Open-tubular capillary electrochromatographic determination of ten sulfonamides in tap water and milk by a metal-organic framework-coated capillary column.

PubMed

Wang, Xuan; Ye, Nengsheng; Hu, Xiaoyu; Liu, Qingye; Li, Jian; Peng, Lin; Ma, Xiaotong

2018-05-25

In this study, a metal-organic framework (MOF), [Mn(cam)(bpy)], was synthesized and characterized by thermogravimetric analysis, scanning electron microscopy, and Fourier transform infrared spectrometry. An open-tubular capillary column was fabricated from [Mn(cam)(bpy)] via the amide coupling method. Ten types of sulfonamides were separated through the fabricated capillary column, which showed a good limits of detection (< 0.07 μg·mL -1 ) and a linear ranges (1-100 μg·mL -1 or 5-100 μg·mL -1 ) with a high correlation coefficients (R 2 > 0.9987). The intra-day, inter-day and column-to-column relative standard deviations (RSDs) in the migration times ranged from 0.44% to 4.87%, and the peak area RSDs ranged from 0.80% to 7.28%. The developed capillary electrochromatography method can be successfully utilized for the determination of sulfonamides in tap water and milk samples. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

Effect of strong-column weak-beam design provision on the seismic fragility of RC frame buildings

NASA Astrophysics Data System (ADS)

Surana, Mitesh; Singh, Yogendra; Lang, Dominik H.

2018-04-01

Incremental dynamic analyses are conducted for a suite of low- and mid-rise reinforced-concrete special moment-resisting frame buildings. Buildings non-conforming and conforming to the strong-column weak-beam (SCWB) design criterion are considered. These buildings are designed for the two most severe seismic zones in India (i.e., zone IV and zone V) following the provisions of Indian Standards. It is observed that buildings non-conforming to the SCWB design criterion lead to an undesirable column failure collapse mechanism. Although yielding of columns cannot be avoided, even for buildings conforming to a SCWB ratio of 1.4, the observed collapse mechanism changes to a beam failure mechanism. This change in collapse mechanism leads to a significant increase in the building's global ductility capacity, and thereby in collapse capacity. The fragility analysis study of the considered buildings suggests that considering the SCWB design criterion leads to a significant reduction in collapse probability, particularly in the case of mid-rise buildings.

Characteristics of Tables for Disseminating Biobehavioral Results.

PubMed

Schneider, Barbara St Pierre; Nagelhout, Ed; Feng, Du

2018-01-01

To report the complexity and richness of study variables within biological nursing research, authors often use tables; however, the ease with which consumers understand, synthesize, evaluate, and build upon findings depends partly upon table design. To assess and compare table characteristics within research and review articles published in Biological Research for Nursing and Nursing Research. A total of 10 elements in tables from 48 biobehavioral or biological research or review articles were analyzed. To test six hypotheses, a two-level hierarchical linear model was used for each of the continuous table elements, and a two-level hierarchical generalized linear model was used for each of the categorical table elements. Additionally, the inclusion of probability values in statistical tables was examined. The mean number of tables per article was 3. Tables in research articles were more likely to contain quantitative content, while tables in review articles were more likely to contain both quantitative and qualitative content. Tables in research articles had a greater number of rows, columns, and column-heading levels than tables in review articles. More than one half of statistical tables in research articles had a separate probability column or had probability values within the table, whereas approximately one fourth had probability notes. Authors and journal editorial staff may be generating tables that better depict biobehavioral content than those identified in specific style guidelines. However, authors and journal editorial staff may want to consider table design in terms of audience, including alternative visual displays.

Directional Characteristics of Inner Shelf Internal Tides

DTIC Science & Technology

2007-06-01

Figure 18. YD 202-206 Current vector plot of significant events. Significant events include internal tidal bores, solibores, and solitons . The upper...Events (Bores, Solibores, and Solitons ): Upper column leading-edge cross-shore current velocity and cross-shore wind regression. The small ellipse...Significant Events (Bores, Solibores, and Solitons ): Upper column leading-edge along-shore current velocity and along-shore wind regression. The small

Study of scattering cross section of a plasma column using Green's function volume integral equation method

NASA Astrophysics Data System (ADS)

Soltanmoradi, Elmira; Shokri, Babak

2017-05-01

In this article, the electromagnetic wave scattering from plasma columns with inhomogeneous electron density distribution is studied by the Green's function volume integral equation method. Due to the ready production of such plasmas in the laboratories and their practical application in various technological fields, this study tries to find the effects of plasma parameters such as the electron density, radius, and pressure on the scattering cross-section of a plasma column. Moreover, the incident wave frequency influence of the scattering pattern is demonstrated. Furthermore, the scattering cross-section of a plasma column with an inhomogeneous collision frequency profile is calculated and the effect of this inhomogeneity is discussed first in this article. These results are especially used to determine the appropriate conditions for radar cross-section reduction purposes. It is shown that the radar cross-section of a plasma column reduces more for a larger collision frequency, for a relatively lower plasma frequency, and also for a smaller radius. Furthermore, it is found that the effect of the electron density on the scattering cross-section is more obvious in comparison with the effect of other plasma parameters. Also, the plasma column with homogenous collision frequency can be used as a better shielding in contrast to its inhomogeneous counterpart.

The Daniel K. Inouye College of Pharmacy Scripts

PubMed Central

2015-01-01

The Daniel K. Inouye College of Pharmacy is the newest professional school to be established in the State of Hawai‘i. The College is based at the University of Hawai‘i at Hilo, but faculty and students are located and practice on every major island. The mission of the College is to serve the entire Pacific Region. Having reached a respectable level of maturity over the past few years, we are now pleased to announce a partnership that has been established with the Hawai‘i Journal of Medicine & Public Health. With Dr. Carolyn Ma serving as column editor and coordinator, our main objective is for faculty and affiliates of the College to provide communications of contemporary interest in the field of professional pharmacy. Since academic pharmacy is new to the State, this inaugural article (Part 1) describes a brief history of the profession leading up to the founding of the Daniel K. Inouye College of Pharmacy. An article describing the mission, vision, and infrastructure of the College, as well as some objectives and accomplishments will follow this inaugural column. The pharmacist is an integral member of the health care team with unique expertise in pharmaceutical care. The topics we present should be of broad interest to the readership of this journal but, additionally, any suggestions for specialized topics in our realm of expertise are welcome. PMID:25628981

The Daniel K. Inouye College of Pharmacy scripts: Academic pharmacy strikes Hawai'i (part 1).

PubMed

Pezzuto, John M; Pezzuto, Mimi F

2015-01-01

The Daniel K. Inouye College of Pharmacy is the newest professional school to be established in the State of Hawai'i. The College is based at the University of Hawai'i at Hilo, but faculty and students are located and practice on every major island. The mission of the College is to serve the entire Pacific Region. Having reached a respectable level of maturity over the past few years, we are now pleased to announce a partnership that has been established with the Hawai'i Journal of Medicine & Public Health. With Dr. Carolyn Ma serving as column editor and coordinator, our main objective is for faculty and affiliates of the College to provide communications of contemporary interest in the field of professional pharmacy. Since academic pharmacy is new to the State, this inaugural article (Part 1) describes a brief history of the profession leading up to the founding of the Daniel K. Inouye College of Pharmacy. An article describing the mission, vision, and infrastructure of the College, as well as some objectives and accomplishments will follow this inaugural column. The pharmacist is an integral member of the health care team with unique expertise in pharmaceutical care. The topics we present should be of broad interest to the readership of this journal but, additionally, any suggestions for specialized topics in our realm of expertise are welcome.

Recent Progress in Monolithic Silica Columns for High-Speed and High-Selectivity Separations.

PubMed

Ikegami, Tohru; Tanaka, Nobuo

2016-06-12

Monolithic silica columns have greater (through-pore size)/(skeleton size) ratios than particulate columns and fixed support structures in a column for chemical modification, resulting in high-efficiency columns and stationary phases. This review looks at how the size range of monolithic silica columns has been expanded, how high-efficiency monolithic silica columns have been realized, and how various methods of silica surface functionalization, leading to selective stationary phases, have been developed on monolithic silica supports, and provides information on the current status of these columns. Also discussed are the practical aspects of monolithic silica columns, including how their versatility can be improved by the preparation of small-sized structural features (sub-micron) and columns (1 mm ID or smaller) and by optimizing reaction conditions for in situ chemical modification with various restrictions, with an emphasis on recent research results for both topics.

Graphene oxide sheets immobilized polystyrene for column preconcentration and sensitive determination of lead by flame atomic absorption spectrometry.

PubMed

Islam, Aminul; Ahmad, Hilal; Zaidi, Noushi; Kumar, Suneel

2014-08-13

A novel solid-phase extractant was synthesized by coupling graphene oxide (GO) on chloromethylated polystyrene through an ethylenediamine spacer unit to develop a column method for the preconcentration/separation of lead prior to its determination by flame atomic absorption spectrometry. It was characterized by Fourier transform infrared spectroscopy, far-infrared spectroscopy, thermogravimetric analysis/differential thermal analysis, scanning electron microscopy, energy-dispersive spectrometry, and transmission electron microscopy. The abundant oxygen-containing surface functional groups form a strong complex with lead, resulting in higher sorption capacity (227.92 mg g(-1)) than other nanosorbents used for sorption studies of the column method. Using the column procedure here is an alternative to the direct use of GO, which restricts irreversible aggregation of GO and its escape into the ecosystem, making it an environmentally sustainable method. The column method was optimized by varying experimental variables such as pH, flow rate for sorption/desorption, and elution condition and was observed to exhibit a high preconcentration factor (400) with a low preconcentration limit (2.5 ppb) and a high degree of tolerance for matrix ions. The accuracy of the proposed method was verified by determining the Pb content in the standard reference materials and by recovery experiments. The method showed good precision with a relative standard deviation <5%. The proposed method was successfully applied for the determination of lead in tap water, electroplating wastewater, river water, and food samples after preconcentration.

Multi-metals column adsorption of lead(II), cadmium(II) and manganese(II) onto natural bentonite clay.

PubMed

Alexander, Jock Asanja; Surajudeen, Abdulsalam; Aliyu, El-Nafaty Usman; Omeiza, Aroke Umar; Zaini, Muhammad Abbas Ahmad

2017-10-01

The present work was aimed at evaluating the multi-metals column adsorption of lead(II), cadmium(II) and manganese(II) ions onto natural bentonite. The bentonite clay adsorbent was characterized for physical and chemical properties using X-ray diffraction, X-ray fluorescence, Brunauer-Emmett-Teller surface area and cation exchange capacity. The column performance was evaluated using adsorbent bed height of 5.0 cm, with varying influent concentrations (10 mg/L and 50 mg/L) and flow rates (1.4 mL/min and 2.4 mL/min). The result shows that the breakthrough time for all metal ions ranged from 50 to 480 minutes. The maximum adsorption capacity was obtained at initial concentration of 10 mg/L and flow rate of 1.4 mL/min, with 2.22 mg/g of lead(II), 1.71 mg/g of cadmium(II) and 0.37 mg/g of manganese(II). The order of metal ions removal by natural bentonite is lead(II) > cadmium(II) > manganese(II). The sorption performance and the dynamic behaviour of the column were predicted using Adams-Bohart, Thomas, and Yoon-Nelson models. The linear regression analysis demonstrated that the Thomas and Yoon-Nelson models fitted well with the column adsorption data for all metal ions. The natural bentonite was effective for the treatment of wastewater laden with multi-metals, and the process parameters obtained from this work can be used at the industrial scale.

Columns in Clay

ERIC Educational Resources Information Center

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…

Ranking of predictor variables based on effect size criterion provides an accurate means of automatically classifying opinion column articles

NASA Astrophysics Data System (ADS)

Legara, Erika Fille; Monterola, Christopher; Abundo, Cheryl

2011-01-01

We demonstrate an accurate procedure based on linear discriminant analysis that allows automatic authorship classification of opinion column articles. First, we extract the following stylometric features of 157 column articles from four authors: statistics on high frequency words, number of words per sentence, and number of sentences per paragraph. Then, by systematically ranking these features based on an effect size criterion, we show that we can achieve an average classification accuracy of 93% for the test set. In comparison, frequency size based ranking has an average accuracy of 80%. The highest possible average classification accuracy of our data merely relying on chance is ∼31%. By carrying out sensitivity analysis, we show that the effect size criterion is superior than frequency ranking because there exist low frequency words that significantly contribute to successful author discrimination. Consistent results are seen when the procedure is applied in classifying the undisputed Federalist papers of Alexander Hamilton and James Madison. To the best of our knowledge, the work is the first attempt in classifying opinion column articles, that by virtue of being shorter in length (as compared to novels or short stories), are more prone to over-fitting issues. The near perfect classification for the longer papers supports this claim. Our results provide an important insight on authorship attribution that has been overlooked in previous studies: that ranking discriminant variables based on word frequency counts is not necessarily an optimal procedure.

In Other Sources

ERIC Educational Resources Information Center

Konrad, Moira; Freeman, Shaqwana M.; Bartholomew, Audrey; Kelley, Kelly R.; Cease-Cook, Jennifer; Flynn, Susan D.; Scroggins, La' Shawndra; Fishley, Katelyn M.; Keesey, Susan; Fleming, Shannon S.; Toms, Ozalle M.; Rowe, Dawn A.

2011-01-01

This column provides brief summaries of transition-related articles published in 2010 in other professional journals. The 64 articles included descriptive, experimental, and qualitative research as well as program descriptions, conceptual articles, and practitioner pieces. Addressed were all areas of Kohler's (1996) taxonomy for transition…

Computational analysis of vertical axis wind turbine arrays

NASA Astrophysics Data System (ADS)

Bremseth, J.; Duraisamy, K.

2016-10-01

Canonical problems involving single, pairs, and arrays of vertical axis wind turbines (VAWTs) are investigated numerically with the objective of understanding the underlying flow structures and their implications on energy production. Experimental studies by Dabiri (J Renew Sustain Energy 3, 2011) suggest that VAWTs demand less stringent spacing requirements than their horizontal axis counterparts and additional benefits may be obtained by optimizing the placement and rotational direction of VAWTs. The flowfield of pairs of co-/counter-rotating VAWTs shows some similarities with pairs of cylinders in terms of wake structure and vortex shedding. When multiple VAWTs are placed in a column, the extent of the wake is seen to spread further downstream, irrespective of the direction of rotation of individual turbines. However, the aerodynamic interference between turbines gives rise to regions of excess momentum between the turbines which lead to significant power augmentations. Studies of VAWTs arranged in multiple columns show that the downstream columns can actually be more efficient than the leading column, a proposition that could lead to radical improvements in wind farm productivity.

Understanding star formation in molecular clouds. I. Effects of line-of-sight contamination on the column density structure

NASA Astrophysics Data System (ADS)

Schneider, N.; Ossenkopf, V.; Csengeri, T.; Klessen, R. S.; Federrath, C.; Tremblin, P.; Girichidis, P.; Bontemps, S.; André, Ph.

2015-03-01

Column-density maps of molecular clouds are one of the most important observables in the context of molecular cloud- and star-formation (SF) studies. With the Herschel satellite it is now possible to precisely determine the column density from dust emission, which is the best tracer of the bulk of material in molecular clouds. However, line-of-sight (LOS) contamination from fore- or background clouds can lead to overestimating the dust emission of molecular clouds, in particular for distant clouds. This implies values that are too high for column density and mass, which can potentially lead to an incorrect physical interpretation of the column density probability distribution function (PDF). In this paper, we use observations and simulations to demonstrate how LOS contamination affects the PDF. We apply a first-order approximation (removing a constant level) to the molecular clouds of Auriga and Maddalena (low-mass star-forming), and Carina and NGC 3603 (both high-mass SF regions). In perfect agreement with the simulations, we find that the PDFs become broader, the peak shifts to lower column densities, and the power-law tail of the PDF for higher column densities flattens after correction. All corrected PDFs have a lognormal part for low column densities with a peak at Av ~ 2 mag, a deviation point (DP) from the lognormal at Av(DP) ~ 4-5 mag, and a power-law tail for higher column densities. Assuming an equivalent spherical density distribution ρ ∝ r- α, the slopes of the power-law tails correspond to αPDF = 1.8, 1.75, and 2.5 for Auriga, Carina, and NGC 3603. These numbers agree within the uncertainties with the values of α ≈ 1.5,1.8, and 2.5 determined from the slope γ (with α = 1-γ) obtained from the radial column density profiles (N ∝ rγ). While α ~ 1.5-2 is consistent with a structure dominated by collapse (local free-fall collapse of individual cores and clumps and global collapse), the higher value of α > 2 for NGC 3603 requires a physical process that leads to additional compression (e.g., expanding ionization fronts). From the small sample of our study, we find that clouds forming only low-mass stars and those also forming high-mass stars have slightly different values for their average column density (1.8 × 1021 cm-2 vs. 3.0 × 1021 cm-2), and they display differences in the overall column density structure. Massive clouds assemble more gas in smaller cloud volumes than low-mass SF ones. However, for both cloud types, the transition of the PDF from lognormal shape into power-law tail is found at the same column density (at Av ~ 4-5 mag). Low-mass and high-mass SF clouds then have the same low column density distribution, most likely dominated by supersonic turbulence. At higher column densities, collapse and external pressure can form the power-law tail. The relative importance of the twoprocesses can vary between clouds and thus lead to the observed differences in PDF and column density structure. Appendices are available in electronic form at http://www.aanda.orgHerschel maps as FITS files are only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (ftp://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/575/A79

Recognizing the Importance of Leadership: A Recent Graduate Develops a Corpsman.

PubMed

Hartzell, Joshua D; Gilbert, Laura

2018-01-01

There is a growing interest in leadership development within the field of medicine both within the military and the larger medical community. Recognition of the importance of leadership training during graduate medical education has grown, but many residents and faculty still argue that residency training should focus on clinical skills and medical knowledge. Most graduates of training programs in the military quickly find themselves in formal leadership positions or they must informally lead in their clinical practice. As these new graduates enter practice, they quickly realize the need to be able to effectively lead. In order to highlight some of the leadership challenges that junior military physicians face, Military Medicine is starting a new column called "Leadership Lessons from the Field." This article is the first in the series and discusses a recent graduate's experience in dealing with an underperforming corpsman. The article reviews the importance of emotional intelligence, feedback, and goal setting. Published by Oxford University Press on behalf of the Association of Military Surgeons of the United States 2017. This work is written by (a) US Government employee(s) and is in the public domain in the US.

Inklings: Collected Columns on Leadership and Creativity.

ERIC Educational Resources Information Center

Campbell, David P.

This book brings together 35 of David P. Campbell's essays originally published as a regular column in a quarterly publication called "Issues and Observations." The articles deal with topics ranging from leadership issues such as risk-taking, executive motivation, decision making, and corporate taboos, to more general concerns such as…

Contexts for Column Addition and Subtraction

ERIC Educational Resources Information Center

Lopez Fernandez, Jorge M.; Velazquez Estrella, Aileen

2011-01-01

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

Reliability assessment of slender concrete columns at the stability failure

NASA Astrophysics Data System (ADS)

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.

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

PubMed Central

Plenis, Alina; Rekowska, Natalia; Bączek, Tomasz

2016-01-01

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. PMID:26805819

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

PubMed

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.

Magnetic microbes: Bacterial magnetite biomineralization

DOE PAGES

Prozorov, Tanya

2015-09-14

Magnetotactic bacteria are a diverse group of prokaryotes with the ability to orient and migrate along the magnetic field lines in search for a preferred oxygen concentration in chemically stratified water columns and sediments. These microorganisms produce magnetosomes, the intracellular nanometer-sized magnetic crystals surrounded by a phospholipid bilayer membrane, typically organized in chains. Magnetosomes have nearly perfect crystal structures with narrow size distribution and species-specific morphologies, leading to well-defined magnetic properties. As a result, the magnetite biomineralization in these organisms is of fundamental interest to diverse disciplines, from biotechnology to astrobiology. As a result, this article highlights recent advances inmore » the understanding of the bacterial magnetite biomineralization.« less

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

PubMed

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

2018-06-01

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

Fabrication and investigation of electrochromatographic columns with a simplex configuration.

PubMed

Liu, Qing; Yang, Lijun; Wang, Qiuquan; Zhang, Bo

2014-07-04

Duplex capillary columns with a packed and an open section are widely used in electrochromatography (CEC). The duplex column configuration leads to non-uniform voltage drop, electrical field distribution and separation performance. It also adds to the complexity in understanding and optimizing electrochromatographic process. In this study, we introduced a simplex column configuration based on single particle fritting technology. The new column configuration has an essentially uniform packed bed through the entire column length, with only 1mm length left unpacked serving as the optical detection window. The study shows that a simplex column has higher separation efficiency than a duplex column, especially at the high voltage range, due to the consistent distribution of electrical field over the column length. In comparison to the duplex column, the simplex column presented a lower flow rate at the same applied voltage, suggesting that an open section may support a higher speed than a packed section. In practice, the long and short ends of the simplex column could be used as independent CEC columns respectively. This "two-in-one" bi-functional column configuration provided extra flexibilities in selecting and optimizing electrochromatographic conditions. Copyright © 2014 Elsevier B.V. All rights reserved.

Modeling Stone Columns.

PubMed

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.

Modeling Stone Columns

PubMed Central

2017-01-01

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. PMID:28773146

Religion, Politics, and Paris Hilton: Case Study

ERIC Educational Resources Information Center

Rogers, Michael

2005-01-01

This article was sent into a column of "Library Journal" entitled "How Do You Manage?" Submissions to this column, are based on actual events in libraries across the United States and Canada. This particular piece describes a conversation between two library employees, where one, following a recovery from a devastating auto accident found…

Cyclic performance of concrete-filled steel batten built-up columns

NASA Astrophysics Data System (ADS)

Razzaghi, M. S.; Khalkhaliha, M.; Aziminejad, A.

2016-03-01

Steel built-up batten columns are common types of columns in Iran and some other parts of the world. They are economic and have acceptable performance due to gravity loads. Although several researches have been conducted on the behavior of the batten columns under axial loads, there are few available articles about their seismic performance. Experience of the past earthquakes, particularly the 2003 Bam earthquake in Iran, revealed that these structural members are seismically vulnerable. Thus, investigation on seismic performance of steel batten columns due to seismic loads and providing a method for retrofitting them are important task in seismic-prone areas. This study aims to investigate the behavior of concrete-filled batten columns due to combined axial and lateral loads. To this end, nonlinear static analyses were performed using ANSYS software. Herein, the behaviors of the steel batten columns with and without concrete core were compared. The results of this study showed that concrete-filled steel batten columns, particularly those filled with high-strength concrete, may cause significant increases in energy absorption and capacity of the columns. Furthermore, concrete core may improve post-buckling behavior of steel batten columns.

Health Care Worker Fatigue.

PubMed

Gardner, Lea Anne; Dubeck, Deborah

2016-08-01

The Pennsylvania Patient Safety Reporting System is a confidential, statewide Internet reporting system to which all Pennsylvania hospitals, outpatient-surgery facilities, birthing centers, and abortion facilities must file information on incidents and serious events.Safety Monitor is a column from Pennsylvania's Patient Safety Authority, the authority that informs nurses on issues that can affect patient safety and presents strategies they can easily integrate into practice. For more information on the authority, visit www.patientsafetyauthority.org. For the original article discussed in this column or for other articles on patient safety, click on "Patient Safety Advisories" and then "Advisory Library" in the left-hand navigation menu.

The handedness of historiated spiral columns.

PubMed

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.

Real-time quality monitoring in debutanizer column with regression tree and ANFIS

NASA Astrophysics Data System (ADS)

Siddharth, Kumar; Pathak, Amey; Pani, Ajaya Kumar

2018-05-01

A debutanizer column is an integral part of any petroleum refinery. Online composition monitoring of debutanizer column outlet streams is highly desirable in order to maximize the production of liquefied petroleum gas. In this article, data-driven models for debutanizer column are developed for real-time composition monitoring. The dataset used has seven process variables as inputs and the output is the butane concentration in the debutanizer column bottom product. The input-output dataset is divided equally into a training (calibration) set and a validation (testing) set. The training set data were used to develop fuzzy inference, adaptive neuro fuzzy (ANFIS) and regression tree models for the debutanizer column. The accuracy of the developed models were evaluated by simulation of the models with the validation dataset. It is observed that the ANFIS model has better estimation accuracy than other models developed in this work and many data-driven models proposed so far in the literature for the debutanizer column.

Lead from hunting activities and its potential environmental threat to wildlife in a protected wetland in Yucatan, Mexico.

PubMed

Arcega-Cabrera, Flor; Noreña-Barroso, Elsa; Oceguera-Vargas, Ismael

2014-02-01

This study provides insights into the status of lead in the protected wetland of El Palmar, located on the northwestern littoral of the Yucatan Peninsula. This reserve is ecologically and economically important because it provides feeding and breeding habitats for many species, as well as being an ecotourism destination (especially for bird watching). Although it is a protected area, duck species are heavily hunted within the reserve during the winter. As a result, animals feeding or living in sediments could be exposed to anthropogenic lead. Total lead and its geochemical fractionated forms were measured in sediment cores from six selected sites in "El Palmar" wetland, during pre- and post-hunting seasons, to approximate the potential environmental threat (especially for benthonic living/feeding organisms). Anthropogenic lead concentrations detected in soil cores ranged from below the minimum infaunal community effect level (30.24 μg g(-1)) during the pre-hunting season, to bordering the probable infaunal community effect level (112.18 μg g(-1)) during the post-hunting season, according to SquiiRTs NOAA guidelines. Yet, these results were lower than expected based on the intensity of hunting. Consequently, this article explores the possibility that the lower than expected lead concentration in sediments results from (1) degradation of shot and transformation to soluble or particulate forms; or (2) ingestion of lead shot by benthic and other lacustrine species living in the protected area. Geochemical fractionation of lead demonstrated that in the top 6 cm of the soil column at heavily active hunting sites (EP5 and EP6), lead was associated with the lithogenic fraction (average 45 percent) and with the organic fraction (average 20 percent). Bioavailable lead (sum of lead adsorbed to the carbonates, Fe/Mn oxyhydroxides and organic fractions) in sediments was lower than 50 percent for the heavily active hunting areas and higher for the rest of the sites. Multivariate analysis showed that the environmental chemistry, the physicochemical characteristics of the water, and the geochemical qualities of the sediments do not favor the release of lead into the water column. Thus, the direct consumption of lead shot by organisms feeding in sea grass or in the top 10 cm of sediment is perhaps the major process preventing lead from being deposited in sediments, and, as such, these species (e.g., flamingos and/or ducks) could be threatened by anthropogenic lead pollution. © 2013 Published by Elsevier Inc.

ANION EXCHANGE METHOD FOR SEPARATION OF METAL VALUES

DOEpatents

Hyde, E.K.; Raby, B.A.

1959-02-10

A method is described for selectively separating radium, bismuth, poloniums and lead values from a metallic mixture of thc same. The mixture is dissolved in aqueous hydrochloric acid and the acidity is adjusted to between 1 to 2M in hydrochloric acid to form the anionic polychloro complexes of polonium and bismuth. The solution is contacted with a first anion exchange resin such as strong base quaternary ammonia type to selectively absorb the polonium and bismuth leaving the radium and lead in the effluent. The effluent, after treatment in hydrochloric acid to increase the hydrochloric acid concentration to 6M is contacted with a second anion exchange iesin of the same type as the above to selectively adsorb the lead leaving the radium in the effluent. Radium is separately recovered from the effluent from the second exchange column. Lead is stripped from the loaded resin of the second column by treatment with 3M hydrochloric acid solution. The loaded resin of the first column is washed with 8M hydrochloric acid solution to recover bismuth and then treated with strong nitric acid solution to recover polonium.

Evaluation of 1.0 mm i.d. column performances on ultra high pressure liquid chromatography instrumentation.

PubMed

Lestremau, François; Wu, Di; Szücs, Roman

2010-07-23

The present study focuses on the evaluation of 1.0 mm i.d. (internal diameter) columns on a commercial Ultra-High Pressure system. These systems have been developed specifically to operate columns with small volumes, typically 2.1 mm i.d., by reducing extra-column volume dispersion. The use of columns with smaller i.d. results in a reduced solvent consumption and required sample volume. The evaluation of the columns was carried out with samples containing neutral and pharmaceutical compounds. In isocratic mode, the extra-column volume produced additional band broadening leading to poor performances compared to equivalent 2.1 mm i.d. columns. By increasing the length of the column, the influence of the extra-column bandspreading could be reduced and 75,000 plates were obtained when four columns were coupled. In gradient mode, the effect of the extra-column contribution on efficiency was limited and about 80% of the performance of the 2.1 mm i.d. columns was obtained. Optimum conditions in gradient mode were further investigated by changing flow rate, gradient time and column length. A different approach of the calculation of peak capacity was also considered for the comparison of the influence of these different parameters. Copyright (c) 2010 Elsevier B.V. All rights reserved.

Influence of phosphate on the transport properties of lead in sand.

PubMed

Butkus, Michael A; Johnson, Marie C

2011-01-15

Temporal moment analysis was used to examine the transport of lead species in sand columns. The influence of sodium phosphate (PO(4(aq))) and hydroxyapatite (HA) on lead transport was also evaluated. Transport properties of lead microparticles (diameter>0.45 μm) were a function of electrophoretic mobility: those particles with electrophoretic mobility less than -1 × 10(-8)m(2)/Vs exhibited significantly lower dimensionless first temporal moment (θ) and second temporal moment (σ(θ)(2)). The forms of lead investigated in this work had a tendency to move in sand over a wide pH range. Although the PO(4(aq)) amendment substantially reduced lead mass recoveries in the sand column effluent, lead microparticles were formed that had a tendency to move rapidly and with minimal dispersion when compared with controls. Treatments with HA provided limited reduction in lead mass recovery and minimal changes in lead transport properties. A colloid stability model was used to predict attachment of lead particles in sand. Published by Elsevier B.V.

Drawing Blueprints for "Pulsing Content" Libraries

ERIC Educational Resources Information Center

Chudnov, Daniel

2007-01-01

This column presents a continuation of an article published in last month's issue of "Libraries in Computers," in which the author began to consider what it might mean to build dynamic, instantaneous libraries based solely on the materials held on the computers of people in the same space. The goal of this column is to think about what libraries…

Ammonium pyrrolidine dithiocarbamate anchored Symphoricarpus albus biomass for lead(II) removal: batch and column biosorption study.

PubMed

Akar, Sibel Tunali; Arslan, Derya; Alp, Tugba

2012-08-15

The biosorption properties of APDC modified S. albus were tested in batch and column conditions. Effective experimental parameters such as pH, biosorbent dosage, contact time, temperature, initial lead(II) ion concentration, flow rate and bed height were investigated. The biosorption capacity of modified biosorbent was at maximum when lead(II) solution pH and biosorbent dosage were 5.5 and 2.0 g L(-1), respectively. The biosorption equilibrium was established in 20 min. Langmuir isotherm fitted well to the equilibrium data and kinetics is found to fit pseudo-second-order model. Increase in ionic strength of lead(II) solutions caused a slight decrease in the biosorption yield of APDC-modified biosorbent. Co-ions affected the biosorption performance of modified biomass up to maximum 20.81% reduction. Column biosorption of lead(II) showed higher biosorption yields at lower flow rates. Required time of breakthrough point was found to be 200 min. The recommended mechanism was found to depend mainly on electrostatic interaction, ion-exchange and complex formation. The ion-exchange mechanism for lead(II) biosorption onto the modified biosorbent is verified from the ionic strength effect and EDX analysis. Carbonyl, phosphate and CN groups on the modified surface of S. albus were found to responsible for complexation with lead(II). Copyright © 2012 Elsevier B.V. All rights reserved.

Fabrication and characterization of microelectromechanical systems-based gas chromatography column with embedded micro-posts for separation of environmental carcinogens.

PubMed

Sun, Jianhai; Cui, Dafu; Chen, Xing; Zhang, Lulu; Cai, Haoyuan; Li, Hui

2013-05-24

In this paper, a micro gas chromatography (μGC) column with embedded micro-posts was developed for increasing overall surface area of the columns which is able to support more of the stationary phase and reducing the effective width of the column, leading to higher separation efficiency. The proposed columns have a higher sample capacity as the overall surface area is about 3 times larger than that of open columns with the same dimensions. In order to achieve an even flow velocity in the channels, the location of the micro-posts in the linear channels and the configuration of curved channels were optimized by numerical simulation. The results have indicated that the proposed column separated 5 environmental carcinogens in less than 50s, achieved a separation efficiency of about 9500plates/m and eluted highly symmetrical Gaussian peaks. Copyright © 2013 Elsevier B.V. All rights reserved.

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

PubMed

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.

Method of separating short half-life radionuclides from a mixture of radionuclides

DOEpatents

Bray, Lane A.; Ryan, Jack L.

1999-01-01

The present invention is a method of removing an impurity of plutonium, lead or a combination thereof from a mixture of radionuclides that contains the impurity and at least one parent radionuclide. The method has the steps of (a) insuring that the mixture is a hydrochloric acid mixture; (b) oxidizing the acidic mixture and specifically oxidizing the impurity to its highest oxidation state; and (c) passing the oxidized mixture through a chloride form anion exchange column whereupon the oxidized impurity absorbs to the chloride form anion exchange column and the 22.sup.9 Th or 2.sup.27 Ac "cow" radionuclide passes through the chloride form anion exchange column. The plutonium is removed for the purpose of obtaining other alpha emitting radionuclides in a highly purified form suitable for medical therapy. In addition to plutonium; lead, iron, cobalt, copper, uranium, and other metallic cations that form chloride anionic complexes that may be present in the mixture; are removed from the mixture on the chloride form anion exchange column.

Method of separating short half-life radionuclides from a mixture of radionuclides

DOEpatents

Bray, L.A.; Ryan, J.L.

1999-03-23

The present invention is a method of removing an impurity of plutonium, lead or a combination thereof from a mixture of radionuclides that contains the impurity and at least one parent radionuclide. The method has the steps of (a) insuring that the mixture is a hydrochloric acid mixture; (b) oxidizing the acidic mixture and specifically oxidizing the impurity to its highest oxidation state; and (c) passing the oxidized mixture through a chloride form anion exchange column whereupon the oxidized impurity absorbs to the chloride form anion exchange column and the {sup 229}Th or {sup 227}Ac ``cow`` radionuclide passes through the chloride form anion exchange column. The plutonium is removed for the purpose of obtaining other alpha emitting radionuclides in a highly purified form suitable for medical therapy. In addition to plutonium, lead, iron, cobalt, copper, uranium, and other metallic cations that form chloride anionic complexes that may be present in the mixture are removed from the mixture on the chloride form anion exchange column. 8 figs.

Influence of the gas-flow Reynolds number on a plasma column in a glass tube

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

Jin, Dong Jun; Uhm, Han S.; Cho, Guangsup

2013-08-15

Atmospheric-plasma generation inside a glass tube is influenced by gas stream behavior as described by the Reynolds number (Rn). In experiments with He, Ne, and Ar, the plasma column length increases with an increase in the gas flow rate under laminar flow characterized by Rn < 2000. The length of the plasma column decreases as the flow rate increases in the transition region of 2000 < Rn < 4000. For a turbulent flow beyond Rn > 4000, the length of the plasma column is short in front of the electrode, eventually leading to a shutdown.

Helping learners level up with cognitive supports.

PubMed

Malenczak, Derek; Nemec, Patricia B

2017-03-01

This column describes strategies for helping educators and trainers address common problems with executive functioning and memory for their audiences, to better facilitate learning. The purpose of the article is to suggest strategies for maximizing learning and goal achievement for students in academic settings, as well as for building employee knowledge and skills in the psychiatric rehabilitation workforce through worksite-based training. The content in this column is drawn from the professional experience of the authors as well as available literature. Educators and trainers encounter many challenges when assisting people to achieve desired learning objectives. Attending to the cognitive needs of all learners, by supporting their planning, attention, memory, and reasoning skills, can minimize some of these challenges. Educators and trainers may implement the strategies described to better engage with their audiences, whether in an academic or clinical practice environment. Implementation of specific strategies to offset limitations will positively affect all learners, who benefit both from maximized knowledge and skill acquisition as well as improved job performance. Improved learning will likely translate to better practitioner skill over time, which should lead to improved outcomes for service users in the field of psychiatric rehabilitation. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

Case Study: Writing a Journal Case Study

ERIC Educational Resources Information Center

Prud'homme-Genereux, Annie

2016-01-01

This column provides original articles on innovations in case study teaching, assessment of the method, as well as case studies with teaching notes. This month's issue describes incorporating a journal article into the classroom by first converting it into a case study.

Research Exchange, 2000.

ERIC Educational Resources Information Center

Research Exchange, 2000

2000-01-01

Three issues of this newsletter of the National Institute on Disability and Rehabilitation Research (NIDRR) provide articles, columns by the Institute Director, and news items. The major articles include: "Adapting the Marketing Concept to the Dissemination and Utilization of Disability Research"; "NIDRR Grantees' Q & A about…

Caring for class III obese patients.

PubMed

Gardner, Lea Anne

2013-11-01

The Pennsylvania Patient Safety Reporting System is a confidential, statewide Internet reporting system to which all Pennsylvania hospitals, outpatient-surgery facilities, and birthing centers, as well as some abortion facilities, must file information on medical errors.Safety Monitor is a column from Pennsylvania's Patient Safety Authority, the authority that informs nurses on issues that can affect patient safety and presents strategies they can easily integrate into practice. For more information on the authority, visit www.patientsafetyauthority.org. For the original article discussed in this column or for other articles on patient safety, click on "Patient Safety Advisories" and then "Advisory Library" in the left-hand navigation menu.

Understanding Hospital Value-Based Purchasing.

PubMed

Brooks, Jo Ann

2016-05-01

This column is designed to provide a nursing perspective on new hospital quality measurements. Future articles will cover the various quality indicators hospitals face and the role of the nurse in meeting mandated benchmarks. Reader responses to this column are welcome and will help to make it more useful to nurses in meeting the challenges posed by health care reform and changing Medicare reimbursement programs.

Continuous-Flow MOVPE of Ga-Polar GaN Column Arrays and Core-Shell LED Structures

NASA Astrophysics Data System (ADS)

Wang, Xue; Li, Shunfeng; Mohajerani, Matin Sadat; Ledig, Johannes; Wehmann, Hergo-Heinrich; Mandl, Martin; Strassburg, Martin; Steegmüller, Ulrich; Jahn, Uwe; Lähnemann, Jonas; Riechert, Henning; Griffiths, Ian; Cherns, David; Waag, Andreas

2013-06-01

Arrays of dislocation free uniform Ga-polar GaN columns have been realized on patterned SiOx/GaN/sapphire templates by metal organic vapor phase epitaxy using a continuous growth mode. The key parameters and the physical principles of growth of Ga-polar GaN three-dimensional columns are identified, and their potential for manipulating the growth process is discussed. High aspect ratio columns have been achieved using silane during the growth, leading to n-type columns. The vertical growth rate increases with increasing silane flow. In a core-shell columnar LED structure, the shells of InGaN/GaN multi quantum wells and p-GaN have been realized on a core of n-doped GaN column. Cathodoluminescence gives insight into the inner structure of these core-shell LED structures.

In Other Sources

ERIC Educational Resources Information Center

Konrad, Moira; Luu, Ken C. T.; Rowe, Dawn A.; Mazzotti, Valerie L.; Kelley, Kelly R.; Mustian, April L.; Keesey, Susan; Fishley, Katelyn M.

2009-01-01

This column provides brief summaries of transition-related articles published in 2008 in other professional journals. The 70 articles included descriptive, experimental, and qualitative research as well as program descriptions, conceptual papers, and practitioner pieces. All areas of Kohler's (1996) Kohler, P. D. (1996). "Preparing youth with…

AAHE Bulletin, 1999-2000.

ERIC Educational Resources Information Center

Hendley, Vicky, Ed.

2000-01-01

The 10 issues of this organizational journal provide news columns, calls for proposals, conference information, and several major articles. Articles in this volume include: (1) "New Path, Same Goal: An Interview with Blenda Wilson" (Miller); (2) "Making a Difference: Service Learning as an Activism Catalyst and Community…

Successful Surgical Treatment for Elephantiasis Nostras Verrucosa Using a New Designed Column Flap.

PubMed

Han, Hyun Ho; Lim, Soo Yeon; Oh, Deuk Young

2015-09-01

Elephantiasis nostras verrucosa is a chronic lymphedema that causes enlarged and disfigured extremities. There are plenty of treatment options. However, there is no complete treatment. Preventive or symptomatic therapy is the basis for treating elephantiasis. In this article, we report a case of elephantiasis nostras verrucosa treated successfully by surgical reconstruction using a newly designed column flap. © The Author(s) 2015.

Multi-gradient drilling method and system

DOEpatents

Maurer, William C.; Medley, Jr., George H.; McDonald, William J.

2003-01-01

A multi-gradient system for drilling a well bore from a surface location into a seabed includes an injector for injecting buoyant substantially incompressible articles into a column of drilling fluid associated with the well bore. Preferably, the substantially incompressible articles comprises hollow substantially spherical bodies.

Publisher Correction: Probing the strongly driven spin-boson model in a superconducting quantum circuit.

PubMed

Magazzù, L; Forn-Díaz, P; Belyansky, R; Orgiazzi, J-L; Yurtalan, M A; Otto, M R; Lupascu, A; Wilson, C M; Grifoni, M

2018-06-07

The original PDF and HTML versions of this Article omitted the ORCID ID of the authors L. Magazzù and P. Forn-Díaz. (L. Magazzù: 0000-0002-4377-8387; P. Forn-Diaz: 0000-0003-4365-5157).The original PDF version of this Article contained errors in Eqs. (2), (6), (13), (14), (25), (26). These equations were missing all instances of 'Γ' and 'Δ', which are correctly displayed in the HTML version.Similarly, the inline equation in the third sentence of the caption of Fig. 2 was missing the left hand term 'Ω'.The original HTML version of this Article contained errors in Table 1. The correct version of the sixth row of the first column states 'Figure 2' instead of the original, incorrect 'Figure'. And the correction version of the ninth row of the first column states 'Figure 3' instead of the original, incorrect 'Figure'.This has been corrected in both the PDF and HTML versions of the Article.

Winning at Child Caring: Easier Ways with Young Children in Child Care Centers, Homes and Malls.

ERIC Educational Resources Information Center

Simons, Bette

This booklet is a compilation of articles from a column in the "Warner Center News" written by an experienced early childhood educator on various topics related to child care. The brief articles describe the problems and pleasures that preschool children bring to child care centers, homes, markets, and malls. The articles are grouped…

Stability and Structure of Star-Shape Granules

NASA Astrophysics Data System (ADS)

Zhao, Yuchen; Bares, Jonathan; Zheng, Matthew; Dierichs, Karola; Menges, Achim; Behringer, Robert

2015-11-01

Columns are made of convex non-cohesive grains like sand collapse after being released from initial positions. On the other hand, various architectures built by concave grains can maintain stability. We explore why these structures are stable, and how stable they can be. We performed experiments by randomly pouring identical star-shape particles into hollow cylinders left on glass and a rough base, and observed stable granular columns after lifting the cylinders. Particles have six 9 mm arms, which extend symmetrically in the xyz directions. Both the probability of creating a stable column and mechanical stability aspects have been investigated. We define r as the weight fraction of particles that fall out of the column after removing confinement. r gradually increases as the column height increases, or the column diameter decreases. We also explored different experiment conditions such as vibration of columns with confinement, or large basal friction. We also consider different stability measures such as the maximum inclination angle or maximum weight a column can support. In order to understand structure leading to stability, 3D CT scan reconstructions of columns have been done and coordination number and packing density will be discussed. We acknowledge supports from W.M.Keck Foundation and Research Triangle MRSEC.

AAHE Bulletin, 1998-99.

ERIC Educational Resources Information Center

Marchese, Theodore J., Ed.

1999-01-01

The 10 issues of this organizational journal provide news columns, calls for proposals, conference information, and several major articles. Articles in this volume include: "Restructure? You Bet! An Interview with Change Expert Alan E. Guskin" (Ted Marchese); "The State of the 'Engaged Campus'" (Barbara A. Holland and Sherril B. Gelmon); "What…

Steel-reinforced concrete-filled steel tubular columns under axial and lateral cyclic loading

NASA Astrophysics Data System (ADS)

Farajpourbonab, Ebrahim; Kute, Sunil Y.; Inamdar, Vilas M.

2018-03-01

SRCFT columns are formed by inserting a steel section into a concrete-filled steel tube. These types of columns are named steel-reinforced concrete-filled steel tubular (SRCFT) columns. The current study aims at investigating the various types of reinforcing steel section to improve the strength and hysteresis behavior of SRCFT columns under axial and lateral cyclic loading. To attain this objective, a numerical study has been conducted on a series of composite columns. First, FEM procedure has been verified by the use of available experimental studies. Next, eight composite columns having different types of cross sections were analyzed. For comparison purpose, the base model was a CFT column used as a benchmark specimen. Nevertheless, the other specimens were SRCFT types. The results indicate that reinforcement of a CFT column through this method leads to enhancement in load-carrying capacity, enhancement in lateral drift ratio, ductility, preventing of local buckling in steel shell, and enhancement in energy absorption capacity. Under cyclic displacement history, it was observed that the use of cross-shaped reinforcing steel section causes a higher level of energy dissipation and the moment of inertia of the reinforcing steel sections was found to be the most significant parameter affecting the hysteresis behavior of SRCFT columns.

Continuous hemoadsorption with a cytokine adsorber during sepsis - a review of the literature.

PubMed

Houschyar, Khosrow S; Pyles, Malcolm N; Rein, Susanne; Nietzschmann, Ina; Duscher, Dominik; Maan, Zeshaan N; Weissenberg, Kristian; Philipps, Hubertus M; Strauss, Catharina; Reichelt, Beate; Siemers, Frank

2017-05-29

Sepsis is a well-recognized healthcare issue worldwide, ultimately resulting in significant mortality, morbidity and resource utilization during and after critical illness. In its most severe form, sepsis causes multi-organ dysfunction that produces a state of critical illness characterized by severe immune dysfunction and catabolism. Sepsis induces the activation of complement factor via 3 pathways and the release of inflammatory cytokines such as tumor necrosis factor alpha (TNF-α) and interleukin-1beta (IL-1β), resulting in a systemic inflammatory response. The inflammatory cytokines and nitric oxide release induced by sepsis decrease systemic vascular resistance, resulting in profound hypotension. The combination of hypotension and microvascular occlusion results in tissue ischemia and ultimately leads to multiple organ failure. Several clinical and experimental studies have reported that treatment using adsorption of cytokines is beneficial during endotoxemia and sepsis. This review article analyzes the efficacy of CytoSorb® adsorber in reducing the inflammatory response during sepsis. The CytoSorb® adsorber is known to have excellent adsorption rates for inflammatory cytokines such as IL-1β, IL-6, IL-8, IL-10, and TNF-α. Studies have demonstrated that treatment with cytokine adsorbing columns has beneficial effects on the survival rate and inflammatory responses in animal septic models. Additionally, several cases have been reported in which treatment with cytokine adsorbing columns is very effective in hemodynamic stabilization and in preventing organ failure in critically ill patients. Although further investigations and clinical trials are needed, treatment with cytokine adsorbing columns may play an important role in the treatment of sepsis in the near future.

The column strength of aluminum alloy 75S-T extruded shapes

NASA Technical Reports Server (NTRS)

Holt, Marshall; Leary, J R

1946-01-01

Because the tensile strength and tensile yield strength of alloy 75S-T are appreciably higher than those of the materials used in the tests leading to the use of the straight-line column curve, it appeared advisable to establish the curve of column strength by test rather than by extrapolation of relations determined empirically in the earlier tests. The object of this investigation was to determine the curve of column strength for extruded aluminum alloy 75S-T. In addition to three extruded shapes, a rolled-and-drawn round rod was included. Specimens of various lengths covering the range of effective slenderness ratios up to about 100 were tested.

Compression-bending of multi-component semi-rigid columns in response to axial loads and conjugate reciprocal extension-prediction of mechanical behaviours and implications for structural design.

PubMed

Lau, Ernest W

2013-01-01

The mathematical modelling of column buckling or beam bending under an axial or transverse load is well established. However, the existent models generally assume a high degree of symmetry in the structure of the column and minor longitudinal and transverse displacements. The situation when the column is made of several components with different mechanical properties asymmetrically distributed in the transverse section, semi-rigid, and subjected to multiple axial loads with significant longitudinal and transverse displacements through compression and bending has not been well characterised. A more comprehensive theoretical model allowing for these possibilities and assuming a circular arc contour for the bend is developed, and used to establish the bending axes, balance between compression and bending, and equivalent stiffness of the column. In certain situations, such as with pull cable catheters commonly used for minimally invasive surgical procedures, the compression loads are applied via cables running through channels inside a semi-rigid column. The model predicts the mathematical relationships between the radius of curvature of the bend and the tension in and normal force exerted by such cables. Conjugate extension with reciprocal compression-bending is a special structural arrangement for a semi-rigid column such that extension of one segment is linked to compression-bending of another by inextensible cables running between them. Leads are cords containing insulated electrical conductor coil and cables between the heart muscle and cardiac implantable electronic devices. Leads can behave like pull cable catheters through differential component pulling, providing a possible mechanism for inside-out abrasion and conductor cable externalisation. Certain design features may predispose to this mode of structural failure. Copyright © 2012 Elsevier Ltd. All rights reserved.

Students and the Law.

ERIC Educational Resources Information Center

Gluckman, Ivan B.

This publication consists of 29 articles that were published between April 1974 and June 1977 in the "Students and the Law" column of the National Association of Secondary School Principals' magazine, the "Student Advocate." In editing the articles, an attempt has been made to eliminate or update any suggestions or conclusions that may have been…

Middle Level Learning Number 48

ERIC Educational Resources Information Center

Freedman, Eric B.; Roberts, Scott L.

2013-01-01

Two articles are presented in this column. "Life in an Auto Factory: Simulating how Labor and Management Interact" by Eric B. Freedman describes a classroom simulation of management and labor relations in an auto factory. Classroom handouts are included. The next article, "Women of Action and County Names: Mary Musgrove County--Why…

Developmental mechanisms of intervertebral disc and vertebral column formation.

PubMed

Lawson, Lisa Y; Harfe, Brian D

2017-11-01

The vertebral column consists of repeating units of ossified vertebrae that are adjoined by fibrocartilagenous intervertebral discs. These structures form from the embryonic notochord and somitic mesoderm. In humans, congenital malformations of the vertebral column include scoliosis, kyphosis, spina bifida, and Klippel Feil syndrome. In adulthood, a common malady affecting the vertebral column includes disc degeneration and associated back pain. Indeed, recent reports estimate that low back pain is the number one cause of disability worldwide. Our review provides an overview of the molecular mechanisms underlying vertebral column morphogenesis and intervertebral disc development and maintenance, with an emphasis on what has been gleaned from recent genetic studies in mice. The aim of this review is to provide a developmental framework through which vertebral column formation can be understood so that ultimately, research scientists and clinicians alike can restore disc health with appropriately designed gene and cell-based therapies. WIREs Dev Biol 2017, 6:e283. doi: 10.1002/wdev.283 For further resources related to this article, please visit the WIREs website. © 2017 Wiley Periodicals, Inc.

Enhanced capabilities of separation in Sequential Injection Chromatography--fused-core particle column and its comparison with narrow-bore monolithic column.

PubMed

Chocholouš, Petr; Kosařová, Lucie; Satínský, Dalibor; Sklenářová, Hana; Solich, Petr

2011-08-15

In the Sequential Injection Chromatography (SIC) only monolithic columns for chromatographic separations have been used so far. This article presents the first use of fused-core particle packed column in an attempt to extend of the chromatographic capabilities of the SIC system. A new fused-core particle column (2.7 μm) Ascentis(®) Express C18 (Supelco™ Analytical) 30 mm × 4.6 mm brings high separation efficiency within flow rates and pressures comparable to monolithic column Chromolith(®) Performance RP-18e 100-3 (Merck(®)) 100 mm × 3 mm. Both columns matches the conditions of the commercially produced SIC system - SIChrom™ (8-port high-pressure selection valve and medium-pressure Sapphire™ syringe pump with 4 mL reservoir - maximal work pressure 1000 PSI) (FIAlab(®), USA). The system was tested by the separation of four estrogens with similar structure and an internal standard - ethylparaben. The mobile phase composed of acetonitrile/water (40/60 (v/v)) was pumped isocratic at flow rate 0.48 mL min(-1). Spectrophotometric detection was performed at wavelength of 225 nm and injected volume of sample solutions was 10 μL. The chromatographic characteristics of both columns were compared. Obtained results and conclusions have shown that both fused-core particle column and longer narrow shaped monolithic column bring benefits into the SIC method. Copyright © 2011 Elsevier B.V. All rights reserved.

Susceptibility of lava domes to erosion and collapse by toppling on cooling joints

NASA Astrophysics Data System (ADS)

Smith, John V.

2018-01-01

The shape of lava domes typically leads to the formation of radial patterns of cooling joints. These cooling joints define the orientation of the columnar blocks which plunge toward the center of the dome. In the lower parts of the dome the columns plunge into the dome at low angles and are relatively stable. Higher in the dome the columns plunge into the dome at steep angles. These steeply plunging columns are susceptible to toppling and, if the lower part of a dome is partially removed by erosion or collapse, the unstable part of the dome becomes exposed leading to toppling failure. Examples of this process are provided from coastal erosion of lava domes at Katsura Island, Shimane Peninsula, western Japan. An analogue model is presented to demonstrate the mechanism. It is proposed that the mechanism can contribute to collapse of lava domes during or after emplacement.

HPAC Info-dex 4: Locating recently published HPAC articles

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

NONE

1995-06-01

This is an alphabetical index of articles recently published in the Heating, Piping and Air Conditioning magazine. The lists include feature editorial material and articles from HPAC`s You`ll Want To Know Department. For each entry the month and year of publication are given, followed by the page number. Material is indexed by type of system, construction, or function. All regular columns are included.

Article Watch, April 2010

PubMed Central

Slaughter, Clive

2010-01-01

This column highlights recently published articles that are of interest to the readership of this publication. We encourage ABRF members to forward information about articles they feel are important and useful to Clive Slaughter, MCG-UGA Medical Partnership, 279 William St., Athens, GA 30607-1777, USA. Tel.: (706) 369-5945: Fax: (706) 369-5936; E-mail: cslaughter@mail.mcg.edu; or to any member of the editorial board. Article summaries reflect the reviewer's opinions and not necessarily those of the association.

Article Watch: April 2018

PubMed Central

Slaughter, Clive A.

2018-01-01

This column highlights recently published articles that are of interest to the readership of this publication. We encourage ABRF members to forward information on articles they feel are important and useful to Clive Slaughter, MCG-UGA Medical Partnership, 1425 Prince Ave., Athens, GA 30606, USA. Tel: (706) 713-2216; Fax: (706) 713-2221; E-mail: cslaught@uga.edu, or to any member of the editorial board. Article summaries reflect the reviewer’s opinions and not necessarily those of the association. PMID:29463959

Stability and dynamic analysis of a slender column with curved longitudinal stiffeners

NASA Technical Reports Server (NTRS)

Lake, Mark S.

