Enhanced performance of crumb rubber filtration for ballast water treatment.

PubMed

Tang, Zhijian; Butkus, Michael A; Xie, Yuefeng F

2009-03-01

Waste-tire-derived crumb rubber was utilized as filter media to develop an efficient filter for ballast water treatment. In this study, the effects of coagulation, pressure filtration and dual-media (gravity) filtration on the performance of the crumb rubber filtration were investigated. The removal efficiencies of turbidity, phytoplankton and zooplankton, and head loss development were monitored during the filtration process. The addition of a coagulant enhanced the removal efficiencies of all targeted matter, but resulted in substantial increase of head loss. Pressure filtration increased filtration rates to 220 m(3)h(-1)m(-2) for 8-h operation and improved the zooplankton removal. Dual-media (crumb rubber/sand) gravity filtration also improved the removal efficiencies of phytoplankton and zooplankton over mono-media gravity crumb rubber filtration. However, these filtration techniques alone did not meet the criteria for removing indigenous organisms from ballast water. A combination of filtration and disinfection is suggested for future studies.

Low-Dose CT of the Paranasal Sinuses: Minimizing X-Ray Exposure with Spectral Shaping.

PubMed

Wuest, Wolfgang; May, Matthias; Saake, Marc; Brand, Michael; Uder, Michael; Lell, Michael

2016-11-01

Shaping the energy spectrum of the X-ray beam has been shown to be beneficial in low-dose CT. This study's aim was to investigate dose and image quality of tin filtration at 100 kV for pre-operative planning in low-dose paranasal CT imaging in a large patient cohort. In a prospective trial, 129 patients were included. 64 patients were randomly assigned to the study protocol (100 kV with additional tin filtration, 150mAs, 192x0.6-mm slice collimation) and 65 patients to the standard low-dose protocol (100 kV, 50mAs, 128 × 0.6-mm slice collimation). To assess the image quality, subjective parameters were evaluated using a five-point scale. This scale was applied on overall image quality and contour delineation of critical anatomical structures. All scans were of diagnostic image quality. Bony structures were of good diagnostic image quality in both groups, soft tissues were of sufficient diagnostic image quality in the study group because of a high level of noise. Radiation exposure was very low in both groups, but significantly lower in the study group (CTDI vol 1.2 mGy vs. 4.4 mGy, p < 0.001). Spectral optimization (tin filtration at 100 kV) allows for visualization of the paranasal sinus with sufficient image quality at a very low radiation exposure. • Spectral optimization (tin filtration) is beneficial to low-dose parasinus CT • Tin filtration at 100 kV yields sufficient image quality for pre-operative planning • Diagnostic parasinus CT can be performed with an effective dose <0.05 mSv.

Influence of methane addition on selenium isotope sensitivity and their spectral interferences.

PubMed

Floor, Geerke H; Millot, Romain; Iglesias, Mónica; Négrel, Philippe

2011-02-01

The measurements of stable selenium (Se) isotopic signatures by multi-collector inductively coupled plasma mass spectrometry (MC-ICP-MS) are very challenging, due to the presence of spectral interferences and the low abundance of Se in environmental samples. We systematically investigated the effect of methane addition on the signal of Se isotopes and their interferences. It is the first time that the effect of methane addition has been assessed for all Se isotopes and its potential interferences using hydride generator multi-collector inductively coupled plasma mass spectrometry (HG-MC-ICP-MS). Our results show that a small methane addition increases the sensitivity. However, the response differs between a hydride generator and a standard introduction system, which might be related to differences in the ionization processes. Both argon and hydrogen-based interferences, the most common spectral interferences on selenium isotopes in HG-MC-ICP-MS, decrease with increasing methane addition. Therefore, analyte-interference ratios and precision are improved. Methane addition has thus a high potential for the application to stable Se isotopes ratios by HG-MC-ICP-MS. Copyright © 2011 John Wiley & Sons, Ltd.

8. OBLIQUE INTERIOR VIEW OF FILTRATION ROOM IN FILTRATION PLANT ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

8. OBLIQUE INTERIOR VIEW OF FILTRATION ROOM IN FILTRATION PLANT (#1773), LOOKING SOUTHWEST, SHOWING MEZZANINE WITH FILTER TANKS AT REAR - Presidio Water Treatment Plant, Filtration Plant, East of Lobos Creek at Baker Beach, San Francisco, San Francisco County, CA

7. OBLIQUE INTERIOR VIEW OF FILTRATION ROOM IN FILTRATION PLANT ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

7. OBLIQUE INTERIOR VIEW OF FILTRATION ROOM IN FILTRATION PLANT (#1773), LOOKING NORTHEAST, SHOWING PUMP NO. 1 AND METERING EQUIPMENT - Presidio Water Treatment Plant, Filtration Plant, East of Lobos Creek at Baker Beach, San Francisco, San Francisco County, CA

Rotary filtration system

DOEpatents

Herman, David T [Aiken, SC; Maxwell, David N [Aiken, SC

2011-04-19

A rotary filtration apparatus for filtering a feed fluid into permeate is provided. The rotary filtration apparatus includes a container that has a feed fluid inlet. A shaft is at least partially disposed in the container and has a passageway for the transport of permeate. A disk stack made of a plurality of filtration disks is mounted onto the shaft so that rotation of the shaft causes rotation of the filtration disks. The filtration disks may be made of steel components and may be welded together. The shaft may penetrate a filtering section of the container at a single location. The rotary filtration apparatus may also incorporate a bellows seal to prevent leakage along the shaft, and an around the shaft union rotary joint to allow for removal of permeate. Various components of the rotary filtration apparatus may be removed as a single assembly.

40 CFR 141.73 - Filtration.

Code of Federal Regulations, 2013 CFR

2013-07-01

... filtration. (1) For systems using diatomaceous earth filtration, the turbidity level of representative... PRIMARY DRINKING WATER REGULATIONS Filtration and Disinfection § 141.73 Filtration. A public water system... treatment or direct filtration. (1) For systems using conventional filtration or direct filtration, the...

40 CFR 141.73 - Filtration.

Code of Federal Regulations, 2011 CFR

2011-07-01

... filtration. (1) For systems using diatomaceous earth filtration, the turbidity level of representative... PRIMARY DRINKING WATER REGULATIONS Filtration and Disinfection § 141.73 Filtration. A public water system... treatment or direct filtration. (1) For systems using conventional filtration or direct filtration, the...

40 CFR 141.73 - Filtration.

Code of Federal Regulations, 2012 CFR

2012-07-01

... filtration. (1) For systems using diatomaceous earth filtration, the turbidity level of representative... PRIMARY DRINKING WATER REGULATIONS Filtration and Disinfection § 141.73 Filtration. A public water system... treatment or direct filtration. (1) For systems using conventional filtration or direct filtration, the...

Spectral Diffusion: An Algorithm for Robust Material Decomposition of Spectral CT Data

PubMed Central

Clark, Darin P.; Badea, Cristian T.

2014-01-01

Clinical successes with dual energy CT, aggressive development of energy discriminating x-ray detectors, and novel, target-specific, nanoparticle contrast agents promise to establish spectral CT as a powerful functional imaging modality. Common to all of these applications is the need for a material decomposition algorithm which is robust in the presence of noise. Here, we develop such an algorithm which uses spectrally joint, piece-wise constant kernel regression and the split Bregman method to iteratively solve for a material decomposition which is gradient sparse, quantitatively accurate, and minimally biased. We call this algorithm spectral diffusion because it integrates structural information from multiple spectral channels and their corresponding material decompositions within the framework of diffusion-like denoising algorithms (e.g. anisotropic diffusion, total variation, bilateral filtration). Using a 3D, digital bar phantom and a material sensitivity matrix calibrated for use with a polychromatic x-ray source, we quantify the limits of detectability (CNR = 5) afforded by spectral diffusion in the triple-energy material decomposition of iodine (3.1 mg/mL), gold (0.9 mg/mL), and gadolinium (2.9 mg/mL) concentrations. We then apply spectral diffusion to the in vivo separation of these three materials in the mouse kidneys, liver, and spleen. PMID:25296173

Spectral diffusion: an algorithm for robust material decomposition of spectral CT data.

PubMed

Clark, Darin P; Badea, Cristian T

2014-11-07

Clinical successes with dual energy CT, aggressive development of energy discriminating x-ray detectors, and novel, target-specific, nanoparticle contrast agents promise to establish spectral CT as a powerful functional imaging modality. Common to all of these applications is the need for a material decomposition algorithm which is robust in the presence of noise. Here, we develop such an algorithm which uses spectrally joint, piecewise constant kernel regression and the split Bregman method to iteratively solve for a material decomposition which is gradient sparse, quantitatively accurate, and minimally biased. We call this algorithm spectral diffusion because it integrates structural information from multiple spectral channels and their corresponding material decompositions within the framework of diffusion-like denoising algorithms (e.g. anisotropic diffusion, total variation, bilateral filtration). Using a 3D, digital bar phantom and a material sensitivity matrix calibrated for use with a polychromatic x-ray source, we quantify the limits of detectability (CNR = 5) afforded by spectral diffusion in the triple-energy material decomposition of iodine (3.1 mg mL(-1)), gold (0.9 mg mL(-1)), and gadolinium (2.9 mg mL(-1)) concentrations. We then apply spectral diffusion to the in vivo separation of these three materials in the mouse kidneys, liver, and spleen.

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

PubMed

Kartal, S N; Imamura, Y; Tsuchiya, F; Ohsato, K

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, Fomitopsis palustris. However the filtrates from sugi wood processed at 270 degrees 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.

Spectral filtering for plant production

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

Young, R.E.; McMahon, M.J.; Rajapakse, N.C.

1994-12-31

Research to date suggests that spectral filtering can be an effective alternative to chemical growth regulators for altering plant development. If properly implemented, it can be nonchemical and environmentally friendly. The aqueous CuSO{sub 4}, and CuCl{sub 2} solutions in channelled plastic panels have been shown to be effective filters, but they can be highly toxic if the solutions contact plants. Some studies suggest that spectral filtration limited to short EOD intervals can also alter plant development. Future research should be directed toward confirmation of the influence of spectral filters and exposure times on a broader range of plant species andmore » cultivars. Efforts should also be made to identify non-noxious alternatives to aqueous copper solutions and/or to incorporate these chemicals permanently into plastic films and panels that can be used in greenhouse construction. It would also be informative to study the impacts of spectral filters on insect and microbal populations in plant growth facilities. The economic impacts of spectral filtering techniques should be assessed for each delivery methodology.« less

40 CFR 141.173 - Filtration.

Code of Federal Regulations, 2014 CFR

2014-07-01

... treatment, direct filtration, slow sand filtration, or diatomaceous earth filtration. A public water system... 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...

40 CFR 141.173 - Filtration.

Code of Federal Regulations, 2011 CFR

2011-07-01

... treatment, direct filtration, slow sand filtration, or diatomaceous earth filtration. A public water system... 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...

40 CFR 141.173 - Filtration.

Code of Federal Regulations, 2013 CFR

2013-07-01

... treatment, direct filtration, slow sand filtration, or diatomaceous earth filtration. A public water system... 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...

40 CFR 141.173 - Filtration.

Code of Federal Regulations, 2012 CFR

2012-07-01

... treatment, direct filtration, slow sand filtration, or diatomaceous earth filtration. A public water system... 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...

Life Support Filtration System Trade Study for Deep Space Missions

NASA Technical Reports Server (NTRS)

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.

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

PubMed

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.

The Perspective of Riverbank Filtration in China

NASA Astrophysics Data System (ADS)

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

2014-12-01

. Additionally, the experience has demonstrated a number of water quality improvements associated with riverbank filtration. It is important to stress that the fate and behavior of emerging organic contaminants during riverbank filtration should be taken into special consideration.

Retrieval of the atmospheric compounds using a spectral optical thickness information

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

Ioltukhovski, A.A.

A spectral inversion technique for retrieval of the atmospheric gases and aerosols contents is proposed. This technique based upon the preliminary measurement or retrieval of the spectral optical thickness. The existence of a priori information about the spectral cross sections for some of the atmospheric components allows to retrieve the relative contents of these components in the atmosphere. Method of smooth filtration makes possible to estimate contents of atmospheric aerosols with known cross sections and to filter out other aerosols; this is done independently from their relative contribution to the optical thickness.

Validation of sterilizing grade filtration.

PubMed

Jornitz, M W; Meltzer, T H

2003-01-01

Validation consideration of sterilizing grade filters, namely 0.2 micron, changed when FDA voiced concerns about the validity of Bacterial Challenge tests performed in the past. Such validation exercises are nowadays considered to be filter qualification. Filter validation requires more thorough analysis, especially Bacterial Challenge testing with the actual drug product under process conditions. To do so, viability testing is a necessity to determine the Bacterial Challenge test methodology. Additionally to these two compulsory tests, other evaluations like extractable, adsorption and chemical compatibility tests should be considered. PDA Technical Report # 26, Sterilizing Filtration of Liquids, describes all parameters and aspects required for the comprehensive validation of filters. The report is a most helpful tool for validation of liquid filters used in the biopharmaceutical industry. It sets the cornerstones of validation requirements and other filtration considerations.

Organic colloids and their influence on low-pressure membrane filtration.

PubMed

Laabs, C; Amy, G; Jekel, M

2004-01-01

Wastewater treatment by low-pressure membrane filtration (MF and UF) is affected to a large extent by macromolecules and colloids. In order to investigate the influence of organic colloids on the membrane filtration process, colloids were isolated from a wastewater treatment plant effluent using a rotary-evaporation pre-concentration step followed by dialysis. Stirred cell tests were carried out using redissolved colloids, with and without additional glass fiber filtration. After constant pressure membrane filtration of 190 L/m2, the initial flux had declined by 50% for colloids > 6-8 kD (glass fiber filtered) with a hydrophilic MF membrane and for colloids > 12-14 kD (glass fiber filtered) with a hydrophobic MF membrane. For the non-filtered colloidal solutions, the flux decline was even steeper with the flux being below 10% of the initial flux after 190 L/m2 were passed through the membranes. As with larger particles, colloids form a filtration cake layer on top of the membrane surface when used as isolates without prior filtration. This filtration cake is easily removed during backwashing. However, polysaccharides as a macromolecular component of the colloid isolate cause severe fouling by the formation of a gel layer on the membrane surface that is difficult to remove completely.

Rapid Detection of Pathogenic Bacteria from Fresh Produce by Filtration and Surface-Enhanced Raman Spectroscopy

NASA Astrophysics Data System (ADS)

Wu, Xiaomeng; Han, Caiqin; Chen, Jing; Huang, Yao-Wen; Zhao, Yiping

2016-04-01

The detection of Salmonella Poona from cantaloupe cubes and E. coli O157:H7 from lettuce has been explored by using a filtration method and surface-enhanced Raman spectroscopy (SERS) based on vancomycin-functionalized silver nanorod array substrates. It is found that with a two-step filtration process, the limit of detection (LOD) of Salmonella Poona from cantaloupe cubes can be as low as 100 CFU/mL in less than 4 h, whereas the chlorophyll in the lettuce causes severe SERS spectral interference. To improve the LOD of lettuce, a three-step filtration method with a hydrophobic filter is proposed. The hydrophobic filter can effectively eliminate the interferences from chlorophyll and achieve a LOD of 1000 CFU/mL detection of E. coli O157:H7 from lettuce samples within 5 h. With the low LODs and rapid detection time, the SERS biosensing platform has demonstrated its potential as a rapid, simple, and inexpensive means for pathogenic bacteria detection from fresh produce.

Ultrasonic filtration of industrial chemical solutions

NASA Technical Reports Server (NTRS)

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.

Filtration Efficiency of Functionalized Ceramic Foam Filters for Aluminum Melt Filtration

NASA Astrophysics Data System (ADS)

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.

Gel filtration of sialoglycoproteins.

PubMed Central

Alhadeff, J A

1978-01-01

The role of sialic acid in the gel-filtration behaviour of sialoglycoproteins was investigated by using the separated isoenzymes of purified human liver alpha-L-fucosidase and several other well-known sialic acid-containing glycoproteins (fetuin, alpha1-acid glycoprotein, thyroglobulin and bovine submaxillary mucin). For each glycoprotein studied, gel filtration of its desialylated derivative gave an apparent molecular weights much less than that expected just from removal of sialic acid. For the lower-molecular-weight glycoproteins (fetuin and alpha1-acid glyocprotein), gel filtration of the sialylated molecules led to apparent molecular weights much larger than the known values. The data indicate that gel filtration cannot be used for accurately determining the molecular weights of at least some sialoglycoproteins. Images Fig. 1. PMID:356853

Public health protection through bank filtration - Kearney Nebraska case study

NASA Astrophysics Data System (ADS)

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

2003-04-01

results of an additional 12-month study. Additional monitoring took place from October 1997 to October 1998. Results of the second study supported the findings of the original 18-week study. The Department finalized approval of the removal credits on December 16, 1999. This paper discusses the 2 studies, ongoing monitoring, decisions made by the Department, and issues the City and the Department have addressed and will be addressing with the addition of new treatment requirements to surface water treatment rules. In addition, this paper examines features of the Island wellfield that may explain the documented bank filtration treatment efficiencies.

Automated in-line gel filtration for native state mass spectrometry.

PubMed

Waitt, Greg M; Xu, Robert; Wisely, G Bruce; Williams, Jon D

2008-02-01

Characterization of protein-ligand complexes by nondenaturing mass spectrometry provides direct evidence of drug-like molecules binding with potential therapeutic targets. Typically, protein-ligand complexes to be analyzed contain buffer salts, detergents, and other additives to enhance protein solubility, all of which make the sample unable to be analyzed directly by electrospray ionization mass spectrometry. This work describes an in-line gel-filtration method that has been automated and optimized. Automation was achieved using commercial HPLC equipment. Gel column parameters that were optimized include: column dimensions, flow rate, packing material type, particle size, and molecular weight cut-off. Under optimal conditions, desalted protein ions are detected 4 min after injection and the analysis is completed in 20 min. The gel column retains good performance even after >200 injections. A demonstration for using the in-line gel-filtration system is shown for monitoring the exchange of fatty acids from the pocket of a nuclear hormone receptor, peroxisome proliferator activator-delta (PPARdelta) with a tool compound. Additional utilities of in-line gel-filtration mass spectrometry system will also be discussed.

Mitigation of radon and thoron decay products by filtration.

PubMed

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

2011-09-01

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 thoron

Emissions from a Diesel Engine using Fe-based Fuel Additives and a Sintered Metal Filtration System.

PubMed

Bugarski, Aleksandar D; Hummer, Jon A; Stachulak, Jozef S; Miller, Arthur; Patts, Larry D; Cauda, Emanuele G

2016-03-01

A series of laboratory tests were conducted to assess the effects of Fe-containing fuel additives on aerosols emitted by a diesel engine retrofitted with a sintered metal filter (SMF) system. Emission measurements performed upstream and downstream of the SMF system were compared, for cases when the engine was fueled with neat ultralow sulfur diesel (ULSD) and with ULSD treated with two formulations of additives containing Fe-based catalysts. The effects were assessed for four steady-state engine operating conditions and one transient cycle. The results showed that the SMF system reduced the average total number and surface area concentrations of aerosols by more than 100-fold. The total mass and elemental carbon results confirmed that the SMF system was indeed very effective in the removal of diesel aerosols. When added at the recommended concentrations (30 p.p.m. of iron), the tested additives had minor adverse impacts on the number, surface area, and mass concentrations of filter-out (FOut) aerosols. For one of the test cases, the additives may have contributed to measurable concentrations of engine-out (EOut) nucleation mode aerosols. The additives had only a minor impact on the concentration and size distribution of volatile and semi-volatile FOut aerosols. Metal analysis showed that the introduction of Fe with the additives substantially increased Fe concentration in the EOut, but the SMF system was effective in removal of Fe-containing aerosols. The FOut Fe concentrations for all three tested fuels were found to be much lower than the corresponding EOut Fe concentrations for the case of untreated ULSD fuel. The results support recommendations that these additives should not be used in diesel engines unless they are equipped with exhaust filtration systems. Since the tested SMF system was found to be very efficient in removing Fe introduced by the additives, the use of these additives should not result in a measurable increase in emissions of de novo generated

Emissions from a Diesel Engine using Fe-based Fuel Additives and a Sintered Metal Filtration System

PubMed Central

Bugarski, Aleksandar D.; Hummer, Jon A.; Stachulak, Jozef S.; Miller, Arthur; Patts, Larry D.; Cauda, Emanuele G.

2015-01-01

A series of laboratory tests were conducted to assess the effects of Fe-containing fuel additives on aerosols emitted by a diesel engine retrofitted with a sintered metal filter (SMF) system. Emission measurements performed upstream and downstream of the SMF system were compared, for cases when the engine was fueled with neat ultralow sulfur diesel (ULSD) and with ULSD treated with two formulations of additives containing Fe-based catalysts. The effects were assessed for four steady-state engine operating conditions and one transient cycle. The results showed that the SMF system reduced the average total number and surface area concentrations of aerosols by more than 100-fold. The total mass and elemental carbon results confirmed that the SMF system was indeed very effective in the removal of diesel aerosols. When added at the recommended concentrations (30 p.p.m. of iron), the tested additives had minor adverse impacts on the number, surface area, and mass concentrations of filter-out (FOut) aerosols. For one of the test cases, the additives may have contributed to measurable concentrations of engine-out (EOut) nucleation mode aerosols. The additives had only a minor impact on the concentration and size distribution of volatile and semi-volatile FOut aerosols. Metal analysis showed that the introduction of Fe with the additives substantially increased Fe concentration in the EOut, but the SMF system was effective in removal of Fe-containing aerosols. The FOut Fe concentrations for all three tested fuels were found to be much lower than the corresponding EOut Fe concentrations for the case of untreated ULSD fuel. The results support recommendations that these additives should not be used in diesel engines unless they are equipped with exhaust filtration systems. Since the tested SMF system was found to be very efficient in removing Fe introduced by the additives, the use of these additives should not result in a measurable increase in emissions of de novo generated

Simultaneous masking additivity for short Gaussian-shaped tones: spectral effects.

PubMed

Laback, Bernhard; Necciari, Thibaud; Balazs, Peter; Savel, Sophie; Ystad, Sølvi

2013-08-01

Laback et al. [(2011). J. Acoust. Soc. Am. 129, 888-897] investigated the additivity of nonsimultaneous masking using short Gaussian-shaped tones as maskers and target. The present study involved Gaussian stimuli to measure the additivity of simultaneous masking for combinations of up to four spectrally separated maskers. According to most basilar membrane measurements, the maskers should be processed linearly at the characteristic frequency (CF) of the target. Assuming also compression of the target, all masker combinations should produce excess masking (exceeding linear additivity). The results for a pair of maskers flanking the target indeed showed excess masking. The amount of excess masking could be predicted by a model assuming summation of masker-evoked excitations in intensity units at the target CF and compression of the target, using compressive input/output functions derived from the nonsimultaneous masking study. However, the combinations of lower-frequency maskers showed much less excess masking than predicted by the model. This cannot easily be attributed to factors like off-frequency listening, combination tone perception, or between-masker suppression. It was better predicted, however, by assuming weighted intensity summation of masker excitations. The optimum weights for the lower-frequency maskers were smaller than one, consistent with partial masker compression as indicated by recent psychoacoustic data.

Removals of cryptosporidium parvum oocysts and cryptosporidium-sized polystyrene microspheres from swimming pool water by diatomaceous earth filtration and perlite-sand filtration.

PubMed

Lu, Ping; Amburgey, James E; Hill, Vincent R; Murphy, Jennifer L; Schneeberger, Chandra L; Arrowood, Michael J; Yuan, Tao

2017-06-01

Removal of Cryptosporidium-sized microspheres and Cryptosporidium parvum oocysts from swimming pools was investigated using diatomaceous earth (DE) precoat filtration and perlite-sand filtration. In pilot-scale experiments, microsphere removals of up to 2 log were obtained with 0.7 kg·DE/m 2 at a filtration rate of 5 m/h. A slightly higher microsphere removal (2.3 log) was obtained for these DE-precoated filters when the filtration rate was 3.6 m/h. Additionally, pilot-scale perlite-sand filters achieved greater than 2 log removal when at least 0.37 kg/m 2 of perlite was used compared to 0.1-0.4 log removal without perlite both at a surface loading rate of 37 m/h. Full-scale testing achieved 2.7 log of microspheres and oocysts removal when 0.7 kg·DE/m 2 was used at 3.6 m/h. Removals were significantly decreased by a 15-minute interruption of the flow (without any mechanical agitation) to the DE filter in pilot-scale studies, which was not observed in full-scale filters. Microsphere removals were 2.7 log by perlite-sand filtration in a full-scale swimming pool filter operated at 34 m/h with 0.5 kg/m 2 of perlite. The results demonstrate that either a DE precoat filter or a perlite-sand filter can improve the efficiency of removal of microspheres and oocysts from swimming pools over a standard sand filter under the conditions studied.

Water Filtration Products

NASA Technical Reports Server (NTRS)

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.

WATER FILTRATION AT DULUTH

EPA Science Inventory

After partial completion of the Lakewood Filtration Plant at Duluth, studies were begun with funding provided by the demonstration grant. Research covered a variety of topics and was done with a 10 gpm pilot plant located at the filtration plant, with the full scale plant operati...

On the equivalence of some spectral sequences for Serre fibrations

NASA Astrophysics Data System (ADS)

Onishchenko, Aleksandr Yu; Popelenskii, Fedor Yu

2011-04-01

Several different constructions of a spectral sequence for a Serre fibration \\pi\\colon E \\to B over a compact simply connected manifold B are considered in this paper. Namely, we consider the spectral sequence for the minimal model (\\Lambda V\\otimes \\Lambda W,d) of the fibration, along with the spectral sequences arising from the Čech filtration in the complexes \\check{C}^*(\\mathscr{U}, A_{PL}^*(\\pi^{-1}(U))) and \\check{C}^*(\\mathscr{U}, S^*(\\pi^{-1}(U))), where \\mathscr{U}=\\{U\\} is a covering of the base B. It is known that all these spectral sequences have the same terms E_2^{*,*}=H^*(X)\\otimes H^*(F) and converge to the cohomology of the total space E. A new natural isomorphism of these spectral sequences is constructed in every term E_r with r\\ge2. It is also proved that in the case of a smooth locally trivial fibration these spectral sequences are isomorphic to the spectral sequences of the complex of smooth forms \\Omega^*(E) and of the Čech-de Rham complex. It is therefore established that all these constructions give the same spectral sequence, starting from the E_2 term. Bibliography: 9 titles.

PDF-based heterogeneous multiscale filtration model.

PubMed

Gong, Jian; Rutland, Christopher J

2015-04-21

Motivated by modeling of gasoline particulate filters (GPFs), a probability density function (PDF) based heterogeneous multiscale filtration (HMF) model is developed to calculate filtration efficiency of clean particulate filters. A new methodology based on statistical theory and classic filtration theory is developed in the HMF model. Based on the analysis of experimental porosimetry data, a pore size probability density function is introduced to represent heterogeneity and multiscale characteristics of the porous wall. The filtration efficiency of a filter can be calculated as the sum of the contributions of individual collectors. The resulting HMF model overcomes the limitations of classic mean filtration models which rely on tuning of the mean collector size. Sensitivity analysis shows that the HMF model recovers the classical mean model when the pore size variance is very small. The HMF model is validated by fundamental filtration experimental data from different scales of filter samples. The model shows a good agreement with experimental data at various operating conditions. The effects of the microstructure of filters on filtration efficiency as well as the most penetrating particle size are correctly predicted by the model.

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

NASA Astrophysics Data System (ADS)

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.

Polyethersulfone/polyacrylonitrile blended ultrafiltration membranes: preparation, morphology and filtration properties.

PubMed

Pasaoglu, Mehmet Emin; Guclu, Serkan; Koyuncu, Ismail

Polyethersulfone (PES)/polyacrylonitrile (PAN) membranes have been paid attention among membrane research subjects. However, very few studies are included in the literature. In our study, asymmetric ultrafiltration (UF) membranes were prepared from blends of PES/PAN with phase inversion method using water as coagulation bath. Polyvinylpyrrolidone (PVP) with Mw of 10,000 Da was used as pore former agent. N,N-dimethylformamide was used as solvent. The effects of different percentage of PVP and PES/PAN composition on morphology and water filtration properties were investigated. Membrane performances were examined using pure water and lake water filtration studies. Performances of pure water were less with the addition of PAN into the PES polymer casting solutions. However, long-term water filtration tests showed that PES/PAN blend membranes anti-fouling properties were much higher than the neat PES membranes. The contact angles of PES/PAN membranes were lower than neat PES membranes because of PAN addition in PES polymer casting solutions. Furthermore, it was found that PES/PAN blend UF membranes' dynamic mechanical analysis properties in terms of Young's modules were less than neat PES membrane because of decreasing amount of PES polymer.

Comparison of Dilution, Filtration, and Microwave Digestion Sample Pretreatments in Elemental Profiling of Wine by ICP-MS.

PubMed

Godshaw, Joshua; Hopfer, Helene; Nelson, Jenny; Ebeler, Susan E

2017-09-25

Wine elemental composition varies by cultivar, geographic origin, viticultural and enological practices, and is often used for authenticity validation. Elemental analysis of wine by Inductively Coupled Plasma Mass Spectrometry (ICP-MS) is challenging due to the potential for non-spectral interferences and plasma instability arising from organic matrix components. Sample preparation mitigates these interferences, however, conflicting recommendations of best practices in ICP-MS analysis of wine have been reported. This study compared direct dilution, microwave-assisted acid digestion, and two filtration sample pretreatments, acidification prior to filtration and filtration followed by acidification, in elemental profiling of one white and three red table wines by ICP-MS. Of 43 monitored isotopes, 37 varied by sample preparation method, with significantly higher results of 17 isotopes in the microwave-digested samples. Both filtration treatments resulted in lower results for 11 isotopes compared to the other methods. Finally, isotope dilution determination of copper based on natural abundances and the 63 Cu: 65 Cu instrument response ratio agreed with external calibration and confirmed a significant sample preparation effect. Overall, microwave digestion did not compare favorably, and direct dilution was found to provide the best compromise between ease of use and result accuracy and precision, although all preparation strategies were able to differentiate the wines.

Health benefits of particle filtration.

PubMed

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.

Pig manure treatment by filtration.

PubMed

Kowalski, Zygmunt; Makara, Agnieszka; Matýsek, Dalibor; Hoffmann, Józef; Hoffmann, Krystyna

2013-01-01

A study of new pig manure treatment and filtration process was carried out. The advantage of the worked out technology is the method of incorporation of crystalline phase into solid organic part of manure. The obtained new solid phase of manure contains about 50% of crystalline phase forming a filtration aid that enables high effectiveness of manure filtration. The filtration rate of manure separation into solid and liquid fractions with pressure filter may achieve 1300-3000 kg/m(2)/h. The method makes it possible to maintain an overall average pollutant removal performance 90% for the chemical oxygen demand COD, > 99% for the suspended solids SS, to 47% for the total nitrogen content. The obtained results showed that the proposed technology being efficient and simple offers a possible solution to pig manure problems.

Microfluidic colloid filtration

PubMed Central

Linkhorst, John; Beckmann, Torsten; Go, Dennis; Kuehne, Alexander J. C.; Wessling, Matthias

2016-01-01

Filtration of natural and colloidal matter is an essential process in today’s water treatment processes. The colloidal matter is retained with the help of micro- and nanoporous synthetic membranes. Colloids are retained in a “cake layer” – often coined fouling layer. Membrane fouling is the most substantial problem in membrane filtration: colloidal and natural matter build-up leads to an increasing resistance and thus decreasing water transport rate through the membrane. Theoretical models exist to describe macroscopically the hydrodynamic resistance of such transport and rejection phenomena; however, visualization of the various phenomena occurring during colloid retention is extremely demanding. Here we present a microfluidics based methodology to follow filter cake build up as well as transport phenomena occuring inside of the fouling layer. The microfluidic colloidal filtration methodology enables the study of complex colloidal jamming, crystallization and melting processes as well as translocation at the single particle level. PMID:26927706

Spectral gamuts and spectral gamut mapping

NASA Astrophysics Data System (ADS)

Rosen, Mitchell R.; Derhak, Maxim W.

2006-01-01

All imaging devices have two gamuts: the stimulus gamut and the response gamut. The response gamut of a print engine is typically described in CIE colorimetry units, a system derived to quantify human color response. More fundamental than colorimetric gamuts are spectral gamuts, based on radiance, reflectance or transmittance units. Spectral gamuts depend on the physics of light or on how materials interact with light and do not involve the human's photoreceptor integration or brain processing. Methods for visualizing a spectral gamut raise challenges as do considerations of how to utilize such a data-set for producing superior color reproductions. Recent work has described a transformation of spectra reduced to 6-dimensions called LabPQR. LabPQR was designed as a hybrid space with three explicit colorimetric axes and three additional spectral reconstruction axes. In this paper spectral gamuts are discussed making use of LabPQR. Also, spectral gamut mapping is considered in light of the colorimetric-spectral duality of the LabPQR space.

Purification of Hemoglobin by Tangential Flow Filtration with Diafiltration

PubMed Central

Elmer, Jacob; Harris, David R.; Sun, Guoyong; Palmer, Andre F.

2009-01-01

A recent study by Palmer et al. (2009) demonstrated that tangential flow filtration (TFF) can be used to produce HPLC-grade bovine and human hemoglobin (Hb). In this current study, we assessed the quality of bovine Hb (bHb) purified by introducing a 10 L batch-mode diafiltration step to the previously mentioned TFF Hb purification process. bHb was purified from bovine red blood cells (RBCs) by filtering clarified RBC lysate through 50 nm (stage I) & 500 kDa (stage II) hollow fiber (HF) membranes. The filtrate was then passed through a 100 kDa (stage III) HF membrane with or without an additional 10 L diafiltration step to potentially remove additional small molecular weight impurities. Protein assays, SDS-PAGE, and LC-MS of the purified bHb (stage III retentate) reveal that addition of a diafiltration step has no effect on bHb purity or yield; however, it does increase the methemoglobin level and oxygen affinity of purified bHb. Therefore, we conclude that no additional benefit is gained from diafiltration at stage III and a three-stage TFF process is sufficient to produce HPLC-grade bHb. PMID:19621471

On the equivalence of some spectral sequences for Serre fibrations

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

Onishchenko, Aleksandr Yu; Popelenskii, Fedor Yu

2011-04-30

Several different constructions of a spectral sequence for a Serre fibration {pi}:E{yields}B over a compact simply connected manifold B are considered in this paper. Namely, we consider the spectral sequence for the minimal model ({Lambda}Vx{Lambda}W,d) of the fibration, along with the spectral sequences arising from the Cech filtration in the complexes C*(U,A*{sub PL}({pi}{sup -1}(U))) and C*(U,S*({pi}{sup -1}(U))), where U=(U) is a covering of the base B. It is known that all these spectral sequences have the same terms E{sub 2}*{sup ,}*=H*(X)xH{sup *}(F) and converge to the cohomology of the total space E. A new natural isomorphism of these spectral sequencesmore » is constructed in every term E{sub r} with r{>=}2. It is also proved that in the case of a smooth locally trivial fibration these spectral sequences are isomorphic to the spectral sequences of the complex of smooth forms {Omega}*(E) and of the Cech-de Rham complex. It is therefore established that all these constructions give the same spectral sequence, starting from the E{sub 2} term. Bibliography: 9 titles.« less

40 CFR 141.173 - Filtration.

Code of Federal Regulations, 2010 CFR

2010-07-01

... Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) WATER PROGRAMS (CONTINUED) NATIONAL 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...

Water sample filtration unit

USGS Publications Warehouse

Skougstad, M.W.; Scarbro, G.F.

1968-01-01

A readily portable, all plastic, pressure filtration unit is described which greatly facilitates rapid micropore membrane field filtration of up to several liters of water with a minimum risk of inorganic chemical alteration or contamination of the sample. The unit accommodates standard 10.2-cm. (4-inch) diameter filters. The storage and carrying case serves as a convenient filter stand for both field and laboratory use.

40 CFR 141.73 - Filtration.

Code of Federal Regulations, 2010 CFR

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...

Environmental Technology Verification--Baghouse Filtration Products: GE Energy QG061 Filtration Media (Tested September 2008)

EPA Science Inventory

This report reviews the filtration and pressure drop performance of GE Energy's QG061 filtration media. Environmental Technology Verification (ETV) testing of this technology/product was conducted during a series of tests in September 2008. The objective of the ETV Program is to ...

A PERSPECTIVE OF RIVERBANK FILTRATION

EPA Science Inventory

Riverbank filtration is a process in which pumping of wells located along riverbanks induce a portion of the river water to flow toward the pumping wells. The process has many similarities to the slow sand filtration process. River water contaminants are attenuated due to a combi...

Spectral Analysis: From Additive Perspective to Multiplicative Perspective

NASA Astrophysics Data System (ADS)

Wu, Z.

2017-12-01

The early usage of trigonometric functions can be traced back to at least 17th century BC. It was Bhaskara II of the 12th century CE who first proved the mathematical equivalence between the sum of two trigonometric functions of any given angles and the product of two trigonometric functions of related angles, which has been taught these days in middle school classroom. The additive perspective of trigonometric functions led to the development of the Fourier transform that is used to express any functions as the sum of a set of trigonometric functions and opened a new mathematical field called harmonic analysis. Unfortunately, Fourier's sum cannot directly express nonlinear interactions between trigonometric components of different periods, and thereby lacking the capability of quantifying nonlinear interactions in dynamical systems. In this talk, the speaker will introduce the Huang transform and Holo-spectrum which were pioneered by Norden Huang and emphasizes the multiplicative perspective of trigonometric functions in expressing any function. Holo-spectrum is a multi-dimensional spectral expression of a time series that explicitly identifies the interactions among different scales and quantifies nonlinear interactions hidden in a time series. Along with this introduction, the developing concepts of physical, rather than mathematical, analysis of data will be explained. Various enlightening applications of Holo-spectrum analysis in atmospheric and climate studies will also be presented.

Filtration by eyelashes

NASA Astrophysics Data System (ADS)

Vistarakula, Krishna; Bergin, Mike; Hu, David

2010-11-01

Nearly every mammalian and avian eye is rimmed with lashes. We investigate experimentally the ability of lashes to reduce airborne particle deposition in the eye. We hypothesize that there is an optimum eyelash length that maximizes both filtration ability and extent of peripheral vision. This hypothesis is tested using a dual approach. Using preserved heads from 36 species of animals at the American Museum of Natural History, we determine the relationship between eye size and eyelash geometry (length and spacing). We test the filtration efficacy of these geometries by deploying outdoor manikins and measuring particle deposition rate as a function of eyelash length.

COMPARATIVE EVALUATION OF R3f GARNET BEAD FILTRATION AND MULTIMEDIA FILTRATION SYSTEMS; FINAL REPORT

EPA Science Inventory

This report summarizes the results of tests conducted to date at the EPA T&E Facility on the R3f filtration system utilizing fine beads (such as garnet beads or glass beads) and a conventional multimedia filtration system. Both systems have been designed and built by Enprotec, a...

Sterile Filtration of Highly Concentrated Protein Formulations: Impact of Protein Concentration, Formulation Composition, and Filter Material.

PubMed

Allmendinger, Andrea; Mueller, Robert; Huwyler, Joerg; Mahler, Hanns-Christian; Fischer, Stefan

2015-10-01

Differences in filtration behavior of concentrated protein formulations were observed during aseptic drug product manufacturing of biologics dependent on formulation composition. The present study investigates filtration forces of monoclonal antibody formulations in a small-scale set-up using polyvinylidene difluoride (PVDF) or polyethersulfone (PES) filters. Different factors like formulation composition and protein concentration related to differences in viscosity, as well as different filtration rates were evaluated. The present study showed that filtration behavior was influenced by the presence or absence of a surfactant in the formulation, which defines the interaction between filter membrane and surface active formulation components. This can lead to a change in filter resistance (PES filter) independent on the buffer system used. Filtration behavior was additionally defined by rheological non-Newtonian flow behavior. The data showed that high shear rates resulting from small pore sizes and filtration pressure up to 1.0 bar led to shear-thinning behavior for highly concentrated protein formulations. Differences in non-Newtonian behavior were attributed to ionic strength related to differences in repulsive and attractive interactions. The present study showed that the interplay of formulation composition, filter material, and filtration rate can explain differences in filtration behavior/filtration flux observed for highly concentrated protein formulations thus guiding filter selection. © 2015 Wiley Periodicals, Inc. and the American Pharmacists Association.

Removal of Cryptosporidium parvum in bank filtration systems

NASA Astrophysics Data System (ADS)

Harter, T.; Atwill, E. R.; Hou, L. L.

2003-04-01

The protozoan pathogen Cryptosporidium parvum is a leading cause of waterborne disease. Many surface water systems therefore depend on filtration systems, including bank filtration systems, for the removal of the pathogenic oocysts. To better understand the effectiveness, e.g., of bank filtration systems, we have implemented a series of columns studies under various environmental conditions (column length: 10 cm - 60 cm, flow rates: 0.7 m/d - 30 m/d, ionic strength: 0.01 - 100 mM, filter grain size: 0.2 - 2 mm, various solution chemistry). We show that classic colloid filtration theory is a reasonable tool for predicting the initial breakthrough of C. parvum in pulsed injections of the oocyst through sand columns, although the model does not account for the significant tailing that occurs in C. parvum transport. Application of colloid filtration theory to bank filtration system is further limited by the intrinsic heterogeneity of the geologic systems used for bank filtration. We couple filtration theory with a stochastic subsurface transport approach and with percolation theory to account for the effects of intrinsic heterogeneity. We find that a 1-log removal can be achieved even under relatively adverse conditions (low collision efficiency, high velocity) if 85% - 90% of the sedimentary hydrofacies located within the bank filtration system or of the coarsest known hydrofacies connecting the riverbed with the extraction system has a grain-size distribution with a 10% passing diameter equal to 1 mm. One millimeter is a standard sieve size in sediment analysis.

Biophysical analysis of water filtration phenomenon in the roots of halophytes

NASA Astrophysics Data System (ADS)

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).

Vibrating membrane filtration as improved technology for microalgae dewatering.

PubMed

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.

Effect of hypothermic pulmonary artery flushing on capillary filtration coefficient.

PubMed

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

Impact of backwashing procedures on deep bed filtration productivity in drinking water treatment.

PubMed

Slavik, Irene; Jehmlich, Alexander; Uhl, Wolfgang

2013-10-15

Backwash procedures for deep bed filters were evaluated and compared by means of a new integrated approach based on productivity. For this, different backwash procedures were experimentally evaluated by using a pilot plant for direct filtration. A standard backwash mode as applied in practice served as a reference and effluent turbidity was used as the criterion for filter run termination. The backwash water volumes needed, duration of the filter-to-waste period, time out of operation, total volume discharged and filter run-time were determined and used to calculate average filtration velocity and average productivity. Results for filter run-times, filter backwash volumes, and filter-to-waste volumes showed considerable differences between the backwash procedures. Thus, backwash procedures with additional clear flushing phases were characterised by an increased need for backwash water. However, this additional water consumption could not be compensated by savings during filter ripening. Compared to the reference backwash procedure, filter run-times were longer for both single-media and dual-media filters when air scour and air/water flush were optimised with respect to flow rates and the proportion of air and water. This means that drinking water production time is longer and less water is needed for filter bed cleaning. Also, backwashing with additional clear flushing phases resulted in longer filter run-times before turbidity breakthrough. However, regarding the productivity of the filtration process, it was shown that it was almost the same for all of the backwash procedures investigated in this study. Due to this unexpected finding, the relationships between filter bed cleaning, filter ripening and filtration performance were considered and important conclusions and new approaches for process optimisation and resource savings were derived. Copyright © 2013 Elsevier Ltd. All rights reserved.

Harvesting microalgal biomass using crossflow membrane filtration: critical flux, filtration performance, and fouling characterization.

PubMed

Elcik, Harun; Cakmakci, Mehmet

2017-06-01

The purpose of this study was to investigate the efficient harvesting of microalgal biomass through crossflow membrane filtration. The microalgal biomass harvesting experiments were performed using one microfiltration membrane (pore size: 0.2 µm, made from polyvinylidene fluoride) and three ultrafiltration membranes (molecular weight cut-off: 150, 50, and 30 kDa, made from polyethersulfone, hydrophilic polyethersulfone, and regenerated cellulose, respectively). Initially, to minimize membrane fouling caused by microalgal cells, experiments with the objective of determining the critical flux were performed. Based on the critical flux calculations, the best performing membrane was confirmed to be the UH050 membrane, produced from hydrophilic polyethersulfone material. Furthermore, we also evaluated the effect of transmembrane pressure (TMP) and crossflow velocity (CFV) on filtration flux. It was observed that membrane fouling was affected not only by the membrane characteristics, but also by the TMP and CFV. In all the membranes, it was observed that increasing CFV was associated with increasing filtration flux, independent of the TMP.

Exploration Mission Particulate Matter Filtration Technology Performance Testing in a Simulated Spacecraft Cabin Ventilation System

NASA Technical Reports Server (NTRS)

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.

40 CFR 141.174 - Filtration sampling requirements.

Code of Federal Regulations, 2012 CFR

2012-07-01

....174 Section 141.174 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) WATER 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 CFR 141.174 - Filtration sampling requirements.

Code of Federal Regulations, 2014 CFR

2014-07-01

....174 Section 141.174 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) WATER 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 CFR 141.174 - Filtration sampling requirements.

Code of Federal Regulations, 2013 CFR

2013-07-01

....174 Section 141.174 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) WATER 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...

Spontaneous water filtration of bio-inspired membrane

NASA Astrophysics Data System (ADS)

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).

One-dimensional filtration of pharmaceutical grade phyllosilicate dispersions.

PubMed

Viseras, C; Cerezo, P; Meeten, G H; Lopez-Galindo, A

2001-04-17

The filtration behaviour of some clay-water dispersions was studied. Two Spanish fibrous phyllosilicates (sepiolite from Vicálvaro and palygorskite from Turón) and a commercial bentonite (Bentopharm UK) with similar sizes and different morphologies (fibrous and/or laminar) were selected as model clays. Sepiolite from Vicálvaro is an almost pure fibrous sample, Bentopharm presents a high amount of laminar particles and palygorskite from Turón is made up of similar percentages of laminar and fibrous particles. The disperse systems were made up using a rotor-stator mixer working at two different mixing rates (1000 and 8000 rpm), for periods of 1 and 10 min. Filtration measurements were taken and the corresponding filtration curves obtained. Finally, the desorptivity (S) of the filtration cakes was calculated and correlated to the textural characteristics of the materials, the solid fraction and mixing conditions. Filtration behaviour of the dispersions depended on all three of these factors. Laminar dispersions presented lower S values than fibrous dispersions. In the 2% w/v dispersions the bridging forces between particles did not permit formation of an interconnected network as in 10% w/v dispersions and, consequently, filtration times increased with the solid fraction (i.e. S values decreased). Regarding stability to pH changes, the results showed that filtration behaviour was highly sensitive to basic pH in the fibrous clay dispersions and almost insensitive in the laminar clay dispersions.

40 CFR 141.717 - Pre-filtration treatment toolbox components.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 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 23 2011-07-01 2011-07-01 false Pre-filtration treatment toolbox...

Filter aids influence on pressure drop across a filtration system

NASA Astrophysics Data System (ADS)

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.

40 CFR 141.174 - Filtration sampling requirements.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 22 2010-07-01 2010-07-01 false Filtration sampling requirements. 141...-Systems Serving 10,000 or More People § 141.174 Filtration sampling requirements. (a) Monitoring... sampling every four hours in lieu of continuous monitoring, but for no more than five working days...

40 CFR 141.174 - Filtration sampling requirements.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 40 Protection of Environment 23 2011-07-01 2011-07-01 false Filtration sampling requirements. 141...-Systems Serving 10,000 or More People § 141.174 Filtration sampling requirements. (a) Monitoring... sampling every four hours in lieu of continuous monitoring, but for no more than five working days...

10. OBLIQUE DETAIL VIEW OF PUMP NO. 1 IN FILTRATION ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

10. OBLIQUE DETAIL VIEW OF PUMP NO. 1 IN FILTRATION ROOM IN FILTRATION PLANT (#1773), LOOKING NORTHEAST - Presidio Water Treatment Plant, Filtration Plant, East of Lobos Creek at Baker Beach, San Francisco, San Francisco County, CA

Design parameters for rotating cylindrical filtration

NASA Technical Reports Server (NTRS)

Schwille, John A.; Mitra, Deepanjan; Lueptow, Richard M.

2002-01-01

Rotating cylindrical filtration displays significantly reduced plugging of filter pores and build-up of a cake layer, but the number and range of parameters that can be adjusted complicates the design of these devices. Twelve individual parameters were investigated experimentally by measuring the build-up of particles on the rotating cylindrical filter after a fixed time of operation. The build-up of particles on the filter depends on the rotational speed, the radial filtrate flow, the particle size and the gap width. Other parameters, such as suspension concentration and total flow rate are less important. Of the four mechanisms present in rotating filters to reduce pore plugging and cake build-up, axial shear, rotational shear, centrifugal sedimentation and vortical motion, the evidence suggests rotational shear is the dominant mechanism, although the other mechanisms still play minor roles. The ratio of the shear force acting parallel to the filter surface on a particle to the Stokes drag acting normal to the filter surface on the particle due to the difference between particle motion and filtrate flow can be used as a non-dimensional parameter that predicts the degree of particle build-up on the filter surface for a wide variety of filtration conditions. c2002 Elsevier Science B.V. All rights reserved.

1. Perspective view southwest of filtration bed with earth mounded ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

1. Perspective view southwest of filtration bed with earth mounded over facility. Armory Street appears in the foreground. - Lake Whitney Water Filtration Plant, Filtration Plant, South side of Armory Street between Edgehill Road & Whitney Avenue, Hamden, New Haven County, CT

30. Valves under central corridor of filtration bed building. Main ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

30. Valves under central corridor of filtration bed building. Main flood valves is at left and crossover valve is a right. - Lake Whitney Water Filtration Plant, Filtration Plant, South side of Armory Street between Edgehill Road & Whitney Avenue, Hamden, New Haven County, CT

Crumb rubber filtration: a potential technology for ballast water treatment.

PubMed

Tang, Zhijian; Butkus, Michael A; Xie, Yuefeng F

2006-05-01

The removal of turbidity, particles, phytoplankton and zooplankton in water by crumb rubber filtration was investigated. A substantial reduction was achieved. Of the three variables, filter depth, media size and filtration rate, media size had the most significant influence. Smaller media size favored higher removal efficiency of all targeted matter. There was no apparent relationship between removal efficiency and filter depth. Higher filtration rate resulted in lower removal efficiency and higher head loss. Compared with conventional granular media filters, crumb rubber filters required less backwash, and developed lower head loss. Consequently crumb rubber filters could be run for a longer time or allow a higher filtration rate. The results also indicate that the crumb rubber filtration alone did not achieve the target removal of invasive species. However, crumb rubber filtration could potentially be used as a primary treatment technology to enhance the efficiency of a secondary treatment process (e.g., disinfection).

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

NASA Astrophysics Data System (ADS)

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.

Recycled PET Nanofibers for Water Filtration Applications

PubMed Central

Zander, Nicole E.; Gillan, Margaret; Sweetser, Daniel

2016-01-01

Water shortage is an immediate and serious threat to our world population. Inexpensive and scalable methods to clean freshwater and wastewater are in high demand. Nanofiber filtration membranes represent a next generation nonwoven filter media due to their unique properties. Polyethlyene terephthalate (PET) is often used in the packaging of water and other commonly used materials, leading to a large amount of plastic waste often with limited incentive for recycling (few value-added uses). Here, we present work in the generation of nanofiber liquid filtration membranes from PET plastic bottles and demonstrate their use in microfiltration. PET nanofiber membranes were formed via solution electrospinning with fiber diameters as low as ca. 100 nm. Filtration efficiency was tested with latex beads with sizes ranging from 30 to 2000 nm. Greater than 99% of the beads as small as 500 nm were removed using gravity filtration. To reduce biofouling, the mats were functionalized with quaternary ammonium and biguanide biocides. The biguanide functionalized mats achieved 6 log reduction for both gram negative and gram positive bacteria. PMID:28773380

22. Float located adjacent to entry stair in filtration bed. ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

22. Float located adjacent to entry stair in filtration bed. The float actuates a valve that maintains water level over the bed. - Lake Whitney Water Filtration Plant, Filtration Plant, South side of Armory Street between Edgehill Road & Whitney Avenue, Hamden, New Haven County, CT

2. View east of filtration bed building. Access bridge to ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

2. View east of filtration bed building. Access bridge to earth covering over reinforced concrete roof is at center right of photograph. - Lake Whitney Water Filtration Plant, Filtration Plant, South side of Armory Street between Edgehill Road & Whitney Avenue, Hamden, New Haven County, CT

Wind Turbine Gearbox Oil Filtration and Condition Monitoring

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

Sheng, Shuangwen

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,more » 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.« less

Polyaluminium chloride as an alternative to alum for the direct filtration of drinking water.

