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...

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 141.500 - General requirements.

Code of Federal Regulations, 2013 CFR

2013-07-01

... (CONTINUED) NATIONAL PRIMARY DRINKING WATER REGULATIONS Enhanced Filtration and Disinfection-Systems Serving... for filtration and disinfection that are in addition to criteria under which filtration and disinfection are required under subpart H of this part. The regulations in this subpart establish or extend...

40 CFR 141.500 - General requirements.

Code of Federal Regulations, 2011 CFR

2011-07-01

... (CONTINUED) NATIONAL PRIMARY DRINKING WATER REGULATIONS Enhanced Filtration and Disinfection-Systems Serving... for filtration and disinfection that are in addition to criteria under which filtration and disinfection are required under subpart H of this part. The regulations in this subpart establish or extend...

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...

40 CFR 141.500 - General requirements.

Code of Federal Regulations, 2014 CFR

2014-07-01

... (CONTINUED) NATIONAL PRIMARY DRINKING WATER REGULATIONS Enhanced Filtration and Disinfection-Systems Serving... for filtration and disinfection that are in addition to criteria under which filtration and disinfection are required under subpart H of this part. The regulations in this subpart establish or extend...

40 CFR 141.500 - General requirements.

Code of Federal Regulations, 2012 CFR

2012-07-01

... (CONTINUED) NATIONAL PRIMARY DRINKING WATER REGULATIONS Enhanced Filtration and Disinfection-Systems Serving... for filtration and disinfection that are in addition to criteria under which filtration and disinfection are required under subpart H of this part. The regulations in this subpart establish or extend...

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...

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.

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

Shamsuddin Ilias

Fouling problems are perhaps the single most important reason for relatively slow acceptance of ultrafiltration in many areas of chemical and biological processing. To overcome the losses in permeate flux associated with concentration polarization and fouling in cross flow membrane filtration, we investigated the concept of flow reversal as a method to enhance membrane flux in ultrafiltration. Conceptually, flow reversal prevents the formation of stable hydrodynamic and concentration boundary layers at or near the membrane surface. Further more, periodic reversal of the flow direction of the feed stream at the membrane surface results in prevention and mitigation of membrane fouling.more » Consequently, these advantages are expected to enhance membrane flux significantly. A crossflow membrane filtration unit was designed and built to test the concept of periodic flow reversal for flux enhancement. The essential elements of the system include a crossflow hollow fiber membrane module integrated with a two-way valve to direct the feed flow directions. The two-way valve is controlled by a controller-timer for periodic reversal of flow of feed stream. Another important feature of the system is that with changing feed flow direction, the permeate flow direction is also changed to maintain countercurrent feed and permeate flows for enhanced mass transfer driving force (concentration difference). In this report, we report our application of Flow Reversal technique in clarification of apple juice containing pectin. The presence of pectin in apple juice makes the clarification process difficult and is believed to cause membrane fouling. Of all compounds found in apple juice, pectin is most often identified as the major hindrance to filtration performance. Based on our ultrafiltration experiments with apple juice, we conclude that under flow reversal conditions, the permeate flux is significantly enhanced when compared with the conventional unidirectional flow. Thus, flow reversal technology seems an attractive alternative to mitigate fouling problem in crossflow membrane filtration.« less

Giant larvaceans: biologically equivalent flapping flexible foils exhibit bending modes that enhance fluid transport

NASA Astrophysics Data System (ADS)

Katija, Kakani; Sherman, Alana; Robison, Bruce

2016-11-01

The midwater region of the ocean (below the euphotic zone and above the benthos) is one of the largest ecosystems on our planet, yet remains one of the least explored. Little-known marine organisms that inhabit midwater have developed life strategies that contribute to their evolutionary success, and may inspire engineering solutions for societally relevant challenges. A group of midwater organisms, known as giant larvaceans (genus Bathochordaeus), beat their tails to drive food and particle-laden water through complex, mucus filtering structures to feed. Giant larvaceans, whose motion and kinematics resemble flapping flexible foils, range in size from 1 to 10 cm in length, and can be found between the surface and 400 m. Using remotely-operated vehicles and DeepPIV, an instrument that enables in situ particle image velocimetry (PIV) measurements, the filtration rates and kinematics of giant larvaceans were investigated. These measurements yielded filtration rates for giant larvaceans as high as 80 L/hr, which exceeds expected filtration rates by a factor of 2 when compared with other larvacean groups. Comparing tail kinematics between Bathochordeaus and smaller larvaceans reveals differences in tail bending modes, where a hinge is present throughout the tail beat in giant larvaceans. Using laboratory PIV measurements with swimming animals and soft-bodied mechanical mimics, we reveal how these differences in tail kinematics can lead to enhanced fluid transport. This work has been supported by the Packard Foundation.

40 CFR 141.170 - General requirements.

Code of Federal Regulations, 2014 CFR

2014-07-01

... (CONTINUED) NATIONAL PRIMARY DRINKING WATER REGULATIONS Enhanced Filtration and Disinfection-Systems Serving... filtration and disinfection that are in addition to criteria under which filtration and disinfection are... §§ 141.71 and 141.171 and the disinfection requirements in §§ 141.72 and 141.172; or (2) It meets the...

40 CFR 141.170 - General requirements.

Code of Federal Regulations, 2012 CFR

2012-07-01

... (CONTINUED) NATIONAL PRIMARY DRINKING WATER REGULATIONS Enhanced Filtration and Disinfection-Systems Serving... filtration and disinfection that are in addition to criteria under which filtration and disinfection are... §§ 141.71 and 141.171 and the disinfection requirements in §§ 141.72 and 141.172; or (2) It meets the...

40 CFR 141.170 - General requirements.

Code of Federal Regulations, 2011 CFR

2011-07-01

... (CONTINUED) NATIONAL PRIMARY DRINKING WATER REGULATIONS Enhanced Filtration and Disinfection-Systems Serving... filtration and disinfection that are in addition to criteria under which filtration and disinfection are... §§ 141.71 and 141.171 and the disinfection requirements in §§ 141.72 and 141.172; or (2) It meets the...

40 CFR 141.170 - General requirements.

Code of Federal Regulations, 2013 CFR

2013-07-01

... (CONTINUED) NATIONAL PRIMARY DRINKING WATER REGULATIONS Enhanced Filtration and Disinfection-Systems Serving... filtration and disinfection that are in addition to criteria under which filtration and disinfection are... §§ 141.71 and 141.171 and the disinfection requirements in §§ 141.72 and 141.172; or (2) It meets the...

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 ...

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

Enhancement of microfluidic particle separation using cross-flow filters with hydrodynamic focusing

PubMed Central

Chiu, Yun-Yen; Huang, Chen-Kang

2016-01-01

A microfluidic chip is proposed to separate microparticles using cross-flow filtration enhanced with hydrodynamic focusing. By exploiting a buffer flow from the side, the microparticles in the sample flow are pushed on one side of the microchannels, lining up to pass through the filters. Meanwhile a larger pressure gradient in the filters is obtained to enhance separation efficiency. Compared with the traditional cross-flow filtration, our proposed mechanism has the buffer flow to create a moving virtual boundary for the sample flow to actively push all the particles to reach the filters for separation. It further allows higher flow rates. The device only requires soft lithograph fabrication to create microchannels and a novel pressurized bonding technique to make high-aspect-ratio filtration structures. A mixture of polystyrene microparticles with 2.7 μm and 10.6 μm diameters are successfully separated. 96.2 ± 2.8% of the large particle are recovered with a purity of 97.9 ± 0.5%, while 97.5 ± 0.4% of the small particle are depleted with a purity of 99.2 ± 0.4% at a sample throughput of 10 μl/min. The experiment is also conducted to show the feasibility of this mechanism to separate biological cells with the sample solutions of spiked PC3 cells in whole blood. By virtue of its high separation efficiency, our device offers a label-free separation technique and potential integration with other components, thereby serving as a promising tool for continuous cell filtration and analysis applications. PMID:26858812

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…

Enhanced renal prostaglandin production in the dog. I. Effects on renal function.

PubMed

Tannenbaum, J; Splawinski, J A; Oates, J A; Nies, A S

1975-01-01

The changes in renal function produced by endogenous synthesis of prostaglandins by the kidney were evaluated by infusing sodium arachidonate, the prescursor of the prostaglandins, into one renal artery of the dog. These changes were compared with those produced by similar infusions on performed prostaglandin (PG) E2 and F2alpha.PGE2given at 0.01-0.3 mug/kg min--1 produced dose-related increases in urine flow, sodium and potassium excretion, free water clearance, and renal blood flow. The glomerular filtration rage increased only at the lowest dose and the calculated filtration fraction fell. Arachidonic acid at 1.0-30.0 mug/kg min--1 similarly produced dose-related increases in electrolyte excretion, but the increase in renal blood flow was much less than that produced by PGE2 and there were no changes in glomerular filtration rate, filtration fraction, or free water clearances. PGF2alpha had essentially no effects at infusion rates of 0.03-1.0 mug/kg min--1. All renal effects of arachidonic acid were inhibited by simultaneous infusions of an inhibitor of prostaglandin synthetase, 5, 8, 11,14-eicosatetraynoic acid (20:4). None of the effects produced by PGE2 were inhibited by 20:4. These results indicate that enhanced endogenous renal prostaglandin synthesis, which can be produced by arachidonate infusion, results in significant alterations of renal function. This finding strengthens the hypothesis that renal prostaglandins formed in vivo have physiological importance as regulators of renal function.

Estimates of associated outdoor particulate matter health risk and costs reductions from alternative building, ventilation and filtration scenarios.

PubMed

Sultan, Zuraimi M

2007-05-01

Although many studies have reported calculations of outdoor particulate matter (PM) associated externalities using ambient data, there is little information on the role buildings, their ventilation and filtration play. This study provides the framework to evaluate the health risk and cost reduction of building, ventilation and filtration strategies from outdoor PM pollution on a nationwide level and applied it to a case study in Singapore. Combining Indoor Air Quality (IAQ) and time weighted exposure models, with established concentration-response functions and monetary valuation methods, mortality and morbidity effects of outdoor PM on the population of Singapore under different building, ventilation and filtration strategies were estimated. Different interventions were made to compare the effects from the current building conditions. The findings demonstrate that building protection effect reduced approximately half the attributable health cases amounting to US$17.7 billion due to PM pollution when compared to levels computed using outdoor data alone. For residential buildings, nationwide adoption of natural ventilation from current state is associated with 28% higher cases of mortality and 13 to 38% higher cases for different morbidities, amounting to US$6.7 billion. The incurred cost is negligible compared to energy costs of air-conditioning. However, nationwide adoption of closed residence and air-conditioning are associated with outcomes including fewer mortality (10 and 6% respectively), fewer morbidities (8 and 4% respectively) and economic savings of US$1.5 and 0.9 billion respectively. The related savings were about a factor of 9 the energy cost for air-conditioning. Nationwide adoption of mechanical ventilation and filtration from current natural ventilation in schools is associated with fewer asthma hospital admissions and exacerbations; although the economic impact is not substantial. Enhanced workplace filtration reduces the mortality and morbidity cases by 14 and 13% respectively amounting to savings of up to US$2.4 billion. The huge costs savings are comparable to the average worker salary and insignificant to energy, installation and rental cost. Despite uncertainty about accurate benefits, this study shows that health and economic gain via different building, ventilation and filtration designs in minimizing ingress of outdoor PM applied to a nationwide scale can be very large. Importantly, the results suggest that PM associated externalities and legislative efforts should not only focus on ambient PM reduction policies but also include building-informed decisions.

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

Effective removal of trace thallium from surface water by nanosized manganese dioxide enhanced quartz sand filtration.

PubMed

Huangfu, Xiaoliu; Ma, Chengxue; Ma, Jun; He, Qiang; Yang, Chun; Zhou, Jian; Jiang, Jin; Wang, Yaan

2017-12-01

Thallium (Tl) has drawn wide concern due to its high toxicity even at extremely low concentrations, as well as its tendency for significant accumulation in the human body and other organisms. The need to develop effective strategies for trace Tl removal from drinking water is urgent. In this study, the removal of trace Tl (0.5 μg L -1 ) by conventional quartz sand filtration enhanced by nanosized manganese dioxide (nMnO 2 ) has been investigated using typical surface water obtained from northeast China. The results indicate that nMnO 2 enhanced quartz sand filtration could remove trace Tl(I) and Tl(III) efficiently through the adsorption of Tl onto nMnO 2 added to a water matrix and onto nMnO 2 attached on quartz sand surfaces. Tl(III)-HA complexes might be responsible for higher residual Tl(III) in the effluent compared to residual Tl(I). Competitive Ca 2+ cations inhibit Tl removal to a certain extent because the Ca 2+ ions will occupy the Tl adsorption site on nMnO 2 . Moreover, high concentrations of HA (10 mgTOC L -1 ), which notably complexes with and dissolves nMnO 2 (more than 78%), resulted in higher residual Tl(I) and Tl(III). Tl(III)-HA complexes might also enhance Tl(III) penetration to a certain extent. Additionally, a higher pH level could enhance the removal of trace Tl from surface water. Finally, a slight increase of residual Tl was observed after backwash, followed by the reduction of the Tl concentration in the effluent to a "steady" state again. The knowledge obtained here may provide a potential strategy for drinking water treatment plants threatened by trace Tl. Copyright © 2017. Published by Elsevier Ltd.

Ins(1,4,5)P{sub 3} facilitates ATP accumulation via phosphocreatine/creatine kinase in the endoplasmic reticulum extracted from MDCK cells

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

Sun, Jing; Department of Dental Implantology, School of Stomatology, Tongji University, Shanghai 200072; Ogata, Shigenori

2010-07-02

So far, the content and accumulation of ATP in isolated endoplasmic reticulum (ER) are little understood. First, we confirmed using electron microscopic and Western blotting techniques that the samples extracted from MDCK cells are endoplasmic reticulum (ER). The amounts of ATP in the extracted ER were measured from the filtrate after a spinning down of ultrafiltration spin column packed with ER. When the ER sample (5 {mu}g) after 3 days freezing was suspended in intracellular medium (ICM), 0.1% Triton X and ultrapure water (UPW), ATP amounts from the ER with UPW were the highest and over 10 times compared withmore » that from the control with ICM, indicating that UPW is the most effective tool in destroying the ER membrane. After a 10-min-incubation with ICM containing phosphocreatine (PCr)/creatine kinase (CK) of the fresh ER. ATP amounts in the filtrate obtained by spinning down were not changed from that in the control (no PCr/CK). However, ATP amounts in the filtrate from the second spinning down of the ER (treated with PCr/CK) suspended in UPW became over 10-fold compared with the control. When 1 {mu}M inositol(1,4,5)trisphosphate (Ins(1,4,5)P{sub 3}) was added in the incubation medium (ICM with PCr/CK), ATP amounts from the filtrate after the second spinning down were further enhanced around three times. This enhancement was almost canceled by Ca{sup 2+}-removal from ICM and by adding thapsigargin, a Ca{sup 2+}-ATPase inhibitor, but not by 2-APB and heparin, Ins(1,4,5)P{sub 3} receptor antagonists. Administration of 500 {mu}M adenosine to the incubation medium (with PCr/CK) failed to enhance the accumulation of ATP in the ER. These findings suggest that the ER originally contains ATP and ATP accumulation in the ER is promoted by PCr/CK and Ins(1,4,5)P{sub 3}.« less

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.

Comparison of different options for harvest of a therapeutic protein product from high cell density yeast fermentation broth.

PubMed

Wang, Alice; Lewus, Rachael; Rathore, Anurag S

2006-05-05

Recovery of therapeutic protein from high cell density yeast fermentations at commercial scale is a challenging task. In this study, we investigate and compare three different harvest approaches, namely centrifugation followed by depth filtration, centrifugation followed by filter-aid enhanced depth filtration, and microfiltration. This is achieved by presenting a case study involving recovery of a therapeutic protein from Pichia pastoris fermentation broth. The focus of this study is on performance of the depth filtration and the microfiltration steps. The experimental data has been fitted to the conventional models for cake filtration to evaluate specific cake resistance and cake compressibility. In the case of microfiltration, the experimental data agrees well with flux predicted by shear induced diffusion model. It is shown that, under optimal conditions, all three options can deliver the desired product recovery ( >80%), harvest time ( <15 h including sequential concentration/diafiltration step), and clarification ( <6 NTU). However, the three options differ in terms of process development time required, capital cost, consumable cost, ease of scale-ability and process robustness. It is recommended that these be kept under consideration when making a final decision on a harvesting approach.

Capillary isoelectric focusing with whole column imaging detection (iCIEF): A new approach to the characterization and quantification of salivary α-amylase.

PubMed

Zarabadi, Atefeh S; Huang, Tiemin; Mielke, John G

2017-05-15

Saliva is an easily collected biological fluid with potentially important diagnostic value. While gel electrophoresis is generally used for salivary analysis, we employed the capillary isoelectric focusing technique to allow for a rapid, automated mode of electrophoresis. Capillary isoelectric focusing coupled with UV whole column imaging detection (iCIEF) was used to develop a robust protocol to characterize salivary α-amylase collected from various glands. Notably, three sample preparation methods were examined: ultrafiltration, gel-filtration, and starch affinity interaction with salivary amylase. Salivary α-amylase separated into two major peaks before sample treatment; while both filtration methods and starch affinity interaction of salivary amylase enhanced the resolution of isozymes, desalting with gel-filtration displayed the best recovery and the highest resolution of isozymes. Good agreement existed between the observed isoelectric points and the values reported in the literature. In addition, a high level of precision was apparent, and the relative standard deviation for replicates was less than 0.5% for pIs (peak positions) and below 10% for peak area. Furthermore, saliva secreted from the parotid gland proved to have a higher amylase content compared to either secretions from the submandibular/sublingual complex, or whole saliva, as well as amylase enhancement under stimulation. The results suggest that the iCIEF technique can be used to accurately resolve and quantitate amylase isozymes in a rapid and automated fashion, and that gel-filtration should be applied to saliva samples beforehand to allow for optimal purification and characterization. Copyright © 2017 Elsevier B.V. All rights reserved.

40 CFR 141.718 - Treatment performance toolbox components.

Code of Federal Regulations, 2012 CFR

2012-07-01

...) WATER PROGRAMS (CONTINUED) NATIONAL PRIMARY DRINKING WATER REGULATIONS Enhanced Treatment for.... (a) Combined filter performance. Systems using conventional filtration treatment or direct filtration... the criteria in this paragraph. Combined filter effluent (CFE) turbidity must be less than or equal to...

40 CFR 141.718 - Treatment performance toolbox components.

Code of Federal Regulations, 2013 CFR

2013-07-01

...) WATER PROGRAMS (CONTINUED) NATIONAL PRIMARY DRINKING WATER REGULATIONS Enhanced Treatment for.... (a) Combined filter performance. Systems using conventional filtration treatment or direct filtration... the criteria in this paragraph. Combined filter effluent (CFE) turbidity must be less than or equal to...

40 CFR 141.718 - Treatment performance toolbox components.

Code of Federal Regulations, 2014 CFR

2014-07-01

...) WATER PROGRAMS (CONTINUED) NATIONAL PRIMARY DRINKING WATER REGULATIONS Enhanced Treatment for.... (a) Combined filter performance. Systems using conventional filtration treatment or direct filtration... the criteria in this paragraph. Combined filter effluent (CFE) turbidity must be less than or equal to...

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...

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...

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

Shamsuddin Ilias

Fouling problems are perhaps the single most important reason for relatively slow acceptance of ultrafiltration in many areas of chemical and biological processing. To overcome the losses in permeate flux associated with concentration polarization and fouling in cross flow membrane filtration, we investigated the concept of flow reversal as a method to enhance membrane flux in ultrafiltration. Conceptually, flow reversal prevents the formation of stable hydrodynamic and concentration boundary layers at or near the membrane surface. Further more, periodic reversal of the flow direction of the feed stream at the membrane surface results in prevention and mitigation of membrane fouling.more » Consequently, these advantages are expected to enhance membrane flux significantly. A crossflow membrane filtration unit was designed and built to test the concept of periodic flow reversal for flux enhancement. The essential elements of the system include a crossflow hollow fiber membrane module integrated with a two-way valve to direct the feed flow directions. The two-way valve is controlled by a controller-timer for periodic reversal of flow of feed stream. Another important feature of the system is that with changing feed flow direction, the permeate flow direction is also changed to maintain countercurrent feed and permeate flows for enhanced mass transfer driving force (concentration difference). In our previous report, we reported our work on UF of BSA. In this report, we report our continuing application of Flow Reversal technique in clarification of apple juice containing pectin. The presence of pectin in apple juice makes the clarification process difficult and is believed to cause membrane fouling. Of all compounds found in apple juice, pectin is most often identified as the major hindrance to filtration performance. Laboratory-scale tests on a hollow-fiber ultrafiltration membrane module using pectin in apple juice as feed show that under flow reversal conditions, the permeate flux is significantly enhanced when compared with the conventional unidirectional flow.« less

Respiratory Source Control Using Surgical Masks With Nanofiber Media

PubMed Central

Skaria, Shaji D.; Smaldone, Gerald C.

2014-01-01

Background: Potentially infected individuals (‘source’) are sometimes encouraged to use face masks to reduce exposure of their infectious aerosols to others (‘receiver’). To improve compliance with Respiratory Source Control via face mask and therefore reduce receiver exposure, a mask should be comfortable and effective. We tested a novel face mask designed to improve breathability and filtration using nanofiber filtration. Methods: Using radiolabeled test aerosols and a calibrated exposure chamber simulating source to receiver interaction, facepiece function was measured with a life-like ventilated manikin model. Measurements included mask airflow resistance (pressure difference during breathing), filtration, (mask capture of exhaled radiolabeled test aerosols), and exposure (the transfer of ‘infectious’ aerosols from the ‘source’ to a ‘receiver’). Polydisperse aerosols were measured at the source with a mass median aerodynamic diameter of 0.95 µm. Approximately 90% of the particles were <2.0 µm. Tested facepieces included nanofiber prototype surgical masks, conventional surgical masks, and for comparison, an N95-class filtering facepiece respirator (commonly known as an ‘N95 respirator’). Airflow through and around conventional surgical face mask and nanofiber prototype face mask was visualized using Schlieren optical imaging. Results: Airflow resistance [ΔP, cmH2O] across sealed surgical masks (means: 0.1865 and 0.1791 cmH2O) approached that of the N95 (mean: 0.2664 cmH2O). The airflow resistance across the nanofiber face mask whether sealed or not sealed (0.0504 and 0.0311 cmH2O) was significantly reduced in comparison. In addition, ‘infected’ source airflow filtration and receiver exposure levels for nanofiber face masks placed on the source were comparable to that achieved with N95 placed on the source; 98.98% versus 82.68% and 0.0194 versus 0.0557, respectively. Compared to deflection within and around the conventional face masks, Schlieren optical imaging demonstrated enhanced airflow through the nanofiber mask. Conclusions: Substituting nanofiber for conventional filter media significantly reduced face mask airflow resistance directing more airflow through the face mask resulting in enhanced filtration. Respiratory source control efficacy similar to that achieved through the use of an N95 respirator worn by the source and decreased airflow resistance using nanofiber masks may improve compliance and reduce receiver exposure. PMID:24737728

Respiratory source control using surgical masks with nanofiber media.

PubMed

Skaria, Shaji D; Smaldone, Gerald C

2014-07-01

Potentially infected individuals ('source') are sometimes encouraged to use face masks to reduce exposure of their infectious aerosols to others ('receiver'). To improve compliance with Respiratory Source Control via face mask and therefore reduce receiver exposure, a mask should be comfortable and effective. We tested a novel face mask designed to improve breathability and filtration using nanofiber filtration. Using radiolabeled test aerosols and a calibrated exposure chamber simulating source to receiver interaction, facepiece function was measured with a life-like ventilated manikin model. Measurements included mask airflow resistance (pressure difference during breathing), filtration, (mask capture of exhaled radiolabeled test aerosols), and exposure (the transfer of 'infectious' aerosols from the 'source' to a 'receiver'). Polydisperse aerosols were measured at the source with a mass median aerodynamic diameter of 0.95 µm. Approximately 90% of the particles were <2.0 µm. Tested facepieces included nanofiber prototype surgical masks, conventional surgical masks, and for comparison, an N95-class filtering facepiece respirator (commonly known as an 'N95 respirator'). Airflow through and around conventional surgical face mask and nanofiber prototype face mask was visualized using Schlieren optical imaging. Airflow resistance [ΔP, cmH2O] across sealed surgical masks (means: 0.1865 and 0.1791 cmH2O) approached that of the N95 (mean: 0.2664 cmH2O). The airflow resistance across the nanofiber face mask whether sealed or not sealed (0.0504 and 0.0311 cmH2O) was significantly reduced in comparison. In addition, 'infected' source airflow filtration and receiver exposure levels for nanofiber face masks placed on the source were comparable to that achieved with N95 placed on the source; 98.98% versus 82.68% and 0.0194 versus 0.0557, respectively. Compared to deflection within and around the conventional face masks, Schlieren optical imaging demonstrated enhanced airflow through the nanofiber mask. Substituting nanofiber for conventional filter media significantly reduced face mask airflow resistance directing more airflow through the face mask resulting in enhanced filtration. Respiratory source control efficacy similar to that achieved through the use of an N95 respirator worn by the source and decreased airflow resistance using nanofiber masks may improve compliance and reduce receiver exposure. © The Author 2014. Published by Oxford University Press on behalf of the British Occupational Hygiene Society.

Intravital Imaging Reveals Angiotensin II–Induced Transcytosis of Albumin by Podocytes

PubMed Central

Schießl, Ina Maria; Hammer, Anna; Kattler, Veronika; Gess, Bernhard; Theilig, Franziska; Witzgall, Ralph

2016-01-01

Albuminuria is a hallmark of kidney disease of various etiologies and usually caused by deterioration of glomerular filtration barrier integrity. We recently showed that angiotensin II (Ang II) acutely increases albumin filtration in the healthy kidney. Here, we used intravital microscopy to assess the effects of Ang II on podocyte function in rats. Acute infusion of 30, 60, or 80 ng/kg per minute Ang II enhanced the endocytosis of albumin by activation of the type 1 Ang II receptor and resulted in an average (±SEM) of 3.7±2.2, 72.3±18.6 (P<0.001), and 239.4±34.6 µm3 (P<0.001) albumin-containing vesicles per glomerulus, respectively, compared with none at baseline or 10 ng/kg per minute Ang II. Immunostaining of Ang II–infused kidneys confirmed the presence of albumin-containing vesicles, which colocalized with megalin, in podocin-positive cells. Furthermore, podocyte endocytosis of albumin was markedly reduced in the presence of gentamicin, a competitive inhibitor of megalin-dependent endocytosis. Ang II infusion increased the concentration of albumin in the subpodocyte space, a potential source for endocytic protein uptake, and gentamicin further increased this concentration. Some endocytic vesicles were acidified and colocalized with LysoTracker. Most vesicles migrated from the capillary to the apical aspect of the podocyte and were eventually released into the urinary space. This transcytosis accounted for approximately 10% of total albumin filtration. In summary, the transcellular transport of proteins across the podocyte constitutes a new pathway of glomerular protein filtration. Ang II enhances the endocytosis and transcytosis of plasma albumin by podocytes, which may eventually impair podocyte function. PMID:26116357

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.

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.

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

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.

Mixed submerged fermentation with two filamentous fungi for cellulolytic and xylanolytic enzyme production.

PubMed

Garcia-Kirchner, O; Muñoz-Aguilar, M; Pérez-Villalva, R; Huitrón-Vargas, C

2002-01-01

The efficient saccharification of lignocellulosic materials requires the cooperative actions of different cellulase enzyme activities: exoglucanase, endoglucanase, beta-glucosidase, and xylanase. Previous studies with the fungi strains Aureobasidium sp. CHTE-18, Penicillium sp. CH-TE-001, and Aspergillus terreus CH-TE-013, selected mainly because of their different cellulolytic and xylanolytic activities, have demonstrated the capacity of culture filtrates of cross-synergistic action in the saccharification of native sugarcane bagasse pith. In an attempt to improve the enzymatic hydrolysis of different cellulosic materials, we investigated a coculture fermentation with two of these strains to enhance the production of cellulases and xylanases. The 48-h batch experimental results showed that the mixed culture of Penicillium sp. CH-TE-001 and A. terreus CH-TE-013 produced culture filtrates with high protein content, cellulase (mainly beta-glucosidase), and xylanase activities compared with the individual culture of each strain. The same culture conditions were used in a simple medium with mineral salts, corn syrup liquor, and sugarcane bagasse pith as the sole carbon source with moderate shaking at 29 degrees C. Finally, we compared the effect of the cell-free culture filtrates obtained from the mixed and single fermentations on the saccharification of different kinds of cellulosic materials.

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.

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.

40 CFR 141.552 - My system consists of “alternative filtration” and is required to conduct a demonstration-what is...

Code of Federal Regulations, 2010 CFR

2010-07-01

... AGENCY (CONTINUED) WATER PROGRAMS (CONTINUED) NATIONAL PRIMARY DRINKING WATER REGULATIONS Enhanced Filtration and Disinfection-Systems Serving Fewer Than 10,000 People Combined Filter Effluent Requirements..., that your system's filtration, in combination with disinfection treatment, consistently achieves: (1...

Fluid and solute transfer characteristics in a dialyzer with a high-performance membrane.

PubMed

Mineshima, Michio

2011-01-01

To date, many types of high-flux dialyzers with high-performance membranes have been developed. They seem to have a higher internal filtration flow rate (Q(IF)) because of a higher ultrafiltration coefficient. In the health reimbursement system in Japan, commercially available dialyzers are categorized into five types based on their β(2)-microglobulin clearance (K(BMG)) values. Although the K(BMG) value was not correlated strongly with the Q(IF) value for 26 types of commercially available dialyzers, almost all the dialyzers with a higher Q(IF) value had a higher KBMG value. These dialyzers seem to have a higher convective transport because of internal filtration in addition to diffusive transport. We measured the blood flow velocity in a cross-sectional plane of the dialyzer using pulse Doppler ultra-sonography to evaluate QIF. It is a useful method for the bedside monitoring because it is noninvasive to the patient and produces reliable data with a higher reproducibility. On the other hand, membrane fouling occurs more easily in higher Q(IF) dialyzers, compared with conventional dialyzers, because of the higher degree of membrane fouling. Internal filtration-enhanced hemodialysis (IFEHD) using these dialyzers, therefore, has the advantage of increasing solute removal efficiency by enhancing convective transport and the simultaneous disadvantage of decreasing solute removal efficiency by causing membrane fouling. Thus, IFEHD treatment should be performed using a dialyzer with a high-performance membrane to ensure that the advantage is superior to the disadvantage. Copyright © 2011 S. Karger AG, Basel.

Comparing Nutrient Removal from Membrane Filtered and Unfiltered Domestic Wastewater Using Chlorella vulgaris

PubMed Central

Mayhead, Elyssia; Llewellyn, Carole A.; Fuentes-Grünewald, Claudio

2018-01-01

The nutrient removal efficiency of Chlorella vulgaris cultivated in domestic wastewater was investigated, along with the potential to use membrane filtration as a pre-treatment tool during the wastewater treatment process. Chlorella vulgaris was batch cultivated for 12 days in a bubble column system with two different wastewater treatments. Maximum uptake of 94.18% ammonium (NH4-N) and 97.69% ortho-phosphate (PO4-P) occurred in 0.2 μm membrane filtered primary wastewater. Membrane filtration enhanced the nutrient uptake performance of C. vulgaris by removing bacteria, protozoa, colloidal particles and suspended solids, thereby improving light availability for photosynthesis. The results of this study suggest that growing C. vulgaris in nutrient rich membrane filtered wastewater provides an option for domestic wastewater treatment to improve the quality of the final effluent. PMID:29351200

Enhancing the effectiveness of polyoxyethylene in the filtration of flotation concentrate. [With polyoxyethylene

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

Baichenko, A.A.; Kaminskii, V.S.; Sokolova, V.S.

1977-01-01

Laboratory data are presented on the degradation of polyoxyethylene during storage and under mechanical and chemical action. Provided the physico-chemical properties of the polymer are considered and conditions are adjusted to minimize its degradation during solution preparation, POE can be used as a highly effective flocculant for the commercial filtration of flotation concentrate.

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

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.

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...

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, voltages larger than 50 kV were preferred. For all three phantom sizes stronger filtration led to notable dose reduction for soft tissue imaging. Validation measurements were found to match simulations well, with deviations being less than 10%. Mouse measurements confirmed simulation results. Optimal photon energies and tube settings strongly depend on both phantom size and imaging task at hand. For in vivo CE imaging and density differences, strong filtration and voltages of 50-65 kV showed good overall results. For soft tissue imaging of animals the size of a rat or larger, voltages higher than 65 kV allow to greatly reduce scan times while maintaining dose efficiency. For imaging of bone structures, usage of only minimum filtration and low tube voltages of 40 kV and below allow exploiting the high contrast of bone at very low energies. Therefore, a combination of two filtrations could prove beneficial for micro-CT: a soft filtration allowing for bone imaging at low voltages, and a variable stronger filtration (e.g., 0.2 mm Cu) for soft tissue and contrast-enhanced imaging. © 2012 American Association of Physicists in Medicine.

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.

Citric acid assisted Fenton-like process for enhanced dewaterability of waste activated sludge with in-situ generation of hydrogen peroxide.

PubMed

Xiao, Keke; Pei, Kangyue; Wang, Hui; Yu, Wenbo; Liang, Sha; Hu, Jingping; Hou, Huijie; Liu, Bingchuan; Yang, Jiakuan

2018-09-01

Fenton's reagent has been widely used to enhance sludge dewaterability. However, drawbacks associated with hydrogen peroxide (H 2 O 2 ) in Fenton's reagents exist, since it is a hazardous chemical and shows carcinogenicity, explosivity, instability, and corrosivity. Moreover, initial acidification and subsequent neutralization are needed as optimal conditions for homogeneous Fenton conditioning and final filtrate discharge. In this study, a Fenton-like process for the enhanced dewaterability of waste activated sludge with in-situ generation of H 2 O 2 and without extra pH adjustment was firstly proposed, namely citric acid (CA)-assisted oxygen activation in an air/nano zero-valent iron (nZVI) system and chemical re-coagulation with polydiallyldimethylammonium chloride (PDMDAAC). Using the response surface methodology (RSM), the optimal doses of CA, nZVI, and PDMDAAC were determined to be 13, 33, and 9 mg g -1 dry solids (DS), respectively. This composite conditioner showed a good dewatering capability compared with the raw sludge, e.g. the capillary suction time decreased from 130.0 to 9.5 s. The enhanced sludge dewaterability was further confirmed by laboratory-scale diaphragm filter press dewatering tests, which produced a lower cake moisture content compared with the raw sludge, and the final pH of the filtrate was close to neutrality. The citric acid promoted the production of H 2 O 2 and Fe(II)/Fe(III) species, the degradation of protein in tightly-bound extracellular polymeric substances, and the decomposition of protein-N in the solid phase of sludge, resulting a greater conversion of bound water to free water. The results of electron spin resonance indicated that the hydroxyl radicals were mainly responsible for the decomposition of proteinaceous compounds. The subsequent chemical re-coagulation with PDMDAAC can make the zeta potential of sludge samples less negative, reduce the repulsive electrostatic interactions, and agglomerate the smaller particles into larger aggregates, thus enhancing sludge dewaterability. Copyright © 2018 Elsevier Ltd. All rights reserved.

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 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

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

Presence of Fe-Al binary oxide adsorbent cake layer in ceramic membrane filtration and their impact for removal of HA and BSA.

PubMed

Kim, Kyung-Jo; Jang, Am

2018-04-01

To enhance the removal of natural organic matter (NOM) in ceramic (Ce) membrane filtration, an iron-aluminum binary oxide (FAO) was applied to the ceramic membrane surface as the adsorbent cake layer, and it was compared with heated aluminum oxide (HAO) for the evaluation of the control of NOM. Both the HAO and FAO adsorbent cake layers efficiently removed the NOM regardless of NOM's hydrophobic/hydrophilic characteristics, and the dissolved organic carbon (DOC) removal in NOM for FAO was 1-1.12 times greater than that for HAO, which means FAO was more efficient in the removal of DOC in NOM. FAO (0.03 μm), which is smaller in size than HAO (0.4 μm), had greater flux reduction than HAO. The flux reduction increased as the filtration proceeded because most of the organic foulants (colloid/particles and soluble NOM) were captured by the adsorbent cake layer, which caused fouling between the membrane surface and the adsorbent cake layer. However, no chemically irreversible fouling was observed on the Ce membrane at the end of the FAO adsorbent cake layer filtration. This means that a stable adsorbent cake layer by FAO formed on the Ce membrane, and that the reduced pure water flux of the Ce membrane, resulting from the NOM fouling, can easily be recovered through physicochemical cleaning. Copyright © 2018 Elsevier Ltd. All rights reserved.

Evaluation of systems for reducing the transmission of Porcine reproductive and respiratory syndrome virus by aerosol

PubMed Central

2006-01-01

Abstract The purpose of this study was to compare 3 methods for the reduction of aerosol transmission of Porcine reproductive and respiratory syndrome virus (PRRSV): high-efficiency particulate air (HEPA) filtration, low-cost filtration, and ultraviolet light (UV) irradiation. The HEPA-filtration system involved a pre-filter screen, a bag filter (EU8 rating), and a HEPA filter (EU13 rating). The low-cost-filtration system contained mosquito netting (pre-filter), a fiberglass furnace filter, and an electrostatic furnace filter. For UV irradiation, a lamp emitted UVC radiation at 253.7 nm. 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. 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 9 of the 10 control replicates, 8 of the 10 UVC-irradiation replicates, 4 of the 10 low-cost-filtration replicates, and 0 of the 10 HEPA-filtration replicates. When compared with no intervention, HEPA filtration and low-cost filtration significantly reduced PRRSV transmission (P < 0.0005 and = 0.0286, respectively), whereas UV irradiation had no effect (P = 0.5). However, low-cost filtration and UV irradiation were significantly less effective (P = 0.043 and P < 0.0005, respectively) than HEPA filtration. In conclusion, under the conditions of this study, HEPA filtration was significantly more effective at reducing aerosol transmission of PRRSV than the other methods evaluated. PMID:16548329

Membrane device and process for mass exchange, separation, and filtration

DOEpatents

Liu, Wei; Canfield, Nathan L.

2016-11-15

A membrane device and processes for fabrication and for using are disclosed. The membrane device may include a number of porous metal membranes that provide a high membrane surface area per unit volume. The membrane device provides various operation modes that enhance throughput and selectivity for mass exchange, mass transfer, separation, and/or filtration applications between feed flow streams and permeate flow streams.

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.

Dunaliella spp. Under Environmental Stress: Enhancing Lipid Production and Optimizing Harvest

NASA Astrophysics Data System (ADS)

Mixson, Stephanie Marie

Agricultural crops including corn, sugar cane, and oil palm have been investigated as potential sources for biofuel; however, they produce only a fraction of the oil percent biomass as compared to that of microalgae. Growth and lipid production by microalgae is regulated by a variety of environmental factors, including light intensity, availability of nutrients, temperature regime and salinity. We assessed 14 strains of the saltwater algae Dunaliella spp. (Teodoresco) in unialgal cultures within four species to determine a best strain or strain(s) as potential feedstock for biofuels. The taxonomy of these 14 strains was elucidated by comparing both physiological characteristics and the ITS2 and 18S regions. After careful analysis, the data suggest that the 14 strains grouped within four species: D. tertiolecta, D. pseudosalina, D. salina, and D. viridis. In addition, the isolation and accurate quantification of neutral lipids in Dunaliella was developed from existing techniques. Nile Red was optimized as a qualitative stain to rapidly screen and visualize neutral lipids. Direct transesterification was determined to be the best quantitative method because it yielded high amounts of neutral lipids with precise and reproducible results when compared to conventional extraction methods. Seven strains were selected for further efforts to enhance lipid production using salinity stress, nutrient limitation, pH stress, continuous light, and bubbling with carbon dioxide (CO2). High salinity yielded the maximum total fatty acid (FA) content (up to 65% by dry weight) in comparison to controls (˜10-25% total FAs). High pH x low salinity, low pH, and continuous light x CO2 yielded near maximum FA content (56%, 43%, and 42%, respectively). Nitrogen and/or phosphorus limitation and 12:12 (light:dark photoperiod) x CO 2 did not significantly enhance FA production (23% and 31%, respectively). Results were strain-specific with high intraspecific variation observed within each environmental stressor. Glycerol production, a known mechanism of osmoregulation in Dunaliella, was measured in a short-term salinity stress experiment and found to significantly increase 30 min to 24 hr after exposure. In addition, the glycerol biosynthesis gene, glycerol-3-phosphate dehydrogenase or GPDH, was significantly expressed 30 min to 2 hr in response to hyperosmotic stress. The data suggest that Dunaliella strains may incorporate a proportion of glycerol as triacylglycerol (TAG) under short-term, high-salinity stress. High lipid-producing strains were grown in mass culture, but at this time the commercialization of harvesting has not been proven economically feasible. Autoflocculation, electro-flocculation, and hollow-fiber filtration were compared as potential harvesting mechanisms for the mass culture of Dunaliella spp. Hollow-fiber filtration (>99% biomass recovery) as harvesting mechanism offers many attractive advantages (i.e. reuse of filtrate as culture medium) when compared to auto-flocculation and indirect electroflocculation (>95% biomass recovery). This research provides evidence that Dunaliella can be used as a source of biofuel because these strains can be mass-cultured; their lipids enhanced through a simple high-salinity adjustment; and commercially harvested.

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

The role of aluminum in slow sand filtration.

PubMed

Weber-Shirk, Monroe L; Chan, Kwok Loon

2007-03-01

Engineering enhancement of slow sand filtration has been an enigma in large part because the mechanisms responsible for particle removal have not been well characterized. The presumed role of biological processes in the filter ripening process nearly precluded the possibility of enhancing filter performance since interventions to enhance biological activity would have required decreasing the quality of the influent water. In previous work, we documented that an acid soluble polymer controls filter performance. The new understanding that particle removal is controlled in large part by physical chemical mechanisms has expanded the possibilities of engineering slow sand filter performance. Herein, we explore the role of naturally occurring aluminum as a ripening agent for slow sand filters and the possibility of using a low dose of alum to improve filter performance or to ripen slow sand filters.

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 independent of tube voltage. For 50 mm, voltages larger than 50 kV were preferred. For all three phantom sizes stronger filtration led to notable dose reduction for soft tissue imaging. Validation measurements were found to match simulations well, with deviations being less than 10%. Mouse measurements confirmed simulation results. Conclusions: Optimal photon energies and tube settings strongly depend on both phantom size and imaging task at hand. For in vivo CE imaging and density differences, strong filtration and voltages of 50-65 kV showed good overall results. For soft tissue imaging of animals the size of a rat or larger, voltages higher than 65 kV allow to greatly reduce scan times while maintaining dose efficiency. For imaging of bone structures, usage of only minimum filtration and low tube voltages of 40 kV and below allow exploiting the high contrast of bone at very low energies. Therefore, a combination of two filtrations could prove beneficial for micro-CT: a soft filtration allowing for bone imaging at low voltages, and a variable stronger filtration (e.g., 0.2 mm Cu) for soft tissue and contrast-enhanced imaging.« less

Influence of solid-liquid separation method parameters employed in soil leaching tests on apparent metal concentration.

PubMed

Imoto, Yukari; Yasutaka, Tetsuo; Someya, Masayuki; Higashino, Kazuo

2018-05-15

Soil leaching tests are commonly used to evaluate the leachability of hazardous materials, such as heavy metals, from the soil. Batch leaching tests often enhance soil colloidal mobility and may require solid-liquid separation procedures to remove excess soil particles. However, batch leaching test results depend on particles that can pass through a 0.45μm membrane filter and are influenced by test parameters such as centrifugal intensity and filtration volume per filter. To evaluate these parameters, we conducted batch leaching experiments using metal-contaminated soils and focused on the centrifugal intensity and filtration volume per filter used in solid-liquid separation methods currently employed in standard leaching tests. Our experiments showed that both centrifugal intensity and filtration volume per filter affected the reproducibility of batch leaching tests for some soil types. The results demonstrated that metal concentrations in the filtrates significantly differed according to the centrifugal intensity when it was 3000 g for 2h or less. Increased filtration volume per filter led to significant decreases in filtrate metal concentrations when filter cakes formed during filtration. Comparison of the filtration tests using 0.10 and 0.45μm membrane filters showed statistically significant differences in turbidity and metal concentration. These findings suggest that colloidal particles were not adequately removed from the extract and contributed substantially to the apparent metal concentrations in the leaching test of soil containing colloidal metals. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.

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.

Evaluation of environmental filtration control of engineered nanoparticles using the Harvard Versatile Engineered Nanomaterial Generation System (VENGES)

NASA Astrophysics Data System (ADS)

Tsai, Candace S.-J.; Echevarría-Vega, Manuel E.; Sotiriou, Georgios A.; Santeufemio, Christopher; Schmidt, Daniel; Demokritou, Philip; Ellenbecker, Michael

2012-05-01

Applying engineering controls to airborne engineered nanoparticles (ENPs) is critical to prevent environmental releases and worker exposure. This study evaluated the effectiveness of two air sampling and six air cleaning fabric filters at collecting ENPs using industrially relevant flame-made engineered nanoparticles generated using a versatile engineered nanomaterial generation system (VENGES), recently designed and constructed at Harvard University. VENGES has the ability to generate metal and metal oxide exposure atmospheres while controlling important particle properties such as primary particle size, aerosol size distribution, and agglomeration state. For this study, amorphous SiO2 ENPs with a 15.4 nm primary particle size were generated and diluted with HEPA-filtered air. The aerosol was passed through the filter samples at two different filtration face velocities (2.3 and 3.5 m/min). Particle concentrations as a function of particle size were measured upstream and downstream of the filters using a specially designed filter test system to evaluate filtration efficiency. Real time instruments (FMPS and APS) were used to measure particle concentration for diameters from 5 to 20,000 nm. Membrane-coated fabric filters were found to have enhanced nanoparticle collection efficiency by 20-46 % points compared to non-coated fabric and could provide collection efficiency above 95 %.

Removal of trace metal contaminants from potable water by electrocoagulation.