1989-01-01

The results of a stability design study are presented for a slender column with curved longitudinal stiffeners for large space structure applications. Linear stability analyses are performed using a link-plate representation of the stiffeners to determine stiffener local buckling stresses. Results from a set of parametric analyses are used to determine an approximate explicit expression for stiffener local buckling in terms of its geometric parameters. This expression along with other equations governing column stability and mass are assembled into a determinate system describing minimum mass stiffened column design. An iterative solution is determined to solve this system and a computer program incorporating this routine is presented. Example design problems are presented which verify the solution accuracy and illustrate the implementation of the solution routine. Also, observations are made which lead to a greatly simplified first iteration design equation relating the percent increase in column mass to the percent increase in column buckling load. From this, generalizations are drawn as to the mass savings offered by the stiffened column concept. Finally, the percent increase in fundamental column vibration frequency due to the addition of deployable stiffeners is studied.

Utilizing a library of synthetic affinity ligands for the enrichment, depletion and one-step purification of leech proteins.

PubMed

Dong, Dexian; Gui, Yanli; Chen, Dezhao; Li, Rongxiu

2008-01-01

Although the concept of affinity purification using synthetic ligands had been utilized for many years, there are few articles related to this research area, and they focus only on the affinity purification of specific protein by a defined library of synthetic ligands. This study presents the design and construction of a 700-member library of synthetic ligands in detail. We selected 297 ligand columns from a 700-member library of synthetic ligands to screen leech protein extract. Of the 297, 154 columns had an enrichment effect, 83 columns had a depletion effect, 36 columns had a one-step purification effect, and 58 columns had a one-step purification via flowthrough effect. The experimental results achieved by this large library of affinity ligands provide solid convincing data for the theory that affinity chromatography could be used for the enrichment of proteins that are present in low abundance, the depletion of high abundance proteins, and one-step purification of special proteins. 2008 John Wiley & Sons, Ltd

Fixed bed column study for water defluoridation using neem oil-phenolic resin treated plant bio-sorbent.

PubMed

Manna, Suvendu; Saha, Prosenjit; Roy, Debasis; Adhikari, Basudam; Das, Papita

2018-04-15

Fluoride has both detrimental and beneficial effects on living beings depending on the concentration and consumption periods. The study presented in this article investigated the feasibility of using neem oil phenolic resin treated lignocellulosic bio-sorbents for fluoride removal from water through fixed bed column study. Results indicated that treated bio-sorbents could remove fluoride both from synthetic and groundwater with variable bed depth, flow rate, fluoride concentration and column diameter. Data obtained from this study indicated that columns with the thickest bed, lowest flow rate, and fluoride concentration showed best column performance. Bio-sorbents used in this study are regenerable and reusable for more than five cycles. The initial materials cost needed to remove one gram of fluoride also found to be lower than the available alternatives. This makes the process more promising candidate to be used for fluoride removal. In addition, the process is also technically advantageous over the available alternatives. Copyright © 2018 Elsevier Ltd. All rights reserved.

Counteracting moment device for reduction of earthquake-induced excursions of multi-level buildings.

PubMed

Nagaya, K; Fukushima, T; Kosugi, Y

1999-05-01

A vibration-control mechanism for beams and columns was presented in our previous report in which the earthquake force was transformed into a vibration-control force by using a gear train mechanism. In our previous report, however, only the principle of transforming the earthquake force into the control force was presented; the discussion for real structures and the design method were not presented. The present article provides a theoretical analysis of the column which is used in multi-layered buildings. Experimental tests were carried out for a model of multi-layered buildings in the frequency range of a principal earthquake wave. Theoretical results are compared to the experimental data. The optimal design of the control mechanism, which is of importance in the column design, is presented. Numerical calculations are carried out for the optimal design. It is shown that vibrations of the column involving the mechanism are suppressed remarkably. The optimal design method and the analytical results are applicable to the design of the column.

Superficially porous particles columns for super fast HPLC separations.

PubMed

Ali, Imran; Al-Othman, Zeid A; Al-Za'abi, Mohammed

2012-08-01

Superficially porous silica particles columns (SPSPCs) are manufactured by different companies. The most common have the brand names Halo, Ascentis Express and Kinetex. These columns provide super fast, sharp peaks and moderate sample loading and back pressure. These are available in different chemistries such as C₈, C₁₈, RP Amide and Hilic. Normally, the silica gel particles have 2.7 and 1.7 µm total and inner solid core diameters with 0.5 µm thick outer porous layer, 90 Å pore size and 150 m²/g surface area. They have been used for the separation and identification of low and high molecular weight compounds. The present article describes the state of the art of superficially porous silica particles based columns with special emphasis on their structures, mechanisms of separation, applications and comparison. Copyright © 2012 John Wiley & Sons, Ltd.

Stability and Structure of Star-Shape Granules

NASA Astrophysics Data System (ADS)

Zhao, Yuchen; Bares, Jonathan; Liu, Kevin; Zheng, Matthew; Dierichs, Karola; Menges, Achim; Behringer, Robert

Columns made of convex noncohesive grains like sand collapse after being released from a confining container. While various architectures built by concave grains are stable. We explore why these structures are stable, and how stable they can be. We performed experiments by randomly pouring identical star-shape particles into hollow cylinders resting on glass or a roughened base, and then observed how stable these granular columns were after carefully lifting the cylinders. We used particles that are made of acrylics and have six 9 mm arms, which extend symmetrically in xyz directions. We investigated the probability of creating a stable column and other mechanical stability aspects. We define r as the weight fraction of particles that fall out of the column after the confining cylinder is removed. r gradually increases as the column height increases, or the column diameter decreases. We found high column stability when the inter-particle friction was greater. We also explored experiment conditions such as initial vibration of columns when they were confined and loading on the top. In order to understand the inner structure leading to stability, we obtained 3D CT reconstruction data of stable columns. We will discuss coordination number and orientation, etc. We acknowledge supports from W.M.Keck Foundation and Research Triangle MRSEC.

Thermal Analysis for Ion-Exchange Column System

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

Lee, Si Y.; King, William D.

2012-12-20

Models have been developed to simulate the thermal characteristics of crystalline silicotitanate ion exchange media fully loaded with radioactive cesium either in a column configuration or distributed within a waste storage tank. This work was conducted to support the design and operation of a waste treatment process focused on treating dissolved, high-sodium salt waste solutions for the removal of specific radionuclides. The ion exchange column will be installed inside a high level waste storage tank at the Savannah River Site. After cesium loading, the ion exchange media may be transferred to the waste tank floor for interim storage. Models weremore » used to predict temperature profiles in these areas of the system where the cesium-loaded media is expected to lead to localized regions of elevated temperature due to radiolytic decay. Normal operating conditions and accident scenarios (including loss of solution flow, inadvertent drainage, and loss of active cooling) were evaluated for the ion exchange column using bounding conditions to establish the design safety basis. The modeling results demonstrate that the baseline design using one central and four outer cooling tubes provides a highly efficient cooling mechanism for reducing the maximum column temperature. In-tank modeling results revealed that an idealized hemispherical mound shape leads to the highest tank floor temperatures. In contrast, even large volumes of CST distributed in a flat layer with a cylindrical shape do not result in significant floor heating.« less

Spinal anatomy in an essential illustrated medical treatise of the late Ottoman era.

PubMed

Aciduman, Ahmet; Er, Uygur; Altuğ, Tibet

2013-01-01

The aim of this article is to introduce a great physician of the late Ottoman period and his writings on spinal anatomy. The article presents chapters related to the anatomy of vertebra and the vertebral column in the book of Şanizade Ataullah Mehmed, Mir'āt al-Abdān fı Tashrıḥ-i A'ḍāi'l-Insān (Mirror of the Bodies in the Dissection of the Members of the Human Body). Works of Şanizade are viewed as important landmarks in Turkish medical history. Anatomy education in Turkey can be divided into four historic periods and the second period is called the Şanizade Period (1816-1827). This period leads up to the opening of the first modern medical school in Turkey on March 14, 1827. The most important characteristic of Şanizade's work is that it is the first illustrated anatomy book printed in the Ottoman Age, and the value of the work is shown by Şanizade being one of the originators of medical terms in Ottoman Medicine. Copyright © 2013 Elsevier Inc. All rights reserved.

Cranio-cervical posture: a factor in the development and function of the dentofacial structures.

PubMed

Solow, Beni; Sandham, Andrew

2002-10-01

Many practitioners will recognize that subjects with a large mandibular plane inclination are characterized by an extended head posture and a forward inclined cervical column, i.e. an extended cranio-cervical posture. It is also typical that subjects with a short-face morphology often carry their heads somewhat lowered, and have a markedly backward-curved upper cervical spine, i.e. cervical lordosis. The aim of the paper is to link together the findings of a series of studies that attempt to clarify this relationship, and bring into focus cranio-cervical posture, which is a functional factor that seems to be involved in many clinical orthodontic problems. To provide a background for the article, the concept of standardized posture of the head and the cervical column is developed, and procedures for recording this posture, as well as categories of cephalometric variables that express the different postural relationships, are described. Findings that relate cranio-cervical posture to upper airway obstruction, to craniofacial morphology, and to malocclusion are surveyed, and a post-natal developmental mechanism that explains the findings and leads to further questions is discussed. Recent findings of a relationship between extended cranio-cervical posture and signs and symptoms of temporomandibular disorders further emphasize the biological importance of this functional parameter.

QTLTableMiner++: semantic mining of QTL tables in scientific articles.

PubMed

Singh, Gurnoor; Kuzniar, Arnold; van Mulligen, Erik M; Gavai, Anand; Bachem, Christian W; Visser, Richard G F; Finkers, Richard

2018-05-25

A quantitative trait locus (QTL) is a genomic region that correlates with a phenotype. Most of the experimental information about QTL mapping studies is described in tables of scientific publications. Traditional text mining techniques aim to extract information from unstructured text rather than from tables. We present QTLTableMiner ++ (QTM), a table mining tool that extracts and semantically annotates QTL information buried in (heterogeneous) tables of plant science literature. QTM is a command line tool written in the Java programming language. This tool takes scientific articles from the Europe PMC repository as input, extracts QTL tables using keyword matching and ontology-based concept identification. The tables are further normalized using rules derived from table properties such as captions, column headers and table footers. Furthermore, table columns are classified into three categories namely column descriptors, properties and values based on column headers and data types of cell entries. Abbreviations found in the tables are expanded using the Schwartz and Hearst algorithm. Finally, the content of QTL tables is semantically enriched with domain-specific ontologies (e.g. Crop Ontology, Plant Ontology and Trait Ontology) using the Apache Solr search platform and the results are stored in a relational database and a text file. The performance of the QTM tool was assessed by precision and recall based on the information retrieved from two manually annotated corpora of open access articles, i.e. QTL mapping studies in tomato (Solanum lycopersicum) and in potato (S. tuberosum). In summary, QTM detected QTL statements in tomato with 74.53% precision and 92.56% recall and in potato with 82.82% precision and 98.94% recall. QTM is a unique tool that aids in providing QTL information in machine-readable and semantically interoperable formats.

The influence of a fire-induced convection column on radiological fallout patterns

Treesearch

A. Broido; A.W. McMasters

1959-01-01

Since no nuclear devices have been detonated by the United States under conditions leading to both mass fires and radiological fallout, a theoretical and small-scale experimental study was undertaken to see if fire-induced convection columns could significantly affect fallout patterns. Experiments were conducted in a 6- by 6-foot low-velocity wind tunnel using full-...

19 CFR 10.253 - Articles eligible for preferential treatment.

Code of Federal Regulations, 2013 CFR

2013-04-01

...) Footwear not designated on December 4, 1991, as eligible articles for the purpose of the Generalized System... material which is the product of any country with respect to which HTSUS column 2 rates of duty apply; and... materials produced in an ATPDEA beneficiary country or countries, plus the direct costs of processing...

19 CFR 10.253 - Articles eligible for preferential treatment.

Code of Federal Regulations, 2014 CFR

2014-04-01

...) Footwear not designated on December 4, 1991, as eligible articles for the purpose of the Generalized System... material which is the product of any country with respect to which HTSUS column 2 rates of duty apply; and... materials produced in an ATPDEA beneficiary country or countries, plus the direct costs of processing...

Articles of Faith & Hope for Public Education.

ERIC Educational Resources Information Center

Houston, Paul D.

America's common schools are at a crossroads. This collection of speeches, articles and columns, written by the executive director of the American Association of School Administrators (AASA), between 1994-1997, addresses many of the issues today. The overriding theme is the need to preserve common schools, which are presented as the key instrument…

Speak Out for Children. Winter 1992/1993 through Summer/Fall 1994.

ERIC Educational Resources Information Center

Levy, David L., Ed.; Diamond, Elliott H., Ed.

1993-01-01

"Speak Out for Children" is the quarterly newsletter of the Children's Rights Council (CRC), which is concerned with the healthy development of children of divorced and separated parents. The newsletter consists of feature articles and regular sections and columns. Feature articles of Volume 8, Number 1 are: "The Controversial Truth: Two-Parent…

The Science Teacher: Spring 2008

NASA Astrophysics Data System (ADS)

Long, Steve

2008-06-01

This article reviews chemistry-related articles published between Summer 2007 and February 2008, in The Science Teacher ( TST ). A new TST column addresses safety-with emphases in reviewed articles on chemical hygiene plans, bloodborne pathogens, ionizing radiation, eyewash and shower stations, electrical safety, and chemical management. In addition, activities for teaching about ionic compounds, an inquiry-based lab and card sorting project on freezing point depressions, and a simulation of Rutherford's Gold Foil Experiment are described. Also included is a career focus on a green product chemist. Supplementary JCE articles for these articles and topics are referenced.

Decision making regarding Smith-Petersen vs. pedicle subtraction osteotomy vs. vertebral column resection for spinal deformity.

PubMed

Bridwell, Keith H

2006-09-01

Author experience and literature review. To investigate and discuss decision-making on when to perform a Smith-Petersen osteotomy as opposed to a pedicle subtraction procedure and/or a vertebral column resection. Articles have been published regarding Smith-Petersen osteotomies, pedicle subtraction procedures, and vertebral column resections. Expectations and complications have been reviewed. However, decision-making regarding which of the 3 procedures is most useful for a particular spinal deformity case is not clearly investigated. Discussed in this manuscript is the author's experience and the literature regarding the operative options for a fixed coronal or sagittal deformity. There are roles for Smith-Petersen osteotomy, pedicle subtraction, and vertebral column resection. Each has specific applications and potential complications. As the magnitude of resection increases, the ability to correct deformity improves, but also the risk of complication increases. Therein, an understanding of potential applications and complications is helpful.

Familiarizing Students with the Basics of a Smartphone's Internal Sensors

NASA Astrophysics Data System (ADS)

Countryman, Colleen Lanz

2014-12-01

The Physics Teacher's "iPhysicsLabs" column has been dedicated to the implementation of smartphones in instructional physics labs as data collection devices. In order to understand any data set, however, one should first understand how it is obtained. This concern regarding the inclusion of smartphones in lab activities has arisen in response to the creation of this column1 as well as to a paper in a recent issue of Physics Today.2 The majority of the labs featured in the "iPhysicsLabs" column to date make use of the internal accelerometer, common to nearly all smartphones on the market today. In order to glean meaningful conclusions from their data, students should first understand how the sensor works, as was pointed out in the first article to be featured in that column.3 We attempt to elucidate this "iBlackBox" using a simple ball-and-spring model.

Distillation Column Flooding Predictor

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

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 distillationmore » 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/vapor traffic that produce increased contact area and lead to substantial increases in separation efficiency – which translates to a 10% increase in energy efficiency on a BTU/bbl basis. The Flooding Predictor™ operates on the principle that between five to sixty minutes in advance of a flooding event, certain column variables experience an oscillation, a pre-flood pattern. The pattern recognition system of the Flooding Predictor™ utilizes the mathematical first derivative of certain column variables to identify the column’s pre-flood pattern(s). This pattern is a very brief, highly repeatable, simultaneous movement among the derivative values of certain column variables. While all column variables experience negligible random noise generated from the natural frequency of the process, subtle pre-flood patterns are revealed among sub-sets of the derivative values of column variables as the column approaches its hydraulic limit. The sub-set of column variables that comprise the pre-flood pattern is identified empirically through in a two-step process. First, 2ndpoint’s proprietary off-line analysis tool is used to mine historical data for pre-flood patterns. Second, the column is flood-tested to fine-tune the pattern recognition for commissioning. Then the Flooding Predictor™ is implemented as closed-loop advanced control strategy on the plant’s distributed control system (DCS), thus automating control of the column at its hydraulic limit.« less

Removal of lead(II) by adsorption using treated granular activated carbon: batch and column studies.

PubMed

Goel, Jyotsna; Kadirvelu, Krishna; Rajagopal, Chitra; Kumar Garg, Vinod

2005-10-17

In the present study, a deeper understanding of adsorption behavior of Pb(II) from aqueous systems onto activated carbon and treated activated carbon has been attempted via static and column mode studies under various conditions. It probes mainly two adsorbents that is, activated carbon (AC) and modified activated carbon (AC-S). Characterization of both the adsorbents was one of the key focal areas of the present study. This has shown a clear change or demarcation in the various physical and chemical properties of the modified adsorbent from its precursor activated carbon. Both the adsorbents are subjected to static mode adsorption studies and then after a comparison based on isotherm analysis; more efficient adsorbent is screened for column mode adsorption studies. The lead removal increased for sample of treated carbon. The extent of Pb(II) removal was found to be higher in the treated activated carbon. The aim of carrying out the continuous-flow studies was to assess the effect of various process variables, viz., of bed height, hydraulic loading rate and initial feed concentration on breakthrough time and adsorption capacity. This has helped in ascertaining the practical applicability of the adsorbent. Breakthrough curves were plotted for the adsorption of lead on the adsorbent using continuous-flow column operation by varying different operating parameters like hydraulic loading rate (3.0-10.5 m3/(hm2)), bed height (0.3-0.5 m) and feed concentrations (2.0-6.0 mg/l). At the end, an attempt has also been made to model the data generated from column studies using the empirical relationship based on Bohart-Adams model. This model has provided an objective framework to the subjective interpretation of the adsorption system and the model constant obtained here can be used to achieve the ultimate objective of our study that is, up scaling and designing of adsorption process at the pilot plant scale level. AC-S column regeneration using 0.5 and 1.0M concentration of HNO3 has been investigated. It has shown a regeneration efficiency of 52.0% with 0.5 M HNO3.

Book Order/Inter Library Loan Documentation

DTIC Science & Technology

1992-04-20

BORROWER: SCOTT DAVID OFFICE: DPRA ARTICLE TITLE: LABORATORY STUDY OF THE RELEASE OF PESTICIDES AND PCB MATERIALS TO THE WATER COLUMN DURING... ARTICLE...TECHNICAL INFORMATION CENTER PAGE NO. INTER LIBARY LOAN REPORT BORROWER: SCOTT DAVID OFFICE: DPRA ARTICLE TITLE: LABORATORY STUDY OF THE RELEASE OF...FROM A USER THAT REQUIRES FEWER THAN 15 MINUTES OF A STAFF MEMBER’S TIME TO ANSWER. MAY INCLUDE A RTIC CATALOG SEARCH, VERIFICATION OF INFORMATION IN A

Mechanistic study of lead desorption during the leaching process of ion-absorbed rare earths: pH effect and the column experiment

NASA Astrophysics Data System (ADS)

Xue, Q.; Tang, J., Sr.; Chen, H.

2017-12-01

High concentrations of ammonium sulfate, often used in the in-situ mining process, can result in a decrease of pH in the environment and dissolution of rare earth metals. Ammonium sulfate can also cause desorption of toxic heavy metals, leading to environmental and human health implications. In this study, the desorption behavior and fraction changes of lead in the ion-absorbed rare earth ore were studied using batch desorption experiments and column leaching tests. Results from batch desorption experiments showed that the desorption process of lead included fast and slow stages, and followed an Elovich model well. The desorption rate and the proportion of lead content in the solution to the total lead in the soil were observed to increase with a decrease in the initial pH of the ammonium sulfate solution. The lead in soil included an acid extractable fraction, reducible fraction, oxidizable fraction, and a residual fraction, with the predominant fractions being the reducible and acid extractable fractions. 96% of the extractable fraction in soil were desorbed into solution at pH=3.0, and the content of the reducible fraction was observed to initially increase (when pH>4.0) and then decrease (when pH<4.0) with a decrease in pH. Column leaching tests indicated that the content of lead in the different fractions of soil followed the trend of reducible fraction > oxidizable fraction > acid extractable fraction > residual fraction after the simulating leaching mining process. The change in pH was also found to have a larger influence on the acid extractable and reducible fractions than the other two fractions. The proportion of the extractable fraction being leached was ca. 86%, and the reducible fraction was enriched along the migration direction of the leaching liquid. These results suggest that certain lead fractions may desorb again and contaminate the environment via acid rain, which provides significant information for environmental assessment and remediation after mining process.

On Open Access to Research: The Green, the Gold, and the Public Good

ERIC Educational Resources Information Center

Roach, Audra K.; Gainer, Jesse

2013-01-01

In this column the authors discuss barriers to worldwide open access to peer-reviewed journal articles online and how they might be addressed by literacy scholars. They highlight economic and ethical problems associated with the current subscription-based system for distributing articles (which sometimes works against the ideals of research and…

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

Nash, C.; Williams, M.; Restivo, M.

All prior testing with SuperLig® 639 has been done with the aqueous concentration of LAW at ~5 M [Na+], where the resin sinks, and can be used in a conventional down-flow column orientation. However, the aqueous LAW stream from the Waste Treatment Plant is expected to be ~8 M [Na+]. The resin would float in this higher density liquid, potentially disrupting the ability to achieve a good decontamination due to poor packing of the resin that leads to channeling. Testing was completed with a higher salt concentration in the feed simulant (7.8 M [Na+]) in an engineering-scale apparatus with twomore » columns, each containing ~0.9 L of resin. Testing of this system used a simulant of the LAW solution, and substituted ReO4 - as a surrogate for TcO4 -. Results were then compared using computer modeling. Bench-scale testing was also performed, and examined an unconstrained resin bed, while engineering-scale tests used both constrained and unconstrained beds in a two-column, lead and lag sequential arrangement.« less

The Joule-Thomson coefficient as a criterion for efficient operating conditions in supercritical fluid chromatography.

PubMed

Poe, Donald P; Helmueller, Shawn; Kobany, Stephanie; Feldhacker, Hannah; Kaczmarski, Krzysztof

2017-01-27

When an SFC column is operated in a traditional oven with forced air at low pressures near the critical temperature, severe efficiency losses can occur. The mobile phase cools as it expands along the column, forming axial and radial temperature gradients. In this study we present a simple model based on a virtual fluid to predict the conditions which lead to the onset of efficiency loss. The model shows that the Joule-Thomson coefficient is an important factor leading to efficiency loss in packed columns under forced air conditions. The model was tested experimentally for elution of n-alkylbenzenes on 250×4.6-mm ID columns packed with 5-μm Luna-C18 (fully porous) and Kinetex-C18 (superficially porous) particles at optimum flow rates in a forced air oven at 20-80°C and outlet pressures from 90 to 250bar, with CO 2 mobile phase containing 5, 10 and 20% methanol (v/v). For simplicity, we used a formal J-T coefficient corresponding to the inlet temperature and the outlet pressure to characterize the chromatographic conditions. For 5% methanol, there was no significant loss of efficiency for elution of n-octadecylbenzene as long as the formal J-T coefficient was less than 0.11K/bar for Luna or 0.15K/bar for Kinetex, with minimum reduced plate heights equal to 1.82 and 1.55, respectively, at an average apparent retention factor of approximately 4.0 for both columns. The Kinetex column provided superior efficiency in general, and at 10-20bar lower outlet pressures relative to the Luna column due to the higher thermal conductivity of the packing. Results for 10 and 20% methanol showed similar trends but were less predictable. Copyright © 2016 Elsevier B.V. All rights reserved.

High-throughput NGL electron-beam direct-write lithography system

NASA Astrophysics Data System (ADS)

Parker, N. William; Brodie, Alan D.; McCoy, John H.

2000-07-01

Electron beam lithography systems have historically had low throughput. The only practical solution to this limitation is an approach using many beams writing simultaneously. For single-column multi-beam systems, including projection optics (SCALPELR and PREVAIL) and blanked aperture arrays, throughput and resolution are limited by space-charge effects. Multibeam micro-column (one beam per column) systems are limited by the need for low voltage operation, electrical connection density and fabrication complexities. In this paper, we discuss a new multi-beam concept employing multiple columns each with multiple beams to generate a very large total number of parallel writing beams. This overcomes the limitations of space-charge interactions and low voltage operation. We also discuss a rationale leading to the optimum number of columns and beams per column. Using this approach we show how production throughputs >= 60 wafers per hour can be achieved at CDs

Lead and Antimony Speciation in Shooting Range Soils: Molecular Scale Analysis, Temporal Trends and Mobility

DTIC Science & Technology

2017-11-20

35 Figure 25. Effects of saturation time on Pb concentrations as a function of soil type and column...36 Figure 26. Effects of saturation time on Sb concentrations as a function of soil type and column set (a...representation of the oxygen -terminated full layer termination surface of hematite ( ) (second octahedral layer and those beneath are not shown for clarity) ; (D

Improving Practice through Research.

ERIC Educational Resources Information Center

Rose, Terry L.

1989-01-01

The article discusses the need for communication of research findings involving exceptional individuals, the need for resolution of the research-practice dichotomy, and the types of papers which will appear in the new column. (JDD)

7 CFR 301.32-2 - Regulated articles.

Code of Federal Regulations, 2011 CFR

2011-01-01

.... (a) In the following table, the berry, fruit, nut, or vegetable listed in each row in the left column.... Elaeocarpus angustifolius Blue marbletree; New Guinea quandong Peach. Elaeocarpus grandiflorus Lily of the...

The Talkies: Articles and Illustrations from a Great Fan Magazine 1928-1940.

ERIC Educational Resources Information Center

Griffith, Richard

"Photoplay" Magazine is the source of these articles and photographs, which date from the start of the sound era to the start of World War II. Sections are devoted to stars, living and working in Hollywood, contributions of the production crew to films, trends in motion pictures, and a sample of film fans' favorite columns. (JK)

Language Everywhere. [Compiled from Columns in Three Issues of "Live Wire," February, April, and August 1985.

ERIC Educational Resources Information Center

Live Wire, 1985

1985-01-01

The teaching activities presented in these articles integrate language skills in a variety of ways. The articles describe assignments about (1) using road signs to help students realize the importance of reading the signs they encounter; (2) integrating reading, speech, writing, and art, with pet dragons as the subject; (3) focusing on reading and…

Direct coupling of microbore HPLC columns to MS systems

NASA Technical Reports Server (NTRS)

Mcnair, H. M.

1985-01-01

A detailed investigation using electron microscopy was conducted which examined the conditions of materials used in the construction of stable, high performance microbore liquid chromatography (LC) columns. Small details proved to be important. The effects of temperature on the elution of several homologous series used as probe compounds was examined in reverse phase systems. They showed that accessible temperature changes provide roughly half the increase in solvent strength that would be obtained going from a 100% aqueous to a 100% organic mobile phase, which is sufficient to warrant their use in many analyses requiring the use of gradients. Air circulation temperature control systems provide the easiest means of obtaining rapid, wide range changes in column temperature. However, slow heat transfer from the gas leads to thermal nonuniformity in the column and a decrease in resolution as the temperature program progresses.

Microbial Control News - November 2011

USDA-ARS?s Scientific Manuscript database

This is the first of a column in the Society for Invertebrate Pathology Newsletter. Entitled "Microbial Control News" this article summarizes regulatory actions in the U.S. and Canada regarding microbial insect pest control agents....

On the radiation beaming of bright X-ray pulsars and constraints on neutron star mass-radius relation

NASA Astrophysics Data System (ADS)

Mushtukov, Alexander A.; Verhagen, Patrick A.; Tsygankov, Sergey S.; van der Klis, Michiel; Lutovinov, Alexander A.; Larchenkova, Tatiana I.

2018-03-01

The luminosity of accreting magnetized neutron stars can largely exceed the Eddington value due to appearance of accretion columns. The height of the columns can be comparable to the neutron star radius. The columns produce the X-rays detected by the observer directly and illuminate the stellar surface, which reprocesses the X-rays and causes additional component of the observed flux. The geometry of the column and the illuminated part of the surface determine the radiation beaming. Curved space-time affects the angular flux distribution. We construct a simple model of the beam patterns formed by direct and reflected flux from the column. We take into account the possibility of appearance of accretion columns, whose height is comparable to the neutron star radius. We argue that depending on the compactness of the star, the flux from the column can be either strongly amplified due to gravitational lensing, or significantly reduced due to column eclipse by the star. The eclipses of high accretion columns result in specific features in pulse profiles. Their detection can put constraints on the neutron star radius. We speculate that column eclipses are observed in X-ray pulsar V 0332+53, leading us to the conclusion of large neutron star radius in this system (˜15 km if M ˜ 1.4 M⊙). We point out that the beam pattern can be strongly affected by scattering in the accretion channel at high luminosity, which has to be taken into account in the models reproducing the pulse profiles.

Comparison of three different C18 HPLC columns with different particle sizes for the optimization of aflatoxins analysis.

PubMed

Medina, A; Magan, N

2012-03-15

In this work we compared the performance of chromatography columns with particles of 5 and 3 μm with the new 2.7 μm solid core particles for the analysis of aflatoxins B1, G1, B2, and G2 using trifluoroacetic acid pre-column derivatization. Three different columns have been used and chromatographic parameters as retention time, resolution, limit of detection (LOD), limit of quantification (LOQ) were obtained from all of them and compared. The results show that comparing with the traditional columns, shorter columns (100 mm × 4.6 mm) with the new solid core particles are suitable for the analysis of these mycotoxins and allowed the reduction of the analysis time by 45.5% and 33.3% with respect to columns with particle size 5 μm (150 mm × 4.6 mm) and 3 μm (150 mm × 4.6 mm) respectively, without any detrimental effect on performance. This leads to the reduction of the analysis costs by saving on organic solvents and increasing the total number of analyses per day. The capability of these columns for analyzing samples, in different culture media, was assessed by analyzing different samples from: yeasts extract sucrose medium, corn meal agar medium and fresh hazelnut media. Copyright © 2012 Elsevier B.V. All rights reserved.

Mitigation of Liquefaction in Sandy Soils Using Stone Columns

NASA Astrophysics Data System (ADS)

Selcuk, Levent; Kayabalı, Kamil

2010-05-01

Soil liquefaction is one of the leading causes of earthquake-induced damage to structures. Soil improvement methods provide effective solutions to reduce the risk of soil liquefaction. Thus, soil ground treatments are applied using various techniques. However, except for a few ground treatment methods, they generally require a high cost and a lot of time. Especially in order to prevent the risk of soil liquefaction, stone columns conctructed by vibro-systems (vibro-compaction, vibro-replacement) are one of the traditional geotechnical methods. The construction of stone columns not only enhances the ability of clean sand to drain excess pore water during an earthquake, but also increases the relative density of the soil. Thus, this application prevents the development of the excess pore water pressure in sand during earthquakes and keeps the pore pressure ratio below a certain value. This paper presents the stone column methods used against soil liquefaction in detail. At this stage, (a) the performances of the stone columns were investigated in different spacing and diameters of columns during past earthquakes, (b) recent studies about design and field applications of stone columns were presented, and (c) a new design method considering the relative density of soil and the capacity of drenage of columns were explained in sandy soil. Furthermore, with this new method, earthquake performances of the stone columns constructed at different areas were investigated before the 1989 Loma Prieta and the 1994 Northbridge earthquakes, as case histories of field applications, and design charts were compiled for suitable spacing and diameters of stone columns with consideration to the different sandy soil parameters and earhquake conditions. Key Words: Soil improvement, stone column, excess pore water pressure

Surface micro-structuring of silicon by excimer-laser irradiation in reactive atmospheres

NASA Astrophysics Data System (ADS)

Pedraza, A. J.; Fowlkes, J. D.; Jesse, S.; Mao, C.; Lowndes, D. H.

2000-12-01

The formation mechanisms of cones and columns by pulsed-laser irradiation in reactive atmospheres were studied using scanning electron microscopy and profilometry. Deep etching takes place in SF6- and O2- rich atmospheres and consequently, silicon-containing molecules and clusters are released. Transport of silicon from the etched/ablated regions to the tip of columns and cones and to the side of the cones is required because both structures, columns and cones, protrude above the initial surface. The laser-induced micro-structure is influenced not only by the nature but also by the partial pressure of the reactive gas in the atmosphere. Irradiation in Ar following cone formation in SF6 produced no additional growth but rather melting and resolidification. Subsequent irradiation using again a SF6 atmosphere lead to cone restructuring and growth resumption. Thus the effects of etching plus re-deposition that produce column/cone formation and growth are clearly separated from the effects of just melting. On the other hand, irradiation continued in air after first performed in SF6 resulted in: (a) an intense etching of the cones and a tendency to transform them into columns; (b) growth of new columns on top of the existing cones and (c) filamentary nano-structures coating the sides of the columns and cones.

Simulation of elution profiles in liquid chromatography - II: Investigation of injection volume overload under gradient elution conditions applied to second dimension separations in two-dimensional liquid chromatography.

PubMed

Stoll, Dwight R; Sajulga, Ray W; Voigt, Bryan N; Larson, Eli J; Jeong, Lena N; Rutan, Sarah C

2017-11-10

An important research direction in the continued development of two-dimensional liquid chromatography (2D-LC) is to improve the detection sensitivity of the method. This is especially important in applications where injection of large volumes of effluent from the first dimension ( 1 D) column into the second dimension ( 2 D) column leads to severe 2 D peak broadening and peak shape distortion. For example, this is common when coupling two reversed-phase columns and the organic solvent content of the 1 D mobile phase overwhelms the 2 D column with each injection of 1 D effluent, leading to low resolution in the second dimension. In a previous study we validated a simulation approach based on the Craig distribution model and adapted from the work of Czok and Guiochon [1] that enabled accurate simulation of simple isocratic and gradient separations with very small injection volumes, and isocratic separations with mismatched injection and mobile phase solvents [2]. In the present study we have extended this simulation approach to simulate separations relevant to 2D-LC. Specifically, we have focused on simulating 2 D separations where gradient elution conditions are used, there is mismatch between the sample solvent and the starting point in the gradient elution program, injection volumes approach or even exceed the dead volume of the 2 D column, and the extent of sample loop filling is varied. To validate this simulation we have compared results from simulations and experiments for 101 different conditions, including variation in injection volume (0.4-80μL), loop filling level (25-100%), and degree of mismatch between sample organic solvent and the starting point in the gradient elution program (-20 to +20% ACN). We find that that the simulation is accurate enough (median errors in retention time and peak width of -1.0 and -4.9%, without corrections for extra-column dispersion) to be useful in guiding optimization of 2D-LC separations. However, this requires that real injection profiles obtained from 2D-LC interface valves are used to simulate the introduction of samples into the 2 D column. These profiles are highly asymmetric - simulation using simple rectangular pulses leads to peak widths that are far too narrow under many conditions. We believe the simulation approach developed here will be useful for addressing practical questions in the development of 2D-LC methods. Copyright © 2017 Elsevier B.V. All rights reserved.

Recent trends in ultra-fast HPLC: new generation superficially porous silica columns.

PubMed

Ali, Imran; Al-Othman, Zeid A; Nagae, Norikaju; Gaitonde, Vinay D; Dutta, Kamlesh K

2012-12-01

New generation columns, i.e. packed with superficially porous silica particles are available as trade names with following manufacturers: Halo, Ascentis Express, Proshell 120, Kinetex, Accucore, Sunshell, and Nucleoshell. These provide ultra-fast HPLC separations for a variety of compounds with moderate sample loading capacity and low back pressure. Chemistries of these columns are C(8), C(18), RP-Amide, hydrophilic interaction liquid chromatography, penta fluorophenyl (PFP), F5, and RP-aqua. Normally, the silica gel particles are of 2.7 and 1.7 μm as total and inner solid core diameters, respectively, with 0.5-μm-thick of outer porous layer having 90 Å pore sizes and 150 m(2)/g surface area. This article describes these new generation columns with special emphasis on their textures and chemistries, separations, optimization, and comparison (inter and intra stationary phases). Besides, future perspectives have also been discussed. © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Case Study: Testing with Case Studies

ERIC Educational Resources Information Center

Herreid, Clyde Freeman

2015-01-01

This column provides original articles on innovations in case study teaching, assessment of the method, as well as case studies with teaching notes. This month's issue discusses using case studies to test for knowledge or lessons learned.

Author Correction: Competition between crystal and fibril formation in molecular mutations of amyloidogenic peptides.

PubMed

Reynolds, Nicholas P; Adamcik, Jozef; Berryman, Joshua T; Handschin, Stephan; Zanjani, Ali Asghar Hakami; Li, Wen; Liu, Kun; Zhang, Afang; Mezzenga, Raffaele

2017-12-20

The original version of this article contained an error in Fig. 5c. The label for the back series of columns was incorrectly given as '1.5 mM pH 2', rather than the correct '1.5 mM pH 7'. This has now been corrected in both the PDF and HTML versions of the article.

A narrow open tubular column for high efficiency liquid chromatographic separation.

PubMed

Chen, Huang; Yang, Yu; Qiao, Zhenzhen; Xiang, Piliang; Ren, Jiangtao; Meng, Yunzhu; Zhang, Kaiqi; Juan Lu, Joann; Liu, Shaorong

2018-04-30

We report a great feature of open tubular liquid chromatography when it is run using an extremely narrow (e.g., 2 μm inner diameter) open tubular column: more than 10 million plates per meter can be achieved in less than 10 min and under an elution pressure of ca. 20 bar. The column is coated with octadecylsilane and both isocratic and gradient separations are performed. We reveal a focusing effect that may be used to interpret the efficiency enhancement. We also demonstrate the feasibility of using this technique for separating complex peptide samples. This high-resolution and fast separation technique is promising and can lead to a powerful tool for trace sample analysis.

Evaluation of punching shear strength of flat slabs supported on rectangular columns

NASA Astrophysics Data System (ADS)

Filatov, Valery

2018-03-01

The article presents the methodology and results of an analytical study of structural parameters influence on the value of punching force for the joint of columns and flat reinforced concrete slab. This design solution is typical for monolithic reinforced concrete girderless frames, which have a wide application in the construction of high-rise buildings. As the results of earlier studies show the punching shear strength of slabs at rectangular columns can be lower than at square columns with a similar length of the control perimeter. The influence of two structural parameters on the punching strength of the plate is investigated - the ratio of the side of the column cross-section to the effective depth of slab C/d and the ratio of the sides of the rectangular column Cmax/Cmin. According to the results of the study, graphs of reduction the control perimeter depending on the structural parameters are presented for columns square and rectangular cross-sections. Comparison of results obtained by proposed approach and MC2010 simplified method are shown, that proposed approach gives a more conservative estimate of the influence of the structural parameters. A significant influence of the considered structural parameters on punching shear strength of reinforced concrete slabs is confirmed by the results of experimental studies. The results of the study confirm the necessity of taking into account the considered structural parameters when calculating the punching shear strength of flat reinforced concrete slabs and further development of code design methods.

Flow morphologies after oblique shock acceelration of a cylindrical density interface

NASA Astrophysics Data System (ADS)

Wayne, Patrick; Simons, Dylan; Olmstead, Dell; Truman, C. Randall; Vorobieff, Peter; Kumar, Sanjay

2015-11-01

We present an experimental study of instabilities developing after an oblique shock interaction with a heavy gas column. The heavy gas in our experiments is sulfur hexafluoride infused with 11% acetone by mass. A misalignment of the pressure and density gradients results in three-dimensional vorticity deposition on the gaseous interface, dtriggering the onset of Richtmyer-Meshkov instability (RMI). Shortly thereafter, other instabilities develop along the interface, including a shear-driven instability that presents itself on the leading (with respect to the shock) and trailing edges of the column. This leads to the development of rows of co-rotating ``cat's eye'' vortices, characteristic of Kelvin-Helmholtz instability (KHI). Characteristics of the KHI, such as growth rate and wavelength, depend on several factors including the Mach number of the shock, the shock tube angle of inclination α (equal to the angle between the axis of the column and the plane of the shock), and the Atwood number. This work is supported by the US National Nuclear Security Agency (NNSA) via grant DE-NA0002913.

Water Column Correction for Coral Reef Studies by Remote Sensing

PubMed Central

Zoffoli, Maria Laura; Frouin, Robert; Kampel, Milton

2014-01-01

Human activity and natural climate trends constitute a major threat to coral reefs worldwide. Models predict a significant reduction in reef spatial extension together with a decline in biodiversity in the relatively near future. In this context, monitoring programs to detect changes in reef ecosystems are essential. In recent years, coral reef mapping using remote sensing data has benefited from instruments with better resolution and computational advances in storage and processing capabilities. However, the water column represents an additional complexity when extracting information from submerged substrates by remote sensing that demands a correction of its effect. In this article, the basic concepts of bottom substrate remote sensing and water column interference are presented. A compendium of methodologies developed to reduce water column effects in coral ecosystems studied by remote sensing that include their salient features, advantages and drawbacks is provided. Finally, algorithms to retrieve the bottom reflectance are applied to simulated data and actual remote sensing imagery and their performance is compared. The available methods are not able to completely eliminate the water column effect, but they can minimize its influence. Choosing the best method depends on the marine environment, available input data and desired outcome or scientific application. PMID:25215941

Water column correction for coral reef studies by remote sensing.

PubMed

Zoffoli, Maria Laura; Frouin, Robert; Kampel, Milton

2014-09-11

Human activity and natural climate trends constitute a major threat to coral reefs worldwide. Models predict a significant reduction in reef spatial extension together with a decline in biodiversity in the relatively near future. In this context, monitoring programs to detect changes in reef ecosystems are essential. In recent years, coral reef mapping using remote sensing data has benefited from instruments with better resolution and computational advances in storage and processing capabilities. However, the water column represents an additional complexity when extracting information from submerged substrates by remote sensing that demands a correction of its effect. In this article, the basic concepts of bottom substrate remote sensing and water column interference are presented. A compendium of methodologies developed to reduce water column effects in coral ecosystems studied by remote sensing that include their salient features, advantages and drawbacks is provided. Finally, algorithms to retrieve the bottom reflectance are applied to simulated data and actual remote sensing imagery and their performance is compared. The available methods are not able to completely eliminate the water column effect, but they can minimize its influence. Choosing the best method depends on the marine environment, available input data and desired outcome or scientific application.

Mechanistic study of lead desorption during the leaching process of ion-absorbed rare earths: pH effect and the column experiment.

PubMed

Tang, Jie; Xue, Qiang; Chen, Honghan; Li, Wenting

2017-05-01

High concentrations of ammonium sulfate, often used in the in situ mining process, can result in a decrease of pH in the environment and dissolution of rare earth metals. Ammonium sulfate can also cause desorption of toxic heavy metals, leading to environmental and human health implications. In this study, the desorption behavior and fraction changes of lead in the ion-absorbed rare earth ore were studied using batch desorption experiments and column leaching tests. Results from batch desorption experiments showed that the desorption process of lead included fast and slow stages and followed an Elovich model well. The desorption rate and the proportion of lead content in the solution to the total lead in the soil were observed to increase with a decrease in the initial pH of the ammonium sulfate solution. The lead in soil included an acid-extractable fraction, reducible fraction, oxidizable fraction, and a residual fraction, with the predominant fractions being the reducible and acid-extractable fractions. Ninety-six percent of the extractable fraction in soil was desorbed into solution at pH = 3.0, and the content of the reducible fraction was observed to initially increase (when pH >4.0) and then decrease (when pH <4.0) with a decrease in pH. Column leaching tests indicated that the content of lead in the different fractions of soil followed the trend of reducible fraction > oxidizable fraction > acid-extractable fraction > residual fraction after the simulating leaching mining process. The change in pH was also found to have a larger influence on the acid-extractable and reducible fractions than the other two fractions. The proportion of the extractable fraction being leached was ca. 86%, and the reducible fraction was enriched along the migration direction of the leaching liquid. These results suggest that certain lead fractions may desorb again and contaminate the environment via acid rain, which provides significant information for environmental assessment and remediation after mining process. Graphical abstract ᅟ.

Putting Words in Their Mouth: Writing Dialogue for Case Studies

ERIC Educational Resources Information Center

Herreid, Clyde Freeman

2018-01-01

This column provides original articles on innovations in case study teaching, assessment of the method, as well as case studies with teaching notes. This issue discusses dialogue writing guidelines most relevant to case writing.

Preparation of open tubular capillary columns by in situ ring-opening polymerization and their applications in cLC-MS/MS analysis of tryptic digest.

PubMed

Wang, Hongwei; Yao, Yating; Li, Ya; Ma, Shujuan; Peng, Xiaojun; Ou, Junjie; Ye, Mingliang

2017-08-01

An open tubular (OT) column (25 μm i.d.) was prepared by in situ ring-opening polymerization of octaglycidyldimethylsilyl polyhedral oligomeric silsesquioxanes (POSS-epoxy) with 4-aminophenyl disulfide (APDS) in a binary porogenic system of ethanol/H 2 O. It was found that porogenic composition played an important role in the formation of OT stationary phases. The ratio of ethanol/H 2 O at 6/1 (v/v) would lead to the fabrication of hybrid monoliths, while the ratio of ethanol/H 2 O at 13/1 (v/v) would result in the synthesis of OT phases. In addition, the effects of precursor content and reaction duration on the thickness of OT stationary phases were investigated. Either lower precursor content or shorter reaction duration would produce thinner layer of OT column. The repeatability of OT columns was evaluated through relative standard deviation (RSD%) with benzene as the analyte. The run-to-run, column-to-column and batch-to-batch repeatabilities were 1.7%, 4.8% and 5.6%, respectively, exhibiting satisfactory repeatability of the OT column. Then tryptic digest of mouse liver proteins was used to evaluate the performance of the resulting OT columns (25 μm i.d. × 2.5 m in length) by cLC-MS/MS analysis, demonstrating their potential in proteome analysis. Copyright © 2017 Elsevier B.V. All rights reserved.

Size Exclusion Chromatography Studies of the Initial Self-Association Steps of Chicken Egg White Lysozyme Nucleation

NASA Technical Reports Server (NTRS)

Ewing, Felecia; Donovan, David; Pusey, Marc

2000-01-01

Nucleation is one of the least understood aspects of crystallogenesis. In the case of macromolecule nucleation, this understanding is further hampered by uncertainty over what precisely is being discussed. We define the process of solute self-association (aggregation, oligomerization, interaction, clustering, etc.) whereby n-mers (n > or = 2) having a crystallographic or nascent crystallographic arrangement leading to the critical nucleus reversibly form in the solution, to be part of the nucleation process. This reversible self-association process is a fundamental part of the nucleation process, and occurs as a function of the solute concentration. In the case of chicken egg white lysozyme, a considerable body of experimental evidence leads us to the conclusion that it also forms the crystal growth units. Size exclusion chromatography is a simple and direct method for determining the equilibrium constants for the self-association process. A Pharmacia FPLC system was used to provide accurate solution flow rates. The column, injection valve, and sample loop were all mounted within a temperature-controlled chamber. Chromatographically re-purified lysozyme was first dialyzed against the column equilibration buffer, with injection onto the column after several hours pre-incubation at the running temperature. Preliminary experiments, were carried out using a Toyopearl HW-50F column (1 x 50cm), equilibrated with 0.1 M sodium acetate, 5% sodium chloride, pH 4.6, at 15C. Protein concentrations from 0.1 to 4 mg/ml were employed (C(sub sat) = 1.2 mg/ml). The data from several different protein preparations consistently shows a progressively decreasing elution volume with increasing protein concentration, indicating that reversible self-association is occurring. The dotted line indicates the monomeric lysozyme elution volume. However, lysozyme interacts with the column matrix in these experiments, which complicates data analysis.Accordingly, we are testing silica-based HPLC columns in an effort to eliminate this problem and substantially reduce the column volume and experimental run time. The results and data analysis from these and subsequent experiments will be presented.

[Analysis of the articles published in Chinese Journal of Applied Physiology between 2000 and 2006].

PubMed

Wang, Wei-Qiu; Pang, Xiang-Juan

2008-08-01

To analyze the characteristics of publications of Chinese Journal of Applied Physiology between 2000 and 2006, evaluate the academic level and the popularity of the issues, and supplying an evidence for the journal reform. With CNKI and manpower search, by use of literature metrology, a comprehensive analysis of the publications of Chinese Journal of Applied Physiology between 2000 and 2006 was made. The number of articles published form 2000 to 2006 in Chinese Journal of Applied Physiology was 968, The average number of each issue is 34.57, the average page of each article is 3.11, in the columns, the article about original articles was top of rank (66.22% of the total). In the quotation, the quotation increase year by year (100% in 2004-2006), the number of English quotation is very more (76.52% in average). In the time lag, the longest is 510 days, the shortest if 60 days, the average is 196.51 days. In the fund support, the level is increase by fund support, the article number by fund support is increase too, It is 97 in 2005. In the authors' professional positions and academic degrees, the authors' level is more and more higher. In the authors column, Beijing's author is the top of rank, has 162 persons (16.74% of the total). The Chinese Journal of Applied Physiology has published high quality articles. It is the one of the most important information resource for the physiological research and the most important medical journal.

Modeling non-stationary, non-axisymmetric heat patterns in DIII-D tokamak

DOE PAGES

Ciro, D.; Evans, T. E.; Caldas, I. L.

2016-10-27

Non-axisymmetric stationary magnetic perturbations lead to the formation of homoclinic tangles near the divertor magnetic saddle in tokamak discharges. These tangles intersect the divertor plates in static helical structures that delimit the regions reached by open magnetic field lines reaching the plasma column and leading the charged particles to the strike surfaces by parallel transport. In this article we introduce a non-axisymmetric rotating magnetic perturbation to model the time evolution of the three-dimensional magnetic field of a singlenull DIII-D tokamak discharge developing a rotating tearing mode. The non-axiymmetric field is modeled using the magnetic signals to adjust the phases andmore » currents of a set of internal filamentary currents that approximate the magnetic field in the plasma edge region. The stable and unstable manifolds of the asymmetric magnetic saddle are obtained through an adaptive calculation providing the cuts at a given poloidal plane and the strike surfaces. Lastly, for the modeled shot, the experimental heat pattern and its time development are well described by the rotating unstable manifold, indicating the emergence of homoclinic lobes in a rotating frame due to the plasma instabilities.« less

Modeling non-stationary, non-axisymmetric heat patterns in DIII-D tokamak

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

Ciro, D.; Evans, T. E.; Caldas, I. L.

Non-axisymmetric stationary magnetic perturbations lead to the formation of homoclinic tangles near the divertor magnetic saddle in tokamak discharges. These tangles intersect the divertor plates in static helical structures that delimit the regions reached by open magnetic field lines reaching the plasma column and leading the charged particles to the strike surfaces by parallel transport. In this article we introduce a non-axisymmetric rotating magnetic perturbation to model the time evolution of the three-dimensional magnetic field of a singlenull DIII-D tokamak discharge developing a rotating tearing mode. The non-axiymmetric field is modeled using the magnetic signals to adjust the phases andmore » currents of a set of internal filamentary currents that approximate the magnetic field in the plasma edge region. The stable and unstable manifolds of the asymmetric magnetic saddle are obtained through an adaptive calculation providing the cuts at a given poloidal plane and the strike surfaces. Lastly, for the modeled shot, the experimental heat pattern and its time development are well described by the rotating unstable manifold, indicating the emergence of homoclinic lobes in a rotating frame due to the plasma instabilities.« less

Interfacial stability of CoSi2/Si structures grown by molecular beam epitaxy

NASA Technical Reports Server (NTRS)

George, T.; Fathauer, R. W.

1992-01-01

The stability of CoSi2/Si interfaces was examined in this study using columnar silicide structures grown on (111) Si substrates. In the first set of experiments, Co and Si were codeposited using MBE at 800 C and the resulting columnar silicide layer was capped by epitaxial Si. Deposition of Co on the surface of the Si capping layer at 800 C results in the growth of the buried silicide columns. The buried columns grow by subsurface diffusion of the deposited Co, suppressing the formation of surface islands of CoSi2. The column sidewalls appear to be less stable than the top and bottom interfaces, resulting in preferential lateral growth and ultimately in the coalescence of the columns to form a continuous buried CoSi2 layer. In the second set of experiments, annealing of a 250 nm-thick buried columnar layer at 1000 C under a 100 nm-thick Si capping layer results in the formation of a surface layer of CoSi2 with a reduction in the sizes of the CoSi2 columns. For a sample having a thicker Si capping layer the annealing leads to Ostwald ripening producing buried equiaxed columns. The high CoSi2/Si interfacial strain could provide the driving force for the observed behavior of the buried columns under high-temperature annealing.

International trends in health science librarianship part 14: East Africa (Kenya, Uganda, Rwanda).

PubMed

Gathoni, Nasra; Kamau, Nancy; Nannozi, Judith; Singirankabo, Marcel

2015-06-01

This is the 14th in a series of articles exploring international trends in health science librarianship in the 21st century. This is the second of four articles pertaining to different regions in the African continent. The present issue focuses on countries in East Africa (Kenya, Uganda and Rwanda). The next feature column will investigate trends in West Africa. JM. © 2015 Health Libraries Group.

International trends in health science librarianship part 15: West Africa (Ghana, Nigeria, Senegal).

PubMed

Sulemani, Solomon Bayugo; Afarikumah, Ebenezer; Aggrey, Samuel Bentil; Ajuwon, Grace A; Diallo, Ousmane

2015-09-01

This is the 15th in a series of articles exploring international trends in health science librarianship in the 21st century. It is the third of four articles pertaining to different regions in the African continent. The present issue focuses on countries in West Africa (Ghana, Nigeria and Senegal). The next feature column will investigate trends in North Africa. JM. © 2015 Health Libraries Group.

[Erratum] The cnidarian origin of the proto-oncogenes NF-κB/STAT and WNT-like oncogenic pathway drives the ctenophores (Review).

PubMed

Sinkovics, Joseph G

2017-01-01

After the publication of the article, the author noted that there was an error on page 1212, right column, paragraph entitled 'Virus carrier algal symbionts'. The word Hydra virilis should be written as Hydra viridis/viridissima. [the original article was published in the International Journal of Oncology 47: 1211-1229, 2015; DOI: 10.3892/ijo.2015.3102].

The influence of synoptic weather regimes on UK air quality: regional model studies of tropospheric column NO2

NASA Astrophysics Data System (ADS)

Pope, R. J.; Savage, N. H.; Chipperfield, M. P.; Ordóñez, C.; Neal, L. S.

2015-10-01

Synoptic meteorology can have a significant influence on UK air quality. Cyclonic conditions lead to the dispersion of air pollutants away from source regions, while anticyclonic conditions lead to their accumulation over source regions. Meteorology also modifies atmospheric chemistry processes such as photolysis and wet deposition. Previous studies have shown a relationship between observed satellite tropospheric column NO2 and synoptic meteorology in different seasons. Here, we test whether the UK Met Office Air Quality in the Unified Model (AQUM) can reproduce these observations and then use the model to explore the relative importance of various factors. We show that AQUM successfully captures the observed relationships when sampled under the Lamb weather types, an objective classification of midday UK circulation patterns. By using a range of idealized NOx-like tracers with different e-folding lifetimes, we show that under different synoptic regimes the NO2 lifetime in AQUM is approximately 6 h in summer and 12 h in winter. The longer lifetime can explain why synoptic spatial tropospheric column NO2 variations are more significant in winter compared to summer, due to less NO2 photochemical loss. We also show that cyclonic conditions have more seasonality in tropospheric column NO2 than anticyclonic conditions as they result in more extreme spatial departures from the wintertime seasonal average. Within a season (summer or winter) under different synoptic regimes, a large proportion of the spatial pattern in the UK tropospheric column NO2 field can be explained by the idealized model tracers, showing that transport is an important factor in governing the variability of UK air quality on seasonal synoptic timescales.

