Measurement of renal glomerular filtration rate using labelled substances with compartmental analysis

International Nuclear Information System (INIS)

Eberstadt, P.L.

1981-10-01

Using a model for the two-compartmental open system and experiments on animals (rabbits and dogs) as well as on human healthy volunteers, an attempt was made to study the advantages and limitations of different radionuclide methods for glomerular filtration rate determination. Labelled compounds used in different combinations were: 3 H-inulin, sup(113m)In-EDTA, 131 I-iothalamate, sup(99m)Tc-DTPA and 14 C-creatinine. The results of the study lead to some working hypotheses concerning the value of creatinine and other labelled substances in the measurement of glomerular filtration rate in clinical practice. The advantages and disadvantages of individual methods summarized in the final report are generally in agreement with the present views of many research workers. Also the hypothesis can be justified that the different labelled compounds which have been studied might be handled independently by the membranes involved but at the long run produce similar homeostatic balance

Carbon Nanotube Membranes: Synthesis, Properties, and Future Filtration Applications

Directory of Open Access Journals (Sweden)

Md. Harun-Or Rashid

2017-05-01

Full Text Available Over the course of the past decade, there has been growing interest in the development of different types of membranes composed of carbon nanotubes (CNTs, including buckypapers and composite materials, for an ever-widening range of filtration applications. This article provides an overview of how different types of CNT membranes are prepared and the results obtained from investigations into their suitability for different applications. The latter involve the removal of small particles from air samples, the filtration of aqueous solutions containing organic compounds and/or bacteria, and the separation of individual liquids present in mixtures. A growing number of reports have demonstrated that the incorporation of CNTs into composite membranes confers an improved resistance to fouling caused by biomacromolecules and bacteria. These results are discussed, along with evidence that demonstrates it is possible to further reduce fouling by taking advantage of the inherent conductivity of composite membranes containing CNTs, as well as by using different types of electrochemical stimuli.

Determination of chromate ion in drilling mud filtrates

International Nuclear Information System (INIS)

Whitfill, D.

1980-01-01

A method of determining the amount of chromate ion in an aqueous drilling mud filtrate containing organic color bodies such as lignosulfate wherein the method comprises: (A) treating the aqueous filtrate with an effective amount of hydrogen peroxide to destroy said color bodies, and (B) measuring the amount of chromate ion in the filtrate by means of a spectrophotometer

A method to generate equivalent energy spectra and filtration models based on measurement for multidetector CT Monte Carlo dosimetry simulations

International Nuclear Information System (INIS)

Turner, Adam C.; Zhang Di; Kim, Hyun J.; DeMarco, John J.; Cagnon, Chris H.; Angel, Erin; Cody, Dianna D.; Stevens, Donna M.; Primak, Andrew N.; McCollough, Cynthia H.; McNitt-Gray, Michael F.

2009-01-01

The purpose of this study was to present a method for generating x-ray source models for performing Monte Carlo (MC) radiation dosimetry simulations of multidetector row CT (MDCT) scanners. These so-called ''equivalent'' source models consist of an energy spectrum and filtration description that are generated based wholly on the measured values and can be used in place of proprietary manufacturer's data for scanner-specific MDCT MC simulations. Required measurements include the half value layers (HVL 1 and HVL 2 ) and the bowtie profile (exposure values across the fan beam) for the MDCT scanner of interest. Using these measured values, a method was described (a) to numerically construct a spectrum with the calculated HVLs approximately equal to those measured (equivalent spectrum) and then (b) to determine a filtration scheme (equivalent filter) that attenuates the equivalent spectrum in a similar fashion as the actual filtration attenuates the actual x-ray beam, as measured by the bowtie profile measurements. Using this method, two types of equivalent source models were generated: One using a spectrum based on both HVL 1 and HVL 2 measurements and its corresponding filtration scheme and the second consisting of a spectrum based only on the measured HVL 1 and its corresponding filtration scheme. Finally, a third type of source model was built based on the spectrum and filtration data provided by the scanner's manufacturer. MC simulations using each of these three source model types were evaluated by comparing the accuracy of multiple CT dose index (CTDI) simulations to measured CTDI values for 64-slice scanners from the four major MDCT manufacturers. Comprehensive evaluations were carried out for each scanner using each kVp and bowtie filter combination available. CTDI experiments were performed for both head (16 cm in diameter) and body (32 cm in diameter) CTDI phantoms using both central and peripheral measurement positions. Both equivalent source model types

Optical measurement of isolated canine lung filtration coefficients after alloxan infusion.

Science.gov (United States)

Klaesner, J W; Pou, N A; Parker, R E; Finney, C; Roselli, R J

1998-04-01

In this study, lung filtration coefficient (Kfc) was measured in eight isolated canine lung preparations by using three methods: standard gravimetric (Std), blood-corrected gravimetric (BC), and optical. The lungs were held in zone III conditions and were subjected to an average venous pressure increase of 8.79 +/- 0.93 (mean +/- SD) cmH2O. The permeability of the lungs was increased with an infusion of alloxan (75 mg/kg). The resulting Kfc values (in milliliters . min-1 . cmH2O-1 . 100 g dry lung weight-1) measured by using Std and BC gravimetric techniques before vs. after alloxan infusion were statistically different: Std, 0.527 +/- 0.290 vs. 1. 966 +/- 0.283; BC, 0.313 +/- 0.290 vs. 1.384 +/- 0.290. However, the optical technique did not show any statistical difference between pre- and postinjury with alloxan, 0.280 +/- 0.305 vs. 0.483 +/- 0. 297, respectively. The alloxan injury, quantified by using multiple-indicator techniques, showed an increase in permeability and a corresponding decrease in reflection coefficient for albumin (sigmaf). Because the optical method measures the product of Kfc and sigmaf, this study shows that albumin should not be used as an intravascular optical filtration marker when permeability is elevated. However, the optical technique, along with another means of measuring Kfc (such as BC), can be used to calculate the sigmaf of a tracer (in this study, sigmaf of 0.894 at baseline and 0.348 after injury). Another important finding of this study was that the ratio of baseline-to-injury Kfc values was not statistically different for Std and BC techniques, indicating that the percent contribution of slow blood-volume increases does not change because of injury.

Measured performance of filtration and ventilation systems for fine and ultrafine particles and ozone in an unoccupied modern California house

Energy Technology Data Exchange (ETDEWEB)

Singer, Brett C. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Delp, William W. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Black, Douglas R. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Walker, Iain S. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

2016-12-01

This study evaluated nine ventilation and filtration systems in an unoccupied 2006 house located 250m downwind of the I-80 freeway in Sacramento, California. Systems were evaluated for reducing indoor concentrations of outdoor particles in summer and fall/winter, ozone in summer, and particles from stir-fry cooking. Air exchange rate was measured continuously. Energy use was estimated for year-round operation in California. Exhaust ventilation without enhanced filtration produced indoor PM_2.5 that was 70% lower than outdoors. Supply ventilation with MERV13 filtration provided slightly less protection whereas supply MERV16 filtration reduced PM_2.55 by 97-98% relative to outdoors. Supply filtration systems used little energy but provided no benefits for indoor-generated particles. Systems with MERV13-16 filters in the recirculating heating and cooling unit (FAU) operating continuously or 20 min/h reduced PM_2.5 by 93-98%. Across all systems, removal percentages were higher for ultrafine particles and lower for black carbon, relative to PM_2.5. Indoor ozone was 3-4% of outdoors for all systems except an electronic air cleaner that produced ozone. Filtration via the FAU or portable filtration units lowered PM_2.5 by 25-75% when operated over the hour following cooking. The energy for year-round operation of FAU filtration with an efficient blower motor was estimated at 600 kWh/year.

Magnetic-seeding filtration

International Nuclear Information System (INIS)

Ying, T.Y.; Chin, C.J.; Lu, S.C.; Yiacoumi, S.

1997-10-01

Magnetic-seeding filtration consists of two steps: heterogeneous particle flocculation of magnetic and nonmagnetic particles in a stirred tank and high-gradient magnetic filtration (HGMF). The effects of various parameters affecting magnetic-seeding filtration (HGMF). The effects of various parameters affecting magnetic seeding filtration are theoretically and experimentally investigated. A trajectory model that includes hydrodynamic resistance, van der Waals, and electrostatic forces is developed to calculate the flocculation frequency in a turbulent-shear regime. Fractal dimension is introduced to simulate the open structure of aggregates. A magnetic-filtration model that consists of trajectory analysis, a particle build-up model, a breakthrough model, and a bivariate population-balance model is developed to predict the breakthrough curve of magnetic-seeding filtration. A good agreement between modeling results and experimental data is obtained. The results show that the model developed in this study can be used to predict the performance of magnetic-seeding filtration without using empirical coefficients or fitting parameters. 35 refs., 7 figs., 1 tab

Inherently safe reactors

International Nuclear Information System (INIS)

Maartensson, Anders

1992-01-01

A rethinking of nuclear reactor safety has created proposals for new designs based on inherent and passive safety principles. Diverging interpretations of these concepts can be found. This article reviews the key features of proposed advanced power reactors. An evaluation is made of the degree of inherent safety for four different designs: the AP-600, the PIUS, the MHTGR and the PRISM. The inherent hazards of today's most common reactor principles are used as reference for the evaluation. It is concluded that claims for the new designs being inherently, naturally or passively safe are not substantiated by experience. (author)

Measurement of water filtration in skeletal muscle in man by an osmotic transient method

DEFF Research Database (Denmark)

Palm, T; Nielsen, S L; Lassen, N A

1983-01-01

Water filtration in the human forearm was determined with a new method using a hyperoncotic transient of albumin solution infused into the brachial artery. Baseline dilution of labelled albumin in deep forearm vein plasma in excess of the contribution from arterial blood and from infusate...... was assumed to originate from extravascular water filtered into the blood by the transient. The filtration coefficient (Fc) was determined as the ratio between filtered water and increase in colloid osmotic pressure in the blood samples, and gives the filtrative water permeability in the exchange areas...... muscles, but it is of the same order of magnitude as the capillary filtration coefficient (CFC) determined plethysmographically for the entire forearm by the venous stasis technique....

Single- versus multiple-sample method to measure glomerular filtration rate.

Science.gov (United States)

Delanaye, Pierre; Flamant, Martin; Dubourg, Laurence; Vidal-Petiot, Emmanuelle; Lemoine, Sandrine; Cavalier, Etienne; Schaeffner, Elke; Ebert, Natalie; Pottel, Hans

2018-01-08

There are many different ways to measure glomerular filtration rate (GFR) using various exogenous filtration markers, each having their own strengths and limitations. However, not only the marker, but also the methodology may vary in many ways, including the use of urinary or plasma clearance, and, in the case of plasma clearance, the number of time points used to calculate the area under the concentration-time curve, ranging from only one (Jacobsson method) to eight (or more) blood samples. We collected the results obtained from 5106 plasma clearances (iohexol or 51Cr-ethylenediaminetetraacetic acid (EDTA)) using three to four time points, allowing GFR calculation using the slope-intercept method and the Bröchner-Mortensen correction. For each time point, the Jacobsson formula was applied to obtain the single-sample GFR. We used Bland-Altman plots to determine the accuracy of the Jacobsson method at each time point. The single-sample method showed within 10% concordances with the multiple-sample method of 66.4%, 83.6%, 91.4% and 96.0% at the time points 120, 180, 240 and ≥300 min, respectively. Concordance was poorer at lower GFR levels, and this trend is in parallel with increasing age. Results were similar in males and females. Some discordance was found in the obese subjects. Single-sample GFR is highly concordant with a multiple-sample strategy, except in the low GFR range (<30 mL/min). © The Author 2018. Published by Oxford University Press on behalf of ERA-EDTA. All rights reserved.

A Combined Approach to Measure Micropollutant Behaviour during Riverbank Filtration

Science.gov (United States)

van Driezum, Inge; Saracevic, Ernis; Derx, Julia; Kirschner, Alexander; Sommer, Regina; Farnleitner, Andreas; Blaschke, Alfred Paul

2016-04-01

Riverbank filtration (RBF) systems are widely used as natural treatment process. The advantages of RBF over surface water abstraction are the elimination of for example suspended solids, biodegradable compounds (like specific micropollutants), bacteria and viruses (Hiscock and Grischek, 2002). However, in contrast to its importance, remarkably less is known on the respective external (e.g. industrial or municipal sewage) and the internal (e.g. wildlife and agricultural influence) sources of contaminants, the environmental availability and fate of the various hazardous substances, and its potential transport during soil and aquifer passage. The goal of this study is to get an insight in the behaviour of various micropollutants and microbial indicators during riverbank filtration. Field measurements were combined with numerical modelling approaches. The study area comprises an alluvial backwater and floodplain area downstream of Vienna. The river is highly dynamic, with discharges ranging from 900 m3/s during low flow to 11000 m3/s during flood events. Samples were taken in several monitoring wells along a transect extending from the river towards a backwater river in the floodplain. Three of the piezometers were situated in the first 20 meters away from the river in order to obtain information about micropollutant behaviour close to the river. A total of 9 different micropollutants were analysed in grab samples taken under different river flow conditions (n=33). Following enrichment using SPE, analysis was performed using high performance liquid chromatography-tandem mass spectrometry. Faecal indicators (E. coli and enterococci) and bacterial spores were enumerated in sample volumes of 1 L each using cultivation based methods (ISO 16649-1, ISO 7899-2:2000 and ISO 6222). The analysis showed that some compounds, e.g. ibuprofen and diclofenac, were only found in the river. These compounds were already degraded in the first ten meters away from the river. Analysis of

Measurement of glomerular filtration rate in children using technetium-99m diethylenetriamine penta-acetic acid

International Nuclear Information System (INIS)

Aaronson, I.A.; Mann, M.D.

1985-01-01

During the past 5 years, we have measured the glomerular filtration rate (GFR) by the slope-clearance method using technetium-99m diethylenetriamine penta-acetic acid technetium-99m-DTPA in 130 infants and children. The results in 22 children have been compared with inulin clearance, and a very good correlation between the two methods of measurement of GFR was demonstrated (r = 0,9616; P less than 0,0001). This study provides further evidence that technetium-99m-DTPA is a satisfactory agent for the clinical measurement of GFR in children

GSPEL - Air Filtration Laboratory

Data.gov (United States)

Federal Laboratory Consortium — Evaluation capabilities for air filtration devicesThe Air Filtration Lab provides testing of air filtration devices to demonstrate and validate new or legacy system...

40 CFR 141.173 - Filtration.

Science.gov (United States)

2010-07-01

... PRIMARY DRINKING WATER REGULATIONS Enhanced Filtration and Disinfection-Systems Serving 10,000 or More People § 141.173 Filtration. A public water system subject to the requirements of this subpart that does... treatment, direct filtration, slow sand filtration, or diatomaceous earth filtration. A public water system...

Rotating Ceramic Water Filter Discs System for Water Filtration

Directory of Open Access Journals (Sweden)

Riyadh Z. Al Zubaidy

2017-04-01

Full Text Available This work aimed to design, construct and operate a new laboratory scale water filtration system. This system was used to examine the efficiency of two ceramic filter discs as a medium for water filtration. These filters were made from two different ceramic mixtures of local red clay, sawdust, and water. The filtration system was designed with two rotating interfered modules of these filters. Rotating these modules generates shear force between water and the surfaces of filter discs of the filtration modules that works to reduce thickness of layer of rejected materials on the filters surfaces. Each module consists of seven filtration units and each unit consists of two ceramic filter discs. The average measured hydraulic conductivity of the first module was 13.7mm/day and that for the second module was 50mm/day. Results showed that the water filtration system can be operated continuously with a constant flow rate and the filtration process was controlled by a skin thin layer of rejected materials. The ceramic water filters of both filtration modules have high removal efficiency of total suspended solids up to 100% and of turbidity up to 99.94%.

Dispersion and Filtration of Carbon Nanotubes (CNTs) and Measurement of Nanoparticle Agglomerates in Diesel Exhaust.

Science.gov (United States)

Wang, Jing; Pui, David Y H

2013-01-14

Carbon nanotubes (CNTs) tend to form bundles due to their geometry and van der Walls forces, which usually complicates studies of the CNT properties. Dispersion plays a significant role in CNT studies and we summarize dispersion techniques to generate airborne CNTs from suspensions or powders. We describe in detail our technique of CNT aerosolization with controlled degree of agglomeration using an electrospray system. The results of animal inhalation studies using the electrosprayed CNTs are presented. We have performed filtration experiments for CNTs through a screen filter. A numerical model has been established to simulate the CNT filtration experiments. Both the modeling and experimental results show that the CNT penetration is less than the penetration for a sphere with the same mobility diameter, which is mainly due to the larger interception length of the CNTs. There is a need for instruments capable of fast and online measurement of gas-borne nanoparticle agglomerates. We developed an instrument Universal NanoParticle Analyzer (UNPA) and the measurement results for diesel exhaust particulates are presented. The results presented here are pertinent to non-spherical aerosol particles, and illustrate the effects of particle morphology on aerosol behaviors.

Dynamic Heterogeneous Multiscale Filtration Model: Probing Micro- and Macroscopic Filtration Characteristics of Gasoline Particulate Filters.

Science.gov (United States)

Gong, Jian; Viswanathan, Sandeep; Rothamer, David A; Foster, David E; Rutland, Christopher J

2017-10-03

Motivated by high filtration efficiency (mass- and number-based) and low pressure drop requirements for gasoline particulate filters (GPFs), a previously developed heterogeneous multiscale filtration (HMF) model is extended to simulate dynamic filtration characteristics of GPFs. This dynamic HMF model is based on a probability density function (PDF) description of the pore size distribution and classical filtration theory. The microstructure of the porous substrate in a GPF is resolved and included in the model. Fundamental particulate filtration experiments were conducted using an exhaust filtration analysis (EFA) system for model validation. The particulate in the filtration experiments was sampled from a spark-ignition direct-injection (SIDI) gasoline engine. With the dynamic HMF model, evolution of the microscopic characteristics of the substrate (pore size distribution, porosity, permeability, and deposited particulate inside the porous substrate) during filtration can be probed. Also, predicted macroscopic filtration characteristics including particle number concentration and normalized pressure drop show good agreement with the experimental data. The resulting dynamic HMF model can be used to study the dynamic particulate filtration process in GPFs with distinct microstructures, serving as a powerful tool for GPF design and optimization.

Radioisotopic measurement of glomerular filtration rate in severe chronic renal failure

International Nuclear Information System (INIS)

LaFrance, N.D.; Drew, H.H.; Walser, M.

1988-01-01

In order to determine the best method for routine measurement of glomerular filtration rate (GFR) in severe renal failure, we compared simultaneously the urinary clearances of [/sup 99m/Tc] diethylenetriaminepentaacetic acid (DTPA) (UD), [ 125 I]iothalamate (UI), 24-hr creatinine clearance (UC) and plasma clearance of [/sup 99m/Tc]DTPA (PD), based on three plasma samples. In 60 studies in 22 patients with serum creatinine values of 2 to 8 mg/dl, UD and UI were almost identical: UD = 0.358 +/- 0.976 UI +/- 0.87 ml/min, r = 0.990. However, PD overestimated UD by a large and variable extent: PD = 11.3 +/- 0.843 UD +/- 5.5 ml/min, r = 0.694, and was inconsistent in sequential measurements in individual patients. UC also overestimated urinary isotope clearance: UC = 4.2 + 0.95 UI +/- 3.9 ml/min, r = 0.865. Sequential measurements of GFR in five patients with severe but stable renal failure (mean GFR 5.9 ml/min) showed an average standard deviation of only 0.83 ml/min. Thus both UD and UI appear to be reliable and precise measures of GFR in severe renal failure

Measuring situational awareness and resolving inherent high-level fusion obstacles

Science.gov (United States)

Sudit, Moises; Stotz, Adam; Holender, Michael; Tagliaferri, William; Canarelli, Kathie

2006-04-01

Information Fusion Engine for Real-time Decision Making (INFERD) is a tool that was developed to supplement current graph matching techniques in Information Fusion models. Based on sensory data and a priori models, INFERD dynamically generates, evolves, and evaluates hypothesis on the current state of the environment. The a priori models developed are hierarchical in nature lending them to a multi-level Information Fusion process whose primary output provides a situational awareness of the environment of interest in the context of the models running. In this paper we look at INFERD's multi-level fusion approach and provide insight on the inherent problems such as fragmentation in the approach and the research being undertaken to mitigate those deficiencies. Due to the large variance of data in disparate environments, the awareness of situations in those environments can be drastically different. To accommodate this, the INFERD framework provides support for plug-and-play fusion modules which can be developed specifically for domains of interest. However, because the models running in INFERD are graph based, some default measurements can be provided and will be discussed in the paper. Among these are a Depth measurement to determine how much danger is presented by the action taking place, a Breadth measurement to gain information regarding the scale of an attack that is currently happening, and finally a Reliability measure to tell the user the credibility of a particular hypothesis. All of these results will be demonstrated in the Cyber domain where recent research has shown to be an area that is welldefined and bounded, so that new models and algorithms can be developed and evaluated.

Filtration characteristics in membrane bioreactors

NARCIS (Netherlands)

Evenblij, H.

2006-01-01

Causes of and remedies for membrane fouling in Membrane Bioreactors for wastewater treatment are only poorly understood and described in scientific literature. A Filtration Characterisation Installation and a measurement protocol were developed with the aim of a) unequivocally determination and

Measurement-Based Evaluation of Installed Filtration System Performance in Single-Family Homes

Energy Technology Data Exchange (ETDEWEB)

Chan, Wanyu Rengie; Singer, Brett C.

2014-04-03

This guide discusses important study design issues to consider when conducting an on-site evaluation of filtration system performance. The two most important dichotomies to consider in developing a study protocol are (1) whether systems are being evaluated in occupied or unoccupied homes and (2) whether different systems are being compared in the same homes or if the comparison is between systems installed in different homes. This document provides perspective and recommendations about a suite of implementation issues including the choice of particle measurement devices, selection of sampling locations, ways to control and/or monitor factors and processes that can impact particle concentrations, and data analysis approaches.

Quick and Easy Measurements of the Inherent Optical Property of Water by Laser

International Nuclear Information System (INIS)

Izadi, Dina; Hajiesmaeilbaigi, Fereshteh

2009-01-01

To generate realistic images of natural waters, one must consider in some detail the interaction of light with the water body. The reflectance and attenuation coefficient of the second harmonic of Nd:YAG laser light through distilled water and a sample of water from the Oman Sea were measured in a solid-state laser laboratory to estimate inherent optical properties of natural waters. These measurements determined the bottom conditions and the impurities of the water. The water's reflectivity varied depending on the angle of incidence, height of the laser from water surface, wavelength of laser light, radiant intensities, and depth of water. In these experiments laser light propagated through the water nonlinearly, and different reflectance showed different bottom slopes. The differences among various water samples were obtained taking into account the exponential equation in attenuation coefficient versus depth graphs.

Optical measurement of isolated canine lung filtration coefficients at normal hematocrits.

Science.gov (United States)

Klaesner, J W; Pou, N A; Parker, R E; Finney, C; Roselli, R J

1997-12-01

In this study, lung filtration coefficient (Kfc) values were measured in eight isolated canine lung preparations at normal hematocrit values using three methods: gravimetric, blood-corrected gravimetric, and optical. The lungs were kept in zone 3 conditions and subjected to an average venous pressure increase of 10.24 +/- 0.27 (SE) cmH2O. The resulting Kfc (ml . min-1 . cmH2O-1 . 100 g dry lung wt-1) measured with the gravimetric technique was 0.420 +/- 0.017, which was statistically different from the Kfc measured by the blood-corrected gravimetric method (0.273 +/- 0.018) or the product of the reflection coefficient (sigmaf) and Kfc measured optically (0. 272 +/- 0.018). The optical method involved the use of a Cellco filter cartridge to separate red blood cells from plasma, which allowed measurement of the concentration of the tracer in plasma at normal hematocrits (34 +/- 1.5). The permeability-surface area product was measured using radioactive multiple indicator-dilution methods before, during, and after venous pressure elevations. Results showed that the surface area of the lung did not change significantly during the measurement of Kfc. These studies suggest that sigmafKfc can be measured optically at normal hematocrits, that this measurement is not influenced by blood volume changes that occur during the measurement, and that the optical sigmafKfc agrees with the Kfc obtained via the blood-corrected gravimetric method.

Crossflow Filtration: EM-31, WP-2.3.6

International Nuclear Information System (INIS)

Duignan, M.; Nash, C.; Poirier, M.

2011-01-01

tests to evaluate methods to improve filter performance. With the proper use of filter flow conditions and filter enhancers, filter flow rates can be increased over rates currently realized today. Experiments that use non-radioactive simulants for actual waste always carry the inherent risk of not eliciting prototypic results; however, they will assist in focusing the scope needed to minimize radioactive testing and thus maximize safety. To that end this investigation has determined: (1) Waste simulant SB6 was found to be more challenging to filtration than a SRS Tank 8F simulant; (2) Higher solids concentration presents a greater challenge to filtration; (3) Filter cake is something that should be properly developed in initial filter operation; (4) Backpulsing is not necessary to maintain a good filter flux with salt wastes; (5) Scouring a filter without cleaning will lead to improved filter performance; (6) The presence of a filter cake can improve the solids separation by an order of magnitude as determined by turbidity; (7) A well developed cake with periodic scouring may allow a good filter flux to be maintained for long periods of time; and (8) Filtrate flux decline is reversible when the concentration of the filtering slurry drops and the filter is scoured.

CROSSFLOW FILTRATION: EM-31, WP-2.3.6

Energy Technology Data Exchange (ETDEWEB)

Duignan, M.; Nash, C.; Poirier, M.

2011-02-01

tests to evaluate methods to improve filter performance. With the proper use of filter flow conditions and filter enhancers, filter flow rates can be increased over rates currently realized today. Experiments that use non-radioactive simulants for actual waste always carry the inherent risk of not eliciting prototypic results; however, they will assist in focusing the scope needed to minimize radioactive testing and thus maximize safety. To that end this investigation has determined: (1) Waste simulant SB6 was found to be more challenging to filtration than a SRS Tank 8F simulant; (2) Higher solids concentration presents a greater challenge to filtration; (3) Filter cake is something that should be properly developed in initial filter operation; (4) Backpulsing is not necessary to maintain a good filter flux with salt wastes; (5) Scouring a filter without cleaning will lead to improved filter performance; (6) The presence of a filter cake can improve the solids separation by an order of magnitude as determined by turbidity; (7) A well developed cake with periodic scouring may allow a good filter flux to be maintained for long periods of time; and (8) Filtrate flux decline is reversible when the concentration of the filtering slurry drops and the filter is scoured.

Inherent/passive safety for fusion

International Nuclear Information System (INIS)

Piet, S.J.

1986-06-01

The concept of inherent or passive passive safety for fusion energy is explored, defined, and partially quantified. Four levels of safety assurance are defined, which range from true inherent safety to passive safety to protection via active engineered safeguard systems. Fusion has the clear potential for achieving inherent or passive safety, which should be an objective of fusion research and design. Proper material choice might lead to both inherent safety and high mass power density, improving both safety and economics. When inherent safety is accomplished, fusion will be well on the way to achieving its ultimate potential and to be truly different and superior

Filtration and compression of organic materials

DEFF Research Database (Denmark)

Christensen, Morten Lykkegaard; Keiding, Kristian

is to use more simple systems. Dextran-MnO2 particles and polystyrene particles with a water-swollen polyacrylic acid shell have therefore been synthesised. These particles have been filtered and used to study the non-linear filtration behaviour. The compressibility of the formed cake has been investigated......The conventional filtration theory has been based on filtrations of incompressible particles such as anatase, kaolin and clay. The filtration models have later been used for organic slurries but can often not explain the observed experimental data. At constant pressure, the filtrate volume does...... and the discrepancy between the filtration theory and the observed filtration behaviour explained as a time-dependent collapse of the formed cake (creep). Thus, the creep phenomenon has been adopted in the conventional filtration models and it will be shown that the model can be used to simulate filtration data...

Fusion Kalman filtration with k-step delay sharing pattern

Directory of Open Access Journals (Sweden)

Duda Zdzisław

2015-09-01

Full Text Available A fusion hierarchical state filtration with k−step delay sharing pattern for a multisensor system is considered. A global state estimate depends on local state estimates determined by local nodes using local information. Local available information consists of local measurements and k−step delay global information - global estimate sent from a central node. Local estimates are transmitted to the central node to be fused. The synthesis of local and global filters is presented. It is shown that a fusion filtration with k−step delay sharing pattern is equivalent to the optimal centralized classical Kalman filtration when local measurements are transmitted to the center node and used to determine a global state estimate. It is proved that the k−step delay sharing pattern can reduce covariances of local state errors.

Filtration in Porous Media

DEFF Research Database (Denmark)

Yuan, Hao; Shapiro, Alexander

There is a considerable and ongoing effort aimed at understanding the transport and the deposition of suspended particles in porous media, especially non-Fickian transport and non-exponential deposition of particles. In this work, the influential parameters in filtration models are studied...... to understand their effects on the non-Fickian transport and the non-exponential deposition. The filtration models are validated by the comparisons between the modelling results and the experimental data.The elliptic equation with distributed filtration coefficients may be applied to model non-Fickian transport...... and hyperexponential deposition. The filtration model accounting for the migration of surface associated particles may be applied for non-monotonic deposition....

Monitoring renal function in children with Fabry disease: comparisons of measured and creatinine-based estimated glomerular filtration rate

NARCIS (Netherlands)

Tøndel, Camilla; Ramaswami, Uma; Aakre, Kristin Moberg; Wijburg, Frits; Bouwman, Machtelt; Svarstad, Einar

2010-01-01

Studies on renal function in children with Fabry disease have mainly been done using estimated creatinine-based glomerular filtration rate (GFR). The aim of this study was to compare estimated creatinine-based GFR (eGFR) with measured GFR (mGFR) in children with Fabry disease and normal renal

Wind Turbine Gearbox Oil Filtration and Condition Monitoring

Energy Technology Data Exchange (ETDEWEB)

Sheng, Shuangwen

2015-10-25

This is an invited presentation for a pre-conference workshop, titled advances and opportunities in lubrication: wind turbine, at the 2015 Society of Tribologists and Lubrication Engineers (STLE) Tribology Frontiers Conference held in Denver, CO. It gives a brief overview of wind turbine gearbox oil filtration and condition monitoring by highlighting typical industry practices and challenges. The presentation starts with an introduction by covering recent growth of global wind industry, reliability challenges, benefits of oil filtration and condition monitoring, and financial incentives to conduct wind operation and maintenance research, which includes gearbox oil filtration and condition monitoring work presented herein. Then, the presentation moves on to oil filtration by stressing the benefits of filtration, discussing typical main- and offline-loop practices, highlighting important factors considered when specifying a filtration system, and illustrating real-world application challenges through a cold-start example. In the next section on oil condition monitoring, a discussion on oil sample analysis, oil debris monitoring, oil cleanliness measurements and filter analysis is given based on testing results mostly obtained by and at NREL, and by pointing out a few challenges with oil sample analysis. The presentation concludes with a brief touch on future research and development (R and D) opportunities. It is hoping that the information presented can inform the STLE community to start or redirect their R and D work to help the wind industry advance.

Filtration Efficiency of Functionalized Ceramic Foam Filters for Aluminum Melt Filtration

Science.gov (United States)

Voigt, Claudia; Jäckel, Eva; Taina, Fabio; Zienert, Tilo; Salomon, Anton; Wolf, Gotthard; Aneziris, Christos G.; Le Brun, Pierre

2017-02-01

The influence of filter surface chemistry on the filtration efficiency of cast aluminum alloys was evaluated for four different filter coating compositions (Al2O3—alumina, MgAl2O4—spinel, 3Al2O3·2SiO2—mullite, and TiO2—rutile). The tests were conducted on a laboratory scale with a filtration pilot plant, which facilitates long-term filtration tests (40 to 76 minutes). This test set-up allows the simultaneous use of two LiMCAs (before and after the filter) for the determination of the efficiency of inclusion removal. The four tested filter surface chemistries exhibited good thermal stability and mechanical robustness after 750 kg of molten aluminum had been cast. All four filter types exhibited a mean filtration efficiency of at least 80 pct. However, differences were also observed. The highest filtration efficiencies were obtained with alumina- and spinel-coated filter surfaces (>90 pct), and the complete removal of the largest inclusions (>90 µm) was observed. The efficiency was slightly lower with mullite- and rutile-coated filter surfaces, in particular for large inclusions. These observations are discussed in relation to the properties of the filters, in particular in terms of, for example, the surface roughness.

Filtration of polydispersed colloids

International Nuclear Information System (INIS)

Nuttall, H.E.

1988-01-01

In this study, the dynamic microscopic form of the population balance model is applied to the problem of polydispersed particle capture in one spatial diffusion. This mathematical modeling approach can be applied to the difficult and potentially important problem of particulate (radiocolloid) transport in the groundwater surrounding a nuclear waste disposal site. To demonstrate the population balance methodology, the equations were developed and used to investigate transport and capture of polydispersed colloids in packed columns. Modeling simulations were compared to experimental column data. The multidimensional form of the population balance equation was used to analyze the transport and capture of polydispersed colloids. A numerical model was developed to describe transport of polydispersed colloids through a one-dimensional porous region. The effects of various size distributions were investigated in terms of capture efficiency. For simulating the column data, it was found by trial and error that as part of the population balance model a linear size dependent filtration function gave a good fit to the measured colloid concentration profile. The effects of constant versus size dependent filtration coefficients were compared and the differences illustrated by the calculated colloid profile within the column. Also observed from the model calculations was the dramatically changing liquid-phase colloid-size distribution which was plotted as a function of position down the column. This modeling approach was excellent for describing and understanding microscopic filtration in porous media

Glomerular filtration in kidney recipients measured by plasma clearance of 169Yb-DTPA

International Nuclear Information System (INIS)

Stribrna, J.; Oppelt, A.; Jirickova, E.; Janata, V.; Kocandrle, V.; Sup, I.; Woller, P.; Franke, W.G.

1986-01-01

Values of 169 Yb-DTPA clearance (C DTPA ) calculated after a single injection were compared in 26 recipients of kidneys with renal clearance of inulin (C in ), polyfructosan S (C pf ) and creatinine (C cr ). In 21 patients the examinations were made simultaneously, in 5 patients C DTPA was measured within a short interval after the examination of renal clearance. The mean C DTPA values did not significantly differ from C cr but were significantly higher (p in and C pf (by 33% on average). Investigation of changes in C DTPA as compared with C in and C pf showed no significant difference in glomerular filtration (GF). This was measured using inulin and polyfructosan. The results showed that the differing molecular weight of inulin and polyfructosan S had no detectable effect on the GF of kidney recipients. The plasma clearance of 169 Yb-DTPA similarly to C cr overestimates the GF measured by inulin and polyfructosan clearance. (author)

Comparison of Measured Residual Stress in an Extra Thick Multi-pass Weld Using Neutron Diffraction Method and Inherent Strain Method

International Nuclear Information System (INIS)

Park, JeongUng; An, GyuBaek; Woo, Wan Chuck

2015-01-01

With the increase of large-scale containership, a large amount of high-strength steels with extra thick plates is being extensively used. The welding stress existing in the extra thick welded plates has a significant effect on the integrity of the component in terms of brittle fracture and fatigue behavior. It has been reported that welding residual stress distribution in an extra thick plate can affect the propagation path of the crack. Therefore, it is important to measure the distribution of welding residual stresses for the reliable design of the welded structures. So far various researches have been carried out for the determination of residual stresses on the surface of steels. In this paper, the total residual stresses in the 70 mm thick multipass FACW butt joint were measured by integrating initial stress into ISM. Concretely, two methods named as initial stress integrated ISM and initial inherent strain integrated ISM were employed to determine the total residual stresses. Furthermore, the distributions of residual stresses were compared with the results of the Neutron Diffraction Method(NDM). In order to measure the three dimensional residual stresses in the welded joint with initial stresses existing before welding, initial stress integrated ISM and initial inherent strain integrated ISM were developed. The residual stresses in 70 mm-thick butt joint by flux cored arc welding were carried out with a good accuracy using the two developed methods. The residual stresses in welded joint using both initial stress integrated ISM and initial inherent strain integrated ISM agreed well with the results measured by Neutron Diffraction Method. This suggests that the integrated ISM is a reliable method for residual stress measurement if initial stress existed

PROBLEMS OF NONSTATIONARY FILTRATION

Directory of Open Access Journals (Sweden)

Vsevolod A. Shabanov

2018-03-01

Full Text Available he article deals with the classical hydrodynamic theory of filtration. Discusses models of soil, fluid and nature of fluid flow that formed the basis for the creation of the classic filtration theory. Also discusses the assumptions made for the linearization of the equations. Evaluated the scope of the classical filtration theory. Proposed a new model of filtration through a porous medium, based on the application of the laws of theoretical mechanics. It is based on the classical model of soil: the soil is composed of capillaries with ..parallel axes, in which the liquid moves. For tasks of infiltration equations of motion. Considered special cases of unsteady motion of a finite volume of liquid. Numerical example a machine experiment.

Glomerular filtration rate measured by 51Cr-EDTA clearance: evaluation of captopril-induced changes in hypertensive patients with and without renal artery stenosis

International Nuclear Information System (INIS)

Chaves, Anna Alice Rolim; Buchpiguel, Carlos Alberto; Praxedes, Jose Nery; Bortolotto, Luiz Aparecido; Sapienza, Marcelo Tatit

2010-01-01

Introduction: renal artery stenosis can lead to renovascular hypertension; however, the detection of stenosis alone does not guarantee the presence of renovascular hypertension. Renovascular hypertension depends on activation of the renin-angiotensin system, which can be detected by functional tests such as captopril renal scintigraphy. A method that allows direct measurement of the baseline and post-captopril glomerular filtration rate using chromium-51 labeled ethylenediamine tetraacetic acid ( 51 Cr-EDTA) could add valuable information to the investigation of hypertensive patients with renal artery stenosis. The purposes of this study were to create a protocol to measure the baseline and post-captopril glomerular filtration rate using 51 Cr-EDTA, and to verify whether changes in the glomerular filtration rate permit differentiation between hypertensive patients with and without renal artery stenosis. Methods: this prospective study included 41 consecutive patients with poorly controlled severe hypertension. All patients had undergone a radiological investigation of renal artery stenosis within the month prior to their inclusion. The patients were divided into two groups: patients with (n=21) and without renal artery stenosis, (n=20). In vitro glomerular filtration rate analysis ( 51 Cr-EDTA) and 99m Tc-DMSA scintigraphy were performed before and after captopril administration in all patients. Results: the mean baseline glomerular filtration rate was 48.6±21.8 ml/kg/1.73 m 2 in the group with renal artery stenosis, which was significantly lower than the GFR of 65.1±28.7 ml/kg/1.73m 2 in the group without renal artery stenosis (p=0.04). Captopril induced a significant reduction of the glomerular filtration rate in the group with renal artery stenosis (to 32.6±14.8 ml/kg/1.73m 2 , p=0.001) and an insignificant change in the group without RAS (to 62.2±23.6 ml/kg/1.73m 2 , p=0.68). Scintigraphy with technetium-99m dimercapto-succinic acid (DMSA) did not show

Water quality and treatment of river bank filtrate

Directory of Open Access Journals (Sweden)

W. W. J. M. de Vet

2010-06-01

Full Text Available In drinking water production, river bank filtration has the advantages of dampening peak concentrations of many dissolved components, substantially removing many micropollutants and removing, virtually completely, the pathogens and suspended solids. The production aquifer is not only fed by the river bank infiltrate but also by water percolating through covering layers. In the polder areas, these top layers consist of peat and deposits from river sediments and sea intrusions.

This paper discusses the origin and fate of macro components in river bank filtrate, based on extensive full-scale measurements in well fields and treatment systems of the Drinking Water Company Oasen in the Netherlands. First, it clarifies and illustrates redox reactions and the mixing of river bank filtrate and PW as the dominant processes determining the raw water quality for drinking water production. Next, full-scale results are elaborated on to evaluate trickling filtration as an efficient and proven one-step process to remove methane, iron, ammonium and manganese. The interaction of methane and manganese removal with nitrification in these systems is further analyzed. Methane is mostly stripped during trickling filtration and its removal hardly interferes with nitrification. Under specific conditions, microbial manganese removal may play a dominant role.

The role of passive and inherent safety properties in Siemens/KWU nuclear power plants

International Nuclear Information System (INIS)

Gremm, O.

1990-01-01

In Siemens/KWU Nuclear Power Plants the applied safety concept consist of a well balanced combination of active, passive use well is inherent safety measures. In principle it is not possible to realise a safety concept exclusively with inherent and/or passive safety properties. The respective measures and arguments will be explained in detail in the presentation. In addition the Siemens/KWU safety concept with examples of the role of inherent and passive safety measures will be illustrated. (author). 9 refs, 9 figs

Measured glomerular filtration rate does not improve prediction of mortality by cystatin C and creatinine.

Science.gov (United States)

Sundin, Per-Ola; Sjöström, Per; Jones, Ian; Olsson, Lovisa A; Udumyan, Ruzan; Grubb, Anders; Lindström, Veronica; Montgomery, Scott

2017-04-01

Cystatin C may add explanatory power for associations with mortality in combination with other filtration markers, possibly indicating pathways other than glomerular filtration rate (GFR). However, this has not been firmly established since interpretation of associations independent of measured GFR (mGFR) is limited by potential multicollinearity between markers of GFR. The primary aim of this study was to assess associations between cystatin C and mortality, independent of mGFR. A secondary aim was to evaluate the utility of combining cystatin C and creatinine to predict mortality risk. Cox regression was used to assess the associations of cystatin C and creatinine with mortality in 1157 individuals referred for assessment of plasma clearance of iohexol. Since cystatin C and creatinine are inversely related to mGFR, cystatin C - 1 and creatinine - 1 were used. After adjustment for mGFR, lower cystatin C - 1 (higher cystatin C concentration) and higher creatinine - 1 (lower creatinine concentration) were independently associated with increased mortality. When nested models were compared, avoiding the potential influence of multicollinearity, the independence of the associations was supported. Among models combining the markers of GFR, adjusted for demographic factors and comorbidity, cystatin C - 1 and creatinine - 1 combined explained the largest proportion of variance in associations with mortality risk ( R 2  = 0.61). Addition of mGFR did not improve the model. Our results suggest that both creatinine and cystatin C have independent associations with mortality not explained entirely by mGFR and that mGFR does not offer a more precise mortality risk assessment than these endogenous filtration markers combined. © The Author 2017. Published by Oxford University Press on behalf of ERA-EDTA. All rights reserved.

Inherently safe light water reactors

International Nuclear Information System (INIS)

Ise, Takeharu

1987-01-01

Today's large nuclear power reactors of world-wise use have been designed based on the philosophy. It seems that recent less electricity demand rates, higher capital cost and the TMI accident let us acknowledge relative small and simplified nuclear plants with safer features, and that Chernobyl accident in 1983 underlines the needs of intrinsic and passive safety characteristics. In such background, several inherently safe reactor concepts have been presented abroad and domestically. First describing 'Can inherently safe reactors be designed,' then I introduce representative reactor concepts of inherently safe LWRs advocated abroad so far. All of these innovative reactors employ intrinsic and passive features in their design, as follows: (1) PIUS, an acronym for Process Inherent Ultimate Safety, or an integral PWR with passive heat sink and passive shutdown mechanism, advocated by ASEA-ATOM of Sweden. (2) MAP(Minimum Attention Plant), or a self-pressurized, natural circulation integral PWR, promoted by CE Inc. of the U.S. (3) TPS(TRIGA Power System), or a compact PWR with passive heat sink and inherent fuel characteristics of large prompt temperature coefficient, prompted by GA Technologies Inc. of the U.S. (4) PIUS-BWR, or an inherently safe BWR employing passively actuated fluid valves, in competition with PIUS, prompted by ORNL of the U.S. Then, I will describe the domestic trends in Japan and the innovative inherently safe LWRs presented domestically so far. (author)

Comparison of inulin, iothalamate, and /sup 99m/Tc-DTPA for measurement of glomerular filtration rate

International Nuclear Information System (INIS)

Barbour, G.L.; Crumb, C.K.; Boyd, C.M.; Reeves, R.D.; Rastogi, S.P.; Patterson, R.M.

1976-01-01

Clearances of inulin, 125 I-iothalamate, and /sup 99m/Tc-Sn-DTPA were measured simultaneously in five mongrel dogs exhibiting a wide range of glomerular filtration rates (GFR). Standard constant-infusion inulin clearance was compared to radionuclide clearances after subcutaneous injection of the emitters mixed with aqueous epinephrine. All three substances were found to have virtually identical clearances. The accuracy, accessibility, low cost, low radiation hazard, and short half-life of /sup 99m/Tc-Sn-DTPA make it an excellent substance for measuring GFR. The subcutaneous technique offers an accuracy comparable to the more difficult constant-infusion method

Determination of the filtration velocities and mean velocity in ground waters using radiotracers

International Nuclear Information System (INIS)

Duran P, Oscar; Diaz V, Francisco; Heresi M, Nelida

1994-01-01

An experimental method to determine filtration, or, Darcy velocity and mean velocity in underground waters using radiotracers, is described. After selecting the most appropriate tracers, from 6 chemical compounds, to measure water velocity, a method to measure filtration velocity was developed. By fully labelling the water column with 2 radioisotopes, Br and tritium, almost identical values were obtained for the aquifer filtration velocity in the sounding S1. This value was 0.04 m/d. Field porosity was calculated at 11% and mean velocity at 0.37 m.d. With the filtration velocity value and knowing the hydraulic variation between the soundings S1 and S2 placed at 10 meters, field permeability was estimated at 2.4 x 10 m/s. (author)

Inherent Reward and Risk (Part I): Towards a Universal Paradigm for Investment Analysis

OpenAIRE

Liang Zou

2000-01-01

In this paper, a new paradigm is developed for analyzinginvestment strategies and pricing financial assets. This paradigmassumes that any investment strategy has its own “inherent reward”and “inherent risk” that can be judged with common sense. Ijustify axiomatically the existence and uniqueness (ratio scale)of inherent reward (U) and inherent risk (D) that could beregarded as universal measures of reward and risk for any giveninvestment strategy. Incorporating the notion of “inherentefficien...

Estimating Travel Time in Bank Filtration Systems from a Numerical Model Based on DTS Measurements.

Science.gov (United States)

des Tombe, Bas F; Bakker, Mark; Schaars, Frans; van der Made, Kees-Jan

2018-03-01

An approach is presented to determine the seasonal variations in travel time in a bank filtration system using a passive heat tracer test. The temperature in the aquifer varies seasonally because of temperature variations of the infiltrating surface water and at the soil surface. Temperature was measured with distributed temperature sensing along fiber optic cables that were inserted vertically into the aquifer with direct push equipment. The approach was applied to a bank filtration system consisting of a sequence of alternating, elongated recharge basins and rows of recovery wells. A SEAWAT model was developed to simulate coupled flow and heat transport. The model of a two-dimensional vertical cross section is able to simulate the temperature of the water at the well and the measured vertical temperature profiles reasonably well. MODPATH was used to compute flowpaths and the travel time distribution. At the study site, temporal variation of the pumping discharge was the dominant factor influencing the travel time distribution. For an equivalent system with a constant pumping rate, variations in the travel time distribution are caused by variations in the temperature-dependent viscosity. As a result, travel times increase in the winter, when a larger fraction of the water travels through the warmer, lower part of the aquifer, and decrease in the summer, when the upper part of the aquifer is warmer. © 2017 The Authors. Groundwater published by Wiley Periodicals, Inc. on behalf of National Ground Water Association.

Characterization of a test device for determination of the half value layer and of filtration with quality equity of materials in accordance with standard ABNT NBR IEC 60601-1-3

International Nuclear Information System (INIS)

Viana, Vlamir

2012-01-01

The motivation of this work was the development and validation of a device to perform the tests established by ABNT NBR IEC 60601-1-3 versions published in 2001 and 2011. The purpose of the tests is to determine the half-value layer – HVL and filtration with equivalent filtration quality in mmAl, materials that intercept the X-ray beam from their emission to the X-ray image receiving device. This filtration includes all the materials present in radiation source assembly, formed by the x-ray tube housing with x-ray tube inserted, the collimator (inherent filtration) and by materials present in the patients support, as Table and wall bucky, both incorporate image receiving device which is also evaluated. In the development was taken in consideration the routine of tests execution routine, in order to reduce the operator interaction with the system and in order to reduce the human factor in the execution, reflecting directly on the measurement uncertainty, in the runtime reduction of the runtime and radiation safety. The device was validated with respect to: a) Effect of positioning and distribution of the filters in the filter changer device; b) Influence of purity of the aluminum filter used in the device, and c) Comparison tests carried out with the testing device with respect to the tests carried out with a reference X-ray generator. (author)

Filtrations of free groups as intersections

OpenAIRE

Efrat, Ido

2013-01-01

For several natural filtrations of a free group S we express the n-th term of the filtration as the intersection of all kernels of homomorphisms from S to certain groups of upper-triangular unipotent matrices. This generalizes a classical result of Grun for the lower central filtration. In particular, we do this for the n-th term in the lower p-central filtration of S.

Glomerular filtration rate measured by {sup 51}Cr-EDTA clearance: evaluation of captopril-induced changes in hypertensive patients with and without renal artery stenosis

Energy Technology Data Exchange (ETDEWEB)

Chaves, Anna Alice Rolim; Buchpiguel, Carlos Alberto; Praxedes, Jose Nery; Bortolotto, Luiz Aparecido; Sapienza, Marcelo Tatit, E-mail: annaalice100@yahoo.com.b [Universidade de Sao Paulo (USP), SP (Brazil). Faculdade de Medicina. Dept. de Neurologia

2010-07-01

Introduction: renal artery stenosis can lead to renovascular hypertension; however, the detection of stenosis alone does not guarantee the presence of renovascular hypertension. Renovascular hypertension depends on activation of the renin-angiotensin system, which can be detected by functional tests such as captopril renal scintigraphy. A method that allows direct measurement of the baseline and post-captopril glomerular filtration rate using chromium-51 labeled ethylenediamine tetraacetic acid ({sup 51}Cr-EDTA) could add valuable information to the investigation of hypertensive patients with renal artery stenosis. The purposes of this study were to create a protocol to measure the baseline and post-captopril glomerular filtration rate using {sup 51}Cr-EDTA, and to verify whether changes in the glomerular filtration rate permit differentiation between hypertensive patients with and without renal artery stenosis. Methods: this prospective study included 41 consecutive patients with poorly controlled severe hypertension. All patients had undergone a radiological investigation of renal artery stenosis within the month prior to their inclusion. The patients were divided into two groups: patients with (n=21) and without renal artery stenosis, (n=20). In vitro glomerular filtration rate analysis ({sup 51}Cr-EDTA) and {sup 99m}Tc-DMSA scintigraphy were performed before and after captopril administration in all patients. Results: the mean baseline glomerular filtration rate was 48.6+-21.8 ml/kg/1.73 m{sup 2} in the group with renal artery stenosis, which was significantly lower than the GFR of 65.1+-28.7 ml/kg/1.73m{sup 2} in the group without renal artery stenosis (p=0.04). Captopril induced a significant reduction of the glomerular filtration rate in the group with renal artery stenosis (to 32.6+-14.8 ml/kg/1.73m{sup 2}, p=0.001) and an insignificant change in the group without RAS (to 62.2+-23.6 ml/kg/1.73m{sup 2}, p=0.68). Scintigraphy with technetium-99m dimercapto

Optimization of suspensions filtration with compressible cake

Directory of Open Access Journals (Sweden)

Janacova Dagmar

2016-01-01

Full Text Available In this paper there is described filtering process for separating reaction mixture after enzymatic hydrolysis to process the chromium tanning waste. Filtration of this mixture is very complicated because it is case of mixture filtration with compressible cake. Successful process strongly depends on mathematical describing of filtration, calculating optimal values of pressure difference, specific resistant of filtration cake and temperature maintenance which is connected with viscosity change. The mathematic model of filtration with compressible cake we verified in laboratory conditions on special filtration device developed on our department.

Water Filtration Products

Science.gov (United States)

1986-01-01

American Water Corporation manufactures water filtration products which incorporate technology originally developed for manned space operations. The formula involves granular activated charcoal and other ingredients, and removes substances by catalytic reactions, mechanical filtration, and absorption. Details are proprietary. A NASA literature search contributed to development of the compound. The technology is being extended to a deodorizing compound called Biofresh which traps gas and moisture inside the unit. Further applications are anticipated.

DQE of wireless digital detectors: Comparative performance with differing filtration schemes

International Nuclear Information System (INIS)

Samei, Ehsan; Murphy, Simon; Christianson, Olav

2013-01-01

Purpose: Wireless flat panel detectors are gaining increased usage in portable medical imaging. Two such detectors were evaluated and compared with a conventional flat-panel detector using the formalism of the International Electrotechnical Commission (IEC 62220-1) for measuring modulation transfer function (MTF), normalized noise power spectrum (NNPS), and detective quantum efficiency (DQE) using two different filtration schemes.Methods: Raw images were acquired for three image receptors (DRX-1C and DRX-1, Carestream Health; Inc., Pixium 4600, Trixell) using a radiographic system with a well-characterized output (Philips Super80 CP, Philips Healthcare). Free in-air exposures were measured using a calibrated radiation meter (Unfors Mult-O-Meter Type 407, Unfors Instruments AB). Additional aluminum filtration and a new alternative combined copper-aluminum filtration were used to conform the x ray output to IEC-specified beam quality definitions RQA5 and RQA9. Using the IEC 62220-1 formalism, each detector was evaluated at X N /2, X N , and 2X N , where the normal exposure level to the detector surface (X N ) was set to 8.73 μGy (1.0 mR). The prescribed edge test device was used to evaluate the MTF, while the NNPS was measured using uniform images. The DQE was then calculated from the MTF and NNPS and compared across detectors, exposures, and filtration schemes.Results: The three DR systems had largely comparable MTFs with DRX-1 demonstrating lower values above 1.0 cycles/mm. At each exposure, DRX-1C and Pixium detectors demonstrated better noise performance than that of DRX-1. Zero-frequency DQEs for DRX-1C, Pixium, and DRX-1 detectors were approximately 74%, 63%, and 38% for RQA5 and 50%, 42%, and 28% for RQA9, respectively.Conclusions: DRX-1C detector exhibited superior DQE performance compared to Pixium and DRX-1. In terms of filtration, the alternative filtration was found to provide comparable performance in terms of rank ordering of different detectors with

Complexant Identification in Hanford Waste Simulant Sr/TRU Filtrate

International Nuclear Information System (INIS)

Bannochie, C.J.

2003-01-01

This project was designed to characterize the available multidentate ligand species and metal ion complexes of iron, strontium and manganese formed with the parent chelators, complexing agents and their fragment products. Complex identification was applied to AN-102 and AN-107 filtrate simulants for Hanford waste after an oxidation reaction with sodium permanganate to create a freshly precipitated manganese dioxide solid for adsorption of transuranic elements. Separation efficiency of different ligands was investigated based on the exchange capability of different ion exchange and ion exclusion analytical columns including Dionex IonPac AS-5A, AS-10, AS-11 and AS-6. The elution programs developed with different mobile phase concentrations were based on the change in the effective charge of the anionic species and therefore the retention on the stationary phase. In the present work, qualitative and quantitative assessments of multidentate ligands were investigated. Identification methods for the metal ion complexes responsible for solubilizing Fe, Mn and Sr were applied to aged and fresh simulant waste filtrates. Although concentration measurements of both fresh and 3-week aged filtrates showed that the degradation process occurs mainly due to the harsh chemical environment, it was found that the concentration of iron and manganese did not increase, within the error of the analytical measurements, after three weeks when compared with fresh filtrate

Health Benefits of Particle Filtration

Energy Technology Data Exchange (ETDEWEB)

Fisk, William J.

2013-10-01

The evidence of health benefits of particle filtration in homes and commercial buildings is reviewed. Prior reviews of papers published before 2000 are summarized. The results of 16 more recent intervention studies are compiled and analyzed. Also, reviewed are four studies that modeled health benefits of using filtration to reduce indoor exposures to particles from outdoors. Prior reviews generally concluded that particle filtration is, at best, a source of small improvements in allergy and asthma health effects; however, many early studies had weak designs. A majority of recent intervention studies employed strong designs and more of these studies report statistically significant improvements in health symptoms or objective health outcomes, particularly for subjects with allergies or asthma. The percent age improvement in health outcomes is typically modest, for example, 7percent to 25percent. Delivery of filtered air to the breathing zone of sleeping allergic or asthmatic persons may be more consistently effective in improving health than room air filtration. Notable are two studies that report statistically significant improvements, with filtration, in markers that predict future adverse coronary events. From modeling, the largest potential benefits of indoor particle filtration may be reductions in morbidity and mortality from reducing indoor exposures to particles from outdoor air.

Health Benefits of Particle Filtration

Energy Technology Data Exchange (ETDEWEB)

Fisk, William J.

2013-10-01

The evidence of health benefits of particle filtration in homes and commercial buildings is reviewed. Prior reviews of papers published before 2000 are summarized. The results of 16 more recent intervention studies are compiled and analyzed. Also reviewed are four studies that modeled health benefits of using filtration to reduce indoor exposures to particles from outdoors. Prior reviews generally concluded that particle filtration is, at best, a source of small improvements in allergy and asthma health effects; however, many early studies had weak designs. A majority of recent intervention studies employed strong designs and more of these studies report statistically significant improvements in health symptoms or objective health outcomes, particularly for subjects with allergies or asthma. The percentage improvement in health outcomes is typically modest, e.g., 7percent to 25percent. Delivery of filtered air to the breathing zone of sleeping allergic or asthmatic persons may be more consistently effective in improving health than room air filtration. Notable are two studies that report statistically significant improvements, with filtration, in markers that predict future adverse coronary events. From modeling, the largest potential benefits of indoor particle filtration may be reductions in morbidity and mortality from reducing indoor exposures to particles from outdoor air.

Filtration Behaviour and Fouling Mechanisms of Polysaccharides

Directory of Open Access Journals (Sweden)

Sondus Jamal

2014-07-01

Full Text Available This study investigated filtration behaviors of polysaccharides solutions, both alone and in mixture with proteins, in the short-time constant flux filtration with the focus on factors affecting the transmembrane pressure (TMP increase rate, the irreversible filtration resistance, and the membrane rejection behavior. The results showed that the TMP increase rates in the short-time constant flux filtration of alginate solutions were significantly affected by the calcium addition, alginate concentration, and flux. Although the addition of calcium resulted in a decrease in the TMP increase rate, it was found that the irreversible fouling developed during the filtration increased with the calcium addition, implying that the double-sided effect of calcium on membrane filtration and that the TMP increase rate observed in the filtration does not always reflect the irreversible membrane fouling development. It was also found that for the filtration of solutions containing mixed alginate and BSA, alginate exerted a dominant effect on the TMP increase rate and the membrane exhibited a reduced rejection to both alginate and BSA molecules compared to that in the filtration of the pure alginate or BSA.

Health Benefits of Particle Filtration

OpenAIRE

Fisk, William J.

2013-01-01

The evidence of health benefits of particle filtration in homes and commercial buildings is reviewed. Prior reviews of papers published before 2000 are summarized. The results of 16 more recent intervention studies are compiled and analyzed. Also reviewed are four studies that modeled health benefits of using filtration to reduce indoor exposures to particles from outdoors. Prior reviews generally concluded that particle filtration is, at best, a source of small improvements in allergy and as...

Aerosol filtration

International Nuclear Information System (INIS)

Klein, M.; Goossens, W.R.A.; De Smet, M.; Trine, J.; Hertschap, M.

1984-01-01

This report summarizes the work on the development of fibre metallic prefilters to be placed upstream of HEPA filters for the exhaust gases of nuclear process plants. Investigations at ambient and high temperature were carried out. Measurements of the filtration performance of Bekipor porous webs and sintered mats were performed in the AFLT (aerosol filtration at low temperature) unit with a throughput of 15 m 3 /h. A parametric study on the influence of particle size, fibre diameter, number of layers and superficial velocity led to the optimum choice of the working parameters. Three selected filter types were then tested with polydisperse aerosols using a candle-type filter configuration or a flat-type filter configuration. The small-diameter candle type is not well suited for a spraying nozzles regeneration system so that only the flat-type filter was retained for high-temperature tests. A high-temperature test unit (AFHT) with a throughput of 8 to 10 m 3 /h at 400 0 C was used to test the three filter types with an aerosol generated by high-temperature calcination of a simulated nitric acid waste solution traced with 134 Cs. The regeneration of the filter by spray washing and the effect of the regeneration on the filter performance was studied for the three filter types. The porous mats have a higher dust loading capacity than the sintered web which means that their regeneration frequency can be kept lower

Relation Between Filtration and Soil Consolidation Theories

Directory of Open Access Journals (Sweden)

Strzelecki Tomasz

2015-03-01

Full Text Available This paper presents a different, than commonly used, form of equations describing the filtration of a viscous compressible fluid through a porous medium in isothermal conditions. This mathematical model is compared with the liquid flow equations used in the theory of consolidation. It is shown that the current commonly used filtration model representation significantly differs from the filtration process representation in Biot’s and Terzaghi’s soil consolidation models, which has a bearing on the use of the methods of determining the filtration coefficient on the basis of oedometer test results. The present analysis of the filtration theory equations should help interpret effective parameters of the non-steady filtration model. Moreover, equations for the flow of a gas through a porous medium and an interpretation of the filtration model effective parameters in this case are presented.