PubMed

Zarchi, Idit; Friedler, Eran; Rebhun, Menahem

2013-01-01

The efficiency of various polyaluminium chloride coagulants (PACls) was compared to the efficiency of aluminium sulfate (alum) in the coagulation-flocculation process preceding direct filtration in drinking water treatment. The comparative study consisted of two separate yet complementary series of experiments: the first series included short (5-7 h) and long (24 h) filter runs conducted at a pilot filtration plant equipped with large filter columns that simulated full-scale filters. Partially treated surface water from the Sea of Galilee, characterized by very low turbidity (-1 NTU), was used. In the second series of experiments, speciation of aluminium in situ was investigated using the ferron assay method. Results from the pilot-scale study indicate that most PACls were as or more efficient a coagulant as alum for direct filtration of surface water without requiring acid addition for pH adjustment and subsequent base addition for re-stabilizing the water. Consequently, cost analysis of the chemicals needed for the process showed that treatment with PACl would be significantly less costly than treatment with alum. The aluminium speciation experiments revealed that the performance of the coagulant is more influenced by the species present during the coagulation process than those present in the original reagents.

Long-Term Leukocyte Filtration Should Be Avoided during Extracorporeal Circulation

PubMed Central

Tang, Jiali; Tao, Kaiyu; Zhou, Jing; Zhang, Chongwei; Gong, Lina; Luo, Nanfu

2013-01-01

Filtration during extracorporeal circulation (ECC) not only removes but also activates leukocytes; therefore, long-term leukocyte filtration may cause adverse effects. In the present study, we tested this hypothesis by priming ECC with 300 mL of canine blood and examining filtration effects in 3 groups (n = 6 each) during 60 min ECC. In the control group (Group C) blood was filtrated with an arterial filter for 60 min; in long-term (Group L) and short-term (Group S) groups, blood was filtrated with a leukocyte filter for 60 and 5 min. We found that about 90% of leukocytes were removed after 5 min of filtration in both Groups L and S. Although leukocyte count continued to reduce, mean fluorescent intensities of CD11/CD18, free hemoglobin, and neutrophil elastase increased in Group L and were higher than those in Groups C and S at 60 min. Leukocyte rupture, cytoplasmic leakage, and circulating naked nuclei were also found in Group L. The data support our hypothesis that long-term filtration can induce inflammation and lead to leukocyte destruction. PMID:24453424

In-Water Hull Cleaning & Filtration System

NASA Astrophysics Data System (ADS)

George, Dan

2015-04-01

Dan George R & D Mining Technology LinkedIn GRD Franmarine have received the following prestigious awards in 2014 for their research & development of an in-water hull cleaning and filtration system "The Envirocart: Golden Gecko Award for Environmental Excellence; WA Innovator of the Year - Growth Sector; Department of Fisheries - Excellence in Marine Biosecurity Award - Innovation Category; Lloyd's List Asia Awards - Environmental Award; The Australian Innovation Challenge - Environment, Agriculture and Food Category; and Australian Shipping and Maritime Industry Award - Environmental Transport Award. The Envirocart developed and patented by GRD Franmarine is a revolutionary new fully enclosed capture and containment in-water hull cleaning technology. The Envirocart enables soft Silicon based antifouling paints and coatings containing pesticides such as Copper Oxide to be cleaned in situ using a contactless cleaning method. This fully containerised system is now capable of being deployed to remote locations or directly onto a Dive Support Vessel and is rated to offshore specifications. This is the only known method of in-water hull cleaning that complies with the Department of Agriculture Fisheries and Forestry (DAFF) and Department of Fisheries WA (DoF) Guidelines. The primary underwater cleaning tool is a hydraulically powered hull cleaning unit fitted with rotating discs. The discs can be fitted with conventional brushes for glass or epoxy based coatings or a revolutionary new patented blade system which can remove marine biofouling without damaging the antifouling paint (silicone and copper oxide). Additionally there are a patented range of fully enclosed hand cleaning tools for difficult to access niche areas such as anodes and sea chests, providing an innovative total solution that enables in-water cleaning to be conducted in a manner that causes no biological risk to the environment. In full containment mode or when AIS are present, material is pumped

Vision-related quality of life following glaucoma filtration surgery.

PubMed

Hirooka, Kazuyuki; Nitta, Eri; Ukegawa, Kaori; Tsujikawa, Akitaka

2017-05-12

To evaluate vision-related quality of life (VR-QOL) following glaucoma filtration surgery. A total of 103 glaucoma patients scheduled to undergo glaucoma filtration surgery. Prior to and at three months after glaucoma filtration surgery, trabeculectomy or EX-PRESS, all patients completed the 25-item National Eye Institute Visual Function Questionnaire (VFQ-25). A total of 48 patients underwent combined cataract and filtration surgery. The clinical data collected pre- and postoperatively included best-corrected visual acuity (BCVA) and intraocular pressure (IOP). The IOP decreased significantly from 19.0 ± 8.1 mmHg to 9.7 ± 3.9 mmHg (P < 0.001). Preoperative VFQ-25 composite score (65.8 ± 15.6) was similar to the postoperative score (67.8 ± 16.6). A significantly improved VFQ-25 composite score (pre: 63.2 ± 17.1, post: 67.7 ± 17.8; P = 0.001) was observed in the patients who underwent combined cataract and filtration surgery. There was a significant association between the BCVA changes in the operated eye and the changes in the VFQ-25 composite score (r = -0.315, P = 0.003). Although glaucoma filtration surgery by itself did not decrease the VR-QOL in glaucoma patients, there was significant improvement in the VR-QOL after the patients underwent combined cataract and glaucoma filtration surgery.

Investigation of Microgranular Adsorptive Filtration System

NASA Astrophysics Data System (ADS)

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

THE ROLE OF FILTRATION IN PREVENTING WATERBORNE DISEASE

EPA Science Inventory

Filtration is an important treatment process in the removal of pathogenic microorganisms and the prevention of waterborne disease. Historically, filtration was responsible for reducing death and illness from waterborne disease in 1871 in Germany. Other early examples in the U.S. ...

40 CFR 141.171 - Criteria for avoiding filtration.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 40 Protection of Environment 24 2013-07-01 2013-07-01 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...

40 CFR 141.171 - Criteria for avoiding filtration.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 40 Protection of Environment 23 2014-07-01 2014-07-01 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...

40 CFR 141.171 - Criteria for avoiding filtration.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 40 Protection of Environment 24 2012-07-01 2012-07-01 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...

40 CFR 141.171 - Criteria for avoiding filtration.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 40 Protection of Environment 23 2011-07-01 2011-07-01 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...

21. Overflow pipe in filtration bed. Located at each corner ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

21. Overflow pipe in filtration bed. Located at each corner of the bed, the pipes drain off any excess water and maintain a limit on water depth. - Lake Whitney Water Filtration Plant, Filtration Plant, South side of Armory Street between Edgehill Road & Whitney Avenue, Hamden, New Haven County, CT

Evaluation of emerging factors blocking filtration of high-adjunct-ratio wort.

PubMed

Ma, Ting; Zhu, Linjiang; Zheng, Feiyun; Li, Yongxian; Li, Qi

2014-08-20

Corn starch has become a common adjunct for beer brewing in Chinese breweries. However, with increasing ratio of corn starch, problems like poor wort filtration performance arise, which will decrease production capacity of breweries. To solve this problem, factors affecting wort filtration were evaluated, such as the size of corn starch particle, special yellow floats formed during liquefaction of corn starch, and residual substance after liquefaction. The effects of different enzyme preparations including β-amylase and β-glucanase on filtration rate were also evaluated. The results indicate that the emerging yellow floats do not severely block filtration, while the fine and uniform-shape corn starch particle and its incompletely hydrolyzed residue after liquefaction are responsible for filtration blocking. Application of β-amylase preparation increased the filtration rate of liquefied corn starch. This study is useful for our insight into the filtration blocking problem arising in the process of high-adjunct-ratio beer brewing and also provides a feasible solution using enzyme preparations.

Development of an Indexing Media Filtration System for Long Duration Space Missions

NASA Technical Reports Server (NTRS)

Agui, Juan H.; Vijayakumar, R.

2013-01-01

The effective maintenance of air quality aboard spacecraft cabins will be vital to future human exploration missions. A key component will be the air cleaning filtration system which will need to remove a broad size range of particles derived from multiple biological and material sources. In addition, during surface missions any extraterrestrial planetary dust, including dust generated by near-by ISRU equipment, which is tracked into the habitat will also need to be managed by the filtration system inside the pressurized habitat compartments. An indexing media filter system is being developed to meet the demand for long-duration missions that will result in dramatic increases in filter service life and loading capacity, and will require minimal crew involvement. The filtration system consists of three stages: an inertial impactor stage, an indexing media stage, and a high-efficiency filter stage, packaged in a stacked modular cartridge configuration. Each stage will target a specific range of particle sizes that optimize the filtration and regeneration performance of the system. An 1/8th scale and full-scale prototype of the filter system have been fabricated and have been tested in the laboratory and reduced gravity environments that simulate conditions on spacecrafts, landers and habitats. Results from recent laboratory and reduce-gravity flight tests data will be presented. The features of the new filter system may also benefit other closed systems, such as submarines, and remote location terrestrial installations where servicing and replacement of filter units is not practical.

20. View of sand filtration bed. Wheelbarrow was used to ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

20. View of sand filtration bed. Wheelbarrow was used to remove schmutzdeck (top, dirty sand layer containing particulate contamination, dead microorganisms and debris) for cleaning and or disposal. - Lake Whitney Water Filtration Plant, Filtration Plant, South side of Armory Street between Edgehill Road & Whitney Avenue, Hamden, New Haven County, CT

Vacuum distillation/vapor filtration water recovery

NASA Technical Reports Server (NTRS)

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.

Grating Oriented Line-Wise Filtration (GOLF) for Dual-Energy X-ray CT

NASA Astrophysics Data System (ADS)

Xi, Yan; Cong, Wenxiang; Harrison, Daniel; Wang, Ge

2017-12-01

In medical X-ray Computed Tomography (CT), the use of two distinct X-ray source spectra (energies) allows dose-reduction and material discrimination relative to that achieved with only one source spectrum. Existing dual-energy CT methods include source kVp-switching, double-layer detection, dual-source gantry, and two-pass scanning. Each method suffers either from strong spectral correlation or patient-motion artifacts. To simultaneously address these problems, we propose to improve CT data acquisition with the Grating Oriented Line-wise Filtration (GOLF) method, a novel X-ray filter that is placed between the source and patient. GOLF uses a combination of absorption and filtering gratings that are moved relative to each other and in synchronization with the X-ray tube kVp-switching process and/or the detector view-sampling process. Simulation results show that GOLF can improve the spectral performance of kVp-switching to match that of dual-source CT while avoiding patient motion artifacts and dual imaging chains. Although significant flux is absorbed by this pre-patient filter, the proposed GOLF method is a novel path for cost-effectively extracting dual-energy or multi-energy data and reducing radiation dose with or without kVp switching.

Grating Oriented Line-Wise Filtration (GOLF) for Dual-Energy X-ray CT

PubMed Central

Xi, Yan; Cong, Wenxiang; Harrison, Daniel

2017-01-01

In medical X-ray Computed Tomography (CT), the use of two distinct X-ray source spectra (energies) allows dose-reduction and material discrimination relative to that achieved with only one source spectrum. Existing dual-energy CT methods include source kVp-switching, double-layer detection, dual-source gantry, and two-pass scanning. Each method suffers either from strong spectral correlation or patient-motion artifacts. To simultaneously address these problems, we propose to improve CT data acquisition with the Grating Oriented Line-wise Filtration (GOLF) method, a novel X-ray filter that is placed between the source and patient. GOLF uses a combination of absorption and filtering gratings that are moved relative to each other and in synchronization with the X-ray tube kVp-switching process and/or the detector view-sampling process. Simulation results show that GOLF can improve the spectral performance of kVp-switching to match that of dual-source CT while avoiding patient motion artifacts and dual imaging chains. Although significant flux is absorbed by this pre-patient filter, the proposed GOLF method is a novel path for cost-effectively extracting dual-energy or multi-energy data and reducing radiation dose with or without kVp switching. PMID:29333113

Industrial Application of Open Pore Ceramic Foam for Molten Metal Filtration

NASA Astrophysics Data System (ADS)

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.

A neural network-based method for spectral distortion correction in photon counting x-ray CT

NASA Astrophysics Data System (ADS)

Touch, Mengheng; Clark, Darin P.; Barber, William; Badea, Cristian T.

2016-08-01

Spectral CT using a photon counting x-ray detector (PCXD) shows great potential for measuring material composition based on energy dependent x-ray attenuation. Spectral CT is especially suited for imaging with K-edge contrast agents to address the otherwise limited contrast in soft tissues. We have developed a micro-CT system based on a PCXD. This system enables both 4 energy bins acquisition, as well as full-spectrum mode in which the energy thresholds of the PCXD are swept to sample the full energy spectrum for each detector element and projection angle. Measurements provided by the PCXD, however, are distorted due to undesirable physical effects in the detector and can be very noisy due to photon starvation in narrow energy bins. To address spectral distortions, we propose and demonstrate a novel artificial neural network (ANN)-based spectral distortion correction mechanism, which learns to undo the distortion in spectral CT, resulting in improved material decomposition accuracy. To address noise, post-reconstruction denoising based on bilateral filtration, which jointly enforces intensity gradient sparsity between spectral samples, is used to further improve the robustness of ANN training and material decomposition accuracy. Our ANN-based distortion correction method is calibrated using 3D-printed phantoms and a model of our spectral CT system. To enable realistic simulations and validation of our method, we first modeled the spectral distortions using experimental data acquired from 109Cd and 133Ba radioactive sources measured with our PCXD. Next, we trained an ANN to learn the relationship between the distorted spectral CT projections and the ideal, distortion-free projections in a calibration step. This required knowledge of the ground truth, distortion-free spectral CT projections, which were obtained by simulating a spectral CT scan of the digital version of a 3D-printed phantom. Once the training was completed, the trained ANN was used to perform

Membrane filtration device for studying compression of fouling layers in membrane bioreactors

PubMed Central

Bugge, Thomas Vistisen; Larsen, Poul; Nielsen, Per Halkjær; Christensen, Morten Lykkegaard

2017-01-01

A filtration devise was developed to assess compressibility of fouling layers in membrane bioreactors. The system consists of a flat sheet membrane with air scouring operated at constant transmembrane pressure to assess the influence of pressure on resistance of fouling layers. By fitting a mathematical model, three model parameters were obtained; a back transport parameter describing the kinetics of fouling layer formation, a specific fouling layer resistance, and a compressibility parameter. This stands out from other on-site filterability tests as model parameters to simulate filtration performance are obtained together with a characterization of compressibility. Tests on membrane bioreactor sludge showed high reproducibility. The methodology’s ability to assess compressibility was tested by filtrations of sludges from membrane bioreactors and conventional activated sludge wastewater treatment plants from three different sites. These proved that membrane bioreactor sludge showed higher compressibility than conventional activated sludge. In addition, detailed information on the underlying mechanisms of the difference in fouling propensity were obtained, as conventional activated sludge showed slower fouling formation, lower specific resistance and lower compressibility of fouling layers, which is explained by a higher degree of flocculation. PMID:28749990

Effect of Laminating Pressure on Polymeric Multilayer Nanofibrous Membranes for Liquid Filtration.

PubMed

Yalcinkaya, Fatma; Hruza, Jakub

2018-04-24

In the new century, electrospun nanofibrous webs are widely employed in various applications due to their specific surface area and porous structure with narrow pore size. The mechanical properties have a major influence on the applications of nanofiber webs. Lamination technology is an important method for improving the mechanical strength of nanofiber webs. In this study, the influence of laminating pressure on the properties of polyacrylonitrile (PAN) and polyvinylidene fluoride (PVDF) nanofibers/laminate was investigated. Heat-press lamination was carried out at three different pressures, and the surface morphologies of the multilayer nanofibrous membranes were observed under an optical microscope. In addition, air permeability, water filtration, and contact angle experiments were performed to examine the effect of laminating pressure on the breathability, water permeability and surface wettability of multilayer nanofibrous membranes. A bursting strength test was developed and applied to measure the maximum bursting pressure of the nanofibers from the laminated surface. A water filtration test was performed using a cross-flow unit. Based on the results of the tests, the optimum laminating pressure was determined for both PAN and PVDF multilayer nanofibrous membranes to prepare suitable microfilters for liquid filtration.

UTEX LEACHING, THICKENING AND FILTRATION TESTS. Topical Report

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

Stanley, A.; George, D.R.; Thomas, P.N.

1954-03-15

A series of leaching, thickening, and filtration tests was undertaken to determine minimum conditions for high uranium extractions and obtain thickening and filtration data. The ore represented by the sample responded to cold and hot leaching with the minimum condition for uranium extraction being 500 pounds of H/ sub 2/SO/sub 4/ per ton and five pounds NaClO/sub 3/ per ton leached at room temperature for l6 hours with uranium extraction of over 95%. Thickening and filtration were economical if a reagent such as S-3000 or Guar gum was used. (auth)

Removal of pathogens using riverbank filtration

NASA Astrophysics Data System (ADS)

Cote, M. M.; Emelko, M. B.; Thomson, N. R.

2003-04-01

Although more than hundred years old, in situ or Riverbank Filtration (RBF) has undergone a renewed interest in North America because of its potential as a surface water pre-treatment tool for removal of pathogenic microorganisms. A new RBF research field site has been constructed along the banks of the Grand River in Kitchener, Ontario, Canada to assess factors influencing pathogen removal in the subsurface. Implementation of RBF and appropriate design of subsequent treatment (UV, chlorination, etc.) processes requires successful quantification of in situ removals of Cryptosporidium parvum or a reliable surrogate parameter. C.~parvum is often present in surface water at low indigenous concentrations and can be difficult to detect in well effluents. Since releases of inactivated C.~parvum at concentrations high enough for detection in well effluents are cost prohibitive, other approaches for demonstrating effective in situ filtration of C.~parvum must be considered; these include the use of other microbial species or microspheres as indicators of C.~parvum transport in the environment. Spores of Bacillus subtilis may be considered reasonable indicators of C.~parvum removal by in situ filtration because of their size (˜1 μm in diameter), spherical shape, relatively high indigenous concentration is many surface waters, and relative ease of enumeration. Based on conventional particle filtration theory and assuming equivalent chemical interactions for all particle sizes, a 1 μm B.~subtilis spore will be removed less readily than a larger C. parvum oocyst (4-6 μm) in an ideal granular filter. Preliminary full-scale data obtained from a high rate RBF production well near the new RBF test site demonstrated greater than 1 log removal of B.~subtilis spores. This observed spore removal is higher than that prescribed by the proposed U.S. Long Term 2 Enhanced Surface Water Treatment Rule for C.~parvum. To further investigate the removal relationship between C

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

PubMed

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.

A new approach to determining symmetry groups of filtration properties of porous media in nonlinear filtration laws

NASA Astrophysics Data System (ADS)

Maksimov, V. M.; Dmitriev, N. M.; Dmitriev, M. N.

2017-04-01

Theoretical analysis of filtration properties of porous media for orthotropic and monoclinic symmetry groups has been carried out. It is shown how it is possible to establish a type of symmetry with the help of special laboratory investigations and to distinguish groups with orthotropic and monoclinic symmetry. It is established that the criterion for solving this problem is the use of nonlinear Darcy law at high flow velocities, where the effects of asymmetry of filtration properties manifest themselves upon a change in the flow direction.

Particulate Matter Filtration Design Considerations for Crewed Spacecraft Life Support Systems

NASA Technical Reports Server (NTRS)

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.

Removal of heavy metals from aluminum anodic oxidation wastewaters by membrane filtration.

PubMed

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

Development of an Indexing Media Filtration System for Long Duration Space Missions

NASA Technical Reports Server (NTRS)

Agui, Juan H.; Vijayakumar, R.

2013-01-01

The effective maintenance of air quality aboard spacecraft cabins will be vital to future human exploration missions. A key component will be the air cleaning filtration system which will need to remove a broad size range of particles including skin flakes, hair and clothing fibers, other biological matter, and particulate matter derived from material and equipment wear. In addition, during surface missions any extraterrestrial planetary dust, including dust generated by near-by ISRU equipment, which is tracked into the habitat will also need to be managed by the filtration system inside the pressurized habitat compartments. An indexing media filter system is being developed to meet the demand for long-duration missions that will result in dramatic increases in filter service life and loading capacity, and will require minimal crew involvement. These features may also benefit other closed systems, such as submarines, and remote location terrestrial installations where servicing and replacement of filter units is not practical. The filtration system consists of three stages: an inertial impactor stage, an indexing media stage, and a high-efficiency filter stage, packaged in a stacked modular cartridge configuration. Each stage will target a specific range of particle sizes that optimize the filtration and regeneration performance of the system. An 1/8th scale and full-scale prototype of the filter system have been fabricated and have been tested in the laboratory and reduced gravity environments that simulate conditions on spacecrafts, landers and habitats. Results from recent laboratory and reducegravity flight tests data will be presented.

Application of acoustic agglomeration to enhance air filtration efficiency in air-conditioning and mechanical ventilation (ACMV) systems.

PubMed

Ng, Bing Feng; Xiong, Jin Wen; Wan, Man Pun

2017-01-01

The recent episodes of haze in Southeast Asia have caused some of the worst regional atmospheric pollution ever recorded in history. In order to control the levels of airborne fine particulate matters (PM) indoors, filtration systems providing high PM capturing efficiency are often sought, which inadvertently also results in high airflow resistance (or pressure drop) that increases the energy consumption for air distribution. A pre-conditioning mechanism promoting the formation of particle clusters to enhance PM capturing efficiency without adding flow resistance in the air distribution ductwork could provide an energy-efficient solution. This pre-conditioning mechanism can be fulfilled by acoustic agglomeration, which is a phenomenon that promotes the coagulation of suspended particles by acoustic waves propagating in the fluid medium. This paper discusses the basic mechanisms of acoustic agglomeration along with influencing factors that could affect the agglomeration efficiency. The feasibility to apply acoustic agglomeration to improve filtration in air-conditioning and mechanical ventilation (ACMV) systems is investigated experimentally in a small-scale wind tunnel. Experimental results indicate that this novel application of acoustic pre-conditioning improves the PM2.5 filtration efficiency of the test filters by up to 10% without introducing additional pressure drop. The fan energy savings from not having to switch to a high capturing efficiency filter largely outstrip the additional energy consumed by the acoustics system. This, as a whole, demonstrates potential energy savings from the combined acoustic-enhanced filtration system without compromising on PM capturing efficiency.

Application of acoustic agglomeration to enhance air filtration efficiency in air-conditioning and mechanical ventilation (ACMV) systems

PubMed Central

Xiong, Jin Wen; Wan, Man Pun

2017-01-01

The recent episodes of haze in Southeast Asia have caused some of the worst regional atmospheric pollution ever recorded in history. In order to control the levels of airborne fine particulate matters (PM) indoors, filtration systems providing high PM capturing efficiency are often sought, which inadvertently also results in high airflow resistance (or pressure drop) that increases the energy consumption for air distribution. A pre-conditioning mechanism promoting the formation of particle clusters to enhance PM capturing efficiency without adding flow resistance in the air distribution ductwork could provide an energy-efficient solution. This pre-conditioning mechanism can be fulfilled by acoustic agglomeration, which is a phenomenon that promotes the coagulation of suspended particles by acoustic waves propagating in the fluid medium. This paper discusses the basic mechanisms of acoustic agglomeration along with influencing factors that could affect the agglomeration efficiency. The feasibility to apply acoustic agglomeration to improve filtration in air-conditioning and mechanical ventilation (ACMV) systems is investigated experimentally in a small-scale wind tunnel. Experimental results indicate that this novel application of acoustic pre-conditioning improves the PM2.5 filtration efficiency of the test filters by up to 10% without introducing additional pressure drop. The fan energy savings from not having to switch to a high capturing efficiency filter largely outstrip the additional energy consumed by the acoustics system. This, as a whole, demonstrates potential energy savings from the combined acoustic-enhanced filtration system without compromising on PM capturing efficiency. PMID:28594862

Pharmacologic Atrial Natriuretic Peptide Reduces Human Leg Capillary Filtration

NASA Technical Reports Server (NTRS)

Watenpaugh, Donald E.; Vissing, Susanne F.; Lane, Lynda D.; Buckey, Jay C.; Firth, Brian G.; Erdman, William; Hargens, Alan R.; Blomqvist, C. Gunnar

1995-01-01

Atrial natriuretic peptide (ANP) is produced and secreted by atrial cells. We measured calf capillary filtration rate with prolonged venous-occlusion plethysmography of supine healthy male subjects during pharmacologic infusion of ANP (48 pmol/kg/min for 15 min; n = 6) and during placebo infusion (n = 7). Results during infusions were compared to prior control measurements. ANP infusion increased plasma (ANP) from 30 +/- 4 to 2,568 +/- 595 pmol/L. Systemic hemoconcentration occurred during ANP infusion: mean hematocrit and plasma colloid osmotic pressure increased 4.6 and 11.3%, respectively, relative to preinfusion baseline values (p less than 0.05). Mean calf filtration, however, was significantly reduced from 0.15 to 0.08 ml/100 ml/min with ANP. Heart rate increased 20% with ANP infusion, whereas blood pressure was unchanged. Calf conductance (blood flow/ arterial pressure) and venous compliance were unaffected by ANP infusion. Placebo infusion had no effect relative to prior baseline control measurements. Although ANP induced systemic capillary filtration, in the calf, filtration was reduced with ANP. Therefore, pharmacologic ANP infusion enhances capillary filtration from the systemic circulation, perhaps at upper body or splanchnic sites or both, while having the opposite effect in the leg.

Spectral-domain Optical Coherence Tomography in Manifest Glaucoma: Its Additive Role in Structural Diagnosis.

PubMed

Kim, Ko Eun; Oh, Sohee; Jeoung, Jin Wook; Suh, Min Hee; Seo, Je Hyun; Kim, Martha; Park, Ki Ho; Kim, Dong Myung; Kim, Seok Hwan

2016-11-01

To investigate the additive role of spectral-domain optical coherence tomography (SDOCT) in the structural diagnosis in glaucoma. Reliability and validity analysis. Structural examinations from 109 eyes of 109 healthy individuals and 151 eyes of 151 glaucoma patients with different severities were included. Four structural-diagnostic examination sets were prepared using stereo-optic disc photography (SDP), red-free retinal nerve fiber layer photography (RNFLP), and SDOCT: (1) SDP (S), (2) SDP and SDOCT (SO), (3) SDP and RNFLP (SR), and (4) SDP, RNFLP, and SDOCT (SRO). Five glaucoma specialists were instructed to classify subjects as normal or glaucoma using each of the 4 diagnostic sets in the order S, SO, SR, and SRO, with a 1-month interval. The interobserver agreement was evaluated using kappa (κ) statistics. The additive effect of SDOCT on the diagnostic performance of the specialists was evaluated using the generalized estimating equation. Five glaucoma specialists showed an excellent level of interobserver agreement on the diagnostic assessments based on the 4 sets. In the comparison of the collective diagnostic performance of the specialists, addition of SDOCT to SDP showed an approximately 2-fold significant increase in the diagnostic accuracy. Adding SDOCT to SDP significantly enhanced the specialists' structural-diagnostic ability with respect to the moderate glaucoma, though not mild or advanced glaucoma. SDOCT significantly enhanced the diagnostic accuracy of the glaucoma specialists' performance, showing its additive diagnostic value in judging glaucomatous structural damage, especially in the moderate stage of glaucoma. Copyright © 2016 Elsevier Inc. All rights reserved.

RIVERBANK FILTRATION: FATE OF DBP PRECURSORS AND SELECTED MICROORGANISMS

EPA Science Inventory

The fate of disinfection by-product (DBP) precursors and selected microorganisms during riverbank filtration (RBF) was monitored at three different mid-Western drinking water utilities. At all three sites, filtration (RBF) was monitored at three different mid-Western drinking wa...

STORMWATER TREATMENT AT CRITICAL AREAS: EVALUATION OF FILTRATION MEDIA

EPA Science Inventory

Past research has identified urban runoff as a major contributor to the degradation of urban streams and rivers. Filtration, especially "slow" filtration, is of interest for stormwater runoff treatment because filters will work on intermittent flows without significant loss of ca...

Water Treatment Technology - Filtration.

ERIC Educational Resources Information Center

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…

Fluorometric Method for Determining the Efficiency of Spun-Glass Air Filtration Media

PubMed Central

Sullivan, James F.; Songer, Joseph R.; Mathis, Raymond G.

1967-01-01

The procedures and equipment needed to measure filtration efficiency by means of fluorescent aerosols are described. The filtration efficiency of individual lots of spun-glass air filtration medium or of entire air filtration systems employing such media was determined. Data relating to the comparative evaluation of spun-glass filter media by means of the fluorometric method described, as well as by conventional biological procedures, are presented. PMID:6031433

Pharmacologic Atrial Natriuretic Peptide Reduces Human Leg Capillary Filtration

NASA Technical Reports Server (NTRS)

Watenpaugh, Donald E.; Vissing, Susanne F.; Lane, Lynda D.; Buckey, Jay C.; Firth, Brian G.; Erdman, William; Hargens, Alan R.; Blomqvist, C. Gunnar

1995-01-01

Atrial natriuretic peptide (ANP) is produced and secreted by atrial cells. We measured calf capillary filtration rate with prolonged venous-occlusion plethys-mography of supine health male subjects during pharmacologic infusion of ANP (48 pmol/kg/min for 15 min; n equals 6) and during placebo infusion (n equals 7). Results during infusions were compared to prior control measurements. ANP infusion increased plasma (ANP) from 30 plus or minus 4 to 2,568 plus or minus 595 pmol/L. Systemic hemoconcentration occurred during ANP infusion; mean hematocrit and plasma colloid osmotic pressure increased 4.6 and 11.3 percent respectively, relative to pre-infusion baseline values (p is less than 0.05). Mean calf filtration, however was significantly reduced from 0.15 to 0.08 ml/100 ml/min with ANP. Heart rate increased 20 percent with ANP infusion, wheras blood pressure was unchanged. Calf conductance (blood flow/arterial pressure) and venous compliance were unaffected by ANP infusion. Placebo infusion had no effect relative to prior baseline control measurements. Although ANP induced systemic capillary filtration, in the calf, filtration was reduced with ANP. Therefore, phamacologic ANP infusion enhances capillary filtration from the systemic circulation, perhaps at upper body or splanchic sites or both, while having the opposite effect in the leg.

Quantifying oil filtration effects on bearing life

NASA Technical Reports Server (NTRS)

Needelman, William M.; Zaretsky, Erwin V.

1991-01-01

Rolling-element bearing life is influenced by the number, size, and material properties of particles entering the Hertzian contact of the rolling element and raceway. In general, rolling-element bearing life increases with increasing level of oil filtration. Based upon test results, two equations are presented which allow for the adjustment of bearing L(sub 10) or catalog life based upon oil filter rating. It is recommended that where no oil filtration is used catalog life be reduced by 50 percent.

11. DETAIL VIEW OF FILTER TANK IN FILTRATION PLANT (#1773), ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

11. DETAIL VIEW OF FILTER TANK IN FILTRATION PLANT (#1773), LOOKING NORTHWEST - Presidio Water Treatment Plant, Filtration Plant, East of Lobos Creek at Baker Beach, San Francisco, San Francisco County, CA

12. OBLIQUE VIEW OF NORTH WORK ROOM IN FILTRATION PLANT ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

12. OBLIQUE VIEW OF NORTH WORK ROOM IN FILTRATION PLANT (#1773), LOOKING NORTHWEST - Presidio Water Treatment Plant, Filtration Plant, East of Lobos Creek at Baker Beach, San Francisco, San Francisco County, CA

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

PubMed

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.

7. WEYMOUTH FILTRATION PLANT, BUILDING 1 INTERIOR: LA VERNE CONTROL ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

7. WEYMOUTH FILTRATION PLANT, BUILDING 1 INTERIOR: LA VERNE CONTROL ROOM, REGULATES DISTRIBUTION OF WATER, CONTROLS POWER HOUSES. - F. E. Weymouth Filtration Plant, 700 North Moreno Avenue, La Verne, Los Angeles County, CA

Purification of contaminated water by filtration through porous glass

NASA Technical Reports Server (NTRS)

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.

Pathogen filtration to control plant disease outbreak in greenhouse production

NASA Astrophysics Data System (ADS)

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

Evaluation of biological hydrogen sulfide oxidation coupled with two-stage upflow filtration for groundwater treatment.

PubMed

Levine, Audrey D; Raymer, Blake J; Jahn, Johna

2004-01-01

Hydrogen sulfide in groundwater can be oxidized by aerobic bacteria to form elemental sulfur and biomass. While this treatment approach is effective for conversion of hydrogen sulfide, it is important to have adequate control of the biomass exiting the biological treatment system to prevent release of elemental sulfur into the distribution system. Pilot scale tests were conducted on a Florida groundwater to evaluate the use of two-stage upflow filtration downstream of biological sulfur oxidation. The combined biological and filtration process was capable of excellent removal of hydrogen sulfide and associated turbidity. Additional benefits of this treatment approach include elimination of odor generation, reduction of chlorine demand, and improved stability of the finished water.

Commission 45: Spectral Classification

NASA Astrophysics Data System (ADS)

Giridhar, Sunetra; Gray, Richard O.; Corbally, Christopher J.; Bailer-Jones, Coryn A. L.; Eyer, Laurent; Irwin, Michael J.; Kirkpatrick, J. Davy; Majewski, Steven; Minniti, Dante; Nordström, Birgitta

This report gives an update of developments (since the last General Assembly at Prague) in the areas that are of relevance to the commission. In addition to numerous papers, a new monograph entitled Stellar Spectral Classification with Richard Gray and Chris Corbally as leading authors will be published by Princeton University Press as part of their Princeton Series in Astrophysics in April 2009. This book is an up-to-date and encyclopedic review of stellar spectral classification across the H-R diagram, including the traditional MK system in the blue-violet, recent extensions into the ultraviolet and infrared, the newly defined L-type and T-type spectral classes, as well as spectral classification of carbon stars, S-type stars, white dwarfs, novae, supernovae and Wolf-Rayet stars.

Turbine lubricating oil: New filtration advances save time and money

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

Bushar, T.

1996-11-01

This article describes benefits of filtration advances which include fewer forced outages, faster startups and reduced bearing wear. The importance of clean lubricating oil for turbines has been recognized for a long time, and almost all generating plants use some type of filtration system. Many older technologies and systems cannot remove enough of the contaminants to meet the needs of today`s turbines and operating conditions. Newer filtration technologies, such as multiphase filtration systems incorporating pressure coalescence filters to remove water, can reduce contaminants to levels that will help prevent unscheduled or forced outages, allow faster startups after an ongoing outage,more » and reduce wear of bearings and other components. Such preventive measures are more important than ever because of today`s increased competition and emphasis on cost control.« less

Landfill Leachate Treatment by Electrocoagulation and Fiber Filtration.

PubMed

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.

Topical Silver Nanoparticles Result in Improved Bleb Function by Increasing Filtration and Reducing Fibrosis in a Rabbit Model of Filtration Surgery

PubMed Central

Butler, Michelle R.; Prospero Ponce, Claudia M.; Weinstock, Y. Etan; Orengo-Nania, Silvia; Chevez-Barrios, Patricia; Frankfort, Benjamin J.

2013-01-01

Purpose. To compare the effects of silver nanoparticles (AgNPs) and mitomycin C (MMC) on intraocular pressure (IOP) and external, histologic, and immunohistochemical bleb characteristics in a rabbit model of filtration surgery. Methods. Filtration surgery with concurrent topical application of either AgNPs or MMC was performed on 14 pigmented Dutch Belted rabbits. IOP and bleb characteristics were compared on postoperative day 1 and at weeks 1 through 6. Hematoxylin and eosin staining and smooth muscle actin (SMA) immunohistochemistry were performed at postoperative week 6. Results. Average IOP across all time points was reduced 5.8 and 3.8 mm Hg in AgNP- and MMC-treated eyes, respectively. At week 6, IOP was reduced 4.1 and 0.2 mm Hg in AgNP- and MMC-treated eyes, respectively. Blebs were smaller, thicker, and less ischemic in AgNP-treated eyes. AgNP-treated eyes showed less fibrosis and more stromal edema, suggesting increased filtration, and also had fewer SMA-positive myofibroblasts, suggesting reduced bleb contraction. AgNP-treated eyes showed more lymphocytes than MMC-treated eyes. There were few complications in both groups. Conclusions. In a rabbit model of filtration surgery, AgNPs are a reasonable alternative to MMC as adjunctive therapy. Compared to MMC, AgNPs result in an improved and sustained reduction of IOP and promote blebs with decreased fibrosis and ischemia as well as increased filtration despite a smaller overall size. This combination may offer an opportunity to promote long-term surgical IOP reduction with an improved complication profile. PMID:23766475

Simultaneous removal of phosphorus and EfOM using MIEX, coagulation, and low-pressure membrane filtration.

PubMed

Kim, Hyun-Chul; Timmes, Thomas C; Dempsey, Brian A

2015-01-01

The feasibility of using magnetic ion exchange (MIEX) treatment, in-line alum coagulation, and low-pressure membrane filtration was investigated for the simultaneous removal of total phosphorus (TP) and effluent organic matter (EfOM) from biologically treated wastewater. The focus was also placed on minimizing fouling of polyvinylidene fluoride and polyethersulfone membranes, which are the most commonly used low-pressure membranes in new and retrofit wastewater treatment plants. MIEX alone was effective for the removal of EfOM, and MIEX plus a small alum dose was very effective in removing both EfOM and TP. MIEX removed phosphorus, but organic acids in EfOM were preferentially removed, and the effects of competing anions on the removal of EfOM were insignificant. All the pretreatment strategies decreased the resistance to filtration. The greatest decrease in fouling was achieved by using MIEX (15 mL L⁻¹) plus a very low dose of alum (∼0.5 mg Al L⁻¹). Sweep floc coagulation using alum and without MIEX also significantly decreased fouling but did not effectively remove EfOM and produced high floc volume that could be problematic for inside-out hollow-fibre modules. The addition of these reagents into rapid mix followed by membrane filtration would provide operational simplicity and could be easily retrofitted at existing membrane filtration facilities.

3. INTERIOR OF THE WATER FILTRATION PLANT SHOWING REMAINS OF ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

3. INTERIOR OF THE WATER FILTRATION PLANT SHOWING REMAINS OF THE FILTRATION APPARATUS. - Tower Hill No. 2 Mine, Approximately 0.47 mile Southwest of intersection of Stone Church Road & Township Route 561, Hibbs, Fayette County, PA

Contributions of gross spectral properties and duration of spectral change to perception of stop consonants

NASA Astrophysics Data System (ADS)

Alexander, Joshua; Keith, Kluender

2005-09-01

All speech contrasts are multiply specified. For example, in addition to onsets and trajectories of formant transitions, gross spectral properties such as tilt, and duration of spectral change (both local and global) contribute to perception of contrasts between stops such as /b,d,g/. It is likely that listeners resort to different acoustic characteristics under different listening conditions. Hearing-impaired listeners, for whom spectral details are compromised, may be more likely to use short-term gross spectral characteristics as well as durational information. Here, contributions of broad spectral onset properties as well as duration of spectral change are investigated in perception experiments with normal-hearing listeners. Two series of synthesized CVs, each varying perceptually from /b/ to /d/, were synthesized. Onset frequency of F2, duration of formant transitions, and gross spectral tilts were manipulated parametrically. Perception of /b/ was encouraged by shorter formant transition durations and by more negative spectral tilt at onset independent of the rate of change in spectral tilt. Effects of spectral tilt at onset were contextual and depended on the tilt of the following vowel. Parallel studies with listeners with hearing impairment are ongoing. [Work supported by NIDCD.

Silver nanoparticle-doped zirconia capillaries for enhanced bacterial filtration.

PubMed

Wehling, Julia; Köser, Jan; Lindner, Patrick; Lüder, Christian; Beutel, Sascha; Kroll, Stephen; Rezwan, Kurosch

2015-03-01

Membrane clogging and biofilm formation are the most serious problems during water filtration. Silver nanoparticle (Agnano) coatings on filtration membranes can prevent bacterial adhesion and the initiation of biofilm formation. In this study, Agnano are immobilized via direct reduction on porous zirconia capillary membranes to generate a nanocomposite material combining the advantages of ceramics being chemically, thermally and mechanically stable with nanosilver, an efficient broadband bactericide for water decontamination. The filtration of bacterial suspensions of the fecal contaminant Escherichia coli reveals highly efficient bacterial retention capacities of the capillaries of 8 log reduction values, fulfilling the requirements on safe drinking water according to the U.S. Environmental Protection Agency. Maximum bacterial loading capacities of the capillary membranes are determined to be 3×10(9)bacterialcells/750mm(2) capillary surface until back flushing is recommendable. The immobilized Agnano remain accessible and exhibit strong bactericidal properties by killing retained bacteria up to maximum bacterial loads of 6×10(8)bacterialcells/750mm(2) capillary surface and the regenerated membranes regain filtration efficiencies of 95-100%. Silver release is moderate as only 0.8% of the initial silver loading is leached during a three-day filtration experiment leading to average silver contaminant levels of 100μg/L. Copyright © 2014 Elsevier B.V. All rights reserved.

Activities of Aureobasidium pullulans cell filtrates against Monilinia laxa of peaches.

PubMed

Di Francesco, Alessandra; Roberti, Roberta; Martini, Camilla; Baraldi, Elena; Mari, Marta

2015-12-01

The Aureobasidium pullulans L1 and L8 strains are known as efficient biocontrol agents against several postharvest fungal pathogens. In order to better understand the mechanism of action underneath the antifungal activity of L1 and L8 strains, yeast cell filtrates grown at different times were evaluated in vivo against Monilinia laxa on peach. Lesion diameters on peach fruit were reduced by L1 and L8 culture filtrates of 42.5% and 67% respectively. The ability of these filtrates to inhibit M. laxa conidia germination and germ tube elongation was studied by in vitro assays. The results showed a 70% reduction of conidia germination for both strains while for germ tube elongation, it was 52% and 41% for L1 and L8 culture filtrates respectively. Finally, the activity of cell wall hydrolytic enzymes such as chitinase and glucanase in cell filtrates was analysed and the expression of genes encoding these activities was quantified during yeast growth. From 24h onward, both culture filtrates contained β,1-3,glucanase and. chitinase activities, the most pronounced of which was N-β-acetylglucosaminidase. Gene expression level encoding for these enzymes in L1 and L8 varied according to the strain. These results indicate that L1 and L8 strains culture filtrates retain the yeast antagonistic activity and suggest that the production of hydrolytic enzymes plays an important role in this activity. Copyright © 2015 Elsevier GmbH. All rights reserved.

Effect of membrane filtration artifacts on dissolved trace element concentrations

USGS Publications Warehouse

Horowitz, Arthur J.; Elrick, Kent A.; Colberg, Mark R.

1992-01-01

Among environment scientists, the current and almost universally accepted definition of dissolved constituents is an operational one; only those materials which pass through a 0.45-??m membrane filter are considered to be dissolved. Detailed laboratory and field studies on Fe and Al indicate that a number of factors associated with filtration, other than just pore size, can substantially alter 'dissolved' trace element concentrations; these include: filter type, filter diameter, filtration method, volume of sample processed, suspended sediment concentration, suspended sediment grain-size distribution, concentration of colloids and colloidally associated trace elements and concentration of organic matter. As such, reported filtered-water concentrations employing the same pore size filter may not be equal. Filtration artifacts may lead to the production of chemical data that indicate seasonal or annual 'dissolved' chemical trends which do not reflect actual environmental conditions. Further, the development of worldwide averages for various dissolved chemical constituents, the quantification of geochemical cycles, and the determination of short- or long-term environmental chemical trends may be subject to substantial errors, due to filtration artifacts, when data from the same or multiple sources are combined. Finally, filtration effects could have a substantial impact on various regulatory requirements.

Multispectral Image Compression for Improvement of Colorimetric and Spectral Reproducibility by Nonlinear Spectral Transform

NASA Astrophysics Data System (ADS)

Yu, Shanshan; Murakami, Yuri; Obi, Takashi; Yamaguchi, Masahiro; Ohyama, Nagaaki

2006-09-01

The article proposes a multispectral image compression scheme using nonlinear spectral transform for better colorimetric and spectral reproducibility. In the method, we show the reduction of colorimetric error under a defined viewing illuminant and also that spectral accuracy can be improved simultaneously using a nonlinear spectral transform called Labplus, which takes into account the nonlinearity of human color vision. Moreover, we show that the addition of diagonal matrices to Labplus can further preserve the spectral accuracy and has a generalized effect of improving the colorimetric accuracy under other viewing illuminants than the defined one. Finally, we discuss the usage of the first-order Markov model to form the analysis vectors for the higher order channels in Labplus to reduce the computational complexity. We implement a multispectral image compression system that integrates Labplus with JPEG2000 for high colorimetric and spectral reproducibility. Experimental results for a 16-band multispectral image show the effectiveness of the proposed scheme.

Feature Transformation Detection Method with Best Spectral Band Selection Process for Hyper-spectral Imaging

NASA Astrophysics Data System (ADS)

Chen, Hai-Wen; McGurr, Mike; Brickhouse, Mark

2015-11-01

We present a newly developed feature transformation (FT) detection method for hyper-spectral imagery (HSI) sensors. In essence, the FT method, by transforming the original features (spectral bands) to a different feature domain, may considerably increase the statistical separation between the target and background probability density functions, and thus may significantly improve the target detection and identification performance, as evidenced by the test results in this paper. We show that by differentiating the original spectral, one can completely separate targets from the background using a single spectral band, leading to perfect detection results. In addition, we have proposed an automated best spectral band selection process with a double-threshold scheme that can rank the available spectral bands from the best to the worst for target detection. Finally, we have also proposed an automated cross-spectrum fusion process to further improve the detection performance in lower spectral range (<1000 nm) by selecting the best spectral band pair with multivariate analysis. Promising detection performance has been achieved using a small background material signature library for concept-proving, and has then been further evaluated and verified using a real background HSI scene collected by a HYDICE sensor.

Filtration device for active effluents

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

Guerin, M.; Meunier, G.

1994-12-31

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.

Evaluation of Filtration and UV Disinfection for Inactivation of ...

EPA Pesticide Factsheets

This study evaluated filtration and disinfection processes for removal and inactivation of pathogens in non-community water systems (NCWS) in two surface water supplies. Pretreatment systems included 1) pressure sand filtration, and 2) granular activated carbon adsorption, and 3) cartridge filtration. Two types of low-pressure UV systems were evaluated with and without pretreatment systems. The presentation will provide results for removal of particles and inactivation of MS2 bacteriophage (a viral surrogate) on two surface waters in northeastern Minnesota. Several studies, including a recent study conducted by Minnesota Department of Health (MDH), show that viruses occur in groundwater at a higher rate than expected. Based on preliminary results in Minnesota, virus occurrence appears to be correlated with recharge events such as heavy rainfall and snowmelt. These recharge events are predicted to become more extreme due to climate change impacts. Filtration, ultraviolet (UV) disinfection, and chlorination, can provide a multi-barrier approach for removal or inactivation of pathogens and DBP precursors in both groundwater and surface water systems.

Experimental investigation of air pressure affecting filtration performance of fibrous filter sheet.

PubMed

Xu, Bin; Yu, Xiao; Wu, Ya; Lin, Zhongping

2017-03-01

Understanding the effect of air pressure on their filtration performance is important for assessing the effectiveness of fibrous filters under different practical circumstances. The effectiveness of three classes of air filter sheets were investigated in laboratory-based measurements at a wide range of air pressures (60-130 KPa). The filtration efficiency was found most sensitive to the air pressure change at smaller particle sizes. As the air pressure increased from 60 to 130 KPa, significant decrease in filtration efficiency (up to 15%) and increase in pressure drop (up to 90 Pa) were observed. The filtration efficiency of the filter sheet with largest fiber diameter and smallest solid volume fraction was affected most, while the pressure drop of the filter sheet with smallest fiber diameter and largest solid volume fraction was affected most. The effect of air pressure on the filtration efficiency was slightly larger at greater filter face air velocity. However, the effect of air pressure on the pressure drop was negligible. The filtration efficiency and pressure drop were explicitly expressed as functions of the air pressure. Two coefficients were empirically derived and successfully accounted for the effects of air pressure on filtration efficiency and pressure drop.

Comparison of Garnet Bead Media Filtration and Multimedia Filtration for Turbidity and Microbial Pathogen Removal

EPA Science Inventory

U.S. Environmental Protection Agency’s (EPA’s) National Risk Management Research Laboratory (NRMRL) in Cincinnati, Ohio is evaluating drinking water filtration systems to determine their capability to meet the requirements of the Long-Term 2 Enhanced Surface Water Treatment Rule ...

Health benefits of particle filtration

EPA Science Inventory

This product was developed under an interagency agreement between the U.S. EPA and the U.S. Department of Energy - Lawrence Berkeley National Laboratory (LBNL). The evidence of health benefits of particle filtration in homes and commercial buildings is reviewed. Prior reviews o...

Angiogenesis in Glaucoma Filtration Surgery and Neovascular Glaucoma-A Review

PubMed Central

Kim, Megan; Lee, Chelsea; Payne, Rachael; Yue, Beatrice Y.J.T.; Chang, Jin-Hong; Ying, Hongyu

2015-01-01

Angiogenesis may pose a clinical challenge in glaucoma, for example during the wound healing phase after glaucoma filtration surgery and in a severe form of secondary glaucoma called neovascular glaucoma (NVG). Up regulation of vascular endothelial growth factor (VEGF), a key mediator of angiogenesis, occurs in eyes that have undergone glaucoma filtration surgery, as well as those with NVG. This has led to studies investigating the ability of anti-VEGF therapy to improve outcomes, and we examine their findings with respect to the safety and efficacy of anti-VEGF agents, mainly bevacizumab and ranibizumab, in eyes that have undergone glaucoma filtration surgery or have NVG. Combining conventional therapies—such as anti-metabolites after filtration surgery and panretinal photocoagulation in NVG—and anti-VEGF drugs may achieve a synergetic effect, although further studies are required to evaluate the long-term efficacy of combination treatments. PMID:25980779

Influence of the rate of filtration of a complexly alloyed nickel melt through a foam-ceramic filter on the sulfur impurity content in the metal

NASA Astrophysics Data System (ADS)

Sidorov, V. V.; Min, P. G.; Folomeikin, Yu. I.; Vadeev, V. E.

2015-06-01

The article discusses the possibility of additional refining of a complexly alloyed nickel melt from a sulfur impurity by decreasing the filtration rate during the passage of the melt through a foam-ceramic filter. The degree of sulfur removal from the melt is shown to depend on its content in the alloy and the melt filtration rate.

Effects of discharge fluctuation and the addition of fine sediment on stream fish and macroinvertebrates below a water-filtration facility

NASA Astrophysics Data System (ADS)

Erman, Don C.; Ligon, Franklin K.

1988-01-01

A small, coastal stream in the San Francisco Bay area of California, USA, received the discharges from a drinking-water filtration plant. Two types of discharges were present. Discharges from filter backwashing were 3 4 times base stream flow, occurred 10 60 times per day, contained fine sediments, and each lasted about 10 min. The other discharge was a large, steady flow of relatively sediment-free water from occasional overflow of the delivery aqueduct which generally lasted several hours a day. Samples of invertebrates from natural substrates had significantly fewer taxa and lower density at the two stations below the backwash than at the two above. However, when stable artificial substrates were used, there were no significant differences among all four stations. The aqueduct apparently had no effect because the. invertebrate community at the station upstream of the backwash but downstream of the aqueduct was statistically similar to the station above the aqueduct. To test for acute toxicity, we exposed additional artificial substrates to short-term simulated backwash conditions. These exposures had no effect on invertebrate density or drift. Three-spine stickleback ( Gasterosteus aculeatus) populations were also significantly reduced at the two downstream stations and were made up mostly of larger, adult fish. Prickly sculpins ( Cottus asper), restricted to the most downstream station, were emaciated and had poor growth, probably as a result of scarce benthic food organisms. Artificial redds with eggs of rainbow trout ( Salmo gairdneri) had significantly lower survival at two stations below the plant backwash (30.7% and 41.8%) than at the one above it (61.4%). Hatchery rainbow trout held in cages below the treatment plant from 7 to 37 days survived and continued to feed. Thus, the major effect of the water treatment plant on fish and invertebrates probably was not from acute toxicity in the discharges or the occasionally large discharge of clean water from the

Recent Trends in Nanofibrous Membranes and Their Suitability for Air and Water Filtrations

PubMed Central

Balamurugan, Ramalingam; Sundarrajan, Subramanian; Ramakrishna, Seeram

2011-01-01

In recent decades, engineered membranes have become a viable separation technology for a wide range of applications in environmental, food and biomedical fields. Membranes are now competitive compared to conventional techniques such as adsorption, ion exchangers and sand filters. The main advantage of membrane technology is the fact that it works without the addition of any chemicals, with relatively high efficiency and low energy consumption with well arranged process conductions. Hence they are widely utilized in biotechnology, food and drink manufacturing, air filtration and medical uses such as dialysis for kidney failure patients. Membranes from nanofibrous materials possess high surface area to volume ratio, fine tunable pore sizes and their ease of preparation prompted both industry and academic researchers to study their use in many applications. In this paper, modern concepts and current research progress on various nanofibrous membranes, such as water and air filtration media, are presented. PMID:24957734

SpectralNET--an application for spectral graph analysis and visualization.

