.; Yadvish, R. D.; Fullowan, Thomas R.; Sciortino, Paul F., Jr.; Sergent, A. M.; Tsang, Won-Tien

    1997-04-01

    The explosive growth in internet, multimedia and wireless traffic in recent years is rapidly exhausting capacity in public networks worldwide, forcing network service providers to aggressively install new lines and upgrade old ones. Fortunately, technological breakthroughs in the areas of erbium-doped fiber amplifiers (EDFA's), passive wavelength demultiplexers and low chirp sources have made all-optical dense wavelength-division multiplexed (WDM) systems a cost- effective way to utilize the vast bandwidth already available in the embedded fiber plant. WDM systems offer additional operational advantages, including high ultimate capacity, bit-rate transparency, flexible growth strategies, and the potential to use all-optical wavelength routing in future broadband network architectures. Commercial WDM systems operating at the OC-48 (2.5 Gbit/s) line rate are now available, and OC-192 (10 Gbit/s) terminal equipment which is under development will further enhance the capacity of these systems. One of the keys to viable WDM systems is the availability of inexpensive low-chirp optical transmitters. By taking advantage of photonic integrated circuit technology, it is possible to produce monolithically integrated DFB laser/EA modulators (EML's) with low chirp, low drive voltage and high extinction ratio, in a single compact package. In this talk we discuss the operating characteristics of these devices and their relationship to WDM system performance.

  2. Giga bit per second Differential Scheme for High Speed Interconnect

    Directory of Open Access Journals (Sweden)

    Mandeep Singh Narula

    2012-02-01

    Full Text Available The performance of many digital systems today is limited by the interconnection bandwidth between chips. Although the processing performance of a single chip has increased dramatically since the inception of the integrated circuit technology, the communication bandwidth between chips has not enjoyed as much benefit. Most CMOS chips, when communicating off-chip, drive un terminated lines with full-swing CMOS drivers. Such full-swing CMOS interconnect ring-up the line, and hence has a bandwidth that is limited by the length of the line rather than the performance of the semiconductor technology. Thus, as VLSI technology scales, the pin bandwidth does not improve with the technology, but rather remains limited by board and cable geometry, making off-chip bandwidth an even more critical bottleneck. In order to increase the I/O Bandwidth, some efficient high speed signaling standard must be used which considers the line termination, signal integrity, power dissipation, noise immunity etc In this work, a transmitter has been developed for high speed off chip communication. It consists of low speed input buffer, serializer which converts parallel input data into serial data and a current mode driver which converts the voltage mode input signals into current over the transmission line. Output of 32 low speed input buffers is fed to two serializer, each serializer converting 16 bit parallel data into serial data stream. Output of two serializers is fed to LVDS current mode driver. The serial link technique used in this work is the time division multiplex (TDM and point-to-point technique. It means that the low-speed parallel signals are transferred to the high-speed serial signal at the transmitter end and the high-speed serial signal is transferred to the low-speed parallel signals at the receiver end. Serial link is the design of choice in any application where the cost of the communication channel is high and duplicating the links in large numbers is

  3. Giga bit per second Differential Scheme for High Speed Interconnect

    Directory of Open Access Journals (Sweden)

    Mandeep Singh Narula

    2012-03-01

    Full Text Available The performance of many digital systems today is limited by the interconnection bandwidth between chips. Although the processing performance of a single chip has increased dramatically since the inception of the integrated circuit technology, the communication bandwidth between chips has not enjoyed as much benefit. Most CMOS chips, when communicating off-chip, drive unterminated lines with full-swing CMOS drivers. Such full-swing CMOS interconnect ring-up the line, and hence has a bandwidth that is limited by the length of the line rather than the performance of the semiconductor technology. Thus, as VLSI technology scales, the pin bandwidth does not improve with the technology, but rather remains limited by board and cable geometry, making off-chip bandwidth an even more critical bottleneck. In order to increase the I/O Bandwidth, some efficient high speed signaling standard must be used which considers the line termination, signal integrity, power dissipation, noise immunity etc In this work, a transmitter has been developed for high speed offchip communication. It consists of low speed input buffer, serializer which converts parallel input data into serial data and a current mode driver which converts the voltage mode input signals into current over the transmission line. Output of 32 low speed input buffers is fed to two serializer, each serializer converting 16 bit parallel data into serial data stream. Output of two serializers is fed to LVDS current mode driver. The serial link technique used in this work is the time division multiplex (TDM and point-to-point technique. It means that the low-speed parallel signals are transferred to the high-speed serial signal at the transmitter end and the high-speed serial signal is transferred to the low-speed parallel signals at the receiver end. Serial link is the design of choice in any application where the cost of the communication channel is high and duplicating the links in large numbers is

  4. High-speed analog-to-digital conversion

    CERN Document Server

    Demler, Michael J

    1991-01-01

    This book covers the theory and applications of high-speed analog-to-digital conversion. An analog-to-digital converter takes real-world inputs (such as visual images, temperature readings, and rates of speed) and transforms them into digital form for processing by computer. This book discusses the design and uses of such circuits, with particular emphasis on improving the speed of the conversion process and the accuracy of its output--how well the output is a corresponding digital representation of the output*b1input signal. As computers become increasingly interfaced to the outside world, ""

  5. High speed inspection of ceramic fuels

    Energy Technology Data Exchange (ETDEWEB)

    McLemore, D. R.

    1979-03-01

    A fuel pellet inspection system is under development and evaluation for use in the High Performance Fuel Laboratory (HPFL) at Richland, Washington. A major operation in this process is the gaging of fuel pellets for dimensions (length and diameter), surface flaws and weight. The system is modularly designed to simplify maintenance operations thereby reducing personnel exposure. The inspection system is divided into two parts: mechanical and electronic. The mechanical portion consists of a pellet handling system; inspection stations for measuring length, diameter, weight and surface flaws; and a glovebox-like containment which isolates Special Nuclear Material (SNM) from the surrounding environment. The electronic portion is a dedicated minicomputer for process control and a supervisory computer system which will be located in a centralized control center and be shared with other development activities in the HPFL.

  6. High Speed Imaging of Diesel Fuel Sprays

    Science.gov (United States)

    Jackson, Ja'kira; Bittle, Joshua

    2016-11-01

    Fuel sprays primarily serve as methods for fuel distribution, fuel/air mixing, and atomization. In this research, a constant pressure flow rig vessel is being tested at various pressures and temperatures using n-heptane. The experiment requires two imaging techniques: color Schlieren and Mie-scatter. Schlieren captures density gradients in a spray which includes both liquid and vapor phases while Mie-scatter is only sensitive to the liquid phase of the fuel spray. Essentially, studies are mainly focused on extracting the liquid boundary from the Schlieren to possibly eliminate the need for acquiring the Mie-Scatter technique. Four test conditions (combination of low and high pressure and temperatures) are used in the application to attempt to find the liquid boundary independent of the Mie-scatter technique. In this pursuit the following methods were used: a color threshold, a value threshold, and the time variation in color. All methods provided some indication of the liquid region but none were able to capture the full liquid boundary as obtained by the Mie-scatter results. Funding from NSF REU site Grant EEC 1358991 is greatly appreciated.

  7. SPH simulations of high-speed collisions

    Science.gov (United States)

    Rozehnal, Jakub; Broz, Miroslav

    2016-10-01

    Our work is devoted to a comparison of: i) asteroid-asteroid collisions occurring at lower velocities (about 5 km/s in the Main Belt), and ii) mutual collisions of asteroids and cometary nuclei usually occurring at significantly higher relative velocities (> 10 km/s).We focus on differences in the propagation of the shock wave, ejection of the fragments and possible differences in the resultingsize-frequency distributions of synthetic asteroid families. We also discuss scaling with respect to the "nominal" target diameter D = 100 km, projectile velocity 3-7 km/s, for which a number of simulations were done so far (Durda et al. 2007, Benavidez et al. 2012).In the latter case of asteroid-comet collisions, we simulate the impacts of brittle or pre-damaged impactors onto solid monolithic targets at high velocities, ranging from 10 to 15 km/s. The purpose of this numerical experiment is to better understand impact processes shaping the early Solar System, namely the primordial asteroid belt during during the (late) heavy bombardment (as a continuation of Broz et al. 2013).For all hydrodynamical simulations we use a smoothed-particle hydrodynamics method (SPH), namely the lagrangian SPH3D code (Benz & Asphaug 1994, 1995). The gravitational interactions between fragments (re-accumulation) is simulated with the Pkdgrav tree-code (Richardson et al. 2000).

  8. ALICE HLT high speed tracking on GPU

    CERN Document Server

    Gorbunov, Sergey; Aamodt, Kenneth; Alt, Torsten; Appelshauser, Harald; Arend, Andreas; Bach, Matthias; Becker, Bruce; Bottger, Stefan; Breitner, Timo; Busching, Henner; Chattopadhyay, Sukalyan; Cleymans, Jean; Cicalo, Corrado; Das, Indranil; Djuvsland, Oystein; Engel, Heiko; Erdal, Hege Austrheim; Fearick, Roger; Haaland, Oystein Senneset; Hille, Per Thomas; Kalcher, Sebastian; Kanaki, Kalliopi; Kebschull, Udo Wolfgang; Kisel, Ivan; Kretz, Matthias; Lara, Camillo; Lindal, Sven; Lindenstruth, Volker; Masoodi, Arshad Ahmad; Ovrebekk, Gaute; Panse, Ralf; Peschek, Jorg; Ploskon, Mateusz; Pocheptsov, Timur; Ram, Dinesh; Rascanu, Theodor; Richter, Matthias; Rohrich, Dieter; Ronchetti, Federico; Skaali, Bernhard; Smorholm, Olav; Stokkevag, Camilla; Steinbeck, Timm Morten; Szostak, Artur; Thader, Jochen; Tveter, Trine; Ullaland, Kjetil; Vilakazi, Zeblon; Weis, Robert; Yin, Zhong-Bao; Zelnicek, Pierre

    2011-01-01

    The on-line event reconstruction in ALICE is performed by the High Level Trigger, which should process up to 2000 events per second in proton-proton collisions and up to 300 central events per second in heavy-ion collisions, corresponding to an inp ut data stream of 30 GB/s. In order to fulfill the time requirements, a fast on-line tracker has been developed. The algorithm combines a Cellular Automaton method being used for a fast pattern recognition and the Kalman Filter method for fitting of found trajectories and for the final track selection. The tracker was adapted to run on Graphics Processing Units (GPU) using the NVIDIA Compute Unified Device Architecture (CUDA) framework. The implementation of the algorithm had to be adjusted at many points to allow for an efficient usage of the graphics cards. In particular, achieving a good overall workload for many processor cores, efficient transfer to and from the GPU, as well as optimized utilization of the different memories the GPU offers turned out to be cri...

  9. Low Speed and High Speed Correlation of SMART Active Flap Rotor Loads

    Science.gov (United States)

    Kottapalli, Sesi B. R.

    2010-01-01

    Measured, open loop and closed loop data from the SMART rotor test in the NASA Ames 40- by 80- Foot Wind Tunnel are compared with CAMRAD II calculations. One open loop high-speed case and four closed loop cases are considered. The closed loop cases include three high-speed cases and one low-speed case. Two of these high-speed cases include a 2 deg flap deflection at 5P case and a test maximum-airspeed case. This study follows a recent, open loop correlation effort that used a simple correction factor for the airfoil pitching moment Mach number. Compared to the earlier effort, the current open loop study considers more fundamental corrections based on advancing blade aerodynamic conditions. The airfoil tables themselves have been studied. Selected modifications to the HH-06 section flap airfoil pitching moment table are implemented. For the closed loop condition, the effect of the flap actuator is modeled by increased flap hinge stiffness. Overall, the open loop correlation is reasonable, thus confirming the basic correctness of the current semi-empirical modifications; the closed loop correlation is also reasonable considering that the current flap model is a first generation model. Detailed correlation results are given in the paper.

  10. Quality of service on high-speed data networks

    Science.gov (United States)

    Barbero, Ezio; Antonelli, Ferruccio

    1995-02-01

    Since the beginning of this century the issue of `quality' has been gaining increasing importance in a number of fields of human activities. For telecommunication services, too, the quality perceived by customers has been taken into account early on as an issue of strategic importance. Whilst for telephony the Quality of Service (QoS) has been already investigated and identified in terms of parameters and related test methodology, the situation for high speed data services (i.e. CBDS/SMDS, Frame Relay, etc.), provided by means of high speed network based on Asynchronous Transfer Moe (ATM) or Metropolitan Area Network technologies, can still be considered `under study'. There is a death of experience not only in terms of measurement instruments and procedures, but also in terms of knowledge of the relationship between the QoS provided at a network level and the quality perceived by the user on his or her terminal. The complexity of the equipment involved in setting up an end-to-end solution based on high speed data communications makes the problems of knowledge and supply of quality very hard to solve. Starting from the experience gained in carrying out high- speed network field trials based on Metropolitan Area Networks and, more recently, on ATM technology, the paper mainly deals with the problem of defining, measuring and then offering a specific QoS. First, the issue of what the user expects from the `high-speed network' is addressed. This analysis is carried out trying to gather what is peculiar to high-speed data communications from the user standpoint. Next, the focus is on how to cope with the requirements due to users' expectations, while carefully considering the basic principles of quality. Finally, a solution is proposed, starting from the experience gained from high speed networks installed in Italy.

  11. Recent progress on high-speed optical transmission

    Directory of Open Access Journals (Sweden)

    Jianjun Yu

    2016-05-01

    Full Text Available The recently reported high spectral efficiency (SE and high-baud-rate signal transmission are all based on digital coherent optical communications and digital signal processing (DSP. DSP simplifies the reception of advanced modulation formats and also enables the major electrical and optical impairments to be processed and compensated in the digital domain, at the transmitter or receiver side. In this paper, we summarize the research progress on high-speed signal generation and detection and also show the progress on DSP for high-speed signal detection. We also report the latest progress on multi-core and multi-mode multiplexing.

  12. Ultra-high-speed spectropolarimeter based on photoelastic modulator.

    Science.gov (United States)

    Zhang, Rui; Li, Kewu; Chen, Yuanyuan; Wen, Tingdun; Zhang, Minjuan; Wang, Yaoli; Xue, Peng; Wang, Zhibin

    2016-10-20

    Combined with the advantages of photoelastic modulator (PEM) ultra-high-speed modulation, this paper presents a method of ultra-high-speed spectropolarimeter based on PEM. The method provides the necessary measuring instruments for ultra-high-speed polarization spectroscopy. The main idea of this method is that an intensity modulator consisting of two retarders is placed before the PEM. The incident light under test goes through two retarders to the PEM. The interference signals are obtained by the PEM modulation. The different Stokes element interference signals are modulated by the PEM at different positions of the optical path difference. This method realizes the separation of Stokes element interference signals. The interference signals corresponding to each element are extracted, and the incident light Stokes element spectra can be obtained from the Fourier transforms of the interference signals. The modulation frequency of the PEM is high (tens to hundreds of kilohertz), so this method can realize ultra-high-speed full polarization spectroscopy. A prototype ultra-high-speed spectropolarimeter based on PEM was designed and tested. If the single-sided Fourier transformation is used, the single-sided interferogram scanning time is approximately 5 μs (i.e., the prototype is capable of scanning 20,000 interferograms per second). Polychromatic light polarization spectroscopy is measured by the prototype. The experimental results show that the average error of the prototype is less than 0.03.

  13. Assessment of rural soundscapes with high-speed train noise.

    Science.gov (United States)

    Lee, Pyoung Jik; Hong, Joo Young; Jeon, Jin Yong

    2014-06-01

    In the present study, rural soundscapes with high-speed train noise were assessed through laboratory experiments. A total of ten sites with varying landscape metrics were chosen for audio-visual recording. The acoustical characteristics of the high-speed train noise were analyzed using various noise level indices. Landscape metrics such as the percentage of natural features (NF) and Shannon's diversity index (SHDI) were adopted to evaluate the landscape features of the ten sites. Laboratory experiments were then performed with 20 well-trained listeners to investigate the perception of high-speed train noise in rural areas. The experiments consisted of three parts: 1) visual-only condition, 2) audio-only condition, and 3) combined audio-visual condition. The results showed that subjects' preference for visual images was significantly related to NF, the number of land types, and the A-weighted equivalent sound pressure level (LAeq). In addition, the visual images significantly influenced the noise annoyance, and LAeq and NF were the dominant factors affecting the annoyance from high-speed train noise in the combined audio-visual condition. In addition, Zwicker's loudness (N) was highly correlated with the annoyance from high-speed train noise in both the audio-only and audio-visual conditions. © 2013.

  14. High speed twin roll caste for aluminum alloy thin strip

    Directory of Open Access Journals (Sweden)

    T. Haga

    2007-09-01

    Full Text Available Purpose: In the present study, effectiveness of a high-speed twin roll caster for recycling aluminum alloy was investigated.Design/methodology/approach: The effects of the high-speed twin roll caster on alleviating the deterioration of mechanical properties by impurities were investigated. Properties of the cast strip were investigated by metalography, a tension test, and a bending test.Findings: A vertical type twin roll caster for strip casting of aluminum alloys was devised. The strip, which was thinner than 3 mm, could be cast at speeds higher than 60 m/min. Features of the twin roll casters are as below. Copper rolls were used and lubricant was not used in order to increase the casting speed. A casting nozzle was used to set the solidification length precisely. Heat transfer between melt and the roll was improved by hydrostatic pressure of the melt. Separating force was very small in order to prevent sticking of the strip to the roll. Low superheat casting was carried out in order to improve microstructure of the strip. In the present study, effectiveness of a high-speed and high-cooling rate twin roll caster of the present study for recycling aluminum alloy was investigated. Fe was added as impurity to 6063 and A356. The roll caster of the present study was useful to decrease the influence of impurity of Fe.Research limitations/implications: A high-speed twin roll caster of vertical type was designed and assembled to cast aluminum alloy thin strip.Originality/value: The results demonstrate that the high-speed twin roll caster can improve the deterioration by impurities.

