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Sample records for here-the left column

  1. Hemifield columns co-opt ocular dominance column structure in human achiasma.

    Science.gov (United States)

    Olman, Cheryl A; Bao, Pinglei; Engel, Stephen A; Grant, Andrea N; Purington, Chris; Qiu, Cheng; Schallmo, Michael-Paul; Tjan, Bosco S

    2018-01-01

    In the absence of an optic chiasm, visual input to the right eye is represented in primary visual cortex (V1) in the right hemisphere, while visual input to the left eye activates V1 in the left hemisphere. Retinotopic mapping In V1 reveals that in each hemisphere left and right visual hemifield representations are overlaid (Hoffmann et al., 2012). To explain how overlapping hemifield representations in V1 do not impair vision, we tested the hypothesis that visual projections from nasal and temporal retina create interdigitated left and right visual hemifield representations in V1, similar to the ocular dominance columns observed in neurotypical subjects (Victor et al., 2000). We used high-resolution fMRI at 7T to measure the spatial distribution of responses to left- and right-hemifield stimulation in one achiasmic subject. T 2 -weighted 2D Spin Echo images were acquired at 0.8mm isotropic resolution. The left eye was occluded. To the right eye, a presentation of flickering checkerboards alternated between the left and right visual fields in a blocked stimulus design. The participant performed a demanding orientation-discrimination task at fixation. A general linear model was used to estimate the preference of voxels in V1 to left- and right-hemifield stimulation. The spatial distribution of voxels with significant preference for each hemifield showed interdigitated clusters which densely packed V1 in the right hemisphere. The spatial distribution of hemifield-preference voxels in the achiasmic subject was stable between two days of testing and comparable in scale to that of human ocular dominance columns. These results are the first in vivo evidence showing that visual hemifield representations interdigitate in achiasmic V1 following a similar developmental course to that of ocular dominance columns in V1 with intact optic chiasm. Copyright © 2017 Elsevier Inc. All rights reserved.

  2. Modeling Stone Columns.

    Science.gov (United States)

    Castro, Jorge

    2017-07-11

    This paper reviews the main modeling techniques for stone columns, both ordinary stone columns and geosynthetic-encased stone columns. The paper tries to encompass the more recent advances and recommendations in the topic. Regarding the geometrical model, the main options are the "unit cell", longitudinal gravel trenches in plane strain conditions, cylindrical rings of gravel in axial symmetry conditions, equivalent homogeneous soil with improved properties and three-dimensional models, either a full three-dimensional model or just a three-dimensional row or slice of columns. Some guidelines for obtaining these simplified geometrical models are provided and the particular case of groups of columns under footings is also analyzed. For the latter case, there is a column critical length that is around twice the footing width for non-encased columns in a homogeneous soft soil. In the literature, the column critical length is sometimes given as a function of the column length, which leads to some disparities in its value. Here it is shown that the column critical length mainly depends on the footing dimensions. Some other features related with column modeling are also briefly presented, such as the influence of column installation. Finally, some guidance and recommendations are provided on parameter selection for the study of stone columns.

  3. Posterior Nutcracker Syndrome Associated with Interrupted Left Inferior Vena Cava with Azygos Continuation and Retroaortic Right Renal Vein

    Energy Technology Data Exchange (ETDEWEB)

    Luo, Xiao Li; Zhou, Xiao Dong [Xijing Hospital, Fourth Military Medical University, Shaanxi (China); Qian, Gen Nian; Xiao, Hui; Zhao, Chun Lei [Fuzhou General Hospital, Fujian (China)

    2012-06-15

    Various anatomic anomalies have been considered the causes of nutcracker syndrome (NCS). Posterior NCS refers to the condition, in which vascular narrowing was secondary to the compression of the retroaortic left renal vein while it is crossing between the aorta and the vertebral column. Here, we report an unusual case of posterior NCS associated with a complicated malformation of the interrupted left inferior vena cava with azygos continuation and retroaortic right renal vein, diagnosed by both color Doppler ultrasonography and CT angiography.

  4. Posterior Nutcracker Syndrome Associated with Interrupted Left Inferior Vena Cava with Azygos Continuation and Retroaortic Right Renal Vein

    International Nuclear Information System (INIS)

    Luo, Xiao Li; Zhou, Xiao Dong; Qian, Gen Nian; Xiao, Hui; Zhao, Chun Lei

    2012-01-01

    Various anatomic anomalies have been considered the causes of nutcracker syndrome (NCS). Posterior NCS refers to the condition, in which vascular narrowing was secondary to the compression of the retroaortic left renal vein while it is crossing between the aorta and the vertebral column. Here, we report an unusual case of posterior NCS associated with a complicated malformation of the interrupted left inferior vena cava with azygos continuation and retroaortic right renal vein, diagnosed by both color Doppler ultrasonography and CT angiography.

  5. Control structure selection for energy integrated distillation column

    DEFF Research Database (Denmark)

    Hansen, J.E.; Jørgensen, Sten Bay

    1998-01-01

    This paper treats a case study on control structure selection for an almost binary distillation column. The column is energy integrated with a heat pump in order to transfer heat from the condenser to the reboiler. This integrated plant configuration renders the possible control structures somewhat...... different from what is usual for binary distillation columns. Further the heat pump enables disturbances to propagate faster through the system. The plant has six possible actuators of which three must be used to stabilize the system. Hereby three actuators are left for product purity control. An MILP...

  6. NMFS Water Column Sonar Database

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Water column sonar data are an important component of fishery independent surveys, habitat studies and other research. NMFS water column sonar data are archived here.

  7. Quantitative scintigraphy of the sacroiliac joints and spinal column in Bechterev's disease (spondylitis ankylopoetica)

    International Nuclear Information System (INIS)

    Mlychkov, Kh.

    1982-01-01

    Quantitative scintigraphy of the sacroiliac joints and the spinal column was performed in 138 patients with verified Bechterev's disease and in a control group of 104 healthy subjects, who had no clinical, roentgenographic and laboratory evidence of illness of the sacroiliac joints and the spinal column. By comparing skeletal ''zones of interest'' the author studied the following quantitative parameters: sacroiliac index (separately fop the right and left sacpoiliac joint); C 7 /sacrum jndex; D 10 /sacrum and L 4 /sacrum indices. The main values of these indices in the control group were accordingly 114.5 and 113.7 (for the right and left sacroiliac joints); 59; 95; 90. In patients with Bechterev's disease these indices were raised: 154 and 149 (for right and left sacroiliac joints); 75; 123; 113. Peak diagnostic value have the sacroiliac indices and the D 10 /sacrum, index, which appeared to be elevated in more than 95 per cent of the tested patients with verified Bechterev's disease. (author)

  8. The Position and Mobility of the Shoulder, Spinal Column and Pelvis in Seated Subjects.

    Science.gov (United States)

    1985-02-01

    Considerable muscle atrophy was observed in the right shoulder. In the spinal column, tissues overlying the right sacroiliac joint felt firmer than over...subject #23 had fewer clinical findings for joint dysfunction than in the other two subjects, but the physician noted more soft tissue observations than...There was also a mild scoliotic curvature with left convexity observed at T4-6. n the pelvis, the left lumbosacral and sacroiliac joints seened to

  9. VARIATION IN THE OPENINGS (OSTIA OF LEFT PULMONARY VEINS INTO THE LEFT ATRIUM: A CASE REPORT

    Directory of Open Access Journals (Sweden)

    Sesi

    2015-03-01

    Full Text Available During early embryonic development, absorption of pulmonary venous network by the left primitive atrial chamber results in opening of four pulmonary veins which drain independently into its chamber. The extent of absorption and hence, the number of pulmon ary veins which open into the left atrium, may vary. Here we report a variation in the opening of the Left upper (superior pulmonary vein into the Left atrium. A total of six openings observed

  10. Distillation Column Flooding Predictor

    Energy Technology Data Exchange (ETDEWEB)

    George E. Dzyacky

    2010-11-23

    The Flooding Predictor™ is a patented advanced control technology proven in research at the Separations Research Program, University of Texas at Austin, to increase distillation column throughput by over 6%, while also increasing energy efficiency by 10%. The research was conducted under a U. S. Department of Energy Cooperative Agreement awarded to George Dzyacky of 2ndpoint, LLC. The Flooding Predictor™ works by detecting the incipient flood point and controlling the column closer to its actual hydraulic limit than historical practices have allowed. Further, the technology uses existing column instrumentation, meaning no additional refining infrastructure is required. Refiners often push distillation columns to maximize throughput, improve separation, or simply to achieve day-to-day optimization. Attempting to achieve such operating objectives is a tricky undertaking that can result in flooding. Operators and advanced control strategies alike rely on the conventional use of delta-pressure instrumentation to approximate the column’s approach to flood. But column delta-pressure is more an inference of the column’s approach to flood than it is an actual measurement of it. As a consequence, delta pressure limits are established conservatively in order to operate in a regime where the column is never expected to flood. As a result, there is much “left on the table” when operating in such a regime, i.e. the capacity difference between controlling the column to an upper delta-pressure limit and controlling it to the actual hydraulic limit. The Flooding Predictor™, an innovative pattern recognition technology, controls columns at their actual hydraulic limit, which research shows leads to a throughput increase of over 6%. Controlling closer to the hydraulic limit also permits operation in a sweet spot of increased energy-efficiency. In this region of increased column loading, the Flooding Predictor is able to exploit the benefits of higher liquid

  11. Hydrogen production in the K-Basin ion exchange columns, modules and cartridge filters

    International Nuclear Information System (INIS)

    1994-01-01

    K-Basin uses ion exchange modules and ion exchange (IX) columns for removing radionuclides from the basin water. When the columns and modules are loaded, they are removed from service, drained and stored. After a few IX columns accumulate in storage, they are moved to a burial box. One of the burial box contains 33 columns and the other, six. The radionuclides act on the liquid left within and adhering to the beads to produce hydrogen. This report describes the generation rate, accumulation rate and significance of that accumulation. This summary also highlights those major areas of concern to the external (to Westinghouse Hanford Company [WHC]) reviewers. Appendix H presents the comments made by the external reviewers and, on a separate sheet, the responses to those comments. The concerns regarding the details of the analytical approach, are addressed in Appendix H and in the appropriate section

  12. Hydrogen production in the K-Basin ion exchange columns, modules and cartridge filters

    Energy Technology Data Exchange (ETDEWEB)

    1994-12-21

    K-Basin uses ion exchange modules and ion exchange (IX) columns for removing radionuclides from the basin water. When the columns and modules are loaded, they are removed from service, drained and stored. After a few IX columns accumulate in storage, they are moved to a burial box. One of the burial box contains 33 columns and the other, six. The radionuclides act on the liquid left within and adhering to the beads to produce hydrogen. This report describes the generation rate, accumulation rate and significance of that accumulation. This summary also highlights those major areas of concern to the external (to Westinghouse Hanford Company [WHC]) reviewers. Appendix H presents the comments made by the external reviewers and, on a separate sheet, the responses to those comments. The concerns regarding the details of the analytical approach, are addressed in Appendix H and in the appropriate section.

  13. Insights into Tikhonov regularization: application to trace gas column retrieval and the efficient calculation of total column averaging kernels

    Directory of Open Access Journals (Sweden)

    T. Borsdorff

    2014-02-01

    Full Text Available Insights are given into Tikhonov regularization and its application to the retrieval of vertical column densities of atmospheric trace gases from remote sensing measurements. The study builds upon the equivalence of the least-squares profile-scaling approach and Tikhonov regularization method of the first kind with an infinite regularization strength. Here, the vertical profile is expressed relative to a reference profile. On the basis of this, we propose a new algorithm as an extension of the least-squares profile scaling which permits the calculation of total column averaging kernels on arbitrary vertical grids using an analytic expression. Moreover, we discuss the effective null space of the retrieval, which comprises those parts of a vertical trace gas distribution which cannot be inferred from the measurements. Numerically the algorithm can be implemented in a robust and efficient manner. In particular for operational data processing with challenging demands on processing time, the proposed inversion method in combination with highly efficient forward models is an asset. For demonstration purposes, we apply the algorithm to CO column retrieval from simulated measurements in the 2.3 μm spectral region and to O3 column retrieval from the UV. These represent ideal measurements of a series of spaceborne spectrometers such as SCIAMACHY, TROPOMI, GOME, and GOME-2. For both spectral ranges, we consider clear-sky and cloudy scenes where clouds are modelled as an elevated Lambertian surface. Here, the smoothing error for the clear-sky and cloudy atmosphere is significant and reaches several percent, depending on the reference profile which is used for scaling. This underlines the importance of the column averaging kernel for a proper interpretation of retrieved column densities. Furthermore, we show that the smoothing due to regularization can be underestimated by calculating the column averaging kernel on a too coarse vertical grid. For both

  14. Assembly for connecting the column ends of two capillary columns

    International Nuclear Information System (INIS)

    Kolb, B.; Auer, M.; Pospisil, P.

    1984-01-01

    In gas chromatography, the column ends of two capillary columns are inserted into a straight capillary from both sides forming annular gaps. The capillary is located in a tee out of which the capillary columns are sealingly guided, and to which carrier gas is supplied by means of a flushing flow conduit. A ''straight-forward operation'' having capillary columns connected in series and a ''flush-back operation'' are possible. The dead volume between the capillary columns can be kept small

  15. Revision and simplification of the boarding previous minimum of the lumbar column

    International Nuclear Information System (INIS)

    Lazannec, JY; Del Vecchio, R; Ramare, S; Saillant, G

    2001-01-01

    This paper describes the boarding retroperineal previous minimum, which provides access at any level discal and vertebral between T12 and S1. It is carried out a technique of dissection retroperineal that facilitates the renal and duodenum-pancreatic mobilization to consent to the face previous left of the whole lumbar column and of the thoracic-lumbar union. They were carried out careful anatomical dissections in fresh cadavers and preserved to determine the topography and the anatomical relationships of interest and this way to develop a sure boarding and easily reproducible. Special attention has been paid to the description of the lumbar veins and the anastomosis between the vein renal left and the hemiacigos system for the exhibition of the expensive left anterolateral of T12 and L1. A series of 94 patients is reported with lesions caused by traumas or degenerative processes. For all the lumbar levels, even in-patient with antecedents of surgery intraperitoneal, the boarding minimum retroperitoneal, was safe for the kidneys, ureters, spleen, hypo gastric plexus and duodenum-pancreatic union. Better cosmetic results are reported, decrease of the time surgical, scarce bled intraoperatory and easiness for the decortications and placement of implants. The previous boarding minimum retro peritoneal of the column developed starting from the boarding classic retroperineals, offers significant advantages on the endoscopic techniques, which require sophisticated machinery and they are technically plaintiffs. The exhibition of all the lumbar levels, as well as the reduction maneuvers and placement of implants, they can be carried out with easiness without causing muscular damage

  16. Buckling of liquid columns

    NARCIS (Netherlands)

    Habibi, M.; Rahmani, Y.; Bonn, D.; Ribe, N.M.

    2010-01-01

    Under appropriate conditions, a column of viscous liquid falling onto a rigid surface undergoes a buckling instability. Here we show experimentally and theoretically that liquid buckling exhibits a hitherto unsuspected complexity involving three different modes—viscous, gravitational, and

  17. Column-to-column packing variation of disposable pre-packed columns for protein chromatography.

    Science.gov (United States)

    Schweiger, Susanne; Hinterberger, Stephan; Jungbauer, Alois

    2017-12-08

    In the biopharmaceutical industry, pre-packed columns are the standard for process development, but they must be qualified before use in experimental studies to confirm the required performance of the packed bed. Column qualification is commonly done by pulse response experiments and depends highly on the experimental testing conditions. Additionally, the peak analysis method, the variation in the 3D packing structure of the bed, and the measurement precision of the workstation influence the outcome of qualification runs. While a full body of literature on these factors is available for HPLC columns, no comparable studies exist for preparative columns for protein chromatography. We quantified the influence of these parameters for commercially available pre-packed and self-packed columns of disposable and non-disposable design. Pulse response experiments were performed on 105 preparative chromatography columns with volumes of 0.2-20ml. The analyte acetone was studied at six different superficial velocities (30, 60, 100, 150, 250 and 500cm/h). The column-to-column packing variation between disposable pre-packed columns of different diameter-length combinations varied by 10-15%, which was acceptable for the intended use. The column-to-column variation cannot be explained by the packing density, but is interpreted as a difference in particle arrangement in the column. Since it was possible to determine differences in the column-to-column performance, we concluded that the columns were well-packed. The measurement precision of the chromatography workstation was independent of the column volume and was in a range of±0.01ml for the first peak moment and±0.007 ml 2 for the second moment. The measurement precision must be considered for small columns in the range of 2ml or less. The efficiency of disposable pre-packed columns was equal or better than that of self-packed columns. Copyright © 2017 The Author(s). Published by Elsevier B.V. All rights reserved.

  18. Local buckling of composite channel columns

    Science.gov (United States)

    Szymczak, Czesław; Kujawa, Marcin

    2018-05-01

    The investigation concerns local buckling of compressed flanges of axially compressed composite channel columns. Cooperation of the member flange and web is taken into account here. The buckling mode of the member flange is defined by rotation angle a flange about the line of its connection with the web. The channel column under investigation is made of unidirectional fibre-reinforced laminate. Two approaches to member orthotropic material modelling are performed: the homogenization with the aid of theory of mixture and periodicity cell or homogenization upon the Voigt-Reuss hypothesis. The fundamental differential equation of local buckling is derived with the aid of the stationary total potential energy principle. The critical buckling stress corresponding to a number of buckling half-waves is assumed to be a minimum eigenvalue of the equation. Some numerical examples dealing with columns are given here. The analytical results are compared with the finite element stability analysis carried out by means of ABAQUS software. The paper is focused on a close analytical solution of the critical buckling stress and the associated buckling mode while the web-flange cooperation is assumed.

  19. Varied overstrain injuries of the vertebral column conditioned by evolution

    Energy Technology Data Exchange (ETDEWEB)

    Kohlbach, W

    1983-08-01

    During physiological growth of the juvenile vertebral column, various stages of stability occur which are characterized by the condition of the marginal rim of the vertebral bodies. If the vertebral juvenile column is overstrained, these variations in stability results in a variety of damage to vertebral bodies and vertebral disks. One of these lesions corresponds to Scheuermann's disease (osteochondrosis of vertebral epiphyses in juveniles). Damage of the vertebral column due to overstrain can occur only if the overstrain is applied in upright position. Since Man alone can damage his vertebral column in upright position (as a result of his evolutionary development), Scheuermann's thesis is confirmed that Scheuermann's disease is confined to Man. Spondylolysis/spondylolisthesis is also a damage caused by overstrain. Here, too, the damage can occur only if the load is exercised in upright position, with the exception of a slanted positioning of the intervertebral components.

  20. Varied overstrain injuries of the vertebral column conditioned by evolution

    International Nuclear Information System (INIS)

    Kohlbach, W.

    1983-01-01

    During physiological growth of the juvenile vertebral column, various stages of stability occur which are characterized by the condition of the marginal rim of the vertebral bodies. If the vertebral juvenile column is overstrained, these variations in stability results in a variety of damage to vertebral bodies and vertebral disks. One of these lesions corresponds to Scheuermann's disease (osteochondrosis of vertebral epiphyses in juveniles). Damage of the vertebral column due to overstrain can occur only if the overstrain is applied in upright position. Since Man alone can damage his vertebral column in upright position (as a result of his evolutionary development), Scheuermann's thesis is confirmed that Scheuermann's disease is confined to Man. Spondylolysis/spondylolisthesis is also a damage caused by overstrain. Here, too, the damage can occur only if the load is exercised in upright position, with the exception of a slanted positioning of the intervertebral components. (orig.) [de

  1. Admittance Scanning for Whole Column Detection.

    Science.gov (United States)

    Stamos, Brian N; Dasgupta, Purnendu K; Ohira, Shin-Ichi

    2017-07-05

    Whole column detection (WCD) is as old as chromatography itself. WCD requires an ability to interrogate column contents from the outside. Other than the obvious case of optical detection through a transparent column, admittance (often termed contactless conductance) measurements can also sense changes in the column contents (especially ionic content) from the outside without galvanic contact with the solution. We propose here electromechanically scanned admittance imaging and apply this to open tubular (OT) chromatography. The detector scans across the column; the length resolution depends on the scanning velocity and the data acquisition frequency, ultimately limited by the physical step resolution (40 μm in the present setup). Precision equal to this step resolution was observed for locating an interface between two immiscible liquids inside a 21 μm capillary. Mechanically, the maximum scanning speed was 100 mm/s, but at 1 kHz sampling rate and a time constant of 25 ms, the highest practical scan speed (no peak distortion) was 28 mm/s. At scanning speeds of 0, 4, and 28 mm/s, the S/N for 180 pL (zone length of 1.9 mm in a 11 μm i.d. column) of 500 μM KCl injected into water was 6450, 3850, and 1500, respectively. To facilitate constant and reproducible contact with the column regardless of minor variations in outer diameter, a double quadrupole electrode system was developed. Columns of significant length (>1 m) can be readily scanned. We demonstrate its applicability with both OT and commercial packed columns and explore uniformity of retention along a column, increasing S/N by stopped-flow repeat scans, etc. as unique applications.

  2. Varied overstrain injuries of the vertebral column conditioned by evolution

    Energy Technology Data Exchange (ETDEWEB)

    Kohlbach, W.

    1983-08-01

    During physiological growth of the juvenile vertebral column, various stages of stability occur which are characterized by the condition of the marginal rim of the vertebral bodies. If the vertebral juvenile column is overstrained, these variations in stability results in a variety of damage to vertebral bodies and vertebral disks. One of these lesions corresponds to Scheuermann's disease (osteochondrosis of vertebral epiphyses in juveniles). Damage of the vertebral column due to overstrain can occur only if the overstrain is applied in upright position. Since Man alone can damage his vertebral column in upright position (as a result of his evolutionary development), Scheuermann's thesis is confirmed that Scheuermann's disease is confined to Man. Spondylolysis/spondylolisthesis is also a damage caused by overstrain. Here, too, the damage can occur only if the load is exercised in upright position, with the exception of a slanted positioning of the intervertebral components.

  3. Water column methanotrophy controlled by a rapid oceanographic switch

    NARCIS (Netherlands)

    Steinle, L.; Graves, C.A.; Treude, T.; Ferré, B.; Biastoch, A.; Bussmann, I.; Berndt, C.; Krastel, S.; James, R.H.; Behrens, E.; Böning, C.W.; Greinert, J.; Sapart, C.-J.; Scheinert, M.; Sommer, S.; Lehmann, M.F.; Niemann, H.

    2015-01-01

    From the seabed to the water column, where it may be consumed by aerobic methanotrophic bacteria. The size and activity of methanotrophic communities, which determine the amount of methane consumed in the water column,are thought to be mainly controlled by nutrient and redoxdynamics3–7. Here, we

  4. "Happy Days Are Here Again": A Left and Right Brain 4MAT Approach to Teaching Depression-Era Presidential Elections.

    Science.gov (United States)

    Cantu, D. Antonio

    2001-01-01

    Provides a lesson plan that focuses on the 1932, 1936, and 1940 presidential election campaigns. Illustrates the use of the left and right brain 4MAT teaching model that considers individual learning styles associated with right and left hemisphere dominance. Includes a bibliography and eight handouts. (CMK)

  5. Posterior Vertebral Column Resection Through Unilateral Osteotomy Approach for Old Lumbar Fracture Combined with Kummell Disease.

    Science.gov (United States)

    Wang, Hui; Ding, Wenyuan

    2018-01-01

    Kummell disease is a clinical syndrome characterized by minor spinal trauma with a symptom-free period from months to years, followed by progressive painful kyphosis. Many surgical options for Kummell disease have been reported in the previous literature; however, no study has mentioned the surgical strategy for patients whose fractured vertebrae were severely compressed and only a slice of superior and inferior end plate was left. Here we report the case of a 69-year-old woman who suffered persistent severe back pain since she slipped and fell 1 year before medical consult. The patient presented with constrained body posture and pressure pain on the thoracolumbar region. Visual analog scale pain under weight bearing was 90/100, and her Oswestry Disability Index score was 74%. Kummell disease was diagnosed on the basis of clinical presentation, trauma history, radiograph, computed tomography, and magnetic resonance imaging. We performed the posterior vertebral column resection through the unilateral osteotomy approach for the patient, and the clinical outcome and radiologic restoration were recorded. One year after the surgery, outpatient follow-up review revealed that the visual analog scale reduced to 10/100 and Oswestry Disability Index reduced to 13%. The posteroanterior and lateral radiograph in the standing position showed bony fusion was achieved at the osteotomy site. No pseudarthrosis or instrumentation-related failure occurred. Posterior vertebral column resection through unilateral osteotomy approach is an effective method for patients with Kummell disease, especially when the fractured vertebrae compressed severely and only a slice of superior and inferior end plate was left. Copyright © 2017 Elsevier Inc. All rights reserved.

  6. Temperature-assisted On-column Solute Focusing: A General Method to Reduce Pre-column Dispersion in Capillary High Performance Liquid Chromatography

    Science.gov (United States)

    Groskreutz, Stephen R.; Weber, Stephen G.

    2014-01-01

    Solvent-based on-column focusing is a powerful and well known approach for reducingthe impact of pre-column dispersion in liquid chromatography. Here we describe an orthogonal temperature-based approach to focusing called temperature-assisted on-column solute focusing (TASF). TASF is founded on the same principles as the more commonly used solvent-based method wherein transient conditions are created thatlead to high solute retention at the column inlet. Combining the low thermal mass of capillary columns and the temperature dependence of solute retentionTASF is used effectivelyto compress injection bands at the head of the column through the transient reduction in column temperature to 5 °C for a defined 7 mm segment of a 6 cm long 150 μm I.D. column. Following the 30 second focusing time, the column temperature is increased rapidly to the separation temperature of 60 °C releasing the focused band of analytes. We developed a model tosimulate TASF separations based on solute retention enthalpies, focusing temperature, focusing time, and column parameters. This model guides the systematic study of the influence of sample injection volume on column performance.All samples have solvent compositions matching the mobile phase. Over the 45 to 1050 nL injection volume range evaluated, TASF reducesthe peak width for all soluteswith k’ greater than or equal to 2.5, relative to controls. Peak widths resulting from injection volumes up to 1.3 times the column fluid volume with TASF are less than 5% larger than peak widths from a 45 nL injection without TASF (0.07 times the column liquid volume). The TASF approach reduced concentration detection limits by a factor of 12.5 relative to a small volume injection for low concentration samples. TASF is orthogonal to the solvent focusing method. Thus, it canbe used where on-column focusing is required, but where implementation of solvent-based focusing is difficult. PMID:24973805

  7. Mitigating oil spills in the water column

    International Nuclear Information System (INIS)

    Barry, Edward; Libera, Joseph A.; Mane, Anil University; Avila, Jason R.; DeVitis, David

    2017-01-01

    The scale and scope of uncontrolled oil spills can be devastating. Diverse marine environments and fragile ecologies are some of the most susceptible to the many ill effects, while the economic costs can be crippling. A notoriously difficult challenge with no known technological solution is the successful removal of oil dispersed in the water column. Here, we address this problem through cheap and reusable oil sorbents based on the chemical modification of polymer foams. Interfacial chemistry was optimized and subsequently tested in a simulated marine environment at the National Oil Spill Response Research & Renewable Energy Test Facility, Ohmsett. We find favorable performance for surface oil mitigation and, for the first time, demonstrate the advanced sorbent's efficiency and efficacy at pilot scale in extraction of crude oil and refined petroleum products dispersed in the water column. As a result, this is a potentially disruptive technology, opening a new field of environmental science focused on sub-surface pollutant sequestration.

  8. ON THE ORIGIN OF THE HIGH COLUMN DENSITY TURNOVER IN THE H I COLUMN DENSITY DISTRIBUTION

    International Nuclear Information System (INIS)

    Erkal, Denis; Gnedin, Nickolay Y.; Kravtsov, Andrey V.

    2012-01-01

    We study the high column density regime of the H I column density distribution function and argue that there are two distinct features: a turnover at N H I ≈ 10 21 cm –2 , which is present at both z = 0 and z ≈ 3, and a lack of systems above N H I ≈ 10 22 cm –2 at z = 0. Using observations of the column density distribution, we argue that the H I-H 2 transition does not cause the turnover at N H I ≈ 10 21 cm –2 but can plausibly explain the turnover at N H I ∼> 10 22 cm –2 . We compute the H I column density distribution of individual galaxies in the THINGS sample and show that the turnover column density depends only weakly on metallicity. Furthermore, we show that the column density distribution of galaxies, corrected for inclination, is insensitive to the resolution of the H I map or to averaging in radial shells. Our results indicate that the similarity of H I column density distributions at z = 3 and 0 is due to the similarity of the maximum H I surface densities of high-z and low-z disks, set presumably by universal processes that shape properties of the gaseous disks of galaxies. Using fully cosmological simulations, we explore other candidate physical mechanisms that could produce a turnover in the column density distribution. We show that while turbulence within giant molecular clouds cannot affect the damped Lyα column density distribution, stellar feedback can affect it significantly if the feedback is sufficiently effective in removing gas from the central 2-3 kpc of high-redshift galaxies. Finally, we argue that it is meaningful to compare column densities averaged over ∼ kpc scales with those estimated from quasar spectra that probe sub-pc scales due to the steep power spectrum of H I column density fluctuations observed in nearby galaxies.

  9. Final design and construction issues of the TAPIRO epithermal column

    International Nuclear Information System (INIS)

    Burn, K.W.; Casalini, L.; Nava, E.; Tinti, R.; Martini, S.; Mondini, D.; Rosi, G.

    2006-01-01

    The construction of the epithermal column for clinical trials at the 5 kW fast reactor TAPIRO (ENEA, Casaccia, Italy) has been completed, the experimental bunker in the reactor hall has been designed and the beam characterisation will shortly be underway. As has been reviewed at the last two ICNCT conferences, the low power of the neuron source and the relatively distant patient position outside the reactor shield led to a column design with certain characteristics. One consequence is the employment of a collimator containing lead of high purity with the resultant problems of mechanical construction. Another is the substantial neutron leakage from the column outside the aperture into the experimental bunker. Furthermore the absence of a gamma shield has led to an electron dose to the skin. This is resolved with an electron shield of aluminium. Here the construction and final design issues are discussed and the state of the project is presented. (author)

  10. Post column derivatisation analyses review. Is post-column derivatisation incompatible with modern HPLC columns?

    Science.gov (United States)

    Jones, Andrew; Pravadali-Cekic, Sercan; Dennis, Gary R; Shalliker, R Andrew

    2015-08-19

    Post Column derivatisation (PCD) coupled with high performance liquid chromatography or ultra-high performance liquid chromatography is a powerful tool in the modern analytical laboratory, or at least it should be. One drawback with PCD techniques is the extra post-column dead volume due to reaction coils used to enable adequate reaction time and the mixing of reagents which causes peak broadening, hence a loss of separation power. This loss of efficiency is counter-productive to modern HPLC technologies, -such as UHPLC. We reviewed 87 PCD methods published from 2009 to 2014. We restricted our review to methods published between 2009 and 2014, because we were interested in the uptake of PCD methods in UHPLC environments. Our review focused on a range of system parameters including: column dimensions, stationary phase and particle size, as well as the geometry of the reaction loop. The most commonly used column in the methods investigated was not in fact a modern UHPLC version with sub-2-micron, (or even sub-3-micron) particles, but rather, work-house columns, such as, 250 × 4.6 mm i.d. columns packed with 5 μm C18 particles. Reaction loops were varied, even within the same type of analysis, but the majority of methods employed loop systems with volumes greater than 500 μL. A second part of this review illustrated briefly the effect of dead volume on column performance. The experiment evaluated the change in resolution and separation efficiency of some weak to moderately retained solutes on a 250 × 4.6 mm i.d. column packed with 5 μm particles. The data showed that reaction loops beyond 100 μL resulted in a very serious loss of performance. Our study concluded that practitioners of PCD methods largely avoid the use of UHPLC-type column formats, so yes, very much, PCD is incompatible with the modern HPLC column. Copyright © 2015. Published by Elsevier B.V.

  11. Multi-column adsorption systems with condenser for tritiated water vapor removal

    International Nuclear Information System (INIS)

    Kotoh, Kenji; Kudo, Kazuhiko

    1996-01-01

    Two types of multi-column adsorption system are proposed as the system for removal of tritiated moisture from tritium process gases or/and handling room atmospheres. The types are of recycle use of adsorption columns, and are composed of twin or triplet columns and one condenser which is used for collecting the adsorbed moisture from columns in desorption process. The systems utilize the dry gas from a working column as the purge gas for regenerating a saturated column and appropriate an active column for recovery of the tritiated moisture passing through the condenser. Each column hence needs the additional amount of adsorbent for collecting the moisture from the condenser. In the modeling and design of an adsorption column, it is primary to estimate the necessary amount of a candidate adsorbent for its packed-bed. The performance of the proposed systems is examined here by analyzing the dependence of the necessary amount of adsorbent for their columns on process operational conditions and adsorbent moisture-adsorption characteristics. The result shows that the necessary amount is sensitive to the types of adsorption isotherm, and suggests that these systems should employ adsorbents which exhibit the Langmuir-type isotherms. (author)

  12. Influence of pressure on the properties of chromatographic columns. II. The column hold-up volume.

    Science.gov (United States)

    Gritti, Fabrice; Martin, Michel; Guiochon, Georges

    2005-04-08

    The effect of the local pressure and of the average column pressure on the hold-up column volume was investigated between 1 and 400 bar, from a theoretical and an experimental point of view. Calculations based upon the elasticity of the solids involved (column wall and packing material) and the compressibility of the liquid phase show that the increase of the column hold-up volume with increasing pressure that is observed is correlated with (in order of decreasing importance): (1) the compressibility of the mobile phase (+1 to 5%); (2) in RPLC, the compressibility of the C18-bonded layer on the surface of the silica (+0.5 to 1%); and (3) the expansion of the column tube (columns packed with the pure Resolve silica (0% carbon), the derivatized Resolve-C18 (10% carbon) and the Symmetry-C18 (20% carbon) adsorbents, using water, methanol, or n-pentane as the mobile phase. These solvents have different compressibilities. However, 1% of the relative increase of the column hold-up volume that was observed when the pressure was raised is not accounted for by the compressibilities of either the solvent or the C18-bonded phase. It is due to the influence of the pressure on the retention behavior of thiourea, the compound used as tracer to measure the hold-up volume.

  13. Evaluation of the performance of thermal diffusion column separating binary gas mixtures with continuous draw-off

    International Nuclear Information System (INIS)

    Kitamoto, Asashi; Shimizu, Masami; Takashima, Yoichi

    1977-01-01

    Advanced transport relations involving three column constants, H sup(σ), K sub(c)sup(σ) and K sub(d)sup(σ), are developed to describe the separation performance of a thermal diffusion column with continuous draw-off. These constants were related to some integral functions of velocity profile, temperature distribution, density of gas mixture and characteristic values of transport coefficients. The separation of binary gas mixture by this technique was so effective that three reasonable factors had to be introduced into the column constants in the theory. They are a circulation constant of natural convection, a definition of characteristic mean temperature and a definition of mean composition over the column. The separation performance and the column constants also varied with the distortion of velocity profile due to continuous draw-off from the top or the bottom of column. However, its effect was not large, compared with the other factors mentioned above. The theory presented here makes possible to estimate the separation performance of hot-wire type thermal diffusion column with high accuracy. (auth.)

  14. Sources of water column methylmercury across multiple estuaries in the Northeast U.S.

    Science.gov (United States)

    Balcom, Prentiss H; Schartup, Amina T; Mason, Robert P; Chen, Celia Y

    2015-12-20

    Estuarine water column methylmercury (MeHg) is an important driver of mercury (Hg) bioaccumulation in pelagic organisms and thus it is necessary to understand the sources and processes affecting environmental levels of MeHg. Increases in water column MeHg concentrations can ultimately be transferred to fish consumed by humans, but despite this, the sources of MeHg to the estuarine water column are still poorly understood. Here we evaluate MeHg sources across 4 estuaries and 10 sampling sites and examine the distributions and partitioning of sediment and water column MeHg across a geographic range (Maine to New Jersey). Our study sites present a gradient in the concentrations of sediment, pore water and water column Hg species. Suspended particle MeHg ranged from below detection to 187 pmol g -1 , dissolved MeHg from 0.01 to 0.68 pM, and sediment MeHg from 0.01 to 109 pmol g -1 . Across multiple estuaries, dissolved MeHg correlated with Hg species in the water column, and sediment MeHg correlated with sediment total Hg (HgT). Water column MeHg did not correlate well with sediment Hg across estuaries, indicating that sediment concentrations were not a good predictor of water MeHg concentrations. This is an unexpected finding since it has been shown that MeHg production from inorganic Hg 2+ within sediment is the primary source of MeHg to coastal waters. Additional sources of MeHg regulate water column MeHg levels in some of the shallow estuaries included in this study.

  15. Reciprocal Signaling between the Ectoderm and a Mesendodermal Left-Right Organizer Directs Left-Right Determination in the Sea Urchin Embryo

    Science.gov (United States)

    Bessodes, Nathalie; Haillot, Emmanuel; Duboc, Véronique; Röttinger, Eric; Lahaye, François; Lepage, Thierry

    2012-01-01

    During echinoderm development, expression of nodal on the right side plays a crucial role in positioning of the rudiment on the left side, but the mechanisms that restrict nodal expression to the right side are not known. Here we show that establishment of left-right asymmetry in the sea urchin embryo relies on reciprocal signaling between the ectoderm and a left-right organizer located in the endomesoderm. FGF/ERK and BMP2/4 signaling are required to initiate nodal expression in this organizer, while Delta/Notch signaling is required to suppress formation of this organizer on the left side of the archenteron. Furthermore, we report that the H+/K+-ATPase is critically required in the Notch signaling pathway upstream of the S3 cleavage of Notch. Our results identify several novel players and key early steps responsible for initiation, restriction, and propagation of left-right asymmetry during embryogenesis of a non-chordate deuterostome and uncover a functional link between the H+/K+-ATPase and the Notch signaling pathway. PMID:23271979

  16. Modelling aging effects on a thermal cycling absorption process column

    Energy Technology Data Exchange (ETDEWEB)

    Laquerbe, C.; Contreras, S. [Commissariat a l' Energie Atomique - CEA/Valduc, F-21121 Is sur Tille (France); Baudouin, O. [ProSim SA, Stratege Bat. A, BP 27210, F-31672 Labege Cedex (France); Demoment, J. [Commissariat a l' Energie Atomique - CEA/Valduc, F-21121 Is sur Tille (France)

    2008-07-15

    Palladium coated on alumina is used in hydrogen separation systems operated at CEA/Valduc, and more particularly in Thermal Cycling Absorption Process columns. With such materials, tritium decay is known to induce aging effects which have direct side effects on hydrogen isotopes absorption isotherms. Furthermore in a TCAP column, aging occurs in an heterogeneous way. The possible impacts of these intrinsic material evolutions on the separation performances are investigated here through a numerical approach. (authors)

  17. Contributions to reversed-phase column selectivity: III. Column hydrogen-bond basicity.

    Science.gov (United States)

    Carr, P W; Dolan, J W; Dorsey, J G; Snyder, L R; Kirkland, J J

    2015-05-22

    Column selectivity in reversed-phase chromatography (RPC) can be described in terms of the hydrophobic-subtraction model, which recognizes five solute-column interactions that together determine solute retention and column selectivity: hydrophobic, steric, hydrogen bonding of an acceptor solute (i.e., a hydrogen-bond base) by a stationary-phase donor group (i.e., a silanol), hydrogen bonding of a donor solute (e.g., a carboxylic acid) by a stationary-phase acceptor group, and ionic. Of these five interactions, hydrogen bonding between donor solutes (acids) and stationary-phase acceptor groups is the least well understood; the present study aims at resolving this uncertainty, so far as possible. Previous work suggests that there are three distinct stationary-phase sites for hydrogen-bond interaction with carboxylic acids, which we will refer to as column basicity I, II, and III. All RPC columns exhibit a selective retention of carboxylic acids (column basicity I) in varying degree. This now appears to involve an interaction of the solute with a pair of vicinal silanols in the stationary phase. For some type-A columns, an additional basic site (column basicity II) is similar to that for column basicity I in primarily affecting the retention of carboxylic acids. The latter site appears to be associated with metal contamination of the silica. Finally, for embedded-polar-group (EPG) columns, the polar group can serve as a proton acceptor (column basicity III) for acids, phenols, and other donor solutes. Copyright © 2015 Elsevier B.V. All rights reserved.

  18. Center column design of the PLT

    International Nuclear Information System (INIS)

    Citrolo, J.; Frankenberg, J.

    1975-01-01

    The center column of the PLT machine is a secondary support member for the toroidal field coils. Its purpose is to decrease the bending moment at the nose of the coils. The center column design was to have been a stainless steel casting with the toroidal field coils grouped around the casting at installation, trapping it in place. However, the castings developed cracks during fabrication and were unsuitable for use. Installation of the coils proceeded without the center column. It then became necessary to redesign a center column which would be capable of installation with the toroidal field coils in place. The final design consists of three A-286 forgings. This paper discusses the final center column design and the influence that new knowledge, obtained during the power tests, had on the new design

  19. JCE Feature Columns

    Science.gov (United States)

    Holmes, Jon L.

    1999-05-01

    The Features area of JCE Online is now readily accessible through a single click from our home page. In the Features area each column is linked to its own home page. These column home pages also have links to them from the online Journal Table of Contents pages or from any article published as part of that feature column. Using these links you can easily find abstracts of additional articles that are related by topic. Of course, JCE Online+ subscribers are then just one click away from the entire article. Finding related articles is easy because each feature column "site" contains links to the online abstracts of all the articles that have appeared in the column. In addition, you can find the mission statement for the column and the email link to the column editor that I mentioned above. At the discretion of its editor, a feature column site may contain additional resources. As an example, the Chemical Information Instructor column edited by Arleen Somerville will have a periodically updated bibliography of resources for teaching and using chemical information. Due to the increase in the number of these resources available on the WWW, it only makes sense to publish this information online so that you can get to these resources with a simple click of the mouse. We expect that there will soon be additional information and resources at several other feature column sites. Following in the footsteps of the Chemical Information Instructor, up-to-date bibliographies and links to related online resources can be made available. We hope to extend the online component of our feature columns with moderated online discussion forums. If you have a suggestion for an online resource you would like to see included, let the feature editor or JCE Online (jceonline@chem.wisc.edu) know about it. JCE Internet Features JCE Internet also has several feature columns: Chemical Education Resource Shelf, Conceptual Questions and Challenge Problems, Equipment Buyers Guide, Hal's Picks, Mathcad

  20. The handedness of historiated spiral columns.

    Science.gov (United States)

    Couzin, Robert

    2017-09-01

    Trajan's Column in Rome (AD 113) was the model for a modest number of other spiral columns decorated with figural, narrative imagery from antiquity to the present day. Most of these wind upwards to the right, often with a congruent spiral staircase within. A brief introductory consideration of antique screw direction in mechanical devices and fluted columns suggests that the former may have been affected by the handedness of designers and the latter by a preference for symmetry. However, for the historiated columns that are the main focus of this article, the determining factor was likely script direction. The manner in which this operated is considered, as well as competing mechanisms that might explain exceptions. A related phenomenon is the reversal of the spiral in a non-trivial number of reproductions of the antique columns, from Roman coinage to Renaissance and baroque drawings and engravings. Finally, the consistent inattention in academic literature to the spiral direction of historiated columns and the repeated publication of erroneous earlier reproductions warrants further consideration.

  1. Column experiments on organic micropollutants - applications and limitations

    Science.gov (United States)

    Banzhaf, Stefan; Hebig, Klaus

    2016-04-01

    As organic micropollutants become more and more ubiquitous in the aquatic environment, a sound understanding of their fate and transport behaviour is needed. This is to assure both safe and clean drinking water supply for mankind in the future and to protect the aquatic environment from pollution and negative consequences caused by manmade contamination. Apart from countless field studies, column experiments were and are frequently used to study transport of organic micropollutants. As the transport of (organic) solutes in groundwater is controlled by the chemical and physical properties of the compounds, the solvent (the groundwater including all solutes), and the substrate (the aquifer material), the adjustment and control of these boundary conditions allow to study a multitude of different experimental setups and to address specific research questions. The main purpose, however, remains to study the transport of a specific compound and its sorption and degradation behaviour in a specific sediment or substrate. Apart from the effective control of the individual boundary conditions, the main advantage of columns studies compared to other experimental setups (such as field studies, batch/microcosm studies), is that conservative and reactive solute breakthrough curves are obtained, which represent the sum of the transport processes. The analysis of these curves is well-developed and established. Additionally, limitations of this experimental method are presented here: the effects observed in column studies are often a result of dynamic, non-equilibrium processes. Time (or flow velocity) plays a major role in contrast to batch experiments, in which all processes will be observed until equilibrium is reached in the substrate-solution-system. Slightly modifying boundary conditions in different experiments have a strong influence on transport and degradation behaviour of organic micropollutants. This is a significant severe issue when it comes to general findings on the

  2. High-field fMRI unveils orientation columns in humans.

    Science.gov (United States)

    Yacoub, Essa; Harel, Noam; Ugurbil, Kâmil

    2008-07-29

    Functional (f)MRI has revolutionized the field of human brain research. fMRI can noninvasively map the spatial architecture of brain function via localized increases in blood flow after sensory or cognitive stimulation. Recent advances in fMRI have led to enhanced sensitivity and spatial accuracy of the measured signals, indicating the possibility of detecting small neuronal ensembles that constitute fundamental computational units in the brain, such as cortical columns. Orientation columns in visual cortex are perhaps the best known example of such a functional organization in the brain. They cannot be discerned via anatomical characteristics, as with ocular dominance columns. Instead, the elucidation of their organization requires functional imaging methods. However, because of insufficient sensitivity, spatial accuracy, and image resolution of the available mapping techniques, thus far, they have not been detected in humans. Here, we demonstrate, by using high-field (7-T) fMRI, the existence and spatial features of orientation- selective columns in humans. Striking similarities were found with the known spatial features of these columns in monkeys. In addition, we found that a larger number of orientation columns are devoted to processing orientations around 90 degrees (vertical stimuli with horizontal motion), whereas relatively similar fMRI signal changes were observed across any given active column. With the current proliferation of high-field MRI systems and constant evolution of fMRI techniques, this study heralds the exciting prospect of exploring unmapped and/or unknown columnar level functional organizations in the human brain.

  3. A simple, fast, and accurate thermodynamic-based approach for transfer and prediction of gas chromatography retention times between columns and instruments Part III: Retention time prediction on target column.

    Science.gov (United States)

    Hou, Siyuan; Stevenson, Keisean A J M; Harynuk, James J

    2018-03-27

    This is the third part of a three-part series of papers. In Part I, we presented a method for determining the actual effective geometry of a reference column as well as the thermodynamic-based parameters of a set of probe compounds in an in-house mixture. Part II introduced an approach for estimating the actual effective geometry of a target column by collecting retention data of the same mixture of probe compounds on the target column and using their thermodynamic parameters, acquired on the reference column, as a bridge between both systems. Part III, presented here, demonstrates the retention time transfer and prediction from the reference column to the target column using experimental data for a separate mixture of compounds. To predict the retention time of a new compound, we first estimate its thermodynamic-based parameters on the reference column (using geometric parameters determined previously). The compound's retention time on a second column (of previously determined geometry) is then predicted. The models and the associated optimization algorithms were tested using simulated and experimental data. The accuracy of predicted retention times shows that the proposed approach is simple, fast, and accurate for retention time transfer and prediction between gas chromatography columns. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  4. Tritium Isotope Separation Using Adsorption-Distillation Column

    International Nuclear Information System (INIS)

    Fukada, Satoshi

    2005-01-01

    In order to miniaturize the height of a distillation tower for the detritiation of waste water from fusion reactors, two experiments were conducted: (1) liquid frontal chromatography of tritium water eluting through an adsorption column and (2) water distillation using a column packed with adsorbent particles. The height of the distillation tower depends on the height equivalent to a theoretical plate, HETP, and the equilibrium isotope separation factor, α H-T equi . The adsorption action improved not only HETP but also α H-T equi . Since the adsorption-distillation method proposed here can shorten the tower height with keeping advantages of the distillation, it may bring an excellent way for miniaturizing the distillation tower to detritiate a large amount of waste water from fusion reactors

  5. Temperature-based on-column solute focusing in capillary liquid chromatography reduces peak broadening from pre-column dispersion and volume overload when used alone or with solvent-based focusing.

    Science.gov (United States)

    Groskreutz, Stephen R; Horner, Anthony R; Weber, Stephen G

    2015-07-31

    On-column focusing is essential for satisfactory performance using capillary scale columns. On-column focusing results from generating transient conditions at the head of the column that lead to high solute retention. Solvent-based on-column focusing is a well-known approach to achieve this. Temperature-assisted on-column focusing (TASF) can also be effective. TASF improves focusing by cooling a short segment of the column inlet to a temperature that is lower than the column temperature during the injection and then rapidly heating the focusing segment to the match the column temperature. A troublesome feature of an earlier implementation of TASF was the need to leave the capillary column unpacked in that portion of the column inside the fitting connecting it to the injection valve. We have overcome that problem in this work by packing the head of the column with solid silica spheres. In addition, technical improvements to the TASF instrumentation include: selection of a more powerful thermo-electric cooler to create faster temperature changes and electronic control for easy incorporation into conventional capillary instruments. Used in conjunction with solvent-based focusing and with isocratic elution, volumes of paraben samples (esters of p-hydroxybenzoic acid) up to 4.5-times the column liquid volume can be injected without significant bandspreading due to volume overload. Interestingly, the shapes of the peaks from the lowest volume injections that we can make, 30nL, are improved when using TASF. TASF is very effective at reducing the detrimental effects of pre-column dispersion using isocratic elution. Finally, we show that TASF can be used to focus the neuropeptide galanin in a sample solvent with elution strength stronger than the mobile phase. Here, the stronger solvent is necessitated by the need to prevent peptide adsorption prior to and during analysis. Copyright © 2015 Elsevier B.V. All rights reserved.

  6. The effects of carbide column to swelling potential and Atterberg limit on expansive soil with column to soil drainage

    Science.gov (United States)

    Muamar Rifa'i, Alfian; Setiawan, Bambang; Djarwanti, Noegroho

    2017-12-01

    The expansive soil is soil that has a potential for swelling-shrinking due to changes in water content. Such behavior can exert enough force on building above to cause damage. The use of columns filled with additives such as Calcium Carbide is done to reduce the negative impact of expansive soil behavior. This study aims to determine the effect of carbide columns on expansive soil. Observations were made on swelling and spreading of carbides in the soil. 7 Carbide columns with 5 cm diameter and 20 cm height were installed into the soil with an inter-column spacing of 8.75 cm. Wetting is done through a pipe at the center of the carbide column for 20 days. Observations were conducted on expansive soil without carbide columns and expansive soil with carbide columns. The results showed that the addition of carbide column could reduce the percentage of swelling by 4.42%. Wetting through the center of the carbide column can help spread the carbide into the soil. The use of carbide columns can also decrease the rate of soil expansivity. After the addition of carbide column, the plasticity index value decreased from 71.76% to 4.3% and the shrinkage index decreased from 95.72% to 9.2%.

  7. Column Liquid Chromatography.

    Science.gov (United States)

    Majors, Ronald E.; And Others

    1984-01-01

    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,…

  8. Left ventricular dysfunction and blood glycohemoglobin levels in young diabetics

    Energy Technology Data Exchange (ETDEWEB)

    Aydiner, A.; Oto, A.; Oram, E.; Oram, A.; Ugurlu, S.; Karamehmetoglu, A. (Hacettepe Univ., Ankara (Turkey). Dept. of Cardiology); Aras, T.; Bekdik, C.F. (Hacettepe Univ., Ankara (Turkey). Dept. of Nuclear Medicine); Gedik, O. (Hacettepe Univ., Ankara (Turkey). Dept. of Endocrinology)

    1991-10-01

    Left ventricular function including regional wall motion (RWM) was evaluated by {sup 99m}Tc first-pass and equilibrium gated blood pool ventriculography and glycohemoglobin (HbA1c) blood levels determined by a quantitative column technique in 25 young patients with insulin-dependent diabetes mellitus without clinical evidence of heart diesease, and in healthy controls matched for age and sex. Phase analysis revealed abnormal RWM in 19 of 21 diabetic patients. The mean left ventricular global ejection fraction, the mean regional ejection fraction and the mean 1/3 filling fraction were lower and the time to peak ejection, the time to peak filling and the time to peak ejection/cardiac cycle were longer in diabetics than in controls. We found high HbA1c levels in all diabetics. There was no significant difference between patients with and without retinopathy and with and without peripheral neuropathy in terms of left ventricular function and HbA1c levels. (orig.).

  9. Left ventricular dysfunction and blood glycohemoglobin levels in young diabetics

    International Nuclear Information System (INIS)

    Aydiner, A.; Oto, A.; Oram, E.; Oram, A.; Ugurlu, S.; Karamehmetoglu, A.; Aras, T.; Bekdik, C.F.; Gedik, O.

    1991-01-01

    Left ventricular function including regional wall motion (RWM) was evaluated by 99m Tc first-pass and equilibrium gated blood pool ventriculography and glycohemoglobin (HbA1c) blood levels determined by a quantitative column technique in 25 young patients with insulin-dependent diabetes mellitus without clinical evidence of heart diesease, and in healthy controls matched for age and sex. Phase analysis revealed abnormal RWM in 19 of 21 diabetic patients. The mean left ventricular global ejection fraction, the mean regional ejection fraction and the mean 1/3 filling fraction were lower and the time to peak ejection, the time to peak filling and the time to peak ejection/cardiac cycle were longer in diabetics than in controls. We found high HbA1c levels in all diabetics. There was no significant difference between patients with and without retinopathy and with and without peripheral neuropathy in terms of left ventricular function and HbA1c levels. (orig.) [de

  10. Incidental retroaortic left innominate vein in adult patient

    Directory of Open Access Journals (Sweden)

    Alexandre Semionov, MD, PhD

    2017-09-01

    Full Text Available Retro-aortic left innominate vein is a rare vascular abnormality, usually associated with congenital heart disease. Here we report a case of isolated retro-aortic left innominate vein in an adult female.

  11. Modality-Based Organization of Ascending Somatosensory Axons in the Direct Dorsal Column Pathway

    Science.gov (United States)

    Niu, Jingwen; Ding, Long; Li, Jian J.; Kim, Hyukmin; Liu, Jiakun; Li, Haipeng; Moberly, Andrew; Badea, Tudor C.; Duncan, Ian D.; Son, Young-Jin; Scherer, Steven S.

    2013-01-01

    The long-standing doctrine regarding the functional organization of the direct dorsal column (DDC) pathway is the “somatotopic map” model, which suggests that somatosensory afferents are primarily organized by receptive field instead of modality. Using modality-specific genetic tracing, here we show that ascending mechanosensory and proprioceptive axons, two main types of the DDC afferents, are largely segregated into a medial–lateral pattern in the mouse dorsal column and medulla. In addition, we found that this modality-based organization is likely to be conserved in other mammalian species, including human. Furthermore, we identified key morphological differences between these two types of afferents, which explains how modality segregation is formed and why a rough “somatotopic map” was previously detected. Collectively, our results establish a new functional organization model for the mammalian direct dorsal column pathway and provide insight into how somatotopic and modality-based organization coexist in the central somatosensory pathway. PMID:24198362

  12. Phonological decisions require both the left and right supramarginal gyri

    DEFF Research Database (Denmark)

    Hartwigsen, Gesa; Baumgaertner, Annette; Price, Cathy J

    2010-01-01

    Recent functional imaging studies demonstrated that both the left and right supramarginal gyri (SMG) are activated when healthy right-handed subjects make phonological word decisions. However, lesion studies typically report difficulties with phonological processing after left rather than right...... the right or left SMG. Taken together, these findings provide converging evidence that the right SMG contributes to accurate and efficient phonological decisions in the healthy brain, with no evidence that the left and right SMG can compensate for one another during TMS. Our findings motivate detailed...... hemisphere damage. Here, we used a unique dual-site transcranial magnetic stimulation (TMS) approach to test whether the SMG in the right hemisphere contributes to modality-independent (i.e., auditory and visual) phonological decisions. To test task-specificity, we compared the effect of real or sham TMS...

  13. Tritium extraction from Pb-17Li by bubble columns

    International Nuclear Information System (INIS)

    Malara, C.

    1995-01-01

    Tritium extraction from the Pb-17Li liquid breeder of a fusion reactor can be efficiently carried out by bubble columns. To this aim, a mathematical model describing the complex fluid-dynamics of a bubble extractor is here presented. The model equations are made dimensionless and, together with the proper boundary conditions, numerically solved by the orthogonal collocation technique. Moreover, in order to better understand the role played by the different parameters in determining the performance of a bubble column, a closed solution of the model is obtained by introducing suitable hypotheses. A parametric analysis of the extraction efficiency of a bubble column as a function of the process parameters is carried out and, on this basis, the design of a tritium extraction system from the Pb-17Li breeder of a DEMO-type fusion reactor is proposed. 17 refs., 3 figs., 2 tabs

  14. Exploring the effect of mesopore size reduction on the column performance of silica-based open tubular capillary columns.

