These are representative sample records from Science.gov related to your search topic.
For comprehensive and current results, perform a real-time search at Science.gov.
1

Utilization of Structured Packing for Energy Savings in Distillation and Absorption Columns  

E-print Network

capacity is required or where there a e severe and internals is less than six months. This assumes that coking problems, Style II F1exigrid 0 packing, hich has the F1exipac@ structured packing can be installed during very low holdUp and minimum dead..."UTILIZATION OF STRUCTURED PACKING FOR ENERGY SAVINGS IN DISTILLATION AND ABSORPTION COLUMNS" O. Jeffrey Berven and Wendell E. Howard Koch Engineering Company, Inc. Wi chita, Kansas As the need to reduce production costs causes...

Berven, O. J.; Howard, W. E.

2

Counter-current operation of structured catalytically packed distillation columns: pressure drop, holdup and mixing  

Microsoft Academic Search

Structured packed columns, in which the catalyst particles are enclosed within wire gauze envelopes (“sandwiches”) are promising reactor configurations for reactive distillation and hydroconversions. By allowing preferential channels for the gas and liquid phases, counter-current operation is achieved even for millimeter sized catalyst particles without the problem of flooding. This paper reports the results of a comprehensive experimental study of

J. Ellenberger; R. Krishna

1999-01-01

3

The influence of vapour capacitance on the composition dynamics of packed distillation columns  

NASA Astrophysics Data System (ADS)

A general transfer function matrix (TFM) expression is derived for the composition dynamics of ideal packed columns that are statically symmetrical, but are dynamically asymmetric, i.e., having a nonunity vapor/liquid capacitance ratio, c. For the special case of c = o, the system TFM is derived completely analytically to produce a parametric TFM, resembling that for c = 1. The result is successfully tested at high and zero frequencies against the initial and final values of the system step responses determined analytically and by time domain simulation. Complete inverse Nyquist diagrams are presented and compared with the c = 1 case. It is noted that whereas for c = 1, the system response for long columns is nonminimum phase, for c = o, the system behaves in a nonstrictly proper fashion with an abrupt initial negative response of magnitude similar to the nonminimum phase dip produced when c = 1. Hence, the variation of c does not greatly influence the general response characteristics of packed columns.

Edwards, J. B.; Guilandoust, M.

1981-11-01

4

Energy Saving in Distillation Using Structured Packing and Vapor Recompression  

E-print Network

distillation application, a column with a small pressure drop is especially important. An example of a vacuum distillation which is made suitable for VRC with use of structured packing is sep~ration of styrene and ethylbenzene. Approximately 70...% of the world's styrene capac ty is now processed through columns filled with Flex pac? or Mellapak structured packings. In conventio al column operation, energy savings of 20 to 30% re obtained by replacing trays or dumped packings Other benefits...

Hill, J.H.

5

Effects of System Densities on Distillation Column Performance  

Microsoft Academic Search

Distillation experiments were carried out on three binary systems (ethanol—butanol, ethanol—propan-2-ol, and propan-2-ol-butanol) in a 0.1-m internal diameter glass column packed with 8 mm diameter Raschig rings. The experiments were performed under total reflux conditions and at atmospheric pressure. The data collected on column performance showed that performance declined with increasing average bulk liquid density. The results also lend credence

S. O. Fasesan; S. A. Sanni; E. A. Taiwo

1998-01-01

6

The Scaleup of Structured Packing from Distillation Pilot Plant Testing to Commercial Application  

E-print Network

The Scaleup of Structured Packing From Distillation Pilot Plant Testing to Commercial Application O. Jeffrey'Berven and Michael A. Ulowetz Koch Engineering Company, Inc. Wichita, Kansas Structured packing is being utilized more and more... in the process industry for increased efficiency, greater capacity, and energy savings in distillation columns. Pilot plant testing of the actual chemical system using commercially available structured packing is invaluable, but years of experience in pilot...

Berven, O. J.; Ulowetz, M. A.

7

Intelligent fuzzy supervisory control for distillation columns  

E-print Network

to be controlled. In many difficult process situations such as steelmaking furnaces [7], cement kilns [13], presses in the glass industry [4] and distillation columns [12], such models do not exist. While there are a variety of adaptive techniques which can...

Santhanam, Srinivasan

2012-06-07

8

Method for packed column separations and purifications  

SciTech Connect

The invention encompasses a method of packing and unpacking a column chamber. A mixture of a fluid and a matrix material are introduced through a column chamber inlet so that the matrix material is packed within a column chamber to form a packed column. The column chamber having the column chamber inlet or first port for receiving the mixture further has an outlet port and an actuator port. The outlet port is partially closed for capturing the matrix material and permitting the fluid to flow therepast by rotating relative one to the other of a rod placed in the actuator port. Further rotation relative one to the other of the rod and the column chamber opens the outlet and permits the matrix material and the fluid to flow therethrough thereby unpacking the matrix material from the column chamber.

Holman, David A. (Richland, WA); Bruckner-Lea, Cynthia J. (Richland, WA); Brockman, Fred J. (Kennewick, WA); Chandler, Darrell P. (Richland, WA)

2006-08-15

9

Final Report, Distillation Column Flooding Predictor  

SciTech Connect

The Flooding Predictor is an advanced process control strategy comprising a patented pattern-recognition methodology that identifies pre-flood patterns discovered to precede flooding events in distillation columns. The grantee holds a U.S. patent on the modeling system. The technology was validated at the Separations Research Program, The University of Texas at Austin under a grant from the U. S. Department of Energy, Inventions & Innovation Program. Distillation tower flooding occurs at abnormally high vapor and/or liquid rates. The loss in tray efficiencies is attributed to unusual behavior of liquid inventories inside the column leading to conditions of flooding of the space in between trays with liquid. Depending on the severity of the flood condition, consequences range from off spec products to equipment damage and tower shutdown. This non-intrusive pattern recognition methodology, processes signal data obtained from existing column instrumentation. Once the pattern is identified empirically, it is modeled and coded into the plant's distributed control system. The control system is programmed to briefly "unload" the tower each time the pattern appears. The unloading takes the form of a momentary reduction in column severity, e.g., decrease bottom temperature, reflux or tower throughput. Unloading the tower briefly at the pre-flood state causes long-term column operation to become significantly more stable - allowing an increase in throughput and/or product purity. The technology provides a wide range of value between optimization and flooding. When a distillation column is not running at capacity, it should be run in such a way ("pushed") that optimal product purity is achieved. Additional benefits include low implementation and maintenance costs, and a high level of console operator acceptance. The previous commercial applications experienced 98% uptime over a four-year period. Further, the technology is unique in its ability to distinguish between different flooding mechanisms within the same tower, e.g., liquid and jet flooding.

George E. Dzyacky

2003-05-31

10

A Versatile, Automatic Chromatographic Column Packing Device  

ERIC Educational Resources Information Center

Describes an inexpensive apparatus for packing liquid and gas chromatographic columns of high efficiency. Consists of stainless steel support struts, an Automat Getriebmotor, and an associated three-pulley system capable of 10, 30, and 300 rpm. (MLH)

Barry, Eugene F.; And Others

1977-01-01

11

Continuous and Batch Distillation in an Oldershaw Tray Column  

ERIC Educational Resources Information Center

The importance of distillation in the separation field prompts the inclusion of distillation experiments in the chemical engineering curricula. This work describes the performance of an Oldershaw column in the rectification of a cyclohexane/n-heptane mixture. Total reflux distillation, continuous rectification under partial reflux, and batch…

Silva, Carlos M.; Vaz, Raquel V.; Santiago, Ana S.; Lito, Patricia F.

2011-01-01

12

Evaluation of Packed Columns in Supercritical Extraction Processes  

E-print Network

--------- EVALUATION OF PACKED COLUMNS IN SUPERCRITICAL EXTRACTION PROCESSES Paul J. Rathkamp, James R. Fair, Jimmy L. Humphrey The University of Texas at Austin Austin, Texas ABSTRACT The purpose of the present work is to add to the base... of knowledge in the use of packed columns when used in supercritical extraction service. Ex perimental studies were performed on a one-inch di ameter supercritical fluid extraction column oper ated in both spray and packed column arrangements. The packing...

Rathkamp, P. J.; Fair, J. R.; Humphrey, J. L.

13

[Packed glass capillary column with multi-cores].  

PubMed

The paper describes the preparation of the columns with multi-cores and their plate heights, optimum gas velocity, minimum plate heights (HETP) and corresponding pressure drop (deltaP=Pi-Po) were measured. It is found that HETP increases as core number increase, but column pressure drop (deltaP) decrease with increase of core number. The conclusion is: 1. The column with multi-cores have a better permeability than the conventional packed capillary column. Although its column efficiency is lower than that of the conventional one when packed particles is in the same column size, the comprehensive properties (N/deltaP) are evidently superior than the conventional capillary column. 2. The pressure drop decreasesas the number and diameter of the core in packed capillary column increase. 3. When packed column particle size gets smaller, column efficiency gets higher, but the particle inlay bacomes difficult. The existence of the cores will make the column efficiency get some loss, but it can improve the column permeability and the inlaid geomery. 4. In considering pressure drop, HETP and the particle inlaid condition in column fabrication as a whole, the optimum column type is the packed capillary column with three cores. 5. Ideal column size is: deltad=1-1. 5dp,d=1-2dp,n> or =3, dp=140-250 mesh. PMID:15739425

Liu, X; Yang, H; Lu, W

1997-01-01

14

Miniature Distillation Column for Producing LOX From Air  

NASA Technical Reports Server (NTRS)

The figure shows components of a distillation column intended for use as part of a system that produces high-purity liquid oxygen (LOX) from air by distillation. (The column could be easily modified to produce high-purity liquid nitrogen.) Whereas typical industrial distillation columns for producing high-purity liquid oxygen and/or nitrogen are hundreds of feet tall, this distillation column is less than 3 ft (less than about 0.9 m) tall. This column was developed to trickle-charge a LOX-based emergency oxygen system (EOS) for a large commercial aircraft. A description of the industrial production of liquid oxygen and liquid nitrogen by distillation is prerequisite to a meaningful description of the present miniaturized distillation column. Typically, such industrial production takes place in a chemical processing plant in which large quantities of high-pressure air are expanded in a turboexpander to (1) recover a portion of the electrical power required to compress the air and (2) partially liquefy the air. The resulting two-phase flow of air is sent to the middle of a distillation column. The liquid phase is oxygen-rich, and its oxygen purity increases as it flows down the column. The vapor phase is nitrogen-rich and its nitrogen purity increases as it flows up the column. A heater or heat exchanger, commonly denoted a reboiler, is at the bottom of the column. The reboiler is so named because its role is to reboil some of the liquid oxygen collected at the bottom of the column to provide a flow of oxygen-rich vapor. As the oxygen-rich vapor flows up the column, it absorbs the nitrogen in the down-flowing liquid by mass transfer. Once the vapor leaves the lower portion of the column, it interacts with down-flowing nitrogen liquid that has been condensed in a heat exchanger, commonly denoted a condenser, at the top of the column. Liquid oxygen and liquid nitrogen products are obtained by draining some of the purified product at the bottom and top of the column, respectively. Because distillation is a mass-transfer process, the purity of the product(s) can be increased by increasing the effectiveness of the mass-transfer process (increasing the mass-transfer coefficient) and/or by increasing the available surface area for mass transfer through increased column height. The diameter of a distillation column is fixed by pressure-drop and mass-flow requirements. The approach taken in designing the present distillation column to be short yet capable of yielding a product of acceptably high purity was to pay careful attention to design details that affect mass-transfer processes.

Rozzi, Jay C.

2006-01-01

15

Double-column gas chromatography using packed pre-columns and glass capillary main columns.  

PubMed

Methods of column switching are described that make possible back-flushing, heart cutting and trapping. Conventional packed columns are employed as pre-columns for their high sample capacity, and glass capillary columns are used as the main columns for their high separation efficiency. Some typical examples of the application of double-column gas chromatography are presented: (1) solvent cutting for identification and exact quantitative determination of a phosphorus ester impurity in a sample of wheat flour (including trapping); (2) separation of trace amounts of methyl esters of fatty acids by means of back-flushing and trapping; (3) enrichment technique using trapping of trace elements in the front section of the capillary (plus solvent cutting, multiple injection and back-flushing); and (4) coupling a nitrogen-selective detector to the capillary main column to gain additional information. To illustrate the trapping effect, the separation number was determined with and without trapping. PMID:548547

Blass, W; Riegner, K; Hulpke, H

1979-04-21

16

Aspects of column fabrication for packed capillary electrochromatography.  

PubMed

Various parameters have been evaluated to develop a process for optimization of column manufacture for packed capillary electrochromatography (CEC). Spherisorb ODS-1 was packed into 75 microm I.D. capillaries to establish a standard set of packing conditions to afford high-performance columns free of voids. Numerous silica-based packing materials including porous and non-porous reversed-phase and ion-exchange phases were employed to evaluate the applicability of the standard conditions. Success of column manufacture and performance demonstrate a relationship to the colligative properties of the packing materials under the applied conditions. Frequently encountered difficulties arising from inadequate column conditioning and void formation in the packed bed are identified and discussed. PMID:10961326

Angus, P D; Demarest, C W; Catalano, T; Stobaugh, J F

2000-07-28

17

Mass transfer in countercurrent packed columns: Application to supercritical CO[sub 2] extraction of terpenes  

SciTech Connect

Supercritical fluid extraction (SFE) is an alternative separation method to more conventional processes such as liquid extraction and distillation. However, up to now, few works have been devoted to the investigation of the efficiency of countercurrent packed columns under supercritical conditions from a mass transfer point of view. Mass transfer in a countercurrent column, filled with structured gauze packing, was measured for the separation of a mixture of terpenes (d-limonene/1,8-cineole) by supercritical carbon dioxide, at 313 and 318 K and pressures up to 9 MPa. The extraction efficiency was determined in terms of the overall mass transfer coefficient. Operating lines for this process had an appreciable curvature due to a high miscibility of the two contacting phases. The real slope of these lines had to be estimated. Available mass transfer models for packed columns predicted efficiencies diverging to a great extent from the experimental results.

Simoes, P.C.; Matos, H.A.; Carmelo, P.J.; Gomes de Azevedo, E.; Nunes da Ponte, M. (Univ. Nova de Lisboa, Monte de Caparica (Portugal). Faculdade de Ciencias e Tecnologia)

1995-02-01

18

Applying risk assessment principles to a batch distillation column  

SciTech Connect

Some distillation columns in the chemical industry are operated in batch mode with a fairly short operating cycle. At the end of each cycle the columns are cooled and recharged. During the cooling cycle, air will be drawn into the column by the action of a vacuum relief valve. Consequently, for a finite portion of the operating cycle a flammable mixture will exist in the column. Here we evaluate the risk posed by such an operation to see if a mitigation measure is justified. We develop a fault tree and estimate the frequency of ignition by all possible ignition sources. By comparing the risk reduction attainable by installing a lightning protection system with that attainable by using an inert blanketing system the lightning protection system is found to be the preferred solution. It provides about the same risk reduction at a lower overall cost. 2 refs., 3 figs., 4 tabs.

Woodward, J.L.; Moosemiller, M.D. [DNV Technica, Columbus, OH (United States)] [DNV Technica, Columbus, OH (United States)

1996-12-31

19

A cryogenic distillation column for the XENON1T experiment  

NASA Astrophysics Data System (ADS)

The XENON collaboration aims for the direct detection of cold dark matter in form of weakly interacting massive particles (WIMPs). A dual phase time projection chamber filled with liquid xenon is used to detect the WIMP-nucleon interaction. For the next generation experiment XENON1T with an active target mass of 1 ton of xenon, a new distillation column to remove krypton out of xenon to a concentration of < 5 × 10?13 (0.5 ppt) natural krypton in xenon is designed and tested at the Institut für Kernphysik, Universitat Munster. The experimental setup together with two diagnostic tools is presented, as well as one stability test of a 11 hour distillation run at the designed flowrate of 3 kg per hour.

Rosendahl, S.; Brown, E.; Cristescu, I.; Fieguth, A.; Huhmann, C.; Murra, M.; Weinheimer, C.

2014-11-01

20

Distillation: Energy Savings and Other Benefits From the Use of High Efficiency Packings  

E-print Network

DISTILLATION: ENERGY SAVINGS AND OTHER BENEFITS. FROM THE USE OF HIGH-EFFICIENCY PACKINGS -. Jose L. Bravo, James R. Fair, and Jimmy L. Humpnrey The University of Texas at Austin Austin, Texas ABSTRACT A great deal of attention has been... focused lately on the use of high-efficiency packings for distillation applications. This paper discusses benefits that can be derived from the use of these devices. In parti~ular, the reduction in energy requirements for a given separation...

Bravo, J. L.; Fair, J. R.; Humphrey, J. L.

21

Immobilization of enzymes on polytetrafluoroethylene particles packed in HPLC columns  

SciTech Connect

The use of polytetrafluoroethylene particles packed in short, high performance liquid chromatography columns for the immobilization of enzymes is examined. In particular, lactate dehydrogenase chosen as a model system was investigated with regard to activity and stability when immobilized on polytetrafluoroethylene. (Refs. 7).

Danielson, N.D.; Siergiej, R.W.

1981-08-01

22

Temperature effects on nano-LC column packing technology.  

PubMed

We investigated the effect of temperature on the packing procedure of nano-LC columns (up to 50 cm) and on their performance. Several slurries of stationary phase were prepared using different solvent mixtures. Their stability was evaluated at several temperatures: 70°C, 50°C, and room temperature. At the higher temperature (70°C) the suspensions resulted to be stable for a longer time. For each slurry, we compared nano-LC columns packed with ultrasounds at 70°C and at room temperature. All the columns were tested with a standard mixture at 70°C, to reduce the solvent viscosity and the backpressure. Main chromatographic parameters such as the asymmetry factor, As, the reduced plate high, h, pattern in a Van Deemter plot, the total porosity, ?(t), and the permeability, k, were calculated and discussed. One of the nano-LC columns was used to separate a mixture of pesticides in a LC-MS system with an electron ionization LC-MS interface (Direct-EI). From our knowledge, this is the first study on the role of temperature in the efficiency of slurry-packing procedure. PMID:22761136

Leonardis, Irene; Capriotti, Fabiana; Cappiello, Achille; Famiglini, Giorgio; Palma, Pierangela

2012-07-01

23

Optimization of a Diabatic Distillation Column with Sequential Heat Edward Steven Jimenez and Peter Salamon*  

E-print Network

(the reboiler) and one heat sink (the condenser), a diabatic column uses a heat exchanger at each trayOptimization of a Diabatic Distillation Column with Sequential Heat Exchangers Edward Steven of Copenhagen, Copenhagen, Denmark Diabatic distillation is a separation process in which heat is transferred

Salamon, Peter

24

METHOD TO TEST ISOTOPIC SEPARATION EFFICIENCY OF PALLADIUM PACKED COLUMNS  

SciTech Connect

The isotopic effect of palladium has been applied in different ways to separate hydrogen isotopes for many years. At Savannah River Site palladium deposited on kieselguhr (Pd/k) is used in a thermal cycling absorption process (TCAP) to purify tritium for over ten years. The need to design columns for different throughputs and the desire to advance the performance of TCAP created the need to evaluate different column designs and packing materials for their separation efficiency. In this work, columns with variations in length, diameter and metal foam use, were tested using an isotope displacement method. A simple computer model was also developed to calculate the number of theoretical separation stages using the test results. The effects of column diameter, metal foam and gas flow rate were identified.

Heung, L; Gregory Staack, G; James Klein, J; William Jacobs, W

2007-06-27

25

Chromate transport through columns packed with surfactant-modified zeolite/zero valent iron pellets  

E-print Network

Chromate transport through columns packed with surfactant-modified zeolite/zero valent iron pellets Chromate transport through columns packed with zeolite/zero valent iron (Z/ZVI) pellets, either untreated of immobile water was responsible for the earlier breakthrough of chromate in columns packed with zeolite

Li, Zhaohui

26

Systems For Column-Based Separations, Methods Of Forming Packed Columns, And Methods Of Purifying Sample Components.  

DOEpatents

The invention encompasses systems for column-based separations, methods of packing and unpacking columns and methods of separating components of samples. In one aspect, the invention includes a method of packing and unpacking a column chamber, comprising: a) packing a matrix material within a column chamber to form a packed column; and b) after the packing, unpacking the matrix material from the column chamber without moving the column chamber. In another aspect, the invention includes a system for column-based separations, comprising: a) a fluid passageway, the fluid passageway comprising a column chamber and a flow path in fluid communication with the column chamber, the flow path being obstructed by a retaining material permeable to a carrier fluid and impermeable to a column matrix material suspended in the carrier fluid, the flow path extending through the column chamber and through the retaining material, the flow path being configured to form a packed column within the column chamber when a suspension of the fluid and the column matrix material is flowed along the flow path; and b) the fluid passageway extending through a valve intermediate the column chamber and the retaining material.

Egorov, Oleg B. (Richland, WA); O'Hara, Matthew J. (Richland, WA); Grate, Jay W. (West Richland, WA); Chandler, Darrell P. (Richland, WA); Brockman, Fred J. (Kennewick, WA); Bruckner-Lea, Cynthia J. (Richland, WA)

2004-08-24

27

Systems for column-based separations, methods of forming packed columns, and methods of purifying sample components  

DOEpatents

The invention encompasses systems for column-based separations, methods of packing and unpacking columns and methods of separating components of samples. In one aspect, the invention includes a method of packing and unpacking a column chamber, comprising: a) packing a matrix material within a column chamber to form a packed column; and b) after the packing, unpacking the matrix material from the column chamber without moving the column chamber. In another aspect, the invention includes a system for column-based separations, comprising: a) a fluid passageway, the fluid passageway comprising a column chamber and a flow path in fluid communication with the column chamber, the flow path being obstructed by a retaining material permeable to a carrier fluid and impermeable to a column matrix material suspended in the carrier fluid, the flow path extending through the column chamber and through the retaining material, the flow path being configured to form a packed column within the column chamber when a suspension of the fluid and the column matrix material is flowed along the flow path; and b) the fluid passageway extending through a valve intermediate the column chamber and the retaining material.

Egorov, Oleg B. (Richland, WA); O'Hara, Matthew J. (Richland, WA); Grate, Jay W. (West Richland, WA); Chandler, Darrell P. (Richland, WA); Brockman, Fred J. (Kennewick, WA); Bruckner-Lea, Cynthia J. (Richland, WA)

2000-01-01

28

Systems For Column-Based Separations, Methods Of Forming Packed Columns, And Methods Of Purifying Sample Components  

DOEpatents

The invention encompasses systems for column-based separations, methods of packing and unpacking columns and methods of separating components of samples. In one aspect, the invention includes a method of packing and unpacking a column chamber, comprising: a) packing a matrix material within a column chamber to form a packed column; and b) after the packing, unpacking the matrix material from the column chamber without moving the column chamber. In another aspect, the invention includes a system for column-based separations, comprising: a) a fluid passageway, the fluid passageway comprising a column chamber and a flow path in fluid communication with the column chamber, the flow path being obstructed by a retaining material permeable to a carrier fluid and impermeable to a column matrix material suspended in the carrier fluid, the flow path extending through the column chamber and through the retaining material, the flow path being configured to form a packed column within the column chamber when a suspension of the fluid and the column matrix material is flowed along the flow path; and b) the fluid passageway extending through a valve intermediate the column chamber and the retaining material.

Egorov, Oleg B. (Richland, WA); O'Hara, Matthew J. (Richland, WA); Grate, Jay W. (West Richland, WA); Chandler, Darrell P. (Richland, WA); Brockman, Fred J. (Kennewick, WA); Bruckner-Lea, Cynthia J. (Richland, WA)

2006-02-21

29

Development of a fritless packed column for capillary electrochromatography–mass spectrometry  

Microsoft Academic Search

A novel procedure was developed for the fabrication of a fritless packed column for the coupling of capillary electrochromatography (CEC) to mass spectrometry (MS). The process involved the formation of internal tapers on two separate columns. Once the internal tapers are formed and the columns are packed, the untapered ends of each column were joined together by a commercially available

William Bragg; Shahab A. Shamsi

2011-01-01

30

Catalytic distillation process  

DOEpatents

A method is described for conducting chemical reactions and fractionation of the reaction mixture comprising feeding reactants to a distillation column reactor into a feed zone and concurrently contacting the reactants with a fixed bed catalytic packing to concurrently carry out the reaction and fractionate the reaction mixture. For example, a method for preparing methyl tertiary butyl ether in high purity from a mixed feed stream of isobutene and normal butene comprising feeding the mixed feed stream to a distillation column reactor into a feed zone at the lower end of a distillation reaction zone, and methanol into the upper end of said distillation reaction zone, which is packed with a properly supported cationic ion exchange resin, contacting the C[sub 4] feed and methanol with the catalytic distillation packing to react methanol and isobutene, and concurrently fractionating the ether from the column below the catalytic zone and removing normal butene overhead above the catalytic zone.

Smith, L.A. Jr.

1982-06-22

31

Catalytic distillation process  

DOEpatents

A method for conducting chemical reactions and fractionation of the reaction mixture comprising feeding reactants to a distillation column reactor into a feed zone and concurrently contacting the reactants with a fixed bed catalytic packing to concurrently carry out the reaction and fractionate the reaction mixture. For example, a method for preparing methyl tertiary butyl ether in high purity from a mixed feed stream of isobutene and normal butene comprising feeding the mixed feed stream to a distillation column reactor into a feed zone at the lower end of a distillation reaction zone, and methanol into the upper end of said distillation reaction zone, which is packed with a properly supported cationic ion exchange resin, contacting the C.sub.4 feed and methanol with the catalytic distillation packing to react methanol and isobutene, and concurrently fractionating the ether from the column below the catalytic zone and removing normal butene overhead above the catalytic zone.

Smith, Jr., Lawrence A. (Bellaire, TX)

1982-01-01

32

High Performance Trays and Heat Exchangers in Heat Pumped Distillation Columns  

E-print Network

exchangers and distillation trays permits additional energy savings by lower reboiler temperature differences, and reduced reflux requirements for a fixed column height, due to closer tray spacings. This paper surveys the heat pump systems currently...

Wisz, M. W.; Antonelli, R.; Ragi, E. G.

1981-01-01

33

Mass transfer of volatile organics in a packed column  

SciTech Connect

Interphase mass transfer kinetics of several organic compounds in the air-water system were investigated in a countercurrent flow packed column. Oxygen and water mass transfer was studied simultaneously, to provide in-system reference substance data for single-phase limited compounds. Flooding studies were conducted to determine allowable air and water loadings at the desired air:water ratios. Column flooding points were accurately predicted using existing pressure drop correlations. The importance of operating a stripping column well below the loading range was underscored by the finding that the loading region covers a very narrow range of gas rates. Operating pressure drops were from 30 to 50% of predicted values, indicating that predicted column operating expenses may be overestimated using existing pressure drop estimation methods. New equilibrium data and enthalpies of desorption from water in the temperature range of 5 to 20/sup 0/C is reported for cis-1,2-dichloroethene, bromodichloromethane, chlorodibromomethane, bromoform, toluene, chlorobenzene, ethylbenzene, p-xylene, o-xylene, m-dichlorobenzene, p-dichlorobenzene, nitrobenzene and naphthalene. Mass transfer coefficients were estimated using both the Onda correlation and in-system reference substance data. Measured oxygen and water mass transfer coefficients were approximately 50 and 25%, respectively, of values estimated using the Onda correlations. Good agreement was obtained between measured and predicted (using Onda correlations) organic solute mass transfer coefficients under conditions where absorption factors were less than 1.0.

Mumford, R.L.

1987-01-01

34

Application of the theta method to distillation columns where one or more reactions occur per stage  

E-print Network

APPLICATION OF THE THETA METHOD TO DISTILLATION COLUMNS WHERE ONE OR MORE REACTIONS OCCUR PER STAGE A Thesis by ALICIA IZARRARAZ Submitted to the Graduate College of Texas ARM University in partial fulfillment of the requirement... for the degree of MASTER OF SCIENCE May 1979 Major Subject: Chemical Engineering APPLICATION OF THE THETA METHOD TO DISTILLATION COLUMNS WHERE ONE OR MORE REACTIONS OCCUR PER STAGE A Thesis by ALICIA IZARRARAZ Approved as to style and content by: cubi...

Izarraraz, Alicia

2012-06-07

35

Assessing Safety in Distillation Column Using Dynamic Simulation and Failure Mode and Effect Analysis (FMEA)  

NASA Astrophysics Data System (ADS)

Safety assessment becomes an important activity in chemical industries since the need to comply with general legal requirements in addition to meet safer plant and profit. This paper reviews some most frequently causes of distillation column malfunction. First, analysis of case histories will be discussed for providing guidelines in identifying potential trouble spots in distillation column. A dynamic simulation for operational failure is simulated as the basis for assessing the consequences. A case study will be used from a side stream distillation column to show the implementation of the concept. A framework for assessing safety in the column is proposed using Fault Mode and Effect Analysis (FMEA). Further, trouble-free operation in order to reduce the risk associated with column malfunction is described.

Werner, Suhendra; Fred, Witt; Compart

36

Optimal Allocation of Heat Exchanger Inventory in a Serial Type Diabatic Distillation Column  

E-print Network

Optimal Allocation of Heat Exchanger Inventory in a Serial Type Diabatic Distillation Column Edward the column . We have previously shown (Jimenez et al. 2003) that optimaloperation of serial heat exchangers total heat exchanger area in different trays and calculate the optimal allocation of a given heat

Salamon, Peter

37

Simulation and experimental study of intermediate heat exchange in a sieve tray distillation column  

Microsoft Academic Search

The aim of this study was to combine a simulation study with an experimental in the investigation of intermediate heat exchange as a method to change the distribution of the driving forces in the column where the number of trays is kept constant. It was applied to a pilot plant sieve tray distillation column for a binary separation of ethanol

Ingela Niklasson Björn; Urban Grén; Fredrik Svensson

2002-01-01

38

3D printed porous media columns with fine control of column packing morphology.  

PubMed

In this paper we demonstrate, for the first time, the use of 3D printing (also known as additive manufacturing or rapid prototyping) to create porous media with precisely defined packing morphologies, directly from computer aided design (CAD) models. We used CAD to design perfectly ordered beds with octahedral beads (115 ?m apothem) packed in a simple cubic configuration and monoliths with hexagonal channels (150 ?m apothem) in parallel and herringbone arrangements. The models were then printed by UV curing of acrylonitrile-butadiene-styrene powder layers. Each porous bed was printed at 1.0, 1.5 and 2.0 mL volumes, within a complete column, including internal flow distributors and threaded 10-32 flow connectors. Close replication of CAD models was achieved. The resultant individual octahedral beads were highly uniform in size, with apothems of 113.6±1.9 ?m, while the monolith hexagonal cross-section channels had apothems of 148.2±2.0 ?m. Residence time distribution measurements show that the beds largely behaved as expected from their design void volumes. Radial and fractal flow distributor designs were also tested. The former displayed poor flow distribution in parallel and herringbone pore columns, while the fractal distributors provided uniform flow distribution over the entire cross section. The results show that 3D printing is a feasible method for producing precisely controlled porous media. We expect our approach to revolutionize not only fundamental studies of flow in porous media but methods of chromatography column production. PMID:24529407

Fee, Conan; Nawada, Suhas; Dimartino, Simone

2014-03-14

39

Effect of micropillar density on separation efficiency of semi-packed micro gas chromatographic columns  

Microsoft Academic Search

In this report, the effect on the separation efficiency of the density of square micropillars in semi-packed gas chromatography columns are investigated. Two columns with the same pillar arrangement but different pillar density were experimentally characterized and simulated. The experimental results show that the high pillar density column is 1.2 times superior to the low pillar density column with respect

Sho Nishiyama; Takashi Nakai; Masaki Shuzo; Jean-Jacques Delaunay; Ichiro Yamada

2009-01-01

40

Practical Application of Distillation Column Energy Control Systems  

E-print Network

computer control system on an existing col umn. To be more specific, an ethylene-ethane column will be discussed - ethylene is the light key and ethane is the heavy key. Figure 1 shows a simple diagram for an ethylene column. As shown in Figure 1... is not always at the maximum allowable impurity. In other words, the ethylene column product should not contain the maximum amount of ethane (impurity) for all economic cases. b

Matthews, S. A.

1980-01-01

41

First Commissioning of a Cryogenic Distillation Column for Low Radioactivity Underground Argon  

E-print Network

We report on the performance and commissioning of a cryogenic distillation column for low radioactivity underground argon at Fermi National Accelerator Laboratory. The distillation column is designed to accept a mixture of argon, helium, and nitrogen and return pure argon with a nitrogen contamination less than 10 ppm. In the first commissioning, we were able to run the distillation column in a continuous mode and produce argon that is 99.9% pure. After running in a batch mode, the argon purity was increased to 99.95%, with 500 ppm of nitrogen remaining. The efficiency of collecting the argon from the gas mixture was between 70% and 81%, at an argon production rate of 0.84-0.98 kg/day.

H. O. Back; T. Alexander; A. Alton; C. Condon; E. de Haas; C. Galbiati; A. Goretti; T. Hohmann; An. Ianni; C. Kendziora; B. Loer; D. Montanari; P. Mosteiro; S. Pordes

2012-05-01

42

A nonlinear profile observer using tray temperatures for high-purity binary distillation column control  

Microsoft Academic Search

A new, concise nonlinear profile position observer using tray temperatures instead of tray compositions is proposed. Composition measurement has been one of the major difficulties associated with the composition control of distillation columns because the on-line analyzers still suffer from large measurement delays, high investment\\/maintenance costs and low reliability. One of common alternatives to the analyzers is to use the

Joonho Shin; Hodong Seo; Myungwan Han

2000-01-01

43

Fuzzy supervisory PI control of a binary distillation column via distributed control systems  

Microsoft Academic Search

In this paper, the fuzzy supervisory PI control is implemented via distributed control systems (DCS) to control a binary distillation column. The fuzzy c-mean clustering is used to identify the membership functions and fuzzy rules are determined using fuzzy gain scheduling technique. Thus, the need of heuristic method for designing fuzzy membership functions and rules from expert knowledge is omitted.

Poramade Cheingjong; Suvalai Pratishthananda

2008-01-01

44

Development of a fritless packed column for capillary electrochromatography-mass spectrometry.  

PubMed

A novel procedure was developed for the fabrication of a fritless packed column for the coupling of capillary electrochromatography (CEC) to mass spectrometry (MS). The process involved the formation of internal tapers on two separate columns. Once the internal tapers are formed and the columns are packed, the untapered ends of each column were joined together by a commercially available connector. Several advantages of the fritless columns are described. First, the design used here eventually eliminates the need for any frits thus reducing the possibility of bubble formation seen with fritted packed columns. In addition, this is the first report in which the internal tapers are formed at both the inlet and outlet column ends making the fritless CEC-MS column more robust compared to only one report with externally tapered counterparts. Second, a comparison of internally tapered single frit packed CEC-MS (previously developed in our laboratory) column versus fritless CEC-MS column reported here shows that the latter provides better efficiency, suggesting no dead volume with equally good sensitivity and chiral resolution of (±)-aminoglutethimide. The fritless column procedure is universal and was used to prepare a series of columns with a variety of commercially available packing material (mixed mode strong cation exchange, SCX; mixed mode strong anion exchange, SAX; C-18) for the separation and MS detection of short chain non-chromophoric polar amines, long chain nonchromophic anionic surfactant as well as oligomers of non-chromophoric non-ionic surfactants, respectively. The fritless columns showed good intra-day repeatability and inter-day reproducibility of retention times, chiral and achiral resolutions and peak areas. Very satisfactory column-to-column and operator-to-operator reproducibility was demonstrated. PMID:22035695

Bragg, William; Shamsi, Shahab A

2011-12-01

45

Development of a Fritless Packed Column for Capillary Electrochromatography-Mass Spectrometry  

PubMed Central

A novel procedure was developed for the fabrication of a fritless packed column for the coupling of capillary electrochromatography (CEC) to mass spectrometry (MS). The process involved the formation of internal tapers on two separate columns. Once the internal tapers are formed and the columns are packed, the untapered ends of each column were joined together by a commercially available connector. Several advantages of the fritless columns are described. First, the design used here eventually eliminates the need for any frits thus reducing the possibility of bubble formation seen with fritted packed columns. In addition, this is the first report in which the internal tapers are formed at both the inlet and outlet column ends making the fritless CEC-MS column more robust compared to only one report with externally tapered counterparts. Second, a comparison of internally tapered single frit packed CEC-MS (previously developed in our laboratory) column versus fritless CEC-MS column reported here shows that the latter provides better efficiency, suggesting no dead volume with equally good sensitivity and chiral resolution of (±)-aminoglutethimide. The fritless column procedure is universal and was used to prepare a series of columns with a variety of commercially available packing material (mixed mode strong cation exchange, SCX; mixed mode strong anion exchange, SAX; C-18) for the separation and MS detection of short chain non-chromophoric polar amines, long chain nonchromophic anionic surfactant as well as oligomers of non-chromophoric non-ionic surfactants, respectively. The fritless columns showed good intra-day repeatibility and inter-day reproducibility of retention times, chiral and achiral resolutions and peak areas. Very satisfactory column-to-column and operator-to-operator reproducibility was demonstrated. PMID:22035695

Bragg, William; Shamsi, Shahab A.

2011-01-01

46

Modified method to improve the design of Petlyuk distillation columns  

PubMed Central

Background A response surface analysis was performed to study the effect of the composition and feeding thermal conditions of ternary mixtures on the number of theoretical stages and the energy consumption of Petlyuk columns. A modification of the pre-design algorithm was necessary for this purpose. Results The modified algorithm provided feasible results in 100% of the studied cases, compared with only 8.89% for the current algorithm. The proposed algorithm allowed us to attain the desired separations, despite the type of mixture and the operating conditions in the feed stream, something that was not possible with the traditional pre-design method. The results showed that the type of mixture had great influence on the number of stages and on energy consumption. A higher number of stages and a lower consumption of energy were attained with mixtures rich in the light component, while higher energy consumption occurred when the mixture was rich in the heavy component. Conclusions The proposed strategy expands the search of an optimal design of Petlyuk columns within a feasible region, which allow us to find a feasible design that meets output specifications and low thermal loads. PMID:25061476

2014-01-01

47

Nonlinear model-based control algorithm for a distillation column using software sensor.  

PubMed

This paper presents the design of model-based globally linearizing control (GLC) structure for a distillation process within the differential geometric framework. The model of a nonideal binary distillation column, whose characteristics were highly nonlinear and strongly interactive, is used as a real process. The classical GLC law is comprised of a transformer (input-output linearizing state feedback), a nonlinear state observer, and an external PI controller. The tray temperature based short-cut observer (TTBSCO) has been used as a state estimator within the control structure, in which all tray temperatures were considered to be measured. Accordingly, the liquid phase composition of each tray was calculated online using the derived temperature-composition correlation. In the simulation experiment, the proposed GLC coupled with TTBSCO (GLC-TTBSCO) outperformed a conventional PI controller based on servo performances with and without measurement noise as well as on regulatory behaviors. In the subsequent part, the GLC law has been synthesized in conjunction with tray temperature based reduced-order observer (GLC-TTBROO) where the distillate and bottom compositions of the distillation process have been inferred from top and bottom product temperatures respectively, which were measured online. Finally, the comparative performance of the GLC-TTBSCO and the GLC-TTBROO has been addressed under parametric uncertainty and the GLC-TTBSCO algorithm provided slightly better performance than the GLC-TTBROO. The resulting control laws are rather general and can be easily adopted for other binary distillation columns. PMID:15868863

Jana, Amiya Kumar; Samanta, Amar Nath; Ganguly, Saibal

2005-04-01

48

Laboratory studies of the behavior of undissolved solids in both pulsed and packed column extraction systems  

SciTech Connect

A substantial fraction of the finely divided undissolved solid material found in nuclear fuel reprocessing dissolver-product solutions is hydrophobic and tends to seek'' any organic-aqueous interface existing within countercurrent liquid-liquid extraction systems. While passing through pulsed-type columns this material is swept out of the aqueous phase by the combined surface area of the tiny bubbles of dispersed phase. Because these bubbles have a net velocity towards the end of the column where the nominal interface is located, the solids are swept in that direction too. These solids tend to gather in a three-phase crud'' layer at the nominal interface point. At equilibrium, about the same amount breaks off from the crud layer and escapes into the liquid exiting from that end of the column as enters it from the other side. If large enough, the crud layer can even interfere with interface detection and control equipment. In packed-column extraction systems, an additional problem is that feed solids can accumulate within the packing material to the point that the column floods'' or even totally plugs. The keys to preventing solids-related problems is the correct choice of interface level, and with packed columns, the addition of a pulsing leg'' at the bottom of the column. Pulsing packed column systems not only prevents solids from settling onto packing material but it also increses the number of theoretical stages available for extraction. 3 figs., 2 tabs.

Siemer, D.D.

1989-04-18

49

Laboratory studies of the behavior of undissolved solids in both pulsed and packed column extraction systems  

SciTech Connect

A substantial fraction of the finely divided undissolved solid material found in nuclear fuel reprocessing dissolver-product solutions is hydrophobic and tends to ``seek`` any organic-aqueous interface existing within countercurrent liquid-liquid extraction systems. While passing through pulsed-type columns this material is swept out of the aqueous phase by the combined surface area of the tiny bubbles of dispersed phase. Because these bubbles have a net velocity towards the end of the column where the nominal interface is located, the solids are swept in that direction too. These solids tend to gather in a three-phase ``crud`` layer at the nominal interface point. At equilibrium, about the same amount breaks off from the crud layer and escapes into the liquid exiting from that end of the column as enters it from the other side. If large enough, the crud layer can even interfere with interface detection and control equipment. In packed-column extraction systems, an additional problem is that feed solids can accumulate within the packing material to the point that the column `` floods`` or even totally plugs. The keys to preventing solids-related problems is the correct choice of interface level, and with packed columns, the addition of a ``pulsing leg`` at the bottom of the column. Pulsing packed column systems not only prevents solids from settling onto packing material but it also increses the number of theoretical stages available for extraction. 3 figs., 2 tabs.

Siemer, D.D.

1989-04-18

50

Estimating vent emissions from a distillation column: An alternative to stack testing  

SciTech Connect

This technical paper points out the cost-effectiveness and data manageability of material balance over the epidemic use of stack testing in the chemical industry. An example is drawn from a Title V emissions inventory prepared for an international manufacturer of pharmaceuticals and fuel additives. This example case focuses on the use of mass balance to estimate noncondensibles generated by a typical large-scale distillation column. Distillation fundamentals are reviewed, including discussion of relative volatility, x-y and McCabe-Thiele diagrams, and basic sieve tray mechanics. A seemingly complex set of energy and material balance equations is simplified by the application of constant molar overflow. The example case concludes with a calculation of column noncondensibles, and the paper closes with a review of the material balance approach, including its strengths, limitations, and applicability to other unit operations.

Dickerson, D.L. Jr. [ERM-Southeast, Charleston, SC (United States)

1996-12-31

51

Solution of Multicomponent distillation problems for conventional and complex columns at unsteady state operation  

E-print Network

-METHOD OF CONVERGENCE Complex Columns . Other Specifications for Holdups 13 15 IV. MODIFIED IMPLICIT METHOD 19 Use of the Modified Implicit Method in the Solution of Unsteady State Distillation Problems. Solution of Enthalpy Balances by Use... for Example 1 44 Results Obtained for Example 2 by Use of the Analytical Solution and Numerical Methods at Relatively Small Intervals 45 Results Obtained for Example 2 with X = 0. 1 and x = 0, 9 by Use of Analytical Solution and 0 Numerical Methods...

Pendon, Gregorio Parrenas

2012-06-07

52

Towards further internal heat integration in design of reactive distillation columns—part I: The design principle  

Microsoft Academic Search

The thermodynamic efficiency of a reactive distillation column involving reactions with a highly thermal effect could sometimes be improved substantially through seeking further internal heat integration between the reaction operation and separation operation. Prudent arrangement of the reactive section and deliberate determination of feed location are the two effective methods that can complement internal heat integration within a reactive distillation

Kejin Huang; Koichi Iwakabe; Masaru Nakaiwa; Atsushi Tsutsumi

2005-01-01

53

Mobility of spiromesifen in packed soil columns under laboratory conditions.  

PubMed

On percolating water equivalent to 1,156 mm of rainfall, spiromesifen formulation did not leach out of 25-cm long columns, and 62.7 % of this was recovered in 5-10-cm soil depth. In columns treated with the analytical grade, 52.40 % of the recovered spiromesifen was confined to 0-5-cm soil depth, with 0.04 % in leachate fraction, suggesting high adsorption in soil. Results revealed that percolating 400 mL of water, residues of enol metabolite of spiromesifen was detected up to 20-25-cm soil layer, with 23.50 % residues of spiromesifen in this layer and 1.73 % in the leachate fraction indicating that metabolite is more mobile as compared to the parent compound. Results suggested a significant reduction in leaching losses of enol metabolite in amended soil columns with 5 % nano clay, farmyard manure (FYM), and vermicompost. No enol spiromesifen was recovered in the leachate in columns amended with nano clay, vermicompost, and FYM; however, 85.30, 70.5, and 65.40 %, respectively, was recovered from 0-5 cm-soil depth of column after percolating water equivalent to 1,156 mm of rainfall. Spiromesifen formulation is less mobile in sandy loam soil than analytical grade spiromesifen. The metabolite, enol spiromesifen, is relatively more mobile than the parent compound and may leach into groundwater. The study suggested that amendments were very effective in reducing the downward mobility of enol metabolite in soil column. Further, it resulted in greater retention of enol metabolite in the amendment application zone. PMID:25060860

Mate, Ch Jamkhokai; Mukherjee, Irani; Das, Shaon Kumar

2014-11-01

54

Dynamic catalytic distillation: Advanced simulation and experimental validation  

Microsoft Academic Search

Reactive distillation offers a number of potential advantages, so that many traditional operations are currently being investigated in order to discover further applications of this technology. Increasingly, it is performed in columns with catalytic packings that combine the advantages of normal structured packings and heterogeneous catalysts. Analysis of reactive distillation is difficult due to strong physico-chemical interactions, and it is

L. U. Kreul; A. Górak; C. Dittrich; P. I. Barton

1998-01-01

55

Exchange front stability in packed-column chromatography  

SciTech Connect

Exchange front deformation in gas-phase chromatography may sometimes impair column performance. Such deformation can arise from column heterogeneities or from the unstable growth of small disturbances inherently present in the flow field. Here we examine the fundamental stability of a planar traveling exchange front subject to a small sinusoidal perturbation in the front position. The analysis includes the disparity between fluid and front velocities characteristic of exchange chromatography, as well as the distinction between fluid velocities ahead of and behind the front resulting from the net sorption of gases. Fluid compressibility is also considered. Disturbance growth rates are computed as a function of the wavelength, fluid viscosity ratio, and normalized front and fluid velocities over a wide range of each parameter. We find that growth rates increase with increasing viscosity ratio, decreasing wavelength, and increasing normalized front and fluid velocities. Conditions of neutral stability are also determined and indicate that fluid compressibility and net desorption tend to destabilize the exchange front. Sample calculations are presented for the problem of hydrogen isotope exchange in a column of palladium powder.

Griffiths, S.K. [Sandia National Labs., Livermore, CA (United States); Nilson, R.H. [S-Cubed, La Jolla, CA (United States)

1993-04-01

56

Observation of enhanced heat dissipation in columns packed with superficially porous particles.  

