A novel dual-valve sequential injection manifold (DV-SIA) for automated liquid-liquid extraction. Application for the determination of picric acid.

PubMed

Skrlíková, Jana; Andruch, Vasil; Sklenárová, Hana; Chocholous, Petr; Solich, Petr; Balogh, Ioseph S

2010-05-07

A novel dual-valve sequential injection system (DV-SIA) for online liquid-liquid extraction which resolves the main problems of LLE utilization in SIA has been designed. The main idea behind this new design was to construct an SIA system by connecting two independent units, one for aqueous-organic mixture flow and the second specifically for organic phase flow. As a result, the DV-SIA manifold consists of an Extraction unit and a Detection unit. Processing a mixture of aqueous-organic phase in the Extraction unit and a separated organic phase in the Detection unit solves the problems associated with the change of phases having different affinities to the walls of the Teflon tubing used in the SI-system. The developed manifold is a simple, user-friendly and universal system built entirely from commercially available components. The system can be used for a variety of samples and organic solvents and is simple enough to be easily handled by operators less familiar with flow systems. The efficiency of the DV-SIA system is demonstrated by the extraction of picric acid in the form of an ion associate with 2-[2-(4-methoxy-phenylamino)-vinyl]-1,3,3-trimethyl-3H-indolium reagent, with subsequent spectrophotometric detection. The suggested DV-SIA concept can be expected to stimulate new experiments in analytical laboratories and can be applied to the elaboration of procedures for the determination of other compounds extractable by organic solvents. It could thus form a basis for the design of simple, single-purpose commercial instruments used in LLE procedures. 2010 Elsevier B.V. All rights reserved.

Iodine speciation in coastal and inland bathing waters and seaweeds extracts using a sequential injection standard addition flow-batch method.

PubMed

Santos, Inês C; Mesquita, Raquel B R; Bordalo, Adriano A; Rangel, António O S S

2015-02-01

The present work describes the development of a sequential injection standard addition method for iodine speciation in bathing waters and seaweeds extracts without prior sample treatment. Iodine speciation was obtained by assessing the iodide and iodate content, the two inorganic forms of iodine in waters. For the determination of iodide, an iodide ion selective electrode (ISE) was used. The indirect determination of iodate was based on the spectrophotometric determination of nitrite (Griess reaction). For the iodate measurement, a mixing chamber was employed (flow batch approach) to explore the inherent efficient mixing, essential for the indirect determination of iodate. The application of the standard addition method enabled detection limits of 0.14 µM for iodide and 0.02 µM for iodate, together with the direct introduction of the target water samples, coastal and inland bathing waters. The results obtained were in agreement with those obtained by ICP-MS and a colorimetric reference procedure. Recovery tests also confirmed the accuracy of the developed method which was effectively applied to bathing waters and seaweed extracts. Copyright © 2014 Elsevier B.V. All rights reserved.

[Pollution characteristics and ecological risk assessment of heavy metals in surface sediments of Qingshan Reservoir in Lin' an City, Zhejiang Province of East China].

PubMed

Zhang, Fen; Yang, Chang-Ming; Pan, Rui-Jie

2013-09-01

A total of 8 representative surface sediment sampling sites were collected from the Qingshan Reservoir in Lin'an City of Zhejiang Province to investigate the differences in the total concentrations of As, Cr, Cu, Ni, Mn, Pb, and Zn among the sampling sites. The different forms of the heavy metals, i. e., acid soluble, easily reducible, easily oxidizable, and residual, were determined by BCR sequential extraction method, and the pollution degrees and potential ecological risk, of the heavy metals in the surface sediments at different sampling sites of the Reservoir were assessed by using geo-accumulation index (I(geo)) and Hakanson potential ecological risk index. There existed obvious spatial differences in the total concentrations of the heavy metals in the surface sediments of the Reservoir. The sampling sites nearby the estuaries of the tributaries flowing through downtowns and heavy industrial parks to the Reservoir had obviously higher heavy metals concentrations in surface sediments, as compared to the other sampling sites. In the sediments, Mn was mainly in acid extractable form, Cu and Pb were mainly in reducible form, and As was mainly in residual form. The surface sediments at the sampling sites nearby the estuaries of the tributaries flowing through downtowns to the Reservoir had higher proportions of acid extractable and reducibles forms of the heavy metals, which would have definite potential toxic risk to aquatic organisms. Among the 7 heavy metals in the surface sediments, As showed the highest pollution degree, followed by Cu, Ni, Mn, Pb, and Zn, which were at moderate pollution degree, while Cr was at non-pollution degree, with relatively low potential ecological risk. Through the comparison of the sampling sites, it was observed that the surface sediments at the sites nearby the estuaries of Jinxi River and Hengxi River flowing through downtowns and heavy industrial parks to the Reservoir showed obviously higher heavy metals pollution degree and potential ecological risk.

Sequential extraction procedure for determination of uranium, thorium, radium, lead and polonium radionuclides by alpha spectrometry in environmental samples

NASA Astrophysics Data System (ADS)

Oliveira, J. M.; Carvalho, F. P.

2006-01-01

A sequential extraction technique was developed and tested for common naturally-occurring radionuclides. This technique allows the extraction and purification of uranium, thorium, radium, lead, and polonium radionuclides from the same sample. Environmental materials such as water, soil, and biological samples can be analyzed for those radionuclides without matrix interferences in the quality of radioelement purification and in the radiochemical yield. The use of isotopic tracers (232U, 229Th, 224Ra, 209Po, and stable lead carrier) added to the sample in the beginning of the chemical procedure, enables an accurate control of the radiochemical yield for each radioelement. The ion extraction procedure, applied after either complete dissolution of the solid sample with mineral acids or co-precipitation of dissolved radionuclide with MnO2 for aqueous samples, includes the use of commercially available pre-packed columns from Eichrom® and ion exchange columns packed with Bio-Rad resins, in altogether three chromatography columns. All radioactive elements but one are purified and electroplated on stainless steel discs. Polonium is spontaneously plated on a silver disc. The discs are measured using high resolution silicon surface barrier detectors. 210Pb, a beta emitter, can be measured either through the beta emission of 210Bi, or stored for a few months and determined by alpha spectrometry through the in-growth of 210Po. This sequential extraction chromatography technique was tested and validated with the analysis of certified reference materials from the IAEA. Reproducibility was tested through repeated analysis of the same homogeneous material (water sample).

Dillenia suffruticosa exhibited antioxidant and cytotoxic activity through induction of apoptosis and G2/M cell cycle arrest.

PubMed

Armania, Nurdin; Yazan, Latifah Saiful; Musa, Siti Noorhidayah; Ismail, Intan Safinar; Foo, Jhi Biau; Chan, Kim Wei; Noreen, Husain; Hisyam, Abdul Hamid; Zulfahmi, Said; Ismail, Maznah

2013-03-27

Dillenia suffruticosa (Family: Dilleniaceae) locally known as Simpoh air has been reported to be used traditionally to treat cancerous growth. Therefore, the present study was attempted to investigate the antioxidant and cytotoxic properties of different parts (root, flower, fruit and leaf) of D. suffruticosa extracts. In this study, direct solvent extraction (aqueous and methanol) from different parts of D. suffruticosa (root, flower, fruit and leaf) were carried out. Antioxidant activities of D. suffruticosa extract were determined by using DPPH, ABTS FRAP and β-carotene bleaching assays. Cytotoxicity and cell cycle arrest of the active extract were determined using MTT assay and flow cytometer, respectively. Sequential solvent extraction (hexane, DCM, EtOAc, and MeOH) were also carried out in root of D. suffruticosa to further evaluate the antioxidant and cytotoxic activity of the different solvent extracts. Methanol (MeOH) root extract showed the highest TPC, antioxidant and cytotoxic activities (especially towards HeLa) compared to others (P<0.05). Based on the results, sequential solvent extraction (hexane, DCM, EtOAc and MeOH) was carried out in the roots of D. suffruticosa. MeOH extract exhibited the highest antioxidant activities among others and significantly correlated (P<0.05) with TPC, suggesting the important contribution of phenolic compounds to its antioxidant activity. On the other hand, the DCM and EtOAc exhibited higher cytotoxic activity to selected cancer cells (HeLa, MCF-7, MDA-MB-231, A549 and HT29) compared to others. In short, there is no established correlation between antioxidant and cytotoxic activities of D. suffruticosa extracts indicating that an agent with high antioxidant activities will not necessarily possesses good cytotoxic activities in return. Qualitative phytochemical screening of D. suffruticosa extracts suggested the presence of saponins, triterpenes, sterols, and polyphenolic compounds which are believed to contribute to the cytotoxic activities. It is suggested that the cytotoxicity of the active extracts in HeLa was due to the induction of apoptosis and cell cycle arrest at G2/M. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

Transportable Maps Software. Volume I.

DTIC Science & Technology

1982-07-01

being collected at the beginning or end of the routine. This allows the interaction to be followed sequentially through its steps by anyone reading the...flow is either simple sequential , simple conditional (the equivalent of ’if-then-else’), simple iteration (’DO-loop’), or the non-linear recursion...input raster images to be in the form of sequential binary files with a SEGMENTED record type. The advantage of this form is that large logical records

Assessment of arrays of in-stream tidal turbines in the Bay of Fundy.

PubMed

Karsten, Richard; Swan, Amanda; Culina, Joel

2013-02-28

Theories of in-stream turbines are adapted to analyse the potential electricity generation and impact of turbine arrays deployed in Minas Passage, Bay of Fundy. Linear momentum actuator disc theory (LMADT) is combined with a theory that calculates the flux through the passage to determine both the turbine power and the impact of rows of turbine fences. For realistically small blockage ratios, the theory predicts that extracting 2000-2500 MW of turbine power will result in a reduction in the flow of less than 5 per cent. The theory also suggests that there is little reason to tune the turbines if the blockage ratio remains small. A turbine array model is derived that extends LMADT by using the velocity field from a numerical simulation of the flow through Minas Passage and modelling the turbine wakes. The model calculates the resulting speed of the flow through and around a turbine array, allowing for the sequential positioning of turbines in regions of strongest flow. The model estimates that over 2000 MW of power is possible with only a 2.5 per cent reduction in the flow. If turbines are restricted to depths less than 50 m, the potential power generation is reduced substantially, down to 300 MW. For large turbine arrays, the blockage ratios remain small and the turbines can produce maximum power with a drag coefficient equal to the Betz-limit value.

Spectroscopic Doppler analysis for visible-light optical coherence tomography

NASA Astrophysics Data System (ADS)

Shu, Xiao; Liu, Wenzhong; Duan, Lian; Zhang, Hao F.

2017-12-01

Retinal oxygen metabolic rate can be effectively measured by visible-light optical coherence tomography (vis-OCT), which simultaneously quantifies oxygen saturation and blood flow rate in retinal vessels through spectroscopic analysis and Doppler measurement, respectively. Doppler OCT relates phase variation between sequential A-lines to the axial flow velocity of the scattering medium. The detectable phase shift is between -π and π due to its periodicity, which limits the maximum measurable unambiguous velocity without phase unwrapping. Using shorter wavelengths, vis-OCT is more vulnerable to phase ambiguity since flow induced phase variation is linearly related to the center wavenumber of the probing light. We eliminated the need for phase unwrapping using spectroscopic Doppler analysis. We split the whole vis-OCT spectrum into a series of narrow subbands and reconstructed vis-OCT images to extract corresponding Doppler phase shifts in all the subbands. Then, we quantified flow velocity by analyzing subband-dependent phase shift using linear regression. In the phantom experiment, we showed that spectroscopic Doppler analysis extended the measurable absolute phase shift range without conducting phase unwrapping. We also tested this method to quantify retinal blood flow in rodents in vivo.

Phased charging and discharging in capacitive desalinatio

DOEpatents

Stadermann, Michael; Qu, Yatian; Santiago, Juan G.; Hemmatifar, Ali

2017-09-12

A system combines complete, ultra-thin cells into a monolithic and robust framework necessary for desalination applications which yields orders of magnitude faster desalination. The electrode pairs are located so that a flow of feed water flows through or around the electrode pairs with the flow perpendicular to sequentially applied electric potentials. The system is controlled to charge the series of electrode pairs sequentially or phased. That means the charging of the second electrode pair is delayed with regard to the charging of the first electrode pair and the charging of a third electrode pair is delayed with respect to the charging of the second electrode pair.

Speckle pattern sequential extraction metric for estimating the focus spot size on a remote diffuse target.

PubMed

Yu, Zhan; Li, Yuanyang; Liu, Lisheng; Guo, Jin; Wang, Tingfeng; Yang, Guoqing

2017-11-10

The speckle pattern (line by line) sequential extraction (SPSE) metric is proposed by the one-dimensional speckle intensity level crossing theory. Through the sequential extraction of received speckle information, the speckle metrics for estimating the variation of focusing spot size on a remote diffuse target are obtained. Based on the simulation, we will give some discussions about the SPSE metric range of application under the theoretical conditions, and the aperture size will affect the metric performance of the observation system. The results of the analyses are verified by the experiment. This method is applied to the detection of relative static target (speckled jitter frequency is less than the CCD sampling frequency). The SPSE metric can determine the variation of the focusing spot size over a long distance, moreover, the metric will estimate the spot size under some conditions. Therefore, the monitoring and the feedback of far-field spot will be implemented laser focusing system applications and help the system to optimize the focusing performance.

XANES Spectroscopic Analysis of Phosphorus Speciation in Alum-Amended Poultry Litter

DOE Office of Scientific and Technical Information (OSTI.GOV)

Seiter,J.; Staats-Borda, K.; Ginder-Vogel, M.

2008-01-01

Aluminum sulfate (alum; Al2(SO4)3{center_dot}14H2O) is used as a chemical treatment of poultry litter to reduce the solubility and release of phosphate, thereby minimizing the impacts on adjacent aquatic ecosystems when poultry litter is land applied as a crop fertilizer. The objective of this study was to determine, through the use of X-ray absorption near edge structure (XANES) spectroscopy and sequential extraction, how alum amendments alter P distribution and solid-state speciation within the poultry litter system. Our results indicate that traditional sequential fractionation procedures may not account for variability in P speciation in heterogeneous animal manures. Analysis shows that NaOH-extracted Pmore » in alum amended litters is predominantly organic ({approx}80%), whereas in the control samples, >60% of NaOH-extracted P was inorganic P. Linear least squares fitting (LLSF) analysis of spectra collected of sequentially extracted litters showed that the P is present in inorganic (P sorbed on Al oxides, calcium phosphates) and organic forms (phytic acid, polyphosphates, and monoesters) in alum- and non-alum-amended poultry litter. When determining land application rates of poultry litter, all of these compounds must be considered, especially organic P. Results of the sequential extractions in conjunction with LLSF suggest that no P species is completely removed by a single extractant. Rather, there is a continuum of removal as extractant strength increases. Overall, alum-amended litters exhibited higher proportions of Al-bound P species and phytic acid, whereas untreated samples contained Ca-P minerals and organic P compounds. This study provides in situ information about P speciation in the poultry litter solid and about P availability in alum- and non-alum-treated poultry litter that will dictate P losses to ground and surface water systems.« less

Development of a standardized sequential extraction protocol for simultaneous extraction of multiple actinide elements

DOE PAGES

Faye, Sherry A.; Richards, Jason M.; Gallardo, Athena M.; ...

2017-02-07

Sequential extraction is a useful technique for assessing the potential to leach actinides from soils; however, current literature lacks uniformity in experimental details, making direct comparison of results impossible. This work continued development toward a standardized five-step sequential extraction protocol by analyzing extraction behaviors of 232Th, 238U, 239,240Pu and 241Am from lake and ocean sediment reference materials. Results produced a standardized procedure after creating more defined reaction conditions to improve method repeatability. A NaOH fusion procedure is recommended following sequential leaching for the complete dissolution of insoluble species.

Sequential injection ionic liquid dispersive liquid-liquid microextraction for thallium preconcentration and determination with flame atomic absorption spectrometry.

PubMed

Anthemidis, Aristidis N; Ioannou, Kallirroy-Ioanna G

2012-08-01

A novel, automatic on-line sequential injection dispersive liquid-liquid microextraction (SI-DLLME) method, based on 1-hexyl-3-methylimidazolium hexafluorophosphate ([Hmim][PF(6)]) ionic liquid as an extractant solvent was developed and demonstrated for trace thallium determination by flame atomic absorption spectrometry. The ionic liquid was on-line fully dispersed into the aqueous solution in a continuous flow format while the TlBr(4)(-) complex was easily migrated into the fine droplets of the extractant due to the huge contact area of them with the aqueous phase. Furthermore, the extractant was simply retained onto the surface of polyurethane foam packed into a microcolumn. No specific conditions like low temperature are required for extractant isolation. All analytical parameters of the proposed method were investigated and optimized. For 15 mL of sample solution, an enhancement factor of 290, a detection limit of 0.86 μg L(-1) and a precision (RSD) of 2.7% at 20.0 μg L(-1) Tl(I) concentration level, was obtained. The developed method was evaluated by analyzing certified reference materials while good recoveries from environmental and biological samples proved that present method was competitive in practical applications.

Inertial navigation sensor integrated obstacle detection system

NASA Technical Reports Server (NTRS)

Bhanu, Bir (Inventor); Roberts, Barry A. (Inventor)

1992-01-01

A system that incorporates inertial sensor information into optical flow computations to detect obstacles and to provide alternative navigational paths free from obstacles. The system is a maximally passive obstacle detection system that makes selective use of an active sensor. The active detection typically utilizes a laser. Passive sensor suite includes binocular stereo, motion stereo and variable fields-of-view. Optical flow computations involve extraction, derotation and matching of interest points from sequential frames of imagery, for range interpolation of the sensed scene, which in turn provides obstacle information for purposes of safe navigation.

Evaluation of sequential extraction procedures for soluble and insoluble hexavalent chromium compounds in workplace air samples.

PubMed

Ashley, Kevin; Applegate, Gregory T; Marcy, A Dale; Drake, Pamela L; Pierce, Paul A; Carabin, Nathalie; Demange, Martine

2009-02-01

Because toxicities may differ for Cr(VI) compounds of varying solubility, some countries and organizations have promulgated different occupational exposure limits (OELs) for soluble and insoluble hexavalent chromium (Cr(VI)) compounds, and analytical methods are needed to determine these species in workplace air samples. To address this need, international standard methods ASTM D6832 and ISO 16740 have been published that describe sequential extraction techniques for soluble and insoluble Cr(VI) in samples collected from occupational settings. However, no published performance data were previously available for these Cr(VI) sequential extraction procedures. In this work, the sequential extraction methods outlined in the relevant international standards were investigated. The procedures tested involved the use of either deionized water or an ammonium sulfate/ammonium hydroxide buffer solution to target soluble Cr(VI) species. This was followed by extraction in a sodium carbonate/sodium hydroxide buffer solution to dissolve insoluble Cr(VI) compounds. Three-step sequential extraction with (1) water, (2) sulfate buffer and (3) carbonate buffer was also investigated. Sequential extractions were carried out on spiked samples of soluble, sparingly soluble and insoluble Cr(VI) compounds, and analyses were then generally carried out by using the diphenylcarbazide method. Similar experiments were performed on paint pigment samples and on airborne particulate filter samples collected from stainless steel welding. Potential interferences from soluble and insoluble Cr(III) compounds, as well as from Fe(II), were investigated. Interferences from Cr(III) species were generally absent, while the presence of Fe(II) resulted in low Cr(VI) recoveries. Two-step sequential extraction of spiked samples with (first) either water or sulfate buffer, and then carbonate buffer, yielded quantitative recoveries of soluble Cr(VI) and insoluble Cr(VI), respectively. Three-step sequential extraction gave excessively high recoveries of soluble Cr(VI), low recoveries of sparingly soluble Cr(VI), and quantitative recoveries of insoluble Cr(VI). Experiments on paint pigment samples using two-step extraction with water and carbonate buffer yielded varying percentages of relative fractions of soluble and insoluble Cr(VI). Sequential extractions of stainless steel welding fume air filter samples demonstrated the predominance of soluble Cr(VI) compounds in such samples. The performance data obtained in this work support the Cr(VI) sequential extraction procedures described in the international standards.

Development of enantioselective chemiluminescence flow- and sequential-injection immunoassays for alpha-amino acids.

PubMed

Silvaieh, Hossein; Schmid, Martin G; Hofstetter, Oliver; Schurig, Volker; Gübitz, Gerald

2002-01-01

The development of an enantioselective flow-through chemiluminescence immunosensor for amino acids is described. The approach is based on a competitive assay using enantioselective antibodies. Two different instrumental approaches, a flow-injection (FIA) and a sequential-injection system (SIA), are used. Compared to the flow-injection technique, the sequential injection-mode showed better repeatability. Both systems use an immunoreactor consisting of a flow cell packed with immobilized haptens. The haptens (4-amino-L- or D-phenylalanine) are immobilized onto a hydroxysuccinimide-activated polymer (Affi-prep 10) via a tyramine spacer. Stereoselective antibodies, raised against 4-amino-L- or D-phenylalanine, are labeled with an acridinium ester. Stereoselective inhibition of binding of the acridinum-labeled antibodies to the immobilized hapten by amino acids takes place. Chiral recognition was observed not only for the hapten molecule but also for a series of different amino acids. One assay cycle including regeneration takes 6:30 min in the FIA mode and 4:40 min in the SIA mode. Using D-phenylalanine as a sample, the detection limit was found to be 6.13 pmol/ml (1.01 ng/ml) for the flow-injection immunoassay (FIIA) and 1.76 pmol/ml (0.29 ng/ml ) for the sequential-injection immunoassay (SIIA) which can be lowered to 0.22 pmol/ml (0.036 ng/ml) or 0.064 pmol/ml (0.01 ng/ml) by using a stopped flow system. The intra-assay repeatability was found to be about 5% RSD and the inter-assay repeatability below 6% (within 3 days).

Metal-organic framework mixed-matrix disks: Versatile supports for automated solid-phase extraction prior to chromatographic separation.

PubMed

Ghani, Milad; Font Picó, Maria Francesca; Salehinia, Shima; Palomino Cabello, Carlos; Maya, Fernando; Berlier, Gloria; Saraji, Mohammad; Cerdà, Víctor; Turnes Palomino, Gemma

2017-03-10

We present for the first time the application of metal-organic framework (MOF) mixed-matrix disks (MMD) for the automated flow-through solid-phase extraction (SPE) of environmental pollutants. Zirconium terephthalate UiO-66 and UiO-66-NH 2 MOFs with different size (90, 200 and 300nm) have been incorporated into mechanically stable polyvinylidene difluoride (PVDF) disks. The performance of the MOF-MMDs for automated SPE of seven substituted phenols prior to HPLC analysis has been evaluated using the sequential injection analysis technique. MOF-MMDs enabled the simultaneous extraction of phenols with the concomitant size exclusion of molecules of larger size. The best extraction performance was obtained using a MOF-MMD containing 90nm UiO-66-NH 2 crystals. Using the selected MOF-MMD, detection limits ranging from 0.1 to 0.2μgL -1 were obtained. Relative standard deviations ranged from 3.9 to 5.3% intra-day, and 4.7-5.7% inter-day. Membrane batch-to-batch reproducibility was from 5.2 to 6.4%. Three different groundwater samples were analyzed with the proposed method using MOF-MMDs, obtaining recoveries ranging from 90 to 98% for all tested analytes. Copyright © 2017 Elsevier B.V. All rights reserved.

Changes in transthoracic impedance during sequential biphasic defibrillation.

PubMed

Deakin, Charles D; Ambler, Jonathan J S; Shaw, Steven

2008-08-01

Sequential monophasic defibrillation reduces transthoracic impedance (TTI) and progressively increases current flow for any given energy level. The effect of sequential biphasic shocks on TTI is unknown. We therefore studied patients undergoing elective cardioversion using a biphasic waveform to establish whether this is a phenomenon seen in the clinical setting. Adults undergoing elective DC cardioversion for atrial flutter or fibrillation received sequential transthoracic shocks using an escalating protocol (70J, 100J, 150J, 200J, and 300J) with a truncated exponential biphasic waveform. TTI was calculated through the defibrillator circuit and recorded electronically. Successful cardioversion terminated further defibrillation shocks. A total of 58 patients underwent elective cardioversion. Cardioversion was successful in 93.1% patients. First shock TTI was 92.2 [52.0-126.0]Omega (n=58) and decreased significantly with each sequential shock. Mean TTI in patients receiving five shocks (n=5) was 85.0Omega. Sequential biphasic defibrillation decreases TTI in a similar manner to that seen with monophasic waveforms. The effect is likely during defibrillation during cardiac arrest by the quick succession in which shocks are delivered and the lack of cutaneous blood flow which limits the inflammatory response. The ability of biphasic defibrillators to adjust their waveform according to TTI is likely to minimise any effect of these findings on defibrillation efficacy.

The application of intraoperative transit time flow measurement to accurately assess anastomotic quality in sequential vein grafting

PubMed Central

Yu, Yang; Zhang, Fan; Gao, Ming-Xin; Li, Hai-Tao; Li, Jing-Xing; Song, Wei; Huang, Xin-Sheng; Gu, Cheng-Xiong

2013-01-01

OBJECTIVES Intraoperative transit time flow measurement (TTFM) is widely used to assess anastomotic quality in coronary artery bypass grafting (CABG). However, in sequential vein grafting, the flow characteristics collected by the conventional TTFM method are usually associated with total graft flow and might not accurately indicate the quality of every distal anastomosis in a sequential graft. The purpose of our study was to examine a new TTFM method that could assess the quality of each distal anastomosis in a sequential graft more reliably than the conventional TTFM approach. METHODS Two TTFM methods were tested in 84 patients who underwent sequential saphenous off-pump CABG in Beijing An Zhen Hospital between April and August 2012. In the conventional TTFM method, normal blood flow in the sequential graft was maintained during the measurement, and the flow probe was placed a few centimetres above the anastomosis to be evaluated. In the new method, blood flow in the sequential graft was temporarily reduced during the measurement by placing an atraumatic bulldog clamp at the graft a few centimetres distal to the anastomosis to be evaluated, while the position of the flow probe remained the same as in the conventional method. This new TTFM method was named the flow reduction TTFM. Graft flow parameters measured by both methods were compared. RESULTS Compared with the conventional TTFM, the flow reduction TTFM resulted in significantly lower mean graft blood flow (P < 0.05); in contrast, yielded significantly higher pulsatility index (P < 0.05). Diastolic filling was not significantly different between the two methods and was >50% in both cases. Interestingly, the flow reduction TTFM identified two defective middle distal anastomoses that the conventional TTFM failed to detect. Graft flows near the defective distal anastomoses were improved substantially after revision. CONCLUSIONS In this study, we found that temporary reduction of graft flow during TTFM seemed to enhance the sensitivity of TTFM to less-than-critical anastomotic defects in a sequential graft and to improve the overall accuracy of the intraoperative assessment of anastomotic quality in sequential vein grafting. PMID:24000314

Atomizing, continuous, water monitoring module

DOEpatents

Thompson, C.V.; Wise, M.B.

1997-07-08

A system for continuously analyzing volatile constituents of a liquid is described. The system contains a pump for continuously pumping the liquid to be tested at a predetermined flow rate into an extracting container through a liquid directing tube having an orifice at one end and positioned to direct the liquid into the extracting container at a flow rate sufficient to atomize the liquid within the extracting container. A continuous supply of helium carrier gas at a predetermined flow rate is directed through a tube into the extracting container and co-mingled with the atomized liquid to extract the volatile constituents contained within the atomized liquid. The helium containing the extracted volatile constituents flows out of the extracting container into a mass spectrometer for an analysis of the volatile constituents of the liquid. 3 figs.

Atomizing, continuous, water monitoring module

DOEpatents

Thompson, Cyril V.; Wise, Marcus B.

1997-01-01

A system for continuously analyzing volatile constituents of a liquid is described. The system contains a pump for continuously pumping the liquid to be tested at a predetermined flow rate into an extracting container through a liquid directing tube having an orifice at one end and positioned to direct the liquid into the extracting container at a flow rate sufficient to atomize the liquid within the extracting container. A continuous supply of helium carrier gas at a predetermined flow rate is directed through a tube into the extracting container and co-mingled with the atomized liquid to extract the volatile constituents contained within the atomized liquid. The helium containing the extracted volatile constituents flows out of the extracting container into a mass spectrometer for an analysis of the volatile constituents of the liquid.

Sequential injection-bead injection-lab-on-valve coupled to high-performance liquid chromatography for online renewable micro-solid-phase extraction of carbamate residues in food and environmental samples.

PubMed

Vichapong, Jitlada; Burakham, Rodjana; Srijaranai, Supalax; Grudpan, Kate

2011-07-01

A sequential injection-bead injection-lab-on-valve system was hyphenated to HPLC for online renewable micro-solid-phase extraction of carbamate insecticides. The carbamates studied were isoprocarb, methomyl, carbaryl, carbofuran, methiocarb, promecarb, and propoxur. LiChroprep(®) RP-18 beads (25-40 μm) were employed as renewable sorbent packing in a microcolumn situated inside the LOV platform mounted above the multiposition valve of the sequential injection system. The analytes sorbed by the microcolumn were eluted using 80% acetonitrile in 0.1% acetic acid before online introduction to the HPLC system. Separation was performed on an Atlantis C-18 column (4.6 × 150 mm, 5 μm) utilizing gradient elution with a flow rate of 1.0 mL/min and a detection wavelength at 270 nm. The sequential injection system offers the means of performing automated handling of sample preconcentration and matrix removal. The enrichment factors ranged between 20 and 125, leading to limits of detection (LODs) in the range of 1-20 μg/L. Good reproducibility was obtained with relative standard deviations of <0.7 and 5.4% for retention time and peak area, respectively. The developed method has been successfully applied to the determination of carbamate residues in fruit, vegetable, and water samples. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

21 CFR 862.2150 - Continuous flow sequential multiple chemistry analyzer for clinical use.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Continuous flow sequential multiple chemistry..., DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES CLINICAL CHEMISTRY AND CLINICAL TOXICOLOGY DEVICES Clinical Laboratory Instruments § 862.2150 Continuous flow sequential multiple chemistry...

21 CFR 862.2150 - Continuous flow sequential multiple chemistry analyzer for clinical use.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Continuous flow sequential multiple chemistry..., DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES CLINICAL CHEMISTRY AND CLINICAL TOXICOLOGY DEVICES Clinical Laboratory Instruments § 862.2150 Continuous flow sequential multiple chemistry...

21 CFR 862.2150 - Continuous flow sequential multiple chemistry analyzer for clinical use.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Continuous flow sequential multiple chemistry..., DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES CLINICAL CHEMISTRY AND CLINICAL TOXICOLOGY DEVICES Clinical Laboratory Instruments § 862.2150 Continuous flow sequential multiple chemistry...

21 CFR 862.2150 - Continuous flow sequential multiple chemistry analyzer for clinical use.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Continuous flow sequential multiple chemistry..., DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES CLINICAL CHEMISTRY AND CLINICAL TOXICOLOGY DEVICES Clinical Laboratory Instruments § 862.2150 Continuous flow sequential multiple chemistry...

21 CFR 862.2150 - Continuous flow sequential multiple chemistry analyzer for clinical use.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Continuous flow sequential multiple chemistry..., DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES CLINICAL CHEMISTRY AND CLINICAL TOXICOLOGY DEVICES Clinical Laboratory Instruments § 862.2150 Continuous flow sequential multiple chemistry...

Identifying High-Rate Flows Based on Sequential Sampling

NASA Astrophysics Data System (ADS)

Zhang, Yu; Fang, Binxing; Luo, Hao

We consider the problem of fast identification of high-rate flows in backbone links with possibly millions of flows. Accurate identification of high-rate flows is important for active queue management, traffic measurement and network security such as detection of distributed denial of service attacks. It is difficult to directly identify high-rate flows in backbone links because tracking the possible millions of flows needs correspondingly large high speed memories. To reduce the measurement overhead, the deterministic 1-out-of-k sampling technique is adopted which is also implemented in Cisco routers (NetFlow). Ideally, a high-rate flow identification method should have short identification time, low memory cost and processing cost. Most importantly, it should be able to specify the identification accuracy. We develop two such methods. The first method is based on fixed sample size test (FSST) which is able to identify high-rate flows with user-specified identification accuracy. However, since FSST has to record every sampled flow during the measurement period, it is not memory efficient. Therefore the second novel method based on truncated sequential probability ratio test (TSPRT) is proposed. Through sequential sampling, TSPRT is able to remove the low-rate flows and identify the high-rate flows at the early stage which can reduce the memory cost and identification time respectively. According to the way to determine the parameters in TSPRT, two versions of TSPRT are proposed: TSPRT-M which is suitable when low memory cost is preferred and TSPRT-T which is suitable when short identification time is preferred. The experimental results show that TSPRT requires less memory and identification time in identifying high-rate flows while satisfying the accuracy requirement as compared to previously proposed methods.

Repeated surveys by acoustic Doppler current profiler for flow and sediment dynamics in a tidal river

USGS Publications Warehouse

Dinehart, R.L.; Burau, J.R.

2005-01-01

A strategy of repeated surveys by acoustic Doppler current profiler (ADCP) was applied in a tidal river to map velocity vectors and suspended-sediment indicators. The Sacramento River at the junction with the Delta Cross Channel at Walnut Grove, California, was surveyed over several tidal cycles in the Fall of 2000 and 2001 with a vessel-mounted ADCP. Velocity profiles were recorded along flow-defining survey paths, with surveys repeated every 27 min through a diurnal tidal cycle. Velocity vectors along each survey path were interpolated to a three-dimensional Cartesian grid that conformed to local bathymetry. A separate array of vectors was interpolated onto a grid from each survey. By displaying interpolated vector grids sequentially with computer animation, flow dynamics of the reach could be studied in three-dimensions as flow responded to the tidal cycle. Velocity streamtraces in the grid showed the upwelling of flow from the bottom of the Sacramento River channel into the Delta Cross Channel. The sequential display of vector grids showed that water in the canal briefly returned into the Sacramento River after peak flood tides, which had not been known previously. In addition to velocity vectors, ADCP data were processed to derive channel bathymetry and a spatial indicator for suspended-sediment concentration. Individual beam distances to bed, recorded by the ADCP, were transformed to yield bathymetry accurate enough to resolve small bedforms within the study reach. While recording velocity, ADCPs also record the intensity of acoustic backscatter from particles suspended in the flow. Sequential surveys of backscatter intensity were interpolated to grids and animated to indicate the spatial movement of suspended sediment through the study reach. Calculation of backscatter flux through cross-sectional grids provided a first step for computation of suspended-sediment discharge, the second step being a calibrated relation between backscatter intensity and sediment concentration. Spatial analyses of ADCP data showed that a strategy of repeated surveys and flow-field interpolation has the potential to simplify computation of flow and sediment discharge through complex waterways. The use of trade, product, industry, or firm names in this report is for descriptive purposes only and does not constitute endorsement of products by the US Government. ?? 2005 Elsevier B.V. All rights reserved.

Kurtosis-Based Blind Source Extraction of Complex Non-Circular Signals with Application in EEG Artifact Removal in Real-Time

PubMed Central

Javidi, Soroush; Mandic, Danilo P.; Took, Clive Cheong; Cichocki, Andrzej

2011-01-01

A new class of complex domain blind source extraction algorithms suitable for the extraction of both circular and non-circular complex signals is proposed. This is achieved through sequential extraction based on the degree of kurtosis and in the presence of non-circular measurement noise. The existence and uniqueness analysis of the solution is followed by a study of fast converging variants of the algorithm. The performance is first assessed through simulations on well understood benchmark signals, followed by a case study on real-time artifact removal from EEG signals, verified using both qualitative and quantitative metrics. The results illustrate the power of the proposed approach in real-time blind extraction of general complex-valued sources. PMID:22319461

Automated solid-phase extraction of phenolic acids using layered double hydroxide-alumina-polymer disks.

PubMed

Ghani, Milad; Palomino Cabello, Carlos; Saraji, Mohammad; Manuel Estela, Jose; Cerdà, Víctor; Turnes Palomino, Gemma; Maya, Fernando

2018-01-26

The application of layered double hydroxide-Al 2 O 3 -polymer mixed-matrix disks for solid-phase extraction is reported for the first time. Al 2 O 3 is embedded in a polymer matrix followed by an in situ metal-exchange process to obtain a layered double hydroxide-Al 2 O 3 -polymer mixed-matrix disk with excellent flow-through properties. The extraction performance of the prepared disks is evaluated as a proof of concept for the automated extraction using sequential injection analysis of organic acids (p-hydroxybenzoic acid, 3,4-dihydroxybenzoic acid, gallic acid) following an anion-exchange mechanism. After the solid-phase extraction, phenolic acids were quantified by reversed-phase high-performance liquid chromatography with diode-array detection using a core-shell silica-C18 stationary phase and isocratic elution (acetonitrile/0.5% acetic acid in pure water, 5:95, v/v). High sensitivity and reproducibility were obtained with limits of detection in the range of 0.12-0.25 μg/L (sample volume, 4 mL), and relative standard deviations between 2.9 and 3.4% (10 μg/L, n = 6). Enrichment factors of 34-39 were obtained. Layered double hydroxide-Al 2 O 3 -polymer mixed-matrix disks had an average lifetime of 50 extractions. Analyte recoveries ranged from 93 to 96% for grape juice and nonalcoholic beer samples. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Simultaneous injection-effective mixing analysis of palladium.

PubMed

Teshima, Norio; Noguchi, Daisuke; Joichi, Yasutaka; Lenghor, Narong; Ohno, Noriko; Sakai, Tadao; Motomizu, Shoji

2010-01-01

A novel concept of simultaneous injection-effective mixing analysis (SIEMA) is proposed, and a SIEMA method applied to the spectrophotometric determination of palladium using a water-soluble chromogenic reagent has been demonstrated. The flow configuration of SIEMA is a hybrid format of flow injection analysis (FIA), sequential injection analysis (SIA) and multicommutation in flow-based analysis. Sample and reagent solutions are aspirated into each holding coil through each solenoid valve by a syringe pump, and then the zones are simultaneously dispensed (injected) into a mixing coil by reversed flow toward a detector through a confluence point. This results in effective mixing and rapid detection with low reagent consumption.

Disposable and removable nucleic acid extraction and purification cartridges for automated flow-through systems

DOEpatents

Regan, John Frederick

2014-09-09

Removable cartridges are used on automated flow-through systems for the purpose of extracting and purifying genetic material from complex matrices. Different types of cartridges are paired with specific automated protocols to concentrate, extract, and purifying pathogenic or human genetic material. Their flow-through nature allows large quantities sample to be processed. Matrices may be filtered using size exclusion and/or affinity filters to concentrate the pathogen of interest. Lysed material is ultimately passed through a filter to remove the insoluble material before the soluble genetic material is delivered past a silica-like membrane that binds the genetic material, where it is washed, dried, and eluted. Cartridges are inserted into the housing areas of flow-through automated instruments, which are equipped with sensors to ensure proper placement and usage of the cartridges. Properly inserted cartridges create fluid- and air-tight seals with the flow lines of an automated instrument.

A mid-infrared flow-through sensor for label-free monitoring of enzyme inhibition.

PubMed

Armenta, S; Tomischko, W; Lendl, B

2008-12-01

Label-free monitoring of acetylcholinesterase (AChE) activity was achieved with a mid-infrared flow-through sensor. The flow-through sensor comprised agarose beads, carrying covalently immobilized AChE, which were placed in a temperature-controlled (37 degrees C) CaF(2) flow cell with an optical path of 60 mum. The sensor was incorporated into a computer-controlled sequential injection (SI) system for automated liquid handling. Different mixtures of enzyme substrate acetylcholine (ACh) and inhibitor (tacrine) were prepared and fed into the flow-through sensor. The flow was stopped as soon as the prepared mixtures reached the sensor. Enzymatic hydrolysis of ACh by AChE was directly monitored as it took place in the flow-through sensor. The inhibition effect of tacrine was calculated from the reaction-induced spectral changes, revealing an important decrease in the activity of AChE, approaching zero when the inhibitor concentration is high enough. The developed mid-infrared flow-through sensor is flexible and can be used to study the inhibitor activity of different target molecules as well as different enzymes.

Improved workflow modelling using role activity diagram-based modelling with application to a radiology service case study.

PubMed

Shukla, Nagesh; Keast, John E; Ceglarek, Darek

2014-10-01

The modelling of complex workflows is an important problem-solving technique within healthcare settings. However, currently most of the workflow models use a simplified flow chart of patient flow obtained using on-site observations, group-based debates and brainstorming sessions, together with historic patient data. This paper presents a systematic and semi-automatic methodology for knowledge acquisition with detailed process representation using sequential interviews of people in the key roles involved in the service delivery process. The proposed methodology allows the modelling of roles, interactions, actions, and decisions involved in the service delivery process. This approach is based on protocol generation and analysis techniques such as: (i) initial protocol generation based on qualitative interviews of radiology staff, (ii) extraction of key features of the service delivery process, (iii) discovering the relationships among the key features extracted, and, (iv) a graphical representation of the final structured model of the service delivery process. The methodology is demonstrated through a case study of a magnetic resonance (MR) scanning service-delivery process in the radiology department of a large hospital. A set of guidelines is also presented in this paper to visually analyze the resulting process model for identifying process vulnerabilities. A comparative analysis of different workflow models is also conducted. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

Kinetics of the water/air phase transition of radon and its implication on detection of radon-in-water concentrations: practical assessment of different on-site radon extraction methods.

PubMed

Schubert, Michael; Paschke, Albrecht; Bednorz, Denise; Bürkin, Walter; Stieglitz, Thomas

2012-08-21

The on-site measurement of radon-in-water concentrations relies on extraction of radon from the water followed by its detection by means of a mobile radon-in-air monitor. Many applications of radon as a naturally occurring aquatic tracer require the collection of continuous radon concentration time series, thus necessitating the continuous extraction of radon either from a permanent water stream supplied by a water pump or directly from a water body or a groundwater monitoring well. Essentially, three different types of extraction units are available for this purpose: (i) a flow-through spray chamber, (ii) a flow-through membrane extraction module, and (iii) a submersible (usually coiled) membrane tube. In this paper we discuss the advantages and disadvantages of these three methodical approaches with particular focus on their individual response to instantaneously changing radon-in-water concentrations. After a concise introduction into theoretical aspects of water/air phase transition kinetics of radon, experimental results for the three types of extraction units are presented. Quantitative suggestions for optimizing the detection setup by increasing the water/air interface and by reducing the air volume circulating through the degassing unit and radon detector are made. It was shown that the flow-through spray chamber and flow-through membrane perform nearly similarly, whereas the submersible membrane tubing has a significantly larger delay in response to concentration changes. The flow-through spray chamber is most suitable in turbid waters and to applications where high flow rates of the water pump stream can be achieved (e.g., where the power supply is not constrained by field conditions). The flow-through membrane is most suited to radon extraction from clear water and in field conditions where the power supply to a water pump is limited, e.g., from batteries. Finally, the submersible membrane tube is most suitable if radon is to be extracted in situ without any water pumping, e.g., in groundwater wells with a low yield, or in long-term time series, in which short-term variations in the radon concentration are of no relevance.

Speciation of chromium (VI) and total chromium determination in welding dust samples by flow-injection analysis coupled to atomic absorption spectrometry.

PubMed

Girard, L; Hubert, J

1996-11-01

We have studied the speciation of chromium (VI) in stainless-steel welding dusts. The approach used for the analysis of Cr(VI) and total Cr relies on a flow-injection analyzer (FIA) equipped with two different sequential detectors. The system measures Cr(VI). by colorimetry (with 1,5-diphenyl carbohydrazide) and total chromium content by flame atomic absorption spectroscopy (AAS). The extraction of the samples of welding-fume dusts is achieved in a buffer solution (acetic acid and sodium acetate at pH 4). This extraction procedure gives a 96% recovery of chromium (VI). The FIA-AAS system that has been described is also more sensitive, has a lower detection limit (0.005 mug ml(-1)) and gives a better precision (< 1%) than other equivalent systems that have been previously described.

Polyport atmospheric gas sampler

DOEpatents

Guggenheim, S. Frederic

1995-01-01

An atmospheric gas sampler with a multi-port valve which allows for multi, sequential sampling of air through a plurality of gas sampling tubes mounted in corresponding gas inlet ports. The gas sampler comprises a flow-through housing which defines a sampling chamber and includes a gas outlet port to accommodate a flow of gases through the housing. An apertured sample support plate defining the inlet ports extends across and encloses the sampling chamber and supports gas sampling tubes which depend into the sampling chamber and are secured across each of the inlet ports of the sample support plate in a flow-through relation to the flow of gases through the housing during sampling operations. A normally closed stopper means mounted on the sample support plate and operatively associated with each of the inlet ports blocks the flow of gases through the respective gas sampling tubes. A camming mechanism mounted on the sample support plate is adapted to rotate under and selectively lift open the stopper spring to accommodate a predetermined flow of gas through the respective gas sampling tubes when air is drawn from the housing through the outlet port.

Sequential microfluidic droplet processing for rapid DNA extraction.

PubMed

Pan, Xiaoyan; Zeng, Shaojiang; Zhang, Qingquan; Lin, Bingcheng; Qin, Jianhua

2011-11-01

This work describes a novel droplet-based microfluidic device, which enables sequential droplet processing for rapid DNA extraction. The microdevice consists of a droplet generation unit, two reagent addition units and three droplet splitting units. The loading/washing/elution steps required for DNA extraction were carried out by sequential microfluidic droplet processing. The movement of superparamagnetic beads, which were used as extraction supports, was controlled with magnetic field. The microdevice could generate about 100 droplets per min, and it took about 1 min for each droplet to perform the whole extraction process. The extraction efficiency was measured to be 46% for λ-DNA, and the extracted DNA could be used in subsequent genetic analysis such as PCR, demonstrating the potential of the device for fast DNA extraction. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Environmentally friendly microwave-assisted sequential extraction method followed by ICP-OES and ion-chromatographic analysis for rapid determination of sulphur forms in coal samples.

PubMed

Mketo, Nomvano; Nomngongo, Philiswa N; Ngila, J Catherine

2018-05-15

A rapid three-step sequential extraction method was developed under microwave radiation followed by inductively coupled plasma-optical emission spectroscopic (ICP-OES) and ion-chromatographic (IC) analysis for the determination of sulphur forms in coal samples. The experimental conditions of the proposed microwave-assisted sequential extraction (MW-ASE) procedure were optimized by using multivariate mathematical tools. Pareto charts generated from 2 3 full factorial design showed that, extraction time has insignificant effect on the extraction of sulphur species, therefore, all the sequential extraction steps were performed for 5 min. The optimum values according to the central composite designs and counter plots of the response surface methodology were 200 °C (microwave temperature) and 0.1 g (coal amount) for all the investigated extracting reagents (H 2 O, HCl and HNO 3 ). When the optimum conditions of the proposed MW-ASE procedure were applied in coal CRMs, SARM 18 showed more organic sulphur (72%) and the other two coal CRMs (SARMs 19 and 20) were dominated by sulphide sulphur species (52-58%). The sum of the sulphur forms from the sequential extraction steps have shown consistent agreement (95-96%) with certified total sulphur values on the coal CRM certificates. This correlation, in addition to the good precision (1.7%) achieved by the proposed procedure, suggests that the sequential extraction method is reliable, accurate and reproducible. To safe-guard the destruction of pyritic and organic sulphur forms in extraction step 1, water was used instead of HCl. Additionally, the notorious acidic mixture (HCl/HNO 3 /HF) was replaced by greener reagent (H 2 O 2 ) in the last extraction step. Therefore, the proposed MW-ASE method can be applied in routine laboratories for the determination of sulphur forms in coal and coal related matrices. Copyright © 2018 Elsevier B.V. All rights reserved.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Faye, Sherry A.; Richards, Jason M.; Gallardo, Athena M.

Sequential extraction is a useful technique for assessing the potential to leach actinides from soils; however, current literature lacks uniformity in experimental details, making direct comparison of results impossible. This work continued development toward a standardized five-step sequential extraction protocol by analyzing extraction behaviors of 232Th, 238U, 239,240Pu and 241Am from lake and ocean sediment reference materials. Results produced a standardized procedure after creating more defined reaction conditions to improve method repeatability. A NaOH fusion procedure is recommended following sequential leaching for the complete dissolution of insoluble species.

Harnessing Thin-Film Continuous-Flow Assembly Lines.

PubMed

Britton, Joshua; Castle, Jared W; Weiss, Gregory A; Raston, Colin L

2016-07-25

Inspired by nature's ability to construct complex molecules through sequential synthetic transformations, an assembly line synthesis of α-aminophosphonates has been developed. In this approach, simple starting materials are continuously fed through a thin-film reactor where the intermediates accrue molecular complexity as they progress through the flow system. Flow chemistry allows rapid multistep transformations to occur via reaction compartmentalization, an approach not amenable to using conventional flasks. Thin film processing can also access facile in situ solvent exchange to drive reaction efficiency, and through this method, α-aminophosphonate synthesis requires only 443 s residence time to produce 3.22 g h(-1) . Assembly-line synthesis allows unprecedented reaction flexibility and processing efficiency. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Sequential ASE extraction of alkylphenols from sediments: Occurrence and environmental implications.

PubMed

Gong, Jian; Xu, Lei; Yang, Yu; Chen, Di-Yun; Ran, Yong

2011-08-30

The occurrence of alkylphenols (APs) including nonylphenol (NP) and octylphenol (OP) in the riverine sediments from the Pearl River Delta (PRD), South China was investigated and compared by Soxhlet extraction (S-APs) with dichloromethane and by sequential accelerated solvent extraction (ASE) (A-APs) with 1:6 toluene/methanol, respectively. Concentrations of OP and NP range from <1 to 463ng/g dw and 31-21,885ng/g dw, respectively, demonstrating that the contamination level of APs in the PRD is one of the highest in the world. Moreover, the A-APs contents are highly significantly related to and on average 1.5 times the S-APs contents. For sequential two ASE extractions, APs in the first extract accounts for 82.2-99.2% of their total contents in the sequential two extractions. The correlation analysis shows that S-APs and A-APs are both significantly associated with the contents of total organic carbon (TOC), suggesting that the variable extraction efficiency of these two methods is related to the presence of condensed organic matter in the sediments. Copyright © 2011 Elsevier B.V. All rights reserved.

SEQUENTIAL EXTRACTIONS FOR PARTITIONING OF ARSENIC ON HYDROUS IRON OXIDES AND IRON SULFIDES

EPA Science Inventory

The objective of this study was to use model solids to test solutions designed to extract arsenic from relatively labile solid phase fractions. The use of sequential extractions provides analytical constraints on the identification of mineral phases that control arsenic mobility...

Phenolic content and antioxidant activity of Hibiscus cannabinus L. seed extracts after sequential solvent extraction.

PubMed

Yusri, Noordin Mohd; Chan, Kim Wei; Iqbal, Shahid; Ismail, Maznah

2012-10-25

A sequential solvent extraction scheme was employed for the extraction of antioxidant compounds from kenaf (Hibiscus cannabinus L.) seeds. Yield of extracts varied widely among the solvents and was the highest for hexane extract (16.6% based on dry weight basis), while water extract exhibited the highest total phenolic content (18.78 mg GAE/g extract), total flavonoid content (2.49 mg RE/g extract), and antioxidant activities (p < 0.05). DPPH and hydroxyl radical scavenging, β-carotene bleaching, metal chelating activity, ferric thiocyanate and thiobarbituric acid reactive substances assays were employed to comprehensively assess the antioxidant potential of different solvent extracts prepared sequentially. Besides water, methanolic extract also exhibited high retardation towards the formation of hydroperoxides and thiobarbituric acid reactive substances in the total antioxidant activity tests (p < 0.05). As conclusion, water and methanol extracts of kenaf seed may potentially serve as new sources of antioxidants for food and nutraceutical applications.

Infiltration Processes and Flow Velocities Across the Landscape: When and Where is Macropore Flow Relevant?

NASA Astrophysics Data System (ADS)

Demand, D.; Blume, T.; Weiler, M.

2017-12-01

Preferential flow in macropores significantly affects the distributions of water and solutes in soil and many studies showed its relevance worldwide. Although some models include this process as a second pore domain, little is known about the spatial patterns and temporal dynamics. For example, while flow in the matrix is usually modeled and parameterized based on soil texture, an influence of texture on non-capillary flow for a given land-use class is poorly understood. To investigate the temporal and spatial dynamics on preferential flow we used a four-year soil moisture dataset from the mesoscale Attert catchment (288 km²) in Luxembourg. This dataset contains time series from 126 soil profiles in different textures and two land-use classes (forest, grassland). The soil moisture probes were installed in 10, 30 and 50 cm depth and measured in a 5-minute temporal resolution. Events were defined by a soil moisture increase higher than the instrument noise after a precipitation sum of more than 1 mm. Precipitation was measured next to the profiles so that each location could be associated to its unique precipitation characteristics. For every event and profile the soil moisture reaction was classified in sequential (ordered by depth) and non-sequential response. A non-sequential soil moisture reaction was used as an indicator of preferential flow. For sequential flow, the velocity was determined by the first reaction between two vertically adjacent sensors. The sensor reaction and wetting front velocity was analyzed in the context of precipitation characteristics and initial soil water content. Grassland sites showed a lower proportion of non-sequential flow than forest sites. For forest, non-sequential response is dependent on texture, rainfall intensity and initial water content. This is less distinct for the grassland sites. Furthermore, sequential reactions show higher flow velocities at sites, which also have high percentage of non-sequential response. In contrast, grassland sites show a more homogenous wetting front independent of soil texture. Compared against common modelling approaches of soil water flow, measured velocities show clear evidence of preferential flow, especially for forest soils. The analysis also shows that vegetation can alter the soil properties above the textural properties alone.

Fractionation and Mobility of Thallium in Volcanic Ashes after Eruption of Eyjafjallajökull (2010) in Iceland.

PubMed

Karbowska, Bozena; Zembrzuski, Wlodzimierz

2016-07-01

Volcanic ash contains thallium (Tl), which is highly toxic to the biosphere. The aim of this study was to determine the Tl concentration in fractions of volcanic ash samples originating from the Eyjafjallajökull volcano. A sequential extraction scheme allowed for a study of element migration in the environment. Differential pulse anodic stripping voltammetry using a flow measuring system was selected as the analytical method to determine Tl content. The highest average content of Tl in volcanic ash was determined in the fraction entrapped in the aluminosilicate matrix (0.329 µg g(-1)), followed by the oxidizable fraction (0.173 µg g(-1)). The lowest content of Tl was found in the water soluble fraction (0.001 µg g(-1)); however, this fraction is important due to the fact that Tl redistribution among all the fractions occurs through the aqueous phase.

Simultaneous application of chemical oxidation and extraction processes is effective at remediating soil Co-contaminated with petroleum and heavy metals.

PubMed

Yoo, Jong-Chan; Lee, Chadol; Lee, Jeung-Sun; Baek, Kitae

2017-01-15

Chemical extraction and oxidation processes to clean up heavy metals and hydrocarbon from soil have a higher remediation efficiency and take less time than other remediation processes. In batch extraction/oxidation process, 3% hydrogen peroxide (H 2 O 2 ) and 0.1 M ethylenediaminetetraacetic acid (EDTA) could remove approximately 70% of the petroleum and 60% of the Cu and Pb in the soil, respectively. In particular, petroleum was effectively oxidized by H 2 O 2 without addition of any catalysts through dissolution of Fe oxides in natural soils. Furthermore, heavy metals bound to Fe-Mn oxyhydroxides could be extracted by metal-EDTA as well as Fe-EDTA complexation due to the high affinity of EDTA for metals. However, the strong binding of Fe-EDTA inhibited the oxidation of petroleum in the extraction-oxidation sequential process because Fe was removed during the extraction process with EDTA. The oxidation-extraction sequential process did not significantly enhance the extraction of heavy metals from soil, because a small portion of heavy metals remained bound to organic matter. Overall, simultaneous application of oxidation and extraction processes resulted in highly efficient removal of both contaminants; this approach can be used to remove co-contaminants from soil in a short amount of time at a reasonable cost. Copyright © 2016 Elsevier Ltd. All rights reserved.

Scanning Mode Sensor for Detection of Flow Inhomogeneities

NASA Technical Reports Server (NTRS)

Adamovsky, Grigory (Inventor)

1998-01-01

A scanning mode sensor and method is provided for detection of flow inhomogeneities such as shock. The field of use of this invention is ground test control and engine control during supersonic flight. Prior art measuring techniques include interferometry. Schlieren, and shadowgraph techniques. These techniques. however, have problems with light dissipation. The present method and sensor utilizes a pencil beam of energy which is passed through a transparent aperture in a flow inlet in a time-sequential manner so as to alter the energy beam. The altered beam or its effects are processed and can be studied to reveal information about flow through the inlet which can in turn be used for engine control.

Scanning Mode Sensor for Detection of Flow Inhomogeneities

NASA Technical Reports Server (NTRS)

Adamovsky, Grigory (Inventor)

1996-01-01

A scanning mode sensor and method is provided for detection of flow inhomogeneities such as shock. The field of use of this invention is ground test control and engine control during supersonic flight. Prior art measuring techniques include interferometry, Schlieren, and shadowgraph techniques. These techniques, however, have problems with light dissipation. The present method and sensor utilizes a pencil beam of energy which is passed through a transparent aperture in a flow inlet in a time-sequential manner so as to alter the energy beam. The altered beam or its effects are processed and can be studied to reveal information about flow through the inlet which can in turn be used for engine control.

The use of sequential extraction to evaluate the remediation potential of heavy metals from contaminated harbour sediment

NASA Astrophysics Data System (ADS)

Nystrøm, G. M.; Ottosen, L. M.; Villumsen, A.

2003-05-01

In this work sequential extraction is performed with harbour sediment in order to evaluate the electrodialytic remediation potential for harbour sediments. Sequential extraction was performed on a sample of Norwegian harbour sediment; with the original sediment and after the sediment was treated with acid. The results from the sequential extraction show that 75% Zn and Pb and about 50% Cu are found in the most mobile phases in the original sediment and more than 90% Zn and Pb and 75% Cu are found in the most mobile phase in the sediment treated with acid. Electrodialytic remediation experiments were made. The method uses a low direct current as cleaning agent, removing the heavy metals towards the anode and cathode according to the charge of the heavy metals in the electric field. The electrodialytic experiments show that up to 50% Cu, 85% Zn and 60% Pb can be removed after 20 days. Thus, there is still a potential for a higher removal, with some changes in the experimental set-up and longer remediation time. The experiments show that thc use of sequential extraction can be used to predict the electrodialytic remediation potential for harbour sediments.

Evaluating specificity of sequential extraction for chemical forms of lead in artificially-contaminated and field-contaminated soils.

PubMed

Tai, Yiping; McBride, Murray B; Li, Zhian

2013-03-30

In the present study, we evaluated a commonly employed modified Bureau Communautaire de Référence (BCR test) 3-step sequential extraction procedure for its ability to distinguish forms of solid-phase Pb in soils with different sources and histories of contamination. When the modified BCR test was applied to mineral soils spiked with three forms of Pb (pyromorphite, hydrocerussite and nitrate salt), the added Pb was highly susceptible to dissolution in the operationally-defined "reducible" or "oxide" fraction regardless of form. When three different materials (mineral soil, organic soil and goethite) were spiked with soluble Pb nitrate, the BCR sequential extraction profiles revealed that soil organic matter was capable of retaining Pb in more stable and acid-resistant forms than silicate clay minerals or goethite. However, the BCR sequential extraction for field-collected soils with known and different sources of Pb contamination was not sufficiently discriminatory in the dissolution of soil Pb phases to allow soil Pb forms to be "fingerprinted" by this method. It is concluded that standard sequential extraction procedures are probably not very useful in predicting lability and bioavailability of Pb in contaminated soils. Copyright © 2013 Elsevier B.V. All rights reserved.

Unraveling the Fate and Transport of SrEDTA-2 and Sr+2 in Hanford Sediments

NASA Astrophysics Data System (ADS)

Pace, M. N.; Mayes, M. A.; Jardine, P. M.; Mehlhorn, T. L.; Liu, Q. G.; Yin, X. L.

2004-12-01

Accelerated migration of strontium-90 has been observed in the vadose zone beneath the Hanford tank farm. The goal of this paper is to provide an improved understanding of the hydrogeochemical processes that contribute to strontium transport in the far-field Hanford vadose zone. Laboratory scale batch, saturated packed column experiments, and an unsaturated transport experiment in an undisturbed core were conducted to quantify geochemical and hydrological processes controlling Sr+2 and SrEDTA-2 sorption to Hanford flood deposits. After experimentation, the undisturbed core was disassembled and samples were collected from different bedding units as a function of depth. Sequential extractions were then performed on the samples. It has been suggested that organic chelates such as EDTA may be responsible for the accelerated transport of strontium due to the formation of stable anionic complexes. Duplicate batch and column experiments performed with Sr+2 and SrEDTA-2 suggested that the SrEDTA-2 complex was not stable in the presence of soil and rapid dissociation allowed strontium to be transported as a divalent cation. Batch experiments indicated a decrease in sorption with increasing rock:water ratios, whereas saturated packed column experiments indicated equal retardation in columns of different lengths. This difference between the batch and column experiments is primarily due to the difference between equilibrium conditions where dissolution of cations may compete for sorption sites versus flowing conditions where any dissolved cations are flushed through the system minimizing competition for sorption sites. Unsaturated transport in the undisturbed core resulted in significant Sr+2 retardation despite the presence of physical nonequilibrium. Core disassembly and sequential extractions revealed the mass wetness distribution and reactive mineral phases associated with strontium in the core. Overall, results indicated that strontium will most likely be transported through the Hanford far-field vadose zone as a divalent cation.

Optimizing Standard Sequential Extraction Protocol With Lake And Ocean Sediments

EPA Science Inventory

The environmental mobility/availability behavior of radionuclides in soils and sediments depends on their speciation. Experiments have been carried out to develop a simple but robust radionuclide sequential extraction method for identification of radionuclide partitioning in sed...

Collaborative Filtering Based on Sequential Extraction of User-Item Clusters

NASA Astrophysics Data System (ADS)

Honda, Katsuhiro; Notsu, Akira; Ichihashi, Hidetomo

Collaborative filtering is a computational realization of “word-of-mouth” in network community, in which the items prefered by “neighbors” are recommended. This paper proposes a new item-selection model for extracting user-item clusters from rectangular relation matrices, in which mutual relations between users and items are denoted in an alternative process of “liking or not”. A technique for sequential co-cluster extraction from rectangular relational data is given by combining the structural balancing-based user-item clustering method with sequential fuzzy cluster extraction appraoch. Then, the tecunique is applied to the collaborative filtering problem, in which some items may be shared by several user clusters.

Sequential injection spectrophotometric determination of oxybenzone in lipsticks.

PubMed

Salvador, A; Chisvert, A; Camarasa, A; Pascual-Martí, M C; March, J G

2001-08-01

A sequential injection (SI) procedure for the spectrophotometric determination of oxybenzone in lipsticks is reported. The colorimetric reaction between nickel and oxybenzone was used. SI parameters such as sample solution volume, reagent solution volume, propulsion flow rate and reaction coil length were studied. The limit of detection was 3 microg ml(-1). The sensitivity was 0.0108+/-0.0002 ml microg(-1). The relative standard deviations of the results were between 6 and 12%. The real concentrations of samples and the values obtained by HPLC were comparable. Microwave sample pre-treatment allowed the extraction of oxybenzone with ethanol, thus avoiding the use of toxic organic solvents. Ethanol was also used as carrier in the SI system. Seventy-two injections per hour can be performed, which means a sample frequency of 24 h(-1) if three replicates are measured for each sample.

Radionuclide studies of chronic schistosomal uropathy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lamki, L.M.; Lamki, N.

1981-08-01

Fifty patients with chronic urinary tract schistosomiasis were studied with /sup 99m/Tc-DTPA. All had a flow study, sequential analog imaging, and digital imaging for 25-35 minutes (20-sec. frames). Time-activity curves (DTPA renograms) were extracted; 12 patients had /sup 131/I-Hippuran probe renograms as well. Renal changes included diminished perfusion and structural abnormalities ranging from minor calyceal dilatation to overt hydronephrosis. Ureteral changes included dilatation, tortuosity, and kinking. Marked distortion of the ureterovesical tunction was seen in some patients due to periureteral and perivesicular fibrosis, which is a major factor in upper urinary tract damage. Renograms showed varying obstruction and parenchymal damage.more » Nuclear medicine complements excretory urography and is sometimes preferable for visualization of the ureters. After the initial urogram, sequential DTPA scanning and renography are sufficient for follow-up.« less

Extraction of mercury from groundwater using immobilized algae.

PubMed

Barkley, N P

1991-10-01

Bio-Recovery Systems, Inc. conducted a project under the Emerging Technology portion of the United States Environmental Protection Agency's (EPAs) Superfund Innovative Technology Evaluation (SITE) Program to evaluate the ability of immobilized algae to adsorb mercury from contaminated groundwater in laboratory studies and pilot-scale field tests. Algal biomass was incorporated in a permeable polymeric matrix. The product, AlgaSORB, packed into adsorption columns, exhibited excellent flow characteristics, and functioned as a "biological" ion exchange resin. A sequence of eleven laboratory tests demonstrated the ability of this product to adsorb mercury from groundwater that contained high levels of total dissolved solids and hard water components. However, use of a single AlgaSORB preparation yielded nonrepeatable results with samples collected at different times of the year. The strategy of sequentially extracting the groundwater through two columns containing different preparations of AlgaSORB was developed and proved successful in laboratory and pilot-scale field tests. Field test results indicate that AlgaSORB could be economically competitive with ion exchange resins for removal of mercury, with the advantage that hardness and other dissolved solids do not appear to compete with heavy metals for binding capacity.

Separation of chemical groups from bio-oil aqueous phase via sequential organic solvent extraction

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ren, Shoujie; Ye, Philip; Borole, Abhijeet P

Bio-oil aqueous phase contains a considerable amount of furans, alcohols, ketones, aldehydes and phenolics besides the major components of organic acids and anhydrosugars. The complexity of bio-oil aqueous phase limits its efficient utilization. To improve the efficiency of bio-oil biorefinery, this study focused on the separation of chemical groups from bio-oil aqueous phase via sequential organic solvent extractions. Due to their high recoverability and low solubility in water, four solvents (hexane, petroleum ether, chloroform, and ethyl acetate) with different polarities were evaluated, and the optimum process conditions for chemical extraction were determined. Chloroform had high extraction efficiency for furans, phenolics,more » and ketones. In addition to these chemical groups, ethyl acetate had high extraction efficiency for organic acids. The sequential extraction by using chloroform followed by ethyl acetate rendered that 62.2 wt.% of original furans, ketones, alcohols, and phenolics were extracted to chloroform, over 62 wt.% acetic acid was extracted to ethyl acetate, resulting in a high concentration of levoglucosan (~53.0 wt.%) in the final aqueous phase. Chemicals separated via the sequential extraction could be used as feedstocks in biorefinery using processes such as catalytic upgrading of furans and phenolics to hydrocarbons, fermentation of levoglucosan to produce alcohols and diols, and hydrogen production from organic acids via microbial electrolysis.« less

Separation of chemical groups from bio-oil aqueous phase via sequential organic solvent extraction

DOE PAGES

Ren, Shoujie; Ye, Philip; Borole, Abhijeet P

2017-01-05

Bio-oil aqueous phase contains a considerable amount of furans, alcohols, ketones, aldehydes and phenolics besides the major components of organic acids and anhydrosugars. The complexity of bio-oil aqueous phase limits its efficient utilization. To improve the efficiency of bio-oil biorefinery, this study focused on the separation of chemical groups from bio-oil aqueous phase via sequential organic solvent extractions. Due to their high recoverability and low solubility in water, four solvents (hexane, petroleum ether, chloroform, and ethyl acetate) with different polarities were evaluated, and the optimum process conditions for chemical extraction were determined. Chloroform had high extraction efficiency for furans, phenolics,more » and ketones. In addition to these chemical groups, ethyl acetate had high extraction efficiency for organic acids. The sequential extraction by using chloroform followed by ethyl acetate rendered that 62.2 wt.% of original furans, ketones, alcohols, and phenolics were extracted to chloroform, over 62 wt.% acetic acid was extracted to ethyl acetate, resulting in a high concentration of levoglucosan (~53.0 wt.%) in the final aqueous phase. Chemicals separated via the sequential extraction could be used as feedstocks in biorefinery using processes such as catalytic upgrading of furans and phenolics to hydrocarbons, fermentation of levoglucosan to produce alcohols and diols, and hydrogen production from organic acids via microbial electrolysis.« less

Remediation of metal-contaminated marine sediments using active capping with limestone, steel slag, and activated carbon: a laboratory experiment.

PubMed

Park, Seong-Jik; Kang, Ku; Lee, Chang-Gu; Choi, Jae-Woo

2018-05-18

The objectives of this study are to assess the effectiveness of limestone (LS), steel slag (SS), and activated carbon (AC) as capping materials to sequester trace metals including As, Cd, Cr, Cu, Ni, Pb, and Zn in heavily contaminated marine sediments and to minimize the release of these metals into the water column. A flat flow tank was filled with 10 mm of capping material, contaminated sediments, and seawater, and the metal concentrations were monitored over 32 d. After completion of the flow tank experiments, the sediments below the capping material were sampled and were sequentially extracted. SS effectively reduced the As, Cr, Cu, Ni, Pb, and particularly Cd elution from the contaminated sediments to the overlying seawater. Adsorption and surface precipitation were the key mechanisms for interrupting the release of cationic trace metals by SS. LS was appropriate for interrupting the release of only Cu and Pb with high hydrolysis reaction constants. AC capping could interrupt the release of Cr, Cu, Ni, and particularly Zn from the sediments by binding with the metals via electrostatic interaction. The results obtained from the sequential extraction revealed that LS capping is appropriate for stabilizing Zn, whereas AC is appropriate for Cd and Pb. LS, SS, and AC can be applied effectively for remediation of sediments contaminated by trace metals because it interrupts their release and stabilizes the trace metals in the sediments.

Mining local climate data to assess spatiotemporal dengue fever epidemic patterns in French Guiana

PubMed Central

Flamand, Claude; Fabregue, Mickael; Bringay, Sandra; Ardillon, Vanessa; Quénel, Philippe; Desenclos, Jean-Claude; Teisseire, Maguelonne

2014-01-01

Objective To identify local meteorological drivers of dengue fever in French Guiana, we applied an original data mining method to the available epidemiological and climatic data. Through this work, we also assessed the contribution of the data mining method to the understanding of factors associated with the dissemination of infectious diseases and their spatiotemporal spread. Methods We applied contextual sequential pattern extraction techniques to epidemiological and meteorological data to identify the most significant climatic factors for dengue fever, and we investigated the relevance of the extracted patterns for the early warning of dengue outbreaks in French Guiana. Results The maximum temperature, minimum relative humidity, global brilliance, and cumulative rainfall were identified as determinants of dengue outbreaks, and the precise intervals of their values and variations were quantified according to the epidemiologic context. The strongest significant correlations were observed between dengue incidence and meteorological drivers after a 4–6-week lag. Discussion We demonstrated the use of contextual sequential patterns to better understand the determinants of the spatiotemporal spread of dengue fever in French Guiana. Future work should integrate additional variables and explore the notion of neighborhood for extracting sequential patterns. Conclusions Dengue fever remains a major public health issue in French Guiana. The development of new methods to identify such specific characteristics becomes crucial in order to better understand and control spatiotemporal transmission. PMID:24549761

Metal fractionation in olive oil and urban sewage sludges using the three-stage BCR sequential extraction method and microwave single extractions.

PubMed

Pérez Cid, B; Fernández Alborés, A; Fernández Gómez, E; Faliqé López, E

2001-08-01

The conventional three-stage BCR sequential extraction method was employed for the fractionation of heavy metals in sewage sludge samples from an urban wastewater treatment plant and from an olive oil factory. The results obtained for Cu, Cr, Ni, Pb and Zn in these samples were compared with those attained by a simplified extraction procedure based on microwave single extractions and using the same reagents as employed in each individual BCR fraction. The microwave operating conditions in the single extractions (heating time and power) were optimized for all the metals studied in order to achieve an extraction efficiency similar to that of the conventional BCR procedure. The measurement of metals in the extracts was carried out by flame atomic absorption spectrometry. The results obtained in the first and third fractions by the proposed procedure were, for all metals, in good agreement with those obtained using the BCR sequential method. Although in the reducible fraction the extraction efficiency of the accelerated procedure was inferior to that of the conventional method, the overall metals leached by both microwave single and sequential extractions were basically the same (recoveries between 90.09 and 103.7%), except for Zn in urban sewage sludges where an extraction efficiency of 87% was achieved. Chemometric analysis showed a good correlation between the results given by the two extraction methodologies compared. The application of the proposed approach to a certified reference material (CRM-601) also provided satisfactory results in the first and third fractions, as it was observed for the sludge samples analysed.

Combination of sequential chemical extraction and modelling of dam-break wave propagation to aid assessment of risk related to the possible collapse of a roasted sulphide tailings dam.

PubMed

Pérez-López, Rafael; Sáez, Reinaldo; Alvarez-Valero, Antonio M; Miguel Nieto, José; Pace, Gaetano

2009-10-15

The Sotiel-Coronada abandoned mining district (Iberian Pyrite Belt) produced complex massive sulphide ores which were processed by flotation to obtain Cu, Zn and Pb concentrates. The crude pyrite refuses were roasted for sulphuric acid production in a plant located close to the flotation site, and waste stored in a tailing dam. The present study was focused on the measurements of flow properties, chemical characterization and mineralogical determination of the roasted pyrite refuses with the aim of assessing the potential environmental impact in case of dam collapse. Chemical studies include the determination of the total contaminant content and information about their bio-availability or mobility using sequential extraction techniques. In the hypothetical case of the tailing dam breaking up and waste spilling (ca. 4.54Mt), a high density mud flow would flood the Odiel river valley and reach both Estuary of Huelva (Biosphere Reserve by UNESCO, 1983) and Atlantic Ocean in matter of a couple of days, as it was predicted by numerical simulations of dam-break waves propagation through the river valley based on quasi-2D Saint-Venant equations. The total amount of mobile pollutants that would be released into the surrounding environment is approximately of 7.1.10(4)t of S, 1.6.10(4)t of Fe, 1.4.10(4)t of As, 1.2.10(4)t of Zn, 1.0.10(4)t of Pb, 7.4.10(3)t of Mn, 2.2.10(3)t of Cu, 1.5.10(2)t of Co, 36t of Cd and 17t of Ni. Around 90-100% of S, Zn, Co and Ni, 60-70% of Mn and Cd, 30-40% of Fe and Cu, and 5% of As and Pb of the mobile fraction would be easily in the most labile fraction (water-soluble pollutants), and therefore, the most dangerous and bio-available for the environment. This gives an idea of the extreme potential risk of roasted pyrite ashes to the environment, until now little-described in the scientific literature.

Extensible packet processing architecture

DOEpatents

Robertson, Perry J.; Hamlet, Jason R.; Pierson, Lyndon G.; Olsberg, Ronald R.; Chun, Guy D.

2013-08-20

A technique for distributed packet processing includes sequentially passing packets associated with packet flows between a plurality of processing engines along a flow through data bus linking the plurality of processing engines in series. At least one packet within a given packet flow is marked by a given processing engine to signify by the given processing engine to the other processing engines that the given processing engine has claimed the given packet flow for processing. A processing function is applied to each of the packet flows within the processing engines and the processed packets are output on a time-shared, arbitered data bus coupled to the plurality of processing engines.

High-Resolution Photo-Mosaicing of the Rosebud Hydrothermal Vent Site and Surrounding Lava Flows, Galapagos Rift 86W: Techniques and Interpretations

NASA Astrophysics Data System (ADS)

Rzhanov, Y.; Mayer, L.; Fornari, D.; Shank, T.; Humphris, S.; Scheirer, D.; Kinsey, J.; Whitcomb, L.