    Science.gov (United States)

    Hara, Takeshi; Futagami, Shunta; De Malsche, Wim; Baron, Gino V; Desmet, Gert

    2018-06-01

    We report on a modification in the hydrothermal treatment process of monolithic silica layers used in porous-layered open tubular (PLOT) columns. Lowering the temperature from the customary 95 °C to 80 °C, the size of the mesopores reduced by approximately about 35% from 12-13.5 nm to 7.5-9 nm, while the specific pore volume essentially remains unaltered. This led to an increase of the specific surface area (SA) of about 40%, quasi-independent of the porous layer thickness. The increased surface area provided a corresponding increase in retention, somewhat more (48%) than expected based on the increase in SA for the thin layer columns, and somewhat less than expected (34%) for the thick layer columns. The recipes were applied in 5 μm i.d.-capillaries with a length of 60 cm. Efficiencies under retained conditions amounted up to N = 137,000 for the PLOT column with a layer thickness (d f ) of 300 nm and to N = 109,000 for the PLOT column with d f  = 550 nm. Working under conditions of similar retention, the narrow pore/high SA columns produced with the new 80 °C recipe generated the same number of theoretical plates as the wide pore size/low SA columns produced with the 95 °C recipe. This shows the 80 °C-hydrothermal treatment process allows for an increase in the phase ratio of the PLOT columns without affecting their intrinsic mass transfer properties and separation kinetics. This is further corroborated by the fact that the plate height curves generated with the new and former recipe can both be well-fitted with the Golay-Aris equation without having to change the intra-layer diffusion coefficient. Copyright © 2018 Elsevier B.V. All rights reserved.

  15. Column-Oriented Database Systems (Tutorial)

    NARCIS (Netherlands)

    D. Abadi; P.A. Boncz (Peter); S. Harizopoulos

    2009-01-01

    textabstractColumn-oriented database systems (column-stores) have attracted a lot of attention in the past few years. Column-stores, in a nutshell, store each database table column separately, with attribute values belonging to the same column stored contiguously, compressed, and densely packed, as

  16. Quantum levitation by left-handed metamaterials

    Energy Technology Data Exchange (ETDEWEB)

    Leonhardt, Ulf; Philbin, Thomas G [School of Physics and Astronomy, University of St Andrews, North Haugh, St Andrews KY16 9SS (United Kingdom)

    2007-08-15

    Left-handed metamaterials make perfect lenses that image classical electromagnetic fields with significantly higher resolution than the diffraction limit. Here, we consider the quantum physics of such devices. We show that the Casimir force of two conducting plates may turn from attraction to repulsion if a perfect lens is sandwiched between them. For optical left-handed metamaterials, this repulsive force of the quantum vacuum may levitate ultra-thin mirrors.

  17. Quantum levitation by left-handed metamaterials

    International Nuclear Information System (INIS)

    Leonhardt, Ulf; Philbin, Thomas G

    2007-01-01

    Left-handed metamaterials make perfect lenses that image classical electromagnetic fields with significantly higher resolution than the diffraction limit. Here, we consider the quantum physics of such devices. We show that the Casimir force of two conducting plates may turn from attraction to repulsion if a perfect lens is sandwiched between them. For optical left-handed metamaterials, this repulsive force of the quantum vacuum may levitate ultra-thin mirrors

  18. Atomic column resolved electron energy-loss spectroscopy

    International Nuclear Information System (INIS)

    Duscher, G.; Pennycook, S.J.; Browning, N.D.

    1998-01-01

    Spatially resolved electron energy-loss spectroscopy (EELS) is rapidly developing into a unique and powerful tool to characterize internal interfaces. Because atomic column resolved Z-contrast imaging can be performed simultaneously with EELS in the scanning transmission electron microscope, this combination allows the atomic structure to be correlated with the electronic structure, and thus the local properties of interfaces or defects can be determined directly. However, the ability to characterize interfaces and defects at that level requires not only high spatial resolution but also the exact knowledge of the beam location, from where the spectrum is obtained. Here we discuss several examples progressing from cases where the limitation in spatial resolution is given by the microscopes or the nature of the sample, to one example of impurity atoms at a grain boundary, which show intensity and fine structure changes from atomic column to atomic column. Such data can be interpreted as changes in valence of the impurity, depending on its exact site in the boundary plane. Analysis ofthis nature is a valuable first step in understanding the microscopic structural, optical and electronic properties of materials. (orig.)

  19. Family of columns isospectral to gravity-loaded columns with tip force: A discrete approach

    Science.gov (United States)

    Ramachandran, Nirmal; Ganguli, Ranjan

    2018-06-01

    A discrete model is introduced to analyze transverse vibration of straight, clamped-free (CF) columns of variable cross-sectional geometry under the influence of gravity and a constant axial force at the tip. The discrete model is used to determine critical combinations of loading parameters - a gravity parameter and a tip force parameter - that cause onset of dynamic instability in the CF column. A methodology, based on matrix-factorization, is described to transform the discrete model into a family of models corresponding to weightless and unloaded clamped-free (WUCF) columns, each with a transverse vibration spectrum isospectral to the original model. Characteristics of models in this isospectral family are dependent on three transformation parameters. A procedure is discussed to convert the isospectral discrete model description into geometric description of realistic columns i.e. from the discrete model, we construct isospectral WUCF columns with rectangular cross-sections varying in width and depth. As part of numerical studies to demonstrate efficacy of techniques presented, frequency parameters of a uniform column and three types of tapered CF columns under different combinations of loading parameters are obtained from the discrete model. Critical combinations of these parameters for a typical tapered column are derived. These results match with published results. Example CF columns, under arbitrarily-chosen combinations of loading parameters are considered and for each combination, isospectral WUCF columns are constructed. Role of transformation parameters in determining characteristics of isospectral columns is discussed and optimum values are deduced. Natural frequencies of these WUCF columns computed using Finite Element Method (FEM) match well with those of the given gravity-loaded CF column with tip force, hence confirming isospectrality.

  20. Annular pulse column development studies

    International Nuclear Information System (INIS)

    Benedict, G.E.

    1980-01-01

    The capacity of critically safe cylindrical pulse columns limits the size of nuclear fuel solvent extraction plants because of the limited cross-sectional area of plutonium, U-235, or U-233 processing columns. Thus, there is a need to increase the cross-sectional area of these columns. This can be accomplished through the use of a column having an annular cross section. The preliminary testing of a pilot-plant-scale annular column has been completed and is reported herein. The column is made from 152.4-mm (6-in.) glass pipe sections with an 89-mm (3.5-in.) o.d. internal tube, giving an annular width of 32-mm (1.25-in.). Louver plates are used to swirl the column contents to prevent channeling of the phases. The data from this testing indicate that this approach can successfully provide larger-cross-section critically safe pulse columns. While the capacity is only 70% of that of a cylindrical column of similar cross section, the efficiency is almost identical to that of a cylindrical column. No evidence was seen of any non-uniform pulsing action from one side of the column to the other

  1. Interpretation of the lime column penetration test

    International Nuclear Information System (INIS)

    Liyanapathirana, D S; Kelly, R B

    2010-01-01

    Dry soil mix (DSM) columns are used to reduce the settlement and to improve the stability of embankments constructed on soft clays. During construction the shear strength of the columns needs to be confirmed for compliance with technical assumptions. A specialized blade shaped penetrometer known as the lime column probe, has been developed for testing DSM columns. This test can be carried out as a pull out resistance test (PORT) or a push in resistance test (PIRT). The test is considered to be more representative of average column shear strength than methods that test only a limited area of the column. Both PORT and PIRT tests require empirical correlations of measured resistance to an absolute measure of shear strength, in a similar manner to the cone penetration test. In this paper, finite element method is used to assess the probe factor, N, for the PORT test. Due to the large soil deformations around the probe, an Arbitrary Lagrangian Eulerian (ALE) based finite element formulation has been used. Variation of N with rigidity index and the friction at the probe-soil interface are investigated to establish a range for the probe factor.

  2. Investigating the Effect of Column Geometry on Separation Efficiency using 3D Printed Liquid Chromatographic Columns Containing Polymer Monolithic Phases.

    Science.gov (United States)

    Gupta, Vipul; Beirne, Stephen; Nesterenko, Pavel N; Paull, Brett

    2018-01-16

    Effect of column geometry on the liquid chromatographic separations using 3D printed liquid chromatographic columns with in-column polymerized monoliths has been studied. Three different liquid chromatographic columns were designed and 3D printed in titanium as 2D serpentine, 3D spiral, and 3D serpentine columns, of equal length and i.d. Successful in-column thermal polymerization of mechanically stable poly(BuMA-co-EDMA) monoliths was achieved within each design without any significant structural differences between phases. Van Deemter plots indicated higher efficiencies for the 3D serpentine chromatographic columns with higher aspect ratio turns at higher linear velocities and smaller analysis times as compared to their counterpart columns with lower aspect ratio turns. Computational fluid dynamic simulations of a basic monolithic structure indicated 44%, 90%, 100%, and 118% higher flow through narrow channels in the curved monolithic configuration as compared to the straight monolithic configuration at linear velocities of 1, 2.5, 5, and 10 mm s -1 , respectively. Isocratic RPLC separations with the 3D serpentine column resulted in an average 23% and 245% (8 solutes) increase in the number of theoretical plates as compared to the 3D spiral and 2D serpentine columns, respectively. Gradient RPLC separations with the 3D serpentine column resulted in an average 15% and 82% (8 solutes) increase in the peak capacity as compared to the 3D spiral and 2D serpentine columns, respectively. Use of the 3D serpentine column at a higher flow rate, as compared to the 3D spiral column, provided a 58% reduction in the analysis time and 74% increase in the peak capacity for the isocratic separations of the small molecules and the gradient separations of proteins, respectively.

  3. Column-Oriented Database Systems (Tutorial)

    OpenAIRE

    Abadi, D.; Boncz, Peter; Harizopoulos, S.

    2009-01-01

    textabstractColumn-oriented database systems (column-stores) have attracted a lot of attention in the past few years. Column-stores, in a nutshell, store each database table column separately, with attribute values belonging to the same column stored contiguously, compressed, and densely packed, as opposed to traditional database systems that store entire records (rows) one after the other. Reading a subset of a table’s columns becomes faster, at the potential expense of excessive disk-head s...

  4. Mining Genome-Scale Growth Phenotype Data through Constant-Column Biclustering

    KAUST Repository

    Alzahrani, Majed A.

    2017-01-01

    for mining in growth phenotype data. Here, we propose Gracob, a novel, efficient graph-based method that casts and solves the constant-column biclustering problem as a maximal clique finding problem in a multipartite graph. We compared Gracob with a large

  5. Nuclear reactor control column

    International Nuclear Information System (INIS)

    Bachovchin, D.M.

    1982-01-01

    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 crosssectional 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

  6. Concrete loading column for Maureen field built at Loch Kishorn

    Energy Technology Data Exchange (ETDEWEB)

    1982-09-01

    The first concrete-built loading column for a North Sea oilfield left the Kyle of Lochalsh under tow on August 18, bound for the Phillips Petroleum Group's Maureen field 163 miles (262 km) eastnortheast of Aberdeen. The 10,000 tonne gravity structure is 430ft (131m) tall and will have cost pounds29 million by the time it is installed offshore. Before starting its 20-day tow behind the tug ''Les Abeilles'', the offshore tankerloading column recently underwent the complex final stages in its construction, involving tow-out from drydock of two concrete sections, their joining by an articulated or hinged joint and then the structure's uprighting in deep water for the fitting of a rotating steel head. The concrete articulated loading column is one of several innovations in the Maureen development programme. The operator, Phillips Petroleum United Kingdom Ltd., and its co-venturers considered that some new approaches were necessary in view of the relatively small size of Maureen's recoverable oil reserves and hence the field's marginal development economics. These innovations included drilling the development wells by semisubmersible drilling rig through a subsea template while the production platform is being built on shore (with a fully completed deck section). Production will commence as soon as the wells are tied back from the subsea template to the platform.

  7. Left-main restenosis in the DES era-a call for action.

    Science.gov (United States)

    di Palma, Gaetano; Cortese, Bernardo

    2017-11-10

    Percutaneous treatment of the unprotected left main trunk (ULM), defined as a vessel without patent bypass graft either to the left circumflex (LCX) or left anterior descending (LAD) artery, has gained a precise role thanks to recent scientific evidence. Although new generation drug-eluting stents have already proven to be safer, there is still a consistent risk of restenosis and late adverse events. The optimal management of a ULM restenosis is still debated. Here we aim at presenting a review of the available data in literature and show our choice for treating it. Copyright © 2017 Elsevier Inc. All rights reserved.

  8. End shape effects on the mθ=1 diocotron instability in hollow electron columns

    International Nuclear Information System (INIS)

    Kabantsev, A. A.; Driscoll, C. F.

    1999-01-01

    Magnetically confined hollow columns of electrons exhibit a robust exponential m θ =1 diocotron instability, whereas standard 2-D fluid theory predicts at most algebraic growth. This discrepancy suggests that experimental subtleties such as finite axial length of the plasma column must be considered. Here, we present a systematic analysis of our experiments to determine the detailed influence of the plasma end curvature on the observed diocotron instability. Observed dependencies of unstable mode frequency, growth rate and spatial eigenfunction as a function of the plasma end curvature are in quantitative (factor-of-two) agreement with recent quasi-2D extension of the fluid theory

  9. Column Selection for Biomedical Analysis Supported by Column Classification Based on Four Test Parameters.

    Science.gov (United States)

    Plenis, Alina; Rekowska, Natalia; Bączek, Tomasz

    2016-01-21

    This article focuses on correlating the column classification obtained from the method created at the Katholieke Universiteit Leuven (KUL), with the chromatographic resolution attained in biomedical separation. In the KUL system, each column is described with four parameters, which enables estimation of the FKUL value characterising similarity of those parameters to the selected reference stationary phase. Thus, a ranking list based on the FKUL value can be calculated for the chosen reference column, then correlated with the results of the column performance test. In this study, the column performance test was based on analysis of moclobemide and its two metabolites in human plasma by liquid chromatography (LC), using 18 columns. The comparative study was performed using traditional correlation of the FKUL values with the retention parameters of the analytes describing the column performance test. In order to deepen the comparative assessment of both data sets, factor analysis (FA) was also used. The obtained results indicated that the stationary phase classes, closely related according to the KUL method, yielded comparable separation for the target substances. Therefore, the column ranking system based on the FKUL-values could be considered supportive in the choice of the appropriate column for biomedical analysis.

  10. Improvements in solvent extraction columns

    International Nuclear Information System (INIS)

    Aughwane, K.R.

    1987-01-01

    Solvent extraction columns are used in the reprocessing of irradiated nuclear fuel. For an effective reprocessing operation a solvent extraction column is required which is capable of distributing the feed over most of the column. The patent describes improvements in solvent extractions columns which allows the feed to be distributed over an increased length of column than was previously possible. (U.K.)

  11. ( Anogeissus leiocarpus ) timber columns

    African Journals Online (AJOL)

    A procedure for designing axially loaded Ayin (Anogeissus leiocarpus) wood column or strut has been investigated. Instead of the usual categorization of columns into short, intermediate and slender according to the value of slenderness ratio, a continuous column formula representing the three categories was derived.

  12. LIQUID-LIQUID EXTRACTION COLUMNS

    Science.gov (United States)

    Thornton, J.D.

    1957-12-31

    This patent relates to liquid-liquid extraction columns having a means for pulsing the liquid in the column to give it an oscillatory up and down movement, and consists of a packed column, an inlet pipe for the dispersed liquid phase and an outlet pipe for the continuous liquid phase located in the direct communication with the liquid in the lower part of said column, an inlet pipe for the continuous liquid phase and an outlet pipe for the dispersed liquid phase located in direct communication with the liquid in the upper part of said column, a tube having one end communicating with liquid in the lower part of said column and having its upper end located above the level of said outlet pipe for the dispersed phase, and a piston and cylinder connected to the upper end of said tube for applying a pulsating pneumatic pressure to the surface of the liquid in said tube so that said surface rises and falls in said tube.

  13. Modalization in the Political Column of Tempo Magazine

    OpenAIRE

    Rahmah, Maria Betti Sinaga and

    2017-01-01

    The study focuses on analyzing the use of modalization in the Political Column of Tempo Magazine. The objectives were to find out the type of modalization and to describe the use of modalization in the Political Column of Tempo magazine. The data were taken from Political Column of Tempo magazine published in June and July 2017. The source of data was Political Column in Tempo magazine. The data analysis applied descriptive qualitative research. There were 135 clauses which contained Modaliza...

  14. Estimations of temperature deviations in chromatographic columns using isenthalpic plots. I. Theory for isocratic systems.

    Science.gov (United States)

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

    2014-10-31

    We propose to use constant enthalpy or isenthalpic diagrams as a tool to estimate the extent of the temperature variations caused by the mobile phase pressure drop along a chromatographic column, e.g. of its cooling in supercritical fluid and its heating in ultra-performance liquid chromatography. Temperature strongly affects chromatographic phenomena. Any of its variations inside the column, whether intended or not, can lead to significant changes in separation performance. Although instruments use column ovens in order to keep constant the column temperature, operating conditions leading to a high pressure drop may cause significant variations of the column temperature, both in the axial and the radial directions, from the set value. Different ways of measuring these temperature variations are available but they are too inconvenient to be employed in many practical situations. In contrast, the thermodynamic plot-based method that we describe here can easily be used with only a ruler and a pencil. They should be helpful in developing methods or in analyzing results in analytical laboratories. Although the most effective application area for this approach should be SFC (supercritical fluid chromatography), it can be applied to any chromatographic conditions in which temperature variations take place along the column due to the pressure drop, e.g. in ultra-high pressure liquid chromatography (UHPLC). The method proposed here is applicable to isocractic conditions only. Copyright © 2014 Elsevier B.V. All rights reserved.

  15. Scalability of pre-packed preparative chromatography columns with different diameters and lengths taking into account extra column effects.

    Science.gov (United States)

    Schweiger, Susanne; Jungbauer, Alois

    2018-02-16

    Small pre-packed columns are commonly used to estimate the optimum run parameters for pilot and production scale. The question arises if the experiments obtained with these columns are scalable, because there are substantial changes in extra column volume when going from a very small scale to a benchtop column. In this study we demonstrate the scalability of pre-packed disposable and non-disposable columns of volumes in the range of 0.2-20 ml packed with various media using superficial velocities in the range of 30-500 cm/h. We found that the relative contribution of extra column band broadening to total band broadening was not only high for columns with small diameters, but also for columns with a larger volume due to their wider diameter. The extra column band broadening can be more than 50% for columns with volumes larger than 10 ml. An increase in column diameter leads to high additional extra column band broadening in the filter, frits, and adapters of the columns. We found a linear relationship between intra column band broadening and column length, which increased stepwise with increases in column diameter. This effect was also corroborated by CFD simulation. The intra column band broadening was the same for columns packed with different media. An empirical engineering equation and the data gained from the extra column effects allowed us to predict the intra, extra, and total column band broadening just from column length, diameter, and flow rate. Copyright © 2018 The Author(s). Published by Elsevier B.V. All rights reserved.

  16. Micro-fabricated semi-packed column for gas chromatography by using functionalized parylene as a stationary phase

    International Nuclear Information System (INIS)

    Nakai, T; Nishiyama, S; Shuzo, M; Delaunay, J-J; Yamada, I

    2009-01-01

    The conformal coating of effective stationary phases onto micro-fabricated columns having complex geometries such as semi-packed columns poses a real challenge. Here, we report for the first time the conformal coating of a semi-packed column with amino-functionalized parylene diX-AM (poly-aminomethyl-[2,2]-paracyclophane), which was found to be an effective stationary-phase material for the chromatography of short-retention-time compounds. A semi-packed column (consisting of a zigzag array of 30 µm square micro-pillars in a 1.0 m long, 180 µm wide and 230 µm deep channel) and an open tubular column (1.0 m long, 160 µm wide and 230 µm deep channel) used for comparison purposes were micro-fabricated on silicon that was subsequently coated with diX-AM parylene and thermally bonded. The chromatograms recorded on a commercial gas chromatograph demonstrated the usefulness of the conformal diX-AM coating as a stationary phase for semi-packed columns. The separation efficiency of the semi-packed column was found to be more than ten times that of the open tubular column

  17. Optimization and simulation of tandem column supercritical fluid chromatography separations using column back pressure as a unique parameter.

    Science.gov (United States)

    Wang, Chunlei; Tymiak, Adrienne A; Zhang, Yingru

    2014-04-15

    Tandem column supercritical fluid chromatography (SFC) has demonstrated to be a useful technique to resolve complex mixtures by serially coupling two columns of different selectivity. The overall selectivity of a tandem column separation is the retention time weighted average of selectivity from each coupled column. Currently, the method development merely relies on extensive screenings and is often a hit-or-miss process. No attention is paid to independently adjust retention and selectivity contributions from individual columns. In this study, we show how tandem column SFC selectivity can be optimized by changing relative dimensions (length or inner diameter) of the coupled columns. Moreover, we apply column back pressure as a unique parameter for SFC optimization. Continuous tuning of tandem column SFC selectivity is illustrated through column back pressure adjustments of the upstream column, for the first time. In addition, we show how and why changing coupling order of the columns can produce dramatically different separations. Using the empirical mathematical equation derived in our previous study, we also demonstrate a simulation of tandem column separations based on a single retention time measurement on each column. The simulation compares well with experimental results and correctly predicts column order and back pressure effects on the separations. Finally, considerations on instrument and column hardware requirements are discussed.

  18. The design of a new concept chromatography column.

    Science.gov (United States)

    Camenzuli, Michelle; Ritchie, Harald J; Ladine, James R; Shalliker, R Andrew

    2011-12-21

    Active Flow Management is a new separation technique whereby the flow of mobile phase and the injection of sample are introduced to the column in a manner that allows migration according to the principles of the infinite diameter column. A segmented flow outlet fitting allows for the separation of solvent or solute that elutes along the central radial section of the column from that of the sample or solvent that elutes along the wall region of the column. Separation efficiency on the analytical scale is increased by 25% with an increase in sensitivity by as much as 52% compared to conventional separations.

  19. Green rust formation controls nutrient availability in a ferruginous water column

    DEFF Research Database (Denmark)

    Zegeye, Asfaw; Bonneville, Steeve; Benning, Liane G.

    2013-01-01

    a mechanism for reconstructing ancient ocean chemistry. Such reconstructions depend, however, on precise knowledge of the iron minerals formed in the water column. Here, we combine mineralogical and geochemical analyses to demonstrate formation of the mixed-valence iron mineral, green rust, in ferruginous...

  20. Gas Chromatograph Method Optimization Trade Study for RESOLVE: 20-meter Column v. 8-meter Column

    Science.gov (United States)

    Huz, Kateryna

    2014-01-01

    RESOLVE is the payload on a Class D mission, Resource Prospector, which will prospect for water and other volatile resources at a lunar pole. The RESOLVE payload's primary scientific purpose includes determining the presence of water on the moon in the lunar regolith. In order to detect the water, a gas chromatograph (GC) will be used in conjunction with a mass spectrometer (MS). The goal of the experiment was to compare two GC column lengths and recommend which would be best for RESOLVE's purposes. Throughout the experiment, an Inficon Fusion GC and an Inficon Micro GC 3000 were used. The Fusion had a 20m long column with 0.25mm internal diameter (Id). The Micro GC 3000 had an 8m long column with a 0.32mm Id. By varying the column temperature and column pressure while holding all other parameters constant, the ideal conditions for testing with each column length in their individual instrument configurations were determined. The criteria used for determining the optimal method parameters included (in no particular order) (1) quickest run time, (2) peak sharpness, and (3) peak separation. After testing numerous combinations of temperature and pressure, the parameters for each column length that resulted in the most optimal data given my three criteria were selected. The ideal temperature and pressure for the 20m column were 95 C and 50psig. At this temperature and pressure, the peaks were separated and the retention times were shorter compared to other combinations. The Inficon Micro GC 3000 operated better at lower temperature mainly due to the shorter 8m column. The optimal column temperature and pressure were 70 C and 30psig. The Inficon Micro GC 3000 8m column had worse separation than the Inficon Fusion 20m column, but was able to separate water within a shorter run time. Therefore, the most significant tradeoff between the two column lengths was peak separation of the sample versus run time. After performing several tests, it was concluded that better

  1. Mass transfer model liquid phase catalytic exchange column simulation applicable to any column composition profile

    Energy Technology Data Exchange (ETDEWEB)

    Busigin, A. [NITEK USA Inc., Ocala, FL (United States)

    2015-03-15

    Liquid Phase Catalytic Exchange (LPCE) is a key technology used in water detritiation systems. Rigorous simulation of LPCE is complicated when a column may have both hydrogen and deuterium present in significant concentrations in different sections of the column. This paper presents a general mass transfer model for a homogenous packed bed LPCE column as a set of differential equations describing composition change, and equilibrium equations to define the mass transfer driving force within the column. The model is used to show the effect of deuterium buildup in the bottom of an LPCE column from non-negligible D atom fraction in the bottom feed gas to the column. These types of calculations are important in the design of CECE (Combined Electrolysis and Catalytic Exchange) water detritiation systems.

  2. The instability analysis of the cryogenic distillation column condenser

    International Nuclear Information System (INIS)

    David, Claudia; Stefanescu, Ioan; Vasut, Felicia; Preda, Anisoara; Ghitulescu, Alina

    2008-01-01

    Full text: The column plays the main part of the process in a distillation plant for hydrogen isotopes. The variable parameters like vaporizer power or liquid hydrogen level fluctuation can induce non-steady states which lead to performance decrease of the process. In the paper the liquid hydrogen fluctuation from the cryogenic column condenser is taken into account. This fluctuation determines the variation of the gas holdup from the top of the column. It was considered a column equipped with order package, NT theoretical plates, H height and fed with a deuterium-tritium mixture. A mathematical model was developed based on the balance equations in the column, on every plate and in the condenser. As fluctuation of the level in the condenser a sinusoidal function was considered. The program developed was used for some cases with input data variables like: initial concentration of tritium in the mixture, the amplitude and period of the sinusoidal function. It was calculated the height of the transfer unit as the ratio of the column height to the Fenske number and it was determined the time for entrance in steady state. The results were presented in a master table. There were given also diagrams. There were analyzed the results. (authors)

  3. Small Column Ion Exchange

    International Nuclear Information System (INIS)

    Huff, Thomas

    2010-01-01

    Small Column Ion Exchange (SCIX) leverages a suite of technologies developed by DOE across the complex to achieve lifecycle savings. Technologies are applicable to multiple sites. Early testing supported multiple sites. Balance of SRS SCIX testing supports SRS deployment. A forma Systems Engineering Evaluation (SEE) was performed and selected Small Column Ion Exchange columns containing Crystalline Silicotitanate (CST) in a 2-column lead/lag configuration. SEE considered use of Spherical Resorcinol-Formaldehyde (sRF). Advantages of approach at SRS include: (1) no new buildings, (2) low volume of Cs waste in solid form compared to aqueous strip effluent; and availability of downstream processing facilities for immediate processing of spent resin.

  4. The general packed column : an analytical solution

    NARCIS (Netherlands)

    Gielen, J.L.W.

    2000-01-01

    The transient behaviour of a packed column is considered. The column, uniformly packed on a macroscopic scale, is multi-structured on the microscopic level: the solid phase consists of particles, which may differ in incidence, shape or size, and other relevant physical properties. Transport in the

  5. Calcium Isotope Analysis with "Peak Cut" Method on Column Chemistry

    Science.gov (United States)

    Zhu, H.; Zhang, Z.; Liu, F.; Li, X.

    2017-12-01

    To eliminate isobaric interferences from elemental and molecular isobars (e.g., 40K+, 48Ti+, 88Sr2+, 24Mg16O+, 27Al16O+) on Ca isotopes during mass determination, samples should be purified through ion-exchange column chemistry before analysis. However, large Ca isotopic fractionation has been observed during column chemistry (Russell and Papanastassiou, 1978; Zhu et al., 2016). Therefore, full recovery during column chemistry is greatly needed, otherwise uncertainties would be caused by poor recovery (Zhu et al., 2016). Generally, matrix effects could be enhanced by full recovery, as other elements might overlap with Ca cut during column chemistry. Matrix effects and full recovery are difficult to balance and both need to be considered for high-precision analysis of stable Ca isotopes. Here, we investigate the influence of poor recovery on δ44/40Ca using TIMS with the double spike technique. The δ44/40Ca values of IAPSO seawater, ML3B-G and BHVO-2 in different Ca subcats (e.g., 0-20, 20-40, 40-60, 60-80, 80-100%) with 20% Ca recovery on column chemistry display limited variation after correction by the 42Ca-43Ca double spike technique with the exponential law. Notably, δ44/40Ca of each Ca subcut is quite consistent with δ44/40Ca of Ca cut with full recovery within error. Our results indicate that the 42Ca-43Ca double spike technique can simultaneously correct both of the Ca isotopic fractionation that occurred during column chemistry and thermal ionization mass spectrometry (TIMS) determination properly, because both of the isotopic fractionation occurred during analysis follow the exponential law well. Therefore, we propose the "peak cut" method on Ca column chemistry for samples with complex matrix effects. Briefly, for samples with low Ca contents, we can add the double spike before column chemistry, and only collect the middle of the Ca eluate and abandon the both sides of Ca eluate that might overlap with other elements (e.g., K, Sr). This method would

  6. Two generalizations of column-convex polygons

    International Nuclear Information System (INIS)

    Feretic, Svjetlan; Guttmann, Anthony J

    2009-01-01

    Column-convex polygons were first counted by area several decades ago, and the result was found to be a simple, rational, generating function. In this work we generalize that result. Let a p-column polyomino be a polyomino whose columns can have 1, 2, ..., p connected components. Then column-convex polygons are equivalent to 1-convex polyominoes. The area generating function of even the simplest generalization, namely 2-column polyominoes, is unlikely to be solvable. We therefore define two classes of polyominoes which interpolate between column-convex polygons and 2-column polyominoes. We derive the area generating functions of those two classes, using extensions of existing algorithms. The growth constants of both classes are greater than the growth constant of column-convex polyominoes. Rather tight lower bounds on the growth constants complement a comprehensive asymptotic analysis.

  7. Flooding characteristics of pulsed-sieve plate column. Contributed Paper ED-09

    International Nuclear Information System (INIS)

    Vishnu Anand, P.; Pandey, N.K.; Rajeev, R.; Joyakin, C.V.; Kamachi Mudali, U.; Natarajan, R.

    2014-01-01

    Successful design of a pulsed sieve plate extraction column relies on profound understanding of its hydrodynamic and mass transfer characteristics. Present work outlines a comprehensive study of flooding velocity, a hydrodynamic parameter, as a function of various operating conditions of the column. Experimental studies were carried out using water-normal paraffin hydrocarbon system, under no mass transfer condition, in a pilot plant pulsed sieve plate column equipped with standard plate cartridges. Flooding velocity is characterized here as a function of phase flow ratio and pulse velocity with the aid of characteristic velocity concept together with an exponential function. Flooding points were experimentally identified with satisfactory accuracy using a quantitative method and dispersed phase hold-up was measured by online sampling. To verify the extent of applicability of some of the reported generalized flooding correlations from a design perspective, an analysis was done using our precisely generated experimental flooding data. (author)

  8. Posterior column reconstruction improves fusion rates at the level of osteotomy in three-column posterior-based osteotomies.

    Science.gov (United States)

    Lewis, Stephen J; Mohanty, Chandan; Gazendam, Aaron M; Kato, So; Keshen, Sam G; Lewis, Noah D; Magana, Sofia P; Perlmutter, David; Cape, Jennifer

    2018-03-01

    To determine the incidence of pseudarthrosis at the osteotomy site after three-column spinal osteotomies (3-COs) with posterior column reconstruction. 82 consecutive adult 3-COs (66 patients) with a minimum of 2-year follow-up were retrospectively reviewed. All cases underwent posterior 3-COs with two-rod constructs. The inferior facets of the proximal level were reduced to the superior facets of the distal level. If that was not possible, a structural piece of bone graft either from the local resection or a local rib was slotted in the posterior column defect to re-establish continual structural posterior bone across the lateral margins of the resection. No interbody cages were used at the level of the osteotomy. There were 34 thoracic osteotomies, 47 lumbar osteotomies and one sacral osteotomy with a mean follow-up of 52 (24-126) months. All cases underwent posterior column reconstructions described above and the addition of interbody support or additional posterior rods was not performed for fusion at the osteotomy level. Among them, 29 patients underwent one or more revision surgeries. There were three definite cases of pseudarthrosis at the osteotomy site (4%). Six revisions were also performed for pseudarthrosis at other levels. Restoration of the structural integrity of the posterior column in three-column posterior-based osteotomies was associated with > 95% fusion rate at the level of the osteotomy. Pseudarthrosis at other levels was the second most common reason for revision following adjacent segment disease in the long-term follow-up.

  9. A spin column-free approach to sodium hydroxide-based glycan permethylation.

    Science.gov (United States)

    Hu, Yueming; Borges, Chad R

    2017-07-24

    Glycan permethylation was introduced as a tool to facilitate the study of glycans in 1903. Since that time, permethylation procedures have been continually modified to improve permethylation efficiency and qualitative applicability. Typically, however, either laborious preparation steps or cumbersome and uneconomical spin columns have been needed to obtain decent permethylation yields on small glycan samples. Here we describe a spin column-free (SCF) glycan permethylation procedure that is applicable to both O- and N-linked glycans and can be employed upstream to intact glycan analysis by MALDI-MS, ESI-MS, or glycan linkage analysis by GC-MS. The SCF procedure involves neutralization of NaOH beads by acidified phosphate buffer, which eliminates the risk of glycan oxidative degradation and avoids the use of spin columns. Optimization of the new permethylation procedure provided high permethylation efficiency for both hexose (>98%) and HexNAc (>99%) residues-yields which were comparable to (or better than) those of some widely-used spin column-based procedures. A light vs. heavy labelling approach was employed to compare intact glycan yields from a popular spin-column based approach to the SCF approach. Recovery of intact N-glycans was significantly better with the SCF procedure (p 0.75; p < 0.01). In summary, the SCF permethylation procedure expedites and economizes both intact glycan analysis and linkage analysis of glycans from whole biospecimens.

  10. A spin column-free approach to sodium hydroxide-based glycan permethylation†

    Science.gov (United States)

    Hu, Yueming; Borges, Chad R.

    2018-01-01

    Glycan permethylation was introduced as a tool to facilitate the study of glycans in 1903. Since that time, permethylation procedures have been continually modified to improve permethylation efficiency and qualitative applicability. Typically, however, either laborious preparation steps or cumbersome and uneconomical spin columns have been needed to obtain decent permethylation yields on small glycan samples. Here we describe a spin column-free (SCF) glycan permethylation procedure that is applicable to both O- and N-linked glycans and can be employed upstream to intact glycan analysis by MALDI-MS, ESI-MS, or glycan linkage analysis by GC-MS. The SCF procedure involves neutralization of NaOH beads by acidified phosphate buffer, which eliminates the risk of glycan oxidative degradation and avoids the use of spin columns. Optimization of the new permethylation procedure provided high permethylation efficiency for both hexose (>98%) and HexNAc (>99%) residues—yields which were comparable to (or better than) those of some widely-used spin column-based procedures. A light vs. heavy labelling approach was employed to compare intact glycan yields from a popular spin-column based approach to the SCF approach. Recovery of intact N-glycans was significantly better with the SCF procedure (p 0.75; p < 0.01). In summary, the SCF permethylation procedure expedites and economizes both intact glycan analysis and linkage analysis of glycans from whole biospecimens. PMID:28635997

  11. The central column structure in SPHEX

    International Nuclear Information System (INIS)

    Duck, R.C.; French, P.A.; Browning, P.K.; Cunningham, G.; Gee, S.J.; al-Karkhy, A.; Martin, R.; Rusbridge, M.G.

    1994-01-01

    SPHEX is a gun injected spheromak in which a magnetised Marshall gun generates and maintains an approximately axisymmetric toroidal plasma within a topologically spherical flux conserving vessel. The central column has been defined as a region of high mean floating potential, f > up to ∼ 150 V, aligned with the geometric axis of the device. It has been suggested that this region corresponds to the open magnetic flux which is connected directly to the central electrode of the gun and links the toroidal annulus (in which f > ∼ 0 V). Poynting vector measurements have shown that the power required to drive toroidal current in the annulus is transmitted out of the column by the coherent 20 kHz mode which pervades the plasma. Measurements of the MHD dynamo in the column indicate an 'antidynamo' electric field due to correlated fluctuations in v and B at the 20 kHz mode frequency which is consistent with the time-averaged Ohm's Law. On shorting the gun electrodes, the density in the column region decays rapidly leaving a 'hole' of radius R c ∼ 7 cm. This agrees with the estimated dimension of the open flux from mean internal B measurements and axisymmetric force-free equilibrium modelling, but is considerably smaller than the radius of ∼ 13 cm inferred from the time-averaged potential. In standard operating conditions the gun delivers a current of I G ∼ 60 kA at V G ∼ 500 V for ∼ 1 ms, driving a toroidal current of I t ∼ 60 kA. Ultimately we wish to understand the mechanism which drives toroidal current in the annulus; the central column is of interest because of the crucial role it plays in this process. (author) 8 refs., 6 figs

  12. What's Left of the Left-Right Dimension? Why the Economic Policy Positions of Europeans Do Not Fit the Left-Right Dimension.

    Science.gov (United States)

    Otjes, Simon

    2018-01-01

    In political science the economic left-right dimension plays a central role. A growing body of evidence shows that the economic policy preferences of a large segment of citizens do not scale sufficiently. Using Mokken scale analysis, this study determines the causes of this phenomenon. Differences in the extent to which the economic policy preferences of citizens fit the left-right dimension can be explained in terms of the interaction between individual level and political system-level variables: citizens who spend more attention to politicians with views that conform to the left-right dimension, have views that conform to the left-right dimension. There is also a role for the legacy of communist dictatorship: citizens who were socialised in democratic countries have views that fit the left-right dimension better than those socialised during communism.

  13. Comparative study of the performance of columns packed with several new fine silica particles. Would the external roughness of the particles affect column properties?

    Science.gov (United States)

    Gritti, Fabrice; Guiochon, Georges

    2007-09-28

    We measured and compared the characteristics and performance of columns packed with particles of five different C(18)-bonded silica, 3 and 5 microm Luna, 3 microm Atlantis, 3.5 microm Zorbax, and 2.7 microm Halo. The average particle size of each material was derived from the SEM pictures of 200 individual particles. These pictures contrast the irregular morphology of the external surface of the Zorbax and Halo particles and the smooth surface of the Luna and Atlantis particles. In a wide range of mobile phase velocities (from 0.010 to 3 mL/min) and at ambient temperature, we measured the first and second central moments of the peaks of naphthalene, insulin, and bovine serum albumin (BSA). These moments were corrected for the contributions of the extra-column volumes to calculate the reduced HETPs. The C-terms of naphthalene and insulin are largest for the Halo and Zorbax materials and the A-term smallest for the Halo-packed column. The Halo column performs the best for the low molecular weight compound naphthalene (minimum reduced HETP, 1.4) but is not as good as the Atlantis or Luna columns for the large molecular weight compound insulin. The Zorbax column is the least efficient column because of its large C-term. The lowest sample diffusivity through these particles, alone, does not account for the results. It is most likely that the roughness of the external surface of the Halo and Zorbax particles limit the performance of these columns at high flow rates generating an unusually high film mass transfer resistance.

  14. Development of spent salt treatment technology by zeolite column system. Performance evaluation of zeolite column

    International Nuclear Information System (INIS)

    Miura, Hidenori; Uozumi, Koichi

    2009-01-01

    At electrorefining process, fission products(FPs) accumulate in molten salt. To avoid influence on heating control by decay heat and enlargement of FP amount in the recovered fuel, FP elements must be removed from the spent salt of the electrorefining process. For the removal of the FPs from the spent salt, we are investigating the availability of zeolite column system. For obtaining the basic data of the column system, such as flow property and ion-exchange performance while high temperature molten salt is passing through the column, and experimental apparatus equipped with fraction collector was developed. By using this apparatus, following results were obtained. 1) We cleared up the flow parameter of column system with zeolite powder, such as flow rate control by argon pressure. 2) Zeolite 4A in the column can absorb cesium that is one of the FP elements in molten salt. From these results, we got perspective on availability of the zeolite column system. (author)

  15. Effect of pre- and post-column band broadening on the performance of high-speed chromatography columns under isocratic and gradient conditions.

    Science.gov (United States)

    Vanderlinden, Kim; Broeckhoven, Ken; Vanderheyden, Yoachim; Desmet, Gert

    2016-04-15

    We report on the results of an experimental and theoretical study of the effect of the extra-column band broadening (ECBB) on the performance of narrow-bore columns filled with the smallest particles that are currently commercially available. Emphasis is on the difference between the effect of ECBB under gradient and isocratic conditions, as well as on the ability to model and predict the ECBB effects using well-established band broadening expressions available from the theory of chromatography. The fine details and assumptions that need to be taken into account when using these expressions are discussed. The experiments showed that, the steeper the gradient, the more pronounced the extra-column band broadening losses become. Whereas the pre-column band broadening can in both isocratic and gradient elution be avoided by playing on the possibilities to focus the analytes on top of the column (e.g. by using the POISe injection method when running isocratic separations), the post-column extra-column band broadening is inescapable in both cases. Inducing extra-column band broadening by changing the inner diameter of the post-column tubing from 65 to 250 μm, we found that all peaks in the chromatogram are strongly affected (around a factor of 1.9 increase in relative peak width) when running steep gradients, while usually only the first eluting peak was affected in the isocratic mode or when running shallow gradients (factor 1.6-1.8 increase in relative peak width for the first eluting analyte). Copyright © 2016 Elsevier B.V. All rights reserved.

  16. Automated Hydrophobic Interaction Chromatography Column Selection for Use in Protein Purification

    Science.gov (United States)

    Murphy, Patrick J. M.; Stone, Orrin J.; Anderson, Michelle E.

    2011-01-01

    In contrast to other chromatographic methods for purifying proteins (e.g. gel filtration, affinity, and ion exchange), hydrophobic interaction chromatography (HIC) commonly requires experimental determination (referred to as screening or "scouting") in order to select the most suitable chromatographic medium for purifying a given protein 1. The method presented here describes an automated approach to scouting for an optimal HIC media to be used in protein purification. HIC separates proteins and other biomolecules from a crude lysate based on differences in hydrophobicity. Similar to affinity chromatography (AC) and ion exchange chromatography (IEX), HIC is capable of concentrating the protein of interest as it progresses through the chromatographic process. Proteins best suited for purification by HIC include those with hydrophobic surface regions and able to withstand exposure to salt concentrations in excess of 2 M ammonium sulfate ((NH4)2SO4). HIC is often chosen as a purification method for proteins lacking an affinity tag, and thus unsuitable for AC, and when IEX fails to provide adequate purification. Hydrophobic moieties on the protein surface temporarily bind to a nonpolar ligand coupled to an inert, immobile matrix. The interaction between protein and ligand are highly dependent on the salt concentration of the buffer flowing through the chromatography column, with high ionic concentrations strengthening the protein-ligand interaction and making the protein immobile (i.e. bound inside the column) 2. As salt concentrations decrease, the protein-ligand interaction dissipates, the protein again becomes mobile and elutes from the column. Several HIC media are commercially available in pre-packed columns, each containing one of several hydrophobic ligands (e.g. S-butyl, butyl, octyl, and phenyl) cross-linked at varying densities to agarose beads of a specific diameter 3. Automated column scouting allows for an efficient approach for determining which HIC media

  17. A new divided-wall heat integrated distillation column (HIDiC) for batch processing: Feasibility and analysis

    International Nuclear Information System (INIS)

    Jana, Amiya K.

    2016-01-01

    Highlights: • A novel heat integrated configuration is proposed for batch distillation. • The shell is divided into two closed semi-cylinders by a metal wall. • An open-loop variable manipulation policy is formulated. • The column improves its energy efficiency and economic performance. - Abstract: This work introduces a new heat integrated distillation column (HIDiC) for batch processing. Under this scheme, the entire cylindrical shell is proposed to divide vertically by a metal wall into two closed semi-cylinders. Aiming to generate an internal heat source, a heat pump system is employed over the left hand division to elevate the pressure of the right hand part with the application of HIDiC concept. This new divided-wall HIDiC column utilizes its own energy source by transferring heat from the high pressure (HP) to low pressure (LP) side, thereby reducing the utility consumption in both the still and condenser. To make this thermal integration technology more effective, a typical tray configuration is proposed in both sides of the divided-wall. Unlike the continuous flow distillation, the batch column shows unsteady state process characteristics that make its operation more challenging. With this, an open-loop variable manipulation policy is formulated so that the dynamics of the heat integrated column remain close, if not same, with its conventional counterpart. This is a necessary condition required for a fair comparison between them. Finally, the proposed configuration is illustrated by a binary column, showing an improvement in energy savings, entropy generation and cost over its conventional analogous. This thermally integrated configuration is relatively simple than the traditional HIDiC in terms of design and operation.

  18. A small stone column of the altar screen from the treasures of St Archangel Michael's monastery in Prevlaka

    Directory of Open Access Journals (Sweden)

    Crnčević Dejan

    2013-01-01

    Full Text Available Amongst exhibited fragments of carved stone decorations in the monastery of St Archangel Michael in Prevlaka, Boka Kotorska, situated on the ground floor of the monastery's accommodation quarters, there is a segment of stone liturgical furnishings which is, among other things, distinguished by its monumental dimensions, the high level of its craftsmanship, and the important artistic value of its carved decorations. This small stone column was found by chance as a surface-level find on the neighbouring island of St Gavrilo. This stone column is made from a monolithic piece of high- quality, light-grey marble. It is 96 cm in height, 20 cm wide at the front, 18.5 cm wide at the side, and 13cm wide at the rear. These dimensions indicate that the fragment has the form of an elongated hexahedron, with sides of unequal width. Only the front of this stone fragment is marked with relief decorations, comprising a regularly shaped two-part curled sprouting vine. Moving with its undulating rhythm, its arc defines a space in which is located the central motif of the decoration. This comprises the motif of a bud in the form of stylised crinoline flower, composed of two lateral leaves with a pronounced bulge in the middle. These tightly bent lateral leaves with sharp ends, together with the root of the formed shoot, leave an empty space filled with an offshoot in the form of a regularly formed volute. The left lateral side of the stone column is marked by a long but relatively shallow channel, created around its axis, with a width of 7.5 cm. Its rear side is divided by its own height into two vertical fields, of almost the same width - 6 and 7 cm respectively - one slightly elevated compared to the other. The right lateral side of the column is slanted and only lightly sculptured. On the upper surface of the pillar, a relatively shallow circular hole with a small span is visible, intended as a connection point for other segments that would have been placed on

  19. Phonological decisions require both the left and right supramarginal gyri.

    Science.gov (United States)

    Hartwigsen, Gesa; Baumgaertner, Annette; Price, Cathy J; Koehnke, Maria; Ulmer, Stephan; Siebner, Hartwig R

    2010-09-21

    Recent functional imaging studies demonstrated that both the left and right supramarginal gyri (SMG) are activated when healthy right-handed subjects make phonological word decisions. However, lesion studies typically report difficulties with phonological processing after left rather than right hemisphere damage. Here, we used a unique dual-site transcranial magnetic stimulation (TMS) approach to test whether the SMG in the right hemisphere contributes to modality-independent (i.e., auditory and visual) phonological decisions. To test task-specificity, we compared the effect of real or sham TMS during phonological, semantic, and perceptual decisions. To test laterality and anatomical specificity, we compared the effect of TMS over the left, right, or bilateral SMG and angular gyri. The accuracy and reaction times of phonological decisions were selectively disrupted relative to semantic and perceptual decisions when real TMS was applied over the left, right, or bilateral SMG. These effects were not observed for TMS over the angular gyri. A follow-up experiment indicated that the threshold-intensity for inducing a disruptive effect on phonological decisions was identical for unilateral TMS over the right or left SMG. Taken together, these findings provide converging evidence that the right SMG contributes to accurate and efficient phonological decisions in the healthy brain, with no evidence that the left and right SMG can compensate for one another during TMS. Our findings motivate detailed studies of phonological processing in patients with acute or long-term damage of the right SMG.

  20. Vertebral column regionalisation in Chinook salmon, Oncorhynchus tshawytscha.

    Science.gov (United States)

    De Clercq, A; Perrott, M R; Davie, P S; Preece, M A; Wybourne, B; Ruff, N; Huysseune, A; Witten, P E

    2017-10-01

    Teleost vertebral centra are often similar in size and shape, but vertebral-associated elements, i.e. neural arches, haemal arches and ribs, show regional differences. Here we examine how the presence, absence and specific anatomical and histological characters of vertebral centra-associated elements can be used to define vertebral column regions in juvenile Chinook salmon (Oncorhynchus tshawytscha). To investigate if the presence of regions within the vertebral column is independent of temperature, animals raised at 8 and 12 °C were studied at 1400 and 1530 degreedays, in the freshwater phase of the life cycle. Anatomy and composition of the skeletal tissues of the vertebral column were analysed using Alizarin red S whole-mount staining and histological sections. Six regions, termed I-VI, are recognised in the vertebral column of specimens of both temperature groups. Postcranial vertebrae (region I) carry neural arches and parapophyses but lack ribs. Abdominal vertebrae (region II) carry neural arches and ribs that articulate with parapophyses. Elastic- and fibrohyaline cartilage and Sharpey's fibres connect the bone of the parapophyses to the bone of the ribs. In the transitional region (III) vertebrae carry neural arches and parapophyses change stepwise into haemal arches. Ribs decrease in size, anterior to posterior. Vestigial ribs remain attached to the haemal arches with Sharpey's fibres. Caudal vertebrae (region IV) carry neural and haemal arches and spines. Basidorsals and basiventrals are small and surrounded by cancellous bone. Preural vertebrae (region V) carry neural and haemal arches with modified neural and haemal spines to support the caudal fin. Ural vertebrae (region VI) carry hypurals and epurals that represent modified haemal and neural arches and spines, respectively. The postcranial and transitional vertebrae and their respective characters are usually recognised, but should be considered as regions within the vertebral column of teleosts

  1. Advantages in exploring a new environment with the left eye in lizards.

    Science.gov (United States)

    Bonati, Beatrice; Csermely, Davide; Sovrano, Valeria Anna

    2013-07-01

    Lizards (Podarcis muralis) preferentially use the left eye during spatial exploration in a binocular condition. Here we allowed 44 adult wild lizards to explore an unknown maze for 20 min under a temporary monocular condition whilst recording their movements, particularly the direction of turns made whilst walking within the maze. Lizards with a patch on their right eye, i.e. using their left eye to monitor the environment, moved faster than lizards with a patch on their left eye when turning both leftward and rightward in a T-cross. Hence, right eye-patched lizards were faster than left eye-patched lizards also in turning right, although their right eye was covered. Thus, lizards that could use the left eye/right hemisphere to attend spatial cues appeared to have more control and to be more prompt in exploring the maze. In addition, female lizards with their left eye covered stopped very frequently when they reached crosses, showing a high level of indecision. Results confirm that P. muralis lizards using their left eye only in exploring a new environment react faster and more efficiently than those using the right eye only in exploration. Hence lateralisation of spatial stimuli mediated by the left eye/right hemisphere could provide an advantage to this species. Copyright © 2013 Elsevier B.V. All rights reserved.

  2. Hydrodynamics of Bubble Columns: Turbulence and Population Balance Model

    Directory of Open Access Journals (Sweden)

    Camila Braga Vieira

    2018-03-01

    Full Text Available This paper presents an in-depth numerical analysis on the hydrodynamics of a bubble column. As in previous works on the subject, the focus here is on three important parameters characterizing the flow: interfacial forces, turbulence and inlet superficial Gas Velocity (UG. The bubble size distribution is taken into account by the use of the Quadrature Method of Moments (QMOM model in a two-phase Euler-Euler approach using the open-source Computational Fluid Dynamics (CFD code OpenFOAM (Open Field Operation and Manipulation. The interfacial forces accounted for in all the simulations presented here are drag, lift and virtual mass. For the turbulence analysis in the water phase, three versions of the Reynolds Averaged Navier-Stokes (RANS k-ε turbulence model are examined: namely, the standard, modified and mixture variants. The lift force proves to be of major importance for a trustworthy prediction of the gas volume fraction profiles for all the (superficial gas velocities tested. Concerning the turbulence, the mixture k-ε model is seen to provide higher values of the turbulent kinetic energy dissipation rate in comparison to the other models, and this clearly affects the prediction of the gas volume fraction in the bulk region, and the bubble-size distribution. In general, the modified k-ε model proves to be a good compromise between modeling simplicity and accuracy in the study of bubble columns of the kind undertaken here.

  3. Quasi-periodic oscillations from post-shock accretion column of polars

    Science.gov (United States)

    Bera, Prasanta; Bhattacharya, Dipankar

    2018-02-01

    A set of strongly magnetized accreting white dwarfs (polars) shows quasi-periodic oscillations (QPOs) with frequency about a Hz in their optical luminosity. These Hz-frequency QPOs are thought to be generated by intensity variations of the emitted radiation originating at the post-shock accretion column. Thermal instability in the post-shock region, triggered by efficient cooling process at the base, is believed to be the primary reason behind the temporal variability. Here, we study the structure and the dynamical properties of the post-shock accretion column including the effects of bremsstrahlung and cyclotron radiation. We find that the presence of significant cyclotron emission in optical band reduces the overall variability of the post-shock region. In the case of a larger post-shock region above the stellar surface, the effects of stratification due to stellar gravity become important. An accretion column, influenced by the strong gravity, has a smaller variability as the strength of the thermal instability at the base of the column is reduced. On the other hand, the cool, dense plasma, accumulated just above the stellar surface, may enhance the post-shock variability due to the propagation of magnetic perturbations. These characteristics of the post-shock region are consistent with the observed properties of V834 Cen and in general with cataclysmic variable sources that exhibit QPO frequency of about a Hz.

  4. Neglect severity after left and right brain damage.

    Science.gov (United States)

    Suchan, Julia; Rorden, Chris; Karnath, Hans-Otto

    2012-05-01

    While unilateral spatial neglect after left brain damage is undoubtedly less common than spatial neglect after a right hemisphere lesion, it is also assumed to be less severe. Here we directly test this latter hypothesis using a continuous measure of neglect severity: the so-called Center of Cancellation (CoC). Rorden and Karnath (2010) recently validated this index for right brain damaged neglect patients. A first aim of the present study was to evaluate this new measure for spatial neglect after left brain damage. In a group of 48 left-sided stroke patients with and without neglect, a score greater than -0.086 on the Bells Test and greater than -0.024 on the Letter Cancellation Task turned out to indicate neglect behavior for acute left brain damaged patients. A second aim was to directly compare the severity of spatial neglect after left versus right brain injury by using the new CoC measure. While neglect is less frequent following left than right hemisphere injury, we found that when this symptom occurs it is of similar severity in acute left brain injury as in patients after acute right brain injury. Copyright © 2012 Elsevier Ltd. All rights reserved.

  5. Single column and two-column H-D-T distillation experiments at TSTA

    International Nuclear Information System (INIS)

    Yamanishi, T.; Yoshida, H.; Hirata, S.; Naito, T.; Naruse, Y.; Sherman, R.H.; Bartlit, J.R.; Anderson, J.L.

    1988-01-01

    Cryogenic distillation experiments were peformed at TSTA with H-D-T system by using a single column and a two-column cascade. In the single column experiment, fundamental engineering data such as the liquid holdup and the HETP were measured under a variety of operational condtions. The liquid holdup in the packed section was about 10 /approximately/ 15% of its superficial volume. The HETP values were from 4 to 6 cm, and increased slightly with the vapor velocity. The reflux ratio had no effect on the HETP. For the wo-colunn experiemnt, dynamic behavior of the cascade was observed. 8 refs., 7 figs., 2 tabs

  6. Performance evaluation of a rectifier column using gamma column scanning

    Directory of Open Access Journals (Sweden)

    Aquino Denis D.

    2017-12-01

    Full Text Available Rectifier columns are considered to be a critical component in petroleum refineries and petrochemical processing installations as they are able to affect the overall performance of these facilities. It is deemed necessary to monitor the operational conditions of such vessels to optimize processes and prevent anomalies which could pose undesired consequences on product quality that might lead to huge financial losses. A rectifier column was subjected to gamma scanning using a 10-mCi Co-60 source and a 2-inch-long detector in tandem. Several scans were performed to gather information on the operating conditions of the column under different sets of operating parameters. The scan profiles revealed unexpected decreases in the radiation intensity at vapour levels between trays 2 and 3, and between trays 4 and 5. Flooding also occurred during several scans which could be attributed to parametric settings.

  7. Particle physics and the anthropology of right and left

    CERN Multimedia

    Arpita Roy

    We have all looked at ants at some point and wondered where they go about with so much dash and drive. Likewise I ask what drives so many competent and specialized people in this gigantic collaborative enterprise on the LHC at CERN. And I come at an interesting cross-section that is in a process to change soon with the LHC assuming operation from April 2008. But I am also here to learn something about physics. The metaphor of the ant is useful in describing my particular focus of interest: there is no reason why an ant should take one direction, rather than the other; the ant can select any direction. In an otherwise homogeneous space, what does right and left mean ? The distinction between right and left is not embedded in space itself, it is relative to each other and cannot be made unless the perspective from which it could be viewed is specified. Making this distinction of right and left is then a matter of social convention or custom. Physicists, philosophers, anthropologists alike have wondered why nat...

  8. HPLC-CUPRAC post-column derivatization method for the determination of antioxidants: a performance comparison between porous silica and core-shell column packing.