PubMed

At high flow rates and pressures, columns packed with sub-2 ?m particles suffer from efficiency losses due to frictional heating. The thermal environment of the column (insulated or isothermal) can decrease or magnify these losses. While a number of studies have been conducted demonstrating the improved performance (partially due to the benefits of enhanced thermal conductivity) of columns packed with superficially porous particles, none have made a comparison between sub-2 ?m fully and superficially porous particles in an isothermal environment where radial thermal gradients are maximized and thermal broadening is amplified. Here we show that when such columns are characterized in a recirculating water jacket (providing an isothermal environment), efficiency loss and changes in retention and mobile phase temperature are reduced for sub-2 ?m superficially porous particles compared to sub-2 ?m fully porous particles. PMID:25456605

Grinias, James P; Keil, Dayley S; Jorgenson, James W

2014-12-01

57

Properties of cattle bone powder-coated composite particles as high-performance and open column liquid chromatographic column packings.  

PubMed

Cattle bone powder (CBP) from natural resources was employed as a protein adsorbent instead of chemically synthesized hydroxyapatite (HA). Though a small amount of impurities was detected, CBP possessed a crystallinity similar to HA. Using CBP/40PE prepared from CBP and polyethylene beads (40 microns) by dry impact blending as an HPLC column packing, considerable correlation was observed between the elution concentrations of proteins and their pI. Such behavior was caused by the relatively large adsorption capacity for basic proteins. CBP/40PE could completely separate gamma-globulin from BSA also as an open column chromatographic support, under relatively low concentration. PMID:9697314

Honda, F; Honda, H; Koishi, M; Matsuno, T

1998-07-10

58

A study of polyethoxylated alkylphenols by packed column supercritical fluid chromatography.  

PubMed

Alkylphenol polyethoxylates (APEs) are a widely used group of nonionic surfactants in commercial production. Characterization of the composition of APE mixtures can be exploited for the determination of their most effective uses. In this study sample mixtures contain nonylphenol polyethoxylates and octylphenol polyethoxylates. The separation of individual alkylphenols by ethoxylate units is performed by supercritical fluid chromatography (SFC)-UV as well as normal-phase high-performance liquid chromatographic (HPLC)-UV employing packed columns. The stationary phase and column length are varied in the SFC setup to produce the most favorable separation conditions. Additionally, combinations of packed columns of different stationary phases are tested. The combination of a diol and a cyano column is found to produce optimal results. An advantage of using packed columns instead of capillary columns is the ability to inject large amounts of sample and thus collect eluted fractions. In this regard, fractions from SFC runs are collected and analyzed by flow injection analysis-electrospray ionization-mass spectroscopy in order to positively identify the composition of the fractions. In comparing the separation of APE mixtures by SFC and HPLC, it is found that SFC provides shorter retention times with similar resolution. In addition, less solvent waste is produced using SFC. PMID:11881706

Hoffman, Brian J; Taylor, Larry T

2002-02-01

59

Distillation  

NSDL National Science Digital Library

Science in its earliest beginnings consisted of a practice called alchemy. Alchemy includes the study of chemistry, biology, astronomy, spirituality, physics, and art. Distillation or experiments in purification of substances may have been a part of the practice of alchemy.

N/A N/A (None;)

2005-12-24

60

New Generation of Chromatographic Packings and Columns for Determination of Biologically Active Compounds  

Microsoft Academic Search

Analysis of biologically active substances is particularly important in the pharmaceutical and biomedical area. For separation of polar compounds or complex mixtures by normal (NP) or reversed phase liquid chromatography (RP-HPLC) and\\/or electromigration techniques, it is necessary to apply a new generation of packings and columns with strictly defined properties. It is connected to the definition of chromatographic behavior and

Bogus?aw Buszewski; Sylwia Kowalska; Katarzyna Krupczy?ska

2005-01-01

61

Final Report - Advanced Hydraulic and Mass Transfer Models for Distillation Column Optimization and Design  

SciTech Connect

The project successfully developed a computational fluid dynamics (CFD) based simulation of the hydrodynamics of flow in a commercial structured packing element. This result fulfilled the prime objective of the research program. The simulation utilized commercial CFD code marketed by Fluent Inc. in combination with a novel graphical interface developed by Oak Ridge National Lab. The end product will allow the design of next generation column internals without the need for extensive experimental validation and will expand the fundamental understanding of the vapor-liquid contacting process.

Eldridge, Robert, B.

2005-10-13

62

Continuous aqueous two-phase extraction of human antibodies using a packed column.  

PubMed

The performance of a pilot scale packed differential contactor was evaluated for the continuous counter-current aqueous two-phase extraction (ATPE) of human immunoglobulin G (IgG) from a Chinese hamster ovary (CHO) cells supernatant (CS) enriched with pure protein. Preliminary studies have been firstly performed in order to select the dispersed phase (phosphate-rich or polyethylene glycol 3350 Da (PEG)-rich phase) and the column packing material. The PEG-rich phase has been selected as the dispersed phase and the stainless steel as the preferred material for the column packing bed since it was not wetted preferentially by the selected dispersed phase. Hydrodynamic studies have been also performed, and the experimental results were successfully adjusted to the Richardson-Zaki and Mísek equations, typically used for the conventional organic-aqueous two-phase systems. An experimental set-up combining the packed column with a pump mixer-settler stage showed to have the best performance and to be advantageous when compared to the IgG batch extraction. An IgG recovery yield of 85% could be obtained with about 50% of total contaminants and more than 85% of contaminant proteins removal. Mass transfer studies have revealed that the mass transfer was controlled by the PEG-rich phase. A higher efficiency could be obtained when using an extra pump mixer-settler stage and higher flow rates. PMID:22173005

Rosa, P A J; Azevedo, A M; Sommerfeld, S; Bäcker, W; Aires-Barros, M R

2012-01-01

63

?iocolloid and colloid transport through water-saturated columns packed with glass beads: Effect of gravity  

NASA Astrophysics Data System (ADS)

The role of gravitational force on biocolloid and colloid transport in water-saturated columns packed with glass beads was investigated. Transport experiments were performed with biocolloids (bacteriophages: ??174, MS2) and colloids (clays: kaolinite KGa-1b, montmorillonite STx-1b). The packed columns were placed in various orientations (horizontal, vertical, and diagonal) and a steady flow rate of Q=1.5 mL/min was applied in both up-flow and down-flow modes. All experiments were conducted under electrostatically unfavorable conditions. The experimental data were fitted with a newly developed, analytical, one dimensional, colloid transport model, accounting for gravity effects. The results revealed that flow direction has a significant influence on particle deposition. The rate of particle deposition was shown to be greater for up-flow than for down-flow direction, suggesting that gravity was a significant driving force for biocolloid and colloid deposition. Schematic illustration of a packed column with up-flow velocity having orientation (-i) with respect to gravity. The gravity vector components are: g(i)= g(-z) sin? i, and g(-j)= -g(-z) cos? j. Experimental setup showing the various column arrangements: (a) horizontal, (b) diagonal, and (c) vertical.

Chrysikopoulos, C. V.; Syngouna, V. I.

2013-12-01

64

Comparison of different types of outlet frits in slurry-packed capillary columns.  

PubMed

Fused-silica capillary columns for high-performance liquid chromatography with 320 and 250 ?m inner diameter were prepared by slurry packing with 5 and 3 ?m Nucleosil C18 stationary phase. Different types of mechanical and monolithic outlet frits were used and their influence on the resulting column performance was evaluated. Columns with quartz wool exhibited symmetrical peaks and low theoretical plate height, and the preparation time was short. The performance of monolithic frits varied based on type of monolith, length of the frit, and silanization procedure. The best frit performed similarly to the quartz wool ones, but the preparation took several hours. Their main advantage lies in the possibility of on-column detection, because the detection window can be burnt immediately behind the frit. PMID:24947807

Franc, Martin; Sobotníková, Jana; Coufal, Pavel; Bosáková, Zuzana

2014-09-01

65

Adsorption of polypropylene from dilute solutions on a zeolite column packing.  

PubMed

Faujasite type zeolite CBV-780 was tested as adsorbent for isotactic polypropylene by liquid chromatography. When cyclohexane, cyclohexanol, n-decanol, n-dodecanol, diphenylmethane, or methylcyclohexane was used as mobile phase, polypropylene was fully or partially retained within the column packing. This is the first series of sorbent-solvent systems to show a pronounced retention of isotactic polypropylene. According to the hydrodynamic volumes of polypropylene in solution, macromolecules of polypropylene should be fully excluded from the pore volume of the sorbent. Sizes of polypropylene macromolecules in linear conformations, however, correlate with the pore size of the column packing used. It is presumed that the polypropylene chains partially penetrate into the pores and are retained due to the high adsorption potential in the narrow pores. PMID:15688632

Macko, Tibor; Pasch, Harald; Denayer, Joeri F

2005-01-01

66

Biosorption of Cu in a packed bed column by almond shell: optimization of process variables  

Microsoft Academic Search

This paper presents the ability of a low-cost biosorbent, almond shell, to remove Cu(II) ions from aqueous solution. Biosorption capacity of almond shell to removal Cu(II) was studied in a packed bed column. The effect of various parameters, flow rate, initial copper concentration, and mass of biosorbent, was analyzed. A 2 factorial experiment design was carried out to optimize some

Mónica Calero de Hoces; Gabriel Blázquez García; Alicia Ronda Gálvez; Ana Estefanía Álvarez; María Ángeles Martín-Lara

2012-01-01

67

Systematic comparison of a new generation of columns packed with sub-2 ?m superficially porous particles.  

PubMed

The aim of this study was to evaluate the possibilities/limitations of recent RP-LC columns packed with 1.6 ?m superficially porous particles (Waters Cortecs) and to compare its potential to other existing sub-2 ?m core-shell packings. The kinetic performance of Kinetex 1.3 ?m, Kinetex 1.7 ?m and Cortecs 1.6 ?m stationary phases was assessed. It was found that the Kinetex 1.3 ?m phase outperforms its counterparts for ultra-fast separations. Conversely, the Cortecs 1.6 ?m packing seemed to be the best stationary phase for assays with longer analysis time in isocratic and gradient modes, considering small molecules and peptides as test probes. This exceptional behaviour was attributed to its favourable permeability and somewhat higher mechanical stability (?Pmax of 1200 bar). The loading capacity of these three columns was also investigated with basic and neutral drugs analysed under acidic conditions. It appears that the loading capacities of Cortecs 1.6 ?m and Kinetex 1.7 ?m were very close, while it was reduced by 2-7-fold on the Kinetex 1.3 ?m packing. However, this observation is dependent on the nature of the compound and certainly also on mobile phase conditions. PMID:24302641

Bobály, Balázs; Guillarme, Davy; Fekete, Szabolcs

2014-02-01

68

Column performance of granular activated carbon packed bed for Pb(II) removal.  

PubMed

The excessive release of lead from lead acid batteries, smelting plant into the environment is a major concern worldwide. Adsorption process is among the most effective techniques for lead removal from wastewater and activated carbon has been widely used as an adsorbent. In this paper an attempt has been made to investigate the adsorption behaviour of Pb(II) from aqueous systems onto granular activated carbon using the batch mode and continuous mode in a packed bed column with more successive service and regeneration. The experiments were performed at constant temperature and dimensions of column and packed bed of granular activated carbon with variation of flows through the bed and concentrations of lead solutions. Breakthrough points were found out for the adsorption of lead on the adsorbent using continuous-flow column operation by varying different operating parameters like hydraulic loading rate from 4 to 16 m(3)/h m(2) and feed concentrates from 20 to 60 mg/l. Granular activated carbon column regeneration using 0.5 M concentration of HNO(3) has been investigated. Results indicate encouraging performance towards removal of Pb(II). PMID:18249492

Dwivedi, Chandra P; Sahu, J N; Mohanty, C R; Mohan, B Raj; Meikap, B C

2008-08-15

69

Continuous metal removal from solution and industrial effluents using Spirogyra biomass-packed column reactor.  

PubMed

The granules of Spirogyra neglecta biomass, diameter 0.2-0.5mm, were successfully prepared by boiling it in urea-formaldehyde mixture. Metal sorption performance of the column packed with Spirogyra granules was assessed under variable operating conditions, such as, different influent metal concentrations, bed heights and flow rates. These conditions greatly influenced the breakthrough time and volume, saturation time and volume, and the ability of the column to attain saturation after reaching the breakthrough. The experimental breakthrough curves obtained under varying experimental conditions were modeled using Bohart-Adams, Wolborska, Thomas, Yoon-Nelson and modified dose-response models. The first two models were valid only in representing the initial part of the breakthrough curves; however, the other three models were good in representing the entire breakthrough curve. The granule-packed column could be successfully used up to 6 and 9 cycles of sorption and desorption for the removal of Cu(II) and Pb(II), respectively. The column could efficiently remove different metals from real industrial effluents, and hence the test biomass (Spirogyra granules) is a good candidate for commercial application. PMID:22169159

Singh, Alpana; Kumar, Dhananjay; Gaur, J P

2012-03-01

70

PRECISION AND ACCURACY IN THE DETERMINATION OF ORGANICS IN WATER BY FUSED SILICA CAPILLARY COLUMN GAS CHROMOTOGRAPHY/MASS SPECTROMETRY AND PACKED COLUMN GAS CHROMATOGRAPHY/MASS SPECTROMETRY  

EPA Science Inventory

Two general methods for the identification and measurement of organic compounds in water are compared. One method employs packed column chromatography and the other fused silica capillary column chromatography. The two gas chromatography/mass spectrometry (GC/MS) methods use diff...

71

Simulation of hydrogen sulphide absorption in alkaline solution using a packed column.  

PubMed

In this work, a simulation tool was developed for hydrogen sulphide (H2S) removal in an alkaline solution in packed columns working at countercurrent. Modelling takes into account the mass-transfer enhancement due to the reversible reactions between H2S and the alkaline species ([Formula: see text], [Formula: see text] and HO(-)) in the liquid film. Many parameters can be controlled by the user such as the gas and liquid inlet H2S concentrations, the gas and liquid flow rates, the scrubbing liquid pH, the desired H2S removal efficiency, the temperature, the alkalinity, etc. Since the influence of the hydrodynamic and mass-transfer performances in a packed column is well known, the numerical resolutions performed were dedicated to the study of the influence of the chemical conditions (through the pH and the alkalinity), the temperature and the liquid-to-gas mass flow rate ratio (L/G). A packed column of 3 m equipped with a given random packing material working at countercurrent and steady state has been modelled. The results show that the H2S removal efficiency increases with the L/G, the pH, the alkalinity and more surprisingly with the temperature. Alkalinity has a very significant effect on the removal efficiency through the mass-transfer enhancement and buffering effect, which limits pH decreasing due to H2S absorption. This numerical resolution provides a tool for designers and researchers involved in H2S treatment to understand deeper the process and optimize their processes. PMID:25244138

Azizi, Mohamed; Biard, Pierre-François; Couvert, Annabelle; Ben Amor, Mohamed

2014-12-01

72

Modeling of chromium (VI) biosorption by immobilized Spirulina platensis in packed column.  

PubMed

This study describes biosorption of chromium (VI) by immobilized Spirulina platensis, in calcium alginate beads. Three aspects viz. optimization of bead parameters, equilibrium conditions and packed column operation were studied and subsequently modeled. Under optimized bead diameter (2.6mm), calcium alginate concentration (2%, w/v) and biomass loading (2.6%, w/v) maximum biosorption was achieved. 140 g l(-1) loading of optimized beads resulted in 99% adsorption of chromium (VI) ions from an aqueous solution containing 100 mg l(-1) of chromium (VI). The quantitative chromium (VI) uptake was effectively described by Freundlich adsorption isotherm. The immobilized S. platensis beads were further used in a packed bed column wherein the effects of bed height, feed flow rate, inlet chromium (VI) ion concentration were studied by assessing breakthrough time. The performance data were tested for various models fitting in order to predict scale up-design parameters such as breakthrough time and column height. Results were encouraging. PMID:19493617

Gokhale, S V; Jyoti, K K; Lele, S S

2009-10-30

73

Packing of large-scale chromatography columns with irregularly shaped glass based resins using a stop-flow method  

PubMed Central

Rigid chromatography resins, such as controlled pore glass based adsorbents, offer the advantage of high permeability and a linear pressure-flow relationship irrespective of column diameter which improves process time and maximizes productivity. However, the rigidity and irregularly shaped nature of these resins often present challenges in achieving consistent and uniform packed beds as formation of bridges between resin particles can hinder bed consolidation. The standard flow-pack method when applied to irregularly shaped particles does not yield well-consolidated packed beds, resulting in formation of a head space and increased band broadening during operation. Vibration packing methods requiring the use of pneumatically driven vibrators are recommended to achieve full packed bed consolidation but limitations in manufacturing facilities and equipment may prevent the implementation of such devices. The stop-flow packing method was developed as an improvement over the flow-pack method to overcome these limitations and to improve bed consolidation without the use of vibrating devices. Transition analysis of large-scale columns packed using the stop-flow method over multiple cycles has shown a two- to three-fold reduction of change in bed integrity values as compared to a flow-packed bed demonstrating an improvement in packed bed stability in terms of the height equivalent to a theoretical plate (HETP) and peak asymmetry (As). PMID:25080096

Siu, Sun Chau; Chia, Celeste; Mok, Yanglin; Pattnaik, Priyabrata

2014-01-01

74

Effects of reflux ratio and feed conditions for the purification of bioethanol in a continuous distillation column  

NASA Astrophysics Data System (ADS)

Continuous distillation column was used for the purification of bioethanol from fermentation of molasses using Saccharomyces cerevisia. Bioethanol produced was at 8.32% (v/v) level. The efficiency of continuous distillation process was evaluated based on reflux ratio, and feed condition. The lab results were validated using COFE simulation Software. The analyses showed that both reflux ratio and feed condition had significant effects on the distillation process. Stages increased from 1.79 to 2.26 as the reflux ratio was decreased from 90% to 45% and the saturated feed produced lower mole fraction of desired product. We concluded that the lower reflux ratio with cold feed condition was suitable for higher mole fraction of top product.

Dasan, Y. K.; Abdullah, M. A.; Bhat, A. H.

2014-10-01

75

Micro-columns packed with Chlorella vulgaris immobilised on silica gel for mercury speciation.  

PubMed

A method has been developed for mercury speciation in water by using columns packed with Chlorella vulgaris immobilised on silica gel. The method involves the retention of CH(3)Hg(+) and Hg(2+) in micro-columns prepared by packing immobilised algae in polypropylene tubes, followed by selective and sequential elution with 0.03 and 1.5M HCl for CH(3)Hg(+) and Hg(2+), respectively. The adsorption capacity of the micro-algae for Hg(2+) and CH(3)Hg(+) has been evaluated using free and immobilised C. vulgaris. The efficiency uptake for both species at pH 3 was higher than 97%. Studies were carried out on the effect of retention and elution conditions for both species. Furthermore, the stability of mercury species retained on algae-silica gel micro-columns and lifetime of the columns were also investigated. Hg(2+) showed a higher stability than CH(3)Hg(+) at 0 degrees C (21 and 3 days, respectively) and a better lifetime than for the organic species. The developed method was applied to the analysis of spiked tap, sea and wastewater samples. Recovery studies on tap and filtered seawater provided results between 96+/-3 and 106+/-2 for Hg(2+) and from 98+/-5 to 107+/-5 for CH(3)Hg(+), for samples spiked with single species. For samples spiked with both CH(3)Hg(+) and Hg(2+), the average recoveries varied from 96+/-5 to 99+/-3 and from 103+/-6 to 115+/-5 for Hg(2+) and CH(3)Hg(+), respectively. However, the percentages of retention and elution on wastewater and unfiltered seawater were only adequate for the inorganic species. PMID:18970490

Tajes-Martínez, P; Beceiro-González, E; Muniategui-Lorenzo, S; Prada-Rodríguez, D

2006-02-28

76

Effects of Gravity on Cocurrent Two-Phase Gas-Liquid Flows Through Packed Columns  

NASA Technical Reports Server (NTRS)

This work presents the experimental results of research on the influence of gravity on flow pattern transitions, pressure drop and flow characteristics for cocurrent gas-liquid two-phase flow through packed columns. The flow pattern transition data indicates that the pulse flow regime exists over a wider range of gas and liquid flow rates under reduced gravity conditions compared to normal gravity cocurrent down-flow. This is illustrated by comparing the flow regime transitions found in reduced gravity with the transitions predicted by Talmor. Next, the effect of gravity on the total pressure drop in a packed column is shown to depend on the flow regime. The difference is roughly equivalent to the liquid static head for bubbly flow but begins to decrease at the onset of pulse flow. As the spray flow regime is approached by increasing the gas to liquid ratio, the effect of gravity on pressure drop becomes negligible. Finally, gravity tends to suppress the amplitude of each pressure pulse. An example of this phenomenon is presented.

Motil, Brian J.; Balakotaiah, Vemuri; Kamotani, Yasuhiro

2001-01-01

77

COED Transactions, Vol. X, No. 5, May 1978. STAGEF, A Program to Compute the Internal Variables of an Operating Distillation Column.  

ERIC Educational Resources Information Center

A digital computer program, STAGEF, designed for use with the distillation experiments in a typical undergraduate Chemical Engineering laboratory in Unit Operations is explained. The program enables the student to determine the rate of liquid overflow and vapor boil-up which leaves each tray within the distillation column. The student may also…

Marcovitz, Alan B., Ed.

78

Kinetic evaluation of new generation of column packed with 1.3 ?m core-shell particles.  

PubMed

The goal of this study was to critically evaluate a new generation of columns packed with 1.3 ?m core-shell particles. The practical possibilities and limitations of this column technology were assessed and performance was compared with other reference columns packed with 1.7, 2.6 and 5 ?m core-shell particles. The column efficiency achieved with 1.3 ?m core-shell particles was indeed impressive, Hmin value of only 1.95 ?m was achieved, this would correspond to an efficiency of more than 500,000 plates/m. The separation impedance of this column was particularly low, Emin=2000, mostly due to a reduced plate height, h of 1.50. Comparing the kinetic performance of 1.3 ?m core-shell particles to that of other particle dimensions tested in this study revealed that the 1.3 ?m material could provide systematically the shortest analysis time in a range of below 30,000 theoretical plates (N<30,000).Despite its excellent chromatographic performance, it was evident that this column suffers from the limitations of current instrumentation in terms of upper pressure limit and extra-column band broadening: (1) even at 1,200 bar, it was not possible to reach an optimal linear velocity showing minimal plate height value, due to the low permeability of this column (Kv=1.7×10(-11)cm(2)), and (2) for these short narrow bore columns packed with 1.3 ?m core shell particles, which is mandatory for performing fast-analysis and preventing the influence of frictional heat on column performance in UHPLC, it was observed that the extra-column band broadening could have a major impact on the apparent kinetic performance. In the present work, significant plate count loss was noticed for retention factors of less than 5, even with the best system on the market (?(2)ec=2 ?L(2)). PMID:23953620

Fekete, Szabolcs; Guillarme, Davy

2013-09-20

79

Permeability Change of Crystalline Silicate Mineral-Packed Bed Column by Highly Alkaline Plume  

SciTech Connect

For the construction of the geological disposal system, the use of the cementitious material may change the permeability of the natural barrier around the repository. Cementitious materials may alter the pH of ground water to highly alkaline. Also, the potential permeability change of the natural barrier is one of the notable factors for performance assessments of geological disposal systems. In the high pH region, the solubility of silica is very high compared to that in the natural pH (around 8). Therefore, highly alkaline groundwater would dissolve and alter a part of rock surface. Usui et al. (2005) reported that the change of mineral pore structure due to chemical reaction is the key factor to consider the change of the permeability [5-6]. Moreover, such a change of the pore structure was considered to be the result of the spatial heterogeneity of chemical composition. Since such spatial heterogeneity exists also in the sedimentary rocks consisting of crystalline minerals such as quartz and feldspar, we need to examine natural rock, in order to obtain more reliable understanding about the change of permeability induced by highly alkaline groundwater (plume). In this study, silica sand as crystalline mineral was packed in the column, and the effect of dissolution induced by the highly alkaline plume on the permeability-change was examined. The silica sand particles mainly consist of SiO{sub 2} and include Al{sub 2}O{sub 3}, FeO, and K{sub 2}O. The volumetric flow rate and the pressure difference between the inlet and outlet of the column were measured, and the permeability was calculated. At the same time, the concentrations of elements in the fluid were measured by ICP-AES. The experimental result showed that permeability decreased gradually, although the silica sand was continuously dissolved in the column. The behavior of the permeability is considered to be the result from the rearrangement of the particles, or precipitation of secondary mineral. In the column test using the silica sand as packed mineral, the flow-path seems to be clogged by the rearrangement of the particles rather than the increase of the pore space between the particles. (authors)

Hideo Usui; Yuichi Niibori; Hitoshi Mimura [Department of Quantum Science and Energy Engineering, Graduate School of Engineering, Tohoku University, Aramaki Aza Aoba 6-6-01-2, Aoba-ku, Sendai, 980-8579 (Japan); Osamu Tochiyama [Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, Katahira 2-1-1, Aoba-ku, Sendai, 980-8577 (Japan)

2007-07-01

80

Modern analytical supercritical fluid chromatography using columns packed with sub-2 ?m particles: a tutorial.  

PubMed

This tutorial provides an overview of the possibilities, limitations and analytical conditions of modern analytical supercritical fluid chromatography (SFC) using columns packed with sub-2 ?m particles. In particular, it gives a detailed overview of commercially available modern SFC instrumentation and the detectors that can be employed (UV, MS, ELSD, FID, etc.). Some advice on the choice of the stationary phase dimensions and chemistries, the nature of the mobile phase (choice of organic modifier and additives) and its flow rate as well as the backpressure and temperature are also provided. Finally, several groups of potentially problematic compounds, including lipophilic compounds, hydrophilic substances and basic drugs, are discussed in detail. All these families of analytes can be resolved with SFC but require specific analytical conditions. PMID:24759745

Nováková, Lucie; Perrenoud, Alexandre Grand-Guillaume; Francois, Isabelle; West, Caroline; Lesellier, Eric; Guillarme, Davy

2014-05-01

81

Continuous phosphorus removal from water by physicochemical method using zero valent iron packed column.  

PubMed

Excessive phosphorus in aquatic systems causes algal bloom resulting in eutrophication. To treat wastewater including effluent of wastewater treatment plant containing various amounts of phosphorus, a series of continuous experiments on removal of phosphorus from water were performed by using an electrochemical method. The spherical type of zero valent iron (ZVI) and silica sand were packed at appropriate volume ratio of 1:2 in a cylindrical column. An electric potential was applied externally, which can be changed as per the operational requirement. The results indicate that optimum hydraulic retention time of 36 min was required to meet the effluent standards with our laboratory-scale experimental setup. Lower amounts of phosphorus were removed by precipitation due to contact with iron, and additional electric potential was not required. In order to remove high amounts of phosphorus (around 150 mg/L as phosphate), external electric potential of 600 V was applied to the reactor. As the precipitation of phosphate mainly occurs at neutral pH, it is likely that FeHPO4 will be the main phosphorus-containing compound. Through the results of the large-scale experiments, the ZVI packed reactor can be used as a filter for removal of phosphorus of less than 10 mg/L as phosphate concentration. PMID:25225938

Jeong, Joo-Young; Ahn, Byoung-Min; Kim, Yu-Jin; Park, Joo-Yang

2014-01-01

82

A unified classification of stationary phases for packed column supercritical fluid chromatography.  

PubMed

The use of supercritical fluids as chromatographic mobile phases allows to obtain rapid separations with high efficiency on packed columns, which could favour the replacement of numerous HPLC methods by supercritical fluid chromatography (SFC) ones. Moreover, despite some unexpected chromatographic behaviours, general retention rules are now well understood, and mainly depend on the nature of the stationary phase. The use of polar stationary phases improves the retention of polar compounds, when C18-bonded silica favours the retention of hydrocarbonaceous compounds. In this sense, reversed-phase and normal-phase chromatography can be achieved in SFC, as in HPLC. However, these two domains are clearly separated in HPLC due to the opposite polarity of the mobile phases used for each method. In SFC, the same mobile phase can be used with both polar and non-polar stationary phases. Consequently, the need for a novel classification of stationary phases in SFC appears, allowing a unification of the classical reversed- and normal-phase domains. In this objective, the paper presents the development of a five-dimensional classification based on retention data for 94-111 solutes, using 28 commercially available columns representative of three major types of stationary phases. This classification diagram is based on a linear solvation energy relationship, on the use of solvation vectors and the calculation of similarity factors between the different chromatographic systems. This classification will be of great help in the choice of the well-suited stationary phase, either in regards of a particular separation or to improve the coupling of columns with complementary properties. PMID:18384800

West, C; Lesellier, E

2008-05-16

83

1.1?m Superficially porous particles for liquid chromatography: Part II: Column packing and chromatographic performance.  

PubMed

The predicted advantages of superficially porous particles over totally porous particles are decreased eddy dispersion, longitudinal diffusion, and resistance to mass transfer contributions to the theoretical plate height. While sub-2 micron superficially porous particles are commercially available, further improvements in performance are predicted by decreasing the particle diameter and decreasing the porous layer thickness. 1.1?m superficially porous particles with 187? pores have been synthesized using a layer-by-layer method tuned for production of smaller diameter particles. Following synthesis, these particles were packed into 30?m i.d. capillary columns and their chromatographic performance evaluated using electrochemical detection. Based on the initial studies, the column efficiency did not meet theory, but was similar to the commercially available products tested. It is believed that the column packing process plays a critical role in the sub-par column performance. To determine if column efficiency could be predicted by solvent-particle interactions, in-solution optical microscopy and sedimentation velocity of particles in various slurry solvents were investigated and compared to column performance. Aggregating slurry solvents, such as methanol were found to produce columns with increased efficiency. The hmin for a column packed with an acetone slurry and a methanol slurry at 3mg/mL were found to be 6.3 and 3.5, respectively. Increasing the slurry concentration to 25mg/mL further improved the efficiency, producing a column with an hmin of 2.6. These efficiency results were accurately predicted by in-solution optical microscopy. PMID:25578043

Blue, Laura E; Jorgenson, James W

2015-02-01

84

Determination of kinetic parameters in the biosorption of copper(II) on Cladophora sp., in a packed bed column reactor  

Microsoft Academic Search

In this study, the biosorption of copper(II) ions to the green alga Cladophora sp. was investigated in a packed bed column reactor as a function of flow rate and inlet copper(II) concentration. These two parameters affected the external mass transfer and adsorption rates directly. Mass transfer coefficients were determined from the Wakao Equation evaluating the breakthrough curves obtained at different

Z. Aksu; T. Kutsal

1998-01-01

85

COAL GASIFICATION/GAS CLEANUP TEST FACILITY. VOLUME 4. A MATHEMATICAL MODEL OF THE PACKED COLUMN ACID GAS ABSORBER  

EPA Science Inventory

The report describes a mathematical model for adiabatic operation of a packed-column absorber designed to remove acid gases from coal gasification crude product gas. It also gives results of experiments with a small pilot-scale coal gasification/gas cleaning facility designed to ...

86

Feasability of neat carbon dioxide packed column comprehensive two dimensional supercritical fluid chromatography.  

PubMed

The design and implementation of comprehensive two dimensional supercritical fluid chromatography (SFC) using neat carbon dioxide as the mobile phase is described. Two conventional supercritical fluid chromatographs were hyphenated via an on line comprehensive 2D liquid chromatography like interface; it consisted of a two loop switching valve allowing the collection of the first dimension column effluent, the second dimension separation of a fraction being performed during the time allowed for the collection of the subsequent fraction of the first dimension eluent. Both dimension separations were monitored via UV detection; for the second dimension, the main flow was diverted to implement flame ionisation detection for the detection of hydrocarbons and the construction of the corresponding colour plots. Some key parameters related to the interfacing of the two dimensions and the chromatographic conditions used in both dimensions are discussed. In this preliminary report, the feasibility of comprehensive 2D SFC is demonstrated on synthetic mixtures of hydrocarbons and its potential on real sample analysis is illustrated by the separation of coal derived vacuum distillate. PMID:22533910

Guibal, Pierre; Thiébaut, Didier; Sassiat, Patrick; Vial, Jérôme

2012-09-14

87

Towards high peak capacity separations in normal pressure nanoflow liquid chromatography using meter long packed capillary columns.  

PubMed

Single shot proteomics is a promising approach to high throughput proteomics analysis. In this strategy, long capillary columns are needed to perform long and shallow gradients to achieve high peak capacity and good peak width for informative mass spectrometric detection. Herein, we report that meter long capillary columns, packed with 5?m particulate material, can be facilely fabricated based on single particle fritting technology. The long columns could reliably generate high peak capacities of 800 in 10h long gradients for protein digest separations. The operation was within the pressure range (40MPa) of the most widely used normal pressure nanoLC systems. Due to the excellent life time (>100 injections) and inter-column performance consistency, the meter long capillary columns reported here should be of practical usefulness in single shot proteomics without the need for ultra-high pressure instrumentation. PMID:25441907

Han, Jing; Ye, Linquan; Xu, Lingjia; Zhou, Zhuoheng; Gao, Fan; Xiao, Zhiliang; Wang, Qiuquan; Zhang, Bo

2014-12-10

88

Effects of distillation system and yeast strain on the aroma profile of Albariño (Vitis vinifera L.) grape pomace spirits.  

PubMed

Orujo is a traditional alcoholic beverage produced in Galicia (northwest Spain) from distillation of grape pomace, a byproduct of the winemaking industry. In this study, the effect of the distillation system (copper charentais alembic versus packed column) and the yeast strain (native yeast L1 versus commercial yeast L2) on the chemical and sensory characteristics of orujo obtained from Albariño (Vitis vinifera L.) grape pomace has been analyzed. Principal component analysis, with two components explaining 74% of the variance, is able to clearly differentiate the distillates according to distillation system and yeast strain. Principal component 1, mainly defined by C6-C12 esters, isoamyl octanoate, and methanol, differentiates L1 from L2 distillates. In turn, principal component 2, mainly defined by linear alcohols, linalool, and 1-hexenol, differentiates alembic from packed column distillates. In addition, an aroma descriptive test reveals that the distillate obtained with a packed column from a pomace fermented with L1 presented the highest positive general impression, which is associated with the highest fruity and smallest solvent aroma scores. Moreover, chemical analysis shows that use of a packed column increases average ethanol recovery by 12%, increases the concentration of C6-C12 esters by 25%, and reduces the concentration of higher alcohols by 21%. In turn, L2 yeast obtained lower scores in the alembic distillates aroma profile. In addition, with L1, 9% higher ethanol yields were achieved, and L2 distillates contained 34%-40% more methanol than L1 distillates. PMID:25307564

Arrieta-Garay, Y; Blanco, P; López-Vázquez, C; Rodríguez-Bencomo, J J; Pérez-Correa, J R; López, F; Orriols, I

2014-10-29

89

Cotransport of clay colloids and viruses in water saturated columns packed with glass beads  

NASA Astrophysics Data System (ADS)

This study is focused on the cotransport of clay colloids and viruses in saturated columns packed with glass beads. Bacteriophages MS2 and ?X174 were used as model viruses, and kaolinite (kGa-1b) and montmorillonite (STx-1b) as model colloids. Virus and clay transport as well as virus-clay cotransport were examined at three pore water velocities (0.38, 0.74, and 1.21 cm/min). The results indicated that the mass recovery of viruses and clay colloids decreased as the pore water velocity decreased; whereas, for the cotransport experiments no clear trend was observed. Temporal moments of the breakthrough concentrations suggested that, in the absence of clay colloids, both MS2 and ?X174 traveled faster than the conservative tracer only at the highest pore water velocity tested. For the other two velocities both viruses were slightly retarded. The presence of clays significantly influenced the irreversible virus deposition onto glass beads. Both MS2 and ?X174 were attached in greater amounts onto KGa-1b than STx-1b. Also, MS2 exhibited greater affinity than ?X174 for both clays. The results suggest that Lewis acid-base interactions worked to the advantage of clay colloid attachment but did not significantly affect virus attachment onto glass beads. Schematic illustration of the six concentration components involved in cotransport experiments of this study.

Chrysikopoulos, C.; Syngouna, V. I.

2012-12-01

90

Prediction of the Trayed Distillation Column Mass-Transfer Performance by Neural Networks  

E-print Network

developed for the prediction of the sieve-tray efficiency and structured packing height equivalent predictions. Introduction Overview. In a previous work,2 the height equivalent to a theoretical plate (HETP connection conveys a signal from one node to another labeled by a "weight", that indicates the extent

Eldridge, R. Bruce

91

RESULTS OF THE STUDY OF POLPAK PACKING FOR HIGH EFFICIENCY COLUMNS FOR SEPARATION OF ISOTOPES  

Microsoft Academic Search

A description is given of a new polpak packing for laboratory and ; commercial scale coiumns. Resistance of flow, separation capacity, and hold-up ; were studied in dependence on the characteristic size of packing elements, feed ; rate, and pressure. The packing examined is characterized by high efficiency; ; the pressure drop per theoretical plate is very low. Therefore the

A. Selecki; B. Tyminski

1963-01-01

92

Investigation of the column performance of cadmium(II) biosorption by Cladophora crispata flocs in a packed bed  

SciTech Connect

In this study the biosorption of cadmium(II) ions to dried flocs of Cladophora crispata, a kind of green algae, was investigated in a packed bed column. The cadmium(II) removal performance of the column was investigated as a function of the cadmium(II)-bearing solution flow rate and the inlet cadmium(II) concentration. Removal and total removal percentages of cadmium(II) related to flow volume were determined by evaluating the breakthrough curves obtained at three different flow rates for two different constant inlet concentrations. At the lowest flow rate the effect of inlet cadmium(II) concentration on the column capacity was also investigated. Data confirmed that early saturation and lower cadmium(II) removals were observed at higher flow rates and at higher cadmium(II) concentrations. Column experiments also showed that maximum specific cadmium(II) uptake values of C. crispata flocs were as high as those of other biomass sorbents.

Aksu, Z.; Kutsal, T.; Caglar, A. [Hacettepe Univ., Ankara (Turkey). Chemical Engineering Dept.; Oezer, D.; Oezer, A. [Firat Univ., Elazig (Turkey). Chemical Engineering Dept.

1998-03-01

93

Effect of gravity on colloid transport through water-saturated columns packed with glass beads: modeling and experiments.  

PubMed

The role of gravitational force on colloid transport in water-saturated columns packed with glass beads was investigated. Transport experiments were performed with colloids (clays: kaolinite KGa-1b, montmorillonite STx-1b). The packed columns were placed in various orientations (horizontal, vertical, and diagonal) and a steady flow rate of Q = 1.5 mL/min was applied in both up-flow and down-flow modes. All experiments were conducted under electrostatically unfavorable conditions. The experimental data were fitted with a newly developed, analytical, one-dimensional, colloid transport model. The effect of gravity is incorporated in the mathematical model by combining the interstitial velocity (advection) with the settling velocity (gravity effect). The results revealed that flow direction influences colloid transport in porous media. The rate of particle deposition was shown to be greater for up-flow than for down-flow direction, suggesting that gravity was a significant driving force for colloid deposition. PMID:24857560

Chrysikopoulos, Constantinos V; Syngouna, Vasiliki I

2014-06-17

94

Experimental investigation of virus and clay particles cotransport in partially saturated columns packed with glass beads.  

PubMed

Suspended clay particles in groundwater can play a significant role as carriers of viruses, because, depending on the physicochemical conditions, clay particles may facilitate or hinder the mobility of viruses. This experimental study examines the effects of clay colloids on the transport of viruses in variably saturated porous media. All cotransport experiments were conducted in both saturated and partially saturated columns packed with glass beads, using bacteriophages MS2 and ?X174 as model viruses, and kaolinite (KGa-1b) and montmorillonite (STx-1b) as model clay colloids. The various experimental collision efficiencies were determined using the classical colloid filtration theory. The experimental data indicated that the mass recovery of viruses and clay colloids decreased as the water saturation decreased. Temporal moments of the various breakthrough concentrations collected, suggested that the presence of clays significantly influenced virus transport and irreversible deposition onto glass beads. The mass recovery of both viruses, based on total effluent virus concentrations, was shown to reduce in the presence of suspended clay particles. Furthermore, the transport of suspended virus and clay-virus particles was retarded, compared to the conservative tracer. Under unsaturated conditions both clay particles facilitated the transport of ?X174, while hindered the transport of MS2. Moreover, the surface properties of viruses, clays and glass beads were employed for the construction of classical DLVO and capillary potential energy profiles, and the results suggested that capillary forces play a significant role on colloid retention. It was estimated that the capillary potential energy of MS2 is lower than that of ?X174, and the capillary potential energy of KGa-1b is lower than that of STx-1b, assuming that the protrusion distance through the water film is the same for each pair of particles. Moreover, the capillary potential energy is several orders of magnitude greater than the DLVO potential energy. PMID:25460700

Syngouna, Vasiliki I; Chrysikopoulos, Constantinos V

2015-02-15

95

Two-Phase Flow in Packed Columns and Generation of Bubbly Suspensions for Chemical Processing in Space  

NASA Technical Reports Server (NTRS)

For long-duration space missions, the life support and In-Situ Resource Utilization (ISRU) systems necessary to lower the mass and volume of consumables carried from Earth will require more sophisticated chemical processing technologies involving gas-liquid two-phase flows. This paper discusses some preliminary two-phase flow work in packed columns and generation of bubbly suspensions, two types of flow systems that can exist in a number of chemical processing devices. The experimental hardware for a co-current flow, packed column operated in two ground-based low gravity facilities (two-second drop tower and KC- 135 low-gravity aircraft) is described. The preliminary results of this experimental work are discussed. The flow regimes observed and the conditions under which these flow regimes occur are compared with the available co-current packed column experimental work performed in normal gravity. For bubbly suspensions, the experimental hardware for generation of uniformly sized bubbles in Couette flow in microgravity conditions is described. Experimental work was performed on a number of bubbler designs, and the capillary bubble tube was found to produce the most consistent size bubbles. Low air flow rates and low Couette flow produce consistent 2-3 mm bubbles, the size of interest for the "Behavior of Rapidly Sheared Bubbly Suspension" flight experiment. Finally the mass transfer implications of these two-phase flows is qualitatively discussed.

Motil, Brian J.; Green, R. D.; Nahra, H. K.; Sridhar, K. R.

2000-01-01

96

Rapid development of core-shell column technology: accurate measurements of the intrinsic column efficiency of narrow-bore columns packed with 4.6 down to 1.3 ?m superficially porous particles.  

PubMed

The intrinsic heights equivalent to a theoretical plate (HETPs) of 31 narrow-bore and wide-bore columns packed with four different brands of core-shell particles were accurately measured on an optimized vHPLC instrument (1290 Infinity system) that has an extra-column volume variance of 13.6±0.3 ?L(2). These results were derived from the slopes of the linear plots of the apparent plate heights of each column versus the reciprocal of (1+k')(2) for seven homologous compounds with a linear regression coefficient larger than 0.999. The results show that the kinetic performance of narrow-bore columns packed with core-shell particles increases almost linearly with decreasing particle diameter. The optimum reduced plate heights increase slightly from 1.6 to 1.9 with decreasing particle sizes from 4.6 to 1.3 ?m. This confirms that wide-bore columns provide better efficiencies than narrow-bore columns. PMID:24529958

Gritti, Fabrice; Guiochon, Georges

2014-03-14

97

Catalytic distillation structure  

DOEpatents

Catalytic distillation structure for use in reaction distillation columns, a providing reaction sites and distillation structure and consisting of a catalyst component and a resilient component intimately associated therewith. The resilient component has at least about 70 volume % open space and being present with the catalyst component in an amount such that the catalytic distillation structure consist of at least 10 volume % open space.

Smith, Jr., Lawrence A. (Bellaire, TX)

1984-01-01

98

Particle-packed column versus silica-based monolithic column for liquid chromatography-electrospray-linear ion trap-tandem mass spectrometry multiallergen trace analysis in foods.  

PubMed

A bicarbonate buffer-based extraction method for the simultaneous analysis of five nut allergens (Ana o 2, cashew-nut; Cor a 9, hazelnut; Pru 1, almond; Ara h3/4, peanut; Jug r 4, walnut) in cereals and biscuits using liquid chromatography-electrospray-linear ion trap-tandem mass spectrometry (LC-ESI-LIT-MS(2)) was developed and validated. The method was based on our earlier published LC-MS(2)-based method in a research frame aimed at the identification and determination of hidden allergens in foods by using selective biomarker peptides. A C18 particle-packed column and a silica-based C18 monolithic column were compared in terms of chromatographic performances, such as peak shape, resolution, analysis time and selectivity. The C18 particle-packed column exhibited better performances and was further used for method development and validation. By operating under MS(2) selected reaction monitoring (SRM) acquisition mode, linearity, limits of detection (LOD) and quantitation, trueness and precision were evaluated on breakfast samples enriched with a mix of the five nuts. Good linearity of the matrix matched-calibration curves was obtained and detection limit values generally varied from 14 to 55 mg nut/kg matrix. Recoveries were in the 76±4% to 94±3% range with RSD <15%. The capabilities of LIT to perform MS(n) fragmentation was exploited to improve selectivity of the analysis, and the LC-(SRM) MS(2) method was compared in terms of LOD, linearity, precision and accuracy with a LC-(SRM) MS(3) method. Finally, both the LC-MS(2) and LC-MS(3) methods were successfully applied to the analysis of nut traces in commercially available breakfast cereals and biscuits. PMID:21030028

Bignardi, Chiara; Elviri, Lisa; Penna, Andrea; Careri, Maria; Mangia, Alessandro

2010-11-26

99

Bilirubin removal from human plasma in a packed-bed column system with dye-affinity microbeads  

Microsoft Academic Search

A dye-ligand, Cibacron Blue F3GA, was covalently coupled with the poly(EGDMA-HEMA) microbeads. The affinity sorbent carrying 16.5 ?mol Cibacron Blue F3GA per gram polymer was then used to remove bilirubin from human plasma in a packed-bed column system. Bilirubin adsorption from human plasma on the unmodified poly(EGDMA-HEMA) microbeads was 0.32 mg\\/g, while much higher adsorption values, up to 24.2 mg\\/g,

Adil Denizli; Mustafa Kocakulak; Erhan Pi?kin

1998-01-01

100

Characterization and kinetic performance of 2.1 × 100 mm production columns packed with new 1.6 ?m superficially porous particles.  