2003-12-01

The Rosebud hydrothermal vent field was discovered in May 2002 in the Galapagos Rift near 86W during a series of Alvin dives and ABE autonomous vehicle surveys. Vertical-incidence digital imaging using a 3.1 Mpixel digital camera and strobe illumination from altitudes of 3-5m was carried out during the Alvin dives. A complete survey of the Rosebud vent site was carried out on Alvin Dive 3790. Submersible position was determined by post-cruise integration of 1.2 MHz bottom-lock Doppler sonar velocity data logged at 5Hz, integrated with heading and attitude data from a north-seeking fiber-optic gyroscope logged at 10Hz, and initialized with a surveyed-in long-baseline transponder navigation system providing geodetic position fixes at 15s intervals. The photo-mosaicing process consisted of three main stages: pre-processing, pair-wise image co-registration, and global alignment. Excellent image quality allowed us to avoid lens distortion correction, so images only underwent histogram equalization. Pair-wise co-registration of sequential frames was done partially automatically (where overlap exceeded 70 percent we employed a frequency-domain based technique), and partially manually (when overlap did not exceed 15 percent and manual feature extraction was the only way to find transformations relating the frames). Partial mosaics allowed us to determine which non-sequential frames had substantial overlap, and the corresponding transformations were found via feature extraction. Global alignment of the images consisted of construction of a sparse, nonlinear over-constrained system of equations reflecting positions of the frames in real-world coordinates. This system was solved using least squares, and the solution provided globally optimal positions of the frames in the overall mosaic. Over 700 images were mosaiced resulting in resolution of ~3 mm per pixel. The mosaiced area covers approximately 50 m x 60 m and clearly shows several biological zonations and distribution of lava flow morphologies, including what is interpreted as the contact between older lobate lava and the young sheet flow that hosts Rosebud vent communities. Recruitment of tubeworms, mussels, and clams is actively occurring at more than five locations oriented on a NE-SW trend where vent emissions occur through small cracks in the sheet flow. Large-scale views of seafloor hydrothermal vent sites, such as the one produced for Rosebud, are critical to properly understanding spatial relationships between hydrothermal biological communities, sites of focused and diffuse fluid flow, and the complex array of volcanic and tectonic features at mid-ocean ridge crests. These high-resolution perspectives are also critical to time-series studies where quantitative documentation of changes can be related to variations in hydrothermal, magmatic and tectonic processes.

Sequential Ideal-Observer Analysis of Visual Discriminations.

ERIC Educational Resources Information Center

Geisler, Wilson S.

1989-01-01

A new analysis, based on the concept of the ideal observer in signal detection theory, is described. It allows: tracing of the flow of discrimination information through the initial physiological stages of visual processing for arbitrary spatio-chromatic stimuli, and measurement of the information content of said visual stimuli. (TJH)

A novel processing platform for post tape out flows

NASA Astrophysics Data System (ADS)

Vu, Hien T.; Kim, Soohong; Word, James; Cai, Lynn Y.

2018-03-01

As the computational requirements for post tape out (PTO) flows increase at the 7nm and below technology nodes, there is a need to increase the scalability of the computational tools in order to reduce the turn-around time (TAT) of the flows. Utilization of design hierarchy has been one proven method to provide sufficient partitioning to enable PTO processing. However, as the data is processed through the PTO flow, its effective hierarchy is reduced. The reduction is necessary to achieve the desired accuracy. Also, the sequential nature of the PTO flow is inherently non-scalable. To address these limitations, we are proposing a quasi-hierarchical solution that combines multiple levels of parallelism to increase the scalability of the entire PTO flow. In this paper, we describe the system and present experimental results demonstrating the runtime reduction through scalable processing with thousands of computational cores.

Sequential extraction protocol for organic matter from soils and sediments using high resolution mass spectrometry

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tfaily, Malak M.; Chu, Rosalie K.; Toyoda, Jason

A vast number of organic compounds are present in soil organic matter (SOM) and play an important role in the terrestrial carbon cycle, facilitate interactions between organisms, and represent a sink for atmospheric CO2. The diversity of different SOM compounds and their molecular characteristics is a function of the organic source material and biogeochemical history. By understanding how SOM composition changes with sources and the processes by which it is biogeochemically altered in different terrestrial ecosystems, it may be possible to predict nutrient and carbon cycling, response to system perturbations, and impact of climate change will have on SOM composition.more » In this study, a sequential chemical extraction procedure was developed to reveal the diversity of organic matter (OM) in different ecosystems and was compared to the previously published protocol using parallel solvent extraction (PSE). We compared six extraction methods using three sample types, peat soil, spruce forest soil and river sediment, so as to select the best method for extracting a representative fraction of organic matter from soils and sediments from a wide range of ecosystems. We estimated the extraction yield of dissolved organic carbon (DOC) by total organic carbon analysis, and measured the composition of extracted OM using high resolution mass spectrometry. This study showed that OM composition depends primarily on soil and sediment characteristics. Two sequential extraction protocols, progressing from polar to non-polar solvents, were found to provide the highest number and diversity of organic compounds extracted from the soil and sediments. Water (H2O) is the first solvent used for both protocols followed by either co-extraction with methanol-chloroform (MeOH-CHCl3) mixture, or acetonitrile (ACN) and CHCl3 sequentially. The sequential extraction protocol developed in this study offers improved sensitivity, and requires less sample compared to the PSE workflow where a new sample is used for each solvent type. Furthermore, a comparison of SOM composition from the different sample types revealed that our sequential protocol allows for ecosystem comparisons based on the diversity of compounds present, which in turn could provide new insights about source and processing of organic compounds in different soil and sediment types.« less

Sequential extraction protocol for organic matter from soils and sediments using high resolution mass spectrometry.

PubMed

Tfaily, Malak M; Chu, Rosalie K; Toyoda, Jason; Tolić, Nikola; Robinson, Errol W; Paša-Tolić, Ljiljana; Hess, Nancy J

2017-06-15

A vast number of organic compounds are present in soil organic matter (SOM) and play an important role in the terrestrial carbon cycle, facilitate interactions between organisms, and represent a sink for atmospheric CO 2 . The diversity of different SOM compounds and their molecular characteristics is a function of the organic source material and biogeochemical history. By understanding how SOM composition changes with sources and the processes by which it is biogeochemically altered in different terrestrial ecosystems, it may be possible to predict nutrient and carbon cycling, response to system perturbations, and impact of climate change will have on SOM composition. In this study, a sequential chemical extraction procedure was developed to reveal the diversity of organic matter (OM) in different ecosystems and was compared to the previously published protocol using parallel solvent extraction (PSE). We compared six extraction methods using three sample types, peat soil, spruce forest soil and river sediment, so as to select the best method for extracting a representative fraction of organic matter from soils and sediments from a wide range of ecosystems. We estimated the extraction yield of dissolved organic carbon (DOC) by total organic carbon analysis, and measured the composition of extracted OM using high resolution mass spectrometry. This study showed that OM composition depends primarily on soil and sediment characteristics. Two sequential extraction protocols, progressing from polar to non-polar solvents, were found to provide the highest number and diversity of organic compounds extracted from the soil and sediments. Water (H 2 O) is the first solvent used for both protocols followed by either co-extraction with methanol-chloroform (MeOH-CHCl 3 ) mixture, or acetonitrile (ACN) and CHCl 3 sequentially. The sequential extraction protocol developed in this study offers improved sensitivity, and requires less sample compared to the PSE workflow where a new sample is used for each solvent type. Furthermore, a comparison of SOM composition from the different sample types revealed that our sequential protocol allows for ecosystem comparisons based on the diversity of compounds present, which in turn could provide new insights about source and processing of organic compounds in different soil and sediment types. Copyright © 2017 Elsevier B.V. All rights reserved.

Radionuclide studies of chronic schistosomal uropathy. [/sup 99m/Tc-DTPA; /sup 131/I-hippuran

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lamki, L.M.; Lamki, N.

1981-08-01

Fifty patients with chronic urinary tract schistosomiasis were studied with /sup 99m/Tc-DTPA. All had a flow study, sequential analog imaging, and digital imaging for 25 to 35 min (20-sec frames). Time-activity curves (DTPA renograms) were extracted; 12 patients had /sup 131/I-Hippuran probe renograms as well. Renal changes included diminished perfusion and structural abnormalities ranging from minor calyceal dilatation to overt hydronephrosis. Ureteral changes included dilatation, tortuosity, and kinking. Marked distortion of the ureterovesical junction was seen in some patients due to periureteral and perivesicular fibrosis, which is a major factor in upper urinary tract damage. Renograms showed varying obstruction andmore » parenchymal damage. Nuclear medicine complements excretory urography and is sometimes preferable for visualization of the ureters. After the initial urogram, sequential DTPA scanning and renography are sufficient for follow-up.« less

INVESTIGATION OF SEQUENTIAL AND ENZYMATIC EXTRACTION OF ARSENIC FROM DRINKING WATER DISTRIBUTION SOLIDS WITH ICP-MS

EPA Science Inventory

A sequential extraction approach was utilized to estimate the distribution of arsenite [As(III)] and arsenate [As(V)] on iron oxide/hydroxide solids obtained from drinking water distribution systems. The arsenic (As) associated with these solids can be segregated into three oper...

ASSESSMENT OF A SEQUENTIAL EXTRACTION PROCEDURE FOR PERTURBED LEAD-CONTAMINATED SAMPLES WITH AND WITHOUT PHOSPHOROUS AMENDMENTS

EPA Science Inventory

Sequential extraction procedures are used to determine the solid-phase association in which elements of interest exist in soil and sediment matrices. Foundational work by Tessier et al. (1) has found widespread acceptance and has worked tolerably as an operational definition for...

Surface characterization of cottonseed meal products by SEM, SEM-EDS, XRD and XPS analysis

USDA-ARS?s Scientific Manuscript database

The utilization of cottonseed meal as a valuable industrial feedstock needs to be exploited. We have recently produced water-washed cottonseed meal, total cottonseed protein, sequentially extracted water- and alkali-soluble proteins, and two residues after the total and sequential protein extraction...

Exploiting an automated microfluidic hydrodynamic sequential injection system for determination of phosphate.

PubMed

Khongpet, Wanpen; Pencharee, Somkid; Puangpila, Chanida; Kradtap Hartwell, Supaporn; Lapanantnoppakhun, Somchai; Jakmunee, Jaroon

2018-01-15

A microfluidic hydrodynamic sequential injection (μHSI) spectrophotometric system was designed and fabricated. The system was built by laser engraving a manifold pattern on an acrylic block and sealing with another flat acrylic plate to form a microfluidic channel platform. The platform was incorporated with small solenoid valves to obtain a portable setup for programmable control of the liquid flow into the channel according to the HSI principle. The system was demonstrated for the determination of phosphate using a molybdenum blue method. An ascorbic acid, standard or sample, and acidic molybdate solutions were sequentially aspirated to fill the channel forming a stack zone before flowing to the detector. Under the optimum condition, a linear calibration graph in the range of 0.1-6mg P L -1 was obtained. The detection limit was 0.1mgL -1 . The system is compact (5.0mm thick, 80mm wide × 140mm long), durable, portable, cost-effective, and consumes little amount of chemicals (83μL each of molybdate and ascorbic acid, 133μL of the sample solution and 1.7mL of water carrier/run). It was applied for the determination of phosphate content in extracted soil samples. The percent recoveries of the analysis were obtained in the range of 91.2-107.3. The results obtained agreed well with those of the batch spectrophotometric method. Copyright © 2017 Elsevier B.V. All rights reserved.

The utilization of modified BCR three-step sequential extraction procedure for the fractionation of Cd, Cr, Cu, Ni, Pb and Zn in soil reference materials of different origins.

PubMed

Zemberyová, Mária; Barteková, Jana; Hagarová, Ingrid

2006-12-15

A modified three-step sequential extraction procedure for the fractionation of heavy metals, proposed by the Commission of the European Communities Bureau of Reference (BCR) has been applied to the Slovak reference materials of soils (soil orthic luvisols, soil rendzina and soil eutric cambisol), which represent pedologically different types of soils in Slovakia. Analyses were carried out by flame or electrothermal atomic absorption spectrometry (FAAS or ETAAS). The fractions extracted were: exchangeable (extraction step 1), reducible-iron/manganese oxides (extraction step 2), oxidizable-organic matter and sulfides (extraction step 3). The sum of the element contents in the three fractions plus aqua-regia extractable content of the residue was compared to the aqua-regia extractable content of the elements in the origin soils. The accuracy obtained by comparing the determined contents of the elements with certified values, using BCR CRM 701, certified for the extractable contents (mass fractions) of Cd, Cr, Cu, Ni, Pb and Zn in sediment following a modified BCR-three step sequential extraction procedure, was found to be satisfactory.

Sequential extractions of selenium soils from Stewart Lake: total selenium and speciation measurements with ICP-MS detection.

PubMed

Ponce de León, Claudia A; DeNicola, Katie; Montes Bayón, Maria; Caruso, Joseph A

2003-06-01

Different techniques have been employed in order to evaluate the most efficient procedure for the extraction of selenium from soil as required for speciation. Selenium contaminated sediments from Stewart Lake Wetland, California were used. A strong acid mineralization of the samples gives quantitative total selenium, which is then used to estimate recoveries for the milder extraction methods. The different extraction methodologies involve the sequential use of water, buffer (phosphate, pH 7) and either acid solution (e.g. HNO3 or HCl) or basic solutions (e.g. ammonium acetate, NaOH or TMAH). Pyrophosphate extraction was also evaluated and showed that selenium was not associated with humic acids. The extractants were subsequently analyzed by size exclusion chromatography (SEC) with UV (254 and 400 nm) and on-line ICP-MS detection; anion exchange chromatography, and ion-pair reversed phase chromatography with ICP-MS detection. For sequential extractions the extraction efficiencies showed that the basic extractions were more efficient than the acidic. The difference between the acidic and the basic extraction efficiency is carried to the sulfite extraction, suggesting that whatever is not extracted by the acid is subsequently extracted by the sulfite. The species identified with the different chromatographies were selenate, selenite, elemental selenium and some organic selenium.

Utilization of optimized BCR three-step sequential and dilute HCl single extraction procedures for soil-plant metal transfer predictions in contaminated lands.

PubMed

Kubová, Jana; Matús, Peter; Bujdos, Marek; Hagarová, Ingrid; Medved', Ján

2008-05-30

The prediction of soil metal phytoavailability using the chemical extractions is a conventional approach routinely used in soil testing. The adequacy of such soil tests for this purpose is commonly assessed through a comparison of extraction results with metal contents in relevant plants. In this work, the fractions of selected risk metals (Al, As, Cd, Cu, Fe, Mn, Ni, Pb, Zn) that can be taken up by various plants were obtained by optimized BCR (Community Bureau of Reference) three-step sequential extraction procedure (SEP) and by single 0.5 mol L(-1) HCl extraction. These procedures were validated using five soil and sediment reference materials (SRM 2710, SRM 2711, CRM 483, CRM 701, SRM RTH 912) and applied to significantly different acidified soils for the fractionation of studied metals. The new indicative values of Al, Cd, Cu, Fe, Mn, P, Pb and Zn fractional concentrations for these reference materials were obtained by the dilute HCl single extraction. The influence of various soil genesis, content of essential elements (Ca, Mg, K, P) and different anthropogenic sources of acidification on extraction yields of individual risk metal fractions was investigated. The concentrations of studied elements were determined by atomic spectrometry methods (flame, graphite furnace and hydride generation atomic absorption spectrometry and inductively coupled plasma optical emission spectrometry). It can be concluded that the data of extraction yields from first BCR SEP acid extractable step and soil-plant transfer coefficients can be applied to the prediction of qualitative mobility of selected risk metals in different soil systems.

Sulfur K-edge XANES and acid volatile sulfide analyses of changes in chemical speciation of S and Fe during sequential extraction of trace metals in anoxic sludge from biogas reactors.

PubMed

Shakeri Yekta, Sepehr; Gustavsson, Jenny; Svensson, Bo H; Skyllberg, Ulf

2012-01-30

The effect of sequential extraction of trace metals on sulfur (S) speciation in anoxic sludge samples from two lab-scale biogas reactors augmented with Fe was investigated. Analyses of sulfur K-edge X-ray absorption near edge structure (S XANES) spectroscopy and acid volatile sulfide (AVS) were conducted on the residues from each step of the sequential extraction. The S speciation in sludge samples after AVS analysis was also determined by S XANES. Sulfur was mainly present as FeS (≈ 60% of total S) and reduced organic S (≈ 30% of total S), such as organic sulfide and thiol groups, in the anoxic solid phase. Sulfur XANES and AVS analyses showed that during first step of the extraction procedure (the removal of exchangeable cations), a part of the FeS fraction corresponding to 20% of total S was transformed to zero-valent S, whereas Fe was not released into the solution during this transformation. After the last extraction step (organic/sulfide fraction) a secondary Fe phase was formed. The change in chemical speciation of S and Fe occurring during sequential extraction procedure suggests indirect effects on trace metals associated to the FeS fraction that may lead to incorrect results. Furthermore, by S XANES it was verified that the AVS analysis effectively removed the FeS fraction. The present results identified critical limitations for the application of sequential extraction for trace metal speciation analysis outside the framework for which the methods were developed. Copyright © 2011 Elsevier B.V. All rights reserved.

Partial least squares model and design of experiments toward the analysis of the metabolome of Jatropha gossypifolia leaves: Extraction and chromatographic fingerprint optimization.

PubMed

Pilon, Alan Cesar; Carnevale Neto, Fausto; Freire, Rafael Teixeira; Cardoso, Patrícia; Carneiro, Renato Lajarim; Da Silva Bolzani, Vanderlan; Castro-Gamboa, Ian

2016-03-01

A major challenge in metabolomic studies is how to extract and analyze an entire metabolome. So far, no single method was able to clearly complete this task in an efficient and reproducible way. In this work we proposed a sequential strategy for the extraction and chromatographic separation of metabolites from leaves Jatropha gossypifolia using a design of experiments and partial least square model. The effect of 14 different solvents on extraction process was evaluated and an optimized separation condition on liquid chromatography was estimated considering mobile phase composition and analysis time. The initial conditions of extraction using methanol and separation in 30 min between 5 and 100% water/methanol (1:1 v/v) with 0.1% of acetic acid, 20 μL sample volume, 3.0 mL min(-1) flow rate and 25°C column temperature led to 107 chromatographic peaks. After the optimization strategy using i-propanol/chloroform (1:1 v/v) for extraction, linear gradient elution of 60 min between 5 and 100% water/(acetonitrile/methanol 68:32 v/v with 0.1% of acetic acid), 30 μL sample volume, 2.0 mL min(-1) flow rate, and 30°C column temperature, we detected 140 chromatographic peaks, 30.84% more peaks compared to initial method. This is a reliable strategy using a limited number of experiments for metabolomics protocols. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Dynamics assembly of magnetic microparticles suspended in moving droplets under the influence of magnetic fields

NASA Astrophysics Data System (ADS)

Strey, Helmut; Brouzes, Eric; Kruse, Travis

2013-03-01

Droplet microfluidics has experienced tremendous growth, particularly since it is well suited for single-cell manipulation and analysis. As mature methods for high throughput droplet manipulation have been developed a technological bottleneck of current droplet microfluidics is that because droplets are separated, sequential chemical reactions are more difficult to achieve. For example, it is very difficult to concentrate target molecules, especially since every reaction step adds volume to the droplets. Our solution to this problem is to employ functionalized magnetic beads inside droplets. The basic idea is that an external magnetic field could be used to concentrate the magnetic beads in one part of the droplet and those could then be extracted by splitting the droplet. Here we present an experimental study of the self-assembly of superparamagnetic microparticles that are suspended in moving droplets and experience a combination of forces due to the internal fluid flow fields and external magnetic fields. We observed that this interplay of flow fields coupled to the formation of particle assemblies leads to the formations of stable patterns depending on the flow speed and magnetic field strength. An understanding of this dynamic assembly is critical in employing external forces for applications in separation and sorting. Funding through NYSTAR, Center for Advanced Technology and a grant from NIH-NHGRI (1 R21 HG006206-01).

Earth Science and Applications attached payloads on Space Station

NASA Technical Reports Server (NTRS)

Wicks, Thomas G.; Arnold, Ralph R.

1990-01-01

This paper describes the Office of Space Science and Applications' process for Attached Payloads on Space Station Freedom from development through on-orbit operations. Its primary objectives are to detail the sequential steps of the attached payload methodology by tracing in particular the selected Earth Science and Applications' payloads through this flow and relate the integral role of Marshall Space Flight Center's Science Utilization Management function of integration and operations.

Unsteady, one-dimensional gas dynamics computations using a TVD type sequential solver

NASA Technical Reports Server (NTRS)

Thakur, Siddharth; Shyy, Wei

1992-01-01

The efficacy of high resolution convection schemes to resolve sharp gradient in unsteady, 1D flows is examined using the TVD concept based on a sequential solution algorithm. Two unsteady flow problems are considered which include the problem involving the interaction of the various waves in a shock tube with closed reflecting ends and the problem involving the unsteady gas dynamics in a tube with closed ends subject to an initial pressure perturbation. It is concluded that high accuracy convection schemes in a sequential solution framework are capable of resolving discontinuities in unsteady flows involving complex gas dynamics. However, a sufficient amount of dissipation is required to suppress oscillations near discontinuities in the sequential approach, which leads to smearing of the solution profiles.

Determination of trace zinc in seawater by coupling solid phase extraction and fluorescence detection in the Lab-On-Valve format.

PubMed

Grand, Maxime M; Chocholouš, Petr; Růžička, Jarda; Solich, Petr; Measures, Christopher I

2016-06-07

By virtue of their compactness, long-term stability, minimal reagent consumption and robustness, miniaturized sequential injection instruments are well suited for automation of assays onboard research ships. However, in order to reach the sensitivity and limit of detection required for open-ocean determinations of trace elements, it is necessary to preconcentrate the analyte prior its derivatization and subsequent detection by fluorescence. In this work, a novel method for the determination of dissolved zinc (Zn) at subnanomolar levels in seawater is described. The proposed method combines, for the first time, automated matrix removal, extraction of the target element, and fluorescence detection within a miniaturized flow manifold, based on the Lab-On-Valve (LOV) concept. The key feature of the microfluidic manipulation of the sample is flow programming, designed to pass sample through a mini-column where the target analyte and other complexable cations are retained, while the seawater matrix is washed out. Next, zinc is eluted and merged with a Zn selective fluorescent probe (FluoZin-3) at the confluence point of the LOV central channel using two high-precision stepper motor driven pumps that are operated in concert. Finally, the thus formed Zn complex is transported to the LOV flow cell for selective fluorescence measurement. This work describes the characterization and optimization of the method including Solid Phase Extraction using the Toyopearl AF-Chelate-650M resin, and detailed assay protocol controlled by a commercially available software and instrument. The proposed method features a LOD of 0.02 nM, high precision (<3% at 0.1 and 2 nM Zn levels), an assay cycle of 13 min and a reagent consumption of 150 μL FluoZin-3 per sample, which makes the method highly suitable for oceanographic shipboard analysis. The accuracy of the method has been validated through the analysis of seawater reference standards and comparison with ICP-MS determinations on seawater samples collected in the upper 1300 m of the subtropical south Indian Ocean. This work confirms that integration of sample pretreatment with optical detection in the LOV format offers a widely applicable approach to trace analysis of seawater. Copyright © 2016. Published by Elsevier B.V.

Phosphorus Speciation of Sequential Extracts of Organic Amendments using NMR Spectroscopy

NASA Astrophysics Data System (ADS)

Akinremi, O.

2009-04-01

O.O. 1Akinremi Babasola Ajiboye and Donald N. Flaten 1Department of Soil Science, University of Manitoba, Winnipeg, R3T 2NT, Canada We carried out this study in order to determine the forms of phosphorus in various organic amendments using state-of-the art spectroscopic technique. Anaerobically digested biosolids (BIO), hog (HOG), dairy (DAIRY), beef (BEEF) and poultry (POULTRY) manures were subjected to sequential extraction. The extracts were analyzed by solution 31P nuclear magnetic resonance (NMR) spectroscopy. Most of the total P analysed by inductively coupled plasma-optical emission spectroscopy (ICP-OES) in the sequential extracts of organic amendments were orthophosphate, except POULTRY, which was dominated by organic P. The labile P fraction in all the organic amendments, excluding POULTRY, was mainly orthophosphate P from readily soluble calcium and some aluminum phosphates. In the poultry litter, however, Ca phytate was the main P species controlling P solubility. Such knowledge of the differences in the chemical forms of phosphorus in organic amendments are essential for proper management of these amendments for agro-environmental purposes Key words: organic amendments, solution NMR, sequential fractionation, labile phosphorus

Mining local climate data to assess spatiotemporal dengue fever epidemic patterns in French Guiana.

PubMed

Flamand, Claude; Fabregue, Mickael; Bringay, Sandra; Ardillon, Vanessa; Quénel, Philippe; Desenclos, Jean-Claude; Teisseire, Maguelonne

2014-10-01

To identify local meteorological drivers of dengue fever in French Guiana, we applied an original data mining method to the available epidemiological and climatic data. Through this work, we also assessed the contribution of the data mining method to the understanding of factors associated with the dissemination of infectious diseases and their spatiotemporal spread. We applied contextual sequential pattern extraction techniques to epidemiological and meteorological data to identify the most significant climatic factors for dengue fever, and we investigated the relevance of the extracted patterns for the early warning of dengue outbreaks in French Guiana. The maximum temperature, minimum relative humidity, global brilliance, and cumulative rainfall were identified as determinants of dengue outbreaks, and the precise intervals of their values and variations were quantified according to the epidemiologic context. The strongest significant correlations were observed between dengue incidence and meteorological drivers after a 4-6-week lag. We demonstrated the use of contextual sequential patterns to better understand the determinants of the spatiotemporal spread of dengue fever in French Guiana. Future work should integrate additional variables and explore the notion of neighborhood for extracting sequential patterns. Dengue fever remains a major public health issue in French Guiana. The development of new methods to identify such specific characteristics becomes crucial in order to better understand and control spatiotemporal transmission. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

Fractionation of trace elements in agricultural soils using ultrasound assisted sequential extraction prior to inductively coupled plasma mass spectrometric determination.

PubMed

Matong, Joseph M; Nyaba, Luthando; Nomngongo, Philiswa N

2016-07-01

The main objectives of this study were to determine the concentration of fourteen trace elements and to investigate their distribution as well as a contamination levels in selected agricultural soils. An ultrasonic assisted sequential extraction procedure derived from three-step BCR method was used for fractionation of trace elements. The total concentration of trace elements in soil samples was obtained by total digestion method in soil samples with aqua regia. The results of the extractable fractions revealed that most of the target trace elements can be transferred to the human being through the food chain, thus leading to serious human health. Enrichment factor (EF), geo-accumulation index (Igeo), contamination factor (CF), risk assessment code (RAC) and individual contamination factors (ICF) were used to assess the environmental impacts of trace metals in soil samples. The EF revealed that Cd was enriched by 3.1-7.2 (except in Soil 1). The Igeo results showed that the soils in the study area was moderately contaminated with Fe, and heavily to extremely polluted with Cd. The soil samples from the unplanted field was found to have highest contamination factor for Cd and lowest for Pb. Soil 3 showed a high risk for Tl and Cd with RAC values of greater than or equal to 50%. In addition, Fe, Ni, Cu, V, As, Mo (except Soil 2), Sb and Pb posed low environmental risk. The modified BCR sequential extraction method provided more information about mobility and environmental implication of studied trace elements in the study area. Copyright © 2016 Elsevier Ltd. All rights reserved.

Simulations of 6-DOF Motion with a Cartesian Method

NASA Technical Reports Server (NTRS)

Murman, Scott M.; Aftosmis, Michael J.; Berger, Marsha J.; Kwak, Dochan (Technical Monitor)

2003-01-01

Coupled 6-DOF/CFD trajectory predictions using an automated Cartesian method are demonstrated by simulating a GBU-32/JDAM store separating from an F-18C aircraft. Numerical simulations are performed at two Mach numbers near the sonic speed, and compared with flight-test telemetry and photographic-derived data. Simulation results obtained with a sequential-static series of flow solutions are contrasted with results using a time-dependent flow solver. Both numerical methods show good agreement with the flight-test data through the first half of the simulations. The sequential-static and time-dependent methods diverge over the last half of the trajectory prediction. after the store produces peak angular rates. A cost comparison for the Cartesian method is included, in terms of absolute cost and relative to computing uncoupled 6-DOF trajectories. A detailed description of the 6-DOF method, as well as a verification of its accuracy, is provided in an appendix.

Sensor Analytics: Radioactive gas Concentration Estimation and Error Propagation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Anderson, Dale N.; Fagan, Deborah K.; Suarez, Reynold

2007-04-15

This paper develops the mathematical statistics of a radioactive gas quantity measurement and associated error propagation. The probabilistic development is a different approach to deriving attenuation equations and offers easy extensions to more complex gas analysis components through simulation. The mathematical development assumes a sequential process of three components; I) the collection of an environmental sample, II) component gas extraction from the sample through the application of gas separation chemistry, and III) the estimation of radioactivity of component gases.

Near real-time adverse drug reaction surveillance within population-based health networks: methodology considerations for data accrual.

PubMed

Avery, Taliser R; Kulldorff, Martin; Vilk, Yury; Li, Lingling; Cheetham, T Craig; Dublin, Sascha; Davis, Robert L; Liu, Liyan; Herrinton, Lisa; Brown, Jeffrey S

2013-05-01

This study describes practical considerations for implementation of near real-time medical product safety surveillance in a distributed health data network. We conducted pilot active safety surveillance comparing generic divalproex sodium to historical branded product at four health plans from April to October 2009. Outcomes reported are all-cause emergency room visits and fractures. One retrospective data extract was completed (January 2002-June 2008), followed by seven prospective monthly extracts (January 2008-November 2009). To evaluate delays in claims processing, we used three analytic approaches: near real-time sequential analysis, sequential analysis with 1.5 month delay, and nonsequential (using final retrospective data). Sequential analyses used the maximized sequential probability ratio test. Procedural and logistical barriers to active surveillance were documented. We identified 6586 new users of generic divalproex sodium and 43,960 new users of the branded product. Quality control methods identified 16 extract errors, which were corrected. Near real-time extracts captured 87.5% of emergency room visits and 50.0% of fractures, which improved to 98.3% and 68.7% respectively with 1.5 month delay. We did not identify signals for either outcome regardless of extract timeframe, and slight differences in the test statistic and relative risk estimates were found. Near real-time sequential safety surveillance is feasible, but several barriers warrant attention. Data quality review of each data extract was necessary. Although signal detection was not affected by delay in analysis, when using a historical control group differential accrual between exposure and outcomes may theoretically bias near real-time risk estimates towards the null, causing failure to detect a signal. Copyright © 2013 John Wiley & Sons, Ltd.

Chromium fate in constructed wetlands treating tannery wastewaters.

PubMed

Dotro, Gabriela; Palazolo, Paul; Larsen, Daniel

2009-06-01

Nine experimental wetlands were built to determine chromium partitioning inside systems treating tannery wastewaters. Results showed 5-day biochemical oxygen demand and chromium removals of 95 to 99% and 90 to 99%, respectively. The majority of chromium was found in association with media (96 to 98%), followed by effluents (2.9 to 3.9%), and the least was found in plant parts (0.1%). Chemical speciation modeling of solutions and scanning electron microscope analysis suggest two potential chromium removal mechanisms--sorption/coprecipitation with iron hydroxides or oxyhydroxides and biomass sorption. The release of the majority of chromium in the iron- and organic-bound phases during sequential extractions supports the proposed dominant removal mechanisms. The use of a mixture of peat and gravel resulted in lower removal efficiencies and stronger partitioning in organic phases during sequential extractions. Chromium was efficiently removed by wetlands, retained through chemical and biological processes. Future research will focus on further exploring removal mechanisms and proposing management strategies for the chromium-containing wetland media.

Learning Orthographic Structure With Sequential Generative Neural Networks.

PubMed

Testolin, Alberto; Stoianov, Ivilin; Sperduti, Alessandro; Zorzi, Marco

2016-04-01

Learning the structure of event sequences is a ubiquitous problem in cognition and particularly in language. One possible solution is to learn a probabilistic generative model of sequences that allows making predictions about upcoming events. Though appealing from a neurobiological standpoint, this approach is typically not pursued in connectionist modeling. Here, we investigated a sequential version of the restricted Boltzmann machine (RBM), a stochastic recurrent neural network that extracts high-order structure from sensory data through unsupervised generative learning and can encode contextual information in the form of internal, distributed representations. We assessed whether this type of network can extract the orthographic structure of English monosyllables by learning a generative model of the letter sequences forming a word training corpus. We show that the network learned an accurate probabilistic model of English graphotactics, which can be used to make predictions about the letter following a given context as well as to autonomously generate high-quality pseudowords. The model was compared to an extended version of simple recurrent networks, augmented with a stochastic process that allows autonomous generation of sequences, and to non-connectionist probabilistic models (n-grams and hidden Markov models). We conclude that sequential RBMs and stochastic simple recurrent networks are promising candidates for modeling cognition in the temporal domain. Copyright © 2015 Cognitive Science Society, Inc.

Modified sequential extraction for biochar and petroleum coke: Metal release potential and its environmental implications.

PubMed

von Gunten, Konstantin; Alam, Md Samrat; Hubmann, Magdalena; Ok, Yong Sik; Konhauser, Kurt O; Alessi, Daniel S

2017-07-01

A modified Community Bureau of Reference (CBR) sequential extraction method was tested to assess the composition of untreated pyrogenic carbon (biochar) and oil sands petroleum coke. Wood biochar samples were found to contain lower concentrations of metals, but had higher fractions of easily mobilized alkaline earth and transition metals. Sewage sludge biochar was determined to be less recalcitrant and had higher total metal concentrations, with most of the metals found in the more resilient extraction fractions (oxidizable, residual). Petroleum coke was the most stable material, with a similar metal distribution pattern as the sewage sludge biochar. The applied sequential extraction method represents a suitable technique to recover metals from these materials, and is a valuable tool in understanding the metal retaining and leaching capability of various biochar types and carbonaceous petroleum coke samples. Copyright © 2017 Elsevier Ltd. All rights reserved.

Sequential segmental terminal lenticular side-cut dissection for safe and effective small-incision lenticule extraction in thin lenticules.

PubMed

Jacob, Soosan; Agarwal, Amar; Mazzotta, Cosimo; Agarwal, Athiya; Raj, John Michael

2017-04-01

Small-incision lenticule extraction may be associated with complications such as partial lenticular dissection, torn lenticule, lenticular adherence to cap, torn cap, and sub-cap epithelial ingrowth, some of which are more likely to occur during low-myopia corrections. We describe sequential segmental terminal lenticular side-cut dissection to facilitate minimally traumatic and smooth lenticular extraction. Anterior lamellar dissection is followed by central posterior lamellar dissection, leaving a thin peripheral rim and avoiding the lenticular side cut. This is followed by sequential segmental dissection of the lenticular side cut in a manner that fixates the lenticule and provides sufficient resistance for smooth and complete dissection of the posterior lamellar cut without undesired movements of the lenticule. The technique is advantageous in thin lenticules, where the risk for complications is high, but can also be used in thick lenticular dissection using wider sweeps to separate the lenticular side cut sequentially. Copyright © 2017 ASCRS and ESCRS. Published by Elsevier Inc. All rights reserved.

Difference in vascular patterns between transosseous-equivalent and transosseous rotator cuff repair.

PubMed

Urita, Atsushi; Funakoshi, Tadanao; Horie, Tatsunori; Nishida, Mutsumi; Iwasaki, Norimasa

2017-01-01

Vascularity is the important factor of biologic healing of the repaired tissue. The purpose of this study was to clarify sequential vascular patterns of repaired rotator cuff by suture techniques. We randomized 21 shoulders in 20 patients undergoing arthroscopic rotator cuff repair into 2 groups: transosseous-equivalent repair (TOE group, n = 10) and transosseous repair (TO group, n = 11). Blood flow in 4 regions inside the cuff (lateral articular, lateral bursal, medial articular, and medial bursal), in the knotless suture anchor in the TOE group, and in the bone tunnel in the TO group was measured using contrast-enhanced ultrasound at 1 month, 2 months, 3 months, and 6 months postoperatively. The sequential vascular pattern inside the repaired rotator cuff was different between groups. The blood flow in the lateral articular area at 1 month, 2 months, and 3 months (P = .002, .005, and .025) and that in the lateral bursal area at 2 months (P = .031) in the TO group were significantly greater than those in the TOE group postoperatively. Blood flow was significantly greater for the bone tunnels in the TO group than for the knotless suture anchor in the TOE group at 1 month and 2 months postoperatively (P = .041 and .009). This study clarified that the sequential vascular pattern inside the repaired rotator cuff depends on the suture technique used. Bone tunnels through the footprint may contribute to biologic healing by increasing blood flow in the repaired rotator cuff. Copyright © 2017 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Elsevier Inc. All rights reserved.

Multiparticle imaging technique for two-phase fluid flows using pulsed laser speckle velocimetry. Final report, September 1988--November 1992

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hassan, T.A.

1992-12-01

The practical use of Pulsed Laser Velocimetry (PLV) requires the use of fast, reliable computer-based methods for tracking numerous particles suspended in a fluid flow. Two methods for performing tracking are presented. One method tracks a particle through multiple sequential images (minimum of four required) by prediction and verification of particle displacement and direction. The other method, requiring only two sequential images uses a dynamic, binary, spatial, cross-correlation technique. The algorithms are tested on computer-generated synthetic data and experimental data which was obtained with traditional PLV methods. This allowed error analysis and testing of the algorithms on real engineering flows.more » A novel method is proposed which eliminates tedious, undersirable, manual, operator assistance in removing erroneous vectors. This method uses an iterative process involving an interpolated field produced from the most reliable vectors. Methods are developed to allow fast analysis and presentation of sets of PLV image data. Experimental investigation of a two-phase, horizontal, stratified, flow regime was performed to determine the interface drag force, and correspondingly, the drag coefficient. A horizontal, stratified flow test facility using water and air was constructed to allow interface shear measurements with PLV techniques. The experimentally obtained local drag measurements were compared with theoretical results given by conventional interfacial drag theory. Close agreement was shown when local conditions near the interface were similar to space-averaged conditions. However, theory based on macroscopic, space-averaged flow behavior was shown to give incorrect results if the local gas velocity near the interface as unstable, transient, and dissimilar from the average gas velocity through the test facility.« less

Multiparticle imaging technique for two-phase fluid flows using pulsed laser speckle velocimetry

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hassan, T.A.

1992-12-01

The practical use of Pulsed Laser Velocimetry (PLV) requires the use of fast, reliable computer-based methods for tracking numerous particles suspended in a fluid flow. Two methods for performing tracking are presented. One method tracks a particle through multiple sequential images (minimum of four required) by prediction and verification of particle displacement and direction. The other method, requiring only two sequential images uses a dynamic, binary, spatial, cross-correlation technique. The algorithms are tested on computer-generated synthetic data and experimental data which was obtained with traditional PLV methods. This allowed error analysis and testing of the algorithms on real engineering flows.more » A novel method is proposed which eliminates tedious, undersirable, manual, operator assistance in removing erroneous vectors. This method uses an iterative process involving an interpolated field produced from the most reliable vectors. Methods are developed to allow fast analysis and presentation of sets of PLV image data. Experimental investigation of a two-phase, horizontal, stratified, flow regime was performed to determine the interface drag force, and correspondingly, the drag coefficient. A horizontal, stratified flow test facility using water and air was constructed to allow interface shear measurements with PLV techniques. The experimentally obtained local drag measurements were compared with theoretical results given by conventional interfacial drag theory. Close agreement was shown when local conditions near the interface were similar to space-averaged conditions. However, theory based on macroscopic, space-averaged flow behavior was shown to give incorrect results if the local gas velocity near the interface as unstable, transient, and dissimilar from the average gas velocity through the test facility.« less

Improving enzymatic hydrolysis efficiency of wheat straw through sequential autohydrolysis and alkaline post-extraction.

PubMed

Wu, Xinxing; Huang, Chen; Zhai, Shengcheng; Liang, Chen; Huang, Caoxing; Lai, Chenhuan; Yong, Qiang

2018-03-01

In this work, a two-step pretreatment process of wheat straw was established by combining autohydrolysis pretreatment and alkaline post-extraction. The results showed that employing alkaline post-extraction to autohydrolyzed wheat straw could significantly improve its enzymatic hydrolysis efficiency from 36.0% to 83.7%. Alkaline post-extraction lead to the changes of the structure characteristics of autohydrolyzed wheat straw. Associations between enzymatic hydrolysis efficiency and structure characteristics were also studied. The results showed that the factors of structure characteristics such as delignification, xylan removal yield, crystallinity, accessibility and hydrophobicity are positively related to enzymatic hydrolysis efficiency within a certain range for alkaline post-extracted wheat straw. The results demonstrated that autohydrolysis coupled with alkaline post-extraction is an effective and promising method to gain fermentable sugars from biomass. Copyright © 2017 Elsevier Ltd. All rights reserved.

Characterization of trace metal removal products in vertical flow bioreactor substrates at the Mayer Ranch Passive Treatment System in the Tar Creek Superfund Site.

PubMed

LaBar, Julie A; Nairn, Robert W

2018-05-01

A passive treatment system (PTS), including two parallel vertical flow bioreactors (VFBR), was constructed in 2008 for the treatment of unabated net-alkaline ferruginous mine drainage in the Tar Creek Superfund Site in northeastern Oklahoma. Water quality data collected since the PTS began operation indicate significant removal of trace metals in the VFBR. Results of a sequential extraction procedure (SEP) performed on substrate samples showed that the majority of Cd, Co, Fe, Ni, Pb, and Zn were retained in the refractory organic/sulfide fraction. Subsequent acid volatile sulfide/simultaneously extracted metals (AVS/SEM) analyses confirmed the retention of Cd, Fe, Pb, and Zn as sulfides, but Co and Ni results were less certain. The majority of trace metals were retained as insoluble products in the VFBR, while up to 20% of most of the trace metals were retained in soluble, bioavailable fractions. Nearly 70% of Mn was retained in the soluble and bioavailable exchangeable, carbonate, and labile organic fractions. Copyright © 2018 Elsevier Ltd. All rights reserved.

Flow analysis techniques for phosphorus: an overview.

PubMed

Estela, José Manuel; Cerdà, Víctor

2005-04-15

A bibliographical review on the implementation and the results obtained in the use of different flow analytical techniques for the determination of phosphorus is carried out. The sources, occurrence and importance of phosphorus together with several aspects regarding the analysis and terminology used in the determination of this element are briefly described. A classification as well as a brief description of the basis, advantages and disadvantages of the different existing flow techniques, namely; segmented flow analysis (SFA), flow injection analysis (FIA), sequential injection analysis (SIA), all injection analysis (AIA), batch injection analysis (BIA), multicommutated FIA (MCFIA), multisyringe FIA (MSFIA) and multipumped FIA (MPFIA) is also carried out. The most relevant manuscripts regarding the analysis of phosphorus by means of flow techniques are herein classified according to the detection instrumental technique used with the aim to facilitate their study and obtain an overall scope. Finally, the analytical characteristics of numerous flow-methods reported in the literature are provided in the form of a table and their applicability to samples with different matrixes, namely water samples (marine, river, estuarine, waste, industrial, drinking, etc.), soils leachates, plant leaves, toothpaste, detergents, foodstuffs (wine, orange juice, milk), biological samples, sugars, fertilizer, hydroponic solutions, soils extracts and cyanobacterial biofilms are tabulated.

Investigation of Multiphase Flow in a Packed Bed Reactor Under Microgravity Conditions

NASA Technical Reports Server (NTRS)

Lian, Yongsheng; Motil, Brian; Rame, Enrique

2016-01-01

In this paper we study the two-phase flow phenomena in a packed bed reactor using an integrated experimental and numerical method. The cylindrical bed is filled with uniformly sized spheres. In the experiment water and air are injected into the bed simultaneously. The pressure distribution along the bed will be measured. The numerical simulation is based on a two-phase flow solver which solves the Navier-Stokes equations on Cartesian grids. A novel coupled level set and moment of fluid method is used to construct the interface. A sequential method is used to position spheres in the cylinder. Preliminary experimental results showed that the tested flow rates resulted in pulse flow. The numerical simulation revealed that air bubbles could merge into larger bubbles and also could break up into smaller bubbles to pass through the pores in the bed. Preliminary results showed that flow passed through regions where the porosity is high. Comparison between the experimental and numerical results in terms of pressure distributions at different flow injection rates will be conducted. Comparison of flow phenomena under terrestrial gravity and microgravity will be made.

Redesigning flow injection after 40 years of development: Flow programming.

PubMed

Ruzicka, Jaromir Jarda

2018-01-01

Automation of reagent based assays, by means of Flow Injection (FI), is based on sample processing, in which a sample flows continuously towards and through a detector for quantification of the target analyte. The Achilles heel of this methodology, the legacy of Auto Analyzer®, is continuous reagent consumption, and continuous generation of chemical waste. However, flow programming, assisted by recent advances in precise pumping, combined with the lab-on-valve technique, allows the FI manifold to be designed around a single confluence point through which sample and reagents are sequentially directed by means of a series of flow reversals. This approach results in sample/reagent mixing analogous to the traditional FI, reduces sample and reagent consumption, and uses the stop flow technique for enhancement of the yield of chemical reactions. The feasibility of programmable Flow Injection (pFI) is documented by example of commonly used spectrophotometric assays of, phosphate, nitrate, nitrite and glucose. Experimental details and additional information are available in online tutorial http://www.flowinjectiontutorial.com/. Copyright © 2017 Elsevier B.V. All rights reserved.

Retinal blood vessel extraction using tunable bandpass filter and fuzzy conditional entropy.

PubMed

Sil Kar, Sudeshna; Maity, Santi P

2016-09-01

Extraction of blood vessels on retinal images plays a significant role for screening of different opthalmologic diseases. However, accurate extraction of the entire and individual type of vessel silhouette from the noisy images with poorly illuminated background is a complicated task. To this aim, an integrated system design platform is suggested in this work for vessel extraction using a sequential bandpass filter followed by fuzzy conditional entropy maximization on matched filter response. At first noise is eliminated from the image under consideration through curvelet based denoising. To include the fine details and the relatively less thick vessel structures, the image is passed through a bank of sequential bandpass filter structure optimized for contrast enhancement. Fuzzy conditional entropy on matched filter response is then maximized to find the set of multiple optimal thresholds to extract the different types of vessel silhouettes from the background. Differential Evolution algorithm is used to determine the optimal gain in bandpass filter and the combination of the fuzzy parameters. Using the multiple thresholds, retinal image is classified as the thick, the medium and the thin vessels including neovascularization. Performance evaluated on different publicly available retinal image databases shows that the proposed method is very efficient in identifying the diverse types of vessels. Proposed method is also efficient in extracting the abnormal and the thin blood vessels in pathological retinal images. The average values of true positive rate, false positive rate and accuracy offered by the method is 76.32%, 1.99% and 96.28%, respectively for the DRIVE database and 72.82%, 2.6% and 96.16%, respectively for the STARE database. Simulation results demonstrate that the proposed method outperforms the existing methods in detecting the various types of vessels and the neovascularization structures. The combination of curvelet transform and tunable bandpass filter is found to be very much effective in edge enhancement whereas fuzzy conditional entropy efficiently distinguishes vessels of different widths. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

An on-line potentiometric sequential injection titration process analyser for the determination of acetic acid.

PubMed

van Staden, J F; Mashamba, Mulalo G; Stefan, Raluca I

2002-09-01

An on-line potentiometric sequential injection titration process analyser for the determination of acetic acid is proposed. A solution of 0.1 mol L(-1) sodium chloride is used as carrier. Titration is achieved by aspirating acetic acid samples between two strong base-zone volumes into a holding coil and by channelling the stack of well-defined zones with flow reversal through a reaction coil to a potentiometric sensor where the peak widths were measured. A linear relationship between peak width and logarithm of the acid concentration was obtained in the range 1-9 g/100 mL. Vinegar samples were analysed without any sample pre-treatment. The method has a relative standard deviation of 0.4% with a sample frequency of 28 samples per hour. The results revealed good agreement between the proposed sequential injection and an automated batch titration method.

The BLAZE language: A parallel language for scientific programming

NASA Technical Reports Server (NTRS)

Mehrotra, P.; Vanrosendale, J.

1985-01-01

A Pascal-like scientific programming language, Blaze, is described. Blaze contains array arithmetic, forall loops, and APL-style accumulation operators, which allow natural expression of fine grained parallelism. It also employs an applicative or functional procedure invocation mechanism, which makes it easy for compilers to extract coarse grained parallelism using machine specific program restructuring. Thus Blaze should allow one to achieve highly parallel execution on multiprocessor architectures, while still providing the user with onceptually sequential control flow. A central goal in the design of Blaze is portability across a broad range of parallel architectures. The multiple levels of parallelism present in Blaze code, in principle, allow a compiler to extract the types of parallelism appropriate for the given architecture while neglecting the remainder. The features of Blaze are described and shows how this language would be used in typical scientific programming.

Improved aqueous scrubber for collection of soluble atmospheric trace gases

NASA Technical Reports Server (NTRS)

Cofer, W. R., III; Talbot, R. W.; Collins, V. G.

1985-01-01

A new concentration technique for the extraction and enrichment of water-soluble atmospheric trace gases has been developed. The gas scrubbing technique efficiently extracts soluble gases from a large volume flow rate of air sample into a small volume of refluxed trapping solution. The gas scrubber utilizes a small nebulizing nozzle that mixes the incoming air with an aqueous extracting solution to form an air/droplet mist. The mist provides excellent interfacial surface areas for mass transfer. The resulting mist sprays upward through the reaction chamber until it impinges upon a hydrophobic membrane that virtually blocks the passage of droplets but offers little resistance to the existing gas flow. Droplets containing the scrubbed gases coalesce on the membrane and drip back into the reservoir for further refluxing. After a suitable concentration period, the extracting solution containing the analyte can be withdrawn for analysis. The nebulization-reflex concentration technique is more efficient (maximum flow of gas through the minimum volume of extractant) than conventional bubbler/impinger gas extraction techniques and is offered as an alternative method.

A sequential analysis of classroom discourse in Italian primary schools: the many faces of the IRF pattern.

PubMed

Molinari, Luisa; Mameli, Consuelo; Gnisci, Augusto

2013-09-01

A sequential analysis of classroom discourse is needed to investigate the conditions under which the triadic initiation-response-feedback (IRF) pattern may host different teaching orientations. The purpose of the study is twofold: first, to describe the characteristics of classroom discourse and, second, to identify and explore the different interactive sequences that can be captured with a sequential statistical analysis. Twelve whole-class activities were video recorded in three Italian primary schools. We observed classroom interaction as it occurs naturally on an everyday basis. In total, we collected 587 min of video recordings. Subsequently, 828 triadic IRF patterns were extracted from this material and analysed with the programme Generalized Sequential Query (GSEQ). The results indicate that classroom discourse may unfold in different ways. In particular, we identified and described four types of sequences. Dialogic sequences were triggered by authentic questions, and continued through further relaunches. Monologic sequences were directed to fulfil the teachers' pre-determined didactic purposes. Co-constructive sequences fostered deduction, reasoning, and thinking. Scaffolding sequences helped and sustained children with difficulties. The application of sequential analyses allowed us to show that interactive sequences may account for a variety of meanings, thus making a significant contribution to the literature and research practice in classroom discourse. © 2012 The British Psychological Society.

Sequential continuous flow processes for the oxidation of amines and azides by using HOF·MeCN.

PubMed

McPake, Christopher B; Murray, Christopher B; Sandford, Graham

2012-02-13

The generation and use of the highly potent oxidising agent HOF·MeCN in a controlled single continuous flow process is described. Oxidations of amines and azides to corresponding nitrated systems by using fluorine gas, water and acetonitrile by sequential gas-liquid/liquid-liquid continuous flow procedures are reported. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Polymeric microchip for the simultaneous determination of anions and cations by hydrodynamic injection using a dual-channel sequential injection microchip electrophoresis system.

PubMed

Gaudry, Adam J; Nai, Yi Heng; Guijt, Rosanne M; Breadmore, Michael C

2014-04-01

A dual-channel sequential injection microchip capillary electrophoresis system with pressure-driven injection is demonstrated for simultaneous separations of anions and cations from a single sample. The poly(methyl methacrylate) (PMMA) microchips feature integral in-plane contactless conductivity detection electrodes. A novel, hydrodynamic "split-injection" method utilizes background electrolyte (BGE) sheathing to gate the sample flows, while control over the injection volume is achieved by balancing hydrodynamic resistances using external hydrodynamic resistors. Injection is realized by a unique flow-through interface, allowing for automated, continuous sampling for sequential injection analysis by microchip electrophoresis. The developed system was very robust, with individual microchips used for up to 2000 analyses with lifetimes limited by irreversible blockages of the microchannels. The unique dual-channel geometry was demonstrated by the simultaneous separation of three cations and three anions in individual microchannels in under 40 s with limits of detection (LODs) ranging from 1.5 to 24 μM. From a series of 100 sequential injections the %RSDs were determined for every fifth run, resulting in %RSDs for migration times that ranged from 0.3 to 0.7 (n = 20) and 2.3 to 4.5 for peak area (n = 20). This system offers low LODs and a high degree of reproducibility and robustness while the hydrodynamic injection eliminates electrokinetic bias during injection, making it attractive for a wide range of rapid, sensitive, and quantitative online analytical applications.

Constraining OCT with Knowledge of Device Design Enables High Accuracy Hemodynamic Assessment of Endovascular Implants.

PubMed

O'Brien, Caroline C; Kolandaivelu, Kumaran; Brown, Jonathan; Lopes, Augusto C; Kunio, Mie; Kolachalama, Vijaya B; Edelman, Elazer R

2016-01-01

Stacking cross-sectional intravascular images permits three-dimensional rendering of endovascular implants, yet introduces between-frame uncertainties that limit characterization of device placement and the hemodynamic microenvironment. In a porcine coronary stent model, we demonstrate enhanced OCT reconstruction with preservation of between-frame features through fusion with angiography and a priori knowledge of stent design. Strut positions were extracted from sequential OCT frames. Reconstruction with standard interpolation generated discontinuous stent structures. By computationally constraining interpolation to known stent skeletons fitted to 3D 'clouds' of OCT-Angio-derived struts, implant anatomy was resolved, accurately rendering features from implant diameter and curvature (n = 1 vessels, r2 = 0.91, 0.90, respectively) to individual strut-wall configurations (average displacement error ~15 μm). This framework facilitated hemodynamic simulation (n = 1 vessel), showing the critical importance of accurate anatomic rendering in characterizing both quantitative and basic qualitative flow patterns. Discontinuities with standard approaches systematically introduced noise and bias, poorly capturing regional flow effects. In contrast, the enhanced method preserved multi-scale (local strut to regional stent) flow interactions, demonstrating the impact of regional contexts in defining the hemodynamic consequence of local deployment errors. Fusion of planar angiography and knowledge of device design permits enhanced OCT image analysis of in situ tissue-device interactions. Given emerging interests in simulation-derived hemodynamic assessment as surrogate measures of biological risk, such fused modalities offer a new window into patient-specific implant environments.

Paper-based microfluidics with an erodible polymeric bridge giving controlled release and timed flow shutoff.

PubMed

Jahanshahi-Anbuhi, Sana; Henry, Aleah; Leung, Vincent; Sicard, Clémence; Pennings, Kevin; Pelton, Robert; Brennan, John D; Filipe, Carlos D M

2014-01-07

Water soluble pullulan films were formatted into paper-based microfluidic devices, serving as a controlled time shutoff valve. The utility of the valve was demonstrated by a one-step, fully automatic implementation of a complex pesticide assay requiring timed, sequential exposure of an immobilized enzyme layer to separate liquid streams. Pullulan film dissolution and the capillary wicking of aqueous solutions through the device were measured and modeled providing valve design criteria. The films dissolve mainly by surface erosion, meaning the film thickness mainly controls the shutoff time. This method can also provide time-dependent sequential release of reagents without compromising the simplicity and low cost of paper-based devices.

EXTRACTION OF SEDIMENT-BOUND CHLORINATED ORGANIC COMPOUNDS: IMPLICATIONS ON FATE AND HAZARD ASSESSMENT. (R825513C007)

EPA Science Inventory

Five methods were used for the extraction of hexachlorobutadiene and chlorobenzenes from a contaminated estuarine sediment. The following extraction methods were used: Soxhlet extraction, sonication and solvent extraction, sequential solvent extraction, saponification and solv...

Biaxially mechanical tuning of 2-D reversible and irreversible surface topologies through simultaneous and sequential wrinkling.

PubMed

Yin, Jie; Yagüe, Jose Luis; Boyce, Mary C; Gleason, Karen K

2014-02-26

Controlled buckling is a facile means of structuring surfaces. The resulting ordered wrinkling topologies provide surface properties and features desired for multifunctional applications. Here, we study the biaxially dynamic tuning of two-dimensional wrinkled micropatterns under cyclic mechanical stretching/releasing/restretching simultaneously or sequentially. A biaxially prestretched PDMS substrate is coated with a stiff polymer deposited by initiated chemical vapor deposition (iCVD). Applying a mechanical release/restretch cycle in two directions loaded simultaneously or sequentially to the wrinkled system results in a variety of dynamic and tunable wrinkled geometries, the evolution of which is investigated using in situ optical profilometry, numerical simulations, and theoretical modeling. Results show that restretching ordered herringbone micropatterns, created through sequential release of biaxial prestrain, leads to reversible and repeatable surface topography. The initial flat surface and the same wrinkled herringbone pattern are obtained alternatively after cyclic release/restretch processes, owing to the highly ordered structure leaving no avenue for trapping irregular topological regions during cycling as further evidenced by the uniformity of strains distributions and negligible residual strain. Conversely, restretching disordered labyrinth micropatterns created through simultaneous release shows an irreversible surface topology whether after sequential or simultaneous restretching due to creation of irregular surface topologies with regions of highly concentrated strain upon formation of the labyrinth which then lead to residual strains and trapped topologies upon cycling; furthermore, these trapped topologies depend upon the subsequent strain histories as well as the cycle. The disordered labyrinth pattern varies after each cyclic release/restretch process, presenting residual shallow patterns instead of achieving a flat state. The ability to dynamically tune the highly ordered herringbone patterning through mechanical stretching or other actuation makes these wrinkles excellent candidates for tunable multifunctional surfaces properties such as reflectivity, friction, anisotropic liquid flow or boundary layer control.

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

PubMed

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. Copyright © 2013 Elsevier Ltd. All rights reserved.

Functionalized Anodic Aluminum Oxide Membrane–Electrode System for Enzyme Immobilization

PubMed Central

2015-01-01

A nanoporous membrane system with directed flow carrying reagents to sequentially attached enzymes to mimic nature’s enzyme complex system was demonstrated. Genetically modified glycosylation enzyme, OleD Loki variant, was immobilized onto nanometer-scale electrodes at the pore entrances/exits of anodic aluminum oxide membranes through His6-tag affinity binding. The enzyme activity was assessed in two reactions—a one-step “reverse” sugar nucleotide formation reaction (UDP-Glc) and a two-step sequential sugar nucleotide formation and sugar nucleotide-based glycosylation reaction. For the one-step reaction, enzyme specific activity of 6–20 min–1 on membrane supports was seen to be comparable to solution enzyme specific activity of 10 min–1. UDP-Glc production efficiencies as high as 98% were observed at a flow rate of 0.5 mL/min, at which the substrate residence time over the electrode length down pore entrances was matched to the enzyme activity rate. This flow geometry also prevented an unwanted secondary product hydrolysis reaction, as observed in the test homogeneous solution. Enzyme utilization increased by a factor of 280 compared to test homogeneous conditions due to the continuous flow of fresh substrate over the enzyme. To mimic enzyme complex systems, a two-step sequential reaction using OleD Loki enzyme was performed at membrane pore entrances then exits. After UDP-Glc formation at the entrance electrode, aglycon 4-methylumbelliferone was supplied at the exit face of the reactor, affording overall 80% glycosylation efficiency. The membrane platform showed the ability to be regenerated with purified enzyme as well as directly from expression crude, thus demonstrating a single-step immobilization and purification process. PMID:25025628

Development of a low-flow multiplexed interface for capillary electrophoresis/electrospray ion trap mass spectrometry using sequential spray.

PubMed

Chen, Chao-Jung; Li, Fu-An; Her, Guor-Rong

2008-05-01

A multiplexed CE-MS interface using four low-flow sheath liquid ESI sprayers has been developed. Because of the limited space between the low-flow sprayers and the entrance aperture of the ESI source, multichannel analysis is difficult using conventional rotating plate approaches. Instead, a multiplexed low-flow system was achieved by applying an ESI potential sequentially to the four low-flow sprayers, resulting in only one sprayer being sprayed at any given time. The synchronization of the scan event and the voltage relays was accomplished by using the data acquisition signal from the IT mass spectrometer. This synchronization resulted in the ESI voltage being sequentially applied to each of the four sprayers according to the corresponding scan event. With this design, a four-fold increase in analytical throughput was achieved. Because of the use of low-flow interfaces, this multiplexed system has superior sensitivity than a rotating plate design using conventional sheath liquid interfaces. The multiplexed design presented has the potential to be applied to other low-flow multiplexed systems, such as multiplexed capillary LC and multiplexed CEC.

Evaluation of Pollutant Leaching Potential of Coal Ashes for Recycling

NASA Astrophysics Data System (ADS)

Park, D.; Woo, N. C.; Kim, H.; Yoon, H.; Chung, D.

2011-12-01

By 2009, coal ashes produced from coal-based power plants in Korea have been reused as cement supplement materials; however, the rest is mostly disposed in landfills inside the plant properties. Continuous production of coal ashes and limited landfill sites require more recycles of coal ashes as base materials, specifically in constructions of roads and of huge industrial complex. Previous researches showed that coal ashes could contain various metals such as arsenic(As), chromium(Cr), lead(Pb), nickel(Ni), selenium(Se), etc. In this study, we collected four types of bottom ashes and two of fly ashes from four coal-based power plants. These ash samples were tested with distilled water through the column leaching process in oxidized conditions. The column test results were compared with those of total digestion, sequential extraction processes and TCLP. Concentrations of metals in outflows from columns are generally greater in fly ashes than in bottom ashes, specifically for As, Se, B, Sr and SO4. Only one fly ash (J2-F) shows high concentrations of arsenic and selenium in leachate. Sequential extraction results indicate that these metals are in readily soluble forms, such as adsorbed, carbonated, and reducible forms. Results of TCLP analysis indicate no potential contaminants leached from the ashes. In conclusion, recycling of coal combustion ashes could be encouraged with proper tests such as sequential and leaching experiments.

Development of a syringe pump assisted dynamic headspace sampling technique for needle trap device.

PubMed

Eom, In-Yong; Niri, Vadoud H; Pawliszyn, Janusz

2008-07-04

This paper describes a new approach that combines needle trap devices (NTDs) with a dynamic headspace sampling technique (purge and trap) using a bidirectional syringe pump. The needle trap device is a 22-G stainless steel needle 3.5-in. long packed with divinylbenzene sorbent particles. The same sized needle, without packing, was used for purging purposes. We chose an aqueous mixture of benzene, toluene, ethylbenzene, and p-xylene (BTEX) and developed a sequential purge and trap (SPNT) method, in which sampling (trapping) and purging cycles were performed sequentially by the use of syringe pump with different distribution channels. In this technique, a certain volume (1 mL) of headspace was sequentially sampled using the needle trap; afterwards, the same volume of air was purged into the solution at a high flow rate. The proposed technique showed an effective extraction compared to the continuous purge and trap technique, with a minimal dilution effect. Method evaluation was also performed by obtaining the calibration graphs for aqueous BTEX solutions in the concentration range of 1-250 ng/mL. The developed technique was compared to the headspace solid-phase microextraction method for the analysis of aqueous BTEX samples. Detection limits as low as 1 ng/mL were obtained for BTEX by NTD-SPNT.

Development of a rapid method for the sequential extraction and subsequent quantification of fatty acids and sugars from avocado mesocarp tissue.

PubMed

Meyer, Marjolaine D; Terry, Leon A

2008-08-27

Methods devised for oil extraction from avocado (Persea americana Mill.) mesocarp (e.g., Soxhlet) are usually lengthy and require operation at high temperature. Moreover, methods for extracting sugars from avocado tissue (e.g., 80% ethanol, v/v) do not allow for lipids to be easily measured from the same sample. This study describes a new simple method that enabled sequential extraction and subsequent quantification of both fatty acids and sugars from the same avocado mesocarp tissue sample. Freeze-dried mesocarp samples of avocado cv. Hass fruit of different ripening stages were extracted by homogenization with hexane and the oil extracts quantified for fatty acid composition by GC. The resulting filter residues were readily usable for sugar extraction with methanol (62.5%, v/v). For comparison, oil was also extracted using the standard Soxhlet technique and the resulting thimble residue extracted for sugars as before. An additional experiment was carried out whereby filter residues were also extracted using ethanol. Average oil yield using the Soxhlet technique was significantly (P < 0.05) higher than that obtained by homogenization with hexane, although the difference remained very slight, and fatty acid profiles of the oil extracts following both methods were very similar. Oil recovery improved with increasing ripeness of the fruit with minor differences observed in the fatty acid composition during postharvest ripening. After lipid removal, methanolic extraction was superior in recovering sucrose and perseitol as compared to 80% ethanol (v/v), whereas mannoheptulose recovery was not affected by solvent used. The method presented has the benefits of shorter extraction time, lower extraction temperature, and reduced amount of solvent and can be used for sequential extraction of fatty acids and sugars from the same sample.

A novel star extraction method based on modified water flow model

NASA Astrophysics Data System (ADS)

Zhang, Hao; Niu, Yanxiong; Lu, Jiazhen; Ouyang, Zibiao; Yang, Yanqiang

2017-11-01

Star extraction is the essential procedure for attitude measurement of star sensor. The great challenge for star extraction is to segment star area exactly from various noise and background. In this paper, a novel star extraction method based on Modified Water Flow Model(MWFM) is proposed. The star image is regarded as a 3D terrain. The morphology is adopted for noise elimination and Tentative Star Area(TSA) selection. Star area can be extracted through adaptive water flowing within TSAs. This method can achieve accurate star extraction with improved efficiency under complex conditions such as loud noise and uneven backgrounds. Several groups of different types of star images are processed using proposed method. Comparisons with existing methods are conducted. Experimental results show that MWFM performs excellently under different imaging conditions. The star extraction rate is better than 95%. The star centroid accuracy is better than 0.075 pixels. The time-consumption is also significantly reduced.

Automated process for solvent separation of organic/inorganic substance

DOEpatents

Schweighardt, F.K.

1986-07-29

There is described an automated process for the solvent separation of organic/inorganic substances that operates continuously and unattended and eliminates potential errors resulting from subjectivity and the aging of the sample during analysis. In the process, metered amounts of one or more solvents are passed sequentially through a filter containing the sample under the direction of a microprocessor control apparatus. The mixture in the filter is agitated by ultrasonic cavitation for a timed period and the filtrate is collected. The filtrate of each solvent extraction is collected individually and the residue on the filter element is collected to complete the extraction process. 4 figs.

Automated process for solvent separation of organic/inorganic substance

DOEpatents

Schweighardt, Frank K.

1986-01-01

There is described an automated process for the solvent separation of organic/inorganic substances that operates continuously and unattended and eliminates potential errors resulting from subjectivity and the aging of the sample during analysis. In the process, metered amounts of one or more solvents are passed sequentially through a filter containing the sample under the direction of a microprocessor control apparatus. The mixture in the filter is agitated by ultrasonic cavitation for a timed period and the filtrate is collected. The filtrate of each solvent extraction is collected individually and the residue on the filter element is collected to complete the extraction process.

Automated apparatus for solvent separation of a coal liquefaction product stream

DOEpatents

Schweighardt, Frank K.

1985-01-01

An automated apparatus for the solvent separation of a coal liquefaction product stream that operates continuously and unattended and eliminates potential errors resulting from subjectivity and the aging of the sample during analysis. In use of the apparatus, metered amounts of one or more solvents are passed sequentially through a filter containing the sample under the direction of a microprocessor control means. The mixture in the filter is agitated by means of ultrasonic cavitation for a timed period and the filtrate is collected. The filtrate of each solvent extraction is collected individually and the residue on the filter element is collected to complete the extraction process.

Does the process map influence the outcome of quality improvement work? A comparison of a sequential flow diagram and a hierarchical task analysis diagram.

PubMed

Colligan, Lacey; Anderson, Janet E; Potts, Henry W W; Berman, Jonathan

2010-01-07

Many quality and safety improvement methods in healthcare rely on a complete and accurate map of the process. Process mapping in healthcare is often achieved using a sequential flow diagram, but there is little guidance available in the literature about the most effective type of process map to use. Moreover there is evidence that the organisation of information in an external representation affects reasoning and decision making. This exploratory study examined whether the type of process map - sequential or hierarchical - affects healthcare practitioners' judgments. A sequential and a hierarchical process map of a community-based anti coagulation clinic were produced based on data obtained from interviews, talk-throughs, attendance at a training session and examination of protocols and policies. Clinic practitioners were asked to specify the parts of the process that they judged to contain quality and safety concerns. The process maps were then shown to them in counter-balanced order and they were asked to circle on the diagrams the parts of the process where they had the greatest quality and safety concerns. A structured interview was then conducted, in which they were asked about various aspects of the diagrams. Quality and safety concerns cited by practitioners differed depending on whether they were or were not looking at a process map, and whether they were looking at a sequential diagram or a hierarchical diagram. More concerns were identified using the hierarchical diagram compared with the sequential diagram and more concerns were identified in relation to clinical work than administrative work. Participants' preference for the sequential or hierarchical diagram depended on the context in which they would be using it. The difficulties of determining the boundaries for the analysis and the granularity required were highlighted. The results indicated that the layout of a process map does influence perceptions of quality and safety problems in a process. In quality improvement work it is important to carefully consider the type of process map to be used and to consider using more than one map to ensure that different aspects of the process are captured.

Enrichment desired quality chitosan fraction and advance yield by sequential static and static-dynamic supercritical CO2.

PubMed

Hsieh, Yi-Yin; Chin, Hui Yen; Tsai, Min-Lang

2015-11-20

This study aimed to establish the sequential static and static-dynamic supercritical carbon dioxide (SDCO2) fractionation conditions to obtain a higher yield and desired chitosan with lower polydispersity index (PDI) and higher degree of deacetylation (DD). The yield increased with increasing DD of used chitosan and amount of cosolvent. The yield of acetic acid cosolvent was higher than those of malic and citric acid cosolvents. SDCO2, compared to static supercritical carbon dioxide, has higher yield. The yield of extracted chitosan was 5.82-14.70% by SDCO2/acetic acid, which increases with increasing pressure. The DD of fractionated chitosan increased from 66.1% to 70.81-85.33%, while the PDI decreased from 3.97 to 1.69-3.16. The molecular weight changed from 622kDa to 412-649kDa, which increased as density of supercritical carbon dioxide increases. Hence, higher DD and lower PDI extracted chitosan can be obtained through controlling the temperature and pressure of SDCO2. Copyright © 2015 Elsevier Ltd. All rights reserved.

The limit of the film extraction technique for annular two-phase flow in a small tube

DOE Office of Scientific and Technical Information (OSTI.GOV)

Helm, D.E.; Lopez de Bertodano, M.; Beus, S.G.

1999-07-01

The limit of the liquid film extraction technique was identified in air-water and Freon-113 annular two-phase flow loops. The purpose of this research is to find the limit of the entrainment rate correlation obtained by Lopez de Bertodano et. al. (1998). The film extraction technique involves the suction of the liquid film through a porous tube and has been widely used to obtain annular flow entrainment and entrainment rate data. In these experiments there are two extraction probes. After the first extraction the entrained droplets in the gas core deposit on the tube wall. A new liquid film develops entirelymore » from liquid deposition and a second liquid film extraction is performed. While it is assumed that the entire liquid film is removed after the first extraction unit, this is not true for high liquid flow. At high liquid film flows the interfacial structure of the film becomes frothy. Then the entire liquid film cannot be removed at the first extraction unit, but continues on and is extracted at the second extraction unit. A simple model to characterize the limit of the extraction technique was obtained based on the hypothesis that the transition occurs due to a change in the wave structure. The resulting dimensionless correlation agrees with the data.« less

The limit of the film extraction technique for annular two-phase flow in a small tube

DOE Office of Scientific and Technical Information (OSTI.GOV)

Helm, D.E.; Lopez de Bertodano, M.; Beus, S.G.

1999-07-01

The limit of the liquid film extraction technique was identified in air-water and Freon-113 annular two-phase flow loops. The purpose of this research is to find the limit of the entrainment rate correlation obtained by Lopez de Bertodano et al. (1998). The film extraction technique involves the suction of the liquid film through a porous tube and has been widely used to obtain annular flow entrainment and entrainment rate data. In the experiments there are two extraction probes. After the first extraction the entrained droplets in the gas core deposit on the tube wall. A new liquid film develops entirelymore » from liquid deposition and a second liquid film extraction is performed. While it is assumed that the entire liquid film is removed after the first extraction unit, this is not true for high liquid flow. At high liquid film flows the interfacial structure of the film becomes frothy. Then the entire liquid film cannot be removed at the first extraction unit, but continues on and is extracted at the second extraction unit. A simple model to characterize the limit of the extraction technique was obtained based on the hypothesis that the transition occurs due to a change in the wave structure. The resulting dimensionless correlation agrees with the data.« less

Automated high-throughput flow-through real-time diagnostic system

DOEpatents

Regan, John Frederick

2012-10-30

An automated real-time flow-through system capable of processing multiple samples in an asynchronous, simultaneous, and parallel fashion for nucleic acid extraction and purification, followed by assay assembly, genetic amplification, multiplex detection, analysis, and decontamination. The system is able to hold and access an unlimited number of fluorescent reagents that may be used to screen samples for the presence of specific sequences. The apparatus works by associating extracted and purified sample with a series of reagent plugs that have been formed in a flow channel and delivered to a flow-through real-time amplification detector that has a multiplicity of optical windows, to which the sample-reagent plugs are placed in an operative position. The diagnostic apparatus includes sample multi-position valves, a master sample multi-position valve, a master reagent multi-position valve, reagent multi-position valves, and an optical amplification/detection system.

Sequential solvent extraction for forms of antimony in five selected coals

USGS Publications Warehouse

Qi, C.; Liu, Gaisheng; Kong, Y.; Chou, C.-L.; Wang, R.

2008-01-01

Abundance of antimony in bulk samples has been determined in five selected coals, three coals from Huaibei Coalfield, Anhui, China, and two from the Illinois Basin in the United States. The Sb abundance in these samples is in the range of 0.11-0.43 ??g/g. The forms of Sb in coals were studied by sequential solvent extraction. The six forms of Sb are water soluble, ion changeable, organic matter bound, carbonate bound, silicate bound, and sulfide bound. Results of sequential extraction show that silicate-bound Sb is the most abundant form in these coals. Silicate- plus sulfide-bound Sb accounts for more than half of the total Sb in all coals. Bituminous coals are higher in organic matterbound Sb than anthracite and natural coke, indicating that the Sb in the organic matter may be incorporated into silicate and sulfide minerals during metamorphism. ?? 2008 by The University of Chicago. All rights reserved.

The BLAZE language - A parallel language for scientific programming

NASA Technical Reports Server (NTRS)

Mehrotra, Piyush; Van Rosendale, John

1987-01-01

A Pascal-like scientific programming language, BLAZE, is described. BLAZE contains array arithmetic, forall loops, and APL-style accumulation operators, which allow natural expression of fine grained parallelism. It also employs an applicative or functional procedure invocation mechanism, which makes it easy for compilers to extract coarse grained parallelism using machine specific program restructuring. Thus BLAZE should allow one to achieve highly parallel execution on multiprocessor architectures, while still providing the user with conceptually sequential control flow. A central goal in the design of BLAZE is portability across a broad range of parallel architectures. The multiple levels of parallelism present in BLAZE code, in principle, allow a compiler to extract the types of parallelism appropriate for the given architecture while neglecting the remainder. The features of BLAZE are described and it is shown how this language would be used in typical scientific programming.

Photo-induced chemiluminometric determination of Karbutilate in a continuous-flow multicommutation assembly.

PubMed

Amorim, C M P G; Albert-García, J R; Montenegro, M C B S; Araújo, A N; Calatayud, J Martínez

2007-01-17

The present paper deals with the chemiluminescent determination of the herbicide Karbutilate on the basis of its previous photodegradation by using a low-pressure Hg lamp as UV source in a continuous-flow multicommutation assembly (a solenoid valves set). The pesticide solution was segmented by a solenoid valve and sequentially alternated with segments of the 0.001 mol l(-1) of NaOH solution, the suitable media for the formation of photo-fragments; then it passes through the photo-reactor and was lead to the flow-cell after being divided in small segments which were sequentially alternated with the oxidizing system; 2 x 10(-5) mol l(-1) of potassium permanganate in 0.2% pyrophosphoric acid. The studied calibration range, from 0.1 microg l(-1) to 65 mg l(-1), resulted in a linear behaviour over the range 20 microg l(-1)-20 mg l(-1) and fitting the linear equation: I=(1180+/-30)C+(15+/-5) with the correlation coefficient 0.9998. The limit of detection was 10 microg l(-1) and the sample throughput 17 h(-1). After testing the influence of a large series of potential interfering species, the method was applied to water and human urine samples.