PubMed

Forman, Joshua J; Clemons, Paul A; Schreiber, Stuart L; Haggarty, Stephen J

2005-10-19

Graph theory provides a computational framework for modeling a variety of datasets including those emerging from genomics, proteomics, and chemical genetics. Networks of genes, proteins, small molecules, or other objects of study can be represented as graphs of nodes (vertices) and interactions (edges) that can carry different weights. SpectralNET is a flexible application for analyzing and visualizing these biological and chemical networks. Available both as a standalone .NET executable and as an ASP.NET web application, SpectralNET was designed specifically with the analysis of graph-theoretic metrics in mind, a computational task not easily accessible using currently available applications. Users can choose either to upload a network for analysis using a variety of input formats, or to have SpectralNET generate an idealized random network for comparison to a real-world dataset. Whichever graph-generation method is used, SpectralNET displays detailed information about each connected component of the graph, including graphs of degree distribution, clustering coefficient by degree, and average distance by degree. In addition, extensive information about the selected vertex is shown, including degree, clustering coefficient, various distance metrics, and the corresponding components of the adjacency, Laplacian, and normalized Laplacian eigenvectors. SpectralNET also displays several graph visualizations, including a linear dimensionality reduction for uploaded datasets (Principal Components Analysis) and a non-linear dimensionality reduction that provides an elegant view of global graph structure (Laplacian eigenvectors). SpectralNET provides an easily accessible means of analyzing graph-theoretic metrics for data modeling and dimensionality reduction. SpectralNET is publicly available as both a .NET application and an ASP.NET web application from http://chembank.broad.harvard.edu/resources/. Source code is available upon request.

On Holo-Hilbert Spectral Analysis: A Full Informational Spectral Representation for Nonlinear and Non-Stationary Data

NASA Technical Reports Server (NTRS)

Huang, Norden E.; Hu, Kun; Yang, Albert C. C.; Chang, Hsing-Chih; Jia, Deng; Liang, Wei-Kuang; Yeh, Jia Rong; Kao, Chu-Lan; Juan, Chi-Huang; Peng, Chung Kang;

On Holo-Hilbert spectral analysis: a full informational spectral representation for nonlinear and non-stationary data

PubMed Central

Huang, Norden E.; Hu, Kun; Yang, Albert C. C.; Chang, Hsing-Chih; Jia, Deng; Liang, Wei-Kuang; Yeh, Jia Rong; Kao, Chu-Lan; Juan, Chi-Hung; Peng, Chung Kang; Meijer, Johanna H.; Wang, Yung-Hung; Long, Steven R.; Wu, Zhauhua

2016-01-01

The Holo-Hilbert spectral analysis (HHSA) method is introduced to cure the deficiencies of traditional spectral analysis and to give a full informational representation of nonlinear and non-stationary data. It uses a nested empirical mode decomposition and Hilbert–Huang transform (HHT) approach to identify intrinsic amplitude and frequency modulations often present in nonlinear systems. Comparisons are first made with traditional spectrum analysis, which usually achieved its results through convolutional integral transforms based on additive expansions of an a priori determined basis, mostly under linear and stationary assumptions. Thus, for non-stationary processes, the best one could do historically was to use the time–frequency representations, in which the amplitude (or energy density) variation is still represented in terms of time. For nonlinear processes, the data can have both amplitude and frequency modulations (intra-mode and inter-mode) generated by two different mechanisms: linear additive or nonlinear multiplicative processes. As all existing spectral analysis methods are based on additive expansions, either a priori or adaptive, none of them could possibly represent the multiplicative processes. While the earlier adaptive HHT spectral analysis approach could accommodate the intra-wave nonlinearity quite remarkably, it remained that any inter-wave nonlinear multiplicative mechanisms that include cross-scale coupling and phase-lock modulations were left untreated. To resolve the multiplicative processes issue, additional dimensions in the spectrum result are needed to account for the variations in both the amplitude and frequency modulations simultaneously. HHSA accommodates all the processes: additive and multiplicative, intra-mode and inter-mode, stationary and non-stationary, linear and nonlinear interactions. The Holo prefix in HHSA denotes a multiple dimensional representation with both additive and multiplicative capabilities. PMID:26953180

Expanded uncertainty estimation methodology in determining the sandy soils filtration coefficient

NASA Astrophysics Data System (ADS)

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.

[Review of digital ground object spectral library].

PubMed

Zhou, Xiao-Hu; Zhou, Ding-Wu

2009-06-01

A higher spectral resolution is the main direction of developing remote sensing technology, and it is quite important to set up the digital ground object reflectance spectral database library, one of fundamental research fields in remote sensing application. Remote sensing application has been increasingly relying on ground object spectral characteristics, and quantitative analysis has been developed to a new stage. The present article summarized and systematically introduced the research status quo and development trend of digital ground object reflectance spectral libraries at home and in the world in recent years. Introducing the spectral libraries has been established, including desertification spectral database library, plants spectral database library, geological spectral database library, soil spectral database library, minerals spectral database library, cloud spectral database library, snow spectral database library, the atmosphere spectral database library, rocks spectral database library, water spectral database library, meteorites spectral database library, moon rock spectral database library, and man-made materials spectral database library, mixture spectral database library, volatile compounds spectral database library, and liquids spectral database library. In the process of establishing spectral database libraries, there have been some problems, such as the lack of uniform national spectral database standard and uniform standards for the ground object features as well as the comparability between different databases. In addition, data sharing mechanism can not be carried out, etc. This article also put forward some suggestions on those problems.

Drilling fluid containing a copolymer filtration control agent

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

Lucas, J. M.

1985-10-15

The invention relates to an aqueous drilling fluid composition, a filtration control agent for utilization in said aqueous drilling fluid, and a method of forming a filter cake on the wall of a well for the reduction of filtrate from said drilling fluid, by utilization of a copolymer of: a (meth) acrylamido alkyl sulfonic acid or alkali metal salt thereof; and N, N-dialkyl (meth) acrylamide. The copolymer may be cross-linked with N,N'-methylenebisacrylamide or other appropriate cross-linking agent.

Continuous improvements of defectivity rates in immersion photolithography via functionalized membranes in point-of-use photochemical filtration

NASA Astrophysics Data System (ADS)

D'Urzo, Lucia; Bayana, Hareen; Vandereyken, Jelle; Foubert, Philippe; Wu, Aiwen; Jaber, Jad; Hamzik, James

2017-03-01

Specific "killer-defects", such as micro-line-bridges are one of the key challenges in photolithography's advanced applications, such as multi-pattern. These defects generate from several sources and are very difficult to eliminate. Pointof-use filtration (POU) plays a crucial role on the mitigation, or elimination, of such defects. Previous studies have demonstrated how the contribution of POU filtration could not be studied independently from photoresists design and track hardware settings. Specifically, we investigated how an effective combination of optimized photoresist, filtration rate, filtration pressure, membrane and device cleaning, and single and multilayer filter membranes at optimized pore size could modulate the occurrence of such defects [1, 2, 3 and 4]. However, the ultimate desired behavior for POU filtration is the selective retention of defect precursor molecules contained in commercially available photoresist. This optimal behavior can be achieved via customized membrane functionalization. Membrane functionalization provides additional non-sieving interactions which combined with efficient size exclusion can selectively capture certain defect precursors. The goal of this study is to provide a comprehensive assessment of membrane functionalization applied on an asymmetric ultra-high molecular weight polyethylene (UPE) membrane at different pore size. Defectivity transferred in a 45 nm line 55 nm space (45L/55S) pattern, created through 193 nm immersion (193i) lithography with a positive tone chemically amplified resist (PT-CAR), has been evaluated on organic under-layer coated wafers. Lithography performance, such as critical dimensions (CD), line width roughness (LWR) and focus energy matrix (FEM) is also assessed.

Filtration effectiveness of HVAC systems at near-roadway schools.

PubMed

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.

OPTICAL FIBRES AND FIBREOPTIC SENSORS: Fibreoptic distributed temperature sensor with spectral filtration by directional fibre couplers

NASA Astrophysics Data System (ADS)

Kuznetsov, A. G.; Babin, Sergei A.; Shelemba, Ivan S.

2009-11-01

We demonstrate a Raman-based all-fibre temperature sensor utilising a pulsed erbium fibre laser. The sensor is made of a standard single-mode telecom fibre, SMF-28, and includes a number of directional couplers as band-pass filters. The temperature profile along a 7-km fibreoptic line is measured with an accuracy of 2oC and a spatial resolution of 10 m. In data processing, we take into account the difference in attenuation between the spectral components of the backscatter signal.

Hyperspectral image classification by a variable interval spectral average and spectral curve matching combined algorithm

NASA Astrophysics Data System (ADS)

Senthil Kumar, A.; Keerthi, V.; Manjunath, A. S.; Werff, Harald van der; Meer, Freek van der

2010-08-01

Classification of hyperspectral images has been receiving considerable attention with many new applications reported from commercial and military sectors. Hyperspectral images are composed of a large number of spectral channels, and have the potential to deliver a great deal of information about a remotely sensed scene. However, in addition to high dimensionality, hyperspectral image classification is compounded with a coarse ground pixel size of the sensor for want of adequate sensor signal to noise ratio within a fine spectral passband. This makes multiple ground features jointly occupying a single pixel. Spectral mixture analysis typically begins with pixel classification with spectral matching techniques, followed by the use of spectral unmixing algorithms for estimating endmembers abundance values in the pixel. The spectral matching techniques are analogous to supervised pattern recognition approaches, and try to estimate some similarity between spectral signatures of the pixel and reference target. In this paper, we propose a spectral matching approach by combining two schemes—variable interval spectral average (VISA) method and spectral curve matching (SCM) method. The VISA method helps to detect transient spectral features at different scales of spectral windows, while the SCM method finds a match between these features of the pixel and one of library spectra by least square fitting. Here we also compare the performance of the combined algorithm with other spectral matching techniques using a simulated and the AVIRIS hyperspectral data sets. Our results indicate that the proposed combination technique exhibits a stronger performance over the other methods in the classification of both the pure and mixed class pixels simultaneously.

Dynamic Optical Filtration

NASA Technical Reports Server (NTRS)

Chretien, Jean-Loup (Inventor); Lu, Edward T. (Inventor)

2005-01-01

A dynamic optical filtration system and method effectively blocks bright light sources without impairing view of the remainder of the scene. A sensor measures light intensity and position so that selected cells of a shading matrix may interrupt the view of the bright light source by a receptor. A beamsplitter may be used so that the sensor may be located away from the receptor. The shading matrix may also be replaced by a digital micromirror device, which selectively sends image data to the receptor.

Dynamic optical filtration

NASA Technical Reports Server (NTRS)

Chretien, Jean-Loup (Inventor); Lu, Edward T. (Inventor)

2005-01-01

A dynamic optical filtration system and method effectively blocks bright light sources without impairing view of the remainder of the scene. A sensor measures light intensity and position so that selected cells of a shading matrix may interrupt the view of the bright light source by a receptor. A beamsplitter may be used so that the sensor may be located away from the receptor. The shading matrix may also be replaced by a digital micromirror device, which selectively sends image data to the receptor.

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

PubMed

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.

High speed parallel spectral-domain OCT using spectrally encoded line-field illumination

NASA Astrophysics Data System (ADS)

Lee, Kye-Sung; Hur, Hwan; Bae, Ji Yong; Kim, I. Jong; Kim, Dong Uk; Nam, Ki-Hwan; Kim, Geon-Hee; Chang, Ki Soo

2018-01-01

We report parallel spectral-domain optical coherence tomography (OCT) at 500 000 A-scan/s. This is the highest-speed spectral-domain (SD) OCT system using a single line camera. Spectrally encoded line-field scanning is proposed to increase the imaging speed in SD-OCT effectively, and the tradeoff between speed, depth range, and sensitivity is demonstrated. We show that three imaging modes of 125k, 250k, and 500k A-scan/s can be simply switched according to the sample to be imaged considering the depth range and sensitivity. To demonstrate the biological imaging performance of the high-speed imaging modes of the spectrally encoded line-field OCT system, human skin and a whole leaf were imaged at the speed of 250k and 500k A-scan/s, respectively. In addition, there is no sensitivity dependence in the B-scan direction, which is implicit in line-field parallel OCT using line focusing of a Gaussian beam with a cylindrical lens.

Effects of aluminum-copper alloy filtration on photon spectra, air kerma rate and image contrast.

PubMed

Gonçalves, Andréa; Rollo, João Manuel Domingos de Almeida; Gonçalves, Marcelo; Haiter Neto, Francisco; Bóscolo, Frab Norberto

2004-01-01

This study evaluated the performance of aluminum-copper alloy filtration, without the original aluminum filter, for dental radiography in terms of x-ray energy spectrum, air kerma rate and image quality. Comparisons of various thicknesses of aluminum-copper alloy in three different percentages were made with aluminum filtration. Tests were conducted on an intra-oral dental x-ray machine and were made on mandible phantom and on step-wedge. Depending on the thickness of aluminum-copper alloy filtration, the beam could be hardened and filtrated. The use of the aluminum-copper alloy filter resulted in reductions in air kerma rate from 8.40% to 47.33%, and indicated the same image contrast when compared to aluminum filtration. Aluminum-copper alloy filtration may be considered a good alternative to aluminum filtration.

Fabrication of a multi-walled carbon nanotube-deposited glass fiber air filter for the enhancement of nano and submicron aerosol particle filtration and additional antibacterial efficacy.

PubMed

Park, Jae Hong; Yoon, Ki Young; Na, Hyungjoo; Kim, Yang Seon; Hwang, Jungho; Kim, Jongbaeg; Yoon, Young Hun

2011-09-01

We grew multi-walled carbon nanotubes (MWCNTs) on a glass fiber air filter using thermal chemical vapor deposition (CVD) after the filter was catalytically activated with a spark discharge. After the CNT deposition, filtration and antibacterial tests were performed with the filters. Potassium chloride (KCl) particles (<1 μm) were used as the test aerosol particles, and their number concentration was measured using a scanning mobility particle sizer. Antibacterial tests were performed using the colony counting method, and Escherichia coli (E. coli) was used as the test bacteria. The results showed that the CNT deposition increased the filtration efficiency of nano and submicron-sized particles, but did not increase the pressure drop across the filter. When a pristine glass fiber filter that had no CNTs was used, the particle filtration efficiencies at particle sizes under 30 nm and near 500 nm were 48.5% and 46.8%, respectively. However, the efficiencies increased to 64.3% and 60.2%, respectively, when the CNT-deposited filter was used. The reduction in the number of viable cells was determined by counting the colony forming units (CFU) of each test filter after contact with the cells. The pristine glass fiber filter was used as a control, and 83.7% of the E. coli were inactivated on the CNT-deposited filter. Copyright © 2011 Elsevier B.V. All rights reserved.

Improving IAQ Via Air Filtration.

ERIC Educational Resources Information Center

Monk, Brian

1999-01-01

Provides tips on using air filtration to control indoor air quality in educational facilities, including dedicated spaces with unique air quality conditions such as in libraries, museums and archival storage areas, kitchens and dining areas, and laboratories. The control of particulate contaminants, gaseous contaminants, and moisture buildup are…

Oxidation Resistance, Electrical and Thermal Conductivity, and Spectral Emittance of Fully Dense HfB2 and ZrB2 with SiC, TaSi2, and LaB6 Additives

DTIC Science & Technology

2012-01-26

Resistance , Electrical and Thermal Conductivity, and Spectral Emittance of Fully Dense HfB2 and ZrB2 "With SiC, TaSi2, and LaB6 Additives Sb. GRANT NUMBER... RESISTANCE , ELECTRICAL AND THERMAL CONDUCTIVITY, AND SPECTRAL EMITTANCE OF FULLY DENSE HfB2 AND ZrB2 WITH SiC, TaSi2, AND LaB6 ADDITIVES Air Force Office...thickened regions with dry 220 grit SiC sandpaper so that a low- resistance electrical connection could be achieved. A handheld multimeter was used to measure

Drilling fluid containing a copolymer filtration control agent

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

Enright, D.P.; Lucas, J.M.; Perricone, A.C.

1981-10-06

The invention relates to an aqueous drilling fluid composition, a filtration control agent for utilization in said aqueous drilling fluid, and a method of forming a filter cake on the wall of a well for the reduction of filtrate from said drilling fluid, by utilization of a copolymer of: (1) a (Meth) acrylamido alkyl sulfonic acid or alkali metal salt thereof; and (2) a (Meth) acrylamide or n-alkyl (Meth) acrylamide. The copolymer may be cross-linked with a quaternary ammonium salt cross-linking agent.

Use of hollow fiber membrane filtration for the removal of DMSO from platelet concentrates.

PubMed

Arnaud, F; Kapnik, E; Meryman, H T

2003-05-01

It has been hypothesized that, in addition to freezing injury, some damage to platelets may result from the cell packing that occurs during removal of the cryoprotectant. This study examined DMSO removal by fluid exchange across hollow-fiber (HF) filters as an alternative to centrifugation. The DMSO solution with or without cell suspension was passed once through the filter. The optimum exchange during unloading of DMSO was determined by varying the flow rates in the external and internal compartments of the HF filter. Initially, buffered solutions of a 5% DMSO solution in the absence of platelets were pumped into the fibers and exchanged against PBS. The residual DMSO was determined by osmometry. The exchange of DMSO across the membrane was flow dependent and also influenced by the chemical nature of the HF fibers. No protocol using a reasonable rate flow through the fibers removed more than 95% of the DMSO in a single pass. The optimum protocol was achieved with polysynthane fibers with an internal flow rate of approximately 20 mi/min and an external flow rate of 100 ml/min. Subsequently, frozen/thawed platelet concentrates in DMSO were washed using centrifugation and compared to the HF filtration method. Platelet quality was assayed by flow cytometry, cell count, morphology and osmotic stress test. Both filtration and centrifugal washing techniques resulted in comparable morphological scores and numbers of discoid cells. When agents reducing platelet activation were added, platelet quality was improved after washing by either technique. The lower platelet osmotic response with HF filtration than with centrifugation while using activation inhibitors was attributed to the remaining amount of the inhibitors. All other parameters tested were similar. The expression of CD62P was equivalent with both techniques, and centrifugation did not activate platelets more than filtration contrary to what was originally anticipated. In conclusion, platelet quality was comparable

An integrated wastewater reuse concept combining natural reclamation techniques, membrane filtration and metal oxide adsorption.

PubMed

Sperlich, A; Zheng, X; Ernst, M; Jekel, M

2008-01-01

In a Sino-German research project, a sustainable water reclamation concept was developed for different applications of municipal water reuse at the Olympic Green 2008 in Beijing, China. Results from pilot-scale experiments in Beijing and Berlin show that selective nutrient removal by adsorption onto granular ferric hydroxide (GFH) after a membrane bioreactor (MBR) can maintain a total phosphorus concentration of <0.03 microg L(-1) P, thus preventing eutrophication of artificial lakes. Operation time of GFH adsorption columns can be extended by regeneration using sodium hydroxide solution. A subsequent ultrafiltration (UF) membrane after bank filtration creates an additional barrier for pathogens and allows for further urban reuse applications such as toilet flushing. Short term bank / bio-filtration prior to UF is shown to effectively remove biopolymers and reduce membrane fouling. Copyright IWA Publishing 2008.

The effect of membrane filtration artifacts on dissolved trace element concentrations

USGS Publications Warehouse

Horowitz, A.J.; Elrick, K.A.; Colberg, M.R.

1992-01-01

Among environment scientists, the current and almost universally accepted definition of dissolved constituents is an operational one only those materials which pass through a 0.45-??m membrane filter are considered to be dissolved. Detailed laboratory and field studies on Fe and Al indicate that a number of factors associated with filtration, other than just pore size, can substantially alter 'dissolved' trace element concentrations; these include: filter type, filter diameter, filtration method, volume of sample processed, suspended sediment concentration, suspended sediment grain-size distribution, concentration of colloids and colloidally-associated trace elements and concentration of organic matter. As such, reported filtered-water concentrations employing the same pore size filter may not be equal. Filtration artifacts may lead to the production of chemical data that indicate seasonal or annual 'dissolved' chemical trends which do not reflect actual environmental conditions. Further, the development of worldwide averages for various dissolved chemical constituents, the quantification of geochemical cycles, and the determination of short- or long-term environmental chemical trends may be subject to substantial errors, due to filtration artifacts, when data from the same or multiple sources are combined. Finally, filtration effects could have a substantial impact on various regulatory requirements.

The effect of entomopathogenic fungal culture filtrate on the immune response of the greater wax moth, Galleria mellonella.

PubMed

Mc Namara, Louise; Carolan, James C; Griffin, Christine T; Fitzpatrick, David; Kavanagh, Kevin

2017-07-01

Galleria mellonella is a well-established model species regularly employed in the study of the insect immune response at cellular and humoral levels to investigate fungal pathogenesis and biocontrol agents. A cellular and proteomic analysis of the effect of culture filtrate of three entomopathogenic fungi (EPF) species on the immune system of G. mellonella was performed. Treatment with Beauveria caledonica and Metarhizium anisopliae 96h culture filtrate facilitated a significantly increased yeast cell density in larvae (3-fold and 3.8-fold, respectively). Larvae co-injected with either M. anisopliae or B. caledonica culture filtrate and Candida albicans showed significantly increased mortality. The same was not seen for larvae injected with Beauveria bassiana filtrate. Together these results suggest that B. caledonica and M. anisopliae filtrate are modulating the insect immune system allowing a subsequent pathogen to proliferate. B. caledonica and M. anisopliae culture filtrates impact upon the larval prophenoloxidase (ProPO) cascade (e.g. ProPO activating factor 3 and proPO activating enzyme 3 were increased in abundance relative to controls), while B. bassiana treated larvae displayed higher abundances of alpha-esterase when compared to control larvae (2.4-fold greater) and larvae treated with M. anisopliae and B. caledonica. Treatment with EPF culture filtrate had a significant effect on antimicrobial peptide abundances particularly in M. anisopliae treated larvae where cecropin-D precursor, hemolin and gloverin were differentially abundant in comparison to controls. Differences in proteomic profiles for different treatments may reflect or even partially explain the differences in their immunomodulatory potential. Screening EPF for their ability to modulate the insect immune response represents a means of assessing EPF for use as biocontrol agents, particularly if the goal is to use them in combination with other control agents. Additionally EPF represent a

Sioux City Riverbank Filtration Study

NASA Astrophysics Data System (ADS)

Mach, R.; Condon, J.; Johnson, J.

2003-04-01

The City of Sioux City (City) obtains a large percentage of their drinking water supply from both a horizontal collector well system and vertical wells located adjacent to the Missouri River. These wells are set in either the Missouri Alluvium or the Dakota Sandstone aquifer. Several of the collector well laterals extend out beneath the Missouri River, with the laterals being over twenty feet below the river channel bottom. Due to concerns regarding ground water under direct surface water influence, the Iowa Department of Natural Resources (IDNR) required the City to expand their water treatment process to deal with potential surface water contaminant issues. With the extensive cost of these plant upgrades, the City and Olsson Associates (OA) approached the IDNR requesting approval for assessing the degree of natural riverbank filtration for water treatment. If this natural process could be ascertained, the level of treatment from the plant could be reduced. The objective of this study was to quantify the degree of surface water (i.e. Missouri River) filtration due to the underlying Missouri River sediments. Several series of microscopic particulate analysis where conducted, along with tracking of turbidity, temperature, bacteria and a full scale particle count study. Six particle sizes from six sampling points were assessed over a nine-month period that spanned summer, fall and spring weather periods. The project was set up in two phases and utilized industry accepted statistical analyses to identify particle data trends. The first phase consisted of twice daily sample collection from the Missouri River and the collector well system for a one-month period. Statistical analysis of the data indicated reducing the sampling frequency and sampling locations would yield justifiable data while significantly reducing sampling and analysis costs. The IDNR approved this modification, and phase II included sampling and analysis under this reduced plant for an eight

Combination of granular activated carbon adsorption and deep-bed filtration as a single advanced wastewater treatment step for organic micropollutant and phosphorus removal.

PubMed

Altmann, Johannes; Rehfeld, Daniel; Träder, Kai; Sperlich, Alexander; Jekel, Martin

2016-04-01

Adsorption onto granular activated carbon (GAC) is an established technology in water and advanced wastewater treatment for the removal of organic substances from the liquid phase. Besides adsorption, the removal of particulate matter by filtration and biodegradation of organic substances in GAC contactors has frequently been reported. The application of GAC as both adsorbent for organic micropollutant (OMP) removal and filter medium for solids retention in tertiary wastewater filtration represents an energy- and space saving option, but has rarely been considered because high dissolved organic carbon (DOC) and suspended solids concentrations in the influent of the GAC adsorber put a significant burden on this integrated treatment step and might result in frequent backwashing and unsatisfactory filtration efficiency. This pilot-scale study investigates the combination of GAC adsorption and deep-bed filtration with coagulation as a single advanced treatment step for simultaneous removal of OMPs and phosphorus from secondary effluent. GAC was assessed as upper filter layer in dual-media downflow filtration and as mono-media upflow filter with regard to filtration performance and OMP removal. Both filtration concepts effectively removed suspended solids and phosphorus, achieving effluent concentrations of 0.1 mg/L TP and 1 mg/L TSS, respectively. Analysis of grain size distribution and head loss within the filter bed showed that considerable head loss occurred in the topmost filter layer in downflow filtration, indicating that most particles do not penetrate deeply into the filter bed. Upflow filtration exhibited substantially lower head loss and effective utilization of the whole filter bed. Well-adsorbing OMPs (e.g. benzotriazole, carbamazepine) were removed by >80% up to throughputs of 8000-10,000 bed volumes (BV), whereas weakly to medium adsorbing OMPs (e.g. primidone, sulfamethoxazole) showed removals <80% at <5,000 BV. In addition, breakthrough behavior was

Evaluation of Side Stream Filtration Technology at Oak Ridge National Laboratory

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

Boyd, Brian K.

2014-08-01

This technology evaluation was performed by Pacific Northwest National Laboratory and Oak Ridge National Laboratory on behalf of the Federal Energy Management Program. The objective was to quantify the benefits side stream filtration provides to a cooling tower system. The evaluation assessed the performance of an existing side stream filtration system at a cooling tower system at Oak Ridge National Laboratory’s Spallation Neutron Source research facility. This location was selected because it offered the opportunity for a side-by-side comparison of a system featuring side stream filtration and an unfiltered system.

Fine dust filtration using a metal fiber bed.

PubMed

Lee, Kyung Mi; Lee, Young Sup; Jo, Young Min

2006-08-01

A bed-type filter composed of thin metal alloy fiber was closely examined with dust capturing in cold and hot runs. The investigation of an individual mechanism across the filter bed indicated that the aerated dust could be initially collected by depth filtration, and after a while, surface filtration dominated the overall dust collection. The present metal fiber bed was comparable to the conventional ceramic filters because of its good collection efficiency with low pressure drop. It also showed potential to be used as a prefilter in a diesel exhaust trapping system.

Successful treatment of homozygous familial hypercholesterolemia using cascade filtration plasmapheresis.

PubMed

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.

Removal of Inclusions from Molten Aluminum by Supergravity Filtration

NASA Astrophysics Data System (ADS)

Song, Gaoyang; Song, Bo; Yang, Zhanbing; Yang, Yuhou; Zhang, Jing

2016-12-01

A new approach to removing inclusions from aluminum melt by supergravity filtration was investigated. The molten aluminum containing MgAl2O4 spinel and coarse Al3Ti particles was isothermally filtered with different gravity coefficients, different filtering times, and various filtering temperatures under supergravity field. When the gravity coefficient G ≥ 50, the alloy samples were divided automatically into two parts: the upper residue and the lower filtered aluminum. All inclusions (MgAl2O4 and Al3Ti particles) were nearly intercepted in the upper residue by filter felt with average pore size of 44.78 μm. The removal efficiencies of oxide inclusions and Al3Ti particles exceeded 98 and 90 pct, respectively, at G ≥ 50, t = 2 minutes, T = 973 K (700 °C). Besides, the yield of purified aluminum was up to 92.1 pct at G = 600, t = 2 minutes, and T = 973 K (700 °C). The calculations of centrifugal pressure indicated that supergravity filtration could effectively overcome the pressure drop without meeting the rigorous requirement of height of molten metal, especially for using the fine-pore filter medium. Moreover, cake-mode filtration was the major mechanism of supergravity filtration of molten metal in this work.

IMPACT OF WATER CHEMISTRY ON MANGANESE REMOVAL DURING OXIDATION/FILTRATION TREATMENT

EPA Science Inventory

This is a poster showing the purpose and setup of our pilot plant experiments with manganese filtration. The focus is on the differences, effectiveness, and problems with using chlorine and potassium permanganate in oxidation/filtration. The poster will show the results and findi...

SpectralNET – an application for spectral graph analysis and visualization

PubMed Central

Forman, Joshua J; Clemons, Paul A; Schreiber, Stuart L; Haggarty, Stephen J

2005-01-01

Background Graph theory provides a computational framework for modeling a variety of datasets including those emerging from genomics, proteomics, and chemical genetics. Networks of genes, proteins, small molecules, or other objects of study can be represented as graphs of nodes (vertices) and interactions (edges) that can carry different weights. SpectralNET is a flexible application for analyzing and visualizing these biological and chemical networks. Results Available both as a standalone .NET executable and as an ASP.NET web application, SpectralNET was designed specifically with the analysis of graph-theoretic metrics in mind, a computational task not easily accessible using currently available applications. Users can choose either to upload a network for analysis using a variety of input formats, or to have SpectralNET generate an idealized random network for comparison to a real-world dataset. Whichever graph-generation method is used, SpectralNET displays detailed information about each connected component of the graph, including graphs of degree distribution, clustering coefficient by degree, and average distance by degree. In addition, extensive information about the selected vertex is shown, including degree, clustering coefficient, various distance metrics, and the corresponding components of the adjacency, Laplacian, and normalized Laplacian eigenvectors. SpectralNET also displays several graph visualizations, including a linear dimensionality reduction for uploaded datasets (Principal Components Analysis) and a non-linear dimensionality reduction that provides an elegant view of global graph structure (Laplacian eigenvectors). Conclusion SpectralNET provides an easily accessible means of analyzing graph-theoretic metrics for data modeling and dimensionality reduction. SpectralNET is publicly available as both a .NET application and an ASP.NET web application from . Source code is available upon request. PMID:16236170

Effects of pore pressure and mud filtration on drilling rates in a permeable sandstone

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

Black, A.D.; DiBona, B.; Sandstrom, J.

1983-10-01

During laboratory drilling tests in a permeable sandstone, the effects of pore pressure and mud filtration on penetration rates were measured. Four water-base muds were used to drill four saturated sandstone samples. The drilling tests were conducted at constant borehole pressure with different back pressures maintained on the filtrate flowing from the bottom of the sandstone samples. Bit weight was also varied. Filtration rates were measured while drilling and with the bit off bottom and mud circulating. Penetration rates were found to be related to the difference between the filtration rates measured while drilling and circulating. There was no observedmore » correlation between standard API filtration measurements and penetration rate.« less

Effects of pore pressure and mud filtration on drilling rates in a permeable sandstone

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

Black, A.D.; Dearing, H.L.; DiBona, B.G.

1985-09-01

During laboratory drilling tests in a permeable sandstone, the effects of pore pressure and mud filtration on penetration rates were measured. Four water-based muds were used to drill four saturated sandstone samples. The drilling tests were conducted at constant borehole pressure while different backpressures were maintained on the filtrate flowing from the bottom of the sandstone samples. Bit weight was varied also. Filtration rates were measured while circulating mud during drilling and with the bit off bottom. Penetration rates were found to be related qualitatively to the difference between the filtration rates measured while drilling and circulating. There was nomore » observed correlation between standard API filtration measurements and penetration rate.« less

Modeling the filtration ability of stockpiled filtering facepiece

NASA Astrophysics Data System (ADS)

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.

Removal of geosmin and 2-methylisoborneol by biological filtration.

PubMed

Elhadi, S L N; Huck, P M; Slawson, R M

2004-01-01

The quality of drinking water is sometimes diminished by the presence of certain compounds that can impart particular tastes or odours. One of the most common and problematic types of taste and odour is the earthy/musty odour produced by geosmin (trans-1, 10-dimethyl-trans-9-decalol) and MIB (2-methylisoborneol). Taste and odour treatment processes including powdered activated carbon, and oxidation using chlorine, chloramines, potassium permanganate, and sometimes even ozone are largely ineffective for reducing these compounds to below their odour threshold concentration levels. Ozonation followed by biological filtration, however, has the potential to provide effective treatment. Ozone provides partial removal of geosmin and MIB but also creates other compounds more amenable to biodegradation and potentially undesirable biological instability. Subsequent biofiltration can remove residual geosmin and MIB in addition to removing these other biodegradable compounds. Bench scale experiments were conducted using two parallel filter columns containing fresh and exhausted granular activated carbon (GAC) media and sand. Source water consisted of dechlorinated tap water to which geosmin and MIB were added, as well as, a cocktail of easily biodegradable organic matter (i.e. typical ozonation by-products) in order to simulate water that had been subjected to ozonation prior to filtration. Using fresh GAC, total removals of geosmin ranged from 76 to 100% and total MIB removals ranged from 47% to 100%. The exhausted GAC initially removed less geosmin and MIB but removals increased over time. Overall the results of these experiments are encouraging for the use of biofiltration following ozonation as a means of geosmin and MIB removal. These results provide important information with respect to the role biofilters play during their startup phase in the reduction of these particular compounds. In addition, the results demonstrate the potential biofilters have in responding to

Perchlorate Destruction and Potable Water Production Using Membrane Biofilm Reduction and Membrane Filtration

DTIC Science & Technology

2013-11-18

the experimental filter media Next-SandTM was used, thus turbidity results may not be translatable to conventional filtration media. The media...performance objective was not met. Further optimization of the media filtration process would result in meeting the objective. Dissolved Organic Carbon...FINAL REPORT Perchlorate Destruction and Potable Water Production Using Membrane Biofilm Reduction and Membrane Filtration ESTCP Project ER

Acoustic filtration and sedimentation of soot particles

NASA Astrophysics Data System (ADS)

Martin, K. M.; Ezekoye, O. A.

Removal of soot particles from a static chamber by an intense acoustic field is investigated. Combustion of a solid fuel fills a rectangular chamber with small soot particles, which sediment very slowly. The chamber is then irradiated by an intense acoustic source to produce a three dimensional standing wave field in the chamber. The acoustic excitation causes the soot particles to agglomerate, forming larger particles which sediment faster from the system. The soot also forms 1-2 cm disks, with axes parallel to the axis of the acoustic source, which are levitated by the sound field at half-wavelength spacing within the chamber. Laser extinction measurements are made to determine soot volume fractions as a function of exposure time within the chamber. The volume fraction is reduced over time by sedimentation and by particle migration to the disks. The soot disks are considered to be a novel mechanism for particle removal from the air stream, and this mechanism has been dubbed acoustic filtration. An experimental method is developed for comparing the rate of soot removal by sedimentation alone with the rate of soot removal by sedimentation and acoustic filtration. Results show that acoustic filtration increases the rate of soot removal by a factor of two over acoustically-induced sedimentation alone.

40 CFR 141.73 - Filtration.

Code of Federal Regulations, 2014 CFR

2014-07-01

... turbidity level of representative samples of a system's filtered water must be less than or equal to 0.5 NTU....74 (a)(1) and (c)(1). (2) The turbidity level of representative samples of a system's filtered water... filtration, the turbidity level of representative samples of a system's filtered water must be less than or...

Spectral and spread-spectral teleportation

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

Humble, Travis S.

2010-06-15

We report how quantum information encoded into the spectral degree of freedom of a single-photon state may be teleported using a finite spectrally entangled biphoton state. We further demonstrate how the bandwidth of the teleported wave form can be controllably and coherently dilated using a spread-spectral variant of teleportation. We calculate analytical expressions for the fidelities of spectral and spread-spectral teleportation when complex-valued Gaussian states are transferred using a proposed experimental approach. Finally, we discuss the utility of these techniques for integrating broad-bandwidth photonic qubits with narrow-bandwidth receivers in quantum communication systems.

Transport of Cryptosporidium oocysts in porous media: Role of straining and physicochemical filtration

USGS Publications Warehouse

Tufenkji, N.; Miller, G.F.; Ryan, J.N.; Harvey, R.W.; Elimelech, M.

2004-01-01

The transport and filtration behavior of Cryptosporidium parvum oocysts in columns packed with quartz sand was systematically examined under repulsive electrostatic conditions. An increase in solution ionic strength resulted in greater oocyst deposition rates despite theoretical predictions of a significant electrostatic energy barrier to deposition. Relatively high deposition rates obtained with both oocysts and polystyrene latex particles of comparable size at low ionic strength (1 mM) suggest that a physical mechanism may play a key role in oocyst removal. Supporting experiments conducted with latex particles of varying sizes, under very low ionic strength conditions where physicochemical filtration is negligible, clearly indicated that physical straining is an important capture mechanism. The results of this study indicate that irregularity of sand grain shape (verified by SEM imaging) contributes considerably to the straining potential of the porous medium. Hence, both straining and physicochemical filtration are expected to control the removal of C. parvum oocysts in settings typical of riverbank filtration, soil infiltration, and slow sand filtration. Because classic colloid filtration theory does not account for removal by straining, these observations have important implications with respect to predictions of oocyst transport.

EX-PRESS Glaucoma Filtration Device: efficacy, safety, and predictability

PubMed Central

Chan, Jessica E; Netland, Peter A

2015-01-01

Trabeculectomy has been the traditional primary surgical therapy for open-angle glaucoma. While trabeculectomy is effective in lowering intraocular pressure, complications associated with the procedure have motivated the development of alternative techniques and devices, including the EX-PRESS Glaucoma Filtration Device. This review describes the efficacy, safety, complication rates, and potential advantages and disadvantages of the EX-PRESS Glaucoma Filtration Device. EX-PRESS implantation is technically simpler compared with that of trabeculectomy, with fewer surgical steps. Vision recovery has been more rapid after EX-PRESS implantation compared with trabeculectomy. Intraocular pressure variation is lower during the early postoperative period, indicating a more predictable procedure. While efficacy of the EX-PRESS implant has been comparable to trabeculectomy, postoperative complications appear less common after EX-PRESS implantation compared with trabeculectomy. The EX-PRESS Glaucoma Filtration Device appears to be safe and effective in the surgical management of open-angle glaucoma. PMID:26366105

Impacts of extreme flooding on riverbank filtration water quality.

PubMed

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) <90% baseline, high dissolved oxygen (DO) >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

Filtration effects on ball bearing life and condition in a contaminated lubricant

NASA Technical Reports Server (NTRS)

Loewenthal, S. H.; Moyer, D. W.

1978-01-01

Ball bearings were fatigue tested with a noncontaminated lubricant and with a contaminated lubricant under four levels of filtration. The test filters had absolute particle removal ratings of 3, 30, 49, and 105 microns. Aircraft turbine engine contaminants were injected into the filter's supply line at a constant rate of 125 milligrams per bearing hour. Bearing life and running track condition generally improved with finer filtration. The experimental lives of 3 and 30 micron filter bearings were statistically equivalent, approaching those obtained with the noncontaminated lubricant bearings. Compared to these bearings, the lives of the 49 micron bearings were statistically lower. The 105 micron bearings experienced gross wear. The degree of surface distress, weight loss, and probable failure mode were dependent on filtration level, with finer filtration being clearly beneficial.

Doppler imaging using spectrally-encoded endoscopy

PubMed Central

Yelin, Dvir; Bouma, B. E.; Rosowsky, J. J.; Tearney, G. J.

2009-01-01

The capability to image tissue motion such as blood flow through an endoscope could have many applications in medicine. Spectrally encoded endoscopy (SEE) is a recently introduced technique that utilizes a single optical fiber and miniature diffractive optics to obtain endoscopic images through small diameter probes. Using spectral-domain interferometry, SEE is furthermore capable of three-dimensional volume imaging at video rates. Here we show that by measuring relative spectral phases, this technology can additionally measure Doppler shifts. Doppler SEE is demonstrated in flowing Intralipid phantoms and vibrating middle ear ossicles. PMID:18795020

Preparation and characterization of novel PVDF nanofiltration membranes with hydrophilic property for filtration of dye aqueous solution

NASA Astrophysics Data System (ADS)

Nikooe, Naeme; Saljoughi, Ehsan

2017-08-01

In the present research, for the first time PVDF/Brij-58 blend nanofiltration membranes with remarkable performance in filtration of dye aqueous solution were prepared via immersion precipitation. A noticeable improvement in water permeation and fouling resistance of the PVDF membranes was achieved by using Brij-58 surfactant as a hydrophilic additive. Scanning electron microscopy (SEM), fourier transform infrared spectroscopy (FT-IR) and water contact angle were applied for the investigation of membrane morphology, detection of the surface chemical composition and relative hydrophilicity/hydrophobicity, respectively. The membrane performance was studied and compared by determination of pure water flux (PWF) and filtration of synthetic reactive dye aqueous solutions as well as bovine serum albumin (BSA) as foulant model. It was found out that addition of 4 wt.% Brij-58 to the casting solution results in formation of membrane with remarkable hydrophilicity and fouling resistance (contact angle of 46° and flux recovery ratio (FRR) = 90%), higher porosity and consequently noticeable PWF (31.2 L/m2 h) and recognized dye rejection value (90%) in comparison with the pristine PVDF nanofiltration membrane. Addition of Brij-58 surfactant to the casting solution resulted in formation of NF membrane with higher hydrophilicity and permeability as well as higher dye rejection value in comparison with the addition of PEG 400 additive.

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

Code of Federal Regulations, 2014 CFR

2014-04-01

... 21 Food and Drugs 4 2014-04-01 2014-04-01 false Ventilation, air filtration, air heating and... Buildings and Facilities § 211.46 Ventilation, air filtration, air heating and cooling. (a) Adequate ventilation shall be provided. (b) Equipment for adequate control over air pressure, micro-organisms, dust...

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

Code of Federal Regulations, 2013 CFR

2013-04-01

... 21 Food and Drugs 4 2013-04-01 2013-04-01 false Ventilation, air filtration, air heating and... Buildings and Facilities § 211.46 Ventilation, air filtration, air heating and cooling. (a) Adequate ventilation shall be provided. (b) Equipment for adequate control over air pressure, micro-organisms, dust...

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

Code of Federal Regulations, 2012 CFR

2012-04-01

... 21 Food and Drugs 4 2012-04-01 2012-04-01 false Ventilation, air filtration, air heating and... Buildings and Facilities § 211.46 Ventilation, air filtration, air heating and cooling. (a) Adequate ventilation shall be provided. (b) Equipment for adequate control over air pressure, micro-organisms, dust...

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

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 4 2011-04-01 2011-04-01 false Ventilation, air filtration, air heating and... Buildings and Facilities § 211.46 Ventilation, air filtration, air heating and cooling. (a) Adequate ventilation shall be provided. (b) Equipment for adequate control over air pressure, micro-organisms, dust...

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

ERIC Educational Resources Information Center

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…

Selective factors governing in vitro β-carotene bioaccessibility: negative influence of low filtration cutoffs and alterations by emulsifiers and food matrices.

PubMed

Corte-Real, Joana; Richling, Elke; Hoffmann, Lucien; Bohn, Torsten

2014-12-01

Because of their putative health benefits, the biological fate of carotenoids after digestion has been met with much interest, and ex vivo methods using carotenoid standards to study their digestion and further metabolism have been developed. In the absence of a complex food matrix, that is, when studying isolated carotenoids, protocol conditions of gastrointestinal digestion models have to be adjusted. In this investigation, we hypothesized that certain selected factors would significantly influence the bioaccessibility of β-carotene in vitro. The factors considered included (i) type of lipid matrix employed (milk, cream, or oil), (ii) presence/absence of emulsifiers (e.g. lecithin and taurocholate), (iii) addition of a gastric lipase, and (iv) final filtration (20 or 200 nm) of the digesta. Adding an emulsifier mixture (10 mg lecithin + 50 mg monoolein + 5 mg oleic acid) enhanced β-carotene bioaccessibility 3 times (P < 0.001), whereas additional taurocholate and the presence/absence of gastric lipase added before intestinal digestion had no significant effect. β-Carotene bioaccessibility was superior with oil than with milk (18.8% ± 0.7% and 6.1% ± 0.7%, respectively; P = 0.03), especially after filtration, thus suggesting incomplete micelle formation after addition of milk. Filtration through 20 nm filters reduced carotenoid concentration in the aqueous fraction (from 7.1% ± 0.2% to 5.5% ± 0.2% in samples digested with canola oil, P < 0.001), indicating that not all formed micelles compared in size with those normally formed in vivo. When studying carotenoid standards during in vitro digestion, care should be taken to separate mixed micelles by filtration, and the choice of emulsifier and matrix should be considered. Copyright © 2014 Elsevier Inc. All rights reserved.

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

Treesearch

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)...

Cellular proliferation after experimental glaucoma filtration surgery

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

Jampel, H.D.; McGuigan, L.J.; Dunkelberger, G.R.

1988-01-01

We used light microscopic autoradiography to determine the time course of cellular incorporation of tritiated thymidine (a correlate of cell division) following glaucoma filtration surgery in seven eyes of four cynomolgus monkeys with experimental glaucoma. Incorporation of tritiated thymidine was detected as early as 24 hours postoperatively. Peak incorporation occurred five days postoperatively and had returned to baseline levels by day 11. Cells incorporating tritiated thymidine included keratocytes, episcleral cells, corneal and capillary endothelial cells, and conjunctival and corneal epithelial cells. Transmission electron microscopy was correlated with the autoradiographic results to demonstrate that fibroblasts were dividing on the corneoscleral margin.more » These findings have potential clinical implications for the use of antiproliferative agents after filtration surgery.« less

Some aspects of applying nanostructured materials in air filtration, water filtration and electrical engineering

NASA Astrophysics Data System (ADS)

Kimmer, Dusan; Vincent, Ivo; Lovecka, Lenka; Kazda, Tomas; Giurg, Adam; Skorvan, Ondrej

2017-05-01

Nanostructures prepared from nanofibres and nanostructured composites prepared from nanofibres and fillers are gradually becoming increasingly demanded materials for applications in various industrial branches connected with catalysis, environment protection (air filtration, waste water treatment, sound absorption), in biological engineering, electronics (battery separators, electrode materials), etc. Selected applications of these materials prepared in the company SPUR a.s. are summed up in the following presentation.

Demonstrated technology for high-rate filtration of oily wastes

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

Danzberger, A.H.; Nebolsine, R.

1980-01-01

A discussion covers the various techniques (gravity separation, air or gas flotation, and ultrafiltration) used to remove oil from wastewater; their relative advantages; the satisfactory performance of ultrahigh-rate (UHR) filters in various applications, including in a Standard Oil Co. (Ohio) refinery; the development of UHR filtration plants by Hydrotechnic Corp.; the design and advantages of Hydrotechnic's filters; filtration; flow control and head loss; the backwash process; and the capital, construction, and operating costs of UHR filters (1000 to 7000 cu m/hr).

[Why? How? What for? We must measure the glomerular filtration].

PubMed

Treviño-Becerra, Alejandro

2010-01-01

The measurement of the glomerular filtration shows the degree of the functional qualities and the proficiency of the renal system. Despite new technologies, at present the best accepted technique for measuring the glomerular filtration in most countries is the clearance of creatinine in 24 hour urine. The clearance of creatinine has the advantage that it is confident, easy to reproduce, without technical limitations and low cost.

Assessing the role of spectral and intensity cues in spectral ripple detection and discrimination in cochlear-implant users.

PubMed

Anderson, Elizabeth S; Oxenham, Andrew J; Nelson, Peggy B; Nelson, David A

2012-12-01

Measures of spectral ripple resolution have become widely used psychophysical tools for assessing spectral resolution in cochlear-implant (CI) listeners. The objective of this study was to compare spectral ripple discrimination and detection in the same group of CI listeners. Ripple detection thresholds were measured over a range of ripple frequencies and were compared to spectral ripple discrimination thresholds previously obtained from the same CI listeners. The data showed that performance on the two measures was correlated, but that individual subjects' thresholds (at a constant spectral modulation depth) for the two tasks were not equivalent. In addition, spectral ripple detection was often found to be possible at higher rates than expected based on the available spectral cues, making it likely that temporal-envelope cues played a role at higher ripple rates. Finally, spectral ripple detection thresholds were compared to previously obtained speech-perception measures. Results confirmed earlier reports of a robust relationship between detection of widely spaced ripples and measures of speech recognition. In contrast, intensity difference limens for broadband noise did not correlate with spectral ripple detection measures, suggesting a dissociation between the ability to detect small changes in intensity across frequency and across time.

Assessing the role of spectral and intensity cues in spectral ripple detection and discrimination in cochlear-implant users

PubMed Central

Anderson, Elizabeth S.; Oxenham, Andrew J.; Nelson, Peggy B.; Nelson, David A.

2012-01-01

Measures of spectral ripple resolution have become widely used psychophysical tools for assessing spectral resolution in cochlear-implant (CI) listeners. The objective of this study was to compare spectral ripple discrimination and detection in the same group of CI listeners. Ripple detection thresholds were measured over a range of ripple frequencies and were compared to spectral ripple discrimination thresholds previously obtained from the same CI listeners. The data showed that performance on the two measures was correlated, but that individual subjects’ thresholds (at a constant spectral modulation depth) for the two tasks were not equivalent. In addition, spectral ripple detection was often found to be possible at higher rates than expected based on the available spectral cues, making it likely that temporal-envelope cues played a role at higher ripple rates. Finally, spectral ripple detection thresholds were compared to previously obtained speech-perception measures. Results confirmed earlier reports of a robust relationship between detection of widely spaced ripples and measures of speech recognition. In contrast, intensity difference limens for broadband noise did not correlate with spectral ripple detection measures, suggesting a dissociation between the ability to detect small changes in intensity across frequency and across time. PMID:23231122

ADVANCED ELECTROSTATIC ENHANCEMENT OF FABRIC FILTRATION

EPA Science Inventory

The paper discusses laboratory and pilot plant studies of a modification of the U.S. EPA's Electrically Stimulated Fabric Filtration (ESFF) method in which corona voltage on a center-wire electrode replaces the subcorona electrodes at the bag surface. The electric field which aff...

Microvascular pressures and filtration coefficients in the cat mesentery.

PubMed Central

Fraser, P A; Smaje, L H; Verrinder, A

1978-01-01

1. Filtration coefficient and hydrostatic pressure have been measured in single capillaries and venules in the cat mesentery using a modification of the Landis (1927) single vessel occlusion technique. 2. Venules were found to be filtering fluid, not absorbing it as is often supposed. 3. The mean filtration coefficient in capillaries was 0.018 micrometers . s-1 . mmHg-1 (1.35 X 10(-10)m . s-1 . Pa-1) while that in venules, was 0.027 micrometers . s-1 . mmHg-1 (2.02 X 10(-10)m . s-1 . Pa-1). 4. In both capillaries and venules, filtration coefficient increased with decreasing pressure. 5. The difference between directly measured venular pressure and that calculated from the occlusion data was used to determine the contribution of the interstitium to fluid exchange. In the mesentery superfused with Krebs solution the tissue pressure so determined was found to be zero or subatmospheric initially but became increasingly positive with lengthening exposure of the mesentery. PMID:722585

Structural ordering of casein micelles on silicon nitride micro-sieves during filtration.

PubMed

Gebhardt, Ronald; Holzmüller, Wolfgang; Zhong, Qi; Müller-Buschbaum, Peter; Kulozik, Ulrich

2011-11-01

The paper reports on the structure and formation of casein micelle deposits on silicon nitride micro-sieves during the frontal filtration. The most frequent radius of the fractionated casein micelles we use is R=60 nm as detected by static light scattering (SLS) and atomic force microscopy (AFM). We estimate the size and size distribution of the casein micelles which pass through the micro-sieve during the filtration process. A sharpening of the size distribution at the beginning of the filtration process (t=40s) is followed by a broadening and a shift of the most frequent radii towards smaller sizes at later times (t=840 s). The size distribution of the micelles deposited on the micro-sieve during filtration is bimodal and consists of the largest and smallest micelles. At larger filtration times, we observe a shift of both deposited size classes towards smaller sizes. The atomic force micrographs of the reference sample reveal a tendency of the casein micelles to order in a hexagonal lattice when deposited on the micro-sieves by solution casting. The deposition of two size classes can be explained by a formation of a mixed hexagonal lattice with large micelles building up the basis lattice and smaller sizes filling octahedral and tetrahedral holes of the lattice. The accompanied compression with increasing thickness of the casein layer could result from preferential deposition of smaller sizes in the course of the filtration. Copyright © 2011 Elsevier B.V. All rights reserved.