PubMed

Heffron, Joe; Marhefke, Matt; Mayer, Brooke K

2016-06-21

This study investigated the effects of four operational and environmental variables on the removal of trace metal contaminants from drinking water by electrocoagulation (EC). Removal efficiencies for five metals (arsenic, cadmium, chromium, lead and nickel) were compared under varying combinations of electrode material, post-treatment, water composition and pH. Iron electrodes out-performed aluminum electrodes in removing chromium and arsenic. At pH 6.5, aluminum electrodes were slightly more effective at removing nickel and cadmium, while at pH 8.5, iron electrodes were more effective for these metals. Regardless of electrode, cadmium and nickel removal efficiencies were higher at pH 8.5 than at pH 6.5. Post-EC treatment using membrane filtration (0.45 μm) enhanced contaminant removal for all metals but nickel. With the exception of lead, all metals exhibited poorer removal efficiencies as the ionic strength of the background electrolyte increased, particularly in the very high-solids synthetic groundwaters. Residual aluminum concentrations were lowest at pH 6.5, while iron residuals were lowest in low ionic strength waters. Both aluminum and iron residuals required post-treatment filtration to meet drinking water standards. EC with post-treatment filtration appears to effectively remove trace metal contaminants to potable water standards, but both reactor and source water parameters critically impact removal efficiency.

Evaluation of environmental filtration control of engineered nanoparticles using the Harvard Versatile Engineered Nanomaterial Generation System (VENGES)

PubMed Central

Echevarría-Vega, Manuel E.; Sotiriou, Georgios A.; Santeufemio, Christopher; Schmidt, Daniel; Demokritou, Philip; Ellenbecker, Michael

2013-01-01

Applying engineering controls to airborne engineered nanoparticles (ENPs) is critical to prevent environmental releases and worker exposure. This study evaluated the effectiveness of two air sampling and six air cleaning fabric filters at collecting ENPs using industrially relevant flame-made engineered nanoparticles generated using a versatile engineered nanomaterial generation system (VENGES), recently designed and constructed at Harvard University. VENGES has the ability to generate metal and metal oxide exposure atmospheres while controlling important particle properties such as primary particle size, aerosol size distribution, and agglomeration state. For this study, amorphous SiO2 ENPs with a 15.4 nm primary particle size were generated and diluted with HEPA-filtered air. The aerosol was passed through the filter samples at two different filtration face velocities (2.3 and 3.5 m/min). Particle concentrations as a function of particle size were measured upstream and downstream of the filters using a specially designed filter test system to evaluate filtration efficiency. Real time instruments (FMPS and APS) were used to measure particle concentration for diameters from 5 to 20,000 nm. Membrane-coated fabric filters were found to have enhanced nanoparticle collection efficiency by 20–46 % points compared to non-coated fabric and could provide collection efficiency above 95 %. PMID:23412707

Removal of trace metal contaminants from potable water by electrocoagulation

NASA Astrophysics Data System (ADS)

Heffron, Joe; Marhefke, Matt; Mayer, Brooke K.

2016-06-01

This study investigated the effects of four operational and environmental variables on the removal of trace metal contaminants from drinking water by electrocoagulation (EC). Removal efficiencies for five metals (arsenic, cadmium, chromium, lead and nickel) were compared under varying combinations of electrode material, post-treatment, water composition and pH. Iron electrodes out-performed aluminum electrodes in removing chromium and arsenic. At pH 6.5, aluminum electrodes were slightly more effective at removing nickel and cadmium, while at pH 8.5, iron electrodes were more effective for these metals. Regardless of electrode, cadmium and nickel removal efficiencies were higher at pH 8.5 than at pH 6.5. Post-EC treatment using membrane filtration (0.45 μm) enhanced contaminant removal for all metals but nickel. With the exception of lead, all metals exhibited poorer removal efficiencies as the ionic strength of the background electrolyte increased, particularly in the very high-solids synthetic groundwaters. Residual aluminum concentrations were lowest at pH 6.5, while iron residuals were lowest in low ionic strength waters. Both aluminum and iron residuals required post-treatment filtration to meet drinking water standards. EC with post-treatment filtration appears to effectively remove trace metal contaminants to potable water standards, but both reactor and source water parameters critically impact removal efficiency.

Sex differences in the enhanced responsiveness to acute angiotensin II in growth-restricted rats: role of fasudil, a Rho kinase inhibitor

PubMed Central

Ojeda, Norma B.; Royals, Thomas P.

2013-01-01

This study tested the hypothesis that Rho kinase contributes to the enhanced pressor response to acute angiotensin II in intact male growth-restricted and gonadectomized female growth-restricted rats. Mean arterial pressure (MAP) and renal function were determined in conscious animals pretreated with enalapril (250 mg/l in drinking water) for 1 wk to block the endogenous renin-angiotensin system and normalize blood pressure (baseline). Blood pressure and renal hemodynamics did not differ at baseline. Acute Ang II (100 ng·kg−1·min−1) induced a greater increase in MAP and renal vascular resistance and enhanced reduction in glomerular filtration rate in intact male growth-restricted rats compared with intact male controls (P < 0.05). Cotreatment with the Rho kinase inhibitor fasudil (33 μg·kg−1·min−1) significantly attenuated these hemodynamic changes (P < 0.05), but it did not abolish the differential increase in blood pressure above baseline, suggesting that the impact of intrauterine growth restriction on blood pressure in intact male growth-restricted rats is independent of Rho kinase. Gonadectomy in conjunction with fasudil returned blood pressure back to baseline in male growth-restricted rats, and yet glomerular filtration rate remained significantly reduced (P < 0.05). Thus, these data suggest a role for enhanced renal sensitivity to acute Ang II in the developmental programming of hypertension in male growth-restricted rats. However, inhibition of Rho kinase had no effect on the basal or enhanced increase in blood pressure induced by acute Ang II in the gonadectomized female growth-restricted rat. Therefore, these studies suggest that Rho kinase inhibition exerts a sex-specific effect on blood pressure sensitivity to acute Ang II in growth-restricted rats. PMID:23344570

Sex differences in the enhanced responsiveness to acute angiotensin II in growth-restricted rats: role of fasudil, a Rho kinase inhibitor.

PubMed

Ojeda, Norma B; Royals, Thomas P; Alexander, Barbara T

2013-04-01

This study tested the hypothesis that Rho kinase contributes to the enhanced pressor response to acute angiotensin II in intact male growth-restricted and gonadectomized female growth-restricted rats. Mean arterial pressure (MAP) and renal function were determined in conscious animals pretreated with enalapril (250 mg/l in drinking water) for 1 wk to block the endogenous renin-angiotensin system and normalize blood pressure (baseline). Blood pressure and renal hemodynamics did not differ at baseline. Acute Ang II (100 ng·kg(-1)·min(-1)) induced a greater increase in MAP and renal vascular resistance and enhanced reduction in glomerular filtration rate in intact male growth-restricted rats compared with intact male controls (P < 0.05). Cotreatment with the Rho kinase inhibitor fasudil (33 μg·kg(-1)·min(-1)) significantly attenuated these hemodynamic changes (P < 0.05), but it did not abolish the differential increase in blood pressure above baseline, suggesting that the impact of intrauterine growth restriction on blood pressure in intact male growth-restricted rats is independent of Rho kinase. Gonadectomy in conjunction with fasudil returned blood pressure back to baseline in male growth-restricted rats, and yet glomerular filtration rate remained significantly reduced (P < 0.05). Thus, these data suggest a role for enhanced renal sensitivity to acute Ang II in the developmental programming of hypertension in male growth-restricted rats. However, inhibition of Rho kinase had no effect on the basal or enhanced increase in blood pressure induced by acute Ang II in the gonadectomized female growth-restricted rat. Therefore, these studies suggest that Rho kinase inhibition exerts a sex-specific effect on blood pressure sensitivity to acute Ang II in growth-restricted rats.

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.

Removal of nano and microparticles by granular filter media coated with nanoporous aluminium oxide.

PubMed

Lau, B L T; Harrington, G W; Anderson, M A; Tejedor, I

2004-01-01

Conventional filtration was designed to achieve high levels of particle and pathogen removal. Previous studies have examined the possibility of modifying filtration media to improve their ability to remove microorganisms and viruses. Although these studies have evaluated filter media coatings for this purpose, none have evaluated nanoscale particle suspensions as coating materials. The overall goal of this paper is to describe the preliminary test results of nanoporous aluminium oxide coated media that can be used to enhance filtration of nano and microparticles. Filtration tests were carried out using columns packed with uncoated and coated forms of granular anthracite or granular activated carbon. A positive correlation between isoelectric pH of filter media and particle removal was observed. The modified filter media with a higher isoelectric pH facilitated better removal of bacteriophage MS2 and 3 microm latex microspheres, possibly due to increased favorable electrostatic interactions.

Precise measurement of renal filtration and vascular parameters using a two-compartment model for dynamic contrast-enhanced MRI of the kidney gives realistic normal values.

PubMed

Tofts, Paul S; Cutajar, Marica; Mendichovszky, Iosif A; Peters, A Michael; Gordon, Isky

2012-06-01

To model the uptake phase of T(1)-weighted DCE-MRI data in normal kidneys and to demonstrate that the fitted physiological parameters correlate with published normal values. The model incorporates delay and broadening of the arterial vascular peak as it appears in the capillary bed, two distinct compartments for renal intravascular and extravascular Gd tracer, and uses a small-vessel haematocrit value of 24%. Four physiological parameters can be estimated: regional filtration K ( trans ) (ml min(-1) [ml tissue](-1)), perfusion F (ml min(-1) [100 ml tissue](-1)), blood volume v ( b ) (%) and mean residence time MRT (s). From these are found the filtration fraction (FF; %) and total GFR (ml min(-1)). Fifteen healthy volunteers were imaged twice using oblique coronal slices every 2.5 s to determine the reproducibility. Using parenchymal ROIs, group mean values for renal biomarkers all agreed with published values: K ( trans ): 0.25; F: 219; v ( b ): 34; MRT: 5.5; FF: 15; GFR: 115. Nominally cortical ROIs consistently underestimated total filtration (by ~50%). Reproducibility was 7-18%. Sensitivity analysis showed that these fitted parameters are most vulnerable to errors in the fixed parameters kidney T(1), flip angle, haematocrit and relaxivity. These renal biomarkers can potentially measure renal physiology in diagnosis and treatment. • Dynamic contrast-enhanced magnetic resonance imaging can measure renal function. • Filtration and perfusion values in healthy volunteers agree with published normal values. • Precision measured in healthy volunteers is between 7 and 15%.

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.

[Effects of algicidal bacterium BS03 (Microbulbifer sp.) on the growth and antioxidant systems of Alexandrium tamarense].

PubMed

Fu, Lijun; Li, Dong; Wu, Chengji; Zheng, Tianling

2012-06-04

We studied the algicidal mechanism of extracellular substances of algicidal bacteria strain BS03 (Microbulbifer sp.) on photosynthetic characteristics, antioxident enzyme system and cysteine-dependent aspartate specific protease-3 (Caspase-3) of Alexandrium tamarense. We tested photosynthetic pigments, chlorophyll fluorescence efficiency, antioxidant systems and caspase-3 activity in the algae cells treated with 0.5%, 1.0% , 1.5% and 2.0% BS03 cell-free filtrate after 12, 24, 36 and 48 h. (1) The chlorophyll-a and chlorophyll fluorescence efficiency Fv/Fm decreased with the increase of BS03 cell-free filtrate and treatment time. Carotenoids contents of A. tamarense cells treated with low BS03 (0.5% and 1.0%) cell-free filtrate were higher than the control. (2) Antioxident enzyme activities varied as treatment time and concentration. Malodialdehyde (MDA) contents increased significantly with BS03 cell-free filtrate treatment. (3) Caspase-3 protease activities of algal cells increased by BS03 cell-free filtrate. BS03 inhibited the photosynthesis whereas enhanced the lipid peroxidation of the cellular membrane of Alexandrium tamarense, indicating its algicidal activity.

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 filtration could be a promising technique for use in in vitro fertilization in buffalo. © 2017 Blackwell Verlag GmbH.

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.

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.

Renal Perfusion in Scleroderma Patients Assessed by Microbubble-Based Contrast-Enhanced Ultrasound

PubMed Central

Kleinert, Stefan; Roll, Petra; Baumgaertner, Christian; Himsel, Andrea; Mueller, Adelheid; Fleck, Martin; Feuchtenberger, Martin; Jenett, Manfred; Tony, Hans-Peter

2012-01-01

Objectives: Renal damage is common in scleroderma. It can occur acutely or chronically. Renal reserve might already be impaired before it can be detected by laboratory findings. Microbubble-based contrast-enhanced ultrasound has been demonstrated to improve blood perfusion imaging in organs. Therefore, we conducted a study to assess renal perfusion in scleroderma patients utilizing this novel technique. Materials and Methodology: Microbubble-based contrast agent was infused and destroyed by using high mechanical index by Siemens Sequoia (curved array, 4.5 MHz). Replenishment was recorded for 8 seconds. Regions of interests (ROI) were analyzed in renal parenchyma, interlobular artery and renal pyramid with quantitative contrast software (CUSQ 1.4, Siemens Acuson, Mountain View, California). Time to maximal Enhancement (TmE), maximal enhancement (mE) and maximal enhancement relative to maximal enhancement of the interlobular artery (mE%A) were calculated for different ROIs. Results: There was a linear correlation between the time to maximal enhancement in the parenchyma and the glomerular filtration rate. However, the other parameters did not reveal significant differences between scleroderma patients and healthy controls. Conclusion: Renal perfusion of scleroderma patients including the glomerular filtration rate can be assessed using microbubble-based contrast media. PMID:22670165

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

Rapid profiling of antimicrobial compounds characterising B. subtilis TR50 cell-free filtrate by high-performance liquid chromatography coupled to high-resolution Orbitrap™ mass spectrometry.

PubMed

Monaci, Linda; Quintieri, Laura; Caputo, Leonardo; Visconti, Angelo; Baruzzi, Federico

2016-01-15

Several Bacillus strains, typically isolated from different food sources, represent renowned producers of a multitude of low and high molecular weight compounds, including lipopeptides and macrolactones, with an importance for their antimicrobial activity. The high homology shared by many of these compounds also occurring as closely related isoforms poses a challenge in their prompt detection. Identification and structural elucidation is generally achieved by matrix-assisted laser desorption/ionization (MALDI) or liquid chromatography (LC) coupled to mass spectrometry (MS) after a pre-fractionation and/or purification step of the extract. In this paper we report the application of a method based on LC separation and high-resolution Orbitrap™-based MS for the rapid screening of raw filtrate of the strain Bacillus subtilis TR50 endowed with antimicrobial activity, without requiring any sample pre-treatment. Upon direct analysis of the cell-free filtrate of Bacillus subtilis TR50 by high-resolution mass spectrometry (HRMS), different compounds families, that proved to exert a remarked antimicrobial activity against several foodborne pathogens, can be readily displayed along the chromatographic run. Among them, three different classes were identified and characterized belonging to the iturin, fengycin and surfactin groups. The high resolving power and accurate mass accuracy provided by the HRMS system in use ensured an enhanced selectivity compared to other mass spectrometers. In addition, after activation of the HCD cell, the HR-MS/MS spectra can provide insights in the structural elucidation of several compounds. The acquisition of HRMS spectra of raw filtrates of subtilis strains allows untargeted analysis of the major classes of compounds produced to be performed, thus facilitating identification of other unknown bioactive molecules after retrospective analysis. These features make this approach a fast tool applicable to the rapid screening and further identification of antimicrobial compounds released by Bacillus strains in raw filtrates. Copyright © 2015 John Wiley & Sons, Ltd.

An Investigation on bilayer structures of electrospun polyacrylonitrile nanofibrous membrane and cellulose membrane used as filtration media for apple juice clarification

NASA Astrophysics Data System (ADS)

Sawitri, Asti; Miftahul Munir, Muhammad; Edikresnha, Dhewa; Sandi, Ahzab; Fauzi, Ahmad; Rajak, Abdul; Natalia, Dessy; Khairurrijal, Khairurrijal

2018-05-01

Nanofibrous membrane has a potential to use in filtration technology with electrospinning as one of the techniques used in synthesizing nanofibers. Polyacrylonitrile (PAN) nanofibrous membranes with various fibers diameters were electrospun by varying its precursor solution concentration. The average fibers diameters of the PAN nanofibrous membranes obtained from the precursor solution concentrations of 6, 9, 12, and 14 wt% were 341, 534, 1274, and 2107 nm, respectively. Filtration media for apple juice clarification were bilayer-structured membranes made of PAN nanofibrous membranes on commercial cellulose microfibrous membranes. It has been shown that the reduction of apple juice color or turbidity performed by the cellulose microfibrous membrane was well enhanced by the presence of the PAN nanofibrous membrane in the bilayer-structured membrane. In addition, the apple-juice color and turbidity reductions increased with decreasing the average fibers diameter of the PAN nanofibrous membrane. Furthermore, the PAN nanofibrous membrane also helped the cellulose microfibrous membrane in the bilayer-structured membrane enhance the reductions of total phenols, protein, and glucose of the apple juice.

Single-energy pediatric chest computed tomography with spectral filtration at 100 kVp: effects on radiation parameters and image quality.

PubMed

Bodelle, Boris; Fischbach, Constanze; Booz, Christian; Yel, Ibrahim; Frellesen, Claudia; Kaup, Moritz; Beeres, Martin; Vogl, Thomas J; Scholtz, Jan-Erik

2017-06-01

Most of the applied radiation dose at CT is in the lower photon energy range, which is of limited diagnostic importance. To investigate image quality and effects on radiation parameters of 100-kVp spectral filtration single-energy chest CT using a tin-filter at third-generation dual-source CT in comparison to standard 100-kVp chest CT. Thirty-three children referred for a non-contrast chest CT performed on a third-generation dual-source CT scanner were examined at 100 kVp with a dedicated tin filter with a tube current-time product resulting in standard protocol dose. We compared resulting images with images from children examined using standard single-source chest CT at 100 kVp. We assessed objective and subjective image quality and compared radiation dose parameters. Radiation dose was comparable for children 5 years old and younger, and it was moderately decreased for older children when using spectral filtration (P=0.006). Effective tube current increased significantly (P=0.0001) with spectral filtration, up to a factor of 10. Signal-to-noise ratio and image noise were similar for both examination techniques (P≥0.06). Subjective image quality showed no significant differences (P≥0.2). Using 100-kVp spectral filtration chest CT in children by means of a tube-based tin-filter on a third-generation dual-source CT scanner increases effective tube current up to a factor of 10 to provide similar image quality at equivalent dose compared to standard single-source CT without spectral filtration.

Different methods of hilar clamping during partial nephrectomy: Impact on renal function.

PubMed

Lee, Jeong Woo; Kim, Hwanik; Choo, Minsoo; Park, Yong Hyun; Ku, Ja Hyeon; Kim, Hyeon Hoe; Kwak, Cheol

2014-03-01

To evaluate the impact of different hilar clamping methods on changes in renal function after partial nephrectomy. We analyzed the clinical data of 369 patients who underwent partial nephrectomy for a single renal tumor of size ≤4.0 cm and a normal contralateral kidney. Patients were separated into three groups depending on hilar clamping method: non-clamping, cold ischemia and warm ischemia. Estimated glomerular filtration rate was examined at preoperative, nadir and 1 year postoperatively. Percent change in estimated glomerular filtration rate was used as the parameter to assess the renal functional outcome. Percent change in nadir estimated glomerular filtration rate in the non-clamping group was significantly less compared with the cold ischemia and warm ischemia groups (P < 0.001). However, no significant differences among the groups were noted in percent change of estimated glomerular filtration rate at 1 year (P = 0.348). The cold ischemia group had a similar serial change of postoperative renal function compared with the warm ischemia group. Percent change in 1-year estimated glomerular filtration rate increased with increasing ischemia time in the cold ischemia (P for trend = 0.073) and warm ischemia groups (P for trend = 0.010). On multivariate analysis, hilar clamping (both warm ischemia and cold ischemia) were significantly associated with percent change in nadir estimated glomerular filtration rate, but not in 1-year estimated glomerular filtration rate. Non-clamping partial nephrectomy results in a lower percent change in nadir estimated glomerular filtration rate, whereas it carries an estimated glomerular filtration rate change at 1 year that is similar to partial nephrectomy with cold ischemia and warm ischemia. Cold ischemia and warm ischemia provide a similar effect on renal function. Therefore, when hilar clamping is required, minimization of ischemia time is necessary. © 2013 The Japanese Urological Association.

Enhancing sewage sludge dewaterability by bioleaching approach with comparison to other physical and chemical conditioning methods.

PubMed

Liu, Fenwu; Zhou, Jun; Wang, Dianzhan; Zhou, Lixiang

2012-01-01

The sewage sludge conditioning process is critical to improve the sludge dewaterability prior to mechanical dewatering. Traditionally, sludge is conditioned by physical or chemical approaches, mostly with the addition of inorganic or organic chemicals. Here we report that bioleaching, an efficient and economical microbial method for the removal of sludge-borne heavy metals, also plays a significant role in enhancing sludge dewaterability. The effects of bioleaching and physical or chemical approaches on sludge dewaterability were compared. The conditioning result of bioleaching by Acidithiobacillus thiooxidans and Acidithiobacillus ferrooxidans on sludge dewatering was investigated and compared with the effects of hydrothermal (121 degrees C for 2 hr), microwave (1050 W for 50 sec), ultrasonic (250 W for 2 min), and chemical conditioning (24% ferric chloride and 68% calcium oxide; dry basis). The results show that the specific resistance to filtration (SRF) or capillary suction time (CST) of sludge is decreased by 93.1% or 74.1%, respectively, after fresh sludge is conditioned by bioleaching, which is similar to chemical conditioning treatment with ferric chloride and calcium oxide but much more effective than other conditioning approaches including hydrothermal, microwave, and ultrasonic conditioning. Furthermore, after sludge dewatering, bioleached sludge filtrate contains the lowest concentrations of chroma (18 times), COD (542 mg/L), total N (TN, 300 mg/L), NH4(+)-N (208 mg/L), and total P (TP, 2 mg/L) while the hydrothermal process resulted in the highest concentration of chroma (660 times), COD (18,155 mg/L), TN (472 mg/L), NH4(+)-N (381 mg/L), and TP (191 mg/L) among these selected conditioning methods. Moreover, unlike chemical conditioning, sludge bioleaching does not result in a significant reduction of organic matter, TN, and TP in the resulting dewatered sludge cake. Therefore, considering sludge dewaterability and the chemical properties of sludge filtrate and resulting dewatered sludge cakes, bioleaching has potential as an approach for improving sludge dewaterability and reducing the cost of subsequent reutilization or disposal of dewatered sludge.

Renal handling of sodium and water in the hypothyroid rat

PubMed Central

Michael, Ulrich F.; Barenberg, Robert L.; Chavez, Rafaelita; Vaamonde, Carlos A.; Papper, Solomon

1972-01-01

Hypothyroid rats were examined with conventional renal clearance and micropuncture techniques to elicit the mechanism and site within the nephron responsible for the increased salt and water excretion observed in these animals. When compared with age-matched control rats, a decrease in inulin clearance of 30% (P < 0.001) and in Hippuran clearance of 32% (P < 0.005) was observed in the hypothyroid rats. Absolute excretion of sodium and water was increased 3-fold (P < 0.02) and 2-fold (P < 0.025), respectively, while fractional excretion of sodium and water was increased 4.3-fold (P < 0.02) and 2.9-fold (P < 0.05), respectively, in the hypothyroid animals. Fractional proximal reabsorption of sodium as assessed from proximal tubular fluid to plasma ratios of inulin ([TF/P]IN) was found to be decreased by 28% (P < 0.001) in the hypothyroid rats. Superficial single nephron filtration rate was reduced proportionately to the decrease in total filtration rate in the hypothyroid rats. These data indicate that the proximal tubule is one of the sites of diminished sodium and water reabsorption in the hypothyroid rat. The data also suggest that the observed decrease in glomerular filtration rate in the hypothyroid animals is not caused by a decrease in the number of functioning nephrons and that the observed increase in sodium and water excretion is not caused by a redistribution of filtrate from juxtamedullary to superficial nephrons. Although the exact mechanisms of the observed changes in proximal tubular function remain unknown, the data suggest that they are probably related to the lack of thyroid hormone. Whatever their mechanism, it appears that the enhanced sodium and water excretion observed in the hypothyroid animals must be determined by further reduction in tubular sodium reabsorption in the distal nephron. PMID:5024038

Use of Ceramic Membranes in a Membrane Filtration Supported by Coagulation for the Treatment of Dairy Wastewater.

PubMed

Zielińska, Magdalena; Galik, Maciej

2017-01-01

A membrane filtration system was used to remove organic compounds, suspended solids, colour and turbidity from anaerobically treated dairy wastewater. Direct microfiltration (MF), ultrafiltration (UF), MF-UF and a combination of UF with coagulation using two conventional coagulants were investigated. The installation with ceramic membranes was operated at a pressure of 0.15 MPa (MF) and 0.3 MPa (UF). COD removal was 89 ± 2% in MF, 95 ± 1% in UF and 99% in MF-UF. Apart from size exclusion, removal was also the result of adsorption of organics on the membrane; 3-18% of COD removal was attributed to adsorption. In all these membrane systems, colour removal was 96-98%. Coagulation removed 63-72% of COD at all coagulant doses. In combination with UF, 96-97% of COD was removed. The use of coagulants was ineffective for colour removal; further treatment by UF resulted in above 98% removal. Because of complete rejection of suspended solids, turbidity removal exceeded 99% under all conditions. The use of increased coagulant doses did not have an effect on total efficiency of pollutant removal and on the permeate flux. Coagulation pre-treatment enhanced the performance of filtration only by lengthening the filtration cycle by about 12% as compared to direct UF. Not only was pollutant removal highest in MF-UF, but also the average permeate flux was about 80% higher in this two-stage system than in direct UF. This study shows that the most effective strategy to mitigate membrane fouling is the use of MF as a pre-treatment preceding UF.

Measurement of glomerular filtration rate using dynamic magnetic resonance imaging in patients with chronic kidney disease.

PubMed

Artunc, Ferruh; Yildiz, Serdar; Boss, Andreas; Frenzel, Thomas; Schlemmer, Heinz-Peter; Schick, Fritz; Risler, Teut; Häring, Hans-Ulrich; Rossi, Cristina

2011-01-01

Determination of glomerular filtration rate (GFR) using plasma disappearance curves requires the injection of a filtration marker and repeated timed blood collections. Gadolinium-containing contrast media are excreted exclusively by glomerular filtration and could provide a novel approach to quantifying GFR using magnetic resonance (MR) imaging. The aim of this study was to demonstrate the feasibility of measuring GFR by the clearance of gadolinium-containing contrast medium in patients with chronic kidney disease (CKD). Informed consent was obtained from stable CKD patients in stages 1, 2 or 3 (n=16; 5 women, 11 men; median age 54 years). GFR was measured after a bolus injection of gadobutrol (4 mL, approximately 0.05 mmol/kg) and calculated from the washout of the signal intensity obtained over the liver. The obtained MR-GFR was compared with simultaneously measured plasma clearance of inulin and gadobutrol. Technical failure occurred in 2 patients. The mean obtained MR-GFR was 71 ± 25 (SD) mL/min per 1.73 m² and agreed well with the mean inulin-GFR (70 ± 24 mL/min per 1.73 m²). Pearson's correlation coefficient was r=0.91. The mean of the paired differences was 1 ± 10 mL/min per 1.73 m² and not significantly different from zero. GFR obtained from gadobutrol plasma clearance also agreed well with inulin-GFR and MR-GFR (r=0.92 and r=0.75, respectively). We describe a novel method of determining GFR from MR imaging using a low dose of gadobutrol in patients with reduced GFR that enables the absolute quantification of GFR after routine contrast-enhanced MR imaging.

Removal of trace metal contaminants from potable water by electrocoagulation

PubMed Central

Heffron, Joe; Marhefke, Matt; Mayer, Brooke K.

2016-01-01

This study investigated the effects of four operational and environmental variables on the removal of trace metal contaminants from drinking water by electrocoagulation (EC). Removal efficiencies for five metals (arsenic, cadmium, chromium, lead and nickel) were compared under varying combinations of electrode material, post-treatment, water composition and pH. Iron electrodes out-performed aluminum electrodes in removing chromium and arsenic. At pH 6.5, aluminum electrodes were slightly more effective at removing nickel and cadmium, while at pH 8.5, iron electrodes were more effective for these metals. Regardless of electrode, cadmium and nickel removal efficiencies were higher at pH 8.5 than at pH 6.5. Post-EC treatment using membrane filtration (0.45 μm) enhanced contaminant removal for all metals but nickel. With the exception of lead, all metals exhibited poorer removal efficiencies as the ionic strength of the background electrolyte increased, particularly in the very high-solids synthetic groundwaters. Residual aluminum concentrations were lowest at pH 6.5, while iron residuals were lowest in low ionic strength waters. Both aluminum and iron residuals required post-treatment filtration to meet drinking water standards. EC with post-treatment filtration appears to effectively remove trace metal contaminants to potable water standards, but both reactor and source water parameters critically impact removal efficiency. PMID:27324564

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.

Nano sand filter with functionalized nanoparticles embedded in anodic aluminum oxide templates

PubMed Central

Phuong, NguyenThi; Andisetiawan, Anugrah; Van Lam, Do; Kim, Jeong Hwan; Choi, Doo-Sun; Whang, Kyung-Hyun; Nham, Jeasun; Lee, Yun Jung; Yoo, Yeong-Eun; Yoon, Jae Sung

2016-01-01

Since the ancient Egyptians had used sand as filter media for water purification, its principle has been inherited through generations and it is still being used now in industries. The sand filter consists of sand literally, and the voids within the sand bed are the pores for filtration. Here we present a filtration principle using nanoparticles, so that the voids between the nanoparticles can be considered as effective pores in nanoscale dimension. Anodic aluminum oxide (AAO) membrane has been used as the working template, and the nanoparticles have been injected and embedded within the pores of the AAO template. Nanoparticles with multiple sizes have been used in order to obtain smaller voids. Moreover, the nanoparticles have been functionalized, or electrically charged, with arginine/phenylalanine (RF) peptide group. In this way, filtration performance for charged particles or molecules, such as methylene blue, has been enhanced. Consequently, this study is expected to provide a new principle for fabrication of nano voids, or nano pores, and for filtration in nanoscale dimension. PMID:27876886

Nano sand filter with functionalized nanoparticles embedded in anodic aluminum oxide templates.

PubMed

Phuong, NguyenThi; Andisetiawan, Anugrah; Van Lam, Do; Kim, Jeong Hwan; Choi, Doo-Sun; Whang, Kyung-Hyun; Nham, Jeasun; Lee, Yun Jung; Yoo, Yeong-Eun; Yoon, Jae Sung

2016-11-23

Since the ancient Egyptians had used sand as filter media for water purification, its principle has been inherited through generations and it is still being used now in industries. The sand filter consists of sand literally, and the voids within the sand bed are the pores for filtration. Here we present a filtration principle using nanoparticles, so that the voids between the nanoparticles can be considered as effective pores in nanoscale dimension. Anodic aluminum oxide (AAO) membrane has been used as the working template, and the nanoparticles have been injected and embedded within the pores of the AAO template. Nanoparticles with multiple sizes have been used in order to obtain smaller voids. Moreover, the nanoparticles have been functionalized, or electrically charged, with arginine/phenylalanine (RF) peptide group. In this way, filtration performance for charged particles or molecules, such as methylene blue, has been enhanced. Consequently, this study is expected to provide a new principle for fabrication of nano voids, or nano pores, and for filtration in nanoscale dimension.

Nano sand filter with functionalized nanoparticles embedded in anodic aluminum oxide templates

NASA Astrophysics Data System (ADS)

Phuong, Nguyenthi; Andisetiawan, Anugrah; van Lam, Do; Kim, Jeong Hwan; Choi, Doo-Sun; Whang, Kyung-Hyun; Nham, Jeasun; Lee, Yun Jung; Yoo, Yeong-Eun; Yoon, Jae Sung

2016-11-01

Since the ancient Egyptians had used sand as filter media for water purification, its principle has been inherited through generations and it is still being used now in industries. The sand filter consists of sand literally, and the voids within the sand bed are the pores for filtration. Here we present a filtration principle using nanoparticles, so that the voids between the nanoparticles can be considered as effective pores in nanoscale dimension. Anodic aluminum oxide (AAO) membrane has been used as the working template, and the nanoparticles have been injected and embedded within the pores of the AAO template. Nanoparticles with multiple sizes have been used in order to obtain smaller voids. Moreover, the nanoparticles have been functionalized, or electrically charged, with arginine/phenylalanine (RF) peptide group. In this way, filtration performance for charged particles or molecules, such as methylene blue, has been enhanced. Consequently, this study is expected to provide a new principle for fabrication of nano voids, or nano pores, and for filtration in nanoscale dimension.

Study of different pretreatments for reverse osmosis reclamation of a petrochemical secondary effluent.

PubMed

Benito-Alcázar, C; Vincent-Vela, M C; Gozálvez-Zafrilla, J M; Lora-García, J

2010-06-15

Conventionally treated petrochemical wastewaters contain substantial quantities of hazardous pollutants. In addition, wastewater reuse is being enhanced as a consequence of the shortage of fresh water. Advanced petrochemical wastewater treatment for water reuse will reduce hazardous pollutants discharges as well as water consumption. Reverse osmosis is a suitable technology to obtain pure water. This work studies the adequacy of different pretreatments applied to a petrochemical secondary effluent to produce a suitable feeding for reverse osmosis treatment. The permeate obtained can be used in the petrochemical industry for different processes. In this work, several experiments (granulated activated carbon filtration, ultrafiltration, nanofiltration and granulated activated carbon filtration coupled with nanofiltration) were performed to improve the conventional pretreatment. Total organic carbon, chemical oxygen demand, turbidity and silt density index were used to evaluate water quality for reverse osmosis feeding. In granulated activated carbon filtration, all the measured parameters but silt density index indicated a good filtrate quality to feed reverse osmosis membranes. Although the ultrafiltration permeate obtained was suitable for reverse osmosis, nanofiltration and granulated activated carbon filtration coupled with NF provided a better effluent quality for reverse osmosis than the other pretreatments studied. Copyright 2010 Elsevier B.V. All rights reserved.

Comparison study of membrane filtration direct count and an automated coliform and Escherichia coli detection system for on-site water quality testing.

PubMed

Habash, Marc; Johns, Robert

2009-10-01

This study compared an automated Escherichia coli and coliform detection system with the membrane filtration direct count technique for water testing. The automated instrument performed equal to or better than the membrane filtration test in analyzing E. coli-spiked samples and blind samples with interference from Proteus vulgaris or Aeromonas hydrophila.

Modified dixon‐based renal dynamic contrast‐enhanced MRI facilitates automated registration and perfusion analysis

PubMed Central

Leiner, Tim; Vink, Eva E.; Blankestijn, Peter J.; van den Berg, Cornelis A.T.

2017-01-01

Purpose Renal dynamic contrast‐enhanced (DCE) MRI provides information on renal perfusion and filtration. However, clinical implementation is hampered by challenges in postprocessing as a result of misalignment of the kidneys due to respiration. We propose to perform automated image registration using the fat‐only images derived from a modified Dixon reconstruction of a dual‐echo acquisition because these provide consistent contrast over the dynamic series. Methods DCE data of 10 hypertensive patients was used. Dual‐echo images were acquired at 1.5 T with temporal resolution of 3.9 s during contrast agent injection. Dixon fat, water, and in‐phase and opposed‐phase (OP) images were reconstructed. Postprocessing was automated. Registration was performed both to fat images and OP images for comparison. Perfusion and filtration values were extracted from a two‐compartment model fit. Results Automatic registration to fat images performed better than automatic registration to OP images with visible contrast enhancement. Median vertical misalignment of the kidneys was 14 mm prior to registration, compared to 3 mm and 5 mm with registration to fat images and OP images, respectively (P = 0.03). Mean perfusion values and MR‐based glomerular filtration rates (GFR) were 233 ± 64 mL/100 mL/min and 60 ± 36 mL/minute, respectively, based on fat‐registered images. MR‐based GFR correlated with creatinine‐based GFR (P = 0.04) for fat‐registered images. For unregistered and OP‐registered images, this correlation was not significant. Conclusion Absence of contrast changes on Dixon fat images improves registration in renal DCE MRI and enables automated postprocessing, resulting in a more accurate estimation of GFR. Magn Reson Med 80:66–76, 2018. © 2017 The Authors Magnetic Resonance in Medicine published by Wiley Periodicals, Inc. on behalf of International Society for Magnetic Resonance in Medicine. This is an open access article under the terms of the Creative Commons Attribution NonCommercial License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited and is not used for commercial purposes. PMID:29134673

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.

Object-oriented Persistent Homology

PubMed Central

Wang, Bao; Wei, Guo-Wei

2015-01-01

Persistent homology provides a new approach for the topological simplification of big data via measuring the life time of intrinsic topological features in a filtration process and has found its success in scientific and engineering applications. However, such a success is essentially limited to qualitative data classification and analysis. Indeed, persistent homology has rarely been employed for quantitative modeling and prediction. Additionally, the present persistent homology is a passive tool, rather than a proactive technique, for classification and analysis. In this work, we outline a general protocol to construct object-oriented persistent homology methods. By means of differential geometry theory of surfaces, we construct an objective functional, namely, a surface free energy defined on the data of interest. The minimization of the objective functional leads to a Laplace-Beltrami operator which generates a multiscale representation of the initial data and offers an objective oriented filtration process. The resulting differential geometry based object-oriented persistent homology is able to preserve desirable geometric features in the evolutionary filtration and enhances the corresponding topological persistence. The cubical complex based homology algorithm is employed in the present work to be compatible with the Cartesian representation of the Laplace-Beltrami flow. The proposed Laplace-Beltrami flow based persistent homology method is extensively validated. The consistence between Laplace-Beltrami flow based filtration and Euclidean distance based filtration is confirmed on the Vietoris-Rips complex for a large amount of numerical tests. The convergence and reliability of the present Laplace-Beltrami flow based cubical complex filtration approach are analyzed over various spatial and temporal mesh sizes. The Laplace-Beltrami flow based persistent homology approach is utilized to study the intrinsic topology of proteins and fullerene molecules. Based on a quantitative model which correlates the topological persistence of fullerene central cavity with the total curvature energy of the fullerene structure, the proposed method is used for the prediction of fullerene isomer stability. The efficiency and robustness of the present method are verified by more than 500 fullerene molecules. It is shown that the proposed persistent homology based quantitative model offers good predictions of total curvature energies for ten types of fullerene isomers. The present work offers the first example to design object-oriented persistent homology to enhance or preserve desirable features in the original data during the filtration process and then automatically detect or extract the corresponding topological traits from the data. PMID:26705370

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.~parvum, Giardia lamblia and proposed surrogates such as B.~subtilis, detailed characterization of site hydrogeology, geochemistry, and water quality (MPA, particles, TOC, ionic strength) are underway. Particle counts are being measured in the bank filtrate to compare particle breakthrough with breakthrough of B.~subtilis spores. Particle counting has been suggested by some regulatory bodies as a real-time measure of in situ filtration performance; however, particle counting is a limited tool for assessing the efficacy of pathogen removal by in situ filtration because it is incapable of identifying discrete particles and can fail to detect microorganisms with refraction indexes close to that of water. Preliminary B.~subtilis removal data from the full scale RBF well and preliminary site characterization, particle count, and B.~subtilis removal data from the RBF test site are presented.

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.

Fluorescence-enhanced europium complexes for the assessment of renal function

NASA Astrophysics Data System (ADS)

Chinen, Lori K.; Galen, Karen P.; Kuan, K. T.; Dyszlewski, Mary E.; Ozaki, Hiroaki; Sawai, Hiroaki; Pandurangi, Raghootama S.; Jacobs, Frederick G.; Dorshow, Richard B.; Rajagopalan, Raghavan

2008-02-01

Real-time, non-invasive assessment of glomerular filtration rate (GFR) is essential not only for monitoring critically ill patients at the bedside, but also for staging and monitoring patients with chronic kidney disease. In our pursuit to develop exogenous luminescent probes for dynamic optical monitoring of GFR, we have prepared and evaluated Eu 3+ complexes of several diethylenetriamine pentaacetate (DTPA)-monoamide ligands bearing molecular "antennae" to enhance metal fluorescence via the intramolecular ligand-metal fluorescence resonance energy transfer (FRET) process. The results show that Eu-DTPA-monoamide complex 13a, which contains a quinoxanlinyl antenna, exhibits large (c.a. 2700-fold) Eu 3+ fluorescence enhancement over Eu-DTPA (4c). Indeed, complex 13a exhibits the highest fluorescent enhancement observed thus far in the DTPA-type metal complexes. The renal clearance profile of the corresponding radioactive 111In complex 13c is similar to that of 111In-DTPA, albeit 13c clears slower than 111In-DTPA. The biodistribution data indicates that 13c, and, by inference, 13a clear via a complex mechanism that includes glomerular filtration.

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 the Ecological Society of America.

Ferric reductase activity of low molecular weight human milk fraction is associated with enhanced iron solubility and uptake in Caco-2 cells.

PubMed

Pullakhandam, Raghu; Nair, Madhavan Krishnapillai; Kasula, Sunanda; Kilari, Sreenivasulu; Thippande, Tippeswamy Gowda

2008-09-19

It is known that the fractional absorption of extrinsic iron from human milk is higher in infants and adults. A low molecular weight milk fraction has been proposed to increase the bioavailability of iron from human milk. Nevertheless, the mechanisms remained elusive. Here in we demonstrate ferric reductase activity (Km7.73x10(-6)M) in low molecular weight human milk fraction (10kF, filtrate derived from ultra filtration of milk whey through 10kDa cutoff membrane), which increased ferric iron solubility and iron uptake in Caco-2 cells. The 10kF fraction was as effective as ascorbic acid (1:20 iron to ascorbic acid) in increasing the ferric iron solubility and uptake in Caco-2 cells. Further, gel filtration chromatography on peptide column led to co-elution of ferric reductase and iron solubilization activities at an apparent molecular mass of <1500Da. Interestingly, only these fractions containing ferric reductase activity also stimulated the uptake of iron in Caco-2 cells. Thus, it is concluded that human milk possesses ferric reductase activity and is associated with ferric iron solubilization and enhanced absorption.

Determination of the glomerular filtration rate (GFR): methodological problems, age-dependence, consequences of various surgical interventions, and the influence of different drugs and toxic substances.

PubMed

Fleck, C

1999-01-01

Determinations of renal clearance of fluorescein isothiocyanate (FITC)-inulin were used for assessing the glomerular filtration rate (GFR) in rats and to characterize factors influencing the glomerular filtration capacity. In anesthetized rats, GFR develops after birth up to day 30. Thereafter, GFR remains relatively constant for up to 3 months of age and drops continuously until the 8th month. GFR can be determined in utero, already one day before birth, however, only at a very low level. It increases significantly on the first day of life. Even at this time the effect of furosemide on GFR can be proven. After reduction of renal mass, GFR is decreased in dependence on the extent of kidney tissue removal. However, within 2 days after unilateral nephrectomy (NX) or one week after 5/6 NX, GFR reaches values about 3/4 of the controls with two intact kidneys. Furthermore, the compensation of GFR after renal ischemia reaches 80% of baseline values after one week. On the other hand, GFR is enhanced after bile duct ligation as a model of hepato-renal failure. It has been shown in previous experiments that pretreatment with hormones can stimulate renal tubular transport processes. Pretreatment with dexamethasone or triiodothyronine after 5/6 NX improves glomerular filtration capacity whereas in animals with ligated bile ducts dexamethasone seems to prevent the increase in GFR. After subchronic treatment with epidermal growth factor (EGF) GFR is significantly reduced. A continuous infusion of amino acids does not change GFR in the controls but enhances the filtration capacity in EGF-treated rats. But immediately after bolus injection of amino acids GFR also increases significantly in the controls. Diuretics such as furosemide, most nephrotoxic agents (cyclosporine A [CsA], heavy metals) and imidazole reduce the GFR significantly. Diltiazem reported to act nephroprotectively in CsA nephrotoxicity in human beings was without beneficial effect in rats. This could be due to species differences in GFR because the rat is one of the species with the highest glomerular filtration capacity.

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.

40 CFR 141.520 - Is my system subject to the updated watershed control requirements?

Code of Federal Regulations, 2010 CFR

2010-07-01

... AGENCY (CONTINUED) WATER PROGRAMS (CONTINUED) NATIONAL PRIMARY DRINKING WATER REGULATIONS Enhanced Filtration and Disinfection-Systems Serving Fewer Than 10,000 People Additional Watershed Control...

40 CFR 141.520 - Is my system subject to the updated watershed control requirements?

Code of Federal Regulations, 2011 CFR

2011-07-01

... AGENCY (CONTINUED) WATER PROGRAMS (CONTINUED) NATIONAL PRIMARY DRINKING WATER REGULATIONS Enhanced Filtration and Disinfection-Systems Serving Fewer Than 10,000 People Additional Watershed Control...

40 CFR 141.520 - Is my system subject to the updated watershed control requirements?

Code of Federal Regulations, 2012 CFR

2012-07-01

... AGENCY (CONTINUED) WATER PROGRAMS (CONTINUED) NATIONAL PRIMARY DRINKING WATER REGULATIONS Enhanced Filtration and Disinfection-Systems Serving Fewer Than 10,000 People Additional Watershed Control...

40 CFR 141.520 - Is my system subject to the updated watershed control requirements?

Code of Federal Regulations, 2014 CFR

2014-07-01

... AGENCY (CONTINUED) WATER PROGRAMS (CONTINUED) NATIONAL PRIMARY DRINKING WATER REGULATIONS Enhanced Filtration and Disinfection-Systems Serving Fewer Than 10,000 People Additional Watershed Control...

40 CFR 141.520 - Is my system subject to the updated watershed control requirements?

Code of Federal Regulations, 2013 CFR

2013-07-01

... AGENCY (CONTINUED) WATER PROGRAMS (CONTINUED) NATIONAL PRIMARY DRINKING WATER REGULATIONS Enhanced Filtration and Disinfection-Systems Serving Fewer Than 10,000 People Additional Watershed Control...