Effect of hypothermic pulmonary artery flushing on capillary filtration coefficient.

Science.gov (United States)

Andrade, R S; Wangensteen, O D; Jo, J K; Tsai, M Y; Bolman, R M

2000-07-27

We previously demonstrated that surfactant dilution and inhibition occur immediately after pulmonary artery flushing with hypothermic modified Euro-Collins solution. Consequently, we speculated that increased capillary permeability contributed to these surfactant changes. To test this hypothesis, we evaluated the effects of hypothermic pulmonary artery flushing on the pulmonary capillary filtration coefficient (Kfc), and additionally performed a biochemical analysis of surfactant. We used a murine isolated, perfused lung model to measure the pulmonary capillary filtration coefficient and hemodynamic parameters, to determine the wet to dry weight ratio, and to evaluate surfactant by biochemical analysis of lung lavage fluid. We defined three study groups. In group I (controls), we harvested lungs without hypothermic pulmonary artery flushing, and measured Kfc immediately. In group II (in situ flush), we harvested lungs after hypothermic pulmonary artery flushing with modified Euro-Collins solution, and then measured Kfc. Experiments in groups I and II were designed to evaluate persistent changes in Kfc after pulmonary artery flushing. In group III (ex vivo flush), we flushed lungs ex vivo to evaluate transient changes in Kfc during hypothermic pulmonary artery flushing. Groups I and II did not differ significantly in capillary filtration coefficient and hemodynamics. Group II showed significant alterations on biochemical surfactant analysis and a significant increase in wet-to-dry weight ratio, when compared with group I. In group III, we observed a significant transient increase in capillary filtration coefficient during pulmonary artery flushing. Hypothermic pulmonary artery flushing transiently increases the capillary filtration coefficient, leads to an increase in the wet to dry weight ratio, and induces biochemical surfactant changes. These findings could be explained by the effects of hypothermic modified Euro-Collins solution on pulmonary capillary

Particle filtration in consolidated granular systems

International Nuclear Information System (INIS)

Schwartz, L.M.; Wilkinson, D.J.; Bolsterli, M.; Hammond, P.

1993-01-01

Grain-packing algorithms are used to model the mechanical trapping of dilute suspensions of particles by consolidated granular media. We study the distribution of filtrate particles, the formation of a damage zone (internal filter cake), and the transport properties of the host--filter-cake composite. At the early stages of filtration, our simulations suggest simple relationships between the structure of the internal filter cake and the characteristics of the underlying host matrix. These relationships are then used to describe the dynamics of the filtration process. Depending on the grain size and porosity of the host matrix, calculated filtration rates may either be greater than (spurt loss) or less than (due to internal clogging) those predicted by standard surface-filtration models

Health benefits of particle filtration.

Science.gov (United States)

Fisk, W J

2013-10-01

The evidence of health benefits of particle filtration in homes and commercial buildings is reviewed. Prior reviews of papers published before 2000 are summarized. The results of 16 more recent intervention studies are compiled and analyzed. Also, reviewed are four studies that modeled health benefits of using filtration to reduce indoor exposures to particles from outdoors. Prior reviews generally concluded that particle filtration is, at best, a source of small improvements in allergy and asthma health effects; however, many early studies had weak designs. A majority of recent intervention studies employed strong designs and more of these studies report statistically significant improvements in health symptoms or objective health outcomes, particularly for subjects with allergies or asthma. The percentage improvement in health outcomes is typically modest, for example, 7% to 25%. Delivery of filtered air to the breathing zone of sleeping allergic or asthmatic persons may be more consistently effective in improving health than room air filtration. Notable are two studies that report statistically significant improvements, with filtration, in markers that predict future adverse coronary events. From modeling, the largest potential benefits of indoor particle filtration may be reductions in morbidity and mortality from reducing indoor exposures to particles from outdoor air. Published 2013. This article is a US Government work and is in the public domain in the USA.

Direct filtration of Biesbosch water and Algae and water treatment in the Netherlands : 3rd Direct Filtration Seminar

NARCIS (Netherlands)

Petrusevski, B.; Vlaski, A.; Van Breemen, A.N.; Alaerts, G.J.

1993-01-01

This presentation summarises basic information on direct filtration, and demonstrates the main research findings, related to the performance of simple in-line direct filtration. The results reported are part of a comprehensive ongoing research programm "Direct filtration of Biesbosch water"

Inherently safe characteristics of nuclear reactors

International Nuclear Information System (INIS)

1989-01-01

This report is based on a detailed study which was carried out by Colenco (a company of the Motor-Columbus Group) on behalf of the Commission of the European Communities (CEC). It presents a summary of this study and concentrates more on the generic issues involved in the subject of inherent safety in nuclear power plants. It is assumed that the reader is reasonably familiar with the design outline of the systems included in the report. The report examines the role of inherent design features in achieving the safety of nuclear power plants as an alternative to the practice, which is largely followed in current reactors, of achieving safety by the addition of engineered safety features. The report examines current reactor systems to identify the extent to which their characteristics are either already inherently safe or, on the other hand, have inherent characteristics that require protective action to be taken. It then considers the advantages of introducing design changes to improve their inherent safety characteristics. Next, it looks at some new reactor types for which claims of inherent safety are made to see to what extent these claims are justified. The general question is then considered whether adoption of the inherently safe reactors would give advantages (by reducing risk in real terms or by improving the public acceptability of nuclear power) which are sufficient to offset the expected high costs and the technical risks associated with any new technology

Filtration approach to mitigate indoor Thoron progeny concentration

International Nuclear Information System (INIS)

Wang, J.; Meisenberg, O.; Karg, E.; Tschiersch, J.; Chen, Y.

2010-01-01

This study investigates filtration of air as potential mitigation method of thoron progeny exposure. The experiments were conducted in a model room (volume 7.1 m 3 ) which was equipped with a pump and an HEPA (high efficiency particulate air) filter. Filtration at a rate of 0.2, 0.4, 0.5 and 0.8 h -1 during 88 h proved an effective practice in reducing the total indoor thoron decay product concentration. The results indicate that 0.4-0.8 h -1 filtration rate had almost the same filtration efficiency in decreasing the total thoron EEC (equilibrium equivalent concentration) by 97% while 80% of total thoron EEC were reduced by 0.2 h -1 filtration rate; meanwhile, the unattached thoron EEC rose significantly by 190, 270, 290%, respectively under 0.4-0.8 h -1 filtration rate, whereas 0.2 h -1 filtration rate increased unattached thoron EEC by 40%. The aerosol number size distribution variation reveals that filtration operation removes smaller particles faster or earlier than the larger ones. The annual effective dose calculated was reduced by 91-92% at a filtration rate of 0.4-0.8 h -1 while 75% reduced at 0.2 h -1 filtration rate after 88 h filtration process. (authors)

Portable field water sample filtration unit

International Nuclear Information System (INIS)

Hebert, A.J.; Young, G.G.

1977-01-01

A lightweight back-packable field-tested filtration unit is described. The unit is easily cleaned without cross contamination at the part-per-billion level and allows rapid filtration of boiling hot and sometimes muddy water. The filtration results in samples that are free of bacteria and particulates and which resist algae growth even after storage for months. 3 figures

Visualization and evaluation of flow during water filtration: Parameterization and sensitivity analysis

Directory of Open Access Journals (Sweden)

Bílek Petr

2016-01-01

Full Text Available This paper deals with visualization and evaluation of flow during filtration of water seeded by artificial microscopic particles. Planar laser induced fluorescence (PLIF is a wide spread method for visualization and non-invasive characterization of flow. However the method uses fluorescent dyes or fluorescent particles in special cases. In this article the flow is seeded by non-fluorescent monodisperse polystyrene particles with the diameter smaller than one micrometer. The monodisperse sub-micron particles are very suitable for testing of textile filtration materials. Nevertheless non-fluorescent particles are not useful for PLIF method. A water filtration setup with an optical access to the place, were a tested filter is mounted, was built and used for the experiments. Concentration of particles in front of and behind the tested filter in a laser light sheet measured is and the local filtration efficiency expressed is. The article describes further progress in the measurement. It was carried out sensitivity analysis, parameterization and performance of the method during several simulations and experiments.

Problems of multiphase fluid filtration

CERN Document Server

Konovalov, AN

1994-01-01

This book deals with a spectrum of problems related to the mathematical modeling of multiphase filtration. Emphasis is placed on an inseparable triad: model - algorithm - computer code. An analysis of new and traditional filtration problems from the point of view of both their numerical implementation and the reproduction of one or another technological characteristics of the processes under consideration is given. The basic principles which underlie the construction of efficient numerical methods taking into account the filtration problems are discussed: non-evolutionary nature, degeneration,

DQE of wireless digital detectors: Comparative performance with differing filtration schemes

Energy Technology Data Exchange (ETDEWEB)

Samei, Ehsan [Carl E. Ravin Advanced Imaging Laboratories, Departments of Radiology, Biomedical Engineering, Physics, and Electrical and Computer Engineering, Medical Physics Graduate Program, Duke University Medical Center, Durham, North Carolina 27705 (United States); Murphy, Simon; Christianson, Olav [Medical Physics Graduate Program, Duke University, Durham, North Carolina 27705 (United States)

2013-08-15

Purpose: Wireless flat panel detectors are gaining increased usage in portable medical imaging. Two such detectors were evaluated and compared with a conventional flat-panel detector using the formalism of the International Electrotechnical Commission (IEC 62220-1) for measuring modulation transfer function (MTF), normalized noise power spectrum (NNPS), and detective quantum efficiency (DQE) using two different filtration schemes.Methods: Raw images were acquired for three image receptors (DRX-1C and DRX-1, Carestream Health; Inc., Pixium 4600, Trixell) using a radiographic system with a well-characterized output (Philips Super80 CP, Philips Healthcare). Free in-air exposures were measured using a calibrated radiation meter (Unfors Mult-O-Meter Type 407, Unfors Instruments AB). Additional aluminum filtration and a new alternative combined copper-aluminum filtration were used to conform the x ray output to IEC-specified beam quality definitions RQA5 and RQA9. Using the IEC 62220-1 formalism, each detector was evaluated at X{sub N}/2, X{sub N}, and 2X{sub N}, where the normal exposure level to the detector surface (X{sub N}) was set to 8.73 μGy (1.0 mR). The prescribed edge test device was used to evaluate the MTF, while the NNPS was measured using uniform images. The DQE was then calculated from the MTF and NNPS and compared across detectors, exposures, and filtration schemes.Results: The three DR systems had largely comparable MTFs with DRX-1 demonstrating lower values above 1.0 cycles/mm. At each exposure, DRX-1C and Pixium detectors demonstrated better noise performance than that of DRX-1. Zero-frequency DQEs for DRX-1C, Pixium, and DRX-1 detectors were approximately 74%, 63%, and 38% for RQA5 and 50%, 42%, and 28% for RQA9, respectively.Conclusions: DRX-1C detector exhibited superior DQE performance compared to Pixium and DRX-1. In terms of filtration, the alternative filtration was found to provide comparable performance in terms of rank ordering of different

Magnetic-seeding filtration

International Nuclear Information System (INIS)

Depaoli, D.

1996-01-01

This task will investigate the capabilities of magnetic-seeding filtration for the enhanced removal of magnetic and nonmagnetic particulates from liquids. This technology appies to a wide range of liquid wastes, including groundwater, process waters, and tank supernatant. Magnetic-seeding filtration can be used in several aspects of treatment, such as (1) removal of solids, particularly those in the colloidal-size range that are difficult to remove by conventional means; (2) removal of contaminants by precipitation processes; and (3) removal of contaminants by sorption processes

Latest aspects of mechanical filtration

Directory of Open Access Journals (Sweden)

Stanislav Koláček

2013-01-01

Full Text Available The aim of this study was to describe and unify all knowledge about mechanic filtration. The first part deals with the parameters and properties of filtration. Here some important basic concepts are explained such as pressure gradient, filter life, etc. There’s also a description of convenient filtration technology for coarse and fine materials, such as sand, smoke or soot. The second part primarily focuses on the real use and application of filters for liquid and gaseous media. The differences in construction between different types of filters for filtration of fuels, oils, hydraulic fluids, air and cabin filters are described. The last section is focused mainly on new materials for the production of filters. These materials are ceramic or nanomaterials, which can actually be enriched for example with antibacterial silver or some fungicides.

Inherent/passive safety in fusion power plants

International Nuclear Information System (INIS)

Piet, S.J.; Crocker, J.G.

1986-01-01

The concept of inherent or passive safety for fusion energy is explored, defined, and partially quantified. Four levels of safety assurance are defined, which range from true inherent safety to passive safety to protection via active engineered safeguard systems. Fusion has the clear potential for achieving inherent or passive safety, which should be an objective of fusion research and design. Proper material choice might lead to both inherent/passive safety and high mass power density, improving both safety and economics. When inherent or passive safety is accomplished, fusion will be well on the way to achieving its ultimate potential and to be a truly superior energy source for the future

The Effect of Cyanobacterial Biomass Enrichment by Centrifugation and GF/C Filtration on Subsequent Microcystin Measurement

Directory of Open Access Journals (Sweden)

Shelley Rogers

2015-03-01

Full Text Available Microcystins are cyclic peptides produced by multiple cyanobacterial genera. After accumulation in the liver of animals they inhibit eukaryotic serine/threonine protein phosphatases, causing liver disease or death. Accurate detection/quantification of microcystins is essential to ensure safe water resources and to enable research on this toxin. Previous methodological comparisons have focused on detection and extraction techniques, but have not investigated the commonly used biomass enrichment steps. These enrichment steps could modulate toxin production as recent studies have demonstrated that high cyanobacterial cell densities cause increased microcystin levels. In this study, three microcystin-producing strains were processed using no cell enrichment steps (by direct freezing at three temperatures and with biomass enrichment (by centrifugation or GF/C filtration. After extraction, microcystins were analyzed using liquid chromatography-tandem mass spectrometry. All processing methods tested, except GF/C filtration, resulted in comparable microcystin quotas for all strains. The low yields observed for the filtration samples were caused by adsorption of arginine-containing microcystins to the GF/C filters. Whilst biomass enrichment did not affect microcystin metabolism over the time-frame of normal sample processing, problems associated with GF/C filtration were identified. The most widely applicable processing method was direct freezing of samples as it could be utilized in both field and laboratory environments.

Urological disorders in chronic kidney disease in children cohort: clinical characteristics and estimation of glomerular filtration rate.

Science.gov (United States)

Dodson, Jennifer L; Jerry-Fluker, Judith V; Ng, Derek K; Moxey-Mims, Marva; Schwartz, George J; Dharnidharka, Vikas R; Warady, Bradley A; Furth, Susan L

2011-10-01

Urological disorders are the most common cause of pediatric chronic kidney disease. We determined the characteristics of children with urological disorders and assessed the agreement between the newly developed bedside glomerular filtration rate estimating formula with measured glomerular filtration rate in 586 patients in the Chronic Kidney Disease in Children study. The Chronic Kidney Disease in Children study is a prospective, observational cohort of children recruited from 48 sites in the United States and Canada. Eligibility requirements include age 1 to 16 years and estimated glomerular filtration rate by original Schwartz formula 30 to 90 ml/min/1.73 m(2). Baseline demographics, clinical variables and glomerular filtration rate were assessed. Bland-Altman analysis was conducted to assess agreement between estimated and measured glomerular filtration rates. Of the 586 participants with at least 1 glomerular filtration rate measurement 348 (59%) had an underlying urological diagnosis (obstructive uropathy in 118, aplastic/hypoplastic/dysplastic kidneys in 104, reflux in 87 and other condition in 39). Among these patients median age was 9 years, duration of chronic kidney disease was 7 years and age at first visit with a urologist was less than 1 year. Of the patients 67% were male, 67% were white and 21% had a low birth weight. Median height was in the 24th percentile. Median glomerular filtration rate as measured by iohexol plasma disappearance was 44.8 ml/min/1.73 m(2). Median glomerular filtration rate as estimated by the Chronic Kidney Disease in Children bedside equation was 44.3 ml/min/1.73 m(2) (bias = -0.5, 95% CI -1.7 to 0.7, p = 0.44). Underlying urological causes of chronic kidney disease were present in 59% of study participants. These children were diagnosed early in life, and many had low birth weight and growth delay. There is good agreement between the newly developed Chronic Kidney Disease in Children estimating equations and measured

Fusion blanket inherent safety assessment

International Nuclear Information System (INIS)

Sze, D.K.; Jung, J.; Cheng, E.T.

1986-01-01

Fusion has significant potential safety advantages. There is a strong incentive for designing fusion plants to ensure that inherent safety will be achieved. Accordingly, both the Tokamak Power Systems Studies and MINIMARS have identified inherent safety as a design goal. A necessary condition is for the blanket to maintain its configuration and integrity under all credible accident conditions. A main problem is caused by afterheat removal in an accident condition. In this regard, it is highly desirable to achieve the required level of protection of the plant capital investment and limitation of radioactivity release by systems that rely only on inherent properties of matter (e.g., thermal conductivity, specific heat, etc.) and without the use of active safety equipment. This paper assesses the conditions under which inherent safety is feasible. Three types of accident conditions are evaluated for two blankets. The blankets evaluated are a self cooled vanadium/lithium blanket and a self-cooled vanadium/Flibe blanket. The accident conditions evaluated are: (1) loss-of-flow accident; (2) loss-of-coolant accident (LOCA); and (3) partial loss-of-coolant accident

40 CFR 141.174 - Filtration sampling requirements.

Science.gov (United States)

2010-07-01

... PROGRAMS (CONTINUED) NATIONAL PRIMARY DRINKING WATER REGULATIONS Enhanced Filtration and Disinfection... water system subject to the requirements of this subpart that provides conventional filtration treatment... 40 Protection of Environment 22 2010-07-01 2010-07-01 false Filtration sampling requirements. 141...

Measure of pore size in micro filtration polymeric membrane using ultrasonic technique and artificial neural networks

International Nuclear Information System (INIS)

Lucas, Carla de Souza

2009-01-01

This work presents a study of the pore size in micro filtration polymeric membranes, used in the nuclear area for the filtration of radioactive liquid effluent, in the residual water treatment of the petrochemical industry, in the electronic industry for the ultrapure water production for the manufacture of conductors and laundering of microcircuits and in many other processes of separation. Diverse processes for measures of pores sizes in membranes exist, amongst these, electronic microscopy, of bubble point and mercury intrusion porosimetry, however the majority of these uses destructive techniques, of high cost or great time of analysis. The proposal of this work is to measure so great of pore being used ultrasonic technique in the time domain of the frequency and artificial neural networks. A receiving/generator of ultrasonic pulses, a immersion transducer of 25 MHz was used, a tank of immersion and microporous membranes of pores sizes of 0,2 μm, 0,4 μm, 0,6 μm, 8 μm, 10 μm and 12 μm. The ultrasonic signals after to cover the membrane, come back to the transducer (emitting/receiving) bringing information of the interaction of the signal with the membranes. These signals had been used for the training of neural networks, and these had supplied the necessary precision the distinction of the same ones. Soon after, technique with the one of electronic microscopy of sweepings was made the comparison of this. The experiment showed very resulted next to the results gotten with the MEV, what it indicated that the studied technique is ideal for measure of pore size in membranes for being not destructive and of this form to be able to be used also on-line of production. (author)

40 CFR 141.73 - Filtration.

Science.gov (United States)

2010-07-01

... Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) WATER PROGRAMS (CONTINUED) NATIONAL PRIMARY DRINKING WATER REGULATIONS Filtration and Disinfection § 141.73 Filtration. A public water system that uses a surface water source or a ground water source under the direct influence of surface water...

40 CFR 141.719 - Additional filtration toolbox components.

Science.gov (United States)

2010-07-01

... taken from a surface water or GWUDI source. A cap, such as GAC, on a single stage of filtration is not... separate stage of filtration if both filtration stages treat entire plant flow taken from a surface water... 40 Protection of Environment 22 2010-07-01 2010-07-01 false Additional filtration toolbox...

Aerosol filtration

International Nuclear Information System (INIS)

First, M.W.; Gilbert, H.

1981-01-01

Significant developments in high efficiency filtration for nuclear applications are reviewed for the period 1968 to 1980. Topics of special interest include factory (bench) and in-place test methods, new developments in paper and filter unit construction methods, vented containment air cleaning systems for LMFBR and light water moderated reactors, and decontamination of offgases from nuclear waste volume reduction processes. It is noted that standards development has been vigorously pursued during this period but that advances in filtration theory have been few. One of the significant changes likely to occur in the immediate future is adoption of the European style of HEPA filters for those that have been in service for the past three decades to obtain the benefits of having almost twice as much filter paper in the same filter cartridge. 71 references

A general index of inherent risk

OpenAIRE

Schnytzer, Adi; Westreich, Sara

2009-01-01

We extend the pioneering work of Aumann and Serrano by presenting an index of inherent riskiness of a gamble having the desirable properties of their index, while being applicable to gambles with either positive or negative expectations. As such, our index provides a measure of riskiness which is of use for both risk lovers and risk aversive gamblers, and is defined for all discrete and a large class of continuous gambles. We analyze abstract properties of our index, and present in addition t...

The effect of filtration on radon daughter atmospheres: Laboratory and field experiments

International Nuclear Information System (INIS)

Jonassen, N.; Jensen, B.

1987-01-01

Airborne radon daughters may be removed from the air by internal filtration using mechanical or electrofilters. The effect of the filtration may be evaluated in absolute measure by the decrease in the potential alpha energy concentration (or equivalent equilibrium concentration) or relatively by the decrease in the equilibrium factor. The filtration, however, may also change the distribution of airborne radon daughter activity between the unattached and the aerosol-attached state in a way to increase the radiological dose corresponding to a given potential alpha energy concentration. The paper describes a series of laboratory and field experiments which indicate that it is possible by the use of household electrofilters with filtration rates of 2-3 h -1 to lower the radon daughter concentrations to about 20 -30 % and the average radiological dose to about 50-60 % of the value in unfiltered air

Modeling the filtration ability of stockpiled filtering facepiece

Science.gov (United States)

Rottach, Dana R.

2016-03-01

Filtering facepiece respirators (FFR) are often stockpiled for use during public health emergencies such as an infectious disease outbreak or pandemic. While many stockpile administrators are aware of shelf life limitations, environmental conditions can lead to premature degradation. Filtration performance of a set of FFR retrieved from a storage room with failed environmental controls was measured. Though within the expected shelf life, the filtration ability of several respirators was degraded, allowing twice the penetration of fresh samples. The traditional picture of small particle capture by fibrous filter media qualitatively separates the effect of inertial impaction, interception from the streamline, diffusion, settling, and electrostatic attraction. Most of these mechanisms depend upon stable conformational properties. However, common FFR rely on electrets to achieve their high performance, and over time heat and humidity can cause the electrostatic media to degrade. An extension of the Langevin model with correlations to classical filtration concepts will be presented. The new computational model will be used to predict the change in filter effectiveness as the filter media changes with time.

Side Stream Filtration for Cooling Towers

Energy Technology Data Exchange (ETDEWEB)

None

2012-10-20

This technology evaluation assesses side stream filtration options for cooling towers, with an objective to assess key attributes that optimize energy and water savings along with providing information on specific technology and implementation options. This information can be used to assist Federal sites to determine which options may be most appropriate for their applications. This evaluation provides an overview of the characterization of side stream filtration technology, describes typical applications, and details specific types of filtration technology.

Cake creep during filtration of flocculated manure

DEFF Research Database (Denmark)

Christensen, Morten Lykkegaard; Keiding, Kristian

is filtered. Hence, it is not possible to scale up the experiments, and it is therefore difficult to optimize the flocculation and estimate the needed filter media area. Similar problems have been observed when sewage sludge and synthetic core-shell colloids are filtered, and it has been suggested......, and the mixing procedure affect the result, and lab-scale experiments are often used to study how these pre-treatments influence the filtration process. However, the existing mathematical filtration models are based on filtration of inorganic particles and cannot simulate the filtration data obtained when manure...

The Fundamentals of Waste Water Sludge Characterization and Filtration

Energy Technology Data Exchange (ETDEWEB)

Scales, Peter J.; Dixon, David R.; Harbour, Peter J.; Stickland, Anthony D.

2003-07-01

The move to greater emphasis on the disposal of waste water sludges through routes such as incineration and the added cost of landfill emplacement puts high demands on dewatering technology for these sludges. A dear problem in this area is that waste water sludges are slow and difficult to dewater and traditional methods of laboratory measurement for prediction of filtration performance are inadequate. This is highly problematic for the design and operational optimisation of centrifuges, filters and settling devices in the waste water industry. The behaviour is assessed as being due to non-linear behaviour of these sludges which negates the use of classical approaches. These approaches utilise the linear portion of a t versus V{sup 2} plot (where t is the time to filtration and V is the specific filtrate volume) to extract a simple Darcian permeability. Without this parameter, a predictive capacity for dewatering using current theory is negated. (author)

Characterization, Washing, Leaching, and Filtration of C-104 Sludge

Energy Technology Data Exchange (ETDEWEB)

KP Brooks; PR Bredt; GR Golcar; SA Hartley; LK Jagoda; KG Rappe; MW Urie

2000-06-09

Approximately 1,400 g of wet Hanford Tank C-104 Sludge was evaluated by Battelle for the high-level waste (HLW) pretreatment processes of ultrafiltration, dilute caustic washing, and elevated-temperature caustic leaching. The filterability of diluted C-104 sludge was measured with a 0.1-{micro}m sintered metal Mott filter using a 24-inch-long, single-element, crossflow filtration system (cells unit filter [CUF]). While the filtrate was being recirculated prior to washing and leaching, a 6.9 wt% solids slurry was evaluated with a matrix of seven 1-hour conditions of varying trans-membrane pressure (30 to 70 psid) and axial velocity (9 to 15 ft/s). The filtrate flux and backpulse efficiency were determined for each condition. The slurry was concentrated to 23 wt% solids, a second matrix of six 1-hour conditions was performed, and data analogous to that recorded in the first matrix were obtained. The low-solids-concentration matrix produced filtrate flux rates that ranged from 0.038 to 0.083 gpm/ft{sup 2}. The high-solids-concentration matrix produced filtrate flux rates that ranged from 0.0095 to 0.0172 gpm/ft{sup 2}. In both cases, the optimum filtrate flux was at the highest axial velocity (15 ft/s) and transmembrane pressure had little effect. Nearly all of the measured filtrate fluxes were more than an order of magnitude greater than the required plant flux for C-104 of 0.00126 gpm/ft{sup 2}. In both matrices, the filtrate flux appeared to be proportional to axial velocity, and the permeability appeared to be inversely proportional to the trans-membrane pressure. The first test condition was repeated as the last test condition for each matrix. In both cases, there was a significant decrease in filtrate flux, indicating some filter fouling during the test matrix that could not be removed by backpulsing alone, although the backpulse number and duration were not optimized. Following testing of these two matrices, the material was washed within the CUF by

21 CFR 177.2910 - Ultra-filtration membranes.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Ultra-filtration membranes. 177.2910 Section 177... Components of Articles Intended for Repeated Use § 177.2910 Ultra-filtration membranes. Ultra-filtration membranes identified in paragraphs (a)(1), (a)(2), (a)(3), and (a)(4) of this section may be safely used in...

Aerosol filtration

International Nuclear Information System (INIS)

First, M.W.; Gilbert, H.

1982-01-01

Significant developments in high-efficiency filtration for nuclear applications are reviewed for the period 1968 to 1980. Topics of special interest include (1) factory (bench) and in-place test methods, (2) new developments in paper and filter unit construction methods, (3) vented containment air cleaning systems for liquid-metal fast breeder reactors and light-water-moderated reactors, and (4) decontamination of off-gases from nuclear waste volume-reduction processes. Standards development has been vigorously pursued during this period, but advances in filtration theory have been few. One of the significant changes likely to occur in the immediate future is adoption of the European style of high-efficiency particulate air filters instead of those which have been in service for the past three decades to obtain the benefits of having almost twice as much filter paper in the same filter cartridge

Operation: Inherent Resolve

DEFF Research Database (Denmark)

Cramer-Larsen, Lars

2015-01-01

Kapitlet giver læseren indsigt i den internationale koalitions engagement mod IS igennem Operaton Inherent Resolve; herunder koalitionens strategi i forhold til IS strategi, ligesom det belyser kampagnens legalitet og folkeretlige grundlag, ligesom det giver et bud på overvejelser om kampagnens...

Filtration effectiveness of HVAC systems at near-roadway schools.

Science.gov (United States)

McCarthy, M C; Ludwig, J F; Brown, S G; Vaughn, D L; Roberts, P T

2013-06-01

Concern for the exposure of children attending schools located near busy roadways to toxic, traffic-related air pollutants has raised questions regarding the environmental benefits of advanced heating, ventilation, and air-conditioning (HVAC) filtration systems for near-road pollution. Levels of black carbon and gaseous pollutants were measured at three indoor classroom sites and at seven outdoor monitoring sites at Las Vegas schools. Initial HVAC filtration systems effected a 31-66% reduction in black carbon particle concentrations inside three schools compared with ambient air concentrations. After improved filtration systems were installed, black carbon particle concentrations were reduced by 74-97% inside three classrooms relative to ambient air concentrations. Average black carbon particle concentrations inside the schools with improved filtration systems were lower than typical ambient Las Vegas concentrations by 49-96%. Gaseous pollutants were higher indoors than outdoors. The higher indoor concentrations most likely originated at least partially from indoor sources, which were not targeted as part of this intervention. Recent literature has demonstrated adverse health effects in subjects exposed to ambient air near major roadways. Current smart growth planning and infill development often require that buildings such as schools are built near major roadways. Improving the filtration systems of a school's HVAC system was shown to decrease children's exposure to near-roadway diesel particulate matter. However, reducing exposure to the gas-phase air toxics, which primarily originated from indoor sources, may require multiple filter passes on recirculated air. © 2012 John Wiley & Sons A/S. Published by Blackwell Publishing Ltd.

BWR condensate filtration studies

International Nuclear Information System (INIS)

Wilson, J.A.; Pasricha, A.; Rekart, T.E.

1993-09-01

Poor removal of particulate corrosion products (especially iron) from condensate is one of the major problems in BWR systems. The presence of activated corrosion products creates ''hot spots'' and increases piping dose rates. Also, fuel efficiency is reduced and the risk of fuel failure is increased by the deposit of corrosion products on the fuel. Because of these concerns, current EPRI guidelines call for a maximum of 2 ppb of iron in the reactor feedwater with a level of 0.5 ppb being especially desirable. It has become clear that conventional deep bed resins are incapable of meeting these levels. While installation of prefilter systems is an option, it would be more economical for plants with naked deep beds to find an improved bead resin for use in existing systems. BWR condensate filtration technologies are being tested on a condensate side stream at Hope Creek Nuclear Generating Station. After two years of testing, hollow fiber filters (HFF) and fiber matrix filters (FMF), and low crosslink cation resin, all provide acceptable results. The results are presented for pressure drop, filtration efficiency, and water quality measurements. The costs are compared for backwashable non-precoat HFF and FMF. Results are also presented for full deep bed vessel tests of the low crosslink cation resin

Osculum dynamics and filtration activity in small single-osculum explants of the demosponge Halichondria panicea

DEFF Research Database (Denmark)

Kumala, Lars; Riisgård, Hans Ulrik; Canfield, Donald Eugene

2017-01-01

the clearance method. Osculum dynamics, as expressed by temporal variation of the OSA, including osculum contraction and expansion, correlated with variability in the explant filtration rate, and no water pumping was observed during periods of osculum closure. A linear relationship between filtration rate (FR......Contraction-inflation behavior, including the closure and opening of the exhalant opening (osculum), is common among sponges. This behavior may temporally affect filtration activity, making it difficult to study and understand sponge feeding biology. To examine the interplay between osculum...... dynamics and filtration activity, small (18 mm3) single-osculum explants of the demosponge Halichondria panicea were studied. Time-lapse video stereo-microscope recordings of the osculum cross-sectional area (OSA) were made simultaneously with measurements of the filtration rate (∼15°C, ∼20 PSU) using...

Inherent work suit buoyancy distribution: effects on lifejacket self-righting performance.

Science.gov (United States)

Barwood, Martin J; Long, Geoffrey M; Lunt, Heather; Tipton, Michael J

2014-09-01

Accidental immersion in cold water is an occupational risk. Work suits and life jackets (LJ) should work effectively in combination to keep the airway clear of the water (freeboard) and enable self-righting. We hypothesized that inherent buoyancy, in the suit or LJ, would be beneficial for enabling freeboard, but its distribution may influence LJ self-righting. Six participants consented to complete nine immersions. Suits and LJ tested were: flotation suit (FLOAT; 85 N inherent buoyancy); oilskins 1 (OS-1) and 2 (OS-2), both with no inherent buoyancy; LJs (inherent buoyancy/buoyancy after inflation/total buoyancy), LJ-1 50/150/200 N, LJ-2 0/290/290 N, LJ-3 80/190/270 N. Once dressed, the subject entered an immersion pool where uninflated freeboard, self-righting performance, and inflated freeboard were measured. Data were compared using Friedman's test to the 0.05 alpha level. All suits and LJs enabled uninflated and inflated freeboard, but differences were seen between the suits and LJs. Self-righting was achieved on 43 of 54 occasions, irrespective of suit or LJ. On all occasions that self-righting was not achieved, this occurred in an LJ that included inherent buoyancy (11/54 occasions). Of these 11 failures, 8 occurred (73% of occasions) when the FLOAT suit was being worn. LJs that included inherent buoyancy, that are certified as effective on their own, worked less effectively from the perspective of self-righting in combination with a work suit that also included inherent buoyancy. Equipment that is approved for use in the workplace should be tested in combination to ensure adequate performance in an emergency scenario.

Quantitative measurement and visualization of biofilm O 2 consumption rates in membrane filtration systems

KAUST Repository

Prest, Emmanuelle I E C; Staal, Marc J.; Kü hl, Michael; van Loosdrecht, Mark C.M.; Vrouwenvelder, Johannes S.

2012-01-01

There is a strong need for techniques enabling direct assessment of biological activity of biofouling in membrane filtration systems. Here we present a new quantitative and non-destructive method for mapping O 2 dynamics in biofilms during

Projective Dimension in Filtrated K-Theory

DEFF Research Database (Denmark)

Bentmann, Rasmus Moritz

2013-01-01

Under mild assumptions, we characterise modules with projective resolutions of length n∈N in the target category of filtrated K-theory over a finite topological space in terms of two conditions involving certain Tor -groups. We show that the filtrated K-theory of any separable C∗dash-algebra over...... any topological space with at most four points has projective dimension 2 or less. We observe that this implies a universal coefficient theorem for rational equivariant KK-theory over these spaces. As a contrasting example, we find a separable C∗dash-algebra in the bootstrap class over a certain five......-point space, the filtrated K-theory of which has projective dimension 3. Finally, as an application of our investigations, we exhibit Cuntz-Krieger algebras which have projective dimension 2 in filtrated K-theory over their respective primitive spectrum....

Air filtration in HVAC systems

CERN Document Server

Ginestet, Alain; Tronville, Paolo; Hyttinen, Marko

2010-01-01

Air filtration Guidebook will help the designer and user to understand the background and criteria for air filtration, how to select air filters and avoid problems associated with hygienic and other conditions at operation of air filters. The selection of air filters is based on external conditions such as levels of existing pollutants, indoor air quality and energy efficiency requirements.

SU-E-I-62: Assessing Radiation Dose Reduction and CT Image Optimization Through the Measurement and Analysis of the Detector Quantum Efficiency (DQE) of CT Images Using Different Beam Hardening Filters

International Nuclear Information System (INIS)

Collier, J; Aldoohan, S; Gill, K

2014-01-01

Purpose: Reducing patient dose while maintaining (or even improving) image quality is one of the foremost goals in CT imaging. To this end, we consider the feasibility of optimizing CT scan protocols in conjunction with the application of different beam-hardening filtrations and assess this augmentation through noise-power spectrum (NPS) and detector quantum efficiency (DQE) analysis. Methods: American College of Radiology (ACR) and Catphan phantoms (The Phantom Laboratory) were scanned with a 64 slice CT scanner when additional filtration of thickness and composition (e.g., copper, nickel, tantalum, titanium, and tungsten) had been applied. A MATLAB-based code was employed to calculate the image of noise NPS. The Catphan Image Owl software suite was then used to compute the modulated transfer function (MTF) responses of the scanner. The DQE for each additional filter, including the inherent filtration, was then computed from these values. Finally, CT dose index (CTDIvol) values were obtained for each applied filtration through the use of a 100 mm pencil ionization chamber and CT dose phantom. Results: NPS, MTF, and DQE values were computed for each applied filtration and compared to the reference case of inherent beam-hardening filtration only. Results showed that the NPS values were reduced between 5 and 12% compared to inherent filtration case. Additionally, CTDIvol values were reduced between 15 and 27% depending on the composition of filtration applied. However, no noticeable changes in image contrast-to-noise ratios were noted. Conclusion: The reduction in the quanta noise section of the NPS profile found in this phantom-based study is encouraging. The reduction in both noise and dose through the application of beam-hardening filters is reflected in our phantom image quality. However, further investigation is needed to ascertain the applicability of this approach to reducing patient dose while maintaining diagnostically acceptable image qualities in a

EM Task 9 - Centrifugal membrane filtration

International Nuclear Information System (INIS)

Stepan, Daniel J.; Stevens, Bradley G.; Hetland, Melanie D.

1999-01-01

The overall project consists of several integrated research phases related to the applicability, continued development, demonstration, and commercialization of the SpinTek centrifugal membrane filtration process. Work performed during this reporting period consisted of Phase 2 evaluation of the SpinTek centrifugal membrane filtration technology and Phase 3, Technology Partnering. During Phase 1 testing conducted at the EERC using the SpinTek ST-IIL unit operating on a surrogate tank waste, a solids cake developed on the membrane surface. The solids cake was observed where linear membrane velocities were less than 17.5 ft/s and reduced the unobstructed membrane surface area up to 25%, reducing overall filtration performance. The primary goal of the Phase 2 research effort was to enhance filtration performance through the development and testing of alternative turbulence promoter designs. The turbulence promoters were designed to generate a shear force across the entire membrane surface sufficient to maintain a self-cleaning membrane capability and improve filtration efficiency and long-term performance. Specific Phase 2 research activities included the following: System modifications to accommodate an 11-in.-diameter, two-disk rotating membrane assembly; Development and fabrication of alternative turbulence promoter designs; Testing and evaluation of the existing and alternative turbulence promoters under selected operating conditions using a statistically designed test matrix; and Data reduction and analysis; The objective of Phase 3 research was to demonstrate the effectiveness of SpinTek's centrifugal membrane filtration as a pretreatment to remove suspended solids from a liquid waste upstream of 3M's WWL cartridge technology for the selective removal of technetium (Tc)

Vibrating membrane filtration as improved technology for microalgae dewatering.

Science.gov (United States)

Nurra, Claudia; Clavero, Ester; Salvadó, Joan; Torras, Carles

2014-04-01

The effect of shear-enhanced filtration by vibratory process in microalgae dewatering is presented in this paper. The aim of this research was to investigate the technical performance and improvement of vibrating membrane filtration compared with conventional tangential cross-flow filtration in microalgae concentration. An industrial-scale available commercial set-up was used. Several membrane materials as polyethersulfone, polyacrylonitrile, etc., and mean pore sizes (from 7000Da to 0.2μm) were tested and compared in both filtration set-ups. Experiments were carried-out with Nannochloropsis gaditana and Phaeodactylum tricornutum microalgae. It has been demonstrated that, even if the choice of the membrane depends on its cut-off, its material and the type of microalgae filtrated, dynamic filtration is always the best technology over a conventional one. If with conventional filtration permeability values were in the vicinity of 10L/h/m(2)/bar in steady state phase, with dynamic filtration these values increased to 30L/h/m(2)/bar or more. Copyright © 2014 Elsevier Ltd. All rights reserved.

Simple method for the estimation of glomerular filtration rate

Energy Technology Data Exchange (ETDEWEB)

Groth, T [Group for Biomedical Informatics, Uppsala Univ. Data Center, Uppsala (Sweden); Tengstroem, B [District General Hospital, Skoevde (Sweden)

1977-02-01

A simple method is presented for indirect estimation of the glomerular filtration rate from two venous blood samples, drawn after a single injection of a small dose of (/sup 125/I)sodium iothalamate (10 ..mu..Ci). The method does not require exact dosage, as the first sample, taken after a few minutes (t=5 min) after injection, is used to normilize the value of the second sample, which should be taken in between 2 to 4 h after injection. The glomerular filtration rate, as measured by standard insulin clearance, may then be predicted from the logarithm of the normalized value and linear regression formulas with a standard error of estimate of the order of 1 to 2 ml/min/1.73 m/sup 2/. The slope-intercept method for direct estimation of glomerular filtration rate is also evaluated and found to significantly underestimate standard insulin clearance. The normalized 'single-point' method is concluded to be superior to the slope-intercept method and more sophisticated methods using curve fitting technique, with regard to predictive force and clinical applicability.

Prospects for inherently safe reactors

International Nuclear Information System (INIS)

Barkenbus, J.N.

1988-01-01

Public fears over nuclear safety have led some within the nuclear community to investigate the possibility of producing inherently safe nuclear reactors; that is, reactors that are transparently incapable of producing a core melt. While several promising designs of such reactors have been produced, support for large-scale research and development efforts has not been forthcoming. The prospects for commercialization of inherently safe reactors, therefore, are problematic; possible events such as further nuclear reactor accidents and superpower summits, could alter the present situation significantly. (author)

The effect of filter cake viscoelasticity on filtration

DEFF Research Database (Denmark)

Christensen, Morten Lykkegaard

, it is difficult to use the existing mathematical filtration models to simulate and optimise the filtration process. Activated sludge as well as synthetic model particles has been filtrated in this project. The study shows that compression of the formed filter cake is a time dependent process, and not only...

40 CFR 141.71 - Criteria for avoiding filtration.

Science.gov (United States)

2010-07-01

... PROGRAMS (CONTINUED) NATIONAL PRIMARY DRINKING WATER REGULATIONS Filtration and Disinfection § 141.71 Criteria for avoiding filtration. A public water system that uses a surface water source must meet all of...)(C)(iii), that filtration is required. A public water system that uses a ground water source under...

Development of a double-layered ceramic filter for aerosol filtration at high-temperatures: the filter collection efficiency.

Science.gov (United States)

de Freitas, Normanda L; Gonçalves, José A S; Innocentini, Murilo D M; Coury, José R

2006-08-25

The performance of double-layered ceramic filters for aerosol filtration at high temperatures was evaluated in this work. The filtering structure was composed of two layers: a thin granular membrane deposited on a reticulate ceramic support of high porosity. The goal was to minimize the high pressure drop inherent of granular structures, without decreasing their high collection efficiency for small particles. The reticulate support was developed using the technique of ceramic replication of polyurethane foam substrates of 45 and 75 pores per inch (ppi). The filtering membrane was prepared by depositing a thin layer of granular alumina-clay paste on one face of the support. Filters had their permeability and fractional collection efficiency analyzed for filtration of an airborne suspension of phosphatic rock in temperatures ranging from ambient to 700 degrees C. Results revealed that collection efficiency decreased with gas temperature and was enhanced with filtration time. Also, the support layer influenced the collection efficiency: the 75 ppi support was more effective than the 45 ppi. Particle collection efficiency dropped considerably for particles below 2 microm in diameter. The maximum collection occurred for particle diameters of approximately 3 microm, and decreased again for diameters between 4 and 8 microm. Such trend was successfully represented by the proposed correlation, which is based on the classical mechanisms acting on particle collection. Inertial impaction seems to be the predominant collection mechanism, with particle bouncing/re-entrainment acting as detachment mechanisms.

Relation Between Filtration and Soil Consolidation Theories

OpenAIRE

Strzelecki Tomasz; Strzelecki Michał

2015-01-01

This paper presents a different, than commonly used, form of equations describing the filtration of a viscous compressible fluid through a porous medium in isothermal conditions. This mathematical model is compared with the liquid flow equations used in the theory of consolidation. It is shown that the current commonly used filtration model representation significantly differs from the filtration process representation in Biot’s and Terzaghi’s soil consolidation models, which has a bearing on...

Salt disposition alternatives filtration at SRTC

International Nuclear Information System (INIS)

Walker, B. W.; Hobbs, D.

2000-01-01

Several of the prospective salt disposition alternative technologies require a monosodium titanate (MST) contact to remove strontium and actinides from inorganic salt solution feedstock. This feedstock also contains sludge solids from waste removal operations and may contain defoamers added in the evaporator systems. Filtration is required to remove the sludge and MST solids before sending the salt solution for further processing. This report describes testing performed using the Parallel Theological Experimental Filter (PREF). The PREF contains two single tube Mott sintered metal crossflow filters. For this test one filter was isolated so that the maximum velocities could be achieved. Previous studies showed slurries of MST and sludge in the presence of sodium tetraphenylborate (NaTPB) were filterable since the NaTPB slurry formed a filter cake which aided in removing the smaller MST and sludge particles. Some of the salt disposition alternative technologies do not use NaTPB raising the question of how effective crossflow filtration is with a feed stream containing only sludge and MST. Variables investigated included axial velocity, transmembrane pressure, defoamer effects, and solids concentration (MST and sludge). Details of the tests are outlined in the technical report WSRC-RP-98-O0691. Key conclusions from this study are: (1) Severe fouling of the Mott sintered metal filter did not occur with any of the solutions filtered. (2) The highest fluxes, in the range of .46 to 1.02 gpm/f 2 , were obtained when salt solution decanted from settled solids was fed to the filter. These fluxes would achieve 92 to 204 gpm filtrate production for the current ITP filters. The filtrate fluxes were close to the flux of 0.42 gpm/f 2 reported for In Tank Precipitation Salt Solution by Morrisey. (3) For the range of solids loading studied, the filter flux ranged from .04 to .17 gpm/f 2 which would result in a filtrate production rate of 9 to 31 gpm for the current HP filter. (4

Filtration Systems Design for Universal Oils in Agricultural Tractors

Directory of Open Access Journals (Sweden)

R. Majdan

2017-12-01

Full Text Available Three filtration systems using the tractor hydraulic circuit were proposed and verified during the tractors operation. Using the tractor-implement hydraulic system and filter body with accessories the universally useful filtration systems were designed. The designed filtration systems are the second stage of universal oil filtration whereas the first stage is the standard tractor filter. The decrease in the content of iron reached the values 25.53 %, 32.95 % and 41.55 % and the average decrease in oil contamination characterized by average value of decrease in content of iron, copper and silicium reached values 24.3 %, 24.7 % and 35.53 % in dependence on the filtration system and an oil contamination level. The decrease in contamination level verified the ability of designed filtration systems for agricultural tractors.

Filtration of Sludge and Sodium Nonatitanate Solutions

International Nuclear Information System (INIS)

Poirier, M.R.

2000-01-01

The proposed facility designs for the ion exchange and solvent extraction flowsheets under development to treat high level waste at the Savannah River Site use crossflow filtration to remove entrained sludge and monosodium titanate (MST). Bench-scale and pilot-scale testing performed with simulated feed streams showed much lower filtration rates than desired for the process. This report documents an investigation of the impact on filtration of using Honeywell sodium nonatitanate (ST), rather than MST, for strontium and actinide removal

The Perspective of Riverbank Filtration in China

Science.gov (United States)

Li, J.; Teng, Y.; Zhai, Y.; Zuo, R.

2014-12-01

Sustainable drinking water supply can affect the health of people, and the surrounding ecosystems. According to statistics of the monitoring program of drinking water sources in 309 at or above prefecture level of China in 2013, the major pollutants index were total phosphorus, ammonia and manganese in surface drinking water sources, respectively, iron, ammonia and manganese in groundwater drinking water sources, respectively. More than 150 drinking water emergency environmental accidents happened since 2006, 52 of these accidents led to the disruption of water supply in waterworks, and a population of over ten million were affected. It indicated that there is a potential risk for people's health by the use of river water directly and it is necessary to require alternative techniques such as riverbank filtration for improving the drinking water quality. Riverbank filtration is an inexpensive natural process, not only smoothing out normal pollutant concentration found in surface water but also significantly reducing the risk from such emergency events as chemical spill into the river. Riverbank filtration technique has been used in many countries more than 100 years, including China. In China, in 1950s, the bank infiltration technique was first applied in northeast of China. Extensive bank infiltration application was conducted in 1980s, and more than 300 drinking water sources utilities bank infiltration established mainly near the Songhua River Basin, the Yellow River Basin, Haihe River Basin. However, the comparative lack of application and researches on riverbank filtration have formed critical scientific data gap in China. As the performance of riverbank filtration technique depend on not only the design and setting such as well type, pumping rate, but also the local hydrogeology and environmental properties. We recommend more riverbank filtration project and studies to be conducted to collect related significant environmental geology data in China

Long-term indoor air conditioner filtration and cardiovascular health: A randomized crossover intervention study.

Science.gov (United States)

Chuang, Hsiao-Chi; Ho, Kin-Fai; Lin, Lian-Yu; Chang, Ta-Yuan; Hong, Gui-Bing; Ma, Chi-Ming; Liu, I-Jung; Chuang, Kai-Jen

2017-09-01

The association of short-term air pollution filtration with cardiovascular health has been documented. However, the effect of long-term indoor air conditioner filtration on the association between air pollution and cardiovascular health is still unclear. We recruited 200 homemakers from Taipei and randomly assigned 100 of them to air filtration or control intervention; six home visits were conducted per year from 2013 to 2014. The participants under air filtration intervention during 2013 were reassigned to control intervention in 2014. The air pollution measurements consisted of particulate matter less than or equal to 2.5μm in diameter (PM 2.5 ) and total volatile organic compounds (VOCs); blood pressure was monitored for each participant during each visit. The following morning, blood samples were collected after air pollution monitoring. The blood samples were used to analyze biological markers, including high sensitivity-C-reactive protein (hs-CRP), 8-hydroxy-2'-deoxyguanosine (8-OHdG) and fibrinogen. Household information, including cleaning, cooking, and air conditioning, was collected by a questionnaire. Mixed-effects models were used to investigate the associations among air pollution measurements, blood pressure and biological markers. The results showed that increased levels of PM 2.5 and total VOCs were associated with increased hs-CRP, 8-OHdG and blood pressure. The health variables were higher among participants in the control intervention phase than among those in the air filtration intervention phase. We concluded that air pollution exposure was associated with systemic inflammation, oxidative stress and elevated blood pressure. The long-term filtration of air pollution with an air conditioner filter was associated with cardiovascular health of adults. Copyright © 2017 Elsevier Ltd. All rights reserved.

Aerosol filtration with metallic fibrous filters

International Nuclear Information System (INIS)

Klein, M.; Goossens, W.R.A.

1983-01-01

The filtration efficiency of stainless steel fibrous filters (BEKIPOR porous mats and sintered webs) is determined using submicronic monodisperse polystyrene aerosols. Lasers spectrometers are used for the aerosol measurements. The parameters varied are the fiber diameter, the number of layers, the aerosol diameter and the superficial velocity. Two selected types of filters are tested with polydisperse methylene blue aerosols to determine the effect of bed loading on the filter performance and to test washing techniques for the regeneration of the filter

Approaches to achieving inherently safe fusion power plants

International Nuclear Information System (INIS)

Piet, S.J.

1986-01-01

Achieving inherently safe fusion facilities and conceptual designs is a challenge to the fusion community. Success should provide fusion with important competitive advantages versus other energy technologies. Inherent safety should mean a facility designed with passive safety features such that the public is protected from any acute fatalities under all credible accidental circumstances. A key aspect to inherent safety is demonstrability - the ability to prove that a deign is as safe as claimed. Three complementary approaches to achieving inherent safety are examined: toxin inventory reduction, energy source reduction and design fault tolerance. Four levels of assurance are defined, associated with uncertainty in the words ''credible' and ''demonstrable.'' Sound reasons exist for believing that inherent safety puts a modest upper bound on all accident consequences; it should be considered a part of the collection of safety and environmental issues, which also include lower consequence accidents, waste management, and effluent control

Developing a model for hospital inherent safety assessment: Conceptualization and validation.

Science.gov (United States)

Yari, Saeed; Akbari, Hesam; Gholami Fesharaki, Mohammad; Khosravizadeh, Omid; Ghasemi, Mohammad; Barsam, Yalda; Akbari, Hamed

2018-01-01

Paying attention to the safety of hospitals, as the most crucial institute for providing medical and health services wherein a bundle of facilities, equipment, and human resource exist, is of significant importance. The present research aims at developing a model for assessing hospitals' safety based on principles of inherent safety design. Face validity (30 experts), content validity (20 experts), construct validity (268 examples), convergent validity, and divergent validity have been employed to validate the prepared questionnaire; and the items analysis, the Cronbach's alpha test, ICC test (to measure reliability of the test), composite reliability coefficient have been used to measure primary reliability. The relationship between variables and factors has been confirmed at 0.05 significance level by conducting confirmatory factor analysis (CFA) and structural equations modeling (SEM) technique with the use of Smart-PLS. R-square and load factors values, which were higher than 0.67 and 0.300 respectively, indicated the strong fit. Moderation (0.970), simplification (0.959), substitution (0.943), and minimization (0.5008) have had the most weights in determining the inherent safety of hospital respectively. Moderation, simplification, and substitution, among the other dimensions, have more weight on the inherent safety, while minimization has the less weight, which could be due do its definition as to minimize the risk.

Measurement of glomerular filtration rate in the conscious rat.

Science.gov (United States)

Pestel, Sabine; Krzykalla, Volker; Weckesser, Gerhard

2007-01-01

Glomerular filtration rate (GFR) is an important parameter for studying drug-induced impairments on renal function in rats. The GFR is calculated from the concentration of creatinine and blood urea nitrogen (BUN) in serum and in urine, respectively. Following current protocols serum and urine samples must be taken from the same animal. Thus, in order to determine time-dependent effects it is necessary to use for each time point one separated group of animals. We developed a statistical test which allows analyzing the GFR from two different groups of animals: one used for repeated serum and the other one used for repeated urine analysis. Serum and urine samples were taken from two different sets of rats which were otherwise treated identically, i.e. drug doses, routes of administration (per os or per inhalation) and tap water loading. For each dose group GFR mean, standard deviation and statistical analysis to identify differences between the dose groups were determined. After determination of the optimal time points for measurements, the effect on GFR of the three reference compounds, furosemide, hydrochlorothiazide and formoterol, was calculated. The results showed that the diuretic drugs furosemide and hydrochlorothiazide decreased the GFR and the antidiuretic drug formoterol increased the GFR, as counter regulation on urine loss or urine retention, respectively. A mathematical model and the corresponding algorithm were developed, which can be used to calculate the GFR, and to test for differences between groups from two separated sets of rats, one used for urine, and the other one for serum analysis. This new method has the potential to reduce the number of animals needed and to improve the quality of data generated from various groups of animals in renal function studies.

Hanford underground storage tank waste filtration process evaluation

International Nuclear Information System (INIS)

Walker, B.W.; McCabe, D.J.

1997-01-01

The purpose of this filter study was to evaluate cross-flow filtration as effective solid-liquid separation technology for treating Hanford wastes, outline operating conditions for equipment, examine the expected filter flow rates, and determine proper cleaning. Two Hanford waste processing applications have been identified as candidates for the use of cross-flow filtration. The first of the Hanford applications involves filtration of the decanted supernate from sludge leaching and washing operations. This process involves the concentration and removal of dilute (0.05 wt percent) fines from the bulk of the supernate. The second application involves filtration to wash and concentrate the sludge during out-of-tank processing. This process employs a relatively concentrated (8 wt percent) solids feed stream. Filter studies were conducted with simulants to evaluate whether 0.5 micron cross-flow sintered metal Mott filters and 0.1 micron cross-flow Graver filters can perform solid-liquid separation of the solid/liquid waste streams effectively. In cross-flow filtration the fluid to be filtered flows in parallel to the membrane surface and generates shearing forces and/or turbulence across the filter medium. This shearing influences formation of filter cake stabilizing the filtrate flow rate

Spontaneous water filtration of bio-inspired membrane

Science.gov (United States)

Kim, Kiwoong; Kim, Hyejeong; Lee, Sang Joon

2016-11-01

Water is one of the most important elements for plants, because it is essential for various metabolic activities. Thus, water management systems of vascular plants, such as water collection and water filtration have been optimized through a long history. In this view point, bio-inspired technologies can be developed by mimicking the nature's strategies for the survival of the fittest. However, most of the underlying biophysical features of the optimized water management systems remain unsolved In this study, the biophysical characteristics of water filtration phenomena in the roots of mangrove are experimentally investigated. To understand water-filtration features of the mangrove, the morphological structures of its roots are analyzed. The electrokinetic properties of the root surface are also examined. Based on the quantitatively analyzed information, filtration of sodium ions in the roots are visualized. Motivated by this mechanism, spontaneous desalination mechanism in the root of mangrove is proposed by combining the electrokinetics and hydrodynamic transportation of ions. This study would be helpful for understanding the water-filtration mechanism of the roots of mangrove and developing a new bio-inspired desalination technology. This research was financially supported by the National Research Foundation (NRF) of Korea (Contract Grant Number: 2008-0061991).

Chest CT using spectral filtration: radiation dose, image quality, and spectrum of clinical utility

Energy Technology Data Exchange (ETDEWEB)

Braun, Franziska M.; Johnson, Thorsten R.C.; Sommer, Wieland H.; Thierfelder, Kolja M.; Meinel, Felix G. [University Hospital Munich, Institute for Clinical Radiology, Munich (Germany)

2015-06-01

To determine the radiation dose, image quality, and clinical utility of non-enhanced chest CT with spectral filtration. We retrospectively analysed 25 non-contrast chest CT examinations acquired with spectral filtration (tin-filtered Sn100 kVp spectrum) compared to 25 examinations acquired without spectral filtration (120 kV). Radiation metrics were compared. Image noise was measured. Contrast-to-noise-ratio (CNR) and figure-of-merit (FOM) were calculated. Diagnostic confidence for the assessment of various thoracic pathologies was rated by two independent readers. Effective chest diameters were comparable between groups (P = 0.613). In spectral filtration CT, median CTDI{sub vol}, DLP, and size-specific dose estimate (SSDE) were reduced (0.46 vs. 4.3 mGy, 16 vs. 141 mGy*cm, and 0.65 vs. 5.9 mGy, all P < 0.001). Spectral filtration CT had higher image noise (21.3 vs. 13.2 HU, P < 0.001) and lower CNR (47.2 vs. 75.3, P < 0.001), but was more dose-efficient (FOM 10,659 vs. 2,231/mSv, P < 0.001). Diagnostic confidence for parenchymal lung disease and osseous pathologies was lower with spectral filtration CT, but no significant difference was found for pleural pathologies, pulmonary nodules, or pneumonia. Non-contrast chest CT using spectral filtration appears to be sufficient for the assessment of a considerable spectrum of thoracic pathologies, while providing superior dose efficiency, allowing for substantial radiation dose reduction. (orig.)

Advanced lithographic filtration and contamination control for 14nm node and beyond semiconductor processes

Science.gov (United States)

Varanasi, Rao; Mesawich, Michael; Connor, Patrick; Johnson, Lawrence

2017-03-01

Two versions of a specific 2nm rated filter containing filtration medium and all other components produced from high density polyethylene (HDPE), one subjected to standard cleaning, the other to specialized ultra-cleaning, were evaluated in terms of their cleanliness characteristics, and also defectivity of wafers processed with photoresist filtered through each. With respect to inherent cleanliness, the ultraclean version exhibited a 70% reduction in total metal extractables and 90% reduction in organics extractables compared to the standard clean version. In terms of particulate cleanliness, the ultraclean version achieved stability of effluent particles 30nm and larger in about half the time required by the standard clean version, also exhibiting effluent levels at stability almost 90% lower. In evaluating defectivity of blanket wafers processed with photoresist filtered through either version, initial defect density while using the ultraclean version was about half that observed when the standard clean version was in service, with defectivity also falling more rapidly during subsequent usage of the ultraclean version compared to the standard clean version. Similar behavior was observed for patterned wafers, where the enhanced defect reduction was primarily of bridging defects. The filter evaluation and actual process-oriented results demonstrate the extreme value in using filtration designed possessing the optimal intrinsic characteristics, but with further improvements possible through enhanced cleaning processes

Efficient filtration system for paraffin-catalyst slurry separation

Directory of Open Access Journals (Sweden)

Khodagholi Mohammad Ali

2013-01-01

Full Text Available The filtration efficiency for separating liquid paraffin (or water from a slurry consisting of 25 weight% spherical alumina in a Slurry Bubble Column Reactor (SBCR comprised of a cylindrical tube of 10 cm diameter and 150 cm length was studied. Various differential pressures (ΔP were applied to two separate tubular sintered metal stainless steel filter elements with nominal pore size of 4 and 16μm. The experimental results disclosed that the rate of filtrations increased on applying higher differential pressure to the filter element. Albeit this phenomenon is limited to moderate ΔPs and for ΔP more than 1 bar is neither harmful nor helpful. The highest filtration rates at ΔPs higher than 1 bar were 170 and 248 ml/minute for 4 and 16μm respectively. Using water as the liquid in slurry the rate of filtration enhanced to 4 folds, and this issue reveals impact of viscosity on filtration efficiency clearly. In all situations, the total amount of particles present in the filtrate part never exceeded a few parts per million (ppm. The statistical analysis of the SEM image of the filtrate indicated that by applying higher pressure difference to the filter element the frequency percent of larger particle size increases. The operation of filter cake removing was performed with back flashing of 300 ml of clean liquid with pressures of 3-5 bar of N2 gas.