  15. HDR {sup 192}Ir source speed measurements using a high speed video camera

    Energy Technology Data Exchange (ETDEWEB)

    Fonseca, Gabriel P. [Instituto de Pesquisas Energéticas e Nucleares—IPEN-CNEN/SP, São Paulo 05508-000, Brazil and Department of Radiation Oncology (MAASTRO), GROW School for Oncology and Developmental Biology, Maastricht University Medical Center, Maastricht 6201 BN (Netherlands); Viana, Rodrigo S. S.; Yoriyaz, Hélio [Instituto de Pesquisas Energéticas e Nucleares—IPEN-CNEN/SP, São Paulo 05508-000 (Brazil); Podesta, Mark [Department of Radiation Oncology (MAASTRO), GROW School for Oncology and Developmental Biology, Maastricht University Medical Center, Maastricht 6201 BN (Netherlands); Rubo, Rodrigo A.; Sales, Camila P. de [Hospital das Clínicas da Universidade de São Paulo—HC/FMUSP, São Paulo 05508-000 (Brazil); Reniers, Brigitte [Department of Radiation Oncology - MAASTRO, GROW School for Oncology and Developmental Biology, Maastricht University Medical Center, Maastricht 6201 BN (Netherlands); Research Group NuTeC, CMK, Hasselt University, Agoralaan Gebouw H, Diepenbeek B-3590 (Belgium); Verhaegen, Frank, E-mail: frank.verhaegen@maastro.nl [Department of Radiation Oncology - MAASTRO, GROW School for Oncology and Developmental Biology, Maastricht University Medical Center, Maastricht 6201 BN (Netherlands); Medical Physics Unit, Department of Oncology, McGill University, Montréal, Québec H3G 1A4 (Canada)

    2015-01-15

    Purpose: The dose delivered with a HDR {sup 192}Ir afterloader can be separated into a dwell component, and a transit component resulting from the source movement. The transit component is directly dependent on the source speed profile and it is the goal of this study to measure accurate source speed profiles. Methods: A high speed video camera was used to record the movement of a {sup 192}Ir source (Nucletron, an Elekta company, Stockholm, Sweden) for interdwell distances of 0.25–5 cm with dwell times of 0.1, 1, and 2 s. Transit dose distributions were calculated using a Monte Carlo code simulating the source movement. Results: The source stops at each dwell position oscillating around the desired position for a duration up to (0.026 ± 0.005) s. The source speed profile shows variations between 0 and 81 cm/s with average speed of ∼33 cm/s for most of the interdwell distances. The source stops for up to (0.005 ± 0.001) s at nonprogrammed positions in between two programmed dwell positions. The dwell time correction applied by the manufacturer compensates the transit dose between the dwell positions leading to a maximum overdose of 41 mGy for the considered cases and assuming an air-kerma strength of 48 000 U. The transit dose component is not uniformly distributed leading to over and underdoses, which is within 1.4% for commonly prescribed doses (3–10 Gy). Conclusions: The source maintains its speed even for the short interdwell distances. Dose variations due to the transit dose component are much lower than the prescribed treatment doses for brachytherapy, although transit dose component should be evaluated individually for clinical cases.

  16. Thermal Behavior of High-Speed Helical Gear Trains Investigated

    Science.gov (United States)

    Handschuh, Robert F.

    2003-01-01

    High-speed and heavily loaded gearing are commonplace in the rotorcraft systems employed in helicopter and tiltrotor transmissions. The components are expected to deliver high power from the gas turbine engines to the high-torque, low-speed rotor, reducing the shaft rotational speed in the range of 25:1 to 100:1. These components are designed for high power-to-weight ratios, thus the components are fabricated as light as possible with the best materials and processing to transmit the required torque and carry the resultant loads without compromising the reliability of the drive system. This is a difficult task that is meticulously analyzed and thoroughly tested experimentally prior to being applied on a new or redesigned aircraft.

  17. Review of actuators for high speed active flow control

    Institute of Scientific and Technical Information of China (English)

    WANG Lin; LUO ZhenBing; XIA ZhiXun; LIU Bing; DENG Xiong

    2012-01-01

    Actuators are one of the key points for the development of active flow control technology.Efficient methods of high speed flow control can provide enhanced propulsive efficiency and at the same time enable safe and maneuverable high speed flight.The development of high speed flight technology promotes the emergence of novel and robust actuators.This review introduces the state of the art in the development of actuators that can be used in high speed active flow control.The classification and different operation criteria of the actuators are discussed.The specifications,mechanisms and applications of various popular actuator types including fluidic,mechanical,and plasma actuators are described.Based on the realistic need of high speed flow control and the existing results of actuators,a new actuator design method is proposed.At last,the merits and drawbacks of the actuators are summarized and some suggestions on the development of active flow control technology are put forward.

  18. Ping-Pong Robotics with High-Speed Vision System

    DEFF Research Database (Denmark)

    Li, Hailing; Wu, Haiyan; Lou, Lei

    2012-01-01

    , a multithreshold legmentation algorithm is applied in a stereo-vision running at 150Hz. Based on the estimated 3D ball positions, a novel two-phase trajectory prediction is exploited to determine the hitting position. Benefiting from the high-speed visual feedback, the hitting position and thus the motion planning......The performance of vision-based control is usually limited by the low sampling rate of the visual feedback. We address Ping-Pong robotics as a widely studied example which requires high-speed vision for highly dynamic motion control. In order to detect a flying ball accurately and robustly...

  19. Three-dimensional direct numerical simulations of co/counter-current vertical gas-Liquid annular flows

    Science.gov (United States)

    Farhaoui, Asma; Kahouadji, Lyes; Chergui, Jalel; Juric, Damir; Shin, Seungwon; Craster, Richard; Matar, Omar

    2016-11-01

    We carry out three-dimensional numerical simulations of co/counter current Gas-Liquid annular flows using the parallel code, BLUE, based on a projection method for the resolution of the Navier-Stokes equations and a hybrid Front-Tracking/Level-Set method for the interface advection. Gas-Liquid annular flows and falling films in a pipe are present in a broad range of industrial processes. This configuration consists of an important multiphase flow regime where the liquid occupies the area adjacent to the internal circumference of the pipe and the gas flows in the pipe core. Experimentally, four distinctive flow regimes were identified ('dual-wave', 'thick ripple', 'disturbance wave' and 'regular wave' regimes), that we attempt to simulate. In order to visualize these different regimes, various liquid (water) and gas (air) flow-rates are investigated. EPSRC UK Programme Grant EP/K003976/1.

  20. A Counter-Current Heat-Exchange Reactor for the Thermal Stimulation of Hydrate-Bearing Sediments

    Directory of Open Access Journals (Sweden)

    Manja Luzi-Helbing

    2013-06-01

    Full Text Available Since huge amounts of CH4 are bound in natural gas hydrates occurring at active and passive continental margins and in permafrost regions, the production of natural gas from hydrate-bearing sediments has become of more and more interest. Three different methods to destabilize hydrates and release the CH4 gas are discussed in principle: thermal stimulation, depressurization and chemical stimulation. This study focusses on the thermal stimulation using a counter-current heat-exchange reactor for the in situ combustion of CH4. The principle of in situ combustion as a method for thermal stimulation of hydrate bearing sediments has been introduced and discussed earlier [1,2]. In this study we present the first results of several tests performed in a pilot plant scale using a counter-current heat-exchange reactor. The heat of the flameless, catalytic oxidation of CH4 was used for the decomposition of hydrates in sand within a LArge Reservoir Simulator (LARS. Different catalysts were tested, varying from diverse elements of the platinum group to a universal metal catalyst. The results show differences regarding the conversion rate of CH4 to CO2. The promising results of the latest reactor test, for which LARS was filled with sand and ca. 80% of the pore space was saturated with CH4 hydrate, are also presented in this study. The data analysis showed that about 15% of the CH4 gas released from hydrates would have to be used for the successful dissociation of all hydrates in the sediment using thermal stimulation via in situ combustion.

  1. Research on Aerodynamic Noise Reduction for High-Speed Trains

    Directory of Open Access Journals (Sweden)

    Yadong Zhang

    2016-01-01

    Full Text Available A broadband noise source model based on Lighthill’s acoustic theory was used to perform numerical simulations of the aerodynamic noise sources for a high-speed train. The near-field unsteady flow around a high-speed train was analysed based on a delayed detached-eddy simulation (DDES using the finite volume method with high-order difference schemes. The far-field aerodynamic noise from a high-speed train was predicted using a computational fluid dynamics (CFD/Ffowcs Williams-Hawkings (FW-H acoustic analogy. An analysis of noise reduction methods based on the main noise sources was performed. An aerodynamic noise model for a full-scale high-speed train, including three coaches with six bogies, two inter-coach spacings, two windscreen wipers, and two pantographs, was established. Several low-noise design improvements for the high-speed train were identified, based primarily on the main noise sources; these improvements included the choice of the knuckle-downstream or knuckle-upstream pantograph orientation as well as different pantograph fairing structures, pantograph fairing installation positions, pantograph lifting configurations, inter-coach spacings, and bogie skirt boards. Based on the analysis, we designed a low-noise structure for a full-scale high-speed train with an average sound pressure level (SPL 3.2 dB(A lower than that of the original train. Thus, the noise reduction design goal was achieved. In addition, the accuracy of the aerodynamic noise calculation method was demonstrated via experimental wind tunnel tests.

  2. MARVIN : high speed 3D imaging for seedling classification

    NARCIS (Netherlands)

    Koenderink, N.J.J.P.; Wigham, M.L.I.; Golbach, F.B.T.F.; Otten, G.W.; Gerlich, R.J.H.; Zedde, van de H.J.

    2009-01-01

    The next generation of automated sorting machines for seedlings demands 3D models of the plants to be made at high speed and with high accuracy. In our system the 3D plant model is created based on the information of 24 RGB cameras. Our contribution is an image acquisition technique based on

  3. Improving Jatropha curcas seed protein recovery by using counter current multistage extraction

    NARCIS (Netherlands)

    Lestari, D.; Mulder, W.J.; Sanders, J.P.M.

    2010-01-01

    Jatropha curcas seed press cake contains 23 wt% proteins (dry basis). Due to the toxic compounds in Jatropha, we will use the proteins for non-food applications. Related to non-food applications, an efficient protein extraction to obtain a high protein recovery and high protein concentration with go

  4. Adaptations to speed endurance training in highly trained soccer players

    DEFF Research Database (Denmark)

    Nyberg, Michael Permin; Fiorenza, Matteo; Lund, Anders

    2016-01-01

    PURPOSE: The present study examined whether a period of additional speed endurance training would improve intense intermittent exercise performance in highly trained soccer players during the season and whether the training changed aerobic metabolism and the level of oxidative enzymes in type I...... and II muscle fibers. METHODS: During the last nine weeks of the season, thirteen semi-professional soccer players performed additional speed endurance training sessions consisting of 2-3 sets of 8 - 10 repetitions of 30 m sprints with 10 s of passive recovery (SET). Before and after SET, subjects...... in type I and II fibers did not change. CONCLUSION: In highly trained soccer players, additional speed endurance training is associated with an improved ability to perform repeated high-intensity work. To what extent the training-induced changes in V˙O2 kinetics and mechanical efficiency in type I fibers...

  5. VCA Direct-Drive High Speed and Precision XY Table

    Institute of Scientific and Technical Information of China (English)

    ZHAO Xingyu; FENG Xiaomei; ZHANG Dawei

    2007-01-01

    In order to compensate for the limitation of conventional XY table used in semiconductor integrated circuits(IC) packaging and improve its speed and accuracy, a voice coil actuator (VCA)direct-drive high-speed and precision positioning XY table used in wire bonder was proposed. Also, a novel flexible decoupling mechanism was used in the positioning table, and the small moving mass enabled the positioning table to move at high speed and precision. XY table deformation interference caused by assembly error and instant interference generated by dynamic load moving with high speed and acceleration can be eliminated through the flexible decoupling mechanism. Considering the positioning table as lumped mass spring system, the dynamic equations of the mechanical sys-tem and the VCA were built according to the Newton mechanics principle and electromagnetic theory. Then the electromechanical coupling control model of the system was created through Laplace transform. Based on displacement PID controller, the Icop-locked controlling algorithm of the positioning system was investigated. The dynamic control algorithm effectively improved the system dynamic performance. The precision test of the prototype machine was carried out, and the results val-idated the correctness of the model and the theory. Compared with traditional XY table, the tablehas higher speed, acceleration and positioning accuracy.

  6. Secondary Containment Design for a High Speed Centrifuge

    Energy Technology Data Exchange (ETDEWEB)

    Snyder, K.W.

    1999-03-01

    Secondary containment for high speed rotating machinery, such as a centrifuge, is extremely important for operating personnel safety. Containment techniques can be very costly, ungainly and time consuming to construct. A novel containment concept is introduced which is fabricated out of modular sections of polycarbonate glazed into a Unistrut metal frame. A containment study for a high speed centrifuge is performed which includes the development of parameters for secondary containment design. The Unistrut/polycarbonate shield framing concept is presented including design details and proof testing procedures. The economical fabrication and modularity of the design indicates a usefulness for this shielding system in a wide variety of containment scenarios.

  7. High Speed, Low Power Current Comparators with Hysteresis

    Directory of Open Access Journals (Sweden)

    Neeraj K. Chasta

    2012-02-01

    Full Text Available This paper, presents a novel idea for analog current comparison which compares input signal current and reference currents with high speed, low power and well controlled hysteresis. Proposed circuit is based on current mirror and voltage latching techniques which produces rail to rail output voltage as a result of current comparison. The same design can be extended to a simple current comparator without hysteresis (or very less hysteresis, where comparator gives high accuracy (less than 50nA and speed at the cost of moderate power consumption. The comparators are designed optimally and studied at 180 nm CMOS process technology for a supply voltage of 3V.

  8. High Speed, Low Power Current Comparators with Hysteresis

    Directory of Open Access Journals (Sweden)

    Neeraj K. Chasta

    2012-03-01

    Full Text Available This paper, presents a novel idea for analog current comparison which compares input signal current and reference currents with high speed, low power and well controlled hysteresis. Proposed circuit is based on current mirror and voltage latching techniques which produces rail to rail output voltage as a result of current comparison. The same design can be extended to a simple current comparator without hysteresis (or very less hysteresis, where comparator gives high accuracy (less than 50nA and speed at the cost of moderate power consumption. The comparators are designed optimally and studied at 180nm CMOS process technology for a supply voltage of 3V.

  9. Method for high-speed Manchester encoded optical signal generation

    DEFF Research Database (Denmark)

    Zhang, Jianfeng; Chi, Nan; Holm-Nielsen, Pablo Villanueva

    2004-01-01

    A method for high-speed Manchester encoded optical signal generation is proposed and demonstrated with a specially configured electro-optical modulator. A 10 Gb/s Manchester encoded optical signal was generated, and its bit-error-ratio (BER) performance was evaluated.......A method for high-speed Manchester encoded optical signal generation is proposed and demonstrated with a specially configured electro-optical modulator. A 10 Gb/s Manchester encoded optical signal was generated, and its bit-error-ratio (BER) performance was evaluated....

  10. Necking Point in PET High-speed Fiber Spinning

    Institute of Scientific and Technical Information of China (English)

    王夏琴; 唐志廉

    2001-01-01

    Cross-over method is established to predict necking point for PET high- speed fiber spinning. Even slowly crystallizing polymers such as PET can crystallize on the spinline at sufficiently high spinning speed. The development of rtmning velocity, temperature, crystallinity and theological force is investigated for the take-up velocity over a range of 6 000 - 10 000 m/min. The position of necking point, temperature rise and abrupt increase of crystallinity move closer to the spinneret with the increase of take-up velocity,

  11. High Speed, Low Power Current Comparators with Hysteresis

    CERN Document Server

    Chasta, Neeraj K

    2012-01-01

    This paper, presents a novel idea for analog current comparison which compares input signal current and reference currents with high speed, low power and well controlled hysteresis. Proposed circuit is based on current mirror and voltage latching techniques which produces rail to rail output voltage as a result of current comparison. The same design can be extended to a simple current comparator without hysteresis (or very less hysteresis), where comparator gives high accuracy (less than 50nA) and speed at the cost of moderate power consumption. The comparators are designed optimally and studied at 180nm CMOS process technology for a supply voltage of 3V.

  12. Miniature high speed compressor having embedded permanent magnet motor

    Science.gov (United States)

    Zhou, Lei (Inventor); Zheng, Liping (Inventor); Chow, Louis (Inventor); Kapat, Jayanta S. (Inventor); Wu, Thomas X. (Inventor); Kota, Krishna M. (Inventor); Li, Xiaoyi (Inventor); Acharya, Dipjyoti (Inventor)

    2011-01-01

    A high speed centrifugal compressor for compressing fluids includes a permanent magnet synchronous motor (PMSM) having a hollow shaft, the being supported on its ends by ball bearing supports. A permanent magnet core is embedded inside the shaft. A stator with a winding is located radially outward of the shaft. The PMSM includes a rotor including at least one impeller secured to the shaft or integrated with the shaft as a single piece. The rotor is a high rigidity rotor providing a bending mode speed of at least 100,000 RPM which advantageously permits implementation of relatively low-cost ball bearing supports.

  13. Improvement of die life in high speed injection die casting

    Institute of Scientific and Technical Information of China (English)

    Yasuhiro Arisuda; Akihito Hasuno; Junji Yoshida; Kazunari Tanii

    2008-01-01

    High-speed injection die casting is an efficient manufacturing technology for upgrading aluminum die-cast products. However, deficiencies (such as die damage in eady period) due to larger load on the molding die compared with conventional technology have brought new challenges. In this study, the cause of damage generated in super high-speed injection was investigated by the combination of experimental observation of the dies and CAE simulation (e.g. die temperature analysis, flow analysis and thermal stress analysis). The potential countermeasures to solve the above problems were also proposed.

  14. Improvement of die life in high speed injection die casting

    Directory of Open Access Journals (Sweden)

    Akihito Hasuno

    2008-11-01

    Full Text Available High-speed injection die casting is an effi cient manufacturing technology for upgrading aluminum die-cast products. However, defi ciencies (such as die damage in early period due to larger load on the molding die compared with conventional technology have brought new challenges. In this study, the cause of damage generated in super high-speed injection was investigated by the combination of experimental observation of the dies and CAE simulation (e.g. die emperature analysis, fl ow analysis and thermal stress analysis. The potential countermeasures to solve the above problems were also proposed.