Changes in the transmissibility of the mid-latitude ionosphere related to the ULF (Pc1) signal

NASA Astrophysics Data System (ADS)

Prikner, Karel; Vagner, Vladimir

The frequency dependences of the transmissibility of a stratified inhomogeneous anisotropic and dissipative model of the ionosphere in relation to the ordinary Alfven wave mode, which is incident under various angles in the meridional plane, are studied. A method for the numerical modeling of the ionospheric filtration of Fourier components of the micropulsation (ULF) signals in the Pc1 range was used. The specific features of filtration in the daytime and nighttime ionosphere under low and enhanced solar activity are pointed out.

Impact of the Interaction between Aquatic Humic Substances and Algal Organic Matter on the Fouling of a Ceramic Microfiltration Membrane.

PubMed

Zhang, Xiaolei; Fan, Linhua; Roddick, Felicity A

2018-02-01

The influence of the interaction between aquatic humic substances and the algal organic matter (AOM) derived from Microcystis aeruginosa on the fouling of a ceramic microfiltration (MF) membrane was studied. AOM alone resulted in a significantly greater flux decline compared with Suwannee River humic acid (HA), and fulvic acid (FA). The mixture of AOM with HA and FA exhibited a similar flux pattern as the AOM alone in the single-cycle filtration tests, indicating the flux decline may be predominantly controlled by the AOM in the early filtration cycles. The mixtures resulted in a marked increase in irreversible fouling resistance compared with all individual feed solutions. An increase in zeta potential was observed for the mixtures (becoming more negatively charged), which was in accordance with the increased reversible fouling resistance resulting from enhanced electrostatic repulsion between the organic compounds and the negatively-charged ceramic membrane. Dynamic light scattering (DLS) and size exclusion chromatography analyses showed an apparent increase in molecular size for the AOM-humics mixtures, and some UV-absorbing molecules in the humics appeared to participate in the formation of larger aggregates with the AOM, which led to greater extent of pore plugging and hence resulted in higher irreversible fouling resistance.

Impact of the Interaction between Aquatic Humic Substances and Algal Organic Matter on the Fouling of a Ceramic Microfiltration Membrane

PubMed Central

Zhang, Xiaolei; Fan, Linhua

2018-01-01

The influence of the interaction between aquatic humic substances and the algal organic matter (AOM) derived from Microcystis aeruginosa on the fouling of a ceramic microfiltration (MF) membrane was studied. AOM alone resulted in a significantly greater flux decline compared with Suwannee River humic acid (HA), and fulvic acid (FA). The mixture of AOM with HA and FA exhibited a similar flux pattern as the AOM alone in the single-cycle filtration tests, indicating the flux decline may be predominantly controlled by the AOM in the early filtration cycles. The mixtures resulted in a marked increase in irreversible fouling resistance compared with all individual feed solutions. An increase in zeta potential was observed for the mixtures (becoming more negatively charged), which was in accordance with the increased reversible fouling resistance resulting from enhanced electrostatic repulsion between the organic compounds and the negatively-charged ceramic membrane. Dynamic light scattering (DLS) and size exclusion chromatography analyses showed an apparent increase in molecular size for the AOM-humics mixtures, and some UV-absorbing molecules in the humics appeared to participate in the formation of larger aggregates with the AOM, which led to greater extent of pore plugging and hence resulted in higher irreversible fouling resistance. PMID:29389873

Application of Sodium Ligno Sulphonate as Surfactant in Enhanced Oil Recovery and Its Feasibility Test for TPN 008 Oil

NASA Astrophysics Data System (ADS)

Prakoso, N. I.; Rochmadi; Purwono, S.

2018-04-01

One of enhanced oil recovery (EOR) methods is using surfactants to reduce the interfacial tension between the injected fluid and the oil in old reservoir. The most important principle in enhanced oil recovery process is the dynamic interaction of surfactants with crude oil. Sodium ligno sulphonate (SLS) is a commercial surfactant and already synthesized from palm solid waste by another researcher. This work aimed to apply SLS as a surfactant for EOR especially in TPN 008 oil from Pertamina Indonesia. In its application as an EOR’s surfactant, SLS shall be passed feasibility test like IFT, thermal stability, compatibility, filtration, molecular weight, density, viscosity and pH tests. The feasibility test is very important for a preliminary test prior to another advanced test. The results demonstrated that 1% SLS solution in formation water (TPN 008) had 0.254 mN/M IFT value and was also great in thermal stability, compatibility, filtration, molecular weight, viscosity and pH test.

Possibility of sludge conditioning and dewatering with rice husk biochar modified by ferric chloride.

PubMed

Wu, Yan; Zhang, Panyue; Zhang, Haibo; Zeng, Guangming; Liu, Jianbo; Ye, Jie; Fang, Wei; Gou, Xiying

2016-04-01

Rice husk biochar modified by FeCl3 (MRB-Fe) was used to enhance sludge dewaterability in this study. MRB-Fe preparation conditions and dosage were optimized. Mechanisms of MRB-Fe improving sludge dewaterability were investigated. The optimal modification conditions were: FeCl3 concentration, 3mol/L; ultrasound time, 1h. The optimal MRB-Fe dosage was 60% DS. Compared with raw sludge, the sludge specific resistance to filtration (SRF) decreased by 97.9%, the moisture content of sludge cake decreased from 96.7% to 77.9% for 6min dewatering through vacuum filtration under 0.03MPa, the SV30% decreased from 96% to 60%, and the net sludge solids yield (YN) increased by 28 times. Positive charge from iron species on MRB-Fe surface counteracted negative charge of sludge flocs to promote sludge settleability and dewaterability. Meanwhile, MRB-Fe kept a certain skeleton structure in sludge cake, making the moisture pass through easily. Using MRB-Fe, therefore, for sludge conditioning and dewatering is promising. Copyright © 2016. Published by Elsevier Ltd.

Inertial Particle Migration in the Presence of a Permeate Flow

NASA Astrophysics Data System (ADS)

Garcia, Mike; Singelton, Amanda; Pennathur, Sumita

2016-11-01

Tangential Flow Filtration (TFF) is a rapid and efficient method for the filtration and separation of suspensions of particles such as viruses, bacteria or cellular material. Enhancing the efficacy of TFF not only requires a detailed understanding of particle transport mechanisms, but also the interactions between these mechanisms and a porous wall. In this work, we numerically and experimentally explore the mechanisms of inertial particle migration in the presence of a permeate flow through the porous walls of a microchannel. Numerically, we develop a force balance model to understand the competition between permeate and inertial forces and the resultant consequences on the particle equilibrium location. Experimentally, we fabricated MEMS TFF devices to study the migration of 5, 10 and 15 µm fluorescent polystyrene beads in straight channels with perpendicular permeate flow rates up to 90% of the inlet flow rate. We find that the permeate flow directly influences the inertial focusing position of the particles, both as a function of downstream channel position and ratio of inlet to outlet flow rate. Comparing experiments to our model, we can identify inertial, viscous and a co-dominant regimes.

Combined effects of EPS and HRT enhanced biofouling on a submerged and hybrid PAC-MF membrane bioreactor.

PubMed

Khan, Mohiuddin Md Taimur; Takizawa, Satoshi; Lewandowski, Zbigniew; Habibur Rahman, M; Komatsu, Kazuhiro; Nelson, Sara E; Kurisu, Futoshi; Camper, Anne K; Katayama, Hiroyuki; Ohgaki, Shinichiro

2013-02-01

The goal of this study was to quantify and demonstrate the dynamic effects of hydraulic retention time (HRT), organic carbon and various components of extracellular polymeric substances (EPS) produced by microorganisms on the performance of submersed hollow-fiber microfiltration (MF) membrane in a hybrid powdered activated carbon (PAC)-MF membrane bioreactor (MBR). The reactors were operated continuously for 45 days to treat surface (river) water before and after pretreatment using a biofiltration unit. The real-time levels of organic carbon and the major components of EPS including five different carbohydrates (D(+) glucose and D(+) mannose, D(+) galactose, N-acetyl-D-galactosamine and D-galactose, oligosaccharides and L(-) fucose), proteins, and polysaccharides were quantified in the influent water, foulants, and in the bulk phases of different reactors. The presence of PAC extended the filtration cycle and enhanced the organic carbon adsorption and removal more than two fold. Biological filtration improved the filtrate quality and decreased membrane fouling. However, HRT influenced the length of the filtration cycle and had less effect on organic carbon and EPS component removal and/or biodegradation. The abundance of carbohydrates in the foulants on MF surfaces was more than 40 times higher than in the bulk phase, which demonstrates that the accumulation of carbohydrates on membrane surfaces contributed to the increase in transmembrane pressure significantly and PAC was not a potential adsorbent of carbohydrates. The abundance of N-acetyl-d-galactosamine and d-galactose was the highest in the foulants on membranes receiving biofilter-treated river water. Most of the biological fouling compounds were produced inside the reactors due to biodegradation. PAC inside the reactor enhanced the biodegradation of polysaccharides up to 97% and that of proteins by more than 95%. This real-time extensive and novel study demonstrates that the PAC-MF hybrid MBR is a sustainable technology for treating river water. Copyright © 2012 Elsevier Ltd. All rights reserved.

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.

40 CFR 141.561 - What happens if my system's turbidity monitoring equipment fails?

Code of Federal Regulations, 2010 CFR

2010-07-01

... (CONTINUED) WATER PROGRAMS (CONTINUED) NATIONAL PRIMARY DRINKING WATER REGULATIONS Enhanced Filtration and Disinfection-Systems Serving Fewer Than 10,000 People Individual Filter Turbidity Requirements § 141.561 What...

40 CFR 141.502 - When must my system comply with these requirements?

Code of Federal Regulations, 2010 CFR

2010-07-01

...) WATER PROGRAMS (CONTINUED) NATIONAL PRIMARY DRINKING WATER REGULATIONS Enhanced Filtration and Disinfection-Systems Serving Fewer Than 10,000 People General Requirements § 141.502 When must my system comply...

40 CFR 141.500 - General requirements.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 141.500 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) WATER PROGRAMS (CONTINUED) NATIONAL PRIMARY DRINKING WATER REGULATIONS Enhanced Filtration and Disinfection-Systems Serving... subpart constitute national primary drinking water regulations. These regulations establish requirements...

40 CFR 141.170 - General requirements.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 141.170 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) WATER PROGRAMS (CONTINUED) NATIONAL PRIMARY DRINKING WATER REGULATIONS Enhanced Filtration and Disinfection-Systems Serving... constitute national primary drinking water regulations. These regulations establish requirements for...

40 CFR 141.502 - When must my system comply with these requirements?

Code of Federal Regulations, 2012 CFR

2012-07-01

...) WATER PROGRAMS (CONTINUED) NATIONAL PRIMARY DRINKING WATER REGULATIONS Enhanced Filtration and Disinfection-Systems Serving Fewer Than 10,000 People General Requirements § 141.502 When must my system comply...

40 CFR 141.502 - When must my system comply with these requirements?

Code of Federal Regulations, 2013 CFR

2013-07-01

...) WATER PROGRAMS (CONTINUED) NATIONAL PRIMARY DRINKING WATER REGULATIONS Enhanced Filtration and Disinfection-Systems Serving Fewer Than 10,000 People General Requirements § 141.502 When must my system comply...

40 CFR 141.502 - When must my system comply with these requirements?

Code of Federal Regulations, 2014 CFR

2014-07-01

...) WATER PROGRAMS (CONTINUED) NATIONAL PRIMARY DRINKING WATER REGULATIONS Enhanced Filtration and Disinfection-Systems Serving Fewer Than 10,000 People General Requirements § 141.502 When must my system comply...

40 CFR 141.502 - When must my system comply with these requirements?

Code of Federal Regulations, 2011 CFR

2011-07-01

...) WATER PROGRAMS (CONTINUED) NATIONAL PRIMARY DRINKING WATER REGULATIONS Enhanced Filtration and Disinfection-Systems Serving Fewer Than 10,000 People General Requirements § 141.502 When must my system comply...

Airfoil-shaped micro-mixers for reducing fouling on membrane surfaces

DOEpatents

Ho, Clifford K; Altman, Susan J; Clem, Paul G; Hibbs, Michael; Cook, Adam W

2012-10-23

An array of airfoil-shaped micro-mixers that enhances fluid mixing within permeable membrane channels, such as used in reverse-osmosis filtration units, while minimizing additional pressure drop. The enhanced mixing reduces fouling of the membrane surfaces. The airfoil-shaped micro-mixer can also be coated with or comprised of biofouling-resistant (biocidal/germicidal) ingredients.

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.

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

PubMed

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

2018-06-01

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

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...

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...

Identification of novel proteins in culture filtrates of Mycobacterium bovis bacillus Calmette-Guérin in the isoelectric point range 6-11.

PubMed

Florio, Walter; Batoni, Giovanna; Esin, Semih; Bottai, Daria; Maisetta, Giuseppantonio; Pardini, Manuela; Campa, Mario

2003-05-01

Two-dimensional gel electrophoresis and mass spectrometry were used to identify proteins in the isoelectric point range 6-11 in culture filtrates of Mycobacterium bovis bacillus Calmette-Guérin (BCG). Twelve proteins were identified, three of which had not been described previously. The expression of the identified proteins was comparatively analyzed in culture filtrates of BCG in different growth phases and culture conditions. For some of these proteins, the relative protein abundance in the different culture filtrate preparations was significantly different. The differential expression of the identified proteins is discussed in relation to their putative localization and/or biological function.

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

Azhar, A.; Hamdy, M.K.

Use of ultrafiltration membrane systems in stirred cell and in thin-channel systems for immobilizing enzyme (sweet potato intrinsic and crystalline beta-amylase) in hydrolysis of sweet potato through a continuous operation mode were studied. Both the filtration rate and reducing sugars, produced as the result of enzymic hydrolysis, decreased with the filtration time. The immobilized enzymes in the thin-channel system showed a much better performance compared to that in the stirred cell system. Addition of crystalline sweet potato beta-amylase to the sweet potato increased both the filtration rate and reducing-sugars content. Alcohol fermentation of the filtrate resulted in an alcohol contentmore » of 4.2%. This represented fermentation of 95% of the sugars with an efficiency of 88%.« less

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.

Polyethersulfone - barium chloride blend ultrafiltration membranes for dye removal studies

NASA Astrophysics Data System (ADS)

Rambabu, K.; Srivatsan, N.; Gurumoorthy, Anand V. P.

2017-11-01

A series of Polyethersulfone (PES) - barium chloride (BaCl2) blend ultra filtration membrane was developed by varying the BaCl2 concentration in the dope solution. Prepared membranes were subjected to membrane characterization and their performance was studied through dye rejection tests. Morphological studies through SEM and AFM showed that the composite membranes exhibited differences in morphologies, porosities and properties due to the BaCl2 addition as compared with pristine PES membrane. Addition of the inorganic modifier enhanced the hydrophilicity and water permeability of the blend membrane system. Polymer enhanced ultrafiltration of dye solutions showed that the proposed blend system had better performance in terms of flux and rejection efficiency than the pure polymer membrane. The performance of the 2 wt% BaCl2 blend membrane was more promising for application to real time dye wastewater studies.

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.

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...

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, some methods of air filtration were significantly better than others in reducing aerosol transmission of PRRSV, and HEPA filtration was the only system that completely prevented transmission. PMID:16850938

Renal Integrin-Linked Kinase Depletion Induces Kidney cGMP-Axis Upregulation: Consequences on Basal and Acutely Damaged Renal Function

PubMed Central

Cano-Peñalver, José Luis; Griera, Mercedes; García-Jerez, Andrea; Hatem-Vaquero, Marco; Ruiz-Torres, María Piedad; Rodríguez-Puyol, Diego; de Frutos, Sergio; Rodríguez-Puyol, Manuel

2015-01-01

Soluble guanylyl cyclase (sGC) is activated by nitric oxide (NO) and produces cGMP, which activates cGMP-dependent protein kinases (PKG) and is hydrolyzed by specific phosphodiesterases (PDE). The vasodilatory and cytoprotective capacity of cGMP-axis activation results in a therapeutic strategy for several pathologies. Integrin-linked kinase (ILK), a major scaffold protein between the extracellular matrix and intracellular signaling pathways, may modulate the expression and functionality of the cGMP-axis–related proteins. We introduce ILK as a novel modulator in renal homeostasis as well as a potential target for cisplatin (CIS)-induced acute kidney injury (AKI) improvement. We used an adult mice model of depletion of ILK (cKD-ILK), which showed basal increase of sGC and PKG expressions and activities in renal cortex when compared with wildtype (WT) littermates. Twenty-four h activation of sGC activation with NO enhanced the filtration rate in cKD-ILK. During AKI, cKD-ILK maintained the cGMP-axis upregulation with consequent filtration rates enhancement and ameliorated CIS-dependent tubular epithelial-to-mesenchymal transition and inflammation and markers. To emphasize the role of cGMP-axis upregulation due to ILK depletion, we modulated the cGMP axis under AKI in vivo and in renal cultured cells. A suboptimal dose of the PDE inhibitor ZAP enhanced the beneficial effects of the ILK depletion in AKI mice. On the other hand, CIS increased contractility-related events in cultured glomerular mesangial cells and necrosis rates in cultured tubular cells; ILK depletion protected the cells while sGC blockade with ODQ fully recovered the damage. PMID:26562149

Iron-tannin-framework complex modified PES ultrafiltration membranes with enhanced filtration performance and fouling resistance.

PubMed

Fang, Xiaofeng; Li, Jiansheng; Li, Xin; Pan, Shunlong; Sun, Xiuyun; Shen, Jinyou; Han, Weiqing; Wang, Lianjun; Van der Bruggen, Bart

2017-11-01

In this work, an iron-tannin-framework (ITF) complex was introduced to a poly (ether sulfone) (PES) casting solution as a hydrophilic additive to fabricate ITF/PES ultrafiltration (UF) membranes via non-solvent-induced phase separation (NIPS). The structure and performance of the PES membranes with ITF concentrations ranging from 0 to 0.9wt.% were systematically investigated by scanning electron microscopy, water contact angle, permeability, protein rejection and fouling resistance measurements. The results indicate that the pore structure and surface properties of PES UF membranes can be regulated by incorporating the ITF complex. Compared with classical PES membranes, ITF/PES membranes were found to have an increased hydrophilicity and porosity and reduced surface pore size. Importantly, a simultaneous enhancement of permeability and separation performance was observed for the blend membranes, which indicates that the introduction of the ITF complex can break through the trade-off between permeability and selectivity of UF membranes.When the ITF content was 0.3wt.%, the permeability reached a maximum of 319.4(L/m 2 h) at 0.1MPa, which is 1.6 times higher than that of the classical PES membrane. Furthermore, the BSA rejection increased from 25.9% for the PES membrane to 95.9% for the enhanced membrane. In addition, the same membrane showed an improved fouling resistance (higher flux recovery and lower adhesion force) and stable hydrophilicity (unchanged after incubation in deionized water for 30days). The simple, green and cost-effective preparation process and the outstanding filtration performance highlight the potential of ITF/PES membranes for practical applications. Copyright © 2017 Elsevier Inc. All rights reserved.

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.

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.

Validation of serum free light chain reference ranges in primary care.

PubMed

Galvani, Luca; Flanagan, Jane; Sargazi, Mansour; Neithercut, William D

2016-05-01

The demand for measurement of serum immunoglobulin free kappa (κ) and lambda (λ) light chains has increased. The κ:λ ratio is used to assist in diagnosis/monitoring of plasma cell disorders. The binding site reference range for serum-free light chain κ:λ ratios of 0.26-1.65 was derived from healthy volunteers. Subsequently, a reference range of 0.37-3.1 for patients with chronic kidney disease has been proposed. Elevated free light chain concentrations and borderline raised free light chain ratios also may be found in polyclonal gammopathies and with other non-renal illnesses. This assessment was conducted to validate the established free light chain reference ranges in individuals from primary care. A total of 130 samples were identified from routine blood samples collected in primary care for routine biochemistry testing and estimated glomerular filtration rate calculation. The median and range of κ:λ ratios found in each estimated glomerular filtration rate group used for chronic kidney disease classification were higher than previously described. This was the case for individuals with normal or essentially normal renal function with estimated glomerular filtration rates>90, (0.58-1.76) and estimated glomerular filtration rate of 60-90 mL/min/1.73 m(2), (0.71-1.93). Individuals with estimated glomerular filtration rate 15-30, (0.72-4.50) and estimated glomerular filtration rate <15 ml/min/1.73 m(2) (0.71-4.95) also had higher values when compared to the current renal reference range of 0.37-3.10. Elevation of free light chain-κ:λ ratios may occur in the absence of a reduced renal function shown by a normal estimated glomerular filtration rate and in the presence of reduced renal function by estimated glomerular filtration rate when comparing results with the established reference ranges. Explanations include choice of analytical systems or the presence of other concurrent non-plasma cell illness. © The Author(s) 2016.

Associations of estimated glomerular filtration rate and albuminuria with mortality and renal failure by sex: a meta-analysis.

PubMed

Nitsch, Dorothea; Grams, Morgan; Sang, Yingying; Black, Corri; Cirillo, Massimo; Djurdjev, Ognjenka; Iseki, Kunitoshi; Jassal, Simerjot K; Kimm, Heejin; Kronenberg, Florian; Oien, Cecilia M; Levey, Andrew S; Levin, Adeera; Woodward, Mark; Hemmelgarn, Brenda R

2013-01-29

To assess for the presence of a sex interaction in the associations of estimated glomerular filtration rate and albuminuria with all-cause mortality, cardiovascular mortality, and end stage renal disease. Random effects meta-analysis using pooled individual participant data. 46 cohorts from Europe, North and South America, Asia, and Australasia. 2,051,158 participants (54% women) from general population cohorts (n=1,861,052), high risk cohorts (n=151,494), and chronic kidney disease cohorts (n=38,612). Eligible cohorts (except chronic kidney disease cohorts) had at least 1000 participants, outcomes of either mortality or end stage renal disease of ≥ 50 events, and baseline measurements of estimated glomerular filtration rate according to the Chronic Kidney Disease Epidemiology Collaboration equation (mL/min/1.73 m(2)) and urinary albumin-creatinine ratio (mg/g). Risks of all-cause mortality and cardiovascular mortality were higher in men at all levels of estimated glomerular filtration rate and albumin-creatinine ratio. While higher risk was associated with lower estimated glomerular filtration rate and higher albumin-creatinine ratio in both sexes, the slope of the risk relationship for all-cause mortality and for cardiovascular mortality were steeper in women than in men. Compared with an estimated glomerular filtration rate of 95, the adjusted hazard ratio for all-cause mortality at estimated glomerular filtration rate 45 was 1.32 (95% CI 1.08 to 1.61) in women and 1.22 (1.00 to 1.48) in men (P(interaction)<0.01). Compared with a urinary albumin-creatinine ratio of 5, the adjusted hazard ratio for all-cause mortality at urinary albumin-creatinine ratio 30 was 1.69 (1.54 to 1.84) in women and 1.43 (1.31 to 1.57) in men (P(interaction)<0.01). Conversely, there was no evidence of a sex difference in associations of estimated glomerular filtration rate and urinary albumin-creatinine ratio with end stage renal disease risk. Both sexes face increased risk of all-cause mortality, cardiovascular mortality, and end stage renal disease with lower estimated glomerular filtration rates and higher albuminuria. These findings were robust across a large global consortium.

Temporary renal ischemia during nephron sparing surgery is associated with short-term but not long-term impairment in renal function.

PubMed

Yossepowitch, Ofer; Eggener, Scott E; Serio, Angel; Huang, William C; Snyder, Mark E; Vickers, Andrew J; Russo, Paul

2006-10-01

The emergence of laparoscopic nephron sparing surgery has rekindled interest in the impact of warm renal ischemia on renal function. To provide data with which warm renal ischemia can be compared we analyzed short-term and long-term changes in the glomerular filtration rate after temporary cold renal ischemia. In patients undergoing open nephron sparing surgery the estimated glomerular filtration rate was assessed preoperatively, early in the postoperative hospital stay, and 1 and 12 months after surgery using the abbreviated Modification of Diet in Renal Disease Study equation. We separately analyzed 70 patients with a solitary kidney and 592 with 2 functioning kidneys. The end point was the percent change from the baseline glomerular filtration rate. A linear regression model was used to test the association between the glomerular filtration rate change, and ischemia time, patient age, tumor size, estimated blood loss and intraoperative fluid administration. Median cold ischemia time was 31 minutes in patients with a solitary kidney and 35 minutes in those with 2 kidneys. Compared to patients with 2 kidneys those with a solitary kidney had a significantly lower preoperative estimated glomerular filtration rate (p < 0.001), which decreased a median of 30% during the early postoperative period, and 15% and 32% 1 and 12 months after surgery, respectively. In patients with 2 kidneys the corresponding glomerular filtration rate decreases were 16%, 13% and 14%, respectively. On multivariate analyses in each group cold ischemia duration and intraoperative blood loss were significantly associated with early glomerular filtration rate changes. However, 12 months after surgery age was the only independent predictor of a glomerular filtration rate decrease in patients with 2 kidneys. Cold renal ischemia during nephron sparing surgery is a significant determinant of the short-term postoperative glomerular filtration rate. Longer clamping time is particularly detrimental in patients with a solitary kidney but it does not appear to influence long-term renal function. Patients of advanced age may be less likely to recover from acute ischemic renal injury.

Copper speciation and binding by organic matter in copper-contaminated streamwater

USGS Publications Warehouse

Breault, R.F.; Colman, J.A.; Aiken, G.R.; McKnight, D.

1996-01-01

Fulvic acid binding sites (1.3-70 ??M) and EDTA (0.0017-0.18 ??M) accounted for organically bound Cu in seven stream samples measured by potentiometric titration. Cu was 84-99% organically bound in filtrates with 200 nM total Cu. Binding of Cu by EDTA was limited by competition from other trace metals. Water hardness was inversely related to properties of dissolved organic carbon (DOC) that enhance fulvic acid binding: DOC concentration, percentage of DOC that is fulvic acid, and binding sites per fulvic acid carbon. Dissolved trace metals, stabilized by organic binding, occurred at increased concentration in soft water as compared to hard water.

A comparative study of Sephadex, glass wool and Percoll separation techniques on sperm quality and IVF results for cryopreserved bovine semen.

PubMed

Lee, Hae-Lee; Kim, Sue-Hee; Ji, Dong-Beom; Kim, Yong-Jun

2009-09-01

The aim of this study was to compare the effects of spermatozoa separation techniques on sperm quality and in-vitro fertilization (IVF) results for cryopreserved bovine semen. Sephadex, glass wool and Percoll gradient separation techniques were used for sperm separation and sperm motility, morphology and membrane integrity were evaluated before and after separation. Also, cleavage and blastocyst developmental rate were investigated after IVF with sperm recovered by each separation technique. The motility of samples obtained by the three separation techniques were greater compared to the control samples (p < 0.05). The percentage of spermatozoa with intact plasma-membrane integrity, identified by 6-carboxyfluoresceindiacetate/ propidium iodide fluorescent staining and the hypo-osmotic swelling test, was highest in the glass wool filtration samples (p < 0.05). The cleavage and blastocyst rate of total oocytes produced from glass wool filtration samples were also higher than the control and Sephadex filtration samples (p < 0.05), but were not significantly different from Percoll separation samples. However, a significantly greater number of cleaved embryos produced by glass wool filtration developed to blastocyst stage than those produced by Percoll separation (p < 0.05). These results indicate that spermatozoa with good quality can be achieved by these three separation techniques and can be used for bovine IVF. In particular, it suggests that glass wool filtration would be the most effective method of the three for improving sperm quality and embryo production for cryopreserved bovine spermatozoa.

Water research program final report, March 15, 1970 to October 31, 1972. Separations processes

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

Minturn, R. E.

A summary article on separation by filtration is reprinted, and research is reported in the following areas: dynamic membranes, cast film membranes, concentration polarization, economic analysis; and enhanced heat transfer. (DHM)

40 CFR 141.522 - How does the State determine whether my system's watershed control requirements are adequate?

Code of Federal Regulations, 2013 CFR

2013-07-01

... WATER REGULATIONS Enhanced Filtration and Disinfection-Systems Serving Fewer Than 10,000 People... has maximized land ownership and/or controlled land use within the watershed. Disinfection Profile ...

40 CFR 141.522 - How does the State determine whether my system's watershed control requirements are adequate?

Code of Federal Regulations, 2011 CFR

2011-07-01

... WATER REGULATIONS Enhanced Filtration and Disinfection-Systems Serving Fewer Than 10,000 People... has maximized land ownership and/or controlled land use within the watershed. Disinfection Profile ...

40 CFR 141.522 - How does the State determine whether my system's watershed control requirements are adequate?

Code of Federal Regulations, 2012 CFR

2012-07-01

... WATER REGULATIONS Enhanced Filtration and Disinfection-Systems Serving Fewer Than 10,000 People... has maximized land ownership and/or controlled land use within the watershed. Disinfection Profile ...

40 CFR 141.522 - How does the State determine whether my system's watershed control requirements are adequate?

Code of Federal Regulations, 2014 CFR

2014-07-01

... WATER REGULATIONS Enhanced Filtration and Disinfection-Systems Serving Fewer Than 10,000 People... has maximized land ownership and/or controlled land use within the watershed. Disinfection Profile ...

TREATMENT AND SOLIDS MANAGEMENT

EPA Science Inventory

A variety of high-rate treatment methods show a potential to handle WWF including: physical separation with and without chemical addition (e.g., enhanced settling, fine-mesh screening, vortex separation, dual-media high-rate filtration, dissolved air flotation, activated carbon, ...

Pentachlorophenol removal from water using surfactant-enhanced filtration through low-pressure thin film composite membranes.

PubMed

Kumar, Yogesh; Popat, K M; Brahmbhatt, H; Ganguly, B; Bhattacharya, A

2008-06-15

Removal of pentachlorophenol from water is investigated using the surfactant-enhanced cross-flow membrane filtration technique in which anionic surfactant; sodium dodecyl sulfate (SDS) is the carrier of pentachlorophenol. The separation performances are studied by varying SDS concentrations (

Comparison of two filtration-elution procedures to improve the standard methods ISO 10705-1 & 2 for bacteriophage detection in groundwater, surface water and finished water samples.

PubMed

Helmi, K; Jacob, P; Charni-Ben-Tabassi, N; Delabre, K; Arnal, C

2011-09-01

To select a reliable method for bacteriophage concentration prior detection by culture from surface water, groundwater and drinking water to enhance the sensitivity of the standard methods ISO 10705-1 & 2. Artificially contaminated (groundwater and drinking water) and naturally contaminated (surface water) 1-litre samples were processed for bacteriophages detection. The spiked samples were inoculated with about 150 PFU of F-specific RNA bacteriophages and somatic coliphages using wastewater. Bacteriophage detection in the water samples was achieved using the standard method without and with a concentration step (electropositive Anodisc membrane or a pretreated electronegative Micro Filtration membrane, MF). For artificially contaminated matrices (drinking and ground waters), recovery rates using the concentration step were superior to 70% whilst analyses without concentration step mainly led to false negative results. Besides, the MF membrane presented higher performances compared with the Anodisc membrane. The concentration of a large volume of water (up to one litre) on a filter membrane avoids false negative results obtained by direct analysis as it allows detecting low number of bacteriophages in water samples. The addition of concentration step before applying the standard method could be useful to enhance the reliability of bacteriophages monitoring in water samples as bio-indicators to highlight faecal pollution. © No claim to French Government works. Letters in Applied Microbiology © 2011 The Society for Applied Microbiology.

Bacteria and virus removal effectiveness of ceramic pot filters with different silver applications in a long term experiment.

PubMed

van der Laan, H; van Halem, D; Smeets, P W M H; Soppe, A I A; Kroesbergen, J; Wubbels, G; Nederstigt, J; Gensburger, I; Heijman, S G J

2014-03-15

In 2012 more than 4 million people used a ceramic pot filter (CPF) as household water treatment system for their daily drinking water needs. In the normal production protocol most low cost filters are impregnated with a silver solution to enhance the microbial removal efficiency. The aim of this study was to determine the role of silver during the filtration and subsequent storage. Twenty-two CPFs with three different silver applications (non, only outside and both sides) were compared in a long-term loading experiment with Escherichia coli (K12 and WR1) and MS2 bacteriophages in natural challenge water under highly controlled laboratory circumstances. No significant difference in Log Removal Values were found between the filters with different silver applications. The results show that the storage time in the receptacle is the dominant parameter to reach E. coli inactivation by silver, and not the contact time during the filtration phase. The hypothesis that the absence of silver would enhance the virus removal, due to biofilm formation on the ceramic filter element, could not be confirmed. The removal effectiveness for viruses is still of major concern for the CPF. This study suggests that the ceramic pot filter characteristics, such as burnt material content, do not determine E. coli removal efficacies, but rather the contact time with silver during storage is the dominant parameter to reach E. coli inactivation. Copyright © 2013 Elsevier Ltd. All rights reserved.

Enhanced performance of microbial fuel cell with a bacteria/multi-walled carbon nanotube hybrid biofilm

NASA Astrophysics Data System (ADS)

Zhang, Peng; Liu, Jia; Qu, Youpeng; Zhang, Jian; Zhong, Yingjuan; Feng, Yujie

2017-09-01

The biofilm on the anode of a microbial fuel cell (MFC) is a vital component in system, and its formation and characteristic determines the performance of the system. In this study, a bacteria/Multi-Walled Carbon Nanotube (MWCNT) hybrid biofilm is fabricated by effectively inserting the MWCNTs into the anode biofilm via an adsorption-filtration method. This hybrid biofilm has been demonstrated to be an efficient structure for improving an anode biofilm performance. Electrochemical impedance spectroscopy (EIS) results show that the hybrid biofilm takes advantage of the conductivity and structure of MWCNT to enhance the electron transfer and substrate diffusion of the biofilm. With this hybrid biofilm, the current density, power density and coulombic efficiency are increased by 46.2%, 58.8% and 84.6%, respectively, relative to naturally grown biofilm. Furthermore, the start-up time is reduced by 53.8% compared with naturally grown biofilm. The perturbation test demonstrates that this type of hybrid biofilm exhibits strong adsorption ability and enhances the biofilm's resistance to a sudden change of substrate concentration. The superior performance of the hybrid biofilm with MWCNT ;nanowire; matrix compared with naturally grown biofilm demonstrates its great potential for boosting the performance of MFCs.

Enhanced sludge dewatering by electrofiltration. A feasibility study.

PubMed

Saveyn, H; Huybregts, L; Van der Meeren, P

2001-01-01

Sludge treatment is a major issue in today's waste water treatment. One of the problems encountered is the limiting dewaterability of mainly biological sludges, causing high final treatment costs for incineration or landfill. Although during recent years, improvements are realised in the field of dewatering, the actual dry solids content after dewatering remains at a maximum value of about 35%. In order to increase the dry solids content, the technique of electrofiltration was investigated. Electrofiltration is the combination of two known techniques, traditional pressure filtration and electroosmotic/electrophoretic dewatering. Pressure filtration is based on pressure as the driving force for dewatering a sludge. Limitations hereby lie in the clogging of the filter cloth due to the build-up of the filtercake. Electroosmotic/electrophoretic dewatering is based on an electric field to separate sludge colloid particles from the surrounding liquid by placing the sludge liquor between two oppositely charged electrodes. In this case, mobile sludge particles will move to one electrode due to their natural surface charge, and the liquid phase will be collected at the oppositely charged electrode. Combination of both techniques makes it possible to create a more homogeneous filter cake and prevent the filter from clogging, resulting in higher cake dry solids contents and shorter filtration cycles. To investigate the feasibility of this technique for the dewatering of activated sludge, a filter unit was developed for investigations on lab scale. Multiple dewatering tests were performed in which the electric parameters for electrofiltration were varied. It was derived from these experiments that very high filter cake dry solids contents (to more than 60%), and short filtration cycles were attainable by using a relatively small electric DC field. The power consumption was very low compared to the power needed to dewater sludge by thermal drying techniques. For this reason, this technique seems very promising for the dewatering of biological sludges.

Application of pulsed-magnetic field enhances non-viral gene delivery in primary cells from different origins

NASA Astrophysics Data System (ADS)

Kamau Chapman, Sarah W.; Hassa, Paul O.; Koch-Schneidemann, Sabine; von Rechenberg, Brigitte; Hofmann-Amtenbrink, Margarethe; Steitz, Benedikt; Petri-Fink, Alke; Hofmann, Heinrich; Hottiger, Michael O.

Primary cell lines are more difficult to transfect when compared to immortalized/transformed cell lines, and hence new techniques are required to enhance the transfection efficiency in these cells. We isolated and established primary cultures of synoviocytes, chondrocytes, osteoblasts, melanocytes, macrophages, lung fibroblasts, and embryonic fibroblasts. These cells differed in several properties, and hence were a good representative sample of cells that would be targeted for expression and delivery of therapeutic genes in vivo. The efficiency of gene delivery in all these cells was enhanced using polyethylenimine-coated polyMAG magnetic nanoparticles, and the rates (17-84.2%) surpassed those previously achieved using other methods, especially in cells that are difficult to transfect. The application of permanent and pulsating magnetic fields significantly enhanced the transfection efficiencies in synoviocytes, chondrocytes, osteoblasts, melanocytes and lung fibroblasts, within 5 min of exposure to these magnetic fields. This is an added advantage for future in vivo applications, where rapid gene delivery is required before systemic clearance or filtration of the gene vectors occurs.

ULTRAVIOLET DISINFECTION OF A SECONDARY EFFLUENT: MEASUREMENT OF DOSE AND EFFECTS OF FILTRATION

EPA Science Inventory

Ultraviolet (UV) disinfection of wastewater secondary effluent was investigated in a two-phase study to develop methods for measuring UV dose and to determine the effects of filtration on UV disinfection. The first phase of this study involved a pilot plant study comparing filtra...

Accelerated testing technique for evaluating performance of chemical air filters for DUV photolithographic equipment

NASA Astrophysics Data System (ADS)

Kishkovich, Oleg P.; Bolgov, Dennis; Goodwin, William

1999-06-01

In this paper, the authors discuss the requirements for chemical air filtration system used in conjunction with modern DUV photolithography equipment. Among the topics addressed are the scope of pollutants, their respective internal and external sources, and an overview of different types of filtration technologies currently in use. Key filtration parameters, including removal efficiency, service life, and spill protection capacity, are discussed and supported by actual data, reflection the total molecular base concentration in operational IC manufacturing facilities. The authors also describe a time-accelerated testing procedure for comparing and evaluating different filtration technologies and designs, and demonstrate how this three-day test procedure can reliably predict an effective filter service life up to ten years.

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

Azhar, A.; Hamdy, M.K.

Use of ultrafiltration membrane systems in stirred cell and in thin-channel systems for immobilizing enzyme (sweet potato intrinsic and crystalline /beta/-amylase) in hydrolysis of sweet potato through a continuous operation mode were studied. Both the filtration rate and reducing sugars, produced as the result of enzymatic hydrolysis, decreased with the filtration time. THe immobilized enzymes in the thin-channel system showed a much better performance compared to that in the stirred cell system. Addition of crystalline sweet potato /beta/-amylase to the sweet potato increased both the filtration rate and reducing-sugars content. Alcoholic fermentation of the filtrate resulted in an alcohol contentmore » of 4.2%. This represented fermentation of 95% of the sugars with an efficiency of 88%. 17 refs.« less

Performance of the chronic kidney disease-epidemiology study equations for estimating glomerular filtration rate before and after nephrectomy.

PubMed

Lane, Brian R; Demirjian, Sevag; Weight, Christopher J; Larson, Benjamin T; Poggio, Emilio D; Campbell, Steven C

2010-03-01

Accurate renal function determination before and after nephrectomy is essential for proper prevention and management of chronic kidney disease due to nephron loss and ischemic injury. We compared the estimated glomerular filtration rate using several serum creatinine based formulas against the measured rate based on (125)I-iothalamate clearance to determine which most accurately reflects the rate in this setting. Of 7,611 patients treated at our institution since 1975 the measured glomerular filtration rate was selectively determined before and after nephrectomy in 268 and 157, respectively. Performance of the Cockcroft-Gault, Modification of Diet in Renal Disease Study, re-expressed Modification of Diet in Renal Disease Study and Chronic Kidney Disease-Epidemiology Study equations, each of which estimates the glomerular filtration rate, were determined using serum creatinine, age, gender, weight and body surface area. The performance of serum creatinine, reciprocal serum creatinine and the 4 formulas was compared with the measured rate using Pearson's correlation, Lin's concordance coefficient and residual plots. Median serum creatinine was 1.4 mg/dl and the median measured glomerular filtration rate was 50 ml per minute per 1.73 m(2). The correlation between serum creatinine and the measured rate was poor (-0.66) compared with that of reciprocal serum creatinine (0.78) and the 4 equations (0.82 to 0.86). The Chronic Kidney Disease-Epidemiology Study equation performed with greatest precision and accuracy, and least bias of all equations. Stage 3 or greater chronic kidney disease ((125)I-iothalamate glomerular filtration rate 60 ml per minute per 1.73 m(2) or less) was present in 44% of patients with normal serum creatinine (1.4 mg/dl or less) postoperatively. Such missed diagnoses of chronic kidney disease decreased 42% using the Chronic Kidney Disease-Epidemiology Study equation. Glomerular filtration rate estimation equations outperform serum creatinine and better identify patients with perinephrectomy compromised renal function. The newly developed, serum creatinine based, Chronic Kidney Disease-Epidemiology Study equation has sufficient accuracy to render direct glomerular filtration rate measurement unnecessary before and after nephrectomy for cause in most circumstances. 2010 American Urological Association Education and Research, Inc. Published by Elsevier Inc. All rights reserved.

Solubilization of insoluble zinc compounds by Gluconacetobacter diazotrophicus and the detrimental action of zinc ion (Zn2+) and zinc chelates on root knot nematode Meloidogyne incognita.

PubMed

Saravanan, V S; Kalaiarasan, P; Madhaiyan, M; Thangaraju, M

2007-03-01

To examine the zinc (Zn) solubilization potential and nematicidal properties of Gluconacetobacter diazotrophicus. Atomic Absorption Spectrophotometer, Differential Pulse Polarography and Gas Chromatography Coupled Mass Spectrometry were used to estimate the total Zn and Zn(2+) ions and identify the organic acids present in the culture supernatants. The effect of culture filtrate of Zn-amended G. diazotrophicus PAl5 on Meloidogyne incognita in tomato was examined under gnotobiotic conditions. Gluconacetobacter diazotrophicus PAl5 effectively solubilized the Zn compounds tested and 5-ketogluconic acid was identified as the major organic acid aiding the solubilization of zinc oxide. The presence of Zn compounds in the culture filtrates of G. diazotrophicus enhanced the mortality and reduced the root penetration of M. incognita under in vitro conditions. 5-ketogluconic acid produced by G. diazotrophicus mediated the solubilization process and the available Zn(2+) ions enhanced the nematicidal activity of G. diazotrophicus against M. incognita. Zn solubilization and enhanced nematicidal activity of Zn-amended G. diazotrophicus provides the possibility of exploiting it as a plant growth promoting bacteria.

Zinc and glycerol enhance the production of nematicidal compounds in vitro and improve the biocontrol of Meloidogyne javanica in tomato by fluorescent pseudomonads.

PubMed

Siddiqui, I A; Shaukat, S S

2002-01-01

To assess the effects of various carbon and mineral sources on the nematicidal potential of biocontrol inoculants of Pseudomonas aeruginosa IE-6S+ and Ps. fluorescens CHA0 under laboratory and glasshouse conditions. Culture filtrates of strains IE-6S+ and CHA0, cultured in nutrient yeast extract broth, caused substantial mortality of the juveniles of Meloidogyne javanica. The nematicidal activities of the culture filtrates were altered after amendment with various carbon and mineral sources. Soil amendment with zinc alone or in combination with glycerol improved the biocontrol efficacy against root-knot nematode, promoted tomato plant growth and enhanced bacterial rhizosphere and endophytic colonization. Appropriate quantities of glycerol and zinc alone or in combination enhance the nematicidal activity of Ps. aeruginosa and Ps. fluorescens. Glucose reduces the activity of these bacteria against nematodes. Minerals and carbon sources are appealing because they are easy and economical to provide during liquid fermentation of inoculants or as fertilizer amendments to improve the biocontrol activity of indigenous and introduced bacteria.

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

PubMed

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

2018-06-01

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

Sediment filtration can reduce the N load of the waste water discharge - a full-scale lake experiment

NASA Astrophysics Data System (ADS)

Aalto, Sanni L.; Saarenheimo, Jatta; Karvinen, Anu; Rissanen, Antti J.; Ropponen, Janne; Juntunen, Janne; Tiirola, Marja

2016-04-01

European commission has obliged Baltic states to reduce nitrate load, which requires high investments on the nitrate removal processes and may increase emissions of greenhouse gases, e.g. N2O, in the waste water treatment plants. We used ecosystem-scale experimental approach to test a novel sediment filtration method for economical waste water N removal in Lake Keurusselkä, Finland between 2014 and 2015. By spatially optimizing the waste water discharge, the contact area and time of nitrified waste water with the reducing microbes of the sediment was increased. This was expected to enhance microbial-driven N transformation and to alter microbial community composition. We utilized 15N isotope pairing technique to follow changes in the actual and potential denitrification rates, nitrous oxide formation and dissimilatory nitrate reduction to ammonium (DNRA) in the lake sediments receiving nitrate-rich waste water input and in the control site. In addition, we investigated the connections between observed process rates and microbial community composition and functioning by using next generation sequencing and quantitative PCR. Furthermore, we estimated the effect of sediment filtration method on waste water contact time with sediment using the 3D hydrodynamic model. We sampled one year before the full-scale experiment and observed strong seasonal patterns in the process rates, which reflects the seasonal variation in the temperature-related mixing patterns of the waste water within the lake. During the experiment, we found that spatial optimization enhanced both actual and potential denitrification rates of the sediment. Furthermore, it did not significantly promote N2O emissions, or N retention through DNRA. Overall, our results indicate that sediment filtration can be utilized as a supplemental or even alternative method for the waste water N removal.

Magnetically Enhanced Solid-Liquid Separation

NASA Astrophysics Data System (ADS)

Rey, C. M.; Keller, K.; Fuchs, B.