Spatial and Temporal Variability in Sediment P Distribution and Speciation in Coastal Louisiana

NASA Astrophysics Data System (ADS)

Bowes, K.; White, J. R.; Maiti, K.

2017-12-01

Excess loading of phosphorus (P) and nitrogen (N) into aquatic systems leads to degradation of water quality and diminished important ecosystem services. In the Northern Gulf of Mexico (NGOM), excess P and N loading has led to a seasonally present hypoxic area with less than 2 mg/L O2 in bottom waters, approximating 26,000 km2 in 2017. A sequential extraction (SEDEX) method was performed on surficial sediments from five different coastal and shelf sites as a function of distance from the Mississippi River mouth in the NGOM. To better quantify temporal variability in P distribution and speciation, samples were collected during both low (August) and high (May) river flow regimes. Sequential extraction techniques have been successful in separating pools of P into exchangeable or loosely sorbed P, Fe-P, Authigenic-P, Detrital-P, and Organic-P. Preliminary results suggest Authigenic-P is approximately 3-6 times more concentrated in NGOM sediments than all other P pools. Fractionation results did not show a consistent trend with sediment depth. Sediment samples had an average moisture content of 58.72% ± 12.06% and an average bulk density of 0.582 ± 0.275 g/cm3. Continued analysis of P speciation and cycling in NGOM sediments is critical in understanding the driving force behind coastal eutrophication and informing effective nutrient management strategies.

Phosphorus Concentrations in Sequentially Fractionated Soil Samples as Affected by Digestion Methods

PubMed Central

do Nascimento, Carlos A. C.; Pagliari, Paulo H.; Schmitt, Djalma; He, Zhongqi; Waldrip, Heidi

2015-01-01

Sequential fractionation has helped improving our understanding of the lability and bioavailability of P in soil. Nevertheless, there have been no reports on how manipulation of the different fractions prior to analyses affects the total P (TP) concentrations measured. This study investigated the effects of sample digestion, filtration, and acidification on the TP concentrations determined by ICP-OES in 20 soil samples. Total P in extracts were either determined without digestion by ICP-OES, or ICP-OES following block digestion, or autoclave digestion. The effects of sample filtration, and acidification on undigested alkaline extracts prior to ICP-OES were also evaluated. Results showed that, TP concentrations were greatest in the block-digested extracts, though the variability introduced by the block-digestion was the highest. Acidification of NaHCO3 extracts resulted in lower TP concentrations, while acidification of NaOH randomly increased or decreased TP concentrations. The precision observed with ICP-OES of undigested extracts suggests this should be the preferred method for TP determination in sequentially extracted samples. Thus, observations reported in this work would be helpful in appropriate sample handling for P determination, thereby improving the precision of P determination. The results are also useful for literature data comparison and discussion when there are differences in sample treatments. PMID:26647644

A Deep Learning based Approach to Reduced Order Modeling of Fluids using LSTM Neural Networks

NASA Astrophysics Data System (ADS)

Mohan, Arvind; Gaitonde, Datta

2017-11-01

Reduced Order Modeling (ROM) can be used as surrogates to prohibitively expensive simulations to model flow behavior for long time periods. ROM is predicated on extracting dominant spatio-temporal features of the flow from CFD or experimental datasets. We explore ROM development with a deep learning approach, which comprises of learning functional relationships between different variables in large datasets for predictive modeling. Although deep learning and related artificial intelligence based predictive modeling techniques have shown varied success in other fields, such approaches are in their initial stages of application to fluid dynamics. Here, we explore the application of the Long Short Term Memory (LSTM) neural network to sequential data, specifically to predict the time coefficients of Proper Orthogonal Decomposition (POD) modes of the flow for future timesteps, by training it on data at previous timesteps. The approach is demonstrated by constructing ROMs of several canonical flows. Additionally, we show that statistical estimates of stationarity in the training data can indicate a priori how amenable a given flow-field is to this approach. Finally, the potential and limitations of deep learning based ROM approaches will be elucidated and further developments discussed.

Bedform movement recorded by sequential single-beam surveys in tidal rivers

USGS Publications Warehouse

Dinehart, R.L.

2002-01-01

A portable system for bedform-mapping was evaluated in the delta of the lower Sacramento and San Joaquin Rivers, California, from 1998 to 2000. Bedform profiles were surveyed with a two-person crew using an array of four single-beam transducers on boats about 6 m in length. Methods for processing the bedform profiles into maps with geographic coordinates were developed for spreadsheet programs and surface-contouring software. Straight reaches were surveyed every few days or weeks to determine locations of sand deposition, net transport directions, flow thresholds for bedform regimes, and bedform-transport rates. In one channel of unidirectional flow, the portable system was used to record changes in bedform regime through minor fluctuations of low discharge, and through high discharges near channel capacity. In another channel with reversing flows from tides, the portable system recorded directions of net bedload-transport that would be undetectable by standard bedload sampling alone.

Semiautomatic sequential extraction of polycyclic aromatic hydrocarbons and elemental bio-accessible fraction by accelerated solvent extraction on a single particulate matter sample.

PubMed

Astolfi, Maria Luisa; Di Filippo, Patrizia; Gentili, Alessandra; Canepari, Silvia

2017-11-01

We describe the optimization and validation of a sequential extractive method for the determination of the polycyclic aromatic hydrocarbons (PAHs) and elements (Al, As, Cd, Cr, Cu, Fe, Mn, Ni, Pb, Se, V and Zn) that are chemically fractionated into bio-accessible and mineralized residual fractions on a single particulate matter filter. The extraction is performed by automatic accelerated solvent extraction (ASE); samples are sequentially treated with dichloromethane/acetone (4:1) for PAHs extraction and acetate buffer (0.01M; pH 4.5) for elements extraction (bio-accessible fraction). The remaining solid sample is then collected and subjected to acid digestion with HNO 3 :H 2 O 2 (2:1) to determine the mineralized residual element fraction. We also describe a homemade ASE cell that reduces the blank values for most elements; in this cell, the steel frit was replaced by a Teflon pierced disk and a Teflon cylinder was used as the filler. The performance of the proposed method was evaluated in terms of recovery from standard reference material (SRM 1648 and SRM 1649a) and repeatability. The equivalence between the new ASE method and conventional methods was verified for PAHs and for bio-accessible and mineralized residual fractions of elements on PM 10 twin filters. Copyright © 2017 Elsevier B.V. All rights reserved.

Modeling of a Sequential Two-Stage Combustor

NASA Technical Reports Server (NTRS)

Hendricks, R. C.; Liu, N.-S.; Gallagher, J. R.; Ryder, R. C.; Brankovic, A.; Hendricks, J. A.

2005-01-01

A sequential two-stage, natural gas fueled power generation combustion system is modeled to examine the fundamental aerodynamic and combustion characteristics of the system. The modeling methodology includes CAD-based geometry definition, and combustion computational fluid dynamics analysis. Graphical analysis is used to examine the complex vortical patterns in each component, identifying sources of pressure loss. The simulations demonstrate the importance of including the rotating high-pressure turbine blades in the computation, as this results in direct computation of combustion within the first turbine stage, and accurate simulation of the flow in the second combustion stage. The direct computation of hot-streaks through the rotating high-pressure turbine stage leads to improved understanding of the aerodynamic relationships between the primary and secondary combustors and the turbomachinery.

Three-dimensional Models of Hydrothermal Circulation through a Seamount Network in Fast-spreading Crust

NASA Astrophysics Data System (ADS)

Fisher, A. T.; Lauer, R. M.; Winslow, D. M.

2015-12-01

There is a region of 20-24 M.y. old seafloor on the eastern flank of the East Pacific Rise, offshore of Costa Rica, where the advective heat loss from the crust is 60-85% of lithospheric. Much of this advective flux occurs through basement outcrops that penetrate regionally thick sediments, but rates and patterns of hydrothermal circulation in this area are poorly understood. We have run a series of numerical simulations of coupled fluid-heat transport to assess how crustal aquifer and outcrop properties and the distance(s) between outcrops control ridge-flank hydrothermal flows in this setting. Extracting a large fraction of lithospheric heat through this process requires crustal aquifer permeability on the order of 10-10 to 10-9 m2, values considerably higher than seen on other ridge flanks (where advective heat extraction is less efficient). In simulations using two crustal outcrops having a different size, vigorous discharge of outcrop-to-outcrop flow is favored through the smaller and/or less permeable outcrop. In addition, simulations with a larger grid (40 km square versus 20 km square) result in higher fluid flow rates, apparently because there is more heat to be mined by flow between the outcrops. For simulations matching regional heat extraction observations, the outcrop-to-outcrop flow rates from the smaller outcrops are 1,000-3,000 kg/s (for the smaller grids) and 2,000-10,000 kg/s (for larger grids), values consistent with predictions made on the basis of a regional heat flux budget. In many simulations, local convection in and out of individual, large outcrops also removes a significant fraction of lithospheric heat. Additional simulations were conducted with three or four outcrops per simulation grid, to further explore relationships between the geometry, properties, and advective heat extraction.

Attenuation of dissolved metals in neutral mine drainage in the Zambian Copperbelt.

PubMed

Sracek, Ondra; Filip, Jan; Mihaljevič, Martin; Kříbek, Bohdan; Majer, Vladimír; Veselovský, František

2011-01-01

Behaviour of metals like Cu and Co was studied in nearly neutral (pH ≥ 6.4) mine drainage seepage in a stream downgradient of a tailing dam at Chambishi site in the Copperbelt of Zambia. They are attenuated by precipitation of ferruginous ochres that incorporate significant quantities of metals. Using chemical analysis, X-ray powder diffraction and Mössbauer spectroscopy, we show that the ochres are composed mostly of amorphous ferric hydroxide. Close to the seepage face, the total Fe content of ochres increases due to precipitation of amorphous ferric hydroxide, but total Fe in sediment decreases further downstream. The stream then flows through wetland (dambo) where the remaining fraction of metals is removed. During rainy periods, increased flow rate may result in re-suspension of ochres, increasing thus the mobility of metals. Major ions like sulphate are conservative at the start of the dry period (May), but gypsum may probably precipitate later at the end of the dry period. Sequential extractions of bulk sediments indicate that Mn behaves differently to Fe, with a trend of increasing Mn with distance from the tailing dam. There is much more Fe than Mn in residual (Aqua Regia) fraction, indicating that amorphous ferric hydroxides are transformed to more crystalline phases deeper in sediment. Environmental impact of mine drainage is relatively limited due to its neutral character.

Methodology of modeling and measuring computer architectures for plasma simulations

NASA Technical Reports Server (NTRS)

Wang, L. P. T.

1977-01-01

A brief introduction to plasma simulation using computers and the difficulties on currently available computers is given. Through the use of an analyzing and measuring methodology - SARA, the control flow and data flow of a particle simulation model REM2-1/2D are exemplified. After recursive refinements the total execution time may be greatly shortened and a fully parallel data flow can be obtained. From this data flow, a matched computer architecture or organization could be configured to achieve the computation bound of an application problem. A sequential type simulation model, an array/pipeline type simulation model, and a fully parallel simulation model of a code REM2-1/2D are proposed and analyzed. This methodology can be applied to other application problems which have implicitly parallel nature.

Retention and chemical speciation of uranium in an oxidized wetland sediment from the Savannah River Site.

PubMed

Li, Dien; Seaman, John C; Chang, Hyun-Shik; Jaffe, Peter R; Koster van Groos, Paul; Jiang, De-Tong; Chen, Ning; Lin, Jinru; Arthur, Zachary; Pan, Yuanming; Scheckel, Kirk G; Newville, Matthew; Lanzirotti, Antonio; Kaplan, Daniel I

2014-05-01

Uranium speciation and retention mechanisms onto Savannah River Site (SRS) wetland sediments was studied using batch (ad)sorption experiments, sequential extraction, U L3-edge X-ray absorption near-edge structure (XANES) spectroscopy, fluorescence mapping and μ-XANES. Under oxidized conditions, U was highly retained by the SRS wetland sediments. In contrast to other similar but much lower natural organic matter (NOM) sediments, significant sorption of U onto the SRS sediments was observed at pH < 4 and pH > 8. Sequential extraction indicated that the U species were primarily associated with the acid soluble fraction (weak acetic acid extractable) and organic fraction (Na-pyrophosphate extractable). Uranium L3-edge XANES spectra of the U-bound sediments were nearly identical to that of uranyl acetate. Based on fluorescence mapping, U and Fe distributions in the sediment were poorly correlated, U was distributed throughout the sample and did not appear as isolated U mineral phases. The primary oxidation state of U in these oxidized sediments was U(VI), and there was little evidence that the high sorptive capacity of the sediments could be ascribed to abiotic or biotic reduction to the less soluble U(IV) species or to secondary mineral formation. Collectively, this study suggests that U may be strongly bound to wetland sediments, not only under reducing conditions by reductive precipitation, but also under oxidizing conditions through NOM-uranium bonding. Published by Elsevier Ltd.

Assessing of distribution, mobility and bioavailability of exogenous Pb in agricultural soils using isotopic labeling method coupled with BCR approach.

PubMed

Huang, Zhi-Yong; Xie, Hong; Cao, Ying-Lan; Cai, Chao; Zhang, Zhi

2014-02-15

The contamination of Pb in agricultural soils is one of the most important ecological problems, which potentially results in serious health risk on human health through food chain. Hence, the fate of exogenous Pb contaminated in agricultural soils is needed to be deeply explored. By spiking soils with the stable enriched isotopes of (206)Pb, the contamination of exogenous Pb(2+) ions in three agricultural soils sampled from the estuary areas of Jiulong River, China was simulated in the present study, and the distribution, mobility and bioavailability of exogenous Pb in the soils were investigated using the isotopic labeling method coupled with a four-stage BCR (European Community Bureau of Reference) sequential extraction procedure. Results showed that about 60-85% of exogenous Pb was found to distribute in reducible fractions, while the exogenous Pb in acid-extractable fractions was less than 1.0%. After planting, the amounts of exogenous Pb presenting in acid-extractable, reducible and oxidizable fractions in rhizospheric soils decreased by 60-66%, in which partial exogenous Pb was assimilated by plants while most of the metal might transfer downward due to daily watering and applying fertilizer. The results show that the isotopic labeling technique coupled with sequential extraction procedures enables us to explore the distribution, mobility and bioavailability of exogenous Pb contaminated in soils, which may be useful for the further soil remediation. Copyright © 2014 Elsevier B.V. All rights reserved.

High-mobility capacitively-induced two-dimensional electrons in a lateral superlattice potential

DOE PAGES

Lu, Tzu -Ming; Laroche, Dominique; Huang, S. -H.; ...

2016-01-01

In the presence of a lateral periodic potential modulation, two-dimensional electrons may exhibit interesting phenomena, such as a graphene-like energy-momentum dispersion, Bloch oscillations, or the Hofstadter butterfly band structure. To create a sufficiently strong potential modulation using conventional semiconductor heterostructures, aggressive device processing is often required, unfortunately resulting in strong disorder that masks the sought-after effects. Here, we report a novel fabrication process flow for imposing a strong lateral potential modulation onto a capacitively induced two-dimensional electron system, while preserving the host material quality. Using this process flow, the electron density in a patterned Si/SiGe heterostructure can be tuned overmore » a wide range, from 4.4 × 10 10 cm –2 to 1.8 × 10 11 cm –2, with a peak mobility of 6.4 × 10 5 cm 2/V·s. The wide density tunability and high electron mobility allow us to observe sequential emergence of commensurability oscillations as the density, the mobility, and in turn the mean free path, increase. Magnetic-field-periodic quantum oscillations associated with various closed orbits also emerge sequentially with increasing density. We show that, from the density dependence of the quantum oscillations, one can directly extract the steepness of the imposed superlattice potential. Lastly, this result is then compared to a conventional lateral superlattice model potential.« less

On-line determination of Sb(III) and total Sb using baker's yeast immobilized on polyurethane foam and hydride generation inductively coupled plasma optical emission spectrometry

NASA Astrophysics Data System (ADS)

Menegário, Amauri A.; Silva, Ariovaldo José; Pozzi, Eloísa; Durrant, Steven F.; Abreu, Cassio H.

2006-09-01

The yeast Saccharomyces cerevisiae was immobilized in cubes of polyurethane foam and the ability of this immobilized material to separate Sb(III) and Sb(V) was investigated. A method based on sequential determination of total Sb (after on-line reduction of Sb(V) to Sb(III) with thiourea) and Sb(III) (after on-line solid-liquid phase extraction) by hydride generation inductively coupled plasma optical emission spectrometry is proposed. A flow system assembled with solenoid valves was used to manage all stages of the process. The effects of pH, sample loading and elution flow rates on solid-liquid phase extraction of Sb(III) were evaluated. Also, the parameters related to on-line pre-reduction (reaction coil and flow rates) were optimized. Detection limits of 0.8 and 0.15 μg L - 1 were obtained for total Sb and Sb(III), respectively. The proposed method was applied to the analysis of river water and effluent samples. The results obtained for the determination of total Sb were in agreement with expected values, including the river water Standard Reference Material 1640 certified by the National Institute of Standards and Technology (NIST). Recoveries of Sb(III) and Sb(V) in spiked samples were between 81 ± 19 and 111 ±15% when 120 s of sample loading were used.

Remediation of DNAPL Through Sequential In Situ Chemical Oxidation and Bioaugmentation

DTIC Science & Technology

2010-06-01

hydraulic barriers or sinks, as groundwater likely flows toward these surface water bodies and discharges into them. Other hydrologic influences at LC...intentionally. v LIST OF ACRONYMS AND ABBREVIATIONS bgs below ground surface C-C carbon-carbon CCAFB Cape Canaveral Air Force Base CO2...Program SPH six-phase heating TCE trichloroethene USEPA U.S. Environmental Protection Agency USU upper sand unit UT University of Toronto

Potential for leaching of arsenic from excavated rock after different drying treatments.

PubMed

Li, Jining; Kosugi, Tomoya; Riya, Shohei; Hashimoto, Yohey; Hou, Hong; Terada, Akihiko; Hosomi, Masaaki

2016-07-01

Leaching of arsenic (As) from excavated rock subjected to different drying methods is compared using sequential leaching tests and rapid small-scale column tests combined with a sequential extraction procedure. Although the total As content in the rock was low (8.81 mg kg(-1)), its resulting concentration in the leachate when leached at a liquid-to-solid ratio of 10 L kg(-1) exceeded the environmental standard (10 μg L(-1)). As existed mainly in dissolved forms in the leachates. All of the drying procedures applied in this study increased the leaching of As, with freeze-drying leading to the largest increase. Water extraction of As using the two tests showed different leaching behaviors as a function of the liquid-to-solid ratio, and achieved average extractions of up to 35.7% and 25.8% total As, respectively. Dissolution of As from the mineral surfaces and subsequent re-adsorption controlled the short-term release of As; dissolution of Fe, Al, and dissolved organic carbon played important roles in long-term As leaching. Results of the sequential extraction procedure showed that use of 0.05 M (NH4)2SO4 underestimates the readily soluble As. Long-term water extraction removed almost all of the non-specifically sorbed As and most of the specifically sorbed As. The concept of pollution potential indices, which are easily determined by the sequential leaching test, is proposed in this study and is considered for possible use in assessing efficacy of treatment of excavated rocks. Copyright © 2016 Elsevier Ltd. All rights reserved.

Long-Term Impacts Induced by Disposal of Contaminated River Sediments in Elliott Bay, Seattle, Washington

DTIC Science & Technology

1984-09-01

and these accompanied the sample residue through sieving to avoid sample mix- up . B. Field data sheets required logger’s initials on each page to A...ensure data completeness. C. Metal trays were placed to catch residue spillage during residue transfer from sieves to sample bottles. D. Sample bottles...methodologies were comparable for all sample e types and consisted of four sequential components: extraction, clean- up , gas chromatographic (GC) analysis, and

Preliminary results of sequential extraction experiments for selenium on mine waste and stream sediments from Vermont, Maine, and New Zealand

USGS Publications Warehouse

Piatak, N.M.; Seal, R.R.; Sanzolone, R.F.; Lamothe, P.J.; Brown, Z.A.

2006-01-01

We report the preliminary results of sequential partial dissolutions used to characterize the geochemical distribution of selenium in stream sediments, mine wastes, and flotation-mill tailings. In general, extraction schemes are designed to extract metals associated with operationally defined solid phases. Total Se concentrations and the mineralogy of the samples are also presented. Samples were obtained from the Elizabeth, Ely, and Pike Hill mines in Vermont, the Callahan mine in Maine, and the Martha mine in New Zealand. These data are presented here with minimal interpretation or discussion. Further analysis of the data will be presented elsewhere.

Scale-invariant feature extraction of neural network and renormalization group flow

NASA Astrophysics Data System (ADS)

Iso, Satoshi; Shiba, Shotaro; Yokoo, Sumito

2018-05-01

Theoretical understanding of how a deep neural network (DNN) extracts features from input images is still unclear, but it is widely believed that the extraction is performed hierarchically through a process of coarse graining. It reminds us of the basic renormalization group (RG) concept in statistical physics. In order to explore possible relations between DNN and RG, we use the restricted Boltzmann machine (RBM) applied to an Ising model and construct a flow of model parameters (in particular, temperature) generated by the RBM. We show that the unsupervised RBM trained by spin configurations at various temperatures from T =0 to T =6 generates a flow along which the temperature approaches the critical value Tc=2.2 7 . This behavior is the opposite of the typical RG flow of the Ising model. By analyzing various properties of the weight matrices of the trained RBM, we discuss why it flows towards Tc and how the RBM learns to extract features of spin configurations.

Bioactive Lipidic Extracts from Octopus (Paraoctopus limaculatus): Antimutagenicity and Antiproliferative Studies

PubMed Central

Moreno-Félix, Carolina; Wilson-Sánchez, Griselda; Cruz-Ramírez, Susana-Gabriela; Velázquez-Contreras, Carlos; Plascencia-Jatomea, Maribel; Acosta, Ana; Machi-Lara, Lorena; Aldana-Madrid, María-Lourdes; Ezquerra-Brauer, Josafat-Marina; Rocha-Alonzo, Fernando; Burgos-Hernández, Armando

2013-01-01

Fractions from an organic extract from fresh octopus (Paraoctopus limaculatus) were studied for biological activities such as antimutagenic and antiproliferative properties using Salmonella tester strains TA98 and TA100 with metabolic activation (S9) and a cancer cell line (B-cell lymphoma), respectively. A chloroform extract obtained from octopus tentacles was sequentially fractionated using thin layer chromatography (TLC), and each fraction was tested for antimutagenic and antiproliferative activities. Organic extract reduced the number of revertants caused by aflatoxin B1 showing a dose-response type of relationship. Sequential TLC fractionation of the active extracts produced several antimutagenic and/or antiproliferative fractions. Based on the results obtained, the isolated fractions obtained from octopus contain compounds with chemoprotective properties that reduce the mutagenicity of AFB1 and proliferation of cancer cell lines. PMID:23401709

Determining the speciation of Zn in soils around the sediment ponds of chemical plants by XRD and XAFS spectroscopy and sequential extraction.

PubMed

Minkina, Tatiana; Nevidomskaya, Dina; Bauer, Tatiana; Shuvaeva, Victoria; Soldatov, Alexander; Mandzhieva, Saglara; Zubavichus, Yan; Trigub, Alexander

2018-09-01

For a correct assessment of risk of polluted soil, it is crucial to establish the speciation and mobility of the contaminants. The aim of this study was to investigate the speciation and transformation of Zn in strongly technogenically transformed contaminated Spolic Technosols for a long time in territory of sludge collectors by combining analytical techniques and synchrotron techniques. Sequential fractionation of Zn compounds in studied soils revealed increasing metal mobility. Phyllosilicates and Fe and Mn hydroxides were the main stabilizers of Zn mobility. A high degree of transformation was identified for the composition of the mineral phase in Spolic Technosols by X-ray powder diffraction. Technogenic phases (Zn-containing authigenic minerals) were revealed in Spolic Technosols samples through the analysis of their Zn K-edge EXAFS and XANES spectra. In one of the samples Zn local environment was formed by predominantly oxygen atoms, and in the other one mixed ZnS and ZnO bonding was found. Zn speciation in the studied technogenically transformed soils was due to the composition of pollutants contaminating the floodplain landscapes for a long time, and, second, this is the combination of physicochemical properties controlling the buffer properties of investigated soils. X-ray spectroscopic and X-ray powder diffraction analyses combined with sequential extraction assays is an effective tool to check the affinity of the soil components for heavy metal cations. Copyright © 2018 Elsevier B.V. All rights reserved.

Multi-Level Sequential Pattern Mining Based on Prime Encoding

NASA Astrophysics Data System (ADS)

Lianglei, Sun; Yun, Li; Jiang, Yin

Encoding is not only to express the hierarchical relationship, but also to facilitate the identification of the relationship between different levels, which will directly affect the efficiency of the algorithm in the area of mining the multi-level sequential pattern. In this paper, we prove that one step of division operation can decide the parent-child relationship between different levels by using prime encoding and present PMSM algorithm and CROSS-PMSM algorithm which are based on prime encoding for mining multi-level sequential pattern and cross-level sequential pattern respectively. Experimental results show that the algorithm can effectively extract multi-level and cross-level sequential pattern from the sequence database.

40 CFR 98.423 - Calculating CO2 supply.

Code of Federal Regulations, 2010 CFR

2010-07-01

...) Calculate the annual mass of CO2 captured, extracted, imported, or exported through each flow meter in... flow meters are used, you shall calculate the annual mass of CO2 for all flow meters according to the procedures specified in paragraph (a)(3) of this section. (1) For each mass flow meter, you shall calculate...

SW-846 Test Method 3200: Mercury Species Fractionation and Quantification by Microwave Assisted Extraction, Selective Solvent Extraction and/or Solid Phase Extraction

EPA Pesticide Factsheets

a sequential extraction and separation procedure that maybe used in conjunction with a determinative method to differentiate mercury species that arepresent in soils and sediments. provides information on both total mercury andvarious mercury species.

Potential contaminants at a dredged spoil placement site, Charles City County, Virginia, as revealed by sequential extraction

PubMed Central

Tang, Jianwu; Whittecar, G Richard; Johannesson, Karen H; Daniels, W Lee

2004-01-01

Backfills of dredged sediments onto a former sand and gravel mine site in Charles City County, VA may have the potential to contaminate local groundwater. To evaluate the mobility of trace elements and to identify the potential contaminants from the dredged sediments, a sequential extraction scheme was used to partition trace elements associated with the sediments from the local aquifer and the dredged sediments into five fractions: exchangeable, acidic, reducible, oxidizable, and residual phases. Sequential extractions indicate that, for most of the trace elements examined, the residual phases account for the largest proportion of the total concentrations, and their total extractable fractions are mainly from reducible and oxidizable phases. Only Cd, Pb, and Zn have an appreciable extractable proportion from the acidic phase in the filled dredged sediments. Our groundwater monitoring data suggest that the dredged sediments are mainly subject to a decrease in pH and a series of oxidation reactions, when exposed to the atmosphere. Because the trace elements released by carbonate dissolution and the oxidation (e.g., organic matter degradation, iron sulfide and, ammonia oxidation) are subsequently immobilized by sorption to iron, manganese, and aluminum oxides, no potential contaminants to local groundwater are expected by addition of the dredged sediments to this site.

Sequential extraction of flavonoids and pectin from yellow passion fruit rind using pressurized solvent or ultrasound.

PubMed

de Souza, Caroline G; Rodrigues, Tigressa Hs; E Silva, Lorena Ma; Ribeiro, Paulo Rv; de Brito, Edy S

2018-03-01

Passion fruit rind (PFR) represents 90% of the total fruit weight and is wasted during juice processing. Passion fruit rind is known to contain flavonoids and pectin. An alternative use for this fruit juice industrial residue is to obtain these compounds. This study aimed to verify the influence of pressurized solvent extraction (PSE) or ultrasound assisted extraction (UAE) of flavonoid and pectin in a sequential process. The PSE using ethanol at 60:40 (v/v) yielded a total polyphenol content of 4.67 g GAE kg -1 PFR, orientin-7-O-glucoside (1.57 g kg -1 PFR) and luteolin-6-C-glucoside (2.44 g kg -1 PFR). Pectin yield was 165 g kg -1 PFR, either in PSE or UAE. Pectin characterization indicates that the pectic structure has basically homogalacturonans and galacturonate followed by a galacturonic acid ester unit, with methylation degree of 70%. With this study it can be concluded that mixtures of alcohols with water favor the extraction of bioactive compounds of passion fruit peel. Both PSE and UAE were effective in sequentially extracting flavonoids and pectin. The preferred solvent is ethanol due to its lower toxicity. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

Patterns and Sequences: Interactive Exploration of Clickstreams to Understand Common Visitor Paths.

PubMed

Liu, Zhicheng; Wang, Yang; Dontcheva, Mira; Hoffman, Matthew; Walker, Seth; Wilson, Alan

2017-01-01

Modern web clickstream data consists of long, high-dimensional sequences of multivariate events, making it difficult to analyze. Following the overarching principle that the visual interface should provide information about the dataset at multiple levels of granularity and allow users to easily navigate across these levels, we identify four levels of granularity in clickstream analysis: patterns, segments, sequences and events. We present an analytic pipeline consisting of three stages: pattern mining, pattern pruning and coordinated exploration between patterns and sequences. Based on this approach, we discuss properties of maximal sequential patterns, propose methods to reduce the number of patterns and describe design considerations for visualizing the extracted sequential patterns and the corresponding raw sequences. We demonstrate the viability of our approach through an analysis scenario and discuss the strengths and limitations of the methods based on user feedback.

Pumpkin (Cucurbita maxima) seed proteins: sequential extraction processing and fraction characterization.

PubMed

Rezig, Leila; Chibani, Farhat; Chouaibi, Moncef; Dalgalarrondo, Michèle; Hessini, Kamel; Guéguen, Jacques; Hamdi, Salem

2013-08-14

Seed proteins extracted from Tunisian pumpkin seeds ( Cucurbita maxima ) were investigated for their solubility properties and sequentially extracted according to the Osborne procedure. The solubility of pumpkin proteins from seed flour was greatly influenced by pH changes and ionic strength, with higher values in the alkaline pH regions. It also depends on the seed defatting solvent. Protein solubility was decreased by using chloroform/methanol (CM) for lipid extraction instead of pentane (P). On the basis of differential solubility fractionation and depending on the defatting method, the alkali extract (AE) was the major fraction (42.1 (P), 22.3% (CM)) compared to the salt extract (8.6 (P), 7.5% (CM)). In salt, alkali, and isopropanol extracts, all essential amino acids with the exceptions of threonine and lysine met the minimum requirements for preschool children (FAO/WHO/UNU). The denaturation temperatures were 96.6 and 93.4 °C for salt and alkali extracts, respectively. Pumpkin protein extracts with unique protein profiles and higher denaturation temperatures could impart novel characteristics when used as food ingredients.

WIND: Computer program for calculation of three dimensional potential compressible flow about wind turbine rotor blades

NASA Technical Reports Server (NTRS)

Dulikravich, D. S.

1980-01-01

A computer program is presented which numerically solves an exact, full potential equation (FPE) for three dimensional, steady, inviscid flow through an isolated wind turbine rotor. The program automatically generates a three dimensional, boundary conforming grid and iteratively solves the FPE while fully accounting for both the rotating cascade and Coriolis effects. The numerical techniques incorporated involve rotated, type dependent finite differencing, a finite volume method, artificial viscosity in conservative form, and a successive line overrelaxation combined with the sequential grid refinement procedure to accelerate the iterative convergence rate. Consequently, the WIND program is capable of accurately analyzing incompressible and compressible flows, including those that are locally transonic and terminated by weak shocks. The program can also be used to analyze the flow around isolated aircraft propellers and helicopter rotors in hover as long as the total relative Mach number of the oncoming flow is subsonic.

THE LIBERATION OF ARSENOSUGARS FROM MATRIX COMPONENTS IN DIFFICULT TO EXTRACT SEAFOOD SAMPLES UTILIZING TMAOH/ACETIC ACID SEQUENTIALLY IN A TWO-STAGE EXTRACTION PROCESS

EPA Science Inventory

Sample extraction is one of the most important steps in arsenic speciation analysis of solid dietary samples. One of the problem areas in this analysis is the partial extraction of arsenicals from seafood samples. The partial extraction allows the toxicity of the extracted arse...

Learning Behavior Characterization with Multi-Feature, Hierarchical Activity Sequences

ERIC Educational Resources Information Center

Ye, Cheng; Segedy, James R.; Kinnebrew, John S.; Biswas, Gautam

2015-01-01

This paper discusses Multi-Feature Hierarchical Sequential Pattern Mining, MFH-SPAM, a novel algorithm that efficiently extracts patterns from students' learning activity sequences. This algorithm extends an existing sequential pattern mining algorithm by dynamically selecting the level of specificity for hierarchically-defined features…

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bae, Wookeun; Shin, Eung Bai; Lee, Kil Chul

The potential hazard of landfill wastes was previously evaluated by examining the extraction procedures for individual waste, although various wastes were co-disposed of in actual landfills. This paper investigates the reduction of extraction-procedure toxicity by co-disposing various combinations of two wastes. When two wastes are mixed homogeneously, the extraction of heavy metals from the waste mixture is critically affected by the extract pH. Thus, co-disposal wastes will have a resultant pH between the pH values of its constituent. The lower the resultant pH, the lower the concentrations of heavy metals in the extract. When these wastes are extracted sequentially, themore » latter extracted waste has a stronger influence on the final concentration of heavy metals in the extract. Small-scale lysimeter experiments confirm that when heavy-metal-bearing leachates Generated from hazardous-waste lysimeters are passed through a nonhazardous-waste lysimeter filled with compost, briquette ash, or refuse-incineration ashes, the heavy-metal concentration in the final leachates decreases significantly. Thus, the heavy-metal leaching could be attenuated if a less extraction-procedure-toxic waste were placed at the bottom of a landfill. 3 refs., 4 figs., 5 tabs.« less

Preliminary considerations for extraction of thermal effect from magma

NASA Astrophysics Data System (ADS)

Hickox, C. E.; Dunn, J. C.

Simplified mathematical models are developed to describe the extraction of thermal energy from magma based on the concept of a counter-flow heat exchanger inserted into the magma body. Analytical solutions are used to investigate influence of the basic variables on electric power production. Calculations confirm that the proper heat exchanger flow path is down the annulus with hot fluid returning to the surface through the central core. The core must be insulated from the annulus to achieve acceptable wellhead temperatures, but this insulation thickness can be quite small. The insulation is effective in maintaining the colder annular flow below expected formation temperatures so that a net beat gain from the formation above a magma body is predicted. The analynes show that optimum flow rates exist that maximize electric power production. These optimum flow rates are functions of the heat transfer coefficients that describe magma energy extraction.

Screening antimutagenic and antiproliferative properties of extracts isolated from Jackfruit pulp (Artocarpus heterophyllus Lam).

PubMed

Ruiz-Montañez, G; Burgos-Hernández, A; Calderón-Santoyo, M; López-Saiz, C M; Velázquez-Contreras, C A; Navarro-Ocaña, A; Ragazzo-Sánchez, J A

2015-05-15

The present focused on the study of the antimutagenic and antiproliferative potential of pulp Jackfruit (Artocarpus heterophyllus Lam) extract, using Salmonella typhimurium tester strains TA98 and TA100 with metabolic activation (S9) and a cancer cell line M12.C3.F6 (murine B-cell lymphoma), respectively. Jackfruit pulp extract was sequentially fractionated by chromatography (RP-HPLC) and each fraction was tested for antimutagenic and antiproliferative activities. The organic extracts obtained from Jackfruit pulp reduced the number of revertants caused by aflatoxin B1 (AFB1) and proliferation of cells M12.C3.F6; a dose-response relationship was showed. Sequential RP-HPLC fractionation of the active extracts produced both antimutagenic and/or antiproliferative fractions. These results suggested that the Jackfruit contained compounds with chemoprotective properties to reduce the mutagenicity of AFB1, also proliferation of a cancer cell line. Copyright © 2014 Elsevier Ltd. All rights reserved.

Determination of distributions of Cd, Cu, and Pb concentrations in sediments of a Mexican reservoir to infer their environmental risk.

PubMed

Barceló-Quintal, Icela Dagmar; Solís-Correa, Hugo Eduardo; Avila-Pérez, Pedro; López-Galván, Edgar; Gómez-Salazar, Sergio; García-Albortante, Julisa

2012-07-01

The José Antonio Alzate Dam in the State of Mexico, Mexico, receives wastewaters from domestic, industrial, and agricultural activities through the Lerma River. Chemical and physicochemical characteristics of the water were determined. Sediment has been studied in order to define the importance of its influence on the reservoir's state as a whole. The quantification of the metals, Cd, Cu, and Pb in total forms and the geochemical distribution and the chemical mobility of these metals in sediment have been established using a chemical sequential extraction scheme. The three metals showed a common characteristic, being more abundant in fraction F6 (residual), but the other fractions of the geochemical distribution were variable depending on the metal. First, the contamination level was evaluated with the results of the total metals, using the criteria of EPA, Thomas and Murdoch, and the Ontario Ministry of Environment for sediment in water bodies. Subsequently, the risk was assessed using the same criteria but considering the results of sequential extractions, where the geochemical distribution of each metal allowed a better understanding of metal portions with more influence on the risk, in which Cu and Pb presented low risk, but not Cd.

Prediction of anaerobic biodegradability and bioaccessibility of municipal sludge by coupling sequential extractions with fluorescence spectroscopy: towards ADM1 variables characterization.

PubMed

Jimenez, Julie; Gonidec, Estelle; Cacho Rivero, Jesús Andrés; Latrille, Eric; Vedrenne, Fabien; Steyer, Jean-Philippe

2014-03-01

Advanced dynamic anaerobic digestion models, such as ADM1, require both detailed organic matter characterisation and intimate knowledge of the involved metabolic pathways. In the current study, a methodology for municipal sludge characterization is investigated to describe two key parameters: biodegradability and bioaccessibility of organic matter. The methodology is based on coupling sequential chemical extractions with 3D fluorescence spectroscopy. The use of increasingly strong solvents reveals different levels of organic matter accessibility and the spectroscopy measurement leads to a detailed characterisation of the organic matter. The results obtained from testing 52 municipal sludge samples (primary, secondary, digested and thermally treated) showed a successful correlation with sludge biodegradability and bioaccessibility. The two parameters, traditionally obtained through the biochemical methane potential (BMP) lab tests, are now obtain in only 5 days compared to the 30-60 days usually required. Experimental data, obtained from two different laboratory scale reactors, were used to validate the ADM1 model. The proposed approach showed a strong application potential for reactor design and advanced control of anaerobic digestion processes. Copyright © 2013 Elsevier Ltd. All rights reserved.

Molecular Characteristics of Kraft-AQ Pulping Lignin Fractionated by Sequential Organic Solvent Extraction

PubMed Central

Wang, Kun; Xu, Feng; Sun, Runcang

2010-01-01

Kraft-AQ pulping lignin was sequentially fractionated by organic solvent extractions and the molecular properties of each fraction were characterized by chemical degradation, GPC, UV, FT-IR, 13C-NMR and thermal analysis. The average molecular weight and polydispersity of each lignin fraction increased with its hydrogen-bonding capacity (Hildebrand solubility parameter). In addition, the ratio of the non-condensed guaiacyl/syringyl units and the content of β-O-4 linkages increased with the increment of the lignin fractions extracted successively with hexane, diethylether, methylene chloride, methanol, and dioxane. Furthermore, the presence of the condensation reaction products was contributed to the higher thermal stability of the larger molecules. PMID:21152286

Comparison of bioavailable vanadium in alfalfa rhizosphere soil extracted by an improved BCR procedure and EDTA, HCl, and NaNO₃ single extractions in a pot experiment with V-Cd treatments.

PubMed

Yang, Jie; Teng, Yanguo; Zuo, Rui; Song, Liuting

2015-06-01

The BCR sequential extraction procedure was compared with EDTA, HCl, and NaNO3 single extractions for evaluating vanadium bioavailability in alfalfa rhizosphere soil. The amounts of vanadium extracted by these methods were in the following order: BCR (bioavailable V) > EDTA ≈ HCl > NaNO3. Both correlation analysis and stepwise regression were adopted to illustrate the extractable vanadium between different reagents. The correlation coefficients between extracted vanadium and the vanadium contents in alfalfa roots were R NaNO3 = 0.948, R HCl = 0.902, R EDTA = 0.816, and R bioavailable V = 0.819. The stepwise multiple regression equation of the NaNO3 extraction was the most significant at a 95 % confidence interval. The influence of pH, total organic carbon, and cadmium content of soil to vanadium bioavailability were not definite. In summary, both the BCR sequential extraction and the single extraction methods were valid approaches for predicting vanadium bioavailability in alfalfa rhizosphere soil, especially the single extractions.

Arsenic release and geochemical evolution of groundwater in an alluvial aquitard, West Bengal, India.

NASA Astrophysics Data System (ADS)

Desbarats, A. J.; Pal, T.; Mukherjee, P. K.; Beckie, R. D.

2017-12-01

According to the World Health Organization, contamination of groundwater by geogenic arsenic (As) represents the largest mass poisoning in history. At a field site in West Bengal, India, the source of As affecting a shallow aquifer was traced to silty sediments filling an abandoned river meander. Along with As-bearing phases, these sediments also contain 0.46 % organic carbon. The release of As within the channel fill is investigated using a geochemical mass balance model supported by detailed field observations of aqueous chemistry, sequential extraction analyses of sediment chemistry, and analyses of sediment mineralogy. The model explores the evolution of groundwater chemistry along a flow path extending from its recharge point in an abandoned channel pond, through the channel-fill sequence, to the underlying aquifer. Variations in groundwater composition within the host sediments are explained in terms of mineral weathering driven by organic carbon decay. The model yields reaction coefficients expressing amounts of minerals (and gases) reacting or precipitating along the flow path. Arsenic and phosphorus cycles appear closely linked as these species are hosted by goethite, Fe-rich chlorite, and vivianite. Arsenic is released through the rapid reductive dissolution of goethite and the slower weathering of chlorite. Concomitantly, some As is sequestered in precipitating vivianite. These competing processes reach equilibrium deeper in the channel-fill sequence as groundwater As concentrations stabilize. Using groundwater residence time in channel fill obtained from a numerical flow model and the calculated reaction coefficients, rates of organic carbon oxidation, goethite dissolution, and net As release are estimated at 1.15 mmol C L-1 a-1, 0.18 mmol L-1 a-1, and 4.57 10-4 mmol L-1 a-1, respectively. Fine-grained yet slightly permeable deposits such as channel-fill silts containing reactive organic carbon and As-bearing goethite and phyllosilicates are localized centers of intense chemical weathering conducive to As mobilization.

Selenium speciation in phosphate mine soils and evaluation of a sequential extraction procedure using XAFS.

PubMed

Favorito, Jessica E; Luxton, Todd P; Eick, Matthew J; Grossl, Paul R

2017-10-01

Selenium is a trace element found in western US soils, where ingestion of Se-accumulating plants has resulted in livestock fatalities. Therefore, a reliable understanding of Se speciation and bioavailability is critical for effective mitigation. Sequential extraction procedures (SEP) are often employed to examine Se phases and speciation in contaminated soils but may be limited by experimental conditions. We examined the validity of a SEP using X-ray absorption spectroscopy (XAS) for both whole and a sequence of extracted soils. The sequence included removal of soluble, PO 4 -extractable, carbonate, amorphous Fe-oxide, crystalline Fe-oxide, organic, and residual Se forms. For whole soils, XANES analyses indicated Se(0) and Se(-II) predominated, with lower amounts of Se(IV) present, related to carbonates and Fe-oxides. Oxidized Se species were more elevated and residual/elemental Se was lower than previous SEP results from ICP-AES suggested. For soils from the SEP sequence, XANES results indicated only partial recovery of carbonate, Fe-oxide and organic Se. This suggests Se was incompletely removed during designated extractions, possibly due to lack of mineral solubilization or reagent specificity. Selenium fractions associated with Fe-oxides were reduced in amount or removed after using hydroxylamine HCl for most soils examined. XANES results indicate partial dissolution of solid-phases may occur during extraction processes. This study demonstrates why precautions should be taken to improve the validity of SEPs. Mineralogical and chemical characterizations should be completed prior to SEP implementation to identify extractable phases or mineral components that may influence extraction effectiveness. Sequential extraction procedures can be appropriately tailored for reliable quantification of speciation in contaminated soils. Copyright © 2017 Elsevier Ltd. All rights reserved.

Estimating Pressure Reactivity Using Noninvasive Doppler-Based Systolic Flow Index.

PubMed

Zeiler, Frederick A; Smielewski, Peter; Donnelly, Joseph; Czosnyka, Marek; Menon, David K; Ercole, Ari

2018-04-05

The study objective was to derive models that estimate the pressure reactivity index (PRx) using the noninvasive transcranial Doppler (TCD) based systolic flow index (Sx_a) and mean flow index (Mx_a), both based on mean arterial pressure, in traumatic brain injury (TBI). Using a retrospective database of 347 patients with TBI with intracranial pressure and TCD time series recordings, we derived PRx, Sx_a, and Mx_a. We first derived the autocorrelative structure of PRx based on: (A) autoregressive integrative moving average (ARIMA) modeling in representative patients, and (B) within sequential linear mixed effects (LME) models with various embedded ARIMA error structures for PRx for the entire population. Finally, we performed sequential LME models with embedded PRx ARIMA modeling to find the best model for estimating PRx using Sx_a and Mx_a. Model adequacy was assessed via normally distributed residual density. Model superiority was assessed via Akaike Information Criterion (AIC), Bayesian Information Criterion (BIC), log likelihood (LL), and analysis of variance testing between models. The most appropriate ARIMA structure for PRx in this population was (2,0,2). This was applied in sequential LME modeling. Two models were superior (employing random effects in the independent variables and intercept): (A) PRx ∼ Sx_a, and (B) PRx ∼ Sx_a + Mx_a. Correlation between observed and estimated PRx with these two models was: (A) 0.794 (p < 0.0001, 95% confidence interval (CI) = 0.788-0.799), and (B) 0.814 (p < 0.0001, 95% CI = 0.809-0.819), with acceptable agreement on Bland-Altman analysis. Through using linear mixed effects modeling and accounting for the ARIMA structure of PRx, one can estimate PRx using noninvasive TCD-based indices. We have described our first attempts at such modeling and PRx estimation, establishing the strong link between two aspects of cerebral autoregulation: measures of cerebral blood flow and those of pulsatile cerebral blood volume. Further work is required to validate.

A Centimeter-Scale Investigation of Geochemical Hotspots in a Soil Lysimeter

NASA Astrophysics Data System (ADS)

Umanzor, M.; Wang, Y.; Dontsova, K.; Chorover, J.; Troch, P. A. A.

2016-12-01

Studying the co-evolution of hydrological and biogeochemical processes in the subsurface of natural landscapes can enhance the understanding of coupled Earth-system processes. Such knowledge is imperative for improving predictions of hydro-biogeochemical cycles, especially under climate change scenarios. Hotspots may form in porous media that is undergoing biogeochemical weathering at locations where reactants accumulate to threshold values along hydrologic flow paths. This is expected to occur in weatherable silicate media, like granular basalt. To examine such processes during incipient soil formation, we constructed a sloping weighing lysimeter 2-m in length, 0.5-m in width and 1-m in depth. Mini-LEO was filled with crushed granular basalt rock with a known initial chemical composition. After 18 months of irrigation and intensive hydrological study, the model "landscape" was divided into a 3D matrix of 324 voxels and excavated. Collected samples were subjected to detailed hydro-bio-geochemical analysis to assess the formation of geochemical heterogeneity. A five-step sequential extraction was employed to characterize incongruent mineral weathering, and its relation to the spatial distribution of microbial composition (in a related study). The changes in Fe and Mn concentration and speciation along the lysimeter length and depth (as measured by each step of the sequential extraction) was quantified to characterize spatial distribution of weathering processes. Results are being used to assist in understanding not only spatial and temporal distribution of basalt weathering on the slope, but also, connections between hydrological and biogeochemical cycles that lead to formation of hotspots.

Exploring Factors of Media Characteristic Influencing Flow in Learning through Virtual Worlds

ERIC Educational Resources Information Center

Choi, Beomkyu; Baek, Youngkyun

2011-01-01

This study aims to find out factors of media characteristic which are considered to influence flow in learning through virtual worlds. One hundred ninety eight elementary students who are eleven to twelve years old participated in this study. After the exploratory factor analysis, to extract media characteristics of virtual worlds, seventy-eight…

Sequential Actions of the AAA-ATPase Valosin-containing Protein (VCP)/p97 and the Proteasome 19 S Regulatory Particle in Sterol-accelerated, Endoplasmic Reticulum (ER)-associated Degradation of 3-Hydroxy-3-methylglutaryl-coenzyme A Reductase*

PubMed Central

Morris, Lindsey L.; Hartman, Isamu Z.; Jun, Dong-Jae; Seemann, Joachim; DeBose-Boyd, Russell A.

2014-01-01

Accelerated endoplasmic reticulum (ER)-associated degradation (ERAD) of the cholesterol biosynthetic enzyme 3-hydroxy-3-methylglutaryl-coenzyme A reductase results from its sterol-induced binding to ER membrane proteins called Insig-1 and Insig-2. This binding allows for subsequent ubiquitination of reductase by Insig-associated ubiquitin ligases. Once ubiquitinated, reductase becomes dislocated from ER membranes into the cytosol for degradation by 26 S proteasomes through poorly defined reactions mediated by the AAA-ATPase valosin-containing protein (VCP)/p97 and augmented by the nonsterol isoprenoid geranylgeraniol. Here, we report that the oxysterol 25-hydroxycholesterol and geranylgeraniol combine to trigger extraction of reductase across ER membranes prior to its cytosolic release. This conclusion was drawn from studies utilizing a novel assay that measures membrane extraction of reductase by determining susceptibility of a lumenal epitope in the enzyme to in vitro protease digestion. Susceptibility of the lumenal epitope to protease digestion and thus membrane extraction of reductase were tightly regulated by 25-hydroxycholesterol and geranylgeraniol. The reaction was inhibited by RNA interference-mediated knockdown of either Insigs or VCP/p97. In contrast, reductase continued to become membrane-extracted, but not cytosolically dislocated, in cells deficient for AAA-ATPases of the proteasome 19 S regulatory particle. These findings establish sequential roles for VCP/p97 and the 19 S regulatory particle in the sterol-accelerated ERAD of reductase that may be applicable to the ERAD of other substrates. PMID:24860107

Characterization of an Isolated Kidney's Vasculature for Use in Bio-Thermal Modeling

NASA Astrophysics Data System (ADS)

Payne, Allison H.; Parker, Dennis L.; Moellmer, Jeff; Roemer, Robert B.; Clifford, Sarah

2007-05-01

Accurate bio-thermal modeling requires site-specific modeling of discrete vascular anatomy. Presented herewith are several steps that have been developed to describe the vessel network of isolated canine and bovine kidneys. These perfused, isolated kidneys provide an environment to repeatedly test and improve acquisition methods to visualize the vascular anatomy, as well as providing a method to experimentally validate discrete vasculature thermal models. The organs are preserved using a previously developed methodology that keeps the vasculature intact, allowing for the organ to be perfused. It also allows for the repeated fixation and re-hydration of the same organ, permitting the comparison of various methods and models. The organ extraction, alcohol preservation, and perfusion of the organ are described. The vessel locations were obtained through a high-resolution time-of-flight (TOF) magnetic resonance angiography (MRA) technique. Sequential improvements of both the experimental setup used for this acquisition, as well as MR sequence development are presented. The improvements in MR acquisition and experimental setup improved the number of vessels seen in both the raw data and segmented images by 50%. An automatic vessel centerline extraction algorithm describes both vessel location and genealogy. Centerline descriptions also allows for vessel diameter and flow rate determination, providing valuable input parameters for the discrete vascular thermal model. Characterized vessels networks of both canine and bovine kidneys are presented. While these tools have been developed in an ex vivo environment, all steps can be applied to in vivo applications.

Dissolution-induced preferential flow in a limestone fracture.

PubMed

Liu, Jishan; Polak, Amir; Elsworth, Derek; Grader, Avrami

2005-06-01

Flow in a rock fracture is surprisingly sensitive to the evolution of flow paths that develop as a result of dissolution. Net dissolution may either increase or decrease permeability uniformly within the fracture, or may form a preferential flow path through which most of the injected fluid flows, depending on the prevailing ambient mechanical and chemical conditions. A flow-through test was completed on an artificial fracture in limestone at room temperature under ambient confining stress of 3.5 MPa. The sample was sequentially circulated by water of two different compositions through the 1500 h duration of the experiment; the first 935 h by tap groundwater, followed by 555 h of distilled water. Measurements of differential pressures between the inlet and the outlet, fluid and dissolved mass fluxes, and concurrent X-ray CT imaging and sectioning were used to characterize the evolution of flow paths within the limestone fracture. During the initial circulation of groundwater, the differential pressure increased almost threefold, and was interpreted as a net reduction in permeability as the contacting asperities across the fracture are removed, and the fracture closes. With the circulation of distilled water, permeability initially reduces threefold, and ultimately increases by two orders of magnitude. This spontaneous switch from net decrease in permeability, to net increase occurred with no change in flow rate or applied effective stress, and is attributed to the evolving localization of flow path as evidenced by CT images. Based on the X-ray CT characterizations, a flow path-dependent flow model was developed to simulate the evolution of flow paths within the fracture and its influence on the overall flow behaviors of the injected fluid in the fracture.

Identification of myo-inositol hexakisphosphate (IP6) as a β-secretase 1 (BACE1) inhibitory molecule in rice grain extract and digest

PubMed Central

Abe, Takako K.; Taniguchi, Masayuki

2014-01-01

Alzheimer’s disease (AD) is widely considered to be caused by amyloid-β peptide (Aβ) accumulation in the brain. Aβ is excised from amyloid-β precursor protein through sequential cleavage by β-secretase 1 (BACE1) and γ-secretase. Thus, BACE1 inhibition could prevent Aβ accumulation. Here, we identified myo-inositol hexakisphosphate (IP6) as a BACE1 inhibitory molecule in rice grain extract and digest. The rice digest and IP6 significantly inhibited Aβ production in neuroblastoma cells without cytotoxicity. These results suggested that rice components, including IP6, may be promising starting materials for the development of potent and safe drugs and/or food to prevent AD. PMID:24649396

Agglomeration Multigrid for an Unstructured-Grid Flow Solver

NASA Technical Reports Server (NTRS)

Frink, Neal; Pandya, Mohagna J.

2004-01-01

An agglomeration multigrid scheme has been implemented into the sequential version of the NASA code USM3Dns, tetrahedral cell-centered finite volume Euler/Navier-Stokes flow solver. Efficiency and robustness of the multigrid-enhanced flow solver have been assessed for three configurations assuming an inviscid flow and one configuration assuming a viscous fully turbulent flow. The inviscid studies include a transonic flow over the ONERA M6 wing and a generic business jet with flow-through nacelles and a low subsonic flow over a high-lift trapezoidal wing. The viscous case includes a fully turbulent flow over the RAE 2822 rectangular wing. The multigrid solutions converged with 12%-33% of the Central Processing Unit (CPU) time required by the solutions obtained without multigrid. For all of the inviscid cases, multigrid in conjunction with an explicit time-stepping scheme performed the best with regard to the run time memory and CPU time requirements. However, for the viscous case multigrid had to be used with an implicit backward Euler time-stepping scheme that increased the run time memory requirement by 22% as compared to the run made without multigrid.

Fluidized bed desulfurization

NASA Technical Reports Server (NTRS)

Ravindram, M.; Kallvinskas, J. J. (Inventor)

1985-01-01

High sulfur content carbonaceous material, such as coal is desulfurized by continuous fluidized suspension in a reactor with chlorine gas, inert dechlorinating gas and hydrogen gas. A source of chlorine gas, a source of inert gas and a source of hydrogen gas are connected to the bottom inlet through a manifold and a heater. A flow controler operates servos in a manner to continuously and sequentially suspend coal in the three gases. The sulfur content is reduced at least 50% by the treatment.

In situ laser-induced photochemical silver substrate synthesis and sequential SERS detection in a flow cell.

PubMed

Herman, Krisztian; Szabó, László; Leopold, Loredana F; Chiş, Vasile; Leopold, Nicolae

2011-05-01

A new, simple, and effective approach for multianalyte sequential surface-enhanced Raman scattering (SERS) detection in a flow cell is reported. The silver substrate was prepared in situ by laser-induced photochemical synthesis. By focusing the laser on the 320 μm inner diameter glass capillary at 0.5 ml/min continuous flow of 1 mM silver nitrate and 10 mM sodium citrate mixture, a SERS active silver spot on the inner wall of the glass capillary was prepared in a few seconds. The test analytes, dacarbazine, 4-(2-pyridylazo)resorcinol (PAR) complex with Cu(II), and amoxicillin, were sequentially injected into the flow cell. Each analyte was adsorbed to the silver surface, enabling the recording of high intensity SERS spectra even at 2 s integration times, followed by desorption from the silver surface and being washed away from the capillary. Before and after each analyte passed the detection window, citrate background spectra were recorded, and thus, no "memory effects" perturbed the SERS detection. A good reproducibility of the SERS spectra obtained under flow conditions was observed. The laser-induced photochemically synthesized silver substrate enables high Raman enhancement, is characterized by fast preparation with a high success rate, and represents a valuable alternative for silver colloids as SERS substrate in flow approaches.

Droplet-based microfluidic washing module for magnetic particle-based assays

PubMed Central

Lee, Hun; Xu, Linfeng; Oh, Kwang W.

2014-01-01

In this paper, we propose a continuous flow droplet-based microfluidic platform for magnetic particle-based assays by employing in-droplet washing. The droplet-based washing was implemented by traversing functionalized magnetic particles across a laterally merged droplet from one side (containing sample and reagent) to the other (containing buffer) by an external magnetic field. Consequently, the magnetic particles were extracted to a parallel-synchronized train of washing buffer droplets, and unbound reagents were left in an original train of sample droplets. To realize the droplet-based washing function, the following four procedures were sequentially carried in a droplet-based microfluidic device: parallel synchronization of two trains of droplets by using a ladder-like channel network; lateral electrocoalescence by an electric field; magnetic particle manipulation by a magnetic field; and asymmetrical splitting of merged droplets. For the stable droplet synchronization and electrocoalescence, we optimized droplet generation conditions by varying the flow rate ratio (or droplet size). Image analysis was carried out to determine the fluorescent intensity of reagents before and after the washing step. As a result, the unbound reagents in sample droplets were significantly removed by more than a factor of 25 in the single washing step, while the magnetic particles were successfully extracted into washing buffer droplets. As a proof-of-principle, we demonstrate a magnetic particle-based immunoassay with streptavidin-coated magnetic particles and fluorescently labelled biotin in the proposed continuous flow droplet-based microfluidic platform. PMID:25379098

Thin, Soft, Skin-Mounted Microfluidic Networks with Capillary Bursting Valves for Chrono-Sampling of Sweat.

PubMed

Choi, Jungil; Kang, Daeshik; Han, Seungyong; Kim, Sung Bong; Rogers, John A

2017-03-01

Systems for time sequential capture of microliter volumes of sweat released from targeted regions of the skin offer the potential to enable analysis of temporal variations in electrolyte balance and biomarker concentration throughout a period of interest. Current methods that rely on absorbent pads taped to the skin do not offer the ease of use in sweat capture needed for quantitative tracking; emerging classes of electronic wearable sweat analysis systems do not directly manage sweat-induced fluid flows for sample isolation. Here, a thin, soft, "skin-like" microfluidic platform is introduced that bonds to the skin to allow for collection and storage of sweat in an interconnected set of microreservoirs. Pressure induced by the sweat glands drives flow through a network of microchannels that incorporates capillary bursting valves designed to open at different pressures, for the purpose of passively guiding sweat through the system in sequential fashion. A representative device recovers 1.8 µL volumes of sweat each from 0.8 min of sweating into a set of separate microreservoirs, collected from 0.03 cm 2 area of skin with approximately five glands, corresponding to a sweat rate of 0.60 µL min -1 per gland. Human studies demonstrate applications in the accurate chemical analysis of lactate, sodium, and potassium concentrations and their temporal variations. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Effect of Transport and Aging Processes on Metal Speciation in Iron Oxyhydroxide Aggregates, Tar Creek Superfund Site, Oklahoma

NASA Astrophysics Data System (ADS)

Estes, E. R.; Schaider, L. A.; Shine, J. P.; Brabander, D. J.

2010-12-01

Following the cessation of mining activity in the late 20th century, Tar Creek Superfund Site was left highly contaminated by Pb, Zn, and Cd. Tar Creek, which flows through the site and into the Neosho River, has been studied extensively because of its potential to transport metals from the mining site to downstream communities. Previous research identified aggregated iron oxyhydroxide material, which forms when mine seepage mixes with Tar Creek surface water, as a major transport vector of metals. Frequent flooding in Tar Creek deposits aggregates on downstream floodplains, where wetting and drying processes alter the speciation of iron and other metals. This study seeks to better quantify those changes and to determine how transport and aging affects the human and ecological health risk. Sequential extractions of aggregate samples collected from the creek demonstrate that Fe is present in both amorphous (10-35% of Fe extracted) and more crystalline (8-23% of Fe extracted) phases. Substantial portions of heavy metals sorb to amorphous iron oxyhydroxide phases (accounting for 10-30% of Pb and Zn extracted) but are not associated with more crystalline iron oxide phases (representing only 1% or less of the Pb and Zn extracted). Samples have a high organic matter content (18-25% mass loss on ignition), but only Fe was significantly extracted by the oxidizing step targeting organic matter (1-2% of Pb and Zn extracted, but 10-26% of Fe extracted). The majority of metals were extracted by the soluble or residual steps. If metals and organic matter inhibit transformation of amorphous iron oxyhydroxide material to nano and crystalline iron oxides, then a steady-state volume of amorphous iron oxyhydroxide material with a high total sorption capacity may exist within Tar Creek, enhancing the metal flux accommodated by this transport mechanism. Once transported downstream and deposited on floodplains, however, it is hypothesized that repeated changes in soil matrix composition and thermodynamic conditions could facilitate a transformation to more crystalline iron phases and increase metal bioavailability. While preliminary data from in-creek aggregates show no clear trend in mineralogical composition with downstream transport, only the furthest downstream samples have 2-line ferrihydrite in amounts detectable by XRD.

Application of Sequential Extractions and X-ray Absorption Spectroscopy to Determine the Speciation of Chromium in Northern New Jersey Marsh Soils Developed in Chromite ore Processing Residue (COPR)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Elzinga, E.; Cirmo, A

2010-01-01

The Cr speciation in marsh soils developed in weathering chromite ore processing residue (COPR) was characterized using sequential extractions and synchrotron microbeam and bulk X-ray absorption spectroscopic (XAS) analyses. The sequential extractions suggested substantial Cr associated with reducible and oxidizable soil components, and significant non-extractable residual Cr. Notable differences in Cr speciation estimates from three extraction schemes underscore the operationally defined nature of Cr speciation provided by these methods. Micro X-ray fluorescence maps and {mu}-XAS data indicated the presence of {micro}m-sized chromite particles scattered throughout the weathered COPR matrix. These particles derive from the original COPR material, and have relativelymore » high resistance towards weathering, and therefore persist even after prolonged leaching. Bulk XAS data further indicated Cr(III) incorporated in Fe(OH){sub 3}, and Cr(III) associated with organic matter. The low Cr contents of the weathered material (200-850 ppm) compared to unweathered COPR (20,000-60,000 ppm) point to substantial Cr leaching during COPR weathering, with partial repartitioning of released Cr into secondary Fe(OH){sub 3} phases and organics. The effects of anoxia on Cr speciation, and the potential of active COPR weathering releasing Cr(VI) deeper in the profile require further study.« less

Method and apparatus for measuring flow velocity using matched filters

DOEpatents

Raptis, Apostolos C.

1983-01-01

An apparatus and method for measuring the flow velocities of individual phase flow components of a multiphase flow utilizes matched filters. Signals arising from flow noise disturbance are extracted from the flow, at upstream and downstream locations. The signals are processed through pairs of matched filters which are matched to the flow disturbance frequency characteristics of the phase flow component to be measured. The processed signals are then cross-correlated to determine the transit delay time of the phase flow component between sensing positions.

Structural and functional comparison of mobile and recalcitrant humic fractions from agricultural soils

USDA-ARS?s Scientific Manuscript database

Mobile humic acid (MHA) and calcium humate (CaHA) are humic fractions sequentially extracted from soil samples. MHA is extracted by dilute NaOH, and CaHA is subsequently extracted by dilute NaOH from the dilute HCl-washed soil residues of the first extraction. This chapter reviews the recent advance...

Remediation of cadmium- and lead-contaminated agricultural soil by composite washing with chlorides and citric acid.

PubMed

Li, Yu-jiao; Hu, Peng-jie; Zhao, Jie; Dong, Chang-xun

2015-04-01

Composite washing of cadmium (Cd)- and lead (Pb)-contaminated agricultural soil from Hunan province in China using mixtures of chlorides (FeCl3, CaCl2) and citric acid (CA) was investigated. The concentrations of composite washing agents for metal removal were optimized. Sequential extraction was conducted to study the changes in metal fractions after soil washing. The removal of two metals at optimum concentration was reached. Using FeCl3 mixed with CA, 44% of Cd and 23% of Pb were removed, and 49 and 32% by CaCl2 mixed with CA, respectively. The mechanism of composite washing was postulated. A mixture of chlorides and CA enhanced metal extraction from soil through the formation of metal-chloride and metal-citrate complexes. CA in extract solutions promoted the formation of metal-chloride complexes and reduced the solution pH. Composite washing reduced Cd and Pb in Fe-Mn oxide forms significantly. Chlorides and CA exerted a synergistic effect on metal extraction during composite washing.

Direct Zinc Determination in Brazilian Sugar Cane Spirit by Solid-Phase Extraction Using Moringa oleifera Husks in a Flow System with Detection by FAAS.

PubMed

Alves, Vanessa N; Borges, Simone S O; Coelho, Nivia M M

2011-01-01

This paper reports a method for the determination of zinc in Brazilian sugar cane spirit, (cachaça in Portuguese), using solid-phase extraction with a flow injection analysis system and detection by FAAS. The sorbent material used was activated carbon obtained from Moringa oleifera husks. Flow and chemical variables of the proposed system were optimized through multivariate designs. The factors selected were sorbent mass, sample pH, sample flow rate, and eluent concentration. The optimum extraction conditions were obtained using a sample pH of 4.0, a sample flow rate of 6.0 mL min(-1), 30.0 mg of sorbent mass, and 1.0 mol L(-1) HNO(3) as the eluent at a flow rate of 4.0 mL min(-1). The limit of detection for zinc was 1.9 μg L(-1), and the precision was below 0.82% (20.0 μg L(-1), n = 7). The analytical curve was linear from 2 to 50 μg L(-1), with a correlation coefficient of 0.9996. The method developed was successfully applied to spiked Brazilian sugar cane spirit, and accuracy was assessed through recovery tests, with results ranging from 83% to 100%.

Direct Zinc Determination in Brazilian Sugar Cane Spirit by Solid-Phase Extraction Using Moringa oleifera Husks in a Flow System with Detection by FAAS

PubMed Central

Alves, Vanessa N.; Borges, Simone S. O.; Coelho, Nivia M. M.

2011-01-01

This paper reports a method for the determination of zinc in Brazilian sugar cane spirit, (cachaça in Portuguese), using solid-phase extraction with a flow injection analysis system and detection by FAAS. The sorbent material used was activated carbon obtained from Moringa oleifera husks. Flow and chemical variables of the proposed system were optimized through multivariate designs. The factors selected were sorbent mass, sample pH, sample flow rate, and eluent concentration. The optimum extraction conditions were obtained using a sample pH of 4.0, a sample flow rate of 6.0 mL min−1, 30.0 mg of sorbent mass, and 1.0 mol L−1 HNO3 as the eluent at a flow rate of 4.0 mL min−1. The limit of detection for zinc was 1.9 μg L−1, and the precision was below 0.82% (20.0 μg L−1, n = 7). The analytical curve was linear from 2 to 50 μg L−1, with a correlation coefficient of 0.9996. The method developed was successfully applied to spiked Brazilian sugar cane spirit, and accuracy was assessed through recovery tests, with results ranging from 83% to 100%. PMID:21785595

Distal end side-to-side anastomoses of sequential vein graft to small target coronary arteries improve intraoperative graft flow

PubMed Central

2014-01-01

Background End-to-side anastomoses to connect the distal end of the great saphenous vein (GSV) to small target coronary arteries are commonly performed in sequential coronary artery bypass grafting (CABG). However, the oversize diameter ratio between the GSV and small target vessels at end-to-side anastomoses might induce adverse hemodynamic condition. The purpose of this study was to describe a distal end side-to-side anastomosis technique and retrospectively compare the effect of distal end side-to-side versus end-to-side anastomosis on graft flow characteristics. Methods We performed side-to-side anastomoses to connect the distal end of the GSV to small target vessels on 30 patients undergoing off-pump sequential CABG in our hospital between October 2012 and July 2013. Among the 30 patients, end-to-side anastomoses at the distal end of the GSV were initially performed on 14 patients; however, due to poor graft flow, those anastomoses were revised into side-to-side anastomoses. We retrospectively compared the intraoperative graft flow characteristics of the end-to-side versus side-to-side anastomoses in the 14 patients. The patient outcomes were also evaluated. Results We found that the side-to-side anastomosis reconstruction improved intraoperative flow and reduced pulsatility index in all the 14 patients significantly. The 16 patients who had the distal end side-to-side anastomoses performed directly also exhibited satisfactory intraoperative graft flow. Three-month postoperative outcomes for all the patients were satisfactory. Conclusions Side-to-side anastomosis at the distal end of sequential vein grafts might be a promising strategy to connect small target coronary arteries to the GSV. PMID:24884776

Sequential fuzzy diagnosis method for motor roller bearing in variable operating conditions based on vibration analysis.

PubMed

Li, Ke; Ping, Xueliang; Wang, Huaqing; Chen, Peng; Cao, Yi

2013-06-21

A novel intelligent fault diagnosis method for motor roller bearings which operate under unsteady rotating speed and load is proposed in this paper. The pseudo Wigner-Ville distribution (PWVD) and the relative crossing information (RCI) methods are used for extracting the feature spectra from the non-stationary vibration signal measured for condition diagnosis. The RCI is used to automatically extract the feature spectrum from the time-frequency distribution of the vibration signal. The extracted feature spectrum is instantaneous, and not correlated with the rotation speed and load. By using the ant colony optimization (ACO) clustering algorithm, the synthesizing symptom parameters (SSP) for condition diagnosis are obtained. The experimental results shows that the diagnostic sensitivity of the SSP is higher than original symptom parameter (SP), and the SSP can sensitively reflect the characteristics of the feature spectrum for precise condition diagnosis. Finally, a fuzzy diagnosis method based on sequential inference and possibility theory is also proposed, by which the conditions of the machine can be identified sequentially as well.

Sequential Fuzzy Diagnosis Method for Motor Roller Bearing in Variable Operating Conditions Based on Vibration Analysis

PubMed Central

Li, Ke; Ping, Xueliang; Wang, Huaqing; Chen, Peng; Cao, Yi

2013-01-01

A novel intelligent fault diagnosis method for motor roller bearings which operate under unsteady rotating speed and load is proposed in this paper. The pseudo Wigner-Ville distribution (PWVD) and the relative crossing information (RCI) methods are used for extracting the feature spectra from the non-stationary vibration signal measured for condition diagnosis. The RCI is used to automatically extract the feature spectrum from the time-frequency distribution of the vibration signal. The extracted feature spectrum is instantaneous, and not correlated with the rotation speed and load. By using the ant colony optimization (ACO) clustering algorithm, the synthesizing symptom parameters (SSP) for condition diagnosis are obtained. The experimental results shows that the diagnostic sensitivity of the SSP is higher than original symptom parameter (SP), and the SSP can sensitively reflect the characteristics of the feature spectrum for precise condition diagnosis. Finally, a fuzzy diagnosis method based on sequential inference and possibility theory is also proposed, by which the conditions of the machine can be identified sequentially as well. PMID:23793021

Microcomputer Applications in Interaction Analysis.

ERIC Educational Resources Information Center

Wadham, Rex A.

The Timed Interval Categorical Observation Recorder (TICOR), a portable, battery powered microcomputer designed to automate the collection of sequential and simultaneous behavioral observations and their associated durations, was developed to overcome problems in gathering subtle interaction analysis data characterized by sequential flow of…

Assessing the Selectivity of Extractant Solutions for Recovering Labile Arsenic Associated with Iron (Hydr)oxides and Sulfides in Sediments

EPA Science Inventory

Sequential extractions can provide analytical constraints on the identification of mineral phases that control arsenic speciation in sediments. Model solids were used in this study to evaluate different solutions designed to extract arsenic from relatively labile solid phases. ...

Automatic retinal blood vessel parameter calculation in spectral domain optical coherence tomography

NASA Astrophysics Data System (ADS)

Wehbe, Hassan; Ruggeri, Marco; Jiao, Shuliang; Gregori, Giovanni; Puliafito, Carmen A.

2007-02-01

Measurement of retinal blood vessel parameters like the blood blow in the vessels may have significant impact on the study and diagnosis of glaucoma, a leading blinding disease worldwide. Optical coherence tomography (OCT) is a noninvasive imaging technique that can provide not only microscopic structural imaging of the retina but also functional information like the blood flow velocity in the retina. The aim of this study is to automatically extract the parameters of retinal blood vessels like the 3D orientation, the vessel diameters, as well as the corresponding absolute blood flow velocity in the vessel. The parameters were extracted from circular OCT scans around the optic disc. By removing the surface reflection through simple segmentation of the circular OCT scans a blood vessel shadowgram can be generated. The lateral coordinates and the diameter of each blood vessel are extracted from the shadowgram through a series of signal processing. Upon determination of the lateral position and the vessel diameter, the coordinate in the depth direction of each blood vessel is calculated in combination with the Doppler information for the vessel. The extraction of the vessel coordinates and diameter makes it possible to calculate the orientation of the vessel in reference to the direction of the incident sample light, which in turn can be used to calculate the absolute blood flow velocity and the flow rate.

Use of solid phase extraction (SPE) to evaluate in vitro skin permeation of aescin.

PubMed

Montenegro, L; Carbone, C; Giannone, I; Puglisi, G

2007-05-01

The aim of this work was to evaluate the feasibility of assessing aescin in vitro permeation through human skin by determining the amount of aescin permeated using conventional HPLC procedures after extraction of skin permeation samples by means of solid phase extraction (SPE). Aescin in vitro skin permeation was assessed from aqueous solutions and gels using both Franz-type diffusion cells and flow-through diffusion cells. The SPE method used was highly accurate (mean accuracy 99.66%), highly reproducible (intra-day and inter-day variations lower than 2.3% and 2.2%, respectively) and aescin recovery from normal saline was greater than 99%. The use of Franz-type diffusion cells did not allow us to determine aescin flux values through excised human skin, therefore aescin skin permeation parameters could be calculated only using flow-through diffusion cells. Plotting the cumulative amount of aescin permeated as a function of time, linear relationships were obtained from both aqueous solution and gel using flow-through diffusion cells. Aescin flux values through excised human skin from aqueous gel were significantly lower than those observed from aqueous solution (p < 0.05). Calculating aescin percutaneous absorption parameters we evidenced that aescin partition coefficient was lower from the aqueous gel with respect to the aqueous solution. Therefore, the SPE method used in this study was suitable to determine aescin in vitro skin permeation parameters from aqueous solutions and gels using a conventional HPLC method for the analysis of the skin permeation samples.

Cerebral blood flow and oxygenation in infants after birth asphyxia. Clinically useful information?

PubMed

Greisen, Gorm

2014-10-01

The term 'luxury perfusion' was coined nearly 50 years ago after observation of bright-red blood in the cerebral veins of adults with various brain pathologies. The bright-red blood represents decreased oxygen extraction and hence the perfusion is 'luxurious' compared to oxygen needs. Gradual loss of cellular energy charge during the hours following severe birth asphyxia was observed twenty years later by sequential cranial magnetic resonance spectroscopy. This led to the concept of delayed energy failure that is linked to mitochondrial dysfunction and apoptotic cell death. Abnormally increased perfusion and lack of normal cerebral blood flow regulation are also typically present, but whether the perfusion abnormalities at this secondary stage are detrimental, beneficial, or a mere epiphenomenon remains elusive. In contrast, incomplete reoxygenation of the brain during and following resuscitation is likely to compromise outcome. The clinical value of cerebral oximetry in this context can only be examined in a randomised clinical trial. Copyright © 2014 Elsevier Ltd. All rights reserved.