Estimation of single-kidney glomerular filtration rate without exogenous contrast agent.

PubMed

He, Xiang; Aghayev, Ayaz; Gumus, Serter; Ty Bae, K

2014-01-01

Measurement of single-kidney filtration fraction and glomerular filtration rate (GFR) without exogenous contrast is clinically important to assess renal function and pathophysiology, especially for patients with comprised renal function. The objective of this study is to develop a novel MR-based tool for noninvasive quantification of renal function using conventional MR arterial spin labeling water as endogenous tracer. The regional differentiation of the arterial spin labeling water between the glomerular capsular space and the renal parenchyma was characterized and measured according to their MR relaxation properties (T1ρ or T2 ), and applied to the estimation of filtration fraction and single-kidney GFR. The proposed approach was tested to quantify GFR in healthy volunteers at baseline and after a protein-loading challenge. Biexponential decay of the cortical arterial spin labeling water MR signal was observed. The major component decays the same as parenchyma water; the minor component decays much slower as expected from glomerular ultra-filtrates. The mean single-kidney GFR was estimated to be 49 ± 9 mL/min at baseline and increased by 28% after a protein-loading challenge. We developed an arterial spin labeling-based MR imaging method that allows us to estimate renal filtration fraction and singe-kidney GFR without use of exogenous contrast. Copyright © 2013 Wiley Periodicals, Inc.

Effect of filtration on rolling-element-bearing life in contaminated lubricant environment

NASA Technical Reports Server (NTRS)

Loewenthal, S. H.; Moyer, D. W.; Sherlock, J. J.

1978-01-01

Fatigue tests were conducted on groups of 65 millimeter-bore ball bearings under four levels of filtration with and without a contaminated MIL-L-23699 lubricant. The baseline series used noncontaminated oil with 49 micron absolute filtration. In the remaining tests contaminants of the composition found in aircraft engine filters were injected into the filter's supply line at a constant rate of 125 milligrams per bearing-hour. The test filters had absolute particle removal ratings of 3, 30, 49, and 105 microns (0.45, 10, 30, and 70 microns nominal), respectively. Bearings were tested at 15,000 rpm under 4580 newtons radial load. Bearing life and running tract condition generally improved with finer filtration. The 3 and 30 micron filter bearings in a contaminated lubricant had statistically equivalent lives, approaching those from the baseline tests. The experimental lives of 49 micron bearings were approximately half the baseline bearing's lives. Bearings tested with the 105 micron filter experienced wear failures. The degree of surface distress, weight loss, and probable failure mode were found to be dependent on filtration level, with finer filtration being clearly beneficial.

Filtration effects on ball bearing life and condition in a contaminated lubricant

NASA Technical Reports Server (NTRS)

Loewenthal, S. H.; Moyer, D. W.

1978-01-01

Ball bearings were fatigue tested with a noncontaminated MIL-L-23699 lubricant and with a contaminated MIL-L-23699 lubricant under four levels of filtration. The test filters had absolute particle removal ratings of 3, 30, 49, and 105 microns. Aircraft turbine engine contaminants were injected into the filter's supply line at a constant rate of 125 milligrams per bearing hour. Bearing life and running track condition generally improved with finer filtration. The experimental lives of 3- and 30-micron filter bearings were statistically equivalent, approaching those obtained with the noncontaminated lubricant bearings. Compared to these bearings, the lives of the 49-micron bearings were statistically lower. The 105-micron bearings experienced gross wear. The degree of surface distress, weight loss, and probable failure mode were dependent on filtration level, with finer filtration being clearly beneficial.

Development of a dialyzer with enhanced internal filtration to increase the clearance of low molecular weight proteins.

PubMed

Fujimura, Takayasu; Uchi, Yukihiko; Fukuda, Makoto; Miyazaki, Miwa; Uezumi, Satoshi; Hiyoshi, Tatsuo

2004-01-01

Accumulated low molecular weight proteins in hemodialysis patients require a high-flux dialyzer. There have been several methods proposed for enhancing internal filtration, including narrowing the inside diameter of the hollow fibers, lengthening the fibers, and increasing the fiber density ratio. We tried to enhance the internal filtration by increasing the pressure drop in the dialysate compartment through increasing the fiber density ratio. If the fiber density ratio is too high, however, an irregular dialysate path may result, thus decreasing dialysis performance. Therefore, we took note of the shape of the inner housing and added a short taper structure, which improved the dialysate path dramatically. Consequently, we developed an internal filtration-enhanced dialyzer (APS-Prototype) to improve dialysis performance. The internal filtration rate in water (measured by Doppler ultrasound) was 13.2 l/session for the APS-Prototype and 5.3 l/session for the APS-15E. The amount of alpha1-microglobulin (alpha1-MG) in bovine plasma was 0.34 g for the APS-Prototype and 0.11 g for the APS-15E. In addition, the amount of alpha1-MG in vivo was 29.0% +/- 5.8% for the APS-Prototype, significantly higher than that for the APS-15E (13.6% +/- 1.9%). The desirable loss of albumin is 2-4 g in hemodiafiltration, and it was 3.92 +/- 1.03 g for the APS-Prototype. The prototype showed excellent solute removal performance with no clinical or engineering problems.

Assessing FRET using Spectral Techniques

PubMed Central

Leavesley, Silas J.; Britain, Andrea L.; Cichon, Lauren K.; Nikolaev, Viacheslav O.; Rich, Thomas C.

2015-01-01

Förster resonance energy transfer (FRET) techniques have proven invaluable for probing the complex nature of protein–protein interactions, protein folding, and intracellular signaling events. These techniques have traditionally been implemented with the use of one or more fluorescence band-pass filters, either as fluorescence microscopy filter cubes, or as dichroic mirrors and band-pass filters in flow cytometry. In addition, new approaches for measuring FRET, such as fluorescence lifetime and acceptor photobleaching, have been developed. Hyperspectral techniques for imaging and flow cytometry have also shown to be promising for performing FRET measurements. In this study, we have compared traditional (filter-based) FRET approaches to three spectral-based approaches: the ratio of acceptor-to-donor peak emission, linear spectral unmixing, and linear spectral unmixing with a correction for direct acceptor excitation. All methods are estimates of FRET efficiency, except for one-filter set and three-filter set FRET indices, which are included for consistency with prior literature. In the first part of this study, spectrofluorimetric data were collected from a CFP–Epac–YFP FRET probe that has been used for intracellular cAMP measurements. All comparisons were performed using the same spectrofluorimetric datasets as input data, to provide a relevant comparison. Linear spectral unmixing resulted in measurements with the lowest coefficient of variation (0.10) as well as accurate fits using the Hill equation. FRET efficiency methods produced coefficients of variation of less than 0.20, while FRET indices produced coefficients of variation greater than 8.00. These results demonstrate that spectral FRET measurements provide improved response over standard, filter-based measurements. Using spectral approaches, single-cell measurements were conducted through hyperspectral confocal microscopy, linear unmixing, and cell segmentation with quantitative image analysis

Assessing FRET using spectral techniques.

PubMed

Leavesley, Silas J; Britain, Andrea L; Cichon, Lauren K; Nikolaev, Viacheslav O; Rich, Thomas C

2013-10-01

Förster resonance energy transfer (FRET) techniques have proven invaluable for probing the complex nature of protein-protein interactions, protein folding, and intracellular signaling events. These techniques have traditionally been implemented with the use of one or more fluorescence band-pass filters, either as fluorescence microscopy filter cubes, or as dichroic mirrors and band-pass filters in flow cytometry. In addition, new approaches for measuring FRET, such as fluorescence lifetime and acceptor photobleaching, have been developed. Hyperspectral techniques for imaging and flow cytometry have also shown to be promising for performing FRET measurements. In this study, we have compared traditional (filter-based) FRET approaches to three spectral-based approaches: the ratio of acceptor-to-donor peak emission, linear spectral unmixing, and linear spectral unmixing with a correction for direct acceptor excitation. All methods are estimates of FRET efficiency, except for one-filter set and three-filter set FRET indices, which are included for consistency with prior literature. In the first part of this study, spectrofluorimetric data were collected from a CFP-Epac-YFP FRET probe that has been used for intracellular cAMP measurements. All comparisons were performed using the same spectrofluorimetric datasets as input data, to provide a relevant comparison. Linear spectral unmixing resulted in measurements with the lowest coefficient of variation (0.10) as well as accurate fits using the Hill equation. FRET efficiency methods produced coefficients of variation of less than 0.20, while FRET indices produced coefficients of variation greater than 8.00. These results demonstrate that spectral FRET measurements provide improved response over standard, filter-based measurements. Using spectral approaches, single-cell measurements were conducted through hyperspectral confocal microscopy, linear unmixing, and cell segmentation with quantitative image analysis. Results from

Vulnerability of bank filtration systems to climate change.

PubMed

Sprenger, C; Lorenzen, G; Hülshoff, I; Grützmacher, G; Ronghang, M; Pekdeger, A

2011-01-15

Bank filtration (BF) is a well established and proven natural water treatment technology, where surface water is infiltrated to an aquifer through river or lake banks. Improvement of water quality is achieved by a series of chemical, biological and physical processes during subsurface passage. This paper aims at identifying climate sensitive factors affecting bank filtration performance and assesses their relevance based on hypothetical 'drought' and 'flood' climate scenarios. The climate sensitive factors influencing water quantity and quality also have influence on substance removal parameters such as redox conditions and travel time. Droughts are found to promote anaerobic conditions during bank filtration passage, while flood events can drastically shorten travel time and cause breakthrough of pathogens, metals, suspended solids, DOC and organic micropollutants. The study revealed that only BF systems comprising an oxic to anoxic redox sequence ensure maximum removal efficiency. The storage capacity of the banks and availability of two source waters renders BF for drinking water supply less vulnerable than surface water or groundwater abstraction alone. Overall, BF is vulnerable to climate change although anthropogenic impacts are at least as important. Copyright © 2010 Elsevier B.V. All rights reserved.

Diatomite releases silica during spirit filtration.

PubMed

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.

Isolation of circulating tumor cells from pancreatic cancer by automated filtration

PubMed Central

Brychta, Nora; Drosch, Michael; Driemel, Christiane; Fischer, Johannes C.; Neves, Rui P.; Esposito, Irene; Knoefel, Wolfram; Möhlendick, Birte; Hille, Claudia; Stresemann, Antje; Krahn, Thomas; Kassack, Matthias U.; Stoecklein, Nikolas H.; von Ahsen, Oliver

2017-01-01

It is now widely recognized that the isolation of circulating tumor cells based on cell surface markers might be hindered by variability in their protein expression. Especially in pancreatic cancer, isolation based only on EpCAM expression has produced very diverse results. Methods that are independent of surface markers and therefore independent of phenotypical changes in the circulating cells might increase CTC recovery also in pancreatic cancer. We compared an EpCAM-dependent (IsoFlux) and a size-dependent (automated Siemens Healthineers filtration device) isolation method for the enrichment of pancreatic cancer CTCs. The recovery rate of the filtration based approach is dramatically superior to the EpCAM-dependent approach especially for cells with low EpCAM-expression (filtration: 52%, EpCAM-dependent: 1%). As storage and shipment of clinical samples is important for centralized analyses, we also evaluated the use of frozen diagnostic leukapheresis (DLA) as source for isolating CTCs and subsequent genetic analysis such as KRAS mutation detection analysis. Using frozen DLA samples of pancreatic cancer patients we detected CTCs in 42% of the samples by automated filtration. PMID:29156783

Isolation of circulating tumor cells from pancreatic cancer by automated filtration.

PubMed

Brychta, Nora; Drosch, Michael; Driemel, Christiane; Fischer, Johannes C; Neves, Rui P; Esposito, Irene; Knoefel, Wolfram; Möhlendick, Birte; Hille, Claudia; Stresemann, Antje; Krahn, Thomas; Kassack, Matthias U; Stoecklein, Nikolas H; von Ahsen, Oliver

2017-10-17

It is now widely recognized that the isolation of circulating tumor cells based on cell surface markers might be hindered by variability in their protein expression. Especially in pancreatic cancer, isolation based only on EpCAM expression has produced very diverse results. Methods that are independent of surface markers and therefore independent of phenotypical changes in the circulating cells might increase CTC recovery also in pancreatic cancer. We compared an EpCAM-dependent (IsoFlux) and a size-dependent (automated Siemens Healthineers filtration device) isolation method for the enrichment of pancreatic cancer CTCs. The recovery rate of the filtration based approach is dramatically superior to the EpCAM-dependent approach especially for cells with low EpCAM-expression (filtration: 52%, EpCAM-dependent: 1%). As storage and shipment of clinical samples is important for centralized analyses, we also evaluated the use of frozen diagnostic leukapheresis (DLA) as source for isolating CTCs and subsequent genetic analysis such as KRAS mutation detection analysis. Using frozen DLA samples of pancreatic cancer patients we detected CTCs in 42% of the samples by automated filtration.

Spectral distortions of the cosmic microwave background

NASA Technical Reports Server (NTRS)

Adams, Fred C.; Mcdowell, Jonathan C.; Freese, Katherine; Levin, Janna

1989-01-01

Recent experiments indicate that the spectrum of the cosmic microwave background deviates from a pure blackbody; here, spectral distortions produced by cosmic dust are considered. The main result is that cosmic dust in conjunction with an injected radiation field (perhaps produced by an early generation of very massive stars) can explain the observed spectral distortions without violating existing cosmological constraints. In addition, it is shown that Compton y-distortions can also explain the observed spectral shape, but the energetic requirements are more severe.

Recirculating Air Filtration Significantly Reduces Exposure to Airborne Nanoparticles

PubMed Central

Pui, David Y.H.; Qi, Chaolong; Stanley, Nick; Oberdörster, Günter; Maynard, Andrew

2008-01-01

Background Airborne nanoparticles from vehicle emissions have been associated with adverse effects in people with pulmonary and cardiovascular disease, and toxicologic studies have shown that nanoparticles can be more hazardous than their larger-scale counterparts. Recirculating air filtration in automobiles and houses may provide a low-cost solution to reducing exposures in many cases, thus reducing possible health risks. Objectives We investigated the effectiveness of recirculating air filtration on reducing exposure to incidental and intentionally produced airborne nanoparticles under two scenarios while driving in traffic, and while generating nanomaterials using gas-phase synthesis. Methods We tested the recirculating air filtration in two commercial vehicles when driving in traffic, as well as in a nonventilation room with a nanoparticle generator, simulating a nanomaterial production facility. We also measured the time-resolved aerosol size distribution during the in-car recirculation to investigate how recirculating air filtration affects particles of different sizes. We developed a recirculation model to describe the aerosol concentration change during recirculation. Results The use of inexpensive, low-efficiency filters in recirculation systems is shown to reduce nanoparticle concentrations to below levels found in a typical office within 3 min while driving through heavy traffic, and within 20 min in a simulated nanomaterial production facility. Conclusions Development and application of this technology could lead to significant reductions in airborne nanoparticle exposure, reducing possible risks to health and providing solutions for generating nanomaterials safely. PMID:18629306

The Effects of Antifoam Agent on Dead End Filtration Process

NASA Astrophysics Data System (ADS)

Mohamad Pauzi, S.; Ahmad, N.; Yahya, M. F.; Arifin, M. A.

2018-05-01

The formation of foam as a result from introducing gases during cell culture process in the bioprocess industry has indirectly affected the throughput of the product of interest. Due to that, antifoams were developed and established as one of the means to minimize the formation of foam in the cell culture. There are many types of antifoams but the silicone-type of antifoams are widely used in the bioprocess industry. Although the establishment of antifoam has aided the cell culture process, the impacts of its presence in the cell culture to the downstream process especially the dead end filtration is not widely discussed. The findings in the study emphasized on the dead end filtration performance that includes flux rate profile and the resulted filtration capacity. In this study, the concentrations of antifoam injected into the solution were varied from 0.2% v/v – 1.0% v/v and the solutions were filtered using constant flow method. The resulted maximum pressure readings and final flux rates indicated that the resistance exerted to the feed flow rate increased as the concentration of antifoam loaded in the solution increased. This later has led to the decline in the flux rates with percentage reduction between 32 – 68%. The calculated filter capacity for flux rate of 1000LMH ranged from 53 – 63L/m2 while it is in the range of 40 – 43L/m2 for flux rate of 2000LMH. The presence of antifoam agents in the feed load was determined to have negative effects on the dead end filtration performance and it may reduce the efficiency of the dead end filtration process.

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

PubMed

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.

DIFFERENTIATION BETWEEN CERTAIN TOXIC PROPERTIES OF FILTRATES OF HEMOLYTIC STAPHYLOCOCCUS AUREUS

PubMed Central

Weld, Julia T. Parker; Gunther, Anne

1931-01-01

1. Sterile filtrates from certain hemotoxic strains of Staphylococcus aureus have several toxic properties, of which the most important are the hemotoxic, the necrotoxic, the leucocidic and the property of killing rapidly. 2. The necrotoxic action appears to be caused by a constituent in the filtrates different from either the hemotoxic or the leucocidic one. PMID:19869919

In-home air filtration for improving cardiovascular health: Lessons from a CBPR study in public housing

PubMed Central

Brugge, Doug; Reisner, Ellin; Padró-Martínez, Luz T.; Zamore, Wig; Owusu, Emmanuel; Durant, John L.

2013-01-01

Background Particulate air pollution, including from motor vehicles, is associated with cardiovascular disease. Objectives To describe lessons learned from installing air filtration units in public housing apartments next to a major highway. Methods We reviewed experience with recruitment, retention and acceptance of the air filtration units. Results Recruitment and retention have been challenging, but similar to other studies in public housing. Equipment noise and overheated apartments during hot weather have been notable complaints from participants. In addition, we found that families with members with Alzheimer’s or mental disability were less able to tolerate the equipment. Conclusions For this research the primary lesson is that working closely with each participant is important. A future public health program would need to address issues of noise and heat to make the intervention more acceptable to residents. PMID:23543021

Breakthrough of cyanobacteria in bank filtration.

PubMed

Pazouki, Pirooz; Prévost, Michèle; McQuaid, Natasha; Barbeau, Benoit; de Boutray, Marie-Laure; Zamyadi, Arash; Dorner, Sarah

2016-10-01

The removal of cyanobacteria cells in well water following bank filtration was investigated from a source water consisting of two artificial lakes (A and B). Phycocyanin probes used to monitor cyanobacteria in the source and in filtered well water showed an increase of fluorescence values demonstrating a progressive seasonal growth of cyanobacteria in the source water that were correlated with cyanobacterial biovolumes from taxonomic counts (r = 0.59, p < 0.00001). A strong correlation was observed between the cyanobacterial concentrations in the lake water and in the well water as measured by the phycocyanin probe (p < 0.001, 0.73 ≤ r(2) ≤ 0.94). Log removals from bank filtration estimated from taxonomic counts ranged from 0.96 ± (0.5) and varied according to the species of cyanobacteria. Of cyanobacteria that passed through bank filtration, smaller cells were significantly more frequent in well water samples (p < 0.05) than larger cells. Travel times from the lakes to the wells were estimated as 2 days for Lake B and 10 days for Lake A. Cyanobacterial species in the wells were most closely related to species found in Lake B. Thus, a travel time of less than 1 week permitted the breakthrough of cyanobacteria to wells. Winter samples demonstrated that cyanobacteria accumulate within bank filters, leading to continued passage of cells beyond the bloom season. Although no concentrations of total microcystin-LR were above detection limits in filtered well water, there is concern that cyanobacterial cells that reach the wells have the potential to contain intracellular toxins. Copyright © 2016 Elsevier Ltd. All rights reserved.

Highly Efficient Large-Scale Lentiviral Vector Concentration by Tandem Tangential Flow Filtration

PubMed Central

Cooper, Aaron R.; Patel, Sanjeet; Senadheera, Shantha; Plath, Kathrin; Kohn, Donald B.; Hollis, Roger P.

2014-01-01

Large-scale lentiviral vector (LV) concentration can be inefficient and time consuming, often involving multiple rounds of filtration and centrifugation. This report describes a simpler method using two tangential flow filtration (TFF) steps to concentrate liter-scale volumes of LV supernatant, achieving in excess of 2000-fold concentration in less than 3 hours with very high recovery (>97%). Large volumes of LV supernatant can be produced easily through the use of multi-layer flasks, each having 1720 cm2 surface area and producing ~560 mL of supernatant per flask. Combining the use of such flasks and TFF greatly simplifies large-scale production of LV. As a demonstration, the method is used to produce a very high titer LV (>1010 TU/mL) and transduce primary human CD34+ hematopoietic stem/progenitor cells at high final vector concentrations with no overt toxicity. A complex LV (STEMCCA) for induced pluripotent stem cell generation is also concentrated from low initial titer and used to transduce and reprogram primary human fibroblasts with no overt toxicity. Additionally, a generalized and simple multiplexed real- time PCR assay is described for lentiviral vector titer and copy number determination. PMID:21784103

Adaptation to spectrally-rotated speech.

PubMed

Green, Tim; Rosen, Stuart; Faulkner, Andrew; Paterson, Ruth

2013-08-01

Much recent interest surrounds listeners' abilities to adapt to various transformations that distort speech. An extreme example is spectral rotation, in which the spectrum of low-pass filtered speech is inverted around a center frequency (2 kHz here). Spectral shape and its dynamics are completely altered, rendering speech virtually unintelligible initially. However, intonation, rhythm, and contrasts in periodicity and aperiodicity are largely unaffected. Four normal hearing adults underwent 6 h of training with spectrally-rotated speech using Continuous Discourse Tracking. They and an untrained control group completed pre- and post-training speech perception tests, for which talkers differed from the training talker. Significantly improved recognition of spectrally-rotated sentences was observed for trained, but not untrained, participants. However, there were no significant improvements in the identification of medial vowels in /bVd/ syllables or intervocalic consonants. Additional tests were performed with speech materials manipulated so as to isolate the contribution of various speech features. These showed that preserving intonational contrasts did not contribute to the comprehension of spectrally-rotated speech after training, and suggested that improvements involved adaptation to altered spectral shape and dynamics, rather than just learning to focus on speech features relatively unaffected by the transformation.

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

NASA Astrophysics Data System (ADS)

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.

Effects of filtration modes on membrane fouling behavior and treatment in submerged membrane bioreactor.

PubMed

Maqbool, Tahir; Khan, Sher Jamal; Lee, Chung-Hak

2014-11-01

Relaxation or backwashing is obligatory for effective operation of membrane module and intermittent aeration is helpful for nutrients removal. This study was performed to investigate effects of different filtration modes on membrane fouling behavior and treatment in membrane bioreactor (MBR) operated at three modes i.e., 12, 10 and 8min filtration and 3, 2, and 2min relaxation corresponding to 6, 5 and 4cycles/hour, respectively. Various parameters including trans-membrane pressure, specific cake resistance, specific oxygen uptake rate, nutrients removal and sludge dewaterability were examined to optimize the filtration mode. TMP profiles showed that MBR(8+2) with 8min filtration and 2min relaxation reduced the fouling rate and depicted long filtration time in MBR treating synthetic wastewater. MBR(12+3) was more efficient in organic and nutrients removal while denitrification rate was high in MBR(8+2). Copyright © 2014 Elsevier Ltd. All rights reserved.

Estimation of spectral kurtosis

NASA Astrophysics Data System (ADS)

Sutawanir

2017-03-01

Rolling bearings are the most important elements in rotating machinery. Bearing frequently fall out of service for various reasons: heavy loads, unsuitable lubrications, ineffective sealing. Bearing faults may cause a decrease in performance. Analysis of bearing vibration signals has attracted attention in the field of monitoring and fault diagnosis. Bearing vibration signals give rich information for early detection of bearing failures. Spectral kurtosis, SK, is a parameter in frequency domain indicating how the impulsiveness of a signal varies with frequency. Faults in rolling bearings give rise to a series of short impulse responses as the rolling elements strike faults, SK potentially useful for determining frequency bands dominated by bearing fault signals. SK can provide a measure of the distance of the analyzed bearings from a healthy one. SK provides additional information given by the power spectral density (psd). This paper aims to explore the estimation of spectral kurtosis using short time Fourier transform known as spectrogram. The estimation of SK is similar to the estimation of psd. The estimation falls in model-free estimation and plug-in estimator. Some numerical studies using simulations are discussed to support the methodology. Spectral kurtosis of some stationary signals are analytically obtained and used in simulation study. Kurtosis of time domain has been a popular tool for detecting non-normality. Spectral kurtosis is an extension of kurtosis in frequency domain. The relationship between time domain and frequency domain analysis is establish through power spectrum-autocovariance Fourier transform. Fourier transform is the main tool for estimation in frequency domain. The power spectral density is estimated through periodogram. In this paper, the short time Fourier transform of the spectral kurtosis is reviewed, a bearing fault (inner ring and outer ring) is simulated. The bearing response, power spectrum, and spectral kurtosis are plotted to

Albuminuria and Glomerular Filtration Rate in Individuals with Type 1 Diabetes Mellitus: Contribution of Metabolic Syndrome.

PubMed

Uribe-Wiechers, Ana Cecilia; Janka-Zires, Marcela; Almeda-Valdés, Paloma; López-Gutiérrez, Joel; Gómez-Pérez, Francisco J

2015-01-01

The development of metabolic syndrome has been described in patients with type 1 diabetes mellitus as the disease progresses over time. The purpose of this study is to assess the relationship between metabolic syndrome, albuminuria, and glomerular filtration rate, as well as to determine the prevalence of metabolic syndrome, in a group of Mexican patients with type 1 diabetes mellitus. We conducted a cross-sectional study that included patients with type 1 diabetes mellitus who were diagnosed over 10 years ago and who are seen at the Diabetes Intensive Control Clinic of the Instituto Nacional de Ciencias Medicas y Nutricion Salvador Zubiran in Mexico City. The presence of metabolic syndrome was determined by using the National Cholesterol Education Program-Adult Treatment Panel III (ATP III) criteria. A total of 81 individuals were studied. The prevalence of metabolic syndrome was 18.5% (n = 15). A higher albuminuria was found in subjects with metabolic syndrome (34.9 mg/24 hours; 8.3-169.3) than in those without metabolic syndrome (9.0 mg/24 hours; 5.0-27.0; p = 0.02). Glomerular filtration rate was lower in patients with metabolic syndrome (95.3 ml/minute; [64.9-107.2] vs. 110.2 ml/minute [88.1-120.3]; p = 0.04). After classifying the population according to the number of metabolic syndrome criteria, a progressive increase in albuminuria and a progressive decrease in glomerular filtration rate were found with each additional metabolic syndrome criterion (p = 0.008 and p = 0.032, respectively). After adjusting for age, time from diagnosis, systolic blood pressure, triglycerides, HDL-cholesterol, and treatment with angiotensin receptor blockers or angiotensin converting enzyme inhibitors, we found that age, time from diagnosis, triglycerides, and HDL-cholesterol were independent factors associated with glomerular filtration rate (R2 = 0.286; p < 0.001). Metabolic syndrome was associated with a higher albuminuria and a reduction in glomerular filtration rate in

Sperm preparation through Sephadex™ filtration improves in vitro fertilization rate of buffalo oocytes.

PubMed

Husna, A U; Azam, A; Qadeer, S; Awan, M A; Nasreen, S; Shahzad, Q; Fouladi-Nashta, A; Khalid, M; Akhter, S

2018-04-01

Routinely, swim-up method is used to separate high-quality sperm; however, long processing time and close cell-to-cell contact during the centrifugation step are inevitable elements of oxidative stress to sperm. The objective was to evaluate Sephadex ™ and glass wool filtration to separate motile, intact and viable sperm for in vitro fertilization in buffalo. The cumulus-oocyte complexes (COCs) were collected from ovaries of slaughtered buffaloes by aspiration and matured for 24 hr in CO 2 incubator at 38.5°C and 5% CO 2 . Matured COCs were rinsed twice in fertilization TALP and placed in the pre-warmed fertilization medium without sperm. Cryopreserved buffalo semen was thawed at 37°C for 30 s and processed through Sephadex ™ , glass wool filtration and swim-up (control). Total and motile sperm recovery rates were assessed, resuspended in fertilization TALP and incubated for 15-20 min in CO 2 incubator. Samples prepared by each method were divided into two aliquots: one aliquot was studied for sperm quality (progressive motility, membrane integrity, viability, liveability), while the other was subjected to co-incubation with sets of 10-15 in vitro matured oocytes. Data on sperm quality were analysed by ANOVA, while in vitro fertilizing rates were compared by chi-squared test using SPSS-20. Least significant difference (LSD) test was used to compare treatment means. Glass wool filtration yielded higher total and motile sperm recovery rate, while Sephadex ™ filtration improved (p < .05) sperm quality (progressive motility, membrane integrity, viability, liveability). Sperm preparation through Sephadex filtration yielded higher in vitro fertilization rate in terms of cleavage rate compared to glass wool filtration and swim-up (control). In conclusion, cryopreserved Nili-Ravi buffalo sperm selected through Sephadex filtration showed improved quality and yielded better fertilization rates (cleavage rate) of in vitro matured/fertilized oocytes. Sephadex

Experimental study of the effect of polyanionic cellulose on process of filtrate loss of low-solids drilling fluid

NASA Astrophysics Data System (ADS)

yang, P.

2013-12-01

Experimental study of the effect of polyanionic cellulose on process of filtrate loss of low-solids drilling fluid Ping Yang 1,2, Min-hui Wu2, Xue-wen Zhu2, Tao Deng2, Xue-qing Sun2 1. Key Laboratory of Geotechnical and Underground Engineering of Ministry of Education, Tongji University, Shanghai 200092,China 2. Department of Geotechnical Engineering,Tongji University,Shanghai 200092,China Abstract The process of filtrate loss of low-solids drilling fluid was tested by changing the polyanionic cellulose content in low-solids drilling fluid. The effect of polyanionic cellulose on process of filtrate loss of low-solids drilling fluid was analyzed. The test results showed that when time of filtration is same, the volume of filtrate loss decreases linearly with increasing polyanionic cellulose content. When polyanionic cellulose content is same, the rate of filtrate loss decreases nonlinearly with increasing time and the rate of filtrate loss will reach a stable value.The volume of filtrate loss in 7 to 8 minutes can reaches half of the total volume of filtrate loss. At the same time, the rate of filtrate loss of drilling fluid decreases nonlinearly with increasing viscosity.When the apparent viscosity is between 3.5~4.15 MPa.s, decrease speed of rate of filtrate loss of drilling fluid is quick. The results are helpful for characteristics evaluation of filtrate loss of drilling fluid and control of filtrate loss. Keyword Polyanionic Cellulose,Drilling Fluid,Process of Filtrate Loss Acknowledgments This investigation was supported by the National Natural Science Foundation of China (projects No. 41002093 and 41072205); the Fundamental Research Funds for the Central Universities; the Shanghai Leading Academic Discipline Project (project No. B308), Tongji University; and the Program for Young Excellent Talents, Tongji University. The authors are extremely grateful for the financial support from these five organizations.

Conjugation of fiber-coupled wide-band light sources and acousto-optical spectral elements

NASA Astrophysics Data System (ADS)

Machikhin, Alexander; Batshev, Vladislav; Polschikova, Olga; Khokhlov, Demid; Pozhar, Vitold; Gorevoy, Alexey

2017-12-01

Endoscopic instrumentation is widely used for diagnostics and surgery. The imaging systems, which provide the hyperspectral information of the tissues accessible by endoscopes, are particularly interesting and promising for in vivo photoluminescence diagnostics and therapy of tumour and inflammatory diseases. To add the spectral imaging feature to standard video endoscopes, we propose to implement acousto-optical (AO) filtration of wide-band illumination of incandescent-lamp-based light sources. To collect maximum light and direct it to the fiber-optic light guide inside the endoscopic probe, we have developed and tested the optical system for coupling the light source, the acousto-optical tunable filter (AOTF) and the light guide. The system is compact and compatible with the standard endoscopic components.

Spectral Unmixing With Multiple Dictionaries

NASA Astrophysics Data System (ADS)

Cohen, Jeremy E.; Gillis, Nicolas

2018-02-01

Spectral unmixing aims at recovering the spectral signatures of materials, called endmembers, mixed in a hyperspectral or multispectral image, along with their abundances. A typical assumption is that the image contains one pure pixel per endmember, in which case spectral unmixing reduces to identifying these pixels. Many fully automated methods have been proposed in recent years, but little work has been done to allow users to select areas where pure pixels are present manually or using a segmentation algorithm. Additionally, in a non-blind approach, several spectral libraries may be available rather than a single one, with a fixed number (or an upper or lower bound) of endmembers to chose from each. In this paper, we propose a multiple-dictionary constrained low-rank matrix approximation model that address these two problems. We propose an algorithm to compute this model, dubbed M2PALS, and its performance is discussed on both synthetic and real hyperspectral images.

The substitution of sand filtration by immersed-UF for surface water treatment: pilot-scale studies.

PubMed

Lihua, Sun; Xing, Li; Guoyu, Zhang; Jie, Chen; Zhe, Xu; Guibai, Li

2009-01-01

The newly issued National Drinking Water Standard required that turbidity should be lower than 1 NTU, and the substitution of sand filtration by immersed ultrafiltration (immersed-UF) is feasible to achieve the standard. This study aimed to optimise the operational processes (i.e. aeration, backwashing) through pilot scale studies, to control membrane fouling while treating the sedimentation effluent. Results indicated that the immersed-UF was promising to treat the sedimentation effluent. The turbidity was below 0.10 NTU, bacteria and E. coli were not detected in the permeate water. The intermittent filtration with aeration is beneficial to inhibit membrane fouling. The critical aeration intensity is observed to be 60.0 m(3) m(-2) h(-1). At this aeration intensity, the decline rate of permeate flux in one period of backwashing was 1.94% and 7.03% for intermittent filtration and sustained filtration respectively. The different membrane backwashing methods (i.e. aeration 1.5 min, synchronous aeration and water backwashing 2 min, water backwashing 1.5 min; synchronous aeration and water backwashing 3 min, water backwashing 2 min; aeration 3 min, single water backwashing 2 min; synchronous aeration and water backwashing 5 min; single water backwashing 5 min) on the recovery of permeate flux were compared, indicating that the synchronous aeration and water backwashing exhibited best potential for permeate flux recovery. The optimal intensity of water backwashing is shown to be 90.0 L m(-2) h(-1). When the actual water intensity was below or exceeded the value, the recovery rate of permeate flux would be reduced. Additionally, the average operating cost for the immersed UF membrane, including the power, the chemical cleaning reagents, and membrane modules replacement, was about 0.31 RMB/m(3).

Influence of temperature, filter wettability, and timing of filtration on the removal of WBCs from RBC concentrates.

PubMed

van der Meer, P F; Pietersz, R N; Reesink, H W

2001-04-01

The efficacy of the removal of WBCs from buffy coat-reduced RBC concentrates by filtration is determined by many variables. The aim of this study was to investigate the influence of the filtration temperature, the wettability of the filter material, and the timing of the filtration after collection. The investigation used commercially available filters: 3 dry "online" filters (Cellselect FR, Fresenius Hemocare; BioR-01-max, Fresenius; Leucoflex LCG1, MacoPharma) and one wet "inline" filter (Leucoflex LCR4, MacoPharma) that contained saline-adenine-glucose-mannitol additive solution for RBCs and differed from the online version only in wettability. After buffy coat removal and suspension in saline-adenine-glucose-mannitol, filtrations were performed immediately at room temperature (RT) and after 2 hours' storage of the RBC concentrates at 4 degrees C, while the Leucoflex LCR4 was also tested after 24 hours' storage of the RBC concentrates at 4 degrees C. Sets of 12 pooled experiments were performed to prevent donor-dependent differences. The Cellselect FR gave significantly better WBC removal from RBC concentrates at 4 degrees C than at RT, with residual WBCs of 1.44 +/- 0.58 x 10(6) and 2.78 +/- 1.23 x 10(6), respectively (p<0.001). The BioR-01-max gave no significant difference: 0.62 +/- 0.27 x 10(6) WBCs (at 4 degrees C) versus 0.61 +/- 0.25 x 10(6) WBCs (at RT). Filtration with the Leucoflex LCG1 resulted in 0.06 +/- 0.03 x 10(6) and 0.07 +/- 0.07 x 10(6) WBCs at 4 degrees C and RT, respectively, which is not a significant difference. The Leucoflex LCR4, however, gave 2.08 +/- 0.84 x 10(6) WBCs at RT, 0.52 +/- 0.44 x 10(6) WBCs at 4 degrees C after 2 hours' cooling, and 0.05 +/- 0.10 x 10(6) WBCs at 4 degrees C after 24 hours' cooling (all p<0.001). Temperature, filter wettability, and timing of filtration after collection influence the efficacy of a filter for RBC concentrates. These variables need to be established, validated, and controlled before a filter

Nanoparticle Filtration in a RTM Processed Epoxy/Carbon Fiber Composite

NASA Technical Reports Server (NTRS)

Miller, Sandi G.; Micham, Logan; Copa, Christine C.; Criss, James M., Jr.; Mintz, Eric A.

2011-01-01

Several epoxy matrix composite panels were fabricated by resin transfer molding (RTM) E862/W resin onto a triaxially braided carbon fiber pre-form. Nanoparticles including carbon nanofiber, synthetic clay, and functionalized graphite were dispersed in the E862 matrix, and the extent of particle filtration during processing was characterized. Nanoparticle dispersion in the resin flashing on both the inlet and outlet edges of the panel was compared by TEM. Variation in physical properties such as Tg and moisture absorption throughout the panel were also characterized. All nanoparticle filled panels showed a decrease in Tg along the resin flow path across the panel, indicating nanoparticle filtration, however there was little change in moisture absorption. This works illustrates the need to obtain good nano-particle dispersion in the matrix resin to prevent particle agglomeration and hence particle filtration in the resultant polymer matrix composites (PMC).

The effect of membrane filtration on dissolved trace element concentrations

USGS Publications Warehouse

Horowitz, A.J.; Lum, K.R.; Garbarino, J.R.; Hall, G.E.M.; Lemieux, C.; Demas, C.R.

1996-01-01

The almost universally accepted operational definition for dissolved constituents is based on processing whole-water samples through a 0.45-??m membrane filter. Results from field and laboratory experiments indicate that a number of factors associated with filtration, other than just pore size (e.g., diameter, manufacturer, volume of sample processed, amount of suspended sediment in the sample), can produce substantial variations in the 'dissolved' concentrations of such elements as Fe, Al, Cu, Zn, Pb, Co, and Ni. These variations result from the inclusion/exclusion of colloidally- associated trace elements. Thus, 'dissolved' concentrations quantitated by analyzing filtrates generated by processing whole-water through similar pore- sized membrane filters may not be equal/comparable. As such, simple filtration through a 0.45-??m membrane filter may no longer represent an acceptable operational definition for dissolved chemical constituents. This conclusion may have important implications for environmental studies and regulatory agencies.

Microburger Biochemistry: Extraction and Spectral Characterization of Myoglyobin from Hamburger

NASA Astrophysics Data System (ADS)

Bylkas, Sheri A.; Andersson, Laura A.

1997-04-01

This experiment provides a demonstration of useful biochemical methods at a Basic or Advanced Level, depending upon the available spectrophotometric equipment. The protocol combines protein extraction, ox-i-dation and reduction, and simple spectroscopic analysis, as well as gel filtration chromatography and generation/analysis of spectral scans. Mammalian myoglobin (Mb) is a monomeric O2-binding protein that functions in muscle to store oxygen. The single iron protoporphyrin IX (heme) group is bound to protein by the amino acid Histidine93. The common, stable forms, Met-Mb and Oxy-Mb are studied because in a non-living system, red Oxy-Mb is converted to brown Met-Mb as bound O2 molecule is released. Mb is easily extracted from steak, to illustrate and address why fresh meat is red and aged meat is brown; the protein has unique spectral properties that are diagnostic for characterization of sample identity. After application of heme redox chemical methods, the MetMb or OxyMb samples can be studied spectroscopically. The color change between Oxy-Mb and Met-Mb is dramatic (illustrating bright red fresh meat vs. brown older meat), and method(s) used in this laboratory are simple, inexpensive, and non-harmful to the student.

Contamination control through filtration of microorganisms

NASA Technical Reports Server (NTRS)

Stabekis, P. D.; Lyle, R. G.

1972-01-01

A description is given of the various kinds of gas and liquid filters used in decontamination and sterilization procedures. Also discussed are filtration mechanisms, characteristics of filter materials, and the factors affecting filter performance. Summaries are included for filter testing and evaluation techniques and the possible application of the filters to spacecraft sterilization.

Onboard spectral imager data processor

NASA Astrophysics Data System (ADS)

Otten, Leonard J.; Meigs, Andrew D.; Franklin, Abraham J.; Sears, Robert D.; Robison, Mark W.; Rafert, J. Bruce; Fronterhouse, Donald C.; Grotbeck, Ronald L.

1999-10-01

Previous papers have described the concept behind the MightySat II.1 program, the satellite's Fourier Transform imaging spectrometer's optical design, the design for the spectral imaging payload, and its initial qualification testing. This paper discusses the on board data processing designed to reduce the amount of downloaded data by an order of magnitude and provide a demonstration of a smart spaceborne spectral imaging sensor. Two custom components, a spectral imager interface 6U VME card that moves data at over 30 MByte/sec, and four TI C-40 processors mounted to a second 6U VME and daughter card, are used to adapt the sensor to the spacecraft and provide the necessary high speed processing. A system architecture that offers both on board real time image processing and high-speed post data collection analysis of the spectral data has been developed. In addition to the on board processing of the raw data into a usable spectral data volume, one feature extraction technique has been incorporated. This algorithm operates on the basic interferometric data. The algorithm is integrated within the data compression process to search for uploadable feature descriptions.

Novel routes of albumin passage across the glomerular filtration barrier.

PubMed

Castrop, H; Schießl, I M

2017-03-01

Albuminuria is a hallmark of kidney diseases of various aetiologies and an unambiguous symptom of the compromised integrity of the glomerular filtration barrier. Furthermore, there is increasing evidence that albuminuria per se aggravates the development and progression of chronic kidney disease. This review covers new aspects of the movement of large plasma proteins across the glomerular filtration barrier in health and disease. Specifically, this review focuses on the role of endocytosis and transcytosis of albumin by podocytes, which constitutes a new pathway of plasma proteins across the filtration barrier. Thus, we summarize what is known about the mechanisms of albumin endocytosis by podocytes and address the fate of the endocytosed albumin, which is directed to lysosomal degradation or transcellular movement with subsequent vesicular release into the urinary space. We also address the functional consequences of overt albumin endocytosis by podocytes, such as the formation of pro-inflammatory cytokines, which might eventually result in a deterioration of podocyte function. Finally, we consider the diagnostic potential of podocyte-derived albumin-containing vesicles in the urine as an early marker of a compromised glomerular barrier function. In terms of new technical approaches, the review covers how our knowledge of the movement of albumin across the glomerular filtration barrier has expanded by the use of new intravital imaging techniques. © 2016 Scandinavian Physiological Society. Published by John Wiley & Sons Ltd.

Comparison of nonwoven fiberglass and stainless steel microfiber media in aerosol coalescence filtration

NASA Astrophysics Data System (ADS)

Manzo, Gabriel

Coalescing filters are used to remove small liquid droplets from air streams. They have numerous industrial applications including dehumidification, cabin air filtration, compressed air filtration, metal working, CCV, and agriculture. In compressed air systems, oils used for lubrication of compressor parts can aerosolize into the main air stream causing potential contamination concerns for downstream applications. In many systems, humid air can present problems to sensitive equipment and sensors. As the humid air cools, small water drops condense and can disrupt components that need to be kept dry. Fibrous nonwoven filter media are commonly used to coalesce small drops into larger drops for easier removal. The coalescing performance of a medium is dependent upon several parameters including permeability, porosity, and wettability. In many coalescing filters, glass fibers are used. In this work, the properties of steel fiber media are measured to see how these properties compare to glass fiber media. Steel fiber media has different permeability, porosity and wettability to oil and water than fiber glass media. These differences can impact coalescence performance. The impact of these differences in properties on coalescence filtration performance was evaluated in a coalescence test apparatus. The overall coalescence performance of the steel and glass nonwoven fiber media are compared using a filtration efficiency and filtration index. In many cases, the stainless steel media performed comparably to fiber glass media with efficiencies near 90%. Since stainless steel media had lower pressure drops than fiber glass media, its filtration index values were significantly higher. Broader impact of this work is the use of stainless steel fiber media as an alternative to fiber glass media in applications where aerosol filtration is needed to protect the environment or sensitive equipment and sensors.

Depot effect of bioactive components in experimental membrane filtrations

NASA Astrophysics Data System (ADS)

Mitev, D.; Peshev, D.; Peev, G.; Peeva, L.

2017-01-01

Depot effects were found to be accompanying phenomena of membrane separation processes. Accumulation of target species in the membrane matrix during feasibility tests can hamper proper conclusions or compromise the filtration results. Therefore, we investigated the effects of delayed membrane release of chlorogenic acid and caffeine, considered as key compounds of interest in spent coffee products’ recovery treatment. Permeate fluxes and key components release were studied in course of 24 hours via nanofiltration of pure solvent, both immediately after the mock solution filtration and after idle stay. Conclusions are drawn and recommendations advised for proper analysis of experimental data on membrane screening.

DEMONSTRATION BULLETIN: MEMBRANE FILTRATION - SBP TECHNOLOGIES, INC.

EPA Science Inventory

SBP Technologies Inc. (SBP) has developed a membrane-based separation technology that can reduce the volume of contaminated groundwater requiring treatment. The SBP Filtration Unit consists of porous, sintered, stainless steel tubes arranged in a shell-and-tube module configurati...

The quality of tumor size assessment by contrast-enhanced spectral mammography and the benefit of additional breast MRI.

PubMed

Lobbes, Marc B I; Lalji, Ulrich C; Nelemans, Patty J; Houben, Ivo; Smidt, Marjolein L; Heuts, Esther; de Vries, Bart; Wildberger, Joachim E; Beets-Tan, Regina G

2015-01-01

Background - Contrast-enhanced spectral mammography (CESM) is a promising new breast imaging modality that is superior to conventional mammography for breast cancer detection. We aimed to evaluate correlation and agreement of tumor size measurements using CESM. As additional analysis, we evaluated whether measurements using an additional breast MRI exam would yield more accurate results. Methods - Between January 1(st) 2013 and April 1(st) 2014, 87 consecutive breast cancer cases that underwent CESM were collected and data on maximum tumor size measurements were gathered. In 57 cases, tumor size measurements were also available for breast MRI. Histopathological results of the surgical specimen served as gold standard in all cases. Results - The Pearson's correlation coefficients (PCC) of CESM versus histopathology and breast MRI versus histopathology were all >0.9, p<0.0001. For the agreement between measurements, the mean difference between CESM and histopathology was 0.03 mm. The mean difference between breast MRI and histopathology was 2.12 mm. Using a 2x2 contingency table to assess the frequency distribution of a relevant size discrepancy of >1 cm between the two imaging modalities and histopathological results, we did not observe any advantage of performing an additional breast MRI after CESM in any of the cases. Conclusion - Quality of tumor size measurement using CESM is good and matches the quality of these measurement assessed by breast MRI. Additional measurements using breast MRI did not improve the quality of tumor size measurements.

The Quality of Tumor Size Assessment by Contrast-Enhanced Spectral Mammography and the Benefit of Additional Breast MRI

PubMed Central

Lobbes, Marc B.I.; Lalji, Ulrich C.; Nelemans, Patty J.; Houben, Ivo; Smidt, Marjolein L.; Heuts, Esther; de Vries, Bart; Wildberger, Joachim E.; Beets-Tan, Regina G.

2015-01-01

Background - Contrast-enhanced spectral mammography (CESM) is a promising new breast imaging modality that is superior to conventional mammography for breast cancer detection. We aimed to evaluate correlation and agreement of tumor size measurements using CESM. As additional analysis, we evaluated whether measurements using an additional breast MRI exam would yield more accurate results. Methods - Between January 1st 2013 and April 1st 2014, 87 consecutive breast cancer cases that underwent CESM were collected and data on maximum tumor size measurements were gathered. In 57 cases, tumor size measurements were also available for breast MRI. Histopathological results of the surgical specimen served as gold standard in all cases. Results - The Pearson's correlation coefficients (PCC) of CESM versus histopathology and breast MRI versus histopathology were all >0.9, p<0.0001. For the agreement between measurements, the mean difference between CESM and histopathology was 0.03 mm. The mean difference between breast MRI and histopathology was 2.12 mm. Using a 2x2 contingency table to assess the frequency distribution of a relevant size discrepancy of >1 cm between the two imaging modalities and histopathological results, we did not observe any advantage of performing an additional breast MRI after CESM in any of the cases. Conclusion - Quality of tumor size measurement using CESM is good and matches the quality of these measurement assessed by breast MRI. Additional measurements using breast MRI did not improve the quality of tumor size measurements. PMID:25561979

WE-FG-207B-04: Noise Suppression for Energy-Resolved CT Via Variance Weighted Non-Local Filtration

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

Harms, J; Zhu, L

Purpose: The photon starvation problem is exacerbated in energy-resolved CT, since the detected photons are shared by multiple energy channels. Using pixel similarity-based non-local filtration, we aim to produce accurate and high-resolution energy-resolved CT images with significantly reduced noise. Methods: Averaging CT images reconstructed from different energy channels reduces noise at the price of losing spectral information, while conventional denoising techniques inevitably degrade image resolution. Inspired by the fact that CT images of the same object at different energies share the same structures, we aim to reduce noise of energy-resolved CT by averaging only pixels of similar materials - amore » non-local filtration technique. For each CT image, an empirical exponential model is used to calculate the material similarity between two pixels based on their CT values and the similarity values are organized in a matrix form. A final similarity matrix is generated by averaging these similarity matrices, with weights inversely proportional to the estimated total noise variance in the sinogram of different energy channels. Noise suppression is achieved for each energy channel via multiplying the image vector by the similarity matrix. Results: Multiple scans on a tabletop CT system are used to simulate 6-channel energy-resolved CT, with energies ranging from 75 to 125 kVp. On a low-dose acquisition at 15 mA of the Catphan©600 phantom, our method achieves the same image spatial resolution as a high-dose scan at 80 mA with a noise standard deviation (STD) lower by a factor of >2. Compared with another non-local noise suppression algorithm (ndiNLM), the proposed algorithms obtains images with substantially improved resolution at the same level of noise reduction. Conclusion: We propose a noise-suppression method for energy-resolved CT. Our method takes full advantage of the additional structural information provided by energy-resolved CT and preserves image

Interactive remote data processing using Pixelize Wavelet Filtration (PWF-method) and PeriodMap analysis

NASA Astrophysics Data System (ADS)

Sych, Robert; Nakariakov, Valery; Anfinogentov, Sergey

Wavelet analysis is suitable for investigating waves and oscillating in solar atmosphere, which are limited in both time and frequency. We have developed an algorithms to detect this waves by use the Pixelize Wavelet Filtration (PWF-method). This method allows to obtain information about the presence of propagating and non-propagating waves in the data observation (cube images), and localize them precisely in time as well in space. We tested the algorithm and found that the results of coronal waves detection are consistent with those obtained by visual inspection. For fast exploration of the data cube, in addition, we applied early-developed Period- Map analysis. This method based on the Fast Fourier Transform and allows on initial stage quickly to look for "hot" regions with the peak harmonic oscillations and determine spatial distribution at the significant harmonics. We propose the detection procedure of coronal waves separate on two parts: at the first part, we apply the PeriodMap analysis (fast preparation) and than, at the second part, use information about spatial distribution of oscillation sources to apply the PWF-method (slow preparation). There are two possible algorithms working with the data: in automatic and hands-on operation mode. Firstly we use multiply PWF analysis as a preparation narrowband maps at frequency subbands multiply two and/or harmonic PWF analysis for separate harmonics in a spectrum. Secondly we manually select necessary spectral subband and temporal interval and than construct narrowband maps. For practical implementation of the proposed methods, we have developed the remote data processing system at Institute of Solar-Terrestrial Physics, Irkutsk. The system based on the data processing server - http://pwf.iszf.irk.ru. The main aim of this resource is calculation in remote access through the local and/or global network (Internet) narrowband maps of wave's sources both in whole spectral band and at significant harmonics. In addition

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

USDA-ARS?s Scientific Manuscript database

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...

The Spectral Shift Function and Spectral Flow

NASA Astrophysics Data System (ADS)

Azamov, N. A.; Carey, A. L.; Sukochev, F. A.

