1,169 research outputs found

    Performances of PA hollow fiber membrane with the CTA flat sheet membrane for forward osmosis process

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    © 2013, © 2013 Balaban Desalination Publications. All rights reserved. Abstract: Fertilizer drawn forward osmosis desalination has been earlier explored using flat sheet forward osmosis (FSFO) membrane, which highlighted flux and reverse solute flux (RSF) performance. This study evaluated and compared the performances of a newly developed polyamide (PA)-based hollow fiber forward osmosis (HFFO) membrane and cellulose triacetate FSFO membrane. Both membranes were evaluated for pure water permeability, salt rejection rate (1,000 mg/L NaCl) in RO mode. Physical structure and morphology were further examined using scanning electron micrograph (SEM). SEM images revealed that the overall thickness of the HFFO and FSFO membranes was 152 and 91 μm, respectively. Flux and RSF performances of these two membranes were evaluated using nine fertilizer DS as NH4Cl, KNO3, KCl, (NH4)2SO4, Ca(NO3)2, NH4H2PO4, (NH4)2HPO4, NaNO3, and CO(NH2)2 in active layer–feed solution membrane orientation. HFFO membrane clearly showed better performance for water flux with five DS ((NH4)2SO4, NH4H2PO4, KNO3, CO(NH2)2, and NaNO3) as they showed up to 66% increase in flux. Beside thick PA active layer of HFFO membrane, higher water flux outcome for forward osmosis (FO) process further highlighted the significance of the nature of support layer structure, the thickness and surface chemistry of the active layer of the membrane in the FO process. On the other hand, most DS showed lower RSF with HFFO membrane with the exception of Ca(NO3)2. Most of DS having monovalent cation and anions showed significantly lower RSF with HFFO membrane

    Two-dimensional imaging of edge-localized modes in KSTAR plasmas unperturbed and perturbed by n=1 external magnetic fields

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    The temporal evolution of edge-localized modes (ELMs) has been studied using a 2-D electron cyclotron emission imaging system in the KSTAR tokamak. The ELMs are observed to evolve in three distinctive stages: the initial linear growth of multiple filamentary structures having a net poloidal rotation, the interim state of regularly spaced saturated filaments, and the final crash through a short transient phase characterized by abrupt changes in the relative amplitudes and distance among filaments. The crash phase, typically consisted of multiple bursts of a single filament, involves a complex dynamics, poloidal elongation of the bursting filament, development of a fingerlike bulge, and fast localized burst through the finger. Substantial alterations of the ELM dynamics, such as mode number, poloidal rotation, and crash time scale, have been observed under external magnetic perturbations with the toroidal mode number n = 1. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.3694842]X1125sciescopu

    Influence of the process parameters on hollow fiber-forward osmosis membrane performances

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    Š 2014 Balaban Desalination Publications. All rights reserved. Continued efforts are made in improving the performance of the low-cost forward osmosis (FO) membrane process which utilizes naturally available osmotic pressure of the draw solution (DS) as the driving force. Selection of a suitable DS and development of a better performing membrane remained the main research focus. In this study, the performance of a hollow fiber forward osmosis (HFFO) membrane was evaluated with respect to various operating conditions such as different cross-flow directions, membrane orientation, solution properties, and solution flow rates (Reynolds number). The study observed that operating parameters significantly affect the performance of the FO process. FO comparatively showed better performance at counter-current orientation. NaCl, KCl, and NH4Cl were evaluated as DS carrying common anion. Properties of the anionic part of the DS were found important for flux outcome, whereas reverse solute flux (RSF) was largely influenced by the properties of DS cationic part. FO was operated at different DS and feed solution (FS) flow rates and FO outcome was assessed for varying DS and FS Reynolds number ratio. FO showed better flux outcome as Re ratio for DS and FS decreases and vice versa. Results indicated that by adjusting FO processes conditions, HFFO membrane could achieve significantly lower specific RSF and higher water flux outcome. It was observed that using 2 M NaCl as DS and deionized water as FS, HFFO successfully delivered flux of 62.9 LMH which is significantly high compared to many FO membranes reported in the literature under the active layer-DS membrane orientation mode