    Science.gov (United States)

    Haque, Syed A; Cañete, Socrates Jose P

    2018-01-01

    An HPLC method employing a post-column derivatization strategy using the cupric reducing antioxidant capacity reagent (CUPRAC reagent) for the determining antioxidants in plant-based materials leverages the separation capability of regular HPLC approaches while allowing for detection specificity for antioxidants. Three different column types, namely core-shell and porous silica including two chemically different core-shell materials (namely phenyl-hexyl and C18), were evaluated to assess potential improvements that could be attained by changing from a porous silica matrix to a core-shell matrix. Tea extracts were used as sample matrices for the evaluation specifically looking at catechin and epigallocatechin gallate (EGCG). Both the C18 and phenyl-hexyl core-shell columns showed better performance compared to the C18 porous silica one in terms of separation, peak shape, and retention time. Among the two core-shell materials, the phenyl-hexyl column showed better resolving power compared to the C18 column. The CUPRAC post-column derivatization method can be improved using core-shell columns and suitable for quantifying antioxidants, exemplified by catechin and EGCG, in tea samples.

  9. The dorsal tectal longitudinal column (TLCd): a second longitudinal column in the paramedian region of the midbrain tectum.

    Science.gov (United States)

    Aparicio, M-Auxiliadora; Saldaña, Enrique

    2014-03-01

    The tectal longitudinal column (TLC) is a longitudinally oriented, long and narrow nucleus that spans the paramedian region of the midbrain tectum of a large variety of mammals (Saldaña et al. in J Neurosci 27:13108-13116, 2007). Recent analysis of the organization of this region revealed another novel nucleus located immediately dorsal, and parallel, to the TLC. Because the name "tectal longitudinal column" also seems appropriate for this novel nucleus, we suggest the TLC described in 2007 be renamed the "ventral tectal longitudinal column (TLCv)", and the newly discovered nucleus termed the "dorsal tectal longitudinal column (TLCd)". This work represents the first characterization of the rat TLCd. A constellation of anatomical techniques was used to demonstrate that the TLCd differs from its surrounding structures (TLCv and superior colliculus) cytoarchitecturally, myeloarchitecturally, neurochemically and hodologically. The distinct expression of vesicular amino acid transporters suggests that TLCd neurons are GABAergic. The TLCd receives major projections from various areas of the cerebral cortex (secondary visual mediomedial area, and granular and dysgranular retrosplenial cortices) and from the medial pretectal nucleus. It densely innervates the ipsilateral lateral posterior and laterodorsal nuclei of the thalamus. Thus, the TLCd is connected with vision-related neural centers. The TLCd may be unique as it constitutes the only known nucleus made of GABAergic neurons dedicated to providing massive inhibition to higher order thalamic nuclei of a specific sensory modality.

  10. Reliability assessment of slender concrete columns at the stability failure

    Science.gov (United States)

    Valašík, Adrián; Benko, Vladimír; Strauss, Alfred; Täubling, Benjamin

    2018-01-01

    The European Standard for designing concrete columns within the use of non-linear methods shows deficiencies in terms of global reliability, in case that the concrete columns fail by the loss of stability. The buckling failure is a brittle failure which occurs without warning and the probability of its formation depends on the columns slenderness. Experiments with slender concrete columns were carried out in cooperation with STRABAG Bratislava LTD in Central Laboratory of Faculty of Civil Engineering SUT in Bratislava. The following article aims to compare the global reliability of slender concrete columns with slenderness of 90 and higher. The columns were designed according to methods offered by EN 1992-1-1 [1]. The mentioned experiments were used as basis for deterministic nonlinear modelling of the columns and subsequent the probabilistic evaluation of structural response variability. Final results may be utilized as thresholds for loading of produced structural elements and they aim to present probabilistic design as less conservative compared to classic partial safety factor based design and alternative ECOV method.

  11. Adiabatic packed column supercritical fluid chromatography using a dual-zone still-air column heater.

    Science.gov (United States)

    Helmueller, Shawn C; Poe, Donald P; Kaczmarski, Krzysztof

    2018-02-02

    An approach to conducting SFC separations under pseudo-adiabatic condition utilizing a dual-zone column heater is described. The heater allows for efficient separations at low pressures above the critical temperature by imposing a temperature profile along the column wall that closely matches that for isenthalpic expansion of the fluid inside the column. As a result, the efficiency loss associated with the formation of radial temperature gradients in this difficult region can be largely avoided in packed analytical scale columns. For elution of n-octadecylbenzene at 60 °C with 5% methanol modifier and a flow rate of 3 mL/min, a 250 × 4.6-mm column packed with 5-micron Kinetex C18 particles began to lose efficiency (8% decrease in the number of theoretical plates) at outlet pressures below 142 bar in a traditional forced air oven. The corresponding outlet pressure for onset of excess efficiency loss was decreased to 121 bar when the column was operated in a commercial HPLC column heater, and to 104 bar in the new dual-zone heater operated in adiabatic mode, with corresponding increases in the retention factor for n-octadecylbenzene from 2.9 to 6.8 and 14, respectively. This approach allows for increased retention and efficient separations of otherwise weakly retained analytes. Applications are described for rapid SFC separation of an alkylbenzene mixture using a pressure ramp, and isobaric separation of a cannabinoid mixture. Copyright © 2018 Elsevier B.V. All rights reserved.

  12. Compact electron beam focusing column

    Science.gov (United States)

    Persaud, Arun; Leung, Ka-Ngo; Reijonen, Jani

    2001-12-01

    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 2D 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.

  13. Bernstein modes in a non-neutral plasma column

    Science.gov (United States)

    Walsh, Daniel; Dubin, Daniel H. E.

    2018-05-01

    This paper presents theory and numerical calculations of electrostatic Bernstein modes in an inhomogeneous cylindrical plasma column. These modes rely on finite Larmor radius effects to propagate radially across the column until they are reflected when their frequency matches the upper hybrid frequency. This reflection sets up an internal normal mode on the column and also mode-couples to the electrostatic surface cyclotron wave (which allows the normal mode to be excited and observed using external electrodes). Numerical results predicting the mode spectra, using a novel linear Vlasov code on a cylindrical grid, are presented and compared to an analytical Wentzel Kramers Brillouin (WKB) theory. A previous version of the theory [D. H. E. Dubin, Phys. Plasmas 20(4), 042120 (2013)] expanded the plasma response in powers of 1/B, approximating the local upper hybrid frequency, and consequently, its frequency predictions are spuriously shifted with respect to the numerical results presented here. A new version of the WKB theory avoids this approximation using the exact cold fluid plasma response and does a better job of reproducing the numerical frequency spectrum. The effect of multiple ion species on the mode spectrum is also considered, to make contact with experiments that observe cyclotron modes in a multi-species pure ion plasma [M. Affolter et al., Phys. Plasmas 22(5), 055701 (2015)].

  14. Purex pulse column designs for capacity factor of 3.0 to 3.5

    Energy Technology Data Exchange (ETDEWEB)

    Richardson, G.L.

    1955-04-12

    This memorandum indicates the Purex-Plant pulse-column and pulse- generator revisions which would be required to assure an instantaneous capacity of 25 tons U/day with a 20% capacity safety margin under Purex HW {number_sign}3 Flowsheet conditions. (The use of the Purex HW {number_sign}4 Flowsheet (6) with the revised columns would be expected to increase the capacity to 29 or 30 tons U/day.) The indicated design changes are recorded here for study and for possible reference if need for increased production capacity should arise. No recommendation for adoption at this time is made.

  15. The New Left in the European Democracies: The Case of the German Radical Left

    Directory of Open Access Journals (Sweden)

    Marco Damiani

    2015-03-01

    Full Text Available The new form of the social and political conflict cannot be explained by the traditional categories of right and left, but it articulates to them on two plans, that of the establishment, intended like plan of the structured political conflict from the traditional actors, and that of the anti-establishment, in which new representations of politics emerge. The New Left is characterized by type of intermittent participation and new perspectives on mobilization inside the parties and the social movements. This type of parties differs moreover from the traditional ones left of the socialist and social democratic left in not arranging of organizations collaterals placed under the direction of the leadership of the same party. The mobilization that spontaneously assumes not conventional forms of active participation of the citizens, or is primed by the action of an associative network of which the same parties take part, than however does not monopo-lize the collective action. In this regard, the attention will be dedicated to the study of Die Linke: an anti-establishment party of the non-socialist German left-wing, heir to the communist tradition. The choice was affected to the German model because: 1 Germany is a country with a strong social democratic tradition, but 25 years after the fall of the Berlin Wall the German political system identifies a new antagonist political party; 2 Die Linke represents an interesting case in the political landscape of the European radical left because is a one-party that gives up at the federation of parties to try to unify the political parties of German radical left-wing.

  16. Thermal process of an air column

    International Nuclear Information System (INIS)

    Lee, F.T.

    1994-01-01

    Thermal process of a hot air column is discussed based on laws of thermodynamics. The kinetic motion of the air mass in the column can be used as a power generator. Alternatively, the column can also function as a exhaust/cooler

  17. Column gamma-ray scanning of the 'Hector Molina' Distillery

    International Nuclear Information System (INIS)

    Derivet Zarzabal, M.; Capote Ferrera, E.; Fernandez Gomez, I.; Carrazana Gonzalez, L.; Borroto Portela, J.

    2015-01-01

    Gamma-ray scanning, often referred to as 'column scanning', is a convenient, cost effective, fast, efficient and non-invasive technique to examine internal characteristics of a certain equipment, like alcohol distillation columns, while it is in operation. Column scanning allows to engineers, to study hydraulics tray inside of distillation column in on-line condition. It provides essential data to optimize the performance of columns, extend column run times, to evaluate effects of defective track and to identify maintenance requirements. This knowledge can reduce repair times significantly. In the year 2014, the Environmental Radiological Surveillance Laboratory from Center of Radiation Protection and Hygiene, introduced this service in the 'Hector Molina' Distillery. The diagnosis carried out allowed the detection of some anomalies in its operation. In this work the results obtained during gamma-ray scanning of the column are shown. (Author)

  18. The O VI Mystery: Mismatch between X-Ray and UV Column Densities

    Science.gov (United States)

    Mathur, S.; Nicastro, F.; Gupta, A.; Krongold, Y.; McLaughlin, B. M.; Brickhouse, N.; Pradhan, A.

    2017-12-01

    The UV spectra of Galactic and extragalactic sightlines often show O VI absorption lines at a range of redshifts, and from a variety of sources from the Galactic circumgalactic medium to active galactic nuclei (AGN) outflows. Inner shell O VI absorption is also observed in X-ray spectra (at λ =22.03 Å), but the column density inferred from the X-ray line was consistently larger than that from the UV line. Here we present a solution to this discrepancy for the z = 0 systems. The O II Kβ line {}4{S}0\\to {(}3D)3{p}4P at 562.40 eV (≡22.04 Å) is blended with the O VI Kα line in X-ray spectra. We estimate the strength of this O II line in two different ways, and show that in most cases the O II line accounts for the entire blended line. The small amount of O VI equivalent width present in some cases has column density entirely consistent with the UV value. This solution to the O VI discrepancy, however, does not apply to high column-density systems like AGN outflows. We discuss other possible causes to explain their UV/X-ray mismatch. The O VI and O II lines will be resolved by gratings on board the proposed mission Arcus and the concept mission Lynx, and would allow the detection of weak O VI lines not just at z = 0, but also at higher redshift.

  19. Approaches to characterise chromatographic column performance based on global parameters accounting for peak broadening and skewness.

    Science.gov (United States)

    Baeza-Baeza, J J; Pous-Torres, S; Torres-Lapasió, J R; García-Alvarez-Coque, M C

    2010-04-02

    Peak broadening and skewness are fundamental parameters in chromatography, since they affect the resolution capability of a chromatographic column. A common practice to characterise chromatographic columns is to estimate the efficiency and asymmetry factor for the peaks of one or more solutes eluted at selected experimental conditions. This has the drawback that the extra-column contributions to the peak variance and skewness make the peak shape parameters depend on the retention time. We propose and discuss here the use of several approaches that allow the estimation of global parameters (non-dependent on the retention time) to describe the column performance. The global parameters arise from different linear relationships that can be established between the peak variance, standard deviation, or half-widths with the retention time. Some of them describe exclusively the column contribution to the peak broadening, whereas others consider the extra-column effects also. The estimation of peak skewness was also possible for the approaches based on the half-widths. The proposed approaches were applied to the characterisation of different columns (Spherisorb, Zorbax SB, Zorbax Eclipse, Kromasil, Chromolith, X-Terra and Inertsil), using the chromatographic data obtained for several diuretics and basic drugs (beta-blockers). Copyright (c) 2010 Elsevier B.V. All rights reserved.

  20. Quantitative description of the regional mechanics of the left atria by electroanatomical mapping

    International Nuclear Information System (INIS)

    Kuklik, Pawel; Molaee, Payman; Brooks, Anthony G; John, Bobby; Worthley, Stephen G; Sanders, Prashanthan

    2010-01-01

    The left atrium is a complex chamber, which plays an integral role in the maintenance of physiologic hemodynamic and electrical stability of the heart and is involved in many disease states, most commonly atrial fibrillation. Preserving regions of the left atrium that contribute the greatest to atrial mechanical function during curative strategies for atrial fibrillation are important. We present here a new application of the CARTO electroanatomical mapping system in the assessment of the left atria mechanical function. Electroanatomical data were collected in course of the electrophysiological procedure in 11 control patients and 12 patients with paroxysmal atrial fibrillation. The three-dimensional geometry of the left atria was reconstructed in 10 ms intervals and segmented into distinct regions. For each segment, a regional ejection fraction was calculated. We found that anterior, septal and lateral segments have significantly greater regional ejection fraction than atria roof, inferior and posterior segments. Therefore, we hypothesize that in order to minimize the impact on atrial mechanical function, an important determinant of thromboembolic risk, damage should be minimized to these atrial regions

  1. Solvent extraction columns

    International Nuclear Information System (INIS)

    Middleton, P.; Smith, J.R.

    1979-01-01

    In pulsed columns for use in solvent extraction processes, e.g. the reprocessing of nuclear fuel, the horizontal perforated plates inside the column are separated by interplate spacers manufactured from metallic neutron absorbing material. The spacer may be in the form of a spiral or concentric circles separated by radial limbs, or may be of egg-box construction. Suitable neutron absorbing materials include stainless steel containing boron or gadolinium, hafnium metal or alloys of hafnium. (UK)

  2. Impact of Holes on the Buckling of RHS Steel Column

    Directory of Open Access Journals (Sweden)

    Najla'a H. AL-Shareef

    2018-03-01

    Full Text Available This study presented an experimental and theoretical study on the effect of hole on the behavior of rectangular hollow steel columns subjected to axial compression load. Specimens were tested to investigated the ultimate capacity and the load- axial displacement behavior of steel columns. In this paper finite element analysis is done by using general purpose ANSYS 12.0 to investigate the behavior of rectangular hollow steel column with hole. In the experimental work, rectangular hollow steel columns with rounded corners were used in the constriction of the specimens which have dimensions of cross section (50*80mm and height of (250 and 500mm with thickness of (1.25,4 and 6mm with hole ((α*80*80mm when α is equal to (0.2,0.4,0.6 and 0.8. Twenty four columns under compression load were tested in order to investigate the effect of hole on the ultimate load of rectangular hollow steel column. The experimental results indicated that the typical failure  mode for all the tested hollow specimen was the local buckling. The tested results indicated that the increasing of hole dimension leads to reduction in ultimate loads of tested column to 75%. The results show the reducing of load by 94.7% due to decreasing  the thickness of  column while the hole size is constant (0.2*80*80. The buckling load decreases by 84.62% when hole position changes from Lo=0.25L to 0.75L. Holes can be made in the middle of column with dimension up to 0.4 of column's length. The AISC (2005 presents the values closest to the experimental results for the nominal yielding compressive strength. The effect for increasing of slendeness ratio and thickness to area ratio(t/A leading to decreacing the critical stresses and the failure of column with large size of hole and (t/A ratio less than 0.74% was due to lacal  buckling while the global buckling failure was abserve for column with small size of hole and (t/A ratio above than 0.74%. The compersion  between the experimental

  3. TMS over the Left Angular Gyrus Impairs the Ability to Discriminate Left from Right

    Science.gov (United States)

    Hirnstein, Marco; Bayer, Ulrike; Ellison, Amanda; Hausmann, Markus

    2011-01-01

    The underlying cognitive and neural mechanisms of the ability to discriminate left from right are hardly explored. Clinical studies from patients with impairments of left-right discrimination (LRD) and neuroimaging data suggest that the left angular gyrus is particularly involved in LRD. Moreover, it is argued that the often reported sex…

  4. PULSE COLUMN

    Science.gov (United States)

    Grimmett, E.S.

    1964-01-01

    This patent covers a continuous countercurrent liquidsolids contactor column having a number of contactor states each comprising a perforated plate, a layer of balls, and a downcomer tube; a liquid-pulsing piston; and a solids discharger formed of a conical section at the bottom of the column, and a tubular extension on the lowest downcomer terminating in the conical section. Between the conical section and the downcomer extension is formed a small annular opening, through which solids fall coming through the perforated plate of the lowest contactor stage. This annular opening is small enough that the pressure drop thereacross is greater than the pressure drop upward through the lowest contactor stage. (AEC)

  5. Dynamic Deformation and Collapse of Granular Columns

    Science.gov (United States)

    Uenishi, K.; Tsuji, K.; Doi, S.

    2009-12-01

    Large dynamic deformation of granular materials may be found in nature not only in the failure of slopes and cliffs — due to earthquakes, rock avalanches, debris flows and landslides — but also in earthquake faulting itself. Granular surface flows often consist of solid grains and intergranular fluid, but the effect of the fluid may be usually negligible because the volumetric concentration of grains is in many cases high enough for interparticle forces to dominate momentum transport. Therefore, the investigation of dry granular flow of a mass might assist in further understanding of the above mentioned geophysical events. Here, utilizing a high-speed digital video camera system, we perform a simple yet fully-controlled series of laboratory experiments related to the collapse of granular columns. We record, at an interval of some microseconds, the dynamic transient granular mass flow initiated by abrupt release of a tube that contains dry granular materials. The acrylic tube is partially filled with glass beads and has a cross-section of either a fully- or semi-cylindrical shape. Upon sudden removal of the tube, the granular solid may fragment under the action of its own weight and the particles spread on a rigid horizontal plane. This study is essentially the extension of the previous ones by Lajeunesse et al. (Phys. Fluids 2004) and Uenishi and Tsuji (JPGU 2008), but the striped layers of particles in a semi-cylindrical tube, newly introduced in this contribution, allow us to observe the precise particle movement inside the granular column: The development of slip lines inside the column and the movement of particles against each other can be clearly identified. The major controlling parameters of the spreading dynamics are the initial aspect ratio of the granular (semi-)cylindrical column, the frictional properties of the horizontal plane (substrate) and the size of beads. We show the influence of each parameter on the average flow velocity and final radius

  6. Performance of RC columns with partial length corrosion

    International Nuclear Information System (INIS)

    Wang Xiaohui; Liang Fayun

    2008-01-01

    Experimental and analytical studies on the load capacity of reinforced concrete (RC) columns with partial length corrosion are presented, where only a fraction of the column length was corroded. Twelve simply supported columns were eccentrically loaded. The primary variables were partial length corrosion in tensile or compressive zone and the corrosion level within this length. The failure of the corroded column occurs in the partial length, mainly developed from or located nearby or merged with the longitudinal corrosion cracks. For RC column with large eccentricity, load capacity of the column is mainly influenced by the partial length corrosion in tensile zone; while for RC column with small eccentricity, load capacity of the column greatly decreases due to the partial length corrosion in compressive zone. The destruction of the longitudinally mechanical integrality of the column in the partial length leads to this great reduction of the load capacity of the RC column

  7. Non-compact left ventricle/hypertrabeculated left ventricle

    International Nuclear Information System (INIS)

    Restrepo, Gustavo; Castano, Rafael; Marmol, Alejandro

    2005-01-01

    Non-compact left ventricle/hypertrabeculated left ventricle is a myocardiopatie produced by an arrest of the normal left ventricular compaction process during the early embryogenesis. It is associated to cardiac anomalies (congenital cardiopaties) as well as to extracardial conditions (neurological, facial, hematologic, cutaneous, skeletal and endocrinological anomalies). This entity is frequently unnoticed, being diagnosed only in centers with great experience in the diagnosis and treatment of myocardiopathies. Many cases of non-compact left ventricle have been initially misdiagnosed as hypertrophic myocardiopatie, endocardial fibroelastosis, dilated cardiomyopatie, restrictive cardiomyopathy and endocardial fibrosis. It is reported the case of a 74 years old man with a history of chronic arterial hypertension and diabetes mellitus, prechordial chest pain and mild dyspnoea. An echocardiogram showed signs of non-compact left ventricle with prominent trabeculations and deep inter-trabecular recesses involving left ventricular apical segment and extending to the lateral and inferior walls. Literature on this topic is reviewed

  8. A stochastic view on column efficiency.

    Science.gov (United States)

    Gritti, Fabrice

    2018-03-09

    A stochastic model of transcolumn eddy dispersion along packed beds was derived. It was based on the calculation of the mean travel time of a single analyte molecule from one radial position to another. The exchange mechanism between two radial positions was governed by the transverse dispersion of the analyte across the column. The radial velocity distribution was obtained by flow simulations in a focused-ion-beam scanning electron microscopy (FIB-SEM) based 3D reconstruction from a 2.1 mm × 50 mm column packed with 2 μm BEH-C 18 particles. Accordingly, the packed bed was divided into three coaxial and uniform zones: (1) a 1.4 particle diameter wide, ordered, and loose packing at the column wall (velocity u w ), (2) an intermediate 130 μm wide, random, and dense packing (velocity u i ), and (3) the bulk packing in the center of the column (velocity u c ). First, the validity of this proposed stochastic model was tested by adjusting the predicted to the observed reduced van Deemter plots of a 2.1 mm × 50 mm column packed with 2 μm BEH-C 18 fully porous particles (FPPs). An excellent agreement was found for u i  = 0.93u c , a result fully consistent with the FIB-SEM observation (u i  = 0.95u c ). Next, the model was used to measure u i  = 0.94u c for 2.1 mm × 100 mm column packed with 1.6 μm Cortecs-C 18 superficially porous particles (SPPs). The relative velocity bias across columns packed with SPPs is then barely smaller than that observed in columns packed with FPPs (+6% versus + 7%). u w =1.8u i is measured for a 75 μm × 1 m capillary column packed with 2 μm BEH-C 18 particles. Despite this large wall-to-center velocity bias (+80%), the presence of the thin and ordered wall packing layer has no negative impact on the kinetic performance of capillary columns. Finally, the stochastic model of long-range eddy dispersion explains why analytical (2.1-4.6 mm i.d.) and capillary (columns can all be

  9. Ischemic Colitis of the Left Colon in a Diabetic Patient

    Directory of Open Access Journals (Sweden)

    Anastasios J. Karayiannakis

    2011-04-01

    Full Text Available Diabetes mellitus may affect the gastrointestinal tract possibly as a result of autonomic neuropathy. Here we present a 68-year-old male with non-insulin-dependent diabetes mellitus who presented with prolonged watery diarrhea and in whom imaging studies demonstrated ischemic colitis of the left colon. Resection of the affected colon resulted in sustained disappearance of symptoms.

  10. Left atrial systolic force in hypertensive patients with left ventricular hypertrophy: the LIFE study

    DEFF Research Database (Denmark)

    Chinali, M.; Simone, G. de; Wachtell, K.

    2008-01-01

    In hypertensive patients without prevalent cardiovascular disease, enhanced left atrial systolic force is associated with left ventricular hypertrophy and increased preload. It also predicts cardiovascular events in a population with high prevalence of obesity. Relations between left atrial...... systolic force and left ventricular geometry and function have not been investigated in high-risk hypertrophic hypertensive patients. Participants in the Losartan Intervention For Endpoint reduction in hypertension echocardiography substudy without prevalent cardiovascular disease or atrial fibrillation (n...... = 567) underwent standard Doppler echocardiography. Left atrial systolic force was obtained from the mitral orifice area and Doppler mitral peak A velocity. Patients were divided into groups with normal or increased left atrial systolic force (>14.33 kdyn). Left atrial systolic force was high in 297...

  11. Adsorption columns for use in radioimmunoassays

    International Nuclear Information System (INIS)

    1976-01-01

    Adsorption columns are provided which can be utilized in radioimmunoassay systems such as those involving the separation of antibody-antigen complexes from free antigens. The preparation of the columns includes the treatment of retaining substrate material to render it hydrophilic, preparation and degassing of the separation material and loading the column

  12. Opposing nodal and BMP signals regulate left-right asymmetry in the sea urchin larva.

    Directory of Open Access Journals (Sweden)

    Yi-Jyun Luo

    Full Text Available Nodal and BMP signals are important for establishing left-right (LR asymmetry in vertebrates. In sea urchins, Nodal signaling prevents the formation of the rudiment on the right side. However, the opposing pathway to Nodal signaling during LR axis establishment is not clear. Here, we revealed that BMP signaling is activated in the left coelomic pouch, specifically in the veg2 lineage, but not in the small micromeres. By perturbing BMP activities, we demonstrated that BMP signaling is required for activating the expression of the left-sided genes and the formation of the left-sided structures. On the other hand, Nodal signals on the right side inhibit BMP signaling and control LR asymmetric separation and apoptosis of the small micromeres. Our findings show that BMP signaling is the positive signal for left-sided development in sea urchins, suggesting that the opposing roles of Nodal and BMP signals in establishing LR asymmetry are conserved in deuterostomes.

  13. Left-right symmetry breaking in mice by left-right dynein may occur via a biased chromatid segregation mechanism, without directly involving the Nodal gene

    Energy Technology Data Exchange (ETDEWEB)

    Sauer, Stephan; Klar, Amar J. S., E-mail: sauers@mail.nih.gov, E-mail: klara@mail.nih.gov [Gene Regulation and Chromosome Biology Laboratory, Frederick National Laboratory for Cancer Research, Frederick, MD (United States)

    2012-11-16

    Ever since cloning the classic iv (inversedviscerum) mutation identified theleft-right dynein” (lrd) gene in mice, most research on body laterality determination has focused on its function in motile cilia at the node embryonic organizer. This model is attractive, as it links chirality of cilia architecture to asymmetry development. However, lrd is also expressed in blastocysts and embryonic stem cells, where it was shown to bias the segregation of recombined sister chromatids away from each other in mitosis. These data suggested that lrd is part of a cellular mechanism that recognizes and selectively segregates sister chromatids based on their replication history: old “Watson” versus old “Crick” strands. We previously proposed that the mouse left-right axis is established via an asymmetric cell division prior to/or during gastrulation. In this model, left-right dynein selectively segregates epigenetically differentiated sister chromatids harboring a hypothetical “left-right axis development 1” (“lra1”) gene during the left-right axis establishing cell division. Here, asymmetry development would be ultimately governed by the chirality of the cytoskeleton and the DNA molecule. Our model predicts that randomization of chromatid segregation in lrd mutants should produce embryos with 25% situs solitus, 25% situs inversus, and 50% embryonic death due to heterotaxia and isomerism. Here we confirmed this prediction by using two distinct lrd mutant alleles. Other than lrd, thus far Nodal gene is the most upstream function implicated in visceral organs laterality determination. We next tested whether the Nodal gene constitutes the lra1 gene hypothesized in the model by testing mutant’s effect on 50% embryonic lethality observed in lrd mutants. Since Nodal mutation did not suppress lethality, we conclude that Nodal is not equivalent to the lra1 gene. In summary, we describe the origin of 50% lethality in lrd mutant mice not yet explained by any other

  14. Left-right symmetry breaking in mice by left-right dynein may occur via a biased chromatid segregation mechanism, without directly involving the Nodal gene

    International Nuclear Information System (INIS)

    Sauer, Stephan; Klar, Amar J. S.

    2012-01-01

    Ever since cloning the classic iv (inversedviscerum) mutation identified theleft-right dynein” (lrd) gene in mice, most research on body laterality determination has focused on its function in motile cilia at the node embryonic organizer. This model is attractive, as it links chirality of cilia architecture to asymmetry development. However, lrd is also expressed in blastocysts and embryonic stem cells, where it was shown to bias the segregation of recombined sister chromatids away from each other in mitosis. These data suggested that lrd is part of a cellular mechanism that recognizes and selectively segregates sister chromatids based on their replication history: old “Watson” versus old “Crick” strands. We previously proposed that the mouse left-right axis is established via an asymmetric cell division prior to/or during gastrulation. In this model, left-right dynein selectively segregates epigenetically differentiated sister chromatids harboring a hypothetical “left-right axis development 1” (“lra1”) gene during the left-right axis establishing cell division. Here, asymmetry development would be ultimately governed by the chirality of the cytoskeleton and the DNA molecule. Our model predicts that randomization of chromatid segregation in lrd mutants should produce embryos with 25% situs solitus, 25% situs inversus, and 50% embryonic death due to heterotaxia and isomerism. Here we confirmed this prediction by using two distinct lrd mutant alleles. Other than lrd, thus far Nodal gene is the most upstream function implicated in visceral organs laterality determination. We next tested whether the Nodal gene constitutes the lra1 gene hypothesized in the model by testing mutant’s effect on 50% embryonic lethality observed in lrd mutants. Since Nodal mutation did not suppress lethality, we conclude that Nodal is not equivalent to the lra1 gene. In summary, we describe the origin of 50% lethality in lrd mutant mice not yet explained by any other

  15. Left-right symmetry breaking in mice by left-right dynein may occur via a biased chromatid segregation mechanism, without directly involving the Nodal gene

    Directory of Open Access Journals (Sweden)

    Stephan eSauer

    2012-11-01

    Full Text Available Ever since cloning the classic iv mutation identified theleft-right dynein’ (lrd gene in mice, most research on body laterality determination has focused on its function in motile cilia at the node embryonic organizer. This model is attractive, as it links chirality of cilia architecture to asymmetry development. However, lrd is also expressed in blastocysts and embryonic stem cells, where it was shown to bias the segregation of recombined sister chromatids away from each other in mitosis. These data suggested that lrd is part of a cellular mechanism that recognizes and selectively segregates sister chromatids based on their replication history: old ‘Watson’ vs. old ‘Crick’ strands. We previously proposed that the mouse left-right axis is established via an asymmetric cell division prior to/or during gastrulation. In this model, left-right dynein selectively segregates epigenetically differentiated sister chromatids harboring a hypothetical ‘left-right axis development 1’ (‘lra1’ gene during the left-right axis establishing cell division. Here, asymmetry development would be ultimately governed by the chirality of the cytoskeleton and the DNA molecule. Our model predicts that randomization of chromatid segregation in lrd mutants should produce embryos with 25% situs solitus, 25% situs inversus, and 50% embryonic death due to heterotaxia and isomerism. Here we confirmed this prediction by using two distinct lrd mutant alleles. Other than lrd, thus far Nodal gene is the most upstream function implicated in visceral organs laterality determination. We next tested whether the Nodal gene constitutes the lra1 gene hypothesized in the model by testing mutant’s effect on 50% embryonic lethality observed in lrd mutants. Since Nodal mutation did not suppress lethality, we conclude that Nodal is not equivalent to the lra1 gene. In summary, we describe the origin of 50% lethality in lrd mutant mice not yet explained by any other

  16. Looking at a predator with the left or right eye: asymmetry of response in lizards.

    Science.gov (United States)

    Bonati, Beatrice; Csermely, Davide; Sovrano, Valeria Anna

    2013-01-01

    Studies carried out with the common wall lizard (Podarcis muralis) revealed preferential use of the left eye during responses to predatory threat in laboratory settings and in the wild. Here we tested lizards under monocular conditions of vision, using temporary eye-patching. Lizards were facing a (simulated) predatory threat laterally, from the side of the non-patched eye. Results showed that lizards with the left eye uncovered during predatory threat used the left eye to monitor the predator, whereas lizards with the right eye uncovered nonetheless tried to use the covered left eye. Moreover, lizards frequently tried to change the eye exposition, making a body C-bend behaviour. Right-eyed lizards showed more frequent and faster C-bending responses than left-eyed lizards, trying to monitor the predator with the left eye even though it was patched. Results fit with asymmetries in spontaneous eye use observed in laboratory conditions and in the wild in this species, confirming that structures located on the right side of the brain (mainly served by the left eye) predominantly attend to predatory threat.

  17. Contribution of hedgehog signaling to the establishment of left-right asymmetry in the sea urchin.

    Science.gov (United States)

    Warner, Jacob F; Miranda, Esther L; McClay, David R

    2016-03-15

    Most bilaterians exhibit a left-right asymmetric distribution of their internal organs. The sea urchin larva is notable in this regard since most adult structures are generated from left sided embryonic structures. The gene regulatory network governing this larval asymmetry is still a work in progress but involves several conserved signaling pathways including Nodal, and BMP. Here we provide a comprehensive analysis of Hedgehog signaling and it's contribution to left-right asymmetry. We report that Hh signaling plays a conserved role to regulate late asymmetric expression of Nodal and that this regulation occurs after Nodal breaks left-right symmetry in the mesoderm. Thus, while Hh functions to maintain late Nodal expression, the molecular asymmetry of the future coelomic pouches is locked in. Furthermore we report that cilia play a role only insofar as to transduce Hh signaling and do not have an independent effect on the asymmetry of the mesoderm. From this, we are able to construct a more complete regulatory network governing the establishment of left-right asymmetry in the sea urchin. Copyright © 2016 Elsevier Inc. All rights reserved.

  18. Repair of aorto-left ventricular tunnel arising from the left sinus of valsalva.

    Science.gov (United States)

    Nezafati, Mohammad Hassan; Maleki, Mahmood Hosseinzadeh; Javan, Hadi; Zirak, Nahid

    2010-05-01

    Aortico-left ventricular tunnel (ALVT) is a rare congenital cardiac defect that bypasses the aortic valve via a para-valvular connection from the left ventricle to the aorta. In most cases, the tunnel arises from the right aortic sinus. In this case report, we are presenting a case of ALVT, of which the aortic orifice arose from the left aortic sinus, requiring special attention to avoid the left coronary artery injury at the time of surgical repair.

  19. Robust predictive control of a gasoline debutanizer column

    Directory of Open Access Journals (Sweden)

    E. Almeida Neto

    2000-12-01

    Full Text Available This paper studies the application of Model Predictive Control to moderately nonlinear processes. The system used in this work is an industrial gasoline debutanizer column. The paper presents two new formulations of MPC: MMPC (Multi-Model Predictive Controller and RSMPC (Robust Stable MPC. The approach is based on the concepts of Linear Matrix Inequalities (LMI, which have been recently introduced in the MPC field. Model uncertainty is considered by assuming that the true process model belongs to a convex set (polytope of possible plants. The controller has guaranteed stability when a Lyapunov type inequality constraint is included in the MPC problem. In the debutanizer column, several nonlinearities are present in the advanced control level when the manipulated inputs are the reflux flow and the reboiler heat duty. In most cases the controlled outputs are the contents of C5+ (pentane and heavier hydrocarbons in the LPG (Liquefied Petroleum Gas and the gasoline vapor pressure (P VR. In this case the QDMC algorithm which is usually applied to the debutanizer column has a poor performance and stability problems reflected in an oscillatory behavior of the process. The new approach considers several process models representing different operating conditions where linear models are identified. The results presented here show that the multimodel controller is capable of controlling the process in the entire operating window while the conventional MPC has a limited operating range.

  20. Denitrification in the water column of the central Baltic Sea

    DEFF Research Database (Denmark)

    Dalsgaard, Tage; De Brabandere, Loreto; Hall, Per O. J.

    2013-01-01

    Removal of fixed nitrogen in the water column of the eastern Gotland Basin, central Baltic Sea, was studied during two cruises in September 2008 and August 2010. The water column was stratified with anoxic sulfidic bottom water meeting oxic nitrate containing water at the oxic–anoxic interface......3 or sulfide concentrations were converted to in situ rates using the measured water column concentrations of NO3 and sulfide and the actual measured relations between NO3 and sulfide concentrations and enitrification rates. In situ denitrification ranged from 0.24 to 15.9 nM N2 h1. Assuming...... area. Even with an active denitrification layer of 3–6 m thickness the pelagic denitrification per unit area clearly exceeded sediment denitrification rates elsewhere in the Baltic Sea. When extrapolated to the entire Baltic Proper (BP) denitrification in the water column was in the range of 132...

  1. Evaluation of Packed Distillation Columns I - Atmospheric Pressure

    National Research Council Canada - National Science Library

    Reynolds, Thaine

    1951-01-01

    .... Four column-packing combinations of the glass columns and four column-packing combinations of the steel columns were investigated at atmospheric pressure using a test mixture of methylcyclohexane...

  2. A Theory of How Columns in the Neocortex Enable Learning the Structure of the World

    Directory of Open Access Journals (Sweden)

    Jeff Hawkins

    2017-10-01

    Full Text Available Neocortical regions are organized into columns and layers. Connections between layers run mostly perpendicular to the surface suggesting a columnar functional organization. Some layers have long-range excitatory lateral connections suggesting interactions between columns. Similar patterns of connectivity exist in all regions but their exact role remain a mystery. In this paper, we propose a network model composed of columns and layers that performs robust object learning and recognition. Each column integrates its changing input over time to learn complete predictive models of observed objects. Excitatory lateral connections across columns allow the network to more rapidly infer objects based on the partial knowledge of adjacent columns. Because columns integrate input over time and space, the network learns models of complex objects that extend well beyond the receptive field of individual cells. Our network model introduces a new feature to cortical columns. We propose that a representation of location relative to the object being sensed is calculated within the sub-granular layers of each column. The location signal is provided as an input to the network, where it is combined with sensory data. Our model contains two layers and one or more columns. Simulations show that using Hebbian-like learning rules small single-column networks can learn to recognize hundreds of objects, with each object containing tens of features. Multi-column networks recognize objects with significantly fewer movements of the sensory receptors. Given the ubiquity of columnar and laminar connectivity patterns throughout the neocortex, we propose that columns and regions have more powerful recognition and modeling capabilities than previously assumed.

  3. Column-oriented database management systems

    OpenAIRE

    Možina, David

    2013-01-01

    In the following thesis I will present column-oriented database. Among other things, I will answer on a question why there is a need for a column-oriented database. In recent years there have been a lot of attention regarding a column-oriented database, even if the existence of a columnar database management systems dates back in the early seventies of the last century. I will compare both systems for a database management – a colum-oriented database system and a row-oriented database system ...

  4. Partial Path Column Generation for the Vehicle Routing Problem

    DEFF Research Database (Denmark)

    Jepsen, Mads Kehlet; Petersen, Bjørn

    This paper presents a column generation algorithm for the Capacitated Vehicle Routing Problem (CVRP) and the Vehicle Routing Problem with Time Windows (VRPTW). Traditionally, column generation models of the CVRP and VRPTW have consisted of a Set Partitioning master problem with each column...... of the giant tour’; a so-called partial path, i.e., not necessarily starting and ending in the depot. This way, the length of the partial path can be bounded and a better control of the size of the solution space for the pricing problem can be obtained....

  5. Left regular bands of groups of left quotients

    International Nuclear Information System (INIS)

    El-Qallali, A.

    1988-10-01

    A semigroup S which has a left regular band of groups as a semigroup of left quotients is shown to be the semigroup which is a left regular band of right reversible cancellative semigroups. An alternative characterization is provided by using spinned products. These results are applied to the case where S is a superabundant whose set of idempotents forms a left normal band. (author). 13 refs

  6. Reconciliation of Halogen-Induced Ozone Loss with the Total-Column Ozone Record

    Science.gov (United States)

    Shepherd, T. G.; Plummer, D. A.; Scinocca, J. F.; Hegglin, M. I.; Fioletov, V. E.; Reader, M. C.; Remsberg, E.; von Clarmann, T.; Wang, H. J.

    2014-01-01

    The observed depletion of the ozone layer from the 1980s onwards is attributed to halogen source gases emitted by human activities. However, the precision of this attribution is complicated by year-to-year variations in meteorology, that is, dynamical variability, and by changes in tropospheric ozone concentrations. As such, key aspects of the total-column ozone record, which combines changes in both tropospheric and stratospheric ozone, remain unexplained, such as the apparent absence of a decline in total-column ozone levels before 1980, and of any long-term decline in total-column ozone levels in the tropics. Here we use a chemistry-climate model to estimate changes in halogen-induced ozone loss between 1960 and 2010; the model is constrained by observed meteorology to remove the eects of dynamical variability, and driven by emissions of tropospheric ozone precursors to separate out changes in tropospheric ozone. We show that halogen-induced ozone loss closely followed stratospheric halogen loading over the studied period. Pronounced enhancements in ozone loss were apparent in both hemispheres following the volcanic eruptions of El Chichon and, in particular, Mount Pinatubo, which significantly enhanced stratospheric aerosol loads. We further show that approximately 40% of the long-term non-volcanic ozone loss occurred before 1980, and that long-term ozone loss also occurred in the tropical stratosphere. Finally, we show that halogeninduced ozone loss has declined by over 10% since stratospheric halogen loading peaked in the late 1990s, indicating that the recovery of the ozone layer is well underway.

  7. Radiotracer Imaging of Sediment Columns

    Science.gov (United States)

    Moses, W. W.; O'Neil, J. P.; Boutchko, R.; Nico, P. S.; Druhan, J. L.; Vandehey, N. T.

    2010-12-01

    Nuclear medical PET and SPECT cameras routinely image radioactivity concentration of gamma ray emitting isotopes (PET - 511 keV; SPECT - 75-300 keV). We have used nuclear medical imaging technology to study contaminant transport in sediment columns. Specifically, we use Tc-99m (T1/2 = 6 h, Eγ = 140 keV) and a SPECT camera to image the bacteria mediated reduction of pertechnetate, [Tc(VII)O4]- + Fe(II) → Tc(IV)O2 + Fe(III). A 45 mL bolus of Tc-99m (32 mCi) labeled sodium pertechnetate was infused into a column (35cm x 10cm Ø) containing uranium-contaminated subsurface sediment from the Rifle, CO site. A flow rate of 1.25 ml/min of artificial groundwater was maintained in the column. Using a GE Millennium VG camera, we imaged the column for 12 hours, acquiring 44 frames. As the microbes in the sediment were inactive, we expected most of the iron to be Fe(III). The images were consistent with this hypothesis, and the Tc-99m pertechnetate acted like a conservative tracer. Virtually no binding of the Tc-99m was observed, and while the bolus of activity propagated fairly uniformly through the column, some inhomogeneity attributed to sediment packing was observed. We expect that after augmentation by acetate, the bacteria will metabolically reduce Fe(III) to Fe(II), leading to significant Tc-99m binding. Imaging sediment columns using nuclear medicine techniques has many attractive features. Trace quantities of the radiolabeled compounds are used (micro- to nano- molar) and the half-lives of many of these tracers are short (Image of Tc-99m distribution in a column containing Rifle sediment at four times.

  8. Thermally stable dexsil-400 glass capillary columns

    International Nuclear Information System (INIS)

    Maskarinec, M.P.; Olerich, G.

    1980-01-01

    The factors affecting efficiency, thermal stability, and reproducibility of Dexsil-400 glass capillary columns for gas chromatography in general, and for polycyclic aromatic hydrocarbons (PAHs) in particular were investigated. Columns were drawn from Kimble KG-6 (soda-lime) glass or Kimox (borosilicate) glass. All silylation was carried out at 200 0 C. Columns were coated according to the static method. Freshly prepared, degassed solutions of Dexsil-400 in pentane or methylene chloride were used. Thermal stability of the Dexsil 400 columns with respect to gas chromatography/mass spectrometry (GC/MS) were tested. Column-to-column variability is a function of each step in the fabrication of the columns. The degree of etching, extent of silylation, and stationary phase film thickness must be carefully controlled. The variability in two Dexsil-400 capillary column prepared by etching, silylation with solution of hexa methyl disilazone (HMDS), and static coating is shown and also indicates the excellent selectivity of Dexsil-400 for the separation of alkylated aromatic compounds. The wide temperature range of Dexsil-400 and the high efficiency of the capillary columns also allow the analysis of complex mixtures with minimal prefractionation. Direct injection of a coal liquefaction product is given. Analysis by GC/MS indicated the presence of parent PAHs, alkylated PAHs, nitrogen and sulfur heterocycles, and their alkylated derivatives. 4 figures

  9. Safety barriers and lighting columns.

    NARCIS (Netherlands)

    Schreuder, D.A.

    1972-01-01

    Problems arising from the sitting of lighting columns on the central reserve are reviewed, and remedial measures such as break-away lighting supports and installation of safety fences on the central reserve on both sides of the lighting columns are examined.

  10. Heat Transfer Analysis for a Fixed CST Column

    International Nuclear Information System (INIS)

    Lee, S.Y.

    2004-01-01

    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

  11. NON-LINEAR ANALYSIS OF AN EXPERIMENTAL JOINT OF COLUMN AND BEAMS OF ARMED CONCRETE-STEEL COLUMN FOR FRAME

    Directory of Open Access Journals (Sweden)

    Nelson López

    2017-12-01

    Full Text Available In this research, the nonlinear behavior of a real-scale experimental joint (node is studied, consisting of three reinforced concrete elements, one column and two beams joined to a structural steel column at the upper level. In the numerical analysis the model of the union was analyzed in the inelastic range, this model was elaborated with the finite element program based on fibers, SeismoStruct to analyze as a function of time, the traction and compression efforts in the confined area and not confined area of the concrete column and in the longitudinal reinforcement steel, as well as verification of the design of the base plate that joins the two columns. The results showed that tensile stresses in the unconfined zone surpassed the concrete breaking point, with cracking occurring just below the lower edge of the beams; in the confined area the traction efforts were much lower, with cracks occurring later than in the non-confined area. The concrete column-steel column joint behaved as a rigid node, so the elastic design was consistent with the calculation methodology of base plates for steel columns.

  12. Fabrication of a micrometer Ni–Cu alloy column coupled with a Cu micro-column for thermal measurement

    International Nuclear Information System (INIS)

    Lin, J C; Chang, T K; Yang, J H; Jeng, J H; Lee, D L; Jiang, S B

    2009-01-01

    Micrometer Ni–Cu alloy columns have been fabricated by the micro-anode-guided electroplating (MAGE) process in the citrate bath. The surface morphology and chemical composition of the micro-columns were determined by copper concentration in the bath and by the electrical bias of MAGE. When fabricated in a bath of dilute copper (i.e. 4 mM) at lower voltages (e.g. 3.8 and 4.0 V), the alloy micro-columns revealed uniform diameter and smooth appearance. The alloy composition demonstrated an increase in the wt% ratio of Ni/Cu from 75/25, 80/20, 83/17 to 87/13 with increasing electrical bias from 3.8, 4.0, 4.2 to 4.4 V. However, it decreases from 75/25, 57/43 to 47/53 with increasing copper concentration from 4, 8 to 12 mM in the bath. Citrate plays a role in forming complexes with nickel and copper at similar reduction potentials, thus reducing simultaneously to Ni–Cu alloy. The mechanism for fabricating alloy micro-columns could be delineated on the basis of cathodic polarization of the complexes. A couple of micro-columns were fabricated using MAGE in constructing a pure copper micro-column on the top of a Ni/Cu (at 47/53) alloy micro-column. This micro-thermocouple provides a satisfactory measurement with good sensitivity and precision

  13. 29 CFR 1926.755 - Column anchorage.

    Science.gov (United States)

    2010-07-01

    ... 29 Labor 8 2010-07-01 2010-07-01 false Column anchorage. 1926.755 Section 1926.755 Labor... (CONTINUED) SAFETY AND HEALTH REGULATIONS FOR CONSTRUCTION Steel Erection § 1926.755 Column anchorage. (a) General requirements for erection stability. (1) All columns shall be anchored by a minimum of 4 anchor...

  14. Mapping of the left-sided phrenic nerve course in patients undergoing left atrial catheter ablations.

    Science.gov (United States)

    Huemer, Martin; Wutzler, Alexander; Parwani, Abdul S; Attanasio, Philipp; Haverkamp, Wilhelm; Boldt, Leif-Hendrik

    2014-09-01

    Catheter ablation of atrial fibrillation has been associated with left-sided phrenic nerve palsy. Knowledge of the individual left phrenic nerve course therefore is essential to prevent nerve injury. The aim of this study was to test the feasibility of an intraprocedural pace mapping and reconstruction of the left phrenic nerve course and to characterize which anatomical areas are affected. In patients undergoing left atrial catheter ablation, a three-dimensional map of the left atrial anatomical structures was created. The left-sided phrenic nerve course was determined by high-output pace mapping and reconstructed in the map. In this study, 40 patients with atrial fibrillation or atrial tachycardias were included. Left phrenic nerve capture was observed in 23 (57.5%) patients. Phrenic nerve was captured in 22 (55%) patients inside the left atrial appendage, in 22 (55%) in distal parts, in 21 (53%) in medial parts, and in two (5%) in ostial parts of the appendage. In three (7.5%) patients, capture was found in the distal coronary sinus and in one (2.5%) patient in the left atrium near the left atrial appendage ostium. Ablation target was changed due to direct spatial relationship to the phrenic nerve in three (7.5%) patients. No phrenic nerve palsy was observed. Left-sided phrenic nerve capture was found inside and around the left atrial appendage in the majority of patients and additionally in the distal coronary sinus. Phrenic nerve mapping and reconstruction can easily be performed and should be considered prior catheter ablations in potential affected areas. ©2014 Wiley Periodicals, Inc.

  15. Behavior of reinforced concrete columns strenghtened by partial jacketing

    Directory of Open Access Journals (Sweden)

    D. B. FERREIRA

    Full Text Available This article presents the study of reinforced concrete columns strengthened using a partial jacket consisting of a 35mm self-compacting concrete layer added to its most compressed face and tested in combined compression and uniaxial bending until rupture. Wedge bolt connectors were used to increase bond at the interface between the two concrete layers of different ages. Seven 2000 mm long columns were tested. Two columns were cast monolithically and named PO (original column e PR (reference column. The other five columns were strengthened using a new 35 mm thick self-compacting concrete layer attached to the column face subjected to highest compressive stresses. Column PO had a 120mm by 250 mm rectangular cross section and other columns had a 155 mm by 250mm cross section after the strengthening procedure. Results show that the ultimate resistance of the strengthened columns was more than three times the ultimate resistance of the original column PO, indicating the effectiveness of the strengthening procedure. Detachment of the new concrete layer with concrete crushing and steel yielding occurred in the strengthened columns.

  16. Influence of porewater advection on denitrification in carbonate sands: Evidence from repacked sediment column experiments

    DEFF Research Database (Denmark)

    Santos, Isaac R.; Eyre, Bradley D.; Glud, Ronnie N.

    2012-01-01

    Porewater flow enhances mineralization rates in organic-poor permeable sands. Here, a series of sediment column experiments were undertaken to assess the potential effect of advective porewater transport on denitrification in permeable carbonate sands collected from Heron Island (Great Barrier Re...

  17. Topography of the accessory left gastric artery (ALGA) analyzed by CT angiography from the left hepatic artery

    International Nuclear Information System (INIS)

    Shioyama, Yasukazu; Takasaka, Isao; Onaya, Hiroaki

    2003-01-01

    To avoid gastric complications when we perform transcatheter treatment via left hepatic artery, we analyzed the topography of ALGA (accessory left gastric artery) by left hepatic arteriography and CT angiography from left hepatic artery. Six hundred seventy eight cases of CT angiography were performed between 1995 and 2000. Among them, selective left hepatic arteriography was done in 85 cases. We analyzed the frequency and the course of ALGA on the hepatic angiogram and CT angiogram. ALGA were identified in eighteen (21.2 %) of the 85 cases. We classified them into eleven cases of the proximal type and six cases of the distal type. When ALGA bifurcated from the left hepatic artery very close to the bifurcation of A2 (dorsolateral branch) and A3 (ventrolateral branch), we classified them as the distal type on hepatic angiogram. On the other hand, when ALGA bifurcated from the left hepatic artery apart from the bifurcation of A2 and A3 they were classified as the proximal type. In one rare case ALGA originated from the dorsolateral branch of the left hepatic artery. ALGA were classified as the distal and proximal types. Distal type of ALGA often overlapped dorsolateral branch of the left hepatic artery, and it was sometimes difficult to notice the existence of them. We should check the existence of ALGA on the arterial phase of dynamic CT before we plan to make a transcatheter treatment from the left hepatic artery. Then we can avoid gastric complications caused by a transcatheter treatment from the left hepatic artery. (author)

  18. Why Dora Left

    DEFF Research Database (Denmark)

    Gammelgård, Judy

    2017-01-01

    The question of why Dora left her treatment before it was brought to a satisfactory end and the equally important question of why Freud chose to publish this problematic and fragmentary story have both been dealt with at great length by Freud’s successors. Dora has been read by analysts, literary...... problem toward femininity, both Dora’s and his own. In Dora, it is argued, Freud took a new stance toward the object of his investigation, speaking from the position of the master. Freud presents himself as the one who knows, in great contrast to the position he takes when unraveling the dream. Here he...

  19. Associations between the Cervical Vertebral Column and Craniofacial Morphology

    DEFF Research Database (Denmark)

    Sonnesen, Ane Liselotte

    2010-01-01

    Aim. To summarize recent studies on morphological deviations of the cervical vertebral column and associations with craniofacial morphology and head posture in nonsyndromic patients and in patients with obstructive sleep apnoea (OSA). Design. In these recent studies, visual assessment of the cerv......Aim. To summarize recent studies on morphological deviations of the cervical vertebral column and associations with craniofacial morphology and head posture in nonsyndromic patients and in patients with obstructive sleep apnoea (OSA). Design. In these recent studies, visual assessment...... of the cervical vertebral column and cephalometric analysis of the craniofacial skeleton were performed on profile radiographs of subjects with neutral occlusion, patients with severe skeletal malocclusions and patients with OSA. Material from human triploid foetuses and mouse embryos was analysed histologically....... Results. Recent studies have documented associations between fusion of the cervical vertebral column and craniofacial morphology, including head posture in patients with severe skeletal malocclusions. Histological studies on prenatal material supported these findings. Conclusion. It is suggested...

  20. Water table fluctuations and soil biogeochemistry: An experimental approach using an automated soil column system

    Science.gov (United States)

    Rezanezhad, F.; Couture, R.-M.; Kovac, R.; O'Connell, D.; Van Cappellen, P.

    2014-02-01

    Water table fluctuations significantly affect the biological and geochemical functioning of soils. Here, we introduce an automated soil column system in which the water table regime is imposed using a computer-controlled, multi-channel pump connected to a hydrostatic equilibrium reservoir and a water storage reservoir. The potential of this new system is illustrated by comparing results from two columns filled with 45 cm of the same homogenized riparian soil. In one soil column the water table remained constant at -20 cm below the soil surface, while in the other the water table oscillated between the soil surface and the bottom of the column, at a rate of 4.8 cm d-1. The experiment ran for 75 days at room temperature (25 ± 2 °C). Micro-sensors installed at -10 and -30 cm below the soil surface in the stable water table column recorded constant redox potentials on the order of 600 and -200 mV, respectively. In the fluctuating water table column, redox potentials at the same depths oscillated between oxidizing (∼700 mV) and reducing (∼-100 mV) conditions. Pore waters collected periodically and solid-phase analyses on core material obtained at the end of the experiment highlighted striking geochemical differences between the two columns, especially in the time series and depth distributions of Fe, Mn, K, P and S. Soil CO2 emissions derived from headspace gas analysis exhibited periodic variations in the fluctuating water table column, with peak values during water table drawdown. Transient redox conditions caused by the water table fluctuations enhanced microbial oxidation of soil organic matter, resulting in a pronounced depletion of particulate organic carbon in the midsection of the fluctuating water table column. Denaturing Gradient Gel Electrophoresis (DGGE) revealed the onset of differentiation of the bacterial communities in the upper (oxidizing) and lower (reducing) soil sections, although no systematic differences in microbial community structure

  1. [Autopsy case of Lissauer's general paresis with rapidly progressive left hemiparesis].

    Science.gov (United States)

    Kato, Hiroko; Yoshida, Mari; Ando, Tetsuo; Sugiura, Makoto; Hashizume, Yoshio

    2009-06-01

    A 48-years-old man presented with slowly progressive bradykinesia, personality change and rapidly progressive left hemiparesis. On admission, he presented dementia, poor judgment, left hemiparesis. MRI revealed a widespread high intensity area in right hemisphere and MRA was almost normal. Serological tests of serum and CSF demonstrated high titers of antibodies to Treponema pallidum. He was treated for syphilis with daily penicillin injections without improvement. He died of sepsis eight months after admission. At autopsy, the brain weighed 1,100 g and the right cerebral hemisphere was atrophic, especially in frontal base, temporal, parietal, angular, and posterior regions covered by thickened, fibrotic leptomeninges. Microscopically, chronic meningoencephalitis was observed. Severe neuronal loss with gliosis was seen in the right cerebral cortices. Scattered rod-shaped microglia and inflammatory cell infiltration were visible in the cerebral parenchyma. The dorsal column of the spinal cord was not involved and meningovascular syphilis was unclear. The distribution of the encephalitic lesions was well correlated with the clinical and neuroradiological findings. This was a rare autopsy case presenting Lissauer's general paresis, clinically manifesting as rapidly progressive stroke-like episode.

  2. Chromatographic properties PLOT multicapillary columns.

    Science.gov (United States)

    Nikolaeva, O A; Patrushev, Y V; Sidelnikov, V N

    2017-03-10

    Multicapillary columns (MCCs) for gas chromatography make it possible to perform high-speed analysis of the mixtures of gaseous and volatile substances at a relatively large amount of the loaded sample. The study was performed using PLOT MCCs for gas-solid chromatography (GSC) with different stationary phases (SP) based on alumina, silica and poly-(1-trimethylsilyl-1-propyne) (PTMSP) polymer as well as porous polymers divinylbenzene-styrene (DVB-St), divinylbenzene-vinylimidazole (DVB-VIm) and divinylbenzene-ethylene glycol dimethacrylate (DVB-EGD). These MCCs have the efficiency of 4000-10000 theoretical plates per meter (TP/m) and at a column length of 25-30cm can separate within 10-20s multicomponent mixtures of substances belonging to different classes of chemical compounds. The sample amount not overloading the column is 0.03-1μg and depends on the features of a porous layer. Examples of separations on some of the studied columns are considered. Copyright © 2017 Elsevier B.V. All rights reserved.