2007-11-01

At the 1974 International Congress, I. M. Singer proposed that eta invariants and hence spectral flow should be thought of as the integral of a one form. In the intervening years this idea has lead to many interesting developments in the study of both eta invariants and spectral flow. Using ideas of [24] Singer’s proposal was brought to an advanced level in [16] where a very general formula for spectral flow as the integral of a one form was produced in the framework of noncommutative geometry. This formula can be used for computing spectral flow in a general semifinite von Neumann algebra as described and reviewed in [5]. In the present paper we take the analytic approach to spectral flow much further by giving a large family of formulae for spectral flow between a pair of unbounded self-adjoint operators D and D + V with D having compact resolvent belonging to a general semifinite von Neumann algebra {mathcal{N}} and the perturbation V in {mathcal{N}} . In noncommutative geometry terms we remove summability hypotheses. This level of generality is made possible by introducing a new idea from [3]. There it was observed that M. G. Krein’s spectral shift function (in certain restricted cases with V trace class) computes spectral flow. The present paper extends Krein’s theory to the setting of semifinite spectral triples where D has compact resolvent belonging to {mathcal{N}} and V is any bounded self-adjoint operator in {mathcal{N}} . We give a definition of the spectral shift function under these hypotheses and show that it computes spectral flow. This is made possible by the understanding discovered in the present paper of the interplay between spectral shift function theory and the analytic theory of spectral flow. It is this interplay that enables us to take Singer’s idea much further to create a large class of one forms whose integrals calculate spectral flow. These advances depend critically on a new approach to the calculus of functions of non

ELECTROSTATIC ENHANCEMENT OF FABRIC FILTRATION OF FLY ASH AND SPRAY DRYER BY-PRODUCT

EPA Science Inventory

The paper describes small pilot-scale experiments, showing that the pressure drop increase during the fabric filtration of redispersed spray dryer by-product (chiefly calcium salts and fly ash) is significantly reduced by electrostatic enhancement of the filtration. The pressure ...

Plasma discharge self-cleaning filtration system

DOEpatents

Cho, Young I.; Fridman, Alexander; Gutsol, Alexander F.; Yang, Yong

2014-07-22

The present invention is directed to a novel method for cleaning a filter surface using a plasma discharge self-cleaning filtration system. The method involves utilizing plasma discharges to induce short electric pulses of nanoseconds duration at high voltages. These electrical pulses generate strong Shockwaves that disintegrate and dislodge particulate matter located on the surface of the filter.

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

Treesearch

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)

DTIC Science & Technology

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

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

NASA Astrophysics Data System (ADS)

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.

SpecViz: Interactive Spectral Data Analysis

NASA Astrophysics Data System (ADS)

Earl, Nicholas Michael; STScI

2016-06-01

The astronomical community is about to enter a new generation of scientific enterprise. With next-generation instrumentation and advanced capabilities, the need has arisen to equip astronomers with the necessary tools to deal with large, multi-faceted data. The Space Telescope Science Institute has initiated a data analysis forum for the creation, development, and maintenance of software tools for the interpretation of these new data sets. SpecViz is a spectral 1-D interactive visualization and analysis application built with Python in an open source development environment. A user-friendly GUI allows for a fast, interactive approach to spectral analysis. SpecViz supports handling of unique and instrument-specific data, incorporation of advanced spectral unit handling and conversions in a flexible, high-performance interactive plotting environment. Active spectral feature analysis is possible through interactive measurement and statistical tools. It can be used to build wide-band SEDs, with the capability of combining or overplotting data products from various instruments. SpecViz sports advanced toolsets for filtering and detrending spectral lines; identifying, isolating, and manipulating spectral features; as well as utilizing spectral templates for renormalizing data in an interactive way. SpecViz also includes a flexible model fitting toolset that allows for multi-component models, as well as custom models, to be used with various fitting and decomposition routines. SpecViz also features robust extension via custom data loaders and connection to the central communication system underneath the interface for more advanced control. Incorporation with Jupyter notebooks via connection with the active iPython kernel allows for SpecViz to be used in addition to a user’s normal workflow without demanding the user drastically alter their method of data analysis. In addition, SpecViz allows the interactive analysis of multi-object spectroscopy in the same straight

Influence of spectral resolution, spectral range and signal-to-noise ratio of Fourier transform infra-red spectra on identification of high explosive substances

NASA Astrophysics Data System (ADS)

Banas, Krzysztof; Banas, Agnieszka M.; Heussler, Sascha P.; Breese, Mark B. H.

2018-01-01

In the contemporary spectroscopy there is a trend to record spectra with the highest possible spectral resolution. This is clearly justified if the spectral features in the spectrum are very narrow (for example infra-red spectra of gas samples). However there is a plethora of samples (in the liquid and especially in the solid form) where there is a natural spectral peak broadening due to collisions and proximity predominately. Additionally there is a number of portable devices (spectrometers) with inherently restricted spectral resolution, spectral range or both, which are extremely useful in some field applications (archaeology, agriculture, food industry, cultural heritage, forensic science). In this paper the investigation of the influence of spectral resolution, spectral range and signal-to-noise ratio on the identification of high explosive substances by applying multivariate statistical methods on the Fourier transform infra-red spectral data sets is studied. All mathematical procedures on spectral data for dimension reduction, clustering and validation were implemented within R open source environment.

Effects of dilute-acid pretreatment conditions on filtration performance of corn stover hydrolyzate

DOE PAGES

Sievers, David A.; Kuhn, Erik M.; Tucker, Melvin P.; ...

2017-06-28

In this study, the reaction conditions used during dilute-acid pretreatment of lignocellulosic biomass control the carbohydrate digestion yield and also hydrolyzate properties. Depending on the conversion route of interest, solid-liquid separation (SLS) may be required to split the hemicellulose-rich liquor from the cellulose-rich insoluble solids, and slurry properties are important for SLS. Corn stover was pretreated at different reaction conditions and the slurries were assessed for conversion yield and filtration performance. Increasing pretreatment temperature reduced the solids mean particle size and resulted in slower slurry filtration rates when vacuum filtered or pressure filtered. Corn stover pretreated at 165 °C formore » 10 min and with 1% H 2SO 4 exhibited the highest xylose yield and best filtration performance with a no-wash filtration rate of 80 kg/h m 2 and cake permeability of 15 x 10 -15.« less

Effects of dilute-acid pretreatment conditions on filtration performance of corn stover hydrolyzate

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

Sievers, David A.; Kuhn, Erik M.; Tucker, Melvin P.

In this study, the reaction conditions used during dilute-acid pretreatment of lignocellulosic biomass control the carbohydrate digestion yield and also hydrolyzate properties. Depending on the conversion route of interest, solid-liquid separation (SLS) may be required to split the hemicellulose-rich liquor from the cellulose-rich insoluble solids, and slurry properties are important for SLS. Corn stover was pretreated at different reaction conditions and the slurries were assessed for conversion yield and filtration performance. Increasing pretreatment temperature reduced the solids mean particle size and resulted in slower slurry filtration rates when vacuum filtered or pressure filtered. Corn stover pretreated at 165 °C formore » 10 min and with 1% H 2SO 4 exhibited the highest xylose yield and best filtration performance with a no-wash filtration rate of 80 kg/h m 2 and cake permeability of 15 x 10 -15.« less

GPU-based cloud service for Smith-Waterman algorithm using frequency distance filtration scheme.

PubMed

Lee, Sheng-Ta; Lin, Chun-Yuan; Hung, Che Lun

2013-01-01

As the conventional means of analyzing the similarity between a query sequence and database sequences, the Smith-Waterman algorithm is feasible for a database search owing to its high sensitivity. However, this algorithm is still quite time consuming. CUDA programming can improve computations efficiently by using the computational power of massive computing hardware as graphics processing units (GPUs). This work presents a novel Smith-Waterman algorithm with a frequency-based filtration method on GPUs rather than merely accelerating the comparisons yet expending computational resources to handle such unnecessary comparisons. A user friendly interface is also designed for potential cloud server applications with GPUs. Additionally, two data sets, H1N1 protein sequences (query sequence set) and human protein database (database set), are selected, followed by a comparison of CUDA-SW and CUDA-SW with the filtration method, referred to herein as CUDA-SWf. Experimental results indicate that reducing unnecessary sequence alignments can improve the computational time by up to 41%. Importantly, by using CUDA-SWf as a cloud service, this application can be accessed from any computing environment of a device with an Internet connection without time constraints.

Efficient and reusable polyamide-56 nanofiber/nets membrane with bimodal structures for air filtration.

PubMed

Liu, Bowen; Zhang, Shichao; Wang, Xueli; Yu, Jianyong; Ding, Bin

2015-11-01

Nanofibrous media that both possess high airborne particle interception efficiency and robust air permeability would have broad technological implications for areas ranging from individual protection and industrial security to environmental governance; however, creating such filtration media has proved extremely challenging. Here we report a strategy to construct the bio-based polyamide-56 nanofiber/nets (PA-56 NFN) membranes with bimodal structures for effective air filtration via one-step electrospinning/netting. The PA-56 membranes are composed of completely covered two-dimensional (2D) ultrathin (∼20 nm) nanonets which are optimized by facilely regulating the solution concentration, and the bonded scaffold fibers constructed cavity structures which are synchronously created by using the CH3COOH inspiration. With integrated properties of small aperture, high porosity, and bonded scaffold, the resulting PA-56 NFN membranes exhibit high filtration efficiency of 99.995%, low pressure drop of 111 Pa, combined with large dust holding capacity of 49 g/m(2) and dust-cleaning regeneration ability, for filtrating ultrafine airborne particles in the most safe manner involving sieving principle and surface filtration. The successful synthesis of PA-56 NFN medium would not only make it a promising candidate for air filtration, but also provide new insights into the design and development of nanonet-based bimodal structures for various applications. Copyright © 2015 Elsevier Inc. All rights reserved.

Comparative Recoveries of Naegleria fowleri Amoebae from Seeded River Water by Filtration and Centrifugation

PubMed Central

Pernin, P.; Pélandakis, M.; Rouby, Y.; Faure, A.; Siclet, F.

1998-01-01

Detection of pathogenic Naegleria fowleri in environmental water samples, which is necessary for the prevention of primary amoebic meningoencephalitis, generally requires concentrating the samples. Two concentration techniques, filtration and centrifugation, were used to study the recovery of N. fowleri, in vegetative or cystic form, that had been mixed with the two other thermotolerant Naegleria species, N. lovaniensis and N. australiensis. Counting of amoebae was performed by the most probable number method on 10 water replicates of 100 ml and 10 ml each. With both concentration methods, recovery was better for cysts than for trophozoites (53% ± 21% versus 5% ± 5% by filtration and 57% ± 25% versus 22% ± 5% by centrifugation). The recovery of Naegleria trophozoites by filtration was very low, and centrifugation was significantly better than filtration in recovery of Naegleria trophozoites (22% ± 5% versus 5% ± 5%; P < 0.001). For cysts, however, filtration appeared as efficient as centrifugation, with equivalent values for recovery (53% ± 21% versus 57% ± 25%; P > 0.7). Although the recovery of cysts of N. fowleri obtained by filtration (51% ± 24%) appeared higher than that by centrifugation (36% ± 23%), the difference was not significant (P > 0.1). Both concentration methods have highly variable recovery rates, making accurate quantification of low concentrations (<100/liter) of N. fowleri in the environment difficult. PMID:9501435

Synthetic Hounsfield units from spectral CT data

NASA Astrophysics Data System (ADS)

Bornefalk, Hans

2012-04-01

Beam-hardening-free synthetic images with absolute CT numbers that radiologists are used to can be constructed from spectral CT data by forming ‘dichromatic’ images after basis decomposition. The CT numbers are accurate for all tissues and the method does not require additional reconstruction. This method prevents radiologists from having to relearn new rules-of-thumb regarding absolute CT numbers for various organs and conditions as conventional CT is replaced by spectral CT. Displaying the synthetic Hounsfield unit images side-by-side with images reconstructed for optimal detectability for a certain task can ease the transition from conventional to spectral CT.

Novel approaches to address spectral distortions in photon counting x-ray CT using artificial neural networks

NASA Astrophysics Data System (ADS)

Touch, M.; Clark, D. P.; Barber, W.; Badea, C. T.

2016-04-01

Spectral CT using a photon-counting x-ray detector (PCXD) can potentially increase accuracy of measuring tissue composition. However, PCXD spectral measurements suffer from distortion due to charge sharing, pulse pileup, and Kescape energy loss. This study proposes two novel artificial neural network (ANN)-based algorithms: one to model and compensate for the distortion, and another one to directly correct for the distortion. The ANN-based distortion model was obtained by training to learn the distortion from a set of projections with a calibration scan. The ANN distortion was then applied in the forward statistical model to compensate for distortion in the projection decomposition. ANN was also used to learn to correct distortions directly in projections. The resulting corrected projections were used for reconstructing the image, denoising via joint bilateral filtration, and decomposition into three-material basis functions: Compton scattering, the photoelectric effect, and iodine. The ANN-based distortion model proved to be more robust to noise and worked better compared to using an imperfect parametric distortion model. In the presence of noise, the mean relative errors in iodine concentration estimation were 11.82% (ANN distortion model) and 16.72% (parametric model). With distortion correction, the mean relative error in iodine concentration estimation was improved by 50% over direct decomposition from distorted data. With our joint bilateral filtration, the resulting material image quality and iodine detectability as defined by the contrast-to-noise ratio were greatly enhanced allowing iodine concentrations as low as 2 mg/ml to be detected. Future work will be dedicated to experimental evaluation of our ANN-based methods using 3D-printed phantoms.

Impact of different supply air and recirculating air filtration systems on stable climate, animal health, and performance of fattening pigs in a commercial pig farm

PubMed Central

Wenke, Cindy; Pospiech, Janina; Reutter, Tobias; Altmann, Bettina; Truyen, Uwe

2018-01-01

Biosecurity is defined as the implementation of measures that reduce the risk of disease agents being introduced and/or spread. For pig production, several of these measures are routinely implemented (e.g. cleaning, disinfection, segregation). However, air as a potential vector of pathogens has long been disregarded. Filters for incoming and recirculating air were installed into an already existing ventilation plant at a fattening piggery (3,840 pigs at maximum) in Saxony, Germany. Over a period of three consecutive fattening periods, we evaluated various parameters including air quality indices, environmental and operating parameters, and pig performance. Animal data regarding respiratory diseases, presence of antibodies against influenza A viruses, PRRSV, and Actinobacillus pleuropneumoniae and lung health score at slaughter were recorded, additionally. There were no significant differences (p = 0.824) in total bacterial counts between barns with and without air filtration. Recirculating air filtration resulted in the lowest total dust concentration (0.12 mg/m3) and lung health was best in animals from the barn equipped with recirculating air filtration modules. However, there was no difference in animal performance. Antibodies against all above mentioned pathogens were detected but mostly animals were already antibody-positive at re-stocking. We demonstrated that supply air filtration as well as recirculating air filtration technique can easily be implemented in an already existing ventilation system and that recirculating air filtration resulted in enhanced lung health compared to supply air-filtered and non-filtered barns. A more prominent effect might have been obtained in a breeding facility because of the longer life span of sows and a higher biosecurity level with air filtration as an add-on measure. PMID:29558482

Measurement of filtration rates by infaunal bivalves in a recirculating flume

USGS Publications Warehouse

Cole, B.E.; Thompson, J.K.; Cloern, J.E.

1992-01-01

A flume system and protocol for measuring the filtration rate of infaunal bivalves is described. Assemblages of multi-sized clams, at natural densities and in normal filter-feeding positions, removed phytoplankton suspended in a unidirectional flow of water. The free-stream velocity and friction velocity of the flow, and bottom roughness height were similar to those in natural estuarine waters. Continuous variations in phytoplankton (Chroomonas salinay) cell density were used to measure the filtration rate of the suspension-feeding clam Potamocorbula amurensis for periods of 2 to 28 h. Filtration rates of P. amurensis varied from 100 to 580 liters (gd)-1 over a free-stream velocity range of 9 to 25 cm s-1. Phytoplankton loss rates were usually constant throughout the experiments. Our results suggest that suspension-feeding by infaunal bivalves is sensitive to flow velocity. ?? 1992 Springer-Verlag.

The monitoring of antigen levels during inactivated poliovirus vaccine production: evaluation of filtration techniques.

PubMed

Moynihan, M; Petersen, I

1981-01-01

The use of ELISA to estimate poliovirus antigen concentration has permitted an evaluation of the methodology used in vaccine production and allowed exploration of less wasteful filtration-techniques. The replacement of Seitz-EKS-1B filtration with either Seitz-Supra-EKS or Pall-filtration in the preparation of the vaccine could make a large saving in the total antigen yield, but the results in the safety test excluded their possible use in our process as it stands at the moment.

Field Assessment of Enclosed Cab Filtration System Performance Using Particle Counting Measurements

PubMed Central

Organiscak, John A.; Cecala, Andrew B.; Noll, James D.

2015-01-01

Enclosed cab filtration systems are typically used on mobile mining equipment to reduce miners’ exposure to airborne dust generated during mining operations. The National Institute for Occupational Safety and Health (NIOSH) Office of Mine Safety and Health Research (OMSHR) has recently worked with a mining equipment manufacturer to examine a new cab filtration system design for underground industrial minerals equipment. This cab filtration system uses a combination of three particulate filters to reduce equipment operators’ exposure to dust and diesel particulates present in underground industrial mineral mines. NIOSH initially examined this cab filtration system using a two-instrument particle counting method at the equipment company’s manufacturing shop facility to assess several alternative filters. This cab filtration system design was further studied on several pieces of equipment during a two- to seven-month period at two underground limestone mines. The two-instrument particle counting method was used outside the underground mine at the end of the production shifts to regularly test the cabs’ long-term protection factor performance with particulates present in the ambient air. This particle counting method showed that three of the four cabs achieved protection factors greater than 1,000 during the field studies. The fourth cab did not perform at this level because it had a damaged filter in the system. The particle counting measurements of submicron particles present in the ambient air were shown to be a timely and useful quantification method in assessing cab performance during these field studies. PMID:23915268

Surface patterning of polymeric separation membranes and its influence on the filtration performance

NASA Astrophysics Data System (ADS)

Maruf, Sajjad

Polymeric membrane based separation technologies are crucial for addressing the global issues such as water purification. However, continuous operations of these processes are often hindered by fouling which increases mass transport resistance of the membrane to permeation and thus the energy cost, and eventually replacement of the membrane in the system. In comparison to other anti-fouling strategies, the use of controlled surface topography to mitigate fouling has not been realized mainly due to the lack of methods to create targeted topography on the porous membrane surface. This thesis aims to develop a new methodology to create surface-patterned polymeric separation membrane to improve their anti-fouling characteristics during filtration. First, successful fabrication of sub-micron surface patterns directly on a commercial ultrafiltration (UF) membrane surface using nanoimprint lithographic (NIL) technique was demonstrated. Comprehensive filtration studies revealed that the presence of these sub-micron surface patterns mitigates not only the onset of colloidal particle deposition, but also lowers the rate of growth of cake layer after initial deposition, in comparison with un-patterned membranes. The anti-fouling effects were also observed for model protein solutions. Staged filtration experiments, with backwash cleaning, revealed that the permeate flux of the patterned membrane after protein fouling was considerably higher than that of the pristine or un-patterned membrane. In addition to the surface-patterning of UF membranes, successful fabrication of a surface-patterned thin film composite (TFC) membrane was shown for the first time. A two-step fabrication process was carried out by (1) nanoimprinting a polyethersulfone (PES) support using NIL, and (2) forming a thin dense film atop the PES support via interfacial polymerization (IP). Fouling experiments suggest that the surface patterns alter the hydrodynamics at the membrane-feed interface, which is

Membrane filtration method for enumeration and isolation of Alicyclobacillus spp. from apple juice.

PubMed

Lee, S-Y; Chang, S-S; Shin, J-H; Kang, D-H

2007-11-01

To evaluate the applicability of filtration membranes for detecting Alicyclobacillus spp. spores in apple juice. Ten types of nitrocellulose membrane filters from five manufacturers were used to collect and enumerate five Alicyclobacillus spore isolates and results were compared to conventional K agar plating. Spore recovery differed among filters with an average recovery rate of 126.2%. Recovery levels also differed among spore isolates. Although significant difference (P < 0.05) in spore sizes existed, no correlation could be determined between spore size and membrane filter recovery rate. Recovery of spores using membrane filtration is dependent on the manufacturer and filter pore size. Correlations between spore recovery rate and spore size could not be determined. Low numbers of Alicyclobacillus spores in juice can be effectively detected using membrane filtration although recovery rate differences exist among different manufacturers. Use of membrane filtration is a simple, fast alternative to the week-long enrichment procedures currently employed in most quality assurance tests.

[The aspiratory resistance and filtration penetration of N95 filtering-facepiece respirators used widely in China].

PubMed

Wang, Xinyan; Shi, Tingming; Lu, Wei; Qin, Shaoxian; Liu, Yuewei; Tao, Ying; Zhang, Hongge; Chen, Weihong

2015-01-01

The objective of this study was to investigate the aspiratory resistance, filtration penetration and their influence factors of N95 filtering-facepiece respirators used widely in China. The total of 6 brands and 21 models of N95 filtering-facepiece respirators which are certified and big sales on the market. The aspiratory resistance and filtration efficiency filter penetration were measured while air pump ran from 10 L/min to 100 L/min using differential pressure gauge and the PortaCount, respectively. The filtration penetrations for 2 of the 21 models were lower than 95%, and the qualified rate for all models was 90.47%. The filtration penetrations gradually decreased when ventilation flow of air pump increased. The negative correlation was observed between filtration penetration and ventilation flow (r(2) = 0.711, P < 0.05). The resistances of all 21 models of N95 respirators met the requirements of the national standard. The aspiratory resistance started to elevate with the increasing of ventilation flow, and a positive correlation between both (r(2) = 0.878, P < 0.05). Significant differences of filtration penetration and aspiratory resistance were observed among between different brands (P < 0.05) although no differences of filtration penetration existed among different models of one brand (P > 0.05). But the differences of the aspiratory resistance among different models of one brand were statistically significant (P < 0.05). The aspiratory resistances of all N95 filtering-facepiece respirators used in this study met the requirements of the national standard. And the qualified ratio of filtration penetration of all models was higher than 90%. The influencing factors of aspiratory resistance included materials, size and ventilation flow. And influencing factors for filtration penetration were materials and ventilation flow.

[Exceptional production of leukocyte-free erythrocyte concentrates using filtration with the BPF 4 BBS leukocyte filter].

PubMed

Zimmermann, B; Hillringhaus, I; Diekamp, U

1994-01-01

Leukocyte depletion prevents some undesirable effects of red cell transfusions. We evaluated the blood filter system BPF 4 BBS (PALL) by filtering 26 units of buffy coat-free red cell concentrates, prepared from 500 ml of whole blood and suspended in SAG-M-additive solution, over 8 min within 48 h after donation at room temperature. Filtration reduced the leukocyte content by more than 99.99% in 25 of the 26 units examined. In 20 instances, no leukocyte was found in the Nageotte counting chamber (2 x 50 microliters) corresponding to a total leukocyte count below 2.38 x 10(4). In 5 instances a single leukocyte was seen, corresponding to a total leukocyte count of (2.35 +/- 0.01) x 10(4). One unit contained 2.93 x 10(5) leukocytes after filtration, corresponding to a 99.98% leukocyte reduction. Red cell recovery was 92.5 +/- 3.8%. This system is well suited for routine use.

Design of combination biofilter and subsurface constructed wetland-multilayer filtration with vertical flow type using Vetiveria zizanioides (akar wangi)

NASA Astrophysics Data System (ADS)

Astuti, A. D.; Lindu, M.; Yanidar, R.; Faruq, M.

2018-01-01

As environmental regulation has become stricter in recent years, there is an increasing concern about the issue of wastewater treatment in urban areas. Senior High School as center of student activity has a potential source to generated domestic wastewater from toilet, bathroom and canteen. Canteen wastewater contains high-organic content that to be treated before discharged. Based on previous research the subsurface constructed wetland-multilayer filtration with vertical flow is an attractive alternative to provide efficient treatment of canteen wastewater. The effluent concentration complied with regulation according to [9]. Due to limited land, addition of preliminary treatment such as the presence of biofilter was found to improve the performance. The aim of this study was to design combination biofilter and subsurface constructed wetland-multilayer filtration with vertical flow type using vetiveria zizanioides (akar wangi) treating canteen wastewater. Vetiveria zizanioides (akar wangi) is used because from previous research, subsurface constructed wetland-multilayer filtration (SCW-MLF) with vertical flow type using vetiveria zizanioides (akar wangi) can be an alternative canteen wastewater treatment that is uncomplicated in technology, low cost in operational and have a beautiful landscape view, besides no odors or insects were presented during the operation.

Spectral optimization for micro-CT

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

Hupfer, Martin; Nowak, Tristan; Brauweiler, Robert

2012-06-15

Purpose: To optimize micro-CT protocols with respect to x-ray spectra and thereby reduce radiation dose at unimpaired image quality. Methods: Simulations were performed to assess image contrast, noise, and radiation dose for different imaging tasks. The figure of merit used to determine the optimal spectrum was the dose-weighted contrast-to-noise ratio (CNRD). Both optimal photon energy and tube voltage were considered. Three different types of filtration were investigated for polychromatic x-ray spectra: 0.5 mm Al, 3.0 mm Al, and 0.2 mm Cu. Phantoms consisted of water cylinders of 20, 32, and 50 mm in diameter with a central insert of 9more » mm which was filled with different contrast materials: an iodine-based contrast medium (CM) to mimic contrast-enhanced (CE) imaging, hydroxyapatite to mimic bone structures, and water with reduced density to mimic soft tissue contrast. Validation measurements were conducted on a commercially available micro-CT scanner using phantoms consisting of water-equivalent plastics. Measurements on a mouse cadaver were performed to assess potential artifacts like beam hardening and to further validate simulation results. Results: The optimal photon energy for CE imaging was found at 34 keV. For bone imaging, optimal energies were 17, 20, and 23 keV for the 20, 32, and 50 mm phantom, respectively. For density differences, optimal energies varied between 18 and 50 keV for the 20 and 50 mm phantom, respectively. For the 32 mm phantom and density differences, CNRD was found to be constant within 2.5% for the energy range of 21-60 keV. For polychromatic spectra and CMs, optimal settings were 50 kV with 0.2 mm Cu filtration, allowing for a dose reduction of 58% compared to the optimal setting for 0.5 mm Al filtration. For bone imaging, optimal tube voltages were below 35 kV. For soft tissue imaging, optimal tube settings strongly depended on phantom size. For 20 mm, low voltages were preferred. For 32 mm, CNRD was found to be almost

Spectral optimization for micro-CT.

PubMed

Hupfer, Martin; Nowak, Tristan; Brauweiler, Robert; Eisa, Fabian; Kalender, Willi A

2012-06-01

To optimize micro-CT protocols with respect to x-ray spectra and thereby reduce radiation dose at unimpaired image quality. Simulations were performed to assess image contrast, noise, and radiation dose for different imaging tasks. The figure of merit used to determine the optimal spectrum was the dose-weighted contrast-to-noise ratio (CNRD). Both optimal photon energy and tube voltage were considered. Three different types of filtration were investigated for polychromatic x-ray spectra: 0.5 mm Al, 3.0 mm Al, and 0.2 mm Cu. Phantoms consisted of water cylinders of 20, 32, and 50 mm in diameter with a central insert of 9 mm which was filled with different contrast materials: an iodine-based contrast medium (CM) to mimic contrast-enhanced (CE) imaging, hydroxyapatite to mimic bone structures, and water with reduced density to mimic soft tissue contrast. Validation measurements were conducted on a commercially available micro-CT scanner using phantoms consisting of water-equivalent plastics. Measurements on a mouse cadaver were performed to assess potential artifacts like beam hardening and to further validate simulation results. The optimal photon energy for CE imaging was found at 34 keV. For bone imaging, optimal energies were 17, 20, and 23 keV for the 20, 32, and 50 mm phantom, respectively. For density differences, optimal energies varied between 18 and 50 keV for the 20 and 50 mm phantom, respectively. For the 32 mm phantom and density differences, CNRD was found to be constant within 2.5% for the energy range of 21-60 keV. For polychromatic spectra and CMs, optimal settings were 50 kV with 0.2 mm Cu filtration, allowing for a dose reduction of 58% compared to the optimal setting for 0.5 mm Al filtration. For bone imaging, optimal tube voltages were below 35 kV. For soft tissue imaging, optimal tube settings strongly depended on phantom size. For 20 mm, low voltages were preferred. For 32 mm, CNRD was found to be almost independent of tube voltage. For 50 mm

Modification of the TASMIP x-ray spectral model for the simulation of microfocus x-ray sources

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

Sisniega, A.; Vaquero, J. J., E-mail: juanjose.vaquero@uc3m.es; Instituto de Investigación Sanitaria Gregorio Marañón, Madrid ES28007

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, modifiedmore » 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

Research on Hydrophilic Nature of Polyvinylpyrrolidone on Polysulfone Membrane Filtration

NASA Astrophysics Data System (ADS)

Tiron, L. G.; Vlad, M.; Baltă, Ş.

2018-06-01

The membranes used in wastewater filtration are obtained from polymers, this technique is widely applied because of the small installations and low costs as against conventional systems. The polymeric membranes have high mechanical strength and flexibility, but is a challenge to improve in the same time the permeability and retention capacity of the membranes. A process that can improve the membrane properties is the addition of additives to the polymer solution, resulting in noticeable changes in the resulting membrane structure. Polyvinylpyrrolidone (PVP) is a highly hydrophilic polymer, used as a food additive that acts as stabilizer and thickening agent, which brings improvements in membrane properties. This study analyses the effect of polyvinylpyrrolidone (PVP) on the casting solution of the prepared membranes. The polymer solution was prepared from polysulfone (PSf) and N-methyl-2-pyrrolidone (NMP) at different concentrations. The membranes were obtained by phase inversion method. The PSf/PVP/NMP membranes with different concentrations were characterized by contact angle measurements, surface roughness, morphological structure and permeation tests. The results show that the hydrophilic nature of PVP improve the pure water flux, the contact angle and exhibit a higher anti-fouling property.

Infrared Spectral Signatures for Io's Dark and Green Spots

NASA Technical Reports Server (NTRS)

Granahan, J. C.; Fanale, F. P.; Carlson, R.; Smythe, W. D.

2001-01-01

This spectral study of Io identifies the infrared components of the visible spectral units (green and dark) as identified by Galileo. The green units possess sulfur dioxide and the dark units are associated with infrared thermal signatures. Additional information is contained in the original extended abstract.

Shuttle filter study. Volume 1: Characterization and optimization of filtration devices

NASA Technical Reports Server (NTRS)

1974-01-01

A program to develop a new technology base for filtration equipment and comprehensive fluid particulate contamination management techniques was conducted. The study has application to the systems used in the space shuttle and space station projects. The scope of the program is as follows: (1) characterization and optimization of filtration devices, (2) characterization of contaminant generation and contaminant sensitivity at the component level, and (3) development of a comprehensive particulate contamination management plane for space shuttle fluid systems.

Length filtration of the separable states.

PubMed

Chen, Lin; Ðoković, Dragomir Ž

2016-11-01

We investigate the separable states ρ of an arbitrary multi-partite quantum system with Hilbert space [Formula: see text] of dimension d . The length L ( ρ ) of ρ is defined as the smallest number of pure product states having ρ as their mixture. The length filtration of the set of separable states, [Formula: see text], is the increasing chain [Formula: see text], where [Formula: see text]. We define the maximum length, [Formula: see text], critical length, L crit , and yet another special length, L c , which was defined by a simple formula in one of our previous papers. The critical length indicates the first term in the length filtration whose dimension is equal to [Formula: see text]. We show that in general d ≤ L c ≤ L crit ≤ L max ≤ d 2 . We conjecture that the equality L crit = L c holds for all finite-dimensional multi-partite quantum systems. Our main result is that L crit = L c for the bipartite systems having a single qubit as one of the parties. This is accomplished by computing the rank of the Jacobian matrix of a suitable map having [Formula: see text] as its range.

Antimicrobial nanoparticle-coated electrostatic air filter with high filtration efficiency and low pressure drop.

PubMed

Sim, Kyoung Mi; Park, Hyun-Seol; Bae, Gwi-Nam; Jung, Jae Hee

2015-11-15

In this study, we demonstrated an antimicrobial nanoparticle-coated electrostatic (ES) air filter. Antimicrobial natural-product Sophora flavescens nanoparticles were produced using an aerosol process, and were continuously deposited onto the surface of air filter media. For the electrostatic activation of the filter medium, a corona discharge electrification system was used before and after antimicrobial treatment of the filter. In the antimicrobial treatment process, the deposition efficiency of S. flavescens nanoparticles on the ES filter was ~12% higher than that on the pristine (Non-ES) filter. In the evaluation of filtration performance using test particles (a nanosized KCl aerosol and submicron-sized Staphylococcus epidermidis bioaerosol), the ES filter showed better filtration efficiency than the Non-ES filter. However, antimicrobial treatment with S. flavescens nanoparticles affected the filtration efficiency of the filter differently depending on the size of the test particles. While the filtration efficiency of the KCl nanoparticles was reduced on the ES filter after the antimicrobial treatment, the filtration efficiency was improved after the recharging process. In summary, we prepared an antimicrobial ES air filter with >99% antimicrobial activity, ~92.5% filtration efficiency (for a 300-nm KCl aerosol), and a ~0.8 mmAq pressure drop (at 13 cm/s). This study provides valuable information for the development of a hybrid air purification system that can serve various functions and be used in an indoor environment. Copyright © 2015 Elsevier B.V. All rights reserved.

Removal of benzocaine from water by filtration with activated carbon

USGS Publications Warehouse

Howe, G.E.; Bills, T.D.; Marking, L.L.

1990-01-01

Benzocaine is a promising candidate for registration with the U.S. Food and Drug Administration for use as an anesthetic in fish culture, management, and research. A method for the removal of benzocaine from hatchery effluents could speed registration of this drug by eliminating requirements for data on its residues, tolerances, detoxification, and environmental hazards. Carbon filtration effectively removes many organic compounds from water. This study tested the effectiveness of three types of activated carbon for removing benzocaine from water by column filtration under controlled laboratory conditions. An adsorptive capacity was calculated for each type of activated carbon. Filtrasorb 400 (12 x 40 mesh; U.S. standard sieve series) showed the greatest capacity for benzocaine adsorption (76.12 mg benzocaine/g carbon); Filtrasorb 300 (8 x 30 mesh) ranked next (31.93 mg/g); and Filtrasorb 816 (8 x 16 mesh) absorbed the least (1.0 mg/g). Increased adsorptive capacity was associated with smaller carbon particle size; however, smaller particle size also impeded column flow. Carbon filtration is a practical means for removing benzocaine from treated water.

Structural changes of deposited casein micelles induced by membrane filtration.

PubMed

Gebhardt, R; Steinhauer, T; Meyer, P; Sterr, J; Perlich, J; Kulozik, U

2012-01-01

Casein micelles undergo shape changes when subjected to frontal filtration forces. Grazing incidence small angle X-ray scattering (GISAXS) and atomic force microscopy (AFM) allow a quantification of such structural changes on filtration cakes deposited on smooth silicon micro-sieves. A trans-membrane pressure of deltap = 400 mbar across the micro-sieve leads to an immediate film formation after deposition of casein solution. We observe significant changes in the GISAXS pattern depending on how many layers are stacked on top of each other. Compared to a deposit formed by one layer, GISAXS on a deposit formed by three layers of casein micelles leads to less scattering in the vertical and more scattering in the horizontal direction. Simulations show that the experimental results can be interpreted by a structural transformation from an originally spherical micelle shape to an ellipsoidal-deformed shape. The results are supported by AFM measurements showing a reduced lateral size of casein micelles deposited on top of a membrane pore. The observed shape changes could be due to filtration forces acting on densely packed deposits confining the micelles into ellipsoidal shapes.

Toward standardized test methods to determine the effectiveness of filtration media against airborne nanoparticles

NASA Astrophysics Data System (ADS)

Wang, Jing; Tronville, Paolo

2014-06-01

The filtration of airborne nanoparticles is an important control technique as the environmental, health, and safety impacts of nanomaterials grow. A review of the literature shows that significant progress has been made on airborne nanoparticle filtration in the academic field in the recent years. We summarize the filtration mechanisms of fibrous and membrane filters; the air flow resistance and filter media figure of merit are discussed. Our review focuses on the air filtration test methods and instrumentation necessary to implement them; recent experimental studies are summarized accordingly. Two methods using monodisperse and polydisperse challenging aerosols, respectively, are discussed in detail. Our survey shows that the commercial instruments are already available for generating a large amount of nanoparticles, sizing, and quantifying them accurately. The commercial self-contained filter test systems provide the possibility of measurement for particles down to 15 nm. Current international standards dealing with efficiency test for filters and filter media focus on measurement of the minimum efficiency at the most penetrating particle size. The available knowledge and instruments provide a solid base for development of test methods to determine the effectiveness of filtration media against airborne nanoparticles down to single-digit nanometer range.

Development and evaluation of low cost honey heating-cum-filtration system.

PubMed

Alam, Md Shafiq; Sharma, D K; Sehgal, V K; Arora, M; Bhatia, S

2014-11-01

A fully mechanized honey heating-cum-filtration system was designed, developed, fabricated and evaluated for its performance. The system comprised of two sections; the top heating section and the lower filtering section. The developed system was evaluated for its performance at different process conditions (25 kg and 50 kg capacity using processing condition: 50 °C heating temperature and 60 °C heating temperature with 20 and 40 min holding time, respectively) and it was found that the total time required for heating, holding and filtration of honey was 108 and 142 min for 25 kg and 50 kg capacity of machine, respectively, irrespective of the processing conditions. The optimum capacity of the system was found to be 50 kg and it involved an investment of Rs 40,000 for its fabrication. The honey filtered through the developed filtration system was compared with the honey filtered in a high cost honey processing plant and raw honey for its microbial and biochemical (reducing sugars (%), moisture, acidity and pH) quality attributes. It was observed that the process of filtering through the developed unit resulted in reduction of microbes. The microbiological quality of honey filtered through the developed filtration system was better than that of raw honey and commercially processed honey. The treatment conditions found best in context of microbiological counts were 60 °C temperature for 20 min. There was 1.97 fold reductions in the plate count and 2.14 reductions in the fungal count of honey processed through the developed filtration system as compared to the raw honey. No coliforms were found in the processed honey. Honey processed through developed unit witnessed less moisture content, acidity and more reducing sugars as compared to raw honey, whereas its quality was comparable to the commercially processed honey.

Exploration of PM2.5 filtration property of filter bag for environment protection

NASA Astrophysics Data System (ADS)

Zhu, Ruitian; Zheng, Jinwei; Ni, Bingxuan; Zhang, Peng

2017-06-01

In this paper, filter bag of polyphenylene sulfide (PPS) needle punched nonwoven for environment protection was investigated. The results showed that air permeability of sample was linear rise with the increase of the pressure drop. During the testing process, the residual pressure drop rose with the increase of cycles because of test dust attaching on the surface of the filter. The PM2.5 filtration efficiency was obtained of 99.854%, which was smaller than the dust filtration efficiency of 99.971% because of the fine particles taking larger proportion of the dust through the sample. Results show that this method of evaluating the PM2.5 filtration property is feasible.

Emergency field water supply system using natural filtration elements

NASA Astrophysics Data System (ADS)

Vikneswaran, M.; Yahya, Muhamad Azani; Yusof, Mohammed Alias; Ismail, Siti Nor Kamariah

2018-02-01

Water is the most important resource in times of emergency and during military missions. In addition, if there is a war in a country, sources of clean water are essential for life. But, the safety and cleanliness of the river water for the campers and hikers still uncertain. Usually, polluted and contaminated river water is not safe to be directly consumed by human. However, this problem can be partly resolved by using water filter where the river water can be consumed directly after the filtration process. In respect of that, this study was conducted to design the filter media for personal water purification system. Hence, the objective of this work also is to develop a personal, portable dual purpose handy water filter to provide an easier way to get safe, clean and healthy drinking water for human wherever they go. The water quality of samples collected before and after filtration were analyzed. Water samples were taken from a waterfall near Lestari Block and Lake beside Marine Centre UPNM Campus. The experimental results were analyzed based on the assessment of water quality parameters. Overall, the analysis of the results showed that the water filter was designed with basic mix tabs aqua filter water purification tablets is showing a better result where it achieve the class I of water quality index (WQI). In details, the water sample taken from waterfall near Lestari Block shown the WQI around 93 which is higher than WQI of water sample from Lake near Marine Centre UPNM which is 86, class II A which can be used for external purpose only.

Nocturnal polyuria is related to absent circadian rhythm of glomerular filtration rate.

PubMed

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.

Importance of filter’s microstructure in dynamic filtration modeling of gasoline particulate filters (GPFs): Inhomogeneous porosity and pore size distribution

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

Gong, Jian; Stewart, Mark L.; Zelenyuk, Alla

The state-of-the-art multiscale modeling of GPFs including channel scale, wall scale, and pore scale is described. The microstructures of two GPFs were experimentally characterized. The pore size distributions of the GPFs were determined by mercury porosimetry. The porosity was measured by X-ray computed tomography (CT) and found to be inhomogeneous across the substrate wall. The significance of pore size distribution with respect to filtration performance was analyzed. The predictions of filtration efficiency were improved by including the pore size distribution in the filtration model. A dynamic heterogeneous multiscale filtration (HMF) model was utilized to simulate particulate filtration on a singlemore » channel particulate filter with realistic particulate emissions from a spark-ignition direct-injection (SIDI) gasoline engine. The dynamic evolution of filter’s microstructure and macroscopic filtration characteristics including mass- and number-based filtration efficiencies and pressure drop were predicted and discussed. The microstructure of the GPF substrate including inhomogeneous porosity and pore size distribution is found to significantly influence local particulate deposition inside the substrate and macroscopic filtration performance and is recommended to be resolved in the filtration model to simulate and evaluate the filtration performance of GPFs.« less

Reverse osmosis followed by activated carbon filtration for efficient removal of organic micropollutants from river bank filtrate.

PubMed

Kegel, F Schoonenberg; Rietman, B M; Verliefde, A R D

2010-01-01

Drinking water utilities in Europe are faced with a growing presence of organic micropollutants in their water sources. The aim of this research was to assess the robustness of a drinking water treatment plant equipped with reverse osmosis and subsequent activated carbon filtration for the removal of these pollutants. The total removal efficiency of 47 organic micropollutants was investigated. Results indicated that removal of most organic micropollutants was high for all membranes tested. Some selected micropollutants were less efficiently removed (e.g. the small and polar NDMA and glyphosate, and the more hydrophobic ethylbenzene and napthalene). Very high removal efficiencies for almost all organic micropollutants by the subsequent activated carbon, fed with the permeate stream of the RO element were observed except for the very small and polar NDMA and 1,4-dioxane. RO and subsequent activated carbon filtration are complementary and their combined application results in the removal of a large part of these emerging organic micropollutants. Based on these experiments it can be concluded that the robustness of a proposed treatment scheme for the drinking water treatment plant Engelse Werk is sufficiently guaranteed.

Improvement of municipal wastewater pretreatment by direct membrane filtration.

PubMed

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.

Modeling filtration and fouling with a microstructured membrane filter

NASA Astrophysics Data System (ADS)

Cummings, Linda; Sanaei, Pejman

2017-11-01

Membrane filters find widespread use in diverse applications such as A/C systems and water purification. While the details of the filtration process may vary significantly, the broad challenge of efficient filtration is the same: to achieve finely-controlled separation at low power consumption. The obvious resolution to the challenge would appear simple: use the largest pore size consistent with the separation requirement. However, the membrane characteristics (and hence the filter performance) are far from constant over its lifetime: the particles removed from the feed are deposited within and on the membrane filter, fouling it and degrading the performance over time. The processes by which this occurs are complex, and depend on several factors, including: the internal structure of the membrane and the type of particles in the feed. We present a model for fouling of a simple microstructured membrane, and investigate how the details of the microstructure affect the filtration efficiency. Our idealized membrane consists of bifurcating pores, arranged in a layered structure, so that the number (and size) of pores changes in the depth of the membrane. In particular, we address how the details of the membrane microstructure affect the filter lifetime, and the total throughput. NSF DMS 1615719.

GPS Data Filtration Method for Drive Cycle Analysis Applications

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

Duran, A.; Earleywine, M.

2013-02-01

When employing GPS data acquisition systems to capture vehicle drive-cycle information, a number of errors often appear in the raw data samples, such as sudden signal loss, extraneous or outlying data points, speed drifting, and signal white noise, all of which limit the quality of field data for use in downstream applications. Unaddressed, these errors significantly impact the reliability of source data and limit the effectiveness of traditional drive-cycle analysis approaches and vehicle simulation software. Without reliable speed and time information, the validity of derived metrics for drive cycles, such as acceleration, power, and distance, become questionable. This study exploresmore » some of the common sources of error present in raw onboard GPS data and presents a detailed filtering process designed to correct for these issues. Test data from both light and medium/heavy duty applications are examined to illustrate the effectiveness of the proposed filtration process across the range of vehicle vocations. Graphical comparisons of raw and filtered cycles are presented, and statistical analyses are performed to determine the effects of the proposed filtration process on raw data. Finally, an evaluation of the overall benefits of data filtration on raw GPS data and present potential areas for continued research is presented.« less

Spectral quality requirements for effluent identification

NASA Astrophysics Data System (ADS)

Czerwinski, R. N.; Seeley, J. A.; Wack, E. C.

2005-11-01

We consider the problem of remotely identifying gaseous materials using passive sensing of long-wave infrared (LWIR) spectral features at hyperspectral resolution. Gaseous materials are distinguishable in the LWIR because of their unique spectral fingerprints. A sensor degraded in capability by noise or limited spectral resolution, however, may be unable to positively identify contaminants, especially if they are present in low concentrations or if the spectral library used for comparisons includes materials with similar spectral signatures. This paper will quantify the relative importance of these parameters and express the relationships between them in a functional form which can be used as a rule of thumb in sensor design or in assessing sensor capability for a specific task. This paper describes the simulation of remote sensing datacontaining a gas cloud.In each simulation, the spectra are degraded in spectral resolution and through the addition of noise to simulate spectra collected by sensors of varying design and capability. We form a trade space by systematically varying the number of sensor spectral channels and signal-to-noise ratio over a range of values. For each scenario, we evaluate the capability of the sensor for gas identification by computing the ratio of the F-statistic for the truth gas tothe same statistic computed over the rest of the library.The effect of the scope of the library is investigated as well, by computing statistics on the variability of the identification capability as the library composition is varied randomly.

Spectral methods to detect surface mines

NASA Astrophysics Data System (ADS)

Winter, Edwin M.; Schatten Silvious, Miranda

2008-04-01

Over the past five years, advances have been made in the spectral detection of surface mines under minefield detection programs at the U. S. Army RDECOM CERDEC Night Vision and Electronic Sensors Directorate (NVESD). The problem of detecting surface land mines ranges from the relatively simple, the detection of large anti-vehicle mines on bare soil, to the very difficult, the detection of anti-personnel mines in thick vegetation. While spatial and spectral approaches can be applied to the detection of surface mines, spatial-only detection requires many pixels-on-target such that the mine is actually imaged and shape-based features can be exploited. This method is unreliable in vegetated areas because only part of the mine may be exposed, while spectral detection is possible without the mine being resolved. At NVESD, hyperspectral and multi-spectral sensors throughout the reflection and thermal spectral regimes have been applied to the mine detection problem. Data has been collected on mines in forest and desert regions and algorithms have been developed both to detect the mines as anomalies and to detect the mines based on their spectral signature. In addition to the detection of individual mines, algorithms have been developed to exploit the similarities of mines in a minefield to improve their detection probability. In this paper, the types of spectral data collected over the past five years will be summarized along with the advances in algorithm development.

A CONTINUED INVESTIGATION OF ELECTRICALLY STIMULATED FABRIC FILTRATION

EPA Science Inventory

The report summarizes three experiments performed by Southern Research Institute under a cooperative agreement with EPA. First was a demonstration of electrostatically stimulated fabric filtration (ESFF) used to collect particulate matter (PM) from fossil fuel electrical power pl...

Clinical dehydration and glomerular filtration rate in acute paediatric gastroenteritis.

PubMed

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.

CONTRIBUTIONS OF WATER FILTRATION TO IMPROVING WATER QUALITY

EPA Science Inventory

A variety of water quality improvements can be accomplished by properly operated filtration plants. These include reduction of turbidity, micro-organisms, asbestos fibers, color, trihalomethane precursors, and organics adsorbed to particulate matter. The focus of the paper is on ...

Spectral-Spatial Scale Invariant Feature Transform for Hyperspectral Images.

PubMed

Al-Khafaji, Suhad Lateef; Jun Zhou; Zia, Ali; Liew, Alan Wee-Chung

2018-02-01

Spectral-spatial feature extraction is an important task in hyperspectral image processing. In this paper we propose a novel method to extract distinctive invariant features from hyperspectral images for registration of hyperspectral images with different spectral conditions. Spectral condition means images are captured with different incident lights, viewing angles, or using different hyperspectral cameras. In addition, spectral condition includes images of objects with the same shape but different materials. This method, which is named spectral-spatial scale invariant feature transform (SS-SIFT), explores both spectral and spatial dimensions simultaneously to extract spectral and geometric transformation invariant features. Similar to the classic SIFT algorithm, SS-SIFT consists of keypoint detection and descriptor construction steps. Keypoints are extracted from spectral-spatial scale space and are detected from extrema after 3D difference of Gaussian is applied to the data cube. Two descriptors are proposed for each keypoint by exploring the distribution of spectral-spatial gradient magnitude in its local 3D neighborhood. The effectiveness of the SS-SIFT approach is validated on images collected in different light conditions, different geometric projections, and using two hyperspectral cameras with different spectral wavelength ranges and resolutions. The experimental results show that our method generates robust invariant features for spectral-spatial image matching.

Copper Filtration and kVp: Effect on Entrance Skin Exposure.

PubMed

Barba, James; Culp, Melissa

2015-01-01

The selection of technical factors to produce an image is driven primarily by the patient, body part, and factors regarding the status of that patient or part. Analog receptor systems are restricted by the ranges of data they are able to record, as well as the quantity and quality of data required to record an image. Using digital receptors allows for a wider range of exposure factors because of the nature of the receptor systems and the data processing methods employed. Thus, factor selection can be more patient centered when using digital receptors to produce a radiograph. To explore the relationship between milliampere seconds (mAs), kilovoltage peak (kVp), and additional copper filtration with exposure indicators and entrance skin exposure (ESE) using both analog and digital receptors. Researchers conducted 2-tailed t-tests using Stata/IC version 11.2 software (StataCorp LP) to compare ESE from several trials using hip and knee phantoms. The analysis indicated that increasing kVp, adding 0.1 mm copper filtration, and correspondingly reducing mAs reduced ESE on a hip phantom by 64%, from 151 mR to 54.4 mR and reduced ESE on a knee phantom by 51%, from 27.2 mR to 13.4 mR. Radiology departments and radiologic technologists can consider these data when creating dose reduction protocols. The wider latitude range of digital radiography can be used to minimize patient exposure while still producing images of diagnostic quality within the acceptable exposure indicator range stated by the manufacturer.

Assessment of glomerular filtration rate and effective renal plasma flow in cystic fibrosis

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

Spino, M.; Chai, R.P.; Isles, A.F.