2005-07-01

DuPont is developing an entirely new method of solid-liquid filtration involving the use of magnetic fields and magnetic field gradients. The new hybrid process, entitled Magnetically Enhanced Solid-Liquid Separation (MESLS), is designed to improve the de-watering kinetics and reduce the residual moisture content of solid particulates mechanically separated from liquid slurries. Gravitation, pressure, temperature, centrifugation, and fluid dynamics have dictated traditional solid-liquid separation for the past 50 years. The introduction of an external field (i.e. the magnetic field) offers the promise to manipulate particle behavior in an entirely new manner, which leads to increased process efficiency. Traditional solid-liquid separation typically consists of two primary steps. The first is a mechanical step in which the solid particulate is separated from the liquid using e.g. gas pressure through a filter membrane, centrifugation, etc. The second step is a thermal drying process, which is required due to imperfect mechanical separation. The thermal drying process is over 100-200 times less energy efficient than the mechanical step. Since enormous volumes of materials are processed each year, more efficient mechanical solid-liquid separations can be leveraged into dramatic reductions in overall energy consumption by reducing downstream drying requirements have a tremendous impact on energy consumption. Using DuPont's MESLS process, initial test results showed four very important effects of the magnetic field on the solid-liquid filtration process: 1) reduction of the time to reach gas breakthrough, 2) less loss of solid into the filtrate, 3) reduction of the (solids) residual moisture content, and 4) acceleration of the de-watering kinetics. These test results and their potential impact on future commercial solid-liquid filtration is discussed. New applications can be found in mining, chemical and bioprocesses.

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.

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 also determined for gabapentin, an anticonvulsant drug recently detected in drinking water resources for which suitable removal technologies are still largely unknown. Gabapentin showed poor adsorptive removal, resulting in rapid concentration increases. Whereas previous studies classified gabapentin as not readily biodegradable, sustained removal was observed after prolonged operation and points at biological elimination of gabapentin within the GAC filter. The application of GAC as filter medium was compared to direct addition of powdered activated carbon (PAC) to deep-bed filtration as a direct process alternative. Both options yielded comparable OMP removals for most compounds at similar carbon usage rates, but GAC achieved considerably higher removals for biodegradable OMPs. Based on the results, the application of GAC in combination with coagulation/filtration represents a promising alternative to powdered activated carbon and ozone for advanced wastewater treatment. Copyright © 2016 Elsevier Ltd. All rights reserved.

Albumin-associated free fatty acids induce macropinocytosis in podocytes

PubMed Central

Chung, Jun-Jae; Huber, Tobias B.; Gödel, Markus; Jarad, George; Hartleben, Björn; Kwoh, Christopher; Keil, Alexander; Karpitskiy, Aleksey; Hu, Jiancheng; Huh, Christine J.; Cella, Marina; Gross, Richard W.; Miner, Jeffrey H.; Shaw, Andrey S.

2015-01-01

Podocytes are specialized epithelial cells in the kidney glomerulus that play important structural and functional roles in maintaining the filtration barrier. Nephrotic syndrome results from a breakdown of the kidney filtration barrier and is associated with proteinuria, hyperlipidemia, and edema. Additionally, podocytes undergo changes in morphology and internalize plasma proteins in response to this disorder. Here, we used fluid-phase tracers in murine models and determined that podocytes actively internalize fluid from the plasma and that the rate of internalization is increased when the filtration barrier is disrupted. In cultured podocytes, the presence of free fatty acids (FFAs) associated with serum albumin stimulated macropinocytosis through a pathway that involves FFA receptors, the Gβ/Gγ complex, and RAC1. Moreover, mice with elevated levels of plasma FFAs as the result of a high-fat diet were more susceptible to Adriamycin-induced proteinuria than were animals on standard chow. Together, these results support a model in which podocytes sense the disruption of the filtration barrier via FFAs bound to albumin and respond by enhancing fluid-phase uptake. The response to FFAs may function in the development of nephrotic syndrome by amplifying the effects of proteinuria. PMID:25915582

[Effects of Cultivation Soil Properties on the Transport of Genetically Engineered Microorganism in Huabei Plain].

PubMed

Zhang, Jing; Liu, Ping; Liu, Chun; Chen, Xiao-xuan; Zhang, Lei

2015-12-01

The transport of genetically engineered microorganism (GEM) in the soil is considered to be the important factor influencing the enhanced bioremediation of polluted soil. The transport of an atrazine-degrading GEM and its influencing factors were investigated in the saturated cultivation soil of Huabei Plain. The results showed that horizontal infiltration was the main mechanism of GEM transport in the saturated cultivation soil. The transport process could be simulated using the filtration model. Soil properties showed significant effects on pore water flow and GEM transport in saturated soil. When particle size, porosity and sand component of the soil increased, the hydraulic conductivity constant increased and filtration coefficient of GEM decreased in saturated soil, indicating the reduced retention of GEM in the soil. An increase in infiltration flow also increased hydraulic conductivity constant in saturated soil and consequently decreased filtration coefficient of GEM. When hydraulic conductivity constants ranged from 5.02 m · d⁻¹ to 6.70 m · d⁻¹ in the saturated soil, the filtration coefficients of GEM varied from 0.105 to 0.274. There was a significantly negative correlation between them.

Effect of filter media size, mass flow rate and filtration stage number in a moving-bed granular filter on the yield and properties of bio-oil from fast pyrolysis of biomass.

PubMed

Paenpong, Chaturong; Inthidech, Sudsakorn; Pattiya, Adisak

2013-07-01

Fast pyrolysis of cassava rhizome was performed in a bench-scale fluidised-bed reactor unit incorporated with a cross-flow moving-bed granular filter. The objective of this research was to examine several process parameters including the granular size (425-1160 μm) and mass flow rate (0-12 g/min) as well as the number of the filtration stages (1-2 stages) on yields and properties of bio-oil. The results showed that the bio-oil yield decreased from 57.7 wt.% to 42.0-49.2 wt.% when increasing the filter media size, the mass flow rate and the filtration stage number. The effect of the process parameters on various properties of bio-oil is thoroughly discussed. In general, the bio-oil quality in terms of the solids content, ash content, initial viscosity, viscosity change and ageing rate could be enhanced by the hot vapour granular filtration. Therefore, bio-oil of high stability could be produced by the pyrolysis reactor configuration designed in this work. Copyright © 2013 Elsevier Ltd. All rights reserved.

New optical probes for the continuous monitoring of renal function

NASA Astrophysics Data System (ADS)

Dorshow, Richard B.; Asmelash, Bethel; Chinen, Lori K.; Debreczeny, Martin P.; Fitch, Richard M.; Freskos, John N.; Galen, Karen P.; Gaston, Kimberly R.; Marzan, Timothy A.; Poreddy, Amruta R.; Rajagopalan, Raghavan; Shieh, Jeng-Jong; Neumann, William L.

2008-02-01

The ability to continuously monitor renal function via the glomerular filtration rate (GFR) in the clinic is currently an unmet medical need. To address this need we have developed a new series of hydrophilic fluorescent probes designed to clear via glomerular filtration for use as real time optical monitoring agents at the bedside. The ideal molecule should be freely filtered via the glomerular filtration barrier and be neither reabsorbed nor secreted by the renal tubule. In addition, we have hypothesized that a low volume of distribution into the interstitial space could also be advantageous. Our primary molecular design strategy employs a very small pyrazine-based fluorophore as the core unit. Modular chemistry for functionalizing these systems for optimal pharmacokinetics (PK) and photophysical properties have been developed. Structure-activity relationship (SAR) and pharmacokinetic (PK) studies involving hydrophilic pyrazine analogues incorporating polyethylene glycol (PEG), carbohydrate, amino acid and peptide functionality have been a focus of this work. Secondary design strategies for minimizing distribution into the interstitium while maintaining glomerular filtration include enhancing molecular volume through PEG substitution. In vivo optical monitoring experiments with advanced candidates have been correlated with plasma PK for measurement of clearance and hence GFR.

40 CFR 141.540 - Who has to develop a disinfection benchmark?

Code of Federal Regulations, 2012 CFR

2012-07-01

...) WATER PROGRAMS (CONTINUED) NATIONAL PRIMARY DRINKING WATER REGULATIONS Enhanced Filtration and... significant change to your disinfection practice. Your system must consult with the State for approval before you can implement a significant disinfection practice change. ...

STORM INLET FILTRATION DEVICE

EPA Science Inventory

Five field tests were conducted to evaluate the effectiveness of the Storm and Groundwater Enhancement Systems (SAGES) device for removing contaminants from stormwater. The SAGES device is a three-stage filtering system that could be used as a best management practices (BMP) retr...

Preparation of affordable and multifunctional clay-based ceramic filter matrix for treatment of drinking water.

PubMed

Shivaraju, H Puttaiah; Egumbo, Henok; Madhusudan, P; Anil Kumar, K M; Midhun, G

2018-02-01

Affordable clay-based ceramic filters with multifunctional properties were prepared using low-cost and active ingredients. The characterization results clearly revealed well crystallinity, structural elucidation, extensive porosity, higher surface area, higher stability, and durability which apparently enhance the treatment efficiency. The filtration rates of ceramic filter were evaluated under gravity and the results obtained were compared with a typical gravity slow sand filter (GSSF). All ceramic filters showed significant filtration rates of about 50-180 m/h, which is comparatively higher than the typical GSSF. Further, purification efficiency of clay-based ceramic filters was evaluated by considering important drinking water parameters and contaminants. A significant removal potential was achieved by the clay-based ceramic filter with 25% and 30% activated carbon along with active agents. Desired drinking water quality parameters were achieved by potential removal of nitrite (98.5%), nitrate (80.5%), total dissolved solids (62%), total hardness (55%), total organic pollutants (89%), and pathogenic microorganisms (100%) using ceramic filters within a short duration. The remarkable purification and disinfection efficiencies were attributed to the extensive porosity (0.202 cm 3  g -1 ), surface area (124.61 m 2  g -1 ), stability, and presence of active nanoparticles such as Cu, TiO 2 , and Ag within the porous matrix of the ceramic filter.

Antioxidant and ACE Inhibitory Bioactive Peptides Purified from Egg Yolk Proteins

PubMed Central

Yousr, Marwa; Howell, Nazlin

2015-01-01

Protein by-products from the extraction of lecithin from egg yolk can be converted into value-added products, such as bioactive hydrolysates and peptides that have potential health enhancing antioxidant, and antihypertensive properties. In this study, the antioxidant and angiotensin converting enzyme (ACE) inhibitory activities of peptides isolated and purified from egg yolk protein were investigated. Defatted egg yolk was hydrolyzed using pepsin and pancreatin and sequentially fractionated by ultrafiltration, followed by gel filtration to produce egg yolk gel filtration fractions (EYGF). Of these, two fractions, EYGF-23 and EYGF-33, effectively inhibited the peroxides and thiobarbituric acid reactive substance (TBARS) in an oxidizing linoleic acid model system. The antioxidant mechanism involved superoxide anion and hydroxyl radicals scavenging and ferrous chelation. The presence of hydrophobic amino acids such as tyrosine (Y) and tryptophan (W), in sequences identified by LC-MS as WYGPD (EYGF-23) and KLSDW (EYGF-33), contributed to the antioxidant activity and were not significantly different from the synthetic BHA antioxidant. A third fraction (EYGF-56) was also purified from egg yolk protein by gel filtration and exhibited high ACE inhibitory activity (69%) and IC50 value (3.35 mg/mL). The SDNRNQGY peptide (10 mg/mL) had ACE inhibitory activity, which was not significantly different from that of the positive control captopril (0.5 mg/mL). In addition, YPSPV in (EYGF-33) (10 mg/mL) had higher ACE inhibitory activity compared with captopril. These findings indicated a substantial potential for producing valuable peptides with antioxidant and ACE inhibitory activity from egg yolk. PMID:26690134

Antioxidant and ACE Inhibitory Bioactive Peptides Purified from Egg Yolk Proteins.

PubMed

Yousr, Marwa; Howell, Nazlin

2015-12-07

Protein by-products from the extraction of lecithin from egg yolk can be converted into value-added products, such as bioactive hydrolysates and peptides that have potential health enhancing antioxidant, and antihypertensive properties. In this study, the antioxidant and angiotensin converting enzyme (ACE) inhibitory activities of peptides isolated and purified from egg yolk protein were investigated. Defatted egg yolk was hydrolyzed using pepsin and pancreatin and sequentially fractionated by ultrafiltration, followed by gel filtration to produce egg yolk gel filtration fractions (EYGF). Of these, two fractions, EYGF-23 and EYGF-33, effectively inhibited the peroxides and thiobarbituric acid reactive substance (TBARS) in an oxidizing linoleic acid model system. The antioxidant mechanism involved superoxide anion and hydroxyl radicals scavenging and ferrous chelation. The presence of hydrophobic amino acids such as tyrosine (Y) and tryptophan (W), in sequences identified by LC-MS as WYGPD (EYGF-23) and KLSDW (EYGF-33), contributed to the antioxidant activity and were not significantly different from the synthetic BHA antioxidant. A third fraction (EYGF-56) was also purified from egg yolk protein by gel filtration and exhibited high ACE inhibitory activity (69%) and IC50 value (3.35 mg/mL). The SDNRNQGY peptide (10 mg/mL) had ACE inhibitory activity, which was not significantly different from that of the positive control captopril (0.5 mg/mL). In addition, YPSPV in (EYGF-33) (10 mg/mL) had higher ACE inhibitory activity compared with captopril. These findings indicated a substantial potential for producing valuable peptides with antioxidant and ACE inhibitory activity from egg yolk.

Integrated photocatalytic filtration array for indoor air quality control.

PubMed

Denny, Frans; Permana, Eric; Scott, Jason; Wang, Jing; Pui, David Y H; Amal, Rose

2010-07-15

Photocatalytic and filtration technologies were integrated to develop a hybrid system capable of removing and oxidizing organic pollutants from an air stream. A fluidized bed aerosol generator (FBAG) was adapted to prepare TiO(2)-loaded ventilation filters for the photodegradation of gas phase ethanol. Compared to a manually loaded filter, the ethanol photodegradation rate constant for the FBAG coated filter increased by 361%. Additionally, the presence of the photogenerated intermediate product, acetaldehyde, was reduced and the time for mineralization to CO(2) was accelerated. These improvements were attributed to the FBAG system providing a more uniform distribution of TiO(2) particles across the filter surface leading to greater accessibility by the UV light. A dual-UV-lamp system, as opposed to a single-lamp system, enhanced photocatalytic filter performance demonstrating the importance of high light irradiance and light distribution across the filter surface. Substituting the blacklight blue lamps with a UV-light-emitting-diode (UV-LED) array led to further improvement as well as suppressed the electrical energy per order (EE/O) by a factor of 6. These improvements derived from the more uniform distribution of light irradiance as well as the higher efficiency of UV-LEDs in converting electrical energy to photons.

Development of a Repeatable Protocol to Uniformly Coat Internal Complex Geometries of Fine Featured 3D Printed Objects with Ceramic Material, including Determination of Viscosity Limits to Properly Coat Certain Pore Sizes

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

Rogers, A.

HEPA filters are commonly used in air filtration systems ranging in application from simple home systems to the more advanced networks used in research and development. Currently, these filters are most often composed of glass fibers with diameter on the order of one micron with polymer binders. These fibers, as well as the polymers used, are known to be fragile and can degrade or become extremely brittle with heat, severely limiting their use in high temperature applications. Ceramics are one promising alternative and can enhance the filtration capabilities compared to the current technology. Because ceramic materials are more thermally resistantmore » and chemically stable, there is great interest in developing a repeatable protocol to uniformly coat fine featured polymer objects with ceramic material for use as a filter. The purpose of this experiment is to determine viscosity limits that are able to properly coat certain pore sizes in 3D printed objects, and additionally to characterize the coatings themselves. Latex paint was used as a surrogate because it is specifically designed to produce uniform coatings.« less

Process cost and facility considerations in the selection of primary cell culture clarification technology.

PubMed

Felo, Michael; Christensen, Brandon; Higgins, John

2013-01-01

The bioreactor volume delineating the selection of primary clarification technology is not always easily defined. Development of a commercial scale process for the manufacture of therapeutic proteins requires scale-up from a few liters to thousands of liters. While the separation techniques used for protein purification are largely conserved across scales, the separation techniques for primary cell culture clarification vary with scale. Process models were developed to compare monoclonal antibody production costs using two cell culture clarification technologies. One process model was created for cell culture clarification by disc stack centrifugation with depth filtration. A second process model was created for clarification by multi-stage depth filtration. Analyses were performed to examine the influence of bioreactor volume, product titer, depth filter capacity, and facility utilization on overall operating costs. At bioreactor volumes <1,000 L, clarification using multi-stage depth filtration offers cost savings compared to clarification using centrifugation. For bioreactor volumes >5,000 L, clarification using centrifugation followed by depth filtration offers significant cost savings. For bioreactor volumes of ∼ 2,000 L, clarification costs are similar between depth filtration and centrifugation. At this scale, factors including facility utilization, available capital, ease of process development, implementation timelines, and process performance characterization play an important role in clarification technology selection. In the case study presented, a multi-product facility selected multi-stage depth filtration for cell culture clarification at the 500 and 2,000 L scales of operation. Facility implementation timelines, process development activities, equipment commissioning and validation, scale-up effects, and process robustness are examined. © 2013 American Institute of Chemical Engineers.

Reduction of DOM fractions and their trihalomethane formation potential in surface river water by in-line coagulation with ceramic membrane filtration.

PubMed

Rakruam, Pharkphum; Wattanachira, Suraphong

2014-03-01

This research was aimed at investigating the reduction of DOM fractions and their trihalomethane formation potential (THMFP) by in-line coagulation with 0.1 μm ceramic membrane filtration. The combination of ceramic membrane filtration with a coagulation process is an alternative technology which can be applied to enhance conventional coagulation processes in the field of water treatment and drinking water production. The Ping River water (high turbidity water) was selected as the raw surface water because it is currently the main raw water source for water supply production in the urban and rural areas of Chiang Mai Province. From the investigation, the results showed that the highest percent reductions of DOC, UV-254, and THMFP (47.6%, 71.0%, and 67.4%, respectively) were achieved from in-line coagulation with ceramic membrane filtration at polyaluminum chloride dosage 40 mg/L. Resin adsorption techniques were employed to characterize the DOM in raw surface water and filtered water. The results showed that the use of a ceramic membrane with in-line coagulation was able to most efficiently reduce the hydrophobic fraction (HPOA) (68.5%), which was then followed by the hydrophilic fraction (HPIA) (49.3%). The greater mass DOC reduction of these two fractions provided the highest THMFP reductions (55.1% and 37.2%, respectively). Furthermore, the in-line coagulation with ceramic membrane filtration was able to reduce the hydrophobic (HPOB) fraction which is characterized by high reactivity toward THM formation. The percent reduction of mass DOC and THMFP of HPOB by in-line coagulation with ceramic membrane filtration was 45.9% and 48.0%, respectively. Copyright © 2014 The Research Centre for Eco-Environmental Sciences, Chinese Academy of Sciences. Published by Elsevier B.V. All rights reserved.

ELECTRIC-FIELD-ENHANCED FABRIC FILTRATION OF ELECTRICALLY CHARGED FLYASH

EPA Science Inventory

The paper summarizes measurements in which both external electric field (applied by electrodes at the fabric surface) and flyash electrical charge (controlled by an upstream corona precharger) are independent variables in a factorial performance experiment carried out in a labora...

Surfactant studies for bench-scale operation

NASA Technical Reports Server (NTRS)

Hickey, Gregory S.; Sharma, Pramod K.

1992-01-01

A phase 2 study was initiated to investigate surfactant-assisted coal liquefaction, with the objective of quantifying the enhancement in liquid yields and product quality. This publication covers the first quarter of work. The major accomplishments were: the refurbishment of the high-pressure, high-temperature reactor autoclave, the completion of four coal liquefaction runs with Pittsburgh #8 coal, two each with and without sodium lignosulfonate surfactant, and the development of an analysis scheme for the product liquid filtrate and filter cake. Initial results at low reactor temperatures show that the addition of the surfactant produces an improvement in conversion yields and an increase in lighter boiling point fractions for the filtrate.

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.

Preliminary analysis on the water quality index (WQI) of irradiated basic filter elements

NASA Astrophysics Data System (ADS)

Arif Abu Bakar, Asyraf; Muhamad Pauzi, Anas; Aziz Mohamed, Abdul; Syima Sharifuddin, Syazrin; Mohamad Idris, Faridah

2018-01-01

Simple water filtration system is needed in times of extreme floods. Clean water for sanitation at evacuation centres is essential and its production is possible by using the famous simple filtration system consisting of empty bottle and filter elements (sands, gravels, cotton/coffee filter). This research intends to study the effects of irradiated filter elements on the filtration effectiveness through experiments. The filter elements will be irradiated with gamma and neutron radiation using the facilities available at Malaysia Nuclear Agency. The filtration effectiveness is measured using the water quality index (WQI) that is developed in this study to reflect the quality of filtered water. The WQI of the filtered water using the system with irradiated filter elements is then compared with that of the system with non-irradiated filter elements. This preliminary analysis only focus on filtration element of silica sand. Results shows very nominal variation in in WQI after filtered by non-irradiated, gamma and neutron filter element (silica sand), where the hypothesis could not be affirmed.

The Effect of Oyster Reef Morphology on Particulate Transfer in a North Carolina Tidal Creek

NASA Astrophysics Data System (ADS)

Lemon, M. G.; Posey, M.; Mallin, M.; Alphin, T.

2014-12-01

The eastern oyster (Crassostrea virginica) is a vital ecosystem engineer species, providing a number of ecosystem services that structure and maintain estuarine environments through the construction of large, hard-bottom reef complexes. Through suspension feeding, oysters clear the water column of particulates, leading to decreased suspended material and enhanced benthic pelagic coupling. Past field studies have indicated the potential importance of the physical reef structure in regulating the transfer of particulate material in the seston. In order to directly assess the existence of the physical reef effect, multiple field experiments were performed in a small tidal creek estuary along the south eastern coast of North Carolina. Comparison of clearance rates derived from two different in situ methods, one accounting for the physical structure of the oyster reef in addition to oyster filtration and one looking at oyster filtration alone, indicate that the reef structure may increase the amount of particulate removal performed by the reef by more than 4 times the removal performed by oyster filtration alone. A defaunation experiment was performed by eliminating the live component of the oyster reef and comparing particulate transfer of this defaunated transect to that of an adjacent faunated transect. The defaunated transect had reduced but not significantly lower material removal when compared to the faunated transect prior to defaunation. Results from short and long term sediment collection and flow velocity measurements indicate that the physical effect of oyster reefs is strong over short temporal scales (days) but is much smaller when evaluated over longer time periods (months). Generally, large silt and small sand sized material is permanently removed from the seston due to the interaction of oyster reef structure and tidal flows, however the transfer of small and medium sized silt grains is only slowed down by the presence of large reef complexes. This effect has important ecological implications for downstream water quality and must be accounted for when modeling water quality improvements performed by oysters.

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 after washing by either technique but hollow fiber filtration does remove cryoprotectant more rapidly than does centrifugation.

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 performed several tests to demonstrate increases in filter performance. With the proper use of filter flow conditions and filter enhancers, filter flow rates can be increased over rates currently realized today.« less

Leakage of soluble microbial products from biological activated carbon filtration in drinking water treatment plants and its influence on health risks.

PubMed

Hong, Shen; Xian-Chun, Tang; Nan-Xiang, Wu; Hong-Bin, Chen

2018-07-01

The application of ozone-biological activated carbon (O 3 -BAC) as an advanced treatment method in drinking water treatment plants (DWTPs) can help to remove organic micropollutants and further decrease the dissolved organic carbon (DOC) level in finished water. With the increase attention to microbial safety of drinking water, a pre-positioned O 3 -BAC followed by a sand filter has been implanted into DWTP located in Shanghai, China to increase the biostability of effluents. The results showed that BAC had high removal efficiencies of UV 254 , DOC and disinfection by-product formation potential (DBPFP). The removal efficiencies between pre- and post-positioned BAC filtrations were similar. Based on the analyses of fluorescence excitation-emission matrix spectrophotometry (FEEM), the generation and leakage of soluble microbial products (SMPs) were found in both two BAC filtrations on account of the increased fluorescence intensities and fluorescence regional integration (FRI) distribution of protein-like organics, as well as the enhanced biological index (BIX). The leakage of SMPs produced by metabolism of microbes during BAC process resulted in increased DBPFP yield and carcinogenic factor per unit of DOC (CF/DOC). Although BAC filtration reduced the DBPFP and CF, there still was high health risk of effluents for the production of SMPs. Therefore, the health risks for SMPs generated by BAC filtration in drinking water advanced treatment process should be addressed, especially with that at high temperature. Copyright © 2018 Elsevier Ltd. All rights reserved.

Sol-gel applications for ceramic membrane preparation

NASA Astrophysics Data System (ADS)

Erdem, I.

2017-02-01

Ceramic membranes possessing superior properties compared to polymeric membranes are more durable under severe working conditions and therefore their service life is longer. The ceramic membranes are composed of some layers. The support is the layer composed of coarser ceramic structure and responsible for mechanical durability under filtration pressure and it is prepared by consolidation of ceramic powders. The top layer is composed of a finer ceramic micro-structure mainly responsible for the separation of components present in the fluid to be filtered and sol-gel method is a versatile tool to prepare such a tailor-made ceramic filtration structure with finer pores. Depending on the type of filtration (e.g. micro-filtration, ultra-filtration, nano-filtration) aiming separation of components with different sizes, sols with different particulate sizes should be prepared and consolidated with varying precursors and preparation conditions. The coating of sol on the support layer and heat treatment application to have a stable ceramic micro-structure are also important steps determining the final properties of the top layer. Sol-gel method with various controllable parameters (e.g. precursor type, sol formation kinetics, heat treatment conditions) is a practical tool for the preparation of top layers of ceramic composite membranes with desired physicochemical properties.

Reply to “Ranking filter methods for concentrating pathogens in lake water”

USGS Publications Warehouse

Bushon, Rebecca N.; Francy, Donna S.; Gallardo, Vicente J.; Lindquist, H.D. Alan; Villegas, Eric N.; Ware, Michael W.

2013-01-01

Accurately comparing filtration methods is indeed difficult. Our method (1) and the method described by Borchardt et al. for determining recoveries are both acceptable approaches; however, each is designed to achieve a different research goal. Our study was designed to compare recoveries of multiple microorganisms in surface-water samples. Because, in practice, water-matrix effects come into play throughout filtration, concentration, and detection processes, we felt it important to incorporate those effects into the recovery results.

Removal of copper ions from aqueous solutions by means of micellar-enhanced ultrafiltration

NASA Astrophysics Data System (ADS)

Kowalska, Izabela; Klimonda, Aleksandra

2017-11-01

The aim of the study was to assess the usefulness of micellar-enhanced ultrafiltration (MEUF) for removal of copper ions from water solutions in comparison with classic ultrafiltration process. The tests were conducted in a semi-pilot membrane installation with the use of ultrafiltration module KOCH/ROMICON® at a transmembrane pressure of 0.05 MPa. The effect of concentration of copper ions on ultrafiltration process efficiency was investigated. The second part of the tests concerned the removal of copper ions by MEUF under wide range of anionic surfactant concentration (0.25, 1, and 5 CMC (critical micelle concentration)). Concentration of copper ions in model solutions was equal to 5, 20, and 50 mg Cu/L. Furthermore, the effect of surfactant leakage to the permeate side during filtration was evaluated. Conducted experiments confirmed effectiveness of MEUF in copper ions removal. For the highest copper concentration in the feed (i.e. 50 mg/L), the average concentration of copper ions in the permeate ranged from 1.2-4.7 mg Cu/L depending on surfactant concentration. During filtration experiments, UF module exhibited stable transport properties for model solutions containing copper. For the highest concentration of metal, the decrease of permeate flux did not exceed 11% after 60 minutes of filtration. In the presence of the surfactant, a slight deterioration of transport properties was observed.

Associations of estimated glomerular filtration rate and albuminuria with mortality and renal failure by sex: a meta-analysis

PubMed Central

Nitsch, Dorothea; Grams, Morgan; Sang, Yingying; Black, Corri; Cirillo, Massimo; Djurdjev, Ognjenka; Iseki, Kunitoshi; Jassal, Simerjot K; Kimm, Heejin; Kronenberg, Florian; Øien, Cecilia M; Levin, Adeera; Woodward, Mark; Hemmelgarn, Brenda R

2013-01-01

Objective To assess for the presence of a sex interaction in the associations of estimated glomerular filtration rate and albuminuria with all-cause mortality, cardiovascular mortality, and end stage renal disease. Design Random effects meta-analysis using pooled individual participant data. Setting 46 cohorts from Europe, North and South America, Asia, and Australasia. Participants 2 051 158 participants (54% women) from general population cohorts (n=1 861 052), high risk cohorts (n=151 494), and chronic kidney disease cohorts (n=38 612). Eligible cohorts (except chronic kidney disease cohorts) had at least 1000 participants, outcomes of either mortality or end stage renal disease of ≥50 events, and baseline measurements of estimated glomerular filtration rate according to the Chronic Kidney Disease Epidemiology Collaboration equation (mL/min/1.73 m2) and urinary albumin-creatinine ratio (mg/g). Results Risks of all-cause mortality and cardiovascular mortality were higher in men at all levels of estimated glomerular filtration rate and albumin-creatinine ratio. While higher risk was associated with lower estimated glomerular filtration rate and higher albumin-creatinine ratio in both sexes, the slope of the risk relationship for all-cause mortality and for cardiovascular mortality were steeper in women than in men. Compared with an estimated glomerular filtration rate of 95, the adjusted hazard ratio for all-cause mortality at estimated glomerular filtration rate 45 was 1.32 (95% CI 1.08 to 1.61) in women and 1.22 (1.00 to 1.48) in men (Pinteraction<0.01). Compared with a urinary albumin-creatinine ratio of 5, the adjusted hazard ratio for all-cause mortality at urinary albumin-creatinine ratio 30 was 1.69 (1.54 to 1.84) in women and 1.43 (1.31 to 1.57) in men (Pinteraction<0.01). Conversely, there was no evidence of a sex difference in associations of estimated glomerular filtration rate and urinary albumin-creatinine ratio with end stage renal disease risk. Conclusions Both sexes face increased risk of all-cause mortality, cardiovascular mortality, and end stage renal disease with lower estimated glomerular filtration rates and higher albuminuria. These findings were robust across a large global consortium. PMID:23360717

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.

Enhanced conductivity of reduced graphene oxide decorated with aluminium oxide nanoparticles by oxygen annealing.

PubMed

Liu, Hao; Choy, Kwang-Leong; Roe, Martin

2013-07-07

A process involving the filtration of graphene oxide (GO) dispersion through an alumina membrane, followed by oxygen annealing to synthesize alumina nanoparticles exclusively at the edges of holes or vacancies in the reduced graphene oxide (rGO) plane, is used to prepare paper-like composites with a 21% enhanced electrical conductivity. Moreover, the rGO/alumina nanocomposites have a smaller band gap and hydrophilic properties.

40 CFR 141.503 - What does subpart T require?

Code of Federal Regulations, 2012 CFR

2012-07-01

... Section 141.503 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) WATER PROGRAMS (CONTINUED) NATIONAL PRIMARY DRINKING WATER REGULATIONS Enhanced Filtration and Disinfection-Systems Serving.... These requirements are: (a) You must cover any finished water reservoir that you began to construct on...

40 CFR 141.503 - What does subpart T require?

Code of Federal Regulations, 2011 CFR

2011-07-01

... Section 141.503 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) WATER PROGRAMS (CONTINUED) NATIONAL PRIMARY DRINKING WATER REGULATIONS Enhanced Filtration and Disinfection-Systems Serving.... These requirements are: (a) You must cover any finished water reservoir that you began to construct on...

40 CFR 141.503 - What does subpart T require?

Code of Federal Regulations, 2013 CFR

2013-07-01

... Section 141.503 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) WATER PROGRAMS (CONTINUED) NATIONAL PRIMARY DRINKING WATER REGULATIONS Enhanced Filtration and Disinfection-Systems Serving.... These requirements are: (a) You must cover any finished water reservoir that you began to construct on...

40 CFR 141.503 - What does subpart T require?

Code of Federal Regulations, 2014 CFR

2014-07-01

... Section 141.503 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) WATER PROGRAMS (CONTINUED) NATIONAL PRIMARY DRINKING WATER REGULATIONS Enhanced Filtration and Disinfection-Systems Serving.... These requirements are: (a) You must cover any finished water reservoir that you began to construct on...

40 CFR 141.503 - What does subpart T require?

Code of Federal Regulations, 2010 CFR

2010-07-01

... Section 141.503 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) WATER PROGRAMS (CONTINUED) NATIONAL PRIMARY DRINKING WATER REGULATIONS Enhanced Filtration and Disinfection-Systems Serving.... These requirements are: (a) You must cover any finished water reservoir that you began to construct on...

40 CFR 141.172 - Disinfection profiling and benchmarking.

Code of Federal Regulations, 2010 CFR

2010-07-01

...) WATER PROGRAMS (CONTINUED) NATIONAL PRIMARY DRINKING WATER REGULATIONS Enhanced Filtration and Disinfection-Systems Serving 10,000 or More People § 141.172 Disinfection profiling and benchmarking. (a... 40 Protection of Environment 22 2010-07-01 2010-07-01 false Disinfection profiling and...

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.

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

Chronic Kidney Disease Epidemiology Collaboration versus Modification of Diet in Renal Disease equations for renal function evaluation in patients undergoing partial nephrectomy.

PubMed

Shikanov, Sergey; Clark, Melanie A; Raman, Jay D; Smith, Benjamin; Kaag, Matthew; Russo, Paul; Wheat, Jeffrey C; Wolf, J Stuart; Huang, William C; Shalhav, Arieh L; Eggener, Scott E

2010-11-01

A novel equation, the Chronic Kidney Disease Epidemiology Collaboration, has been proposed to replace the Modification of Diet in Renal Disease for estimated glomerular filtration rate due to higher accuracy, particularly in the setting of normal renal function. We compared these equations in patients with 2 functioning kidneys undergoing partial nephrectomy. We assembled a cohort of 1,158 patients from 5 institutions who underwent partial nephrectomy between 1991 and 2009. Only subjects with 2 functioning kidneys were included in the study. The end points were baseline estimated glomerular filtration rate, last followup estimated glomerular filtration rate (3 to 18 months), absolute and percent change estimated glomerular filtration rate ([absolute change/baseline] × 100%), and proportion of newly developed chronic kidney disease stage III. The agreement between the equations was evaluated using Bland-Altman plots and the McNemar test for paired observations. Mean baseline estimated glomerular filtration rate derived from the Modification of Diet in Renal Disease and Chronic Kidney Disease Epidemiology Collaboration equations were 73 and 77 ml/minute/1.73 m(2), respectively, and following surgery were 63 and 67 ml/minute/1.73 m(2), respectively. Mean percent change estimated glomerular filtration rate was -12% for both equations (p = 0.2). The proportion of patients with newly developed chronic kidney disease stage III following surgery was 32% and 25%, according to the Modification of Diet in Renal Disease and Chronic Kidney Disease Epidemiology Collaboration equations, respectively (p = 0.001). For patients with 2 functioning kidneys undergoing partial nephrectomy the Chronic Kidney Disease Epidemiology Collaboration equation provides slightly higher glomerular filtration rate estimates compared to the Modification of Diet in Renal Disease equation, with 7% fewer patients categorized as having chronic kidney disease stage III or worse. Copyright © 2010 American Urological Association Education and Research, Inc. Published by Elsevier Inc. All rights reserved.

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

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

Wunderle, K; Wayne State University School of Medicine, Detroit, MI; Godley, A

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

Reduction in cryptosporidiosis associated with introduction of enhanced filtration of drinking water at Loch Katrine, Scotland.

PubMed

Pollock, K G J; Young, D; Robertson, C; Ahmed, S; Ramsay, C N

2014-01-01

Previous evidence has suggested an association between cryptosporidiosis and consumption of unfiltered drinking water from Loch Katrine in Scotland. Before September 2007, the water was only micro-strained and chlorinated; however, since that time, coagulation and rapid gravity filtration have been installed. In order to determine risk factors associated with cryptosporidiosis, including drinking water, we analysed data on microbiologically confirmed cases of cryptosporidiosis from 2004 to 2010. We identified an association between the incidence of cryptosporidiosis and unfiltered Loch Katrine drinking water supplied to the home (odds ratio 1.86, 95% confidence interval 1.11-3.11, P = 0.019). However, while filtration appears to be associated with initially reduced rates of cryptosporidiosis, evidence suggests it may paradoxically make those consumers more susceptible to other transmission routes in the long-term. These findings support implementation of similar treatment for other unfiltered drinking-water supplies, as a means of reducing cryptosporidiosis associated with drinking water.

Dual-energy dual-source CT with additional spectral filtration can improve the differentiation of non-uric acid renal stones: An ex vivo phantom study

PubMed Central

Qu, Mingliang; Ramirez Giraldo, Juan C.; Leng, Shuai; Williams, James C.; Vrtiska, Terri J.; Lieske, John C.; McCollough, Cynthia H.

2014-01-01

Purpose To determine the ex vivo ability of dual-energy, dual-source computed tomography (DE-DSCT) with additional tin filtration to differentiate between five groups of human renal stone types. Methods Forty-three renal stones of ten types were categorized into five primary groups based on effective atomic numbers, which were calculated as the weighted average of the atomic numbers of constituent atoms. Stones were embedded in porcine kidneys and placed in a 35cm water phantom. DE-DSCT scans were performed with and without tin filtration at 80/140kV. The CT number ratio [CTR=CT(low)/CT(high)] was calculated on a volumetric voxel-by-voxel basis for each stone. Statistical analysis was performed and receiver operating characteristic (ROC) curves were plotted to compare the difference in CTR with and without tin filtration, and to measure the discrimination between stone groups. Results CTR of non-uric acid stones increased on average by 0.17 (range 0.03–0.36) with tin filtration. The CTR values for non-uric acid stone groups were not significantly different (p>0.05) between any of the two adjacent groups without tin filtration. Use of the additional tin filtration on the high-energy x-ray tube significantly improved the separation of non-uric acid stone types by CTR (p<0.05). The area under the ROC curve increased from 0.78–0.84 without fin filtration to 0.89–0.95 with tin filtration. Conclusion Our results demonstrated better separation between different stone types when additional tin filtration was used on DE-DSCT. The increased spectral separation allowed a 5-group stone classification scheme. Some overlapping between particular stone types still exists, including brushite and calcium oxalate. PMID:21606290

Comparative studies of various hyaluronic acids produced by microbial fermentation for potential topical ophthalmic applications.

PubMed

Guillaumie, Fanny; Furrer, Pascal; Felt-Baeyens, Olivia; Fuhlendorff, Birgit L; Nymand, Søren; Westh, Peter; Gurny, Robert; Schwach-Abdellaoui, Khadija

2010-03-15

This work presents a comparative study of various hyaluronic acids (HA) produced by fermentation of either Bacillus subtilis or Streptococcus towards the selection of an optimal molecular weight (MW) HA for the preparation of topical ophthalmic formulations. The influence of HA MW on water binding capacity, sterile filtration, rheological properties, precorneal residence time and ocular tolerance of ophthalmic solutions was investigated. Molecular weight did not affect hydration of hyaluronic acid according to differential scanning calorimetry (DSC). In general, medium MW HA (0.6-1 MDa) resulted in solutions that were superior in terms of sterile filtration and kinematic viscosity requirements compared to high MW HA (>1 MDa). Moreover, all HA-based solutions exhibited well-defined viscoelastic properties that depend on MW. Gamma scintigraphic data indicated that HA MW at 0.1% concentration (w/v) and HA origin did not significantly affect the corneal residence time on rabbit eyes. A 0.3% solution of high MW HA had a prolonged residence time in the precorneal area compared to a medium MW HA at the same concentration. Finally, an in vivo ocular irritation test based on confocal laser scanning ophthalmoscopy (CLSO) conclusively showed the excellent tolerance of both Bacillus-derived HA and Streptococcus-derived HA after topical instillation onto the corneal surface. Overall, this comprehensive work highlights the superiority of medium MW hyaluronic acid for topical ophthalmic formulations based on their physico-chemical and biological properties, tolerance and handling. Such solutions are expected to enhance tear film stability, to allow for maximum comfort, and to exhibit high residence times, while being biocompatible and easy to sterile filter. (c) 2009 Wiley Periodicals, Inc.

Further evaluation of the NWF filter for the purification of Plasmodium vivax-infected erythrocytes.

PubMed

Li, Jiangyan; Tao, Zhiyong; Li, Qian; Brashear, Awtum; Wang, Ying; Xia, Hui; Fang, Qiang; Cui, Liwang

2017-05-17

Isolation of Plasmodium-infected red blood cells (iRBCs) from clinical blood samples is often required for experiments, such as ex vivo drug assays, in vitro invasion assays and genome sequencing. Current methods for removing white blood cells (WBCs) from malaria-infected blood are time-consuming or costly. A prototype non-woven fabric (NWF) filter was developed for the purification of iRBCs, which showed great efficiency for removing WBCs in a pilot study. Previous work was performed with prototype filters optimized for processing 5-10 mL of blood. With the commercialization of the filters, this study aims to evaluate the efficiency and suitability of the commercial NWF filter for the purification of Plasmodium vivax-infected RBCs in smaller volumes of blood and to compare its performance with that of Plasmodipur ® filters. Forty-three clinical P. vivax blood samples taken from symptomatic patients attending malaria clinics at the China-Myanmar border were processed using the NWF filters in a nearby field laboratory. The numbers of WBCs and iRBCs and morphology of P. vivax parasites in the blood samples before and after NWF filtration were compared. The viability of P. vivax parasites after filtration from 27 blood samples was examined by in vitro short-term culture. In addition, the effectiveness of the NWF filter for removing WBCs was compared with that of the Plasmodipur ® filter in six P. vivax blood samples. Filtration of 1-2 mL of P. vivax-infected blood with the NWF filter removed 99.68% WBCs. The densities of total iRBCs, ring and trophozoite stages before and after filtration were not significantly different (P > 0.05). However, the recovery rates of schizont- and gametocyte-infected RBCs, which were minor parasite stages in the clinical samples, were relatively low. After filtration, the P. vivax parasites did not show apparent morphological changes. Culture of 27 P. vivax-infected blood samples after filtration showed that parasites successfully matured into the schizont stage. The WBC removal rates and iRBC recovery rates were not significantly different between the NWF and Plasmodipur ® filters (P > 0.05). When tested with 1-2 mL of P. vivax-infected blood, the NWF filter could effectively remove WBCs and the recovery rates for ring- and trophozoite-iRBCs were high. P. vivax parasites after filtration could be successfully cultured in vitro to reach maturity. The performance of the NWF and Plasmodipur ® filters for removing WBCs and recovering iRBCs was comparable.

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.

40 CFR 141.541 - What are significant changes to disinfection practice?

Code of Federal Regulations, 2010 CFR

2010-07-01

... disinfection practice? 141.541 Section 141.541 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) WATER PROGRAMS (CONTINUED) NATIONAL PRIMARY DRINKING WATER REGULATIONS Enhanced Filtration and Disinfection-Systems Serving Fewer Than 10,000 People Disinfection Benchmark § 141.541 What are significant...

Effects on Occupants of Enhanced Particle Filtration in a non-problem office environment: A Double-Blind Crossover Intervention Study

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

Mendell, M.J.; Fisk, W.J.; Petersen, M.

1998-06-15

Workers in indoor environments often complain of symptoms, such as eye and nose irritation, headache, and fatigue, which improve away from work. Exposures causing such complaints, sometimes referred to as sick building syndrome, generally have not been identified. Evidence suggests these worker symptoms are related to chemical, microbiological, physical, and psychosocial exposures not well characterized by current methods. Most research in this area has involved cross-sectional studies, which are limited in their abilities to show causal connections. Experimental studies have also been conducted which, by changing one factor at a time to isolate its effects, can demonstrate benefits of anmore » environmental intervention even before exposures or mechanisms are understood. This study was prompted by evidence that particulate contaminants may be related to acute occupant symptoms and discomfort. The objective was to assess, with a double-blind, double crossover intervention design, whether improved removal of small airborne particles by enhanced central filtration would reduce symptoms and discomfort.« less

Epiphytic pink-pigmented methylotrophic bacteria enhance germination and seedling growth of wheat (Triticum aestivum) by producing phytohormone.

PubMed

Meena, Kamlesh K; Kumar, Manish; Kalyuzhnaya, Marina G; Yandigeri, Mahesh S; Singh, Dhananjaya P; Saxena, Anil K; Arora, Dilip K

2012-05-01

Methylotrophic bacteria were isolated from the phyllosphere of different crop plants such as sugarcane, pigeonpea, mustard, potato and radish. The methylotrophic isolates were differentiated based on growth characteristics and colony morphology on methanol supplemented ammonium mineral salts medium. Amplification of the mxaF gene helped in the identification of the methylotrophic isolates as belonging to the genus Methylobacterium. Cell-free culture filtrates of these strains enhanced seed germination of wheat (Triticum aestivum) with highest values of 98.3% observed using Methylobacterium sp. (NC4). Highest values of seedling length and vigour were recorded with Methylobacterium sp. (NC28). HPLC analysis of production by bacterial strains ranged from 1.09 to 9.89 μg ml(-1) of cytokinins in the culture filtrate. Such cytokinin producing beneficial methylotrophs can be useful in developing bio-inoculants through co-inoculation of pink-pigmented facultative methylotrophs with other compatible bacterial strains, for improving plant growth and productivity, in an environment-friendly manner.

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.

Effect of ozone and granular activated coal (GAC) on the bioactivity of drinking water.

PubMed

Sallanko, Jarmo; Iivari, Pekka; Heiska, Eeva

2009-02-15

In this research, the appearance of easily biodegradable organic material in ozonation and granular activated coal (GAC) filtration was studied. The amount of bioactivity was measured by conventional AOC analyses used in two different modes and also using quite a new growth potential (GP) method. GAC filtration without ozone doubled the amount of AOC of the chemically treated surface water, whereas by ozonation with GAC filtration it was possible to halve the amount of the AOC. The measurement of GP was noticeably simpler than measuring AOC, but for wider use more parallel studies are needed for the comparability of the results of the analysis.