  15. Compact Models and Measurement Techniques for High-Speed Interconnects

    CERN Document Server

    Sharma, Rohit

    2012-01-01

    Compact Models and Measurement Techniques for High-Speed Interconnects provides detailed analysis of issues related to high-speed interconnects from the perspective of modeling approaches and measurement techniques. Particular focus is laid on the unified approach (variational method combined with the transverse transmission line technique) to develop efficient compact models for planar interconnects. This book will give a qualitative summary of the various reported modeling techniques and approaches and will help researchers and graduate students with deeper insights into interconnect models in particular and interconnect in general. Time domain and frequency domain measurement techniques and simulation methodology are also explained in this book.

  16. Magneto-optical system for high speed real time imaging

    Science.gov (United States)

    Baziljevich, M.; Barness, D.; Sinvani, M.; Perel, E.; Shaulov, A.; Yeshurun, Y.

    2012-08-01

    A new magneto-optical system has been developed to expand the range of high speed real time magneto-optical imaging. A special source for the external magnetic field has also been designed, using a pump solenoid to rapidly excite the field coil. Together with careful modifications of the cryostat, to reduce eddy currents, ramping rates reaching 3000 T/s have been achieved. Using a powerful laser as the light source, a custom designed optical assembly, and a high speed digital camera, real time imaging rates up to 30 000 frames per seconds have been demonstrated.

  17. Microstructural development and mechanical properties of high speed steels

    Energy Technology Data Exchange (ETDEWEB)

    Rubio, A.; Gordo, E.; Velasco, F.; Candela, N.; Torralba, J.M. [Dept. de Ciencia de Materiales e Ing. Metalurgica, Univ. Carlos III de Madrid (Spain)

    2001-07-01

    A study was made of the sintering of high speed steel (HSS), M3/2, with different percentage additions - (0%, 2.5%, 5% and 8% by vol.) - of niobium carbide. The mixture was ground in a high speed ball mill to ensure smooth distribution and a material free from agglomerates. All the mixtures were sintered at temperatures above that of solidus, higher temperatures being required as the proportion of the niobium carbide was increased. The variation of the density and hardness were measured, as well as the evolution of the microstructure and the composition of the carbides with the sintering temperature. (orig.)

  18. Plasma-Assisted Chemistry in High-Speed Flow

    Institute of Scientific and Technical Information of China (English)

    Sergey B.LEONOV; Dmitry A.YARANTSEV; Anatoly P.NAPARTOVICH; Igor V.KOCHETOV

    2007-01-01

    Fundamental problems related to the high-speed combustion are analyzed. The result of plasma-chemical modeling is presented as a motivation of experimental activity.Numerical simulations of the effect of uniform non-equilibrium discharge on the premixed hydrogen and ethylene-air mixture in supersonic flow demonstrate an advantage of such a technique over a heating.Experimental results on multi-electrode non-uniform discharge maintenance behind wallstep and in cavity of supersonic flow are presented.The model test on hydrogen and ethylene ignition is demonstrated at direct fuel injection to low-temperature high-speed airflow.

  19. High-speed wavefront modulation in complex media (Conference Presentation)

    Science.gov (United States)

    Turtaev, Sergey; Leite, Ivo T.; Cizmár, TomáÅ.¡

    2017-02-01

    Using spatial light modulators(SLM) to control light propagation through scattering media is a critical topic for various applications in biomedical imaging, optical micromanipulation, and fibre endoscopy. Having limited switching rate, typically 10-100Hz, current liquid-crystal SLM can no longer meet the growing demands of high-speed imaging. A new way based on binary-amplitude holography implemented on digital micromirror devices(DMD) has been introduced recently, allowing to reach refreshing rates of 30kHz. Here, we summarise the advantages and limitations in speed, efficiency, scattering noise, and pixel cross-talk for each device in ballistic and diffusive regimes, paving the way for high-speed imaging through multimode fibres.

  20. Ultra-high-speed optical and electronic distributed devices

    Energy Technology Data Exchange (ETDEWEB)

    Hietala, V.M.; Plut, T.A.; Kravitz, S.H.; Vawter, G.A.; Wendt, J.R.; Armendariz, M.G.

    1995-08-01

    This report summarizes work on the development of ultra-high-speed semiconductor optical and electronic devices. High-speed operation is achieved by velocity matching the input stimulus to the output signal along the device`s length. Electronic devices such as field-effect transistors (FET`s), should experience significant speed increases by velocity matching the electrical input and output signals along the device. Likewise, optical devices, which are typically large, can obtain significant bandwidths by velocity matching the light being generated, detected or modulated with the electrical signal on the device`s electrodes. The devices discussed in this report utilize truly distributed electrical design based on slow-wave propagation to achieve velocity matching.

  1. High-speed pulse-shape generator, pulse multiplexer

    Science.gov (United States)

    Burkhart, Scott C.

    2002-01-01

    The invention combines arbitrary amplitude high-speed pulses for precision pulse shaping for the National Ignition Facility (NIF). The circuitry combines arbitrary height pulses which are generated by replicating scaled versions of a trigger pulse and summing them delayed in time on a pulse line. The combined electrical pulses are connected to an electro-optic modulator which modulates a laser beam. The circuit can also be adapted to combine multiple channels of high speed data into a single train of electrical pulses which generates the optical pulses for very high speed optical communication. The invention has application in laser pulse shaping for inertial confinement fusion, in optical data links for computers, telecommunications, and in laser pulse shaping for atomic excitation studies. The invention can be used to effect at least a 10.times. increase in all fiber communication lines. It allows a greatly increased data transfer rate between high-performance computers. The invention is inexpensive enough to bring high-speed video and data services to homes through a super modem.

  2. TCP-Adaptive in High Speed Long Distance Networks

    Directory of Open Access Journals (Sweden)

    Quan Liu

    2014-02-01

    Full Text Available With the development of high performance computing and increasing of network bandwidth, more and more applications require fast data transfer over high-speed long-distance networks. Research shows that the standard TCP Reno cannot fulfill the requirement of fast transfer of massive data due to its conservative congestion control mechanism. Some works have been proposed to improve the TCP throughput performance using more aggressive window increasing tactics and obtain substantial achievements. However, they cannot be strictly proved to be comprehensively suitable for high-speed complex network environments. In this paper, we propose TCP-Adaptive, an adaptive congestion control algorithm adjusting the increasing congestion window dynamically. The algorithm improves logarithmic detection procedure for available bandwidth in the flow path by distinguishing the first detection in congestion avoidance and retransmission timeout. On the other hand, an adaptive control algorithm is proposed to achieve better performance in high-speed long-distance networks. The algorithm uses round trip time (RTT variations to predict the congestion trends to update the increments of congestion window. Simulations verify the property of TCP-Adaptive and show satisfying performance in throughput, RTT fairness aspects over high-speed long-distance networks. Especially in sporadic loss environment, TCP-Adaptive shows a significant adaptability with the variations of link quality

  3. High-speed traveling-wave electro-absorption modulators

    Science.gov (United States)

    Westergren, Urban; Yu, Yichuan; Thylén, Lars

    2006-07-01

    Electroabsorption modulators (EAM) based on quantum-confined Stark effect (QCSE) in multiplequantum wells (MQW) have been demonstrated to provide high-speed, low drive voltage, and high extinction ratio. They are compact in size and can be monolithically integrated with continuous-wave (CW) lasers. In order to achieve both high speed and low drive-voltage operation, travelling-wave (TW) electrode structures can be used for EAMs. The inherently low impedance of high-speed EAMs may be transformed to values close to the standard 50Ohm impedance using periodic microwave structures with a combination of passive transmission lines with high characteristic impedance and active modulator sections with low impedance. Modulation bandwidths of 100GHz (-3dBe) have been accomplished with electrical reflections lower than -10dB in a 50Ohm system. Transmission at 80Gbit/s with non-return-to-zero (NRZ) code has been demonstrated for InP-based TWEAMs using electronic time-domain multiplexing (ETDM), indicating the possibility of reaching speeds of 100Gbit/s and beyond.

  4. Improving Efficiency of a Counter-Current Flow Moving Bed Granular Filter

    Energy Technology Data Exchange (ETDEWEB)

    Colver, G.M.; Brown, R.C.; Shi, H.; Soo, D.S-C.

    2002-09-18

    The goal of this research is to improve the performance of moving bed granular filters for gas cleaning at high temperatures and pressures. A second goal of the research is to optimize the performances of both solids and gas filtering processes through appropriate use of granular bed materials, particle sizes, feed rates etc. in a factorial study. These goals are directed toward applications of advanced coal-fired power cycles under development by the U.S. Department of Energy including pressurized fluidized bed combustion and integrated gasification/combined cycles based on gas turbines and fuel cells. Only results for particulate gas cleaning are reported here.

  5. Design of a coil satellite centrifuge and its performance on counter-current chromatographic separation of 4-methylumbelliferyl sugar derivatives with polar organic-aqueous two-phase solvent systems.

    Science.gov (United States)

    Shinomiya, Kazufusa; Tokura, Koji; Kimura, Emiru; Takai, Midori; Harikai, Naoki; Yoshida, Kazunori; Yanagidaira, Kazuhiro; Ito, Yoichiro

    2015-05-01

    A new high-speed counter-current chromatograph, named coil satellite centrifuge (CSC), was designed and fabricated in our laboratory. The CSC apparatus produces the satellite motion such that the coiled column simultaneously rotates around the sun axis (the angular velocity, ω1), the planet axis (ω2) and the satellite axis (the central axis of the column) (ω3). In order to achieve this triplicate rotary motion without twisting of the flow tube, the rotation of each axis was determined by the following formula: ω1=ω2+ω3. This relation enabled to lay out the flow tube without twisting by the simultaneous rotation of three axes. The flow tube was introduced from the bottom side of the apparatus into the sun axis of the first rotary frame reaching the upper side of the planet axis and connected to the column in the satellite axis. The performance of the apparatus was examined on separation of 4-methylumbelliferyl (MU) sugar derivatives as test samples with organic-aqueous two-phase solvent systems composed of ethyl acetate/1-butanol/water (3:2:5, v/v) for lower phase mobile and (1:4:5, v/v) for upper phase mobile. With lower phase mobile, five 4-MU sugar derivatives including β-D-cellobioside (Cel), β-D-glucopyranoside, α-D-mannopyranoside, β-D-fucopyranoside and α-L-fucopyranoside (α-L-Fuc) were separated with the combined rotation around each axis at counterclockwise (CCW) (ω1) - CCW (ω2) - CCW (ω3) by the flow tube distribution. With upper phase mobile, three 4-MU sugar derivatives including α-L-Fuc, β-D-galactopyranoside and Cel were separated with the combined rotation around each axis at clockwise (CW) (ω1) - CW (ω2) - CW (ω3) by the flow tube distribution. A series of experiments on peak resolution and stationary phase retention revealed that better partition efficiencies were obtained at the flow rate of 0.5 mL/min (column 1) and 0.8 mL/min (column 2) for lower phase mobile and 0.2 mL/min (column 1) and 0.4 mL/min (column 2) for upper phase

  6. An APC:WNT counter-current-like mechanism regulates cell division along the colonic crypt axis: a mechanism that explains how APC mutations induce proliferative abnormalities that drive colon cancer development.

    Directory of Open Access Journals (Sweden)

    Bruce M Boman

    2013-11-01

    Full Text Available APC normally down-regulates WNT signaling in human colon, and APC mutations cause proliferative abnormalities in premalignant crypts leading to colon cancer, but the mechanisms are unclear at the level of spatial and functional organization of the crypt. Accordingly, we postulated a counter-current-like mechanism based on gradients of factors (APC;WNT that regulate colonocyte proliferation along the crypt axis. During crypt renewal, stem cells (SCs at the crypt bottom generate non-SC daughter cells that proliferate and differentiate while migrating upwards. The APC concentration is low at the crypt bottom and high at the top (where differentiated cells reside. WNT signaling, in contrast, is high at the bottom (where SCs reside and low at the top. Given that WNT and APC gradients are counter to one another, we hypothesized that a counter-current-like mechanism exists. Since both APC and WNT signaling components (e.g. survivin are required for mitosis, this mechanism establishes a zone in the lower crypt where conditions are optimal for maximal cell division and mitosis orientation (symmetric versus asymmetric. APC haploinsufficiency diminishes the APC gradient, shifts the proliferative zone upwards, and increases symmetric division, which causes SC overpopulation. In homozygote mutant crypts, these changes are exacerbated. Thus, APC-mutation-induced changes in the counter-current-like mechanism cause expansion of proliferative populations (SCs, rapidly-proliferating cells during tumorigenesis. We propose this mechanism also drives crypt fission, functions in the crypt cycle, and underlies adenoma development. Novel chemoprevention approaches designed to normalize the two gradients and readjust the proliferative zone downwards, might thwart progression of these premalignant changes.

  7. Strain rate effect in high-speed wire drawing process

    Science.gov (United States)

    He, S.; Van Houtte, P.; Van Bael, A.; Mei, F.; Sarban, A.; Boesman, P.; Galvez, F.; Atienza, J. M.

    2002-05-01

    This paper presents a study on the strain rate effect during high-speed wire drawing process by means of finite element simulation. Based on the quasistatic stresses obtained by normal tensile tests and dynamic stresses at high strain rates by split Hopkinson pressure bar tests, the wire drawing process was simulated for low carbon steel and high carbon steel. The results show that both the deformation process and the final properties of drawn wires are influenced by the strain rate.

  8. Toward high-speed access technologies: results from MUSE

    Science.gov (United States)

    Wellen, Jeroen; Smets, Rob; Hellenthal, Wim; Lepley, Jason; Tsalamanis, Ioannis; Walker, Stuart; Ng'oma, Anthony; Rijckenberg, Gert-Jan; Koonen, Ton; Habel, Kai; Langer, Klaus-Dieter

    2006-10-01

    The European MUSE project, which aims to enable "MUlti Service and access Everywhere", studies architectures, technologies and business scenarios facilitating the deployment of new Broadband Access Networks and Services. This paper gives an overview and particularly discusses results of some of the high-speed access technologies that are developed.

  9. Size Reduction of Tunable Micromachined Filters for High Speed Operations

    Institute of Scientific and Technical Information of China (English)

    Tomoyuki; Hino; Takeru; Amano; Wiganes; Janto; Fumio; Koyama

    2003-01-01

    The size reduction of tunable micromachined filters is carried out for high-speed wavelength tuning. We fabricated micromachined filters having a miniature structure with an air gap of 300 run and a short cantilever of 45 urn, exhibiting fast response of below 3 us.

  10. Size Reduction of Tunable Micromachined Filters for High Speed Operations

    Institute of Scientific and Technical Information of China (English)

    Tomoyuki Hino; Takeru Amano; Wiganes Janto; Fumio Koyama

    2003-01-01

    The size reduction of tunable micromachined filters is carried out for high-speed wavelength tuning. We fabricated micromachined filters having a miniature structure with an air gap of 300 nm and a short cantilever of 45 μm, exhibiting fast response of below 3 μs.

  11. APPLICATION OF POWDER HIGH-SPEED STEEL AS ANTIFRICTION MATERIAL

    Directory of Open Access Journals (Sweden)

    M. Beznak

    2011-01-01

    Full Text Available The influence of disulphide molybdenum additives on antifriction characteristics of powder high-speed steel produced by means of hot hydrostatic pressing is investigated. It is shown that disulphide molybdenum additives promote the decrease of coefficient of friction and temperature in hearth of friction as a result the increase of wear resistance of steel.

  12. Modelling Of Residual Stresses Induced By High Speed Milling Process

    Science.gov (United States)

    Desmaison, Olivier; Mocellin, Katia; Jardin, Nicolas

    2011-05-01

    Maintenance processes used in heavy industries often include high speed milling operations. The reliability of the post-process material state has to be studied. Numerical simulation appears to be a very interesting way to supply an efficient residual stresses (RS) distribution prediction. Because the adiabatic shear band and the serrated chip shaping are features of the austenitic stainless steel high speed machining, a 2D high speed orthogonal cutting model is briefly presented. This finite element model, developed on Forge® software, is based on data taken from Outeiro & al.'s paper [1]. A new behaviour law fully coupling Johnson-Cook's constitutive law and Latham and Cockcroft's damage model is detailed in this paper. It ensures results that fit those found in literature. Then, the numerical tools used on the 2D model are integrated to a 3D high speed milling model. Residual stresses distribution is analysed, on the surface and into the depth of the material. Various revolutions and passes of the two teeth hemispheric mill on the workpiece are simulated. Thus the sensitivity of the residual stresses generation to the cutting conditions can be discussed. In order to validate the 3D model, a comparison of the cutting forces measured by EDF R&D to those given by numerical simulations is achieved.

  13. Minimum Plate Thickness in High-Speed Craft

    DEFF Research Database (Denmark)

    Pedersen, Preben Terndrup; Zhang, Shengming

    1998-01-01

    The minimum plate thickness requirements specified by the classification societies for high-speed craft are supposed to ensure adequate resistance to impact loads such as collision with floating objects and objects falling on the deck. The paper presents analytical methods of describing such impact...

  14. Exploring THz band for high speed wireless communications

    DEFF Research Database (Denmark)

    Yu, Xianbin; Zhang, Hangkai; Jia, Shi;

    2016-01-01

    We overview recent trend in developing high speed wireless communication systems by exploring large bandwidth available in the THz band, and we also present our recent experimental achievements on 400 GHz wireless transmission with a data rate of up to 60 Gbit/s by using a uni-travelling carrier...

  15. High Speed Lunar Navigation for Crewed and Remotely Piloted Vehicles

    Science.gov (United States)

    Pedersen, L.; Allan, M.; To, V.; Utz, H.; Wojcikiewicz, W.; Chautems, C.

    2010-01-01

    Increased navigation speed is desirable for lunar rovers, whether autonomous, crewed or remotely operated, but is hampered by the low gravity, high contrast lighting and rough terrain. We describe lidar based navigation system deployed on NASA's K10 autonomous rover and to increase the terrain hazard situational awareness of the Lunar Electric Rover crew.

  16. High-Speed Computer-Controlled Switch-Matrix System

    Science.gov (United States)

    Spisz, E.; Cory, B.; Ho, P.; Hoffman, M.

    1985-01-01

    High-speed computer-controlled switch-matrix system developed for communication satellites. Satellite system controlled by onboard computer and all message-routing functions between uplink and downlink beams handled by newly developed switch-matrix system. Message requires only 2-microsecond interconnect period, repeated every millisecond.