    Appearance and Dynamics of Helical Flux Tubes under Electron Cyclotron Resonance Heating in the Core of KSTAR Plasmas

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    Dual (or sometimes multiple) flux tubes (DFTs) have been observed in the core of sawtoothing KSTAR tokamak plasmas with electron cyclotron resonance heating. The time evolution of the flux tubes visualized by a 2D electron cyclotron emission imaging diagnostic typically consists of four distinctive phases: (1) growth of one flux tube out of multiple small flux tubes during the initial buildup period following a sawtooth crash, resulting in a single dominant flux tube along the m/n = 1/1 helical magnetic field lines, (2) sudden rapid growth of another flux tube via a fast heat transfer from the first one, resulting in approximately identical DFTs, (3) coalescence of the two flux tubes into a single m/n = 1/1 flux tube resembling the internal kink mode in the normal sawteeth, which is explained by a model of two currentcarrying wires confined on a flux surface, and (4) fast localized crash of the merged flux tube similar to the standard sawtooth crash. The dynamics of the DFTs implies that the internal kink mode is not a unique prerequisite to the sawtooth crash, providing a new insight on the control of the sawtooth.X112217Ysciescopu

    Improved annotation of 3' untranslated regions and complex loci by combination of strand-specific direct RNA sequencing, RNA-seq and ESTs

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    The reference annotations made for a genome sequence provide the framework for all subsequent analyses of the genome. Correct annotation is particularly important when interpreting the results of RNA-seq experiments where short sequence reads are mapped against the genome and assigned to genes according to the annotation. Inconsistencies in annotations between the reference and the experimental system can lead to incorrect interpretation of the effect on RNA expression of an experimental treatment or mutation in the system under study. Until recently, the genome-wide annotation of 3-prime untranslated regions received less attention than coding regions and the delineation of intron/exon boundaries. In this paper, data produced for samples in Human, Chicken and A. thaliana by the novel single-molecule, strand-specific, Direct RNA Sequencing technology from Helicos Biosciences which locates 3-prime polyadenylation sites to within +/- 2 nt, were combined with archival EST and RNA-Seq data. Nine examples are illustrated where this combination of data allowed: (1) gene and 3-prime UTR re-annotation (including extension of one 3-prime UTR by 5.9 kb); (2) disentangling of gene expression in complex regions; (3) clearer interpretation of small RNA expression and (4) identification of novel genes. While the specific examples displayed here may become obsolete as genome sequences and their annotations are refined, the principles laid out in this paper will be of general use both to those annotating genomes and those seeking to interpret existing publically available annotations in the context of their own experimental dataComment: 44 pages, 9 figure

    Dynamics of Immune System Gene Expression upon Bacterial Challenge and Wounding in a Social Insect (Bombus terrestris)

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    The innate immune system which helps individuals to combat pathogens comprises a set of genes representing four immune system pathways (Toll, Imd, JNK and JAK/STAT). There is a lack of immune genes in social insects (e.g. honeybees) when compared to Diptera. Potentially, this might be compensated by an advanced system of social immunity (synergistic action of several individuals). The bumble bee, Bombus terrestris, is a primitively eusocial species with an annual life cycle and colonies headed by a single queen. We used this key pollinator to study the temporal dynamics of immune system gene expression in response to wounding and bacterial challenge

    At-risk registers integrated into primary care to stop asthma crises in the UK (ARRISA-UK): study protocol for a pragmatic, cluster randomised trial with nested health economic and process evaluations