The improvement of competitive saprophytic capabilities of Trichoderma species through the use of chemical mutagens.

PubMed

Rashmi, Singh; Maurya, Sudarshan; Upadhyay, Ram Sanmukh

2016-01-01

The antagonistic potential of Trichoderma strains was assayed by studying the effect of their culture filtrate on the radial growth of Sclerotium rolfsii, the causal agent of chickpea collar rot. Trichoderma harzianum-1432 (42.2%) and Trichoderma atroviride (40.3%) were found to be strong antagonists. To enhance their antagonistic potential, mutagenesis of these two selected strains was performed. Two mutants, Th-m1 and T. atroviride m1, were found to be more effective than their parent strains. The enzymatic activities of the selected parent and mutant strains were assayed, and although both mutants were found to have enhanced enzymatic activities compared to their respective parent strains, Th-m1 possessed the maximum cellulase (5.69U/mL) and β-1,3-glucanase activity (61.9U/mL). Th-m1 also showed high competitive saprophytic ability (CSA) among all of the selected parent and mutant strains, and during field experiments, Th-m1 was found to successfully possess enhanced disease control (82.9%). Copyright © 2015 Sociedade Brasileira de Microbiologia. Published by Elsevier Editora Ltda. All rights reserved.

The improvement of competitive saprophytic capabilities of Trichoderma species through the use of chemical mutagens

PubMed Central

Rashmi, Singh; Maurya, Sudarshan; Upadhyay, Ram Sanmukh

2016-01-01

The antagonistic potential of Trichoderma strains was assayed by studying the effect of their culture filtrate on the radial growth of Sclerotium rolfsii, the causal agent of chickpea collar rot. Trichoderma harzianum-1432 (42.2%) and Trichoderma atroviride (40.3%) were found to be strong antagonists. To enhance their antagonistic potential, mutagenesis of these two selected strains was performed. Two mutants, Th-m1 and T. atroviride m1, were found to be more effective than their parent strains. The enzymatic activities of the selected parent and mutant strains were assayed, and although both mutants were found to have enhanced enzymatic activities compared to their respective parent strains, Th-m1 possessed the maximum cellulase (5.69 U/mL) and β-1,3-glucanase activity (61.9 U/mL). Th-m1 also showed high competitive saprophytic ability (CSA) among all of the selected parent and mutant strains, and during field experiments, Th-m1 was found to successfully possess enhanced disease control (82.9%). PMID:26887221

40 CFR 141.541 - What are significant changes to disinfection practice?

Code of Federal Regulations, 2012 CFR

2012-07-01

... 40 Protection of Environment 24 2012-07-01 2012-07-01 false What are significant changes to... (CONTINUED) WATER PROGRAMS (CONTINUED) NATIONAL PRIMARY DRINKING WATER REGULATIONS Enhanced Filtration and... changes to disinfection practice? Significant changes to disinfection practice include: (a) Changes to the...

40 CFR 141.541 - What are significant changes to disinfection practice?

Code of Federal Regulations, 2014 CFR

2014-07-01

... 40 Protection of Environment 23 2014-07-01 2014-07-01 false What are significant changes to... (CONTINUED) WATER PROGRAMS (CONTINUED) NATIONAL PRIMARY DRINKING WATER REGULATIONS Enhanced Filtration and... changes to disinfection practice? Significant changes to disinfection practice include: (a) Changes to the...

40 CFR 141.541 - What are significant changes to disinfection practice?

Code of Federal Regulations, 2013 CFR

2013-07-01

... 40 Protection of Environment 24 2013-07-01 2013-07-01 false What are significant changes to... (CONTINUED) WATER PROGRAMS (CONTINUED) NATIONAL PRIMARY DRINKING WATER REGULATIONS Enhanced Filtration and... changes to disinfection practice? Significant changes to disinfection practice include: (a) Changes to the...

40 CFR 141.541 - What are significant changes to disinfection practice?

Code of Federal Regulations, 2011 CFR

2011-07-01

... 40 Protection of Environment 23 2011-07-01 2011-07-01 false What are significant changes to... (CONTINUED) WATER PROGRAMS (CONTINUED) NATIONAL PRIMARY DRINKING WATER REGULATIONS Enhanced Filtration and... changes to disinfection practice? Significant changes to disinfection practice include: (a) Changes to the...

40 CFR 141.543 - How is the disinfection benchmark calculated?

Code of Federal Regulations, 2010 CFR

2010-07-01

...) WATER PROGRAMS (CONTINUED) NATIONAL PRIMARY DRINKING WATER REGULATIONS Enhanced Filtration and Disinfection-Systems Serving Fewer Than 10,000 People Disinfection Benchmark § 141.543 How is the disinfection... 40 Protection of Environment 22 2010-07-01 2010-07-01 false How is the disinfection benchmark...

40 CFR 141.522 - How does the State determine whether my system's watershed control requirements are adequate?

Code of Federal Regulations, 2010 CFR

2010-07-01

... Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) WATER PROGRAMS (CONTINUED) NATIONAL PRIMARY DRINKING WATER REGULATIONS Enhanced Filtration and Disinfection-Systems Serving Fewer Than 10,000 People... has maximized land ownership and/or controlled land use within the watershed. Disinfection Profile ...

Sensitive enumeration of Listeria monocytogenes and other Listeria species in various naturally contaminated matrices using a membrane filtration method.

PubMed

Barre, Léna; Brasseur, Emilie; Doux, Camille; Lombard, Bertrand; Besse, Nathalie Gnanou

2015-06-01

For the enumeration of Listeria monocytogenes (L. monocytogenes) in food, a sensitive enumeration method has been recently developed. This method is based on a membrane filtration of the food suspension followed by transfer of the filter on a selective medium to enumerate L. monocytogenes. An evaluation of this method was performed with several categories of foods naturally contaminated with L. monocytogenes. The results obtained with this technique were compared with those obtained from the modified reference EN ISO 11290-2 method for the enumeration of L. monocytogenes in food, and are found to provide more precise results. In most cases, the filtration method enabled to examine a greater quantity of food thus greatly improving the sensitivity of the enumeration. However, it was hardly applicable to some food categories because of filtration problems and background microbiota interference. Copyright © 2014 Elsevier Ltd. All rights reserved.

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.

Enhanced arsenic removal by in situ formed Fe-Mn binary oxide in the aeration-direct filtration process.

PubMed

Wu, Kun; Liu, Rui-Ping; Liu, Hui-Juan; Lan, Hua-Chun; Qu, Jiu-Hui

2012-11-15

Field studies were conducted to evaluate the feasibility of an in situ formed Fe-Mn binary oxide (in situ FMBO) for improving arsenic (As) removal in the aeration-direct filtration process. The transformation and transportation of As, Fe, and Mn in the filter bed were also investigated. The in situ FMBO increased the As removal efficiency by 20-50% to keep the residual As below 10 μg/L. The optimum FMBO dosage was determined to be 0.55 mg/L with the Fe/Mn ratio as 10:1. The removal of Fe, Mn, turbidity, and particles was also improved to a large extent. The in situ FMBO favored the transformation of soluble As, Fe, and Mn into the solid phases, benefiting the removal of these pollutants by the subsequent filtration. Moreover, the deposited precipitates onto the filter media were characterized, as indicated by the analyses of SEM/EDS and particle size distribution. The long-term experiments exhibited decreased head loss growth and prolonged run length, suggesting an enhanced pollutant catching capacity of the filter media. The full-scale field study with a flow of 10,000 m3/d confirmed positive effects of in situ FMBO on As removal, with the average effluent As concentration reduced from 20 μg/L to 6 μg/L (reagent cost=0.006 ¥/m3). Copyright © 2012 Elsevier B.V. All rights reserved.

Engineering a self-driven PVDF/PDA hybrid membranes based on membrane micro-reactor effect to achieve super-hydrophilicity, excellent antifouling properties and hemocompatibility

NASA Astrophysics Data System (ADS)

Li, Jian-Hua; Ni, Xing-Xing; Zhang, De-Bin; Zheng, Hui; Wang, Jia-Bin; Zhang, Qi-Qing

2018-06-01

A facile and versatile approach for the preparation of super-hydrophilic, excellent antifouling and hemocompatibility membranes had been developed through the generation in situ of bio-inspired polydopamine (PDA) microspheres on PVDF membranes. SEM images showed that the PDA microspheres were uniformly dispersed on the upper surface and the lower surface of the modified membranes. And there were a great number of PDA microspheres immobilized on the cross-section, but the interconnected pores structure was not destroyed. These facts indicated the existence of membrane micro-reactor effect for the whole membrane structure. Considering the remarkable improvement of hydrophilicity, antifouling properties, and permeation fluxes, we also proposed the cluster phenolic hydroxyl effect for the PVDF/PDA hybrid membranes. And the cluster phenolic hydroxyl effect can be ascribed to the all directions distributed phenolic hydroxyl groups on the whole membrane structure. Besides, the self-driven filtration experiments showed the great wetting ability and permeability of the PVDF/PDA hybrid membranes in filtration process without any external pressure. This implied the existence of accelerating self-driven force after the water flow flowed into the internal of membranes, which contributed to the increase of water flow velocity. All the three aspects were in favor of the enhancement of hydrophilicity, antifouling properties and permeability of the modified membranes. Moreover, the conventional filtration tests, oil/water emulsion filtration tests and protein adsorption tests were also carried out to discuss the practical applications of PVDF/PDA hybrid membranes. And the hemocompatibility of the modified membranes was also proved to enhance greatly through the hemolysis tests and platelet adhesion tests, indicating that the membranes were greatly promising in biomedical applications. The strategy of material modification reported here is substrate-independent and can be extended to other substrate materials, and allows the development of novel functional membranes through secondary treatments.

Pressure filtration of ceramic pastes. 4: Treatment of experimental data

NASA Technical Reports Server (NTRS)

Torrecillas, A. S.; Polo, J. F.; Perez, A. A.

1984-01-01

The use of data processing method based on the algorithm proposed by Kalman and its application to the filtration process at constant pressure are described, as well as the advantages of this method. This technique is compared to the least squares method. The operation allows the precise parameter adjustment of the equation in direct relationship to the specific resistance of the cake.

Using the developed cross-flow filtration chip for collecting blood plasma under high flow rate condition and applying the immunoglobulin E detection

NASA Astrophysics Data System (ADS)

Yeh, Chia-Hsien; Hung, Chia-Wei; Wu, Chun-Han; Lin, Yu-Cheng

2014-09-01

This paper presents a cross-flow filtration chip for separating blood cells (white blood cells, red blood cells, and platelets) and obtaining blood plasma from human blood. Our strategy is to flow the sample solution in parallel to the membrane, which can generate a parallel shear stress to remove the clogging microparticles on the membrane, so the pure sample solution is obtained in the reservoir. The cross-flow filtration chip includes a cross-flow layer, a Ni-Pd alloy micro-porous membrane, and a reservoir layer. The three layers are packaged in a polymethylmethacrylate (PMMA) frame to create the cross-flow filtration chip. Various dilutions of the blood sample (original, 2 × , 3 × , 5 × , and 10×), pore sizes with different diameters (1 µm, 2 µm, 4 µm, 7 µm, and 10 µm), and different flow rates (1 mL/min, 3 mL/min, 5 mL/min, 7 mL/min, and 10 mL/min) are tested to determine their effects on filtration percentage. The best filtration percentage is 96.2% when the dilution of the blood sample is 10 × , the diameter of pore size of a Ni-Pd alloy micro-porous membrane is 2 µm, and the flow rate is 10 mL/min. Finally, for the clinical tests of the immunoglobulin E (IgE) concentration, the cross-flow filtration chip is used to filter the blood of the allergy patients to obtain the blood plasma. This filtered blood plasma is compared with that obtained using the conventional centrifugation based on the enzyme-linked immunosorbent assay. The results reveal that these two blood separation methods have similar detection trends. The proposed filtration chip has the advantages of low cost, short filtration time, and easy operation and thus can be applied to the separation of microparticles, cells, bacteria, and blood.

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 the Pythium infection than fungicide application, and nutrient limitation in crops was observed under filtration by activated carbon. Overall, our results suggests that filtration of irrigation water can be effective in reducing crop disease outbreaks, while decreasing the use of fungicides and thus promoting the crop and environmental health.

The Perspective of Riverbank Filtration in China

NASA Astrophysics Data System (ADS)

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

2014-12-01

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

Renal hemodynamics and renin-angiotensin system activity in humans with multifocal renal artery fibromuscular dysplasia.

PubMed

van Twist, Daan J L; Houben, Alphons J H M; de Haan, Michiel W; de Leeuw, Peter W; Kroon, Abraham A

2016-06-01

Fibromuscular dysplasia (FMD) is the second most common cause of renovascular hypertension. Nonetheless, knowledge on the renal microvasculature and renin-angiotensin system (RAS) activity in kidneys with FMD is scarce. Given the fairly good results of revascularization, we hypothesized that the renal microvasculature and RAS are relatively spared in kidneys with FMD. In 58 hypertensive patients with multifocal renal artery FMD (off medication) and 116 matched controls with essential hypertension, we measured renal blood flow (Xenon washout method) per kidney and drew blood samples from the aorta and both renal veins to determine renin secretion and glomerular filtration rate per kidney. We found that renal blood flow and glomerular filtration rate in FMD were comparable to those in controls. Although systemic renin levels were somewhat higher in FMD, renal renin secretion was not elevated. Moreover, in patients with unilateral FMD, no differences between the affected and unaffected kidney were observed with regard to renal blood flow, glomerular filtration rate, or renin secretion. In men, renin levels and renin secretion were higher as compared with women. The renal blood flow response to RAS modulation (by intrarenal infusion of angiotensin II, angiotensin-(1-7), an angiotensin II type 1 receptor blocker, or a nitric oxide synthase blocker) was also comparable between FMD and controls. Renal blood flow, glomerular filtration, and the response to vasoactive substances in kidneys with multifocal FMD are comparable to patients with essential hypertension, suggesting that microvascular function is relatively spared. Renin secretion was not increased and the response to RAS modulation was not affected in kidneys with FMD.

NASA-Enhanced Water Bottles Filter Water on the Go

NASA Technical Reports Server (NTRS)

2014-01-01

Complex systems on the ISS collect and recycle moisture from every possible source-including sweat and urine-to be filtered for recycled use. Greenbrae, California-based ÖKO now sells a water bottle that employs NASA filtration media to purify water as the user squeezes it through the device.

40 CFR 141.571 - What records does subpart T require my system to keep?

Code of Federal Regulations, 2013 CFR

2013-07-01

... (CONTINUED) WATER PROGRAMS (CONTINUED) NATIONAL PRIMARY DRINKING WATER REGULATIONS Enhanced Filtration and... necessary records Duration of time records must be kept (a) Individual Filter Turbidity Requirements(§§ 141.560-141.564) Results of individual filter monitoring At least 3 years. (b) Disinfection Profiling...

40 CFR 141.571 - What records does subpart T require my system to keep?

Code of Federal Regulations, 2011 CFR

2011-07-01

... (CONTINUED) WATER PROGRAMS (CONTINUED) NATIONAL PRIMARY DRINKING WATER REGULATIONS Enhanced Filtration and... necessary records Duration of time records must be kept (a) Individual Filter Turbidity Requirements(§§ 141.560-141.564) Results of individual filter monitoring At least 3 years. (b) Disinfection Profiling...

40 CFR 141.571 - What records does subpart T require my system to keep?

Code of Federal Regulations, 2014 CFR

2014-07-01

... (CONTINUED) WATER PROGRAMS (CONTINUED) NATIONAL PRIMARY DRINKING WATER REGULATIONS Enhanced Filtration and... necessary records Duration of time records must be kept (a) Individual Filter Turbidity Requirements(§§ 141.560-141.564) Results of individual filter monitoring At least 3 years. (b) Disinfection Profiling...

40 CFR 141.571 - What records does subpart T require my system to keep?

Code of Federal Regulations, 2012 CFR

2012-07-01

... (CONTINUED) WATER PROGRAMS (CONTINUED) NATIONAL PRIMARY DRINKING WATER REGULATIONS Enhanced Filtration and... necessary records Duration of time records must be kept (a) Individual Filter Turbidity Requirements(§§ 141.560-141.564) Results of individual filter monitoring At least 3 years. (b) Disinfection Profiling...

40 CFR 141.540 - Who has to develop a disinfection benchmark?

Code of Federal Regulations, 2010 CFR

2010-07-01

...) WATER PROGRAMS (CONTINUED) NATIONAL PRIMARY DRINKING WATER REGULATIONS Enhanced Filtration and Disinfection-Systems Serving Fewer Than 10,000 People Disinfection Benchmark § 141.540 Who has to develop a... 40 Protection of Environment 22 2010-07-01 2010-07-01 false Who has to develop a disinfection...

40 CFR 141.542 - What must my system do if we are considering a significant change to disinfection practices?

Code of Federal Regulations, 2010 CFR

2010-07-01

... considering a significant change to disinfection practices? 141.542 Section 141.542 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) WATER PROGRAMS (CONTINUED) NATIONAL PRIMARY DRINKING WATER REGULATIONS Enhanced Filtration and Disinfection-Systems Serving Fewer Than 10,000 People Disinfection...

40 CFR 141.571 - What records does subpart T require my system to keep?

Code of Federal Regulations, 2010 CFR

2010-07-01

... (CONTINUED) WATER PROGRAMS (CONTINUED) NATIONAL PRIMARY DRINKING WATER REGULATIONS Enhanced Filtration and Disinfection-Systems Serving Fewer Than 10,000 People Reporting and Recordkeeping Requirements § 141.571 What....560-141.564) Results of individual filter monitoring At least 3 years. (b) Disinfection Profiling...

40 CFR 141.510 - Is my system subject to the new finished water reservoir requirements?

Code of Federal Regulations, 2010 CFR

2010-07-01

... finished water reservoir requirements? 141.510 Section 141.510 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) WATER PROGRAMS (CONTINUED) NATIONAL PRIMARY DRINKING WATER REGULATIONS Enhanced Filtration and Disinfection-Systems Serving Fewer Than 10,000 People Finished Water Reservoirs § 141.510 Is...

40 CFR 141.544 - What if my system uses chloramines, ozone, or chlorine dioxide for primary disinfection?

Code of Federal Regulations, 2010 CFR

2010-07-01

..., ozone, or chlorine dioxide for primary disinfection? 141.544 Section 141.544 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) WATER PROGRAMS (CONTINUED) NATIONAL PRIMARY DRINKING WATER REGULATIONS Enhanced Filtration and Disinfection-Systems Serving Fewer Than 10,000 People Disinfection...

40 CFR 141.533 - What data must my system collect to calculate a disinfection profile?

Code of Federal Regulations, 2010 CFR

2010-07-01

... calculate a disinfection profile? 141.533 Section 141.533 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) WATER PROGRAMS (CONTINUED) NATIONAL PRIMARY DRINKING WATER REGULATIONS Enhanced Filtration and Disinfection-Systems Serving Fewer Than 10,000 People Disinfection Profile § 141.533 What data...

40 CFR 141.535 - What if my system uses chloramines, ozone, or chlorine dioxide for primary disinfection?

Code of Federal Regulations, 2010 CFR

2010-07-01

..., ozone, or chlorine dioxide for primary disinfection? 141.535 Section 141.535 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) WATER PROGRAMS (CONTINUED) NATIONAL PRIMARY DRINKING WATER REGULATIONS Enhanced Filtration and Disinfection-Systems Serving Fewer Than 10,000 People Disinfection Profile...

40 CFR 141.570 - What does subpart T require that my system report to the State?

Code of Federal Regulations, 2010 CFR

2010-07-01

... AGENCY (CONTINUED) WATER PROGRAMS (CONTINUED) NATIONAL PRIMARY DRINKING WATER REGULATIONS Enhanced Filtration and Disinfection-Systems Serving Fewer Than 10,000 People Reporting and Recordkeeping Requirements....550-141.553) (1) The total number of filtered water turbidity measurements taken during the month By...

40 CFR 141.521 - What updated watershed control requirements must my unfiltered system implement to continue to...

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 Fewer Than 10,000... oocysts in the source water. Your system's watershed control program must, for Cryptosporidium: (a...

40 CFR 141.521 - What updated watershed control requirements must my unfiltered system implement to continue to...

Code of Federal Regulations, 2012 CFR

2012-07-01

... Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) WATER PROGRAMS (CONTINUED) NATIONAL PRIMARY DRINKING WATER REGULATIONS Enhanced Filtration and Disinfection-Systems Serving Fewer Than 10,000... oocysts in the source water. Your system's watershed control program must, for Cryptosporidium: (a...

40 CFR 141.510 - Is my system subject to the new finished water reservoir requirements?

Code of Federal Regulations, 2011 CFR

2011-07-01

... finished water reservoir requirements? 141.510 Section 141.510 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) WATER PROGRAMS (CONTINUED) NATIONAL PRIMARY DRINKING WATER REGULATIONS Enhanced Filtration and Disinfection-Systems Serving Fewer Than 10,000 People Finished Water Reservoirs § 141.510 Is...

40 CFR 141.521 - What updated watershed control requirements must my unfiltered system implement to continue to...

Code of Federal Regulations, 2014 CFR

2014-07-01

... Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) WATER PROGRAMS (CONTINUED) NATIONAL PRIMARY DRINKING WATER REGULATIONS Enhanced Filtration and Disinfection-Systems Serving Fewer Than 10,000... oocysts in the source water. Your system's watershed control program must, for Cryptosporidium: (a...

40 CFR 141.521 - What updated watershed control requirements must my unfiltered system implement to continue to...

Code of Federal Regulations, 2013 CFR

2013-07-01

... Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) WATER PROGRAMS (CONTINUED) NATIONAL PRIMARY DRINKING WATER REGULATIONS Enhanced Filtration and Disinfection-Systems Serving Fewer Than 10,000... oocysts in the source water. Your system's watershed control program must, for Cryptosporidium: (a...

Enhancement of CNT-based filters efficiency by ion beam irradiation

NASA Astrophysics Data System (ADS)

Elsehly, Emad M.; Chechenin, N. G.; Makunin, A. V.; Shemukhin, A. A.; Motaweh, H. A.

2018-05-01

It is shown in the report that disorder produced by ion beam irradiation can enhance the functionality of the carbon nanotubes. The filters of pressed multiwalled carbon nanotubes (MWNTs) were irradiated by He+ ions of the energy E = 80 keV with the fluence 2 × 1016 ion/cm2. The removal of manganese from aqueous solutions by using pristine and ion beam irradiated MWNTs filters was studied as a function of pH, initial concentration of manganese in aqueous solution, MWNT mass and contact time. The filters before and after filtration were characterized by Raman (RS) and energy dispersive X-ray spectroscopy (EDS) techniques to investigate the deposition content in the filter and defect formation in the MWNTs. The irradiated samples showed an enhancement of removal efficiency of manganese up to 97.5% for 10 ppm Mn concentration, suggesting that irradiated MWNT filter is a better Mn adsorbent from aqueous solutions than the pristine one. Radiation-induced chemical functionalization of MWNTs due to ion beam irradiation, suggesting that complexation between the irradiated MWNTs and manganese ions is another mechanism. This conclusion is supported by EDS and RS and is correlated with a larger disorder in the irradiated samples as follows from RS. The study demonstrates that ion beam irradiation is a promising tool to enhance the filtration efficiency of MWNT filters.

Enhancement of waste activated sludge dewaterability using calcium peroxide pre-oxidation and chemical re-flocculation.

PubMed

Chen, Zhan; Zhang, Weijun; Wang, Dongsheng; Ma, Teng; Bai, Runying; Yu, Dezhong

2016-10-15

The effects of combined calcium peroxide (CaO2) oxidation with chemical re-flocculation on dewatering performance and physicochemical properties of waste activated sludge was investigated in this study. The evolutions of extracellular polymeric substances (EPS) distribution, composition and morphological properties were analyzed to unravel the sludge conditioning mechanism. It was found that sludge filtration performance was enhanced by calcium peroxide oxidation with the optimal dosage of 20 mg/gTSS. However, this enhancement was not observed at lower dosages due to the absence of oxidation and the performance deteriorated at higher dosages because of the release of excess EPS, mainly as protein-like substances. The variation in soluble EPS (SEPS) component can be fitted well with pseudo-zero-order kinetic model under CaO2 treatment. At the same time, extractable EPS content (SEPS and loosely bound EPS (LB-EPS)) were dramatically increased, indicating sludge flocs were effectively broken and their structure became looser after CaO2 addition. The sludge floc structure was reconstructed and sludge dewaterability was significantly enhanced using chemical re-flocculation (polyaluminium chloride (PACl), ferric iron (FeCl3) and polyacrylamide (PAM)). The inorganic coagulants performed better in improving sludge filtration dewatering performance and reducing cake moisture content than organic polymer, since they could act as skeleton builders and decrease the sludge compressibility. Copyright © 2016 Elsevier Ltd. All rights reserved.

Impact of the air filtration on indoor particle concentration by using combination filters in offices building

NASA Astrophysics Data System (ADS)

Kabrein, H.; Hariri, A.; Leman, A. M.; Noraini, N. M. R.; Yusof, M. Z. M.; Afandi, A.

2017-09-01

Heating ventilation and air conditioning system (HVAC) is very important for offices building and human health. The combining filter method was used to reduce the air pollution indoor such as that particulate matter and gases pollution that affected in health and productivity. Using particle filters in industrial HVAC systems (factories and manufacturing process) does not enough to remove all the indoor pollution. The main objective of this study is to investigate the impact of combination filters for particle and gases removal efficiency. The combining method is by using two filters (particulate filter pre-filter and carbon filter) to reduce particle matter and gases respectively. The purpose of this study is to use minimum efficiency reporting value (MERV filter) rating 13 and activated carbon filter (ACF) to remove indoor air pollution and controlling the air change rate to enhance the air quality and energy saving. It was concluded that the combination filter showed good removal efficiency of particle up to 90.76% and 89.25% for PM10 and PM2.5 respectively. The pressure drop across the filters was small compared with the high-efficiency filters. The filtration efficiency of combination filters after three months’ was better than efficiency by the new MERV filter alone.

Application of OMI, SCIAMACHY and GOME-2 Satellite SO2 Retrievals for Detection of Large Emission Sources

NASA Technical Reports Server (NTRS)

Fioletov, V.E.; McLinden, C. A.; Krotkov, N.; Yang, K.; Loyola, D. G.; Valks, P.; Theys, N.; Van Roozendael, M.; Nowlan, C. R.; Chance, K.;

Electro-dewatering of wastewater sludge: An investigation of the relationship between filtrate flow rate and electric current.

PubMed

Olivier, Jérémy; Conrardy, Jean-Baptiste; Mahmoud, Akrama; Vaxelaire, Jean

2015-10-01

Compared to conventional dewatering techniques, electrical assisted mechanical dewatering, also called electro-dewatering (EDW) is an alternative and an effective technology for the dewatering of sewage sludge with low energy consumption. The objectives of this study were to evaluate the dewatering performance and to determine the influence of the process parameters (e.g. applied electric current, applied voltage, and the initial amount of dry solids) on the kinetics of EDW-process for activated urban sludge. Also significant efforts have been devoted herein to provide comprehensive information about the EDW mechanisms and to understand the relationship between these operating conditions with regards to develop a qualitative and quantitative understanding model of the electro-dewatering process and then produce a robust design methodology. The results showed a very strong correlation between the applied electric current and the filtrate flow rate and consequently the electro-dewatering kinetics. A higher applied electric current leads to faster EDW kinetics and a higher final dry solids content. In contrast, the results of this work showed a significant enhancement of the dewatering kinetics by decreasing the mass of the dry solids introduced into the cell (commonly known as the sludge loading). Copyright © 2015 Elsevier Ltd. All rights reserved.

Effects of levosimendan on glomerular filtration rate, renal blood flow, and renal oxygenation after cardiac surgery with cardiopulmonary bypass: a randomized placebo-controlled study.

PubMed

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

2013-10-01

Acute kidney injury develops in a large proportion of patients after cardiac surgery because of the low cardiac output syndrome. The inodilator levosimendan increases cardiac output after cardiac surgery with cardiopulmonary bypass, but a detailed analysis of its effects on renal perfusion, glomerular filtration, and renal oxygenation in this group of patients is lacking. We therefore evaluated the effects of levosimendan on renal blood flow, glomerular filtration rate, renal oxygen consumption, and renal oxygen demand/supply relationship, i.e., renal oxygen extraction, early after cardiac surgery with cardiopulmonary bypass. Prospective, placebo-controlled, and randomized trial. Cardiothoracic ICU of a tertiary center. Postcardiac surgery patients (n=30). The patients were randomized to receive levosimendan, 0.1 µg/kg/min after a loading dose of 12 µg/kg (n=15), or placebo (n=15). The experimental procedure started 4-6 hours after surgery in the ICU during propofol sedation and mechanical ventilation. Systemic hemodynamic were evaluated by a pulmonary artery thermodilution catheter. Renal blood flow and glomerular filtration rate were measured by the renal vein retrograde thermodilution technique and by renal extraction of Cr-EDTA, respectively. Central venous pressure was kept constant by colloid/crystalloid infusion. Compared to placebo, levosimendan increased cardiac index (22%), stroke volume index (15%), and heart rate (7%) and decreased systemic vascular resistance index (21%), whereas mean arterial pressure was not affected. Levosimendan induced significant increases in renal blood flow (12%, p<0.05) and glomerular filtration rate (21%, p<0.05), decreased renal vascular resistance (18%, p<0.05) but caused no significant changes in filtration fraction, renal oxygen consumption, or renal oxygen extraction, compared to placebo. After cardiac surgery with cardiopulmonary bypass, levosimendan induces a vasodilation, preferentially of preglomerular resistance vessels, increasing both renal blood flow and glomerular filtration rate without jeopardizing renal oxygenation. Due to its pharmacodynamic profile, levosimendan might be an interesting alternative for treatment of postoperative heart failure complicated by acute kidney injury in postcardiac surgery patients.

Preclinical evaluation of biodegradable macromolecular contrast agents for magnetic resonance imaging

NASA Astrophysics Data System (ADS)

Feng, Yi

Macromolecular contrast agents have been shown to be superior to small molecular weight contrast agents for MRI in blood pool imaging, tumor diagnosis and grading. However, none has been approved by the FDA because they circulate in the bloodstream much longer than small molecular weight contrast agents and result in high tissue accumulation of toxic Gd(III) ions. Biodegradable macromolecular contrast agents (BMCA) were invented to alleviate the toxic accumulation. They have a cleavable disulfide bond based backbone that can be degraded in vivo and excreted out of the body via renal filtration. Furthermore, the side chain of the backbone can be modified to achieve various degradation rates. Three BMCA, (Gd-DTPA)-cystamine copolymers (GDCC), Gd-DTPA cystine copolymers (GDCP), and Gd-DTPA cystine diethyl ester copolymers (GDCEP), were evaluated as blood pool contrast agents in a rat model. They have excellent blood pool enhancement, preferred pharmacokinetics, and only minimal long-term tissue retention of toxic Gd(III) ions. GDCC and GDCP, the lead agents with desired degradation rates, with molecular weights of 20 KDa and 70 KDa, were chosen for dynamic contrast enhanced MRI (DCE-MRI) to differentiate human prostate tumor models of different malignancy and growth rates. GDCC and GDCP could differentiate these tumor models, providing more accurate estimations of plasma volume, flow leakage rate, and permeability surface area product than a small molecular weight contrast agent Gd-DTPA-BMA when compared to the prototype macromolecular contrast agent albumin-Gd-DTPA. GDCC was favored for its neutral charge side chain and reasonable uptake rate by the tumors. GDCC with a molecular weight of 40 KDa (GDCC-40, above the renal filtration cutoff size) was used to assess the efficacy of two photothermal therapies (interstitial and indocyanine green enhanced). GDCC-40 provided excellent tumor enhancement shortly after its injection. Acute tumor response (4 hr) after therapies was revealed by DCE-MRI using GDCC-40. The region of the tumor with suspicious uptake of GDCC-40 could be correlated to the residual tumor. With only minimum tissue accumulation, BMCA have applications in blood pool imaging, cancer diagnosis, and efficacy assessment of anticancer treatment. Therefore, BMCA are promising for clinical applications.

A Controlled Design of Ripple-Like Polyamide-6 Nanofiber/Nets Membrane for High-Efficiency Air Filter.

PubMed

Zhang, Shichao; Liu, Hui; Zuo, Fenglei; Yin, Xia; Yu, Jianyong; Ding, Bin

2017-03-01

The filtration capacity of fibrous media for airborne particles is restricted by their thick diameter, low porosity, and limited frontal area. The ability to solve this problem would have broad technological implications for various air filtration applications; despite many past efforts, it remains a great challenge to achieve. Herein, a facile and scalable strategy to fabricate the ripple-like polyamide-6 nanofiber/nets (PA-6 NF/N) air filter via combining electrospinning/netting technique with receiving substrate design is demonstrated. This proposed approach allows the scaffold filaments to orderly embed into 2D PA-6 nanonets layer with Steiner-tree structures and nanoscale diameter of ≈20 nm, resulting in the ripple-like membrane with extremely small pore size, highly porous structure, and hugely extended frontal surface, by facilely adjusting its pleat span and pleat pitch. These unique structural advantages enable the ripple-like PA-6 NF/N filter to filtrate the ultrafine particles with high removal efficiency of 99.996%, low air resistance of 95 Pa, and robust quality factor of >0.11 Pa -1 ; using its superlight weight of 0.9 g m -2 and physical sieving manner. This approach has the potentialities to give rise to a novel generation of filter media displaying enhanced filtration capacity for various applications thanks to their nanoscale features and designed macrostructures. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

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

Miyamori, I.; Yasuhara, S.; Takeda, Y.

The effects of captopril on effective renal plasma flow and glomerular filtration rate were studied using a noninvasive radioisotopic method on individual kidneys in eight patients with renovascular hypertension and 12 patients with essential hypertension with various renin levels. Four patients with renovascular hypertension had unilateral while three had bilateral renal artery stenosis. The effective renal plasma flow and glomerular filtration rate were determined by using /sup 131/I-iodohippurate sodium and /sup 99m/Tc-diethylenetriamine pentaacetic acid, respectively. Glomerular filtration rate and effective renal plasma flow were significantly reduced in the stenotic kidneys of patients with renovascular hypertension compared with values in nonstenoticmore » kidneys (p less than 0.01). Treatment with captopril, 37.5 to 75 mg/day for 1 to 48 weeks, further reduced the glomerular filtration rate only in stenotic kidneys, and effective renal plasma flow increased in both kidney types. In two of the three renal hypertensive patients with bilateral renal artery stenosis, captopril produced a reversible azotemia that was unrelated to the fall in blood pressure, as evidenced by the lack of azotemia seen after a moderate blood pressure reduction induced by other antihypertensive medications. These results indicate that endogenous angiotensin II is essential in maintaining the glomerular filtration rate in stenotic kidneys and suggest that a reduction in glomerular filtration rate during captopril administration could indicate the presence of renal artery stenosis.« less

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.

Response of Vitis vinifera cell cultures to Eutypa lata and Trichoderma atroviride culture filtrates: expression of defence-related genes and phenotypes.

PubMed

Mutawila, C; Stander, C; Halleen, F; Vivier, M A; Mostert, L

2017-03-01

Cell suspension cultures of Vitis vinifera cv. Dauphine berries were used to study the response to the vascular pathogen, Eutypa lata, in comparison with a biological control agent, Trichoderma atroviride, that was previously shown to be effective in pruning wound protection. The expression of genes coding for enzymes of the phenylpropanoid pathway and pathogenesis-related (PR) proteins was profiled over a 48-h period using quantitative reverse transcriptase PCR. The cell cultures responded to elicitors of both fungi with a hypersensitive-like response that lead to a decrease in cell viability. Similar genes were triggered by both the pathogen and biocontrol agent, but the timing patterns and magnitude of expression was dependent on the specific fungal elicitor. Culture filtrates of both fungi caused upregulation of phenylalanine ammonia-lyase (PAL), 4-coumaroyl Co-A ligase (CCo-A) and stilbene synthase (STS), and a downregulation of chalcone synthase (CHS) genes. The pathogen filtrate caused a biphasic pattern in the upregulation of PAL and STS genes which was not observed in cells treated with filtrates of the biocontrol agent. Analytical assays showed significantly higher total phenolic content and chitinolytic enzyme activity in the cell cultures treated with the T. atroviride filtrate compared to the pathogen filtrate. These results corresponded well to the higher expression of PAL and chitinase class IV genes. The response of the cell cultures to T. atroviride filtrate provides support for the notion that the wound protection by the biocontrol agent at least partially relies on the induction of grapevine resistance mechanisms.

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.

[Influence of tap water treatment on perfluorinated compounds residue in the dissolved phase].

PubMed

Zhang, Hong; Chen, Qing-wu; Wang, Xin-xuan; Chai, Zhi-fang; Shen, Jin-can; Yang, Bo; Liu, Guo-qing

2013-09-01

To study the perfluorinated compounds (PFCs) residues through water treatments including flocculation, sedimentation, sand filtration, ozonation with activated carbon and chlorination, as well as the seasonal variation of PFCs in the raw water of waterworks, 13 PFCs species in the dissolved phase of raw water, finished water, as well as the water samples after flocculation, sedimentation, sand filtration, and ozonation with activated carbon filtration were measured by the high performance liquid chromatography-tandem mass spectrometry combined with solid phase extraction. Results indicated that sigma PFCs residue in water was higher in spring and summer than that in fall and winter. The vast majority of PFCs in samples were of short and medium chains (C < or = 10), and perfluorooctane sulfonate was the most typical residue species. Among the five water treatment stages, sedimentation, sand filtration and ozonation with activated carbon filtration can remove PFCs, while flocculation and chlorination significantly raise the levels of short- (C < or = 6) and medium-chain (10 > or = C > or = 7) PFCs, respectively, causing sigma PFCs increase in finished water by 10%-44% compared to raw water. However, the PFCs residues in finished water are still far below their limit values, posing no threat against human health.

Single-layer and dual-layer contrast-enhanced mammography using amorphous selenium flat panel detectors

NASA Astrophysics Data System (ADS)

Allec, N.; Abbaszadeh, S.; Karim, K. S.

2011-09-01

The accumulation of injected contrast agents allows the image enhancement of lesions through the use of contrast-enhanced mammography. In this technique, the combination of two acquired images is used to create an enhanced image. There exist several methods to acquire the images to be combined, which include dual energy subtraction using a single detection layer that suffers from motion artifacts due to patient motion between image acquisition. To mitigate motion artifacts, a detector composed of two layers may be used to simultaneously acquire the low and high energy images. In this work, we evaluate both of these methods using amorphous selenium as the detection material to find the system parameters (tube voltage, filtration, photoconductor thickness and relative intensity ratio) leading to the optimal performance. We then compare the performance of the two detectors under the variation of contrast agent concentration, tumor size and dose. The detectability was found to be most comparable at the lower end of the evaluated factors. The single-layer detector not only led to better contrast, due to its greater spectral separation capabilities, but also had lower quantum noise. The single-layer detector was found to have a greater detectability by a factor of 2.4 for a 2.5 mm radius tumor having a contrast agent concentration of 1.5 mg ml-1 in a 4.5 cm thick 50% glandular breast. The inclusion of motion artifacts in the comparison is part of ongoing research efforts.

Single-layer and dual-layer contrast-enhanced mammography using amorphous selenium flat panel detectors.

PubMed

Allec, N; Abbaszadeh, S; Karim, K S

2011-09-21

The accumulation of injected contrast agents allows the image enhancement of lesions through the use of contrast-enhanced mammography. In this technique, the combination of two acquired images is used to create an enhanced image. There exist several methods to acquire the images to be combined, which include dual energy subtraction using a single detection layer that suffers from motion artifacts due to patient motion between image acquisition. To mitigate motion artifacts, a detector composed of two layers may be used to simultaneously acquire the low and high energy images. In this work, we evaluate both of these methods using amorphous selenium as the detection material to find the system parameters (tube voltage, filtration, photoconductor thickness and relative intensity ratio) leading to the optimal performance. We then compare the performance of the two detectors under the variation of contrast agent concentration, tumor size and dose. The detectability was found to be most comparable at the lower end of the evaluated factors. The single-layer detector not only led to better contrast, due to its greater spectral separation capabilities, but also had lower quantum noise. The single-layer detector was found to have a greater detectability by a factor of 2.4 for a 2.5 mm radius tumor having a contrast agent concentration of 1.5 mg ml(-1) in a 4.5 cm thick 50% glandular breast. The inclusion of motion artifacts in the comparison is part of ongoing research efforts.

Preparation of airborne Ag/CNT hybrid nanoparticles using an aerosol process and their application to antimicrobial air filtration.

PubMed

Jung, Jae Hee; Hwang, Gi Byoung; Lee, Jung Eun; Bae, Gwi Nam

2011-08-16

Carbon nanotubes (CNTs) have been widely used in a variety of applications because of their unique structure and excellent mechanical and electrical properties. Additionally, silver (Ag) nanoparticles exhibit broad-spectrum biocidal activity toward many different bacteria, fungi, and viruses. In this study, we prepared Ag-coated CNT hybrid nanoparticles (Ag/CNTs) using aerosol nebulization and thermal evaporation/condensation processes and tested their usefulness for antimicrobial air filtration. Droplets were generated from a CNT suspension using a six-jet collison nebulizer, passed through a diffusion dryer to remove moisture, and entered a thermal tube furnace where silver nanoparticles were generated by thermal evaporation/condensation at ∼980 °C in a nitrogen atmosphere. The CNT and Ag nanoparticle aerosols mixed together and attached to each other, forming Ag/CNTs. For physicochemical characterization, the Ag/CNTs were introduced into a scanning mobility particle sizer (SMPS) for size distribution measurements and were sampled by the nanoparticle sampler for morphological and elemental analyses. For antimicrobial air filtration applications, the airborne Ag/CNT particles generated were deposited continuously onto an air filter medium. Physical characteristics (fiber morphology, pressure drop, and filtration efficiency) and biological characteristics (antimicrobial tests against Staphylococcus epidermidis and Escherichia coli bioaerosols) were evaluated. Real-time SMPS and transmission electron microscopy (TEM) data showed that Ag nanoparticles that were <20 nm in diameter were homogeneously dispersed and adhered strongly to the CNT surfaces. Because of the attachment of Ag nanoparticles onto the CNT surfaces, the total particle surface area concentration measured by a nanoparticle surface area monitor (NSAM) was lower than the summation of each Ag nanoparticle and CNT generated. When Ag/CNTs were deposited on the surface of an air filter medium, the antimicrobial activity against test bacterial bioaerosols was enhanced, compared with the deposition of CNTs or Ag nanoparticles alone, whereas the filter pressure drop and bioaerosol filtration efficiency were similar to those of CNT deposition only. At a residence time of 2 h, the relative microbial viabilities of gram-positive S. epidermidis were ∼32, 13, 5, and 0.9% on the control, CNT-, Ag nanoparticle-, and Ag/CNT-deposited filters, respectively, and those of gram-negative E. coli were 13, 2.1, 0.4, and 0.1% on the control, CNTs, Ag nanoparticles, and Ag/CNTs, respectively. These Ag/CNT hybrid nanoparticles may be useful for applications in biomedical devices and antibacterial control systems.

Two Bioactive Molecular Weight Fractions of a Conditioned Medium Enhance RPE Cell Survival on Age-Related Macular Degeneration and Aged Bruch's Membrane

PubMed Central

Sugino, Ilene K.; Sun, Qian; Springer, Carola; Cheewatrakoolpong, Noounanong; Liu, Tong; Li, Hong; Zarbin, Marco A.

2016-01-01

Purpose To characterize molecular weight fractions of bovine corneal endothelial cell conditioned medium (CM) supporting retinal pigment epithelium (RPE) cell survival on aged and age-related macular degeneration (AMD) Bruch's membrane. Methods CM was subject to size separation using centrifugal filters. Retentate and filtrate fractions were tested for bioactivity by analyzing RPE survival on submacular Bruch's membrane of aged and AMD donor eyes and behavior on collagen I-coated tissue culture wells. Protein and peptide composition of active fractions was determined by mass spectrometry. Results Two bioactive fractions, 3-kDa filtrate and a 10-50–kDa fraction, were necessary for RPE survival on aged and AMD Bruch's membrane. The 3-kDa filtrate, but not the 10-50–kDa fraction, supported RPE growth on collagen 1‐coated tissue culture plates. Mass spectrometry of the 10-50–kDa fraction identified 175 extracellular proteins, including growth factors and extracellular matrix molecules. Transforming growth factor (TGF)β-2 was identified as unique to active CM. Peptides representing 29 unique proteins were identified in the 3-KDa filtrate. Conclusions These results indicate there is a minimum of two bioactive molecules in CM, one found in the 3-kDa filtrate and one in the 10-50–kDa fraction, and that bioactive molecules in both fractions must be present to ensure RPE survival on Bruch's membrane. Mass spectrometry analysis suggested proteins to test in future studies to identify proteins that may contribute to CM bioactivity. Translational Relevance Results of this study are the first steps in development of an adjunct to cell-based therapy to ensure cell transplant survival and functionality in AMD patients. PMID:26933521

Oral cavity hydrodynamics and drag production in Balaenid whale suspension feeding.

PubMed

Potvin, Jean; Werth, Alexander J

2017-01-01

Balaenid whales feed on large aggregates of small and slow-moving prey (predominantly copepods) through a filtration process enabled by baleen. These whales exhibit continuous filtration, namely, with the mouth kept partially opened and the baleen exposed to oncoming prey-laden waters while fluking. The process is an example of crossflow filtration (CFF) in which most of the particulates (prey) are separated from the substrate (water) without ever coming into contact with the filtering surface (baleen). This paper discusses the simulation of baleen filtration hydrodynamics based on a type of hydraulic circuit modeling commonly used in microfluidics, but adapted to the much higher Reynolds number flows typical of whale hydrodynamics. This so-called Baleen Hydraulic Circuit (BHC) model uses as input the basic characteristics of the flows moving through a section of baleen observed in a previous flume study by the authors. The model has low-spatial resolution but incorporates the effects of fluid viscosity, which doubles or more a whale's total body drag in comparison to non-feeding travel. Modeling viscous friction is crucial here since exposing the baleen system to the open ocean ends up tripling a whale's total wetted surface area. Among other findings, the BHC shows how CFF is enhanced by a large filtration surface and hence large body size; how it is carried out via the establishment of rapid anteroposterior flows transporting most of the prey-water slurry towards the oropharyngeal wall; how slower intra-baleen flows manage to transfer most of the substrate out of the mouth, all the while contributing only a fraction to overall oral cavity drag; and how these anteroposterior and intra-baleen flows lose speed as they approach the oropharyngeal wall.