Labs: 1987.

ERIC Educational Resources Information Center

Igelsrud, Don, Ed.

1988-01-01

This article presents a variety of topics discussed in this column and at a biology teachers' workshop concerning the quality and value of lab techniques used for teaching high school biology. Topics included are Drosophila salivary glands, sea urchins, innovations, dyes and networking. (CW)

Regeneration of Iron-based Adsorptive Media Used for Removing Arsenic from Groundwater

EPA Science Inventory

The journal article will describe batch and column regeneration tests and results that were conducted on six exhausted iron media products to determine whether an iron based media can be successfully regenerated and reused.

A ten year summary of concurrent ambient water column and sediment toxicity tests in the Chesapeake Bay watershed: 1990-1999.

PubMed

Hall, Lenwood W; Anderson, Ronald D; Alden, Raymond W

2002-06-01

The goal of this study was to identify the relative toxicity of ambient areas in the Chesapeake Bay watershed by using a suite of concurrent water column and sediment toxicity tests at seventy-five ambient stations in 20 Chesapeake Bay rivers from 1990 through 1999. Spatial and temporal variability was examined at selected locations throughout the 10 yr study. Inorganic and organic contaminants were evaluated in ambient water and sediment concurrently with water column and sediment tests to assess possible causes of toxicity although absolute causality can not be established. Multivariate statistical analysis was used to develop a multiple endpoint toxicity index (TOX-INDEX) at each station for both water column and sediment toxicity data. Water column tests from the 10 yr testing period showed that 49% of the time, some degree of toxicity was reported. The most toxic sites based on water column results were located in urbanized areas such as the Anacostia River, Elizabeth River and the Middle River. Water quality criteria for copper, lead, mercury, nickel and zinc were exceeded at one or more of these sites. Water column toxicity was also reported in localized areas of the South and Chester Rivers. Both spatial and temporal variability was reported from the suite of water column toxicity tests. Some degree of sediment toxicity was reported from 62% of the tests conducted during the ten year period. The Elizabeth River and Baltimore Harbor stations were reported as the most toxic areas based on sediment results. Sediment toxicity guidelines were exceeded for one or more of the following metals at these two locations: arsenic, cadmium, chromium, copper, lead, nickel and zinc. At the Elizabeth River stations nine of sixteen semi-volatile organics and two of seven pesticides measured exceeded the ER-M values in 1990. Ambient sediment toxicity tests in the Elizabeth River in 1996 showed reduced toxicity. Various semi-volatile organics exceeded the ER-M values at a number of Baltimore Harbor sites; pyrene and dibenzo(a,h)anthracene were particularly high at one of the stations (Northwest Harbor). Localized sediment toxicity was also reported in the Chester, James, Magothy, Rappahannock, and Potomac Rivers but the link with contaminants was not determined. Both spatial and temporal variability was less for sediment toxicity data when compared with water column toxicity data. A comparison of water column and sediment toxicity data for the various stations over the 10 yr study showed that approximately half the time agreement occurred (either both suite of tests showed toxicity or neither suite of tests showed toxicity).

Education and learning: what's on the horizon?

PubMed

Pilcher, Jobeth

2014-01-01

Numerous organizations have called for significant changes in education for health care professionals. The call has included the need to incorporate evidence-based as well as innovative strategies. Previous articles in this column have focused primarily on evidence-based teaching strategies, including concept mapping, brain-based learning strategies, methods of competency assessment, and so forth. This article shifts the focus to new ways of thinking about knowledge and education. The article will also introduce evolving, innovative, less commonly used learning strategies and provide a peek into the future of learning.

Biomechanics of metastatic disease in the vertebral column.

PubMed

Whyne, Cari M

2014-06-01

Metastatic disease in the vertebral column compromises the structural stability of the spine leading to increased risk of fracture. The complex patterns of osteolytic and osteoblastic disease within the bony spine have motivated a multimodal approach to better characterize the biomechanics of tumor-involved bone. This review presents our current understanding of the biomechanical behavior of metastatically involved vertebrae, and experimental and computational image-based approaches that have been employed to quantify structural integrity in preclinical models with translation to clinical data sets.

Physical conditions in CaFe interstellar clouds

NASA Astrophysics Data System (ADS)

Gnaciński, P.; Krogulec, M.

2008-01-01

Interstellar clouds that exhibit strong Ca I and Fe I lines are called CaFe clouds. Ionisation equilibrium equations were used to model the column densities of Ca II, Ca I, K I, Na I, Fe I and Ti II in CaFe clouds. We find that the chemical composition of CaFe clouds is solar and that there is no depletion into dust grains. CaFe clouds have high electron densities, n_e≈1 cm-3, that lead to high column densities of neutral Ca and Fe.

Investigation of the helicon discharge plasma parameters in a hybrid RF plasma system

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

Aleksandrov, A. F.; Petrov, A. K., E-mail: alpetrov57@gmail.com; Vavilin, K. V.

2016-03-15

Results of an experimental study of the helicon discharge plasma parameters in a prototype of a hybrid RF plasma system equipped with a solenoidal antenna are described. It is shown that an increase in the external magnetic field leads to the formation of a plasma column and a shift of the maximum ion current along the discharge axis toward the bottom flange of the system. The shape of the plasma column can be controlled via varying the configuration of the magnetic field.

JCE Online 99

NASA Astrophysics Data System (ADS)

Holmes, Jon L.

1999-04-01

As I write this, JCE Online is in the middle of being redesigned to make it a more usable resource. By the time you read this, the typical online page for articles of this Journal will look like Figure 1. The page has five main features:

• the page heading with the global menu bar
• the left-hand navigation bar
• the page menu bar near the top of the page and repeated near the bottom
• the main content region in the middle of the page
• the right-hand column of local navigation links

Controlled irrigation of a structured packing as a method for increasing the efficiency of liquid mixture separation in the distillation column

NASA Astrophysics Data System (ADS)

Pavlenko, A. N.; Zhukov, V. E.; Pecherkin, N. I.; Nazarov, A. D.; Li, X.; Li, H.; Gao, X.; Sui, H.

2017-09-01

The use of modern structured packing in the distillation columns allows much more even distribution of the liquid film over the packing surface, but it does not completely solve the problem of uniform distribution of flow parameters over the entire height of the packing. Negative stratification of vapor along the packing height caused by different densities of vapor mixture components and higher temperature in the lower part of the column leads to formation of large-scale maldistributions of temperature and mixture composition over the column cross-section even under the conditions of uniform irrigation of packing with liquid. In these experiments, the idea of compensatory action of liquid distributor on the large-scale maldistribution of mixture composition over the column cross-section was implemented. The experiments were carried out in the distillation column with the diameter of 0.9 m on 10 layers of the Mellapak 350Y packing with the total height of 2.1 m. The mixture of R-21 and R-114 was used as the working mixture. To irrigate the packing, the liquid distributorr with 126 independently controlled solenoid valves overlapping the holes with the diameter of 5 mm, specially designed by the authors, was used. Response of the column to the action of liquid distributor was observed in real time according to the indications of 3 groups of thermometers mounted in 3 different cross-sections of the column. The experiments showed that the minimal correction of the drip point pattern in the controlled liquid distributor can significantly affect the pattern of flow parameter distribution over the cross-section and height of the mass transfer surface and increase separation efficiency of the column within 20%.

Chemometrics applications in biotechnology processes: predicting column integrity and impurity clearance during reuse of chromatography resin.

PubMed

Rathore, Anurag S; Mittal, Shachi; Lute, Scott; Brorson, Kurt

2012-01-01

Separation media, in particular chromatography media, is typically one of the major contributors to the cost of goods for production of a biotechnology therapeutic. To be cost-effective, it is industry practice that media be reused over several cycles before being discarded. The traditional approach for estimating the number of cycles a particular media can be reused for involves performing laboratory scale experiments that monitor column performance and carryover. This dataset is then used to predict the number of cycles the media can be used at manufacturing scale (concurrent validation). Although, well accepted and widely practiced, there are challenges associated with extrapolating the laboratory scale data to manufacturing scale due to differences that may exist across scales. Factors that may be different include: level of impurities in the feed material, lot to lot variability in feedstock impurities, design of the column housing unit with respect to cleanability, and homogeneity of the column packing. In view of these challenges, there is a need for approaches that may be able to predict column underperformance at the manufacturing scale over the product lifecycle. In case such an underperformance is predicted, the operators can unpack and repack the chromatography column beforehand and thus avoid batch loss. Chemometrics offers one such solution. In this article, we present an application of chemometrics toward the analysis of a set of chromatography profiles with the intention of predicting the various events of column underperformance including the backpressure buildup and inefficient deoxyribonucleic acid clearance. Copyright © 2012 American Institute of Chemical Engineers (AIChE).

Lead stabilization by phosphate amendments in soil impacted by paint residue.

PubMed

Schwab, A P; Lewis, K; Banks, M K

2006-01-01

The addition of phosphate was evaluated for contaminant stabilization in soils impacted by lead paint residue. Soils sampled from 15 highway bridge sites in Indiana were screened based on residual lead concentrations from paint contamination. Two appropriate bridge sites were identified in Tippecanoe County, Indiana. Soluble phosphate was added to the soil at a mole ratio of 3:1 P:Pb. The efficacy of phosphate treatment was evaluated by a physiologically based extraction test (PBET), uptake of lead by sunflowers, and leaching of lead from soil columns. Sunflowers were established on both field sites, and the mean Pb concentration in the above-ground biomass indicated that the rate of uptake was similar to plants growing in uncontaminated soil. The second bioavailability assessment was the physiologically based extraction test, designed to evaluate heavy metal availability during ingestion. After 1 year at both sites, the addition of phosphate significantly reduced the concentrations of lead extracted by PBET, indicating that the lead in the amended soils had lower bioavailability than in the unamended soils. In the column study, the contaminated soil produced the highest mass of leached Pb, and the addition of P reduced the mass of Pb in the leachate to similar levels found in the uncontaminated soil. Overall, the addition of soluble phosphate to these soils appears to be an effective approach for immobilizing Pb and reducing the associated bio-accessibility.

Who uses nursing theory? A univariate descriptive analysis of five years' research articles.

PubMed

Bond, A Elaine; Eshah, Nidal Farid; Bani-Khaled, Mohammed; Hamad, Atef Omar; Habashneh, Samira; Kataua', Hussein; al-Jarrah, Imad; Abu Kamal, Andaleeb; Hamdan, Falastine Rafic; Maabreh, Roqia

2011-06-01

Since the early 1950s, nursing leaders have worked diligently to build the Scientific Discipline of Nursing, integrating Theory, Research and Practice. Recently, the role of theory has again come into question, with some scientists claiming nurses are not using theory to guide their research, with which to improve practice. The purposes of this descriptive study were to determine: (i) Were nursing scientists' research articles in leading nursing journals based on theory? (ii) If so, were the theories nursing theories or borrowed theories? (iii) Were the theories integrated into the studies, or were they used as organizing frameworks? Research articles from seven top ISI journals were analysed, excluding regularly featured columns, meta-analyses, secondary analysis, case studies and literature reviews. The authors used King's dynamic Interacting system and Goal Attainment Theory as an organizing framework. They developed consensus on how to identify the integration of theory, searching the Title, Abstract, Aims, Methods, Discussion and Conclusion sections of each research article, whether quantitative or qualitative. Of 2857 articles published in the seven journals from 2002 to, and including, 2006, 2184 (76%) were research articles. Of the 837 (38%) authors who used theories, 460 (55%) used nursing theories, 377 (45%) used other theories: 776 (93%) of those who used theory integrated it into their studies, including qualitative studies, while 51 (7%) reported they used theory as an organizing framework for their studies. Closer analysis revealed theory principles were implicitly implied, even in research reports that did not explicitly report theory usage. Increasing numbers of nursing research articles (though not percentagewise) continue to be guided by theory, and not always by nursing theory. Newer nursing research methods may not explicitly state the use of nursing theory, though it is implicitly implied. © 2010 The Authors. Scandinavian Journal of Caring Sciences © 2010 Nordic College of Caring Science.

Kundt's Tube Experiment Using Smartphones

ERIC Educational Resources Information Center

Parolin, Sara Orsola; Pezzi, Giovanni

2015-01-01

This article deals with a modern version of Kundt's tube experiment. Using economic instruments and a couple of smartphones, it is possible to "see" nodes and antinodes of standing acoustic waves in a column of vibrating air and to measure the speed of sound.

Case Study: A Peek behind the Curtain of Tenure and Promotion

ERIC Educational Resources Information Center

Herreid, Clyde Freeman; Prud'homme-Genereux, Annie; Schiller, Nancy A.; Herreid, Ky F.; Wright, Carolyn

2015-01-01

This column provides original articles on innovations in case study teaching, assessment of the method, as well as case studies with teaching notes. This month's issue describes a survey that looks at the system for tenure and promotion.

A Potpourri of Math Ideas.

ERIC Educational Resources Information Center

Weisberg, Phyllis G.

1987-01-01

The article offers practical games and "tricks" to help remediate deficits in arithmetic and mathematics at the elementary school level. Games include using the fingers to calculate, lattice multiplication, dividing paper into equal columns, square games, code cracking games, and fraction dominoes. (Author/DB)

Don’t Let the HumBUG Get Achoo - Tips for a healthy winter at work and home

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

Schlender, Michael H.

2006-12-15

Safety-related article for recurrinig column in the Tri-City Area Journal of Business. Focuses on seasonal wellness tips for employers and employees - namely, cold and flu prevention through personal hygiene.

TASH Newsletter, 1997.

ERIC Educational Resources Information Center

TASH Newsletter, 1997

1997-01-01

Ten issues of the 1997 newsletter of TASH comprise this document. An issue typically contains news items, a column by the organization's executive director, reports from special interest groups, legislative testimony, conference information, and several major articles, such as the following: "Multicultural Perspectives: Excerpts from Opening…

Electronic School. Supplement.

ERIC Educational Resources Information Center

American School Board Journal, 1997

1997-01-01

This supplementary insert describes developments in computer uses in education. Feature articles discuss connecting rural schools to computer networks through affordable wireless transmission, using the Internet to teach foreign languages, and forging links between the school and home through technology. Other columns discuss updates on the…

Computer-Aided Construction at Designing Reinforced Concrete Columns as Per Ec

NASA Astrophysics Data System (ADS)

Zielińska, M.; Grębowski, K.

2015-02-01

The article presents the authors' computer program for designing and dimensioning columns in reinforced concrete structures taking into account phenomena affecting their behaviour and information referring to design as per EC. The computer program was developed with the use of C++ programming language. The program guides the user through particular dimensioning stages: from introducing basic data such as dimensions, concrete class, reinforcing steel class and forces affecting the column, through calculating the creep coefficient taking into account the impact of imperfection depending on the support scheme and also the number of mating members at load shit, buckling length, to generating the interaction curve graph. The final result of calculations provides two dependence points calculated as per methods of nominal stiffness and nominal curvature. The location of those points relative to the limit curve determines whether the column load capacity is assured or has been exceeded. The content of the study describes in detail the operation of the computer program and the methodology and phenomena which are indispensable at designing axially and eccentrically the compressed members of reinforced concrete structures as per the European standards.

Systematic Interpolation Method Predicts Antibody Monomer-Dimer Separation by Gradient Elution Chromatography at High Protein Loads.

PubMed

Creasy, Arch; Reck, Jason; Pabst, Timothy; Hunter, Alan; Barker, Gregory; Carta, Giorgio

2018-05-29

A previously developed empirical interpolation (EI) method is extended to predict highly overloaded multicomponent elution behavior on a cation exchange (CEX) column based on batch isotherm data. Instead of a fully mechanistic model, the EI method employs an empirically modified multicomponent Langmuir equation to correlate two-component adsorption isotherm data at different salt concentrations. Piecewise cubic interpolating polynomials are then used to predict competitive binding at intermediate salt concentrations. The approach is tested for the separation of monoclonal antibody monomer and dimer mixtures by gradient elution on the cation exchange resin Nuvia HR-S. Adsorption isotherms are obtained over a range of salt concentrations with varying monomer and dimer concentrations. Coupled with a lumped kinetic model, the interpolated isotherms predict the column behavior for highly overloaded conditions. Predictions based on the EI method showed good agreement with experimental elution curves for protein loads up to 40 mg/mL column or about 50% of the column binding capacity. The approach can be extended to other chromatographic modalities and to more than two components. This article is protected by copyright. All rights reserved.

40 CFR Appendix C to Part 61 - Quality Assurance Procedures

Code of Federal Regulations, 2013 CFR

2013-07-01

.... EC01MY92.034 In judging the suitability of alternate GC columns or the effects of altering chromatographic... that has a leading edge that rises sharply but the curve then tails off, it may be possible to define an effective width for tc as “twice the distance from the leading edge to a perpendicular line...

40 CFR Appendix C to Part 61 - Quality Assurance Procedures

Code of Federal Regulations, 2011 CFR

2011-07-01

.... EC01MY92.034 In judging the suitability of alternate GC columns or the effects of altering chromatographic... that has a leading edge that rises sharply but the curve then tails off, it may be possible to define an effective width for tc as “twice the distance from the leading edge to a perpendicular line...

40 CFR Appendix C to Part 61 - Quality Assurance Procedures

Code of Federal Regulations, 2012 CFR

2012-07-01

.... EC01MY92.034 In judging the suitability of alternate GC columns or the effects of altering chromatographic... that has a leading edge that rises sharply but the curve then tails off, it may be possible to define an effective width for tc as “twice the distance from the leading edge to a perpendicular line...

Enantiomers of dimethyl [(2E)-1,3-diphenylprop-2-en-1-yl]propanedioate resulting from allylic alkylation reaction: elution order on major high-performance liquid chromatography chiral columns.

PubMed

Ramillien, Marion; Vanthuyne, Nicolas; Jean, Marion; Gherase, Dragos; Giorgi, Michel; Naubron, Jean-Valère; Piras, Patrick; Roussel, Christian

2012-12-21

Asymmetric allylic alkylation leading to dimethyl [(2E)-1,3-diphenylprop-2-en-1-yl]propanedioate 1 is a privileged reaction which has been considered in more than 800 references from 1985 to early 2012. This paper thus begins with a thorough review of the literature with a particular focus on the way the ee's and absolute configuration of the prevailing enantiomer were claimed and reported by the authors. In a large majority of articles chiral chromatography is used for ee's determination. Unfortunately, in too many cases the data, the column or the eluent are not provided. In a significant proportion (5%) the column name is ambiguous. Furthermore, several discrepancies are detected in the assigned order of elution when chiral chromatography data are provided. We therefore decided to firmly establish the chromatographic behavior of the enantiomers of 1, which were obtained from the corresponding racemate by semi-preparative chiral chromatography and their absolute configuration assigned by ECD and VCD spectroscopies. ORD curves show that optical rotation is very weak at 350 nm with indication of inversion of the sign at lower wavelengths. It results in a low sensitivity for on line JASCO polarimeter detector. Chiroptical detection was nicely performed by on line JASCO CD detector set at 254 nm: (-)-(S)-1 shows a (+)-CD(254 nm) sign. Pure enantiomers of authenticated absolute configuration allowed a safe assignment of the order of elution during HPLC or SFC on major chiral stationary phases. Quite interestingly for practical application, the order of elution is reversed on Chiralpak AD-H and IA on going from hexane/EtOH to hexane/2-PrOH in HPLC or on going from CO(2)/EtOH (or MeOH) to CO(2)/2-PrOH in SFC. Copyright © 2012 Elsevier B.V. All rights reserved.

Testing of nylon 6 nanofibers with different surface densities as sorbents for solid phase extraction and their selectivity comparison with commercial sorbent.

PubMed

Háková, Martina; Raabová, Hedvika; Havlíková, Lucie Chocholoušová; Chocholouš, Petr; Chvojka, Jiří; Šatínský, Dalibor

2018-05-01

Nylon 6 nanofibers were tested for their ability to serve as a sorbent for solid phase extraction (SPE). The regular nanostructure providing a great sorption area and amidic functionality should lead to the assumption that nylon 6 nanofibers could be used as a novel sorbent with great potential for sample pre-treatment. However, due to the substantial differences between classical particle sorbents used for solid phase extraction and nanofibers, it is necessary to evaluate this novel approach. This article describes three types of laboratory fabricated nylon 6 nanofibers with different surface density (5.04gm -2 , 3.90gm -2 and 0.75gm -2 ) and corresponding surface areas for solid phase extraction of several groups of compounds with different structural and physicochemical properties (parabens, steroids, flavonoids and pesticides). The nanofibers were created by needleless electrospinning. Extraction columns were manually packed in classic 1- or 3-mL plastic syringe cartridges with 26-30mg of nanofibers and the column bed was sealed with polypropylene frits. The SPE procedure followed a typical five-step protocol and the collected eluates were analyzed by HPLC with UV detection. Extraction recovery was used as a parameter to evaluate the behavior of the analytes within the SPE process. Under this set condition, the recovery of the SPE process ranged from 23.1% to 125.8%. SPE showed good repeatability (0.58-11.87% RSD) and inter-day reproducibility (3.86-9.79% RSD). The achieved results were compared with SPE using a classic particle sorbent column. Good mechanical and chemical stability of nanofibers was proved. Scanning electron microscope was used for the evaluation of morphological changes in nanostructure. Nylon 6 nanofibers proved being a cost-effective sorbent for repeated use in SPE. Nylon 6 nanofibers have great potential in miniaturized SPE enabling users to overcome troubles with high back-pressure. Copyright © 2018 Elsevier B.V. All rights reserved.

Waveform generation in the weakly electric fish Gymnotus coropinae (Hoedeman): the electric organ and the electric organ discharge.

PubMed

Castelló, María E; Rodríguez-Cattáneo, Alejo; Aguilera, Pedro A; Iribarne, Leticia; Pereira, Ana Carolina; Caputi, Angel A

2009-05-01

This article deals with the electric organ and its discharge in Gymnotus coropinae, a representative species of one of the three main clades of the genus. Three regions with bilateral symmetry are described: (1) subopercular (medial and lateral columns of complex shaped electrocytes); (2) abdominal (medial and lateral columns of cuboidal and fusiform electrocytes); and (3) main [four columns, one dorso-lateral (containing fusiform electrocytes) and three medial (containing cuboidal electrocytes)]. Subopercular electrocytes are all caudally innervated whereas two of the medial subopercular ones are also rostrally innervated. Fusiform electrocytes are medially innervated at the abdominal portion, and at their rostral and caudal poles at the main portion. Cuboidal electrocytes are always caudally innervated. The subopercular portion generates a slow head-negative wave (V(1r)) followed by a head-positive spike (V(3r)). The abdominal and main portions generate a fast tetra-phasic complex (V(2345ct)). Since subopercular components prevail in the near field and the rest in the far field, time coincidence of V(3r) with V(2) leads to different waveforms depending on the position of the receiver. This confirms the splitting hypothesis of communication and exploration channels based on the different timing, frequency band and reach of the regional waveforms. The following hypothesis is compatible with the observed anatomo-functional organization: V(1r) corresponds to the rostral activation of medial subopercular electrocytes and V(3r) to the caudal activation of all subopercular electrocytes; V(2), and part of V(3ct), corresponds to the successive activation of the rostral and caudal poles of dorso-lateral fusiform electrocytes; and V(345ct) is initiated in the caudal face of cuboidal electrocytes by synaptic activation (V(3ct)) and it is completed (V(45ct)) by the successive activation of rostral and caudal faces by the action currents evoked in the opposite face.

Application of mercapto-silica polymerized high internal phase emulsions for the solid-phase extraction and preconcentration of trace lead(II).

PubMed

Su, Rihui; Ruan, Guihua; Chen, Zhengyi; Du, Fuyou; Li, Jianping

2015-12-01

A new class of solid-phase extraction column prepared with grafted mercapto-silica polymerized high internal phase emulsion particles was used for the preconcentration of trace lead. First, mercapto-silica polymerized high internal phase emulsion particles were synthesized by using high internal phase emulsion polymerization and carefully assembled in a polyethylene syringe column. The influences of various parameters including adsorption pH value, adsorption and desorption solvents, flow rate of the adsorption and desorption procedure were optimized, respectively, and the suitable uploading sample volumes, adsorption capacity, and reusability of solid phase extraction column were also investigated. Under the optimum conditions, Pb(2+) could be preconcentrated quantitatively over a wide pH range (2.0-5.0). In the presence of foreign ions, such as Na(+) , K(+) , Ca(2+) , Zn(2+) , Mg(2+) , Cu(2+) , Fe(2+) , Cd(2+) , Cl(-) and NO3 (-) , Pb(2+) could be recovered successfully. The prepared solid-phase extraction column performed with high stability and desirable durability, which allowed more than 100 replicate extractions without measurable changes of performance. The feasibility of the developed method was further validated by the extraction of Pb(2+) in rice samples. At three spiked levels of 40.0, 200 and 800 μg/kg, the average recoveries for Pb(2+) in rice samples ranged from 87.3 to 105.2%. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

The effect of bioturbation by Lumbriculus variegatus on transport and distribution of lead in a freshwater microcosm.

PubMed

Blankson, Emmanuel R; Klerks, Paul L

2016-05-01

The present study investigated the effect of bioturbation by the oligochaete worm Lumbriculus variegatus on the transport and environmental distribution of lead (Pb). Experiments used L. variegatus at densities of 0 ind./m(2), 2093 ind./m(2), and 8372 ind./m(2), in freshwater microcosms with Pb-spiked sediment. At the end of the 14-d experiment, Pb levels in the water column, tissues of L. variegatus, and sediment were determined, and bioturbation was quantified using luminophores. The bioturbation by L. variegatus increased Pb transport from the sediment to the water column. However, it did not significantly affect Pb bioaccumulation by L. variegatus or Pb levels in the sediment. The biodiffusion coefficient (Db) was positively related to worm density, but did not differ between Pb-spiked sediment and uncontaminated sediment. The latter finding suggests that Pb at the 100 μg/g concentration used in the present study did not affect L. variegatus bioturbation. The present study shows that bioturbation can enhance Pb transfer across the sediment-water interface and thus enhance Pb availability to organisms in the water column. © 2015 SETAC.

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

NASA Technical Reports Server (NTRS)

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 detection via good peak separation with a longer run time is a better asset than moderate peak separation with a shorter run time. Even given that RESOLVE is highly interested in water and that mission timeline is of significant importance given the short seven-to-ten-day mission timeline, worse detection with an 8m column may lead to overlooking other substances existing on the moon that could advance planetary science. Thus, I recommend the 20m column. However, if mission timeline and water separation are deemed the highest priority, the 8m column should be selected due to its ability to separate water within a shorter run time than the 20m column.

Defects and spatiotemporal disorder in a pattern of falling liquid columns

NASA Astrophysics Data System (ADS)

Brunet, Philippe; Limat, Laurent

2004-10-01

Disordered regimes of a one-dimensional pattern of liquid columns hanging below an overflowing circular dish are investigated experimentally. The interaction of two basic dynamical modes (oscillations and drift) combined with the occurrence of defects (birth of new columns, disappearances by coalescences of two columns) leads to spatiotemporal chaos. When the flow rate is progressively increased, a continuous transition between transient and permanent chaos is pointed into evidence. We introduce the rate of defects as the sole relevant quantity to quantify this “turbulence” without ambiguity. Statistics on both transient and endlessly chaotic regimes enable to define a critical flow rate around which exponents are extracted. Comparisons are drawn with other interfacial pattern-forming systems, where transition towards chaos follows similar steps. Qualitatively, careful examinations of the global dynamics show that the contamination processes are nonlocal and involve the propagation of blocks of elementary laminar states (such as propagative domains or local oscillations), emitted near the defects, which turn out to be essential ingredients of this self-sustained disorder.

Retinal co-mediator acetylcholine evokes muscarinic inhibition of recurrent excitation in frog tectum column.

PubMed

Baginskas, Armantas; Kuras, Antanas

2016-08-26

Acetylcholine receptors contribute to the control of neuronal and neuronal network activity from insects to humans. We have investigated the action of acetylcholine receptors in the optic tectum of Rana temporaria (common frog). Our previous studies have demonstrated that acetylcholine activates presynaptic nicotinic receptors, when released into the frog optic tectum as a co-mediator during firing of a single retinal ganglion cell, and causes: a) potentiation of retinotectal synaptic transmission, and b) facilitation of transition of the tectum column to a higher level of activity. In the present study we have shown that endogenous acetylcholine also activates muscarinic receptors, leading to a delayed inhibition of recurrent excitatory synaptic transmission in the tectum column. The delay of muscarinic inhibition was evaluated to be of ∼80ms, with an extent of inhibition of ∼2 times. The inhibition of the recurrent excitation determines transition of the tectum column back to its resting state, giving a functional sense for the inhibition. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Development of a numerical model for calculating exposure to toxic and nontoxic stressors in the water column and sediment from drilling discharges.

PubMed

Rye, Henrik; Reed, Mark; Frost, Tone Karin; Smit, Mathijs G D; Durgut, Ismail; Johansen, Øistein; Ditlevsen, May Kristin

2008-04-01

Drilling discharges are complex mixtures of chemical components and particles which might lead to toxic and nontoxic stress in the environment. In order to be able to evaluate the potential environmental consequences of such discharges in the water column and in sediments, a numerical model was developed. The model includes water column stratification, ocean currents and turbulence, natural burial, bioturbation, and biodegradation of organic matter in the sediment. Accounting for these processes, the fate of the discharge is modeled for the water column, including near-field mixing and plume motion, far-field mixing, and transport. The fate of the discharge is also modeled for the sediment, including sea floor deposition, and mixing due to bioturbation. Formulas are provided for the calculation of suspended matter and chemical concentrations in the water column, and burial, change in grain size, oxygen depletion, and chemical concentrations in the sediment. The model is fully 3-dimensional and time dependent. It uses a Lagrangian approach for the water column based on moving particles that represent the properties of the release and an Eulerian approach for the sediment based on calculation of the properties of matter in a grid. The model will be used to calculate the environmental risk, both in the water column and in sediments, from drilling discharges. It can serve as a tool to define risk mitigating measures, and as such it provides guidance towards the "zero harm" goal.

Hexaflexagons

ERIC Educational Resources Information Center

Gardner, Martin

2012-01-01

This article is a slightly condensed reprint of Martin Gardner's very first "Mathematical Games" column (which appeared December 1956 in "Scientific American"). Here Gardner introduces flexagons (paper polygons folded from straight or crooked strips of paper which have the fascinating property of changing their faces when they are "flexed"),…

Science 101: How Does Speech-Recognition Software Work?

ERIC Educational Resources Information Center

Robertson, Bill

2016-01-01

This column provides background science information for elementary teachers. Many innovations with computer software begin with analysis of how humans do a task. This article takes a look at how humans recognize spoken words and explains the origins of speech-recognition software.

Research Summaries

ERIC Educational Resources Information Center

Brock, Stephen E., Ed.

2011-01-01

This column features summaries of five research articles relevant to school crisis response. The first, "High School Teachers' Experiences With Suicidal Students," summarized by Robyn Bratica, offers the results of a study examining high school teachers' experiences with suicidal students and suggests that contact with suicidal students is very…

Wilderness Medicine Newsletter, Volume 8.

ERIC Educational Resources Information Center

Weber, Holly A., Ed.

1997-01-01

This document consists of the six issues of the "Wilderness Medicine Newsletter" published during 1997. The newsletter provides medical and rescue information for the non-physician in remote wilderness areas. Issues typically include feature articles, conference and training courses schedules, an "Ask the Expert" column, and…

Research Summaries

ERIC Educational Resources Information Center

Brock, Stephen E., Ed.

2010-01-01

This column features summaries of research articles from 3 recent crisis management publications. The first, "School Shootings and Counselor Leadership: Four Lessons from the Field" summarized by Kristi Fenning, was conducted as the result of the increased demand for trained crisis personnel on school campuses. Survey participants were…

TASH Connections, 2001.

ERIC Educational Resources Information Center

Newton, Priscilla, Ed.

2001-01-01

Seven 2001 issues of the newsletter of TASH, formerly The Association for Persons with Severe Handicaps, comprise this document. Each issue typically contains news items, a column by the organization's executive director, reports from special interest groups, legislative testimony, conference information, and several major articles relating to…

Zein purification: the process, the product, market potential

USDA-ARS?s Scientific Manuscript database

The objectives of this article intend to give an overview of a zein purification, decolorization and deodorization process, methodologies to assess those properties and applications of the purified product. The process involves column filtration of commercial zein solutions through a combination of ...

Comprehensive two-dimensional gas chromatography applied to illicit drug analysis.

PubMed

Mitrevski, Blagoj; Wynne, Paul; Marriott, Philip J

2011-11-01

Multidimensional gas chromatography (MDGC), and especially its latest incarnation--comprehensive two-dimensional gas chromatography (GC × GC)--have proved advantageous over and above classic one-dimensional gas chromatography (1D GC) in many areas of analysis by offering improved peak capacity, often enhanced sensitivity and, especially in the case of GC × GC, the unique feature of 'structured' chromatograms. This article reviews recent advances in MDGC and GC × GC in drug analysis with special focus on ecstasy, heroin and cocaine profiling. Although 1D GC is still the method of choice for drug profiling in most laboratories because of its simplicity and instrument availability, GC × GC is a tempting proposition for this purpose because of its ability to generate a higher net information content. Effluent refocusing due to the modulation (compression) process, combined with the separation on two 'orthogonal' columns, results in more components being well resolved and therefore being analytically and statistically useful to the profile. The spread of the components in the two-dimensional plots is strongly dependent on the extent of retention 'orthogonality' (i.e. the extent to which the two phases possess different or independent retention mechanisms towards sample constituents) between the two columns. The benefits of 'information-driven' drug profiling, where more points of reference are usually required for sample differentiation, are discussed. In addition, several limitations in application of MDGC in drug profiling, including data acquisition rate, column temperature limit, column phase orthogonality and chiral separation, are considered and discussed. Although the review focuses on the articles published in the last decade, a brief chronological preview of the profiling methods used throughout the last three decades is given.

The impact analysis of the connecting pipe length and diameter on the operation of a piston hybrid power machine of positive displacement with gas suction capacity

NASA Astrophysics Data System (ADS)

Shcherba, V. E.; Grigoriev, A. V.; Averyanov, G. S.; Surikov, V. I.; Vedruchenko, V. P.; Galdin, N. S.; Trukhanova, D. A.

2017-08-01

The article analyzes the impact of the connecting liquid pipe length and diameter on consumables and power characteristics of the piston hybrid power machine with gas suction capacity. The following operating characteristics of the machine were constructed and analyzed: the average height of the liquid column in the jacket space; instantaneous velocity and height of the liquid column in the jacket space; the relative height of the liquid column in the jacket space; volumetric efficiency; indicator isothermal efficiency; flowrate in the pump section; relative pressure losses during suction; relative flowrate. The dependence of the instantaneous pressure in the work space and the suction space of the compressor section on the rotation angle of the crankshaft is determined for different values of the length and diameter of the connecting pipeline.

Ransomware: Minimizing the Risks.

PubMed

Pope, Justin

2016-01-01

This ongoing column is dedicated to providing information to our readers on managing legal risks associated with medical practice. We invite questions from our readers. The answers are provided by PRMS, Inc. (www.prms.com), a manager of medical professional liability insurance programs with services that include risk management consultation, education and onsite risk management audits, and other resources to healthcare providers to help improve patient outcomes and reduce professional liability risk. The answers published in this column represent those of only one risk management consulting company. Other risk management consulting companies or insurance carriers may provide different advice, and readers should take this into consideration. The information in this column does not constitute legal advice. For legal advice, contact your personal attorney. Note: The information and recommendations in this article are applicable to physicians and other healthcare professionals so "clinician" is used to indicate all treatment team members.

Risk Management Issues When Taking Locum Tenens Assignments.

PubMed

Cash, Charles D

2017-01-01

This ongoing column is dedicated to providing information to our readers on managing legal risks associated with medical practice. We invite questions from our readers. The answers are provided by PRMS, Inc. (www.prms.com), a manager of medical professional liability insurance programs with services that include risk management consultation, education and onsite risk management audits, and other resources to healthcare providers to help improve patient outcomes and reduce professional liability risk. The answers published in this column represent those of only one risk management consulting company. Other risk management consulting companies or insurance carriers may provide different advice, and readers should take this into consideration. The information in this column does not constitute legal advice. For legal advice, contact your personal attorney. Note: The information and recommendations in this article are applicable to physicians and other healthcare professionals so "clinician" is used to indicate all treatment team members.

Managing Your Aging Patient Population

PubMed Central

McNary, Ann L.

2017-01-01

This ongoing column is dedicated to providing information to our readers on managing legal risks associated with medical practice. We invite questions from our readers. The answers are provided by PRMS, Inc. (www.prms.com), a manager of medical professional liability insurance programs with services that include risk management consultation, education and onsite risk management audits, and other resources to healthcare providers to help improve patient outcomes and reduce professional liability risk. The answers published in this column represent those of only one risk management consulting company. Other risk management consulting companies or insurance carriers may provide different advice, and readers should take this into consideration. The information in this column does not constitute legal advice. For legal advice, contact your personal attorney. Note: The information and recommendations in this article are applicable to physicians and other healthcare professionals so “clinician” is used to indicate all treatment team members. PMID:28584697

Ransomware: Minimizing the Risks

PubMed Central

Pope, Justin

2016-01-01

This ongoing column is dedicated to providing information to our readers on managing legal risks associated with medical practice. We invite questions from our readers. The answers are provided by PRMS, Inc. (www.prms.com), a manager of medical professional liability insurance programs with services that include risk management consultation, education and onsite risk management audits, and other resources to healthcare providers to help improve patient outcomes and reduce professional liability risk. The answers published in this column represent those of only one risk management consulting company. Other risk management consulting companies or insurance carriers may provide different advice, and readers should take this into consideration. The information in this column does not constitute legal advice. For legal advice, contact your personal attorney. Note: The information and recommendations in this article are applicable to physicians and other healthcare professionals so “clinician” is used to indicate all treatment team members. PMID:28210525

Risk Management Issues When Taking Locum Tenens Assignments

PubMed Central

Cash, Charles D.

2017-01-01

This ongoing column is dedicated to providing information to our readers on managing legal risks associated with medical practice. We invite questions from our readers. The answers are provided by PRMS, Inc. (www.prms.com), a manager of medical professional liability insurance programs with services that include risk management consultation, education and onsite risk management audits, and other resources to healthcare providers to help improve patient outcomes and reduce professional liability risk. The answers published in this column represent those of only one risk management consulting company. Other risk management consulting companies or insurance carriers may provide different advice, and readers should take this into consideration. The information in this column does not constitute legal advice. For legal advice, contact your personal attorney. Note: The information and recommendations in this article are applicable to physicians and other healthcare professionals so “clinician” is used to indicate all treatment team members. PMID:28386523

Bed morphological features associated with an optimal slurry concentration for reproducible preparation of efficient capillary ultrahigh pressure liquid chromatography columns.

PubMed

Reising, Arved E; Godinho, Justin M; Jorgenson, James W; Tallarek, Ulrich

2017-06-30

Column wall effects and the formation of larger voids in the bed during column packing are factors limiting the achievement of highly efficient columns. Systematic variation of packing conditions, combined with three-dimensional bed reconstruction and detailed morphological analysis of column beds, provide valuable insights into the packing process. Here, we study a set of sixteen 75μm i.d. fused-silica capillary columns packed with 1.9μm, C18-modified, bridged-ethyl hybrid silica particles slurried in acetone to concentrations ranging from 5 to 200mg/mL. Bed reconstructions for three of these columns (representing low, optimal, and high slurry concentrations), based on confocal laser scanning microscopy, reveal morphological features associated with the implemented slurry concentration, that lead to differences in column efficiency. At a low slurry concentration, the bed microstructure includes systematic radial heterogeneities such as particle size-segregation and local deviations from bulk packing density near the wall. These effects are suppressed (or at least reduced) with higher slurry concentrations. Concomitantly, larger voids (relative to the mean particle diameter) begin to form in the packing and increase in size and number with the slurry concentration. The most efficient columns are packed at slurry concentrations that balance these counteracting effects. Videos are taken at low and high slurry concentration to elucidate the bed formation process. At low slurry concentrations, particles arrive and settle individually, allowing for rearrangements. At high slurry concentrations, they arrive and pack as large patches (reflecting particle aggregation in the slurry). These processes are discussed with respect to column packing, chromatographic performance, and bed microstructure to help reinforce general trends previously described. Conclusions based on this comprehensive analysis guide us towards further improvement of the packing process. Copyright © 2017 Elsevier B.V. All rights reserved.

Separation of transition metals on a poly-iminodiacetic acid grafted polymeric resin column with post-column reaction detection utilising a paired emitter-detector diode system.

PubMed

Barron, Leon; O'Toole, Martina; Diamond, Dermot; Nesterenko, Pavel N; Paull, Brett

2008-12-05

The selectivity, retention and separation of transition metals on a short (2 mm x 50 mm) column packed with a poly-iminodiacetic acid functionalised polymer 10 microm resin (Dionex ProPac IMAC-10) are presented. This stationary phase, typically used for the separation of proteins, is composed of long chain poly-iminodiacetic acid groups grafted to a hydrophilic layer surrounding a 10 microm polymeric bead. Through the use of a combination of a multi-step pH and picolinic acid gradient, the separation of magnesium, iron, cobalt, cadmium, zinc, lead and copper was possible, followed by post-column reaction with 4-(2-pyridylazo) resorcinol (PAR) and absorbance detection at 510 nm using a novel and inexpensive optical detector, comprised of two light emitting diodes with one acting as a light source and the other as a detector. Column efficiency for selective transition metals was in excess of N=10,000, with the baseline separation of seven metal cations in <3 min possible under optimised conditions. Detection limits of between 5 and 81 microg/L were possible based upon a 50 microL injection volume.

Column with CNT/magnesium oxide composite for lead(II) removal from water.

PubMed

Saleh, Tawfik A; Gupta, Vinod K

2012-05-01

In this study, manganese dioxide-coated multiwall carbon nanotube (MnO(2)/CNT) nanocomposite has been successfully synthesized. The as-produced nanocomposite was characterized by different characteristic tools, such as X-ray diffraction, SEM, and FTIR. The MnO(2)/CNT nanocomposite was utilized as a fixed bed in a column system for removal of lead(II) from water. The experimental conditions were investigated and optimized. The pH range between 3 and 7 was studied; the optimum removal was found when the pH was equal to 6 and 7. The thickness of MnO(2)/CNT nanocomposite compact layer was also changed to find the optimum parameter for higher removal. It was observed that the slower the flow rates of the feed solution the higher the removal because of larger contact time.

3-D matrix template-assisted growth of oriented oxide nanowire arrays using glancing angle pulsed laser deposition

NASA Astrophysics Data System (ADS)

Wright, N.; Mateo-Feliciano, D.; Ostoski, A.; Mukherjee, P.; Witanachchi, S.

Nanosphere lithography is a combination of different methods to nanofabrication. In this work nanosphere lithography is used to study the growth of Zinc Oxide Nano-columns (ZnO NCs) on different diameter Silica Nanosphere (SNS) self-assembled templates. ZnO NCs are promising building blocks for many existing and emerging optical, electrical, and piezoelectric devices, specifically, the seeded growth of other oxide materials. Recently, reports have shown a ferroelectric phase of zinc stannate (ZnSnO3) and while lead zirconium titanate oxide (PZT) has been the main material of interest in ferroelectric and piezoelectric applications, the toxicity of lead has been of great concern. The possibility of developing lead free piezoelectric materials is of great interest in the ferroelectric community. Langmuir-Blodgett method was used to construct a self-assembled monolayer of SNSs on silicon substrates. Oriented ZnO NCs were grown on top of the spheres using the glancing angle pulsed laser deposition technique. Columns were formed in a spatially ordered closed-packed hexagonal configuration. Growth of ZnO NCs was studied as function of ambient Oxygen pressure with SNS size ranging from 250-1000 nm. Cross-sectional Scanning Electron Microscopy and X-ray diffraction (XRD) were used to study the template structure. Relative aspect ratios were studied and showed tunability of column dimensions with sphere size. XRD revealed ZnO NC arrays were c-axis oriented with hexagonal wurtzite structure.

Comments on Static vs Kinetic Friction

NASA Astrophysics Data System (ADS)

Kessler, Gabriel

2009-09-01

I'm writing to comment on the article published in the March edition of The Physics Teacher titled "Choose Wisely: Static or Kinetic Friction—The Power of Dimensionless Plots." As I was reading the article, something caught my eye that I couldn't reconcile with. It was the phrase on page 160 in the first column near the bottom. The statement was that the experimental value for the coefficient of kinetic friction was "unexpectedly greater than the coefficient of static friction!"

Putting it altogether: improving performance in heart failure outcomes, part 2.

PubMed

Clancy, Thomas R

2009-09-01

As systems evolve over time, their natural tendency is to become increasingly more complex. Studies in the field of complex systems have generated new perspectives on management in social organizations such as hospitals. Much of this research appears as a natural extension of the cross-disciplinary field of systems theory. This is the 10th in a series of articles applying complex systems science to the traditional management concepts of planning, organizing, directing, coordinating, and controlling. As follow-up to the case study in this column's June 2009 article, this article highlights the interventions and outcomes of the study.

Lead Removal From Synthetic Leachate Matrices by a Novel Ion-Exchange Material

NASA Technical Reports Server (NTRS)

Street, Kenneth W., Jr.; Hovanitz, Edward S.; Chi, Sulan

2002-01-01

This report discusses the application of a novel polyacrylate-based ion-exchange material (IEM) for the removal of lead (Pb) ions from water. Preliminary testing includes the establishment of the operating pH range, capacity information, and the effect of calcium and anions in the matrix. Batch testing with powder indicates slightly different optimal operational conditions from those used for column testing. The ion exchanger is excellent for removing lead from aqueous solutions.

Transport of lead and diesel fuel through a peat soil near Juneau, AK: a pilot study.

Treesearch

Julian Deiss; Carl Byers; Dave Clover; Dave D' Amore; Alan Love; Malcolm A. Menzies; J. Powell; Todd M. Walter

2004-01-01

A set of peat column experiments was used to determine the transport potential of lead (Pb) and diesel range organics (DRO) in palustrine slope wetlands near Juneau, AK. This project is important to southeast Alaskan communities because limited land resources are forcing development of regional wetlands. This study was instigated by concerns that proposed modifications...

Telecommunications in Education (T.I.E.) News. 1996-1997.

ERIC Educational Resources Information Center

Owen, Trevor, Ed.

1997-01-01

This document consists of one volume year (four quarterly issues) of the journal "Telecommunications in Education News." Each issue contains a call for articles and three regular columns: "Editor's Message" (Trevor Owen), "President's Message" (Chuck Lynd), and "NewsBits" (Gleason Sackman, Ed.). Article…

Case Study: Student-Produced Videos for the Flipped Classroom

ERIC Educational Resources Information Center

Prud'homme-Genereux, Annie

2016-01-01

This column provides original articles on innovations in case study teaching, assessment of the method, as well as case studies with teaching notes. This month's issue describes a way of building a library of student-produced videos to use in the flipped classroom.

American School & University. Volume 77, Number 3

ERIC Educational Resources Information Center

Agron, Joe, Ed.

2004-01-01

Each month, "American School & University" provides a mix of thought-provoking features, how-to-articles, industry reports, exclusive surveys, new sections, insightful columns, new product introductions and case histories to assist education officials in better performing their jobs. This November 2004 issue includes the following: "Honoring…

Assembling a Case Study Tool Kit: 10 Tools for Teaching with Cases

ERIC Educational Resources Information Center

Prud'homme-Généreux, Annie

2017-01-01

This column provides original articles on innovations in case study teaching, assessment of the method, as well as case studies with teaching notes. The author shares the strategies and tools that teachers can use to manage a case study classroom effectively.

American School & University. Volume 77, Number 1

ERIC Educational Resources Information Center

Agron, Joe, Ed.

2004-01-01

Each month "American School & University" provides a mix of thought-provoking features, how-to-articles, industry reports, exclusive surveys, new sections, insightful columns, new product introductions and case histories to assist education officials in better performing their jobs. This September 2004 issue includes the following: "New…

American School & University. Volume 77, Number 10

ERIC Educational Resources Information Center

Agron, Joe, Ed.

2005-01-01

Each month, "American School & University" provides a mix of thought-provoking features, how-to-articles, industry reports, exclusive surveys, new sections, insightful columns, new product introductions and case histories to assist education officials in better performing their jobs. This May 2005 issue includes the following:…

Administrators as Advocates for Teacher Collaboration

ERIC Educational Resources Information Center

Ketterlin-Geller, Leanne R.; Baumer, Patricia; Lichon, Kathryn

2015-01-01

This column contends that administrators are responsible for constructing a culture of collaboration in their schools and that ultimately, the facilitation of collaboration affects students' academic achievement. Within the context of a leadership scenario, this article outlines the need for, function of, and logistical implementation of…

TASH Newsletter, 2000-2001.

ERIC Educational Resources Information Center

Newton, Priscilla, Ed.

2000-01-01

Nine year 2000 issues of the newsletter of TASH, formerly The Association for Persons with Severe Handicaps, comprise this document. Each issue typically contains news items, a column by the organization's executive director, reports from special interest groups, legislative testimony, conference information, and several major articles relating to…

Science 2.0: Communicating Science Creatively

ERIC Educational Resources Information Center

Smith, Ben; Mader, Jared

2017-01-01

This column shares web tools that support learning. The authors have been covering the International Society for Technology in Education (ISTE) standards in every issue since September 2016. This article examines the final standard, called Creative Communicator, which requires students to communicate effectively and creatively express themselves…

Point of View: Taking a Cue from Neuroscience

ERIC Educational Resources Information Center

Miele, Eleanor A.

2015-01-01

This column shares reflections or thoughtful opinions on issues of broad interest to the community. This article encourages teachers to use emerging scientific evidence to change classroom culture--accept the evidence from neuroscience and find ways to make classrooms less stressful and more successful.

American School & University. Volume 77, Number 11

ERIC Educational Resources Information Center

Agron, Joe, Ed.

2005-01-01

Each month, "American School & University" provides a mix of thought-provoking features, how-to-articles, industry reports, exclusive surveys, new sections, insightful columns, new product introductions and case histories to assist education officials in better performing their jobs. This March 2005 issue includes the following:…

American School & University. Volume 77, Number 4

ERIC Educational Resources Information Center

Agron, Joe, Ed.

2004-01-01

Each month, "American School & University" provides a mix of thought-provoking features, how-to-articles, industry reports, exclusive surveys, new sections, insightful columns, new product introductions and case histories to assist education officials in better performing their jobs. This December 2004 issue includes the following:…

Research Summaries

ERIC Educational Resources Information Center

Brock, Stephen E., Ed.

2012-01-01

In this column, members of the NASP Crisis Management in the Schools Interest Group provide summaries of three studies relevant to school crisis response. The first study investigated the prevalence of posttraumatic stress disorder (PTSD) among rescue workers. The second article explored the Child and Family Traumatic Stress Intervention, which is…

Ionic liquid stationary phases for gas chromatography.

PubMed

Poole, Colin F; Poole, Salwa K

2011-04-01

This article provides a summary of the development of ionic liquids as stationary phases for gas chromatography beginning with early work on packed columns that established details of the retention mechanism and established working methods to characterize selectivity differences compared with molecular stationary phases through the modern development of multi-centered cation and cross-linked ionic liquids for high-temperature applications in capillary gas chromatography. Since there are many reviews on ionic liquids dealing with all aspects of their chemical and physical properties, the emphasis in this article is placed on the role of gas chromatography played in the design of ionic liquids of low melting point, high thermal stability, high viscosity, and variable selectivity for separations. Ionic liquids provide unprecedented opportunities for extending the selectivity range and temperature-operating range of columns for gas chromatography, an area of separation science that has otherwise been almost stagnant for over a decade. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Treatment of acid rock drainage using a sulfate-reducing bioreactor with zero-valent iron.

PubMed

Ayala-Parra, Pedro; Sierra-Alvarez, Reyes; Field, James A

2016-05-05

This study assessed the bioremediation of acid rock drainage (ARD) in flow-through columns testing zero-valent iron (ZVI) for the first time as the sole exogenous electron donor to drive sulfate-reducing bacteria in permeable reactive barriers. Columns containing ZVI, limestone or a mixture of both materials were inoculated with an anaerobic mixed culture and fed a synthetic ARD containing sulfuric acid and heavy metals (initially copper, and later also cadmium and lead). ZVI significantly enhanced sulfate reduction and the heavy metals were extensively removed (>99.7%). Solid-phase analyses showed that heavy metals were precipitated with biogenic sulfide in the columns packed with ZVI. Excess sulfide was sequestered by iron, preventing the discharge of dissolved sulfide. In the absence of ZVI, heavy metals were also significantly removed (>99.8%) due to precipitation with hydroxide and carbonate ions released from the limestone. Vertical-profiles of heavy metals in the columns packing, at the end of the experiment, demonstrated that the ZVI columns still had excess capacity to remove heavy metals, while the capacity of the limestone control column was approaching saturation. The ZVI provided conditions that enhanced sulfate reduction and generated alkalinity. Collectively, the results demonstrate an innovative passive ARD remediation process using ZVI as sole electron-donor. Copyright © 2016 Elsevier B.V. All rights reserved.

Near-Global Survey of Cloud Column Susceptibilities Using ISCCP Data

NASA Technical Reports Server (NTRS)

Han, Qingyuan; Rossow, William B.; Chou, Joyce; Welch, Ronald M.; Hansen, James E. (Technical Monitor)

2000-01-01

A new parameter, cloud column susceptibility, is introduced to study the aerosol indirect effect. There are several advantages of this new parameter in comparison with the traditional cloud susceptibility. First, no assumptions about constant liquid water content and cloud layer thickness are required in calculations so that errors caused by these assumptions can be avoided. Second, no a priori knowledge of liquid water content is necessary in remote sensing, which makes global survey by satellite data possible even though liquid water content may change significantly. Third, this new parameter can deal with variations of cloud geometrical thickness during cloud-aerosol interactions, which are evidenced by Without assuming how cloud droplet size will respond to changes of number concentration, this new parameter describes the aerosol indirect effect more directly. It addresses the question of how cloud albedo changes with increasing column number concentrations of cloud droplets, which is resulted from cloud-aerosol interactions. In this study, two approaches are used to retrieve cloud column susceptibility by satellite data. The results of both approaches show a striking contrast of cloud column susceptibilities between continental and maritime. Between the two approaches, the one that uses no assumption of constant liquid water content leads to smaller, some times even negative, cloud column susceptibilities. This finding suggests that the aerosol indirect effect may be overestimated if the assumption of constant liquid water content is used in model studies.

Sol-gel chemistry-based Ucon-coated columns for capillary electrophoresis.

PubMed

Hayes, J D; Malik, A

1997-07-18

A sol-gel chemistry-based novel approach for the preparation of a Ucon-coated fused-silica capillary column in capillary electrophoresis is presented. In this approach the sol-gel process is carried out inside 25 microm I.D. fused-silica capillaries. The sol solution contained appropriate quantities of an alkoxide-based sol-gel precursor, a polymeric coating material (Ucon), a crosslinking reagent, a surface derivatizing reagent, controlled amounts of water and a catalyst dissolved in a suitable solvent system. The coating procedure involves filling a capillary with the sol solution and allowing the sol-gel process to proceed for an optimum period. Hydrolysis of the alkoxide precursor and polycondensation of the hydrolyzed products with the surface silanol groups and the hydroxy-terminated Ucon molecules lead to the formation of a surface-bonded sol-gel coating on the inner walls of the capillary. The thickness of the coated film can be controlled by varying the reaction time, coating solution composition and experimental conditions. Commercial availability of high purity sol-gel precursors (e.g., TEOS 99.999%), the ease of coating, run-to-run and column-to-column reproducibility, and long column lifetimes make sol-gel coating chemistry very much suitable for being applied in analytical microseparations column technology. Test samples of basic proteins and nucleotides were used to evaluate the column performance. These results show that the sol-gel coating scheme has allowed for the generation of bio-compatible surfaces characterized by high separation efficiencies in CE. For different types of solutes, the sol-gel coated Ucon column consistently provided migration time R.S.D. values of the order of 0.5%.