  17. High-Frequency Technical Trading: The Importance of Speed

    NARCIS (Netherlands)

    M.L. Scholtus (Martin); D.J.C. van Dijk (Dick)

    2012-01-01

    textabstractThis paper investigates the importance of speed for technical trading rule performance for three highly liquid ETFs listed on NASDAQ over the period January 6, 2009 up to September 30, 2009. In addition we examine the characteristics of market activity over the day and within subperiods

  18. Intel Legend and CERN would build up high speed Internet

    CERN Multimedia

    2002-01-01

    Intel, Legend and China Education and Research Network jointly announced on the 25th of April that they will be cooperating with each other to build up the new generation high speed internet, over the next three years (1/2 page).

  19. High Speed Rail (HSR) in the United States

    Science.gov (United States)

    2009-12-08

    passenger rail service, while trying to help rail 25 Available at http://www.fomento.es/MFOMWeb/ paginas ...Offers Guideposts for U.S.,” The New York Times On the Web , May 30, 2009. High Speed Rail (HSR) in the United States Congressional Research

  20. Recent Advances in Ultra-High-Speed Optical Signal Processing

    DEFF Research Database (Denmark)

    Mulvad, Hans Christian Hansen; Palushani, Evarist; Hu, Hao;

    2012-01-01

    We review recent advances in the optical signal processing of ultra-high-speed serial data signals up to 1.28 Tbit/s, with focus on applications of time-domain optical Fourier transformation. Experimental methods for the generation of symbol rates up to 1.28 Tbaud are also described....

  1. Corrosion Inhibition of High Speed Steel by Biopolymer HPMC Derivatives

    OpenAIRE

    Shih-Chen Shi; Chieh-Chang Su

    2016-01-01

    The corrosion inhibition characteristics of the derivatives of biopolymer hydroxypropyl methylcellulose (HPMC), hydroxypropyl methylcellulose phthalate (HPMCP), and hydroxypropyl methylcellulose acetate succinate (HPMCAS) film are investigated. Based on electrochemical impedance spectroscopic measurements and potentiodynamic polarization, the corrosion inhibition performance of high speed steel coated with HPMC derivatives is evaluated. The Nyquist plot and Tafel polarization demonstrate prom...

  2. Characterising argon-bomb balloons for high-speed photography

    CSIR Research Space (South Africa)

    Olivier, M

    2013-08-01

    Full Text Available A method to optimise the geometry, explosive charge mass and volume of an argon bomb for specific lighting requirements has been proposed. The method is specifically aimed at applications that require photographic diagnostics with ultra-high speed...

  3. Faster than "g", Revisited with High-Speed Imaging

    Science.gov (United States)

    Vollmer, Michael; Mollmann, Klaus-Peter

    2012-01-01

    The introduction of modern high-speed cameras in physics teaching provides a tool not only for easy visualization, but also for quantitative analysis of many simple though fast occurring phenomena. As an example, we present a very well-known demonstration experiment--sometimes also discussed in the context of falling chimneys--which is commonly…

  4. Research and practice: The European High Speed Station

    NARCIS (Netherlands)

    Triggianese, M.

    2014-01-01

    The practices of planning and architecture are undergoing considerable transformation especially for urban developments asso-ciated to infrastructural changes. This paper considers the proliferation of high-speed railways in Europe as a research opportunity to better understand the practice of compl

  5. Towards a high-speed quantum random number generator

    Science.gov (United States)

    Stucki, Damien; Burri, Samuel; Charbon, Edoardo; Chunnilall, Christopher; Meneghetti, Alessio; Regazzoni, Francesco

    2013-10-01

    Randomness is of fundamental importance in various fields, such as cryptography, numerical simulations, or the gaming industry. Quantum physics, which is fundamentally probabilistic, is the best option for a physical random number generator. In this article, we will present the work carried out in various projects in the context of the development of a commercial and certified high speed random number generator.

  6. Modeling of high speed micro rotors in moderate flow confinement

    NARCIS (Netherlands)

    Dikmen, E.; Hoogt, van der P.J.M.; Aarts, R.G.K.M.

    2008-01-01

    The recent developments in high speed micro rotating machinery lead to the need for multiphysical modeling of the rotor and the surrounding medium. In this study, thermal and flow induced effects on rotor dynamics of geometries with moderate flow confinement are studied. The structure is modeled via

  7. Design criteria for light high speed desert air cushion vehicles

    Science.gov (United States)

    Abulnaga, B. E.

    An evaluation is made of the applicability and prospective performance of ACVs in trans-Saharan cargo transport, in view of the unique characteristics of the dry sand environment. The lightweight/high-speed ACV concept envisioned is essentially ground effect aircraftlike, with conventional wheels as a low-speed backup suspension system. A propeller is used in ground effect cruise. Attention is given to the effects on vehicle stability and performance of sandy surface irregularities of the desert topography and of cross-winds from various directions relative to vehicle movement.

  8. Study on High-Speed Magnitude Approximation for Complex Vectors

    Institute of Scientific and Technical Information of China (English)

    陈建春; 杨万海; 许少英

    2003-01-01

    High-speed magnitude approximation algorithms for complex vectors are discussed intensively. The performance and the convergence speed of these approximation algorithms are analyzed. For the polygon fitting algorithms, the approximation formula under the least mean square error criterion is derived. For the iterative algorithms, a modified CORDIC (coordinate rotation digital computer) algorithm is developed. This modified CORDIC algorithm is proved to be with a maximum relative error about one half that of the original CORDIC algorithm. Finally, the effects of the finite register length on these algorithms are also concerned, which shows that 9 to 12-bit coefficients are sufficient for practical applications.

  9. Switching speed limitations of high power IGBT modules

    DEFF Research Database (Denmark)

    Incau, Bogdan Ioan; Trintis, Ionut; Munk-Nielsen, Stig

    2015-01-01

    In this paper the switching speed limits of high power IGBT modules are investigated. The limitation of turn-on and turn-off switching speeds of the IGBTs are experimentally detected in a pulse tester. Different dc-bus stray inductances are considered, as well as the worst case scenario...... for the blocking dc-link voltage. Switching losses are analyzed upon a considerable variation of resistor value from turn-on gate driver side. Short circuit operations are investigated along with safe operating area for entire module to validate electrical capabilities under extreme conditions....

  10. Development of small bore, high speed tapered roller bearing

    Science.gov (United States)

    Morrison, F. R.; Gassel, S. S.; Bovenkerk, R. L.

    1981-01-01

    The performance of four rolling bearing configurations for use on the input pinion shaft of a proposed commercial helicopter transmission was evaluated. The performance characteristics of a high speed tapered roller bearing operating under conditions comparable to those existing at this input pinion shaft were defined. The tapered roller bearing shaft support configuration was developed for the gearbox using commercially available bearing designings. The configuration was optimized and interactive thermomechanically system analyzed. Automotive pinion quality tapered roller bearings were found to be reliable under load and speed conditions in excess of those anticipated in the helicopter transmission. However, it is indicated that the elastohydrodynamic lubricant films are inadequate.

  11. Research of high speed optical switch based on compound semiconductor

    Institute of Scientific and Technical Information of China (English)

    WANG MingHua; QI Wei; YU Hui; JIANG XiaoQing; YANG JianYi

    2009-01-01

    High-speed optical switch and its array are the crucial components of all-optical switching system. This paper presents the analytical model of a total-internal-reflection (TIR) optical switch. By employing the carrier injection effect in GaAs and the GaAs/AlGaAs double heterojunction structure, the X-junction TIR switch and the Mach-Zehnder interference (MZI) switch are demonstrated at 1.55 IJm. The measured results show that the extinction ratio of both switches exceeds 20 dB. The switching speed reaches the scale of 10 ns.

  12. Design of a high speed rotating mechanical shutter

    Energy Technology Data Exchange (ETDEWEB)

    Stowers, I.F.; Merritt, B.T.; McFann, C.B.

    1979-11-06

    A high-speed rotating shutter was designed to operate in a 10/sup -6/ Torr vacuum at the optical focus of a laser spatial filter. The shutter is basically a wheel, with a single 3 x 10-mm slot at the perimeter, which rotates with a peripheral speed of 1 km/s. The motor to drive the rotating wheel is magnetically suspended and synchronously wound. The wheel achieves a 4 ..mu..s opening time and a timing accuracy of better than 0.2 ..mu..s. (MOW)

  13. High-Speed Low Power Design in CMOS

    DEFF Research Database (Denmark)

    Ghani, Arfan; Usmani, S. H.; Stassen, Flemming

    2004-01-01

    Static CMOS design displays benefits such as low power consumption, dominated by dynamic power consumption. In contrast, MOS Current Mode Logic (MCML) displays static rather than dynamic power consumption. High-speed low-power design is one of the many application areas in VLSI that require...... the appropriate domains of performance and power requirements in which MCML presents benefits over standard CMOS. An optimized cell library is designed and implemented in both CMOS and MCML in order to make a comparison with reference to speed and power. Much more time is spent in order to nderstand...

  14. Preparative isolation and purification of senkyunolide-I, senkyunolide-H and ferulic acid from Rhizoma Chuanxiong using counter-current chromatography.

    Science.gov (United States)

    Wei, Yun; Hu, Jia; Li, Hao; Liu, Jiangang

    2011-12-01

    Three active compounds, senkyunolide-I, senkyunolide-H and ferulic acid (FA), were successfully isolated and purified from the extracts of Rhizoma Chuanxiong by counter-current chromatography (CCC). Based on the principle of the partition coefficient values (k) for target compounds and the separation factor (α) between target compounds, the two-phase solvent system that contains n-hexane-ethyl acetate-methanol-water at an optimized volume ratio of 3:7:4:6 v/v was selected for the CCC separation, and the lower phase was employed as the mobile phase in the head-to-tail elution mode. In a single run, 400 mg of the crude extract yielded pure senkyunolide-I (6.4 mg), senkyunolide-H (1.7 mg) and FA (4.4 mg) with the purities of 98, 93 and 99%, respectively. The CCC fractions were analyzed by high-performance liquid chromatography, and the structures of the three active compounds were identified by MS and (1)H NMR.

  15. Scale-up protein separation on stainless steel wide bore toroidal columns in the type-J counter-current chromatography.

    Science.gov (United States)

    Guan, Yue Hugh; Hewitson, Peter; van den Heuvel, Remco N A M; Zhao, Yan; Siebers, Rick P G; Zhuang, Ying-Ping; Sutherland, Ian

    2015-12-11

    Manufacturing high-value added biotech biopharmaceutical products (e.g. therapeutic proteins) requires quick-to-develop, GMP-compliant, easy-to-scale and cost effective preparatory chromatography technologies. In this work, we describe the construction and testing of a set of 5-mm inner diameter stainless steel toroidal columns for use on commercially available preparatory scale synchronous J-type counter-current chromatography (CCC) machinery. We used a 20.2m long column with an aqueous two-phase system containing 14% (w/w) PEG1000 and 14% (w/w) potassium phosphate at pH 7, and tested a sample loading of 5% column volume and a mobile phase flow rate of 20ml/min. We then satisfactorily demonstrated the potential for a weekly protein separation and preparation throughput of ca. 11g based on a normal weekly routine for separating a pair of model proteins by making five stacked injections on a single portion of stationary phase with no stripping. Compared to our previous 1.6mm bore PTFE toroidal column, the present columns enlarged the nominal column processing throughput by nearly 10. For an ideal model protein injection modality, we observed a scaling up factor of at least 21. The 2 scales of protein separation and purification steps were realized on the same commercial CCC device.

  16. Ultra High-Speed Radio Frequency Switch Based on Photonics.

    Science.gov (United States)

    Ge, Jia; Fok, Mable P

    2015-11-26

    Microwave switches, or Radio Frequency (RF) switches have been intensively used in microwave systems for signal routing. Compared with the fast development of microwave and wireless systems, RF switches have been underdeveloped particularly in terms of switching speed and operating bandwidth. In this paper, we propose a photonics based RF switch that is capable of switching at tens of picoseconds speed, which is hundreds of times faster than any existing RF switch technologies. The high-speed switching property is achieved with the use of a rapidly tunable microwave photonic filter with tens of gigahertz frequency tuning speed, where the tuning mechanism is based on the ultra-fast electro-optics Pockels effect. The RF switch has a wide operation bandwidth of 12 GHz and can go up to 40 GHz, depending on the bandwidth of the modulator used in the scheme. The proposed RF switch can either work as an ON/OFF switch or a two-channel switch, tens of picoseconds switching speed is experimentally observed for both type of switches.

  17. Design the High Speed Kogge-Stone Adder by Using

    Directory of Open Access Journals (Sweden)

    MUX

    2015-08-01

    Full Text Available In this Technical era the high speed and low area of VLSI chip are very- very essential factors. Day by day number of transistors and other active and passive elements are growing on VLSI chip. In Integral part of the processor adders play an important role. In this paper we are using proposed kogge-stone adders for binary addition to reduce the size and increase the efficiency or processors speed. Proposing kogge stone adder provides less components, less path delay and better speed compare to other existing kogge stone adder and other adders. Here we are comparing the kogge stone adders of different-different word size from other adders. The design and experiment can be done by the aid of Xilinx 14.1i Spartan 3 device family.

  18. Isolation and Purification of Alkaloid Compounds from the Roots of Menispermum Dauricum Using Preparative High-speed Counter-current Chromatography%制备型高速逆流色谱分离纯化北豆根中的生物碱类化合物

    Institute of Scientific and Technical Information of China (English)

    骆厚鼎; 彭爱华; 叶昊宇; 陈俐娟

    2009-01-01

    采用制备型高速逆流色谱仪TBE-300A分离纯化北豆根药材中的活性生物碱类化合物.在实验过程中对溶剂系统和参数条件进行了系统的优化,获得较好的分离条件:溶剂系统为石油醚-乙酸乙酯-乙醇-水(1:2:1:2,V/V/V/V),上相(有机相)为固定相,下相(水相)为流动相,反相模式洗脱;进样浓度20mg/ml;进样体积20ml;流速2.0 ml/min;转速850 r/min.通过一步分离,获得了四种高纯度的生物碱类化合物,经HPLC、MS和NMR鉴定,分别为蝙蝠葛苏林碱(101.47mg,96.7%),蝙蝠葛碱(155.68mg,95.6%),蝙蝠葛诺林碱((25.4mg,96.2%),蝙蝠葛新苛林碱(10.2mg,97.8%).

  19. Separation and Purification of Harpagoside and Sibirioside A from Extract of Scrophulariae Radix by Macroporous Resin and High-speed Counter-current Chromatography%大孔吸附树脂-高速逆流色谱法分离纯化玄参中哈巴俄苷和斩龙剑苷A

    Institute of Scientific and Technical Information of China (English)

    李行诺; 张文强; 钱夏娜; 童胜强; 颜继忠

    2014-01-01

    目的 以玄参的干燥根为原料,建立大孔吸附树脂-高速逆流色谱法(HSCCC)分离纯化玄参中哈巴俄苷与斩龙剑苷A的方法.方法 玄参粗提物先经过大孔吸附树脂初步分离,富集目标化合物.然后以正丁醇-乙酸乙酯-水(1∶9∶10)为溶剂体系,上相为固定相,下相为流动相,流速1.5 mL·min-1,检测波长210 nm,利用制备型HSCCC分离纯化哈巴俄苷和斩龙剑苷A.结果 经过大孔吸附树脂-高速逆流色谱法分离后,一次性得到哈巴俄苷和斩龙剑苷A,经HPLC检测其纯度分别为98.1%和97.2%.经1H-NMR和13C-NMR鉴定结构为哈巴俄苷和斩龙剑苷A.结论 该方法能够简便、高效地制备玄参中的哈巴俄苷和斩龙剑苷A.

  20. Isalation and Separation Isoorientin and Isovitexin from Patrinia Villosa Juss by High Speed Counter-current Chromatography%白花败酱草中异牡荆苷和异荭草苷的高速逆流色谱分离和制备

    Institute of Scientific and Technical Information of China (English)

    彭金咏; 范国荣; 吴玉田; 陈洪渊

    2005-01-01

    应用高速逆流色谱分离制备白花败酱草中的异荭草苷和异牡荆苷,以乙酸乙酯:乙醇:水(4:1:5)为两相溶剂系统,上相为固定相,下相为流动相,流速2.0 mL/min,主机800 r/min,检测波长254 nm.以此分离条件经一步洗脱,从300mg白花败酱草粗提物中制备得到异荭草苷24.1 mg和异牡荆苷49.8 mg,产物纯度经HPLC检测高达98.0%,结构经UV、IR、MS、1 H NMR和13C NMR鉴定,二者均为首次从败酱属植物中分离得到.

  1. Numerical simulation of high speed incremental forming of aluminum alloy

    Science.gov (United States)

    Giuseppina, Ambrogio; Teresa, Citrea; Luigino, Filice; Francesco, Gagliardi

    2013-12-01

    In this study, an innovative process is analyzed with the aim to satisfy the industrial requirements, such as process flexibility, differentiation and customizing of products, cost reduction, minimization of execution time, sustainable production, etc. The attention is focused on incremental forming process, nowadays used in different fields such as: rapid prototyping, medical sector, architectural industry, aerospace and marine, in the production of molds and dies. Incremental forming consists in deforming only a small region of the workspace through a punch driven by a NC machine. SPIF is the considered variant of the process, in which the punch gives local deformation without dies and molds; consequently, the final product geometry can be changed by the control of an actuator without requiring a set of different tools. The drawback of this process is its slowness. The aim of this study is to assess the IF feasibility at high speeds. An experimental campaign will be performed by a CNC lathe with high speed to test process feasibility and the influence on materials formability mainly on aluminum alloys. The first results show how the material presents the same performance than in conventional speed IF and, in some cases, better material behavior due to the temperature field. An accurate numerical simulation has been performed to investigate the material behavior during the high speed process substantially confirming experimental evidence.