Real time on-chip sequential adaptive principal component analysis for data feature extraction and image compression

NASA Technical Reports Server (NTRS)

Duong, T. A.

2004-01-01

In this paper, we present a new, simple, and optimized hardware architecture sequential learning technique for adaptive Principle Component Analysis (PCA) which will help optimize the hardware implementation in VLSI and to overcome the difficulties of the traditional gradient descent in learning convergence and hardware implementation.

Flow-through dynamic microextraction system for automatic in vitro assessment of chyme bioaccessibility in food commodities.

PubMed

Souza, Lais A; Rosende, María; Korn, Maria Graças A; Miró, Manuel

2018-10-05

An automatic flow-through dynamic extraction method is proposed for the first time for in vitro exploration, with high temporal resolution, of the transit of the chyme from the gastric to the duodenal compartment using the Versantvoort's fed-state physiologically relevant extraction test. The flow manifold was coupled on-line to an inductively coupled plasma optical emission spectrometer (ICP OES) for real-time elucidation of the bioaccessible elemental fraction of micronutrients (viz., Cu, Fe and Mn) in food commodities across the gastrointestinal tract. The simulated intestinal and bile biofluid (added to the gastric phase) was successively pumped at 1.0 mL min -1 through a large-bore column (maintained at 37.0 ± 2.0 °C) initially loaded with a weighed amount of linseed (250 mg) using a PVDF filter membrane (5.0 μm pore size) for retaining of the solid sample and in-line filtration of the extracts. The lack of bias (trueness) of the on-line gastrointestinal extraction method coupled to ICP OES was confirmed using mass balance validation following microwave assisted digestion of the residual (non-bioaccessible) elemental fraction. Mass balance validation yielded absolute recoveries spanning from 79 to 121% for the overall analytes and samples. On-line dynamic extraction was critically appraised against batch counterparts for both gastric and gastrointestinal compartments. Due to the lack of consensus in the literature regarding the agitation method for batch oral bioaccessibility testing, several extraction approaches (viz., magnetic stirring, end-over-end rotation and orbital shaking) were evaluated. Improved gastric extractability of Fe along with bioaccessible data comparable to the dynamic counterpart based on the continuous displacement of the extraction equilibrium was obtained with batchwise magnetic stirring, which is deemed most appropriate for ascertaining worst-case/maximum bioaccessibility scenarios. Copyright © 2018 Elsevier B.V. All rights reserved.

[Optimization of supercritical fluid extraction of bioactive components in Ligusticum chuanxiong by orthogonal array design].

PubMed

Hu, Li-Cui; Wu, Xun; Yang, Xue-Dong

2013-10-01

With the yields of ferulic acid, coniferylferulate, Z-ligustilide, senkyunolide A, butylidenephthalide, butylphthalide, senkyunolide I, senkyunolide H, riligustilide, levistolide A, and total pharmacologically active ingredient as evaluation indexes, the extraction of Ligusticum chuanxiong by supercritical fluid technology was investigated through an orthogonal experiment L9 (3(4)). Four factors, namely temperature, pressure, flow rate of carbon dioxide, co-solvent concentration of the supercritical fluid, were investigated and optimized. Under the optimized conditions, namely 65 degrees C of temperature, 35 MPa of pressure, 1 L x min(-1) of CO2 flow rate, 8% of co-solvent concetration, supercritical fluid extraction could achieve a better yield than the conventional reflux extraction using methanol. And the supercritical fluid extraction process was validated to be stable and reliable.

Automatic flow-through dynamic extraction: A fast tool to evaluate char-based remediation of multi-element contaminated mine soils.

PubMed

Rosende, María; Beesley, Luke; Moreno-Jimenez, Eduardo; Miró, Manuel

2016-02-01

An automatic in-vitro bioaccessibility test based upon dynamic microcolumn extraction in a programmable flow setup is herein proposed as a screening tool to evaluate bio-char based remediation of mine soils contaminated with trace elements as a compelling alternative to conventional phyto-availability tests. The feasibility of the proposed system was evaluated by extracting the readily bioaccessible pools of As, Pb and Zn in two contaminated mine soils before and after the addition of two biochars (9% (w:w)) of diverse source origin (pine and olive). Bioaccessible fractions under worst-case scenarios were measured using 0.001 mol L(-1) CaCl2 as extractant for mimicking plant uptake, and analysis of the extracts by inductively coupled optical emission spectrometry. The t-test of comparison of means revealed an efficient metal (mostly Pb and Zn) immobilization by the action of olive pruning-based biochar against the bare (control) soil at the 0.05 significance level. In-vitro flow-through bioaccessibility tests are compared for the first time with in-vivo phyto-toxicity assays in a microcosm soil study. By assessing seed germination and shoot elongation of Lolium perenne in contaminated soils with and without biochar amendments the dynamic flow-based bioaccessibility data proved to be in good agreement with the phyto-availability tests. Experimental results indicate that the dynamic extraction method is a viable and economical in-vitro tool in risk assessment explorations to evaluate the feasibility of a given biochar amendment for revegetation and remediation of metal contaminated soils in a mere 10 min against 4 days in case of phyto-toxicity assays. Copyright © 2015 Elsevier B.V. All rights reserved.

Spatial confinement of active microtubule networks induces large-scale rotational cytoplasmic flow

PubMed Central

Suzuki, Kazuya; Miyazaki, Makito; Takagi, Jun; Itabashi, Takeshi; Ishiwata, Shin’ichi

2017-01-01

Collective behaviors of motile units through hydrodynamic interactions induce directed fluid flow on a larger length scale than individual units. In cells, active cytoskeletal systems composed of polar filaments and molecular motors drive fluid flow, a process known as cytoplasmic streaming. The motor-driven elongation of microtubule bundles generates turbulent-like flow in purified systems; however, it remains unclear whether and how microtubule bundles induce large-scale directed flow like the cytoplasmic streaming observed in cells. Here, we adopted Xenopus egg extracts as a model system of the cytoplasm and found that microtubule bundle elongation induces directed flow for which the length scale and timescale depend on the existence of geometrical constraints. At the lower activity of dynein, kinesins bundle and slide microtubules, organizing extensile microtubule bundles. In bulk extracts, the extensile bundles connected with each other and formed a random network, and vortex flows with a length scale comparable to the bundle length continually emerged and persisted for 1 min at multiple places. When the extracts were encapsulated in droplets, the extensile bundles pushed the droplet boundary. This pushing force initiated symmetry breaking of the randomly oriented bundle network, leading to bundles aligning into a rotating vortex structure. This vortex induced rotational cytoplasmic flows on the length scale and timescale that were 10- to 100-fold longer than the vortex flows emerging in bulk extracts. Our results suggest that microtubule systems use not only hydrodynamic interactions but also mechanical interactions to induce large-scale temporally stable cytoplasmic flow. PMID:28265076

Dynamic spatio-temporal imaging of early reflow in a neonatal rat stroke model.

PubMed

Leger, Pierre-Louis; Bonnin, Philippe; Lacombe, Pierre; Couture-Lepetit, Elisabeth; Fau, Sebastien; Renolleau, Sylvain; Gharib, Abdallah; Baud, Olivier; Charriaut-Marlangue, Christiane

2013-01-01

The aim of the study was to better understand blood-flow changes in large arteries and microvessels during the first 15 minutes of reflow in a P7 rat model of arterial occlusion. Blood-flow changes were monitored by using ultrasound imaging with sequential Doppler recordings in internal carotid arteries (ICAs) and basilar trunk. Relative cerebral blood flow (rCBF) changes were obtained by using laser speckle Doppler monitoring. Tissue perfusion was measured with [(14)C]-iodoantipyrine autoradiography. Cerebral energy metabolism was evaluated by mitochondrial oxygen consumption. Gradual increase in mean blood-flow velocities illustrated a gradual perfusion during early reflow in both ICAs. On ischemia, the middle cerebral artery (MCA) territory presented a residual perfusion, whereas the caudal territory remained normally perfused. On reflow, speckle images showed a caudorostral propagation of reperfusion through anastomotic connections, and a reduced perfusion in the MCA territory. Autoradiography highlighted the caudorostral gradient, and persistent perfusion in ventral and medial regions. These blood-flow changes were accompanied by mitochondrial respiration impairment in the ipsilateral cortex. Collectively, these data indicate the presence of a primary collateral pathway through the circle of Willis, providing an immediate diversion of blood flow toward ischemic regions, and secondary efficient cortical anastomoses in the immature rat brain.

Borehole flowmeter logging for the accurate design and analysis of tracer tests.

PubMed

Basiricò, Stefano; Crosta, Giovanni B; Frattini, Paolo; Villa, Alberto; Godio, Alberto

2015-04-01

Tracer tests often give ambiguous interpretations that may be due to the erroneous location of sampling points and/or the lack of flow rate measurements through the sampler. To obtain more reliable tracer test results, we propose a methodology that optimizes the design and analysis of tracer tests in a cross borehole mode by using vertical borehole flow rate measurements. Experiments using this approach, herein defined as the Bh-flow tracer test, have been performed by implementing three sequential steps: (1) single-hole flowmeter test, (2) cross-hole flowmeter test, and (3) tracer test. At the experimental site, core logging, pumping tests, and static water-level measurements were previously carried out to determine stratigraphy, fracture characteristics, and bulk hydraulic conductivity. Single-hole flowmeter testing makes it possible to detect the presence of vertical flows as well as inflow and outflow zones, whereas cross-hole flowmeter testing detects the presence of connections along sets of flow conduits or discontinuities intercepted by boreholes. Finally, the specific pathways and rates of groundwater flow through selected flowpaths are determined by tracer testing. We conclude that the combined use of single and cross-borehole flowmeter tests is fundamental to the formulation of the tracer test strategy and interpretation of the tracer test results. © 2014, National Ground Water Association.

Sequential Extraction Results and Mineralogy of Mine Waste and Stream Sediments Associated With Metal Mines in Vermont, Maine, and New Zealand

USGS Publications Warehouse

Piatak, N.M.; Seal, R.R.; Sanzolone, R.F.; Lamothe, P.J.; Brown, Z.A.; Adams, M.

2007-01-01

We report results from sequential extraction experiments and the quantitative mineralogy for samples of stream sediments and mine wastes collected from metal mines. Samples were from the Elizabeth, Ely Copper, and Pike Hill Copper mines in Vermont, the Callahan Mine in Maine, and the Martha Mine in New Zealand. The extraction technique targeted the following operationally defined fractions and solid-phase forms: (1) soluble, adsorbed, and exchangeable fractions; (2) carbonates; (3) organic material; (4) amorphous iron- and aluminum-hydroxides and crystalline manganese-oxides; (5) crystalline iron-oxides; (6) sulfides and selenides; and (7) residual material. For most elements, the sum of an element from all extractions steps correlated well with the original unleached concentration. Also, the quantitative mineralogy of the original material compared to that of the residues from two extraction steps gave insight into the effectiveness of reagents at dissolving targeted phases. The data are presented here with minimal interpretation or discussion and further analyses and interpretation will be presented elsewhere.

Hybrid joule heating/electro-osmosis process for extracting contaminants from soil layers

DOEpatents

Carrigan, Charles R.; Nitao, John J.

2003-06-10

Joule (ohmic) heating and electro-osmosis are combined in a hybrid process for removal of both water-soluble contaminants and non-aqueous phase liquids from contaminated, low-permeability soil formations that are saturated. Central to this hybrid process is the partial desaturation of the formation or layer using electro-osmosis to remove a portion of the pore fluids by induction of a ground water flow to extraction wells. Joule heating is then performed on a partially desaturated formation. The joule heating and electro-osmosis operations can be carried out simultaneously or sequentially if the desaturation by electro-osmosis occurs initially. Joule heating of the desaturated formation results in a very effective transfer or partitioning of liquid state contaminants to the vapor phase. The heating also substantially increases the vapor phase pressure in the porous formation. As a result, the contaminant laden vapor phase is forced out into soil layers of a higher permeability where other conventional removal processes, such as steam stripping or ground water extraction can be used to capture the contaminants. This hybrid process is more energy efficient than joule heating or steam stripping for cleaning low permeability formations and can share electrodes to minimize facility costs.

Cardiac conduction velocity estimation from sequential mapping assuming known Gaussian distribution for activation time estimation error.

PubMed

Shariat, Mohammad Hassan; Gazor, Saeed; Redfearn, Damian

2016-08-01

In this paper, we study the problem of the cardiac conduction velocity (CCV) estimation for the sequential intracardiac mapping. We assume that the intracardiac electrograms of several cardiac sites are sequentially recorded, their activation times (ATs) are extracted, and the corresponding wavefronts are specified. The locations of the mapping catheter's electrodes and the ATs of the wavefronts are used here for the CCV estimation. We assume that the extracted ATs include some estimation errors, which we model with zero-mean white Gaussian noise values with known variances. Assuming stable planar wavefront propagation, we derive the maximum likelihood CCV estimator, when the synchronization times between various recording sites are unknown. We analytically evaluate the performance of the CCV estimator and provide its mean square estimation error. Our simulation results confirm the accuracy of the proposed method and the error analysis of the proposed CCV estimator.

Antioxidant activity of extracts from the bark of Chamaecyparis lawsoniana (A. Murrary) Parl.

Treesearch

Heng Gao; Todd F. Shupe; Chung Y. Hse; Thomas L. Eberhardt

2006-01-01

The bark of Chamaecyparis lawsoniana (A. Murray) Parl. was extracted with methanol and sequentially partitioned with n-hexane, ethyl acetate, n-butanol and deionized water. The antioxidant activities of the four extracts were evaluated using the DPPH• and ABTS+• methods. The total phenolic...

Deformation behavior and mechanical analysis of vertically aligned carbon nanotube (VACNT) bundles

NASA Astrophysics Data System (ADS)

Hutchens, Shelby B.

Vertically aligned carbon nanotubes (VACNTs) serve as integral components in a variety of applications including MEMS devices, energy absorbing materials, dry adhesives, light absorbing coatings, and electron emitters, all of which require structural robustness. It is only through an understanding of VACNT's structural mechanical response and local constitutive stress-strain relationship that future advancements through rational design may take place. Even for applications in which the structural response is not central to device performance, VACNTs must be sufficiently robust and therefore knowledge of their microstructure-property relationship is essential. This thesis first describes the results of in situ uniaxial compression experiments of 50 micron diameter cylindrical bundles of these complex, hierarchical materials as they undergo unusual deformation behavior. Most notably they deform via a series of localized folding events, originating near the bundle base, which propagate laterally and collapse sequentially from bottom to top. This deformation mechanism accompanies an overall foam-like stress-strain response having elastic, plateau, and densification regimes with the addition of undulations in the stress throughout the plateau regime that correspond to the sequential folding events. Microstructural observations indicate the presence of a strength gradient, due to a gradient in both tube density and alignment along the bundle height, which is found to play a key role in both the sequential deformation process and the overall stress-strain response. Using the complicated structural response as both motivation and confirmation, a finite element model based on a viscoplastic solid is proposed. This model is characterized by a flow stress relation that contains an initial peak followed by strong softening and successive hardening. Analysis of this constitutive relation results in capture of the sequential buckling phenomenon and a strength gradient effect. This combination of experimental and modeling approaches motivates discussion of the particular microstructural mechanisms and local material behavior that govern the non-trivial energy absorption via sequential, localized buckle formation in the VACNT bundles.

Method and apparatus for measuring flow velocity using matched filters

DOEpatents

Raptis, A.C.

1983-09-06

An apparatus and method for measuring the flow velocities of individual phase flow components of a multiphase flow utilizes matched filters. Signals arising from flow noise disturbance are extracted from the flow, at upstream and downstream locations. The signals are processed through pairs of matched filters which are matched to the flow disturbance frequency characteristics of the phase flow component to be measured. The processed signals are then cross-correlated to determine the transit delay time of the phase flow component between sensing positions. 8 figs.

Understanding Human Motion Skill with Peak Timing Synergy

NASA Astrophysics Data System (ADS)

Ueno, Ken; Furukawa, Koichi

The careful observation of motion phenomena is important in understanding the skillful human motion. However, this is a difficult task due to the complexities in timing when dealing with the skilful control of anatomical structures. To investigate the dexterity of human motion, we decided to concentrate on timing with respect to motion, and we have proposed a method to extract the peak timing synergy from multivariate motion data. The peak timing synergy is defined as a frequent ordered graph with time stamps, which has nodes consisting of turning points in motion waveforms. A proposed algorithm, PRESTO automatically extracts the peak timing synergy. PRESTO comprises the following 3 processes: (1) detecting peak sequences with polygonal approximation; (2) generating peak-event sequences; and (3) finding frequent peak-event sequences using a sequential pattern mining method, generalized sequential patterns (GSP). Here, we measured right arm motion during the task of cello bowing and prepared a data set of the right shoulder and arm motion. We successfully extracted the peak timing synergy on cello bowing data set using the PRESTO algorithm, which consisted of common skills among cellists and personal skill differences. To evaluate the sequential pattern mining algorithm GSP in PRESTO, we compared the peak timing synergy by using GSP algorithm and the one by using filtering by reciprocal voting (FRV) algorithm as a non time-series method. We found that the support is 95 - 100% in GSP, while 83 - 96% in FRV and that the results by GSP are better than the one by FRV in the reproducibility of human motion. Therefore we show that sequential pattern mining approach is more effective to extract the peak timing synergy than non-time series analysis approach.

The PMHT: solutions for some of its problems

NASA Astrophysics Data System (ADS)

Wieneke, Monika; Koch, Wolfgang

2007-09-01

Tracking multiple targets in a cluttered environment is a challenging task. Probabilistic Multiple Hypothesis Tracking (PMHT) is an efficient approach for dealing with it. Essentially PMHT is based on the method of Expectation-Maximization for handling with association conflicts. Linearity in the number of targets and measurements is the main motivation for a further development and extension of this methodology. Unfortunately, compared with the Probabilistic Data Association Filter (PDAF), PMHT has not yet shown its superiority in terms of track-lost statistics. Furthermore, the problem of track extraction and deletion is apparently not yet satisfactorily solved within this framework. Four properties of PMHT are responsible for its problems in track maintenance: Non-Adaptivity, Hospitality, Narcissism and Local Maxima. 1, 2 In this work we present a solution for each of them and derive an improved PMHT by integrating the solutions into the PMHT formalism. The new PMHT is evaluated by Monte-Carlo simulations. A sequential Likelihood-Ratio (LR) test for track extraction has been developed and already integrated into the framework of traditional Bayesian Multiple Hypothesis Tracking. 3 As a multi-scan approach, also the PMHT methodology has the potential for track extraction. In this paper an analogous integration of a sequential LR test into the PMHT framework is proposed. We present an LR formula for track extraction and deletion using the PMHT update formulae. As PMHT provides all required ingredients for a sequential LR calculation, the LR is thus a by-product of the PMHT iteration process. Therefore the resulting update formula for the sequential LR test affords the development of Track-Before-Detect algorithms for PMHT. The approach is illustrated by a simple example.

A Computational Model of Coupled Multiphase Flow and Geomechanics to Study Fault Slip and Induced Seismicity

NASA Astrophysics Data System (ADS)

Juanes, R.; Jha, B.

2014-12-01

The coupling between subsurface flow and geomechanical deformation is critical in the assessment of the environmental impacts of groundwater use, underground liquid waste disposal, geologic storage of carbon dioxide, and exploitation of shale gas reserves. In particular, seismicity induced by fluid injection and withdrawal has emerged as a central element of the scientific discussion around subsurface technologies that tap into water and energy resources. Here we present a new computational approach to model coupled multiphase flow and geomechanics of faulted reservoirs. We represent faults as surfaces embedded in a three-dimensional medium by using zero-thickness interface elements to accurately model fault slip under dynamically evolving fluid pressure and fault strength. We incorporate the effect of fluid pressures from multiphase flow in the mechanical stability of faults and employ a rigorous formulation of nonlinear multiphase geomechanics that is capable of handling strong capillary effects. We develop a numerical simulation tool by coupling a multiphase flow simulator with a mechanics simulator, using the unconditionally stable fixed-stress scheme for the sequential solution of two-way coupling between flow and geomechanics. We validate our modeling approach using several synthetic, but realistic, test cases that illustrate the onset and evolution of earthquakes from fluid injection and withdrawal. We also present the application of the coupled flow-geomechanics simulation technology to the post mortem analysis of the Mw=5.1, May 2011 Lorca earthquake in south-east Spain, and assess the potential that the earthquake was induced by groundwater extraction.

Sequential extraction of metals from mixed and digested sludge from aerobic WWTPs sited in the south of Spain

DOE Office of Scientific and Technical Information (OSTI.GOV)

Alonso, E.; Aparicio, I.; Santos, J.L.

2009-01-15

The content of heavy metals is the major limitation to the application of sewage sludge in soil. However, assessment of the pollution by total metal determination does not reveal the true environmental impact. It is necessary to apply sequential extraction techniques to obtain suitable information about their bioavailability or toxicity. In this paper, sequential extraction of metals from sludge before and after aerobic digestion was applied to sludge from five WWTPs in southern Spain to obtain information about the influence of the digestion treatment in the concentration of the metals. The percentage of each metal as residual, oxidizable, reducible andmore » exchangeable form was calculated. For this purpose, sludge samples were collected from two different points of the plants, namely, sludge from the mixture (primary and secondary sludge) tank (mixed sludge, MS) and the digested-dewatered sludge (final sludge, FS). Heavy metals, Al, Cd, Co, Cr, Cu, Fe, Hg, Mn, Mo, Ni, Pb, Ti and Zn, were extracted following the sequential extraction scheme proposed by the Standards, Measurements and Testing Programme of the European Commission and determined by inductively-coupled plasma atomic emission spectrometry. The total concentration of heavy metals in the measured sludge samples did not exceed the limits set out by European legislation and were mainly associated with the two less-available fractions (27-28% as oxidizable metal and 44-50% as residual metal). However, metals as Co (64% in MS and 52% in FS samples), Mn (82% in MS and 79% in FS), Ni (32% in MS and 26% in FS) and Zn (79% in MS and 62% in FS) were present at important percentages as available forms. In addition, results showed a clear increase of the concentration of metals after sludge treatment in the proportion of two less-available fractions (oxidizable and residual metal)« less

Sequential extraction of metals from mixed and digested sludge from aerobic WWTPs sited in the south of Spain.

PubMed

Alonso, E; Aparicio, I; Santos, J L; Villar, P; Santos, A

2009-01-01

The content of heavy metals is the major limitation to the application of sewage sludge in soil. However, assessment of the pollution by total metal determination does not reveal the true environmental impact. It is necessary to apply sequential extraction techniques to obtain suitable information about their bioavailability or toxicity. In this paper, sequential extraction of metals from sludge before and after aerobic digestion was applied to sludge from five WWTPs in southern Spain to obtain information about the influence of the digestion treatment in the concentration of the metals. The percentage of each metal as residual, oxidizable, reducible and exchangeable form was calculated. For this purpose, sludge samples were collected from two different points of the plants, namely, sludge from the mixture (primary and secondary sludge) tank (mixed sludge, MS) and the digested-dewatered sludge (final sludge, FS). Heavy metals, Al, Cd, Co, Cr, Cu, Fe, Hg, Mn, Mo, Ni, Pb, Ti and Zn, were extracted following the sequential extraction scheme proposed by the Standards, Measurements and Testing Programme of the European Commission and determined by inductively-coupled plasma atomic emission spectrometry. The total concentration of heavy metals in the measured sludge samples did not exceed the limits set out by European legislation and were mainly associated with the two less-available fractions (27-28% as oxidizable metal and 44-50% as residual metal). However, metals as Co (64% in MS and 52% in FS samples), Mn (82% in MS and 79% in FS), Ni (32% in MS and 26% in FS) and Zn (79% in MS and 62% in FS) were present at important percentages as available forms. In addition, results showed a clear increase of the concentration of metals after sludge treatment in the proportion of two less-available fractions (oxidizable and residual metal).

Common sense reasoning about petroleum flow

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rosenberg, S.

1981-02-01

This paper describes an expert system for understanding and Reasoning in a petroleum resources domain. A basic model is implemented in FRL (Frame Representation Language). Expertise is encoded as rule frames. The model consists of a set of episodic contexts which are sequentially generated over time. Reasoning occurs in separate reasoning contexts consisting of a buffer frame and packets of rules. These function similar to small production systems. reasoning is linked to the model through an interface of Sentinels (instance driven demons) which notice anomalous conditions. Heuristics and metaknowledge are used through the creation of further reasoning contexts which overlaymore » the simpler ones.« less

Experimental investigation of turbulent flow through a circular-to-rectangular transition duct. Ph.D. Thesis - Washington Univ.

NASA Technical Reports Server (NTRS)

Davis, David O.

1991-01-01

Steady, incompressible, turbulent, swirl-free flow through a circular-to-rectangular transition duck was studied experimentally. The cross-sectional area remains the same at the exit as at the inlet, but varies through the transition section to a maximum value approximately 15 percent above the inlet value. The cross-sectional geometry everywhere along the duct is defined by the equation of a superellipse. Mean and turbulence data were accumulated utilizing pressure and hot-wire instrumentation at five stations along the test section. Data are presented for operating bulk Reynolds numbers of 88,000 and 390,000. Measured quantities include total and static pressure, the three components of the mean velocity vector, and the six components of the Reynolds stress tensor. In addition to the transition duct measurements, a hot-wire technique which relies on the sequential use of single rotatable normal and slant-wire probes was proposed. The technique is applicable for measurement of the total mean velocity vector and the complete Reynolds stress tensor when the primary flow is arbitrarily skewed relative to a plane which lies normal to the probe axis of rotation.

Assessment of elemental mobility in soil using a fluidised bed approach with on-line ICP-MS analysis.

PubMed

Beeston, Michael Philip; Glass, Hylke Jan; van Elteren, Johannes Teun; Slejkovec, Zdenka

2007-09-19

A new method has been developed to analyse the mobility of elements within soils employing counter-current flow soil contacting in a fluidised bed (FB) column. This method alleviates the problem of irreproducible peaks suffered by state-of-the-art micro-column techniques as a result of particle compaction. Reproducible extraction profiles are produced through the leaching of soil with a linear gradient of 0.05 mol L(-1) ammonium sulphate to 0.11 mol L(-1) acetic acid using a high pressure liquid chromatography (HPLC) quaternary pump, and the continuous monitoring of the elements in the leachate with inductively coupled plasma mass spectrometry (ICP-MS). Quantification of the procedure is achieved with an external flow injection (FI) calibration method. Flow rate and FB column length were investigated as critical parameters to the efficiency of the extraction methodology. It was found that an increase in the column length from 10 to 20 cm using a flow rate of 0.15 mL min(-1) produced the same increase in extracted elemental concentration as an increase in flow rate from 0.15 to 0.30 mL min(-1). In both examples, the increase in the concentration of elements leached from the soil may be ascribed to the increase in the concentration gradient between the solid and liquid. The exhaustive nature of the technique defines the maximum leachable concentration within the operationally defined leaching parameters of the exchangeable phase, providing a more accurate assessment of the risk associated with the elements in the soil for the phase providing the greatest risk to the environment. The multi-elemental high sensitivity nature of the on-line detector provides an accurate determination of the associations present between the elements in the soil, and the identification of multiple phases within the exchangeable phase through the presence of multiple peaks in the extraction profiles. It is possible through the deconvolution of these extraction profiles that the concentration corresponding to the peaks identified can be defined.

Finding False Paths in Sequential Circuits

NASA Astrophysics Data System (ADS)

Matrosova, A. Yu.; Andreeva, V. V.; Chernyshov, S. V.; Rozhkova, S. V.; Kudin, D. V.

2018-02-01

Method of finding false paths in sequential circuits is developed. In contrast with heuristic approaches currently used abroad, the precise method based on applying operations on Reduced Ordered Binary Decision Diagrams (ROBDDs) extracted from the combinational part of a sequential controlling logic circuit is suggested. The method allows finding false paths when transfer sequence length is not more than the given value and obviates the necessity of investigation of combinational circuit equivalents of the given lengths. The possibilities of using of the developed method for more complicated circuits are discussed.

Environmental continuous air monitor inlet with combined preseparator and virtual impactor

DOEpatents

Rodgers, John C [Santa Fe, NM

2007-06-19

An inlet for an environmental air monitor is described wherein a pre-separator interfaces with ambient environment air and removes debris and insects commonly associated with high wind outdoors and a deflector plate in communication with incoming air from the pre-separator stage, that directs the air radially and downward uniformly into a plurality of accelerator jets located in a manifold of a virtual impactor, the manifold being cylindrical and having a top, a base, and a wall, with the plurality of accelerator jets being located in the top of the manifold and receiving the directed air and accelerating directed air, thereby creating jets of air penetrating into the manifold, where a major flow is deflected to the walls of the manifold and extracted through ports in the walls. A plurality of receiver nozzles are located in the base of the manifold coaxial with the accelerator jets, and a plurality of matching flow restrictor elements are located in the plurality of receiver nozzles for balancing and equalizing the total minor flow among all the plurality of receiver nozzles, through which a lower, fractional flow extracts large particle constituents of the air for collection on a sample filter after passing through the plurality of receiver nozzles and the plurality of matching flow restrictor elements.

Sequential patterns of essential trace elements composition in Gracilaria verrucosa and its generated products

NASA Astrophysics Data System (ADS)

Izzati, Munifatul; Haryanti, Sri; Parman, Sarjana

2018-05-01

Gracilaria widely known as a source of essential trace elements. However this red seaweeds also has great potential for being developed into commercial products. This study examined the sequential pattern of essential trace elements composition in fresh Gracilaria verrucosa and a selection of its generated products, nemely extracted agar, Gracilaria salt and Gracilaria residue. The sample was collected from a brackish water pond, located in north part Semarang, Central Java. The collected sample was then dried under the sun, and subsequently processed into aformentioned generated products. The Gracilaria salt was obtain by soaking the sun dried Gracilaria overnight in fresh water overnight. The resulted salt solution was then boiled leaving crystal salt. Extracted agar was obtained with alkali agar extraction method. The rest of remaining material was considered as Gracilaria residue. The entire process was repeated 3 times. The compositin of trace elements was examined using ICP-MS Spectrometry. Collected data was then analyzed by ANOVA single factor. Resulting sequential pattern of its essential trace elements composition was compared. A regular table salt was used as controls. Resuts from this study revealed that Gracilaria verrucosa and its all generated products all have similarly patterned the composition of essential trace elements, where Mn>Zn>Cu>Mo. Additionally this pattern is similar to different subspecies of Gracilaria from different location and and different season. However, Gracilaria salt has distinctly different pattern of sequential essential trace elements composition compared to table salt.

Automated Desalting Apparatus

NASA Technical Reports Server (NTRS)

Spencer, Maegan K.; Liu, De-Ling; Kanik, Isik; Beegle, Luther

2010-01-01

Because salt and metals can mask the signature of a variety of organic molecules (like amino acids) in any given sample, an automated system to purify complex field samples has been created for the analytical techniques of electrospray ionization/ mass spectroscopy (ESI/MS), capillary electrophoresis (CE), and biological assays where unique identification requires at least some processing of complex samples. This development allows for automated sample preparation in the laboratory and analysis of complex samples in the field with multiple types of analytical instruments. Rather than using tedious, exacting protocols for desalting samples by hand, this innovation, called the Automated Sample Processing System (ASPS), takes analytes that have been extracted through high-temperature solvent extraction and introduces them into the desalting column. After 20 minutes, the eluent is produced. This clear liquid can then be directly analyzed by the techniques listed above. The current apparatus including the computer and power supplies is sturdy, has an approximate mass of 10 kg, and a volume of about 20 20 20 cm, and is undergoing further miniaturization. This system currently targets amino acids. For these molecules, a slurry of 1 g cation exchange resin in deionized water is packed into a column of the apparatus. Initial generation of the resin is done by flowing sequentially 2.3 bed volumes of 2N NaOH and 2N HCl (1 mL each) to rinse the resin, followed by .5 mL of deionized water. This makes the pH of the resin near neutral, and eliminates cross sample contamination. Afterward, 2.3 mL of extracted sample is then loaded into the column onto the top of the resin bed. Because the column is packed tightly, the sample can be applied without disturbing the resin bed. This is a vital step needed to ensure that the analytes adhere to the resin. After the sample is drained, oxalic acid (1 mL, pH 1.6-1.8, adjusted with NH4OH) is pumped into the column. Oxalic acid works as a chelating reagent to bring out metal ions, such as calcium and iron, which would otherwise interfere with amino acid analysis. After oxalic acid, 1 mL 0.01 N HCl and 1 mL deionized water is used to sequentially rinse the resin. Finally, the amino acids attached to the resin, and the analytes are eluted using 2.5 M NH4OH (1 mL), and the NH4OH eluent is collected in a vial for analysis.

Potatoes and Trout: Maintaining Robust Agriculture and a Healthy Trout Fishery in the Central Sands of Wisconsin

NASA Astrophysics Data System (ADS)

Fienen, M. N.; Bradbury, K. R.; Kniffin, M.; Barlow, P. M.; Krause, J.; Westenbroek, S.; Leaf, A.

2015-12-01

The well-drained sandy soil in the Wisconsin Central Sands is ideal for growing potatoes, corn, and other vegetables. A shallow sand and gravel aquifer provides abundant water for agricultural irrigation but also supplies critical base flow to cold-water trout streams. These needs compete with one another, and stakeholders from various perspectives are collaborating to seek solutions. Stakeholders were engaged in providing and verifying data to guide construction of a groundwater flow model which was used with linear and sequential linear programming to evaluate optimal tradeoffs between agricultural pumping and ecologically based minimum base flow values. The connection between individual irrigation wells as well as industrial and municipal supply and streamflow depletion can be evaluated using the model. Rather than addressing 1000s of wells individually, a variety of well management groups were established through k-means clustering. These groups are based on location, potential impact, water-use categories, depletion potential, and other factors. Through optimization, pumping rates were reduced to attain mandated minimum base flows. This formalization enables exploration of possible solutions for the stakeholders, and provides a tool which is transparent and forms a basis for discussion and negotiation.

3D-printed lab-on-valve for fluorescent determination of cadmium and lead in water.

PubMed

Mattio, Elodie; Robert-Peillard, Fabien; Vassalo, Laurent; Branger, Catherine; Margaillan, André; Brach-Papa, Christophe; Knoery, Joël; Boudenne, Jean-Luc; Coulomb, Bruno

2018-06-01

In recent years, the development of 3D printing in flow analysis has allowed the creation of new systems with various applications. Up to now, 3D printing was mainly used for the manufacture of small units such as flow detection cells, preconcentration units or mixing systems. In the present study, a new 3D printed lab-on-valve system was developed to selectively quantify lead and cadmium in water. Different technologies were compared for lab-on-valve 3D printing. Printed test units have shown that stereolithography or digital light processing are satisfactory techniques for creating complex lab-on-valve units. The lab-on-valve system was composed of two columns, eight peripheral ports and a central port, and a coil integrating baffles to increase mixing possibilities. A selective extraction of lead was first carried out by TrisKem Pb™ Resin column. Then, cadmium not retained on the first column was extracted on a second column of Amberlite® IR 120 resin. In a following step, lead and cadmium were eluted with ammonium oxalate and potassium iodide, respectively. Finally, the two metals were sequentially detected by the same Rhod-5N™ fluorescent reagent. This 3D printed lab-on-valve flow system allowed us to quantify lead and cadmium with a linear response from 0.2 to 15 µg L -1 and detection limits of 0.17 and 0.20 µg L -1 for lead and cadmium, respectively, which seems adapted for natural water analysis. Copyright © 2018 Elsevier B.V. All rights reserved.

Robust, non-invasive methods for metering groundwater well extraction in remote environments

NASA Astrophysics Data System (ADS)

Bulovic, Nevenka; Keir, Greg; McIntyre, Neil

2017-04-01

Quantifying the rate of extraction from groundwater wells can be essential for regional scale groundwater management and impact assessment. This is especially the case in regions heavily dependent on groundwater such as the semi-arid Surat and Bowen Basins in Queensland, Australia. Of the 30 000+ groundwater wells in this area, the majority of which are used for stock watering and domestic purposes, almost none have flow metering devices installed. As part of a research project to estimate regional groundwater extraction, we have undertaken a small scale flow metering program on a selected set of wells. Conventional in-line flow meters were unsuitable for our project, as both non-invasiveness and adaptability / suitability to a variety of discharge pipe characteristics was critical. We describe the use of two metering technologies not widely used in groundwater applications, non-invasive, clamp-on ultrasonic transit time flow meters and tipping bucket flow meters, as semi-permanent installations on discharge pipes of various artesian and sub-artesian groundwater wells. We present examples of detailed extraction rate time-series, which are of particular value in developing predictive models of water well extraction in data limited areas where water use dynamics and drivers are poorly understood. We conclude by discussing future project trajectories, which include expansion of the monitoring network through development of novel metering techniques and telemetry across large areas of poor connectivity.

Fractionation and characterization of semi polar and polar compounds from leaf extract Nicotiana tabaccum L. reflux ethanol extraction results

NASA Astrophysics Data System (ADS)

Rahardjo, Andhika Priotomo; Fauzantoro, Ahmad; Gozan, Misri

2018-02-01

The decline in cigarette production as the solution of health problems can interfere with the welfare of tobacco farmers in Indonesia. So, it is required to utilize the alternative uses of tobacco with chemical compounds inside it as the raw material for producing alternative products. One of the methods that is efficient in separating chemical compounds from plant extracts is fractionation and characterization method. This method has never been used for Nicotiana tabaccum L. extract using semi polar and polar solvents. This study begins with preparing Nicotiana tabaccum L. extract ingredients obtained through reflux ethanol extraction process. Extracts are analyzed by HPLC which serves to determine the chemical compounds in tobacco extract qualitatively. Extract that has been analyzed, is then fractionated using column chromatography with semi polar (ethyl acetate) and polar (ethane) solvents sequentially. Chemical compounds from tobacco extracts will be dissolved in accordance with the polarity of each solvents. The chemical compound is then characterized using HPLC quantitatively and qualitatively. Then, the data that has been obtained is used to find the partition coefficient of the main components in Nicotiana tabaccum L., which is Nicotine (kN) in Virginia 1 (Ethyl Acetate) fraction at 0.075; Virginia 2 (Ethyl Acetate) fraction at 0.037; And Virginia 3 (Ethyl Acetate) fraction at 0.043.

Antioxidant activity of Coriandrum sativum and protection against DNA damage and cancer cell migration.

PubMed

Tang, Esther L H; Rajarajeswaran, Jayakumar; Fung, Shin Yee; Kanthimathi, M S

2013-12-09

Coriandrum sativum is a popular culinary and medicinal herb of the Apiaceae family. Health promoting properties of this herb have been reported in pharmacognostical, phytochemical and pharmacological studies. However, studies on C. sativum have always focused on the aerial parts of the herb and scientific investigation on the root is limited. The aim of this research was to investigate the antioxidant and anticancer activities of C. sativum root, leaf and stem, including its effect on cancer cell migration, and its protection against DNA damage, with special focus on the roots. Powdered roots, leaves and stems of C. sativum were extracted through sequential extraction using hexane, dichloromethane, ethyl acetate, methanol and water. Total phenolic content, FRAP and DPPH radical scavenging activities were measured. Anti-proliferative activitiy on the breast cancer cell line, MCF-7, was assayed using the MTT assay. Activities of the antioxidant enzymes, catalase, superoxide dismutase, glutathione peroxidase, and of the caspases-3, -8 and -9 were assayed on treatment with the extract. Cell cycle progression was analysed using flow cytometry. The scratch motility assay was used to assess inhibition of MCF-7 cell migration. DNA damage in 3 T3-L1 fibroblasts was evaluated by the comet assay. The components in the extract were identified by HPLC and GC-MS. The ethyl acetate extract of C. sativum roots showed the highest antiproliferative activity on MCF-7 cells (IC50 = 200.0 ± 2.6 μg/mL) and had the highest phenolic content, FRAP and DPPH scavenging activities among the extracts. C. sativum root inhibited DNA damage and prevented MCF-7 cell migration induced by H2O2, suggesting its potential in cancer prevention and inhibition of metastasis. The extract exhibited anticancer activity in MCF-7 cells by affecting antioxidant enzymes possibly leading to H2O2 accumulation, cell cycle arrest at the G2/M phase and apoptotic cell death by the death receptor and mitochondrial apoptotic pathways. This study is the first report on the antioxidant and anticancer properties of C. sativum root. The herb shows potential in preventing oxidative stress-related diseases and would be useful as supplements used in combination with conventional drugs to enhance the treatment of diseases such as cancer.

Antioxidant activity of Coriandrum sativum and protection against DNA damage and cancer cell migration

PubMed Central

2013-01-01

Background Coriandrum sativum is a popular culinary and medicinal herb of the Apiaceae family. Health promoting properties of this herb have been reported in pharmacognostical, phytochemical and pharmacological studies. However, studies on C. sativum have always focused on the aerial parts of the herb and scientific investigation on the root is limited. The aim of this research was to investigate the antioxidant and anticancer activities of C. sativum root, leaf and stem, including its effect on cancer cell migration, and its protection against DNA damage, with special focus on the roots. Methods Powdered roots, leaves and stems of C. sativum were extracted through sequential extraction using hexane, dichloromethane, ethyl acetate, methanol and water. Total phenolic content, FRAP and DPPH radical scavenging activities were measured. Anti-proliferative activitiy on the breast cancer cell line, MCF-7, was assayed using the MTT assay. Activities of the antioxidant enzymes, catalase, superoxide dismutase, glutathione peroxidase, and of the caspases-3, -8 and -9 were assayed on treatment with the extract. Cell cycle progression was analysed using flow cytometry. The scratch motility assay was used to assess inhibition of MCF-7 cell migration. DNA damage in 3 T3-L1 fibroblasts was evaluated by the comet assay. The components in the extract were identified by HPLC and GC-MS. Results The ethyl acetate extract of C. sativum roots showed the highest antiproliferative activity on MCF-7 cells (IC50 = 200.0 ± 2.6 μg/mL) and had the highest phenolic content, FRAP and DPPH scavenging activities among the extracts. C. sativum root inhibited DNA damage and prevented MCF-7 cell migration induced by H2O2, suggesting its potential in cancer prevention and inhibition of metastasis. The extract exhibited anticancer activity in MCF-7 cells by affecting antioxidant enzymes possibly leading to H2O2 accumulation, cell cycle arrest at the G2/M phase and apoptotic cell death by the death receptor and mitochondrial apoptotic pathways. Conclusions This study is the first report on the antioxidant and anticancer properties of C. sativum root. The herb shows potential in preventing oxidative stress-related diseases and would be useful as supplements used in combination with conventional drugs to enhance the treatment of diseases such as cancer. PMID:24517259

The RiverFish Approach to Business Process Modeling: Linking Business Steps to Control-Flow Patterns

NASA Astrophysics Data System (ADS)

Zuliane, Devanir; Oikawa, Marcio K.; Malkowski, Simon; Alcazar, José Perez; Ferreira, João Eduardo

Despite the recent advances in the area of Business Process Management (BPM), today’s business processes have largely been implemented without clearly defined conceptual modeling. This results in growing difficulties for identification, maintenance, and reuse of rules, processes, and control-flow patterns. To mitigate these problems in future implementations, we propose a new approach to business process modeling using conceptual schemas, which represent hierarchies of concepts for rules and processes shared among collaborating information systems. This methodology bridges the gap between conceptual model description and identification of actual control-flow patterns for workflow implementation. We identify modeling guidelines that are characterized by clear phase separation, step-by-step execution, and process building through diagrams and tables. The separation of business process modeling in seven mutually exclusive phases clearly delimits information technology from business expertise. The sequential execution of these phases leads to the step-by-step creation of complex control-flow graphs. The process model is refined through intuitive table and diagram generation in each phase. Not only does the rigorous application of our modeling framework minimize the impact of rule and process changes, but it also facilitates the identification and maintenance of control-flow patterns in BPM-based information system architectures.

Sequential injection analysis with chemiluminescence detection for rapid monitoring of commercial Calendula officinalis extractions.

PubMed

Hughes, Rachel R; Scown, David; Lenehan, Claire E

2015-01-01

Plant extracts containing high levels of antioxidants are desirable due to their reported health benefits. Most techniques capable of determining the antioxidant activity of plant extracts are unsuitable for rapid at-line analysis as they require extensive sample preparation and/or long analysis times. Therefore, analytical techniques capable of real-time or pseudo real-time at-line monitoring of plant extractions, and determination of extraction endpoints, would be useful to manufacturers of antioxidant-rich plant extracts. To develop a reliable method for the rapid at-line extraction monitoring of antioxidants in plant extracts. Calendula officinalis extracts were prepared from dried flowers and analysed for antioxidant activity using sequential injection analysis (SIA) with chemiluminescence (CL) detection. The intensity of CL emission from the reaction of acidic potassium permanganate with antioxidants within the extract was used as the analytical signal. The SIA-CL method was applied to monitor the extraction of C. officinalis over the course of a batch extraction to determine the extraction endpoint. Results were compared with those from ultra high performance liquid chromatography (UHPLC). Pseudo real-time, at-line monitoring showed the level of antioxidants in a batch extract of Calendula officinalis plateaued after 100 min of extraction. These results correlated well with those of an offline UHPLC study. SIA-CL was found to be a suitable method for pseudo real-time monitoring of plant extractions and determination of extraction endpoints with respect to antioxidant concentrations. The method was applied at-line in the manufacturing industry. Copyright © 2015 John Wiley & Sons, Ltd.

Materials in the economy; material flows, scarcity, and the environment

USGS Publications Warehouse

Wagner, Lorie A.

2002-01-01

The importance of materials to the economy of the United States is described, including the levels of consumption and uses of materials. The paths (or flows) that materials take from extraction, through processing, to consumer products, and then final disposition are illustrated. Scarcity and environmental issues as they relate to the flow of materials are discussed. Examples for the three main themes of the report (material flows, scarcity, and the environment) are presented.

Mantle-circulation models with sequential data assimilation: inferring present-day mantle structure from plate-motion histories.

PubMed

Bunge, Hans-Peter; Richards, M A; Baumgardner, J R

2002-11-15

Data assimilation is an approach to studying geodynamic models consistent simultaneously with observables and the governing equations of mantle flow. Such an approach is essential in mantle circulation models, where we seek to constrain an unknown initial condition some time in the past, and thus cannot hope to use first-principles convection calculations to infer the flow history of the mantle. One of the most important observables for mantle-flow history comes from models of Mesozoic and Cenozoic plate motion that provide constraints not only on the surface velocity of the mantle but also on the evolution of internal mantle-buoyancy forces due to subducted oceanic slabs. Here we present five mantle circulation models with an assimilated plate-motion history spanning the past 120 Myr, a time period for which reliable plate-motion reconstructions are available. All models agree well with upper- and mid-mantle heterogeneity imaged by seismic tomography. A simple standard model of whole-mantle convection, including a factor 40 viscosity increase from the upper to the lower mantle and predominantly internal heat generation, reveals downwellings related to Farallon and Tethys subduction. Adding 35% bottom heating from the core has the predictable effect of producing prominent high-temperature anomalies and a strong thermal boundary layer at the base of the mantle. Significantly delaying mantle flow through the transition zone either by modelling the dynamic effects of an endothermic phase reaction or by including a steep, factor 100, viscosity rise from the upper to the lower mantle results in substantial transition-zone heterogeneity, enhanced by the effects of trench migration implicit in the assimilated plate-motion history. An expected result is the failure to account for heterogeneity structure in the deepest mantle below 1500 km, which is influenced by Jurassic plate motions and thus cannot be modelled from sequential assimilation of plate motion histories limited in age to the Cretaceous. This result implies that sequential assimilation of past plate-motion models is ineffective in studying the temporal evolution of core-mantle-boundary heterogeneity, and that a method for extrapolating present-day information backwards in time is required. For short time periods (of the order of perhaps a few tens of Myr) such a method exists in the form of crude 'backward' convection calculations. For longer time periods (of the order of a mantle overturn), a rigorous approach to extrapolating information back in time exists in the form of iterative nonlinear optimization methods that carry assimilated information into the past through the use of an adjoint mantle convection model.

Ixeris dentata Extract Increases Salivary Secretion through the Regulation of Endoplasmic Reticulum Stress in a Diabetes-Induced Xerostomia Rat Model.

PubMed

Bhattarai, Kashi Raj; Lee, Hwa-Young; Kim, Seung-Hyun; Kim, Hyung-Ryong; Chae, Han-Jung

2018-04-02

This study aimed to investigate the molecular mechanism of diabetes mellitus (DM)-induced dry mouth and an application of natural products from Ixeris dentata (IXD), a recently suggested regulator of amylase secretion in salivary cells. Vehicle-treated or diabetic rats were orally treated with either water or an IXD extract for 10 days to observe the effect on salivary flow. We found that the IXD extract increased aquaporin 5 (AQP5) and alpha-amylase protein expression in the submandibular gland along with salivary flow rate. Similarly, the IXD extract and its purified compound increased amylase secretion in high glucose-exposed human salivary gland cells. Furthermore, increased endoplasmic reticulum stress response in the submandibular gland of diabetic rats was inhibited by treatment with the IXD extract, suggesting that IXD extract treatment improves the ER environment by increasing the protein folding capacity. Thus, pharmacological treatment with the IXD extract is suggested to relieve DM-induced dry mouth symptoms.

Balancing tissue perfusion demands: cardiovascular dynamics of Cancer magister during exposure to low salinity and hypoxia.

PubMed

McGaw, Iain J; McMahon, Brian R

2003-01-01

Decapod crustaceans inhabit aquatic environments that are frequently subjected to changes in salinity and oxygen content. The physiological responses of decapod crustaceans to either salinity or hypoxia are well documented; however, there are many fewer reports on the physiological responses during exposure to these parameters in combination. We investigated the effects of simultaneous and sequential combinations of low salinity and hypoxia on the cardiovascular physiology of the Dungeness crab, Cancer magister. Heart rate, as well as haemolymph flow rates through the anterolateral, hepatic, sternal and posterior arteries were measured using a pulsed-Doppler flowmeter. Summation of flows allowed calculation of cardiac output and division of this by heart rate yielded stroke volume. When hypoxia and low salinity were encountered simultaneously, the observed changes in cardiac properties tended to be a mix of both factors. Hypoxia caused a bradycardia, whereas exposure to low salinity was associated with a tachycardia. However, the hypoxic conditions had the dominant effect on heart rate. Although hypoxia caused an increase in stroke volume of the heart, the low salinity had a more pronounced effect, causing an overall decrease in stroke volume. The patterns of haemolymph flow through the arterial system also varied when hypoxia and low salinity were offered together. The resulting responses were a mix of those resulting from exposure to either parameter alone. When low salinity and hypoxia were offered sequentially, the parameter experienced first tended to have the dominant effect on cardiac function and haemolymph flows. Low salinity exposure was associated with an increase in heart rate, a decrease in stroke volume and cardiac output, and a concomitant decrease in haemolymph flow rates. Subsequent exposure to hypoxic conditions caused a slight decrease in rate, but other cardiovascular variables were largely unaffected. In contrast, when low salinity followed acclimation to hypoxic conditions, apart from an increased heart rate, there were no other cardiovascular changes associated with the low salinity episode. The implications of these changes in cardiovascular dynamics are discussed in relation to physiological mechanisms and the ecology of decapod crustaceans, in hypoxic or low salinity environments. Copyright 2003, Wiley-Liss, Inc.

Sequential reductive and oxidative biodegradation of chloroethenes stimulated in a coupled bioelectro-process.

PubMed

Lohner, Svenja T; Becker, Dirk; Mangold, Klaus-Michael; Tiehm, Andreas

2011-08-01

This article for the first time demonstrates successful application of electrochemical processes to stimulate sequential reductive/oxidative microbial degradation of perchloroethene (PCE) in mineral medium and in contaminated groundwater. In a flow-through column system, hydrogen generation at the cathode supported reductive dechlorination of PCE to cis-dichloroethene (cDCE), vinyl chloride (VC), and ethene (ETH). Electrolytically generated oxygen at the anode allowed subsequent oxidative degradation of the lower chlorinated metabolites. Aerobic cometabolic degradation of cDCE proved to be the bottleneck for complete metabolite elimination. Total removal of chloroethenes was demonstrated for a PCE load of approximately 1.5 μmol/d. In mineral medium, long-term operation with stainless steel electrodes was demonstrated for more than 300 days. In contaminated groundwater, corrosion of the stainless steel anode occurred, whereas DSA (dimensionally stable anodes) proved to be stable. Precipitation of calcareous deposits was observed at the cathode, resulting in a higher voltage demand and reduced dechlorination activity. With DSA and groundwater from a contaminated site, complete degradation of chloroethenes in groundwater was obtained for two months thus demonstrating the feasibility of the sequential bioelectro-approach for field application.

Sequential ultrasound-microwave assisted acid extraction (UMAE) of pectin from pomelo peels.

PubMed

Liew, Shan Qin; Ngoh, Gek Cheng; Yusoff, Rozita; Teoh, Wen Hui

2016-12-01

This study aims to optimize sequential ultrasound-microwave assisted extraction (UMAE) on pomelo peel using citric acid. The effects of pH, sonication time, microwave power and irradiation time on the yield and the degree of esterification (DE) of pectin were investigated. Under optimized conditions of pH 1.80, 27.52min sonication followed by 6.40min microwave irradiation at 643.44W, the yield and the DE value of pectin obtained was respectively at 38.00% and 56.88%. Based upon optimized UMAE condition, the pectin from microwave-ultrasound assisted extraction (MUAE), ultrasound assisted extraction (UAE) and microwave assisted extraction (MAE) were studied. The yield of pectin adopting the UMAE was higher than all other techniques in the order of UMAE>MUAE>MAE>UAE. The pectin's galacturonic acid content obtained from combined extraction technique is higher than that obtained from sole extraction technique and the pectin gel produced from various techniques exhibited a pseudoplastic behaviour. The morphological structures of pectin extracted from MUAE and MAE closely resemble each other. The extracted pectin from UMAE with smaller and more regular surface differs greatly from that of UAE. This has substantiated the highest pectin yield of 36.33% from UMAE and further signified their compatibility and potentiality in pectin extraction. Copyright © 2016 Elsevier B.V. All rights reserved.

Poleward Tropical Moisture Transport and its Link to Four Sequential Extreme Weather Events over North America in October 2007

NASA Astrophysics Data System (ADS)

Bosart, L. F.; Cordeira, J. M.; Archambault, H. M.; Moore, B. J.

2014-12-01

A case of four sequentially linked extreme weather events (EWEs) during 22 - 31 October 2007 which included wildfires in southern California, cold surges in northern and eastern Mexico, widespread heavy rain in the eastern United Sates, and heavy rains in southern Mexico is presented. These EWEs were preceded by a rapid dynamically driven rapid amplification of the upper-level flow across the North Pacific and North America associated with the formation of a large-amplitude Rossby wave train (RWT) through downstream baroclinic development involving multiple tropical and polar disturbance interactions with the North Pacific jet stream. The primary contributors to the formation of the large-amplitude RWT were two sequential upper-level polar disturbances, a diabatic Rossby vortex, western North Pacific TC Kajiki, and migratory extratropical cyclones (ECs). Deep subtropical and tropical moisture plumes resembling "atmospheric rivers" drawn poleward along warm conveyor belts into the warm sectors of these ECs played a critical role in further amplifying the downstream upper-level ridges based on an Eulerian analysis of negative potential vorticity advection by the irrotational wind and a Lagrangian trajectory analysis of tropical and subtropical moisture sources. In particular, these atmospheric rivers extending poleward from TC Kajiki and from the subtropical eastern North Pacific into the warm sectors of polar disturbance-generated ECs over the western and eastern North Pacific, respectively, bolstered latent heat release and ridge building and contributed to additional upper-level flow amplification. The EWEs occurred subsequent to anticyclonic wave breaking over western North America and the concomitant downstream formation of a meridionally elongated potential vorticity streamer over the central United States. The resulting high-amplitude flow pattern over North America favored the formation of the aforementioned EWEs by promoting an extensive meridional exchange of air masses from high and low latitudes.

Physics-based investigation of negative ion behavior in a negative-ion-rich plasma using integrated diagnostics

NASA Astrophysics Data System (ADS)

Tsumori, K.; Takeiri, Y.; Ikeda, K.; Nakano, H.; Geng, S.; Kisaki, M.; Nagaoka, K.; Tokuzawa, T.; Wada, M.; Sasaki, K.; Nishiyama, S.; Goto, M.; Osakabe, M.

2017-08-01

Total power of 16 MW has been successfully delivered to the plasma confined in the Large Helical Device (LHD) from three Neutral Beam Injectors (NBIs) equipped with negative hydrogen (H-) ion sources. However, the detailed mechanisms from production through extraction of H- ions are still yet to be clarified and a similar size ion source on an independent acceleration test bench called Research and development Negative Ion Source (RNIS) serves as the facility to study physics related to H- production and transport for further improvement of NBI. The production of negative-ion-rich plasma and the H- ions behavior in the beam extraction region in RNIS is being investigated by employing an integrated diagnostic system. Flow patterns of electrons, positive ions and H- ions in the extraction region are described in a two-dimensional map. The measured flow patterns indicate the existence a stagnation region, where the H- flow changes the direction at a distance about 20 mm from the plasma grid. The pattern also suggested the H- flow originated from plasma grid (PG) surface that turned back toward extraction apertures. The turning region seems formed by a layer of combined magnetic field produced by the magnetic filter field and the Electron-Deflection Magnetic (EDM) field created by magnets installed in the extraction electrode.

Hot air injection for removal of dense, non-aqueous-phase liquid contaminants from low-permeability soils

DOE Office of Scientific and Technical Information (OSTI.GOV)

Payne, F.C.

1996-08-01

The performance of soil vapor extraction systems for the recovery of volatile and semi-volatile organic compounds is potentially enhanced by the injection of heated air to increase soil temperatures. The soil temperature increase is expected to improve soil vapor extraction (SVE) performance by increasing target compound vapor pressures and by increasing soil permeability through drying. The vapor pressure increase due to temperature rise relieves the vapor pressure limit on the feasibility of soil vapor extraction. However, the system still requires an air flow through the soil system to deliver heat and to recover mobilized contaminants. Although the soil permeability canmore » be increased through drying, very low permeability soils and low permeability soils adjacent to high permeability air flow pathways will be treated slowly, if at all. AR thermal enhancement methods face this limitation. Heated air injection offers advantages relative to other thermal techniques, including low capital and operation costs. Heated air injection is at a disadvantage relative to other thermal techniques due to the low heat capacity of air. To be effective, heated air injection requires that higher air flows be established than for steam injection or radio frequency heating. Heated air injection is not economically feasible for the stratified soil system developed as a standard test for this document. This is due to the inability to restrict heated air flow to the clay stratum when a low-resistance air flow pathway is available in the adjoining sand. However, the technology should be especially attractive, both technically and economically, for low-volatile contaminant recovery from relatively homogeneous soil formations. 16 refs., 2 tabs.« less

High arsenic groundwater in the Guide basin, northwestern China: Distribution and genesis mechanisms.

PubMed

Wang, Zhen; Guo, Huaming; Xiu, Wei; Wang, Jiao; Shen, Mengmeng

2018-05-30

High arsenic (As) groundwater has been found in Pliocene confined aquifers at depths from 100 to 300 m of the Guide basin, but little is known on the main hydrogeochemical processes leading to its elevated concentrations. Ninety-seven water samples and fifty-three sediment samples were collected for chemical and/or isotopic analysis. Concentrations of As in groundwater of confined aquifer range from 9.9 to 377 μg/L (average 109 μg/L), which generally show a sharply increasing trend along with NH 4 + , HCO 3 - , CO 3 2- and TOC along the inferred flow path, while NO 3 - , SO 4 2- /Cl - and redox potential (Eh) have decreasing trends. Results of sequential extraction show that As bound to amorphous and crystalline Fe oxide minerals are the main As forms, accounting for around 50% of total As in sediments. Reductive dissolution of As-bearing Fe(III) oxide minerals under reducing conditions in confined aquifers lead to the mobilization of As in groundwater. In addition, alkaline environment and high concentrations of HCO 3 - and CO 3 2- may make contributions to As enrichment in groundwater. High As groundwater in confined aquifer continuously flows out on the ground surface through tens of artesian wells, which may potentially contaminate low As groundwater in unconfined aquifer. Thus, further investigation is needed to evaluate long-term variations of water chemistry of low As groundwater and assess vulnerability of unconfined aquifer to As contamination. Copyright © 2018 Elsevier B.V. All rights reserved.

Optimum periodicity of repeated contractile actions applied in mass transport

NASA Astrophysics Data System (ADS)

Ahn, Sungsook; Lee, Sang Joon

2015-01-01

Dynamically repeated periodic patterns are abundant in natural and artificial systems, such as tides, heart beats, stock prices, and the like. The characteristic repeatability and periodicity are expected to be optimized in effective system-specific functions. In this study, such optimum periodicity is experimentally evaluated in terms of effective mass transport using one-valve and multi-valve systems working in contractile fluid flows. A set of nanoscale gating functions is utilized, operating in nanocomposite networks through which permeates selectively pass under characteristic contractile actions. Optimized contractile periodicity exists for effective energy impartment to flow in a one-valve system. In the sequential contractile actions for a multi-valve system, synchronization with the fluid flow is critical for effective mass transport. This study provides fundamental understanding on the various repeated periodic patterns and dynamic repeatability occurring in nature and mechanical systems, which are useful for broad applications.

Direct power production from a water salinity difference in a membrane-modified supercapacitor flow cell.

PubMed

Sales, B B; Saakes, M; Post, J W; Buisman, C J N; Biesheuvel, P M; Hamelers, H V M

2010-07-15

The entropy increase of mixing two solutions of different salt concentrations can be harnessed to generate electrical energy. Worldwide, the potential of this resource, the controlled mixing of river and seawater, is enormous, but existing conversion technologies are still complex and expensive. Here we present a small-scale device that directly generates electrical power from the sequential flow of fresh and saline water, without the need for auxiliary processes or converters. The device consists of a sandwich of porous "supercapacitor" electrodes, ion-exchange membranes, and a spacer and can be further miniaturized or scaled-out. Our results demonstrate that alternating the flow of saline and fresh water through a capacitive cell allows direct autogeneration of voltage and current and consequently leads to power generation. Theoretical calculations aid in providing directions for further optimization of the properties of membranes and electrodes.

Optimization, formulation, and characterization of multiflavonoids-loaded flavanosome by bulk or sequential technique

PubMed Central

Karthivashan, Govindarajan; Masarudin, Mas Jaffri; Kura, Aminu Umar; Abas, Faridah; Fakurazi, Sharida

2016-01-01

This study involves adaptation of bulk or sequential technique to load multiple flavonoids in a single phytosome, which can be termed as “flavonosome”. Three widely established and therapeutically valuable flavonoids, such as quercetin (Q), kaempferol (K), and apigenin (A), were quantified in the ethyl acetate fraction of Moringa oleifera leaves extract and were commercially obtained and incorporated in a single flavonosome (QKA–phosphatidylcholine) through four different methods of synthesis – bulk (M1) and serialized (M2) co-sonication and bulk (M3) and sequential (M4) co-loading. The study also established an optimal formulation method based on screening the synthesized flavonosomes with respect to their size, charge, polydispersity index, morphology, drug–carrier interaction, antioxidant potential through in vitro 1,1-diphenyl-2-picrylhydrazyl kinetics, and cytotoxicity evaluation against human hepatoma cell line (HepaRG). Furthermore, entrapment and loading efficiency of flavonoids in the optimal flavonosome have been identified. Among the four synthesis methods, sequential loading technique has been optimized as the best method for the synthesis of QKA–phosphatidylcholine flavonosome, which revealed an average diameter of 375.93±33.61 nm, with a zeta potential of −39.07±3.55 mV, and the entrapment efficiency was >98% for all the flavonoids, whereas the drug-loading capacity of Q, K, and A was 31.63%±0.17%, 34.51%±2.07%, and 31.79%±0.01%, respectively. The in vitro 1,1-diphenyl-2-picrylhydrazyl kinetics of the flavonoids indirectly depicts the release kinetic behavior of the flavonoids from the carrier. The QKA-loaded flavonosome had no indication of toxicity toward human hepatoma cell line as shown by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide result, wherein even at the higher concentration of 200 µg/mL, the flavonosomes exert >85% of cell viability. These results suggest that sequential loading technique may be a promising nanodrug delivery system for loading multiflavonoids in a single entity with sustained activity as an antioxidant, hepatoprotective, and hepatosupplement candidate. PMID:27555765

Optimization, formulation, and characterization of multiflavonoids-loaded flavanosome by bulk or sequential technique.

PubMed

Karthivashan, Govindarajan; Masarudin, Mas Jaffri; Kura, Aminu Umar; Abas, Faridah; Fakurazi, Sharida

2016-01-01

This study involves adaptation of bulk or sequential technique to load multiple flavonoids in a single phytosome, which can be termed as "flavonosome". Three widely established and therapeutically valuable flavonoids, such as quercetin (Q), kaempferol (K), and apigenin (A), were quantified in the ethyl acetate fraction of Moringa oleifera leaves extract and were commercially obtained and incorporated in a single flavonosome (QKA-phosphatidylcholine) through four different methods of synthesis - bulk (M1) and serialized (M2) co-sonication and bulk (M3) and sequential (M4) co-loading. The study also established an optimal formulation method based on screening the synthesized flavonosomes with respect to their size, charge, polydispersity index, morphology, drug-carrier interaction, antioxidant potential through in vitro 1,1-diphenyl-2-picrylhydrazyl kinetics, and cytotoxicity evaluation against human hepatoma cell line (HepaRG). Furthermore, entrapment and loading efficiency of flavonoids in the optimal flavonosome have been identified. Among the four synthesis methods, sequential loading technique has been optimized as the best method for the synthesis of QKA-phosphatidylcholine flavonosome, which revealed an average diameter of 375.93±33.61 nm, with a zeta potential of -39.07±3.55 mV, and the entrapment efficiency was >98% for all the flavonoids, whereas the drug-loading capacity of Q, K, and A was 31.63%±0.17%, 34.51%±2.07%, and 31.79%±0.01%, respectively. The in vitro 1,1-diphenyl-2-picrylhydrazyl kinetics of the flavonoids indirectly depicts the release kinetic behavior of the flavonoids from the carrier. The QKA-loaded flavonosome had no indication of toxicity toward human hepatoma cell line as shown by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide result, wherein even at the higher concentration of 200 µg/mL, the flavonosomes exert >85% of cell viability. These results suggest that sequential loading technique may be a promising nanodrug delivery system for loading multiflavonoids in a single entity with sustained activity as an antioxidant, hepatoprotective, and hepatosupplement candidate.

A multi-approach feature extractions for iris recognition

NASA Astrophysics Data System (ADS)

Sanpachai, H.; Settapong, M.

2014-04-01

Biometrics is a promising technique that is used to identify individual traits and characteristics. Iris recognition is one of the most reliable biometric methods. As iris texture and color is fully developed within a year of birth, it remains unchanged throughout a person's life. Contrary to fingerprint, which can be altered due to several aspects including accidental damage, dry or oily skin and dust. Although iris recognition has been studied for more than a decade, there are limited commercial products available due to its arduous requirement such as camera resolution, hardware size, expensive equipment and computational complexity. However, at the present time, technology has overcome these obstacles. Iris recognition can be done through several sequential steps which include pre-processing, features extractions, post-processing, and matching stage. In this paper, we adopted the directional high-low pass filter for feature extraction. A box-counting fractal dimension and Iris code have been proposed as feature representations. Our approach has been tested on CASIA Iris Image database and the results are considered successful.

Nuclear events of apoptosis in vitro in cell-free mitotic extracts: a model system for analysis of the active phase of apoptosis

PubMed Central

1993-01-01

We have developed a cell-free system that induces the morphological transformations characteristic of apoptosis in isolated nuclei. The system uses extracts prepared from mitotic chicken hepatoma cells following a sequential S phase/M phase synchronization. When nuclei are added to these extracts, the chromatin becomes highly condensed into spherical domains that ultimately extrude through the nuclear envelope, forming apoptotic bodies. The process is highly synchronous, and the structural changes are completed within 60 min. Coincident with these morphological changes, the nuclear DNA is cleaved into a nucleosomal ladder. Both processes are inhibited by Zn2+, an inhibitor of apoptosis in intact cells. Nuclear lamina disassembly accompanies these structural changes in added nuclei, and we show that lamina disassembly is a characteristic feature of apoptosis in intact cells of mouse, human and chicken. This system may provide a powerful means of dissecting the biochemical mechanisms underlying the final stages of apoptosis. PMID:8408207

Effect of sequential pneumatic compression therapy on venous blood velocity, refilling time, pain and quality of life in women with varicose veins: a randomized control study

PubMed Central

Yamany, Abeer; Hamdy, Bassant

2016-01-01

[Purpose] The aim of this study was to investigate the effects of sequential pneumatic compression therapy on venous blood flow, refilling time, pain level, and quality of life in women with varicose veins. [Subjects and Methods] Twenty-eight females with varicose veins were selected and randomly allocated to a control group, and experimental group. Maximum and mean venous blood velocities, the refilling time, pain by visual analog scale and quality of life by Aberdeen Varicose Veins Questionnaire were measured in all patients before and after six weeks of treatment. Both groups received lower extremity exercises; in addition, patients in the experimental group received sequential pneumatic compression therapy for 30 minutes daily, five days a week for six weeks. [Results] All measured parameters improved significantly in both groups, comparison of post treatment measurements between groups showed that the maximum and mean blood flow velocity, the pain level, and quality of life were significantly higher in the experimental group compared with the control group. On the other hand there was no significant difference between groups for refilling time. [Conclusion] Sequential pneumatic compression therapy with the applied parameters was an effective modality for increasing venous blood flow, reducing pain, and improving quality of women life with varicose veins. PMID:27512247

Fractionation of metals by sequential extraction procedures (BCR and Tessier) in soil exposed to fire of wide temperature range

NASA Astrophysics Data System (ADS)

Fajkovic, Hana; Rončević, Sanda; Nemet, Ivan; Prohić, Esad; Leontić-Vazdar, Dana

2017-04-01

Forest fire presents serious problem, especially in Mediterranean Region. Effects of fire are numerous, from climate change and deforestation to loss of soil organic matter and changes in soil properties. One of the effects, not well documented, is possible redistribution and/or remobilisation of pollutants previously deposited in the soil, due to the new physical and chemical soil properties and changes in equilibrium conditions. For understanding and predicting possible redistribution and/or remobilisation of potential pollutants from soil, affected by fire different in temperature, several laboratory investigations were carried out. To evaluate the influence of organic matter on soil under fire, three soil samples were analysed and compared: (a) the one with added coniferous organic matter; (b) deciduous organic matter (b) and (c) soil without additional organic matter. Type of organic matter is closely related to pH of soil, as pH is influencing the mobility of some pollutants, e.g. metals. For that reason pH was also measured through all experimental steps. Each of mentioned soil samples (a, b and c) were heated at 1+3 different temperatures (25°C, 200°C, 500°C and 850°C). After heating, whereby fire effect on soil was simulated, samples were analysed by BCR protocol with the addition of a first step of sequential extraction procedure by Tessier and analysis of residual by aqua regia. Element fractionation of heavy metals by this procedure was used to determine the amounts of selected elements (Al, Cd, Cr, Co, Cu, Fe, Mn, Ni, Pb and Zn). Selected metal concentrations were determined using inductively coupled plasma atomic emission spectrometer. Further on, loss of organic matter was calculated after each heating procedure as well as the mineral composition. The mineral composition was determined using an X-ray diffraction. From obtained results, it can be concluded that temperature has an influence on concentration of elements in specific step of sequential extraction procedures. The first step of Tessier and BCR extraction of samples heated at 250°C and 500°C showed increasing trend of elemental concentrations. Results of these steps are especially important since they indicate mobile fraction of the elements (exchangeable, water- and acid-soluble fraction), which can easily affect the environment. Extraction procedures of samples combusted at 850°C showed that decrease in measured elemental content occurred. Some correlation is also noticed between type of organic matter, pH and concentration of analysed elements.

Robust Sensing of Approaching Vehicles Relying on Acoustic Cues

PubMed Central

Mizumachi, Mitsunori; Kaminuma, Atsunobu; Ono, Nobutaka; Ando, Shigeru

2014-01-01

The latest developments in automobile design have allowed them to be equipped with various sensing devices. Multiple sensors such as cameras and radar systems can be simultaneously used for active safety systems in order to overcome blind spots of individual sensors. This paper proposes a novel sensing technique for catching up and tracking an approaching vehicle relying on an acoustic cue. First, it is necessary to extract a robust spatial feature from noisy acoustical observations. In this paper, the spatio-temporal gradient method is employed for the feature extraction. Then, the spatial feature is filtered out through sequential state estimation. A particle filter is employed to cope with a highly non-linear problem. Feasibility of the proposed method has been confirmed with real acoustical observations, which are obtained by microphones outside a cruising vehicle. PMID:24887038

Protein classification using sequential pattern mining.

PubMed

Exarchos, Themis P; Papaloukas, Costas; Lampros, Christos; Fotiadis, Dimitrios I

2006-01-01

Protein classification in terms of fold recognition can be employed to determine the structural and functional properties of a newly discovered protein. In this work sequential pattern mining (SPM) is utilized for sequence-based fold recognition. One of the most efficient SPM algorithms, cSPADE, is employed for protein primary structure analysis. Then a classifier uses the extracted sequential patterns for classifying proteins of unknown structure in the appropriate fold category. The proposed methodology exhibited an overall accuracy of 36% in a multi-class problem of 17 candidate categories. The classification performance reaches up to 65% when the three most probable protein folds are considered.

Design and optimization of a semicontinuous hot-cold extraction of polyphenols from grape pomace.

PubMed

Monrad, Jeana K; Srinivas, Keerthi; Howard, Luke R; King, Jerry W

2012-06-06

Grape pomace contains appreciable amounts of polyphenolic compounds such as anthocyanins and procyanidins which can be recovered for use as food supplements. The extraction of these polyphenols from the pomace is usually accomplished at slightly elevated temperatures, frequently employing hydroethanolic solvents. Due to governmental regulations and the cost involved in using ethanol as a solvent, as well as the loss in polyphenolics due to thermal degradation, improved extraction techniques are required. In this study, a semicontinuous extraction apparatus employing only water was developed to maximize the recovery of anthocyanins and procyanidins from red grape pomace (Vitis vinifera). Water is preheated prior to its entry to the extraction cell containing the grape pomace sample, where it is allowed to then flow continuously through the unheated extraction vessel prior to its collection at ambient conditions. Extraction variables that impacted the polyphenolic recovery included pomace moisture content (crude or dried), sample mass, water flow rate, and extraction temperature. A response surface method was used to analyze the results from the extraction, and the optimal conditions were found to be 140 °C and 9 mL/min water flow rate. These conditions can produce an extract containing 130 mg/100 g DW of anthocyanins and 2077 mg/100 g DW of procyanidins. Higher yields of polyphenolics were observed using crude (wet) rather than dried pomace, hence avoiding the need to dry the pomace prior to extraction. The described semicontinuous extraction method using only water as the extraction solvent under subcritical conditions allowed the efficient extraction of polyphenols from red grape pomace without the attendant loss of polyphenolic content due to having to heat the extraction vessel prior to commencement of extraction.

Determination of As(III) and total inorganic As in water samples using an on-line solid phase extraction and flow injection hydride generation atomic absorption spectrometry.

PubMed

Sigrist, Mirna; Albertengo, Antonela; Beldoménico, Horacio; Tudino, Mabel

2011-04-15

A simple and robust on-line sequential injection system based on solid phase extraction (SPE) coupled to a flow injection hydride generation atomic absorption spectrometer (FI-HGAAS) with a heated quartz tube atomizer (QTA) was developed and optimized for the determination of As(III) in groundwater without any kind of sample pretreatment. The method was based on the selective retention of inorganic As(V) that was carried out by passing the filtered original sample through a cartridge containing a chloride-form strong anion exchanger. Thus the most toxic form, inorganic As(III), was determined fast and directly by AsH(3) generation using 3.5 mol L(-1) HCl as carrier solution and 0.35% (m/v) NaBH(4) in 0.025% NaOH as the reductant. Since the uptake of As(V) should be interfered by several anions of natural occurrence in waters, the effect of Cl(-), SO(4)(2-), NO(3)(-), HPO(4)(2-), HCO(3)(-) on retention was evaluated and discussed. The total soluble inorganic arsenic concentration was determined on aliquots of filtered samples acidified with concentrated HCl and pre-reduced with 5% KI-5% C(6)H(8)O(6) solution. The concentration of As(V) was calculated by difference between the total soluble inorganic arsenic and As(III) concentrations. Detection limits (LODs) of 0.5 μg L(-1) and 0.6 μg L(-1) for As(III) and inorganic total As, respectively, were obtained for a 500 μL sample volume. The obtained limits of detection allowed testing the water quality according to the national and international regulations. The analytical recovery for water samples spiked with As(III) ranged between 98% and 106%. The sampling throughput for As(III) determination was 60 samplesh(-1). The device for groundwater sampling was especially designed for the authors. Metallic components were avoided and the contact between the sample and the atmospheric oxygen was carried to a minimum. On-field arsenic species separation was performed through the employ of a serial connection of membrane filters and anion-exchange cartridges. Advantages derived from this approach were evaluated. HPLC-ICPMS was employed to study the consistency of the analytical results. Copyright © 2011 Elsevier B.V. All rights reserved.