Oral cavity hydrodynamics and drag production in Balaenid whale suspension feeding

PubMed Central

Werth, Alexander J.

2017-01-01

Balaenid whales feed on large aggregates of small and slow-moving prey (predominantly copepods) through a filtration process enabled by baleen. These whales exhibit continuous filtration, namely, with the mouth kept partially opened and the baleen exposed to oncoming prey-laden waters while fluking. The process is an example of crossflow filtration (CFF) in which most of the particulates (prey) are separated from the substrate (water) without ever coming into contact with the filtering surface (baleen). This paper discusses the simulation of baleen filtration hydrodynamics based on a type of hydraulic circuit modeling commonly used in microfluidics, but adapted to the much higher Reynolds number flows typical of whale hydrodynamics. This so-called Baleen Hydraulic Circuit (BHC) model uses as input the basic characteristics of the flows moving through a section of baleen observed in a previous flume study by the authors. The model has low-spatial resolution but incorporates the effects of fluid viscosity, which doubles or more a whale’s total body drag in comparison to non-feeding travel. Modeling viscous friction is crucial here since exposing the baleen system to the open ocean ends up tripling a whale’s total wetted surface area. Among other findings, the BHC shows how CFF is enhanced by a large filtration surface and hence large body size; how it is carried out via the establishment of rapid anteroposterior flows transporting most of the prey-water slurry towards the oropharyngeal wall; how slower intra-baleen flows manage to transfer most of the substrate out of the mouth, all the while contributing only a fraction to overall oral cavity drag; and how these anteroposterior and intra-baleen flows lose speed as they approach the oropharyngeal wall. PMID:28399142

Assessment of Pollutant Removal Efficiency and Drainage Capacity in Stormwater Biofilters

NASA Astrophysics Data System (ADS)

Carroll, S. J.; Mills, H.; Reagan, A.; Triassi, M.; Bauer, S.; Matiasek, S. J.; Libby, R.; Meddings, C.

2016-12-01

Urban stormwater runoff contributes to flooding and impacts water quality with increased sediment and pollutant loads. Biofilters are vegetated filtration systems designed to mitigate stormwater by enhancing infiltration, sedimentation, contaminant sorption and uptake. Despite the rapid implementation of biofilters as stormwater management solutions, their performance is mainly evaluated in terms of flood reduction while their pollutant removal efficiency is rarely assessed. We investigated the effect of biofilter composition on drainage capacity and individual pollutant removal in test columns. Triplicate columns consisted of layers of pebbles, fine sand, filtration mix (test variable), mulch, lava rock and Santa Barbara sedges. The filtration mix was one of five combinations of coarse sand and local loam soil ranging from 100% sand to 100% soil. Consistent with differences in pore size distribution, hydraulic conductivity values were lowest in 100% soil biofilters (3.0 ± 0.6 mm/h) and highest in the 100% sand biofilters (22.7 ± 4.2 mm/h). A synthetic mixture of nutrients, metals, and salts in proportions representative of stormwater composition was applied to the test columns. Biofilters removed over 98% of dissolved copper, nickel, and zinc, and at least 67% of dissolved lead, even when applying synthetic runoff with metal concentrations three orders of magnitude larger than in actual stormwater. In addition, biofilters oxygenated, neutralized, and decreased the turbidity of stormwater. Ammonium was quantitatively removed from synthetic runoff (97-100%), while nitrate and phosphate were poorly retained (48-64%) or even leached from sand biofilters. This study demonstrated that, while decreasing drainage capacity, adding even a small proportion of native soil to the filtration media significantly increases pollutant removal of biofilters. With proper consideration of the filtration mixture, biofiltration systems can effectively remediate urban stormwater.

Aspergillus fumigatus proteases, Asp f 5 and Asp f 13, are essential for airway inflammation and remodelling in a murine inhalation model.

PubMed

Namvar, S; Warn, P; Farnell, E; Bromley, M; Fraczek, M; Bowyer, P; Herrick, S

2015-05-01

In susceptible individuals, exposure to Aspergillus fumigatus can lead to the development of atopic lung diseases such as allergic bronchopulmonary aspergillosis (ABPA) and severe asthma with fungal sensitization (SAFS). Protease allergens including Asp f 5 and Asp f 13 from Aspergillus fumigatus are thought to be important for initiation and progression of allergic asthma. To assess the importance of secreted protease allergens Asp f 5 (matrix metalloprotease) and Asp f 13 (serine protease) in Aspergillus fumigatus-induced inflammation, airway hyperactivity, atopy and airway wall remodelling in a murine model following chronic exposure to secreted allergens. BALB/c mice were repeatedly intranasally dosed over the course of 5 weeks with culture filtrate from wild-type (WT), Asp f 5 null (∆5) or Asp f 13 null (∆13) strains of Aspergillus fumigatus. Airway hyper-reactivity was measured by non-invasive whole-body plethysmography, Th2 response and airway inflammation by ELISA and cell counts, whilst airway remodelling was assessed by histological analysis. Parent WT and ∆5 culture filtrates showed high protease activity, whilst protease activity in ∆13 culture filtrate was low. Chronic intranasal exposure to the three different filtrates led to comparable airway hyper-reactivity and Th2 response. However, protease allergen deleted strains, in particular ∆13 culture filtrate, induced significantly less airway inflammation and remodelling compared to WT culture filtrate. Aspergillus fumigatus-secreted allergen proteases, Asp f 5 and Asp f 13, are important for recruitment of inflammatory cells and remodelling of the airways in this murine model. However, deletion of a single allergen protease fails to alleviate airway hyper-reactivity and allergic immune response. Targeting protease activity of Aspergillus fumigatus in conditions such as SAFS or ABPA may have beneficial effects in preventing key aspects of airway pathology. © 2014 John Wiley & Sons Ltd.

Soft shell clams Mya arenaria with disseminated neoplasia demonstrate reverse transcriptase activity

USGS Publications Warehouse

House, M.L.; Kim, C.H.; Reno, P.W.

1998-01-01

Disseminated neoplasia (DN), a proliferative cell disorder of the circulatory system of bivalves, was first reported in oysters in 1969. Since that time, the disease has been determined to be transmissible through water-borne exposure, but the etiological agent has not been unequivocally identified. In order to determine if a viral agent, possibly a retrovirus, could be the causative agent of DN, transmission experiments were performed, using both a cell-free filtrate and a sucrose gradient-purified preparation of a cell-free filtrate of DN positive materials. Additionally, a PCR-enhanced reverse transcriptase assay was used to determine if reverse transcriptase was present in tissues or hemolymph from DN positive soft shell clams Mya arenaria. DN was transmitted to healthy clams by injection with whole DN cells, but not with cell-free flitrates prepared from either tissues from DN positive clams, or DN cells. The cell-free preparations from DN-positive tissues and hemolymph having high levels of DN cells in circulation exhibited positive reactions in the PCR-enhanced reverse transcriptase assay. Cell-free preparations of hemolymph from clams having low levels of DN (<0.1% of cells abnormal), hemocytes from normal soft shell clams, and normal soft shell clam tissues did not produce a positive reaction in the PCR enhanced reverse transcriptase assay.

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...

40 CFR 141.550 - Is my system required to meet subpart T combined filter effluent turbidity limits?

Code of Federal Regulations, 2011 CFR

2011-07-01

... T combined filter effluent turbidity limits? 141.550 Section 141.550 Protection of Environment... REGULATIONS Enhanced Filtration and Disinfection-Systems Serving Fewer Than 10,000 People Combined Filter Effluent Requirements § 141.550 Is my system required to meet subpart T combined filter effluent turbidity...

40 CFR 141.550 - Is my system required to meet subpart T combined filter effluent turbidity limits?

Code of Federal Regulations, 2014 CFR

2014-07-01

... T combined filter effluent turbidity limits? 141.550 Section 141.550 Protection of Environment... REGULATIONS Enhanced Filtration and Disinfection-Systems Serving Fewer Than 10,000 People Combined Filter Effluent Requirements § 141.550 Is my system required to meet subpart T combined filter effluent turbidity...

40 CFR 141.550 - Is my system required to meet subpart T combined filter effluent turbidity limits?

Code of Federal Regulations, 2013 CFR

2013-07-01

... T combined filter effluent turbidity limits? 141.550 Section 141.550 Protection of Environment... REGULATIONS Enhanced Filtration and Disinfection-Systems Serving Fewer Than 10,000 People Combined Filter Effluent Requirements § 141.550 Is my system required to meet subpart T combined filter effluent turbidity...

40 CFR 141.551 - What strengthened combined filter effluent turbidity limits must my system meet?

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 22 2010-07-01 2010-07-01 false What strengthened combined filter... REGULATIONS Enhanced Filtration and Disinfection-Systems Serving Fewer Than 10,000 People Combined Filter Effluent Requirements § 141.551 What strengthened combined filter effluent turbidity limits must my system...

40 CFR 141.550 - Is my system required to meet subpart T combined filter effluent turbidity limits?

Code of Federal Regulations, 2012 CFR

2012-07-01

... T combined filter effluent turbidity limits? 141.550 Section 141.550 Protection of Environment... REGULATIONS Enhanced Filtration and Disinfection-Systems Serving Fewer Than 10,000 People Combined Filter Effluent Requirements § 141.550 Is my system required to meet subpart T combined filter effluent turbidity...

40 CFR 141.551 - What strengthened combined filter effluent turbidity limits must my system meet?

Code of Federal Regulations, 2013 CFR

2013-07-01

... 40 Protection of Environment 24 2013-07-01 2013-07-01 false What strengthened combined filter... REGULATIONS Enhanced Filtration and Disinfection-Systems Serving Fewer Than 10,000 People Combined Filter Effluent Requirements § 141.551 What strengthened combined filter effluent turbidity limits must my system...

40 CFR 141.551 - What strengthened combined filter effluent turbidity limits must my system meet?

Code of Federal Regulations, 2014 CFR

2014-07-01

... 40 Protection of Environment 23 2014-07-01 2014-07-01 false What strengthened combined filter... REGULATIONS Enhanced Filtration and Disinfection-Systems Serving Fewer Than 10,000 People Combined Filter Effluent Requirements § 141.551 What strengthened combined filter effluent turbidity limits must my system...

40 CFR 141.550 - Is my system required to meet subpart T combined filter effluent turbidity limits?

Code of Federal Regulations, 2010 CFR

2010-07-01

... T combined filter effluent turbidity limits? 141.550 Section 141.550 Protection of Environment... REGULATIONS Enhanced Filtration and Disinfection-Systems Serving Fewer Than 10,000 People Combined Filter Effluent Requirements § 141.550 Is my system required to meet subpart T combined filter effluent turbidity...

40 CFR 141.551 - What strengthened combined filter effluent turbidity limits must my system meet?

Code of Federal Regulations, 2011 CFR

2011-07-01

... 40 Protection of Environment 23 2011-07-01 2011-07-01 false What strengthened combined filter... REGULATIONS Enhanced Filtration and Disinfection-Systems Serving Fewer Than 10,000 People Combined Filter Effluent Requirements § 141.551 What strengthened combined filter effluent turbidity limits must my system...

40 CFR 141.551 - What strengthened combined filter effluent turbidity limits must my system meet?

Code of Federal Regulations, 2012 CFR

2012-07-01

... 40 Protection of Environment 24 2012-07-01 2012-07-01 false What strengthened combined filter... REGULATIONS Enhanced Filtration and Disinfection-Systems Serving Fewer Than 10,000 People Combined Filter Effluent Requirements § 141.551 What strengthened combined filter effluent turbidity limits must my system...

40 CFR 141.501 - Who is subject to the requirements of subpart T?

Code of Federal Regulations, 2010 CFR

2010-07-01

...) WATER PROGRAMS (CONTINUED) NATIONAL PRIMARY DRINKING WATER REGULATIONS Enhanced Filtration and Disinfection-Systems Serving Fewer Than 10,000 People General Requirements § 141.501 Who is subject to the requirements of subpart T? You are subject to these requirements if your system: (a) Is a public water system...

40 CFR 141.534 - How does my system use this data to calculate an inactivation ratio?

Code of Federal Regulations, 2010 CFR

2010-07-01

... AGENCY (CONTINUED) WATER PROGRAMS (CONTINUED) NATIONAL PRIMARY DRINKING WATER REGULATIONS Enhanced Filtration and Disinfection-Systems Serving Fewer Than 10,000 People Disinfection Profile § 141.534 How does... disinfectant application before the first customer The (CTcalc/CT99.9) value of each disinfection segment...

40 CFR 141.531 - What criteria must a State use to determine that a profile is unnecessary?

Code of Federal Regulations, 2010 CFR

2010-07-01

... PROTECTION AGENCY (CONTINUED) WATER PROGRAMS (CONTINUED) NATIONAL PRIMARY DRINKING WATER REGULATIONS Enhanced Filtration and Disinfection-Systems Serving Fewer Than 10,000 People Disinfection Profile § 141.531 What... the month with the warmest water temperature, and at the point of maximum residence time in your...

40 CFR 141.511 - What is required of new finished water reservoirs?

Code of Federal Regulations, 2010 CFR

2010-07-01

...) WATER PROGRAMS (CONTINUED) NATIONAL PRIMARY DRINKING WATER REGULATIONS Enhanced Filtration and Disinfection-Systems Serving Fewer Than 10,000 People Finished Water Reservoirs § 141.511 What is required of... 40 Protection of Environment 22 2010-07-01 2010-07-01 false What is required of new finished water...

40 CFR 141.536 - My system has developed an inactivation ratio; what must we do now?

Code of Federal Regulations, 2010 CFR

2010-07-01

... PROTECTION AGENCY (CONTINUED) WATER PROGRAMS (CONTINUED) NATIONAL PRIMARY DRINKING WATER REGULATIONS Enhanced Filtration and Disinfection-Systems Serving Fewer Than 10,000 People Disinfection Profile § 141.536 My system... in your disinfection profile. Your system will have obtained 52 measurements (one for every week of...

40 CFR 141.530 - What is a disinfection profile and who must develop one?

Code of Federal Regulations, 2010 CFR

2010-07-01

... (CONTINUED) WATER PROGRAMS (CONTINUED) NATIONAL PRIMARY DRINKING WATER REGULATIONS Enhanced Filtration and Disinfection-Systems Serving Fewer Than 10,000 People Disinfection Profile § 141.530 What is a disinfection... 40 Protection of Environment 22 2010-07-01 2010-07-01 false What is a disinfection profile and who...

40 CFR 141.532 - How does my system develop a disinfection profile and when must it begin?

Code of Federal Regulations, 2010 CFR

2010-07-01

... disinfection profile and when must it begin? 141.532 Section 141.532 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) WATER PROGRAMS (CONTINUED) NATIONAL PRIMARY DRINKING WATER REGULATIONS Enhanced Filtration and Disinfection-Systems Serving Fewer Than 10,000 People Disinfection Profile § 141.532 How does...

40 CFR 141.511 - What is required of new finished water reservoirs?

Code of Federal Regulations, 2012 CFR

2012-07-01

...) WATER PROGRAMS (CONTINUED) NATIONAL PRIMARY DRINKING WATER REGULATIONS Enhanced Filtration and Disinfection-Systems Serving Fewer Than 10,000 People Finished Water Reservoirs § 141.511 What is required of... 40 Protection of Environment 24 2012-07-01 2012-07-01 false What is required of new finished water...

40 CFR 141.511 - What is required of new finished water reservoirs?

Code of Federal Regulations, 2011 CFR

2011-07-01

...) WATER PROGRAMS (CONTINUED) NATIONAL PRIMARY DRINKING WATER REGULATIONS Enhanced Filtration and Disinfection-Systems Serving Fewer Than 10,000 People Finished Water Reservoirs § 141.511 What is required of... 40 Protection of Environment 23 2011-07-01 2011-07-01 false What is required of new finished water...

40 CFR 141.531 - What criteria must a State use to determine that a profile is unnecessary?

Code of Federal Regulations, 2014 CFR

2014-07-01

... PROTECTION AGENCY (CONTINUED) WATER PROGRAMS (CONTINUED) NATIONAL PRIMARY DRINKING WATER REGULATIONS Enhanced Filtration and Disinfection-Systems Serving Fewer Than 10,000 People Disinfection Profile § 141.531 What... the month with the warmest water temperature, and at the point of maximum residence time in your...

40 CFR 141.511 - What is required of new finished water reservoirs?

Code of Federal Regulations, 2013 CFR

2013-07-01

...) WATER PROGRAMS (CONTINUED) NATIONAL PRIMARY DRINKING WATER REGULATIONS Enhanced Filtration and Disinfection-Systems Serving Fewer Than 10,000 People Finished Water Reservoirs § 141.511 What is required of... 40 Protection of Environment 24 2013-07-01 2013-07-01 false What is required of new finished water...

40 CFR 141.501 - Who is subject to the requirements of subpart T?

Code of Federal Regulations, 2013 CFR

2013-07-01

...) WATER PROGRAMS (CONTINUED) NATIONAL PRIMARY DRINKING WATER REGULATIONS Enhanced Filtration and Disinfection-Systems Serving Fewer Than 10,000 People General Requirements § 141.501 Who is subject to the requirements of subpart T? You are subject to these requirements if your system: (a) Is a public water system...

40 CFR 141.531 - What criteria must a State use to determine that a profile is unnecessary?

Code of Federal Regulations, 2013 CFR

2013-07-01

... PROTECTION AGENCY (CONTINUED) WATER PROGRAMS (CONTINUED) NATIONAL PRIMARY DRINKING WATER REGULATIONS Enhanced Filtration and Disinfection-Systems Serving Fewer Than 10,000 People Disinfection Profile § 141.531 What... the month with the warmest water temperature, and at the point of maximum residence time in your...

40 CFR 141.531 - What criteria must a State use to determine that a profile is unnecessary?

Code of Federal Regulations, 2011 CFR

2011-07-01

... PROTECTION AGENCY (CONTINUED) WATER PROGRAMS (CONTINUED) NATIONAL PRIMARY DRINKING WATER REGULATIONS Enhanced Filtration and Disinfection-Systems Serving Fewer Than 10,000 People Disinfection Profile § 141.531 What... the month with the warmest water temperature, and at the point of maximum residence time in your...

40 CFR 141.531 - What criteria must a State use to determine that a profile is unnecessary?

Code of Federal Regulations, 2012 CFR

2012-07-01

... PROTECTION AGENCY (CONTINUED) WATER PROGRAMS (CONTINUED) NATIONAL PRIMARY DRINKING WATER REGULATIONS Enhanced Filtration and Disinfection-Systems Serving Fewer Than 10,000 People Disinfection Profile § 141.531 What... the month with the warmest water temperature, and at the point of maximum residence time in your...

40 CFR 141.501 - Who is subject to the requirements of subpart T?

Code of Federal Regulations, 2012 CFR

2012-07-01

...) WATER PROGRAMS (CONTINUED) NATIONAL PRIMARY DRINKING WATER REGULATIONS Enhanced Filtration and Disinfection-Systems Serving Fewer Than 10,000 People General Requirements § 141.501 Who is subject to the requirements of subpart T? You are subject to these requirements if your system: (a) Is a public water system...

40 CFR 141.501 - Who is subject to the requirements of subpart T?

Code of Federal Regulations, 2011 CFR

2011-07-01

...) WATER PROGRAMS (CONTINUED) NATIONAL PRIMARY DRINKING WATER REGULATIONS Enhanced Filtration and Disinfection-Systems Serving Fewer Than 10,000 People General Requirements § 141.501 Who is subject to the requirements of subpart T? You are subject to these requirements if your system: (a) Is a public water system...

40 CFR 141.501 - Who is subject to the requirements of subpart T?

Code of Federal Regulations, 2014 CFR

2014-07-01

...) WATER PROGRAMS (CONTINUED) NATIONAL PRIMARY DRINKING WATER REGULATIONS Enhanced Filtration and Disinfection-Systems Serving Fewer Than 10,000 People General Requirements § 141.501 Who is subject to the requirements of subpart T? You are subject to these requirements if your system: (a) Is a public water system...

40 CFR 141.511 - What is required of new finished water reservoirs?

Code of Federal Regulations, 2014 CFR

2014-07-01

... 40 Protection of Environment 23 2014-07-01 2014-07-01 false What is required of new finished water reservoirs? 141.511 Section 141.511 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) WATER PROGRAMS (CONTINUED) NATIONAL PRIMARY DRINKING WATER REGULATIONS Enhanced Filtration and Disinfection-Systems Serving Fewer Than 10,000...

Effect of interactions between Co(2+) and surface goethite layer on the performance of α-FeOOH coated hollow fiber ceramic ultrafiltration membranes.

PubMed

Zhu, Zhiwen; Zhu, Li; Li, Jianrong; Tang, Jianfeng; Li, Gang; Hsieh, Yi-Kong; Wang, TsingHai; Wang, Chu-Fang

2016-03-15

The consideration of water energy nexus inspires the environmental engineering community to pursue a more sustainable strategy in the wastewater treatment. One potential response would be to enhance the performance of the low-pressure driven filtration system. To reach this objective, it is essential to have a better understanding regarding the surface interaction between the target substance and the surface of membrane. In this study, the hollow fiber ceramic membranes were coated with a goethite layer in order to enhance the Co(2+) rejection. Experimental results indicate that higher Co(2+) rejections are always accompanied with the significant reduction in the permeability. Based on the consideration of electroviscous effect, the surface interactions including the induced changes in viscosity, pore radius and Donnan effect in the goethite layer are likely responsible for the pH dependent behaviors in the rejection and permeability. These results could be valuable references to develop the filtration system with high rejection along with acceptable degree of permeability in the future. Copyright © 2015 Elsevier Inc. All rights reserved.

Discrimination of Nosiheptide Sources with Plasmonic Filters.

PubMed

Wang, Delong; Ni, Haibin; Wang, Zhongqiang; Liu, Bing; Chen, Hongyuan; Gu, Zhongze; Zhao, Xiangwei

2017-04-19

Bacteria identification plays a vital role in the field of clinical diagnosis, food industry, and environmental monitoring, which is in great demand of point of care detection methods. In this paper, in order to discriminate the source of nosiheptide product, a plasmonic filter was fabricated to filtrate, capture and identify Streptomycete spores with Surface enhanced Raman Scattering (SERS). Since the plasmonic filter was derived from self-assembled photonic crystal coated with silver, the plasmonic "hot spots" on the filter surface was distributed evenly in a fare good density and the SERS enhancement factor was 7.49 × 10 7 . With this filter, a stain- and PCR-free detection was realized with only 5 μL sample solution and 5 min in a manner of "filtration and measure". Comparison to traditional Gram stain method and silver-plated nylon filter membrane, the plasmonic filter showed good sensitivity and efficiency in the discrimination of nosiheptide prepared with chemical and biological methods. It is anticipated that this simple SERS detection method with plasmonic filter has promising potentials in food safety, environmental, or clinical applications.

Hydrolytic stability of pneumococcal group 6 (type 6A and 6B) capsular polysaccharides.

PubMed Central

Zon, G; Szu, S C; Egan, W; Robbins, J D; Robbins, J B

1982-01-01

The hydrolyses of the immunologically cross-reactive and constitutionally isomeric group 6 pneumococcal polysaccharides, types 6A and 6B, were investigated by 31P nuclear magnetic resonance spectroscopy, gel filtration through Sepharose 4B, reducing-sugar analysis, and rocket immunoelectrophoresis. Phosphorus nuclear magnetic resonance spectroscopy showed that cleavage of the repeating-unit phosphodiester linkages at pH 10, 60 degrees C was considerably faster (greater than 10(3) ) for the type 6A than the type 6B polysaccharide. Under these reaction conditions, 31P nuclear magnetic resonance kinetic measurements showed that the Na+ form of the type 6A polysaccharide underwent phosphodiester-linkage hydrolysis two times slower than the corresponding Ca+2 form; a stoichiometrically excess amount of Ca+2 caused a 30-fold enhancement of the latter hydrolysis rate. The spectroscopic characterization of phosphorus-containing end groups resulting from hydrolysis of the type 6A polymer provided additional mechanistic information. Heating the type 6A and 6B polysaccharides at 56 degrees C for various times led to gel filtration coefficients of distribution (Kd values) which indicated that the type 6A material underwent size reductions considerably faster than did the type 6B antigen; these increased Kd values qualitatively correlated with the loss of immunochemical reactivity measured by rocket immunoelectrophoresis. The application of a statistical theory to the depolymerization of the type 6A and 6B polysaccharides was consistent with random bond cleavage, as evidenced by the calculated versus measured gel filtration patterns. Although the molecular changes causing the size reductions were not fully elaborated, it was established that the acetal linkages of the type 6A and 6B polysaccharides were comparatively resistant to hydrolysis and that depolymerization by hydrolysis of the phosphodiester linkage was a major factor only in the type 6A structure. It was concluded that the hydrolytic stability of the type 6B antigen would favor its use in the polyvalent pneumococcal vaccine rather than the cross-reactive, but comparatively unstable, type 6A polysaccharide, if all other factors are equal. Images PMID:7107011

Visualization of flow during cleaning process on a liquid nanofibrous filter

NASA Astrophysics Data System (ADS)

Bílek, P.

2017-10-01

This paper deals with visualization of flow during cleaning process on a nanofibrous filter. Cleaning of a filter is very important part of the filtration process which extends lifetime of the filter and improve filtration properties. Cleaning is carried out on flat-sheet filters, where particles are deposited on the filter surface and form a filtration cake. The cleaning process dislodges the deposited filtration cake, which is loose from the membrane surface to the retentate flow. The blocked pores in the filter are opened again and hydrodynamic properties are restored. The presented optical method enables to see flow behaviour in a thin laser sheet on the inlet side of a tested filter during the cleaning process. The local concentration of solid particles is possible to estimate and achieve new information about the cleaning process. In the article is described the cleaning process on nanofibrous membranes for waste water treatment. The hydrodynamic data were compared to the images of the cleaning process.

Next Generation of Electrospun Textiles for Chemical and Biological Protection and Air Filtration

DTIC Science & Technology

2009-09-01

these products were comparable to results reported for reactions of potassium 2,3-butanedione monooximate with GD, which produced 31P resonances at...Next Generation of Electrospun Textiles for Chemical and Biological Protection and Air Filtration by Liang Chen B.S. in Chemical Physics, University... of Science and Technology of China, 2001 M.S. in Chemistry, Brown University, 2004 M.S.C.E.P. in Chemical Engineering, Massachusetts Institute of

Ultrasonic control of ceramic membrane fouling by particles: effect of ultrasonic factors.

PubMed

Chen, Dong; Weavers, Linda K; Walker, Harold W

2006-07-01

Ultrasound at 20 kHz was applied to a cross-flow ultrafiltration system with gamma-alumina membranes in the presence of colloidal silica particles to systematically investigate how ultrasonic factors affect membrane cleaning. Based on imaging of the ultrasonic cavitation region, optimal cleaning occurred when the membrane was outside but close to the cavitation region. Increasing the filtration pressure increased the compressive forces driving cavitation collapse and resulted in fewer cavitation bubbles absorbing and scattering sound waves and increasing sound wave penetration. However, an increased filtration pressure also resulted in greater permeation drag, and subsequently less improvement in permeate flux compared to low filtration pressure. Finally, pulsed ultrasound with short pulse intervals resulted in permeate flux improvement close to that of continuous sonication.

The effects of organic fouling on the removal of radionuclides by reverse osmosis membranes.

PubMed

Ding, Shiyuan; Yang, Yu; Li, Chen; Huang, Haiou; Hou, Li-An

2016-05-15

The removals of cesium (Cs) and strontium (Sr), two hazardous and abundant radionuclides in aquatic environment, were assessed with their isotopes in a synthetic water containing Suwannee River natural organic matter (SRNOM), a natural surface water (SW) and a wastewater effluent (WW) by two different types of ultra-low pressure RO membranes (M1 and M2). The rejections of Sr by the membranes M1 and M2 were higher than 97.5% and 96.0%, respectively, and the rejections of Cs exceeded 90.0% and 85.0%, respectively, in the filtration of real water. The membrane M1 exhibited a more significant flux decline in the filtration of the SRNOM solution, while more severe flux declines were observed with the membrane M2 in the filtration of SW and WW. Protein-like materials with relatively high molecular weight were the main contributors to the flux decline, and humic-acid-like compounds had little effect on the flux decline. Donnan exclusion and size exclusion by humic-acid-like compounds improved the rejections by the membrane M2 with weaker hydrophilicity, while the cake-enhanced concentration polarization reduced the rejections of Cs and Sr by the membrane M1 with stronger hydrophilicity. The ionic strength in the real water resulted in the mitigation of membrane fouling. This study provided important insights into foulant characterization and the mechanisms of organic-fouling-enhanced rejections of Cr and Sr by ultra-low pressure RO membranes. Copyright © 2016 Elsevier Ltd. All rights reserved.

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

PubMed Central

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

2016-01-01

In this study, flat sheet asymmetric polyphenylsulfone (PPSU) ultrafiltration membranes with enhanced antifouling properties were prepared with a non-solvent induced phase separation (NIPS) method through compound additives containing a polymeric pore-forming agent, a small molecular non-solvent and a surfactant. The formation processes of the porous asymmetric membranes with different kinds of additives were studied in detail, and the microstructure controllable preparation of membrane was achieved by establishing a bridge between the membrane preparation parameters and separation performances. All prepared membranes were characterized by using a scanning electron microscope (SEM), contact angle analysis, porosity, maximum pore size, water and BSA solution permeability studies. The performance efficiency of the membrane was evaluated by using BSA as a model foulant in terms of permeability, solute rejection (R), Rm (membrane inherent resistance), Rc (cake layer resistance), and Rp (pore plugging resistance). The results showed that when the compound additives were used, the inter-connected pores were observed, maximum pore size, contact angle and membrane filtration resistance decreased, while the porosity increased. When PVP compound additives were added, the water flux increased from 80.4 to 148.1 L/(m2·h), the BSA rejection increased from 53.2% to 81.5%. A similar trend was observed for membranes with added PEG compound additives; the water flux and BSA rejection simultaneously increased. The filtration resistance decreased as a result of compound additives. The uniformity of membrane and the number of effective pores could be enhanced by adding compound additives through the cooperation of different additives. PMID:27338487

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

PubMed

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

2016-06-21

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

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 decay product concentrations. Copyright © 2011 Elsevier B.V. All rights reserved.

Cardiorespiratory responses of air filtration: A randomized crossover intervention trial in seniors living in Beijing: Beijing Indoor Air Purifier StudY, BIAPSY.

PubMed

Shao, Danqing; Du, Yipeng; Liu, Shuo; Brunekreef, Bert; Meliefste, Kees; Zhao, Qian; Chen, Jie; Song, Xiaoming; Wang, Meng; Wang, Juan; Xu, Hongbing; Wu, Rongshan; Wang, Tong; Feng, Baihuan; Lung, Candice Shih-Chun; Wang, Xian; He, Bei; Huang, Wei

2017-12-15

In this Beijing Indoor Air Purifier StudY (BIAPSY), we conducted a randomized crossover intervention trial in a panel of 35 non-smoking senior participants with free-living, with and without chronic obstructive pulmonary disease (COPD). Portable air filtration units were randomly allocated to active-(filter in) for 2weeks and sham-mode (filter out) for 2weeks in the households. We examined the differences in indoor air pollutant concentrations in 20 study homes and a suite of cardio-respiratory biomarker levels in study participants between filtration modes, with and without adjustment for potential confounders. Following active filtration, we observed significant reductions from 60±45 to 24±15μg/m 3 in ten-day averages of indoor PM 2.5 and reductions from 3.87±1.65 to 1.81±1.19m -1 .10 -5 in ten-day averages of indoor BC, compared to sham-mode filtration. The major components of indoor PM 2.5 , including water soluble organics, NO 3 - , SO 4 2- , Zn 2+ , Pb 2+ and K + , were also reduced significantly by 42% to 63%. However, following active filtration, we only observed significant reductions on systemic inflammation measured as of IL-8 at 58.59% (95% CI: -76.31, -27.64) in the total group of participants and 70.04% (95% CI: -83.05, -47.05) in the subset of COPD patients, with adjustments. We were not able to detect improvements on lung function, blood pressure, and heart rate variability, following short-term intervention of two-week active air filtration. In conclusion, our results showed that indoor air filtration produced clear improvement on indoor air quality, but no demonstrable changes in the cardio-respiratory outcomes of study interest observed in the seniors living with real-world air pollution exposures. Copyright © 2017 Elsevier B.V. All rights reserved.

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 valuable resource pool in our search for natural products with insect immunomodulatory and biocontrol properties. Copyright © 2017 Elsevier Ltd. All rights reserved.

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 in the early phase of acid injury, reduction of fluid filtration contributes to the beneficial effects of partial liquid ventilation on gas exchange and lung mechanics.

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.

Unraveling the catalyzing behaviors of different iron species (Fe2+ vs. Fe0) in activating persulfate-based oxidation process with implications to waste activated sludge dewaterability.

PubMed

Zhen, Guangyin; Lu, Xueqin; Su, Lianghu; Kobayashi, Takuro; Kumar, Gopalakrishnan; Zhou, Tao; Xu, Kaiqin; Li, Yu-You; Zhu, Xuefeng; Zhao, Youcai

2018-05-01

Dewatering of waste activated sludge (WAS) is of major interest in its volume reduction, transportation and ultimate disposal. Persulfate-based oxidation process is a newly developed option for enhancing WAS dewaterability through the generation of powerful sulfate radicals (SO 4 - ·). However, the enhancement in WAS dewaterability by persulfate differs with the species of iron catalysts used. In this study, two types of iron catalysts (i.e. Fe 2+ vs. Fe 0 ) were employed to initiate the persulfate (S 2 O 8 2- ), and the catalyzing behaviors and the underlying principles in enhancing WAS dewaterability were investigated and compared. The Fe 2+ exhibited the high effectiveness in catalyzing the decomposition of persulfate to sulfate radicals (SO 4 - ·), inducing the greater improvement in WAS dewatering. The WAS dewaterability (indicated by dry solids content after filtration) increased with the added S 2 O 8 2- /Fe 2+ dosages, with the dry solids content reaching up to 5.1 ± 0.8 wt% at S 2 O 8 2- /Fe 2+ dosages of 1.2/1.5 mmol/g-VS after only 30 s' filtration, roughly 1.8-fold increase than raw WAS (1.8 ± 0.1 wt%). In contrast, the influence of the persulfate oxidation when activated with Fe 0 on WAS dewaterability was statistically insignificant. The WAS dewaterability remained nearly unchanged (i.e. dry solids content of 2.0 ± 0.0 wt%), irrespective of the employed S 2 O 8 2- /Fe 0 dosages. Further analysis demonstrated that the WAS dewaterability negatively corresponded to loosely bound extracellular polymeric substances (LB-EPS) and tightly bound EPS (TB-EPS). The abundant SO 4 - · from S 2 O 8 2- /Fe 2+ system could effectively disrupt the gel-like EPS matrix, break apart the cells and subsequently arouse the release of the water inside EPS and cells, facilitating water-solid separation. In the case of S 2 O 8 2- /Fe 0 , the dissolution of Fe 0 particles was the rate-limiting step, due to the formation of oxide iron layer near Fe 0 metallic surface, which resulted in the slow SO 4 - · production and thus hardly promoted WAS dewaterability. The pH adjustment could accelerate Fe 0 dissolution and enhance the dewatering performance of S 2 O 8 2- /Fe 0 process to a certain degree, but the effect was unsatisfactory. Additionally, the observations regarding the dissolved organic matters and ammonium collectively revealed that except for enhancing WAS dewatering, S 2 O 8 2- /Fe 2+ oxidation could concurrently degrade COD and ammonia from WAS filtrate, lighten the burden of the subsequent sewage treatment facilities and reduce operational expense. Hence, from an environmental and economic perspective, the S 2 O 8 2- /Fe 2+ system possesses much greater promise for WAS dewatering. Copyright © 2018 Elsevier Ltd. All rights reserved.

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.

Characterization of ultrafiltration of undiluted and diluted stored urine.

PubMed

Ouma, J; Septien, S; Velkushanova, K; Pocock, J; Buckley, C

2016-11-01

Urine ultrafiltration (UF) was studied in terms of flux, permeability, resistance and fouling. Two types of samples were used: stored urine representing the feedstock obtained from urine diversion dry toilets; and diluted stored urine representing the feedstock obtained from urinals. Three different filtration experiment sets were adopted in this study. For the first case, pressure was set in an ascending order, i.e. from 10 to 60 kPa during filtration of stored urine. For the second case, pressure was set in a descending order, i.e. from 60 to 10 kPa for the same feed stream. The third case involved filtration of diluted urine with pressure in ascending order, i.e. from 10 to 60 kPa. The results indicated that diluted urine had higher flux than undiluted urine with maximum values of 43 and 26 L·m -2 ·h -1 respectively. Cake formation was the dominating fouling mechanism during urine filtration with a contribution of about 90% to the total hydraulic resistance. The contribution of chemically irreversible fouling was low (-2%), unless operating from high to low pressures. Indeed, irreversible fouling appeared to be greater during the experiments starting at higher pressure. Although undiluted urine had a higher fouling potential compared to diluted urine, the specific cake resistance was higher for diluted urine, probably due to a denser cake caused by lower particle sizes in that sample. The permeate obtained after urine filtration had much lower suspended solids content compared to the feedstock, with rejections up to 99%. The concentration of the ionic species remained unchanged, and 75% of the organic compounds and dissolved solids remained in the permeate. Urine UF could then be used as pre-treatment to remove suspended solids.

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.

Co-Transplantation of Nanofat Enhances Neovascularization and Fat Graft Survival in Nude Mice.

PubMed

Yu, Qian; Cai, Yizuo; Huang, He; Wang, Zhenxing; Xu, Peng; Wang, Xiangsheng; Zhang, Lu; Zhang, Wenjie; Li, Wei

2018-05-15

Autologous fat grafting is commonly used for soft-tissue augmentation and reconstruction. However, this technique is limited by a high rate of graft absorption. Thus, approaches to improve fat graft survival that promote neovascularization are of great interest. Nanofat has several beneficial features that may render it more suitable for clinical applications than other stem-cell based approaches. We aimed to determine whether nanofat could enhance new vessel formation and improve the long-term retention of fat grafts. Nanofat was processed via mechanical emulsification and filtration. Fat grafts were transplanted subcutaneously under the scalps of nude mice with different nanofat volumes or without nanofat. The grafted fat was dissected 12 weeks after transplantation. Graft weight and volume were measured, and histological evaluations, including capillary density measurement, were performed. The co-transplantation of fat with nanofat showed higher graft weight and volume retention, better histological structure, and higher capillary density compared to that in controls. However, there were no significant differences between the two nanofat volumes utilized. Nanofat can enhance neovascularization and improve fat graft survival, providing a potential clinically viable approach to fat graft supplementation in plastic and reconstructive surgery.

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.

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

PubMed

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

2006-08-25

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

40 CFR 141.542 - What must my system do if we are considering a significant change to disinfection practices?

Code of Federal Regulations, 2013 CFR

2013-07-01

... considering a significant change to disinfection practices? 141.542 Section 141.542 Protection of Environment... REGULATIONS Enhanced Filtration and Disinfection-Systems Serving Fewer Than 10,000 People Disinfection Benchmark § 141.542 What must my system do if we are considering a significant change to disinfection...

40 CFR 141.542 - What must my system do if we are considering a significant change to disinfection practices?

Code of Federal Regulations, 2014 CFR

2014-07-01

... considering a significant change to disinfection practices? 141.542 Section 141.542 Protection of Environment... REGULATIONS Enhanced Filtration and Disinfection-Systems Serving Fewer Than 10,000 People Disinfection Benchmark § 141.542 What must my system do if we are considering a significant change to disinfection...

40 CFR 141.510 - Is my system subject to the new finished water reservoir requirements?

Code of Federal Regulations, 2014 CFR

2014-07-01

... 40 Protection of Environment 23 2014-07-01 2014-07-01 false Is my system subject to the new finished water reservoir requirements? 141.510 Section 141.510 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) WATER PROGRAMS (CONTINUED) NATIONAL PRIMARY DRINKING WATER REGULATIONS Enhanced Filtration and Disinfection-Systems Servin...

Analysis of up-flow aerated biological activated carbon filter technology in drinking water treatment.

PubMed

Lu, Shaoming; Liu, Jincui; Li, Shaowen; Biney, Elizabeth

2013-01-01

Problems have been found in the traditional post-positioned down-flow biological activated carbon filter (DBACF), such as microorganism leakage and low biodegradability. A pilot test was carried out to place a BACF between the sediment tank and the sand filter; a new technology of dual media up-flow aerated biological activated carbon filter (UBACF) was developed. Results showed that in terms of the new process, the up-flow mode was better than the down-flow. Compared with the DBACF, the problem of microorganism leakage could be well resolved with the UBACF process by adding disinfectant before the sand filtration, and a similar adsorption effect could be obtained. For the tested raw water, the COD(Mn) and NH3-N removal rate was 54.6% and 85.0%, respectively, similar to the waterworks with the DBACF process. The UBACF greatly enhanced oxygen supply capability and mass transfer rate via aeration, and the NH3-N removal ability was significantly improved from 1.5 mg/L to more than 3 mg/L. Influent to the UBACF with higher turbidity could be coped with through the primary filtration of the ceramisite layer combined with fluid-bed technology, which gave the carbon bed a low-turbidity environment of less than 1.0 NTU. The backwashing parameters and carbon abrasion rate of the two processes were almost the same.

Forward osmosis filtration for removal of organic foulants: Effects of combined tannic and alginic acids.

PubMed

Wang, Lin; Zhang, Wanzhu; Chu, Huaqiang; Dong, Bingzhi

2016-03-15

The filtration performance of combined organic foulants by forward osmosis (FO) in active-layer-facing-the-draw-solution (AL-facing-DS) orientation was investigated systematically. Tannic acid and alginate were used as model organic foulants for polysaccharides and humic dissolved organic matters, respectively. The FO could reject combined and single tannic acid and alginate foulants effectively. The more severe fouling flux decline, accompanied with lower combined foulants' retention, was observed with increasing proportions of tannic acid in the combined foulants-containing feed, which was ascribed mainly to the more severe fouling resulting from tannic acid adsorption within the porous support layer of the FO membrane compared to minor alginate deposition on the membrane surface. It was found that the higher the initial flux level and cross flow velocity, the faster the flux decline with lower mixed foulants retention. It was also revealed that the calcium ions in a basic solution enhanced the combined fouling flux reduction and combined foulants retention. As the major constituent of the combined fouling layer, the adsorption of tannic acid might play a more significant role in the mixed fouling of the FO membrane, which was probably influenced by permeation drag caused by water flux and chemical interactions induced by feed solution pH and calcium ion concentration. Copyright © 2016 Elsevier Ltd. All rights reserved.

Membrane fouling and performance evaluation of conventional membrane bioreactor (MBR), moving biofilm MBR and oxic/anoxic MBR.

PubMed

Khan, Sher Jamal; Ahmad, Aman; Nawaz, Muhammad Saqib; Hankins, Nicholas P

2014-01-01

In this study, three laboratory scale submerged membrane bioreactors (MBRs) comprising a conventional MBR (C-MBR), moving bed MBR (MB-MBR) and anoxic-oxic MBR (A/O-MBR) were continuously operated with synthesized domestic wastewater (chemical oxygen demand, COD = 500 mg/L) for 150 days under similar operational and environmental conditions. Kaldnes(®) plastic media with 20% dry volume was used as a biofilm carrier in the MB-MBR and A/O-MBR. The treatment performance and fouling propensity of the MBRs were evaluated. The effect of cake layer formation in all three MBRs was almost the same. However, pore blocking caused a major difference in the resultant water flux. The A/O-MBR showed the highest total nitrogen and phosphorus (PO4-P) removal efficiencies of 83.2 and 69.7%, respectively. Due to the high removal of nitrogen, fewer protein contents were found in the soluble and bound extracellular polymeric substances (EPS) of the A/O-MBR. Fouling trends of the MBRs showed 12, 14 and 20 days filtration cycles for C-MBR, MB-MBR and A/O-MBR, respectively. A 25% reduction of the soluble EPS and a 37% reduction of the bound EPS concentrations in A/O-MBR compared with C-MBR was a major contributing factor for fouling retardation and the enhanced filtration capacity of the A/O-MBR.

Recovery of a marker strain of Escherichia coli from ozonated water by membrane filtration

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

Finch, G.R.; Stiles, M.E.; Smith, D.W.

1987-12-01

Selective and nonselective growth media were evaluated at two incubation temperatures, 35 and 44.5 degrees C, for the recovery of a nalidixic acid-resistant marker strain of Escherichia coli ATCC 11775 by membrane filtration from ozonated 0.05 M phosphate buffer (pH 6.9). There were significantly fewer bacteria recovered with the standard m-FC agar when compared with the same growth medium prepared without bile salts and rosolic acid. This effect was particularly noticeable at the elevated incubation temperature of 44.5 degrees C. These findings are contrary to previous work which concluded that the standard American Public Health Association membrane filtration procedure ismore » suitable for recovery of fecal coliform indicator bacteria from ozonated wastewater.« less

Cellulose nanoparticles as modifiers for rheology and fluid loss in bentonite water-based fluids.

PubMed

Li, Mei-Chun; Wu, Qinglin; Song, Kunlin; Qing, Yan; Wu, Yiqiang

2015-03-04

Rheological and filtration characteristics of drilling fluids are considered as two critical aspects to ensure the success of a drilling operation. This research demonstrates the effectiveness of cellulose nanoparticles (CNPs), including microfibrillated cellulose (MFC) and cellulose nanocrystals (CNCs) in enhancing the rheological and filtration performances of bentonite (BT) water-based drilling fluids (WDFs). CNCs were isolated from MFC through sulfuric acid hydrolysis. In comparison with MFC, the resultant CNCs had much smaller dimensions, more negative surface charge, higher stability in aqueous solutions, lower viscosity, and less evident shear thinning behavior. These differences resulted in the distinctive microstructures between MFC/BT- and CNC/BT-WDFs. A typical "core-shell" structure was created in CNC/BT-WDFs due to the strong surface interactions among BT layers, CNCs, and immobilized water molecules. However, a similar structure was not formed in MFC/BT-WDFs. As a result, CNC/BT-WDFs had superior rheological properties, higher temperature stability, less fluid loss volume, and thinner filter cakes than BT and MFC/BT-WDFs. Moreover, the presence of polyanionic cellulose (PAC) further improved the rheological and filtration performances of CNC/BT-WDFs, suggesting a synergistic effect between PAC and CNCs.