Quantitative measurement and visualization of biofilm O 2 consumption rates in membrane filtration systems

KAUST Repository

Prest, Emmanuelle I E C

2012-03-01

There is a strong need for techniques enabling direct assessment of biological activity of biofouling in membrane filtration systems. Here we present a new quantitative and non-destructive method for mapping O 2 dynamics in biofilms during biofouling studies in membrane fouling simulators (MFS). Transparent planar O 2 optodes in combination with a luminescence lifetime imaging system were used to map the two-dimensional distribution of O 2 concentrations and consumption rates inside the MFS. The O 2 distribution was indicative for biofilm development. Biofilm activity was characterized by imaging of O 2 consumption rates, where low and high activity areas could be clearly distinguished. The spatial development of O 2 consumption rates, flow channels and stagnant areas could be determined. This can be used for studies on concentration polarization, i.e. salt accumulation at the membrane surface resulting in increased salt passage and reduced water flux. The new optode-based O 2 imaging technique applied to MFS allows non-destructive and spatially resolved quantitative biological activity measurements (BAM) for on-site biofouling diagnosis and laboratory studies. The following set of complementary tools is now available to study development and control of biofouling in membrane systems: (i) MFS, (ii) sensitive pressure drop measurement, (iii) magnetic resonance imaging, (iv) numerical modelling, and (v) biological activity measurement based on O 2 imaging methodology. © 2011 Elsevier B.V.

SUSPENSION-FEEDING IN MARINE SPONGES HALICHONDRIA-PANICEA AND HALICLONA-URCEOLUS - EFFECTS OF TEMPERATURE ON FILTRATION-RATE AND ENERGY-COST OF PUMPING

DEFF Research Database (Denmark)

Riisgård, H.U.; Thomassen, S.; Jakobsen, H.

1993-01-01

Filtration rate (measured as clearance of algal cells) was measured at different temperatures in the sponge Halichondria panicea. An increase in water temperature from 6 to 12-degrees-C caused the mean filtration rate to increase 4.3 +/- 2.3 times. This value was higher than previously found...... for other marine ciliary suspension-feeding animals. Filtration rate at 12-degrees-C was also measured in Haliclona urceolus by means of an indirect clearance method in addition to a direct technique for measuring pumping rate. It was found that the 2 sponge species had near-identical filtration rates......, with maximum rates of approximately 60 ml min-1 (g dry weight)-1 at 12-degrees-C. The normal pump pressure, or operating point O(p), of a standard sponge (based on our own measurements and calculations from literature data for a 0.1 g dry weight Haliclona sp.) was estimated as the sum of main contributions...

40 CFR 141.717 - Pre-filtration treatment toolbox components.

Science.gov (United States)

2010-07-01

... surface water or GWUDI source. (c) Bank filtration. Systems receive Cryptosporidium treatment credit for... paragraph. Systems using bank filtration when they begin source water monitoring under § 141.701(a) must... 40 Protection of Environment 22 2010-07-01 2010-07-01 false Pre-filtration treatment toolbox...

Water filtration of the forearm in short- and long-term diabetes mellitus

DEFF Research Database (Denmark)

Poulsen, H L; Nielsen, S L

1976-01-01

of the forearm. Increased water filtration in connective tissue in long-term diabetics is in accordance with earlier findings of a lowered subcutaneous interstitial fluid albumin concentration in long-term diabetics, this being explained by an increase in net water outflux from the microcirculation.......Blood flow and capillary filtration coefficient (CFC) were measured by strain-gauge plethysmography on the upper and lower third of the forearm in 9 normal subjects and 29 well regulated patients with diabetes mellitus of varying duration (less than 10 years, 10 to 20 years, and more than 20 years...

Measurement of Murine Single-Kidney Glomerular Filtration Rate Using Dynamic Contrast-Enhanced MRI.

Science.gov (United States)

Jiang, Kai; Tang, Hui; Mishra, Prasanna K; Macura, Slobodan I; Lerman, Lilach O

2018-06-01

To develop and validate a method for measuring murine single-kidney glomerular filtration rate (GFR) using dynamic contrast-enhanced MRI (DCE-MRI). This prospective study was approved by the Institutional Animal Care and Use Committee. A fast longitudinal relaxation time (T 1 ) measurement method was implemented to capture gadolinium dynamics (1 s/scan), and a modified two-compartment model was developed to quantify GFR as well as renal perfusion using 16.4T MRI in mice 2 weeks after unilateral renal artery stenosis (RAS, n = 6) or sham (n = 8) surgeries. This approach was validated by comparing model-derived GFR and perfusion to those obtained by fluorescein isothiocyanante (FITC)-inulin clearance and arterial spin labeling (ASL), respectively, using the Pearson's and Spearman's rank correlations and Bland-Altman analysis. The compartmental model provided a good fitting to measured gadolinium dynamics in both normal and RAS kidneys. The proposed DCE-MRI method offered assessment of single-kidney GFR and perfusion, comparable to the FITC-inulin clearance (Pearson's correlation coefficient r = 0.95 and Spearman's correlation coefficient ρ = 0.94, P < 0.0001, and mean difference -7.0 ± 11.0 μL/min) and ASL (r = 0.92 and ρ = 0.84, P < 0.0001, and mean difference 4.4 ± 66.1 mL/100 g/min) methods. The proposed DCE-MRI method may be useful for reliable noninvasive measurements of single-kidney GFR and perfusion in mice. Magn Reson Med 79:2935-2943, 2018. © 2017 International Society for Magnetic Resonance in Medicine. © 2017 International Society for Magnetic Resonance in Medicine.

[Pollution prevention and control of aqueous extract of astragali radix processed with ZrO2 inorganic ceramic membrane micro-filtration].

Science.gov (United States)

Pan, Lin-Men; Huang, Min-Yan; Guo, Li-Wei

2012-11-01

To study the measures for preventing and controlling the pollution of aqueous extract of Astragali Radix proceeded with inorganic ceramic membrane micro-filtration, in order to find effective measures for preventing and controlling the membrane pollution. The resistance distribution, polymer removal and changes in physical and chemical parameters of the zirconium oxide film of different pore diameters were determined to analyze the state or location of pollutants as well as the regularity of formation. Meanwhile, recoil and ultrasonic physical measures were adopted to strengthen the membrane process, in order to explore the methods for preventing and controlling the membrane pollution. When 0.2 microm of ZrO2 micro-filtrated aqueous extract of Astragali Radix, the rate of pollution was as high as 44.9%. The hole blocking resistance and the concentration polarization resistance were the main filtration resistances, while the surface deposit resistance decreased with the increase in the membrane's hold diameter; after micro-filtration, the liquid turbidity significantly reduced, with slight changes in both pH and viscosity. The 0.2 microm ZrO2 micro-filtration membrane performed better than the 0.05 microm pore size membrane in terms of conductivity. The 0. 2 microm and 0.05 microm pore diameter membranes showed better performance in the removal of pectin. The ultrasonic measure to strengthen membranes is more suitable to this system, with a flux rate up by 41.7%. The membrane optimization process adopts appropriate measures for preventing and controlling the membrane pollution, in order to reduce the membrane pollution, recover membrane performance and increase filtration efficiency.

Transport of micropollutants in a riverbank filtration system

Science.gov (United States)

van Driezum, Inge; Oudega, Thomas; Reiner, Philipp; Zessner, Matthias; Farnleitner, Andreas; Blaschke, Paul

2014-05-01

Groundwater locations at alluvial backwaters are essential for public water supply. Riverbank filtration (RBF) systems are widely used as a means of obtaining public water supplies. Riverbank filtration is an effective way to remove micropollutants from the receiving surface water. The efficiency of the RBF system strongly depends on the residence time of the water in the aquifer and on the soil properties (Ray, 2011). In order to understand all bio- and geochemical processes within the hyporheic zone (e.g. the region were mixing of surface water and groundwater occurs), exchange rates and flow patterns need to be quantified. The main study area covers the porous groundwater aquifer study site (PGWA) - an urban floodplain extending on the left bank of the River Danube downstream of the City of Vienna. It is one of the main groundwater bodies in Austria. Groundwater quality in the PGWA is influenced by a combination of anthropogenic activities, industry, wastewater treatment plants, heavy precipitation events and floodings. The upper layer of the DPA is impermeable, preventing pollution originating from the surface. The upper layer consists of silt. The underlying confined aquifer consists of sand and gravel layers. Hydraulic conductivities range from 5 x 10-2 m/s up to 5 x 10-5 m/s. Underneath the aquifer are alternating sand an clay/silt layers. Samples are taken from two transects in the DPA. These transects consist of four piezometers in the first few meters of the groundwater aquifer. Several other piezometers are placed downstream from the river-groundwater interface. The behaviour of the micropollutants in the hyporheic zone can therefore be studied intensively. The transport behaviour of several micropollutants is modeled using carbamazepine (CBZ) and acesulfame (ACE) as natural tracers. Furthermore, temperature and electrical conductivity data was used for modeling. The micropollutants are measured using an in house developed online SPE-HPLC-MS/MS method

Dynamic optimization of dead-end membrane filtration

NARCIS (Netherlands)

Blankert, B.; Betlem, Bernardus H.L.; Roffel, B.; Marquardt, Wolfgang; Pantelides, Costas

2006-01-01

An operating strategy aimed at minimizing the energy consumption during the filtration phase of dead-end membrane filtration has been formulated. A method allowing fast calculation of trajectories is used to allow incorporation in a hierarchical optimization scheme. The optimal trajectory can be

Vowel Inherent Spectral Change

CERN Document Server

Assmann, Peter

2013-01-01

It has been traditional in phonetic research to characterize monophthongs using a set of static formant frequencies, i.e., formant frequencies taken from a single time-point in the vowel or averaged over the time-course of the vowel. However, over the last twenty years a growing body of research has demonstrated that, at least for a number of dialects of North American English, vowels which are traditionally described as monophthongs often have substantial spectral change. Vowel Inherent Spectral Change has been observed in speakers’ productions, and has also been found to have a substantial effect on listeners’ perception. In terms of acoustics, the traditional categorical distinction between monophthongs and diphthongs can be replaced by a gradient description of dynamic spectral patterns. This book includes chapters addressing various aspects of vowel inherent spectral change (VISC), including theoretical and experimental studies of the perceptually relevant aspects of VISC, the relationship between ar...

Cu filtration for dose reduction in neonatal chest imaging

International Nuclear Information System (INIS)

Smans, K.; Struelens, L.; Smet, M.; Bosmans, H.; Vanhavere, F.

2010-01-01

As neonatal chest images are frequently acquired to investigate the life-threatening lung diseases in prematurely born children, their optimisation in terms of X-ray exposure is required. The aim of this study was to investigate whether such dose-optimisation studies could be performed using a Monte Carlo computer model. More specifically, a Monte Carlo computer model was used to investigate the influence of Cu filtration on image quality and dose in neonatal chest imaging. Monte Carlo simulations were performed with the MCNPX code and used with voxel models representing prematurely born babies (590 and 1910 g). Physical image quality was derived from simulated images in terms of the signal difference-to-noise ratio and signal-to-noise ratio (SNR). To verify the simulation results, measurements were performed using the Gammex 610 Neonatal Chest Phantom, which represents a 1-2 kg neonate. A figure of merit was used to assist in evaluating the optimum balance between the image quality and the patient dose. The results show that the Monte Carlo computer model to investigate dose and image quality works well and can be used in dose-optimisation studies for real clinical practices. Furthermore, working at a specific constant incident air kerma (K a,I ), additional filtration proved to increase SNR with 30%, whereas working at a specific constant detector dose, extra Cu filtration reduces the lung dose with 25%. Optimum balance between patient dose and image quality is found to be 60 kVp (using extra filtration). (authors)

Filtration of droplets in the nose of the rabbit

Energy Technology Data Exchange (ETDEWEB)

Davies, C N

1946-01-01

Optical measurement was done on oil cloud sedimentation before and after passing through nose and out tracheal cannula. The filtering unit which also provides most resistance to flow is maximal turbinates. Nasal cavity is more complex than in man or some other animals, so filtration may be different. Calculation of particle inertia and filter channel width shows that particles > 7 ..mu..m would impact on curves or projections. Particles less than 1.5 ..mu..m should penetrate freely, but low molecular weight gases would be caught by diffusion. The higher the flow, the better the filtration (inertial settling). Broadly summarizing, at ordinary flow rates and nasal resistances, essentially all drops > 7 ..mu..m will be removed. About 50% of 3-..mu.. drops will be removed. < 1.5-..mu..m drops will penetrate.

Inherent Anticipation in the Pharmaceutical and Biotechnology Industries.

Science.gov (United States)

Goldman, Michael; Evans, Georgia; Zappia, Andrew

2015-04-15

Pharmaceutical and biotech research often involves discovering new properties of, or new methods to use, existing compositions. The doctrine of inherent anticipation, however, prevents the issuance and/or validity of a patent for discoveries deemed to have been implicitly disclosed in the prior art. This can be a barrier to patent rights in these technologies. Inherent anticipation therefore creates uncertainty for patent protection in the pharmaceutical and biotech sciences. Despite this uncertainty, Federal Circuit jurisprudence provides guidance on the boundaries of the inherent anticipation doctrine. In view of the case law, certain strategies may be employed to protect inventions that may potentially be viewed as inherent in the prior art. Copyright © 2015 Cold Spring Harbor Laboratory Press; all rights reserved.

Evaluating the effectiveness of heat-resistant cast steel filtration from the results of structure examinations

Directory of Open Access Journals (Sweden)

Asłanowicz M.

2007-01-01

Full Text Available Filtration guarantees castings characterised by high quality and free from any non-metallic inclusions, which are formed at the stage of melting and pouring of liquid metal. This article discusses the problem of the effectiveness of filtration process taking as an example heat-resistant cast steel poured into ceramic moulds. In investigations, foamed zircon filters made by FerroTerm Sp. z o.o. The effectiveness of filtration was described and examined using the results of metallographic examinations, including macro- and micro-structure examinations of metal and of cast metal/ceramic filter interface, and measurements of the content of non-metallic inclusions. The methods of investigations were presented, the obtained results were described, and relevant conclusions were drawn, all of them unmistakably indicating a very beneficial effect that filtration has on molten metal quality. Łódź, Poland, were used.

Organic iodide capture using a zeolite dry filtration

International Nuclear Information System (INIS)

Park, Sanggil; Sung, Joonyoung; Kim, Gi-ppeum; Lee, Jaeyoung

2017-01-01

An organic iodide, especially, methyl iodide (CH 3 I) would generated non-negligibly from a severe accident in a nuclear power plant. This CH 3 I will be dangerous for human when it was inhaled, it is highly toxic and causes a serious nerve disorder. Even it is a major contributor to a thyroid cancer. In order to prevent its environmental release, it is required to decontaminate using a filtration system. For the removal of CH 3 I from the release gases, wet-type is not ideal due to a high re-volatile characteristics of CH 3 I. It may become volatile after dissolving in a pool and forms CH 3 I again at the surface of water pool. Therefore, a dry-filtration should be installed to remove the CH 3 I. In this study, we preliminary investigate the characteristics of zeolite filtration methods for the removal of CH 3 I. We used both silver ion exchanged ZSM-5-zeolite (Ag+-ZSM-5) to study the effect of silver ion for the removal of iodine from CH 3 I. In summary, the CH 3 I capture tests using a silver ion exchanged zeolite was conducted in the coupled TGAGC test set-up. The mass change of the sample and concentration of CH 3 I were measured. The samples were investigated by the SEM/EDS to see its surface characteristics.

Filter aids influence on pressure drop across a filtration system

Science.gov (United States)

Hajar, S.; Rashid, M.; Nurnadia, A.; Ammar, M. R.; Hasfalina, C. M.

2017-06-01

Filter aids is commonly used to reduce pressure drop across air filtration system as it helps to increase the efficiency of filtration of accumulated filter cake. Filtration velocity is one of the main parameters that affect the performance of filter aids material. In this study, a formulated filter aids consisting of PreKot™ and activated carbon mixture (designated as PrekotAC) was tested on PTFE filter media under various filtration velocities of 5, 6, and 8 m/min at a constant material loading of 0.2 mg/mm2. Results showed that pressure drop is highly influenced by filtration velocity where higher filtration velocity leads to a higher pressure drop across the filter cake. It was found that PrekotAC performed better in terms of reducing the pressure drop across the filter cake even at the highest filtration velocity. The diversity in different particle size distribution of non-uniform particle size in the formulated PrekotAC mixture presents a higher permeability causes a lower pressure drop across the accumulated filter cake. The finding suggests that PrekotAC is a promising filter aids material that helps reducing the pressure drop across fabric filtration system.

Evaluation of Impact of Coagulant Type on Operation Parameters in Direct Filtration

Directory of Open Access Journals (Sweden)

Ali Torabian

2007-06-01

Full Text Available Numerous advantages have been reported on PAC (poly aluminum chloride used as a coagulant over other coagulants such as alum and ferric chloride used in conventional water treatment process with medium and high turbidity levels. These include lower amounts of PACL required specially in removing turbidity, larger floc grain formation, reduced floc sedimentation time, lower sludge production, and relaxation of the need for pH adjustment by lime, among others. The present study aims to evaluate the effects of different coagulants such as ferric chloride and PACL on direct filtration and to identify the most effective material based on both turbidity and particle removal efficiencies. A perfectly experimental pilot system, including raw water preparation, coagulation, flocculation, distribution measurement, and filtration units, was designed and used. Raw water turbidity level in the experimental pilot was below 10 NTU. The effects of various parameters such as coagulant type, filtration rate, and coagulant dosage on the performance of the filter were investigated. The results obtained from several filtration cycles under different conditions indicated that average effluent turbidity level, effluent particle numbers, effluent turbidity variation graph, and effluent particle graph were lower throughout the filtration cycle when PACL was used compared to when ferric chloride was used as the coagulant. Increasing filtration rate led to increased turbidity and particle number. Addition of 2 mg/l of PACL (poor coagulation and flocculation scenario was compared with addition of 5 mg/l of ferric chloride (strong coagulation and flocculation scenario. The results indicated that higher average values of turbidity removal but lower turbidity and particle removal efficiencies obtained in the case of the poor coagulation and flocculation scenario.

Inherently safe high temperature gas-cooled reactor

International Nuclear Information System (INIS)

Yamada, Masao; Hayakawa, Hitoshi

1987-01-01

It is recognized in general that High Temperature Gas-cooled Reactors have remarkable characteristics in inherent safety and it is well known that credits of the time margin have been admitted for accident evaluation in the licensing of the currently operating prototype HTGRs (300 MWe class). Recently, more inherently safe HTGRs are being developed in various countries and drawing attention on their possibility for urban siting. The inherent safety characteristics of these HTRs differ each other depending on their design philosophy and on the features of the components/structures which constitute the plant. At first, the specific features/characteristics of the elemental components/structures of the HTRs are explained one by one and then the overall safety features/characteristics of these HTR plants are explained in connection with their design philosophy and combination of the elemental features. Taking the KWU/Interatom Modular Reactor System as an example, the particular design philosophy and safety characteristics of the inherently safe HTR are explained with a result of preliminary evaluation on the possibility of siting close to densely populated area. (author)

Transcutaneous measurement of glomerular filtration rate in small rodents: through the skin for the win?

Science.gov (United States)

Ellery, Stacey J; Cai, Xiaochu; Walker, David D; Dickinson, Hayley; Kett, Michelle M

2015-03-01

Rodent models of renal physiology and pathology are crucial to our understanding of the molecular, histological and functional sequelae that contribute to kidney diseases. One of the most important measures of renal function is glomerular filtration rate (GFR). While the accurate determination of GFR is pivotal to understanding the progression of disease and/or the benefits of treatment strategies, in rodents the conventional methods for assessment of GFR are inconvenient and cumbersome, not the least because they involve stress and often anaesthesia. The legitimacy of assay-based assessment of plasma and urine markers of GFR in mice has also been heavily scrutinized for their insensitivity to minor declines in GFR and inaccurate detection of renal biomarkers. While infusion-based clearance methods of GFR assessment are thus the gold standard in terms of accuracy, they are limited by the fact that they are primarily non-recovery procedures. This presents a dilemma when trying to document the progression of renal disease, as these measures cannot be taken in the same experimental subject. Here we review a technique of transcutaneous measurement of fluorescein isothiocyanate-labelled sinistrin to calculate GFR in small rodents, using a non-invasive clearance device (NIC-Kidney Device). This is a recently validated non-invasive technique for measuring GFR in small rodents that allows for the real-time measurement of GFR in conscious animals, without the need for plasma and urine assays. © 2014 Asian Pacific Society of Nephrology.

Can the inherence heuristic explain vitalistic reasoning?

Science.gov (United States)

Bastian, Brock

2014-10-01

Inherence is an important component of psychological essentialism. By drawing on vitalism as a way in which to explain this link, however, the authors appear to conflate causal explanations based on fixed features with those based on general causal forces. The disjuncture between these two types of explanatory principles highlights potential new avenues for the inherence heuristic.

Development of physiotherapy inherent requirement statements - an Australian experience.

Science.gov (United States)

Bialocerkowski, Andrea; Johnson, Amanda; Allan, Trevor; Phillips, Kirrilee

2013-04-16

The United Nations Convention on the Rights of People with Disabilities promotes equal rights of people with a disability in all aspects of their life including their education. In Australia, Disability Discrimination legislation underpins this Convention. It mandates that higher education providers must demonstrate that no discrimination has occurred and all reasonable accommodations have been considered and implemented, to facilitate access and inclusion for a student with a disability. The first step to meeting legislative requirements is to provide students with information on the inherent requirements of a course. This paper describes the steps which were taken to develop inherent requirement statements for a 4-year entry-level physiotherapy program at one Australian university. Inherent requirement statements were developed using an existing framework, which was endorsed and mandated by the University. Items which described inherencies were extracted from Australian physiotherapy professional standards and statutory regulatory requirements, and units contained in the physiotherapy program. Data were integrated into the 8 prescribed domains: ethical behaviour, behavioural stability, legal, communication, cognition, sensory abilities, strength and mobility, and sustainable performance. Statements for each domain were developed using a 5-level framework (introductory statement, description of the inherent requirement, justification for inherency, characteristics of reasonable adjustments and exemplars) and reviewed by a University Review Panel. Refinement of statements continued until no further changes were required. Fifteen physiotherapy inherent requirement statements were developed. The eight domains identified in the existing framework, developed for Nursing, were relevant to the study of physiotherapy. The inherent requirement statements developed in this study provide a transparent, defensible position on the current requirements of physiotherapy study at

In-Water Hull Cleaning & Filtration System

Science.gov (United States)

George, Dan

2015-04-01

through a multi stage filtration unit on the surface. Solids greater than 50 micron are separated through a 1st stage separator and deposited into a disposal bin. Filtrate is then pumped through a series of high flow, back-flushable filters that remove particulate material greater than 5 micron. After the 1st and 2nd stage filtration the filtrate is then disinfected by passing through an automated UV reactor where the treated water is then released back into the ocean. This advancement in hull cleaning technology will allow vessels to be cleaned in areas where dry docking is not possible or viable along with being a preventive measure to reduce Biofouling in the environment. The in-water hull cleaning system certainly has earned its place as being an innovative leader in improving efficiencies and reducing environmental impact. https://www.linkedin.com/groups?mostRecent=&gid=6724648&trk=my_groups-tile-flipgrp

Life Support Filtration System Trade Study for Deep Space Missions

Science.gov (United States)

Agui, Juan H.; Perry, Jay L.

2017-01-01

The National Aeronautics and Space Administrations (NASA) technical developments for highly reliable life support systems aim to maximize the viability of long duration deep space missions. Among the life support system functions, airborne particulate matter filtration is a significant driver of launch mass because of the large geometry required to provide adequate filtration performance and because of the number of replacement filters needed to a sustain a mission. A trade analysis incorporating various launch, operational and maintenance parameters was conducted to investigate the trade-offs between the various particulate matter filtration configurations. In addition to typical launch parameters such as mass, volume and power, the amount of crew time dedicated to system maintenance becomes an increasingly crucial factor for long duration missions. The trade analysis evaluated these parameters for conventional particulate matter filtration technologies and a new multi-stage particulate matter filtration system under development by NASAs Glenn Research Center. The multi-stage filtration system features modular components that allow for physical configuration flexibility. Specifically, the filtration system components can be configured in distributed, centralized, and hybrid physical layouts that can result in considerable mass savings compared to conventional particulate matter filtration technologies. The trade analysis results are presented and implications for future transit and surface missions are discussed.

MHTGR inherent heat transfer capability

International Nuclear Information System (INIS)

Berkoe, J.M.

1992-01-01

This paper reports on the Commercial Modular High Temperature Gas-Cooled Reactor (MHTGR) which achieves improved reactor safety performance and reliability by utilizing a completely passive natural convection cooling system called the RCCS to remove decay heat in the event that all active cooling systems fail to operate. For the highly improbable condition that the RCCS were to become non-functional following a reactor depressurization event, the plant would be forced to rely upon its inherent thermo-physical characteristics to reject decay heat to the surrounding earth and ambient environment. A computational heat transfer model was created to simulate such a scenario. Plant component temperature histories were computed over a period of 20 days into the event. The results clearly demonstrate the capability of the MHTGR to maintain core integrity and provide substantial lead time for taking corrective measures

Dynamic optimization of a dead-end filtration trajectory: Blocking filtration laws

NARCIS (Netherlands)

Blankert, B.; Betlem, Bernardus H.L.; Roffel, B.

2006-01-01

An operating model for dead-end membrane filtration is proposed based on the well-known blocking laws. The resulting model contains three parameters representing, the operating strategy, the fouling mechanism and the fouling potential of the feed. The optimal control strategy is determined by

Mitigation of radon and thoron decay products by filtration

International Nuclear Information System (INIS)

Wang Jin; Meisenberg, Oliver; Chen Yongheng; Karg, Erwin; Tschiersch, Jochen

2011-01-01

Inhalation of indoor radon ( 222 Rn) and thoron ( 220 Rn) decay products is the most important source of exposure to ionizing radiation for the human respiratory tract. Decreasing ventilation rates due to energy saving reasons in new buildings suggest additional active mitigation techniques to reduce the exposure in homes with high radon and thoron concentrations but poor ventilation. Filtration techniques with HEPA filters and simple surgical mask material have been tested for their potential to reduce the indoor exposure in terms of the total effective dose for mixed radon and thoron indoor atmospheres. The tests were performed inside an experimental room providing stable conditions. Filtration (at filtration rates of 0.2 h -1 and larger) removes attached radon and thoron decay products effectively but indoor aerosol as well. Therefore the concentration of unattached decay products (which have a higher dose coefficient) may increase. The decrease of the attached decay product concentrations could be theoretically described by a slowly decreasing exponential process. For attached radon decay products, it exhibited a faster but weaker removal process compared to attached thoron decay products (- 70% for attached radon decay products and - 80% for attached thoron decay products at a filtration rate of 0.5 h -1 with an HEPA filter). The concentration of unattached thoron decay products increased distinctly during the filtration process (+ 300%) while that of unattached radon decay products rose only slightly though at a much higher level (+ 17%). In the theoretical description these observed differences could be attributed to the different half-lives of the nuclides. Considering both effects, reduced attached and increased unattached decay product concentrations, filtration could significantly decrease the total effective dose from thoron whereas the overall effect on radon dose is small. A permanent filtration is recommended because of the slow decrease of the

A study of dynamic filtration; Um estudo sobre filtracao dinamica

Energy Technology Data Exchange (ETDEWEB)

Girao, Joaquim Helder S [PETROBRAS, Natal, RN (Brazil). Distrito de Perfuracao da Bacia Potiguar. Div. de Tecnicas de Perfuracao

1990-12-31

The problems that cause cost increase such as: formation damage and borehole swelling or caving lead us to study the filtration of the liquid part of formation drilling fluid. With the aim of comparing static and dynamic filtration rates, we developed a modest dynamic filtration equipment, consisting of a modified API filter, connected to reservoir by means of a positive injection pump. We carried out various tests, and the results were set in charts and tables. Through these, it is possible to notice how the static and dynamic filtration curves come apart for a same pressure value. We also evaluated the effects of circulation speed, starch concentration and counter pressure. This paper does not include calculations or mathematical models accounting for filtrate invasion radii, but it demonstrates, for example, that cleaning circulation will cause lower filtration rates at lower flows. (author) 5 refs., 11 figs., 14 tabs.

A study of dynamic filtration; Um estudo sobre filtracao dinamica

Energy Technology Data Exchange (ETDEWEB)

Girao, Joaquim Helder S. [PETROBRAS, Natal, RN (Brazil). Distrito de Perfuracao da Bacia Potiguar. Div. de Tecnicas de Perfuracao

1989-12-31

The problems that cause cost increase such as: formation damage and borehole swelling or caving lead us to study the filtration of the liquid part of formation drilling fluid. With the aim of comparing static and dynamic filtration rates, we developed a modest dynamic filtration equipment, consisting of a modified API filter, connected to reservoir by means of a positive injection pump. We carried out various tests, and the results were set in charts and tables. Through these, it is possible to notice how the static and dynamic filtration curves come apart for a same pressure value. We also evaluated the effects of circulation speed, starch concentration and counter pressure. This paper does not include calculations or mathematical models accounting for filtrate invasion radii, but it demonstrates, for example, that cleaning circulation will cause lower filtration rates at lower flows. (author) 5 refs., 11 figs., 14 tabs.

Prediction of the filtrate particle size distribution from the pore size distribution in membrane filtration: Numerical correlations from computer simulations

Science.gov (United States)

Marrufo-Hernández, Norma Alejandra; Hernández-Guerrero, Maribel; Nápoles-Duarte, José Manuel; Palomares-Báez, Juan Pedro; Chávez-Rojo, Marco Antonio

2018-03-01

We present a computational model that describes the diffusion of a hard spheres colloidal fluid through a membrane. The membrane matrix is modeled as a series of flat parallel planes with circular pores of different sizes and random spatial distribution. This model was employed to determine how the size distribution of the colloidal filtrate depends on the size distributions of both, the particles in the feed and the pores of the membrane, as well as to describe the filtration kinetics. A Brownian dynamics simulation study considering normal distributions was developed in order to determine empirical correlations between the parameters that characterize these distributions. The model can also be extended to other distributions such as log-normal. This study could, therefore, facilitate the selection of membranes for industrial or scientific filtration processes once the size distribution of the feed is known and the expected characteristics in the filtrate have been defined.

Growth of mussels Mytilus edulis at algal (Rhodomonas salina) concentrations below and above saturation level for reduced filtration rate

DEFF Research Database (Denmark)

Riisgård, Hans Ulrik; Pleissner, Daniel; Larsen, Poul Scheel

2013-01-01

Average filtration and growth rates of groups of juvenile Mytilus edulis (n =2545 of 22-35 mm shell length) were measured at different concentrations of an algal cell monoculture in 9 laboratory experiments of duration 14-30 days, 4 experiments below and 5 above the limit of incipient saturation...... concentration (Csat ≈ 6000-7000 Rhodomonas salina cells ml-1). From a nearly constant filtration rate (F ≈ 30 ml min-1 for a 30 mm shell length) at measured algal concentrations below Csat the steady-state filtration rate decreased approximately as 1/C for increasing algal concentrations (C) above Csat...... is exceeded and then as partial valve closure and reduced filtration and growth rates along with production of pseudofaeces. A survey of naturally occurring phytoplankton biomass in the sea shows that this is generally below Csat except for the short spring bloom periods; hence mussels generally feed...

Cost-competitive, inherently safe LFMBR pool plant

International Nuclear Information System (INIS)

McDonald, J.S.; Brunings, J.E.; Chang, Y.I.; Hren, R.R.; Seidensticker, R.W.

1984-01-01

The Cost-Competitive, Inherently Safe LMFBR Pool Plant design was prepared in GFY 1983 under a DOE-sponsored program. This plant design was developed as a joint effort by Rockwell International and the Argonne National Laboratory with major contributions from the Bechtel Group, Inc.; Combustion engineering, Inc.; the Chicago Bridge and Iron Company; and the General Electric Company. Using current LMFBR technology, many innovative features were developed and incorporated into the design to meet the ultimate objectives of the Breeder Program, i.e., energy costs competitive with LWRs and inherent safety features to maintain the plant in a safe condition following assumed accidents without requiring operator action. This paper provides a description of the principal features that were incorporated into the design to achieve low cost and inherent safety

Filtration and retention capacities of filter aids

International Nuclear Information System (INIS)

Mellah, A.; Boualia, A.

1992-01-01

The present work involves the filtration of impure uranyl nitrate solutions by different filter aids such as kieselguhr, celite and bleaching clay. The retention of substances contained in uranyl nitrate solution was determined using the three filter aids. A study of the effects of granulometry and filter earths treatment (thermal and chemical) on the filtration rate was performed

SU-F-I-76: Fluoroscopic X-Ray Beam Profiles for Spectra Incorporating Copper Filtration

Energy Technology Data Exchange (ETDEWEB)

Wunderle, K [Cleveland Clinic Foundation, Cleveland, OH (United States); Wayne State University School of Medicine, Detroit, MI (United States); Godley, A; Shen, Z; Dong, F [Cleveland Clinic Foundation, Cleveland, OH (United States); Rakowski, J [Wayne State University School of Medicine, Detroit, MI (United States)

2016-06-15

Purpose: The purpose of this investigation is to characterize and quantify X-ray beam profiles for fluoroscopic x-ray beam spectra incorporating spectral (copper) filtration. Methods: A PTW (Freiburg, Germany) type 60016 silicon diode detector and PTW MP3 water tank were used to measure X-ray beam profiles for 60, 80, 100 and 120 kVp x-ray beams at five different copper filtration thicknesses ranging from 0–0.9 mm at 22 and 42 cm fields of view and depths of 1, 5, and 10 cm in both the anode-cathode axis (inplane) and cross-plane directions. All measurements were acquired on a Siemens (Erlangen, Germany) Artis ZeeGo fluoroscope inverted from the typical orientation providing an x-ray beam originating from above the water surface with the water level set at 60 cm from the focal spot. Results: X-ray beam profiles for beam spectra without copper filtration compared well to previously published data by Fetterly et al. [Med Phys, 28, 205 (2001)]. Our data collection benefited from the geometric orientation of the fluoroscope, providing a beam perpendicular to the tank water surface, rather than through a thin side wall as did the previously mentioned study. Profiles for beams with copper filtration were obtained which have not been previously investigated and published. Beam profiles in the anode-cathode axis near the surface and at lower x-ray energy exhibited substantial heel effect, which became less pronounced at greater depth. At higher energy with copper filtration in the beam, the dose falloff out-of-field became less pronounced, as would be anticipated given higher scatter photon energy. Conclusion: The x-ray beam profile data for the fluoroscopic x-ray beams incorporating copper filtration are intended for use as reference data for estimating doses to organs or soft tissue, including fetal dose, involving similar beam qualities or for comparison with mathematical models.

40 CFR 141.171 - Criteria for avoiding filtration.

Science.gov (United States)

2010-07-01

... 40 Protection of Environment 22 2010-07-01 2010-07-01 false Criteria for avoiding filtration. 141.171 Section 141.171 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) WATER PROGRAMS (CONTINUED) NATIONAL PRIMARY DRINKING WATER REGULATIONS Enhanced Filtration and Disinfection...

Vibrating membrane filtration as improved technology for microalgae dewatering

OpenAIRE

Nurra, C.; Clavero, E.; Salvadó, J.; Torras, C.

2014-01-01

10.1016/j.biortech.2014.01.115 The effect of shear-enhanced filtration by vibratory process in microalgae dewatering is presented in this paper. The aim of this research was to investigate the technical performance and improvement of vibrating membrane filtration compared with conventional tangential cross-flow filtration in microalgae concentration. An industrial-scale available commercial set-up was used. Several membrane materials as polyethersulfone, polyacrylonitrile, etc., and mean ...

Scaling and particulate fouling in membrane filtration systems

NARCIS (Netherlands)

Boerlage, S.F.E.

2001-01-01

In the last decade, pressure driven membrane filtration processes; reverse osmosis, nano, ultra and micro-filtration have undergone steady growth. Drivers for this growth include desalination to combat water scarcity and the removal of various material from water to comply with increasingly

Vacuum distillation/vapor filtration water recovery

Science.gov (United States)

Honegger, R. J.; Neveril, R. B.; Remus, G. A.

1974-01-01

The development and evaluation of a vacuum distillation/vapor filtration (VD/VF) water recovery system are considered. As a functional model, the system converts urine and condensates waste water from six men to potable water on a steady-state basis. The system is designed for 180-day operating durations and for function on the ground, on zero-g aircraft, and in orbit. Preparatory tasks are summarized for conducting low gravity tests of a vacuum distillation/vapor filtration system for recovering water from urine.

Industrial Application of Open Pore Ceramic Foam for Molten Metal Filtration

Science.gov (United States)

Gauckler, L. J.; Waeber, M. M.; Conti, C.; Jacob-Dulière, M.

Ceramic foam filters were used for industrial filtration of aluminum. Results are compared with laboratory experiments which are in good agreement with trajectory analyses of deep bed filtration for the early stage of filtration.

Transparent Nanofibrous Mesh Self-Assembled from Molecular LEGOs for High Efficiency Air Filtration with New Functionalities.

Science.gov (United States)

Singh, Varun Kumar; Ravi, Sai Kishore; Sun, Wanxin; Tan, Swee Ching

2017-02-01

Alarming levels of particulate matter pollution in air pose a serious health threat in several countries, therefore intriguing a strong need for an economic and a viable technology of air filtration. Current air purification technology is rather expensive with certain types even having the risk of emitting hazardous by-products. The authors have developed a multifunctional air filter inspired from the nasal hairs possessing an ability to specifically trap/exhale the foreign particles and allergens while still letting the air flow. This design is achieved by introducing different functionalities at different dimensional scale employing a bottom-up approach starting with an organic molecule which is further self-organized to form nanoparticles and ultimately to a nanofibrous mesh. While the molecular building block inherently possesses the property of shielding Ultraviolet (UV) rays, the nanofibrous mesh built up from it aids in trapping the particulate matter while maintaining good air flow. By controlling the concentration of the organic molecule, the formation of fibers has been enabled in the nanoscale regime to obtain high particle-capture possibilities. The self-assembled nanofibrous filter thus designed has achieved a high filtration efficiency of ≈90% for the PM 2.5 particle in congruence with the ability to block the harmful UV radiations. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Renal Blood Flow, Glomerular Filtration Rate, and Renal Oxygenation in Early Clinical Septic Shock.

Science.gov (United States)

Skytte Larsson, Jenny; Krumbholz, Vitus; Enskog, Anders; Bragadottir, Gudrun; Redfors, Bengt; Ricksten, Sven-Erik

2018-06-01

Data on renal hemodynamics, function, and oxygenation in early clinical septic shock are lacking. We therefore measured renal blood flow, glomerular filtration rate, renal oxygen consumption, and oxygenation in patients with early septic shock. Prospective comparative study. General and cardiothoracic ICUs. Patients with norepinephrine-dependent early septic shock (n = 8) were studied within 24 hours after arrival in the ICU and compared with postcardiac surgery patients without acute kidney injury (comparator group, n = 58). None. Data on systemic hemodynamics and renal variables were obtained during two 30-minute periods. Renal blood flow was measured by the infusion clearance of para-aminohippuric acid, corrected for renal extraction of para-aminohippuric acid. Renal filtration fraction was measured by renal extraction of chromium-51 labeled EDTA. Renal oxygenation was estimated from renal oxygen extraction. Renal oxygen delivery (-24%; p = 0.037) and the renal blood flow-to-cardiac index ratio (-21%; p = 0.018) were lower, renal vascular resistance was higher (26%; p = 0.027), whereas renal blood flow tended to be lower (-19%; p = 0.068) in the septic group. Glomerular filtration rate (-32%; p = 0.006) and renal sodium reabsorption (-29%; p = 0.014) were both lower in the septic group. Neither renal filtration fraction nor renal oxygen consumption differed significantly between groups. Renal oxygen extraction was significantly higher in the septic group (28%; p = 0.022). In the septic group, markers of tubular injury were elevated. In early clinical septic shock, renal function was lower, which was accompanied by renal vasoconstriction, a lower renal oxygen delivery, impaired renal oxygenation, and tubular sodium reabsorption at a high oxygen cost compared with controls.

Concept of an inherently-safe high temperature gas-cooled reactor

International Nuclear Information System (INIS)

Ohashi, Hirofumi; Sato, Hiroyuki; Tachibana, Yukio; Kunitomi, Kazuhiko; Ogawa, Masuro

2012-01-01

As the challenge to ensure no harmful release of radioactive materials at the accidents by deterministic approach instead to satisfy acceptance criteria or safety goal for risk by probabilistic approach, new concept of advanced reactor, an inherently-safe high temperature gas-cooled reactor, is proposed based on the experience of the operation of the actual High Temperature Gas-cooled Reactor (HTGR) in Japan, High Temperature Engineering Test Reactor (HTTR), and the design of the commercial plant (GTHTR300), utilizing the inherent safety features of the HTGR (i.e., safety features based on physical phenomena). The safety design philosophy of the inherently-safe HTGR for the safety analysis of the radiological consequences is determined as the confinement of radioactive materials is assured by only inherent safety features without engineered safety features, AC power or prompt actions by plant personnel if the design extension conditions occur. Inherent safety features to prevent the loss or degradation of the confinement function are identified. It is proposed not to apply the probabilistic approach for the evaluation of the radiological consequences of the accidents in the safety analysis because no inherent safety features fail for the mitigation of the consequences of the accidents. Consequently, there are no event sequences to harmful release of radioactive materials if the design extension conditions occur in the inherently-safe HTGR concept. The concept and future R and D items for the inherently-safe HTGR are described in this paper.

Dynamic optimization of a dead-end filtration trajectory: non-ideal cake filtration

NARCIS (Netherlands)

Blankert, B.; Kattenbelt, C.; Betlem, Bernardus H.L.; Roffel, B.

2007-01-01

A control strategy aimed at minimizing energy consumption is formulated for non-ideal dead-end cake filtration with an inside-out hollow fiber ultrafiltration membrane system. The non-ideal behavior was assumed to originate from cake compression, non-linear cake resistance and a variable pump

Licensing issues for inherently safe fast reactors

International Nuclear Information System (INIS)

Kastenberg, W.E.; Lee, S.; Okrent, D.

1986-01-01

There has been considerable interest recently in a new generation of liquid metal reactor (LMR) concepts in the US. Some significant changes in regulatory philosophy will be required if the anticipated cost advantages of inherently safe designs are to be achieved. The defense in depth philosophy will need to be significantly re-evaluated in the context of inherently safe reactors. It is the purpose of this paper to begin such a re-evaluation of this regulatory philosophy

Implications of inherent safe nuclear power system

International Nuclear Information System (INIS)

Song, Yo-Taik

1987-01-01

The safety of present day nuclear power reactors and research reactors depends on a combination of design features of passive and active systems, and the alert judgement of their operators. A few inherently safe designs of nuclear reactors for power plants are currently under development. In these designs, the passive systems are emphasized, and the active systems are minimized. Also efforts are made to eliminate the potential for human failures that initiate the series of accidents. If a major system fails in these designs, the core is flooded automatically with coolants that flow by gravity, not by mechanical pumps or electromagnetic actuators. Depending on the choice of the coolants--water, liquid metal and helium gas--there are three principal types of inherently safe reactors. In this paper, these inherently safe reactor designs are reviewed and their implications are discussed. Further, future perspectives of their acceptance by nuclear industries are discussed. (author)

Self Cleaning HEPA Filtration without Interrupting Process Flow

International Nuclear Information System (INIS)

Wylde, M.

2009-01-01

The strategy of protecting the traditional glass fibre HEPA filtration train from it's blinding contamination and the recovery of dust by the means of self cleaning, pre-filtration is a proven means in the reduction of ultimate disposal volumes and has been used within the Fuel Production Industry. However, there is an increasing demand in nuclear applications requiring elevated operating temperatures, fire resistance, moisture resistance and chemical composition that the existing glass fibre HEPA filtration cannot accommodate, which can be remedied by the use of a metallic HEPA filter media. Previous research (Bergman et al 1997, Moore et al 1992) suggests that the then costs to the DOE, based on a five year life cycle, was $29.5 million for the installation, testing, removal and disposal of glass fibre HEPA filtration trains. Within these costs, $300 was the value given to the filter and $4,450 was given to the peripheral activity. Development of a low cost, cleanable, metallic, direct replacement of the traditional filter train will the clear solution. The Bergman et al work has suggested that a 1000 ft 3 /min, cleanable, stainless HEPA could be commercially available for $5,000 each, whereas the industry has determined that the truer cost of such an item in isolation would be closer to $15,000. This results in a conflict within the requirement between 'low cost' and 'stainless HEPA'. By proposing a system that combines metallic HEPA filtration with the ability to self clean without interrupting the process flow, the need for a tradition HEPA filtration train will be eliminated and this dramatically reduces the resources required for cleaning or disposal, thus presenting a route to reducing ultimate costs. The paper will examine the performance characteristics, filtration efficiency, flow verses differential pressure and cleanability of a self cleaning HEPA grade sintered metal filter element, together with data to prove the contention. (authors)

Functional principal component analysis of glomerular filtration rate curves after kidney transplant.

Science.gov (United States)

Dong, Jianghu J; Wang, Liangliang; Gill, Jagbir; Cao, Jiguo

2017-01-01

This article is motivated by some longitudinal clinical data of kidney transplant recipients, where kidney function progression is recorded as the estimated glomerular filtration rates at multiple time points post kidney transplantation. We propose to use the functional principal component analysis method to explore the major source of variations of glomerular filtration rate curves. We find that the estimated functional principal component scores can be used to cluster glomerular filtration rate curves. Ordering functional principal component scores can detect abnormal glomerular filtration rate curves. Finally, functional principal component analysis can effectively estimate missing glomerular filtration rate values and predict future glomerular filtration rate values.

CALCULATION OF LONG-TERM FILTRATION IN A POROUS MEDIUM

Directory of Open Access Journals (Sweden)

Ludmila I. Kuzmina

2018-03-01

Full Text Available he filtration problem in a porous medium is an important part of underground hydromechanics. Filtration of suspensions and colloids determines the processes of strengthening the soil and creating waterproof walls in the ground while building the foundations of buildings and underground structures. It is assumed that the formation of a deposit is dominated by the size-exclusion mechanism of pore blocking: solid particles pass freely through large pores and get stuck at the inlet of pores smaller than the diameter of the particles. A one-dimensional mathematical model for the filtration of a monodisperse suspension includes the equation for the mass balance of suspended and retained particles and the kinetic equation for the growth of the deposit. For the blocking filtration coefficient with a double root, the exact solution is given implicitly. The asymptotics of the filtration problem is constructed for large time. The numerical calculation of the problem is carried out by the finite differences method. It is shown that asymptotic approximations rapidly converge to a solution with the increase of the expansion order.

Evaluation of multistage filtration to reduce sand filter exhaust activity

International Nuclear Information System (INIS)

Zippler, D.B.

1975-01-01

Air from the Savannah River Plant Fuel Reprocessing facilities is filtered through deep bed sand filters consisting of 8 1 / 2 feet of gravel and sand. These filters have performed satisfactorily for the past 18 years in maintaining radioactive release levels to a minimum. The apparent filter efficiency has been determined for many years by measurements of the quantity of radioactivity in the air stream before and after the filter. Such tests have indicated efficiencies of 99.9 percent or better. Even with sand filter efficiency approaching a single stage HEPA filter, new emphasis on further reduction in release of plutonium activity to the environment prompted a study to determine what value backup HEPA filtration could provide. To evaluate the specific effect additional HEPA filtration would have on the removal of Pu from the existing sand filter exhaust stream, a test was conducted by passing a sidestream of sand-filtered air through a standard 24 x 24 x 11 1 / 2 in. HEPA filter. Isokinetic air samples were withdrawn upstream and downstream of the HEPA filter and counted for alpha activity. Efficiency calculations indicated that backup HEPA filtration could be expected to provide an additional 99 percent removal of the Pu activity from the present sand-filter exhaust. (U.S.)

Basis, evidences and consequences of the inherent stellar encocooning

CERN Document Server

Celis, L

2002-01-01

Based on 7093 observations with photoelectrical photometrical measurements of 191 Mira stars, the following equations (from the papers [1] to [18]) give the basis to establish the Inherent Stellar Encocooning with the spectro-photometric characteristics of the red giant variable stars, especially the Miras, which have large amplitudes (approx 50% of giant variables). The specific basis that justifies a progressive covering with ionized molecules, cold gases, dust and grains are: The relation of the visual amplitudes A sub v =A sub r +E sub A whose real luminosity separate the intrinsic pulsation and amplitude excess effects due to the presence of molecules [145] and an opaque envelope of cool gases; The relation of the visual absolute magnitudes M sub v =M sub v sub r (P)+M sub a (delta sub T sub i sub O V) which is affected by an inherent absorption and/or occultation, and; The relation that defines the probable absolute luminosity and depends on the period and the (Sa) spectral type at maximum M sub v =-2.2...

Hydrophilicity improvement in polyphenylsulfone nanofibrous filtration membranes through addition of polyethylene glycol

Science.gov (United States)

Kiani, Shirin; Mousavi, Seyed Mahmoud; Shahtahmassebi, Nasser; Saljoughi, Ehsan

2015-12-01

Novel hydrophilic polyphenylsulfone (PPSU) nanofibrous membrane was prepared by electrospinning of the PPSU solution blended with polyethylene glycol 400 (PEG 400). The influence of the PEG concentration on the membrane characteristics was studied using scanning electron microscopy (SEM), water contact angle measurement, and tensile test. Filtration performance of the membranes was investigated by measurement of pure water flux (PWF) and determination of the rejection values of the pollution indices during treatment of canned beans production wastewater. According to the results, blending the PPSU solution with 10 wt.% PEG 400 resulted in formation of a nanofibrous membrane with high porosity and increased mechanical strength which exhibited a low water contact angle of 8.9° and high water flux of 7920 L/m2h. Flux recovery of the mentioned membrane which was assessed by filtration of a solution containing bovine serum albumin (BSA) was 83% indicating a noticeable antifouling property.

The effect of temperature and body size on filtration rates of Limnoperna fortunei (Bivalvia, Mytilidae under laboratory conditions

Directory of Open Access Journals (Sweden)

Débora Pestana

2009-02-01

Full Text Available The golden mussel (Limnoperna fortunei, Mollusca: Bivalvia is an invasive species that has been causing considerable environmental and economic problems in South America. In the present study, filtration rates of L. fortunei were determined in the laboratory under different temperatures (10, 15, 20, 25, 28, and 30 ºC and two types of food (Algamac-2000® and the chlorophycean alga Scenedesmus sp.. There was a statistically significant relationship between time and filtration rates in the experiment using Scenedesmus sp., regardless of temperature. However, this pattern was absent in the experiment using Algamac, suggesting that the relationship between filtration rates and temperature might depend on the size of the filtered particles. In addition, there was no correlation between filtration rates and either shell size or condition index (the relationship between the weight and the length of a mussel. The filtration rate measured in the present study (724.94 ml/h was one of the highest rates recorded among invasive bivalves to date. Given that the colonies of the golden mussel could reach hundreds of thousands of individuals per square meter, such filtration levels could severely impact the freshwater environments in its introduced range.

Particulate Matter Filtration Design Considerations for Crewed Spacecraft Life Support Systems

Science.gov (United States)

Agui, Juan H.; Vijayakumar, R.; Perry, Jay L.

2016-01-01

Particulate matter filtration is a key component of crewed spacecraft cabin ventilation and life support system (LSS) architectures. The basic particulate matter filtration functional requirements as they relate to an exploration vehicle LSS architecture are presented. Particulate matter filtration concepts are reviewed and design considerations are discussed. A concept for a particulate matter filtration architecture suitable for exploration missions is presented. The conceptual architecture considers the results from developmental work and incorporates best practice design considerations.

Microvascular filtration is increased in the forearms of patients with breast cancer-related lymphedema

DEFF Research Database (Denmark)

Jensen, Mads Radmer; Simonsen, Lene; Karlsmark, Tonny

2013-01-01

-enhanced ultrasound; venous occlusion strain-gauge plethysmography; lower-body negative pressure; noninvasive blood pressure measurements; and skin (99m)Tc-pertechnetate clearance technique. Measurements were performed bilaterally and simultaneously in the forearms, enabling use of the nonedematous forearm...... relative microvascular volume, forearm blood flow, skin blood flow, or central or local sympathetic vascular reflexes. Forearm microvascular filtration is increased in patients with BCRL, and more so in the edematous arm. The vascular sympathetic control mechanisms seem to be preserved. We propose...... with unilateral BCRL, the following aspects of upper extremity peripheral circulation were examined: muscle relative microvascular volume; capillary filtration coefficient; central and local sympathetic vascular reflexes; skin blood flow; and forearm blood flow. These were studied via real-time, contrast...

Immobilized Filters for Air Filtration

National Research Council Canada - National Science Library

Mahle, John J; Zaiee, Saeed

2002-01-01

... (settling performance) and attrition resistance. The fabricated filter samples will be analyzed in order to determine the physical and chemical factors affecting mechanical strength and chemical filtration...

Technology which led to the westinghouse inherently safe liquid metal reactor

International Nuclear Information System (INIS)

Schmidt, J.E.; Coffield, R.D.; Doncals, R.A.; Kalinowski, J.E.; Markley, R.A.

1985-01-01

The Fast Flux Test Facility (FFTF) and the Clinch River Breeder Reactor programs resulted in an understanding of liquid metal reactor behavior that is being used to design inherent safety capability into liquid metal reactors. Technological advances give the same beneficial operating characteristics of conventional liquid metal reactors, however, the addition of inherently safe design features precludes the initiation of hypothetical core disruptive accidents. These innovative features permit inherent safety capability to be demonstrated with more than adequate margins. Also, the variety of inherent safety features provides the designers with options in selecting inherent design features for a specific reactor application

Risks of using membrane filtration for trace metal analysis and assessing the dissolved metal fraction of aqueous media - A study on zinc, copper and nickel

International Nuclear Information System (INIS)

Hedberg, Yolanda; Herting, Gunilla; Wallinder, Inger Odnevall

2011-01-01

Membrane filtration is commonly performed for solid-liquid separation of aqueous solutions prior to trace metal analysis and when assessing 'dissolved' metal fractions. Potential artifacts induced by filtration such as contamination and/or adsorption of metals within the membrane have been investigated for different membrane materials, metals, applied pressures and pre-cleaning steps. Measurements have been conducted on aqueous solutions including well-defined metal standards, ultrapure water, and on runoff water from corroded samples. Filtration using both non-cleaned and pre-cleaned filters revealed contamination and adsorption effects, in particular pronounced for zinc, evident for copper but non-significant for nickel. The results clearly show these artifacts to be non-systematic both for non-cleaned and pre-cleaned membranes. The applied pressure was of minor importance. Measurements of the labile fraction by means of stripping voltammetry clearly elucidate that membrane filtration followed by total metal analysis cannot accurately assess the labile or the dissolved metal fraction. - Highlights: → Membrane filtration for trace metal analysis can introduce significant artifacts. → The dissolved metal fraction cannot be assessed by membrane filtration. → Non-specified filtration procedures are inadequate for scientific studies. → Artifacts caused by membrane filtration need to be addressed by regulators. - Membrane filtration cannot be used to assess the dissolved metal fraction of aqueous media and needs to be defined in detail in standard tests.

Filtration behavior of silver nanoparticle agglomerates and effects of the agglomerate model in data analysis

International Nuclear Information System (INIS)

Buha, Jelena; Fissan, Heinz; Wang, Jing

2013-01-01

In many data evaluation procedures for particle measuring devices and in filtration models, spherical particles are assumed. However, significant fractions of aerosol particles are agglomerates of small primary spheres. The morphology of particles in filtration processes may not be known a priori and if the filtration data are processed with wrong assumption, errors can be induced. In this work, we have quantified such errors for the case of open-structured agglomerates. Filtration efficiency tests with polydisperse silver nanoparticle agglomerates and their sintered spheres were performed. After the sintering process, particles with a compact structure with the shape close to a sphere are obtained, which are referred to as sintered spheres in the present study. The testing method involved generation of particulate forms, passing the particles through the testing section, and measurement of the particle number concentrations and size distributions before and after the filter. Measurements of the aerosols upstream and downstream of the filter were conducted using scanning mobility particle sizers (SMPS, TSI Inc.), which covered the rage from 10 to 480 nm. Particles were additionally characterized from the electron microscopic images and the average primary particle size was determined to be 16.8 nm. The number-size distribution curves were obtained and used for penetration calculation. The penetration was dependent on the particle size and morphology. Silver-sintered spheres were captured with a lower efficiency than agglomerates with the same mobility diameter because of the stronger interception effect for agglomerates. Data analysis of the number-size distribution for agglomerates was processed based on sphere assumption and using the model for open-structured agglomerates developed by Lall and Friedlander. The efficiencies based on total concentrations of number, surface and volume were affected when the agglomerate model was used. The effect was weakest for the

Method of electrostatic filtration

International Nuclear Information System (INIS)

Devienne, F.M.

1975-01-01

Electrostatic filtration of secondary ions of mass m in a given mass ratio with a primary ion of mass M which has formed the secondary ions by fission is carried out by a method which consists in forming a singly-charged primary ion of the substance having a molecular mass M and extracting the ion at a voltage V 1 with respect to ground. The primary ion crosses a potential barrier V 2 , in producing the dissociation of the ion into at least two fragments of secondary ions and in extracting the fragment ion of mass m at a voltage V 2 . Filtration is carried out in an electrostatic analyzer through which only the ions of energy eV'' are permitted to pass, detecting the ions which have been filtered. The mass m of the ions is such that (M/m) = (V 1 - V 2 )/(V'' - V 2 )

Inherent-opening-controlled pattern formation in carbon nanotube arrays

International Nuclear Information System (INIS)

Huang Xiao; Zhou, Jijie J; Sansom, Elijah; Gharib, Morteza; Haur, Sow Chorng

2007-01-01

We have introduced inherent openings into densely packed carbon nanotube arrays to study self-organized pattern formation when the arrays undergo a wetting-dewetting treatment from nanotube tips. These inherent openings, made of circular or elongated hollows in nanotube mats, serve as dewetting centres, from where liquid recedes from. As the dewetting centres initiate dry zones and the dry zones expand, surrounding nanotubes are pulled away from the dewetting centres by liquid surface tension. Among short nanotubes, the self-organized patterns are consistent with the shape of the inherent openings, i.e. slender openings lead to elongated trench-like structures, and circular holes result in relatively round nest-like arrangements. Nanotubes in a relatively high mat are more connected, like in an elastic body, than those in a short mat. Small cracks often initialize themselves in a relatively high mat, along two or more adjacent round openings; each of the cracks evolves into a trench as liquid dries up. Self-organized pattern control with inherent openings needs to initiate the dewetting process above the nanotube tips. If there is no liquid on top, inherent openings barely enlarge themselves after the wetting-dewetting treatment

Is the use of particle air filtration justified? Costs and benefits of filtration with regard to health effects, building cleaning and occupant productivity

DEFF Research Database (Denmark)

Bekö, Gabriel; Clausen, Geo; Weschler, Charles J.

2008-01-01

Estimates of costs and the corresponding benefits of particle filtration have been derived for a standard office building. Reduction in occupants’ exposure to particles during their workday is anticipated to reduce their morbidity and mortality. Filtration may also reduce the costs associated......, the sensitivity of the results to these parameters was evaluated as part of this study. The study also acknowledges that the benefits-to-costs ratio depends on the perspective of the stakeholder: the employer renting the building is impacted by occupant performance and building energy costs; the building owner...... is impacted by maintenance of the building and its HVAC system; society is impacted by the employees’ health and welfare. Regardless of perspective, particle filtration is anticipated to lead to annual savings significantly exceeding the running costs for filtration. However, economic losses resulting from...