A microfluidic needle for sampling and delivery of chemical signals by segmented flows

NASA Astrophysics Data System (ADS)

Feng, Shilun; Liu, Guozhen; Jiang, Lianmei; Zhu, Yonggang; Goldys, Ewa M.; Inglis, David W.

2017-10-01

We have developed a microfluidic needle-like device that can extract and deliver nanoliter samples. The device consists of a T-junction to form segmented flows, parallel channels to and from the needle tip, and seven hydrophilic capillaries at the tip that form a phase-extraction region. The main microchannel is hydrophobic and carries segmented flows of water-in-oil. The hydrophilic capillaries transport the aqueous phase with a nearly zero pressure gradient but require a pressure gradient of 19 kPa for mineral oil to invade and flow through. Using this device, we demonstrate the delivery of nanoliter droplets and demonstrate sampling through the formation of droplets at the tip of our device. During sampling, we recorded the fluorescence intensities of the droplets formed at the tip while varying the concentration of dye outside the tip. We measured a chemical signal response time of approximately 3 s. The linear relationship between the recorded fluorescence intensity of samples and the external dye concentration (10-40 μg/ml) indicates that this device is capable of performing quantitative, real-time measurements of rapidly varying chemical signals.

Extracting a mix parameter from 2D radiography of variable density flow

NASA Astrophysics Data System (ADS)

Kurien, Susan; Doss, Forrest; Livescu, Daniel

2017-11-01

A methodology is presented for extracting quantities related to the statistical description of the mixing state from the 2D radiographic image of a flow. X-ray attenuation through a target flow is given by the Beer-Lambert law which exponentially damps the incident beam intensity by a factor proportional to the density, opacity and thickness of the target. By making reasonable assumptions for the mean density, opacity and effective thickness of the target flow, we estimate the contribution of density fluctuations to the attenuation. The fluctuations thus inferred may be used to form the correlation of density and specific-volume, averaged across the thickness of the flow in the direction of the beam. This correlation function, denoted by b in RANS modeling, quantifies turbulent mixing in variable density flows. The scheme is tested using DNS data computed for variable-density buoyancy-driven mixing. We quantify the deficits in the extracted value of b due to target thickness, Atwood number, and modeled noise in the incident beam. This analysis corroborates the proposed scheme to infer the mix parameter from thin targets at moderate to low Atwood numbers. The scheme is then applied to an image of counter-shear flow obtained from experiments at the National Ignition Facility. US Department of Energy.

Regulation of coronary blood flow

PubMed Central

Gorlin, Richard

1971-01-01

Coronary blood flow is dependent upon arterial pressure, diastolic time, and small vessel resistance. The system is regulated to achieve a low flow high oxygen extraction and low myocardial Po2. This setting is sensitive to change in oxygen needs. Regulation of blood flow occurs primarily through local intrinsic regulation, most likely through production of vasodilating metabolites in response to minimal degrees of ischaemia. Local regulation appears to dominate over remote regulation in most circumstances. Blood flow distribution to the myocardium is depth dependent as well as regional in variation. Both types of distribution of blood flow are profoundly disturbed in the presence of obstructive coronary atherosclerosis. This results in either concentric myocardial shells or patchy transmural zones of selective ischaemia with clear-cut but local abnormalities in metabolism and performance. Images PMID:4929442

Relations between work and entropy production for general information-driven, finite-state engines

NASA Astrophysics Data System (ADS)

Merhav, Neri

2017-02-01

We consider a system model of a general finite-state machine (ratchet) that simultaneously interacts with three kinds of reservoirs: a heat reservoir, a work reservoir, and an information reservoir, the latter being taken to be a running digital tape whose symbols interact sequentially with the machine. As has been shown in earlier work, this finite-state machine can act as a demon (with memory), which creates a net flow of energy from the heat reservoir into the work reservoir (thus extracting useful work) at the price of increasing the entropy of the information reservoir. Under very few assumptions, we propose a simple derivation of a family of inequalities that relate the work extraction with the entropy production. These inequalities can be seen as either upper bounds on the extractable work or as lower bounds on the entropy production, depending on the point of view. Many of these bounds are relatively easy to calculate and they are tight in the sense that equality can be approached arbitrarily closely. In their basic forms, these inequalities are applicable to any finite number of cycles (and not only asymptotically), and for a general input information sequence (possibly correlated), which is not necessarily assumed even stationary. Several known results are obtained as special cases.

An integrated simulator of structure and anisotropic flow in gas diffusion layers with hydrophobic additives

NASA Astrophysics Data System (ADS)

Burganos, Vasilis N.; Skouras, Eugene D.; Kalarakis, Alexandros N.

2017-10-01

The lattice-Boltzmann (LB) method is used in this work to reproduce the controlled addition of binder and hydrophobicity-promoting agents, like polytetrafluoroethylene (PTFE), into gas diffusion layers (GDLs) and to predict flow permeabilities in the through- and in-plane directions. The present simulator manages to reproduce spreading of binder and hydrophobic additives, sequentially, into the neat fibrous layer using a two-phase flow model. Gas flow simulation is achieved by the same code, sidestepping the need for a post-processing flow code and avoiding the usual input/output and data interface problems that arise in other techniques. Compression effects on flow anisotropy of the impregnated GDL are also studied. The permeability predictions for different compression levels and for different binder or PTFE loadings are found to compare well with experimental data for commercial GDL products and with computational fluid dynamics (CFD) predictions. Alternatively, the PTFE-impregnated structure is reproduced from Scanning Electron Microscopy (SEM) images using an independent, purely geometrical approach. A comparison of the two approaches is made regarding their adequacy to reproduce correctly the main structural features of the GDL and to predict anisotropic flow permeabilities at different volume fractions of binder and hydrophobic additives.

Gas flow headspace liquid phase microextraction.

PubMed

Yang, Cui; Qiu, Jinxue; Ren, Chunyan; Piao, Xiangfan; Li, Xifeng; Wu, Xue; Li, Donghao

2009-11-06

There is a trend towards the use of enrichment techniques such as microextraction in the analysis of trace chemicals. Based on the theory of ideal gases, theory of gas chromatography and the original headspace liquid phase microextraction (HS-LPME) technique, a simple gas flow headspace liquid phase microextraction (GF-HS-LPME) technique has been developed, where the extracting gas phase volume is increased using a gas flow. The system is an open system, where an inert gas containing the target compounds flows continuously through a special gas outlet channel (D=1.8mm), and the target compounds are trapped on a solvent microdrop (2.4 microL) hanging on the microsyringe tip, as a result, a high enrichment factor is obtained. The parameters affecting the enrichment factor, such as the gas flow rate, the position of the microdrop, the diameter of the gas outlet channel, the temperatures of the extracting solvent and of the sample, and the extraction time, were systematically optimized for four types of polycyclic aromatic hydrocarbons. The results were compared with results obtained from HS-LPME. Under the optimized conditions (where the extraction time and the volume of the extracting sample vial were fixed at 20min and 10mL, respectively), detection limits (S/N=3) were approximately a factor of 4 lower than those for the original HS-LPME technique. The method was validated by comparison of the GF-HS-LPME and HS-LPME techniques using data for PAHs from environmental sediment samples.

Towards DMD-Based Estimation and Control of Flow Separation using an Array of Surface Pressure Sensors

NASA Astrophysics Data System (ADS)

Deem, Eric; Cattafesta, Louis; Zhang, Hao; Rowley, Clancy

2016-11-01

Closed-loop control of flow separation requires the spatio-temporal states of the flow to be fed back through the controller in real time. Previously, static and dynamic estimation methods have been employed that provide reduced-order model estimates of the POD-coefficients of the flow velocity using surface pressure measurements. However, this requires a "learning" dataset a priori. This approach is effective as long as the dynamics during control do not stray from the learning dataset. Since only a few dynamical features are required for feedback control of flow separation, many of the details provided by full-field snapshots are superfluous. This motivates a state-observation technique that extracts key dynamical features directly from surface pressure, without requiring PIV snapshots. The results of identifying DMD modes of separated flow through an array of surface pressure sensors in real-time are presented. This is accomplished by employing streaming DMD "on the fly" to surface pressure snapshots. These modal characteristics exhibit striking similarities to those extracted from PIV data and the pressure field obtained via solving Poisson's equation. Progress towards closed-loop separation control based on the dynamic modes of surface pressure will be discussed. Supported by AFOSR Grant FA9550-14-1-0289.

Simultaneous determination of mequindox, quinocetone, and their major metabolites in chicken and pork by UPLC-MS/MS

USDA-ARS?s Scientific Manuscript database

This research presents a sensitive and confirmatory multi-residue method for mequindox (MEQ), quinocetone (QCT), and their 11 metabolites in chicken and pork samples. After extracted with acetonitrile-ethyl acetate, acidulated, and extracted again with ethyl acetate sequentially, each sample was pu...

ENVIRONMENTAL TECHNOLOGY VERIFICATION REPORT, PCB DETECTION TECHNOLOGY, HYBRIZYME DELFIA TM ASSAY

EPA Science Inventory

The DELFIA PCB Assay is a solid-phase time-resolved fluoroimmunoassay based on the sequential addition of sample extract and europium-labeled PCB tracer to a monoclonal antibody reagent specific for PCBs. In this assay, the antibody reagent and sample extract are added to a strip...

Improving the Energy Market: Algorithms, Market Implications, and Transmission Switching

NASA Astrophysics Data System (ADS)

Lipka, Paula Ann

This dissertation aims to improve ISO operations through a better real-time market solution algorithm that directly considers both real and reactive power, finds a feasible Alternating Current Optimal Power Flow solution, and allows for solving transmission switching problems in an AC setting. Most of the IEEE systems do not contain any thermal limits on lines, and the ones that do are often not binding. Chapter 3 modifies the thermal limits for the IEEE systems to create new, interesting test cases. Algorithms created to better solve the power flow problem often solve the IEEE cases without line limits. However, one of the factors that makes the power flow problem hard is thermal limits on the lines. The transmission networks in practice often have transmission lines that become congested, and it is unrealistic to ignore line limits. Modifying the IEEE test cases makes it possible for other researchers to be able to test their algorithms on a setup that is closer to the actual ISO setup. This thesis also examines how to convert limits given on apparent power---as is in the case in the Polish test systems---to limits on current. The main consideration in setting line limits is temperature, which linearly relates to current. Setting limits on real or apparent power is actually a proxy for using the limits on current. Therefore, Chapter 3 shows how to convert back to the best physical representation of line limits. A sequential linearization of the current-voltage formulation of the Alternating Current Optimal Power Flow (ACOPF) problem is used to find an AC-feasible generator dispatch. In this sequential linearization, there are parameters that are set to the previous optimal solution. Additionally, to improve accuracy of the Taylor series approximations that are used, the movement of the voltage is restricted. The movement of the voltage is allowed to be very large at the first iteration and is restricted further on each subsequent iteration, with the restriction corresponding to the accuracy and AC-feasiblity of the solution. This linearization was tested on the IEEE and Polish systems, which range from 14 to 3375 buses and 20 to 4161 transmission lines. It had an accuracy of 0.5% or less for all but the 30-bus system. It also solved in linear time with CPLEX, while the non-linear version solved in O(n1.11) to O(n1.39). The sequential linearization is slower than the nonlinear formulation for smaller problems, but faster for larger problems, and its linear computational time means it would continue solving faster for larger problems. A major consideration to implementing algorithms to solve the optimal generator dispatch is ensuring that the resulting prices from the algorithm will support the market. Since the sequential linearization is linear, it is convex, its marginal values are well-defined, and there is no duality gap. The prices and settlements obtained from the sequential linearization therefore can be used to run a market. This market will include extra prices and settlements for reactive power and voltage, compared to the present-day market, which is based on real power. An advantage of this is that there is a very clear pool that can be used for reactive power/voltage support payments, while presently there is not a clear pool to take them out of. This method also reveals how valuable reactive power and voltage are at different locations, which can enable better planning of reactive resource construction. Transmission switching increases the feasible region of the generator dispatch, which means there may be a better solution than without transmission switching. Power flows on transmission lines are not directly controllable; rather, the power flows according to how it is injected and the physical characteristics of the lines. Changing the network topology changes the physical characteristics, which changes the flows. This means that sets of generator dispatch that may have previously been infeasible due to the flow exceeding line constraints may be feasible, since the flows will be different and may meet line constraints. However, transmission switching is a mixed integer problem, which may have a very slow solution time. For economic switching, we examine a series of heuristics. We examine the congestion rent heuristic in detail and then examine many other heuristics at a higher level. Post-contingency corrective switching aims to fix issues in the power network after a line or generator outage. In Chapter 7, we show that using the sequential linear program with corrective switching helps solve voltage and excessive flow issues. (Abstract shortened by UMI.).

Fractionation of enzymatic hydrolysis lignin by sequential extraction for enhancing antioxidant performance.

PubMed

An, Liangliang; Wang, Guanhua; Jia, Hongyu; Liu, Cuiyun; Sui, Wenjie; Si, Chuanling

2017-06-01

The heterogeneity of lignin chemical structure and molecular weight results in the lignin inhomogeneous properties which also covers the antioxidant performance. In order to evaluate the effects of lignin heterogeneity on its antioxidant activity, four lignin fractions from enzymatic hydrolysis lignin were classified by sequential organic solvent extraction and further evaluated by DPPH (1,1-Diphenyl-2-Picrylhydrazyl) free radical scavenging capacity and reducing power analysis. The characterization including FTIR, 1 H NMR and GPC showed that the fractionation process could effectively separate lignin fractions with distinctly different molecular weight and weaken the heterogeneity of unfractionated lignin. The antioxidant performance comparison of lignin fractions indicated that the dichloromethane fraction (F1) with lowest molecular weight (4585g/mol) and highest total phenolics content (246.13mg GAE/g) exhibited the highest antioxidant activity whose value was close to commercial antioxidant BHT (butylated hydroxytoluene). Moreover, the relationship between the antioxidant activity and the structure of lignin was further discussed to elucidate the mechanism of antioxidant activity improvement of lignin fractionation. Consequently, this study suggested that the sequential extraction was an effective way to obtain relatively homogeneous enzymatic hydrolysis lignin fractions which showed the potential for the value-added antioxidant application. Copyright © 2017 Elsevier B.V. All rights reserved.

Combination of HPLC chromatogram and hypoglycemic effect identifies isoflavones as the principal active fraction of Belamcanda chinensis leaf extract in diabetes treatment.

PubMed

Chen, Yan; Wu, Chong-Ming; Dai, Rong-Ji; Li, Liang; Yu, Yu-Hong; Li, Yan; Meng, Wei-Wei; Zhang, Liang; Zhang, Yongqian; Deng, Yu-Lin

2011-02-15

In previous study, we demonstrated the hypoglycemic effect of aqueous extract of Belamcanda chinensis leaves in rats. Here, we separated the aqueous extract of B. chinensis leaves and investigated the spectrum-effect relationships between HPLC chromatograms and hypoglycemic activities of different isolates from B. chinensis leaf extract. Sequential solvent extraction with petroleum ether, chloroform, acetic ester and n-butanol provided several isolates showing similar hypoglycemic activities, making it difficult to discriminate the active fractions. Stepwise elution through HP20 macroporous resin by water, 40% and 95% ethanol provided isolates with distinct hypoglycemic activities, representing a simple, rapid and efficient preparative separation method. Combination of HPLC chromatogram and pharmacological effect targeted a hypoglycemic activity-related region in HPLC chromatogram. Each peak in this region was analyzed by UV spectrum scan. Most of them were flavonoids in which tectoridin and swertisin were known flavonoids with anti-diabetic activities. In together, this work provides a general model of combination of HPLC chromatography and pharmacological effect to study the spectrum-effect relationships of aqueous extract from B. chinensis leaves, which can be used to find principle components of B. chinensis on pharmacological activity. Copyright © 2011 Elsevier B.V. All rights reserved.

Evaluating Snow Data Assimilation Framework for Streamflow Forecasting Applications Using Hindcast Verification

NASA Astrophysics Data System (ADS)

Barik, M. G.; Hogue, T. S.; Franz, K. J.; He, M.

2012-12-01

Snow water equivalent (SWE) estimation is a key factor in producing reliable streamflow simulations and forecasts in snow dominated areas. However, measuring or predicting SWE has significant uncertainty. Sequential data assimilation, which updates states using both observed and modeled data based on error estimation, has been shown to reduce streamflow simulation errors but has had limited testing for forecasting applications. In the current study, a snow data assimilation framework integrated with the National Weather System River Forecasting System (NWSRFS) is evaluated for use in ensemble streamflow prediction (ESP). Seasonal water supply ESP hindcasts are generated for the North Fork of the American River Basin (NFARB) in northern California. Parameter sets from the California Nevada River Forecast Center (CNRFC), the Differential Evolution Adaptive Metropolis (DREAM) algorithm and the Multistep Automated Calibration Scheme (MACS) are tested both with and without sequential data assimilation. The traditional ESP method considers uncertainty in future climate conditions using historical temperature and precipitation time series to generate future streamflow scenarios conditioned on the current basin state. We include data uncertainty analysis in the forecasting framework through the DREAM-based parameter set which is part of a recently developed Integrated Uncertainty and Ensemble-based data Assimilation framework (ICEA). Extensive verification of all tested approaches is undertaken using traditional forecast verification measures, including root mean square error (RMSE), Nash-Sutcliffe efficiency coefficient (NSE), volumetric bias, joint distribution, rank probability score (RPS), and discrimination and reliability plots. In comparison to the RFC parameters, the DREAM and MACS sets show significant improvement in volumetric bias in flow. Use of assimilation improves hindcasts of higher flows but does not significantly improve performance in the mid flow and low flow categories.

Manganese speciation of laboratory-generated welding fumes

PubMed Central

Andrews, Ronnee N.; Keane, Michael; Hanley, Kevin W.; Feng, H. Amy; Ashley, Kevin

2015-01-01

The objective of this laboratory study was to identify and measure manganese (Mn) fractions in chamber-generated welding fumes (WF) and to evaluate and compare the results from a sequential extraction procedure for Mn fractions with that of an acid digestion procedure for measurement of total, elemental Mn. To prepare Mn-containing particulate matter from representative welding processes, a welding system was operated in short circuit gas metal arc welding (GMAW) mode using both stainless steel (SS) and mild carbon steel (MCS) and also with flux cored arc welding (FCAW) and shielded metal arc welding (SMAW) using MCS. Generated WF samples were collected onto polycarbonate filters before homogenization, weighing and storage in scintillation vials. The extraction procedure consisted of four sequential steps to measure various Mn fractions based upon selective solubility: (1) soluble Mn dissolved in 0.01 M ammonium acetate; (2) Mn (0,II) dissolved in 25 % (v/v) acetic acid; (3) Mn (III,IV) dissolved in 0.5% (w/v) hydroxylamine hydrochloride in 25% (v/v) acetic acid; and (4) insoluble Mn extracted with concentrated hydrochloric and nitric acids. After sample treatment, the four fractions were analyzed for Mn by inductively coupled plasma-atomic emission spectroscopy (ICP-AES). WF from GMAW and FCAW showed similar distributions of Mn species, with the largest concentrations of Mn detected in the Mn (0,II) and insoluble Mn fractions. On the other hand, the majority of the Mn content of SMAW fume was detected as Mn (III,IV). Although the concentration of Mn measured from summation of the four sequential steps was statistically significantly different from that measured from the hot block dissolution method for total Mn, the difference is small enough to be of no practical importance for industrial hygiene air samples, and either method may be used for Mn measurement. The sequential extraction method provides valuable information about the oxidation state of Mn in samples and allows for comparison to results from previous work and from total Mn dissolution methods. PMID:26345630

Manganese speciation of laboratory-generated welding fumes.

PubMed

Andrews, Ronnee N; Keane, Michael; Hanley, Kevin W; Feng, H Amy; Ashley, Kevin

The objective of this laboratory study was to identify and measure manganese (Mn) fractions in chamber-generated welding fumes (WF) and to evaluate and compare the results from a sequential extraction procedure for Mn fractions with that of an acid digestion procedure for measurement of total, elemental Mn. To prepare Mn-containing particulate matter from representative welding processes, a welding system was operated in short circuit gas metal arc welding (GMAW) mode using both stainless steel (SS) and mild carbon steel (MCS) and also with flux cored arc welding (FCAW) and shielded metal arc welding (SMAW) using MCS. Generated WF samples were collected onto polycarbonate filters before homogenization, weighing and storage in scintillation vials. The extraction procedure consisted of four sequential steps to measure various Mn fractions based upon selective solubility: (1) soluble Mn dissolved in 0.01 M ammonium acetate; (2) Mn (0,II) dissolved in 25 % (v/v) acetic acid; (3) Mn (III,IV) dissolved in 0.5% (w/v) hydroxylamine hydrochloride in 25% (v/v) acetic acid; and (4) insoluble Mn extracted with concentrated hydrochloric and nitric acids. After sample treatment, the four fractions were analyzed for Mn by inductively coupled plasma-atomic emission spectroscopy (ICP-AES). WF from GMAW and FCAW showed similar distributions of Mn species, with the largest concentrations of Mn detected in the Mn (0,II) and insoluble Mn fractions. On the other hand, the majority of the Mn content of SMAW fume was detected as Mn (III,IV). Although the concentration of Mn measured from summation of the four sequential steps was statistically significantly different from that measured from the hot block dissolution method for total Mn, the difference is small enough to be of no practical importance for industrial hygiene air samples, and either method may be used for Mn measurement. The sequential extraction method provides valuable information about the oxidation state of Mn in samples and allows for comparison to results from previous work and from total Mn dissolution methods.

Extraction of hyaluronic acid (HA) from rooster comb and characterization using flow field-flow fractionation (FlFFF) coupled with multiangle light scattering (MALS).

PubMed

Kang, Dong Young; Kim, Won-Suk; Heo, In Sook; Park, Young Hun; Lee, Seungho

2010-11-01

Hyaluronic acid (HA) was extracted in a relatively large scale from rooster comb using a method similar to that reported previously. The extraction method was modified to simplify and to reduce time and cost in order to accommodate a large-scale extraction. Five hundred grams of frozen rooster combs yielded about 500 mg of dried HA. Extracted HA was characterized using asymmetrical flow field-flow fractionation (AsFlFFF) coupled online to a multiangle light scattering detector and a refractive index detector to determine the molecular size, molecular weight (MW) distribution, and molecular conformation of HA. For characterization of HA, AsFlFFF was operated by a simplified two-step procedure, instead of the conventional three-step procedure, where the first two steps (sample loading and focusing) were combined into one to avoid the adsorption of viscous HA onto the channel membrane. The simplified two-step AsFlFFF yielded reasonably good separations of HA molecules based on their MWs. The weight average MW (M(w) ) and the average root-mean-square (RMS) radius of HA extracted from rooster comb were 1.20×10(6) and 94.7 nm, respectively. When the sample solution was filtered through a 0.45 μm disposable syringe filter, they were reduced down to 3.8×10(5) and 50.1 nm, respectively. Copyright © 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

A method for apportionment of natural and anthropogenic contributions to heavy metal loadings in the surface soils across large-scale regions.

PubMed

Hu, Yuanan; Cheng, Hefa

2016-07-01

Quantification of the contributions from anthropogenic sources to soil heavy metal loadings on regional scales is challenging because of the heterogeneity of soil parent materials and high variability of anthropogenic inputs, especially for the species that are primarily of lithogenic origin. To this end, we developed a novel method for apportioning the contributions of natural and anthropogenic sources by combining sequential extraction and stochastic modeling, and applied it to investigate the heavy metal pollution in the surface soils of the Pearl River Delta (PRD) in southern China. On the average, 45-86% of Zn, Cu, Pb, and Cd were present in the acid soluble, reducible, and oxidizable fractions of the surface soils, while only 12-24% of Ni, Cr, and As were partitioned in these fractions. The anthropogenic contributions to the heavy metals in the non-residual fractions, even the ones dominated by natural sources, could be identified and quantified by conditional inference trees. Combination of sequential extraction, Kriging interpolation, and stochastic modeling reveals that approximately 10, 39, 6.2, 28, 7.1, 15, and 46% of the As, Cd, Cr, Cu, Ni, Pb, and Zn, respectively, in the surface soils of the PRD were contributed by anthropogenic sources. These results were in general agreements with those obtained through subtraction of regional soil metal background from total loadings, and the soil metal inputs through atmospheric deposition as well. In the non-residual fractions of the surface soils, the anthropogenic contributions to As, Cd, Cr, Cu, Ni, Pb, and Zn, were 48, 42, 50, 51, 49, 24, and 70%, respectively. Copyright © 2016 Elsevier Ltd. All rights reserved.

Sequential photocatalyst-assisted digestion and vapor generation device coupled with anion exchange chromatography and inductively coupled plasma mass spectrometry for speciation analysis of selenium species in biological samples.

PubMed

Tsai, Yun-ni; Lin, Cheng-hsing; Hsu, I-hsiang; Sun, Yuh-chang

2014-01-02

We have developed an on-line sequential photocatalyst-assisted digestion and vaporization device (SPADVD), which operates through the nano-TiO2-catalyzed photo-oxidation and reduction of selenium (Se) species, for coupling between anion exchange chromatography (LC) and inductively coupled plasma mass spectrometry (ICP-MS) systems to provide a simple and sensitive hyphenated method for the speciation analysis of Se species without the need for conventional chemical digestion and vaporization techniques. Because our proposed on-line SPADVD allows both organic and inorganic Se species in the column effluent to be converted on-line into volatile Se products, which are then measured directly through ICP-MS, the complexity of the procedure and the probability of contamination arising from the use of additional chemicals are both low. Under the optimized conditions for SPADVD - using 1g of nano-TiO2 per liter, at pH 3, and illuminating for 80 s - we found that Se(IV), Se(VI), and selenomethionine (SeMet) were all converted quantitatively into volatile Se products. In addition, because the digestion and vaporization efficiencies of all the tested selenicals were improved when using our proposed on-line LC/SPADVD/ICP-MS system, the detection limits for Se(IV), Se(VI), and SeMet were all in the nanogram-per-liter range (based on 3σ). A series of validation experiments - analysis of neat and spiked extracted samples - indicated that our proposed methods could be applied satisfactorily to the speciation analysis of organic and inorganic Se species in the extracts of Se-enriched supplements. Copyright © 2013. Published by Elsevier B.V.

Novel full-spectral flow cytometry with multiple spectrally-adjacent fluorescent proteins and fluorochromes and visualization of in vivo cellular movement.

PubMed

Futamura, Koji; Sekino, Masashi; Hata, Akihiro; Ikebuchi, Ryoyo; Nakanishi, Yasutaka; Egawa, Gyohei; Kabashima, Kenji; Watanabe, Takeshi; Furuki, Motohiro; Tomura, Michio

2015-09-01

Flow cytometric analysis with multicolor fluoroprobes is an essential method for detecting biological signatures of cells. Here, we present a new full-spectral flow cytometer (spectral-FCM). Unlike conventional flow cytometer, this spectral-FCM acquires the emitted fluorescence for all probes across the full-spectrum from each cell with 32 channels sequential PMT unit after dispersion with prism, and extracts the signals of each fluoroprobe based on the spectral shape of each fluoroprobe using unique algorithm in high speed, high sensitive, accurate, automatic and real-time. The spectral-FCM detects the continuous changes in emission spectra from green to red of the photoconvertible protein, KikGR with high-spectral resolution and separates spectrally-adjacent fluoroprobes, such as FITC (Emission peak (Em) 519 nm) and EGFP (Em 507 nm). Moreover, the spectral-FCM can measure and subtract autofluorescence of each cell providing increased signal-to-noise ratios and improved resolution of dim samples, which leads to a transformative technology for investigation of single cell state and function. These advances make it possible to perform 11-color fluorescence analysis to visualize movement of multilinage immune cells by using KikGR-expressing mice. Thus, the novel spectral flow cytometry improves the combinational use of spectrally-adjacent various FPs and multicolor fluorochromes in metabolically active cell for the investigation of not only the immune system but also other research and clinical fields of use. © 2015 International Society for Advancement of Cytometry.

Chemically differentiating ascorbate-mediated dissolution of quantum dots in cell culture media

NASA Astrophysics Data System (ADS)

Su, Cheng-Kuan; Sun, Yuh-Chang

2013-02-01

To investigate the dynamic dissolution of quantum dots (QDs) in cell culture media, in this study we constructed an online automatic analytical system comprising a sequential in-tube solid phase extraction (SPE) device and an inductively coupled plasma (ICP) mass spectrometer. By means of selectively extracting QDs and cadmium ions (Cd2+) onto the interior surface of the polytetrafluoroethylene (PTFE) tube, this novel SPE device could be used to determine the degree of QD dissolution through a simple adjustment of sample acidity. To the best of our knowledge, this study is the first to exploit PTFE tubing as a selective SPE adsorbent for the online chemical differentiation of QDs and Cd2+ ions with the goal of monitoring the phenomenon of QD dissolution in complicated biological matrices. We confirmed the analytical reliability of this system through comparison of the measured Cd-to-QD ratios to the expected values. When analyzing QDs and Cd2+ ions at picomolar levels, a temporal resolution of 8 min was required to load sufficient amounts of the analytes to meet the sensitivity requirements of the ICP mass spectrometer. To demonstrate the practicability of this developed method, we measured the dynamic variations in the Cd-to-QD705 ratio in the presence of ascorbate as a physiological stimulant to generate reactive oxygen species in cell culture media and trigger the dissolution of QDs; our results suggest that the ascorbate-induced QD dissolution was dependent on the time, treatment concentration, and nature of the biomolecule.To investigate the dynamic dissolution of quantum dots (QDs) in cell culture media, in this study we constructed an online automatic analytical system comprising a sequential in-tube solid phase extraction (SPE) device and an inductively coupled plasma (ICP) mass spectrometer. By means of selectively extracting QDs and cadmium ions (Cd2+) onto the interior surface of the polytetrafluoroethylene (PTFE) tube, this novel SPE device could be used to determine the degree of QD dissolution through a simple adjustment of sample acidity. To the best of our knowledge, this study is the first to exploit PTFE tubing as a selective SPE adsorbent for the online chemical differentiation of QDs and Cd2+ ions with the goal of monitoring the phenomenon of QD dissolution in complicated biological matrices. We confirmed the analytical reliability of this system through comparison of the measured Cd-to-QD ratios to the expected values. When analyzing QDs and Cd2+ ions at picomolar levels, a temporal resolution of 8 min was required to load sufficient amounts of the analytes to meet the sensitivity requirements of the ICP mass spectrometer. To demonstrate the practicability of this developed method, we measured the dynamic variations in the Cd-to-QD705 ratio in the presence of ascorbate as a physiological stimulant to generate reactive oxygen species in cell culture media and trigger the dissolution of QDs; our results suggest that the ascorbate-induced QD dissolution was dependent on the time, treatment concentration, and nature of the biomolecule. Electronic supplementary information (ESI) available: The operation sequence, optimized parameters, instrumental operation conditions, and schematic representations for the proposed sequential in-tube PTFE SPE-ICP-MS hyphenated system are provided. See DOI: 10.1039/c2nr33365a

Sequential lineups: shift in criterion or decision strategy?

PubMed

Gronlund, Scott D

2004-04-01

R. C. L. Lindsay and G. L. Wells (1985) argued that a sequential lineup enhanced discriminability because it elicited use of an absolute decision strategy. E. B. Ebbesen and H. D. Flowe (2002) argued that a sequential lineup led witnesses to adopt a more conservative response criterion, thereby affecting bias, not discriminability. Height was encoded as absolute (e.g., 6 ft [1.83 m] tall) or relative (e.g., taller than). If a sequential lineup elicited an absolute decision strategy, the principle of transfer-appropriate processing predicted that performance should be best when height was encoded absolutely. Conversely, if a simultaneous lineup elicited a relative decision strategy, performance should be best when height was encoded relatively. The predicted interaction was observed, providing direct evidence for the decision strategies explanation of what happens when witnesses view a sequential lineup.

Noise suppression due to annulus shaping of conventional coaxial nozzle

NASA Technical Reports Server (NTRS)

Vonglahn, U.; Goodykoontz, J.

1980-01-01

A method which shows that increasing the annulus width of a conventional coaxial nozzle with constant bypass velocity will lower the noise level is described. The method entails modifying a concentric coaxial nozzle to provide an eccentric outer stream annulus while maintaining approximately the same through flow as that for the original concentric bypass nozzle. Acoustical tests to determine the noise generating characteristics of the nozzle over a range of flow conditions are described. The tests involved sequentially analyzing the noise signals and digitally recording the 1/3 octave band sound pressure levels. The measurements were made in a plane passing through the minimum and maximum annulus width points, as well as at 90 degrees in this plane, by rotating the outer nozzle about its axis. Representative measured spectral data in the flyover plane for the concentric nozzle obtained at model scale are discussed. Representative spectra for several engine cycles are presented for both the eccentric and concentric nozzles at engine size.

Supercritical Fluid Extraction of Toxic Heavy Metals and Uranium from Acidic Solutions with Sulfur-Containing Organophosphorus Reagents

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lin, Yuehe; Liu, Chongxuan; Wu, Hong

2003-03-02

The feasibility of using sulfur-containing organophosphorus reagents for the chelation-supercritical fluid extraction (SFE) of toxic heavy metals and uranium from acidic media was investigated. The SFE experiments were conducted in a specially-designed flow-through liquid extractor. Effective extraction of the metal ions from various acidic media was demonstrated. The effect of ligand concentration in supercritical CO{sub 2} on the kinetics of metal extraction was studied. A simplified model is used to describe the extraction kinetics and the good agreement of experimental data with the equilibrium-based model is achieved.

Automatic retinal blood flow calculation using spectral domain optical coherence tomography

NASA Astrophysics Data System (ADS)

Wehbe, Hassan; Ruggeri, Marco; Jiao, Shuliang; Gregori, Giovanni; Puliafito, Carmen A.

2008-02-01

Optical Doppler tomography (ODT) is a branch of optical coherence tomography (OCT) that can measure the speed of a blood flow by measuring the Doppler shift impinged on the probing sample light by the moving blood cells. However, the measured speed of blood flow is a function of the Doppler angle, which needs to be determined in order to calculate the absolute velocity of the blood flow inside a vessel. We developed a technique that can extract the Doppler angle from the 3D data measured with spectral-domain OCT, which needs to extract the lateral and depth coordinates of a vessel in each measured ODT and OCT image. The lateral coordinates and the diameter of a blood vessel were first extracted in each OCT structural image by using the technique of blood vessel shadowgram, a technique first developed by us for enhancing the retinal blood vessel contrast in the en face view of the 3D OCT. The depth coordinate of a vessel was then determined by using a circular averaging filter moving in the depth direction along the axis passing through the vessel center in the ODT image. The Doppler angle was then calculated from the extracted coordinates of the blood vessel. The technique was applied in blood flow measurements in retinal blood vessels, which has potential impact on the study and diagnosis of blinding diseases like glaucoma and diabetic retinopathy.

Improved radiocarbon analyses of modern human hair to determine the year-of-death by cross-flow nanofiltered amino acids: common contaminants, implications for isotopic analysis, and recommendations.

PubMed

Santos, Guaciara M; De La Torre, Hector A Martinez; Boudin, Mathieu; Bonafini, Marco; Saverwyns, Steven

2015-10-15

In forensic investigation, radiocarbon ((14)C) measurements of human tissues (i.e., nails and hair) can help determine the year-of-death. However, the frequent use of cosmetics can bias hair (14)C results as well as stable isotope values. Evidence shows that hair exogenous impurities percolate beyond the cuticle layer, and therefore conventional pretreatments are ineffective in removing them. We conducted isotopic analysis ((14)C, δ(13)C, δ(15)N and C/N) of conventionally treated and cross-flow nanofiltered amino acid (CFNAA)-treated samples (scalp- and body-hair) from a single female subject using fingernails as a reference. The subject studied frequently applies a permanent dark-brown dye kit to her scalp-hair and uses other care products for daily cleansing. We also performed pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS) analyses of CFNAA-treated scalp-hair to identify contaminant remnants that could possibly interfere with isotopic analyses. The conventionally treated scalp- and body-hair showed (14)C offsets of ~21‰ and ~9‰, respectively. These offsets confirm the contamination by petrochemicals in modern human hair. A single CFNAA extraction reduced those offsets by ~34%. No significant improvement was observed when sequential extractions were performed, as it appears that the procedure introduced some foreign contaminants. A chromatogram of the CFNAA scalp-hair pyrolysis products showed the presence of petroleum and plant/animal compound residues, which can bias isotopic analyses. We have demonstrated that CFNAA extractions can partially remove cosmetic contaminants embedded in human hair. We conclude that fingernails are still the best source of keratin protein for year-of-death determinations and isotopic analysis, with body-hair and/or scalp-hair coupled with CFNAA extraction a close second. Copyright © 2015 John Wiley & Sons, Ltd.

Fluid extraction across pumping and permeable walls in the viscous limit

NASA Astrophysics Data System (ADS)

Herschlag, G.; Liu, J.-G.; Layton, A. T.

2016-04-01

In biological transport mechanisms such as insect respiration and renal filtration, fluid travels along a leaky channel allowing material exchange with systems exterior to the channel. The channels in these systems may undergo peristaltic pumping which is thought to enhance the material exchange. To date, little analytic work has been done to study the effect of pumping on material extraction across the channel walls. In this paper, we examine a fluid extraction model in which fluid flowing through a leaky channel is exchanged with fluid in a reservoir. The channel walls are allowed to contract and expand uniformly, simulating a pumping mechanism. In order to efficiently determine solutions of the model, we derive a formal power series solution for the Stokes equations in a finite channel with uniformly contracting/expanding permeable walls. This flow has been well studied in the case in which the normal velocity at the channel walls is proportional to the wall velocity. In contrast we do not assume flow that is proportional to the wall velocity, but flow that is driven by hydrostatic pressure, and we use Darcy's law to close our system for normal wall velocity. We incorporate our flow solution into a model that tracks the material pressure exterior to the channel. We use this model to examine flux across the channel-reservoir barrier and demonstrate that pumping can either enhance or impede fluid extraction across channel walls. We find that associated with each set of physical flow and pumping parameters, there are optimal reservoir conditions that maximize the amount of material flowing from the channel into the reservoir.

Comparison of amphiphilic polyurethane nanoparticles to nonionic surfactants for flushing phenanthrene from soil.

PubMed

Kim, Ju-Young; Shim, Sun-Bo; Shim, Jin-Kie

2004-12-31

Amphiphilic polyurethane (APU) nanoparticles were synthesized through crosslinking polymerization of nano-aggregates of urethane acrylate nonionomer (UAN). The efficiency of in situ extraction of sorbed phenanthrene from aquifer material was tested using soil columns and compared with that of surfactants such as Triton X-100, Brij 30, and Tween 80. The extraction efficiency of those washing materials strongly depended on their concentration, flow rate, and the degree of sorption within soil column. That is, the extraction efficiency increased with the decrease of flow rate and the degree of sorption and the increase of the concentration. Even though the surfactants are superior to APU nanoparticles at solubilizing phenanthrene, at the same flow rate (0.02 mL/min) and concentration (4000 mg/L), the effectiveness of in situ soil washing of APU nanoparticles was about two times higher than those of surfactants. This is because, at the lower flow rates, the degree of sorption of APU nanoparticles was lower than that of surfactants, owing to the chemically crosslinked nature of APU nanoparticles.

Distribution and uptake dynamics of mercury in leaves of common deciduous tree species in Minnesota, U.S.A.

Treesearch

Aicam Laacouri; Edward A. Nater; Randall K. Kolka

2013-01-01

A sequential extraction technique for compartmentalizing mercury (Hg) in leaves was developed based on a water extraction of Hg from the leaf surface followed by a solvent extraction of the cuticle. The bulk of leaf Hg was found in the tissue compartment (90-96%) with lesser amounts in the surface and cuticle compartments. Total leaf concentrations of Hg varied among...

Erythrocyte antioxidant protection of rose hips (Rosa spp.).

PubMed

Widén, C; Ekholm, A; Coleman, M D; Renvert, S; Rumpunen, K

2012-01-01

Rose hips are popular in health promoting products as the fruits contain high content of bioactive compounds. The aim of this study was to investigate whether health benefits are attributable to ascorbic acid, phenols, or other rose-hip-derived compounds. Freeze-dried powder of rose hips was preextracted with metaphosphoric acid and the sample was then sequentially eluted on a C(18) column. The degree of amelioration of oxidative damage was determined in an erythrocyte in vitro bioassay by comparing the effects of a reducing agent on erythrocytes alone or on erythrocytes pretreated with berry extracts. The maximum protection against oxidative stress, 59.4 ± 4.0% (mean ± standard deviation), was achieved when incubating the cells with the first eluted meta-phosphoric extract. Removal of ascorbic acid from this extract increased the protection against oxidative stress to 67.9 ± 1.9%. The protection from the 20% and 100% methanol extracts was 20.8 ± 8.2% and 5.0 ± 3.2%, respectively. Antioxidant uptake was confirmed by measurement of catechin by HPLC-ESI-MS in the 20% methanol extract. The fact that all sequentially eluted extracts studied contributed to protective effects on the erythrocytes indicates that rose hips contain a promising level of clinically relevant antioxidant protection.

Using Selective Drainage Methods to Extract Continuous Surface Flow from 1-Meter Lidar-Derived Digital Elevation Data

USGS Publications Warehouse

Poppenga, Sandra K.; Worstell, Bruce B.; Stoker, Jason M.; Greenlee, Susan K.

2010-01-01

Digital elevation data commonly are used to extract surface flow features. One source for high-resolution elevation data is light detection and ranging (lidar). Lidar can capture a vast amount of topographic detail because of its fine-scale ability to digitally capture the surface of the earth. Because elevation is a key factor in extracting surface flow features, high-resolution lidar-derived digital elevation models (DEMs) provide the detail needed to consistently integrate hydrography with elevation, land cover, structures, and other geospatial features. The U.S. Geological Survey has developed selective drainage methods to extract continuous surface flow from high-resolution lidar-derived digital elevation data. The lidar-derived continuous surface flow network contains valuable information for water resource management involving flood hazard mapping, flood inundation, and coastal erosion. DEMs used in hydrologic applications typically are processed to remove depressions by filling them. High-resolution DEMs derived from lidar can capture much more detail of the land surface than courser elevation data. Therefore, high-resolution DEMs contain more depressions because of obstructions such as roads, railroads, and other elevated structures. The filling of these depressions can significantly affect the DEM-derived surface flow routing and terrain characteristics in an adverse way. In this report, selective draining methods that modify the elevation surface to drain a depression through an obstruction are presented. If such obstructions are not removed from the elevation data, the filling of depressions to create continuous surface flow can cause the flow to spill over an obstruction in the wrong location. Using this modified elevation surface improves the quality of derived surface flow and retains more of the true surface characteristics by correcting large filled depressions. A reliable flow surface is necessary for deriving a consistently connected drainage network, which is important in understanding surface water movement and developing applications for surface water runoff, flood inundation, and erosion. Improved methods are needed to extract continuous surface flow features from high-resolution elevation data based on lidar.

Quantitative Analysis of Intracellular Motility Based on Optical Flow Model

PubMed Central

Li, Heng

2017-01-01

Analysis of cell mobility is a key issue for abnormality identification and classification in cell biology research. However, since cell deformation induced by various biological processes is random and cell protrusion is irregular, it is difficult to measure cell morphology and motility in microscopic images. To address this dilemma, we propose an improved variation optical flow model for quantitative analysis of intracellular motility, which not only extracts intracellular motion fields effectively but also deals with optical flow computation problem at the border by taking advantages of the formulation based on L1 and L2 norm, respectively. In the energy functional of our proposed optical flow model, the data term is in the form of L2 norm; the smoothness of the data changes with regional features through an adaptive parameter, using L1 norm near the edge of the cell and L2 norm away from the edge. We further extract histograms of oriented optical flow (HOOF) after optical flow field of intracellular motion is computed. Then distances of different HOOFs are calculated as the intracellular motion features to grade the intracellular motion. Experimental results show that the features extracted from HOOFs provide new insights into the relationship between the cell motility and the special pathological conditions. PMID:29065574

Economic Analysis of an Integrated Annatto Seeds-Sugarcane Biorefinery Using Supercritical CO2 Extraction as a First Step

PubMed Central

Albarelli, Juliana Q.; Santos, Diego T.; Cocero, María José; Meireles, M. Angela A.

2016-01-01

Recently, supercritical fluid extraction (SFE) has been indicated to be utilized as part of a biorefinery, rather than as a stand-alone technology, since besides extracting added value compounds selectively it has been shown to have a positive effect on the downstream processing of biomass. To this extent, this work evaluates economically the encouraging experimental results regarding the use of SFE during annatto seeds valorization. Additionally, other features were discussed such as the benefits of enhancing the bioactive compounds concentration through physical processes and of integrating the proposed annatto seeds biorefinery to a hypothetical sugarcane biorefinery, which produces its essential inputs, e.g., CO2, ethanol, heat and electricity. For this, first, different configurations were modeled and simulated using the commercial simulator Aspen Plus® to determine the mass and energy balances. Next, each configuration was economically assessed using MATLAB. SFE proved to be decisive to the economic feasibility of the proposed annatto seeds-sugarcane biorefinery concept. SFE pretreatment associated with sequential fine particles separation process enabled higher bixin-rich extract production using low-pressure solvent extraction method employing ethanol, meanwhile tocotrienols-rich extract is obtained as a first product. Nevertheless, the economic evaluation showed that increasing tocotrienols-rich extract production has a more pronounced positive impact on the economic viability of the concept. PMID:28773616

A novel approach to flow estimation in tidal rivers

NASA Astrophysics Data System (ADS)

Moftakhari, H. R.; Jay, D. A.; Talke, S. A.; Kukulka, T.; Bromirski, P. D.

2013-08-01

Reliable estimation of river discharge to the ocean from large tidal rivers is vital for water resources management and climate analyses. Due to the difficulties inherent in measuring tidal-river discharge, flow records are often limited in length and/or quality and tidal records often predate discharge records. Tidal theory indicates that tides and river discharge interact through quadratic bed friction, which diminishes and distorts the tidal wave as discharge increases. We use this phenomenon to develop a method of estimating river discharge for time periods with tidal data but no flow record. Employing sequential 32 day harmonic analyses of tidal properties, we calibrate San Francisco (SF), CA tide data to the Sacramento River delta outflow index from 1930 to 1990, and use the resulting relationship to hindcast river flow from 1858 to 1929. The M2 admittance (a ratio of the observed M2 tidal constituent to its astronomical forcing) best reproduces high flows, while low-flow periods are better represented by amplitude ratios based on higher harmonics (e.g.,M4/M22). Results show that the annual inflow to SF Bay is now 30% less than before 1900 and confirm that the flood of January 1862 was the largest since 1858.

Sequential microwave superheated water extraction of mannans from spent coffee grounds.

PubMed

Passos, Cláudia P; Moreira, Ana S P; Domingues, M Rosário M; Evtuguin, Dmitry V; Coimbra, Manuel A

2014-03-15

The feasibility of using sequential microwave superheated water extraction (MAE) for the recovery of mannans from spent coffee grounds (SCG) was studied. Due to the high contents of mannose still present in the SCG residue left after two consecutive MAE, the unextracted material was re-suspended in water and submitted to a third microwave irradiation (MAE3) at 200 °C for 3 min. With MAE3, mannose recovery achieved 48%, increasing to 56% by MAE4, and reaching a maximum of 69% with MAE5. Glycosidic-linkage analysis showed that in MAE3 mainly galactomannans were recovered, while debranched galactomannans were recovered with MAE4 and MAE5. With increasing the number of extractions, the average degree of polymerization of the mannans decreased, as observed by size-exclusion chromatography and by methylation analysis. Scanning electron microscopy images showed a decrease on cell walls thickness. After final MAE5, the remaining un-extracted insoluble material, representing 22% of the initial SCG, was composed mainly by cellulose (84%). Copyright © 2013 Elsevier Ltd. All rights reserved.

Heavy metal extractable forms in sludge from wastewater treatment plants.

PubMed

Alvarez, E Alonso; Mochón, M Callejón; Jiménez Sánchez, J C; Ternero Rodríguez, M

2002-05-01

The analysis of heavy metals is a very important task to assess the potential environmental and health risk associated with the sludge coming from wastewater treatment plants (WWTPs). However, it is widely accepted that the determination of total elements does not give an accurate estimation of the potential environmental impact. So, it is necessary to apply sequential extraction techniques to obtain a suitable information about their bioavailability or toxicity. In this paper, a sequential extraction scheme according to the BCR's guidelines was applied to sludge samples collected from each sludge treatment step of five municipal activated sludge plants. Al. Cd, Co, Cu, Cr, Fe, Mn, Hg, Mo, Ni, Pb, Ti and Zn were determined in the sludge extracts by inductively coupled plasma atomic emission spectrometry. In relation to current international legislation for the use of sludge for agricultural purposes none of metal concentrations exceeded maximum permitted levels. In most of the metal elements under considerations, results showed a clear rise along the sludge treatment in the proportion of two less-available fractions (oxidizable metal and residual metal).

Zero Gravity Cryogenic Vent System Concepts for Upper Stages

NASA Technical Reports Server (NTRS)

Flachbart, Robin H.; Holt, James B.; Hastings, Leon J.

2001-01-01

The capability to vent in zero gravity without resettling is a technology need that involves practically all uses of sub-critical cryogenics in space, and would extend cryogenic orbital transfer vehicle capabilities. However, the lack of definition regarding liquid/ullage orientation coupled with the somewhat random nature of the thermal stratification and resulting pressure rise rates, lead to significant technical challenges. Typically a zero gravity vent concept, termed a thermodynamic vent system (TVS), consists of a tank mixer to destratify the propellant, combined with a Joule-Thomson (J-T) valve to extract thermal energy from the propellant. Marshall Space Flight Center's (MSFC's) Multipurpose Hydrogen Test Bed (MHTB) was used to test both spray-bar and axial jet TVS concepts. The axial jet system consists of a recirculation pump heat exchanger unit. The spray-bar system consists of a recirculation pump, a parallel flow concentric tube heat exchanger, and a spray-bar positioned close to the longitudinal axis of the tank. The operation of both concepts is similar. In the mixing mode, the recirculation pump withdraws liquid from the tank and sprays it into the tank liquid, ullage, and exposed tank surfaces. When energy extraction is required, a small portion of the recirculated liquid is passed sequentially through the J-T expansion valve, the heat exchanger, and is vented overboard. The vented vapor cools the circulated bulk fluid, thereby removing thermal energy and reducing tank pressure. The pump operates alone, cycling on and off, to destratify the tank liquid and ullage until the liquid vapor pressure reaches the lower set point. At that point, the J-T valve begins to cycle on and off with the pump. Thus, for short duration missions, only the mixer may operate, thus minimizing or even eliminating boil-off losses.

Sustainable Diagnostic Tools for Site Characterization and Remediation

NASA Astrophysics Data System (ADS)

Driver, E. M.; Roll, I. B.; Supowit, S. D.; Halden, R. U.

2016-12-01

Three submersible diagnostic tools were developed to enable more precise and cost-effective means of sampling environmental waters and assessing remedial strategies. The In Situ Sampler (IS2) and In Situ Sampler for Biphasic Water Monitoring (IS2B), designed for sampling groundwater or simultaneous pore- and surface water, use affordable off-the-shelf solid phase extraction technology, applicable to a broad range of organic and inorganic contaminants. Flow-through design reduces hazardous waste generation, transportation costs, and carbon footprint by 90-98% compared to traditional methods. The IS2 is ideal for dynamic groundwater systems where discrete sampling may fail to capture temporal variations, leading to inaccurate assessment of exposure and risk. A 28-day sampling event in a Cr(VI)-impacted aquifer captured previously undetected tidally-induced fluctuations, while improving the reporting limit 8-fold. The IS2B elucidates contaminant partitioning and bioavailability, and was validated in a wetland-shallow aquifer system with the pesticide fipronil. Concentrations of total fipronil-related compounds were statistically indistinguishable from those determined by conventional techniques (p > 0.2), ranging from 9.9 ± 4.6 to 18.1 ± 4.6 ng/L in surface water and 9.1 ± 3.0 to 12.6 ± 2.1 ng/L in porewater. For groundwater remedial testing, the In Situ Microcosm Array (ISMA) was developed to integrate laboratory column treatability studies with pilot-scale field-testing, thus minimizing costs associated with sequential lab and field analyses. In situ operation maintains (geo)chemical and microbial groundwater parameters often destroyed by extraction and laboratory storage. Onboard effluent capture permits the deployment well to return to monitoring status immediately after instrument removal. All tools employ reusable internal components and may be operated by solar power. Case study results highlight the capabilities and application range of the each technology.

Selenium stable isotope ratios in California agricultural drainage water management systems

USGS Publications Warehouse

Herbel, M.J.; Johnson, T.M.; Tanji, K.K.; Gao, S.; Bullen, T.D.

2002-01-01

Selenium stable isotope ratios are known to shift in predictable ways during various microbial, chemical, and biological processes, and can be used to better understand Se cycling in contaminated environments. In this study we used Se stable isotopes to discern the mechanisms controlling the transformation of oxidized, aqueous forms of Se to reduced, insoluble forms in sediments of Se-affected environments. We measured 80Se/76Se in surface waters, shallow ground waters, evaporites, digested plants and sediments, and sequential extracts from several sites where agricultural drainage water is processed in the San Joaquin Valley of California. Selenium isotope analyses of samples obtained from the Tulare Lake Drainage District flow-through wetland reveal small isotopic contrasts (mean difference 0.7%o) between surface water and reduced Se species in the underlying sediments. Selenium in aquatic macrophytes was very similar isotopically to the NaOH and Na2SO3 sediment extracts designed to recover soluble organic Se and Se(O), respectively. For the integrated on-farm drainage management sites, evaporite salts were slightly (approximately 0.6%o) enriched in the heavier isotope relative to the inferred parent waters, whereas surface soils were slightly (approximately 1.4%o) depleted. Bacterial or chemical reduction of Se(VI) or Se(IV) may be occurring at these sites, but the small isotopic contrasts suggest that other, less isotopically fractionating mechanisms are responsible for accumulation of reduced forms in the sediments. These findings provide evidence that Se assimilation by plants and algae followed by deposition and mineralization is the dominant transformation pathway responsible for accumulation of reduced forms of Se in the wetland sediments.

Phospholipid analysis and fractional reconstitution of the ice nucleation protein activity purified from Escherichia coli overexpressing the inaZ gene of Pseudomonas syringae.

PubMed

Palaiomylitou, M A; Kalimanis, A; Koukkou, A I; Drainas, C; Anastassopoulos, E; Panopoulos, N J; Ekateriniadou, L V; Kyriakidis, D A

1998-08-01

Ice nucleation protein was partially purified from the membrane fraction of E. coli carrying inaZ from Pseudomonas syringae. The ice nucleation protein was totally localized in the bacterial envelope and was extracted by either salt (0.25 M NH4Cl) or the nonionic detergent Tween 20. The extracted protein was partially purified by sequential passage through DEAE-52 cellulose and Sephacryl-S400 columns. The activity of the purified protein was lost after treatment with phospholipase C, and its activity was subsequently restored by addition of the naturally occurring lipid phosphatidylethanolamine. These results suggest that ice nucleation proteins have a requirement for lipids that reconstitute a physiological hydrophobic environment similar to the one existing in vivo, to attain and maintain a structure that enables ice catalysis. Copyright 1998 Academic Press.

Recent Electrochemical and Optical Sensors in Flow-Based Analysis

PubMed Central

Chailapakul, Orawon; Ngamukot, Passapol; Yoosamran, Alongkorn; Siangproh, Weena; Wangfuengkanagul, Nattakarn

2006-01-01

Some recent analytical sensors based on electrochemical and optical detection coupled with different flow techniques have been chosen in this overview. A brief description of fundamental concepts and applications of each flow technique, such as flow injection analysis (FIA), sequential injection analysis (SIA), all injection analysis (AIA), batch injection analysis (BIA), multicommutated FIA (MCFIA), multisyringe FIA (MSFIA), and multipumped FIA (MPFIA) were reviewed.

A comparison study on detection of key geochemical variables and factors through three different types of factor analysis

NASA Astrophysics Data System (ADS)

Hoseinzade, Zohre; Mokhtari, Ahmad Reza

2017-10-01

Large numbers of variables have been measured to explain different phenomena. Factor analysis has widely been used in order to reduce the dimension of datasets. Additionally, the technique has been employed to highlight underlying factors hidden in a complex system. As geochemical studies benefit from multivariate assays, application of this method is widespread in geochemistry. However, the conventional protocols in implementing factor analysis have some drawbacks in spite of their advantages. In the present study, a geochemical dataset including 804 soil samples collected from a mining area in central Iran in order to search for MVT type Pb-Zn deposits was considered to outline geochemical analysis through various fractal methods. Routine factor analysis, sequential factor analysis, and staged factor analysis were applied to the dataset after opening the data with (additive logratio) alr-transformation to extract mineralization factor in the dataset. A comparison between these methods indicated that sequential factor analysis has more clearly revealed MVT paragenesis elements in surface samples with nearly 50% variation in F1. In addition, staged factor analysis has given acceptable results while it is easy to practice. It could detect mineralization related elements while larger factor loadings are given to these elements resulting in better pronunciation of mineralization.

Recurrent flow analysis in spatiotemporally chaotic 2-dimensional Kolmogorov flow

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lucas, Dan, E-mail: dan.lucas@ucd.ie; Kerswell, Rich R., E-mail: r.r.kerswell@bris.ac.uk

2015-04-15

Motivated by recent success in the dynamical systems approach to transitional flow, we study the efficiency and effectiveness of extracting simple invariant sets (recurrent flows) directly from chaotic/turbulent flows and the potential of these sets for providing predictions of certain statistics of the flow. Two-dimensional Kolmogorov flow (the 2D Navier-Stokes equations with a sinusoidal body force) is studied both over a square [0, 2π]{sup 2} torus and a rectangular torus extended in the forcing direction. In the former case, an order of magnitude more recurrent flows are found than previously [G. J. Chandler and R. R. Kerswell, “Invariant recurrent solutionsmore » embedded in a turbulent two-dimensional Kolmogorov flow,” J. Fluid Mech. 722, 554–595 (2013)] and shown to give improved predictions for the dissipation and energy pdfs of the chaos via periodic orbit theory. Analysis of the recurrent flows shows that the energy is largely trapped in the smallest wavenumbers through a combination of the inverse cascade process and a feature of the advective nonlinearity in 2D. Over the extended torus at low forcing amplitudes, some extracted states mimic the statistics of the spatially localised chaos present surprisingly well recalling the findings of Kawahara and Kida [“Periodic motion embedded in plane Couette turbulence: Regeneration cycle and burst,” J. Fluid Mech. 449, 291 (2001)] in low-Reynolds-number plane Couette flow. At higher forcing amplitudes, however, success is limited highlighting the increased dimensionality of the chaos and the need for larger data sets. Algorithmic developments to improve the extraction procedure are discussed.« less

In situ epoxide generation by dimethyldioxirane oxidation and the use of epichlorohydrin in the flow synthesis of a library of β-amino alcohols.

PubMed

Cossar, Peter J; Baker, Jennifer R; Cain, Nicholas; McCluskey, Adam

2018-04-01

The flow coupling of epichlorohydrin with substituted phenols, while efficient, limits the nature of the epoxide available for the development of focused libraries of β-amino alcohols. This limitation was encountered in the production of analogues of 1-(4-nitrophenoxy)-3-((2-((4-(trifluoromethyl)pyrimidin-2-yl)amino)ethyl)amino)propan-2-ol 1 , a potential antibiotic lead. The in situ (flow) generation of dimethyldoxirane (DMDO) and subsequent flow olefin epoxidation abrogates this limitation and afforded facile access to structurally diverse β-amino alcohols. Analogues of 1 were readily accessed either via (i) a flow/microwave hybrid approach, or (ii) a sequential flow approach. Key steps were the in situ generation of DMDO, with olefin epoxidation in typically good yields and a flow-mediated ring opening aminolysis to form an expanded library of β-amino alcohols 1 and 10a - 18g , resulting in modest ( 11a , 21%) to excellent ( 12g , 80%) yields. Alternatively flow coupling of epichlorohydrin with phenols 4a - 4m (22%-89%) and a Bi(OTf) 3 catalysed microwave ring opening with amines afforded a select range of β-amino alcohols, but with lower levels of aminolysis regiocontrol than the sequential flow approach.

In situ epoxide generation by dimethyldioxirane oxidation and the use of epichlorohydrin in the flow synthesis of a library of β-amino alcohols

PubMed Central

Cossar, Peter J.; Baker, Jennifer R.; Cain, Nicholas

2018-01-01

The flow coupling of epichlorohydrin with substituted phenols, while efficient, limits the nature of the epoxide available for the development of focused libraries of β-amino alcohols. This limitation was encountered in the production of analogues of 1-(4-nitrophenoxy)-3-((2-((4-(trifluoromethyl)pyrimidin-2-yl)amino)ethyl)amino)propan-2-ol 1, a potential antibiotic lead. The in situ (flow) generation of dimethyldoxirane (DMDO) and subsequent flow olefin epoxidation abrogates this limitation and afforded facile access to structurally diverse β-amino alcohols. Analogues of 1 were readily accessed either via (i) a flow/microwave hybrid approach, or (ii) a sequential flow approach. Key steps were the in situ generation of DMDO, with olefin epoxidation in typically good yields and a flow-mediated ring opening aminolysis to form an expanded library of β-amino alcohols 1 and 10a–18g, resulting in modest (11a, 21%) to excellent (12g, 80%) yields. Alternatively flow coupling of epichlorohydrin with phenols 4a–4m (22%–89%) and a Bi(OTf)3 catalysed microwave ring opening with amines afforded a select range of β-amino alcohols, but with lower levels of aminolysis regiocontrol than the sequential flow approach. PMID:29765627

THC-MP: High performance numerical simulation of reactive transport and multiphase flow in porous media

NASA Astrophysics Data System (ADS)

Wei, Xiaohui; Li, Weishan; Tian, Hailong; Li, Hongliang; Xu, Haixiao; Xu, Tianfu

2015-07-01

The numerical simulation of multiphase flow and reactive transport in the porous media on complex subsurface problem is a computationally intensive application. To meet the increasingly computational requirements, this paper presents a parallel computing method and architecture. Derived from TOUGHREACT that is a well-established code for simulating subsurface multi-phase flow and reactive transport problems, we developed a high performance computing THC-MP based on massive parallel computer, which extends greatly on the computational capability for the original code. The domain decomposition method was applied to the coupled numerical computing procedure in the THC-MP. We designed the distributed data structure, implemented the data initialization and exchange between the computing nodes and the core solving module using the hybrid parallel iterative and direct solver. Numerical accuracy of the THC-MP was verified through a CO2 injection-induced reactive transport problem by comparing the results obtained from the parallel computing and sequential computing (original code). Execution efficiency and code scalability were examined through field scale carbon sequestration applications on the multicore cluster. The results demonstrate successfully the enhanced performance using the THC-MP on parallel computing facilities.

Geochemical fractionation of metals and metalloids in tailings and appraisal of environmental pollution in the abandoned Musina Copper Mine, South Africa.

PubMed

Gitari, M W; Akinyemi, S A; Ramugondo, L; Matidza, M; Mhlongo, S E

2018-04-30

The economic benefits of mining industry have often overshadowed the serious challenges posed to the environments through huge volume of tailings generated and disposed in tailings dumps. Some of these challenges include the surface and groundwater contamination, dust, and inability to utilize the land for developmental purposes. The abandoned copper mine tailings in Musina (Limpopo province, South Africa) was investigated for particle size distribution, mineralogy, physicochemical properties using arrays of granulometric, X-ray diffraction, and X-ray fluorescence analyses. A modified Community Bureau of Reference (BCR) sequential chemical extraction method followed by inductively coupled plasma mass spectrometry/atomic emission spectrometry (ICP-MS/AES) technique was employed to assess bioavailability of metals. Principal component analysis was performed on the sequential extraction data to reveal different loadings and mobilities of metals in samples collected at various depths. The pH ranged between 7.5 and 8.5 (average ≈ 8.0) indicating alkaline medium. Samples composed mostly of poorly grated sands (i.e. 50% fine sand) with an average permeability of about 387.6 m/s. Samples have SiO 2 /Al 2 O 3 and Na 2 O/(Al 2 O 3  + SiO 2 ) ratios and low plastic index (i.e. PI ≈ 2.79) suggesting non-plastic and very low dry strength. Major minerals were comprised of quartz, epidote, and chlorite while the order of relative abundance of minerals in minor quantities is plagioclase > muscovite > hornblende > calcite > haematite. The largest percentage of elements such as As, Cd and Cr was strongly bound to less extractable fractions. Results showed high concentration and easily extractable Cu in the Musina Copper Mine tailings, which indicates bioavailability and poses environmental risk and potential health risk of human exposure. Principal component analysis revealed Fe-oxide/hydroxides, carbonate and clay components, and copper ore process are controlling the elements distribution.

Extraction of rare earth elements from a contaminated cropland soil using nitric acid, citric acid, and EDTA.

PubMed

Tang, Hailong; Shuai, Weitao; Wang, Xiaojing; Liu, Yangsheng

2017-08-01

Rare earth elements (REEs) contamination to the surrounding soil has increased the concerns of health risk to the local residents. Soil washing was first attempted in our study to remediate REEs-contaminated cropland soil using nitric acid, citric acid, and ethylene diamine tetraacetic acid (EDTA) for soil decontamination and possible recovery of REEs. The extraction time, washing agent concentration, and pH value of the washing solution were optimized. The sequential extraction analysis proposed by Tessier was adopted to study the speciation changes of the REEs before and after soil washing. The extract containing citric acid was dried to obtain solid for the X-ray fluorescence (XRF) analysis. The results revealed that the optimal extraction time was 72 h, and the REEs extraction efficiency increased as the agent concentration increased from 0.01 to 0.1 mol/L. EDTA was efficient to extract REEs over a wide range of pH values, while citric acid was around pH 6.0. Under optimized conditions, the average extraction efficiencies of the major REEs in the contaminated soil were 70.96%, 64.38%, and 62.12% by EDTA, nitric acid, and citric acid, respectively. The sequential extraction analyses revealed that most soil-bounded REEs were mobilized or extracted except for those in the residual fraction. Under a comprehensive consideration of the extraction efficiency and the environmental impact, citric acid was recommended as the most suitable agent for extraction of the REEs from the contaminated cropland soils. The XRF analysis revealed that Mn, Al, Si, Pb, Fe, and REEs were the major elements in the extract indicating a possibile recovery of the REEs.

Zero Gravity Cryogenic Vent System Concepts for Upper Stages

NASA Astrophysics Data System (ADS)

Ravex, Alain; Flachbart, Robin; Holt, Barney

The capability to vent in zero gravity without resettling is a technology need that involves practically all uses of sub-critical cryogenics in space. Venting without resettling would extend cryogenic orbital transfer vehicle capabilities. However, the lack of definition regarding liquid/ullage orientation coupled with the somewhat random nature of the thermal stratification and resulting pressure rise rates, lead to significant technical challenges. Typically a zero gravity vent concept, termed a thermodynamic vent system (TVS), consists of a tank mixer to destratify the propellant, combined with a Joule-Thomson (J-T) valve to extract thermal energy from the propellant. Marshall Space Flight Center's (MSFC's) Multipurpose Hydrogen Test Bed (MHTB) was used to test both spray bar and axial jet TVS concepts. The axial jet system consists of a recirculation pump heat exchanger unit. The spray bar system consists of a recirculation pump, a parallel flow concentric tube, heat exchanger, and a spray bar positioned close to the longitudinal axis of the tank. The operation of both concepts is similar. In the mixing mode, the recirculation pump withdraws liquid from the tank and sprays it into the tank liquid, ullage, and exposed tank surfaces. When energy extraction is required, a small portion of the recirculated liquid is passed sequentially through the J-T expansion valve, the heat exchanger, and is vented overboard. The vented vapor cools the circulated bulk fluid, thereby removing thermal energy and reducing tank pressure. The pump operates alone, cycling on and off, to destratify the tank liquid and ullage until the liquid vapor pressure reaches the lower set point. At that point, the J-T valve begins to cycle on and off with the pump. Thus, for short duration missions, only the mixer may operate, thus minimizing or even eliminating boil-off losses. TVS performance testing demonstrated that the spray bar was effective in providing tank pressure control within a 6.89 kPa (1psi) band for fill levels of 90%, 50%, and 25%. Complete destratification of the liquid and ullage was achieved at these fill levels. The axial jet was effective in providing tank pressure control within the same pressure control band at the 90% fill level. However, at the 50% level, the system reached a point at which it was unable to extract enough energy to keep up with the heat leak into the tank. Due to a hardware problem, the recirculation pump operated well below the axial jet design flow rate. Therefore, it is likely that the performance of the axial jet would have improved had the pump operated at the proper flow rate. A CFD model is being used to determine if the desired axial jet performance would be achieved if a higher pump flow rate were available. Testing conducted thus far has demonstrated that both TVS concepts can be effective in destratifying a propellant tank, rejecting stored heat energy, and thus, controlling tank pressure.

Sequential healing at implants installed immediately into extraction sockets. An experimental study in dogs.

PubMed

Mainetti, Tomaso; Lang, Niklaus P; Bengazi, Franco; Favero, Vittorio; Soto Cantero, Luis; Botticelli, Daniele

2016-01-01

To compare the sequential healing at implants installed in a healed alveolar bony ridge or immediately after tooth extraction without functional load. In the mandible of 12 dogs, the mesial roots of the first molars were endodontically treated, the tooth hemisected, and the distal roots extracted. After 3 months, the mesial roots of the fourth premolars were endodontically treated, the tooth hemisected, and the distal roots extracted in one side of the mandible. Implants were placed immediately into extraction sockets (IPIES) of the fourth premolar and in the healed sites in the molar regions. Healing abutments were placed, and the flaps were sutured to allow a non-submerged healing. The time of surgery and of sacrifices were planned in such a way to obtain biopsies representing the healing after 1 and 2 weeks and 1 and 3 months, respectively. Ground sections were prepared for histological evaluation of tissues components on the implant surface and the coronal termination level of osseointegration (M-B). New bone apposition on the implant surface was slightly higher at the healed compared to the IPIES sites, being 7.4% and 4.1% after 1 week, and 67.3% and 65.3% after 3 months, respectively. Old bone was progressively resorbed, from 27.0% and 21.9% after 1 week, to 2.5% and 2.0% after 3 months, at healed and IPIES sites, respectively. M-B was 1.4 mm and 2.6 mm after 1 week, 1.2 mm and 1.2 mm after 3 months, at healed and IPIES sites, respectively. Similar patterns of sequential osseointegration were found at implants installed in healed alveolar bone or in alveolar sockets immediately after tooth extraction. The coronal termination level of osseointegration, that was different after 1 week, was found similar at the 3-month observation. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Binding characteristics of Cu2+ to natural humic acid fractions sequentially extracted from the lake sediments.

PubMed

He, En; Lü, Changwei; He, Jiang; Zhao, Boyi; Wang, Jinghua; Zhang, Ruiqing; Ding, Tao

2016-11-01

Humic acids (HAs) determine the distribution, toxicity, bioavailability, and ultimate fate of heavy metals in the environment. In this work, ten HA fractions (F1-F10) were used as adsorbent, which were sequentially extracted from natural sediments of Lake Wuliangsuhai, to investigate the binding characteristics of Cu 2+ to HA. On the basis of the characterization results, differences were found between the ten extracted HA fractions responding to their elemental compositions and acidic functional groups. The characterization results reveal that the responses of ten extracted HA fractions to their elemental compositions and acidic functional groups were different. The O/C and (O + N)/C ratio of F1-F8 approximately ranged from 0.66 to 0.53 and from 0.72 to 0.61, respectively; the measured results showed that the contents of phenolic groups and carboxyl groups decreased from 4.46 to 2.60 mmol/g and 1.60 to 0.58 mmol/g, respectively. The binding characteristics of Cu 2+ to the ten HA fractions were well modeled by the bi-Langmuir model; the binding behavior of Cu 2+ to all the ten HA fractions were strongly impacted by pH and ionic strength. The FTIR and SEM-EDX image of HA fractions (pre- and post-adsorption) revealed that carboxyl and phenolic groups were responsible for the Cu 2+ sorption on the ten sequentially extracted HA fractions process, which is the same with the analysis of the ligand binding and bi-Langmuir models Accordingly, the adsorption capacity of the former HA fractions on Cu 2+ were higher than the latter ones, which may be attributed to the difference of carboxyl and phenolic group contents between the former and latter extracted HA fractions. Additionally, the functional groups with N and S should not be neglected. This work is hopeful to understand the environmental effect of humic substances, environmental geochemical behavior, and bioavailability of heavy metals in lakes.

Extraction of long-chain fatty acids in isolated rat heart during acute low-flow ischemia.

PubMed

Richter, W S; Fischer, S; Ernst, N; Munz, D L

2001-07-01

Although beta-oxidation of fatty acids is suppressed rapidly during ischemia, the behavior of fatty acid extraction at different flow rates is incompletely understood. This study assessed the relationship between flow and extraction of (123)I-iodophenylpentadecanoic acid (IPPA) in the isolated heart model, especially at low flow. Isolated hearts from male Wistar rats (n = 15) were subjected to retrograde perfusion with constant flow (Krebs Henseleit solution containing 10 mmol/L glucose). A latex balloon in the left ventricle allowed isovolumetric contractions and ventricular pressure measurements. The extraction of (123)I-IPPA was assessed with the indicator dilution technique and (99m)Tc-albumin as the intravascular reference. The flow was either increased from the control flow (8 mL/min) until 300% or reduced until 10%. (123)I-IPPA extraction was measured three times before and 10 min after flow alteration. The tracer uptake was estimated from the product of net extraction and flow. The mean (123)I-IPPA extraction at the control flow (third measurement) was 51.6% +/- 2.8%. Between flow rates of approximately 25% and 300%, (123)I-IPPA extraction increased exponentially at decreasing flow rates. At flow rates < or =25% of the control flow, (123)I-IPPA extraction was exponentially higher than predicted. (123)I-IPPA uptake and flow changed largely in parallel. During low flow, the rate-pressure product showed the expected decline (perfusion-contraction matching). The extraction of (123)I-IPPA is preserved and slightly increased (relative to flow) during acute low-flow ischemia.

An Immunoglobulin G1 Monoclonal Antibody Highly Specific to the Wall of Cryptosporidium Oocysts

PubMed Central

Weir, C.; Vesey, G.; Slade, M.; Ferrari, B.; Veal, D. A.; Williams, K.

2000-01-01

The detection of Cryptosporidium oocysts in drinking water is critically dependent on the quality of immunofluorescent reagents. Experiments were performed to develop a method for producing highly specific antibodies to Cryptosporidium oocysts that can be used for water testing. BALB/c mice were immunized with six different antigen preparations and monitored for immunoglobulin G (IgG) and IgM responses to the surface of Cryptosporidium oocysts. One group of mice received purified oocyst walls, a second group received a soluble protein preparation extracted from the outside of the oocyst wall, and the third group received whole inactivated oocysts. Three additional groups were immunized with sequentially prepared oocyst extracts to provide for a comparison of the immune response. Mice injected with the soluble protein extract demonstrated an IgG response to oocysts surface that was not seen in the whole-oocyst group. Mice injected with whole oocysts showed an IgM response only, while mice injected with purified oocyst walls showed little increase in IgM or IgG levels. Of the additional reported preparations only one, BME (2-mercaptoethanol treated), produced a weak IgM response to the oocyst wall. A mouse from the soluble oocyst extract group yielding a high IgG response was utilized to produce a highly specific IgG1 monoclonal antibody (Cry104) specific to the oocyst surface. Comparative flow cytometric analysis indicated that Cry104 has a higher avidity and specificity to oocysts in water concentrates than other commercially available antibodies. PMID:10973448

Arrow-wing supersonic cruise aircraft structural design concepts evaluation. Volume 1: Sections 1 through 6

NASA Technical Reports Server (NTRS)

Sakata, I. F.; Davis, G. W.