Erratum.

PubMed

1983-10-28

In R. Jeffrey Smith's News and Comment article "Antisatellite weapon sets dangerous course" (14 Oct., p. 140), a remark on page 141 (column 3) by Richard Garwin about the usefulness of rockets, balloons, and aircraft to supplant U.S. photoreconnaissance and meterological satellites was inadvertently attributed to Robert Buchheim. And a characterization on page 141 (column 2) of the Soviet antisatellite weapon, or ASAT, was actually made by General Lewis Allen, the former Air Force chief of staff, not by General David Jones, the former chairman of the Joint Chiefs of Staff. Finally, a footnote on page 142 should have identified the Patriot as an air-to-air missile, not an air-to-ground missile.

New best estimates for radionuclide solid-liquid distribution coefficients in soils. Part 2: naturally occurring radionuclides.

PubMed

Vandenhove, H; Gil-García, C; Rigol, A; Vidal, M

2009-09-01

Predicting the transfer of radionuclides in the environment for normal release, accidental, disposal or remediation scenarios in order to assess exposure requires the availability of an important number of generic parameter values. One of the key parameters in environmental assessment is the solid liquid distribution coefficient, K(d), which is used to predict radionuclide-soil interaction and subsequent radionuclide transport in the soil column. This article presents a review of K(d) values for uranium, radium, lead, polonium and thorium based on an extensive literature survey, including recent publications. The K(d) estimates were presented per soil groups defined by their texture and organic matter content (Sand, Loam, Clay and Organic), although the texture class seemed not to significantly affect K(d). Where relevant, other K(d) classification systems are proposed and correlations with soil parameters are highlighted. The K(d) values obtained in this compilation are compared with earlier review data.

[Fetal bone and joint disorders].

PubMed

Jakobovits, Akos

2008-12-21

The article discusses the physiology and pathology of fetal bone and joint development and functions. The bones provide static support for the body. The skull and the bones of spinal column encase the central and part of the peripheral nervous system. The ribs and the sternum shield the heart and the lungs, while the bones of the pelvis protect the intraabdominal organs. Pathological changes of these bony structures may impair the functions of the respective systems or internal organs. Movements of the bones are brought about by muscles. The deriving motions are facilitated by joints. Bony anomalies of the extremities limit their effective functions. Apart from skeletal and joint abnormalities, akinesia may also be caused by neurological, muscular and skin diseases that secondarily affect the functions of bones and joints. Such pathological changes may lead to various degrees of physical disability and even to death. Some of the mentioned anomalies are recognizable in utero by ultrasound. The diagnosis may serve as medical indication for abortion in those instances when the identified abnormality is incompatible with independent life.

A study on the adsorption of heavy metals by using raw wheat bran bioadsorbent in aqueous solution phase.

PubMed

Ogata, Fumihiko; Kangawa, Moe; Iwata, Yuka; Ueda, Ayaka; Tanaka, Yuko; Kawasaki, Naohito

2014-01-01

Raw wheat bran (R-WB) was used as a biomass adsorbent. The properties of R-WB were investigated. Moreover, the adsorption of cadmium and lead ions onto R-WB was evaluated. Adsorption equilibrium of cadmium and lead ions onto R-WB was achieved within 10 h, indicating that the adsorption followed a pseudo-second-order model rather than a pseudo-first-order kinetic model. The adsorption amount increased with increasing temperature. Correlation coefficient of the Langmuir equation is 0.999 for cadmium and 0.996 for lead ions, and that of the Freundlich equation is 0.994 for cadmium and 0.993 for lead ions. The negative ΔG value implied that the adsorption of cadmium and lead ions onto R-WB is a spontaneous process. The positive ΔS value indicated an increase in randomness at the solid-liquid interface. The optimal conditions for the adsorption column experiment were investigated (space velocity (SV) 2.2 1/h, linear velocity (LV) 0.1 m/h for cadmium; SV 6.51 1/h, LV 0.23 m/h for lead ions). Further, repeated adsorption-desorption of the cadmium and lead ions could be effected by using 0.01 mol/L HCl or 0.01 mol/L HNO3 solution. Consequently, polluted water could be successfully purified by using a column filled with this bioadsorbent.

American School & University. Volume 76, Number 6

ERIC Educational Resources Information Center

Agron, Joe, Ed.

2004-01-01

Each month "American School & University" provides a mix of thought-provoking features, how-to-articles, industry reports, exclusive surveys, new sections, insightful columns, new product introductions and case histories to assist education officials in better performing their jobs. This February 2004 issue includes the following: "The Color of…

American School & University. Volume 76, Number 13

ERIC Educational Resources Information Center

American School and University, 2004

2004-01-01

Each month "American School & University" provides a mix of thought-provoking features, how-to-articles, industry reports, exclusive surveys, new sections, insightful columns, new product introductions and case histories to assist education officials in better performing their jobs. This August 2004 issue includes the following: "Wireless World"…

Tempo, 2001.

ERIC Educational Resources Information Center

Cannon, Michael, Ed.

2001-01-01

Each of the four issues of the newsletter of the Texas Association for the Gifted and Talented focus on a theme: guidance and counseling, continuing options for gifted learners, early childhood gifted, and gifted students in the global community. Issues usually contain theme-related major articles, columns by the Association's president and…

American School & University. Volume 77, Number 9

ERIC Educational Resources Information Center

Agron, Joe, Ed.

2005-01-01

Each month, "American School & University" provides a mix of thought-provoking features, how-to-articles, industry reports, exclusive surveys, new sections, insightful columns, new product introductions and case histories to assist education officials in better performing their jobs. This April 2005 issue includes the following: "Taking Pride"…

American School & University. Volume 77, Number 12

ERIC Educational Resources Information Center

Agron, Joe, Ed.

2005-01-01

Each month, "American School & University" provides a mix of thought-provoking features, how-to-articles, industry reports, exclusive surveys, new sections, insightful columns, new product introductions and case histories to assist education officials in better performing their jobs. This July 2005 issue includes the following: "Sweat Shop"…

EVALUATING ION EXCHANGE FOR REMOVING RADIUM FROM GROUNDWATER

EPA Science Inventory

This article, the second in a series, focuses on the results of bench- and pilot-scale studies of ion exchange processes for radium removal from groundwater in Lemont, Ill. Batch and column studies indicated a very high resin selectivity for radium compared with common cations. E...

TASH Newsletter, 1998.

ERIC Educational Resources Information Center

TASH Newsletter, 1998

1998-01-01

The ten 1998 issues of the newsletter of TASH comprise this document. An issue typically contains news items, a column by the organization's executive director, reports from special interest groups, legislative testimony, conference information, and several major articles, such as the following: "A Q&A on IDEA 97 with Tom Gilhool"; "Positive…

Exceptional Parent, 2002.

ERIC Educational Resources Information Center

Rader, Rick, Ed.

2002-01-01

Twelve monthly issues of this magazine for parents and others concerned with children with disabilities are contained in this document. Individual issues typically include a number of articles based on the issues theme, a special report, research reflections, and regular columns covering news items, practical answers to child rearing problems,…

American School & University. Volume 76, Number 9

ERIC Educational Resources Information Center

Agron, Joe, Ed.

2004-01-01

Each month "American School & University" provides a mix of thought-provoking features, how-to-articles, industry reports, exclusive surveys, new sections, insightful columns, new product introductions and case histories to assist education officials in better performing their jobs. This April 2004 issue includes the following: "Lifelong Learning"…

Our Town

ERIC Educational Resources Information Center

McClure, Connie

2010-01-01

This article describes how the author teaches a fourth- and fifth-grade unit on architecture called the Art and Science of Planning Buildings. Rockville, Indiana has fine examples of architecture ranging from log cabins, classic Greek columns, Victorian houses, a mission-style theater, and Frank Lloyd Wright prairie-style homes. After reading…

KOVATS RETENTION INDICES OF HALOCARBONS ON A HEXAFLUOROPROPYLENE EPOXIDE-MODIFIED GRAPHITIZED CARBON BLACK

EPA Science Inventory

The article gives results of measuring Kovats retention indices of 97 halocarbons related to research on alternative refrigerants, propellants, foaming agents, and blowing agents, on a packed-column stationary phase consisting of a 5% mass coating of a low-molecular-weight polyme...

Crisis Management Research Summaries

ERIC Educational Resources Information Center

Brock, Stephen E., Ed.

2009-01-01

In this column, Crisis Management in the Schools Interest Group members summarize recent crisis management publications. The first article summarized was a meta-analysis of the risk factors associated with Posttraumatic Stress Disorder (PTSD) among adults. The second study looked at the presence of life stressors among students who were expelled…

American School & University. Volume 76, Number 5

ERIC Educational Resources Information Center

Agron, Joe, Ed.

2004-01-01

Each month "American School & University" provides a mix of thought-provoking features, how-to-articles, industry reports, exclusive surveys, new sections, insightful columns, new product introductions and case histories to assist education officials in better performing their jobs. This January 2004 issue includes the following: "Optimism in…

American School & University. Volume 77, Number 6

ERIC Educational Resources Information Center

Agron, Joe, Ed.

2005-01-01

Each month, "American School & University" provides a mix of thought-provoking features, how-to-articles, industry reports, exclusive surveys, new sections, insightful columns, new product introductions and case histories to assist education officials in better performing their jobs. This February 2005 issue includes the following: "Under Fire"…

American School & University. Volume 77, Number 12

ERIC Educational Resources Information Center

Agron, Joe, Ed.

2005-01-01

Each month, "American School & University" provides a mix of thought-provoking features, how-to-articles, industry reports, exclusive surveys, new sections, insightful columns, new product introductions and case histories to assist education officials in better performing their jobs. This January 2005 issue includes the following: "Looking Ahead"…

Acylation of Ferrocene: A Greener Approach

ERIC Educational Resources Information Center

Birdwhistell, Kurt R.; Nguyen, Andy; Ramos, Eric J.; Kobelja, Robert

2008-01-01

The acylation of ferrocene is a common reaction used in organic laboratories to demonstrate Friedel-Crafts acylation and the purification of compounds using column chromatography. This article describes an acylation of ferrocene experiment that is more eco-friendly than the conventional acylation experiment. The traditional experiment was modified…

Leaching of heavy metals from E-waste in simulated landfill columns

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

Li Yadong; Richardson, Jay B.; Mark Bricka, R.

2009-07-15

In recent history the volume of electronic products purchased by consumers has dramatically escalated. As a result this has produced an ever-increasing electronic waste (E-waste) stream, which has generated concerns regarding the E-waste's potential for adversely impacting the environment. The leaching of toxic substances from obsolete personal computers (PCs) and cathode ray tubes (CRTs) of televisions and monitors, which are the most significant components in E-waste stream, was studied using landfill simulation in columns. Five columns were employed. One column served as a control which was filled with municipal solid waste (MSW), two columns were filled with a mixture ofmore » MSW and CRTs, and the other two were filled with MSW and computer components including printed wire boards, hard disc drives, floppy disc drives, CD/DVD drives, and power supply units. The leachate generated from the columns was monitored for toxic materials throughout the two-year duration of the study. Results indicate that lead (Pb) and various other heavy metals that were of environmental and health concern were not detected in the leachate from the simulators. When the samples of the solids were collected from underneath the E-waste in the columns and were analyzed, significant amount of Pb was detected. This indicates that Pb could readily leach from the E-waste, but was absorbed by the solids around the E-waste materials. While Pb was not observed in the leachate in this study, it is likely that the Pb would eventually enter the leachate after a long term transport.« less

On averaging aspect ratios and distortion parameters over ice crystal population ensembles for estimating effective scattering asymmetry parameters

PubMed Central

van Diedenhoven, Bastiaan; Ackerman, Andrew S.; Fridlind, Ann M.; Cairns, Brian

2017-01-01

The use of ensemble-average values of aspect ratio and distortion parameter of hexagonal ice prisms for the estimation of ensemble-average scattering asymmetry parameters is evaluated. Using crystal aspect ratios greater than unity generally leads to ensemble-average values of aspect ratio that are inconsistent with the ensemble-average asymmetry parameters. When a definition of aspect ratio is used that limits the aspect ratio to below unity (α≤1) for both hexagonal plates and columns, the effective asymmetry parameters calculated using ensemble-average aspect ratios are generally consistent with ensemble-average asymmetry parameters, especially if aspect ratios are geometrically averaged. Ensemble-average distortion parameters generally also yield effective asymmetry parameters that are largely consistent with ensemble-average asymmetry parameters. In the case of mixtures of plates and columns, it is recommended to geometrically average the α≤1 aspect ratios and to subsequently calculate the effective asymmetry parameter using a column or plate geometry when the contribution by columns to a given mixture’s total projected area is greater or lower than 50%, respectively. In addition, we show that ensemble-average aspect ratios, distortion parameters and asymmetry parameters can generally be retrieved accurately from simulated multi-directional polarization measurements based on mixtures of varying columns and plates. However, such retrievals tend to be somewhat biased toward yielding column-like aspect ratios. Furthermore, generally large retrieval errors can occur for mixtures with approximately equal contributions of columns and plates and for ensembles with strong contributions of thin plates. PMID:28983127

Google Scholar versus PubMed in locating primary literature to answer drug-related questions.

PubMed

Freeman, Maisha Kelly; Lauderdale, Stacy A; Kendrach, Michael G; Woolley, Thomas W

2009-03-01

Google Scholar linked more visitors to biomedical journal Web sites than did PubMed after the database's initial release; however, its usefulness in locating primary literature articles is unknown. To assess in both databases the availability of primary literature target articles; total number of citations; availability of free, full-text journal articles; and number of primary literature target articles retrieved by year within the first 100 citations of the search results. Drug information question reviews published in The Annals of Pharmacotherapy Drug Information Rounds column served as targets to determine the retrieval ability of Google Scholar and PubMed searches. Reviews printed in this column from January 2006 to June 2007 were eligible for study inclusion. Articles were chosen if at least 2 key words of the printed article were included in the PubMed Medical Subject Heading (MeSH) database, and these terms were searched in both databases. Twenty-two of 33 (67%) eligible Drug Information Rounds articles met the inclusion criteria. The median number of primary literature articles used in each of these articles was 6.5 (IQR 4.8, 8.3; mean +/- SD 8 +/- 5.4). No significant differences were found for the mean number of target primary literature articles located within the first 100 citations in Google Scholar and PubMed searches (5.1 +/- 3.9 vs 5.3 +/- 3.3; p = 0.868). Google Scholar searches located more total results than PubMed (2211.6 +/- 3999.5 vs 44.2 +/- 47.4; p = 0.019). The availability of free, full-text journal articles per Drug Information Rounds article was similar between the databases (1.8 +/- 1.7 vs 2.3 +/- 1.7; p = 0.325). More primary literature articles published prior to 2000 were located with Google Scholar searches compared with PubMed (62.8% vs 34.9%; p = 0.017); however, no statistically significant differences between the databases were observed for articles published after 2000 (66.4 vs 77.1; p = 0.074). No significant differences were identified in the number of target primary literature articles located between databases. PubMed searches yielded fewer total citations than Google Scholar results; however, PubMed appears to be more specific than Google Scholar for locating relevant primary literature articles.

The road to prevention.

PubMed

Berrino, Franco

2010-01-01

There are even too many books, magazines, and articles dedicated to prevention that involve the latest scientific findings, prejudices and commercial interests. The aim of this prevention column article is to critically analyse, in this overwhelming material, what is true, false or blatant propaganda, setting off the successful experiences with sometimes modest resources and without sophisticated technology. The goal is to promote synergy among potential players of prevention, as prevention is everyone's business: starting from international organisms, through institutional entities, and ending with families.

Correction to: Lifetime stress accelerates epigenetic aging in an urban, African American cohort: relevance of glucocorticoid signaling.

PubMed

Zannas, Anthony S; Arloth, Janine; Carrillo-Roa, Tania; Iurato, Stella; Röh, Simone; Ressler, Kerry J; Nemeroff, Charles B; Smith, Alicia K; Bradley, Bekh; Heim, Christine; Menke, Andreas; Lange, Jennifer F; Brückl, Tanja; Ising, Marcus; Wray, Naomi R; Erhardt, Angelika; Binder, Elisabeth B; Mehta, Divya

2018-05-23

Upon publication of the original article [1] it was highlighted by the authors that a transposition error affected Additional file 1, causing the misplacement of several columns and rendering the table difficult to read. This transposition does not influence any of the results nor analyses presented in the paper and has since been formally noted in this correction article; the corrected file is available here as an Additional File. The publisher apologizes for this error.

Evolution in miniaturized column liquid chromatography instrumentation and applications: An overview.

PubMed

Nazario, Carlos E D; Silva, Meire R; Franco, Maraíssa S; Lanças, Fernando M

2015-11-20

The purpose of this article is to underline the miniaturized LC instrumental system and describe the evolution of commercially available systems by discussing their advantages and drawbacks. Nowadays, there are already many miniaturized LC systems available with a great variety of pump design, interface and detectors as well as efficient columns technologies and reduced connections devices. The solvent delivery systems are able to drive the mobile phase without flow splitters and promote gradient elution using either dual piston reciprocating or syringe-type pumps. The mass spectrometry as detection system is the most widely used detection system; among many alternative ionization sources direct-EI LC-MS is a promising alternative to APCI. In addition, capillary columns are now available showing many possibilities of stationary phases, inner diameters and hardware materials. This review provides a discussion about miniaturized LC demonstrating fundamentals and instrumentals' aspects of the commercially available miniaturized LC instrumental system mainly nano and micro LC formats. This review also covers the recent developments and trends in instrumentation, capillary and nano columns, and several applications of this very important and promising field. Copyright © 2015 Elsevier B.V. All rights reserved.

A new fully automated FTIR system for total column measurements of greenhouse gases

NASA Astrophysics Data System (ADS)

Geibel, M. C.; Gerbig, C.; Feist, D. G.

2010-10-01

This article introduces a new fully automated FTIR system that is part of the Total Carbon Column Observing Network (TCCON). It will provide continuous ground-based measurements of column-averaged volume mixing ratio for CO2, CH4 and several other greenhouse gases in the tropics. Housed in a 20-foot shipping container it was developed as a transportable system that could be deployed almost anywhere in the world. We describe the automation concept which relies on three autonomous subsystems and their interaction. Crucial components like a sturdy and reliable solar tracker dome are described in detail. The automation software employs a new approach relying on multiple processes, database logging and web-based remote control. First results of total column measurements at Jena, Germany show that the instrument works well and can provide parts of the diurnal as well as seasonal cycle for CO2. Instrument line shape measurements with an HCl cell suggest that the instrument stays well-aligned over several months. After a short test campaign for side by side intercomaprison with an existing TCCON instrument in Australia, the system will be transported to its final destination Ascension Island.

Leading the Game, Losing the Competition: Identifying Leaders and Followers in a Repeated Game

PubMed Central

Seip, Knut Lehre; Grøn, Øyvind

2016-01-01

We explore a new method for identifying leaders and followers, LF, in repeated games by analyzing an experimental, repeated (50 rounds) game where Row player shifts the payoff between small and large values–a type of “investor” and Column player determines who gets the payoff–a type of “manager”. We found that i) the Investor (Row) most often is a leading player and the manager (Column) a follower. The longer the Investor leads the game, the higher is both player’s payoff. Surprisingly however, it is always the Manager that achieves the largest payoff. ii) The game has an efficient cooperative strategy where the players alternate in receiving a high payoff, but the players never identify, or accept, that strategy. iii) Under the assumption that the information used by the players is closely associated with the leader- follower sequence, and that information is available before the player’s decisions are made, the players switched LF- strategy primarily as a function of information on the Investor’s investment and moves and secondly as a function of the Manager’s payoff. PMID:26968032

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

Mahmood, U; Dauer, L; Erdi, Y

Purpose: Our goal was to evaluate low contrast detectability (LCD) for abdominal CT protocols across two CT scanner manufacturers, while producing a similar noise texture and CTDIvol for acquired images. Methods: A CIRS tissue equivalent LCD phantom containing three columns of 7 spherical targets, ranging from 10 mm to 2.4 mm, that are 5, 10, and 20 HU below the background matrix (HUBB) was scanned using two a GE HD750 64 slice scanner and a Siemens Somatom Definition AS 64 slice scanner. Protocols were designed to deliver a CTDIvol of 12.26 mGy and images were reconstructed with FBP, ASIR andmore » Sapphire. Comparisons were made with those algorithms that had matching noise power spectrum peaks (NPS). NPS information was extracted from a previously published article that matched NPS peak frequencies across manufacturers by calculating the NPS from uniform phantom images reconstructed with several IR algorithms. Results: The minimum detectable lesion size in the 20 HUBB and 10 HUBB column was 6.3 mm, and 10 mm in the 5 HUBB column for the GE HD 750 scanner. The minimum detectable lesion size in the 20 HUBB column was 4.8 mm, in the 10 HUBB column, 9.5 mm, and the 5 HUBB column, 10 mm for the Siemens Somatom Definition AS. Conclusion: Reducing radiation dose while improving or maintaining LCD is possible with application of IR. However, there are several different IR algorithms, with each generating a different resolution and noise texture. In multi-manufacturer settings, matching only the CTDIvol between manufacturers may Result in a loss of clinically relevant information.« less

Ozone depletion following future volcanic eruptions

NASA Astrophysics Data System (ADS)

Eric Klobas, J.; Wilmouth, David M.; Weisenstein, Debra K.; Anderson, James G.; Salawitch, Ross J.

2017-07-01

While explosive volcanic eruptions cause ozone loss in the current atmosphere due to an enhancement in the availability of reactive chlorine following the stratospheric injection of sulfur, future eruptions are expected to increase total column ozone as halogen loading approaches preindustrial levels. The timing of this shift in the impact of major volcanic eruptions on the thickness of the ozone layer is poorly known. Modeling four possible climate futures, we show that scenarios with the smallest increase in greenhouse gas concentrations lead to the greatest risk to ozone from heterogeneous chemical processing following future eruptions. We also show that the presence in the stratosphere of bromine from natural, very short-lived biogenic compounds is critically important for determining whether future eruptions will lead to ozone depletion. If volcanic eruptions inject hydrogen halides into the stratosphere, an effect not considered in current ozone assessments, potentially profound reductions in column ozone would result.

Analysis of on-orbit thermal characteristics of the 15-meter hoop/column antenna

NASA Technical Reports Server (NTRS)

Andersen, Gregory C.; Farmer, Jeffery T.; Garrison, James

1987-01-01

In recent years, interest in large deployable space antennae has led to the development of the 15 meter hoop/column antenna. The thermal environment the antenna is expected to experience during orbit is examined and the temperature distributions leading to reflector surface distortion errors are determined. Two flight orientations corresponding to: (1) normal operation, and (2) use in a Shuttle-attached flight experiment are examined. A reduced element model was used to determine element temperatures at 16 orbit points for both flight orientations. The temperature ranged from a minimum of 188 K to a maximum of 326 K. Based on the element temperatures, orbit position leading to possible worst case surface distortions were determined, and the subsequent temperatures were used in a static finite element analysis to quantify surface control cord deflections. The predicted changes in the control cord lengths were in the submillimeter ranges.

Simplifying Electron Beam Channeling in Scanning Transmission Electron Microscopy (STEM).

PubMed

Wu, Ryan J; Mittal, Anudha; Odlyzko, Michael L; Mkhoyan, K Andre

2017-08-01

Sub-angstrom scanning transmission electron microscopy (STEM) allows quantitative column-by-column analysis of crystalline specimens via annular dark-field images. The intensity of electrons scattered from a particular location in an atomic column depends on the intensity of the electron probe at that location. Electron beam channeling causes oscillations in the STEM probe intensity during specimen propagation, which leads to differences in the beam intensity incident at different depths. Understanding the parameters that control this complex behavior is critical for interpreting experimental STEM results. In this work, theoretical analysis of the STEM probe intensity reveals that intensity oscillations during specimen propagation are regulated by changes in the beam's angular distribution. Three distinct regimes of channeling behavior are observed: the high-atomic-number (Z) regime, in which atomic scattering leads to significant angular redistribution of the beam; the low-Z regime, in which the probe's initial angular distribution controls intensity oscillations; and the intermediate-Z regime, in which the behavior is mixed. These contrasting regimes are shown to exist for a wide range of probe parameters. These results provide a new understanding of the occurrence and consequences of channeling phenomena and conditions under which their influence is strengthened or weakened by characteristics of the electron probe and sample.

ABCs of Being Smart: S Is for Supporting

ERIC Educational Resources Information Center

Foster, Joanne

2014-01-01

Joanne Foster's article "R We There Yet?" was first published in "Parenting for High Potential" ("PHP") in 2006, which became the springboard for the "ABCs of Being Smart" series of columns. At that time, Foster invited "PHP" readers to think about their own versions of the "ABCs of Being…

Web Development Simplified

ERIC Educational Resources Information Center

Becker, Bernd W.

2010-01-01

The author has discussed the Multimedia Educational Resource for Teaching and Online Learning site, MERLOT, in a recent Electronic Roundup column. In this article, he discusses an entirely new Web page development tool that MERLOT has added for its members. The new tool is called the MERLOT Content Builder and is directly integrated into the…

Men Learning through Life (and Men's Sheds)

ERIC Educational Resources Information Center

Golding, Barry

2015-01-01

This "Futures" column shares insights about men's learning beyond work, based on several decades of research in men's learning in international community contexts. The article focuses' particularly on men who want and need to learn to re-create and broaden their identities beyond their working lives. This practice, well established in…

The Hispanic Outlook in Higher Education, 1997-98.

ERIC Educational Resources Information Center

Hixson, Adalyn, Ed.

1998-01-01

This document consists of all of Volume 8 (26 issues) of the journal, "The Hispanic Outlook in Higher Education," a biweekly journal that addresses issues in higher education for Hispanic Americans. Each issue presents several feature articles, a policy update column called "Outlook on Washington", a description of an exemplary…

The Hispanic Outlook in Higher Education, 1998-1999.

ERIC Educational Resources Information Center

Hixson, Adalyn, Ed.

1999-01-01

This document consists of all 26 issues of Volume 9 of "The Hispanic Outlook in Higher Education," a biweekly journal that addresses issues in higher education for Hispanic Americans. Each issue contains several feature articles, a policy update column called "Outlook on Washington," a description of an exemplary program, and a…

Case Study: Puttin' on the Ritz: How to Put Science into Cases

ERIC Educational Resources Information Center

Herreid, Clyde Freeman

2017-01-01

There are multiple ways to put science into a case. This column provides original articles on innovations in case study teaching, assessment of the method, as well as case studies with teaching notes. This month's issue discusses different ways of presenting science in case studies.

American School & University. Volume 76, Number 10

ERIC Educational Resources Information Center

Agron, Joe, Ed.

2004-01-01

Each month "American School & University" provides a mix of thought-provoking features, how-to-articles, industry reports, exclusive surveys, new sections, insightful columns, new product introductions and case histories to assist education officials in better performing their jobs. This May 2004 issue includes the following: "Taking The LEED"…

Understanding Our Gifted, 1999.

ERIC Educational Resources Information Center

Goodman, Laura, Ed.

1999-01-01

The focus of these four issues of a quarterly journal on gifted children is on the total child, gifted girls, asynchrony, and teaching teachers. Each issue also includes columns on parents, the Internet, home schooling, software reviews, and recommended books. Major articles include the following: "A Circle of Friends: The Nature and Nurture of…

Engineering Encounters: Reverse Engineering

ERIC Educational Resources Information Center

McGowan, Veronica Cassone; Ventura, Marcia; Bell, Philip

2017-01-01

This column presents ideas and techniques to enhance your science teaching. This month's issue shares information on how students' everyday experiences can support science learning through engineering design. In this article, the authors outline a reverse-engineering model of instruction and describe one example of how it looked in our fifth-grade…

Surprising Styrofoam Structures

ERIC Educational Resources Information Center

Hicks, Bill

2010-01-01

In this article, the author describes an art project intended for high-school students to create a three-dimensional design using a Styrofoam. The students were asked to find and take photos of architectural details, such as decorative columns, and use the photograph as inspiration in their drawings. The drawings served as a "blueprint" to help…

The EDUTECH Report, 2002-2003.

ERIC Educational Resources Information Center

Warger, Thomas, Ed.

2003-01-01

This document consists of 12 issues, an entire volume year, of "The EDUTECH Report." The newsletter's purpose is to alert faculty and administrators to issues in educational technology. Each issue contains two feature articles, a page of news briefs, and a question and answer column. Most issues also contain brief quotations on education…

The Hispanic Outlook in Higher Education, 2000-2001.

ERIC Educational Resources Information Center

Hixson, Adalyn, Ed.

2001-01-01

This document consists of all 25 issues of Volume 11 of "The Hispanic Outlook in Higher Education," a biweekly journal that addresses issues in higher education for Hispanic Americans. Each issue contains several feature articles, a policy update column called "Outlook on Washington," a description of an exemplary program, and…

Teaching Classical Mechanics Using Smartphones

ERIC Educational Resources Information Center

Chevrier, Joel; Madani, Laya; Ledenmat, Simon; Bsiesy, Ahmad

2013-01-01

A number of articles published in this column have dealt with topics in classical mechanics. This note describes some additional examples employing a smartphone and the new software iMecaProf. Steve Jobs presented the iPhone as "perfect for gaming." Thanks to its microsensors connected in real time to the numerical world, physics…

Oil Spill!

ERIC Educational Resources Information Center

Ansberry, Karen Rohrich; Morgan, Emily

2005-01-01

An oil spill occurs somewhere in the world almost every day of the year, and the consequences can be devastating. In this month's column, students explore the effects of oil spills on plants, animals, and the environment and investigate oil spill clean-up methods through a simulated oil spill. The activities described in this article give students…

The EDUTECH Report, 2001-2002.

ERIC Educational Resources Information Center

Warger, Thomas, Ed.

2002-01-01

This document consists of 12 issues of the "EDUTECH Report." The newsletter's purpose is to alert faculty and administrators to issues in educational technology. Each issue contains two feature articles, a page of news briefs, and a question and answer column. Issues also contain brief quotations on education technology topics. The…

Effect of Subgrid Heterogeneity on Scaling Geochemical and Biogeochemical Reactions: A Case of U(VI) Desorption

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

Liu, Chongxuan; Shang, Jianying; Shan, Huimei

2014-02-04

The effect of subgrid heterogeneity in sediment properties on the rate of uranyl[U(VI)] desorption was investigated using a sediment collected from the US Department of Energy Hanford site. The sediment was sieved into 7 grain size fractions that each exhibited different U(VI) desorption properties. Six columns were assembled using the sediment with its grain size fractions arranged in different spatial configurations to mimic subgrid heterogeneity in reactive transport properties. The apparent rate of U(VI) desorption varied significantly in the columns. Those columns with sediment structures leading to preferential transport had much lower rates of U(VI) desorption than those with relativelymore » homogeneous transport. Modeling analysis indicated that the U(VI) desorption model and parameters characterized from well-mixed reactors significantly over-predicted the measured U(VI) desorption in the columns with preferential transport. A dual domain model, which operationally separates reactive transport properties into two subgrid domains improved the predictions significantly. A similar effect of subgrid heterogeneity, albeit at a less degree, was observed for denitrification, which also occurred in the columns. The results imply that subgrid heterogeneity is an important consideration in extrapolating reaction rates from the laboratory to field.« less

Studies on affecting factors and mechanism of treating decentralized domestic sewage by a novel anti-clogging soil infiltration system.

PubMed

Yuan, Haiping; Nie, Junying; Gu, Lin; Zhu, Nanwen

2016-12-01

The effects of bore diameter and particle size of polyurethane (PU) foam on soil wastewater infiltration system as well as its anti-clogging mechanism were investigated in this study. Different types of PU were used to determine the effect of bore diameter and particle size on the chemical oxygen demand (COD) removal. The results revealed that bore diameter showed little effects and the optimal size of PU should be not less than 10 mm. The formation of strong hydrophilic group on the outer layer of hydrophobic PU foam was fixed with active ingredient Al2O3, leading to good anti-clogging effect. Denaturing gradient gel electrophoresis fingerprint profiles and cluster analysis showed that the microbial community in the bottom was different from that in other places of the normal column, while it in the top has obvious differences from that in other places of the clogging column. Furthermore, the dominant microbial species of the normal column was Betaproteobacteria while Alphaproteobacteria in the clogging column.

Heavy metal adsorption changes of EAF steel slag after phosphorus adsorption.

PubMed

Song, Guanling; Cao, Lijing; Chen, Xiao; Hou, Wenhua; Wang, Qunhui

2012-01-01

A kind of electric arc furnace (EAF) steel slag was phosphated, and its isothermal and dynamic adsorptions of copper, cadmium, and lead ions were measured to determine if heavy metal adsorption changes after phosphorus adsorption. The surface area increased greatly after the slag was phosphated. Isothermal adsorption experiments showed that the theoretical Q(max) of the EAF steel slag on Cu(2+), Cd(2+), and Pb(2+) improved 59, 50, and 89% respectively after it was phosphated. Dynamic adsorption results showed that the greatest adsorption capacities of unit volume of Cu(2+), Cd(2+), and Pb(2+) were 2.2, 1.8, and 1.8 times that of the column packed with original EAF steel slag when the column was packed with phosphate EAF steel slag at the same heavy metal ion concentration. The breakthrough time, the exhaustion time and elution efficiency of the column also increased when the column was packed with phosphated EAF steel slag compared with that packed with original EAF steel slag. Phosphorus adsorption could further improve the heavy metal ion adsorption of the EAF steel slag.

Simulating the injection of micellar solutions to recover diesel in a sand column.

PubMed

Bernardez, Letícia A; Therrien, René; Lefebvre, René; Martel, Richard

2009-01-26

This paper presents numerical simulations of laboratory experiments where diesel, initially present at 18% residual saturation in a sand column, was recovered by injecting a micellar solution containing the surfactant Hostapur SAS-60 (SAS), and two alcohols, n-butanol (n-BuOH), and n-pentanol (n-PeOH). The micellar solution was developed and optimized for diesel recovery using phase diagrams and soil column experiments. Numerical simulations with the compositional simulator UTCHEM agree with the experimental results and show that the entire residual diesel in the sand column was recovered after the downward injection of 5 pore volumes of the micellar solution. Recovery of diesel occurs by enhanced solubility in the microemulsion phase and by mobilization. An additional series of simulations investigated the effects of phase transfer, alcohol partitioning, and component segregation on diesel recovery. These simulations indicate that diesel can be accurately represented in the model by a single component, but that the pseudo-component approach for active matter and the assumption of local phase equilibrium leads to an underestimation of diesel mobilization.

Simulating the injection of micellar solutions to recover diesel in a sand column

NASA Astrophysics Data System (ADS)

Bernardez, Letícia A.; Therrien, René; Lefebvre, René; Martel, Richard

2009-01-01

This paper presents numerical simulations of laboratory experiments where diesel, initially present at 18% residual saturation in a sand column, was recovered by injecting a micellar solution containing the surfactant Hostapur SAS-60 (SAS), and two alcohols, n-butanol ( n-BuOH), and n-pentanol ( n-PeOH). The micellar solution was developed and optimized for diesel recovery using phase diagrams and soil column experiments. Numerical simulations with the compositional simulator UTCHEM agree with the experimental results and show that the entire residual diesel in the sand column was recovered after the downward injection of 5 pore volumes of the micellar solution. Recovery of diesel occurs by enhanced solubility in the microemulsion phase and by mobilization. An additional series of simulations investigated the effects of phase transfer, alcohol partitioning, and component segregation on diesel recovery. These simulations indicate that diesel can be accurately represented in the model by a single component, but that the pseudo-component approach for active matter and the assumption of local phase equilibrium leads to an underestimation of diesel mobilization.

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

NASA Astrophysics Data System (ADS)

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

2006-01-01

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

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

Hull, L.C.

The Prickett and Lonnquist two-dimensional groundwater model has been programmed for the Apple II minicomputer. Both leaky and nonleaky confined aquifers can be simulated. The model was adapted from the FORTRAN version of Prickett and Lonnquist. In the configuration presented here, the program requires 64 K bits of memory. Because of the large number of arrays used in the program, and memory limitations of the Apple II, the maximum grid size that can be used is 20 rows by 20 columns. Input to the program is interactive, with prompting by the computer. Output consists of predicted lead values at themore » row-column intersections (nodes).« less

SPAX - PAX with Super-Pages

NASA Astrophysics Data System (ADS)

Bößwetter, Daniel

Much has been written about the pros and cons of column-orientation as a means to speed up read-mostly analytic workloads in relational databases. In this paper we try to dissect the primitive mechanisms of a database that help express the coherence of tuples and present a novel way of organizing relational data in order to exploit the advantages of both, the row-oriented and the column-oriented world. As we go, we break with yet another bad habit of databases, namely the equal granularity of reads and writes which leads us to the introduction of consecutive clusters of disk pages called super-pages.

Development of a split-flow system for high precision variable sample introduction in supercritical fluid chromatography.

PubMed

Sakai, Miho; Hayakawa, Yoshihiro; Funada, Yasuhiro; Ando, Takashi; Fukusaki, Eiichiro; Bamba, Takeshi

2017-09-15

In this study, we propose a novel variable sample injection system based on full-loop injection, named the split-flow sample introduction system, for application in supercritical fluid chromatography (SFC). In this system, the mobile phase is split by the differential pressure between two back pressure regulators (BPRs) after full-loop injection suitable for SFC, and this differential pressure determines the introduction rate. Nine compounds with a wide range of characteristics were introduced with high reproducibility and universality, confirming that a robust variable sample injection system was achieved. We also investigated the control factors of our proposed system. Sample introduction was controlled by the ratio between the column-side pressure drops in splitless and split flow, ΔP columnsideinsplitless and ΔP columnsideinsplit , respectively, where ΔP columnsideinsplitless is related to the mobile phase flow rate and composition and the column resistance. When all other conditions are kept constant, increasing the make-up flow induces an additional pressure drop on the column side of the system, which leads to a reduced column-side flow rate, and hence decreased the amount of sample injected, even when the net pressure drop on the column side remains the same. Thus, sample introduction could be highly controlled at low sample introduction rate, regardless of the introduction conditions. This feature is advantageous because, as a control factor, the solvent in the make-up pump is independent of the column-side pressure drop. Copyright © 2017. Published by Elsevier B.V.

Emissions and transport of NOx over East Asia diagnosed by satellite and in-situ observations and chemical transport model results

NASA Astrophysics Data System (ADS)

Lee, H.; Kim, S.; Brioude, J.; Cooper, O. R.; Frost, G. J.; Trainer, M.; Kim, C.

2012-12-01

Nitrogen dioxide (NO2) columns observed from space have been useful in detecting the increase of NOx emissions over East Asia in accordance with rapid growth in its economy. In addition to emissions, transport can be an important factor to determine the observed satellite NO2 columns in this region. Satellite tropospheric NO2 columns showed maximum in winter and minimum in summer over the high emission areas in China, as lifetime of NO2 decreases with increase of sunlight. However, secondary peaks in the satellite NO2 columns were found in spring in both Korea and Japan, which may be influenced by transport of NOx within East Asia. Surface in-situ observations confirm the findings from the satellite measurements. The large-scale distribution of satellite NO2 columns over East Asia and the Pacific Ocean showed that the locations of NO2 column maxima coincided with wind convergence zones that change with seasons. In spring, the convergence zone is located over 30-40°N, leading to the most efficient transport of the emissions from southern China to downwind areas including Korea, Japan, and western coastal regions of the United States. We employed a Lagrangian particle dispersion model to identify the sources of the observed springtime maximum NO2. In order to understand chemical processing during the transport and quantify the roles of emissions and transport in local NOx budgets, we will also present the results from a regional chemical transport model.

Serial lectin affinity chromatography with concavalin A and wheat germ agglutinin demonstrates altered asparagine-linked sugar-chain structures of prostatic acid phosphatase in human prostate carcinoma.

PubMed

Yoshida, K I; Honda, M; Arai, K; Hosoya, Y; Moriguchi, H; Sumi, S; Ueda, Y; Kitahara, S

1997-08-01

Differences between human prostate carcinoma (PCA, five cases) and benign prostatic hyperplasia (BPH, five cases) in asparagine-linked (Asn) sugar-chain structure of prostatic acid phosphatase (PAP) were investigated using lectin affinity chromatography with concanavalin A (Con A) and wheat germ agglutinin (WGA). PAP activities were significantly decreased in PCA-derived PAP, while no significant differences between the two PAP preparations were observed in the enzymatic properties (Michaelis-Menten value, optimal pH, thermal stability, and inhibition study). In these PAP preparations, all activities were found only in the fractions which bound strongly to the Con A column and were undetectable in the Con A unbound fractions and in the fractions which bound weakly to the Con A column. The relative amounts of PAP which bound strongly to the Con A column but passed through the WGA column, were significantly greater in BPH-derived PAP than in PCA-derived PAP. In contrast, the relative amounts of PAP which bound strongly to the Con A column and bound to the WGA column, were significantly greater in PCA-derived PAP than in BPH-derived PAP. The findings suggest that Asn-linked sugar-chain structures are altered during oncogenesis in human prostate and also suggest that studies of qualitative differences of sugar-chain structures of PAP might lead to a useful diagnostic tool for PCA.

Efficacy of transverse tripolar spinal cord stimulator for the relief of chronic low back pain from failed back surgery.

PubMed

Buvanendran, Asokumar; Lubenow, Timothy J

2008-01-01

Failed back surgery syndrome is a common clinical entity for which spinal cord stimulation has been found to be an effective mode of analgesia, but with variable success rates. To determine if focal stimulation of the dorsal columns with a transverse tripolar lead might achieve deeper penetration of the electrical stimulus into the spinal cord and therefore provide greater analgesia to the back. Case report. We describe a 42-year-old female with failed back surgery syndrome that had greater back pain than leg pain. The tripolar lead configuration was achieved by placing percutaneously an octapolar lead in the spinal midline followed by 2 adjacent quadripolar leads, advanced to the T7-T10 vertebral bodies. Tripolar stimulation pattern resulted in more than 70% pain relief in this patient during the screening trial, while stimulation of one or 2 electrodes only provided 20% pain relief. After implantation of a permanent tripolar electrode system with a single rechargeable battery, the pain relief was maintained for one year. This is case report describing a case of a patient with chronic low back pain with a diagnosis of failed back surgery syndrome in which transverse tripolar stimulation using an octapolar and 2 quadripolar leads appeared to be beneficial. The transverse tripolar system consists of a central cathode surrounded by anodes, using 3 leads. This arrangement may contribute to maximum dorsal column stimulation with minimal dorsal root stimulation and provide analgesia to the lower back.

Quasi-symmetric designs and equiangular tight frames

NASA Astrophysics Data System (ADS)

Fickus, Matthew; Jasper, John; Mixon, Dustin; Peterson, Jesse

2015-08-01

An equiangular tight frame (ETF) is an M×N matrix which has orthogonal equal norm rows, equal norm columns, and the inner products of all pairs of columns have the same modulus. ETFs arise in numerous applications, including compressed sensing. They also seem to be rare: despite over a decade of active research by the community, only a few construction methods have been discovered. In this article we introduce a new construction of ETFs which uses a particular set of combinatorial designs called quasi-symmetric designs. For ETFs whose entries are contained in {+1;-1}, called real constant amplitude ETFs (RCAETFs), we see that this construction is reversible, giving new quasi-symmetric designs from the known constructions RCAETFs.

A hybrid Dantzig-Wolfe, Benders decomposition and column generation procedure for multiple diet production planning under uncertainties

NASA Astrophysics Data System (ADS)

Udomsungworagul, A.; Charnsethikul, P.

2018-03-01

This article introduces methodology to solve large scale two-phase linear programming with a case of multiple time period animal diet problems under both nutrients in raw materials and finished product demand uncertainties. Assumption of allowing to manufacture multiple product formulas in the same time period and assumption of allowing to hold raw materials and finished products inventory have been added. Dantzig-Wolfe decompositions, Benders decomposition and Column generations technique has been combined and applied to solve the problem. The proposed procedure was programmed using VBA and Solver tool in Microsoft Excel. A case study was used and tested in term of efficiency and effectiveness trade-offs.

Biclustering sparse binary genomic data.

PubMed

van Uitert, Miranda; Meuleman, Wouter; Wessels, Lodewyk

2008-12-01

Genomic datasets often consist of large, binary, sparse data matrices. In such a dataset, one is often interested in finding contiguous blocks that (mostly) contain ones. This is a biclustering problem, and while many algorithms have been proposed to deal with gene expression data, only two algorithms have been proposed that specifically deal with binary matrices. None of the gene expression biclustering algorithms can handle the large number of zeros in sparse binary matrices. The two proposed binary algorithms failed to produce meaningful results. In this article, we present a new algorithm that is able to extract biclusters from sparse, binary datasets. A powerful feature is that biclusters with different numbers of rows and columns can be detected, varying from many rows to few columns and few rows to many columns. It allows the user to guide the search towards biclusters of specific dimensions. When applying our algorithm to an input matrix derived from TRANSFAC, we find transcription factors with distinctly dissimilar binding motifs, but a clear set of common targets that are significantly enriched for GO categories.

Study on the Alkaloids in Tibetan Medicine Aconitum pendulum Busch by HPLC–MSn Combined with Column Chromatography

PubMed Central

Wang, Beibei; Dong, Jie; Ji, Jiaojiao; Yuan, Jiang; Wang, Jiali; Wu, Jiarui; Tan, Peng; Liu, Yonggang

2016-01-01

A rapid, convenient and effective identification method of alkaloids was established and an attempt on isolating and analyzing the alkaloids in Aconitum pendulum Busch was conducted successfully. In this article, four high-content components including deoxyaconitine, benzoylaconine, aconine and neoline were isolated by using column chromatography. HPLC–MSn was employed to deduce the regulations of fragmentation of diterpenoid alkaloids which displayed a characteristic behavior of loss of CO(28u), CH3COOH(60u), CH3OH(32u), H2O(18u) and C6H5COOH(122u). Then, according to fragmentation regulation of mass spectrometry, 42 alkaloids were found in A. pendulum. Among them, 38 compounds were identified and 29 alkaloids were reported for the first time for this herb. Therefore, this means that HPLC–MSn combined with column chromatography could work as an effective and reliable tool for rapid identification of the chemical components of herbal medicine. PMID:26896350

A fully automated FTIR system for remote sensing of greenhouse gases in the tropics

NASA Astrophysics Data System (ADS)

Geibel, M. C.; Gerbig, C.; Feist, D. G.

2010-07-01

This article introduces a new fully automated FTIR system that is part of the Total Carbon Column Observing Network. It will provide continuous ground-based measurements of column-averaged volume mixing ratio for CO2, CH4 and several other greenhouse gases in the tropics. Housed in a 20-foot shipping container it was developed as a transportable system that could be deployed almost anywhere in the world. We describe the automation concept which relies on three autonomous subsystems and their interaction. Crucial components like a sturdy and reliable solar tracker dome are described in detail. First results of total column measurements at Jena, Germany show that the instrument works well and can provide diurnal as well as seasonal cycle for CO2. Instrument line shape measurements with an HCl cell suggest that the instrument stays well-aligned over several months. After a short test campaign for side by side intercomaprison with an existing TCCON instrument in Australia, the system will be transported to its final destination Ascension Island.

Approaches for enantioselective resolution of pharmaceuticals by miniaturised separation techniques with new chiral phases based on nanoparticles and monolithis.

PubMed

Sierra, Isabel; Marina, Maria Luisa; Pérez-Quintanilla, Damián; Morante-Zarcero, Sonia; Silva, Mariana

2016-10-01

This article discusses new developments in the preparation of nanoparticles and monoliths with emphasis upon their application as the stationary and pseudo-stationary phases for miniaturised liquid phase separation techniques, which have occurred in the last 10 years (from 2006 to the actuality). References included in this review represent current trends and state of the art in the application of these materials to the analysis, by EKC, CEC and miniaturised chromatography, of chiral compounds with environmental interest such as pharmaceuticals. Due to their extraordinary properties, columns prepared with these new chiral stationary or pseudo-stationary phases, based on materials such as gold nanoparticles, metal-organic frameworks, ordered mesoporous silicas, carbonaceous materials, polymeric-based and silica-based monoliths or molecularly imprinted materials, can usually show some improvements in the separation selectivity, column efficiency and chemical stability in comparison with conventional chiral columns available commercially. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Preparation of acryloyl β-cyclodextrin-silica hybrid monolithic column and its application in pipette tip solid-phase extraction and HPLC analysis of methyl parathion and fenthion.

PubMed

Chen, Ling; Dang, Xueping; Ai, Youhong; Chen, Huaixia

2018-05-07

An acryloyl β-cyclodextrin-silica hybrid monolithic column for pipette tip solid-phase extraction and high-performance liquid chromatography determination of methyl parathion and fenthion have been prepared through a sol-gel polymerization method. The synthesis conditions, including the volume of cross-linker and the ratio of inorganic solution to organic solution, were optimized. The prepared monolithic column was characterized by thermogravimetric analysis, scanning electron microscopy and Fourier transform infrared spectroscopy. The eluent type, volume and flow rate, sample volume, flow rate, acidity and ionic strength were optimized in detail. Under the optimized conditions, a simple and sensitive pipette tip solid-phase extraction with high-performance liquid chromatography method was developed for the determination of methyl parathion and fenthion in lettuce. The method yielded a linear calibration curve in the concentration ranges of 15-400 μg/kg for methyl parathion and 20-400 μg/kg for fenthion with correlation coefficients of above 0.9957. The limits of detection were 4.5 μg/kg for methyl parathion and 6.0 μg/kg for fenthion, respectively. The recoveries of methyl parathion and fenthion spiked in lettuce ranged from 96.0 to 104.2% with relative standard deviations less than 8.4%. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

Improvement of Liquefiable Foundation Conditions Beneath Existing Structures.

DTIC Science & Technology

1985-08-01

filter zones, and drains. Drilling fluids can cause hydraulic fracturing . These hazards can lead to to piping and hvdraulic fracturing Compression . 7...with results of piping and hydraulic fracturing (Continued) * Site conditions have been classified into three cases; Case 1 is for beneath -d...which could lead to piping and hydraulic fracturing Soil Reinforcement 16. Vibro-replacement See methods 2 and 3 stone and sand columns applicable to

Potential negative consequences of adding phosphorus-based fertilizers to immobilize lead in soil

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

Kilgour, Douglas W.; Moseley, Rebecca A.; Savage, Kaye S

2008-09-01

A study of the potential negative consequences of adding phosphate (P)-based fertilizers as amendments to immobilize lead (Pb) in contaminated soils was conducted. Lead-contaminated firing range soils also contained elevated concentrations of antimony (Sb), a common Pb hardening agent, and some arsenic (As) of unknown (possibly background) origin. After amending the soils with triple superphosphate, a relatively soluble P source, column leaching experiments revealed elevated concentrations of Sb, As, and Pb in the leachate, reflecting an initial spike in soluble Pb and a particularly dramatic increase in Sb and As mobility. Minimal As, Sb, and Pb leaching was observed duringmore » column tests performed on non-amended control soils. In vitro extractions tests were performed to assess changes in Pb, As, and Sb bioaccessibility on P amendment. Lead bioaccessibility was systematically lowered with increasing P dosage, but there was much less of an effect on As and Sb bioaccessibility than on mobility. Our results indicate that although P amendments may aid in lowering the bioaccessibility of soil-bound Pb, it may also produce an initial increase in Pb mobility and a significant release of Sb and As from the soil, dramatically increasing their mobility and to a lesser extent their bioavailability.« less

A Simple Approach for Demonstrating Soil Water Retention and Field Capacity

ERIC Educational Resources Information Center

Howard, A.; Heitman, J. L.; Bowman, D.

2010-01-01

It is difficult to demonstrate the soil water retention relationship and related concepts because the specialized equipment required for performing these measurements is unavailable in most classrooms. This article outlines a low-cost, easily visualized method by which these concepts can be demonstrated in most any classroom. Columns (62.5 cm…

Case Study: The Chemistry of Cocaine

ERIC Educational Resources Information Center

Dewprashad, Brahmadeo

2011-01-01

This column provides original articles on innovations in case study teaching, assessment of the method, as well as case studies with teaching notes. This month's case study focuses on the chemistry of cocaine to teach a number of core concepts in organic chemistry. It also requires that students read and analyze an original research paper on…

WAR Metaphor in the Chinese Economic Media Discourse

ERIC Educational Resources Information Center

Hu, Chunyu; Xu, Yuting

2017-01-01

The economic media discourse depends upon a complex web of metaphors, among which WAR metaphor is worthy of special attention. The data used in this study is comprised of 2566 articles (about 1.2 million words) under the "Economy" column of China Daily published in 2014. Critical Metaphor Analysis (CMA) is used as the analytical…

The North Central Association as a Spiritual Force (1946)

ERIC Educational Resources Information Center

Koch, Harlan C.

1975-01-01

Professor Harlan C. Koch of the University of Michigan served as managing editor of the Quarterly for a number of years, and contributed short columns of comment on current issues. The final article of this fifty-years overview of the Quarterly is such a comment of his, written in 1946. (Editor/RK)

Economic "Revelations" and the Metaphors of the Meltdown: An Educational Deconstruction

ERIC Educational Resources Information Center

Stronach, Ian; Clarke, John; Frankham, Jo

2014-01-01

This article subjects contemporary informed discourse on the Credit Crunch/Great Recession/Long Recession to educational analysis and deconstruction. Such pro-capitalist but not uncritical discourse is well represented by the UK "Financial Times", whose columns between 2008 and 2012 comprise most of our data. We argue that the metaphors…

49 CFR Appendix A to Part 1035 - Uniform Straight Bill of Lading

Code of Federal Regulations, 2010 CFR

2010-10-01

... as indicated below, which said company (the word company being understood throughout this contract as... at any time interested in all or any of said property, that every service to be performed hereunder... of articles, special marks, and exceptions *Weight (subject to correction) Class or rate Check column...

Like It Is.

ERIC Educational Resources Information Center

Education Unlimited, 1979

1979-01-01

The column presents three brief articles on mainstreaming. W. Tice presents his view that Public Law 94-142 (the Education for All Handicapped Children Act) has been a disaster for American education. J. Halpert discusses problems in the implementation of P.L. 94-142. One high school's response to the mainstreaming mandate is recounted by P.…

Advocacy: Making the Gold Standard School a Reality

ERIC Educational Resources Information Center

Roberts, Julia Link; Inman, Tracy Ford

2011-01-01

In their last column, the authors described a Gold Standard School--a place in which all children thrive including the gifted and talented. The Checklist for a Gold Standard School, which is included in this article, highlights the main characteristics of such a school including a focus on continuous progress, talent development, policies that…

The EDUTECH Report. The Education Technology Newsletter for Faculty and Administrators, 1992-1993.

ERIC Educational Resources Information Center

EDUTECH Report, 1993

1993-01-01

This newsletter examines education technology issues of concern to school faculty and administrators. Regular features in each issue include educational technology news, a book review, and a question and answer column. The cover articles during this volume year are: "Data Access Issues: Security Vs. Openness"; "Creation of an…

Inside View: A Leader's Observations on Leadership.

ERIC Educational Resources Information Center

Ulmer, Walter F., Jr.