PubMed

The overall kinetic performance of three production columns (2.1 mm × 100 mm format) packed with 1.6 ?m superficially porous CORTECS-C18 + particles was assessed on a low-dispersive I-class ACQUITY instrument. The values of their minimum intrinsic reduced plate heights (hmin = 1.42, 1.57, and 1.75) were measured at room temperature (295 K) for a small molecule (naphthalene) with an acetonitrile/water eluent mixture (75:25, v/v). These narrow-bore columns provide an average intrinsic efficiency of 395 000 plates per meter. The gradient separation of 14 small molecules shows that these columns have a peak capacity about 25% larger than similar ones packed with fully porous BEH-C18 particles (1.7 ?m) or shorter (50 mm) columns packed with smaller core-shell particles (1.3 ?m) operated under very high pressure (>1000 bar) for steep gradient elution (analysis time 80 s). In contrast, because their permeabilities are lower than those of columns packed with larger core-shell particles, their peak capacities are 25% smaller than those of narrow-bore columns packed with standard 2.7 ?m core-shell particles. PMID:25219365

Gritti, Fabrice; Shiner, Stephen; Fairchild, Jacob N; Guiochon, Georges

2014-12-01

101

Physical properties and structure of fine core-shell particles used as packing materials for chromatography relationships between particle characteristics and column performance  

SciTech Connect

The recent development of new brands of packing materials made of fine porous-shell particles, e.g., Halo and Kinetex, has brought great improvements in potential column efficiency, demanding considerable progress in the design of chromatographic instruments. Columns packed with Halo and Kinetex particles provide minimum values of their reduced plate heights of nearly 1.5 and 1.2, respectively. These packing materials have physical properties that set them apart from conventional porous particles. The kinetic performance of 4.6 mm I.D. columns packed with these two new materials is analyzed based on the results of a series of nine independent and complementary experiments: low-temperature nitrogen adsorption (LTNA), scanning electron microscopy (SEM), inverse size-exclusion chromatography (ISEC), Coulter counter particle size distributions, pycnometry, height equivalent to a theoretical plate (HETP), peak parking method (PP), total pore blocking method (TPB), and local electrochemical detection across the column exit section (LED). The results of this work establish links between the physical properties of these superficially porous particles and the excellent kinetic performance of columns packed with them. It clarifies the fundamental origin of the difference in the chromatographic performances of the Halo and the Kinetex columns.

Gritti, Fabrice [University of Tennessee, Knoxville (UTK); Guiochon, Georges A [ORNL

2010-01-01

102

Extraction of squalene from shark liver oil in a packed column using supercritical carbon dioxide  

SciTech Connect

Continuous extraction of squalene from shark liver oil using supercritical carbon dioxide was carried out in both laboratory and pilot scale plant. The shark liver oil contained around 50% by weight squalene, which was recovered as the main extract stream. The other major components in the oil were triglycerides, which were recovered as raffinate, and pristane, which was recovered as a second extract stream. Separation performance was determined as a function of temperature; pressure; oil to carbon dioxide flow rate ratio, packed height and type of packing; and reflux ratio. The pressure, temperature, and feed oil concentration of squalene determined the maximum loading of oil in carbon dioxide. The oil to carbon dioxide ratio determined the squalene concentration in both the product stream and raffinate stream. The ratio of oil flow rate to the flow rate of squalene required to just saturate carbon dioxide was found to be a useful correlating parameter for the oil loadings and product compositions. Of the three packings investigated, wire wool gave the best separation efficiency and Raschig rings the worst efficiency. Mass transfer correlations from the literature were used to estimate the number of transfer units (NTU) from experimental data and literature correlations. NTU`s from the experimental data were comparable to predictions at a pilot scale but were underpredicted at the laboratory scale. The use of reflux at the pilot scale enabled the concentration of squalene in the product stream to be increased from 92% by mass to a maximum of 99% by mass at fractionation conditions of 250 bar and 333 K.

Catchpole, O.J.; Kamp, J.C. von; Grey, J.B. [Industrial Research Limited, Lower Hutt (New Zealand)] [Industrial Research Limited, Lower Hutt (New Zealand)

1997-10-01

103

Description and comparison of chromatographic tests and chemometric methods for packed column classification.  

PubMed

The main tests developed in last 20 years to investigate the chromatographic behaviour and the stationary phase properties are described in this paper. These properties are the hydrophobicity, depending on the surface area and the bonding density, the number of accessible residual silanol groups having sometimes different acidity, which can interact with neutral solutes by hydrogen bonds or with the ionic form of basic compounds and the shape or steric selectivity, depending on both the functionality of the silanising agent and the bonding density. Two types of tests are performed, either based on key solutes having well defined properties such as phenol, caffeine, amitriptyline, benzylamine, acenaphtene, o-terphenyl, triphenylene, p-ethylaniline, carotenoid pigments, or on retention models (solvation parameter, hydrophobic subtraction) obtained from the analyses of numerous and varied compounds. Thus, the chromatographic properties are either related to selectivities or retention factors calculated from key solutes, or they are described by interaction coefficients provided by multilinear regression from retention models. Three types of comparison methods are used based on these data. First, simple plots allow the study of differences between the columns as regards to one or two properties. Columns located in the same area of the plot display close properties. Second, chemometric methods such as principal component analysis (PCA) or hierarchical cluster analysis (HCA) can be performed to compare columns. In this case, all the studied properties are included in the comparison, done either by data projection to reduce the space in which the information is located (PCA) or by distance calculation and comparison for drawing a classification (HCA). Neighbouring columns are expected to provide identical chromatographic performances. These two chemometric methods can be used together, PCA before HCA. The third way is to calculate a discrimination factor from a reference column, through calculation methods based on the Pythagorean Theorem: the lower this factor, the closer the column properties. Following the presentation of the analytical conditions, the compounds and the data treatments used by the teams working in this field, the pertinence of the different selectivities, i.e. of the different probe solute couples or of the different interaction coefficients, are discussed as regards their discrimination capacity. The accuracy of chemometric treatments in the discrimination of stationary phases having different functionalities (octadecylsiloxane (ODS), cyano, fluorinated, phenyl, polar embedded group or "aqua" type) will be discussed, as well as their performances in the finer ODS discrimination. New two-dimensional plots, from data gained by different studies will be suggested, to improve the classification of stationary phases having different nature of bonded chains. PMID:17467721

Lesellier, E; West, C

2007-07-27

104

Packed bed column studies on lead(II) removal from industrial wastewater by modified Agaricus bisporus.  

PubMed

Agaricus bisporus showed best performance in removing Pb(II) with a biosorption capacity of 86.4 mg g(-1) after modification with NaOH. In this work, the removal of Pb(II) from wastewater has been conducted in column mode. The metal removal was dependent on the flow rate, initial metal concentration, and bed height. The experimental data obtained from the biosorption process was successfully correlated with the Bohart-Adams, Thomas, and Yoon-Nelson models. Five biosorption-desorption cycles yielded 95.34%, 92.27%, 90.13%, 86.75%, and 81.52% regeneration, respectively. Pb(II) could be effectively removed from industrial wastewater; some metal ions and organics were also removed concomitantly, and the obtained effluent had characteristics of better quality. The results confirmed that modified A. bisporus could be applied for the removal of heavy metals from industrial wastewater in a continuous column process. PMID:24321609

Long, Yunchuan; Lei, Daiyin; Ni, Jiangxia; Ren, Zhuolin; Chen, Can; Xu, Heng

2014-01-01

105

Comparison of Packed Beds and Qiagen Columns for Recovering Trace Amounts of B. anthracis DNA from Liquid Suspensions  

SciTech Connect

The goal of this work was to optimize and evaluate LLNL's in-bed amplification technology to improve the level of detection for suspensions containing trace amounts of anthracis DNA. The binding/cleaning performance of the packed bed is compared to the conventional commercial approach; Qiagen column cleanup and elution, followed by detection through an ex-situ amplification process. Five liquid suspensions were spiked with B.anthracis DNA in concentration series. These suspensions were: (1) water, (2) water with EDTA, (3) dirty water from carpet extraction, (4) dirty carpet extraction with phosphate buffered saline (PBS) plus 0.1% Tween 20 plus 0.1% gelatin, and (5) a subway aerosol collected in water. Each suspension matrix was spiked with DNA and injected (in replicate) into either Qiagen Microcolumns (using the kit processing instructions) or LLNL's packed bed (using the LLNL in-bed purification and amplification protocol). The process output was assayed by quantitative polymerase chain reaction (QPCR). Table ES-1 shows the level of DNA (pg per 100 uL of input suspension) that resulted in successful amplification for all reactions (X=Y), and the level for which at least one of the reactions was successful (X>0). For each suspension and DNA concentration, there were Y QPCR assays of which X showed successful amplification. LLNL's packed bed technology outperformed Qiagen Microcolumns for all five suspensions, typically by one order of magnitude in both the limit of assured detection (all reactions positive), and the lower limit of detection (some reactions positive).

Sorensen, K; Arroyo, E; Erler, A; Christian, A T; Camp, D; Wheeler, E K

2006-06-23

106

Adsorption performance of packed bed column for nitrate removal using PAN-oxime-nano Fe2O3  

PubMed Central

A continuous fixed bed study was carried out by using PAN-oxime-nano Fe2O3 as a sorbent for the removal of nitrate from aqueous solution. The effect of factors, such as flow rate (2, 5 and 7 mL/min) and bed depth (5, 10 and 15 cm) were studied. Data confirmed that the breakthrough curves were dependent on flow rate and bed depth. The adsoption capacities observed in diffent conditions of flow rates (2,5 and 7 mL/min) were 11.65, 24.38 and 25.89, respectively. Thomas model was applied to experimental data to predict the breakthrough curves using linear regression and to determine the characteristic parameters of the packed bed column. Bed depth/service time analysis (BDST) model was used to investigate the effect of bed depth on breakthrough curves. The results showed that Thomas model was suitable for the normal description of breakthrough curve at the experimental condition. The data were in good agreement with BDST model with R2?>?0.98. Statistical analyses were performed on fluoride removal obtained from different flow rates using SPSS16 software by applying Kruskal- Wallis test. These findings suggested that PAN-oxime-nano Fe2O3 in the column structure presents a great potential in removal of nitrate from aqueous solutions. PMID:25045525

2014-01-01

107

Evaluation by respirometry of the degradability of retort water using a shale ash and overburden packed column.  

PubMed

Oil shale processing produces an aqueous wastewater stream known as retort water. The fate of the organic content of retort water from the Stuart oil shale project (Gladstone, Queensland) is examined in a proposed packed bed treatment system consisting of a 1:1 mixture of residual shale from the retorting process and mining overburden. The retort water had a neutral pH and an average unfiltered TOC of 2,900 mg 1(-1). The inorganic composition of the retort water was dominated by NH4+. Only 40% of the total organic carbon (TOC) in the retort water was identifiable, and this was dominated by carboxylic acids. In addition to monitoring influent and effluent TOC concentrations, CO2 evolution was monitored on line by continuous measurements of headspace concentrations and air flow rates. The column was run for 64 days before it blocked and was dismantled for analysis. Over 98% of the TOC was removed from the retort water. Respirometry measurements were confounded by CO2 production from inorganic sources. Based on predictions with the chemical equilibrium package PHREEQE, approximately 15% of the total CO2 production arose from the reaction of NH4+ with carbonates. The balance of the CO2 production accounted for at least 80% of the carbon removed from the retort water. Direct measurements of solid organic carbon showed that approximately 20% of the influent carbon was held-up in the top 20cm of the column. Less than 20% of this held-up carbon was present as either biomass or as adsorbed species. Therefore, the column was ultimately blocked by either extracellular polymeric substances or by a sludge that had precipitated out of the retort water. PMID:16128388

Clarke, W P; Ho, N M; Taylor, M; Coombs, S; Bell, P R; Picaro, T

2005-08-01

108

Cotransport of clay colloids and viruses in water saturated columns packed with glass beads  

NASA Astrophysics Data System (ADS)

This study is focused on the cotransport of clay colloids and viruses in saturatedcolumns packed with glass beads. Bacteriophages MS2 and ??174 were used as model viruses, and kaolinite (kGa-1b) and montmorillonite (STx-1b) as model colloids.The effect of three pore water velocities (0.38, 0.74, and 1.21 cm/min) on virus transport and virus-clay cotransport was examined. The results indicated that the mass recovery of viruses and clay colloids decreased as the pore water velocity decreased; whereas, for the cotransport experiments no clear trend was observed. Temporal moments of the breakthrough concentrations suggested that, in the absence of clay colloids, both MS2 and ?X174 traveled faster than the conservative tracer only at the highest pore water velocity tested. For the other two velocities both viruses were slightly retarded. The presence of clays significantly influenced the irreversible virus deposition. Both MS2 and ?X174 were attached in greater amounts onto KGa-1b than STx-1b with MS2 exhibiting greater affinity than ?X174 for both clays. The results suggest that electrostatic interactions play a vital role on virus adsorption onto both glass beads and clay colloids.

Syngouna, V. I.; Chrysikopoulos, C. V.

2012-04-01

109

Catalytic distillation structure  

DOEpatents

Catalytic distillation structure is described for use in reaction distillation columns, and provides reaction sites and distillation structure consisting of a catalyst component and a resilient component intimately associated therewith. The resilient component has at least about 70 volume % open space and is present with the catalyst component in an amount such that the catalytic distillation structure consists of at least 10 volume % open space. 10 figs.

Smith, L.A. Jr.

1984-04-17

110

Continuous adsorption of natural organic matters in a column packed with carbon nanotubes  

PubMed Central

In the present study, continuous adsorption experiments were carried out in an adsorption column to survey the efficiency of the carbon nanotubes (CNTs) for removal of natural organic matters (NOMs) from aqueous solution. Parameters such as mass of CNTs, initial NOMs concentration were evaluated and also the breakthrough curves were obtained. Experiments performed with various initial NOMs concentration and various CNTs masses. The breakthrough period was longer at lower initial NOMs concentration. Increase of the initial NOMs concentration, expectedly, resulted in the faster saturation of the CNTs bed. The adsorption capacities for multi wall carbon nanotubes (MWCNT) and single wall carbon nanotubes (SWCNT) in highest initial NOMs concentration were 53.46 and 66.24 mg/g, respectively. The effect of amount of CNTs on breakthrough time and volume of treated water was investigated and resulted that with an increase in the mass of CNTs, breakthrough time occurs very late and the volume of treated water increased. These findings suggested that CNTs present a great potential in removal of NOMs from aqueous solutions. PMID:24499604

2013-01-01

111

Speed-resolution properties of columns packed with new 4.6 ?m Kinetex-C(18) core-shell particles.  

PubMed

The achievable separation speed and resolution of columns packed with the new 4.6 ?m Kinetex particles were characterized by their permeability and their plate heights, measured meticulously. Their specific permeabilities range between 1.81 and 1.95 × 10(-10)cm(2) and their external porosities between 0.394 and 0.405. The efficiencies of the eluted peaks measured by numerical integration of the whole band concentration provided minimum reduced plate heights for uracil (non-retained) and naphthalene (retained) between 1.3 and 1.5 (H=6.0-6.9 ?m) for two 4.6 mm × 150 mm replicate columns of Kinetex and between 1.6 and 2.0 (H=7.4-9.2 ?m) for two narrow-bore 2.1 mm × 150 mm replicate columns. The most efficient 4.6 mm × 150 mm Kinetex column shows a deviation of one reduced plate height h unit with respect to the infinite diameter column (no wall, no inlet, no outlet endfitting) at high speed. Eventually, the separation speed and the resolution of columns packed with 4.6 ?m core-shell Kinetex particles are better or equivalent to those of columns packed with 2.5 ?m fully porous particles for hold-up times larger than only 10s. These core-shell materials are virtually equivalent to the second generation of silica monolithic columns with the advantage of operating well at pressure drops larger than 200 bar. PMID:23384789

Gritti, Fabrice; Guiochon, Georges

2013-03-01

112

Quantitative Analysis of Transverse Bacterial Migration Induced by Chemotaxis in a Packed Column with Structured Physical Heterogeneity  

PubMed Central

A two-dimensional mathematical model was developed to simulate transport phenomena of chemotactic bacteria in a sand-packed column designed with structured physical heterogeneity in the presence of a localized chemical source. In contrast to mathematical models in previous research work, in which bacteria were typically treated as immobile colloids, this model incorporated a convective-like chemotaxis term to represent chemotactic migration. Consistency between experimental observation and model prediction supported the assertions that (1) dispersion-induced microbial transfer between adjacent conductive zones occurred at the interface and had little influence on bacterial transport in the bulk flow of the permeable layers and (2) the enhanced transverse bacterial migration in chemotactic experiments relative to nonchemotactic controls was mainly due to directed migration toward the chemical source zone. Based on parameter sensitivity analysis, the results showed that chemotactic parameters determined in bulk aqueous fluid were adequate to predict the microbial transport in our intermediate-scale porous media system. Additionally, the analysis of adsorption coefficient values supported the observation of a previous study that microbial deposition to the surface of porous media might be decreased under the effect of chemoattractant gradients. By quantitatively describing bacterial transport and distribution in a heterogeneous system, this mathematical model serves to advance our understanding of chemotaxis and motility effects in granular media systems and provides insights for modeling microbial transport in in situ microbial processes. PMID:20000726

Wang, Meng; Ford, Roseanne M.

2009-01-01

113

Determination of sulfonamides by packed column supercritical fluid chromatography with atmospheric pressure chemical ionisation mass spectrometric detection.  

PubMed

Sulfonamide antibiotics are widely used to prevent bacterial infections in livestock, and residues are commonly found in milk and meat. Packed column supercritical fluid chromatography (pSFC) with detection using ultra violet (UV) and atmospheric pressure chemical ionisation (APCI) mass spectrometry (MS) provides a versatile method for the detection and quantification of six major sulfonamides. The APCI mass spectra for all the sulfonamides consisted of protonated molecules at low cone voltages. Increasing the cone voltage led to informative fragmentation patterns, which provided structural information for identification purposes. The pSFC-APCI-MS technique was shown to be linear (r2 > or = 0.999) over the concentration range 0.1-50 micrograms ml-1 using total ion current. The precision and the accuracy of the system and validation of sample preparation are acceptable, with RSD < 2% and relative error 8%. Selected ion monitoring gave detection limits as follows: sulfadiazine 41, sulfamethoxazole 45, sulfamerazine 47, sulfamethizole 59, sulfamethazine 181 and sulfadimethoxine 96 micrograms l-1, which are lower than the amounts permitted in milk products. The APCI pSFC-MS system was shown to have a high degree of reproducibility. The technique was then applied to determine the above sulfonamides in milk. The results obtained show that there are no matrix effects from the milk and that the detection limits remained as stated for the standard solutions. PMID:10984919

Dost, K; Jones, D C; Davidson, G

2000-07-01

114

Simultaneous biosorption of chromium(VI) and copper(II) on Rhizopus arrhizus in packed column reactor: Application of the competitive Freundlich model  

SciTech Connect

The simultaneous biosorption of Cr(VI) and Cu(II) on free Rhizopus arrhizus in a packed column operated in the continuous mode was investigated and compared to the single metal ion situation. The breakthrough curves were measured as a function of feed flow rate, feed pH, and different combinations of metal ion concentrations in the feed solutions. Column competitive biosorption data were evaluated in terms of the maximum (equilibrium) capacity in the column, the amount of metal loading on the R. arrhizus surface, the adsorption yield, and the total adsorption yield. In the single-ion situation the adsorption isotherms were developed for optimum conditions, and it was seen that the adsorption equilibrium data fit the noncompetitive Freundlich model. For the multicomponent adsorption equilibrium the competitive adsorption isotherms were also developed. The competitive Freundlich model for binary metal mixtures represented most the column adsorption equilibrium data of Cr(VI) and Cu(II) on R. arrhizus satisfactorily.

Sag, Y.; Atacoglu, I.; Kutsal, T.

1999-12-01

115

Efficient control system for low-concentration inorganic gases from a process vent stream: application of surfactants in spray and packed columns.  

PubMed

Control of low-concentration pollutants from a semiconductor process vent stream using a wet-scrubbing technique is a challenging task to meet Taiwan environmental emission standards. An efficient wet-scrubber is designed on a pilot scale and tested to control low concentration acid and base waste-gas emission. The scrubber system consisted of two columns, i.e., a fine spray column [cutoff diameter (based on volume), Dv(50) = 15.63 microm; Sauter mean diameter (SMD) = 7.62 microm], which is especially efficient for NH3 removal as the pH of the spraying liquid is approximately 7 followed by a packed column with a scrubbing liquid pH approximately 9.0 mainly for acids removal. It is observed that use of the surfactants in low concentration about 10(-4) M and 10(-7) M in the spray liquid and in the scrubbing liquid, respectively, remarkably enhances the removal efficiency of the system. A traditional packed column (without the spray column and the surfactant) showed that the removal efficiencies of NH3, HF, and HCl for the inlet concentration range 0.2 to 3 ppm were (n = 5) 22.6+/-3.4%, 43.4+/-5.5%, and 40.4+/-7.4%, respectively. The overall efficiencies of the proposed system (the spray column and the packed column) in the presence of the surfactant in the spray liquid and in the scrubbing liquid forthese three species were found to increase significantly (n = 5) from 60.3+/-3.6 to 82.8+/-6.8%, 59.1+/-2.7 to 83.4+/-4.2%, and 56.2+/-7.3 to 81.0+/-6.7%, respectively. In this work, development of charge on the gas-liquid interface due to the surfactants has been measured and discussed. It is concluded that the presence of charge on the gas-liquid interface is the responsible factor for enhancement of the removal efficiency (mass-transfer in liquid phase). The effects of the type of surfactants, their chain length, concentration in liquid, etc. on the removal efficiency are discussed. Since the pilot tests were performed under the operating conditions similar to most of the wet-scrubbers operated in semiconductors manufacturing facilities for inorganic pollutants, this study can be applied to modify the existing wet-scrubbers to enhance the removal efficiencies, especially for low-concentration pollutants. PMID:15575298

Chein, Hungmin; Aggarwal, Shankar G; Wu, Hsin-Hsien

2004-11-01

116

Gradient HPLC of samples extracted from the green microalga Botryococcus braunii using highly efficient columns packed with 2.6 ?m Kinetex-C?? core-shell particles.  

PubMed

The analysis of the nonpolar extract of the cells of colonies of the green colonial microalgae Botryococcus braunii was performed by gradient HPLC. The growth of B. braunii was stressed by reducing its nitrogen nutrients by 90%, in order to enhance the production of nonpolar compounds. Highly efficient 4.6mm × 100mm columns packed with 2.6 ?m Kinetex-C(18) core-shell particles (Phenomenex, Torrance, CA, USA) were used. The gradient mobile phase was a mixture of acetonitrile and water (70-97%, v/v). Its initial and final compositions during the gradient elution were chosen so that the retention factors of the last eluted compound at the inlet and outlet of the column were 15 and 1, respectively. The highest peak capacity was obtained by optimizing several experimental parameters, including the injected sample volume, the flow rate, and the column length. The highest resolution was obtained by connecting one 4.6 mm × 150 mm and three 4.6mm × 100mm columns (total length 45 cm). The optimum flow rate was 1.5 mL/min, which provided the minimum plate height for the most retained compounds, the optimum inlet pressure was 930 bar and the injected volume 2 ?L. The analysis time was then 14 min for a peak capacity of 121. The trends observed for the variation of the experimental peak capacity with the flow rate and the column length are in excellent agreement with theoretical predictions. PMID:22307155

Gritti, Fabrice; Perdu, Marie-Agnès; Guiochon, Georges

2012-03-16

117

Please cite this article in press as: Z. Li, H. Hong, Retardation of chromate through packed columns of surfactant-modified zeolite, J. Hazard. Mater. (2008), doi:10.1016/j.jhazmat.2008.06.061  

E-print Network

columns of surfactant-modified zeolite, J. Hazard. Mater. (2008), doi:10.1016/j.jhazmat.2008.elsevier.com/locate/jhazmat Retardation of chromate through packed columns of surfactant-modified zeolite Zhaohui Lia,b, , Hanlie Honga Available online xxx Keywords: Cationic surfactant Chromate Retardation Transport Zeolite a b s t r a c

Li, Zhaohui

118

Idle time in the washing and iron concentration in leachate removed: two basic parameters in the desulphurization of coal in a packed column.  

PubMed

Column biodesulphurization of coal is at the experimental stage and is influenced by many variables including temperature, pH, particle size, concentration of iron in solution, among others. Idle time in the washing process and the concentration of dissolved iron in the purged leachate are two variables with a definite effect on the yield of the desulphurization system. In the laboratory, several trials were run with columns packed with coal for different idle times: 1, 2, 3, 5, 6 and 7 days, and for different concentrations of iron in the purged leachate: 500 to 4,000 mg/l. The optimal values for the two variables; that is, those allowing for the highest desulphurization yields, were idle times of 3 and 5 days, which give an elimination of 56% and 49% of pyritic sulphur, respectively, and 3,000 mg/l of iron concentration in the purged leachate, giving a decrease in pyritic sulphur in coal of 57%. PMID:11234958

Cara, J; Aller, A; Otero, M; Morán, A

2001-01-01

119

Comparison of columns packed with porous sub-2 microm particles and superficially porous sub-3 microm particles for peptide analysis at ambient and high temperature.  

PubMed

The objective of this study was to evaluate various chromatographic approaches for peptide analysis. Initially, the ultra-HPLC (UHPLC) strategy, which consists of using columns packed with sub-2 microm particles at a maximal pressure of 1000 bar, was tested. To limit the backpressure generated by small particles, columns packed with superficially porous sub-3 microm particles (fused-core technology) that should theoretically improve mass transfer, particularly beneficial for large biomolecules, were investigated. To evaluate these claims, kinetic plots were constructed in both isocratic and gradient modes at ambient and elevated temperature (up to 90 degrees C). For peptide analysis, both UHPLC and fused-core technologies showed a significant gain in peak capacity when compared with conventional HPLC using 5 mum particles and monolithic supports. Additionally, it has been shown that high temperature was of utmost interest to further improve kinetic performance and peak shape due to the improvement of secondary interaction kinetics. Finally, the best conditions developed for UHPLC using the gradient kinetic plot methodology were applied to the analysis of a complex tryptic digest of various proteins. The expected and experimental peak capacity values obtained were similar. In addition, the resolving power of UHPLC at 60 degrees C was appropriate for resolving complex mixtures of peptides. PMID:20658489

Ruta, Josephine; Guillarme, Davy; Rudaz, Serge; Veuthey, Jean-Luc

2010-08-01

120

High-performance liquid chromatographic column packings with different particle sizes: Chromatographic behavior for the quality analysis of Huanglian Shangqing pill.  

PubMed

The chromatographic separation of traditional Chinese medicines is still a highly challenging task in analytical science with respect to its hundreds and thousands of chemical compounds, while increase of separation efficiency can greatly improve the separation power of chromatographic column for traditional Chinese medicine. In this study, 13 bioactive components in Huanglian Shangqing pill were selected as an index to optimize the separation conditions and evaluate the system suitability of three commercially available columns packed with 1.8, 3.5 and 5.0 ?m particles. The chromatographic separations were obtained by the most appropriate Eclipse Plus C18 column (100 mm × 2.1 mm, 3.5 ?m) within 45 min using gradient elution with water-ammonium acetate (10 mmol/L, pH 5.0) and acetonitrile, at a flow rate of 0.3 mL/min and an operating temperature of 30°C. The quality of Huanglian Shangqing pill was assessed through combining simultaneous quantification of thirteen compounds with fingerprint analysis. For the qualitative analysis, mass spectrometry was used to confirm the 13 compounds. All the validation data conformed to the acceptable requirements. For the fingerprint analysis, 32 peaks were selected as the common peaks at 254 nm to evaluate the similarities among Huanglian Shangqing pills obtained from ten manufacturers. This article is protected by copyright. All rights reserved. PMID:25447791

Yang, Dongzhi; Li, Ying; Yang, Fangxiu; Du, Yan; Li, Yinjie; Zheng, Xiaoxiao; Tang, Daoquan

2014-11-29

121

Synthesis and Development of Porous Polymeric Column Packing and Microchip Detectors for GC Analysis of Extraterrestrial Atmospheres  

NASA Technical Reports Server (NTRS)

This report summarizes the last nine years research accomplishments under Cooperative Agreement NCC2-650 between NASA, Ames Research Center and SETI Institute. Four Major research tasks are conducted: 1. Gas chromatography column development. 2. Pyrosensor development. 3. Micro-machining gas chromatography instrument development. 4. Amino acid analysis and high molecular weight polyamino acid synthesis under prebiotic conditions. The following describes these results.

Shen, Thomas C.

1999-01-01

122

Continuous-flow system for horseradish peroxidase enzyme assay comprising a packed-column, an amperometric detector and a rotating bioreactor.  

PubMed

The roles of chemical kinetics and mass transfer in three types of bioreactors (packed-column reactors, rotating disk bioreactors and amperometric detector), used with continuous-flow sample/reagent(s) processing, are discussed in detail. A normalized quantitative comparison between these types of reactors clearly shows that rotating disk reactors afford a significantly more efficient utilization of active sites and permit the effective utilization of very small amounts of biocatalysts. Horseradish peroxidase (EC 1.11.1.7), in presence of hydrogen peroxide catalyses the oxidation of [Os(bpy)(2)Cl(pyCOOH)]Cl. The electrochemical reduction back of this cosubstrate is detected on glassy carbon electrode surface at 0.00V. Furthermore, the critical effect of substrate and cosubstrate concentration on amperometric immunosensors construction in which HRP is used as an enzymatic label was studied. PMID:18969967

Salinas, Eloy; Torriero, Angel A J; Sanz, María I; Battaglini, Fernando; Raba, Julio

2005-03-31

123

Development and validation of packed column supercritical fluid chromatographic technique for quantification of chlorzoxazone, paracetamol and aceclofenac in their individual and combined dosage forms.  

PubMed

A reproducible, rapid and sensitive method has been developed for the assay of chlorzoxazone (CHL), paracetamol (PCM) and aceclofenac (ACE) in their combined solid dosage forms using packed-column supercritical fluid chromatography (SFC). The analytes were resolved by elution with supercritical carbon dioxide doped with 15% v/v methanol as the modifier on an ACE 5 Phenyl column (150 × 4.6 mm, 5 µm). The detection was carried out at 215 nm using a UV-Visible detector. The densities and polarities of the mobile phase were optimized from the effects of pressure, temperature and modifier concentration on chromatographic parameters like retention time, retention factor, resolution, asymmetry and theoretical plates. Modifier concentration proved to be the most effective means for changing both retention and selectivity. The developed method was validated as per International Conference on Harmonization guidelines. The developed SFC method was compared with a reported high-performance liquid chromatography method for the estimation of CHL, PCM and ACE using Student t-test. With respect to the speed and use of organic solvents, SFC was found to be superior and eco-friendly. The developed SFC method was successfully used for the assay of different marketed formulations containing CHL, PCM and ACE individually and in combination. PMID:22689898

Desai, P P; Patel, N R; Sherikar, O D; Mehta, P J

2012-10-01

124

Preparation and evaluation of packed capillary columns for the separation of nucleic acids by ion-pair reversed-phase high-performance liquid chromatography.  

PubMed

Oligonucleotides and double stranded DNA fragments were separated in 200 microm I.D. capillary columns packed with micropellicular, octadecylated, 2.1 microm poly(styrene-divinylbenzene) particles by ion-pair reversed-phase high-performance liquid chromatography (IP-RP-HPLC). Both the length and the diameter of the connecting capillaries (150 x 0.020 mm I.D.) as well as the detection volume (3 nl) had to be kept to a minimum in order to maintain the high efficiency of this chromatographic separation system with peak widths at half height in the range of a few seconds. Three different types of frits, namely sintered silica particles, sintered octadecylsilica particles, and monolithic poly(styrene-divinylbenzene) (PS-DVB) frits were evaluated with respect to their influence on chromatographic performance. Best performance for the separation of oligonucleotides and long DNA fragments was observed with the PS-DVB frits, whereas the short DNA fragments were optimally resolved in columns terminated by octadecylsilica frits. The maximum loading capacity of 60 x 0.20 mm I.D. columns ranged from 20 fmol (7.7 ng) for a 587 base pair DNA fragment to 500 fmol (2.4 ng) for a 16-mer oligonucleotide. Lower mass- and concentration detection limits in the low femtomol and low nanomol per liter range, respectively, make capillary IP-RP-HPLC with UV absorbance detection highly attractive for the separation and characterization of minute amounts of synthetic oligonucleotides, DNA restriction fragments, and short tandem repeat sequences amplified by polymerase chain reaction. PMID:11043584

Oberacher, H; Krajete, A; Parson, W; Huber, C G

2000-09-29

125

Catalytic Distillation  

E-print Network

Catalytic Distillation' refers to a chemical process which performs both a catalyzed reaction and primary fractionation of the reaction components simultaneously. A structured catalyst which also is an effective distillation component has been...

Smith, L. A., Jr.; Hearn, D.; Wynegar, D. P.

1984-01-01

126

Repeatability of the efficiency of columns packed with sub-3?m core-shell particles: Part III. 2.7?m Poroshell 120 EC-C18 particles in 4.6mm and 2.1mm × 100mm column formats.  

PubMed

As part of an investigation of the column-to-column repeatability of the efficiency of columns packed with sub-3?m shell particles, the parameters of the mass transfer kinetics of twelve columns packed with the same batch of 2.7?m Poroshell 120 EC-C(18) particles (Agilent Technologies, Little Fall, DE, USA) were sequentially measured, using columns provided by the manufacturers that were representative of the efficiency distribution given by the quality test control. The reduced longitudinal diffusion term (B) was measured using the peak parking (PP) method; the reduced solid-liquid mass transfer resistance term (C) was given by a combination of the PP results and the most accurate model of effective diffusion in ternary composite materials. The overall eddy diffusion term (A) was obtained by subtraction of these two HETP terms from the overall reduced HETP derived from the peak moments measured by numerical integration of the entire peak profiles. The results demonstrate that the dispersion of the column efficiencies is a result of the random nature of the packing process and the eddy diffusion term resulting from the lack of homogeneity of the column bed. At the highest reduced velocity achieved for small analytes, the relative standard deviations (RSD) of the eddy diffusion term for the 2.1mm I.D. columns were ca. 3 and 11% (with average values h(eddy)= 2.5 and 13.5) for naphthalene (k=3) and uracil (k=0), respectively. For the 4.6mm I.D. columns, these RSDs were 5 and 13%, respectively, with average values h(eddy)= 1.4 and 2.9. For insulin at reduced velocities as high as 160, the RSDs of the total reduced plate heights were 3 and 8% for the 2.1 and 4.6mm I.D. columns, respectively. PMID:22683189

Gritti, Fabrice; Guiochon, Georges

2012-08-24

127

Evaluating the interactions of organic compounds with multi-walled carbon nanotubes by self-packed HPLC column and linear solvation energy relationship.  

PubMed

Understanding the interactions between organic pollutants and carbon nanotubes (CNTs) is critical for fate assessment of both CNTs and organic pollutants. In this study, the chromatographic approach was introduced based on CNTs as stationary phase for the evaluation of such interactions. The pristine multi-walled carbon nanotubes (MWCNTs) were packed into columns of high-pressure liquid chromatography (HPLC) and the retention factors (k') were determined to characterize the adsorption affinity of organic compounds onto MWCNTs. Nine compounds were tested. The results showed that their lnk' values followed the order: benzene < toluene < phenol < chlorobenzene < bromobenzene < aniline < sulfamethoxazole < sulfadiazine ? sulfadimidine. The linear solvation energy relationship (LSER) theory was adopted to correlate lnk' with the molecular solvatochromic parameters. We found that lnk' of the studied compounds correlate positively with molecular polarizability (E) significantly, suggesting that the ?-/n-electrons-dependent polarizable interactions play a major role for the adsorption. Moreover, the thermodynamic parameters calculated from van't Hoff equations revealed that the interactions between the compounds and MWCNTs were spontaneous and exothermic processes. PMID:24231331

Chu, Yingqian; Li, Xuehua; Xie, Hongbin; Fu, Zhiqiang; Yang, Xianhai; Qiao, Xianliang; Cai, Xiyun; Chen, Jingwen

2013-12-15

128

C18 silica packed capillary columns with monolithic frits prepared with UV light emitting diode: usefulness in nano-liquid chromatography and capillary electrochromatography.  

PubMed

In this paper the potential of fused silica capillaries packed with RP18 silica particles entrapped with monolithic frits using both nano-liquid chromatography (nano-LC) and capillary electrochromatography (CEC) was investigated. Frits were prepared after removing a short part of the polyimide layer on the capillary wall and irradiating the polymerization mixture with an UV-light emitter diode (LED) at 370 nm. The capillary, was rotated during the polymerization procedure in order to obtain a homogeneous monolith. The distance of the LED from the capillary and the exposure time to UV light were studied in order to obtain frits with good porosity and high robustness. A mixture containing five alkylbenzenes was selected as sample and analyzed by both nano-LC and CEC. The standard mixture was baseline separated with good efficiency in the range 78,000-93,000 and 99,000-113,000 plates/m in nano-LC and CEC, respectively. The columns resulted to be very robust and the prepared monolithic frits allowed working with backpressure as high as 400 bar (nano-LC). In addition high voltages were applied in CEC (25-30 kV) without bubbles formation in absence of pressure assistance during runs. PMID:22189300

D'Orazio, Giovanni; Fanali, Salvatore

2012-04-01

129

Evaluation of monolithic and sub 2 microm particle packed columns for the rapid screening for illicit drugs--application to the determination of drug contamination on Irish euro banknotes.  

PubMed

A study comparing recently available 100 x 3 mm id, 200 x 3 mm id monolithic reversed-phase columns with a 50 x 2.1 mm id, 1.8 microm particle packed reversed-phase columns was carried out to determine the most efficient approach (using traditional van Deemter analysis and a modern kinetic plot approach) for the rapid screening of samples for 16 illicit drugs and associated metabolites. A plot of column backpressure versus plate number (N) showed a significant advantage of using the monolithic phases, with the 20 cm monolithic column exhibiting a maximum 15,000 plates at a column backpressure of approximately 70 bar, compared to approximately 7000 plates at 150 bar for the 5 cm 1.8 microm particle packed column. Optimum linear velocities were found to be 0.40 mm s(-1), 0.52 mm s(-1) and 0.98 mm s(-1) for the three above columns, respectively. The 20 cm monolithic column was subsequently applied to the separation and determination of illicit drug contamination on Irish euro banknotes, using methanol extraction followed by LC-MS/MS. Method performance data showed that the new LC-MS/MS method was significantly more sensitive than previous GC-MS/MS based methods for this application, with detection limits in the pg note(-1) region, based upon a 20 microL standard injection. All of the notes examined tested positive for trace quantities of cocaine, with benzoylecgonine detected on 12 of the 45 notes sampled. Traces of heroin were also detected on three of the 45 notes. PMID:17325753

Bones, Jonathan; Macka, Mirek; Paull, Brett

2007-03-01

130

Distill, Distill_roll Distill for CASP10  

E-print Network

Distill, Distill_roll Distill for CASP10 C. Mirabello1, G. Tradigo1,2 , P.Veltri2, and G. Pollastri and Distill_roll is that for the former we use an improved fold recognition algorithm. Methods Distill runs 3 through 3 searches for Distill_roll (PSSM and SAMD profile against PDB sequences and SAMD, with 3

Pollastri, Gianluca

131

Zenix-C SEC Column User Manual Column Information  

E-print Network

uniform and stable packing bed density for maximum column efficiency. Zenix-C SEC phases are designed1 Zenix-C SEC Column User Manual Column Information Utilizing proprietary surface technologies in high column-to-column reproducibility. The nature of the chemical bonding and the maximum bonding

Lebendiker, Mario

132

Solar Distillation  

Microsoft Academic Search

\\u000a “Solar distillation” is a technology for producing potable water from brackish and underground water of low-quality at low\\u000a cost. It can reduce water-scarcity problems together with other water purification technologies. Solar distillation is analogous\\u000a to natural hydrological cycle. It uses an apparatus called a solar still in which water is evaporated using solar energy,\\u000a a form of renewable energy, and

Rahul Dev; Gopal Nath Tiwari

133

Method for packing chromatographic beds  

DOEpatents

Column chromatography beds are packed through the application of static force. A slurry of the chromatography bed material and a non-viscous liquid is filled into the column plugged at one end, and allowed to settle. The column is transferred to a centrifuge, and centrifuged for a brief period of time to achieve a predetermined packing level, at a range generally of 100-5,000 gravities. Thereafter, the plug is removed, other fixtures may be secured, and the liquid is allowed to flow out through the bed. This results in an evenly packed bed, with no channeling or preferential flow characteristics.

Freeman, David H. (Potomac, MD); Angeles, Rosalie M. (Germantown, MD); Keller, Suzanne (Rockville, MD)

1991-01-01

134

Optimal Control of Distillation Systems  

E-print Network

is therefore the first requirement of optimal control. Use of Slip-Stream Consider the distillation of a binary mixture where one or both components are valuable. are required pure, and are separated in a single column. The objective is to obtain maximum...

Chatterjee, N.; Suchdeo, S. R.

1984-01-01

135

Flow injection solid-phase extraction using multi-walled carbon nanotubes packed micro-column for the determination of polycyclic aromatic hydrocarbons in water by gas chromatography-mass spectrometry.  

PubMed

A flow injection solid-phase extraction preconcentration system using a multi-walled carbon nanotubes (MWCNTs) packed micro-column was developed for the determination of 16 polycyclic aromatic hydrocarbons (PAHs) in water by gas chromatography-mass spectrometry (GC-MS). The preconcentration of PAHs on the MWCNTs was carried out based on the adsorption retention of analytes by on-line introducing the sample into the micro-column system. Methanol was introduced to elute the retained analytes for GC-MS analysis using selected ion monitoring (SIM) mode. Important influence factors were studied in detail, such as sample acidity, sample flow rate, eluent flow rate and volume, dimensions of MWCNTs and amounts of packing material. Limits of detection of 16 PAHs for an extraction of 50 mL water sample were in the range of 0.001-0.15 microg L(-1), and the precisions (RSD) were in the range of 4-14%. The optimized method was successfully applied to the determination of 16 PAHs in surface waters, with recoveries in the range of 72-93% for real spiked sample. PMID:20236647

Wu, Hong; Wang, Xuecui; Liu, Bing; Lu, Jie; Du, Baixiang; Zhang, Luxin; Ji, Jingjing; Yue, Qiaoyu; Han, Baoping

2010-04-23

136

Micro-column preconcentration\\/separation using thiacalix[4]arene tetracarboxylate derivative modified mesoporous TiO 2 as packing materials on-line coupled to inductively coupled plasma optical emission spectrometry for the determination of trace heavy metals in environmental water samples  

Microsoft Academic Search

A novel adsorbent of thiacalix[4]arene tetracarboxylate derivative modified mesoporous TiO2 was prepared and was used as a packing material for flow injection (FI) micro-column (20mm×4.0mm i.d.) separation\\/preconcentration on-line coupled to inductively coupled plasma optical emission spectrometry (ICP-OES) simultaneous determination of trace metals (V, Cu, Pb, Cr) in environmental water samples. The experimental conditions for modified mesoporous TiO2 packed micro-column separation\\/preconcentration

Dahui Chen; Bin Hu; Man He; Chaozhang Huang

2010-01-01

137

Analysis of organic\\/inorganic analytes in environmental samples by packed capillary chromatography  

Microsoft Academic Search

Recent progress in the development of techniques for packing of high efficiency capillary columns has enabled the concept of unified chromatography to be realised. Packed capillary columns offer the advantages of both packed column (high loading capacity, wide range of stationary phases) and capillary column (speed of analysis, high resolution) techniques to produce a versatile and efficient analytical procedure. For

M. D. Burford; M. M. Robson; S. C. Mitchell

1995-01-01

138

Green ultra-fast high-performance liquid chromatographic method using a short narrow-bore column packed with fully porous sub-2 ?m particles for the simultaneous determination of selected pharmaceuticals as surface water and wastewater pollutants.  

PubMed

Fast separations are very desirable in laboratories that analyze large numbers of samples per day or those needing short turn-around times. Traditional HPLC methods using conventional stationary phases and standard column dimensions require significant amounts of organic solvents and generate large volumes of waste. With growing awareness about the environment, the development of green technologies has been receiving increasing attention. In this work, a very fast green analytical method based on LC-UV using a short narrow bore column packed with fully porous sub-2 ?m particles has been developed for simultaneous determination of nine pharmaceuticals in wastewater and surface water. The chromatographic separation was optimized in order to achieve short analysis time and good resolution for all analytes in a single run. All analytes could be separated in 1 min with good resolution. Sample preparation was executed by solid phase extraction using Oasis HLB cartridges. The method developed was validated based on parameters such as linearity, precision, accuracy, detection, and quantification limits. The recovery ranged from 70.9 to 92.5% with SDs not higher than 5.4%, except for acetaminophen and sulphanilamide. LODs ranged from 0.6-2.5 ?g/L, while the LOQs were in the range 2-8 ?g/L. PMID:23229730

Shaaban, Heba; Górecki, Tadeusz

2013-01-01

139

Distillation tray structural parameter study: Phase 1  

NASA Technical Reports Server (NTRS)

The purpose here is to identify the structural parameters (plate thickness, liquid level, beam size, number of beams, tray diameter, etc.) that affect the structural integrity of distillation trays in distillation columns. Once the sensitivity of the trays' dynamic response to these parameters has been established, the designer will be able to use this information to prepare more accurate specifications for the construction of new trays. Information is given on both static and dynamic analysis, modal response, and tray failure details.

Winter, J. Ronald

1991-01-01

140

Photocatalytic degradation of recalcitrant organic pollutants in water using a novel cylindrical multi-column photoreactor packed with TiO2-coated silica gel beads.  

PubMed

A novel cylindrical multi-column photocatalytic reactor (CMCPR) has been developed and successfully applied for the degradation of methyl orange (MO), amoxicillin (AMX) and 3-chlorophenol (3-CP) in water. Due to its higher adsorption capacity and simpler molecular structure, 3-CP compared with MO and AMX obtained the highest photodegradation (100%) and mineralization (78.1%) after 300-min photocatalytic reaction. Electrical energy consumption for photocatalytic degradation of MO, AMX and 3-CP using CMCPR was 5.79×10(4), 7.31×10(4) and 2.52×10(4)kWhm(-3) order(-1), respectively, which were less than one-thousand of those by reported photoreactors. The higher flow rate (15mLmin(-1)), lower initial concentration (5mgL(-1)) and acidic condition (pH 3) were more favorable for the photocatalytic degradation of MO using CMCPR. Five repetitive operations of CMCPR achieved more than 97.0% photodegradation of MO in each cycle and gave a relative standard deviation of 0.72%. In comparison with reported slurry and thin-film photoreactors, CMCPR exhibited higher photocatalytic efficiency, lower energy consumption and better repetitive operation performance for the degradation of MO, AMX and 3-CP in water. The results demonstrated the feasibility of utilizing CMCPR for the degradation of recalcitrant organic pollutants in water. PMID:25528240

Li, Dawei; Zhu, Qi; Han, Chengjie; Yang, Yingnan; Jiang, Weizhong; Zhang, Zhenya

2015-03-21

141

Attachment of Acidithiobacillus ferrooxidans and Leptospirillum ferriphilum cultured under varying conditions to pyrite, chalcopyrite, low-grade ore and quartz in a packed column reactor.  