1975-01-01

The structural approach best suited for the design of a Mach 2.7 arrow-wing supersonic cruise aircraft was investigated. Results, procedures, and principal justification of results are presented. Detailed substantiation data are given. In general, each major analysis is presented sequentially in separate sections to provide continuity in the flow of the design concepts analysis effort. In addition to the design concepts evaluation and the detailed engineering design analyses, supporting tasks encompassing: (1) the controls system development; (2) the propulsion-airframe integration study; and (3) the advanced technology assessment are presented.

Testing sequential extraction methods for the analysis of multiple stable isotope systems from a bone sample

NASA Astrophysics Data System (ADS)

Sahlstedt, Elina; Arppe, Laura

2017-04-01

Stable isotope composition of bones, analysed either from the mineral phase (hydroxyapatite) or from the organic phase (mainly collagen) carry important climatological and ecological information and are therefore widely used in paleontological and archaeological research. For the analysis of the stable isotope compositions, both of the phases, hydroxyapatite and collagen, have their more or less well established separation and analytical techniques. Recent development in IRMS and wet chemical extraction methods have facilitated the analysis of very small bone fractions (500 μg or less starting material) for PO43-O isotope composition. However, the uniqueness and (pre-) historical value of each archaeological and paleontological finding lead to preciously little material available for stable isotope analyses, encouraging further development of microanalytical methods for the use of stable isotope analyses. Here we present the first results in developing extraction methods for combining collagen C- and N-isotope analyses to PO43-O-isotope analyses from a single bone sample fraction. We tested sequential extraction starting with dilute acid demineralization and collection of both collagen and PO43-fractions, followed by further purification step by H2O2 (PO43-fraction). First results show that bone sample separates as small as 2 mg may be analysed for their δ15N, δ13C and δ18OPO4 values. The method may be incorporated in detailed investigation of sequentially developing skeletal material such as teeth, potentially allowing for the investigation of interannual variability in climatological/environmental signals or investigation of the early life history of an individual.

The Solution to Pollution is Distribution: Design Your Own Chaotic Flow

NASA Astrophysics Data System (ADS)

Tigera, R. G.; Roth, E. J.; Neupauer, R.; Mays, D. C.

2015-12-01

Plume spreading promotes the molecular mixing that drives chemical reactions in porous media in general, and remediation reactions in groundwater aquifers in particular. Theoretical analysis suggests that engineered injection and extraction, a specific sequence of pumping through wells surrounding a contaminant plume, can improve groundwater remediation through chaotic advection. Selection of an engineered injection and extraction scheme is difficult, however, because the engineer is faced with the difficulty of recommending a pumping scheme for a contaminated site without having any previous knowledge of how the scheme will perform. To address this difficulty, this presentation describes a Graphical User Interface (GUI) designed to help engineers develop, test, and observe pumping schemes as described in previous research (Mays, D.C. and Neupauer, R.M., 2012, Plume spreading in groundwater by stretching and folding, Water Resour. Res., 48, W07501, doi:10.1029/2011WR011567). The inputs allow the user to manipulate the model conditions such as number of wells, plume size, and pumping scheme. Plume evolution is modeled, assuming no diffusion or dispersion, using analytical solutions for injection or extraction through individual wells or pairs or wells (i.e., dipoles). Using the GUI, an engineered injection and extraction scheme can be determined that best fits the remediation needs of the contaminated site. By creating multiple injection and extraction schemes, the user can learn about the plume shapes created from different schemes and, ultimately, recommend a pumping scheme based on some experience of fluid flow as shown in the GUI. The pumping schemes developed through this GUI are expected to guide more advanced modeling and laboratory studies that account for the crucial role of dispersion in groundwater remediation.

The promotion of hair regrowth by topical application of a Perilla frutescens extract through increased cell viability and antagonism of testosterone and dihydrotestosterone.

PubMed

Li, Jing-Jie; Li, Zheng; Gu, Li-Juan; Choi, Kang-Ju; Kim, Dong-Seon; Kim, Ho-Kyoung; Sung, Chang-Keun

2018-01-01

This study investigated the potential hair regrowth effects associated with a plant extract of Perilla frutescens, which was selected due to its putative hair regrowth activity. Extracts were prepared from dried P. frutescens suspended in distilled water, where the resultant aqueous suspension was fractionated sequentially using hexane, ethyl acetate, n-butanol, and distilled water. We observed that the n-butanol fraction resulted in the highest hair regrowth activity. The n-butanol soluble fraction of P. frutescens extract (BFPE) was further separated using AB-8 macroporous resin and silica gel chromatography to obtain rosmarinic acid (RA), which demonstrated effective hair growth regeneration potential. BFPE also showed in vivo anti-androgenic activity following the use of a hair growth assay in testosterone-sensitive male C57Bl/6NCrSlc mice. Furthermore, the effects of cell viability promotion were investigated following an in vitro analysis in primary hair follicle fibroblast cells (PHFCs) treated with RA. The results suggested that RA was the active compound in P. frutescens that triggers hair growth, and RA could be a potential therapeutic agent for the promotion of hair growth and prevention of androgenetic alopecia (AGA).

The sequential structure of brain activation predicts skill.

PubMed

Anderson, John R; Bothell, Daniel; Fincham, Jon M; Moon, Jungaa

2016-01-29

In an fMRI study, participants were trained to play a complex video game. They were scanned early and then again after substantial practice. While better players showed greater activation in one region (right dorsal striatum) their relative skill was better diagnosed by considering the sequential structure of whole brain activation. Using a cognitive model that played this game, we extracted a characterization of the mental states that are involved in playing a game and the statistical structure of the transitions among these states. There was a strong correspondence between this measure of sequential structure and the skill of different players. Using multi-voxel pattern analysis, it was possible to recognize, with relatively high accuracy, the cognitive states participants were in during particular scans. We used the sequential structure of these activation-recognized states to predict the skill of individual players. These findings indicate that important features about information-processing strategies can be identified from a model-based analysis of the sequential structure of brain activation. Copyright © 2015 Elsevier Ltd. All rights reserved.

Development of high-accuracy convection schemes for sequential solvers

NASA Technical Reports Server (NTRS)

Thakur, Siddharth; Shyy, Wei

1993-01-01

An exploration is conducted of the applicability of such high resolution schemes as TVD to the resolving of sharp flow gradients using a sequential solution approach borrowed from pressure-based algorithms. It is shown that by extending these high-resolution shock-capturing schemes to a sequential solver that treats the equations as a collection of scalar conservation equations, the speed of signal propagation in the solution has to be coordinated by assigning the local convection speed as the characteristic speed for the entire system. A higher amount of dissipation is therefore needed to eliminate oscillations near discontinuities.

Computational fluid dynamics study of the end-side and sequential coronary artery bypass anastomoses in a native coronary occlusion model.

PubMed

Matsuura, Kaoru; Jin, Wei Wei; Liu, Hao; Matsumiya, Goro

2018-04-01

The objective of this study was to evaluate the haemodynamic patterns in each anastomosis fashion using a computational fluid dynamic study in a native coronary occlusion model. Fluid dynamic computations were carried out with ANSYS CFX (ANSYS Inc., Canonsburg, PA, USA) software. The incision lengths for parallel and diamond anastomoses were fixed at 2 mm. Native vessels were set to be totally occluded. The diameter of both the native and graft vessels was set to be 2 mm. The inlet boundary condition was set by a sample of the transient time flow measurement which was measured intraoperatively. The diamond anastomosis was observed to reduce flow to the native outlet and increase flow to the bypass outlet; the opposite was observed in the parallel anastomosis. Total energy efficiency was higher in the diamond anastomosis than the parallel anastomosis. Wall shear stress was higher in the diamond anastomosis than in the parallel anastomosis; it was the highest at the top of the outlet. A high oscillatory shear index was observed at the bypass inlet in the parallel anastomosis and at the native inlet in the diamond anastomosis. The diamond sequential anastomosis would be an effective option for multiple sequential bypasses because of the better flow to the bypass outlet than with the parallel anastomosis. However, flow competition should be kept in mind while using the diamond anastomosis for moderately stenotic vessels because of worsened flow to the native outlet. Care should be taken to ensure that the fluid dynamics patterns are optimal and prevent future native and bypass vessel disease progression.

Creating fast flow channels in paper fluidic devices to control timing of sequential reactions.

PubMed

Jahanshahi-Anbuhi, Sana; Chavan, Puneet; Sicard, Clémence; Leung, Vincent; Hossain, S M Zakir; Pelton, Robert; Brennan, John D; Filipe, Carlos D M

2012-12-07

This paper reports the development of a method to control the flow rate of fluids within paper-based microfluidic analytical devices. We demonstrate that by simply sandwiching paper channels between two flexible films, it is possible to accelerate the flow of water through paper by over 10-fold. The dynamics of this process are such that the height of the liquid is dependent on time to the power of 1/3. This dependence was validated using three different flexible films (with markedly different contact angles) and three different fluids (water and two silicon oils with different viscosities). These covered channels provide a low-cost method for controlling the flow rate of fluid in paper channels, and can be added following printing of reagents to control fluid flow in selected fluidic channels. Using this method, we redesigned a previously published bidirectional lateral flow pesticide sensor to allow more rapid detection of pesticides while eliminating the need to run the assay in two stages. The sensor is fabricated with sol-gel entrapped reagents (indoxyl acetate in a substrate zone and acetylcholinesterase, AChE, in a sensing zone) present in an uncovered "slow" flow channel, with a second, covered "fast" channel used to transport pesticide samples to the sensing region through a simple paper-flap valve. In this manner, pesticides reach the sensing region first to allow preincubation, followed by delivery of the substrate to generate a colorimetric signal. This format results in a uni-directional device that detects the presence of pesticides two times faster than the original bidirectional sensors.

Binding intensity and metal partitioning in soils affected by mining and smelting activities in Minas Gerais, Brazil.

PubMed

Lopes, G; Costa, E T S; Penido, E S; Sparks, D L; Guilherme, L R G

2015-09-01

Mining and smelting activities are potential sources of heavy metal contamination, which pose a threat to human health and ecological systems. This study investigated single and sequential extractions of Zn, Pb, and Cd in Brazilian soils affected by mining and smelting activities. Soils from a Zn mining area (soils A, B, C, D, E, and the control soil) and a tailing from a smelting area were collected in Minas Gerais state, Brazil. The samples were subjected to single (using Mehlich I solution) and sequential extractions. The risk assessment code (RAC), the redistribution index (U ts ), and the reduced partition index (I R ) have been applied to the sequential extraction data. Zinc and Cd, in soil samples from the mining area, were found mainly associated with carbonate forms. This same pattern did not occur for Pb. Moreover, the Fe-Mn oxides and residual fractions had important contributions for Zn and Pb in those soils. For the tailing, more than 70 % of Zn and Cd were released in the exchangeable fraction, showing a much higher mobility and availability of these metals at this site, which was also supported by results of RAC and I R . These differences in terms of mobility might be due to different chemical forms of the metals in the two sites, which are attributable to natural occurrence as well as ore processing.

Identification and Characterization of Cell Wall Proteins of a Toxic Dinoflagellate Alexandrium catenella Using 2-D DIGE and MALDI TOF-TOF Mass Spectrometry

PubMed Central

Wang, Da-Zhi; Dong, Hong-Po; Li, Cheng; Xie, Zhang-Xian; Lin, Lin; Hong, Hua-Sheng

2011-01-01

The cell wall is an important subcellular component of dinoflagellate cells with regard to various aspects of cell surface-associated ecophysiology, but the full range of cell wall proteins (CWPs) and their functions remain to be elucidated. This study identified and characterized CWPs of a toxic dinoflagellate, Alexandrium catenella, using a combination of 2D fluorescence difference gel electrophoresis (DIGE) and MALDI TOF-TOF mass spectrometry approaches. Using sequential extraction and temperature shock methods, sequentially extracted CWPs and protoplast proteins, respectively, were separated from A. catenella. From the comparison between sequentially extracted CWPs labeled with Cy3 and protoplast proteins labeled with Cy5, 120 CWPs were confidently identified in the 2D DIGE gel. These proteins gave positive identification of protein orthologues in the protein database using de novo sequence analysis and homology-based search. The majority of the prominent CWPs identified were hypothetical or putative proteins with unknown function or no annotation, while cell wall modification enzymes, cell wall structural proteins, transporter/binding proteins, and signaling and defense proteins were tentatively identified in agreement with the expected role of the extracellular matrix in cell physiology. This work represents the first attempt to investigate dinoflagellate CWPs and provides a potential tool for future comprehensive characterization of dinoflagellate CWPs and elucidation of their physiological functions. PMID:21904561

Selenium speciation in seleniferous agricultural soils under different cropping systems using sequential extraction and X-ray absorption spectroscopy.

PubMed

Qin, Hai-Bo; Zhu, Jian-Ming; Lin, Zhi-Qing; Xu, Wen-Po; Tan, De-Can; Zheng, Li-Rong; Takahashi, Yoshio

2017-06-01

Selenium (Se) speciation in soil is critically important for understanding the solubility, mobility, bioavailability, and toxicity of Se in the environment. In this study, Se fractionation and chemical speciation in agricultural soils from seleniferous areas were investigated using the elaborate sequential extraction and X-ray absorption near-edge structure (XANES) spectroscopy. The speciation results quantified by XANES technique generally agreed with those obtained by sequential extraction, and the combination of both approaches can reliably characterize Se speciation in soils. Results showed that dominant organic Se (56-81% of the total Se) and lesser Se(IV) (19-44%) were observed in seleniferous agricultural soils. A significant decrease in the proportion of organic Se to the total Se was found in different types of soil, i.e., paddy soil (81%) > uncultivated soil (69-73%) > upland soil (56-63%), while that of Se(IV) presented an inverse tendency. This suggests that Se speciation in agricultural soils can be significantly influenced by different cropping systems. Organic Se in seleniferous agricultural soils was probably derived from plant litter, which provides a significant insight for phytoremediation in Se-laden ecosystems and biofortification in Se-deficient areas. Furthermore, elevated organic Se in soils could result in higher Se accumulation in crops and further potential chronic Se toxicity to local residents in seleniferous areas. Copyright © 2017 Elsevier Ltd. All rights reserved.

The Intelligent Management System: An Overview.

DTIC Science & Technology

1982-12-07

comprises of hundreds of subprocesses concerned with bulb grasping, positioning, heating, cooling, etc. Each is sequentially related with others in time...activity. Activity schemata can be constructed into a network to define both parallel and sequential precedence, and hierarchical to describe...The flow of work is controlled by the "operation- lineup " associated with the product being manufactured. The operation- lineup specifies the sequence of

Information Management: Publishing and Printing: Army Publishing: Action Officers Guide

DTIC Science & Technology

2002-04-30

types of lists: ordered (such as numerical, alphabetical, or sequential ), bulleted, or dashed. (4) Extracted material in an appendix must be identified...provide supporting, expanded, or sequential doctrinal manuals within a functional field (this number group must not exceed 3 digits). Table 13–2...rubup, opaquing, lineup , and register, and so forth 1,2 190 DA PAM 25–40 • 30 April 2002 Table J–5 Camera, platemaking, and related equipment—Continued

Classification of epileptic EEG signals based on simple random sampling and sequential feature selection.

PubMed

Ghayab, Hadi Ratham Al; Li, Yan; Abdulla, Shahab; Diykh, Mohammed; Wan, Xiangkui

2016-06-01

Electroencephalogram (EEG) signals are used broadly in the medical fields. The main applications of EEG signals are the diagnosis and treatment of diseases such as epilepsy, Alzheimer, sleep problems and so on. This paper presents a new method which extracts and selects features from multi-channel EEG signals. This research focuses on three main points. Firstly, simple random sampling (SRS) technique is used to extract features from the time domain of EEG signals. Secondly, the sequential feature selection (SFS) algorithm is applied to select the key features and to reduce the dimensionality of the data. Finally, the selected features are forwarded to a least square support vector machine (LS_SVM) classifier to classify the EEG signals. The LS_SVM classifier classified the features which are extracted and selected from the SRS and the SFS. The experimental results show that the method achieves 99.90, 99.80 and 100 % for classification accuracy, sensitivity and specificity, respectively.

Low-pressure sequential compression of lower limbs enhances forearm skin blood flow.

PubMed

Amah, Guy; Voicu, Sebastian; Bonnin, Philippe; Kubis, Nathalie

2016-12-01

We investigated whether forearm skin blood flow could be improved when a multilayer pulsatile inflatable suit was applied at a low pressure to the lower limbs and abdomen. We hypothesized that a non-invasive purely mechanical stimulation of the lower limbs could induce remote forearm blood flow modifications. The pulsatile suit induced a sequential compartmentalized low compression (65 mmHg), which was synchronized with each diastole of the cardiac cycle with each phase evolving centripetally (lower limbs to abdomen). Modifications of the forearm skin blood flow were continuously recorded by laser Doppler flowmetry (LDF) at baseline and during the pulsatile suit application. Endothelium-dependent and endothelium-independent vasodilations of the forearm skin microcirculation were measured by LDF in response to a local transdermal iontophoretic application of acetylcholine (ACh-test) and to hyperthermia (hyperT- test). Twenty-four healthy volunteers, 12 men and 12 women (43±14 years) were included in the study. LDF responses increased 1) under pulsatile suit (97±106%, p.

Bioleaching of vanadium from barren stone coal and its effect on the transition of vanadium speciation and mineral phase

NASA Astrophysics Data System (ADS)

Wang, Xin; Lin, Hai; Dong, Ying-bo; Li, Gan-yu

2018-03-01

This study determined the optimal conditions required to obtain maximum vanadium extraction and examined the transition of mineral phases and vanadium speciation during the bioleaching process. Parameters including the initial pH value, initial Fe2+ concentration, solid load, and inoculum quantity were examined. The results revealed that 48.92wt% of the vanadium was extracted through bioleaching under optimal conditions. Comparatively, the chemical leaching yield (H2SO4, pH 2.0) showed a slower and milder increase in vanadium yield. The vanadium bioleaching yield was 35.11wt% greater than the chemical leaching yield. The Community Bureau of Reference (BCR) sequential extraction results revealed that 88.62wt% of vanadium existed in the residual fraction. The bacteria substantially changed the distribution of the vanadium speciation during the leaching process, and the residual fraction decreased to 48.44wt%. The X-ray diffraction (XRD) and Fourier transform infrared (FTIR) results provided evidence that the crystal lattice structure of muscovite was destroyed by the bacteria.

Determination and partitioning of metals in sediments along the Suez Canal by sequential extraction

NASA Astrophysics Data System (ADS)

Abd El-Azim, H.; El-Moselhy, Kh. M.

2005-06-01

The application of sequential extraction technique was used to determine the chemical association of heavy metals in five different chemical phases (exchangeable F1, bound to carbonate F2, bound to Fe-Mn oxides F3, bound to organic matter F4 and residual F5) for sediment samples collected from the Suez Canal. From the obtained data, it can be seen that the surplus of metal contaminants introduced into the sediment from sources usually exists in relatively unstable chemical forms. A high proportion of the studied metals remained in the residual fraction. Most of remaining portion of metals was bound to ferromanganese oxides fraction. The low concentrations of metals in the exchangeable fraction indicated that the sediments of Suez Canal were relatively unpolluted.

Instant controlled pressure drop technology and ultrasound assisted extraction for sequential extraction of essential oil and antioxidants.

PubMed

Allaf, Tamara; Tomao, Valérie; Ruiz, Karine; Chemat, Farid

2013-01-01

The instant controlled pressure drop (DIC) technology enabled both the extraction of essential oil and the expansion of the matrix itself which improved solvent extraction. The sequential use of DIC and Ultrasound Assisted Extraction (UAE) triggered complementary actions materialized by supplementary effects. We visualized these combination impacts by comparing them to standard techniques: Hydrodistillation (HD) and Solvent Extraction (SE). First, the extraction of orange peel Essential Oils (EO) was achieved by HD during 4h and DIC process (after optimization) during 2 min; EO yields was 1.97 mg/g dry material (dm) with HD compared to 16.57 mg/g d m with DIC. Second, the solid residue was recovered to extract antioxidant compounds (naringin and hesperidin) by SE and UAE. Scanning electron microscope showed that after HD the recovered solid shriveled as opposite to DIC treatment which expanded the product structure. HPLC analyses showed that the best kinetics and yields of naringin and hesperidin extraction was when DIC and UAE are combined. Indeed, after 1h of extraction, DIC treated orange peels with UAE were 0.825 ± 1.6 × 10(-2)g/g of dry material (dm) for hesperidin and 6.45 × 10(-2) ± 2.3 × 10(-4)g/g d m for naringin compared to 0.64 ± 2.7 × 10(-2)g/g of dry material (dm) and 5.7 × 10(-2) ± 1.6 × 10(-3)g/g d m, respectively with SE. By combining DIC to UAE, it was possible to enhance kinetics and yields of antioxidant extraction. Copyright © 2012 Elsevier B.V. All rights reserved.

Determination of available phosphorus in soils by using a new extraction procedure and a flow injection amperometric system.

PubMed

Jakmunee, Jaroon; Junsomboon, Jaroon

2009-09-15

A new extraction procedure based on an off-line extraction column was proposed for extracting of available phosphorus from soils. The column was fabricated from a plastic syringe fitted at the bottom with a cotton wool and a piece of filter paper to support a soil sample. An aliquot (50 mL) of extracting solution (0.05 M HCl+0.0125 M H(2)SO(4)) was used to extract the sample under gravity flow and the eluate was collected in a polyethylene bottle. The extract was then analyzed for phosphorus contents by a simple flow injection amperometric system, employing a set of three-way solenoid valves as an injection valve. The method is based on the electrochemical reduction of 12-molybdophosphate which is produced on-line by the reaction of orthophosphate with acidic molybdate and the electrical current produced was directly proportional to the concentration of phosphate in range of 0.1-10.0 mg L(-1) PO(4)-P, with a detection limit of 0.02 mg L(-1). Relative standard for 11 replicate injections of 5 mg L(-1) PO(4)-P was 0.5%. A sample through put of 35 h(-1) was achieved, with consumption of 14 mg KCl, 10mg ammonium molybdate and 0.05 mL H(2)SO(4) per analysis. The detection system does not suffer from the interferences that are encountered in the photometric method such as colored substances, colloids, metal ions, silicate and refractive index effect (Schlieren effect). The results obtained by the column extraction procedure were well correlated with those obtained by the steady-state extraction procedure, but showed slightly higher extraction efficiency.

Structural and spectrophotometric characterization of 2-[4-(dimethylamino)styryl]-1-ethylquinolinium iodide as a reagent for sequential injection determination of tungsten

NASA Astrophysics Data System (ADS)

Bazel, Yaroslav; Lešková, Martina; Rečlo, Michal; Šandrejová, Jana; Simon, András; Fizer, Maksym; Sidey, Vasyl

2018-05-01

Structure, spectrophotometric and protolytic properties of the styryl dye 2-[4-(dimethylamino)styryl]-1-ethylquinolinium iodide (R) as well as its complex with tungsten were studied. The selective protonation of dimethylamino group was confirmed by density functional theory investigation through the computation of Fukui function, NPA partial atomic charges, and NICS(0) aromaticity indexes. The TD-DFT study explains the experimental change of color by excluding the dimethylamino group from HOMO orbital upon protonation. The acid dissociation constant, the optimum wavelength and the molar absorptivity of R were found to be: 3.02, 501 nm and 4.0 × 104 L mol-1 cm-1, respectively. The protolytic properties of the reagent were found to change significantly in the presence of tungsten(VI). Analysis of bond critical points between the anions and Quinaldine Red cation gives the selectivity raw HWO4- > MoO4-> H2VO4- > ReO4- > ClO4-, that perfectly match with the experimental data. Based on this observation, a non-extractive sequential-injection spectrophotometric method for the determination of tungsten was developed. The absorbance of the colored extracts obeys Beer's law up to 55.2 mg L-1 of W at 520 nm wavelength. The limit of detection calculated from a blank test (n = 10) based on 3 s was 0.96 mg L-1. The developed method was applied for the determination of tungsten in model samples.

Phytoextraction of metals by Erigeron canadensis L. from fly ash landfill of power plant "Kolubara".

PubMed

Krgović, Rada; Trifković, Jelena; Milojković-Opsenica, Dušanka; Manojlović, Dragan; Marković, Marijana; Mutić, Jelena

2015-07-01

The objectives of this study were to determine the concentrations of Pb, Cd, As, Cr, Cu, Co, Ni, Zn, Ba, Fe, Al and Ag in Erigeron canadensis L. growing on fly ash landfill of power plant "Kolubara", Serbia. The content of each element was determined in every part of plant separately (root, stalk and inflorescence) and correlated with the content of elements in each phase of sequential extraction of fly ash. In order to ambiguously select the factors that are able to decidedly characterize the particular part of plant, principal component analysis (PCA) and partial least squares discriminant analysis (PLS-DA) were performed. The bioconcentration factors and translocation factors for each metal were calculated in order to determine the feasibility of the use of plant E. canadensis L. for phytoremediation purpose. There were strong positive correlations between metals in every part of plant samples, and metals from pseudo total form of sequential extraction indicate that the bioavailability of elements in fly ash is similarly correlated with total form. Retained Al, Fe, Cr and Co in the root indicate its suitability for phytostabilization. This plant takes up Cd and Zn from the soil (bioconcentration factors (BCFs) greater than 1), transporting them through the stalk into the inflorescence (translocation factors (TFs) higher than 1). Regarding its dominance in vegetation cover and abundance, E. canadensis L. can be considered adequate for phytoextraction of Cd and Zn from coal ash landfills at Kolubara.

Secretome analysis of Trichoderma reesei and Aspergillus niger cultivated by submerged and sequential fermentation processes: Enzyme production for sugarcane bagasse hydrolysis.

PubMed

Florencio, Camila; Cunha, Fernanda M; Badino, Alberto C; Farinas, Cristiane S; Ximenes, Eduardo; Ladisch, Michael R

2016-08-01

Cellulases and hemicellulases from Trichoderma reesei and Aspergillus niger have been shown to be powerful enzymes for biomass conversion to sugars, but the production costs are still relatively high for commercial application. The choice of an effective microbial cultivation process employed for enzyme production is important, since it may affect titers and the profile of protein secretion. We used proteomic analysis to characterize the secretome of T. reesei and A. niger cultivated in submerged and sequential fermentation processes. The information gained was key to understand differences in hydrolysis of steam exploded sugarcane bagasse for enzyme cocktails obtained from two different cultivation processes. The sequential process for cultivating A. niger gave xylanase and β-glucosidase activities 3- and 8-fold higher, respectively, than corresponding activities from the submerged process. A greater protein diversity of critical cellulolytic and hemicellulolytic enzymes were also observed through secretome analyses. These results helped to explain the 3-fold higher yield for hydrolysis of non-washed pretreated bagasse when combined T. reesei and A. niger enzyme extracts from sequential fermentation were used in place of enzymes obtained from submerged fermentation. An enzyme loading of 0.7 FPU cellulase activity/g glucan was surprisingly effective when compared to the 5-15 times more enzyme loadings commonly reported for other cellulose hydrolysis studies. Analyses showed that more than 80% consisted of proteins other than cellulases whose role is important to the hydrolysis of a lignocellulose substrate. Our work combined proteomic analyses and enzymology studies to show that sequential and submerged cultivation methods differently influence both titers and secretion profile of key enzymes required for the hydrolysis of sugarcane bagasse. The higher diversity of feruloyl esterases, xylanases and other auxiliary hemicellulolytic enzymes observed in the enzyme mixtures from the sequential fermentation could be one major reason for the more efficient enzyme hydrolysis that results when using the combined secretomes from A. niger and T. reesei. Copyright © 2016 Elsevier Inc. All rights reserved.

Moving object localization using optical flow for pedestrian detection from a moving vehicle.

PubMed

Hariyono, Joko; Hoang, Van-Dung; Jo, Kang-Hyun

2014-01-01

This paper presents a pedestrian detection method from a moving vehicle using optical flows and histogram of oriented gradients (HOG). A moving object is extracted from the relative motion by segmenting the region representing the same optical flows after compensating the egomotion of the camera. To obtain the optical flow, two consecutive images are divided into grid cells 14 × 14 pixels; then each cell is tracked in the current frame to find corresponding cell in the next frame. Using at least three corresponding cells, affine transformation is performed according to each corresponding cell in the consecutive images, so that conformed optical flows are extracted. The regions of moving object are detected as transformed objects, which are different from the previously registered background. Morphological process is applied to get the candidate human regions. In order to recognize the object, the HOG features are extracted on the candidate region and classified using linear support vector machine (SVM). The HOG feature vectors are used as input of linear SVM to classify the given input into pedestrian/nonpedestrian. The proposed method was tested in a moving vehicle and also confirmed through experiments using pedestrian dataset. It shows a significant improvement compared with original HOG using ETHZ pedestrian dataset.

Two new xanthones from Calophyllum nodusum (Guttiferae).

PubMed

Nasir, Nadiah Mad; Rahmani, Mawardi; Shaari, Khozirah; Ee, Gwendoline Cheng Lian; Go, Rusea; Kassim, Nur Kartinee; Muhamad, Siti Noor Kamilah; Iskandar, Mohd Johadi

2011-10-25

The air-dried powdered stem bark of Calophyllum nodusum (Guttiferea) collected from Sandakan (Sabah, Malaysia), was extracted sequentially with hexane, chloroform and methanol. The solvents were removed by rotary evaporator to give dark viscous extracts. Detailed and repeated chromatographic separation of the extracts lead to isolation of two new xanthones, identified as nodusuxanthone and trapezifolixanthone A. Other common terpenoids such as betulinic acid, lupeol, stigmasterol and friedelin were also isolated from the extracts and identified. The structures of the compounds were established by detailed spectral analysis and comparison with previously reported data.

Sequentially Integrated Optimization of the Conditions to Obtain a High-Protein and Low-Antinutritional Factors Protein Isolate from Edible Jatropha curcas Seed Cake.

PubMed

León-López, Liliana; Dávila-Ortiz, Gloria; Jiménez-Martínez, Cristian; Hernández-Sánchez, Humberto

2013-01-01

Jatropha curcas seed cake is a protein-rich byproduct of oil extraction which could be used to produce protein isolates. The purpose of this study was the optimization of the protein isolation process from the seed cake of an edible provenance of J. curcas by an alkaline extraction followed by isoelectric precipitation method via a sequentially integrated optimization approach. The influence of four different factors (solubilization pH, extraction temperature, NaCl addition, and precipitation pH) on the protein and antinutritional compounds content of the isolate was evaluated. The estimated optimal conditions were an extraction temperature of 20°C, a precipitation pH of 4, and an amount of NaCl in the extraction solution of 0.6 M for a predicted protein content of 93.3%. Under these conditions, it was possible to obtain experimentally a protein isolate with 93.21% of proteins, 316.5 mg 100 g(-1) of total phenolics, 2891.84 mg 100 g(-1) of phytates and 168 mg 100 g(-1) of saponins. The protein content of the this isolate was higher than the content reported by other authors.

Sequentially Integrated Optimization of the Conditions to Obtain a High-Protein and Low-Antinutritional Factors Protein Isolate from Edible Jatropha curcas Seed Cake

PubMed Central

León-López, Liliana; Dávila-Ortiz, Gloria; Jiménez-Martínez, Cristian; Hernández-Sánchez, Humberto

2013-01-01

Jatropha curcas seed cake is a protein-rich byproduct of oil extraction which could be used to produce protein isolates. The purpose of this study was the optimization of the protein isolation process from the seed cake of an edible provenance of J. curcas by an alkaline extraction followed by isoelectric precipitation method via a sequentially integrated optimization approach. The influence of four different factors (solubilization pH, extraction temperature, NaCl addition, and precipitation pH) on the protein and antinutritional compounds content of the isolate was evaluated. The estimated optimal conditions were an extraction temperature of 20°C, a precipitation pH of 4, and an amount of NaCl in the extraction solution of 0.6 M for a predicted protein content of 93.3%. Under these conditions, it was possible to obtain experimentally a protein isolate with 93.21% of proteins, 316.5 mg 100 g−1 of total phenolics, 2891.84 mg 100 g−1 of phytates and 168 mg 100 g−1 of saponins. The protein content of the this isolate was higher than the content reported by other authors. PMID:25937971

Sequential protein extraction as an efficient method for improved proteome coverage in larvae of Atlantic salmon (Salmo salar).

PubMed

Nuez-Ortín, Waldo G; Carter, Chris G; Nichols, Peter D; Wilson, Richard

2016-07-01

Understanding diet- and environmentally induced physiological changes in fish larvae is a major goal for the aquaculture industry. Proteomic analysis of whole fish larvae comprising multiple tissues offers considerable potential but is challenging due to the very large dynamic range of protein abundance. To extend the coverage of the larval phase of the Atlantic salmon (Salmo salar) proteome, we applied a two-step sequential extraction (SE) method, based on differential protein solubility, using a nondenaturing buffer containing 150 mM NaCl followed by a denaturing buffer containing 7 M urea and 2 M thiourea. Extracts prepared using SE and one-step direct extraction were characterized via label-free shotgun proteomics using nanoLC-MS/MS (LTQ-Orbitrap). SE partitioned the proteins into two fractions of approximately equal amounts, but with very distinct protein composition, leading to identification of ∼40% more proteins than direct extraction. This fractionation strategy enabled the most detailed characterization of the salmon larval proteome to date and provides a platform for greater understanding of physiological changes in whole fish larvae. The MS data are available via the ProteomeXchange Consortium PRIDE partner repository, dataset PXD003366. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Sequential cloud-point extraction for toxicological screening analysis of medicaments in human plasma by high pressure liquid chromatography with diode array detector.

PubMed

Madej, Katarzyna; Persona, Karolina; Wandas, Monika; Gomółka, Ewa

2013-10-18

A complex extraction system with the use of cloud-point extraction technique (CPE) was developed for sequential isolation of basic and acidic/neutral medicaments from human plasma/serum, screened by HPLC/DAD method. Eight model drugs (paracetamol, promazine, chlorpromazine, amitriptyline, salicyclic acid, opipramol, alprazolam and carbamazepine) were chosen for the study of optimal CPE conditions. The CPE technique consists in partition of an aqueous sample with addition of a surfactant into two phases: micelle-rich phase with the isolated compounds and water phase containing a surfactant below the critical micellar concentration, mainly under influence of temperature change. The proposed extraction system consists of two chief steps: isolation of basic compounds (from pH 12) and then isolation of acidic/neutral compounds (from pH 6) using surfactant Triton X-114 as the extraction medium. Extraction recovery varied from 25.2 to 107.9% with intra-day and inter-day precision (RSD %) ranged 0.88-1087 and 5.32-17.96, respectively. The limits of detection for the studied medicaments at λ 254nm corresponded to therapeutic or low toxic plasma concentration levels. Usefulness of the proposed CPE-HPLC/DAD method for toxicological drug screening was tested via its application to analysis of two serum samples taken from patients suspected of drug overdosing. Published by Elsevier B.V.

Improving Emergency Department flow through optimized bed utilization

PubMed Central

Chartier, Lucas Brien; Simoes, Licinia; Kuipers, Meredith; McGovern, Barb

2016-01-01

Over the last decade, patient volumes in the emergency department (ED) have grown disproportionately compared to the increase in staffing and resources at the Toronto Western Hospital, an academic tertiary care centre in Toronto, Canada. The resultant congestion has spilled over to the ED waiting room, where medically undifferentiated and potentially unstable patients must wait until a bed becomes available. The aim of this quality improvement project was to decrease the 90th percentile of wait time between triage and bed assignment (time-to-bed) by half, from 120 to 60 minutes, for our highest acuity patients. We engaged key stakeholders to identify barriers and potential strategies to achieve optimal flow of patients into the ED. We first identified multiple flow-interrupting challenges, including operational bottlenecks and cultural issues. We then generated change ideas to address two main underlying causes of ED congestion: unnecessary patient utilization of ED beds and communication breakdown causing bed turnaround delays. We subsequently performed seven tests of change through sequential plan-do-study-act (PDSA) cycles. The most significant gains were made by improving communication strategies: small gains were achieved through the optimization of in-house digital information management systems, while significant improvements were achieved through the implementation of a low-tech direct contact mechanism (a two-way radio or walkie-talkie). In the post-intervention phase, time-to-bed for the 90th percentile of high-acuity patients decreased from 120 minutes to 66 minutes, with special cause variation showing a significant shift in the weekly measurements. PMID:27752312

Improving Emergency Department flow through optimized bed utilization.

PubMed

Chartier, Lucas Brien; Simoes, Licinia; Kuipers, Meredith; McGovern, Barb

2016-01-01

Over the last decade, patient volumes in the emergency department (ED) have grown disproportionately compared to the increase in staffing and resources at the Toronto Western Hospital, an academic tertiary care centre in Toronto, Canada. The resultant congestion has spilled over to the ED waiting room, where medically undifferentiated and potentially unstable patients must wait until a bed becomes available. The aim of this quality improvement project was to decrease the 90th percentile of wait time between triage and bed assignment (time-to-bed) by half, from 120 to 60 minutes, for our highest acuity patients. We engaged key stakeholders to identify barriers and potential strategies to achieve optimal flow of patients into the ED. We first identified multiple flow-interrupting challenges, including operational bottlenecks and cultural issues. We then generated change ideas to address two main underlying causes of ED congestion: unnecessary patient utilization of ED beds and communication breakdown causing bed turnaround delays. We subsequently performed seven tests of change through sequential plan-do-study-act (PDSA) cycles. The most significant gains were made by improving communication strategies: small gains were achieved through the optimization of in-house digital information management systems, while significant improvements were achieved through the implementation of a low-tech direct contact mechanism (a two-way radio or walkie-talkie). In the post-intervention phase, time-to-bed for the 90th percentile of high-acuity patients decreased from 120 minutes to 66 minutes, with special cause variation showing a significant shift in the weekly measurements.

A stacked sequential learning method for investigator name recognition from web-based medical articles

NASA Astrophysics Data System (ADS)

Zhang, Xiaoli; Zou, Jie; Le, Daniel X.; Thoma, George

2010-01-01

"Investigator Names" is a newly required field in MEDLINE citations. It consists of personal names listed as members of corporate organizations in an article. Extracting investigator names automatically is necessary because of the increasing volume of articles reporting collaborative biomedical research in which a large number of investigators participate. In this paper, we present an SVM-based stacked sequential learning method in a novel application - recognizing named entities such as the first and last names of investigators from online medical journal articles. Stacked sequential learning is a meta-learning algorithm which can boost any base learner. It exploits contextual information by adding the predicted labels of the surrounding tokens as features. We apply this method to tag words in text paragraphs containing investigator names, and demonstrate that stacked sequential learning improves the performance of a nonsequential base learner such as an SVM classifier.

Correlated sequential tunneling through a double barrier for interacting one-dimensional electrons

NASA Astrophysics Data System (ADS)

Thorwart, M.; Egger, R.; Grifoni, M.

2005-07-01

The problem of resonant tunneling through a quantum dot weakly coupled to spinless Tomonaga-Luttinger liquids has been studied. We compute the linear conductance due to sequential tunneling processes upon employing a master equation approach. Besides the previously used lowest-order golden rule rates describing uncorrelated sequential tunneling processes, we systematically include higher-order correlated sequential tunneling (CST) diagrams within the standard Weisskopf-Wigner approximation. We provide estimates for the parameter regions where CST effects can be important. Focusing mainly on the temperature dependence of the peak conductance, we discuss the relation of these findings to previous theoretical and experimental results.

In situ distributions and characteristics of heavy metals in full-scale landfill layers.

PubMed

He, Pin-Jing; Xiao, Zheng; Shao, Li-Ming; Yu, Ji-Yu; Lee, Duu-Jong

2006-10-11

The leachate from methanogenic landfill normally contains low concentrations of heavy metals. Little samples had ever been collected from the full-scale landfill piles owing to technical difficulty for well drilling. We drilled two wells in Hangzhou Tianziling landfill, 20 m and 32 m in depth each, and collected solid samples of waste age of 1-4 years from both wells. The total amounts, the sequentially extracted amounts, and the chemical binding forms of heavy metals of the samples collected at different depths were measured. With the correlation between leachate production amount and the yearly rainfall amount, the leached ratio of the heavy metals were estimated only 0.13%, 1.8%, 0.15%, and 0.19% of Cu, Cd, Pb, and Zn, respectively. The heavy metals amounts in the main compositions of MSW, like glass, food waste, paper, coal cinders, were measured using fresh MSW samples. Afterward, the contents of heavy metals initially landfilled were estimated. A positive correlation was noted between the measured and the estimated initial contents of heavy metals, indicating that the low migration of heavy metals in landfill layers. However, among the metals investigated, Zn has shown better mobility inside landfill layers. Acid volatile sulfide (AVS) and the simultaneously extracted metals (SEM) were measured for all collected samples with optimal reaction conditions identified to yield nearly perfect sulfide recovery as follows: 100 g wet samples, 80 mL min(-1) N(2) flow rate, reaction time of 150 min. The SEM/AVS ratios ranged 25-45, indicating that the AVS was insufficient to immobilize the SEM. Sequential extraction using six-fraction scheme revealed that the sum of exchangeable and the avid soluble fractions of heavy metals follow: Zn>Cd>Cu, Ni, Pb>Cr. The insoluble fraction of heavy metals in MSW was high, for instance, over 80% for Cr and Pb high insoluble fractions of heavy metals in the landfilled MSW and the sorption capability of the methanogenic landfill layers should be responsible to the low concentrations of heavy metals found in leachate.

Flow through a very porous obstacle in a shallow channel.

PubMed

Creed, M J; Draper, S; Nishino, T; Borthwick, A G L

2017-04-01

A theoretical model, informed by numerical simulations based on the shallow water equations, is developed to predict the flow passing through and around a uniform porous obstacle in a shallow channel, where background friction is important. This problem is relevant to a number of practical situations, including flow through aquatic vegetation, the performance of arrays of turbines in tidal channels and hydrodynamic forces on offshore structures. To demonstrate this relevance, the theoretical model is used to (i) reinterpret core flow velocities in existing laboratory-based data for an array of emergent cylinders in shallow water emulating aquatic vegetation and (ii) reassess the optimum arrangement of tidal turbines to generate power in a tidal channel. Comparison with laboratory-based data indicates a maximum obstacle resistance (or minimum porosity) for which the present theoretical model is valid. When the obstacle resistance is above this threshold the shallow water equations do not provide an adequate representation of the flow, and the theoretical model over-predicts the core flow passing through the obstacle. The second application of the model confirms that natural bed resistance increases the power extraction potential for a partial tidal fence in a shallow channel and alters the optimum arrangement of turbines within the fence.

Novel full‐spectral flow cytometry with multiple spectrally‐adjacent fluorescent proteins and fluorochromes and visualization of in vivo cellular movement

PubMed Central

Futamura, Koji; Sekino, Masashi; Hata, Akihiro; Ikebuchi, Ryoyo; Nakanishi, Yasutaka; Egawa, Gyohei; Kabashima, Kenji; Watanabe, Takeshi; Furuki, Motohiro

2015-01-01

Abstract Flow cytometric analysis with multicolor fluoroprobes is an essential method for detecting biological signatures of cells. Here, we present a new full‐spectral flow cytometer (spectral‐FCM). Unlike conventional flow cytometer, this spectral‐FCM acquires the emitted fluorescence for all probes across the full‐spectrum from each cell with 32 channels sequential PMT unit after dispersion with prism, and extracts the signals of each fluoroprobe based on the spectral shape of each fluoroprobe using unique algorithm in high speed, high sensitive, accurate, automatic and real‐time. The spectral‐FCM detects the continuous changes in emission spectra from green to red of the photoconvertible protein, KikGR with high‐spectral resolution and separates spectrally‐adjacent fluoroprobes, such as FITC (Emission peak (Em) 519 nm) and EGFP (Em 507 nm). Moreover, the spectral‐FCM can measure and subtract autofluorescence of each cell providing increased signal‐to‐noise ratios and improved resolution of dim samples, which leads to a transformative technology for investigation of single cell state and function. These advances make it possible to perform 11‐color fluorescence analysis to visualize movement of multilinage immune cells by using KikGR‐expressing mice. Thus, the novel spectral flow cytometry improves the combinational use of spectrally‐adjacent various FPs and multicolor fluorochromes in metabolically active cell for the investigation of not only the immune system but also other research and clinical fields of use. © 2015 The Authors. Cytometry Part A Published by Wiley Periodicals, Inc. on behalf of ISAC PMID:26217952

Temporal pattern of toxicity in runoff from the Tijuana River Watershed.

PubMed

Gersberg, Richard M; Daft, Daniel; Yorkey, Darryl

2004-02-01

Samples were collected from the Tijuana River under both dry weather (baseflow) conditions and during wet weather, and tested for toxicity using Ceriodaphnia dubia tests. Toxicity of waters in the Tijuana River was generally low under baseflow conditions, but increased markedly during high flow runoff events. In order to determine the temporal pattern of toxicity during individual rain events, sequential grab samples were collected using an autosampler at 5-7 h intervals after the start of the rain event, and tested for acute toxicity. In all cases, peak toxicity values (ranging from 2.8 to 5.8TU) for each storm occurred within the first 1-2 h of initiation of the rain event, and were statistically higher (using the 95% CL) for each of the pre-storm base flow values. However, there was no statistically significant correlation (p<0.05) between flow rate and toxicity when all storm data was pooled. Additionally, we used toxicity identification evaluation (TIE) procedures to attempt to identify the classes of chemicals that account for this early storm toxicity. Solid phase extraction was the only treatment that showed consistent and significant (P<0.05) removal of toxicity. These TIEs, conducted on the most toxic sample of the river's flow during runoff events, suggest that non-polar organics may be responsible for such toxicity. The temporal pattern of toxicity, both during a given storm event and seasonally, indicates that wash-off from the watershed by rainfall may deplete the supply of toxicity available for wash-off in subsequent events, so that a clearly consistent relationship between flow and toxicity was not evident.

ABCG2/BCRP interaction with the sea grass Thalassia testudinum.

PubMed

Miguel, Verónica; Otero, Jon A; Barrera, Borja; Rodeiro, Idania; Prieto, Julio G; Merino, Gracia; Álvarez, Ana I

2015-12-01

The aqueous ethanolic extract from leaves of the marine plant Thalassia testudinum has shown antioxidant, cytoprotective, and neuroprotective properties. The chemical composition of this extract, rich in polyphenols, could interfere with active transport of drugs out of the cell and circumvent the phenomenon of multidrug resistance (MDR). The extract can act as an MDR modulator through its interaction with efflux transporters. The ABCG2/BCRP has been shown to confer MDR acting in tumor cells. To evaluate the interaction of ABCG2/BCRP with the extract, studies in cells overexpressing human BCRP transporter and its murine ortholog Bcrp1 were performed. T. testudinum extract could be included as MDR modulator, as interaction with ABCG2/BCRP has been shown through flow cytometry and MTT assays. The cells overexpressing ABCG2/BCRP in the presence of the extract (25-150 μg/mL) decreased the survival rates of the anti-tumoral mitoxantrone. Our results support its inclusion as a possible MDR modulator against tumor cells that overexpress ABCG2/BCRP.

Sequential PET estimation of cerebral oxygen metabolism with spontaneous respiration of 15O-gas in mice with bilateral common carotid artery stenosis.

PubMed

Temma, Takashi; Yamazaki, Makoto; Miyanohara, Jun; Shirakawa, Hisashi; Kondo, Naoya; Koshino, Kazuhiro; Kaneko, Shuji; Iida, Hidehiro

2017-10-01

Positron emission tomography with 15 O-labeled gases ( 15 O-PET) is important for in vivo measurement of cerebral oxygen metabolism both in clinical and basic settings. However, there are currently no reports concerning 15 O-PET in mice. Here, we developed an 15 O-PET method applicable to mice with spontaneous respiration of 15 O-gas without a tracheotomy catheter. Sequential 15 O-PET was also performed in a mouse model of chronic cerebral hypoperfusion with bilateral common carotid artery stenosis (BCAS) induced by placement of microcoils. 15 O-gas with isoflurane was supplied to the nose of mouse with evacuation of excess 15 O-gas surrounding the body. 15 O-PET was performed on days 3, 7, 14, 21, and 28 after surgery. Cerebral blood flow (CBF), cerebral blood volume, oxygen extraction fraction (OEF), and cerebral metabolic rate of oxygen (CMRO 2 ) were calculated in whole brains. A significant decrease in CBF and compensatory increase in OEF in the BCAS group produced CMRO 2 values comparable to that of the sham group at three days post-operation. Although CBF and OEF in the BCAS group gradually recovered over the first 28 days, the CMRO 2 showed a gradual decrease to 68% of sham values at 28 days post-operation. In conclusion, we successfully developed a noninvasive 15 O-PET method for mice.

Electricity-Free, Sequential Nucleic Acid and Protein Isolation

PubMed Central

Pawlowski, David R.; Karalus, Richard J.

2012-01-01

Traditional and emerging pathogens such as Enterohemorrhagic Escherichia coli (EHEC), Yersinia pestis, or prion-based diseases are of significant concern for governments, industries and medical professionals worldwide. For example, EHECs, combined with Shigella, are responsible for the deaths of approximately 325,000 children each year and are particularly prevalent in the developing world where laboratory-based identification, common in the United States, is unavailable 1. The development and distribution of low cost, field-based, point-of-care tools to aid in the rapid identification and/or diagnosis of pathogens or disease markers could dramatically alter disease progression and patient prognosis. We have developed a tool to isolate nucleic acids and proteins from a sample by solid-phase extraction (SPE) without electricity or associated laboratory equipment 2. The isolated macromolecules can be used for diagnosis either in a forward lab or using field-based point-of-care platforms. Importantly, this method provides for the direct comparison of nucleic acid and protein data from an un-split sample, offering a confidence through corroboration of genomic and proteomic analysis. Our isolation tool utilizes the industry standard for solid-phase nucleic acid isolation, the BOOM technology, which isolates nucleic acids from a chaotropic salt solution, usually guanidine isothiocyanate, through binding to silica-based particles or filters 3. CUBRC's proprietary solid-phase extraction chemistry is used to purify protein from chaotropic salt solutions, in this case, from the waste or flow-thru following nucleic acid isolation4. By packaging well-characterized chemistries into a small, inexpensive and simple platform, we have generated a portable system for nucleic acid and protein extraction that can be performed under a variety of conditions. The isolated nucleic acids are stable and can be transported to a position where power is available for PCR amplification while the protein content can immediately be analyzed by hand held or other immunological-based assays. The rapid identification of disease markers in the field could significantly alter the patient's outcome by directing the proper course of treatment at an earlier stage of disease progression. The tool and method described are suitable for use with virtually any infectious agent and offer the user the redundancy of multi-macromolecule type analyses while simultaneously reducing their logistical burden. PMID:22635135

Electricity-free, sequential nucleic acid and protein isolation.

PubMed

Pawlowski, David R; Karalus, Richard J

2012-05-15

Traditional and emerging pathogens such as Enterohemorrhagic Escherichia coli (EHEC), Yersinia pestis, or prion-based diseases are of significant concern for governments, industries and medical professionals worldwide. For example, EHECs, combined with Shigella, are responsible for the deaths of approximately 325,000 children each year and are particularly prevalent in the developing world where laboratory-based identification, common in the United States, is unavailable (1). The development and distribution of low cost, field-based, point-of-care tools to aid in the rapid identification and/or diagnosis of pathogens or disease markers could dramatically alter disease progression and patient prognosis. We have developed a tool to isolate nucleic acids and proteins from a sample by solid-phase extraction (SPE) without electricity or associated laboratory equipment (2). The isolated macromolecules can be used for diagnosis either in a forward lab or using field-based point-of-care platforms. Importantly, this method provides for the direct comparison of nucleic acid and protein data from an un-split sample, offering a confidence through corroboration of genomic and proteomic analysis. Our isolation tool utilizes the industry standard for solid-phase nucleic acid isolation, the BOOM technology, which isolates nucleic acids from a chaotropic salt solution, usually guanidine isothiocyanate, through binding to silica-based particles or filters (3). CUBRC's proprietary solid-phase extraction chemistry is used to purify protein from chaotropic salt solutions, in this case, from the waste or flow-thru following nucleic acid isolation(4). By packaging well-characterized chemistries into a small, inexpensive and simple platform, we have generated a portable system for nucleic acid and protein extraction that can be performed under a variety of conditions. The isolated nucleic acids are stable and can be transported to a position where power is available for PCR amplification while the protein content can immediately be analyzed by hand held or other immunological-based assays. The rapid identification of disease markers in the field could significantly alter the patient's outcome by directing the proper course of treatment at an earlier stage of disease progression. The tool and method described are suitable for use with virtually any infectious agent and offer the user the redundancy of multi-macromolecule type analyses while simultaneously reducing their logistical burden.

Sorption of Cu(2+) on humic acids sequentially extracted from a sediment.

PubMed

Yang, Kun; Miao, Gangfen; Wu, Wenhao; Lin, Daohui; Pan, Bo; Wu, Fengchang; Xing, Baoshan

2015-11-01

In addition to the diverse properties of humic acids (HAs) extracted from different soils or sediments, chemical compositions, functional groups and structures of HAs extracted from a single soil or sediment could also be diverse and thus significantly affect sorption of heavy metals, which is a key process controlling the transfer, transformation and fate of heavy metals in the environment. In this study, we sequentially extracted four HA fractions from a single sediment and conducted the sorption experiments of Cu(2+) on these HA fractions. Our results showed that aromaticity and acidic group content of HA fraction decreased with increasing extraction. Earlier extracted HA fraction had higher sorption capacity and affinity for Cu(2+). There were two fractions of adsorbed Cu(2+) on HAs, i.e., ion exchanged fraction and surface bonded fraction, which can be captured mechanically by the bi-Langmuir model with good isotherm fitting. The ion exchanged fraction had larger sorption capacity but lower sorption affinity, compared with the surface bonded fraction. The dissociated carboxyl groups of HAs were responsible for both fractions of Cu(2+) sorption, due to the more Cu(2+) sorption on the earlier extracted HA fraction with more carboxyl groups and at higher pH. The intensive competition between H(+) and the exchangeable Cu(2+) could result in the decrease of ion exchanged capacity and affinity for Cu(2+) on HAs. Copyright © 2015 Elsevier Ltd. All rights reserved.

Sequential estimation and satellite data assimilation in meteorology and oceanography

NASA Technical Reports Server (NTRS)

Ghil, M.

1986-01-01

The role of dynamics in estimating the state of the atmosphere and ocean from incomplete and noisy data is discussed and the classical applications of four-dimensional data assimilation to large-scale atmospheric dynamics are presented. It is concluded that sequential updating of a forecast model with continuously incoming conventional and remote-sensing data is the most natural way of extracting the maximum amount of information from the imperfectly known dynamics, on the one hand, and the inaccurate and incomplete observations, on the other.

Eyewitness decisions in simultaneous and sequential lineups: a dual-process signal detection theory analysis.

PubMed

Meissner, Christian A; Tredoux, Colin G; Parker, Janat F; MacLin, Otto H

2005-07-01

Many eyewitness researchers have argued for the application of a sequential alternative to the traditional simultaneous lineup, given its role in decreasing false identifications of innocent suspects (sequential superiority effect). However, Ebbesen and Flowe (2002) have recently noted that sequential lineups may merely bring about a shift in response criterion, having no effect on discrimination accuracy. We explored this claim, using a method that allows signal detection theory measures to be collected from eyewitnesses. In three experiments, lineup type was factorially combined with conditions expected to influence response criterion and/or discrimination accuracy. Results were consistent with signal detection theory predictions, including that of a conservative criterion shift with the sequential presentation of lineups. In a fourth experiment, we explored the phenomenological basis for the criterion shift, using the remember-know-guess procedure. In accord with previous research, the criterion shift in sequential lineups was associated with a reduction in familiarity-based responding. It is proposed that the relative similarity between lineup members may create a context in which fluency-based processing is facilitated to a greater extent when lineup members are presented simultaneously.

One-calibrant kinetic calibration for on-site water sampling with solid-phase microextraction.

PubMed

Ouyang, Gangfeng; Cui, Shufen; Qin, Zhipei; Pawliszyn, Janusz

2009-07-15

The existing solid-phase microextraction (SPME) kinetic calibration technique, using the desorption of the preloaded standards to calibrate the extraction of the analytes, requires that the physicochemical properties of the standard should be similar to those of the analyte, which limited the application of the technique. In this study, a new method, termed the one-calibrant kinetic calibration technique, which can use the desorption of a single standard to calibrate all extracted analytes, was proposed. The theoretical considerations were validated by passive water sampling in laboratory and rapid water sampling in the field. To mimic the variety of the environment, such as temperature, turbulence, and the concentration of the analytes, the flow-through system for the generation of standard aqueous polycyclic aromatic hydrocarbons (PAHs) solution was modified. The experimental results of the passive samplings in the flow-through system illustrated that the effect of the environmental variables was successfully compensated with the kinetic calibration technique, and all extracted analytes can be calibrated through the desorption of a single calibrant. On-site water sampling with rotated SPME fibers also illustrated the feasibility of the new technique for rapid on-site sampling of hydrophobic organic pollutants in water. This technique will accelerate the application of the kinetic calibration method and also will be useful for other microextraction techniques.

System for the removal of contaminant soil-gas vapors

DOEpatents

Weidner, Jerry R.; Downs, Wayne C.; Kaser, Timothy G.; Hall, H. James

1997-01-01

A system extracts contaminated vapors from soil or other subsurface regions by using changes in barometric pressure to operate sensitive check valves that control air entry and removal from wells in the ground. The system creates an efficient subterranean flow of air through a contaminated soil plume and causes final extraction of the contaminants from the soil to ambient air above ground without any external energy sources.

System for the removal of contaminant soil-gas vapors

DOEpatents

Weidner, J.R.; Downs, W.C.; Kaser, T.G.; Hall, H.J.

1997-12-16

A system extracts contaminated vapors from soil or other subsurface regions by using changes in barometric pressure to operate sensitive check valves that control air entry and removal from wells in the ground. The system creates an efficient subterranean flow of air through a contaminated soil plume and causes final extraction of the contaminants from the soil to ambient air above ground without any external energy sources. 4 figs.

Sequential extraction of chromium, molybdenum, and vanadium in basic oxygen furnace slags.

PubMed

Spanka, Marina; Mansfeldt, Tim; Bialucha, Ruth

2018-06-02

Basic oxygen furnace slags (BOS) are by-products of basic oxygen steel production. Whereas the solubility of some elements from these slags has been well investigated, information about the mineralogy and related leaching, i.e., availability of the environmentally relevant elements chromium (Cr), molybdenum (Mo), and vanadium (V), is still lacking. The aim of this study was to investigate these issues with a modified, four-fraction-based, sequential extraction procedure (F1-F4), combined with X-ray diffraction, of two BOS. Extractants with increasing strength were used (F1 demineralized water, F2 CH 3 COOH + HCl, F3 Na 2 EDTA + NH 2 OH·HCl, and F4 HF + HNO 3 + H 2 O 2 ), and after each fraction, X-ray diffraction was performed. The recovery of Cr was moderate (66.5%) for one BOS, but significantly better (100.2%) for the other one. High recoveries were achieved for the other elements (Mo, 100.8-107.9% and V, 112.6-87.0%), indicating that the sequential extraction procedure was reliable when adapted to BOS. The results showed that Cr and Mo primarily occurred in F4, representing rather immobile elements under natural conditions, which were strongly bound into/onto Fe minerals (srebrodolskite, magnetite, hematite, or wustite). In contrast, V was more mobile with proportional higher findings in F2 and F3, and the X-ray diffraction results reveal that V was not solely bound into Ca minerals (larnite, hatrurite, kirschsteinite, and calcite), but also bound to Fe minerals. The results indicated that the total amount of recovery was a poor indicator of the availability of elements and did not correspond to the leaching of elements from BOS.

Risk assessment of trace metals in an extreme environment sediment: shallow, hypersaline, alkaline, and industrial Lake Acıgöl, Denizli, Turkey.

PubMed

Budakoglu, Murat; Karaman, Muhittin; Kumral, Mustafa; Zeytuncu, Bihter; Doner, Zeynep; Yildirim, Demet Kiran; Taşdelen, Suat; Bülbül, Ali; Gumus, Lokman

2018-02-23

The major and trace element component of 48 recent sediment samples in three distinct intervals (0-10, 10-20, and 20-30 cm) from Lake Acıgöl is described to present the current contamination levels and grift structure of detrital and evaporate mineral patterns of these sediments in this extreme saline environment. The spatial and vertical concentrations of major oxides were not uniform in the each subsurface interval. However, similar spatial distribution patterns were observed for some major element couples, due mainly to the detrital and evaporate origin of these elements. A sequential extraction procedure including five distinct steps was also performed to determine the different bonds of trace elements in the < 60-μ particulate size of recent sediments. Eleven trace elements (Ni, Fe, Cd, Pb, Cu, Zn, As, Co, Cr, Al and Mn) in nine surface and subsurface sediment samples were analyzed with chemical partitioning procedures to determine the trace element percentage loads in these different sequential extraction phases. The obtained accuracy values via comparison of the bulk trace metal loads with the total loads of five extraction steps were satisfying for the Ni, Fe, Cd, Zn, and Co. While, bulk analysis results of the Cu, Ni, and V elements have good correlation with total organic matter, organic fraction of sequential extraction characterized by Cu, As, Cd, and Pb. Shallow Lake Acıgöl sediment is characteristic with two different redox layer a) oxic upper level sediments, where trace metals are mobilized, b) reduced subsurface level, where the trace metals are precipitated.

Improved method for calibration of exchange flows for a physical transport box model of Tampa Bay, FL USA

EPA Science Inventory

Results for both sequential and simultaneous calibration of exchange flows between segments of a 10-box, one-dimensional, well-mixed, bifurcated tidal mixing model for Tampa Bay are reported. Calibrations were conducted for three model options with different mathematical expressi...

High-efficiency headspace sampling of volatile organic compounds in explosives using capillary microextraction of volatiles (CMV) coupled to gas chromatography-mass spectrometry (GC-MS).

PubMed

Fan, Wen; Almirall, José

2014-03-01

A novel geometry configuration based on sorbent-coated glass microfibers packed within a glass capillary is used to sample volatile organic compounds, dynamically, in the headspace of an open system or in a partially open system to achieve quantitative extraction of the available volatiles of explosives with negligible breakthrough. Air is sampled through the newly developed sorbent-packed 2 cm long, 2 mm diameter capillary microextraction of volatiles (CMV) and subsequently introduced into a commercially available thermal desorption probe fitted directly into a GC injection port. A sorbent coating surface area of ∼5 × 10(-2) m(2) or 5,000 times greater than that of a single solid-phase microextraction (SPME) fiber allows for fast (30 s), flow-through sampling of relatively large volumes using sampling flow rates of ∼1.5 L/min. A direct comparison of the new CMV extraction to a static (equilibrium) SPME extraction of the same headspace sample yields a 30 times improvement in sensitivity for the CMV when sampling nitroglycerine (NG), 2,4-dinitrotoluene (2,4-DNT), and diphenylamine (DPA) in a mixture containing a total mass of 500 ng of each analyte, when spiked into a liter-volume container. Calibration curves were established for all compounds studied, and the recovery was determined to be ∼1 % or better after only 1 min of sampling time. Quantitative analysis is also possible using this extraction technique when the sampling temperature, flow rate, and time are kept constant between calibration curves and the sample.

Continuous flow nanoparticle concentration using alternating current-electroosmotic flow.

PubMed

Hoettges, Kai F; McDonnell, Martin B; Hughes, Michael P

2014-02-01

Achieving real-time detection of environmental pathogens such as viruses and bacterial spores requires detectors with both rapid action and a suitable detection threshold. However, most biosensors have detection limits of an order of magnitude or more above the potential infection threshold, limiting their usefulness. This can be improved through the use of automated sample preparation techniques such as preconcentration. In this paper, we describe the use of AC electroosmosis to concentrate nanoparticles from a continuous flow. Electrodes at an optimized angle across a flow cell, and energized by a 1 kHz signal, were used to push nanoparticles to one side of a flow cell, and to extract the resulting stream with a high particle concentration from that side of the flow cell. A simple model of the behavior of particles in the flow cell has been developed, which shows good agreement with experimental results. The method indicates potential for higher concentration factors through cascading devices. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Dispersion Analysis Using Particle Tracking Simulations Through Heterogeneity Based on Outcrop Lidar Imagery

NASA Astrophysics Data System (ADS)

Klise, K. A.; Weissmann, G. S.; McKenna, S. A.; Tidwell, V. C.; Frechette, J. D.; Wawrzyniec, T. F.

2007-12-01

Solute plumes are believed to disperse in a non-Fickian manner due to small-scale heterogeneity and variable velocities that create preferential pathways. In order to accurately predict dispersion in naturally complex geologic media, the connection between heterogeneity and dispersion must be better understood. Since aquifer properties can not be measured at every location, it is common to simulate small-scale heterogeneity with random field generators based on a two-point covariance (e.g., through use of sequential simulation algorithms). While these random fields can produce preferential flow pathways, it is unknown how well the results simulate solute dispersion through natural heterogeneous media. To evaluate the influence that complex heterogeneity has on dispersion, we utilize high-resolution terrestrial lidar to identify and model lithofacies from outcrop for application in particle tracking solute transport simulations using RWHet. The lidar scan data are used to produce a lab (meter) scale two-dimensional model that captures 2-8 mm scale natural heterogeneity. Numerical simulations utilize various methods to populate the outcrop structure captured by the lidar-based image with reasonable hydraulic conductivity values. The particle tracking simulations result in residence time distributions used to evaluate the nature of dispersion through complex media. Particle tracking simulations through conductivity fields produced from the lidar images are then compared to particle tracking simulations through hydraulic conductivity fields produced from sequential simulation algorithms. Based on this comparison, the study aims to quantify the difference in dispersion when using realistic and simplified representations of aquifer heterogeneity. Sandia is a multiprogram laboratory operated by Sandia Corporation, a Lockheed Martin Company, for the United States Department of Energy's National Nuclear Security Administration under contract DE-AC04-94AL85000.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Favorito, Jessica E.; Luxton, Todd P.; Eick, Matthew J.

Selenium is a trace element found in western US soils, where ingestion of Se-accumulating plants has resulted in livestock fatalities. Therefore, a reliable understanding of Se speciation and bioavailability is critical for effective mitigation. Sequential extraction procedures (SEP) are often employed to examine Se phases and speciation in contaminated soils but may be limited by experimental conditions. We examined the validity of a SEP using X-ray absorption spectroscopy (XAS) for both whole and a sequence of extracted soils. The sequence included removal of soluble, PO4-extractable, carbonate, amorphous Fe-oxide, crystalline Fe-oxide, organic, and residual Se forms. For whole soils, XANES analysesmore » indicated Se(0) and Se(-II) predominated, with lower amounts of Se(IV) present, related to carbonates and Fe-oxides. Oxidized Se species were more elevated and residual/elemental Se was lower than previous SEP results from ICP-AES suggested. For soils from the SEP sequence, XANES results indicated only partial recovery of carbonate, Fe-oxide and organic Se. This suggests Se was incompletely removed during designated extractions, possibly due to lack of mineral solubilization or reagent specificity. Selenium fractions associated with Fe-oxides were reduced in amount or removed after using hydroxylamine HCl for most soils examined. XANES results indicate partial dissolution of solid-phases may occur during extraction processes. This study demonstrates why precautions should be taken to improve the validity of SEPs. Mineralogical and chemical characterizations should be completed prior to SEP implementation to identify extractable phases or mineral components that may influence extraction effectiveness. Sequential extraction procedures can be appropriately tailored for reliable quantification of speciation in contaminated soils.« less

A Nth-order linear algorithm for extracting diffuse correlation spectroscopy blood flow indices in heterogeneous tissues.

PubMed

Shang, Yu; Yu, Guoqiang

2014-09-29

Conventional semi-infinite analytical solutions of correlation diffusion equation may lead to errors when calculating blood flow index (BFI) from diffuse correlation spectroscopy (DCS) measurements in tissues with irregular geometries. Very recently, we created an algorithm integrating a N th-order linear model of autocorrelation function with the Monte Carlo simulation of photon migrations in homogenous tissues with arbitrary geometries for extraction of BFI (i.e., αD B ). The purpose of this study is to extend the capability of the N th-order linear algorithm for extracting BFI in heterogeneous tissues with arbitrary geometries. The previous linear algorithm was modified to extract BFIs in different types of tissues simultaneously through utilizing DCS data at multiple source-detector separations. We compared the proposed linear algorithm with the semi-infinite homogenous solution in a computer model of adult head with heterogeneous tissue layers of scalp, skull, cerebrospinal fluid, and brain. To test the capability of the linear algorithm for extracting relative changes of cerebral blood flow (rCBF) in deep brain, we assigned ten levels of αD B in the brain layer with a step decrement of 10% while maintaining αD B values constant in other layers. Simulation results demonstrate the accuracy (errors < 3%) of high-order ( N  ≥ 5) linear algorithm in extracting BFIs in different tissue layers and rCBF in deep brain. By contrast, the semi-infinite homogenous solution resulted in substantial errors in rCBF (34.5% ≤ errors ≤ 60.2%) and BFIs in different layers. The N th-order linear model simplifies data analysis, thus allowing for online data processing and displaying. Future study will test this linear algorithm in heterogeneous tissues with different levels of blood flow variations and noises.

Automated extraction of natural drainage density patterns for the conterminous United States through high performance computing

USGS Publications Warehouse

Stanislawski, Larry V.; Falgout, Jeff T.; Buttenfield, Barbara P.

2015-01-01

Hydrographic networks form an important data foundation for cartographic base mapping and for hydrologic analysis. Drainage density patterns for these networks can be derived to characterize local landscape, bedrock and climate conditions, and further inform hydrologic and geomorphological analysis by indicating areas where too few headwater channels have been extracted. But natural drainage density patterns are not consistently available in existing hydrographic data for the United States because compilation and capture criteria historically varied, along with climate, during the period of data collection over the various terrain types throughout the country. This paper demonstrates an automated workflow that is being tested in a high-performance computing environment by the U.S. Geological Survey (USGS) to map natural drainage density patterns at the 1:24,000-scale (24K) for the conterminous United States. Hydrographic network drainage patterns may be extracted from elevation data to guide corrections for existing hydrographic network data. The paper describes three stages in this workflow including data pre-processing, natural channel extraction, and generation of drainage density patterns from extracted channels. The workflow is concurrently implemented by executing procedures on multiple subbasin watersheds within the U.S. National Hydrography Dataset (NHD). Pre-processing defines parameters that are needed for the extraction process. Extraction proceeds in standard fashion: filling sinks, developing flow direction and weighted flow accumulation rasters. Drainage channels with assigned Strahler stream order are extracted within a subbasin and simplified. Drainage density patterns are then estimated with 100-meter resolution and subsequently smoothed with a low-pass filter. The extraction process is found to be of better quality in higher slope terrains. Concurrent processing through the high performance computing environment is shown to facilitate and refine the choice of drainage density extraction parameters and more readily improve extraction procedures than conventional processing.

Self-Consistent Chaotic Transport in a High-Dimensional Mean-Field Hamiltonian Map Model

DOE PAGES

Martínez-del-Río, D.; del-Castillo-Negrete, D.; Olvera, A.; ...

2015-10-30

We studied the self-consistent chaotic transport in a Hamiltonian mean-field model. This model provides a simplified description of transport in marginally stable systems including vorticity mixing in strong shear flows and electron dynamics in plasmas. Self-consistency is incorporated through a mean-field that couples all the degrees-of-freedom. The model is formulated as a large set of N coupled standard-like area-preserving twist maps in which the amplitude and phase of the perturbation, rather than being constant like in the standard map, are dynamical variables. Of particular interest is the study of the impact of periodic orbits on the chaotic transport and coherentmore » structures. Furthermore, numerical simulations show that self-consistency leads to the formation of a coherent macro-particle trapped around the elliptic fixed point of the system that appears together with an asymptotic periodic behavior of the mean field. To model this asymptotic state, we introduced a non-autonomous map that allows a detailed study of the onset of global transport. A turnstile-type transport mechanism that allows transport across instantaneous KAM invariant circles in non-autonomous systems is discussed. As a first step to understand transport, we study a special type of orbits referred to as sequential periodic orbits. Using symmetry properties we show that, through replication, high-dimensional sequential periodic orbits can be generated starting from low-dimensional periodic orbits. We show that sequential periodic orbits in the self-consistent map can be continued from trivial (uncoupled) periodic orbits of standard-like maps using numerical and asymptotic methods. Normal forms are used to describe these orbits and to find the values of the map parameters that guarantee their existence. Numerical simulations are used to verify the prediction from the asymptotic methods.« less

Self-Consistent Chaotic Transport in a High-Dimensional Mean-Field Hamiltonian Map Model

DOE Office of Scientific and Technical Information (OSTI.GOV)

Martínez-del-Río, D.; del-Castillo-Negrete, D.; Olvera, A.

We studied the self-consistent chaotic transport in a Hamiltonian mean-field model. This model provides a simplified description of transport in marginally stable systems including vorticity mixing in strong shear flows and electron dynamics in plasmas. Self-consistency is incorporated through a mean-field that couples all the degrees-of-freedom. The model is formulated as a large set of N coupled standard-like area-preserving twist maps in which the amplitude and phase of the perturbation, rather than being constant like in the standard map, are dynamical variables. Of particular interest is the study of the impact of periodic orbits on the chaotic transport and coherentmore » structures. Furthermore, numerical simulations show that self-consistency leads to the formation of a coherent macro-particle trapped around the elliptic fixed point of the system that appears together with an asymptotic periodic behavior of the mean field. To model this asymptotic state, we introduced a non-autonomous map that allows a detailed study of the onset of global transport. A turnstile-type transport mechanism that allows transport across instantaneous KAM invariant circles in non-autonomous systems is discussed. As a first step to understand transport, we study a special type of orbits referred to as sequential periodic orbits. Using symmetry properties we show that, through replication, high-dimensional sequential periodic orbits can be generated starting from low-dimensional periodic orbits. We show that sequential periodic orbits in the self-consistent map can be continued from trivial (uncoupled) periodic orbits of standard-like maps using numerical and asymptotic methods. Normal forms are used to describe these orbits and to find the values of the map parameters that guarantee their existence. Numerical simulations are used to verify the prediction from the asymptotic methods.« less

Microfluidic processing of concentrated surfactant mixtures: online SAXS, microscopy and rheology.

PubMed

Martin, Hazel P; Brooks, Nicholas J; Seddon, John M; Luckham, Paul F; Terrill, Nick J; Kowalski, Adam J; Cabral, João T

2016-02-14

We investigate the effect of microfluidic flow on the microstructure and dynamics of a model surfactant mixture, combining synchrotron Small Angle X-ray Scattering (SAXS), microscopy and rheology. A system comprising a single-chain cationic surfactant, hexadecyl trimethyl ammonium chloride (C16TAC), a short-chain alcohol (1-pentanol) and water was selected for the study due to its flow responsiveness and industrial relevance. Model flow fields, including sequential contraction-expansion (extensional) and rotational flows, were investigated and the fluid response in terms of the lamellar d-spacing, orientation and birefringence was monitored in situ, as well as the recovery processes after cessation of flow. Extensional flows are found to result in considerable d-spacing increase (from approx 59 Å to 65 Å). However, under continuous flow, swelling decreases with increasing flow velocity, eventually approaching the equilibrium values at velocities ≃2 cm s(-1). Through individual constrictions we observe the alignment of lamellae along the flow velocity, accompanied by increasing birefringence, followed by an orientation flip whereby lamellae exit perpendicularly to the flow direction. The resulting microstructures are mapped quantitatively onto the flow field in 2D with 200 μm spatial resolution. Rotational flows alone do not result in appreciable changes in lamellar spacing and flow type and magnitude evidently impact the fluid microstructure under flow, as well as upon relaxation. The findings are correlated with rheological properties measured ex situ to provide a mechanistic understanding of the effect of flow imposed by tubular processing units in the phase behavior and performance of a model surfactant system with ubiquitous applications in personal care and coating industries.

Remediation of electronic waste polluted soil using a combination of persulfate oxidation and chemical washing.

PubMed

Chen, Fu; Luo, Zhanbin; Liu, Gangjun; Yang, Yongjun; Zhang, Shaoliang; Ma, Jing

2017-12-15

Laboratory experiments were conducted to investigate the efficiency of a simultaneous chemical extraction and oxidation for removing persistent organic pollutants (POPs) and toxic metals from an actual soil polluted by the recycling activity of electronic waste. Various chemicals, including hydroxypropyl-β-cyclodextrin (HPCD), citric acid (CA) and sodium persulfate (SP) were applied synchronously with Fe 2+ activated oxidation to enhance the co-removal of both types of pollutants. It is found that the addition of HPCD can enhance POPs removal through solubilization of POPs and iron chelation; while the CA-chelated Fe 2+ activation process is effective for extracting metals and degrading residual POPs. Under the optimized reagent conditions, 69.4% Cu, 78.1% Pb, 74.6% Ni, 97.1% polychlorinated biphenyls, 93.8% polycyclic aromatic hydrocarbons, and 96.4% polybrominated diphenylethers were removed after the sequential application of SP-HPCD-Fe 2+ and SP-CA-Fe 2+ processes with a duration of 180 and 240 min, respectively. A high dehalogenation efficiency (84.8% bromine and 86.2% chlorine) is observed, suggesting the low accumulation of halogen-containing organic intermediates. The remediated soil can satisfy the national soil quality standard of China. Collectively, co-contaminated soil can be remediated with reasonable time and capital costs through simultaneous application of persulfate oxidation and chemical extraction. Copyright © 2017 Elsevier Ltd. All rights reserved.