Walter F. Ulmer, Jr., is a retired three-star general in the United States Army and former president and chief executive officer of the Center for Creative Leadership. This book is a compilation of columns that he wrote during 1990-94 for the Center's periodical "Issues and Observations." The articles emphasize learning as the essential connection…

Management Matters: The Library Media Specialist's Management Toolbox

ERIC Educational Resources Information Center

Pappas, Marjorie L.

2004-01-01

Library media specialists need tools to help them manage the school library media program. The Internet includes a vast array of tools that a library media specialist might find useful. The websites and electronic resources included in this article are only a representative sample and future columns may explore additional tools. All the tools are…

The EDUTECH Report. The Education Technology Newsletter for Faculty and Administrators, 1994-1995.

ERIC Educational Resources Information Center

EDUTECH Report, 1995

1995-01-01

This newsletter examines education technology issues of concern to school faculty and administrators. Regular features in each issue include educational technology news, a book review, and a question and answer column. The cover articles during this volume year are: "The Decision-Making Process: as Important as the Decision";…

A Puzzle Used to Teach the Cardiac Cycle

ERIC Educational Resources Information Center

Marcondes, Fernanda K.; Moura, Maria J. C. S.; Sanches, Andrea; Costa, Rafaela; Oliveira de Lima, Patricia; Groppo, Francisco Carlos; Amaral, Maria E. C.; Zeni, Paula; Gaviao, Kelly Cristina; Montrezor, Luís H.

2015-01-01

The aim of the present article is to describe a puzzle developed for use in teaching cardiac physiology classes. The puzzle presents figures of phases of the cardiac cycle and a table with five columns: phases of cardiac cycle, atrial state, ventricular state, state of atrioventricular valves, and pulmonary and aortic valves. Chips are provided…

The EDUTECH Report, 1997-1998.

ERIC Educational Resources Information Center

EDUTECH Report, 1998

1998-01-01

This document consists of 12 issues of the EDUTECH Report. 1998. The newsletter's purpose is to alert faculty and administrators to issues in educational technology. Each issue contains two feature articles, a page of news briefs, a preview of the upcoming issue, and a question and answer column. Most issues also contain brief quotations on…

The EDUTECH Report, 2000-2001.

ERIC Educational Resources Information Center

Warger, Thomas, Ed.

2001-01-01

This document consists of 12 issues, an entire volume year, of the EDUTECH Report. The newsletter's purpose is to alert faculty and administrators to issues in educational technology. Each issue contains two feature articles, a page of news briefs, a preview of the upcoming issue, and a question and answer column. Most issues also contain brief…

The EDUTECH Report, 1998-1999.

ERIC Educational Resources Information Center

EDUTECH Report, 1999

1999-01-01

This document consists of 12 issues, an entire volume year, of the EDUTECH Report. The newsletter's purpose is to alert faculty and administrators to issues in educational technology. Each issue contains two feature articles, a page of news briefs, a preview of the upcoming issue, and a question and answer column. Most issues also contain brief…

The EDUTECH Report, 1999-2000.

ERIC Educational Resources Information Center

EDUTECH Report, 2000

2000-01-01

This document consists of the 12 issues, an entire volume year, of the 1999-2000 EDUTECH Report. The newsletter's purpose is to alert faculty and administrators to issues in educational technology. Each issue contains two or three articles, a page of news briefs, a preview of the upcoming issue, and a question and answer column. Most issues also…

Manage Your Social Media in 5 Minutes a Day

ERIC Educational Resources Information Center

Watson, Anne Marie

2017-01-01

The Marketing column features essays about a variety of creative and innovative marketing strategies used to highlight collections or promote services in all types of libraries. Its purpose is to provide real examples of how libraries are using marketing and outreach techniques in interesting ways. This article describes the social media content…

The EDUTECH Report. The Education Technology Newsletter for Faculty and Administrators, 1993-1994.

ERIC Educational Resources Information Center

EDUTECH Report, 1994

1994-01-01

This newsletter examines education technology issues of concern to school faculty and administrators. Regular features in each issue include educational technology news, a book review, and a question and answer column. The cover articles during this volume year are: "The Build-or-Buy Decision: No One Right Answer"; "The National…

In situ quantitative characterisation of the ocean water column using acoustic multibeam backscatter data

NASA Astrophysics Data System (ADS)

Lamarche, G.; Le Gonidec, Y.; Lucieer, V.; Lurton, X.; Greinert, J.; Dupré, S.; Nau, A.; Heffron, E.; Roche, M.; Ladroit, Y.; Urban, P.

2017-12-01

Detecting liquid, solid or gaseous features in the ocean is generating considerable interest in the geoscience community, because of their potentially high economic values (oil & gas, mining), their significance for environmental management (oil/gas leakage, biodiversity mapping, greenhouse gas monitoring) as well as their potential cultural and traditional values (food, freshwater). Enhancing people's capability to quantify and manage the natural capital present in the ocean water goes hand in hand with the development of marine acoustic technology, as marine echosounders provide the most reliable and technologically advanced means to develop quantitative studies of water column backscatter data. This is not developed to its full capability because (i) of the complexity of the physics involved in relation to the constantly changing marine environment, and (ii) the rapid technological evolution of high resolution multibeam echosounder (MBES) water-column imaging systems. The Water Column Imaging Working Group is working on a series of multibeam echosounder (MBES) water column datasets acquired in a variety of environments, using a range of frequencies, and imaging a number of water-column features such as gas seeps, oil leaks, suspended particulate matter, vegetation and freshwater springs. Access to data from different acoustic frequencies and ocean dynamics enables us to discuss and test multifrequency approaches which is the most promising means to develop a quantitative analysis of the physical properties of acoustic scatterers, providing rigorous cross calibration of the acoustic devices. In addition, high redundancy of multibeam data, such as is available for some datasets, will allow us to develop data processing techniques, leading to quantitative estimates of water column gas seeps. Each of the datasets has supporting ground-truthing data (underwater videos and photos, physical oceanography measurements) which provide information on the origin and chemistry of the seep content. This is of first importance when assessing the physical properties of water column scatterers from backscatter acoustic measurement.

Comparison of high-performance liquid chromatography separation of red wine anthocyanins on a mixed-mode ion-exchange reversed-phase and on a reversed-phase column.

PubMed

Vergara, Carola; Mardones, Claudia; Hermosín-Gutiérrez, Isidro; von Baer, Dietrich

2010-09-03

Anthocyanins, which confer the characteristic color to red wine, can be used as markers to classify wines according to the grape variety. It is a complex separation that requires very high chromatographic efficiency, especially in the case of aged red wines, due to the formation of pyranoanthocyanins. A coelution between these kinds of compounds can affect the R(ac/coum) ratio of aged wines, and might lead to false results when classifying the wine variety. In 2007, the use of a novel mixed-mode ion-exchange reversed-phase column was reported to separate anthocyanins extracted from grapes of Vitis labrusca with different selectivity than C-18 columns. In the present work, the separation of anthocyanins including pyranoanthocyanins in young and aged Cabernet Sauvignon wines and other varieties is evaluated. The most interesting contributions of this research are the different elution order and selectivity obtained for anthocyanins and pyranoanthocyanins (only formed in wine), compared with those observed in C-18 stationary phases. Also interesting is the separation of the polymeric fraction, which elutes as a clearly separated peak at the chromatogram's end. However, a comparison with a high efficiency C-18 column with the same dimensions and particle size demonstrated that the tested mixed-mode column shows broader peaks with a theoretical plate number below 8000, for malvidin-3-glucoside peak, while it can be up to 10 times higher for a high efficiency C-18 column, depending on the column manufacturer. Under the tested conditions, in mixed-mode phase, the analysis time is almost twice that of a C-18 column with the same dimensions and particle size. A mixed-mode phase with increased efficiency should provide an interesting perspective for separation of anthocyanins in wine, due to its improved selectivity, combined with a useful role in a second-dimension separation in preparative anthocyanin chromatography. 2010 Elsevier B.V. All rights reserved.

Monolithic poly(1,2-bis(p-vinylphenyl)ethane) capillary columns for simultaneous separation of low- and high-molecular-weight compounds.

PubMed

Greiderer, Andreas; Ligon, S Clark; Huck, Christian W; Bonn, Günther K

2009-08-01

Monolithic poly(1,2-bis(p-vinylphenyl)ethane (BVPE)) capillary columns were prepared by thermally initiated free radical polymerisation of 1,2-bis(p-vinylphenyl)ethane in the presence of inert diluents (porogens) and alpha,alpha'-azoisobutyronitrile (AIBN) as initiator. Polymerisations were accomplished in 200 microm ID fused silica capillaries at 65 degrees C and for 60 min. Mercury intrusion porosimetry measurements of the polymeric RP support showed a broad bimodal pore-size-distribution of mesopores and small macropores in the range of 5-400 nm and flow-channels in the mum range. N(2)-adsorption (BET) analysis resulted in a tremendous enhancement of surface area (101 m(2)/g) of BVPE stationary phases compared to typical organic monoliths (approximately 20 m(2)/g), indicating the presence of a considerable amount of mesopores. Consequently, the adequate proportion of both meso- and (small) macropores allowed the rapid and high-resolution separation of low-molecular-weight compounds as well as biomolecules on the same monolithic support. At the same time, the high fraction of flow-channels provided enhanced column permeability. The chromatographic performance of poly(1,2-bis(p-vinylphenyl)ethane) capillary columns for the separation of biomolecules (proteins, oligonucleotides) and small molecules (alkyl benzenes, phenols, phenons) are demonstrated in this article. Additionally, pressure drop versus flow rate measurements of novel poly(1,2-bis(p-vinylphenyl)ethane) capillary columns confirmed high mechanical robustness, low swelling in organic solvents and high permeability. Due to the simplicity of monolith fabrication, comprehensive studies of the retention and separation behaviour of monolithic BVPE columns resulted in high run-to-run and batch-to-batch reproducibilities. All these attributes prove the excellent applicability of monolithic poly(1,2-bis(p-vinylphenyl)ethane) capillary columns for micro-HPLC towards a huge range of analytes of different chemistries and molecular sizes.

DATA QUALITY OBJECTIVE SUMMARY REPORT FOR THE 105 K EAST ION EXCHANGE COLUMN MONOLITH

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

JOCHEN, R.M.

2007-08-02

The 105-K East (KE) Basin Ion Exchange Column (IXC) cells, lead caves, and the surrounding vault are to be removed as necessary components in implementing ''Hanford Federal Facility Agreement and Consent Order'' (Ecology et al. 2003) milestone M-034-32 (Complete Removal of the K East Basin Structure). The IXCs consist of six units located in the KE Basin, three in operating positions in cells and three stored in a lead cave. Methods to remove the IXCs from the KE Basin were evaluated in KBC-28343, ''Disposal of K East Basin Ion Exchange Column Evaluation''. The method selected for removal was grouting themore » six IXCs into a single monolith for disposal at the Environmental Restoration Disposal Facility (ERDF). Grout will be added to the IXC cells, IXC lead caves containing spent IXCs, and in the spaces between the lead cave walls and metal skin, to immobilize the contaminants, provide self-shielding, minimize void space, and provide a structurally stable waste form. The waste to be offered for disposal is the encapsulated monolith defined by the exterior surfaces of the vault and the lower surface of the underlying slab. This document presents summary of the data quality objective (DQO) process establishing the decisions and data required to support decision-making activities for the disposition of the IXC monolith. The DQO process is completed in accordance with the seven-step planning process described in EPA QA/G-4, ''Guidance for the Data Quality Objectives Process'', which is used to clarify and study objectives; define the appropriate type, quantity, and quality of data; and support defensible decision-making. The DQO process involves the following steps: (1) state the problem; (2) identify the decision; (3) identify the inputs to the decision; (4) define the boundaries of the study; (5) develop a decision rule (DR); (6) specify tolerable limits on decision errors; and (7) optimize the design for obtaining data.« less

Nanoparticles in discotic liquid crystals

NASA Astrophysics Data System (ADS)

Kumar, Sandeep

The self-assembly of disc-shaped molecules creates discotic liquid crystals (DLCs). These nanomaterials of the sizes ranging from 2-6 nm are emerging as a new class of organic semiconducting materials. The unique geometry of columnar mesophases formed by discotic molecules is of great importance to study the one-dimensional charge and energy migration in organized systems. A number of applications of DLCs, such as, one-dimensional conductor, photoconductor, photovoltaic solar cells, light emitting diodes and gas sensors have been reported. The conductivity along the columns in columnar mesophases has been observed to be several orders of magnitude greater than in perpendicular direction and, therefore, DLCs are described as molecular wires. On the other hand, the fields of nanostructured materials, such as gold nanoparticles, quantum dots, carbon nanotubes and graphene, have received tremendous development in the past decade due to their technological and fundamental interest. Recently the hybridization of DLCs with various metallic and semiconducting nanoparticles has been realized to alter and improve their properties. These nanocomposites are not only of basic science interest but also lead to novel materials for many device applications. This article provides an overview on the development in the field of newly immersed discotic nanoscience. After a brief introduction of DLCs, the article will cover the inclusion of various zero-, one- and two-dimensional nanoparticles in DLCs. Finally, an outlook into the future of this newly emerging intriguing field of discotic nanoscience research will be provided.

ON ENERGY AND SUSTAINABILITY (PERSONAL COLUMN)

EPA Science Inventory

The use of energy is a major and desirable feature of modern human existence, but it has significant impact on the planetary environment. It is, therefore, an important issue in the quest for sustainability. The search for viable policies leading to energy sustainability falls ...

Production of high purity radiothallium

DOEpatents

Lebowitz, Elliot; Greene, Margaret W.

1976-11-23

The method of producing high purity thallium-201 for use as a myocardial scanning agent comprising the steps of irradiating a thallium target with protons to give the reaction .sup.203 Tl(p,3n) .sup.201.sub.Pb, separating in ion exchange columns the lead from the thallium isotopes, permitting the lead to decay, and then purifying the thallium solution and converting the thallium present to thallous form in which it can be used.

Interpretation of size-exclusion chromatography for the determination of molecular-size distribution of human immunoglobulins.

PubMed

Christians, S; Schluender, S; van Treel, N D; Behr-Gross, M-E

2016-01-01

Molecular-size distribution by size-exclusion chromatography (SEC) [1] is used for the quantification of unwanted aggregated forms in therapeutic polyclonal antibodies, referred to as human immunoglobulins (Ig) in the European Pharmacopoeia. Considering not only the requirements of the monographs for human normal Ig (0338, 0918 and 2788) [2-4], but also the general chapter on chromatographic techniques (2.2.46) [5], several chromatographic column types are allowed for performing this test. Although the EDQM knowledge database gives only 2 examples of suitable columns as a guide for the user, these monographs permit the use of columns with different lengths and diameters, and do not prescribe either particle size or pore size, which are considered key characteristics of SEC columns. Therefore, the columns used may differ significantly from each other with regard to peak resolution, potentially resulting in ambiguous peak identity assignment. In some cases, this may even lead to situations where the manufacturer and the Official Medicines Control Laboratory (OMCL) in charge of Official Control Authority Batch Release (OCABR) have differing molecular-size distribution profiles for aggregates of the same batch of Ig, even though both laboratories follow the requirements of the relevant monograph. In the present study, several formally acceptable columns and the peak integration results obtained therewith were compared. A standard size-exclusion column with a length of 60 cm and a particle size of 10 µm typically detects only 3 Ig fractions, namely monomers, dimers and polymers. This column type was among the first reliable HPLC columns on the market for this test and very rapidly became the standard for many pharmaceutical manufacturers and OMCLs for batch release testing. Consequently, the distribution of monomers, dimers and polymers was established as the basis for the interpretation of the results of the molecular-size distribution test in the relevant monographs. However, modern columns with a smaller particle size provide better resolution and also reveal a class of components designated here as oligomers. This publication addresses the interpretation of the SEC test for Ig with respect to the following questions: - how can molecular-size distribution tests benefit from the use of the most recent column technology without changing the sense of well-established quality parameters? - is it possible to mathematically define a way to interpret chromatograms generated with various column types with the same fractionation range but different resolution power? - how should oligomers be considered regarding compliance with compendial specifications?

A Greenhouse Study on Lead Uptake and Antioxidant Enzyme Activities in Vetiver Grass (Vetiveria zizanioides) as a Function of Lead Concentration and Soil Physico-Chemical Properties

NASA Astrophysics Data System (ADS)

Andra, S. P.; Datta, R.; Sarkar, D.; Saminathan, S. K.

2006-05-01

Lead (Pb) is a toxic non-essential metal that can cause permanent learning disabilities, retardation, mental and behavioral problems in children. Lead accumulation in soils result from weathering, chipping, scraping, sanding and sand blasting of housing structures constructed prior to 1978, bearing lead-based paint. The primary objective of this study is to develop a cost-effective, chelate-assisted phytoremediation for cleaning up lead contaminated soils. Soils are a unique environment of diverse physical and chemical characteristics that influence the extent of phytoavailable (labile) Pb forms. The success of phytoremediation strategy depends on the physiological/ biochemical tolerance of the plants to lipid peroxidation induced by Pb at sub-lethal levels. Oxidative challenge is alleviated by antioxidant compounds, but more importantly by the induction of antioxidant enzymes, which are crucial for scavenging reactive oxygen species (ROS) and terminating lipid peroxidation chain reaction. A column study was conducted in a temperature and humidity-controlled greenhouse setting to assess the extent of Pb phytoextraction and antioxidant response in a lead accumulator, vetiver grass (Vetiveria zizanioides). Treatments consisted of a randomized block arrangement of 4 soil types (Immokalee, Pahokee Muck, Tobosa, and Millhopper) and 3 soil Pb concentrations [normal - 400 mg/kg lead (following federal soil standards for lead), moderate - 800 mg/kg lead, and excessive - 1200 mg/kg lead] in 4 replicates. At the end of 6 months, selected columns were amended with a biodegradable chelating agent, ethylenediamene disuccinate (10 mmol/ kg EDDS), to mobilize Pb and enhance Pb uptake by vetiver. Total and exchangeable (labile) Pb were correlated with phytoextracted Pb, and levels of antioxidant enzymes viz., superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx) in the root and shoot tissues of vetiver grass. Results indicate that Pb uptake and antioxidant enzymes activity in vetiver grass is dependent on soil physico-chemical properties and phytoavailable Pb concentrations.

Hybrid Sargassum-sand sorbent: a novel adsorbent in packed column to treat metal-bearing wastewaters from inductively coupled plasma-optical emission spectrometry.

PubMed

Vijayaraghavan, K; Joshi, U M

2013-01-01

Laboratory batch and column experiments were carried out to examine the efficiency of algal-based treatment technique to clean-up wastewaters emanating from inductively coupled plasma-optical emission spectrometry (ICP-OES). Chemical characterization revealed the extreme complexity of the wastewater, with the presence of 14 different metals under very low pH (pH = 1.1), high conductivity (6.98 mS/cm), total dissolved solid (4.46 g/L) and salinity (3.77). Batch experiments using Sargassum biomass indicated that it was possible to attain high removal efficiencies at optimum pH of 4.0. Efforts were also made to continuously treat ICP-OES wastewater using up-flow packed column. However, swelling of Sargassum biomass leads to stoppage of column. To address the problem, Sargassum was mixed with sand at a ratio of 40: 60 on volume basis. Remarkably, the hybrid Sargassum-sand sorbent showed very high removal efficiency towards multiple metal ions with the column able to operate for 11 h at a flow rate of 10 mL/min. Metal ions such as Cu, Cd, and Pb were only under trace levels in the treated water until 11 h. The results of the treatment process were compared with trade effluent discharge standards. Further the process evaluation and cost analysis were presented.

Seasonal variability of stratospheric methane: implications for constraining tropospheric methane budgets using total column observations

NASA Astrophysics Data System (ADS)

Saad, Katherine M.; Wunch, Debra; Deutscher, Nicholas M.; Griffith, David W. T.; Hase, Frank; De Mazière, Martine; Notholt, Justus; Pollard, David F.; Roehl, Coleen M.; Schneider, Matthias; Sussmann, Ralf; Warneke, Thorsten; Wennberg, Paul O.

2016-11-01

Global and regional methane budgets are markedly uncertain. Conventionally, estimates of methane sources are derived by bridging emissions inventories with atmospheric observations employing chemical transport models. The accuracy of this approach requires correctly simulating advection and chemical loss such that modeled methane concentrations scale with surface fluxes. When total column measurements are assimilated into this framework, modeled stratospheric methane introduces additional potential for error. To evaluate the impact of such errors, we compare Total Carbon Column Observing Network (TCCON) and GEOS-Chem total and tropospheric column-averaged dry-air mole fractions of methane. We find that the model's stratospheric contribution to the total column is insensitive to perturbations to the seasonality or distribution of tropospheric emissions or loss. In the Northern Hemisphere, we identify disagreement between the measured and modeled stratospheric contribution, which increases as the tropopause altitude decreases, and a temporal phase lag in the model's tropospheric seasonality driven by transport errors. Within the context of GEOS-Chem, we find that the errors in tropospheric advection partially compensate for the stratospheric methane errors, masking inconsistencies between the modeled and measured tropospheric methane. These seasonally varying errors alias into source attributions resulting from model inversions. In particular, we suggest that the tropospheric phase lag error leads to large misdiagnoses of wetland emissions in the high latitudes of the Northern Hemisphere.

Technical advance: identification of plant actin-binding proteins by F-actin affinity chromatography

NASA Technical Reports Server (NTRS)

Hu, S.; Brady, S. R.; Kovar, D. R.; Staiger, C. J.; Clark, G. B.; Roux, S. J.; Muday, G. K.

2000-01-01

Proteins that interact with the actin cytoskeleton often modulate the dynamics or organization of the cytoskeleton or use the cytoskeleton to control their localization. In plants, very few actin-binding proteins have been identified and most are thought to modulate cytoskeleton function. To identify actin-binding proteins that are unique to plants, the development of new biochemical procedures will be critical. Affinity columns using actin monomers (globular actin, G-actin) or actin filaments (filamentous actin, F-actin) have been used to identify actin-binding proteins from a wide variety of organisms. Monomeric actin from zucchini (Cucurbita pepo L.) hypocotyl tissue was purified to electrophoretic homogeneity and shown to be native and competent for polymerization to actin filaments. G-actin, F-actin and bovine serum albumin affinity columns were prepared and used to separate samples enriched in either soluble or membrane-associated actin-binding proteins. Extracts of soluble actin-binding proteins yield distinct patterns when eluted from the G-actin and F-actin columns, respectively, leading to the identification of a putative F-actin-binding protein of approximately 40 kDa. When plasma membrane-associated proteins were applied to these columns, two abundant polypeptides eluted selectively from the F-actin column and cross-reacted with antiserum against pea annexins. Additionally, a protein that binds auxin transport inhibitors, the naphthylphthalamic acid binding protein, which has been previously suggested to associate with the actin cytoskeleton, was eluted in a single peak from the F-actin column. These experiments provide a new approach that may help to identify novel actin-binding proteins from plants.

Technical advance: identification of plant actin-binding proteins by F-actin affinity chromatography.

PubMed

Hu, S; Brady, S R; Kovar, D R; Staiger, C J; Clark, G B; Roux, S J; Muday, G K

2000-10-01

Proteins that interact with the actin cytoskeleton often modulate the dynamics or organization of the cytoskeleton or use the cytoskeleton to control their localization. In plants, very few actin-binding proteins have been identified and most are thought to modulate cytoskeleton function. To identify actin-binding proteins that are unique to plants, the development of new biochemical procedures will be critical. Affinity columns using actin monomers (globular actin, G-actin) or actin filaments (filamentous actin, F-actin) have been used to identify actin-binding proteins from a wide variety of organisms. Monomeric actin from zucchini (Cucurbita pepo L.) hypocotyl tissue was purified to electrophoretic homogeneity and shown to be native and competent for polymerization to actin filaments. G-actin, F-actin and bovine serum albumin affinity columns were prepared and used to separate samples enriched in either soluble or membrane-associated actin-binding proteins. Extracts of soluble actin-binding proteins yield distinct patterns when eluted from the G-actin and F-actin columns, respectively, leading to the identification of a putative F-actin-binding protein of approximately 40 kDa. When plasma membrane-associated proteins were applied to these columns, two abundant polypeptides eluted selectively from the F-actin column and cross-reacted with antiserum against pea annexins. Additionally, a protein that binds auxin transport inhibitors, the naphthylphthalamic acid binding protein, which has been previously suggested to associate with the actin cytoskeleton, was eluted in a single peak from the F-actin column. These experiments provide a new approach that may help to identify novel actin-binding proteins from plants.

Void fraction, bubble size and interfacial area measurements in co-current downflow bubble column reactor with microbubble dispersion

DOE PAGES

Hernandez-Alvarado, Freddy; Kalaga, Dinesh V.; Turney, Damon; ...

2017-05-06

Micro-bubbles dispersed in bubble column reactors have received great interest in recent years, due to their small size, stability, high gas-liquid interfacial area concentrations and longer residence times. The high gas-liquid interfacial area concentrations lead to high mass transfer rates compared to conventional bubble column reactors. In the present work, experiments have been performed in a down-flow bubble column reactor with micro-bubbles generated and dispersed by a novel mechanism to determine the gas-liquid interfacial area concentrations by measuring the void fraction and bubble size distributions. Gamma-ray densitometry has been employed to determine the axial and radial distributions of void fractionmore » and a high speed camera equipped with a borescope is used to measure the axial and radial variations of bubble sizes. Also, the effects of superficial gas and liquid velocities on the two-phase flow characteristics have been investigated. Further, reconstruction techniques of the radial void fraction profiles from the gamma densitometry's chordal measurements are discussed and compared for a bubble column reactor with dispersed micro-bubbles. The results demonstrate that the new bubble generation technique offers high interfacial area concentrations (1,000 to 4,500 m 2/m 3) with sub-millimeter bubbles (500 to 900 µm) and high overall void fractions (10% – 60%) in comparison with previous bubble column reactor designs. The void fraction data was analyzed using slip velocity model and empirical correlation has been proposed to predict the Sauter mean bubble diameter.« less

Void fraction, bubble size and interfacial area measurements in co-current downflow bubble column reactor with microbubble dispersion

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

Hernandez-Alvarado, Freddy; Kalaga, Dinesh V.; Turney, Damon

Micro-bubbles dispersed in bubble column reactors have received great interest in recent years, due to their small size, stability, high gas-liquid interfacial area concentrations and longer residence times. The high gas-liquid interfacial area concentrations lead to high mass transfer rates compared to conventional bubble column reactors. In the present work, experiments have been performed in a down-flow bubble column reactor with micro-bubbles generated and dispersed by a novel mechanism to determine the gas-liquid interfacial area concentrations by measuring the void fraction and bubble size distributions. Gamma-ray densitometry has been employed to determine the axial and radial distributions of void fractionmore » and a high speed camera equipped with a borescope is used to measure the axial and radial variations of bubble sizes. Also, the effects of superficial gas and liquid velocities on the two-phase flow characteristics have been investigated. Further, reconstruction techniques of the radial void fraction profiles from the gamma densitometry's chordal measurements are discussed and compared for a bubble column reactor with dispersed micro-bubbles. The results demonstrate that the new bubble generation technique offers high interfacial area concentrations (1,000 to 4,500 m 2/m 3) with sub-millimeter bubbles (500 to 900 µm) and high overall void fractions (10% – 60%) in comparison with previous bubble column reactor designs. The void fraction data was analyzed using slip velocity model and empirical correlation has been proposed to predict the Sauter mean bubble diameter.« less

On the accuracy of various large axial displacement formulae for crooked columns

NASA Astrophysics Data System (ADS)

Mallis, J.; Kounadis, A. N.

1988-11-01

The axial displacements of an initially crooked, simply supported column, subjected to an axial compressive force at its end, are determined by using several variants of the axial strain-displacement relationship. Their accuracy and range of applicability are thoroughly discussed by comparing the corresponding results with those of the exact elastica analysis in which the compressibility effect of the bar axis is accounted for. Among other findings, the important conclusion is drawn that the simplified linear kinematic relation leads to a sufficiently accurate evaluation of the initial part of the postbuckling path which is of significant importance for structural design purposes.

I(CO)/N(H2) conversions and molecular gas abundances in spiral and irregular galaxies

NASA Technical Reports Server (NTRS)

Maloney, Philip; Black, John H.

1988-01-01

Observations of emission in the J = 1-0 rotational transition of interstellar CO are used to obtain column densities and masses of hydrogen. By taking into account the effects of variations in molecular cloud parameters on conversion factors between integrated CO intensity and molecular hydrogen column density, it is shown that conversion factors are very sensitive to the kinetic temperature of the emitting gas. Results indicate that the gas temperatures in systems with high star formation rates can be quite high, and it is suggested that use of a standard conversion factor will lead to systematic overestimation of the amount of molecular gas.

Methanogenesis acceleration of fresh landfilled waste by micro-aeration.

PubMed

Shao, Li-Ming; He, Pin-Jing; Zhang, Hua; Yu, Xiao-Hua; Li, Guo-Jian

2005-01-01

When municipal solid waste (MSW) with high content of food waste is landfilled, the rapid hydrolysis of food waste results in the imbalance of anaerobic metabolism in the landfill layer, indicated by accumulation of volatile fatty acids (VFA) and decrease of pH value. This occurrence could lead to long lag time before the initiation of methanogenesis and to the production of strong leachate. Simulated landfill columns with forced aeration, with natural ventilation, and with no aeration, were monitored regarding their organics degradation rate with leachate recirculation. Hydrolysis reactions produced strong leachate in the column with no aeration. With forced aeration, the produced VFA could be effectively degraded, leading to the reduction in COD of the leachate effluent since the week 3. The CH4 in the landfill gas from the column with aeration rate of 0.39 m3/(m3 x d) and frequency of twice/d, leachate recirculation rate of 12.2 mm/d and frequency of twice/d, could amount to 40% (v/v) after only 20 weeks. This amount had increased up to 50% afterward even with no aeration. Most of COD in the recirculated leachate was removed. Using natural ventilation, CH4 could also be produced and the COD of the leachate effluent be reduced after 10 weeks of operation. However, the persistent existence of oxygen in the landfill layer yielded instability in methanogenesis process.

Microbial nitrogen sinks in the water column of a large coastal hypoxic area, the Gulf of Mexico "Dead Zone"

NASA Astrophysics Data System (ADS)

Rogener, M. K.; Roberts, B. J.; Rabalais, N. N.; Stewart, F. J.; Joye, S. B.

2016-02-01

Excess nitrogen in coastal environments leads to eutrophication, harmful algal blooms, habitat loss, oxygen depletion and reductions in biodiversity. As such, biological nitrogen (N) removal through the microbially-mediated process of denitrification is a critical ecosystem function that can mitigate the negative consequences of excess nitrogen loading. However, denitrification can produce nitrous oxide, a potent greenhouse gas, as a byproduct under some environmental conditions. To understand how excess nitrogen loading impacts denitrification, we measured rates of this process in the water column of the Gulf of Mexico "Dead Zone" three times over the summer of 2015. The Dead Zone is generated by excessive nitrogen loading from the Mississippi River co-occurring with strong water column stratification, which leads to a large summer-time hypoxic/anoxic area at the mouth of the river and along the coast of Louisiana. Rates of denitrification ranged from 31 to 153 nmol L-1 d-1. Dead Zone waters are also enriched in methane and aerobic methane oxidation rates ranged from 0.1 to 4.3 nmol L-1 d-1. Maximal denitrification rates were observed at stations with the lowest oxygen concentrations and highest methane oxidation rates, suggesting a potential coupling between nitrate reduction and methane oxidation which both scrubs reactive N and methane from the system, thus performing a duel ecosystem service.

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

NASA Astrophysics Data System (ADS)

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.

Top 50 most cited articles on primary tumors of the spine.

PubMed

Alan, Nima; Cohen, Jonathan; Ozpinar, Alp; Agarwal, Nitin; Kanter, Adam S; Okonkwo, David O; Hamilton, D Kojo

2017-08-01

Citation analysis was performed in order to identify the top 50 most cited articles pertaining to the field of primary spinal tumors. This collection of articles highlights important trends in the neurosurgical literature. We searched the Thomson Reuters Web of Knowledge in order to identify articles pertaining to primary tumors of the spine. Impertinent articles were removed. The top 50 most cited articles were identified. Thereafter, article characteristics were determined including article type, article topic, level of evidence, and citation rate. The selected articles were published between 1951 and 2008. The most productive year was 1997 with 6 publications. The top 50 articles were published in twenty-two different journals, most commonly in Neurosurgery (12), Journal of Neurosurgery (8), and Spine (6). The most frequently cited article was by Tomita et al. written in 1997 which described total en bloc spondylectomy as a novel surgical technique in management of primary tumors of the vertebral column. We identified the 50 most-cited articles in the field of primary spinal tumors. This collection of articles serves as a reference for recognizing impactful studies in the field. Copyright © 2017. Published by Elsevier Ltd.

Characterizing fluid dynamics in a bubble column aimed for the determination of reactive mass transfer

NASA Astrophysics Data System (ADS)

Kováts, Péter; Thévenin, Dominique; Zähringer, Katharina

2018-02-01

Bubble column reactors are multiphase reactors that are used in many process engineering applications. In these reactors a gas phase comes into contact with a fluid phase to initiate or support reactions. The transport process from the gas to the liquid phase is often the limiting factor. Characterizing this process is therefore essential for the optimization of multiphase reactors. For a better understanding of the transfer mechanisms and subsequent chemical reactions, a laboratory-scale bubble column reactor was investigated. First, to characterize the flow field in the reactor, two different methods have been applied. The shadowgraphy technique is used for the characterisation of the bubbles (bubble diameter, velocity, shape or position) for various process conditions. This technique is based on particle recognition with backlight illumination, combined with particle tracking velocimetry (PTV). The bubble trajectories in the column can also be obtained in this manner. Secondly, the liquid phase flow has been analysed by particle image velocimetry (PIV). The combination of both methods, delivering relevant information concerning disperse (bubbles) and continuous (liquid) phases, leads to a complete fluid dynamical characterization of the reactor, which is the pre-condition for the analysis of mass transfer between both phases.

A macro-enzyme cause of an isolated increase of alkaline phosphatase.

PubMed

Cervinski, Mark A; Lee, Hong Kee; Martin, Isabella W; Gavrilov, Dimitar K

2015-02-02

Macroenzyme complexes of serum enzymes and antibody can increase the circulating enzymatic activity and may lead to unnecessary additional testing and procedures. Laboratory physicians and scientists need to be aware of techniques to identify macroenzyme complexes when suspected. To investigate the possibility of a macro-alkaline phosphatase in the serum of a 74 year old male with persistently increased alkaline phosphatase we coupled a protein A/G agarose affinity chromatography technique with isoenzyme electrophoresis to look for the presence of macro-alkaline phosphatase. The majority of the alkaline phosphatase activity in the patient's serum sample was bound to the column and only a minor fraction (25%) of alkaline phosphatase activity was present in the column flow-through. The alkaline phosphatase activity was also found to co-elute with the immunoglobulins in the patient sample. The alkaline phosphatase activity in a control serum sample concurrently treated in the same manner did not bind to the column and was found in the column flow-through. The use of protein A/G agarose affinity chromatography is a rapid and simple method that can be applied to the investigation of other macro-enzyme complexes. Copyright © 2014 Elsevier B.V. All rights reserved.

Column leaching and sorption experiments to assess the mobility of potentially toxic elements in industrially contaminated land.

PubMed

Anderson, P; Davidson, C M; Duncan, A L; Littlejohn, D; Ure, A M; Garden, L M

2000-06-01

Made-up ground collected from layers of a trial pit excavated on a former industrial site was treated with artificial rainwater in a series of column leaching and sorption experiments. Metal mobility and the ability of various layers of material obtained from the pit to act as sources or sinks of potentially toxic elements were assessed. Samples from different layers varied in their abilities to raise the pH of rainwater applied at pH 3.5 and 4.3, and this was reflected in the amounts of metals mobilised by the rainwater as it percolated through the soil column. Material from the top two layers of the pit released cadmium, copper, manganese, lead, nickel and zinc to the aqueous phase, but the lower layers, with higher buffering capacity, were able to resist acidification even when the equivalent of 12 months' rainfall (western UK) was applied. Column sorption experiments confirmed the ability of material from layer 4 (48-50 cm) to take up copper, manganese and zinc. Metals were determined in the leachates by flame and electrothermal atomic absorption spectrometry and principle anions by ion chromatography.

Plastic buckling. [post-bifurcation and imperfection sensitivity

NASA Technical Reports Server (NTRS)

Hutchinson, J. W.

1974-01-01

The present article is concerned mainly with the post-bifurcation and imperfection-sensitivity aspects of plastic buckling. A simple two-degree-of-freedom model is used to introduce post-bifurcation behavior and a second model illustrates features of the behavior of continuous solids and structures. Hill's bifurcation criterion for a class of three-dimensional solids is applied to the Donnell-Mushtari-Vlasov (DMV) theory of plates and shells. A general treatment of the initial post-bifurcation behavior of plates and shells is given within the context of the DMV theory. This is illustrated by problems involving columns and circular plates under radial compression. Numerical results are given for a column under axial compression, a circular plate under radial compression, and spherical and cylindrical shells.

Sur le flambage plastique de l'éprouvette cruciformeAbout the plastic buckling of the cruciform column

NASA Astrophysics Data System (ADS)

Cimetière, Alain; Léger, Alain; Potier-Ferry, Michel

2004-01-01

We build a rate potential through the introduction of several behavior assumptions, of which we discuss the physical meaning. Inserted into the quasi-static equations, this potential allows us to revisit the generic problem of the plastic buckling of the cruciform column. We get an interval on the parameter axis of which any point is a bifurcation point. This result is qualitatively interesting from the point of view of spectral analysis, as the existence of such a continuum was up to now related to discontinuities in the constitutive law, while everything is very smooth in the present case. To cite this article: A. Cimetière et al., C. R. Mecanique 332 (2004).

HIGH-SPEED GC/MS FOR AIR ANALYSIS

EPA Science Inventory

High speed or fast gas chromatography (FGC) consists of narrow bandwidth injection into a high-speed carrier gas stream passing through a short column leading to a fast detector. Many attempts have been made to demonstrate FGC, but until recently no practical method for routin...

Research and Policy: Can Online Learning Communities Foster Professional Development?

ERIC Educational Resources Information Center

Beach, Richard

2012-01-01

This column posits enhancing professional development through uses of digital tools to create professional learning communities (PLCs) designed to support collective inquiry and action research leading to schoolwide improvement. These digital tools include a social networking/discussion forum for teacher collaboration; teachers' individual…

Is political behavior a viable coping strategy to perceived organizational politics? Unveiling the underlying resource dynamics.

PubMed

Sun, Shuhua; Chen, Huaizhong

2017-10-01

[Correction Notice: An Erratum for this article was reported in Vol 102(10) of Journal of Applied Psychology (see record 2017-34254-001). In the article, Table 1 contained a formatting error. Correlation coefficient values in the last four cells of column 6 were misplaced with correlation coefficient values in the last four cells of column 7. All versions of this article have been corrected.] We conduct a theory-driven empirical investigation on whether political behavior, as a coping strategy to perceived organizational politics, creates resource trade-offs in moderating the relationship between perceived organizational politics and task performance. Drawing on conservation of resources theory, we hypothesize that political behavior mitigates the adverse effect of perceived organizational politics on task performance via psychological empowerment, yet exacerbates its adverse effect on task performance via emotional exhaustion. Three-wave multisource data from a sample of 222 employees and their 75 supervisors were collected for hypothesis testing. Findings supported our hypotheses. Our study enhances understandings of the complex resource dynamics of using political behavior to cope with perceived organizational politics and highlights the need to move stress-coping research from a focus on the stress-buffering effect of coping on outcomes to a focus on the underlying competing resource dynamics. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

Enzymic Synthesis of Indole-3-Acetyl-1-O-β-d-Glucose 1

PubMed Central

Leznicki, Antoni J.; Bandurski, Robert S.

1988-01-01

The first enzyme-catalyzed reaction leading from indole-3-acetic acid (IAA) to the myo-inositol esters of IAA is the synthesis of indole-3-acetyl-1-O-β-d-glucose from uridine-5′-diphosphoglucose (UDPG) and IAA. The reaction is catalyzed by the enzyme, UDPG-indol-3-ylacetyl glucosyl transferase (IAA-glucose-synthase). This work reports methods for the assay of the enzyme and for the extraction and partial purification of the enzyme from kernels of Zea mays sweet corn. The enzyme has an apparent molecular weight of 46,500 an isoelectric point of 5.5, and its pH optimum lies between 7.3 and 7.6. The enzyme is stable to storage at zero degrees but loses activity during column chromatographic procedures which can be restored only fractionally by addition of column eluates. The data suggest either multiple unknown cofactors or conformational changes leading to activity loss. Images Fig. 4 PMID:11537438

Enzymic synthesis of indole-3-acetyl-1-O-beta-d-glucose. I. Partial purification and characterization of the enzyme from Zea mays

NASA Technical Reports Server (NTRS)

Leznicki, A. J.; Bandurski, R. S.

1988-01-01

The first enzyme-catalyzed reaction leading from indole-3-acetic acid (IAA) to the myo-inositol esters of IAA is the synthesis of indole-3-acetyl-1-O-beta-D-glucose from uridine-5'-diphosphoglucose (UDPG) and IAA. The reaction is catalyzed by the enzyme, UDPG-indol-3-ylacetyl glucosyl transferase (IAA-glucose-synthase). This work reports methods for the assay of the enzyme and for the extraction and partial purification of the enzyme from kernels of Zea mays sweet corn. The enzyme has an apparent molecular weight of 46,500 an isoelectric point of 5.5, and its pH optimum lies between 7.3 and 7.6. The enzyme is stable to storage at zero degrees but loses activity during column chromatographic procedures which can be restored only fractionally by addition of column eluates. The data suggest either multiple unknown cofactors or conformational changes leading to activity loss.

Vortex formation through inertial wave focusing

NASA Astrophysics Data System (ADS)

Duran-Matute, Matias; Flor, Jan-Bert; Godeferd, Fabien

2011-11-01

We present a novel experimental and numerical study on the formation of columnar vortical structures by inertial waves in a rotating fluid. Two inertial-wave cones are generated by a vertically oscillating torus in a fluid in solid body rotation At the tip of the cones, there is a singular point towards which the energy of the waves gets focused. The particularity of this configuration, as compared to those of previous experiments (e.g. oscillating sphere or disc), is that the singular point's position within the fluid leads to complex non-linear wave interaction, which may lead to the formation of a localized vortex that expands in the vertical in the form of a Taylor column. Using detailed PIV measurements we consider the flow evolution from the localized wave overturning motion to the Taylor column formation as well as the inertial wave dynamics during this process, The results are discussed in the context of turbulence in rotating fluids. We acknowledge financial support from projects ANR ANISO and CIBLE.

Electrode alignment of transverse tripoles using a percutaneous triple-lead approach in spinal cord stimulation

NASA Astrophysics Data System (ADS)

Sankarasubramanian, V.; Buitenweg, J. R.; Holsheimer, J.; Veltink, P.

2011-02-01

The aim of this modeling study is to determine the influence of electrode alignment of transverse tripoles on the paresthesia coverage of the pain area in spinal cord stimulation, using a percutaneous triple-lead approach. Transverse tripoles, comprising a central cathode and two lateral anodes, were modeled on the low-thoracic vertebral region (T10-T12) using percutaneous triple-lead configurations, with the center lead on the spinal cord midline. The triple leads were oriented both aligned and staggered. In the staggered configuration, the anodes were offset either caudally (caudally staggered) or rostrally (rostrally staggered) with respect to the midline cathode. The transverse tripolar field steering with the aligned and staggered configurations enabled the estimation of dorsal column fiber thresholds (IDC) and dorsal root fiber thresholds (IDR) at various anodal current ratios. IDC and IDR were considerably higher for the aligned transverse tripoles as compared to the staggered transverse tripoles. The aligned transverse tripoles facilitated deeper penetration into the medial dorsal columns (DCs). The staggered transverse tripoles always enabled broad and bilateral DC activation, at the expense of mediolateral steerability. The largest DC recruited area was obtained with the rostrally staggered transverse tripole. Transverse tripolar geometries, using percutaneous leads, allow for selective targeting of either medial or lateral DC fibers, if and only if the transverse tripole is aligned. Steering of anodal currents between the lateral leads of the staggered transverse tripoles cannot target medially confined populations of DC fibers in the spinal cord. An aligned transverse tripolar configuration is strongly recommended, because of its ability to provide more post-operative flexibility than other configurations.

Optical absorption enhancement in NH2CH=NH2PbI3 lead halide perovskite solar cells with nanotextures

NASA Astrophysics Data System (ADS)

Xie, Ziang; Sun, Shuren; Xie, Xixi; Hou, Ruixiang; Xu, Wanjin; Li, Yanping; Qin, G. G.

2018-01-01

This article reports, for the first time to our knowledge, that the power conversion efficiencies (PCEs) of planar NH2CH=NH2PbI3 (FAPbI3) lead halide perovskite solar cells (SCs) can be largely improved by fabricating nanotextures on the SC surface. Four kinds of nanotextures are investigated and compared with each other: column hollow (CLH) nanoarrays, cone hollow (CNH) nanoarrays, square prism hollow (SPH) nanoarrays, and pyramid hollow (PYH) nanoarrays. Compared with the PCEs of the planar SCs with the same layer depth d, it is found that when d is in the range of 125-500 nm and when the array period, as well as the filling fraction of the nanotexture, are optimized, the ultimate efficiency increased 29%-50% for the CLH and SPH textured FAPbI3 SCs relative to the planar ones, and 20%-41% for the CNH and PYH textured FAPbI3 SCs relative to the planar ones. When d < 250 nm, the optimized ultimate efficiencies of the CLH and SPH textured FAPbI3 SCs with optimized nanotextures are higher than those of the CNH and PYH ones, and vice versa. The reasons why fabricating nanotextures on SC surfaces can largely improve the PCE of the FAPbI3 SCs are discussed.

Case Study: What Makes a Good Case, Revisited: The Survey Monkey Tells All

ERIC Educational Resources Information Center

Herried, Clyde Freeman; Prud'homme-Genereux, Annie; Schiller, Nancy A.; Herreid, Ky F.; Wright, Carolyn

2016-01-01

This column provides original articles on innovations in case study teaching, assessment of the method, as well as case studies with teaching notes. In this month's issue the authors provide a more definitive answer to the "What Makes a Good Case?" question based on a just-completed Survey Monkey survey given to NCCSTS teachers.

Gardner's Two Children Problems and Variations: Puzzles with Conditional Probability and Sample Spaces

ERIC Educational Resources Information Center

Taylor, Wendy; Stacey, Kaye

2014-01-01

This article presents "The Two Children Problem," published by Martin Gardner, who wrote a famous and widely-read math puzzle column in the magazine "Scientific American," and a problem presented by puzzler Gary Foshee. This paper explains the paradox of Problems 2 and 3 and many other variations of the theme. Then the authors…

Technology: Digital Photography in an Inner-City Fifth Grade, Part 1

ERIC Educational Resources Information Center

Riner, Phil

2005-01-01

Research tells us we can learn complex tasks most easily if they are taught in "small sequential steps." This column is about the small sequential steps that unlocked the powers of digital photography, of portraiture, and of student creativity. The strategies and ideas described in this article came as a result of working with…

Close Reading of Literary Nonfiction: The Three-Column Journal

ERIC Educational Resources Information Center

McConn, Matthew

2018-01-01

The Common Core State Standards have placed more emphasis on the close reading of all texts, and have made a point of increasing the use of nonfiction in secondary English classrooms. In this article, the author describes an approach for implementing close reading of literary nonfiction. The approach comes from a small-scale classroom-based…

ARL: A Bimonthly Newsletter of Research Library Issues and Actions, 1996.

ERIC Educational Resources Information Center

Barrett, G. Jaia, Ed.

1996-01-01

This document contains 6 issues (one year) of a newsletter devoted to information and reports on issues and actions of interest to research libraries. Each issue contains articles on current issues, federal relations, ARL activities, and a calendar of events, as well as columns by the Coalition for Networked Information and the Office of…

Round and Round

ERIC Educational Resources Information Center

Damonte, Kathleen

2004-01-01

A tornado is a rotating, funnel-shaped column of air, which extends from a thunderstorm to the ground. The winds of a tornado can reach up to 480 km per hour. This is about five times faster than a car driving on a highway. Tornadoes can be almost invisible until they pick up dust and debris. This article describes an activity that stimulates…

International trends in health science librarianship part 20: Russia.

PubMed

Murphy, Jeannette; Jargin, Serge

2017-03-01

This is the last in a series of articles exploring international trends in health science librarianship in the 21st century. The focus of the present issue is Russia. The next feature column will initiate a new series entitled New Directions in Health Science Librarianship. The first contribution will be from Australia. JM. © 2017 Health Libraries Group.

Hot under the Collar: Weighing the Dangers of a Weight-Loss Drug

ERIC Educational Resources Information Center

DeSimone, Susan M.; Genereux, Annie Prud'homme

2011-01-01

This column provides original articles on innovations in case study teaching, assessment of the method, as well as case studies with teaching notes. In this month's issue the goal of the case study is for students to expand their understanding of membrane permeability and the proton motive force in mitochondria through the study of…

Back to Basics: Building from the Ground up

ERIC Educational Resources Information Center

Woerner, Ali, Ed.

2010-01-01

In this first article as the new editor of this column, the author discusses issues in the private sector for students with goals of pursuing degrees in higher education and aspirations for performance careers. She is well aware that several areas comprise teaching in the private sector, many of which focus on far different goals than these. She…

Placed on a Pedestal: Famous Faces in Clay

ERIC Educational Resources Information Center

Walkup, Nancy

2010-01-01

Artists have created portraits of people for thousands of years. In sculpture, a portrait of a person's face often includes the neck and part of the shoulders and chest. These artworks are called portrait busts. In this article, the author describes how her fifth-grade students created clay portrait busts on pedestal columns. The objectives are…

Bewitching Ideas Influence Learning: An Evaluation of an Interdisciplinary Teaching Experience

ERIC Educational Resources Information Center

Nava-Whitehead, Susan M.; Augusto, Kerri W.; Gow, Joan-Beth

2011-01-01

This column provides original articles on innovations in case study teaching, assessment of the method, as well as case studies with teaching notes. In this month's issue the authors describe an interdisciplinary approach to case study teaching that addresses the demand to balance the goals of process and content. The case study, Salem's Secrets…

Critical Literacy as Policy and Advocacy: Lessons from Colombia

ERIC Educational Resources Information Center

Mora, Raúl Alberto

2014-01-01

This article, the first column for this issue's Policy and Advocacy department, features a discussion about a recent experience in a graduate program in Medellín, Colombia introducing students to critical literacy. Graduate students used ideas from critical literacy to engage in an in-depth analysis of textbooks they had used in their practice.…

The Best of the Recent Literature Focusing on the User

ERIC Educational Resources Information Center

Voeller, Stacy L.

2008-01-01

The author's focus for this column within the large universe of the public services literature is on articles which stress what is best for the user. That may mean finding out why faculty use or do not use the physical library, considering the elimination of the reference desk, beginning or enhancing a library's virtual reference services, or…

An Integrative Lesson on Searching, Tracking Citations, and Evaluating a Scholarly Article

ERIC Educational Resources Information Center

Ragains, Patrick

2013-01-01

In this column, the author discusses a lesson in the credit-bearing information literacy course for honors undergraduates at the University of Nevada, Reno (UNR). The lesson comes last in a unit including resource instruction, search practice, and culminating in the reading and evaluation of a scholarly work. The course, Honors 235: Research in…

Classic of the Month. [Columns Compiled from Three Issues of "Notes Plus," September 1983 to January 1984.

ERIC Educational Resources Information Center

Notes Plus, 1984

1984-01-01

Three installments of "Classic of the Month," a regular feature of the National Council of Teachers of English publication, "Notes Plus," are presented in this compilation. Each installment of this feature is intended to provide teaching ideas related to a "classic" novel. The first article offers a variety of…

Should Rewards Have a Place in Early Childhood Programs?

ERIC Educational Resources Information Center

Shiller, Virginia M.; O'Flynn, Janet C.; Reineke, June; Sonsteng, Kathleen; Gartrell, Dan

2008-01-01

Does the use of rewards to motivate children to learn or to follow classroom rules run counter to fostering a true desire for mastery? This column, which consists of two separate articles, provides the opposing opinions of the authors regarding the appropriateness of giving rewards in an early childhood classroom. In "Using Rewards in the Early…

Comedy Stages, Poets Projects, Sports Columns, and Kinesiology 341: Illuminating the Importance of Basic Writers' Self-Sponsored Literacies

ERIC Educational Resources Information Center

Roozen, Kevin

2012-01-01

Dominant perspectives of basic writers' self-sponsored literacies tend to overlook the important roles such activities can play in literate development. Drawn from texts, interviews, and participant-observations collected during a five-year study, this article continues the examination of the relationship between one writer's curricular and…

Erratum: Analogous intruder behavior near Ni, Sn, and Pb isotopes [Phys. Rev. C 92, 024319 (2015)

DOE PAGES

Liddick, S. N.; Walters, W. B.; Chiara, C. J.; ...

2016-12-30

Here, the interpretation of neutron knockout reactions leading to 69Ni, a transcription error was discovered in the third column of Table I in the original paper, reporting the absolute γ -ray intensities of transitions in 69Ni.

Supporting Sustained Engagements with Texts

ERIC Educational Resources Information Center

Asselin, Marlene

2004-01-01

This column focuses on reading engagement by first discussing the concept then suggesting ways that teacher-librarians can lead initiatives in their schools towards this goal. While the concepts: (1) reading engagement; (2) motivation to read; and (3) interest and voluntary reading are interconnected, it is important to understand their…

Stable lead isotopic analyses of historic and contemporary lead contamination of San Francisco Bay estuary

USGS Publications Warehouse

Ritson, P.I.; Bouse, R.M.; Flegal, A.R.; Luoma, S.N.

1999-01-01

Variations in stable lead isotopic composition (240Pb, 206Pb, 207Pb, 208Pb) in three sediment cores from the San Francisco Bay estuary document temporal changes in sources of lead during the past two centuries. Sediment, with lead from natural geologic sources, and relatively homogeneous lead isotopic compositions are overlain by sediments whose isotopic compositions indicate change in the sources of lead associated with anthropogenic modification of the estuary. The first perturbations of lead isotopic composition in the cores occur in the late 1800s concordant with the beginning of industrialization around the estuary. Large isotopic shifts, toward lower 206Pb/207Pb, occur after the turn of the century in both Richardson and San Pablo Bays. A similar relationship among lead isotopic compositions and lead concentrations in both Bays suggest contamination from the same source (a lead smelter). The uppermost sediments (post 1980) of all cores also have a relatively homogenous lead isotopic composition distinct from pre-anthropogenic and recent aerosol signatures. Lead isotopic compositions of leachates from fourteen surface sediments and five marsh samples from the estuary were also analyzed. These analyses suggest that the lead isotopic signature identified in the upper horizons of the cores is spatially homogeneous among recently deposited sediments throughout the estuary. Current aerosol lead isotopic compositions [Smith, D.R., Niemeyer, S., Flegal, A.R., 1992. Lead sources to California sea otters: industrial inputs circumvent natural lead biodepletion mechanisms. Environmental Research 57, 163-175] are distinct from the isotopic compositions of the surface sediments, suggesting that the major source of lead is cycling of historically contaminated sediments back through the water column. Both the upper core sediments and surface sediments apparently derive their lead predominantly from sources internal to the estuary. These results support the idea that geochemical cycling of lead between sediments and water accounts for persistently elevated lead concentrations in the water column despite 10-fold reduction of external source inputs to San Francisco Bay [Flegal, A.R., Rivera-Duarte, I., Ritson, P.I., Scelfo, G., Smith, G.J., Gordon, M., Sanudo-Wilhelmy, S.A., 1996. Metal contamination in San Francisco Waters: historic perturbations, contemporary concentrations, and future considerations in San Francisco Bay. In: Hollobaugh, J.T. (Ed.), The Ecosystem. AAAS, pp. 173-188].