  3. Lighting columns. Research on the behaviour of lighting columns in sideways- on and head-on impact tests with private cars.

    NARCIS (Netherlands)

    1978-01-01

    Lighting columns can be made more safe by providing them with a sliding construction. This construction makes it possible that the column slides from his ground construction in case of an accident. Aluminium lighting can be constructed in such a way that the break off in case of a car collides

  4. Gravity Effects on the Free Vibration of a Graphite Column

    International Nuclear Information System (INIS)

    Ki, Dong-Ok; Kim, Jong-Bum; Park, Keun-Bae; Lee, Won-Jae

    2006-01-01

    The gravity effects on the free vibration of a graphite column are studied. Graphite block is a key component of a HTGR (High Temperature Gas Cooled Reactor). The major core elements, such as the fuel blocks and neutron reflector blocks, of HTTR (High Temperature Test Reactor, Japan) and GT-MHR (Gas Turbine- Modular Helium Reactor, USA) consist of stacked hexagonal graphite blocks forming a group of columns. The vibration of the columns induced by earthquakes may lead to solid impacts between graphite blocks and structural integrity problems. The study of free vibration characteristics of the graphite block column is the first step in the core internal structure dynamic analysis. Gravity force bring a negative stiffness term to the transverse vibration analysis of heavy long column structures, and results in natural frequency reductions. Generally it is not considered in the not so tall structure cases, because the gravity term makes the analysis and design complicated. Therefore it is important to check whether the gravity effect is severe or not

  5. Recent advances in column switching sample preparation in bioanalysis.

    Science.gov (United States)

    Kataoka, Hiroyuki; Saito, Keita

    2012-04-01

    Column switching techniques, using two or more stationary phase columns, are useful for trace enrichment and online automated sample preparation. Target fractions from the first column are transferred online to a second column with different properties for further separation. Column switching techniques can be used to determine the analytes in a complex matrix by direct sample injection or by simple sample treatment. Online column switching sample preparation is usually performed in combination with HPLC or capillary electrophoresis. SPE or turbulent flow chromatography using a cartridge column and in-tube solid-phase microextraction using a capillary column have been developed for convenient column switching sample preparation. Furthermore, various micro-/nano-sample preparation devices using new polymer-coating materials have been developed to improve extraction efficiency. This review describes current developments and future trends in novel column switching sample preparation in bioanalysis, focusing on innovative column switching techniques using new extraction devices and materials.

  6. Managed aquifer recharge: the fate of pharmaceuticals from infiltrated treated wastewater investigated through soil column experiments

    Science.gov (United States)

    Silver, Matthew; Selke, Stephanie; Balsaa, Peter; Wefer-Roehl, Annette; Kübeck, Christine; Schüth, Christoph

    2017-04-01

    The EU FP7 project MARSOL addresses water scarcity challenges in arid regions, where managed aquifer recharge (MAR) is an upcoming technology to recharge depleted aquifers using alternative water sources. Within this framework, column experiments were conducted to investigate the fate of pharmaceuticals when secondary treated wastewater (TWW) is infiltrated through a natural soil (organic matter content 6.8%) being considered for MAR. Three parallel experiments were run under conditions of continuous infiltration (one column) and wetting-drying cycles (two columns, with different analytes) over a 16 month time period. The pharmaceuticals diclofenac, ibuprofen, carbamazepine, naproxen, gemfibrozil, and fenoprofen, as well as the antibiotics doxycycline, sulfadimidine, and sulfamethoxazole, are commonly present in treated wastewater in varying concentrations. For the experiments, concentration variability was reduced by spiking the column inflow water with these compounds. Concentrations were periodically analyzed at different depths in each column and the mass passing each depth over the duration of the experiment was calculated. At the end of the experiments, sorbed pharmaceuticals were extracted from soil samples collected from different depths. A pressurized liquid extraction method was developed and resulted in recoveries from spiked post-experiment soil samples ranging from 64% (gemfibrozil) to 82% (carbamazepine) for the six non-antibiotic compounds. Scaling results by these recovery rates, the total mass of pharmaceuticals sorbed to the soil in the columns was calculated and compared to the calculated attenuated mass (i.e. mass that left the water phase). The difference between the attenuated mass and the sorbed mass is considered to be mass that degraded. Results for continuous infiltration conditions indicate that for carbamazepine and diclofenac, sorption is the primary attenuation mechanism, with missing (i.e. degraded) mass lying within the propagated

  7. Operation of the annular pulsed column, (2)

    International Nuclear Information System (INIS)

    Takahashi, Keiki; Tsukada, Takeshi

    1988-01-01

    The heat of reaction generated form the uranium extraction is considered to from the temperature profile inside the pulsed column. A simulation code was developed to estimate the temperature profile, considering heat generation and counter-current heat transfer. The temperature profiles calculated using this code was found to depend on both the position of the extraction zone and the operating condition. The reported experimental result was fairly represented by this simulation code. We consider that this presented simulation code is capable of providing with the temperature profile in the pulsed column and useful for the monitoring of the uranium extraction zone. (author)

  8. Optimization of the bending stiffness of beam-to-column and column-to-foundation connections in precast concrete structures

    Directory of Open Access Journals (Sweden)

    R. R. R. COSTA

    Full Text Available Abstract This work involved the structural optimization of precast concrete rigid frames with semi-rigid beam-to-column connections. To this end, several frames were simulated numerically using the Finite Element Method. Beams and columns were modeled using bar elements and their connections were modeled using spring elements, with variable bending stiffness. The objective function was based on the search of the least stiff connection able to ensure the global stability of the building. Lastly, a connection model with optimal stiffness was adopted to design the frame. Semi-rigid beam-to-column connections with a constraint factors of 0.33 sufficed to ensure the maximum allowable horizontal displacement and bending moment of the connection, with a global stability parameter of 1.12. This confirms that even connections with low constraints generate significant gains from the structural standpoint, without affecting construction and assembly-related aspects.

  9. Topographic shear and the relation of ocular dominance columns to orientation columns in primate and cat visual cortex.

    Science.gov (United States)

    Wood, Richard J.; Schwartz, Eric L.

    1999-03-01

    Shear has been known to exist for many years in the topographic structure of the primary visual cortex, but has received little attention in the modeling literature. Although the topographic map of V1 is largely conformal (i.e. zero shear), several groups have observed topographic shear in the region of the V1/V2 border. Furthermore, shear has also been revealed by anisotropy of cortical magnification factor within a single ocular dominance column. In the present paper, we make a functional hypothesis: the major axis of the topographic shear tensor provides cortical neurons with a preferred direction of orientation tuning. We demonstrate that isotropic neuronal summation of a sheared topographic map, in the presence of additional random shear, can provide the major features of cortical functional architecture with the ocular dominance column system acting as the principal source of the shear tensor. The major principal axis of the shear tensor determines the direction and its eigenvalues the relative strength of cortical orientation preference. This hypothesis is then shown to be qualitatively consistent with a variety of experimental results on cat and monkey orientation column properties obtained from optical recording and from other anatomical and physiological techniques. In addition, we show that a recent result of Das and Gilbert (Das, A., & Gilbert, C. D., 1997. Distortions of visuotopic map match orientation singularities in primary visual cortex. Nature, 387, 594-598) is consistent with an infinite set of parameterized solutions for the cortical map. We exploit this freedom to choose a particular instance of the Das-Gilbert solution set which is consistent with the full range of local spatial structure in V1. These results suggest that further relationships between ocular dominance columns, orientation columns, and local topography may be revealed by experimental testing.

  10. Local connections between the columns of the periaqueductal gray matter: a case for intrinsic neuromodulation.

    Science.gov (United States)

    Jansen, A S; Farkas, E; Mac Sams, J; Loewy, A D

    1998-02-16

    Chemical stimulation of the lateral or ventrolateral columns of the midbrain periaqueductal gray matter (PAG) in conscious animals produces opposite responses (viz., defensive behavior and pressor responses from the lateral column vs. quiescence and depressor responses from the ventrolateral column), raising the possibility that the two columns are interconnected. To test this hypothesis, two types of anatomical experiments were performed in rats. First, the anterograde axonal marker Phaseolus vulgaris leuco-agglutinin (PHA-L) was injected into individual PAG columns or adjoining regions which included the Edinger-Westphal, dorsal raphe, and precommissural nuclei. The results shows that each column projects bilaterally to all of the other PAG columns, and also provides local connections within its own column. Furthermore, the Edinger-Westphal and precommissural nuclei project to all four PAG columns, while the dorsal raphe nucleus projects only to the ventrolateral and lateral columns. In a second experiment, we found that cardiovascular-related PAG projection neurons of both the lateral and ventrolateral columns receive an input from the reciprocal PAG column. This was demonstrated by a double tracer neuroanatomical study in which PHA-L was first iontophoretically ejected into either the lateral or ventrolateral PAG columns and then, several days later the retrograde transneuronal viral tracer, pseudorabies virus, was injected into the stellate sympathetic ganglion. Intra-PAG circuits were visualized by a dual immunohistochemical procedure. These results suggest that during the fight-or-flight response when the 'fight' program is activated, inhibition of the 'flight' PAG network may occur and the converse situation may occur during the flight response. Copyright 1997 Elsevier Science B.V.

  11. Left-right compatibility in the processing of trading verbs.

    Science.gov (United States)

    Vicario, Carmelo M; Rumiati, Raffaella I

    2014-01-01

    The research investigating the nature of cognitive processes involved in the representation of economical outcomes is growing. Within this research, the mental accounting model proposes that individuals may well use cognitive operations to organize, evaluate, and keep track of their financial activities (Thaler, 1999). Here we wanted to test this hypothesis by asking to a group of participants to detect a syntax mistake of verbs indicating incoming and going out activities related to economical profit (trading verbs), swapping (swapping verbs) and thinking (thinking verbs). We reported a left-right compatibility for trading verbs (i.e., participants were faster with their right hand while detecting verb referring to a monetary gain with respect to a monetary loss; and faster with their left hand while detecting a monetary loss with respect to a monetary gain). However, this pattern of result was not reported while detecting swapping verbs. Results are discussed taking into account the mental accounting theory as well as to the spatial mapping of valence hypothesis.

  12. Influence of the column rectangularity index and of the boundary conditions in the punching resistance of slab-column connections

    Directory of Open Access Journals (Sweden)

    O. S. PAIVA

    Full Text Available Experimental evidence indicates that both the column rectangularity index and the boundary conditions of the connection may affect the ultimate punching resistance. This paper presents general aspects of these topics and, through the analysis of experimental results of tests on 131 slabs, evaluates the accuracy and suitability of recommendations presented by ABNT NBR 6118, Eurocode 2, ACI 318 and fib Model Code 2010. Experimental results showed that the security level of normative estimates trend to reduce as the column rectangularity increases, and in some cases, the punching resistance was overestimated. Finally, adjustments are suggested in equations presented by NBR 6118 and MC2010 in order to eliminate this trend of unsafe results.

  13. Locating karst depressed columns by means of Rn measurement on the surface

    International Nuclear Information System (INIS)

    Tang Daimao; Liu Hongfu; Duan Hongjie; Duan Lindi; Sui Haichen

    1999-01-01

    The coal mining and the related surface projects are extremely harassed by the underground karst depressed columns. The author discussed the surface Rn concentration's abnormality caused by the karst depressed columns. It is concluded that different kinds of karst depressed column can cause different Rn concentration's abnormality. The α-cup Rn measuring instrument was used for detecting Rn abnormality on the surface in order to locate the underground karst depressed columns

  14. PRTR ion exchange vault column sampling

    International Nuclear Information System (INIS)

    Cornwell, B.C.

    1995-01-01

    This report documents ion exchange column sampling and Non Destructive Assay (NDA) results from activities in 1994, for the Plutonium Recycle Test Reactor (PRTR) ion exchange vault. The objective was to obtain sufficient information to prepare disposal documentation for the ion exchange columns found in the PRTR Ion exchange vault. This activity also allowed for the monitoring of the liquid level in the lower vault. The sampling activity contained five separate activities: (1) Sampling an ion exchange column and analyzing the ion exchange media for purpose of waste disposal; (2) Gamma and neutron NDA testing on ion exchange columns located in the upper vault; (3) Lower vault liquid level measurement; (4) Radiological survey of the upper vault; and (5) Secure the vault pending waste disposal

  15. Laser surface wakefield in a plasma column

    International Nuclear Information System (INIS)

    Gorbunov, L.M.; Mora, P.; Ramazashvili, R.R.

    2003-01-01

    The structure of the wakefield in a plasma column, produced by a short intense laser pulse, propagating through a gas affected by tunneling ionization is investigated. It is shown that besides the usual plasma waves in the bulk part of the plasma column [see Andreev et al., Phys. Plasmas 9, 3999 (2002)], the laser pulse also generates electromagnetic surface waves propagating along the column boundary. The length of the surface wake wave substantially exceeds the length of the plasma wake wave and its electromagnetic field extends far outside the plasma column

  16. Left insular cortex and left SFG underlie prismatic adaptation effects on time perception: evidence from fMRI.

    Science.gov (United States)

    Magnani, Barbara; Frassinetti, Francesca; Ditye, Thomas; Oliveri, Massimiliano; Costantini, Marcello; Walsh, Vincent

    2014-05-15

    Prismatic adaptation (PA) has been shown to affect left-to-right spatial representations of temporal durations. A leftward aftereffect usually distorts time representation toward an underestimation, while rightward aftereffect usually results in an overestimation of temporal durations. Here, we used functional magnetic resonance imaging (fMRI) to study the neural mechanisms that underlie PA effects on time perception. Additionally, we investigated whether the effect of PA on time is transient or stable and, in the case of stability, which cortical areas are responsible of its maintenance. Functional brain images were acquired while participants (n=17) performed a time reproduction task and a control-task before, immediately after and 30 min after PA inducing a leftward aftereffect, administered outside the scanner. The leftward aftereffect induced an underestimation of time intervals that lasted for at least 30 min. The left anterior insula and the left superior frontal gyrus showed increased functional activation immediately after versus before PA in the time versus the control-task, suggesting these brain areas to be involved in the executive spatial manipulation of the representation of time. The left middle frontal gyrus showed an increase of activation after 30 min with respect to before PA. This suggests that this brain region may play a key role in the maintenance of the PA effect over time. Copyright © 2014. Published by Elsevier Inc.

  17. Field Applications of Gamma Column Scanning Technology

    International Nuclear Information System (INIS)

    Aquino, Denis D.; Mallilin, Janice P.; Nuñez, Ivy Angelica A.; Bulos, Adelina DM.

    2015-01-01

    The Isotope Techniques Section (ITS) under the Nuclear Service Division (NSD) of the Philippine Nuclear Research Institute (PNRI) conducts services, research and development on radioisotope and sealed source application in the industry. This aims to benefit the manufacturing industries such as petroleum, petrochemical, chemical, energy, waste, column treatment plant, etc. through on line inspection and troubleshooting of a process vessel, column or pipe that could optimize the process operation and increase production efficiency. One of the most common sealed source techniques for industrial applications is the gamma column scanning technology. Gamma column scanning technology is an established technique for inspection, analysis and diagnosis of industrial columns for process optimization, solving operational malfunctions and management of resources. It is a convenient non-intrusive, cost effective and cost-efficient technique to examine inner details of an industrial process vessel such as a distillation column while it is in operation. The Philippine Nuclear Research Institute (PNRI) recognize the importance and benefits of this technology and has implemented activities to make gamma column scanning locally available to benefit the Philippine industries. Continuous effort for capacity building is being pursued thru the implementation of in-house and on-the-job training abroad and upgrading of equipment. (author)

  18. Optimization of the isotope separation in columns

    International Nuclear Information System (INIS)

    Kaminskij, V.A.; Vetsko, V.M.; Tevzadze, G.A.; Devdariani, O.A.; Sulaberidze, G.A.

    1982-01-01

    The general method for the multi-parameter optimization of cascade plants of packed columns is proposed. As an optimization effectiveness function a netcost of the isotopic product is selected. The net cost is comprehensively characterizing the sum total of capital costs for manufacturing the products as well as determining the choice of the most effective directions for capital investments and rational limits of improvement of the products quality. The method is based on main representations of the cascade theory, such as the ideal flow profile and form efficiency as well as mathematical model of the packed column specifying the bonds between its geometric and operating parameters. As a result, the isotopic products cost function could be bound with such parameters as the equilibrium stage height, ultimate packing capacity, its element dimensions, column diameter. It is concluded that the suggested approach to the optimization of isotope separation processes is rather a general one. It permits to solve a number of special problems, such as estimation of advisability of using heat-pump circuits and determining the rational automation level. Besides, by means of the method suggested one can optimize the process conditions with regard to temperature and pressure

  19. The employment of cellulose pressure columns for the chromatographic separation of radioactive nuclides

    International Nuclear Information System (INIS)

    Meier, H.; Zimmerhackl, E.; Unger, E.; Zeitler, G.; Albrecht, W.; Boesche, D.; Hecker, W.; Menge, P.

    1975-01-01

    A study was made of the separation properties of cellulose pressure columns operating at a slight over-pressure of around 1 atmosphere, with respect to the length of the column packing, the flow rate, and the load. The optimal separation stage heights of the columns are situated at H=0.16 mm. Since as a consequence of the favorable separation stage heights observed at column lengths of 3 to 7 cm, separation stage numbers of 200 to 400 are attained, and hence it is possible to attain separations within several minutes with flow rates of 1 ml/min. The choice of the mobile phase is made easier by the fact that paper chromatographic Rsub(f)-values can be transferred to the cellulose pressure column with the aid of a transfer function. (author)

  20. Dorsal column sensory axons degenerate due to impaired microvascular perfusion after spinal cord injury in rats

    Science.gov (United States)

    Muradov, Johongir M.; Ewan, Eric E.; Hagg, Theo

    2013-01-01

    The mechanisms contributing to axon loss after spinal cord injury (SCI) are largely unknown but may involve microvascular loss as we have previously suggested. Here, we used a mild contusive injury (120 kdyn IH impactor) at T9 in rats focusing on ascending primary sensory dorsal column axons, anterogradely traced from the sciatic nerves. The injury caused a rapid and progressive loss of dorsal column microvasculature and oligodendrocytes at the injury site and penumbra and a ~70% loss of the sensory axons, by 24 hours. To model the microvascular loss, focal ischemia of the T9 dorsal columns was achieved via phototoxic activation of intravenously injected rose bengal. This caused an ~53% loss of sensory axons and an ~80% loss of dorsal column oligodendrocytes by 24 hours. Axon loss correlated with the extent and axial length of microvessel and oligodendrocyte loss along the dorsal column. To determine if oligodendrocyte loss contributes to axon loss, the glial toxin ethidium bromide (EB; 0.3 µg/µl) was microinjected into the T9 dorsal columns, and resulted in an ~88% loss of dorsal column oligodendrocytes and an ~56% loss of sensory axons after 72 hours. EB also caused an ~72% loss of microvessels. Lower concentrations of EB resulted in less axon, oligodendrocyte and microvessel loss, which were highly correlated (R2 = 0.81). These data suggest that focal spinal cord ischemia causes both oligodendrocyte and axon degeneration, which are perhaps linked. Importantly, they highlight the need of limiting the penumbral spread of ischemia and oligodendrocyte loss after SCI in order to protect axons. PMID:23978615

  1. A Left-Hand Rule for Faraday's Law

    Science.gov (United States)

    Salu, Yehuda

    2014-01-01

    A left-hand rule for Faraday's law is presented here. This rule provides a simple and quick way of finding directional relationships between variables of Faraday's law without using Lenz's rule.

  2. Picobubble enhanced column flotation of fine coal

    Energy Technology Data Exchange (ETDEWEB)

    Tao, D.; Yu, S.; Parekh, B.K. [University of Kentucky, Lexington, KY (United States). Mining Engineering

    2006-07-01

    The purpose is to study the effectiveness of picobubbles in the column flotation of -28 mesh fine coal particles. A flotation column with a picobubble generator was developed and tested for enhancing the recovery of ultrafine coal particles. The picobubble generator was designed using the hydrodynamic cavitation principle. A metallurgical and a steam coal were tested in the apparatus. The results show that the use of picobubbles in a 2in. flotation column increased the recovery of fine coal by 10 to 30%. The recovery rate varied with feed rate, collector dosage, and other column conditions. 40 refs., 8 figs., 2 tabs.

  3. Built for speed: strain in the cartilaginous vertebral columns of sharks.

    Science.gov (United States)

    Porter, M E; Diaz, Candido; Sturm, Joshua J; Grotmol, Sindre; Summers, A P; Long, John H

    2014-02-01

    In most bony fishes vertebral column strain during locomotion is almost exclusively in the intervertebral joints, and when these joints move there is the potential to store and release strain energy. Since cartilaginous fishes have poorly mineralized vertebral centra, we tested whether the vertebral bodies undergo substantial strain and thus may be sites of energy storage during locomotion. We measured axial strains of the intervertebral joints and vertebrae in vivo and ex vivo to characterize the dynamic behavior of the vertebral column. We used sonomicrometry to directly measure in vivo and in situ strains of intervertebral joints and vertebrae of Squalus acanthias swimming in a flume. For ex vivo measurements, we used a materials testing system to dynamically bend segments of vertebral column at frequencies ranging from 0.25 to 1.00 Hz and a range of physiologically relevant curvatures, which were determined using a kinematic analysis. The vertebral centra of S. acanthias undergo strain during in vivo volitional movements as well as in situ passive movements. Moreover, when isolated segments of vertebral column were tested during mechanical bending, we measured the same magnitudes of strain. These data support our hypothesis that vertebral column strain in lateral bending is not limited to the intervertebral joints. In histological sections, we found that the vertebral column of S. acanthias has an intracentral canal that is open and covered with a velum layer. An open intracentral canal may indicate that the centra are acting as tunics around some sections of a hydrostat, effectively stiffening the vertebral column. These data suggest that the entire vertebral column of sharks, both joints and centra, is mechanically engaged as a dynamic spring during locomotion. Copyright © 2013 Elsevier GmbH. All rights reserved.

  4. [Online enrichment ability of restricted-access column coupled with high performance liquid chromatography by column switching technique for benazepril hydrochloride].

    Science.gov (United States)

    Zhang, Xiaohui; Wang, Rong; Xie, Hua; Yin, Qiang; Li, Xiaoyun; Jia, Zhengping; Wu, Xiaoyu; Zhang, Juanhong; Li, Wenbin

    2013-05-01

    The online enrichment ability of the restricted-access media (RAM) column coupled with high performance liquid chromatography by column switching technique for benazepril hydrochloride in plasma was studied. The RAM-HPLC system consisted of an RAM column as enrichment column and a C18 column as analytical column coupled via the column switching technique. The effects of the injection volume on the peak area and the systematic pressure were studied. When the injection volume was less than 100 microL, the peak area increased with the increase of the injection volume. However, when the injection volume was more than 80 microL, the pressure of whole system increased obviously. In order to protect the whole system, 80 microL was chosen as the maximum injection volume. The peak areas of ordinary injection and the large volume injection showed a good linear relationship. The enrichment ability of RAM-HPLC system was satisfactory. The system was successfully used for the separation and detection of the trace benazepril hydrochloride in rat plasma after its administration. The sensitivity of HPLC can be improved by RAM pre-enrichment. It is a simple and economic measurement method.

  5. Isotopes accumulation in the thermal column of TRIGA reactor

    International Nuclear Information System (INIS)

    Iorgulis, C.; Diaconu, D.; Gugiu, D.; Csaba, R.

    2013-01-01

    The correlation of impurity observed in the virgin graphite and radionuclide content and activities measured in the irradiated graphite needs to know the irradiated history. This is a challenging process if impurity content and irradiation conditions are not accurately known. This is the case of the irradiated graphite in the thermal column of Institute for Nuclear Research Pitesti (INR)14 MW TRIGA reactor. To overcome incomplete impurity content and the unknown position in the column of the measured irradiated graphite available for characterisation and comparison, a set of preliminary simulations were performed. Following Eu 152 /Eu 154 ration they allowed the estimation of an impurity content and irradiation conditions leading to measured activities. Based on these data the radio-isotope accumulation in different positions in the thermal column was predicted. Modelling performed by INR used advanced prediction packages (e.g. WIMS, MCNP ORIGEN-S from Scale 5) to assess the isotopic content of MTR graphite types with irradiation history specific for a TRIGA research reactor. Some certain calculations points from the column were selected in order to model the burnup and isotopes productions using ORIGEN from SCALE code system. (authors)

  6. Comparison of the release of constituents from granular materials under batch and column testing.

    Science.gov (United States)

    Lopez Meza, Sarynna; Garrabrants, Andrew C; van der Sloot, Hans; Kosson, David S

    2008-01-01

    Column leaching testing can be considered a better basis for assessing field impact data than any other available batch test method and thus provides a fundamental basis from which to estimate constituent release under a variety of field conditions. However, column testing is time-intensive compared to the more simplified batch testing, and may not always be a viable option when making decisions for material reuse. Batch tests are used most frequently as a simple tool for compliance or quality control reasons. Therefore, it is important to compare the release that occurs under batch and column testing, and establish conservative interpretation protocols for extrapolation from batch data when column data are not available. Five different materials (concrete, construction debris, aluminum recycling residue, coal fly ash and bottom ash) were evaluated via batch and column testing, including different column flow regimes (continuously saturated and intermittent unsaturated flow). Constituent release data from batch and column tests were compared. Results showed no significant difference between the column flow regimes when constituent release data from batch and column tests were compared. In most cases batch and column testing agreed when presented in the form of cumulative release. For arsenic in carbonated materials, however, batch testing underestimates the column constituent release for most LS ratios and also on a cumulative basis. For cases when As is a constituent of concern, column testing may be required.

  7. Localized giant cell tumors in the spinal column radiologic presentation

    International Nuclear Information System (INIS)

    Fernandez Echeverria, M.A.; Parra Blanco, J.A.; Pagola Serrano, M.A.; Mellado Santos, J.M.; Bueno Lopez, J.; Gonzalez Tutor, A.

    1994-01-01

    Given the uncommonness of the location of giant cell tumors (GCT) in the spinal column and the limited number of studies published, we present a case of GCT located in the spinal column, which involved both vertebral bodies and partially destroyed the adjacent rib. (Author)

  8. Response of steel box columns in fire conditions

    Directory of Open Access Journals (Sweden)

    Mahmood Yahyai

    2017-05-01

    Full Text Available Effect of elevated temperatures on the mechanical properties of steel, brings the importance of investigating the effect of fire on the steel structures anxiously. Columns, as the main load-carrying part of a structure, can be highly vulnerable to the fire. In this study, the behavior of steel gravity columns with box cross section exposed to fire has been investigated. These kinds of columns are widely used in common steel structures design in Iran. In current study, the behavior of such columns in fire conditions is investigated through the finite element method. To perform this, the finite element model of a steel column which has been previously tested under fire condition, was prepared. Experimental loading and boundary conditions were considered in the model and was analyzed. Results were validated by experimental data and various specimens of gravity box columns were designed according to the Iran’s steel buildings code, and modeled and analyzed using Abaqus software. The effect of width to thickness ratio of column plates, the load ratio and slenderness on the ultimate strength of the column was investigated, and the endurance time was estimated under ISO 834 standard fire curve. The results revealed that an increase in width to thickness ratio and load ratio leads to reduction of endurance time and the effect of width to thickness ratio on the ultimate strength of the column decreases with temperature increase.

  9. Retrofit of distillation columns in biodiesel production plants

    International Nuclear Information System (INIS)

    Nguyen, Nghi; Demirel, Yasar

    2010-01-01

    Column grand composite curves and the exergy loss profiles produced by the Column-Targeting Tool of the Aspen Plus simulator are used to assess the performance of the existing distillation columns, and reduce the costs of operation by appropriate retrofits in a biodiesel production plant. Effectiveness of the retrofits is assessed by means of thermodynamics and economic improvements. We have considered a biodiesel plant utilizing three distillation columns to purify biodiesel (fatty acid methyl ester) and byproduct glycerol as well as reduce the waste. The assessments of the base case simulation have indicated the need for modifications for the distillation columns. For column T202, the retrofits consisting of a feed preheating and reflux ratio modification have reduced the total exergy loss by 47%, while T301 and T302 columns exergy losses decreased by 61% and 52%, respectively. After the retrofits, the overall exergy loss for the three columns has decreased from 7491.86 kW to 3627.97 kW. The retrofits required a fixed capital cost of approximately $239,900 and saved approximately $1,900,000/year worth of electricity. The retrofits have reduced the consumption of energy considerably, and leaded to a more environmentally friendly operation for the biodiesel plant considered.

  10. Thermodynamic evaluation of distillation columns using exergy loss profiles: a case study on the crude oil atmospheric distillation column

    Energy Technology Data Exchange (ETDEWEB)

    Tarighaleslami, Amir Hossein [Mahshahr Branch, Islamic Azad University, Chemical Engineering Faculty, Mahshar, Khouzestan (Iran, Islamic Republic of); Omidkhah, Mohammad Reza [Tarbiat Modares University, Chemical Engineering Department, Faculty of Engineering, Tehran (Iran, Islamic Republic of); Ghannadzadeh, Ali [University of Toulouse, Department of Process and System Engineering, Chemical Engineering Laboratory, Toulouse (France); Hoseinzadeh Hesas, Roozbeh [University of Malaya, Chemical Engineering Department, Faculty of Engineering, Kuala Lumpur (Malaysia)

    2012-06-15

    This paper presents a case study on the crude oil atmospheric distillation column of Tabriz refinery plant to show the applicability of exergy loss profiles in thermodynamic examination of the different retrofit options. The atmospheric distillation column of Tabriz refinery has been revamped as a consequence of increase of the plant capacity to 100,000 bpd. To cover the deficit of feedstock of the revamped unit, a blend of the existing feedstock with imported crude oil is used as a feedstock. However, to investigate how the blend of these two different types of crudes as a feedstock has an influence on the operating conditions, the examination of the column is needed. Exergy as a comprehensive thermodynamic property which translates the temperature, pressure and composition change into a common unit has been chosen to evaluate the distillation column thermodynamically. Furthermore, the exergy loss profile of the base case serves as a scoping tool to pinpoint the source of inefficiencies. Then, the exergy loss profile as a screening tool has found the retrofit options which are likely to yield greatest energy saving from a list of retrofit options proposed by the industrial partner. In the presented case study, the exergy loss profile identifies the best retrofit option with 17.16% reduction in exergy losses, which finally lead to 3.6% reduction of primary fuel demand. (orig.)

  11. Strengthening of Steel Columns under Load: Torsional-Flexural Buckling

    Directory of Open Access Journals (Sweden)

    Martin Vild

    2016-01-01

    Full Text Available The paper presents experimental and numerical research into the strengthening of steel columns under load using welded plates. So far, the experimental research in this field has been limited mostly to flexural buckling of columns and the preload had low effect on the column load resistance. This paper focuses on the local buckling and torsional-flexural buckling of columns. Three sets of three columns each were tested. Two sets corresponding to the base section (D and strengthened section (E were tested without preloading and were used for comparison. Columns from set (F were first preloaded to the load corresponding to the half of the load resistance of the base section (D. Then the columns were strengthened and after they cooled, they were loaded to failure. The columns strengthened under load (F had similar average resistance as the columns welded without preloading (E, meaning the preload affects even members susceptible to local buckling and torsional-flexural buckling only slightly. This is the same behaviour as of the tested columns from previous research into flexural buckling. The study includes results gained from finite element models of the problem created in ANSYS software. The results obtained from the experiments and numerical simulations were compared.

  12. Numerical Simulations of Settlement of Jet Grouting Columns

    Directory of Open Access Journals (Sweden)

    Juzwa Anna

    2016-03-01

    Full Text Available The paper presents the comparison of results of numerical analyses of interaction between group of jet grouting columns and subsoil. The analyses were conducted for single column and groups of three, seven and nine columns. The simulations are based on experimental research in real scale which were carried out by authors. The final goal for the research is an estimation of an influence of interaction between columns working in a group.

  13. Mathematical model and simulation of the hydrodynamic of air-pulsed sieve plate columns

    International Nuclear Information System (INIS)

    Hannappel, J.; Pfeifer, W.; Rathjen, E.

    1979-02-01

    In this work the dynamic flow events in an air pulsed sieve plate column are described by a simulation model. The model consists of a system of differential equations. The pressure built up by the pulsed air is brought to equilibrium with the pressure losses of the oscillating liquid column in the pulsation tube and in the column. In case of definition of the a) column geometry, b) integral holdup of the column, c) density of the participating phases, d) control times of the pulsed air valves, e) pulse repetition frequency and pulsed air reservoir pressure the height of oscillation and hence the intensity of pulsation are calculated. It is shown by a concrete example that 1) the oscillation of the liquid column in the pulsation tube and in the column is sinusoidal in all cases; 2) generation of a defined pulsation is restricted to the range between 0.3 and 3 Hz; 3) the amount of air needed for pulsation depends on the geometry of the column and in the intensity of pulsation. It can be optimized by appropriate selection of the diameter of the pulsation tube. (orig.) [de

  14. Ductility of reinforced concrete columns confined with stapled strips

    International Nuclear Information System (INIS)

    Tahir, M.F.; Khan, Q.U.Z.; Shabbir, F.; Sharif, M.B.; Ijaz, N.

    2015-01-01

    Response of three 150x150x450mm short reinforced concrete (RC) columns confined with different types of confining steel was investigated. Standard stirrups, strips and stapled strips, each having same cross-sectional area, were employed as confining steel around four comer column bars. Experimental work was aimed at probing into the affect of stapled strip confinement on post elastic behavior and ductility level under cyclic axial load. Ductility ratios, strength enhancement factor and core concrete strengths were compared to study the affect of confinement. Results indicate that strength enhancement in RC columns due to strip and stapled strip confinement was not remarkable as compared to stirrup confined column. It was found that as compared to stirrup confined column, stapled strip confinement enhanced the ductility of RC column by 183% and observed axial capacity of stapled strip confined columns was 41 % higher than the strip confined columns. (author)

  15. Producing The New Regressive Left

    DEFF Research Database (Denmark)

    Crone, Christine

    members, this thesis investigates a growing political trend and ideological discourse in the Arab world that I have called The New Regressive Left. On the premise that a media outlet can function as a forum for ideology production, the thesis argues that an analysis of this material can help to trace...... the contexture of The New Regressive Left. If the first part of the thesis lays out the theoretical approach and draws the contextual framework, through an exploration of the surrounding Arab media-and ideoscapes, the second part is an analytical investigation of the discourse that permeates the programmes aired...... becomes clear from the analytical chapters is the emergence of the new cross-ideological alliance of The New Regressive Left. This emerging coalition between Shia Muslims, religious minorities, parts of the Arab Left, secular cultural producers, and the remnants of the political,strategic resistance...

  16. Study on two phase flow characteristics in annular pulsed extraction column with different ratio of annular width to column diameter

    International Nuclear Information System (INIS)

    Qin Wei; Dai Youyuan; Wang Jiading

    1994-01-01

    Annular pulsed extraction column can successfully provide large throughput and can be made critically safe for fuel reprocessing. This investigation is to study the two phase flow characteristics in annular pulsed extraction column with four different annular width. 30% TBP (in kerosene)-water is used (water as continuous phase). Results show that modified Pratt correlation is valid under the experimental operation conditions for the annular pulsed extraction column. The characteristic velocity U K decreased with the increase of energy input and increased with the increase of the ratio of annular width to column diameter. Flooding velocity correlation is suggested. The deviation of the calculated values from the experimental data is within +20% for four annular width in a pulsed extraction column

  17. Behaviour of FRP confined concrete in square columns

    OpenAIRE

    Diego Villalón, Ana de; Arteaga Iriarte, Ángel; Fernandez Gomez, Jaime Antonio; Perera Velamazán, Ricardo; Cisneros, Daniel

    2015-01-01

    A significant amount of research has been conducted on FRP-confined circular columns, but much less is known about rectangular/square columns in which the effectiveness of confinement is much reduced. This paper presents the results of experimental investigations on low strength square concrete columns confined with FRP. Axial compression tests were performed on ten intermediate size columns. The tests results indicate that FRP composites can significantly improve the bearing capacity and duc...

  18. REGENERATIVE GROWTH OF CORTICOSPINAL TRACT AXONS VIA THE VENTRAL COLUMN AFTER SPINAL CORD INJURY IN MICE

    OpenAIRE

    Steward, Oswald; Zheng, Binhai; Tessier-Lavigne, Marc; Hofstadter, Maura; Sharp, Kelli; Yee, Kelly Matsudaira

    2008-01-01

    Studies that have assessed regeneration of corticospinal tract (CST) axons in mice following genetic modifications or other treatments have tacitly assumed that there is little if any regeneration of CST axons in normal mice in the absence of some intervention. Here, we document a previously unrecognized capability for regenerative growth of CST axons in normal mice that involves growth past the lesion via the ventral column. Mice received dorsal hemisection injuries at thoracic level 6–7, wh...

  19. Collapse of tall granular columns in fluid

    Science.gov (United States)

    Kumar, Krishna; Soga, Kenichi; Delenne, Jean-Yves

    2017-06-01

    Avalanches, landslides, and debris flows are geophysical hazards, which involve rapid mass movement of granular solids, water, and air as a multi-phase system. In order to describe the mechanism of immersed granular flows, it is important to consider both the dynamics of the solid phase and the role of the ambient fluid. In the present study, the collapse of a granular column in fluid is studied using 2D LBM - DEM. The flow kinematics are compared with the dry and buoyant granular collapse to understand the influence of hydrodynamic forces and lubrication on the run-out. In the case of tall columns, the amount of material destabilised above the failure plane is larger than that of short columns. Therefore, the surface area of the mobilised mass that interacts with the surrounding fluid in tall columns is significantly higher than the short columns. This increase in the area of soil - fluid interaction results in an increase in the formation of turbulent vortices thereby altering the deposit morphology. It is observed that the vortices result in the formation of heaps that significantly affects the distribution of mass in the flow. In order to understand the behaviour of tall columns, the run-out behaviour of a dense granular column with an initial aspect ratio of 6 is studied. The collapse behaviour is analysed for different slope angles: 0°, 2.5°, 5° and 7.5°.

  20. Circulation, retention, and mixing of waters within the Weddell-Scotia Confluence, Southern Ocean: The role of stratified Taylor columns

    Science.gov (United States)

    Meredith, Michael P.; Meijers, Andrew S.; Naveira Garabato, Alberto C.; Brown, Peter J.; Venables, Hugh J.; Abrahamsen, E. Povl; Jullion, Loïc.; Messias, Marie-José

    2015-01-01

    The waters of the Weddell-Scotia Confluence (WSC) lie above the rugged topography of the South Scotia Ridge in the Southern Ocean. Meridional exchanges across the WSC transfer water and tracers between the Antarctic Circumpolar Current (ACC) to the north and the subpolar Weddell Gyre to the south. Here, we examine the role of topographic interactions in mediating these exchanges, and in modifying the waters transferred. A case study is presented using data from a free-drifting, intermediate-depth float, which circulated anticyclonically over Discovery Bank on the South Scotia Ridge for close to 4 years. Dimensional analysis indicates that the local conditions are conducive to the formation of Taylor columns. Contemporaneous ship-derived transient tracer data enable estimation of the rate of isopycnal mixing associated with this column, with values of O(1000 m2/s) obtained. Although necessarily coarse, this is of the same order as the rate of isopycnal mixing induced by transient mesoscale eddies within the ACC. A picture emerges of the Taylor column acting as a slow, steady blender, retaining the waters in the vicinity of the WSC for lengthy periods during which they can be subject to significant modification. A full regional float data set, bathymetric data, and a Southern Ocean state estimate are used to identify other potential sites for Taylor column formation. We find that they are likely to be sufficiently widespread to exert a significant influence on water mass modification and meridional fluxes across the southern edge of the ACC in this sector of the Southern Ocean.

  1. CUB DI (Deionization) column control system

    International Nuclear Information System (INIS)

    Seino, K.C.

    1999-01-01

    For the old MR (Main Ring), deionization was done with two columns in CUB, using an ion exchange process. Typically 65 GPM of LCW flew through a column, and the resistivity was raised from 3 Mohm-cm to over 12 Mohm-cm. After a few weeks, columns lost their effectiveness and had to be regenerated in a process involving backwashing and adding hydrochloric acid and sodium hydroxide. For normal MR operations, LCW returned from the ring and passed through the two columns in parallel for deionization, although the system could have been operated satisfactorily with only one in use. A 3000 gallon reservoir (the Spheres) provided a reserve of LCW for allowing water leaks and expansions in the MR. During the MI (Main Injector) construction period, the third DI column was added to satisfy requirements for the MI. When the third column was added, the old regeneration controller was replaced with a new controller based on an Allen-Bradley PLC (i.e., SLC-5/04). The PLC is widely used and well documented, and therefore it may allow us to modify the regeneration programs in the future. In addition to the above regeneration controller, the old control panels (which were used to manipulate pumps and valves to supply LCW in Normal mode and to do Int. Recir. (Internal Recirculation) and Makeup) were replaced with a new control system based on Sixtrak Gateway and I/O modules. For simplicity, the new regeneration controller is called as the US Filter system, and the new control system is called as the Fermilab system in this writing

  2. Functional asymmetry between the left and right human fusiform gyrus explored through electrical brain stimulation.

    Science.gov (United States)

    Rangarajan, Vinitha; Parvizi, Josef

    2016-03-01

    The ventral temporal cortex (VTC) contains several areas with selective responses to words, numbers, faces, and objects as demonstrated by numerous human and primate imaging and electrophysiological studies. Our recent work using electrocorticography (ECoG) confirmed the presence of face-selective neuronal populations in the human fusiform gyrus (FG) in patients implanted with intracranial electrodes in either the left or right hemisphere. Electrical brain stimulation (EBS) disrupted the conscious perception of faces only when it was delivered in the right, but not left, FG. In contrast to our previous findings, here we report both negative and positive EBS effects in right and left FG, respectively. The presence of right hemisphere language dominance in the first, and strong left-handedness and poor language processing performance in the second case, provide indirect clues about the functional architecture of the human VTC in relation to hemispheric asymmetries in language processing and handedness. Copyright © 2015 Elsevier Ltd. All rights reserved.

  3. Evolving Concepts of Pulmonary Hypertension Secondary to Left Heart Disease.

    Science.gov (United States)

    Ramu, Bhavadharini; Thenappan, Thenappan

    2016-04-01

    Pulmonary hypertension associated with left heart disease is the most common form of pulmonary hypertension. Although its pathophysiology remains incompletely understood, it is now well recognized that the presence of pulmonary hypertension is associated with a worse prognosis. Right ventricular failure has independent and additive prognostic value over pulmonary hypertension for adverse outcomes in left heart disease. Recently, several new terminologies have been introduced to better define and characterize the nature and severity of pulmonary hypertension. Several new treatment options including the use of pulmonary arterial hypertension specific therapies are being considered, but there is lack of evidence. Here, we review the recent advances in this field and summarize the diagnostic and therapeutic modalities of use in the management of pulmonary hypertension associated with left heart disease.

  4. NOx retention in scrubbing column

    International Nuclear Information System (INIS)

    Nakazone, A.K.; Costa, R.E.; Lobao, A.S.T.; Matsuda, H.T.; Araujo, B.F.

    1988-07-01

    During the UO 2 dissolution in nitric acid, some different species of NO x are released. The off gas can either be refluxed to the dissolver or be released and retained on special columns. The final composition of the solution is the main parameter to take in account. A process for nitrous gases retention using scubber columns containing H 2 O or diluted HNO 3 is presented. Chemiluminescence measurement was employed to NO x evalution before and after scrubbing. Gas flow, temperature, residence time are the main parameters considered in this paper. For the dissolution of 100g UO 2 in 8M nitric acid, a 6NL/h O 2 flow was the best condition for the NO/NO 2 oxidation with maximum adsorption in the scrubber columns. (author) [pt

  5. JGOFS IV. Subproject: natural radionuclides as tracers for particle dynamics in the water column. Final report

    International Nuclear Information System (INIS)

    Scholten, J.C.; Fietzke, J.; Mangini, A.; Stoffers, P.

    2000-01-01

    As part of the German JOINT GLOBAL OCEAN FLUX STUDY (JGOFS) the aim of the project was to investigate the particle dynamics in the water column, especially to estimate the trapping efficiencies of sediment traps deployed in the eastern North Atlantic (L1: 33 N 21 W; L2: 47 N 19.5 W; L3: 54,4 N 21,1 W; ESTOC: 29,07 N 15,25 W; OMEX: 49 N 12,5 W). This investigation was based on measurements of the distribution of natural radionuclides in the water column and in sediment traps. In the upper water column (≤1000 m) the 230 Th concentrations are similar at all locations investigated and a reversible scavenging model was able to describe the 230 Th distribution. In the deep water-column at L2 and L3 the 230 Th concentrations were significantly lower than predicted from the reversible scavenging model. The 230 Th concentrations here could be described by a scavenging-mixing model which assumes an advection of 230 Th depleted water masses and a rapid ventilation between 3 and 25 years. Based on two models, a mass balance for 230 Th and 231 Pa and a constant removal model, sediment trap efficiencies were calculated to be between 9% and 143%. The lowest efficiencies (9%-36%) were determined in the 500 m and 1000 m traps and no direct relation between water currents velocities and trapping biases were observed. The correction for trapping biases were found to be important for the understanding of the regional differences in the particle flux in the eastern north Atlantic. (orig.) [de

  6. Left-right compatibility in the processing of trading verbs

    Directory of Open Access Journals (Sweden)

    Carmelo Mario Vicario

    2014-01-01

    Full Text Available The research investigating the nature of cognitive processes involved in the representation of economical outcomes is growing. Within this research, the mental accounting model proposes that individuals may well use cognitive operations to organize, evaluate, and keep track of their financial activities (Thaler, 1999. Here we wanted to test this hypothesis by asking to a group of participants to detect a syntax mistake of verbs indicating incoming and going out activities related to economical profit (trading verbs, swapping (swapping verbs and thinking (thinking verbs. We reported a left-right compatibility for trading verbs (i.e. participants were faster with their right hand while detecting verb referring to a monetary gain with respect to a monetary loss; and faster with their left hand while detecting a monetary loss with respect to a monetary gain. However, this pattern of result was not reported while detecting swapping verbs. Results are discussed taking into account the mental accounting theory as well as to the spatial mapping of valence hypothesis.

  7. An elusive persistent left superior vena cava draining into left atrium

    NARCIS (Netherlands)

    A. Soward; F.J. ten Cate (Folkert); P.M. Fioretti (Paolo); P.W.J.C. Serruys (Patrick); J.R.T.C. Roelandt (Jos)

    1986-01-01

    textabstractA case report of a persistent left superior vena cava draining into left atrium with a fibromuscular left ventricular outflow tract obstruction and a small atrial septal defect. The anomalous vessel escaped detection during two right and left heart catheterizations from the right arm and

  8. The shapes of column density PDFs. The importance of the last closed contour

    Science.gov (United States)

    Alves, João; Lombardi, Marco; Lada, Charles J.

    2017-10-01

    The probability distribution function of column density (PDF) has become the tool of choice for cloud structure analysis and star formation studies. Its simplicity is attractive, and the PDF could offer access to cloud physical parameters otherwise difficult to measure, but there has been some confusion in the literature on the definition of its completeness limit and shape at the low column density end. In this letter we use the natural definition of the completeness limit of a column density PDF, the last closed column density contour inside a surveyed region, and apply it to a set of large-scale maps of nearby molecular clouds. We conclude that there is no observational evidence for log-normal PDFs in these objects. We find that all studied molecular clouds have PDFs well described by power laws, including the diffuse cloud Polaris. Our results call for a new physical interpretation of the shape of the column density PDFs. We find that the slope of a cloud PDF is invariant to distance but not to the spatial arrangement of cloud material, and as such it is still a useful tool for investigating cloud structure.

  9. THE 'TRUE' COLUMN DENSITY DISTRIBUTION IN STAR-FORMING MOLECULAR CLOUDS

    International Nuclear Information System (INIS)

    Goodman, Alyssa A.; Pineda, Jaime E.; Schnee, Scott L.

    2009-01-01

    We use the COMPLETE Survey's observations of the Perseus star-forming region to assess and intercompare the three methods used for measuring column density in molecular clouds: near-infrared (NIR) extinction mapping; thermal emission mapping in the far-IR; and mapping the intensity of CO isotopologues. Overall, the structures shown by all three tracers are morphologically similar, but important differences exist among the tracers. We find that the dust-based measures (NIR extinction and thermal emission) give similar, log-normal, distributions for the full (∼20 pc scale) Perseus region, once careful calibration corrections are made. We also compare dust- and gas-based column density distributions for physically meaningful subregions of Perseus, and we find significant variations in the distributions for those (smaller, ∼few pc scale) regions. Even though we have used 12 CO data to estimate excitation temperatures, and we have corrected for opacity, the 13 CO maps seem unable to give column distributions that consistently resemble those from dust measures. We have edited out the effects of the shell around the B-star HD 278942 from the column density distribution comparisons. In that shell's interior and in the parts where it overlaps the molecular cloud, there appears to be a dearth of 13 CO, which is likely due either to 13 CO not yet having had time to form in this young structure and/or destruction of 13 CO in the molecular cloud by the HD 278942's wind and/or radiation. We conclude that the use of either dust or gas measures of column density without extreme attention to calibration (e.g., of thermal emission zero-levels) and artifacts (e.g., the shell) is more perilous than even experts might normally admit. And, the use of 13 CO data to trace total column density in detail, even after proper calibration, is unavoidably limited in utility due to threshold, depletion, and opacity effects. If one's main aim is to map column density (rather than temperature

  10. Duplication of the Left Vertebral Artery Origin: A Case Report

    Energy Technology Data Exchange (ETDEWEB)

    Shin, Sang Wook; Park, Dong Woo; Park, Choong Ki; Lee, Young Jun [Dept. of Radiology, College of Medicine, Hanyang University, Hanyang University Guri Hospital, Guri (Korea, Republic of)

    2013-01-15

    Duplication of vertebral arteries is a very rare but clinically important condition. A duplicated vertebral artery origin can influence hemodynamics, pathogenesis of vascular lesions and treatment options. In cases of vertebral artery duplication, the vertebral arteries generally enter the transverse foramen higher up than normal. Awareness of these vertebral artery variants before procedures, such as neurointervention or surgery, may be beneficial. Here, we describe a case of a 51-year-old female patient with left vertebral artery duplication which was detected incidentally.

  11. Duplication of the Left Vertebral Artery Origin: A Case Report

    International Nuclear Information System (INIS)

    Shin, Sang Wook; Park, Dong Woo; Park, Choong Ki; Lee, Young Jun

    2013-01-01

    Duplication of vertebral arteries is a very rare but clinically important condition. A duplicated vertebral artery origin can influence hemodynamics, pathogenesis of vascular lesions and treatment options. In cases of vertebral artery duplication, the vertebral arteries generally enter the transverse foramen higher up than normal. Awareness of these vertebral artery variants before procedures, such as neurointervention or surgery, may be beneficial. Here, we describe a case of a 51-year-old female patient with left vertebral artery duplication which was detected incidentally.

  12. The art and science of forming packed analytical high-performance liquid chromatography columns.

    Science.gov (United States)

    Kirkland, J J; Destefano, J J

    2006-09-08

    Columns of packed particles still are the most popular devices for high-performance liquid chromatography (HPLC) separations because of their great utility, excellent performance and wide variety. However, the forming of packed beds for efficient, stable columns traditionally has been an art where the basics of how to form optimum beds generally was not well understood. The recent development of monolith rods was introduced in part to overcome the difficulty of producing stable beds of packing particles. However, these materials are less versatile than packed particle columns. Technology developments in recent years have produced a better understanding among those skilled in the practice of how to form optimized packed beds, and this has led to widely available, high-quality commercial columns. This presentation discusses the developments that led to the present state of column packing technology. Important steps in the packing of efficient, stable beds are described. The key step of selecting the best solvent for the slurry packing method is emphasized. Factors affecting the mechanical stability of packed columns also are discussed. The early art of packing columns now has evolved into a more scientific approach that allows the packing of good columns with a minimum of effort and time.

  13. Column, particularly extraction column, for fission and/or breeder materials

    International Nuclear Information System (INIS)

    Vietzke, H.; Pirk, H.

    1980-01-01

    An absorber rod with a B 4 C insert is situated in the long extraction column for a uranyl nitrate solution or a plutonium nitrate solution. The geometrical dimensions are designed for a high throughput with little corrosion. (DG) [de

  14. The use of phospholipid modified column for the determination of lipophilic properties in high performance liquid chromatography.

    Science.gov (United States)

    Godard, Tal; Grushka, Eli

    2011-03-04

    A new chromatographic stationary phase obtained by coating a reversed phase amide column with phosphatidylcholine based liposomes solution to yield a phospholipid modified column (PLM). The modification is achieved by the dynamic coating method which recycles the coating solution through the column in a closed loop for a period of 24 h. The chromatographic properties of the new column have changed significantly as compared to the original amide column due to the phospholipid coating. A good correlation was observed between n-octanol/water logP values and the logarithm of the retention factor obtained on the PLM column for a large number of solutes. In addition the PLM column was characterized using the linear solvation energy relationship (LSER). The values of the LSER system constants for the PLM column were calculated and were found to be very close to those of the n-octanol/water extraction system thus suggesting that the PLM column can be used for the estimation of n-octanol/water partition coefficient and serve as a possible alternative to the shake-flask method for lipophilicity determination. In addition, the results suggest that the PLM column can provide an alternative to other phospholipid-based column such as the IAM and the DPC columns. Copyright © 2011 Elsevier B.V. All rights reserved.

  15. Left sided circumaortic and retroaortic left renal veins, renal artery arising from iliac common artery in L-shaped kidney

    International Nuclear Information System (INIS)

    Al-Amin, M.

    2012-01-01

    Full text: Introduction: Renal ectopia is a congenital anomaly with variable clinical presentation. Kidneys are normally located in the retroperitoneal position, on either side of vertebral column, against the psoas muscles but when not at such position, it is called renal ectopia or ectopic kidney. Ectopic kidneys are thought to occur in approximately 1 in 1,000 births but only about 1 in 10 of these is ever diagnosed. In 90% of crossed ectopy, there is at least partial fusion of the kidneys. Left-to right ectopy is thought to be three times more common. Some of these are discovered incidentally, when a child or adult is having ultrasonography for a medical condition unrelated to renal ectopia. In a crossed fused renal ectopic kidney, complications such as nephrolithiasis, infection, and hydronephrosis approaches over 50%. Simple renal ectopia refers to kidney that is located on the proper side but abnormal in position. Crossed renal ectopia was first described by Pannorlus in 1964 and refer to kidney that has crossed from left to right or vice-versa, with moving of one kidney to the opposite side following ascent of the other kidney, so that both kidneys are located on the same side of the body, mostly fused called crossed fused ectopia. The fusion of the two kidneys is believed to result from (1) failure of the primitive nephrogenic cell masses to separate or (2) fusion of the two blastemas during their abdominal ascent. Discussion: A 57-year-old woman with a new found hematological disease. CT exam was performed with intravenous application of contrast media. Like an additional findings we visualized the presence of right to-left ectopy (L - shaped kidney) and the presence of left circumaortic renal vein emanating from a normally situated left kidney and retroaortic renal vein as having been located by the ectopic right kidney. Conclusion: By crossed renal ectopia is meant congenital displacement of one kidney to the opposite side. The conditional may present

  16. Gas chromatographic column for the Viking 1975 molecular analysis experiment

    Science.gov (United States)

    Novotny, M.; Hayes, J. M.; Bruner, F.; Simmonds, P. G.

    1975-01-01

    A gas chromatographic column has been developed for use in the remote analysis of the Martian surface. The column, which utilizes a liquid-modified organic adsorbent (Tenax) as the stationary phase, provides efficient transmission and resolution of nanogram quantities of organic materials in the presence of millionfold excesses of water and carbon dioxide.

  17. Layer- and column-specific knockout of NMDA receptors in pyramidal neurons of the mouse barrel cortex.

    Directory of Open Access Journals (Sweden)

    Rachel Aronoff

    2007-11-01

    Full Text Available Viral vectors injected into the mouse brain offer the possibility for localized genetic modifications in a highly controlled manner. Lentivector injection into mouse neocortex transduces cells within a diameter of approximately 200µm, which closely matches the lateral scale of a column in barrel cortex. The depth and volume of the injection determines which cortical layer is transduced. Furthermore, transduced gene expression from the lentivector can be limited to predominantly pyramidal neurons by using a 1.3kb fragment of the αCaMKII promoter. This technique therefore allows genetic manipulation of a specific cell type in defined columns and layers of the neocortex. By expressing Cre recombinase from such a lentivector in gene-targeted mice carrying a floxed gene, highly specific genetic lesions can be induced. Here, we demonstrate the utility of this approach by specifically knocking out NMDA receptors (NMDARs in pyramidal neurons in the somatosensory barrel cortex of gene-targeted mice carrying floxed NMDAR 1 genes. Neurons transduced with lentivector encoding GFP and Cre recombinase exhibit not only reductions in NMDAR 1 mRNA levels, but reduced NMDAR-dependent currents and pairing-induced synaptic potentiation. This technique for knockout of NMDARs in a cell type, column- and layer-specific manner in the mouse somatosensory cortex may help further our understanding of the functional roles of NMDARs in vivo during sensory perception and learning.

  18. Concepts on the pathogenesis of adolescent idiopathic scoliosis. Bone growth and mass, vertebral column, spinal cord, brain, skull, extra-spinal left-right skeletal length asymmetries, disproportions and molecular pathogenesis.