External combustion engine having an asymmetrical CAM

NASA Astrophysics Data System (ADS)

Duva, Anthony W.

1994-11-01

An external combustion engine having an asymmetrical cam is the focus of this patent. The engine includes a combustion chamber for generating a high-pressure, energized gas from a monopropellant fuel and an even number of cylinders for receiving sequentially the energized gas through the rotary valve, the gas performing work on a piston disposed within each cylinder. The pistons transfer energy to a drive shaft through a connection to the asymmetrically shaped cam. The cam is shaped having two identical halves, each half having a power and an exhaust stroke. The identical halves provide that opposing cylinders are in thermodynamic balance, thus reducing rocking vibrations and torque pulsations. Having opposing pistons within the same thermodynamic cycle allows piston stroke to be reduced while maintaining displacement comparable to an engine having individual cycle positions. The reduced stroke diminishes gas flow velocity thus reducing flow induced noise. The power and exhaust strokes within each identical half of the cam are asymmetrical in that the power stroke is of greater duration than the exhaust stroke. The shape and length of the power stroke is optimized for increased efficiency.

Characteristics of Air Core and Surface Velocity for Water Flow in a Vortex Sediment-Extraction Chamber Measured by Using Photo Images and PTV Technique.

NASA Astrophysics Data System (ADS)

Yao, Hou Chang; Chyan Deng, Jan; Chao, Hsu Yu; Chih Yuan, Yang

2017-04-01

A vortex sediment-extraction chamber, consisted of cylindrical chamber, inflow system, bottom orifice and overflow weir, is used to separate sediment from sediment-laden water flow. A tangential inflow is introduced into a cylindrical chamber with a bottom orifice; thus, a strong vortex flow is produced there. Under actions of gravity and centrifugal force, heavier sediment particles are forced to move towards the bottom orifice, and relatively clear water flows over through the top overflow weir. The flow field in the cylindrical chamber consists of forced vortex and free vortex. When the bottom orifice is opened during the sediment-extraction process, an air core appears and changes with different settings. In this study, the air core and water surface velocity in the cylindrical chamber were measured by using a photo image process and particle tracking velocimetry (PTV), as well as numerically simulated by using a commercial software, Flow-3D.Laboratory experiments were conducted in a vortex chamber, having height of 130 cm and diameter of 48 cm. Five kinds of bottom orifice size from 1.0 cm to 3.0 cm and four kinds of inflow water discharge from 1,300cm3/s to 1,700 cm3/s were used while the inflow pipe of 3 cm in diameter was kept the same for all experiments. The characteristics of the air core and water surface velocity, and the inflow and outflow ratios under different experimental arrangements were observed and discussed so as to provide a better design and application for a vortex sediment-extraction chamber in the future.

Selective Extraction of Rare Earth Elements from Permanent Magnet Scraps with Membrane Solvent Extraction.

PubMed

Kim, Daejin; Powell, Lawrence E; Delmau, Lætitia H; Peterson, Eric S; Herchenroeder, Jim; Bhave, Ramesh R

2015-08-18

The rare earth elements (REEs) such as neodymium, praseodymium, and dysprosium were successfully recovered from commercial NdFeB magnets and industrial scrap magnets via membrane assisted solvent extraction (MSX). A hollow fiber membrane system was evaluated to extract REEs in a single step with the feed and strip solutions circulating continuously through the MSX system. The effects of several experimental variables on REE extraction such as flow rate, concentration of REEs in the feed solution, membrane configuration, and composition of acids were investigated with the MSX system. A multimembrane module configuration with REEs dissolved in aqueous nitric acid solutions showed high selectivity for REE extraction with no coextraction of non-REEs, whereas the use of aqueous hydrochloric acid solution resulted in coextraction of non-REEs due to the formation of chloroanions of non-REEs. The REE oxides were recovered from the strip solution through precipitation, drying, and annealing steps. The resulting REE oxides were characterized with XRD, SEM-EDX, and ICP-OES, demonstrating that the membrane assisted solvent extraction is capable of selectively recovering pure REEs from the industrial scrap magnets.

Flow injection spectrophotometric determination of V(V) involving on-line separation using a poly(vinylidene fluoride-co-hexafluoropropylene)-based polymer inclusion membrane.

PubMed

Yaftian, Mohammad Reza; Almeida, M Inês G S; Cattrall, Robert W; Kolev, Spas D

2018-05-01

A poly(vinylidene fluoride-co-hexafluoropropylene)-based polymer inclusion membrane (PIM) using Cyphos® IL 101 (i.e. trihexyl(tetradecyl)phosphonium chloride) as the carrier and 2-nitrophenyl octyl ether as a plasticizer in a mass ratio of 55/35/10 was employed for the on-line extractive separation of V(V) prior to its spectrophotometric determination in a flow injection analysis (FIA) system using xylenol orange as the colorimetric reagent. The selectivity of the membrane allowed the determination of V(V) in sulfate solutions in the presence of a variety of cations and anions. The interference of molybdenum(VI) was eliminated by off-line extraction using the same PIM. A univariate sequential optimization of the newly developed FIA system was conducted and under optimal conditions the system is characterized by a linear concentration range of 0.5-8.0mgL -1 , detection limit of 0.08mgL -1 and sample throughput of 4h -1 . The relative standard deviation at the 3mgL -1 level of V(V) was 2.9% based on 8 replicate determinations. The membrane was stable, which was reflected by the standard deviation value for determinations over three consecutive days (24 determinations of 3mgL -1 V(V)) of 3.6%. The newly developed FIA system was applied to the determination of V(V) in water and dietary supplements samples and a good agreement with inductively coupled plasma optical emission spectrometry was observed. Copyright © 2018 Elsevier B.V. All rights reserved.

Catalytic and electrocatalytic hydrogenolysis of brominated diphenyl ethers.

PubMed

Bonin, Pascale M L; Edwards, Patrick; Bejan, Dorin; Lo, Chun Chi; Bunce, Nigel J; Konstantinov, Alexandre D

2005-02-01

Polybrominated diphenyl ethers (PBDEs) are ubiquitous environmental contaminants due to their use as additive flame-retardants. Conventional catalytic hydrogenolysis in methanol solution and electrocatalytic hydrogenolysis in aqueous methanol were examined as methods for debrominating mono- and di-bromodiphenyl ethers, as well as a commercial penta-PBDE mixture, in each case using palladium on alumina as the catalyst. Electrocatalytic hydrogenolysis employed a divided flow-through batch cell, with reticulated vitreous carbon cathodes and IrO2/Ti dimensionally stable anodes. Both methods gave efficient sequential debromination, with essentially complete removal of bromine from the PBDEs, but the electrocatalytic method was limited by the poor solubility of PBDEs in aqueous methanol.

Deformation simulation of cells seeded on a collagen-GAG scaffold in a flow perfusion bioreactor using a sequential 3D CFD-elastostatics model.

PubMed

Jungreuthmayer, C; Jaasma, M J; Al-Munajjed, A A; Zanghellini, J; Kelly, D J; O'Brien, F J

2009-05-01

Tissue-engineered bone shows promise in meeting the huge demand for bone grafts caused by up to 4 million bone replacement procedures per year, worldwide. State-of-the-art bone tissue engineering strategies use flow perfusion bioreactors to apply biophysical stimuli to cells seeded on scaffolds and to grow tissue suitable for implantation into the patient's body. The aim of this study was to quantify the deformation of cells seeded on a collagen-GAG scaffold which was perfused by culture medium inside a flow perfusion bioreactor. Using a microCT scan of an unseeded collagen-GAG scaffold, a sequential 3D CFD-deformation model was developed. The wall shear stress and the hydrostatic wall pressure acting on the cells were computed through the use of a CFD simulation and fed into a linear elastostatics model in order to calculate the deformation of the cells. The model used numerically seeded cells of two common morphologies where cells are either attached flatly on the scaffold wall or bridging two struts of the scaffold. Our study showed that the displacement of the cells is primarily determined by the cell morphology. Although cells of both attachment profiles were subjected to the same mechanical load, cells bridging two struts experienced a deformation up to 500 times higher than cells only attached to one strut. As the scaffold's pore size determines both the mechanical load and the type of attachment, the design of an optimal scaffold must take into account the interplay of these two features and requires a design process that optimizes both parameters at the same time.

Sequential high pressure extractions applied to recover piceatannol and scirpusin B from passion fruit bagasse.

PubMed

Viganó, Juliane; Aguiar, Ana C; Moraes, Damila R; Jara, José L P; Eberlin, Marcos N; Cazarin, Cinthia B B; Maróstica, Mário R; Martínez, Julian

2016-07-01

Passion fruit seeds are currently discarded on the pulp processing but are known for their high piceatannol and scirpusin B contents. Using pressurized liquid extraction (PLE), these highly valuable phenolic compounds were efficiently extracted from defatted passion fruit bagasse (DPFB). PLE was performed using mixtures of ethanol and water (50 to 100% ethanol, w/w) as solvent, temperatures from 50 to 70°C and pressure at 10MPa. The extraction methods were compared in terms of the global yield, total phenolic content (TPC), piceatannol content and the antioxidant capacity of the extracts. The DPFB extracts were also compared with those from non-defatted passion fruit bagasse (nDPFB). Identification and quantification of piceatannol were performed using UHPLC-MS/MS. The results showed that high TPC and piceatannol content were achieved for the extracts obtained from DPFB through PLE at 70°C and using 50 and 75% ethanol as the solvent. The best PLE conditions for TPC (70°C, 75% ethanol) resulted in 55.237mgGAE/g dried and defatted bagasse, whereas PLE at 70°C and 50% ethanol achieved 18.590mg of piceatannol/g dried and defatted bagasse, and such yields were significantly higher than those obtained using conventional extraction techniques. The antioxidant capacity assays showed high correlation with the TPC (r>0.886) and piceatannol (r>0.772). The passion fruit bagasse has therefore proved to be a rich source of piceatannol and PLE showed high efficiency to recover phenolic compounds from defatted passion fruit bagasse. Copyright © 2016 Elsevier Ltd. All rights reserved.

Magnetic Partitioning Nanofluid for Rare Earth Extraction from Geothermal Fluids

DOE Office of Scientific and Technical Information (OSTI.GOV)

McGrail, Bernard P.; Thallapally, Praveen K.; Liu, Jian

Rare earth metals are critical materials in a wide variety of applications in generating and storing renewable energy and in designing more energy efficient devices. Extracting rare earth metals from geothermal brines is a very challenging problem due to the low concentrations of these elements and engineering challenges with traditional chemical separations methods involving packed sorbent beds or membranes that would impede large volumetric flow rates of geothermal fluids transitioning through the plant. We are demonstrating a simple and highly cost-effective nanofluid-based method for extracting rare earth metals from geothermal brines. Core-shell composite nanoparticles are produced that contain a magneticmore » iron oxide core surrounded by a shell made of silica or metal-organic framework (MOF) sorbent functionalized with chelating ligands selective for the rare earth elements. By introducing the nanoparticles at low concentration (≈0.05 wt%) into the geothermal brine after it passes through the plant heat exchanger, the brine is exposed to a very high concentration of chelating sites on the nanoparticles without need to pass through a large and costly traditional packed bed or membrane system where pressure drop and parasitic pumping power losses are significant issues. Instead, after a short residence time flowing with the brine, the particles are effectively separated out with an electromagnet and standard extraction methods are then applied to strip the rare earth metals from the nanoparticles, which are then recycled back to the geothermal plant. Recovery efficiency for the rare earths at ppm level has now been measured for both silica and MOF sorbents functionalized with a variety of chelating ligands. A detailed preliminary techno-economic performance analysis of extraction systems using both sorbents showed potential to generate a promising internal rate of return (IRR) up to 20%.« less

40 CFR 60.4142 - Hg allowance allocations.

Code of Federal Regulations, 2011 CFR

2011-07-01

... boiler and has equipment used to produce electricity and useful thermal energy for industrial, commercial, heating, or cooling purposes through the sequential use of energy, the total heat energy (in Btu) of the... thermal energy for industrial, commercial, heating, or cooling purposes through the sequential use of...

Separation of switchgrass bio-oil by water/organic solvent addition and pH adjustment

DOE PAGES

Park, Lydia Kyoung-Eun; Ren, Shoujie; Yiacoumi, Sotira; ...

2016-01-29

Applications of bio-oil are limited by its challenging properties including high moisture content, low pH, high viscosity, high oxygen content, and low heating value. Separation of switchgrass bio-oil components by adding water, organic solvents (hexadecane and octane), and sodium hydroxide may help to overcome these issues. Acetic acid and phenolic compounds were extracted in aqueous and organic phases, respectively. Polar chemicals, such as acetic acid, did not partition in the organic solvent phase. Acetic acid in the aqueous phase after extraction is beneficial for a microbial-electrolysis-cell application to produce hydrogen as an energy source for further hydrodeoxygenation of bio-oil. Organicmore » solvents extracted more chemicals from bio-oil in combined than in sequential extraction; however, organic solvents partitioned into the aqueous phase in combined extraction. When sodium hydroxide was added to adjust the pH of aqueous bio-oil, organic-phase precipitation occurred. As the pH was increased, a biphasic aqueous/organic dispersion was formed, and phase separation was optimized at approximately pH 6. The neutralized organic bio-oil had approximately 37% less oxygen and 100% increased heating value than the initial centrifuged bio-oil. In conclusion, the less oxygen content and increased heating value indicated a significant improvement of the bio-oil quality through neutralization.« less

Separation of switchgrass bio-oil by water/organic solvent addition and pH adjustment

DOE Office of Scientific and Technical Information (OSTI.GOV)

Park, Lydia Kyoung-Eun; Ren, Shoujie; Yiacoumi, Sotira

Applications of bio-oil are limited by its challenging properties including high moisture content, low pH, high viscosity, high oxygen content, and low heating value. Separation of switchgrass bio-oil components by adding water, organic solvents (hexadecane and octane), and sodium hydroxide may help to overcome these issues. Acetic acid and phenolic compounds were extracted in aqueous and organic phases, respectively. Polar chemicals, such as acetic acid, did not partition in the organic solvent phase. Acetic acid in the aqueous phase after extraction is beneficial for a microbial-electrolysis-cell application to produce hydrogen as an energy source for further hydrodeoxygenation of bio-oil. Organicmore » solvents extracted more chemicals from bio-oil in combined than in sequential extraction; however, organic solvents partitioned into the aqueous phase in combined extraction. When sodium hydroxide was added to adjust the pH of aqueous bio-oil, organic-phase precipitation occurred. As the pH was increased, a biphasic aqueous/organic dispersion was formed, and phase separation was optimized at approximately pH 6. The neutralized organic bio-oil had approximately 37% less oxygen and 100% increased heating value than the initial centrifuged bio-oil. In conclusion, the less oxygen content and increased heating value indicated a significant improvement of the bio-oil quality through neutralization.« less

A new method for discovering behavior patterns among animal movements

USGS Publications Warehouse

Wang, Y.; Luo, Ze; Takekawa, John Y.; Prosser, Diann J.; Xiong, Y.; Newman, S.; Xiao, X.; Batbayar, N.; Spragens, Kyle A.; Balachandran, S.; Yan, B.

2016-01-01

Advanced satellite tracking technologies enable biologists to track animal movements at fine spatial and temporal scales. The resultant data present opportunities and challenges for understanding animal behavioral mechanisms. In this paper, we develop a new method to elucidate animal movement patterns from tracking data. Here, we propose the notion of continuous behavior patterns as a concise representation of popular migration routes and underlying sequential behaviors during migration. Each stage in the pattern is characterized in terms of space (i.e., the places traversed during movements) and time (i.e. the time spent in those places); that is, the behavioral state corresponding to a stage is inferred according to the spatiotemporal and sequential context. Hence, the pattern may be interpreted predictably. We develop a candidate generation and refinement framework to derive all continuous behavior patterns from raw trajectories. In the framework, we first define the representative spots to denote the underlying potential behavioral states that are extracted from individual trajectories according to the similarity of relaxed continuous locations in certain distinct time intervals. We determine the common behaviors of multiple individuals according to the spatiotemporal proximity of representative spots and apply a projection-based extension approach to generate candidate sequential behavior sequences as candidate patterns. Finally, the candidate generation procedure is combined with a refinement procedure to derive continuous behavior patterns. We apply an ordered processing strategy to accelerate candidate refinement. The proposed patterns and discovery framework are evaluated through conceptual experiments on both real GPS-tracking and large synthetic datasets.

A new method for discovering behavior patterns among animal movements.

PubMed

Wang, Yuwei; Luo, Ze; Takekawa, John; Prosser, Diann; Xiong, Yan; Newman, Scott; Xiao, Xiangming; Batbayar, Nyambayar; Spragens, Kyle; Balachandran, Sivananinthaperumal; Yan, Baoping

Advanced satellite tracking technologies enable biologists to track animal movements at fine spatial and temporal scales. The resultant data present opportunities and challenges for understanding animal behavioral mechanisms. In this paper, we develop a new method to elucidate animal movement patterns from tracking data. Here, we propose the notion of continuous behavior patterns as a concise representation of popular migration routes and underlying sequential behaviors during migration. Each stage in the pattern is characterized in terms of space (i.e., the places traversed during movements) and time (i.e. the time spent in those places); that is, the behavioral state corresponding to a stage is inferred according to the spatiotemporal and sequential context. Hence, the pattern may be interpreted predictably. We develop a candidate generation and refinement framework to derive all continuous behavior patterns from raw trajectories. In the framework, we first define the representative spots to denote the underlying potential behavioral states that are extracted from individual trajectories according to the similarity of relaxed continuous locations in certain distinct time intervals. We determine the common behaviors of multiple individuals according to the spatiotemporal proximity of representative spots and apply a projection-based extension approach to generate candidate sequential behavior sequences as candidate patterns. Finally, the candidate generation procedure is combined with a refinement procedure to derive continuous behavior patterns. We apply an ordered processing strategy to accelerate candidate refinement. The proposed patterns and discovery framework are evaluated through conceptual experiments on both real GPS-tracking and large synthetic datasets.

A new method for discovering behavior patterns among animal movements

PubMed Central

Wang, Yuwei; Luo, Ze; Takekawa, John; Prosser, Diann; Xiong, Yan; Newman, Scott; Xiao, Xiangming; Batbayar, Nyambayar; Spragens, Kyle; Balachandran, Sivananinthaperumal; Yan, Baoping

2016-01-01

Advanced satellite tracking technologies enable biologists to track animal movements at fine spatial and temporal scales. The resultant data present opportunities and challenges for understanding animal behavioral mechanisms. In this paper, we develop a new method to elucidate animal movement patterns from tracking data. Here, we propose the notion of continuous behavior patterns as a concise representation of popular migration routes and underlying sequential behaviors during migration. Each stage in the pattern is characterized in terms of space (i.e., the places traversed during movements) and time (i.e. the time spent in those places); that is, the behavioral state corresponding to a stage is inferred according to the spatiotemporal and sequential context. Hence, the pattern may be interpreted predictably. We develop a candidate generation and refinement framework to derive all continuous behavior patterns from raw trajectories. In the framework, we first define the representative spots to denote the underlying potential behavioral states that are extracted from individual trajectories according to the similarity of relaxed continuous locations in certain distinct time intervals. We determine the common behaviors of multiple individuals according to the spatiotemporal proximity of representative spots and apply a projection-based extension approach to generate candidate sequential behavior sequences as candidate patterns. Finally, the candidate generation procedure is combined with a refinement procedure to derive continuous behavior patterns. We apply an ordered processing strategy to accelerate candidate refinement. The proposed patterns and discovery framework are evaluated through conceptual experiments on both real GPS-tracking and large synthetic datasets. PMID:27217810

A weight modification sequential method for VSC-MTDC power system state estimation

NASA Astrophysics Data System (ADS)

Yang, Xiaonan; Zhang, Hao; Li, Qiang; Guo, Ziming; Zhao, Kun; Li, Xinpeng; Han, Feng

2017-06-01

This paper presents an effective sequential approach based on weight modification for VSC-MTDC power system state estimation, called weight modification sequential method. The proposed approach simplifies the AC/DC system state estimation algorithm through modifying the weight of state quantity to keep the matrix dimension constant. The weight modification sequential method can also make the VSC-MTDC system state estimation calculation results more ccurate and increase the speed of calculation. The effectiveness of the proposed weight modification sequential method is demonstrated and validated in modified IEEE 14 bus system.

Optimization of Fibrin Glue Spray Systems for Ophthalmic Surgery

PubMed Central

Chaurasia, Shyam S.; Champakalakshmi, Ravi; Angunawela, Romesh I.; Tan, Donald T.; Mehta, Jodhbir S.

2012-01-01

Purpose To optimize fibrin glue (FG) spray for ophthalmic surgery using two spray applicators, EasySpray and DuploSpray systems, by varying the distance from point of application and the pressure/flow rate, and to compare the adhesive strength of sutured and sutureless (FG sprayed) conjunctival graft surgery in a rabbit model. Methods FG was sprayed on a 0.2 mm-thick sheet of paper using EasySpray by variously combining application distances of 2.5, 5, 7.5, and 10 cm with pressures of 10, 15, and 20 psi. DuploSpray was used at the same distances but with varying flow rates of 1 and 2 L/min. Subsequently, FG was sprayed on porcine corneas and FG thickness was analyzed by histology. In addition, adhesive strength of the conjunctival graft (0.5 × 0.5 cm) attached to the rabbit cornea by sutured and sutureless surgery (FG spray) was compared using a tension meter. Results Histology measurements revealed that the FG thickness decreased with increases in distance and pressure of spray using the EasySpray applicator on paper and porcine corneal sections. The adhesive strength of the sutured conjunctival graft (41 ± 4.85 [kilopascal] KPa) was found to be higher than the graft attached by spraying (10 ± 2.3 KPa) and the sequential addition of FG (6 ± 0.714 KPa). Conclusions The EasySpray applicator formed a uniform spread of FG at a distance-pressure combination of 5 cm and 20 psi. The conjunctival graft attached with sutures had higher adhesive strength compared with grafts glued with a spray applicator. Although the adhesive strength of FG applied through the applicator was similar to the drop-wise sequential technique, the former was more cost effective because more samples could be sprayed compared with the sequential manual technique. Translational Relevance The standardization of the spray system for the application of FG in ophthalmology will provide an economical method for delivering consistent healing results after surgery. PMID:24049702

Polyaniline-coated cigarette filters as a solid-phase extraction sorbent for the extraction and enrichment of polycyclic aromatic hydrocarbon in water samples.

PubMed

Bunkoed, Opas; Rueankaew, Thanaschaphorn; Nurerk, Piyaluk; Kanatharana, Proespichaya

2016-06-01

Polyaniline coated cigarette filters were successfully synthesized and used as a solid-phase extraction sorbent for the extraction and preconcentration of polycyclic aromatic hydrocarbons in water samples. The polyaniline helped to enhance the adsorption ability of polycyclic aromatic hydrocarbons on the sorbent through π-π interactions. The high porosity and large surface area of the cigarette filters helped to reduce backpressure and can be operated with high sample flow rate without loss of extraction efficiency. The developed sorbent was characterized by Fourier transform infrared spectroscopy and scanning electron microscopy. The parameters that affected the extraction efficiencies, i.e. polymerization time, type of desorption solvent and its volume, sample flow rate, sample volume, sample pH, ionic strength, and organic modifier were investigated. Under the optimal conditions, the method was linear over the range of 0.5-10 μg/L and a detection limit of 0.5 ng/L. This simple, rapid, and cost-effective method was successfully applied to the preconcentration of polycyclic aromatic hydrocarbons from water samples. The developed method provided a high enrichment factor with good extraction efficiency (85-98%) and a relative standard deviation <10%. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Protective effect of crataegus extract on the cardiac mechanical dysfunction in isolated perfused working rat heart.

PubMed

Nasa, Y; Hashizume, H; Hoque, A N; Abiko, Y

1993-09-01

The effect of the water-soluble fraction of Crataegus (Crataegus extract) on the cardiac mechanical and metabolic function was studied in the isolated, perfused working rat heart during ischemia and reperfusion. Ischemia (15 min) was produced by removing afterload pressure, and reperfusion (20 min) was produced by returning it to the original pressure. In the control (no drug) heart, ischemia decreased mechanical function to the lowest level, which did not recover even after the end of reperfusion. Crataegus extract (0.01 or 0.05%) was applied to the heart from 5 min before ischemia through the first 10 min after reperfusion. With the high concentration of Crataegus extract (0.05%) the mechanical function recovered during reperfusion incompletely without increasing coronary flow, but the low concentration of Crataegus extract (0.01%) did not. In the heart treated with the high concentration of Crataegus extract, the reperfusion-induced recovery of the energy metabolism was accelerated, and the level of lactate during ischemia was lower than that in the control heart, although the myocardial levels of free fatty acids during ischemia and reperfusion were not greatly affected. These results demonstrate that Crataegus extract (0.05%) has a cardioprotective effect on the ischemic-reperfused heart, and that the cardioprotective effect is not accompanied by an increase in coronary flow.

Monitoring of electrokinetic removal of heavy metals in tailing-soils using sequential extraction analysis.

PubMed

Kim, S O; Kim, K W

2001-08-17

This research focused on the monitoring of the electrokinetic removal of heavy metals from tailing-soils, and emphasizes the dependency of removal efficiencies upon their physico-chemical states, as demonstrated by the different extraction methods adopted, which included aqua regia and sequential extraction. The tailing-soils examined contained high concentrations of target metal contaminants (Cd=179mgkg(-1), Cu=207mgkg(-1), Pb=5175mgkg(-1), and Zn=7600mgkg(-1)). The removal efficiencies of the different metals were significantly influenced by their speciations, mobilities and affinities (adsorption capacities) in the soil matrix. The removal efficiencies of mobile and weakly bound fractions, such as the exchangeable fraction were more than 90% by electrokinetic treatment, but strongly bound fractions, such as the organically bound species and residual fraction were not significantly removed (less than 30% removal efficiencies). In accordance with the general sequence of mobilities of heavy metals in soils, the removal efficiencies of more mobile heavy metals (Cd, Cu, and Zn) were higher than that of less mobile heavy metal (Pb).

Sequential co-production of biodiesel and bioethanol with spent coffee grounds.

PubMed

Kwon, Eilhann E; Yi, Haakrho; Jeon, Young Jae

2013-05-01

The sequential co-production of bioethanol and biodiesel from spent coffee grounds was investigated. The direct conversion of bioethanol from spent coffee grounds was not found to be a desirable option because of the relatively slow enzymatic saccharification behavior in the presence of triglycerides and the free fatty acids (FFAs) found to exist in the raw materials. Similarly, the direct transformation of the spent coffee grounds into ethanol without first extracting lipids was not found to be a feasible alternative. However, the crude lipids extracted from the spent coffee grounds were themselves converted into fatty acid methyl ester (FAME) and fatty acid ethyl ester (FAEE) via the non-catalytic biodiesel transesterification reaction. The yields of bioethanol and biodiesel were 0.46 g g(-1) and 97.5±0.5%, which were calculated based on consumed sugar and lipids extracted from spent coffee grounds respectively. Thus, this study clearly validated our theory that spent coffee grounds could be a strong candidate for the production of bioethanol and biodiesel. Copyright © 2013 Elsevier Ltd. All rights reserved.

Fractionation study in bioleached metallurgy wastes using six-step sequential extraction.

PubMed

Krasnodebska-Ostrega, Beata; Pałdyna, Joanna; Kowalska, Joanna; Jedynak, Łukasz; Golimowski, Jerzy

2009-08-15

The stored metallurgy wastes contain residues from ore processing operations that are characterized by relatively high concentrations of heavy metals. The bioleaching process makes use of bacteria to recover elements from industrial wastes and to decrease potential risk of environmental contamination. Wastes were treated by solutions containing bacteria. In this work, the optimized six-stage sequential extraction procedure was applied for the fractionation of Ni, Cr, Fe, Mn, Cu and Zn in iron-nickel metallurgy wastes deposited in Southern Poland (Szklary). Fractionation and total concentrations of elements in wastes before and after various bioleaching treatments were studied. Analyses of the extracts were performed by ICP-MS and FAAS. To achieve the most effective bioleaching of Zn, Cr, Ni, Cu, Mn, Fe the usage of both autotrophic and heterotrophic bacteria in sequence, combined with flushing of the residue after bioleaching is required. 80-100% of total metal concentrations were mobilized after the proposed treatment. Wastes treated according to this procedure could be deposited without any risk of environmental contamination and additionally the metals could be recovered for industrial purposes.

Determinants of virtual water flows in the Mediterranean.

PubMed

Fracasso, Andrea; Sartori, Martina; Schiavo, Stefano

2016-02-01

The aim of the paper is to investigate the main determinants of the bilateral virtual water (water used in the production of a commodity or service) flows associated with international trade in agricultural goods across the Mediterranean basin. We consider the bilateral gross flows of virtual water in the area and study what export-specific and import-specific factors are significantly associated with virtual water flows. We follow a sequential approach. Through a gravity model of trade, we obtain a "refined" version of the variable we aim to explain, one that is free of the amount of flows due to pair-specific factors affecting bilateral trade flows and that fully reflects the impact of country-specific determinants of virtual water trade. A number of country-specific potential explanatory variables, ranging from water endowments to trade barriers, from per capita GDP to irrigation prices, is presented and tested. To identify the variables that help to explain the bilateral flows of virtual water, we adopt a model selection procedure based on model averaging. Our findings confirm one of the main controversial results in the literature: larger water endowments do not necessarily lead to a larger 'export' of virtual water, as one could expect. We also find some evidence that higher water irrigation prices reduce (increase) virtual water 'exports' ('imports'). Copyright © 2015 Elsevier B.V. All rights reserved.

A novel visual hardware behavioral language

NASA Technical Reports Server (NTRS)

Li, Xueqin; Cheng, H. D.

1992-01-01

Most hardware behavioral languages just use texts to describe the behavior of the desired hardware design. This is inconvenient for VLSI designers who enjoy using the schematic approach. The proposed visual hardware behavioral language has the ability to graphically express design information using visual parallel models (blocks), visual sequential models (processes) and visual data flow graphs (which consist of primitive operational icons, control icons, and Data and Synchro links). Thus, the proposed visual hardware behavioral language can not only specify hardware concurrent and sequential functionality, but can also visually expose parallelism, sequentiality, and disjointness (mutually exclusive operations) for the hardware designers. That would make the hardware designers capture the design ideas easily and explicitly using this visual hardware behavioral language.

Attention-Based Recurrent Temporal Restricted Boltzmann Machine for Radar High Resolution Range Profile Sequence Recognition.

PubMed

Zhang, Yifan; Gao, Xunzhang; Peng, Xuan; Ye, Jiaqi; Li, Xiang

2018-05-16

The High Resolution Range Profile (HRRP) recognition has attracted great concern in the field of Radar Automatic Target Recognition (RATR). However, traditional HRRP recognition methods failed to model high dimensional sequential data efficiently and have a poor anti-noise ability. To deal with these problems, a novel stochastic neural network model named Attention-based Recurrent Temporal Restricted Boltzmann Machine (ARTRBM) is proposed in this paper. RTRBM is utilized to extract discriminative features and the attention mechanism is adopted to select major features. RTRBM is efficient to model high dimensional HRRP sequences because it can extract the information of temporal and spatial correlation between adjacent HRRPs. The attention mechanism is used in sequential data recognition tasks including machine translation and relation classification, which makes the model pay more attention to the major features of recognition. Therefore, the combination of RTRBM and the attention mechanism makes our model effective for extracting more internal related features and choose the important parts of the extracted features. Additionally, the model performs well with the noise corrupted HRRP data. Experimental results on the Moving and Stationary Target Acquisition and Recognition (MSTAR) dataset show that our proposed model outperforms other traditional methods, which indicates that ARTRBM extracts, selects, and utilizes the correlation information between adjacent HRRPs effectively and is suitable for high dimensional data or noise corrupted data.

Arabinan-rich pectic polysaccharides from buriti (Mauritia flexuosa): an Amazonian edible palm fruit.

PubMed

Cantu-Jungles, Thaisa Moro; Almeida, Carolina Pierobom de; Iacomini, Marcello; Cipriani, Thales R; Cordeiro, Lucimara M C

2015-05-20

Primary cell wall polysaccharides from aqueous extract of buriti fruit pulp (Mauritia flexuosa, an exotic tropical palm) were isolated and characterized. After freeze-thaw and α-amylase treatments, extracted polysaccharides were purified by sequential ultrafiltration through membranes. Two homogeneous fractions were obtained, SBW-100R and SBW-30R (Mw of 126 kDa and 20 kDa, respectively). Monosaccharide composition, methylation and (13)C NMR analysis showed that fraction SBW-100R contained a (1 → 5)-linked arabinan, branched at O-3 and O-2 positions, linked to a type I rhamnogalacturonan. Low amounts of these polymers were also present in fraction SBW-30R according to (13)C NMR analysis and monosaccharide composition. However, a high methyl esterified homogalacturonan (HG) was present in higher proportions. These results reinforce previous findings present in literature data which indicate that pectic polysaccharides are found in high amounts in primary cell walls of palms, which are commelinid monocotyledons. Copyright © 2015 Elsevier Ltd. All rights reserved.

Sequential ensemble-based optimal design for parameter estimation: SEQUENTIAL ENSEMBLE-BASED OPTIMAL DESIGN

DOE Office of Scientific and Technical Information (OSTI.GOV)

Man, Jun; Zhang, Jiangjiang; Li, Weixuan

2016-10-01

The ensemble Kalman filter (EnKF) has been widely used in parameter estimation for hydrological models. The focus of most previous studies was to develop more efficient analysis (estimation) algorithms. On the other hand, it is intuitively understandable that a well-designed sampling (data-collection) strategy should provide more informative measurements and subsequently improve the parameter estimation. In this work, a Sequential Ensemble-based Optimal Design (SEOD) method, coupled with EnKF, information theory and sequential optimal design, is proposed to improve the performance of parameter estimation. Based on the first-order and second-order statistics, different information metrics including the Shannon entropy difference (SD), degrees ofmore » freedom for signal (DFS) and relative entropy (RE) are used to design the optimal sampling strategy, respectively. The effectiveness of the proposed method is illustrated by synthetic one-dimensional and two-dimensional unsaturated flow case studies. It is shown that the designed sampling strategies can provide more accurate parameter estimation and state prediction compared with conventional sampling strategies. Optimal sampling designs based on various information metrics perform similarly in our cases. The effect of ensemble size on the optimal design is also investigated. Overall, larger ensemble size improves the parameter estimation and convergence of optimal sampling strategy. Although the proposed method is applied to unsaturated flow problems in this study, it can be equally applied in any other hydrological problems.« less

[Studies on a sequential injection renewable surface reflectance spectrophotometric system using a microchip flow cell].

PubMed

Wang, Jian-ya; Fang, Zhao-lun

2002-02-01

A microchip flow cell was developed for flow injection renewable surface assay by reflectance spectrophotometry. The flow cell was coupled to a sequential injection system and optical fiber photometric detection system. The flow cell featured a three-layer structure. The flow channel was cut into a silicone rubber membrance which formed the middle layer, and a porous filter was inlayed across a widened section of the channel to trap microbeads introduced into the flow cell. The area of the detection window of the flow cell was approximately 3.6 mm2, the volume of the bead trapped in the flow cell was 2.2 microL, the depth of the bead layer was 600 microns. A multistrand bifurcated optical fiber was coupled with incident light, detector and flow cell. The chromogenic reaction of Cr(VI) with 1,5-diphenylcarbohydrazide (DPC) which was adsorbed on trapped Polysorb C-18 beads was used as a model reaction to optimize the flow cell design and the experimental system. The reflectance of the renewable reaction surface was monitored at 540 nm. With 100 microL sample loaded and 1.0 mL.min-1 carrier flow rate, the linear response range was 0-0.6 microgram.mL-1 Cr(VI). A detection limit (3 sigma) of 6 ng.mL-1, precision of 1.5% RSD(n = 11), and a throughput of 64 samples per hour were achieved. Considerations in system and flow cell design, the influence of depth of the bead layer, weight of beads used, and the flow rates of carrier stream on the performance were discussed.

Flow through a very porous obstacle in a shallow channel

PubMed Central

Draper, S.; Nishino, T.; Borthwick, A. G. L.

2017-01-01

A theoretical model, informed by numerical simulations based on the shallow water equations, is developed to predict the flow passing through and around a uniform porous obstacle in a shallow channel, where background friction is important. This problem is relevant to a number of practical situations, including flow through aquatic vegetation, the performance of arrays of turbines in tidal channels and hydrodynamic forces on offshore structures. To demonstrate this relevance, the theoretical model is used to (i) reinterpret core flow velocities in existing laboratory-based data for an array of emergent cylinders in shallow water emulating aquatic vegetation and (ii) reassess the optimum arrangement of tidal turbines to generate power in a tidal channel. Comparison with laboratory-based data indicates a maximum obstacle resistance (or minimum porosity) for which the present theoretical model is valid. When the obstacle resistance is above this threshold the shallow water equations do not provide an adequate representation of the flow, and the theoretical model over-predicts the core flow passing through the obstacle. The second application of the model confirms that natural bed resistance increases the power extraction potential for a partial tidal fence in a shallow channel and alters the optimum arrangement of turbines within the fence. PMID:28484321

Hepatic extraction and renal production of 3,3'-diiodothyronine and 3',5'-diiodothyronine in man.

PubMed Central

Faber, J; Faber, O K; Lund, B; Kirkegaard, C; Wahren, J

1980-01-01

The sequential deiodination of thyroxine (T4) gives rise to several iodothyronine analogs including 3,3'-diiodothyronine (3,3'-T2) and 3',5'-diiodothyronine (3',5'-T2). In vitro animal studies suggest that the liver and the kidneys are the main sites of both formation and degradation of 3,3'-T2 and 3',5'-T2. To determine the metabolism of 3,3'-T2 and 3',5'-T2 in human liver and kidneys plasma samples were obtained from (a) a brachial artery and a hepatic vein in 20 normal subjects, and from (b) a femoral artery and a renal vein in 11 normal subjects. Further, the hepatic plasma flow (a) and the renal plasma flow (b) were determined. Both plasma 3,3'-T2 and 3',5'-T2 levels were reduced in the hepatic venous blood as compared to arterial values (1.09 +/- 0.40 vs. 1.75 +/- 0.74 ng/dl (P < 0.02)) (mean +/- 1 SD). This resulted in a hepatic extraction of both, 3,3'-T2 and 3',5'-T2, which averaged 8.2 and 5.2 microgram/d, respectively. Plasma 3,3'-T2 as well as 3'5'-T2 levels were higher in the renal vein as compared to arterial values, 1.49 +/- 0.42 vs. 1.39 +/- 0.45 ng/dl (P < 0.05) and 2.35 +/- 0.83 vs. 2.09 +/- 0.81 ng/dl (P < 0.05), respectively. This positive venoarterial difference implies a net production of 3,3'-T2 and 3',5'-T2 in the kidneys of 1.2 and 3.0 microgram/d, respectively. It is concluded that the liver is an important site of 3,3'-T2 and 3',5'-T2 extraction in normal man. In contrast, the renal production of 3,3'-T2 as well as 3'5'-T2 exceeds the degradation and urinary excretion. PMID:6776146

Numerical framework for the modeling of electrokinetic flows

NASA Astrophysics Data System (ADS)

Deshpande, Manish; Ghaddar, Chahid; Gilbert, John R.; St. John, Pamela M.; Woudenberg, Timothy M.; Connell, Charles R.; Molho, Joshua; Herr, Amy; Mungal, Godfrey; Kenny, Thomas W.

1998-09-01

This paper presents a numerical framework for design-based analyses of electrokinetic flow in interconnects. Electrokinetic effects, which can be broadly divided into electrophoresis and electroosmosis, are of importance in providing a transport mechanism in microfluidic devices for both pumping and separation. Models for the electrokinetic effects can be derived and coupled to the fluid dynamic equations through appropriate source terms. In the design of practical microdevices, however, accurate coupling of the electrokinetic effects requires the knowledge of several material and physical parameters, such as the diffusivity and the mobility of the solute in the solvent. Additionally wall-based effects such as chemical binding sites might exist that affect the flow patterns. In this paper, we address some of these issues by describing a synergistic numerical/experimental process to extract the parameters required. Experiments were conducted to provide the numerical simulations with a mechanism to extract these parameters based on quantitative comparisons with each other. These parameters were then applied in predicting further experiments to validate the process. As part of this research, we have created NetFlow, a tool for micro-fluid analyses. The tool can be validated and applied in existing technologies by first creating test structures to extract representations of the physical phenomena in the device, and then applying them in the design analyses to predict correct behavior.

High metal reactivity and environmental risks at a site contaminated by glass waste.

PubMed

Augustsson, A; Åström, M; Bergbäck, B; Elert, M; Höglund, L O; Kleja, D B

2016-07-01

This study addresses the reactivity and risks of metals (Ba, Cd, Co, Cr, Cu, Ni, Pb, Zn, As and Sb) at a Swedish site with large glass waste deposits. Old glassworks sites typically have high total metal concentrations, but as the metals are mainly bound within the glass waste and considered relatively inert, environmental investigations at these kinds of sites are limited. In this study, soil and landfill samples were subjected to a sequential chemical extraction procedure. Data from batch leaching tests and groundwater upstream and downstream of the waste deposits were also interpreted. The sequential extraction revealed that metals in <2 mm soil/waste samples were largely associated with geochemically active fractions, indicating that metals are released from pristine glass and subsequently largely retained in the surrounding soil and/or on secondary mineral coatings on fine glass particles. From the approximately 12,000 m(3) of coarse glass waste at the site, almost 4000 kg of Pb is estimated to have been lost through corrosion, which, however, corresponds to only a small portion of the total amount of Pb in the waste. Metal sorption within the waste deposits or in underlying soil layers is supported by fairly low metal concentrations in groundwater. However, elevated concentrations in downstream groundwater and in leachates of batch leaching tests were observed for several metals, indicating on-going leaching. Taken together, the high metal concentrations in geochemically active forms and the high amounts of as yet uncorroded metal-rich glass, indicate considerable risks to human health and the environment. Copyright © 2016. Published by Elsevier Ltd.

Student Storytelling through Sequential Art

ERIC Educational Resources Information Center

Fay, David

2007-01-01

If you are interested in using sequential art forms such as comic books in your EFL classroom, this article is full of helpful advice. Reading sequential art is beneficial because students can work with authentic texts with real language and graphic support. Students can also apply research and cultural knowledge to the creation of their own…

Comparative anthelmintic activity investigation of selected ethno-medicinal weeds

NASA Astrophysics Data System (ADS)

Pueblos, Kirstin Rhys S.; Bajalla, Mark; Pacheco, Dixie; Ganot, Sheila; Paig, Daisy; Tapales, Radyn; Lagare, Jeanne; Quimque, Mark Tristan J.

2017-01-01

Helminth infections are one of the seriously neglected potent diseases in many parts of the world. The problems of parasitic helminthes becoming resistant to currently available anthelmintic drugs pose a challenge for the search - relying on natural products - for new and better anthelmintics. In this paper, four abundant Philippine weeds: Chrysopogon aciculatus Trin. Cyperus brevifolius Rottb., Ruellia tuberosa Linn. and Saccharum spontaneum Linn. were investigated for their anthelmintic activities to establish basis of their folkloric claim. The hexane-soluble and chloroform-soluble extracts were obtained through sequential solvent partitioning of the crude ethanolic extract of the air-dried aerial part of each plant sample. Meanwhile, the decoction was obtained from fresh aerial part of the plant samples. All extracts were then subjected to in vitro anthelmintic screening at different concentration as per method of Ghosh, et al. against African nightcrawler earthworms (Eudrillus euginiae) in which the activity of the extracts was determined by correlation with time. The anthelmintic bioassay results revealed a dose-dependent toxicity relationship. It indicated relatively low anthelmintic activities of the decoction of the four plant samples as compared to their corresponding crude ethanol extracts. Among the crude ethanol extracts, C. brevifolius (CBE) gave fastest time to bring about paralysis and death to the test organisms at all concentrations tested. For the hexane extracts, R. tuberosa (RTH) gave better activity among other plant samples. Lastly, among the chloroform-soluble extracts, both that of C. brevifolius (CBC) and R. tuberosa (RTC) comparably showed strongest anthelmintic activities at all tested concentrations, thus, exhibited best anthelmintic activity that is remarkably comparable to the positive control, Mebendazole at the highest concentration tested. In fact, CBC and RTC showed highest anthelmintic potential compared to all extracts tested in this study.

Efficacy of chlorhexidine, dexpanthenol, allantoin and chitosan gel in comparison with bicarbonate oral rinse in controlling post-interventional inflammation, pain and cicatrization in subjects undergoing dental surgery.

PubMed

Lopez-Lopez, Jose; Lope-Lopez, Jose; Jan-Pallí, Enric; lez-Navarro, Beatriz Gonzá; González-Navarro, Beatriz; Jané-Salas, Enric; Estrugo-Devesa, Albert; Milani, Massimo

2015-12-01

Reducing post-interventional inflammation and pain in odontostomatological surgery procedures, such as tooth extractions, implants or oral biopsies is a relevant clinical goal. Chlorhexidine oral rinse is commonly used with this aim. Recently a new product containing chlorhexidine, dexpanthenol, allantoin and chitosan (Bexident Post [BP]) in a gel formulation has been developed. We evaluated the efficacy of BP in controlling postsurgical inflammation and pain and in promoting cicatrization in subjects undergoing molar extractions. We conducted a prospective sequential cross-over, randomized controlled study in patients undergoing surgical removal of at least two impacted mandibular third molars (teeth numbers 38 and 48) (numbers 17 and 32 in the Universal Tooth Numbering System), in two separate sessions, to determine the effect of BP in comparison with bicarbonate (BC) oral rinse (one spoonful in 200 ml of water), both used three times daily. Each subject utilized both products in a randomized sequential manner after each tooth extraction. Primary outcomes of the study were post-procedure pain and inflammation. Secondary outcomes were analgesic pill rescue use (metamizole 1 cap every 8 hours if needed) and an assessor-blinded evaluation of cicatrization with a semi-quantitative scale (good, satisfactory and insufficient). Post-procedure pain was assessed 6 hours after tooth extraction and for seven consecutive days by means of a 10 cm visual analogue scale (VAS) (from 0: no pain to 10: extreme pain). The extent of inflammation was evaluated through metric measurements of facial perimeter using standardized anatomical reference points. A total of 47 patients (22 men and 25 women; mean age 34 years) were enrolled with a total of 94 molars extracted. Nineteen subjects applied BC as the first sequential treatment and 28 BP as the first. Before surgery no mean differences in the two treatments in inflammation measurements were observed. After surgery mean VAS pain score was similar between the two treatments in the first 6 hours (VAS score = 6.5). A marked progressive reduction in pain intensity with the use of BP was observed throughout the treatment period in comparison with BC (7 day mean scores 3.7 vs. 5.3; p = 0.0001). BP was superior to BC in reducing inflammation with -50% of the inflammation-related measurement (6 mm vs. 12 mm; p = 0.0001). Analgesic pill consumption was lower with BP in comparison with BC (13 pills vs. 24; p < 0.05). Cicatrization was scored 'good' in a higher percentage of subjects during BP use (64%) in comparison with the BC group (13%) (p = 0.0001). No serious side effects were reported with either treatment regimen. In this trial BP performed better than BC in controlling pain and inflammation in subjects undergoing dental surgery, reducing the consumption of analgesics and favoring better cicatrization.

Speciation and transformation of heavy metals during vermicomposting of animal manure.

PubMed

Lv, Baoyi; Xing, Meiyan; Yang, Jian

2016-06-01

This work was conducted to evaluate the effects of vermicomposting on the speciation and mobility of heavy metals (Zn, Pb, Cr, and Cu) in cattle dung (CD) and pig manure (PM) using tessier sequential extraction method. Results showed that the pH, total organic carbon and C/N ratio were reduced, while the electric conductivity and humic acid increased after 90days vermicomposting. Moreover, the addition of earthworm could accelerate organic stabilization in vermicomposting. The total heavy metals in final vermicompost from CD and PM were higher than the initial values and the control without worms. Sequential extraction indicated that vermicomposting decreased the migration and availability of heavy metals, and the earthworm could reduce the mobile fraction, while increase the stable fraction of heavy metals. Furthermore, these results indicated that vermicomposting played a positive role in stabilizing heavy metals in the treatment of animal manure. Copyright © 2016 Elsevier Ltd. All rights reserved.

Uranium decay daughters from isolated mines: Accumulation and sources.

PubMed

Cuvier, A; Panza, F; Pourcelot, L; Foissard, B; Cagnat, X; Prunier, J; van Beek, P; Souhaut, M; Le Roux, G

2015-11-01

This study combines in situ gamma spectrometry performed at different scales, in order to accurately locate the contamination pools, to identify the concerned radionuclides and to determine the distribution of the contaminants from soil to bearing phase scale. The potential mobility of several radionuclides is also evaluated using sequential extraction. Using this procedure, an accumulation area located downstream of a former French uranium mine and concentrating a significant fraction of radioactivity is highlighted. We report disequilibria in the U-decay chains, which are likely related to the processes implemented on the mining area. Coupling of mineralogical analyzes with sequential extraction allow us to highlight the presence of barium sulfate, which may be the carrier of the Ra-226 activities found in the residual phase (Ba(Ra)SO4). In contrast, uranium is essentially in the reducible fraction and potentially trapped in clay-iron coatings located on the surface of minerals. Copyright © 2015 Elsevier Ltd. All rights reserved.

Cadmium partition in river sediments from an area affected by mining activities.

PubMed

Vasile, Georgiana D; Vlădescu, Luminiţa

2010-08-01

In this paper, the cadmium distribution in Certej River sediments in an area seriously affected by intense mining activities has been studied. The main objective of this study was the evaluation of partition of this metal into different operational defined fractions by sequential extractions. Community Bureau of Reference (BCR) sequential extraction was used to isolate different fractions. The sediment quality was assessed both upstream and downstream the pollution input points, along the Certej River, in order to reveal a possible accumulation of cadmium in sediments and the seasonal changes in cadmium concentrations in BCR sediment phases. Our results reveal that most of the cadmium content is divided between both the soluble and iron and manganese hydrated oxide fractions. Based on total cadmium concentrations in sediments, the enrichment factors were estimated using aluminum as normalizing element and the regression curve Cd/Al corresponding to the geochemical background of the studied area.

Investigations of Cu, Pb and Zn partitioning by sequential extraction in harbour sediments after electrodialytic remediation.

PubMed

Kirkelund, Gunvor M; Ottosen, Lisbeth M; Villumsen, Arne

2010-05-01

Electrodialytic remediation was used to remove Cu, Zn and Pb from three different contaminated harbour sediments. Electrodialytic experiments lasting 2 and 4 weeks were performed and 48-86% Cu, 74-90% Zn and 62-88% Pb were removed from the different sediments and the removal increased with longer remediation time. A three step sequential extraction scheme (BCR), with an extra residual step, was used to evaluate the heavy metal distribution in the sediments before and after electrodialytic remediation. Cu was mainly associated with the oxidisable phase of the sediment, both before and after remediation. Zn and Pb were found in the exchangeable and reducible phases before remediation. Zn was still found in the exchangeable and reducible phases after remediation, whereas most Pb was removed from these phases during electrodialytic remediation. Copyright 2010 Elsevier Ltd. All rights reserved.

Determination of element affinities by density fractionation of bulk coal samples

USGS Publications Warehouse

Querol, X.; Klika, Z.; Weiss, Z.; Finkelman, R.B.; Alastuey, A.; Juan, R.; Lopez-Soler, A.; Plana, F.; Kolker, A.; Chenery, S.R.N.

2001-01-01

A review has been made of the various methods of determining major and trace element affinities for different phases, both mineral and organic in coals, citing their various strengths and weaknesses. These include mathematical deconvolution of chemical analyses, direct microanalysis, sequential extraction procedures and density fractionation. A new methodology combining density fractionation with mathematical deconvolution of chemical analyses of whole coals and their density fractions has been evaluated. These coals formed part of the IEA-Coal Research project on the Modes of Occurrence of Trace Elements in Coal. Results were compared to a previously reported sequential extraction methodology and showed good agreement for most elements. For particular elements (Be, Mo, Cu, Se and REEs) in specific coals where disagreement was found, it was concluded that the occurrence of rare trace element bearing phases may account for the discrepancy, and modifications to the general procedure must be made to account for these.

New data on the mobility of Pt emitted from catalytic converters.

PubMed

Fliegel, Daniel; Berner, Zsolt; Eckhardt, Detlef; Stüben, Doris

2004-05-01

The mobility and speciation of Pt was investigated in dust deposited in highway tunnels and in gully sediments. For this, a sequential extraction technique was used in combination with a microwave digestion procedure, followed by detection of Pt with high resolution ICP-MS. A digestion procedure using HNO(3)/HCl/H(2)O(2) was developed and its efficiency tested for environmental materials. Total Pt contents ranged from approximately 100 to 300 microg/kg. The high share of chemically mobile Pt in the tunnel dust (up to about 40%) indicates that Pt is predominantly emitted in a mobile form from the converter. The absence of a mobile fraction in the gully sediment is explained by the elution of Pt by run-off. Except for the mobile and easily mobilised fractions none of the other fractions of the sequential extraction contains Pt, neither in the dust samples nor in the gully sediment.

Structural characterization of polysaccharides from bamboo

NASA Astrophysics Data System (ADS)

Kamil, Ruzaimah Nik Mohamad; Yusuf, Nur'aini Raman; Yunus, Normawati M.; Yusup, Suzana

2014-10-01

The alkaline and water soluble polysaccharides were isolate by sequential extractions with distilled water, 60% ethanol containing 1%, 5% and 8% NaOH. The samples were prepared at 60 °C for 3 h from local bamboo. The functional group of the sample were examined using FTIR analysis. The most precipitate obtained is from using 60% ethanol containing 8% NaOH with yield of 2.6%. The former 3 residues isolated by sequential extractions with distilled water, 60% ethanol containing 1% and 5% NaOH are barely visible after filtering with cellulose filter paper. The FTIR result showed that the water-soluble polysaccharides consisted mainly of OH group, CH group, CO indicates the carbohydrate and sugar chain. The sample weight loss was slightly decreased with increasing of temperature.

Stochastic porous media modeling and high-resolution schemes for numerical simulation of subsurface immiscible fluid flow transport

NASA Astrophysics Data System (ADS)

Brantson, Eric Thompson; Ju, Binshan; Wu, Dan; Gyan, Patricia Semwaah

2018-04-01

This paper proposes stochastic petroleum porous media modeling for immiscible fluid flow simulation using Dykstra-Parson coefficient (V DP) and autocorrelation lengths to generate 2D stochastic permeability values which were also used to generate porosity fields through a linear interpolation technique based on Carman-Kozeny equation. The proposed method of permeability field generation in this study was compared to turning bands method (TBM) and uniform sampling randomization method (USRM). On the other hand, many studies have also reported that, upstream mobility weighting schemes, commonly used in conventional numerical reservoir simulators do not accurately capture immiscible displacement shocks and discontinuities through stochastically generated porous media. This can be attributed to high level of numerical smearing in first-order schemes, oftentimes misinterpreted as subsurface geological features. Therefore, this work employs high-resolution schemes of SUPERBEE flux limiter, weighted essentially non-oscillatory scheme (WENO), and monotone upstream-centered schemes for conservation laws (MUSCL) to accurately capture immiscible fluid flow transport in stochastic porous media. The high-order schemes results match well with Buckley Leverett (BL) analytical solution without any non-oscillatory solutions. The governing fluid flow equations were solved numerically using simultaneous solution (SS) technique, sequential solution (SEQ) technique and iterative implicit pressure and explicit saturation (IMPES) technique which produce acceptable numerical stability and convergence rate. A comparative and numerical examples study of flow transport through the proposed method, TBM and USRM permeability fields revealed detailed subsurface instabilities with their corresponding ultimate recovery factors. Also, the impact of autocorrelation lengths on immiscible fluid flow transport were analyzed and quantified. A finite number of lines used in the TBM resulted into visual artifact banding phenomenon unlike the proposed method and USRM. In all, the proposed permeability and porosity fields generation coupled with the numerical simulator developed will aid in developing efficient mobility control schemes to improve on poor volumetric sweep efficiency in porous media.

Increase in 4-coumaryl alcohol units during lignification in alfalfa (Medicago sativa) alters the extractability and molecular weight of lignin.

PubMed

Ziebell, Angela; Gracom, Kristen; Katahira, Rui; Chen, Fang; Pu, Yunqiao; Ragauskas, Art; Dixon, Richard A; Davis, Mark

2010-12-10

The lignin content of biomass can impact the ease and cost of biomass processing. Lignin reduction through breeding and genetic modification therefore has potential to reduce costs in biomass-processing industries (e.g. pulp and paper, forage, and lignocellulosic ethanol). We investigated compositional changes in two low-lignin alfalfa (Medicago sativa) lines with antisense down-regulation of p-coumarate 3-hydroxylase (C3H) or hydroxycinnamoyl-CoA:shikimate hydroxycinnamoyltransferase (HCT). We investigated whether the difference in reactivity during lignification of 4-coumaryl alcohol (H) monomers versus the naturally dominant sinapyl alcohol and coniferyl alcohol lignin monomers alters the lignin structure. Sequential base extraction readily reduced the H monomer content of the transgenic lines, leaving a residual lignin greatly enriched in H subunits; the extraction profile highlighted the difference between the control and transgenic lines. Gel permeation chromatography of isolated ball-milled lignin indicated significant changes in the weight average molecular weight distribution of the control versus transgenic lines (CTR1a, 6000; C3H4a, 5500; C3H9a, 4000; and HCT30a, 4000).

Formation of iron nanoparticles and increase in iron reactivity in mineral dust during simulated cloud processing.

PubMed

Shi, Zongbo; Krom, Michael D; Bonneville, Steeve; Baker, Alex R; Jickells, Timothy D; Benning, Liane G

2009-09-01

The formation of iron (Fe) nanoperticles and increase in Fe reactivity in mineral dust during simulated cloud processing was investigated using high-resolution microscopy and chemical extraction methods. Cloud processing of dust was experimentally simulated via an alternation of acidic (pH 2) and circumneutral conditions (pH 5-6) over periods of 24 h each on presieved (<20 microm) Saharan soil and goethite suspensions. Microscopic analyses of the processed soil and goethite samples reveal the neo-formation of Fe-rich nanoparticle aggregates, which were not found initially. Similar Fe-rich nanoparticles were also observed in wet-deposited Saharen dusts from the western Mediterranean but not in dry-deposited dust from the eastern Mediterranean. Sequential Fe extraction of the soil samples indicated an increase in the proportion of chemically reactive Fe extractable by an ascorbate solution after simulated cloud processing. In addition, the sequential extractions on the Mediterranean dust samples revealed a higher content of reactive Fe in the wet-deposited dust compared to that of the dry-deposited dust These results suggestthat large variations of pH commonly reported in aerosol and cloud waters can trigger neo-formation of nanosize Fe particles and an increase in Fe reactivity in the dust

Applications of derivatization reactions to trace organic compounds during sample preparation based on pressurized liquid extraction.

PubMed

Carro, Antonia M; González, Paula; Lorenzo, Rosa A

2013-06-28

Pressurized liquid extraction (PLE) is an exhaustive technique used for the extraction of analytes from solid samples. Temperature, pressure, solvent type and volume, and the addition of other reagents notably influence the efficiency of the extraction. The analytical applications of this technique can be improved by coupling with appropriate derivatization reactions. The aim of this review is to discuss the recent applications of the sequential combination of PLE with derivatization and the approaches that involve simultaneous extraction and in situ derivatization. The potential of the latest developments to the trace analysis of environmental, food and biological samples is also analyzed. Copyright © 2013 Elsevier B.V. All rights reserved.

A Multi-Disciplinary Approach to Remote Sensing through Low-Cost UAVs.

PubMed

Calvario, Gabriela; Sierra, Basilio; Alarcón, Teresa E; Hernandez, Carmen; Dalmau, Oscar

2017-06-16

The use of Unmanned Aerial Vehicles (UAVs) based on remote sensing has generated low cost monitoring, since the data can be acquired quickly and easily. This paper reports the experience related to agave crop analysis with a low cost UAV. The data were processed by traditional photogrammetric flow and data extraction techniques were applied to extract new layers and separate the agave plants from weeds and other elements of the environment. Our proposal combines elements of photogrammetry, computer vision, data mining, geomatics and computer science. This fusion leads to very interesting results in agave control. This paper aims to demonstrate the potential of UAV monitoring in agave crops and the importance of information processing with reliable data flow.

A Multi-Disciplinary Approach to Remote Sensing through Low-Cost UAVs

PubMed Central

Calvario, Gabriela; Sierra, Basilio; Alarcón, Teresa E.; Hernandez, Carmen; Dalmau, Oscar

2017-01-01

The use of Unmanned Aerial Vehicles (UAVs) based on remote sensing has generated low cost monitoring, since the data can be acquired quickly and easily. This paper reports the experience related to agave crop analysis with a low cost UAV. The data were processed by traditional photogrammetric flow and data extraction techniques were applied to extract new layers and separate the agave plants from weeds and other elements of the environment. Our proposal combines elements of photogrammetry, computer vision, data mining, geomatics and computer science. This fusion leads to very interesting results in agave control. This paper aims to demonstrate the potential of UAV monitoring in agave crops and the importance of information processing with reliable data flow. PMID:28621740

High-Order Multioperator Compact Schemes for Numerical Simulation of Unsteady Subsonic Airfoil Flow

NASA Astrophysics Data System (ADS)

Savel'ev, A. D.

2018-02-01

On the basis of high-order schemes, the viscous gas flow over the NACA2212 airfoil is numerically simulated at a free-stream Mach number of 0.3 and Reynolds numbers ranging from 103 to 107. Flow regimes sequentially varying due to variations in the free-stream viscosity are considered. Vortex structures developing on the airfoil surface are investigated, and a physical interpretation of this phenomenon is given.

Neuromuscular disease classification system

NASA Astrophysics Data System (ADS)

Sáez, Aurora; Acha, Begoña; Montero-Sánchez, Adoración; Rivas, Eloy; Escudero, Luis M.; Serrano, Carmen

2013-06-01

Diagnosis of neuromuscular diseases is based on subjective visual assessment of biopsies from patients by the pathologist specialist. A system for objective analysis and classification of muscular dystrophies and neurogenic atrophies through muscle biopsy images of fluorescence microscopy is presented. The procedure starts with an accurate segmentation of the muscle fibers using mathematical morphology and a watershed transform. A feature extraction step is carried out in two parts: 24 features that pathologists take into account to diagnose the diseases and 58 structural features that the human eye cannot see, based on the assumption that the biopsy is considered as a graph, where the nodes are represented by each fiber, and two nodes are connected if two fibers are adjacent. A feature selection using sequential forward selection and sequential backward selection methods, a classification using a Fuzzy ARTMAP neural network, and a study of grading the severity are performed on these two sets of features. A database consisting of 91 images was used: 71 images for the training step and 20 as the test. A classification error of 0% was obtained. It is concluded that the addition of features undetectable by the human visual inspection improves the categorization of atrophic patterns.

Simultaneous diamagnetic and magnetic particle trapping in ferrofluid microflows via a single permanent magnet

PubMed Central

Zhou, Yilong; Kumar, Dhileep Thanjavur; Lu, Xinyu; Kale, Akshay; DuBose, John; Song, Yongxin; Wang, Junsheng; Li, Dongqing; Xuan, Xiangchun

2015-01-01

Trapping and preconcentrating particles and cells for enhanced detection and analysis are often essential in many chemical and biological applications. Existing methods for diamagnetic particle trapping require the placement of one or multiple pairs of magnets nearby the particle flowing channel. The strong attractive or repulsive force between the magnets makes it difficult to align and place them close enough to the channel, which not only complicates the device fabrication but also restricts the particle trapping performance. This work demonstrates for the first time the use of a single permanent magnet to simultaneously trap diamagnetic and magnetic particles in ferrofluid flows through a T-shaped microchannel. The two types of particles are preconcentrated to distinct locations of the T-junction due to the induced negative and positive magnetophoretic motions, respectively. Moreover, they can be sequentially released from their respective trapping spots by simply increasing the ferrofluid flow rate. In addition, a three-dimensional numerical model is developed, which predicts with a reasonable agreement the trajectories of diamagnetic and magnetic particles as well as the buildup of ferrofluid nanoparticles. PMID:26221197

Simultaneous diamagnetic and magnetic particle trapping in ferrofluid microflows via a single permanent magnet.

PubMed

Zhou, Yilong; Kumar, Dhileep Thanjavur; Lu, Xinyu; Kale, Akshay; DuBose, John; Song, Yongxin; Wang, Junsheng; Li, Dongqing; Xuan, Xiangchun

2015-07-01

Trapping and preconcentrating particles and cells for enhanced detection and analysis are often essential in many chemical and biological applications. Existing methods for diamagnetic particle trapping require the placement of one or multiple pairs of magnets nearby the particle flowing channel. The strong attractive or repulsive force between the magnets makes it difficult to align and place them close enough to the channel, which not only complicates the device fabrication but also restricts the particle trapping performance. This work demonstrates for the first time the use of a single permanent magnet to simultaneously trap diamagnetic and magnetic particles in ferrofluid flows through a T-shaped microchannel. The two types of particles are preconcentrated to distinct locations of the T-junction due to the induced negative and positive magnetophoretic motions, respectively. Moreover, they can be sequentially released from their respective trapping spots by simply increasing the ferrofluid flow rate. In addition, a three-dimensional numerical model is developed, which predicts with a reasonable agreement the trajectories of diamagnetic and magnetic particles as well as the buildup of ferrofluid nanoparticles.

Architecture for Absorption Based Heaters

DOE Office of Scientific and Technical Information (OSTI.GOV)

Moghaddam, Saeed; Chugh, Devesh

An absorption based heater is constructed on a fluid barrier heat exchanging plate such that it requires little space in a structure. The absorption based heater has a desorber, heat exchanger, and absorber sequentially placed on the fluid barrier heat exchanging plate. The vapor exchange faces of the desorber and the absorber are covered by a vapor permeable membrane that is permeable to a refrigerant vapor but impermeable to an absorbent. A process fluid flows on the side of the fluid barrier heat exchanging plate opposite the vapor exchange face through the absorber and subsequently through the heat exchanger. Themore » absorption based heater can include a second plate with a condenser situated parallel to the fluid barrier heat exchanging plate and opposing the desorber for condensation of the refrigerant for additional heating of the process fluid.« less

Effect of nicergoline on cerebral blood flow

PubMed Central

Iliff, L. D.; Boulay, G. H. Du; Marshall, John; Russell, R. W. Ross; Symon, Lindsay

1977-01-01

Cerebral blood flow (CBF) was measured before and after intravenous injection of the cerebral vasodilator nicergoline in 13 patients with cerebrovascular disease. CBF increased in seven. The possibility that the effect of the drug in the remainder may have been masked by a fall of CBF which occurs during sequential measurement of patients at rest is discussed. PMID:925694

CONTINUOUS DISSOLVER EXTRACTOR FOR PROCESSING METAL

DOEpatents

Lemon, R.B.; Buckham, J.A.

1959-02-01

An apparatus is presented for the continuous dissolution of metal slugs in an aqueous acid and sequential continuous extraction of selected metal values from the acid solution by counter-current contact with an organic solvent. The apparatus comprises a cylindrical tank divided into upper and lower sections. Dissolution of the metal slug takes place in the lower section and the solution so produced is continuously fed to the topmost plate of the upper extraction section. An immiscible organic extractant is continuously passed by a pulsing pump into the lowermost unit of the extraction section. Suitable piping and valving permits of removing the aqueous raffinate solution from the lowermost portion of the extraction section, and simultaneous removal of organic solvent extractant containing the desired product from the uppermost portion of the extraction section.

Geochemical Transformation of Cadmium (Cd) from Creek to Paddy Fields in W Thailand

NASA Astrophysics Data System (ADS)

Kosolsaksakul, Peerapat; Graham, Margaret; Farmer, John

2013-04-01

Extensive Cd contamination of paddy soils in Tak Province, western Thailand, a consequence of Zn mining activities, was first established in 2005 and medical studies showed that the health of local communities was being impaired. Mae Tao, Tak Province, comprising many paddy fields and irrigation canals, has been selected for this study of the geochemical transformation of Cd from the contamination source in the mountainous region to the east of the study site through the community irrigation system to the paddy soils. The aim of this research is to (i) investigate the geochemical transformation of Cd as it is transported from the main irrigation creek through the canals and to the paddy fields, (ii) assess the availability of Cd to rice plants, which may be affected by both chemical and physical factors, and (iii) trial some practical treatments to minimise Cd concentrations in rice grains. Soils, irrigation canal sediments and water samples were collected during the dry season and at the onset of the rainy season. Rice samples were collected at harvesting time and samples of soil fertiliser were also obtained. Water samples were filtered, ultrafiltered and analysed by ICP-MS whilst sub-samples of dried, ground soils and sediments were first subjected to micro-wave assisted acid digestion (modified US EPA method 3052). XRD and SEM-EDX methods were used for mineralogical characterisation and selective chemical extractions have assisted in the characterisation of solid phase Cd associations. Soil Cd concentrations were in the range 2.5-87.6 µg g-1, with higher values being obtained for fields furthest from the main creek. Although current irrigation water Cd inputs are low (mean 1.9 μg L-1; flood period), high loads of suspended particles still contribute additional Cd (4.2-9.8 µg L-1) to the paddy fields. For bioavailability assessment by a 3-step BCR sequential extraction, 70-90% Cd was in the exchangeable; HOAc-extractable fraction. That indicated that most of the Cd was in water soluble, exchangeable and carbonate-bound forms. For the fields with highest Cd concentration, SEM-EDX analysis identified two forms of Cd, i.e. Cd-Clay and Cd-CaCO3, in good agreement with the sequential extraction data. The predominance of easily extractable forms in the paddy field soils suggests that Cd may be readily absorbed by the rice plants. After harvesting, the Cd concentration in rice grains ranged from 0.05-4.0 µg g-1 and the concentration trends across the group of 18 fields matched well with the soil Cd data. Rice from nine out of the 18 fields contained Cd at greater than the safe level of 0.4 µg g-1.

Transport of Sr 2+ and SrEDTA 2- in partially-saturated and heterogeneous sediments

NASA Astrophysics Data System (ADS)

Pace, M. N.; Mayes, M. A.; Jardine, P. M.; McKay, L. D.; Yin, X. L.; Mehlhorn, T. L.; Liu, Q.; Gürleyük, H.

2007-05-01

Strontium-90 has migrated deep into the unsaturated subsurface beneath leaking storage tanks in the Waste Management Areas (WMA) at the U.S. Department of Energy's (DOE) Hanford Reservation. Faster than expected transport of contaminants in the vadose zone is typically attributed to either physical hydrologic processes such as development of preferential flow pathways, or to geochemical processes such as the formation of stable, anionic complexes with organic chelates, e.g., ethylenediaminetetraacetic acid (EDTA). The goal of this paper is to determine whether hydrological processes in the Hanford sediments can influence the geochemistry of the system and hence control transport of Sr 2+ and SrEDTA 2-. The study used batch isotherms, saturated packed column experiments, and an unsaturated transport experiment in an undisturbed core. Isotherms and repacked column experiments suggested that the SrEDTA 2- complex was unstable in the presence of Hanford sediments, resulting in dissociation and transport of Sr 2+ as a divalent cation. A decrease in sorption with increasing solid:solution ratio for Sr 2+ and SrEDTA 2- suggested mineral dissolution resulted in competition for sorption sites and the formation of stable aqueous complexes. This was confirmed by detection of MgEDTA 2-, MnEDTA 2-, PbEDTA 2-, and unidentified Sr and Ca complexes. Displacement of Sr 2+ through a partially-saturated undisturbed core resulted in less retardation and more irreversible sorption than was observed in the saturated repacked columns, and model results suggested a significant reservoir (49%) of immobile water was present during transport through the heterogeneous layered sediments. The undisturbed core was subsequently disassembled along distinct bedding planes and subjected to sequential extractions. Strontium was unequally distributed between carbonates (49%), ion exchange sites (37%), and the oxide (14%) fraction. An inverse relationship between mass wetness and Sr suggested that sandy sediments of low water content constituted the immobile flow regime. Our results suggested that the sequestration of Sr 2+ in partially-saturated, heterogeneous sediments was most likely due to the formation of immobile water in drier regions having low hydraulic conductivities.

Visualization and Hierarchical Analysis of Flow in Discrete Fracture Network Models

NASA Astrophysics Data System (ADS)

Aldrich, G. A.; Gable, C. W.; Painter, S. L.; Makedonska, N.; Hamann, B.; Woodring, J.

2013-12-01

Flow and transport in low permeability fractured rock is primary in interconnected fracture networks. Prediction and characterization of flow and transport in fractured rock has important implications in underground repositories for hazardous materials (eg. nuclear and chemical waste), contaminant migration and remediation, groundwater resource management, and hydrocarbon extraction. We have developed methods to explicitly model flow in discrete fracture networks and track flow paths using passive particle tracking algorithms. Visualization and analysis of particle trajectory through the fracture network is important to understanding fracture connectivity, flow patterns, potential contaminant pathways and fast paths through the network. However, occlusion due to the large number of highly tessellated and intersecting fracture polygons preclude the effective use of traditional visualization methods. We would also like quantitative analysis methods to characterize the trajectory of a large number of particle paths. We have solved these problems by defining a hierarchal flow network representing the topology of particle flow through the fracture network. This approach allows us to analyses the flow and the dynamics of the system as a whole. We are able to easily query the flow network, and use paint-and-link style framework to filter the fracture geometry and particle traces based on the flow analytics. This allows us to greatly reduce occlusion while emphasizing salient features such as the principal transport pathways. Examples are shown that demonstrate the methodology and highlight how use of this new method allows quantitative analysis and characterization of flow and transport in a number of representative fracture networks.

A new perspective of using sequential extraction: To predict the deficiency of trace elements during anaerobic digestion.

PubMed

Cai, Yafan; Wang, Jungang; Zhao, Yubin; Zhao, Xiaoling; Zheng, Zehui; Wen, Boting; Cui, Zongjun; Wang, Xiaofen

2018-09-01

Trace elements were commonly used as additives to facilitate anaerobic digestion. However, their addition is often blind because of the complexity of reaction conditions, which has impeded their widespread application. Therefore, this study was conducted to evaluate deficiencies in trace elements during anaerobic digestion by establishing relationships between changes in trace element bioavailability (the degree to which elements are available for interaction with biological systems) and digestion performance. To accomplish this, two batch experiments were conducted. In the first, sequential extraction was used to detect changes in trace element fractions and then to evaluate trace element bioavailability in the whole digestion cycle. In the second batch experiment, trace elements (Co, Fe, Cu, Zn, Mn, Mo and Se) were added to the reaction system at three concentrations (low, medium and high) and their effects were monitored. The results showed that sequential extraction was a suitable method for assessment of the bioavailability of trace elements (appropriate coefficient of variation and recovery rate). The results revealed that Se had the highest (44.2%-70.9%) bioavailability, while Fe had the lowest (1.7%-3.0%). A lack of trace elements was not directly related to their absolute bioavailability, but was instead associated with changes in their bioavailability throughout the digestion cycle. Trace elements were insufficient when their bioavailability was steady or increased over the digestion cycle. These results indicate that changes in trace element bioavailability during the digestion cycle can be used to predict their deficiency. Copyright © 2018 Elsevier Ltd. All rights reserved.

The added value of mifepristone to non-surgical treatment regimens for uterine evacuation in case of early pregnancy failure: a systematic review of the literature.