  2. Sound transmission loss of windows on high speed trains

    Science.gov (United States)

    Zhang, Yumei; Xiao, Xinbiao; Thompson, David; Squicciarini, Giacomo; Wen, Zefeng; Li, Zhihui; Wu, Yue

    2016-09-01

    The window is one of the main components of the high speed train car body structure through which noise can be transmitted. To study the windows’ acoustic properties, the vibration of one window of a high speed train has been measured for a running speed of 250 km/h. The corresponding interior noise and the noise in the wheel-rail area have been measured simultaneously. The experimental results show that the window vibration velocity has a similar spectral shape to the interior noise. Interior noise source identification further indicates that the window makes a contribution to the interior noise. Improvement of the window's Sound Transmission Loss (STL) can reduce the interior noise from this transmission path. An STL model of the window is built based on wave propagation and modal superposition methods. From the theoretical results, the window's STL property is studied and several factors affecting it are investigated, which provide indications for future low noise design of high speed train windows.

  3. High speed intravascular photoacoustic imaging of atherosclerotic arteries (Conference Presentation)

    Science.gov (United States)

    Piao, Zhonglie; Ma, Teng; Qu, Yueqiao; Li, Jiawen; Yu, Mingyue; He, Youmin; Shung, K. Kirk; Zhou, Qifa; Kim, Chang-Seok; Chen, Zhongping

    2016-02-01

    Cardiovascular disease is the leading cause of death in the industrialized nations. Accurate quantification of both the morphology and composition of lipid-rich vulnerable atherosclerotic plaque are essential for early detection and optimal treatment in clinics. In previous works, intravascular photoacoustic (IVPA) imaging for detection of lipid-rich plaque within coronary artery walls has been demonstrated in ex vivo, but the imaging speed is still limited. In order to increase the imaging speed, a high repetition rate laser is needed. In this work, we present a high speed integrated IVPA/US imaging system with a 500 Hz optical parametric oscillator laser at 1725 nm. A miniature catheter with 1.0 mm outer diameter was designed with a 200 μm multimode fiber and an ultrasound transducer with 45 MHz center frequency. The fiber was polished at 38 degree and enclosed in a glass capillary for total internal reflection. An optical/electrical rotary junction and pull-back mechanism was applied for rotating and linearly scanning the catheter to obtain three-dimensional imaging. Atherosclerotic rabbit abdominal aorta was imaged as two frame/second at 1725 nm. Furthermore, by wide tuning range of the laser wavelength from 1680 nm to 1770 nm, spectroscopic photoacoustic analysis of lipid-mimicking phantom and an human atherosclerotic artery was performed ex vivo. The results demonstrated that the developed IVPA/US imaging system is capable for high speed intravascular imaging for plaque detection.

  4. Differences in energy expenditure during high-speed versus standard-speed yoga: A randomized sequence crossover trial.

    Science.gov (United States)

    Potiaumpai, Melanie; Martins, Maria Carolina Massoni; Rodriguez, Roberto; Mooney, Kiersten; Signorile, Joseph F

    2016-12-01

    To compare energy expenditure and volume of oxygen consumption and carbon dioxide production during a high-speed yoga and a standard-speed yoga program. Randomized repeated measures controlled trial. A laboratory of neuromuscular research and active aging. Sun-Salutation B was performed, for eight minutes, at a high speed versus and a standard-speed separately while oxygen consumption was recorded. Caloric expenditure was calculated using volume of oxygen consumption and carbon dioxide production. Difference in energy expenditure (kcal) of HSY and SSY. Significant differences were observed in energy expenditure between yoga speeds with high-speed yoga producing significantly higher energy expenditure than standard-speed yoga (MD=18.55, SE=1.86, pyoga for volume of oxygen consumed and carbon dioxide produced. High-speed yoga results in a significantly greater caloric expenditure than standard-speed yoga. High-speed yoga may be an effective alternative program for those targeting cardiometabolic markers. Copyright © 2016 Elsevier Ltd. All rights reserved.

  5. High Speed Oblivious Random Access Memory (HS-ORAM)

    Science.gov (United States)

    2015-09-01

    and Automated Teller Machines ( ATM ) security while generally impractical due to performance limitations and high acquisition costs. This idea has...HIGH SPEED OBLIVIOUS RANDOM ACCESS MEMORY (HS-ORAM) PRIVATE MACHINES , INC. SEPTEMBER 2015 FINAL TECHNICAL REPORT...UNIT NUMBER I1 7. PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES) Private Machines Inc. 164 20th Street #3D Brooklyn, NY 11232 8. PERFORMING

  6. Overall optimization of high-speed semiconductor laser modules

    Institute of Scientific and Technical Information of China (English)

    LIU Yu; CHEN ShuoFu; WANG Xin; YUAN HaiQing; XIE Liang; ZHU NingHua

    2009-01-01

    Based on the high frequency techniques such as frequency response measurement, equivalent circuit modeling and packaging parasitics compensation, a comprehensive optimization method for packag-ing high-speed semiconductor laser module is presented in this paper. The experiments show that the small-signal magnitude frequency response of the TO packaged laser module is superior to that of laser diode in frequencies, and the in-band flatness and the phase-frequency linearity are also im-proved significantly.

  7. Ultra-high-speed serial optical communications: Enabling technologies

    DEFF Research Database (Denmark)

    Oxenløwe, Leif Katsuo; Galili, Michael; Mulvad, Hans Christian Hansen

    2008-01-01

    This paper will present recently identified and demonstrated key technologies for ultra-high-speed serial communications. Certain key components such as stabilised highly non-linear fibre switches, periodically poled Lithium Niobate devices and semiconductor optical amplifiers will be described...... with demonstrations of 640 Gb/s transmission, clock recovery, demultiplexing, add/drop, wavelength conversion and channel identification. Timing jitter tolerance is addressed through techniques to create flat-top pulses....

  8. Galvanometer deflection: a precision high-speed system.

    Science.gov (United States)

    Jablonowski, D P; Raamot, J

    1976-06-01

    An X-Y galvanometer deflection system capable of high precision in a random access mode of operation is described. Beam positional information in digitized form is obtained by employing a Ronchi grating with a sophisticated optical detection scheme. This information is used in a control interface to locate the beam to the required precision. The system is characterized by high accuracy at maximum speed and is designed for operation in a variable environment, with particular attention placed on thermal insensitivity.

  9. VERY HIGH-SPEED DRILL STRING COMMUNICATIONS NETWORK

    Energy Technology Data Exchange (ETDEWEB)

    David S. Pixton

    2002-11-01

    Testing of a high-speed digital data transmission system for drill pipe is described. Passive transmission of digital data through 1000 ft of telemetry drill pipe has been successfully achieved. Data rates of up to 2 Mbit/sec have been tested through the 1000 ft system with very low occurrence of data errors: required error correction effort is very low or nonexistent. Further design modifications have been made to improve manufacturability and high pressure robustness of the transmission line components. Failure mechanisms of previous designs at high pressure and high temperature are described. Present design limitations include high temperature application.

  10. Convective high-speed flow and field-aligned high-speed flows explored by TC-1

    Institute of Scientific and Technical Information of China (English)

    ZHANG LingQian; LIU ZhenXing; MA ZhiWei; W.BAUMJOHANN; M.W.DUNLOP4; WANG GuangJun; WANG Xiao; H.REME; C.CARR

    2008-01-01

    From June 1, 2004 to October 31, 2006, a total 465 high-speed flow events are observed by the TC-1 satellite in the near-Earth region (-13 RE < X < -9 RE, |Y|<10 RE, |2|<5 RE). Based on the angle between the flow and the magnetic field, the high-speed flow events are further divided into two types, that is,field-aligned high-speed flow (FAHF) in the plasma sheet boundary and convective bursty bulk flow (BBF) in the center plasma sheet. Among the total 465 high-speed flow events, there are 371 FAHFs,and 94 BBFs. The CHF are mainly concentrated in the plasma sheet, the intersection angle between the flow and the magnetic field is larger, the magnetic field intensity is relatively weak. The FHF are mainly distributed near the boundary layer of the plasma sheet, the intersection angle between the flow and magnetic field is smaller, and the magnetic field intensity is relatively strong. The convective BBFs have an important effect on the substorm.

  11. Difference in muscle activation patterns during high-speed versus standard-speed yoga: A randomized sequence crossover study.

    Science.gov (United States)

    Potiaumpai, Melanie; Martins, Maria Carolina Massoni; Wong, Claudia; Desai, Trusha; Rodriguez, Roberto; Mooney, Kiersten; Signorile, Joseph F

    2017-02-01

    To compare the difference in muscle activation between high-speed yoga and standard-speed yoga and to compare muscle activation of the transitions between poses and the held phases of a yoga pose. Randomized sequence crossover trial SETTING: A laboratory of neuromuscular research and active aging Interventions: Eight minutes of continuous Sun Salutation B was performed, at a high speed versus a standard-speed, separately. Electromyography was used to quantify normalized muscle activation patterns of eight upper and lower body muscles (pectoralis major, medial deltoids, lateral head of the triceps, middle fibers of the trapezius, vastus medialis, medial gastrocnemius, thoracic extensor spinae, and external obliques) during the high-speed and standard-speed yoga protocols. Difference in normalized muscle activation between high-speed yoga and standard-speed yoga. Normalized muscle activity signals were significantly higher in all eight muscles during the transition phases of poses compared to the held phases (pyoga across the entire session. Our results show that transitions from one held phase of a pose to another produces higher normalized muscle activity than the held phases of the poses and that overall activity is greater during highspeed yoga than standard-speed yoga. Therefore, the transition speed and associated number of poses should be considered when targeting specific improvements in performance. Copyright © 2016 Elsevier Ltd. All rights reserved.

  12. Development of a high speed crowbar for LANSCE

    Energy Technology Data Exchange (ETDEWEB)

    Friedrichs, C. Jr.; Lyles, J.T.M.; Doub, J.M.

    1997-08-01

    Each of the four 200 MHz Final Power Amplifiers (FPAs) in the LANSCE proton linac has its own capacitor bank and crowbar. The dissipation in the 10{Omega} crowbar limiting resistor is as high as 67 kW, and oil cooling is used. The authors stated upgrade goal was to substantially reduce the limiting resistor dissipation and eliminate the oil cooling. Early tests showed that the fault energy quickly rose to unacceptable levels as the current limiting resistance was reduced. FPA arcs are normally quenched by interrupting the FPA modulator current, and the crowbar waits 10 {mu}s for this to occur. The successful upgrade strategy was to replace the 10{Omega} resistor with a 3{Omega} air cooled resistor and to add a high speed crowbar circuit which operates only if there are simultaneous arcs in the FPA and its modulator. This paper describes the high speed circuit and its interface with the existing crowbar. Test results are also given.

  13. REDUCTION OF EMISSIONS FROM A HIGH SPEED FERRY

    Energy Technology Data Exchange (ETDEWEB)

    Thompson,G.; Gautam, M; Clark, N; Lyons, D; Carder, D; Riddle, W; Barnett, R; Rapp, B; George, S

    2003-08-24

    Emissions from marine vessels are being scrutinized as a major contributor to the total particulate matter (TPM), oxides of sulfur (SOx) and oxides of nitrogen (NOx) environmental loading. Fuel sulfur control is the key to SOx reduction. Significant reductions in the emissions from on-road vehicles have been achieved in the last decade and the emissions from these vehicles will be reduced by another order of magnitude in the next five years: these improvements have served to emphasize the need to reduce emissions from other mobile sources, including off road equipment, locomotives, and marine vessels. Diesel-powered vessels of interest include ocean going vessels with low- and medium-speed engines, as well as ferries with high speed engines, as discussed below. A recent study examined the use of intake water injection (WIS) and ultra low sulfur diesel (ULSD) to reduce the emissions from a high-speed passenger ferry in southern California. One of the four Detroit Diesel 12V92 two-stroke high speed engines that power the Waverider (operated by SCX, inc.) was instrumented to collect intake airflow, fuel flow, shaft torque, and shaft speed. Engine speed and shaft torque were uniquely linked for given vessel draft and prevailing wind and sea conditions. A raw exhaust gas sampling system was utilized to measure the concentration of NOx, carbon dioxide (CO2), and oxygen (O2) and a mini dilution tunnel sampling a slipstream from the raw exhaust was used to collect TPM on 70 mm filters. The emissions data were processed to yield brake-specific mass results. The system that was employed allowed for redundant data to be collected for quality assurance and quality control. To acquire the data, the Waverider was operated at five different steady state speeds. Three modes were in the open sea off Oceanside, CA, and idle and harbor modes were also used. Data have showed that the use of ULSD along with water injection (WIS) could significantly reduce the emissions of NOx and PM

  14. Comprehensive multi-channel multi-dimensional counter-current chromatography for separation of tanshinones from Salvia miltiorrhiza Bunge.

    Science.gov (United States)

    Meng, Jie; Yang, Zhi; Liang, Junling; Zhou, Hui; Wu, Shihua

    2014-01-03

    Multi-dimensional chromatography offers the increased resolution and peak capacity by coupling of multiple columns with the same or different separation mechanisms. In this work, a novel multi-channel multi-dimensional counter-current chromatography (CCC) has been successfully constructed and used for several two-dimensional (2D) and three-dimensional (3D) CCC separations including 2D A×B/A×C, A×B-C and A-B×C, and 3D A×B×C systems. These 2D and 3D CCC systems were further applied to separate the bioactive tanshinones from the extract of Tanshen (or Danshen, Salvia miltiorrhiza Bunge), a famous Traditional Chinese Medicine (TCM). As a result, the developed 2D and 3D CCC methods were successful and efficient for resolving the tanshinones from complex extracts. Compared to the 1D multiple columns CCC separation, the 2D and 3D CCC decrease analysis time, reduce solvent consumption and increase sample throughput significantly. It may be widely used for current drug development, metabolomic analysis and natural product isolation.

  15. Studies on the Performance of Different Coiled Column Configurations for Compact Type-I Counter-current Chromatography

    Science.gov (United States)

    Yang, Yi; Gu, Dongyu; Aisa, Haji Akber; Ito, Yoichiro

    2011-01-01

    Three types of novel coiled column configurations, i.e., a triangular coiled column and elliptical coiled columns I and II, were designed for type-I countercurrent chromatography and their performances were evaluated with two solvent systems each with suitable test samples. Three DNP-amino acids (DNP-DL-glu, DNP-β-ala and DNP-L-ala) were separated with a moderately hydrophobic two-phase solvent system composed of hexane-ethyl acetate-metanol-0.1M hydrochloric acid (1:1:1:1, v/v), while two dipeptides (tryptophyl tyrosine and valyl-tyrosine) were separated with a polar solvent system composed of 1-butanol-acetic acid-water (4.75:0.25:5, v/v). The overall results indicated that the performance of compact type-I counter-current chromatography was improved by elliptical coiled column II which was mounted with its maximum coil diameter perpendicular to the surface of the column holder. Hydrodynamic effects involved in these separations were discussed. PMID:21491597

  16. Recovery of Butanol by Counter-Current Carbon Dioxide Fractionation with its Potential Application to Butanol Fermentation.

    Science.gov (United States)

    Solana, Miriam; Qureshi, Nasib; Bertucco, Alberto; Eller, Fred

    2016-06-30

    A counter-current CO₂ fractionation method was applied as a mean to recover n-butanol and other compounds that are typically obtained from biobutanol fermentation broth from aqueous solutions. The influence of operating variables, such as solvent-to-feed ratio, temperature, pressure and feed solution composition was experimentally studied in terms of separation efficiency, butanol removal rate, total removal and butanol concentration in the extract at the end of the continuous cycle. With respect to the temperature and pressure conditions investigated, results show that the highest separation efficiency was obtained at 35 °C and 10.34 MPa. At these operating conditions, 92.3% of the butanol present in the feed solution was extracted, and a concentration of 787.5 g·L(-1) of butanol in the extract was obtained, starting from a feed solution of 20 g·L(-1). Selectivity was calculated from experimental data, concluding that our column performs much better than a single equilibrium stage. When adding ethanol and acetone to the feed solution, ethanol was detected in the water-rich fraction (raffinate), whereas the highest concentration of acetone was found in the butanol rich fraction (extract).

  17. Recovery of Butanol by Counter-Current Carbon Dioxide Fractionation with its Potential Application to Butanol Fermentation

    Directory of Open Access Journals (Sweden)

    Miriam Solana

    2016-06-01

    Full Text Available A counter-current CO2 fractionation method was applied as a mean to recover n-butanol and other compounds that are typically obtained from biobutanol fermentation broth from aqueous solutions. The influence of operating variables, such as solvent-to-feed ratio, temperature, pressure and feed solution composition was experimentally studied in terms of separation efficiency, butanol removal rate, total removal and butanol concentration in the extract at the end of the continuous cycle. With respect to the temperature and pressure conditions investigated, results show that the highest separation efficiency was obtained at 35 °C and 10.34 MPa. At these operating conditions, 92.3% of the butanol present in the feed solution was extracted, and a concentration of 787.5 g·L−1 of butanol in the extract was obtained, starting from a feed solution of 20 g·L−1. Selectivity was calculated from experimental data, concluding that our column performs much better than a single equilibrium stage. When adding ethanol and acetone to the feed solution, ethanol was detected in the water-rich fraction (raffinate, whereas the highest concentration of acetone was found in the butanol rich fraction (extract.

  18. Semi-industrial isolation of salicin and amygdalin from plant extracts using slow rotary counter-current chromatography.

    Science.gov (United States)

    Du, Qizhen; Jerz, Gerold; Ha, Yangchun; Li, Lei; Xu, Yuanjin; Zhang, Qi; Zheng, Qunxiong; Winterhalter, Peterb; Ito, Yoichiro

    2005-05-13

    Salicin in the bark extract of Salix alba and amygdalin in the fruit extract of Semen armeniacae were each separated by slow rotary counter-current chromatography (SRCCC). The apparatus was equipped with a 40-L column made of 17 mm i.d. convoluted Teflon tubing. A 500g amount of crude extract containing salicin at 13.5% was separated yielding 63.5 g of salicin at 95.3% purity in 20h using methyl tert-butyl ether-l-butanol (1:3) saturated by methanol-water (1:5) as a stationary phase and methanol-water (1:5) saturated by methyl tert-butyl ether-1-butanol (1:3) as a mobile phase. A 400g amount of crude extract containing amygdalin at 55.3% was isolated to yield 221.2g of amygdalin at 94.1% purity in 19h using ethyl acetate-1-butanol (1:2) saturated by water as a stationary phase and water saturated by ethyl acetate-1-butanol (1:2) as a mobile phase. The flow rate of the mobile phase was 50 ml/min. The results show that industrial SRCCC separation of salicin and amygdalin is feasible using a larger column at a higher flow rate of the mobile phase.