    Science.gov (United States)

    Burwell, R Geoffrey; Dangerfield, Peter H; Freeman, Brian J C

    2008-01-01

    There is no generally accepted scientific theory for the causes of adolescent idiopathic scoliosis (AIS). Encouraging advances thought to be related to AIS pathogenesis have recently been made in several fields including anthropometry of bone growth, bone mass, spinal growth modulation, extra-spinal left-right skeletal length asymmetries and disproportions, magnetic resonance imaging of vertebral column, spinal cord, brain, skull, and molecular pathogenesis. These advances are leading to the evaluation of new treatments including attempts at minimally invasive surgery on the spine and peri-apical ribs. Several concepts of AIS are outlined indicating their clinical applications but not their research potential. The concepts, by derivation morphological, molecular and mathematical, are addressed in 15 sections: 1) initiating and progressive factors; 2) relative anterior spinal overgrowth; 3) dorsal shear forces that create axial rotational instability; 4) rotational preconstraint; 5) uncoupled, or asynchronous, spinal neuro-osseous growth; 6) brain, nervous system and skull; 7) a novel neuro-osseous escalator concept based on a putative abnormality of two normal polarized processes namely, a) increasing skeletal dimensions, and b) the CNS body schema - both contained within a neuro-osseous timing of maturation (NOTOM) concept; 8) transverse plane pelvic rotation, skeletal asymmetries and developmental theory; 9) thoraco-spinal concept; 10) origin in contracture at the hips; 11) osteopenia; 12) melatonin deficiency; 13) systemic melatonin-signaling pathway dysfunction; 14) platelet calmodulin dysfunction; and 15) biomechanical spinal growth modulation. From these concepts, a collective model for AIS pathogenesis is formulated. The central concept of this model includes the body schema of the neural systems, widely-studied in adults, that control normal posture and coordinated movements with frames of reference in the posterior parietal cortex. The escalator concept

  19. Ultra high pressure liquid chromatography. Column permeability and changes of the eluent properties.

    Science.gov (United States)

    Gritti, Fabrice; Guiochon, Georges

    2008-04-11

    The behavior of four similar liquid chromatography columns (2.1mm i.d. x 30, 50, 100, and 150 mm, all packed with fine particles, average d(p) approximately 1.7 microm, of bridged ethylsiloxane/silica hybrid-C(18), named BEH-C(18)) was studied in wide ranges of temperature and pressure. The pressure and the temperature dependencies of the viscosity and the density of the eluent (pure acetonitrile) along the columns were also derived, using the column permeabilities and applying the Kozeny-Carman and the heat balance equations. The heat lost through the external surface area of the chromatographic column was directly derived from the wall temperature of the stainless steel tube measured with a precision of +/-0.2 degrees C in still air and +/-0.1 degrees C in the oven compartment. The variations of the density and viscosity of pure acetonitrile as a function of the temperature and pressure was derived from empirical correlations based on precise experimental data acquired between 298 and 373 K and at pressures up to 1.5 kbar. The measurements were made with the Acquity UPLC chromatograph that can deliver a maximum flow rate of 2 mL/min and apply a maximum column inlet pressure of 1038 bar. The average Kozeny-Carman permeability constant of the columns was 144+/-3.5%. The temperature hence the viscosity and the density profiles of the eluent along the column deviate significantly from linear behavior under high-pressure gradients. For a 1000 bar pressure drop, we measured DeltaT=25-30 K, (Deltaeta/eta) approximately 100%, and (Deltarho/rho) approximately 10%. These results show that the radial temperature profiles are never fully developed within 1% for any of the columns, even under still-air conditions. This represents a practical advantage regarding the apparent column efficiency at high flow rates, since the impact of the differential analyte velocity between the column center and the column wall is not maximum. The interpretation of the peak profiles recorded in

  20. Water hammer with column separation : a historical review

    NARCIS (Netherlands)

    Bergant, A.; Simpson, A.R.; Tijsseling, A.S.

    2006-01-01

    Column separation refers to the breaking of liquid columns in fully filled pipelines. This may occur in a water-hammer event when the pressure in a pipeline drops to the vapor pressure at specific locations such as closed ends, high points or knees (changes in pipe slope). The liquid columns are

  1. Two convergent routes to the left-wing fragment of ciguatoxin CTX3C using O,S-acetals as key intermediates.

    Science.gov (United States)

    Inoue, Masayuki; Yamashita, Shuji; Ishihara, Yuuki; Hirama, Masahiro

    2006-12-07

    Ciguatoxins, principal causative toxins of ciguatera seafood poisoning, are large ladderlike polycyclic ethers. Here, we report two convergent routes to synthesis of the multiolefinic left half of ciguatoxins based on a newly developed acyl radical strategy. Remarkably, only 13 steps from the monocyclic E-ring were required to construct the left wing. [reaction: see text

  2. Column studies on the sorption of radioactive isotopes by some natural clay minerals

    International Nuclear Information System (INIS)

    Abdel-Gawad, A.S.; Misak, N.Z.; Maghrawy, H.B.; Shafik, A.

    1982-01-01

    Different types of naturally occuring minerals have been investigated in respect of the sorption of various radioisotopes. The present work deals with column studies of the sorption of 89 Sr and 60 Co on four natural bentonites. Columns having a cross section of 1.47 cm 2 were used for determining the breakthrough capacities for both Sr and Co. The applicability of the Glueckauf plate theory to the systems was tested. It was found that HETP is constant for a given system of column and cationic species, which proves the applicability of the theory. From this, it follows that the data obtained for the short laboratory columns can be used to predict the breakthrough behaviour for longer columns. (author)

  3. Functional resting-state connectivity of the human motor network: differences between right- and left-handers.

    Science.gov (United States)

    Pool, Eva-Maria; Rehme, Anne K; Eickhoff, Simon B; Fink, Gereon R; Grefkes, Christian

    2015-04-01

    Handedness is associated with differences in activation levels in various motor tasks performed with the dominant or non-dominant hand. Here we tested whether handedness is reflected in the functional architecture of the motor system even in the absence of an overt motor task. Using resting-state functional magnetic resonance imaging we investigated 18 right- and 18 left-handers. Whole-brain functional connectivity maps of the primary motor cortex (M1), supplementary motor area (SMA), dorsolateral premotor cortex (PMd), pre-SMA, inferior frontal junction and motor putamen were compared between right- and left-handers. We further used a multivariate linear support vector machine (SVM) classifier to reveal the specificity of brain regions for classifying handedness based on individual resting-state maps. Using left M1 as seed region, functional connectivity analysis revealed stronger interhemispheric functional connectivity between left M1 and right PMd in right-handers as compared to left-handers. This connectivity cluster contributed to the individual classification of right- and left-handers with 86.2% accuracy. Consistently, also seeding from right PMd yielded a similar handedness-dependent effect in left M1, albeit with lower classification accuracy (78.1%). Control analyses of the other resting-state networks including the speech and the visual network revealed no significant differences in functional connectivity related to handedness. In conclusion, our data revealed an intrinsically higher functional connectivity in right-handers. These results may help to explain that hand preference is more lateralized in right-handers than in left-handers. Furthermore, enhanced functional connectivity between left M1 and right PMd may serve as an individual marker of handedness. Copyright © 2015 Elsevier Inc. All rights reserved.

  4. Magnetic resonance tomography of the vertebral column and spinal canal

    International Nuclear Information System (INIS)

    Uhlenbrock, D.; Brueckmann, H.; Bunke, J.; Giesecke, J.; Heinzerling, J.; Kunze, V.; Mirvis, S.E.; Weidner, A.; Wolf, A.L.

    1992-01-01

    In addition to all the aspects pertinent to diagnostic procedures in the vertebral column and spinal canal this pocket book provides complete coverage of congenital and acquired disorders in the fields of orthopedics, neurology and neurosurgery - including malformations of the spinal canal, degenerative vertebral diseases, tumours, inflammatory changes and vascular diseases, to mention only a few. The authors discuss the question of how image qualities can be influenced and the most information obtained from the different pulse sequences. They outline future development trends and give advice on the reduction of artefacts. The principles that must be adhered to in surgical intervention and nmr imaging for the post-operative assessment of vertebral disk syndromes and tumours are just as important an issue here as is the information the surgeon expects to obtain through diagnostic nmr imaging and the recommendations to be given by the radiologist. (orig.) With 265 figs [de

  5. Results of the eruptive column model inter-comparison study

    Science.gov (United States)

    Costa, Antonio; Suzuki, Yujiro; Cerminara, M.; Devenish, Ben J.; Esposti Ongaro, T.; Herzog, Michael; Van Eaton, Alexa; Denby, L.C.; Bursik, Marcus; de' Michieli Vitturi, Mattia; Engwell, S.; Neri, Augusto; Barsotti, Sara; Folch, Arnau; Macedonio, Giovanni; Girault, F.; Carazzo, G.; Tait, S.; Kaminski, E.; Mastin, Larry G.; Woodhouse, Mark J.; Phillips, Jeremy C.; Hogg, Andrew J.; Degruyter, Wim; Bonadonna, Costanza

    2016-01-01

    This study compares and evaluates one-dimensional (1D) and three-dimensional (3D) numerical models of volcanic eruption columns in a set of different inter-comparison exercises. The exercises were designed as a blind test in which a set of common input parameters was given for two reference eruptions, representing a strong and a weak eruption column under different meteorological conditions. Comparing the results of the different models allows us to evaluate their capabilities and target areas for future improvement. Despite their different formulations, the 1D and 3D models provide reasonably consistent predictions of some of the key global descriptors of the volcanic plumes. Variability in plume height, estimated from the standard deviation of model predictions, is within ~ 20% for the weak plume and ~ 10% for the strong plume. Predictions of neutral buoyancy level are also in reasonably good agreement among the different models, with a standard deviation ranging from 9 to 19% (the latter for the weak plume in a windy atmosphere). Overall, these discrepancies are in the range of observational uncertainty of column height. However, there are important differences amongst models in terms of local properties along the plume axis, particularly for the strong plume. Our analysis suggests that the simplified treatment of entrainment in 1D models is adequate to resolve the general behaviour of the weak plume. However, it is inadequate to capture complex features of the strong plume, such as large vortices, partial column collapse, or gravitational fountaining that strongly enhance entrainment in the lower atmosphere. We conclude that there is a need to more accurately quantify entrainment rates, improve the representation of plume radius, and incorporate the effects of column instability in future versions of 1D volcanic plume models.

  6. The left atrium, atrial fibrillation, and the risk of stroke in hypertensive patients with left ventricular hypertrophy

    DEFF Research Database (Denmark)

    Wachtell, K.; Devereux, R.B.; Lyle, P.A.

    2008-01-01

    was superior to atenolol-based treatment for reducing new-onset AF and complications, especially stroke, associated with new-onset or pre-existing AF. Potential mechanisms of AF prevention by angiotensin receptor blockade supported by LIFE results include greater reduction in left atrial size and LV......The Losartan Intervention For Endpoint reduction in hypertension (LIFE) study provided extensive data on predisposing factors, consequences, and prevention of atrial fibrillation (AF) in patients with hypertension and left ventricular (LV) hypertrophy. Randomized losartan-based treatment...... hypertrophy. Differential effects of antihypertensive treatment on the left atrium and left ventricle may help prevent AF and reduce risk of stroke associated with hypertensive heart disease Udgivelsesdato: 2008/12...

  7. Plasmacytoid lymphoma within a left atrial myxoma: a rare coincidental dual pathology.

    Science.gov (United States)

    White, Ralph W; Hirst, Natalie A; Edward, Sara; Nair, Unnikrishnan R

    2010-01-01

    Primary malignant cardiac neoplasms are extremely rare. The occurrence of a malignant lymphoid tumour within a left atrial myxoma is highly atypical, with only one such case previously reported. Here, we describe a patient who presented with symptoms and signs of a left atrial myxoma. Subsequent specimen histology demonstrated the presence of lymphoma within the myxoma. We discuss the importance of histological diagnosis in order to best direct treatment and prognosis of such cases.

  8. Application of a Fast Separation Method for Anti-diabetics in Pharmaceuticals Using Monolithic Column: Comparative Study With Silica Based C-18 Particle Packed Column.

    Science.gov (United States)

    Hemdan, A; Abdel-Aziz, Omar

    2018-04-01

    Run time is a predominant factor in HPLC for quality control laboratories especially if there is large number of samples have to be analyzed. Working at high flow rates cannot be attained with silica based particle packed column due to elevated backpressure issues. The use of monolithic column as an alternative to traditional C-18 column was tested for fast separation of pharmaceuticals, where the results were very competitive. The performance comparison of both columns was tested for separation of anti-diabetic combination containing Metformin, Pioglitazone and Glimepiride using Gliclazide as an internal standard. Working at high flow rates with less significant backpressure was obtained with the monolithic column where the run time was reduced from 6 min in traditional column to only 1 min in monolithic column with accepted resolution. The structure of the monolith contains many pores which can adapt the high flow rate of the mobile phase. Moreover, peak symmetry and equilibration time were more efficient with monolithic column.

  9. Partial path column generation for the vehicle routing problem with time windows

    DEFF Research Database (Denmark)

    Petersen, Bjørn; Jepsen, Mads Kehlet

    2009-01-01

    This paper presents a column generation algorithm for the Vehicle Routing Problem with Time Windows (VRPTW). Traditionally, column generation models of the VRPTW have consisted of a Set Partitioning master problem with each column representing a route, i.e., a resource feasible path starting...... and ending at the depot. Elementary routes (no customer visited more than once) have shown superior results on difficult instances (less restrictive capacity and time windows). However, the pricing problems do not scale well when the number of feasible routes increases, i.e., when a route may contain a large...... number of customers. We suggest to relax that ‘each column is a route’ into ‘each column is a part of the giant tour’; a so-called partial path, i.e., not necessarily starting and ending in the depot. This way, the length of the partial path can be bounded and a better control of the size of the solution...

  10. Preparation and evaluation of 400μm I.D. polymer-based hydrophilic interaction chromatography monolithic columns with high column efficiency.

    Science.gov (United States)

    Liu, Chusheng; Li, Haibin; Wang, Qiqin; Crommen, Jacques; Zhou, Haibo; Jiang, Zhengjin

    2017-08-04

    The quest for higher column efficiency is one of the major research areas in polymer-based monolithic column fabrication. In this research, two novel polymer-based HILIC monolithic columns with 400μm I.D.×800μm O.D. were prepared based on the thermally initiated co-polymerization of N,N-dimethyl-N-(3-methacrylamidopropyl)-N-(3-sulfopropyl) ammonium betaine (SPP) and ethylene glycol dimethacrylate (EDMA) or N,N'-methylenebisacrylamide (MBA). In order to obtain a satisfactory performance in terms of column permeability, mechanical stability, efficiency and selectivity, the polymerization parameters were systematically optimized. Column efficiencies as high as 142, 000 plates/m and 120, 000 plates/m were observed for the analysis of neutral compounds at 0.6mm/s on the poly(SPP-co-MBA) and poly(SPP-co-EDMA) monoliths, respectively. Furthermore, the Van Deemter plots for thiourea on the two monoliths were compared with that on a commercial silica based ZIC-HILIC column (3.5μm, 200Å, 150mm×300μm I.D.) using ACN/H 2 O (90/10, v/v) as the mobile phase at room temperature. It was noticeable that the Van Deemter curves for both monoliths, particularly the poly(SPP-co-MBA) monolith, are significantly flatter than that obtained for the ZIC-HILIC column, which indicates that in spite of their larger internal diameters, they yield better overall efficiency, with less peak dispersion, across a much wider range of usable linear velocities. A clearly better separation performance was also observed for nucleobases, nucleosides, nucleotides and small peptides on the poly(SPP-co-MBA) monolith compared to the ZIC-HILIC column. It is particularly worth mentioning that these 400μm I.D. polymer-based HILIC monolithic columns exhibit enhanced mechanical strength owing to the thicker capillary wall of the fused-silica capillaries. Copyright © 2017 Elsevier B.V. All rights reserved.

  11. HEAT TRANSFER ANALYSIS FOR FIXED CST AND RF COLUMNS

    International Nuclear Information System (INIS)

    Lee, S

    2007-01-01

    In support of a small column ion exchange (SCIX) process for the Savannah River Site waste processing program, transient and steady state two-dimensional heat transfer models have been constructed for columns loaded with cesium-saturated crystalline silicotitanate (CST) or spherical Resorcinol-Formaldehyde (RF) beads and 6 molar sodium tank waste supernate. Radiolytic decay of sorbed cesium results in heat generation within the columns. The models consider conductive heat transfer only with no convective cooling and no process flow within the columns (assumed column geometry: 27.375 in ID with a 6.625 in OD center-line cooling pipe). Heat transfer at the column walls was assumed to occur by natural convection cooling with 35 C air. A number of modeling calculations were performed using this computational heat transfer approach. Minimal additional calculations were also conducted to predict temperature increases expected for salt solution processed through columns of various heights at the slowest expected operational flow rate of 5 gpm. Results for the bounding model with no process flow and no active cooling indicate that the time required to reach the boiling point of ∼130 C for a CST-salt solution mixture containing 257 Ci/liter of Cs-137 heat source (maximum expected loading for SCIX applications) at 35 C initial temperature is about 6 days. Modeling results for a column actively cooled with external wall jackets and the internal coolant pipe (inlet coolant water temperature: 25 C) indicate that the CST column can be maintained non-boiling under these conditions indefinitely. The results also show that the maximum temperature of an RF-salt solution column containing 133 Ci/liter of Cs-137 (maximum expected loading) will never reach boiling under any conditions (maximum predicted temperature without cooling: 88 C). The results indicate that a 6-in cooling pipe at the center of the column provides the most effective cooling mechanism for reducing the maximum

  12. Balloon-occluded retrograde transvenous obliteration of gastric varix draining via the left inferior phrenic vein into the left hepatic vein

    International Nuclear Information System (INIS)

    Ibukuro, Kenji; Mori, Koichi; Tsukiyama, Toshitaka; Inoue, Yoshihiro; Iwamoto, Yukako; Tagawa, Kazumi

    1999-01-01

    We encountered a patient with gastric varix draining not via the usual left suprarenal vein but via the left inferior phrenic vein joining the left hepatic vein. Transfemoral balloon-occluded retrograde transvenous obliteration (BRTO) of the varix was performed under balloon occlusion of the left inferior phrenic vein via the left hepatic vein and retrograde injection of the sclerosing agent (5% of ethanolamine oleate) into the gastric varix. Disappearance of the gastric varix was confirmed on endoscopic examination 2 months later.

  13. Novel field emission SEM column with beam deceleration technology

    International Nuclear Information System (INIS)

    Jiruše, Jaroslav; Havelka, Miloslav; Lopour, Filip

    2014-01-01

    A novel field-emission SEM column has been developed that features Beam Deceleration Mode, high-probe current and ultra-fast scanning. New detection system in the column is introduced to detect true secondary electron signal. The resolution power at low energy was doubled for conventional SEM optics and moderately improved for immersion optics. Application examples at low landing energies include change of contrast, imaging of non-conductive samples and thin layers. - Highlights: • A novel field-emission SEM column has been developed. • Implemented beam deceleration improves the SEM resolution at 1 keV two times. • New column maintains high analytical potential and wide field of view. • Detectors integrated in the column allow gaining true SE and BE signal separately. • Performance of the column is demonstrated on low energy applications

  14. Novel field emission SEM column with beam deceleration technology

    Energy Technology Data Exchange (ETDEWEB)

    Jiruše, Jaroslav; Havelka, Miloslav; Lopour, Filip

    2014-11-15

    A novel field-emission SEM column has been developed that features Beam Deceleration Mode, high-probe current and ultra-fast scanning. New detection system in the column is introduced to detect true secondary electron signal. The resolution power at low energy was doubled for conventional SEM optics and moderately improved for immersion optics. Application examples at low landing energies include change of contrast, imaging of non-conductive samples and thin layers. - Highlights: • A novel field-emission SEM column has been developed. • Implemented beam deceleration improves the SEM resolution at 1 keV two times. • New column maintains high analytical potential and wide field of view. • Detectors integrated in the column allow gaining true SE and BE signal separately. • Performance of the column is demonstrated on low energy applications.

  15. Involvement of the Left Supramarginal Gyrus in Manipulation Judgment Tasks: Contributions to Theories of Tool Use.

    Science.gov (United States)

    Lesourd, Mathieu; Osiurak, François; Navarro, Jordan; Reynaud, Emanuelle

    2017-09-01

    Two theories of tool use, namely the gesture engram and the technical reasoning theories, make distinct predictions about the involvement of the left inferior parietal lobe (IPL) in manipulation judgement tasks. The objective here is to test these alternative predictions based on previous studies on manipulation judgment tasks using transcranial magnetic stimulations (TMS) targeting the left supramarginal gyrus (SMG). We review recent TMS studies on manipulation judgement tasks and confront these data with predictions made by both tool use theories. The left SMG is a highly intertwined region, organized following several functionally distinct areas and TMS may have disrupted a cortical network involved in the ability to use tools rather than only one functional area supporting manipulation knowledge. Moreover, manipulation judgement tasks may be impaired following virtual lesions outside the IPL. These data are more in line with the technical reasoning hypothesis, which assumes that the left IPL does not store manipulation knowledge per se. (JINS, 2017, 23, 685-691).

  16. Fringing-field effects in acceleration columns

    International Nuclear Information System (INIS)

    Yavor, M.I.; Weick, H.; Wollnik, H.

    1999-01-01

    Fringing-field effects in acceleration columns are investigated, based on the fringing-field integral method. Transfer matrices at the effective boundaries of the acceleration column are obtained, as well as the general transfer matrix of the region separating two homogeneous electrostatic fields with different field strengths. The accuracy of the fringing-field integral method is investigated

  17. Inert carriers for column extraction chromatography

    International Nuclear Information System (INIS)

    Katykhin, G.S.

    1978-01-01

    Inert carriers used in column extraction chromatography are reviewed. Such carriers are devided into two large groups: hydrophilic carriers which possess high surface energy and are well wetted only with strongly polar liquids (kieselguhrs, silica gels, glasses, cellulose, Al 2 O 3 ) and water-repellent carriers which possess low surface energy and are well wetted with various organic solvents (polyethylene, polytetrafluorethylene polytrifluorochlorethylene). Properties of various carriers are presented: structure, chemical and radiation stability, adsorption properties, extracting agent capacity. The effect of structure and sizes of particles on the efficiency of chromatography columns is considered. Ways of immovable phase deposition on the carrier and the latter's regeneration. Peculiarities of column packing for preparative and continuous chromatography are discussed

  18. Column properties and flow profiles of a flat, wide column for high-pressure liquid chromatography.

    Science.gov (United States)

    Mriziq, Khaled S; Guiochon, Georges

    2008-04-11

    The design and the construction of a pressurized, flat, wide column for high-performance liquid chromatography (HPLC) are described. This apparatus, which is derived from instruments that implement over-pressured thin layer chromatography, can carry out only uni-dimensional chromatographic separations. However, it is intended to be the first step in the development of more powerful instruments that will be able to carry out two-dimensional chromatographic separations, in which case, the first separation would be a space-based separation, LC(x), taking place along one side of the bed and the second separation would be a time-based separation, LC(t), as in classical HPLC but proceeding along the flat column, not along a tube. The apparatus described consists of a pressurization chamber made of a Plexiglas block and a column chamber made of stainless steel. These two chambers are separated by a thin Mylar membrane. The column chamber is a cavity which is filled with a thick layer (ca. 1mm) of the stationary phase. Suitable solvent inlet and outlet ports are located on two opposite sides of the sorbent layer. The design allows the preparation of a homogenous sorbent layer suitable to be used as a chromatographic column, the achievement of effective seals of the stationary phase layer against the chamber edges, and the homogenous flow of the mobile phase along the chamber. The entire width of the sorbent layer area can be used to develop separations or elute samples. The reproducible performance of the apparatus is demonstrated by the chromatographic separations of different dyes. This instrument is essentially designed for testing detector arrays to be used in a two-dimensional LC(x) x LC(t) instrument. The further development of two-dimension separation chromatographs based on the apparatus described is sketched.

  19. The effect of percutaneous transcatheter occlusion of left atrial appendage on left atrium and adjacent anatomic structure in canine

    International Nuclear Information System (INIS)

    Yang Zhihong; Wu Hong; Qin Yongwen; Hu Jianqiang; Ding Zhongru; Liu Zongjun; Liu Biao; Zheng Xing

    2009-01-01

    Objective: To observe the effect of percutaneous transcatheter occlusion of left atrial appendage (LAA) with a new self-manufactured LAA occluder on left atrium and adjacent anatomic structure in canine. Methods: A new self-manufactured LAA occluder was implanted into the LAA through a transseptal catheter in 20 dogs. Before and after the procedure, the experimental dogs were anaesthetized and examined by transthoracic echocardiography (TTE) to measure the diameter and the volume of the left atrium, the left superior pulmonary vein flow velocity and the left atrioventricular valve flow velocity separately. The contrast radiography of the LAA and the left coronary arteriography were performed. Results: The new LAA occluder was implanted successfully in 14 dogs. No obvious changes in the diameter and the volume of the left atrium, in left superior pulmonary vein flow velocity and in left atrioventricular valve flow velocity were found. On arteriography, left circumflex artery was normally displayed after the procedure. No migration of the occluder was seen on TTE and angiography after procedure. Conclusion: Percutaneous transcatheter occlusion of left atrial appendage with a new self-manufactured LAA occluder has no obvious effect on left atrium and adjacent anatomic structure in experimental canine, which indicates that the new-type device is a safe and feasible occluder for LAA. (authors)

  20. Combined radiologic and endoscopic treatment (using the “rendezvous technique”) of a biliary fistula following left hepatectomy

    Science.gov (United States)

    Gracient, Aurélien; Rebibo, Lionel; Delcenserie, Richard; Yzet, Thierry; Regimbeau, Jean-Marc

    2016-01-01

    Despite the ongoing decrease in the frequency of complications after hepatectomy, biliary fistulas still occur and are associated with high morbidity and mortality rates. Here, we report on an unusual technique for managing biliary fistula following left hepatectomy in a patient in whom the right posterior segmental duct joined the left hepatic duct. The biliary fistula was treated with a combined radiologic and endoscopic procedure based on the “rendezvous technique”. The clinical outcome was good, and reoperation was not required. PMID:27570431

  1. Dynamic effects of diabatization in distillation columns

    DEFF Research Database (Denmark)

    Bisgaard, Thomas; Huusom, Jakob Kjøbsted; Abildskov, Jens

    2013-01-01

    The dynamic effects of diabatization in distillation columns are investigated in simulation emphasizing the heat-integrated distillation column (HIDiC). A generic, dynamic, first-principle model has been formulated, which is flexible enough to describe various diabatic distillation configurations....... Dynamic Relative Gain Array and Singular Value Analysis have been applied in a comparative study of a conventional distillation column and a HIDiC. The study showed increased input-output coupling due to diabatization. Feasible SISO control structures for the HIDiC were also found and control...

  2. Dynamic Effects of Diabatization in Distillation Columns

    DEFF Research Database (Denmark)

    Bisgaard, Thomas; Huusom, Jakob Kjøbsted; Abildskov, Jens

    2012-01-01

    The dynamic eects of diabatization in distillation columns are investigated in simulation with primary focus on the heat-integrated distillation column (HIDiC). A generic, dynamic, rst-principle model has been formulated, which is exible to describe various diabatic distillation congurations....... Dynamic Relative Gain Array and Singular Value Analysis have been applied in a comparative study of a conventional distillation column and a HIDiC. The study showed increased input-output coupling due to diabatization. Feasible SISO control structures for the HIDiC were also found. Control...

  3. Cesium ion exchange using actual waste: Column size considerations

    International Nuclear Information System (INIS)

    Brooks, K.P.

    1996-04-01

    It is presently planned to remove cesium from Hanford tank waste supernates and sludge wash solutions using ion exchange. To support the development of a cesium ion exchange process, laboratory experiments produced column breakthrough curves using wastes simulants in 200 mL columns. To verify the validity of the simulant tests, column runs with actual supernatants are being planned. The purpose of these actual waste tests is two-fold. First, the tests will verify that use of the simulant accurately reflects the equilibrium and rate behavior of the resin compared to actual wastes. Batch tests and column tests will be used to compare equilibrium behaviors and rate behaviors, respectively. Second, the tests will assist in clarifying the negative interactions between the actual waste and the ion exchange resin, which cannot be effectively tested with simulant. Such interactions include organic fouling of the resin and salt precipitation in the column. These effects may affect the shape of the column breakthrough curve. The reduction in column size also may change the shape of the curve, making the individual effects even more difficult to sort out. To simplify the evaluation, the changes due to column size must be either understood or eliminated. This report describes the determination of the column size for actual waste testing that best minimizes the effect of scale-down. This evaluation will provide a theoretical basis for the dimensions of the column. Experimental testing is still required before the final decision can be made. This evaluation will be confined to the study of CS-100 and R-F resins with NCAW simulant and to a limited extent DSSF waste simulant. Only the cesium loading phase has been considered

  4. The Hysteresis Performance and Restoring Force Model for Corroded Reinforced Concrete Frame Columns

    Directory of Open Access Journals (Sweden)

    Guifeng Zhao

    2016-01-01

    Full Text Available A numerical simulation of the hysteresis performance of corroded reinforced concrete (RC frame columns was conducted. Moreover, the results obtained were compared with experimental data. On this basis, a degenerated three-linearity (D-TRI restoring force model was established which could reflect the hysteresis performance of corroded RC frame columns through theoretical analysis and data fitting. Results indicated that the hysteretic bearing capacity of frame columns decreased significantly due to corrosion of the rebar. In view of the characteristics of the hysteresis curve, the plumpness of the hysteresis loop for frame columns decreased and shrinkage increased with increasing rebar corrosion. All these illustrated that the seismic energy dissipation performance of frame columns reduced but their brittleness increased. As for the features of the skeleton curve, the trends for corroded and noncorroded members were basically consistent and roughly corresponded to the features of a trilinear equivalent model. Thereby, the existing Clough hysteresis rule can be used to establish the restoring force model applicable to corroded RC frame columns based on that of the noncorroded RC members. The calculated skeleton curve and hysteresis curve of corroded RC frame columns using the D-TRI model are closer to the experimental results.

  5. Discussion on the Influence of Various Technological Parameters on Jet Grouting Columns Geometry

    Directory of Open Access Journals (Sweden)

    Bzówka Joanna

    2015-06-01

    Full Text Available One of the most popular elements created by using jet grouting technology are columns. During designing such columns, it is a problem of estimating their shape and dimensions. The main factors that influence on columns geometry are soil characteristic and technological parameters. At the frame of Authors scientific research, following technological factors were taken into account: system of jet grouting, injection pressure, dimension of nozzles and rotation speed during injection. In the paper some results of the field tests of jet grouting columns are presented

  6. Stability of embankments over cement deep soil mixing columns

    International Nuclear Information System (INIS)

    Morilla Moar, P.; Melentijevic, S.

    2014-01-01

    The deep soil mixing (DSM) is one of the ground improvement methods used for the construction of embankments over soft soils. DSM column-supported embankments are constructed over soft soils to accelerate its construction, improve embankment stability, increase bearing capacity and control of total and differential settlements. There are two traditional design methods, the Japanese (rigid columns) and the scandinavian (soft and semi-rigid columns). Based on Laboratory analysis and numerical analysis these traditional approaches have been questioned by several authors due to its overestimation of the embankment stability considering that the most common failures types are not assumed. This paper presents a brief review of traditional design methods for embankments on DSM columns constructed in soft soils, studies carried out determine the most likely failure types of DSM columns, methods to decrease the overestimation when using limit equilibrium methods and numerical analysis methods that permit detect appropriate failure modes in DSM columns. Finally a case study was assessed using both limited equilibrium and finite element methods which confirmed the overestimation in the factors of safety on embankment stability over DSM columns. (Author)

  7. Effect of backmixing on pulse column performance

    International Nuclear Information System (INIS)

    Miao, Y.W.

    1979-05-01

    A critical survey of the published literature concerning dispersed phase holdup and longitudinal mixing in pulsed sieve-plate extraction columns has been made to assess the present state-of-the-art in predicting these two parameters, both of which are of critical importance in the development of an accurate mathematical model of the pulse column. Although there are many conflicting correlations of these variables as a function of column geometry, operating conditions, and physical properties of the liquid systems involved it has been possible to develop new correlations which appear to be useful and which are consistent with much of the available data over the limited range of variables most likely to be encountered in plant sized equipment. The correlations developed were used in a stagewise model of the pulse column to predict product concentrations, solute inventory, and concentration profiles in a column for which limited experimental data were available. Reasonable agreement was obtained between the mathematical model and the experimental data. Complete agreement, however, can only be obtained after a correlation for the extraction efficiency has been developed. The correlation of extraction efficiency was beyond the scope of this work

  8. Prediction of the Service Life of a Reinforced Concrete Column under Chloride Environment

    Directory of Open Access Journals (Sweden)

    Mohammad K. Alkam

    2015-01-01

    Full Text Available In the present investigation, service life of a reinforced concrete column exposed to chloride environment has been predicted. This study has been based on numerical simulation of chloride ion diffusion in a concrete column during its anticipated life span. The simulation process has included the concrete cover replacement whenever chloride ion concentration has reached the critical threshold value at the reinforcement surface. Repair scheduling of the concrete column under consideration has been discussed. Effects of the concrete cover thickness and the water cement ratio on the service life of the concrete column at hand have been presented. A new approach for arranging locations of reinforcement steel bars has been introduced. This approach is intended to prolong the service life of the concrete column under consideration against chloride induced corrosion.

  9. Vertebral Column Resection for Rigid Spinal Deformity.

    Science.gov (United States)

    Saifi, Comron; Laratta, Joseph L; Petridis, Petros; Shillingford, Jamal N; Lehman, Ronald A; Lenke, Lawrence G

    2017-05-01

    Broad narrative review. To review the evolution, operative technique, outcomes, and complications associated with posterior vertebral column resection. A literature review of posterior vertebral column resection was performed. The authors' surgical technique is outlined in detail. The authors' experience and the literature regarding vertebral column resection are discussed at length. Treatment of severe, rigid coronal and/or sagittal malalignment with posterior vertebral column resection results in approximately 50-70% correction depending on the type of deformity. Surgical site infection rates range from 2.9% to 9.7%. Transient and permanent neurologic injury rates range from 0% to 13.8% and 0% to 6.3%, respectively. Although there are significant variations in EBL throughout the literature, it can be minimized by utilizing tranexamic acid intraoperatively. The ability to correct a rigid deformity in the spine relies on osteotomies. Each osteotomy is associated with a particular magnitude of correction at a single level. Posterior vertebral column resection is the most powerful posterior osteotomy method providing a successful correction of fixed complex deformities. Despite meticulous surgical technique and precision, this robust osteotomy technique can be associated with significant morbidity even in the most experienced hands.

  10. Interaction diagrams for composite columns exposed to fire

    Directory of Open Access Journals (Sweden)

    Milanović Milivoje

    2014-01-01

    Full Text Available The bearing capacity of the cross section of composite column in fire conditions through changes in the interaction diagram 'bending moment-axialforce' were analyzed in this paper. The M-N interaction diagram presents the relationship between the intensities of the bending moment and the axial force as actions on the column cross section, or the relationship between the design value of the plastic resistance to axial compression of the total cross-section Npl, Rd and the design value of the bending moment resistance Mpl, Rd. It is well known that the temperature increase causes decrease of the load-bearing characteristics of the constitutive materials. This effect directly reflects on the reduction of the axial force and the bending moment that could be accepted by the column cross section. Interaction diagrams for three different types of column cross sections for five different maximal temperatures developed during the fire action were defined. For that purpose the software package SAFIR was used. The columns, materials and load characteristics, as well as all other terms and conditions, were taken in accordance with the relevant Eurocodes and the theory of composite columns.

  11. Carrier effect on separation efficiency of the column in reversed-phase partition chromatography

    International Nuclear Information System (INIS)

    Pszonicka, M.; Siekierski, S.

    1972-01-01

    Chromatographic columns were filled with carriers of diatomaceous earth type (Hyflo Super Cell, and Celite 545) of large pores, and two microporous silica gels respectively. These columns were used for the separation of europium and gadolinium by reversed-phase partition chromatography in the system: stationary phase-diethylhexylphosphoric acid (HDEHP) mobile phase-0.4 N nitric acid. In each case the separation of the above mentioned elements was achieved. The plate height that characterizes separation efficiency of the column, decreases with the decrease of particle diameter of the carrier. Best columns were obtained from carriers of large pores (Hyflo Super Cell and Celite 545) for which plate hights below 0.1 mm could be achieved. Columns filled with microporous silica gels showed plate heights of 0.2-0.3 mm. (author)

  12. Quantitation of promethazine and metabolites in urine samples using on-line solid-phase extraction and column-switching

    Science.gov (United States)

    Song, Q.; Putcha, L.; Harm, D. L. (Principal Investigator)

    2001-01-01

    A chromatographic method for the quantitation of promethazine (PMZ) and its three metabolites in urine employing on-line solid-phase extraction and column-switching has been developed. The column-switching system described here uses an extraction column for the purification of PMZ and its metabolites from a urine matrix. The extraneous matrix interference was removed by flushing the extraction column with a gradient elution. The analytes of interest were then eluted onto an analytical column for further chromatographic separation using a mobile phase of greater solvent strength. This method is specific and sensitive with a range of 3.75-1400 ng/ml for PMZ and 2.5-1400 ng/ml for the metabolites promethazine sulfoxide, monodesmethyl promethazine sulfoxide and monodesmethyl promethazine. The lower limits of quantitation (LLOQ) were 3.75 ng/ml with less than 6.2% C.V. for PMZ and 2.50 ng/ml with less than 11.5% C.V. for metabolites based on a signal-to-noise ratio of 10:1 or greater. The accuracy and precision were within +/- 11.8% in bias and not greater than 5.5% C.V. in intra- and inter-assay precision for PMZ and metabolites. Method robustness was investigated using a Plackett-Burman experimental design. The applicability of the analytical method for pharmacokinetic studies in humans is illustrated.

  13. Recovery of deuterium from H-D gas mixture by thermal diffusion in a multi-concentric-tube column device of fixed total sum of column heights with transverse sampling streams

    International Nuclear Information System (INIS)

    Yeh, H.-M.

    2010-01-01

    The effect of the increment in the number of concentric-tube thermal diffusion columns on the recovery of deuterium from H 2 -HD-D 2 system with fixed total sum of column heights, has been investigated. The equations for predicting the degrees of separation in single-column, double-column and triple-column devices have been derived. Considerable improvement in recovery can be achieved if a multi-column device with larger number of column is employed, instead of a single-column device with column height equal to the same total sum of column heights, especially for the case of higher flow-rate operation and larger total sum of column heights.

  14. A revised 3-column classification approach for the surgical planning of extended lateral tibial plateau fractures.

    Science.gov (United States)

    Hoekstra, H; Kempenaers, K; Nijs, S

    2017-10-01

    Variable angle locking compression plates allow for lateral buttress and support of the posterolateral joint surface of tibial plateau fractures. This gives room for improvement of the surgical 3-column classification approach. Our aim was to revise and validate the 3-column classification approach to better guide the surgical planning of tibial plateau fractures extending into the posterolateral corner. In contrast to the 3-column classification approach, in the revised approach the posterior border of the lateral column in the revised approach lies posterior instead of anterior of the fibula. According to the revised 3-column classification approach, extended lateral column fractures are defined as single lateral column fractures extending posteriorly into the posterolateral corner. CT-images of 36 patients were reviewed and classified twice online according to Schatzker and revised 3-column classification approach by five observers. The intraobserver reliability was calculated using the Cohen's kappa and the interobserver reliability was calculated using the Fleiss' kappa. The intraobserver reliability showed substantial agreement according to Landis and Koch for both Schatzker and the revised 3-column classification approach (0.746 vs. 0.782 p = 0.37, Schatzker vs. revised 3-column, respectively). However, the interobserver reliability of the revised 3-column classification approach was significantly higher as compared to the Schatzker classification (0.531 vs. 0.669 p column, respectively). With the introduction of variable angle locking compression plates, the revised 3-column classification approach is a very helpful tool in the preoperative surgical planning of tibial plateau fractures, in particular, lateral column fractures that extend into the posterolateral corner. The revised 3-column classification approach is rather a practical supplement to the Schatzker classification. It has a significantly higher interobserver reliability as compared to the

  15. Multi-Column Experimental Test Bed for Xe/Kr Separation

    International Nuclear Information System (INIS)

    Greenhalgh, Mitchell Randy; Garn, Troy Gerry; Welty, Amy Keil; Lyon, Kevin Lawrence; Watson, Tony Leroy

    2015-01-01

    Previous research studies have shown that INL-developed engineered form sorbents are capable of capturing both Kr and Xe from various composite gas streams. The previous experimental test bed provided single column testing for capacity evaluations over a broad temperature range. To advance research capabilities, the employment of an additional column to study selective capture of target species to provide a defined final gas composition for waste storage was warranted. The second column addition also allows for compositional analyses of the final gas product to provide for final storage determinations. The INL krypton capture system was modified by adding an additional adsorption column in order to create a multi-column test bed. The purpose of this modification was to investigate the separation of xenon from krypton supplied as a mixed gas feed. The extra column was placed in a Stirling Ultra-low Temperature Cooler, capable of controlling temperatures between 190 and 253K. Additional piping and valves were incorporated into the system to allow for a variety of flow path configurations. The new column was filled with the AgZ-PAN sorbent which was utilized as the capture medium for xenon while allowing the krypton to pass through. The xenon-free gas stream was then routed to the cryostat filled with the HZ-PAN sorbent to capture the krypton at 191K. Selectivities of xenon over krypton were determined using the new column to verify the system performance and to establish the operating conditions required for multi-column testing. Results of these evaluations verified that the system was operating as designed and also demonstrated that AgZ-PAN exhibits excellent selectivity for xenon over krypton in air at or near room temperature. Two separation tests were performed utilizing a feed gas consisting of 1000 ppmv xenon and 150 ppmv krypton with the balance being made up of air. The AgZ-PAN temperature was held at 295 or 253K while the HZ-PAN was held at 191K for both

  16. The relation between the column density structures and the magnetic field orientation in the Vela C molecular complex

    Science.gov (United States)

    Soler, J. D.; Ade, P. A. R.; Angilè, F. E.; Ashton, P.; Benton, S. J.; Devlin, M. J.; Dober, B.; Fissel, L. M.; Fukui, Y.; Galitzki, N.; Gandilo, N. N.; Hennebelle, P.; Klein, J.; Li, Z.-Y.; Korotkov, A. L.; Martin, P. G.; Matthews, T. G.; Moncelsi, L.; Netterfield, C. B.; Novak, G.; Pascale, E.; Poidevin, F.; Santos, F. P.; Savini, G.; Scott, D.; Shariff, J. A.; Thomas, N. E.; Tucker, C. E.; Tucker, G. S.; Ward-Thompson, D.

    2017-07-01

    We statistically evaluated the relative orientation between gas column density structures, inferred from Herschel submillimetre observations, and the magnetic field projected on the plane of sky, inferred from polarized thermal emission of Galactic dust observed by the Balloon-borne Large-Aperture Submillimetre Telescope for Polarimetry (BLASTPol) at 250, 350, and 500 μm, towards the Vela C molecular complex. First, we find very good agreement between the polarization orientations in the three wavelength-bands, suggesting that, at the considered common angular resolution of 3.´0 that corresponds to a physical scale of approximately 0.61 pc, the inferred magnetic field orientation is not significantly affected by temperature or dust grain alignment effects. Second, we find that the relative orientation between gas column density structures and the magnetic field changes progressively with increasing gas column density, from mostly parallel or having no preferred orientation at low column densities to mostly perpendicular at the highest column densities. This observation is in agreement with previous studies by the Planck collaboration towards more nearby molecular clouds. Finally, we find a correspondencebetween (a) the trends in relative orientation between the column density structures and the projected magnetic field; and (b) the shape of the column density probability distribution functions (PDFs). In the sub-regions of Vela C dominated by one clear filamentary structure, or "ridges", where the high-column density tails of the PDFs are flatter, we find a sharp transition from preferentially parallel or having no preferred relative orientation at low column densities to preferentially perpendicular at highest column densities. In the sub-regions of Vela C dominated by several filamentary structures with multiple orientations, or "nests", where the maximum values of the column density are smaller than in the ridge-like sub-regions and the high-column density

  17. Artificial neural network modelling of retention of pesticides in various octadecylsiloxane-bonded reversed-phase columns and water-acetonitrile mobile phase

    Energy Technology Data Exchange (ETDEWEB)

    D' Archivio, Angelo Antonio, E-mail: angeloantonio.darchivio@univaq.it [Dipartimento di Chimica, Ingegneria Chimica e Materiali, Universita degli Studi di L' Aquila, Via Vetoio, 67010 Coppito, L' Aquila (Italy); Maggi, Maria Anna; Mazzeo, Pietro; Ruggieri, Fabrizio [Dipartimento di Chimica, Ingegneria Chimica e Materiali, Universita degli Studi di L' Aquila, Via Vetoio, 67010 Coppito, L' Aquila (Italy)

    2009-07-30

    Previously, retention of 26 pesticides in the reversed-phase column Gemini (Phenomenex) and water-acetonitrile mobile phase was modelled using a feed-forward artificial neural network (ANN) learned by error back-propagation, accounting for both the effect of solute structure and mobile phase composition. To this end, log K{sub ow} of solutes and four quantum chemical molecular descriptors (the dipole moment, the mean polarizability, the anisotropy of the polarizability and an hydrogen-bonding descriptor based on the atomic charges located on the acid and basic functional groups) and acetonitrile % (v/v) in the eluent (%ACN) were used as ANN inputs. The above ANN-based approach is here tested on further five similar octadecylsiloxane-bonded columns in water-acetonitrile mobile phase within the %ACN range 30-70%. A quite good predictive performance evaluated on three external solutes in the whole %ACN range is observed, prediction errors being lower than {+-}0.1 log k units or slightly higher although still within {+-}0.15 log k units. On the other hand, multilinear regression used in place of ANN provides a more diffuse and non-uniform residual distribution for all the investigated columns. ANN multiple-column retention prediction is attempted by adding to the above variables a column descriptor defined as the average retention of calibration solutes extrapolated to 100% water. This more general model is built using 16 solutes and five 5-{mu}m columns in calibration, while its predictive performance is tested on the remaining 10 compounds. Under these conditions, prediction errors are generally within {+-}0.2 log k units regardless of the kind of column. The possibility of cross-column prediction is evaluated by column leave-one-out cross-validation within the five 5-{mu}m stationary phases and on a 4-{mu}m external column. This analysis reveals that accuracy of retention prediction for unknown solutes in unknown columns is acceptable provided that the external

  18. Artificial neural network modelling of retention of pesticides in various octadecylsiloxane-bonded reversed-phase columns and water-acetonitrile mobile phase

    International Nuclear Information System (INIS)

    D'Archivio, Angelo Antonio; Maggi, Maria Anna; Mazzeo, Pietro; Ruggieri, Fabrizio

    2009-01-01

    Previously, retention of 26 pesticides in the reversed-phase column Gemini (Phenomenex) and water-acetonitrile mobile phase was modelled using a feed-forward artificial neural network (ANN) learned by error back-propagation, accounting for both the effect of solute structure and mobile phase composition. To this end, log K ow of solutes and four quantum chemical molecular descriptors (the dipole moment, the mean polarizability, the anisotropy of the polarizability and an hydrogen-bonding descriptor based on the atomic charges located on the acid and basic functional groups) and acetonitrile % (v/v) in the eluent (%ACN) were used as ANN inputs. The above ANN-based approach is here tested on further five similar octadecylsiloxane-bonded columns in water-acetonitrile mobile phase within the %ACN range 30-70%. A quite good predictive performance evaluated on three external solutes in the whole %ACN range is observed, prediction errors being lower than ±0.1 log k units or slightly higher although still within ±0.15 log k units. On the other hand, multilinear regression used in place of ANN provides a more diffuse and non-uniform residual distribution for all the investigated columns. ANN multiple-column retention prediction is attempted by adding to the above variables a column descriptor defined as the average retention of calibration solutes extrapolated to 100% water. This more general model is built using 16 solutes and five 5-μm columns in calibration, while its predictive performance is tested on the remaining 10 compounds. Under these conditions, prediction errors are generally within ±0.2 log k units regardless of the kind of column. The possibility of cross-column prediction is evaluated by column leave-one-out cross-validation within the five 5-μm stationary phases and on a 4-μm external column. This analysis reveals that accuracy of retention prediction for unknown solutes in unknown columns is acceptable provided that the external column is not very

  19. Sleep on the right side-Get cancer on the left?

    Science.gov (United States)

    Hallberg, Orjan; Johansson, Olle

    2010-06-01

    . Hallberg, A theory and model to explain the skin melanoma epidemic, Melanoma Res. 16 (2006) 115-118; O. Hallberg, A reduced repair efficiency can explain increasing melanoma rates, Eur. J. Cancer Prev. 17 (2008) 147-152; O. Hallberg, O. Johansson, Melanoma incidence and frequency modulation (FM) broadcasting, Arch. Environ. Health 57 (2002) 32-40; O. Hallberg, O. Johansson, FM broadcasting exposure time and malignant melanoma incidence, Electromagn. Biol. Med. 24 (2005) 1-8; O. Hallberg, Radio TV towers linked to increased risk of melanoma, Report, available at: http://foodconsumer.org/7777/8888/C_ancer_31/120907442007_Exclusive_report_Radio_TV_towers_linked_to_increased_risk_of_melanoma.shtml, 2007 (accessed 2007)]. Geographical areas covered by several transmitters show higher incidences of melanoma than areas covered by one transmitter. Here we show that a high prevalence of breast cancer and melanoma on the left side of the body may be a logical consequence of sleeping in beds having mattresses containing wave-reflecting metal springs. We found that people tend to sleep for longer periods on their right side, apparently to avoid disturbance by the heartbeat. This puts the left side farther away from the field-attenuating influence of the metal springs in the mattress; thus the left side will spend, on average, more time exposed to stronger combined fields from incident and reflected waves. This hypothesis may also explain why body parts farthest away from the mattress (trunk and upper arms for men; lower limbs and hips for women) have higher melanoma rates than the sun-exposed face area. The implications of this study should promote a critical consideration of population exposure to electromagnetic fields, especially during the night. Copyright © 2009 Elsevier Ireland Ltd. All rights reserved.

  20. Convolutional Codes with Maximum Column Sum Rank for Network Streaming

    OpenAIRE

    Mahmood, Rafid; Badr, Ahmed; Khisti, Ashish

    2015-01-01

    The column Hamming distance of a convolutional code determines the error correction capability when streaming over a class of packet erasure channels. We introduce a metric known as the column sum rank, that parallels column Hamming distance when streaming over a network with link failures. We prove rank analogues of several known column Hamming distance properties and introduce a new family of convolutional codes that maximize the column sum rank up to the code memory. Our construction invol...

  1. Enrichment of heavy water in thermal-diffusion columns connected in series

    International Nuclear Information System (INIS)

    Yeh, Ho-Ming; Chen, Liu Yi

    2009-01-01

    The separation equations for enrichment of heavy water from water isotope mixture by thermal diffusion in multiple columns connected in series, have been derived based on one column design developed in previous work. The improvement in separation is achievable by operating in a double-column device, instead of in a single-column device, with the same total column length. It is also found that further improvement in separation is obtainable if a triple-column device is employed, except for operating under small total column length and low flow rate.

  2. Thermal Modeling Analysis Of CST Media In The Small Column Ion Exchange Project

    International Nuclear Information System (INIS)

    Lee, S.

    2010-01-01

    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. One salt processing scenario includes the transport of the loaded (and possibly ground) CST media to the treatment tank floor. Therefore, additional thermal modeling calculations were conducted using a three-dimensional approach to evaluate temperature distributions for the entire in-tank domain including distribution of the spent CST media either as a mound or a flat layer on the tank floor. These calculations included mixtures of CST with HLW sludge or loaded Monosodium Titanate (MST) media used for strontium/actinide sorption. 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

  3. Polydopamine-coated open tubular column for the separation of proteins by capillary electrochromatography.

    Science.gov (United States)

    Xiao, Xing; Wang, Wentao; Chen, Jia; Jia, Li

    2015-08-01

    The separation and determination of proteins in food is an important aspect in food industry. Inspired by the self-polymerization of dopamine under alkaline conditions and the natural adhesive properties of polydopamine, in this paper, a simple and economical method was developed for the preparation of polydopamine-coated open tubular column, in which ammonium persulfate was used as the source of oxygen to induce and facilitate the polymerization of dopamine to form polydopamine. In comparison with a naked fused-silica capillary, the direction and magnitude of the electro-osmotic flow of the as-prepared polydopamine-coated open tubular column could be manipulated by varying the pH values of background solutions due to the existence of amine and phenolic hydroxyl groups on polydopamine coating. The surface morphology of the polydopamine-coated open tubular column was studied by scanning electron microscopy, and the thickness of polydopamine coating was 106 nm. The performance of the polydopamine-coated open tubular column was validated by analysis of proteins. The relative standard deviations of migration times of proteins representing run-to-run, day-to-day, and column-to-column were less than 3.5%. In addition, the feasibility of the polydopamine-coated open tubular column for real samples was verified by the separation of proteins in chicken egg white and pure milk. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  4. Mathematical solution of the stone column effect on the load bearing capacity and settlement using numerical analysis

    Science.gov (United States)

    Madun, A.; Meghzili, S. A.; Tajudin, SAA; Yusof, M. F.; Zainalabidin, M. H.; Al-Gheethi, A. A.; Dan, M. F. Md; Ismail, M. A. M.

    2018-04-01

    The most important application of various geotechnical construction techniques is for ground improvement. Many soil improvement project had been developed due to the ongoing increase in urban and industrial growth and the need for greater access to lands. Stone columns are one of the best effective and feasible techniques for soft clay soil improvement. Stone columns increase the bearing capacity and reduce the settlement of soil. Finite element analyses were performed using the program PLAXIS 2D. An elastic-perfectly plastic constitutive relation, based on the Mohr–Coulomb criterion, governs the soft clay and stone column behaviour. This paper presents on how the response surface methodology (RSM) software is used to optimize the effect of the diameters and lengths of column on the load bearing capacity and settlement of soft clay. Load tests through the numerical modelling using Plaxis 2D were carried out on the loading plate at 66 mm. Stone column load bearing capacity increases with the increasing diameter of the column and settlement decreases with the increasing length of the column. Results revealed that the bigger column diameter, the higher load bearing capacity of soil while the longer column length, the lower settlement of soil. However, the optimum design of stone column was varied with each factor (diameter and length) separately for improvement.

  5. The evolutionary psychology of left and right: costs and benefits of lateralization.

    Science.gov (United States)

    Vallortigara, Giorgio

    2006-09-01

    Why do the left and right sides of the vertebrate brain play different functions? Having a lateralized brain, in which each hemisphere carries out different functions, is ubiquitous among vertebrates. The different specialization of the left and right side of the brain may increase brain efficiency--and some evidence for that is reported here. However, lateral biases due to brain lateralization (such as preferences in the use of a limb or, in animals with laterally placed eyes, of a visual hemifield) usually occur at the population level, with most individuals showing similar direction of bias. Individual brain efficiency does not require the alignment of lateralization in the population. Why then are not left--and right-type individuals equally common? Not only humans, but most vertebrates show a similar pattern. For instance, in the paper I report evidence that most toads, chickens, and fish react faster when a predator approaches from the left. I argue that invoking individual brain efficiency (lateralization may increase fitness), evolutionary chance or direct genetic mechanisms cannot explain this widespread pattern. Instead, using concepts from mathematical theory of games, I show that alignment of lateralization at the population level may arise as an "evolutionarily stable strategy" when individually asymmetrical organisms must coordinate their behavior with that of other asymmetrical organisms. Thus, the population structure of lateralization may result from genes specifying the direction of asymmetries which have been selected under "social" pressures.

  6. Dynamic effects on cyclotron scattering in pulsar accretion columns

    International Nuclear Information System (INIS)

    Brainerd, J.J.; Meszaros, P.

    1991-01-01

    A resonant scattering model for photon reprocessing in a pulsar accretion column is presented. The accretion column is optically thin to Thomson scattering and optically thick to resonant scattering at the cyclotron frequency. Radiation from the neutron star surface propagates freely through the column until the photon energy equals the local cyclotron frequency, at which point the radiation is scattered, much of it back toward the star. The radiation pressure in this regime is insufficient to stop the infall. Some of the scattered radiation heats the stellar surface around the base of the column, which adds a softer component to the spectrum. The partial blocking by the accretion column of X-rays from the surface produces a fan beam emission pattern. X-rays above the surface cyclotron frequency freely escape and are characterized by a pencil beam. Gravitational light bending produces a pencil beam pattern of column-scattered radiation in the antipodal direction, resulting in a strongly angle-dependent cyclotron feature. 31 refs

  7. Investigating the Functional Utility of the Left Parietal ERP Old/New Effect: Brain Activity Predicts within But Not between Participant Variance in Episodic Recollection

    Directory of Open Access Journals (Sweden)

    Catherine A. MacLeod

    2017-12-01

    Full Text Available A success story within neuroimaging has been the discovery of distinct neural correlates of episodic retrieval, providing insight into the processes that support memory for past life events. Here we focus on one commonly reported neural correlate, the left parietal old/new effect, a positive going modulation seen in event-related potential (ERP data that is widely considered to index episodic recollection. Substantial evidence links changes in the size of the left parietal effect to changes in remembering, but the precise functional utility of the effect remains unclear. Here, using forced choice recognition of verbal stimuli, we present a novel population level test of the hypothesis that the magnitude of the left parietal effect correlates with memory performance. We recorded ERPs during old/new recognition, source accuracy and Remember/Know/Guess tasks in two large samples of healthy young adults, and successfully replicated existing within participant modulations of the magnitude of the left parietal effect with recollection. Critically, however, both datasets also show that across participants the magnitude of the left parietal effect does not correlate with behavioral measures of memory – including both subjective and objective estimates of recollection. We conclude that in these tasks, and across this healthy young adult population, the generators of the left parietal ERP effect do not index performance as expected. Taken together, these novel findings provide important constraints on the functional interpretation of the left parietal effect, suggesting that between group differences in the magnitude of old/new effects cannot always safely be used to infer differences in recollection.