Ozone and membrane filtration based strategies for the treatment of cork processing wastewaters

Energy Technology Data Exchange (ETDEWEB)

Benitez, F. Javier [Departamento de Ingenieria Quimica, Universidad de Extremadura, 06071 Badajoz (Spain)], E-mail: javben@unex.es; Acero, Juan L.; Leal, Ana I.; Real, Francisco J. [Departamento de Ingenieria Quimica, Universidad de Extremadura, 06071 Badajoz (Spain)

2008-03-21

The degradation of the pollutant organic matter present in the cork processing wastewater was studied by combining chemical treatments, which used ozone and some Advanced Oxidation Processes, and membrane filtration procedures. Two schemes were conducted: firstly, a single ozonation stage followed by an UF stage; and secondly, a membrane filtration stage, using different MF and UF membranes, followed by a chemical oxidation stage, where ozone, UV radiation, and the AOPs constituted by ozone plus UV radiation and ozone plus hydrogen peroxide, were used. The membrane filtration stages were carried out in tangential filtration laboratory equipment, and the membranes used were two MF membranes with pores sizes of 0.65 and 0.1 {mu}m, and three UF membranes with molecular weights cut-off of 300, 10, and 5 kDa. The effectiveness of the different stages (conversions in the chemical procedures and rejection coefficients in the membrane processes) were evaluated in terms of several parameters which measure the global pollutant content of the wastewater: COD, absorbance at 254 nm, tannins content, color, and ellagic acid. In the ozonation/UF combined process the following removals were achieved: 100% for ellagic acid and color, 90% for absorbance at 254 nm, more than 80% for tannins, and 42-57% for COD reduction. In the filtration/chemical oxidation combined process, 100% elimination of ellagic acid, more than 90% elimination in color, absorbance at 254 nm and tannins, and removal higher than 80% in COD were reached, which indicates a greater purification power of this combination.

Cross-flow micro-filtration using ceramic membranes

International Nuclear Information System (INIS)

Thern, Gerardo G.; Marajofsky, Adolfo; Rossi, Federico; La Gamma, Ana M.; Chocron, Mauricio

2004-01-01

Pressurized Heavy Water Reactors have a system devoted to the purification and upgrading of the collected heavy water leaks. The purification train is fed with different degradation ratios (D 2 O/H 2 O), activities and impurities. The water is distilled in a packed bed column filled with a mesh type packing. With the purpose of minimizing the column stack corrosion, the water is pre-treated in a train consisting on an activated charcoal bed-strong cationic-anionic resin and a final polishing anionic bed resin. Traces of oils are retained by the charcoal bed but some of them pass through and could be responsible for the resins fouling. The process of micro filtration using ceramic materials is particularly applied to the treatment of waters with oil micro droplets. We describe the development stages of single and double layer filtration ceramic tubes, their characterization and the adaptation to test equipment. The efficiency was evaluated by means of tangential ('cross-flow') filtration of aqueous solutions containing dodecane at the micrograms per ml concentration level. This compound simulates the properties of a typical oil contaminant. A 100-fold reduction in the amount of dodecane in water was observed after the filtration treatment. (author)

MATHEMATIC MODEL OF ELECTROMAGNETIC FILTRATION PROCESS OF TECHNOLOGICAL LIQUID AND GAS

OpenAIRE

R. A. Мouradova

2005-01-01

Electromagnetic filtration as a perspective method of filtration and purification of liquid and gas finds its wide application in oil and chemical industry. However absence of highly-reliable model of calculation that permits unambiguously main operational parameters of electromagnetic filtration and limits its wide application. 

Filtration system for nuclear power plant

International Nuclear Information System (INIS)

Otani, Takashi; Nakamizo, Hiroshi.

1991-01-01

The filtration system of the present invention comprises a filtering device incorporating ceramic filament element bundles, a pool return line for returning filtrates to a side banker pool or fuel storage pool, a waste sludge discharge line for discharging waste sludges captured in the filter elements by way of washing operation and a settling separation vessel. Ceramics of excellent radiation resistance and having an extremely thin multi-layered structure at the surface are used for the filter elements. Highly radioactive cruds captured at the surface of the elements by liquid passage are removed by supplying water or gas in a pulsative manner in the direction opposite to the liquid passage thereby cleaning the surface of the elements at a high speed. The thus removed high radioactive cruds are concentrically confined within the settling separation layer by gravitational settling separation. Thus, there is no more necessary for disposing the filtration element bundles after use, so that the amount of wastes can be reduced, the radiation dosage can be lowered and the facility can be simplified. (N.H.)

Evaluation of condensate filtration technologies in fossil plants

Energy Technology Data Exchange (ETDEWEB)

D' Angelo, Philip J. [JoDan Technologies Ltd., Glen Mills, PA (United States)

2009-09-15

Long-term protection of electric power generating station boilers depends upon the quality of their feedwater chemistry with respect to the transport and deposition of corrosion products to the boilers from various corrosion sources in the plant's condensate and feedwater cycle. It is in the utility's best interests to expand their programs to include ways to reduce the transport of corrosion products, especially those that occur during plant start-ups. Condensate filtration is a strategy employed by some utilities with demonstrable results in minimizing corrosion product transport and achieving a return on their investment. This paper provides a comparative review of available condensate filtration technologies as well as performance data from fossil plants with the new large diameter high flow filtration systems. Additionally, the paper identifies critical parameters to consider before installation as well as the necessity for agreement between utilities and suppliers on common filtration terminology definitions, to insure an ''apple-to-apple'' basis when comparing a system or technology from more than one supplier. (orig.)

The inherently-safe power reactor DYONISOS (Dynamic Nuclear Inherently-Safe Reactor Operating with Spheres)

International Nuclear Information System (INIS)

Taube, M.; Lanfranchi, M.; Weissenfluh, Th. von; Ligou, J.; Yadigaroglu, G.; Taube, P.

1986-01-01

A philosophy of inherent safety is formulated and an inherently-safe thermal power reactor is presented. Solid fuel in the form of spheres a few centimetres in diameter is suspended under the hydro-dynamic pressure of molten lead coolant in vertical channels within the graphite moderator. Loss of main pump pressure, or a loss-of-coolant accident (LOCA), results in immediate removal of the fuel to rigid sieves below the core, with consequent subcriticality. Residual and decay heat are carried away by thermal conduction through the coolant or, in the case of a LOCA, by a combination of radiation and natural convection of cover gas or incoming air from the fuel to the reactor vessel and convection of air between the vessel and steel containment wall. All decay heat removal systems are passive, though actively initiated external spray cooling of the containment can be used to reduce wall temperature. This, however, is only necessary in the case of a LOCA and after a period of 24 h. (author)

Transcutaneous glomerular filtration rate measurement in a canine animal model of chronic kidney disease.

Science.gov (United States)

Mondritzki, Thomas; Steinbach, Sarah M L; Boehme, Philip; Hoffmann, Jessica; Kullmann, Maximilian; Schock-Kusch, Daniel; Vogel, Julia; Kolkhof, Peter; Sandner, Peter; Bischoff, Erwin; Hüser, Jörg; Dinh, Wilfried; Truebel, Hubert

Quantitative assessment of renal function by measurement of glomerular filtration rate (GFR) is an important part of safety and efficacy evaluation in preclinical drug development. Existing methods are often time consuming, imprecise and associated with animal burden. Here we describe the comparison between GFR determinations with sinistrin (PS-GFR) and fluorescence-labelled sinistrin-application and its transcutaneous detection (TD-GFR) in a large animal model of chronic kidney disease (CKD). TD-GFR measurements compared to a standard method using i.v. sinistrin were performed in a canine model. Animals were treated with one-sided renal wrapping (RW) followed by renal artery occlusion (RO). Biomarker and remote hemodynamic measurements were performed. Plasma sinistrin in comparison to transcutaneous derived GFR data were determined during healthy conditions, after RW and RW+RO. RW alone did not led to any significant changes in renal function, neither with PS-GFR nor TD-GFR. Additional RO showed a rise in blood pressure (+68.0mmHg), plasma urea (+28.8mmol/l), creatinine (+224,4μmol/l) and symmetric dimethylarginine (SDMA™; +12.6μg/dl). Plasma sinistrin derived data confirmed the expected drop (-44.7%, p<0.0001) in GFR. The calculated transcutaneous determined Fluorescein Isothiocyanate (FITC)-sinistrin GFR showed no differences to plasma sinistrin GFR at all times. Both methods were equaly sensitive to diagnose renal dysfunction in the affected animals. Renal function assessment using TD-GFR is a valid method to improve preclinical drug discovery and development. Furthermore, TD-GFR method offers advantages in terms of reduced need for blood sampling and thus decreasing animal burden compared to standard procedures. Copyright © 2017 Elsevier Inc. All rights reserved.

Impact of Acidification on Pollutants Fate and Soil Filtration Function

Directory of Open Access Journals (Sweden)

Jarmila Makovniková

2014-12-01

Full Text Available The objective of this paper was to investigate the effects of simulated acid load on the fate of inorganic pollutants (Cd, Pb, soil sorption potential, soil filtration func-tion. We made use of a short-term acidification pot experiment with grown plant of spring barley cultivated at 4 different soil types (Fluvisol, Cambisol, Stagnosol, Podzol. The potential of soil filtration was evaluated according to the Eq.: [Soil filtration function]=[Potential of soil sorbents]+[Potential of total content of inor-ganic pollutants]. Potential of soil sorbents (PSS is defined by qualitative (pH, or-ganic matter quality - A400/600 and quantitative factors (carbon content-Cox, humus layer thickness-H according to the Eq.:[PSS]=F(pH+F(A465/665+F(Cox*F(H. Acid load significantly influenced soil sorption potential and thus affected increase in Cd and Pb mobility what was reflected in their transfer into the plants. Results of soil filtration function showed significant change of filtration function in Cambisol.

Development of physiotherapy inherent requirement statements – an Australian experience

Science.gov (United States)

2013-01-01

Background The United Nations Convention on the Rights of People with Disabilities promotes equal rights of people with a disability in all aspects of their life including their education. In Australia, Disability Discrimination legislation underpins this Convention. It mandates that higher education providers must demonstrate that no discrimination has occurred and all reasonable accommodations have been considered and implemented, to facilitate access and inclusion for a student with a disability. The first step to meeting legislative requirements is to provide students with information on the inherent requirements of a course. This paper describes the steps which were taken to develop inherent requirement statements for a 4-year entry-level physiotherapy program at one Australian university. Case presentation Inherent requirement statements were developed using an existing framework, which was endorsed and mandated by the University. Items which described inherencies were extracted from Australian physiotherapy professional standards and statutory regulatory requirements, and units contained in the physiotherapy program. Data were integrated into the 8 prescribed domains: ethical behaviour, behavioural stability, legal, communication, cognition, sensory abilities, strength and mobility, and sustainable performance. Statements for each domain were developed using a 5-level framework (introductory statement, description of the inherent requirement, justification for inherency, characteristics of reasonable adjustments and exemplars) and reviewed by a University Review Panel. Refinement of statements continued until no further changes were required. Fifteen physiotherapy inherent requirement statements were developed. The eight domains identified in the existing framework, developed for Nursing, were relevant to the study of physiotherapy. Conclusions The inherent requirement statements developed in this study provide a transparent, defensible position on the

Searching for Models Exhibiting High Circularly Polarized Luminescence: the Electroactive Inherently Chiral Oligothiophenes.

Science.gov (United States)

Benincori, Tiziana; Appoloni, Giulio; Mussini, Patrizia Romana; Arnaboldi, Serena; Cirilli, Roberto; Quartapelle Procopio, Elsa; Panigati, Monica; Abbate, Sergio; Mazzeo, Giuseppe; Longhi, Giovanna

2018-05-02

Two new inherently chiral oligothiophenes characterized by the atropisomeric 3,3'-bithianaphtene scaffold functionalized with fused ring bithiophene derivatives, namely 4H-cyclopenta [2,1-b3:4b']dithiophene (CPDT) and dithieno[3,3-b:2',3'-d]pyrrole (DTP), were synthesized. The racemates were fully characterized and resolved into antipodes by enantioselective HPLC. The enantiomers were analyzed through different chiroptical techniques: electronic circular dichroism (ECD) and vibrational circular dichroism (VCD) were employed to attribute the absolute configuration (AC). Comparison of experimental and calculated VCD spectra confirmed the DFT calculated conformational characteristics. The compound functionalized with two CPDT units was oxidized with FeCl3 and ECD and CPL of the resulting material were measured. Circularly Polarized Luminescence (CPL) was measured in order to verify if inherently chiral oligothiophenes could be promising systems for chiral photonics applications. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Effect of rare earth filtration on patient exposure, dose reduction, and image quality in oral panoramic radiology

International Nuclear Information System (INIS)

Tyndall, D.A.; Washburn, D.B.

1987-01-01

Rare earth intensifying screen material (Gd2O2S:Tb) was added to the standard Al filtration of an oral panoramic x-ray unit, resulting in a beam capable of achieving reductions in patient dose without a loss of image quality. The added rare earth filtration technique resulted in patient dose reductions of 21-56%, depending on anatomic sites, when compared to the conventional Al filtration technique. Films generated from both techniques were measured densitometrically and evaluated by a panel of practicing clinicians. Diagnostically significant differences were minimal. The results indicate that use of rare earth filters in oral panoramic radiography is an effective means of reducing exposures of dental patients to ionizing radiation

Water Treatment Technology - Filtration.

Science.gov (United States)

Ross-Harrington, Melinda; Kincaid, G. David

One of twelve water treatment technology units, this student manual on filtration provides instructional materials for six competencies. (The twelve units are designed for a continuing education training course for public water supply operators.) The competencies focus on the following areas: purposes of sedimentation basins and flocculation…

The representation of inherent properties.

Science.gov (United States)

Prasada, Sandeep

2014-10-01

Research on the representation of generic knowledge suggests that inherent properties can have either a principled or a causal connection to a kind. The type of connection determines whether the outcome of the storytelling process will include intuitions of inevitability and a normative dimension and whether it will ground causal explanations.

Analysis of filtration properties of locally sourced base oil for the ...

African Journals Online (AJOL)

This study examines the use of locally sourced oil like, groundnut oil, melon oil, vegetable oil, soya oil and palm oil as substitute for diesel oil in formulating oil base drilling fluids relative to filtration properties. The filtrate volumes of each of the oils were obtained for filtration control analysis. With increasing potash and ...

Additive Difference Schemes for Filtration Problems in Multilayer Systems

CERN Document Server

Ayrjan, E A; Pavlush, M; Fedorov, A V

2000-01-01

In the present paper difference schemes for solution of the plane filtration problem in multilayer systems are analyzed within the framework of difference schemes general theory. Attention is paid to splitting the schemes on physical processes of filtration along water-carring layers and vertical motion between layers. Some absolutely stable additive difference schemes are obtained the realization of which needs no software modification. Parallel algorithm connected with the solving of the filtration problem in every water-carring layer on a single processor is constructed. Program realization on the multi-processor system SPP2000 at JINR is discussed.

Preliminary evaluation of fungicidal and termiticidal activities of filtrates from biomass slurry fuel production

Energy Technology Data Exchange (ETDEWEB)

Kartal, S.N. [Istanbul University (Turkey). Forestry Faculty; Imamura, Y. [Kyoto University (Japan). Wood Research Institute; Tsuchiya, F.; Ohsato, K. [JGC Corporation, Yokohama (Japan)

2004-10-01

Biomass slurry fuel (BSF) production has recently been developed as a natural energy for the conversion of solid biomass into fuel. In addition to using fuel, filtrates from BSF production may also serve a chemical source with several organic compounds. There is an increasing interest in the research and application of biomass-based filtrates. In this study, fungicidal and termiticidal properties of filtrates from BSF production using sugi (Cryptomeria japonica) and acacia (Acacia mangium) wood were evaluated in laboratory decay and termite resistance tests. Wood blocks treated with the filtrates showed increased resistance against brown-rot fungus, Formitopsis palustris. However the filtrates from sugi wood processed at 270{sup o}C which contained less phenolic compounds than the other filtrates were effective against white-rot fungus, Trametes versicolor. Phenolic compounds of filtrates seemed to play a role in the decay resistance tests however the filtrates did not increase the durability of the wood blocks against subterranean termites Coptotermes formosanus. Despite high acetic and lactic acid content of the filtrates, vanillin content of the filtrates may have served as an additional food source and promoted termite attack. It can be concluded that filtrates with phenolic compounds from lignin degradation during BSF production can be considered for targeted inhibition of brown-rot. (author)

Properties of plastic filtration material

Energy Technology Data Exchange (ETDEWEB)

Paluch, W.

1988-01-01

Discusses properties of filters made of thermoplastic granulated material. The granulated plastic has a specific density of 10.3-10.6 kN/m/sup 3/ and a bulk density of about 6 kN/m/sup 3/. Its chemical resistance to acids, bases and salts is high but is it soluble in organic solvents. Filters made of this material are characterized by a porosity coefficient of 36.5% and a bulk density of 5.7-6.8 kN/m/sup 3/. Physical and mechanical properties of filter samples made of thermoplastic granulated material (50x50x50 mm) were investigated under laboratory conditions. Compression strength and influencing factors were analyzed (ambient temperature, manufacturing technology). Tests show that this filtration material developed by Poltegor is superior to other filtration materials used in Poland.

Forced-air warming design: evaluation of intake filtration, internal microbial buildup, and airborne-contamination emissions.

Science.gov (United States)

Reed, Mike; Kimberger, Oliver; McGovern, Paul D; Albrecht, Mark C

2013-08-01

Forced-air warming devices are effective for the prevention of surgical hypothermia. However, these devices intake nonsterile floor-level air, and it is unknown whether they have adequate filtration measures to prevent the internal buildup or emission of microbial contaminants. We rated the intake filtration efficiency of a popular current-generation forced-air warming device (Bair Hugger model 750, Arizant Healthcare) using a monodisperse sodium chloride aerosol in the laboratory. We further sampled 23 forced-air warming devices (same model) in daily hospital use for internal microbial buildup and airborne-contamination emissions via swabbing and particle counting. Laboratory testing found the intake filter to be 63.8% efficient. Swabbing detected microorganisms within 100% of the forced-air warming blowers sampled, with isolates of coagulase-negative staphylococci, mold, and micrococci identified. Particle counting showed 96% of forced-air warming blowers to be emitting significant levels of internally generated airborne contaminants out of the hose end. These findings highlight the need for upgraded intake filtration, preferably high-efficiency particulate air filtration (99.97% efficient), on current-generation forced-air warming devices to reduce contamination buildup and emission risks.

An inherently safe power reactor module

International Nuclear Information System (INIS)

Salerno, L.N.

1985-01-01

General Electric's long participation in liquid metal reactor technology has led to a Power Reactor Inherently Safe Module (PRISM) concept supported by DOE contract DE-AC06-85NE37937. The reactor module is sized to maximize inherent safety features. The small size allows factory fabrication, reducing field construction and field QA/QC labor, and allows safety to be demonstrated in full scale, to support a pre-licensed standard commercial product. The module is small enough to be placed underground, and can be combined with steam and electrical generating equipment to provide a complete electrical power producing plant in the range of 400-1200 MWe. Initial assessments are that the concept has the potential to be economically competitive with existing methods of power production used by the utility industry

Blood flow vs. venous pressure effects on filtration coefficient in oleic acid-injured lung.

Science.gov (United States)

Anglade, D; Corboz, M; Menaouar, A; Parker, J C; Sanou, S; Bayat, S; Benchetrit, G; Grimbert, F A

1998-03-01

On the basis of changes in capillary filtration coefficient (Kfc) in 24 rabbit lungs, we determined whether elevations in pulmonary venous pressure (Ppv) or blood flow (BF) produced differences in filtration surface area in oleic acid-injured (OA) or control (Con) lungs. Lungs were cyclically ventilated and perfused under zone 3 conditions by using blood and 5% albumin with no pharmacological modulation of vascular tone. Pulmonary arterial, venous, and capillary pressures were measured by using arterial, venous, and double occlusion. Before and during each Kfc-measurement maneuver, microvascular/total vascular compliance was measured by using venous occlusion. Kfc was measured before and 30 min after injury, by using a Ppv elevation of 7 cmH2O or a BF elevation from 1 to 2 l . min-1 . 100 g-1 to obtain a similar double occlusion pressure. Pulmonary arterial pressure increased more with BF than with Ppv in both Con and OA lungs [29 +/- 2 vs. 19 +/- 0.7 (means +/- SE) cmH2O; P Kfc (200 +/- 40 vs. 83 +/- 14%, respectively; P < 0.01) and microvascular/total vascular compliance ratio (86 +/- 4 vs. 68 +/- 5%, respectively; P < 0.01) increased more with BF than with Ppv. In conclusion, for a given OA-induced increase in hydraulic conductivity, BF elevation increased filtration surface area more than did Ppv elevation. The steep pulmonary pressure profile induced by increased BF could result in the recruitment of injured capillaries and could also shift downstream the compression point of blind (zone 1) and open injured vessels (zone 2).

Development of nondestructive hybrid measuring method for three-dimensional residual stress distribution of thick welded joint. Hybrid measuring method of inherent strain method and neutron diffraction method

International Nuclear Information System (INIS)

Nakacho, Keiji; Kasahara, Norifumi; Tamura, Ryota

2012-01-01

The measuring methods of the residual stress are classified into destructive one and nondestructive one. The inherent strain method (ISM) is destructive one. The neutron diffraction method (NDM) is nondestructive one. But the measurable depth is limited within about 20 mm and the method cannot measure the weld zone, without destruction of the object. So, in this study, the hybrid measuring method has been developed, by combining the ISM and the NDM. The theory of the hybrid method is the same as the ISM. In the analysis, the strains measured by the NDM without destruction are used. This hybrid measuring method is a true nondestructive measuring method for a thick welded joint. The applicability of the hybrid method has been verified by simulation, using a butt welded joint of thick pipes. In the simulation, the reliable order of the strains measured by the present NDM is very important, and was considered as 10 micro. The measurable regions by the present NDM were assumed. Under the above conditions, the data (the residual elastic strains assumed to be measured by the NDM) were made, and used in the ISM. As a result of such simulation, it has been cleared that the estimated residual stress has very high accuracy, if enough data are used. The required number of data is less than the ISM. (author)

Microalgae fractionation using steam explosion, dynamic and tangential cross-flow membrane filtration.

Science.gov (United States)

Lorente, E; Hapońska, M; Clavero, E; Torras, C; Salvadó, J

2017-08-01

In this study, the microalga Nannochloropsis gaditana was subjected to acid catalysed steam explosion treatment and the resulting exploded material was subsequently fractionated to separate the different fractions (lipids, sugars and solids). Conventional and vibrational membrane setups were used with several polymeric commercial membranes. Two different routes were followed: 1) filtration+lipid solvent extraction and 2) lipid solvent extraction+filtration. Route 1 revealed to be much better since the used membrane for filtration was able to permeate the sugar aqueous phase and retained the fraction containing lipids; after this, an extraction required a much lower amount of solvent and a better recovering yield. Filtration allowed complete lipid rejection. Dynamic filtration improved permeability compared to the tangential cross-flow filtration. Best membrane performance was achieved using a 5000Da membrane with the dynamic system, obtaining a permeability of 6L/h/m 2 /bar. Copyright © 2017 Elsevier Ltd. All rights reserved.

Purification of contaminated water by filtration through porous glass

Science.gov (United States)

Wydeven, T.; Leban, M. I.

1972-01-01

Method for purifying water that is contaminated with mineral salts and soluble organic compounds is described. Method consists of high pressure filtration of contaminated water through stabilized porous glass membranes. Procedure for conducting filtration is described. Types of materials by percentage amounts removed from the water are identified.

Measurement of glomerular filtration rate using technetium-99m-DTPA and the gamma camera: A comparison of methods

International Nuclear Information System (INIS)

Russell, C.D.; Bischoff, P.G.; Kontzen, F.; Rowell, K.L.; Yester, M.V.; Lloyd, L.K.; Tauxe, W.N.; Dubovsky, E.V.

1984-01-01

A variety of methods has been proposed to estimate glomerular filtration rate (GFR) from renal uptake of Tc-99m-DTPA using a gamma camera. To compare alternative methods, the authors have calculated GFR in several different ways from measurements in 33 patients, and compared the results with an independent GFR measurement based on 8-point plasma clearance of Yb-169-DTPA. The best agreement was obtained using an algorithm that has not been described previously. This was a modification of a method used previously in which correction was made for overlap of kidneys by liver and spleen. The correlation coefficient was 0.958 and the residual standard deviation was 12.1 ml/min. This method required a single 20-min blood sample as well as the camera data. The best method not requiring a blood sample was significantly less accurate, with correlation coefficient 0.866 and residual standard deviation 21.1 ml/min. The accuracy of these methods was comparable to that reported for the creatinine clearance, the most commonly used estimate of GFR in current clinical practice

Pathogen filtration to control plant disease outbreak in greenhouse production

Science.gov (United States)

Jeon, Sangho; Krasnow, Charles; Bhalsod, Gemini; Granke, Leah; Harlan, Blair; Hausbeck, Mary; Zhang, Wei

2016-04-01

Previous research has been extensively focused on understanding the fate and transport of human microbial pathogens in soil and water environments. However, little is known about the transport of plant pathogens, although these pathogens are often found in irrigation waters and could cause severe crop damage and economical loss. Water mold pathogens including Phytophthora spp. and Pythium spp. are infective to a wide range of vegetable and floriculture crops, and they are primarily harbored in soils and disseminated through water flow. It is challenging to control these pathogens because they often quickly develop resistance to many fungicides. Therefore, this multi-scale study aimed to investigate physical removal of plant pathogens from water by filtration, thus reducing the pathogen exposure risks to crops. In column-scale experiments, we studied controlling factors on the transport and retention of Phytophthora capsici zoospores in saturated columns packed with iron oxide coated-sand and uncoated-sand under varying solution chemistry. Biflagellate zoospores were less retained than encysted zoospores, and lower solution pH and greater iron oxide content increased the retention of encysted zoospores. These results provided insights on environmental dispersal of Phytophthora zoospores in natural soils as well as on developing cost-effective engineered filtration systems for pathogen removal. Using small-scale greenhouse filtration systems, we further investigated the performance of varying filter media (i.e., granular sand, iron oxide coated ceramic porous media, and activated carbon) in mitigating disease outbreaks of Phytophthora and Pythium for greenhouse-grown squash and poinsettia, respectively, in comparison with fungicide treatment. For squash, filtration by iron oxide coated media was more effective in reducing the Phytophthora infection, comparing to sand filtration and fungicide application. For poinsettia, sand filtration performed better in controlling

Invasive aspergillosis in severely neutropenic patients over 18 years: impact of intranasal amphotericin B and HEPA filtration.

Science.gov (United States)

Withington, S; Chambers, S T; Beard, M E; Inder, A; Allen, J R; Ikram, R B; Schousboe, M I; Heaton, D C; Spearing, R I; Hart, D N

1998-01-01

The impact of intranasal amphotericin B and high-efficiency particulate air (HEPA) filtration on the incidence of invasive aspergillosis was reviewed in patients from 1977 to 1994 undergoing intensive chemotherapy. Overall, the incidence of proven invasive aspergillosis was reduced from 24.4% (1977-1984) to 7.1% (1985-1991) (P < 0.001) following the introduction of intranasal prophylaxis, but when probable cases of aspergillosis were included and lymphoma cases excluded, there was no change in incidence. Following the introduction of HEPA filtration, patient exposure to aspergillus spores as measured by air sampling was markedly reduced and there were no new cases of invasive aspergillosis. HEPA filtration proved effective in reducing invasive aspergillosis and has allowed increasingly aggressive treatment regimens to be introduced.

Development of quantitative goals for inherent safety feature design and licensing

International Nuclear Information System (INIS)

Kastenberg, W.E.; Apostolakis, G.; Dhir, V.K.; Okrent, D.

1987-01-01

There is now considerable interest in the development of advanced fast reactors whose major focus is inherent safety. The achievement of inherent safety can be viewed from several aspects. In the Integral Fast Reactor Concept the approach is to utilize the intrinsic characteristics of pool-type liquid metal fast breeder reactors (LMFBRs) and the properties of metal fuels to integrate a high degree of inherent safety into the design. The PRISM and SAFR concepts focus on other inherent safety features. The reactors discussed above represent a radical departure from existing LWR designs as well as previous LMFBR designs (e.g., CRBRP) which are based, for the most part, on the General Design Criteria found in 10CFR50 Appendix. In view of these parallel developments (advanced reactors exploiting inherent safety and the use of quantitative goals to augment licensing), there appears to be a need to perform research on the development of methods for designing, assessing, and licensing inherent safety features in advanced reactors. The objectives of such research are outlined

Horizontal-belt filtration at Randfontein Estates Mine

International Nuclear Information System (INIS)

Blendulf, K.A.G.; Everett, D.J.

1979-01-01

The paper describes tests on horizontal-belt filters for the filtration of gold and uranium. The promising results led to the installation of 17 such filters (ten of them 120 m 2 in size) in the mine's metallurgical plants, and their operation is discussed. Although several problems were encountered both in operation and maintenance, it is concluded that, with correct operation and suitable filter cloths, exceptionally good metallurgical recoveries can be achieved at filtration rates twice to three times higher than those on rotary filters [af

Challenges of Membrane Filtration for Produced Water Treatment in Offshore Oil & Gas Production

DEFF Research Database (Denmark)

Jepsen, Kasper Lund; Hansen, Leif; Mai, Christian

2016-01-01

struggling to their fundamental limit, therefore the membrane filtration technology turns to be a potential candidate for zero pollutant discharge. Membrane filtration technology suffers from the notorious fouling problem, where many methods for fouling prevention and removal are explored, the general idea...... is to guarantee that a relatively high permeability can be kept during filtration. Another crucial issue using membrane filtration technology is its huge energy consumption, for which there is little research has been done so far to systematically investigate and optimize the filtration system’s energy efficiency...

Landfill Leachate Treatment by Electrocoagulation and Fiber Filtration.

Science.gov (United States)

Li, Runwei; Wang, Boya; Owete, Owete; Dertien, Joe; Lin, Chen; Ahmad, Hafiz; Chen, Gang

2017-11-01

  Landfilling is widely adopted as one of the most economical processes for solid waste disposal. At the same time, landfill leachate is also a great environmental concern owing to its complex composition and high concentrations of contaminants. This research investigated electrocoagulation and fiber filtration for the treatment of landfill leachate. Besides electrical current (i.e., current density) and reaction time, pH played a very important role in arsenic and phosphorus removal by electrocoagulation. The combination of electrocoagulation with fiber filtration achieved a 94% chemical oxygen demand (COD), 87% arsenic, 96% iron, and 86% phosphorus removal. During electrocoagulation, the micro-particles that could not be settled by gravity were removed by the first stage of fiber filtration. Organic contaminants in the leachate were further removed by biodegradation in the second stage of fiber biofiltration.

Penetration of sub-micron aerosol droplets in composite cylindrical filtration elements

International Nuclear Information System (INIS)

Geurts, Bernard J.; Pratte, Pascal; Stolz, Steffen; Stabbert, Regina; Poux, Valerie; Nordlund, Markus; Winkelmann, Christoph

2011-01-01

Advection-diffusion transport of aerosol droplets in composite cylindrical filtration elements is analyzed and compared to experimental data. The penetration, characterizing the fraction of droplets that passes through the pores of a filtration element, is quantified for a range of flow rates. The advection-diffusion transport in a laminar Poiseuille flow is treated numerically for slender pores using a finite difference approach in cylindrical coordinates. The algebraic dependence of the penetration on the Peclet number as predicted theoretically, is confirmed by experimental findings at a variety of aspect ratios of the cylindrical pores. The effective penetration associated with a composite filtration element consisting of a set of parallel cylindrical pores is derived. The overall penetration of heterogeneous composite filtration elements shows an algebraic dependence to the fourth power on the radii of the individual pores that are contained. This gives rise to strong variations in the overall penetration in cases with uneven distributions of pore sizes, highly favoring filtration by the larger pores. The overall penetration is computed for a number of basic geometries, providing a point of reference for filtration design and experimental verification.

Measurement of Biocolloid Collision Efficiencies for Granular Activated Carbon by Use of a Two-Layer Filtration Model

Science.gov (United States)

Paramonova, Ekaterina; Zerfoss, Erica L.; Logan, Bruce E.

2006-01-01

Point-of-use filters containing granular activated carbon (GAC) are an effective method for removing certain chemicals from water, but their ability to remove bacteria and viruses has been relatively untested. Collision efficiencies (α) were determined using clean-bed filtration theory for two bacteria (Raoutella terrigena 33257 and Escherichia coli 25922), a bacteriophage (MS2), and latex microspheres for four GAC samples. These GAC samples had particle size distributions that were bimodal, but only a single particle diameter can be used in the filtration equation. Therefore, consistent with previous reports, we used a particle diameter based on the smallest diameter of the particles (derived from the projected areas of 10% of the smallest particles). The bacterial collision efficiencies calculated using the filtration model were high (0.8 ≤ α ≤ 4.9), indicating that GAC was an effective capture material. Collision efficiencies greater than unity reflect an underestimation of the collision frequency, likely as a result of particle roughness and wide GAC size distributions. The collision efficiencies for microspheres (0.7 ≤ α ≤ 3.5) were similar to those obtained for bacteria, suggesting that the microspheres were a reasonable surrogate for the bacteria. The bacteriophage collision efficiencies ranged from ≥0.2 to ≤0.4. The predicted levels of removal for 1-cm-thick carbon beds ranged from 0.8 to 3 log for the bacteria and from 0.3 to 1.0 log for the phage. These tests demonstrated that GAC can be an effective material for removal of bacteria and phage and that GAC particle size is a more important factor than relative stickiness for effective particle removal. PMID:16885264

Indexing Glomerular Filtration Rate to Body Surface Area

DEFF Research Database (Denmark)

Redal-Baigorri, Belén; Rasmussen, Knud; Heaf, James Goya

2014-01-01

BACKGROUND: Kidney function is mostly expressed in terms of glomerular filtration rate (GFR). A common feature is the expression as ml/min per 1.73 m(2) , which represents the adjustment of the individual kidney function to a standard body surface area (BSA) to allow comparison between individuals....... We investigated the impact of indexing GFR to BSA in cancer patients, as this BSA indexation might affect the reported individual kidney function. METHODS: Cross-sectional study of 895 adults who had their kidney function measured with (51) chrome ethylene diamine tetraacetic acid. Mean values of BSA...

Ocean Optics Protocols for Satellite Ocean Color Sensor Validation, Revision 4, Volume IV: Inherent Optical Properties: Instruments, Characterizations, Field Measurements and Data Analysis Protocols

Science.gov (United States)

Mueller, J. L.; Fargion, G. S.; McClain, C. R. (Editor); Pegau, S.; Zanefeld, J. R. V.; Mitchell, B. G.; Kahru, M.; Wieland, J.; Stramska, M.

2003-01-01

This document stipulates protocols for measuring bio-optical and radiometric data for the Sensor Intercomparision and Merger for Biological and Interdisciplinary Oceanic Studies (SIMBIOS) Project activities and algorithm development. The document is organized into 6 separate volumes as Ocean Optics Protocols for Satellite Ocean Color Sensor Validation, Revision 4. Volume I: Introduction, Background, and Conventions; Volume II: Instrument Specifications, Characterization and Calibration; Volume III: Radiometric Measurements and Data Analysis Methods; Volume IV: Inherent Optical Properties: Instruments, Characterization, Field Measurements and Data Analysis Protocols; Volume V: Biogeochemical and Bio-Optical Measurements and Data Analysis Methods; Volume VI: Special Topics in Ocean Optics Protocols and Appendices. The earlier version of Ocean Optics Protocols for Satellite Ocean Color Sensor Validation, Revision 3 is entirely superseded by the six volumes of Revision 4 listed above.

Radiotracer technique to quantify change in filtration velocity as a measure of dilution effect by artificial recharge in an arsenic infested aquifer at Ashoknagar, Habra - II block, 24 Paragana district, West Bengal

International Nuclear Information System (INIS)

Kulkarni, U.P.; Sharma, Suman

2004-01-01

Radioisotopes are frequently employed as tracers for various applications in industry, agricultural, medicine and hydrology. In hydrology, radiotracers are commonly applied to investigate several hydrological parameters of aquifers such as hydraulic conductivity, groundwater velocity and direction of flow etc. They impart valuable insight into the understanding of the hydrological systems. Application of radioisotopes in determination of groundwater flow velocity is now a well established technique. In this paper, groundwater filtration velocity was determined in an arsenic infested alluvium aquifer at Ashoknagar, Habra, West Bengal for determining the dilution effect due to arsenic free water. In some parts of West Bengal, generally shallow aquifers up to 80 m deep are contaminated due to geogenic arsenic. Researchers have different views about origin and mobility of arsenic in the groundwaters of West Bengal. For the removal of Arsenic from the groundwater various methods have been suggested and implemented such as ion-exchange, co-precipitation, adsorption, membrane separation and dilution etc. Dilution of the Arsenic concentration by artificial recharge of arsenic free water from the constructed pits in the contaminated aquifer is one such simple method. Efficacy of this method was studied by measuring filtration velocity in the contaminated aquifer at the Ashoknagar, Habra - II Block, North 24 Paragana district, West Bengal. Radioactive 82 Br in the form of aqueous ammonium bromide was used as a tracer to measure filtration velocity of the groundwater. Point dilution technique in a single well was applied. Filtration velocity provided relevant information about the arsenic dilution in the groundwater by the artificial recharge and its value will be used as a model parameter. (author)

OPTIMIZATION OF THE PROCESS OF DRYING THE FILTRATE DISTILLERY DREGS

Directory of Open Access Journals (Sweden)

A. A. Shevtsov

2013-01-01

Full Text Available The interactions of various factors affecting the process of drying the filtrate distillery dregs are investigated. Rational conditions for the process of drying the filtrate distillery dregs in a spray dryer are obtained.

Informing patients of risks inherent in treatment.

Science.gov (United States)

Griffith, Richard; Tengnah, Cassam

2009-11-01

Consent to treatment lies at the heart of autonomous decision making by patients who are entitled to make a free choice about whether to accept or refuse treatment. To help patients arrive at their decision district nurses must ensure that they give sufficient information about the nature and risks inherent in the treatment to allow an informed choice to be made. This article considers how much information regarding risks needs to be disclosed. It discusses how the law requires a different level of disclosure for patients who ask no questions about risks, those who make general enquiries about risks and those who ask specific questions about the risks inherent in treatment.

Does the inherence heuristic take us to psychological essentialism?

Science.gov (United States)

Marmodoro, Anna; Murphy, Robin A; Baker, A G

2014-10-01

We argue that the claim that essence-based causal explanations emerge, hydra-like, from an inherence heuristic is incomplete. No plausible mechanism for the transition from concrete properties, or cues, to essences is provided. Moreover, the fundamental shotgun and storytelling mechanisms of the inherence heuristic are not clearly enough specified to distinguish them, developmentally, from associative or causal networks.

Sieve plugs in fenestrae of glomerular capillaries--site of the filtration barrier?

DEFF Research Database (Denmark)

Rostgaard, Jørgen; Qvortrup, Klaus

2002-01-01

The exact location of the filtration barrier of the glomerular capillary wall, which consists of an endothelium, a basement membrane and a visceral epithelium, has not yet been determined. Apparent discrepancies between different investigators in the past could be explained if postmortem...... and a filamentous surface coat about 60 nm thick covered the interfenestral domains of the endothelial cell. Based on these purely morphological data, we dare to suggest that the fenestral plugs are the primary site of the glomerular filtration barrier - albeit highly speculative, nevertheless a logical location...... - and consequently that the glomerular filtration process is a 'tangential-flow' as opposed to a 'dead-end' filtration process. A tangential-flow filtration would minimize 'clogging' and 'concentration polarization' in the 'filter'....

Aluminium - Cobalt-Pillared Clay for Dye Filtration Membrane

Science.gov (United States)

Darmawan, A.; Widiarsih

2018-04-01

The manufacture of membrane support from cobalt aluminium pillared clay has been conducted. This research was conducted by mixing a clay suspension with pillared solution prepared from the mixture of Co(NO3)2.6H2O and AlCl3.6H2O. The molar ratio between Al and Co was 75:25 and the ratio of [OH-]/[metal] was 2. The clay suspension was stirred for 24 hours at room temperature, filtered and dried. The dried clay was then calcined at 200°C, 300°C and 400°C with a ramp rate of 2°C/min. Aluminium-cobalt-pillared clay was then characterized by XRD and GSA and moulded become a membrane support for subsequent tests on dye filtration. The XRD analysis showed that basal spacing (d 001) value of aluminium cobalt was 19.49 Å, which was higher than the natural clay of 15.08Å however, the basal spacing decreased with increasing calcination temperature. The result of the GSA analysis showed that the pore diameter of the aluminium cobalt pillared clay membrane was almost the same as that of natural clay that were 34.5Å and 34.2Å, respectively. Nevertheless, the pillared clay has a more uniform pore size distribution. The results of methylene blue filtration measurements demonstrated that the membrane filter support could well which shown by a clear filtrate at all concentrations tested. The value of rejection and flux decreased with the increasing concentration of methylene blue. The values of dye rejection and water flux reached 99.89% and 5. 80 x 10-6 kg min-1, respectively but they decreased with increasing concentration of methylene blue. The results of this study indicates that the aluminium-pillared clay cobalt could be used as membrane materials especially for ultrafiltration.

Statistical data filtration in neutron coincidence counting

International Nuclear Information System (INIS)

Beddingfield, D.H.; Menlove, H.O.

1992-11-01

We assessed the effectiveness of statistical data filtration to minimize the contribution of matrix materials in 200-ell drums to the nondestructive assay of plutonium. Those matrices were examined: polyethylene, concrete, aluminum, iron, cadmium, and lead. Statistical filtration of neutron coincidence data improved the low-end sensitivity of coincidence counters. Spurious data arising from electrical noise, matrix spallation, and geometric effects were smoothed in a predictable fashion by the statistical filter. The filter effectively lowers the minimum detectable mass limit that can be achieved for plutonium assay using passive neutron coincidence counting

Oviposition Attractancy of Bacterial Culture Filtrates: response of Culex quinquefasciatus

Directory of Open Access Journals (Sweden)

S Poonam

2002-04-01

Full Text Available Oviposition attractants could be used for monitoring as well as controlling mosquitoes by attracting them to lay eggs at chosen sites. In the present study, culture filtrates of seven bacterial species were tested for their attractancy against gravid females of Culex quinquefasciatus. When their oviposition active indices (OAI were studied, the culture filtrates of Bacillus cereus and Pseudomonas fluorescens exhibited oviposition attractancy (OAI = >0.3 at 100 ppm and the OAI were respectively 0.70 and 0.47. Culture filtrates of B. thuringiensis var. israelensis (wild type, B. t. var. israelensis (mutant and B. sphaericus showed attractancy at 2000 ppm with OAI of respectively 0.71, 0.59 and 0.68. However, the OAI of B. megaterium as well as Azospirillum brasilense was 0.13 (at 2000 ppm, which was less than 0.3 required to be considered them as attractants. When the oviposition attractancy of the bacterial culture filtrates were compared with that of a known oviposition attractant, p-cresol (at 10 ppm, the culture filtrates of B. t. var. israelensis (wild type and B. cereus were found to be more active than p-cresol, respectively with 64.2 and 54.3% oviposition.

Rapid decline in glomerular filtration rate during the first weeks following heart transplantation

DEFF Research Database (Denmark)

Hornum, M; Andersen, Mads Jønsson; Gustafsson, F

2011-01-01

We hypothesized that a decrease in renal function is seen immediately after heart transplantation (HTX) with little recovery over time. Twelve consecutive patients had their glomerular filtration rate (GFR) measured using (51)Cr-ethylenediaminetetraacetic acid (EDTA) measured GFR (mGFR) before tr...... risk factor for the rapid and sustained decrease in renal function supports the need for more studies on renoprotective strategies immediately after HTX....

Field Demonstration of Fuel Crud Filtration System at Ulchin Plant

International Nuclear Information System (INIS)

Kang, Duk-Won; Lee, Doo-Ho; Park, Jong-Youl; Choi, In-Kyu

2007-01-01

Crud deposited onto the fuel assemblies in nuclear power plants was not a serious problem until an upper core flux depression named Axial Offset Anomaly (AOA) was found at Callaway, USA in 1989. Though the mechanism of an AOA is not completely understood, crud is believed to be a key component of initiating AOA. After the sufficient amount of corrosion products in the reactor cooling system are deposited on the fuel clad by a sub-cooled nucleate boiling, boron is adsorbed in the crud. Thus a measurable reduction in the neutron flux occurs which causes an AOA problem. A filtration system has been developed to remove the fuel crud from irradiated fuel assemblies for mitigating the axial offset anomaly under a technical cooperation agreement with DEI (Dominion Engineering Inc.). This filtration system with a fuel cleaning fixture was successfully demonstrated at Ulchin plant unit 2. Within several minutes, detachable crud deposits were effectively removed from the clad surfaces of the fuel assembly. Also, to characterize the crud particles for each fuel assembly, a small crud sampling device and radiation monitor devices were connected to the filtration system during the cleaning operation. In this study, we completed a functional test and demonstration of an ultrasonic fuel cleaning system by using four spent fuel assemblies. It took only 5 minutes to remove the fuel crud from each fuel assembly. In addition, collective dose rates indicated an average of 8 R/Hr per assembly

Determination of filtrations and permeability of an earth dam

International Nuclear Information System (INIS)

Gomez, H.R.; Baro, G.B.; Gillen, Ricardo.

1975-11-01

The aim of this work was to measure with the aid of a radioactive tracer the speed flow of the water filtrating from Sumampa Dam in northeastern Catamarca, while being in operation, and with these data determine if the actual permeability corresponds to the projected one. Iodine-131 was used as tracer and periodical samples were taken from the down stream water in order to determine its activity concentration. In previous perforations ionic interchange resines were used so as to measure simultaneously the fixed Iodine-131. The permeability of the dam was calculated from the obtained speed based on time-concentration curves and applying Darcy formulas for permeability. (author) [es

A real-life example of choosing an inherently safer process option

International Nuclear Information System (INIS)

Study, Karen

2007-01-01

While choosing an inherently safer alternative may seem straightforward, sometimes what seems to be the most obvious alternative may not provide the best risk reduction. The process designer must maintain a broad perspective to be able to recognize all potential hazards when evaluating design options. All aspects of operation such as start-up, shut-down, utility failure, as well as normal operation should be considered. Choosing the inherently safer option is best accomplished early in the option selection phase of a project; however, recycle back to the option selection phase may be needed if an option is not thoroughly evaluated early in the process. In this paper, a project to supply ammonia to a catalytic reactor will be reviewed. During the course of the project, an 'inherently safer' alternative was selected and later discarded due to issues uncovered during the detail design phase. The final option chosen will be compared to (1) the original design and (2) the initial 'inherently safer' alternative. The final option was inherently safer than both the original design and the initial 'inherently safer' alternative even though the design team initially believed that it would not be

Reliability of single kidney glomerular filtration rate measured by a 99mTc-DTPA gamma camera technique

International Nuclear Information System (INIS)

Rehling, M.; Moller, M.L.; Jensen, J.J.; Thamdrup, B.; Lund, J.O.; Trap-Jensen, J.

1986-01-01

The reliability of a previously published method for determination of single kidney glomerular filtration rate (SKGFR) by means of technetium-99m-diethylenetriaminepenta-acetate (99mTc-DTPA) gamma camera renography was evaluated. The day-to-day variation in the calculated SKGFR values was earlier found to be 8.8%. The technique was compared to the simultaneously measured renal clearance of inulin in 19 unilaterally nephrectomized patients with GFR varying from 11 to 76 ml/min. The regression line (y = 1.04 X -2.5) did not differ significantly from the line of identity. The standard error of estimate was 4.3 ml/min. In 17 patients the inter- and intraobserver variation of the calculated SKGFR values was 1.2 ml/min and 1.3 ml/min, respectively. In 21 of 25 healthy subjects studied (age range 27-29 years), total GFR calculated from the renograms was within an established age-dependent normal range of GFR

Filtration device for active effluents

International Nuclear Information System (INIS)

Guerin, M.; Meunier, G.

1994-01-01

Among the various techniques relating to solid/liquid separations, filtration is currently utilized for treating radioactive effluents. After testing different equipments on various simulated effluents, the Valduc Center has decided to substitute a monoplate filter for a rotative diatomite precoated filter

Interdependency control : compensation strategies for the inherent vulnerability of critical infrastructure networks

International Nuclear Information System (INIS)

Mao, D.; Sotoodeh, M.; Monu, K.; Marti, J.R.; Srivastava, K.D.

2009-01-01

Today's increasingly interacting national critical infrastructures (NCIs) can tolerate most stochastic local disturbances. However, they are extremely fragile under global disturbances, as the latter may either push the whole system into a critical state or reveal many unexpected hidden interdependencies, inducing or triggering cascading failures among all possible layers. This robust yet fragile duality is an inherent vulnerability of modern infrastructures. It is therefore expected that weather-related disasters will be more frequent under a changing climate. This paper proposed an interdependency control strategy (ICS) that would maintain the survival of the most critical services, and compensate for this inherent vulnerability during emergency states. The paper also proposed a generalized adjacency matrix (GAM) to represent the physical interdependencies intra/inter of various infrastructure networks. The vulnerable section in the network can be identified, based on computed results of GAM, number of islands in the network, and influence domain(s) of each component. These features render ICS more effective and convincing. Last, the paper proposed a survivability index for isolated sub-networks and described relevant measures for improving this index during the four phases of emergency management. It was concluded that the proposed strategy is an effective means to reduce the inherent vulnerability and increase the resiliency of these critical infrastructures networks. 20 refs., 5 figs

SU-D-209-02: Percent Depth Dose Curves for Fluoroscopic X-Ray Beam Qualities Incorporating Copper Filtration

Energy Technology Data Exchange (ETDEWEB)

Wunderle, K [Cleveland Clinic Foundation, Cleveland, OH (United States); Wayne State University School of Medicine, Detroit, MI (United States); Godley, A; Shen, Z; Dong, F [Cleveland Clinic Foundation, Cleveland, OH (United States); Rakowski, J [Wayne State University School of Medicine, Detroit, MI (United States)

2016-06-15

Purpose: The purpose of this investigation was to quantify percent depth dose (PDD) curves for fluoroscopic x-ray beam qualities incorporating added copper filtration. Methods: A PTW (Freiburg, Germany) MP3 water tank was used with a Standard Imaging (Middleton, WI) Exradin Model 11 Spokas Chamber to measure PDD curves for 60, 80, 100 and 120 kVp x-ray beams with copper filtration ranging from 0.0–0.9 mm at 22cm and 42cm fields of view from 0 to 150 mm of water. A free-in-air monitor chamber was used to normalize the water tank data to fluctuations in output from the fluoroscope. The measurements were acquired on a Siemens (Erlangen, Germany) Artis ZeeGo fluoroscope. The fluoroscope was inverted from the typical orientation providing an x-ray beam originating from above the water tank. The water tank was positioned so that the water level was located at 60cm from the focal spot; which also represents the focal spot to interventional reference plane distance for that fluoroscope. Results: PDDs for 60, 80, 100, and 120 kVp with 0 mm of copper filtration compared well to previously published data by Fetterly et al. [Med Phys, 28, 205 (2001)] for those beam qualities given differences in fluoroscopes, geometric orientation, type of ionization chamber, and the water tank used for data collection. PDDs for 60, 80, 100, and 120 kVp with copper filtration were obtained and are presented, which have not been previously investigated and published. Conclusion: The equipment and processes used to acquire the reported data were sound and compared well with previously published data for PDDs without copper filtration. PDD data for the fluoroscopic x-ray beams incorporating copper filtration can be used as reference data for estimating organ or soft tissue dose at depth involving similar beam qualities or for comparison with mathematical models.

Mixture based outlier filtration

Czech Academy of Sciences Publication Activity Database

Pecherková, Pavla; Nagy, Ivan

2006-01-01

Roč. 46, č. 2 (2006), s. 30-35 ISSN 1210-2709 R&D Projects: GA MŠk 1M0572; GA MDS 1F43A/003/120 Institutional research plan: CEZ:AV0Z10750506 Keywords : data filtration * system modelling * mixture models Subject RIV: BD - Theory of Information http://library.utia.cas.cz/prace/20060165.pdf

Glomerular filtration and tubular secretion of MAG-3 in the rat kidney

International Nuclear Information System (INIS)

Mueller-Suur, R.M.; Mueller-Suur, C.

1989-01-01

Technetium-99m mercaptoacetyltriglycine (MAG-3) has recently been introduced as a new radiopharmaceutical for dynamic renal scintigraphy. To elucidate the mechanism of renal excretion, micropuncture experiments were performed in rat kidneys for direct measurements of glomerular filtration and tubular secretory capacity. Fluid of Bowman space was collected from superficial glomeruli and analyzed for its contents of [99mTc]MAG-3, [125I]hippurate and [3H]inulin during constant infusion of these compounds. The ratio of activity of ultrafiltrate to that of arterial plasma was 0.23 for MAG-3, 0.68 for hippurate and 1.04 for inulin which demonstrates that the filtrated amount of MAG-3 is only 23% of that of inulin, presumably because of higher plasma protein binding which was also measured in vitro and found to be 80 +/- 1.5% for MAG-3 and 32 +/- 2% for [125I]hippurate. Proximal and distal tubules were also micropunctured and their tubular fluid as well as the final urine analyzed for the activity of hippurate and MAG-3. The tubular fluid to plasma ratio values along the nephron and in the final urine were all lower for MAG-3 than for hippurate, indicating a lower secretory capacity. From measurements of whole renal clearance, GFR and plasma protein binding the filtered amount of MAG-3 was 0.26 and of hippurate 0.87 ml/min.g kidney weight (p less than 0.001) and the secreted amount 2.01 and 2.38 ml/min.g kidney weight (p less than 0.05), respectively. We conclude that MAG-3 is predominantly excreted by tubular secretion and that the lower renal clearance of MAG-3 as compared with that of hippurate is a result both of a substantially decreased glomerular filtration and of a lower tubular secretion

Numerical Solutions of Mechanical Turbulent Filtration Equation Used in Mechatronics and Micro Mechanic

OpenAIRE

Hassan Fathabadi

2013-01-01

In this study, several novel numerical solutions are presented to solve the turbulent filtration equation and its special case called “Non-Newtonian mechanical filtration equation”. The turbulent filtration equation in porous media is a very important equation which has many applications to solve the problems appearing especially in mechatronics, micro mechanic and fluid mechanic. Many applied mechanical problems can be solved using this equation. For example, non-Newtonian mechanical filtrat...

Modeling of Filtration Processes—Microfiltration and Depth Filtration for Harvest of a Therapeutic Protein Expressed in Pichia pastoris at Constant Pressure

Directory of Open Access Journals (Sweden)

Muthukumar Sampath

2014-12-01

Full Text Available Filtration steps are ubiquitous in biotech processes due to the simplicity of operation, ease of scalability and the myriad of operations that they can be used for. Microfiltration, depth filtration, ultrafiltration and diafiltration are some of the most commonly used biotech unit operations. For clean feed streams, when fouling is minimal, scaling of these unit operations is performed linearly based on the filter area per unit volume of feed stream. However, for cases when considerable fouling occurs, such as the case of harvesting a therapeutic product expressed in Pichia pastoris, linear scaling may not be possible and current industrial practices involve use of 20–30% excess filter area over and above the calculated filter area to account for the uncertainty in scaling. In view of the fact that filters used for harvest are likely to have a very limited lifetime, this oversizing of the filters can add considerable cost of goods for the manufacturer. Modeling offers a way out of this conundrum. In this paper, we examine feasibility of using the various proposed models for filtration of a therapeutic product expressed in Pichia pastoris at constant pressure. It is observed that none of the individual models yield a satisfactory fit of the data, thus indicating that more than one fouling mechanism is at work. Filters with smaller pores were found to undergo fouling via complete pore blocking followed by cake filtration. On the other hand, filters with larger pores were found to undergo fouling via intermediate pore blocking followed by cake filtration. The proposed approach can be used for more accurate sizing of microfilters and depth filters.

Non-filtration method of processing uranium ores

International Nuclear Information System (INIS)

Laskorin, B.N.; Vodolazov, L.I.; Tokarev, N.N.; Vyalkov, V.I.; Goldobina, V.A.; Gosudarstvennyj Komitet po Ispol'zovaniyu Atomnoj Ehnergii SSSR, Moscow)

1977-01-01

The development of the non-filtration sorption method has lead to procedures of the sorption leaching and the extraction desorption, which have made it possible to intensify the processing of uranium ores and to improve greatly the technical and economic indexes by eliminating the complex method of multiple filtration and re-pulping of cakes. This method makes it possible to involve more poor uranium raw materials, at the same time extracting valuable components such as molybdenum, vanadium, copper, etc. Considerable industrial experience has been acquired in the sorption of dense pulp with a solid-to-liquid phase ratio of 1:1. This has led to a plant production increase of 1.5-3.0 times, an increase of uranium extraction by 5-10%, a two- to- three-fold increase of labour capacity of the main workers, and to a several-fold decrease of reagents, auxiliary materials, electric energy and vapour. This non-filtration method is a continuous process in all its phases thanks to the use of high-yield and high-power equipment for high-density pulps. (author)

The Application of Homogenate and Filtrate from Baltic Seaweeds in Seedling Growth Tests

Directory of Open Access Journals (Sweden)

Izabela Michalak

2017-02-01

Full Text Available Algal filtrate and homogenate, obtained from Baltic seaweeds, were applied in seedling growth tests. Radish seeds were used in order to assess algal products phytotoxicity and their biostimulant effect on growth and nutrient uptake. Algal filtrate, at concentrations ranging from 5.0% to 100% was used for seed soaking and as a liquid biostimulant (soil and foliar application. Algal homogenate was developed for seed coating. Algal filtrate and homogenate were also enriched with Zn(II ions in order to examine the influence on metal ion complexation. The optimal doses of algal filtrate and homogenate, as well as soaking time were established. Multi-elemental analyses of the raw biomass, filtrate, homogenate, and radish were also performed using ICP-OES (Inductively Coupled Plasma—Optical Emission Spectrometry. The best results in terms of seedlings’ length and weight were obtained using clear filtrate at a concentration of 50% applied to the soil and for homogenate applied at a dose of 50 mg/g of seeds. Clear filtrate at a concentration of 50% used for seed soaking for one hour showed the best results. The applied algal products increased the content of elements in seedlings. Among the tested products, a concentration of 50% algal filtrate is recommended for future pot and field experiments.

Air filtration media from electrospun waste high-impact polystyrene fiber membrane

Science.gov (United States)

Zulfi, Akmal; Miftahul Munir, Muhammad; Hapidin, Dian Ahmad; Rajak, Abdul; Edikresnha, Dhewa; Iskandar, Ferry; Khairurrijal, Khairurrijal

2018-03-01

Nanofiber membranes were synthesized from waste high-impact polystyrene (HIPS) using electrospinning method and then applied as air filtration media. The waste HIPS precursor solution with the concentration of 20 wt.% was prepared by dissolving waste HIPS into the mixture of d-limonene and DMF solvents. Beaded or fine nanofibers could be achieved by adjusting the ratio of solvents mixture (d-limonene and DMF). Using the ratios of solvents (d-limonene: DMF) of 3:1, 1:1, and 1:3, it was obtained beaded HIPS nanofibers with the average diameter of 272 nm, beaded HIPS nanofibers with the average diameter of 937, and fine HIPS nanofibers with the average diameter of 621 nm, respectively. From the FTIR spectral analysis, it was found that the FTIR peaks of the HIPS nanofiber membranes are the same as those of the cleaned waste HIPS and there are no FTIR peaks of DMF and d-limonene solvents. These findings implied that the electrospinning process allows the recycling of waste HIPS into HIPS nanofibers without any trapped solvent phases or apparent degradation of the original material. From the contact angle measurement, it was confirmed that the HIPS nanofiber membranes are hydrophobic and the presence of the beads in the HIPS nanofiber membranes varies their contact angles. From the air-filtration test, it was shown that the fiber morphology (beaded or fine nanofibers) considerably affects the filtration performance of the membranes. The presence of beads increased the distance between the fibers so that the pressure drop decreased. Moreover, the basis weight of the membrane greatly affected the filtration efficiency. The HIPS nanofiber membrane with the basis weight of 12.22 g m‑2 had the efficiency greater than 99.999%, which was equivalent to that of the HEPA filter.

Inherently safe technologies-chemical and nuclear

International Nuclear Information System (INIS)

Weinberg, A.M.

1984-01-01

Probabilistic risk assessments show an inverse relationship between the likelihood and the consequences of nuclear and chemical plant accidents, but the Bhopal accident has change public complacency about the safety of chemical plants to such an extent that public confidence is now at the same low level as with nuclear plants. The nuclear industry's response was to strengthen its institutions and improve its technologies, but the public may not be convinced. One solution is to develop reactors which do not depend upon the active intervention of humans of electromechanical devices to deal with emergencies, but which have physical properties that limit the possible temperature and power of a reactor. The Process Inherent Ultimately Safe and the modular High-Temperature Gas-Cooled reactors are two possibilities. the chemical industry needs to develop its own inherently safe design precepts that incorporate smallness, safe processes, and hardening against sabotage. 5 references

Process analysis and optimization of direct horizontal-row roughing filtration

NARCIS (Netherlands)

Ahsan, T.