  19. High-speed optical frequency-domain imaging

    OpenAIRE

    Yun, S. H.; Tearney, G. J.; Boer; Iftimia, N. V.; Bouma, B. E.

    2003-01-01

    We demonstrate high-speed, high-sensitivity, high-resolution optical imaging based on optical frequency-domain interferometry using a rapidly-tuned wavelength-swept laser. We derive and show experimentally that frequency-domain ranging provides a superior signal-to-noise ratio compared with conventional time-domain ranging as used in optical coherence tomography. A high sensitivity of −110 dB was obtained with a 6 mW source at an axial resolution of 13.5 µm and an A-line rate of 15.7 kHz, rep...

  20. High Speed Video Applications In The Pharmaceutical Industry

    Science.gov (United States)

    Stapley, David

    1985-02-01

    The pursuit of quality is essential in the development and production of drugs. The pursuit of excellence is relentless, a never ending search. In the pharmaceutical industry, we all know and apply wide-ranging techniques to assure quality production. We all know that in reality none of these techniques are perfect for all situations. We have all experienced, the damaged foil, blister or tube, the missing leaflet, the 'hard to read' batch code. We are all aware of the need to supplement the traditional techniques of fault finding. This paper shows how high speed video systems can be applied to fully automated filling and packaging operations as a tool to aid the company's drive for high quality and productivity. The range of products involved totals some 350 in approximately 3,000 pack variants, encompassing creams, ointments, lotions, capsules, tablets, parenteral and sterile antibiotics. Pharmaceutical production demands diligence at all stages, with optimum use of the techniques offered by the latest technology. Figure 1 shows typical stages of pharmaceutical production in which quality must be assured, and highlights those stages where the use of high speed video systems have proved of value to date. The use of high speed video systems begins with the very first use of machine and materials: commissioning and validation, (the term used for determining that a process is capable of consistently producing the requisite quality) and continues to support inprocess monitoring, throughout the life of the plant. The activity of validation in the packaging environment is particularly in need of a tool to see the nature of high speed faults, no matter how infrequently they occur, so that informed changes can be made precisely and rapidly. The prime use of this tool is to ensure that machines are less sensitive to minor variations in component characteristics.

  1. Improved pulse laser ranging algorithm based on high speed sampling

    Science.gov (United States)

    Gao, Xuan-yi; Qian, Rui-hai; Zhang, Yan-mei; Li, Huan; Guo, Hai-chao; He, Shi-jie; Guo, Xiao-kang

    2016-10-01

    Narrow pulse laser ranging achieves long-range target detection using laser pulse with low divergent beams. Pulse laser ranging is widely used in military, industrial, civil, engineering and transportation field. In this paper, an improved narrow pulse laser ranging algorithm is studied based on the high speed sampling. Firstly, theoretical simulation models have been built and analyzed including the laser emission and pulse laser ranging algorithm. An improved pulse ranging algorithm is developed. This new algorithm combines the matched filter algorithm and the constant fraction discrimination (CFD) algorithm. After the algorithm simulation, a laser ranging hardware system is set up to implement the improved algorithm. The laser ranging hardware system includes a laser diode, a laser detector and a high sample rate data logging circuit. Subsequently, using Verilog HDL language, the improved algorithm is implemented in the FPGA chip based on fusion of the matched filter algorithm and the CFD algorithm. Finally, the laser ranging experiment is carried out to test the improved algorithm ranging performance comparing to the matched filter algorithm and the CFD algorithm using the laser ranging hardware system. The test analysis result demonstrates that the laser ranging hardware system realized the high speed processing and high speed sampling data transmission. The algorithm analysis result presents that the improved algorithm achieves 0.3m distance ranging precision. The improved algorithm analysis result meets the expected effect, which is consistent with the theoretical simulation.

  2. Micro Mirrors for High-speed Laser Deflection and Patterning

    Science.gov (United States)

    Schenk, Harald; Grahmann, Jan; Sandner, Thilo; Wagner, Michael; Dauderstädt, Ulrike; Schmidt, Jan-Uwe

    This paper focuses on high-speed optical MEMS Scanners and Micro Mirror Arrays. Devices supporting spot/pixel rateshigher than 10 Mpixel/s are considered and discussed regarding limits and possibilities to further improve speed and optical properties. Several variants of both types, developed by our group, are presented. Scanning Micro Mirrors with frequencies up to 100 kHz enable spot rates of up to 130 Mpixels / s at 650 nm. Bragg-coatings enable high power applications up to 20 W (beam ø2 mm). Challenges like static and dynamic mirror planariy are discussed. A 29-kHz-scanner for laser projection serves as application example. Highly parallel operated Micro Mirror Arrays extend pattern speed to 10 Gpixel / s including analog grey scaling. Irradiation tests prove stable operation of the mirrors at DUV. Prospects regarding optical planarity and high reflective coatings are discussed. By means of two examples, laser patterning of semiconductor masks and laser patterning of Printed Circuit Boards, properties of the spatial light modulators are presented. The two device classes are compared regarding spot/pixel rate and frequency. The comparison includes representative MEMS device examples from literature.

  3. Research of inverse mathematical model to high-speed trains

    Institute of Scientific and Technical Information of China (English)

    朱涛; 肖守讷; 马卫华; 阳光武

    2014-01-01

    Operation safety and stability of the train mainly depend on the interaction between the wheel and rail. Knowledge of wheel/rail contact force is important for vehicle control systems that aim to enhance vehicle stability and passenger safety. Since wheel/rail contact forces of high-speed train are very difficult to measure directly, a new estimation process for wheel/rail contact forces was introduced in this work. Based on the state space equation, dynamic programming methods and the Bellman principle of optimality, the main theoretical derivation of the inversion mathematical model was given. The new method overcomes the weakness of large fluctuations which exist in current inverse techniques. High-speed vehicle was chosen as the research object, accelerations of axle box as input conditions, 10 degrees of freedom vertical vibration model and 17 degrees of freedom lateral vibration model were established, respectively. Under 250 km/h, the vertical and lateral wheel/rail forces were identified. From the time domain and frequency domain, the comparison of the results between inverse and SIMPACK models were given. The results show that the inverse mathematical model has high precision for inversing the wheel/rail contact forces of an operation high-speed vehicle.

  4. Thermal analysis of high speed permanent magnetic generator

    Institute of Scientific and Technical Information of China (English)

    LI WeiLi; ZHANG XiaoChen; CHENG ShuKang; CAO JunCi; ZHANG YiHuang

    2012-01-01

    High-speed permanent magnetic generators (HSPMG) are common and important power generation equipments used in distributed generation systems.A 100 kW level HSPMG is investigated in this paper,and it is fluid-thermal coupling analyzed.The transient 2D electromagnetic field while machine is under rated operating is analyzed by using the time-stepping FEM,from which the electromagnetic performances and the loss distributions are obtained.Then,an analysis model for fluid-solid temperature field analysis is established.Taking losses as the distributed heat sources,the 3D thermal field is coupling calculated.The variations of heat transfer coefficient and temperature of fluid in stator grooves along the axial direction,as well as the whole region 3D temperature distribution in HSPMG are obtained.Then,considering the variations of heat sources distributions and heat transfer conditions,3D temperature fields of HSPMG operating under different speeds are calculated,and the influences of machine operating speed on the HSPMG thermal performance are studied,based on which,the functions of machine temperature with operating speed and stator windings resistance are proposed.The obtained conclusions may provide a useful reference for the design and research of HSPMG.

  5. High speed multiplier using Nikhilam Sutra algorithm of Vedic mathematics

    Science.gov (United States)

    Pradhan, Manoranjan; Panda, Rutuparna

    2014-03-01

    This article presents the design of a new high-speed multiplier architecture using Nikhilam Sutra of Vedic mathematics. The proposed multiplier architecture finds out the compliment of the large operand from its nearest base to perform the multiplication. The multiplication of two large operands is reduced to the multiplication of their compliments and addition. It is more efficient when the magnitudes of both operands are more than half of their maximum values. The carry save adder in the multiplier architecture increases the speed of addition of partial products. The multiplier circuit is synthesised and simulated using Xilinx ISE 10.1 software and implemented on Spartan 2 FPGA device XC2S30-5pq208. The output parameters such as propagation delay and device utilisation are calculated from synthesis results. The performance evaluation results in terms of speed and device utilisation are compared with earlier multiplier architecture. The proposed design has speed improvements compared to multiplier architecture presented in the literature.

  6. From selective tidal transport to counter-current swimming during watershed colonisation: an impossible step for young-of-the-year catadromous fish?

    Directory of Open Access Journals (Sweden)

    Trancart T.

    2014-01-01

    Full Text Available During watershed colonisation by catadromous species, two main phases have been identified: tidal estuary crossing and non-tidal river colonisation. Fishes use selective tidal-stream transport (STST during the first phase of this colonisation, and counter-current swimming during the second phase. Therefore, catadromous species have to achieve a behavioural shift, from STST to constant counter-current swimming. This has not yet been observed, and the location and period of this shift is still unknown. Our experimental protocol aimed to mimic the spatial progression of crossing the tidal limit within a 3-week experiment. Two catadromous fishes, thinlip mullets and European eels, were initially subjected to current reversal every 6.2 h during the first week. A gradual tidal distortion was performed during the second week, and fishes were submitted to a unidirectional water current during the third week. Our results reveal that all catadromous species use STST as far as possible within the tidal limit. At this point, in this experimental study, no young-of-the-year (YOY fishes shifted from STST to constant counter-current swimming. This confirms that the behavioural shift occurs later, and that the second part of the upstream migration, counter-current progression, is performed by larger, older fishes and not YOY fishes.

  7. Characterizing pyrotechnic igniter output with high-speed schlieren imaging

    Science.gov (United States)

    Skaggs, M. N.; Hargather, M. J.; Cooper, M. A.

    2017-01-01

    Small-scale pyrotechnic igniter output has been characterized using a high-speed schlieren imaging system for observing critical features of the post-combustion flow. The diagnostic, with laser illumination, was successfully applied towards the quantitative characterization of the output from Ti/KClO_4 and TiH_{1.65}/KClO_4 pyrotechnic igniters. The high-speed image sequences showed shock motion, burned gas expansion, and particle motion. A statistical-based analysis methodology for tracking the full-field shock motion enabled straightforward comparisons across the experimental parameters of pyrotechnic material and initial density. This characterization of the mechanical energy of the shock front within the post-combustion environment is a necessary addition to the large body of literature focused on pyrotechnic combustion behavior within the powder bed. Ultimately, understanding the role that the combustion behavior has on the resulting multiphase environment is required for tailored igniter development and comparative performance assessments.

  8. Numerical Simulation for Ventilated Supercavitation High Speed Underwater Vehicle

    Institute of Scientific and Technical Information of China (English)

    YANG Wu-gang; YANG Zhen-cai; CHU Yan; DENG Qiu-xia; LI Ya-rong; ZHANG Yu-wen

    2009-01-01

    Supercavitation is a revolutionary technique to achieve high drag reduction for underwater vehicle. It can help us to break through the conventional speed barrier. This article presents a numerical algorithm for ventilated supercavitation flow field based on mixture multiphase flow model, briefs the calculation results and compares them with that tested in high-speed water tunnel and towing tank. The mathematical model, its numerical calculation method, computational region and boundary conditions are discussed in detail. Some pertinent nondimensional parameters about the ventilated supercavitation, such as geometrical configuration of supercavity, drag coefficient and ventilation rate are investigated. Reynolds number is selected to predict gas ventilation rate instead of Froude number. Finally, based on the test and simulation results, a semi-empirical formula of the ventilation rate estimation suitable for different conical angle caritators is proposed.

  9. High Speed Photography What Role Does It Play In Mining?

    Science.gov (United States)

    Crosby, William A.

    1987-09-01

    High speed photography is being employed to help improve the efficiency of a number of different mining activities. Its principal use, however, is as an aid in the optimization of blasting operations. Blasts are commonly of very short duration and great benefit can thus be gained by being able to observe the events at a suitably selected slow motion over an extended period of time. This paper presents an overview of some of the high speed photographic applications in both surface and underground operations using qualitative and quantitative techniques. The primary use is the direct photography of the blast, the analysis of the resulting films representing the bulk of the optimization work. Other applications are designed to check out individual blast components, particularly evaluating blast tamping, and actual delay element times for such accessories as detonating relays, down-the-hole delays and other delaying and initiating systems.

  10. Photonic Technologies for Ultra-High-Speed Information Highways

    DEFF Research Database (Denmark)

    Bouchoule, S; Lèfevre, R.; Legros, E.;

    1999-01-01

    The ACTS project HIGHWAY (AC067) addresses promising ultra-high speed optoelectronic components and system technologies for 40 Gbit/s time-division-multiplexed (TDM) transport systems. Advanced 40 Gbit/s TDM system lab demonstrators are to be realized and tested over installed field fiber testbed....... This paper reviews the current status of 40 Gbit/s TDM components and subsystem technologies achieved in HIGHWAY. The results of HIGHWAY 40 Gbit/s TDM systems and field tests will be reported in a subsequent paper. (C) 1999 Academic Press.......The ACTS project HIGHWAY (AC067) addresses promising ultra-high speed optoelectronic components and system technologies for 40 Gbit/s time-division-multiplexed (TDM) transport systems. Advanced 40 Gbit/s TDM system lab demonstrators are to be realized and tested over installed field fiber testbeds...

  11. Soliton-based ultra-high speed optical communications

    Indian Academy of Sciences (India)

    Akira Hasegawa

    2001-11-01

    Multi-terabit/s, ultra-high speed optical transmissions over several thousands kilometers on fibers are becoming a reality. Most use RZ (Return to Zero) format in dispersion-managed fibers. This format is the only stable waveform in the presence of fiber Kerr nonlinearity and dispersion in all optical transmission lines with loss compensated by periodic amplifications. The nonlinear Schrödinger equation assisted by the split step numerical solutions is commonly used as the master equation to describe the information transfer in optical fibers. All these facts are the outcome of research on optical solitons in fibers in spite of the fact that the commonly used RZ format is not always called a soliton format. The overview presented here attempts to incorporate the role of soliton-based communications research in present day ultra-high speed communications.

  12. Corrosion Inhibition of High Speed Steel by Biopolymer HPMC Derivatives

    Directory of Open Access Journals (Sweden)

    Shih-Chen Shi

    2016-07-01

    Full Text Available The corrosion inhibition characteristics of the derivatives of biopolymer hydroxypropyl methylcellulose (HPMC, hydroxypropyl methylcellulose phthalate (HPMCP, and hydroxypropyl methylcellulose acetate succinate (HPMCAS film are investigated. Based on electrochemical impedance spectroscopic measurements and potentiodynamic polarization, the corrosion inhibition performance of high speed steel coated with HPMC derivatives is evaluated. The Nyquist plot and Tafel polarization demonstrate promising anti-corrosion performance of HPMC and HPMCP. With increasing film thickness, both materials reveal improvement in corrosion inhibition. Moreover, because of a hydrophobic surface and lower moisture content, HPMCP shows better anti-corrosion performance than HPMCAS. The study is of certain importance for designing green corrosion inhibitors of high speed steel surfaces by the use of biopolymer derivatives.

  13. High Speed Reconfigurable FFT Design by Vedic Mathematics

    CERN Document Server

    Raman, Ashish; Sarin, R K

    2010-01-01

    The Fast Fourier Transform (FFT) is a computationally intensive digital signal processing (DSP) function widely used in applications such as imaging, software-defined radio, wireless communication, instrumentation. In this paper, a reconfigurable FFT design using Vedic multiplier with high speed and small area is presented. Urdhava Triyakbhyam algorithm of ancient Indian Vedic Mathematics is utilized to improve its efficiency. In the proposed architecture, the 4x4 bit multiplication operation is fragmented reconfigurable FFT modules. The 4x4 multiplication modules are implemented using small 2x2bit multipliers. Reconfigurability at run time is provided for attaining power saving. The reconfigurable FFT has been designed, optimized and implemented on an FPGA based system. This reconfigurable FFT is having the high speed and small area as compared to the conventional FFT.

  14. High-speed Integrated Circuits for electrical/Optical Interfaces

    DEFF Research Database (Denmark)

    Jespersen, Christoffer Felix

    2008-01-01

    This thesis is a continuation of the effort to increase the bandwidth of communicationnetworks. The thesis presents the results of the design of several high-speed electrical ircuits for an electrical/optical interface. These circuits have been a contribution to the ESTA project in collaboration ...... as examples. Finally, it is concluded that the VIP-2 process is suitable technology for creating circuits for 100 Gb/s communication networks. Keywords: Indium Phosphide (InP), DHBT, VCO, Colpitt, Static Divider, CDR, PLL, Transceiver...... represents the avant-garde of InP technology, with ft and fmax well above 300 GHz. Principles of high speed design are presented and described as a useful background before proceeding to circuits. A static divider is used as an example to illustrate many of the design principles. Theory and fundamentals...

  15. High speed single charge coupled device Cranz-Schardin camera

    Science.gov (United States)

    Deblock, Y.; Ducloux, O.; Derbesse, L.; Merlen, A.; Pernod, P.

    2007-03-01

    This article describes an ultrahigh speed visualization system based on a miniaturization of the Cranz-Schardin principle. It uses a set of high power light emitting diodes (LEDs) (Golden Dragon) as the light source and a highly sensitive charge coupled device (CCD) camera for reception. Each LED is fired in sequence and images the refraction index variation between two relay lenses, on a partial region of a CCD image sensor. The originality of this system consists in achieving several images on a single CCD during a frame time. The number of images is 4. The time interval between successive firings determines the speed of the imaging system. This time lies from 100nsto10μs. The light pulse duration lies from 100nsto10μs. The principle and the optical and electronic parts of such a system are described. As an example, some images of acoustic waves propagating in water are presented.

  16. High-speed measurement of firearm primer blast waves

    CERN Document Server

    Courtney, Michael; Eng, Jonathan; Courtney, Amy

    2012-01-01

    This article describes a method and results for direct high-speed measurements of firearm primer blast waves employing a high-speed pressure transducer located at the muzzle to record the blast pressure wave produced by primer ignition. Key findings are: 1) Most of the lead styphnate based primer models tested show 5.2-11.3% standard deviation in the magnitudes of their peak pressure. 2) In contrast, lead-free diazodinitrophenol (DDNP) based primers had standard deviations of the peak blast pressure of 8.2-25.0%. 3) Combined with smaller blast waves, these large variations in peak blast pressure of DDNP-based primers led to delayed ignition and failure to fire in brief field tests.