1985-07-01

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 /sup 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 resultmore » of enhanced glomerular filtration or tubular secretion.« less

Extending the Dynamic Range of the Ion Trap by Differential Mobility Filtration

PubMed Central

Hall, Adam B.; Coy, Stephen L.; Kafle, Amol; Glick, James; Nazarov, Erkinjon

2013-01-01

A miniature, planar, differential ion mobility spectrometer (DMS) was interfaced to an LCQ classic ion trap to conduct selective ion filtration prior to mass analysis in order to extend the dynamic range of the trap. Space charge effects are known to limit the functional ion storage capacity of ion trap mass analyzers and this, in turn, can affect the quality of the mass spectral data generated. This problem is further exacerbated in the analysis of mixtures where the indiscriminate introduction of matrix ions results in premature trap saturation with non-targeted species, thereby reducing the number of parent ions that may be used to conduct MS/MS experiments for quantitation or other diagnostic studies. We show that conducting differential mobility-based separations prior to mass analysis allows the isolation of targeted analytes from electrosprayed mixtures preventing the indiscriminate introduction of matrix ions and premature trap saturation with analytically unrelated species. Coupling these two analytical techniques is shown to enhance the detection of a targeted drug metabolite from a biological matrix. In its capacity as a selective ion filter, the DMS can improve the analytical performance of analyzers such as quadrupole (3-D or linear) and ion cyclotron resonance (FT-ICR) ion traps that depend on ion accumulation. PMID:23797861

Measurements of scene spectral radiance variability

NASA Astrophysics Data System (ADS)

Seeley, Juliette A.; Wack, Edward C.; Mooney, Daniel L.; Muldoon, Michael; Shey, Shen; Upham, Carolyn A.; Harvey, John M.; Czerwinski, Richard N.; Jordan, Michael P.; Vallières, Alexandre; Chamberland, Martin

2006-05-01

Detection performance of LWIR passive standoff chemical agent sensors is strongly influenced by various scene parameters, such as atmospheric conditions, temperature contrast, concentration-path length product (CL), agent absorption coefficient, and scene spectral variability. Although temperature contrast, CL, and agent absorption coefficient affect the detected signal in a predictable manner, fluctuations in background scene spectral radiance have less intuitive consequences. The spectral nature of the scene is not problematic in and of itself; instead it is spatial and temporal fluctuations in the scene spectral radiance that cannot be entirely corrected for with data processing. In addition, the consequence of such variability is a function of the spectral signature of the agent that is being detected and is thus different for each agent. To bracket the performance of background-limited (low sensor NEDN), passive standoff chemical sensors in the range of relevant conditions, assessment of real scene data is necessary1. Currently, such data is not widely available2. To begin to span the range of relevant scene conditions, we have acquired high fidelity scene spectral radiance measurements with a Telops FTIR imaging spectrometer 3. We have acquired data in a variety of indoor and outdoor locations at different times of day and year. Some locations include indoor office environments, airports, urban and suburban scenes, waterways, and forest. We report agent-dependent clutter measurements for three of these backgrounds.

THE EFFECTS OF COMBINED OZONATION AND FILTRATION ON DISINFECTION BY-PRODUCT FORMATION. (R830908)

EPA Science Inventory

The effects of combined ozonation and membrane filtration on the removal of the natural organic matter (NOM) and the formation of disinfection by-products (DBPs) were investigated. Ozonation/filtration resulted in a reduction of up to 50% in the dissolved organic carbon (DOC) ...

Preparation of hierarchical structured nano-sized/porous poly(lactic acid) composite fibrous membranes for air filtration

NASA Astrophysics Data System (ADS)

Wang, Zhe; Pan, Zhijuan

2015-11-01

Hierarchical structured nano-sized/porous poly(lactic acid) (PLA-N/PLA-P) composite fibrous membranes with excellent air filtration performance were prepared via an electrospinning technique. Firstly, PLA-P fibers with different morphology were fabricated by varying the relative humidity, and the nanopores on fiber surface played a key role in improving the specific surface area and filtration performance of the resultant membranes. Secondly, hierarchical structure of PLA-N/PLA-P interlaced structured membranes and PLA-N/PLA-P double-layer structured membranes with different mass ratios for further enhanced air filtration performance were also successfully prepared by combining PLA-N fibers with PLA-P fibers. Filtration tests by measuring the penetration of sodium chloride (NaCl) aerosol particles with a 260 nm mass median diameter revealed that a moderate mass ratio of PLA-P fibers and PLA-N fibers contributed to improving the filtration performance of the hierarchical structured PLA-N/PLA-P composite membrane, and the double-layer structured PLA-N/PLA-P membrane possessed a higher filtration efficiency and quality factor than that of an interlaced structured PLA-N/PLA-P membrane with the same mass ratio. The as-prepared PLA-N/PLA-P double-layer structured membrane with a mass ratio of 1/5 showed a high filtration efficiency (99.999%) and a relatively low pressure drop (93.3 Pa) at the face velocity of 5.3 cm/s.

Enhanced membrane filtration of wood hydrolysates for hemicelluloses recovery by pretreatment with polymeric adsorbents.

PubMed

Koivula, Elsi; Kallioinen, Mari; Sainio, Tuomo; Antón, Enrique; Luque, Susana; Mänttäri, Mika

2013-09-01

In this study adsorption of foulants from birch and pine/eucalyptus wood hydrolysates on two polymeric adsorbents was studied aiming to reduce the membrane fouling. The effect of the pretreatment of hydrolysate on polyethersulphone membrane performance was studied in dead-end filtration experiments. Adsorption pretreatment improved significantly filtration capacity and decreased membrane fouling. Especially high-molecular weight lignin was efficiently removed. A multistep adsorption pretreatment was found to reduce the amount of adsorbent required. While large adsorbent amount was shown to increase flux in filtration, it was found also to cause significant hemicellulose losses. Copyright © 2013 Elsevier Ltd. All rights reserved.

[Colorimetric characterization of LCD based on wavelength partition spectral model].

PubMed

Liu, Hao-Xue; Cui, Gui-Hua; Huang, Min; Wu, Bing; Xu, Yan-Fang; Luo, Ming

2013-10-01

To establish a colorimetrical characterization model of LCDs, an experiment with EIZO CG19, IBM 19, DELL 19 and HP 19 LCDs was designed and carried out to test the interaction between RGB channels, and then to test the spectral additive property of LCDs. The RGB digital values of single channel and two channels were given and the corresponding tristimulus values were measured, then a chart was plotted and calculations were made to test the independency of RGB channels. The results showed that the interaction between channels was reasonably weak and spectral additivity property was held well. We also found that the relations between radiations and digital values at different wavelengths varied, that is, they were the functions of wavelength. A new calculation method based on piecewise spectral model, in which the relation between radiations and digital values was fitted by a cubic polynomial in each piece of wavelength with measured spectral radiation curves, was proposed and tested. The spectral radiation curves of RGB primaries with any digital values can be found out with only a few measurements and fitted cubic polynomial in this way and then any displayed color can be turned out by the spectral additivity property of primaries at given digital values. The algorithm of this method was discussed in detail in this paper. The computations showed that the proposed method was simple and the number of measurements needed was reduced greatly while keeping a very high computation precision. This method can be used as a colorimetrical characterization model.

Spectral Reconstruction for Obtaining Virtual Hyperspectral Images

NASA Astrophysics Data System (ADS)

Perez, G. J. P.; Castro, E. C.

2016-12-01

Hyperspectral sensors demonstrated its capabalities in identifying materials and detecting processes in a satellite scene. However, availability of hyperspectral images are limited due to the high development cost of these sensors. Currently, most of the readily available data are from multi-spectral instruments. Spectral reconstruction is an alternative method to address the need for hyperspectral information. The spectral reconstruction technique has been shown to provide a quick and accurate detection of defects in an integrated circuit, recovers damaged parts of frescoes, and it also aids in converting a microscope into an imaging spectrometer. By using several spectral bands together with a spectral library, a spectrum acquired by a sensor can be expressed as a linear superposition of elementary signals. In this study, spectral reconstruction is used to estimate the spectra of different surfaces imaged by Landsat 8. Four atmospherically corrected surface reflectance from three visible bands (499 nm, 585 nm, 670 nm) and one near-infrared band (872 nm) of Landsat 8, and a spectral library of ground elements acquired from the United States Geological Survey (USGS) are used. The spectral library is limited to 420-1020 nm spectral range, and is interpolated at one nanometer resolution. Singular Value Decomposition (SVD) is used to calculate the basis spectra, which are then applied to reconstruct the spectrum. The spectral reconstruction is applied for test cases within the library consisting of vegetation communities. This technique was successful in reconstructing a hyperspectral signal with error of less than 12% for most of the test cases. Hence, this study demonstrated the potential of simulating information at any desired wavelength, creating a virtual hyperspectral sensor without the need for additional satellite bands.

Effect of filtration rates on hollow fiber ultrafilter concentration of viruses and protozoans from large volumes of water

EPA Science Inventory

Aims: To describe the ability of tangential flow hollow-fiber ultrafiltration to recover viruses from large volumes of water when run either at high filtration rates or lower filtration rates and recover Cryptosporidium parvum at high filtration rates. Methods and Results: Wate...

Feasibility of bioengineered two-stages sequential batch reactor and filtration-adsorption process for complex agrochemical effluent.

PubMed

Manekar, Pravin; Biswas, Rima; Urewar, Chaitali; Pal, Sukdeb; Nandy, Tapas

2013-11-01

In the present study, the feasibility of a bioengineered two-stages sequential batch reactor (BTSSBR) followed by filtration-adsorption process was investigated to treat the agrochemical effluent by overcoming factor affecting process stability such as microbial imbalance and substrate sensitivity. An air stripper stripped 90% of toxic ammonia, and combined with other streams for bio-oxidation and filtration-adsorption. The BTSSBR system achieved bio-oxidation at 6 days hydraulic retention time by fending off microbial imbalance and substrate sensitivity. The maximum reduction in COD and BOD by heterotrophic bacteria in the first reactor was 87% and 90%, respectively. Removal of toxic ammoniacal-nitrogen by autotrophic bacteria in a post-second stage bio-oxidation was 97%. The optimum filtration and adsorption of pollutants were achieved at a filtration rate of 10 and 9 m(3)m(-2)h(-1), respectively. The treatment scheme comprising air stripper, BTSSBR and filtration-adsorption process showed a great promise for treating the agrochemical effluent. Copyright © 2013 Elsevier Ltd. All rights reserved.

Transport of micropollutants in a riverbank filtration system

NASA Astrophysics Data System (ADS)

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

RIVERBANK FILTRATION AS A PRETREATMENT FOR NANOFILTRATION MEMBRANES

EPA Science Inventory

The loss of membrane efficiency due to fouling is one of the main impediments to the development of membrane processes for use in drinking water treatment. Surface waters, in general, have a greater proclivity towards fouling as compared to groundwaters. Riverbank filtration ch...

40 CFR 141.171 - Criteria for avoiding filtration.

Code of Federal Regulations, 2010 CFR

2010-07-01

....171 Section 141.171 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) WATER PROGRAMS (CONTINUED) NATIONAL PRIMARY DRINKING WATER REGULATIONS Enhanced Filtration and Disinfection... requirements of § 141.71, a public water system subject to the requirements of this subpart that does not...

RIVERBANK FILTRATION AS A PRETREATMENT FOR NANOFILTRATION MEMBRANES

EPA Science Inventory

The loss of membrane efficiency due to fouling is one of the main impediments to the development of membrane processes for use in drinking water treatment. Surface waters, in general, have a greater proclivity towards fouling as compared to groundwaters. Riverbank filtration chan...

Influence of Surface Properties of Filtration-Layer Metal Oxide on Ceramic Membrane Fouling during Ultrafiltration of Oil/Water Emulsion.

PubMed

Lu, Dongwei; Zhang, Tao; Gutierrez, Leo; Ma, Jun; Croué, Jean-Philippe

2016-05-03

In this work, ceramic ultrafiltration membranes deposited with different metal oxides (i.e., TiO2, Fe2O3, MnO2, CuO, and CeO2) of around 10 nm in thickness and similar roughness were tested for O/W emulsion treatment. A distinct membrane fouling tendency was observed, which closely correlated to the properties of the filtration-layer metal oxides (i.e., surface hydroxyl groups, hydrophilicity, surface charge, and adhesion energy for oil droplets). Consistent with the distinct bond strength of the surface hydroxyl groups, hydrophilicity of these common metal oxides is quite different. The differences in hydrophilicity consequently lead to different adhesion of these metal oxides toward oil droplets, consistent with the irreversible membrane fouling tendency. In addition, the surface charge of the metal oxide opposite to that of emulsion can help to alleviate irreversible membrane fouling in ultrafiltration. Highly hydrophilic Fe2O3 with the lowest fouling tendency could be a potential filtration-layer material for the fabrication/modification of ceramic membranes for O/W emulsion treatment. To the best of our knowledge, this is the first study clearly showing the correlations between surface properties of filtration-layer metal oxides and ceramic membrane fouling tendency by O/W emulsion.

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

PubMed

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.

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

PubMed

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.

FILTRATION OF GROUND WATER SAMPLES FOR METALS ANALYSIS

EPA Science Inventory

The filtration of a ground water samples with 0.45 um filters for determination of 'dissolved' metals is not only inaccurate for distinguishing between dissolved and particulate phases, but if used for estimates of mobile contaminant loading in a given aquifer, may result in sign...

Fast filtration sampling protocol for mammalian suspension cells tailored for phosphometabolome profiling by capillary ion chromatography - tandem mass spectrometry.

PubMed

Kvitvang, Hans F N; Bruheim, Per

2015-08-15

Capillary ion chromatography (capIC) is the premium separation technology for low molecular phosphometabolites and nucleotides in biological extracts. Removal of excessive amounts of salt during sample preparation stages is a prerequisite to enable high quality capIC separation in combination with reproducible and sensitive MS detection. Existing sampling protocols for mammalian cells used for GC-MS and LC-MS metabolic profiling can therefore not be directly applied to capIC separations. Here, the development of a fast filtration sampling protocol for mammalian suspension cells tailored for quantitative profiling of the phosphometabolome on capIC-MS/MS is presented. The whole procedure from sampling the culture to transfer of filter to quenching and extraction solution takes less than 10s. To prevent leakage it is critical that a low vacuum pressure is applied, and satisfactorily reproducibility was only obtained by usage of a vacuum pressure controlling device. A vacuum of 60mbar was optimal for filtration of multiple myeloma Jjn-3 cell cultures through 5μm polyvinylidene (PVDF) filters. A quick deionized water (DI-water) rinse step prior to extraction was tested, and significantly higher metabolite yields were obtained during capIC-MS/MS analyses in this extract compared to extracts prepared by saline and reduced saline (25%) washing steps only. In addition, chromatographic performance was dramatically improved. Thus, it was verified that a quick DI-water rinse is tolerated by the cells and can be included as the final stage during filtration. Over 30 metabolites were quantitated in JJN-3 cell extracts by using the optimized sampling protocol with subsequent capIC-MS/MS analysis, and up to 2 million cells can be used in a single filtration step for the chosen filter and vacuum pressure. The technical set-up is also highly advantageous for microbial metabolome filtration protocols after optimization of vacuum pressure and washing solutions, and the reduced salt

Effect of Fusarium isolates and their filtrates on respiratory rate and chemical analysis of squash plants.

PubMed

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.

Problems associated with using filtration to define dissolved trace element concentrations in natural water samples

USGS Publications Warehouse

Horowitz, A.J.; Lum, K.R.; Garbarino, J.R.; Hall, G.E.M.; Lemieux, C.; Demas, C.R.

1996-01-01

Field and laboratory experiments indicate that a number of factors associated with filtration other than just pore size (e.g., diameter, manufacturer, volume of sample processed, amount of suspended sediment in the sample) can produce significant variations in the 'dissolved' concentrations of such elements as Fe, Al, Cu, Zn, Pb, Co, and Ni. The bulk of these variations result from the inclusion/exclusion of colloidally associated trace elements in the filtrate, although dilution and sorption/desorption from filters also may be factors. Thus, dissolved trace element concentrations quantitated by analyzing filtrates generated by processing whole water through similar pore-sized filters may not be equal or comparable. As such, simple filtration of unspecified volumes of natural water through unspecified 0.45-??m membrane filters may no longer represent an acceptable operational definition for a number of dissolved chemical constituents.

Podocyte Glutamatergic Signaling Contributes to the Function of the Glomerular Filtration Barrier

PubMed Central

Giardino, Laura; Armelloni, Silvia; Corbelli, Alessandro; Mattinzoli, Deborah; Zennaro, Cristina; Guerrot, Dominique; Tourrel, Fabien; Ikehata, Masami; Li, Min; Berra, Silvia; Carraro, Michele; Messa, Piergiorgio

2009-01-01

Podocytes possess the complete machinery for glutamatergic signaling, raising the possibility that neuron-like signaling contributes to glomerular function. To test this, we studied mice and cells lacking Rab3A, a small GTPase that regulates glutamate exocytosis. In addition, we blocked the glutamate ionotropic N-methyl-d-aspartate receptor (NMDAR) with specific antagonists. In mice, the absence of Rab3A and blockade of NMDAR both associated with an increased urinary albumin/creatinine ratio. In humans, NMDAR blockade, obtained by addition of ketamine to general anesthesia, also had an albuminuric effect. In vitro, Rab3A-null podocytes displayed a dysregulated release of glutamate with higher rates of spontaneous exocytosis, explained by a reduction in Rab3A effectors resulting in freedom of vesicles from the actin cytoskeleton. In addition, NMDAR antagonism led to profound cytoskeletal remodeling and redistribution of nephrin in cultured podocytes; the addition of the agonist NMDA reversed these changes. In summary, these results suggest that glutamatergic signaling driven by podocytes contributes to the integrity of the glomerular filtration barrier and that derangements in this signaling may lead to proteinuric renal diseases. PMID:19578006

Speech identification in noise: Contribution of temporal, spectral, and visual speech cues.

PubMed

Kim, Jeesun; Davis, Chris; Groot, Christopher

2009-12-01

This study investigated the degree to which two types of reduced auditory signals (cochlear implant simulations) and visual speech cues combined for speech identification. The auditory speech stimuli were filtered to have only amplitude envelope cues or both amplitude envelope and spectral cues and were presented with/without visual speech. In Experiment 1, IEEE sentences were presented in quiet and noise. For in-quiet presentation, speech identification was enhanced by the addition of both spectral and visual speech cues. Due to a ceiling effect, the degree to which these effects combined could not be determined. In noise, these facilitation effects were more marked and were additive. Experiment 2 examined consonant and vowel identification in the context of CVC or VCV syllables presented in noise. For consonants, both spectral and visual speech cues facilitated identification and these effects were additive. For vowels, the effect of combined cues was underadditive, with the effect of spectral cues reduced when presented with visual speech cues. Analysis indicated that without visual speech, spectral cues facilitated the transmission of place information and vowel height, whereas with visual speech, they facilitated lip rounding, with little impact on the transmission of place information.

Importance of filter’s microstructure in dynamic filtration modeling of gasoline particulate filters (GPFs): Inhomogeneous porosity and pore size distribution

DOE PAGES

Gong, Jian; Stewart, Mark L.; Zelenyuk, Alla; ...

2018-01-03

The state-of-the-art multiscale modeling of gasoline particulate filter (GPF) including channel scale, wall scale, and pore scale is described. The microstructures of two GPFs were experimentally characterized. The pore size distributions of the GPFs were determined by mercury porosimetry. The porosity was measured by X-ray computed tomography (CT) and found to be inhomogeneous across the substrate wall. The significance of pore size distribution with respect to filtration performance was analyzed. The predictions of filtration efficiency were improved by including the pore size distribution in the filtration model. A dynamic heterogeneous multiscale filtration (HMF) model was utilized to simulate particulate filtrationmore » on a single channel particulate filter with realistic particulate emissions from a spark-ignition direct-injection (SIDI) gasoline engine. The dynamic evolution of filter’s microstructure and macroscopic filtration characteristics including mass- and number-based filtration efficiencies and pressure drop were predicted and discussed. In conclusion, the microstructure of the GPF substrate including inhomogeneous porosity and pore size distribution is found to significantly influence local particulate deposition inside the substrate and macroscopic filtration performance and is recommended to be resolved in the filtration model to simulate and evaluate the filtration performance of GPFs.« less

Importance of filter’s microstructure in dynamic filtration modeling of gasoline particulate filters (GPFs): Inhomogeneous porosity and pore size distribution

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

Gong, Jian; Stewart, Mark L.; Zelenyuk, Alla

The state-of-the-art multiscale modeling of gasoline particulate filter (GPF) including channel scale, wall scale, and pore scale is described. The microstructures of two GPFs were experimentally characterized. The pore size distributions of the GPFs were determined by mercury porosimetry. The porosity was measured by X-ray computed tomography (CT) and found to be inhomogeneous across the substrate wall. The significance of pore size distribution with respect to filtration performance was analyzed. The predictions of filtration efficiency were improved by including the pore size distribution in the filtration model. A dynamic heterogeneous multiscale filtration (HMF) model was utilized to simulate particulate filtrationmore » on a single channel particulate filter with realistic particulate emissions from a spark-ignition direct-injection (SIDI) gasoline engine. The dynamic evolution of filter’s microstructure and macroscopic filtration characteristics including mass- and number-based filtration efficiencies and pressure drop were predicted and discussed. In conclusion, the microstructure of the GPF substrate including inhomogeneous porosity and pore size distribution is found to significantly influence local particulate deposition inside the substrate and macroscopic filtration performance and is recommended to be resolved in the filtration model to simulate and evaluate the filtration performance of GPFs.« less

Further evaluation of alternative air-filtration systems for reducing the transmission of Porcine reproductive and respiratory syndrome virus by aerosol

PubMed Central

Deen, John; Cano, Jean Paul; Batista, Laura; Pijoan, Carlos

2006-01-01

Abstract The purpose of this study was to compare 4 methods for the reduction of aerosol transmission of Porcine reproductive and respiratory syndrome virus (PRRSV): high-efficiency particulate air (HEPA) filtration, 2×-low-cost filtration, bag filtration, and use of a filter tested against particles derived from dioctylphthalate (DOP). The HEPA-filtration system used a prefilter screen, a bag filter (Eurovent [EU] 8 rating), and a HEPA filter (EU13 rating). The low-cost-filtration system contained mosquito netting (prefilter), 2 fiberglass furnace filters, and 2 electrostatic furnace filters. Bag filtration involved the use of a filter rated EU8 and a minimum efficiency reporting value (MERV) of 14. The 95%-DOP, 0.3-μm-filtration system involved a pleat-in-pleat V-bank disposable filter with a 95% efficiency rating for particles 0.3 μm or greater in diameter and ratings of EU9 and MERV 15. No form of intervention was used in the control group. The experimental facilities consisted of 2 chambers connected by a 1.3-m-long duct containing the treatments. Recipient pigs, housed in chamber 2, were exposed to artificial aerosols created by a mechanically operated mister containing modified live PRRSV vaccine located in chamber 1. Aerosol transmission of PRRSV occurred in 0 of the 10 HEPA-filtration replicates, 2 of the 10 bag-filtration replicates, 4 of the 10 low-cost-filtration replicates, 0 of the 10 95%-DOP, 0.3-μm-filtration replicates, and all 10 of the control replicates. Using a similar approach, we further evaluated the HEPA- and 95%-DOP, 0.3-μm-filtration systems. Infection was not observed in any of the 76 HEPA-filtration replicates but was observed in 2 of the 76 95%-DOP, 0.3-μm replicates and 42 of the 50 control replicates. Although the difference between the 95%-DOP, 0.3-μm and control replicates was significant (P < 0.0005), so was the level of failure of the 95%-DOP, 0.3-μm system (P = 0.02). In conclusion, under the conditions of this study

40 CFR 141.71 - Criteria for avoiding filtration.

Code of Federal Regulations, 2011 CFR

2011-07-01

... PROGRAMS (CONTINUED) NATIONAL PRIMARY DRINKING WATER REGULATIONS Filtration and Disinfection § 141.71... water. (2) The public water system must maintain a watershed control program which minimizes the... determine whether the watershed control program is adequate to meet this goal. The adequacy of a program to...

NASA Lunar Dust Filtration and Separations Workshop Report

NASA Technical Reports Server (NTRS)

Agui, Juan H.; Stocker, Dennis P.

2009-01-01

NASA Glenn Research Center hosted a 2.5-day workshop, entitled "NASA Lunar Dust Filtration and Separations Workshop" at the Ohio Aerospace Institute in Cleveland, Ohio, on November 18 to 20, 2008. The purpose of the workshop was to address the issues and challenges of particulate matter removal from the cabin atmospheres in the Altair lunar lander, lunar habitats, and in pressurized rovers. The presence of lunar regolith dust inside the pressurized volumes was a theme of particular interest. The workshop provided an opportunity for NASA, industry experts, and academia to identify and discuss the capabilities of current and developing air and gas particulate matter filtration and separations technologies as they may apply to NASA s needs. A goal of the workshop was to provide recommendations for strategic research areas in cabin atmospheric particulate matter removal and disposal technologies that will advance and/or supplement the baseline approach for these future lunar surface exploration missions.

Rayleigh imaging in spectral mammography

NASA Astrophysics Data System (ADS)

Berggren, Karl; Danielsson, Mats; Fredenberg, Erik

2016-03-01

Spectral imaging is the acquisition of multiple images of an object at different energy spectra. In mammography, dual-energy imaging (spectral imaging with two energy levels) has been investigated for several applications, in particular material decomposition, which allows for quantitative analysis of breast composition and quantitative contrast-enhanced imaging. Material decomposition with dual-energy imaging is based on the assumption that there are two dominant photon interaction effects that determine linear attenuation: the photoelectric effect and Compton scattering. This assumption limits the number of basis materials, i.e. the number of materials that are possible to differentiate between, to two. However, Rayleigh scattering may account for more than 10% of the linear attenuation in the mammography energy range. In this work, we show that a modified version of a scanning multi-slit spectral photon-counting mammography system is able to acquire three images at different spectra and can be used for triple-energy imaging. We further show that triple-energy imaging in combination with the efficient scatter rejection of the system enables measurement of Rayleigh scattering, which adds an additional energy dependency to the linear attenuation and enables material decomposition with three basis materials. Three available basis materials have the potential to improve virtually all applications of spectral imaging.

Spectral Anonymization of Data

PubMed Central

Lasko, Thomas A.; Vinterbo, Staal A.

2011-01-01

The goal of data anonymization is to allow the release of scientifically useful data in a form that protects the privacy of its subjects. This requires more than simply removing personal identifiers from the data, because an attacker can still use auxiliary information to infer sensitive individual information. Additional perturbation is necessary to prevent these inferences, and the challenge is to perturb the data in a way that preserves its analytic utility. No existing anonymization algorithm provides both perfect privacy protection and perfect analytic utility. We make the new observation that anonymization algorithms are not required to operate in the original vector-space basis of the data, and many algorithms can be improved by operating in a judiciously chosen alternate basis. A spectral basis derived from the data’s eigenvectors is one that can provide substantial improvement. We introduce the term spectral anonymization to refer to an algorithm that uses a spectral basis for anonymization, and we give two illustrative examples. We also propose new measures of privacy protection that are more general and more informative than existing measures, and a principled reference standard with which to define adequate privacy protection. PMID:21373375

Automated spectral classification and the GAIA project

NASA Technical Reports Server (NTRS)

Lasala, Jerry; Kurtz, Michael J.

1995-01-01

Two dimensional spectral types for each of the stars observed in the global astrometric interferometer for astrophysics (GAIA) mission would provide additional information for the galactic structure and stellar evolution studies, as well as helping in the identification of unusual objects and populations. The classification of the large quantity generated spectra requires that automated techniques are implemented. Approaches for the automatic classification are reviewed, and a metric-distance method is discussed. In tests, the metric-distance method produced spectral types with mean errors comparable to those of human classifiers working at similar resolution. Data and equipment requirements for an automated classification survey, are discussed. A program of auxiliary observations is proposed to yield spectral types and radial velocities for the GAIA-observed stars.

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

PubMed

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.

40 CFR 141.71 - Criteria for avoiding filtration.

Code of Federal Regulations, 2010 CFR

2010-07-01

... PROGRAMS (CONTINUED) NATIONAL PRIMARY DRINKING WATER REGULATIONS Filtration and Disinfection § 141.71... developed under section 1428 of the Safe Drinking Water Act may be used, if the State deems it appropriate... representative sample of the source water immediately prior to the first or only point of disinfection...

Partial liquid ventilation reduces fluid filtration of isolated rabbit lungs with acute hydrochloric acid-induced edema.

PubMed

Loer, S A; Tarnow, J

2001-06-01

Hydrochloric acid aspiration increases pulmonary microvascular permeability. The authors tested the hypothesis that partial liquid ventilation has a beneficial effect on filtration coefficients in acute acid-induced lung injury. Isolated blood-perfused rabbit lungs were assigned randomly to one of four groups. Group 1 (n = 6) served as a control group without edema. In group 2 (n = 6), group 3 (n = 6), and group 4 (n = 6), pulmonary edema was induced by intratracheal instillation of hydrochloric acid (0.1 N, 2 ml/kg body weight). Filtration coefficients were determined 30 min after this injury (by measuring loss of perfusate after increase of left atrial pressure). Group 2 lungs were gas ventilated, and group 3 lungs received partial liquid ventilation (15 ml perfluorocarbon/kg body weight). In group 4 lungs, the authors studied the immediate effects of bronchial perfluorocarbon instillation on ongoing filtration. Intratracheal instillation of hydrochloric acid markedly increased filtration coefficients when compared with non-injured control lungs (2.3 +/- 0.7 vs. 0.31 +/- 0.08 ml.min(-1). mmHg(-1).100 g(-1) wet lung weight, P < 0.01). Partial liquid ventilation reduced filtration coefficients of the injured lungs (to 0.9 +/- 0.3 ml.min(-1).mmHg(-1).100 g(-1) wet lung weight, P = 0.022). Neither pulmonary artery nor capillary pressures (determined by simultaneous occlusion of inflow and outflow of the pulmonary circulation) were changed by hydrochloric acid instillation or by partial liquid ventilation. During ongoing filtration, bronchial perfluorocarbon instillation (5 ml/kg body weight) immediately reduced the amount of filtered fluid by approximately 50% (P = 0.027). In the acute phase after acid injury, partial liquid ventilation reduced pathologic fluid filtration. This effect started immediately after bronchial perfluorocarbon instillation and was not associated with changes in mean pulmonary artery, capillary, or airway pressures. The authors suggest that

Removal of waterborne microorganisms by filtration using clay-polymer complexes.

PubMed

Undabeytia, Tomas; Posada, Rosa; Nir, Shlomo; Galindo, Irene; Laiz, Leonila; Saiz-Jimenez, Cesareo; Morillo, Esmeralda

2014-08-30

Clay-polymer composites were designed for use in filtration processes for disinfection during the course of water purification. The composites were formed by sorption of polymers based on starch modified with quaternary ammonium ethers onto the negatively charged clay mineral bentonite. The performance of the clay-polymer complexes in removal of bacteria was strongly dependent on the conformation adopted by the polycation on the clay surface, the charge density of the polycation itself and the ratio between the concentrations of clay and polymer used during the sorption process. The antimicrobial effect exerted by the clay-polymer system was due to the cationic monomers adsorbed on the clay surface, which resulted in a positive surface potential of the complexes and charge reversal. Clay-polymer complexes were more toxic to bacteria than the polymers alone. Filtration employing our optimal clay-polymer composite yielded 100% removal of bacteria after the passage of 3L, whereas an equivalent filter with granular activated carbon (GAC) hardly yielded removal of bacteria after 0.5L. Regeneration of clay-polymer complexes saturated with bacteria was demonstrated. Modeling of the filtration processes permitted to optimize the design of filters and estimation of experimental conditions for purifying large water volumes in short periods. Copyright © 2014 Elsevier B.V. All rights reserved.

Water filtration using plant xylem.

PubMed

Boutilier, Michael S H; Lee, Jongho; Chambers, Valerie; Venkatesh, Varsha; Karnik, Rohit

2014-01-01

Effective point-of-use devices for providing safe drinking water are urgently needed to reduce the global burden of waterborne disease. Here we show that plant xylem from the sapwood of coniferous trees--a readily available, inexpensive, biodegradable, and disposable material--can remove bacteria from water by simple pressure-driven filtration. Approximately 3 cm(3) of sapwood can filter water at the rate of several liters per day, sufficient to meet the clean drinking water needs of one person. The results demonstrate the potential of plant xylem to address the need for pathogen-free drinking water in developing countries and resource-limited settings.

Dewaterability of five sewage sludges in Guangzhou conditioned with Fenton's reagent/lime and pilot-scale experiments using ultrahigh pressure filtration system.

PubMed

Liang, Jialin; Huang, Shaosong; Dai, Yongkang; Li, Lei; Sun, Shuiyu

2015-11-01

Sludge conditioning with Fenton's reagent and lime is a valid method for sludge dewatering. This study investigated the influence of different organic matter content sludge on sludge dewatering and discussed the main mechanism of sludge conditioning by combined Fenton's reagent and lime. The results indicated that the specific resistance to filterability (SRF) of sludge was reduced efficiently by approximately 90%, when conditioned with Fenton's reagent and lime. Through single factor experiments, the optimal conditioning combinations were found. In addition, the relationship between VSS% and consumption of the reagents was detected. Furthermore, it was also demonstrated that the SRF and filtrate TOC values had a significant correlation with VSS% of sludge (including raw and conditioned). The main mechanism of sludge dewatering was also investigated. Firstly, it revealed that the dewaterability of sludge was closely correlated to extracellular polymeric substances (EPS) and bound water contents. Secondly, the results of scanning electron microscopy (SEM) stated that sludge particles were to be smaller and thinner after conditioning. And this structure could easily form outflow channels for releasing free water. Additionally, with the ultrahigh pressure filtration system, the water content of sludge cake conditioned with Fenton's reagent and lime could be reduced to below 50%. Moreover, the economic assessment shows that Fenton's reagent and lime combined with ultrahigh pressure filtration system can be an economical and viable technology for sewage sludge dewatering. Finally, three types of sludge were classified: (1) Fast to dewater; (2) Moderately fast to dewater; (3) Slow to dewater sludge. Copyright © 2015 Elsevier Ltd. All rights reserved.

Replacement of maize by rumen filtrate fermented corn-cob in layer diets.

PubMed

Adeyemi, O A; Familade, F O

2003-11-01

Laying hens (50 weeks in-lay) were fed for 8 weeks on diets containing corn-cobs fermented with rumen filtrate. The fermented corn-cob was included in the diets at 0%, 5.0%, 10.0%, 15.0% and 20.0% of the total diet at the expense of maize. Feed intake was not significantly (P>0.05) different, although birds on the control diet consumed slightly more feed than birds on the fermented corn-cob based diets. Hen day production and feed per dozen eggs decreased with increase in dietary level of corn-cob (P<0.05). Yolk colour was significantly (P<0.05) affected, rumen filtrate fermented corn-cob appear to promote better yolk coloration. Egg weight and shell thickness were not significantly influenced by dietary treatment. The overall results appear to suggest that rumen filtrate fermentated corn-cob could provide a material that holds promise as a good alternative to maize because of its enhanced crude protein value and reduced crude fibre content.

Effects of Ultra-Clean and centrifugal filtration on rolling-element bearing life

NASA Technical Reports Server (NTRS)

Loewenthal, S. H.; Moyer, D. W.; Needelman, W. M.

1981-01-01

Fatigue tests were conducted on groups of 65-millimeter bore diameter deep-groove ball bearings in a MIL-L-23699 lubricant under two levels of filtration. In one test series, the oil cleanliness was maintained at an exceptionally high level (better than a class "000" per NAS 1638) with a 3 micron absolute barrier filter. These tests were intended to determine the "upper limit" in bearing life under the strictest possible lubricant cleanliness conditions. In the tests using a centrifugal oil filter, contaminants of the type found in aircraft engine filters were injected into the filters' supply line at 125 milligrams per bearing-hour. "Ultra-clean" lubrication produced bearing fatigue lives that were approximately twice that obtained in previous tests with contaminated oil using 3 micron absolute filtration and approximately three times that obtained with 49 micron filtration. It was also observed that the centrifugal oil filter had approximately the same effectiveness as a 30 micron absolute filter in preventing bearing surface damage.

Extending color primary set in spectral vector error diffusion by multilevel halftoning

NASA Astrophysics Data System (ADS)

Norberg, Ole; Nyström, Daniel

2013-02-01

Ever since its origin in the late 19th century, a color reproduction technology has relied on a trichromatic color reproduction approach. This has been a very successful method and also fundamental for the development of color reproduction devices. Trichromatic color reproduction is sufficient to approximate the range of colors perceived by the human visual system. However, tricromatic systems only have the ability to match colors when the viewing illumination for the reproduction matches that of the original. Furthermore, the advancement of digital printing technology has introduced printing systems with additional color channels. These additional color channels are used to extend the tonal range capabilities in light and dark regions and to increase color gamut. By an alternative approach the addition color channels can also be used to reproduce the spectral information of the original color. A reproduced spectral match will always correspond to original independent of lighting situation. On the other hand, spectral color reproductions also introduce a more complex color processing by spectral color transfer functions and spectral gamut mapping algorithms. In that perspective, spectral vector error diffusion (sVED) look like a tempting approach with a simple workflow where the inverse color transfer function and halftoning is performed simultaneously in one single operation. Essential for the sVED method are the available color primaries, created by mixing process colors. Increased numbers of as well as optimal spectral characteristics of color primaries are expected to significantly improve the color accuracy of the spectral reproduction. In this study, sVED in combination with multilevel halftoning has been applied on a ten channel inkjet system. The print resolution has been reduced and the underlying physical high resolution of the printer has been used to mix additional primaries. With ten ink channels and halfton cells built-up by 2x2 micro dots where each

Biologically-inspired data decorrelation for hyper-spectral imaging

NASA Astrophysics Data System (ADS)

Picon, Artzai; Ghita, Ovidiu; Rodriguez-Vaamonde, Sergio; Iriondo, Pedro Ma; Whelan, Paul F.

2011-12-01

Hyper-spectral data allows the construction of more robust statistical models to sample the material properties than the standard tri-chromatic color representation. However, because of the large dimensionality and complexity of the hyper-spectral data, the extraction of robust features (image descriptors) is not a trivial issue. Thus, to facilitate efficient feature extraction, decorrelation techniques are commonly applied to reduce the dimensionality of the hyper-spectral data with the aim of generating compact and highly discriminative image descriptors. Current methodologies for data decorrelation such as principal component analysis (PCA), linear discriminant analysis (LDA), wavelet decomposition (WD), or band selection methods require complex and subjective training procedures and in addition the compressed spectral information is not directly related to the physical (spectral) characteristics associated with the analyzed materials. The major objective of this article is to introduce and evaluate a new data decorrelation methodology using an approach that closely emulates the human vision. The proposed data decorrelation scheme has been employed to optimally minimize the amount of redundant information contained in the highly correlated hyper-spectral bands and has been comprehensively evaluated in the context of non-ferrous material classification

Silica incorporated membrane for wastewater based filtration

NASA Astrophysics Data System (ADS)

Fernandes, C. S.; Bilad, M. R.; Nordin, N. A. H. M.

2017-10-01

Membrane technology has long been applied for waste water treatment industries due to its numerous advantages compared to other conventional processes. However, the biggest challenge in pressure driven membrane process is membrane fouling. Fouling decreases the productivity and efficiency of the filtration, reduces the lifespan of the membrane and reduces the overall efficiency of water treatment processes. In this study, a novel membrane material is developed for water filtration. The developed membrane incorporates silica nanoparticles mainly to improve its structural properties. Membranes with different loadings of silica nanoparticles were applied in this study. The result shows an increase in clean water permeability and filterability of the membrane for treating activated sludge, microalgae solution, secondary effluent and raw sewage as feed. Adding silica into the membrane matrix does not significantly alter contact angle and membrane pore size. We believe that silica acts as an effective pore forming agent that increases the number of pores without significantly altering the pore sizes. A higher number of small pores on the surface of the membrane could reduce membrane fouling because of a low specific loading imposed to individual pores.

Improvement of LOD in Fluorescence Detection with Spectrally Nonuniform Background by Optimization of Emission Filtering.

PubMed

Galievsky, Victor A; Stasheuski, Alexander S; Krylov, Sergey N

2017-10-17

The limit-of-detection (LOD) in analytical instruments with fluorescence detection can be improved by reducing noise of optical background. Efficiently reducing optical background noise in systems with spectrally nonuniform background requires complex optimization of an emission filter-the main element of spectral filtration. Here, we introduce a filter-optimization method, which utilizes an expression for the signal-to-noise ratio (SNR) as a function of (i) all noise components (dark, shot, and flicker), (ii) emission spectrum of the analyte, (iii) emission spectrum of the optical background, and (iv) transmittance spectrum of the emission filter. In essence, the noise components and the emission spectra are determined experimentally and substituted into the expression. This leaves a single variable-the transmittance spectrum of the filter-which is optimized numerically by maximizing SNR. Maximizing SNR provides an accurate way of filter optimization, while a previously used approach based on maximizing a signal-to-background ratio (SBR) is the approximation that can lead to much poorer LOD specifically in detection of fluorescently labeled biomolecules. The proposed filter-optimization method will be an indispensable tool for developing new and improving existing fluorescence-detection systems aiming at ultimately low LOD.

SPAM- SPECTRAL ANALYSIS MANAGER (UNIX VERSION)

NASA Technical Reports Server (NTRS)

Solomon, J. E.

1994-01-01

The Spectral Analysis Manager (SPAM) was developed to allow easy qualitative analysis of multi-dimensional imaging spectrometer data. Imaging spectrometers provide sufficient spectral sampling to define unique spectral signatures on a per pixel basis. Thus direct material identification becomes possible for geologic studies. SPAM provides a variety of capabilities for carrying out interactive analysis of the massive and complex datasets associated with multispectral remote sensing observations. In addition to normal image processing functions, SPAM provides multiple levels of on-line help, a flexible command interpretation, graceful error recovery, and a program structure which can be implemented in a variety of environments. SPAM was designed to be visually oriented and user friendly with the liberal employment of graphics for rapid and efficient exploratory analysis of imaging spectrometry data. SPAM provides functions to enable arithmetic manipulations of the data, such as normalization, linear mixing, band ratio discrimination, and low-pass filtering. SPAM can be used to examine the spectra of an individual pixel or the average spectra over a number of pixels. SPAM also supports image segmentation, fast spectral signature matching, spectral library usage, mixture analysis, and feature extraction. High speed spectral signature matching is performed by using a binary spectral encoding algorithm to separate and identify mineral components present in the scene. The same binary encoding allows automatic spectral clustering. Spectral data may be entered from a digitizing tablet, stored in a user library, compared to the master library containing mineral standards, and then displayed as a timesequence spectral movie. The output plots, histograms, and stretched histograms produced by SPAM can be sent to a lineprinter, stored as separate RGB disk files, or sent to a Quick Color Recorder. SPAM is written in C for interactive execution and is available for two different

A spectral mimetic least-squares method

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

Bochev, Pavel; Gerritsma, Marc

We present a spectral mimetic least-squares method for a model diffusion–reaction problem, which preserves key conservation properties of the continuum problem. Casting the model problem into a first-order system for two scalar and two vector variables shifts material properties from the differential equations to a pair of constitutive relations. We also use this system to motivate a new least-squares functional involving all four fields and show that its minimizer satisfies the differential equations exactly. Discretization of the four-field least-squares functional by spectral spaces compatible with the differential operators leads to a least-squares method in which the differential equations are alsomore » satisfied exactly. Additionally, the latter are reduced to purely topological relationships for the degrees of freedom that can be satisfied without reference to basis functions. Furthermore, numerical experiments confirm the spectral accuracy of the method and its local conservation.« less

A spectral mimetic least-squares method

DOE PAGES

Bochev, Pavel; Gerritsma, Marc

2014-09-01

We present a spectral mimetic least-squares method for a model diffusion–reaction problem, which preserves key conservation properties of the continuum problem. Casting the model problem into a first-order system for two scalar and two vector variables shifts material properties from the differential equations to a pair of constitutive relations. We also use this system to motivate a new least-squares functional involving all four fields and show that its minimizer satisfies the differential equations exactly. Discretization of the four-field least-squares functional by spectral spaces compatible with the differential operators leads to a least-squares method in which the differential equations are alsomore » satisfied exactly. Additionally, the latter are reduced to purely topological relationships for the degrees of freedom that can be satisfied without reference to basis functions. Furthermore, numerical experiments confirm the spectral accuracy of the method and its local conservation.« less

To the theory of non-local non-isothermal filtration in porous medium

NASA Astrophysics Data System (ADS)

Meilanov, R. R.; Akhmedov, E. N.; Beybalaev, V. D.; Magomedov, R. A.; Ragimkhanov, G. B.; Aliverdiev, A. A.

2018-01-01

A new approach to the theory of non-local and non-isothermal filtration based on the mathematical apparatus of fractional order derivatives is developing. A solution of the Cauchy problem for the system of equations of non-local non-isothermal filtration in fractional calculus is obtained. Some applications of the solutions obtained to the problems of underground hydrodynamics (fracturing and explosion) are considered. A computational experiment was carried out to analyze the solutions obtained. Graphs of pressure and temperature dependences are plotted against time.

Novel water filtration of saline water in the outermost layer of mangrove roots.

PubMed

Kim, Kiwoong; Seo, Eunseok; Chang, Suk-Kyu; Park, Tae Jung; Lee, Sang Joon

2016-02-05

The scarcity of fresh water is a global challenge faced at present. Several desalination methods have been suggested to secure fresh water from sea water. However, conventional methods suffer from technical limitations, such as high power consumption, expensive operating costs, and limited system durability. In this study, we examined the feasibility of using halophytes as a novel technology of desalinating high-concentration saline water for long periods. This study investigated the biophysical characteristics of sea water filtration in the roots of the mangrove Rhizophora stylosa from a plant hydrodynamic point of view. R. stylosa can grow even in saline water, and the salt level in its roots is regulated within a certain threshold value through filtration. The root possesses a hierarchical, triple layered pore structure in the epidermis, and most Na(+) ions are filtered at the first sublayer of the outermost layer. The high blockage of Na(+) ions is attributed to the high surface zeta potential of the first layer. The second layer, which is composed of macroporous structures, also facilitates Na(+) ion filtration. This study provides insights into the mechanism underlying water filtration through halophyte roots and serves as a basis for the development of a novel bio-inspired desalination method.

Spectral Imaging of Portolan Charts

NASA Astrophysics Data System (ADS)

France, Fenella G.; Wilson, Meghan A.; Ghez, Anita

2018-05-01

Spectral imaging of Portolan Charts, early nautical charts, provided extensive new information about their construction and creation. The origins of the portolan chart style have been a continual source of perplexity to numerous generations of cartographic historians. The spectral imaging system utilized incorporates a 50 megapixel mono-chrome camera with light emitting diode (LED) illumination panels that cover the range from 365 nm to 1050 nm to capture visible and non-visible information. There is little known about how portolan charts evolved, and what influenced their creation. These early nautical charts began as working navigational tools of medieval mariners, initially made in the 1300s in Italy, Portugal and Spain; however the origin and development of the portolan chart remained shrouded in mystery. Questions about these early navigational charts included whether colorants were commensurate with the time period and geographical location, and if different, did that give insight into trade routes, or possible later additions to the charts? For example; spectral data showed the red pigment on both the 1320 portolan chart and the 1565 Galapagos Islands matched vermillion, an opaque red pigment used since antiquity. The construction of these charts was also of great interest. Spectral imaging with a range of illumination modes revealed the presence of a "hidden circle" often referred to in relation to their construction. This paper will present in-depth analysis of how spectral imaging of the Portolans revealed similarities and differences, new hidden information and shed new light on construction and composition.

Biofilm Filtrates of Pseudomonas aeruginosa Strains Isolated from Cystic Fibrosis Patients Inhibit Preformed Aspergillus fumigatus Biofilms via Apoptosis

PubMed Central

Shirazi, Fazal; Ferreira, Jose A. G.; Stevens, David A.; Clemons, Karl V.; Kontoyiannis, Dimitrios P.

2016-01-01

Pseudomonas aeruginosa (Pa) and Aspergillus fumigatus (Af) colonize cystic fibrosis (CF) patient airways. Pa culture filtrates inhibit Af biofilms, and Pa non-CF, mucoid (Muc-CF) and nonmucoid CF (NMuc-CF) isolates form an ascending inhibitory hierarchy. We hypothesized this activity is mediated through apoptosis induction. One Af and three Pa (non-CF, Muc-CF, NMuc-CF) reference isolates were studied. Af biofilm was formed in 96 well plates for 16 h ± Pa biofilm filtrates. After 24 h, apoptosis was characterized by viability dye DiBAc, reactive oxygen species (ROS) generation, mitochondrial membrane depolarization, DNA fragmentation and metacaspase activity. Muc-CF and NMuc-CF filtrates inhibited and damaged Af biofilm (p<0.0001). Intracellular ROS levels were elevated (p<0.001) in NMuc-CF-treated Af biofilms (3.7- fold) compared to treatment with filtrates from Muc-CF- (2.5- fold) or non-CF Pa (1.7- fold). Depolarization of mitochondrial potential was greater upon exposure to NMuc-CF (2.4-fold) compared to Muc-CF (1.8-fold) or non-CF (1.25-fold) (p<0.0001) filtrates. Exposure to filtrates resulted in more DNA fragmentation in Af biofilm, compared to control, mediated by metacaspase activation. In conclusion, filtrates from CF-Pa isolates were more inhibitory against Af biofilms than from non-CF. The apoptotic effect involves mitochondrial membrane damage associated with metacaspase activation. PMID:26930399

Biofilm Filtrates of Pseudomonas aeruginosa Strains Isolated from Cystic Fibrosis Patients Inhibit Preformed Aspergillus fumigatus Biofilms via Apoptosis.

PubMed

Shirazi, Fazal; Ferreira, Jose A G; Stevens, David A; Clemons, Karl V; Kontoyiannis, Dimitrios P

2016-01-01

Pseudomonas aeruginosa (Pa) and Aspergillus fumigatus (Af) colonize cystic fibrosis (CF) patient airways. Pa culture filtrates inhibit Af biofilms, and Pa non-CF, mucoid (Muc-CF) and nonmucoid CF (NMuc-CF) isolates form an ascending inhibitory hierarchy. We hypothesized this activity is mediated through apoptosis induction. One Af and three Pa (non-CF, Muc-CF, NMuc-CF) reference isolates were studied. Af biofilm was formed in 96 well plates for 16 h ± Pa biofilm filtrates. After 24 h, apoptosis was characterized by viability dye DiBAc, reactive oxygen species (ROS) generation, mitochondrial membrane depolarization, DNA fragmentation and metacaspase activity. Muc-CF and NMuc-CF filtrates inhibited and damaged Af biofilm (p<0.0001). Intracellular ROS levels were elevated (p<0.001) in NMuc-CF-treated Af biofilms (3.7- fold) compared to treatment with filtrates from Muc-CF- (2.5- fold) or non-CF Pa (1.7- fold). Depolarization of mitochondrial potential was greater upon exposure to NMuc-CF (2.4-fold) compared to Muc-CF (1.8-fold) or non-CF (1.25-fold) (p<0.0001) filtrates. Exposure to filtrates resulted in more DNA fragmentation in Af biofilm, compared to control, mediated by metacaspase activation. In conclusion, filtrates from CF-Pa isolates were more inhibitory against Af biofilms than from non-CF. The apoptotic effect involves mitochondrial membrane damage associated with metacaspase activation.

Spectral confocal reflection microscopy using a white light source

NASA Astrophysics Data System (ADS)

Booth, M.; Juškaitis, R.; Wilson, T.

2008-08-01

We present a reflection confocal microscope incorporating a white light supercontinuum source and spectral detection. The microscope provides images resolved spatially in three-dimensions, in addition to spectral resolution covering the wavelength range 450-650nm. Images and reflection spectra of artificial and natural specimens are presented, showing features that are not normally revealed in conventional microscopes or confocal microscopes using discrete line lasers. The specimens include thin film structures on semiconductor chips, iridescent structures in Papilio blumei butterfly scales, nacre from abalone shells and opal gemstones. Quantitative size and refractive index measurements of transparent beads are derived from spectral interference bands.

RIVERBANK FILTRATION: EFFECT OF GROUND PASSAGE ON NOM CHARACTER

EPA Science Inventory

Research was conducted to explore the effect of underground travel on the character of the natural organic matter (NOM) originating from the river water source during riverbank filtration (RBF) at three Midwestern US drinking water utilities. Measurements of biodegradable dissolv...

Normalized spectral damage of a linear system over different spectral loading patterns

NASA Astrophysics Data System (ADS)

Kim, Chan-Jung

2017-08-01

Spectral fatigue damage is affected by different loading patterns; the damage may be accumulated in a different manner because the spectral pattern has an influence on stresses or strains. The normalization of spectral damage with respect to spectral loading acceleration is a novel solution to compare the accumulated fatigue damage over different spectral loading patterns. To evaluate the sensitivity of fatigue damage over different spectral loading cases, a simple notched specimen is used to conduct a uniaxial vibration test for two representative spectral patterns-random and harmonic-between 30 and 3000 Hz. The fatigue damage to the simple specimen is analyzed for different spectral loading cases using the normalized spectral damage from the measured response data for both acceleration and strain. The influence of spectral loading patterns is discussed based on these analyses.

Technical characterization of dialysis fluid flow and mass transfer rate in dialyzers with various filtration coefficients using dimensionless correlation equation.

PubMed

Fukuda, Makoto; Yoshimura, Kengo; Namekawa, Koki; Sakai, Kiyotaka

2017-06-01

The objective of the present study is to evaluate the effect of filtration coefficient and internal filtration on dialysis fluid flow and mass transfer coefficient in dialyzers using dimensionless mass transfer correlation equations. Aqueous solution of vitamin B 12 clearances were obtained for REXEED-15L as a low flux dialyzer, and APS-15EA and APS-15UA as high flux dialyzers. All the other design specifications were identical for these dialyzers except for filtration coefficient. The overall mass transfer coefficient was calculated, moreover, the exponents of Reynolds number (Re) and film mass transfer coefficient of the dialysis-side fluid (k D ) for each flow rate were derived from the Wilson plot and dimensionless correlation equation. The exponents of Re were 0.4 for the low flux dialyzer whereas 0.5 for the high flux dialyzers. Dialysis fluid of the low flux dialyzer was close to laminar flow because of its low filtration coefficient. On the other hand, dialysis fluid of the high flux dialyzers was assumed to be orthogonal flow. Higher filtration coefficient was associated with higher k D influenced by mass transfer rate through diffusion and internal filtration. Higher filtration coefficient of dialyzers and internal filtration affect orthogonal flow of dialysis fluid.