  8. Permanent magnet finger-size scanning electron microscope columns

    Energy Technology Data Exchange (ETDEWEB)

    Nelliyan, K., E-mail: elenk@nus.edu.sg [Department of Electrical and Computer Engineering, National University of Singapore, 4 Engineering Drive 3, Singapore 117576 (Singapore); Khursheed, A. [Department of Electrical and Computer Engineering, National University of Singapore, 4 Engineering Drive 3, Singapore 117576 (Singapore)

    2011-07-21

    This paper presents permanent magnet scanning electron microscope (SEM) designs for both tungsten and field emission guns. Each column makes use of permanent magnet technology and operates at a fixed primary beam voltage. A prototype column operating at a beam voltage of 15 kV was made and tested inside the specimen chamber of a conventional SEM. A small electrostatic stigmator unit and dedicated scanning coils were integrated into the column. The scan coils were wound directly around the objective lens iron core in order to reduce its size. Preliminary experimental images of a test grid specimen were obtained through the prototype finger-size column, demonstrating that it is in principle feasible.

  9. Permanent magnet finger-size scanning electron microscope columns

    International Nuclear Information System (INIS)

    Nelliyan, K.; Khursheed, A.

    2011-01-01

    This paper presents permanent magnet scanning electron microscope (SEM) designs for both tungsten and field emission guns. Each column makes use of permanent magnet technology and operates at a fixed primary beam voltage. A prototype column operating at a beam voltage of 15 kV was made and tested inside the specimen chamber of a conventional SEM. A small electrostatic stigmator unit and dedicated scanning coils were integrated into the column. The scan coils were wound directly around the objective lens iron core in order to reduce its size. Preliminary experimental images of a test grid specimen were obtained through the prototype finger-size column, demonstrating that it is in principle feasible.

  10. Aspartic acid incorporated monolithic columns for affinity glycoprotein purification.

    Science.gov (United States)

    Armutcu, Canan; Bereli, Nilay; Bayram, Engin; Uzun, Lokman; Say, Rıdvan; Denizli, Adil

    2014-02-01

    Novel aspartic acid incorporated monolithic columns were prepared to efficiently affinity purify immunoglobulin G (IgG) from human plasma. The monolithic columns were synthesised in a stainless steel HPLC column (20 cm × 5 mm id) by in situ bulk polymerisation of N-methacryloyl-L-aspartic acid (MAAsp), a polymerisable derivative of L-aspartic acid, and 2-hydroxyethyl methacrylate (HEMA). Monolithic columns [poly(2-hydroxyethyl methacrylate-N-methacryloyl-L-aspartic acid) (PHEMAsp)] were characterised by swelling studies, Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). The monolithic columns were used for IgG adsorption/desorption from aqueous solutions and human plasma. The IgG adsorption depended on the buffer type, and the maximum IgG adsorption from aqueous solution in phosphate buffer was 0.085 mg/g at pH 6.0. The monolithic columns allowed for one-step IgG purification with a negligible capacity decrease after ten adsorption-desorption cycles. Copyright © 2013 Elsevier B.V. All rights reserved.

  11. Hollow-Core FRP–Concrete–Steel Bridge Columns under Torsional Loading

    Directory of Open Access Journals (Sweden)

    Sujith Anumolu

    2017-11-01

    Full Text Available This paper presents the behavior of hollow-core fiber-reinforced polymer–concrete–steel (HC-FCS columns under cyclic torsional loading combined with constant axial load. The HC-FCS consists of an outer fiber-reinforced polymer (FRP tube and an inner steel tube, with a concrete shell sandwiched between the two tubes. The FRP tube was stopped at the surface of the footing, and provided confinement to the concrete shell from the outer direction. The steel tube was embedded into the footing to a length of 1.8 times the diameter of the steel tube. The longitudinal and transversal reinforcements of the column were provided by the steel tube only. A large-scale HC-FCS column with a diameter of 24 in. (610 mm and applied load height of 96 in. (2438 mm with an aspect ratio of four was investigated during this study. The study revealed that the torsional behavior of the HC-FCS column mainly depended on the stiffness of the steel tube and the interactions among the column components (concrete shell, steel tube, and FRP tube. A brief comparison of torsional behavior was made between the conventional reinforced concrete columns and the HC-FCS column. The comparison illustrated that both column types showed high initial stiffness under torsional loading. However, the HC-FCS column maintained the torsion strength until a high twist angle, while the conventional reinforced concrete column did not.

  12. Functional outcome of intra-articular tibial plateau fractures: the impact of posterior column fractures.

    Science.gov (United States)

    van den Berg, Juriaan; Reul, Maike; Nunes Cardozo, Menno; Starovoyt, Anastasiya; Geusens, Eric; Nijs, Stefaan; Hoekstra, Harm

    2017-09-01

    INTRODUCTION: Although regularly ignored, there is growing evidence that posterior tibial plateau fractures affect the functional outcome. The goal of this study was to assess the incidence of posterior column fractures and its impact on functional outcome and general health status. We aimed to identify all clinical variables that influence the outcome and improve insights in the treatment strategies. A retrospective cohort study including 218 intra-articular tibial plateau fractures was conducted. All fractures were reclassified and applied treatment was assessed according to the updated three-column concept. Relevant demographic and clinical variables were studied. The patient reported outcome was assessed using the Knee injury and Osteoarthritis Outcome Score (KOOS). Median follow-up was 45.5 (IQR 24.9-66.2) months. Significant outcome differences between operatively and non-operatively treated patients were found for all KOOS subscales. The incidence of posterior column fractures was 61.9%. Posterior column fractures, sagittal malalignment and an increased complication rate were associated with poor outcome. Patients treated according to the updated three-column concept, showed significantly better outcome scores than those patients who were not. We could not demonstrate the advantage of posterior column fracture fixation, due to a limited patient size. Our data indicates that implementation of the updated three-column classification concept may improve the surgical outcome of tibial plateau fractures. Failure to recognize posterior column fractures may lead to inappropriate utilization of treatment techniques. The current concept allows us to further substantiate the importance of reduction and fixation of posterior column fractures with restoration of the sagittal alignment. 3.

  13. Hydrogen peroxide stabilization in one-dimensional flow columns

    Science.gov (United States)

    Schmidt, Jeremy T.; Ahmad, Mushtaque; Teel, Amy L.; Watts, Richard J.

    2011-09-01

    Rapid hydrogen peroxide decomposition is the primary limitation of catalyzed H 2O 2 propagations in situ chemical oxidation (CHP ISCO) remediation of the subsurface. Two stabilizers of hydrogen peroxide, citrate and phytate, were investigated for their effectiveness in one-dimensional columns of iron oxide-coated and manganese oxide-coated sand. Hydrogen peroxide (5%) with and without 25 mM citrate or phytate was applied to the columns and samples were collected at 8 ports spaced 13 cm apart. Citrate was not an effective stabilizer for hydrogen peroxide in iron-coated sand; however, phytate was highly effective, increasing hydrogen peroxide residuals two orders of magnitude over unstabilized hydrogen peroxide. Both citrate and phytate were effective stabilizers for manganese-coated sand, increasing hydrogen peroxide residuals by four-fold over unstabilized hydrogen peroxide. Phytate and citrate did not degrade and were not retarded in the sand columns; furthermore, the addition of the stabilizers increased column flow rates relative to unstabilized columns. These results demonstrate that citrate and phytate are effective stabilizers of hydrogen peroxide under the dynamic conditions of one-dimensional columns, and suggest that citrate and phytate can be added to hydrogen peroxide before injection to the subsurface as an effective means for increasing the radius of influence of CHP ISCO.

  14. Mathematical modeling of alcohol distillation columns

    Directory of Open Access Journals (Sweden)

    Ones Osney Pérez

    2011-04-01

    Full Text Available New evaluation modules are proposed to extend the scope of a modular simulator oriented to the sugar cane industry, called STA 4.0, in a way that it can be used to carry out x calculation and analysis in ethanol distilleries. Calculation modules were developed for the simulation of the columns that are combined in the distillation area. Mathematical models were supported on materials and energy balances, equilibrium relations and thermodynamic properties of the ethanol-water system. Ponchon-Savarit method was used for the evaluation of the theoretical stages in the columns. A comparison between the results using Ponchon- Savarit method and those obtained applying McCabe-Thiele method was done for a distillation column. These calculation modules for ethanol distilleries were applied to a real case for validation.

  15. Revised Thermal Analysis of LANL Ion Exchange Column

    Energy Technology Data Exchange (ETDEWEB)

    Laurinat, J

    2006-04-11

    This document updates a previous calculation of the temperature distributions in a Los Alamos National Laboratory (LANL) ion exchange column.1 LANL operates two laboratory-scale anion exchange columns, in series, to extract Pu-238 from nitric acid solutions. The Defense Nuclear Facilities Safety Board has requested an updated analysis to calculate maximum temperatures for higher resin loading capacities obtained with a new formulation of the Reillex HPQ anion exchange resin. The increased resin loading capacity will not exceed 118 g plutonium per L of resin bed. Calculations were requested for normal operation of the resin bed at the minimum allowable solution feed rate of 30 mL/min and after an interruption of flow at the end of the feed stage, when one of the columns is fully loaded. The object of the analysis is to demonstrate that the decay heat from the Pu-238 will not cause resin bed temperatures to increase to a level where the resin significantly degrades. At low temperatures, resin bed temperatures increase primarily due to decay heat. At {approx}70 C a Low Temperature Exotherm (LTE) resulting from the reaction between 8-12 M HNO{sub 3} and the resin has been observed. The LTE has been attributed to an irreversible oxidation of pendant ethyl benzene groups at the termini of the resin polymer chains by nitric acid. The ethyl benzene groups are converted to benzoic acid moities. The resin can be treated to permanently remove the LTE by heating a resin suspension in 8M HNO{sub 3} for 30-45 minutes. No degradation of the resin performance is observed after the LTE removal treatment. In fact, heating the resin in boiling ({approx}115-120 C) 12 M HNO{sub 3} for 3 hr displays thermal stability analogous to resin that has been treated to remove the LTE. The analysis is based on a previous study of the SRS Frames Waste Recovery (FWR) column, performed in support of the Pu-238 production campaign for NASA's Cassini mission. In that study, temperature transients

  16. One hand or the other? Effector selection biases in right and left handers.

    Science.gov (United States)

    Main, Julie C; Carey, David P

    2014-11-01

    Much debate in the handedness literature has centred on the relative merits of questionnaire-based measures assessing hand preference versus simple movement tasks such as peg moving or finger tapping, assessing hand performance. A third paradigm has grown in popularity, which assesses choices by participants when either hand could be used to execute movements. These newer measures may be useful in predicting possible "reversed" asymmetries in proportions of non-right handed ("adextral") people. In the current studies we examine hand choice in large samples of dextral (right handed) and adextral participants. Unlike in some previous experiments on choice, we found that left handers were as biased towards their dominant hand as were right handers, for grasping during a puzzle-making task (study 1). In a second study, participants had to point to either of two suddenly appearing targets with one hand or the other. In study 2, left handers were not significantly less one handed than their right-handed counterparts as in study 1. In a final study, we used random effects meta analysis to summarise the possible differences in hand choice between left handers and right handers across all hand choice studies published to date. The meta analysis suggests that right handers use their dominant hand 12.5% more than left handers favour their dominant hand (with 95% confidence that the real difference lies between 7% and 18%). These last results suggest that our two experiments reported here may represent statistical Type 2 errors. This mean difference may be related to greater left hemispheric language and praxic laterality in right handers. Nevertheless, more data are needed regarding the precise proportions of left and right handers who favour their preferred hands for different tasks. Copyright © 2014 Elsevier Ltd. All rights reserved.

  17. The choice of surgical approach in the treatment of two-column acetabular fractures

    Directory of Open Access Journals (Sweden)

    A. A. Grin’

    2014-01-01

    Full Text Available The study aimed a comparison of treatment results in patients with two-column acetabular fractures (AO, Type C when using different operative approaches: ilioinguinal (12, Y-type (16 and a combination of posterior-lateral and ilioinguinal approaches (3. Surgical treatment was carried out not later than 3 weeks after injury. The joint congruence was reached in all the cases. The operative time, blood loss, complications, long-term results of treatment were evaluated. The study showed the effectiveness of ilioinguinal approach in case of the simple two-column fractures. When treating patients with complex fractures of the anterior column, the authors found no significant difference in operative time and intraoperative blood loss between the cases of V-type and combined approaches. In patients with two-column fractures accompanied with posterior wall lesion the time of surgery was significantly lower when using the Y-shaped approach as against the two different approaches.

  18. Dopamine-imprinted monolithic column for capillary electrochromatography.

    Science.gov (United States)

    Aşır, Süleyman; Sarı, Duygu; Derazshamshir, Ali; Yılmaz, Fatma; Şarkaya, Koray; Denizli, Adil

    2017-11-01

    A dopamine-imprinted monolithic column was prepared and used in capillary electrochromatography as stationary phase for the first time. Dopamine was selectively separated from aqueous solution containing the competitor molecule norepinephrine, which is similar in size and shape to the template molecule. Morphology of the dopamine-imprinted column was observed by scanning electron microscopy. The influence of the organic solvent content of mobile phase, applied pressure and pH of the mobile phase on the recognition of dopamine by the imprinted monolithic column has been evaluated, and the imprinting effect in the dopamine-imprinted monolithic polymer was verified. Developed dopamine-imprinted monolithic column resulted in excellent separation of dopamine from structurally related competitor molecule, norepinephrine. Separation was achieved in a short period of 10 min, with the electrophoretic mobility of 5.81 × 10 -5  m 2 V -1 s -1 at pH 5.0 and 500 mbar pressure. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  19. Technical contribution to the project and operation of pulsed columns

    International Nuclear Information System (INIS)

    Kromek, I.B.; Ikuta, A.

    1976-01-01

    Characteristics and factors that affect the performance of pulse columms used in the purification of metals as thorium, uranium and plutonium are described. The pulse generator and the control instrumentation of these columns are also described. This report is based mainly in the works made by Richardson and Platt and adaptations realized in the project and instalation of the first compound extraction-scrub pulse column in the CEQ/IEA (Sao Paulo, Brazil) [pt

  20. Dynamics and Control of Distillation Columns - A Critical Survey

    Directory of Open Access Journals (Sweden)

    Sigurd Skogestad

    1997-07-01

    Full Text Available Distillation column dynamics and control have been viewed by many as a very mature or even dead field. However, as is discussed in this paper significant new results have appeared over the last 5-10 years. These results include multiple steady states and instability in simple columns with ideal thermodynamics (which was believed to be impossible, the understanding of the difference between various control configurations and the systematic transformation between these, the feasibility of using the distillate-bottom structure, for control (which was believed to be impossible, the importance of flow dynamics for control studies, the fundamental problems in identifying models from open-loops responses, the use of simple regression estimators to estimate composition from temperatures, and an improved general understanding of the dynamic behavior of distillation columns which includes a better understanding of the fundamental difference between internal and external flow, simple formulas for estimating the dominant time constant, and a derivation of the linearizing effect of logarithmic transformations. These issues apply to all columns, even for ideal mixtures and simple columns with only two products. In addition, there have been significant advances for cases with complex thermodynamics and complex column configurations. These include the behavior and control of azeotropic distillation columns, and the possible complex dynamics of nonideal mixtures and of interlinked columns. However, both for the simple and more complex cases there are still a number of areas where further research is needed.

  1. Miniaturized Laser Heterodyne Radiometer (LHR) for Measurements of Greenhouse Gases in the Atmospheric Column

    Science.gov (United States)

    Steel, Emily; McLinden, Matthew

    2012-01-01

    This passive laser heterodyne radiometer (LHR) instrument simultaneously measures multiple trace gases in the atmospheric column including carbon dioxide (CO2) and methane (CH4), and resolves their concentrations at different altitudes. This instrument has been designed to operate in tandem with the passive aerosol sensor currently used in AERONET (an established network of more than 450 ground aerosol monitoring instruments worldwide). Because aerosols induce a radiative effect that influences terrestrial carbon exchange, simultaneous detection of aerosols with these key carbon cycle gases offers a uniquely comprehensive measurement approach. Laser heterodyne radiometry is a technique for detecting weak signals that was adapted from radio receiver technology. In a radio receiver, a weak input signal from a radio antenna is mixed with a stronger local oscillator signal. The mixed signal (beat note, or intermediate frequency) has a frequency equal to the difference between the input signal and the local oscillator. The intermediate frequency is amplified and sent to a detector that extracts the audio from the signal. In the LHR instrument described here, sunlight that has undergone absorption by the trace gas is mixed with laser light at a frequency matched to a trace gas absorption feature in the infrared (IR). Mixing results in a beat signal in the RF (radio frequency) region that can be related to the atmospheric concentration. For a one-second integration, the estimated column sensitivities are 0.1 ppmv for CO2, and Greenhouse gases Observational SATellite). The only network that currently measures CO2 and CH4 in the atmospheric column is TCCON (Total Carbon Column Observing Network), and only two of its 16 operational sites are in the United States. TCCON data is used for validation of GOSAT data, and will be used for OCO-2 validation. While these Fourier-transform spectrometers (FTS) can measure the largest range of trace gases, the network is severely limited

  2. Improvement in deuterium recovery from water–isotope mixture by thermal diffusion in the device of branch columns

    International Nuclear Information System (INIS)

    Hsu, Ching-Chun; Yeh, Ho-Ming

    2014-01-01

    Highlights: • Recovery of deuterium by thermal diffusion from water–isotope mixture has been investigated. • The undesirable remixing effect can be reduced by employing the device of branch columns. • Deuterium recoveries were compared with that in a single column of the same total column length. • Considerable recovery improvement is obtainable in the device of branch columns, instead of in a single-column device. - Abstract: Deuterium recovery from water–isotopes mixture using thermal diffusion can be improved by employing the branch column device, instead of single column devices, with the same total column length. The remixing effect due to convection currents in a thermal diffusion column for heavy water enrichment is thus reduced and separation improvement increases when the flow rate or the total column length increases. The improvement in separation can reach about 50% for the numerical example given

  3. Seeing left- or right-asymmetric tail wagging produces different emotional responses in dogs.

    Science.gov (United States)

    Siniscalchi, Marcello; Lusito, Rita; Vallortigara, Giorgio; Quaranta, Angelo

    2013-11-18

    Left-right asymmetries in behavior associated with asymmetries in the brain are widespread in the animal kingdom, and the hypothesis has been put forward that they may be linked to animals' social behavior. Dogs show asymmetric tail-wagging responses to different emotive stimuli-the outcome of different activation of left and right brain structures controlling tail movements to the right and left side of the body. A crucial question, however, is whether or not dogs detect this asymmetry. Here we report that dogs looking at moving video images of conspecifics exhibiting prevalent left- or right-asymmetric tail wagging showed higher cardiac activity and higher scores of anxious behavior when observing left- rather than right-biased tail wagging. The finding that dogs are sensitive to the asymmetric tail expressions of other dogs supports the hypothesis of a link between brain asymmetry and social behavior and may prove useful to canine animal welfare theory and practice. Copyright © 2013 Elsevier Ltd. All rights reserved.

  4. Performance of zeolite scavenge column in Xe monitoring system

    International Nuclear Information System (INIS)

    Wang Qian; Wang Hongxia; Li Wei; Bian Zhishang

    2010-01-01

    In order to improve the performance of zeolite scavenge column, its ability of removal of humidity and carbon dioxide was studied by both static and dynamic approaches. The experimental results show that various factors, including the column length and diameter, the mass of zeolite, the content of water in air, the temperature rise during adsorption, and the activation effectiveness all effect the performance of zeolite column in scavenging humanity and carbon dioxide. Based on these results and previous experience, an optimized design of the zeolite column is made for use in xenon monitoring system. (authors)

  5. Experimental Verification of the Structural Glass Beam-Columns Strength

    Science.gov (United States)

    Pešek, Ondřej; Melcher, Jindřich; Balázs, Ivan

    2017-10-01

    This paper deals with experimental research of axially and laterally loaded members made of structural (laminated) glass. The purpose of the research is the evaluation of buckling strength and actual behaviour of the beam-columns due to absence of standards for design of glass load-bearing structures. The experimental research follows the previous one focusing on measuring of initial geometrical imperfections of glass members, testing of glass beams and columns. Within the frame of the research 9 specimens were tested. All of them were of the same geometry (length 2000 mm, width 200 mm and thickness 16 mm) but different composition - laminated double glass made of annealed glass or fully tempered glass panes bonded together by PVB or EVASAFE foil. Specimens were at first loaded by axial force and then by constantly increasing bending moment up to failure. During testing lateral deflections, vertical deflection and normal stresses at mid-span were measured. A maximum load achieved during testing has been adopted as flexural-lateral-torsional buckling strength. The results of experiments were statistically evaluated according to the European standard for design of structures EN 1990, appendix D. There are significant differences between specimens made of annealed glass or fully tempered glass. Differences between specimens loaded by axial forces 1 kN and 2 kN are negligible. The next step was to determine the design strength by calculation procedure based on buckling curves approach intended for design of steel columns and develop interaction criterion for glass beams-columns.

  6. Regional variation in the mechanical properties of the vertebral column during lateral bending in Morone saxatilis.

    Science.gov (United States)

    Nowroozi, B N; Brainerd, E L

    2012-10-07

    Unlike mammalian, disc-shaped intervertebral joints (IVJs), the IVJs in fishes are biconid structures, filled with fluid and thought to act as hydrostatic hinge joints during swimming. However, it remains unclear which IVJ structures are dominant in mechanical resistance to forces in fishes, and whether variation in these tissues might impact the function of the vertebral column along its length. Here, we measured the dynamic mechanical behaviour of IVJs from striped bass, Morone saxatilis. During lateral bending, angular stiffness was significantly lower in the caudal and cervical regions, relative to the abdominal region. The neutral zone, defined as the range of motion (ROM) at bending moments less than 0.001 Nm, was longer in the caudal relative to the abdominal IVJs. Hysteresis was 30-40% in all regions, suggesting that IVJs may play a role in energy dissipation during swimming. Cutting the vertical septum had no statistically significant effect, but cutting the encapsulating tissues caused a sharp decline in angular stiffness and a substantial increase in ROM and hysteresis. We conclude that stiffness decreases and ROM increases from cranial to caudal in striped bass, and that the encapsulating tissues play a prominent role in mechanical variation along the length of the vertebral column.

  7. Strength degradation of oxidized graphite support column in VHTR

    International Nuclear Information System (INIS)

    Park, Byung Ha; No, Hee Cheon

    2010-01-01

    Air-ingress events caused by large pipe breaks are important accidents considered in the design of Very High Temperature Gas-Cooled Reactors (VHTRs). A main safety concern for this type of event is the possibility of core collapse following the failure of the graphite support column, which can be oxidized by ingressed air. In this study, the main target is to predict the strength of the oxidized graphite support column. Through compression tests for fresh and oxidized graphite columns, the compressive strength of IG-110 was obtained. The buckling strength of the IG-110 column is expressed using the following empirical straight-line formula: σ cr,buckling =91.34-1.01(L/r). Graphite oxidation in Zone 1 is volume reaction and that in Zone 3 is surface reaction. We notice that the ultimate strength of the graphite column oxidized in Zones 1 and 3 only depends on the slenderness ratio and bulk density. Its strength degradation oxidized in Zone 1 is expressed in the following nondimensional form: σ/σ 0 =exp(-kd), k=0.114. We found that the strength degradation of a graphite column, oxidized in Zone 3, follows the above buckling empirical formula as the slenderness of the column changes. (author)

  8. Behaviour of normal reinforced concrete columns exposed to different soils

    Directory of Open Access Journals (Sweden)

    Rasheed Laith

    2018-01-01

    Full Text Available Concrete resistance to sulfate attack is one of the most important characteristics for maintaining the durability of concrete. In this study, the effect of the attack of sulfate salts on normal reinforced concrete column was investigated by burying these columns in two types of soils (sandy and clayey in two pits at a depth of 3 m in one of the agricultural areas in the holy city of Karbala, one containing sandy soil (SO3 = 10.609% and the other containing clayey soil with (SO3 = 2.61%. The tests were used (pure axial compression test of reinforced concrete columns, compressive strength test, and splitting tensile strength test, absorption, voids ratio and finally density. It`s found that the strength of RC columns decreasing by (12.51% for age (240 days, for columns buried in clayey soil, where the strength increased by (11.71% for the same period, for columns buried in sandy soils, with respect to the reference column.

  9. Column studies on BTEX biodegradation under microaerophilic and denitrifying conditions

    International Nuclear Information System (INIS)

    Hutchins, S.R.; Moolenaar, S.W.; Rhodes, D.E.

    1992-01-01

    Two column tests were conducted using aquifer material to simulate the nitrate field demonstration project carried out earlier at Traverse City, Michigan. The objectives were to better define the effect nitrate addition had on biodegradation of benzene, toluene, ethylbenzene, xylenes, and trimethylbenzenes (BTEX) in the field study, and to determine whether BTEX removal can be enhanced by supplying a limited amount of oxygen as a supplemental electron acceptor. Columns were operated using limited oxygen, limited oxygen plus nitrate, and nitrate alone. In the first column study, benzene was generally recalcitrant compared to the alkylbenzenes (TEX), although some removal did occur. In the second column study, nitrate was deleted from the feed to the column originally receiving nitrate alone and added to the feed of the column originally receiving limited oxygen alone. Although the requirement for nitrate for optimum TEX removal was clearly demonstrated in these columns, there were significant contributions by biotic and abiotic processes other than denitrification which could not be quantified

  10. column frame for design of reinforced concrete sway frames

    African Journals Online (AJOL)

    adminstrator

    design of slender reinforced concrete columns in sway frames according .... concrete,. Ac = gross cross-sectional area of the columns. Step 3: Effective Buckling Length Factors. The effective buckling length factors of columns in a sway frame shall be computed by .... shall have adequate resistance to failure in a sway mode ...

  11. Microstructural asymmetry of the corticospinal tracts predicts right-left differences in circle drawing skill in right-handed adolescents

    OpenAIRE

    Angstmann, Steffen; Madsen, Kathrine Skak; Skimminge, Arnold; Jernigan, Terry L; Baaré, William F C; Siebner, Hartwig Roman

    2016-01-01

    © 2016, The Author(s). Most humans show a strong preference to use their right hand, but strong preference for the right hand does not necessarily imply a strong right–left asymmetry in manual proficiency (i.e., dexterity). Here we tested the hypothesis that intra-individual asymmetry of manual proficiency would be reflected in microstructural differences between the right and left corticospinal tract (CST) in a cohort of 52 right-handed typically-developing adolescents (11–16 years). Partici...

  12. Investigation of Gas Holdup in a Vibrating Bubble Column

    Science.gov (United States)

    Mohagheghian, Shahrouz; Elbing, Brian

    2015-11-01

    Synthetic fuels are part of the solution to the world's energy crisis and climate change. Liquefaction of coal during the Fischer-Tropsch process in a bubble column reactor (BCR) is a key step in production of synthetic fuel. It is known from the 1960's that vibration improves mass transfer in bubble column. The current study experimentally investigates the effect that vibration frequency and amplitude has on gas holdup and bubble size distribution within a bubble column. Air (disperse phase) was injected into water (continuous phase) through a needle shape injector near the bottom of the column, which was open to atmospheric pressure. The air volumetric flow rate was measured with a variable area flow meter. Vibrations were generated with a custom-made shaker table, which oscillated the entire column with independently specified amplitude and frequency (0-30 Hz). Geometric dependencies can be investigated with four cast acrylic columns with aspect ratios ranging from 4.36 to 24, and injector needle internal diameters between 0.32 and 1.59 mm. The gas holdup within the column was measured with a flow visualization system, and a PIV system was used to measure phase velocities. Preliminary results for the non-vibrating and vibrating cases will be presented.

  13. Slender CRC Columns

    DEFF Research Database (Denmark)

    Aarup, Bendt; Jensen, Lars Rom; Ellegaard, Peter

    2005-01-01

    CRC is a high-performance steel fibre reinforced concrete with a typical compressive strength of 150 MPa. Design methods for a number of structural elements have been developed since CRC was invented in 1986, but the current project set out to further investigate the range of columns for which...

  14. Rasch models with exchangeable rows and columns

    DEFF Research Database (Denmark)

    Lauritzen, Steffen Lilholt

    The article studies distributions of doubly infinite binary matrices with exchangeable rows and columns which satify the further property that the probability of any $m \\times n$ submatrix is a function of the row- and column sums of that matrix. We show that any such distribution is a (unique...

  15. Seismic Performance of High-Ductile Fiber-Reinforced Concrete Short Columns

    Directory of Open Access Journals (Sweden)

    Mingke Deng

    2018-01-01

    Full Text Available This study mainly aims to investigate the effectiveness of high-ductile fiber-reinforced concrete (HDC as a means to enhance the seismic performance of short columns. Six HDC short columns and one reinforced concrete (RC short column were designed and tested under lateral cyclic loading. The influence of the material type (concrete or HDC, axial load, stirrup ratio, and shear span ratio on crack patterns, hysteresis behavior, shear strength, deformation capacity, energy dissipation, and stiffness degradation was presented and discussed, respectively. The test results show that the RC short column failed in brittle shear with poor energy dissipation, while using HDC to replace concrete can effectively improve the seismic behavior of the short columns. Compared with the RC short column, the shear strength of HDC specimens was improved by 12.6–30.2%, and the drift ratio and the energy dissipation increases were 56.9–88.5% and 237.7–336.7%, respectively, at the ultimate displacement. Additionally, the prediction model of the shear strength for RC columns based on GB50010-2010 (Chinese code can be safely adopted to evaluate the shear strength of HDC short columns.

  16. [Surgical angioplasty of the left main coronary artery].

    Science.gov (United States)

    Vranes, Mile; Velinović, Milos; Kocica, Mladen; Mikić, Aleksandar; Velimirović, Dusan; Djukić, Petar

    2010-01-01

    The conventional treatment for isolated stenosis of the left main coronary artery is bypass surgery (myocardial revascularization). However, the process of atherosclerosis is not arrested by myocardial revascularization and it will lead to the occlusion of the left main coronary artery. Revascularization will establish retrograde perfusion for 50-70% of the myocardium of the left ventricle. Direct surgical angioplasty of the left main coronary artery enables normal physiological perfusion of the whole myocardium and better myocardial function. The aim of our study is to point out a new surgical approach of treating left main coronary artery stenosis. Between October 2002 and October 2003, direct surgical angioplasty of the main left coronary artery was performed on three patients with isolated stenosis of the left main coronary artery using the anterior approach and the pericardium as a patch. The procedure was performed under total endotracheal anaesthesia and standard cardiopulmonary circulation, moderate hypothermia, anterograde St. Tomas cardioplegia and local cooling. Patients were followed clinically, echocardiographically and by load-tests. All three patients were without complications. In postoperative follow-up (54-68 months) neither angina pectoris nor electrocardiographically registered ischaemic changes were found. Load-tests performed every six months on all three patients were negative. Surgical angioplasty of isolated stenosis of the left main coronary artery is a preferred method for treating this type of coronary disease. Contraindications for this type of treatment are stenosis of the left main coronary artery with bifurcation and advanced calcification of the left main coronary artery.

  17. Materials performance in prototype Thermal Cycling Absorption Process (TCAP) columns

    International Nuclear Information System (INIS)

    Clark, E.A.

    1992-01-01

    Two prototype Thermal Cycling Absorption Process (TCAP) columns have been metallurgically examined after retirement, to determine the causes of failure and to evaluate the performance of the column container materials in this application. Leaking of the fluid heating and cooling subsystems caused retirement of both TCAP columns, not leaking of the main hydrogen-containing column. The aluminum block design TCAP column (AHL block TCAP) used in the Advanced Hydride Laboratory, Building 773-A, failed in one nitrogen inlet tube that was crimped during fabrication, which lead to fatigue crack growth in the tube and subsequent leaking of nitrogen from this tube. The Third Generation stainless steel design TCAP column (Third generation TCAP), operated in 773-A room C-061, failed in a braze joint between the freon heating and cooling tubes (made of copper) and the main stainless steel column. In both cases, stresses from thermal cycling and local constraint likely caused the nucleation and growth of fatigue cracks. No materials compatibility problems between palladium coated kieselguhr (the material contained in the TCAP column) and either aluminum or stainless steel column materials were observed. The aluminum-stainless steel transition junction appeared to be unaffected by service in the AHL block TCAP. Also, no evidence of cracking was observed in the AHL block TCAP in a location expected to experience the highest thermal shock fatigue in this design. It is important to limit thermal stresses caused by constraint in hydride systems designed to work by temperature variation, such as hydride storage beds and TCAP columns

  18. NMR imaging of the vertebral column and the spinal canal. 2. rev. and enl. ed.

    International Nuclear Information System (INIS)

    Forsting, Michael; Uhlenbrock, Detlev; Wanke, Isabel; Universitaetsklinikum Essen

    2009-01-01

    The book on the MRT (magnetic resonance tomography) of the vertebral cord and spinal canal covers the following topics: physics fundamentals and application; malformation of the spinal canal; degenerative vertebral column diseases; vertebral column and spinal canal carcinomas; inflammatory diseases of the vertebral column and the spinal canal; applicability of MRT in case of acute spinal cord traumata; vascular diseases of the spinal canal

  19. A study of pulse columns for thorium fuel reprocessing

    International Nuclear Information System (INIS)

    Fumoto, H.

    1982-03-01

    Two 5 m pulse columns with the same cartridge geometries are installed to investigate the performance. The characteristic differences of the aqueous continous and the organic continuous columns were investigated experimentally. A ternary system of 30% TBP in dodecane-acetic acid-water was adopted for the mass-transfer study. It was concluded that the overall mass-transfer coefficient was independent of whether the mass-transfer is from the dispersed to the continuous phase or from the continuous to the dispersed phase. Thorium nitrate was extracted and reextracted using both modes of operation. Both HETS and HTU were obtained. The aqueous continuous column gave much shorter HTU than the organic continuous column. In reextraction the organic continuous column gave shorter HTU. The Thorex-processes for uranium and thorium co-extraction, co-stripping, and partitioning were studied. Both acid feed solution and acid deficiend feed solution were investigated. The concentration profiles along the column height were obtained. The data were analysed with McCABE-THIELE diagrams to evaluate HETS. (orig./HP) [de

  20. Determination of lansoprazole enantiomers in dog plasma by column-switching liquid chromatography with tandem mass spectrometry and its application to a preclinical pharmacokinetic study.

    Science.gov (United States)

    Wang, Hao; Sun, Yantong; Meng, Xiangjun; Yang, Bo; Wang, Jian; Yang, Yan; Gu, Jingkai

    2015-09-01

    Lansoprazole, a selective proton pump inhibitor, has a chiral benzimidazole sulfoxide structure and is used for the treatment of gastric acid hypersecretory related diseases. To investigate its stereoselective pharmacokinetics, a column-switching liquid chromatography with tandem mass spectrometry method was developed for the determination of lansoprazole enantiomers in dog plasma using (+)-pantoprazole as an internal standard. After a simple protein precipitation procedure with acetonitrile, matrix components left behind after sample preparation were further eliminated from the sample by reversed-phase chromatography on a C18 column. The fluent was fed to a chiral column for the separation of lansoprazole enantiomers. Baseline separation of lansoprazole enantiomers was achieved on a Chiralcel OZ-RH column using acetonitrile/0.1% formic acid in water (35:65, v/v) as the mobile phase at 40°C. The linearity of the calibration curves ranged from 3 to 800 ng/mL for each enantiomer. Intra- and inter-day precisions ranged from 2.1 to 7.3% with an accuracy of ±1.7% for (+)-lansoprazole, and from 1.6 to 6.9% with an accuracy of ±3.5% for (-)-lansoprazole, respectively. The validated method was successfully applied for the stereoselective pharmacokinetic study of lansoprazole in beagle dog after intravenous infusion. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  1. Left-handedness and health

    Directory of Open Access Journals (Sweden)

    Milenković Sanja

    2010-01-01

    Full Text Available Hand dominance is defined as a proneness to use one hand rather than another in performing the majority of activities and this is the most obvious example of cerebral lateralization and an exclusive human characteristic. Left-handed people comprise 6-14% of the total population, while in Serbia, this percentage is 5-10%, moving from undeveloped to developed environments, where a socio-cultural pressure is less present. There is no agreement between investigators who in fact may be considered a left-handed person, about the percentage of left-handers in the population and about the etiology of left-handedness. In the scientific literature left-handedness has been related to health disorders (spine deformities, immunological disorders, migraine, neurosis, depressive psychosis, schizophrenia, insomnia, homosexuality, diabetes mellitus, arterial hypertension, sleep apnea, enuresis nocturna and Down Syndrome, developmental disorders (autism, dislexia and sttutering and traumatism. The most reliable scientific evidences have been published about the relationship between left-handedness and spinal deformities in school children in puberty and with traumatism in general population. The controversy of other results in up-to-now investigations of health aspects of left-handedness may partly be explained by a scientific disagreement whether writing with the left hand is a sufficient criterium for left-handedness, or is it necessary to investigate other parameters for laterality assessment. Explanation of health aspects of left-handedness is dominantly based on Geschwind-Galaburda model about 'anomalous' cerebral domination, as a consequence of hormonal disbalance. .

  2. [Left-handedness and health].

    Science.gov (United States)

    Milenković, Sanja; Belojević, Goran; Kocijancić, Radojka

    2010-01-01

    Hand dominance is defined as a proneness to use one hand rather than another in performing the majority of activities and this is the most obvious example of cerebral lateralization and an exclusive human characteristic. Left-handed people comprise 6-14% of the total population, while in Serbia, this percentage is 5-10%, moving from undeveloped to developed environments, where a socio-cultural pressure is less present. There is no agreement between investigators who in fact may be considered a left-handed person, about the percentage of left-handers in the population and about the etiology of left-handedness. In the scientific literature left-handedness has been related to health disorders (spine deformities, immunological disorders, migraine, neurosis, depressive psychosis, schizophrenia, insomnia, homosexuality, diabetes mellitus, arterial hypertension, sleep apnea, enuresis nocturna and Down Syndrome), developmental disorders (autism, dislexia and sttutering) and traumatism. The most reliable scientific evidences have been published about the relationship between left-handedness and spinal deformities in school children in puberty and with traumatism in general population. The controversy of other results in up-to-now investigations of health aspects of left-handedness may partly be explained by a scientific disagreement whether writing with the left hand is a sufficient criterium for left-handedness, or is it necessary to investigate other parameters for laterality assessment. Explanation of health aspects of left-handedness is dominantly based on Geschwind-Galaburda model about "anomalous" cerebral domination, as a consequence of hormonal disbalance.

  3. The three-dimensional model for helical columns on type-J synchronous counter-current chromatography.

    Science.gov (United States)

    Guan, Y H; van den Heuvel, Remco

    2011-08-05

    Unlike the existing 2-D pseudo-ring model for helical columns undergoing synchronous type-J planetary motion of counter-current chromatograph (CCC), the 3-D "helix" model developed in this work shows that there is a second normal force (i.e. the binormal force) applied virtually in the axial direction of the helical column. This force alternates in the two opposite directions and intensifies phase mixing with increasing the helix angle. On the contrary, the 2-D spiral column operated on the same CCC device lacks this third-dimensional mixing force. The (principal) normal force quantified by this "helix" model has been the same as that by the pseudo-ring model. With β>0.25, this normal centrifugal force has been one-directional and fluctuates cyclically. Different to the spiral column, this "helix" model shows that the centrifugal force (i.e. the hydrostatic force) does not contribute to stationary phase retention in the helical column. Between the popular helical columns and the emerging spiral columns for type-J synchronous CCC, this work has thus illustrated that the former is associated with better phase mixing yet poor retention for the stationary phase whereas the latter has potential for better retention for the stationary phase yet poor phase mixing. The methodology developed in this work may be regarded as a new platform for designing optimised CCC columns for analytical and engineering applications. Copyright © 2011 Elsevier B.V. All rights reserved.

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

    Science.gov (United States)

    Gritti, Fabrice; Guiochon, Georges

    2012-03-09

    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 μm 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 μm (2006), and of sub-3 μm 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 μm 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 μL² 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 μm silica core-shell particles provide peaks that have a variance of 2.1 μL² 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 μm 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

  5. Modeling and analysis of conventional and heat-integrated distillation columns

    DEFF Research Database (Denmark)

    Bisgaard, Thomas; Huusom, Jakob Kjøbsted; Abildskov, Jens

    2015-01-01

    A generic model that can cover diabatic and adiabatic distillation column configurations is presented, with the aim ofproviding a consistent basis for comparison of alternative distillation column technologies. Both a static and a dynamic formulation of the model, together with a model catalogue...... consisting of the conventional, the heat-integrated and the mechanical vapor recompression distillation columns are presented. The solution procedure of the model is outlined and illustrated in three case studies. One case study being a benchmark study demonstrating the size of the model and the static...... properties of two different heat-integrated distillation column (HIDiC) schemes and the mechanical vapor recompression column. The second case study exemplifies the difference between a HIDiC and a conventional distillation column in the composition profiles within a multicomponent separation, whereas...

  6. Comprehensive two-dimensional HPLC to study the interaction of multiple components in Rheum palmatum L. with HSA by coupling a silica-bonded HSA column to a silica monolithic ODS column.

    Science.gov (United States)

    Hu, Lianghai; Li, Xin; Feng, Shun; Kong, Liang; Su, Xingye; Chen, Xueguo; Qin, Feng; Ye, Mingliang; Zou, Hanfa

    2006-04-01

    A mode of comprehensive 2-D LC was developed by coupling a silica-bonded HSA column to a silica monolithic ODS column. This system combined the affinity property of the HSA column and the high-speed separation ability of the monolithic ODS column. The affinity chromatography with HSA-immobilized stationary phase was applied to study the interaction of multiple components in traditional Chinese medicines (TCMs) with HSA according to their affinity to protein in the first dimension. Then the unresolved components retained on the HSA column were further separated on the silica monolithic ODS column in the second dimension. By hyphenating the 2-D separation system to diode array detector and MS detectors, the UV and molecular weight information of the separated compounds can also be obtained. The developed separation system was applied to analysis of the extract of Rheum palmatum L., a number of low-abundant components can be separated on a single peak from the HSA column after normalization of peak heights. Six compounds were preliminarily identified according to their UV and MS spectra. It showed that this system was very useful for biological fingerprinting analysis of the components in TCMs and natural products.

  7. Systolic left ventricular function according to left ventricular concentricity and dilatation in hypertensive patients

    DEFF Research Database (Denmark)

    Bang, Casper; Gerdts, Eva; Aurigemma, Gerard P

    2013-01-01

    Left ventricular hypertrophy [LVH, high left ventricular mass (LVM)] is traditionally classified as concentric or eccentric based on left ventricular relative wall thickness. We evaluated left ventricular systolic function in a new four-group LVH classification based on left ventricular dilatation...... [high left ventricular end-diastolic volume (EDV) index and concentricity (LVM/EDV)] in hypertensive patients....

  8. Synthesis and characterization of Mn-doped ZnO column arrays

    International Nuclear Information System (INIS)

    Yang Mei; Guo Zhixing; Qiu Kehui; Long Jianping; Yin Guangfu; Guan Denggao; Liu Sutian; Zhou Shijie

    2010-01-01

    Mn-doped ZnO column arrays were successfully synthesized by conventional sol-gel process. Effect of Mn/Zn atomic ratio and reaction time were investigated, and the morphology, tropism and optical properties of Mn-doped ZnO column arrays were characterized by SEM, XRD and photoluminescence (PL) spectroscopy. The result shows that a Mn/Zn atomic ratio of 0.1 and growth time of 12 h are the optimal condition for the preparation of densely distributed ZnO column arrays. XRD analysis shows that Mn-doped ZnO column arrays are highly c-axis oriented. As for Mn-doped ZnO column arrays, obvious increase of photoluminescence intensity is observed at the wavelength of ∼395 nm and ∼413 nm, compared to pure ZnO column arrays.

  9. Influence of Connection Placement to the Behavior of Precast Concrete Exterior Beam-Column Joint

    Directory of Open Access Journals (Sweden)

    Elly Tjahjono

    2010-10-01

    Full Text Available This paper presents an experimental study on the influence of connection placement to the behaviour of exterior beamcolumn joint of precast concrete structure under semi cyclic loading. Four half-scale beam-column specimens were investigated. Three beam-columns were jointed through connection that are placed in beam-column joint region and the forth is connected at the plastic hinge potensial region of the beam. Crack patterns, strength, stiffness and ductility of the test specimens have been evaluated. The test result indicated that all beam-column specimens show good ductility behavior.

  10. Temperature optimization for the separation of PAHs on micropacked LC ODS columns

    NARCIS (Netherlands)

    Chen, J.; Steenackers, D.; Sandra, P.J.F.; Sandra, P.J.F.; Devos, G.

    1993-01-01

    The effect of column temperature on the separation of the sixteen polycyclic aromatic hydrocarbons (PAHs) of mixture SRM 1647a of the US Environmental Protection Agency has been studied on different micropacked ODS columns. lsothermal temperature optimization was successfully applied for complete

  11. Temperature optimization for the separation of PAHs on micropacked LC ODS columns

    NARCIS (Netherlands)

    Chen, J.; Steenackers, D.; Medvedovici, A.; Sandra, P.J.F.

    1993-01-01

    The effect of column temperature on the separation of the sixteen polycyclic aromatic hydrocarbons (PAHs) of mixture SRM 1647a of the US Environmental Protection Agency has been studied on different micropacked ODS columns. Isothermal temperature optimization was successfully used for complete

  12. Bronchial compression by an enlarged left atrium in infants; a cause of hypovascularity of the left lung

    Energy Technology Data Exchange (ETDEWEB)

    Corr, L.; Hallidie-Smith, K.A.; McCarthy, P.A.; Lavender, J.P.

    1988-09-01

    In three infants seen recently at our institution we noted signs of compression of the left main bronchus associated with enlarged left atria. None of our cases demonstrated the more usual signs of hyperinflation which are a hyperlucent lung field, depressed hemidiaphragm and mediastinal shift away from the affected side. In addition, hypoperfusion of the left lung was noted in each case. We believe that bronchial compression due to an enlarged left atrium, with consequent hypoxic vasoconstriction is a clinically significant entity, which is not well described and may be unappreciated in infants in whom the typical signs of hyperinflation are absent.

  13. Microstructural asymmetry of the corticospinal tracts predicts right-left differences in circle drawing skill in right-handed adolescents.

    Science.gov (United States)

    Angstmann, Steffen; Madsen, Kathrine Skak; Skimminge, Arnold; Jernigan, Terry L; Baaré, William F C; Siebner, Hartwig Roman

    2016-12-01

    Most humans show a strong preference to use their right hand, but strong preference for the right hand does not necessarily imply a strong right-left asymmetry in manual proficiency (i.e., dexterity). Here we tested the hypothesis that intra-individual asymmetry of manual proficiency would be reflected in microstructural differences between the right and left corticospinal tract (CST) in a cohort of 52 right-handed typically-developing adolescents (11-16 years). Participants were asked to fluently draw superimposed circles with their right dominant and left non-dominant hand. Temporal regularity of circle drawing movements was assessed for each hand using a digitizing tablet. Although all participants were right-handed, there was substantial inter-individual variation regarding the relative right-hand advantage for fluent circle drawing. All subjects underwent whole-brain diffusion tensor imaging at 3 Tesla. The right and left CST were defined as regions-of-interest and mean fractional anisotropy (FA) and diffusivity values were calculated for right and left CST. On average, mean FA values were higher in the left CST relative to right CST. The degree of right-left FA asymmetry showed a linear relationship with right-left asymmetry in fluent circle drawing after correction for age and gender. The higher the mean FA values were in the left dominant CST relative to the right non-dominant CST, the stronger was the relative right-hand advantage for regular circle drawing. These findings show that right-left differences in manual proficiency are highly variable in right-handed adolescents and that this variation is associated with a right-left microstructural asymmetry of the CST.

  14. Study on the dynamic holdup distribution of the pulsed extraction column

    International Nuclear Information System (INIS)

    Wang, S.; Chen, J.; Wu, Q.

    2013-01-01

    In the study, a CSTR cascade dynamic hydraulic model was developed to investigate the dynamic holdup distribution of the pulsed extraction column. It is assumed that the dynamic process of the dispersed phase holdup of pulsed extraction column has equal effects with the operational process of multiple cascade CSTRs. The process is consistent with the following assumptions: the holdups vary on different stages but maintain uniform on each stage; the changes of the hydraulic parameters have impact initially on the inlet of dispersed phase, and stability will be reached gradually through stage-by-stage blending. The model was tested and verified utilizing time domain response curves of the average holdup. Nearly 150 experiments were carried out with different capillary columns, various feed liquids, and diverse continuous phases and under different operation conditions. The regression curves developed by the model show a good consistency with the experimental results. After linking parameters of the model with operational conditions, the study further found that the parameters are only linearly correlated with pulse conditions and have nothing to do with flow rate for a specific pulsed extraction column. The accuracy of the model is measured by the average holdup, and the absolute error is ±0.01. The model can provide supports for the boundary studies on hydraulics and mass transfer by making simple and reliable prediction of the dynamic holdup distribution, with relatively less accessible hydraulic experimental data. (authors)

  15. Study on the dynamic holdup distribution of the pulsed extraction column

    Energy Technology Data Exchange (ETDEWEB)

    Wang, S.; Chen, J.; Wu, Q. [Tsinghua University, Beijing 100084 (China)

    2013-07-01

    In the study, a CSTR cascade dynamic hydraulic model was developed to investigate the dynamic holdup distribution of the pulsed extraction column. It is assumed that the dynamic process of the dispersed phase holdup of pulsed extraction column has equal effects with the operational process of multiple cascade CSTRs. The process is consistent with the following assumptions: the holdups vary on different stages but maintain uniform on each stage; the changes of the hydraulic parameters have impact initially on the inlet of dispersed phase, and stability will be reached gradually through stage-by-stage blending. The model was tested and verified utilizing time domain response curves of the average holdup. Nearly 150 experiments were carried out with different capillary columns, various feed liquids, and diverse continuous phases and under different operation conditions. The regression curves developed by the model show a good consistency with the experimental results. After linking parameters of the model with operational conditions, the study further found that the parameters are only linearly correlated with pulse conditions and have nothing to do with flow rate for a specific pulsed extraction column. The accuracy of the model is measured by the average holdup, and the absolute error is ±0.01. The model can provide supports for the boundary studies on hydraulics and mass transfer by making simple and reliable prediction of the dynamic holdup distribution, with relatively less accessible hydraulic experimental data. (authors)

  16. How Auditory Experience Differentially Influences the Function of Left and Right Superior Temporal Cortices.

    Science.gov (United States)

    Twomey, Tae; Waters, Dafydd; Price, Cathy J; Evans, Samuel; MacSweeney, Mairéad

    2017-09-27

    To investigate how hearing status, sign language experience, and task demands influence functional responses in the human superior temporal cortices (STC) we collected fMRI data from deaf and hearing participants (male and female), who either acquired sign language early or late in life. Our stimuli in all tasks were pictures of objects. We varied the linguistic and visuospatial processing demands in three different tasks that involved decisions about (1) the sublexical (phonological) structure of the British Sign Language (BSL) signs for the objects, (2) the semantic category of the objects, and (3) the physical features of the objects.Neuroimaging data revealed that in participants who were deaf from birth, STC showed increased activation during visual processing tasks. Importantly, this differed across hemispheres. Right STC was consistently activated regardless of the task whereas left STC was sensitive to task demands. Significant activation was detected in the left STC only for the BSL phonological task. This task, we argue, placed greater demands on visuospatial processing than the other two tasks. In hearing signers, enhanced activation was absent in both left and right STC during all three tasks. Lateralization analyses demonstrated that the effect of deafness was more task-dependent in the left than the right STC whereas it was more task-independent in the right than the left STC. These findings indicate how the absence of auditory input from birth leads to dissociable and altered functions of left and right STC in deaf participants. SIGNIFICANCE STATEMENT Those born deaf can offer unique insights into neuroplasticity, in particular in regions of superior temporal cortex (STC) that primarily respond to auditory input in hearing people. Here we demonstrate that in those deaf from birth the left and the right STC have altered and dissociable functions. The right STC was activated regardless of demands on visual processing. In contrast, the left STC was

  17. Columns in Clay

    Science.gov (United States)

    Leenhouts, Robin

    2010-01-01

    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…

  18. 46 CFR 174.085 - Flooding on column stabilized units.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 7 2010-10-01 2010-10-01 false Flooding on column stabilized units. 174.085 Section 174... Units § 174.085 Flooding on column stabilized units. (a) Watertight compartments that are outboard of... of the unit, must be assumed to be subject to flooding as follows: (1) When a column is subdivided...

  19. On-column reduction of catecholamine quinones in stainless steel columns during liquid chromatography.

    Science.gov (United States)

    Xu, R; Huang, X; Kramer, K J; Hawley, M D

    1995-10-10

    The chromatographic behavior of quinones derived from the oxidation of dopamine and N-acetyldopamine has been studied using liquid chromatography (LC) with both a diode array detector and an electrochemical detector that has parallel dual working electrodes. When stainless steel columns are used, an anodic peak for the oxidation of the catecholamine is observed at the same retention time as a cathodic peak for the reduction of the catecholamine quinone. In addition, the anodic peak exhibits a tail that extends to a second anodic peak for the catecholamine. The latter peak occurs at the normal retention time of the catecholamine. The origin of this phenomenon has been studied and metallic iron in the stainless steel components of the LC system has been found to reduce the quinones to their corresponding catecholamines. The simultaneous appearance of a cathodic peak for the reduction of catecholamine quinone and an anodic peak for the oxidation of the corresponding catecholamine occurs when metallic iron in the exit frit reduces some of the quinones as the latter exits the column. This phenomenon is designated as the "concurrent anodic-cathodic response." It is also observed for quinones of of 3,4-dihydroxybenzoic acid and probably occurs with o- or p-quinones of other dihydroxyphenyl compounds. The use of nonferrous components in LC systems is recommended to eliminate possible on-column reduction of quinones.

  20. The Prognostic Value of Left Atrial Peak Reservoir Strain in Acute Myocardial Infarction Is Dependent on Left Ventricular Longitudinal Function and Left Atrial Size

    DEFF Research Database (Denmark)

    Ersbøll, Mads; Andersen, Mads J; Valeur, Nana

    2013-01-01

    of PALS and left ventricular longitudinal strain (global longitudinal strain) in large-scale populations in regard to prognosis. METHODS AND RESULTS: We prospectively included 843 patients (mean age 62.1+/-11.8; 74% male) with acute myocardial infarction and measured global longitudinal strain, left......BACKGROUND: Peak atrial longitudinal strain (PALS) during the reservoir phase has been proposed as a measure of left atrium function in a range of cardiac conditions, with the potential for added pathophysiological insight and prognostic value. However, no studies have assessed the interrelation...

  1. Characterization of a chromatographic column for the production of 90Sr

    International Nuclear Information System (INIS)

    Fornaciari Iljadica, Maria C.; Furnari, Juan C.; Cohen, Isaac M.

    2003-01-01

    The experiments carried out with the objective of developing a method for 90 Sr production, associated to that of 99 Mo from 235 U fission, which is routinely performed at Centro Atomico Ezeiza, Comision Nacional de Energia Atomica, are described. The project consists of strontium separation from a nitric solution containing uranium and a variety of fission products, by retention and subsequent elution in selective chromatographic columns. Both these columns and the conditions for their use in a routine production process have been characterized. The experiments show good Sr-Ba separation, high concentration of activity for the obtained 90 Sr, and minimal losses; in addition, the non-existence of significant radiation damage, as a limiting factor of the separative capacity of the columns, has been verified. (author)

  2. A column-store meets the point clouds

    NARCIS (Netherlands)

    Martinez-Rubi, O.; Kersten, M.L.; Goncalves, R.; Ivanova, M.

    2014-01-01

    Column stores have become the de-facto standard for most datawarehouse solutions. The regularity and query patterns of LIDAR data are a potential application area well suited for this technology. In this short work in progress paper we report on our experiences in supporting point cloud data using

  3. Effects of Irregular Bridge Columns and Feasibility of Seismic Regularity

    Science.gov (United States)

    Thomas, Abey E.

    2018-05-01

    Bridges with unequal column height is one of the main irregularities in bridge design particularly while negotiating steep valleys, making the bridges vulnerable to seismic action. The desirable behaviour of bridge columns towards seismic loading is that, they should perform in a regular fashion, i.e. the capacity of each column should be utilized evenly. But, this type of behaviour is often missing when the column heights are unequal along the length of the bridge, allowing short columns to bear the maximum lateral load. In the present study, the effects of unequal column height on the global seismic performance of bridges are studied using pushover analysis. Codes such as CalTrans (Engineering service center, earthquake engineering branch, 2013) and EC-8 (EN 1998-2: design of structures for earthquake resistance. Part 2: bridges, European Committee for Standardization, Brussels, 2005) suggests seismic regularity criterion for achieving regular seismic performance level at all the bridge columns. The feasibility of adopting these seismic regularity criterions along with those mentioned in literatures will be assessed for bridges designed as per the Indian Standards in the present study.