1995-01-01

There is a growing demand for appropriate water treatment technology for towns and small cities in developing countries. This study developed a pretreatment technology for highly turbid river water, called direct horizontal-flow roughing filtration, by combining the principles of direct filtration

Filtration of Nanoparticles: Evolution of Cake Structure and Pressure-Drop

DEFF Research Database (Denmark)

Elmøe, Tobias Dokkedal; Tricoli, Antonio; Grunwaldt, Jan-Dierk

2009-01-01

The detailed three-dimensional accumulation of deposits and the build-up of pressuredrop during filtration of compressible gases laden with nanoparticles (diameter dp=50 nm) through capillaries (1–4 micron radius) was investigated by Langevin dynamics (LD) at Peclet number, Pe, 0.01–10. At low Pe...... with constant solid volume fraction began to form, accompanied with build-up of pressuredrop which was in excellent agreement with classic cake filtration theory. An expression for the solid volume fraction of the cake (fsd,c) was obtained as a sole function of Pe. In addition, the filtration efficiency became...... 1 after clogging, since the cake acts as a perfectly efficient filter. Penetration of nanoparticles takes place until the onset of cake filtration at high Pe (1–10) while for smaller ones (0.01–0.1) it is negligible at the employed capillary radii and length (10 micron). Analytical expressions...

Demonstration of creep during filtration

DEFF Research Database (Denmark)

Christensen, Morten Lykkegaard; Bugge, Thomas Vistisen; Kirchheiner, Anders Løvenbalk

The classical filtration theory assumes a unique relationship between the local filter cake porosity and the local effective pressure. For a number of compressible materials, it has however been observed that during the consolidation stage this may not be the case. It has been found...... that the production of filtrate also depends on the characteristic time for the filter cake solids to deform. This is formulated in the Terzaghi-Voigt model in which a secondary consolidation is introduced. The secondary consolidation may be visualized by plots of the relative cake deformation (U) v.s. the square...... root of time. Even more clearly it is demonstrated by plotting the liquid pressure at the cake piston interface v.s. the relative deformation (to be shown). The phenomenon of a secondary consolidation processes is in short called creep. Provided that the secondary consolidation rate is of the same...

Adequacy and adjustment of electromechanical elements of a X radiation generator for automation of system of additional filtration

International Nuclear Information System (INIS)

Alves Junior, Iremar; Santos, Lucas dos; Potiens, Maria da Penha A.; Vivolo, Vitor

2011-01-01

This paper dimensioned the filter wheel components and the adequacy of additional filtrations for the implantation of the OTW automated system with complete replacement of previous used filtration by new set of machine-made filters to be used as the qualities already implanted at the Instrument Calibration Laboratory of the IPEN, Sao Paulo, Brazil. In the sequence, it was performed the measurements of kerma i the air in each quality to be used as reference values

Magnetic-seeding filtration

Energy Technology Data Exchange (ETDEWEB)

DePaoli, D.W.; Tsouris, C. [Oak Ridge National Lab., TN (United States); Yiacoumi, Sotira

1997-10-01

Magnetic-seeding filtration is a technology under development for the enhanced removal of magnetic and non-magnetic particulates from liquids. This process involves the addition of a small amount of magnetic seed particles (such as naturally occurring iron oxide) to a waste suspension, followed by treatment with a magnetic filter. Non-magnetic and weakly magnetic particles are made to undergo nonhomogeneous flocculation with the seed particles, forming flocs of high magnetic susceptibility that are readily removed by a conventional high-gradient magnetic filter. This technology is applicable to a wide range of liquid wastes, including groundwater, process waters, and tank supernatants. Magnetic-seeding filtration may be used in several aspects of treatment, such as (1) removal of solids, particularly those in the colloidal size range that are difficult to remove by conventional means; (2) removal of contaminants by precipitation processes; and (3) removal of contaminants by sorption processes. Waste stream characteristics for which the technology may be applicable include (1) particle sizes ranging from relatively coarse (several microns) to colloidal particles, (2) high or low radiation levels, (3) broad-ranging flow rates, (4) low to moderate solids concentration, (5) cases requiring high decontamination factors, and (6) aqueous or non-aqueous liquids. At this point, the technology is at the bench-scale stage of development; laboratory studies and fundamental modeling are currently being employed to determine the capabilities of the process.

Magnetic-seeding filtration

International Nuclear Information System (INIS)

DePaoli, D.W.; Tsouris, C.; Yiacoumi, Sotira.

1997-01-01

Magnetic-seeding filtration is a technology under development for the enhanced removal of magnetic and non-magnetic particulates from liquids. This process involves the addition of a small amount of magnetic seed particles (such as naturally occurring iron oxide) to a waste suspension, followed by treatment with a magnetic filter. Non-magnetic and weakly magnetic particles are made to undergo nonhomogeneous flocculation with the seed particles, forming flocs of high magnetic susceptibility that are readily removed by a conventional high-gradient magnetic filter. This technology is applicable to a wide range of liquid wastes, including groundwater, process waters, and tank supernatants. Magnetic-seeding filtration may be used in several aspects of treatment, such as (1) removal of solids, particularly those in the colloidal size range that are difficult to remove by conventional means; (2) removal of contaminants by precipitation processes; and (3) removal of contaminants by sorption processes. Waste stream characteristics for which the technology may be applicable include (1) particle sizes ranging from relatively coarse (several microns) to colloidal particles, (2) high or low radiation levels, (3) broad-ranging flow rates, (4) low to moderate solids concentration, (5) cases requiring high decontamination factors, and (6) aqueous or non-aqueous liquids. At this point, the technology is at the bench-scale stage of development; laboratory studies and fundamental modeling are currently being employed to determine the capabilities of the process

ACTINIDE REMOVAL PROCESS SAMPLE ANALYSIS, CHEMICAL MODELING, AND FILTRATION EVALUATION

Energy Technology Data Exchange (ETDEWEB)

Martino, C.; Herman, D.; Pike, J.; Peters, T.

2014-06-05

Filtration within the Actinide Removal Process (ARP) currently limits the throughput in interim salt processing at the Savannah River Site. In this process, batches of salt solution with Monosodium Titanate (MST) sorbent are concentrated by crossflow filtration. The filtrate is subsequently processed to remove cesium in the Modular Caustic Side Solvent Extraction Unit (MCU) followed by disposal in saltstone grout. The concentrated MST slurry is washed and sent to the Defense Waste Processing Facility (DWPF) for vitrification. During recent ARP processing, there has been a degradation of filter performance manifested as the inability to maintain high filtrate flux throughout a multi-batch cycle. The objectives of this effort were to characterize the feed streams, to determine if solids (in addition to MST) are precipitating and causing the degraded performance of the filters, and to assess the particle size and rheological data to address potential filtration impacts. Equilibrium modelling with OLI Analyzer{sup TM} and OLI ESP{sup TM} was performed to determine chemical components at risk of precipitation and to simulate the ARP process. The performance of ARP filtration was evaluated to review potential causes of the observed filter behavior. Task activities for this study included extensive physical and chemical analysis of samples from the Late Wash Pump Tank (LWPT) and the Late Wash Hold Tank (LWHT) within ARP as well as samples of the tank farm feed from Tank 49H. The samples from the LWPT and LWHT were obtained from several stages of processing of Salt Batch 6D, Cycle 6, Batch 16.

Modeling of filtration of 2-types particles suspension in a porous medium

Directory of Open Access Journals (Sweden)

Galaguz Yuri

2017-01-01

Full Text Available The filtration problem describes the process of concreting loose soil with a liquefied concrete solution. The filtration of 2-types particles suspension in a homogeneous porous medium with a size-exclusion particles retention mechanism is considered. The difference in the filtration coefficients of 2-types particles leads to the separation of the filtration domain into two zones, in one of which two types of particles are deposited and in another – only particles of one type are deposited. In this paper, the mobile boundary of two zones is calculated, and numerical solution of the problem is calculated.

Inherent and passive safety measures in accelerator driven systems: a safety strategy for ADS

International Nuclear Information System (INIS)

Maschek, W.; Rineiski, A.; Morita, K.; Flad, M.

2001-01-01

The efficiency of Accelerator Driven Systems (ADSs) for the transmutation and incineration of nuclear waste is strongly related to the utilization of so-called dedicated fuels. In the ideal case these fuels should consist of pure TRUs without fertile materials as 238 U or 232 Th to achieve highest incineration/transmutation rates. Dedicated fuels still have to be developed and programs are under way for their fabrication, irradiation and testing. These fertile-free fuels may suffer from deteriorated thermal or thermo-mechanical properties, as a reduced melting point, reduced thermal conductivity or even thermal instability. First analyses have shown that the use of dedicated fuels may lead to a strong deterioration of the safety parameters of the reactor core as e.g. the void worth, the Doppler or the kinetics quantities as neutron generation time and β eff . In addition, a dedicated core may contain multiple ''critical'' fuel masses, resulting in a considerable recriticality potential. Current knowledge on these dedicated fuels suggests that ''critical'' reactors may not be feasible, because of safety reasons. However, for ADSs, the salient hope has been promoted that due to the subcriticality of the system the poor safety features of such fuels could be coped with. Analyses are presented which show potential safety problems for such dedicated cores. Respecting the results of these analyses a safety strategy is proposed along the lines of defense approach in analogy with ideas formerly developed for fast reactors. Inherent and passive safety measures are integrated into the various defense lines. (author)

Renin-angiotensin system antagonists, glomerular filtration rate and blood pressure

Directory of Open Access Journals (Sweden)

D.D. Ivanov

2018-02-01

Full Text Available The article deals with the mModern data on the influence of renin-angiotensin system blockers on the glomerular filtration rate, the level of arterial pressure and the outcome of chronic kidney disease. The strategy of  rennin-angiotensine blockade is offered to be changed depending on the criteria va­lues of glomerular filtration rate: a combination of inhibitors of angiotensin-converting enzyme + angiotensin receptors blo­ckers, monotherapy and drug withdrawal in glomerular filtration rate under 15–30 ml/min/m2. The formula BRIMONEL for treatment of chronic kidney disease is given.

Ultrasonic filtration of industrial chemical solutions

Science.gov (United States)

Cosma, T.

1974-01-01

The practical results obtained as a result of filtering industrial chemical solutions under continuous flow conditions with the aid of an ultrasonic filter are presented. The main part of the assembly consists of an ultrasonic generator with an output power of about 400 W and the filtration assembly, in which there is a magnetostrictive amplifier constructed for 20.5 kHz. In addition to ensuring a continuous flow of filtered solution, ultrasonic filters can be replaced or cleaned at intervals of time that are 8-10 times greater than in the case of mechanical filters. They yield considerably better results as far as the size of the filtered particles is concerned. The parameters on which filtration quality depends are also presented.

Radioimmunological determination of parathormone peptides in the plasma before and after gel filtration in hyperparathyroidic patients

International Nuclear Information System (INIS)

Juengst, U.

1983-01-01

Plasmas from different patients suffering from secondary renal hyperparathyroidism and from one patient suffering from primary hyperparathyroidism owing to a parathyroid adenoma, were studied and parathormone concentrations (total IPTH) were determined radio-immunologically. Plasmas were gel-filtered subsequently. Gelfiltration allows to separate intact PTH from PTH fragments which also occur in the plasma. These fragments also react with the antisera used in the PTH-radio-immuno-assay; thus it was possible to determine only the concentration of intact PTH after gel filtration. In patients in whose unfiltered plasma strongly increased PTH values had been measured (more than 100 pmol hPTH/l plasma), only 10 to 40% of total immunoreactivity were taken up by intact parathormone after gel filtration. Histological findings of iliac crest biopsies revealed marked changes corresponding to the increased concentration of biologically active hormone. Whereas unfiltered plasma revealed slightly increased PTH measurement values (below 100 pmol hPTH/l), 60 to 75% of total immuno reactivity was taken up by the intact hormone after gel filtration. Correspondingly, histological changes of the skeleton were less marked. Apparently, there is a correlation - though not a linear one - between total IPTH and the absolute concentration of intact PTH. If increased PTH values are measured with antiserum S478, it may be assumed in general that the concentration of intact and biologically active PTH has increased as well. (orig./MG) [de

C-018H LERF filtration test plan. Revision 1

International Nuclear Information System (INIS)

Moberg, T.P.; King, C.V.

1994-01-01

The following outlines the plan to test the polymeric backwash filtration system at the LERF. These tests will determine if the ETF filter design is adequate. If the tests show that the design is adequate, the task will be complete. If the tests show that the technology is inadequate, it may be necessary to perform further tests to qualify other candidate filtration technologies (e.g., polymeric tubular ultrafiltration, centrifugal ultrafiltration). The criteria to determine the success or failure of the backwash filter will be based on the system's ability to remove the bacteria and inorganic contaminants from the evaporator process condensate. The tests are designed to qualify the design basis of the filtration technology that will be used in the ETF

C-018H LERF filtration test plan. Revision 1

Energy Technology Data Exchange (ETDEWEB)

Moberg, T.P.; King, C.V.

1994-08-26

The following outlines the plan to test the polymeric backwash filtration system at the LERF. These tests will determine if the ETF filter design is adequate. If the tests show that the design is adequate, the task will be complete. If the tests show that the technology is inadequate, it may be necessary to perform further tests to qualify other candidate filtration technologies (e.g., polymeric tubular ultrafiltration, centrifugal ultrafiltration). The criteria to determine the success or failure of the backwash filter will be based on the system`s ability to remove the bacteria and inorganic contaminants from the evaporator process condensate. The tests are designed to qualify the design basis of the filtration technology that will be used in the ETF.

Increased kidney size, glomerular filtration rate and renal plasma flow in short-term insulin-dependent diabetics

DEFF Research Database (Denmark)

Christiansen, JS; Gammelgaard, J; Frandsen, M

1981-01-01

Glomerular filtration rate (GFR), renal plasma flow (RPF) and kidney volume were measured in thirteen male subjects (mean age 30 years) with short-term insulin-dependent diabetes (mean duration of disease 2.4 years) and fourteen normal male subjects (mean age 29 years). GFR and RPF were measured...

The usage of filtration as fulfillment of acceptable indoor and optimal energy management

International Nuclear Information System (INIS)

Burroughs, H.E.

1993-01-01

The role of filtration is a significant factor in the prevention and mitigation of indoor air quality problems. ASHRAE Standard 62-89. Ventilation for Acceptable Indoor Air Quality, makes broad and non-specific references to filtration. This paper provides guidelines for the usage of filtration as a means of fulfillment of the Standard's requirements. The paper also references the specific authorities as iterated in the Standard. The discussion will include the usage of filtration in treating contaminated outside air, protection of equipment and systems, protection of occupants, reduction of ventilation air, and source control. The reduction of ventilation air through filtration has significant and positive energy management benefits. Other energy benefits accrue from clean heat exchange surfaces

Expanded uncertainty estimation methodology in determining the sandy soils filtration coefficient

Science.gov (United States)

Rusanova, A. D.; Malaja, L. D.; Ivanov, R. N.; Gruzin, A. V.; Shalaj, V. V.

2018-04-01

The combined standard uncertainty estimation methodology in determining the sandy soils filtration coefficient has been developed. The laboratory researches were carried out which resulted in filtration coefficient determination and combined uncertainty estimation obtaining.

Posttest analysis of the FFTF inherent safety tests

International Nuclear Information System (INIS)

Padilla, A. Jr.; Claybrook, S.W.

1987-01-01

Inherent safety tests were performed during 1986 in the 400-MW (thermal) Fast Flux Test Facility (FFTF) reactor to demonstrate the effectiveness of an inherent shutdown device called the gas expansion module (GEM). The GEM device provided a strong negative reactivity feedback during loss-of-flow conditions by increasing the neutron leakage as a result of an expanding gas bubble. The best-estimate pretest calculations for these tests were performed using the IANUS plant analysis code (Westinghouse Electric Corporation proprietary code) and the MELT/SIEX3 core analysis code. These two codes were also used to perform the required operational safety analyses for the FFTF reactor and plant. Although it was intended to also use the SASSYS systems (core and plant) analysis code, the calibration of the SASSYS code for FFTF core and plant analysis was not completed in time to perform pretest analyses. The purpose of this paper is to present the results of the posttest analysis of the 1986 FFTF inherent safety tests using the SASSYS code

Determination of representative renal depth for accurate attenuation corred in measurement of glomerular filtration rate in transplanted kidney

International Nuclear Information System (INIS)

Oh, Soon Nam; Kim, Sung Hoon; Rha, Sung Eun; Chung, Yong An; Yoo, Ie Ryung; Sohn, Hyung Sun; Lee, Sung Young; Chung, Soo Kyo

2002-01-01

To measure reliable glomerular filtration rate by using the representative values of transplanted renal depths, which are measured with ultrasonography. We included 54 patients (26 men, 28 women), with having both renal scintigraphy and ultrasonography after renal transplantation. We measured DFR with Gates' method using the renal depth measured by ultrasonography, and median and mean ones in each patient. We compared GFR derived from ultrasonography-measured renal depth with GFR derived from median and mean renal depths. The correlation coefficients were obtained among GFR derived from ultrasonography-measured renal depths, median and mean renal depth under linear regression analysis. We determined whether GFR derived from median or mean renal depth could substitute GFR derived from ultrasonography-measured renal depth with Bland-Altman method. We analyze the expected errors of the GFR using representative renal depth in terms of age, sex, weight, height, creatinine value, and body surface. The transplanted renal depths range from 3.20 cm to 5.96 cm. The mean value and standard deviation of renal depths measured by ultrasonography are 4.09±0.65 cm in men, and 4.24±0.78 cm in women. The median value of renal depths measured by ultrasonography is 4.36 cm in men and 4.14 cm in women. The GFR derived from median renal depth is more consistent with GFR derived from ultrasonography-measured renal depth than GFR derived from mean renal depth. Differences of GFR derived from median and ultrasonography-measured renal depth are not significantly different in the groups classified with creatinine value, age, sex, height, weight and body surface. When median value is adapted as a representative renal depth, we could obtain reliable GFR in transplanted kidney simply

The inherent politics of quality in public park management

DEFF Research Database (Denmark)

Lindholst, Andrej Christian; Konijnendijk, Cecil Cornelis; Fors, Hanna

2012-01-01

In this paper, we highlight and illustrate the inherent politics embedded in “quality” as a concept for managing public parks. Reflecting more generic quality concepts, contemporary quality models in park management include concepts for both operational, strategic and stakeholder management as well...... managing the park organisation itself. However, quality concepts and their application through various management models include as well as exclude the access, values and worldviews of particular interests. In this way, any particular quality concept and model embeds its own politics by inherent...... allocations of ‘who gets what, when and how’. We illustrate the inherent politics by providing a case study of a widely adopted quality model for operational management that has been adopted and implemented in Denmark as part of new public management reforms. In perspective, other quality concepts and models...

Static and dynamic filtrations of different clay, electrolytes, polymer systems; Filtrations statiques et dynamiques de differents systemes argile, electrolytes, polymere

Energy Technology Data Exchange (ETDEWEB)

Li, Y

1996-04-16

Filtration properties of model drilling fluids composed of water, clays, electrolytes and water soluble polymers have been studied in static and dynamic conditions on paper filters and rock slices. Filtration experiments combined with cake observations by cryo-S.E.M. and T.E.M., show the influence of the size shape of clay particles as well as their associating mode in suspension, on the texture of the cake, its permeability, and relaxation properties. These parameters depend on the nature of the electrolyte. The polymer reduces the cake permeability by enhancing the dispersion of the clay within the suspension, but mainly by plugging the porous network due its auto aggregation properties. The cake construction in dynamic conditions, is related to the state of aggregation of the initial suspension, its poly-dispersity, its sensitivity to shear rates, and also, to the permeability of the cake built at the beginning of the filtration. In all cases, the rate of thickening of the cake is slower and larger filtrate volumes are obtained compared to the static conditions. Shear rate has two effects: first, to dissociate the weak aggregates in suspension, second, to impose a size selection of the particles in the case of a poly-dispersed suspension. At high shear rates, a cake of constant thin thickness is quickly obtained. The thickness of this limiting cake depends on the fraction of small particles present in suspension, or that can be formed by dissociation of weak aggregates under shear rate. The permeability of this limiting cake formed in dynamic conditions is, as in static conditions, controlled by the size and the shape of the particles that form the cake or by the presence of a build loss reducer water soluble polymer. Filtrations carried out on Fontainebleau sandstones allow to visualize the internal cake and to precise the risks of formation damage by the drilling fluid. (author) 127 refs.

Uptake of wheel-filtration among clients of a supervised injecting facility: Can structured education work?

Science.gov (United States)

Steele, Maureen; Silins, Edmund; Flaherty, Ian; Hiley, Sarah; van Breda, Nick; Jauncey, Marianne

2018-01-01

Wheel-filtration of pharmaceutical opioid tablets is a recognised harm reduction strategy, but uptake of the practice among people who inject drugs is low. The study aimed to: (i) examine perceptions of filtration practices; (ii) provide structured education on wheel-filtration; and (iii) assess uptake of the practice. Frequent opioid tablet injectors (n = 30) attending a supervised injecting facility in Sydney, Australia, received hands-on instruction on wheel-filtration based on recommended practice. Pre-education, post-education and follow-up questionnaires were administered. Wheel-filtration was generally regarded as better than cotton-filtration (the typical method) in terms of perceived effects on health, ease of use and overall drug effect. Sixty-eight percent of those who said they would try wheel-filtration after the education had actually done so. Of those who usually used cotton-filtration, over half (60%) had used wheel-filtration two weeks later. Uptake of safer preparation methods for pharmaceutical opioid tablets increases after structured education in wheel-filtration. Findings suggest that SIFs are an effective site for this kind of education. Supervised injecting facility workers are uniquely positioned to provide harm reduction education at the time of injection. [Steele M, Silins E, Flaherty I, Hiley S, van Breda N, Jauncey M. Uptake of wheel-filtration among clients of a supervised injecting facility: Can structured education work? Drug Alcohol Rev 2018;37:116-120]. © 2017 Australasian Professional Society on Alcohol and other Drugs.

Indoor particles affect vascular function in the aged - An air filtration-based intervention study

DEFF Research Database (Denmark)

Brauner, E.V.; Forchhammer, L.; Moller, P.

2008-01-01

factors, P-selectin, plasma amyloid A, C-reactive protein, fibrinogen, IL-6, tumor necrosis factor-alpha, protein oxidation measured as 2-aminoadipic semialdehyde in plasma, urinary 8-iso-prostaglandin F-2 alpha, and blood pressure. Indoor air filtration significantly improved MVF by 8.1% (95% confidence...

Facility of aerosol filtration

Energy Technology Data Exchange (ETDEWEB)

Duverger de Cuy, G; Regnier, J

1975-04-18

Said invention relates to a facility of aerosol filtration, particularly of sodium aerosols. Said facility is of special interest for fast reactors where sodium fires involve the possibility of high concentrations of sodium aerosols which soon clog up conventional filters. The facility intended for continuous operation, includes at the pre-filtering stage, means for increasing the size of the aerosol particles and separating clustered particles (cyclone separator).

Inherent uncertainties in meteorological parameters for wind turbine design

Science.gov (United States)

Doran, J. C.

1982-01-01

Major difficulties associated with meteorological measurments such as the inability to duplicate the experimental conditions from one day to the next are discussed. This lack of consistency is compounded by the stochastic nature of many of the meteorological variables of interest. Moreover, simple relationships derived in one location may be significantly altered by topographical or synoptic differences encountered at another. The effect of such factors is a degree of inherent uncertainty if an attempt is made to describe the atmosphere in terms of universal laws. Some of these uncertainties and their causes are examined, examples are presented and some implications for wind turbine design are suggested.

Multi-objective optimization of a cascade refrigeration system: Exergetic, economic, environmental, and inherent safety analysis

International Nuclear Information System (INIS)

Eini, Saeed; Shahhosseini, Hamidreza; Delgarm, Navid; Lee, Moonyong; Bahadori, Alireza

2016-01-01

Highlights: • A multi-objective optimization is performed for a cascade refrigeration cycle. • The optimization problem considers inherently safe design as well as 3E analysis. • As a measure of inherent safety level a quantitative risk analysis is utilized. • A CO 2 /NH 3 cascade refrigeration system is compared with a CO 2 /C 3 H 8 system. - Abstract: Inherently safer design is the new approach to maximize the overall safety of a process plant. This approach suggests some risk reduction strategies to be implemented in the early stages of design. In this paper a multi-objective optimization was performed considering economic, exergetic, and environmental aspects besides evaluation of the inherent safety level of a cascade refrigeration system. The capital costs, the processing costs, and the social cost due to CO 2 emission were considered to be included in the economic objective function. Exergetic efficiency of the plant was considered as the second objective function. As a measure of inherent safety level, Quantitative Risk Assessment (QRA) was performed to calculate total risk level of the cascade as the third objective function. Two cases (ammonia and propane) were considered to be compared as the refrigerant of the high temperature circuit. The achieved optimum solutions from the multi–objective optimization process were given as Pareto frontier. The ultimate optimal solution from available solutions on the Pareto optimal curve was selected using Decision-Makings approaches. NSGA-II algorithm was used to obtain Pareto optimal frontiers. Also, three decision-making approaches (TOPSIS, LINMAP, and Shannon’s entropy methods) were utilized to select the final optimum point. Considering continuous material release from the major equipment in the plant, flash and jet fire scenarios were considered for the CO 2 /C 3 H 8 cycle and toxic hazards were considered for the CO 2 /NH 3 cycle. The results showed no significant differences between CO 2 /NH 3 and

Filtration aids in uranium ore processing

International Nuclear Information System (INIS)

Ford, H.L.; Levine, N.M.; Risdon, A.L.

1975-01-01

The patent describes a process whereby improved flocculation efficiency and filtration of carbonate leached uranium ore pulps are obtained by treating the filter feed slurry with an aqueous solution of hydroxyalkyl guar. (J.R.)

Industrial investigations of the liquid steel filtration

Directory of Open Access Journals (Sweden)

K. Janiszewski

2014-07-01

Full Text Available Hitherto existing investigations concerning the ceramic filter use in the steel making processes have given good results. The obtained results of filtration have proved that this method may be used as an effective and cheap way of steel filtration from non-metallic inclusions. Placing filters in the tundish is the best location considering the limitation of the possibility of secondary pollution of steel. Yet, the results presented in this paper, of an experiment prepared and carried out in the industrial environment, are the only positive results obtained, which are connected with so much quantities of liquid steel processed with use of the multi-hole ceramic filters.

Facilitating community water supply treatment : from transferring filtration technology to multi-stakeholder learning

NARCIS (Netherlands)

Visscher, J.T.

2006-01-01

For more than a quarter of a century, IRC has been supporting the development of Slow Sand Filtration (SSF) and more recently, together with CINARA, the pioneering of Multi-Stage Filtration (MSF) - a combination of Gravel Filtration and SSF that has been shown to have great potential as an effective

Hanford phosphate precipitation filtration process evaluation

International Nuclear Information System (INIS)

Walker, B.W.; McCabe, D.J.

1997-01-01

The purpose of this filter study was to evaluate cross-flow filtration as effective solid-liquid separation technology for treating Hanford wastes, outline operating conditions for equipment, examine the expected filter flow rates, and determine proper cleaning. A proposed Hanford waste pre-treatment process uses sodium hydroxide at high temperature to remove aluminum from sludge. This process also dissolves phosphates. Upon cooling to 40 degrees centigrade the phosphates form a Na7(PO4)2F9H2O precipitate which must be removed prior to further treatment. Filter studies were conducted with a phosphate slurry simulant to evaluate whether 0.5 micron cross-flow sintered metal Mott filters can separate the phosphate precipitate from the wash solutions. The simulant was recirculated through the filters at room temperature and filtration performance data was collected

Comparative study between in Vivo and Vitro radionuclide technique in measurement of Glomerular filtration rate

Energy Technology Data Exchange (ETDEWEB)

Ziada, G; Moustafa, H; Elhaddad, SH; Taalab, KH [Nuclear medicine department, Faculty of medicine, Cairo university, Cairo, (Egypt)

1995-10-01

Fifty patients were referred to nuclear medicine department in NEMROCK center for measurement of glomerular filtration rate (GFR). The group included 34 males and 16 females with a mean age of 38.3 {+-} 10.7 years. Estimation of GFR was done using 111-185 mBq of {sup 99m} Tc-DTPA with data collected on 128 x 128 matrix on IDAC computer every 15 seconds with calculation of renal uptake and GFR applying Gates method. 72 hours, a dose 3.7 mBq of {sup 51} Cr-EDTA with 2 blood samples taken at 120, 240 minutes with estimation of plasma clearance using Russel et al., method (1985). The mean clearance of {sup 51} Cr-EDTA was 79.61{+-}22.4 ml/min compared to 84.34{+-}26.3 ml/min. Using direct scintigraphic method with positive correlation using regression analysis (r=0.96). Also, both {sup 51} Cr-EDTA and in vivo {sup 99m} Tc-DTPA were positively correlated with creatinine clearance (r=0.87 and 0.91 respectively). A modified regression formulas was used for correction of the results of {sup 99m} Tc-DTPA values GFR ({sup 99m}Tc-DTPA) x 0.81 + 11 {+-} 6.4 ml/min. 4 figs., 1 tab.

Comparative study between in Vivo and Vitro radionuclide technique in measurement of Glomerular filtration rate

International Nuclear Information System (INIS)

Ziada, G.; Moustafa, H.; Elhaddad, SH.; Taalab, KH.

1995-01-01

Fifty patients were referred to nuclear medicine department in NEMROCK center for measurement of glomerular filtration rate (GFR). The group included 34 males and 16 females with a mean age of 38.3 ± 10.7 years. Estimation of GFR was done using 111-185 mBq of 99m Tc-DTPA with data collected on 128 x 128 matrix on IDAC computer every 15 seconds with calculation of renal uptake and GFR applying Gates method. 72 hours, a dose 3.7 mBq of 51 Cr-EDTA with 2 blood samples taken at 120, 240 minutes with estimation of plasma clearance using Russel et al., method (1985). The mean clearance of 51 Cr-EDTA was 79.61±22.4 ml/min compared to 84.34±26.3 ml/min. Using direct scintigraphic method with positive correlation using regression analysis (r=0.96). Also, both 51 Cr-EDTA and in vivo 99m Tc-DTPA were positively correlated with creatinine clearance (r=0.87 and 0.91 respectively). A modified regression formulas was used for correction of the results of 99m Tc-DTPA values GFR ( 99m Tc-DTPA) x 0.81 + 11 ± 6.4 ml/min. 4 figs., 1 tab

Short-term inhibition of prostaglandin synthesis has no effect on the elevated glomerular filtration rate of early insulin-dependent diabetes

DEFF Research Database (Denmark)

Christiansen, J S; Feldt-Rasmussen, B; Parving, H H

1985-01-01

Glomerular filtration rate and renal plasma flow (constant infusion technique using 125I-iothalamate and 131I-hippuran) were measured twice within a 1-week interval in nine young males with insulin-dependent diabetes of short duration (2-5 years). The study was performed in a randomized double...... +/- 43 versus 560 +/- 52 ml/min X 1.73 m2), when measured during placebo or indomethacin treatment, respectively. It is concluded that the steady-state enhancement of glomerular filtration rate and renal plasma flow found in early insulin-dependent diabetes is not due to an excessive activity...

Correlations of filtration flux enhanced by electric fields in crossflow microfiltration

Energy Technology Data Exchange (ETDEWEB)

Okada, K.; Nagase, Y. [Kurashiki University of Science and the Arts, Okayama (Japan). Department of Chemical Technology; Ohnishi, Y.; Nishihan, A.; Akagi, Y. [Okayama University of Science, Okayama (Japan). Department of Applied Chemistry

1997-12-01

The steady state filtration flux in electrically-enhanced crossflow microfiltration is estimated using a correlation equation proposed for several kinds of suspensions. Baker`s yeast and Rhodotorula glutinis were used as model samples of microbial cells, and PMMA particles were used as samples of non-living solids. Application of the electric field in crossflow microfiltration is a useful method for improving the filtration flux of these samples. High flux levels for the cells were achieved when an electric field above 3000 V/m was applied. The effect of the electric field in increasing the filtration flux of the steady state was analyzed theoretically using a force balance model where the viscous drag force, F{sub J}, the electrophoretic force, F{sub E}, and the re-entraining force, F{sub B}, were considered to act on a particle on the membrane surface under a steady state of filtration, respectively. From force balance analysis, it is found that on application of an electric field, the electro-osmotic effect can be neglected in the present study, so that the filtration flux of the steady state, J{sub ES}, can be presented by, J{sub ES}=U{sub EP}E+J{sub OS} where U{sub EP} is the electrophoretic mobility of particles and E is the electric field applied. J{sub OS} is the filtration flux in the absence of an electric field, which is correlated with the operating parameters for suspensions tested. 22 refs., 7 figs., 1 tab.

Safety assessment in plant layout design using indexing approach: Implementing inherent safety perspective

International Nuclear Information System (INIS)

Tugnoli, Alessandro; Khan, Faisal; Amyotte, Paul; Cozzani, Valerio

2008-01-01

The design of layout plans requires adequate assessment tools for the quantification of safety performance. The general focus of the present work is to introduce an inherent safety perspective at different points of the layout design process. In particular, index approaches for safety assessment and decision-making in the early stages of layout design are developed and discussed in this two-part contribution. Part 1 (accompanying paper) of the current work presents an integrated index approach for safety assessment of early plant layout. In the present paper (Part 2), an index for evaluation of the hazard related to the potential of domino effects is developed. The index considers the actual consequences of possible escalation scenarios and scores or ranks the subsequent accident propagation potential. The effects of inherent and passive protection measures are also assessed. The result is a rapid quantification of domino hazard potential that can provide substantial support for choices in the early stages of layout design. Additionally, a case study concerning selection among various layout options is presented and analyzed. The case study demonstrates the use and applicability of the indices developed in both parts of the current work and highlights the value of introducing inherent safety features early in layout design

76 FR 82323 - Design, Inspection, and Testing Criteria for Air Filtration and Adsorption Units

Science.gov (United States)

2011-12-30

... Filtration and Adsorption Units AGENCY: Nuclear Regulatory Commission. ACTION: Draft regulatory guide... for Air Filtration and Adsorption Units of Postaccident Engineered-Safety-Feature Atmosphere Cleanup... testing of air filtration and iodine adsorption units of engineered-safety-feature (ESF) atmosphere...

Changes in concentrations of triazine and acetamide herbicides by bank filtration, ozonation, and chlorination in a public water supply

Science.gov (United States)

Verstraeten, Ingrid M.; Thurman, E.M.; Lindsey, M.E.; Lee, E.C.; Smith, R.D.

2002-01-01

The changes in triazine and acetamide concentrations in water during natural and artificial treatment by bank filtration, ozonation, filtration, and chlorination were measured at the well field and drinking water treatment plant of Lincoln, Nebraska, USA. The city's groundwater supply is affected by induced infiltration and transport of triazines and acetamide herbicides from the Platte River in late spring and early summer. The objective of the study was to evaluate the effect of infiltration and treatment on the presence of triazines and acetamides in drinking water. Samples of river water, well water, and public supply water at various stages of water treatment were collected from 1997-1999 during spring-runoff when the presence of herbicides in the Platte River is largest. In 1999, parent compounds were reduced by 76% of the concentration present in river water (33% by bank filtration, 41% by ozonation, and 1.5% by chlorination). Metabolites of herbicides for which analytical techniques existed were reduced by 21% (plus 26% by bank filtration, minus 23% by ozonation, and minus 24% by chlorination). However, increases in concentrations of specific metabolite compounds were identified after bank filtration and ozonation. After bank filtration, increases in cyanazine amide, cyanazine acid, and deethylcyanazine acid were identified. After ozonation, concentrations of deisopropylatrazine, deethylatrazine, didealkylatrazine, atrazine amide-I, hydroxydeethylatrazine, hydroxydeisopopylatrazine, deethylcyanazine acid, and deethylcyanazine increased. Concentrations of cyanazine acid and ethanesulfonic and oxanilic acids of acetamides decreased during ozonation. Our findings suggest that bank filtration and ozonation of water in part can shift the assessment of risk to human health associated with the consumption of the water from the parent compounds to their degradation products.

Successful treatment of homozygous familial hypercholesterolemia using cascade filtration plasmapheresis.

Science.gov (United States)

Kardaş, Fatih; Cetin, Aysun; Solmaz, Musa; Büyükoğlan, Rüksan; Kaynar, Leylagül; Kendirci, Mustafa; Eser, Bülent; Unal, Ali

2012-12-01

The aim of this study was to report the efficacy of low-density lipoprotein cholesterol (LDL-C) apheresisusing a cascade filtration system in pediatric patients with homozygous familial hypercholesterolemia (FH), and toclarify the associated adverse effects and difficulties. LDL-C apheresis using a cascade filtration system was performed in 3 pediatric patientswith homozygous FH; in total, 120 apheresis sessions were performed. Cascade filtration therapy significantly reduced the mean LDL-C values from 418 ± 62 mg/dL to 145 ± 43 mg/dL (p= 0.011). We observed an acute mean reduction in the plasma level of total cholesterol (57.9%), LDL-C (70.8%),and high-density lipoprotein cholesterol (HDL-C) (40.7%). Treatments were well tolerated. The most frequent clinicaladverse effects were hypotension in 3 sessions (2.5%), chills (1.7%) in 2 sessions, and nausea/vomiting in 3 sessions(2.5%). Our experience using the cascade filtration system with 3 patients included good clinical outcomes andlaboratory findings, safe usage, and minor adverse effects and technical problems. None declared.

Noncausal two-stage image filtration at presence of observations with anomalous errors

OpenAIRE

S. V. Vishnevyy; S. Ya. Zhuk; A. N. Pavliuchenkova

2013-01-01

Introduction. It is necessary to develop adaptive algorithms, which allow to detect such regions and to apply filter with respective parameters for suppression of anomalous noises for the purposes of image filtration, which consist of regions with anomalous errors. Development of adaptive algorithm for non-causal two-stage images filtration at pres-ence of observations with anomalous errors. The adaptive algorithm for noncausal two-stage filtration is developed. On the first stage the adaptiv...

Development of High-Antifouling PPSU Ultrafiltration Membrane by Using Compound Additives: Preparation, Morphologies, and Filtration Resistant Properties.

Science.gov (United States)

Liu, Jie; Zhong, Zhencheng; Ma, Rui; Zhang, Weichen; Li, Jiding

2016-06-21

In this study, flat sheet asymmetric polyphenylsulfone (PPSU) ultrafiltration membranes with enhanced antifouling properties were prepared with a non-solvent induced phase separation (NIPS) method through compound additives containing a polymeric pore-forming agent, a small molecular non-solvent and a surfactant. The formation processes of the porous asymmetric membranes with different kinds of additives were studied in detail, and the microstructure controllable preparation of membrane was achieved by establishing a bridge between the membrane preparation parameters and separation performances. All prepared membranes were characterized by using a scanning electron microscope (SEM), contact angle analysis, porosity, maximum pore size, water and BSA solution permeability studies. The performance efficiency of the membrane was evaluated by using BSA as a model foulant in terms of permeability, solute rejection (R), Rm (membrane inherent resistance), Rc (cake layer resistance), and Rp (pore plugging resistance). The results showed that when the compound additives were used, the inter-connected pores were observed, maximum pore size, contact angle and membrane filtration resistance decreased, while the porosity increased. When PVP compound additives were added, the water flux increased from 80.4 to 148.1 L/(m²·h), the BSA rejection increased from 53.2% to 81.5%. A similar trend was observed for membranes with added PEG compound additives; the water flux and BSA rejection simultaneously increased. The filtration resistance decreased as a result of compound additives. The uniformity of membrane and the number of effective pores could be enhanced by adding compound additives through the cooperation of different additives.

Development of High-Antifouling PPSU Ultrafiltration Membrane by Using Compound Additives: Preparation, Morphologies, and Filtration Resistant Properties

Directory of Open Access Journals (Sweden)

Jie Liu

2016-06-01

Full Text Available In this study, flat sheet asymmetric polyphenylsulfone (PPSU ultrafiltration membranes with enhanced antifouling properties were prepared with a non-solvent induced phase separation (NIPS method through compound additives containing a polymeric pore-forming agent, a small molecular non-solvent and a surfactant. The formation processes of the porous asymmetric membranes with different kinds of additives were studied in detail, and the microstructure controllable preparation of membrane was achieved by establishing a bridge between the membrane preparation parameters and separation performances. All prepared membranes were characterized by using a scanning electron microscope (SEM, contact angle analysis, porosity, maximum pore size, water and BSA solution permeability studies. The performance efficiency of the membrane was evaluated by using BSA as a model foulant in terms of permeability, solute rejection (R, Rm (membrane inherent resistance, Rc (cake layer resistance, and Rp (pore plugging resistance. The results showed that when the compound additives were used, the inter-connected pores were observed, maximum pore size, contact angle and membrane filtration resistance decreased, while the porosity increased. When PVP compound additives were added, the water flux increased from 80.4 to 148.1 L/(m2·h, the BSA rejection increased from 53.2% to 81.5%. A similar trend was observed for membranes with added PEG compound additives; the water flux and BSA rejection simultaneously increased. The filtration resistance decreased as a result of compound additives. The uniformity of membrane and the number of effective pores could be enhanced by adding compound additives through the cooperation of different additives.

Simulations of Microbial-Enhanced Oil Recovery: Adsorption and Filtration

DEFF Research Database (Denmark)

Nielsen, Sidsel Marie; Nesterov, Igor; Shapiro, Alexander

2014-01-01

In the context of microbial-enhanced oil recovery (MEOR) with injection of surfactant-producing bacteria into the reservoir, different types of bacteria attachment and growth scenarios are studied using a 1D simulator. The irreversible bacteria attachment due to filtration similar to the deep bed...... applied to filtration model provides formation of two oil banks during recovery. This feature is not reproduced by application of REA model or DBF with growth in attached phase. This makes it possible to select a right model based on the qualitative analysis of the experimental data. A criterion...... is introduced to study the process efficiency: the dimensionless time at which average recovery between pure water injection and maximum surfactant effect is reached. This characteristic recovery period (CRP) was studied as a function of the different MEOR parameters such as bacterial activity, filtration...

A Brief Review of Filtration Studies for Waste Treatment at the Hanford Site

Energy Technology Data Exchange (ETDEWEB)

Daniel, Richard C.; Schonewill, Philip P.; Shimskey, Rick W.; Peterson, Reid A.

2010-12-01

This document completes the requirements of Milestone 1-2, PNNL Draft Literature Review, discussed in the scope of work outlined in the EM-31 Support Project task plan WP-2.3.6-2010-1. The focus of task WP 2.3.6 is to improve the U.S. Department of Energy’s (DOE’s) understanding of filtration operations for high-level waste (HLW) to enhance filtration and cleaning efficiencies, thereby increasing process throughput and reducing the sodium demand (through acid neutralization). Developing the processes for fulfilling the cleaning/backpulsing requirements will result in more efficient operations for both the Hanford Tank Waste Treatment and Immobilization Plant (WTP) and the Savannah River Site (SRS), thereby increasing throughput by limiting cleaning cycles. The purpose of this document is to summarize Pacific Northwest National Laboratory’s (PNNL’s) literature review of historical filtration testing at the laboratory and of testing found in peer-reviewed journals. Eventually, the contents of this document will be merged with a literature review by SRS to produce a summary report for DOE of the results of previous filtration testing at the laboratories and the types of testing that still need to be completed to address the questions about improved filtration performance at WTP and SRS. To this end, this report presents 1) a review of the current state of crossflow filtration knowledge available in the peer-reviewed literature, 2) a detailed review of PNNL-related filtration studies specific to the Hanford site, and 3) an overview of current waste filtration models developed by PNNL and suggested avenues for future model development.

Impact of two particle measurement techniques on the determination of N95 class respirator filtration performance against ultrafine particles

International Nuclear Information System (INIS)

Mostofi, Reza; Noël, Alexandra; Haghighat, Fariborz; Bahloul, Ali; Lara, Jaime; Cloutier, Yves

2012-01-01

Highlights: ► Performance evaluation of respirator using two different measurement techniques. ► Impaction and electrical mobility were used to characterize ultrafine particle. ► The experiment was done using ultrafine-sized poly-dispersed aerosols. ► Both techniques show that MPPS would occur at a similar size range. - Abstract: The purpose of this experimental study was to compare two different particle measurement devices; an Electrical Low Pressure Impactor (ELPI) and a Scanning Mobility Particle Sizer (SMPS), to measure the number concentration and the size distribution of NaCl salt aerosols to determine the collection efficiency of filtering respirators against poly disperse aerosols. Tests were performed on NIOSH approved N95 filtering face-piece respirators (FFR), sealed on a manikin head. Ultrafine particles found in the aerosols were also collected and observed by transmission electron microscopy (TEM). According to the results, there is a systematic difference for the particle size distribution measured by the SMPS and the ELPI. It is largely attributed to the difference in the measurement techniques. However, in spite of these discrepancies, reasonably similar trends were found for the number concentration with both measuring instruments. The particle penetration, calculated based on mobility and aerodynamic diameters, never exceeded 5% for any size range measured at constant flow rate of 85 L/min. Also, the most penetrating particle size (MPPS), with the lowest filtration efficiency, would occur at a similar ultrafine size range <100 nm. With the ELPI, the MPPS was at 70 nm aerodynamic diameter, whereas it occurred at 40 nm mobility diameter with the SMPS.

Portable Hybrid Powered Water Filtration Device

Directory of Open Access Journals (Sweden)

Maria Lourdes V. Balansay

2015-08-01

Full Text Available The existing water filtration device has features that can be developed to be more useful and functional during emergency situations. The project’s development has been aided by following provisions in PEC, NEC, NEMA and Philippine National Standard for Safe Drinking Water provide standards for the construction of the project. These standards protect both the prototype and the user. These also served as guide for the maintenance of every component. The design of the portable hybrid powered water filtration device shows that the project has more advanced features such as portability and the power supply used such as photovoltaic module solar cells and manually operated generator. This also shows its effectiveness and reliability based on the results of discharging test, water quality test and water production test. Based on analysis of the overall financial aspects, the machine can be profitable and the amount of revenue and operating cost will increase as years pass. Using the proper machine/ tools and methods of fabrication helps in easy assembly of the project. The materials and components used are cost effective and efficient. The best time for charging the battery using solar panel is 9:00 am onwards while the hand crank generator is too slow because the generated current is little. The water filtration device is very efficient regarding the operating hours and water production. The machine may have a great effect to society and economy in generation of clean available water at less cost.

Development of filtration equipment to reuse PFC decontamination wastewater

International Nuclear Information System (INIS)

Kim, Gye Nam; Lee, Sung Yeol; Won, Hui Jun; Jung Chong Hun; Oh, Won Zin; Park, Jin Ho

2005-01-01

When PFC(Perfluorocarbonate) decontamination technology is applied to removal of radioactive contaminated particulate adhered at surface during the operation of nuclear research facilities, it is necessary to develop a filtration equipment to reuse of PFC solution due to high price, also to minimize the volume of second wastewater. Contaminated characteristics of hot particulate was investigated and a filtration process was presented to remove suspended radioactive particulate from PFC decontamination wastewater generated on PFC decontamination

Renal blood flow using arterial spin labelling MRI and calculated filtration fraction in healthy adult kidney donors Pre-nephrectomy and post-nephrectomy.

Science.gov (United States)

Cutajar, Marica; Hilton, Rachel; Olsburgh, Jonathon; Marks, Stephen D; Thomas, David L; Banks, Tina; Clark, Christopher A; Gordon, Isky

2015-08-01

Renal plasma flow (RPF) (derived from renal blood flow, RBF) and glomerular filtration rate (GFR) allow the determination of the filtration fraction (FF), which may have a role as a non-invasive renal biomarker. This is a hypothesis-generating pilot study assessing the effect of nephrectomy on renal function in healthy kidney donors. Eight living kidney donors underwent arterial spin labelling (ASL) magnetic resonance imaging (MRI) and GFR measurement prior to and 1 year after nephrectomy. Chromium-51 labelled ethylenediamine tetraacetic acid ((51)Cr-EDTA) with multi-blood sampling was undertaken and GFR calculated. The RBF and GFR obtained were used to calculate FF. All donors showed an increase in single kidney GFR of 24 - 75 %, and all but two showed an increase in FF (-7 to +52 %) after nephrectomy. The increase in RBF, and hence RPF, post-nephrectomy was not as great as the increase in GFR in seven out of eight donors. As with any pilot study, the small number of donors and their relatively narrow age range are potential limiting factors. The ability to measure RBF, and hence RPF, non-invasively, coupled with GFR measurement, allows calculation of FF, a biomarker that might provide a sensitive indicator of loss of renal reserve in potential donors. • Non-invasive MRI measured renal blood flow and calculated renal plasma flow. • Effect of nephrectomy on blood flow and filtration in donors is presented. • Calculated filtration fraction may be a useful new kidney biomarker.

Primary effluent filtration for coastal discharges

Energy Technology Data Exchange (ETDEWEB)

Cooper-Smith, G.D. [Yorkshire Water Services, Huddersfield (United Kingdom); Rundle, H. [The Capital Controls Group, Nottingham (United Kingdom)

1998-12-31

The use of a Tetra Deep Bed filter demonstration unit to treat primary effluent (Primary Effluent Filtration, PEF) was investigated. PEF proved capable of achieving the UWWTD primary standard, even when the primary stage performs poorly, but is not a cost-effective alternative to chemically assisted settlement. Results demonstrated that using a 1.5 to 2.2 mm grade medium, a filtration rate of 5 m/h, three backwashes a day and dosing 40 mg/l of PAXXL60 (a polyaluminium silicte) an average effluent quality of 20 mg/l BOD and 15 mgl/l total solid could be achieved. UV disinfection produced an effluent which complied with the Bathing Water Directive imperative requirement. A high enterovirus kill was also achieved. However, considerable additional work would be required before PEF could be considered suitable for full-scale applications. (orig.)

High Temperature Particle Filtration Technology; TOPICAL

International Nuclear Information System (INIS)

Besmann, T.M.

2001-01-01

High temperature filtration can serve to improve the economic, environmental, and energy performance of chemical processes. This project was designed to evaluate the stability of filtration materials in the environments of the production of dimethyldichlorosilane (DDS). In cooperation with Dow Corning, chemical environments for the fluidized bed reactor where silicon is converted to DDS and the incinerator where vents are cornbusted were characterized. At Oak Ridge National Laboratory (ORNL) an exposure system was developed that could simulate these two environments. Filter samples obtained from third parties were exposed to the environments for periods up to 1000 hours. Mechanical properties before and after exposure were determined by burst-testing rings of filter material. The results indicated that several types of filter materials would likely perform well in the fluid bed environment, and two materials would be good candidates for the incinerator environment

Air filtration and indoor air quality

DEFF Research Database (Denmark)

Bekö, Gabriel

2006-01-01

Demands for better indoor air quality are increasing, since we spend most of our time indoors and we are more and more aware of indoor air pollution. Field studies in different parts of the world have documented that high percentage of occupants in many offices and buildings find the indoor air...... decent ventilation and air cleaning/air filtration, high indoor air quality cannot be accomplished. The need for effective air filtration has increased with increasing evidence on the hazardous effects of fine particles. Moreover, the air contains gaseous pollutants, removal of which requires various air...... cleaning techniques. Supply air filter is one of the key components in the ventilation system. Studies have shown that used ventilation filters themselves can be a significant source of indoor air pollution with consequent impact on perceived air quality, sick building syndrome symptoms and performance...

Osmosis, filtration and fracture of porous media

International Nuclear Information System (INIS)

Suarez Antola, R.

2001-01-01

Filtration was produced in a small scale physical model of a granular porous medium of cylindrical shape.The same volume flow was obtained either applying a difference in hydrostatic pressure or in osmotic pressure.In the first case a process of sustained erosion ending in an hydraulic short circuit was observed,while in the second case the material remained stable.This paradoxical strength behaviour is explained using some results from differential geometry,classical field theory and thermo-kinetic theory.The fracture process of a continuous matrix in a porous medium under the combined effect of filtration and external mechanical loads in then considered.The obtained results can be applied to the textural and compressive strength of wet concrete

The development of an inherent safety approach to the prevention of domino accidents.

Science.gov (United States)

Cozzani, Valerio; Tugnoli, Alessandro; Salzano, Ernesto

2009-11-01

The severity of industrial accidents in which a domino effect takes place is well known in the chemical and process industry. The application of an inherent safety approach for the prevention of escalation events leading to domino accidents was explored in the present study. Reference primary scenarios were analyzed and escalation vectors were defined. Inherent safety distances were defined and proposed as a metric to express the intensity of the escalation vectors. Simple rules of thumb were presented for a preliminary screening of these distances. Swift reference indices for layout screening with respect to escalation hazard were also defined. Two case studies derived from existing layouts of oil refineries were selected to understand the potentialities coming from the application in the methodology. The results evidenced that the approach allows a first comparative assessment of the actual domino hazard in a layout, and the identification of critical primary units with respect to escalation events. The methodology developed also represents a useful screening tool to identify were to dedicate major efforts in the design of add-on measures, optimizing conventional passive and active measures for the prevention of severe domino accidents.

Are vacuum-filtrated reduced graphene oxide membranes symmetric?

KAUST Repository

Tang, Bo; Zhang, Lianbin; Li, Renyuan; Wu, Jinbo; Hedhili, Mohamed Neijib; Wang, Peng

2015-01-01

Graphene or reduced graphene oxide (rGO) membrane-based materials are promising for many advanced applications due to their exceptional properties. One of the most widely used synthesis methods for rGO membranes is vacuum filtration of graphene oxide (GO) on a filter membrane, followed by reduction, which shows great advantages such as operational convenience and good controllability. Despite vacuum-filtrated rGO membranes being widely used in many applications, a fundamental question is overlooked: are the top and bottom surfaces of the membranes formed at the interfaces with air and with the filter membrane respectively symmetric or asymmetric? This work, for the first time, reports the asymmetry of the vacuum-filtrated rGO membranes and discloses the filter membranes’ physical imprint on the bottom surface of the rGO membrane, which takes place when the filter membrane surface pores have similar dimension to GO sheets. This result points out that the asymmetric surface properties should be cautiously taken into consideration while designing the surface-related applications for GO and rGO membranes.

Are vacuum-filtrated reduced graphene oxide membranes symmetric?

KAUST Repository

Tang, Bo

2015-12-02

Graphene or reduced graphene oxide (rGO) membrane-based materials are promising for many advanced applications due to their exceptional properties. One of the most widely used synthesis methods for rGO membranes is vacuum filtration of graphene oxide (GO) on a filter membrane, followed by reduction, which shows great advantages such as operational convenience and good controllability. Despite vacuum-filtrated rGO membranes being widely used in many applications, a fundamental question is overlooked: are the top and bottom surfaces of the membranes formed at the interfaces with air and with the filter membrane respectively symmetric or asymmetric? This work, for the first time, reports the asymmetry of the vacuum-filtrated rGO membranes and discloses the filter membranes’ physical imprint on the bottom surface of the rGO membrane, which takes place when the filter membrane surface pores have similar dimension to GO sheets. This result points out that the asymmetric surface properties should be cautiously taken into consideration while designing the surface-related applications for GO and rGO membranes.

Corrosion-product filtration in PWRs: Topical report

International Nuclear Information System (INIS)

Balakrishnan, P.V.; Buckley, L.P.

1988-04-01

As part of a programme on the optimization of pressurized water reactor (PWR) secondary side water treatment, laboratory-scale studies on filtration of the feedwater using materials having chemically active adsorbing surfaces were carried out. Graphite, zirconia and titania were identified, from a review of existing literature, as suitable filtration media, the last two because of their ion-exchange capability. The efficiency of filters packed with granular graphite for filtration of simulated feed train corrosion products and the pressure drop across the filters were determined as functions of filter dimensions and operating parameters at room temperature. A rough sizing of a full-flow feedwater filter using granular graphite was done on the basis of observations from the room temperature tests. Further studies are suggested at low concentrations of the corrosion product and at high temperature typical of steam generator feedwater after the high pressure heaters to derive realistic design parameters for a filter for installation in the PWR secondary circuit. Zirconia was produced in the form of spherical particles using a sol-gel process. The zirconia behaved as an anion exchanger at low pH and as a cation exchanger at high pH. Its suitability for purification of water at high temperature should be determined by futher studies. 30 refs., 16 figs., 8 tabs

Some observations on air filtration

NARCIS (Netherlands)

Kluyver, A.J.; Visser, J.

1950-01-01

1. A method has been developed for testing the filtration efficiency of some filter materials. For each of the materials investigated — cotton wool, stillite and carbon — a suitable filter has been devised. 2. The filtered air was analyzed as to its germ content with the aid of a set of 3 capillary

Water Filtration through Homogeneous Granulated Charge

Directory of Open Access Journals (Sweden)

A. M. Krautsou

2005-01-01

Full Text Available General relationship for calculation of water filtration through homogeneous granulated charge has been obtained. The obtained relationship has been compared with experimental data. Discrepancies between calculated and experimental values do not exceed 6 % throughout the entire investigated range.

Impacts of extreme flooding on riverbank filtration water quality.

Science.gov (United States)

Ascott, M J; Lapworth, D J; Gooddy, D C; Sage, R C; Karapanos, I

2016-06-01

Riverbank filtration schemes form a significant component of public water treatment processes on a global level. Understanding the resilience and water quality recovery of these systems following severe flooding is critical for effective water resources management under potential future climate change. This paper assesses the impact of floodplain inundation on the water quality of a shallow aquifer riverbank filtration system and how water quality recovers following an extreme (1 in 17 year, duration >70 days, 7 day inundation) flood event. During the inundation event, riverbank filtrate water quality is dominated by rapid direct recharge and floodwater infiltration (high fraction of surface water, dissolved organic carbon (DOC) >140% baseline values, >1 log increase in micro-organic contaminants, microbial detects and turbidity, low specific electrical conductivity (SEC) 400% baseline). A rapid recovery is observed in water quality with most floodwater impacts only observed for 2-3 weeks after the flooding event and a return to normal groundwater conditions within 6 weeks (lower fraction of surface water, higher SEC, lower DOC, organic and microbial detects, DO). Recovery rates are constrained by the hydrogeological site setting, the abstraction regime and the water quality trends at site boundary conditions. In this case, increased abstraction rates and a high transmissivity aquifer facilitate rapid water quality recoveries, with longer term trends controlled by background river and groundwater qualities. Temporary reductions in abstraction rates appear to slow water quality recoveries. Flexible operating regimes such as the one implemented at this study site are likely to be required if shallow aquifer riverbank filtration systems are to be resilient to future inundation events. Development of a conceptual understanding of hydrochemical boundaries and site hydrogeology through monitoring is required to assess the suitability of a prospective riverbank filtration

[Differences of inherent optical properties of inland lake water body in typical seasons].

Science.gov (United States)

Sun, De-Yong; Li, Yun-Mei; Wang, Qiao; Le, Cheng-Fen; Huang, Chang-Chun; Wang, Li-Zhen

2008-05-01

Inherent optical property is one of the important properties of water body, which lays the foundation for the establishment of water color analytical models. By using quantity filter technology (QFT) and BB9 backscattering meter, the absorption coefficients of chromophoric dissolved organic matter (CDOM) and total suspended matters (TSM) and the backscattering coefficient of TSM in the water body at Meiliang Bay of Taihu Lake were measured in summer and winter. Based on the spectral comparison of the absorption and backscattering coefficients, their differences between the two seasons were demonstrated, and the reasons that caused these differences were also explored in the context of their relations to the changes in water quality. Consequently, water environment condition could be revealed by using the inherent optical property. The relationship between the backscattering coefficient and the TSM concentration was established, which could provide supporting coefficients to the analytical models to be developed.

Effect of polymer type on characterization and filtration performances of multi-walled carbon nanotubes (MWCNT)-COOH-based polymeric mixed matrix membranes.

Science.gov (United States)

Sengur-Tasdemir, Reyhan; Mokkapati, Venkata R S S; Koseoglu-Imer, Derya Y; Koyuncu, Ismail

2018-05-01

Multi-walled carbon nanotubes (MWCNTs) can be used for the fabrication of mixed matrix polymeric membranes that can enhance filtration perfomances of the membranes by modifying membrane surface properties. In this study, detailed characterization and filtration performances of MWCNTs functionalized with COOH group, blended into polymeric flat-sheet membranes were investigated using different polymer types. Morphological characterization was carried out using atomic force microscopy, scanning electron microscopy and contact angle measurements. For filtration performance tests, protein, dextran, E. coli suspension, Xanthan Gum and real activated sludge solutions were used. Experimental data and analyses revealed that Polyethersulfone (PES) + MWCNT-COOH mixed matrix membranes have superior performance abilities compared to other tested membranes.