PubMed

The attachment of Acidithiobacillus ferrooxidans and Leptospirillum ferriphilum spp. grown on ferrous medium or adapted to a pyrite mineral concentrate to four mineral substrata, namely, chalcopyrite and pyrite concentrates, a low-grade chalcopyrite ore (0.5 wt%) and quartzite, was investigated. The quartzite represented a typical gangue mineral and served as a control. The attachment studies were carried out in a novel particle-coated column reactor. The saturated reactor containing glass beads, which were coated with fine mineral concentrates, provided a quantifiable surface area of mineral concentrate and maintained good fluid flow. A. ferrooxidans and Leptospirillum spp. had similar attachment characteristics. Enhanced attachment efficiency occurred with bacteria grown on sulphide minerals relative to those grown on ferrous sulphate in an ore-free environment. Selective attachment to sulphide minerals relative to gangue materials occurred, with mineral adapted cultures attaching to the minerals more efficiently than ferrous grown cultures. Mineral-adapted cultures showed highest levels of attachment to pyrite (74% and 79% attachment for A. ferrooxidans and L. ferriphilum, respectively). This was followed by attachment of mineral-adapted cultures to chalcopyrite (63% and 58% for A. ferrooxidans and L. ferriphilum, respectively). A. ferrooxidans and L. ferriphilum exhibited lower levels of attachment to low-grade ore and quartz relative to the sulphide minerals. PMID:22410741

Africa, Cindy-Jade; van Hille, Robert P; Harrison, Susan T L

2013-02-01

142

Experimental study of multiple steady states in homogeneous azeotropic distillation  

Microsoft Academic Search

Bekiaris et al. (1993) explained the existence of multiple steady states in homogeneous ternary azeotropic distillation, on the basis of the analysis of the case of infinite reflux and infinite column length (infinite number of trays). They showed that the predictions of multiple steady states for such infinite columns have relevant implications for columns of finite length operated at finite

T. E. Guettinger; Cornelius Dorn; Manfred Morari

1997-01-01

143

Distillation sequence for the purification and recovery of hydrocarbons  

DOEpatents

This invention is an improved distillation sequence for the separation and purification of ethylene from a cracked gas. A hydrocarbon feed enters a C2 distributor column. The top of the C2 distributor column is thermally coupled to an ethylene distributor column, and the bottoms liquid of a C2 distributor column feeds a deethanizer column. The C2 distributor column utilizes a conventional reboiler. The top of the ethylene distributor is thermally coupled with a demethanizer column, and the bottoms liquid of the ethylene distributor feeds a C2 splitter column. The ethylene distributor column utilizes a conventional reboiler. The deethanizer and C2 splitter columns are also thermally coupled and operated at a substantially lower pressure than the C2 distributor column, the ethylene distributor column, and the demethanizer column. Alternatively, a hydrocarbon feed enters a deethanizer column. The top of the deethanizer is thermally coupled to an ethylene distributor column, and the ethylene distributor column utilizes a conventional reboiler. The top of the ethylene distributor column is thermally coupled with a demethanizer column, and the bottoms liquid of the ethylene distributor column feeds a C2 splitter column. The C2 splitter column operates at a pressure substantially lower than the ethylene distributor column, the demethanizer column, and the deethanizer column.

Reyneke, Rian (Katy, TX); Foral, Michael (Aurora, IL); Papadopoulos, Christos G. (Naperville, IL); Logsdon, Jeffrey S. (Naperville, IL); Eng, Wayne W. Y. (League City, TX); Lee, Guang-Chung (Houston, TX); Sinclair, Ian (Warrington, GB)

2007-12-25

144

Setting the Pressure at Which to Conduct a Distillation.  

ERIC Educational Resources Information Center

Discusses how pressure setting is determined for distillation columns, examining factors which must be considered when optimizing design for economical balance. Also discusses the basics of heat exchangers and cites a common problem with pressure differences. (JM)

Barduhn, Allen J.

1984-01-01

145

Distillation with Vapour Compression. An Undergraduate Experimental Facility.  

ERIC Educational Resources Information Center

Discusses the need to design distillation columns that are more energy efficient. Describes a "design and build" project completed by two college students aimed at demonstrating the principles of vapour compression distillation in a more energy efficient way. General design specifications are given, along with suggestions for teaching and…

Pritchard, Colin

1986-01-01

146

TOTAL REFLUX OPERATION OF MULTIVESSEL BATCH DISTILLATION  

E-print Network

the operation is switched between total re ux operation and dumping the product i.e., the condenser holdup products are collected in the condenser drum and in the reboiler. Another alternative is to "invert multivessel batch distillation column by calculating in advance the nal holdup in each vessel and then using

Skogestad, Sigurd

147

Application of the self-heat recuperation technology to crude oil distillation  

Microsoft Academic Search

Crude oil distillation is an atmospheric distillation column using a furnace. It consumes about 50% of the energy required in an oil refinery plant. To reduce energy requirements, it is necessary to investigate crude oil distillation and to retrofit it with energy saving processes. Recently, the authors developed an innovative process design technology, termed self-heat recuperation technology for saving energy.

Yasuki Kansha; Akira Kishimoto; Atsushi Tsutsumi

148

Determination of arsenic(III) by flow injection solid phase extraction coupled with on-line hydride generation atomic absorption spectrometry using a PTFE turnings-packed micro-column.  

PubMed

A novel flow injection (FI) solid phase extraction method for the determination of arsenic(III) at trace levels was developed, using on-line hydride generation atomic absorption spectrometry (HG-AAS). Selective determination of As(III) was achieved by on-line formation and retention of the pyrrolidine dithiocarbamate arsenic complex As(III)-PDC on the PTFE turnings which are packed in the preconcentration micro-column. The retained complex was eluted by 2 ml 2 mol l(-1) HCl and subsequently introduced on-line into the integrated reaction chamber/gas-liquid separator (RC-GLS). A 1.5% (m/v) NaBH4 solution was used for arsine generation, while a gas stream of N2 was employed for flash release and transportation towards the atomic absorption flow through cell (AAC) for atomization and measurement. The excellent performance of PTFE turnings as sorbent material and the compact design of the RC-GLS result to high sensitivity, selectivity and sampling frequency. For 60s preconcentration time and sample consumption 10.4 ml a sampling frequency of 25 h(-1) and a detection limit of c(L)=0.02 microg l(-1) were obtained. The repeatability, expressed as relative standard deviation (R.S.D.), at 1.0 microg l(-1) As(III), was s(r)=2.8%. The proposed method was successfully applied to the selective determination of As(III) in natural waters and total arsenic determination in certified reference material. PMID:17723554

Anthemidis, Aristidis N; Martavaltzoglou, Evdoxia K

2006-07-28

149

Two-Dimensional Packing of Short DNA with Non-Pairing Overhangs in Cationic Liposome–DNA Complexes: From Onsager Nematics to Columnar Nematics With Finite-Length Columns  

PubMed Central

We report the formation of liquid crystalline (LC) phases of short double-stranded DNA with non-pairing (non-sticky) overhangs, confined between two-dimensional (2D) lipid bilayers of cationic liposome–DNA complexes. In a landmark study (Science 2007, 318, 1276), Nakata et al. reported on the discovery of strong end-to-end stacking interactions between short DNAs (sDNAs) with blunt ends leading to the formation of 3D nematic (N) and columnar LC phases. Employing synchrotron small-angle X-ray scattering, we have studied the interplay between shape anisotropy-induced and DNA end-to-end interaction-induced N ordering for 11 bp, 24 bp, and 48 bp sDNA rods with single-stranded oligo-thymine (T) overhangs modulating the end-to-end interactions. For suppressed stacking interactions with 10-T overhangs, the volume fraction of sDNA at which the 2D isotropic (I) to N transition occurs for 24 bp and 48 bp sDNA rods depended on their length to width (L/D) shape anisotropy, qualitatively consistent with Onsager's theory for the entropic alignment of rigid rods. As the overhang length is reduced from 10 T to 5 T and 2 T for 24 bp and 48 bp sDNA, the N to I transition occurs at lower volume fractions, indicating the onset of some degree of end-to-end stacking interactions. The 11 bp sDNA rods with 5-T and 10-T overhangs remain in the I phase, consistent with their small shape anisotropy (L/D ? 1.9) below the limit for Onsager LC ordering. Unexpectedly, in contrast to the behavior of 24 bp and 48 bp sDNA, the end-to-end interactions between 11 bp sDNA rods with 2-T overhangs set in dramatically and a novel 2D columnar N phase (NC) with finite-length columns formed. The building blocks of this phase are comprised of 1D stacks of (on average) four 11bp DNA-2T rods with an effective LSTACKED/D ? 8.2. Our findings have implications for the DNA-directed assembly of nanoparticles on 2D platforms via end-to-end interactions and in designing optimally packed LC phases of short anisotropic biomolecules (such as peptides and short-interfering RNAs) on nanoparticle membranes, which are used in gene silencing and chemical delivery. PMID:21520947

Bouxsein, Nathan F.; Leal, Cecília; McAllister, Christopher S.; Ewert, Kai K.; Li, Youli; Samuel, Charles E.; Safinya, Cyrus R.

2011-01-01

150

Analysis of Breakthrough Profiles Based on Gamma Ray Emission Along Loaded Packed Bed Columns: Comparative Evaluation of Ionsiv IE-911 and Chabazite Zeolite for the Removal of Radiostrontium and Cesium from Groundwater  

SciTech Connect

A gamma counting system has been assembled that can profile the breakthrough fronts of gamma-emitting radioisotopes longitudinally and axially along a loaded column. This profiling technique has been particularly useful in columns studies such as those performed with IONSP IE-911, a crystalline silicotitanate (CST) manufactured by UOP, in which unusually long operating times are required to observe cesium breakthrough in column effluent. The length of the mass transfer zone and extent of column saturation can be detected early in a column study by viewing the relative emission of gamma emitters along I the length of the column. In this study, gamma scans were used to analyze loaded CST and zeolite columns used in the treatment of process wastewater simulant and actual groundwater. Results indicate good run-to-run reproductibility in acquiring the scans. The longitudinal gamma scans for both {sup 90}Sr and {sup 137}Cs conformed with breakthrough results reported on the basis of column effluent activity. Although not obvious from data obtained by monitoring effluent activity, the gamma scans indicated that both cesium and strontium in the saturated zone of the CST column are slowly displaced by the higher levels of groundwater cations and are then resorbed further down the column. This displacement phenomenon identified by gamma scans was verified using data from a zeolite column, in which both the gamma scan and column effluent data exhibited radionuclide displacement by groundwater cations. The gamma emission intensities from the CST column runs are used to quantitate and compare the distribution coefficient and loading capacity of {sup 137}Cs on CST versus zeolite.

Bostick, D.T.; DePaoli, S.M.; Lucero, A.J.

1999-10-18

151

Free Boundary Problems in Distillation.  

NASA Astrophysics Data System (ADS)

Design and scaleup of distillation equipment requires an understanding of the vapor-liquid equilibria as well as an understanding of the column hydraulics. This work focuses on two problems of fluid mechanics important in understanding the behavior of distillation columns: the shapes and stability of dielectric drops in an electric field and the flow patterns on distillation trays. Axisymmetric equilibrium shapes and stability of dielectric drops subject to an applied electric field are determined by solving simultaneously the Young-Laplace equation for drop shape and the Maxwell equations for field distribution. Both linearly and nonlinearly polarizable drops are studied, as are drops that are pendant/sessile on a supporting plate and those that are floating freely between two plates. The range of parameters for which hysteresis in drop deformation can be observed is given for linearly and nonlinearly polarizable drops. Properly accounting for the effects of nonlinear polarization brings the theoretical results of this work into accord with previously published experimental results. Detailed examination of the electric fields inside nonlinearly polarizable drops reveals that they are very nonuniform, in contrast to the nearly uniform fields usually found in linearly polarizable drops. The concept of depth averaging the equations of motion for a thin film (relative to the length of the distillation tray) is used to reduce the three-dimensional, free surface flow problem to two dimensions. A one-dimensional model is first used to gain understanding into the behavior of the bulk flow, ignoring any edge effects. A rise in the height profile on the tray, or hydraulic jump, is predicted. The effects of Reynolds number, capillary number (surface tension), tray geometry, and film thickness are all examined. The importance of the downcomers is shown. The two-dimensional model allows examination not only of rectangular trays, but also round trays and trays which are annular arcs, so called "race track" trays. A large zone of recirculation is predicted near the walls of round trays. This is confirmed in published experimental results and in experimental observations reported here. Race track trays did not show recirculation even at large arc angles.

Wohlhuter, Frederick Karl

152

Microwave accelerated steam distillation of essential oil from lavender: A rapid, clean and environmentally friendly approach  

Microsoft Academic Search

A new process design and operation for microwave accelerated steam distillation (MASD) of essential oils was developed. A packed bed of lavender flowers (Lavandula angustifolia Mill., Lamiaceae) sits above the steam source generated by microwave heating. Only steam passes through it without the boiling water mixing with vegetable raw material, as is the case in hydro-distillation. MASD has been compared

F. Chemat; M. E. Lucchesi; J. Smadja; L. Favretto; G. Colnaghi; F. Visinoni

2006-01-01

153

Contact structure for use in catalytic distillation  

DOEpatents

A method for conducting catalytic chemical reactions and fractionation of the reaction mixture comprising feeding reactants into a distillation column reactor contracting said reactant in liquid phase with a fixed bed catalyst in the form of a contact catalyst structure consisting of closed porous containers containing the catatlyst for the reaction and a clip means to hold and support said containers, which are disposed above, i.e., on the distillation trays in the tower. The trays have weir means to provide a liquid level on the trays to substantially cover the containers. In other words, the trays function in their ordinary manner with the addition thereto of the catalyst. The reaction mixture is concurrently fractionated in the column.

Jones, Jr., Edward M. (Friendswood, TX)

1984-01-01

154

Contact structure for use in catalytic distillation  

DOEpatents

A method and apparatus for conducting catalytic chemical reactions and fractionation of the reaction mixture, comprising and feeding reactants into a distillation column reactor contracting said reactant in a liquid phase with a fixed bed catalyst in the form of a contact catalyst structure, consisting of closed porous containers containing the catalyst for the reaction and a clip means to hold and support said containers, which are disposed above, i.e., on the distillation trays in the tower. The trays have weir means to provide a liquid level on the trays to substantially cover the containers. In other words, the trays function in their ordinary manner with the addition thereto of the catalyst. The reaction mixture is concurrently fractionated in the column.

Jones, Jr., Edward M. (Friendswood, TX)

1985-01-01

155

Contact structure for use in catalytic distillation  

DOEpatents

A method and apparatus are disclosed for conducting catalytic chemical reactions and fractionation of the reaction mixture, comprising and feeding reactants into a distillation column reactor contracting said reactant in a liquid phase with a fixed bed catalyst in the form of a contact catalyst structure, consisting of closed porous containers containing the catalyst for the reaction and a clip means to hold and support said containers, which are disposed above, i.e., on the distillation trays in the tower. The trays have weir means to provide a liquid level on the trays to substantially cover the containers. In other words, the trays function in their ordinary manner with the addition thereto of the catalyst. The reaction mixture is concurrently fractionated in the column. 7 figs.

Jones, E.M. Jr.

1985-08-20

156

Contact structure for use in catalytic distillation  

DOEpatents

A method is described for conducting catalytic chemical reactions and fractionation of the reaction mixture comprising feeding reactants into a distillation column reactor, contracting said reactant in liquid phase with a fixed bed catalyst in the form of a contact catalyst structure consisting of closed porous containers containing the catalyst for the reaction and a clip means to hold and support said containers, which are disposed above, i.e., on the distillation trays in the tower. The trays have weir means to provide a liquid level on the trays to substantially cover the containers. In other words, the trays function in their ordinary manner with the addition thereto of the catalyst. The reaction mixture is concurrently fractionated in the column. 7 figs.

Jones, E.M. Jr.

1984-03-27

157

Cryogenic hydrogen isotope distillation for the fusion fuel cycle  

SciTech Connect

Cryogenic distillation is an attractive method for the hydrogen isotopic separations required in fusion fuel cycles. The theoretical and practical aspects of designing and constructing such systems are well established. Practical considerations in the design of systems are presented and applied to the Isotope Separation System (ISS) at the Tritium Systems Test Assembly (TSTA), as well as systems of distillation columns that might be used for a reactor such as the Tokamak Fusion Core Experiment (TFCX) and the recovery of breeding blanket product.

Sherman, R.H.

1985-01-01

158

ANALYSIS OF BREAKTHROUGH PROFILES BASED ON GAMMA-RAY EMISSION ALONG LOADED PACKED BED COLUMNS: COMPARATIVE EVALUATION OF IONSIV IE911 AND CHABAZITE ZEOLITE FOR THE REMOVAL OF RADIOSTRONTIUM AND CESIUM FROM GROUNDWATER  

Microsoft Academic Search

A gamma counting system has been assembled that can profile the breakthrough fronts of gamma-emitting radioisotopes longitudinally along a loaded column. This profiling technique has been particularly useful in column studies such as those performed with IONSIV IE-911, a crystalline silicotitanate (CST) manufactured by UOP, in which long operating times are required to observe cesium effluent breakthrough at the low

S. M. DePaoli; D. T. Bostick; A. J. Lucero

2001-01-01

159

Analysis of Breakthrough Profiles Based on Gamma Ray Emission Along Loaded Packed Bed Columns: Comparative Evaluation of Ionsiv IE911 and Chabazite Zeolite for the Removal of Radiostrontium and Cesium from Groundwater  

Microsoft Academic Search

A gamma counting system has been assembled that can profile the breakthrough fronts of gamma-emitting radioisotopes longitudinally and axially along a loaded column. This profiling technique has been particularly useful in columns studies such as those performed with IONSP IE-911, a crystalline silicotitanate (CST) manufactured by UOP, in which unusually long operating times are required to observe cesium breakthrough in

D. T. Bostick; S. M. DePaoli; A. J. Lucero

1999-01-01

160

Advanced Distillation Final Report  

SciTech Connect

The Advanced Distillation project was concluded on December 31, 2009. This U.S. Department of Energy (DOE) funded project was completed successfully and within budget during a timeline approved by DOE project managers, which included a one year extension to the initial ending date. The subject technology, Microchannel Process Technology (MPT) distillation, was expected to provide both capital and operating cost savings compared to conventional distillation technology. With efforts from Velocys and its project partners, MPT distillation was successfully demonstrated at a laboratory scale and its energy savings potential was calculated. While many objectives established at the beginning of the project were met, the project was only partially successful. At the conclusion, it appears that MPT distillation is not a good fit for the targeted separation of ethane and ethylene in large-scale ethylene production facilities, as greater advantages were seen for smaller scale distillations. Early in the project, work involved flowsheet analyses to discern the economic viability of ethane-ethylene MPT distillation and develop strategies for maximizing its impact on the economics of the process. This study confirmed that through modification to standard operating processes, MPT can enable net energy savings in excess of 20%. This advantage was used by ABB Lumus to determine the potential impact of MPT distillation on the ethane-ethylene market. The study indicated that a substantial market exists if the energy saving could be realized and if installed capital cost of MPT distillation was on par or less than conventional technology. Unfortunately, it was determined that the large number of MPT distillation units needed to perform ethane-ethylene separation for world-scale ethylene facilities, makes the targeted separation a poor fit for the technology in this application at the current state of manufacturing costs. Over the course of the project, distillation experiments were performed with the targeted mixture, ethane-ethylene, as well as with analogous low relative volatility systems: cyclohexane-hexane and cyclopentane-pentane. Devices and test stands were specifically designed for these efforts. Development progressed from experiments and models considering sections of a full scale device to the design, fabrication, and operation of a single-channel distillation unit with integrated heat transfer. Throughout the project, analytical and numerical models and Computational Fluid Dynamics (CFD) simulations were validated with experiments in the process of developing this platform technology. Experimental trials demonstrated steady and controllable distillation for a variety of process conditions. Values of Height-to-an-Equivalent Theoretical Plate (HETP) ranging from less than 0.5 inch to a few inches were experimentally proven, demonstrating a ten-fold performance enhancement relative to conventional distillation. This improvement, while substantial, is not sufficient for MPT distillation to displace very large scale distillation trains. Fortunately, parallel efforts in the area of business development have yielded other applications for MPT distillation, including smaller scale separations that benefit from the flowsheet flexibility offered by the technology. Talks with multiple potential partners are underway. Their outcome will also help determine the path ahead for MPT distillation.

Maddalena Fanelli; Ravi Arora; Annalee Tonkovich; Jennifer Marco; Ed Rode

2010-03-24

161

Datalogging the Distillation Process.  

ERIC Educational Resources Information Center

Presents a distillation experiment that uses temperature sensors connected to a computer in place of thermometers, and enables the whole class to view the data on a monitor and interpret and discuss the data in real time. (JRH)

Soares, Allan; Creevy, Steven

1995-01-01

162

Experimental and Numerical Investigation of Two Dimensional CO2 Adsorption/Desorption in Packed Sorption Beds under Non-Ideal Flows  

NASA Technical Reports Server (NTRS)

The experimental results of CO2 adsorption and desorption in a packed column indicated that the concentration wave front at the center of the packed column differs from those which are close to the wall of column filled with adsorbent material even though the ratio of column diameter to the particle size is greater than 20. The comparison of the experimental results with one dimensional model of packed column shows that in order to simulate the average breakthrough in a packed column a two dimensional (radial and axial) model of packed column is needed. In this paper the mathematical model of a non-slip flow through a packed column with 2 inches in diameter and 18 inches in length filled with 5A zeolite pellets is presented. The comparison of experimental results of CO2 absorption and desorption for the mixed and central breakthrough of the packed column with numerical results is also presented.

Mohamadinejad, H.; Knox, J. C.; Smith, J. E.; Croomes, Scott (Technical Monitor)

2001-01-01

163

[Performance evaluation of three novel biotrickling packings].  

PubMed

Packing is the support medium for microbial adhesion and water retention, and its characteristics are directly related to the removal of pollutants. In the present study, three novel biotrickling packings were developed: polyhedral sphere, burr sphere and polyhedral hollow column. The results showed that the structural characteristics of polyhedral sphere and polyhedral hollow column, with the specific surface area of 200 m2 x m(-3), were better than those of traditional biotrickling packings. The resistance coefficient zeta of polyhedral sphere was almost identical before and after the biofilm formation. Under the same condition, zeta of burr sphere increased much more. Investigations on the start-up time showed that the polyhedral hollow columns could contribute more to the quick biofilm formation. The performance of BTF which was packed with polyhedral sphere was better than the others. When the inlet concentrations of toluene and ethanol were 687.37 and 651.17 mg x m(-3), the removal efficiencies achieved 76.78% and 99.23%, respectively. Biomass measurements showed that the biomass adhering on these packings were more than that on the common polypropylene Bauer ring. Biofilm could be renewed and removed easily from the polyhedral sphere and the pressure drop could maintain at 51.6 Pa x m(-1) at the later stable running phase. However, the pressure drop in the BTF which used burr sphere as the packings increased much more (193.3 Pa x m(-1)), thus causing a clogging phenomenon. PMID:24640905

Mei, Yu; Cheng, Zhuo-Wei; Wang, Jia-De; Huo, Po

2013-12-01

164

40 CFR 721.4500 - Isopropylamine distillation residues and ethylamine distillation residues.  

Code of Federal Regulations, 2010 CFR

... 2010-07-01 false Isopropylamine distillation residues and ethylamine distillation residues. 721.4500 Section 721...Substances § 721.4500 Isopropylamine distillation residues and ethylamine distillation...

2010-07-01

165

40 CFR 721.4500 - Isopropylamine distillation residues and ethylamine distillation residues.  

Code of Federal Regulations, 2011 CFR

... 2011-07-01 false Isopropylamine distillation residues and ethylamine distillation residues. 721.4500 Section 721...Substances § 721.4500 Isopropylamine distillation residues and ethylamine distillation...

2011-07-01

166

Winogradsky Columns  

NSDL National Science Digital Library

This is an exercise about Winogradsky Columns with emphasis placed on the formation and properties of microbial biofilms. It includes background reference material, a field/lab exercise, and several applications. Applications include methods for sampling column layers and a description of how to measure the electro-chemical gradient that develops within the column. Scientific illustrations and images are included as visual references.

Lennox, John; State, Penn

167

Drainage in heterogeneous sand columns with different geometric structures  

Microsoft Academic Search

This paper discusses multi-step drainage experiments in two heterogeneously packed sand columns (10×10×20cm3). Different packing structures were generated using two different sand types. One purpose of the study was to test the influence of packing structures on the movement of water. The second purpose was to assess the quality of predictions for the outflow curves in both columns made with

M. Vasin; P. Lehmann; A. Kaestner; R. Hassanein; W. Nowak; R. Helmig; I. Neuweiler

2008-01-01

168

APPLICATION OF CAPILLARY SUPERCRITICAL FLUID CHROMATOGRAPHY TO THE ANALYSIS OF A MIDDLE DISTILLATE FUEL  

EPA Science Inventory

The paper describes the application of capillary supercritical fluid chromatography (SFC) to the analysis of a middle distillate fuel. Small diameter (50 micrometer i.d.) fused silica capillary columns coated with crosslinked 50% phenyl polymethylsiloxane provided high separation...

169

Reactive Distillation and Air Stripping Processes for Water Recycling and Trace Contaminant Control  

NASA Technical Reports Server (NTRS)

Reactive distillation designs are considered to reduce the presence of volatile organic compounds in the purified water. Reactive distillation integrates a reactor with a distillation column. A review of the literature in this field has revealed a variety of functional reactive columns in industry. Wastewater may be purified by a combination of a reactor and a distiller (e.g., the EWRS or VPCAR concepts) or, in principle, through a design which integrates the reactor with the distiller. A review of the literature in reactive distillation has identified some different designs in such combinations of reactor and distiller. An evaluation of reactive distillation and reactive air stripping is presented with regards to the reduction of volatile organic compounds in the contaminated water and air. Among the methods presented, an architecture is presented for the evaluation of the simultaneous oxidation of organics in air and water. These and other designs are presented in light of potential improvements in power consumptions and air and water purities for architectures which include catalytic activity integrated into the water processor. In particular, catalytic oxidation of organics may be useful as a tool to remove contaminants that more traditional distillation and/or air stripping columns may not remove. A review of the current leading edge at the commercial level and at the research frontier in catalytically active materials is presented. Themes and directions from the engineering developments in catalyst design are presented conceptually in light of developments in the nanoscale chemistry of a variety of catalyst materials.

Boul, Peter J.; Lange, Kevin E.; Conger, Bruce; Anderson, Molly

2009-01-01

170

An exact algorithm for IP column generation  

Microsoft Academic Search

An exact column generation algorithm for integer programs with a large (implicit) number of columns is presented. The family of problems that can be treated includes not only standard partitioning problems such as bin packing and certain vehicle routing problems in which the columns generated have 0–1 compenents and a right-hand side vector of 1's, but also the cutting stock

François Vanderbeck; Laurence A. Wolsey

1996-01-01

171

Miners lamp power pack  

SciTech Connect

A lamp rechargeable dry cell power pack and recharging device therefor is disclosed. The recharging device comprises a socket for receiving the power pack, a plurality of electrodes are presented in the socket and arranged to contact corresponding electrodes on the power pack when it is fully inserted in the socket. The power pack is irregular shaped in cross-section and the socket is correspondingly shaped to receive and support the power pack in only one orientation of the power pack relative to the socket to ensure the registration of the plurality of socket electrodes with corresponding power pack electrodes.

Lane, K.S.

1984-11-06

172

Topological quantum distillation.  

PubMed

We construct a class of topological quantum codes to perform quantum entanglement distillation. These codes implement the whole Clifford group of unitary operations in a fully topological manner and without selective addressing of qubits. This allows us to extend their application also to quantum teleportation, dense coding, and computation with magic states. PMID:17155532

Bombin, H; Martin-Delgado, M A

2006-11-01

173

Chitosan modified ordered mesoporous silica as micro-column packing materials for on-line flow injection-inductively coupled plasma optical emission spectrometry determination of trace heavy metals in environmental water samples  

Microsoft Academic Search

A novel adsorbent of chitosan chemically modified ordered mesoporous silica was synthesized and employed as a solid phase extraction (SPE) material for flow injection (FI) micro-column preconcentration on-line coupled with inductively coupled plasma optical emission spectrometry (ICP-OES) determination of trace heavy metals V, Cu, Pb, Cd and Hg in environmental water samples. The factors affecting separation and preconcentration of target

Dahui Chen; Bin Hu; Chaozhang Huang

2009-01-01

174

27 CFR 27.40 - Distilled spirits.  

Code of Federal Regulations, 2010 CFR

...2010-04-01 2010-04-01 false Distilled spirits. 27.40 Section 27.40 Alcohol...TREASURY LIQUORS IMPORTATION OF DISTILLED SPIRITS, WINES, AND BEER Tax On Imported Distilled Spirits, Wines, and Beer Distilled Spirits...

2010-04-01

175

AMMONIA DISTILLATION FOR DEUTERIUM SEPARATION  

Microsoft Academic Search

The relative volatility or separation factor for deuterium enrichment in ; ammonia distillation was measured at several pressures and deuterium ; concentrations. The knowledge of this ingormation is very helpful in predicting ; costs of heawy water production by the ammonia distillation process. It hss been ; stated by others, that the ammonia distillation process of heawy water production ;

G. T. Petersen; M. Benedict

1960-01-01

176

Microbial activity in weathering columns.  

PubMed

The aim of the present work was to evaluate the metabolic activity of the microbial population associated with a pyritic tailing after a column-weathering test. For this purpose, a column 150cm high and 15cm diameter was used. The solid was a tailing with 63.4% pyrite and with minor amounts of Cu, Pb and Zn sulfides (1.4, 0.5 and 0.8%, respectively). The column model was the habitual one for weathering tests: distilled water was added at the top of the column; the water flowed down through tailings and finally was collected at the bottom for chemical and microbiological analysis. Weathering was maintained for 36 weeks. The results showed a significant presence of microbial life that was distributed selectively over the column: sulfur- and iron-oxidizing aerobic bacteria were in the more oxygenated zone; anaerobic sulfur-reducing bacteria were isolated from the samples taken from the anoxic part of the column. Activity testing showed that (oxidizing and reducing) bacteria populations were active at the end of the weathering test. The quality of the water draining from the column was thus the final product of biological oxidation and reduction promoted by the bacteria consortia. PMID:16949201

García, C; Ballester, A; González, F; Blázquez, M L

2007-03-22

177

Method for making a non-extractable stationary phase of polymer within a capillary column  

DOEpatents

A method is described for coating interior capillary column surfaces, or packing material of a packed column, used for gas chromatography, with a stationary polymer phase that is cross-linked by exposing it to a low-temperature plasma that is uniformly distributed over the column or packing material for a predetermined period of time to effect the desired degree of cross-linking of the coating. 7 figs.

Springston, S.R.

1990-10-30

178

Method for making a non-extractable stationary phase of polymer within a capillary column  

DOEpatents

A method for coating interior capillary column surfaces, or packing material of a packed column, used for gas chromatography, with a stationary polymer phase that is cross-linked by exposing it to a low-temperature plasma that is uniformly distributed over the column or packing material for a predetermined period of time to effect the desired degree of cross-linking of the coating.

Springston, Stephen R. (Middle Island, NY)

1990-01-01

179

Self-regenerating column chromatography  

DOEpatents

The present invention provides a process for treating both cations and anions by using a self-regenerating, multi-ionic exchange resin column system which requires no separate regeneration steps. The process involves alternating ion-exchange chromatography for cations and anions in a multi-ionic exchange column packed with a mixture of cation and anion exchange resins. The multi-ionic mixed-charge resin column works as a multi-function column, capable of independently processing either cationic or anionic exchange, or simultaneously processing both cationic and anionic exchanges. The major advantage offered by the alternating multi-function ion exchange process is the self-regeneration of the resins.

Park, Woo K. (Centerville, OH)

1995-05-30

180

Cascade Distillation System Development  

NASA Technical Reports Server (NTRS)

NASA's Advanced Exploration Systems (AES) Life Support System (LSS) Project is chartered with de-veloping advanced life support systems that will ena-ble NASA human exploration beyond low Earth orbit (LEO). The goal of AES is to increase the affordabil-ity of long-duration life support missions, and to re-duce the risk associated with integrating and infusing new enabling technologies required to ensure mission success. Because of the robust nature of distillation systems, the AES LSS Project is pursuing develop-ment of the Cascade Distillation Subsystem (CDS) as part of its technology portfolio. Currently, the system is being developed into a flight forward Generation 2.0 design.

Callahan, Michael R.; Sargushingh, Miriam; Shull, Sarah

2014-01-01

181

On Discrete Hyperbox Packing  

E-print Network

Bin packing is a very important and popular research area in the computer science field. Past work showed many good and real-world packing algorithms. How- ever, due to the complexity of the problem in multiple-dimensional bin packing, also called...

Li, Xiafeng

2010-01-14

182

Differential Geometry: Circle Packings  

E-print Network

Differential Geometry: Circle Packings [CirclePack, Ken Stephenson] [A Circle Packing Algorithm if it preserves oriented angles. That is, the map sends "tiny" circles to circles. Re Re Re ImImIm f(z)=z2.2 f the curve to the unit disk. #12;Conformal Maps Intuition: Since conformal maps send "tiny" circles

Kazhdan, Michael

183

Systems and methods for reactive distillation with recirculation of light components  

DOEpatents

Systems and methods for producing gas-to-liquids products using reactive distillation are provided. The method for producing gas-to-liquids products can include reacting a feedstock in a column having a distillation zone and a reaction zone to provide a bottoms stream and an overhead stream. A first portion of the overhead stream can be recycled to the column at the top of the reaction zone and second portion of the overhead stream can be recycled to the column at the bottom of the reaction zone.

Stickney, Michael J. (Nassau Bay, TX); Jones, Jr., Edward M. (Friendswood, TX)

2011-07-26

184

Improved Analysis and Understanding of the Petlyuk Distillation Column  

E-print Network

at steady state five degrees of freedom, which may be selected as the following manipulated input variables product specifica- tions we usually have two remaining DOFs when all these specifications are

Skogestad, Sigurd

185

Distillation: The Efficient Workhorse  

E-print Network

aT Possible First glance may show only 3 or 4 utility levels (temperatures) to choose from. These might well be 1000e apart. Some ways to increase the options are: ' multieffect distillation (this spreads the 6T across 2 or 3 towers) use of waste heat...). Cooling below top? Liquid composition Heating above bottom FIG. 3 INTERNED lATE CONDENSER AND REBOILER Plax efficiency Max ett'iclenc)' SO, of heavy 95' of heavy component in component In feed teed 1 condenser r 1 [eboiler 67 20 2 con6ensers r 1...

Steinmeyer, D.

186

A reactive distillation process for a cascade and azeotropic reaction system: Carbonylation of ethanol with dimethyl carbonate  

Microsoft Academic Search

Modelling and simulation of the reactive distillation column have been carried out for the carbonylation process of ethanol with dimethyl carbonate (DMC) producing diethyl carbonate (DEC). As it includes three azeotropes and two cascade reversible reactions with an undesired intermediate, methyl-and-ethyl carbonate (MEC), the reactive distillation is ideally appropriate. Calculations via a robust transient method reveal that a complete DMC

Hu-Ping Luo; Wen-De Xiao

2001-01-01

187

Column Chromatography  

NSDL National Science Digital Library

In this activity, learners separate the components of Gatorade using a home-made affinity column. In doing so, learners model the basic principle of affinity chromatography, a technique used to purify chemicals as well as bio-pharmaceuticals and petroleum products. This resource contains information about affinity chromatography and polarity.

Yu, Julie

2007-01-01

188

Chitosan modified ordered mesoporous silica as micro-column packing materials for on-line flow injection-inductively coupled plasma optical emission spectrometry determination of trace heavy metals in environmental water samples.  

PubMed

A novel adsorbent of chitosan chemically modified ordered mesoporous silica was synthesized and employed as a solid phase extraction (SPE) material for flow injection (FI) micro-column preconcentration on-line coupled with inductively coupled plasma optical emission spectrometry (ICP-OES) determination of trace heavy metals V, Cu, Pb, Cd and Hg in environmental water samples. The factors affecting separation and preconcentration of target heavy metals such as pH, sample flow rate and volume, eluent concentration and volume, interfering ions were investigated. Under the optimized experimental conditions, an enrichment factor of 20 and sampling frequency of 10h(-1) were obtained. The detection limits of the method for V, Cu, Pb, Cd and Hg were 0.33, 0.30, 0.96, 0.05 and 0.93 ng mL(-1), and the relative standard deviations (RSDs) were 2.8%, 6.7%, 1.8%, 4.0% and 5.3% (n=7, C=10 ng mL(-1)), respectively. The adsorption capacities of chitosan modified ordered mesoporous silica for V, Cu, Pb, Cd, and Hg were found to be 16.3, 21.7, 22.9, 12.2 and 13.5 mg g(-1), respectively. In order to validate the developed method, a certified reference material of GSBZ50009-88 environmental water sample was analyzed and the determined values were in good agreement with the certified values. The proposed method has also been applied to the determination of trace heavy metals in natural water samples with satisfactory results. PMID:19203614

Chen, Dahui; Hu, Bin; Huang, Chaozhang

2009-04-30

189

Leaf Pack Network  

NSDL National Science Digital Library

The Leaf Pack Network (LPN) is a network of teachers and students investigating their local stream ecosystems by participating in the leaf pack experiment, which involves creating an artificial leaf pack (dry leaves in a mesh bag), immersing it in a stream for 3-4 weeks, and examining it for signs of aquatic insects as indicators of stream health. Participating classrooms share their data through the internet. This activity highlights the connection between streamside forests and the ecology of rivers and streams.

190

Iterative packing for demand matching and sparse packing.  

SciTech Connect

The main result we will present is a 2k-approximation algorithm for the following 'k-hypergraph demand matching' problem: given a set system with sets of size <=k, where sets have profits & demands and vertices have capacities, find a max-profit subsystem whose demands do not exceed the capacities. The main tool is an iterative way to explicitly build a decomposition of the fractional optimum as 2k times a convex combination of integral solutions. If time permits we'll also show how the approach can be extended to a 3-approximation for 2-column sparse packing. The second result is tight w.r.t the integrality gap, and the first is near-tight as a gap lower bound of 2(k-1+1/k) is known.

Parekh, Ojas

2010-11-01

191

27 CFR 19.301 - Distillation.  

Code of Federal Regulations, 2013 CFR

...ALCOHOL DISTILLED SPIRITS PLANTS Production of Distilled Spirits Rules...through the various steps of production as quickly as plant operation will permit...many distilling or other production operations as...

2013-04-01

192

27 CFR 19.301 - Distillation.  

Code of Federal Regulations, 2011 CFR

...LIQUORS DISTILLED SPIRITS PLANTS Production of Distilled Spirits Rules...through the various steps of production as quickly as plant operation will permit...many distilling or other production operations as...

2011-04-01

193

27 CFR 19.301 - Distillation.  

Code of Federal Regulations, 2012 CFR

...LIQUORS DISTILLED SPIRITS PLANTS Production of Distilled Spirits Rules...through the various steps of production as quickly as plant operation will permit...many distilling or other production operations as...

2012-04-01

194

27 CFR 19.301 - Distillation.  

Code of Federal Regulations, 2014 CFR

...ALCOHOL DISTILLED SPIRITS PLANTS Production of Distilled Spirits Rules...through the various steps of production as quickly as plant operation will permit...many distilling or other production operations as...

2014-04-01

195

27 CFR 19.316 - Distillation.  

Code of Federal Regulations, 2010 CFR

...LIQUORS DISTILLED SPIRITS PLANTS Production § 19.316 Distillation...many distilling or other production operations as desired...through the various steps of production as expeditiously as plant operation will...

2010-04-01

196

27 CFR 24.216 - Distilling material.  

Code of Federal Regulations, 2012 CFR

...material, using any quantity of water desired to facilitate fermentation or distillation. No sugar may be added in the production...material. Distillates containing aldehydes may be used in the fermentation of wine to be used as distilling material. Lees,...

2012-04-01

197

27 CFR 24.216 - Distilling material.  

Code of Federal Regulations, 2013 CFR

...material, using any quantity of water desired to facilitate fermentation or distillation. No sugar may be added in the production...material. Distillates containing aldehydes may be used in the fermentation of wine to be used as distilling material. Lees,...

2013-04-01

198

27 CFR 24.216 - Distilling material.  

Code of Federal Regulations, 2011 CFR

...material, using any quantity of water desired to facilitate fermentation or distillation. No sugar may be added in the production...material. Distillates containing aldehydes may be used in the fermentation of wine to be used as distilling material. Lees,...

2011-04-01

199

27 CFR 24.216 - Distilling material.  

Code of Federal Regulations, 2014 CFR

...material, using any quantity of water desired to facilitate fermentation or distillation. No sugar may be added in the production...material. Distillates containing aldehydes may be used in the fermentation of wine to be used as distilling material. Lees,...

2014-04-01

200

27 CFR 24.216 - Distilling material.  

Code of Federal Regulations, 2010 CFR

...material, using any quantity of water desired to facilitate fermentation or distillation. No sugar may be added in the production...material. Distillates containing aldehydes may be used in the fermentation of wine to be used as distilling material. Lees,...

2010-04-01

201

Analysis of Closed Multivessel Batch Distillation of Ternary Azeotropic Mixtures  

E-print Network

. An indirect level control strategy is implemented that eliminates the need for pre-calculated vessel holdups- posed a closed (total reflux) operation of the conventional batch distillation column with a condenser Condenser D Middle 3 2 1 2 1 x + 12B xF 1N N N D x x x x M xM B N Figure 1: Steadystate compositionprofile

Skogestad, Sigurd

202

Vapor compression distillation module  

NASA Technical Reports Server (NTRS)

A Vapor Compression Distillation (VCD) module was developed and evaluated as part of a Space Station Prototype (SSP) environmental control and life support system. The VCD module includes the waste tankage, pumps, post-treatment cells, automatic controls and fault detection instrumentation. Development problems were encountered with two components: the liquid pumps, and the waste tank and quantity gauge. Peristaltic pumps were selected instead of gear pumps, and a sub-program of materials and design optimization was undertaken leading to a projected life greater than 10,000 hours of continuous operation. A bladder tank was designed and built to contain the waste liquids and deliver it to the processor. A detrimental pressure pattern imposed upon the bladder by a force-operated quantity gauge was corrected by rearranging the force application, and design goals were achieved. System testing has demonstrated that all performance goals have been fulfilled.

Nuccio, P. P.

1975-01-01

203

Zenix SEC Column Manual Column Information  

E-print Network

bed density for maximum column efficiency. Zenix SEC phases are designed to ensure highest resolution1 Zenix SEC Column Manual Column Information Utilizing proprietary surface technologies and 3 m technologies allow the chemistry of thin film formation to be well controlled, which results in high column-to-column

Lebendiker, Mario

204

Contexts for Column Addition and Subtraction  

ERIC Educational Resources Information Center

In this article, the authors discuss their approach to column addition and subtraction algorithms. Adapting an original idea of Paul Cobb and Erna Yackel's from "A Contextual Investigation of Three-Digit Addition and Subtraction" related to packing and unpacking candy in a candy factory, the authors provided an analogous context by designing…

Lopez Fernandez, Jorge M.; Velazquez Estrella, Aileen

2011-01-01

205

Design of the monolithic polymers used in capillary electrochromatography columns  

Microsoft Academic Search

Monolithic columns for capillary electrochromatography (CEC) are receiving quite remarkable attention. Both the simplicity of the in situ preparation and the large number of readily available chemistries make the monolithic separation media a vital alternative to capillary columns packed with particulate materials. This review summarizes the current state-of-the-art in this rapidly growing area of CEC with a focus on monolithic

Frantisek Svec; Eric C. Peters; David Sýkora; Jean M. J. Fréchet

2000-01-01

206

Extraction of protein from distiller’s grain  

Microsoft Academic Search

We have investigated the feasibility of extracting the oil and protein from distiller’s grain (DG) to obtain a higher-valued protein-rich product and a carbohydrate-rich residue better suited for conversion to fermentable sugars. Protein extractions based on aqueous ethanol, alkaline-ethanol, and aqueous enzyme treatments were compared. Three of the methods extracted a significant amount of the protein from dried, defatted DG

Drew J. Cookman; Charles E. Glatz

2009-01-01

207

Non-planar microfabricated gas chromatography column  

DOEpatents

A non-planar microfabricated gas chromatography column comprises a planar substrate having a plurality of through holes, a top lid and a bottom lid bonded to opposite surfaces of the planar substrate, and inlet and outlet ports for injection of a sample gas and elution of separated analytes. A plurality of such planar substrates can be aligned and stacked to provide a longer column length having a small footprint. Furthermore, two or more separate channels can enable multi-channel or multi-dimensional gas chromatography. The through holes preferably have a circular cross section and can be coated with a stationary phase material or packed with a porous packing material. Importantly, uniform stationary phase coatings can be obtained and band broadening can be minimized with the circular channels. A heating or cooling element can be disposed on at least one of the lids to enable temperature programming of the column.

Lewis, Patrick R. (Albuquerque, NM); Wheeler, David R. (Albuquerque, NM)

2007-09-25

208

Packing and stability of geometrically cohesive granular media  

NASA Astrophysics Data System (ADS)

Granular particles with concave shapes may entangle with neighboring particles creating an effective cohesion controlled by particle geometry. We study the packing and stability of vertical columns formed from geometrically cohesive u-shaped particles (staples) of varying barb length, l. We prepare cohesive columns by packing particles in a confining cylindrical tube under vertical vibration at fixed frequency of f = 30 Hz and peak acceleration (in units of g) of ?= 2. The initial and final volume fraction vary with l and volume fraction increases for decreasing l. Once packed, the tube is removed and columns are subjected to vertical vibration at fixed f and variable ?. We monitor column height, h(t), during collapse and find that h(t) is described by a stretched exponential h(t)/h0= [-(t?)^?]. The characteristic collapse time, ?, is governed by an Arrhenius law with ?= ?0(?0/?) where ?0 is a measure of the column's resistance to collapse. We find that ?0 is a non-monotonic function of l and exhibits a maximum at intermediate l. We explain this effect through a model considering packing and entanglement.

Gravish, Nick; Franklin, Scott V.; Hu, David L.; Goldman, Daniel I.

2011-11-01

209

27 CFR 19.307 - Distillates containing extraneous substances.  

Code of Federal Regulations, 2014 CFR

... DISTILLED SPIRITS PLANTS Production of Distilled Spirits...substances. (a) Use in production. Distillates...distilling system before the production gauge and promptly...the distilled spirits plant from which the...

2014-04-01

210

27 CFR 19.307 - Distillates containing extraneous substances.  

Code of Federal Regulations, 2011 CFR

... DISTILLED SPIRITS PLANTS Production of Distilled Spirits...substances. (a) Use in production. Distillates...distilling system before the production gauge and promptly...the distilled spirits plant from which the...

2011-04-01

211

27 CFR 19.307 - Distillates containing extraneous substances.  

Code of Federal Regulations, 2013 CFR

... DISTILLED SPIRITS PLANTS Production of Distilled Spirits...substances. (a) Use in production. Distillates...distilling system before the production gauge and promptly...the distilled spirits plant from which the...

2013-04-01

212

27 CFR 19.307 - Distillates containing extraneous substances.  

Code of Federal Regulations, 2012 CFR

... DISTILLED SPIRITS PLANTS Production of Distilled Spirits...substances. (a) Use in production. Distillates...distilling system before the production gauge and promptly...the distilled spirits plant from which the...

2012-04-01

213

Revamp for more middle distillate  

SciTech Connect

In view of the continued decline in demand for residual fuel oil, the much publicised tightness of refining margins and hence funds for new investment, it is appropriate at this time to review some relatively inexpensive, but well-proven, revamp options that are available to the refiner for increasing yields of mid-distillate products at the expense of fuel oil components. With the partial or complete closure of so much refining capacity, much surplus equipment is available for implementing revamp projects. There is also scope for revamping hitherto moth-balled units and operating them in a manner different from that envisaged during their original design. Some long established conversion processes such as visbreaking and thermal cracking can enjoy a renaissance if demand for distillates remains strong. Mild hydrocracking and distillate dewaxing which are more recent developments in refinery processing can also figure prominently in plans for incremental production of middle distillates.

Weeks, D.J.; Pierce, V.E.

1985-03-01

214

Distillation process using microchannel technology  

DOEpatents

The disclosed invention relates to a distillation process for separating two or more components having different volatilities from a liquid mixture containing the components. The process employs microchannel technology for effecting the distillation and is particularly suitable for conducting difficult separations, such as the separation of ethane from ethylene, wherein the individual components are characterized by having volatilities that are very close to one another.