Study on the Alkaloids in Tibetan Medicine Aconitum pendulum Busch by HPLC-MSn Combined with Column Chromatography.

PubMed

Wang, Beibei; Dong, Jie; Ji, Jiaojiao; Yuan, Jiang; Wang, Jiali; Wu, Jiarui; Tan, Peng; Liu, Yonggang

2016-01-01

A rapid, convenient and effective identification method of alkaloids was established and an attempt on isolating and analyzing the alkaloids in Aconitum pendulum Busch was conducted successfully. In this article, four high-content components including deoxyaconitine, benzoylaconine, aconine and neoline were isolated by using column chromatography. HPLC-MS(n)was employed to deduce the regulations of fragmentation of diterpenoid alkaloids which displayed a characteristic behavior of loss of CO(28u), CH3COOH(60u), CH3OH(32u), H2O(18u) and C6H5COOH(122u). Then, according to fragmentation regulation of mass spectrometry, 42 alkaloids were found inA. pendulum Among them, 38 compounds were identified and 29 alkaloids were reported for the first time for this herb. Therefore, this means that HPLC-MS(n)combined with column chromatography could work as an effective and reliable tool for rapid identification of the chemical components of herbal medicine. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Transport of E. coli in a sandy soil as impacted by depth to water table.

PubMed

Stall, Christopher; Amoozegar, Aziz; Lindbo, David; Graves, Alexandria; Rashash, Diana

2014-01-01

Septic systems are considered a source of groundwater contamination. In the study described in this article, the fate of microbes applied to a sandy loam soil from North Carolina coastal plain as impacted by water table depth was studied. Soil materials were packed to a depth of 65 cm in 17 columns (15-cm diameter), and a water table was established at 30, 45, and 60 cm depths using five replications. Each day, 200 mL of an artificial septic tank effluent inoculated with E. coli were applied to the top of each column, a 100-mL sample was collected at the water table level and analyzed for E. coli, and 100 mL was drained from the bottom to maintain the water table. Two columns were used as control and received 200 mL/day of sterilized effluent. Neither 30 nor 45 cm of unsaturated soil was adequate to attenuate bacterial contamination, while 60 cm of separation appeared to be sufficient. Little bacterial contamination moved with the water table when it was lowered from 30 to 60 cm.

Behavior of Double-Web Angles Beam to column connections

NASA Astrophysics Data System (ADS)

Fakih, K. Al; Chin, S. C.; Doh, S. I.

2018-04-01

This paper contains the study performed on the behavior of double-web angles by using finite element analysis computer package known as “Abaqus”. The aim of this present study was simulating the behavior of double-web angles (DWA) steel connections. The purpose of this article is to provide the basis for the fastest and most economical design and analysis and to ensure the required steel connection strength. This study, started used review method of behavior of steel beam-to-column bolted connections. Two models of different cross-section were examined under the effect of concentrated load and different boundary conditions. In all the studied case, material nonlinearity was accounted. A sample study on DWA connections was carried out using both material and geometric nonlinearities. This object will be of great value to anyone who wants to better understand the behavior of the steel beam to column connection. The results of the study have a field of reference for future research for members of the development of the steel connection approach with simulation model design.

Comparison of EDTA and SDS as potential surface impregnation agents for lead adsorption by activated carbon

NASA Astrophysics Data System (ADS)

Chen, Wei-fang; Pan, Ling; Chen, Li-fang; Yu, Zhe; Wang, Qiong; Yan, Chang-cheng

2014-08-01

Ethylene diamine tetraacetic acid (EDTA) and sodium dodecyl sulfate (SDS) were employed to impregnate activated carbons for the purpose of lead removal. The mechanisms of surface impregnation and lead adsorption method of chemical regeneration were investigated. Results showed that the highest impregnation of EDTA and SDS on activated carbon was 0.33 and 0.96 mmol/g, respectively. Adsorption capacities for lead of EDTA and SDS impregnated activated carbons reached 0.29 and 0.24 mmol/g. Rapid small scale column tests of adsorption and regeneration were conducted. Lead adsorption was greatly enhanced by EDTA impregnation. In addition, EDTA impregnated adsorbent was able to be successful regenerated by HNO3 and thus reused.

Coupled Leidenfrost states as a monodisperse granular clock

NASA Astrophysics Data System (ADS)

Liu, Rui; Yang, Mingcheng; Chen, Ke; Hou, Meiying; To, Kiwing

2016-08-01

Using an event-driven molecular dynamics simulation, we show that simple monodisperse granular beads confined in coupled columns may oscillate as a different type of granular clock. To trigger this oscillation, the system needs to be driven against gravity into a density-inverted state, with a high-density clustering phase supported from below by a gaslike low-density phase (Leidenfrost effect) in each column. Our analysis reveals that the density-inverted structure and the relaxation dynamics between the phases can amplify any small asymmetry between the columns, and lead to a giant oscillation. The oscillation occurs only for an intermediate range of the coupling strength, and the corresponding phase diagram can be universally described with a characteristic height of the density-inverted structure. A minimal two-phase model is proposed and a linear stability analysis shows that the triggering mechanism of the oscillation can be explained as a switchable two-parameter Andronov-Hopf bifurcation. Numerical solutions of the model also reproduce similar oscillatory dynamics to the simulation results.

Minimum Energy of Multicomponent Distillation Systems Using Minimum Additional Heat and Mass Integration Sections

DOE PAGES

Jiang, Zheyu; Ramapriya, Gautham Madenoor; Tawarmalani, Mohit; ...

2018-04-20

Heat and mass integration to consolidate distillation columns in a multicomponent distillation configuration can lead to a number of new energy efficient and cost effective configurations. In this paper, we identify a powerful and simple-to-use fact about heat and mass integration. The newly developed heat and mass integrated configurations, which we call as HMP configurations, involve first introducing thermal couplings to all intermediate transfer streams, followed by consolidating columns associated with a lighter pure product reboiler and a heavier pure product condenser. A systematic method of enumerating all HMP configurations is introduced. We compare the energy savings of HMP configurationsmore » with the well-known fully thermally coupled (FTC) configurations. We demonstrate that HMP configurations can have very similar and sometimes even the same minimum total vapor duty requirement as the FTC configuration, while using far less number of column sections, intermediate transfer streams, and thermal couplings than the FTC configurations.« less

Minimum Energy of Multicomponent Distillation Systems Using Minimum Additional Heat and Mass Integration Sections

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

Jiang, Zheyu; Ramapriya, Gautham Madenoor; Tawarmalani, Mohit

Heat and mass integration to consolidate distillation columns in a multicomponent distillation configuration can lead to a number of new energy efficient and cost effective configurations. In this paper, we identify a powerful and simple-to-use fact about heat and mass integration. The newly developed heat and mass integrated configurations, which we call as HMP configurations, involve first introducing thermal couplings to all intermediate transfer streams, followed by consolidating columns associated with a lighter pure product reboiler and a heavier pure product condenser. A systematic method of enumerating all HMP configurations is introduced. We compare the energy savings of HMP configurationsmore » with the well-known fully thermally coupled (FTC) configurations. We demonstrate that HMP configurations can have very similar and sometimes even the same minimum total vapor duty requirement as the FTC configuration, while using far less number of column sections, intermediate transfer streams, and thermal couplings than the FTC configurations.« less

Patterned Disordered Cell Motion Ensures Vertebral Column Symmetry.

PubMed

Das, Dipjyoti; Chatti, Veena; Emonet, Thierry; Holley, Scott A

2017-07-24

The biomechanics of posterior embryonic growth must be dynamically regulated to ensure bilateral symmetry of the spinal column. Throughout vertebrate trunk elongation, motile mesodermal progenitors undergo an order-to-disorder transition via an epithelial-to-mesenchymal transition and sort symmetrically into the left and right paraxial mesoderm. We combine theoretical modeling of cell migration in a tail-bud-like geometry with experimental data analysis to assess the importance of ordered and disordered cell motion. We find that increasing order in cell motion causes a phase transition from symmetric to asymmetric body elongation. In silico and in vivo, overly ordered cell motion converts normal anisotropic fluxes into stable vortices near the posterior tail bud, contributing to asymmetric cell sorting. Thus, disorder is a physical mechanism that ensures the bilateral symmetry of the spinal column. These physical properties of the tissue connect across scales such that patterned disorder at the cellular level leads to the emergence of organism-level order. Copyright © 2017 Elsevier Inc. All rights reserved.

Multiplexed Oversampling Digitizer in 65 nm CMOS for Column-Parallel CCD Readout

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

Grace, Carl; Walder, Jean-Pierre; von der Lippe, Henrik

2012-04-10

A digitizer designed to read out column-parallel charge-coupled devices (CCDs) used for high-speed X-ray imaging is presented. The digitizer is included as part of the High-Speed Image Preprocessor with Oversampling (HIPPO) integrated circuit. The digitizer module comprises a multiplexed, oversampling, 12-bit, 80 MS/s pipelined Analog-to-Digital Converter (ADC) and a bank of four fast-settling sample-and-hold amplifiers to instrument four analog channels. The ADC multiplexes and oversamples to reduce its area to allow integration that is pitch-matched to the columns of the CCD. Novel design techniques are used to enable oversampling and multiplexing with a reduced power penalty. The ADC exhibits 188more » ?V-rms noise which is less than 1 LSB at a 12-bit level. The prototype is implemented in a commercially available 65 nm CMOS process. The digitizer will lead to a proof-of-principle 2D 10 Gigapixel/s X-ray detector.« less

Transfer of gold nanoparticles from the water column to the estuarine food web

NASA Astrophysics Data System (ADS)

Ferry, John L.; Craig, Preston; Hexel, Cole; Sisco, Patrick; Frey, Rebecca; Pennington, Paul L.; Fulton, Michael H.; Scott, I. Geoff; Decho, Alan W.; Kashiwada, Shosaku; Murphy, Catherine J.; Shaw, Timothy J.

2009-07-01

Within the next five years the manufacture of large quantities of nanomaterials may lead to unintended contamination of terrestrial and aquatic ecosystems. The unique physical, chemical and electronic properties of nanomaterials allow new modes of interaction with environmental systems that can have unexpected impacts. Here, we show that gold nanorods can readily pass from the water column to the marine food web in three laboratory-constructed estuarine mesocosms containing sea water, sediment, sea grass, microbes, biofilms, snails, clams, shrimp and fish. A single dose of gold nanorods (65 nm length × 15 nm diameter) was added to each mesocosm and their distribution in the aqueous and sediment phases monitored over 12 days. Nanorods partitioned between biofilms, sediments, plants, animals and sea water with a recovery of 84.4%. Clams and biofilms accumulated the most nanoparticles on a per mass basis, suggesting that gold nanorods can readily pass from the water column to the marine food web.

Leaching of FGD Byproducts Using a CSTX

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

Kairies, C.L.; Schroeder, K.T.; Cardone, C.R.

2005-09-01

Leaching studies of coal utilization byproducts (CUB) are often performed to determine the compatibility of the material in a particular end-use or disposal environment. Typically, these studies are conducted using either a batch or a fixed-bed column technique. Fixed-bed columns offer the advantage of a continuous flow of effluent that provides elution profiles with changing elution volume and pH. Unfortunately, clogs can form in fixed-bed leaching columns, either because of cementitious properties of the material itself, such as is seen for fluidized bed combustion (FBC) fly ash, or because of precipitate formation, such as can occur when a high-calcium ashmore » is subjected to sulfate-containing leachates. Also, very fine-grained materials, such as gypsum, do not provide sufficient permeability for study in a fixed-bed column. A continuous, stirred-tank extractor (CSTX) is being used as an alternative technique that can provide the elution profile of column leaching but without the low permeability problems. The CSTX has been successfully employed in the leaching of flue gas desulfurization products that would not be sufficiently permeable under traditional column leaching conditions. The results indicate that the leaching behavior depends on a number of factors, including (but not limited to) solubility and neutralization capacity of the mineral phases present, sorption properties of these phases, behavior of the solubilized material in the tank, and the type of species in solution. In addition, leaching to near-exhaustion of a wallboard produced from FGD gypsum has allowed the isolation of a highly adsorptive phase. This phase appears to be present in at least some FGD gypsums and accounts for the immobilization of trace metals such as arsenic, cobalt, lead, and mercury.« less

The effect of dilution and the use of a post-extraction nucleic acid purification column on the accuracy, precision, and inhibition of environmental DNA samples

USGS Publications Warehouse

Mckee, Anna M.; Spear, Stephen F.; Pierson, Todd W.

2015-01-01

Isolation of environmental DNA (eDNA) is an increasingly common method for detecting presence and assessing relative abundance of rare or elusive species in aquatic systems via the isolation of DNA from environmental samples and the amplification of species-specific sequences using quantitative PCR (qPCR). Co-extracted substances that inhibit qPCR can lead to inaccurate results and subsequent misinterpretation about a species’ status in the tested system. We tested three treatments (5-fold and 10-fold dilutions, and spin-column purification) for reducing qPCR inhibition from 21 partially and fully inhibited eDNA samples collected from coastal plain wetlands and mountain headwater streams in the southeastern USA. All treatments reduced the concentration of DNA in the samples. However, column purified samples retained the greatest sensitivity. For stream samples, all three treatments effectively reduced qPCR inhibition. However, for wetland samples, the 5-fold dilution was less effective than other treatments. Quantitative PCR results for column purified samples were more precise than the 5-fold and 10-fold dilutions by 2.2× and 3.7×, respectively. Column purified samples consistently underestimated qPCR-based DNA concentrations by approximately 25%, whereas the directional bias in qPCR-based DNA concentration estimates differed between stream and wetland samples for both dilution treatments. While the directional bias of qPCR-based DNA concentration estimates differed among treatments and locations, the magnitude of inaccuracy did not. Our results suggest that 10-fold dilution and column purification effectively reduce qPCR inhibition in mountain headwater stream and coastal plain wetland eDNA samples, and if applied to all samples in a study, column purification may provide the most accurate relative qPCR-based DNA concentrations estimates while retaining the greatest assay sensitivity.

Mineralogy controls on reactive transport of Marcellus Shale waters.

PubMed

Cai, Zhang; Wen, Hang; Komarneni, Sridhar; Li, Li

2018-07-15

Produced or flowback waters from Marcellus Shale gas extraction (MSWs) typically are highly saline and contain chemicals including trace metals, which pose significant concerns on water quality. The natural attenuation of MSW chemicals in groundwater is poorly understood due to the complex interactions between aquifer minerals and MSWs, limiting our capabilities to monitor and predict. Here we combine flow-through experiments and process-based reactive transport modeling to understand mechanisms and quantify the retention of MSW chemicals in a quartz (Qtz) column, a calcite-rich (Cal) column, and a clay-rich (Vrm, vermiculite) column. These columns were used to represent sand, carbonate, and clay-rich aquifers. Results show that the types and extent of water-rock interactions differ significantly across columns. Although it is generally known that clay-rich media retard chemicals and that quartz media minimize water-rock interactions, results here have revealed insights that differ from previous thoughts. We found that the reaction mechanisms are much more complex than merely sorption and mineral precipitation. In clay rich media, trace metals participate in both ion exchange and mineral precipitation. In fact, the majority of metals (~50-90%) is retained in the solid via mineral precipitation, which is surprising because we typically expect the dominance of sorption in clay-rich aquifers. In the Cal column, trace metals are retained not only through precipitation but also solid solution partitioning, leading to a total of 75-99% retention. Even in the Qtz column, trace metals are retained at unexpectedly high percentages (~20-70%) due to precipitation. The reactive transport model developed here quantitatively differentiates the relative importance of individual processes, and bridges a limited number of experiments to a wide range of natural conditions. This is particularly useful where relatively limited knowledge and data prevent the prediction of complex rock-contaminant interactions and natural attenuation. Copyright © 2018 Elsevier B.V. All rights reserved.

Enhancing Bioremediation of Oil-contaminated Soils by Controlling Nutrient Transport using Dual Characteristics of Soil Pore Structure

NASA Astrophysics Data System (ADS)

Mori, Y.; Suetsugu, A.; Matsumoto, Y.; Fujihara, A.; Suyama, K.; Miyamoto, T.

2012-12-01

Soil structure is heterogeneous with cracks or macropores allowing bypass flow, which may lead to applied chemicals avoiding interaction with soil particles or the contaminated area. We investigated the bioremediation efficiency of oil-contaminated soils by applying suction at the bottom of soil columns during bioremediation. Unsaturated flow conditions were investigated so as to avoid bypass flow and achieve sufficient dispersion of chemicals in the soil column. The boundary conditions at the bottom of the soil columns were 0 kPa and -3 kPa, and were applied to a volcanic ash soil with and without macropores. Unsaturated flow was achieved with -3 kPa and an injection rate of 1/10 of the saturated hydraulic conductivity. The resultant biological activities of the effluent increased dramatically in the unsaturated flow with macropores condition. Unsaturated conditions prevented bypass flow and allowed dispersion of the injected nutrients. Unsaturated flow achieved 60-80% of saturation, which enhanced biological activity in the soil column. Remediation results were better for unsaturated conditions because of higher biological activity. Moreover, unsaturated flow with macropores achieved uniform remediation efficiency from upper through lower positions in the column. Finally, taking the applied solution volume into consideration, unsaturated flow with -3 kPa achieved 10 times higher efficiency when compared with conventional saturated flow application. These results suggest that effective use of nutrients or remediation chemicals is possible by avoiding bypass flow and enhancing biological activity using relatively simple and inexpensive techniques.

Implementation of an MgO-based metal removal step in the passive treatment system of Shilbottle, UK: column experiments.

PubMed

Caraballo, Manuel A; Rötting, Tobias S; Silva, Verónica

2010-09-15

Three laboratory column experiments were performed to test the suitability of two different MgO-rich reagents for removal of Mn and Al from the out-flowing waters of Shilbottle passive treatment system (Northumberland, UK). The input water was doped with 100 mg/L Zn in order to extrapolate results to waters in sulphide mining districts. One column was filled with a Dispersed Alkaline Substrate (DAS) containing 12.5% (v/v) caustic magnesia precipitator dust (CMPD) from Spain mixed with wood shavings, two columns were filled with DAS containing wood shavings and 12.5% or 25% (v/v), respectively, of dolomitic lime precipitator dust (DLPD) from Thrislington, UK. The two columns containing 12.5% of CMPD or DLPD completely removed the contaminants from the inflow water during the first 6 weeks of the experiment (mean removal of 88 mg/L Al, 96 mg/L Zn and 37 mg/L Mn), operating at an acidity load of 140 g acidity/m(2)day. At this moment, a substantial increase of the Al and Mn water concentration in the out-flowing waters of Shilbottle occurred (430 g acidity/m(2)day), leading to passivation of the reactive material and to the development of preferential flow paths within less than another 6 weeks, probably mainly due to Al precipitates. Al should be removed prior to MgO treatment. Copyright 2010 Elsevier B.V. All rights reserved.

Bromate peak distortion in ion chromatography in samples containing high chloride concentrations.

PubMed

Pappoe, Michael K; Naeeni, Mohammad Hosein; Lucy, Charles A

2016-04-29

In this study, the effect of column overload of the matrix ion, chloride, on the elution peak profiles of trace bromate is investigated. The resultant peak profiles of chloride and bromate are explained on the basis of competitive Langmuir isotherms. The Thermo IonPac AS9-HC, AS19 and AS23 columns are recommended by the manufacturer for bromate (a carcinogen) analysis. Under trace conditions, these columns provide baseline resolution of bromate from matrix ions such as chloride (Rs=2.9, 3.3 and 3.2, respectively for the three columns). Injection of 10-300 mM chloride with both hydroxide and carbonate eluents resulted in overload on these columns. On the basis of competitive Langmuir isotherms, a deficiency in the local concentration of the more retained eluent in addition to analyte overload leads to fronting of the overloaded analyte peak. The peak asymmetries (B/A10%) for chloride changed from 1.0 (Gaussian) under trace conditions to 0.7 (fronting) at 300 mM Cl(-) for IonPac AS9-HC, 0.9-0.6 for AS19 and 0.8-0.5, for AS23, respectively. The 10mM bromate peak is initially near Gaussian (B/A10%=0.9) but becomes increasingly distorted and pulled back into the chloride peak as the concentration of chloride increased. Increasing the eluent strength reduced the pull-back effect on bromate and fronting in chloride in all cases. Copyright © 2016 Elsevier B.V. All rights reserved.

A new large-scale process for taxol and related taxanes from Taxus brevifolia.

PubMed

Rao, K V; Hanuman, J B; Alvarez, C; Stoy, M; Juchum, J; Davies, R M; Baxley, R

1995-07-01

In view of the demonstrated antitumor activity of taxol, ready availability of the drug is important. The current isolation methods starting from the bark of Taxus brevifolia involve multiple manipulations, leading to only taxol and in a yield of 0.01%. A new process consisting of a single reverse phase column is introduced here, and the present purpose is to determine its large scale applicability. The chloroform extractable fraction of the bark of T. brevifolia is applied directly on to a C-18 bonded silica column in 25% acetonitrile/water, with elution using a step gradient: 30-50% acetonitrile/water. On standing, eight different taxanes, including taxol, crystallize out directly from different fractions. The crystals are filtered and purified further by recrystallization. Taxol and four other taxanes are purified this way. The other three require a short silica column. Taxol is freed from cephalomannine by selective ozonolysis. The large scale process gave taxol (0.04%), 10-deacetylbaccatin III (0.02%), 10-deacetyl taxol-7-xyloside (0.1%), 10-deacetyl taxol-C-7-xyloside (0.04%), 10-deacetyl cephalomannine-7-xyloside (0.006%), taxol-7-xyloside (0.008%), 10-deacetyl taxol (0.008%) and cephalomannine (0.004%). Processing of the needles of T. brevifolia gave brevifoliol (0.17%), and that of the wood, 10-deacetyl taxol-C-7-xyloside (0.01%) and 10-deacetyl taxol-C. The reverse phase column process is simpler (one column, direct crystallization), more efficient (eight taxanes obtained simultaneously) and also gives higher yields.

Retention of neodymium by dolomite at variable ionic strength as probed by batch and column experiments.

PubMed

Emerson, H P; Zengotita, F; Richmann, M; Katsenovich, Y; Reed, D T; Dittrich, T M

2018-10-01

The results presented in this paper highlight the complexity of adsorption and incorporation processes of Nd with dolomite and significantly improve upon previous work investigating trivalent actinide and lanthanide interactions with dolomite. Both batch and mini column experiments were conducted at variable ionic strength. These data highlight the strong chemisorption of Nd to the dolomite surface (equilibrium K d 's > 3000 mL/g) and suggest that equilibrium adsorption processes may not be affected by ionic strength based on similar results at 0.1 and 5.0 M ionic strength in column breakthrough and equilibrium batch (>5 days) results. Mini column experiments conducted over approximately one year also represent a significant development in measurement of sorption of Nd in the presence of flow as previous large-scale column experiments did not achieve breakthrough likely due to the high loading capacity of dolomite for Nd (up to 240 μg/g). Batch experiments in the absence of flow show that the rate of Nd removal increases with increasing ionic strength (up to 5.0 M) with greater removal at greater ionic strength for a 24 h sampling point. We suggest that the increasing ionic strength induces increased mineral dissolution and re-precipitation caused by changes in activity with ionic strength that lead to increased removal of Nd through co-precipitation processes. Copyright © 2018 Elsevier Ltd. All rights reserved.

Behaviour of square FRP-Confined High-Strength Concrete Columns under Eccentric Compression

NASA Astrophysics Data System (ADS)

Fallah Pour, Ali; Gholampour, Aliakbar; Zheng, Junai; Ozbakkaloglu, Togay

2018-01-01

This paper presents the results of an experimental study on the effect of load eccentricity on the axial compressive behaviour of carbon fibre-reinforced polymer (CFRP)- confined high-strength concrete (HSC) columns with a square cross-section. The axial loading was applied to the specimens at six different load eccentricities ranging from zero to 50 mm. The results show that the load eccentricity significantly influences the axial load-displacement and axial stress-strain behaviour of FRP-confined HSC. Increasing the load eccentricity leads to an increase in the ultimate axial strain but a decrease in the ultimate axial stress and second branch slope of the axial stress-strain curve.

PERFORMANCE OF POLYVINYL ALCOHOL GEL COLUMNS ON THE ION CHROMATOGRAPHIC DETERMINATION OF PERCHLORATE IN FERTILIZERS

EPA Science Inventory

Interest in possible sources of perchlorate (ClO4-) that could lead to environmental release has been heightened since the EPA placed this anion on its Contaminant Candidate List (CCL) for drinking water. Besides its association with defense and aerospace activities, perchlorate ...

Engineering Encounters: An Engineering Design Process for Early Childhood

ERIC Educational Resources Information Center

Lottero-Perdue, Pamela; Bowditch, Michelle; Kagan, Michelle; Robinson-Cheek, Linda; Webb, Tedra; Meller, Megan; Nosek, Theresa

2016-01-01

This column presents ideas and techniques to enhance your science teaching. This month's issue shares information about trying (again) to engineer an egg package. Engineering is an essential part of science education, as emphasized in the "Next Generation Science Standards" (NGSS Lead States 2013). Engineering practices and performance…

Inviting Outsiders inside Disciplinary Literacies: An Interview with Cynthia Greenleaf, Gayle Cribb, and Heather Howlett

ERIC Educational Resources Information Center

Greenleaf, Cynthia; Cribb, Gayle; Howlett, Heather; Moore, David W.

2010-01-01

In this Research Connections column, Editor David Moore interviews Cynthia Greenleaf, Gayle Cribb, and Heather Howlett. Greenleaf codirects the Strategic Literacy Initiative and leads professional development projects in its Reading Apprenticeship instructional framework. Her approach to disciplinary literacy instruction is based on her findings…

E. coli transport from bottom sediments to the stream water column in base flow conditions

USDA-ARS?s Scientific Manuscript database

E. coli as an indicator bacterium is commonly used to characterize microbiological water quality, to evaluate surface water sources for microbiological impairment, and to assess management practices that lead to the decrease of pathogens and indicator influx in surface water sources for recreation a...

EFFECTS OF DIETARY COPPER, ZINC, LEAD, CADMIUM, AND ARSENIC ON GROWTH AND SURVIVAL OF JUVENILE FISH USING LIVE FOOD ORGANISMS

EPA Science Inventory

Except for certain organometallic compounds, dietary exposures of aquatic organisms to metal/metalloids have received little regulatory attention. However, various studies have suggested that dietary exposure could be important, especially in areas where current water column conc...

Collinear integration affects visual search at V1.

PubMed

Chow, Hiu Mei; Jingling, Li; Tseng, Chia-huei

2013-08-29

Perceptual grouping plays an indispensable role in figure-ground segregation and attention distribution. For example, a column pops out if it contains element bars orthogonal to uniformly oriented element bars. Jingling and Tseng (2013) have reported that contextual grouping in a column matters to visual search behavior: When a column is grouped into a collinear (snakelike) structure, a target positioned on it became harder to detect than on other noncollinear (ladderlike) columns. How and where perceptual grouping interferes with selective attention is still largely unknown. This article contributes to this little-studied area by asking whether collinear contour integration interacts with visual search before or after binocular fusion. We first identified that the previously mentioned search impairment occurs with a distractor of five or nine elements but not one element in a 9 × 9 search display. To pinpoint the site of this effect, we presented the search display with a short collinear bar (one element) to one eye and the extending collinear bars to the other eye, such that when properly fused, the combined binocular collinear length (nine elements) exceeded the critical length. No collinear search impairment was observed, implying that collinear information before binocular fusion shaped participants' search behavior, although contour extension from the other eye after binocular fusion enhanced the effect of collinearity on attention. Our results suggest that attention interacts with perceptual grouping as early as V1.

Chiral separation of isoxanthohumol and 8-prenylnaringenin in beer, hop pellets, and hops by HPLC with chiral columns.

PubMed

Moriya, Hyuga; Tanaka, Sohei; Iida, Yukari; Kitagawa, Satomi; Aizawa, Sen-Ichi; Taga, Atsushi; Terashima, Hiroyuki; Yamamoto, Atsushi; Kodama, Shuji

2018-05-16

Xanthohumol, isoxanthohumol, and 8-prenylnaringenin in beer, hop, and hop pellet samples were analyzed by HPLC using InertSustain phenyl column and the mobile phase containing 40% methanol and 12% 2-propanol. Fractions of isoxanthohumol and 8-prenylnaringenin obtained by the above HPLC were separately collected. Isoxanthohumol and 8-prenylnaringenin were enantioseparated by HPLC using Chiralcel OD-H column with a mobile phase composed of hexane/ethanol (90/10, v/v) and Chiralpak AD-RH column with a mobile phase composed of methanol/2-propanol/water (40/20/40, v/v/v), respectively. Both of isoxanthohumol and 8-prenylnaringenin from beer, hop, and hop pellet samples were found to be a racemic mixture. This can be explained that the two analytes were produced by non-enzymatic process. The effects of boiling conditions on the conversion of xanthohumol into isoxanthohumol were also studied. A higher concentration of ethanol in heating solvent resulted in a decrease in the conversion ratio and the conversion was stopped by addition of ethanol more than 50% (v/v). The isomerization was significantly affected pH (2-10) and the boiling medium at pH 5 was minimum for the conversion. Therefore, it was suggested that xanthohumol was relatively difficult to convert to isoxanthohumol in wort (pH 5-5.5) during boiling. This article is protected by copyright. All rights reserved.

Copper extraction from ammoniacal medium in a pulsed sieve-plate column with LIX 84-I.

PubMed

Gameiro, M Lurdes F; Machado, Remígio M; Ismael, M Rosinda C; Reis, M Teresa A; Carvalho, Jorge M R

2010-11-15

This article reports on a study of copper removal from ammoniacal aqueous solution (1.0 kg m(-3) Cu, pH 9.5) by liquid-liquid extraction using a pulsed sieve-plate column. The extractant tested was the hydroxyoxime LIX 84-I (2-hydroxy-5-nonylacetophenone oxime) in the aliphatic diluent Shellsol D-70. The results of the pilot plant experiments demonstrated the feasibility of operating the extraction process in this type of column, with efficiencies of copper removal in the range of 90.5-99.5%. Several effects on the column performance were examined, namely the aqueous and organic flow rates and the pulse velocity. The axial dispersion model was applied to simulate the concentration profiles, which reasonably predicted the experimental data. The overall mass transfer coefficient was evaluated from the experimental data and was found to be between 9×10(-6) and 1.2×10(-5) m s(-1). These data were compared with the ones obtained from the resistances in series model, which indicated that the resistance due to chemical reaction was 84-91% of the overall resistance to mass transfer. The extraction using a hollow fiber contactor was also carried out to compare the membrane process performance with the one of conventional process. Copyright © 2010 Elsevier B.V. All rights reserved.

Non-modal analysis of the diocotron instability: Cylindrical geometry

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

Mikhailenko, V. V.; Lee, Hae June; Mikhailenko, V. S.

2013-04-15

The temporal evolution of the linear diocotron instability of the cylindrical annular plasma column is investigated by employing the extension of the shearing modes methodology to the cylindrical geometry. It was obtained that the spatial time-dependent distortion of the electron density initial perturbations by shear flows leads to the non-modal evolution of the potential, which was referred to as the manifestation of the continuous spectrum. The evolution process leads toward the convergence to the phase-locking configuration of the mutually growing normal modes.

Bias, Power, Influence, and Competence: The Implications of Human Nature on the New NIH Conflicts of Interest Regulations

ERIC Educational Resources Information Center

Slocum, J. Michael

2012-01-01

Voice of Experience advances the tradition of service of the "Journal of Research Administration" by fostering consideration of and reflection upon contemporary issues and concerns in research administration. VOE is a celebrated feature column in each edition of the Journal. In this article, the author presents a review of recent literature…

International Trends in Health Science Librarianship Part 19: The Balkan States (Bulgaria and Croatia).

PubMed

Kirilova, Savina; Skoric, Lea

2016-09-01

This is the 19th in a series of articles exploring international trends in health science librarianship in the 21st century. The focus of the present issue is the Balkan Region (Bulgaria and Croatia). The next regular feature column will investigate two other Balkan states - Serbia and Slovenia. JM. © 2016 Health Libraries Group.

Case Study: Crazy about Cryptids--An Ecological Hunt for Nessie and Other Legendary Creatures

ERIC Educational Resources Information Center

Rowe, Matthew P.

2015-01-01

This column provides original articles on innovations in case study teaching, assessment of the method, as well as case studies with teaching notes. This hybrid case has three overarching and interrelated goals. First, it can be used to familiarize students with a range of ecological concepts and terms. Second, it is intended to engage students in…

Actin Immobilization on Chitin for Purifying Myosin II: A Laboratory Exercise That Integrates Concepts of Molecular Cell Biology and Protein Chemistry

ERIC Educational Resources Information Center

de Souza, Marcelle Gomes; Grossi, Andre Luiz; Pereira, Elisangela Lima Bastos; da Cruz, Carolina Oliveira; Mendes, Fernanda Machado; Cameron, Luiz Claudio; Paiva, Carmen Lucia Antao

2008-01-01

This article presents our experience on teaching biochemical sciences through an innovative approach that integrates concepts of molecular cell biology and protein chemistry. This original laboratory exercise is based on the preparation of an affinity chromatography column containing F-actin molecules immobilized on chitin particles for purifying…

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

Bertholon, François; Harant, Olivier; Bourlon, Bertrand

This article introduces a joined Bayesian estimation of gas samples issued from a gas chromatography column (GC) coupled with a NEMS sensor based on Giddings Eyring microscopic molecular stochastic model. The posterior distribution is sampled using a Monte Carlo Markov Chain and Gibbs sampling. Parameters are estimated using the posterior mean. This estimation scheme is finally applied on simulated and real datasets using this molecular stochastic forward model.

Special Research Column: Empathetic Genres, Empathetic Spaces, and Mentoring: Examining Contemporary Research on First-Generation College Students in First-Year Writing

ERIC Educational Resources Information Center

Borchert, Jessica Jorgenson

2017-01-01

This article focuses on contemporary research on first-generation college students bringing to light pedagogical interventions that can be used in the classroom to help engage and retain these students. The pedagogical interventions focus on reflective and personal writing in the classroom, creating safe spaces, and opening up opportunities for…

International Trends in Health Science Librarianship Part 18: The Middle East (Iran, Qatar and Turkey).

PubMed

Zeraatkar, Kimia; Ayatollahi, Haleh; Havlin, Tracy; Neves, Karen; Şendir, Mesra

2016-06-01

This is the 18th in a series of articles exploring international trends in health science librarianship in the 21st century. The focus of the present issue is the Middle East (Iran, Qatar and Turkey). The next feature column will investigate trends in the Balkan States JM. © 2016 Health Libraries Group.

Focus on Infants & Toddlers (Ages 0-3): A Quarterly Newsletter for the Education Community, 2000-2001.

ERIC Educational Resources Information Center

Barry, Virginia M., Ed.; Cantor, Patricia, Ed.

2001-01-01

These four quarterly newsletter issues address various topics of interest to child caregivers. Each issue includes articles on a specific theme, along with regular news or a column by an AECI Executive Board vice president. The Fall 2000 issue focuses on the special features and unique concerns of employer-sponsored child care, with one article…

The Number Pad Game

ERIC Educational Resources Information Center

Fink, Alex; Guy, Richard

2007-01-01

In this article, we explore the game based on the following problem from the 1st Mathematical Olympiad of Central America and the Caribbean, held in Costa Rica in 1999: Player A turns on the calculator, presses a digit key and then presses the + key. A second later, player B presses a digit key in the same row or column of the last digit key…

Glyoxal Vertical Column Retrievals from the GOME-2/METOP-A European Spaceborne Sensor and Comparisons with the IMAGESv2 CT Model

NASA Astrophysics Data System (ADS)

Lerot, C.; Stavrakou, T.; de Smedt, I.; Muller, J. J.; van Roozendael, M.

2010-12-01

Glyoxal is mostly formed in our atmosphere as an intermediate product in the oxidation of non-methane volatile organic compounds (NMVOC). To a lesser extent, it is also directly emitted from biomass burning events and from fossil- and bio-fuel combustion processes. Several studies have estimated its atmospheric lifetime to 2-3 hours, which makes of glyoxal a good indicator for short-lived NMVOC emissions. Glyoxal is also known to be a precursor for secondary organic aerosols and could help to reduce the gap between observations and models for organic aerosol abundances. The three absorption bands of glyoxal in the visible region allow applying the DOAS (Differential Optical Absorption Spectroscopy) technique to retrieve its vertical column densities from the nadir backscattered light measurements performed by the GOME-2 satellite sensor. This instrument has been launched in October 2006 on board of the METOP-A platform and is characterized by a spatial resolution of 80 km x 40 km and by a large scan-width (1920 km) leading to a global coverage reached in 1.5 day. The GOME-2 glyoxal retrieval algorithm developed at BIRA-IASB accounts for the liquid water absorption and provides geophysically sound column measurements not only over lands but also over oceanic regions where spectral interferences between glyoxal and liquid water have been shown to be significant. The a-priori glyoxal vertical distribution required for the slant to vertical column conversion is provided by the global chemical transport model IMAGESv2. The highest glyoxal vertical column densities are mainly observed in continental tropical regions, while the mid-latitude columns strongly depend on the season with maximum values during warm months. An anthropogenic signature is also observed in highly populated regions of Asia. Comparisons with glyoxal columns simulated with IMAGESv2 in different regions of the world generally point to a missing glyoxal source in current models. As already reported from previous analysis with the SCIAMACHY instrument, significant glyoxal columns are also observed over tropical oceans, which remains unexplained so far.

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

Youker, Amanda J.; Krebs, John F.; Quigley, Kevin J.

With funding from the National Nuclear Security Administrations Material Management and Minimization Office, Argonne National Laboratory (Argonne) is providing technical assistance to help accelerate the U.S. production of Mo-99 using a non-highly enriched uranium (non-HEU) source. A potential Mo-99 production pathway is by accelerator-initiated fissioning in a subcritical uranyl sulfate solution containing low enriched uranium (LEU). As part of the Argonne development effort, we are undertaking the AMORE (Argonne Molybdenum Research Experiment) project, which is essentially a pilot facility for all phases of Mo-99 production, recovery, and purification. Production of Mo-99 and other fission products in the subcritical target solutionmore » is initiated by putting an electron beam on a depleted uranium (DU) target; the fast neutrons produced in the DU target are thermalized and lead to fissioning of U-235. At the end of irradiation, Mo is recovered from the target solution and separated from uranium and most of the fission products by using a titania column. The Mo is stripped from the column with an alkaline solution. After acidification of the Mo product solution from the recovery column, the Mo is concentrated (and further purified) in a second titania column. The strip solution from the concentration column is then purified with the LEU Modified Cintichem process. A full description of the process can be found elsewhere [1–3]. The initial commissioning steps for the AMORE project include performing a Mo-99 spike test with pH 1 sulfuric acid in the target vessel without a beam on the target to demonstrate the initial Mo separation-and-recovery process, followed by the concentration column process. All glovebox operations were tested with cold solutions prior to performing the Mo-99 spike tests. Two Mo-99 spike tests with pH 1 sulfuric acid have been performed to date. Figure 1 shows the flow diagram for the remotely operated Mo-recovery system for the AMORE project. There are two separate pumps and flow paths for the acid and base operations. The system contains three sample ladders with eight sample loops per ladder for target mixing; column loading, including acid and water washes; and column stripping, including the final water wash.« less

Seismic Tremors and Three-Dimensional Magma Wagging

NASA Astrophysics Data System (ADS)

Liao, Y.; Bercovici, D.

2015-12-01

Seismic tremor is a feature shared by many silicic volcanoes and is a precursor of volcanic eruption. Many of the characteristics of tremors, including their frequency band from 0.5 Hz to 7 Hz, are common for volcanoes with very different geophysical and geochemical properties. The ubiquitous characteristics of tremor imply that it results from some generation mechanism that is common to all volcanoes, instead of being unique to each volcano. Here we present new analysis on the magma-wagging mechanism that has been proposed to generate tremor. The model is based on the suggestion given by previous work (Jellinek & Bercovici 2011; Bercovici et.al. 2013) that the magma column is surrounded by a compressible, bubble-rich foam annulus while rising inside the volcanic conduit, and that the lateral oscillation of the magma inside the annulus causes observable tremor. Unlike the previous two-dimensional wagging model where the displacement of the magma column is restricted to one vertical plane, the three-dimensional model we employ allows the magma column to bend in different directions and has angular motion as well. Our preliminary results show that, without damping from viscous deformation of the magma column, the system retains angular momentum and develops elliptical motion (i.e., the horizontal displacement traces an ellipse). In this ''inviscid'' limit, the magma column can also develop instabilities with higher frequencies than what is found in the original two-dimensional model. Lateral motion can also be out of phase for various depths in the magma column leading to a coiled wagging motion. For the viscous-magma model, we predict a similar damping rate for the uncoiled magma column as in the two-dimensional model, and faster damping for the coiled magma column. The higher damping thus requires the existence of a forcing mechanism to sustain the oscillation, for example the gas-driven Bernoulli effect proposed by Bercovici et al (2013). Finally, using our new 3-D model, the spectrum of displacement and unsynchronized cross-correlation between displacements measured from different locations can be calculated, and this can be compared to more detailed seismic measurements on well monitored volcanoes.

Subnanogram proteomics: Impact of LC column selection, MS instrumentation and data analysis strategy on proteome coverage for trace samples

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

Zhu, Ying; Zhao, Rui; Piehowski, Paul D.

One of the greatest challenges for mass spectrometry (MS)-based proteomics is the limited ability to analyze small samples. Here we investigate the relative contributions of liquid chromatography (LC), MS instrumentation and data analysis methods with the aim of improving proteome coverage for sample sizes ranging from 0.5 ng to 50 ng. We show that the LC separations utilizing 30-µm-i.d. columns increase signal intensity by >3-fold relative to those using 75-µm-i.d. columns, leading to 32% increase in peptide identifications. The Orbitrap Fusion Lumos mass spectrometer significantly boosted both sensitivity and sequencing speed relative to earlier generation Orbitraps (e.g., LTQ-Orbitrap), leading tomore » a ~3× increase in peptide identifications and 1.7× increase in identified protein groups for 2 ng tryptic digests of bacterial lysate. The Match Between Runs algorithm of open-source MaxQuant software further increased proteome coverage by ~ 95% for 0.5 ng samples and by ~42% for 2 ng samples. The present platform is capable of identifying >3000 protein groups from tryptic digestion of cell lysates equivalent to 50 HeLa cells and 100 THP-1 cells (~10 ng total proteins), respectively, and >950 proteins from subnanogram bacterial and archaeal cell lysates. The present ultrasensitive LC-MS platform is expected to enable deep proteome coverage for subnanogram samples, including single mammalian cells.« less

Crocheted ETFE-reactor for on-line post-column photoderivatization of diclofenac in high-performance liquid chromatography.

PubMed

Kuhlmann, O; Krauss, G J

1997-12-01

A sensitive and selective bioanalytical method for diclofenac using reversed-phase HPLC and fluorescence detection is described. Diclofenac was detected as its fluorescent derivative after on-line post-column photoderivatization. Irradiation with UV light of diclofenac in aqueous solutions leads to the sequential loss of both chlorine substituents and ring closure. The major product, carbazole-1-acetic acid, was detected by a fluorescence detector using an excitation wavelength of 286 nm and an emission wavelength of 360 nm. The self-made reactor was a crocheted ethylene and tetrafluoroethylene (ETFE, named TEFZEL) capillary, 20 m in length, wound directly around a 253.7 nm UV lamp. The capillary was crocheted in order to overcome peak widening. Chromatographic separation was achieved by using a Regis SPS 100 RP-8 column (5 microm; 150 mm x 4.6 mm i.d.) and a LiChrospher 100 RP-18 (5 microm) guard column from E. Merck. The detection limit was 1 ng ml(-1) at an injection volume of 20 microl. Daily relative standard deviations (RSD) were 5.5%, (73 ng diclofenac/ml, n = 9), and 5.1% (405 ng diclofenac/ml, n = 6), respectively. Chromatograms of human aqueous humor and human serum containing diclofenac, and figures showing the time dependent increase/decrease of the photoderivatization product, are shown.

Interpreting space-based trends in carbon monoxide with multiple models

DOE PAGES

Strode, Sarah A.; Worden, Helen M.; Damon, Megan; ...

2016-06-10

Here, we use a series of chemical transport model and chemistry climate model simulations to investigate the observed negative trends in MOPITT CO over several regions of the world, and to examine the consistency of time-dependent emission inventories with observations. We also found that simulations driven by the MACCity inventory, used for the Chemistry Climate Modeling Initiative (CCMI), reproduce the negative trends in the CO column observed by MOPITT for 2000–2010 over the eastern United States and Europe. However, the simulations have positive trends over eastern China, in contrast to the negative trends observed by MOPITT. The model bias inmore » CO, after applying MOPITT averaging kernels, contributes to the model–observation discrepancy in the trend over eastern China. This demonstrates that biases in a model's average concentrations can influence the interpretation of the temporal trend compared to satellite observations. The total ozone column plays a role in determining the simulated tropospheric CO trends. A large positive anomaly in the simulated total ozone column in 2010 leads to a negative anomaly in OH and hence a positive anomaly in CO, contributing to the positive trend in simulated CO. Our results demonstrate that accurately simulating variability in the ozone column is important for simulating and interpreting trends in CO.« less

Interpreting space-based trends in carbon monoxide with multiple models

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

Strode, Sarah A.; Worden, Helen M.; Damon, Megan

Here, we use a series of chemical transport model and chemistry climate model simulations to investigate the observed negative trends in MOPITT CO over several regions of the world, and to examine the consistency of time-dependent emission inventories with observations. We also found that simulations driven by the MACCity inventory, used for the Chemistry Climate Modeling Initiative (CCMI), reproduce the negative trends in the CO column observed by MOPITT for 2000–2010 over the eastern United States and Europe. However, the simulations have positive trends over eastern China, in contrast to the negative trends observed by MOPITT. The model bias inmore » CO, after applying MOPITT averaging kernels, contributes to the model–observation discrepancy in the trend over eastern China. This demonstrates that biases in a model's average concentrations can influence the interpretation of the temporal trend compared to satellite observations. The total ozone column plays a role in determining the simulated tropospheric CO trends. A large positive anomaly in the simulated total ozone column in 2010 leads to a negative anomaly in OH and hence a positive anomaly in CO, contributing to the positive trend in simulated CO. Our results demonstrate that accurately simulating variability in the ozone column is important for simulating and interpreting trends in CO.« less

Interpreting Space-Based Trends in Carbon Monoxide with Multiple Models

NASA Technical Reports Server (NTRS)

Strode, Sarah A.; Worden, Helen M.; Damon, Megan; Douglass, Anne R.; Duncan, Bryan N.; Emmons, Louisa K.; Lamarque, Jean-Francois; Manyin, Michael; Oman, Luke D.; Rodriguez, Jose M.;

Production of the biopesticide azadirachtin by hairy root cultivation of Azadirachta indica in liquid-phase bioreactors.

PubMed

Srivastava, Smita; Srivastava, Ashok K

2013-11-01

Batch cultivation of Azadirachta indica hairy roots was carried out in different liquid-phase bioreactor configurations (stirred-tank, bubble column, bubble column with polypropylene basket, and polyurethane foam disc as root supports) to investigate possible scale-up of the A. indica hairy root culture for in vitro production of the biopesticide azadirachtin. The hairy roots failed to grow in the conventional bioreactor designs (stirred tank and bubble column). However, modified bubble column reactor (with polyurethane foam as root support) configuration facilitated high-density culture of A. indica hairy roots with a biomass production of 9.2 g l(-1)dry weight and azadirachtin yield of 3.2 mg g(-1) leading to a volumetric productivity of azadirachtin as 1.14 mg l(-1) day(-1). The antifeedant activity in the hairy roots was also evaluated by no choice feeding tests with known concentrations of the hairy root powder and its solvent extract separately on the desert locust Schistocerca gregaria. The hairy root powder and its solvent extract demonstrated a high level of antifeedant activity (with an antifeedant index of 97 % at a concentration of 2 % w/v and 83 % at a concentration of 0.05 % (w/v), respectively, in ethanol).

What drives observed space-borne variations of formaldehyde columns over the Indian subcontinent?

NASA Astrophysics Data System (ADS)

Surl, Luke; Palmer, Paul

2017-04-01

Oxidation of volatile organic compounds (VOCs) leads to the formation of secondary air pollutants (e.g. formaldehyde, HCHO) and secondary organic aerosol linked with deleterious impacts on human health. Our focus in this study is the Indian subcontinent where there is a range of chemical environments that span forest ecosystems (dominated by biogenic VOCs) to megacities that are sometimes influenced by upwind sources (e.g. agricultural burning), both with and without some marine influence. To understand this range of environments we use space-borne column observations of HCHO from the Ozone Monitoring Instrument (OMI), in coordination with the GEOS-Chem atmospheric chemistry transport model, to provide insight into the emissions and photochemical processes in the atmosphere. As part of this work we have developed a HCHO vertical column product using slant column retrievals from the NASA OMHCHO v003 product combined with air-mass factors determined by a high-resolution (c25 km), nested run of the GEOS-Chem model. We report our analysis for a calendar year, studying in particular seasonal cycles associated with biogenic emissions, agricultural burning, and meteorology (most notably monsoon dynamics). We also consider the extent to which these satellite data can provide information on city-sized spatial scales, and investigate such an approach for some of India's megacities.

Biosorption of copper by marine algae Gelidium and algal composite material in a packed bed column.

PubMed

Vilar, Vítor J P; Botelho, Cidália M S; Loureiro, José M; Boaventura, Rui A R

2008-09-01

Marine algae Gelidium and algal composite material were investigated for the continuous removal of Cu(II) from aqueous solution in a packed bed column. The biosorption behaviour was studied during one sorption-desorption cycle of Cu(II) in the flow through column fed with 50 and 25 mg l(-1) of Cu(II) in aqueous solution, at pH 5.3, leading to a maximum uptake capacity of approximately 13 and 3 mg g(-1), respectively, for algae Gelidium and composite material. The breakthrough time decreases as the inlet copper concentration increases, for the same flow rate. The pH of the effluent decreases over the breakthrough time of copper ions, which indicates that ion exchange is one of the mechanisms involved in the biosorption process. Temperature has little influence on the metal uptake capacity and the increase of the ionic strength reduces the sorption capacity, decreasing the breakthrough time. Desorption using 0.1M HNO(3) solution was 100% effective. After two consecutive sorption-desorption cycles no changes in the uptake capacity of the composite material were observed. A mass transfer model including film and intraparticle resistances, and the equilibrium relationship, for adsorption and desorption, was successfully applied for the simulation of the biosorption column performance.

Impact of Madden-Julian Oscillation (MJO) on global distribution of total water vapor and column ozone

NASA Astrophysics Data System (ADS)

Fathurochman, Irvan; Lubis, Sandro W.; Setiawan, Sonni

2017-01-01

The Madden-Julian Oscillation (MJO) is the leading mode of intra-seasonal variability in the tropical troposphere, characterized by an eastward moving ‘pulse’ of cloud and rainfall near the equator. In this study, total precipitable water (TPW) and total column ozone (TCO) datasets from ECMWF ERA-Interim reanalysis were used to analyse the impact of the MJO on the distribution of water vapor and column ozone in the tropics from 1979 to 2013. The results show that seasonal variations of TPW modulated by the MJO are maximized in the tropics of about 10°S-10°N during boreal winter, while the variation in TCO is maximized in the mid-latitudes of about 30°S - 40°N in the same season. The composite analysis shows that MJO modulates TPW and TCO anomalies eastward across the globe. The underlying mechanism of the MJO’s impact on TPW is mainly associated with variation of tropical convection modulated by the MJO, while the underlying mechanism of the MJO’s impact on TCO is mainly associated with an intra-seasonal variability of tropopause height modulated by the MJO activity. This knowledge helps to improve the prediction skill of the intra-seasonal variation of water vapor and column ozone in the tropics during boreal winter.

Development of pseudo-linear gradient elution for high-throughput resin selectivity screening in RoboColumn® Format.

PubMed

Kiesewetter, André; Menstell, Peter; Peeck, Lars H; Stein, Andreas

2016-11-01

Rapid development of chromatographic processes relies on effective high-throughput screening (HTS) methods. This article describes the development of pseudo-linear gradient elution for resin selectivity screening using RoboColumns ® . It gives guidelines for the implementation of this HTS method on a Tecan Freedom EVO ® robotic platform, addressing fundamental aspects of scale down and liquid handling. The creation of a flexible script for buffer preparation and column operation plus efficient data processing provided the basis for this work. Based on the concept of discretization, linear gradient elution was transformed into multistep gradients. The impact of column size, flow rate, multistep gradient design, and fractionation scheme on separation efficiency was systematically investigated, using a ternary model protein mixture. We identified key parameters and defined optimal settings for effective column performance. For proof of concept, we examined the selectivity of several cation exchange resins using various buffer conditions. The final protocol enabled a clear differentiation of resin selectivity on miniature chromatography column (MCC) scale. Distinct differences in separation behavior of individual resins and the influence of buffer conditions could be demonstrated. Results obtained with the robotic platform were representative and consistent with data generated on a conventional chromatography system. A study on antibody monomer/high molecular weight separation comparing MCC and lab scale under higher loading conditions provided evidence of the applicability of the miniaturized approach to practically relevant feedstocks with challenging separation tasks as well as of the predictive quality for larger scale. A comparison of varying degrees of robotic method complexity with corresponding effort (analysis time and labware consumption) and output quality highlights tradeoffs to select a method appropriate for a given separation challenge or analytical constraints. © 2016 American Institute of Chemical Engineers Biotechnol. Prog., 32:1503-1519, 2016. © 2016 American Institute of Chemical Engineers.

[Scientific articles in the Icelandic Medical Journal 2004-2008: an overview].

PubMed

Gudbjartsson, Tómas; Sigurdsson, Engilbert

2009-10-01

In the past 5 years the Icelandic Medical Journal has undergone many changes during a period of flourishing research in Iceland. The process of reviewing and editing scientific articles has been revised since the Journal joined the Medline database in 2005 and the proportion of rejected articles has risen. New columns have been launched covering medical history, professionalism, ethics and hobbies of the medical profession. We categorized all scientific articles from the period 2004-2008, that is research articles, review articles, case reports and clinical guidelines, according to types of articles and to which medical speciality or subspeciality the publication should belong. The number of scientific articles rose during the period but the number of research articles remained around 20 most years during the period. The relative proportion of research articles therefore fell whereas the number and proportion of review articles and case reports increased. Clinical guidelines ceased to appear in the Journal. The contribution of individual specialities to the Journal varied widely. Researchers amongst doctors and related professions need be encouraged to submit scientific articles to the Journal. The publication of scientific articles in English in the web-based form of the Journal may prove to be stimulating in this regard for Icelandic doctors abroad as well as for some researchers in Iceland.

Speaking of women's 'nameless misery': the everyday construction of depression in Australian women's magazines.