Gravity filtration performances of the bio-diatomite dynamic membrane reactor for slightly polluted surface water purification.

PubMed

Chu, Huaqiang; Dong, Bingzhi; Zhang, Yalei; Zhou, Xuefei

2012-01-01

A bio-diatomite dynamic membrane (BDDM) reactor for surface water treatment under a water head of 30, 40, 50, 60 and 70 cm, respectively, was investigated, which was very effective for pollutants removal. The water head exerted strong influences on filtration flux of BDDM during the precoating process, as well as on the formation of BDDM and turbidity variations. A high filtration flux (approximately 200-300 L/m2 h) could be achieved in the long filtration times of BDDM with a stable effluent turbidity of approximately 0.11-0.25 NTU. The BDDM could remove particles larger than 25 μm completely. The adopted sintered diatomite mainly consisted of macro pores, which were beneficial for improving the filtration flux of BDDM. During the backwash stage, the BDDM could be removed completely by the air backwash.

Spectral mapping tools from the earth sciences applied to spectral microscopy data.

PubMed

Harris, A Thomas

2006-08-01

Spectral imaging, originating from the field of earth remote sensing, is a powerful tool that is being increasingly used in a wide variety of applications for material identification. Several workers have used techniques like linear spectral unmixing (LSU) to discriminate materials in images derived from spectral microscopy. However, many spectral analysis algorithms rely on assumptions that are often violated in microscopy applications. This study explores algorithms originally developed as improvements on early earth imaging techniques that can be easily translated for use with spectral microscopy. To best demonstrate the application of earth remote sensing spectral analysis tools to spectral microscopy data, earth imaging software was used to analyze data acquired with a Leica confocal microscope with mechanical spectral scanning. For this study, spectral training signatures (often referred to as endmembers) were selected with the ENVI (ITT Visual Information Solutions, Boulder, CO) "spectral hourglass" processing flow, a series of tools that use the spectrally over-determined nature of hyperspectral data to find the most spectrally pure (or spectrally unique) pixels within the data set. This set of endmember signatures was then used in the full range of mapping algorithms available in ENVI to determine locations, and in some cases subpixel abundances of endmembers. Mapping and abundance images showed a broad agreement between the spectral analysis algorithms, supported through visual assessment of output classification images and through statistical analysis of the distribution of pixels within each endmember class. The powerful spectral analysis algorithms available in COTS software, the result of decades of research in earth imaging, are easily translated to new sources of spectral data. Although the scale between earth imagery and spectral microscopy is radically different, the problem is the same: mapping material locations and abundances based on unique

Properties of Spectral Shapes of Whistler-Mode Emissions

NASA Astrophysics Data System (ADS)

Macusova, E.; Santolik, O.; Pickett, J. S.; Gurnett, D. A.; Cornilleau-Wehrlin, N.

2014-12-01

Whistler-mode emissions play an important role in wave-particle interactions occurring in the radiation belt region. Whistler mode chorus emissions consist of discrete wave packets which exhibit different spectral shapes. Rising tones (events with positive value of the frequency sweep rate) are frequently observed. Other categories of chorus spectral shapes, such as falling tones, hooks, broadband patterns, are also known. Whistler-mode emissions can additionally occur as hiss or combinations of hiss with discrete patterns. In this study, we have analyzed more than 11 years of high-time resolution measurements provided by the Wideband Data (WBD) instrument onboard four Cluster spacecraft to identify different spectral shapes of whistler mode emissions. We determine the distribution of individual groups of chorus spectral shapes in the Earth's magnetosphere and the effect of the different geomagnetic conditions on their occurrence. We focus on average polarization and propagation properties of the different types of spectral shapes, obtained during visually identified time intervals from multicomponent measurements of the STAFF-SA instrument recorded with a time resolution of 4 seconds.

Aging and physiological changes of the kidneys including changes in glomerular filtration rate.

PubMed

Musso, Carlos G; Oreopoulos, Dimitrios G

2011-01-01

In addition to the structural changes in the kidney associated with aging, physiological changes in renal function are also found in older adults, such as decreased glomerular filtration rate, vascular dysautonomia, altered tubular handling of creatinine, reduction in sodium reabsorption and potassium secretion, and diminished renal reserve. These alterations make aged individuals susceptible to the development of clinical conditions in response to usual stimuli that would otherwise be compensated for in younger individuals, including acute kidney injury, volume depletion and overload, disorders of serum sodium and potassium concentration, and toxic reactions to water-soluble drugs excreted by the kidneys. Additionally, the preservation with aging of a normal urinalysis, normal serum urea and creatinine values, erythropoietin synthesis, and normal phosphorus, calcium and magnesium tubular handling distinguishes decreased GFR due to normal aging from that due to chronic kidney disease. Copyright © 2011 S. Karger AG, Basel.

The use of an air filtration system in podiatry clinics.

PubMed

McLarnon, Nichola; Burrow, Gordon; Maclaren, William; Aidoo, Kofi; Hepher, Mike

2003-06-01

A small-scale study was conducted to ascertain the efficiency and effectiveness of an air filtration system for use in podiatry/chiropody clinics (Electromedia Model 35F (A), Clean Air Ltd, Scotland, UK). Three clinics were identified, enabling comparison of data between podiatry clinics in the West of Scotland. The sampling was conducted using a portable Surface Air Sampler (Cherwell Laboratories, Bicester, UK). Samples were taken on two days at three different times before and after installation of the filtration units. The global results of the study indicate the filter has a statistically significant effect on microbial counts, with an average percentage decrease of 65%. This study is the first time, to the authors' knowledge, such a system has been tested within podiatric practice.

Simultaneous assessment of glomerular filtration and barrier function in live zebrafish

PubMed Central

Kotb, Ahmed M.; Müller, Tobias; Xie, Jing; Anand-Apte, Bela; Endlich, Nicole

2014-01-01

The zebrafish pronephros is a well-established model to study glomerular development, structure, and function. A few methods have been described to evaluate glomerular barrier function in zebrafish larvae so far. However, there is a need to assess glomerular filtration as well. In the present study, we extended the available methods by simultaneously measuring the intravascular clearances of Alexa fluor 647-conjugated 10-kDa dextran and FITC-conjugated 500-kDa dextran as indicators of glomerular filtration and barrier function, respectively. After intravascular injection of the dextrans, mean fluorescence intensities of both dextrans were measured in the cardinal vein of living zebrafish (4 days postfertilization) by confocal microscopy over time. We demonstrated that injected 10-kDa dextran was rapidly cleared from the circulation, became visible in the lumen of the pronephric tubule, quickly accumulated in tubular cells, and was detectably excreted at the cloaca. In contrast, 500-kDa dextran could not be visualized in the tubule at any time point. To check whether alterations in glomerular function can be quantified by our method, we injected morpholino oligonucleotides (MOs) against zebrafish nonmuscle myosin heavy chain IIA (zMyh9) or apolipoprotein L1 (zApol1). While glomerular filtration was reduced in zebrafish nonmuscle myosin heavy chain IIA MO-injected larvae, glomerular barrier function remained intact. In contrast, in zebrafish apolipoprotein L1 MO-injected larvae, glomerular barrier function was compromised as 500-kDa dextran disappeared from the circulation and became visible in tubular cells. In summary, we present a novel method that allows to simultaneously assess glomerular filtration and barrier function in live zebrafish. PMID:25298528

Filtration of human EEG recordings from physiological artifacts with empirical mode method

NASA Astrophysics Data System (ADS)

Grubov, Vadim V.; Runnova, Anastasiya E.; Khramova, Marina V.

2017-03-01

In the paper we propose the new method for dealing with noise and physiological artifacts in experimental human EEG recordings. The method is based on analysis of EEG signals with empirical mode decomposition (Hilbert-Huang transform). We consider noises and physiological artifacts on EEG as specific oscillatory patterns that cause problems during EEG analysis and can be detected with additional signals recorded simultaneously with EEG (ECG, EMG, EOG, etc.) We introduce the algorithm of the method with following steps: empirical mode decomposition of EEG signal, choosing of empirical modes with artifacts, removing empirical modes with artifacts, reconstruction of the initial EEG signal. We test the method on filtration of experimental human EEG signals from eye-moving artifacts and show high efficiency of the method.

STUDY OF WATER QUALITY IMPROVEMENTS DURING RIVERBANK FILTRATION AT THREE MIDWESTERN UNITED STATES DRINKING WATER UTILITIES

EPA Science Inventory

Riverbank filtration (RBF) is a process during which surface water is subjected to subsurface flow prior to extraction from wells. During infiltration and soil passage, surface water is subjected to a combination of physical, chemical, and biological processes such as filtration...

Combining spectral material properties in the infrared and the visible spectral range for qualification and nondestructive evaluation of components

NASA Astrophysics Data System (ADS)

Eisler, K.; Goldammer, M.; Rothenfusser, M.; Arnold, W.; Homma, C.

2012-05-01

The spectral selective thermography with infrared filters can be used to determine or to distinguish materials such as contaminations on a metallic component. With additional visual information, the indications by the IR signal can be selectively accentuated or suppressed for easier evaluation of passive and active thermography measurements. For flash thermography the detected IR signal between 3.4 and 5.1 μm is analyzed with regard to the spectral material information. The presented hybrid camera uses beam overlapping to obtain combined images of both in the infrared and the visual range.

Spectral action models of gravity on packed swiss cheese cosmology

NASA Astrophysics Data System (ADS)

Ball, Adam; Marcolli, Matilde

2016-06-01

We present a model of (modified) gravity on spacetimes with fractal structure based on packing of spheres, which are (Euclidean) variants of the packed swiss cheese cosmology models. As the action functional for gravity we consider the spectral action of noncommutative geometry, and we compute its expansion on a space obtained as an Apollonian packing of three-dimensional spheres inside a four-dimensional ball. Using information from the zeta function of the Dirac operator of the spectral triple, we compute the leading terms in the asymptotic expansion of the spectral action. They consist of a zeta regularization of the divergent sum of the leading terms of the spectral actions of the individual spheres in the packing. This accounts for the contribution of points 1 and 3 in the dimension spectrum (as in the case of a 3-sphere). There is an additional term coming from the residue at the additional point in the real dimension spectrum that corresponds to the packing constant, as well as a series of fluctuations coming from log-periodic oscillations, created by the points of the dimension spectrum that are off the real line. These terms detect the fractality of the residue set of the sphere packing. We show that the presence of fractality influences the shape of the slow-roll potential for inflation, obtained from the spectral action. We also discuss the effect of truncating the fractal structure at a certain scale related to the energy scale in the spectral action.

Experimental prestorage filtration removes antibodies and decreases lipids in RBC supernatants mitigating TRALI in vivo

PubMed Central

Kelher, Marguerite R.; Khan, Samina Y.; LaSarre, Monica; West, F. Bernadette; Land, Kevin J.; Mish, Barbara; Ceriano, Linda; Sowemimo-Coker, Samuel

2014-01-01

Transfusion-related acute lung injury (TRALI) remains a significant cause of transfusion-related mortality with red cell transfusion. We hypothesize that prestorage filtration may reduce proinflammatory activity in the red blood cell (RBC) supernatant and prevent TRALI. Filters were manufactured for both small volumes and RBC units. Plasma containing antibodies to human lymphocyte antigen (HLA)-A2 or human neutrophil antigen (HNA)-3a was filtered, and immunoglobulins and specific HNA-3a and HLA-2a neutrophil (PMN) priming activity were measured. Antibodies to OX27 were added to plasma, and filtration was evaluated in a 2-event animal model of TRALI. RBC units from 31 donors known to have antibodies against HLA antigens and from 16 antibody-negative controls were filtered. Furthermore, 4 RBC units were drawn and underwent standard leukoreduction. Immunoglobulins, HLA antibodies, PMN priming activity, and the ability to induce TRALI in an animal model were measured. Small-volume filtration of plasma removed >96% of IgG, antibodies to HLA-A2 and HNA-3a, and their respective priming activity, as well as mitigating antibody-mediated in vivo TRALI. In RBC units, experimental filtration removed antibodies to HLA antigens and inhibited the accumulation of lipid priming activity and lipid-mediated TRALI. We conclude that filtration removes proinflammatory activity and the ability to induce TRALI from RBCs and may represent a TRALI mitigation step. PMID:24747436

ADVANCED ELECTROSTATIC STIMULATION OF FABRIC FILTRATION: PERFORMANCE AND ECONOMICS

EPA Science Inventory

The paper discusses the performance and economics of advanced electrostatic stimulation of fabric filtration (AESFF), in which a high-voltage electrode is placed coaxially inside a filter bag to establish an electric field between the electrode and the bag surface. The electric f...

Impact of estimated glomerular filtration rate on diabetic macular edema.

PubMed

Temkar, Shreyas; Karuppaiah, Nishanthini; Takkar, Brijesh; Bhowmik, Dipankar; Tripathi, Manjari; Ramakrishnan, Sivasubramanian; Sharma, Yog Raj; Vohra, Rajpal; Chawla, Rohan; Venkatesh, Pradeep

2018-06-01

Diabetic macular edema (DME) is a major cause of visual impairment in patients with diabetes and is influenced by various systemic factors. This study evaluates the effect of renal status on DME using estimated glomerular filtration rate (eGFR) as a study marker. This was a prospective observational cross-sectional study. One hundred and ninety-five patients of diabetic retinopathy (DR) were included. Group 1 had patients of DR without DME (n = 100), and group 2 had patients of DR with DME (n = 95). All patients were evaluated for DR/DME-related risk factors. eGFR was calculated in all patients. Spectral domain optical coherence tomography (SDOCT) was done to identify the various patterns and severity of DME. Group 2 patients had significantly higher comorbidities than those in group 1 (p < 0.001). Hba1c, total cholesterol, triglycerides, LDL/HDL ratio, systolic and diastolic blood pressures were significantly higher in group II (p < 0.001 in each). There was no significant difference between the groups in terms of blood urea, serum creatinine or eGFR. eGFR did not show a significant association with a specific SDOCT pattern or severity of DME. Comorbidities are more common and more severe in patients with DME. However, eGFR as a marker was not useful in predicting either the severity or pattern of DME. eGFR, in its present form, may not be useful in the evaluation and management of patients with DME.

Aluminium - Cobalt-Pillared Clay for Dye Filtration Membrane

NASA Astrophysics Data System (ADS)

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.

40 CFR 141.711 - Filtered system additional Cryptosporidium treatment requirements.

Code of Federal Regulations, 2013 CFR

2013-07-01

... AGENCY (CONTINUED) WATER PROGRAMS (CONTINUED) NATIONAL PRIMARY DRINKING WATER REGULATIONS Enhanced...(including softening) Direct filtration Slow sand or diatomaceous earth filtration Alternative filtration... survey or an equivalent source water assessment that after a system completed the monitoring conducted...

40 CFR 141.711 - Filtered system additional Cryptosporidium treatment requirements.

Code of Federal Regulations, 2012 CFR

2012-07-01

... AGENCY (CONTINUED) WATER PROGRAMS (CONTINUED) NATIONAL PRIMARY DRINKING WATER REGULATIONS Enhanced...(including softening) Direct filtration Slow sand or diatomaceous earth filtration Alternative filtration... survey or an equivalent source water assessment that after a system completed the monitoring conducted...

40 CFR 141.711 - Filtered system additional Cryptosporidium treatment requirements.

Code of Federal Regulations, 2014 CFR

2014-07-01

... AGENCY (CONTINUED) WATER PROGRAMS (CONTINUED) NATIONAL PRIMARY DRINKING WATER REGULATIONS Enhanced...(including softening) Direct filtration Slow sand or diatomaceous earth filtration Alternative filtration... survey or an equivalent source water assessment that after a system completed the monitoring conducted...

Filtrations on Springer fiber cohomology and Kostka polynomials

NASA Astrophysics Data System (ADS)

Bellamy, Gwyn; Schedler, Travis

2018-03-01

We prove a conjecture which expresses the bigraded Poisson-de Rham homology of the nilpotent cone of a semisimple Lie algebra in terms of the generalized (one-variable) Kostka polynomials, via a formula suggested by Lusztig. This allows us to construct a canonical family of filtrations on the flag variety cohomology, and hence on irreducible representations of the Weyl group, whose Hilbert series are given by the generalized Kostka polynomials. We deduce consequences for the cohomology of all Springer fibers. In particular, this computes the grading on the zeroth Poisson homology of all classical finite W-algebras, as well as the filtration on the zeroth Hochschild homology of all quantum finite W-algebras, and we generalize to all homology degrees. As a consequence, we deduce a conjecture of Proudfoot on symplectic duality, relating in type A the Poisson homology of Slodowy slices to the intersection cohomology of nilpotent orbit closures. In the last section, we give an analogue of our main theorem in the setting of mirabolic D-modules.

Technology for detecting spectral radiance by a snapshot multi-imaging spectroradiometer

NASA Astrophysics Data System (ADS)

Zuber, Ralf; Stührmann, Ansgar; Gugg-Helminger, Anton; Seckmeyer, Gunther

2017-12-01

Technologies to determine spectral sky radiance distributions have evolved in recent years and have enabled new applications in remote sensing, for sky radiance measurements, in biological/diagnostic applications and luminance measurements. Most classical spectral imaging radiance technologies are based on mechanical and/or spectral scans. However, these methods require scanning time in which the spectral radiance distribution might change. To overcome this limitation, different so-called snapshot spectral imaging technologies have been developed that enable spectral and spatial non-scanning measurements. We present a new setup based on a facet mirror that is already used in imaging slicing spectrometers. By duplicating the input image instead of slicing it and using a specially designed entrance slit, we are able to select nearly 200 (14 × 14) channels within the field of view (FOV) for detecting spectral radiance in different directions. In addition, a megapixel image of the FOV is captured by an additional RGB camera. This image can be mapped onto the snapshot spectral image. In this paper, the mechanical setup, technical design considerations and first measurement results of a prototype are presented. For a proof of concept, the device is radiometrically calibrated and a 10 mm × 10 mm test pattern measured within a spectral range of 380 nm-800 nm with an optical bandwidth of 10 nm (full width at half maximum or FWHM). To show its potential in the UV spectral region, zenith sky radiance measurements in the UV of a clear sky were performed. Hence, the prototype was equipped with an entrance optic with a FOV of 0.5° and modified to obtain a radiometrically calibrated spectral range of 280 nm-470 nm with a FWHM of 3 nm. The measurement results have been compared to modeled data processed by UVSPEC, which showed deviations of less than 30%. This is far from being ideal, but an acceptable result with respect to available state

Purification of inkjet ink from water using liquid phase, electric discharge polymerization and cellulosic membrane filtration.

PubMed

Jordan, Alexander T; Hsieh, Jeffery S; Lee, Daniel T

2013-01-01

A method to separate inkjet ink from water was developed using a liquid phase, electric discharge process. The liquid phase, electric discharge process with filtration or sedimentation was shown to remove 97% of inkjet ink from solutions containing between 0.1-0.8 g/L and was consistent over a range of treatment conditions. Additionally, particle size analysis of treated allyl alcohol and treated propanol confirmed the electric discharge treatment has a polymerization mechanism, and small molecule analysis of treated methanol using gas chromatography and mass spectroscopy confirmed the mechanism was free radical initiated polymerization.

Introduction of filtration systems in container nurseries for nonchemical elimination of Phytophthora spp. from irrigation water

Treesearch

Thorsten Ufer; Heinrich Beltz; Thomas Brand; Katrin Kaminski; Ralf Lüttmann; Martin Posner; Stefan Wagner; Sabine Werres; Hans-Peter Wessels

2006-01-01

In a 3-year project the elimination of Phytophthora spp. from the recirculation water with different kinds of filtration systems will be tested under commercial conditions in container nurseries. First results indicate that the filtration systems eliminate Phytophthora spp. from the water.

Water Filtration Using Plant Xylem

PubMed Central

Chambers, Valerie; Venkatesh, Varsha; Karnik, Rohit

2014-01-01

Effective point-of-use devices for providing safe drinking water are urgently needed to reduce the global burden of waterborne disease. Here we show that plant xylem from the sapwood of coniferous trees – a readily available, inexpensive, biodegradable, and disposable material – can remove bacteria from water by simple pressure-driven filtration. Approximately 3 cm3 of sapwood can filter water at the rate of several liters per day, sufficient to meet the clean drinking water needs of one person. The results demonstrate the potential of plant xylem to address the need for pathogen-free drinking water in developing countries and resource-limited settings. PMID:24587134

Capillary filtration in venous hypertension. Comparison between the vacuum suction chamber (VSC) device and straingauge phlethysmography.

PubMed

Belcaro, G; Rulo, A; Renton, S

1992-01-01

To evaluate capillary filtration a group of normal subjects and two groups of subjects with venous incompetence (50 with deep and 50 with superficial incompetence) were studied with the vacuum suction chamber (VSC) device applied onto the internal perimalleolar region. This method was compared with straingauge plethysmography rate of ankle swelling (RAS). By the VSC the time taken for the weal to disappear (VSC time) was considered indicative of capillary filtration. The values obtained with the two methods were well related (r < 0.742) and there was a good separation between patients and normals. The separation between the two groups of patients was significantly better (p < 0.05) with the VSC time. In conclusion VSC time is a good indication of capillary filtration in comparison with straingauge plethysmography RAS. It may be used to assess variations in capillary filtration in venous hypertension and possibly to follow up the effects of treatments.

Air filtration in the free molecular flow regime: a review of high-efficiency particulate air filters based on carbon nanotubes.

PubMed

Li, Peng; Wang, Chunya; Zhang, Yingying; Wei, Fei

2014-11-01

Air filtration in the free molecular flow (FMF) regime is important and challenging because a higher filtration efficiency and lower pressure drop are obtained when the fiber diameter is smaller than the gas mean free path in the FMF regime. In previous studies, FMF conditions have been obtained by increasing the gas mean free path through reducing the pressure and increasing the temperature. In the case of carbon nanotubes (CNTs) with nanoscale diameters, it is possible to filtrate in the FMF regime under normal conditions. This paper reviews recent progress in theoretical and experimental studies of air filtration in the FMF regime. Typical structure models of high-efficiency particulate (HEPA) air filters based on CNTs are introduced. The pressure drop in air filters operated in the FMF regime is less than that predicted by the conventional air filtration theory. The thinnest HEPA filters fabricated from single-walled CNT films have an extremely low pressure drop. CNT air filters with a gradient nanostructure are shown to give a much better filtration performance in dynamic filtration. CNT air filters with a hierarchical structure and an agglomerated CNT fluidized bed air filter are also introduced. Finally, the challenges and opportunities for the application of CNTs in air filtration are discussed. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Application of quantitative real-time PCR compared to filtration methods for the enumeration of Escherichia coli in surface waters within Vietnam.

PubMed

Vital, Pierangeli G; Van Ha, Nguyen Thi; Tuyet, Le Thi Hong; Widmer, Kenneth W

2017-02-01

Surface water samples in Vietnam were collected from the Saigon River, rural and suburban canals, and urban runoff canals in Ho Chi Minh City, Vietnam, and were processed to enumerate Escherichia coli. Quantification was done through membrane filtration and quantitative real-time polymerase chain reaction (PCR). Mean log colony-forming unit (CFU)/100 ml E. coli counts in the dry season for river/suburban canals and urban canals were log 2.8 and 3.7, respectively, using a membrane filtration method, while using Taqman quantitative real-time PCR they were log 2.4 and 2.8 for river/suburban canals and urban canals, respectively. For the wet season, data determined by the membrane filtration method in river/suburban canals and urban canals samples had mean counts of log 3.7 and 4.1, respectively. While mean log CFU/100 ml counts in the wet season using quantitative PCR were log 3 and 2, respectively. Additionally, the urban canal samples were significantly lower than those determined by conventional culture methods for the wet season. These results show that while quantitative real-time PCR can be used to determine levels of fecal indicator bacteria in surface waters, there are some limitations to its application and it may be impacted by sources of runoff based on surveyed samples.

Spectral variability among rocks in visible and near-infrared mustispectral Pancam data collected at Gusev crater: Examinations using spectral mixture analysis and related techniques

USGS Publications Warehouse

Farrand, W. H.; Bell, J.F.; Johnson, J. R.; Squyres, S. W.; Soderblom, J.; Ming, D. W.

2006-01-01

Visible and near-infrared (VNIR) multispectral observations of rocks made by the Mars Exploration Rover Spirit's Panoramic camera (Pancam) have been analyzed using a spectral mixture analysis (SMA) methodology. Scenes have been examined from the Gusev crater plains into the Columbia Hills. Most scenes on the plains and in the Columbia Hills could be modeled as three end-member mixtures of a bright material, rock, and shade. Scenes of rocks disturbed by the rover's Rock Abrasion Tool (RAT) required additional end-members. In the Columbia Hills, there were a number of scenes in which additional rock end-members were required. The SMA methodology identified relatively dust-free areas on undisturbed rock surfaces as well as spectrally unique areas on RAT abraded rocks. Spectral parameters from these areas were examined, and six spectral classes were identified. These classes are named after a type rock or area and are Adirondack, Lower West Spur, Clovis, Wishstone, Peace, and Watchtower. These classes are discriminable based, primarily, on near-infrared (NIR) spectral parameters. Clovis and Watchtower class rocks appear more oxidized than Wishstone class rocks and Adirondack basalts based on their having higher 535 nm band depths. Comparison of the spectral parameters of these Gusev crater rocks to parameters of glass-dominated basaltic tuffs indicates correspondence between measurements of Clovis and Watchtower classes but divergence for the Wishstone class rocks, which appear to have a higher fraction of crystalline ferrous iron-bearing phases. Despite a high sulfur content, the rock Peace has NIR properties resembling plains basalts. Copyright 2006 by the American Geophysical Union.

Spectral Variability among Rocks in Visible and Near Infrared Multispectral Pancam Data Collected at Gusev Crater: Examinations using Spectral Mixture Analysis and Related Techniques

NASA Technical Reports Server (NTRS)

Farrand, W. H.; Bell, J. F., III; Johnson, J. R.; Squyres, S. W.; Soderblom, J.; Ming, D. W.

2006-01-01

Visible and Near Infrared (VNIR) multispectral observations of rocks made by the Mars Exploration Rover Spirit s Panoramic camera (Pancam) have been analysed using a spectral mixture analysis (SMA) methodology. Scenes have been examined from the Gusev crater plains into the Columbia Hills. Most scenes on the plains and in the Columbia Hills could be modeled as three endmember mixtures of a bright material, rock, and shade. Scenes of rocks disturbed by the rover s Rock Abrasion Tool (RAT) required additional endmembers. In the Columbia Hills there were a number of scenes in which additional rock endmembers were required. The SMA methodology identified relatively dust-free areas on undisturbed rock surfaces, as well as spectrally unique areas on RAT abraded rocks. Spectral parameters from these areas were examined and six spectral classes were identified. These classes are named after a type rock or area and are: Adirondack, Lower West Spur, Clovis, Wishstone, Peace, and Watchtower. These classes are discriminable based, primarily, on near-infrared (NIR) spectral parameters. Clovis and Watchtower class rocks appear more oxidized than Wishstone class rocks and Adirondack basalts based on their having higher 535 nm band depths. Comparison of the spectral parameters of these Gusev crater rocks to parameters of glass-dominated basaltic tuffs indicates correspondence between measurements of Clovis and Watchtower classes, but divergence for the Wishstone class rocks which appear to have a higher fraction of crystalline ferrous iron bearing phases. Despite a high sulfur content, the rock Peace has NIR properties resembling plains basalts.

Spectrally interleaved, comb-mode-resolved spectroscopy using swept dual terahertz combs

PubMed Central

Hsieh, Yi-Da; Iyonaga, Yuki; Sakaguchi, Yoshiyuki; Yokoyama, Shuko; Inaba, Hajime; Minoshima, Kaoru; Hindle, Francis; Araki, Tsutomu; Yasui, Takeshi

2014-01-01

Optical frequency combs are innovative tools for broadband spectroscopy because a series of comb modes can serve as frequency markers that are traceable to a microwave frequency standard. However, a mode distribution that is too discrete limits the spectral sampling interval to the mode frequency spacing even though individual mode linewidth is sufficiently narrow. Here, using a combination of a spectral interleaving and dual-comb spectroscopy in the terahertz (THz) region, we achieved a spectral sampling interval equal to the mode linewidth rather than the mode spacing. The spectrally interleaved THz comb was realized by sweeping the laser repetition frequency and interleaving additional frequency marks. In low-pressure gas spectroscopy, we achieved an improved spectral sampling density of 2.5 MHz and enhanced spectral accuracy of 8.39 × 10−7 in the THz region. The proposed method is a powerful tool for simultaneously achieving high resolution, high accuracy, and broad spectral coverage in THz spectroscopy. PMID:24448604

Field Performance of a Newly Developed Upflow Filtration Device

EPA Science Inventory

The objective of this research is to examine the removal capacities of a newly developed Upflow filtration device for treatment of stormwater. The device was developed by engineers at the University of Alabama through a Small Business Innovative Research (SBIR) grant from the U....

Time- and cost-saving apparatus for analytical sample filtration

Treesearch

William R. Kenealy; Joseph C. Destree

2005-01-01

Simple and cost-effective protocols were developed for removing particulates from samples prior to analysis by high performance liquid chromatography and gas chromatography. A filter and vial holder were developed for use with a 96-well filtration plate. The device saves preparation time and costs.

A neutral mannan from Ceratocystis fagacearum culture filtrate

Treesearch

P. McWain; G.F. Gregory

1972-01-01

The culture filtrate of Ceratocystis fagacearum contains a mannan that produces some symptoms similar to oak wilt in red oak seedlings and cuttings. The mannan has a high molecular weight and a skeleton of α- (1 → 6) linked mannose units with considerable branching. Some similarities to commercial yeast mannan have been observed.

Spectral imaging perspective on cytomics.

PubMed

Levenson, Richard M

2006-07-01

Cytomics involves the analysis of cellular morphology and molecular phenotypes, with reference to tissue architecture and to additional metadata. To this end, a variety of imaging and nonimaging technologies need to be integrated. Spectral imaging is proposed as a tool that can simplify and enrich the extraction of morphological and molecular information. Simple-to-use instrumentation is available that mounts on standard microscopes and can generate spectral image datasets with excellent spatial and spectral resolution; these can be exploited by sophisticated analysis tools. This report focuses on brightfield microscopy-based approaches. Cytological and histological samples were stained using nonspecific standard stains (Giemsa; hematoxylin and eosin (H&E)) or immunohistochemical (IHC) techniques employing three chromogens plus a hematoxylin counterstain. The samples were imaged using the Nuance system, a commercially available, liquid-crystal tunable-filter-based multispectral imaging platform. The resulting data sets were analyzed using spectral unmixing algorithms and/or learn-by-example classification tools. Spectral unmixing of Giemsa-stained guinea-pig blood films readily classified the major blood elements. Machine-learning classifiers were also successful at the same task, as well in distinguishing normal from malignant regions in a colon-cancer example, and in delineating regions of inflammation in an H&E-stained kidney sample. In an example of a multiplexed ICH sample, brown, red, and blue chromogens were isolated into separate images without crosstalk or interference from the (also blue) hematoxylin counterstain. Cytomics requires both accurate architectural segmentation as well as multiplexed molecular imaging to associate molecular phenotypes with relevant cellular and tissue compartments. Multispectral imaging can assist in both these tasks, and conveys new utility to brightfield-based microscopy approaches. Copyright 2006 International Society for

Comparison Study of Regularizations in Spectral Computed Tomography Reconstruction

NASA Astrophysics Data System (ADS)

Salehjahromi, Morteza; Zhang, Yanbo; Yu, Hengyong

2018-12-01

The energy-resolving photon-counting detectors in spectral computed tomography (CT) can acquire projections of an object in different energy channels. In other words, they are able to reliably distinguish the received photon energies. These detectors lead to the emerging spectral CT, which is also called multi-energy CT, energy-selective CT, color CT, etc. Spectral CT can provide additional information in comparison with the conventional CT in which energy integrating detectors are used to acquire polychromatic projections of an object being investigated. The measurements obtained by X-ray CT detectors are noisy in reality, especially in spectral CT where the photon number is low in each energy channel. Therefore, some regularization should be applied to obtain a better image quality for this ill-posed problem in spectral CT image reconstruction. Quadratic-based regularizations are not often satisfactory as they blur the edges in the reconstructed images. As a result, different edge-preserving regularization methods have been adopted for reconstructing high quality images in the last decade. In this work, we numerically evaluate the performance of different regularizers in spectral CT, including total variation, non-local means and anisotropic diffusion. The goal is to provide some practical guidance to accurately reconstruct the attenuation distribution in each energy channel of the spectral CT data.

Validation of the Glaucoma Filtration Surgical Mouse Model for Antifibrotic Drug Evaluation

PubMed Central

Seet, Li-Fong; Lee, Wing Sum; Su, Roseline; Finger, Sharon N; Crowston, Jonathan G; Wong, Tina T

2011-01-01

Glaucoma is a progressive optic neuropathy, which, if left untreated, leads to blindness. The most common and most modifiable risk factor in glaucoma is elevated intraocular pressure (IOP), which can be managed surgically by filtration surgery. The postoperative subconjunctival scarring response, however, remains the major obstacle to achieving long-term surgical success. Antiproliferatives such as mitomycin C are commonly used to prevent postoperative scarring. Efficacy of these agents has been tested extensively on monkey and rabbit models of glaucoma filtration surgery. As these models have inherent limitations, we have developed a model of glaucoma filtration surgery in the mouse. We show, for the first time, that the mouse model typically scarred within 14 d, but when augmented with mitomycin C, more animals maintained lower intraocular pressures for a longer period of time concomitant with prolonged bleb survival to beyond 28 d. The morphology of the blebs following mitomycin C treatment also resembled well-documented clinical observations, thus confirming the validity and clinical relevance of this model. We demonstrate that the antiscarring response to mitomycin C is likely to be due to its effects on conjunctival fibroblast proliferation, apoptosis and collagen deposition and the suppression of inflammation. Indeed, we verified some of these properties on mouse conjunctival fibroblasts cultured in vitro. These data support the suitability of this mouse model for studying the wound healing response in glaucoma filtration surgery, and as a potentially useful tool for the in vivo evaluation of antifibrotic therapeutics in the eye. PMID:21229189

Spectral evolution of GRBs with negative spectral lag using Fermi GBM observations

NASA Astrophysics Data System (ADS)

Chakrabarti, Arundhati; Chaudhury, Kishor; Sarkar, Samir K.; Bhadra, Arunava

2018-06-01

The positive spectral lag of Gamma Ray Bursts (GRBs) is often explained in terms of hard-to-soft spectral evolution of GRB pulses. While positive lags of GRBs is very common, there are few GRB pulses that exhibits negative spectral lags. In the present work we examine whether negative lags of GRBs also can be interpreted in terms of spectral evolution of GRB pulses or not. Using Fermi-GBM data, we identify two GRBs, GRB 090426C and GRB 150213A, with clean pulses that exhibit negative spectral lag. An indication of soft to hard transition has been noticed for the negative spectral lag events from the spectral evolution study. The implication of the present findings on the models of GRB spectral lags are discussed.

Identifying, counting, and characterizing superfine activated-carbon particles remaining after coagulation, sedimentation, and sand filtration.

PubMed

Nakazawa, Yoshifumi; Matsui, Yoshihiko; Hanamura, Yusuke; Shinno, Koki; Shirasaki, Nobutaka; Matsushita, Taku

2018-07-01

Superfine powdered activated carbon (SPAC; particle diameter ∼1 μm) has greater adsorptivity for organic molecules than conventionally sized powdered activated carbon (PAC). Although SPAC is currently used in the pretreatment to membrane filtration at drinking water purification plants, it is not used in conventional water treatment consisting of coagulation-flocculation, sedimentation, and rapid sand filtration (CSF), because it is unclear whether CSF can adequately remove SPAC from the water. In this study, we therefore investigated the residual SPAC particles in water after CSF treatment. First, we developed a method to detect and quantify trace concentration of carbon particles in the sand filtrate. This method consisted of 1) sampling particles with a membrane filter and then 2) using image analysis software to manipulate a photomicrograph of the filter so that black spots with a diameter >0.2 μm (considered to be carbon particles) could be visualized. Use of this method revealed that CSF removed a very high percentage of SPAC: approximately 5-log in terms of particle number concentrations and approximately 6-log in terms of particle volume concentrations. When waters containing 7.5-mg/L SPAC and 30-mg/L PAC, concentrations that achieved the same adsorption performance, were treated, the removal rate of SPAC was somewhat superior to that of PAC, and the residual particle number concentrations for SPAC and PAC were at the same low level (100-200 particles/mL). Together, these results suggest that SPAC can be used in place of PAC in CSF treatment without compromising the quality of the filtered water in terms of particulate matter contamination. However, it should be noted that the activated carbon particles after sand filtration were smaller in terms of particle size and were charge-neutralized to a lesser extent than the activated carbon particles before sand filtration. Therefore, the tendency of small particles to escape in the filtrate would appear

Diatomite filtration of water for injection

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

Olmsted, B.C. Jr.; Bell, G.R.

1966-01-01

A discussion is presented of the capabilities, problems, and answers, in the performance of diatomite filters. The discussion includes a description of diatomite filtration, new developments, design criteria, and some case histories. Diatomite filters, when properly designed and installed, and when properly applied, can provide effective clarification of waters for injection at low capital and operating costs. Design, installation, and proper application, effectiveness, and capital and operating costs can be placed in the proper perspective in the light of general experience and recent pilot plant tests in the southern California area. (30 refs.)

Effect of flood-induced chemical load on filtrate quality at bank filtration sites

USGS Publications Warehouse

Ray, C.; Soong, T.W.; Lian, Y.Q.; Roadcap, G.S.

2002-01-01

Riparian municipal wells, that are located on riverbanks, are specifically designed to capture a portion of the river water through induced infiltration. Runoff from agricultural watersheds is found to carry enormous amounts of pesticides and nitrate. While the risk of contamination for a vast majority of sites with small-capacity vertical wells is low, potential exists for medium to large capacity collector wells to capture a fraction of the surface water contaminants during flood. Prior monitoring and current modeling results indicate that a small-capacity (peak pumpage 0.0315 m3/s) vertical bank filtration well may not be affected by river water nitrate and atrazine even during flood periods. For a medium capacity (0.0875-0.175 m3/s) hypothetical collector well at the same site, potential exists for a portion of the river water nitrate and atrazine to enter the well during flood periods. Various combinations of hydraulic conductivity of the riverbed or bank material were used. For nitrate, it was assumed either no denitrification occurred during the period of simulation or a half-life of 2 years. Equilibrium controlled sorption (organic carbon partition coefficient of 52 ml/g) and a half-life of between 7.5 and 15 weeks were considered for atrazine. Combinations of these parameters were used in various simulations. Peak concentrations of atrazine or nitrate in pumped water could vary from less than 1% to as high as 90% of that in the river. It was found that a combination of river stage, pumping rates, hydraulic properties of the riverbed and bank, and soil/pesticide properties could affect contaminant entry from river water to any of these wells. If the hydraulic conductivity of the bed and bank material were low, atrazine would not reach the pumping well with or without sorption and degradation. However, for moderately low permeable bank and bed materials, some atrazine from river water could enter a hypothetical collector well while pumping at 0.0875 m3/s. It

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

PubMed Central

Rashid, Md. Harun-Or; Ralph, Stephen F.

2017-01-01

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. PMID:28468314

Formation of siliceous sediments in brandy after diatomite filtration.

PubMed

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

2015-03-01

Brandy is quite a stable spirit but sometimes light sediment appears. This sediment was separated and analysed by IR and SEM-EDX. It was revealed that the sediment is composed mostly of silica and residual organic matter. Silica was present as an amorphous phase and as microparticles. In an attempt to reproduce the formation of the sediment, a diatomite extract was prepared with an ethanol/water mixture (36% vol.) and a calcined diatomite similar to that used in brandy filtration. This extract was added to unfiltered brandy in different amounts. After 1 month, the Si concentration decreased in all samples and sediments with similar compositions and features to those found in the unstable brandy appeared. The amounts of sediment obtained were directly related to the decrease in Si concentration in solution. Consequently, it can be concluded that siliceous sediment in brandy originates from Si released during diatomite filtration. Copyright © 2014 Elsevier Ltd. All rights reserved.

1. VIEW OF THE WATER FILTRATION PLANT FROM THE ACCESS ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

1. VIEW OF THE WATER FILTRATION PLANT FROM THE ACCESS ROAD, LOOKING NORTHWEST. - Tower Hill No. 2 Mine, Approximately 0.47 mile Southwest of intersection of Stone Church Road & Township Route 561, Hibbs, Fayette County, PA

Host-specific effects of soil microbial filtrates prevail over those of arbuscular mycorrhizae in a fragmented landscape.

PubMed

Pizano, Camila; Mangan, Scott A; Graham, James H; Kitajima, Kaoru

2017-09-01

Plant-soil interactions have been shown to determine plant community composition in a wide range of environments. However, how plants distinctly interact with beneficial and detrimental organisms across mosaic landscapes containing fragmented habitats is still poorly understood. We experimentally tested feedback responses between plants and soil microbial communities from adjacent habitats across a disturbance gradient within a human-modified tropical montane landscape. In a greenhouse experiment, two components of soil microbial communities were amplified; arbuscular mycorrhizal fungi (AMF) and a filtrate excluding AMF spores from the soils of pastures (high disturbance), coffee plantations (intermediate disturbance), and forest fragments (low disturbance), using potted seedlings of 11 plant species common in these habitats (pasture grass, coffee, and nine native species). We then examined their effects on growth of these same 11 host species with reciprocal habitat inoculation. Most plant species received a similar benefit from AMF, but differed in their response to the filtrates from the three habitats. Soil filtrate from pastures had a net negative effect on plant growth, while filtrates from coffee plantations and forests had a net positive effect on plant growth. Pasture grass, coffee, and five pioneer tree species performed better with the filtrate from "away" (where these species rarely occur) compared to "home" (where these species typically occur) habitat soils, while four shade-tolerant tree species grew similarly with filtrates from different habitats. These results suggest that pastures accumulate species-specific soil enemies, while coffee plantations and forests accumulate beneficial soil microbes that benefit pioneer native plants and coffee, respectively. Thus, compared to AMF, soil filtrates exerted stronger habitat and host-specific effects on plants, being more important mediators of plant-soil feedbacks across contrasting habitats. © 2017 by

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

PubMed

Singer, B C; Delp, W W; Black, D R; Walker, I S

2017-07-01

This study evaluated nine ventilation and filtration systems in an unoccupied 2006 house located 250 m 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 provided 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 2.5 by 97-98% relative to outdoors. Supply filtration systems used little energy but provided no benefits for indoor-generated particles. Systems with MERV13-16 filter 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. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

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

DOE PAGES

Singer, B. C.; Delp, W. W.; Black, D. R.; ...

2016-12-05

This study evaluated nine ventilation and filtration systems in an unoccupied 2006 house located 250 m 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 provided 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 2.5 by 97-98% relative to outdoors. Supply filtration systems usedmore » little energy but provided no benefits for indoor-generated particles. Systems with MERV13-16 fil ter 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.« less

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

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

Singer, Brett C.; Delp, William W.; Black, Douglas R.

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 usedmore » 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.« less

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

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

Singer, B. C.; Delp, W. W.; Black, D. R.

This study evaluated nine ventilation and filtration systems in an unoccupied 2006 house located 250 m 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 provided 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 2.5 by 97-98% relative to outdoors. Supply filtration systems usedmore » little energy but provided no benefits for indoor-generated particles. Systems with MERV13-16 fil ter 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.« less

Epidemiological study of air filtration systems for preventing PRRSV infection in large sow herds.

PubMed

Alonso, Carmen; Murtaugh, Michael P; Dee, Scott A; Davies, Peter R

2013-10-01

Porcine reproductive and respiratory syndrome virus (PRRSV) is the most economically significant pathogen in the US swine industry. Aerosol transmission among herds is a major concern in pig dense regions and filtration of incoming air, in combination with standard biosecurity procedures, has been demonstrated to prevent transmission of PRRSV into susceptible herds. To quantify the impact of air filtration on reducing risk of PRRSV outbreaks, we compared the incidence rate of new PRRSV introductions in 20 filtered and 17 non-filtered control sow herds in a swine dense region of North America during a 7 year study period. Events of novel virus introduction were ascertained by phylogenetic analysis of PRRSV ORF5 gene sequences. Putative new viruses were defined as exogenous (introduced) based on ORF5 nucleotide sequence differences compared to previous farm isolates. The influence of sequence difference cut-off values ranging from 2 to 10% on case definition and relative risk were evaluated. Non-filtered farms incurred about 0.5 outbreaks per year, with a seasonal increase in risk in cooler periods. Baseline risk, prior to filtration, in treatment farms was approximately 0.75 per year, approximately 50% higher than in control farms. Air filtration significantly reduced risk of PRRSV introduction events to 0.06-0.22 outbreaks per year, depending on the cut-off values used to classify a virus isolate as new to the herd. Overall, air filtration led to an approximately 80% reduction in risk of introduction of novel PRRSV, indicating that on large sow farms with good biosecurity in swine-dense regions, approximately four-fifths of PRRSV outbreaks may be attributable to aerosol transmission. Copyright © 2013 Elsevier B.V. All rights reserved.

Tangential Flow Filtration of Hemoglobin

PubMed Central

Sun, Guoyong; Harris, David R.

2009-01-01

Bovine and human hemoglobin (bHb and hHb, respectively) was purified from bovine and human red blood cells (bRBCs and hRBCs, respectively) via tangential flow filtration (TFF) in four successive stages. TFF is a fast and simple method to purify Hb from RBCs using filtration through hollow fiber (HF) membranes. Most of the Hb was retained in stage III (100 kDa HF membrane) and displayed methemoglobin levels less than 1%, yielding final concentrations of 318 and 300 mg/mL for bHb and hHb, respectively. Purified Hb exhibited much lower endotoxin levels than their respective RBCs. The purity of Hb was initially assessed via SDS-PAGE, and showed tiny impurity bands for the stage III retentate. The oxygen affinity (P50), and cooperativity coefficient (n) were regressed from the measured oxygen-RBC/Hb equilibrium curves of RBCs and purified Hb. These results suggest that TFF yielded oxygen affinities of bHb and hHb that are comparable to values in the literature. LC-MS was used to measure the molecular weight of the alpha (α) and beta (β) globin chains of purified Hb. No impurity peaks were present in the HPLC chromatograms of purified Hb. The mass of the molecular ions corresponding to the α and β globin chains agreed well with the calculated theoretical mass of the α-and β-globin chains. Taken together, our results demonstrate that HPLC grade Hb can be generated via TFF. In general, this method can be more broadly applied to purify Hb from any source of RBCs. This work is significant, since it outlines a simple method for generating Hb for synthesis and/or formulation of Hb-based oxygen carriers (HBOCs). PMID:19224583

Nanocarbon-based membrane filtration integrated with electric field driving for effective membrane fouling mitigation.

PubMed

Fan, Xinfei; Zhao, Huimin; Quan, Xie; Liu, Yanming; Chen, Shuo

2016-01-01

Membrane filtration provides an effective solution for removing pollutants from water but is limited by serious membrane fouling. In this work, an effective approach was used to mitigate membrane fouling by integrating membrane filtration with electropolarization using an electroconductive nanocarbon-based membrane. The electropolarized membrane (EM) by alternating square-wave potentials between +1.0 V and -1.0 V with a pulse width of 60 s exhibited a permeate flux 8.1 times as high as that without electropolarization for filtering feed water containing bacteria, which confirms the ability of the EM to achieve biofouling mitigation. Moreover, the permeate flux of EM was 1.5 times as high as that without electropolarization when filtrating natural organic matter (NOM) from water, and demonstrated good performance in organic fouling mitigation with EM. Furthermore, the EM was also effective for complex fouling mitigation in filtering water containing coexisting bacteria and NOM, and presented an increased flux rate 1.9 times as high as that without electropolarization. The superior fouling mitigation performance of EM was attributed to the synergistic effects of electrostatic repulsion, electrochemical oxidation and electrokinetic behaviors. This work opens an effective avenue for membrane fouling mitigation of water-treatment membrane filtration systems. Copyright © 2015 Elsevier Ltd. All rights reserved.

The Effectiveness of Permanent Highway Runoff Controls: Sedimentation/Filtration Systems

DOT National Transportation Integrated Search

1998-09-01

Original Report Date: October 1997. This study evaluates the performance of sedimentation/filtration systems that are the most common control for treating highway runoff in the Edwards Aquifer recharge zone. The study includes: 1) monitoring and eval...

Evaluation of Filtration and UV Disinfection for Inactivation of Viruses in Non-Community Water Systems in Minnesota

EPA Science Inventory

This study evaluated filtration and disinfection processes for removal and inactivation of pathogens in non-community water systems (NCWS) in two surface water supplies. Pretreatment systems included 1) pressure sand filtration, and 2) granular activated carbon adsorption, and 3...

Experimental and Numerical Study of Ceramic Foam Filtration

NASA Astrophysics Data System (ADS)

Laé, E.; Duval, H.; Rivière, C.; Le Brun, P.; Guillot, J.-B.

Ceramic foam filtration is widely used to enable removal of non metallic inclusions from liquid aluminium. Its performances have been largely studied in the literature and some discrepancies remain amongst the published results. Consequently, a research program was deployed to evaluate the performances of a range of ceramic foam filters used under various conditions and to understand the inclusions capture mechanisms.

Dissemination, resuspension, and filtration of carbon fibers. [aircraft fires

NASA Technical Reports Server (NTRS)

Elber, W.

1980-01-01

Carbon fiber transport was studied using mathematical models established for other pollution problems. It was demonstrated that resuspension is not a major factor contributing to the risk. Filtration and fragmentation tests revealed that fiber fragmentation shifts the fiber spectrum to shorter mean lengths in high velocity air handling systems.

Engineering of an MBR supernatant fouling layer by fine particles addition: a possible way to control cake compressibility.

PubMed

Teychene, Benoît; Guigui, Christelle; Cabassud, Corinne

2011-02-01

For membrane bioreactors (MBR) applied to wastewater treatment membrane fouling is still the prevalent issue. The main limiting phenomena related to fouling is a sudden jump of the transmembrane pressure (TMP) often attributed to the collapse of the fouling layer. Among existing techniques to avoid or to delay this collapse, the addition of active particles membrane fouling reducers (polymer, resins, powdered activated carbon (PAC), zeolithe...) showed promising results. Thus the main objective of this work is to determine if fouling can be reduced by inclusion of inert particles (500 nm and inert compared to other fouling reducers) and which is the impact on filtration performances of the structuring of the fouling. Those particles were chosen for their different surface properties and their capability to form well structured layer. Results, obtained at constant pressure in dead end mode, show that the presence of particles changes foulant deposition and induces non-compressible fouling (in the range of 0.5-1 bar) and higher rejection values compared to filtration done on supernatant alone. Indeed dead end filtration tests show that whatever interactions between biofluid and particles, the addition of particles leads to better filtration performances (in terms of rejection, and fouling layer compressibility). Moreover results confirm the important role played by macromolecular compounds, during supernatant filtration, creating highly compressible and reversible fouling. In conclusion, this study done at lab-scale suggests the potential benefit to engineer fouling structure to control or to delay the collapse of the fouling layer. Finally this study offers the opportunities to enlarge the choice of membrane fouling reducers by taking into consideration their ability to form more consistent fouling (i.e. rigid, structured fouling). Copyright © 2010 Elsevier Ltd. All rights reserved.

Effect of operation parameters on the flux stabilization of gravity-driven membrane (GDM) filtration system for decentralized water supply.

PubMed

Tang, Xiaobin; Ding, An; Qu, Fangshu; Jia, Ruibao; Chang, Haiqing; Cheng, Xiaoxiang; Liu, Bin; Li, Guibai; Liang, Heng

2016-08-01

A pilot-scale gravity-driven membrane (GDM) filtration system under low gravitational pressure without any pre-treatment, backwash, flushing, or chemical cleaning was carried out to investigate the effect of operation parameters (including operation pressure, aeration mode, and intermittent filtration) on the effluent quality and permeability development. The results revealed that GDM system exhibited an efficient performance for the removal of suspended substances and organic compounds. The stabilization of flux occurred and the average values of stable flux were 6.6, 8.1, and 8.6 Lm(-2) h(-1) for pressures of 65, 120, and 200 mbar, respectively. In contrast, flux stabilization was not observed under continuous and intermittent aeration conditions. However, aeration (especially continuous aeration) was effective to improve flux and alleviate membrane fouling during 1-month operation. Moreover, intermittent filtration would influence the stabilization of permeate flux, resulting in a higher stable flux (ranging from 6 to 13 Lm(-2) h(-1)). The stable flux significantly improved with the increase of intermittent period. Additionally, GDM systems exhibited an efficient recovery of flux after simple physical cleaning and the analyses of resistance reversibility demonstrated that most of the total resistance was hydraulic reversible resistance (50-75 %). Therefore, it is expected that the results of this study can develop strategies to increase membrane permeability and reduce energy consumption in GDM systems for decentralized water supply.