PubMed

van den Berg, Joyce; Gordon, Bernardus B M; Snijders, Marcus P M L; Vandenbussche, Frank P H A; Coppus, Sjors F P J

2015-12-01

Early pregnancy failure (EPF) is a common complication of pregnancy. Surgical intervention carries a risk of complications and, therefore, medical treatment appears to be a safe alternative. Unfortunately, the current medical treatment with misoprostol alone has complete evacuation rates between 53% and 87%. Some reports suggest that sequential treatment with mifepristone and misoprostol leads to higher success rates than misoprostol alone. To evaluate the added value of mifepristone to current non-surgical treatment regimens in women with EPF we performed a systematic literature search. Electronic databases were searched: PubMed, Cochrane Library, Current Controlled Trials, and ClinicalTrials.gov. Clinical studies, both randomised and non-randomised trials, reporting on the added value of mifepristone to current non-surgical treatment regimens in women with EPF were included. Data of sixteen studies were extracted using a data extraction sheet (based on the Cochrane Consumers and Communication Review Group's data extraction template). The methodological quality was assessed using the Cochrane Collaboration Risk of Bias tool. In five randomised and eleven non-randomised trials, success rates of sequential treatment with mifepristone and misoprostol in case of EPF varied between 52% and 95%. Large heterogeneity existed in treatment regimens and comparators between studies. The existing evidence is insufficient to draw firm conclusions about the added value of mifepristone to misoprostol alone. A sufficiently powered randomised, double blinded placebo-controlled trial is urgently required to test whether, in EPF, the sequential combination of mifepristone with misoprostol is superior to misoprostol only. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

MUTAGENIC PROPERTIES OF RIVER WATERS FLOWING THROUGH BIG CITY AREAS IN NORTH AMERICA

EPA Science Inventory

The hanging technique using Blue rayon, which specifically adsorbs mutagens with multicyclic planer structures, has advantages over the conventional method of bringing-large volumes of water back to the laboratory for extraction. Therefore, the analysis of many samples from remot...

Chiral liquid chromatography-mass spectrometry (LC-MS/MS) method development for the detection of salbutamol in urine samples.

PubMed

Chan, Sue Hay; Lee, Warren; Asmawi, Mohd Zaini; Tan, Soo Choon

2016-07-01

A sequential solid-phase extraction (SPE) method was developed and validated using liquid chromatography-electrospray ionization tandem mass spectrometry (LC-ESI-MS/MS) for the detection and quantification of salbutamol enantiomers in porcine urine. Porcine urine samples were hydrolysed with β-glucuronidase/arylsulfatase from Helix pomatia and then subjected to a double solid-phase extraction (SPE) first using the Abs-Elut Nexus SPE and then followed by the Bond Elut Phenylboronic Acid (PBA) SPE. The salbutamol enantiomers were separated using the Astec CHIROBIOTIC™ T HPLC column (3.0mm×100mm; 5μm) maintained at 15°C with a 15min isocratic run at a flow rate of 0.4mL/min. The mobile phase constituted of 5mM ammonium formate in methanol. Salbutamol and salbutamol-tert-butyl-d9 (internal standard, IS) was monitored and quantified with the multiple reaction monitoring (MRM) mode. The method showed good linearity for the range of 0.1-10ng/mL with limit of quantification at 0.3ng/mL. Analysis of the QC samples showed intra- and inter-assay precisions to be less than 5.04%, and recovery ranging from 83.82 to 102.33%. Copyright © 2016 Elsevier B.V. All rights reserved.

Multiscale methods for gore curvature calculations from FSI modeling of spacecraft parachutes

NASA Astrophysics Data System (ADS)

Takizawa, Kenji; Tezduyar, Tayfun E.; Kolesar, Ryan; Boswell, Cody; Kanai, Taro; Montel, Kenneth

2014-12-01

There are now some sophisticated and powerful methods for computer modeling of parachutes. These methods are capable of addressing some of the most formidable computational challenges encountered in parachute modeling, including fluid-structure interaction (FSI) between the parachute and air flow, design complexities such as those seen in spacecraft parachutes, and operational complexities such as use in clusters and disreefing. One should be able to extract from a reliable full-scale parachute modeling any data or analysis needed. In some cases, however, the parachute engineers may want to perform quickly an extended or repetitive analysis with methods based on simplified models. Some of the data needed by a simplified model can very effectively be extracted from a full-scale computer modeling that serves as a pilot. A good example of such data is the circumferential curvature of a parachute gore, where a gore is the slice of the parachute canopy between two radial reinforcement cables running from the parachute vent to the skirt. We present the multiscale methods we devised for gore curvature calculation from FSI modeling of spacecraft parachutes. The methods include those based on the multiscale sequentially-coupled FSI technique and using NURBS meshes. We show how the methods work for the fully-open and two reefed stages of the Orion spacecraft main and drogue parachutes.

Better together: reduced compliance after sequential versus simultaneous bilateral hearing aids fitting.

PubMed

Lavie, Limor; Banai, Karen; Attias, Joseph; Karni, Avi

2014-03-01

The purpose of this study was to determine the effects of sequential versus simultaneous bilateral hearing aids fitting on patient compliance. Thirty-six older adults with hearing impairment participated in this study. Twelve were fitted with bilateral hearing aids simultaneously. The remaining participants were fitted sequentially: One hearing aid (to the left or to the right ear) was used initially; 1 month later, the other ear was also fitted with a hearing aid for bilateral use. Self-reports on usefulness and compliance were elicited after the first and second months of hearing aid use. In addition, the number of hours the hearing aids were used was extracted from the data loggings of each device. Simultaneous fitting resulted in high levels of compliance and consistent usage throughout the study period. Sequential fitting resulted in abrupt reduction in compliance and hours of use once the second hearing aid was added, both in the clinical scoring and in the data loggings. Simultaneous fitting of bilateral hearing aids results in better compliance compared with sequential fitting. The addition of a second hearing aid after a relatively short period of monaural use may lead to inconsistent use of both hearing aids.

A Simulation-Optimization Model for the Management of Seawater Intrusion

NASA Astrophysics Data System (ADS)

Stanko, Z.; Nishikawa, T.

2012-12-01

Seawater intrusion is a common problem in coastal aquifers where excessive groundwater pumping can lead to chloride contamination of a freshwater resource. Simulation-optimization techniques have been developed to determine optimal management strategies while mitigating seawater intrusion. The simulation models are often density-independent groundwater-flow models that may assume a sharp interface and/or use equivalent freshwater heads. The optimization methods are often linear-programming (LP) based techniques that that require simplifications of the real-world system. However, seawater intrusion is a highly nonlinear, density-dependent flow and transport problem, which requires the use of nonlinear-programming (NLP) or global-optimization (GO) techniques. NLP approaches are difficult because of the need for gradient information; therefore, we have chosen a GO technique for this study. Specifically, we have coupled a multi-objective genetic algorithm (GA) with a density-dependent groundwater-flow and transport model to simulate and identify strategies that optimally manage seawater intrusion. GA is a heuristic approach, often chosen when seeking optimal solutions to highly complex and nonlinear problems where LP or NLP methods cannot be applied. The GA utilized in this study is the Epsilon-Nondominated Sorted Genetic Algorithm II (ɛ-NSGAII), which can approximate a pareto-optimal front between competing objectives. This algorithm has several key features: real and/or binary variable capabilities; an efficient sorting scheme; preservation and diversity of good solutions; dynamic population sizing; constraint handling; parallelizable implementation; and user controlled precision for each objective. The simulation model is SEAWAT, the USGS model that couples MODFLOW with MT3DMS for variable-density flow and transport. ɛ-NSGAII and SEAWAT were efficiently linked together through a C-Fortran interface. The simulation-optimization model was first tested by using a published density-independent flow model test case that was originally solved using a sequential LP method with the USGS's Ground-Water Management Process (GWM). For the problem formulation, the objective is to maximize net groundwater extraction, subject to head and head-gradient constraints. The decision variables are pumping rates at fixed wells and the system's state is represented with freshwater hydraulic head. The results of the proposed algorithm were similar to the published results (within 1%); discrepancies may be attributed to differences in the simulators and inherent differences between LP and GA. The GWM test case was then extended to a density-dependent flow and transport version. As formulated, the optimization problem is infeasible because of the density effects on hydraulic head. Therefore, the sum of the squared constraint violation (SSC) was used as a second objective. The result is a pareto curve showing optimal pumping rates versus the SSC. Analysis of this curve indicates that a similar net-extraction rate to the test case can be obtained with a minor violation in vertical head-gradient constraints. This study shows that a coupled ɛ-NSGAII/SEAWAT model can be used for the management of groundwater seawater intrusion. In the future, the proposed methodology will be applied to a real-world seawater intrusion and resource management problem for Santa Barbara, CA.

An automated system for liquid-liquid extraction in monosegmented flow analysis

PubMed Central

Facchin, Ileana; Pasquini, Celio

1997-01-01

An automated system to perform liquid-liquid extraction in monosegmented flow analysis is described. The system is controlled by a microcomputer that can track the localization of the aqueous monosegmented sample in the manifold. Optical switches are employed to sense the gas-liquid interface of the air bubbles that define the monosegment. The logical level changes, generated by the switches, are flagged by the computer through a home-made interface that also contains the analogue-to-digital converter for signal acquisition. The sequence of operations, necessary for a single extraction or for concentration of the analyte in the organic phase, is triggered by these logical transitions. The system was evaluated for extraction of Cd(II), Cu(II) and Zn(II) and concentration of Cd(II) from aqueous solutions at pH 9.9 (NH3/NH4Cl buffer) into chloroform containing PAN (1-(2-pyridylazo)-2-naphthol) . The results show a mean repeatability of 3% (rsd) for a 2.0 mg l-1 Cd(II) solution and a linear increase of the concentration factor for a 0.5mg l-1 Cd(II) solution observed for up to nine extraction cycles. PMID:18924792

Evaluation of the Sequential Spot Sampler (S3) for time-resolved measurement of PM2.5 sulfate and nitrate through lab and field measurements

NASA Astrophysics Data System (ADS)

Hecobian, A.; Evanoski-Cole, A.; Eiguren-Fernandez, A.; Sullivan, A. P.; Lewis, G. S.; Hering, S. V.; Collett, J. L., Jr.

2016-02-01

The Sequential Spot Sampler (S3), a newly developed instrument to collect aerosols for time-resolved chemical composition measurements, was evaluated in the laboratory and field for the measurement of particulate sulfate and nitrate. The S3 uses a multi-temperature condensation growth tube to grow individual aerosols to droplets which are then deposited as a ˜ 1 mm diameter dry spot at the end of the growth tube in a 100 µL well of a multi-well plate. The well plate advances automatically to provide a sequence of time-resolved samples. The collected aerosols are subsequently analyzed in the laboratory. The sample is concentrated during the collection process, and the laboratory extraction and analysis steps can be automated. The well plate, as received from the field, is placed onto a needle-based autosampler that adds liquid for sample extraction and injects sample extract from each well onto an ion chromatograph for analysis. Laboratory evaluation for sulfate and nitrate ions showed that poly ether ether ketone (PEEK) used as well plate material does not contribute any artifacts; a 60 min extraction procedure leads to the recovery of sulfate and nitrate from the dry spots at above 95 % extraction efficiency; and samples stored frozen and analyzed up to 23 months later show less than a 10 % change in sulfate and nitrate concentrations. The limit of detection was 0.5 µg m-3 for sulfate and 0.2 µg m-3 for nitrate for a 1 h sampling period. In a month-long field study conducted in southern California, two S3s were deployed alongside a URG denuder-filter-pack and a Particle-Into-Liquid Sampler combined with an Ion Chromatograph (PILS-IC). Collocated S3 sampler concentrations compared by linear regression show good agreement, with r2 = 0.99 and slope = 0.99 (±0.004) µg m-3 for sulfate and r2 = 0.99 and slope = 1.0 (±0.006) µg m-3 for nitrate. When compared to the URG denuder-filter-pack and the PILS-IC, the S3 sulfate and nitrate concentrations yielded correlations above 0.84 for the square of the correlation coefficient and regression slopes close to 1.

Study of process variables in supercritical carbon dioxide extraction of soybeans.

PubMed

Wilkinson, Nikolas; Hilton, Ramsey; Hendry, Doug; Venkitasamy, Chandrasekar; Jacoby, William

2014-01-01

Soybean flakes were extracted using supercritical carbon dioxide at 48.3 MPa and 80 °C, which is a higher temperature than previously reported. Several operational parameters were explored to determine their effect on extractions. Flakes, as typically used in this industry, provided the best extraction performance. Particle size distributions were created through grinding. Reducing average particle diameters smaller than 0.069 mm had no appreciable effect on increasing extraction efficiencies. Exploration of flow rate indicated that a residence time of less than 60 s for the supercritical carbon dioxide would be sufficient for complete extractions. A solvent mass to load mass ratio of 10:1 was found to be sufficient for extraction of oils from soybean flakes. Increasing moisture in the soybeans led to decreasing extraction efficiency of oils. Finally, soybean hulls had no effect on extraction efficiency. Thus, the de-hulling procedure can be removed from the extraction process without decreasing extraction efficiency.

Cloning and characterization of an 11S legumin, Car i 4, a major allergen in pecan.

PubMed

Sharma, Girdhari M; Irsigler, Andre; Dhanarajan, Pushparani; Ayuso, Rosalia; Bardina, Luda; Sampson, Hugh A; Roux, Kenneth H; Sathe, Shridhar K

2011-09-14

Among tree nut allergens, pecan allergens remain to be identified and characterized. The objective was to demonstrate the IgE-binding ability of pecan 11S legumin and characterize its sequential IgE-binding epitopes. The 11S legumin gene was amplified from a pecan cDNA library and expressed as a fusion protein in Escherichia coli. The native 11S legumin in pecan extract was identified by mass spectrometry/mass spectrometry (MS/MS). Sequential epitopes were determined by probing the overlapping peptides with three serum pools prepared from different patients' sera. A three-dimensional model was generated using almond legumin as a template and compared with known sequential epitopes on other allergenic tree nut homologues. Of 28 patients tested by dot blot, 16 (57%) bound to 11S legumin, designated Car i 4. MS/MS sequencing of native 11S legumin identified 33 kDa acidic and 20-22 kDa basic subunits. Both pecan and walnut seed protein extracts inhibited IgE binding to recombinant Car i 4, suggesting cross-reactivity with Jug r 4. Sequential epitope mapping results of Car i 4 revealed weak, moderate, and strong reactivity of serum pools against 10, 5, and 4 peptides, respectively. Seven peptides were recognized by all three serum pools, of which two were strongly reactive. The strongly reactive peptides were located in three discrete regions of the Car i 4 acidic subunit sequence (residues 118-132, 208-219, and 238-249). Homology modeling of Car i 4 revealed significant overlapping regions shared in common with other tree nut legumins.

OPTIMIZING NIST SEQUENTIAL EXTRACTION METHOD FOR LAKE SEDIMENT (SRM4354)

EPA Science Inventory

Traditionally, measurements of radionuclides in the environment have focused on the determination of total concentration. It is clear, however, that total concentration does not describe the bioavailability of contaminating radionuclides. The environmental behavior depends on spe...

Assessing Metal Mobilization from Industrially Lead-Contaminated Soils Located at an Urban Site

EPA Science Inventory

A series of leaching and partitioning tests (Toxicity Characteristic Leaching Procedure (TCLP), Synthetic Precipitation Leaching Procedure (SPLP), Controlled Acidity Leaching Protocol (CALP), Acid Neutralization Capacity (ANC), and sequential extraction) were applied to three dif...

A sequential extraction and hydrolysis approach to understand the chemical nature of soil water repellency

NASA Astrophysics Data System (ADS)

Mao, Jiefei; Dekker, Stefan C.; Nierop, Klaas G. J.

2014-05-01

Soil water repellency (SWR) biomarkers (SWR-biomarkers) are defined as hydrophobic organic compounds in soils causing SWR and originating from vegetation or microbes (Doerr et al., 2000). Free lipids and ester-bound biopolymers (cutins and suberins) are usually seen in the aliphatic part of soil organic matter (SOM) (Nierop, 1998). The method of sequential extraction can divide hydrophobic compounds into individual fractions with different characteristics. We aim to find out the SWR-biomarkers in soils within different fractions, investigate the effects of fractions on SWR and link them to their original sources. To extract free and ester-bound lipids from sandy soils, DCM (dichloromethane)/MeOH (methanol) and IPA(isopropanol)/NH3 were used in sequential steps. As a result, three fractions were obtained during these sequential experiments: a DCM/MeOH soluble fraction (D), a DCM-MeOH soluble (AS) fraction of IPA/NH3 extracts and its insoluble (AI) fraction. To date, research was limited to (organic) extractable fractions only. To investigate the DCM-MeOH insoluble part of IPA/NH3 extracts they were depolymerised by trans-methylation using BF3-MeOH. All fractions were analysed by gas chromatography-mass spectrometry. After DCM/MeOH extraction, water repellency of 80% of the soils studied increased while SWR of the other soils remained at the same level. Straight-chain fatty acids, alcohols and alkanes were the main compound groups in the D fractions. The distribution of fatty acids (C20-C32) and alcohols (C20-C32), both of which with an even-over-odd predominance suggest their source were higher plants, and so did the odd-over-even predominated alkanes. After extraction by IPA/NH3 , most soils became non-repellent. Both fatty acids (C16-C32) and alcohols (C16-C30) with an even-over-odd predominance were also found in the AS fractions, whereas no alkanes were detected. There were four main component groups identified in the AI fractions: fatty acids, alcohols, ω-hydroxy fatty acids and α,ω-dicarboxylic acids. Aside from fatty acids and alcohols, the latter two compound groups were considered as the main groups of monomers released from suberins. Therefore, suberin-derived compounds were most abundant in the AI fractions suggesting that plant roots could be the main source of AI fractions. We will present some of the relations between fractions/compounds and SWR to show that this approach may be an effective tool to improve our understanding of SWR mechanisms. We present relations between fractions/compounds from SOM with SWR to determine SWR-biomarkers. By assessing the origin of these biomarkers, we are able to understand how SWR is formed and in which circumstances they are mainly from leaves or roots (i.e. cutin or suberin). References: Doerr, S.H., Shakesby, R.A., Walsh, R.P.D., 2000. Soil water repellency: its causes, characteristics and hydro- geomorphological significance. Earth-Sci. Rev. 51, 33-65. Nierop, K.G.J., 1998. Origin of aliphatic compounds in a forest soil. Organic Geochemistry 29, 1009-1016.

Effects of Training Auditory Sequential Memory and Attention on Reading.

ERIC Educational Resources Information Center

Klein, Pnina S.; Schwartz, Allen A.

To determine if auditory sequential memory (ASM) in young children can be improved through training and to discover the effects of such training on the reading scores of children with reading problems, a study was conducted involving 92 second and third graders. For purposes of this study, auditory sequential memory was defined as the ability to…

Optimization of multiple turbine arrays in a channel with tidally reversing flow by numerical modelling with adaptive mesh.

PubMed

Divett, T; Vennell, R; Stevens, C

2013-02-28

At tidal energy sites, large arrays of hundreds of turbines will be required to generate economically significant amounts of energy. Owing to wake effects within the array, the placement of turbines within will be vital to capturing the maximum energy from the resource. This study presents preliminary results using Gerris, an adaptive mesh flow solver, to investigate the flow through four different arrays of 15 turbines each. The goal is to optimize the position of turbines within an array in an idealized channel. The turbines are represented as areas of increased bottom friction in an adaptive mesh model so that the flow and power capture in tidally reversing flow through large arrays can be studied. The effect of oscillating tides is studied, with interesting dynamics generated as the tidal current reverses direction, forcing turbulent flow through the array. The energy removed from the flow by each of the four arrays is compared over a tidal cycle. A staggered array is found to extract 54 per cent more energy than a non-staggered array. Furthermore, an array positioned to one side of the channel is found to remove a similar amount of energy compared with an array in the centre of the channel.

Selective Extraction of Rare Earth Elements from Permanent Magnet Scraps with Membrane Solvent Extraction

DOE PAGES

Kim, Daejin; Powell, Lawrence E.; Delmau, Lætitia H.; ...

2015-06-24

In this paper, the rare earth elements (REEs) such as neodymium, praseodymium, and dysprosium were successfully recovered from commercial NdFeB magnets and industrial scrap magnets via membrane assisted solvent extraction (MSX). A hollow fiber membrane system was evaluated to extract REEs in a single step with the feed and strip solutions circulating continuously through the MSX system. The effects of several experimental variables on REE extraction such as flow rate, concentration of REEs in the feed solution, membrane configuration, and composition of acids were investigated with the MSX system. A multimembrane module configuration with REEs dissolved in aqueous nitric acidmore » solutions showed high selectivity for REE extraction with no coextraction of non-REEs, whereas the use of aqueous hydrochloric acid solution resulted in coextraction of non-REEs due to the formation of chloroanions of non-REEs. The REE oxides were recovered from the strip solution through precipitation, drying, and annealing steps. Finally, the resulting REE oxides were characterized with XRD, SEM-EDX, and ICP-OES, demonstrating that the membrane assisted solvent extraction is capable of selectively recovering pure REEs from the industrial scrap magnets.« less

Influence of flow variability on floodplain formation and destruction, Little Missouri River, North Dakota

USGS Publications Warehouse

Miller, J.R.; Friedman, J.M.

2009-01-01

Resolving observations of channel change into separate planimetric measurements of floodplain formation and destruction reveals distinct relations between these processes and the flow regime. We analyzed a time sequence of eight bottomland images from 1939 to 2003 along the Little Missouri River, North Dakota, to relate geomorphic floodplain change to flow along this largely unregulated river. At the decadal scale, floodplain formation and destruction varied independently. Destruction was strongly positively correlated with the magnitude of infrequent high flows that recur every 5-10 yr, whereas floodplain formation was negatively correlated with the magnitude of frequent low flows exceeded 80% of the time. At the century scale, however, a climatically induced decrease in peak flows has reduced the destruction rate, limiting the area made available for floodplain formation. The rate of destruction was not uniform across the floodplain. Younger surfaces were consistently destroyed at a higher rate than older surfaces, suggesting that throughput of contaminants would have occurred more rapidly than predicted by models that assume uniform residence time of sediment across the floodplain. Maps of floodplain ages produced by analysis of sequential floodplain images are similar to maps of forest ages produced through dendrochronology, confirming the assumption of dendrogeomorphic studies that riparian tree establishment in this system is limited to recent channel locations. ?? 2009 Geological Society of America.

Antitumor Activity of Ethanolic Extract of Dendrobium formosum in T-Cell Lymphoma: An In Vitro and In Vivo Study

PubMed Central

Prasad, Ritika; Koch, Biplob

2014-01-01

Dendrobium, a genus of orchid, was found to possess useful therapeutic activities like anticancer, hypoglycaemic, antimicrobial, immunomodulatory, hepatoprotective, antioxidant, and neuroprotective activities. The study was aimed to evaluate the anticancer property of the ethanolic extract of Dendrobium formosum on Dalton's lymphoma. In vitro cytotoxicity was determined by MTT assay, apoptosis was determined by fluorescence microscopy, and cell cycle progression was analysed using flow cytometry; in vivo antitumor activity was performed in Dalton's lymphoma bearing mice. The IC50 value of ethanolic extract was obtained at 350 μg/mL in Dalton's lymphoma cells. Fluorescence microscopy analysis showed significant increase in apoptotic cell death in dose- and time-dependent manner which was further confirmed through the resulting DNA fragmentation. Further, flow cytometry analysis showed that the ethanolic extract arrests the cells in G2/M phase of the cell cycle. The in vivo anticancer activity study illustrates significant increase in the survival time of Dalton's lymphoma bearing mice on treatment with ethanolic extract when compared to control. These results substantiate the antitumor properties of ethanolic extract of Dendrobium formosum and suggest an alternative in treatment of cancer. Further studies are required regarding the isolation and characterization of bioactive components along with the analysis of molecular mechanism involved. PMID:24959588

[Inhibition effects of black rice pericarp extracts on cell proliferation of PC-3 cells].

PubMed

Jiang, Weiwei; Yu, Xudong; Ren, Guofeng

2013-05-01

To observe the inhibitive effects of black rice pericarp extracts on cell proliferation of human prostate cancer cell PC-3 and to explore its effecting mechanism. The black rice pericarp extract was used to treat the PC-3 cells. The inhibitory effect of black rice pericarp extract on cells proliferation of PC-3 was tested by MTT method. Cell apoptosis rates and cell cycle were measured by flow cytometric assay (FCM). Western blot was used to study the protein expression levels of p38, p-p38, JNK, p-JNK. A dose-dependent and time-dependent proliferation inhibition of black rice pericarp extract was demonstrated in PC-3. The most prominent experiment condition was inhibitory concentration with 300microg/ml and treated for 72 h. The experiment result of flow cytometry analysis demonstrates that the apoptosis rate of PC-3 cells increased along with the increasing of black rice pericarp extract concentration, and a G1-S cell cycle arrest was induced in a dose-dependent manner. After PC-3 cell was treated with black rice pericarp extract for 72 h, the expressions of p-p38, p-JNK protein increased. Black rice pericarp extract could inhibit proliferation, change the cell cycle distributions and induce apoptosis in human prostatic cancer cell PC-3. Its inhibitory effect may be through promoting activation of the JNK, p38 signaling pathway. These results suggest that black rice pericarp extract maybe has an inhibitory effect on prostatic cancer.

Associations of cadmium, zinc, and lead in soils from a lead and zinc mining area as studied by single and sequential extractions.

PubMed

Anju, M; Banerjee, D K

2011-05-01

An exploratory study of the area surrounding a historical Pb-Zn mining and smelting area in Zawar, India, detected significant contamination of the terrestrial environment by heavy metals. Soils (n=87) were analyzed for pH, EC, total organic matter (TOM), Pb, Zn, Mn, and Cd levels. The statistical analysis indicated that the frequency distribution of the analyzed parameters for these soils was not normal. The median concentrations of metals in surface soils were: Pb 420.21 μ g/g, Zn 870.25 μ g/g, Mn 696.70 μ g/g, and Cd 2.09 μ g/g. Zn concentrations were significantly correlated with Cd (r=0.867), indicating that levels of Cd are dependent on Zn. However, pH, electrical conductivity and total organic matter were not correlated significantly with Cd, Pb, Zn, and Mn. To assess the potential mobility of Cd, Pb, and Zn in soils, single (EDTA) as well as sequential extraction scheme (modified BCR) were applied to representative (n=23) soil samples. The amount of Cd, Pb, and Zn extracted by EDTA and their total concentrations showed linear positive correlation, which are statistically significant (r values for Cd, Pb, and Zn being 0.901, 0.971, and 0.795, respectively, and P values being <0.001). The correlation coefficients indicate a strong relation between EDTA-extractable metal and total metal. These results appear to justify the use of 'total' metal contents as a useful preliminary indicator of areas where the risks of metal excess or deficiency are high. The EDTA extractability was maximum for Cd followed by Pb and Zn in soils from all the locations. As indicated by single extraction, the apparent mobility and potential bioavailability of metals in soils followed the order: Cd ≥ Pb > > Zn. Soil samples were sequentially extracted (modified BCR) so that solid pools of Cd, Zn, and Pb could be partitioned into four operationally defined fractions viz. acid-soluble, reducible, oxidizable, and residual. Cadmium was present appreciably (39.41%) in the acid-soluble fraction and zinc was predominantly associated (32.42%) with residual fraction. Pb (66.86%) and Zn (30.44%) were present mainly in the reducible fraction. Assuming that the mobility and bioavailability are related to solubility of geochemical forms of metals and decrease in the order of extraction, the apparent mobility and potential metal bioavailability for these contaminated soil samples is Cd > Zn > Pb.

Finite elements for the calculation of turbulent flows in three-dimensional complex geometries

NASA Astrophysics Data System (ADS)

Ruprecht, A.

A finite element program for the calculation of incompressible turbulent flows is presented. In order to reduce the required storage an iterative algorithm is used which solves the necessary equations sequentially. The state of turbulence is defined by the k-epsilon model. In addition to the standard k-epsilon model, the modification of Bardina et al., taking into account the rotation of the mean flow, is investigated. With this program, the flow in the draft tube of a Kaplan turbine is examined. Calculations are carried out for swirling and nonswirling entrance flow. The results are compared with measurements.

Improved numerical methods for turbulent viscous flows aerothermal modeling program, phase 2

NASA Technical Reports Server (NTRS)

Karki, K. C.; Patankar, S. V.; Runchal, A. K.; Mongia, H. C.

1988-01-01

The details of a study to develop accurate and efficient numerical schemes to predict complex flows are described. In this program, several discretization schemes were evaluated using simple test cases. This assessment led to the selection of three schemes for an in-depth evaluation based on two-dimensional flows. The scheme with the superior overall performance was incorporated in a computer program for three-dimensional flows. To improve the computational efficiency, the selected discretization scheme was combined with a direct solution approach in which the fluid flow equations are solved simultaneously rather than sequentially.

Internally-cooled centrifugal compressor with cooling jacket formed in the diaphragm

DOEpatents

Moore, James J.; Lerche, Andrew H.; Moreland, Brian S.

2014-08-26

An internally-cooled centrifugal compressor having a shaped casing and a diaphragm disposed within the shaped casing having a gas side and a coolant side so that heat from a gas flowing though the gas side is extracted via the coolant side. An impeller disposed within the diaphragm has a stage inlet on one side and a stage outlet for delivering a pressurized gas to a downstream connection. The coolant side of the diaphragm includes at least one passageway for directing a coolant in a substantially counter-flow direction from the flow of gas through the gas side.

Speciations of trace metals in the Danube alluvial sediments within an oil refinery.

PubMed

Relić, Dubravka; Dordević, Dragana; Popović, Aleksandar; Blagojević, Tamara

2005-07-01

A sequential extraction procedure was applied to identify forms of Ni, Zn, Pb and Cu with Fe- and Mn-oxides associated in alluvial sediments of the River Danube within Pancevo Oil Refinery (Serbia). The five steps of the sequential extraction procedure partitioned metals into: CH(3)COONH(4) extractable (S1); NH(2)OH.HCl carbonate extractable and easily reducible (S2); (NH(4))(2)C(2)O(2)/H(2)C(2)O(2) moderately reducible (S3); H(2)O(2)-HNO(3) organic extractable (S4); and HCl acid soluble residue (S5). Extracted concentrations of trace metals, analyzed after all five steps, were found to be (mg kg(-1)) for Mn: 656, Fe: 26734, Ni: 32.3, Zn: 72.8, Pb: 13.4 and Cu: 27.0. Most of the elements were found in acid soluble residue, characterizing stable compounds in sediments. Non-residual fractions of trace metals (sum of the first four fractions) were analyzed because they are more bioavailable than the residual amount. Correlation analysis and two multivariate analysis methods (principal component and cluster analysis) were used to understand and visualize the associations between the non-residual fractions of trace metals and certain forms, more or less crystalline of Fe- and Mn-oxides within the analyzed sediments, since Fe- and Mn-oxides play an important role in trace metal sorption within aquatic systems, especially within the Danube alluvium where the fluctuations of groundwater are very frequent and the level of groundwater could come close to surface.

Sequential Extraction Results in Improved Proteome Profiling of Medicinal Plant Pinellia ternata Tubers, Which Contain Large Amounts of High-Abundance Proteins

PubMed Central

An, SuFang; Gong, FangPing; Wang, Wei

2012-01-01

Pinellia ternata tuber is one of the well-known Chinese traditional medicines. In order to understand the pharmacological properties of tuber proteins, it is necessary to perform proteome analysis of P. ternata tubers. However, a few high-abundance proteins (HAPs), mainly mannose-binding lectin (agglutinin), exist in aggregates of various sizes in the tubers and seriously interfere with proteome profiling by two-dimensional electrophoresis (2-DE). Therefore, selective depletion of these HAPs is a prerequisite for enhanced proteome analysis of P. ternata tubers. Based on differential protein solubility, we developed a novel protocol involving two sequential extractions for depletion of some HAPs and prefractionation of tuber proteins prior to 2-DE. The first extraction using 10% acetic acid selectively extracted acid-soluble HAPs and the second extraction using the SDS-containing buffer extracted remaining acid-insoluble proteins. After application of the protocol, 2-DE profiles of P. ternata tuber proteins were greatly improved and more protein spots were detected, especially low-abundance proteins. Moreover, the subunit composition of P. ternata lectin was analyzed by electrophoresis. Native lectin consists of two hydrogen-bonded subunits (11 kDa and 25 kDa) and the 11 kDa subunit was a glycoprotein. Subsequently, major HAPs in the tubers were analyzed by mass spectrometry, with nine protein spots being identified as lectin isoforms. The methodology was easy to perform and required no specialized apparatus. It would be useful for proteome analysis of other tuber plants of Araceae. PMID:23185632

Sequential extraction results in improved proteome profiling of medicinal plant Pinellia ternata tubers, which contain large amounts of high-abundance proteins.

PubMed

Wu, Xiaolin; Xiong, Erhui; An, Sufang; Gong, Fangping; Wang, Wei

2012-01-01

Pinellia ternata tuber is one of the well-known Chinese traditional medicines. In order to understand the pharmacological properties of tuber proteins, it is necessary to perform proteome analysis of P. ternata tubers. However, a few high-abundance proteins (HAPs), mainly mannose-binding lectin (agglutinin), exist in aggregates of various sizes in the tubers and seriously interfere with proteome profiling by two-dimensional electrophoresis (2-DE). Therefore, selective depletion of these HAPs is a prerequisite for enhanced proteome analysis of P. ternata tubers. Based on differential protein solubility, we developed a novel protocol involving two sequential extractions for depletion of some HAPs and prefractionation of tuber proteins prior to 2-DE. The first extraction using 10% acetic acid selectively extracted acid-soluble HAPs and the second extraction using the SDS-containing buffer extracted remaining acid-insoluble proteins. After application of the protocol, 2-DE profiles of P. ternata tuber proteins were greatly improved and more protein spots were detected, especially low-abundance proteins. Moreover, the subunit composition of P. ternata lectin was analyzed by electrophoresis. Native lectin consists of two hydrogen-bonded subunits (11 kDa and 25 kDa) and the 11 kDa subunit was a glycoprotein. Subsequently, major HAPs in the tubers were analyzed by mass spectrometry, with nine protein spots being identified as lectin isoforms. The methodology was easy to perform and required no specialized apparatus. It would be useful for proteome analysis of other tuber plants of Araceae.

The removal of heavy metals from contaminated soil by a combination of sulfidisation and flotation.

PubMed

Vanthuyne, Mathias; Maes, André

2002-05-06

The possibility of removing cadmium, copper, lead and zinc from Belgian loamy soil by a combination of sulfidisation pre-treatment and Denver flotation was investigated. The potentially available--sulfide convertible--metal content of the metal polluted soil was estimated by EDTA (0.1 M, pH 4.65) extraction and BCR sequential extraction. EDTA extraction is better at approximating the metal percentage that is expected to be convertible into a metal sulfide phase, in contrast to the sequential extraction procedure of 'Int. J. Environ. Anal. Chem. 51 (1993) pp. 135-151' in which transition metals present as iron oxide co-precipitates are dissolved by hydroxylammoniumchloride in the second extraction step. To compare the surface characteristics of metal sulfides formed by sulfidisation with those of crystalline metal sulfides, two types of synthetic sediments were prepared and extracted with 0.1 M EDTA (pH 4.65) in anoxic conditions. Separate metal sulfides or co-precipitates with iron sulfide were formed by sulfide conditioning. The Denver flotation of both types of synthetic sediments (kerosene as collector at high background electrolyte concentrations) resulted in similar concentrating factors for freshly formed metal sulfides as for fine-grained crystalline metal sulfides. The selective flotation of metal sulfides after sulfide conditioning of a polluted soil, using kerosene or potassium ethyl xanthate as collectors and MIBC as frother, was studied at high background electrolyte concentrations. The sulfidisations were made in ambient air and inside an anoxic glove box. The concentrating factors corrected by the potentially available metal percentage, determined by 0.1 M EDTA extraction, lie between 2 and 3. The selective flotation of these finely dispersed, amorphous, metal sulfides can possibly be improved by optimising the bubble-particle interaction.

Enhancement of wall jet transport properties

DOEpatents

Claunch, Scott D.; Farrington, Robert B.

1997-01-01

By enhancing the natural instabilities in the boundary layer and in the free shear layer of a wall jet, the boundary is minimized thereby increasing the transport of heat and mass. Enhancing the natural instabilities is accomplished by pulsing the flow of air that creates the wall jet. Such pulsing of the flow of air can be accomplished by sequentially occluding and opening a duct that confines and directs the flow of air, such as by rotating a disk on an axis transverse to the flow of air in the duct.

Enhancement of wall jet transport properties

DOEpatents

Claunch, S.D.; Farrington, R.B.

1997-02-04

By enhancing the natural instabilities in the boundary layer and in the free shear layer of a wall jet, the boundary is minimized thereby increasing the transport of heat and mass. Enhancing the natural instabilities is accomplished by pulsing the flow of air that creates the wall jet. Such pulsing of the flow of air can be accomplished by sequentially occluding and opening a duct that confines and directs the flow of air, such as by rotating a disk on an axis transverse to the flow of air in the duct. 17 figs.

Fate of 90Sr and U(VI) in Dounreay sediments following saline inundation and erosion.

PubMed

Eagling, Jane; Worsfold, Paul J; Blake, William H; Keith-Roach, Miranda J

2013-08-01

There is concern that sea level rise associated with projected climate change will lead to the inundation, flooding and erosion of soils and sediments contaminated with radionuclides at coastal nuclear sites, such as Dounreay (UK), with seawater. Here batch and column experiments were designed to simulate these scenarios and sequential extractions were used to identify the key radionuclide solid phase associations. Strontium was exchangeable and was mobilised rapidly by ion exchange with seawater Mg(2+) in both batch and column experiments. In contrast, U was more strongly bound to the sediments and mobilisation was initially limited by the influence of the sediment on the pH of the water. Release was only observed when the pH increased above 6.9, suggesting that the formation of soluble U(VI)-carbonate species was important. Under dynamic flow conditions, long term release was significant (47%), but controlled by slow desorption kinetics from a range of binding sites. Copyright © 2013 Elsevier Ltd. All rights reserved.

Nonthermal plasma processor utilizing additive-gas injection and/or gas extraction

DOEpatents

Rosocha, Louis A.

2006-06-20

A device for processing gases includes a cylindrical housing in which an electrically grounded, metal injection/extraction gas supply tube is disposed. A dielectric tube surrounds the injection/extraction gas supply tube to establish a gas modification passage therearound. Additionally, a metal high voltage electrode circumscribes the dielectric tube. The high voltage electrode is energizable to create nonthermal electrical microdischarges between the high voltage electrode and the injection/extraction gas supply tube across the dielectric tube within the gas modification passage. An injection/extraction gas and a process gas flow through the nonthermal electrical microdischarges within the gas modification passage and a modified process gas results. Using the device contaminants that are entrained in the process gas can be destroyed to yield a cleaner, modified process gas.

Sequential state discrimination and requirement of quantum dissonance

NASA Astrophysics Data System (ADS)

Pang, Chao-Qian; Zhang, Fu-Lin; Xu, Li-Fang; Liang, Mai-Lin; Chen, Jing-Ling

2013-11-01

We study the procedure for sequential unambiguous state discrimination. A qubit is prepared in one of two possible states and measured by two observers Bob and Charlie sequentially. A necessary condition for the state to be unambiguously discriminated by Charlie is the absence of entanglement between the principal qubit, prepared by Alice, and Bob's auxiliary system. In general, the procedure for both Bob and Charlie to recognize between two nonorthogonal states conclusively relies on the availability of quantum discord which is precisely the quantum dissonance when the entanglement is absent. In Bob's measurement, the left discord is positively correlated with the information extracted by Bob, and the right discord enhances the information left to Charlie. When their product achieves its maximum the probability for both Bob and Charlie to identify the state achieves its optimal value.

Exploring Learners' Sequential Behavioral Patterns, Flow Experience, and Learning Performance in an Anti-Phishing Educational Game

ERIC Educational Resources Information Center

Sun, Jerry Chih-Yuan; Kuo, Cian-Yu; Hou, Huei-Tse; Lin, Yu-Yan

2017-01-01

The purposes of this study were to provide a game-based anti-phishing lesson to 110 elementary school students in Taiwan, explore their learning behavioral patterns, and investigate the effects of the flow states on their learning behavioral patterns and learning achievement. The study recorded behaviour logs, and applied a pre- and post-test on…

Airway reopening through catastrophic events in a hierarchical network

PubMed Central

Baudoin, Michael; Song, Yu; Manneville, Paul; Baroud, Charles N.

2013-01-01

When you reach with your straw for the final drops of a milkshake, the liquid forms a train of plugs that flow slowly initially because of the high viscosity. They then suddenly rupture and are replaced with a rapid airflow with the characteristic slurping sound. Trains of liquid plugs also are observed in complex geometries, such as porous media during petroleum extraction, in microfluidic two-phase flows, or in flows in the pulmonary airway tree under pathological conditions. The dynamics of rupture events in these geometries play the dominant role in the spatial distribution of the flow and in determining how much of the medium remains occluded. Here we show that the flow of a train of plugs in a straight channel is always unstable to breaking through a cascade of ruptures. Collective effects considerably modify the rupture dynamics of plug trains: Interactions among nearest neighbors take place through the wetting films and slow down the cascade, whereas global interactions, through the total resistance to flow of the train, accelerate the dynamics after each plug rupture. In a branching tree of microchannels, similar cascades occur along paths that connect the input to a particular output. This divides the initial tree into several independent subnetworks, which then evolve independently of one another. The spatiotemporal distribution of the cascades is random, owing to strong sensitivity to the plug divisions at the bifurcations. PMID:23277557

Trace and major element pollution originating from coal ash suspension and transport processes.

PubMed

Popovic, A; Djordjevic, D; Polic, P

2001-04-01

Coal ash obtained by coal combustion in the "Nikola Tesla A" power plant in Obrenovac, near Belgrade, Yugoslavia, is mixed with water of the Sava river and transported to the dump. In order to assess pollution caused by leaching of some minor and major elements during ash transport through the pipeline, two sets of samples (six samples each) were subjected to a modified sequential extraction. The first set consisted of coal ash samples taken immediately after combustion, while the second set was obtained by extraction with river water, imitating the processes that occur in the pipeline. Samples were extracted consecutively with distilled water and a 1 M solution of KCl, pH 7, and the differences in extractability were compared in order to predict potential pollution. Considering concentrations of seven trace elements as well as five major elements in extracts from a total of 12 samples, it can be concluded that lead and cadmium do not present an environmental threat during and immediately after ash transport to the dump. Portions of zinc, nickel and chromium are released during the ash transport, and arsenic and manganese are released continuously. Copper and iron do not present an environmental threat due to element leaching during and immediately after the coal ash suspension and transport. On the contrary, these elements, as well as chromium, become concentrated during coal ash transport. Adsorbed portions of calcium, magnesium and potassium are also leached during coal ash transport.

Efficient flow injection and sequential injection methods for spectrophotometric determination of oxybenzone in sunscreens based on reaction with Ni(II).

PubMed

Chisvert, A; Salvador, A; Pascual-Martí, M C; March, J G

2001-04-01

Spectrophotometric determination of a widely used UV-filter, such as oxybenzone, is proposed. The method is based on the complexation reaction between oxybenzone and Ni(II) in ammoniacal medium. The stoichiometry of the reaction, established by the Job method, was 1:1. Reaction conditions were studied and the experimental parameters were optimized, for both flow injection (FI) and sequential injection (SI) determinations, with comparative purposes. Sunscreen formulations containing oxybenzone were analyzed by the proposed methods and results compared with those obtained by HPLC. Data show that both FI and SI procedures provide accurate and precise results. The ruggedness, sensitivity and LOD are adequate to the analysis requirements. The sample frequency obtained by FI is three-fold higher than that of SI analysis. SI is less reagent-consuming than FI.

Modelling, fabrication and characterization of a polymeric micromixer based on sequential segmentation.

PubMed

Nguyen, Nam-Trung; Huang, Xiaoyang

2006-06-01

Effective and fast mixing is important for many microfluidic applications. In many cases, mixing is limited by molecular diffusion due to constrains of the laminar flow in the microscale regime. According to scaling law, decreasing the mixing path can shorten the mixing time and enhance mixing quality. One of the techniques for reducing mixing path is sequential segmentation. This technique divides solvent and solute into segments in axial direction. The so-called Taylor-Aris dispersion can improve axial transport by three orders of magnitudes. The mixing path can be controlled by the switching frequency and the mean velocity of the flow. Mixing ratio can be controlled by pulse width modulation of the switching signal. This paper first presents a simple time-dependent one-dimensional analytical model for sequential segmentation. The model considers an arbitrary mixing ratio between solute and solvent as well as the axial Taylor-Aris dispersion. Next, a micromixer was designed and fabricated based on polymeric micromachining. The micromixer was formed by laminating four polymer layers. The layers are micro machined by a CO(2) laser. Switching of the fluid flows was realized by two piezoelectric valves. Mixing experiments were evaluated optically. The concentration profile along the mixing channel agrees qualitatively well with the analytical model. Furthermore, mixing results at different switching frequencies were investigated. Due to the dynamic behavior of the valves and the fluidic system, mixing quality decreases with increasing switching frequency.

The drag forces exerted by lahar flows on a cylindrical pier: case study of post Mount Merapi eruptions

NASA Astrophysics Data System (ADS)

Faizien Haza, Zainul

2018-03-01

Debris flows of lahar flows occurred in post mount eruption is a phenomenon in which large quantities of water, mud, and gravel flow down a stream at a high velocity. It is a second stage of danger after the first danger of lava flows, pyroclastic, and toxic gases. The debris flow of lahar flows has a high density and also high velocity; therefore it has potential detrimental consequences against homes, bridges, and infrastructures, as well as loss of life along its pathway. The collision event between lahar flows and pier of a bridge is observed. The condition is numerically simulated using commercial software of computational fluid dynamic (CFD). The work is also conducted in order to investigate drag force generated during collision. Rheological data of lahar is observed through laboratory test of lahar model as density and viscosity. These data were used as the input data of the CFD simulation. The numerical model is involving two types of fluid: mud and water, therefore multiphase model is adopted in the current CFD simulation. The problem formulation is referring to the constitutive equations of mass and momentum conservation for incompressible and viscous fluid, which in perspective of two dimension (2D). The simulation models describe the situation of the collision event between lahar flows and pier of a bridge. It provides sequential view images of lahar flow impaction and the propagation trend line of the drag force coefficient values. Lahar flow analysis used non-dimensional parameter of Reynolds number. According to the results of numerical simulations, the drag force coefficients are in range 1.23 to 1.48 those are generated by value of flow velocity in range 11.11 m/s to 16.67 m/s.

Liquid/Gas Separator Handles Varying Loads

NASA Technical Reports Server (NTRS)

Mann, John

1992-01-01

Liquid/gas separator includes two independent motors, one for pumping mixture and other for drawing off extracted gas. Two materials moved at speeds best suited for them. Liquid expelled radially outward from separator rotor. Entrained gas released, flows axially through rotor, and leaves through fan at downstream end. Unit developed to separate air from urine in spacecraft wastewater-treatment system, also functions in normal gravity. Made largely of titanium to resist corrosion.

Mercury Speciation by X-ray Absorption Fine Structure Spectroscopy and Sequential Chemical Extractions: A Comparison of Speciation Methods

USGS Publications Warehouse

Kim, C.S.; Bloom, N.S.; Rytuba, J.J.; Brown, Gordon E.

2003-01-01

Determining the chemical speciation of mercury in contaminated mining and industrial environments is essential for predicting its solubility, transport behavior, and potential bioavailability as well as for designing effective remediation strategies. In this study, two techniques for determining Hg speciation-X-ray absorption fine structure (XAFS) spectroscopy and sequential chemical extractions (SCE)-are independently applied to a set of samples with Hg concentrations ranging from 132 to 7539 mg/kg to determine if the two techniques provide comparable Hg speciation results. Generally, the proportions of insoluble HgS (cinnabar, metacinnabar) and HgSe identified by XAFS correlate well with the proportion of Hg removed in the aqua regia extraction demonstrated to remove HgS and HgSe. Statistically significant (> 10%) differences are observed however in samples containing more soluble Hg-containing phases (HgCl2, HgO, Hg3S2O 4). Such differences may be related to matrix, particle size, or crystallinity effects, which could affect the apparent solubility of Hg phases present. In more highly concentrated samples, microscopy techniques can help characterize the Hg-bearing species in complex multiphase natural samples.

[Antegrade diastolic blood flow and classic reflux in varicose dilatation of the intersaphenous vein].

PubMed

Shaidakov, E V; Rosukhovsky, D A; Grigoryan, A G; Bulatov, V L; Ilyukhin, E A

2016-01-01

In the intersaphenous vein (ISV) there may take place the so-called "antegrade" or "paradoxical" reflux. This type of blood flow is revealed in a series of patients during muscular diastole and is a link of the pathogenesis of varicose disease, but has, as distinct from the "classical" reflux, an antegrade direction. An incompetent saphenopopliteal junction (SPJ) is a source of the antegrade diastolic blood flow (ADBF) through the ISV. Descriptions of possible variants of impaired blood flow through the ISV are fragmentary and their interpretations are controversial. Prevalence and pathogenesis of these disorders impairments have not yet been studied. A cross-sectional study: over 4 years three centres examined a total of 1,413 patients diagnosed with class C2-C6 varicose veins according the CEAP classification. All patients underwent ultrasound duplex scanning of lower limb veins. The ADBF was determined as a unidirectional antegrade blood flow with the duration of not more than 0.5 second, observed after the crus was relived of compression (in the diastole). Of the patients included into the study who had no varicose veins on the contralateral extremity with the ISV being spotted we sequentially selected 40 subjects including them into the Study Group for the analysis of blood flow and the diameter of the ISV in health. Impairments of blood flow in the ISV were revealed in 61 (4.8%) of 1,265 extremities included into the study: the "classical" reflux in 9 (14.8%) limbs, ADBF was revealed in 37 (60.7%) limbs, a combination of the "classical" blood flow and ADBF - in 15 (24.6%) limbs. Hence, the patients were subdivided into three groups. Studying the nature of blood flow through the ISV in the control group on 40 lower limbs revealed no blood flow disorders. The mean ISV diameter amounted to 1.68 mm (ME=1 mm). The ISV diameter was considerably higher in all studied groups as compared with the control one (p<0.0001). The diameter of the ISV in its proximal portion averagely amounted to 4.48 mm (SD 1.337 mm, SE 0.171 mm). The diameter in the distal portion amounted to 5.39 mm (SD 1.725 mm, SE 0.221 mm).

Stagnation, circulation, and erosion of granular materials through belt conveyor sluice gate

NASA Astrophysics Data System (ADS)

Pohlman, Nicholas; Moralda, Michael; Dunne, Ryan

2013-11-01

Control of flow rates in conversion reactors for discrete materials like biomass can be achieved in belt conveyors through a combination of belt speed, hopper size, and aperture opening. As material is extracted from the bottom of the storage hopper, other material cannot achieve plug flow and therefore is restricted from exiting through a sluice-gate type opening. The excess material moves vertically from the opening causing a pile up and recirculation back along the free surface of the hopper. Experimental results obtained through high speed imaging show the position of the stagnation point as well as the rate of circulation is dependent on the mass flow rate achieved and instantaneous fill level. The movement of material into the plug flow along the belt allows verification of deposition models on erodible beds rather than rigid surfaces with artificial roughness of glued particles. Similarly, the pile-up at the exit influences the efficiency of the transport affecting the narrow energy return on investment of biomass resources. The laboratory-scale behavior can therefore be translated into industrial performance metrics for increased operational efficiency. This work is supported by the NSF REU Site Operation E-Tank under award number 1156789.

Relation of retinal blood flow and retinal oxygen extraction during stimulation with diffuse luminance flicker

PubMed Central

Palkovits, Stefan; Lasta, Michael; Told, Reinhard; Schmidl, Doreen; Werkmeister, René; Cherecheanu, Alina Popa; Garhöfer, Gerhard; Schmetterer, Leopold

2015-01-01

Cerebral and retinal blood flow are dependent on local neuronal activity. Several studies quantified the increase in cerebral blood flow and oxygen consumption during activity. In the present study we investigated the relation between changes in retinal blood flow and oxygen extraction during stimulation with diffuse luminance flicker and the influence of breathing gas mixtures with different fractions of O2 (FiO2; 100% 15% and 12%). Twenty-four healthy subjects were included. Retinal blood flow was studied by combining measurement of vessel diameters using the Dynamic Vessel Analyser with measurements of blood velocity using laser Doppler velocimetry. Oxygen saturation was measured using spectroscopic reflectometry and oxygen extraction was calculated. Flicker stimulation increased retinal blood flow (57.7 ± 17.8%) and oxygen extraction (34.6 ± 24.1%; p < 0.001 each). During 100% oxygen breathing the response of retinal blood flow and oxygen extraction was increased (p < 0.01 each). By contrast, breathing gas mixtures with 12% and 15% FiO2 did not alter flicker–induced retinal haemodynamic changes. The present study indicates that at a comparable increase in blood flow the increase in oxygen extraction in the retina is larger than in the brain. During systemic hyperoxia the blood flow and oxygen extraction responses to neural stimulation are augmented. The underlying mechanism is unknown. PMID:26672758

Brazilian Red Propolis Induces Apoptosis-Like Cell Death and Decreases Migration Potential in Bladder Cancer Cells

PubMed Central

Begnini, Karine Rech; Moura de Leon, Priscila Marques; Thurow, Helena; Schultze, Eduarda; Campos, Vinicius Farias; Borsuk, Sibele; Dellagostin, Odir Antônio; Savegnago, Lucielli; Moura, Sidnei; Padilha, Francine F.; Pêgas Henriques, João Antonio; Seixas, Fabiana Kömmling

2014-01-01

Natural products continue to be an invaluable resource of anticancer drug discovery in recent years. Propolis is known for its biological activities such as antimicrobial and antitumor effects. This study assessed the effects of Brazilian red propolis (BRP) on apoptosis and migration potential in human bladder cancer cells. The effect of BRP ethanolic extract (25, 50, and 100 μg/mL) on 5637 cells was determined by MTT, LIVE/DEAD, and migration (scratch assay) assays. Apoptosis induction was investigated through flow cytometry and gene expression profile was investigated by qRT-PCR. Results showed cytotoxicity on MTT and LIVE/DEAD assays, with IC50 values of 95 μg/mL in 24 h of treatment. Cellular migration of 5637 cells was significantly inhibited through lower doses of BRP ethanolic extract (25 and 50 μg/mL). Flow cytometry analyses showed that BRP induced cytotoxicity through apoptosis-like mechanisms in 5637 cells and qRT-PCR revealed increased levels of Bax/Bcl-2 ratio, p53, AIF, and antioxidant enzymes genes. Data suggest that BRP may be a potential source of drugs to bladder cancer treatment. PMID:25530785

Brazilian red propolis induces apoptosis-like cell death and decreases migration potential in bladder cancer cells.

PubMed

Begnini, Karine Rech; Moura de Leon, Priscila Marques; Thurow, Helena; Schultze, Eduarda; Campos, Vinicius Farias; Martins Rodrigues, Fernanda; Borsuk, Sibele; Dellagostin, Odir Antônio; Savegnago, Lucielli; Roesch-Ely, Mariana; Moura, Sidnei; Padilha, Francine F; Collares, Tiago; Pêgas Henriques, João Antonio; Seixas, Fabiana Kömmling

2014-01-01

Natural products continue to be an invaluable resource of anticancer drug discovery in recent years. Propolis is known for its biological activities such as antimicrobial and antitumor effects. This study assessed the effects of Brazilian red propolis (BRP) on apoptosis and migration potential in human bladder cancer cells. The effect of BRP ethanolic extract (25, 50, and 100 μg/mL) on 5637 cells was determined by MTT, LIVE/DEAD, and migration (scratch assay) assays. Apoptosis induction was investigated through flow cytometry and gene expression profile was investigated by qRT-PCR. Results showed cytotoxicity on MTT and LIVE/DEAD assays, with IC50 values of 95 μg/mL in 24 h of treatment. Cellular migration of 5637 cells was significantly inhibited through lower doses of BRP ethanolic extract (25 and 50 μg/mL). Flow cytometry analyses showed that BRP induced cytotoxicity through apoptosis-like mechanisms in 5637 cells and qRT-PCR revealed increased levels of Bax/Bcl-2 ratio, p53, AIF, and antioxidant enzymes genes. Data suggest that BRP may be a potential source of drugs to bladder cancer treatment.

Application of EDTA decontamination on soils affected by mining activities and impact of treatment on the geochemical partition of metal contaminants.

PubMed

Xia, Wenbin; Gao, Hui; Wang, Xianhai; Zhou, Chunhua; Liu, Yunguo; Fan, Ting; Wang, Xin

2009-05-30

Two soil samples were collected at mining areas located in southern Hunan Province, China. EDTA extraction of Pb, Zn, Cu and Cd from these two tailing soils was studied using column leaching experiments. The redistributions of heavy metals (HMs) were determined using the modified BCR (Community Bureau of Reference) sequential extraction procedure, before and after EDTA extraction. The results indicated that EDTA was an effective extractant because of its strong chelating ability for various HMs. The proportions of Pb, Zn, Cu and Cd in the four fractions varied largely after EDTA extraction. The extraction efficiency of EDTA of the acid-extractable fraction (AEX) was significant in shallow soil column, while in deeper soil column, decrease of the extraction efficiency of reduced (RED), oxidizable (OX) and residual fractions (RES) was obtained, which was mainly due to the decrease of EDTA concentration.

Applying genetic algorithms for calibrating a hexagonal cellular automata model for the simulation of debris flows characterised by strong inertial effects

NASA Astrophysics Data System (ADS)

Iovine, G.; D'Ambrosio, D.; Di Gregorio, S.

2005-03-01

In modelling complex a-centric phenomena which evolve through local interactions within a discrete time-space, cellular automata (CA) represent a valid alternative to standard solution methods based on differential equations. Flow-type phenomena (such as lava flows, pyroclastic flows, earth flows, and debris flows) can be viewed as a-centric dynamical systems, and they can therefore be properly investigated in CA terms. SCIDDICA S 4a is the last release of a two-dimensional hexagonal CA model for simulating debris flows characterised by strong inertial effects. S 4a has been obtained by progressively enriching an initial simplified model, originally derived for simulating very simple cases of slow-moving flow-type landslides. Using an empirical strategy, in S 4a, the inertial character of the flowing mass is translated into CA terms by means of local rules. In particular, in the transition function of the model, the distribution of landslide debris among the cells is obtained through a double cycle of computation. In the first phase, the inertial character of the landslide debris is taken into account by considering indicators of momentum. In the second phase, any remaining debris in the central cell is distributed among the adjacent cells, according to the principle of maximum possible equilibrium. The complexities of the model and of the phenomena to be simulated suggested the need for an automated technique of evaluation for the determination of the best set of global parameters. Accordingly, the model is calibrated using a genetic algorithm and by considering the May 1998 Curti-Sarno (Southern Italy) debris flow. The boundaries of the area affected by the debris flow are simulated well with the model. Errors computed by comparing the simulations with the mapped areal extent of the actual landslide are smaller than those previously obtained without genetic algorithms. As the experiments have been realised in a sequential computing environment, they could be improved by adopting a parallel environment, which allows the performance of a great number of tests in reasonable times.

Viscous slip coefficients for binary gas mixtures measured from mass flow rates through a single microtube

NASA Astrophysics Data System (ADS)

Yamaguchi, H.; Takamori, K.; Perrier, P.; Graur, I.; Matsuda, Y.; Niimi, T.

2016-09-01

The viscous slip coefficient for helium-argon binary gas mixture is extracted from the experimental values of the mass flow rate through a microtube. The mass flow rate is measured by the constant-volume method. The viscous slip coefficient was obtained by identifying the measured mass flow rate through a microtube with the corresponding analytical expression, which is a function of the Knudsen number. The measurements were carried out in the slip flow regime where the first-order slip boundary condition can be applied. The measured viscous slip coefficients of binary gas mixtures exhibit a concave function of the molar ratio of the mixture, showing a similar profile with numerical results. However, from the detailed comparison between the measured and numerical values with the complete and incomplete accommodation at a surface, it is inappropriate to estimate the viscous slip coefficient for the mixture numerically by employing separately measured tangential momentum accommodation coefficient for each component. The time variation of the molar ratio in the downstream chamber was measured by sampling the gas from the chamber using the quadrupole mass spectrometer. In our measurements, it is indicated that the volume flow rate of argon is larger than that of helium because of the difference in the tangential momentum accommodation coefficient.

Examination of the Relation between TEOG Score of Turkish Revolution History and Kemalism Course and Reading Comprehension Skill (An Example of Explanatory Sequential Mixed Design)

ERIC Educational Resources Information Center

Yuvaci, Ibrahim; Demir, Selçuk Besir

2016-01-01

This paper is aimed to determine the relation between reading comprehension skill and TEOG success. In this research, a mixed research method, sequential explanatory mixed design, is utilized to examine the relation between reading comprehension skills and TEOG success of 8th grade students throughly. In explanatory sequential mixed design…

Evaluation of Phosphate Fertilizers for the Immobilization of Cd in Contaminated Soils

PubMed Central

Yan, Yin; Zhou, Yi Qun; Liang, Cheng Hua

2015-01-01

A laboratory investigation was conducted to evaluate the efficiency of four phosphate fertilizers, including diammonium phosphate (DAP), potassium phosphate monobasic (MPP), calcium superphosphateon (SSP), and calcium phosphate tribasic (TCP), in terms of the toxicity and bioavailability of Cd in contaminated soils. The efficiency of immobilization was evaluated on the basis of two criteria: (a) the reduction of extractable Cd concentration below the TCLP regulatory level and (b) the Cd changes associated with specific operational soil fractions on the basis of sequential extraction data. Results showed that after 50 d immobilization, the extractable concentrations of Cd in DAP, MPP, SSP, and TCP treated soils decreased from 42.64 mg/kg (in the control) to 23.86, 21.86, 33.89, and 35.59 mg/kg, respectively, with immobilization efficiency in the order of MPP > DAP > SSP > TCP. Results from the assessment of Cd speciation via the sequential extraction procedure revealed that the soluble exchangeable fraction of Cd in soils treated with phosphate fertilizers, especially TCP, was considerably reduced. In addition, the reduction was correspondingly related to the increase in the more stable forms of Cd, that is, the metal bound to manganese oxides and the metal bound to crystalline iron oxides. Treatment efficiency increased as the phosphate dose (according to the molar ratio of PO4/Cd) increased. Immobilization was the most effective under the molar ratio of PO4/Cd at 4:1. PMID:25915051

Chemical and physiological metal bioaccessibility assessment in surface bottom sediments from the Deba River urban catchment: Harmonization of PBET, TCLP and BCR sequential extraction methods.

PubMed

Unda-Calvo, Jessica; Martínez-Santos, Miren; Ruiz-Romera, Estilita

2017-04-01

In the present study, the physiologically based extraction test PBET (gastric and intestinal phases) and two chemical based extraction methods, the toxicity characteristic leaching procedure (TCLP) and the sequential extraction procedure BCR 701 (Community Bureau of Reference of the European Commission) have been used to estimate and evaluate the bioaccessibility of metals (Fe, Mn, Zn, Cu, Ni, Cr and Pb) in sediments from the Deba River urban catchment. The statistical analysis of data and comparison among physiological and chemical methods have highlighted the relevance of simulate the gastrointestinal tract environment since metal bioaccessibility seems to depend on water and sediment properties such as pH, redox potential and organic matter content, and, primordially, on the form in which metals are present in the sediment. Indeed, metals distributed among all fractions (Mn, Ni, Zn) were the most bioaccessible, followed by those predominantly bound to oxidizable fraction (Cu, Cr and Pb), especially near major urban areas. Finally, a toxicological risk assessment was also performed by determining the hazard quotient (HQ), which demonstrated that, although sediments from mid- and downstream sampling points presented the highest metal bioaccessibilities, were not enough to have adverse effects on human health, Cr being the most potentially toxic element. Copyright © 2017 Elsevier Inc. All rights reserved.

Influence of residual oxygen-15-labeled carbon monoxide radioactivity on cerebral blood flow and oxygen extraction fraction in a dual-tracer autoradiographic method.

PubMed

Iwanishi, Katsuhiro; Watabe, Hiroshi; Hayashi, Takuya; Miyake, Yoshinori; Minato, Kotaro; Iida, Hidehiro

2009-06-01

Cerebral blood flow (CBF), cerebral metabolic rate of oxygen (CMRO(2)), oxygen extraction fraction (OEF), and cerebral blood volume (CBV) are quantitatively measured with PET with (15)O gases. Kudomi et al. developed a dual tracer autoradiographic (DARG) protocol that enables the duration of a PET study to be shortened by sequentially administrating (15)O(2) and C(15)O(2) gases. In this protocol, before the sequential PET scan with (15)O(2) and C(15)O(2) gases ((15)O(2)-C(15)O(2) PET scan), a PET scan with C(15)O should be preceded to obtain CBV image. C(15)O has a high affinity for red blood cells and a very slow washout rate, and residual radioactivity from C(15)O might exist during a (15)O(2)-C(15)O(2) PET scan. As the current DARG method assumes no residual C(15)O radioactivity before scanning, we performed computer simulations to evaluate the influence of the residual C(15)O radioactivity on the accuracy of measured CBF and OEF values with DARG method and also proposed a subtraction technique to minimize the error due to the residual C(15)O radioactivity. In the simulation, normal and ischemic conditions were considered. The (15)O(2) and C(15)O(2) PET count curves with the residual C(15)O PET counts were generated by the arterial input function with the residual C(15)O radioactivity. The amounts of residual C(15)O radioactivity were varied by changing the interval between the C(15)O PET scan and (15)O(2)-C(15)O(2) PET scan, and the absolute inhaled radioactivity of the C(15)O gas. Using the simulated input functions and the PET counts, the CBF and OEF were computed by the DARG method. Furthermore, we evaluated a subtraction method that subtracts the influence of the C(15)O gas in the input function and PET counts. Our simulations revealed that the CBF and OEF values were underestimated by the residual C(15)O radioactivity. The magnitude of this underestimation depended on the amount of C(15)O radioactivity and the physiological conditions. This underestimation was corrected by the subtraction method. This study showed the influence of C(15)O radioactivity in DARG protocol, and the magnitude of the influence was affected by several factors, such as the radioactivity of C(15)O, and the physiological condition.

Extraction and speciation of arsenic in lacustrine sediments

USGS Publications Warehouse

Ficklin, W.H.

1990-01-01

Arsenic was partially extracted with 4.OM hydrochloric acid, from samples collected at 25-cm intervals in a 350-cm column of sediment at Milltown Reservoir, Montana and from a 60-cm core of sediment collected at the Cheyenne River Embayment of Lake Oahe, South Dakota. The sediment in both reservoirs is highly contaminated with arsenic. The extracted arsenic was separated into As(III) and As(V) on acetate form Dowex 1-X8 ion-exchange resin with 0.12M HCl eluent. Residual arsenic was sequentially extracted with KClO3 and HCl. Arsenic was determined by graphite-furnace atomic-absorption spectrometry. The analytical results define oxidized and reduced zones in the sediment columns. ?? 1990.

Method and apparatus for high-efficiency direct contact condensation

DOEpatents

Bharathan, D.; Parent, Y.; Hassani, A.V.

1999-07-20

A direct contact condenser having a downward vapor flow chamber and an upward vapor flow chamber, wherein each of the vapor flow chambers includes a plurality of cooling liquid supplying pipes and a vapor-liquid contact medium disposed thereunder to facilitate contact and direct heat exchange between the vapor and cooling liquid. The contact medium includes a plurality of sheets arranged to form vertical interleaved channels or passageways for the vapor and cooling liquid streams. The upward vapor flow chamber also includes a second set of cooling liquid supplying pipes disposed beneath the vapor-liquid contact medium which operate intermittently in response to a pressure differential within the upward vapor flow chamber. The condenser further includes separate wells for collecting condensate and cooling liquid from each of the vapor flow chambers. In alternate embodiments, the condenser includes a cross-current flow chamber and an upward flow chamber, a plurality of upward flow chambers, or a single upward flow chamber. The method of use of the direct contact condenser of this invention includes passing a vapor stream sequentially through the downward and upward vapor flow chambers, where the vapor is condensed as a result of heat exchange with the cooling liquid in the contact medium. The concentration of noncondensable gases in the resulting condensate-liquid mixtures can be minimized by controlling the partial pressure of the vapor, which depends in part upon the geometry of the vapor-liquid contact medium. In another aspect of this invention, the physical and chemical performance of a direct contact condenser can be predicted based on the vapor and coolant compositions, the condensation conditions, and the geometric properties of the contact medium. 39 figs.

Method and apparatus for high-efficiency direct contact condensation

DOEpatents

Bharathan, Desikan; Parent, Yves; Hassani, A. Vahab

1999-01-01

A direct contact condenser having a downward vapor flow chamber and an upward vapor flow chamber, wherein each of the vapor flow chambers includes a plurality of cooling liquid supplying pipes and a vapor-liquid contact medium disposed thereunder to facilitate contact and direct heat exchange between the vapor and cooling liquid. The contact medium includes a plurality of sheets arranged to form vertical interleaved channels or passageways for the vapor and cooling liquid streams. The upward vapor flow chamber also includes a second set of cooling liquid supplying pipes disposed beneath the vapor-liquid contact medium which operate intermittently in response to a pressure differential within the upward vapor flow chamber. The condenser further includes separate wells for collecting condensate and cooling liquid from each of the vapor flow chambers. In alternate embodiments, the condenser includes a cross-current flow chamber and an upward flow chamber, a plurality of upward flow chambers, or a single upward flow chamber. The method of use of the direct contact condenser of this invention includes passing a vapor stream sequentially through the downward and upward vapor flow chambers, where the vapor is condensed as a result of heat exchange with the cooling liquid in the contact medium. The concentration of noncondensable gases in the resulting condensate-liquid mixtures can be minimized by controlling the partial pressure of the vapor, which depends in part upon the geometry of the vapor-liquid contact medium. In another aspect of this invention, the physical and chemical performance of a direct contact condenser can be predicted based on the vapor and coolant compositions, the condensation conditions. and the geometric properties of the contact medium.

Pollution potential leaching index as a tool to assess water leaching risk of arsenic in excavated urban soils.

PubMed

Li, Jining; Kosugi, Tomoya; Riya, Shohei; Hashimoto, Yohey; Hou, Hong; Terada, Akihiko; Hosomi, Masaaki

2018-01-01

Leaching of hazardous trace elements from excavated urban soils during construction of cities has received considerable attention in recent years in Japan. A new concept, the pollution potential leaching index (PPLI), was applied to assess the risk of arsenic (As) leaching from excavated soils. Sequential leaching tests (SLT) with two liquid-to-solid (L/S) ratios (10 and 20Lkg -1 ) were conducted to determine the PPLI values, which represent the critical cumulative L/S ratios at which the average As concentrations in the cumulative leachates are reduced to critical values (10 or 5µgL -1 ). Two models (a logarithmic function model and an empirical two-site first-order leaching model) were compared to estimate the PPLI values. The fractionations of As before and after SLT were extracted according to a five-step sequential extraction procedure. Ten alkaline excavated soils were obtained from different construction projects in Japan. Although their total As contents were low (from 6.75 to 79.4mgkg -1 ), the As leaching was not negligible. Different L/S ratios at each step of the SLT had little influence on the cumulative As release or PPLI values. Experimentally determined PPLI values were in agreement with those from model estimations. A five-step SLT with an L/S of 10Lkg -1 at each step, combined with a logarithmic function fitting was suggested for the easy estimation of PPLI. Results of the sequential extraction procedure showed that large portions of more labile As fractions (non-specifically and specifically sorbed fractions) were removed during long-term leaching and so were small, but non-negligible, portions of strongly bound As fractions. Copyright © 2017 Elsevier Inc. All rights reserved.

Effect of chemical pollution on forms of 137Cs, 90Sr and 239,240Pu in arctic soil studied by sequential extraction.

PubMed

Puhakainen, M; Riekkinen, I; Heikkinen, T; Jaakkola, T; Steinnes, E; Rissanen, K; Suomela, M; Thørring, H

2001-01-01

The aim of the present study was to determine the forms of 137Cs, 90Sr and 239,240Pu occurring in different soil horizons using sequential extraction of samples taken from four sites located along a pollution gradient from the copper-nickel smelter at Monchegorsk in the Kola Peninsula, Russia, and from a reference site in Finnish Lapland in 1997. A selective sequential-leaching procedure was employed using a modification of the method of Tessier, Cambell and Bisson ((1979). Analytical Chemistry, 51, 844-851). For 137Cs the organic (O) and uppermost mineral (E1) layer were studied, for 90Sr and 239,240Pu only the uppermost organic layer (Of). The fraction of 137Cs occurring in readily exchangeable form in the organic layer was about 50% at the reference site and decreased as a function of pollution, being 15% at the most polluted site in the Kola Peninsula. There was a clear positive correlation in the O layer between the distance from the smelter and the percentage of 137Cs extracted in the readily exchangeable fraction (Spearman correlation rsp = 0.7805, p = 0.0001), whereas in the E1 layer no correlation was evident. The distribution of 90Sr in the Of layer was similar at all sites, with the highest amounts occurring in exchangeable form and bound to organic matter, whereas stable Sr showed a somewhat different distribution with the highest amount in the oxide fraction. Most of the 239,240Pu was bound to organic matter. Chemical pollution affected the exchangeable fraction of 239,240Pu, which was about 1% at the most polluted site and 4-6% at the other sites.

Fractionation and ecotoxicological implication of potentially toxic metals in sediments of three urban rivers and the Lagos Lagoon, Nigeria, West Africa.

PubMed

Oyeyiola, Aderonke O; Davidson, Christine M; Olayinka, Kehinde O; Alo, Babajide I

2014-11-01

The potential environmental impact of sediment-bound Cd, Cr, Cu, Pb and Zn in three trans-urban rivers in Lagos state and in the Lagos Lagoon was assessed by use of the modified Community Bureau of Reference (BCR) sequential extraction. The quality of the data was checked using BCR CRM 143R and BCR CRM 701. Good agreement was obtained between found and certified/indicative values. Of the rivers, the Odo-Iyaalaro, was generally the most contaminated and the Ibeshe the least. Higher concentrations of metals were generally found in the dry season compared to the wet season. Cadmium and Zn were released mostly in the acid exchangeable step of the sequential extraction, indicating that they have the greatest potential mobility and bioavailability of the analytes studied. Chromium and Cu were associated mainly with the reducible and oxidisable fractions, and Pb predominantly with the reducible and residual fractions. Sediments with the highest pseudototal analyte concentrations also released higher proportions of analytes earlier in the sequential extraction procedure. The study suggests that, during the dry season, potentially toxic metals (PTM) may accumulate in sediments in relatively labile forms that are released and can potentially be transported or bioaccumulate in the rainy season. Application of risk assessment codes and Hankanson potential risk indices indicated that Cd was the element of greatest concern in the Lagos Lagoon system. The study indicated that there is a need to strengthen environmental management and pollution control measures to reduce risk from PTM, but that even relatively simple strategies, such as seasonal restrictions on dredging and fishing, could be beneficial.

Simulation of ground-water flow and areas contributing recharge to extraction wells at the Drake Chemical Superfund Site, City of Lock Haven and Castanea Township, Clinton County, Pennsylvania

USGS Publications Warehouse

Schreffler, Curtis L.

2006-01-01

Extensive remediation of the Drake Chemical Superfund Site has been ongoing since 1983. Contaminated soils were excavated and incinerated on site between 1996 and 1999. After 1999, remedial efforts focused on contaminated ground water. A ground-water remediation system was started in November 2000. The source area of the contaminated ground water was assumed to be the zone 1 area on the Drake Chemical site. The remedial system was designed to capture ground water migrating from zone 1. Also, the remediation system was designed to pump and treat the water in an anoxic environment and re-infiltrate the treated water underground through an infiltration gallery that is hydrologically downgradient of the extraction wells. A numerical ground-water flow model of the surrounding region was constructed to simulate the areas contributing recharge to remedial extraction wells installed on the Drake Chemical site. The three-dimensional numerical flow model was calibrated using the parameter-estimation process in MODFLOW-2000. The model included three layers that represented three poorly sorted alluvial sediment units that were characterized from geologic well and boring logs. Steady-state ground-water flow was simulated to estimate the areas contributing recharge to three extraction wells for three different pumping scenarios--all wells pumping at 2 gallons per minute, at approximately 5 gallons per minute, and at 8 gallons per minute. Simulation results showed the contributing areas to the three extraction wells encompassed 92 percent of zone 1 at a pumping rate of approximately 5 gallons per minute. The contributing areas did not include a very small area in the southwestern part of zone 1 when the three extraction wells were pumped at approximately 5 gallons per minute. Pumping from a fourth extraction well in that area was discontinued early in the operation of the remediation system because the ground water in that area met performance standards. The areas contributing recharge to the three extraction wells did encompass zone 1 at a pumping rate of 8 gallons per minute. At pumping rates of 2 gallons per minute, the contributing areas for the three extraction wells did not encompass zone 1.