  17. High-Speed Coherent Raman Fingerprint Imaging of Biological Tissues

    CERN Document Server

    Camp, Charles H; Heddleston, John M; Hartshorn, Christopher M; Walker, Angela R Hight; Rich, Jeremy N; Lathia, Justin D; Cicerone, Marcus T

    2014-01-01

    We have developed a coherent Raman imaging platform using broadband coherent anti-Stokes Raman scattering (BCARS) that provides an unprecedented combination of speed, sensitivity, and spectral breadth. The system utilizes a unique configuration of laser sources that probes the Raman spectrum over 3,000 cm$^{-1}$ and generates an especially strong response in the typically weak Raman "fingerprint" region through heterodyne amplification of the anti-Stokes photons with a large nonresonant background (NRB) while maintaining high spectral resolution of $<$ 13 cm$^{-1}$. For histology and pathology, this system shows promise in highlighting major tissue components in a non-destructive, label-free manner. We demonstrate high-speed chemical imaging in two- and three-dimensional views of healthy murine liver and pancreas tissues and interfaces between xenograft brain tumors and the surrounding healthy brain matter.

  18. High speed sub-micrometric microscopy using optical polymer microlens

    Institute of Scientific and Technical Information of China (English)

    X.H.Zeng; J.Plain; S.Jradi; P.Renaud Goud; R.Deturche; P.Royer; R.Bachelot

    2009-01-01

    We report the high speed scanning submicronic microscopy (SSM) using a low cost polymer microlens integrated at the extremity of an optical fiber.These microlenses are fabricated by a free-radical photopolymerization method.Using a polymer microlens with a radius of curvature of 250 nm,a sub-micrometric gold pattern is imaged experimentally by SSM.Different distances between the tip and the sample are used with a high scanning speed of 200 cm/s.In particular,metallic absorption contrasts are described with an optical spatial resolution of 250 nm at the wavelength of 532 nm.Moreover,finite-difference time-domain (FDTD) simulations concerning the focal lengths of microlenses with different geometries and heights support the experimental data.

  19. High-speed measurement of rifle primer blast waves

    CERN Document Server

    Courtney, Michael

    2011-01-01

    This article describes a method and results for direct high-speed measurements of rifle primer blast waves employing a high-speed pressure transducer located at the muzzle to record the blast pressure wave produced by primer ignition. Our key findings are: 1) Most of the primer models tested show 5-12% standard deviation in the magnitudes of their peak pressure. 2) For most primer types tested, peak pressure magnitudes are well correlated with measured primer masses so that significant reductions in standard deviation are expected to result from sorting primers by mass. 3) A range of peak pressures from below 200 psi to above 500 psi is available in different primer types.

  20. Nanocrystalline Ni-Co Alloy Synthesis by High Speed Electrodeposition

    Directory of Open Access Journals (Sweden)

    Jamaliah Idris

    2013-01-01

    Full Text Available Electrodeposition of nanocrystals is economically and technologically viable production path for the synthesis of pure metals and alloys both in coatings and bulk form. The study presents nanocrystalline Ni-Co alloy synthesis by high speed electrodeposition. Nanocrystalline Ni-Co alloys coatings were prepared by direct current (DC and deposited directly on steel and aluminum substrates without any pretreatment, using high speed electrodeposition method. The influence of the electrolysis parameters, such as cathodic current density and temperature at constant pH, on electrodeposition and microstructure of Ni-Co alloys were examined. A homogeneous surface morphology was obtained at all current densities of the plated samples, and it was evident that the current density and temperature affect the coating thickness of Ni-Co alloy coatings.

  1. High-speed imaging polarimetry using liquid crystal modulators

    Directory of Open Access Journals (Sweden)

    Ambs P.

    2010-06-01

    Full Text Available This paper deals with dynamic polarimetric imaging techniques. The basics of modern polarimetry have been known for one and a half century, but no practical high-speed implementation providing the full polarization information is currently available. Various methods are reviewed which prove to be a trade-off between the complexity of the optical set-up and the amount of polarimetric information they provide (ie the number of components of the Stokes vector. Techniques using liquid crystal devices, incepted in the late 1990's, are emphasized. Optical set-ups we implemented are presented. We particularly focus on high-speed techniques (i.e. faster than 200 Hz using ferroelectric liquid crystal devices.

  2. High speed preprocessing in real time telemetry systems

    Science.gov (United States)

    Strock, O. J.; O'Brien, Michael

    A versatile high-speed preprocessor, the EMR 8715, is described which is used as a closed-coupled input device for the host computer in a telemetry system. Much of the data and time merging, number conversion, floating-point processing, and data distribution are performed by the system, reducing the host load. The EMR 8715 allows a choice of serial processing, parallel processing, or a combination of the two, on a measurement-by-measurement basis.

  3. High Speed Friction Microscopy and Nanoscale Friction Coefficient Mapping

    OpenAIRE

    Bosse, James L.; Lee, Sungjun; Huey, Bryan D; Andersen, Andreas Sø; Sutherland, Duncan S

    2014-01-01

    As mechanical devices in the nano/micro length scale are increasingly employed, it is crucial to understand nanoscale friction and wear especially at technically relevant sliding velocities. Accordingly, a novel technique has been developed for Friction Coefficient Mapping (FCM), leveraging recent advances in high speed AFM. The technique efficiently acquires friction versus force curves based on a sequence of images at a single location, each with incrementally lower loads. As a result, true...

  4. A new approach of high speed cutting modelling: SPH method

    OpenAIRE

    LIMIDO, Jérôme; Espinosa, Christine; Salaün, Michel; Lacome, Jean-Luc

    2006-01-01

    The purpose of this study is to introduce a new approach of high speed cutting numerical modelling. A lagrangian Smoothed Particle Hydrodynamics (SPH) based model is carried out using the Ls-Dyna software. SPH is a meshless method, thus large material distortions that occur in the cutting problem are easily managed and SPH contact control permits a “natural” workpiece/chip separation. Estimated chip morphology and cutting forces are compared to machining dedicated code results and experimenta...

  5. SPH method applied to high speed cutting modelling

    OpenAIRE

    LIMIDO, Jérôme; Espinosa, Christine; Salaün, Michel; Lacome, Jean-Luc

    2007-01-01

    The purpose of this study is to introduce a new approach of high speed cutting numerical modelling. A Lagrangian smoothed particle hydrodynamics (SPH)- based model is arried out using the Ls-Dyna software. SPH is a meshless method, thus large material distortions that occur in the cutting problem are easily managed and SPH contact control permits a "natural" workpiece/chip separation. The developed approach is compared to machining dedicated code results and experimental data. The SPH cutting...

  6. NASA/GE Collaboration on Open Rotors - High Speed Testing

    Science.gov (United States)

    VanZante, Dale E.

    2011-01-01

    A low-noise open rotor system is being tested in collaboration with General Electric and CFM International, a 50/50 joint company between Snecmaand GE. Candidate technologies for lower noise will be investigated as well as installation effects such as pylon integration. Current test status for the 8x6 SWT high speed testing is presented as well as future scheduled testing which includes the FAA/CLEEN test entry. The tunnel blockage and propeller thrust calibration configurations are shown.

  7. Instrumentation for propulsion systems development. [high speed fans and turbines

    Science.gov (United States)

    Warshawsky, I.

    1978-01-01

    Apparatus and techniques developed or used by NASA-Lewis to make steady state or dynamic measurements of gas temperature, pressure, and velocity and of the temperature, tip clearance, and vibration of the blades of high-speed fans or turbines are described. The advantages and limitations of each instrument and technique are discussed and the possibility of modifying them for use in developing various propulsion systems is suggested.

  8. Beijing-Tianjin Intercity High-speed Line

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    @@ Ever since 2003, under the guidance of the scientific development concept and in line with the decisions and deployments made by the Party Central Committee and the State Council, China Railways has eagerly taken the golden opportunity for development, to facilitate the implementation of the Mid-term and Long-term Railway Network Development Program, and so it has achieved bumper significant accomplishments in the modernization progress, with Beijing-Tianjin Intercity High-speed Line as one of the exemplary representatives.

  9. Study on Electromagnetic Interference of high-speed railway EMU

    OpenAIRE

    Cheng, Qiang; Liu, Jin-Jiang; Cheng, Ning

    2013-01-01

    Electromagnetic radiation generated by pantograph-catenaries detachment is one of the inevitable problems with the development of high-speed railway this paper is focusing on the generating mechanism and characteristics of electromagnetic noise caused by pantograph-catenaries system. Based on previous research, we build an integrated model of catenaries and locomotive system, and study the electromagnetic disturbance characteristics using software FEKO. The simulation experiment results in th...

  10. Gearbox Reliability Collaborative High-Speed Shaft Calibration

    Energy Technology Data Exchange (ETDEWEB)

    Keller, J.; McNiff, B.

    2014-09-01

    Instrumentation has been added to the high-speed shaft, pinion, and tapered roller bearing pair of the Gearbox Reliability Collaborative gearbox to measure loads and temperatures. The new shaft bending moment and torque instrumentation was calibrated and the purpose of this document is to describe this calibration process and results, such that the raw shaft bending and torque signals can be converted to the proper engineering units and coordinate system reference for comparison to design loads and simulation model predictions.

  11. High Speed Area Efficient 8-point FFT using Vedic Multiplier

    Directory of Open Access Journals (Sweden)

    Avneesh Kumar Mishra

    2014-12-01

    Full Text Available A high speed fast fourier transform (FFT design by using three algorithm is presented in this paper. In algorithm 3, 4-bit Vedic multiplier based technique are used in FFT. In this technique used in three 4-bit ripple carry adder and four 2*2 Vedic multiplier. The main parameter of this paper is number of slice, 4-input LUTS and maximum combinational path delay were calculate.

  12. Determination of aminocresol isomers by high-speed liquid chromatography.

    Science.gov (United States)

    Sakurai, H; Kito, M

    Aminocresol isomers (4-hydroxy-m-toluidine [II], 3-hydroxy-p-toluidine [II], 2-hydroxy-p-toluidine [III]) and p-aminophenol have been separated and determined by a high-speed liquid Chromatographie method. Since this method is applicable in aqueous media, it was used to investigate the suitability of a haemin-cysteine system as a model for the cytochrome P-450 mono-oxygenase system, by determination of the [I], [II], [III] and p-aminophenol formed.

  13. Wetting dynamics at high values of contact line speed

    OpenAIRE

    Пономарев, К. О.; Феоктистов, Дмитрий Владимирович; Орлова, Евгения Георгиевна

    2015-01-01

    Experimental results analyses of dynamic contact angle change under the conditions of substrate wetting by distilled water at high values of the contact line speed was conducted. Three spreading modes for copper substrates with different roughness were selected: drop formation, spreading and equilibrium contact angle formation. Peculiarity of droplet spreading on superhydrophobic surface is found. It consists in a monotonic increase of the advancing dynamic contact angle. The effect of the dr...

  14. High Speed White Dwarf Asteroseismology with the Herty Hall Cluster

    Science.gov (United States)

    Gray, Aaron; Kim, A.

    2012-01-01

    Asteroseismology is the process of using observed oscillations of stars to infer their interior structure. In high speed asteroseismology, we complete that by quickly computing hundreds of thousands of models to match the observed period spectra. Each model on a single processor takes five to ten seconds to run. Therefore, we use a cluster of sixteen Dell Workstations with dual-core processors. The computers use the Ubuntu operating system and Apache Hadoop software to manage workloads.

  15. Florida Turbine Technology (FTT). High Speed Machining of IN100

    Science.gov (United States)

    2006-06-01

    which burnish the surface and develop the fine finish for which deep hole gun drilling is known. Gun drilling was developed for use in drilling of...current process in place to manufacture the rotor shaft. The NCDMM will evaluate methods of manufacturing a .250” diameter hole , 4.0 inches deep in the...forged IN100 material. The hole will need to maintain a geometric tolerance of .002” true position. The NCDMM will also evaluate methods for High Speed

  16. Engineering models of high speed penetration into geological shields

    Science.gov (United States)

    Ben-Dor, Gabi; Dubinsky, Anatoly; Elperin, Tov

    2014-03-01

    The survey is dedicated to approximate empirical and analytical models which were suggested for describing high-speed penetration into geological shields. This review differs from the previously published reviews on this topic in the following respects: (i) includes a large number of models; (ii) describes models suggested during recent years; (iii) much attention is given to models which have been originally published in Russian and are not well known in the West. References list includes 81 items.

  17. Analysis of OFDM Applied to Powerline High Speed Digital Communication

    Institute of Scientific and Technical Information of China (English)

    ZHUANG Jian; YANG Gong-xu

    2003-01-01

    The low voltage powerline is becoming a powerful solution to home network, building automation, and internet access as a result of its wide distribution, easy access and little maintenance. The character of powerline channel is very complicated because it is an open net. This article analysed the character of the powerline channel,introduced the basics of OFDM(Orthogonal Frequency Division Multiplexing), and studied the OFDM applied into powerline high speed digital communication.

  18. Picosecond Semiconductor Lasers For Characterizing High-Speed Image Shutters

    Science.gov (United States)

    Pagano, T. S.; Janson, F. J.; Yates, G. J.; Jaramillo, S. A.

    1986-01-01

    A portable system that utilizes solid state electronic timing circuits and a pulsed semiconductor laser for characterizing the optical gate sequence of high-speed image shutters, including microchannel-plate intensifier tubes (MCPTs), and silicon-intensified target vidicons (SITVs), is described and compared to earlier methods of characterization. Gate sequences obtained using the system and streak camera data of the semiconductor laser pulse are presented, with a brief discussion of the electronic delay timing and avalanche circuits used in the system.

  19. Shape optimization of high-speed penetrators: a review

    Science.gov (United States)

    Ben-Dor, Gabi; Dubinsky, Anatoly; Elperin, Tov

    2012-12-01

    In spite of a large number of publications on shape optimization of penetrating projectiles there are no dedicated surveys of these studies. The goal of the present review is to close this gap. The review includes more than 50 studies published since 1980 and devoted to solving particular problems of shape optimization of high-speed penetrators. We analyze publications which employed analytical and numerical method for shape optimization of high-speed penetrators against concrete, metal, fiber-reinforced plastic laminate and soil shields. We present classification of the mathematical models used for describing interaction between a penetrator and a shield. The reviewed studies are summarized in the table where we display the following information: the model; indicate whether the model accounts for or neglects friction at the surface of penetrator; criterion for optimization (depth of penetration into a semi-infinite shield, ballistic limit velocity for a shield having a finite thickness, several criteria); class of considered shapes of penetrators (bodies of revolution, different classes of 3-D bodies, etc.); method of solution (analytical or numerical); in comments we present additional information on formulation of the optimization problem. The survey also includes discussion on certain methodological facets in formulating shape optimization problems for high-speed penetrators.

  20. Numerical Simulation of a Planing Vessel at High Speed

    Institute of Scientific and Technical Information of China (English)

    Yumin Su; Qingtong Chen; Hailong Shen; Wei Lu

    2012-01-01

    Planing vessels are applied widely in civil and military situations.Due to their high speed,the motion of planning vessels is complex.In order to predict the motion of planning vessels,it is important to analyze the hydrodynamic performance of planning vessels at high speeds.The computational fluid dynamic method (CFD) has been proposed to calculate hydrodynamic performance of planning vessels.However,in most traditional CFD approaches,model tests or empirical formulas are needed to obtain the running attitude of the planing vessels before calculation.This paper presents a new CFD method to calculate hydrodynamic forces of planing vessels.The numerical method was based on Reynolds-Averaged Navier-Stokes (RANS)equations.The volume of fluid (VOF) method and the six-degrees-of-freedom equation were applied.An effective process was introduced to solve the numerical divergence problem in numerical simulation.Compared with experimental results,numerical simulation results indicate that both the running attitude and hydrodynamic performance can be predicted well at high speeds.

  1. Double Helical Gear Performance Results in High Speed Gear Trains

    Science.gov (United States)

    Handschuh, Robert F.; Ehinger, Ryan; Sinusas, Eric; Kilmain, Charles

    2010-01-01

    The operation of high speed gearing systems in the transmissions of tiltrotor aircraft has an effect on overall propulsion system efficiency. Recent work has focused on many aspects of high-speed helical gear trains as would be used in tiltrotor aircraft such as operational characteristics, comparison of analytical predictions to experimental data and the affect of superfinishing on transmission performance. Baseline tests of an aerospace quality system have been conducted in the NASA Glenn High-Speed Helical Gear Train Test Facility and have been described in earlier studies. These earlier tests had utilized single helical gears. The results that will be described in this study are those attained using double helical gears. This type of gear mesh can be configured in this facility to either pump the air-oil environment from the center gap between the meshing gears to the outside of tooth ends or in the reverse direction. Tests were conducted with both inward and outward air-oil pumping directions. Results are compared to the earlier baseline results of single helical gears.

  2. High speed turboprop aeroacoustic study (counterrotation). Volume 1: Model development

    Science.gov (United States)

    Whitfield, C. E.; Mani, R.; Gliebe, P. R.

    1990-01-01

    The isolated counterrotating high speed turboprop noise prediction program was compared with model data taken in the GE Aircraft Engines Cell 41 anechoic facility, the Boeing Transonic Wind Tunnel, and in NASA-Lewis' 8x6 and 9x15 wind tunnels. The predictions show good agreement with measured data under both low and high speed simulated flight conditions. The installation effect model developed for single rotation, high speed turboprops was extended to include counterotation. The additional effect of mounting a pylon upstream of the forward rotor was included in the flow field modeling. A nontraditional mechanism concerning the acoustic radiation from a propeller at angle of attach was investigated. Predictions made using this approach show results that are in much closer agreement with measurement over a range of operating conditions than those obtained via traditional fluctuating force methods. The isolated rotors and installation effects models were combines into a single prediction program, results of which were compared with data taken during the flight test of the B727/UDF engine demonstrator aircraft. Satisfactory comparisons between prediction and measured data for the demonstrator airplane, together with the identification of a nontraditional radiation mechanism for propellers at angle of attack are achieved.

  3. On the reversed Brayton cycle with high speed machinery

    Energy Technology Data Exchange (ETDEWEB)

    Backman, J.