Tonkovich, Anna Lee (Dublin, OH); Simmons, Wayne W. (Dublin, OH); Silva, Laura J. (Dublin, OH); Qiu, Dongming (Carbondale, IL); Perry, Steven T. (Galloway, OH); Yuschak, Thomas (Dublin, OH); Hickey, Thomas P. (Dublin, OH); Arora, Ravi (Dublin, OH); Smith, Amanda (Galloway, OH); Litt, Robert Dwayne (Westerville, OH); Neagle, Paul (Westerville, OH)

2009-11-03

215

Improved column preparation and performance in capillary electrochromatography  

Microsoft Academic Search

Problems encountered in capillary electrochromatography, i.e. non-reproducible column manufacture, bubble formation during usage, short column lifetimes and limited choice of packing particles are addressed by the development of fritless or single-frit, internally tapered, segmented and dead-volume free coupled capillary columns. The Van Deemter plots measured demonstrate the performance of these high-quality capillaries which are suitable for capillary electrochromatography as well

Erdmann Rapp; Ernst Bayer

2000-01-01

216

Improved column preparation and performance in capillary electrochromatography.  

PubMed

Problems encountered in capillary electrochromatography, i.e. non-reproducible column manufacture, bubble formation during usage, short column lifetimes and limited choice of packing particles are addressed by the development of fritless or single-frit, internally tapered, segmented and dead-volume free coupled capillary columns. The Van Deemter plots measured demonstrate the performance of these high-quality capillaries which are suitable for capillary electrochromatography as well as for capillary high-performance liquid chromatographic applications. PMID:10961327

Rapp, E; Bayer, E

2000-07-28

217

Phytosterol Distribution in Fractions Obtained from Processing of Distillers Dried Grains with Solubles Using Sieving and Elutriation  

Microsoft Academic Search

Cereal Chem. 84(6):626-630 In an earlier study, the combination of sieving and elutriation was effective in separating fiber from distillers dried grains with solubles (DDGS), the coproduct remaining after ethanol production from corn. To separate fiber, air was blown through sieve fractions in an elutriation column. Material carried by air to the top of the elutriation column was the lighter

Radhakrishnan Srinivasan; Robert A. Moreau; Kent D. Rausch; M. E. Tumbleson; Vijay Singh

2007-01-01

218

Solution of systems of columns with energy exchange between recycle streams  

E-print Network

, several examples of systems of fractionating columns in which energy is exchanged between columns are solved by use of the capital theta method of convergence. In this col- umn modular approach, the equations of each unit in the system are solved... by the most appropriate method. Also, the theta method of convergence is generalized to solve distillation columns for which the specifications include the reflux ratio and the boilup ratio. This method is also applied to absorber-type columns. iv...

Haas, Joe Ray

2012-06-07

219

Foam gravel packing  

SciTech Connect

Foam gravel packing experiments run in a fullscale model wellbore demonstrated that foam is a viable alternative to conventional carrier fluids such as water and viscous polymer solutions in select instances. Because of its special characteristics, foam may have advantages over these fluids in completions where low pressure or sensitive formations are encountered. Results from experiments were used to design and implement gravel pack completions in nine shallow, low pressure wells in California. Other wells in the area had a history of lost circulation and washouts during drilling and completion operations using conventional fluids. The foam gravel packs suffered no loss of circulation during placement and proved to be less costly than the conventional slurry packs used in the past.

Elson, T.D.; Anderson, G.W.

1983-03-01

220

Packing Peanut Properties  

NSDL National Science Digital Library

Students work with various types of packing peanuts to investigate states of matter and chemical and physical changes. One of the activities involves making slime. The activities can easily be modified for students with learning disabilities.

Hall, Dori; Hall, Sue

2002-02-02

221

Nasal packing and stenting  

PubMed Central

Nasal packs are indispensable in ENT practice. This study reviews current indications, effectiveness and risks of nasal packs and stents. In endoscopic surgery, nasal packs should always have smooth surfaces to minimize mucosal damage, improve wound healing and increase patient comfort. Functional endoscopic endonasal sinus surgery allows the use of modern nasal packs, since pressure is no longer required. So called hemostatic/resorbable materials are a first step in this direction. However, they may lead to adhesions and foreign body reactions in mucosal membranes. Simple occlusion is an effective method for creating a moist milieu for improved wound healing and avoiding dryness. Stenting of the frontal sinus is recommended if surgery fails to produce a wide, physiologically shaped drainage path that is sufficiently covered by intact tissue. PMID:22073095

Weber, Rainer K.

2011-01-01

222

Distillation and Air Stripping Designs for the Lunar Surface  

NASA Technical Reports Server (NTRS)

Air stripping and distillation are two different gravity-based methods, which may be applied to the purification of wastewater on the lunar base. These gravity-based solutions to water processing are robust physical separation techniques, which may be advantageous to many other techniques for their simplicity in design and operation. The two techniques can be used in conjunction with each other to obtain high purity water. The components and feed compositions for modeling waste water streams are presented in conjunction with the Aspen property system for traditional stage distillation models and air stripping models. While the individual components for each of the waste streams will vary naturally within certain bounds, an analog model for waste water processing is suggested based on typical concentration ranges for these components. Target purity levels for the for recycled water are determined for each individual component based on NASA s required maximum contaminant levels for potable water Distillation processes are modeled separately and in tandem with air stripping to demonstrate the potential effectiveness and utility of these methods in recycling wastewater on the Moon. Optimum parameters such as reflux ratio, feed stage location, and processing rates are determined with respect to the power consumption of the process. Multistage distillation is evaluated for components in wastewater to determine the minimum number of stages necessary for each of 65 components in humidity condensate and urine wastewater mixed streams. Components of the wastewater streams are ranked by Henry s Law Constant and the suitability of air stripping in the purification of wastewater in terms of component removal is evaluated. Scaling factors for distillation and air stripping columns are presented to account for the difference in the lunar gravitation environment. Commercially available distillation and air stripping units which are considered suitable for Exploration Life Support are presented. The advantages to the various designs are summarized with respect to water purity levels, power consumption, and processing rates.

Boul, Peter J.; Lange, Kevin E.; Conger, Bruce; Anderson, Molly

2009-01-01

223

Hydrodynamic flow in capillary-channel fiber columns for liquid chromatography.  

PubMed

The flow characteristics of capillary-channel polymer (C-CP) fiber liquid chromatographic (LC) columns have been investigated. The C-CP fibers are manufactured with eight longitudinal grooves (capillary channels) extending the length of the fibers. Three C-CP fiber examples were studied, with fiber dimensions ranging from approximately 35 microm to 65 microm, and capillary-channel dimensions ranging from approximately 6 microm to 35 microm. The influence of fiber packing density and column inner diameter on peak asymmetry, peak width, and run-to-run reproducibility have been studied for stainless steel LC columns packed with polyester (PET) and polypropylene (PP) C-CP fibers. The van Deemter A-term was evaluated as a function of fiber packing density (approximately 0.3 g/cm(3)-0.75 g/cm(3)) for columns of 4.6 mm inner diameter (i.d.) and at constant packing densities for 1.5 mm, 3.2 mm, 4.6 mm, and 7.7 mm i.d. columns. Although column diameter had little influence on the eluting peak widths, peak asymmetry increased with increasing column diameter. The A-terms for the C-CP fiber packed columns are somewhat larger than current commercial, microparticulate-packed columns, and means for improvement are discussed. Applications in the area of protein (macromolecule) separations appear the most promising at this stage of the system development. PMID:16194542

Stanelle, Rayman D; Sander, Lane C; Marcus, R Kenneth

2005-12-23

224

Comparison of advanced distillation control methods. Third annual report  

SciTech Connect

Detailed dynamic simulations of three industrial distillation columns (a propylene/propane splitter, a xylene/toluene column, and a depropanizer) have been used to study the issue of configuration selection for diagonal PI dual composition controls, feedforward from a feed composition analyzer, and decouplers. Auto Tune Variation (ATV) identification with on-line detuning for setpoint changes was used for tuning the diagonal proportional integral (PI) composition controls. In addition, robustness tests were conducted by inducting reboiler duty upsets. For single composition control, the (L, V) configuration was found to be best. For dual composition control, the optimum configuration changes from one column to another. Moreover, the use of analysis tools, such as RGA, appears to be of little value in identifying the optimum configuration for dual composition control. Using feedforward from a feed composition analyzer and using decouplers are shown to offer significant advantages for certain specific cases.

Riggs, J.B.

1997-07-01

225

Study of electroosmotic flow in packed capillary columns.  

PubMed

The aim of the work was to find the relationship between the structure of the stationary phase and the velocity of the electroosmotic flow (EOF) that it can generate. The attention was paid to the dependence of the electroosmotic mobility (microEOF) on such parameters as: (i) coverage density of a series of specially synthesized C18 stationary phases with/without end-capping, with monomeric/polymeric architecture; (ii) the length of the alkyl chain in the alkylamide (AP) bonded phase (the phases studied were AP with: C1, C5, C6, C7, C8, C12 and C18 alkyl chains) and the effect of the presence of amide and residual amine groups; (iii) the effect of the mobile phase composition on the EOF; (iv) the effect of pH on the EOF. The obtained results have shown that there is no direct relationship between silanol activity (Galushko test) and electroosmotic mobility for C18 phases. The deterioration of the EOF has been observed for AP phases at high pH values. This effect has been attributed to the presence of hydrolytic pillow, which is connected with the sorption of water from hydro-organic mobile phases. PMID:15065790

Szumski, Micha?; Buszewski, Bogus?aw

2004-04-01

226

Bulk stress distributions in the pore space of sphere-packed beds under Darcy flow conditions.  

PubMed

In this paper, bulk stress distributions in the pore space of columns packed with spheres are numerically computed with lattice Boltzmann simulations. Three different ideally packed and one randomly packed configuration of the columns are considered under Darcy flow conditions. The stress distributions change when the packing type changes. In the Darcy regime, the normalized stress distribution for a particular packing type is independent of the pressure difference that drives the flow and presents a common pattern. The three parameter (3P) log-normal distribution is found to describe the stress distributions in the randomly packed beds within statistical accuracy. In addition, the 3P log-normal distribution is still valid when highly porous scaffold geometries rather than sphere beds are examined. It is also shown that the 3P log-normal distribution can describe the bulk stress distribution in consolidated reservoir rocks like Berea sandstone. PMID:24730946

Pham, Ngoc H; Voronov, Roman S; Tummala, Naga Rajesh; Papavassiliou, Dimitrios V

2014-03-01

227

Compartmental modeling of high purity air separation columns  

Microsoft Academic Search

High purity distillation columns are critical unit operations in cryogenic air separation plants. The development of nonlinear control technology is motivated by the need to frequently change production rates in response to time varying utility costs. Detailed column models based on stage-by-stage balance equations are too complex to be incorporated directly into optimization-based strategies such as nonlinear model predictive control.

Shoujun Biana; Suabtragool Khowinij; Michael A. Henson; Paul Belanger; Lawrence Megan

228

Densest binary sphere packings  

NASA Astrophysics Data System (ADS)

The densest binary sphere packings in the ?-x plane of small to large sphere radius ratio ? and small sphere relative concentration x have historically been very difficult to determine. Previous research had led to the prediction that these packings were composed of a few known “alloy” phases including, for example, the AlB2 (hexagonal ?), HgBr2, and AuTe2 structures, and to XYn structures composed of close-packed large spheres with small spheres (in a number ratio of n to 1) in the interstices, e.g., the NaCl packing for n=1. However, utilizing an implementation of the Torquato-Jiao sphere-packing algorithm [Torquato and Jiao, Phys. Rev. EPLEEE81539-375510.1103/PhysRevE.82.061302 82, 061302 (2010)], we have discovered that many more structures appear in the densest packings. For example, while all previously known densest structures were composed of spheres in small to large number ratios of one to one, two to one, and very recently three to one, we have identified densest structures with number ratios of seven to three and five to two. In a recent work [Hopkins , Phys. Rev. Lett.PRLTAO0031-900710.1103/PhysRevLett.107.125501 107, 125501 (2011)], we summarized these findings. In this work, we present the structures of the densest-known packings and provide details about their characteristics. Our findings demonstrate that a broad array of different densest mechanically stable structures consisting of only two types of components can form without any consideration of attractive or anisotropic interactions. In addition, the structures that we have identified may correspond to currently unidentified stable phases of certain binary atomic and molecular systems, particularly at high temperatures and pressures.

Hopkins, Adam B.; Stillinger, Frank H.; Torquato, Salvatore

2012-02-01

229

Radial heterogeneity of some analytical columns used in high-performance liquid chromatography  

SciTech Connect

An on-column electrochemical microdetector was used to determine accurately the radial distribution of the mobile phase velocity and of the column efficiency at the exit of three common analytical columns, namely a 100 mm x 4.6 mm C18 bonded silica-based monolithic column, a 150 mm x 4.6 mm column packed with 2.7 {micro}m porous shell particles of C18 bonded silica (HALO), and a 150 mm x 4.6 mm column packed with 3 {micro}m fully porous C18 bonded silica particles (LUNA). The results obtained demonstrate that all three columns are not radially homogeneous. In all three cases, the efficiency was found to be lower in the wall region of the column than in its core region (the central core with a radius of 1/3 the column inner radius). The decrease in local efficiency from the core to the wall regions was lower in the case of the monolith (ca. 25%) than in that of the two particle-packed columns (ca. 35-50%). The mobile phase velocity was found to be ca. 1.5% higher in the wall than in the core region of the monolithic column while, in contrast, it was ca. 2.5-4.0% lower in the wall region for the two particle-packed columns.

Mriziq, Khaled S [ORNL; Guiochon, Georges A [ORNL

2009-01-01

230

Antioxidant Activity of Phytochemicals from Dried Distillers Grain Oil  

Technology Transfer Automated Retrieval System (TEKTRAN)

A distillate was obtained by molecular distillation of oil extracted from distiller’s dried grains (DDG). The dried distiller’s grains distillate (DDGD) contained phytosterols, steryl ferulates, tocopherols, tocotrienols, and carotenoids. DDGD was tested for its impact on the oxidative stability i...

231

Antioxidant activity of phytochemicals from dried distillers grain oil  

Technology Transfer Automated Retrieval System (TEKTRAN)

A distillate was obtained by molecular distillation of oil extracted from distiller’s dried grains (DDG). The dried distiller’s grains distillate (DDGD) contained phytosterols, steryl ferulates, tocopherols, tocotrienols, and carotenoids. DDGD was tested for its impact on the oxidative stability in...

232

Theory of random packings  

NASA Astrophysics Data System (ADS)

We review a recently proposed theory of random packings. We describe the volume fluctuations in jammed matter through a volume function, amenable to analytical and numerical calculations. We combine an extended statistical mechanics approach `a la Edwards' (where the role traditionally played by the energy and temperature in thermal systems is substituted by the volume and compactivity) with a constraint on mechanical stability imposed by the isostatic condition. We show how such approaches can bring results that can be compared to experiments and allow for an exploitation of the statistical mechanics framework. The key result is the use of a relation between the local Voronoi volume of the constituent grains and the number of neighbors in contact that permits a simple combination of the two approaches to develop a theory of random packings. We predict the density of random loose packing (RLP) and random close packing (RCP) in close agreement with experiments and develop a phase diagram of jammed matter that provides a unifying view of the disordered hard sphere packing problem and further shedding light on a diverse spectrum of data, including the RLP state. Theoretical results are well reproduced by numerical simulations that confirm the essential role played by friction in determining both the RLP and RCP limits. Finally we present an extended discussion on the existence of geometrical and mechanical coordination numbers and how to measure both quantities in experiments and computer simulations.

Song, Chaoming; Wang, Ping; Makse, Hernán A.

2010-05-01

233

Distillation Apparatuses Using Household Items  

NASA Astrophysics Data System (ADS)

A simple apparatus to demonstrate distillation principles can be very difficult to build without the specialty glassware found in chemistry laboratories. We have built inexpensive but effective distillation apparatuses from equipment that can be easily purchased at local department, grocery, or hardware stores. In one apparatus, colored water is heated to boiling and the condensed vapors drip into another container. In another apparatus, acetone is heated to boiling with hot water and the acetone vapors condense onto a Styrofoam cup. The Styrofoam cup is softened by the acetone and collapses. Rubbing alcohol can be used instead of acetone, but the cup is not softened and the boiling point is much higher. Both apparatuses can be used in a classroom. Both are simple, cost-effective ways of demonstrating distillation, evaporation, and condensation. They would be ideal to use in elementary and middle school classrooms when explaining these concepts.

Campanizzi, Danielle R. D.; Mason, Brenda; Hermann, Christine K. F.

1999-08-01

234

Solar power water distillation unit  

NASA Astrophysics Data System (ADS)

Clean drinking water is the basic necessity for every human being, but about 1.1 billion people in the world lacked proper drinking water. There are many different types of water purification processes such as filtration, reverse osmosis, ultraviolet radiation, carbon absorption, but the most reliable processes are distillation and boiling. Water purification, such as distillation, is especially important in regions where water resources or tap water is not suitable for ingesting without boiling or chemical treatment. In design project It treats the water by combining different methods such as Filtration, Distillation and a technique called concentrated solar power (CSP). Distillation is literally the method seen in nature, whereby: the sun heats the water on the earth's surface, the water is turned into a vapor (evaporation) and rises, leaving contaminants behind, to form clouds. As the upper atmosphere drops in temperature the vapors cool and convert back to water to form water. In this project distillation is achieved by using a parabolic mirror which boils water at high temperature. Filtration is done by sand filter and carbon filter. First sand filter catches the sand particles and the carbon filter which has granules of active carbon is used to remove odor dissolved gases from water. This is the Pre-treatment of water. The filtered water is then collected in a water container at a focus of parabolic mirror where distillation process is done. Another important feature of designed project is the solar tracking of a parabolic mirror which increases the efficiency of a parabolic mirror [1],[2].

Hameed, Kamran; Muzammil Khan, Muhammad; Shahrukh Ateeq, Ijlal; Omair, Syed Muhammad; Ahmer, Muhammad; Wajid, Abdul

2013-06-01

235

Continuous synthesis of lauroyl or oleoyl erythritol by a packed-bed reactor with an immobilized lipase  

Microsoft Academic Search

A system is proposed for the continuous synthesis of an acyl erythritol through the immobilised-lipase-catalysed condensation of the corresponding fatty acid and erythritol in acetone. A fatty acid dissolved in acetone was fed to a column packed with erythritol powders, and erythritol was dissolved in the column at a saturated concentration. The effluent from the column was introduced to a

Junkui Piao; Takashi Kobayashi; Shuji Adachi; Kazuhiro Nakanishi; Ryuichi Matsuno

2004-01-01

236

Extended testing of compression distillation.  

NASA Technical Reports Server (NTRS)

During the past eight years, the NASA Manned Spacecraft Center has supported the development of an integrated water and waste management system which includes the compression distillation process for recovering useable water from urine, urinal flush water, humidity condensate, commode flush water, and concentrated wash water. This paper describes the design of the compression distillation unit, developed for this system, and the testing performed to demonstrate its reliability and performance. In addition, this paper summarizes the work performed on pretreatment and post-treatment processes, to assure the recovery of sterile potable water from urine and treated urinal flush water.

Bambenek, R. A.; Nuccio, P. P.

1972-01-01

237

Solar distillation of sea water  

SciTech Connect

Indian coastal and fishing villages suffer from scarcity of potable water. Solar distillation could provide a solution to this problem by adopting the following criteria: (1) Integration of distillation and storage systems with the house design. (2) Public supply of sea water and a public drain pipe system to periodically drain away the concentrated brine. (3) Harvest and store rain water to tide over cloudy rainy periods. In India there has been a thrust towards centralized non-conventional energy systems. Decentralized non-conventional energy devices and centralized service support units may offer a better solution. 1 fig.

Subramanyam, S. (Kakatiya Institute of Technology and Science, Warangal (India))

1989-01-01

238

Distillation of hydrogen isotopes for polarized HD target  

E-print Network

We have developed a cryogenic distillation system to purify Hydrogen-Deuteride (HD) gas for a polarized HD target in LEPS experiments at SPring-8. A small amount of ortho-H$_2$ ($\\sim$0.01%) in the HD gas plays an important role in efficiently polarizing the HD target. Since there are 1$\\sim$5% impurities of H$_2$ and D$_2$ in commercially available HD gases, it is inevitable that the HD gas is purified up to $\\sim$99.99%. The distillation system has a cryogenic pot (17$\\sim$21 K) containing many small stainless steel cells called Heli-pack. Commercial HD gas with an amount of 5.2 mol is fed into the pot. We carried out three distillation runs by changing temperatures (17.5 K and 20.5 K) and gas extraction speeds (1.3 ml/min and 5.2 ml/min). The extracted gas was analyzed by using a gas analyzer system combining a quadrupole mass spectrometer with a gas chromatograph. The HD gas of 1 mol with a purity better than 99.99% has been successfully obtained. The effective NTS (Number of Theoretical Stages), which is...

Ohta, T; Didelez, J -P; Fujiwara, M; Fukuda, K; Kohri, H; Kunimatsu, T; Morisaki, C; Ono, S; Rouill', G; Tanaka, M; Ueda, K; Uraki, M; Utsuro, M; Wang, S Y; Yosoi, M

2011-01-01

239

Comparison of batch and column methods for assessing leachability of hazardous waste  

Microsoft Academic Search

Inorganic and organic analytes were leached from four waste samples by using batch and column leaching methods. Waste samples were electroplating sludge, fly ash, filter cake, and polystill bottoms. Leachate concentration profiles were constructed from sequential leaching of waste with distilled deionized water using a combined solution to waste ratio of 40:1. Leachate profiles produced by the batch and column

Danny R. Jackson; Benjamin C. Garrett; Thomas A. Bishop

1984-01-01

240

Energy Recovery in Industrial Distillation Processes  

E-print Network

ENERGY RECOVERY IN INDUSTRIAL DISTILLATION PROCESSES Duane B. Paul General Electric Company Fitchburg, Massachusetts ABSTRACT Overhead separati on processes whi ch present attracti ve Distillation processes are energy intensive Condenser...

Paul, D. B.

1983-01-01

241

Properties of Distillers Grains Composites  

Technology Transfer Automated Retrieval System (TEKTRAN)

Interest in renewable biofuel sources has intensified in recent years, leading to greatly increased production of ethanol and its primary coproduct, Distillers Dried Grain with Solubles (DDGS). Consequently, the development of new outlets for DDGS has become crucial to maintaining the economic viab...

242

Corrosion inhibition for distillation apparatus  

DOEpatents

Tower material corrosion in an atmospheric or sub-atmospheric distillation tower in a coal liquefaction process is reduced or eliminated by subjecting chloride-containing tray contents to an appropriate ion-exchange resin to remove chloride from such tray contents materials.

Baumert, Kenneth L. (Emmaus, PA); Sagues, Alberto A. (Lexington, KY); Davis, Burtron H. (Georgetown, KY); Schweighardt, Frank K. (Upper Macungie, PA)

1985-01-01

243

Contextual Reasoning Distilled M. Benerecetti  

E-print Network

Contextual Reasoning Distilled M. Benerecetti , P. Bouquet , and C. Ghidini ¡ ¢ Dip. di Chester Street, Manchester M1 5GD, U.K. Phone number: +44 (0)161 247 1556 C.Ghidini@doc.mmu.ac.uk Abstract can be traced back to R. Weyhrauch and his work on mechanising logical theories in the interactive

Bouquet, Paolo

244

Purifying Aluminum by Vacuum Distillation  

NASA Technical Reports Server (NTRS)

Proposed method for purifying aluminum employs one-step vacuum distillation. Raw material for process impure aluminum produced in electrolysis of aluminum ore. Impure metal melted in vacuum. Since aluminum has much higher vapor pressure than other constituents, boils off and condenses on nearby cold surfaces in proportions much greater than those of other constituents.

Du Fresne, E. R.

1985-01-01

245

Nutrition Action Pack.  

ERIC Educational Resources Information Center

One of five McDonald's Action Packs, these instructional materials integrate elementary school-level nutrition education into other disciplines--biology, sociology, physiology, mathematics, and art. Contents include four units consisting of twelve activities. Unit 1, Why You Need Food, is a self-examination of what is needed for growth, health,…

Sockut, Joanne; Stumpe, Stephanie

246

Find Your Pack  

NSDL National Science Digital Library

This activity introduces learners to wolf behavior and communication. Learners explore how wolves communicate with each other by using their sense of smell to identify members of their "pack." Activity also includes suggestions for connecting this activity to a discussion of how habitat loss can affect wolf populations.

Eduweb

2012-01-01

247

Packing Them In.  

ERIC Educational Resources Information Center

This activity involves students investigating the mathematics of packaging and exploring various concepts in geometry, including area and the Pythagorean theorem. Mathematics comes out of the discussion of packaging cans into six-packs and focuses on the cost-effectiveness of the horizontal storage area used. Students learn how knowledge of…

Carter, Claudia

1997-01-01

248

DIY Fraction Pack.  

ERIC Educational Resources Information Center

Describes a very successful attempt to teach fractions to year 5 pupils based on pupils making their own fraction pack. Children decided for themselves how to make the fractional slices used in the activity using colored cardboard sheets and templates of a paper circle consisting of 24 equal slices. (Author/NB)

Graham, Alan; Graham, Louise

2003-01-01

249

Cadmium removal in a biosorption column  

Microsoft Academic Search

New biosorbent material derived from a ubiquitous brown marine alga Ascophyllum nodosum has been examined in packed-bed flow-through sorption columns. It effectively removed 10 mg\\/L of cadmium down to 1.5 ppb levels in the effluent, representing 99.985% removal. The experimental methodology used was based on the early Bohart and Adams sorption model, resulting in quantitative determination of the characteristic process

B. Volesky; I. Prasetyo

1994-01-01

250

27 CFR 19.322 - Distillates containing extraneous substances.  

Code of Federal Regulations, 2010 CFR

... DISTILLED SPIRITS PLANTS Production § 19.322 Distillates...system prior to the production gauge for addition...the distilled spirits plant from which the distillates...spirits for use in wine production and the receipt...

2010-04-01

251

27 CFR 1.91 - Bottled distilled spirits.  

Code of Federal Regulations, 2010 CFR

...2010-04-01 false Bottled distilled spirits. 1.91 Section 1.91 Alcohol...ADMINISTRATION ACT, NONINDUSTRIAL USE OF DISTILLED SPIRITS AND WINE, BULK SALES AND BOTTLING OF DISTILLED SPIRITS Bulk Sales and Bottling of Distilled...

2010-04-01

252

21 CFR 184.1848 - Starter distillate.  

Code of Federal Regulations, 2011 CFR

...Starter distillate (butter starter distillate) is a steam distillate of the culture of any or all of the following species of bacteria grown on a medium consisting of skim milk usually fortified with about 0.1 percent citric acid: Streptococcus...

2011-04-01

253

Oil recovery from condensed corn distillers solubles  

Microsoft Academic Search

Condensed corn distillers solubles (CCDS) contains more oil than dried distillers grains with solubles (DDGS), 20 vs. 12% (dry weight basis). Therefore, significant amount of oil is present in the liquid fraction after fermentation and ethanol distillation. The oil removed represents a significant alternative feedstock for biodiesel production. The objectives of the present research were to study the effect of

Sandra Majoni

2009-01-01

254

Distillation of hydrogen isotopes for polarized HD target  

E-print Network

We have developed a cryogenic distillation system to purify Hydrogen-Deuteride (HD) gas for a polarized HD target in LEPS experiments at SPring-8. A small amount of ortho-H$_2$ ($\\sim$0.01%) in the HD gas plays an important role in efficiently polarizing the HD target. Since there are 1$\\sim$5% impurities of H$_2$ and D$_2$ in commercially available HD gases, it is inevitable that the HD gas is purified up to $\\sim$99.99%. The distillation system has a cryogenic pot (17$\\sim$21 K) containing many small stainless steel cells called Heli-pack. Commercial HD gas with an amount of 5.2 mol is fed into the pot. We carried out three distillation runs by changing temperatures (17.5 K and 20.5 K) and gas extraction speeds (1.3 ml/min and 5.2 ml/min). The extracted gas was analyzed by using a gas analyzer system combining a quadrupole mass spectrometer with a gas chromatograph. The HD gas of 1 mol with a purity better than 99.99% has been successfully obtained. The effective NTS (Number of Theoretical Stages), which is an indicator of the distillator performances, is obtained as 37.2$\\pm$0.6. This value is in reasonable agreement with a designed value of 37.9. The HD target is expected to be efficiently polarized under a well-controlled condition by doping an optimal amount of ortho-H$_2$ to the purified HD gas.

T. Ohta; S. Bouchigny; J. -P. Didelez; M. Fujiwara; K. Fukuda; H. Kohri; T. Kunimatsu; C. Morisaki; S. Ono; G. Rouill'; M. Tanaka; K. Ueda; M. Uraki; M. Utsuro; S. Y. Wang; M. Yosoi

2011-12-12

255

Optimization of blended battery packs  

E-print Network

This thesis reviews the traditional battery pack design process for hybrid and electric vehicles, and presents a dynamic programming (DP) based algorithm that eases the process of cell selection and pack design, especially ...

Erb, Dylan C. (Dylan Charles)

2013-01-01

256

Intermediate Vapor Expansion Distillation and Nested Enrichment Cascade Distillation  

E-print Network

is described in three configurations overhead vapor compresed, bottoms vapor compressed, or completely closed cycle. As with conventional cascades, conventional heat pumping does to increase the distillation efficiency. Heat pumping merely substitutes...) from overhead to interreboiler; 2) from intercondenser to bottoms reboilerj or 3) from intercondenser to interreboiler. Also, the vapor being compressed can be overhead vapor, bottoms vapor, or a separate closed cycle vapor. Thus there are nine...

Erickson, D. C.

257

Fate of pesticides in a distilled spirit of barley shochu during the distillation process.  

PubMed

Moromi (the fermented mash) of "mugi shochu" that had been artificially contaminated with pesticides was distilled to elucidate the fate of pesticides in the distillation process. The pesticides residing in the distillate were quantified by liquid chromatography-tandem mass spectrometry (LC-MS/MS). Of the analyzed pesticides (249 compounds), 89% were not detected in the distillate, showing that the distillation process minimized the risk of pesticide contamination. PMID:21150108

Inoue, Tomonori; Nagatomi, Yasushi; Kinami, Tomohisa; Uyama, Atsuo; Mochizuki, Naoki

2010-01-01

258

The fate of mycotoxins during the distillation process of barley shochu, a distilled alcoholic beverage.  

PubMed

Mycotoxins are frequent contaminants of grains and critical risk substances for brewers. Fermented barley mash contaminated artificially with 13 representative mycotoxins was distilled with small-scale apparatuses to elucidate the possibility of mycotoxin transfer from mash to distillates. None of these were detected in the distillates. The distillation process can effectively reduce the contamination risk posed by mycotoxins in distilled alcoholic beverages. PMID:22232264

Nagatomi, Yasushi; Inoue, Tomonori; Uyama, Atsuo; Mochizuki, Naoki

2012-01-01

259

Cascade Distillation Subsystem Development: Progress Toward a Distillation Comparison Test  

NASA Technical Reports Server (NTRS)

Recovery of potable water from wastewater is essential for the success of long-duration manned missions to the Moon and Mars. Honeywell International and a team from NASA Johnson Space Center (JSC) are developing a wastewater processing subsystem that is based on centrifugal vacuum distillation. The wastewater processor, referred to as the Cascade Distillation Subsystem (CDS), utilizes an innovative and efficient multistage thermodynamic process to produce purified water. The rotary centrifugal design of the system also provides gas/liquid phase separation and liquid transport under microgravity conditions. A five-stage subsystem unit has been designed, built, delivered and integrated into the NASA JSC Advanced Water Recovery Systems Development Facility for performance testing. A major test objective of the project is to demonstrate the advancement of the CDS technology from the breadboard level to a subsystem level unit. An initial round of CDS performance testing was completed in fiscal year (FY) 2008. Based on FY08 testing, the system is now in development to support an Exploration Life Support (ELS) Project distillation comparison test expected to begin in early 2009. As part of the project objectives planned for FY09, the system will be reconfigured to support the ELS comparison test. The CDS will then be challenged with a series of human-gene-rated waste streams representative of those anticipated for a lunar outpost. This paper provides a description of the CDS technology, a status of the current project activities, and data on the system s performance to date.

Callahan, M. R.; Lubman, A.; Pickering, Karen D.

2009-01-01

260

Computer simulations of particle packing  

Microsoft Academic Search

Computer code has been developed to rapidly simulate the random packing of disks and spheres in two and three dimensions. Any size distribution may be packed. The code simulates varying degrees of inter particle conditions ranging from sticky to free flowing. The code will also calculate the overall packing density, density distributions, and void size distributions (in two dimensions). An

J. Cesarano; M. J. McEuen; T. Swiler

1996-01-01

261

Enabling Microliquid Chromatography by Microbead Packing of Microchannels  

NASA Technical Reports Server (NTRS)

The microbead packing is the critical element required in the success of on-chip microfabrication of critical microfluidic components for in-situ analysis and detection of chiral amino acids. In order for microliquid chromatography to occur, there must be a stationary phase medium within the microchannel that interacts with the analytes present within flowing fluid. The stationary phase media are the microbeads packed by the process discussed in this work. The purpose of the microliquid chromatography is to provide a lightweight, low-volume, and low-power element to separate amino acids and their chiral partners efficiently to understand better the origin of life. In order to densely pack microbeads into the microchannels, a liquid slurry of microbeads was created. Microbeads were extracted from a commercially available high-performance liquid chromatography column. The silica beads extracted were 5 microns in diameter, and had surface coating of phenyl-hexyl. These microbeads were mixed with a 200- proof ethanol solution to create a microbead slurry with the right viscosity for packing. A microfilter is placed at the outlet via of the microchannel and the slurry is injected, then withdrawn across a filter using modified syringes. After each injection, the channel is flushed with ethanol to enhance packing. This cycle is repeated numerous times to allow for a tightly packed channel of microbeads. Typical microbead packing occurs in the macroscale into tubes or channels by using highly pressurized systems. Moreover, these channels are typically long and straight without any turns or curves. On the other hand, this method of microbead packing is completed within a microchannel 75 micrometers in diameter. Moreover, the microbead packing is completed into a serpentine type microchannel, such that it maximizes microchannel length within a microchip. Doing so enhances the interactions of the analytes with the microbeads to separate efficiently amino acids and amino acid enantiomers.

Balvin, Manuel; Zheng, Yun

2013-01-01

262

Enabling Microliquid Chromatography by Microbead Packing of Microchannels  

NASA Technical Reports Server (NTRS)

The microbead packing is the critical element required in the success of on-chip microfabrication of critical microfluidic components for in-situ analysis and detection of chiral amino acids. In order for microliquid chromatography to occur, there must be a stationary phase medium within the microchannel that interacts with the analytes present within flowing fluid. The stationary phase media are the microbeads packed by the process discussed in this work. The purpose of the microliquid chromatography is to provide a lightweight, low-volume, and low-power element to separate amino acids and their chiral partners efficiently to understand better the origin of life. In order to densely pack microbeads into the microchannels, a liquid slurry of microbeads was created. Microbeads were extracted from a commercially available high-performance liquid chromatography column. The silica beads extracted were 5 microns in diameter, and had surface coating of phenyl-hexyl. These microbeads were mixed with a 200- proof ethanol solution to create a microbead slurry with the right viscosity for packing. A microfilter is placed at the outlet via of the microchannel and the slurry is injected, then withdrawn across a filter using modified syringes. After each injection, the channel is flushed with ethanol to enhance packing. This cycle is repeated numerous times to allow for a tightly packed channel of microbeads. Typical microbead packing occurs in the macroscale into tubes or channels by using highly pressurized systems. Moreover, these channels are typically long and straight without any turns or curves. On the other hand, this method of microbead packing is completed within a microchannel 75 micrometers in diameter. Moreover, the microbead packing is completed into a serpentine type microchannel, such that it maximizes microchannel length within a microchip. Doing so enhances the interactions of the analytes with the microbeads to separate efficiently amino acids and amino acid enantiomers.

Balvin, Manuel; Zheng, Yun

2014-01-01

263

Drainage in heterogeneous sand columns with different geometric structures  

NASA Astrophysics Data System (ADS)

This paper discusses multi-step drainage experiments in two heterogeneously packed sand columns (10 × 10 × 20 cm 3). Different packing structures were generated using two different sand types. One purpose of the study was to test the influence of packing structures on the movement of water. The second purpose was to assess the quality of predictions for the outflow curves in both columns made with an upscaled model. The heterogeneous structures of the columns can be considered as two opposing extremes. The first column was packed with a random arrangement of two sand types that is not stochastically homogeneous and where a cluster running through the column exists for both materials. The second column was packed with a periodic pattern of coarse-sand inclusions in a fine-sand background and has a clearly defined unit cell. The depth-averaged (2D) spatial distribution of the water content in the columns was monitored during the whole multi-step outflow experiment using neutron radiography. The 3D water content was measured at the steady states by neutron tomography. The experimental results are compared with the model predictions of an upscaled model derived with the homogenization theory. The parameters for the upscaled model are calculated from the hydraulic parameters of the two sand types. These hydraulic parameters were first identified in independent measurements on samples of the two individual sand types, separately. Additionally, the hydraulic parameters of both sands were identified by fitting a numerical model to the measured outflow curves. The different column structures showed a significant effect on water retention and the effective retention function, as water was trapped in the coarse-sand inclusions of the periodic structure. We included this trapping effect in the effective retention function of the upscaled model with an apparent air entry pressure. Contrary to the retention, the different packing structures had no large effect on the dynamic behavior of the outflow. The effective conductivity of the columns is therefore not significantly influenced by the structure. The upscaled models predicted the movement of the averaged water content in the two columns well. This confirms the applicability of upscaled models even if the underlying requirements are not strictly met.

Vasin, M.; Lehmann, P.; Kaestner, A.; Hassanein, R.; Nowak, W.; Helmig, R.; Neuweiler, I.

2008-09-01

264

C-Store: A Column-oriented DBMS  

Microsoft Academic Search

This paper presents the design of a read-optimized relational DBMS that contrasts sharply with most current systems, which are write-optimized. Among the many differences in its design are: storage of data by column rather than by row, careful coding and packing of objects into storage including main memory during query processing, storing an overlapping collection of column-oriented projections, rather than

Michael Stonebraker; Daniel J. Abadi; Adam Batkin; Xuedong Chen; Mitch Cherniack; Miguel Ferreira; Edmond Lau; Amerson Lin; Samuel Madden; Elizabeth J. O'Neil; Patrick E. O'Neil; Alex Rasin; Nga Tran

2005-01-01

265

Drainage Experiments in Heterogeneous Sand Columns With Different Geometric Structures  

NASA Astrophysics Data System (ADS)

This poster presents results of multi-step drainage experiments, carried out with two sand columns (10x10x20 cm3) packed with different structures made up from two different sand types. One purpose was to test the influence of the column structure on the movement of the water during drainage. The second purpose was to test upscaled models for the prediction of outflow curves, even when the underlying assumptions on soil structure are not met. The two packing structures used in the experiments can be considered as two opposing extremes. The packing of the columns was made of 1x1x1 cm3 cubes of the two sand types. The first column was packed with a periodic pattern of coarse material inclusions in a fine-material background, having a clearly defined macroscopic representative elementary volume. The second column was packed with a random arrangement of the sand types that has no typical length scale smaller than that one of the column and where fine and coarse materials formed column spanning connected clusters. The depth averaged two-dimensional spatial distribution of the water content in the columns was monitored during the drainage using neutron radiography. A three dimensional tomogram of the water content was measured at steady state after each pressure step. When comparing the results from the two columns, we found that due to trapping effects the different distributions of isolated structures had an effect on the retention of drainage, indicating a significant influence of structure at effective retention curve. In contrast to the retention curve, the effective conductivity of the columns was not significantly influenced by the structure. We compared the experimental results to an upscaled model derived from homogenization theory (for slow flow processes and capillary dominated flow). It has the same form as the Richards equation with an effective retention function and an effective unsaturated hydraulic conductivity function. The hydraulic parameters of the coarse and the fine sand have been defined by least square fitting of to the measured retention curves and by fitting to the outflow curves using a Levenberg Marquardt algorithm. The hydraulic parameters were used as input to the upscaling procedure. We included the effect of structure on retention by using adapted upscaled retention curves, which consider the accessability of inclusion material to air during drainage. The upscaled models predicted the movement of the averaged water content in the two columns well. This can be considered to confirm the applicability of upscaled models even if the underlying requirements are not strictly met.

Vasin, M.; Lehmann, P.; Nowak, W.; Hassanein, R.; Neuweiler, I.

2007-12-01

266

Five points on columns  

E-print Network

Column,” like “gene,” has both conceptual and linguistic shortcomings. The simple question “what is a column” is not easy to answer and the word itself is not easy to replace. In the present article, I have selected five ...

Rockland, Kathleen

267

Vapor Compression Distillation Flight Experiment  

NASA Technical Reports Server (NTRS)

One of the major requirements associated with operating the International Space Station is the transportation -- space shuttle and Russian Progress spacecraft launches - necessary to re-supply station crews with food and water. The Vapor Compression Distillation (VCD) Flight Experiment, managed by NASA's Marshall Space Flight Center in Huntsville, Ala., is a full-scale demonstration of technology being developed to recycle crewmember urine and wastewater aboard the International Space Station and thereby reduce the amount of water that must be re-supplied. Based on results of the VCD Flight Experiment, an operational urine processor will be installed in Node 3 of the space station in 2005.

Hutchens, Cindy F.

2002-01-01

268

Heat Transfer Analysis for a Fixed CST Column  

SciTech Connect

In support of a small column ion exchange (SCIX) process for the Savannah River Site waste processing program, a transient two-dimensional heat transfer model that includes the conduction process neglecting the convection cooling mechanism inside the crystalline silicotitanate (CST) column has been constructed and heat transfer calculations made for the present design configurations. For this situation, a no process flow condition through the column was assumed as one of the reference conditions for the simulation of a loss-of-flow accident. A series of the modeling calculations has been performed using a computational heat transfer approach. Results for the baseline model indicate that transit times to reach 130 degrees Celsius maximum temperature of the CST-salt solution column are about 96 hours when the 20-in CST column with 300 Ci/liter heat generation source and 25 degrees Celsius initial column temperature is cooled by natural convection of external air as a primary heat transfer mechanism. The modeling results for the 28-in column equipped with water jacket systems on the external wall surface of the column and water coolant pipe at the center of the CST column demonstrate that the column loaded with 300 Ci/liter heat source can be maintained non-boiling indefinitely. Sensitivity calculations for several alternate column sizes, heat loads of the packed column, engineered cooling systems, and various ambient conditions at the exterior wall of the column have been performed under the reference conditions of the CST-salt solution to assess the impact of those parameters on the peak temperatures of the packed column for a given transient time. The results indicate that a water-coolant pipe at the center of the CST column filled with salt solution is the most effective one among the potential design parameters related to the thermal energy dissipation of decay heat load. It is noted that the cooling mechanism at the wall boundary of the column has significant impact on maximum and wall temperatures of the column. In addition, the results computed by the present model were verified by the theoretical results. The analysis results will provide quantitative information associated with the process heat control and management of the CST base design. For example, transient responses of the CST system under a loss-of-flow accident condition will provide safety design information for an emergency cooling system of the column.

Lee, S.Y.

2004-02-19

269

Column Liquid Chromatography.  

ERIC Educational Resources Information Center

Reviews literature covering developments of column liquid chromatography during 1982-83. Areas considered include: books and reviews; general theory; columns; instrumentation; detectors; automation and data handling; multidimensional chromatographic and column switching techniques; liquid-solid chromatography; normal bonded-phase, reversed-phase,…

Majors, Ronald E.; And Others

1984-01-01

270

3D printed metal columns for capillary liquid chromatography.  

PubMed

Coiled planar capillary chromatography columns (0.9 mm I.D. × 60 cm L) were 3D printed in stainless steel (316L), and titanium (Ti-6Al-4V) alloys (external dimensions of ~5 × 30 × 58 mm), and either slurry packed with various sized reversed-phase octadecylsilica particles, or filled with an in situ prepared methacrylate based monolith. Coiled printed columns were coupled directly with 30 × 30 mm Peltier thermoelectric direct contact heater/cooler modules. Preliminary results show the potential of using such 3D printed columns in future portable chromatographic devices. PMID:25285334

Sandron, S; Heery, B; Gupta, V; Collins, D A; Nesterenko, E P; Nesterenko, P N; Talebi, M; Beirne, S; Thompson, F; Wallace, G G; Brabazon, D; Regan, F; Paull, B

2014-12-21

271

Microchip-based capillary electrochromatography using packed beds.  

PubMed

Integration of a packed column onto a microchip for performance of capillary electrochromatography (CEC) is described. The quartz device incorporated a cross-injector, and a double weir trapping design for formation of 1, 2 and 5 mm long CEC columns. Three fluorescent dyes were baseline-resolved with plate numbers of 330,(330,000 plates/m; height equivalent to a theoretical plate, H = 3.0 microm) for BODIPY 493/503, 360 (360,000 plates/m; H = 2.8 microm) for rhodamine 123 and 244 (244,000 plates/m; H = 4.1 microm) for acridine orange (AO) with 500 V applied on a 1 mm long column. The 2 mm column yielded approximately 1.8 times more theoretical plates than did the 1 mm column, when operated at the same flow rate. Van Deemter plots were obtained for the three column lengths, showing increased plate height for the 5 mm length. A 2 mm column gave peak height and area relative standard deviation (RSD) values of 2.5 and 3.3%, respectively, as averages for the three dyes (n = 15). The RSD for the dye retention times was 1% (n = 6) over one day, and 3% (n = 30) over five days. Indirect fluorescence detection of thiourea and of amino acids was possible using a neutral indicator dye (BODIPY 493/503), with a detection limit of 10 microM for amino acids. PMID:12973805

Jemere, Abebaw B; Oleschuk, Richard D; Harrison, D Jed

2003-09-01

272

DESIGN SCALE-UP SUITABILITY FOR AIR-STRIPPING COLUMNS (JOURNAL VERSION)  

EPA Science Inventory

An investigation was conducted to determine the suitability of a design scale-up from pilot-scale to full-scale air-stripping columns used in the removal of volatile organic compounds from contaminated water supplies. Forty-eight experimental runs were made in packed columns of f...

273

EFFECT OF NITRATE-BASED BIOREMEDIATION ON CONTAMINANT DISTRIBUTION AND SEDIMENT TOXICITY-COLUMN STUDY  

EPA Science Inventory

A laboratory column study was set up to evaluate changes in contaminant distribution and sediment toxicity following nitrate-based bioremediation and to correlate toxicity reduction with loss of fuel components. Glass columns were packed with sediment from an aquifer that had be...

274

Amino acid analysis using core-shell particle column.  