Enhanced diffusion on oscillating surfaces through synchronization

NASA Astrophysics Data System (ADS)

Wang, Jin; Cao, Wei; Ma, Ming; Zheng, Quanshui

2018-02-01

The diffusion of molecules and clusters under nanoscale confinement or absorbed on surfaces is the key controlling factor in dynamical processes such as transport, chemical reaction, or filtration. Enhancing diffusion could benefit these processes by increasing their transport efficiency. Using a nonlinear Langevin equation with an extensive number of simulations, we find a large enhancement in diffusion through surface oscillation. For helium confined in a narrow carbon nanotube, the diffusion enhancement is estimated to be over three orders of magnitude. A synchronization mechanism between the kinetics of the particles and the oscillating surface is revealed. Interestingly, a highly nonlinear negative correlation between diffusion coefficient and temperature is predicted based on this mechanism, and further validated by simulations. Our results provide a general and efficient method for enhancing diffusion, especially at low temperatures.

Endohyphal Bacterium Enhances Production of Indole-3-Acetic Acid by a Foliar Fungal Endophyte

PubMed Central

Hoffman, Michele T.; Gunatilaka, Malkanthi K.; Wijeratne, Kithsiri; Gunatilaka, Leslie; Arnold, A. Elizabeth

2013-01-01

Numerous plant pathogens, rhizosphere symbionts, and endophytic bacteria and yeasts produce the important phytohormone indole-3-acetic acid (IAA), often with profound effects on host plants. However, to date IAA production has not been documented among foliar endophytes -- the diverse guild of primarily filamentous Ascomycota that live within healthy, above-ground tissues of all plant species studied thus far. Recently bacteria that live within hyphae of endophytes (endohyphal bacteria) have been detected, but their effects have not been studied previously. Here we show not only that IAA is produced in vitro by a foliar endophyte (here identified as Pestalotiopsis aff. neglecta, Xylariales), but that IAA production is enhanced significantly when the endophyte hosts an endohyphal bacterium (here identified as Luteibacter sp., Xanthomonadales). Both the endophyte and the endophyte/bacterium complex appear to rely on an L-tryptophan dependent pathway for IAA synthesis. The bacterium can be isolated from the fungus when the symbiotic complex is cultivated at 36°C. In pure culture the bacterium does not produce IAA. Culture filtrate from the endophyte-bacterium complex significantly enhances growth of tomato in vitro relative to controls and to filtrate from the endophyte alone. Together these results speak to a facultative symbiosis between an endophyte and endohyphal bacterium that strongly influences IAA production, providing a new framework in which to explore endophyte-plant interactions. PMID:24086270

Effect of elicitors and precursors on azadirachtin production in hairy root culture of Azadirachta indica.

PubMed

Srivastava, Smita; Srivastava, A K

2014-02-01

The present study involved strategies for enhancement in in vitro azadirachtin (commercially used biopesticide) production by hairy root cultivation of Azadirachta indica. Improvement in the azadirachtin production via triggering its biosynthetic pathway in plant cells was carried out by the exogenous addition of precursors and elicitors in the growth medium. Among the different abiotic stress inducers (Ag(+), Hg(+2), Co(+2), Cu(+2)) and signal molecules (methyl jasmonate and salicylic acid) tested, salicylic acid at 15 mg l(-1) of concentration was found to enhance the azadirachtin yield in the hairy roots to the maximum (up to 4.95 mg g(-1)). Similarly, among the different biotic elicitors tested (filter-sterilized fungal culture filtrates of Phoma herbarium, Alternaria alternata, Myrothecium sp., Fusarium solani, Curvularia lunata, and Sclerotium rolfsii; yeast extract; and yeast extract carbohydrate fraction), addition of filter-sterilized fungal culture filtrate of C. lunata (1 % v/v) resulted in maximum azadirachtin yield enhancement in hairy root biomass (up to 7.1 mg g(-1)) with respect to the control (3.3 mg g(-1)). Among all the biosynthetic precursors studied (sodium acetate, cholesterol, squalene, isopentynyl pyrophosphate, mavalonic acid lactone, and geranyl pyrophosphate), the overall azadirachtin production (70.42 mg l(-1) in 25 days) was found to be the highest with cholesterol (50 mg l(-1)) addition as an indirect precursor in the medium.

Dynamic alteration in splenic function during acute falciparum malaria

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

Looareesuwan, S.; Ho, M.; Wattanagoon, Y.

Plasmodium-infected erythrocytes lose their normal deformability and become susceptible to splenic filtration. In animal models, this is one mechanism of antimalarial defense. To assess the effect of acute falciparum malaria on splenic filtration, we measured the clearance of heated /sup 51/Cr-labeled autologous erythrocytes in 25 patients with acute falciparum malaria and in 10 uninfected controls. Two groups of patients could be distinguished. Sixteen patients had splenomegaly, markedly accelerated clearance of the labeled erythrocytes (clearance half-time, 8.4 +/- 4.4 minutes (mean +/- SD) vs. 62.5 +/- 36.5 minutes in controls; P less than 0.001), and a lower mean hematocrit than didmore » the patients without splenomegaly (P less than 0.001). In the nine patients without splenomegaly, clearance was normal. After institution of antimalarial chemotherapy, however, the clearance in this group accelerated to supernormal rates similar to those in the patients with splenomegaly, but without the development of detectable splenomegaly. Clearance was not significantly altered by treatment in the group with splenomegaly. Six weeks later, normal clearance rates were reestablished in most patients in both groups. We conclude that splenic clearance of labeled erythrocytes is enhanced in patients with malaria if splenomegaly is present and is enhanced only after treatment if splenomegaly is absent. Whether this enhanced splenic function applies to parasite-infected erythrocytes in patients with malaria and has any clinical benefit will require further studies.« less

Involvement of Renal Corpuscle microRNA Expression on Epithelial-to-Mesenchymal Transition in Maternal Low Protein Diet in Adult Programmed Rats

PubMed Central

Sene, Letícia de Barros; Mesquita, Flávia Fernandes; de Moraes, Leonardo Nazário; Santos, Daniela Carvalho; Carvalho, Robson; Gontijo, José Antônio Rocha; Boer, Patrícia Aline

2013-01-01

Prior study shows that maternal protein-restricted (LP) 16-wk-old offspring have pronounced reduction of nephron number and arterial hypertension associated with unchanged glomerular filtration rate, besides enhanced glomerular area, which may be related to glomerular hyperfiltration/overflow and which accounts for the glomerular filtration barrier breakdown and early glomerulosclerosis. In the current study, LP rats showed heavy proteinuria associated with podocyte simplification and foot process effacement. TGF-β1 glomerular expression was significantly enhanced in LP. Isolated LP glomeruli show a reduced level of miR-200a, miR-141, miR-429 and ZEB2 mRNA and upregulated collagen 1α1/2 mRNA expression. By western blot analyzes of whole kidney tissue, we found significant reduction of both podocin and nephrin and enhanced expression of mesenchymal protein markers such as desmin, collagen type I and fibronectin. From our present knowledge, these are the first data showing renal miRNA modulation in the protein restriction model of fetal programming. The fetal-programmed adult offspring showed pronounced structural glomerular disorders with an accentuated and advanced stage of fibrosis, which led us to state that the glomerular miR-200 family would be downregulated by TGF-β1 action inducing ZEB 2 expression that may subsequently cause glomeruli epithelial-to-mesenchymal transition. PMID:23977013

Optimization of the cleaning process on a pilot filtration setup for waste water treatment accompanied by flow visualization

NASA Astrophysics Data System (ADS)

Bílek, Petr; Hrůza, Jakub

2018-06-01

This paper deals with an optimization of the cleaning process on a liquid flat-sheet filter accompanied by visualization of the inlet side of a filter. The cleaning process has a crucial impact on the hydrodynamic properties of flat-sheet filters. Cleaning methods avoid depositing of particles on the filter surface and forming a filtration cake. Visualization significantly helps to optimize the cleaning methods, because it brings new overall view on the filtration process in time. The optical method, described in the article, enables to see flow behaviour in a thin laser sheet on the inlet side of a tested filter during the cleaning process. Visualization is a strong tool for investigation of the processes on filters in details and it is also possible to determine concentration of particles after an image analysis. The impact of air flow rate, inverse pressure drop and duration on the cleaning mechanism is investigated in the article. Images of the cleaning process are compared to the hydrodynamic data. The tests are carried out on a pilot filtration setup for waste water treatment.

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.

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.

Improved HCP Reduction Using a New, All-Synthetic Depth Filtration Media Within an Antibody Purification Process.

PubMed

Nguyen, Hoang C; Langland, Amie L; Amara, John P; Dullen, Michael; Kahn, David S; Costanzo, Joseph A

2018-04-30

Biologic manufacturing processes typically employ clarification technologies like depth filtration to remove insoluble and soluble impurities. Conventional depth filtration media used in these processes contain naturally-derived components like diatomaceous earth and cellulose. These components may introduce performance variability and contribute extractable/leachable components like beta-glucans that could interfere with limulus amebocyte lysate endotoxin assays. Recently a novel, all-synthetic depth filtration media is developed (Millistak+ ® HC Pro X0SP) that may improve process consistency, efficiency, and drug substance product quality by reducing soluble process impurities. This new media is evaluated against commercially available benchmark filters containing naturally-derived components (Millistak+ ® HC X0HC and B1HC). Using model proteins, the synthetic media demonstrates increased binding capacity of positively charged proteins (72-126 mg g -1 media) compared to conventional media (0.3-8.6 mg g -1 media); and similar values for negatively charged species (1.3-5.6 mg g -1 media). Several CHO-derived monoclonal antibodies (mAbs) or mAb-like molecules are also evaluated. The X0SP filtration performance behaves similarly to benchmarks, and exhibits improved HCP reduction (at least 50% in 55% of cases tested). X0SP filtrates contained increased silicon extractables relative to benchmarks, but these were readily removed downstream. Finally, the X0SP devices demonstrates suitable lot-to-lot robustness when specific media components are altered intentionally to manufacturing specification limits. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Ex Vivo Application of Secreted Metabolites Produced by Soil-Inhabiting Bacillus spp. Efficiently Controls Foliar Diseases Caused by Alternaria spp.

PubMed Central

El-Sayed, Ashraf S. A.; Patel, Jaimin S.; Green, Kari B.; Ali, Mohammad; Brennan, Mary; Norman, David

2015-01-01

Bacterial biological control agents (BCAs) are largely used as live products to control plant pathogens. However, due to variable environmental and ecological factors, live BCAs usually fail to produce desirable results against foliar pathogens. In this study, we investigated the potential of cell-free culture filtrates of 12 different bacterial BCAs isolated from flower beds for controlling foliar diseases caused by Alternaria spp. In vitro studies showed that culture filtrates from two isolates belonging to Bacillus subtilis and Bacillus amyloliquefaciens displayed strong efficacy and potencies against Alternaria spp. The antimicrobial activity of the culture filtrate of these two biological control agents was effective over a wider range of pH (3.0 to 9.0) and was not affected by autoclaving or proteolysis. Comparative liquid chromatography-mass spectrometry (LC-MS) analyses showed that a complex mixture of cyclic lipopeptides, primarily of the fengycin A and fengycin B families, was significantly higher in these two BCAs than inactive Bacillus spp. Interaction studies with mixtures of culture filtrates of these two species revealed additive activity, suggesting that they produce similar products, which was confirmed by LC-tandem MS analyses. In in planta pre- and postinoculation trials, foliar application of culture filtrates of B. subtilis reduced lesion sizes and lesion frequencies caused by Alternaria alternata by 68 to 81%. Taken together, our studies suggest that instead of live bacteria, culture filtrates of B. subtilis and B. amyloliquefaciens can be applied either individually or in combination for controlling foliar diseases caused by Alternaria species. PMID:26519395

Burdock fructooligosaccharide enhances biocontrol of Rhodotorula mucilaginosa to postharvest decay of peaches.

PubMed

Zhang, Hongyin; Liu, Zhouyang; Xu, Baitian; Chen, Keping; Yang, Qiya; Zhang, Qiuyun

2013-10-15

The influence of adding burdock fructooligosaccharide (BFO) in the culture media on the efficacy of Rhodotorula mucilaginosa in controlling postharvest decay of peaches and its possible mode of action were investigated. The antagonistic activity of R. mucilaginosa to Rhizopus decay and blue mold decay of peaches was greatly enhanced through cultivation in the nutrient yeast dextrose agar (NYDA) medium amended with BFO at the concentration of 0.32%, compared with that cultivated in NYDB without BFO. R. mucilaginosa at 1×10(8) cells/mL cultivation in the NYDB media did not reduce the natural decay incidence of peaches, compared with the control after 30 d at 4 °C followed by 7d at 20 °C. However, R. mucilaginosa cultivation in the NYDB media amended with BFO at the concentration of 0.32% reduced the natural decay incidence of peaches. The population of R. mucilaginosa harvested from NYDB amended with BFO at 0.32% increased rapidly in peach wounds compared to that harvested from NYDB without BFO no matter peaches were stored at 20 °C or 4 °C. The activities of chitinase and β-1,3-glucanase of cell-free culture filtrate of R. mucilaginosa harvested from NYDB amended with BFO at 0.32% were higher than that at other concentrations and the control. Copyright © 2013 Elsevier Ltd. All rights reserved.

Diagnostic value of quantitative contrast-enhanced ultrasound (CEUS) for early detection of renal hyperperfusion in diabetic kidney disease.

PubMed

Wang, Ling; Wu, Jian; Cheng, Jia-Fen; Liu, Xin-Ying; Ma, Fang; Guo, Le-Hang; Xu, Jun-Mei; Wu, Tianfu; Mohan, Chandra; Peng, Ai; Xu, Hui-Xiong; Song, Ya-Xiang

2015-12-01

To investigate the diagnostic value of quantitative contrast-enhanced ultrasound (CEUS) for early detection of renal hyperperfusion in diabetic kidney disease (DKD). 55 DKD patients with estimated glomerular filtration rate (eGFR) >30 ml/min/1.73 m(2) and 26 normal controls (NCs) were enrolled. Clinical data was well documented. Blood samples were drawn for evaluation of renal function including blood urea nitrogen (BUN), serum creatinine (SCr) and serum uric acid (SUA), and urine samples were assayed for total protein quantification, and various microprotein markers. According to eGFR level, DKD patients were divided into early-stage DKD (eGFR ≥90 ml/min/1.73 m(2), n = 18) and middle-stage DKD (eGFR 30-90 ml/min/1.73 m(2), n = 37). Based on urinary microalbumin/creatinine ratio (MALB/UCR), early-stage DKD patients were further classified into two groups: MALB/UCR <10 g/mol (n = 11) and MALB/UCR ≥10 g/mol (n = 7). Then, CEUS was performed to observe the real-time renal perfusion, and low acoustic power contrast-specific imaging was used for quantitative analysis. The renal perfusion images of CEUS were well developed successively. The corresponding perfusion curves based on echo-power signals in time series were constructed. Quantitative analysis showed that area under the descending curve (AUC2) was significantly increased in early-stage DKD compared to middle-stage DKD (p < 0.05), but AUC showed no significant difference. Further comparison between different MALB/UCR levels of early-stage DKD showed that patients with MALB/UCR ≥10 g/mol had significantly increased levels of AUC, AUC2 and proteinuria than patients with low MALB/UCR (p < 0.05). Also, high MALB/UCR DKD patients had increased proteinuria but similar eGFR compared to low MALB/UCR patients. Renal microvascular hyperperfusion may be responsible for overt proteinuria until decline of renal filtration in DKD. AUC2 could be an early and sensitive marker for early renal injury and renal microvascular hyperperfusion in DKD.

Hybrid Filter Membrane

NASA Technical Reports Server (NTRS)

Laicer, Castro; Rasimick, Brian; Green, Zachary

2012-01-01

Cabin environmental control is an important issue for a successful Moon mission. Due to the unique environment of the Moon, lunar dust control is one of the main problems that significantly diminishes the air quality inside spacecraft cabins. Therefore, this innovation was motivated by NASA s need to minimize the negative health impact that air-suspended lunar dust particles have on astronauts in spacecraft cabins. It is based on fabrication of a hybrid filter comprising nanofiber nonwoven layers coated on porous polymer membranes with uniform cylindrical pores. This design results in a high-efficiency gas particulate filter with low pressure drop and the ability to be easily regenerated to restore filtration performance. A hybrid filter was developed consisting of a porous membrane with uniform, micron-sized, cylindrical pore channels coated with a thin nanofiber layer. Compared to conventional filter media such as a high-efficiency particulate air (HEPA) filter, this filter is designed to provide high particle efficiency, low pressure drop, and the ability to be regenerated. These membranes have well-defined micron-sized pores and can be used independently as air filters with discreet particle size cut-off, or coated with nanofiber layers for filtration of ultrafine nanoscale particles. The filter consists of a thin design intended to facilitate filter regeneration by localized air pulsing. The two main features of this invention are the concept of combining a micro-engineered straight-pore membrane with nanofibers. The micro-engineered straight pore membrane can be prepared with extremely high precision. Because the resulting membrane pores are straight and not tortuous like those found in conventional filters, the pressure drop across the filter is significantly reduced. The nanofiber layer is applied as a very thin coating to enhance filtration efficiency for fine nanoscale particles. Additionally, the thin nanofiber coating is designed to promote capture of dust particles on the filter surface and to facilitate dust removal with pulse or back airflow.

Blend-electrospun graphene oxide/Poly(vinylidene fluoride) nanofibrous membranes with high flux, tetracycline removal and anti-fouling properties.

PubMed

Park, Jeong-Ann; Nam, Aram; Kim, Jae-Hyun; Yun, Seong-Taek; Choi, Jae-Woo; Lee, Sang-Hyup

2018-09-01

Graphene oxide (GO)/poly(vinylidene fluoride) (PVDF) electrospun nanofibrous membranes (ENMs) have been fabricated to remove tetracycline (TC) from water via adsorptive-filtration. The pure water permeation flux of GO/PVDF ENMs (27,407-29,337 LMH/bar) was increased compared with that of PVDF ENMs. The flow pore diameter was steadily reduced by increasing the GO content from 0 to 1.5 wt% in the GO/PVDF ENMs. The maximum TC adsorption capacity of GO is 720.26 mg/g (Langmuir model) and GO retained its TC adsorption property after incorporation into GO/PVDF ENMs during water filtration (transmembrane pressure = 0.91 bar). The maximum experimental TC removal capacity (q a , exp ) was 17.92 mg/g with 1.5 wt% of GO (GO 1.5 /PVDF) ENMs, which was similar to the modified dose-response model value of 18.03 mg/g. In the presence of natural organic matter, TC adsorption was enhanced, because hydrophobic organic carbon improved hydrophobic and π-π interactions. The presence of Cu(II) further improved the TC adsorption capacity of GO 1.5 /PVDF ENMs through cation bridging. However, the presence of Ca(II) hindered TC adsorption by an electron shielding effect. For examining anti-fouling activity of GO 1.5 /PVDF ENMs, the log removal values of both bacteria, Escherichia coli and Staphylococcus aureus, were maintained at over 5 during water filtration. In addition, incorporation of GO in PVDF ENMs prevents bovine serum albumin (BSA) adsorption by both increasing the hydrophilicity of the ENMs forming hydration layer on the surface and electrostatic repulsion between both negatively charged BSA and GO in GO 1.5 /PVDF ENMs (zeta potential = - 14.14 mV, deionized water at pH 6). Copyright © 2018 Elsevier Ltd. All rights reserved.

Optimization of an enhanced ceramic micro-filter for concentrating E.coli in water

NASA Astrophysics Data System (ADS)

Zhang, Yushan; Guo, Tianyi; Xu, Changqing; Hong, Lingcheng

2017-02-01

Recently lower limit of detection (LOD) is necessary for rapid bacteria detection and analysis applications in clinical practices and daily life. A critical pre-conditioning step for these applications is bacterial concentration, especially for low level of pathogens. Sample volume can be largely reduced with an efficient pre-concentration process. Some approaches such as hollow-fiber ultra-filtration and electrokinetic technique have been applied to bacterial concentration. Since none of these methods can provide a concentrating method with a stable recovery efficiency, bacterial concentration still remains challenging Ceramic micro- filter can be used to concentrate the bacteria but the cross flow system keeps the bacteria in suspension. Similar harvesting bacteria using ultra-filtration showed an average recovery efficiency of 43% [1] and other studies achieved recovery rates greater than 50% [2]. In this study, an enhanced ceramic micro-filter with 0.14 μm pore size was proposed and demonstrated to optimize the concentration of E.coli. A high recovery rate (mean value >90%) and a high volumetric concentration ratio (>100) were achieved. Known quantities (104 to 106 CFU/ml) of E.coli cells were spiked to different amounts of phosphate buffered saline (0.1 to 1 L), and then concentrated to a final retentate of 5 ml to 10 ml. An average recovery efficiency of 95.3% with a standard deviation of 5.6% was achieved when the volumetric con- centration ratio was 10. No significant recovery rate loss was indicated when the volumetric concentration ratio reached up to 100. The effects of multiple parameters on E.coli recovery rate were also studied. The obtained results indicated that the optimized ceramic micro- filtration system can successfully concentrate E.coli cells in water with an average recovery rate of 90.8%.

Quantification of Internal Filtration in Hollow Fiber Hemodialyzers with Medium Cut-Off Membrane.

PubMed

Lorenzin, Anna; Neri, Mauro; Lupi, Andrea; Todesco, Martina; Santimaria, Monica; Alghisi, Alberta; Brendolan, Alessandra; Ronco, Claudio

2018-06-08

Inadequate removal of molecules between 5 and 50 KDa may cause long-term complication in chronic hemodialysis. Medium cut-off (MCO) is a new class of membranes with enhanced sieving properties and negligible albumin loss. MCO membrane makes it possible to perform expanded hemodialysis (HDx), a technique based on high internal filtration (IF).The present study is designed to quantify IF in 2 MCO dialyzers (Theranova 400 and 500, Baxter, Deerfield, USA) using a nuclear imaging technique previously validated. Blood and dialysate compartment pressure drop along with transmembrane pressure; they were measured in a closed in vitro circuit with human blood (blood flow [QB] = 300 and 400 mL/min; dialysate flow 500 mL/min; net ultrafiltration rate 0 mL/min). A non-diffusible marker molecule (albumin macro-aggregates labeled with 99Tc metastable) was injected in the blood compartment and nuclear emission was recorded by a gamma camera. Relative variations in the concentration of the marker molecule along the length of the filter were used to calculate local cross filtration. Based on marker concentration profiles, IF was estimated. For Theranova 400, IF were 29.7 and 41.6 mL/min for QB of 300 and 400 mL/min. For Theranova 500, IF were 31.6 and 53.1 mL/min for QB of 300 and 400 mL/min respectively. MCO membrane provides significant amounts of IF due to the particular combination between hydraulic permeability of the membrane and reduced inner diameter of the fibers. High IF combined with enhanced sieving profile of MCO membrane leads to improved removal of a wider spectrum of uremia retention molecules in HDx, without requiring complex equipment. © 2018 S. Karger AG, Basel.

Low temperature and Daphnia-associated infochemicals promote colony formation of Scenedesmus obliquus and its harvesting.

PubMed

Zhu, Xuexia; Yang, Jingwen; Zhang, Xingxing; Zhang, Lu; Wang, Xiaojun; Huang, Yuan; Yang, Zhou

2017-01-01

To explore the combined effects of temperature and Daphnia-associated infochemicals on colony formation of Scenedesmus obliquus to faciliate harvesting the algal biomass. A three-parameter modified Gaussian model fitted the changes of the number of cells per particle in S. obliquus induced by Daphnia culture filtrate well under any temperature. Decreases in temperature enhanced the induced-colony formation of Scenedesmus. The maximum colony size at 15-25 °C was significantly larger than those at 30-35 °C. An additional 1 or 2 days at low temperature was needed to reach the maximum colony size, which indicates the best harvest time for algal biomass. Induced-colony formation of Scenedesmus by Daphnia culture filtrate at 15-25 °C is recommended to settle algal cells. This condition facilitates harvesting the biomass.

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 indicates that forearm and calf measurement sites are not interchangeable when bedside assessing fluid filtration by VCP in nonsedated perioperative patients. Considering that only forearm fluid filtration was related to the presence of edema, forearm measurement site should be chosen as a primary site for assessing fluid filtration. PMID:28248863

A case study of Membrane Testing, Integrity and Estimations of Log Removal Value per the Long Term 2 Enhanced Surface Water Treatment Rule.

EPA Science Inventory

The SWTR-LT2 Rule addresses the use of membranes that may be used to achieve credits for the reduction of Cryptosporidium. The LT2 Rule requires product-specific testing of membranes, considered an alternative filtration technology by the rule. LT2 Rule allows the product speci...

Flocculation of wheat straw soda lignin by hemoglobin and chicken blood: Effects of cationic polymer or calcium chloride

USDA-ARS?s Scientific Manuscript database

Flocculation can be used to separate non-sulfonated lignin from base hydrolyzed biomass. In the industrial process, the lignin is isolated by filtration and washed with water. Some of the lignin is lost in the wash water, and flocculation can be used to recover this lignin. Several ways of enhanc...

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

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 attenuation in line with those reported for other models for radiology or mammography. Conclusions: A new version of the TASMIP model for the estimation of x-ray spectra in microfocus x-ray sources has been developed and validated experimentally. Similarly to other versions of TASMIP, the estimation of spectra is very simple, involving only the evaluation of polynomial expressions.« less

In-Line Filtration Reduces Postoperative Venous Peripheral Phlebitis Associated With Cannulation: A Randomized Clinical Trial.

PubMed

Villa, Gianluca; Chelazzi, Cosimo; Giua, Rosa; Tofani, Lorenzo; Zagli, Giovanni; Boninsegni, Paolo; Pinelli, Fulvio; De Gaudio, A Raffaele; Romagnoli, Stefano

2018-04-23

Peripheral venous cannulation is an everyday practice of care for patients undergoing anesthesia and surgery. Particles infused with intravenous fluids (eg, plastic/glass/drugs particulate) contribute to the pathogenesis of peripheral phlebitis. The aim of this study is to demonstrate the efficacy of in-line filtration in reducing the incidence of postoperative phlebitis associated with peripheral short-term vascular access. In this controlled trial, 268 surgical patients were randomly assigned to in-line filtration and standard care (NCT03193827). The incidence of phlebitis (defined as visual infusion phlebitis [VIP] score, ≥2) within 48 hours was compared between the 2 groups, as well as the onset and severity of phlebitis and the reasons for removal of the cannula. The lifespan of venous cannulae was compared for the in-line filter and no-filter groups through a Kaplan-Meier curve. The incidence of phlebitis within 48 hours postoperatively was 2.2% and 26.9% (difference, 25% [95% confidence interval {CI}, 12%-36%]; odds ratio, 0.05 [0.01-0.15]), respectively, for the in-line filter and no-filter groups (P < .001). From 24 to 96 hours postoperatively, patients in the no-filter group had higher VIP scores than those in in-line filter group (P < .001). Venous cannulae in the in-line filter group exhibited prolonged lifespan compared to those in the no-filter group (P = .01). In particular, 64 (47.8%) of cannulae in the in-line filter group and 56 (41.8%) of those in the no-filter group were still in place at 96 hours postoperatively. At the same time point, patients with a VIP score <3 were 100% in the in-line filter group and only 50% for the no-filter group. In-line filtration was a protective factor for postoperative phlebitis (hazard ratio, 0.05 [95% CI, 0.014-0.15]; P < .0001) and cannula removal (hazard ratio, 0.7 [95% CI, 0.52-0.96]; P = .02). In-line filtration has a protective effect for postoperative phlebitis and prolongs cannula lifespan during peripheral venous cannulation in surgical patients.

Effect of coffee filtrate, methylglyoxal, glyoxal, and caffeine on Salmonella typhimurium and S. enteritidis survival in ground chicken breasts.

PubMed

Maletta, Anne B; Were, Lilian M

2012-02-01

The antimicrobial effect of roasted coffee filtrate (CF) and dicarbonyls on Salmonella Typhimurium and Salmonella Enteritidis in raw ground chicken breast meat (GCB) was investigated. Coffee was brewed and filtered before addition to GCB. Coffee filtrate with and without added caffeine, methylglyoxal, and/or glyoxal was added to GCB and then inoculated with Salmonella Typhimurium and Salmonella Enteritidis. Ground chicken samples were stomached with peptone water at days 1, 3, 5, and 7, plated on XLD agar with a TSA overlay, and Salmonella survivors were enumerated. CF alone gave less than a 1 Log reduction in all runs compared to control GCB with no treatment. Methylglyoxal (2.28 mg/g GCB) had the greatest antimicrobial effect against Salmonella Typhimurium and Salmonella Enteritidis in GCB with average Log reductions of 2.27 to 3.23, respectively, over the 7 d duration of the experiment compared to control GCB with no treatment. A 1 Log reduction was observed in GCB with CF, 0.93 mg glyoxal, and 1 mg caffeine/g chicken compared to the control and GCB with only CF. Heat-produced coffee compounds could potentially reduce Salmonella in retail ground chicken and chicken products. © 2011 Institute of Food Technologists®

Lipase pre-hydrolysis enhance anaerobic biodigestion of soap stock from an oil refining industry.

PubMed

Cherif, Slim; Aloui, Fathi; Carrière, Frédéric; Sayadi, Sami

2014-01-01

A novel alcalophilic Staphylococcus haemolyticus strain with the lipolytic activity was used to perform enzymatic hydrolysis pretreatment of soap stock: a lipid rich solid waste from an oil refining industry. The culture liquid of the selected bacteria and an enzymatic preparation obtained by precipitation with ammonium sulphate from a filtrate of the same culture liquid were used for enzymatic pretreatment. The hydrolysis was carried with different incubation concentrations (10, 20 and 30%) of soap stock and the pretreatment efficiency was verified by running comparative biodegradability tests (crude and treated lipid waste). All pretreated assays showed higher reaction rate compared to crude lipid waste, which was confirmed by the increased levels of biogas production. The pretreatment of solutions containing 10% emulsified soap stock was optimized for 24 h hydrolysis time, enabling high-biogaz formation (800 ml). The use of enzymatic pre-treatment seemed to be a very promising alternative for treating soap stock having high fat contents.

Monolith filter apparatus and membrane apparatus, and method using same

DOEpatents

Goldsmith, Robert L [Wayland, MA

2012-04-03

A filtration apparatus that separates a liquid feedstock mixed with a gas into filtrate and retentate, the apparatus including at least one filtration device comprised of at least one monolith segment of porous material that defines a plurality of passageways extending longitudinally from a feed face of the structure to a retentate end face. The filtration device contains at least one filtrate conduit within it for carrying filtrate toward a filtrate collection zone, the filtrate conduit providing a path of lower flow resistance than that of alternative flow paths through the porous material of the device. The filtration device can also be utilized as a membrane support for a device for microfiltration, ultrafiltration, nanofiltration, reverse osmosis, or pervaporation. Also disclosed is a method for using such a filtration apparatus.

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.

A two-site filtration model for silica nanoaggregate mobility in porous media under high salinity conditions

NASA Astrophysics Data System (ADS)

Taghavy, Amir; Kim, Ijung; Huh, Chun; DiCarlo, David A.

2018-06-01

A variable-viscosity colloid transport simulator is developed to model the mobility behavior of surface-engineered nanosilica aggregates (nSiO2) under high salinity conditions. A two-site (2S) filtration approach was incorporated to account for heterogeneous particle-collector surface interactions. 2S model was then implemented along with the conventional clean bed filtration (CFT) and maximum retention capacity (MRC) particle filtration models to simulate the results of a series of column tests conducted in brine (8% wt. NaCl and 2% wt. CaCl2)-saturated Ottawa sand columns at various pore velocities (7 to 71 m/day). Simulation results reveal the superiority of the MRC and 2S model classes over CFT model with respect to numerical performance criteria; a general decrease of normalized sum of squared residuals (ca. 20-90% reduction) and an enhanced degree of normality of model residuals were detected for 2S and MRC over CFT in all simulated experiments. Based on our findings, conformance with theories underpinning colloid deposition in porous media was the ultimate factor that set 2S and MRC model classes apart in terms of explaining the observed mobility trends. MRC and 2S models were evaluated based on the scaling of the fitted maximum retention capacity parameter with variation of experimental conditions. Two subclasses of 2S that consider a mix of favorable and unfavorable attachment sites with irreversible attachment to favorable sites (with and without physical straining effects) were found most consistent with filtration theory and shadow zone predictions, yielding theoretical conformity indices of 0.6 and higher, the highest among all implemented models. An explanation for such irreversible favorable deposition sites on the surface of silica nanoaggregates might be a partial depletion of stabilizing steric forces that had led to the formation of these aggregates.

Sci-Thur AM: YIS – 07: Optimizing dual-energy x-ray parameters using a single filter for both high and low-energy images to enhance soft-tissue imaging

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

Bowman, Wesley; Sattarivand, Mike

Objective: To optimize dual-energy parameters of ExacTrac stereoscopic x-ray imaging system for lung SBRT patients Methods: Simulated spectra and a lung phantom were used to optimize filter material, thickness, kVps, and weighting factors to obtain bone subtracted dual-energy images. Spektr simulations were used to identify material in the atomic number (Z) range [3–83] based on a metric defined to separate spectrums of high and low energies. Both energies used the same filter due to time constraints of image acquisition in lung SBRT imaging. A lung phantom containing bone, soft tissue, and a tumor mimicking material was imaged with filter thicknessesmore » range [0–1] mm and kVp range [60–140]. A cost function based on contrast-to-noise-ratio of bone, soft tissue, and tumor, as well as image noise content, was defined to optimize filter thickness and kVp. Using the optimized parameters, dual-energy images of anthropomorphic Rando phantom were acquired and evaluated for bone subtraction. Imaging dose was measured with dual-energy technique using tin filtering. Results: Tin was the material of choice providing the best energy separation, non-toxicity, and non-reactiveness. The best soft-tissue-only image in the lung phantom was obtained using 0.3 mm tin and [140, 80] kVp pair. Dual-energy images of the Rando phantom had noticeable bone elimination when compared to no filtration. Dose was lower with tin filtering compared to no filtration. Conclusions: Dual-energy soft-tissue imaging is feasible using ExacTrac stereoscopic imaging system utilizing a single tin filter for both high and low energies and optimized acquisition parameters.« less

Seasonal variations on the residence times and partitioning of short-lived radionuclides (234Th, 7Be and 210Pb) and depositional fluxes of 7Be and 210Pb in Tampa Bay, Florida

USGS Publications Warehouse

Baskaran, M.; Swarzenski, P.W.

2007-01-01

Historically, Tampa Bay has been impacted heavily by a wide range of anthropogenic perturbations that may include, agricultural-, shipping-, phosphate mining/distribution-related activities, as well as a burgeoning coastal population. Due to the presence of U-rich underlying sediments, elevated activities of U- and Th-series daughter products may be naturally released into this system. This region is also known for summer thunderstorms and corresponding increases in precipitation and surface water runoff. Only limited work has been conducted on the partitioning of particle-reactive radionuclides (such as 7Be, 210Pb, and 234Th) in such a dynamic coastal system. We investigated both the removal residence time and partitioning of these radionuclides between filter-retained particulate matter (≥ 0.5 μm) and the filtrate ( Our results indicate that the partitioning of 7Be, 210Pb, and 234Th between filtrate and filter-retained phase is controlled foremost by enhanced bottom resuspension events during summer thunderstorms. As a consequence, no significant relationship exists between the distribution coefficients (Kd values) of these isotopes and the concentration of suspended particulate matter (SPM). Relatively faster recycling rates of atmospheric water vapor derived from the ocean results in lower atmospheric depositional fluxes of 210Pb to the study site than predicted. The relationship between 7Be and 210Pb in bulk (wet + dry) deposition is compared to their respective water column activities. The residence times of particulate and dissolved 234Th, 7Be and 210Pb, as well the distribution coefficients of these radionuclides, are then compared to values reported in other coastal systems.

Effects of GAC layer on the performance of gravity-driven membrane filtration (GDM) system for rainwater recycling.

PubMed

Ding, An; Wang, Jinlong; Lin, Dachao; Zeng, Rong; Yu, Shengping; Gan, Zhendong; Ren, Nanqi; Li, Guibai; Liang, Heng

2018-01-01

Gravity-driven membrane filtration (GDM) is promising for decentralized rainwater recycling, owing to low maintenance and energy consumption. However, the organic removal by GDM process is sometimes undesirable and the quality of the permeate cannot meet the standard of water reuse. To improve this, granular activate carbon (GAC) was added as a particle layer on the membrane surface of GDM system. Additionally, a system with sand addition and a system with no particle addition were trialed as comparisons, to study the combined effects of particle hindering and adsorption on the removal efficacy of organics and the development of permeate flux. Results showed that GDM with a GAC layer improved removal efficiency of organics by 25%, and that GAC enhanced removal of florescent compounds (e.g., aromatic proteins, tryptophan proteins and humics), compared with the other two systems. Additionally, the permeate flux in three systems stabilized after Day 25, and kept stable until the end of the operation. However, the presence of GAC layer decreased the level of stable flux (3.2 L/m 2 h) compared with the control system (4.5 L/m 2 h). The factors responsible for the lower flux and severe membrane fouling in GAC layer assisted system were the combined effects of particle and adsorption which led to a denser bio-fouling layer with higher amount of biomass and extracellular polymeric substances contents (proteins and polysaccharides). Resistance distribution analyses revealed that GAC layer mainly increased hydraulically reversible resistance (occupied 93%) of the total resistance, indicating that the flux could be recovered easily by simple physical cleaning. Copyright © 2017 Elsevier Ltd. All rights reserved.

Effects of filtration through Sephadex columns improve overall quality parameters and "in vivo" fertility of subfertile refrigerated boar-semen.

PubMed

Ramió-Lluch, L; Balasch, S; Bonet, S; Briz, M; Pinart, E; Rodríguez-Gil, J E

2009-10-01

This study was performed to test the effects of filtration through several chromatographic resins on the semen quality parameters (percentages of viability, altered acrosomes and morphological abnormalities, motion characteristics and the response to the Osmotic Resistance Test) of boar ejaculates of poor quality. Our results indicate that filtration through a non-ionic Sephadex resin bed (Sephadex G-15), combined with a glasswool subjection bed, induced an overall improvement of semen quality parameters, especially seen in a significant (P<0.05) decrease in the percentages of morphological abnormalities and an increase of several motility parameters related to velocity and linearity. Similar results, although less intense, were observed when the filtration through G-15 resin was accompanied by an ionically neutral polypropylene disk bed instead of glasswool. On the other hand, filtration through two separate ion-exchange Sephadex resins, cationic C-50 and anionic A-50, have less beneficial, and even detrimental, effects on boar-semen quality. In all cases, filtration was accompanied by a significant (P<0.01) decrease in the final concentration of the samples. Ultrastructural and lectin studies showed that the interaction between sperm and chromatographic resins depends on the resin type utilized, and in the case of G-15 it seems that it works by trapping that sperm with not enough strength to overcome the physical resistance associated with chromatographic particles. When semen of poor quality was filtered through G-15 resin and then was utilized for "in vivo" fertility trials, a significant (P<0.05) increase in the percentage of fertility was observed, when compared with the same, but unfiltered, samples. In summary, our results strongly indicate that filtration through ionically inert, Sephadex chromatographic resins could be a very useful and practical method to improve both boar-semen quality and fertilizing ability, especially from mediocre and/or subfertile samples.

Experimentally determined spectral optimization for dedicated breast computed tomography.

PubMed

Prionas, Nicolas D; Huang, Shih-Ying; Boone, John M

2011-02-01

The current study aimed to experimentally identify the optimal technique factors (x-ray tube potential and added filtration material/thickness) to maximize soft-tissue contrast, microcalcification contrast, and iodine contrast enhancement using cadaveric breast specimens imaged with dedicated breast computed tomography (bCT). Secondarily, the study aimed to evaluate the accuracy of phantom materials as tissue surrogates and to characterize the change in accuracy with varying bCT technique factors. A cadaveric breast specimen was acquired under appropriate approval and scanned using a prototype bCT scanner. Inserted into the specimen were cylindrical inserts of polyethylene, water, iodine contrast medium (iodixanol, 2.5 mg/ml), and calcium hydroxyapatite (100 mg/ml). Six x-ray tube potentials (50, 60, 70, 80, 90, and 100 kVp) and three different filters (0.2 mm Cu, 1.5 mm Al, and 0.2 mm Sn) were tested. For each set of technique factors, the intensity (linear attenuation coefficient) and noise were measured within six regions of interest (ROIs): Glandular tissue, adipose tissue, polyethylene, water, iodine contrast medium, and calcium hydroxyapatite. Dose-normalized contrast to noise ratio (CNRD) was measured for pairwise comparisons among the six ROIs. Regression models were used to estimate the effect of tube potential and added filtration on intensity, noise, and CNRD. Iodine contrast enhancement was maximized using 60 kVp and 0.2 mm Cu. Microcalcification contrast and soft-tissue contrast were maximized at 60 kVp. The 0.2 mm Cu filter achieved significantly higher CNRD for iodine contrast enhancement than the other two filters (p = 0.01), but microcalcification contrast and soft-tissue contrast were similar using the copper and aluminum filters. The average percent difference in linear attenuation coefficient, across all tube potentials, for polyethylene versus adipose tissue was 1.8%, 1.7%, and 1.3% for 0.2 mm Cu, 1.5 mm Al, and 0.2 mm Sn, respectively. For water versus glandular tissue, the average percent difference was 2.7%, 3.9%, and 4.2% for the three filter types. Contrast-enhanced bCT, using injected iodine contrast medium, may be optimized for maximum contrast of enhancing lesions at 60 kVp with 0.2 mm Cu filtration. Soft-tissue contrast and microcalcification contrast may also benefit from lower tube potentials (60 kVp). The linear attenuation coefficients of water and polyethylene slightly overestimate the values of their corresponding tissues, but the reported differences may serve as guidance for dosimetry and quality assurance using tissue equivalent phantoms.

Removal of total and antibiotic resistant bacteria in advanced wastewater treatment by ozonation in combination with different filtering techniques.

PubMed

Lüddeke, Frauke; Heß, Stefanie; Gallert, Claudia; Winter, Josef; Güde, Hans; Löffler, Herbert

2015-02-01

Elimination of bacteria by ozonation in combination with charcoal or slow sand filtration for advanced sewage treatment to improve the quality of treated sewage and to reduce the potential risk for human health of receiving surface waters was investigated in pilot scale at the sewage treatment plant Eriskirch, Baden-Wuerttemberg/Germany. To determine the elimination of sewage bacteria, inflowing and leaving wastewater of different treatment processes was analysed in a culture-based approach for its content of Escherichia coli, enterococci and staphylococci and their resistance against selected antibiotics over a period of 17 month. For enterococci, single species and their antibiotic resistances were identified. In comparison to the established flocculation filtration at Eriskirch, ozonation plus charcoal or sand filtration (pilot-scale) reduced the concentrations of total and antibiotic resistant E. coli, enterococci and staphylococci. However, antibiotic resistant E. coli and staphylococci apparently survived ozone treatment better than antibiotic sensitive strains. Neither vancomycin resistant enterococci nor methicillin resistant Staphylococcus aureus (MRSA) were detected. The decreased percentage of antibiotic resistant enterococci after ozonation may be explained by a different ozone sensitivity of species: Enterococcus faecium and Enterococcus faecalis, which determined the resistance-level, seemed to be more sensitive for ozone than other Enterococcus-species. Overall, ozonation followed by charcoal or sand filtration led to 0.8-1.1 log-units less total and antibiotic resistant E. coli, enterococci and staphylococci, as compared to the respective concentrations in treated sewage by only flocculation filtration. Thus, advanced wastewater treatment by ozonation plus charcoal or sand filtration after common sewage treatment is an effective tool for further elimination of microorganisms from sewage before discharge in surface waters. Copyright © 2014 Elsevier Ltd. All rights reserved.

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)

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 permeability.

Ex Vivo Application of Secreted Metabolites Produced by Soil-Inhabiting Bacillus spp. Efficiently Controls Foliar Diseases Caused by Alternaria spp.

PubMed

Ali, Gul Shad; El-Sayed, Ashraf S A; Patel, Jaimin S; Green, Kari B; Ali, Mohammad; Brennan, Mary; Norman, David

2016-01-15

Bacterial biological control agents (BCAs) are largely used as live products to control plant pathogens. However, due to variable environmental and ecological factors, live BCAs usually fail to produce desirable results against foliar pathogens. In this study, we investigated the potential of cell-free culture filtrates of 12 different bacterial BCAs isolated from flower beds for controlling foliar diseases caused by Alternaria spp. In vitro studies showed that culture filtrates from two isolates belonging to Bacillus subtilis and Bacillus amyloliquefaciens displayed strong efficacy and potencies against Alternaria spp. The antimicrobial activity of the culture filtrate of these two biological control agents was effective over a wider range of pH (3.0 to 9.0) and was not affected by autoclaving or proteolysis. Comparative liquid chromatography-mass spectrometry (LC-MS) analyses showed that a complex mixture of cyclic lipopeptides, primarily of the fengycin A and fengycin B families, was significantly higher in these two BCAs than inactive Bacillus spp. Interaction studies with mixtures of culture filtrates of these two species revealed additive activity, suggesting that they produce similar products, which was confirmed by LC-tandem MS analyses. In in planta pre- and postinoculation trials, foliar application of culture filtrates of B. subtilis reduced lesion sizes and lesion frequencies caused by Alternaria alternata by 68 to 81%. Taken together, our studies suggest that instead of live bacteria, culture filtrates of B. subtilis and B. amyloliquefaciens can be applied either individually or in combination for controlling foliar diseases caused by Alternaria species. Copyright © 2016, American Society for Microbiology. All Rights Reserved.