THE STUDY ON IN VITRO DIGESTIBILITY OF SOAKED PALM OIL FIBER BY FILTRATED PALM OIL FRUIT BUNCH ASH

Directory of Open Access Journals (Sweden)

Ari L. Darmawan

2014-06-01

Full Text Available Palm oil fiber has its potency as feed fiber source for ruminant, but contains high lignin and causes limited digestibility. This research was carried out to find the effect of soaking palm oil fiber in filtrated palm oil fruit bunch ash (FPOFBA on in vitro digestibility. This experiment used a completely randomized design that repeated for 4times. Palm oil fruit bunch ash was mixed in water and entered into container for 24 hours within concentrations, consists of: 50, 100, 150 and 200 g/L. Moreover, this filtrate used to soak palm oil fiber for 3 hours. The processed products were analyzed for their level of lignin and crude fiber. Meanwhile, in vitro test was used to measure digestibility. It showed that soaking in filtrated palm oil fruit bunch ash gave significant effect to decrease level of lignin and crude fiber (P0.05, such as 23.48 and 24.12% as well as 16.70 and 17.06 % in each. It can be concluded that soaked palm oil fiber with 150 g/L concentration of filtrated palm oil fruit bunch ash was more effective in improving digestibility.

Measurement of glomerular filtration rate using inulin prepared from Vernonia herbacea, a Brazilian native species.

Science.gov (United States)

Dias-Tagliacozzo, G M; Dietrich, S M; Mello-Aires, M

1996-10-01

Vernonia herbacea (Vell.) Rusby (Asteraceae) is a perennial herb native to the cerrado vegetation of tropical areas in Brazil, which accumulates inulin in the underground reserve organs. The aim of this paper was to determine whether the inulin extracted from V. herbacea could replace commercial inulin for the measurement of glomerular filtration rate (GFR). Underground organs of vegetative plants were collected from a preserved area of the Brazilian cerrado. The inulin fraction utilized was obtained by ethanol precipitation after discarding the high molecular mass fructans in the freeze-thawing precipitate. GFR was determined in male Wistar rats anesthetized with inactin (100 mg/kg), which received intravenously commercial inulin obtained from Dahlia sp (Sigma) or Vernonia herbacea inulin (30 mg/100 g) as a priming dose and 0.05 mg min-1 100 g-1 as a sustaining dose in isotonic saline at the rate of 0/055 ml/min. Clearance was determined during 3 periods, with urine collected from the bladder and blood from the carotid artery. There was no significant difference in the GFR measured by clearance in inulin from both sources even when the plasma concentration of inulin from V. herbacea was doubled. The mean arterial pressure did not vary after the application of both inulins, indicating that they do not produce systemic side effects. The filtered load and the excreted amount of inulin from V. herbacea were equal, showing that the substance is not influenced by tubular function. These results demonstrate that the inulin from V. herbacea can substitute for imported inulin for the determination of GFR and in experiments of kidney microperfusion as a marker of tubular water reabsorption.

Estimated glomerular filtration rate is an early biomarker of cardiac surgery-associated acute kidney injury.

Science.gov (United States)

Candela-Toha, Ángel; Pardo, María Carmen; Pérez, Teresa; Muriel, Alfonso; Zamora, Javier

2018-04-20

and objective Acute kidney injury (AKI) diagnosis is still based on serum creatinine and diuresis. However, increases in creatinine are typically delayed 48h or longer after injury. Our aim was to determine the utility of routine postoperative renal function blood tests, to predict AKI one or 2days in advance in a cohort of cardiac surgery patients. Using a prospective database, we selected a sample of patients who had undergone major cardiac surgery between January 2002 and December 2013. The ability of the parameters to predict AKI was based on Acute Kidney Injury Network serum creatinine criteria. A cohort of 3,962 cases was divided into 2groups of similar size, one being exploratory and the other a validation sample. The exploratory group was used to show primary objectives and the validation group to confirm results. The ability to predict AKI of several kidney function parameters measured in routine postoperative blood tests, was measured with time-dependent ROC curves. The primary endpoint was time from measurement to AKI diagnosis. AKI developed in 610 (30.8%) and 623 (31.4%) patients in the exploratory and validation samples, respectively. Estimated glomerular filtration rate using the MDRD-4 equation showed the best AKI prediction capacity, with values for the AUC ROC curves between 0.700 and 0.946. We obtained different cut-off values for estimated glomerular filtration rate depending on the degree of AKI severity and on the time elapsed between surgery and parameter measurement. Results were confirmed in the validation sample. Postoperative estimated glomerular filtration rate using the MDRD-4 equation showed good ability to predict AKI following cardiac surgery one or 2days in advance. Copyright © 2018 Sociedad Española de Nefrología. Published by Elsevier España, S.L.U. All rights reserved.

Filtration of Oil-furnace Carbon Black Dust Particles from the Tail Gases by Filter Bags With PTFE Membrane

Directory of Open Access Journals (Sweden)

Čuzela, D.

2010-01-01

Full Text Available During the industrial production of oil furnace carbon black, tail gases containing oil-furnace carbon black dust particles are emitted to the atmosphere. In the carbon black plant, Petrokemija d. d., there are six exhaust stacks for tail gases. Each of them has installed process equipment for cleaning tail gases. Efficiency of cleaning mainly depends on equipment construction and cleaning technology. The vicinity of the town, quality of the air in the region of Kutina, regarding floating particles PM10, and corporate responsibility for further enviromental improvement, imposes development of new methods that will decrease the emmision of oil-furnace carbon black dust particles in the air. Combining centrifugal percipitator and filter, special construction of cyclofilter for filtration of oil-furnace carbon black dust particles from tail gases by using PTFE (polytetrafluoroethylene membrane filter bags, was designed. Developed filtration technique provides η = 99.9 % efficiency of filtration. Construction part of the filter contains the newest generation of PTFE membrane filter bags with the ability of jet pulse cleaning. Using the PTFE membrane filter bags technology, filtration efficiency for oil-furnace carbon black dust particles in tail gases of maximum γ=5mgm-3can be achieved. The filtration efficiency was monitored continuously measuring the concentration of the oil-furnace carbon black dust particles in the tail gases with the help of in situ electronic probe. The accomplished filtration technology is the base for the installation of the PTFE membrane filter bags in the main operation filters which will provide better protection of the air in the town of Kutina against floating particles PM10.

Creatinine Clearance Is Not Equal to Glomerular Filtration Rate and Cockcroft-Gault Equation Is Not Equal to CKD-EPI Collaboration Equation.

Science.gov (United States)

Fernandez-Prado, Raul; Castillo-Rodriguez, Esmeralda; Velez-Arribas, Fernando Javier; Gracia-Iguacel, Carolina; Ortiz, Alberto

2016-12-01

Direct oral anticoagulants (DOACs) may require dose reduction or avoidance when glomerular filtration rate is low. However, glomerular filtration rate is not usually measured in routine clinical practice. Rather, equations that incorporate different variables use serum creatinine to estimate either creatinine clearance in mL/min or glomerular filtration rate in mL/min/1.73 m 2 . The Cockcroft-Gault equation estimates creatinine clearance and incorporates weight into the equation. By contrast, the Modification of Diet in Renal Disease and Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equations estimate glomerular filtration rate and incorporate ethnicity but not weight. As a result, an individual patient may have very different renal function estimates, depending on the equation used. We now highlight these differences and discuss the impact on routine clinical care for anticoagulation to prevent embolization in atrial fibrillation. Pivotal DOAC clinical trials used creatinine clearance as a criterion for patient enrollment, and dose adjustment and Federal Drug Administration recommendations are based on creatinine clearance. However, clinical biochemistry laboratories provide CKD-EPI glomerular filtration rate estimations, resulting in discrepancies between clinical trial and routine use of the drugs. Copyright © 2016 Elsevier Inc. All rights reserved.

Filtration and Leach Testing for PUREX Cladding Sludge and REDOX Cladding Sludge Actual Waste Sample Composites

Energy Technology Data Exchange (ETDEWEB)

Shimskey, Rick W.; Billing, Justin M.; Buck, Edgar C.; Casella, Amanda J.; Crum, Jarrod V.; Daniel, Richard C.; Draper, Kathryn E.; Edwards, Matthew K.; Hallen, Richard T.; Kozelisky, Anne E.; MacFarlan, Paul J.; Peterson, Reid A.; Swoboda, Robert G.

2009-03-02

of gibbsite, and its impact on filtration. The initial sample was diluted with a liquid simulant to simulate the receiving concentration of retrieved tank waste into the UFP2 vessel (< 10 wt% undissolved solids). Filtration testing was performed on the dilute waste sample and dewatered to a higher solids concentration. Filtration testing was then performed on the concentrated slurry. Afterwards, the slurry was caustic leached to remove aluminum present in the undissolved solid present in the waste. The leach was planned to simulate leaching conditions in the UFP2 vessel. During the leach, slurry supernate samples were collected to measure the dissolution rate of aluminum in the waste. After the slurry cooled down from the elevated leach temperature, the leach liquor was dewatered from the solids. The remaining slurry was rinsed and dewatered with caustic solutions to remove a majority of the dissolved aluminum from the leached slurry. The concentration of sodium hydroxide in the rinse solutions was high enough to maintain the solubility of the aluminum in the dewatered rinse solutions after dilution of the slurry supernate. Filtration tests were performed on the final slurry to compare to filtration performance before and after caustic leaching.

The impact of metallic filter media on HEPA filtration

International Nuclear Information System (INIS)

Chadwick, Chris; Kaufman, Seth

2006-01-01

Traditional HEPA filter systems have limitations that often prevent them from solving many of the filtration problems in the nuclear industry; particularly in applications where long service or storage life, high levels of radioactivity, dangerous decomposition products, chemical aggression, organic solvents, elevated operating temperatures, fire resistance and resistance to moisture are issues. This paper addresses several of these matters of concern by considering the use of metallic filter media to solve HEPA filtration problems ranging from the long term storage of transuranic waste at the WIPP site, spent and damaged fuel assemblies, in glove box ventilation and tank venting to the venting of fumes at elevated temperatures from incinerators, vitrification processes and conversion and sintering furnaces as well as downstream of iodine absorbers in gas cooled reactors in the UK. The paper reviews the basic technology, development, performance characteristics and filtration efficiency, flow versus differential pressure, cleanability and costs of sintered metal fiber in comparison with traditional resin bonded glass fiber filter media and sintered metal powder filter media. Examples of typical filter element and system configurations and applications will be presented The paper will also address the economic case for installing self cleaning pre-filtration, using metallic media, to recover the small volumes of dust that would otherwise blind large volumes of final disposable HEPA filters, thus presenting a route to reduce ultimate disposal volumes and secondary waste streams. (authors)

Tools for Schools: Filtration for Improved Air Quality. Technical Services Bulletin.

Science.gov (United States)

2001

This product bulletin addresses air pollution control in educational facilities to enhance educational performance, provides air quality recommendations for schools, and examines the filtration needs of various school areas. The types of air particles typically present are highlighted, and the use of proper filtration to control gases and vapors…

Successful Treatment Of Homozygous Familial Hypercholesterolemia Using Cascade Filtration Plasmapheresis

Directory of Open Access Journals (Sweden)

Fatih Kardas

2012-12-01

Full Text Available OBJECTIVE: The aim of our study is to discuss the efficacy of low-density lipoprotein-cholesterol (LDL-C apheresis procedure using the cascade filtration system for pediatric patients with homozygous familial hypercholesterolemia (FH, and to clarify the adverse effects and difficulties. METHODS: LDL apheresis using the cascade filtration system was performed in 3 pediatric patients with homozygous FH. In total, 120 apheresis sessions were performed for all patients. RESULTS: Cascade filtration therapy significantly reduced the mean LDL-C values from 418 ± 62 mg/dl to 145 ± 43 mg/dl (p<0.05. We determined an acute mean reduction in the plasma levels of total cholesterol (57.9%, LDL cholesterol (70.8%, and high-density lipoprotein (HDL cholesterol (40.7%. Treatments were well tolerated. The most frequent clinical adverse effects were hypotension in 3 sessions (2.5%, chills/feeling cold (1.7% in 2 sessions, and nausea and vomiting in 3 sessions (2.5%. CONCLUSION: Our experience with three patients using the cascade filtration system were, good clinical outcomes, laboratory findings, safety of usage, minor adverse effects and technical problems.

Four years experience with filtration systems in commercial nurseries for eliminating Phytophthora species from recirculation water

Science.gov (United States)

T. Ufer; M. Posner; H.-P. Wessels; S. Wagner; K. Kaminski; T. Brand; Werres S.

2008-01-01

In a four year project, three different filtration systems were tested under commercial nursery conditions to eliminate Phytophthora spp. from irrigation water. Five nurseries were involved in the project. Slow sand filtration systems were tested in three nurseries. In the fourth nursery, a filtration system with lava grains (Shieer® Bio filtration)...

Glomerular filtration values obtained with 99mTc-DTPA v/s measurements of creatinine Clearance and calculation of the filtered glomerular using the Schwartz formula in a pediatric population

International Nuclear Information System (INIS)

Opazo, Claudio; Gutierrez, Elisa; Zamorano, Julio; Troncoso, TM

2005-01-01

We compare glomerular filtration rate by DTPA Renogram (DTPA-GFR) with creatinine clearance (CC) and Glomerular filtration rate from Schwartz formula (Schwartz-GFR). The need for using (DTPA-GFR) method raised from the practical difficulties in getting an accurate (CC) in pediatric population. From Sep-2001 to May-2005, 48 patients aged 1month to 18 years, underwent (DTPA-GFR) and (Schwartz-GFR). 18 had also (CC). Comparison were made among these measurements also accounting for age groups. We found a better correlation between (DTPA-GFR) and (CC) Pearson = 0,895. (Schwartz)/(CC) comparison showed a slightly lower correlation Pearson = 0,857. The worst correlation was found comparing (DTPA-GFR)/(Schwartz-GFR) in children < 3 yr Pearson = 0,560. As we found a better correlation between (DTPA-GFR)/(CC) than (DTPA-GFR)/(Schwartz-GFR), DTPA-GFR could be considered reliable method in evaluating renal function in children having difficulties to get a Creatinine Clearance (au)

Water Clarity Simulant for K East Basin Filtration Testing

Energy Technology Data Exchange (ETDEWEB)

Schmidt, Andrew J.

2006-01-20

This document provides a simulant formulation intended to mimic the behavior of the suspended solids in the K East (KE) Basin fuel storage pool. The simulant will be used to evaluate alternative filtration apparatus to improve Basin water clarity and to possibly replace the existing sandfilter. The simulant was formulated based on the simulant objectives, the key identified parameters important to filtration, the composition and character of the KE Basin suspended sludge particles, and consideration of properties of surrogate materials.

Development of electromagnetic filtration in the feed water circuits

International Nuclear Information System (INIS)

Dolle, L.

1980-01-01

Electromagnetic filtration in the feed water circuit of the steam generators in nuclear power plants is efficient towards insoluble corrosion products. The principle of electromagnetic filtration is shortly recalled and the results of corresponding development work are summarized. The magnitude of water volumes to be treated on the two priviledged parts of the circuit are estimated. These parts are on the feed water tank level and on the blow-down of the steam generator. The practical applications are discussed [fr

Detergent zeolite filtration plant

OpenAIRE

Stanković Mirjana S.; Pezo Lato L.

2003-01-01

The IGPC Engineering Department designed basic projects for detergent zeolite filtration plant, using technology developed in the IGPC laboratories. Several projects were completed: technological, machine, electrical, automation. On the basis of these projects, a production plant with a capacity of 75,000 t/y was manufactured, at "Zeolite Mira", Mira (VE), Italy, in 1997, for increasing detergent zeolite production, from 50,000 to 100,000 t/y. The main goal was to increase the detergent zeoli...

21 CFR 211.46 - Ventilation, air filtration, air heating and cooling.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 4 2010-04-01 2010-04-01 false Ventilation, air filtration, air heating and cooling. 211.46 Section 211.46 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN... Buildings and Facilities § 211.46 Ventilation, air filtration, air heating and cooling. (a) Adequate...

Rheological and filtration characteristics of drilling fluids enhanced by nanoparticles with selected additives: an experimental study

Directory of Open Access Journals (Sweden)

Nima Mohamadian

2018-05-01

Full Text Available The suspension properties of drilling fluids containing pure and polymer-treated (partially-hydrolyzed polyacrylamide (PHPA or Xanthan gum clay nanoparticles are compared withthose of a conventional water-and-bentonite-based drilling fluid, used as the referencesample. Additionally, the mud weight, plastic viscosity, apparent viscosity, yield point, primary and secondary gelatinization properties, pH, and filtration properties of the various drilling fluids studied are also measured and compared. The performance of each drilling fluid type is evaluated with respect in terms of its ability to reduce mud cake thickness and fluid loss thereby inhibiting differential-pipe-sticking. For that scenario, the mud-cake thickness is varied, and the filtration properties of the drilling fluids are measured as an indicator of potential well-diameter reduction, caused by mud cake, adjacent to permeable formations. The novel results show that nanoparticles do significantly enhance the rheological and filtration characteristics of drilling fluids. A pure-clay-nanoparticle suspension, without any additives, reduced fluid loss to about 42% and reduced mud cake thickness to 30% compared to the reference sample. The xanthan-gum-treated-clay-nanoparticle drilling fluid showed good fluid loss control and reduced fluid loss by 61% compared to the reference sample. The presence of nanofluids also leads to reduced mud-cake thicknesses, directly mitigating the risks of differential pipe sticking.

On the possibility of separation of valuable components from chloride pulps by filtration

International Nuclear Information System (INIS)

Chub, A.V.; Zelenkov, B.N.; Zakharov, V.F.; Drobot, D.V.

1977-01-01

The possibility has been studied of extracting MCl 5 (M=Nb, Ta) from technical products (chloride pulps in TiCl 4 ) by filtration. It has been established that in a low temperature range (( 5 . With increasing temperature a mutual presence of niobium and tantalum chlorides decreases the total content of MCl 5 in the solution. It has also been found that the filtration rate is proportional to pressure; besides, ''the aged'' precipitates possess worse filtrating properties due to particle destruction. Materials of the fiber glass fabric type are a good base for applying the precipitate. At a layer thickness of the chloride (MCl 5 ) precipitate about 20 mm a sufficiently high filtration rate is ensured

Evaluation of particulate filtration efficiency of retrofit particulate filters for light duty vehicles

International Nuclear Information System (INIS)

Van Asch, R.; Verbeek, R.

2009-10-01

In the light of the currently running subsidy programme for particulate filters in the Netherlands, the Dutch ministry of spatial planning and environment (VROM) asked TNO to execute a desk study to evaluate the particulates filtration efficiency of retrofit particulate filters for light duty vehicles (passenger cars and vans). The typical retrofit particulate filters for light duty vehicles are also called 'open' or 'half-open' filters, because a part of the exhaust gas can pass through the particulate filter unfiltered. From design point they are very different from the majority of the factory installed particulate filters, which are also called wall-flow or 'closed' particulate filters. Due to these differences there is a large difference in filtration efficiency. Whereas the 'dosed' particulate filters show a filtration efficiency of larger than 90%, the filtration efficiency of 'open' particulate filters is generally lower (type approval minimum 30%), and strongly dependent on the conditions of use. The objective of the current project was to assess the average filtration efficiency of retrofit (open) particulate fillters on light duty vehicles in real world day to day driving, based on available literature data. Also, the reasons of a possible deviation with the type approval test results (minimum filtration efficiency of 30%) was investigated.

Filtration set for gaseous fluids

International Nuclear Information System (INIS)

Lebrun, B.; Couvrat-Desvergnes, A.

1988-01-01

This filtration set is made by a cylindrical vessel containing upstairs to downstairs, the gas inlet, a sealed floor for man inspection, a horizontal granular filter bed, a linen with a porosity inferior to the granulometry of the filter bed, a light support layer of material of larger granulometry, gas permeable tubes and an annular collector connecting the tubes to the outlet [fr

Hydrophilicity improvement in polyphenylsulfone nanofibrous filtration membranes through addition of polyethylene glycol

Energy Technology Data Exchange (ETDEWEB)

Kiani, Shirin [Department of Chemical Engineering, Faculty of Engineering, Ferdowsi University of Mashhad, Mashhad (Iran, Islamic Republic of); Membrane Processes and Membrane Research Center, Faculty of Engineering, Ferdowsi University of Mashhad, Mashhad (Iran, Islamic Republic of); Mousavi, Seyed Mahmoud, E-mail: mmousavi@um.ac.ir [Department of Chemical Engineering, Faculty of Engineering, Ferdowsi University of Mashhad, Mashhad (Iran, Islamic Republic of); Shahtahmassebi, Nasser [Department of Physics, Faculty of Science, Ferdowsi University of Mashhad, Mashhad (Iran, Islamic Republic of); Nanoresearch Center, Ferdowsi University of Mashhad, Mashhad (Iran, Islamic Republic of); Saljoughi, Ehsan [Department of Chemical Engineering, Faculty of Engineering, Ferdowsi University of Mashhad, Mashhad (Iran, Islamic Republic of)

2015-12-30

Highlights: • Novel hydrophilic polyphenylsulfone electrospun nanofibrous membrane was prepared. • Blending the PPSU solution with 10 wt.% PEG 400 led to the optimum results. • Water contact angle of the optimum membrane was determined as 8.9°. • Remarkable increase in pure water flux and flux recovery was achieved. • Rejection values of the wastewater pollution indices remained almost unchanged. - Abstract: Novel hydrophilic polyphenylsulfone (PPSU) nanofibrous membrane was prepared by electrospinning of the PPSU solution blended with polyethylene glycol 400 (PEG 400). The influence of the PEG concentration on the membrane characteristics was studied using scanning electron microscopy (SEM), water contact angle measurement, and tensile test. Filtration performance of the membranes was investigated by measurement of pure water flux (PWF) and determination of the rejection values of the pollution indices during treatment of canned beans production wastewater. According to the results, blending the PPSU solution with 10 wt.% PEG 400 resulted in formation of a nanofibrous membrane with high porosity and increased mechanical strength which exhibited a low water contact angle of 8.9° and high water flux of 7920 L/m{sup 2}h. Flux recovery of the mentioned membrane which was assessed by filtration of a solution containing bovine serum albumin (BSA) was 83% indicating a noticeable antifouling property.

Students' Perception of Live Lectures' Inherent Disadvantages

Science.gov (United States)

Petrovic, Juraj; Pale, Predrag

2015-01-01

This paper aims to provide insight into various properties of live lectures from the perspective of sophomore engineering students. In an anonymous online survey conducted at the Faculty of Electrical Engineering and Computing, University of Zagreb, we investigated students' opinions regarding lecture attendance, inherent disadvantages of live…

Experimental study on filtration and continuous regeneration of a particulate filter system for heavy-duty diesel engines.

Science.gov (United States)

Tang, Tao; Zhang, Jun; Cao, Dongxiao; Shuai, Shijin; Zhao, Yanguang

2014-12-01

This study investigated the filtration and continuous regeneration of a particulate filter system on an engine test bench, consisting of a diesel oxidation catalyst (DOC) and a catalyzed diesel particulate filter (CDPF). Both the DOC and the CDPF led to a high conversion of NO to NO2 for continuous regeneration. The filtration efficiency on solid particle number (SPN) was close to 100%. The post-CDPF particles were mainly in accumulation mode. The downstream SPN was sensitively influenced by the variation of the soot loading. This phenomenon provides a method for determining the balance point temperature by measuring the trend of SPN concentration. Copyright © 2014. Published by Elsevier B.V.

Effect of treatment with reserpine on the change in filtration rate of Mytilus edulis subjected to dissolved copper

Energy Technology Data Exchange (ETDEWEB)

Howell, R.; Grant, A.M.; Maccoy, N.E.J.

1984-12-01

Exposure of specimens of Mytilus edulis to dissolved copper leads to a fall in the filtration rate measured in whole animals. The copper concentration leading to a 50% reduction in the filtration rate was found to be 0.094 mg I/sup -1/. This effect was abolished on depletion of the monoamine content of the animal using reserpine. It is suggested that there may be a chemosensory mechanism present in the animals which responds to increased levels of metals in the seawater leading to a reduction in the rate of ciliary beating and mediated via the branchial nerve. 15 references, 2 figures.

Mannitol increases renal blood flow and maintains filtration fraction and oxygenation in postoperative acute kidney injury: a prospective interventional study.

Science.gov (United States)

Bragadottir, Gudrun; Redfors, Bengt; Ricksten, Sven-Erik

2012-08-17

Acute kidney injury (AKI), which is a major complication after cardiovascular surgery, is associated with significant morbidity and mortality. Diuretic agents are frequently used to improve urine output and to facilitate fluid management in these patients. Mannitol, an osmotic diuretic, is used in the perioperative setting in the belief that it exerts reno-protective properties. In a recent study on uncomplicated postcardiac-surgery patients with normal renal function, mannitol increased glomerular filtration rate (GFR), possibly by a deswelling effect on tubular cells. Furthermore, experimental studies have previously shown that renal ischemia causes an endothelial cell injury and dysfunction followed by endothelial cell edema. We studied the effects of mannitol on renal blood flow (RBF), glomerular filtration rate (GFR), renal oxygen consumption (RVO2), and extraction (RO2Ex) in early, ischemic AKI after cardiac surgery. Eleven patients with AKI were studied during propofol sedation and mechanical ventilation 2 to 6 days after complicated cardiac surgery. All patients had severe heart failure treated with one (100%) or two (73%) inotropic agents and intraaortic balloon pump (36%). Systemic hemodynamics were measured with a pulmonary artery catheter. RBF and renal filtration fraction (FF) were measured by the renal vein thermo-dilution technique and by renal extraction of chromium-51-ethylenediaminetetraacetic acid (51Cr-EDTA), respectively. GFR was calculated as the product of FF and renal plasma flow RBF × (1-hematocrit). RVO2 and RO2Ex were calculated from arterial and renal vein blood samples according to standard formulae. After control measurements, a bolus dose of mannitol, 225 mg/kg, was given, followed by an infusion at a rate of 75 mg/kg/h for two 30-minute periods. Mannitol did not affect cardiac index or cardiac filling pressures. Mannitol increased urine flow by 61% (P renal vascular resistance (P renal FF. Mannitol treatment of postoperative AKI

Apparatus for Crossflow Filtration Testing of High Level Waste Samples

International Nuclear Information System (INIS)

Nash, C.

1998-05-01

Remotely-operated experimental apparatuses for verifying crossflow filtration of high level nuclear waste have been constructed at the Savannah River Site (SRS). These units have been used to demonstrate filtration processes at the Savannah River Site, Oak Ridge National Laboratory, the Idaho National Engineering and Environmental Laboratory, and Pacific Northwest National Laboratory. The current work covers the design considerations for experimentation as well as providing results from testing at SRS

Cast Steel Filtration Trials Using Ceramic-Carbon Filters

Directory of Open Access Journals (Sweden)

Lipowska B.

2014-12-01

Full Text Available Trials of cast steel filtration using two types of newly-developed foam filters in which carbon was the phase binding ceramic particles have been conducted. In one of the filters the source of carbon was flake graphite and coal-tar pitch, while in the other one graphite was replaced by a cheaper carbon precursor. The newly-developed filters are fired at 1000°C, i.e. at a much lower temperature than the currently applied ZrO2-based filters. During filtration trials the filters were subjected to the attack of a flowing metal stream having a temperature of 1650°C for 30 seconds.

Graphite beds for coolant filtration at high temperature

International Nuclear Information System (INIS)

Heathcock, R.E.; Lacy, C.S.

1978-01-01

High temperature filtration will be provided for new Ontario Hydro CANDU heat transport systems. Filtration has been shown to effectively reduce the concentration of circulating corrosion products in our heat transport systems, hence, minimizing the processes of activity transport. This paper will present one option we have for this application; Deep Bed Granular Graphite Filters. The filter system is described by discussing pertinent aspects of its development programme. The compatibility of the filter and the heat transport coolant are demonstrated by results from loop tests, both out- and in-reactor, and by subsequent results from a large filter installation in the NPD NGS heat transport system. (author)

Measured glomerular filtration rate at dialysis initiation and clinical outcomes of Indian peritoneal dialysis patients

Directory of Open Access Journals (Sweden)

N Prasad

2017-01-01

Full Text Available The optimal time for dialysis initiation remains controversial. Studies have failed to show better outcomes with early initiation of hemodialysis; even a few had shown increased adverse outcomes including poorer survival. Few studies have examined the same in patients on peritoneal dialysis (PD. Measured glomerular filtration rate (mGFR not creatinine-based estimated GFR is recommended as the measure of kidney function in end-stage renal disease (ESRD patients. The objective of this observational study was to compare the outcomes of Indian patients initiated on PD with different residual renal function (RRF as measured by 24-h urinary clearance method. A total of 352 incident patients starting on chronic ambulatory PD as the first modality of renal replacement therapy were followed prospectively. Patients were categorized into three groups as per mGFR at the initiation of PD (≤5, >5–10, and> 10 ml/min/1.73 m2. Patient survival and technique survival were compared among the three groups. Patients with GFR of ≤5 ml/min/1.73 m2 (hazard ratio [HR] - 3.42, 95% confidence interval [CI] - 1.85–6.30, P = 0.000 and> 5–10 ml/min/1.73 m2 (HR - 2.16, 95% CI - 1.26–3.71, P = 0.005 had higher risk of mortality as compared to those with GFR of> 10 ml/min/1.73 m2. Each increment of 1 ml/min/1.73 m2 in baseline GFR was associated with 10% reduced risk of death (HR - 0.90, 95% CI - 0.85–0.96, P = 0.002. Technique survival was poor in those with an initial mGFR of ≤5 ml/min/1.73 m2 as compared to other categories. RRF at the initiation was also an important factor predicting nutritional status at 1 year of follow-up. To conclude, initiation of PD at a lower baseline mGFR is associated with poorer patient and technique survival in Indian ESRD patients.

Diatomite releases silica during spirit filtration.

Science.gov (United States)

Gómez, J; Gil, M L A; de la Rosa-Fox, N; Alguacil, M

2014-09-15

The purpose of this study was to ascertain whether diatomite is an inert filter aid during spirit filtration. Surely, any compound with a negative effect on the spirit composition or the consumer's health could be dissolved. In this study different diatomites were treated with 36% vol. ethanol/water mixtures and the amounts and structures of the extracted compounds were determined. Furthermore, Brandy de Jerez was diatomite- and membrane-filtered at different temperatures and the silicon content was analysed. It was found that up to 0.36% by weight of diatomite dissolved in the aqueous ethanol and amorphous silica, in the form of hollow spherical microparticles, was the most abundant component. Silicon concentrations in Brandy de Jerez increased by up to 163.0% after contact with diatomite and these changes were more marked for calcined diatomite. In contrast, reductions of more than 30% in silicon concentrations were achieved after membrane filtration at low temperatures. Copyright © 2014 Elsevier Ltd. All rights reserved.

Iron behavior in the ozonation and filtration of groundwater

Energy Technology Data Exchange (ETDEWEB)

Sallanko, J.; Lakso, E.; Ropelinen, J. [University of Oulu, Oulu (Finland)

2006-08-15

In Finnish groundwater, the main substances that require treatment are iron and manganese. In addition to this, groundwaters are soft and acidic. Iron removal is usually relatively effective by oxidizing dissolved iron into an insoluble form, either by aeration or chemical oxidation and removing the formed precipitate by sand filtration. Sometimes, if the untreated water contains high amounts of organic matter, problems may arise for iron removal. In Finland, it is quite common that groundwater contains high levels of both iron and natural organic matter, mainly as humic substances. The groundwater of the Kukkala intake plant in Liminka has been found to be problematic, due to its high level of natural organic matter. This research studied the removal of iron from this water by means of oxidation with ozone and filtration. While the oxidation of iron by ozone was rapid, the precipitate particles formed were small, and thus could not be removed by sand and anthracite filtration, and the iron residue in the treated water was more than 2 mg L{sup -1}. And while the filtration was able to remove iron well without the feed of ozone, the iron residue in the treated water was only 0.30 mg L{sup -1}. In this case, iron was led to the filter in a bivalent dissolved form. So, the result of iron removal was the best when the sand/anthracite filter functioned largely as an adsorption filter.

Effect of phosphate ion on filtration characteristics of solids generated in simulated high level liquid waste

International Nuclear Information System (INIS)

Kondo, Y.

1998-01-01

The effect of phosphate ion on the filtration characteristics of solids generated in a high level liquid waste was experimentally examined. Addition of phosphate ion into the simulated HLLW induced the formation of phosphate such as zirconium phosphate and phosphomolybdic acid. The filtration rate of zirconium phosphate abruptly dropped in the midst of filtration because of a gel-cake formation on the filter surface. The denitration of the simulated HLLW contained zirconium phosphate improved the filterability of this gelatinous solid. The filtration rates of denitrated HLLW decreased with increase of the phosphate ion concentration, since the solids formed by denitration had irregular particle size and configuration in the simulated HLLW with phosphate ion. To increase the filtration rate of denitrated HLLW, a solid suspension filtration tester was designed. The solid-suspension accelerated the filtration rate only in the simulated HLLW with more than 1500 ppm phosphate ion concentration. Under this condition, the simple agitation can easily suspend the constituent solids of filter cake in the solution and a much higher filtration rate can be obtained because the filter cake is continuously swept from the filter surface by rotation of propellers. (authors)

Separation of nanoparticles: Filtration and scavenging from waste incineration plants.

Science.gov (United States)

Förster, Henning; Thajudeen, Thaseem; Funk, Christine; Peukert, Wolfgang

2016-06-01

Increased amounts of nanoparticles are applied in products of everyday life and despite material recycling efforts, at the end of their life cycle they are fed into waste incineration plants. This raises the question on the fate of nanoparticles during incineration. In terms of environmental impact the key question is how well airborne nanoparticles are removed by separation processes on their way to the bag house filters and by the existing filtration process based on pulse-jet cleanable fibrous filter media. Therefore, we investigate the scavenging and the filtration of metal nanoparticles under typical conditions in waste incineration plants. The scavenging process is investigated by a population balance model while the nanoparticle filtration experiments are realized in a filter test rig. The results show that depending on the particle sizes, in some cases nearly 80% of the nanoparticles are scavenged by fly ash particles before they reach the bag house filter. For the filtration step dust cakes with a pressure drop of 500Pa or higher are found to be very effective in preventing nanoparticles from penetrating through the filter. Thus, regeneration of the filter must be undertaken with care in order to guarantee highly efficient collection of particles even in the lower nanometre size regime. Copyright © 2016 Elsevier Ltd. All rights reserved.

AN AMELIORATED DETECTION STATISTICS FOR ADAPTIVE MASK MEDIAN FILTRATION OF HEAVILY NOISED DIGITAL IMAGES

Directory of Open Access Journals (Sweden)

Geeta Hanji

2016-11-01

Full Text Available Noise reduction is an important area of research in image processing applications. The performance of the digital image noise filtering method primarily depends upon the accuracy of noise detection scheme. This paper presents an effective detector based, adaptive mask, median filtration of heavily noised digital images affected with fixed value (or salt and pepper impulse noise. The proposed filter presents a novel approach; an ameliorated Rank Ordered Absolute Deviation (ROAD statistics to judge whether the input pixel is noised or noise free. If a pixel is detected as corrupted, it is subjected to adaptive mask median filtration; otherwise, it is kept unchanged. Extensive experimental results and comparative performance evaluations demonstrate that the proposed filter outperforms the existing decision type, median based filters with powerful noise detectors in terms of objective performance measures and visual retrieviation accuracy.

Efektifitas Riverbank Filtration Trhadap Parameter Fisik (TDS di Sungai Cihideung

Directory of Open Access Journals (Sweden)

Roh Santoso Budi Waspodo

2013-01-01

Full Text Available Water is a natural resource that is necessary for the livelihood of many people, even by all living things. Data Ministry of Public Works in 2006 mentions the availability of water in Indonesia amounted to 15,500 cubic meters per capita per year, far higher than the global availability averaged only 600 m3. If drawn, the amount of water covers 21% of Indonesia Pacific Ocean. However, the overflow Indonesia does not necessarily solve the problem of water crisis which is also predicted to fall on two major islands in 2015. The general objective of this research is to develop and implement technological innovations RBF (Riverbank Filtration to support the needs of irrigation water Watershed Cisadane, making RBF (Riverbank Filtration as a natural water treatment in Cisadane River area, and water quality data information through RBF (Riverbank Filtration Cisadane Watershed.

Comparative evaluation of iohexol and inulin clearance for glomerular filtration rate determinations

International Nuclear Information System (INIS)

Lindblad, H.G.; Berg, U.B.

1994-01-01

The authors have evaluated iohexol as a filtration marker in 150 children. The clearance of iohexol was compared with that of inulin or with a formula clearance. The single-sample clearance of iohexol showed a good correlation with the clearance of inulin. The clearance of iohexol correlated well with the formula clearance. The optimal blood sampling time for iohexol clearance determinations appears to be between 120 and 180 min after injection, at least in patient with relatively normal filtration rates. It is concluded that iohexol clearance is an accurate method of determining the glomerular filtration rate in clinical practice. 25 refs., 5 figs

Filtration Characterization Method as Tool to Assess Membrane Bioreactor Sludge Filterability—The Delft Experience

Directory of Open Access Journals (Sweden)

Maria Lousada-Ferreira

2014-04-01

Full Text Available Prevention and removal of fouling is often the most energy intensive process in Membrane Bioreactors (MBRs, responsible for 40% to 50% of the total specific energy consumed in submerged MBRs. In the past decade, methods were developed to quantify and qualify fouling, aiming to support optimization in MBR operation. Therefore, there is a need for an evaluation of the lessons learned and how to proceed. In this article, five different methods for measuring MBR activated sludge filterability and critical flux are described, commented and evaluated. Both parameters characterize the fouling potential in full-scale MBRs. The article focuses on the Delft Filtration Characterization method (DFCm as a convenient tool to characterize sludge properties, namely on data processing, accuracy, reproducibility, reliability, and applicability, defining the boundaries of the DFCm. Significant progress was made concerning fouling measurements in particular by using straight forward approaches focusing on the applicability of the obtained results. Nevertheless, a fouling measurement method is still to be defined which is capable of being unequivocal, concerning the fouling parameters definitions; practical and simple, in terms of set-up and operation; broad and useful, in terms of obtained results. A step forward would be the standardization of the aforementioned method to assess the sludge filtration quality.

Graphene nanoplatelets as high-performance filtration control material in water-based drilling fluids

Science.gov (United States)

Ridha, Syahrir; Ibrahim, Arif; Shahari, Radzi; Fonna, Syarizal

2018-05-01

The main objective of this work is to evaluate the effectiveness of graphene nanoplatelets (GNP) as filtration control materials in water based drilling fluids. Three (3) general samples of water based drilling fluids were prepared including basic potassium chloride (KCl) drilling fluids, nanosilica (NS) drilling fluids and GNP drilling fluids. Several concentrations of NS and GNP were dispersed in controlled formulations of water based drilling fluids. Standard API filtration tests were carried out for comparison purposes as well as High Temperature High Pressure (HTHP) filtration tests at 150 °F (∼66 °C), 250 °F (∼121 °C) and 350 °F (∼177 °C) at a fixed 500 (∼3.45MPa) psi to study the filtration trend as a function of temperature. Mud cake samples from several tests were selectively chosen and analyzed under Field Emission Scanning Electron Microscope (FESEM) for its morphology. Results from this work show that nanoparticle concentrations play a factor in filtration ability of colloid materials in water based drilling fluids when studied at elevated temperature. Low temperature filtration, however, shows only small differences in volume in all the drilling fluid samples. 0.1 ppb concentrations of GNP reduced the fluid loss of 350 °F by 4.6 mL as compared to the similar concentration of NS drilling fluids.

Observation and analysis of water inherent optical properties

Science.gov (United States)

Sun, Deyong; Li, Yunmei; Le, Chengfeng; Huang, Changchun

2008-03-01

Inherent optical property is an important part of water optical properties, and is the foundation of water color analytical model establishment. Through quantity filter technology (QFT) and backscattering meter BB9 (WETlabs Inc), absorption coefficients of CDOM, total suspended minerals and backscattering coefficients of total suspended minerals had been observed in Meiliang Bay of Taihu lake at summer and winter respectively. After analyzing the spectral characteristics of absorption and backscattering coefficients, the differences between two seasons had been illustrated adequately, and the reasons for the phenomena, which are related to the changes of water quality coefficient, had also been explained. So water environment states can be reflected by inherent optical properties. In addition, the relationship models between backscattering coefficients and suspended particle concentrations had been established, which can support coefficients for analytical models.

Digital Marketing concept and strategy for a Finnish Start-up, Case: Sofi Filtration

OpenAIRE

Buda, Constantin

2014-01-01

The case company is a Finnish start-up company that operates in the industrial water filtration business and who aims to increase its brand awareness and generate more sales leads. The aim of this study is to provide effective and inexpensive tools for Sofi Filtration to engage its target audience and grow its business by being acknowledged as an expert in industrial water filtration. The thesis is part of the International Business Management program offered by HAAGA-HELIA University of ...

Rapid decline in glomerular filtration rate during the first weeks following heart transplantation

DEFF Research Database (Denmark)

Hornum, M; Andersen, M; Gustafsson, F

2011-01-01

We hypothesized that a decrease in renal function is seen immediately after heart transplantation (HTX) with little recovery over time. Twelve consecutive patients had their glomerular filtration rate (GFR) measured using (51)Cr-ethylenediaminetetraacetic acid (EDTA) measured GFR (mGFR) before...... transplantation and at 1, 2, 3, and 26 weeks after transplantation. The mGFR decreased by 28% and 24% during the first 3 and 26 weeks, respectively, with mean blood cyclosporine concentration as an independent risk factor for the decrease in mGFR. The identification of cyclosporine A (CsA) as the most important...

Inherent reward & risk (Part I): Towards a universal paradigm for investment analysis

NARCIS (Netherlands)

Zou, L.

2000-01-01

In this paper, a new paradigm is developed for analyzinginvestment strategies and pricing financial assets. This paradigmassumes that any investment strategy has its own "inherent reward"and "inherent risk" that can be judged with common sense. Ijustify axiomatically the existence and uniqueness

Dynamic membrane filtration in tangential flow

International Nuclear Information System (INIS)

Anon.

1993-01-01

Oil-containing waste water is produced in many cleaning processes and also on production of compressed air. Dynamic membrane filtration in the tangential flow mode has proved effective in the treatment of these stable emulsions. The possible applications of ceramic membrane filters are illustrated for a variety of examples. (orig.) [de

In Vitro Selection of Peanut Somatic Embryos on Medium Containing Culture Filtrate of Sclerotium rolfsii and Plantlet Regeneration

Directory of Open Access Journals (Sweden)

YUSNITA

2005-06-01

Full Text Available Attempts to identify somaclonal variants of peanut with resistance to Sclerotium stem rot disease due to infection of S. rolfsii were conducted. The objectives of this study were to develop in vitro selection method using culture filtrates of S. rolfsii, identify culture filtrate-insensitive somatic embryo (SE of peanut after in vitro selection and regenerate peanut R0 lines originated from culture filtrate-insensitive SE. To achieve these objectives, peanut embryogenic tissues were cultured on selective medium containing various concentrations of S. rolfsii culture filtrates and sublethal concentration of the filtrates. Medium containing sublethal level of S. rolfsii culture filtrates was used to identify culture filtrate-insensitive SE of peanut. Subsequently, the selected SEs were germinated, plantlets were regenerated and preliminary tested against S. rolfsii. Results of the experiments showed that addition of S. rolfsii culture filtrates into medium for inducing peanut somatic embryos drastically reduced their growth and proliferation. S. rolfsii culture filtrates at 10% concentration has significantly reduced the number of proliferated SE per explant. However, sublethal level was achieved at 30% of culture filtrates concentration. Responses of five peanut cultivars against 30% of culture filtrates were similar, indicating they were similar in their susceptibility against S. rolfsii. A number of culture filtrate-insensitive SE were identified after culturing 1500 clumps of embryogenic tissue of peanut cv. Kelinci for three consecutive passages on medium containing 30% of culture filtrates. Germination of selected SE and regeneration of plantlet from culture filtrate-insensitive SE resulted in 50 peanut R0 lines. These lines have been grown in the plastic house and produced normal seeds for further evaluation. Results of S. rolfsii inoculation indicated the existence of chimera for insensitivity against S. rolfsii.

Probabilities of inherent shutdown of unprotected events in innovative liquid metal reactors

International Nuclear Information System (INIS)

Mueller, C.J.; Wade, D.C.

1988-01-01

The uncertainty in predicting the effectiveness of inherent shutdown in innovative liquid metal cooled reactors with metallic fuel results from three broad contributing areas of uncertainty: (1) the inability to exactly predict the frequency of ATWS events with potential to challenge the safety systems and require inherent shutdown; (2) the approximation of representing all such events by a selected set of ''generic scenarios''; and (3) the inability to exactly calculate the core response to the selected generic scenarios. This paper discusses the work being done to address each of these contributing areas, identifies the design and research approaches being used at Argonne National Laboratory to reducing the key contributions to uncertainties in inherent shutdown, and presents results. The conditional probabilities (given ATWS initiation) of achieving temperatures capable of defeating inherent shutdown are shown to range from /approximately/0.1% to negligible for current designs

Ordeals of Chernobyl and the rejustification of the inherently safe reactors

International Nuclear Information System (INIS)

Lu, Y.

1989-01-01

This paper presents the necessity of developing inherently safe economic reactors (ISERs). Two characteristics which define inherent safety are discussed on the basis of various applications of such a principle in practice. Different design concepts of ISERs are then evaluated and their possible role in the future nuclear program of PRC discussed. A three-stage development strategy of ISERs in PRC is proposed

Riverbank Filtration: A Sustainable Process to Attenuate Contaminants during Drinking Water Production

Directory of Open Access Journals (Sweden)

Pradeep Kumar

2018-03-01

Full Text Available Riverbank filtration leads to purification of water. For India it can be a simple, economical and effective alternative. A few unanswered questions were: Can it work in Indian mountainous regions? Will it be of any advantage in the case of some of the polluted Indian surface waters? With the goal to evaluate use of riverbank filtration as a sustainable technology under widely varying conditions prevalent in India, the effectiveness of riverbank filtration has been examined over the last 10 years. In the case of cleaner surface waters, the wells deliver water free of turbidity and coliform even during monsoon irrespective of well configuration. In the case of polluted source waters, it results in an overall advantage in terms of improved raw water quality, reduced degree and cost of subsequent treatment and decreased levels of disinfection by-products. The study shows riverbank filtration to be an effective and sustainable option for plains as well as the mountainous region.

The effects of cimetidine on creatinine excretion, glomerular filtration rate and tubular function in renal transplant recipients

DEFF Research Database (Denmark)

Olsen, N V; Ladefoged, S D; Feldt-Rasmussen, B

1989-01-01

The renal clearance of endogenous creatinine (CCr), sodium (CNa) and lithium (CLi) was determined before and after a single intravenous bolus of cimetidine in nine renal transplant recipients. The glomerular filtration rate (GFR) was measured with 125I-iothalamate clearance (CTh). The initial CCr...... of 65 ml/min (median) was reduced to a nadir of 46 ml/min (p less than 0.01) during the first 2 h after infusion of cimetidine. GFR remained unchanged, and thus the fractional clearance of creatinine (CCr/CTh) was reduced from 1.43 (median) to 1.03 (p less than 0.01). CNa and the fractional excretion...... of sodium decreased throughout the study (p less than 0.05); CLi was unchanged. In conclusion cimetidine, when measured during 1-h clearance periods, interferes with tubular creatinine secretion in the denervated kidney of transplant recipients without affecting the glomerular filtration rate or proximal...

Centrifugal Filtration System for Severe Accident Source Term Treatment

Energy Technology Data Exchange (ETDEWEB)

Liu, Shu Chang; Yim, Man Sung [KAIST, Daejeon (Korea, Republic of)

2016-05-15

The objective of this paper is to present the conceptual design of a filtration system that can be used to process airborne severe accident source term. Reactor containment may lose its structural integrity due to over-pressurization during a severe accident. This can lead to uncontrolled radioactive releases to the environment. For preventing the dispersion of these uncontrolled radioactive releases to the environment, several ways to capture or mitigate these radioactive source term releases are under investigation at KAIST. Such technologies are based on concepts like a vortex-like air curtain, a chemical spray, and a suction arm. Treatment of the radioactive material captured by these systems would be required, before releasing to environment. For current filtration systems in the nuclear industry, IAEA lists sand, multi-venturi scrubber, high efficiency particulate arresting (HEPA), charcoal and combinations of the above in NS-G-1-10, 4.143. Most if not all of the requirements of the scenario for applying this technology near the containment of an NPP site and the environmental constraints were analyzed for use in the design of the centrifuge filtration system.

The influence of zeta potential and yield stress on the filtration characteristics of a magnesium hydroxide simulant

International Nuclear Information System (INIS)

Biggs, Simon; Nabi, Rafiq; Poole, Colin; Patel, Ashok

2007-01-01

In the UK, irradiated fuels from Magnox reactors are often stored in water-filled ponds under alkaline conditions, so as to minimise corrosion of fuel cladding. This is important to prevent or reduce leakage of soluble fission products and actinides to the pond water. A variety of intermediate level wastes derived from Magnox materials are stored at power stations. Under these alkaline conditions, various species of magnesium are formed, of which magnesium hydroxide is the dominant material. The particle-fluid interactions are significant for the design and operation of facilities for hydraulic retrieval, filtration, dewatering and ion exchange treatment of fuel storage pond water and stored wet Magnox wastes. Here we describe a study of particulate properties and filtration characteristics of oxide particle simulants under laboratory conditions. Cake and medium resistance data were correlated across a range of pH conditions with electro-acoustic zeta potential and shear yield stress measurements, as a function of particle volume fractions. The influence of zeta potential on filtration properties arises directly from the interaction of particles within the sediment cake. (authors)

Safety assessment in plant layout design using indexing approach: Implementing inherent safety perspective

International Nuclear Information System (INIS)

Tugnoli, Alessandro; Khan, Faisal; Amyotte, Paul; Cozzani, Valerio

2008-01-01

Layout planning plays a key role in the inherent safety performance of process plants since this design feature controls the possibility of accidental chain-events and the magnitude of possible consequences. A lack of suitable methods to promote the effective implementation of inherent safety in layout design calls for the development of new techniques and methods. In the present paper, a safety assessment approach suitable for layout design in the critical early phase is proposed. The concept of inherent safety is implemented within this safety assessment; the approach is based on an integrated assessment of inherent safety guideword applicability within the constraints typically present in layout design. Application of these guidewords is evaluated along with unit hazards and control devices to quantitatively map the safety performance of different layout options. Moreover, the economic aspects related to safety and inherent safety are evaluated by the method. Specific sub-indices are developed within the integrated safety assessment system to analyze and quantify the hazard related to domino effects. The proposed approach is quick in application, auditable and shares a common framework applicable in other phases of the design lifecycle (e.g. process design). The present work is divided in two parts: Part 1 (current paper) presents the application of inherent safety guidelines in layout design and the index method for safety assessment; Part 2 (accompanying paper) describes the domino hazard sub-index and demonstrates the proposed approach with a case study, thus evidencing the introduction of inherent safety features in layout design

Long range stress correlations in the inherent structures of liquids at rest

Energy Technology Data Exchange (ETDEWEB)

Chowdhury, Sadrul; Abraham, Sneha; Hudson, Toby; Harrowell, Peter [School of Chemistry, University of Sydney, Sydney, NSW 2006 (Australia)

2016-03-28

Simulation studies of the atomic shear stress in the local potential energy minima (inherent structures) are reported for binary liquid mixtures in 2D and 3D. These inherent structure stresses are fundamental to slow stress relaxation and high viscosity in supercooled liquids. We find that the atomic shear stress in the inherent structures (IS’s) of both liquids at rest exhibits slowly decaying anisotropic correlations. We show that the stress correlations contribute significantly to the variance of the total shear stress of the IS configurations and consider the origins of the anisotropy and spatial extent of the stress correlations.

Experiments on high efficiency aerosol filtration

International Nuclear Information System (INIS)

Mazzini, M.; Cuccuru, A.; Kunz, P.

1977-01-01

Research on high efficiency aerosol filtration by the Nuclear Engineering Institute of Pisa University and by CAMEN in collaboration with CNEN is outlined. HEPA filter efficiency was studied as a function of the type and size of the test aerosol, and as a function of flowrate (+-50% of the nominal value), air temperature (up to 70 0 C), relative humidity (up to 100%), and durability in a corrosive atmosphere (up to 140 hours in NaCl mist). In the selected experimental conditions these influences were appreciable but are not sufficient to be significant in industrial HEPA filter applications. Planned future research is outlined: measurement of the efficiency of two HEPA filters in series using a fixed particle size; dependence of the efficiency on air, temperatures up to 300-500 0 C; performance when subject to smoke from burning organic materials (natural rubber, neoprene, miscellaneous plastics). Such studies are relevant to possible accidental fires in a plutonium laboratory

Did Creatinine Standardization Give Benefits to the Evaluation of Glomerular Filtration Rate?

OpenAIRE

Piéroni, Laurence; Bargnoux, Anne-Sophie; Cristol, Jean-Paul; Cavalier, Etienne; Delanaye, Pierre

2017-01-01

During the last decade, a lot of efforts has been made to improve the evaluation of renal functions. Measured Glomerular Filtration Rate (GFR) remains the only valuable test to confirm or confute the status of chronic kidney disease (CKD) and is recommended by Kidney Disease Global Outcomes guidelines when estimation of GFR is not reliable. However, in routine clinical practice, serum creatinine remains the one of the most prescribed biological parameters and is an undeniable factor, alone or...

Toxic release consequence analysis tool (TORCAT) for inherently safer design plant

International Nuclear Information System (INIS)

Shariff, Azmi Mohd; Zaini, Dzulkarnain

2010-01-01

Many major accidents due to toxic release in the past have caused many fatalities such as the tragedy of MIC release in Bhopal, India (1984). One of the approaches is to use inherently safer design technique that utilizes inherent safety principle to eliminate or minimize accidents rather than to control the hazard. This technique is best implemented in preliminary design stage where the consequence of toxic release can be evaluated and necessary design improvements can be implemented to eliminate or minimize the accidents to as low as reasonably practicable (ALARP) without resorting to costly protective system. However, currently there is no commercial tool available that has such capability. This paper reports on the preliminary findings on the development of a prototype tool for consequence analysis and design improvement via inherent safety principle by utilizing an integrated process design simulator with toxic release consequence analysis model. The consequence analysis based on the worst-case scenarios during process flowsheeting stage were conducted as case studies. The preliminary finding shows that toxic release consequences analysis tool (TORCAT) has capability to eliminate or minimize the potential toxic release accidents by adopting the inherent safety principle early in preliminary design stage.

Comparison of acid ethanol extraction and acid gel filtration prior to IGF-I and IGF-II radioimmunoassays

International Nuclear Information System (INIS)

Bang, P.; Eriksson, U.; Wivall, I.-L.; Hall, K.; Sara, V.

1991-01-01

Insulin-like growth factor binding proteins interfere in the IGF-I and -II radioimmunoassays. In an attempt to overcome this problem, we have compared the use of truncated IGF-I, with reduced IGFBP affinity, and IGF-I as radioligands for IGF-I RIA measurements in serum separated by acid gel filtration or acid ethanol extraction followed by cryo-precipitation. With truncated IGF-I as radioligand the IGF-I measurements in acid gel filtrates and acid ethanol extracts were significantly correlated in healthy subjects (N=42, r=0.91, p<0.001) and in patients with acromegaly (N=10, r=0.85, p<0.01), GH deficiency (N=10, r=0.88, p<0.001) or Type I diabetes mellitus (N=10, r=0.90, p<0.001). In contrast, the IGF-I concentrations in acid ethanol extracts determined with IGF-I as radioligand did not correlate with those in acid gel filtrates using truncated IGF-I radioligand in patients with acromegaly (r=0.61, NS) or GH deficiency (r=0.46, NS). In the latter group the mean IGF-I concentrations measured in acid ethanol extracts were erroneously elevated by 112%. Low-affinity antibodies used for IGF-II RIA determinations failed to give reliable results in acid ethanol extracts from patients with Type I diabetes mellitus or GH deficiency. In conclusion, erroneously high IGF-I concentrations owing to binding of the radioligand to IGFBPs not completely removed by acid ethanol extraction can be avoided by the use of truncated IGF-I as radioligand. (author)

On some Filtration Procedure for Jump Markov Process Observed in White Gaussian Noise

OpenAIRE

Khas'minskii, Rafail Z.; Lazareva, Betty V.

1992-01-01

The importance of optimal filtration problem for Markov chain with two states observed in Gaussian white noise (GWN) for a lot of concrete technical problems is well known. The equation for a posterior probability $\\pi(t)$ of one of the states was obtained many years ago. The aim of this paper is to study a simple filtration method. It is shown that this simplified filtration is asymptotically efficient in some sense if the diffusion constant of the GWN goes to 0. Some advantages of this proc...

Progress on PRISM, an inherently safe, economic, and testable advanced liquid metal reactor

International Nuclear Information System (INIS)

Tippets, F.E.; Salerno, L.N.; Boardman, C.E.; Kwant, W.; Murata, R.E.; Snyder, C.R.

1987-01-01

This paper reports progress on the design of PRISM (Power Reactor Inherently Safe Module) under the DOE-sponsored innovative reactor program now in its third year at General Electric. The purpose of this program is to develop a design for an inherently safe, reliable, and marketable liquid metal fast reactor power plant. The PRISM design approach includes the following key elements: Compact sodium-cooled pool-type reactor modules that are sized to enable factory fabrication, economical shipment to inland as well as water-side sites, and economical full-scale prototype testing for design certification; Nuclear safety-related envelope limited to the reactor modules and their service systems; Inherent, passive shutdown heat removal for loss-of-cooling events; Inherent, passive reactivity shutdown for failure-to-scram events

Self Cleaning High Efficiency Particulate Air (HEPA) Filtration without Interrupting Process Flow - 59347

International Nuclear Information System (INIS)

Chadwick, Chris

2012-01-01

The strategy of protecting the traditional glass fibre HEPA filtration train from it's blinding contamination and the recovery of dust by the means of self cleaning, pre-filtration is a proven means in the reduction of ultimate disposal volumes and has been used within the Fuel Production Industry. However, there is an increasing demand in nuclear applications requiring elevated operating temperatures, fire resistance, moisture resistance and chemical composition that the existing glass fibre HEPA filtration cannot accommodate, which can be remedied by the use of a metallic HEPA filter media. Previous research suggests that the then costs to the Department of Energy (DOE), based on a five year life cycle, was $29.5 million for the installation, testing, removal and disposal of glass fibre HEPA filtration trains. Within these costs, $300 was the value given to the filter and $4, 450 was given to the peripheral activity. Development of a low cost, cleanable, metallic, direct replacement of the traditional filter train will the clear solution. The Bergman et al work has suggested that a 1000 ft 3 /min, cleanable, stainless HEPA could be commercially available for $5, 000 each, whereas the industry has determined that the truer cost of such an item in isolation would be closer to $15, 000. This results in a conflict within the requirement between 'low cost' and 'stainless HEPA'. By proposing a system that combines metallic HEPA filtration with the ability to self clean without interrupting the process flow, the need for a tradition HEPA filtration train will be eliminated and this dramatically reduces the resources required for cleaning or disposal, thus presenting a route to reducing ultimate costs. The paper will examine the performance characteristics, filtration efficiency, flow verses differential pressure and cleanability of a self cleaning HEPA grade sintered metal filter element, together with data to prove the contention. (authors)

Ultrasonic flow-through filtration of microparticles in a microfluidic channel using frequency sweep technique

International Nuclear Information System (INIS)

Seo, Dae Cheol; Ahn, Bong Young; Cho, Seung Hyun; Siddique, A. K. M. Ariful Haque; Kim, Cheol Gi

2013-01-01

Many studies have been conducted on the filtration of microparticles using the acoustic radiation force of ultrasonic standing wave. The present work concerns a flow-through particle filtration method by utilizing frequency varying ultrasound. The periodical frequency sweep of the ultrasonic standing wave translocates particles across a microchannel, where particles in fluid flow are filtrated without barriers. The present filtration technique in a microfluidic channel was proposed conceptually in the 1990s. However, its experimental realization on actual particles in a microfluidic channel has not been carried out in a notable way. Several sizes of polystyrene microspheres (10 µm to 90 µm) and silicon carbide (SiC) particles (37 µm) suspended in water were applied as a test sample. For filtration of those particles, a Y-branched microfluidic channel with one inlet and two outlets was made out of steel and acrylic as a form of modulized device. Ultrasound of a few MHz in band frequency (1.75 MHz to 3.05 MHz) was transmitted into one side of the channel wall to generate a standing wave field in fluid flow. The periodical frequency sweep operation showed successful filtration performance, whereby particles in water flowed into one outlet and purified water flowed into the other outlet of the Y branch of the channel.

Effect of high temperature filtration on out-core corrosion product activity

International Nuclear Information System (INIS)

Horvath, G.L.; Bogancs, J.