Filtration stability of living brush mattresses at navigable waterways

NASA Astrophysics Data System (ADS)

Sokopp, Manuel

2017-04-01

According to the guidelines of the Federal Waterways Engineering and Research Institute in Germany, waterway construction buildings, which include soil bioengineering structures, must be stable against soil displacements. Therefore, willow brush mattresses were tested for their filtration stability in a specially developed process which is based on the testing of geotextiles and armourstones used for navigable waterway constructions. In March 2016 willow brush mattresses made of white (Salix alba L.) or basket willows (Salix viminalis L.) were planted in 16 sample boxes, each with a cross-section area of 30x30 cm. For the tests on filtration stability, the upper 20 cm of the box were separated and placed upside down into a device in which the sample box could be flowed through from below. When a water column of 50 cm above the sample was reached, the water outlet was opened so the water flowed through the sample in the opposite direction, thus simulating drawdown. By the measurements of the pressure sensors above and below the sample, the coefficient of permeability k of the rooted soil during drawdown could be calculated. After this hydropeaking cycle, the soil material that was rinsed out through the willow branches was collected, weighed after drying until weight constancy, and compared with the dry mass of the retained soil material to calculate the share of the total mass. These filtration stability tests were carried out directly after planting the sample boxes, as well as one, three and six months afterwards, each test series with four reruns per willow species. Over time, the increasing root penetration resulted in a significant reduction in the permeability and in more retained soil material.

Influence of thyroid function on glomerular filtration rate and other estimates of kidney function in two pediatric patients.

PubMed

Uemura, Osamu; Iwata, Naoyuki; Nagai, Takuhito; Yamakawa, Satoshi; Hibino, Satoshi; Yamamoto, Masaki; Nakano, Masaru; Tanaka, Kazuki

2018-05-01

To determine the optimal method of evaluating kidney function in patients with thyroid dysfunction, this study compared the estimated glomerular filtration rate derived from serum creatinine, cystatin C, or β2-microglobulin with inulin or creatinine clearance in two pediatric patients, one with hypothyroidism and the other with hyperthyroidism. It was observed that the kidney function decreased in a hypothyroid child and enhanced in a hyperthyroid child, with their kidney function becoming normalized by treatment with drugs, which normalized their thyroid function. Kidney function cannot be accurately evaluated using cystatin C-based or β2-microglobulin-based estimated glomerular filtration rate in patients with thyroid dysfunction, as these tests overestimated glomerular filtration rate in a patient with hypothyroidism and underestimated glomerular filtration rate in a patient with hyperthyroidism, perhaps through a metabolic rate-mediated mechanism. In both our patients, 24-h urinary creatinine secretion was identical before and after treatment, suggesting that creatinine production is not altered in patients with thyroid dysfunction. Therefore, kidney function in patients with thyroid dysfunction should be evaluated using creatinine-based estimated glomerular filtration rate.

Automation of water supply and recirculation-filtration of water at a swimming pool using Zelio PLC

NASA Astrophysics Data System (ADS)

Diniş, C. M.; Popa, G. N.; Iagăr, A.

2018-01-01

The paper proposes the use of the Zelio PLC for the automation of the water supply and recirculation-filtration system of a swimming pool. To do this, the Zelio SR3B261BD - 24V DC with 10 digital inputs (24V DC) and 10 digital outputs (relay contacts) was used. The proposed application makes the control of the water supply pumps and the water recirculation-filtration from a swimming pool. The recirculation-filtration systems for pools and swimming pools are designed to ensure water cleaning and recirculation to achieve optimum quality and lasting service life. The water filtration process is one of the important steps in water treatment in polls and swimming pools. It consists in recirculation of the entire volume of water and begins by absorbing the water in the pool by means of a pump followed by the passing of water through the filter, disinfectant and pH dosing, and reintroducing the water back into the pool or swimming pool through the discharge holes. Filters must to work 24 hours a day to remove pollutants from pools or swimming pools users. Filtration removes suspension particles with different origins. All newly built pools and swimming pools must be fitted with water recirculation systems, and existing ones will be equipped with water recirculation and water treatment systems.

Direct separation of arsenic and antimony oxides by high-temperature filtration with porous FeAl intermetallic.

PubMed

Zhang, Huibin; Liu, Xinli; Jiang, Yao; Gao, Lin; Yu, Linping; Lin, Nan; He, Yuehui; Liu, C T

2017-09-15

A temperature-controlled selective filtration technology for synchronous removal of arsenic and recovery of antimony from the fume produced from reduction smelting process of lead anode slimes was proposed. The chromium (Cr) alloyed FeAl intermetallic with an asymmetric pore structure was developed as the high-temperature filter material after evaluating its corrosive resistance, structural stability and mechanical properties. The results showed that porous FeAl alloyed with 20wt.% Cr had a long term stability in a high-temperature sulfide-bearing environment. The separation of arsenic and antimony trioxides was realized principally based on their disparate saturated vapor pressures at specific temperature ranges and the asymmetric membrane of FeAl filter elements with a mean pore size of 1.8μm. Pilot-scale filtration tests showed that the direct separation of arsenic and antimony can be achieved by a one-step or two-step filtration process. A higher removal percentage of arsenic can reach 92.24% at the expense of 6∼7% loss of antimony in the two-step filtration process at 500∼550°C and 300∼400°C. The FeAl filters had still good permeable and mechanical properties with 1041h of uninterrupted service, which indicates the feasibility of this high-temperature filtration technology. Copyright © 2017. Published by Elsevier B.V.

Spectral imaging toolbox: segmentation, hyperstack reconstruction, and batch processing of spectral images for the determination of cell and model membrane lipid order.

PubMed

Aron, Miles; Browning, Richard; Carugo, Dario; Sezgin, Erdinc; Bernardino de la Serna, Jorge; Eggeling, Christian; Stride, Eleanor

2017-05-12

Spectral imaging with polarity-sensitive fluorescent probes enables the quantification of cell and model membrane physical properties, including local hydration, fluidity, and lateral lipid packing, usually characterized by the generalized polarization (GP) parameter. With the development of commercial microscopes equipped with spectral detectors, spectral imaging has become a convenient and powerful technique for measuring GP and other membrane properties. The existing tools for spectral image processing, however, are insufficient for processing the large data sets afforded by this technological advancement, and are unsuitable for processing images acquired with rapidly internalized fluorescent probes. Here we present a MATLAB spectral imaging toolbox with the aim of overcoming these limitations. In addition to common operations, such as the calculation of distributions of GP values, generation of pseudo-colored GP maps, and spectral analysis, a key highlight of this tool is reliable membrane segmentation for probes that are rapidly internalized. Furthermore, handling for hyperstacks, 3D reconstruction and batch processing facilitates analysis of data sets generated by time series, z-stack, and area scan microscope operations. Finally, the object size distribution is determined, which can provide insight into the mechanisms underlying changes in membrane properties and is desirable for e.g. studies involving model membranes and surfactant coated particles. Analysis is demonstrated for cell membranes, cell-derived vesicles, model membranes, and microbubbles with environmentally-sensitive probes Laurdan, carboxyl-modified Laurdan (C-Laurdan), Di-4-ANEPPDHQ, and Di-4-AN(F)EPPTEA (FE), for quantification of the local lateral density of lipids or lipid packing. The Spectral Imaging Toolbox is a powerful tool for the segmentation and processing of large spectral imaging datasets with a reliable method for membrane segmentation and no ability in programming required. The

Spectral signature verification using statistical analysis and text mining

NASA Astrophysics Data System (ADS)

DeCoster, Mallory E.; Firpi, Alexe H.; Jacobs, Samantha K.; Cone, Shelli R.; Tzeng, Nigel H.; Rodriguez, Benjamin M.

2016-05-01

In the spectral science community, numerous spectral signatures are stored in databases representative of many sample materials collected from a variety of spectrometers and spectroscopists. Due to the variety and variability of the spectra that comprise many spectral databases, it is necessary to establish a metric for validating the quality of spectral signatures. This has been an area of great discussion and debate in the spectral science community. This paper discusses a method that independently validates two different aspects of a spectral signature to arrive at a final qualitative assessment; the textual meta-data and numerical spectral data. Results associated with the spectral data stored in the Signature Database1 (SigDB) are proposed. The numerical data comprising a sample material's spectrum is validated based on statistical properties derived from an ideal population set. The quality of the test spectrum is ranked based on a spectral angle mapper (SAM) comparison to the mean spectrum derived from the population set. Additionally, the contextual data of a test spectrum is qualitatively analyzed using lexical analysis text mining. This technique analyzes to understand the syntax of the meta-data to provide local learning patterns and trends within the spectral data, indicative of the test spectrum's quality. Text mining applications have successfully been implemented for security2 (text encryption/decryption), biomedical3 , and marketing4 applications. The text mining lexical analysis algorithm is trained on the meta-data patterns of a subset of high and low quality spectra, in order to have a model to apply to the entire SigDB data set. The statistical and textual methods combine to assess the quality of a test spectrum existing in a database without the need of an expert user. This method has been compared to other validation methods accepted by the spectral science community, and has provided promising results when a baseline spectral signature is

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

PubMed

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.

Use of colloid filtration theory in modeling movement of bacteria through a contaminated sandy aquifer

USGS Publications Warehouse

Harvey, R.W.; Garabedian, S.P.

1991-01-01

??? A filtration model commonly used to describe removal of colloids during packed-bed filtration in water treatment applications was modified for describing downgradient transport of bacteria in sandy, aquifer sediments. The modified model was applied to the results of a small-scale (7 m), natural-gradient tracer test and to observations of an indigenous bacterial population moving downgradient within a plume of organically contaminated groundwater in Cape Cod, MA. The model reasonably accounted for concentration histories of labeled bacteria appearing at samplers downgradient from the injection well in the tracer experiment and for the observed 0.25-??m increase in average cell length for an unlabeled, indigenous bacterial population, 0.6 km downgradient from the source of the plume. Several uncertainties were apparent in applying filtration theory to problems involving transport of bacteria in groundwater. However, adsorption (attachment) appeared to be a major control of the extent of bacterial movement downgradient, which could be described, in part, by filtration theory. Estimates of the collision efficiency factor, which represents the physicochemical factors that determine adsorption of the bacteria onto the grain surfaces, ranged from 5.4 ?? 10-3 to 9.7 ?? 10-3.

Circadian Rhythm of Glomerular Filtration and Solute Handling Related to Nocturnal Enuresis.

PubMed

Dossche, L; Raes, A; Hoebeke, P; De Bruyne, P; Vande Walle, J

2016-01-01

Although nocturnal polyuria in patients with monosymptomatic enuresis can largely be explained by the decreased nocturnal vasopressin secretion hypothesis, other circadian rhythms in the kidney also seem to have a role. We recently documented an absent day/night rhythm in a subgroup of desmopressin refractory cases. We explore the importance of abnormal circadian rhythm of glomerular filtration and tubular (sodium, potassium) parameters in patients with monosymptomatic enuresis. In this retrospective study of a tertiary enuresis population we collected data subsequent to a standardized screening (International Children's Continence Society questionnaire), 14-day diary for nocturnal enuresis and diuresis, and 24-hour concentration profile. The study population consisted of 139 children with nocturnal enuresis who were 5 years or older. Children with nonmonosymptomatic nocturnal enuresis were used as controls. There was a maintained circadian rhythm of glomerular filtration, sodium, osmotic excretion and diuresis rate in children with monosymptomatic and nonmonosymptomatic nocturnal enuresis, and there was no difference between the 2 groups. Secondary analysis revealed that in patients with nocturnal polyuria (with monosymptomatic or nonmonosymptomatic nocturnal enuresis) circadian rhythm of glomerular filtration, sodium and osmotic excretion, and diuresis rate was diminished in contrast to those without nocturnal polyuria (p <0.001). Circadian rhythm of the kidney does not differ between patients with nonmonosymptomatic and monosymptomatic enuresis. However, the subgroup with enuresis and nocturnal polyuria has a diminished circadian rhythm of nocturnal diuresis, sodium excretion and glomerular filtration in contrast to children without nocturnal polyuria. This observation cannot be explained by the vasopressin theory alone. Copyright © 2016 American Urological Association Education and Research, Inc. Published by Elsevier Inc. All rights reserved.

Production of a ruminant protein supplement by anaerobic fermentation of feedlot waste filtrate

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

Reddy, C.A.; Erdman, M.D.

1977-01-01

In studies initiated to develop simple and efficient procedures for the production of feed supplements, it was shown that the filtrate from feedlot wastes diluted with water and filtered could be fermented under anaerobic conditions by mixed rumen bacteria, Lactobacilli, or natural microflora from the feedlot wastes to produce a protein-rich feed supplement. The filtrate is low in carbohydrate and therefore supplemental carbohydrate in the form of whey, molasses, starch from potato processing wastes, or corn starch is necessary. Rigid anaerobic conditions need not be maintained nor must aseptic conditions be observed. (JSR)

Membrane morphology and topology for fouling control in Reverse Osmosis filtration systems

NASA Astrophysics Data System (ADS)

Ling, Bowen; Battiato, Ilenia

2017-11-01

Reverse Osmosis Membrane (ROM) filtration systems are widely utilized in waste-water recovery, seawater desalination, landfill water treatment, etc. During filtration, the system performance is dramatically affected by membrane fouling which causes a significant decrease in permeate flux as well as an increase in the energy input required to operate the system. Design and optimization of ROM filtration systems aim at reducing membrane fouling by studying the coupling between membrane structure, local flow field and foulant adsorption patterns. Yet, current studies focus exclusively on oversimplified steady-state models that ignore any dynamic coupling between fluid flow and transport through the membrane. In this work, we develop a customized solver (SUMembraneFoam) under OpenFOAM to solve the transient equations. The simulation results not only predict macroscopic quantities (e.g. permeate flux, pressure drop, etc.) but also show an excellent agreement with the fouling patterns observed in experiments. It is observed that foulant deposition is strongly controlled by the local shear stress on the membrane, and channel morphology or membrane topology can be modified to control the shear stress distribution and reduce fouling. Finally, we identify optimal regimes for design.

Infrared Spectral Observations While Drilling into a Frozen Lunar Simulant

NASA Technical Reports Server (NTRS)

Roush, Ted L.; Colaprete, Anthony; Thompson, Sarah; Cook, Amanda; Kleinhenz, Julie

2014-01-01

Past and continuing observations indicate an enrichment of volatile materials in lunar polar regions. While these volatiles may be located near the surface, access to them will likely require subsurface sampling, during which it is desirable to monitor the volatile content. In a simulation of such activities, a multilayer lunar simulant was prepared with differing water content, and placed inside a thermal vacuum chamber at Glenn Research Center (GRC). The soil profile was cooled using liquid nitrogen. In addition to the soil, a drill and infrared (IR) spectrometer (1600-3400 nm) were also located in the GRC chamber. We report the spectral observations obtained during a sequence where the drill was repeatedly inserted and extracted, to different depths, at the same location. We observe an overall increase in the spectral signature of water ice over the duration of the test. Additionally, we observe variations in the water ice spectral signature as the drill encounters different layers.

EVALUATION OF FILTRATION AND DISTILLATION METHODS FOR RECYCLING AUTOMOTIVE COOLANT.

EPA Science Inventory

This evaluation addresses the product quality, waste reduction, and economic issues involved in recycling automotive and heavy-duty engine coolants at a New Jersey Department of Transportation garage. The specific recycling units evaluated are based on the technologies of filtrat...

Temporal intensity interferometry for characterization of very narrow spectral lines

NASA Astrophysics Data System (ADS)

Tan, P. K.; Kurtsiefer, C.

2017-08-01

Some stellar objects exhibit very narrow spectral lines in the visible range additional to their blackbody radiation. Natural lasing has been suggested as a mechanism to explain narrow lines in Wolf-Rayet stars. However, the spectral resolution of conventional astronomical spectrographs is still about two orders of magnitude too low to test this hypothesis. We want to resolve the linewidth of narrow spectral emissions in starlight. A combination of spectral filtering with single-photon-level temporal correlation measurements breaks the resolution limit of wavelength-dispersing spectrographs by moving the linewidth measurement into the time domain. We demonstrate in a laboratory experiment that temporal intensity interferometry can determine a 20-MHz-wide linewidth of Doppler-broadened laser light and identify a coherent laser light contribution in a blackbody radiation background.

Evaluation of a Combined Cyclone and Gas Filtration System for Particulate Removal in the Gasification Process

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

Rizzo, Jeffrey J.

2010-04-30

The Wabash gasification facility, owned and operated by sgSolutions LLC, is one of the largest single train solid fuel gasification facilities in the world capable of transforming 2,000 tons per day of petroleum coke or 2,600 tons per day of bituminous coal into synthetic gas for electrical power generation. The Wabash plant utilizes Phillips66 proprietary E-Gas (TM) Gasification Process to convert solid fuels such as petroleum coke or coal into synthetic gas that is fed to a combined cycle combustion turbine power generation facility. During plant startup in 1995, reliability issues were realized in the gas filtration portion of themore » gasification process. To address these issues, a slipstream test unit was constructed at the Wabash facility to test various filter designs, materials and process conditions for potential reliability improvement. The char filtration slipstream unit provided a way of testing new materials, maintenance procedures, and process changes without the risk of stopping commercial production in the facility. It also greatly reduced maintenance expenditures associated with full scale testing in the commercial plant. This char filtration slipstream unit was installed with assistance from the United States Department of Energy (built under DOE Contract No. DE-FC26-97FT34158) and began initial testing in November of 1997. It has proven to be extremely beneficial in the advancement of the E-Gas (TM) char removal technology by accurately predicting filter behavior and potential failure mechanisms that would occur in the commercial process. After completing four (4) years of testing various filter types and configurations on numerous gasification feed stocks, a decision was made to investigate the economic and reliability effects of using a particulate removal gas cyclone upstream of the current gas filtration unit. A paper study had indicated that there was a real potential to lower both installed capital and operating costs by implementing a

Circulating tumor cell isolation: the assets of filtration methods with polycarbonate track-etched filters

PubMed Central

Dolfus, Claire; Piton, Nicolas; Toure, Emmanuel

2015-01-01

Circulating tumor cells (CTCs) arise from primary or secondary tumors and enter the bloodstream by active or passive intravasation. Given the low number of CTCs, enrichment is necessary for detection. Filtration methods are based on selection of CTCs by size using a filter with 6.5 to 8 µm pores. After coloration, collected CTCs are evaluated according to morphological criteria. Immunophenotyping and fluorescence in situ hybridization techniques may be used. Selected CTCs can also be cultivated in vitro to provide more material. Analysis of genomic mutations is difficult because it requires adapted techniques due to limited DNA materials. Filtration-selected CTCs have shown prognostic value in many studies but multicentric validating trials are mandatory to strengthen this assessment. Other clinical applications are promising such as follow-up, therapy response prediction and diagnosis. Microfluidic emerging systems could optimize filtration-selected CTCs by increasing selection accuracy. PMID:26543334

Glomerular filtration rate and kidney size in type 2 (non-insulin-dependent) diabetes mellitus.

PubMed

Wirta, O R; Pasternack, A I

1995-07-01

The objective of the present study was to estimate glomerular filtration rate and kidney size in recently diagnosed and long-term type 2 (non-insulin-dependent) diabetic subjects. The study design comprised of a population-based controlled cross-sectional survey of middle-aged type 2 diabetic subjects in the City of Tampere, Southwest Finland. One hundred and fifty consecutive recently diagnosed and 146 long-term middle-aged type 2 diabetic subjects with a disease duration of at least five years and one hundred and fifty age- and sex-matched (to recent diabetic subjects) non-diabetic control subjects were recruited. The glomerular filtration rate by single-shot 51Cr-EDTA clearance and kidney size by native X-ray tomography were measured. The glomerular filtration rate (ml/min/1.73 m2) was increased in both recently diagnosed (males 121 [27] and females 112 [27]) and long-term (males 123 [24] and females 102 [36]) diabetic subjects (corrected for age) compared to control subjects (males 111 [26] and females 93 [17]). The kidney areas (cm2) were greater in both recent diabetic (males 116.6 [15.4] and females 99.1 [15.3] and long-term diabetic (males 118.3 [15.8] and females 100.4 [15.2]) subjects than in the control group (males 104.3 [12.0] and females 88.6 [12.0]). All differences between diabetic subjects and non-diabetic subjects were statistically significant (p < 0.05), except that between long-term diabetic and non-diabetic females for glomerular filtration rate (p = 0.07). Analyzed by linear regression glomerular filtration rate was related to kidney area in all study groups and to hemoglobin A1c in long-term diabetic males.(ABSTRACT TRUNCATED AT 250 WORDS)

Three-stage Fabry-Perot liquid crystal tunable filter with extended spectral range.

PubMed

Zheng, Zhenrong; Yang, Guowei; Li, Haifeng; Liu, Xu

2011-01-31

A method to extend spectral range of tunable optical filter is proposed in this paper. Two same tunable Fabry-Perot filters and an additional tunable filter with different free spectral range are cascaded to extend spectral range and reduce sidelobes. Over 400 nm of free spectral range and 4 nm of full width at half maximum of the filter were achieved. Design procedure and simulation are described in detail. An experimental 3-stage tunable Fabry-Perot filter with visible and infrared spectra is demonstrated. The experimental results and the theoretical analysis are presented in detail to verify this method. The results revealed that a compact and extended tunable spectral range of Fabry-Perot filter can be easily attainable by this method.

Circular dichroism of stem bromelain: a third spectral class within the family of cysteine proteinases.

PubMed Central

Arroyo-Reyna, A; Hernandez-Arana, A; Arreguin-Espinosa, R

1994-01-01

Two forms of stem bromelain (EC 3.4.22.4) were isolated from commercial, crude and chromatographically purified preparations of the enzyme by means of gel-filtration and cation-exchange liquid chromatography. These forms possess nearly identical secondary and tertiary structures, as judged from their circular dichroism (c.d.) spectra. The spectral characteristics of stem bromelain suggest that this enzyme belongs to the alpha + beta protein class, as other cysteine proteinases do. In agreement with these results, quantitative estimation of secondary structures yielded amounts similar to those for papain and proteinase omega. However, the bromelain c.d. curve is clearly distinguishable from those reported for papain and proteinase omega, on one hand, and that of chymopapain, on the other. Thus, it is apparent that there are at least three types of c.d. spectra associated with the family of cysteine proteinases. PMID:8198520

Spectral Characteristics of VLF Sferics Associated With RHESSI TGFs.

PubMed

Mezentsev, Andrew; Lehtinen, Nikolai; Østgaard, Nikolai; Pérez-Invernón, F J; Cummer, Steven A

2018-01-16

We compared the modeled energy spectral density of very low frequency (VLF) radio emissions from terrestrial gamma ray flashes (TGFs) with the energy spectral density of VLF radio sferics recorded by Duke VLF receiver simultaneously with those TGFs. In total, six events with world wide lightning location network (WWLLN) defined locations were analyzed to exhibit a good fit between the modeled and observed energy spectral densities. In VLF range the energy spectral density of the TGF source current moment is found to be dominated by the contribution of secondary low-energy electrons and independent of the relativistic electrons which play their role in low-frequency (LF) range. Additional spectral modulation by the multiplicity of TGF peaks was found and demonstrated a good fit for two TGFs whose VLF sferics consist of two overlapping pulses each. The number of seeding pulses in TGF defines the spectral shape in VLF range, which allows to retrieve this number from VLF sferics, assuming they were radiated by TGFs. For two events it was found that the number of seeding pulses is small, of the order of 10. For the rest of the events the lower boundary of the number of seeding pulses was found to be between 10 to 10 3 .

Spectral Characteristics of VLF Sferics Associated With RHESSI TGFs

NASA Astrophysics Data System (ADS)

Mezentsev, Andrew; Lehtinen, Nikolai; Østgaard, Nikolai; Pérez-Invernón, F. J.; Cummer, Steven A.

2018-01-01

We compared the modeled energy spectral density of very low frequency (VLF) radio emissions from terrestrial gamma ray flashes (TGFs) with the energy spectral density of VLF radio sferics recorded by Duke VLF receiver simultaneously with those TGFs. In total, six events with world wide lightning location network (WWLLN) defined locations were analyzed to exhibit a good fit between the modeled and observed energy spectral densities. In VLF range the energy spectral density of the TGF source current moment is found to be dominated by the contribution of secondary low-energy electrons and independent of the relativistic electrons which play their role in low-frequency (LF) range. Additional spectral modulation by the multiplicity of TGF peaks was found and demonstrated a good fit for two TGFs whose VLF sferics consist of two overlapping pulses each. The number of seeding pulses in TGF defines the spectral shape in VLF range, which allows to retrieve this number from VLF sferics, assuming they were radiated by TGFs. For two events it was found that the number of seeding pulses is small, of the order of 10. For the rest of the events the lower boundary of the number of seeding pulses was found to be between 10 to 103.

PILOT-SCALE EVALUATION OF TOP-INLET AND ADVANCED ELECTROSTATIC FILTRATION

EPA Science Inventory

The report gives results of an evaluation of Advanced Electrostatic Augmentation of Fabric Filtration (ESFF) on a slipstream from a stoker-fired boiler. Advanced ESFF, with its characteristic high-voltage center-wire electrode, was compared with conventional filter bags in the sa...

FOCUSR: Feature Oriented Correspondence using Spectral Regularization–A Method for Precise Surface Matching

PubMed Central

Lombaert, Herve; Grady, Leo; Polimeni, Jonathan R.; Cheriet, Farida

2013-01-01

Existing methods for surface matching are limited by the trade-off between precision and computational efficiency. Here we present an improved algorithm for dense vertex-to-vertex correspondence that uses direct matching of features defined on a surface and improves it by using spectral correspondence as a regularization. This algorithm has the speed of both feature matching and spectral matching while exhibiting greatly improved precision (distance errors of 1.4%). The method, FOCUSR, incorporates implicitly such additional features to calculate the correspondence and relies on the smoothness of the lowest-frequency harmonics of a graph Laplacian to spatially regularize the features. In its simplest form, FOCUSR is an improved spectral correspondence method that nonrigidly deforms spectral embeddings. We provide here a full realization of spectral correspondence where virtually any feature can be used as additional information using weights on graph edges, but also on graph nodes and as extra embedded coordinates. As an example, the full power of FOCUSR is demonstrated in a real case scenario with the challenging task of brain surface matching across several individuals. Our results show that combining features and regularizing them in a spectral embedding greatly improves the matching precision (to a sub-millimeter level) while performing at much greater speed than existing methods. PMID:23868776

Spectral density of mixtures of random density matrices for qubits

NASA Astrophysics Data System (ADS)

Zhang, Lin; Wang, Jiamei; Chen, Zhihua

2018-06-01

We derive the spectral density of the equiprobable mixture of two random density matrices of a two-level quantum system. We also work out the spectral density of mixture under the so-called quantum addition rule. We use the spectral densities to calculate the average entropy of mixtures of random density matrices, and show that the average entropy of the arithmetic-mean-state of n qubit density matrices randomly chosen from the Hilbert-Schmidt ensemble is never decreasing with the number n. We also get the exact value of the average squared fidelity. Some conjectures and open problems related to von Neumann entropy are also proposed.

Development of a digital-micromirror-device-based multishot snapshot spectral imaging system.

PubMed

Wu, Yuehao; Mirza, Iftekhar O; Arce, Gonzalo R; Prather, Dennis W

2011-07-15

We report on the development of a digital-micromirror-device (DMD)-based multishot snapshot spectral imaging (DMD-SSI) system as an alternative to current piezostage-based multishot coded aperture snapshot spectral imager (CASSI) systems. In this system, a DMD is used to implement compressive sensing (CS) measurement patterns for reconstructing the spatial/spectral information of an imaging scene. Based on the CS measurement results, we demonstrated the concurrent reconstruction of 24 spectral images. The DMD-SSI system is versatile in nature as it can be used to implement independent CS measurement patterns in addition to spatially shifted patterns that piezostage-based systems can offer. © 2011 Optical Society of America

Comparison of bedside assessed arm and leg fluid filtration determined by venous congestion plethysmography in perioperative cancer patients

PubMed Central

Hunsicker, Oliver; Heinig, Sandra; Dathe, Jana-Jennifer; Krannich, Alexander; Spies, Claudia; Feldheiser, Aarne

2017-01-01

Abstract In recent years, pathophysiology and clinical impact of microvascular fluid filtration has regained interest. As the latest data in surgical patients have been published almost 20 years ago, there is need for further research to better understand fluid filtration during the perioperative period. Venous congestion plethysmography (VCP) provides a rapid and noninvasive method, which has been shown suitable for the assessment of fluid filtration in limbs. Fluid filtration assessed by VCP can be obtained from forearm and calf measurement sites, while in many clinical situations a reduced access to the patient often restricts the measurements to patient's forearm. We aimed to investigate if fluid filtration obtained from forearm and calf measurement site is interchangeable in nonsedated perioperative patients. Fluid filtration by VCP was obtained simultaneously from forearm and calf in patients with ovarian cancer at 4 time points during the perioperative course and assessed by the difference of volume changes of the limb between third and sixth minutes (VC6-3min) during venous congestion. VC6-3min obtained from forearm and calf measurement sites was compared with respect to agreement and evaluated regarding the association with the presence of leg edema. A total of 74 paired measurements were analyzed in 29 patients. Forearm VC6-3min was significantly higher than calf VC6-3min (median [25th; 75th quartile], 0.6 (0.4; 0.9) vs 0.4 [0.3; 0.6] %, P = 0.008). Bland–Altman and Polar analysis revealed a poor agreement between forearm and calf VC6-3min at predefined time points and changes of VC6-3min during the perioperative course (bias +0.23%, limits of agreement [LOA] −1.1% to 1.6%; angular bias −2.5°, radial LOA −82° to +77°). Forearm VC6-3min was significantly increased in patients with presence of leg edema (0.7 (0.5; 1.0) vs 0.5 (0.4; 0.6) %, P < 0.001) while calf VC6-3min did not differ in patients with and without edema. This study

Advances in Spectral-Spatial Classification of Hyperspectral Images

NASA Technical Reports Server (NTRS)

Fauvel, Mathieu; Tarabalka, Yuliya; Benediktsson, Jon Atli; Chanussot, Jocelyn; Tilton, James C.

2012-01-01

Recent advances in spectral-spatial classification of hyperspectral images are presented in this paper. Several techniques are investigated for combining both spatial and spectral information. Spatial information is extracted at the object (set of pixels) level rather than at the conventional pixel level. Mathematical morphology is first used to derive the morphological profile of the image, which includes characteristics about the size, orientation and contrast of the spatial structures present in the image. Then the morphological neighborhood is defined and used to derive additional features for classification. Classification is performed with support vector machines using the available spectral information and the extracted spatial information. Spatial post-processing is next investigated to build more homogeneous and spatially consistent thematic maps. To that end, three presegmentation techniques are applied to define regions that are used to regularize the preliminary pixel-wise thematic map. Finally, a multiple classifier system is defined to produce relevant markers that are exploited to segment the hyperspectral image with the minimum spanning forest algorithm. Experimental results conducted on three real hyperspectral images with different spatial and spectral resolutions and corresponding to various contexts are presented. They highlight the importance of spectral-spatial strategies for the accurate classification of hyperspectral images and validate the proposed methods.

Results of ACTIM: an EDA study on spectral laser imaging

NASA Astrophysics Data System (ADS)

Hamoir, Dominique; Hespel, Laurent; Déliot, Philippe; Boucher, Yannick; Steinvall, Ove; Ahlberg, Jörgen; Larsson, Hakan; Letalick, Dietmar; Lutzmann, Peter; Repasi, Endre; Ritt, Gunnar

2011-11-01

The European Defence Agency (EDA) launched the Active Imaging (ACTIM) study to investigate the potential of active imaging, especially that of spectral laser imaging. The work included a literature survey, the identification of promising military applications, system analyses, a roadmap and recommendations. Passive multi- and hyper-spectral imaging allows discriminating between materials. But the measured radiance in the sensor is difficult to relate to spectral reflectance due to the dependence on e.g. solar angle, clouds, shadows... In turn, active spectral imaging offers a complete control of the illumination, thus eliminating these effects. In addition it allows observing details at long ranges, seeing through degraded atmospheric conditions, penetrating obscurants (foliage, camouflage...) or retrieving polarization information. When 3D, it is suited to producing numerical terrain models and to performing geometry-based identification. Hence fusing the knowledge of ladar and passive spectral imaging will result in new capabilities. We have identified three main application areas for active imaging, and for spectral active imaging in particular: (1) long range observation for identification, (2) mid-range mapping for reconnaissance, (3) shorter range perception for threat detection. We present the system analyses that have been performed for confirming the interests, limitations and requirements of spectral active imaging in these three prioritized applications.

Development of Precoat Filtration Technology for Reverse Osmosis Units

DTIC Science & Technology

1981-11-20

CONTRACT DAAK 70-79-C-0046 0 FINAL REPORT 0 DEVELOPMENT OF PRECOAT FILTRATION TECHNOLOGY FOR REVERSE OSMOSIS UNITS Submitted by: ,i JOHNS - MANVILLE SALES...NTU (Hach). The one square foot vertical leaf filter was set up at the Johns - Manville R&D Center as shown in Figure 1. A 300 gallon feed tank was

Accelerated recovery from nephrotic syndrome with acute renal failure by double filtration plasmapheresis in a patient with lupus podocytopathy.

PubMed

Iwazu, Yoshitaka; Akimoto, Tetsu; Izawa, Sayoko; Inoue, Makoto; Muto, Shigeaki; Ando, Yasuhiro; Iwazu, Kana; Fukushima, Noriyoshi; Yumura, Wako; Kusano, Eiji

2012-06-01

We describe a case of an adult female who presented with nephrotic syndrome. She was diagnosed with systemic lupus erythematosus with serum antinuclear antibodies, leucopenia with lymphopenia, butterfly erythema, and nephrotic syndrome. Renal biopsy revealed normal glomeruli with diffuse effacement of the foot processes, consistent with lupus podocytopathy. Although human albumin replacement was performed initially, acute renal failure developed rapidly. Therefore, she was treated with double filtration plasmapheresis (DFPP) in addition to oral steroid. After steroid therapy combined with DFPP, the renal function and proteinuria improved rapidly. Although the impact of DFPP on the treatment of lupus nephritis remains to be delineated, our observations suggest that DFPP in lupus podocytopathy played a pivotal role in facilitating the early recovery from renal injuries. Because of the rapid improvement of renal function without any change in body weight by DFPP, acute renal failure in the setting of lupus podocytopathy might contribute to an alternative pathophysiological factor for the diminished glomerular filtration rate, similar to that observed in the setting of idiopathic minimal change glomerulopathy.

Active osmotic exchanger for advanced filtration at the nano scale

NASA Astrophysics Data System (ADS)

Marbach, Sophie; Bocquet, Lyderic

2015-11-01

One of the main functions of the kidney is to remove the waste products of an organism, mostly by excreting concentrated urea while reabsorbing water and other molecules. The human kidney is capable of recycling about 200 liters of water per day, at the relatively low cost of 0.5 kJ/L (standard dialysis requiring at least 150 kJ/L). Kidneys are constituted of millions of parallel filtration networks called nephrons. The nephrons of all mammalian kidneys present a specific loop geometry, the Loop of Henle, that is believed to play a key role in the urinary concentrating mechanism. One limb of the loop is permeable to water and the other contains sodium pumps that exchange with a common interstitium. In this work, we take inspiration from this osmotic exchanger design to propose new nanofiltration principles. We first establish simple analytical results to derive general operating principles, based on coupled water permeable pores and osmotic pumps. The best filtration geometry, in terms of power required for a given water recycling ratio, is comparable in many ways to the mammalian nephron. It is not only more efficient than traditional reverse osmosis systems, but can also work at much smaller pressures (of the order of the blood pressure, 0.13 bar, as compared to more than 30 bars for pressure-retarded osmosis systems). We anticipate that our proof of principle will be a starting point for the development of new filtration systems relying on the active osmotic exchanger principle.

Filtration and clogging of permeable pavement loaded by urban drainage.

PubMed

Sansalone, J; Kuang, X; Ying, G; Ranieri, V

2012-12-15

Permeable pavement, as a sustainable infrastructure material can promote hydrologic restoration, particulate matter (PM) and solute control. However, filtration and commensurate clogging are two aspects of continued interest and discussion. This study quantifies filtration and clogging of cementitious permeable pavement (CPP) for loadings from 50 to 200 mg/L of hetero-disperse sandy-silt PM. The CPP mix design provides a hetero-disperse pore size distribution (PSD)(pore), effective porosity (φ(e)) of 24% and median pore size of 658 μm with a standard deviation of 457 μm. The PM mass separation across the entire particle size distribution (PSD)(PM) exceeds 80%; with complete separation for PM greater than 300 μm and 50% separation for suspended PM. Turbidity is reduced (42-95%), and effluent is below 10 NTU in the first quartile of a loading period. Permeable pavement illustrates reductions in initial (clean-bed) hydraulic conductivity (k(0)) with loading time. For all PM loadings, k(0) (3.1 × 10(-1) mm/s) was reduced to 10(-4) mm/s for runoff loading durations from 100 to 250 h, respectively. Temporal hydraulic conductivity (k) follows exponential profiles. Maintenance by vacuuming and sonication illustrate that 96-99% of k(0) is recovered. Permeable pavement constitutive properties integrated with measured PM loads and a year of continuous rainfall-runoff simulation illustrate k reduction with historical loadings. Study results measure and model filtration and hydraulic conductivity phenomena as well as maintenance requirements of permeable pavement directly loaded by urban drainage. Copyright © 2011. Published by Elsevier Ltd.

PERFORMANCE IMPROVEMENT OF CROSS-FLOW FILTRATION FOR HIGH LEVEL WASTE TREATMENT

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

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

2011-01-12

In the interest of accelerating waste treatment processing, the DOE has funded studies to better understand filtration with the goal of improving filter fluxes in existing cross-flow equipment. The Savannah River National Laboratory (SRNL) was included in those studies, with a focus on start-up techniques, filter cake development, the application of filter aids (cake forming solid precoats), and body feeds (flux enhancing polymers). This paper discusses the progress of those filter studies. Cross-flow filtration is a key process step in many operating and planned waste treatment facilities to separate undissolved solids from supernate slurries. This separation technology generally has themore » advantage of self-cleaning through the action of wall shear stress created by the flow of waste slurry through the filter tubes. However, the ability of filter wall self-cleaning depends on the slurry being filtered. Many of the alkaline radioactive wastes are extremely challenging to filtration, e.g., those containing compounds of aluminum and iron, which have particles whose size and morphology reduce permeability. Unfortunately, low filter flux can be a bottleneck in waste processing facilities such as the Savannah River Modular Caustic Side Solvent Extraction Unit and the Hanford Waste Treatment Plant. Any improvement to the filtration rate would lead directly to increased throughput of the entire process. To date increased rates are generally realized by either increasing the cross-flow filter axial flowrate, limited by pump capacity, or by increasing filter surface area, limited by space and increasing the required pump load. SRNL set up both dead-end and cross-flow filter tests to better understand filter performance based on filter media structure, flow conditions, filter cleaning, and several different types of filter aids and body feeds. Using non-radioactive simulated wastes, both chemically and physically similar to the actual radioactive wastes, the authors

Hydrous iron oxide modified diatomite as an active filtration medium for phosphate capture.

PubMed

Wang, Zhe; Lin, Yan; Wu, Deyi; Kong, Hainan

2016-02-01

A simple method to functionalize diatomite with hydrous iron oxide was attempted and its performance as a new active filtration material to remove and recover phosphate from water was investigated under varying solution conditions. The Langmuir phosphate adsorption capacity increased from 0.6 mgP/g for raw diatomite to 4.89, 14.71, 25.02 mgP/g for hydrous iron oxide modified diatomite (HIOMD), depending on the amount of iron loaded. Loading of hydrous iron oxide caused the increase in true and bulk density and a decline in filtration rate, but to a lesser extent. It was shown that the HIOMD product with suitable iron content could retain a good filtration performance with a greatly increased adsorption capacity for phosphate. The phosphate adsorption increased by decreasing pH and by increasing ionic strength at high pH levels. The adsorption process was interpreted by ligand exchange. Coexisting oxyanions of sulfate, nitrate, citrate, carbonate, silicate and humic acid showed different effects on phosphate fixation but it was presumed that their influence at their concentrations and pH levels commonly encountered in effluent or natural waters was limited, i.e., HIOMD had a reasonably good selectivity. Results in repeated adsorption, desorption and regeneration experiment showed that the adsorbed phosphate could be recovered and the material could be reused after regeneration. The column test showed that HIOMD could be potentially utilized as an adsorption filtration medium for phosphate removal and recovery from water. Copyright © 2015 Elsevier Ltd. All rights reserved.

Examination of Spectral Transformations on Spectral Mixture Analysis

NASA Astrophysics Data System (ADS)

Deng, Y.; Wu, C.

2018-04-01

While many spectral transformation techniques have been applied on spectral mixture analysis (SMA), few study examined their necessity and applicability. This paper focused on exploring the difference between spectrally transformed schemes and untransformed scheme to find out which transformed scheme performed better in SMA. In particular, nine spectrally transformed schemes as well as untransformed scheme were examined in two study areas. Each transformed scheme was tested 100 times using different endmember classes' spectra under the endmember model of vegetation- high albedo impervious surface area-low albedo impervious surface area-soil (V-ISAh-ISAl-S). Performance of each scheme was assessed based on mean absolute error (MAE). Statistical analysis technique, Paired-Samples T test, was applied to test the significance of mean MAEs' difference between transformed and untransformed schemes. Results demonstrated that only NSMA could exceed the untransformed scheme in all study areas. Some transformed schemes showed unstable performance since they outperformed the untransformed scheme in one area but weakened the SMA result in another region.

Alkaline hydrothermal conversion of fly ash filtrates into zeolites 2: utilization in wastewater treatment.

PubMed

Somerset, Vernon; Petrik, Leslie; Iwuoha, Emmanuel

2005-01-01

Filtrates were collected using a codisposal reaction wherein fly ash was reacted with acid mine drainage. These codisposal filtrates were then analyzed by X-ray Fluorescence spectrometry for quantitative determination of the SiO2 and Al2O3 content. Alkaline hydrothermal zeolite synthesis was then applied to the filtrates to convert the fly ash material into zeolites. The zeolites formed under the experimental conditions were faujasite, sodalite, and zeolite A. The use of the fly ash-derived zeolites and a commercial zeolite was explored in wastewater decontamination experiments as it was applied to acid mine drainage in different dosages. The concentrations of Ni, Zn, Cd, As, and Pb metal ions in the treated wastewater were investigated. The results of the treatment of the acid mine drainage with the prepared fly ash zeolites showed that the concentrations of Ni, Zn, Cd, and Hg were decreased as the zeolite dosages of the fly ash zeolite (FAZ1) increased.

Nano-structured silica coated mesoporous carbon micro-granules for potential application in water filtration

NASA Astrophysics Data System (ADS)

Das, Avik; Sen, D.; Mazumder, S.; Ghosh, A. K.

2017-05-01

A novel nano-composite spherical micro-granule has been synthesized using a facile technique of solvent evaporation induced assembly of nanoparticles for potential application in water filtration. The spherical micro-granule is comprised of nano-structured shell of hydrophilic silica encapsulating a hydrophobic mesoporous carbon at the core. Hierarchical structure of such core-shell micro-granules has been rigorously characterized using small-angle neutron and X-ray scattering techniques and complemented with scanning electron microscopy. The hydrophilic silica envelope around the carbon core helps in incorporation of such granules into the hydrophilic polymeric ultra-filtration membrane. The interstitial micro-pores present in the silica shell can serve as water transport channels and the mesoporus carbon core enhances the separation performance due its well adsorption characteristics. It has been found that the incorporation of such granules inside the ultra-filtration membrane indeed enhances the water permeability as well as the separation performance in a significant way.

Spectral analysis of time series of categorical variables in earth sciences

NASA Astrophysics Data System (ADS)

Pardo-Igúzquiza, Eulogio; Rodríguez-Tovar, Francisco J.; Dorador, Javier

2016-10-01

Time series of categorical variables often appear in Earth Science disciplines and there is considerable interest in studying their cyclic behavior. This is true, for example, when the type of facies, petrofabric features, ichnofabrics, fossil assemblages or mineral compositions are measured continuously over a core or throughout a stratigraphic succession. Here we deal with the problem of applying spectral analysis to such sequences. A full indicator approach is proposed to complement the spectral envelope often used in other disciplines. Additionally, a stand-alone computer program is provided for calculating the spectral envelope, in this case implementing the permutation test to assess the statistical significance of the spectral peaks. We studied simulated sequences as well as real data in order to illustrate the methodology.

FRACTIONAL AEROSOL FILTRATION EFFICIENCY OF IN-DUCT VENTILATION AIR CLEANERS

EPA Science Inventory

The filtration efficiency of ventilation air cleaners is highly particle-size dependent over the 0.01 to 3 μm diameter size range. Current standardized test methods, which determine only overall efficiencies for ambient aerosol or other test aerosols, provide data of limited util...

Gas filtration and separation with nano-size ceramics

NASA Astrophysics Data System (ADS)

Lysenko, V. I.; Trufanov, D. Yu.; Bardakhanov, S. P.

2011-06-01

Filtration and separation properties were studied for filters made from open-porosity ceramics (sintered from authors-developed silicon dioxide nanopowder "tarkosil". Key parameters were measured for samples of ceramics produced at different sintering temperatures: porosity, gas permeability coefficient, relative time of standard volume fill-up, gas mixture separation coefficient. The possibility of using the described ceramics for helium enrichment was demonstrated with examples of helium-nitrogen and helium-methane mixtures.

On the Problem of Filtration to an Imperfect Gallery in a Pressureless Bed

NASA Astrophysics Data System (ADS)

Bereslavskii, É. N.; Dudina, L. M.

2018-01-01

The problem of plane steady-state filtration in a pressureless bed to an imperfect gallery in the presence of evaporation from the flow free surface is considered. To study such type of flow, a mixed boundary-value problem of the theory of analytical functions is formulated and solved with application of the Polubarinova-Kochina method. Based on the model suggested, an algorithm for computing the discharge of the gallery and the ordinate of free surface emergence to the impermeable screen is developed. A detailed hydrodynamic analysis of the influence of all physical parameters of the model on the desired filtration characteristics is given.

The effect of nanofiber based filter morphology on bacteria deactivation during water filtration

NASA Astrophysics Data System (ADS)

Kimmer, Dusan; Vincent, Ivo; Lev, Jaroslav; Kalhotka, Libor; Mikula, Premysl; Korinkova, Radka; Sambaer, Wannes; Zatloukal, Martin

2013-04-01

Procedures permitting to prepare homogeneous functionalized nanofibre structures based on polyurethanes modified by phthalocyanines (PCs) by employing a suitable combination of variables during the electrospinning process are presented. Compared are filtration and bacteria deactivation properties of open and planar nanostructures with PCs embedded into polyurethane chain by a covalent bond protecting the release of active organic compound during the filtration process. Finding that the morphology of functionalized nanofibre structures have an effect on bacterial growth was confirmed by microbiological and physico-chemical analyses, such as the inoculation in a nutrient agar culture medium and flow cytometry.

Spectral assessment of new ASTER SWIR surface reflectance data products for spectroscopic mapping of rocks and minerals

USGS Publications Warehouse

Mars, J.C.; Rowan, L.C.

2010-01-01

ASTER reflectance spectra from Cuprite, Nevada, and Mountain Pass, California, were compared to spectra of field samples and to ASTER-resampled AVIRIS reflectance data to determine spectral accuracy and spectroscopic mapping potential of two new ASTER SWIR reflectance datasets: RefL1b and AST_07XT. RefL1b is a new reflectance dataset produced for this study using ASTER Level 1B data, crosstalk correction, radiance correction factors, and concurrently acquired level 2 MODIS water vapor data. The AST_07XT data product, available from EDC and ERSDAC, incorporates crosstalk correction and non-concurrently acquired MODIS water vapor data for atmospheric correction. Spectral accuracy was determined using difference values which were compiled from ASTER band 5/6 and 9/8 ratios of AST_07XT or RefL1b data subtracted from similar ratios calculated for field sample and AVIRIS reflectance data. In addition, Spectral Analyst, a statistical program that utilizes a Spectral Feature Fitting algorithm, was used to quantitatively assess spectral accuracy of AST_07XT and RefL1b data.Spectral Analyst matched more minerals correctly and had higher scores for the RefL1b data than for AST_07XT data. The radiance correction factors used in the RefL1b data corrected a low band 5 reflectance anomaly observed in the AST_07XT and AST_07 data but also produced anomalously high band 5 reflectance in RefL1b spectra with strong band 5 absorption for minerals, such as alunite. Thus, the band 5 anomaly seen in the RefL1b data cannot be corrected using additional gain adjustments. In addition, the use of concurrent MODIS water vapor data in the atmospheric correction of the RefL1b data produced datasets that had lower band 9 reflectance anomalies than the AST_07XT data. Although assessment of spectral data suggests that RefL1b data are more consistent and spectrally more correct than AST_07XT data, the Spectral Analyst results indicate that spectral discrimination between some minerals, such as

Tackling membrane fouling in microalgae filtration using nylon 6,6 nanofiber membrane.

PubMed

Bilad, M R; Azizo, A S; Wirzal, M D H; Jia Jia, L; Putra, Z A; Nordin, N A H M; Mavukkandy, M O; Jasni, M J F; Yusoff, A R M

2018-06-06

Microalgae technology, if managed properly, has promising roles in solving food-water-energy nexus. The Achilles' heel is, however, to lower the costs associated with cultivation and harvesting. As a favorable technique, application of membrane process is strongly limited by membrane fouling. This study evaluates performance of nylon 6,6 nanofiber membrane (NFM) to a conventional polyvinylidene fluoride phase inverted membrane (PVDF PIM) for filtration of Chlorella vulgaris. Results show that nylon 6,6 NFM is superhydrophilic, has higher size of pore opening (0.22 vs 0.18 μm) and higher surface pore density (23 vs 18 pores/μm 2 ) leading to higher permeance (1018 vs 493 L/m 2 hbar) and better fouling resistant. Such advantages help to outperform the filterability of PVDF PIM by showing much higher steady-state permeance (286 vs 120 L/m 2 hbar), with comparable biomass retention. In addition, unlike for PVDF PIM, imposing longer relaxation cycles further enhances the performance of the NFM (i.e., 178 L/m 2 hbar for 0.5 min and 236 L/m 2 hbar for 5 min). Overall findings confirm the advantages of nylon 6,6 NFM over the PVDF PIM. Such advantages can help to reduce required membrane area and specific aeration demand by enabling higher flux and lowering aeration rate. Nevertheless, developments of nylon 6,6 NFM material with respect to its intrinsic properties, mechanical strength and operational conditions of the panel can still be explored to enhance its competitiveness as a promising fouling resistant membrane material for microalgae filtration. Copyright © 2018 Elsevier Ltd. All rights reserved.

A practical approach to spectral calibration of short wavelength infrared hyper-spectral imaging systems

NASA Astrophysics Data System (ADS)

Bürmen, Miran; Pernuš, Franjo; Likar, Boštjan

2010-02-01

Near-infrared spectroscopy is a promising, rapidly developing, reliable and noninvasive technique, used extensively in the biomedicine and in pharmaceutical industry. With the introduction of acousto-optic tunable filters (AOTF) and highly sensitive InGaAs focal plane sensor arrays, real-time high resolution hyper-spectral imaging has become feasible for a number of new biomedical in vivo applications. However, due to the specificity of the AOTF technology and lack of spectral calibration standardization, maintaining long-term stability and compatibility of the acquired hyper-spectral images across different systems is still a challenging problem. Efficiently solving both is essential as the majority of methods for analysis of hyper-spectral images relay on a priori knowledge extracted from large spectral databases, serving as the basis for reliable qualitative or quantitative analysis of various biological samples. In this study, we propose and evaluate fast and reliable spectral calibration of hyper-spectral imaging systems in the short wavelength infrared spectral region. The proposed spectral calibration method is based on light sources or materials, exhibiting distinct spectral features, which enable robust non-rigid registration of the acquired spectra. The calibration accounts for all of the components of a typical hyper-spectral imaging system such as AOTF, light source, lens and optical fibers. The obtained results indicated that practical, fast and reliable spectral calibration of hyper-spectral imaging systems is possible, thereby assuring long-term stability and inter-system compatibility of the acquired hyper-spectral images.