    1996-12-31

    This work was carried out in the laboratory of Fluid Dynamics, at Lappeenranta University of Technology during the years 1991-1996. The research was a part of larger high speed technology development research. First, there was the idea of making high speed machinery applications with the Brayton cycle. There was a clear need to deepen the knowledge of the cycle itself and to make a new approach in the field of the research. Also, the removal of water from the humid air seemed very interesting. The goal of this work was to study methods of designing high speed machinery for the reversed Brayton cycle, from theoretical principles to practical applications. The reversed Brayton cycle can be employed as an air dryer, a heat pump or a refrigerating machine. In this research the use of humid air as a working fluid has an environmental advantage, as well. A new calculation method for the Brayton cycle is developed. In this method especially the expansion process in the turbine is important because of the condensation of the water vapour in the humid air. This physical phenomena can have significant effects on the level of performance of the application. Also, the influence of calculating the process with actual, achievable process equipment efficiencies is essential for the development of future machinery. The above theoretical calculations are confirmed with two different laboratory prototypes. (53 refs.)

  4. A high-speed interconnect network using ternary logic

    DEFF Research Database (Denmark)

    Madsen, Jens Kargaard; Long, S. I.

    1995-01-01

    This paper describes the design and implementation of a high-speed interconnect network (ICN) for a multiprocessor system using ternary logic. By using ternary logic and a fast point-to-point communication technique called STARI (Self-Timed At Receiver's Input), the communication between the proc......This paper describes the design and implementation of a high-speed interconnect network (ICN) for a multiprocessor system using ternary logic. By using ternary logic and a fast point-to-point communication technique called STARI (Self-Timed At Receiver's Input), the communication between...... the processors is free of clock skew and insensitive to any delay differences in buffers and wires. In addition, the number of signal wires and pins are reduced by 50 percent in comparison with a similar binary implementation. The ICN architecture is based on a crossbar topology and the high-speed part consists...... of two LSI GaAs chips, Interface and Crossbar, which were implemented in a 0.8 μm MESFET process. In a 4×4 ICN, communication at 300 Mbit/s per wire was demonstrated, which is twice as fast as pure synchronous and four times faster than pure asynchronous communication in the specific test set-up...

  5. High-speed imaging of blood splatter patterns

    Energy Technology Data Exchange (ETDEWEB)

    McDonald, T.E.; Albright, K.A.; King, N.S.P.; Yates, G.J. (Los Alamos National Lab., NM (United States)); Levine, G.F. (California Dept. of Justice, Sacramento, CA (United States). Bureau of Forensic Services)

    1993-01-01

    The interpretation of blood splatter patterns is an important element in reconstructing the events and circumstances of an accident or crime scene. Unfortunately, the interpretation of patterns and stains formed by blood droplets is not necessarily intuitive and study and analysis are required to arrive at a correct conclusion. A very useful tool in the study of blood splatter patterns is high-speed photography. Scientists at the Los Alamos National Laboratory, Department of Energy (DOE), and Bureau of Forensic Services, State of California, have assembled a high-speed imaging system designed to image blood splatter patterns. The camera employs technology developed by Los Alamos for the underground nuclear testing program and has also been used in a military mine detection program. The camera uses a solid-state CCD sensor operating at approximately 650 frames per second (75 MPixels per second) with a microchannel plate image intensifier that can provide shuttering as short as 5 ns. The images are captured with a laboratory high-speed digitizer and transferred to an IBM compatible PC for display and hard copy output for analysis. The imaging system is described in this paper.

  6. High-speed imaging of blood splatter patterns

    Energy Technology Data Exchange (ETDEWEB)

    McDonald, T.E.; Albright, K.A.; King, N.S.P.; Yates, G.J. [Los Alamos National Lab., NM (United States); Levine, G.F. [California Dept. of Justice, Sacramento, CA (United States). Bureau of Forensic Services

    1993-05-01

    The interpretation of blood splatter patterns is an important element in reconstructing the events and circumstances of an accident or crime scene. Unfortunately, the interpretation of patterns and stains formed by blood droplets is not necessarily intuitive and study and analysis are required to arrive at a correct conclusion. A very useful tool in the study of blood splatter patterns is high-speed photography. Scientists at the Los Alamos National Laboratory, Department of Energy (DOE), and Bureau of Forensic Services, State of California, have assembled a high-speed imaging system designed to image blood splatter patterns. The camera employs technology developed by Los Alamos for the underground nuclear testing program and has also been used in a military mine detection program. The camera uses a solid-state CCD sensor operating at approximately 650 frames per second (75 MPixels per second) with a microchannel plate image intensifier that can provide shuttering as short as 5 ns. The images are captured with a laboratory high-speed digitizer and transferred to an IBM compatible PC for display and hard copy output for analysis. The imaging system is described in this paper.

  7. High-speed imaging of blood splatter patterns

    Energy Technology Data Exchange (ETDEWEB)

    McDonald, T.E.; Albright, K.A.; King, N.S.P.; Yates, G.J. [Los Alamos National Lab., NM (United States); Levine, G.F. [California Dept. of Justice, Sacramento, CA (United States). Bureau of Forensic Services

    1993-05-01

    The interpretation of blood splatter patterns is an important element in reconstructing the events and circumstances of an accident or crime scene. Unfortunately, the interpretation of patterns and stains formed by blood droplets is not necessarily intuitive and study and analysis are required to arrive at a correct conclusion. A very useful tool in the study of blood splatter patterns is high-speed photography. Scientists at the Los Alamos National Laboratory, Department of Energy (DOE), and Bureau of Forensic Services, State of California, have assembled a high-speed imaging system designed to image blood splatter patterns. The camera employs technology developed by Los Alamos for the underground nuclear testing program and has also been used in a military mine detection program. The camera uses a solid-state CCD sensor operating at approximately 650 frames per second (75 MPixels per second) with a microchannel plate image intensifier that can provide shuttering as short as 5 ns. The images are captured with a laboratory high-speed digitizer and transferred to an IBM compatible PC for display and hard copy output for analysis. The imaging system is described in this paper.

  8. Numerical Simulation of Flow Instabilities in High Speed Multistage Compressors

    Institute of Scientific and Technical Information of China (English)

    JunHu; ThomasPeters; 等

    1999-01-01

    In the present paper,a nonlinear multi“actuator disk” model is proposed to analyze the dynamic behavior of flow instabilities,including rotating stall and surge,in high speed multistage axial compressors.The model describes the duct flow fields using two dimensional,compressible and unsteady Euler equations,and accounts for the influences of downstream plenum and throttle in the system as well.It replaces each blade row of multistage compressore with a disk.For numerical calculations,the time marching procedure,using MacCormack two steps scheme,is used.The main pupose of this paper is to predict the mechanism of two dimensional short wavelength rotating stall inception and the interation between blade rows in high speed multistage compressors.It has been demonstrated that the model has the ability to predict those phenomena,and the results show that some system parameters have a strong effect on the stall features as well.Results for a five stage high speed compressor are analyzed in detail,and comparison with the experimental data demonstrates that the model and calculating results are reliable.

  9. High speed turbulent reacting flows: DNS and LES

    Science.gov (United States)

    Givi, Peyman

    1990-01-01

    Work on understanding the mechanisms of mixing and reaction in high speed turbulent reacting flows was continued. Efforts, in particular, were concentrated on taking advantage of modern computational methods to simulate high speed turbulent flows. In doing so, two methodologies were used: large eddy simulations (LES) and direct numerical simulations (DNS). In the work related with LES the objective is to study the behavior of the probability density functions (pdfs) of scalar properties within the subgrid in reacting turbulent flows. The data base obtained by DNS for a detailed study of the pdf characteristics within the subgrid was used. Simulations are performed for flows under various initializations to include the effects of compressibility on mixing and chemical reactions. In the work related with DNS, a two-dimensional temporally developing high speed mixing layer under the influence of a second-order non-equilibrium chemical reaction of the type A + B yields products + heat was considered. Simulations were performed with different magnitudes of the convective Mach numbers and with different chemical kinetic parameters for the purpose of examining the isolated effects of the compressibility and the heat released by the chemical reactions on the structure of the layer. A full compressible code was developed and utilized, so that the coupling between mixing and chemical reactions is captured in a realistic manner.

  10. The Interaction of High-Speed Turbulence with Flames: Turbulent Flame Speed

    CERN Document Server

    Poludnenko, Alexei Y; 10.1016/j.combustflame.2010.09.002

    2011-01-01

    (Abridged) Direct numerical simulations of the interaction of a premixed flame with driven, subsonic, homogeneous, isotropic, Kolmogorov-type turbulence in an unconfined system are used to study the mechanisms determining the turbulent flame speed, S_T, in the thin reaction zone regime. High intensity turbulence is considered with the r.m.s. velocity 35 times the laminar flame speed, S_L, resulting in the Damkohler number Da = 0.05. Here we show that: (1) The flame brush has a complex internal structure, in which the isosurfaces of higher fuel mass fractions are folded on progressively smaller scales. (2) Global properties of the turbulent flame are best represented by the structure of the region of peak reaction rate, which defines the flame surface. (3) In the thin reaction zone regime, S_T is predominantly determined by the increase of the flame surface area, A_T, caused by turbulence. (4) The observed increase of S_T relative to S_L exceeds the corresponding increase of A_T relative to the surface area of...

  11. Development of High-speed Machining Database with Case-based Reasoning

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Applying high-speed machining technology in shop floor has many benefits, such as manufacturing more accurate parts with better surface finishes. The selection of the appropriate machining parameters plays a very important role in the implementation of high-speed machining technology. The case-based reasoning is used in the developing of high-speed machining database to overcome the shortage of available high-speed cutting parameters in machining data handbooks and shop floors. The high-speed machining data...

  12. High-speed seatbelt pretensioner loading of the abdomen.

    Science.gov (United States)

    Foster, Craig D; Hardy, Warren N; Yang, King H; King, Albert I; Hashimoto, Syuzo

    2006-11-01

    This study characterizes the response of the human cadaver abdomen to high-speed seatbelt loading using pyrotechnic pretensioners. A test apparatus was developed to deliver symmetric loading to the abdomen using a seatbelt equipped with two low-mass load cells. Eight subjects were tested under worst-case scenario, out-of-position (OOP) conditions. A seatbelt was placed at the level of mid-umbilicus and drawn back along the sides of the specimens, which were seated upright using a fixed-back configuration. Penetration was measured by a laser, which tracked the anterior aspect of the abdomen, and by high-speed video. Additionally, aortic pressure was monitored. Three different pretensioner designs were used, referred to as system A, system B and system C. The B and C systems employed single pretensioners. The A system consisted of two B system pretensioners. The vascular systems of the subjects were perfused. Peak anterior abdominal loads due to the seatbelt ranged from 2.8 kN to 10.1 kN. Peak abdominal penetration ranged from 49 mm to 138 mm. Peak penetration speed ranged from 4.0 m/s to 13.3 m/s. Three cadavers sustained liver injury: one AIS 2, and two AIS 3. Cadaver abdominal response corridors for the A and B system pretensioners are proposed. The results are compared to the data reported by Hardy et al. (2001) and Trosseille et al. (2002).

  13. A second-generation high speed civil transport: Stingray

    Science.gov (United States)

    Engdahl, Sean; Lopes, Kevin; Ngan, Angelen; Perrin, Joseph; Phipps, Marcus; Westman, Blake; Yeo, Urn

    1992-01-01

    The Stingray is the second-generation High Speed Civil Transport (HSCT) designed for the 21st Century. This aircraft is designed to be economically viable and environmentally sound transportation competitive in markets currently dominated by subsonic aircraft such as the Boeing 747 and upcoming McDonnell Douglas MD-12. With the Stringray coming into service in 2005, a ticket price of 21 percent over current subsonic airlines will cover operational costs with a 10 percent return on investment. The cost per aircraft will be $202 million with the Direct Operating Cost equal to $0.072 per mile per seat. This aircraft has been designed to be a realistic aircraft that can be built within the next ten to fifteen years. There was only one main technological improvement factor used in the design, that being for the engine specific fuel consumption. The Stingray, therefore, does not rely on technology that does not exist. The Stingray will be powered by four mixed flow turbofans that meet both nitrous oxide emissions and FAR 36 Stage 3 noise regulations. It will carry 250 passengers a distance of 5200 nautical miles at a speed of Mach 2.4. The shape of the Stingray, while optimized for supersonic flight, is compatible with all current airline facilities in airports around the world. As the demand for economical, high-speed flight increases, the Stingray will be ready and able to meet those demands.

  14. High speed digital holographic interferometry for hypersonic flow visualization

    Science.gov (United States)

    Hegde, G. M.; Jagdeesh, G.; Reddy, K. P. J.

    2013-06-01

    Optical imaging techniques have played a major role in understanding the flow dynamics of varieties of fluid flows, particularly in the study of hypersonic flows. Schlieren and shadowgraph techniques have been the flow diagnostic tools for the investigation of compressible flows since more than a century. However these techniques provide only the qualitative information about the flow field. Other optical techniques such as holographic interferometry and laser induced fluorescence (LIF) have been used extensively for extracting quantitative information about the high speed flows. In this paper we present the application of digital holographic interferometry (DHI) technique integrated with short duration hypersonic shock tunnel facility having 1 ms test time, for quantitative flow visualization. Dynamics of the flow fields in hypersonic/supersonic speeds around different test models is visualized with DHI using a high-speed digital camera (0.2 million fps). These visualization results are compared with schlieren visualization and CFD simulation results. Fringe analysis is carried out to estimate the density of the flow field.

  15. Decomposition of forging die for high speed machining

    CERN Document Server

    Tapie, Laurent

    2009-01-01

    Today's forging die manufacturing process must be adapted to several evolutions in machining process generation: CAD/CAM models, CAM software solutions and High Speed Machining (HSM). In this context, the adequacy between die shape and HSM process is in the core of machining preparation and process planning approaches. This paper deals with an original approach of machining preparation integrating this adequacy in the main tasks carried out. In this approach, the design of the machining process is based on two levels of decomposition of the geometrical model of a given die with respect to HSM cutting conditions (cutting speed and feed rate) and technological constrains (tool selection, features accessibility). This decomposition assists machining assistant to generate an HSM process. The result of this decomposition is the identification of machining features.

  16. Unwinding of a carbon nanoscroll due to high speed rotation

    Directory of Open Access Journals (Sweden)

    Hang Yin

    2015-10-01

    Full Text Available A carbon nanoscroll (CNS can be formed easily by rolling a graphene sheet around a carbon nanotube (CNT [Zhang and Li, 2010, APL, 97, 081909]. When the CNS is driven by the rotary CNT to rotate at a high speed, the attractive interaction within the CNS or between the CNS and CNT is crippled by the centrifugal force on the CNS. The unwinding of CNS is triggered when the kinetic energy increment approaches to the variation of interaction energy of the system during CNS formation. Numerical experiments also indicate that the unwinding of CNS happens earlier when the CNT has a higher rotational speed or the system is at a higher temperature.

  17. Marshall Space Flight Center High Speed Turbopump Bearing Test Rig

    Science.gov (United States)

    Gibson, Howard; Moore, Chip; Thom, Robert

    2000-01-01

    The Marshall Space Flight Center has a unique test rig that is used to test and develop rolling element bearings used in high-speed cryogenic turbopumps. The tester is unique in that it uses liquid hydrogen as the coolant for the bearings. This test rig can simulate speeds and loads experienced in the Space Shuttle Main Engine turbopumps. With internal modifications, the tester can be used for evaluating fluid film, hydrostatic, and foil bearing designs. At the present time, the test rig is configured to run two ball bearings or a ball and roller bearing, both with a hydrostatic bearing. The rig is being used to evaluate the lifetimes of hybrid bearings with silicon nitride rolling elements and steel races.

  18. High Speed Gear Sized and Configured to Reduce Windage Loss

    Science.gov (United States)

    Kunz, Robert F. (Inventor); Medvitz, Richard B. (Inventor); Hill, Matthew John (Inventor)

    2013-01-01

    A gear and drive system utilizing the gear include teeth. Each of the teeth has a first side and a second side opposite the first side that extends from a body of the gear. For each tooth of the gear, a first extended portion is attached to the first side of the tooth to divert flow of fluid adjacent to the body of the gear to reduce windage losses that occur when the gear rotates. The gear may be utilized in drive systems that may have high rotational speeds, such as speeds where the tip velocities are greater than or equal to about 68 m/s. Some embodiments of the gear may also utilize teeth that also have second extended portions attached to the second sides of the teeth to divert flow of fluid adjacent to the body of the gear to reduce windage losses that occur when the gear rotates.

  19. High-speed spectral tuning CARS microscopy using AOTF laser

    Science.gov (United States)

    Hashimoto, Mamoru; Iwatsuka, Junichi; Niioka, Hirohiko; Araki, Tsutomu

    2012-03-01

    We have developed a high speed spectral tuning CARS microscopy system using a mode-locked Ti:Sapphire laser with an acousto-optic tunable filter (AOTF) in the cavity. Since the wavelength of the laser is tunable with the applied radio frequency to the AOTF, the wavelength is electrically tunable.The pulse duration of the laser is about 10 ps, tunable range is 800 nm to 930 nm, and the tuning speed is ms order. The laser is synchronized with another mode-locked Ti:Sapphire laser laser our own method using a balance cross-correlator and phase lock loop technique. The synchronized lasers are used for light source of multi-focus CARS microscopy system using a microlens array scanner, and the hyperspectral imaging of adipocyte cells is demonstrated.

  20. High Speed Boosted Cmos Differential Logic for Ripple Carry Adders

    Directory of Open Access Journals (Sweden)

    Meenu Roy,

    2014-01-01

    Full Text Available This paper describes a high speed boosted CMOS differential logic which is applicable in Ripple Carry Adders. The proposed logic operating with supply voltage approaching the MOS threshold voltage. The logic style improves switching speed by boosting the gate-source voltage of transistors along timing critical signal path. It allows a single boosting circuit to be shared by complementary outputs as a result the area overhead also minimizes. As compared to the conventional logic gates the EDP (energy delay product is improved. The test sets of logic gates and adders where designed in tsmc0.18μm of Mentor Graphics EDA tool. The experimental result for Ripple Carry Adders using the proposed logic style revealed that the addition time is reduced as compared with the conventional CMOS circuits.