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    Background: Despite effective treatments and long-standing management guidelines, there are approximately 1400 hospital admissions for asthma weekly in the United Kingdom (UK), many of which could be avoided. In our previous research, a secondary analysis of the intervention (ARRISA) suggested an improvement in the management of at-risk asthma patients in primary care. ARRISA involved identifying individuals at risk of adverse asthma events, flagging their electronic health records, training practice staff to develop and implement practice-wide processes of care when alerted by the flag, plus motivational reminders. We now seek to determine the effectiveness and cost-effectiveness of ARRISA in reducing asthma-related crisis events. Methods: We are undertaking a pragmatic, two-arm, multicentre, cluster randomised controlled trial, plus health economic and process evaluation. We will randomise 270 primary care practices from throughout the UK covering over 10,000 registered patients with ‘at-risk asthma’ identified according to a validated algorithm. Staff in practices randomised to the intervention will complete two 45-min eLearning modules (an individually completed module giving background to ARRISA and a group-completed module to develop practice-wide pathways of care) plus a 30-min webinar with other practices. On completion of training at-risk patients’ records will be coded so that a flag appears whenever their record is accessed. Practices will receive a phone call at 4 weeks and a reminder video at 6 weeks and 6 months. Control practices will continue to provide usual care. We will extract anonymised routine patient data from primary care records (with linkage to secondary care data) to determine the percentage of at-risk patients with an asthma-related crisis event (accident and emergency attendances, hospitalisations and deaths) after 12 months (primary outcome). We will also capture the time to crisis event, all-cause hospitalisations, asthma control and any changes in practice asthma management for at-risk and all patients with asthma. Cost-effectiveness analysis and mixed-methods process evaluations will also be conducted. Discussion: This study is novel in terms of using a practice-wide intervention to target and engage with patients at risk from their asthma and is innovative in the use of routinely captured data with record linkage to obtain trial outcomes. Trial registration: ISRCTN95472706. Registered on 5 December 2014

    Protein Profile Changes during Porcine Oocyte Aging and Effects of Caffeine on Protein Expression Patterns

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    It has been shown that oocyte aging critically affects reproduction and development. By using proteomic tools, in the present study, changes in protein profiles during porcine oocyte aging and effects of caffeine on oocyte aging were investigated. By comparing control MII oocytes with aging MII oocytes, we identified 23 proteins that were up-regulated and 3 proteins that were down-regulated during the aging process. In caffeine-treated oocytes, 6 proteins were identified as up-regulated and 12 proteins were identified as down-regulated. A total of 38 differentially expressed proteins grouped into 5 regulation patterns were determined to relate to the aging and anti-aging process. By using the Gene Ontology system, we found that numerous functional gene products involved in metabolism, stress response, reactive oxygen species and cell cycle regulation were differentially expressed during the oocyte aging process, and most of these proteins are for the first time reported in our study, including 2 novel proteins. In addition, several proteins were found to be modified during oocyte aging. These data contribute new information that may be useful for future research on cellular aging and for improvement of oocyte quality

    Performance of CMS muon reconstruction in pp collision events at sqrt(s) = 7 TeV

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    The performance of muon reconstruction, identification, and triggering in CMS has been studied using 40 inverse picobarns of data collected in pp collisions at sqrt(s) = 7 TeV at the LHC in 2010. A few benchmark sets of selection criteria covering a wide range of physics analysis needs have been examined. For all considered selections, the efficiency to reconstruct and identify a muon with a transverse momentum pT larger than a few GeV is above 95% over the whole region of pseudorapidity covered by the CMS muon system, abs(eta) < 2.4, while the probability to misidentify a hadron as a muon is well below 1%. The efficiency to trigger on single muons with pT above a few GeV is higher than 90% over the full eta range, and typically substantially better. The overall momentum scale is measured to a precision of 0.2% with muons from Z decays. The transverse momentum resolution varies from 1% to 6% depending on pseudorapidity for muons with pT below 100 GeV and, using cosmic rays, it is shown to be better than 10% in the central region up to pT = 1 TeV. Observed distributions of all quantities are well reproduced by the Monte Carlo simulation.Comment: Replaced with published version. Added journal reference and DO
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