PubMed

Gattuso, Suzy; Fullagar, Simone; Young, Ilena

2005-10-01

In this article we examine the tensions between current Australian depression policy directions and lay beliefs about depression as constructed and circulated through popular media at a time when mental health education discourses are also promoting 'depression literacy' [Parslow & Jorm, 2002. Medical Journal of Australia, 177(7), 117-121]. Drawing upon research into articles on depression published in two women's magazines before and after the promulgation of the National Action Plan for Depression [Commonwealth Department of Health and Aged Care, 2000. National action plan for depression. Canberra: Commonwealth Department of Health and Aged Care-Mental Health and Special Programs Branch] we identify the cultural context of certain lay beliefs about depression as articulated through personal and celebrity stories, advice columns and resource links. The depression literacy literature privileges biomedical and psychological expertise in explaining depression and promoting help-seeking behaviour. In contrast, the magazine discourses foreground an individualising discourse of depression as a problem of self-management while also referring to biomedical expertise. They emphasise women's abilities to manage difficult life events and to build informal supportive relationships, which reinforces dominant notions of feminine identity as concerned with balancing competing gender demands. We critique the national policy on depression literacy as taking insufficient account of women's belief structures, which leads, for example, to a limited analysis of stigma. We also critique policy for not engaging sufficiently with the gendered nature of depression and its relation to social inequities, something the magazines replicate.

On-line preconcentration system for lead(II) determination in waste water by atomic absorption spectrometry using active carbon loaded with Pyrogallol Red.

PubMed

Ensafi, Ali A; Khayamian, Taghi; Karbasi, Mohammad H

2003-06-01

An on-line system for enrichment and determination of lead(II) is presented. It is based on the adsorption of lead(II) ions on a minicolumn packed with active carbon loaded with Pyrogallol Red. After preconcentration step, the metal ions are eluted automatically by 5.0 ml of 0.50 M nitric acid solution and the lead ion contents were determined by atomic absorption spectrometry. The influence of chemicals, pH and flow variables were studied as well as effect of potential interfering ions. Under the optimum conditions, the lead ions in aqueous samples were concentrated about 100 fold by the column. The detection limit was 0.001 microg ml(-1). The recovery percent of spliced lead(II) was in the range of 98%-103%.

This Month in Astronomical History: Providing Context for the Advancement of Astronomy

NASA Astrophysics Data System (ADS)

Wilson, Teresa

2018-01-01

This Month in Astronomical History is a short (~500 word) illustrated column hosted on the AAS website (https://had.aas.org/resources/astro-history). Its mission is to highlight people and events that have shaped the development of astronomy to convey a historical context to current researchers, to provide a resource for education and public outreach programs seeking to incorporate a historical perspective, and to share the excitement of astronomy with the public. Knowing how the astronomical journey has proceeded thus far allows current professionals to map where to go next and how to get there. The column charts the first part of this journey by celebrating anniversaries of births, discoveries, and deaths, and the technological advances that made discoveries possible. A new “Further Reading” section encourages readers to pursue subjects in greater depth and strengthens the articles as classroom resources.In the months preceding the 21 August 2017 solar eclipse, the column featured astronomical bodies that come between Earth and the Sun: 2004 Venus transit, the 1878 solar eclipse, and the search for the hypothetical planet Vulcan. Venusian transits were an early but technically challenging way to measure the astronomical unit, now easily done with radar-ranging. Like this year’s event, eclipse chasing and citizen science were part of the 1878 experience. Newton’s Laws seemed to require a planet inside Mercury’s orbit, but General Relativity explained the behavior of Mercury without it. Studying each of these transiting bodies has expanded our knowledge and understanding of the universe differently. Transiting extrasolar planets remain to be explored in a future column. In September, an article on the discovery of Neptune followed the discussion of the non-existent Vulcan quite naturally and expanded on the brief mention of this event in relation to the discovery of Pluto. Suggestions for additional topics are always welcome.The Dudley Observatory supported This Month in Astronomical History through its 2017 Herbert C. Pollock Award. The author thanks the HAD Executive Committee for their careful review of each edition.

[Recent advances and applications of capillary electrochromatography and pressurized capillary electrochromatography].

PubMed

Wu, Yi; Zhang, Xiaohui; Wei, Juan; Xue, Yunyun; Bahatibieke, Marjan; Wang, Yan; Yan, Chao

2009-09-01

Capillary electrochromatography (CEC), in which electroosmotic flow (EOF) created from the electrical double layer is made to act as a pump to drive the mobile phase in a capillary column packed with micro-particulates or coated with stationary phase. Both neutral and charged species can be resolved by CEC. It has been demonstrated that the efficiency of a separation obtained by electroosmotic propulsion is superior to that obtained by pressure-driven flow (as is the case in HPLC). CEC combines the best features of CE and versatile selectivity and large sample capacity of HPLC, promising high efficiency, high resolution, high selectivity and high peak capacity. However, in practice, when CEC is used without pressure, often used on a commercial CE instrument, there are problems and difficulties associated with bubbles formation and column dry-out. These difficulties can be overcome by a pressurized CEC (pCEC) system, in which a supplementary pressure is applied to the column in addition to the EOF. In such a system, a pressure can be applied to the capillary column to suppress bubbles formation. Quantitative sample introduction in pCEC can be easily achieved through a rotary-type injector. Most importantly, it is amenable for a solvent gradient mode, similar to that in HPLC, by programming the composition of mobile phase. The article brings a comprehensive survey of recent development of CEC and pCEC, including the development of instrumentation, capillary columns and stationary phase as well as CEC and pCEC applications in life science, biotechnology, pharmaceutical analysis, food safety and environmental security. Prospects for CEC and pCEC development and application are also discussed.

Advantages of core-shell particle columns in Sequential Injection Chromatography for determination of phenolic acids.

PubMed

Chocholouš, Petr; Vacková, Jana; Srámková, Ivana; Satínský, Dalibor; Solich, Petr

2013-01-15

Currently, for Sequential Injection Chromatography (SIC), only reversed phase C18 columns have been used for chromatographic separations. This article presents the first use of three different stationary phases: three core-shell particle-packed reversed phase columns in flow systems. The aim of this work was to extend the chromatographic capabilities of the SIC system. Despite the particle-packed columns reaching system pressures of ≤ 610 PSI, their conditions matched those of a commercially produced and optimised SIC system (SIChrom™ (FIAlab(®), USA)) with a 8-port high-pressure selection valve and medium-pressure Sapphire™ syringe pump with a 4 mL reservoir and maximum system pressure of ≤ 1000 PSI. The selectivity of each of the tested columns, Ascentis(®) Express RP-Amide, Ascentis(®) Express Phenyl-Hexyl and Ascentis(®) Express C18 (30 mm × 4.6mm, core-shell particle size 2.7 μm), was compared by their ability to separate seven phenolic acids that are secondary metabolite substances widely distributed in plants. The separations of all of the components were performed by isocratic elution using binary mobile phases composed of acetonitrile and 0.065% phosphoric acid at pH 2.4 (a specific ratio was used for each column) at a flow-rate of 0.60 mL/min. The volume of the mobile phase was 3.8 mL for each separation. The injection volume of the sample was 10 μL for each separation. The UV detection wavelengths were set to 250, 280 and 325 nm. The RP-Amide column provided the highest chromatographic resolution and allowed for complete baseline separation of protocatechuic, syringic, vanillic, ferulic, sinapinic, p-coumaric and o-coumaric acids. The Phenyl-Hexyl and C18 columns were unable to completely separate the tested mixture, syringic and vanillic acid and ferulic and sinapinic acids could not be separated from one another. The analytical parameters were a LOD of 0.3 mg L(-1), a LOQ of 1.0 mg L(-1), a calibration range of 1.0-50.0 (100.0) mg L(-1) (r>0.997) and a system precision of 10 mg L(-1) with a RSD ≤ 1.65%. The high performance of the chromatography process with the RP-Amide column under optimised conditions was highlighted and well documented (HETP values ≤ 10 μm, peak symmetry ≤ 1.33, resolution ≥ 1.87 and time for one analysis <8.0 min). The results of these experiments confirmed the benefits of extending chromatographic selectivity using core-shell particle column technology in a SIC manifold. Copyright © 2012 Elsevier B.V. All rights reserved.

Automated method for simultaneous lead and strontium isotopic analysis applied to rainwater samples and airborne particulate filters (PM10).

PubMed

Beltrán, Blanca; Avivar, Jessica; Mola, Montserrat; Ferrer, Laura; Cerdà, Víctor; Leal, Luz O

2013-09-03

A new automated, sensitive, and fast system for the simultaneous online isolation and preconcentration of lead and strontium by sorption on a microcolumn packed with Sr-resin using an inductively coupled plasma mass spectrometry (ICP-MS) detector was developed, hyphenating lab-on-valve (LOV) and multisyringe flow injection analysis (MSFIA). Pb and Sr are directly retained on the sorbent column and eluted with a solution of 0.05 mol L(-1) ammonium oxalate. The detection limits achieved were 0.04 ng for lead and 0.03 ng for strontium. Mass calibration curves were used since the proposed system allows the use of different sample volumes for preconcentration. Mass linear working ranges were between 0.13 and 50 ng and 0.1 and 50 ng for lead and strontium, respectively. The repeatability of the method, expressed as RSD, was 2.1% and 2.7% for Pb and Sr, respectively. Environmental samples such as rainwater and airborne particulate (PM10) filters as well as a certified reference material SLRS-4 (river water) were satisfactorily analyzed obtaining recoveries between 90 and 110% for both elements. The main features of the LOV-MSFIA-ICP-MS system proposed are the capability to renew solid phase extraction at will in a fully automated way, the remarkable stability of the column which can be reused up to 160 times, and the potential to perform isotopic analysis.

Spellings Seeks to Cast Her Glow over NCLB

ERIC Educational Resources Information Center

Hoff, David J.

2008-01-01

In her three years as U.S. secretary of education, Margaret Spellings has been a celebrity contestant on "Jeopardy!," a guest on "The Daily Show With Jon Stewart," and an occasional subject of Washington's best-read gossip column. Above all, though, she's been the nation's leading spokeswoman for the No Child Left Behind Act…

The Games Children Play

ERIC Educational Resources Information Center

Padak, Nancy; Rasinski, Timothy

2008-01-01

The games that children play are not just for fun-they often lead to important skill development. Likewise, word games are fun opportunities for parents and children to spend time together and for children to learn a lot about sounds and words. In this Family Involvement column, the authors describe 12 easy-to-implement word games that parents and…

Comments on higher rank Wilson loops in N = 2∗

NASA Astrophysics Data System (ADS)

Liu, James T.; Zayas, Leopoldo A. Pando; Zhou, Shan

2018-01-01

For N = 2∗ theory with U( N ) gauge group we evaluate expectation values of Wilson loops in representations described by a rectangular Young tableau with n rows and k columns. The evaluation reduces to a two-matrix model and we explain, using a combination of numerical and analytical techniques, the general properties of the eigen-value distributions in various regimes of parameters ( N, λ , n, k) where λ is the 't Hooft coupling. In the large N limit we present analytic results for the leading and sub-leading contributions. In the particular cases of only one row or one column we reproduce previously known results for the totally symmetry and totally antisymmetric representations. We also extensively discusss the N = 4 limit of the N = 2∗ theory. While establishing these connections we clarify aspects of various orders of limits and how to relax them; we also find it useful to explicitly address details of the genus expansion. As a result, for the totally symmetric Wilson loop we find new contributions that improve the comparison with the dual holographic computation at one loop order in the appropriate regime.

[Airway management in a man with ankylosing spondylitis].

PubMed

Gil, S; Jamart, V; Borrás, R; Miranda, A

2007-02-01

We report a case of difficult airway management in a 41-year-old man with ankylosing spondylitis who was scheduled for total left hip replacement surgery. After several failed attempts to achieve regional anesthesia, we converted to general anesthesia with orotracheal intubation using a fiberoptic bronchoscope. Ankylosing spondylitis leads to fibrosis, ossification, and ankylosis along the spinal column and sacroiliac articulations. Cervical column and atlantooccipital articulation mobility are reduced and in severe cases the cervical vertebrae become fixed in a flexed position. This portion of the spine is also the most susceptible to fracture, particularly in hyperextension, an event that could lead to damage to the cervical spinal cord during maneuvers to manage the airway. Patients with this condition may also have temporomandibular joint involvement, further complicating airway management. We report the case of a patient with ankylosing spondylitis with fixation along the entire spine. The airway was managed by intubation with a fiberoptic bronchoscope. Spontaneous ventilation was maintained during the maneuver, and sedation was achieved with perfusion of remifentanil as the only anesthetic agent following failure of intradural anesthesia.

Focus on Pre-K and K (Ages 4-6): A Quarterly Newsletter for the Education Community, 1997-1998.

ERIC Educational Resources Information Center

Kravitz, Deborah Jordan, Ed.

1998-01-01

These four quarterly newsletter issues address various topics of interest to teachers of young children. Each issue focuses on a theme and includes an article on that theme, along with regular columns. The Fall 1997 issue focuses on kindergartners as inquirers and on using a negotiated curriculum in the early childhood setting. The vice…

Allocating Sample Sizes to Reduce Budget for Fixed-Effect 2×2 Heterogeneous Analysis of Variance

ERIC Educational Resources Information Center

Luh, Wei-Ming; Guo, Jiin-Huarng

2016-01-01

This article discusses the sample size requirements for the interaction, row, and column effects, respectively, by forming a linear contrast for a 2×2 factorial design for fixed-effects heterogeneous analysis of variance. The proposed method uses the Welch t test and its corresponding degrees of freedom to calculate the final sample size in a…

Focus on Infants & Toddlers (Ages 0-3): A Quarterly Newsletter for the Education Community, 1999-2000.

ERIC Educational Resources Information Center

Barry, Virginia M., Ed.; Cantor, Patricia, Ed.

2000-01-01

These four quarterly newsletter issues address various topics of interest to child caregivers. Each issue focuses on a theme and includes articles on that theme, along with regular news or vice president's columns. The Fall 1999 issue addresses family play and seeks to encourage families to regard play as a way of relaxing and finding contentment…

Re-Reconsidering Research on Learning from Media: Comments on Richard E. Clark's "Point of View" Column on Serious Games

ERIC Educational Resources Information Center

Parker, J. R.; Becker, Katrin; Sawyer, Ben

2008-01-01

Everything old is new again. In a recent "Point of View" editorial commentary in "Educational Technology," Richard E. Clark revisits the now-famous media-effects debate with a focus on serious games. Clark argues that serious games have little to offer that improves upon traditional methods. This article responds to those claims. While Clark's…

Show & Tell: A Video Column / Don't Just Gather Data--Use It

ERIC Educational Resources Information Center

Fisher, Doug; Frey, Nancy

2015-01-01

Schools are awash in data, and teachers are being asked to gather data in a myriad of high-tech and low-tech ways. But gathering is not analyzing, and without analysis there is little reason to gather the data in the first place. Teachers need data-collection systems that lend themselves to rapid analysis and action. This article presents several…

Book Review: Encyclopedia of Astronomy and Astrophysics. Volumes 1-4

NASA Technical Reports Server (NTRS)

Maran, Stephen Paul

2001-01-01

This massive reference work (hereafter EAA) summarizes a great deal of what we knew in the astronomical sciences at the most recent Millennium. An associated website may keep much of it up-to-date for years to come. The contents are extensive indeed: the index alone consists of 76 pages, each with three columns of fine-type listings, and there are 'nearly 700 main articles'. The main articles are what make EAA worthwhile. They are generally by experts, who took much care in their preparation. The degree to which the articles are illustrated and referenced, however, seems to depend on the inclination of the individual author. On the other hand, articles on Saturn's rings and on its satellites are heavily illustrated, but with just two or three citations in each. The coverage of solar physics is especially thorough in EAA. There are numerous articles on major topics, notably in the physics and phenomena of the corona and the chromosphere, and some on more specialized areas, such as 'Polar Plumes' and 'Coronal Cavities.'

Mercury and methylmercury concentrations in high altitude lakes and fish (Arctic charr) from the French Alps related to watershed characteristics.

PubMed

Marusczak, Nicolas; Larose, Catherine; Dommergue, Aurélien; Paquet, Serge; Beaulne, Jean-Sébastien; Maury-Brachet, Régine; Lucotte, Marc; Nedjai, Rachid; Ferrari, Christophe P

2011-04-15

Total mercury (THg) and methylmercury (MeHg) concentrations were measured in the muscle of Arctic charr (Salvelinus alpinus) and in the water column of 4 lakes that are located in the French Alps. Watershed characteristics were determined (6 coverage classes) for each lake in order to evaluate the influence of watershed composition on mercury and methylmercury concentrations in fish muscle and in the water column. THg and MeHg concentrations in surface water were relatively low and similar among lakes and watershed characteristics play a major role in determining water column Hg and MeHg levels. THg muscle concentrations for fish with either a standardized length of 220mm, a standardized age of 5 years or for individualuals did not exceed the 0.5mg kg(-1) fish consumption advisory limit established for Hg by the World Health Organization (WHO, 1990). These relatively low THg concentrations can be explained by watershed characteristics, which lead to short Hg residence time in the water column, and also by the short trophic chain that is characteristic of mountain lakes. Growth rate did not seem to influence THg concentrations in fish muscles of these lakes and we observed no relationship between fish Hg concentrations and altitude. This study shows that in the French Alps, high altitude lakes have relatively low THg and MeHg concentrations in both the water column and in Arctic charr populations. Therefore, Hg does not appear to present a danger for local populations and the fishermen of these lakes. Copyright © 2011 Elsevier B.V. All rights reserved.

The influence of synoptic weather regimes on UK air quality: regional model studies of tropospheric column NO2

NASA Astrophysics Data System (ADS)

Pope, R. J.; Savage, N. H.; Chipperfield, M. P.; Ordóñez, C.; Neal, L. S.

2015-07-01

Synoptic meteorology can have a significant influence on UK air quality. Cyclonic (anticyclonic) conditions lead to the dispersion (accumulation) of air pollutants away from (over) source regions. Meteorology also modifies atmospheric chemistry processes such as photolysis and wet deposition. Previous studies have shown a relationship between observed satellite tropospheric column NO2 and synoptic meteorology in different seasons. Here, we test whether the UK Met Office Air Quality in the Unified Model (AQUM) can reproduce these observations and then use the model to determine the controlling factors. We show that AQUM successfully captures the observed relationships, when sampled under the Lamb Weather Types, an objective classification of midday UK circulation patterns. By using a range of idealised NOx-like tracers with different e-folding lifetimes, we show that under different synoptic regimes the NO2 lifetime in AQUM is approximately 6 h in summer and 12 h in winter. The longer lifetime can explain why synoptic spatial column NO2 variations are more significant in winter compared to summer, due to less NO2 photochemical loss. We also show that cyclonic conditions have more seasonality in column NO2 than anticyclonic conditions as they result in more extreme spatial departures from the wintertime seasonal average. Within a season (summer or winter) under different synoptic regimes, a large proportion of the spatial pattern in the UK column NO2 field can be explained by the idealised model tracers, showing that transport is an important factor in governing the variability of UK air quality on seasonal synoptic timescales.

Heavy metal leaching from mine tailings as affected by plants

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

Zhu, D.; Schwab, A.P.; Banks, M.K.

A column experiment was conducted to determine the impact of soil cover and plants on heavy metal leaching from mine tailings and heavy metal contaminated soil. Columns made of PVC were constructed with 30 cm subsoil covered by 30 cm of mine tailings followed by 0, 30, or 60 cm subsoil covered by 30 cm of mine tailings followed by 0, 30, or 60 cm of clean topsoil. Two grasses, tall fescue (Festuca arundinacea Schreb.) and big bluestem (Andropogon gerardii), were grown in the columns. The columns were leached at a slow rate for 1 yr with a 0.001 Mmore » CaCl{sub 2} solution under unsaturated conditions. The presence of both tall fescue and big bluestem increased Zn and Cd concentrations in the leachate. Lead concentrations in leachates were not affected by the presence of plants. Although plants generally reduced the total amount of water leached, total mass of Zn and Cd leached generally was not impacted by plants. Total mass of Pb leached was positively correlated with total leachate collected from each column. Covering the mine tailings with 60 cm of topsoil increased the mass of Zn and Cd leached relative to no topsoil. When the subsoil was absent, Zn and Cd leaching increased by as much as 20-fold, verifying the ability of soil to act as a sink for metals. Mine tailing remediation by establishing vegetation can reduce Pb movement but may enhance short-term Cd and Zn leaching. However, the changes were relatively small and do not outweigh the benefits of using vegetation in mine tailings reclamation.« less

Self-organized Sr leads to solid state twinning in nano-scaled eutectic Si phase

PubMed Central

Albu, M.; Pal, A.; Gspan, C.; Picu, R. C.; Hofer, F.; Kothleitner, G.

2016-01-01

A new mechanism for twin nucleation in the eutectic Al-Si alloy with trace Sr impurities is proposed. Observations made by sub-angstrom resolution scanning transmission electron microscopy and X-ray probing proved the presence of <110> Sr columns located preferentially at twin boundaries. Density functional theory simulations indicate that Sr atoms bind in the Si lattice only along the <110> direction, with preferential positions at first and second nearest neighbors for interstitial and substitutional Sr, respectively. Density functional theory total energy calculations confirm that twin nucleation at Sr columns is energetically favorable. Hence, twins may nucleate in Si precipitates after solidification, which provides a different perspective to the currently accepted mechanism which suggests twin formation during precipitate growth. PMID:27527789

Self-organized Sr leads to solid state twinning in nano-scaled eutectic Si phase

NASA Astrophysics Data System (ADS)

Albu, M.; Pal, A.; Gspan, C.; Picu, R. C.; Hofer, F.; Kothleitner, G.

2016-08-01

A new mechanism for twin nucleation in the eutectic Al-Si alloy with trace Sr impurities is proposed. Observations made by sub-angstrom resolution scanning transmission electron microscopy and X-ray probing proved the presence of <110> Sr columns located preferentially at twin boundaries. Density functional theory simulations indicate that Sr atoms bind in the Si lattice only along the <110> direction, with preferential positions at first and second nearest neighbors for interstitial and substitutional Sr, respectively. Density functional theory total energy calculations confirm that twin nucleation at Sr columns is energetically favorable. Hence, twins may nucleate in Si precipitates after solidification, which provides a different perspective to the currently accepted mechanism which suggests twin formation during precipitate growth.

Data on the identity and myristoylation state of recombinant, purified hippocalcin.

PubMed

Krishnan, Anuradha; Viviano, Jeffrey; Morozov, Yaroslav; Venkataraman, Venkat

2016-09-01

In this data article we report on the purity and post translation modification of bacterially expressed and purified recombinant hippocalcin (HPCA): a member of the neuronal calcium sensor protein family, whose functions are regulated by calcium. MALDI-TOF in source decay (ISD) analysis was used to identify both the myristoylated or non-myristoylated forms of the protein. MALDI-TOF ISD data on the identity of the protein, amino acid sequence and myristoylation efficiency are provided. This data relates to the article "Single-Column Purification of the Tag-free, Recombinant Form of the Neuronal Calcium Sensor Protein, Hippocalcin Expressed in Eschericia coli" [1].

Introduction: the influence and legacy of Barbara Grier.

PubMed

DeMuth, Danielle M

2014-01-01

This special issue of the Journal of Lesbian Studies focuses on the life and legacy of the lesbian publisher, editor, and author Barbara Grier. Through Grier's "Lesbiana" column in Daughters of Bilitis's magazine The Ladder, three editions of The Lesbian in Literature (1967, 1975, 1985), to her role as publisher of the Naiad Press from 1973-2003, Grier introduced hundreds of new lesbian books to readers and kept several lesbian classics on the literary horizon. The articles in this issue focus on Grier's biography, history, and impact through archival analysis, interviews, and content analysis. This introduction contextualizes and outlines the articles in this special issue.

Conway's Game of Life: Early Personal Recollections

NASA Astrophysics Data System (ADS)

Wainwright, Robert

When the October 1970 issue of Scientific American arrived, I had no idea the extent to which Martin Gardner's article in that issue would affect my life. As long as I can remember, my custom would be to seek out the Mathematical Games column in search for Gardner's latest topic with the usual reader challenges. My first reaction to that particular article introducing a new pastime titled "The fantastic combinations of John Conway's new solitaire game 'life''' was only mildly interesting. A couple of days later, still curious about the outcome of random patterns, I located an old checkerboard and a small jarful of pennies to investigate this new game.

Simultaneous Analysis of Monovalent Anions and Cations with a Sub-Microliter Dead-Volume Flow-Through Potentiometric Detector for Ion Chromatography

PubMed Central

Dumanli, Rukiye; Attar, Azade; Erci, Vildan; Isildak, Ibrahim

2016-01-01

A microliter dead-volume flow-through cell as a potentiometric detector is described in this article for sensitive, selective and simultaneous detection of common monovalent anions and cations in single column ion chromatography for the first time. The detection cell consisted of less selective anion- and cation-selective composite membrane electrodes together with a solid-state composite matrix reference electrode. The simultaneous separation and sensitive detection of sodium (Na+), potassium (K+), ammonium (NH4+), chloride (Cl−) and nitrate (NO3−) in a single run was achieved by using 98% 1.5 mM MgSO4 and 2% acetonitrile eluent with a mixed-bed ion-exchange separation column without suppressor column system. The separation and simultaneous detection of the anions and cations were completed in 6 min at the eluent flow-rate of 0.8 mL/min. Detection limits, at S/N = 3, were ranged from 0.2 to 1.0 µM for the anions and 0.3 to 3.0 µM for the cations, respectively. The developed method was successfully applied to the simultaneous determination of monovalent anions and cations in several environmental and biological samples. PMID:26786906

The use of spin desalting columns in DMSO-quenched H/D-exchange NMR experiments

PubMed Central

Chandak, Mahesh S; Nakamura, Takashi; Takenaka, Toshio; Chaudhuri, Tapan K; Yagi-Utsumi, Maho; Chen, Jin; Kato, Koichi; Kuwajima, Kunihiro

2013-01-01

Dimethylsulfoxide (DMSO)-quenched hydrogen/deuterium (H/D)-exchange is a powerful method to characterize the H/D-exchange behaviors of proteins and protein assemblies, and it is potentially useful for investigating non-protected fast-exchanging amide protons in the unfolded state. However, the method has not been used for studies on fully unfolded proteins in a concentrated denaturant or protein solutions at high salt concentrations. In all of the current DMSO-quenched H/D-exchange studies of proteins so far reported, lyophilization was used to remove D2O from the protein solution, and the lyophilized protein was dissolved in the DMSO solution to quench the H/D exchange reactions and to measure the amide proton signals by two-dimensional nuclear magnetic resonance (2D NMR) spectra. The denaturants or salts remaining after lyophilization thus prevent the measurement of good NMR spectra. In this article, we report that the use of spin desalting columns is a very effective alternative to lyophilization for the medium exchange from the D2O buffer to the DMSO solution. We show that the medium exchange by a spin desalting column takes only about 10 min in contrast to an overnight length of time required for lyophilization, and that the use of spin desalting columns has made it possible to monitor the H/D-exchange behavior of a fully unfolded protein in a concentrated denaturant. We report the results of unfolded ubiquitin in 6.0M guanidinium chloride. PMID:23339068

Vertical distribution of aerosols in the vicinity of Mexico City during MILAGRO-2006 Campaign

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

Lewandowski, P.A.; Kleinman, L.; Eichinger, W. E.

On 7 March 2006, a mobile, ground-based, vertical pointing, elastic lidar system made a North-South transect through the Mexico City basin. Column averaged, aerosol size distribution (ASD) measurements were made on the ground concurrently with the lidar measurements. The ASD ground measurements allowed calculation of the column averaged mass extinction efficiency (MEE) for the lidar system (1064 nm). The value of column averaged MEE was combined with spatially resolved lidar extinction coefficients to produce total aerosol mass concentration estimates with the resolution of the lidar (1.5 m vertical spatial and 1 s temporal). Airborne ASD measurements from DOE G-1 aircraftmore » made later in the day on 7 March 2006, allowed the evaluation of the assumptions of constant ASD with height and time used for estimating the column averaged MEE. The results showed that the aerosol loading within the basin is about twice what is observed outside of the basin. The total aerosol base concentrations observed in the basin are of the order of 200 {mu}g/m{sup 3} and the base levels outside are of the order of 100 {mu}g/m{sup 3}. The local heavy traffic events can introduce aerosol levels near the ground as high as 900 {mu}g/m{sup 3}. The article presents the methodology for estimating aerosol mass concentration from mobile, ground-based lidar measurements in combination with aerosol size distribution measurements. An uncertainty analysis of the methodology is also presented.« less

Determination of carbon isotope ratios for honey samples by means of a liquid chromatography/isotope ratio mass spectrometry system coupled with a post-column pump.

PubMed

Kawashima, Hiroto; Suto, Momoka; Suto, Nana

2018-05-20

Liquid chromatography/isotope ratio mass spectrometry (LC/IRMS) has been used to authenticate and trace products such as honey, wine, and lemon juice, and compounds such as caffeine and pesticides. However, LC/IRMS has several disadvantages, including the high cost of the CO 2 membrane and blocking by solidified sodium persulfate. Here, we developed an improved system for determining carbon isotope ratios by LC/IRMS. The main improvement was the use of a post-column pump. Using the improved system, we determined δ 13 C values for glucose with high accuracy and precision (0.1‰ and 0.1‰, respectively; n = 3). The glucose, fructose, disaccharide, trisaccharide, and organic acid constituents of the honey samples were analyzed by LC/IRMS. The δ 13 C values for glucose, fructose, disaccharides, trisaccharides, and organic acids ranged from -27.0 to -24.2‰, -26.8 to -24.0‰, -28.8 to -24.0‰, -27.8 to -22.8‰, and -30.6 to -27.4‰, respectively. The analysis time was 1/3-1/2 the times required for analysis by previously reported methods. The column flow rate could be arbitrarily adjusted with the post-column pump. We applied the improved method to 26 commercial honey samples. Our results can be expected to be useful for other researchers who use LC/IRMS. This article is protected by copyright. All rights reserved.

Ethics in oncology: consulting for the investment industry.

PubMed

Berlin, Jordan; Bruinooge, Suanna S; Tannock, Ian F

2007-02-01

As Ethics Committee Chair, I am pleased to introduce the first in an ongoing series of ethics vignettes. These columns, which are based on true-to-life situations that arise in oncology research and practice, are intended to identify and explore important ethical issues and provide commentary that is specific to oncology. Please look for them periodically in both the Journal of Clinical Oncology and the Journal of Oncology Practice. The idea for publishing vignettes evolved through the joint efforts of the Ethics Committee and the Board of Directors. Rather than adopt a single set of ethical principles that applies vaguely to any situation and well to none, the Committee and the Board preferred to tackle ethical dilemmas individually, specifically, and directly. Because the Ethics Committee thought the ethical and legal implications of physician interactions with the investment industry were so important and timely, it chose to address this topic in both a position article, which was previously published in the January 20, 2007, issue of the Journal of Clinical Oncology (J Clin Oncol 25:338-340, 2007) and in its first vignette column. The Ethics Committee hopes this column will be the first of several that ASCO members will find helpful as they grapple with the many ethical issues that arise in daily practice in the field of oncology. Because these columns are intended to address the concerns of ASCO members, the Committee welcomes suggestions for future topics at vignettes@asco.org. Martin D. Abeloff, MD, Chair, Ethics Committee.

Weak partitioning chromatography for anion exchange purification of monoclonal antibodies.

PubMed

Kelley, Brian D; Tobler, Scott A; Brown, Paul; Coffman, Jonathan L; Godavarti, Ranga; Iskra, Timothy; Switzer, Mary; Vunnum, Suresh

2008-10-15

Weak partitioning chromatography (WPC) is an isocratic chromatographic protein separation method performed under mobile phase conditions where a significant amount of the product protein binds to the resin, well in excess of typical flowthrough operations. The more stringent load and wash conditions lead to improved removal of more tightly binding impurities, although at the cost of a reduction in step yield. The step yield can be restored by extending the column load and incorporating a short wash at the end of the load stage. The use of WPC with anion exchange resins enables a two-column cGMP purification platform to be used for many different mAbs. The operating window for WPC can be easily established using high throughput batch-binding screens. Under conditions that favor very strong product binding, competitive effects from product binding can give rise to a reduction in column loading capacity. Robust performance of WPC anion exchange chromatography has been demonstrated in multiple cGMP mAb purification processes. Excellent clearance of host cell proteins, leached Protein A, DNA, high molecular weight species, and model virus has been achieved. (c) 2008 Wiley Periodicals, Inc.

Analysis of free zone electrophoresis of fixed erythrocytes performed in microgravity

NASA Technical Reports Server (NTRS)

Snyder, Robert S.; Rhodes, Percy H.; Herren, Blair J.; Miller, Teresa Y.; Seaman, Geoffrey V. F.

1985-01-01

A free fluid zone electrophoresis experiment was performed in the microgravity environment of Space Shuttle flight STS-3 (March 1983). The experiment was designed to confirm observations made on the Apollo-Soyuz mission of 1975 and to test the effect of high red blood cell (RBC) concentration on free fluid electrophoresis. Photographic documentation of cell zone progression in one-hour separations of mixtures of formaldehyde-fixed human and rabbit erythrocytes, which were subjected to a field of approximately 13 V/cm in low ionic strength buffer, was analyzed. One of two columns contained 2 x 10 to the 8th RBC/ml; (low concentration), and the other contained 1 x 10 to the 9th RBC/ml (high concentration). The observed and calculated leading edge displacements of the RBC in the two columns were in agreement, indicating the absence of unexpected effects of the reduced gravity environment. Post-flight analyses of the contents of the columns was not possible, and additional microgravity experiments are needed to evaluate the role of particle-particle interactions in concentrated suspensions undergoing electrophoresis.

Tracing geogenic and anthropogenic sources in urban dusts: Insights from lead isotopes

NASA Astrophysics Data System (ADS)

Del Rio-Salas, R.; Ruiz, J.; De la O-Villanueva, M.; Valencia-Moreno, M.; Moreno-Rodríguez, V.; Gómez-Alvarez, A.; Grijalva, T.; Mendivil, H.; Paz-Moreno, F.; Meza-Figueroa, D.

2012-12-01

Tracing the source of metals in the environment is critical to understanding their pollution level and fate. Geologic materials are an important source of airborne particulate matter, but the contribution of contaminated soil to concentrations of Pb in airborne dust is not yet widely documented. To examine the potential significance of this mechanism, surface soil samples were collected, as well as wind-transported dust trapped at 1 and 2 m height at seven different locations including residential, industrial, high-traffic and rural sites. Samples of dust deposited on roofs from 24 schools were also obtained and analyzed for Pb isotope ratios. Spatial distribution of Pb of airborne and sedimented dust suggests a process dominated by re-suspension/sedimentation, which was controlled by erosion, traffic and topography of the urban area. Anthropogenic lead input in the city grades outward the urban zone toward geogenic values. Our results shows that Pb-isotopic signatures of leaded gasoline are imprinted in dust sedimented on roofs. Considering that leaded-gasoline has not been in use in Mexico since two decades ago, this signature shows not only a Pb-legacy in soil, but also a re-suspension process affecting air column below 3 m in height. The combination of the 207Pb/206Pb data of the surrounding rocks and urban dust, reveal three well-defined zones with remarkable anthropogenic influence, which correspond to the oldest urban sectors. This work highlights the importance of spatial characterization of metals in particles suspended below a height of 3 m of the airborne column, a fact that should be considered to identify exposure paths to humans and the potential risks. Lead isotope signatures allowed the identification of geogenic and anthropogenic emission sources for dust, a matter that deserves consideration in the efforts to control airborne metal emissions.

Biosurfactant technology for remediation of cadmium and lead contaminated soils.

PubMed

Juwarkar, Asha A; Nair, Anupa; Dubey, Kirti V; Singh, S K; Devotta, Sukumar

2007-08-01

This research focuses on column experiments conducted to evaluate the potential of environmentally compatible rhamnolipid biosurfactant produced by Pseudomonas aeruginosa strain BS2 to remove heavy metals (Cd and Pb) from artificially contaminated soil. Results have shown that di-rhamnolipid removes not only the leachable or available fraction of Cd and Pb but also the bound metals as compared to tap water which removed the mobile fraction only. Washing of contaminated soil with tap water revealed that approximately 2.7% of Cd and 9.8% of Pb in contaminated soil was in freely available or weakly bound forms whereas washing with rhamnolipid removed 92% of Cd and 88% of Pb after 36 h of leaching. This indicated that di-rhamnolipid selectively favours mobilization of metals in the order of Cd>Pb. Biosurfactant specificity observed towards specific metal will help in preferential elution of specific contaminant using di-rhamnolipid. It was further observed that pH of the leachates collected from heavy metal contaminated soil column treated with di-rhamnolipid solution was low (6.60-6.78) as compared to that of leachates from heavy metal contaminated soil column treated with tap water (pH 6.90-7.25), which showed high dissolution of metal species from the contaminated soil and effective leaching of metals with treatment with biosurfactant. The microbial population of the contaminated soil was increased after removal of metals by biosurfactant indicating the decrease of toxicity of metals to soil microflora. This study shows that biosurfactant technology can be an effective and nondestructive method for bioremediation of cadmium and lead contaminated soil.

Subnanogram proteomics: impact of LC column selection, MS instrumentation and data analysis strategy on proteome coverage for trace samples

DOE PAGES

Zhu, Ying; Zhao, Rui; Piehowski, Paul D.; ...

2017-09-01

One of the greatest challenges for mass spectrometry (MS)-based proteomics is the limited ability to analyze small samples. Here in this study, we investigate the relative contributions of liquid chromatography (LC), MS instrumentation and data analysis methods with the aim of improving proteome coverage for sample sizes ranging from 0.5 ng to 50 ng. We show that the LC separations utilizing 30-μm-i.d. columns increase signal intensity by >3-fold relative to those using 75-μm-i.d. columns, leading to 32% increase in peptide identifications. The Orbitrap Fusion Lumos MS significantly boosted both sensitivity and sequencing speed relative to earlier generation Orbitraps (e.g., LTQ-Orbitrap),more » leading to a ~3-fold increase in peptide identifications and 1.7-fold increase in identified protein groups for 2 ng tryptic digests of the bacterium S. oneidensis. The Match Between Runs algorithm of open-source MaxQuant software further increased proteome coverage by ~95% for 0.5 ng samples and by ~42% for 2 ng samples. Using the best combination of the above variables, we were able to identify >3,000 proteins from 10 ng tryptic digests from both HeLa and THP-1 mammalian cell lines. We also identified >950 proteins from subnanogram archaeal/bacterial cocultures. Finally, the present ultrasensitive LC-MS platform achieves a level of proteome coverage not previously realized for ultra-small sample loadings, and is expected to facilitate the analysis of subnanogram samples, including single mammalian cells.« less

EFFECTS OF PORE STRUCTURE CHANGE AND MULTI-SCALE HETEROGENEITY ON CONTAMINANT TRANSPORT AND REACTION RATE UPSCALING

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

Lindquist, W. Brent; Jones, Keith W.; Um, Wooyong

2013-02-15

This project addressed the scaling of geochemical reactions to core and field scales, and the interrelationship between reaction rates and flow in porous media. We targeted reactive transport problems relevant to the Hanford site - specifically the reaction of highly caustic, radioactive waste solutions with subsurface sediments, and the immobilization of 90Sr and 129I through mineral incorporation and passive flow blockage, respectively. We addressed the correlation of results for pore-scale fluid-soil interaction with field-scale fluid flow, with the specific goals of (i) predicting attenuation of radionuclide concentration; (ii) estimating changes in flow rates through changes of soil permeabilities; and (iii)more » estimating effective reaction rates. In supplemental work, we also simulated reactive transport systems relevant to geologic carbon sequestration. As a whole, this research generated a better understanding of reactive transport in porous media, and resulted in more accurate methods for reaction rate upscaling and improved prediction of permeability evolution. These scientific advancements will ultimately lead to better tools for management and remediation of DOE’s legacy waste problems. We established three key issues of reactive flow upscaling, and organized this project in three corresponding thrust areas. 1) Reactive flow experiments. The combination of mineral dissolution and precipitation alters pore network structure and the subsequent flow velocities, thereby creating a complex interaction between reaction and transport. To examine this phenomenon, we conducted controlled laboratory experimentation using reactive flow-through columns. Results and Key Findings: Four reactive column experiments (S1, S3, S4, S5) have been completed in which simulated tank waste leachage (STWL) was reacted with pure quartz sand, with and without Aluminum. The STWL is a caustic solution that dissolves quartz. Because Al is a necessary element in the formation of secondary mineral precipitates (cancrinite), conducting experiments under conditions with and without Al allowed us to experimentally separate the conditions that lead to quartz dissolution from the conditions that lead to quartz dissolution plus cancrinite precipitation. Consistent with our expectations, in the experiments without Al, there was a substantial reduction in volume of the solid matrix. With Al there was a net increase in the volume of the solid matrix. The rate and extent of reaction was found to increase with temperature. These results demonstrate a successful effort to identify conditions that lead to increases and conditions that lead to decreases in solid matrix volume due to reactions of caustic tank wastes with quartz sands. In addition, we have begun to work with slightly larger, intermediate-scale columns packed with Hanford natural sediments and quartz. Similar dissolution and precipitation were observed in these colums. The measurements are being interpreted with reactive transport modeling using STOMP; preliminary observations are reported here. 2) Multi-Scale Imaging and Analysis. Mineral dissolution and precipitation rates within a porous medium will be different in different pores due to natural heterogeneity and the heterogeneity that is created from the reactions themselves. We used a combination of X-ray computed microtomography, backscattered electron and energy dispersive X-ray spectroscopy combined with computational image analysis to quantify pore structure, mineral distribution, structure changes and fluid-air and fluid-grain interfaces. Results and Key Findings: Three of the columns from the reactive flow experiments at PNNL (S1, S3, S4) were imaged using 3D X-ray computed microtomography (XCMT) at BNL and analyzed using 3DMA-rock at SUNY Stony Brook. The imaging results support the mass balance findings reported by Dr. Um’s group, regarding the substantial dissolution of quartz in column S1. An important observation is that of grain movement accompanying dissolution in the unconsolidated media. The resultant movement changes the anticipated findings for pore and throat size distributions. For column S3, with cancrinite precipitation accompanying quartz dissolution, the precitiation halts much of the grain movement and more systematic distributions are obtained. Column S4, which was sealed with caustic solution acted as a control sample to study reactive effects during periods when columns S1 and S3 were sealed between flow experiments. No significant changes are observed in S4 with time. At Princeton, the imaging and analysis work focused on the effects of mineral precipitation and advancing our understanding of the impacts of these reactions on reactive transport in subsurface sediments. These findings are described in detail below, and have been published in L.E. Crandell, C.A. Peters, W. Um, K.W. Jones, W.B. Lindquist, 2012. “Changes in the pore network structure of Hanford sediment after reaction with caustic tank wastes.” Journal of Contaminant Hydrology 131 (2012) 89–99. 3) Multi-Scale Modeling and Up-Scaling. Using an array of modeling approaches, we examined pore-scale variations in physical and mineralogical properties, flow velocities, and (for unsaturated conditions) wetting fluid/grain surface areas, and permeability evolution. Results and Key Findings: To predict the column permeability and estimate the impact of mineral precipitation, pore network models were informed using the pore and throat-size distributions from the imaging analyses. As a comparison, supplemental analyses were performed on Viking sandstone specimens from the Alberta sedimentary basin. In another part of this study we sought to understand how carbonate rocks in contact with CO2-rich brines change due to the precipitation or dissolution of fast-reacting minerals such as calcite and dolomite. Using a newly developed reactive-transport pore-network model we were able to identify the conditions that lead to significant permeability changes. These findings are presented below and are compiled in a publication that is under review: J.P. Nogues, J.P. Fitts, M.A. Celia, C.A. Peters. “Permeability evolution due to dissolution and precipitation of carbonates using reactive transport modeling in pore networks”, Submitted: Water Resources Research, 2013.« less

A revisit of the role of gas entrapment on the stability conditions of explosive volcanic columns

NASA Astrophysics Data System (ADS)

Michaud-Dubuy, Audrey; Carazzo, Guillaume; Kaminski, Edouard; Girault, Frédéric

2018-05-01

Explosive volcanic eruptions produce high-velocity turbulent jets that can form either a stable buoyant Plinian column or a collapsing fountain producing pyroclastic density currents (PDC). Determining the source conditions leading to these extreme regimes is a major goal in physical volcanology. Classically, the regime boundary is defined as the critical eruptive mass discharge rate (MDR) before collapse for a given amount of free gas in the eruptive mixture (free gas + pyroclasts) at the vent. Previous studies have shown that an agreement between theory and field data can be achieved in two different frameworks: (i) by accounting for the effect of gas entrapment in large pumice fragments, which lowers the effective gas content, depending on the total grain-size distribution (TGSD) of pyroclastic fragments, or (ii) by accounting for the reduction of turbulent entrainment at the base of the volcanic column due to its negative buoyancy. Here, we aim at combining these two using a 1D model of volcanic column that includes sedimentation to follow the evolution of the TGSD. In powerful (≥ 107 kg s-1) Plinian eruptions, the loss of particles by sedimentation acts as to decrease the load of particles during the plume rise, which favors the formation of a stable column. In this case, we obtain that coarse TGSD promote the formation of stable plumes, a result at odds with the predictions of models considering gas entrapment in large pyroclastic fragments. To interpret this conclusion, we reconsider the effect of gas entrapment and show that in general, it has a dominant role on column collapse compared to particle sedimentation, and hinders the formation of buoyant columns. This drastic effect is reduced when incorporating open porosity, e.g. by considering that some bubbles inside a fragment are connected to the exterior. The characteristics of the PDC produced by column collapse are then predicted as a function of the TGSD and MDR at the source. We further test the model using two well-documented historical events, the ≈186 CE Taupo and 79 CE Vesuvius eruptions. Our model predictions are consistent with the Taupo eruption record, but not with the Vesuvius one. In this latter case, we suggest that the characteristics of the TGSD imply to take into account the thermal disequilibrium between gas and pyroclasts.

Silica particles encapsulated poly(styrene-divinylbenzene) monolithic stationary phases for micro-high performance liquid chromatography.

PubMed

Bakry, R; Stöggl, W M; Hochleitner, E O; Stecher, G; Huck, C W; Bonn, G K

2006-11-03

In the paper we demonstrate a new approach for the preparation and application of continuous silica bed columns that involve encapsulation (entrapment) of functionalized silica microparticles, which can be used as packing material in micro high performance liquid chromatography (micro-HPLC) and capillary electrochromatography (CEC). Like traditional packed columns, these capillaries possess characterized silica particles that offer high phase ratio and narrow pore size distribution leading to high retention and separation efficiency, respectively. More importantly, immobilization of the microparticles stabilizes the separation bed and eliminates the need for retaining frits. The developed capillary columns were fabricated in exactly the same way as a packed capillary column (slurry packing) but with an additional entrapment step. This immobilization of the packed bed was achieved by in situ polymerization of styrene and divinylbenzene in presence of decanol as a porogen and azobisisobutyronitrile as thermal initiator. Silica particles with different particle sizes and pore sizes ranging from 60 to 4000 A were studied. In addition different modified silica was used, including C-18 reversed phase, anion exchange and chiral stationary phases. Efficient separation of polyphenolic compounds, peptides, proteins and even DNA mutation were achieved using the developed technique depending on the properties of the silica particles used (particles pore size). For example, using 3 microm ProntoSIL C-18 particles with 300 A pore size, separation efficiencies in the range of 120,000-200,000 plates/m were obtained for protein separation, in a 6 cm x 200 microm i.d. capillary column. Using encapsulated silica C-18 with 1000 A pore size, separation of DNA homo and hetero duplexes were achieved under denaturing HPLC conditions for mutation detection. In addition, nucleotides were separated using anion exchange material encapsulated with poly(styrene-divinylbenzene) (PS/DVB), which indicated that the chromatographic properties of the silica packing material were still active after polymerization. The prepared capillary columns were found to be stable and could easily be operated continuously up to a pressure of 350 bar without column damage and capillary can be cut to any desired length.

Assessment of contamination by percolation of septic tank effluent through natural and amended soils.

PubMed

Cheung, K C; Venkitachalam, T H

2004-01-01

Fly ash has been found to be a potential material for the treatment of municipal and industrial wastewater, and may be useful in the treatment of septic tank effluent. Laboratory columns (30 cm) were used to determine the sorption capacity and hydraulic properties of lagoon fly ash, loamy sand, sand, and sand amended by lagoon fly ash (30 and 60%) and red mud gypsum (20%). The removal of chemical oxygen demand (COD) was high in all column effluents (71-93%). Extent of nitrification was high in Spearwood sand, Merribrook loamy sand and 20% red mud gypsum amended Spearwood sand. However, actual removal of nitrogen (N) was high in columns containing lagoon fly ash. Unamended Spearwood sand possessed only minimal capacity for P sorption. Merribrook loamy sand and red mud gypsum amended sand affected complete P removal throughout the study period of 12 weeks. Significant P leakage occurred from lagoon fly ash amended sand columns following 6-10 weeks of operation. Neither lagoon fly ash nor red mud gypsum caused any studied heavy metal contamination including manganese (Mn), lead (Pb), zinc (Zn), cadmium (Cd) and chromium (Cr) of effluent. It can be concluded that Merribrook loamy sand is better natural soil than Spearwood sand as a filter medium. The addition of lagoon fly ash enhanced the removal of P in Spearwood sand but the efficiency was lower than with red mud gypsum amendment.

Microcoil Spring Interconnects for Ceramic Grid Array Integrated Circuits

NASA Technical Reports Server (NTRS)

Strickland, S. M.; Hester, J. D.; Gowan, A. K.; Montgomery, R. K.; Geist, D. L.; Blanche, J. F.; McGuire, G. D.; Nash, T. S.

2011-01-01

As integrated circuit miniaturization trends continue, they drive the need for smaller higher input/output (I/O) packages. Hermetically sealed ceramic area array parts are the package of choice by the space community for high reliability space flight electronic hardware. Unfortunately, the coefficient of thermal expansion mismatch between the ceramic area array package and the epoxy glass printed wiring board limits the life of the interconnecting solder joint. This work presents the results of an investigation by Marshall Space Flight Center into a method to increase the life of this second level interconnection by the use of compliant microcoil springs. The design of the spring and its attachment process are presented along with thermal cycling results of microcoil springs (MCS) compared with state-of-the-art ball and column interconnections. Vibration testing has been conducted on MCS and high lead column parts. Radio frequency simulation and measurements have been made and the MCS has been modeled and a stress analysis performed. Thermal cycling and vibration testing have shown MCS interconnects to be significantly more reliable than solder columns. Also, MCS interconnects are less prone to handling damage than solder columns. Future work that includes shock testing, incorporation into a digital signal processor board, and process evaluation of expansion from a 400 I/O device to a device with over 1,100 I/O is identified.

On Rank and Nullity

ERIC Educational Resources Information Center

Dobbs, David E.

2012-01-01

This note explains how Emil Artin's proof that row rank equals column rank for a matrix with entries in a field leads naturally to the formula for the nullity of a matrix and also to an algorithm for solving any system of linear equations in any number of variables. This material could be used in any course on matrix theory or linear algebra.

Graeco-Latin Squares and a Mistaken Conjecture of Euler

ERIC Educational Resources Information Center

Klyve, Dominic; Stemkoski, Leo

2006-01-01

A Graeco-Latin square of order "n" is an "n[superscript x]n" array whose entries are the "n"[superscript 2] ordered pairs of numbers from 1 to "n", and in each row and each column the first elements of the ordered pairs are all different, as are the second elements. This article traces the history of the results that came out of work on a false…

Designing research: ex post facto designs.

PubMed

Giuffre, M

1997-06-01

The research design is the overall plan or structure of the study. The goal of a good research design is to insure internal validity and answer the question being asked. The only clear rule in selecting a design is that the question dictates the design. Over the next few issues this column will cover types of research designs and their inherent strengths and weaknesses. This article discusses ex post facto research.

Weighted West, Focused on the Indian Ocean and Cooperating across the Indo Pacific: The Indian Navy’s New Maritime Strategy, Capabilities, and Diplomacy

DTIC Science & Technology

2017-02-01

27 Rear Admiral (ret.) Raja Menon, “The Strategic Imperative: Benefits outweigh costs of India, US...intimacies,” The Indian Express, Apr. 16, 2016, http://indianexpress.com/article/opinion/columns/ benefits -outweigh- costs -of-india-us- intimacies-the-strategic...Cleared for Public Release DISTRIBUTION STATEMENT A. Approved for public release: distribution unlimited. Weighted West, Focused

Corrected Article: Simulation and observation of line-slip structures in columnar structures of soft spheres [Phys. Rev. E 96, 012610 (2017)

NASA Astrophysics Data System (ADS)

Winkelmann, J.; Haffner, B.; Weaire, D.; Mughal, A.; Hutzler, S.

2017-07-01

We present the computed phase diagram of columnar structures of soft spheres under pressure, of which the main feature is the appearance and disappearance of line slips, the shearing of adjacent spirals, as pressure is increased. A comparable experimental observation is made on a column of bubbles under forced drainage, clearly exhibiting the expected line slip.

Development and validation of a novel, simple, and accurate spectrophotometric method for the determination of lead in human serum.

PubMed

Shayesteh, Tavakol Heidari; Khajavi, Farzad; Khosroshahi, Abolfazl Ghafuri; Mahjub, Reza

2016-01-01

The determination of blood lead levels is the most useful indicator of the determination of the amount of lead that is absorbed by the human body. Various methods, like atomic absorption spectroscopy (AAS), have already been used for the detection of lead in biological fluid, but most of these methods are based on complicated, expensive, and highly instructed instruments. In this study, a simple and accurate spectroscopic method for the determination of lead has been developed and applied for the investigation of lead concentration in biological samples. In this study, a silica gel column was used to extract lead and eliminate interfering agents in human serum samples. The column was washed with deionized water. The pH was adjusted to the value of 8.2 using phosphate buffer, and then tartrate and cyanide solutions were added as masking agents. The lead content was extracted into the organic phase containing dithizone as a complexion reagent and the dithizone-Pb(II) complex was formed and approved by visible spectrophotometry at 538 nm. The recovery was found to be 84.6 %. In order to validate the method, a calibration curve involving the use of various concentration levels was calculated and proven to be linear in the range of 0.01-1.5 μg/ml, with an R (2) regression coefficient of 0.9968 by statistical analysis of linear model validation. The largest error % values were found to be -5.80 and +11.6 % for intra-day and inter-day measurements, respectively. The largest RSD % values were calculated to be 6.54 and 12.32 % for intra-day and inter-day measurements, respectively. Further, the limit of detection (LOD) was calculated to be 0.002 μg/ml. The developed method was applied to determine the lead content in the human serum of voluntary miners, and it has been proven that there is no statistically significant difference between the data provided from this novel method and the data obtained from previously studied AAS.

Duality based direct resolution of unique profiles using zero concentration region information.

PubMed

Tavakkoli, Elnaz; Rajkó, Róbert; Abdollahi, Hamid

2018-07-01

Self Modeling Curve Resolution (SMCR) is a class of techniques concerned with estimating pure profiles underlying a set of measurements on chemical systems. In general, the estimated profiles are ambiguous (non-unique) except if some special conditions fulfilled. Implementing the adequate information can reduce the so-called rotational ambiguity effectively, and in the most desirable cases lead to the unique solution. Therefore, studies on circumstances resulting in unique solution are of particular importance. The conditions of unique solution can particularly be studied based on duality principle. In bilinear chemical (e.g., spectroscopic) data matrix, there is a natural duality between its row and column vector spaces using minimal constraints (non-negativity of concentrations and absorbances). In this article, the conditions of the unique solution according to duality concept and using zero concentration region information is intended to show. A simulated dataset of three components and an experimental system with synthetic mixtures containing three amino acids tyrosine, phenylalanine and tryptophan are analyzed. It is shown that in the presence of sufficient information, the reliable unique solution is obtained that is valuable in analytical qualification and for quantitative verification analysis. Copyright © 2018 Elsevier B.V. All rights reserved.