  4. EFFECTS OF COLUMN FAILURES ON THE INTERNAL FORCES OF ORTHOGONAL REINFORCED CONCRETE BUILDING FRAMES

    Directory of Open Access Journals (Sweden)

    Nilay KAYA

    2006-02-01

    Full Text Available In this study, the effects of column failures which may take place due to the special causes such as blast, vehicle impact, insufficient or deficient design, on the internal forces of orthogonal reinforced concrete building frames have been investigated. Calculations have been performed with SAP2000 structural analysis program, under static conditions. For a typical frame system, firstly, various column failure scenarios have been considered for uninfilled case and internal forces have been calculated and compared with those in the intact case. Then, similar calculations have been implemented for the case of presence of infill walls. The results of analyses have shown that the effects of column failures had condensed on the neighbor columns and beams of orthogonal frames on which the columns had been failed. Moreover, it has been determined that, while the bending moment capacities of the connected beams to the failed columns had exceeded in the bare frames, in the masonry infilled frames, walls give substantial support to the structural elements of the building, and capacities of the beams had not exceeded.

  5. Wire-Mesh Tomography Measurements of Void Fraction in Rectangular Bubble Columns

    International Nuclear Information System (INIS)

    Reddy Vanga, B.N.; Lopez de Bertodano, M.A.; Zaruba, A.; Prasser, H.M.; Krepper, E.

    2004-01-01

    Bubble Columns are widely used in the process industry and their scale-up from laboratory scale units to industrial units have been a subject of extensive study. The void fraction distribution in the bubble column is affected by the column size, superficial velocity of the dispersed phase, height of the liquid column, size of the gas bubbles, flow regime, sparger design and geometry of the bubble column. The void fraction distribution in turn affects the interfacial momentum transfer in the bubble column. The void fraction distribution in a rectangular bubble column 10 cm wide and 2 cm deep has been measured using Wire-Mesh Tomography. Experiments were performed in an air-water system with the column operating in the dispersed bubbly flow regime. The experiments also serve the purpose of studying the performance of wire-mesh sensors in batch flows. A 'wall peak' has been observed in the measured void fraction profiles, for the higher gas flow rates. This 'wall peak' seems to be unique, as this distribution has not been previously reported in bubble column literature. Low gas flow rates yielded the conventional 'center peak' void profile. The effect of column height and superficial gas velocity on the void distribution has been investigated. Wire-mesh Tomography also facilitates the measurement of bubble size distribution in the column. This paper presents the measurement principle and the experimental results for a wide range of superficial gas velocities. (authors)

  6. The Left, The Better: White-Matter Brain Integrity Predicts Foreign Language Imitation Ability.

    Science.gov (United States)

    Vaquero, Lucía; Rodríguez-Fornells, Antoni; Reiterer, Susanne M

    2017-08-01

    Speech imitation is crucial for language acquisition and second-language learning. Interestingly, large individual differences regarding the ability in imitating foreign-language sounds have been observed. The origin of this interindividual diversity remains unknown, although it might be partially explained by structural predispositions. Here we correlated white-matter structural properties of the arcuate fasciculus (AF) with the performance of 52 German-speakers in a Hindi sentence- and word-imitation task. First, a manual reconstruction was performed, permitting us to extract the mean values along the three branches of the AF. We found that a larger lateralization of the AF volume toward the left hemisphere predicted the performance of our participants in the imitation task. Second, an automatic reconstruction was carried out, allowing us to localize the specific region within the AF that exhibited the largest correlation with foreign language imitation. Results of this reconstruction also showed a left lateralization trend: greater fractional anisotropy values in the anterior half of the left AF correlated with the performance in the Hindi-imitation task. From the best of our knowledge, this is the first time that foreign language imitation aptitude is tested using a more ecological imitation task and correlated with DTI tractography, using both a manual and an automatic method. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  7. Equipment for automatic measurement of gamma activity distribution in a column

    International Nuclear Information System (INIS)

    Kalincak, M.; Machan, V.; Vilcek, S.; Balkovsky, K.

    1978-01-01

    The design of a device for stepwise scanning of gamma activity distributions along chromatographic columns is described. In connection with a single-channel gamma spectrometer and a counting ratemeter with a recorder this device permits the resolution of a number of gamma emitters on the column, the determination of the gamma nuclide content in different chemical forms in the sample by means of column separation methods - Gel Chromatography Columns Scanning Method - and the determination of gamma nuclide distribution along the columns. The device permits the scanning of columns of up to 20 mm in diameter and 700 mm in length and continual scanning over a 450 mm column length with one clamping. With minor adaptations it is possible to scan columns up to 30 mm in diameter. The length of the scanned sections is 5 or 10 mm, the scanning time setting is arbitrary and variable activity levels and radiation energies may be measured. (author)

  8. Development of a New Radiation Measuring Instrument for the Column Scanning Technique - NibraS

    International Nuclear Information System (INIS)

    Benahmed, A.; Alami, R.

    2013-06-01

    The radiation measuring instrument, called Nibras, associated to a special data processing software for Column scanning is a new data acquisition system. It was developed to scan and to plot density profiles, inside a distillation column, which illustrates the activity of the radiations able to cross the contents of the column. Nibras is an autonomous data logger with very low power consumption, using only 4 batteries of 1.5 V and can be operated for more than 120 hours continuously; this presents an ecological and economic importance. Another particularity of Nibras consists in its dual functionality to display counting rates indicating the existence and the intensity of radiation; and to perform a real-time control in industrial plant particularly in oil distillation columns, due to its user-friendly software. This last provides essential data to optimize the performance of the columns, extend column run times, track the performance-deteriorating effects of fouling and solids deposition, and to identify maintenance requirements well in advance of scheduled turnarounds. This on-line knowledge can reduce repair downtime significantly. (authors)

  9. Prediction of axial limit capacity of stone columns using dimensional analysis

    Science.gov (United States)

    Nazaruddin A., T.; Mohamed, Zainab; Mohd Azizul, L.; Hafez M., A.

    2017-08-01

    Stone column is the most favorable method used by engineers in designing work for stabilization of soft ground for road embankment, and foundation for liquid structure. Easy installation and cheaper cost are among the factors that make stone column more preferable than other method. Furthermore, stone column also can acts as vertical drain to increase the rate of consolidation during preloading stage before construction work started. According to previous studied there are several parameters that influence the capacity of stone column. Among of them are angle friction of among the stones, arrangement of column (two pattern arrangement most applied triangular and square), spacing center to center between columns, shear strength of soil, and physical size of column (diameter and length). Dimensional analysis method (Buckingham-Pi Theorem) has used to carry out the new formula for prediction of load capacity stone columns. Experimental data from two previous studies was used for analysis of study.

  10. Visceral subpleural hematoma of the left diaphragmatic surface following left upper division segmentectomy

    Directory of Open Access Journals (Sweden)

    Yasushi Mizukami

    2017-10-01

    Full Text Available Abstract Background Pulmonary visceral subpleural hematoma is rare. We report visceral subpleural hematoma of the left diaphragmatic surface following left upper division segmentectomy. This very rare case was difficult to distinguish from thoracic abscess. Case presentation A 68-year-old man with hypertension had undergone video-assisted thoracoscopic left upper division segmentectomy for suspected lung carcinoma. Deep vein thrombosis of the lower leg was identified and edoxaban, a so-called novel oral anticoagulant, was started on postoperative day 7. The chest drainage tube was removed on postoperative day 12 because of persistent air leakage, but fever appeared the same day. Computed tomography revealed a cavity with mixed air and fluid, so antibiotics were started on suspicion of abscess. Computed tomography-guided drainage was attempted, but proved unsuccessful. Fever continued and surgical investigation was therefore performed. Visceral subpleural hematoma was identified under the diaphragmatic surface of the left basal lung. We excised the pleura, then performed drainage and applied running sutures. The parenchyma and visceral pleura were covered with polyglycolic acid sheet and fibrin glue. Edoxaban was restarted on postoperative day 12 of video-assisted thoracoscopic surgery and no recurrence of hematoma has been revealed. Conclusions Visceral subpleural hematoma after thoracic surgery is extremely rare. Furthermore, correct diagnosis was difficult and surgery offered a good diagnostic and therapeutic procedure.

  11. Capacity of columns with splice imperfections

    International Nuclear Information System (INIS)

    Popov, E.P.; Stephen, R.M.

    1977-01-01

    To study the behavior of spliced columns subjected to tensile forces simulating situations which may develop in an earthquake, all of the spliced specimens were tested to failure in tension after first having been subjected to large compressive loads. The results of these tests indicate that the lack of perfect contact at compression splices of columns may not be important, provided that the gaps are shimmed and welding is used to maintain the sections in alignment

  12. Three-dimensional motion pattern of the caudal lumbar and lumbosacral portions of the vertebral column of dogs.

    Science.gov (United States)

    Benninger, Monika I; Seiler, Gabriela S; Robinson, Leanne E; Ferguson, Stephen J; Bonél, Harald M; Busato, André R; Lang, Johann

    2004-05-01

    To evaluate the 3-dimensional motion pattern including main and coupled motions of the caudal lumbar and lumbosacral portions of the vertebral column of dogs. Vertebral columns of 9 German Shepherd Dogs (GSDs) and 16 dogs of other breeds with similar body weights and body conditions. Main and coupled motions of the caudal lumbar and lumbosacral portions of the vertebral column (L4 to S1) were determined by use of a testing apparatus that permitted precise application of known pure moments to the vertebral column. Motion was compared between GSDs and dogs of other breeds. All specimens had a similar motion pattern consisting of main motion and a certain amount of coupled motion including translation. Vertebral columns of GSDs had significantly less main motion in all directions than that of dogs of other breeds. Translation was similar in GSDs and dogs of other breeds and was smallest at the lumbosacral motion segment. Results indicated that motion in the caudal lumbar and lumbosacral portions of the vertebral column of dogs is complex and provided a basis for further studies evaluating abnormal vertebral columns.

  13. Application of partially diabatic divided wall column to floating liquefied natural gas plant

    International Nuclear Information System (INIS)

    Kim, Young Han

    2014-01-01

    The offshore operation of chemical plant requires the compactness of process equipments due to its harsh environment. A DWC (divided wall column), a compact ternary separator, is a good candidate for distillation process in the offshore operation. In this study the DWC is applied to the offshore FLNG (floating liquefied natural gas) plant, but high utility cost is required in the application because of the large difference of boiling points among feed components. A partially diabatic DWC is proposed for the reduction of the operating cost here, and its design procedure is presented along with performance and economic evaluations and the examination of thermodynamic efficiency as well. The heating duty of the proposed DWC including tray heat transfer is 35% less than that of the conventional system, and the cooling duty is 18% less. The evaluation indicates that some 16% less utility cost is used in the DWC compared with the conventional system, though 7% more investment is required. The exergy loss is reduced by 12%, and the thermodynamic efficiency is improved by 3.3 percentage point over the conventional system. - Highlights: • Diabatic divided wall column for FLNG (floating liquefied natural gas) plant. • Compact column for offshore operation. • 35% less heating duty required. • 16% lower utility necessary. • Exergy loss reduced by 12%

  14. Mini-columns for Conducting Breakthrough Experiments. Design and Construction

    Energy Technology Data Exchange (ETDEWEB)

    Dittrich, Timothy M. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Reimus, Paul William [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Ware, Stuart Douglas [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2015-06-11

    Experiments with moderately and strongly sorbing radionuclides (i.e., U, Cs, Am) have shown that sorption between experimental solutions and traditional column materials must be accounted for to accurately determine stationary phase or porous media sorption properties (i.e., sorption site density, sorption site reaction rate coefficients, and partition coefficients or Kd values). This report details the materials and construction of mini-columns for use in breakthrough columns to allow for accurate measurement and modeling of sorption parameters. Material selection, construction techniques, wet packing of columns, tubing connections, and lessons learned are addressed.

  15. SPEEDUPtrademark ion exchange column model

    International Nuclear Information System (INIS)

    Hang, T.

    2000-01-01

    A transient model to describe the process of loading a solute onto the granular fixed bed in an ion exchange (IX) column has been developed using the SpeedUptrademark software package. SpeedUp offers the advantage of smooth integration into other existing SpeedUp flowsheet models. The mathematical algorithm of a porous particle diffusion model was adopted to account for convection, axial dispersion, film mass transfer, and pore diffusion. The method of orthogonal collocation on finite elements was employed to solve the governing transport equations. The model allows the use of a non-linear Langmuir isotherm based on an effective binary ionic exchange process. The SpeedUp column model was tested by comparing to the analytical solutions of three transport problems from the ion exchange literature. In addition, a sample calculation of a train of three crystalline silicotitanate (CST) IX columns in series was made using both the SpeedUp model and Purdue University's VERSE-LC code. All test cases showed excellent agreement between the SpeedUp model results and the test data. The model can be readily used for SuperLigtrademark ion exchange resins, once the experimental data are complete

  16. Title of the paper goes here second line

    Indian Academy of Sciences (India)

    Title of the paper goes here second line. AUTHOR11, AUTHOR21 and AUTHOR32,*. 1 Department of P, University X. 2 Department of Q, University Z. Abstract. Abstract text goes here. Abstract text goes here. Abstract text goes here. Abstract text goes here. Abstract text goes here. Abstract text goes here. Abstract text goes ...

  17. Intense molybdenum accumulation in sediments underneath a nitrogenous water column and implications for the reconstruction of paleo-redox conditions based on molybdenum isotopes

    Science.gov (United States)

    Scholz, Florian; Siebert, Christopher; Dale, Andrew W.; Frank, Martin

    2017-09-01

    The concentration and isotope composition of molybdenum (Mo) in sediments and sedimentary rocks are widely used proxies for anoxic conditions in the water column of paleo-marine systems. While the mechanisms leading to Mo fixation in modern restricted basins with anoxic and sulfidic (euxinic) conditions are reasonably well constrained, few studies have focused on Mo cycling in the context of open-marine anoxia. Here we present Mo data for water column particulate matter, modern surface sediments and a paleo-record covering the last 140,000 years from the Peruvian continental margin. Mo concentrations in late Holocene and Eemian (penultimate interglacial) shelf sediments off Peru range from ∼70 to 100 μg g-1, an extent of Mo enrichment that is thought to be indicative of (and limited to) euxinic systems. To investigate if this putative anomaly could be related to the occasional occurrence of sulfidic conditions in the water column overlying the Peruvian shelf, we compared trace metal (Mo, vanadium, uranium) enrichments in particulate matter from oxic, nitrate-reducing (nitrogenous) and sulfidic water masses. Coincident enrichments of iron (Fe) (oxyhydr)oxides and Mo in the nitrogenous water column as well as co-variation of dissolved Fe and Mo in the sediment pore water suggest that Mo is delivered to the sediment surface by Fe (oxyhydr)oxides. Most of these precipitate in the anoxic-nitrogenous water column due to oxidation of sediment-derived dissolved Fe with nitrate as a terminal electron acceptor. Upon reductive dissolution in the surface sediment, a fraction of the Fe and Mo is re-precipitated through interaction with pore water sulfide. The Fe- and nitrate-dependent mechanism of Mo accumulation proposed here is supported by the sedimentary Mo isotope composition, which is consistent with Mo adsorption onto Fe (oxyhydr)oxides. Trace metal co-variation patterns as well as Mo and nitrogen isotope systematics suggest that the same mechanism of Mo delivery

  18. Cross flow cyclonic flotation column for coal and minerals beneficiation

    Science.gov (United States)

    Lai, Ralph W.; Patton, Robert A.

    2000-01-01

    An apparatus and process for the separation of coal from pyritic impurities using a modified froth flotation system. The froth flotation column incorporates a helical track about the inner wall of the column in a region intermediate between the top and base of the column. A standard impeller located about the central axis of the column is used to generate a centrifugal force thereby increasing the separation efficiency of coal from the pyritic particles and hydrophillic tailings.

  19. Partial strengthening of R.C square columns using CFRP

    Directory of Open Access Journals (Sweden)

    Ahmed Shaban Abdel-Hay

    2014-12-01

    An experimental program was undertaken testing ten square columns 200 × 200 × 2000 mm. One of them was a control specimen and the other nine specimens were strengthened with CFRP. The main parameters studied in this research were the compressive strength of the upper part, the height of the upper poor concrete part, and the height of CFRP wrapped part of column. The experimental results including mode of failure, ultimate load, concrete strain, and fiber strains were analyzed. The main conclusion of this research was, partial strengthening of square column using CFRP can be permitted and gives good results of the column carrying capacity.

  20. Fire response of composite columns subject to sway

    DEFF Research Database (Denmark)

    Virdi, Kuldeep

    Composite columns, using profiled steel sections encased in concrete or steel tubes filled with concrete, are increasingly used in practice taking advantage of speed of erection as well as offering cost-effective solutions. While the design of braced and unbraced composite columns under ambient...... conditions is adequately covered in the relevant standard, Eurocode 4, simplified design of unbraced composite columns for the fire limit state has not been included. Recognising this, a collaborative research project was undertaken with funding from the Research Fund for Coal and Steel. The paper describes...... the scope of the project which covered control tests under ambient conditions, carried out by the author while at City University London. Other aspects covered in the project included fire tests carried out by CTICM in France, on isolated columns and on two frames designed by Leibniz Universität Hannover...

  1. An autopsy case of right ventricular cardiac metastasis from squamous cell carcinoma of the left hand

    Directory of Open Access Journals (Sweden)

    T. Kondo

    2016-12-01

    Full Text Available We here report a 60-year-old woman in whom autopsy revealed a metastasis in the right cardiac ventricle from a well-differentiated squamous cell carcinoma (SCC of the left hand. The tumors in the myocardium and left hand were both well-differentiated SCCs with keratinization and sporadic keratin pearls. High concentrations of heart failure markers together with a pericardial effusion suggested antemortem chronic heart failure. Our case is particularly unusual because there were no regional lymph node metastases and the cardiac metastasis was not one of multiple metastases; thus, hematogenous metastasis to the right side of the heart alone had occurred.

  2. The Fire Resistance Performance of Recycled Aggregate Concrete Columns with Different Concrete Compressive Strengths.

    Science.gov (United States)

    Dong, Hongying; Cao, Wanlin; Bian, Jianhui; Zhang, Jianwei

    2014-12-08

    In order to ascertain the fire resistance performance of recycled aggregate concrete (RAC) components with different concrete compressive strengths, four full-scaled concrete columns were designed and tested under high temperature. Two of the four specimens were constructed by normal concrete with compressive strength ratings of C20 and C30, respectively, while the others were made from recycled coarse aggregate (RCA) concrete of C30 and C40, respectively. Identical constant axial forces were applied to specimens while being subjected to simulated building fire conditions in a laboratory furnace. Several parameters from the experimental results were comparatively analyzed, including the temperature change, vertical displacement, lateral deflection, fire endurance, and failure characteristics of specimens. The temperature field of specimens was simulated with ABAQUS Software (ABAQUS Inc., Provindence, RI, USA) and the results agreed quite well with those from the experiments. Results show that the rate of heat transfer from the surface to the interior of the column increases with the increase of the concrete's compressive strength for both RAC columns and normal concrete columns. Under the same initial axial force ratio, for columns with the same cross section, those with lower concrete compressive strengths demonstrate better fire resistance performance. The fire resistance performance of RAC columns is better than that of normal concrete columns, with the same concrete compressive strength.

  3. The Fire Resistance Performance of Recycled Aggregate Concrete Columns with Different Concrete Compressive Strengths

    Science.gov (United States)

    Dong, Hongying; Cao, Wanlin; Bian, Jianhui; Zhang, Jianwei

    2014-01-01

    In order to ascertain the fire resistance performance of recycled aggregate concrete (RAC) components with different concrete compressive strengths, four full-scaled concrete columns were designed and tested under high temperature. Two of the four specimens were constructed by normal concrete with compressive strength ratings of C20 and C30, respectively, while the others were made from recycled coarse aggregate (RCA) concrete of C30 and C40, respectively. Identical constant axial forces were applied to specimens while being subjected to simulated building fire conditions in a laboratory furnace. Several parameters from the experimental results were comparatively analyzed, including the temperature change, vertical displacement, lateral deflection, fire endurance, and failure characteristics of specimens. The temperature field of specimens was simulated with ABAQUS Software (ABAQUS Inc., Provindence, RI, USA) and the results agreed quite well with those from the experiments. Results show that the rate of heat transfer from the surface to the interior of the column increases with the increase of the concrete’s compressive strength for both RAC columns and normal concrete columns. Under the same initial axial force ratio, for columns with the same cross section, those with lower concrete compressive strengths demonstrate better fire resistance performance. The fire resistance performance of RAC columns is better than that of normal concrete columns, with the same concrete compressive strength. PMID:28788279

  4. Supervisory Model Predictive Control of the Heat Integrated Distillation Column

    DEFF Research Database (Denmark)

    Meyer, Kristian; Bisgaard, Thomas; Huusom, Jakob Kjøbsted

    2017-01-01

    This paper benchmarks a centralized control system based on model predictive control for the operation of the heat integrated distillation column (HIDiC) against a fully decentralized control system using the most complete column model currently available in the literature. The centralized control...... system outperforms the decentralized system, because it handles the interactions in the HIDiC process better. The integral absolute error (IAE) is reduced by a factor of 2 and a factor of 4 for control of the top and bottoms compositions, respectively....

  5. Design of zeolite ion-exchange columns for wastewater treatment

    International Nuclear Information System (INIS)

    Robinson, S.M.; Arnold, W.D.; Byers, C.H.

    1991-01-01

    Oak Ridge National Laboratory plans to use chabazite zeolites for decontamination of wastewater containing parts-per-billion levels of 90 Sr and 137 Cs. Treatability studies indicate that such zeolites can remove trace amounts of 90 Sr and 137 Cs from wastewater containing high concentrations of calcium and magnesium. These studies who that zeolite system efficiency is dependent on column design and operating conditions. Previous results with bench-scale, pilot-scale, and near-full-scale columns indicate that optimized design of full-scale columns could reduce the volume of spent solids generation by one-half. The data indicate that shortcut scale-up methods cannot be used to design columns to minimize secondary waste generation. Since the secondary waste generation rate is a primary influence on process cost effectiveness, a predictive mathematical model for column design is being developed. Equilibrium models and mass-transfer mechanisms are being experimentally determined for isothermal multicomponent ion exchange (Ca, Mg, Na, Cs, and Sr). Mathematical models of these data to determine the breakthrough curves for different column configurations and operating conditions will be used to optimize the final design of full-scale treatment plant. 32 refs., 6 figs., 3 tabs

  6. The effect of hand position on perceived finger orientation in left- and right-handers.

    Science.gov (United States)

    Fraser, Lindsey E; Harris, Laurence R

    2017-12-01

    In the absence of visual feedback, the perceived orientation of the fingers is systematically biased. In right-handers these biases are asymmetrical between the left and right hands in the horizontal plane and may reflect common functional postures for the two hands. Here we compared finger orientation perception in right- and left-handed participants for both hands, across various hand positions in the horizontal plane. Participants rotated a white line on a screen optically superimposed over their hand to indicate the perceived position of the finger that was rotated to one of seven orientations with the hand either aligned with the body midline, aligned with the shoulder, or displaced by twice the shoulder-to-midline distance from the midline. We replicated the asymmetric pattern of biases previously reported in right-handed participants (left hand biased towards an orientation ~30° inward, right hand ~10° inward). However, no such asymmetry was found for left-handers, suggesting left-handers may use different strategies when mapping proprioception to body or space coordinates and/or have less specialization of function between the hands. Both groups' responses rotated further outward as distance of the hand from the body midline increased, consistent with other research showing spatial orientation estimates diverge outward in the periphery. Finally, for right-handers, precision of responses was best when the hand was aligned with the shoulder compared to the other two conditions. These results highlight the unique role of hand dominance and hand position in perception of finger orientation, and provide insight into the proprioceptive position sense of the upper limbs.

  7. Cervical column morphology and craniofacial profiles in monozygotic twins.

    Science.gov (United States)

    Sonnesen, Liselotte; Pallisgaard, Carsten; Kjaer, Inger

    2008-02-01

    Previous studies have described the relationships between cervical column morphology and craniofacial morphology. The aims of the present study were to describe cervical column morphology in 38 pairs of adult monozygotic (MZ) twins, and compare craniofacial morphology in twins with fusions with craniofacial morphology in twins without fusion. Visual assessment of cervical column morphology and cephalometric measurements of craniofacial morphology were performed on profile radiographs. In the cervical column, fusion between corpora of the second and third vertebrae was registered as fusion. In the twin group, 8 twin pairs had fusion of the cervical column in both individuals within the pair (sub-group A), 25 pairs had no fusions (subgroup B), and in 5 pairs, cervical column morphology was different within the pair (subgroup C), as one twin had fusion and the other did not. Comparison of craniofacial profiles showed a tendency to increased jaw retrognathia, larger cranial base angle, and larger mandibular inclination in subgroup A than in subgroup B. The same tendency was observed within subgroup C between the individual twins with fusion compared with those without fusion. These results confirm that cervical fusions and craniofacial morphology may be interrelated in twins when analysed on profile radiographs. The study also documents that differences in cervical column morphology can occur in individuals within a pair of MZ twins. It illustrates that differences in craniofacial morphology between individuals within a pair of MZ twins can be associated with cervical fusion.

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

    Science.gov (United States)

    Abia, Jude A; Mriziq, Khaled S; Guiochon, Georges A

    2009-04-10

    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 4.6mm C18 bonded silica-based monolithic column, a 150 mm x 4.6mm column packed with 2.7 microm porous shell particles of C18 bonded silica (HALO), and a 150 mm x 4.6mm column packed with 3 microm 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.

  9. Irradiation facilities on the TRIGA-SSR thermal column

    Energy Technology Data Exchange (ETDEWEB)

    Roth, C; Aioanei, L; Preda, M; Gugiu, D [Institute for Nuclear Research, Pitesti (Romania); Garlea, I; Kelerman, C; Garlea, C [SENDRA ' Nuclear Technologies' ltd. Bucharest (Romania)

    2004-07-01

    The development of thermal and intermediate energy neutron irradiation facilities at the steady state core of the Romanian TRIGA Reactor is described. The reference thermal neutron irradiation facility consists of a dry spherical cavity placed into the graphite thermal column of the SSR core and the intermediate energy neutron irradiation facility is a {sigma}{sigma} system located into the thermal flux cavity. The implementation of the irradiation facilities into the under-water thermal column represented an important challenge from the standpoint of instrumentation solutions. The neutron flux and spectrum measurements were performed using foil activation techniques and fission rate measurements by sealed fission chambers, followed by spectrum unfolding procedure. The absolute fission reaction measurements, using calibrated fission chambers, allow the neutron flux density unit transfer from international reference neutron fields. The MCNP-4C code package was used for neutron spectrum computations in the thermal flux cavity and in the {sigma}{sigma} system. The neutron characterization program demonstrates the accuracy of the spectrum characteristics and neutron flux densities reported to the local monitoring system count rates. Some discrepancies, as compared to other similar facilities, were identified and discussed. These are caused by thermal column particularities: the presence of a water layer between the graphite cells (thermal neutron absorption) and smaller geometrical dimensions (neutron escape phenomena). Based on these results the metrological certification process, according to Romanian metrological laws requirements, is now in progress. (nevyjel)

  10. Applicability of hydroxylamine nitrate reductant in pulse-column contactors

    International Nuclear Information System (INIS)

    Reif, D.J.

    1983-05-01

    Uranium and plutonium separations were made from simulated breeder reactor spent fuel dissolver solution with laboratory-sized pulse column contactors. Hydroxylamine nitrate (HAN) was used for reduction of plutonium (1V). An integrated extraction-partition system, simulating a breeder fuel reprocessing flowsheet, carried out a partial partition of uranium and plutonium in the second contactor. Tests have shown that acceptable coprocessing can be ontained using HAN as a plutonium reductant. Pulse column performance was stable even though gaseous HAN oxidation products were present in the column. Gas evolution rates up to 0.27 cfm/ft 2 of column cross section were tested and found acceptable

  11. A new variant of aberrant left brachiocephalic trunk in mam: case report and literature review.

    Science.gov (United States)

    Szpinda, Michał

    2005-02-01

    Importance is placed on aberrant arteries in the radiological and surgical literature. A normal left brachiocephalic trunk is characteristic for the right aortic arch. However, an aberrant left brachiocephalic trunk arising as the last branch of the aortic arch on the left side has not yet been described in the literature. Described here is a new variant of the retro-oesophageal aberrant left brachiocephalic trunk, occasionally observed in a patient during diagnostic investigation or surgical treatment for steno-obstructive involvement of the carotid district. The triple anomaly of the left aortic arch consisted of: 1. the presence of a hypoplastic left brachiocephalic trunk behind the oesophagus, 2. the absence of a brachiocephalic trunk on the right side and 3. separate origins of the arteries on the right side, with the right common artery preceding the right subclavian artery. In front of the trachea an 8-mm prosthetic PTFE was implanted from the proximal segment of the right subclavian artery to the junction of the left common carotid and left subclavian arteries. The author demonstrates the inadequacy of auxiliary investigations to detect aberrant arteries, which may only be identified precisely intra-operatively.

  12. Left preference for sport tasks does not necessarily indicate left-handedness: sport-specific lateral preferences, relationship with handedness and implications for laterality research in behavioural sciences.

    Directory of Open Access Journals (Sweden)

    Florian Loffing

    Full Text Available In the elite domain of interactive sports, athletes who demonstrate a left preference (e.g., holding a weapon with the left hand in fencing or boxing in a 'southpaw' stance seem overrepresented. Such excess indicates a performance advantage and was also interpreted as evidence in favour of frequency-dependent selection mechanisms to explain the maintenance of left-handedness in humans. To test for an overrepresentation, the incidence of athletes' lateral preferences is typically compared with an expected ratio of left- to right-handedness in the normal population. However, the normal population reference values did not always relate to the sport-specific tasks of interest, which may limit the validity of reports of an excess of 'left-oriented' athletes. Here we sought to determine lateral preferences for various sport-specific tasks (e.g., baseball batting, boxing in the normal population and to examine the relationship between these preferences and handedness. To this end, we asked 903 participants to indicate their lateral preferences for sport-specific and common tasks using a paper-based questionnaire. Lateral preferences varied considerably across the different sport tasks and we found high variation in the relationship between those preferences and handedness. In contrast to unimanual tasks (e.g., fencing or throwing, for bimanually controlled actions such as baseball batting, shooting in ice hockey or boxing the incidence of left preferences was considerably higher than expected from the proportion of left-handedness in the normal population and the relationship with handedness was relatively low. We conclude that (i task-specific reference values are mandatory for reliably testing for an excess of athletes with a left preference, (ii the term 'handedness' should be more cautiously used within the context of sport-related laterality research and (iii observation of lateral preferences in sports may be of limited suitability for the

  13. Left preference for sport tasks does not necessarily indicate left-handedness: sport-specific lateral preferences, relationship with handedness and implications for laterality research in behavioural sciences.

    Science.gov (United States)

    Loffing, Florian; Sölter, Florian; Hagemann, Norbert

    2014-01-01

    In the elite domain of interactive sports, athletes who demonstrate a left preference (e.g., holding a weapon with the left hand in fencing or boxing in a 'southpaw' stance) seem overrepresented. Such excess indicates a performance advantage and was also interpreted as evidence in favour of frequency-dependent selection mechanisms to explain the maintenance of left-handedness in humans. To test for an overrepresentation, the incidence of athletes' lateral preferences is typically compared with an expected ratio of left- to right-handedness in the normal population. However, the normal population reference values did not always relate to the sport-specific tasks of interest, which may limit the validity of reports of an excess of 'left-oriented' athletes. Here we sought to determine lateral preferences for various sport-specific tasks (e.g., baseball batting, boxing) in the normal population and to examine the relationship between these preferences and handedness. To this end, we asked 903 participants to indicate their lateral preferences for sport-specific and common tasks using a paper-based questionnaire. Lateral preferences varied considerably across the different sport tasks and we found high variation in the relationship between those preferences and handedness. In contrast to unimanual tasks (e.g., fencing or throwing), for bimanually controlled actions such as baseball batting, shooting in ice hockey or boxing the incidence of left preferences was considerably higher than expected from the proportion of left-handedness in the normal population and the relationship with handedness was relatively low. We conclude that (i) task-specific reference values are mandatory for reliably testing for an excess of athletes with a left preference, (ii) the term 'handedness' should be more cautiously used within the context of sport-related laterality research and (iii) observation of lateral preferences in sports may be of limited suitability for the verification of

  14. Left Preference for Sport Tasks Does Not Necessarily Indicate Left-Handedness: Sport-Specific Lateral Preferences, Relationship with Handedness and Implications for Laterality Research in Behavioural Sciences

    Science.gov (United States)

    Loffing, Florian; Sölter, Florian; Hagemann, Norbert

    2014-01-01

    In the elite domain of interactive sports, athletes who demonstrate a left preference (e.g., holding a weapon with the left hand in fencing or boxing in a ‘southpaw’ stance) seem overrepresented. Such excess indicates a performance advantage and was also interpreted as evidence in favour of frequency-dependent selection mechanisms to explain the maintenance of left-handedness in humans. To test for an overrepresentation, the incidence of athletes' lateral preferences is typically compared with an expected ratio of left- to right-handedness in the normal population. However, the normal population reference values did not always relate to the sport-specific tasks of interest, which may limit the validity of reports of an excess of ‘left-oriented’ athletes. Here we sought to determine lateral preferences for various sport-specific tasks (e.g., baseball batting, boxing) in the normal population and to examine the relationship between these preferences and handedness. To this end, we asked 903 participants to indicate their lateral preferences for sport-specific and common tasks using a paper-based questionnaire. Lateral preferences varied considerably across the different sport tasks and we found high variation in the relationship between those preferences and handedness. In contrast to unimanual tasks (e.g., fencing or throwing), for bimanually controlled actions such as baseball batting, shooting in ice hockey or boxing the incidence of left preferences was considerably higher than expected from the proportion of left-handedness in the normal population and the relationship with handedness was relatively low. We conclude that (i) task-specific reference values are mandatory for reliably testing for an excess of athletes with a left preference, (ii) the term ‘handedness’ should be more cautiously used within the context of sport-related laterality research and (iii) observation of lateral preferences in sports may be of limited suitability for the

  15. Analysis of packing microstructure and wall effects in a narrow-bore ultrahigh pressure liquid chromatography column using focused ion-beam scanning electron microscopy.

    Science.gov (United States)

    Reising, Arved E; Schlabach, Sabine; Baranau, Vasili; Stoeckel, Daniela; Tallarek, Ulrich

    2017-09-01

    Column wall effects are well recognized as major limiting factor in achieving high separation efficiency in HPLC. This is especially important for modern analytical columns packed with small particles, where wall effects dominate the band broadening. Detailed knowledge about the packing microstructure of packed analytical columns has so far not been acquired. Here, we present the first three-dimensional reconstruction protocol for these columns utilizing focused ion-beam scanning electron microscopy (FIB-SEM) on a commercial 2.1mm inner diameter×50mm length narrow-bore analytical column packed with 1.7μm bridged-ethyl hybrid silica particles. Two sections from the packed bed are chosen for reconstruction by FIB-SEM: one from the bulk packing region of the column and one from its critical wall region. This allows quantification of structural differences between the wall region and the center of the bed due to effects induced by the hard, confining column wall. Consequences of these effects on local flow velocity in the column are analyzed with flow simulations utilizing the lattice-Boltzmann method. The reconstructions of the bed structures reveal significant structural differences in the wall region (extending radially over approximately 62 particle diameters) compared to the center of the column. It includes the local reduction of the external porosity by up to 10% and an increase of the mean particle diameter by up to 3%, resulting in a decrease of the local flow velocity by up to 23%. In addition, four (more ordered) layers of particles in the direct vicinity of the column wall induce local velocity fluctuations by up to a factor of three regarding the involved velocity amplitudes. These observations highlight the impact of radial variations in packing microstructure on band migration and column performance. This knowledge on morphological peculiarities of column wall effects helps guiding us towards further optimization of the packing process for analytical

  16. Biomechanical analysis of the fixation systems for anterior column and posterior hemi-transverse acetabular fractures.

    Science.gov (United States)

    Lei, Jianyin; Dong, Pengfei; Li, Zhiqiang; Zhu, Feng; Wang, Zhihua; Cai, Xianhua

    2017-05-01

    The aim of this study was to evaluate the biomechanical properties of common fixation systems for complex acetabular fractures. A finite element (FE) pelvic model with anterior column and posterior hemi-transverse acetabular fractures was created. Three common fixation systems were used to fix the posterior wall acetabular fractures: 1. Anterior column plate combined with posterior column screws (group I), 2. Anterior column plate combined with quadrilateral area screws (group II) and 3. Double-column plates (group III). And 600 N, representing the body weight, was loaded on the upper surface of the sacrum to simulate the double-limb stance. The amounts of total and relative displacements were compared between the groups. The total amount of displacement was 2.76 mm in group II, 2.81 mm in group III, and 2.83 mm in group I. The amount of relative displacement was 0.0078 mm in group II, 0.0093 mm in group III and 0.014 mm in group I. Our results suggested that all fixation systems enhance biomechanical stability significantly. Anterior column plate combined with quadrilateral area screws has quite comparable results to double column plates, they were superior to anterior column plate combined with posterior screws. Copyright © 2017 Turkish Association of Orthopaedics and Traumatology. Production and hosting by Elsevier B.V. All rights reserved.

  17. Relating pressure tuned coupled column ensembles with the solvation parameter model for tunable selectivity in gas chromatography.

    Science.gov (United States)

    Sharif, Khan M; Kulsing, Chadin; Chin, Sung-Tong; Marriott, Philip J

    2016-07-15

    The differential pressure drop of carrier gas by tuning the junction point pressure of a coupled column gas chromatographic system leads to a unique selectivity of the overall separation, which can be tested using a mixture of compounds with a wide range of polarity. This study demonstrates a pressure tuning (PT) GC system employing a microfluidic Deans switch located at the mid-point of the two capillary columns. This PT system allowed variations of inlet-outlet pressure differences of the two columns in a range of 52-17psi for the upstream column and 31-11psi for the downstream column. Peak shifting (differential migration) of compounds due to PT difference are related to a first order regression equation in a Plackett-Burman factorial study. Increased first (upstream) column pressure drop makes the second column characteristics more significant in the coupled column retention behavior, and conversely increased second (downstream) column pressure drop makes the first column characteristics more apparent; such variation can result in component swapping between polar and non-polar compounds. The coupled column system selectivity was evaluated in terms of linear solvation energy relationship (LSER) parameters, and their relation with different pressure drop effects has been constructed by applying multivariate principle component analysis (PCA). It has been found that the coupled column PT system descriptors provide a result that shows a clear clustering of different pressure settings, somewhat intermediate between those of the two commercial columns. This is equivalent to that obtained from a conventional single-column GC analysis where the interaction energy contributed from the stationary phases can be significantly adjusted by choice of midpoint PT. This result provides a foundation for pressure differentiation for selectivity enhancement. Copyright © 2016 Elsevier B.V. All rights reserved.

  18. Seismic performance of recycled concrete-filled square steel tube columns

    Science.gov (United States)

    Chen, Zongping; Jing, Chenggui; Xu, Jinjun; Zhang, Xianggang

    2017-01-01

    An experimental study on the seismic performance of recycled concrete-filled square steel tube (RCFST) columns is carried out. Six specimens were designed and tested under constant axial compression and cyclic lateral loading. Two parameters, replacement percentage of recycled coarse aggregate (RCA) and axial compression level, were considered in the test. Based on the experimental data, the hysteretic loops, skeleton curves, ductility, energy dissipation capacity and stiffness degradation of RCFST columns were analyzed. The test results indicate that the failure modes of RCFST columns are the local buckling of the steel tube at the bottom of the columns, and the hysteretic loops are full and their shapes are similar to normal CFST columns. Furthermore, the ductility coefficient of all specimens are close to 3.0, and the equivalent viscous damping coefficient corresponding to the ultimate lateral load ranges from 0.323 to 0.360, which demonstrates that RCFST columns exhibit remarkable seismic performance.

  19. Characterization of retentivity of reversed phase liquid chromatography columns.

    Science.gov (United States)

    Ying, P T; Dorsey, J G

    1991-03-01

    There are dozens of commercially available reversed phase columns, most marketed as C-8 or C-18 materials, but with no useful way of classifying their retentivity. A useful way of ranking these columns in terms of column "strength" or retentivity is presented. The method utilizes a value for ln k'(w), the estimated retention of a solute from a mobile phase of 100% water, and the slope of the plot of ln k' vsE(T)(30), the solvent polarity. The method is validated with 26 solutes varying in ln k'(w) from about 2 to over 20, on 14 different reversed phase columns. In agreement with previous work, it is found that the phase volume ratio of the column is the most important parameter in determining retentivity. It is strongly suggested that manufacturers adopt a uniform method of calculating this value and that it be made available in advertising, rather than the uninterpretable "% carbon".

  20. Mining Genome-Scale Growth Phenotype Data through Constant-Column Biclustering

    KAUST Repository

    Alzahrani, Majed A.

    2017-07-10

    Growth phenotype profiling of genome-wide gene-deletion strains over stress conditions can offer a clear picture that the essentiality of genes depends on environmental conditions. Systematically identifying groups of genes from such recently emerging high-throughput data that share similar patterns of conditional essentiality and dispensability under various environmental conditions can elucidate how genetic interactions of the growth phenotype are regulated in response to the environment. In this dissertation, we first demonstrate that detecting such “co-fit” gene groups can be cast as a less well-studied problem in biclustering, i.e., constant-column biclustering. Despite significant advances in biclustering techniques, very few were designed for mining in growth phenotype data. Here, we propose Gracob, a novel, efficient graph-based method that casts and solves the constant-column biclustering problem as a maximal clique finding problem in a multipartite graph. We compared Gracob with a large collection of widely used biclustering methods that cover different types of algorithms designed to detect different types of biclusters. Gracob showed superior performance on finding co-fit genes over all the existing methods on both a variety of synthetic data sets with a wide range of settings, and three real growth phenotype data sets for E. coli, proteobacteria, and yeast.

  1. Tritium isotope separation by water distillation column packed with silica-gel beads

    International Nuclear Information System (INIS)

    Fukada, Satoshi

    2004-01-01

    Tritium enrichment or depletion by water distillation was investigated using a glass column of 32cm in height packed with silica-gel beads of 3.4mm in average diameter. The total separation factor of the silica-gel distillation column, α H-T , was compared with those of an open column distillation tower and of a column packed with stainless-steel Dixon rings. Depletion of the tritium activity in the distillate was enhanced by isotopic exchange with water absorbed on silica-gel beads that have a higher affinity for HTO than for H 2 O. The value of α H-T -1 of the silica-gel distillation column was about four times larger than that of a column without any packing and about two times larger than that of the Dixon-ring column. The improvement of α H-T by the silica-gel adsorbent indicated that the height of the distillation-adsorption column becomes shorter than that of the height of conventional distillation columns. (author)

  2. The hydrodynamic drag and the mobilisation of sediment into the water column of towed fishing gear components

    Science.gov (United States)

    O'Neill, F. G.; Summerbell, Keith David

    2016-12-01

    The hydrodynamic drag of towed fishing gears leads to direct impacts on the benthic environment, and can play a major role in the overall economic efficiency of the fishing operation and emissions of nitrogen oxides, sulphur oxides and greenhouse gases such as CO2. Here we investigate some of the underpinning processes which govern these issues and make direct hydrodynamic drag measurements and calculate the hydrodynamic drag coefficients for a range of well-defined gear components that, when fished, are in contact with the seabed. We measure the concentration and particle size distribution of the sediment mobilised into the water column in the wake of these gear elements, at a range of towing speeds, and demonstrate that as the hydrodynamic drag increases the amount of sediment mobilised also increases. We also vary the weight of the elements and show that this does not influence the amount of sediment put into the water column. These results provide a better understanding of the physical and mechanical processes that take place when a towed fishing gear interacts with the seabed. They will permit the development of more fuel efficient gears and gears of reduced benthic impact and will improve the empirical modelling of the sediment mobilised into the turbulent wake behind towed fishing gears which will lead to better assessments of the environmental and ecological impact of fishing gears.

  3. Numerical Evaluation on the Different Shapes of Gravelly Sand Columns to Increase the Loading Capacity of Soft Clay

    Directory of Open Access Journals (Sweden)

    Meghzili Sif Allah

    2017-01-01

    Full Text Available Improvement on soft clay by the installation of stone column is one of the most popular methods followed worldwide. Different analytical and numerical solutions have already been developed for understanding the load transfer mechanism of soft soil reinforced with stone column. This study investigated a bearing capacity of the gravelly sand column, installed in soft clay bed at 15kpa of undrained shear strength. The column variable of length and diameter ratio at 7, 8 and 9 were evaluated. On top of that, the combination of two diameters in single column was tested and the uniform diameter was used as a control. In the numerical analysis, Mohrcoulomb model was adopted in the idealization of the behaviour of the gravelly sand column and soft clay materials. The results revealed that the optimum design that gave the highest loading capacity of the combination 11=12 of column diameter was the length and diameter ratio of 8.

  4. Short steel and concrete columns under high temperatures

    Directory of Open Access Journals (Sweden)

    A. E. P. G. A. Jacintho

    Full Text Available The growing demand for knowledge about the effect of high temperatures on structures has stimulated increasing research worldwide. This article presents experimental results for short composite steel and concrete columns subjected to high temperatures in ovens with or without an axial compression load, numerically analyzes the temperature distribution in these columns after 30 and 60 minutes and compares them with experimental results. The models consist of concrete-filled tubes of three different thicknesses and two different diameters, and the concrete fill has conventional properties that remained constant for all of the models. The stress-strain behavior of the composite columns was altered after exposure to high temperatures relative to the same columns at room temperature, which was most evident in the 60-minute tests due to the higher temperatures reached. The computational analysis adopted temperature rise curves that were obtained experimentally.

  5. The left ventricle as a mechanical engine: from Leonardo da Vinci to the echocardiographic assessment of peak power output-to-left ventricular mass.

    Science.gov (United States)

    Dini, Frank L; Guarini, Giacinta; Ballo, Piercarlo; Carluccio, Erberto; Maiello, Maria; Capozza, Paola; Innelli, Pasquale; Rosa, Gian M; Palmiero, Pasquale; Galderisi, Maurizio; Razzolini, Renato; Nodari, Savina

    2013-03-01

    The interpretation of the heart as a mechanical engine dates back to the teachings of Leonardo da Vinci, who was the first to apply the laws of mechanics to the function of the heart. Similar to any mechanical engine, whose performance is proportional to the power generated with respect to weight, the left ventricle can be viewed as a power generator whose performance can be related to left ventricular mass. Stress echocardiography may provide valuable information on the relationship between cardiac performance and recruited left ventricular mass that may be used in distinguishing between adaptive and maladaptive left ventricular remodeling. Peak power output-to-mass, obtained during exercise or pharmacological stress echocardiography, is a measure that reflects the number of watts that are developed by 100 g of left ventricular mass under maximal stimulation. Power output-to-mass may be calculated as left ventricular power output per 100 g of left ventricular mass: 100× left ventricular power output divided by left ventricular mass (W/100 g). A simplified formula to calculate power output-to-mass is as follows: 0.222 × cardiac output (l/min) × mean blood pressure (mmHg)/left ventricular mass (g). When the integrity of myocardial structure is compromised, a mismatch becomes apparent between maximal cardiac power output and left ventricular mass; when this occurs, a reduction of the peak power output-to-mass index is observed.

  6. HPLC separation of triacylglycerol positional isomers on a polymeric ODS column.

    Science.gov (United States)

    Kuroda, Ikuma; Nagai, Toshiharu; Mizobe, Hoyo; Yoshimura, Nobuhito; Gotoh, Naohiro; Wada, Shun

    2008-07-01

    A polymeric ODS column was applied to the resolution of triacylglycerol positional isomers (TAG-PI), i.e. 1,3-dioleoyl-2-palmitoyl-glycerol (OPO) and 1,2-dioleoyl-3-palmitoyl-rac-glycerol (OOP), with a recycle HPLC system. To investigate the ODS column species and the column temperatures for the resolution of a TAG-PI pair, a mixture of OPO and OOP was subjected to an HPLC system equipped with a non-endcapped polymeric, endcapped monomeric, endcapped intermediate, or non-endcapped monomeric ODS column at three different column temperatures (40, 25, or 10 degrees C). Only the non-endcapped polymeric ODS column achieved the separation of OPO and OOP, and the lowest column temperature (10 degrees C) showed the best resolution for them. The other pair of TAG-PI, a mixture of 1,3-dipalmitoyl-2-oleoyl-glycerol (POP) and 1,2-dipalmitoyl-3-oleoyl-rac-glycerol (PPO) was also subjected to the system equipped with a non-endcapped polymeric or monomeric ODS column at five different column temperatures (40, 32, 25, 17, and 10 degrees C). Thus, POP and PPO were also separated on only the non-endcapped polymeric ODS column at 25 degrees C. However, no clear peak appeared at 10 degrees C. These results would indicate that the polymeric ODS stationary phase has an ability to recognize the structural differences between TAG-PI pairs. Also, the column temperature is a very important factor for separating the TAG-PI pair, and the optimal temperature would relate to the solubility of TAG-PI in the mobile phase. Furthermore, the recycle HPLC system provided measurements for the separation and analysis of TAG-PI pairs.

  7. Bubble column fermenter modeling: a comparison for pressure effects

    Energy Technology Data Exchange (ETDEWEB)

    Shioya, S; Dang, N D.P.; Dunn, I J

    1978-01-01

    Two models which describe the oxygen transfer, oxygen uptake, and axial mixing in a bubble column fermenter are described. Model I includes no pressure effects and can be solved analytically. Model II incorporates the influence of hydrostatic pressure on oxygen solubility and gas expansion and must be solved numerically. The liquid phase oxygen concentration profiles from both models are compared to ascertain for what parametric conditions and for what maximum column height Model I is valid. Results show that for many situations Model I can approximate the oxygen profiles in a 10 m column within 20%. As the transfer and uptake rates increase, the deviation of Model I can reach 80% for a 10 m column. 7 figures.

  8. Calculation code PULCO for Purex process in pulsed column

    International Nuclear Information System (INIS)

    Gonda, Kozo; Matsuda, Teruo

    1982-03-01

    The calculation code PULCO, which can simulate the Purex process using a pulsed column as an extractor, has been developed. The PULCO is based on the fundamental concept of mass transfer that the mass transfer within a pulsed column occurs through the interface of liquid drops and continuous phase fluid, and is the calculation code different from conventional ones, by which various phenomena such as the generation of liquid drops, their rising and falling, and the unification of liquid drops actually occurring in a pulsed column are exactly reflected and can be correctly simulated. In the PULCO, the actually measured values of the fundamental quantities representing the extraction behavior of liquid drops in a pulsed column are incorporated, such as the mass transfer coefficient of each component, the diameter and velocity of liquid drops in a pulsed column, the holdup of dispersed phase, and axial turbulent flow diffusion coefficient. The verification of the results calculated with the PULCO was carried out by installing a pulsed column of 50 mm inside diameter and 2 m length with 40 plate stage in a glove box for unirradiated uranium-plutonium mixed system. The results of the calculation and test were in good agreement, and the validity of the PULCO was confirmed. (Kako, I.)

  9. Distillation columns inspection through gamma scanning

    International Nuclear Information System (INIS)

    Garcia, Marco

    1999-09-01

    The application of nuclear energy is very wide and it allows the saving of economic resources since the investigation of a certain process is carried out without stop the plant. The gamma scanning of oil c racking c olumns are practical examples, they allow to determine the hydraulic operation of the inspected columns. A source of Co-60 22mCi and a detector with a crystal of INa(TI) are used. This paper shows the results got from a profile carried out in a column distillation

  10. The Medial Temporal Lobe and the Left Inferior Prefrontal Cortex Jointly Support Interference Resolution in Verbal Working Memory

    Science.gov (United States)

    Oztekin, Ilke; Curtis, Clayton E.; McElree, Brian

    2009-01-01

    During working memory retrieval, proactive interference (PI) can be induced by semantic similarity and episodic familiarity. Here, we used fMRI to test hypotheses about the role of the left inferior frontal gyrus (LIFG) and the medial temporal lobe (MTL) regions in successful resolution of PI. Participants studied six-word lists and responded to a…

  11. THE PERFORMANCE ANALYSIS OF A PACKED COLUMN : CALIBRATION OF AN ORIFICE

    Directory of Open Access Journals (Sweden)

    Aynur ŞENOL

    2003-01-01

    Full Text Available Investigations to develop data for this study were made using a pilot scale glass column of 9 cm inside diameter randomly filled to a depth of 1.90 cm with a Raschig type ring at a slightly modified geometry. The geometrical characteristics of packing are: the total area of a single particle ad = 2.3 cm2; specific area ap = 10.37 cm2/cm3; voidage ? = 0.545 m3/m3. The efficiency tests were run using trichloroethylene/n-heptane system under total reflux conditions. Using the modified versions of the Eckert flooding model and the Bravo effective area (ae approach, as well as the Onda wetted area (aw and individual mass transfer coefficient models, it has been attempted to estimate the packing efficiency theoretically. This article also deals with the design strategies attributed to a randomly packed column. Emphasis is mainly placed on the way to formulate an algorithm of designing a pilot scale column through the models being attributed to the film theory. Using the column dry pressure drop properties based on the air flowing it has been achieved a generalized flow rate approach for calibrating of an orifice through which the air passes.

  12. Apraxia and spatial inattention dissociate in left hemisphere stroke.

    Science.gov (United States)

    Timpert, David C; Weiss, Peter H; Vossel, Simone; Dovern, Anna; Fink, Gereon R

    2015-10-01

    Theories of lateralized cognitive functions propose a dominance of the left hemisphere for motor control and of the right hemisphere for spatial attention. Accordingly, spatial attention deficits (e.g., neglect) are more frequently observed after right-hemispheric stroke, whereas apraxia is a common consequence of left-hemispheric stroke. Clinical reports of spatial attentional deficits after left hemisphere (LH) stroke also exist, but are often neglected. By applying parallel analysis (PA) and voxel-based lesion-symptom mapping (VLSM) to data from a comprehensive neuropsychological assessment of 74 LH stroke patients, we here systematically investigate the relationship between spatial inattention and apraxia and their neural bases. PA revealed that apraxic (and language comprehension) deficits loaded on one common component, while deficits in attention tests were explained by another independent component. Statistical lesion analyses with the individual component scores showed that apraxic (and language comprehension) deficits were significantly associated with lesions of the left superior longitudinal fascicle (SLF). Data suggest that in LH stroke spatial attention deficits dissociate from apraxic (and language comprehension) deficits. These findings contribute to models of lateralised cognitive functions in the human brain. Moreover, our findings strongly suggest that LH stroke patients should be assessed systematically for spatial attention deficits so that these can be included in their rehabilitation regime. Copyright © 2015 Elsevier Ltd. All rights reserved.

  13. Investigating the efficiency of using the carbon fiber polymer on beam–column connection

    Directory of Open Access Journals (Sweden)

    Mahmoud M. Eldeeb

    2016-03-01

    Full Text Available Due to the huge amount of energy induced from earthquakes, such natural hazards usually represent the most significant threat on existing and new buildings. Recently, a lot of considerable efforts were dedicated to design buildings capable of withstanding earthquakes' ground motions by utilizing lateral resisting elements, such as reinforced concrete shear walls, cores, frames, and steel bracing. Contrasting the experience gained from the previously designed guidelines and provisions for lateral resisting systems, recent studies illustrated that the existence of lateral resisting system in low-rise buildings is essential in order to resist ground motions. As such, some endeavors are directed to reinforce old buildings against seismic loads. This paper focuses on investigating the efficiency of using Carbon Fiber Polymer (CFRP sheets on the behavior of beam–column connections considering a cantilever beam with concentrated load at its free end. In addition, to complement the published data, finite element model using the computer package ANSYS was used. The additional beam–column connections in this study are classified in 4 groups (A, B, C, and D depending on the percentage of reinforcement at the bottom and top of the beam (%As. The efficiency of using CFRP was concluded; the CFRP sheet improves or decreases the efficiency of beam–column connection depending on %As in the beam. The paper investigates the influence of boundary condition, columns as hinged supports, and the efficiency of using CFRP. It is concluded that the CFRP sheet improves or decreases the efficiency of beam–column connection depending on %As in the beam.

  14. New strict left bundle branch block criteria reflect left ventricular activation differences

    DEFF Research Database (Denmark)

    Emerek, Kasper Janus Grønn; Risum, Niels; Hjortshøj, Søren Pihlkjær

    2015-01-01

    AIMS: Pacing lead electrical delays and strict left bundle branch block (LBBB) criteria were assessed against cardiac resynchronization therapy (CRT) outcome. METHODS: Forty-nine patients with LBBB and QRS duration >130 milliseconds underwent CRT-implantation. Sensed right ventricular to left ven....... CONCLUSION: Interventricular electrical delay predicts left ventricular remodeling after CRT and new, strict ECG criteria of LBBB are superior in predicting remodeling.......AIMS: Pacing lead electrical delays and strict left bundle branch block (LBBB) criteria were assessed against cardiac resynchronization therapy (CRT) outcome. METHODS: Forty-nine patients with LBBB and QRS duration >130 milliseconds underwent CRT-implantation. Sensed right ventricular to left...... ventricular electrical delay (RV-LV-IED) was measured. Response to CRT was defined as ≥15% decrease in left ventricular end-systolic volume. RESULTS: Eighteen of 20 (90%) patients with non-ischemic dilated cardiomyopathy (DCM) and 18 of 29 (62%) with ischemic heart disease (IHD) responded to CRT, p

  15. The life of the cortical column: opening the domain of functional architecture of the cortex (1955-1981).

    Science.gov (United States)

    Haueis, Philipp

    2016-09-01

    The concept of the cortical column refers to vertical cell bands with similar response properties, which were initially observed by Vernon Mountcastle's mapping of single cell recordings in the cat somatic cortex. It has subsequently guided over 50 years of neuroscientific research, in which fundamental questions about the modularity of the cortex and basic principles of sensory information processing were empirically investigated. Nevertheless, the status of the column remains controversial today, as skeptical commentators proclaim that the vertical cell bands are a functionally insignificant by-product of ontogenetic development. This paper inquires how the column came to be viewed as an elementary unit of the cortex from Mountcastle's discovery in 1955 until David Hubel and Torsten Wiesel's reception of the Nobel Prize in 1981. I first argue that Mountcastle's vertical electrode recordings served as criteria for applying the column concept to electrophysiological data. In contrast to previous authors, I claim that this move from electrophysiological data to the phenomenon of columnar responses was concept-laden, but not theory-laden. In the second part of the paper, I argue that Mountcastle's criteria provided Hubel Wiesel with a conceptual outlook, i.e. it allowed them to anticipate columnar patterns in the cat and macaque visual cortex. I argue that in the late 1970s, this outlook only briefly took a form that one could call a 'theory' of the cerebral cortex, before new experimental techniques started to diversify column research. I end by showing how this account of early column research fits into a larger project that follows the conceptual development of the column into the present.