PubMed

In this study, the separation efficiency of a core-shell particle column was compared with particle-packed and monolithic silica columns, which showed that the core-shell particle column had a smaller theoretical plate height and that its separation efficiency was not affected significantly by the increase in flow rate. A fast HPLC method using a core-shell particle column was developed for the determination of amino acids. 4-Fluoro-7-nitro-2,1,3-benzoxadiazole (NBD-F) was used as a fluorescence derivatization reagent for amino acids, followed by separation on a core-shell Kinetex C18 column. The analysis time for 21 NBD-amino acids was within 7min, which was faster than that in our previous studies with conventional particle-packed columns or monolithic silica columns. The linearities of the calibration curves for all the amino acids were found to be good over a range of injection amounts from 40fmol to 40pmol. The accuracies for the amino acid determinations were 90.9-107%. The method was proved to have potential for the fast determination of amino acids in biological samples. PMID:23022276

Song, Yanting; Funatsu, Takashi; Tsunoda, Makoto

2013-05-15

275

Mass transfer kinetics, band broadening and column efficiency.  

PubMed

Important progress was recently made in our understanding of the physico-chemical aspects of mass transfer kinetics in chromatographic columns, in methods used for accurate determination of the different contributions to the height equivalent to a theoretical plate (HETP), and in the application of these advances to the elucidation of mass transfer mechanisms in columns packed with recent chromatographic supports (sub-2 ?m fully porous particles, sub-3 ?m core-shell particles, and monoliths). The independent contributions to the HETP are longitudinal diffusion, eddy dispersion, liquid-solid mass transfer (including trans-particle or trans-skeleton mass transfer and external film mass transfer), and the contributions caused by the thermal heterogeneity of the column. The origin and importance of these contributions are investigated in depth. This work underlines the areas in which improvements are needed, an understanding of the contribution of the external film mass transfer term, a better design of HPLC instruments providing a decrease of the extra-column band broadening contributions to the apparent HETP, the development of better packing procedures giving more radially homogeneous column beds, and new packing materials having a higher thermal conductivity to eliminate the nefarious impact of heat effects in very high pressure liquid chromatography (vHPLC) and supercritical fluid chromatography (SFC). PMID:21664619

Gritti, Fabrice; Guiochon, Georges

2012-01-20

276

Packing-Limited Growth  

E-print Network

We consider growing spheres seeded by random injection in time and space. Growth stops when two spheres meet leading eventually to a jammed state. We study the statistics of growth limited by packing theoretically in d dimensions and via simulation in d=2, 3, and 4. We show how a broad class of such models exhibit distributions of sphere radii with a universal exponent. We construct a scaling theory that relates the fractal structure of these models to the decay of their pore space, a theory that we confirm via numerical simulations. The scaling theory also predicts an upper bound for the universal exponent and is in exact agreement with numerical results for d=4.

Peter Sheridan Dodds; Joshua S. Weitz

2002-03-12

277

Packing Products: Polystyrene vs. Cornstarch  

ERIC Educational Resources Information Center

Packing materials such as polystyrene take thousands of years to decompose, whereas packing peanuts made from cornstarch, which some companies are now using, can serve the same purpose, but dissolve in water. The author illustrates this point to her class one rainy day using the sculptures students made from polystyrene and with the cornstarch…

Starr, Suzanne

2009-01-01

278

The proof of the packing  

E-print Network

The proof of the packing Kepler's Conjecture: How Some of the Greatest Minds in History Helped astronomer Johannes Kepler stated that no packing could be denser than that of the face-centred cubic (f space. It took mathematicians some 400 years to prove him right. Kepler's Conjecture gives

Sloane, Neil J. A.

279

Potential bleaching techniques for corn distillers grains  

Technology Transfer Automated Retrieval System (TEKTRAN)

The ethanol industry is booming, and extensive research is now being pursued to develop alternative uses for distillers dried grains (DDG) and distillers dried grains with solubles (DDGS), coproducts of the ethanol production process. Currently, DDG and DDGS are used exclusively as livestock feed. P...

280

Distillation of Bell states in open systems  

SciTech Connect

In this work we show that the distillation protocol proposed by P. Chen et al. [Phys. Rev. A 54, 3824 (1996)] allows one to distill Bell states at any time for a system evolving in vacuum and prepared in an initial singlet. It is also shown that the same protocol, applied in nonzero temperature thermal baths, yields a considerable recovering of entanglement.

Isasi, E.; Mundarain, D. [Departamento de Fisica, Seccion de Fenomenos Opticos, Universidad Simon Bolivar, Apartado Postal 89000, Caracas 1080A (Venezuela, Bolivarian Republic of)

2010-04-15

281

Recycling of Waste Acetone by Fractional Distillation  

ERIC Educational Resources Information Center

Distillation is a ubiquitous technique in the undergraduate organic chemistry curriculum; the technique dates back to ca. 3500 B.C.E. With the emergence of green chemistry in the 1990s, the importance of emphasizing responsible waste management practices for future scientists is paramount. Combining the practice of distillation with the message…

Weires, Nicholas A.; Johnston, Aubrey; Warner, Don L.; McCormick, Michael M.; Hammond, Karen; McDougal, Owen M.

2011-01-01

282

Comparison of advanced distillation control methods. Second annual report  

SciTech Connect

Detailed dynamic simulations of three industrial distillation columns (a propylene/propane splitter, a xylene/toluene column, and a depropanizer) have been used to study the issue of configuration selection for diagonal PI dual composition controls. ATV identification with on-line detuning was used for tuning the diagonal PI composition controllers. Each configuration was evaluated with respect to steady-state RGA values, sensitivity to feed composition changes, and open loop dynamic performance. Each configuration was tuned using setpoint changes over a wider range of operation for robustness and tested for feed composition upsets. Overall, configuration selection was shown to have a dominant effect upon control performance. Configuration analysis tools (e.g., RGA, condition number, disturbance sensitivity), were found to reject configuration choices that are obviously poor choices, but were unable to critically differentiate between the remaining viable choices. Configuration selection guidelines are given although it is demonstrated that the most reliable configuration selection approach is based upon testing the viable configurations using dynamic column simulators.

NONE

1996-11-01

283

Comparison of advanced distillation control methods. Second annual report  

SciTech Connect

Detailed dynamic simulations of two industrial distillation columns (a propylene/propane splitter and a xylene/toluene column) have been used to study the issue of configuration selection for diagonal PI dual composition controls. Auto Tune Variation (ATV) identification with on-line detuning was used for tuning the diagonal proportional integral (PI) composition controls. Each configuration was evaluated with respect to steady-state relative gain array (RGA) values, sensitivity to feed composition changes, and open loop dynamic performance. Each configuration was tuned using setpoint changes over a wider range of operation for robustness and tested for feed composition upsets. Overall, configuration selection was shown to have a dominant effect upon control performance. Configuration analysis tools (e.g., RGA, condition number, disturbance sensitivity) were found to reject configuration choices that are obviously poor choices, but were unable to critically differentiate between the remaining viable choices. Configuration selection guidelines are given although it is demonstrated that the most reliable configuration selection approach is based upon testing the viable configurations using dynamic column simulators.

Riggs, J.B.

1996-11-01

284

27 CFR 19.65 - Experimental distilled spirits plants.  

Code of Federal Regulations, 2010 CFR

...false Experimental distilled spirits plants. 19.65 Section 19.65 Alcohol...TREASURY LIQUORS DISTILLED SPIRITS PLANTS Administrative and Miscellaneous Provisions...65 Experimental distilled spirits plants. The appropriate TTB officer may...

2010-04-01

285

27 CFR 19.32 - Experimental distilled spirits plants.  

Code of Federal Regulations, 2011 CFR

...false Experimental distilled spirits plants. 19.32 Section 19.32 Alcohol...TREASURY LIQUORS DISTILLED SPIRITS PLANTS Administrative and Miscellaneous Provisions...32 Experimental distilled spirits plants. (a) General. The...

2011-04-01

286

40 CFR 721.9635 - Terpene residue distillates.  

Code of Federal Regulations, 2010 CFR

...2010-07-01 2010-07-01 false Terpene residue distillates. 721.9635 Section...Specific Chemical Substances § 721.9635 Terpene residue distillates. (a) Chemical...chemical substance identified generically as terpene residue distillates (PMN...

2010-07-01

287

7 CFR 160.8 - Steam distilled wood turpentine.  

Code of Federal Regulations, 2010 CFR

... 2010-01-01 false Steam distilled wood turpentine. 160.8 Section 160.8 ...STORES General § 160.8 Steam distilled wood turpentine. The designation “steam distilled wood turpentine” shall refer to the kind...

2010-01-01

288

7 CFR 160.9 - Destructively distilled wood turpentine.  

Code of Federal Regulations, 2010 CFR

...2010-01-01 false Destructively distilled wood turpentine. 160.9 Section 160.9...General § 160.9 Destructively distilled wood turpentine. The designation “destructively distilled wood turpentine” shall refer to the kind...

2010-01-01

289

7 CFR 160.9 - Destructively distilled wood turpentine.  

Code of Federal Regulations, 2013 CFR

...2013-01-01 false Destructively distilled wood turpentine. 160.9 Section 160.9...General § 160.9 Destructively distilled wood turpentine. The designation “destructively distilled wood turpentine” shall refer to the kind...

2013-01-01

290

7 CFR 160.8 - Steam distilled wood turpentine.  

Code of Federal Regulations, 2013 CFR

... 2013-01-01 false Steam distilled wood turpentine. 160.8 Section 160.8 ...STORES General § 160.8 Steam distilled wood turpentine. The designation “steam distilled wood turpentine” shall refer to the kind...

2013-01-01

291

7 CFR 160.9 - Destructively distilled wood turpentine.  

Code of Federal Regulations, 2014 CFR

...2014-01-01 false Destructively distilled wood turpentine. 160.9 Section 160.9...General § 160.9 Destructively distilled wood turpentine. The designation “destructively distilled wood turpentine” shall refer to the kind...

2014-01-01

292

7 CFR 160.9 - Destructively distilled wood turpentine.  

Code of Federal Regulations, 2011 CFR

...2011-01-01 false Destructively distilled wood turpentine. 160.9 Section 160.9...General § 160.9 Destructively distilled wood turpentine. The designation “destructively distilled wood turpentine” shall refer to the kind...

2011-01-01

293

7 CFR 160.8 - Steam distilled wood turpentine.  

Code of Federal Regulations, 2012 CFR

... 2012-01-01 false Steam distilled wood turpentine. 160.8 Section 160.8 ...STORES General § 160.8 Steam distilled wood turpentine. The designation “steam distilled wood turpentine” shall refer to the kind...

2012-01-01

294

7 CFR 160.8 - Steam distilled wood turpentine.  

Code of Federal Regulations, 2014 CFR

... 2014-01-01 false Steam distilled wood turpentine. 160.8 Section 160.8 ...STORES General § 160.8 Steam distilled wood turpentine. The designation “steam distilled wood turpentine” shall refer to the kind...

2014-01-01

295

7 CFR 160.9 - Destructively distilled wood turpentine.  

Code of Federal Regulations, 2012 CFR

...2012-01-01 false Destructively distilled wood turpentine. 160.9 Section 160.9...General § 160.9 Destructively distilled wood turpentine. The designation “destructively distilled wood turpentine” shall refer to the kind...

2012-01-01

296

7 CFR 160.8 - Steam distilled wood turpentine.  

Code of Federal Regulations, 2011 CFR

... 2011-01-01 false Steam distilled wood turpentine. 160.8 Section 160.8 ...STORES General § 160.8 Steam distilled wood turpentine. The designation “steam distilled wood turpentine” shall refer to the kind...

2011-01-01

297

27 CFR 19.32 - Experimental distilled spirits plants.  

Code of Federal Regulations, 2014 CFR

...false Experimental distilled spirits plants. 19.32 Section 19.32 Alcohol...TREASURY ALCOHOL DISTILLED SPIRITS PLANTS Administrative and Miscellaneous Provisions...32 Experimental distilled spirits plants. (a) General. The...

2014-04-01

298

Recycling of acetone by distillation  

SciTech Connect

The Resource Conservation Recovery Act (RCRA) identifies spent acetone solvent as a listed hazardous waste. At Fernald, acetone has been spent that has been contaminated with radionuclides and therefore is identified as a mixed hazardous waste. At the time of this publication there is no available approved method of recycling or disposal of radioactively contaminated spent acetone solvent. The Consent Decree with the Ohio EPA and the Consent Agreement with the United States EPA was agreed upon for the long-term compliant storage of hazardous waste materials. The purpose of this project was to demonstrate the feasibility for safely decontaminating spent acetone to background levels of radioactivity for reuse. It was postulated that through heat distillation, radionuclides could be isolated from the spent acetone.

Brennan, D.L.; Campbell, B.A.; Phelan, J.E.; Harper, M.

1992-09-01

299

Shell middle distillate hydrogenation process  

SciTech Connect

The strive towards cleaner environment has lead to low sulfur specifications for middle distillate fuels. In addition compositional specifications are presently debated. Thus, to meet future emissions standards regarding, specifically, particulates emissions, the motor industry calls for improved automotive gasoil quality. Although automotive gasoil quality affects emissions from diesel engines it is considered less influential than engine design and maintenance. Sulfur, density and cetane number are the fuel properties having the greatest influence on diesel engine emissions although also aromatics and endpoint specifications have been defined in environmentally adopted government initiatives. This paper reviews the options which are available to tackle these new requirements. The high severity single stage concept (using conventional mixed sulfides catalysts) will be discussed in its potential to meet more severe product requirements as well as in terms of its limitations, especially at the point of aromatics saturation and cetaine upgrading. Furthermore, it is shown that the option of severe hydrotreating followed by hydrogenation with conventional noble metal catalysts is preferred if deep aromatics saturation is aimed at. However, this conventional two stage concept has limitations with respect to heaviness and sulfur and nitrogen content of feedstocks. The new Shell Middle Distillate Hydrogenation (SMDH) technology, applying a (semi) two stage approach based on the Shell developed hydrogenation catalyst is presented. The SMDH process will be discussed in its potential to break the limitations of the conventional options. The new catalyst is crucial in this process and allows a highly integrated mode of operation. A number of applications of this novel process will be discussed.

Lucien, J.P. [Companie Rhenane de Raffinage Reichstett, Reichstett Vendenheim (France); Berg, J.P. van den; Hooijdonk, H.M.J.H. van; Thielemans, G.L.B. [Shell Internationale Petroleum Mij., The Hague (Netherlands); Germaine, G. [Shell Recherche SA, Grand-Couronne (France); Gjers, M. [Shell Raffinaderi AB, Gothenburg (Sweden)

1994-12-31

300

7 CFR 51.1270 - Packing.  

Code of Federal Regulations, 2010 CFR

...FRUITS, VEGETABLES AND OTHER PRODUCTS 1,2 (INSPECTION, CERTIFICATION, AND STANDARDS) United States Standards for Summer and Fall Pears 1 Standard Pack § 51.1270 Packing. (a) Each package shall be packed so that the pears in the shown...

2010-01-01

301

7 CFR 51.1270 - Packing.  

Code of Federal Regulations, 2011 CFR

...FRUITS, VEGETABLES AND OTHER PRODUCTS 1,2 (INSPECTION, CERTIFICATION, AND STANDARDS) United States Standards for Summer and Fall Pears 1 Standard Pack § 51.1270 Packing. (a) Each package shall be packed so that the pears in the shown...

2011-01-01

302

PARTICLE PACKING PROBLEMS IN LOW SPACE DIMENSIONS  

E-print Network

vectors). · Periodic packing Packing obtained by placing a fixed arrangement of n ( 1) convex particles dependent. · Terms "random" and "close packed" are at odds with one another. · There has never been

Torquato, Salvatore

303

Inelastic column behavior  

NASA Technical Reports Server (NTRS)

The significant findings of a theoretical study of column behavior in the plastic stress range are presented. When the behavior of a straight column is regarded as the limiting behavior of an imperfect column as the initial imperfection (lack of straightness) approaches zero, the departure from the straight configuration occurs at the tangent-modulus load. Without such a concept of the behavior of a straight column, one is led to the unrealistic conclusion that lateral deflection of the column can begin at any load between the tangent-modulus value and the Euler load, based on the original elastic modulus. A family of curves showing load against lateral deflection is presented for idealized h-section columns of various lengths and of various materials that have a systematic variation of their stress-strain curves.

Duberg, John E; Wilder, Thomas W , III

1952-01-01

304

Separation characteristics of multistage water/hydrogen exchange column for water detritiation in fusion reactors  

SciTech Connect

A simulation code of multistage chemical exchange columns has been developed. The sieve trays for liquid-vapor scrubbing and the catalyst beds for vapor-hydrogen exchange reactions are alternately piled within the column. The code deals with all the twelve molecular species of hydrogen gas and water; and is based on the Newton-Raphson method. The characteristics of the column were discussed from the calculated results by this code such as effects of temperature and pressure. Similar to the distillation columns, the phase flow rates within the column (hydrogen gas and water vapor) and product flow rates have large effects on the separation performance of the column. A control method of the column was also proposed from these calculated results. 9 refs., 5 figs., 4 tabs.

Yamanishi, T.; Okuno, K. [Japan Atomic Energy Research Lab., Ibaraki (Japan)

1995-10-01

305

Nasal septal packing: which one?  

PubMed

The aim of this study was to investigate the effects of four different types of nasal packs on pain, nasal fullness and postoperative bleeding following septoplasty. Prospective randomised double blind study was conducted. The study group included 119 patients who underwent endonasal septoplasty under general anaesthesia. Four types of nasal packing materials were utilized: (1) Merocel standard 8-cm nasal dressing without airway, (2) Doyle Combo splint (DCS), (3) Merocel in a glove finger and (4) Vaseline gauze. All packs were removed at the 48th hour (±3 h) after the surgery. Three different variables were investigated following the surgical procedure: (1) pain, (2) nasal fullness and (3) bleeding after removal of the nasal packing material. DCS produced the greatest pain at the first and sixth postoperative hours. At the first postoperative day, the greatest pain score was reported for Merocel in the glove finger and the least for Merocel. The pain scores during the removal of the nasal packings were highest for Merocel and lowest for Merocel in the glove finger. DCS had the lowest nasal fullness score. Bleeding ratio was highest for Merocel, followed by Vaseline gauze, DCS and Merocel in the glove finger. Many different commercially available packing materials are presently used, each with inherent advantages and disadvantages. We evaluated the pain, nasal fullness and bleeding potential of four nasal packing materials and determined that Merocel had the highest pain potential during removal and the highest rate of bleeding following removal. PMID:22160143

Ac?o?lu, Engin; Edizer, Deniz Tuna; Yi?it, Özgür; Onur, F?rat; Alkan, Zeynep

2012-07-01

306

Valve stem and packing assembly  

DOEpatents

A valve stem and packing assembly is provided in which a rotatable valve stem includes a first tractrix surface for sliding contact with a stem packing and also includes a second tractrix surface for sliding contact with a bonnet. Force is applied by means of a spring, gland flange, and gland on the stem packing so the stem packing seals to the valve stem and bonnet. This configuration serves to create and maintain a reliable seal between the stem packing and the valve stem. The bonnet includes a second complementary tractrix surface for contacting the second sliding tractrix surface, the combination serving as a journal bearing for the entire valve stem and packing assembly. The journal bearing so configured is known as a Schiele's pivot. The Schiele's pivot also serves to maintain proper alignment of the valve stem with respect to the bonnet. Vertical wear between the surfaces of the Schiele's pivot is uniform at all points of contact between the second sliding tractrix surface and the second complementary tractrix surface of a bonnet. The valve stem is connected to a valve plug by means of a slip joint. The valve is opened and closed by rotating the valve stem. The slip joint compensates for wear on the Schiele's pivot and on the valve plug. A ledge is provided on the valve bonnet for the retaining nut to bear against. The ledge prevents over tightening of the retaining nut and the resulting excessive friction between stem and stem packing. 2 figures.

Wordin, J.J.

1991-09-03

307

Valve stem and packing assembly  

DOEpatents

A valve stem and packing assembly is provided in which a rotatable valve stem includes a first tractrix surface for sliding contact with a stem packing and also includes a second tractrix surface for sliding contact with a bonnet. Force is applied by means of a spring, gland flange, and gland on the stem packing so the stem packing seals to the valve stem and bonnet. This configuration serves to create and maintain a reliable seal between the stem packing and the valve stem. The bonnet includes a second complementary tractrix surface for contacting the second sliding tractrix surface, the combination serving as a journal bearing for the entire valve stem and packing assembly. The journal bearing so configured is known as a Schiele's pivot. The Schiele's pivot also serves to maintain proper alignment of the valve stem with respect to the bonnet. Vertical wear between the surfaces of the Schiele's pivot is uniform at all points of contact between the second sliding tractrix surface and the second complementary tractrix surface of a bonnet. The valve stem is connected to a valve plug by means of a slip joint. The valve is opened and closed by rotating the valve stem. The slip joint compensates for wear on the Schiele's pivot and on the valve plug. A ledge is provided on the valve bonnet for the retaining nut to bear against. The ledge prevents overtightening of the retaining nut and the resulting excessive friction between stem and stem packing.

Wordin, John J. (Bingham County, ID)

1991-01-01

308

Dense periodic packings of tori.  

PubMed

Dense packings of nonoverlapping bodies in three-dimensional Euclidean space R(3) are useful models of the structure of a variety of many-particle systems that arise in the physical and biological sciences. Here we investigate the packing behavior of congruent ring tori in R(3), which are multiply connected nonconvex bodies of genus 1, as well as horn and spindle tori. Specifically, we analytically construct a family of dense periodic packings of unlinked tori guided by the organizing principles originally devised for simply connected solid bodies [Torquato and Jiao, Phys. Rev. E 86, 011102 (2012)]. We find that the horn tori as well as certain spindle and ring tori can achieve a packing density not only higher than that of spheres (i.e., ?/sqrt[18] = 0.7404...) but also higher than the densest known ellipsoid packings (i.e., 0.7707...). In addition, we study dense packings of clusters of pair-linked ring tori (i.e., Hopf links), which can possess much higher densities than corresponding packings consisting of unlinked tori. PMID:25353448

Gabbrielli, Ruggero; Jiao, Yang; Torquato, Salvatore

2014-02-01

309

Dense periodic packings of tori  

NASA Astrophysics Data System (ADS)

Dense packings of nonoverlapping bodies in three-dimensional Euclidean space R3 are useful models of the structure of a variety of many-particle systems that arise in the physical and biological sciences. Here we investigate the packing behavior of congruent ring tori in R3, which are multiply connected nonconvex bodies of genus 1, as well as horn and spindle tori. Specifically, we analytically construct a family of dense periodic packings of unlinked tori guided by the organizing principles originally devised for simply connected solid bodies [22 Torquato and Jiao, Phys. Rev. E 86, 011102 (2012), 10.1103/PhysRevE.86.011102]. We find that the horn tori as well as certain spindle and ring tori can achieve a packing density not only higher than that of spheres (i.e., ? /?18 =0.7404...) but also higher than the densest known ellipsoid packings (i.e., 0.7707...). In addition, we study dense packings of clusters of pair-linked ring tori (i.e., Hopf links), which can possess much higher densities than corresponding packings consisting of unlinked tori.

Gabbrielli, Ruggero; Jiao, Yang; Torquato, Salvatore

2014-02-01

310

Toward rapid preparation of capillary columns for electrochromatography use.  

PubMed

CEC is a high performance electrodriving liquid phase separation technique. It does not need complex and sophisticated high pressure instrumentation for nanoflow driving. This is attractive for parallel multicolumn analysis. To this end, high throughput methods for column preparation are needed to support the use of multiple columns. In this study, we directly used CEC mobile phase solution as the packing solvent, and realized rapid preparation of capillary columns based on a single particle fritting technology. The method presented high preparation throughput compared with other reported methods based on various fritting technologies. The single particle fritting approach promoted column preparation throughput to 1 column/h, including all the fritting, packing and conditioning steps. The rapidly prepared columns showed consistently high efficiency of up to 150?000 plates per meter, and usefulness in reversed phase CEC of neutral, charged and biomolecules. With standard peptides as the sample, excellent long term reproducibility (better than 0.8%RSD, ten days, for retention times) was observed. PMID:24301798

Liu, Qing; Wang, Lin; Zhou, Zhuoheng; Wang, Qiuquan; Yan, Lijuan; Zhang, Bo

2014-03-01

311

High efficiency, high temperature separations on silica based monolithic columns.  

PubMed

The effect of temperature on separation using reversed-phase monolithic columns has been investigated using a nano-LC pumping system for gradient separation of tryptic peptides with MS detection. A goal of this study was to find optimal conditions for high-speed separations. The chromatographic performance of the columns was evaluated by peak capacity and peak capacity per time unit. Column lengths ranging from 20 to 100 cm and intermediate gradient times from 10 to 30 min were investigated to assess the potential of these columns in a final step separation, e.g. after fractionation or specific sample preparation. Flow rates from 250 to 2000 nL/min and temperatures from 20 to 120°C were investigated. Temperature had a significant effect on fast separations, and a flow rate of 2000 nL/min and a temperature of 80°C gave the highest peak capacity per time unit. These settings produced 70% more protein identifications in a biological sample compared to a conventional packed column. Alternatively, an equal amount of protein identifications was obtained with a 40% reduction in run time compared to the conventional packed column. PMID:21899856

Rogeberg, Magnus; Wilson, Steven Ray; Malerod, Helle; Lundanes, Elsa; Tanaka, Nobuo; Greibrokk, Tyge

2011-10-14

312

Monolithic silica rod columns for high-efficiency reversed-phase liquid chromatography.  

PubMed

Chromatographic properties of a new type of monolithic silica rod columns were examined. Silica rod columns employed for the study were prepared from tetramethoxysilane, modified with octadecylsilyl moieties, and encased in a stainless-steel protective column with two polymer layers between the silica and the stainless-steel tubing. A 25 cm column provided up to 45,000 theoretical plates for aromatic hydrocarbons, or a minimum plate height of about 5.5 ?m, at optimum linear velocity of ca. 2.3 mm/s and back pressure of 7.5 MPa in an acetonitrile-water (80/20, v/v) mobile phase at 40°C. The permeability of the column was similar to that of a column packed with 5 ?m particles, with K(F) about 2.4×10(-14) m(2) (based on the superficial linear velocity of the mobile phase), while the plate height value equivalent to that of a column packed with 2.5 ?m particles. Generation of 80,000-120,000 theoretical plates was feasible with back pressure below 30 MPa by employing two or three 25 cm columns connected in series. The use of the long columns enabled facile generation of large numbers of theoretical plates in comparison with conventional monolithic silica columns or particulate columns. Kinetic plot analysis indicates that the monolithic columns operated at 30 MPa can provide faster separations than a column packed with totally porous 3-?m particles operated at 40 MPa in a range where the number of theoretical plates (N) is greater than 50,000. PMID:21176839

Miyazaki, Shota; Takahashi, Masakazu; Ohira, Masayoshi; Terashima, Hiroyuki; Morisato, Kei; Nakanishi, Kazuki; Ikegami, Tohru; Miyabe, Kanji; Tanaka, Nobuo

2011-04-15

313

An improved model for multiple effect distillation  

E-print Network

Increasing global demand for fresh water is driving research and development of advanced desalination technologies. As a result, a detailed model of multiple effect distillation (MED) is developed that is flexible, simple ...

Mistry, Karan H.

314

Minimizing corrosion in coal liquid distillation  

DOEpatents

In an atmospheric distillation tower of a coal liquefaction process, tower materials corrosion is reduced or eliminated by introduction of boiling point differentiated streams to boiling point differentiated tower regions.

Baumert, Kenneth L. (Emmaus, PA); Sagues, Alberto A. (Lexington, KY); Davis, Burtron H. (Georgetown, KY)

1985-01-01

315

Development of energy efficient membrane distillation systems  

E-print Network

Membrane distillation (MD) has shown potential as a means of desalination and water purification. As a thermally driven membrane technology which runs at relatively low pressure, which can withstand high salinity feed ...

Summers, Edward K

2013-01-01

316

Identification of the more complex triacylglycerols in bovine milk fat by gas chromatography-mass spectrometry using polar capillary columns.  

PubMed

The fourth most volatile 2.5% molecular distillate of butteroil obtained by redistillation of the most volatile 10% cut was examined by gas chromatography on a polar capillary column (RSL-300) with electron impact and chemical ionization mass spectrometry. For this purpose the distillate was first freed from the acetyldiacylglycerols by thin-layer chromatography on plain silica gel and the remainder resolved into long and short chain length saturates, cis- and trans-monoenes, dienes and trienes by thin-layer chromatography on silver nitrate-silica gel. The order of gas chromatographic elution was established for more than 100 major and minor species making up the bulk of the molecular distillate. The results were used to derive the quantitative composition of the triacylglycerol species making up the various peaks obtained by polar capillary column gas chromatography of the total molecular distillate, which closely resembles the lower half of the molecular mass distribution of whole bovine milk fat. PMID:3243860

Myher, J J; Kuksis, A; Marai, L; Sandra, P

1988-10-28

317

Reducing Energy Usage in Extractive Distillation  

E-print Network

, .. ~ REDUCING ENERGY USAGE IN,EXTRACTIVE DISTILLATION A. C. Saxena V. A. Bhandari Polysar Limited Sarnia, Ontario, Canada Abstract Butadiene 1:3 is separated from other C. hydrocarbons by extractive distillation in a sieve plate tower... not affect tower stability and the operators h~,e adapted well to the new control strategy. INTRODUCTION For its rubber manufacturing operations at Sarnia, Ontario, Canada, Polysar Limited extracts butadiene 1:3 from a mixed C. hydrocarbon feed...

Saxena, A. C.; Bhandari, V. A.

318

Multipartite secret key distillation and bound entanglement  

SciTech Connect

Recently it has been shown that quantum cryptography beyond pure entanglement distillation is possible and a paradigm for the associated protocols has been established. Here we systematically generalize the whole paradigm to the multipartite scenario. We provide constructions of new classes of multipartite bound entangled states, i.e., those with underlying twisted Greenberger-Horne-Zeilinger (GHZ) structure and nonzero distillable cryptographic key. We quantitatively estimate the key from below with the help of the privacy squeezing technique.

Augusiak, Remigiusz; Horodecki, Pawel [Faculty of Applied Physics and Mathematics, Gdansk University of Technology, Narutowicza 11/12, 80-952 Gdansk (Poland) and ICFO-Institute Ciencies Fotoniques, Mediterranean Technology Park, 08860 Castelldefels (Barcelona) (Spain); Faculty of Applied Physics and Mathematics, Gdansk University of Technology, Narutowicza 11/12, 80-952 Gdansk (Poland)

2009-10-15

319

27 CFR 17.162 - Receipt of distilled spirits.  

Code of Federal Regulations, 2010 CFR

...2010-04-01 false Receipt of distilled spirits. 17.162 Section 17.162 Alcohol...LIQUORS DRAWBACK ON TAXPAID DISTILLED SPIRITS USED IN MANUFACTURING NONBEVERAGE PRODUCTS...Records § 17.162 Receipt of distilled spirits. (a) Distilled spirits...

2010-04-01

320

27 CFR 1.90 - Distilled spirits in bulk.  

Code of Federal Regulations, 2010 CFR

...2010-04-01 2010-04-01 false Distilled spirits in bulk. 1.90 Section 1.90 Alcohol...ADMINISTRATION ACT, NONINDUSTRIAL USE OF DISTILLED SPIRITS AND WINE, BULK SALES AND BOTTLING OF DISTILLED SPIRITS Bulk Sales and Bottling of Distilled...

2010-04-01

321

CHEM333: Lab Experiment 3: Distillation and Gas Chromatography  

E-print Network

CHEM­333: Lab Experiment 3: Distillation and Gas Chromatography: Prelab-Assignment: read Chapters 5 and evaluate the efficiency of the fractional distillation versus simple distillation by gas chromatography discussion of gas chromatography. For your distillations (remember to add boiling stones) you will use 30 m

Taber, Douglass

322

Quantum Nonlocal Boxes Exhibit Stronger Distillability  

NASA Astrophysics Data System (ADS)

The hypothetical nonlocal box (NLB) proposed by Popescu and Rohrlich allows two spatially separated parties, Alice and Bob, to exhibit stronger than quantum correlations. If the generated correlations are weak, they can sometimes be distilled into a stronger correlation by repeated applications of the NLB. Motivated by the limited distillability of NLBs, we initiate here a study of the distillation of correlations for nonlocal boxes that output quantum states rather than classical bits (qNLBs). We propose a new protocol for distillation and show that it asymptotically distills a class of correlated quantum nonlocal boxes to the value (1)/(2)(3? {3}+1) ? 3.098076, whereas in contrast, the optimal non-adaptive parity protocol for classical nonlocal boxes asymptotically distills only to the value 3.0. We show that our protocol is an optimal non-adaptive protocol for 1, 2 and 3 qNLB copies by constructing a matching dual solution for the associated primal semidefinite program (SDP). We conclude that qNLBs are a stronger resource for nonlocality than NLBs. The main premise that develops from this conclusion is that the NLB model is not the strongest resource to investigate the fundamental principles that limit quantum nonlocality. As such, our work provides strong motivation to reconsider the status quo of the principles that are known to limit nonlocal correlations under the framework of qNLBs rather than NLBs.

Høyer, Peter; Rashid, Jibran

2013-06-01

323

7 CFR 51.1311 - Packing.  

Code of Federal Regulations, 2011 CFR

... United States Standards for Winter Pears 1 Standard Pack § 51.1311 Packing...Each package shall be packed so that the pears in the shown face shall be reasonably...of the contents of the package. (b) Pears packed in any container shall be...

2011-01-01

324

7 CFR 51.1311 - Packing.  

Code of Federal Regulations, 2013 CFR

... United States Standards for Winter Pears 1 Standard Pack § 51.1311 Packing...Each package shall be packed so that the pears in the shown face shall be reasonably...of the contents of the package. (b) Pears packed in any container shall be...

2013-01-01

325

7 CFR 51.1270 - Packing.  

Code of Federal Regulations, 2012 CFR

...United States Standards for Summer and Fall Pears 1 Standard Pack § 51.1270 Packing...Each package shall be packed so that the pears in the shown face shall be reasonably...of the contents of the package. (b) Pears packed in any container shall be...

2012-01-01

326

7 CFR 51.1270 - Packing.  

Code of Federal Regulations, 2014 CFR

...United States Standards for Summer and Fall Pears 1 Standard Pack § 51.1270 Packing...Each package shall be packed so that the pears in the shown face shall be reasonably...of the contents of the package. (b) Pears packed in any container shall be...

2014-01-01

327

7 CFR 51.1311 - Packing.  

Code of Federal Regulations, 2010 CFR

... United States Standards for Winter Pears 1 Standard Pack § 51.1311 Packing...Each package shall be packed so that the pears in the shown face shall be reasonably...of the contents of the package. (b) Pears packed in any container shall be...

2010-01-01

328

7 CFR 51.1311 - Packing.  

Code of Federal Regulations, 2014 CFR

... United States Standards for Winter Pears 1 Standard Pack § 51.1311 Packing...Each package shall be packed so that the pears in the shown face shall be reasonably...of the contents of the package. (b) Pears packed in any container shall be...

2014-01-01

329

7 CFR 51.1311 - Packing.  

Code of Federal Regulations, 2012 CFR

... United States Standards for Winter Pears 1 Standard Pack § 51.1311 Packing...Each package shall be packed so that the pears in the shown face shall be reasonably...of the contents of the package. (b) Pears packed in any container shall be...

2012-01-01

330

7 CFR 51.1270 - Packing.  

Code of Federal Regulations, 2013 CFR

...United States Standards for Summer and Fall Pears 1 Standard Pack § 51.1270 Packing...Each package shall be packed so that the pears in the shown face shall be reasonably...of the contents of the package. (b) Pears packed in any container shall be...

2013-01-01

331

Nuclear reactor control column  

DOEpatents

The nuclear reactor control column comprises a column disposed within the nuclear reactor core having a variable cross-section hollow channel and containing balls whose vertical location is determined by the flow of the reactor coolant through the column. The control column is divided into three basic sections wherein each of the sections has a different cross-sectional area. The uppermost section of the control column has the greatest cross-sectional area, the intermediate section of the control column has the smallest cross-sectional area, and the lowermost section of the control column has the intermediate cross-sectional area. In this manner, the area of the uppermost section can be established such that when the reactor coolant is flowing under normal conditions therethrough, the absorber balls will be lifted and suspended in a fluidized bed manner in the upper section. However, when the reactor coolant flow falls below a predetermined value, the absorber balls will fall through the intermediate section and into the lowermost section, thereby reducing the reactivity of the reactor core and shutting down the reactor.

Bachovchin, Dennis M. (Plum Borough, PA)

1982-01-01

332

Molecular packing and packing defects in helical membrane proteins.  

PubMed

The packing of helices spanning lipid bilayers is crucial for the stability and function of alpha-helical membrane proteins. Using a modified Voronoi procedure, we calculated packing densities for helix-helix contacts in membrane spanning domains. Our results show that the transmembrane helices of protein channels and transporters are significantly more loosely packed compared with helices in globular proteins. The observed packing deficiencies of these membrane proteins are also reflected by a higher amount of cavities at functionally important sites. The cavities positioned along the gated pores of membrane channels and transporters are noticeably lined by polar amino acids that should be exposed to the aqueous medium when the protein is in the open state. In contrast, nonpolar amino acids surround the cavities in those protein regions where large rearrangements are supposed to take place, as near the hinge regions of transporters or at restriction sites of protein channels. We presume that the observed deficiencies of helix-helix packing are essential for the helical mobility that sustains the function of many membrane protein channels and transporters. PMID:15556989

Hildebrand, Peter Werner; Rother, Kristian; Goede, Andrean; Preissner, Robert; Frömmel, Cornelius

2005-03-01

333

The current revolution in column technology: how it began, where is it going?  

PubMed

This work revisits the exceptionally rapid evolution of the technology of chromatographic columns and the important progress in speed of analysis and resolution power that was achieved over the last ten years. Whereas columns packed with 10 and 5 ?m fully porous particles dominated the field for nearly thirty years (1975-2000), it took barely six years to see the commercialization of monolithic silica rods (2000), their raise to fame and decay to oblivion, the development of finer fully porous particles with size down to 1.7 ?m (2006), and of sub-3 ?m superficially porous particles (2006). Analysis times and plate heights delivered by columns packed with these recent packing materials have then been improved by more than one order of magnitude in this short period of time. This progress has rendered practically obsolete the age-old design of LC instruments. For low molecular weight compounds, analysts can now achieve peak capacities of 40 peaks in about 15s with a hold-up time of the order of 1.5s , in gradient elution, by operating columns packed with sub-3 ?m shell particles at elevated temperatures, provided that they use optimized high pressure liquid chromatographs. This is the ultimate limit allowed by modern instruments, which have an extra-column band broadening contribution of 7 ?L² at 4.0 mL/min and data acquisition rate of 160 Hz. The best 2.1 mm × 50 mm narrow-bore columns packed with 1.7 ?m silica core-shell particles provide peaks that have a variance of 2.1 ?L² for k=1. Finally, this work discusses possible ways to accelerate separations and, in the same time perform these separations at the same level of efficiency as they have today. It seems possible to pack columns with smaller particles, probably down to 1 ?m and operate them with current vHPLC equipments for separations of biochemicals. Analyses of low molecular weight compounds will require new micro-HPLC systems able to operate 1mm I.D. columns at pressures up to 5 kbar, which would eliminate the heat friction problems, and providing extra-column band broadening contributions smaller than 0.1 ?L². Alternatively, a new generation of vHPLC systems with minimal extra-column contributions of less than 0.5 ?L² could run 2.1mm I.D. columns if these latter were to be packed with high heat conductivity materials such as core-shell particles made with an alumina or gold core. PMID:21872874

Gritti, Fabrice; Guiochon, Georges

2012-03-01

334

Electrospun superhydrophobic membranes with unique structures for membrane distillation.  

PubMed

With modest temperature demand, low operating pressure, and high solute rejection, membrane distillation (MD) is an attractive option for desalination, waste treatment, and food and pharmaceutical processing. However, large-scale practical applications of MD are still hindered by the absence of effective membranes with high hydrophobicity, high porosity, and adequate mechanical strength, which are important properties for MD permeation fluxes, stable long-term performance, and effective packing in modules without damage. This study describes novel design strategies for highly robust superhydrophobic dual-layer membranes for MD via electrospinning. One of the newly developed membranes comprises a durable and ultrathin 3-dimensional (3D) superhydrophobic skin and porous nanofibrous support whereas another was fabricated by electrospinning 3D superhydrophobic layers on a nonwoven support. These membranes exhibit superhydrophobicity toward distilled water, salty water, oil-in-water emulsion, and beverages, which enables them to be used not only for desalination but also for other processes. The superhydrophobic dual-layer membrane #3S-N with nanofibrous support has a competitive permeation flux of 24.6 ± 1.2 kg m(-2) h(-1) in MD (feed and permeate temperate were set as 333 and 293 K, respectively) due to the higher porosity of the nanofibrous scaffold. Meanwhile, the membranes with the nonwoven support exhibit greater mechanical strength due to this support combined with better long-term performance because of the thicker 3D superhydrophobic layers. The morphology, pore size, porosity, mechanical properties, and liquid enter pressure of water of these superhydrophobic composite membranes with two different structures are reported and compared with commercial polyvinylidene fluoride membranes. PMID:25147909

Liao, Yuan; Loh, Chun-Heng; Wang, Rong; Fane, Anthony G

2014-09-24

335

Antioxidant Activity of Phytochemicals from Distillers Dried Grain Oil  

Microsoft Academic Search

A distillate was obtained by molecular distillation of oil extracted from distillers dried grains (DDG). The distillers dried\\u000a grain oil distillate (DDGD) contained phytosterols, steryl ferulates, tocopherols, tocotrienols, and carotenoids. DDGD was\\u000a tested for its impact on the oxidative stability index (OSI) at 110 °C of soybean, sunflower, and high-oleic sunflower oils,\\u000a as well as the same oils that were stripped

Jill Kristine Winkler-Moser; Steven Francis Vaughn

2009-01-01

336

Soil column leaching of pesticides.  

PubMed

In this review, I address the practical and theoretical aspects of pesticide soil mobility.I also address the methods used to measure mobility, and the factors that influence it, and I summarize the data that have been published on the column leaching of pesticides.Pesticides that enter the unsaturated soil profile are transported downwards by the water flux, and are adsorbed, desorbed, and/or degraded as they pass through the soil. The rate of passage of a pesticide through the soil depends on the properties of the pesticide, the properties of the soil and the prevailing environmental conditions.Because large amounts of many different pesticides are used around the world, they and their degradates may sometimes contaminate groundwater at unacceptable levels.It is for this reason that assessing the transport behavior and soil mobility of pesticides before they are sold into commerce is important and is one indispensable element that regulators use to assess probable pesticide safety. Both elementary soil column leaching and sophisticated outdoor lysimeter studies are performed to measure the leaching potential for pesticides; the latter approach more reliably reflects probable field behavior, but the former is useful to initially profile a pesticide for soil mobility potential.Soil is physically heterogeneous. The structure of soil varies both vertically and laterally, and this variability affects the complex flow of water through the soil profile, making it difficult to predict with accuracy. In addition, macropores exist in soils and further add to the complexity of how water flow occurs. The degree to which soil is tilled, the density of vegetation on the surface, and the type and amounts of organic soil amendments that are added to soil further affect the movement rate of water through soil, the character of soil adsorption sites and the microbial populations that exist in the soil. Parameters that most influence the rate of pesticide mobility in soil are persistence (DT50) of the pesticide, and its sorption/desorption(Koc) characteristics. These parameters may vary for the same pesticide from geographic site-to-site and with soil depth. The interactions that normally occur between pesticides and dissolved organic matter (DOM) or WDC are yet other factors that may complicate pesticide leaching behavior.The soil mobility of pesticides is normally tested both in the laboratory and in the field. Lab studies are initially performed to give researchers a preliminary appraisal of the relative mobility of a pesticide. Later, field lysimeter studies can be performed to provide more natural leaching conditions that emulate the actual field use pattern. Lysimeter studies give the most reliable information on the leaching behavior of a pesticide under field conditions, but these studies are time-consuming and expensive and cannot be performed everywhere. It is for this reason that the laboratory soil column leaching approach is commonly utilized to profile the mobility of a pesticide,and appraise how it behaves in different soils, and relative to other pesticides.Because the soil structure is chemically and physically heterogenous, different pesticide tests may produce variable DT50 and Koc values; therefore, initial pesticide mobility testing is undertaken in homogeneously packed columns that contain two or more soils and are eluted at constant flow rates. Such studies are done in duplicate and utilize a conservative tracer element. By fitting an appropriate mathematical model to the breakthrough curve of the conservative tracer selected,researchers determine key mobility parameters, such as pore water velocity, the column-specific dispersion coefficient, and the contribution of non equilibrium transport processes. Such parameters form the basis for estimating the probable transport and degradation rates that will be characteristic of the tested pesticide. Researchers also examine how a pesticide interacts with soil DOM and WDC, and what contribution from facilitated transport to mobility is made as a result of the effects of

Katagi, Toshiyuki

2013-01-01

337

Computational Fluid Dynamics Simulation of Structured Packing Scott A. Owens, Michael R. Perkins, and R. Bruce Eldridge*  

E-print Network

in significant cost savings. Most distillation columns are heated by steam produced by fossil fuels. Reducing the consump- tion of these expensive fuels will yield immediate cost savings and will have the added benefit, automotive, and marine industries to enhance perform- ance, decrease design costs, and accelerate

Eldridge, R. Bruce

338

Five Points on Columns  

PubMed Central

Column,” like “gene,” has both conceptual and linguistic shortcomings. The simple question “what is a column” is not easy to answer and the word itself is not easy to replace. In the present article, I have selected five points, in no way comprehensive or canonical, but which may nevertheless serve as a prompt and aid for further discussions and re-evaluation. These are: that anatomical columns are not solid structures, that they are part of locally interdigitating systems, that any delimited column also participates in a widely distributed network, that columns are not an obligatory cortical feature, and that columns (as “modules”) occur widely in the brain in non-cortical structures. I focus on the larger scale macrocolumns, mainly from an anatomical perspective. My position is that cortical organization is inherently dynamic and likely to incorporate multiple processing styles. One can speculate that the distributed mappings within areas like piriform cortex may resemble at least one mode of neocortical processing strategy. PMID:20589097

Rockland, Kathleen S.

2010-01-01

339

Blood purification therapies using dextran sulfate cellulose columns Liposorber and Selesorb.  

PubMed

Liposorber is a column used for plasma purification that adsorbs low-density lipoproteins with high selectivity, while Selesorb is a column that selectively adsorbs anti-DNA antibodies, anticardiolipin antibodies, and immune complexes. Both columns are packed with carriers, where a dextran sulfate ligand is bound to porous cellulose beads. Liposorber is used to treat familial hypercholesterolemia (FH), peripheral arterial disease (PAD), and focal segmental glomerulosclerosis (FGS): Selesorb is used to treat systemic lupus erythematosus (SLE). Treatment utilizing both columns is being used effectively in patients with refractory disease that is resistant to pharmacotherapy. PMID:12921119

Asahi, Takashi; Yamamoto, Takashi; Kutsuki, Hidetoshi

2003-02-01

340

HEXAHYDRO-1,3,5-TRINITRO-1,3,5-TRIAZINE (RDX) DEGRADATION IN BIOLOGICALLY-ACTIVE IRON COLUMNS  

E-print Network

HEXAHYDRO-1,3,5-TRINITRO-1,3,5-TRIAZINE (RDX) DEGRADATION IN BIOLOGICALLY-ACTIVE IRON COLUMNS BYUNG iron barriers to treat groundwater contamination by RDX. Three columns were packed with iron filings (Fe0) between soil and sand layers, and were fed continuously with unlabeled plus 14C-labeled RDX

Alvarez, Pedro J.