Use of natural clinoptilolite for the removal of lead, copper and zinc in fixed bed column.

PubMed

Stylianou, Marinos A; Hadjiconstantinou, Michalis P; Inglezakis, Vasilis J; Moustakas, Konstantinos G; Loizidou, Maria D

2007-05-08

This work deals with the removal of lead, copper and zinc from aqueous solutions by using natural zeolite (clinoptilolite). Fixed bed experiments were performed, using three different volumetric flow rates of 5, 7 and 10bed volume/h, under a total normality of 0.01N, at initial pH of 4 and ambient temperature (25 degrees C). The removal efficiency increased when decreasing the flow rate and the following selectivity series was found: Pb(2+)>Zn(2+)> or =Cu(2+). Conductivity measurements showed that lead removal follows mainly ion exchange mechanism, while copper and zinc removal follows ion exchange and sorption mechanism as well.

"Is political behavior a viable coping strategy to perceived organizational politics? Unveiling the underlying resource dynamics": Correction to Sun and Chen (2017).

PubMed

2017-10-01

Reports an error in "Is Political Behavior a Viable Coping Strategy to Perceived Organizational Politics? Unveiling the Underlying Resource Dynamics" by Shuhua Sun and Huaizhong Chen ( Journal of Applied Psychology , Advanced Online Publication, May 22, 2017, np). In the article, Table 1 contained a formatting error. Correlation coefficient values in the last four cells of column 6 were misplaced with correlation coefficient values in the last four cells of column 7. All versions of this article have been corrected. (The following abstract of the original article appeared in record 2017-22542-001.) We conduct a theory-driven empirical investigation on whether political behavior, as a coping strategy to perceived organizational politics, creates resource trade-offs in moderating the relationship between perceived organizational politics and task performance. Drawing on conservation of resources theory, we hypothesize that political behavior mitigates the adverse effect of perceived organizational politics on task performance via psychological empowerment, yet exacerbates its adverse effect on task performance via emotional exhaustion. Three-wave multisource data from a sample of 222 employees and their 75 supervisors were collected for hypothesis testing. Findings supported our hypotheses. Our study enhances understandings of the complex resource dynamics of using political behavior to cope with perceived organizational politics and highlights the need to move stress-coping research from a focus on the stress-buffering effect of coping on outcomes to a focus on the underlying competing resource dynamics. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

[Determination of lead in edible salt with solid-phase extraction and GFAAS].

PubMed

Zhao, Xin; Zhou, Shuang; Ma, Lan; Yang, Dajin

2013-01-01

Establishing a method for determination of lead in salt with solid-phase extraction and GFAAS. Salt sample was diluted to a certain volume directly with ammonium acetate, then the sample solution was filtered through the solid phase extraction column which has been pre-activated. Lead ions were retained, and the sodium chloride matrix was removed. After elution, the collected lead ions was determined by graphite furnace atomic absorption spectrometry in 257.4 nm. This method can be used effectively to wipe off the sodium chloride in matrix. The limit of detection was 0.7 microg/kg and the limit of quantification was 2 microg/kg. Solid phase extraction technique can be used effectively to reduce the interference in matrix and improves the accuracy and reproducibility of detection.

Elliptic jets, part 2. Dynamics of coherent structures: Pairing

NASA Technical Reports Server (NTRS)

Husain, Hyder S.; Hussain, Fazle

1992-01-01

The dynamics of the jet column mode of vortex pairing in the near field of an elliptic jet was investigated. Hot-wire measurements and flow visualization were used to examine the details of the pairing mechanism of nonplanar vortical elliptic structures and its effect on such turbulence measures as coherent velocities, incoherent turbulence intensities, incoherent and coherent Reynolds, stresses, turbulence production, and mass entrainment. It was found that pairing of elliptic vortices in the jet column does not occur uniformly around the entire perimeter, unlike in a circular jet. Merger occurs only in the initial major-axis plane. In the initial minor-axis plane, the trailing vortex rushes through the leading vortex without pairing and then breaks down violently, producing considerably greater entrainment and mixing than in circular or plane jets.

Godiva, a European Project for Ozone and Trace Gas Measurements from GOME

NASA Astrophysics Data System (ADS)

Goede, A. P. H.; Tanzi, C. P.; Aben, I.; Burrows, J. P.; Weber, M.; Perner, D.; Monks, P. S.; Llewellyn-Jones, D.; Corlett, G. K.; Arlander, D. W.; Platt, U.; Wagner, T.; Pfeilsticker, K.; Taalas, P.; Kelder, H.; Piters, A.

GODIVA (GOME Data Interpretation, Validation and Application) is a European Commission project aimed at the improvement of GOME (Global Ozone Monitoring Experiment) data products. Existing data products include global ozone, NO2 columns and (ir)radiances. Advanced data products include O3 profiles, BrO, HCHO and OCIO columns. These data are validated by ground-based and balloon borne instruments. Calibration issues are investigated by in-flight monitoring using several complementary calibration sources, as well as an on-ground replica of the GOME instrument. The results will lead to specification of operational processing of the EUMETSAT ozone Satellite Application Facility as well as implementation of the improved and new GOME data products in the NILU database for use in the European THESEO (Third European Stratospheric Experiment on Ozone) campaign of 1999

The abundance, distribution, and physical nature of highly ionized oxygen O VI, O VII, and O VIII in IllustrisTNG

NASA Astrophysics Data System (ADS)

Nelson, Dylan; Kauffmann, Guinevere; Pillepich, Annalisa; Genel, Shy; Springel, Volker; Pakmor, Rüdiger; Hernquist, Lars; Weinberger, Rainer; Torrey, Paul; Vogelsberger, Mark; Marinacci, Federico

2018-06-01

We explore the abundance, spatial distribution, and physical properties of the O VI, O VII, and O VIII ions of oxygen in circumgalactic and intergalactic media (the CGM, IGM, and WHIM). We use the TNG100 and TNG300 large volume cosmological magnetohydrodynamical simulations. Modelling the ionization states of simulated oxygen, we find good agreement with observations of the low-redshift O VI column density distribution function (CDDF), and present its evolution for all three ions from z = 0 to z = 4. Producing mock quasar absorption line spectral surveys, we show that the IllustrisTNG simulations are fully consistent with constraints on the O VI content of the CGM from COS-haloes and other low-redshift observations, producing columns as high as observed. We measure the total amount of mass and average column densities of each ion using hundreds of thousands of simulated galaxies spanning 10^{11} < {M}_halo/ M⊙<1015 corresponding to 109 < M⋆/ M⊙<1012 in stellar mass. Stacked radial profiles of O VI are computed in 3D number density and 2D projected column density, decomposing into 1-halo and 2-halo terms. Relating halo O VI to properties of the central galaxy, we find a correlation between the (g - r) colour of a galaxy and the total amount of O VI in its CGM. In comparison to the COS-Haloes finding, this leads to a dichotomy of columns around star-forming versus passive galaxies at fixed stellar (or halo) mass. We demonstrate that this correlation is a direct result of black hole feedback associated with quenching and represents a causal consequence of galactic-scale baryonic feedback impacting the physical state of the circumgalactic medium.

Morphological changes of the caudal cervical intervertebral foramina due to flexion-extension and compression-traction movements in the canine cervical vertebral column.

PubMed

Ramos, Renato M; da Costa, Ronaldo C; Oliveira, Andre L A; Kodigudla, Manoj K; Goel, Vijay K

2015-08-06

Previous studies in humans have reported that the dimensions of the intervertebral foramina change significantly with movement of the spine. Cervical spondylomyelopathy (CSM) in dogs is characterized by dynamic and static compressions of the neural components, leading to variable degrees of neurologic deficits and neck pain. Studies suggest that intervertebral foraminal stenosis has implications in the pathogenesis of CSM. The dimensions of the cervical intervertebral foramina may significantly change during neck movements. This could have implication in the pathogenesis of CSM and other diseases associated with radiculopathy such as intervertebral disc disease. The purpose of this study was to quantify the morphological changes in the intervertebral foramina of dogs during flexion, extension, traction, and compression of the canine cervical vertebral column. All vertebral columns were examined with magnetic resonance imaging prior to biomechanic testing. Eight normal vertebral columns were placed in Group 1 and eight vertebral columns with intervertebral disc degeneration or/and protrusion were assigned to Group 2. Molds of the left and right intervertebral foramina from C4-5, C5-6 and C6-7 were taken during all positions and loading modes. Molds were frozen and vertical (height) and horizontal (width) dimensions of the foramina were measured. Comparisons were made between neutral to flexion and extension, flexion to extension, and traction to compression in neutral position. Extension decreased all the foraminal dimensions significantly, whereas flexion increased all the foraminal dimensions significantly. Compression decreased all the foraminal dimensions significantly, and traction increased the foraminal height, but did not significantly change the foraminal width. No differences in measurements were seen between groups. Our results show movement-related changes in the dimensions of the intervertebral foramina, with significant foraminal narrowing in extension and compression.

Column studies to assess the effects of climate variables on redox processes during riverbank filtration.

PubMed

Rudolf von Rohr, Matthias; Hering, Janet G; Kohler, Hans-Peter E; von Gunten, Urs

2014-09-15

Riverbank filtration is an established technique used world-wide to produce clean drinking water in a reliable and cost-efficient way. This practice is, however, facing new challenges posed by climate change, as already observed during past heat waves with the local occurrence of anoxic conditions. In this study we investigated the effect of direct (temperature) and indirect (dissolved organic matter (DOM) concentration and composition, flow rate) climate change variables on redox processes (aerobic respiration, denitrification and Mn(III/IV)/Fe(III) reduction) by means of column experiments. Natural river water, modified river water and river water mixed with treated wastewater effluent were used as feed waters for the columns filled with natural sand from a river-infiltration system in Switzerland. Biodegradable dissolved organic matter was mainly removed immediately at the column inlet and particulate organic matter (POM) associated with the natural sand was the main electron donor for aerobic respiration throughout the column. Low infiltration rates (≤0.01 m/h) enhanced the oxygen consumption leading to anoxic conditions. DOM consumption did not seem to be sensitive to temperature, although oxygen consumption (i.e., associated with POM degradation) showed a strong temperature dependence with an activation energy of ∼70 kJmol(-1). Anoxic conditions developed at 30 °C with partial denitrification and formation of nitrite and ammonium. In absence of oxygen and nitrate, Mn(II) was mobilized at 20 °C, highlighting the importance of nitrate acting as a redox buffer under anoxic conditions preventing the reductive dissolution of Mn(III/IV)(hydr)oxides. Reductive dissolution of Fe(III)(hydr)oxides was not observed under these conditions. Copyright © 2014 Elsevier Ltd. All rights reserved.

Measurement of Atmospheric CO2 Column Concentrations to Cloud Tops With a Pulsed Multi-Wavelength Airborne Lidar

NASA Technical Reports Server (NTRS)

Mao, Jianping; Ramanathan, Anand; Abshire, James B.; Kawa, Stephan R.; Riris, Haris; Allan, Graham R.; Rodriguez, Michael R.; Hasselbrack, William E.; Sun, Xiaoli; Numata, Kenji;

Measurement of atmospheric CO2 column concentrations to cloud tops with a pulsed multi-wavelength airborne lidar

NASA Astrophysics Data System (ADS)

Mao, Jianping; Ramanathan, Anand; Abshire, James B.; Kawa, Stephan R.; Riris, Haris; Allan, Graham R.; Rodriguez, Michael; Hasselbrack, William E.; Sun, Xiaoli; Numata, Kenji; Chen, Jeff; Choi, Yonghoon; Yang, Mei Ying Melissa

2018-01-01

We have measured the column-averaged atmospheric CO2 mixing ratio to a variety of cloud tops by using an airborne pulsed multi-wavelength integrated-path differential absorption (IPDA) lidar. Airborne measurements were made at altitudes up to 13 km during the 2011, 2013 and 2014 NASA Active Sensing of CO2 Emissions over Nights, Days, and Seasons (ASCENDS) science campaigns flown in the United States West and Midwest and were compared to those from an in situ sensor. Analysis of the lidar backscatter profiles shows the average cloud top reflectance was ˜ 5 % for the CO2 measurement at 1572.335 nm except to cirrus clouds, which had lower reflectance. The energies for 1 µs wide laser pulses reflected from cloud tops were sufficient to allow clear identification of CO2 absorption line shape and then to allow retrievals of atmospheric column CO2 from the aircraft to cloud tops more than 90 % of the time. Retrievals from the CO2 measurements to cloud tops had minimal bias but larger standard deviations when compared to those made to the ground, depending on cloud top roughness and reflectance. The measurements show this new capability helps resolve CO2 horizontal and vertical gradients in the atmosphere. When used with nearby full-column measurements to ground, the CO2 measurements to cloud tops can be used to estimate the partial-column CO2 concentration below clouds, which should lead to better estimates of surface carbon sources and sinks. This additional capability of the range-resolved CO2 IPDA lidar technique provides a new benefit for studying the carbon cycle in future airborne and space-based CO2 missions.

Very high pressure liquid chromatography using fully porous particles: quantitative analysis of fast gradient separations without post-run times.

PubMed

Stankovich, Joseph J; Gritti, Fabrice; Stevenson, Paul G; Beaver, Lois Ann; Guiochon, Georges

2014-01-10

Using a column packed with fully porous particles, four methods for controlling the flow rates at which gradient elution runs are conducted in very high pressure liquid chromatography (VHPLC) were tested to determine whether reproducible thermal conditions could be achieved, such that subsequent analyses would proceed at nearly the same initial temperature. In VHPLC high flow rates are achieved, producing fast analyses but requiring high inlet pressures. The combination of high flow rates and high inlet pressures generates local heat, leading to temperature changes in the column. Usually in this case a post-run time is input into the analytical method to allow the return of the column temperature to its initial state. An alternative strategy involves operating the column without a post-run equilibration period and maintaining constant temperature variations for subsequent analysis after conducting one or a few separations to bring the column to a reproducible starting temperature. A liquid chromatography instrument equipped with a pressure controller was used to perform constant pressure and constant flow rate VHPLC separations. Six replicate gradient separations of a nine component mixture consisting of acetophenone, propiophenone, butyrophenone, valerophenone, hexanophenone, heptanophenone, octanophenone, benzophenone, and acetanilide dissolved in water/acetonitrile (65:35, v/v) were performed under various experimental conditions: constant flow rate, two sets of constant pressure, and constant pressure operation with a programmed flow rate. The relative standard deviations of the response factors for all the analytes are lower than 5% across the methods. Programming the flow rate to maintain a fairly constant pressure instead of using instrument controlled constant pressure improves the reproducibility of the retention times by a factor of 5, when plotting the chromatograms in time. Copyright © 2013 Elsevier B.V. All rights reserved.

Relations of benthic macroinvertebrates to concentrations of trace elements in water, streambed sediments, and transplanted bryophytes and stream habitat conditions in nonmining and mining areas of the upper Colorado River basin, Colorado, 1995-98

USGS Publications Warehouse

Mize, Scott V.; Deacon, Jeffrey R.

2002-01-01

Intensive mining activity and highly mineralized rock formations have had significant impacts on surface-water and streambed-sediment quality and aquatic life within the upper reaches of the Uncompahgre River in western Colorado. A synoptic study by the U.S. Geological Survey National Water-Quality Assessment Program was completed in the upper Uncompahgre River Basin in 1998 to better understand the relations of trace elements (with emphasis on aluminum, arsenic, copper, iron, lead, and zinc concentrations) in water, streambed sediment, and aquatic life. Water-chemistry, streambed-sediment, and benthic macroinvertebrate samples were collected during low-flow conditions between October 1995 and July 1998 at five sites on the upper Uncompahgre River, all downstream from historical mining, and at three sites in drainage basins of the Upper Colorado River where mining has not occurred. Aquatic bryophytes were transplanted to all sites for 15 days of exposure to the water column during which time field parameters were measured and chemical water-quality and benthic macroinvertebrate samples were collected. Stream habitat characteristics also were documented at each site. Certain attributes of surface-water chemistry among streams were significantly different. Concentrations of total aluminum, copper, iron, lead, and zinc in the water column and concentrations of dissolved aluminum, copper, and zinc were significantly different between nonmining and mining sites. Some sites associated with mining exceeded Colorado acute aquatic-life standards for aluminum, copper, and zinc and exceeded Colorado chronic aquatic-life standards for aluminum, copper, iron, lead, and zinc. Concentrations of copper, lead, and zinc in streambed sediments were significantly different between nonmining and mining sites. Generally, concentrations of arsenic, copper, lead, and zinc in streambed sediments at mining sites exceeded the Canadian Sediment Quality Guidelines probable effect level (PEL), except at two mining sites where concentrations of copper and zinc were below the PEL. Concentrations of arsenic, copper, iron, and lead in transplanted bryophytes were significantly different between nonmining and mining sites. Bioconcentration factors calculated for 15-day exposure using one-half of the minimum reporting level were significantly different between nonmining and mining sites. In general, concentrations of trace elements in streambed sediment and transplanted bryophytes were more closely correlated than were the concentrations of trace elements in the water column with streambed sediments or concentrations in the water column with transplanted bryophytes. Stream habitat was rated as optimal to suboptimal using the U.S. Environmental Protection Agency Rapid Bioassessment Protocols for all sites in the study area. Generally, stream habitat conditions were similar at nonmining compared to mining sites and were suitable for diverse macroinvertebrate communities. All study sites had optimal instream habitat except two mining sites with suboptimal instream habitat because of disturbances in stream habitat. The benthic macroinvertebrate community composition at nonmining sites and mining sites differed. Mining sites had significantly lower total abundance of macroinvertebrates, fewer numbers of taxa, and lower dominance of Ephemeroptera (mayflies), Plecoptera (stoneflies), and Trichoptera (caddisflies), and a larger percentage of tolerant species than did nonmining sites. The predominance of Baetis sp. (mayflies), Hydropsychidae (caddisflies), and large percentage of Orthocladiinae chironomids (midges) at mining sites indicated that these species may be tolerant to elevated trace-element concentrations. The absence of Heptageniidae (mayflies), Chloroperlidae (stoneflies), and Rhyacophila sp. (caddisflies) at mining sites indicated that these species may be sensitive to elevated trace-element concentrations. Comparison of field parameters and

Correction: Update on VTE.

PubMed

Bartholomew, John R

2018-03-01

In the article, "Update on the management of venous thromboembolism" (Bartholomew JR, Cleve Clin J Med 2017; 84[suppl 3]:39-46), 2 sentences in the text regarding dose reduction for body weight have errors. The corrected sentences follow: On page 42, left column, the last 5 lines should read: "The recommended dose should be reduced to 2.5 mg twice daily in patients that meet 2 of the following criteria: age 80 or older; body weight of 60 kg or less; or with a serum creatinine 1.5 mg/dL or greater." And on page 42, right column, the sentence 10 lines from the top should read: "Edoxaban is given orally at 60 mg once daily but reduced to 30 mg once daily if the CrCL is 30 mL/min to 50 mL/min, if body weight is 60 kg or less, or with use of certain P-glycoprotein inhibitors."

Expanding the term "Design Space" in high performance liquid chromatography (I).

PubMed

Monks, K E; Rieger, H-J; Molnár, I

2011-12-15

The current article presents a novel approach to applying Quality by Design (QbD) principles to the development of high pressure reversed phase liquid chromatography (HPLC) methods. Four common critical parameters in HPLC--gradient time, temperature, pH of the aqueous eluent, and stationary phase--are evaluated within the Quality by Design framework by the means of computer modeling software and a column database, to a satisfactory degree. This work proposes the establishment of two mutually complimentary Design Spaces to fully depict a chromatographic method; one Column Design Space (CDS) and one Eluent Design Space (EDS) to describe the influence of the stationary phase and of the mobile phase on the separation selectivity, respectively. The merge of both Design Spaces into one is founded on the continuous nature of the mobile phase influence on retention and the great variety of the stationary phases available. Copyright © 2011 Elsevier B.V. All rights reserved.

Passive microwave algorithm development and evaluation

NASA Technical Reports Server (NTRS)

Petty, Grant W.

1995-01-01

The scientific objectives of this grant are: (1) thoroughly evaluate, both theoretically and empirically, all available Special Sensor Microwave Imager (SSM/I) retrieval algorithms for column water vapor, column liquid water, and surface wind speed; (2) where both appropriate and feasible, develop, validate, and document satellite passive microwave retrieval algorithms that offer significantly improved performance compared with currently available algorithms; and (3) refine and validate a novel physical inversion scheme for retrieving rain rate over the ocean. This report summarizes work accomplished or in progress during the first year of a three year grant. The emphasis during the first year has been on the validation and refinement of the rain rate algorithm published by Petty and on the analysis of independent data sets that can be used to help evaluate the performance of rain rate algorithms over remote areas of the ocean. Two articles in the area of global oceanic precipitation are attached.

Subcooled Liquid Oxygen Cryostat for Magneto-Archimedes Particle Separation by Density

NASA Astrophysics Data System (ADS)

Hilton, D. K.; Celik, D.; Van Sciver, S. W.

2008-03-01

An instrument for the separation of particles by density (sorting) is being developed that uses the magneto-archimedes effect in liquid oxygen. With liquid oxygen strongly paramagnetic, the magneto-archimedes effect is an extension of diamagnetic levitation in the sense of increasing the effective buoyancy of a particle. The instrument will be able to separate ensembles of particles from 100 μm to 100 nm in size, and vertically map or mechanically deliver the separated particles. The instrument requires a column of liquid oxygen that is nearly isothermal, free of thermal convection, subcooled to prevent nucleate boiling, and supported against the strong magnetic field used. Thus, the unique cryostat design that meets these requirements is described in the present article. It consists in part of a column of liquid nitrogen below for cooling the liquid oxygen, with the liquid oxygen pressurized by helium gas to prevent nucleate boiling.

'A potential fifth column': conflicts and struggles for control in the context of local NHS privatization.

PubMed

Aldred, Rachel

2009-09-01

This article uses case study data to discuss how a new procurement policy (Local Improvement Finance Trust, or LIFT) in English primary care may affect general practitioners' control over their work. LIFT, a series of 51 public-private partnerships, will enable over the medium term a shift towards the corporate ownership of surgeries and the creation of polyclinics or 'onestop-shops'. In this article, I explore the struggles over work autonomy and control within these new LIFT structures, as expressed by clinicians and managers in meetings and in research interviews. More generally, I consider how the findings inform debates over the changing position of professionals within increasingly financialized 'local health economies'.

CONDUCT AN INVESTIGATION OF CIGUATERA POISON

DTIC Science & Technology

Research on ciguatera toxin resulted in a satisfactory method for extracting the toxin from fish muscle. Partial purification was also accomplished...by precipitation and silicic acid adsorption. The most precise fractionation of ciguatera toxin is accomplished on a silicic acid column developed...WILL LEAD TO HIGHLY PURIFIED SAMPLES OF CIGUATERA TOXIN. Paper chromatography was examined using fourteen different solvent systems, but none proved

Europe Report, Science and Technology.

DTIC Science & Technology

1986-06-18

amylase, heat stable alpha-amylase and glucoamylase for processing starch as a substrate for 71 glucose and its isomerization to fructose using an...continuous column process under laboratory conditions. We have demonstrated that these preparations isomerize glucose syrups up to 42 percent, converting...food industry is the leading consumer of microbial enzymes devouring about 80 percent of the world production of enzymes -- glucose isomerase, alpha

Assiduous String-Savers: The Idea-Generating Strategies of Professional Expository Writers.

ERIC Educational Resources Information Center

Root, Robert L., Jr.

A study was conducted over a two-year period to investigate the idea-generating strategies of six professional writers and their implications for students. Because finding an idea that leads to a journal or newspaper column is so important to a writer, an attempt was made to learn ways professional writers establish working plans and develop a…

SHOPTALK--A COLUMN OF BRIEF TECHNIQUES, IDEAS, GIMMICKS, AND SUNDRY THOUGHTS ABOUT THE TEACHING OF POETRY.

ERIC Educational Resources Information Center

DONELSON, KENNETH L., ED.

IDEAS FOR THE TEACHING OF POETRY ARE PRESENTED THROUGH SEVERAL BRIEF DESCRIPTIONS OF 16 SUCCESSFULLY-USED TECHNIQUES. THESE INCLUDE (1) TEACHING RUPERT BROOKE'S "THE GREAT LOVER" IN CONJUNCTION WITH CHARLES SCHULTZ'"HAPPINESS IS A WARM PUPPY," (2) USING PICTURES AND MUSIC WITH POETRY, (3) DISCUSSING PHRASES PECULIAR TO SPORTS TO LEAD INTO A…

Review article: Surgical approaches for correction of post-tubercular kyphosis.

PubMed

Panchmatia, Jaykar R; Lenke, Lawrence G; Molloy, Sean; Cheung, Kenneth M C; Kebaish, Khaled M

2015-12-01

This study reviewed the literature regarding the pros and cons of various surgical approaches (anterior, anterolateral, combined, and posterior) for correction of post-tubercular kyphosis. The anterior and anterolateral approaches are effective in improving neurological deficit but not in correcting kyphosis. The combined anterior and posterior approach and the posterior approach combined with 3-column osteotomy achieve good neurological improvement and kyphosis correction. The latter is superior when expertise and facilities are available.

Comments on higher rank Wilson loops in N$$ \\mathcal{N} $$ = 2∗

DOE PAGES

Liu, James T.; Zayas, Leopoldo A. Pando; Zhou, Shan

2018-01-01

For N = 2∗ theory with U(N) gauge group we evaluate expectation values of Wilson loops in representations described by a rectangular Young tableau with n rows and k columns. The evaluation reduces to a two-matrix model and we explain, using a combination of numerical and analytical techniques, the general properties of the eigenvalue distributions in various regimes of parameters (N, λ, n, k) where λ is the ’t Hooft coupling. In the large N limit we present analytic results for the leading and sub-leading contributions. In the particular cases of only one row or one column we reproduce previouslymore » known results for the totally symmetry and totally antisymmetric representations. We also extensively discusss the N = 4 limit of the N = 2∗ theory. While establishing these connections we clarify aspects of various orders of limits and how to relax them; we also find it useful to explicitly address details of the genus expansion. As a result, for the totally symmetric Wilson loop we find new contributions that improve the comparison with the dual holographic computation at one loop order in the appropriate regime.« less

Algorithms used in the Airborne Lidar Processing System (ALPS)

USGS Publications Warehouse

Nagle, David B.; Wright, C. Wayne

2016-05-23

The Airborne Lidar Processing System (ALPS) analyzes Experimental Advanced Airborne Research Lidar (EAARL) data—digitized laser-return waveforms, position, and attitude data—to derive point clouds of target surfaces. A full-waveform airborne lidar system, the EAARL seamlessly and simultaneously collects mixed environment data, including submerged, sub-aerial bare earth, and vegetation-covered topographies.ALPS uses three waveform target-detection algorithms to determine target positions within a given waveform: centroid analysis, leading edge detection, and bottom detection using water-column backscatter modeling. The centroid analysis algorithm detects opaque hard surfaces. The leading edge algorithm detects topography beneath vegetation and shallow, submerged topography. The bottom detection algorithm uses water-column backscatter modeling for deeper submerged topography in turbid water.The report describes slant range calculations and explains how ALPS uses laser range and orientation measurements to project measurement points into the Universal Transverse Mercator coordinate system. Parameters used for coordinate transformations in ALPS are described, as are Interactive Data Language-based methods for gridding EAARL point cloud data to derive digital elevation models. Noise reduction in point clouds through use of a random consensus filter is explained, and detailed pseudocode, mathematical equations, and Yorick source code accompany the report.

Device-scale CFD modeling of gas-liquid multiphase flow and amine absorption for CO 2 capture: Original Research Article: Device-scale CFD modeling of gas-liquid multiphase flow and amine absorption for CO 2 capture

DOE PAGES

Pan, Wenxiao; Galvin, Janine; Huang, Wei Ling; ...

2018-03-25

In this paper we aim to develop a validated device-scale CFD model that can predict quantitatively both hydrodynamics and CO 2 capture efficiency for an amine-based solvent absorber column with random Pall ring packing. A Eulerian porous-media approach and a two-fluid model were employed, in which the momentum and mass transfer equations were closed by literature-based empirical closure models. We proposed a hierarchical approach for calibrating the parameters in the closure models to make them accurate for the packed column. Specifically, a parameter for momentum transfer in the closure was first calibrated based on data from a single experiment. Withmore » this calibrated parameter, a parameter in the closure for mass transfer was next calibrated under a single operating condition. Last, the closure of the wetting area was calibrated for each gas velocity at three different liquid flow rates. For each calibration, cross validations were pursued using the experimental data under operating conditions different from those used for calibrations. This hierarchical approach can be generally applied to develop validated device-scale CFD models for different absorption columns.« less

Dreaming woman: Image, place, and the aesthetics of exile.

PubMed

Greenspan, Rachel

2017-08-01

Looking closely at an Argentine dream interpretation column published in a popular women's magazine from 1948 to 1951, this article examines the role of the dream image in shaping psychoanalytic discourse on femininity and national identity. The column, 'Psychoanalysis Will Help You,' emerged during Juan Domingo Perón's first presidency, featuring verbal interpretations written under the pen name 'Richard Rest,' as well as surreal photomontages by Grete Stern, a German-born, Bauhaus-trained photographer living in exile since 1936. While the column's Jungian text encourages readers' adaptation to the external reality of their social situation, Stern's droll images emphasize the disjuncture between subject and environment, exposing tensions between the experience of exile and the Peronist mission to consolidate an Argentine national identity. Experimenting formally with European avant-garde techniques, Stern presents femininity and nation as conflictive imaginary configurations. This theme resurfaces at the 2013 Venice Biennale, where Nicola Costantino's multimedia installation Eva - Argentina: A Contemporary Metaphor was exhibited alongside Carl Jung's Red Book. Formal contrasts between Stern's use of photomontage, Costantino's projection technique, and Jung's theory of mandala symbolism indicate the divergent ways in which their artwork posits the therapeutic function of the dream image, as well as the role of aesthetic production in psychoanalytic care. Copyright © 2017 Institute of Psychoanalysis.

Device-scale CFD modeling of gas-liquid multiphase flow and amine absorption for CO 2 capture: Original Research Article: Device-scale CFD modeling of gas-liquid multiphase flow and amine absorption for CO 2 capture

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

Pan, Wenxiao; Galvin, Janine; Huang, Wei Ling

In this paper we aim to develop a validated device-scale CFD model that can predict quantitatively both hydrodynamics and CO 2 capture efficiency for an amine-based solvent absorber column with random Pall ring packing. A Eulerian porous-media approach and a two-fluid model were employed, in which the momentum and mass transfer equations were closed by literature-based empirical closure models. We proposed a hierarchical approach for calibrating the parameters in the closure models to make them accurate for the packed column. Specifically, a parameter for momentum transfer in the closure was first calibrated based on data from a single experiment. Withmore » this calibrated parameter, a parameter in the closure for mass transfer was next calibrated under a single operating condition. Last, the closure of the wetting area was calibrated for each gas velocity at three different liquid flow rates. For each calibration, cross validations were pursued using the experimental data under operating conditions different from those used for calibrations. This hierarchical approach can be generally applied to develop validated device-scale CFD models for different absorption columns.« less

Mosaic synaptopathy and functional defects in Cav1.4 heterozygous mice and human carriers of CSNB2

PubMed Central

Michalakis, Stylianos; Shaltiel, Lior; Sothilingam, Vithiyanjali; Koch, Susanne; Schludi, Verena; Krause, Stefanie; Zeitz, Christina; Audo, Isabelle; Lancelot, Marie-Elise; Hamel, Christian; Meunier, Isabelle; Preising, Markus N.; Friedburg, Christoph; Lorenz, Birgit; Zabouri, Nawal; Haverkamp, Silke; Garrido, Marina Garcia; Tanimoto, Naoyuki; Seeliger, Mathias W.; Biel, Martin; Wahl-Schott, Christian A.

2014-01-01

Mutations in CACNA1F encoding the α1-subunit of the retinal Cav1.4 L-type calcium channel have been linked to Cav1.4 channelopathies including incomplete congenital stationary night blindness type 2A (CSNB2), Åland Island eye disease (AIED) and cone-rod dystrophy type 3 (CORDX3). Since CACNA1F is located on the X chromosome, Cav1.4 channelopathies are typically affecting male patients via X-chromosomal recessive inheritance. Occasionally, clinical symptoms have been observed in female carriers, too. It is currently unknown how these mutations lead to symptoms in carriers and how the retinal network in these females is affected. To investigate these clinically important issues, we compared retinal phenotypes in Cav1.4-deficient and Cav1.4 heterozygous mice and in human female carrier patients. Heterozygous Cacna1f carrier mice have a retinal mosaic consistent with differential X-chromosomal inactivation, characterized by adjacent vertical columns of affected and non-affected wild-type-like retinal network. Vertical columns in heterozygous mice are well comparable to either the wild-type retinal network of normal mice or to the retina of homozygous mice. Affected retinal columns display pronounced rod and cone photoreceptor synaptopathy and cone degeneration. These changes lead to vastly impaired vision-guided navigation under dark and normal light conditions and reduced retinal electroretinography (ERG) responses in Cacna1f carrier mice. Similar abnormal ERG responses were found in five human CACNA1F carriers, four of which had novel mutations. In conclusion, our data on Cav1.4 deficient mice and human female carriers of mutations in CACNA1F are consistent with a phenotype of mosaic CSNB2. PMID:24163243

Husbandry Emissions Estimation: Fusion of Mobile Surface and Airborne Remote Sensing and Mobile Surface In Situ Measurements

NASA Astrophysics Data System (ADS)

Leifer, I.; Hall, J. L.; Melton, C.; Tratt, D. M.; Chang, C. S.; Buckland, K. N.; Frash, J.; Leen, J. B.; Van Damme, M.; Clarisse, L.

2017-12-01

Emissions of methane and ammonia from intensive animal husbandry are important drivers of climate and photochemical and aerosol pollution. Husbandry emission estimates are somewhat uncertain because of their dependence on practices, temperature, micro-climate, and other factors, leading to variations in emission factors up to an order-of-magnitude. Mobile in situ measurements are increasingly being applied to derive trace gas emissions by Gaussian plume inversion; however, inversion with incomplete information can lead to erroneous emissions and incorrect source location. Mobile in situ concentration and wind data and mobile remote sensing column data from the Chino Dairy Complex in the Los Angeles Basin were collected near simultaneously (within 1-10 s, depending on speed) while transecting plumes, approximately orthogonal to winds. This analysis included airborne remote sensing trace gas information. MISTIR collected vertical column FTIR data simultaneously with in situ concentration data acquired by the AMOG-Surveyor while both vehicles traveled in convoy. The column measurements are insensitive to the turbulence characterization needed in Gaussian plume inversion of concentration data and thus provide a flux reference for evaluating in situ data inversions. Four different approaches were used on inversions for a single dairy, and also for the aggregate dairy complex plume. Approaches were based on differing levels of "knowledge" used in the inversion from solely the in situ platform and a single gas to a combination of information from all platforms and multiple gases. Derived dairy complex fluxes differed significantly from those estimated by other studies of the Chino complex. Analysis of long term satellite data showed that this most likely results from seasonality effects, highlighting the pitfalls of applying annualized extensions of flux measurements to a single campaign instantiation.

Reliability of high I/O high density CCGA interconnect electronic packages under extreme thermal environments

NASA Astrophysics Data System (ADS)

Ramesham, Rajeshuni

2012-03-01

Ceramic column grid array (CCGA) packages have been increasing in use based on their advantages such as high interconnect density, very good thermal and electrical performances, compatibility with standard surfacemount packaging assembly processes, and so on. CCGA packages are used in space applications such as in logic and microprocessor functions, telecommunications, payload electronics, and flight avionics. As these packages tend to have less solder joint strain relief than leaded packages or more strain relief over lead-less chip carrier packages, the reliability of CCGA packages is very important for short-term and long-term deep space missions. We have employed high density CCGA 1152 and 1272 daisy chained electronic packages in this preliminary reliability study. Each package is divided into several daisy-chained sections. The physical dimensions of CCGA1152 package is 35 mm x 35 mm with a 34 x 34 array of columns with a 1 mm pitch. The dimension of the CCGA1272 package is 37.5 mm x 37.5 mm with a 36 x 36 array with a 1 mm pitch. The columns are made up of 80% Pb/20%Sn material. CCGA interconnect electronic package printed wiring polyimide boards have been assembled and inspected using non-destructive x-ray imaging techniques. The assembled CCGA boards were subjected to extreme temperature thermal atmospheric cycling to assess their reliability for future deep space missions. The resistance of daisy-chained interconnect sections were monitored continuously during thermal cycling. This paper provides the experimental test results of advanced CCGA packages tested in extreme temperature thermal environments. Standard optical inspection and x-ray non-destructive inspection tools were used to assess the reliability of high density CCGA packages for deep space extreme temperature missions.

The Seasonal Cycle of Water Vapour on Mars from Assimilation of Thermal Emission Spectrometer Data

NASA Technical Reports Server (NTRS)

Steele, Liam J.; Lewis, Stephen R.; Patel, Manish R.; Montmessin, Franck; Forget, Francois; Smith, Michael D.

2014-01-01

We present for the first time an assimilation of Thermal Emission Spectrometer (TES) water vapour column data into a Mars global climate model (MGCM). We discuss the seasonal cycle of water vapour, the processes responsible for the observed water vapour distribution, and the cross-hemispheric water transport. The assimilation scheme is shown to be robust in producing consistent reanalyses, and the global water vapour column error is reduced to around 2-4 pr micron depending on season. Wave activity is shown to play an important role in the water vapour distribution, with topographically steered flows around the Hellas and Argyre basins acting to increase transport in these regions in all seasons. At high northern latitudes, zonal wavenumber 1 and 2 stationary waves during northern summer are responsible for spreading the sublimed water vapour away from the pole. Transport by the zonal wavenumber 2 waves occurs primarily to the west of Tharsis and Arabia Terra and, combined with the effects of western boundary currents, this leads to peak water vapour column abundances here as observed by numerous spacecraft. A net transport of water to the northern hemisphere over the course of one Mars year is calculated, primarily because of the large northwards flux of water vapour which occurs during the local dust storm around L(sub S) = 240-260deg. Finally, outlying frost deposits that surround the north polar cap are shown to be important in creating the peak water vapour column abundances observed during northern summer.

Very high pressure liquid chromatography using core-shell particles: quantitative analysis of fast gradient separations without post-run times.

PubMed

Stankovich, Joseph J; Gritti, Fabrice; Stevenson, Paul G; Beaver, Lois A; Guiochon, Georges

2014-01-17

Five methods for controlling the mobile phase flow rate for gradient elution analyses using very high pressure liquid chromatography (VHPLC) were tested to determine thermal stability of the column during rapid gradient separations. To obtain rapid separations, instruments are operated at high flow rates and high inlet pressure leading to uneven thermal effects across columns and additional time needed to restore thermal equilibrium between successive analyses. The purpose of this study is to investigate means to minimize thermal instability and obtain reliable results by measuring the reproducibility of the results of six replicate gradient separations of a nine component RPLC standard mixture under various experimental conditions with no post-run times. Gradient separations under different conditions were performed: constant flow rates, two sets of constant pressure operation, programmed flow constant pressure operation, and conditions which theoretically should yield a constant net heat loss at the column's wall. The results show that using constant flow rates, programmed flow constant pressures, and constant heat loss at the column's wall all provide reproducible separations. However, performing separations using a high constant pressure with programmed flow reduces the analysis time by 16% compared to constant flow rate methods. For the constant flow rate, programmed flow constant pressure, and constant wall heat experiments no equilibration time (post-run time) was required to obtain highly reproducible data. Copyright © 2013 Elsevier B.V. All rights reserved.

Rural hospital focus: accommodation.

PubMed

Couper, I D

2003-01-01

Rural and Remote Health is committed to the task of providing a freely accessible, international, peer-reviewed evidence base for rural and remote health practice. Inherent in this aim is a recognition of the universal nature of rural health issues that transcends both regional interests and local culture. While RRH is already publishing peer-reviewed material, the Editorial Board believes many articles of potential worth are largely inaccessible due to their primary publication in small-circulation, paper-based journals whose readership is geographically limited. In order to augment our already comprehensive, international evidence base, the RRH Editorial Board has decided to republish, with permission, selected articles from such journals. This will also give worthwhile small-circulation articles the wide audience only a web-based journal can offer. The RRH editorial team encourages journal users to nominate similar, suitable articles from their own world region. This article 'Rural hospital focus: accommodation', is third in our series. It first appeared in South African Family Practice 2000; 22 (7), and is reproduced here in its original form, with kind permission of both publisher and author, prominent South African rural doctor, Professor Ian Couper. 'Rural hospital focus' was the title of the SAFP column which presented this article.

[Exploration of nursing art and aesthetic experiences: cross-disciplinary links and dialogues].

PubMed

Sheu, Shuh-Jen

2013-08-01

Interdisciplinary understanding is crucial for readers today. This article integrates the ideas of four care-aesthetics-column writers in order to illustrate and discuss nursing art and aesthetic care experiences in a cross-disciplinary conversation. This article reflects critically on the art, culture, and nature of nursing in the five themes of: 1) the shape of nursing knowledge, "science" or "art"?; 2) the caring arts: passively regulative or consciously creative labor?; 3) busy hospital workers: a landscape of persons and objects or the creators of the scenery?; 4) nursing skills, arts, and the Tao; and 5) art liberation: is the nursing profession in need of a revolution or fundamental reform? This article utilizes diverse and occasionally contradictory points of view together with practical examples in order to encourage readers to interlink their disparate professional nursing skills and draw aesthetic knowledge from multiple sources and experiences.

EDTA-assisted leaching of Pb and Cd from contaminated soil.

PubMed

Qiao, Jiangbo; Sun, Huimin; Luo, Xiuhua; Zhang, Wang; Mathews, Shiny; Yin, Xianqiang

2017-01-01

Lead (Pb) and cadmium (Cd) contamination of soil and its harmful effects on human and environmental health have been one concern. In this study, batch and column leaching experiments were conducted to investigate the effects of two EDTA-assisted leaching methods, continuous and intermittent (dry-wet alternate), on the removal of Pb and Cd from contaminated soil. Total content and fractions of Pb and Cd at every 1 cm soil column depth were analyzed before and after the leaching. The results indicated that continuous leaching removed 75.43% of Pb (19.370 mg) and 53.21% of Cd (6.168 mg) and intermittent leaching removed 78.08% of Pb (20.051 mg) and 57.37% of Cd (6.650 mg), which showed intermittent leaching removed more Pb and Cd, but didn't differ significantly (P > 0.05) compared to the continuous leaching. In both leaching methods, total Pb and Cd content in all soil depths reduced after leaching. The two leaching methods made no significant differences in Pb and Cd distributions at different depths of the soil column. Copyright © 2016 Elsevier Ltd. All rights reserved.

Rapid ionization of the environment of SN 1987A

NASA Technical Reports Server (NTRS)

Raga, A. C.

1987-01-01

It has been suggested by some authors that IUE observations of the supernova SN 1987A show the presence of a strong component of the interstellar C IV 1550 and Si IV 1393 absorption lines at a velocity that approximately corresponds to the velocity of the LMC. It is possible that this component might come from originally neutral (or at least not very highly ionized) gas which has been photoionized by the initially very strong ionizing radiation field of the supernova. Theoretical considerations of this scenario lead to the study of fast (with velocities of about c) ionization fronts. It is shown that for reasonable model parameters it is possible to obtain considerably large C IV column densities, in agreement with the IUE observations. On the other hand, the models do not so easily predict the large Si IV column densities that are also obtained from the IUE observations. It is found that only models in which the interstellar medium surrounding SN 1987A is initially composed of already ionized hydrogen and helium predict substantial Si IV column densities. This result provides an interesting prediction of the ionization state of the environment of the presupernova star.

A new approach for bioethanol production from sugarcane bagasse using hydrodynamic cavitation assisted-pretreatment and column reactors.

PubMed

Terán Hilares, Ruly; Kamoei, Douglas Viana; Ahmed, Muhammad Ajaz; da Silva, Silvio Silvério; Han, Jong-In; Santos, Júlio César Dos

2018-05-01

Hydrodynamic cavitation (HC) was adopted to assist alkaline-hydrogen peroxide pretreatment of sugarcane bagasse (SCB). In the following condition: 0.29 M of NaOH, 0.78% (v/v) of H 2 O 2 , 9.95 min of process time and 3 bar of inlet pressure, 95.4% of digestibility of cellulosic fraction was achieved. To take the best use of the pretreated biomass, the overall process was intensified by way of employing a packed bed flow-through column reactor and thus enabling to handle a high solid loading of 20%, thereby leading to cellulose and hemicellulose conversions to 74.7% and 75%, respectively. In the fermentation step, a bubble column reactor was introduced to maximize ethanol production from the pretreated SCB by Scheffersomyces stipitis NRRL-Y7124, resulting in 31.50 g/L of ethanol, 0.49 g/g of ethanol yield and 0.68 g/L.h of productivity. All this showed that our HC-assisted NaOH-H 2 O 2 pretreatment strategy along with the process intensification approach might offer an option for SCB-based biorefineries. Copyright © 2018 Elsevier B.V. All rights reserved.

Endosulfan leaching from Typic Argiudolls in soybean tillage areas and groundwater pollution implications.

PubMed

Grondona, Sebastián I; Gonzalez, Mariana; Martínez, Daniel E; Massone, Héctor E; Miglioranza, Karina S B

2014-06-15

Endosulfan has been recently added to Persistent Organic Pollutants (POPs) list and due to its extensive and massive use and environmental persistence constitutes a potential hazard to groundwater resources. Undisturbed soil columns were used to evaluate endosulfan leaching in two series of Typic Argiudolls considering natural and agricultural land use. Columns were spiked with 10μgL(-1) of technical endosulfan and eluted under saturated flow with five pore volumes of distilled water. Alfa and beta isomer residues were detected in the upper soil level, with decreasing values through the profile, being influenced by soil texture and land use. The endosulfan sulfate metabolite was mainly found in the upper level linked to high dehydrogenase activity. Results from leachates (total endosulfan 27-87ngL(-1)) showed higher α-isomer mobility, and suggest alkaline hydrolysis of both endosulfan isomers. The agricultural use modified the physico-chemical properties and structure of soils leading to vertical migration of endosulfan isomers under saturated conditions. Intact column test provided information close to field data showing its utility for the assessment of groundwater pollution by endosulfan. Copyright © 2014 Elsevier B.V. All rights reserved.

Algebraic motion of vertically displacing plasmas

NASA Astrophysics Data System (ADS)

Pfefferlé, D.; Bhattacharjee, A.

2018-02-01

The vertical motion of a tokamak plasma is analytically modelled during its non-linear phase by a free-moving current-carrying rod inductively coupled to a set of fixed conducting wires or a cylindrical conducting shell. The solutions capture the leading term in a Taylor expansion of the Green's function for the interaction between the plasma column and the surrounding vacuum vessel. The plasma shape and profiles are assumed not to vary during the vertical drifting phase such that the plasma column behaves as a rigid body. In the limit of perfectly conducting structures, the plasma is prevented to come in contact with the wall due to steep effective potential barriers created by the induced Eddy currents. Resistivity in the wall allows the equilibrium point to drift towards the vessel on the slow timescale of flux penetration. The initial exponential motion of the plasma, understood as a resistive vertical instability, is succeeded by a non-linear "sinking" behaviour shown to be algebraic and decelerating. The acceleration of the plasma column often observed in experiments is thus concluded to originate from an early sharing of toroidal current between the core, the halo plasma, and the wall or from the thermal quench dynamics precipitating loss of plasma current.

Noise Reduction Techniques and Scaling Effects towards Photon Counting CMOS Image Sensors

PubMed Central

Boukhayma, Assim; Peizerat, Arnaud; Enz, Christian

2016-01-01

This paper presents an overview of the read noise in CMOS image sensors (CISs) based on four-transistors (4T) pixels, column-level amplification and correlated multiple sampling. Starting from the input-referred noise analytical formula, process level optimizations, device choices and circuit techniques at the pixel and column level of the readout chain are derived and discussed. The noise reduction techniques that can be implemented at the column and pixel level are verified by transient noise simulations, measurement and results from recently-published low noise CIS. We show how recently-reported process refinement, leading to the reduction of the sense node capacitance, can be combined with an optimal in-pixel source follower design to reach a sub-0.3erms- read noise at room temperature. This paper also discusses the impact of technology scaling on the CIS read noise. It shows how designers can take advantage of scaling and how the Metal-Oxide-Semiconductor (MOS) transistor gate leakage tunneling current appears as a challenging limitation. For this purpose, both simulation results of the gate leakage current and 1/f noise data reported from different foundries and technology nodes are used.

Liposome retention in size exclusion chromatography

PubMed Central

Ruysschaert, Tristan; Marque, Audrey; Duteyrat, Jean-Luc; Lesieur, Sylviane; Winterhalter, Mathias; Fournier, Didier

2005-01-01

Background Size exclusion chromatography is the method of choice for separating free from liposome-encapsulated molecules. However, if the column is not presaturated with lipids this type of chromatography causes a significant loss of lipid material. To date, the mechanism of lipid retention is poorly understood. It has been speculated that lipid binds to the column material or the entire liposome is entrapped inside the void. Results Here we show that intact liposomes and their contents are retained in the exclusion gel. Retention depends on the pore size, the smaller the pores, the higher the retention. Retained liposomes are not tightly fixed to the beads and are slowly released from the gels upon direct or inverted eluent flow, long washing steps or column repacking. Further addition of free liposomes leads to the elution of part of the gel-trapped liposomes, showing that the retention is transitory. Trapping reversibility should be related to a mechanism of partitioning of the liposomes between the stationary phase, water-swelled polymeric gel, and the mobile aqueous phase. Conclusion Retention of liposomes by size exclusion gels is a dynamic and reversible process, which should be accounted for to control lipid loss and sample contamination during chromatography. PMID:15885140

Determination of Gonyautoxin-4 in Echinoderms and Gastropod Matrices by Conversion to Neosaxitoxin Using 2-Mercaptoethanol and Post-Column Oxidation Liquid Chromatography with Fluorescence Detection

PubMed Central

Silva, Marisa; Rey, Verónica; Botana, Ana; Vasconcelos, Vitor; Botana, Luis

2015-01-01

Paralytic Shellfish Toxin blooms are common worldwide, which makes their monitoring crucial in the prevention of poisoning incidents. These toxins can be monitored by a variety of techniques, including mouse bioassay, receptor binding assay, and liquid chromatography with either mass spectrometric or pre- or post-column fluorescence detection. The post-column oxidation liquid chromatography with fluorescence detection method, used routinely in our laboratory, has been shown to be a reliable method for monitoring paralytic shellfish toxins in mussel, scallop, oyster and clam species. However, due to its high sensitivity to naturally fluorescent matrix interferences, when working with unconventional matrices, there may be problems in identifying toxins because of naturally fluorescent interferences that co-elute with the toxin peaks. This can lead to erroneous identification. In this study, in order to overcome this challenge in echinoderm and gastropod matrices, we optimized the conversion of Gonyautoxins 1 and 4 to Neosaxitoxin with 2-mercaptoethanol. We present a new and less time-consuming method with a good recovery (82.2%, RSD 1.1%, n = 3), requiring only a single reaction step. PMID:26729166

VizieR Online Data Catalog: Visible colors of Centaurs and KBOs (Peixinho+, 2015)

NASA Astrophysics Data System (ADS)

Peixinho, N.; Delsanti, A.; Doressoundiram, A.

2015-02-01

Table 2: significant Spearman-rho correlations detected between all colors and all orbital parameters of Centaurs, scattered disk objects, scattered or detached objects, Plutinos, other resonants, classical KBOs, binary or multiple KBOs, KBOs (without Haumea family and retrograde orbits), all objects (also without Haumea family and retrograde orbits), and KBOs except classical KBOs (also without Haumea family and retrograde orbits). First and second columns indicate the variables, third column the number of objects with both variables measured, forth column indicate the correlation value and its 68.2% error interval, fifth column indicates the p-value of the correlation, sixth column indicate the equivalent confidence level of the p-value in Gaussian sigmas, columns seven to nine indicate the detail of the False Discovery Correction for confidence levels of 2.5σ and 3σ (see Sect. 3.4), tenth column indicates the maximum detectable rho at a 2.5σ confidence level with a 10% risk of missing it, eleventh column indicates the maximum detectable rho at a 3σ confidence level with a 10% risk of missing it (see Sect. 3.2) Table 5: Compilation of R-band absolute magnitude, not corrected for the phase-angle, of Spectral gradient, B-V, V-R, R-I, V-I, B-I, B-R, and corresponding orbital and orbital related parameters of 366 Centaurs and KBOs. For each object/observation, we computed the reflectance spectrum using equation (3) from Delsanti et al. (2001A&A...380..347D), when 2 or more filters were available. The resulting spectra were manually checked, and obviously deviant data from a given filter were removed from the dataset. Color indexes are computed within one given epoch, leading to colors obtained from "simultaneous" photometry (the different bands were observed over a maximum timespan of 2 hours). Then the average colors indexes and their one σ errors from different papers and epochs are computed for each object using equations (1) and (2) from Hainaut and Delsanti (2002A&A...389..641H), providing more accurate estimates when multiple measurements are available. Absolute magnitude in R band (HR) are computed for each object/epoch whenever a R-band magnitude is available, using: HR=R-5log(rΔ), where R is the R-band magnitude, r and Δ the helio- and geocentric distances at the time of observations, respectively.Different values for a given object were also averaged using the aforementioned equations (1) and (2). We did not correct for any phase effect. (5 data files).

Outbreak Column 16: Cognitive errors in outbreak decision making.

PubMed

Curran, Evonne T

2015-01-01

During outbreaks, decisions must be made without all the required information. People, including infection prevention and control teams (IPCTs), who have to make decisions during uncertainty use heuristics to fill the missing data gaps. Heuristics are mental model short cuts that by-and-large enable us to make good decisions quickly. However, these heuristics contain biases and effects that at times lead to cognitive (thinking) errors. These cognitive errors are not made to deliberately misrepresent any given situation; we are subject to heuristic biases when we are trying to perform optimally. The science of decision making is large; there are over 100 different biases recognised and described. Outbreak Column 16 discusses and relates these heuristics and biases to decision making during outbreak prevention, preparedness and management. Insights as to how we might recognise and avoid them are offered.

Phototoxicity testing by online irradiation and HPLC.

PubMed

Schröder, Sven; Surmann, J P

2006-11-01

A high-performance liquid chromatography (HPLC) system was developed for the determination of drug photostability and phototoxicity based on an automated column-switching system with aqueous online UV-A irradiation and hyphenated organic separation of the drug and its photoproducts. The photoreactor is built with an poly(ethylene-co-tetrafluoroethylene) (ETFE) reaction coil knitted around a UV-A light source. The chromatographic separation was performed with two special C18 columns, which are also suitable for using with pure water as eluent. Degradation of chlorpromazine (CPZ) by ultraviolet light was investigated at pH 7 and pH 3. Furthermore chlorpromazine was irradiated in the presence of guanosine-5-monophosphate (GMP) in pH 7 buffered solution, leading to a new photoproduct. In the pH 3 irradiation studies of CPZ and GMP, no reaction was detected between the molecules.