1983-01-01

Investigation of the effect of high temperature filtration on corrosion product transport and out-core corrosion product activity has been carried out for VVER-440 plants. In the physico-chemical model applied particulate and dissolved corrosion products were taken into account. We supposed 100% effectivity for the particulate filter. It was found that about 0,5% 160 t/h/ of the main flow would result in an approx.50% reduction of the out-core corrosion product activity. Investigation of the details of the physico-chemical model in Nuclear Power Plant Paks showed a particle deposition rate measured during power transients fairly agreeing with other measurements and data used in the calculations. (author)

Radio elements / bottom salts separation by nano-filtration aided by complexation in a highly saline environment

International Nuclear Information System (INIS)

Gaubert, Eric

1997-01-01

This research thesis addresses the use of a membrane-based technique, nano-filtration, aided or not by complexation, for the processing of highly saline liquid effluents produced by radio-chemical decontamination. The objective is to separate non-radioactive elements (sodium nitrate) from radio-elements (caesium, strontium and actinides) in order to reduce the volume of wastes. Within the perspective of an industrial application, a system to concentrate the effluent is firstly defined. Different nano-filtration membranes are tested and reveal to be insufficient in highly saline environment. A stage of selective complexation of radio-elements is therefore considered before nano-filtration. The main factors affecting performance of nano-filtration-complexation (for a given membrane system) are identified: ionic force, pH, ligand content, trans-membrane pressure. Finally, a nano-filtration pilot is implemented to perform nano-filtration-complexation operations by remote handling on radioactive substances [fr

Measurement of single-kidney glomerular filtration function from magnetic resonance perfusion renography

Energy Technology Data Exchange (ETDEWEB)

Zeng, Meiying; Cheng, Yingsheng [Department of Radiology, Shanghai Jiao Tong University Affiliated Sixth People' s Hospital, Shanghai 200233 (China); Zhao, Binghui, E-mail: binghuizhao@163.com [Department of Radiology, Shanghai Tenth People' s Hospital, Tongji University, Shanghai 200072 (China)

2015-08-15

Highlights: • MRPR monitors the transit of contrast material through nephron. • MRPR could reveal renal physiological characteristics in quality and quantity. • This review outlines the basics and future challenges of DCE MRPR. - Abstract: Glomerular filtration rate (GFR) describes the flow rate of filtered fluid through the kidney, and is considered to be the reference standard in the evaluation of renal function. There are many ways to test the GFR clinically, such as serum creatinine concentration, blood urea nitrogen and SPECT renography, however, they’re all not a good standard to evaluate the early damage of renal function. In recent years, the improvement of MRI hardware and software makes it possible to reveal physiological characteristics such as renal blood flow or GFR by dynamic contrast enhancement magnetic resonance perfusion renography (DEC MRPR). MRPR is a method used to monitor the transit of contrast material, typically a gadolinium chelate, through the renal cortex, the medulla, and the collecting system. This review outlines the basics of DCE MRPR included acquisition of dynamic MR perfusion imaging, calculation of the contrast concentration from signal intensity and compartment models, and some challenges of MRPR method faced in prospective clinical application.

Assessment of the microbial growth potential of slow sand filtrate with the biomass production potential test in comparison with the assimilable organic carbon method.

Science.gov (United States)

van der Kooij, Dick; Veenendaal, Harm R; van der Mark, Ed J; Dignum, Marco

2017-11-15

Slow sand filtration is the final treatment step at four surface-water supplies in the Netherlands. The microbial growth potential (MGP) of the finished water was measured with the assimilable organic carbon (AOC) method using pure cultures and the biomass production potential (BPP) test. In the BPP test, water samples were incubated untreated at 25 °C and the active-biomass concentration was measured by adenosine tri-phosphate (ATP) analysis. Addition of a river-water inoculum improved the test performance and characteristic growth and maintenance profiles of the water were obtained. The maximum ATP concentration attained within seven days and the cumulative biomass production after 14 days of incubation (BPC 14 , d ng ATP L -1 ) showed highly significant and strong linear relationships with the AOC in the slow sand filtrates. The lowest AOC and BPC 14 levels were observed in the supplies applying dune filtration without ozonation in post treatment, with AOC/TOC = 1.7 ± 0.3 μg acetate-C equivalents mg -1 C and BPC 14 /TOC = 16.3 ± 2.2 d ng ATP mg -1 C, corresponding with 1.2 ± 0.19 ng ATP mg -1 C. These characteristics may represent the lowest specific MGP of natural organic matter achievable by biofiltration at temperatures ≤20 °C. The AOC and BPC 14 concentrations in the slow sand filtrate of the supply treating lake water by ozonation with granular-activated-carbon filtration and slow sand filtration as post treatment increased with decreasing temperature. The BPP test revealed that this slow sand filtrate sampled at 2 °C contained growth-promoting compounds that were not detected with the AOC test. These observations demonstrate the utility of the BPP test for assessing the MGP of drinking water and show the performance limits of biofiltration for MGP reduction. Copyright © 2017 Elsevier Ltd. All rights reserved.

Antifungal Activity of Culture Filtrates and Organic Extracts of Aspergillus spp. against Pythium ultimum

OpenAIRE

Rania Aydi-Ben Abdallah; Marwa Hassine; Hayfa Jabnoun-Khiareddine; Rabiaa Haouala; Mejda Daami-Remadi

2014-01-01

Culture filtrates, chloroform and ethyl acetate extracts of nine isolates of Aspergillus spp. (A. niger, A. terreus, A. flavus and Aspergillus sp.), isolated from soil and compost, were tested for antifungal activity against Pythium ultimum the causal agent of the potato Pythium leak. Culture filtrates showed a significant antifungal activity at the different tested concentrations. Total inhibition of the pathogen was induced by the filtrate of CH8 of Aspergillus sp., used at 10% ...

EM Task 9 - Centrifugal Membrane Filtration

International Nuclear Information System (INIS)

Stevens, B.G.; Stepan, D.J.; Hetland, M.D.

1998-01-01

This project is designed to establish the utility of a novel centrifugal membrane filtration technology for the remediation of liquid mixed waste streams at US Department of Energy (DOE) facilities in support of the DOE Environmental Management (EM) program. The Energy and Environmental Research Center (EERC) has teamed with SpinTek Membrane Systems, Inc., a small business and owner of the novel centrifugal membrane filtration technology, to establish the applicability of the technology to DOE site remediation and the commercial viability of the technology for liquid mixed waste stream remediation. The technology is a uniquely configured process that makes use of ultrafiltration and centrifugal force to separate suspended and dissolved solids from liquid waste streams, producing a filtered water stream and a low-volume contaminated concentrate stream. This technology has the potential for effective and efficient waste volume minimization, the treatment of liquid tank wastes, the remediation of contaminated groundwater plumes, and the treatment of secondary liquid waste streams from other remediation processes, as well as the liquid waste stream generated during decontamination and decommissioning activities

Decline in measured glomerular filtration rate is associated with a decrease in endurance, strength, balance and fine motor skills.

Science.gov (United States)

Hellberg, Matthias; Höglund, Peter; Svensson, Philippa; Abdulahi, Huda; Clyne, Naomi

2017-07-01

Physical performance in chronic kidney disease affects morbidity and mortality. The aim was to find out which measures of physical performance are important in chronic kidney disease (CKD) and if there are associations with declining measured glomerular filtration rate (GFR). Endurance was assessed by 6 min walk test (6-MWT) and stair climbing, muscular endurance by 30 s sit to stand, heel rises and toe lifts, strength by quadriceps- and handgrip-strength, balance by functional reach and Berg's balance scale, and fine motor skills by Moberg's picking-up test. GFR was measured by Iohexol clearance. The study comprised 101 patients with CKD 3b-5 not started dialysis, 40 women and 61 men, with a mean age of 67 ± 13 (range: 22 - 87) years. All measures of physical performance were impaired. A decrease in GFR of 10 mL/min per 1.73 m 2 corresponded to a 35 metre shorter walking distance in the 6-MWT. Multivariable linear regression analysis showed significant relationships between decline in GFR and the 6-MWT (P = 0.04), isometric quadriceps strength left (P = 0.04), balance measured as functional reach (P = 0.02) and fine motor skills in the left hand as measured by Moberg's picking-up test (P = 0.01), respectively, after sex, age, comorbidity and the interaction between sex and age had been taken into account. Endurance, muscular endurance, strength, balance and fine motor skills were impaired in patients with CKD 3b-5. Walking capacity, isometric quadriceps strength, balance, and fine motor skills were associated with declining GFR. The left extremities were more susceptible to GFR, ageing and comorbidities and seem thus to be more sensitive. © 2016 Asian Pacific Society of Nephrology.

Stochastic modeling of filtrate alkalinity in water filtration devices: Transport through micro/nano porous clay based ceramic materials

Science.gov (United States)

Clay and plant materials such as wood are the raw materials used in manufacture of ceramic water filtration devices around the world. A step by step manufacturing procedure which includes initial mixing, molding and sintering is used. The manufactured ceramic filters have numerous pores which help i...

Formation of filtration fields close to near-surface radioactive waste storages

International Nuclear Information System (INIS)

Mart'yanov, V.V.

2008-01-01

Data on the formation of filtration fields in the location of near-surface radioactive waste storages for the conditions of uniformly isotropic properties of bearing strata are demonstrated. The possibility for changing parameters of mean-caused ground flow depending on water permeability of the storages and their dimensions in plan is noted. Comparison of different filtration fields permits to determine a state of its isolating properties. Assessment criteria of the storage engineering barriers integrity are given. Conditions for uniformly isotropic properties of bearing strata by three scenarios, when engineering barriers of the storage are waterproof, distracted or lost protective properties in full, have been determined. Changing filtration field, geochemical and radiochemical situations in bearing strata are noted to represent one of basic characteristics of the integrity of the storage [ru

Filtration of Oak Ridge National Laboratory simulated liquid low-level waste

International Nuclear Information System (INIS)

Fowler, V.L.; Hewitt, J.D.

1989-08-01

A method for disposal of Oak Ridge National Laboratory's (ORNL's) liquid low-level radioactive waste (LLLW) is being developed in which the material will be solidified in cement and stored in an aboveground engineered storage facility. The acceptability of the final waste form rests in part on the presence or absence of transuranic isotopes. Filtration methods to remove transuranic isotopes from the bulk liquid stored in the Melton Valley Storage Tanks (MVST) were investigated in this study. Initial batch studies using waste from MVST indicate that >99.9% of the transuranic isotopes can be removed from the bulk liquid by simple filtration. Bench-scale studies with a nonradioactive surrogate waste indicate that >99.5% of the suspended solids can be removed from the bulk liquid via inertial crossflow filtration. 4 refs., 3 figs., 11 tabs

Estimating filtration coefficients for straining from percolation and random walk theories

DEFF Research Database (Denmark)

Yuan, Hao; Shapiro, Alexander; You, Zhenjiang

2012-01-01

In this paper, laboratory challenge tests are carried out under unfavorable attachment conditions, so that size exclusion or straining is the only particle capture mechanism. The experimental results show that far above the percolation threshold the filtration coefficients are not proportional...... size exclusion theory or the model of parallel tubes with mixing chambers, where the filtration coefficients are proportional to the flux through smaller pores, and the predicted penetration depths are much lower. A special capture mechanism is proposed, which makes it possible to explain...... the experimentally observed power law dependencies of filtration coefficients and large penetration depths of particles. Such a capture mechanism is realized in a 2D pore network model with periodical boundaries with the random walk of particles on the percolation lattice. Geometries of infinite and finite clusters...

Inherent calibration of a blue LED-CE-DOAS instrument to measure iodine oxide, glyoxal, methyl glyoxal, nitrogen dioxide, water vapour and aerosol extinction in open cavity mode

Directory of Open Access Journals (Sweden)

R. Thalman

2010-12-01

Full Text Available The combination of Cavity Enhanced Absorption Spectroscopy (CEAS with broad-band light sources (e.g. Light-Emitting Diodes, LEDs lends itself to the application of cavity enhanced Differential Optical Absorption Spectroscopy (CE-DOAS to perform sensitive and selective point measurements of multiple trace gases and aerosol extinction with a single instrument. In contrast to other broad-band CEAS techniques, CE-DOAS relies only on the measurement of relative intensity changes, i.e. does not require knowledge of the light intensity in the absence of trace gases and aerosols (I₀. We have built a prototype LED-CE-DOAS instrument in the blue spectral range (420–490 nm to measure nitrogen dioxide (NO₂, glyoxal (CHOCHO, methyl glyoxal (CH₃COCHO, iodine oxide (IO, water vapour (H₂O and oxygen dimers (O₄. We demonstrate the first direct detection of methyl glyoxal, and the first CE-DOAS detection of CHOCHO and IO. The instrument is further inherently calibrated for light extinction from the cavity by observing O₄ or H₂O (at 477 nm and 443 nm and measuring the pressure, relative humidity and temperature independently. This approach is demonstrated by experiments where laboratory aerosols of known size and refractive index were generated and their extinction measured. The measured extinctions were then compared to the theoretical extinctions calculated using Mie theory (3–7 × 10⁻⁷cm⁻¹. Excellent agreement is found from both the O₄ and H₂O retrievals. This enables the first inherently calibrated CEAS measurement at blue wavelengths in open cavity mode, and eliminates the need for sampling lines to supply air to the cavity, i.e., keep the cavity enclosed and/or aerosol free. Measurements in open cavity mode are demonstrated for CHOCHO, CH₃COCHO, NO₂, H₂O and aerosol extinction. Our prototype

Effect of the angle of apical resection on apical leakage, measured with a computerized fluid filtration device.

Science.gov (United States)

Garip, Hasan; Garip, Yıldız; Oruçoğlu, Hasan; Hatipoğlu, Seda

2011-03-01

We determined the effect of the angle of apical resection on apical leakage using a computerized fluid filtration meter with a laser system and a digital air pressure regulator in 46 extracted single-rooted human teeth. Orthograde endodontic treatment was performed. The root canals were prepared up to a size 50 K-type file with 17% EDTA solution (Roth International, Chicago, IL) and 5% NaOCl solution as the irrigant. Gates Glidden burs (Maillefer Instruments, Ballaigues, Switzerland) were used to flare the coronal two thirds of the canal. All canals were dried with paper points and then obturated using cold lateral condensation (except for the positive controls) of gutta-percha points and AH plus (Dentsply DeTrey, Konstanz, Germany). All 40 roots were sectioned 3 mm from the apex. Forty teeth were assigned randomly into 1 of 4 experimental groups of 10 teeth each: in group 1, the teeth were resected apically (90° angle) and the cavities were obturated with mineral trioxide aggregate (MTA); in group 2, after apical resection (90° angle), a root-end cavity was prepared using ultrasonic diamond retrotips and the cavities were obturated with MTA; in group 3, the teeth were resected apically (∼45° angle) and the cavities were obturated with MTA; and in group 4, after apical resection (∼45° angle), a root-end cavity was prepared using ultrasonic diamond retrotips and the cavities were obturated with MTA. An additional 6 teeth were used as controls (3 each, negative and positive controls). Apical leakage was measured using a computerized fluid filtration meter with a laser system. The mean apical microleakage was 2.0 ± 0.4 × 10(-4), 1.6 ± 0.6 × 10(-4), 1.6 ± 0.9 × 10(-4), and 1.8 ± 0.7 × 10(-4) μL/cmH(2)O/min(-1) at 1.2 atm, in groups 1 to 4, respectively. Although the mean apical microleakage was greater in group 1, the differences among the 4 groups were not statistically significant (P > .05). The results of these in vitro studies showed that when an

Filtration of engineered nanoparticles using porous membranes

NARCIS (Netherlands)

Trzaskus, Krzystof

2016-01-01

The research presented in this thesis aims at providing a better understanding of the fundamental aspects responsible for nanoparticle removal and fouling development during filtration of engineered nanoparticles. The emphasis is put on the role of interparticle interactions in the feed solution,

Organic micropollutant removal during river bank filtration

NARCIS (Netherlands)

Bertelkamp, C.

2015-01-01

This study investigated the factors influencing the main removal mechanisms (adsorption and biodegradation) for organic micropollutant (OMP) removal during river bank filtration (RBF) and the possibility of developing a predictive model of this process for OMP removal during RBF. Chapter 2 analysed

77 FR 38857 - Design, Inspection, and Testing Criteria for Air Filtration and Adsorption Units of Normal...

Science.gov (United States)

2012-06-29

... Filtration and Adsorption Units of Normal Atmosphere Cleanup Systems in Light-Water- Cooled Nuclear Power... Criteria for Air Filtration and Adsorption Units of Normal Atmosphere Cleanup Systems in Light-Water-Cooled... draft regulatory guide (DG), DG-1280, ``Design, Inspection, and Testing Criteria for Air Filtration and...

Memory accessibility shapes explanation: Testing key claims of the inherence heuristic account.

Science.gov (United States)

Hussak, Larisa J; Cimpian, Andrei

2018-01-01

People understand the world by constructing explanations for what they observe. It is thus important to identify the cognitive processes underlying these judgments. According to a recent proposal, everyday explanations are often constructed heuristically: Because people need to generate explanations on a moment-by-moment basis, they cannot perform an exhaustive search through the space of possible reasons, but may instead use the information that is most easily accessible in memory (Cimpian & Salomon 2014a, b). In the present research, we tested two key claims of this proposal that have so far not been investigated. First, we tested whether-as previously hypothesized-the information about an entity that is most accessible in memory tends to consist of inherent or intrinsic facts about that entity, rather than extrinsic (contextual, historical, etc.) facts about it (Studies 1 and 2). Second, we tested the implications of this difference in the memory accessibility of inherent versus extrinsic facts for the process of generating explanations: Does the fact that inherent facts are more accessible than relevant extrinsic facts give rise to an inherence bias in the content of the explanations generated (Studies 3 and 4)? The findings supported the proposal that everyday explanations are generated in part via a heuristic process that relies on easily accessible-and often inherent-information from memory.

Is the inherent potential of maize roots efficient for soil phosphorus acquisition?

Directory of Open Access Journals (Sweden)

Yan Deng

Full Text Available Sustainable agriculture requires improved phosphorus (P management to reduce the overreliance on P fertilization. Despite intensive research of root adaptive mechanisms for improving P acquisition, the inherent potential of roots for efficient P acquisition remains unfulfilled, especially in intensive agriculture, while current P management generally focuses on agronomic and environmental concerns. Here, we investigated how levels of soil P affect the inherent potential of maize (Zea mays L. roots to obtain P from soil. Responses of root morphology, arbuscular mycorrhizal colonization, and phosphate transporters were characterized and related to agronomic traits in pot and field experiments with soil P supply from deficiency to excess. Critical soil Olsen-P level for maize growth approximated 3.2 mg kg(-1, and the threshold indicating a significant environmental risk was about 15 mg kg(-1, which represented the lower and upper levels of soil P recommended in current P management. However, most root adaptations involved with P acquisition were triggered when soil Olsen-P was below 10 mg kg(-1, indicating a threshold for maximum root inherent potential. Therefore, to maintain efficient inherent potential of roots for P acquisition, we suggest that the target upper level of soil P in intensive agriculture should be reduced from the environmental risk threshold to the point maximizing the inherent potential of roots.

Is the inherent potential of maize roots efficient for soil phosphorus acquisition?

Science.gov (United States)

Deng, Yan; Chen, Keru; Teng, Wan; Zhan, Ai; Tong, Yiping; Feng, Gu; Cui, Zhenling; Zhang, Fusuo; Chen, Xinping

2014-01-01

Sustainable agriculture requires improved phosphorus (P) management to reduce the overreliance on P fertilization. Despite intensive research of root adaptive mechanisms for improving P acquisition, the inherent potential of roots for efficient P acquisition remains unfulfilled, especially in intensive agriculture, while current P management generally focuses on agronomic and environmental concerns. Here, we investigated how levels of soil P affect the inherent potential of maize (Zea mays L.) roots to obtain P from soil. Responses of root morphology, arbuscular mycorrhizal colonization, and phosphate transporters were characterized and related to agronomic traits in pot and field experiments with soil P supply from deficiency to excess. Critical soil Olsen-P level for maize growth approximated 3.2 mg kg(-1), and the threshold indicating a significant environmental risk was about 15 mg kg(-1), which represented the lower and upper levels of soil P recommended in current P management. However, most root adaptations involved with P acquisition were triggered when soil Olsen-P was below 10 mg kg(-1), indicating a threshold for maximum root inherent potential. Therefore, to maintain efficient inherent potential of roots for P acquisition, we suggest that the target upper level of soil P in intensive agriculture should be reduced from the environmental risk threshold to the point maximizing the inherent potential of roots.

Uncertainty and Sensitivity Analysis of Filtration Models for Non-Fickian transport and Hyperexponential deposition

DEFF Research Database (Denmark)

Yuan, Hao; Sin, Gürkan

2011-01-01

Uncertainty and sensitivity analyses are carried out to investigate the predictive accuracy of the filtration models for describing non-Fickian transport and hyperexponential deposition. Five different modeling approaches, involving the elliptic equation with different types of distributed...... filtration coefficients and the CTRW equation expressed in Laplace space, are selected to simulate eight experiments. These experiments involve both porous media and colloid-medium interactions of different heterogeneity degrees. The uncertainty of elliptic equation predictions with distributed filtration...... coefficients is larger than that with a single filtration coefficient. The uncertainties of model predictions from the elliptic equation and CTRW equation in Laplace space are minimal for solute transport. Higher uncertainties of parameter estimation and model outputs are observed in the cases with the porous...

Is human fracture hematoma inherently angiogenic?

LENUS (Irish Health Repository)

Street, J

2012-02-03

This study attempts to explain the cellular events characterizing the changes seen in the medullary callus adjacent to the interfragmentary hematoma during the early stages of fracture healing. It also shows that human fracture hematoma contains the angiogenic cytokine vascular endothelial growth factor and has the inherent capability to induce angiogenesis and thus promote revascularization during bone repair. Patients undergoing emergency surgery for isolated bony injury were studied. Raised circulating levels of vascular endothelial growth factor were seen in all injured patients, whereas the fracture hematoma contained significantly higher levels of vascular endothelial growth factor than did plasma from these injured patients. However, incubation of endothelial cells in fracture hematoma supernatant significantly inhibited the in vitro angiogenic parameters of endothelial cell proliferation and microtubule formation. These phenomena are dependent on a local biochemical milieu that does not support cytokinesis. The hematoma potassium concentration is cytotoxic to endothelial cells and osteoblasts. Subcutaneous transplantation of the fracture hematoma into a murine wound model resulted in new blood vessel formation after hematoma resorption. This angiogenic effect is mediated by the significant concentrations of vascular endothelial growth factor found in the hematoma. This study identifies an angiogenic cytokine involved in human fracture healing and shows that fracture hematoma is inherently angiogenic. The differences between the in vitro and in vivo findings may explain the phenomenon of interfragmentary hematoma organization and resorption that precedes fracture revascularization.

Polymer-treated woody biomass: a filtration medium for removing phosphate from water

Science.gov (United States)

Thomas L Eberhardt

2006-01-01

A two-stage treatment of refined aspen wood fiber with solutions of carboxymethyl cellulose (CMC) and ferrous chloride afforded a filtration medium that was effective in removing phosphate from test solutions. To assess the stability of the filtration medium, samples exposed to the test solutions were analyzed by FTIR spectroscopy. The resultant spectra indicated that...

Microwave-Irradiation-Assisted HVAC Filtration for Inactivation of Viral Aerosols (Postprint)

Science.gov (United States)

2012-02-01

Baggiani, A. and Senesi, S. (2004). Effect of Microwave Radiation on Bacillus subtilis Spores . J. Appl. Microbiol. 97: 1220–1227. Damit, B., Lee, C.N...AFRL-RX-TY-TP-2012-0020 MICROWAVE-IRRADIATION-ASSISTED HVAC FILTRATION FOR INACTIVATION OF VIRAL AEROSOLS POSTPRINT Myung-Heui Woo and...12-APR-2011 -- 11-DEC-2011 Microwave Irradiation-Assisted HVAC Filtration for Inactivation of Viral Aerosols (POSTPRINT) FA8650-06-C-5913 0602102F

Longitudinal-transverse liquid filtration in an annular heat-liberating medium

International Nuclear Information System (INIS)

Akhramovich, A.P.; Kolos, V.P.; Sorokin, V.N.

1987-01-01

The authors interpret experimental flow visualization data and construct a flow model for coolant filtration and flow in a layered granular heat exchange material for implementation in a reactor cooling system. Breakaway flow zones close to the ends of a layer in longitudinal-transverse liquid filtration are observed. In a linear approximation the problem of determining the form of the ends of the layer for which there is no flow breakaway is solved. The model is tested against experimental data for water and a nitrogen tetroxide coolant

Chiral filtration-induced spin/valley polarization in silicene line defects

Science.gov (United States)

Ren, Chongdan; Zhou, Benhu; Sun, Minglei; Wang, Sake; Li, Yunfang; Tian, Hongyu; Lu, Weitao

2018-06-01

The spin/valley polarization in silicene with extended line defects is investigated according to the chiral filtration mechanism. It is shown that the inner-built quantum Hall pseudo-edge states with identical chirality can serve as a chiral filter with a weak magnetic field and that the transmission process is restrained/strengthened for chiral states with reversed/identical chirality. With two parallel line defects, which act as natural chiral filtration, the filter effect is greatly enhanced, and 100% spin/valley polarization can be achieved.

Simulation of impaction filtration of aerosol droplets in porous media

OpenAIRE

Ghazaryan, L.; Lopez Penha, D.J.; Geurts, Bernardus J.; Stolz, S.; Stolz, Steffen; Winkelmann, Christoph; Pereira, J.C.F; Sequeira, A.; Pereira, J.M.C.

2010-01-01

We report on the development of a method to simulate from first principles the particle filtration efficiency of filters that are composed of structured porous media. We assume that the ratio of particle density to the fluid density is high. We concentrate on the motion of the particles in a laminar flow and quantify the role of inertial effects on the filtration of an ensemble of particles. We adopt the Euler-Lagrange approach, distinguishing a flow field in which the motion of a large numbe...

Quantification of the inherent uncertainty in the relaxation modulus and creep compliance of asphalt mixes

Science.gov (United States)

Kassem, Hussein A.; Chehab, Ghassan R.; Najjar, Shadi S.

2017-08-01

Advanced material characterization of asphalt concrete is essential for realistic and accurate performance prediction of flexible pavements. However, such characterization requires rigorous testing regimes that involve mechanical testing of a large number of laboratory samples at various conditions and set-ups. Advanced measurement instrumentation in addition to meticulous and accurate data analysis and analytical representation are also of high importance. Such steps as well as the heterogeneous nature of asphalt concrete (AC) constitute major factors of inherent variability. Thus, it is imperative to model and quantify the variability of the needed asphalt material's properties, mainly the linear viscoelastic response functions such as: relaxation modulus, E(t), and creep compliance, D(t). The objective of this paper is to characterize the inherent uncertainty of both E(t) and D(t) over the time domain of their master curves. This is achieved through a probabilistic framework using Monte Carlo simulations and First Order approximations, utilizing E^{*} data for six AC mixes with at least eight replicates per mix. The study shows that the inherent variability, presented by the coefficient of variation (COV), in E(t) and D(t) is low at small reduced times, and increases with the increase in reduced time. At small reduced times, the COV in E(t) and D(t) are similar in magnitude; however, differences become significant at large reduced times. Additionally, the probability distributions and COVs of E(t) and D(t) are mix dependent. Finally, a case study is considered in which the inherent uncertainty in D(t) is forward propagated to assess the effect of variability on the predicted number of cycles to fatigue failure of an asphalt mix.

On the maximum entropy distributions of inherently positive nuclear data

Energy Technology Data Exchange (ETDEWEB)

Taavitsainen, A., E-mail: aapo.taavitsainen@gmail.com; Vanhanen, R.

2017-05-11

The multivariate log-normal distribution is used by many authors and statistical uncertainty propagation programs for inherently positive quantities. Sometimes it is claimed that the log-normal distribution results from the maximum entropy principle, if only means, covariances and inherent positiveness of quantities are known or assumed to be known. In this article we show that this is not true. Assuming a constant prior distribution, the maximum entropy distribution is in fact a truncated multivariate normal distribution – whenever it exists. However, its practical application to multidimensional cases is hindered by lack of a method to compute its location and scale parameters from means and covariances. Therefore, regardless of its theoretical disadvantage, use of other distributions seems to be a practical necessity. - Highlights: • Statistical uncertainty propagation requires a sampling distribution. • The objective distribution of inherently positive quantities is determined. • The objectivity is based on the maximum entropy principle. • The maximum entropy distribution is the truncated normal distribution. • Applicability of log-normal or normal distribution approximation is limited.

Investigation of Microgranular Adsorptive Filtration System

Science.gov (United States)

Cai, Zhenxiao

Over the past few decades, enormous advances have been made in the application of low-pressure membrane filtration to both drinking water and wastewater treatment. Nevertheless, the full potential of this technology has not been reached, due primarily to limitations imposed by membrane fouling. In drinking water treatment, much of the fouling is caused by soluble and particulate natural organic matter (NOM). Efforts to overcome the problem have focused on removal of NOM from the feed solution, usually by addition of conventional coagulants like alum and ferric chloride (FeCl3) or adsorbents like powdered activated carbon (PAC). While coagulants and adsorbents can remove a portion of the NOM, their performance with respect to fouling control has been inconsistent, often reducing fouling but sometimes having no effect or even exacerbating fouling. This research investigated microgranular adsorptive filtration (muGAF), a process that combines three existing technologies---granular media filtration, packed bed adsorption, and membrane filtration---in a novel way to reduce membrane fouling while simultaneously removing NOM from water. In this technology, a thin layer of micron-sized adsorbent particles is deposited on the membrane prior to delivering the feed to the system. The research reported here represents the first systematic study of muGAF, and the results demonstrate the promising potential of this process. A new, aluminum-oxide-based adsorbent---heated aluminum oxide particles (HAOPs)---was synthesized and shown to be very effective for NOM removal as well as fouling reduction in muGAF systems. muGAF has also been demonstrated to work well with powdered activated carbon (PAC) as the adsorbent, but not as well as when HAOPs are used; the process has also been successful when used with several different membrane types and configurations. Experiments using a wide range of operational parameters and several analytical tools lead to the conclusion that the fouling

Filtration behavior of organic substance through a compacted bentonite

International Nuclear Information System (INIS)

Kanaji, Mariko; Kuno, Yoshio; Yui, Mikazu

1999-07-01

Filtration behavior of organic substance through a compacted bentonite was investigated. Na-type bentonite containing 30wt% of quartz sand was compacted in a column and the dry density was adjusted to be 1.6 g/cm 3 . Polyacrylic acid solution (including three types of polyacrylic acid, average molecular weight 2,100, 15,000 and 450,000) was prepared and was passed through the compacted bentonite. Molecular weight distributions of polyacrylic acid in the effluent solution were analysed by GPC (Gel Permeation Chromatography). A batch type experiment was also carried out in order to examine a sorption behavior of these organic substances onto the surfaces of grains of the bentonite. The results indicated that the smaller size polyacrylic acid (molecular weight < 100,000) was passed through the compacted bentonite. On the other hand, the larger size polyacrylic acid (molecular weight ≥100,000) was mostly filtrated by the compacted bentonite. The batch type sorption tests clarified that the polyacrylic acid did not sorb onto the surfaces of minerals constituting the bentonite. Therefore it was suggested that the larger size molecules (≥100,000) of organic substances could be predominantly filtrated by the microstructure of the compacted bentonite. (author)

Multiformity of inherent randomicity and visitation density in n symbolic dynamics

International Nuclear Information System (INIS)

Zhang Yagang; Wang Changjiang

2007-01-01

The multiformity of inherent randomicity and visitation density in n symbolic dynamics will be clarified in this paper. These stochastic symbolic sequences bear three features. The distribution of frequency, inter-occurrence times and the alignment of two random sequences are amplified in detail. The features of visitation density in surjective maps presents catholicity and the catholicity in n letters randomicity has the same measure foundation. We hope to offer a symbolic platform that satisfies these stochastic properties and to attempt to study certain properties of DNA base sequences, 20 amino acids symbolic sequences of proteid structure, and the time series that can be symbolic in finance market et al

Public health protection through bank filtration - Kearney Nebraska case study

Science.gov (United States)

Esseks, E.; Bellamy, W.; Heinemann, T.; Stocker, K.

2003-04-01

The investigation of Kearney's bank filtration system provides further evidence of this technology's capability to assist in providing public health protection, as it relates to drinking water. The results of hydrogeologic and treatment studies demonstrate the capabilities of the Platte River aquifer materials, in this locale, to remove pathogens and their surrogates. Continual monitoring and evaluations will establish the system’s longevity and continued treatment efficacy. The City of Kearney is located in south central Nebraska. The City owns and operates a public water system that serves approximately 24,889 people. The water system includes 12 wells located on Killgore Island in the Platte River. In 1994, the Nebraska Department of Health and Human Services System (Department) determined that 3 wells in the wellfield serving the City of Kearney were ground water under the direct influence of surface water. This determination was based on results of microscopic particulate analysis (MPA). The City of Kearney undertook the natural bank filtration study to determine whether natural bank filtration was occurring at the site and if the filtration was sufficient to meet pathogen treatment requirements designed to protect public health. A preliminary study was undertaken from June through October 1995. This coincided with the City’s peak pumping time, which may be the time when the influence of the River is greatest on the wellfield wells. Hydrogeologic studies assisted in selecting wells that were at highest risk based on shortest travel times and greatest differential head. Data collected included particle counts, MPAs, turbidity, coliform, centrifugate pellet evaluation (CPE) volumes, pH, conductivity, and temperature. Following analysis of data collected during the preliminary 18-week study the Department granted conditional approval of 2-log credit for removal of Giardia lamblia and 1-log credit for removal of viruses through bank filtration, pending the

Biophysical analysis of water filtration phenomenon in the roots of halophytes

Science.gov (United States)

Kim, Kiwoong; Lee, Sang Joon

2015-11-01

The water management systems of plants, such as water collection and water filtration have been optimized through a long history. In this point of view, new bio-inspired technologies can be developed by mimicking the nature's strategies for the survival of the fittest. In this study, the biophysical characteristics of water filtration process in the roots of halophytes are experimentally investigated in the plant hydrodynamic point of view. To understand the functional features of the halophytes 3D morphological structure of their roots are analyzed using advanced bioimaging techniques. The surface properties of the roots of halophytes are also examined Based on the quantitatively analyzed information, water filtration phenomenon in the roots is examined. Sodium treated mangroves are soaked in sodium acting fluorescent dye solution to trace sodium ions in the roots. In addition, in vitroexperiment is carried out by using the roots. As a result, the outermost layer of the roots filters out continuously most of sodium ions. This study on developing halophytes would be helpful for understanding the water filtration mechanism of the roots of halophytes and developing a new bio inspired desalination system. This research was financially supported by the National Research Foundation (NRF) of Korea (Contract grant number: 2008-0061991).

Polymer aids for settling and filtration of oil sands tailings

Energy Technology Data Exchange (ETDEWEB)

Wang, X. [Alberta Univ., Edmonton, AB (Canada). Dept. of Chemical and Materials Engineering; Energy Resources Conservation Board, Calgary, AB (Canada). Oil Sands Section; Xu, Z.; Masliyah, J.H. [Alberta Univ., Edmonton, AB (Canada). Dept. of Chemical and Materials Engineering

2008-07-01

Oil sand tailings are segregated into coarse and fine tailings. High volumes of toxic fluids and tailings are created in the process. Tailings ponds are an environmental risk with high operating and maintenance costs. Current commercial technologies uses chemical additions to create recycled water and composite tailings (CT). Researchers are now investigating centrifuged and dry mature fine tailings (MFT). Filtration processes with flocculants are used to separate the tailings into warm recycle water and dried cakes that can be used in reclamation processes. Studies are being conducted to find a polymer than can effectively flocculate and filter whole oil sands tailings. The filtration procedure uses pressure to produce released water. Polymers include magnafloc and Al-PAM polymer concentrations are used in slurry masses. Tests have been conducted to determine the settling rates of the polymers. The tests showed that Al-PAM filtered the tailings effectively. Paraffinic froth treatment tests have also been conducted to determine settling rates. A cake produced with froth treatment tailings of Al-PAM 400 ppm had a water content 42.5 wt per cent. The tests showed that while Magnafloc 1011 is a good settling aid, but a poor filtration addition. Al-PAM aided in both the flocculation and filtration processes. Higher Al-PAM dosages are needed for froth treatment tailings processes. It was concluded that dry cakes are produced with the addition of Al-PAM. tabs., figs.

Tactical supply chain planning models with inherent flexibility

DEFF Research Database (Denmark)

Esmaeilikia, Masoud; Fahimnia, Behnam; Sarkis, Joeseph

2016-01-01

Supply chains (SCs) can be managed at many levels. The use of tactical SC planning models with multiple flexibility options can help manage the usual operations efficiently and effectively, whilst improve the SC resiliency in response to inherent environmental uncertainties. This paper defines ta...

Hot filtration 2

International Nuclear Information System (INIS)

Jimenez Rebagliati, Raul; Liberman, S.J.

1982-01-01

The magnetic filtration technique allows the removal of suspended magnetic species from a fluid at high flow rate and temperature. It is specially advantageous for water purification in systems such as thermonuclear and thermoelectric plants in which corrosion products must be removed from the heat transport and cooling circuits. Using diluted aqueous suspensions of magnetite, the behaviour of a ball matrix filter was studied as a function of flow rate, temperature and concentration of particles. The retention efficiency shows an exponential decay with fluid's velocity and viscosity in agreement with theory. Within the range of concentration considered, there is no change in the retention with concentration. Design parameters for filters according to plant's needs are obtained from the results of this study. (Author) [es

Removal of heavy metals and radionuclides by seeded magnetic filtration

International Nuclear Information System (INIS)

Bibler, J.P.; Norrell, G.; Hemmings, R.L.; Bradbury, D.; Dunn, M.J.; Kalinauskas, G.L.

1991-01-01

Removal of traces of heavy metal or radionuclide contamination from solution at high flow rate presents a considerable technical challenge. Low flow methods of treatment such as particle gravity settling require expensive large volume equipment, whereas traditional methods of filtration can cause significant energy costs. Magnetic filtration can be used to provide a low cost method of solid-liquid separation at high flow rate, provided contaminants can be selectively bound to a magnetic solid particle. This paper describes the use of such selective magnetic particles made up of inorganic particles coupled with organic polymers

Resolution of the three dimensional structure of components of the glomerular filtration barrier

DEFF Research Database (Denmark)

Arkill, Kenton P; Qvortrup, Klaus; Starborg, Tobias

2014-01-01

The human glomerulus is the primary filtration unit of the kidney, and contains the Glomerular Filtration Barrier (GFB). The GFB had been thought to comprise 3 layers - the endothelium, the basement membrane and the podocyte foot processes. However, recent studies have suggested that at least two...

Filtration aids in uranium ore processing

International Nuclear Information System (INIS)

Ford, H.L.; Levine, N.M.; Risdon, A.R.

1975-01-01

A process of improving the filtration efficiency and separation of uranium ore pulps obtained by carbonate leaching of uranium ore which comprises treating said ore pulps with an aqueous solution of hydroxyalkyl guar selected from the group consisting of hydroxyethyl and hydroxypropyl guar in the amount of 0.1 and 2.0 pounds of hydroxyalkyl guar per ton of uranium ore

Influence of Iatrogenic Gaps, Cement Type, and Time on Microleakage of Cast Posts Using Spectrophotometer and Glucose Filtration Measurements.

Science.gov (United States)

Al-Madi, Ebtissam M; Al-Saleh, Samar A; Al-Khudairy, Reem I; Aba-Hussein, Taibah W

2018-04-06

To determine the influence of iatrogenic gaps, type of cement, and time on microleakage of cast posts using spectrophotometer and glucose filtration measurements. Forty-eight single-rooted teeth were divided into eight groups of six teeth each. Teeth were instrumented and obturated, and a cast post was fabricated. In addition to two control groups (positive and negative), a total of six groups were prepared: In four groups, an artificial 2- to 3-mm gap was created between post and residual gutta percha (GP), and two groups were prepared with intimate contact between post and residual GP. Posts were cemented with either zinc phosphate cement or resin cement. Leakage through the post after 1, 8, 14, and 20 days was measured using a glucose penetration model with two different reading methods. Mixed analysis of variance tests were performed to analyze the data. The presence of a gap between the apical end of the post and the most coronal portion of the GP remaining in the root canal after post space preparation increased microleakage significantly. However, microleakage was significantly less when the gap was refilled with GP compared to no gap. There was no difference in leakage between luting cements used. It was concluded that none of the cements were able to prevent microleakage. However, the addition of GP to residual GP did increase the sealing ability.

Inherent Limitations in Mid-Wave and Long-Wave-IR Upconversion Detector

DEFF Research Database (Denmark)

Barh, Ajanta; Tseng, Yu-Pei; Pedersen, Christian

2017-01-01

Inherent limitations in terms of optical losses, selection of nonlinear crystal(s), detection efficiency and pumping conditions in mid-wave (3-5 µm) and long-wave (8-12 µm) infrared frequency upconversion modules are investigated in this paper.......Inherent limitations in terms of optical losses, selection of nonlinear crystal(s), detection efficiency and pumping conditions in mid-wave (3-5 µm) and long-wave (8-12 µm) infrared frequency upconversion modules are investigated in this paper....

Enlargement of filtration with finance in view

CERN Document Server

Aksamit, Anna

2017-01-01

This volume presents classical results of the theory of enlargement of filtration. The focus is on the behavior of martingales with respect to the enlarged filtration and related objects. The study is conducted in various contexts including immersion, progressive enlargement with a random time and initial enlargement with a random variable.  The aim of this book is to collect the main mathematical results (with proofs) previously spread among numerous papers, great part of which is only available in French. Many examples and applications to finance, in particular to credit risk modelling and the study of asymmetric information, are provided to illustrate the theory. A detailed summary of further connections and applications is given in bibliographic notes which enables to deepen study of the topic.  This book fills a gap in the literature and serves as a guide for graduate students and researchers interested in the role of information in financial mathematics and in econometric science. A basic knowledge of...

Surgical outcomes of the Ex-PRESS glaucoma filtration device in African American and white glaucoma patients

Directory of Open Access Journals (Sweden)

Salim S

2012-06-01

Full Text Available Sarwat Salim, Haiming Du, Sumalee Boonyaleephan, Jim WanUniversity of Tennessee Health Science Center, Memphis, TN, USAPurpose: To compare the surgical outcomes of the Ex-PRESS glaucoma filtration device in African American and white glaucoma patients.Design: Retrospective comparative case series.Methods: This was a comparative case series of 36 eyes of 36 African Americans and 43 eyes of 43 whites that underwent placement of the Ex-PRESS glaucoma filtration device under a partial-thickness scleral flap for uncontrolled glaucoma. All eyes received intraoperative mitomycin C. The primary outcome measures were intraocular pressure (IOP, number of postoperative glaucoma medications, and surgical success. Surgical success was defined as IOP between 5 and 18 mm Hg, with or without glaucoma medications, without further glaucoma surgery, or loss of light perception vision. Results: Average follow-up was 31.9 ± 9.8 (range, 14.6–47 months for African Americans and 30.7 ± 8.6 (range, 14.3–47 months for whites. At 33 months, surgical success was 80.0% in the African American group and 83.3% in the white group (P = 1.00. Reasons for surgical failure included increased IOP (3 eyes, 3.8%, persistent hypotony with maculopathy (1 eye, 1.3%, and further surgery (4 eyes, 5.06%. Compared with preoperative values, the mean postoperative IOP and number of glaucoma medications were significantly reduced in both groups, and no statistical difference was observed between the two groups at 33 months. Postoperative complications were similar in the two groups.Conclusions: Similar surgical outcomes were observed in African American and white glaucoma patients after implantation of the Ex-PRESS glaucoma filtration device. This latest modification of glaucoma filtration surgery may be a better surgical option for African Americans given its potential advantages of no tissue removal, predictable outcomes related to consistent lumen size and controlled flow, fewer

DUST FILTRATION BY PLANET-INDUCED GAP EDGES: IMPLICATIONS FOR TRANSITIONAL DISKS

Energy Technology Data Exchange (ETDEWEB)

Zhu Zhaohuan; Dong Ruobing [Department of Astrophysical Sciences, 4 Ivy Lane, Peyton Hall, Princeton University, Princeton, NJ 08544 (United States); Nelson, Richard P. [Astronomy Unit, Queen Mary University of London, Mile End Road, London E1 4NS (United Kingdom); Espaillat, Catherine [Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Hartmann, Lee, E-mail: zhzhu@astro.princeton.edu, E-mail: rdong@astro.princeton.edu, E-mail: lhartm@umich.edu, E-mail: r.p.nelson@qmul.ac.uk, E-mail: cespaillat@cfa.harvard.edu [Department of Astronomy, University of Michigan, 500 Church St., Ann Arbor, MI 48109 (United States)

2012-08-10

By carrying out two-dimensional two-fluid global simulations, we have studied the response of dust to gap formation by a single planet in the gaseous component of a protoplanetary disk-the so-called dust filtration mechanism. We have found that a gap opened by a giant planet at 20 AU in an {alpha} = 0.01, M-dot =10{sup -8} M{sub Sun} yr{sup -1} disk can effectively stop dust particles larger than 0.1 mm drifting inward, leaving a submillimeter (submm) dust cavity/hole. However, smaller particles are difficult to filter by a gap induced by a several M{sub J} planet due to (1) dust diffusion and (2) a high gas accretion velocity at the gap edge. Based on these simulations, an analytic model is derived to understand what size particles can be filtered by the planet-induced gap edge. We show that a dimensionless parameter T{sub s} /{alpha}, which is the ratio between the dimensionless dust stopping time and the disk viscosity parameter, is important for the dust filtration process. Finally, with our updated understanding of dust filtration, we have computed Monte Carlo radiative transfer models with variable dust size distributions to generate the spectral energy distributions of disks with gaps. By comparing with transitional disk observations (e.g., GM Aur), we have found that dust filtration alone has difficulties depleting small particles sufficiently to explain the near-IR deficit of moderate M-dot transitional disks, except under some extreme circumstances. The scenario of gap opening by multiple planets studied previously suffers the same difficulty. One possible solution is to invoke both dust filtration and dust growth in the inner disk. In this scenario, a planet-induced gap filters large dust particles in the disk, and the remaining small dust particles passing to the inner disk can grow efficiently without replenishment from fragmentation of large grains. Predictions for ALMA have also been made based on all these scenarios. We conclude that dust filtration

DUST FILTRATION BY PLANET-INDUCED GAP EDGES: IMPLICATIONS FOR TRANSITIONAL DISKS

International Nuclear Information System (INIS)

Zhu Zhaohuan; Dong Ruobing; Nelson, Richard P.; Espaillat, Catherine; Hartmann, Lee

2012-01-01

By carrying out two-dimensional two-fluid global simulations, we have studied the response of dust to gap formation by a single planet in the gaseous component of a protoplanetary disk—the so-called dust filtration mechanism. We have found that a gap opened by a giant planet at 20 AU in an α = 0.01, M-dot =10 -8 M ☉ yr -1 disk can effectively stop dust particles larger than 0.1 mm drifting inward, leaving a submillimeter (submm) dust cavity/hole. However, smaller particles are difficult to filter by a gap induced by a several M J planet due to (1) dust diffusion and (2) a high gas accretion velocity at the gap edge. Based on these simulations, an analytic model is derived to understand what size particles can be filtered by the planet-induced gap edge. We show that a dimensionless parameter T s /α, which is the ratio between the dimensionless dust stopping time and the disk viscosity parameter, is important for the dust filtration process. Finally, with our updated understanding of dust filtration, we have computed Monte Carlo radiative transfer models with variable dust size distributions to generate the spectral energy distributions of disks with gaps. By comparing with transitional disk observations (e.g., GM Aur), we have found that dust filtration alone has difficulties depleting small particles sufficiently to explain the near-IR deficit of moderate M-dot transitional disks, except under some extreme circumstances. The scenario of gap opening by multiple planets studied previously suffers the same difficulty. One possible solution is to invoke both dust filtration and dust growth in the inner disk. In this scenario, a planet-induced gap filters large dust particles in the disk, and the remaining small dust particles passing to the inner disk can grow efficiently without replenishment from fragmentation of large grains. Predictions for ALMA have also been made based on all these scenarios. We conclude that dust filtration with planet(s) in the disk is a

SU-F-I-75: Half-Value Layer Thicknesses and Homogeneity Coefficients for Fluoroscopic X-Ray Beam Spectra Incorporating Spectral Filtration

Energy Technology Data Exchange (ETDEWEB)

Wunderle, K [Cleveland Clinic Foundation, Cleveland, OH (United States); Wayne State University School of Medicine, Detroit, MI (United States); Godley, A; Shen, Z; Dong, F [Cleveland Clinic Foundation, Cleveland, OH (United States); Rakowski, J [Wayne State University School of Medicine, Detroit, MI (United States)

2016-06-15

Purpose: The purpose of this investigation is to quantify various first half-value-layers (HVLs), second HVLs and homogeneity coefficients (HCs) for a state-of-the-art fluoroscope utilizing spectral (copper) filtration. Methods: A Radcal (Monrovia, Ca) AccuPro dosimeter with a 10×6-6 calibrated ionization chamber was used to measure air kerma for radiographic x-ray exposures made on a Siemens (Erlangen, Germany) Artis ZeeGo fluoroscope operated in the service mode. The ionization chamber was centered in the x-ray beam at 72 cm from the focal spot with a source-to-image-distance of 120 cm. The collimators were introduced to limit the x-ray field to approximately 5 cm × 5 cm at the ionization chamber plane. Type-1100 aluminum filters, in 0.5 mm increments, were used to determine the HVL. Two HVL calculation methods were used, log-linear interpolation and Lambert-W interpolation as described by Mathieu [Med Phys, 38(8), 4546 (2011)]. Multiple measurements were made at 60, 80, 100, 120 kVp at spectral filtration thicknesses of 0, 0.1, 0.3, 0.6 and 0.9 mm. Results: First HVL, second HVL, and HCs are presented for the fluoroscopic x-ray beam spectra indicated above, with nearly identical results from the two interpolation methods. Accuracy of the set kVp was also determined and deviated less than 2%. First HVLs for fluoroscopic x-ray beam spectra without spectral filtration determined in our study were 7%–16% greater than previously published data by Fetterly et al. [Med Phys, 28, 205 (2001)]. However, the FDA minimum HVL requirements changed since that publication, requiring larger HVLs as of 2006. Additionally, x-ray tube and generator architecture have substantially changed over the last 15 years providing different beam spectra. Conclusion: X-ray beam quality characteristics for state-of-the-art fluoroscopes with spectral filtration have not been published. This study provides reference data which will be useful for defining beam qualities encountered on

Fast Filtration of Bacterial or Mammalian Suspension Cell Cultures for Optimal Metabolomics Results.

Directory of Open Access Journals (Sweden)

Natalie Bordag

Full Text Available The metabolome offers real time detection of the adaptive, multi-parametric response of the organisms to environmental changes, pathophysiological stimuli or genetic modifications and thus rationalizes the optimization of cell cultures in bioprocessing. In bioprocessing the measurement of physiological intracellular metabolite levels is imperative for successful applications. However, a sampling method applicable to all cell types with little to no validation effort which simultaneously offers high recovery rates, high metabolite coverage and sufficient removal of extracellular contaminations is still missing. Here, quenching, centrifugation and fast filtration were compared and fast filtration in combination with a stabilizing washing solution was identified as the most promising sampling method. Different influencing factors such as filter type, vacuum pressure, washing solutions were comprehensively tested. The improved fast filtration method (MxP® FastQuench followed by routine lipid/polar extraction delivers a broad metabolite coverage and recovery reflecting well physiological intracellular metabolite levels for different cell types, such as bacteria (Escherichia coli as well as mammalian cells chinese hamster ovary (CHO and mouse myeloma cells (NS0.The proposed MxP® FastQuench allows sampling, i.e. separation of cells from medium with washing and quenching, in less than 30 seconds and is robustly designed to be applicable to all cell types. The washing solution contains the carbon source respectively the 13C-labeled carbon source to avoid nutritional stress during sampling. This method is also compatible with automation which would further reduce sampling times and the variability of metabolite profiling data.

Is it about "pink" or about "girls"? The inherence heuristic across social and nonsocial domains.

Science.gov (United States)

Kinzler, Katherine D; Sullivan, Kathleen R

2014-10-01

The inherence heuristic provides an intriguing and novel explanation for early thought in a variety of domains. Exploring similarities and differences in inherent reasoning across social and nonsocial domains can help us understand the role that inherent thinking plays in the development of human reasoning and the process by which more elaborate essentialist reasoning develops.

Thermo-resistant filtration fabrics for hot gas extraction

International Nuclear Information System (INIS)

Wierzbowska, T.

1992-01-01

Types and technical and utilizing data of heat resistant filtrating fabrics initiated to production by 'Moratex' and provided for dust extraction of technical gas from various industrial processes have been discussed. (author). 8 refs, 2 tabs

Improved remote HEPA filtration development program

International Nuclear Information System (INIS)

Wilson, C.E. III.

1987-03-01

This paper presents a summary of the prototype development and hot cell mock-up testing program undertaken to adapt a commercial remote HEPA filter housing for use in the Process Facility Modification Project (PFMP). This program was initiated in response to the project design criteria and documentation that required the air from the hot cell environment to be exhausted through three stages of HEPA filtration. Due to the anticipated quantity of radioactive contamination captured by the first stage of filters, it was determined that the first stage would need to be located in a remotely operated and maintained shielded cell adjoining the primary hot cell areas. Commercially available remote filtration equipment was evaluated and candidate unit was identified, which could be developed into a suitable filter housing. A candidate unit was obtained from Flanders Filters, Inc. and a series of hot cell mock-up tests were identified in the 305 facility at the Hanford site. The results of these tests, and further interaction with the vendor, led to a prototype remote filter housing which satisfied most PFMP criteria and proved to be significantly superior to existing commercial units for remote operation/maintenance

Inherently safe in situ uranium recovery

International Nuclear Information System (INIS)

Krumhansl, James Lee; Beauheim, Richard Louis; Brady, Patrick Vane; Arnold, Bill Walter; Kanney, Joseph F.; McKenna, Sean Andrew

2009-01-01

Expansion of uranium mining in the United States is a concern to some environmental groups and sovereign Native American Nations. An approach which may alleviate some problems is to develop inherently safe in situ uranium recovery ('ISR') technologies. Current ISR technology relies on chemical extraction of trace levels of uranium from aquifers that, once mined, can still contain dissolved uranium and other trace metals that are a health concern. Existing ISR operations are few in number; however, high uranium prices are driving the industry to consider expanding operations nation-wide. Environmental concerns and enforcement of the new 30 ppb uranium drinking water standard may make opening new mining operations more difficult and costly. Here we propose a technological fix: the development of inherently safe in situ recovery (ISISR) methods. The four central features of an ISISR approach are: (1) New 'green' leachants that break down predictably in the subsurface, leaving uranium, and associated trace metals, in an immobile form; (2) Post-leachant uranium/metals-immobilizing washes that provide a backup decontamination process; (3) An optimized well-field design that increases uranium recovery efficiency and minimizes excursions of contaminated water; and (4) A combined hydrologic/geochemical protocol for designing low-cost post-extraction long-term monitoring. ISISR would bring larger amounts of uranium to the surface, leave fewer toxic metals in the aquifer, and cost less to monitor safely - thus providing a 'win-win-win' solution to all stakeholders.

Mathematics model of filtration efficiency of moisture separator for nuclear reactors

International Nuclear Information System (INIS)

Zhang Zhenzhong; Jiang Feng; Huang Yunfeng

2010-01-01

In order to study the filtration mechanism of the moisture separator for water droplet of 5∼10μm, this paper set up a physical model. For the mixed meshes, they can be classified into three types: standard meshes, bur meshes and middle meshes. For all fibers of the wire meshes and vertical fibers of standard mixed meshes, a Kuwabara flow field is used to track the particle to get the inertial impaction efficiency and then calculate the total filtration efficiency of the meshes. For other fibers, besides the Kuwabara flow field, an around-flat flow field is added to calculate the efficiency. Lastly, the total efficiency of the moisture separator according to the equation of the filtration efficiency for the filters in series is compared with the experimental data. The result shows that, under the standard condition,the calculation value is consistent with the experimental efficiency data. (authors)

Influence of Inherent Moisture Content on the Deformation ...

African Journals Online (AJOL)

Influence of Inherent Moisture Content on the Deformation. Properties of Coconut Tissues During Mechanical Oil. Expression. *J. J. Mpagalile1 and B. Clarke2. 1Department of ... The study confirmed that moisture content has an important role in the deformation of coconut ..... A micro penetration technique for mechanical.

Optimization of gravity-driven membrane (GDM) filtration process for seawater pretreatment.

Science.gov (United States)

Wu, Bing; Hochstrasser, Florian; Akhondi, Ebrahim; Ambauen, Noëmi; Tschirren, Lukas; Burkhardt, Michael; Fane, Anthony G; Pronk, Wouter

2016-04-15

Seawater pretreatment by gravity-driven membrane (GDM) filtration at 40 mbar has been investigated. In this system, a beneficial biofilm develops on the membrane that helps to stabilize flux. The effects of membrane type, prefiltration and system configuration on stable flux, biofilm layer properties and dissolved carbon removal were studied. The results show that the use of flat sheet PVDF membranes with pore sizes of 0.22 and 0.45 μm in GDM filtration achieved higher stabilized permeate fluxes (7.3-8.4 L/m(2)h) than that of flat sheet PES 100 kD membranes and hollow fibre PVDF 0.1 μm membranes. Pore constriction and cake filtration were identified as major membrane fouling mechanisms, but their relative contributions varied with filtration time for the various membranes. Compared to raw seawater, prefiltering of seawater with meshes at sizes of 10, 100 and 1000 μm decreased the permeate flux, which was attributed to removal of beneficial eukaryotic populations. Optical coherence tomography (OCT) showed that the porosity of the biofouling layer was more significantly related with permeate flux development rather than its thickness and roughness. To increase the contact time between the biofilm and the dissolved organics, a hybrid biofilm-submerged GDM reactor was evaluated, which displayed significantly higher permeate fluxes than the submerged GDM reactor. Although integrating the biofilm reactor with the membrane system displayed better permeate quality than the GDM filtration cells, it could not effectively reduce dissolved organic substances in the seawater. This may be attributed to the decomposition/degradation of solid organic substances in the feed and carbon fixation by the biofilm. Further studies of the dynamic carbon balance are required. Copyright © 2016 Elsevier Ltd. All rights reserved.

Zebra mussel filtration and its potential uses in industrial water treatment.

Science.gov (United States)

Elliott, Paul; Aldridge, David C; Moggridge, Geoff D

2008-03-01

The zebra mussel (Dreissena polymorpha) is a notorious freshwater biofouling pest, and populations of the species can alter aquatic environments through their substantial filtration capabilities. Despite the ecological importance of zebra mussel filtration, many predictions of their large-scale effects on ecosystems rely on extrapolations from filtration rates obtained in static laboratory experiments, not accounting for natural mussel densities, boundary layer effects, flow rates or elevated algal concentrations. This study used large-scale industrial flume trials to investigate the influence of these factors on zebra mussel filtration and proposes some novel industrial applications of these findings. The flume trials revealed some of the highest zebra mussel clearance rates found to date, up to 574+/-20mlh(-1)g(-1) of wet tissue mass. Under low algal concentrations, chlorophyll a removal by zebra mussels was not proportional to mussel density, indicating that field rates of zebra mussel grazing may be much lower than previous studies have predicted. Increasing ambient velocities up to 100mls(-1) ( approximately 4cms(-1)) led to increased clearance rates by zebra mussels, possibly due to the replenishment of locally depleted resources, but higher velocities of 300mls(-1) (12cms(-1)) did not lead to further significant increases in clearance rate. When additional algal cultures were dosed into the flumes, chlorophyll a removal increased approximately logarithmically with zebra mussel density and there were no differences in the clearance of three different species of alga: Ankyra judayi, Pandorina morum and Cyclotella meneghinia. Some novel industrial uses of these zebra mussel filtration studies are proposed, such as: (1) helping to inform models that predict the large-scale grazing effects of the mussels, (2) allowing estimates of zebra mussel densities in industrial pipelines, and (3) constructing large-scale biofilters for use in water clarification.

Test of precoat filtration technology for treatment of swimming pool water.

Science.gov (United States)

Christensen, Morten Lykkegaard; Klausen, Morten Møller; Christensen, Peter Vittrup

2018-02-01

The technical performance of a precoat filter was compared with that of a traditional sand filter. Particle concentration and size distribution were measured before and after the filtration of swimming pool water. Both the sand and precoat filters could reduce the particle concentration in the effluent. However, higher particle removal efficiency was generally observed for the precoat filter, especially for particles smaller than 10 μm in diameter. Adding flocculant improved the removal efficiency of the sand filter, resulting in removal efficiencies comparable to those of the precoat filter. Three powders, i.e., two types of perlite (Harbolite ® and Aquatec perlite) and cellulose fibers (Arbocel ® ), were tested for the precoat filter, but no significant difference in particle removal efficiency was observed among them. The maximum efficiency was reached within 30-40 min of filtration. The energy required for the pumps increased by approximately 35% over a period of 14 days. The energy consumption could be reduced by replacing the powder on the filter cloth. The sand filter was backwashed once a week, while the powder on the precoat filter was replaced every two weeks. Under these conditions, it was possible to reduce the water used for cleaning by 88% if the precoat filter was used instead of the sand filter.