341

In flow activation of diol-silica with cyanogen bromide and triethylamine for preparing high-performance affinity chromatographic columns.  

PubMed

A new coupling strategy using pre-packed diol-silica supports to obtain affinity columns for high-performance affinity chromatography (HPAC) is described. These columns were prepared by "in flow" activation in which solutions containing anhydrous solutions of CNBr and triethylamine are separately pumped to a mixer and then onto a pre-packed diol-silica column. Recycling the amino ligand to be coupled several times over the activated silica diol columns results in ligand immobilization. DNA (the Op 1 lac operator), 6-aminohexyl-Cibacron and a peptide (melittin) were all successfully "in flow" coupled to freshly activated columns. Methods for CNBr activation of pre-packed diol-silica column were developed for one, two or three pump HPLC systems. The supports were successfully used for the HPAC purification of a Lac repressor-beta-galactosidase fusion protein, alcohol dehydrogenase, and calmodulin. Columns prepared by in flow activation/coupling procedures were shown to be stable for at least 14 months. Also, in flow activated silica columns could be stored in anhydrous acetone for at least 3 months prior to coupling. Our experiments with these affinity ligand columns (DNA-silica, aminohexyl-Cibacron F3GA-silica, and melittin-silica), suggests that this is a very successful coupling protocol for producing a variety of HPAC columns. PMID:12564672

Jurado, Luis A; Jarrett, Harry W

2003-01-10

342

Analysis of tissue free fatty acids isolated by aminopropyl bonded-phase columns.  

PubMed

Gas chromatographic analysis revealed that polyunsaturated fatty acids such as arachidonic acid and total tissue free fatty acids isolated from an aminopropyl bonded-phase column yield a two- to three-fold higher recovery of arachidonic acid as compared to those isolated from thin-layer chromatographic plates. This method was further improved by packing the aminopropyl bonded phase in glass columns, since the glass column significantly eliminated the other contaminants (from polypropylene columns) coeluting with fatty acids in both a neutral lipid thin-layer chromatographic system and on a 5% DEGS-PS column of gas chromatographic analysis. In aminopropyl bonded-phase columns, the standard triglycerides and phospholipids were completely separated from free fatty acids as judged by gas chromatographic analysis. These results warrant the use of an aminopropyl bonded-phase column for the isolation of free fatty acids to obtain better recovery of polyunsaturated fatty acids. PMID:3145937

Prasad, M R; Jones, R M; Young, H S; Kaplinsky, L B; Das, D K

1988-07-15

343

Fixed Packed Bed Reactors in Reduced Gravity  

NASA Technical Reports Server (NTRS)

We present experimental data on flow pattern transitions, pressure drop and flow characteristics for cocurrent gas-liquid flow through packed columns in microgravity. The flow pattern transition data indicates that the pulse flow regime exists over a wider range of gas and liquid flow rates under microgravity conditions compared to 1-g and the widely used Talmor map in 1-g is not applicable for predicting the transition boundaries. A new transition criterion between bubble and pulse flow in microgravity is proposed and tested using the data. Since there is no static head in microgravity, the pressure drop measured is the true frictional pressure drop. The pressure drop data, which has much smaller scatter than most reported 1-g data clearly shows that capillary effects can enhance the pressure drop (especially in the bubble flow regime) as much as 200% compared to that predicted by the single phase Ergun equation. The pressure drop data are correlated in terms of a two-phase friction factor and its dependence on the gas and liquid Reynolds numbers and the Suratman number. The influence of gravity on the pulse amplitude and frequency is also discussed and compared to that under normal gravity conditions. Experimental work is planned to determine the gas-liquid and liquid-solid mass transfer coefficients. Because of enhanced interfacial effects, we expect the gas-liquid transfer coefficients kLa and kGa (where a is the gas-liquid interfacial area) to be higher in microgravity than in normal gravity at the same flow conditions. This will be verified by gas absorption experiments, with and without reaction in the liquid phase, using oxygen, carbon dioxide, water and dilute aqueous amine solutions. The liquid-solid mass transfer coefficient will also be determined in the bubble as well as the pulse flow regimes using solid benzoic acid particles in the packing and measuring their rate of dissolution. The mass transfer coefficients in microgravity will be compared to those in normal gravity cocurrent flow to determine the mass transfer enhancement and propose new mass transfer correlations for two-phase gas-liquid flows through packed beds in microgravity.

Motil, Brian J.; Balakotaiah, Vemuri; Kamotani, Yasuhiro; McCready, Mark J.

2004-01-01

344

Comparison of Advanced Distillation Control Methods, Final Technical Report  

SciTech Connect

Detailed dynamic simulations of three industrial distillation columns (a propylene/propane splitter, a xylene/toluene column, and a depropanizer) have been used to evaluate configuration selections for single-ended and dual-composition control, as well as to compare conventional and advanced control approaches. In addition, a simulator of a main fractionator was used to compare the control performance of conventional and advanced control. For each case considered, the controllers were tuned by using setpoint changes and tested using feed composition upsets. Proportional Integral (PI) control performance was used to evaluate the configuration selection problem. For single ended control, the energy balance configuration was found to yield the best performance. For dual composition control, nine configurations were considered. It was determined that the use of dynamic simulations is required in order to identify the optimum configuration from among the nine possible choices. The optimum configurations were used to evaluate the relative control performance of conventional PI controllers, MPC (Model Predictive Control), PMBC (Process Model-Based Control), and ANN (Artificial Neural Networks) control. It was determined that MPC works best when one product is much more important than the other, while PI was superior when both products were equally important. PMBC and ANN were not found to offer significant advantages over PI and MPC. MPC was found to outperform conventional PI control for the main fractionator. MPC was applied to three industrial columns: one at Phillips Petroleum and two at Union Carbide. In each case, MPC was found to significantly outperform PI controls. The major advantage of the MPC controller is its ability to effectively handle a complex set of constraints and control objectives.

Dr. James B. Riggs

2000-11-30

345

[Electroflotation packing of mycelial wastes].  

PubMed

Data on testing a pilot plant for electroflotative packing of mycelial wastes are presented. Both the mycelial wastes and their mixtures were used. Concentration of dry substances raged from 3.5 to 131 g/l. The process was performed with varying flow density and consumption rate of the liquid supplied to the plant. Insoluble magnetite and ruthenium oxide anodes were used. The moister content in the packed phase was 81-97.5 per cent. The study provided specification of the process technological parameters and investigation of the flotator hydroulic characteristics. PMID:2751387

Nikolaev, V B; Karpukhin, V F; Zav'ialova, E V; Faingol'd, Z L

1989-04-01

346

Efficient algorithms for orthogonal packing problems  

NASA Astrophysics Data System (ADS)

The NP complete problem of the orthogonal packing of objects of arbitrary dimension is considered in the general form. A new model for representing objects in containers is proposed that ensures the fast design of an orthogonal packing. New heuristics for the placement of orthogonal packing are proposed. A single-pass heuristic algorithm and a multimethod genetic algorithm are developed that optimize an orthogonal packing solution by increasing the packing density. Numerical experiments for two- and three-dimensional orthogonal packing problems are performed.

Chekanin, A. V.; Chekanin, V. A.

2013-10-01

347

HEAT TRANSFER ANALYSIS FOR ION-EXCHANGE COLUMN SYSTEM  

SciTech Connect

Models have been developed to simulate the thermal characteristics of Crystalline Silicotitanate (CST) ion exchange media fully loaded with radioactive cesium in a column configuration and distributed within a waste storage tank. This work was conducted to support the Small Column Ion Exchange (SCIX) program which is focused on processing dissolved, high-sodium salt waste for the removal of specific radionuclides (including Cs-137, Sr-90, and actinides) within a High Level Waste (HLW) storage tank at the Savannah River Site. The SCIX design includes CST columns inserted and supported in the tank top risers for cesium removal. Temperature distributions and maximum temperatures across the column were calculated with a focus on process upset conditions. A two-dimensional computational modeling approach for the in-column ion-exchange domain was taken to include conservative, bounding estimates for key parameters such that the results would provide the maximum centerline temperatures achievable under the design configurations using a feed composition known to promote high cesium loading on CST. The current full-scale design for the CST column includes one central cooling pipe and four outer cooling tubes. Most calculations assumed that the fluid within the column was stagnant (i.e. no buoyancy-induced flow) for a conservative estimate. A primary objective of these calculations was to estimate temperature distributions across packed CST beds immersed in waste supernate or filled with dry air under various accident scenarios. Accident scenarios evaluated included loss of salt solution flow through the bed, inadvertent column drainage, and loss of active cooling in the column. The modeling results demonstrate that the baseline design using one central and four outer cooling tubes provides a highly efficient cooling mechanism for reducing the maximum column temperature.

Lee, S.; King, W.

2011-05-23

348

Eruption column physics  

SciTech Connect

In this paper the author focuses on the fluid dynamics of large-scale eruption columns. The dynamics of these columns are rooted in multiphase flow phenomena, so a major part of the paper sets up a foundation on that topic that allows one to quickly assess the inherent assumptions made in various theoretical and experimental approaches. The first part is centered on a set of complex differential equations that describe eruption columns, but the focus is on a general understanding of important physical processes rather than on the mathematics. The author discusses briefly the relative merits and weaknesses of different approaches, emphasizing that the largest advances in understanding are made by combining them. He then focuses on dynamics of steady eruption columns and then on transient phenomena. Finally he briefly reviews the effects of varying behavior of the ambient medium through which an eruption column moves. These final sections will emphasize concepts and a qualitative understanding of eruption dynamics. This paper relies on principles of continuum mechanics and transport processes but does not go into detail on the development of those principles. 36 refs., 36 figs., 3 tabs.

Valentine, G.A.

1997-03-01

349

Computation of multicomponent distillation processes by the Newton-Raphson method using an implicit function  

SciTech Connect

A new iterative method is presented for the rigorous simulation of multicomponent distillation processes using the Newton-Raphson method to solve the simultaneous equations, which is characterized by the use of the liquid compositions as the independent variables and analytical equations for evaluating the partial derivatives, with the vapor compositions and temperatures as the dependent variables. The analytical equations for the partial derivatives of the vapor compositions with respect to the liquid compositions are derived, using the implicit-function theorem. The advantages of the method are that a numerical differentiation of the partial derivatives is unnecessary, as is normalization of the liquid compositions. The method has excellent convergence characteristics when applied to 10 typical distillation columns of complicated structure.

Shimizu, K. (Nippon Synthetic Chem. Ind. Co., Ltd., Osaka (Japan)); Sayama, H.; Kameyama, Y.; Suzuki, K. (Okayama Univ. (Japan))

1993-01-01

350

Students & Mental Health Resource Pack  

E-print Network

Students & Mental Health Resource Pack Produced by - www.rethink.org/at-ease/ SHEFFIELD EARLY is severe mental illness? 1.4 Treatment and prognosis What is mental health awareness? 2.1 Introduction 2 for students with experience of mental health problems 5.1 Introduction 5.2 Pre-entry guidance for students 5

Stevenson, Mark

351

Oil Spill! ClassPack  

NSDL National Science Digital Library

Using Picture-Perfect Science Lessons in your classroom is easier than ever! NSTA's ClassPacks, each sufficient for a class of 28 students, are lesson-specific collections of materials--an unmatched time-saver and a great deal. This Cla

2010-04-21

352

Wiggling Worms ClassPack  

NSDL National Science Digital Library

Using More Picture-Perfect Science Lessons: Using Children's Books to Guide Inquiry, K-4 in your classroom is easier than ever! NSTA's ClassPacks, each sufficient for a class of 28 students, are lesson-specific collections of materials--an unmatche

2010-04-23

353

Packing Schemes for Gang Scheduling  

Microsoft Academic Search

. Jobs that do not require all processors in the system can bepacked together for gang scheduling. We examine accounting traces fromseveral parallel computers to show that indeed many jobs have small sizesand can be packed together. We then formulate a number of such packingalgorithms, and evaluate their effectiveness using simulations based onour workload study. The results are that two

Dror G. Feitelson

1996-01-01

354

Wire and Packing Tape Sandwiches  

ERIC Educational Resources Information Center

In this article, the author describes how students can combine craft wire with clear packing tape to create a two-dimensional design that can be bent and twisted to create a three-dimensional form. Students sandwich wire designs between two layers of tape. (Contains 1 online resource.)

Rabinowitz, Sandy

2009-01-01

355

Fundamental Studies on Two-Phase Gas-Liquid Flows Through Packed Beds in Microgravity  

NASA Astrophysics Data System (ADS)

In the typical operation of a packed-bed reactor, gas and liquid flow simultaneously through a fixed bed of solid particles. Depending on the application, the particles can be of various shapes and sizes and provide for intimate contact and high rates of transport between the phases needed to sustain chemical or biological reactions. The packing may also serve as either a catalyst or as a support for growing biological material. NASA has flown two of these packed-bed systems in a microgravity environment with limited or no success. The goal of this research is to develop models (with scale-up capability) needed for the design of the physicochemical equipment to carry out these unit operations in microgravity. New insight will also lead to improvements in normal gravity operations. Our initial experiment was flown using an existing KC-135 two-phase flow rig with a modified test section. The test section is a clear polycarbonate rectangular column with a depth of 2.54 cm, a width of 5.08 cm, and 60 cm long. The column was randomly packed with spherical glass beads by slowly dropping the beads into the bed. Even though care was taken in handling the column after it was filled with packing, the alternating high and low gravity cycles with each parabola created a slightly tighter packed bed than is typically reported for this type. By the usual method of comparing the weight difference of a completely dry column versus a column filled with water, the void fraction was found to be .345 for both sizes of beads used. Five flush mounted differential pressure transducers are spaced at even intervals with the first location 4 cm from the inlet port and the subsequent pressure transducers spaced at 13 cm intervals along the column. Differential pressure data was acquired at 1000 Hz to adequately observe pulse formation and characteristics. Visual images of the flow were recorded using a high-speed SVHS system at 500 frames per second. Over 250 different test conditions were evaluated along with a companion set of tests in normal gravity. The flow rates, fluid properties and packing properties were selected to provide a range of several orders-of-magnitude for the important dimensionless parameters. Additional information is included in the original extended abstract.

Balakotaiah, Vemuri; McCready, Mark J.; Motil, Brian J.

2002-11-01

356

Fundamental Studies on Two-Phase Gas-Liquid Flows Through Packed Beds in Microgravity  

NASA Technical Reports Server (NTRS)

In the typical operation of a packed-bed reactor, gas and liquid flow simultaneously through a fixed bed of solid particles. Depending on the application, the particles can be of various shapes and sizes and provide for intimate contact and high rates of transport between the phases needed to sustain chemical or biological reactions. The packing may also serve as either a catalyst or as a support for growing biological material. NASA has flown two of these packed-bed systems in a microgravity environment with limited or no success. The goal of this research is to develop models (with scale-up capability) needed for the design of the physicochemical equipment to carry out these unit operations in microgravity. New insight will also lead to improvements in normal gravity operations. Our initial experiment was flown using an existing KC-135 two-phase flow rig with a modified test section. The test section is a clear polycarbonate rectangular column with a depth of 2.54 cm, a width of 5.08 cm, and 60 cm long. The column was randomly packed with spherical glass beads by slowly dropping the beads into the bed. Even though care was taken in handling the column after it was filled with packing, the alternating high and low gravity cycles with each parabola created a slightly tighter packed bed than is typically reported for this type. By the usual method of comparing the weight difference of a completely dry column versus a column filled with water, the void fraction was found to be .345 for both sizes of beads used. Five flush mounted differential pressure transducers are spaced at even intervals with the first location 4 cm from the inlet port and the subsequent pressure transducers spaced at 13 cm intervals along the column. Differential pressure data was acquired at 1000 Hz to adequately observe pulse formation and characteristics. Visual images of the flow were recorded using a high-speed SVHS system at 500 frames per second. Over 250 different test conditions were evaluated along with a companion set of tests in normal gravity. The flow rates, fluid properties and packing properties were selected to provide a range of several orders-of-magnitude for the important dimensionless parameters. Additional information is included in the original extended abstract.

Balakotaiah, Vemuri; McCready, Mark J.; Motil, Brian J.

2002-01-01

357

Preprototype Vapor Compression Distillation Subsystem development  

NASA Technical Reports Server (NTRS)

Vapor Compression Distillation (VCD) has evolved as the most promising approach to reclaim potable water from wastewater for future long-term manned space missions. Life Systems, Inc. (LSI), working with NASA, has developed a preprototype Vapor Compression Distillation Subsystem (VCDS) which processes wastewater at 1.4 kg/h. The preprototype unit weighs 143 kg, occupies a volume of 0.47 cu m, and will reclaim 96 percent of the available wastewater. This unit has been tested by LSI and is scheduled for further testing at NASA-JSC. This paper presents the preprototype VCDS design, configuration, performance data, test results and flight system projections.

Thompson, C. D.; Ellis, G. S.; Schubert, F. H.

1981-01-01

358

Preparation and evaluation of molecularly imprinted polymer liquid chromatography column for the separation of Cathine enantiomers  

PubMed Central

In this study molecular imprinting technology was employed to prepare a specific affinity sorbent for the resolution of Cathine, a chiral drug product. The molecularly imprinted polymer (MIP) was prepared by non-covalent molecular imprinting with either (+) or (?)-Cathine (threo-2-amino-1-hydroxy-1-phenyl propane; norpseudoephedrine) as the template. Methacrylic acid and ethylene glycol di-methacrylate were copolymerized in the presence of the template molecule. The bulk polymerization was carried out in chloroform with 2,2?-azobisisobutyronitrile as the initiator, at 5 °C and under UV radiation. The resulting MIP was ground into powders, which were slurry packed into analytical columns. After removal of template molecules, the MIP-packed columns were found to be effective for the resolution of (±)-Cathine racemates. The separation factor for the enantiomers ranged between 1.5 and 2.4 when the column was packed with MIP prepared with (+)-Cathine as the template. A separation factor ranging from 1.6 to 2.9 could be achieved from the column packed with MIP, prepared with (?)-Cathine as the template. Although the separation factor was higher with that previously obtained from reversed-phase column chromatography following derivatization with a chiral agent, elution peaks were broader due to the heterogeneity of binding sites on MIP particles and the possible non-specific interaction. PMID:23960776

Balamurugan, Krishnamoorthy; Gokulakrishnan, Kannan; Prakasam, Tangirala

2011-01-01

359

Preparation and evaluation of molecularly imprinted polymer liquid chromatography column for the separation of Cathine enantiomers.  

PubMed

In this study molecular imprinting technology was employed to prepare a specific affinity sorbent for the resolution of Cathine, a chiral drug product. The molecularly imprinted polymer (MIP) was prepared by non-covalent molecular imprinting with either (+) or (-)-Cathine (threo-2-amino-1-hydroxy-1-phenyl propane; norpseudoephedrine) as the template. Methacrylic acid and ethylene glycol di-methacrylate were copolymerized in the presence of the template molecule. The bulk polymerization was carried out in chloroform with 2,2'-azobisisobutyronitrile as the initiator, at 5 °C and under UV radiation. The resulting MIP was ground into powders, which were slurry packed into analytical columns. After removal of template molecules, the MIP-packed columns were found to be effective for the resolution of (±)-Cathine racemates. The separation factor for the enantiomers ranged between 1.5 and 2.4 when the column was packed with MIP prepared with (+)-Cathine as the template. A separation factor ranging from 1.6 to 2.9 could be achieved from the column packed with MIP, prepared with (-)-Cathine as the template. Although the separation factor was higher with that previously obtained from reversed-phase column chromatography following derivatization with a chiral agent, elution peaks were broader due to the heterogeneity of binding sites on MIP particles and the possible non-specific interaction. PMID:23960776

Balamurugan, Krishnamoorthy; Gokulakrishnan, Kannan; Prakasam, Tangirala

2012-01-01

360

Reducing CO2 emissions and energy consumption of heat-integrated distillation systems.  

PubMed

Distillation systems are energy and power intensive processes and contribute significantly to the greenhouse gases emissions (e.g. carbon dioxide). Reducing CO2 emissions is an absolute necessity and expensive challenge to the chemical process industries in orderto meetthe environmental targets as agreed in the Kyoto Protocol. A simple model for the calculation of CO2 emissions from heat-integrated distillation systems is introduced, considering typical process industry utility devices such as boilers, furnaces, and turbines. Furnaces and turbines consume large quantities of fuels to provide electricity and process heats. As a result, they produce considerable amounts of CO2 gas to the atmosphere. Boilers are necessary to supply steam for heating purposes; besides, they are also significant emissions contributors. The model is used in an optimization-based approach to optimize the process conditions of an existing crude oil atmospheric tower in order to reduce its CO2 emissions and energy demands. It is also applied to generate design options to reduce the emissions from a novel internally heat-integrated distillation column (HIDiC). A gas turbine can be integrated with these distillation systems for larger emissions reduction and further energy savings. Results show that existing crude oil installations can save up to 21% in energy and 22% in emissions, when the process conditions are optimized. Additionally, by integrating a gas turbine, the total emissions can be reduced further by 48%. Internal heat-integrated columns can be a good alternative to conventional heat pump and other energy intensive close boiling mixtures separations. Energy savings can reach up to 100% with respect to reboiler heat requirements. Emissions of these configurations are cut down by up to 83%, compared to conventional units, and by 36%, with respect to heat pump alternatives. Importantly, cost savings and more profit are gained in parallel to emissions minimization. PMID:16190250

Gadalla, Mamdouh A; Olujic, Zarko; Jansens, Peter J; Jobson, Megan; Smith, Robin

2005-09-01

361

Fluid mechanics of distillation trays (II): Prediction of flow fields on some practically important sieve trays  

SciTech Connect

Separation processes account for 6% of the annual US energy expenditure, 50% of which is consumed by distillation alone. Therefore, it is not too surprising that distillation, the work horse of the chemical process industry, is under attack by emerging technologies based on membranes and adsorption, whose proponents claim enormous potential savings in energy expenditures. Moreover, the massive scale of use plus the energy intensiveness implies that even small improvements in the efficiency of distillation processes can result in large gains in energy savings. Such improvements can come from developing fundamental understanding of the fluid mechanics of tray columns, which has heretofore been lacking and is the subject of this paper. The flow on a distillation tray is governed by the equations of mass and momentum conservation in three-dimensions. These equations are reduced here to a set of two-dimensional equations by averaging them across the depth of the fluid film flowing across the tray. The depth-averaged equations are then solved by a Galerkin/finite element technique. The evolution of film height and flow fields are determined for three types of trays that are commonly found in the laboratory and in actual plants: rectangular trays, circular trays, and so-called race track trays. Sample results include development and growth of eddies of zones of recirculation on various types of trays, variation of film height with position on a tray, and effect of tray geometry, flow rate, and physical properties on tray holdup. Occurrence of eddies and large height variations on trays can have detrimental consequences in vapor-liquid contacting operations. Therefore, the new rigorous computations should prove indispensable in developing column designs that avoid or minimize them.

Basaran, O.A. [Oak Ridge National Laboratory, TN (United States); Wohlhuter, F.K. [Univ. of Tennessee, Knoxville, TN (United States)

1995-04-01

362

Fiber separation from distillers dried grains with solubles using a larger elutriation apparatus and use of fiber as a feedstock for corn fiber gum production  

Technology Transfer Automated Retrieval System (TEKTRAN)

In an earlier study, the combination of sieving and elutriation (air flow) was found to be effective in separating fiber from distillers dried grains with solubles (DDGS); the elutriation column diameter used was 63 mm. Larger quantities of fractions were needed for carrying out studies on producti...

363

Efficiency of supercritical fluid chromatography columns in different thermal environments.  

PubMed

The efficiency of a packed column eluted with supercritical carbon dioxide at 323K and outlet pressures from 90 to 150bar was studied with the column in two different thermal environments. The 150mm×2.0mm ID stainless steel column was packed with spherical 5-?m porous silica particles with a covalently bonded nonpolar stationary phase, and the test solutes were normal alkanes. When operated in a convective air bath the column exhibited severe efficiency losses when its outlet pressure was below 120bar. The efficiency of the same column enclosed in a shell made of foam insulation was restored at low outlet pressures down to 100bar. The van Deemter plots showed an abnormal dependence of the plate height (HETP) on the flow rate at low outlet pressures, exhibiting a maximum in the HETP at flow rates around 1mL/min and a 20-bar pressure drop. The large efficiency losses at low outlet pressures are due to radial temperature gradients associated with enthalpic expansion and cooling of the mobile phase. The separations were simulated by a numerical model that accounts for axial and radial gradients in the temperature and density along the column. The abnormal van Deemter plots arise from competing processes affecting the radial distribution of the solute migration velocity along the column. The negative impact on efficiency is greatest when the density profile of the mobile phase along the column is close to the critical isopycnic line. The efficiency improves at increased flow rates because of increased cooling at larger pressure drops and increased density along the entire length of the column. The model predicts the unusual trends in the van Deemter plots, but the calculated results at low outlet pressures are strongly influenced by small variations in the porosity distribution in the column, limiting the accuracy of the predicted HETP values. In spite of these difficulties, the model has enabled a detailed analysis of the effects of temperature, pressure and flow rate on the thermal properties of the mobile phase, and their impact on the radial distribution of the solute velocities along the column. This work provides a better appreciation of the factors that cause excess efficiency loss at low outlet pressures, a phenomenon that lacked a convincing explanation for over 40 years. Finally, a simplified form of the model, which ignores the radial gradients, provided accurate results only at the highest outlet pressure. Calculations done by the simplified model are much faster, and it can be recommended for simulation of SFC processes at sufficiently high outlet pressures. PMID:23598158

Kaczmarski, Krzysztof; Poe, Donald P; Tarafder, Abhijit; Guiochon, Georges

2013-05-24

364

Physical extraction of microorganisms from water-saturated, packed sediment.  

PubMed

Microbial characterization of aquifers should include samples of both suspended and attached microorganisms (biofilms). We investigated the effect of shear, sonication, and heat on the extraction of microorganisms from water-saturated, packed sediment columns containing established biofilms. Shear was studied by increasing flow velocity of the column eluent, sonication by treating the columns with ultrasound at different power levels, and heat by warming up the column eluent to different temperatures. Effluent cell concentrations were used as a measure of extraction efficiency. Dissolved organic carbon and adenosine tri-phosphate (ATP) concentrations were used to corroborate cell-extraction results. Additionally, ATP was used as an indicator of cell-membrane integrity. Extraction quality was determined by comparing terminal-restriction fragment length polymorphism (T-RFLP) profiles of extracted bacterial communities with destructively sampled sediment-community profiles. Sonication and heat increased the extraction efficiency up to 200-fold and yielded communities comparable to the sediment community. These treatments showed high potential for in-situ application in aquifers. PMID:24961067

Ugolini, Fabio; Schroth, Martin H; Bürgmann, Helmut; Zeyer, Josef

2014-05-01

365

7 CFR 958.16 - Pack.  

Code of Federal Regulations, 2012 CFR

...Orders; Fruits, Vegetables, Nuts), DEPARTMENT OF AGRICULTURE ONIONS GROWN IN CERTAIN DESIGNATED COUNTIES IN IDAHO, AND MALHEUR...Definitions § 958.16 Pack. Pack means a quantity of onions in any type of container and which falls within specific...

2012-01-01

366

7 CFR 945.15 - Pack.  

Code of Federal Regulations, 2010 CFR

...and Orders; Fruits, Vegetables, Nuts), DEPARTMENT OF AGRICULTURE IRISH POTATOES GROWN IN CERTAIN DESIGNATED COUNTIES IN IDAHO, AND MALHEUR COUNTY, OREGON Order Regulating Handling Definitions § 945.15 Pack. Pack means a quantity...

2010-01-01

367

7 CFR 966.11 - Pack.  

Code of Federal Regulations, 2010 CFR

...Nuts), DEPARTMENT OF AGRICULTURE TOMATOES GROWN IN FLORIDA Order Regulating... Pack means any of the packs of tomatoes as defined and set forth in the United States Standards for Fresh Tomatoes issued by the United States...

2010-01-01

368

7 CFR 966.11 - Pack.  

Code of Federal Regulations, 2014 CFR

...NUTS), DEPARTMENT OF AGRICULTURE TOMATOES GROWN IN FLORIDA Order Regulating... Pack means any of the packs of tomatoes as defined and set forth in the United States Standards for Fresh Tomatoes issued by the United States...

2014-01-01

369

7 CFR 966.11 - Pack.  

Code of Federal Regulations, 2013 CFR

...NUTS), DEPARTMENT OF AGRICULTURE TOMATOES GROWN IN FLORIDA Order Regulating... Pack means any of the packs of tomatoes as defined and set forth in the United States Standards for Fresh Tomatoes issued by the United States...

2013-01-01

370

7 CFR 966.11 - Pack.  

Code of Federal Regulations, 2012 CFR

...Nuts), DEPARTMENT OF AGRICULTURE TOMATOES GROWN IN FLORIDA Order Regulating... Pack means any of the packs of tomatoes as defined and set forth in the United States Standards for Fresh Tomatoes issued by the United States...

2012-01-01

371

7 CFR 966.11 - Pack.  

Code of Federal Regulations, 2011 CFR

...Nuts), DEPARTMENT OF AGRICULTURE TOMATOES GROWN IN FLORIDA Order Regulating... Pack means any of the packs of tomatoes as defined and set forth in the United States Standards for Fresh Tomatoes issued by the United States...

2011-01-01

372

On the kinetics of pack aluminization  

NASA Technical Reports Server (NTRS)

A theory of pack aluminization has been formulated by combining gaseous and solid-state diffusion rates. This theory relates the surface composition of the coating and therefore, in principle, the phase morphology and the growth rate of the coating, to pack operating parameters such as pack aluminum density, type of activator, temperature and others. Experimental data on the aluminization of unalloyed nickel in pure aluminum packs obtained to date are in good agreement with the predictions of the theory.

Gupta, B. K.; Sarkhel, A. K.; Seigle, L. L.

1975-01-01

373

27 CFR 17.151 - Use of distilled spirits.  

Code of Federal Regulations, 2010 CFR

...2010-04-01 false Use of distilled spirits. 17.151 Section 17.151 Alcohol...LIQUORS DRAWBACK ON TAXPAID DISTILLED SPIRITS USED IN MANUFACTURING NONBEVERAGE PRODUCTS Claims for Drawback Spirits Subject to Drawback § 17.151...

2010-04-01

374

40 CFR 721.9635 - Terpene residue distillates.  

Code of Federal Regulations, 2014 CFR

...forth as follows: § 721.9635 Terpenes and terpenoids, limonene fraction, distn. residues, distillates. (a) Chemical...The chemical substance identified as terpenes and terpenoids, limonene fraction, distn. residues, distillates (PMN...

2014-07-01

375

40 CFR 1065.703 - Distillate diesel fuel.  

Code of Federal Regulations, 2013 CFR

...ENGINE-TESTING PROCEDURES Engine Fluids, Test Fuels...703 Distillate diesel fuel. (a) Distillate diesel fuels for testing...adequate for proper engine operation. (b...three grades of #2 diesel fuel...

2013-07-01

376

40 CFR 1065.703 - Distillate diesel fuel.  

Code of Federal Regulations, 2012 CFR

...ENGINE-TESTING PROCEDURES Engine Fluids, Test Fuels...703 Distillate diesel fuel. (a) Distillate diesel fuels for testing...adequate for proper engine operation. (b...three grades of #2 diesel fuel...

2012-07-01

377

40 CFR 1065.703 - Distillate diesel fuel.  

Code of Federal Regulations, 2010 CFR

...ENGINE-TESTING PROCEDURES Engine Fluids, Test Fuels...703 Distillate diesel fuel. (a) Distillate diesel fuels for testing...adequate for proper engine operation. (b...three grades of #2 diesel fuel...

2010-07-01

378

40 CFR 1065.703 - Distillate diesel fuel.  

Code of Federal Regulations, 2011 CFR

...ENGINE-TESTING PROCEDURES Engine Fluids, Test Fuels...703 Distillate diesel fuel. (a) Distillate diesel fuels for testing...adequate for proper engine operation. (b...three grades of #2 diesel fuel...

2011-07-01

379

40 CFR 1065.703 - Distillate diesel fuel.  

Code of Federal Regulations, 2014 CFR

...ENGINE-TESTING PROCEDURES Engine Fluids, Test Fuels...703 Distillate diesel fuel. (a) Distillate diesel fuels for testing...adequate for proper engine operation. (b...three grades of #2 diesel fuel...

2014-07-01

380

Columns in Clay  

ERIC Educational Resources Information Center

This article describes a clay project for students studying Greece and Rome. It provides a wonderful way to learn slab construction techniques by making small clay column capitols. With this lesson, students learn architectural vocabulary and history, understand the importance of classical architectural forms and their influence on today's…

Leenhouts, Robin

2010-01-01

381

Chemical composition of distillers grains, a review  

Technology Transfer Automated Retrieval System (TEKTRAN)

In recent years, increasing demand for ethanol as a fuel additive and decreasing dependency on fossil fuels have resulted in a dramatic increase in the amount of grains used for ethanol production. Dry-grind is the major process, resulting in distillers dried grains with solubles (DDGS) as a major ...

382

PPMCSA Presentation on Winter Distillate Outlook  

NSDL National Science Digital Library

This presentation on the Winter Distillate Outlook was created for the PPMCSA Meeting and Trade Show of this year. It gives basic information and forecasts on the prices of a variety of energy sources through a collection of slides and accompanying notes.

383

Distillation Calculations with a Programmable Calculator.  

ERIC Educational Resources Information Center

Describes a three-step approach for teaching multicomponent distillation to undergraduates, emphasizing patterns of distribution as an aid to understanding the separation processes. Indicates that the second step can be carried out by programmable calculators. (A more complete set of programs for additional calculations is available from the…

Walker, Charles A.; Halpern, Bret L.

1983-01-01

384

Acetylation of corn distillers dried grains  

Microsoft Academic Search

This paper shows that acidic conditions provide substantially higher % acetyl content, intrinsic viscosity and thermoplasticity even at low ratios of acetic anhydride and catalyst concentrations compared to using alkaline conditions for acetylation of oil-and-zein-free distillers dried grains with solubles (DDGS). Conventional methods of carbohydrate and protein acetylation are unsuitable for acetylating DDGS which is a mixture of carbohydrates and

Narendra Reddy; Chunyan Hu; Kelu Yan; Yiqi Yang

2011-01-01

385

Improved micromachined column design and fluidic interconnects for programmed high-temperature gas chromatography separations.  

PubMed

This work focuses on the development and experimental evaluation of micromachined chromatographic columns for use in a commercial gas chromatography (GC) system. A vespel/graphite ferrule based compression sealing technique is presented using which leak-proof fluidic interconnection between the inlet tubing and the microchannel was achieved. This sealing technique enabled separation at temperatures up to 350°C on a ?GC column. This paper reports the first high-temperature separations in microfabricated chromatographic columns at these temperatures. A 2m microfabricated column using a double Archimedean spiral design with a square cross-section of 100?m×100?m has been developed using silicon microfabrication techniques. The microfabricated column was benchmarked against a 2m 100?m diameter commercial column and the performance between the two columns was evaluated in tests performed under identical conditions. High temperature separations of simulated distillation (ASTM2887) and polycyclic aromatic hydrocarbons (EPA8310) were performed using the ?GC column in temperature programmed mode. The demonstrated ?GC column along with the high temperature fixture offers one more solution toward potentially realizing a portable ?GC device for the detection of semi-volatile environmental pollutants and explosives without the thermal limitations reported to date with ?GC columns using epoxy based interconnect technology. PMID:24866564

Gaddes, David; Westland, Jessica; Dorman, Frank L; Tadigadapa, Srinivas

2014-07-01

386

CIRCLE PACKING AND DISCRETE ANALYTIC FUNCTION THEORY  

E-print Network

CIRCLE PACKING AND DISCRETE ANALYTIC FUNCTION THEORY KENNETH STEPHENSON Abstract. Circle packings | con#12;gurations of circles with speci#12;ed patterns of tangency | came to prominence with analysts that one can fairly claim that circle packing provides a discrete analytic function theory. There are two

Stephenson, Kenneth

387

CIRCLE PACKING BIBLIOGRAPHY AS OF SEPTEMBER 2005  

E-print Network

CIRCLE PACKING BIBLIOGRAPHY AS OF SEPTEMBER 2005 MAINTAINED BY KENNETH STEPHENSON The term circle packing here refers to con#12;gurations of circles with speci#12;ed pat- terns of tangency. The central with density and coverings using sphere's of given radii.) The software package CirclePack for creating

Stephenson, Kenneth

388

Climate Change Action Pack Climate & Habitats  

E-print Network

Climate Change Action Pack Climate & Habitats B A C K G R O U DN C H E C K ! Habitat, Food, Water the potential to affect plants,animals and humans around the globe. #12;Climate Change Action Pack 158 Habitat out in shapes of hills, waves, leaves, and berries. #12;Climate Change Action Pack 159 PROCEDURE

Gunawardena, Arunika

389

Latching mechanism for deployable/re-stowable columns useful in satellite construction  

NASA Technical Reports Server (NTRS)

A column longeron latch assembly provides the securing mechanism for the deployable, telescoping column of a hoop/column antenna. The column is an open lattice structure with three longerons disposed 120 deg apart as the principle load bearing member. The column is deployed from a pair of eleven nested bays disposed on opposite sides of a center section under the influence of a motor-cable-pulley system. The longeron latch is a four bar linkage mechanism using the over-center principle for automatically locking the longeron sections into position during deployment. The latch is unlocked when the antenna is to be restowed. A spring pack disposed in the end of each longeron serves to absorb stress forces on the deployed column through the cam head piston and abutting latch from an adjacent longeron.

Ahl, E. L., Jr. (inventor)

1986-01-01

390

Predicting Stability of Distiller’s Wet Grains (DWG) with Color Analysis  

Microsoft Academic Search

Distiller’s wet grain (DWG) is one of the coproducts from the fuel ethanol industry. Although many studies have investigated\\u000a the nutritional properties of DWG, little work has investigated the storability and shelf life for these feed products or\\u000a how to measure these quantities. The objectives of this research were to measure the development of microorganisms and their\\u000a respiration over time

K. A. Rosentrater; R. M. Lehman

2010-01-01

391

Thermal analysis for ion-exchange column system  

SciTech Connect

Models have been developed to simulate the thermal characteristics of Crystalline Silico-titanate (CST) ion exchange media fully loaded with radioactive cesium in a column configuration and distributed within a waste storage tank. This work was conducted to support the Small Column Ion Exchange (SCIX) program which is focused on processing dissolved, high-sodium salt waste for the removal of specific radionuclides (including Cs-137, Sr-90, and actinides) within a High Level Waste (HLW) storage tank at the Savannah River Site. A two-dimensional computational modeling approach for the in-column ion-exchange domain was taken to include conservative, bounding estimates for key parameters such that the results would provide the maximum centerline temperatures achievable under the design configurations using a feed composition known to promote high cesium loading on CST. A primary objective of these calculations was to estimate temperature distributions across packed CST beds immersed in waste supernate or filled with dry air under various accident scenarios. Accident scenarios evaluated included loss of salt solution flow through the bed, inadvertent column drainage, and loss of active cooling in the column. The modeling results demonstrate that the baseline design using one central and four outer cooling tubes provides a highly efficient cooling mechanism for reducing the maximum column temperature. (authors)

Lee, S. Y.; King, W. D. [Savannah River National Laboratory, Savannah River Site, Aiken, SC 29808 (United States)

2012-07-01

392

Cell aggregation: Packing soft grains  

NASA Astrophysics Data System (ADS)

Cellular aggregates may be considered as collections of membrane enclosed units with a pressure difference between the internal and external liquid phases. Cells are kept together by membrane adhesion and/or confined space compression. Pattern formation and, in particular, intercellular spacing have important roles in controlling solvent diffusion within such aggregates. A physical approach is used to study generic aspects of cellular packings in a confined space. Average material properties are derived from the free energy. The appearance of penetrating intercellular void channels is found to be critically governed by the cell wall adhesion mechanisms during the formation of dense aggregates. A fully relaxed aggregate efficiently hinders solvent diffusion at high hydrostatic pressures, while a small fraction (˜0.1) of adhesion related packing frustration is sufficient for breaking such a blockage even at high a pressure.

Åström, J. A.; Karttunen, M.

2006-06-01

393

Cell aggregation: packing soft grains.  

PubMed

Cellular aggregates may be considered as collections of membrane enclosed units with a pressure difference between the internal and external liquid phases. Cells are kept together by membrane adhesion and/or confined space compression. Pattern formation and, in particular, intercellular spacing have important roles in controlling solvent diffusion within such aggregates. A physical approach is used to study generic aspects of cellular packings in a confined space. Average material properties are derived from the free energy. The appearance of penetrating intercellular void channels is found to be critically governed by the cell wall adhesion mechanisms during the formation of dense aggregates. A fully relaxed aggregate efficiently hinders solvent diffusion at high hydrostatic pressures, while a small fraction (approximately 0.1) of adhesion related packing frustration is sufficient for breaking such a blockage even at high a pressure. PMID:16906885

Aström, J A; Karttunen, M

2006-06-01

394

27 CFR 19.739 - Authorized transfers to or from distilled spirits plants.  

Code of Federal Regulations, 2012 CFR

...transfers to or from distilled spirits plants. 19.739 Section 19.739 Alcohol...TREASURY LIQUORS DISTILLED SPIRITS PLANTS Distilled Spirits for Fuel Use Transfer of Spirits to and from Distilled Spirits Plants § 19.739 Authorized transfers...

2012-04-01

395

27 CFR 19.739 - Authorized transfers to or from distilled spirits plants.  

Code of Federal Regulations, 2014 CFR

...transfers to or from distilled spirits plants. 19.739 Section 19.739 Alcohol...TREASURY ALCOHOL DISTILLED SPIRITS PLANTS Distilled Spirits for Fuel Use Transfer of Spirits to and from Distilled Spirits Plants § 19.739 Authorized transfers...

2014-04-01

396

27 CFR 19.739 - Authorized transfers to or from distilled spirits plants.  

Code of Federal Regulations, 2013 CFR

...transfers to or from distilled spirits plants. 19.739 Section 19.739 Alcohol...TREASURY ALCOHOL DISTILLED SPIRITS PLANTS Distilled Spirits for Fuel Use Transfer of Spirits to and from Distilled Spirits Plants § 19.739 Authorized transfers...

2013-04-01

397

27 CFR 19.739 - Authorized transfers to or from distilled spirits plants.  

Code of Federal Regulations, 2011 CFR

...transfers to or from distilled spirits plants. 19.739 Section 19.739 Alcohol...TREASURY LIQUORS DISTILLED SPIRITS PLANTS Distilled Spirits for Fuel Use Transfer of Spirits to and from Distilled Spirits Plants § 19.739 Authorized transfers...

2011-04-01

398

Rejection and fate of trace organic compounds (TrOCs) during membrane distillation  

E-print Network

. Introduction Membrane distillation (MD) is a low temperature distillation process that involves the transportRejection and fate of trace organic compounds (TrOCs) during membrane distillation Kaushalya COCs) Direct contact membrane distillation (DCMD) Volatility Fate and transport Hydrophobicity

399

27 CFR 19.162 - Operations bond for distilled spirits plant and adjacent bonded wine cellar.  

Code of Federal Regulations, 2013 CFR

...for a distilled spirits plant and adjacent bonded wine...Such distilled spirits plant is qualified under subpart D of this part for the production of distilled spirits; and...cellar and distilled spirits plant are operated by the...

2013-04-01

400

27 CFR 19.241 - Operations bond-distilled spirits plant and adjacent bonded wine cellar.  

Code of Federal Regulations, 2010 CFR

...being adjacent to a distilled spirits plant if— (1) Such distilled spirits plant is qualified under subpart G for the production of distilled spirits; and ...wine cellar and distilled spirits plant are operated by the same...

2010-04-01

401

27 CFR 19.162 - Operations bond for distilled spirits plant and adjacent bonded wine cellar.  

Code of Federal Regulations, 2014 CFR

...for a distilled spirits plant and adjacent bonded wine...Such distilled spirits plant is qualified under subpart D of this part for the production of distilled spirits; and...cellar and distilled spirits plant are operated by the...

2014-04-01

402

27 CFR 19.162 - Operations bond for distilled spirits plant and adjacent bonded wine cellar.  

Code of Federal Regulations, 2011 CFR

...for a distilled spirits plant and adjacent bonded wine...Such distilled spirits plant is qualified under subpart D of this part for the production of distilled spirits; and...cellar and distilled spirits plant are operated by the...

2011-04-01

403

27 CFR 19.162 - Operations bond for distilled spirits plant and adjacent bonded wine cellar.  

Code of Federal Regulations, 2012 CFR

...for a distilled spirits plant and adjacent bonded wine...Such distilled spirits plant is qualified under subpart D of this part for the production of distilled spirits; and...cellar and distilled spirits plant are operated by the...

2012-04-01

404

27 CFR 1.82 - Acquiring or receiving distilled spirits in bulk for redistillation, processing, rectification...  

Code of Federal Regulations, 2010 CFR

...false Acquiring or receiving distilled spirits in bulk for redistillation, processing...ADMINISTRATION ACT, NONINDUSTRIAL USE OF DISTILLED SPIRITS AND WINE, BULK SALES AND BOTTLING OF DISTILLED SPIRITS Bulk Sales and Bottling of Distilled...

2010-04-01

405

27 CFR 1.84 - Acquisition of distilled spirits in bulk by Government agencies.  

Code of Federal Regulations, 2010 CFR

...2010-04-01 false Acquisition of distilled spirits in bulk by Government agencies. 1.84...ADMINISTRATION ACT, NONINDUSTRIAL USE OF DISTILLED SPIRITS AND WINE, BULK SALES AND BOTTLING OF DISTILLED SPIRITS Bulk Sales and Bottling of Distilled...

2010-04-01

406

27 CFR 17.163 - Evidence of taxpayment of distilled spirits.  

Code of Federal Regulations, 2010 CFR

... Evidence of taxpayment of distilled spirits. 17.163 Section 17.163 Alcohol...LIQUORS DRAWBACK ON TAXPAID DISTILLED SPIRITS USED IN MANUFACTURING NONBEVERAGE PRODUCTS... Evidence of taxpayment of distilled spirits. (a) Shipments from distilled...

2010-04-01

407

27 CFR 1.83 - Acquiring or receiving distilled spirits in bulk for addition to wine.  

Code of Federal Regulations, 2010 CFR

...false Acquiring or receiving distilled spirits in bulk for addition to wine. 1.83...ADMINISTRATION ACT, NONINDUSTRIAL USE OF DISTILLED SPIRITS AND WINE, BULK SALES AND BOTTLING OF DISTILLED SPIRITS Bulk Sales and Bottling of Distilled...