  16. Dynamic response of the U-tube liquid manometer with equal diameter columns

    International Nuclear Information System (INIS)

    Zahariea, D

    2010-01-01

    The paper presents numerical solving methods using MATLAB programming language of the governing equation of the liquid oscillations in a U-tube liquid manometer with equal diameter columns. Assuming some numerical values for geometrical and functional parameters of this pressure measurement system, the dynamic behavior of the oscillating system will be analyzed using four MATLAB based computational methods: the method of the default MATLAB procedures, the Simulink method, the Simscape method and the method of the Control System Toolbox procedures. According to all these methods, in almost all the cases analyzed, the dynamic behavior of the U-tube liquid manometer with equal diameter columns corresponds to an under-damped dynamic system. The influence of some important constructive and functional parameters (the columns diameter, the manometer liquid, the capillarity action and the connection tube between the reservoir and the manometer) has been investigated. Improving the dynamic response (decreasing the overshoot and the settling time, increasing the phase and delay margins) can be achieved by increasing the connection tube length, by decreasing the columns diameter and by using a high density liquid manometer.

  17. Demonstration of motionless Knudsen pump based micro-gas chromatography featuring micro-fabricated columns and on-column detectors.

    Science.gov (United States)

    Liu, Jing; Gupta, Naveen K; Wise, Kensall D; Gianchandani, Yogesh B; Fan, Xudong

    2011-10-21

    This paper reports the investigation of a micro-gas chromatography (μGC) system that utilizes an array of miniaturized motionless Knudsen pumps (KPs) as well as microfabricated separation columns and optical detectors. A prototype system was built to achieve a flow rate of 1 mL min(-1) and 0.26 mL min(-1) for helium and dry air, respectively, when they were used as carrier gas. This system was then employed to evaluate GC performance compromises and demonstrate the ability to separate and detect gas mixtures containing analytes of different volatilities and polarities. Furthermore, the use of pressure programming of the KP array was demonstrated to significantly shorten the analysis time while maintaining a high detection resolution. Using this method, we obtained a high resolution detection of 5 alkanes of different volatilities within 5 min. Finally, we successfully detected gas mixtures of various polarities using a tandem-column μGC configuration by installing two on-column optical detectors to obtain complementary chromatograms.

  18. Column-by-column compositional mapping by Z-contrast imaging

    Energy Technology Data Exchange (ETDEWEB)

    Molina, S.I. [Departamento de Ciencia de los Materiales e I.M. y Q.I., Facultad de Ciencias, Universidad de Cadiz, Campus Rio San Pedro, s/n, 11510 Puerto Real, Cadiz (Spain)], E-mail: sergio.molina@uca.es; Sales, D.L. [Departamento de Ciencia de los Materiales e I.M. y Q.I., Facultad de Ciencias, Universidad de Cadiz, Campus Rio San Pedro, s/n, 11510 Puerto Real, Cadiz (Spain); Galindo, P.L. [Departamento de Lenguajes y Sistemas Informaticos, CASEM, Universidad de Cadiz, Campus Rio San Pedro, s/n, 11510 Puerto Real, Cadiz (Spain); Fuster, D.; Gonzalez, Y.; Alen, B.; Gonzalez, L. [Instituto de Microelectronica de Madrid (CNM, CSIC), Isaac Newton 8, 28760 Tres Cantos, Madrid (Spain); Varela, M.; Pennycook, S.J. [Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831 (United States)

    2009-01-15

    A phenomenological method is developed to determine the composition of materials, with atomic column resolution, by analysis of integrated intensities of aberration-corrected Z-contrast scanning transmission electron microscopy images. The method is exemplified for InAs{sub x}P{sub 1-x} alloys using epitaxial thin films with calibrated compositions as standards. Using this approach we have determined the composition of the two-dimensional wetting layer formed between self-assembled InAs quantum wires on InP(0 0 1) substrates.

  19. Ultimate strength and ductility of steel reinforced concrete beam-columns

    International Nuclear Information System (INIS)

    Shohara, Ryoichi

    1991-01-01

    The ultimate strength and ductility of SRC beam-columns are investigated using the data gathered in Architectural Institute of Japan. Though the simple superposed strength formula in AIJ standard underestimates the strength of SRC beam-column failed in flexure, the generalized superposed strength formula estimates it satisfactory. The strength formula in AIJ standard does not good agreement with test data. The SRC beam-column failed in shear has almost equalductility with that failed in flexure owing to the encased steel. Author presents the formulas which estimate the ultimate deformation angle for SRC beam-columns. (author)

  20. The role of sidestream recycle in hydrogen isotope separation and column cascade design

    International Nuclear Information System (INIS)

    Sherman, R.H.; Taylor, D.J.; Yamanishi, T.; Enoeda, M.; Konishi, S.; Okuno, K.

    1994-01-01

    Sidestream recycle combined with sidestream equilibration is important in hydrogen isotopic distillation processes because it offers a means to reduce the number of columns required for the extraction of pure homonuclear species. This directly implies simpler systems, reduced control problems, and reduce material inventories. Measurements were recently completed for a single distillation column using feed compositions (∼50--50 D-T) and product flows similar to those expected in an ITER type device wit recycle of an equilibrated sidestream withdrawn from the column. Dynamic studies were conducted with flowrates changing as might be expected for typical Tokamak operations. These experimental results are compared with computer simulations of the dynamic process. The impact of these sidestream recycle studies on the design of isotope separation systems is discussed, especially with respect to column design, tritium inventory, dynamic performance, stability, and system control

  1. Anatomic relationship between left coronary artery and left atrium in patients undergoing atrial fibrillation ablation.

    Science.gov (United States)

    Anselmino, Matteo; Torri, Federica; Ferraris, Federico; Calò, Leonardo; Castagno, Davide; Gili, Sebastiano; Rovera, Chiara; Giustetto, Carla; Gaita, Fiorenzo

    2017-07-01

    Atrial fibrillation transcatheter ablation (TCA) is, within available atrial fibrillation rhythm control strategies, one of the most effective. To potentially improve ablation outcome in case of recurrent atrial fibrillation after a first procedure or in presence of structural myocardial disease, isolation of the pulmonary veins may be associated with extensive lesions within the left atrium. To avoid rare, but potentially life-threatening, complications, thorough knowledge and assessment of left atrium anatomy and its relation to structures in close proximity are, therefore, mandatory. Aim of the present study is to describe, by cardiac computed tomography, the anatomic relationship between aortic root, left coronary artery and left atrium in patients undergoing atrial fibrillation TCA. The cardiac computed tomography scan of 21 patients affected by atrial fibrillation was elaborated to segment left atrium, aortic root and left coronary artery from the surrounding structures and the following distances measured: left atrium and aortic root; left atrium roof and aortic root; left main coronary artery and left atrium; circumflex artery and left atrium appendage; and circumflex artery and mitral valve annulus. Above all, the median distance between left atrium and aortic root (1.9, 1.5-2.1 mm), and between circumflex artery and left atrium appendage ostium (3.0, 2.1-3.4 mm) were minimal (≤3 mm). None of measured distances significantly varied between patients presenting paroxysmal versus persistent atrial fibrillation. The anatomic relationship between left atrium and coronary arteries is extremely relevant when performing atrial fibrillation TCA by extensive lesions. Therefore, at least in the latter case, preablation imaging should be recommended to avoid rare, but potentially life-threatening, complications with the aim of an as well tolerated as possible procedure.

  2. One column method to prepare 11C-labelled methyl iodide

    International Nuclear Information System (INIS)

    Kovacs, Z.; Priboczki, E.

    1999-01-01

    A new method in which the [ 11 C]methyl iodide is prepared on one alumina column is presented. A high specific surface alumina column, previously impregnated with lithium aluminium hydride solution, was used for direct trapping from the target gas and reduction into radiocomplex. The complex was then reacted on this column with HI to form [ 11 C]methyl iodide. The use of one alumina column, instead of a freezing trap, reaction vessel and separate unit for iodination, simplifies the apparatus, shortens the synthesis time and is well suitable for automation. (K.A.)

  3. Modeling atrazine transport in soil columns with HYDRUS-1D

    Directory of Open Access Journals (Sweden)

    John Leju Celestino Ladu

    2011-09-01

    Full Text Available Both physical and chemical processes affect the fate and transport of herbicides. It is useful to simulate these processes with computer programs to predict solute movement. Simulations were run with HYDRUS-1D to identify the sorption and degradation parameters of atrazine through calibration from the breakthrough curves (BTCs. Data from undisturbed and disturbed soil column experiments were compared and analyzed using the dual-porosity model. The study results show that the values of dispersivity are slightly lower in disturbed columns, suggesting that the more heterogeneous the structure is, the higher the dispersivity. Sorption parameters also show slight variability, which is attributed to the differences in soil properties, experimental conditions and methods, or other ecological factors. For both of the columns, the degradation rates were similar. Potassium bromide was used as a conservative non-reactive tracer to characterize the water movement in columns. Atrazine BTCs exhibited significant tailing and asymmetry, indicating non-equilibrium sorption during solute transport. The dual-porosity model was verified to best fit the BTCs of the column experiments. Greater or lesser concentration of atrazine spreading to the bottom of the columns indicated risk of groundwater contamination. Overall, HYDRUS-1D successfully simulated the atrazine transport in soil columns.

  4. Cystic solitary fibrous tumor arising from the left occipital meninges: a case report

    Energy Technology Data Exchange (ETDEWEB)

    Oh, Bae Geun; Hwang, Yoon Joon; Cha, Soon Joo; Hur, Gham; Kim, Yong Hoon; Kim, Su Young; Seo, Jung Wook; Lee, Ji Young; Kim, Han Seung [Ilsan Paik Hospital, Inje University, School of Medicine, Goyang (Korea, Republic of)

    2007-02-15

    Solitary fibrous tumor (SFT) is a benign mesenchymal neoplasm of a spindle-cell origin, and it usually involves the pleura. It's occurrence in various organs of the body has recently been described. Meningeal SFT is very rare. Radiologically, it is a strongly enhancing solid mass and is undistinguishable from fibrous meningioma and hemangiopericytoma. Yet we report here on a case of SFT with massive cystic degeneration that arose from the meninges of the left occipital region.

  5. Microstructural asymmetry of the corticospinal tracts predicts right-left differences in circle drawing skill in right-handed adolescents

    DEFF Research Database (Denmark)

    Angstmann, Steffen; Madsen, Kathrine Skak; Skimminge, Arnold

    2016-01-01

    Most humans show a strong preference to use their right hand, but strong preference for the right hand does not necessarily imply a strong right-left asymmetry in manual proficiency (i.e., dexterity). Here we tested the hypothesis that intra-individual asymmetry of manual proficiency would...... be reflected in microstructural differences between the right and left corticospinal tract (CST) in a cohort of 52 right-handed typically-developing adolescents (11-16 years). Participants were asked to fluently draw superimposed circles with their right dominant and left non-dominant hand. Temporal regularity...... of circle drawing movements was assessed for each hand using a digitizing tablet. Although all participants were right-handed, there was substantial inter-individual variation regarding the relative right-hand advantage for fluent circle drawing. All subjects underwent whole-brain diffusion tensor imaging...

  6. Internet delivered question and answer column for patients with schizophrenia.

    Science.gov (United States)

    Maijala, Riikka; Anttila, Minna; Koivunen, Marita; Pitkänen, Anneli; Kuosmanen, Lauri; Välimäki, Maritta

    2015-01-01

    The purpose of this study was to describe the use of an Internet delivered question and answer column among patients with schizophrenia. The column was developed for research purposes. The study sample consisted of patients (N = 100) admitted to acute inpatient psychiatric care in two hospital districts. Descriptive data were collected from the column to which a nurse replied within 3 days and analysed using qualitative content analysis. The column had four to five questions weekly. The most common age of users was 18-24 years, and the gender distribution was almost equal. Column use was heaviest among students (44%) and least among unemployed people (19%). Out of 85 questions or comments sent to the column, 25 (29%) were related to program training and the remaining 60 (71%) were related to medication (31%), illness and tests (25%), other questions or comments (9%), daily life and coping with it (4%), and places to receive treatment (2%). An Internet delivered question and answer column can be included in the care of patients with schizophrenia. However, it requires a new type of basic and additional education in the field of mental health care in order for nurses to be able to provide nursing via the Internet forum.

  7. Left-Wing Extremism: The Current Threat

    Energy Technology Data Exchange (ETDEWEB)

    Karl A. Seger

    2001-04-30

    Left-wing extremism is ''alive and well'' both in the US and internationally. Although the current domestic terrorist threat within the U. S. is focused on right-wing extremists, left-wing extremists are also active and have several objectives. Leftist extremists also pose an espionage threat to U.S. interests. While the threat to the U.S. government from leftist extremists has decreased in the past decade, it has not disappeared. There are individuals and organizations within the U.S. who maintain the same ideology that resulted in the growth of left-wing terrorism in this country in the 1970s and 1980s. Some of the leaders from that era are still communicating from Cuba with their followers in the U.S., and new leaders and groups are emerging.

  8. Evaluation of Controller Tuning Methods Applied to Distillation Column Control

    DEFF Research Database (Denmark)

    Nielsen, Kim; W. Andersen, Henrik; Kümmel, Professor Mogens

    A frequency domain approach is used to compare the nominal performance and robustness of dual composition distillation column control tuned according to Ziegler-Nichols (ZN) and Biggest Log Modulus Tuning (BLT) for three binary distillation columns, WOBE, LUVI and TOFA. The scope of this is to ex......A frequency domain approach is used to compare the nominal performance and robustness of dual composition distillation column control tuned according to Ziegler-Nichols (ZN) and Biggest Log Modulus Tuning (BLT) for three binary distillation columns, WOBE, LUVI and TOFA. The scope...

  9. The coiled-coil domain containing protein CCDC40 is essential for motile cilia function and left-right axis formation

    DEFF Research Database (Denmark)

    Becker-Heck, Anita; Zohn, Irene E; Okabe, Noriko

    2011-01-01

    Primary ciliary dyskinesia (PCD) is a genetically heterogeneous autosomal recessive disorder characterized by recurrent infections of the respiratory tract associated with the abnormal function of motile cilia. Approximately half of individuals with PCD also have alterations in the left-right...... organization of their internal organ positioning, including situs inversus and situs ambiguous (Kartagener's syndrome). Here, we identify an uncharacterized coiled-coil domain containing a protein, CCDC40, essential for correct left-right patterning in mouse, zebrafish and human. In mouse and zebrafish, Ccdc40...

  10. Kansas Department of Transportation column expert : ultimate shear capacity of circular columns using the simplified modified compression field theory.

    Science.gov (United States)

    2015-09-01

    The importance of the analysis of circular columns to accurately predict their ultimate confined : capacity under shear-flexure-axial force interaction domain is recognized in light of the extreme load event : imposed by the current American Associat...

  11. Experimental evaluation of the prevention methods for the interface between masonry infill walls and concrete columns

    Directory of Open Access Journals (Sweden)

    A. P. Tramontin

    Full Text Available Cracks that form at the interfaces between masonry structures are common uncontrolled occurrences in buildings. Numerous methods have been proposed by the construction industry to address this problem. Cracks continuously form in the joints between concrete columns and masonry infill walls. In this study, the most common methods for preventing these types of cracks were evaluated in laboratory experiments. Column masonry models were constructed using different types of joints between concrete columns and masonry infill walls, such as steel bars and steel mesh. The efficiency of each type of joint method was evaluated by performing direct tensile tests (pullout tests on the models and monitoring the evolution of the crack opening in the joint between the column and wall, as a function of load applied to the model. The results from this study indicate that the model composed of "electrowelded wire mesh without steel angles" is the best model for controlling cracking in the joints between concrete columns and masonry infill walls.

  12. Chapter 2: Optical Properties of the Water Column

    Science.gov (United States)

    Kiefer, D. A.; Collins, D. J.

    1994-01-01

    In this chapter, and in chapter 29, the basic inter-relationship between the flux of radiant energy through the water column and the fixation of carbon by the phytoplankton in the ocean through processes of photosynthesis or primary production will be discussed.

  13. The annual cycle of plutonium in the water column of a warm, monomictic reservoir

    International Nuclear Information System (INIS)

    Pinder, J.E. III; Alberts, J.J.; Bowling, J.W.; Nelson, D.M.; Orlandini, K.A.

    1992-01-01

    An annual cycle occurs in the 239,240 Pu inventories of the water column of Pond B, an 87-ha warm monomictic reservoir on the US Department of Energy's Savannah River Site in Barnwell Co., South Carolina. The pond has elevated concentrations of 238 Pu and 239,240 Pu in sediments due to releases from former reactor operations and continues to receive additional Pu input from atmospheric deposition. For surface waters, the 239,240 Pu inventory increases following turnover in November to a maximum in March followed by a decline until later summer when minimum inventories occur. For deeper waters, the 239,240 Pu inventories increase rapidly following turnover and reach maximum values in March. The inventories in deeper waters remain large from March until turnover. Maximum inventories for the entire water column occur in March with minimum inventories at turnover in October and November. Turnover results in a redistribution of Pu across water depth but no measurable Pu loss from the water column. Ratios of 238 Pu: 239,240 Pu indicate that the cycle involves primarily Pu from sediment sources with little influence from atmospheric sources. Thus, the cycle represents net remobilization of 239,240 Pu from the sediments to the water column during the oxic, holomictic portion of the year followed by a net loss of Pu from the water column once stratification occurs. (author)

  14. REUSABILITY OF BOND ELUT CERTIFY COLUMNS FOR THE EXTRACTION OF DRUGS FROM PLASMA

    NARCIS (Netherlands)

    CHEN, XH; FRANKE, JP; WIJSBEEK, J; DEZEEUW, RA

    1993-01-01

    The reusability of Bond Elut Certify columns for the extraction of toxicologically relevant drugs from plasma has been evaluated. Pentobarbital, hexobarbital, mepivacaine, trimipramine and clonazepam were selected as test drugs to represent various classes of drugs. The columns were regenerated

  15. The modern mythology of the left-handedness of Alexander the Great.

    Science.gov (United States)

    McManus, I C

    2006-11-01

    The prevalent modern suggestion that Alexander the Great was left-handed probably derives from Michael Barsley's (1966) book, Left-handed man is a right-handed word, perhaps by mutation from as earlier story cited by Wile in 1934 from a 17th century Rabbirical exegesis, which said that Alexander discovered a country where all the inhabitants were left-handed. That itself may derive in part from the medieval Hebrew Book of Jossippon, which mentions Alexander talking of the superiority of the left hand and of how "kings stemming from the tribe of kings are left-handed".

  16. Microbial methane production in oxygenated water column of an oligotrophic lake

    Science.gov (United States)

    Grossart, Hans-Peter; Frindte, Katharina; Dziallas, Claudia; Eckert, Werner; Tang, Kam W.

    2011-01-01

    The prevailing paradigm in aquatic science is that microbial methanogenesis happens primarily in anoxic environments. Here, we used multiple complementary approaches to show that microbial methane production could and did occur in the well-oxygenated water column of an oligotrophic lake (Lake Stechlin, Germany). Oversaturation of methane was repeatedly recorded in the well-oxygenated upper 10 m of the water column, and the methane maxima coincided with oxygen oversaturation at 6 m. Laboratory incubations of unamended epilimnetic lake water and inoculations of photoautotrophs with a lake-enrichment culture both led to methane production even in the presence of oxygen, and the production was not affected by the addition of inorganic phosphate or methylated compounds. Methane production was also detected by in-lake incubations of lake water, and the highest production rate was 1.8–2.4 nM⋅h−1 at 6 m, which could explain 33–44% of the observed ambient methane accumulation in the same month. Temporal and spatial uncoupling between methanogenesis and methanotrophy was supported by field and laboratory measurements, which also helped explain the oversaturation of methane in the upper water column. Potentially methanogenic Archaea were detected in situ in the oxygenated, methane-rich epilimnion, and their attachment to photoautotrophs might allow for anaerobic growth and direct transfer of substrates for methane production. Specific PCR on mRNA of the methyl coenzyme M reductase A gene revealed active methanogenesis. Microbial methane production in oxygenated water represents a hitherto overlooked source of methane and can be important for carbon cycling in the aquatic environments and water to air methane flux. PMID:22089233

  17. Reliability of a four-column classification for tibial plateau fractures.

    Science.gov (United States)

    Martínez-Rondanelli, Alfredo; Escobar-González, Sara Sofía; Henao-Alzate, Alejandro; Martínez-Cano, Juan Pablo

    2017-09-01

    A four-column classification system offers a different way of evaluating tibial plateau fractures. The aim of this study is to compare the intra-observer and inter-observer reliability between four-column and classic classifications. This is a reliability study, which included patients presenting with tibial plateau fractures between January 2013 and September 2015 in a level-1 trauma centre. Four orthopaedic surgeons blindly classified each fracture according to four different classifications: AO, Schatzker, Duparc and four-column. Kappa, intra-observer and inter-observer concordance were calculated for the reliability analysis. Forty-nine patients were included. The mean age was 39 ± 14.2 years, with no gender predominance (men: 51%; women: 49%), and 67% of the fractures included at least one of the posterior columns. The intra-observer and inter-observer concordance were calculated for each classification: four-column (84%/79%), Schatzker (60%/71%), AO (50%/59%) and Duparc (48%/58%), with a statistically significant difference among them (p = 0.001/p = 0.003). Kappa coefficient for intr-aobserver and inter-observer evaluations: Schatzker 0.48/0.39, four-column 0.61/0.34, Duparc 0.37/0.23, and AO 0.34/0.11. The proposed four-column classification showed the highest intra and inter-observer agreement. When taking into account the agreement that occurs by chance, Schatzker classification showed the highest inter-observer kappa, but again the four-column had the highest intra-observer kappa value. The proposed classification is a more inclusive classification for the posteromedial and posterolateral fractures. We suggest, therefore, that it be used in addition to one of the classic classifications in order to better understand the fracture pattern, as it allows more attention to be paid to the posterior columns, it improves the surgical planning and allows the surgical approach to be chosen more accurately.

  18. Graph Modelling Approach: Application to a Distillation Column

    DEFF Research Database (Denmark)

    Hovelaque, V.; Commault, C.; Bahar, Mehrdad

    1997-01-01

    Introduction, structured systems and digraphs, distillation column model, generic input-output decoupling problem, generic disturbance rejection problem, concluding remarks.......Introduction, structured systems and digraphs, distillation column model, generic input-output decoupling problem, generic disturbance rejection problem, concluding remarks....

  19. Experimental and Numerical Study of FRP Encased Composite Concrete Columns

    Directory of Open Access Journals (Sweden)

    Mohsen Ishaghian

    2017-02-01

    Full Text Available A new type of composite column is presented and assessed through experimental testing and numerical modeling. The objective of this research is to investigate design options for a composite column without the use of ferrous materials. This is to avoid the current problem of deterioration of concrete due to expansion of rusting reinforcement members. Such a target can be achieved by replacing the steel reinforcement of concrete columns with pultruded I-shape glass FRP structural sections. The composite column utilizes a glass FRP tube that surrounds a pultruded I-section glass FRP, which is subsequently filled with concrete. The GFRP tube acts as a stay-in-place form in addition to providing confinement to the concrete. A total of four composite columns were tested under monotonic axial loading. The experimental ultimate capacity of each of the tested composite column was compared to the predicted numerical capacity using ANSYS program. The comparison showed that the predicted numerical values were in good agreement with the experimental ones.

  20. A Modelling Framework for Conventional and Heat Integrated Distillation Columns

    DEFF Research Database (Denmark)

    Bisgaard, Thomas; Huusom, Jakob Kjøbsted; Abildskov, Jens

    2013-01-01

    of hydrocarbons such as separations of equimolar mixtures of benzene/toluene or propane/propene described by simple models, a generic, modular, model framework is presented in this work. At present, the framework is able to describe a conventional distillation column, a mechanical vapor recompression column......Diabatic operation of distillation columns can lead to signicant reductions in energy utilization and operation cost compared to conventional (adiabatic) distillation columns, at an expense of an increased complexity of design and operation. The earliest diabatic distillation conguration dates back...... to the late 70s, and various dierent congurations have appeared since. However, at present, no full-scale diabatic distillation columns are currently operating in the industry. Current studies related to alternative distillation congurations report very dierent gures for potential energy savings which...

  1. Electric field strength in a silicon surface barrier detector with the presence of a dielectric plasma column

    International Nuclear Information System (INIS)

    Kanno, Ikuo

    1994-01-01

    The dynamic change of the electric field strength in a silicon surface barrier detector (SSBD) is studied. With the presence of a dielectric plasma column in the depletion layer of the SSBD, the electric field strength inside/outside the plasma column is suppressed/enhanced. As the length and the dielectric constant of the plasma column become shorter and smaller, the suppression and enhancement of the electric field strength become less. The electric field strength recovers the initial state, when the plasma column disappears. When the electrons and holes are inside/outside the dielectric plasma column, they have less/more electric potential than the one they have when there is no plasma column. During the movement of the electron/hole outside the plasma column to the positive/negative electrode, the enhanced electric field strength becomes smaller. Electron and hole pairs, which are the parts of the dielectric plasma column, arrive at positive and negative electrodes, having insufficient electric potential to induce the unit charge. This paper shows that the presence of a dielectric plasma column explains the main part of the residual defect in a SSBD. ((orig.))

  2. Choosing words: left hemisphere, right hemisphere, or both? Perspective on the lateralization of word retrieval

    Science.gov (United States)

    Ries, Stephanie K.; Dronkers, Nina F.; Knight, Robert T.

    2015-01-01

    Language is considered to be one of the most lateralized human brain functions. Left hemisphere dominance for language has been consistently confirmed in clinical and experimental settings and constitutes one of the main axioms of neurology and neuroscience. However, functional neuroimaging studies are finding that the right hemisphere also plays a role in diverse language functions. Critically, the right hemisphere may also compensate for the loss or degradation of language functions following extensive stroke-induced damage to the left hemisphere. Here, we review studies that focus on our ability to choose words as we speak. Although fluidly performed in individuals with intact language, this process is routinely compromised in aphasic patients. We suggest that parceling word retrieval into its sub-processes—lexical activation and lexical selection—and examining which of these can be compensated for after left hemisphere stroke can advance the understanding of the lateralization of word retrieval in speech production. In particular, the domain-general nature of the brain regions associated with each process may be a helpful indicator of the right hemisphere's propensity for compensation. PMID:26766393

  3. Studies on coal flotation in flotation column using statistical technique

    Energy Technology Data Exchange (ETDEWEB)

    M.S. Jena; S.K. Biswal; K.K. Rao; P.S.R. Reddy [Institute of Minerals & Materials Technology (IMMT), Orissa (India)

    2009-07-01

    Flotation of Indian high ash coking coal fines to obtain clean coal has been reported earlier by many authors. Here an attempt has been made to systematically analyse factors influencing the flotation process using statistical design of experiments technique. Studies carried out in a 100 mm diameter column using factorial design to establish weightage of factors such as feed rate, air rate and collector dosage indicated that all three parameters have equal influence on the flotation process. Subsequently RSM-CCD design was used to obtain best result and it is observed that 94% combustibles can be recovered with 82.5% weight recovery at 21.4% ash from a feed containing 31.3% ash content.

  4. Study of hydrodynamic and mass transfer parameters in pulsed sieve-plate columns

    International Nuclear Information System (INIS)

    Safdari, J.

    2001-01-01

    One of the most important liquid-liquid extractor in industry is pulsed column. The pulsed columns are generally classified into the following categories: 1-Pulsed perforated-plate column. 2- Pulsed packed column. The pulsed plate column is differential contactor with the application of mechanical energy and is used for a diverse range of processes. Probably its best known application has been in the nuclear fuel industry. The pulsed plate column consists of a cylindrical shell with settling zones at the top and the bottom of the column. The liquids are fed continuously to the column (flowing counter-currently) and are removed continuously from opposite ends of the column. In this work using a pilot pulsed plate column and two different chemical systems (toluene/acetone/water and n-butyl acetate/acetone/water) various experiments are carried out. In each experiment direction of mass transfer is from organic phase (dispersed phase) into aqueous phase (continuous phase) and the continuous phase is water. The main objects of this thesis are as follow: a- Investigation of effect of operating parameters on dispersed phase hold up, volumetric overall mass transfer coefficients based on dispersed and continuous phase, extraction efficiency, pressure drop of column and flooding velocities (maximum column capacities). Obtained results in this part show that if the calorimetric flow rate of aqueous phase or pulsation intensity increase, hold up, volumetric overall mass transfer coefficients based on both two phases and extraction efficiency will increase and flooding velocities will decrease. Also results show that if volumetric flow rate of organic phase increase, hold up, volumetric mass transfer coefficients based on both two phases and pressure drop will increase and extraction efficiency and flooding velocities will decrease. b- Investigation of effect of internal circulation inside drops in designing pulsed perforated-plate column

  5. Bilateral generic working memory circuit requires left-lateralized addition for verbal processing.

    Science.gov (United States)

    Ray, Manaan Kar; Mackay, Clare E; Harmer, Catherine J; Crow, Timothy J

    2008-06-01

    According to the Baddeley-Hitch model, phonological and visuospatial representations are separable components of working memory (WM) linked by a central executive. The traditional view that the separation reflects the relative contribution of the 2 hemispheres (verbal WM--left; spatial WM--right) has been challenged by the position that a common bilateral frontoparietal network subserves both domains. Here, we test the hypothesis that there is a generic WM circuit that recruits additional specialized regions for verbal and spatial processing. We designed a functional magnetic resonance imaging paradigm to elicit activation in the WM circuit for verbal and spatial information using identical stimuli and applied this in 33 healthy controls. We detected left-lateralized quantitative differences in the left frontal and temporal lobe for verbal > spatial WM but no areas of activation for spatial > verbal WM. We speculate that spatial WM is analogous to a "generic" bilateral frontoparietal WM circuit we inherited from our great ape ancestors that evolved, by recruitment of additional left-lateralized frontal and temporal regions, to accommodate language.

  6. Characterization of the efficiency of microbore liquid chromatography columns by van Deemter and kinetic plot analysis.

    Science.gov (United States)

    Hetzel, Terence; Loeker, Denise; Teutenberg, Thorsten; Schmidt, Torsten C

    2016-10-01

    The efficiency of miniaturized liquid chromatography columns with inner diameters between 200 and 300 μm has been investigated using a dedicated micro-liquid chromatography system. Fully porous, core-shell and monolithic commercially available stationary phases were compared applying van Deemter and kinetic plot analysis. The sub-2 μm fully porous as well as the 2.7 μm core-shell particle packed columns showed superior efficiency and similar values for the minimum reduced plate heights (2.56-2.69) before correction for extra-column contribution compared to normal-bore columns. Moreover, the influence of extra-column contribution was investigated to demonstrate the difference between apparent and intrinsic efficiency by replacing the column by a zero dead volume union to determine the band spreading caused by the system. It was demonstrated that 72% of the intrinsic efficiency could be reached. The results of the kinetic plot analysis indicate the superior performance of the sub-2 μm fully porous particle packed column for ultra-fast liquid chromatography. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  7. Ultrasonic testing device having an adjustable water column

    Science.gov (United States)

    Roach, Dennis P.; Neidigk, Stephen O.; Rackow, Kirk A.; Duvall, Randy L.

    2015-09-01

    An ultrasonic testing device having a variable fluid column height is disclosed. An operator is able to adjust the fluid column height in real time during an inspection to to produce optimum ultrasonic focus and separate extraneous, unwanted UT signals from those stemming from the area of interest.

  8. Structural Decoupling and Disturbance Rejection in a Distillation Column

    DEFF Research Database (Denmark)

    Bahar, Mehrdad; Jantzen, Jan; Commault, C.

    1996-01-01

    Introduction, distillation column model, input-output decoupling, disturbance rejection, concluding remarks, references.......Introduction, distillation column model, input-output decoupling, disturbance rejection, concluding remarks, references....

  9. Exhaust properties of centre-column-limited plasmas on MAST

    International Nuclear Information System (INIS)

    Maddison, G.P.; Akers, R.J.; Brickley, C.; Gryaznevich, M.P.; Lott, F.C.; Patel, A.; Sykes, A.; Turner, A.; Valovic, M.

    2007-01-01

    The lowest aspect ratio possible in a spherical tokamak is defined by limiting the plasma on its centre column, which might therefore maximize many physics benefits of this fusion approach. A key issue for such discharges is whether loads exhausted onto the small surface area of the column remain acceptable. A first series of centre-column-limited pulses has been examined on MAST using fast infra-red thermography to infer incident power densities as neutral-beam heating was scanned from 0 to 2.5 MW. Simple mapping shows that efflux distributions on the column armour are governed mostly by magnetic geometry, which moreover spreads them advantageously over almost the whole vertical length. Hence steady peak power densities between sawteeth remained low, -2 , comparable with the target strike-point value in a reference diverted plasma at lower power. Plasma purity and normalized thermal energy confinement through the centre-column-limited (CCL) series were also similar to properties of MAST diverted cases. A major bonus of CCL geometry is a propensity for exhaust to penetrate through its inner scrape-off layer connecting to the column into an expanding outer plume, which forms a 'natural divertor'. Effectiveness of this process may even increase with plasma heating, owing to rising Shafranov shift and/or toroidal rotation. A larger CCL device could potentially offer a simpler, more economic next-step design

  10. Basal cell carcinoma on the left cheek

    International Nuclear Information System (INIS)

    Jancar, B.

    2007-01-01

    A 91-year-old female patient was treated with irradiation for histologically confirmed basal cell carcinoma on the left cheek. The tumour, measuring 3 x 3 cm, with the depth of 2 cm, was extending up to the lower lid of the left eye. (author)

  11. Influence of Torsion Effect on the Mechanical Characteristics of Reinforced Concrete Column

    Science.gov (United States)

    Wang, Debin; Fan, Guoxi

    2017-11-01

    The purpose of this paper is to study the effect of torsional effect and loading rate on the flexural capacity of RC members. Based on the fiber model of finite element software ABAQUS, a model has been established with the consideration of the strain rate sensitivity of steel and concrete. The model is used to reflect the influence of the rotational component of ground motion by applying the initial angular displacement. The mechanical properties of RC columns under monotonic loads are simulated. The simulation results show that there has been a decrease in the carrying capacity and initial stiffness of RC columns for high initial torsion angle. With the increase of initial torsion angle, the influence of loading rate on RC columns gradually increases.

  12. Innovation of Iron Reinforcing Column of Partical From Frame of Light Steel

    Science.gov (United States)

    Ramadhan, M. R.; Faslih, A.; Umar, M. Z.

    2018-05-01

    Almost half of houses in Indonesia are using lightweight steel roof truss today. The phenomenon in the field is that lightweight steel roof truss can blend with mortar mixture. Thus this phenomenon is captured for later applied dynamically, creatively, and innovatively with new idioms such as reinforcement for columns. This research aims to investigate the comparison of the way of making and the price of the materials between the column material made of the light steel and the column material made of the iron reinforcement which is the most efficient. Type of research is qualitative with a comparative causal approach. This research is divided into several stages, namely; Literature study, column creation, and validation. This study concluds that the manufacture of column material from reinforcement is more efficient, than the lightweight steel column material. The reinforcement column material is more efficient because of the more effective way of making and the price of the working materials more economical than the lightweight steel column material. Lightweight steel columns can be used for public housing on condition made by experienced craftsmen to make the process faster, and the dimensions of lightweight steel can be scaled down to make it more economical.

  13. Losing the left side of the world: rightward shift in human spatial attention with sleep onset.

    Science.gov (United States)

    Bareham, Corinne A; Manly, Tom; Pustovaya, Olga V; Scott, Sophie K; Bekinschtein, Tristan A

    2014-05-28

    Unilateral brain damage can lead to a striking deficit in awareness of stimuli on one side of space called Spatial Neglect. Patient studies show that neglect of the left is markedly more persistent than of the right and that its severity increases under states of low alertness. There have been suggestions that this alertness-spatial awareness link may be detectable in the general population. Here, healthy human volunteers performed an auditory spatial localisation task whilst transitioning in and out of sleep. We show, using independent electroencephalographic measures, that normal drowsiness is linked with a remarkable unidirectional tendency to mislocate left-sided stimuli to the right. The effect may form a useful healthy model of neglect and help in understanding why leftward inattention is disproportionately persistent after brain injury. The results also cast light on marked changes in conscious experience before full sleep onset.

  14. Preinjector for Linac 1, inside the Faraday cage

    CERN Multimedia

    1974-01-01

    For a description of the Linac 1 preinjector, please see first 7403070X. Here, the view is towards the upper level of the Faraday cage. Far to the right, a technician is peering through the service door. The huge box-shaped cubicle is the electronics platform, at 520 kV potential during operation. The "bull eye" at the left back sits at the top end of the accelerating column (see 7403081X) and houses the ion source with its electronics (see 7403083X). The SAMES generator, providing the 520 kV HV (7403074) sits on the floor and is not visible here.

  15. Fiber-based monolithic columns for liquid chromatography.

    Science.gov (United States)

    Ladisch, Michael; Zhang, Leyu

    2016-10-01

    Fiber-based monoliths for use in liquid chromatographic separations are defined by columns packed with aligned fibers, woven matrices, or contiguous fiber structures capable of achieving rapid separations of proteins, macromolecules, and low molecular weight components. A common denominator and motivating driver for this approach, first initiated 25 years ago, was reducing the cost of bioseparations in a manner that also reduced residence time of retained components while achieving a high ratio of mass to momentum transfer. This type of medium, when packed into a liquid chromatography column, minimized the fraction of stagnant liquid and resulted in a constant plate height for non-adsorbing species. The uncoupling of dispersion from eluent flow rate enabled the surface chemistry of the stationary phase to be considered separately from fluid transport phenomena and pointed to new ways to apply chemistry for the engineering of rapid bioseparations. This paper addresses developments and current research on fiber-based monoliths and explains how the various forms of this type of chromatographic stationary phase have potential to provide new tools for analytical and preparative scale separations. The different stationary phases are discussed, and a model that captures the observed constant plate height as a function of mobile phase velocity is reviewed. Methods that enable hydrodynamically stable fiber columns to be packed and operated over a range of mobile phase flow rates, together with the development of new fiber chemistries, are shown to provide columns that extend the versatility of liquid chromatography using monoliths, particularly at the preparative scale. Graphical Abstract Schematic representation of a sample mixture being separated by a rolled-stationary phase column, resulting separated peaks shown in the chromatogram.

  16. Searching for optimal integer solutions to set partitioning problems using column generation

    OpenAIRE

    Bredström, David; Jörnsten, Kurt; Rönnqvist, Mikael

    2007-01-01

    We describe a new approach to produce integer feasible columns to a set partitioning problem directly in solving the linear programming (LP) relaxation using column generation. Traditionally, column generation is aimed to solve the LP relaxation as quick as possible without any concern of the integer properties of the columns formed. In our approach we aim to generate the columns forming the optimal integer solution while simultaneously solving the LP relaxation. By this we can re...

  17. Influence of Connection Placement to the Behavior of Precast Concrete Exterior Beam-Column Joint

    OpenAIRE

    Elly Tjahjono; Heru Purnomo

    2010-01-01

    This paper presents an experimental study on the influence of connection placement to the behaviour of exterior beamcolumn joint of precast concrete structure under semi cyclic loading. Four half-scale beam-column specimens were investigated. Three beam-columns were jointed through connection that are placed in beam-column joint region and the forth is connected at the plastic hinge potensial region of the beam. Crack patterns, strength, stiffness and ductility of the test specimens have been...

  18. On the Relationship between Right- brain and Left- brain Dominance and Reading Comprehension Test Performance of Iranian EFL Learners

    Directory of Open Access Journals (Sweden)

    Hassan Soleimani

    2012-05-01

    Full Text Available A tremendous amount of works have been conducted by psycholinguistics to identify hemisphere processing during second/ foreign language learning, or in other words to investigate the role of the brain hemisphere dominance in language performance of learners. Most of these researches have focused on single words and word pairs (e.g., Anaki et al., 1998; Arzouan et. al., 2007; Faust & Mahal, 2007 or simple sentences (Rapp et al., 2007; Kacinik & Chiarello, 2007, and it has been discovered that there is an advantage of right hemisphere for metaphors and an
    advantage of left hemisphere for literal text. But the present research was designed to study Iranian EFL learners' performance in different reading tasks, so there could be differences between the consequences of the former research and the results of the present study due to the context. Here left-brain and right-brain dominance was investigated in 60 individuals (20 right-handed and 10 left-handed male, 20 right-handed and 10 left-handed female via the Edinburg Handedness Questionnaire (EHQ. The research results suggested that the right-handed learners who are supposed to be left-brain outperformed the left-handed ones; and regarding participant's gender, male learners outperformed female learners on reading comprehension test tasks.

  19. Input-Output Decoupling of a Distillation Column LV-Configuration

    DEFF Research Database (Denmark)

    Yazdi, H.; Jørgensen, Sten Bay; Bahar (fratrådt), Mehrdad

    1996-01-01

    Introduction, digraph approach, distillation column, digraph analysis, solution analysis, discussion and conclusion, references.......Introduction, digraph approach, distillation column, digraph analysis, solution analysis, discussion and conclusion, references....

  20. Perceptual expertise: can sensorimotor experience change holistic processing and left-side bias?

    Science.gov (United States)

    Tso, Ricky Van-yip; Au, Terry Kit-fong; Hsiao, Janet Hui-wen

    2014-09-01

    Holistic processing and left-side bias are both behavioral markers of expert face recognition. By contrast, expert recognition of characters in Chinese orthography involves left-side bias but reduced holistic processing, although faces and Chinese characters share many visual properties. Here, we examined whether this reduction in holistic processing of Chinese characters can be better explained by writing experience than by reading experience. Compared with Chinese nonreaders, Chinese readers who had limited writing experience showed increased holistic processing, whereas Chinese readers who could write characters fluently showed reduced holistic processing. This result suggests that writing and sensorimotor experience can modulate holistic-processing effects and that the reduced holistic processing observed in expert Chinese readers may depend mostly on writing experience. However, both expert writers and writers with limited experience showed similarly stronger left-side bias than novices did in processing mirror-symmetric Chinese characters; left-side bias may therefore be a robust expertise marker for object recognition that is uninfluenced by sensorimotor experience. © The Author(s) 2014.

  1. Plecospondylic spinal column in the eel Anguilla anguilla

    NARCIS (Netherlands)

    Stolk, A.

    1956-01-01

    Several cases of deformities in the spinal column were described in fishes, viz. lordosis in the bitterling Rhodeus amarus) by ROTH (1922), in the minnow (Phoxinus phoxinus) by ROTH (1922), in the pike (Esox lucius) by ROTH (1922) and PLEHN (1924); kyphosis in the toothcarps (Cyprinodontidae) by

  2. 40 CFR Table 25 to Subpart G of... - Effective Column Diameter (Fc)

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 9 2010-07-01 2010-07-01 false Effective Column Diameter (Fc) 25 Table..., Table 25 Table 25 to Subpart G of Part 63—Effective Column Diameter (Fc) Column type Fc (feet) 9-inch by 7-inch built-up columns 1.1 8-inch-diameter pipe columns 0.7 No construction details known 1.0 ...

  3. The effect of gas release on column separator

    NARCIS (Netherlands)

    Kranenburg, C.

    1974-01-01

    A mathematical model has been considered in which the influence of gas release on transient cavitating flow and column separation in pipel ines is taken into account. A rei iable numerical method has been developed for the computation of the wave propagation and cavitation phenomena following pump

  4. Identification of column edges of DNA fragments by using K-means clustering and mean algorithm on lane histograms of DNA agarose gel electrophoresis images

    Science.gov (United States)

    Turan, Muhammed K.; Sehirli, Eftal; Elen, Abdullah; Karas, Ismail R.

    2015-07-01

    Gel electrophoresis (GE) is one of the most used method to separate DNA, RNA, protein molecules according to size, weight and quantity parameters in many areas such as genetics, molecular biology, biochemistry, microbiology. The main way to separate each molecule is to find borders of each molecule fragment. This paper presents a software application that show columns edges of DNA fragments in 3 steps. In the first step the application obtains lane histograms of agarose gel electrophoresis images by doing projection based on x-axis. In the second step, it utilizes k-means clustering algorithm to classify point values of lane histogram such as left side values, right side values and undesired values. In the third step, column edges of DNA fragments is shown by using mean algorithm and mathematical processes to separate DNA fragments from the background in a fully automated way. In addition to this, the application presents locations of DNA fragments and how many DNA fragments exist on images captured by a scientific camera.

  5. Sustainable materials used as stone column filler: A short review

    Science.gov (United States)

    Zukri, Azhani; Nazir, Ramli

    2018-04-01

    Stone columns (also known as granular piles) are one of the methods for soft soil stabilization and typically used to increase bearing capacity and stability of slope.; Apart from decreasing the compressibility of loose and fine graded soils, it also accelerates the consolidation effect by improving the drainage path for pore water pressure dissipation and reduces the liquefaction potential of soils during earthquake event. Stone columns are probably the most “natural” ground treatment method or foundation system in existence to date. The benefit of stone columns is owing to the partial replacement of compressible soil by more competent materials such as stone aggregate, sand and other granular materials. These substitutes also act as reinforcement material, hence increasing overall strength and stiffness of the soft soil. Nowadays, a number of research has been conducted on the behaviour and performance of stone columns with various materials utilized as column filler replacing the normal aggregate. This paper will review extensively on previously conducted research on some of the materials used as stone column backfill materials, its suitability and the effectiveness as a substitute for regular aggregates in soft soil improvement works.

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

    Science.gov (United States)

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

    2015-01-01

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

  7. Reorganization of syntactic processing following left-hemisphere brain damage: does right-hemisphere activity preserve function?

    OpenAIRE

    Tyler, Lorraine K.; Wright, Paul; Randall, Billi; Marslen-Wilson, William D.; Stamatakis, Emmanuel A.

    2010-01-01

    The extent to which the human brain shows evidence of functional plasticity across the lifespan has been addressed in the context of pathological brain changes and, more recently, of the changes that take place during healthy ageing. Here we examine the potential for plasticity by asking whether a strongly left-lateralized system can successfully reorganize to the right-hemisphere following left-hemisphere brain damage. To do this, we focus on syntax, a key linguistic function considered to b...

  8. Comparison of twin-cell centrifugal partition chromatographic columns with different cell volume.

    Science.gov (United States)

    Goll, Johannes; Audo, Gregoire; Minceva, Mirjana

    2015-08-07

    Two twin-cell centrifugal partition chromatographic columns (SCPC 250 and SCPE-250-BIO, Armen Instrument, France) with the same column volume but different cell size and number were compared in terms of stationary phase retention and column efficiency. The columns were tested with two types of solvent systems: a commonly used organic solvent based biphasic system from the ARIZONA solvent system family and a polymer/salt based aqueous two phase system (ATPS). The efficiency of the columns was evaluated by pulse injection experiments of two benzenediols (pyrocatechol and hydroquinone) in the case of the ARIZONA system and a protein mixture (myoglobin and lysozyme) in the case of the ATPS. As result of high stationary phase retention, the column with the lower number of larger twin-cells (SCPE-250-BIO) is suitable for protein separations using ATPS. On the other hand, due to higher column efficiency, the column with the greater number of smaller cells (SCPC 250) is superior for batch elution separations performed with standard liquid-liquid chromatography organic solvent based biphasic systems. Copyright © 2015 Elsevier B.V. All rights reserved.

  9. The new left and democracy in Latin America

    Directory of Open Access Journals (Sweden)

    Francisco Panizza

    2009-05-01

    Full Text Available Without embarking on a theoretical debate over the meaning of the term, it is obvious that the left is on the rise in Latin America. However, we should not ignore the fact that the coming to power of left-wing and centre-left parties and movements presents a certain amount of paradoxes and questions. One of the most important of the many paradoxes is the fact that, in spite of the leftwards electoral shift in the region, there is no evidence that the electorate of Latin America has moved to the left in a significant manner. As for the questions, these concern the connection between left-wing governments and democracy, and especially the future challenges that these governments must face to preserve and develop democracy. In an attempt to unravel the paradox and answer these questions, this article examines the roots, contexts and political challenges of left-wing governments in Latin America. To this end, the author analyses a number of issues, such as the tensions between different logics of political representation and their implications for democracy, in addition to discussing the conditions under which the tensions between the different logics of political representation can contribute (or not to the developing of democracy in the region.

  10. Second dimension column ensemble pressure tuning in comprehensive two-dimensional gas chromatography.

    Science.gov (United States)

    Sharif, Khan M; Kulsing, Chadin; Junior, Ademario I da Silva; Marriott, Philip J

    2018-02-09

    A pressure tunable (PT) coupled column ensemble has been implemented for the second dimension ( 2 D) separation in comprehensive two dimensional gas chromatography (GC×PTGC). This process requires two columns to be connected by a pressure junction, as a replacement for a single narrow bore, short column in 2 D. Various 2 D 1 and 2 D 2 columns may be selected to provide complementary selectivity (polarity) compared to the 1 D column. The tunable residence time arising from differential pressure drop in each 2 D column results in a tunable fractional contribution of each column in the 2 D separation. A sample mixture comprising different chemical classes, including alkanes and alcohols, is used to identify the feasibility and extent of selectivity tuning possible in GC×PTGC. The column length is also varied due to the imposed challenge of wraparound in the PT coupled column system as pressures are adjusted in the 2 D separation. Different experimental parameters, stationary phase materials and column lengths have been applied to investigate and understand the separation behaviour of the 2 D PT coupled column GC×GC system. Results are discussed considering analyte retention time, peak width, linear velocity and the contribution of each 2 D column. A specific and unexpected example of GC×GC separation was demonstrated where the peak positions of polar and apolar compounds could almost swap their 2 D retention position by application of PT. Kerosene was analysed as an example of complex sample analysis by GC×PTGC system. This process is shown to be a practical approach for altering different stationary phase selectivities in a single 2 D arrangement in GC×GC. Copyright © 2017 Elsevier B.V. All rights reserved.

  11. The Effect of Column and Eluent Fluorination on the Retention and Separation of non-Fluorinated Amino Acids and Proteins by HPLC

    Science.gov (United States)

    Joyner, Katherine; Wang, Weizhen; Yu, Yihua Bruce

    2011-01-01

    The effect of column and eluent fluorination on the retention and separation of non-fluorinated amino acids and proteins in HPLC is investigated. A side-by-side comparison of fluorocarbon column and eluents (F-column and F-eluents) with their hydrocarbon counterparts (H-column and H-eluents) in the separation of a group of 33 analytes, including 30 amino acids and 3 proteins, is conducted. The H-column and the F-column contain the n-C8H17 group and n-C8F17 group, respectively, in their stationary phases. The H-eluents include ethanol (EtOH) and isopropanol (ISP) while the F-eluents include trifluoroethanol (TFE) and hexafluorosopropanol (HFIP). The 2 columns and 4 eluents generated 8 (column, eluent) pairs that produce 264 retention time data points for the 33 analytes. A statistical analysis of the retention time data reveals that although the H-column is better than the F-column in analyte separation and H-eluents are better than F-eluents in analyte retention, the more critical factor is the proper pairing of column with eluent. Among the conditions explored in this project, optimal retention and separation is achieved when the fluorocarbon column is paired with ethanol, even though TFE is the most polar one among the 4 eluents. This result shows fluorocarbon columns have much potential in chromatographic analysis and separation of non-fluorinated amino acids and proteins. PMID:21318121

  12. STUDY ON THE BEHAVIOUR OF PRECAST BEAM COLUMN JOINT USING STEEL PLATE CONNECTION (JPSP)

    OpenAIRE

    Parung, H.

    2012-01-01

    Joint beam column connection is the most critical part for a structure subjected to earthquake loading. This part should be designed such that any possible failure can be prevented. For a cast in situ structure, any failure in this joint can be prevented if all requirements in the design code are obeyed. For pre-cast construction, structural failure usually occurs at the beam-column connection. The research aimed at studying the strength of precast beam-column joint using steel plate as conne...

  13. MEANING-MAKING OF HEDGES IN THE GOSSIP COLUMN OF THE JAKARTA POST

    Directory of Open Access Journals (Sweden)

    Uswatun Hasanah

    2016-01-01

    Full Text Available The present study investigates the use of hedges (vague language as the meaning-making practice in the gossip column of the Jakarta Post. The daily newspaper is chosen due to pragmatic purposes, accessibility, and its national coverage. Adapting the framework of Lakoff (1973, Holmes (1990 and Hyland (1996a-b, this study focuses on the hedges’ functions and meanings in a gossip column (informal context, apart from an academic discourse (formal context in which hedges are frequently discussed. This possibly leads to the diverse functions and meanings of the hedges’ occurrences within the discourse: through the employment of ‘epistemic modal’ (the expression of uncertainty and ‘affective’ (the expression of solidarity function. Further, the mostly-found hedges are the epistemic modal ‘about’ (five times and the affective modal ‘think’ (four times from six hedge categories. Eventually, it is also revealed that hedges used in the gossip column are to enhance the self-image and trend-setting identity of the celebrities, who indeed are involved in the discourse.

  14. Graphite oxidation and structural strength of graphite support column in VHTR

    International Nuclear Information System (INIS)

    Park, Byung Ha; No, Hee Cheno; Kim, Eung Soo; Oh, Chang H.

    2009-01-01

    The air-ingress event by a large pipe break is an important accident considered in design of very high-temperature gas-cooled reactors (VHTR). Core-collapse prediction is a main safety issue. Structural failure model are technically required. The objective of this study is to develop structural failure model for the supporting graphite material in the lower plenum of the GT-MHR (gas-turbine-modular high temperature reactor). Graphite support column is important for VHTR structural integrity. Graphite support columns are under the axial load. Critical strength of graphite column is related to slenderness ratio and bulk density. Through compression tests for fresh and oxidized graphite columns we show that compressive strength of IG-110 was 79.46 MPa. And, the buckling strength of IG-110 column was expressed by the empirical formula: σ 0 =σ straight-line - C L/r, σ straight-line =91.31 MPa, C=1.01. The results of uniform and non-uniform oxidation tests show that the strength degradation of oxidized graphite column is expressed in the following non-dimensional form: σ/σ 0 =exp(-kd), k=0.111. Also, from the results of the uniform oxidation test with a complicated-shape column, we found out that the above non-dimensional equation obtained from the uniform oxidation test is applicable to a uniform oxidation case with a complicated-shape column. (author)

  15. Temperature-based on-column solute focusing in capillary liquid chromatography reduces peak broadening from precolumn dispersion and volume overload when used alone or with solvent-based focusing

    Science.gov (United States)

    Groskreutz, Stephen R.; Horner, Anthony R.; Weber, Stephen G.

    2015-01-01

    On-column focusing is essential for satisfactory performance using capillary scale columns. On-column focusing results from generating transient conditions at the head of the column that lead to high solute retention. Solvent-based on-column focusing is a well-known approach to achieve this. Temperature-assisted on-column focusing (TASF) can also be effective. TASF improves focusing by cooling a short segment of the column inlet to a temperature that is lower than the column temperature during the injection and then rapidly heating the focusing segment to the match the column temperature. A troublesome feature of an earlier implementation of TASF was the need to leave the capillary column unpacked in that portion of the column inside the fitting connecting it to the injection valve. We have overcome that problem in this work by packing the head of the column with solid silica spheres. In addition, technical improvements to the TASF instrumentation include: selection of a more powerful thermo-electric cooler to create faster temperature changes and electronic control for easy incorporation into conventional capillary instruments. Used in conjunction with solvent-based focusing and with isocratic elution, volumes of paraben samples (esters of p-hydroxybenzoic acid) up to 4.5-times the column liquid volume can be injected without significant bandspreading due to volume overload. Interestingly, the shapes of the peaks from the lowest volume injections that we can make, 30 nL, are improved when using TASF. TASF is very effective at reducing the detrimental effects of precolumn dispersion using isocratic elution. Finally, we show that TASF can be used to focus the neuropeptide galanin in a sample solvent with elution strength stronger than the mobile phase. Here, the stronger solvent is necessitated by the need to prevent peptide adsorption prior to and during analysis. PMID:26091787

  16. PERFORMANCE OF A PACKED LIQUID-LIQUID EXTRACTION COLUMN

    Directory of Open Access Journals (Sweden)

    İ. Metin HASDEMİR

    1999-03-01

    Full Text Available The influence of feed ratios ((LE/LR on the performance of a packed liquid-liquid extraction column, with a diameter of 5.86 cm and a column height of 132 cm was investigated. The column is made of borosilicate glas