Assessment of glomerular filtration rate and effective renal plasma flow in cystic fibrosis

International Nuclear Information System (INIS)

Spino, M.; Chai, R.P.; Isles, A.F.; Balfe, J.W.; Brown, R.G.; Thiessen, J.J.; MacLeod, S.M.

1985-01-01

A study was conducted to examine renal function in 10 healthy control subjects and eight patients with cystic fibrosis in stable condition. Sequential bolus injections of /sup 99m/Tc-DTPA and 125 I-OIH were administered to assess glomerular filtration rate and effective renal plasma flow, respectively. Blood was subsequently collected for 3 hours, and urine for 24 hours. Renal clearances of both radioisotope markers were virtually identical in patients and controls. Inasmuch as neither glomerular filtration rate nor effective renal plasma flow was enhanced in patients with cystic fibrosis, increased clearance of drugs in these patients is unlikely to be the result of enhanced glomerular filtration or tubular secretion

The Comparative Study of the Measurement of Serum Cystatin C and 99mTc-DTPA for the Measurement of Glomerular Filtration Rate (GFR) in Type 2 Diabetic Nephropathy

International Nuclear Information System (INIS)

Kong Linghua; Wu Junyuan; Gao Bin; Wang Xueqin; Gu Kaikai

2010-01-01

To explore the clinical value between measurement of serum cystatin C (Cys C) and determination of plasma with 99m Tc-DTPA glomerular filtration rate (GFR) clearance for type 2 diabetes (T2DM) in early detection of renal damage, the serum cystatin C levels in 87 patients with type 2 diabetes were determined by immune turbidimetry Cys C. The patients were also carried out dynamic imaging to measure renal GFR. The result showed that the serum levels of Cys C in patients with Type 2 diabetic was 1.68 ± 0.52 mg / L, the normal group was 0.72±0.26 mg/L; The GFR in patients with T2DM was 93.8 ± 30.2 ml/min/1.73m 2 , the control group was 107.48±15.23 ml/min/1.73m 2 , there was significant difference between patients and controls (P 99m Tc-DTPA renal dynamic imaging. The serum Cys C could reflect the damage in early diabetic patients. The method is simple, accurate and easy to spread. The renal dynamic imaging method of GFR determination is slightly complex and requires specialized equipment. It can reflect the sub-renal function. The combined measurement of serum Cys C and GFR are very important in the early detection of type 2 diabetic patients with early renal function. (authors)

Influence of the surface structure on the filtration performance of UV-modified PES membranes

DEFF Research Database (Denmark)

Kæselev, Bozena Alicja; Kingshott, P.; Jonsson, Gunnar Eigil

2002-01-01

chemically characterised using X-ray photoelectron spectroscopy (XPS) and time of flight-static secondary ion mass spectrometry (TOF-static SIMS). The filtration performance of irradiated/non-modified and irradiated/modified membranes was examined in a crossflow cell, using a dextran solution. The filtration...... in relation to dextran when compared to membranes modified by AAG and AAP. This work suggests that the structure of the presence of grafted chains seems to be responsible for the observed changes to filtration performance of the modified membrane. Surface analysis supports the claim that the specific surface...

Polymer filtration: A new technology for selective metals recovery

Energy Technology Data Exchange (ETDEWEB)

Smith, B.F.; Robison, T.W.; Cournoyer, M.E.; Wilson, K.V.; Sauer, N.N.; Mullen, K.I.; Lu, M.T.; Jarvinen, J.J.

1995-04-01

Polymer Filtration (PF) was evaluated for the recovery of electroplating metal ions (zinc and nickel) from rinse waters. Polymer Filtration combines the use of water-soluble metal-binding polymers and ultrafiltration to concentrate metal ions from dilute rinse water solutions. The metal ions are retained by the polymers; the smaller, unbound species freely pass through the ultrafiltration membrane. By using this process the ultrafiltered permeate more than meets EPA discharge limits. The metal ions are recovered from the concentrated polymer solution by pH adjustment using diafiltration and can be recycled to the original electroplating baths with no deleterious effects on the test panels. Metal-ion recovery is accomplished without producing sludge.

Inherent reactor power controller for a metal-fueled ALMR

International Nuclear Information System (INIS)

Wood, R.T.; Wilson, T.L. Jr.

1990-01-01

Inherent power control for metal-fueled ALMR designs involves using reactivity thermal feedback effects to control reactor power. This paper describes how, using classical control design techniques, a control system for normal load following maneuvers was deigned for a pool-type ALMR. This design provides active control of power removal in the balance of plant, direct control of selected primary and intermediate loop temperatures, and passive control of reactor power. The inherent stability of the strong, fast reactivity feedback effects bring heat production in the core into balance with the heat removal system temperatures, which are controlled to meet power demand. A simulation of the control system successfully responded to a 10% step change in power demand by changing power at an acceptable rate without causing large temperature fluctuations or exceeding thermal limits

Nocturnal polyuria is related to absent circadian rhythm of glomerular filtration rate.

Science.gov (United States)

De Guchtenaere, A; Vande Walle, C; Van Sintjan, P; Raes, A; Donckerwolcke, R; Van Laecke, E; Hoebeke, P; Vande Walle, J

2007-12-01

Monosymptomatic nocturnal enuresis is frequently associated with nocturnal polyuria and low urinary osmolality during the night. Initial studies found decreased vasopressin levels associated with low urinary osmolality overnight. Together with the documented desmopressin response, this was suggestive of a primary role for vasopressin in the pathogenesis of enuresis in the absence of bladder dysfunction. Recent studies no longer confirm this primary role of vasopressin. Other pathogenetic factors such as disordered renal sodium handling, hypercalciuria, increased prostaglandins and/or osmotic excretion might have a role. So far, little attention has been given to abnormalities in the circadian rhythm of glomerular filtration rate. We evaluated the circadian rhythm of glomerular filtration rate and diuresis in children with desmopressin resistant monosymptomatic nocturnal enuresis and nocturnal polyuria. We evaluated 15 children (9 boys) 9 to 14 years old with monosymptomatic nocturnal enuresis and nocturnal polyuria resistant to desmopressin treatment. The control group consisted of 25 children (12 boys) 9 to 16 years old with monosymptomatic nocturnal enuresis without nocturnal polyuria. Compared to the control population, children with nocturnal polyuria lost their circadian rhythm not only for diuresis and sodium excretion but also for glomerular filtration rate. Patients with monosymptomatic nocturnal enuresis and nocturnal polyuria lack a normal circadian rhythm for diuresis and sodium excretion, and the circadian rhythm of glomerular filtration rate is absent. This absence of circadian rhythm of glomerular filtration rate and/or sodium handling cannot be explained by a primary role of vasopressin, but rather by a disorder in circadian rhythm of renal glomerular and/or tubular functions.

Semen Quality of Holstein and Buffalo Bulls after Filtration using Sephadex Column

International Nuclear Information System (INIS)

AbdelKhalek, A E; AboulEla, M B; Soheir, A Fawzy; Dandooush E

2008-01-01

To evaluate the effect of sephadex column filtration technique on semen quality of five Holstein bulls and five Egyptian buffalo bulls. Semen was collected biweekly from each eight weeks. Immediately after collection, semen was extended (37degree C) and filtered using sephadex column-filtration technique. Semen was evaluated for physical semen characteristics including, percentages of sperm motility, live sperm and sperm abnormality as well as sperm cell concentration pre-and post-filtration. Results show that among all physical semen characteristics, only ejaculate semen volume was significantly (P<0.001) higher in Holstein than buffalo bulls, but motility, livability, abnormality, sperm concentration and sperm with intact acrosome did not differ between both species. As a result of filtration, sperm motility and livability increased (P<0.05) by 16.4 and 11.8% in Holstein and by 16.9 and 10.1% in buffalo semen, respectively. Sperm abnormality and concentration reduced (P<0.05) by 2.6 and 3.3% in Holstein and by 2.4 and 3.5% in buffalo semen, respectively. Improvements of live sperm and the reduction in sperm concentration (proportional to the pre-filtration value) were better (P<0.05) in Holstein than buffalo semen (15.5% and %52.4 vs. 13.2 and -49.3%, respectively). Improvement of motility and abnormality did not differ in Holstein (25.4 and %57.8) and buffalo semen (26.6 and ,(%54.5respectively. The present results indicate that using sephadex column filter technique has beneficial effects on improving quality of spermatozoa in both species. (author)

Automatic Reporting of Creatinine-Based Estimated Glomerular Filtration Rate in Children: Is this Feasible?

Directory of Open Access Journals (Sweden)

Andrew Lunn

2016-07-01

Full Text Available Creatinine, although widely used as a biomarker to measure renal function, has long been known as an insensitive marker of renal impairment. Patients with reduced renal function can have a creatinine level within the normal range, with a rapid rise when renal function is significantly reduced. As of 1976, the correlation between height, the reciprocal of creatinine, and measured glomerular filtration rate (GFR in children has been described. It has been used to derive a simple formula for estimated glomerular filtration rate (eGFR that could be used at the bedside as a more sensitive method of identifying children with renal impairment. Formulae based on this association, with modifications over time as creatinine assay methods have changed, are still widely used clinically at the bedside and in research studies to assess the degree of renal impairment in children. Adult practice has moved in many countries to computer-generated results that report eGFR alongside creatinine results using more complex, but potentially more accurate estimates of GFR, which are independent of height. This permits early identification of patients with chronic kidney disease. This review assesses the feasibility of automated reporting of eGFR and the advantages and disadvantages of this in children.

Body composition analysis by DEXA by using dynamically changing samarium filtration

DEFF Research Database (Denmark)

Gotfredsen, Arne; Baeksgaard, L; Hilsted, J

1997-01-01

Dual-energy X-ray absorptiometry (DEXA) has a high accuracy for body composition analysis but is influenced by beam hardening and other error sources in the extremes of measurement. To compensate for beam hardening, the Norland XR-36 introduces a dynamically changing samarium filtration system......). Scans of six healthy volunteers covered with combinations of beef and lard (approximately 5-15 kg) showed a good agreement (r = 0.99) between reference and DEXA values of added soft tissue mass and fat percentage. We conclude that the DEXA method (and, in particular, the Norland XR-36 using dynamic...

Results and implications of the EBR-II inherent safety demonstration tests

International Nuclear Information System (INIS)

Planchon, H.P.; Golden, G.H.; Sackett, J.I.; Mohr, D.; Chang, L.K.; Feldman, E.E.; Betten, P.R.

1987-01-01

On April 3, 1986 two milestone tests were conducted in Experimental Breeder Reactor-2 (EBR-II). The first test was a loss of flow without scram and the second was a loss of heat sink without scram. Both tests were initiated from 100% power and in both tests the reactor was shut down by natural processes, principally thermal expansion, without automatic scram, operator intervention or the help of special in-core devices. The temperature transients during the tests were mild, as predicted, and there was no damage to the core or reactor plant structures. In a general sense, therefore, the tests plus supporting analysis demonstrated the feasibility of inherent passive shutdown for undercooling accidents in metal-fueled LMRs. The results provide a technical basis for future experiments in EBR-II to demonstrate inherent safety for overpower accidents and provide data for validation of computer codes used for design and safety analysis of inherently safe reactor plants

Experimental evidence for inherent Lévy search behaviour in foraging animals.

Science.gov (United States)

Kölzsch, Andrea; Alzate, Adriana; Bartumeus, Frederic; de Jager, Monique; Weerman, Ellen J; Hengeveld, Geerten M; Naguib, Marc; Nolet, Bart A; van de Koppel, Johan

2015-05-22

Recently, Lévy walks have been put forward as a new paradigm for animal search and many cases have been made for its presence in nature. However, it remains debated whether Lévy walks are an inherent behavioural strategy or emerge from the animal reacting to its habitat. Here, we demonstrate signatures of Lévy behaviour in the search movement of mud snails (Hydrobia ulvae) based on a novel, direct assessment of movement properties in an experimental set-up using different food distributions. Our experimental data uncovered clusters of small movement steps alternating with long moves independent of food encounter and landscape complexity. Moreover, size distributions of these clusters followed truncated power laws. These two findings are characteristic signatures of mechanisms underlying inherent Lévy-like movement. Thus, our study provides clear experimental evidence that such multi-scale movement is an inherent behaviour rather than resulting from the animal interacting with its environment. © 2015 The Author(s) Published by the Royal Society. All rights reserved.

Filtration in the Use of Individual Water Purification Devices

National Research Council Canada - National Science Library

Lundquist, Arthur; Clarke, Steven; Bettin, William

2006-01-01

.... Understanding the ability of filtration to reduce disease-causing microorganisms in water is important in protecting Soldiers, who are considering using this technology, from acute health threats...

Filtration engineering study to upgrade the ETF

International Nuclear Information System (INIS)

McDonald, F.N.N.

1995-01-01

Filtration technologies are evaluated which have potential to augment or upgrade the 200 Area Effluent Treatment Facility. The study was written in anticipation of treating future waste waters that have high fouling potentials. The Three ultrafilters judged to be capable of treating future waste waters are: hollow fiber, tubular, and centrifugal

Improvement of municipal wastewater pretreatment by direct membrane filtration.

Science.gov (United States)

Nascimento, Thiago A; Mejía, Fanny R; Fdz-Polanco, Fernando; Peña Miranda, Mar

2017-10-01

The high content of particulate matter in municipal wastewater hinders the conventional anaerobic treatments at psychrophilic temperatures. The hydrolysis of the particulate chemical oxygen demand (pCOD) could be the limiting step under these conditions. Therefore, new pretreatments or improved conventional pretreatments are needed in order to separate pCOD. In this work, direct membrane filtration of municipal wastewater, using an ultrafiltration membrane, was investigated. This intensive pretreatment, which aims to separate soluble chemical oxygen demand (sCOD) and to concentrate pCOD, together with anaerobic treatments of both streams at psychrophilic and mesophilic conditions respectively, could be an alternative to the conventional activated sludge process. The obtained results show a removal yield of 24.9% of the total solids (TS) and 45% of total chemical oxygen demand (tCOD), obtaining a permeate free of suspended solids. This physical removal implies the accumulation of solids inside the membrane tank, reaching the values of 45.4 and 4.4 g/L of TS in the sedimentation and filtration sections, respectively. The membrane operated with filtration, backwashing cycles and continuous gas sparging, with a permeate flux predominantly around 10 L/(m 2  h). The results show the viability of the technology to concentrate pCOD and so to improve energy recovery from municipal wastewater.

Cake filtration modeling: Analytical cake filtration model and filter medium characterization

Energy Technology Data Exchange (ETDEWEB)

Koch, Michael

2008-05-15

Cake filtration is a unit operation to separate solids from fluids in industrial processes. The build up of a filter cake is usually accompanied with a decrease in overall permeability over the filter leading to an increased pressure drop over the filter. For an incompressible filter cake that builds up on a homogeneous filter cloth, a linear pressure drop profile over time is expected for a constant fluid volume flow. However, experiments show curved pressure drop profiles, which are also attributed to inhomogeneities of the filter (filter medium and/or residual filter cake). In this work, a mathematical filter model is developed to describe the relationship between time and overall permeability. The model considers a filter with an inhomogeneous permeability and accounts for fluid mechanics by a one-dimensional formulation of Darcy's law and for the cake build up by solid continuity. The model can be solved analytically in the time domain. The analytic solution allows for the unambiguous inversion of the model to determine the inhomogeneous permeability from the time resolved overall permeability, e.g. pressure drop measurements. An error estimation of the method is provided by rewriting the model as convolution transformation. This method is applied to simulated and experimental pressure drop data of gas filters with textile filter cloths and various situations with non-uniform flow situations in practical problems are explored. A routine is developed to generate characteristic filter cycles from semi-continuous filter plant operation. The model is modified to investigate the impact of non-uniform dust concentrations. (author). 34 refs., 40 figs., 1 tab

Iser: an international inherently safe reactor concept

International Nuclear Information System (INIS)

Wakabayashi, Hiroaki

1988-01-01

Iser is a modular standardised 200-300 MWe power reactor based on the PIUS principle. It differs from PIUS in being simpler, and making full use of existing steel-vessel-based LWR technology. Iser is an inherently safe reactor concept under development in Japan. It is a generic concept, not a patented commodity, and it is expected that an international association to develop the concept will be formed. (U.K.)

Clinical dehydration and glomerular filtration rate in acute paediatric gastroenteritis.

Science.gov (United States)

Milani, Gregorio P; Fossali, Emilio F; Perri, Alessandra; Vettori, Arianna; Grillo, Paolo; Agostoni, Carlo

2013-08-01

To evaluate changes in glomerular filtration rate in acute gastroenteritis. The correlation between two clinical diagnostic scales and glomerular filtration rate has been investigated in 113 children with acute gastroenteritis in a paediatric emergency setting. A significant reduction of GFR was found in 10% children less than, and 5% children higher than, 2 years of age with acute gastroenteritis. The differences observed as for risk of renal hypoperfusion suggests to consider the age of children as an important determinant to consider the dehydration status in acute gastroenteritis. ©2013 Foundation Acta Paediatrica. Published by John Wiley & Sons Ltd.

Impacts of reactivity feedback uncertainties on inherent shutdown in innovative designs

International Nuclear Information System (INIS)

Mueller, C.J.

1986-01-01

The concept of inherent shutdown is emphasized in the approach to the design of innovative, small pool-type liquid-metal reactors (LMRs). This paper reports an evaluation of reactivity feedback uncertainties used in the analyses of anticipated transients without scram for innovative LMRs, and the associated impacts on safety margins and inherent shutdown success probabilities on unprotected loss-of-flow (LOF) events. It then assesses the ultimate importance of these uncertainties on LOF and transient overpower events in evolving metal and oxide innovative designs

Impacts of reactivity feedback uncertainties on inherent shutdown in innovative designs

International Nuclear Information System (INIS)

Mueller, C.J.

1986-01-01

The concept of ''inherent shutdown'' is emphasized in the approach to the design of innovative, small pool-type liquid metal reactors (LMRs). This paper reports an evaluation of reactivity feedback uncertainties used in the analyses of anticipated transients without scram (ATWS) for innovative LMRs, and the associated impacts on safety margins and inherent shutdown success probabilities on unprotected loss-of-flow (LOF) events. It then assesses the ultimate importance of these uncertainties on LOF and transient overpower (TOP) events in evolving metal and oxide innovative designs

Bench-scale cross flow filtration of Tank S-107 sludge slurries and Tank C-107 supernatant

International Nuclear Information System (INIS)

Geeting, J.G.H.; Reynolds, B.A.

1996-10-01

Hanford tank waste filtration experiments were conducted using a bench-scale cross flow filter on 8 wt%, 1.5 wt%, and 0.05 wt% Tank S- 107 sludge slurries and on Tank C-107 supernatant. For comparison, two simulants each with solids loadings of 8 wt% and 0.05 wt% were also tested. The purpose of the tests was to determine the efficacy of cross flow filtration on slurries of various solids loadings. -In addition, filtrate flux dependency on axial velocity and transmembrane pressure was sought so that conditions for future experiments might be better selected. The data gathered are compared to the simulants and three cross flow filtration models. A two- parameter central composite design which tested. transmembrane pressure from 5 to 40 psig and axial Velocity from 3 to 9 ft/s was used for all feeds. The cross flow filter effectively removed solids from the liquid, as 19 of 20 filtrate samples had particle concentrations below the resolution limit of the photon correlation spectrometer used in the Hanford Radiocolloid Laboratory. Radiochemical analysis indicate that all filtrate samples were below Class A waste classification standards for 9OSr and transuranics

The effect of anode surface roughness on radiation output for diagnostic x-ray sources

International Nuclear Information System (INIS)

Meghzifene, K.; Nowotny, R.; Aiginger, H.

2002-01-01

The calculation of entrance surface dose to patients in diagnostic radiology from tube output data is determined by often-unknown sources of inherent filtration. One of these sources is the roughness of the anode surface increasing with tube ageing. This effect increases the inherent filtration of the x-ray tube noticed by a reduced radiation output and increased half-value layers (HVL). To study this effect used rotating anodes were collected and the surface profile of 8 focal tracks was measured in radial direction using an instrument with a diamond tipped stylus (90 deg. tip, 1 μm radius). Surface roughness was determined as the arithmetic mean R a of the deviation in the profile from the centre line for 200 μm reference lengths ranging from 1.32 μm (sandblasted finish without surface degradation) to 5.22 μm (a track for a small focus). The surface profiles were then used to calculate x-ray spectra using a computer code. For each surface about 40000 spectra were calculated with the electrons entering the anode at random position and spectral parameters were then determined. The simulation showed that for rough surfaces the x-rays have to penetrate an additional absorbing layer of tungsten increasing in thickness with anode roughness. The anode with the roughest focal track (R a =5.22 μm) yields a mean additional absorber thickness in direction of the x-ray beam of about 18 μm. The corresponding loss in air kerma for this anode was about 20% at 70 kVp. The effect on mean photon energy is rather small but highest at 70 kVp (+1 keV at R a =5.22 μm) and lowest at 140 kVp (∼0 keV). This is due to the K-edge in the attenuation coefficients of tungsten at 69.5 keV. Beam hardening is thus reduced for higher voltages as absorption at lower photon energies is balanced by higher absorption above the K-edge while at lower voltages beam hardening is fully effective. The pattern of changes in HVL is more complex but in essence also reflects voltage, roughness and

Application of Combined Cake Filtration-Complete Blocking Model to Ultrafiltration of Skim Milk

Directory of Open Access Journals (Sweden)

Mansoor Kazemimoghadam

2017-10-01

Full Text Available Membrane ultrafiltration (UF is widely used in dairy industries like milk concentration and dehydration processes. The limiting factor of UF systems is fouling which is defined as the precipitation of solutes in the form of a cake layer on the surface of the membrane. In this study, the combined cake filtration-complete blocking model was compared to cake filtration mechanism for flux data through ultrafiltration of skim milk at constant flow rate. The resistance data also was modeled using cake filtration model and standard blocking model. The effect of different trans-membrane pressures and temperatures on flux decline was then investigated. Based on the results obtained here, the combined complete blocking-cake formation model was in excellent agreement with experimental data. The cake filtration model also provided good data fits and can be applied to solutions whose solutes tend to accumulate on the surface of the membrane in the form of a cake layer. With increasing pressure, the differences between the model and experimental data increased.

Enhanced treatment of secondary municipal wastewater effluent: comparing (biological) filtration and ozonation in view of micropollutant removal, unselective effluent toxicity, and the potential for real-time control.

Science.gov (United States)

Chys, Michael; Demeestere, Kristof; Ingabire, Ange Sabine; Dries, Jan; Van Langenhove, Herman; Van Hulle, Stijn W H

2017-07-01

Ozonation and three (biological) filtration techniques (trickling filtration (TF), slow sand filtration (SSF) and biological activated carbon (BAC) filtration) have been evaluated in different combinations as tertiary treatment for municipal wastewater effluent. The removal of 18 multi-class pharmaceuticals, as model trace organic contaminants (TrOCs), has been studied. (Biological) activated carbon filtration could reduce the amount of TrOCs significantly (>99%) but is cost-intensive for full-scale applications. Filtration techniques mainly depending on biodegradation mechanisms (TF and SSF) are found to be inefficient for TrOCs removal as a stand alone technique. Ozonation resulted in 90% removal of the total amount of quantified TrOCs, but a post-ozonation step is needed to cope with an increased unselective toxicity. SSF following ozonation showed to be the only technique able to reduce the unselective toxicity to the same level as before ozonation. In view of process control, innovative correlation models developed for the monitoring and control of TrOC removal during ozonation, are verified for their applicability during ozonation in combination with TF, SSF or BAC. Particularly for the poorly ozone reactive TrOCs, statistically significant models were obtained that correlate TrOC removal and reduction in UVA 254 as an online measured surrogate parameter.

Potential study of bed filtration characteristics in impressed boreholes by radon tracer technique

International Nuclear Information System (INIS)

Litvinov, A.A.; Pinkenzon, D.B.; Makarov, M.S.; Vinarskij, M.S.

1977-01-01

Potential study of bed filtration characteristics in impressed boreholes by radon tracer method is shown. Effects recorded by radon tracer result from gamma radiation of short-living radon decay daughter products. During filtration of tracer through punched holes, cement stone, and rocks the products are deposited and cause a local effect for 2-3 hours. There is a shortage of short-living products in filtrated radon liquid and for some time (which is necessary for production of notable quantity of new decay products) it is practically not a gamma emitter. It is shown that the feature of effect formation governs the technique for well logging as well as interpretation of the results obtained

Water quality and treatment of river bank filtrate

NARCIS (Netherlands)

De Vet, W.W.J.M.; Van Genuchten, C.C.A.; Van Loosdrecht, M.C.M.; Van Dijk, J.C.

2010-01-01

In drinking water production, river bank filtration has the advantages of dampening peak concentrations of many dissolved components, substantially removing many micropollutants and removing, virtually completely, the pathogens and suspended solids. The production aquifer is not only fed by the

Water quality and treatment of river bank filtrate

NARCIS (Netherlands)

De Vet, W.W.J.M.; Van Genuchten, C.C.A.; Van Loosdrecht, M.C.M.; Van Dijk, J.C.

2009-01-01

In drinking water production, river bank filtration has the advantages of dampening peak concentrations of many dissolved components, substantially removing many micropollutants and removing, virtually completely, the pathogens and suspended solids. The production aquifer is not only fed by the

Scaling and particulate fouling in membrane filtration systems

NARCIS (Netherlands)

Boerlage, S.F.E.

2001-01-01

Membrane filtration technologies have emerged as cost competitive and viable techniques in drinking and industrial water production. Despite advancements in membrane manufacturing and technology, membrane scaling and fouling remain major problems and may limit future growth in the industry. Scaling

Studies on soy protein isolate/polyvinyl alcohol hybrid nanofiber membranes as multi-functional eco-friendly filtration materials

International Nuclear Information System (INIS)

Fang, Qun; Zhu, Ming; Yu, Siruo; Sui, Gang; Yang, Xiaoping

2016-01-01

Highlights: • Biodegradable filtration membranes were prepared. • Polar groups in the membrane surface helped capture fine particles. • Loading filtration efficiency can reach 99.99% in the case of small pressure drop. • Filtration membrane showed antimicrobial activity to Escherichia coli. - Abstract: A biodegradable and multifunctional air filtration membrane was prepared by electrospinning of soy protein isolate (SPI)/polyvinyl alcohol (PVA) system in this paper. The optimized SPI/PVA proportion in the spinning solution was determined according to the analyses of microstructure, surface chemical characteristic and mechanical property of the hybrid nanofiber membranes. Under the preferred preparation condition, two kinds of polymer materials displayed a good compatibility in the hybrid nanofibers, and a large number of polar groups existed in the membrane surface. The loading filtration efficiency of the nanofiber membrane with optimal material ratio and areal density can reach 99.99% after test of 30 min for fine particles smaller than 2.5 μm in the case of small pressure drop. Besides, this kind of filtration membrane showed an antimicrobial activity to Escherichia coli in the study. The SPI/PVA hybrid nanofiber membrane with proper material composition and microstructure can be used as a new type of high performance eco-friendly filtration materials.

Studies on soy protein isolate/polyvinyl alcohol hybrid nanofiber membranes as multi-functional eco-friendly filtration materials

Energy Technology Data Exchange (ETDEWEB)

Fang, Qun; Zhu, Ming; Yu, Siruo; Sui, Gang, E-mail: suigang@mail.buct.edu.cn; Yang, Xiaoping

2016-12-15

Highlights: • Biodegradable filtration membranes were prepared. • Polar groups in the membrane surface helped capture fine particles. • Loading filtration efficiency can reach 99.99% in the case of small pressure drop. • Filtration membrane showed antimicrobial activity to Escherichia coli. - Abstract: A biodegradable and multifunctional air filtration membrane was prepared by electrospinning of soy protein isolate (SPI)/polyvinyl alcohol (PVA) system in this paper. The optimized SPI/PVA proportion in the spinning solution was determined according to the analyses of microstructure, surface chemical characteristic and mechanical property of the hybrid nanofiber membranes. Under the preferred preparation condition, two kinds of polymer materials displayed a good compatibility in the hybrid nanofibers, and a large number of polar groups existed in the membrane surface. The loading filtration efficiency of the nanofiber membrane with optimal material ratio and areal density can reach 99.99% after test of 30 min for fine particles smaller than 2.5 μm in the case of small pressure drop. Besides, this kind of filtration membrane showed an antimicrobial activity to Escherichia coli in the study. The SPI/PVA hybrid nanofiber membrane with proper material composition and microstructure can be used as a new type of high performance eco-friendly filtration materials.

Quantification of Inherent Respirable Dust Generation Potential (IRDGP) of South African Coals

CSIR Research Space (South Africa)

Phillips, H

2003-08-01

Full Text Available Advisory Committee Project Summary Project Title: Inherent Respirable Dust Generation Potential (IRDGP) of South African Coals-SIM020604 Author(s): H.R.Phillips and B. K. Belle Agency: University of Witwatersrand Report Date: July2003... Related Projects: Health 607, Sim 02-06-03 Category: Occupational Health Applied Research Occupational Hygiene Summary Project SIM020604 was formulated to determine the Inherent Respirable Dust Generation Potential (IRDGP) of various South...

Filtration track membranes and their biomedical applications; Trekowe membrany filtracyjne oraz ich zastosowania biomedyczne

Energy Technology Data Exchange (ETDEWEB)

Buczkowski, M; Wawszczak, D; Starosta, W [Institute of Nuclear Chemistry and Technology, Warsaw (Poland)

1997-10-01

The characteristics of track filtration membranes has been performed. The investigation of radiation resistance has been carried out for different types of polymer foil used as a membrane material. Biomedical applications of track filtration membranes have been presented and discussed. 10 refs, 10 figs.

Non-stationary open-flow filtration of ground waters at the Pripyat'-Dnieper inter river

International Nuclear Information System (INIS)

Tarapon, A.G.

1989-01-01

Consideration is given to filtration of ground waters into rivers and to effect of drainage devices. Investigations were conducted with use of modelling of planned and profile filtration of ground waters at the electric models. Efficiency of engineering protection facilities suggested, was studied to prevent contamination of water intakes. Modelling shown, that contamination washing out process was in a cycle character with 1 year period. Use of drainage canal with the water level 0.8 m lower than in the river, is an effective way to prevent filtration of ground waters into the Pripyat' and the Dnieper from the upper open-flow aquiver

Comparison of glomerular filtration rates derived from dynamic renal imaging and dual sample clearance in kidney transplantation

International Nuclear Information System (INIS)

Zhu Yangjun; Li Linfa; Zhang Jun; Du Xiaoying

2007-01-01

Objective: Glomerular filtration rate (GFR) is one of the valuable indictors of allograft status after kidney transplantation. The feasibility of an easy measurement of GFR by dynamic renal imaging (dGFR) was assessed in comparison to a classical dual plasma sample method (tGFR) in the current study for evaluating the function of grafting kidney. Methods: In 73 patients of kidney transplantation, both dynamic renal imaging and dual sample GFR measurement were undertaken after 99 Tc m -DTPA injection. The correlation between dGFR and tGFR, both being standardized according to surface area, was analyzed and the linear regression equation was obtained. Results: The mean dGFR was slightly lower than that of tGFR (t=-2.010, P<0.05). The dGFR correlated significantly with tGFR (r=0.759, P< 0.01). The linear regression equation was tGFR=0.6455 x dGFR + 25.514. Conclusion: The dGFR correlated well with tGFR and they were accurate in evaluating the filtration function of transplanted kidney. (authors)

[THE CYTOMETRIC TECHNIQUE OF BINDING OF EOSIN-5-MALEIMIDE IN DIAGNOSTIC OF INHERENT SPHEROCYTOSIS].

Science.gov (United States)

Kuzminova, J A; Plyasunova, S A; Jogov, V V; Smetanina, N S

2016-03-01

The laboratory diagnostic of inherent spherocytosis is based on detection of spherocytes in peripheral blood, decreasing of index of sphericity, decreasing of osmotic resistance of erythrocytes. The new test of diagnostic of hereditary spherocytosis build on molecular defect was developed on the basis of binding extracellular fragments of protein of band 3 with eosin-5-maleimide (EMA-test). The study was carried out to implement comparative analysis of sensitivity and specificity of techniques applied to diagnose inherent spherocytosis. The sampling of 94 patients with various forms of anemias was analyzed All patients were applied complex clinical laboratory examination including analysis of osmotic resistance of erythrocytes, erythrocytometry and EMA-test as specific techniques of diagnostic of inherent spherocytosis. In 51 out of 94 patients (54%) decreasing of values of EMA-test was detected and in 47 patients diagnosis of inherent spherocytosis was confirmed. The standard values of EMA-test were established in 43 patients (46%) and 12 patients out of them with established diagnosis of inherent spherocytosis. Therefore, sensitivity of EMA-test made up to 79% and specificity - 80%. The most sensitive techniques of diagnostic remain osmotic resistance of erythrocytes (91%) and index of sphericity (up to 96%). But the highest specificity in this respect has EMA-test (80%). Nowadays, none of implemented techniques of diagnostic of inherent spherocytosis can be applied as a universal one. The implementation of complex examination is needed for proper diagnostic of disease.

Renal filtration function in patients with gout

Directory of Open Access Journals (Sweden)

N. N. Kushnarenko

2016-01-01

Full Text Available Aim. To study circadian blood pressure (BP profile in patients with gout depending on the presence of arterial hypertension (HT and their relationship to the renal filtration function.Material and methods. Patients with gout (n=87 were included into the study. All the patients underwent ambulatory BP monitoring (ABPM with the assessment of circadian BP profile, determination of uric acid serum levels, glomerular filtration rate (GFR was evaluated by CKD-EPI method. Depending on GFR level, all the patients were divided into 2 groups - with renal dysfunction or without one.Results. ABPM revealed circadian BP dysregulation in 55% of gout patients both with HT and without HT. Chronic kidney disease (CKD was revealed in 72.4% of male patients, with the prevalence in patients with HT (76.6 vs 61%; p<0.001. Correlations between uric acid levels and some ABPM indicators and GFR were determined.Conclusion. Obtained data suggest the contribution of hyperuricemia in disorders of systemic and renal hemodynamics, leading to the early development of CKD.

Mercaptoacetyltriglycine-3 renogram is not superior to estimated glomerular filtration rate measurement for the prediction of long-term renal function after nephrectomy

International Nuclear Information System (INIS)

Kanamaru, Hiroshi; Yamamoto, Masakazu; Nagahama, Kanji

2011-01-01

The objective of this study was to evaluate the clinical usefulness of effective renal plasma flow (ERPF) measured using preoperative mercaptoacetyltriglycine-3 (MAG3) renogram for the prediction of chronic renal insufficiency after nephrectomy. A total of 47 patients underwent preoperative MAG3 renal scintigraphy and subsequent unilateral nephrectomy. Correlations between the 5-year postoperative estimated glomerular filtration rate (eGFR) and the preoperative ERPF of the contralateral kidney (cERPF), ERPF of the diseased kidney (dERPF), total ERPF (tERPF), cERPF to dERPF ratio, serum creatinine (sCr) level, eGFR, as well as the influence of preoperative comorbidities (diabetes, hypertension) on the postoperative eGFR, were evaluated with both univariate and multivariate analyses. Multiple linear regression analysis showed that preoperative cERPF significantly correlated with postoperative eGFR. However, a much stronger correlation was observed between the preoperative and postoperative eGFR. Multiple logistic regression analysis showed that only preoperative eGFR was a significant predicator of the development of advanced-stage chronic kidney disease (CKD). Preoperative MAG3 renogram is not superior to eGFR measurement as a prognostic indicator of long-term renal function after unilateral nephrectomy. (author)

Vacuum distillation/vapor filtration water recovery, phases 1 and 2

Science.gov (United States)

Honegger, R. J.; Remus, G. A.; Krug, E. K.

1973-01-01

The research is reported on the development of an evaporator for vacuum distillation/vapor filtration VD/VF water reclamation system for use on manned space flights. The design, fabrication, and tests of a six-man evaporator are described. It is concluded that: (1) A condenser with an internal rotating impeller and coolant surfaces directly opposite the condensing surfaces is an effective condenser. (2) The VD/VF evaporator, catalyst unit and condenser function satisfactorily based on thermal, mechanical and recovery performance during a 145-hour evaluation test. (3) The quality of recovered water, as measured by analyses for total organic carbon, pH, conductivity, turbidity, and viable bacteria density was within established limits for potability.

Batch cooling crystallization and pressure filtration of sulphathiazole

DEFF Research Database (Denmark)

Häkkinen, Antti; Pöllänen, Kati; Karjalainen, Milja

2005-01-01

Currently there is a great interest in new process analytical approaches to increase the process understanding of pharmaceutical unit operations. In the present study, the influence of the solvent composition on the material properties and, further, on the filtration characteristics, of different...

Customisation of a Monte Carlo dosimetry tool for dental cone-beam CT systems

International Nuclear Information System (INIS)

Stratis, A.; Lopez-Rendon, X.; Jacobs, R.; Zhang, G.; Bogaerts, R.; Bosmans, H.

2016-01-01

A versatile EGSnrc Monte Carlo (MC) framework, initially designed to explicitly simulate X-ray tubes and record the output data into phase space data files, was modified towards dental cone-beam computed tomography (CBCT) dosimetric applications by introducing equivalent sources. Half value layer (HVL) measurements were conducted to specify protocol-specific energy spectra. Air kerma measurements were carried out with an ionisation chamber positioned against the X-ray tube to obtain the total filtration attenuation characteristics. The framework is applicable to bow-tie and non-bow-tie inherent filtrations, and it accounts for the anode heel effect and the total filtration of the tube housing. The code was adjusted to the Promax 3D Max (Planmeca, Helsinki, Finland) dental CBCT scanner. For each clinical protocol, calibration factors were produced to allow absolute MC dose calculations. The framework was validated by comparing MC calculated doses and measured doses in a cylindrical water phantom. Validation results demonstrate the reliability of the framework for dental CBCT dosimetry purposes. (authors)

Treatment of exhausted tannin liquors of the leather industry by nano filtration; Tratamiento por nanofiltracion de los licores agotados de taninos en la industria del curtido

Energy Technology Data Exchange (ETDEWEB)

Adzet, J.; Buonomenna, M. G.; Cassano, A.; Drioli, E.; Molineri, R.

2002-07-01

The use of a nano filtration process is described in order to rationalize the vegetable tonnage step in leather industry through the recovery of tannins from the exhausted baths and their reuse as tanning agents. The results obtained on pilot scale using a membrane module, identified after a screening of various nano filtration membranes, the operating and fluid-dynamic conditions and the mass balance of the nano filtration process are reported and discussed. Skins treated with the recovered solutions revealed chemical and physical parameters very similar to those measured on control skins tanned with standard solutions. According to the obtained results, it is possible to suggest a process scheme that, starting from the exhausted tanning baths, through a nano filtration membrane purification/concentration, permits to increase the tannin/non tannin ratio of the retentate solution. Advantages are in terms of: reduction of environmental impact, simplification of cleaning-up processes of wastewaters, decrease of disposal costs, saving of chemicals and water. (Author)

Formation and filtration characteristics of solids generated in a high level liquid waste treatment process. Filtration characteristics of solids formed in simulated high level liquid waste

International Nuclear Information System (INIS)

Kondo, Y.; Kubota, M.

1997-01-01

The filtration characteristics of solids generated in a simulated high level liquid waste (HLLW) were experimentally examined, when the simulated HLLW was processed according to the ordinary way of actual HLLW treatment process. The filtration characteristics of solids depended on the particle size. The phosphomolybdic acid, which was very fine particle with about 0.1 μm diameter, made slurry a 'difficult-to-filter' slurry, if the phosphomolybdic acid content (wt%) to the whole solids in a slurry exceeded 50wt%. On the contrary, the zirconium compounds (zirconium molybdate and zirconium telluride) had positive effect on filtration characteristics because of their relatively large particle size of about 3 to 5 μm. When the zirconium compounds content was above 50 wt%, slurry became a 'easy-to-filter' slurry. A centrifugal sedimentation was discussed as a solid/liquid separation technique for very fine particles such as phosphomolybdic acid. The theoretical feed flow rate corresponded to 0.1 μm diameter particles was about 20 1/h at the centrifugal acceleration of about 8000 G. (author)

Experimental study of head loss and filtration for LOCA debris

International Nuclear Information System (INIS)

Rao, D.V.; Souto, F.J.

1996-02-01

A series of controlled experiments were conducted to obtain head loss and filtration characteristics of debris beds formed of NUKON trademark fibrous fragments, and obtain data to validate the semi-theoretical head loss model developed in NUREG/CR-6224. A thermally insulated closed-loop test set-up was used to conduct experiments using beds formed of fibers only and fibers intermixed with particulate debris. A total of three particulate mixes were used to simulate the particulate debris. The head loss data were obtained for theoretical fiber bed thicknesses of 0.125 inches to 4.0 inches; approach velocities of 0.15 to 1.5 ft/s; temperatures of 75 F and 125 F; and sludge-to-fiber nominal concentration ratios of 0 to 60. Concentration measurements obtained during the first flushing cycle were used to estimate the filtration efficiencies of the debris beds. For test conditions where the beds are fairly uniform, the head loss data were predictable within an acceptable accuracy range by the semi-theoretical model. The model was equally applicable for both pure fiber beds and the mixed beds. Typically the model over-predicted the head losses for very thin beds and for thin beds at high sludge-to-fiber mass ratios. This is attributable to the non-uniformity of such debris beds. In this range the correlation can be interpreted to provide upper bound estimates of head loss. This is pertinent for loss of coolant accidents in boiling water reactors

Particle size distribution as a new measuring quantity in waste water filtration; Partikelgroessenverteilung als neue Messgroesse in der Abwasserfiltration

Energy Technology Data Exchange (ETDEWEB)

Herwig, V.; Tiehm, A.; Neis, U. [Technische Univ. Hamburg-Harburg, Hamburg (Germany). Arbeitsbereich Abwasserwirtschaft

1999-07-01

The transport and distribution of anthropogenous water constituents are closely related to the behaviour of suspended solids. At municipal sewage treatment plants the elimination of solids takes place as a rule through sedimentation in sedimentation tanks. Because of more stringent cleaning requirements, a chamber filter is frequently added downstream for further elimination of suspended solids. Only through the combination of sedimentation and chamber filtration is reliable retention of solids and associated pollutants or nutrients safeguarded. This work aims to gain better understanding of the processes in the filter through a methodically new approach. This will form the basis for optimized dimensioning and more economical operation of interconnected elimination of solids through sedimentation and filtration. (orig.) [German] Der Transport und die Verteilung anthropogener Wasserinhaltsstoffe steht in engem Zusammenhang mit dem Verhalten der suspendierten Feststoffen. Die Feststoffabtrennung erfolgt in kommunalen Klaeranlagen in der Regel durch Sedimentation in der Nachklaerung. Aufgrund verschaerfter Reinigungsanforderungen wird zur weitergehenden Entfernung der suspendierten Feststoffe haeufig ein Raumfilter nachgeschaltet. Erst durch die Kombination von Sedimentation/Raumfiltration wird ein sicherer Rueckhalt der Feststoffe und assoziierter Schad- sowie Naehrstoffe erreicht. Ziel dieser Arbeit ist es, mit einem methodisch neuen Ansatz zu einem besseren Verstaendnis der Prozesse im Raumfilter zu gelangen. Dieses bildet die Grundlage fuer die optimierte Bemessung und einen oekonomischeren Betrieb der Feststoffseparation im Verbund Nachklaerung/Raumfiltration. (orig.)

Modeling Non-Fickian Transport and Hyperexponential Deposition for Deep Bed Filtration

DEFF Research Database (Denmark)

Yuan, Hao; Shapiro, Alexander

2010-01-01

An integral model of the deep bed filtration process has been developed. It incorporates pore and particle size distributions, as well as the particle residence time distribution in the framework of the continuous time random walk theory. Numerical modeling is carried out to study the factors...... influencing breakthrough curves and deposition profiles for the deep bed filtration systems. Results are compared with a large set of experimental observations. Our findings show that highly dispersed breakthrough curves, e.g. those with early arrivals and large ending tails, correspond to large dispersion...

Application of design for six sigma methodology on portable water filter that uses membrane filtration system: A preliminary study

Science.gov (United States)

Fahrul Hassan, Mohd; Jusoh, Suhada; Zaini Yunos, Muhamad; Arifin, A. M. T.; Ismail, A. E.; Rasidi Ibrahim, M.; Zulafif Rahim, M.

2017-09-01

Portable water filter has grown significantly in recent years. The use of water bottles as a water drink stuff using hand pump water filtration unit has been suggested to replace water bottled during outdoor recreational activities and for emergency supplies. However, quality of water still the issue related to contaminated water due to the residual waste plants, bacteria, and so on. Based on these issues, the study was carried out to design a portable water filter that uses membrane filtration system by applying Design for Six Sigma. Design for Six Sigma methodology consists of five stages which is Define, Measure, Analyze, Design and Verify. There were several tools have been used in each stage in order to come out with a specific objective. In the Define stage, questionnaire approach was used to identify the needs of portable water filter in the future from potential users. Next, Quality Function Deployment (QFD) tool was used in the Measure stage to measure the users’ needs into engineering characteristics. Based on the information in the Measure stage, morphological chart and weighted decision matrix tools were used in the Analyze stage. This stage performed several activities including concept generation and selection. Once the selection of the final concept completed, detail drawing was made in the Design stage. Then, prototype was developed in the Verify stage to conduct proof-of-concept testing. The results that obtained from each stage have been reported in this paper. From this study, it can be concluded that the application of Design for Six Sigma in designing a future portable water filter that uses membrane filtration system is a good start in looking for a new alternative concept with a completed supporting document.

Liquid aerosol filtration by fibrous filters in interception and inertial regimes; Filtration des aerosols liquides par les filtres a fibres en regimes d`interception et d`inertie

Energy Technology Data Exchange (ETDEWEB)

Gougeon, R

1994-09-26

In most previous studies of aerosol filtration, attention is focused on the maximum penetrating particle size region where the predominant mechanisms for collection are brownian diffusion and interception. In contrary the inertial regime remains poorly understood. Therefore, the aim of this study was to improve understanding of the behaviour of fibrous filters with liquid aerosols ar high frontal velocities both in the stationary and nonstationary filtration. Stationary filtration is first investigated. Experiments are done with special filters called `formettes` which have well defined structural characteristics. Precise results obtained with those filters allow us to select two relations quoted in the literature in order to describe the diffusion and the interception and to determine an empirical correlation describing the inertial impaction. Then this correlation with an industrial filter. In the second part, the evolution of the performances of fibrous filters loaded with liquid aerosols is studied experimentally and theoretically. We show that, in the inertial regime the filter efficiency first decreases and then increases rapidly with the loading rate. This increase is particularly important at high frontal velocities and with big particles. Macroscopic observations of high loaded filters show that the liquid is located in the fibre`s intersections to form big flat surfaces. A tentative of describing the evolution of the filter efficiency in modifying our stationary filtration model in order to take into account those liquid surfaces in the filter gives encouraging results. (authors). 92 refs., 93 figs., 11 tabs., 4 appends.

Modification of the TASMIP x-ray spectral model for the simulation of microfocus x-ray sources

Energy Technology Data Exchange (ETDEWEB)

Sisniega, A.; Vaquero, J. J., E-mail: juanjose.vaquero@uc3m.es [Departamento de Bioingeniería e Ingeniería Aeroespacial, Universidad Carlos III de Madrid, Madrid ES28911 (Spain); Instituto de Investigación Sanitaria Gregorio Marañón, Madrid ES28007 (Spain); Desco, M. [Departamento de Bioingeniería e Ingeniería Aeroespacial, Universidad Carlos III de Madrid, Madrid ES28911 (Spain); Instituto de Investigación Sanitaria Gregorio Marañón, Madrid ES28007 (Spain); Centro de Investigación Biomédica en Red de Salud Mental (CIBERSAM), Madrid ES28029 (Spain)

2014-01-15

Purpose: The availability of accurate and simple models for the estimation of x-ray spectra is of great importance for system simulation, optimization, or inclusion of photon energy information into data processing. There is a variety of publicly available tools for estimation of x-ray spectra in radiology and mammography. However, most of these models cannot be used directly for modeling microfocus x-ray sources due to differences in inherent filtration, energy range and/or anode material. For this reason the authors propose in this work a new model for the simulation of microfocus spectra based on existing models for mammography and radiology, modified to compensate for the effects of inherent filtration and energy range. Methods: The authors used the radiology and mammography versions of an existing empirical model [tungsten anode spectral model interpolating polynomials (TASMIP)] as the basis of the microfocus model. First, the authors estimated the inherent filtration included in the radiology model by comparing the shape of the spectra with spectra from the mammography model. Afterwards, the authors built a unified spectra dataset by combining both models and, finally, they estimated the parameters of the new version of TASMIP for microfocus sources by calibrating against experimental exposure data from a microfocus x-ray source. The model was validated by comparing estimated and experimental exposure and attenuation data for different attenuating materials and x-ray beam peak energy values, using two different x-ray tubes. Results: Inherent filtration for the radiology spectra from TASMIP was found to be equivalent to 1.68 mm Al, as compared to spectra obtained from the mammography model. To match the experimentally measured exposure data the combined dataset required to apply a negative filtration of about 0.21 mm Al and an anode roughness of 0.003 mm W. The validation of the model against real acquired data showed errors in exposure and attenuation in

Modification of the TASMIP x-ray spectral model for the simulation of microfocus x-ray sources

International Nuclear Information System (INIS)

Sisniega, A.; Vaquero, J. J.; Desco, M.

2014-01-01

Purpose: The availability of accurate and simple models for the estimation of x-ray spectra is of great importance for system simulation, optimization, or inclusion of photon energy information into data processing. There is a variety of publicly available tools for estimation of x-ray spectra in radiology and mammography. However, most of these models cannot be used directly for modeling microfocus x-ray sources due to differences in inherent filtration, energy range and/or anode material. For this reason the authors propose in this work a new model for the simulation of microfocus spectra based on existing models for mammography and radiology, modified to compensate for the effects of inherent filtration and energy range. Methods: The authors used the radiology and mammography versions of an existing empirical model [tungsten anode spectral model interpolating polynomials (TASMIP)] as the basis of the microfocus model. First, the authors estimated the inherent filtration included in the radiology model by comparing the shape of the spectra with spectra from the mammography model. Afterwards, the authors built a unified spectra dataset by combining both models and, finally, they estimated the parameters of the new version of TASMIP for microfocus sources by calibrating against experimental exposure data from a microfocus x-ray source. The model was validated by comparing estimated and experimental exposure and attenuation data for different attenuating materials and x-ray beam peak energy values, using two different x-ray tubes. Results: Inherent filtration for the radiology spectra from TASMIP was found to be equivalent to 1.68 mm Al, as compared to spectra obtained from the mammography model. To match the experimentally measured exposure data the combined dataset required to apply a negative filtration of about 0.21 mm Al and an anode roughness of 0.003 mm W. The validation of the model against real acquired data showed errors in exposure and attenuation in

Estimated glomerular filtration rate, chronic kidney disease and antiretroviral drug use in HIV-positive patients

DEFF Research Database (Denmark)

Mocroft, Amanda; Kirk, Ole; Reiss, Peter

2010-01-01

with at least three serum creatinine measurements and corresponding body weight measurements from 2004 onwards. METHODS:: CKD was defined as either confirmed (two measurements >/=3 months apart) estimated glomerular filtration rate (eGFR) of 60 ml/min per 1.73 m or below for persons with baseline eGFR of above...... cumulative exposure to tenofovir [incidence rate ratio (IRR) per year 1.16, 95% CI 1.06-1.25, P ... increased rate of CKD. Consistent results were observed in wide-ranging sensitivity analyses, although of marginal statistical significance for lopinavir/r. No other antiretroviral dugs were associated with increased incidence of CKD. CONCLUSION:: In this nonrandomized large cohort, increasing exposure...

Exploration Mission Particulate Matter Filtration Technology Performance Testing in a Simulated Spacecraft Cabin Ventilation System

Science.gov (United States)

Agui, Juan H.; Vijayakumar, R.; Perry, Jay L.; Frederick, Kenneth R.; Mccormick, Robert M.

2017-01-01

Human deep space exploration missions will require advances in long-life, low maintenance airborne particulate matter filtration technology. As one of the National Aeronautics and Space Administrations (NASA) developments in this area, a prototype of a new regenerable, multi-stage particulate matter filtration technology was tested in an International Space Station (ISS) module simulation facility. As previously reported, the key features of the filter system include inertial and media filtration with regeneration and in-place media replacement techniques. The testing facility can simulate aspects of the cabin environment aboard the ISS and contains flight-like cabin ventilation system components. The filtration technology test article was installed at the inlet of the central ventilation system duct and instrumented to provide performance data under nominal flow conditions. In-place regeneration operations were also evaluated. The real-time data included pressure drop across the filter stages, process air flow rate, ambient pressure, humidity and temperature. In addition, two video cameras positioned at the filtration technology test articles inlet and outlet were used to capture the mechanical performance of the filter media indexing operation under varying air flow rates. Recent test results are presented and future design recommendations are discussed.

Effect of Fusarium isolates and their filtrates on respiratory rate and chemical analysis of squash plants.

Science.gov (United States)

El-Shenawy, Z; Mansour, M A; El-Behrawi, S

1978-01-01

The highly pathogenic isolate stimulated the emergence of the squash seedlings first, caused, however, the highest death rate of the seedlings finally. Fusarium isolates and their culture filtrates inhibited the respiratory rate of squash plants significantly. However, F. oxysporum isolates inhibited respiration more than F. solani isolates. Seasonal changes of respiration decline show that the respiratory rate decreased with plant growth in the case of infested soil and of plants injected with culture filtrates. However, spraying Fusarium culture filtrates on the foliage gave opposite results when the plants grew older. Fusarium solani isolates decreased nitrogen content of squash stems and leaves, while F. oxysporum isolates gave reverse results. Injecting Fusarium culture filtrate into the plant decreased nitrogen content of both stems and leaves, while spraying the foliage with the filtrates increased nitrogen content more than that of the control. Phosphorus content of the stems of squash plants, sown in infested soil, was less than in the control when the plants were treated with F. solani and higher when they were treated with F. oxysporum isolates. On the other hand, the phosphorus content of squash leaves was higher than in the control. In the case of injected plants, however, the phosphorus content in stems and leaves was equal to that of the control or less, and with sprayed plants it was higher than in the control. Infesting the soil with Fusarium isolates and spraying the foliage with their culture filtrates increased potassium content of squash stems and leaves, while injecting the filtrates into the plants decreased potassium content of both stems and leaves.

Removal of heavy metals from aluminum anodic oxidation wastewaters by membrane filtration.

Science.gov (United States)

Ates, Nuray; Uzal, Nigmet

2018-05-27

Aluminum manufacturing has been reported as one of the largest industries and wastewater produced from the aluminum industry may cause significant environmental problems due to variable pH, high heavy metal concentration, conductivity, and organic load. The management of this wastewater with a high pollution load is of great importance for practitioners in the aluminum sector. There are hardly any studies available on membrane treatment of wastewater originated from anodic oxidation. The aim of this study is to evaluate the best treatment and reuse alternative for aluminum industry wastewater using membrane filtration. Additionally, the performance of chemical precipitation, which is the existing treatment used in the aluminum facility, was also compared with membrane filtration. Wastewater originated from anodic oxidation coating process of an aluminum profile manufacturing facility in Kayseri (Turkey) was used in the experiments. The characterization of raw wastewater was in very low pH (e.g., 3) with high aluminum concentration and conductivity values. Membrane experiments were carried out with ultrafiltration (PTUF), nanofiltration (NF270), and reverse osmosis (SW30) membranes with MWCO 5000, 200-400, and 100 Da, respectively. For the chemical precipitation experiments, FeCl 3 and FeSO 4 chemicals presented lower removal performances for aluminum and chromium, which were below 35% at ambient wastewater pH ~ 3. The membrane filtration experimental results show that, both NF and RO membranes tested could effectively remove aluminum, total chromium and nickel (>90%) from the aluminum production wastewater. The RO (SW30) membrane showed a slightly higher performance at 20 bar operating pressure in terms of conductivity removal values (90%) than the NF 270 membrane (87%). Although similar removal performances were observed for heavy metals and conductivity by NF270 and SW30, significantly higher fluxes were obtained in NF270 membrane filtration at any pressure

Sorption of polycyclic aromatic hydrocarbons (PAH) during the filtration of water samples

International Nuclear Information System (INIS)

Herbert, M.; Schueth, C.; Pyka, W.

1992-01-01

Filtration experiments were preformed for three selected polycyclic aromatic hydrocarbons (PAH-Fluorene, Fluoranthene and Benz(b)-fluoranthene) dissolved in water by varying filter materials, filter-pore sizes and filter equipment. The rate of recovery of PAH depended on the materials and methods applied. Organic filter materials showed a by far stronger sorption than inorganic materials. The losses for organic filters increased up to 100% with decreasing pore-size. The percentage loss was observed to increase with increasing octanol-water distribution coefficient (K OW ). Saturation tests revealed that the amount of water, necessary to saturate the filtration apparatus with and without filter-paper, also increased with the K OW . For BBF several liters would be necessary for saturation. It can be concluded, that the filtration of water samples, analysed for PAH, can lead to considerable errors in the analytical results, particularly for those PAH with log K OW larger than 5. (orig.)

A prospective study of glomerular filtration rate and arterial blood pressure in insulin-dependent diabetics with diabetic nephropathy

DEFF Research Database (Denmark)

Parving, H H; Smidt, U M; Friisberg, B

1981-01-01

Glomerular filtration rate (GFR, single bolus 51Cr-EDTA technique), serum creatinine, proteinuria and arterial blood pressure have been measured prospectively in 14 young onset insulin-dependent diabetics selected by of persistent proteinuria (greater than 0.5 g/day) secondary to diabetic...... in arterial blood pressure to a hypertensive level is an early feature of diabetic nephropathy in young insulin-dependent diabetics....... and 112/mumol/l (NS), proteinuria increased from 1.8 to 3.3 g/day (p less than 0.001) and arterial blood pressure rose from 132/88 to 153/101 mmHg (p less than 0.001). Glomerular filtration rate decreased linearly with time (slope = -0.75, r = 0.99, p less than 0.001) by a mean of 0.75 ml/min/month (range...

Plant-based assessment of inherent soil productivity and contributions to China's cereal crop yield increase since 1980.

Directory of Open Access Journals (Sweden)

Mingsheng Fan

Full Text Available OBJECTIVE: China's food production has increased 6-fold during the past half-century, thanks to increased yields resulting from the management intensification, accomplished through greater inputs of fertilizer, water, new crop strains, and other Green Revolution's technologies. Yet, changes in underlying quality of soils and their effects on yield increase remain to be determined. Here, we provide a first attempt to quantify historical changes in inherent soil productivity and their contributions to the increase in yield. METHODS: The assessment was conducted based on data-set derived from 7410 on-farm trials, 8 long-term experiments and an inventory of soil organic matter concentrations of arable land. RESULTS: Results show that even without organic and inorganic fertilizer addition crop yield from on-farm trials conducted in the 2000s was significantly higher compared with those in the 1980s - the increase ranged from 0.73 to 1.76 Mg/ha for China's major irrigated cereal-based cropping systems. The increase in on-farm yield in control plot since 1980s was due primarily to the enhancement of soil-related factors, and reflected inherent soil productivity improvement. The latter led to higher and stable yield with adoption of improved management practices, and contributed 43% to the increase in yield for wheat and 22% for maize in the north China, and, 31%, 35% and 22% for early and late rice in south China and for single rice crop in the Yangtze River Basin since 1980. CONCLUSIONS: Thus, without an improvement in inherent soil productivity, the 'Agricultural Miracle in China' would not have happened. A comprehensive strategy of inherent soil productivity improvement in China, accomplished through combining engineering-based measures with biological-approaches, may be an important lesson for the developing world. We propose that advancing food security in 21st century for both China and other parts of world will depend on continuously improving

Controlling inclusions through filtration in investment casting process

International Nuclear Information System (INIS)

Ahmad, R.; Marshall, R.I.

2004-01-01

A technique for the placement of a ceramic foam filter in the feeding up of investment mould was developed which proved quite efficient in removing smaller and major inclusions through various filtration modes. Contaminated old aluminum scrap was used to prepare the melt without the addition of any cleansing and covering fluxes and the main reason was to produce more and more inclusions. Vigorous stirring was also intentionally carried out to form as much oxides as possible. During present research work effective filtration was observed. No leakage through sides of the filter occurred and similarly no choking was seen during feeding of molten metal. Microstructural studies showed the maximum retention of inclusions not only on the surface of filters but also within the various channels of the main body of the filter. The microstructures taken from the filtered test pieces were free from inclusions, which showed the effectiveness and proper placement of the filter. (author)

Particle clogging in porous media. Filtration of a smectite solution

Energy Technology Data Exchange (ETDEWEB)

Richards, Tobias (Chalmers University of Technology, Goeteborg (Sweden))

2010-01-15