2010-04-01

408

DIRECT COMPUTATIONS TO DESCRIBE BATCH DISTILLATION WITH RECTIFICATION  

Microsoft Academic Search

An analog of the Rayleigh Equation has been applied for many years to describe batch distillation with rectification for binary mixtures. A solution is obtained by iterative graphical computations followed by numerical integration. When the batch distillation algorithm is stated in terms of distillate composition a computational non-iterative soluton may be obtained. For a binary separation this expression may be

RAYMOND C. WAGGONER

1990-01-01

409

Key Distillation and the Secret-Bit Fraction  

Microsoft Academic Search

We consider distillation of secret bits from partially secret noisy correlations , shared between two honest par- ties and an eavesdropper. The most studied distillation scenario consists of joint operations on a large number of copies of the distribution , assisted with public communication. Here we consider distillation with only one copy of the distribution, and instead of rates, the

Nick S. Jones; Lluis Masanes

2006-01-01

410

Distillation and solvent extraction process for rerefining used lubricating oil  

Microsoft Academic Search

Used oil is rerefined by distillation and extraction with tetrahydrofurfuryl alcohol. In accordance with the process, used oil is rerefined by distillation to remove a volatile forecut followed by further distillation with recirculation provisions to obtain the desired fractions of lubricating oil products while reducing the vaporization temperature of the oil. The recycle effect tends to reduce coking and cracking

H. J. Beard; L. C. Fletcher; R. Oblasny

1982-01-01

411

Application of vacuum membrane distillation for ammonia removal  

Microsoft Academic Search

This study aims to investigate the applicability of membrane distillation for ammonia removal from its aqueous solutions. Among the different recognized membrane distillation configurations, vacuum membrane distillation is applied in the present work for ammonia removal. The effects of different operating parameters on ammonia removal from aqueous solutions of different concentrations have been investigated. Experimental results showed that high feed

M. S. EL-Bourawi; M. Khayet; R. Ma; Z. Ding; Z. Li; X. Zhang

2007-01-01

412

Planet packing in circumbinary systems  

NASA Astrophysics Data System (ADS)

The recent discovery of planets orbiting main-sequence binaries will provide crucial constraints for theories of binary and planet formation. The formation pathway for these planets is complicated by uncertainties in the formation mechanism of the host stars. In this paper, we compare the dynamical states of single- and binary-star planetary systems. Specifically, we pose two questions: (1) What does it mean for a circumbinary system to be dynamically packed? (2) How many systems are required to differentiate between a population of packed or sparse planets? We determine when circumbinary systems become dynamically unstable as a function of the separation between the host-stars and the inner planet, and the first and second planets. We show that these represent unique stability constraints compared to single-star systems. We find that although the existing Kepler data is insufficient to distinguish between a population of packed or sparse circumbinary systems, a more thorough study of circumbinary Transit Timing Variations (TTVs) combined with an order of magnitude increase in the number of systems may prove conclusive. Future space missions such as TESS provide the best opportunity for increasing the sample size.

Kratter, Kaitlin M.; Shannon, Andrew

2014-02-01

413

TOTAL REFLUX OPERATION OF MULTIVESSEL BATCH DISTILLATION  

E-print Network

between total reflux operation and dumping the product (i.e., the condenser holdup is introduced in the condenser drum and in the reboiler. Another alternative is to ''invert'' the column by charging the feed column by calculating in advance the final holdup in each vessel and then using a level control system

Skogestad, Sigurd

414

Adhesive Loose Packings of Small Particles  

E-print Network

We explore adhesive loose packings of dry small spherical particles of micrometer size using 3D discrete-element simulations with adhesive contact mechanics. A dimensionless adhesion parameter ($Ad$) successfully combines the effects of particle velocities, sizes and the work of adhesion, identifying a universal regime of adhesive packings for $Ad>1$. The structural properties of the packings in this regime are well described by an ensemble approach based on a coarse-grained volume function that includes correlations between bulk and contact spheres. Our theoretical and numerical results predict: (i) An equation of state for adhesive loose packings that appears as a continuation from the frictionless random close packing (RCP) point in the jamming phase diagram; (ii) The existence of a maximal loose packing point at the coordination number $Z=2$ and packing fraction $\\phi=1/2^{3}$. Our results highlight that adhesion leads to a universal packing regime at packing fractions much smaller than the random loose packing, which can be described within a statistical mechanical framework. We present a general phase diagram of jammed matter comprising frictionless, frictional, adhesive as well as non-spherical particles, providing a classification of packings in terms of their continuation from the spherical frictionless RCP.

Wenwei Liu; Shuiqing Li; Adrian Baule; Hernán A. Makse

2014-10-08

415

Identification of a Pilot Scale Distillation Column: A Kernel Based Approach  

E-print Network

economic and environmental issues be- come more and more important, efficient knowledge of the behavior of possible model structures and techniques exists , e.g., neural networks, wavelets, fuzzy models and Least problem of finding the vector w and b R for regression can be formulated as follows (Suykens et al., 2002

416

Calculational procedure for multicomponent distillation columns with side-stream-strippers  

E-print Network

are initiated at ths bottom of the stripper. Any vapox' rate oalculated by an enthalpy balance is parsd. tted to differ by no more than a specified amount from the one used to saks the given trial calculation. If the oalculated value differs avre than...

Dickey, Billy Ray

2012-06-07

417

Kinetics of pack aluminization of nickel  

NASA Technical Reports Server (NTRS)

The kinetics of pack aluminization of unalloyed nickel in packs of varying aluminum activity with various halide activators were studied. Surface compositions of the coatings as functions of time, temperature, and pack composition were obtained in order to establish the boundary conditions for diffusion in the system. The structure of the packs was also examined in order to clarify the mechanism of aluminum transport. The results indicate that the kinetics of pack aluminization are controlled jointly by gas diffusion in the pack and solid diffusion in the coating. Levine and Caves' model for gas diffusion was combined with calculations of rates of diffusion in the solid to formulate a more complete theory for the kinetics of pack aluminization.

Seigle, L. L.; Gupta, B. K.; Shankar, R.; Sarkhel, A. K.

1978-01-01

418

Secret key distillation from shielded two-qubit states  

SciTech Connect

The quantum states corresponding to a secret key are characterized using the so-called private states, where the key part consisting of a secret key is shielded by the additional systems. Based on the construction, it was shown that a secret key can be distilled from bound entangled states. In this work, I consider the shielded two-qubit states in a key-distillation scenario and derive the conditions under which a secret key can be distilled using the recurrence protocol or the two-way classical distillation, advantage distillation together with one-way postprocessing. From the security conditions, it is shown that a secret key can be distilled from bound entangled states in a much wider range. In addition, I consider the case that in which white noise is added to quantum states and show that the classical distillation protocol still works despite a certain amount of noise although the recurrence protocol does not.

Bae, Joonwoo [School of Computational Sciences, Korea Institute for Advanced Study, Seoul 130-722 (Korea, Republic of)

2010-05-15

419

Secret key distillation from shielded two-qubit states  

E-print Network

The quantum states corresponding to a secret key are characterized using the so-called private states, where the key part consisting of a secret key is shielded by the additional systems. Based on the construction, it was shown that a secret key can be distilled from bound entangled states. In this work, I consider the shielded two-qubit states in a key-distillation scenario and derive the conditions under which a secret key can be distilled using the recurrence protocol or the two-way classical distillation, advantage distillation together with one-way postprocessing. From the security conditions, it is shown that a secret key can be distilled from bound entangled states in a much wider range. In addition, I consider the case that in which white noise is added to quantum states and show that the classical distillation protocol still works despite a certain amount of noise although the recurrence protocol does not.

Joonwoo Bae

2008-03-03

420

Solar desalination by freezing and distillation  

NASA Astrophysics Data System (ADS)

It is noted that among seawater desalination processes the absorption-freeze vapor compression processes based on the thermal heat pump, although untested commercially and still in the development stage, appears technically and economically an attractive application of low-grade (exergy) solar heat. The distillation processes proposed here may be conveniently powered by low-grade solar heat (from flat plate solar collectors). It is expected that the scaling problem will be insignificant in comparison with that encountered in the conventional multistage flash process. The novel feature here is the use of enlarged capacity for heat exchange between distillate and brine via latent heat of solid-liquid phase change of a suitable hydrophobic intermediate heat transfer material.

Kvajic, G.

421

Multi-temperature gas chromatography using isothermal columns in series. Technical report  

SciTech Connect

A computer-controlled three-oven gas chromatograph having a multi-position stream-switching valve has been used first to divide a wide-boiling mixture of n-alkanes into three cuts and then to fractionate each cut using a packed column at a different temperature. After initial injection of the sample into the highest temperature column, the low boilers were switched to a low temperature oven. Then, the mid-boilers were switched to a column at an intermediate temperature. For routine repetitive analyses, the multi-oven approach offers an attractive alternative.

Spencer, W.A.; Rogers, L.B.

1980-08-11

422

Desalination Using Vapor-Compression Distillation  

E-print Network

to thank my committee members, Dr. Barrufet and Dr. El- Halwagi, for their guidance throughout the completion of this research. I am truly grateful to Dr. Jorge Lara, the faculty, and the staff of the Chemical Engineering Department of Texas A... is commonly used for small- and medium-scale desalination units. There are two methods to compress the vapor: mechanical compressors and steam jets. Lara [6] states that mechanical vapor compression is very efficient. Unlike other distillation systems...

Lubis, Mirna R.

2010-07-14

423

Attractor mechanism as a distillation procedure  

SciTech Connect

In a recent paper it was shown that for double extremal static spherical symmetric BPS black hole solutions in the STU model the well-known process of moduli stabilization at the horizon can be recast in a form of a distillation procedure of a three-qubit entangled state of a Greenberger-Horne-Zeilinger type. By studying the full flow in moduli space in this paper we investigate this distillation procedure in more detail. We introduce a three-qubit state with amplitudes depending on the conserved charges, the warp factor, and the moduli. We show that for the recently discovered non-BPS solutions it is possible to see how the distillation procedure unfolds itself as we approach the horizon. For the non-BPS seed solutions at the asymptotically Minkowski region we are starting with a three-qubit state having seven nonequal nonvanishing amplitudes and finally at the horizon we get a Greenberger-Horne-Zeilinger state with merely four nonvanishing ones with equal magnitudes. The magnitude of the surviving nonvanishing amplitudes is proportional to the macroscopic black hole entropy. A systematic study of such attractor states shows that their properties reflect the structure of the fake superpotential. We also demonstrate that when starting with the very special values for the moduli corresponding to flat directions the uniform structure at the horizon deteriorates due to errors generalizing the usual bit flips acting on the qubits of the attractor states.

Levay, Peter; Szalay, Szilard [Department of Theoretical Physics, Institute of Physics, Budapest University of Technology and Economics, H-1521 Budapest (Hungary)

2010-07-15

424

The distillation and volatility of ionic liquids  

NASA Astrophysics Data System (ADS)

It is widely believed that a defining characteristic of ionic liquids (or low-temperature molten salts) is that they exert no measurable vapour pressure, and hence cannot be distilled. Here we demonstrate that this is unfounded, and that many ionic liquids can be distilled at low pressure without decomposition. Ionic liquids represent matter solely composed of ions, and so are perceived as non-volatile substances. During the last decade, interest in the field of ionic liquids has burgeoned, producing a wealth of intellectual and technological challenges and opportunities for the production of new chemical and extractive processes, fuel cells and batteries, and new composite materials. Much of this potential is underpinned by their presumed involatility. This characteristic, however, can severely restrict the attainability of high purity levels for ionic liquids (when they contain poorly volatile components) in recycling schemes, as well as excluding their use in gas-phase processes. We anticipate that our demonstration that some selected families of commonly used aprotic ionic liquids can be distilled at 200-300°C and low pressure, with concomitant recovery of significant amounts of pure substance, will permit these currently excluded applications to be realized.

Earle, Martyn J.; Esperança, José M. S. S.; Gilea, Manuela A.; Canongia Lopes, José N.; Rebelo, Luís P. N.; Magee, Joseph W.; Seddon, Kenneth R.; Widegren, Jason A.

2006-02-01

425

Distillation Designs for the Lunar Surface  

NASA Technical Reports Server (NTRS)

Gravity-based distillation methods may be applied to the purification of wastewater on the lunar base. These solutions to water processing are robust physical separation techniques, which may be more advantageous than many other techniques for their simplicity in design and operation. The two techniques can be used in conjunction with each other to obtain high purity water. The components and feed compositions for modeling waste water streams are presented in conjunction with the Aspen property system for traditional stage distillation. While the individual components for each of the waste streams will vary naturally within certain bounds, an analog model for waste water processing is suggested based on typical concentration ranges for these components. Target purity levels for recycled water are determined for each individual component based on NASA s required maximum contaminant levels for potable water Optimum parameters such as reflux ratio, feed stage location, and processing rates are determined with respect to the power consumption of the process. Multistage distillation is evaluated for components in wastewater to determine the minimum number of stages necessary for each of 65 components in humidity condensate and urine wastewater mixed streams.

Boul, Peter J.; Lange,Kevin E.; Conger, Bruce; Anderson, Molly

2010-01-01

426

Experiments on Random Packings of Ellipsoids  

NASA Astrophysics Data System (ADS)

Recent simulations indicate that ellipsoids can pack randomly more densely than spheres and, remarkably, for axes ratios near 1.25?1?0.8 can approach the densest crystal packing (fcc) of spheres, with a packing fraction of 74%. We demonstrate that such dense packings are realizable. We introduce a novel way of determining packing density for a finite sample that minimizes surface effects. We have fabricated ellipsoids and show that, in a sphere, the radial packing fraction ?(r) can be obtained from V(h), the volume of added fluid to fill the sphere to height h. We also obtain ?(r) from a magnetic resonance imaging scan. The measurements of the overall density ?avr, ?(r) and the core density ?0=0.74±0.005 agree with simulations.

Man, Weining; Donev, Aleksandar; Stillinger, Frank H.; Sullivan, Matthew T.; Russel, William B.; Heeger, David; Inati, Souheil; Torquato, Salvatore; Chaikin, P. M.

2005-05-01

427

Experimental investigations on the performance of a packed bed dehumidifier for various climatic conditions  

SciTech Connect

To simulate space cooling or drying systems for various geographical regions (low, moderate, and high humidity regions) a liquid desiccant system consisting of a humidifier and dehumidifier has been designed and constructed. This system consists of two coupled humidifying and dehumidifying packed columns filled with plastic Intalox Snowflake packing material. Experimental measurements of the dehumidifier performance utilizing a new cost effective liquid desiccant mixture (CELD), total desiccant salt content 40%wt to 45%wt (salt comprised of equal portions by weight of lithium chloride and calcium chloride), have been carried out. The effect of different independent variables such as packing height, air inlet temperature and humidity ratio, and liquid desiccant inlet temperature, flow rate and concentration on the performance of the dehumidifier has been investigated. Experimental results demonstrate that the CELD is a promising desiccant for cooling and drying operations.

Ertas, A.; Gandhidasan, P.; Kiris, I.; Anderson, E.E. [Texas Tech Univ., Lubbock, TX (United States). Dept. of Mechanical Engineering; Dolan, M. [Norton Co., Akron, OH (United States)

1997-03-01

428

Apparatus for distilling shale oil from oil shale  

SciTech Connect

An apparatus for distilling shale oil from oil shale comprises: a vertical type distilling furnace which is divided by two vertical partitions each provided with a plurality of vent apertures into an oil shale treating chamber and two gas chambers, said oil shale treating chamber being located between said two gas chambers in said vertical type distilling furnace, said vertical type distilling furnace being further divided by at least one horizontal partition into an oil shale distilling chamber in the lower part thereof and at least one oil shale preheating chamber in the upper part thereof, said oil shale distilling chamber and said oil shale preheating chamber communication with each other through a gap provided at an end of said horizontal partition, an oil shale supplied continuously from an oil shale supply port provided in said oil shale treating chamber at the top thereof into said oil shale treating chamber continuously moving from the oil shale preheating chamber to the oil shale distilling chamber, a high-temperature gas blown into an oil shale distilling chamber passing horizontally through said oil shale in said oil shale treating chamber, thereby said oil shale is preheated in said oil shale preheating chamber, and a gaseous shale oil is distilled from said preheated oil shale in said oil shale distilling chamber; and a separator for separating by liquefaction a gaseous shale oil from a gas containing the gaseous shale oil discharged from the oil shale preheating chamber.

Shishido, T.; Sato, Y.

1984-02-14

429

Close-packing of growing discs  

SciTech Connect

Spiral lattices are derived by allowing growing discs to aggregate under a close-packing rule. Both Fibonacci and Lucas numbers of visible spirals arise naturally, dependent only on the choice of growth centre. Both the rate of convergence towards an ideal spiral, and chirality, are determined by the initial placement of the first few discs (initial conditions). Thus the appearance of spiral packings is no more or less mysterious than the appearance of hexagonal packed arrays of equal discs.

Bursill, L.A.; Xudong, F. (Melbourne Univ., Parkville (Australia). School of Physics)

1988-12-01

430

Close-Packing of Growing Discs  

NASA Astrophysics Data System (ADS)

Spiral lattices are derived by allowing growing discs to aggregate under a close-packing rule. Both Fibonacci and Lucas numbers of visible spirals arise naturally, dependent only on the choice of growth centre. Both the rate of convergence towards an ideal spiral, and chirality, are determined by the initial placement of the first few discs (initial conditions). Thus the appearance of spiral packings is no more or less mysterious than the appearance of hexagonal packed arrays of equal discs.

Bursill, L. A.; Xudong, Fan

431

Theory of cylindrical dense packings of disks.  

PubMed

We have previously explored cylindrical packings of disks and their relation to sphere packings. Here we extend the analytical treatment of disk packings, analyzing the rules for phyllotactic indices of related structures and the variation of the density for line-slip structures, close to the symmetric ones. We show that rhombic structures, which are of a lower density, are always unstable, i.e., can be increased in density by small perturbations. PMID:24827251

Mughal, A; Weaire, D

2014-04-01

432

Leaching potential of phenylurea herbicides in a calcareous soil: comparison of column elution and batch studies.  

PubMed

The transfer of eleven phenylurea herbicides through soil columns was investigated in laboratory conditions in order to determine leaching properties in a calcareous soil. Elution curves with distilled water were plotted after herbicide application on the soil column. Phenylurea retention by the soil indicating interactions with soil can be classified as follows: fenuron < fluometron ? isoproturon = monuron < metoxuron < monolinuron < metobromuron < chlorotoluron < linuron = diuron < chlorbromuron. The number and nature of halogen atoms on the phenyl ring had an important influence on leaching. Retention was higher for molecules with higher number of halogen, and it was also higher for bromine than chlorine. Column elution experiments were compared to batch experiments from which the distribution coefficients K d were determined. According to Kendall correlation coefficients, parameter m/m 0 max from column experiments was relatively well linked to K d. In case of phenylurea, a linear relationship between K d and m/m 0 max was established. PMID:23097070

Langeron, Julie; Sayen, Stéphanie; Couderchet, Michel; Guillon, Emmanuel

2014-04-01

433

Application of Nanofiber-packed SPE for Determination of Urinary 1-Hydroxypyrene Level Using HPLC  

PubMed Central

It is always desirable to achieve maximum sample clean-up, extraction, and pre-concentration with the minimum possible organic solvent. The miniaturization of sample preparation devices was successfully demonstrated by packing 10 mg of 11 electrospun polymer nanofibers into pipette tip micro column and mini disc cartridges for efficient pre-concentration of 1-hydroxypyrene in urine samples. 1-hydroxypyrene is an extensively studied biomarker of the largest class of chemical carcinogens. Excretory 1-hydroxypyrene was monitored with HPLC/fluorescence detector. Important parameters influencing the percentage recovery such as fiber diameter, fiber packing amount, eluent, fiber packing format, eluent volume, surface area, porosity, and breakthrough parameters were thoroughly studied and optimized. Under optimized condition, there was a near perfect linearity of response in the range of 1–1000 ?g/L with a coefficient of determination (r2) between 0.9992 and 0.9999 and precision (% RSD) ?7.64% (n = 6) for all the analysis (10, 25, and 50 ?g/L). The Limit of detection (LOD) was between 0.022 and 0.15 ?g/L. When compared to the batch studies, both disc packed nanofiber sorbents and pipette tip packed sorbents exhibited evident dominance based on their efficiencies. The experimental results showed comparable absolute recoveries for the mini disc packed fibers (84% for Nylon 6) and micro columns (80% for Nylon 6), although the disc displayed slightly higher recoveries possibly due to the exposure of the analyte to a larger reacting surface. The results also showed highly comparative extraction efficiencies between the nanofibers and conventional C-18 SPE sorbent. Nevertheless, miniaturized SPE devices simplified sample preparation, reducing back pressure, time of the analysis with acceptable reliability, selectivity, detection levels, and environmental friendliness, hence promoting green chemistry. PMID:24812483

Ifegwu, Okechukwu Clinton; Anyakora, Chimezie; Chigome, Samuel; Torto, Nelson

2014-01-01

434

Virus movement in soil columns flooded with secondary sewage effluent.  

PubMed

Secondary sewage effluent containing about 3 X 10(4) plaque-forming units of polio virus type 1 (LSc) per ml was passed through columns 250 cm in length packed with calcareous sand from an area in the Salt River bed used for ground-water recharge of secondary sewage effluent. Viruses were not detected in 1-ml samples extracted from the columns below the 160-cm level. However, viruses were detected in 5 of 43 100-ml samples of the column drainage water. Most of the viruses were adsorbed in the top 5 cm of soil. Virus removal was not affected by the infiltration rate, which varied between 15 and 55 cm/day. Flooding a column continuosly for 27 days with the sewage water virus mixture did not saturate the top few centimeters of soil with viruses and did not seem to affect virus movement. Flooding with deionized water caused virus desorption from the soil and increased their movement through the columns. Adding CaCl2 to the deionized water prevented most of the virus desorption. Adding a pulse of deionized water followed by sewage water started a virus front moving through the columns, but the viruses were readsorbed and none was detected in outflow samples. Drying the soil for 1 day between applying the virus and flooding with deionized water greatly reduced desorption, and drying for 5 days prevented desorption. Large reductions (99.99% or more) of virus would be expected after passage of secondary sewage effluent through 250 cm of the calcareous sand similar to that used in our laboratory columns unless heavy rains fell within 1 day after the application of sewage stopped. Such virus movement could be minimized by the proper management of flooding and drying cycles. PMID:185960

Lance, J C; Gerba, C P; Melnick, J L

1976-10-01

435

Virus movement in soil columns flooded with secondary sewage effluent.  

PubMed Central

Secondary sewage effluent containing about 3 X 10(4) plaque-forming units of polio virus type 1 (LSc) per ml was passed through columns 250 cm in length packed with calcareous sand from an area in the Salt River bed used for ground-water recharge of secondary sewage effluent. Viruses were not detected in 1-ml samples extracted from the columns below the 160-cm level. However, viruses were detected in 5 of 43 100-ml samples of the column drainage water. Most of the viruses were adsorbed in the top 5 cm of soil. Virus removal was not affected by the infiltration rate, which varied between 15 and 55 cm/day. Flooding a column continuosly for 27 days with the sewage water virus mixture did not saturate the top few centimeters of soil with viruses and did not seem to affect virus movement. Flooding with deionized water caused virus desorption from the soil and increased their movement through the columns. Adding CaCl2 to the deionized water prevented most of the virus desorption. Adding a pulse of deionized water followed by sewage water started a virus front moving through the columns, but the viruses were readsorbed and none was detected in outflow samples. Drying the soil for 1 day between applying the virus and flooding with deionized water greatly reduced desorption, and drying for 5 days prevented desorption. Large reductions (99.99% or more) of virus would be expected after passage of secondary sewage effluent through 250 cm of the calcareous sand similar to that used in our laboratory columns unless heavy rains fell within 1 day after the application of sewage stopped. Such virus movement could be minimized by the proper management of flooding and drying cycles. PMID:185960

Lance, J C; Gerba, C P; Melnick, J L

1976-01-01

436

Movement of Endotoxin Through Soil Columns  

PubMed Central

Land treatment of wastewater is an attractive alternative to conventional sewage treatment systems and is gaining widespread acceptance. Although land application systems prevent surface water pollution and augment the available water supplies, the potential dangers to human health should be evaluated. Since sewage may contain high amounts of bacterial endotoxin, the removal of endotoxin from sewage by percolation through soil was investigated. It was found that 90 to 99% of the endotoxin was removed after travel of sewage through 100 to 250 cm of loamy sand soil. When distilled water was allowed to infiltrate into the soil to simulate rainfall, the endotoxin was mobilized and moved in a concentrated band through the soil column. On testing samples from actual land treatment sites, as much as 480 ng of endotoxin per milliliter was found in some groundwater samples. The presence of endotoxin in potable water is known to be a potential problem under some circumstances, but the importance of endotoxin in water supplies has not been fully assessed. Therefore, the design, operation, and management of land application systems should take into account the fate of endotoxin in groundwater beneath the sites. PMID:7387154

Goyal, Sagar M.; Gerba, Charles P.; Lance, J. Clarence

1980-01-01

437

Surface code implementation of block code state distillation  

PubMed Central

State distillation is the process of taking a number of imperfect copies of a particular quantum state and producing fewer better copies. Until recently, the lowest overhead method of distilling states produced a single improved |A? state given 15 input copies. New block code state distillation methods can produce k improved |A? states given 3k + 8 input copies, potentially significantly reducing the overhead associated with state distillation. We construct an explicit surface code implementation of block code state distillation and quantitatively compare the overhead of this approach to the old. We find that, using the best available techniques, for parameters of practical interest, block code state distillation does not always lead to lower overhead, and, when it does, the overhead reduction is typically less than a factor of three. PMID:23736868

Fowler, Austin G.; Devitt, Simon J.; Jones, Cody

2013-01-01

438

ZIRCONIUM CORROSION IN DISTILLED WATER AT 85  

Microsoft Academic Search

Zr corrosion in distilled water (pH = 6.5, SOâ = 0.6 mg\\/l) at 85 ; deg C in contact with 1 x 18H9T steel (0.l2% C, 0.50% Si, l.30% Mn, 18.13% Cr, ; 9.8% Ni, and 0.55% Ti) and with aluminum AlM (0.22 Fe, 0.06 Si, and <0.01 Cu) at ; a surface ratio of 1: 1 was investigated. The

V. V. Gerasimov; A. I. Gromova; E. T. Shapovalov

1961-01-01

439

Distillation and the Role of Weak Forces  

NSDL National Science Digital Library

In this activity, by the Concord Consortium's Molecular Literacy project, students will examine how distillation works and the roles of all components involved in the process. The site is filled with thorough diagrams accompanied by solid textual explanations. Aside from diagrams and text, students will engage in simple quizzes testing the concepts they have just learned. The activity itself is a java-based interactive resource built upon the free, open source Molecular Workbench software. In addition, visitors will find an overview of the activity, assessments, and concepts and their correlation to AAAS and NSES standards.

2008-10-17

440

Drum drying performance of condensed distillers solubles and comparison to performance of modified condensed distillers solubles  

Technology Transfer Automated Retrieval System (TEKTRAN)

Condensed distillers solubles (CDS) is a viscous, syrupy co-product of ethanol production from corn; CDS exhibits strong recalcitrance to drying due to its chemical composition, which includes a substantial amount of glycerol. The objectives of this study were to determine the drum drying performan...

441

Vapor compression distiller and membrane technology for water revitalization  

NASA Technical Reports Server (NTRS)

Water revitalization for a space station can consist of membrane filtration processes and a distillation process. Water recycling equipment using membrane filtration processes was manufactured for ground testing. It was assembled using commercially available components. Two systems for the distillation are studied: one is absorption type thermopervaporation cell and the other is a vapor compression distiller. Absorption type thermopervaporation, able to easily produce condensed water under zero gravity, was investigated experimentally and through simulated calculation. The vapor compression distiller was studied experimentally and it offers significant energy savings for evaporation of water.

Ashida, A.; Mitani, K.; Ebara, K.; Kurokawa, H.; Sawada, I.; Kashiwagi, H.; Tsuji, T.; Hayashi, S.; Otsubo, K.; Nitta, K.

1987-01-01

442

Multiple Destination Bin Packing Bram Verweij  

E-print Network

about on-line and off-line algorithms to solve the two and three dimensional bin packing problem be calculated using dynamic programming in exponential time relative to the size of the input, or by applying applications of the bin packing problem involve two and three dimensional problems, such as loading pallets

Utrecht, Universiteit

443

Circle Packing Explorations Francesco De Comite  

E-print Network

Circle Packing Explorations Francesco De Comit´e Laboratoire d'Informatique Fondamentale de Lille University of Sciences and Technology of Lille France Francesco.De-Comite@univ-lille1.fr Abstract Circle packing can be seen as the art of placing tangent circles on the plane, leaving as little unoccupied space

Paris-Sud XI, Université de

444

CIRCLE PACKING BIBLIOGRAPHY AS OF SEPTEMBER 2005  

E-print Network

CIRCLE PACKING BIBLIOGRAPHY AS OF SEPTEMBER 2005 MAINTAINED BY KENNETH STEPHENSON The term circle packing here refers to configurations of circles with specified pat- terns of tangency, intersection", which is concerned with density and coverings using spheres of given radii.) The software package Circle

Stephenson, Kenneth

445

Is Incest Common In Gray Wolf Packs?  

NSDL National Science Digital Library

In early 2000 the Northern Prairie Wildlife Research Center posted this resource on wolves at their Website. "Is Incest Common In Gray Wolf Packs?" suggests that incest is rare in wolf packs. The resource may be downloaded as a .zip file.

Adams, Layne G.; Burch, John W.; Geffen, Eli ..; Mech, L. D.; Meier, Thomas J.; Smith, Deborah.

446

Compact attic mounted solar heating pack assembly  

Microsoft Academic Search

A compact attic solar heating pack assembly for mounting within a building attic having south and north facing roof sections overlying a horizontal building attic floor forming the ceiling and defining an enclosed attic space above the occupied room space below the ceiling is described. The pack assembly comprises: a closed sheet metal plenum, means for fixedly mounting the plenum

1988-01-01

447

Kid's PACK: Population Awareness Campaign Kit.  

ERIC Educational Resources Information Center

This fun and educational kit is designed specifically for elementary students. The "Kid's PACK" (Population Awareness Campaign Kit) entertains and informs children on the environment and human population growth through stories, games, and concrete ideas for making a difference. In three booklets, the "Kid's PACK" offers elementary students…

Zero Population Growth, Inc., Washington, DC.

448

Softening of Granular Packings with Dynamic Forcing  

E-print Network

We perform numerical simulations of a two-dimensional bidisperse granular packing subjected to both a static confining pressure and a sinusoidal dynamic forcing applied by a wall on one edge of the packing. We measure the response experienced by a wall on the opposite edge of the packing and obtain the resonant frequency of the packing as the static or dynamic pressures are varied. Under increasing static pressure, the resonant frequency increases, indicating a velocity increase of elastic waves propagating through the packing. In contrast, when the dynamic amplitude is increased for fixed static pressure, the resonant frequency decreases, indicating a decrease in the wave velocity. This occurs both for compressional and for shear dynamic forcing, and is in agreement with experimental results. We find that the average contact number $Z_c$ at the resonant frequency decreases with increasing dynamic amplitude, indicating that the elastic softening of the packing is associated with a reduced number of grain-grain contacts through which the elastic waves can travel. We image the excitations created in the packing and show that there are localized disturbances or soft spots that become more prevalent with increasing dynamic amplitude. Our results are in agreement with experiments on glass bead packings and earth materials such as sandstone and granite, and may be relevant to the decrease in elastic wave velocities that has been observed to occur near fault zones after strong earthquakes, in surficial sediments during strong ground motion, and in structures during earthquake excitation.

C. J. Olson Reichhardt; L. M. Lopatina; X. Jia; P. A. Johnson

2014-06-17

449

Enhanced EP halftones with hexagonal dot packing  

E-print Network

Enhanced EP halftones with hexagonal dot packing Tomasz J. Cholewo, Steve Weed, Brian Cooper advantages for electropho- tographic (EP) printing over conventional dot placement on a square grid [1] reported that hexagonal dot packing could have some unique benefits for EP printing. These were

Cholewo, Tomasz

450

7 CFR 51.1527 - Standard pack.  

Code of Federal Regulations, 2012 CFR

...container. (4) “Tightly packed” means the plums or prunes are the proper size for the mold or cell compartments in which they are packed, and the molds or cells are filled in such a way that movement is not allowed. (b) Marking....

2012-01-01

451

7 CFR 51.1527 - Standard pack.  

Code of Federal Regulations, 2011 CFR

...container. (4) “Tightly packed” means the plums or prunes are the proper size for the mold or cell compartments in which they are packed, and the molds or cells are filled in such a way that movement is not allowed. (b) Marking....

2011-01-01

452

7 CFR 51.1527 - Standard pack.  

Code of Federal Regulations, 2010 CFR

...container. (4) “Tightly packed” means the plums or prunes are the proper size for the mold or cell compartments in which they are packed, and the molds or cells are filled in such a way that movement is not allowed. (b) Marking....

2010-01-01

453

7 CFR 51.1527 - Standard pack.  

Code of Federal Regulations, 2014 CFR

...container. (4) “Tightly packed” means the plums or prunes are the proper size for the mold or cell compartments in which they are packed, and the molds or cells are filled in such a way that movement is not allowed. (b) Marking....

2014-01-01

454

7 CFR 51.1527 - Standard pack.  

Code of Federal Regulations, 2013 CFR

...container. (4) “Tightly packed” means the plums or prunes are the proper size for the mold or cell compartments in which they are packed, and the molds or cells are filled in such a way that movement is not allowed. (b) Marking....

2013-01-01

455

Pack rats (Neotoma spp.): Keystone ecological engineers?  

Technology Transfer Automated Retrieval System (TEKTRAN)

The potential role of two species of pack rats (Neotoma albigula and Neotoma micropus) as keystone ecological engineers was examined by estimating the species diversity of invertebrates living in the nest middens, and nitrogen mineralization rates in soils associated with the middens. Although pack-...

456

Mud pack therapy in rheumatoid arthritis  

Microsoft Academic Search

Summary Twenty-eight patients with classical or definite rheumatoid arthritis were randomly divided into two groups of fourteen patients each. All patients were treated once a day with mud packs derived from the Dead Sea heated to 40°C and applied over the four extremities, neck and back for 20 minutes. Group 1 was treated with the true mud packs and Group

S. Sukenik; D. Buskila; L. Neumann; A. Kleiner-Baumgarten

1992-01-01

457

Rectangle-packing-based module placement  

Microsoft Academic Search

The first and the most critical stage in VLSI layout design is the placement, the background of which is the rectangle packing problem: Given many rectangular modules of arbitrary size, place them without overlapping on a layer in the smallest bounding rectangle. Since the variety of the packing is infinite (two- dimensionally continuous) many, the key issue for successful optimization

Hiroshi Murata; Kunihiro Fujiyoshi; Shigetoshi Nakatake; Yoji Kajitani

1995-01-01

458

Density Column Lab - Part 2  

NSDL National Science Digital Library

Concluding a two-part lab activity, students use triple balance beams and graduated cylinders to take measurements and calculate densities of several household liquids and compare them to the densities of irregularly shaped objects (as determined in Part 1). Then they create density columns with the three liquids and four solid items to test their calculations and predictions of the different densities. Once their density columns are complete, students determine the effect of adding detergent to the columns. After this activity, present the associated Density & Miscibility lesson for a discussion about why the column layers do not mix.

GK-12 Program,

459

Compact electron beam focusing column  

SciTech Connect

A novel design for an electron beam focusing column has been developed at LBNL. The design is based on a low-energy spread multicusp plasma source which is used as a cathode for electron beam production. The focusing column is 10 mm in length. The electron beam is focused by means of electrostatic fields. The column is designed for a maximum voltage of 50 kV. Simulations of the electron trajectories have been performed by using the 2-D simulation code IGUN and EGUN. The electron temperature has also been incorporated into the simulations. The electron beam simulations, column design and fabrication will be discussed in this presentation.

Persaud, Arun; Leung, Ka-Ngo; Reijonen, Jani

2001-07-13

460

Five-Layer Density Column  

NSDL National Science Digital Library

In this activity, learners can create five-layer density columns by employing one of three (or all) methods. Method 1 gives the names of the liquids and the order for adding them, and its goal is to directly construct the density column without any experimentation. Method 2 assumes names and densities of the five materials to be unknown, and involves open-ended experimenting, with few instructions, to construct the column. Method 3 also assumes names and densities of the materials to be unknown, and outlines a systematic way to approach the experimentation involved in constructing the column. Learners complete data tables and analyze the densities of the substances.

Rathjen, Don

2005-01-01

461

Coalescence preference in densely packed microbubbles.  

PubMed

A bubble merged from two parent bubbles with different size tends to be placed closer to the larger parent. This phenomenon is known as the coalescence preference. Here we demonstrate that the coalescence preference can be blocked inside a densely packed cluster of bubbles. We utilized high-speed high-resolution X-ray microscopy to clearly visualize individual coalescence events inside densely packed microbubbles with a local packing fraction of ~40%. The surface energy release theory predicts an exponent of 5 in a relation between the relative coalescence position and the parent size ratio, whereas our observation for coalescence in densely packed microbubbles shows a different exponent of 2. We believe that this result would be important to understand the reality of coalescence dynamics in a variety of packing situations of soft matter. PMID:25583640

Kim, Yeseul; Lim, Su Jin; Gim, Bopil; Weon, Byung Mook

2015-01-01

462

Coalescence preference in densely packed microbubbles  

PubMed Central

A bubble merged from two parent bubbles with different size tends to be placed closer to the larger parent. This phenomenon is known as the coalescence preference. Here we demonstrate that the coalescence preference can be blocked inside a densely packed cluster of bubbles. We utilized high-speed high-resolution X-ray microscopy to clearly visualize individual coalescence events inside densely packed microbubbles with a local packing fraction of ~40%. The surface energy release theory predicts an exponent of 5 in a relation between the relative coalescence position and the parent size ratio, whereas our observation for coalescence in densely packed microbubbles shows a different exponent of 2. We believe that this result would be important to understand the reality of coalescence dynamics in a variety of packing situations of soft matter. PMID:25583640

Kim, Yeseul; Lim, Su Jin; Gim, Bopil; Weon, Byung Mook

2015-01-01

463

Occurrence of 2,2,4-trimethyl–1,3-pentanediol monoisobutyrate (Texanol®) in foods packed in polystyrene and polypropylene cups  

Microsoft Academic Search

After simultaneous distillation–extraction (SDE) of foods packed in polystyrene (n = 77) and polypropylene cups (n = 42) from 61 different suppliers, coupled capillary gas chromatography–mass spectrometric (HRGC–MS) analyses indicated the presence of diastereomers of 2,2,4-trimethyl–1,3-pentanediol monoisobutyrate (TMPD-MIB; Texanol®), a known coalescent of paints and printing inks. The contaminant was found in 55 and 50% of the polystyrene and polypropylene

M. Kempf; S. Ramm; T. Feuerbach; P. Schreier

2009-01-01

464

Improvement of separation efficiencies of anion-exchange chromatography using monolithic silica capillary columns modified with polyacrylates and polymethacrylates containing tertiary amino or quaternary ammonium groups.  

PubMed

Anion-exchange (AEX) columns were prepared by on-column polymerization of acrylates and methacrylates containing tertiary amino or quaternary ammonium groups on monolithic silica in a fused silica capillary modified with anchor groups. The columns provided a plate height (H) of less than 10 microm at optimum linear velocity (u) with keeping their high permeability (K=9-12 x 10(-14) m2). Among seven kinds of AEX columns, a monolithic silica column modified with poly(2-hydroxy-3-(4-methylpiperazin-1-yl)propyl methacrylates) (HMPMA) showed larger retentions and better selectivities for nucleotides and inorganic anions than the others. The HMPMA column of 410 mm length produced 42,000-55,000 theoretical plates (N) at a linear velocity of 0.97 mm/s with a backpressure of 3.8 MPa. The same column could be employed for a fast separation of inorganic anions in 1.8 min at a linear velocity of 5.3 mm/s with a backpressure of 20 MPa. In terms of van Deemter plot and separation impedance, the HMPMA column showed higher performance than a conventional particle-packed AEX column. The HMPMA column showed good recovery of a protein, trypsin inhibitor, and it was applied to the separation of proteins and tryptic digest of bovine serum albumin (BSA) in a gradient elution, to provide better separation compared to a conventional particle-packed AEX column. PMID:19683243

Watanabe, Yuta; Ikegami, Tohru; Horie, Kanta; Hara, Takeshi; Jaafar, Jafariah; Tanaka, Nobuo

2009-10-30

465

Packed Bed Reactor Experiment - Duration: 0:17.  

NASA Video Gallery

The purpose of the Packed Bed Reactor Experiment in low gravity is to determine how a mixture of gas and liquid flows through a packed bed in reduced gravity. A packed bed consists of a metal pipe ...

466

SIGMM Education Column December 2010  

E-print Network

commonly used to analyze and solve multimedia research problems. The course was proposed for two reasons were consulted to identify a common core to go into CS5240. This initial list was still deemed tooSIGMM Education Column December 2010 SIGMM Education Column Authors: Wei Tsang Ooi and Terence Sim

Sim, Terence

467

Monitoring Three-Dimensional Packings in Microgravity  

E-print Network

We present results from experiments with granular packings in three dimensions in microgravity as realized on parabolic flights. Two different techniques are employed to monitor the inside of the packings during compaction: (1) X-ray radiography is used to measure in transmission the integrated fluctuations of particle positions. (2) Stress-birefringence in three dimensions is applied to visualize the stresses inside the packing. The particle motions below the transition into an arrested packing are found to produce a well agitated state. At the transition, the particles lose their energy quite rapidly and form a stress network. With both methods, non-arrested particles (rattlers) can be identified. In particular, it is found that rattlers inside the arrested packing can be excited to appreciable dynamics by the rest-accelerations (g-jitter) during a parabolic flight without destroying the packings. At low rates of compaction, a regime of slow granular cooling is identified. The slow cooling extends over several seconds, is described well by a linear law, and terminates in a rapid final collapse of dynamics before complete arrest of the packing.

Peidong Yu; Stefan Frank-Richter; Alexander Borngen; Matthias Sperl

2013-12-21

468

Azeotropic Distillation as a Technique for Emulsion Size Reduction  

E-print Network

: A solvent with HA Boiling point with water Heptane or Hexane Low vapor pressure viscosifying oil Distillation setup/ process -Found the Heterogeneous Azeotropic Distillation Boiling points for Water on microscope - Took several images at different time points - Took pictures in color also to see what was water

Petta, Jason

469

CHEM333: Experiment 4: Steam Distillation of Essential Oils;  

E-print Network

of an aqueous mixture but at a much lower/ less destructive temperature than distilling the compound directly for a dropping funnel. The water initially in your round bottom flask will be sufficient for the distillation, but they are obviously required. Boil the mixture vigorously, but watch for boil-overs! Collect about 125 m

Taber, Douglass

470

Sorption Isotherm Characteristics of Dried Distillers Grains with Solubles (DDGS)  

Technology Transfer Automated Retrieval System (TEKTRAN)

Distillers Dried Grains with Solubles (DDGS) is widely recognized as a highly nutritious animal feed ingredient. With the exponential growth of the fuel ethanol industry in the past several years, significant quantities of distillers grains are now being produced. To effectively utilize these feeds ...

471

A Hydration of an Alkyne Illustrating Steam and Vacuum Distillation.  

ERIC Educational Resources Information Center

Reports on the conversion 2,5-dimethylhexyne-2,5-diol(I) to 2,2,5,5-tetramethyltetrahydrofuran-3-one(II) using aqueous mercuric sulfate without the use of acid. The experiment has been successfully performed in introductory organic chemistry laboratories demonstrating alkyne hydration, steam distillation, vacuum distillation, drying of organic…

Wasacz, J. P.; Badding, V. G.

1982-01-01

472

Estimation of convective mass transfer in solar distillation systems  

Microsoft Academic Search

In this article a thermal model has been developed to determine the convective mass transfer for different Grashof Number range in solar distillatiOn process. The model is based on simple regression analysis. Based on the experimental data obtained from the rigorous outdoor experimentation on passive and active distillation systems for summer climatic conditions, the values of C and n have

Sanjay Kumar; G. N. Tiwari

1996-01-01

473

Teaching and Learning Distillation in Chemistry Laboratory Courses.  

ERIC Educational Resources Information Center

Distillation in the chemistry laboratory is an essential part of a practicing chemists' and a chemistry educators' work. Nevertheless, regardless of the degree of importance in each of the aforementioned professions, few educational studies on teaching and learning distillation exist. In an effort to rectify this oversight, the Department of…

van Keulen, Hanno; And Others

474

Teaching and Learning Distillation in Chemistry Laboratory Courses.  

ERIC Educational Resources Information Center

Investigated the problems chemistry majors have with learning distillation concepts in traditional chemistry laboratory courses. Reports that students take the generalized concepts at face value, construct decontextualized concepts for distillation, and cannot interpret their observations or make reasoned decisions based on the theoretical…

Keulen, Hanno van; And Others

1995-01-01

475

Modeling the flow properties of distillers dried grains with solubles  

Technology Transfer Automated Retrieval System (TEKTRAN)

Distillers dried grains with solubles (DDGS) are an excellent source of energy, minerals, and bypass protein for ruminants, and are also used in monogastric rations as well. With the remarkable growth of the US fuel ethanol industry in the past decade, large quantities of distillers grains are now b...

476

27 CFR 24.183 - Use of distillates containing aldehydes.  

Code of Federal Regulations, 2012 CFR

...containing aldehydes may be received on wine premises for use in the fermentation of wine and then returned to the distilled spirits plant...Distillates produced from one kind of fruit may not be used in the fermentation of wine made from a different kind of fruit....

2012-04-01

477

27 CFR 24.183 - Use of distillates containing aldehydes.  

Code of Federal Regulations, 2010 CFR

...containing aldehydes may be received on wine premises for use in the fermentation of wine and then returned to the distilled spirits plant...Distillates produced from one kind of fruit may not be used in the fermentation of wine made from a different kind of fruit....

2010-04-01

478

27 CFR 24.183 - Use of distillates containing aldehydes.  

Code of Federal Regulations, 2013 CFR

...containing aldehydes may be received on wine premises for use in the fermentation of wine and then returned to the distilled spirits plant...Distillates produced from one kind of fruit may not be used in the fermentation of wine made from a different kind of fruit....

2013-04-01

479

27 CFR 24.183 - Use of distillates containing aldehydes.  

Code of Federal Regulations, 2011 CFR

...containing aldehydes may be received on wine premises for use in the fermentation of wine and then returned to the distilled spirits plant...Distillates produced from one kind of fruit may not be used in the fermentation of wine made from a different kind of fruit....

2011-04-01

480

27 CFR 24.183 - Use of distillates containing aldehydes.  

Code of Federal Regulations, 2014 CFR

...containing aldehydes may be received on wine premises for use in the fermentation of wine and then returned to the distilled spirits plant...Distillates produced from one kind of fruit may not be used in the fermentation of wine made from a different kind of fruit....

2014-04-01

481

27 CFR 19.203 - Alternation of distilled spirits plant and bonded wine cellar premises.  

Code of Federal Regulations, 2010 CFR

...2010-04-01 false Alternation of distilled spirits plant and bonded wine cellar premises. 19.203...OF THE TREASURY LIQUORS DISTILLED SPIRITS PLANTS Qualification of Distilled Spirits Plants Alternate Operations § 19.203...

2010-04-01

482

27 CFR 19.133 - Use of distilled spirits plant premises.  

Code of Federal Regulations, 2010 CFR

...2010-04-01 false Use of distilled spirits plant premises. 19.133 Section 19.133...TREASURY LIQUORS DISTILLED SPIRITS PLANTS Location and Use § 19.133 Use of distilled spirits plant premises. (a) General. No...

2010-04-01

483

27 CFR 19.204 - Alternation of distilled spirits plant and taxpaid wine bottling house premises.  

Code of Federal Regulations, 2010 CFR

...2010-04-01 false Alternation of distilled spirits plant and taxpaid wine bottling house premises...OF THE TREASURY LIQUORS DISTILLED SPIRITS PLANTS Qualification of Distilled Spirits Plants Alternate Operations § 19.204...

2010-04-01