Paper-based silver-nanowire electronic circuits with outstanding electrical conductivity and extreme bending stability.

PubMed

Huang, Gui-Wen; Xiao, Hong-Mei; Fu, Shao-Yun

2014-08-07

Here a facile, green and efficient printing-filtration-press (PFP) technique is reported for room-temperature (RT) mass-production of low-cost, environmentally friendly, high performance paper-based electronic circuits. The as-prepared silver nanowires (Ag-NWs) are uniformly deposited at RT on a pre-printed paper substrate to form high quality circuits via vacuum filtration and pressing. The PFP circuit exhibits more excellent electrical property and bending stability compared with other flexible circuits made by existing techniques. Furthermore, practical applications of the PFP circuits are demonstrated.

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.

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

Enhanced biofiltration of O&G produced water comparing granular activated carbon and nutrients.

PubMed

Riley, Stephanie M; Ahoor, Danika C; Cath, Tzahi Y

2018-05-31

Large volumes of water are required for the development of unconventional oil and gas (O&G) wells. Water scarcity coupled with seismicity induced by deep-well disposal promote new O&G wastewater management strategies, specifically treatment and reuse. One technology that has been proven effective for removal of organic matter and solids is biologically active filtration (BAF) with granular active carbon (GAC); however, further optimization is needed to enhance BAF performance. This study evaluated three GAC media (one spent and two new) and two nutrient-mix supplements for enhanced removal of chemical oxygen demand (COD) and dissolved organic carbon (DOC). Biofilm development was also monitored and correlated to BAF performance. The spent GAC with extant biofilm quickly acclimated to PW and demonstrated up to 92% DOC removal (81% COD) in 24h, while little impact by nutrient addition was observed. In addition, virgin GAC was slow to establish a biofilm, indicating that appropriate GAC selection and pre-developed biofilm is critical for efficient BAF performance. Furthermore, the production of high quality BAF effluent (less than 20mg/L DOC) presents the opportunity to apply BAF as a pretreatment for subsequent desalination-expanding the potential for reuse applications of PW. Copyright © 2017. Published by Elsevier B.V.

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

Potential pancreatic lipase inhibitory activity of an endophytic Penicillium species.

PubMed

Gupta, Mahiti; Saxena, Sanjai; Goyal, Dinesh

2015-02-01

Pancreatic lipase (PL) is considered as one of the safest target for diet-induced anti-obesity drug development. Orlistat is the only PL inhibitor approved for anti-obesity treatment till date. In the process of exploration of new PL inhibitors, we have screened culture filtrates of 70 endophytic fungi of medicinal plants using qualitative as well as quantitative in-vitro PL assays. The qualitative assays indicated potential PL inhibition in only three isolates, namely #57 TBBALM, #33 TBBALM and #1 CSSTOT. Only ethyl acetate extracts of the culture filtrates of these isolates exhibited the PL inhibition. #57 TBBLAM ethyl acetate extract of culture filtrate exhibited potential PL inhibition with an IC50 of 3.69 µg/ml which was comparable to the positive control, i.e. Orlistat exhibiting IC50 value of 2.73 µg/ml. Further molecular phylogenetic tools and morphological studies were used to identify the isolate #57 TBBALM as Penicillium species.

Virus removal by unsaturated wastewater filtration: effects of biofilm accumulation and hydrophobicity.

PubMed

Heistad, A; Scott, T; Skaarer, A M; Seidu, R; Hanssen, J F; Stenström, T A

2009-01-01

Enhanced treatment of septic tank effluent can improve the hydraulic function and performance of infiltration systems and constructed wetlands. By intermittent spray application of septic tank effluent onto a coarse-grained filter media, an unsaturated flow regime beneficial for pathogen removal is created. A column filtration study showed an increase in PRD-1 removal by time of operation with corresponding biofilm accumulation in the filter material. The same increased removal was observed for 1 mum polystyrene beads, irrespective of their hydrophilic/hydrophobic surface properties. A control experiment with sorption of 1 mum hydrophobic and hydrophilic polystyrene beads to different glass surfaces with hydrophobic and hydrophilic properties indicate that mechanisms other than hydrophobic interactions may govern the rate of attachment to the filter media. For a given volumetric flow-rate in the columns, the presence of biofilm altered the hydrodynamic characteristics and this resulted in increased retention time and particle removal.

Renal manifestations in children with Alagille syndrome.

PubMed

Di Pinto, Diana; Adragna, Marta

2018-04-01

Alagille syndrome (AS) is a cholestatic disease secondary to scarcity of interlobular bile ducts. It is associated with extrahepatic manifestations, and renal involvement is frequent. To describe the prevalence, type and outcome of renal pathology in children with AS. The presence and outcome of renal pathology was retrospectively studied in 21 children who met AS criteria. Renal pathology was observed in 18 patients (85.7%): (1) ultrasound variations in 7 patients (6 cases of bilateral renal dysplasia and 1 case of renal agenesis); (2) distal renal tubular acidosis in 2 patients; (3) a drop in glomerular filtration and/or proteinuria in 16 patients. The frequency of a drop in glomerular filtration was similar between patients with and without pathological kidney ultrasound findings. Our study confirms a high prevalence of renal involvement, which enhances the importance of diagnosis and renal function follow-up in children with AS. Sociedad Argentina de Pediatría.

Effects of dialysate flow configurations in continuous renal replacement therapy on solute removal: computational modeling.

PubMed

Kim, Jeong Chul; Cruz, Dinna; Garzotto, Francesco; Kaushik, Manish; Teixeria, Catarina; Baldwin, Marie; Baldwin, Ian; Nalesso, Federico; Kim, Ji Hyun; Kang, Eungtaek; Kim, Hee Chan; Ronco, Claudio

2013-01-01

Continuous renal replacement therapy (CRRT) is commonly used for critically ill patients with acute kidney injury. During treatment, a slow dialysate flow rate can be applied to enhance diffusive solute removal. However, due to the lack of the rationale of the dialysate flow configuration (countercurrent or concurrent to blood flow), in clinical practice, the connection settings of a hemodiafilter are done depending on nurse preference or at random. In this study, we investigated the effects of flow configurations in a hemodiafilter during continuous venovenous hemodialysis on solute removal and fluid transport using computational fluid dynamic modeling. We solved the momentum equation coupling solute transport to predict quantitative diffusion and convection phenomena in a simplified hemodiafilter model. Computational modeling results showed superior solute removal (clearance of urea: 67.8 vs. 45.1 ml/min) and convection (filtration volume: 29.0 vs. 25.7 ml/min) performances for the countercurrent flow configuration. Countercurrent flow configuration enhances convection and diffusion compared to concurrent flow configuration by increasing filtration volume and equilibrium concentration in the proximal part of a hemodiafilter and backfiltration of pure dialysate in the distal part. In clinical practice, the countercurrent dialysate flow configuration of a hemodiafilter could increase solute removal in CRRT. Nevertheless, while this configuration may become mandatory for high-efficiency treatments, the impact of differences in solute removal observed in slow continuous therapies may be less important. Under these circumstances, if continuous therapies are prescribed, some of the advantages of the concurrent configuration in terms of simpler circuit layout and simpler machine design may overcome the advantages in terms of solute clearance. Different dialysate flow configurations influence solute clearance and change major solute removal mechanisms in the proximal and distal parts of a hemodiafilter. Advantages of each configuration should be balanced against the overall performance of the treatment and its simplicity in terms of treatment delivery and circuit handling procedures. Copyright © 2013 S. Karger AG, Basel.

In Vivo Imaging of Tau Pathology Using Magnetic Resonance Imaging Textural Analysis

PubMed Central

Colgan, Niall; Ganeshan, Balaji; Harrison, Ian F.; Ismail, Ozama; Holmes, Holly E.; Wells, Jack A.; Powell, Nick M.; O'Callaghan, James M.; O'Neill, Michael J.; Murray, Tracey K.; Ahmed, Zeshan; Collins, Emily C.; Johnson, Ross A.; Groves, Ashley; Lythgoe, Mark F.

2017-01-01

Background: Non-invasive characterization of the pathological features of Alzheimer's disease (AD) could enhance patient management and the development of therapeutic strategies. Magnetic resonance imaging texture analysis (MRTA) has been used previously to extract texture descriptors from structural clinical scans in AD to determine cerebral tissue heterogeneity. In this study, we examined the potential of MRTA to specifically identify tau pathology in an AD mouse model and compared the MRTA metrics to histological measures of tau burden. Methods: MRTA was applied to T2 weighted high-resolution MR images of nine 8.5-month-old rTg4510 tau pathology (TG) mice and 16 litter matched wild-type (WT) mice. MRTA comprised of the filtration-histogram technique, where the filtration step extracted and enhanced features of different sizes (fine, medium, and coarse texture scales), followed by quantification of texture using histogram analysis (mean gray level intensity, mean intensity, entropy, uniformity, skewness, standard-deviation, and kurtosis). MRTA was applied to manually segmented regions of interest (ROI) drawn within the cortex, hippocampus, and thalamus regions and the level of tau burden was assessed in equivalent regions using histology. Results: Texture parameters were markedly different between WT and TG in the cortex (E, p < 0.01, K, p < 0.01), the hippocampus (K, p < 0.05) and in the thalamus (K, p < 0.01). In addition, we observed significant correlations between histological measurements of tau burden and kurtosis in the cortex, hippocampus and thalamus. Conclusions: MRTA successfully differentiated WT and TG in brain regions with varying degrees of tau pathology (cortex, hippocampus, and thalamus) based on T2 weighted MR images. Furthermore, the kurtosis measurement correlated with histological measures of tau burden. This initial study indicates that MRTA may have a role in the early diagnosis of AD and the assessment of tau pathology using routinely acquired structural MR images. PMID:29163005

Towards enhanced automated elution systems for waterborne protozoa using megasonic energy.

PubMed

Horton, B; Katzer, F; Desmulliez, M P Y; Bridle, H L

2018-02-01

Continuous and reliable monitoring of water sources for human consumption is imperative for public health. For protozoa, which cannot be multiplied efficiently in laboratory settings, concentration and recovery steps are key to a successful detection procedure. Recently, the use of megasonic energy was demonstrated to recover Cryptosporidium from commonly used water industry filtration procedures, forming thereby a basis for a simplified and cost effective method of elution of pathogens. In this article, we report the benefits of incorporating megasonic sonication into the current methodologies of Giardia duodenalis elution from an internationally approved filtration and elution system used within the water industry, the Filta-Max®. Megasonic energy assisted elution has many benefits over current methods since a smaller final volume of eluent allows removal of time-consuming centrifugation steps and reduces manual involvement resulting in a potentially more consistent and more cost-effective method. We also show that megasonic sonication of G. duodenalis cysts provides the option of a less damaging elution method compared to the standard Filta-Max® operation, although the elution from filter matrices is not currently fully optimised. A notable decrease in recovery of damaged cysts was observed in megasonic processed samples, potentially increasing the abilities of further genetic identification options upon isolation of the parasite from a filter sample. This work paves the way for the development of a fully automated and more cost-effective elution method of Giardia from water samples. Copyright © 2017 Elsevier B.V. All rights reserved.

Design of poly(vinylidene fluoride)-g-p(hydroxyethyl methacrylate-co-N-isopropylacrylamide) membrane via surface modification for enhanced fouling resistance and release property

NASA Astrophysics Data System (ADS)

Zhao, Guili; Chen, Wei Ning

2017-03-01

Thermo-sensitive polymer poly(N-isopropylacrylamide) (PNIPAAm), hydrophilic polymer poly(hydroxyethyl methacrylate) (PHEMA) and copolymer p(hydroxyethyl methacrylate-co-N-isopropylacrylamide) [P(HEMA-co-NIPAAm)] were synthesized onto poly(vinylidene fluoride) (PVDF) membrane via atom transfer radical polymerization (ATRP) in order to improve not only fouling resistance but also fouling release property. The physicochemical properties of membranes including hydrophilicity, morphology and roughness were examined by contact angle analyzer, scanning electron microscopy (SEM), and atomic force microscopy (AFM), respectively. The antifouling property of membranes was improved remarkably after surface modification according to protein and bacterial adhesion testing, and filtration experiment. Minimum protein adsorption and bacterial adhesion were both obtained on PVDF-g-P(HEMA-co-NIPAAm) membrane, with reduction by 44% and 71% respectively compared to the pristine membrane. The minimum bacterial cells after detachment at 25 °C were observed on the PVDF-g-P(HEMA-co-NIPAAm) membrane with the detachment rate of 77%, indicating high fouling release property. The filtration testing indicated that the copolymer modified membrane exhibited high resistance to protein fouling and the foulant on the surface was released and removed easily by washing, suggesting high fouling release and easy-cleaning capacity. This study provides useful insight in the combined "fouling resistance" and "fouling release" property of P(HEMA-co-NIPAAm) for PVDF membrane modification, even for other types of the membrane in wide application.

Enhanced drinking water supply through harvested rainwater treatment

NASA Astrophysics Data System (ADS)

Naddeo, Vincenzo; Scannapieco, Davide; Belgiorno, Vincenzo

2013-08-01

Decentralized drinking water systems represent an important element in the process of achieving the Millennium Development Goals, as centralized systems are often inefficient or nonexistent in developing countries. In those countries, most water quality related problems are due to hygiene factors and pathogens. A potential solution might include decentralized systems, which might rely on thermal and/or UV disinfection methods as well as physical and chemical treatments to provide drinking water from rainwater. For application in developing countries, decentralized systems major constraints include low cost, ease of use, environmental sustainability, reduced maintenance and independence from energy sources. This work focuses on an innovative decentralized system that can be used to collect and treat rainwater for potable use (drinking and cooking purposes) of a single household, or a small community. The experimented treatment system combines in one compact unit a Filtration process with an adsorption step on GAC and a UV disinfection phase in an innovative design (FAD - Filtration Adsorption Disinfection). All tests have been carried out using a full scale FAD treatment unit. The efficiency of FAD technology has been discussed in terms of pH, turbidity, COD, TOC, DOC, Escherichia coli and Total coliforms. FAD technology is attractive since it provides a total barrier for pathogens and organic contaminants, and reduces turbidity, thus increasing the overall quality of the water. The FAD unit costs are low, especially if compared to other water treatment technologies and could become a viable option for developing countries.

Rat lingual lipase: partial purification, hydrolytic properties, and comparison with pancreatic lipase.

PubMed

Roberts, I M; Montgomery, R K; Carey, M C

1984-10-01

We have partially purified lingual lipase from the serous glands of rat tongue. With a combination of Triton X-100 extraction or Triton X-114 phase-separation techniques, Bio-Bead SM-2 treatment, dialysis, and gel filtration on Sephadex G-200 or Sephacryl S-300, we obtained a sparingly soluble lipid-free protein demonstrating hydrolytic activity against triglycerides and negligible phospholipase or cholesteryl esterase activities. Compared with homogenate, specific activities of the enzyme were enriched 3- to 5-fold prior to gel filtration and 10-fold after gel filtration. Analysis by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and gel filtration under denaturing conditions (6 M guanidine X HCl or 0.1% sodium dodecyl sulfate) revealed one major glycoprotein band with Mr approximately 50,000. Gel filtration of the active enzyme in 0.1% Triton X-100 gave an Mr approximately 270,000-300,000, suggesting extensive self-aggregation. With both tributyrin and triolein, the pH optimum of the purified enzyme was 4.0 and activity extended from pH 2.0 to 8.0. In contrast to purified human pancreatic lipase, lingual lipase hydrolyzed triglyceride emulsions and mixed micelles stabilized with both short-chain (dihexanoyl) and long-chain (egg) lecithin and were inhibited only slightly (18-25%) by micellar concentrations of two common bile salts, taurodeoxycholate and taurocholate. Our results suggest that the hydrolysis of dietary fat by lingual lipase may extend from the pharynx through the esophagus and stomach and into the upper small intestine.

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.

Fuel Efficient Diesel Particulate Filter (DPF) Modeling and Development

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

Stewart, Mark L.; Gallant, Thomas R.; Kim, Do Heui

The project described in this report seeks to promote effective diesel particulate filter technology with minimum fuel penalty by enhancing fundamental understanding of filtration mechanisms through targeted experiments and computer simulations. The overall backpressure of a filtration system depends upon complex interactions of particulate matter and ash with the microscopic pores in filter media. Better characterization of these phenomena is essential for exhaust system optimization. The acicular mullite (ACM) diesel particulate filter substrate is under continuing development by Dow Automotive. ACM is made up of long mullite crystals which intersect to form filter wall framework and protrude from the wallmore » surface into the DPF channels. ACM filters have been demonstrated to effectively remove diesel exhaust particles while maintaining relatively low backpressure. Modeling approaches developed for more conventional ceramic filter materials, such as silicon carbide and cordierite, have been difficult to apply to ACM because of properties arising from its unique microstructure. Penetration of soot into the high-porosity region of projecting crystal structures leads to a somewhat extended depth filtration mode, but with less dramatic increases in pressure drop than are normally observed during depth filtration in cordierite or silicon carbide filters. Another consequence is greater contact between the soot and solid surfaces, which may enhance the action of some catalyst coatings in filter regeneration. The projecting crystals appear to provide a two-fold benefit for maintaining low backpressures during filter loading: they help prevent soot from being forced into the throats of pores in the lower porosity region of the filter wall, and they also tend to support the forming filter cake, resulting in lower average cake density and higher permeability. Other simulations suggest that soot deposits may also tend to form at the tips of projecting crystals due to the axial velocity component of exhaust moving down the filter inlet channel. Soot mass collected in this way would have a smaller impact on backpressure than soot forced into the flow restrictions deeper in the porous wall structure. This project has focused on the development of computational, analytical, and experimental techniques that are generally applicable to a wide variety of exhaust aftertreatment technologies. By helping to develop improved fundamental understanding pore-scale phenomena affecting filtration, soot oxidation, and NOX abatement, this cooperative research and development agreement (CRADA) has also assisted Dow Automotive in continuing development and commercialization of the ACM filter substrate. Over the course of this research project, ACM filters were successfully deployed on the Audi R10 TDI racecar which won the 24 Hours of LeMans endurance race in 2006, 2007, and 2008; and the 12 Hours of Sebring endurance race in 2006 and 2007. It would not have been possible for the R10 to compete in these traditionally gasoline-dominated events without reliable and effective exhaust particulate filtration. These successes demonstrated not only the performance of automotive diesel engines, but the efficacy of DPF technology as it was being deployed around the world to meet new emissions standards on consumer vehicles. During the course of this CRADA project, Dow Automotive commercialized their ACM DPF technology under the AERIFYTM DPF brand.« less

Influence of twin-screw extrusion on soluble arabinoxylans and corn fiber gum from corn fiber.

PubMed

Singkhornart, Sasathorn; Lee, Seul Gi; Ryu, Gi Hyung

2013-09-01

The effect of feed moisture content and screw speed in the extrusion process with and without chemical pretreatment of corn fiber was investigated. Different chemical pretreatment methods (NaOH and H2 SO4 solution) were compared. The improvement of reducing sugar, soluble arabinoxylans (SAX) content and the yield of corn fiber gum was measured. A high reducing sugar content was obtained in the filtrate fraction from the extruded destarched corn fiber (EDCF) with H₂SO₄ pretreatment. Feed moisture content most effectively improved both reducing sugar and SAX content of filtrate. Increasing feed moisture content and screw speed resulted in a higher SAX content in the filtrate of the EDCF with NaOH pretreatment. The SAX content of the residual solid from the EDCF with NaOH pretreatment was higher compared to H₂SO₄ pretreated and unpretreated samples and significantly increased with decreasing feed moisture content. The screw speed did not have a major impact after enzyme hydrolysis. The yield of corn fiber gum was increased by 12% using NaOH pretreatment combined with extrusion process as compared to the destarched corn fiber. The results show the great potential of the extrusion process as an effective pretreatment for disruption the lignocelluloses of corn fiber, leading to conversion of cellulose to glucose and hemicelluloses to SAX and isolation of corn fiber gum. © 2013 Society of Chemical Industry.

Controlling Structure and Properties of High Surface Area Nonwoven Materials via Hydroentangling

NASA Astrophysics Data System (ADS)

Luzius, Dennis

Hydroentangling describes a technique using a series of high-velocity water jets to mechanically interlock and entangle fibers. Over the last decades researchers worked on a fundamental understanding of the process and the factors influencing the properties of the final nonwoven material. Recent studies discovered hydroentangling to be capable to create unique, knot-like structures characterized by high- and low density regions, which are believed to have interesting properties for filtration applications. However, just little is known about the impact of hydroentangling parameters on the properties of filtration media to this day. In this study we report on the effect of various hydroentangling parameters, such as jet spacing, manifold pressure, number of manifolds but also specific energy on the structure and properties of high surface area nonwoven materials. Latter was achieved by different bicomponent fiber technologies and subsequent treatments removing the sacrificial compound from the structure. The highest BET surface area was measured to be 3.5 m2 g-1 and the smallest mean fiber size about 0.5 mum. Hydroentangling with large jet spacing was found to be a parameter significantly enhancing the filtration properties of caustic-treated island-in-the-sea nonwoven materials. Moreover, improved capture efficiencies and reduced pressure drops were achieved by reducing the manifold pressure and therefore specific energy during hydroentangling. Jet spacing but not island count was found to be the dominant factor influencing the structure and properties of island-in-the-sea nonwovens. Contrary to our initial expectations increasing the island count and thus decreasing the fiber size did not result in better filtration properties. Mixed media nonwoven structures made from homocomponent and island-in-the-sea fibers were found to have lower densities, higher air permeabilities and better quality factors compared to island-in-the-sea structures hydroentangled under the exact same conditions. Study showed the specific energy to not be an adequate measure for describing the process-structure relationship in hydroentangling. Hydroentangling with same specific energy but different manifold pressures revealed the structure and properties to be different and the peak manifold pressure to be the dominant parameter. It was further shown that hydroentangling with multiple manifolds but same water pressure influences the structure and properties of mono- and bicomponent nonwoven materials. Hydroentangling with three manifolds having the same water pressure resulted in stronger, less permeable fabrics compared to two manifolds or one manifold with the same water pressure. Necessary hydroentangling intensity for winged and island-in-the-sea nonwoven materials was found to be different. Winged fiber nonwovens required higher manifold pressures and a different energy ratio than island-in-in-the-sea nonwovens. Hydroentangling winged fiber webs with jet spacing larger than 600 mum resulted in materials too weak to withstand the caustic-treatment. Study indicated the charging potential of winged fiber nonwovens to be superior compared to island-in-the-sea-structures. In contrast to winged fiber nonwovens, island-in-the-sea structures showed higher pressure drops after corona discharge. Loading winged fiber nonwovens with potassium chloride revealed caustic-treated, IPA discharged materials to show the highest loading capacity.

PROCESS OF EXTRACTING URANIUM AND RADIUM FROM ORES

DOEpatents

Sawyer, C.W.; Handley, R.W.

1959-07-14

A process is presented for extracting uranium and radium values from a uranium ore which comprises leaching the ore with a ferric chloride solution at an elevated temperature of above 50 deg C and at a pH less than 4; separating the ore residue from the leaching solution by filtration; precipitating the excess ferric iron present at a pH of less than 5 by adding CaCO/sub 3/ to the filtrate; separating the precipitate by filtration; precipitating the uranium present in the filtrate at a Ph less than 6 by adding BaCO/sub 3/ to the filtrate; separating the precipitate by filtration; and precipitating the radium present in the filtrate by adding H/sub 2/SO/sub 4/ to the filtrate.

Comparison of glomerular filtration rate determined by use of single-slice dynamic computed tomography and scintigraphy in cats.

PubMed

Schmidt, David M; Scrivani, Peter V; Dykes, Nathan L; Goldstein, Richard M; Erb, Hollis N; Reeves, Anthony P

2012-04-01

To compare estimation of glomerular filtration rate determined via conventional methods (ie, scintigraphy and plasma clearance of technetium Tc 99m pentetate) and dynamic single-slice computed tomography (CT). 8 healthy adult cats. Scintigraphy, plasma clearance testing, and dynamic CT were performed on each cat on the same day; order of examinations was randomized. Separate observers performed GFR calculations for scintigraphy, plasma clearance testing, or dynamic CT. Methods were compared via Bland-Altman plots and considered interchangeable and acceptable when the 95% limits of agreement (mean difference between methods ± 1.96 SD of the differences) were ≤ 0.7 mL/min/kg. Global GFR differed < 0.7 mL/min/kg in 5 of 8 cats when comparing plasma clearance testing and dynamic CT; the limits of agreement were 1.4 and -1.7 mL/min/kg. The mean ± SD difference was -0.2 ± 0.8 mL/min/kg, and the maximum difference was 1.6 mL/min/kg. The mean ± SD difference (absolute value) for percentage filtration by individual kidneys was 2.4 ± 10.5% when comparing scintigraphy and dynamic CT; the maximum difference was 20%, and the limits of agreement were 18% and 23% (absolute value). GFR estimation via dynamic CT exceeded the definition for acceptable clinical use, compared with results for conventional methods, which was likely attributable to sample size and preventable technical complications. Because 5 of 8 cats had comparable values between methods, further investigation of dynamic CT in a larger sample population with a wide range of GFR values should be performed.

Identification and characterization of kidney transplants with good glomerular filtration rate at 1 year but subsequent progressive loss of renal function.

PubMed

Park, Walter D; Larson, Timothy S; Griffin, Matthew D; Stegall, Mark D

2012-11-15

After the first year after kidney transplantation, 3% to 5% of grafts fail each year but detailed studies of how grafts progress to failure are lacking. This study aimed to analyze the functional stability of kidney transplants between 1 and 5 years after transplantation and to identify initially well-functioning grafts with progressive decline in allograft function. The study included 788 adult conventional kidney transplants performed at the Mayo Clinic Rochester between January 2000 and December 2005 with a minimum graft survival and follow-up of 2.6 years. The modification of diet in renal disease equation for estimating glomerular filtration rate (eGFR(MDRD)) was used to calculate the slope of renal function over time using all available serum creatinine values between 1 and 5 years after transplantation. Most transplants demonstrated good function (eGFR(MDRD) ≥40 mL/min) at 1 year with positive eGFR(MDRD) slope between 1 and 5 years after transplantation. However, a subset of grafts with 1-year eGFR(MDRD) ≥40 mL/min exhibited strongly negative eGFR(MDRD) slope between 1 and 5 years suggestive of progressive loss of graft function. Forty-one percent of this subset reached graft failure during follow-up, accounting for 69% of allograft failures occurring after 2.5 years after transplantation. This pattern of progressive decline in estimated glomerular filtration rate despite good early function was associated with but not fully attributable to factors suggestive of enhanced antidonor immunity. Longitudinal analysis of serial estimated glomerular filtration ratemeasurements identifies initially well-functioning kidney transplants at high risk for subsequent graft loss. For this subset, further studies are needed to identify modifiable causes of functional decline.

Riparian Ecosystem Management at Military Installations: Determination of Impacts and Evaluation of Restoration and Enhancement Strategies

DTIC Science & Technology

2007-06-01

forests , and the water filtration function performed by these ecosystems may be at risk . Maloney, K. O. and J. W. Feminella. 2006. Evaluation of...additions to perennial streams. Phase 1 – Effects of Disturbance In our studies of sedimentation effects on riparian forests , vegetation...riparian forests associated with ephemeral streams. We determined thresholds beyond which both long-term and current rates of sedimentation

Filtration device for rapid separation of biological particles from complex matrices

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

Kim, Sangil; Naraghi-Arani, Pejman; Liou, Megan

2018-01-09

Methods and systems for filtering of biological particles are disclosed. Filtering membranes separate adjacent chambers. Through osmotic or electrokinetic processes, flow of particles is carried out through the filtering membranes. Cells, viruses and cell waste can be filtered depending on the size of the pores of the membrane. A polymer brush can be applied to a surface of the membrane to enhance filtering and prevent fouling.

COMPARING RBF WITH BENCH-SCALE CONVENTIONAL TREATMENT FOR PRECURSOR REDUCTION

EPA Science Inventory

The reduction of disinfection by-product (DBP) precursors upon riverbank filtration (RBF) at three drinking water utilities in the mid-Western United States was compared with that obtained using a bench-scale conventional treatment train on the corresponding river waters. The riv...

Grafting of alginates on UF/NF ceramic membranes for wastewater treatment.

PubMed

Athanasekou, C P; Romanos, G E; Kordatos, K; Kasselouri-Rigopoulou, V; Kakizis, N K; Sapalidis, A A

2010-10-15

The mechanism of heavy metal ion removal in processes involving multi-layered tubular ultrafiltration and nanofiltration (UF/NF) membranes was investigated by conducting retention experiments in both flow-through and cross-flow modes. The prospect of the regeneration of the membranes through an acidic process was also examined and discussed. The UF/NF membranes were functionalised with alginates to develop hybrid inorganic/organic materials for continuous, single pass, wastewater treatment applications. The challenge laid in the induction of additional metal adsorption and improved regeneration capacity. This was accomplished by stabilizing alginates either into the pores or on the top-separating layer of the membrane. The preservation of efficient water fluxes at moderate trans-membrane pressures introduced an additional parameter that was pursued in parallel to the membrane modification process. The deposition and stabilization of alginates was carried out via physical (filtration/cross-linking) and chemical (grafting) procedures. The materials developed by means of the filtration process exhibited a 25-60% enhancement of their Cd(2+) binding capacity, depending on the amount of the filtered alginate solution. The grafting process led to the development of alginate layers with adequate stability under acidic regeneration conditions and metal retention enhancement of 25-180%, depending on the silane involved as grafting agent and the solvent of silanisation. 2010 Elsevier B.V. All rights reserved.

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.

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.

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 attenuation in line with those reported for other models for radiology or mammography. Conclusions: A new version of the TASMIP model for the estimation of x-ray spectra in microfocus x-ray sources has been developed and validated experimentally. Similarly to other versions of TASMIP, the estimation of spectra is very simple, involving only the evaluation of polynomial expressions.« less

Effects of oil on the feeding mechanism of the bowhead whale. Final report

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

Braithwaite, L.F.

1983-06-10

Research was designed to determine the effect of crude oil on the filtration efficiency of bowhead whale (Balaena mysticetus) baleen. An experiment apparatus was constructed with temperature-controlled, circulating sea water moving through a chamber containing mounted baleen plates. All circulating water of the apparatus flowed over and through the hair-fringed stratum of the baleen plates. Efficiency of filtration of living plankters was measured and compared for various kinds and levels of petroleum fouling. The filtering efficiency of the baleen plates decreased when the plates were fouled with Prudhoe Bay crude oil.

Current state of the art for enhancing urine biomarker discovery

PubMed Central

Harpole, Michael; Davis, Justin; Espina, Virginia

2016-01-01

Urine is a highly desirable biospecimen for biomarker analysis because it can be collected recurrently by non-invasive techniques, in relatively large volumes. Urine contains cellular elements, biochemicals, and proteins derived from glomerular filtration of plasma, renal tubule excretion, and urogenital tract secretions that reflect, at a given time point, an individual's metabolic and pathophysiologic state. High-resolution mass spectrometry, coupled with state of the art fractionation systems are revealing the plethora of diagnostic/prognostic proteomic information existing within urinary exosomes, glycoproteins, and proteins. Affinity capture pre-processing techniques such as combinatorial peptide ligand libraries and biomarker harvesting hydrogel nanoparticles are enabling measurement/identification of previously undetectable urinary proteins. Future challenges in the urinary proteomics field include a) defining either single or multiple, universally applicable data normalization methods for comparing results within and between individual patients/data sets, and b) defining expected urinary protein levels in healthy individuals. PMID:27232439

Dried Fruit of the Luffa Sponge as a Source of Chitin for Applications as Skin Substitutes

PubMed Central

Chien, Mei-Yin; Sheu, Ming-Thau; Huang, Yi-You; Chen, Meng-Hsun; Su, Ching-Hua; Liu, Der-Zen

2014-01-01

LUFFACHITIN obtained from the residue of the sponge-like dried fruit of Luffa aegyptiaca was developed as a weavable skin substitute in this study. A chemical analysis revealed that LUFFACHITIN was composed of a copolymer containing N-acetyl-glucosamine (~40%) as a major monomer with a filamentary structure as demonstrated by both optical and scanning electron microscopy. The pulp-like white residue of the sponge-like dried fruit of Luffa aegyptiaca after treatment was then woven into a thin, porous membrane by filtration and lyophilization as a skin substitute for conducting wound-healing study on rats. The results indicated that the LUFFACHITIN membrane showed significant wound-healing enhancement (25 days to complete healing) compared to cotton gauze (>30 days), but not inferior to that of SACCHACHITIN. Furthermore, the LUFFACHITIN membrane had advantages of having a high yield, better physical properties for fabrication, and a more attractive appearance. PMID:24812618

Dried fruit of the Luffa sponge as a source of chitin for applications as skin substitutes.

PubMed

Jiang, Ping-Lun; Chien, Mei-Yin; Sheu, Ming-Thau; Huang, Yi-You; Chen, Meng-Hsun; Su, Ching-Hua; Liu, Der-Zen

2014-01-01

LUFFACHITIN obtained from the residue of the sponge-like dried fruit of Luffa aegyptiaca was developed as a weavable skin substitute in this study. A chemical analysis revealed that LUFFACHITIN was composed of a copolymer containing N-acetyl-glucosamine (~40%) as a major monomer with a filamentary structure as demonstrated by both optical and scanning electron microscopy. The pulp-like white residue of the sponge-like dried fruit of Luffa aegyptiaca after treatment was then woven into a thin, porous membrane by filtration and lyophilization as a skin substitute for conducting wound-healing study on rats. The results indicated that the LUFFACHITIN membrane showed significant wound-healing enhancement (25 days to complete healing) compared to cotton gauze (>30 days), but not inferior to that of SACCHACHITIN. Furthermore, the LUFFACHITIN membrane had advantages of having a high yield, better physical properties for fabrication, and a more attractive appearance.

Performance of diatomite/iron oxide modified nonwoven membrane used in membrane bioreactor process for wastewater reclamation.

PubMed

He, Yueling; Zhang, Wenqi; Rao, Pinhua; Jin, Peng

2014-01-01

This study describes an approach for surface modification of a nonwoven membrane by diatomite/iron oxide to examine its filterability. Analysis results showed that nonwoven hydrophilicity is enhanced. Static contact angle decreases dramatically from 122.66° to 39.33°. Scanning electron micrograph images show that diatomite/iron oxide is attached on nonwoven fiber. X-ray diffraction analysis further proves that the compound is mostly magnetite. Fourier transformed infrared spectra results reveal that two new absorption peaks might be attributed to Si-O and Fe-O, respectively. Modified and original membranes were used in double nonwoven membrane bioreactors (MBRs) for synthetic wastewater treatment. High critical flux, long filtration time, slow trans-membrane pressure rise and stable sludge volume index confirmed the advantages of modified nonwoven. Comparing with original nonwoven, similar effluent qualities are achieved, meeting the requirements for wastewater reclamation.

N-alkylated aminopyrazines for use as hydrophilic optical agents

NASA Astrophysics Data System (ADS)

Poreddy, Amruta R.; Asmelash, Bethel; Galen, Karen P.; Fitch, Richard M.; Shieh, Jeng-Jong; Wilcox, James M.; Schoenstein, Tasha M.; Wojdyla, Jolette K.; Gaston, Kimberly R.; Freskos, John N.; Neumann, William L.; Rajagopalan, Raghavan; Ahn, Hyo-Yang; Kostelc, James G.; Debreczeny, Martin P.; Belfield, Kevin D.; Dorshow, Richard B.

2009-02-01

Rapid assessment of glomerular filtration rate (GFR), which measures the amount of plasma filtered through the kidney within a given time, would greatly facilitate monitoring of renal function for patients at the bedside in the clinic. In our pursuit to develop exogenous fluorescent tracers for real-time monitoring of renal function by optical methods, N-alkylated aminopyrazine dyes and their hydrophilic conjugates based on poly (ethylene glycol) (PEG) were synthesized via reductive amination as the key step. Photophysical properties indicated a bathochromic shift on the order of 50 nm in both absorption and emission compared to naked aminopyrazines which could be very useful in enhancing both tissue penetration as well as easier detection methods. Structure-activity relationship (SAR) and pharmacokinetic (PK) studies, and the correlation of in vivo optical data with plasma PK for measurement of clearance (and hence GFR) are focus of the current investigation.

Reducing bottom anti-reflective coating (BARC) defects: optimizing and decoupling the filtration and dispense process

NASA Astrophysics Data System (ADS)

Brakensiek, Nickolas L.; Martin, Gary; Simmons, Sean; Batchelder, Traci

2006-03-01

Semiconductor device manufacturing is one of the cleanest manufacturing operations that can be found in the world today. It has to be that way; a particle on a wafer today can kill an entire device, which raises the costs, and therefore reduces the profits, of the manufacturing company in two ways: it must produce extra wafers to make up for the lost die, and it has less product to sell. In today's state-of-the-art fab, everything is filtered to the lowest pore size available. This practice is fairly easy for gases because a gas molecule is very small compared to the pore size of the filter. Filtering liquids, especially photochemicals such as photoresists and BARCs, can be much harder because the molecules that form the polymers used to manufacture the photochemicals are approaching the filter pore size. As a result, filters may plug up, filtration rates may drop, pressure drops across the filter may increase, or a filter may degrade. These conditions can then cause polymer shearing, microbubble formation, gel particle formation, and BARC chemical changes to occur before the BARC reaches the wafer. To investigate these possible interactions, an Entegris(R) IntelliGen(R) pump was installed on a TEL Mk8 TM track to see if the filtration process would have an effect on the BARC chemistry and coating defects. Various BARC chemicals such as DUV112 and DUV42P were pumped through various filter media having a variety of pore sizes at different filtration rates to investigate the interaction between the dispense process and the filtration process. The IntelliGen2 pump has the capability to filter the BARC independent of the dispense process. By using a designed experiment to look at various parameters such as dispense rate, filtration rate, and dispense volume, the effects of the complete pump system can be learned, and appropriate conditions can be applied to yield the cleanest BARC coating process. Results indicate that filtration rate and filter pore size play a dramatic role in the defect density on a coated wafer with the actual dispense properties such as dispense wafer speed and dispense time playing a lesser role.

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

Grooved Glaucoma Drainage Devices That Continuously Deliver Cyclosporine A Decrease Postsurgical Scar Formation in Rabbit Eyes.

PubMed

Dai, Zhaoxing; Yu, Xiaobo; Sun, Jianguo; Sun, Xinghuai

2017-03-01

To study the functional outcomes of filtration surgery by implanting improved glaucoma drainage devices (GDDs) comprising surface grooves and a composite coating of cyclosporine A (CsA) and PLGA in experimental rabbit eyes. Improved GDDs were designed and prepared by modifying normal GDD with surface grooves and a CsA-PLGA composite coating. Normal GDDs, grooved GDDs (G-GDDs), and G-GDDs with a CsA-PLGA composite coating (CsA@G-GDD) were implanted into 18 rabbit eyes (six eyes per group). The intraocular pressure (IOP), bleb survival time, bleb morphology, and anterior chamber reactions were assessed for up to 12 weeks after GDD implantation. The IOPs were compared statistically among the three groups. Bleb morphology was quantified using the Indiana Bleb Appearance Grading Scale. Anterior chamber radiography was performed to check whether the filtrating pathway was blocked, and determine the drainage time and diffusion area of the contrast agent. Hematoxylin and eosin staining and immunohistochemistry were conducted to assess how the GDDs slowed or prevented scar formation. The improved GDDs were successfully prepared and implanted in 18 rabbit eyes without severe surgical complications. Bleb survival time was significantly longer and IOP was significantly lower in the G-GDD and CsA@G-GDD groups compared with the GDD group (all, P < 0.001). Blebs were significantly higher in the CsA@G-GDD group than in the GDD and G-GDD groups (P = 0.003). Anterior chamber radiography revealed more unobstructed filtration channels in the CsA@G-GDD group than in the GDD group (P = 0.032). Postsurgical scar formation was less extensive in the G-GDD and CsA@G-GDD groups than in the GDD group. Compared with the normal GDDs, G-GDDs with a CsA-PLGA coating inhibited postsurgical scar formation and improved the surgical success rate, and might represent an alternative to existing glaucoma filtration devices.

Association of Peak Changes in Plasma Cystatin C and Creatinine with Mortality post Cardiac Surgery

PubMed Central

Park, Meyeon; Shlipak, Michael G.; Thiessen-Philbrook, Heather; Garg, Amit X.; Koyner, Jay L.; Coca, Steven G.; Parikh, Chirag R.

2015-01-01

Background Acute kidney injury is a risk factor for mortality in cardiac surgery patients. Plasma cystatin C and creatinine have different temporal profiles in the post-operative setting, but the associations of simultaneous changes in both filtration markers as compared to change in only one marker with prognosis following hospital discharge are not well described. Methods This is a longitudinal study of 1199 high-risk adult cardiac surgery patients in the TRIBE-AKI (Translational Research Investigating Biomarker Endpoints for Acute Kidney Injury) Consortium who survived hospitalization. We examined in-hospital peak changes of cystatin C and creatinine in the 3 days following cardiac surgery. We evaluated associations of these filtration markers with mortality, adjusting for demographics, operative characteristics, medical comorbidities, pre-operative estimated glomerular filtration rate, pre-operative urinary albumin to creatinine ratio, and site. Results During the first 3 days of hospitalization, nearly twice as many patients had a ≥ 25% rise in creatinine (30%) compared to a ≥ 25% peak rise in cystatin C (15%). Those with elevations in either cystatin C or creatinine had higher mortality risk (adjusted hazard ratio cystatin C 1.83 (95% CI 1.4–2.37) and creatinine 1.90 (95% CI 1.32–2.72)) compared with persons who experienced a post-operative decrease in either filtration marker, respectively. Patients who had simultaneous elevations of ≥ 25% in both cystatin C and creatinine were at similar adjusted risk for 3 year mortality (HR 1.79, 95% CI 1.03–3.1) as those with ≥ 25% increase in cystatin C alone (HR 2.2, 95% CI 1.09–4.47). Conclusions Elevations in creatinine post-operatively are more common than elevations in cystatin C. However, elevations in cystatin C appeared to be associated with higher risk of mortality after hospital discharge. PMID:26921980

Association of Peak Changes in Plasma Cystatin C and Creatinine With Death After Cardiac Operations.

PubMed

Park, Meyeon; Shlipak, Michael G; Thiessen-Philbrook, Heather; Garg, Amit X; Koyner, Jay L; Coca, Steven G; Parikh, Chirag R

2016-04-01

Acute kidney injury is a risk factor for death in cardiac surgical patients. Plasma cystatin C and creatinine have different temporal profiles in the postoperative setting, but the associations of simultaneous changes in both filtration markers compared with change in only one marker with prognosis after hospital discharge are not well described. This is a longitudinal study of 1,199 high-risk adult cardiac surgical patients in the TRIBE-AKI (Translational Research Investigating Biomarker Endpoints for Acute Kidney Injury) Consortium who survived hospitalization. We examined in-hospital peak changes of cystatin C and creatinine in the 3 days after cardiac operations. We evaluated associations of these filtration markers with death, adjusting for demographics, operative characteristics, medical comorbidities, preoperative estimated glomerular filtration rate, preoperative urinary albumin-to-creatinine ratio, and site. During the first 3 days of hospitalization, nearly twice as many patients had a 25% or higher rise in creatinine (30%) compared with a 25% or higher peak rise in cystatin C (15%). The risk of death was higher in those with elevations in cystatin C (adjusted hazard ratio [HR], 1.83; 95% confidence interval [CI], 1.4 to 2.37) or creatinine (adjusted HR, 1.90; 95% CI, 1.32 to 2.72) compared with patients who experienced a postoperative decrease in either filtration marker. Patients who had simultaneous elevations of 25% or higher in cystatin C and creatinine were at similar adjusted risk for 3-year mortality (HR, 1.79; 95% CI, 1.03 to 3.1) as those with a 25% or higher increase in cystatin C alone (HR, 2.2; 95% CI, 1.09 to 4.47). Elevations in creatinine postoperatively are more common than elevations in cystatin C. However, elevations in cystatin C appeared to be associated with a higher risk of death after hospital discharge. Copyright © 2016 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.

Impact of ozonation and biological activated carbon filtration on ceramic membrane fouling.

PubMed

Ibn Abdul Hamid, Khaled; Sanciolo, Peter; Gray, Stephen; Duke, Mikel; Muthukumaran, Shobha

2017-12-01

Ozone pre-treatment (ozonation, ozonisation) and biological activated carbon (BAC) filtration pre-treatment for the ceramic microfiltration (CMF) treatment of secondary effluent (SE) were studied. Ozone pre-treatment was found to result in higher overall removal of UV absorbance (UVA 254 ) and colour, and higher permeability than BAC pre-treatment or the combined use of ozone and BAC (O3+BAC) pre-treatment. The overall removal of colour and UVA 254 by ceramic filtration of the ozone pre-treated water was 97% and 63% respectively, compared to 86% and 48% respectively for BAC pre-treatment and 29% and 6% respectively for the untreated water. Ozone pre-treatment, however, was not effective in removal of dissolved organic carbon (DOC). The permeability of the ozone pre-treated water through the ceramic membrane was found to decrease to 50% of the original value after 200 min of operation, compared to approximately 10% of the original value for the BAC pre-treated, O3+BAC pre-treated water and the untreated water. The higher permeability of the ozone pre-treated water was attributed to the excellent removal of biopolymer particles (100%) and high removal of humic substances (84%). The inclusion of a BAC stage between ozone pre-treatment and ceramic filtration was detrimental. The O3+BAC+CMF process was found to yield higher biopolymer removal (96%), lower humic substance (HS) component removal (66%) and lower normalized permeability (0.1) after 200 min of operation than the O3+CMF process (86%, 84% and 0.5 respectively). This was tentatively attributed to the chemical oxidation effect of ozone on the BAC biofilm and adsorbed components, leading to the generation of foulants that are not generated in the O3+CMF process. This study demonstrated the potential of ozone pre-treatment for reducing organic fouling and thus improving flux for the CMF of SE compared to O3+BAC pre-treatment. Copyright © 2017 Elsevier Ltd. All rights reserved.

Achieving a Successful Scale-Down Model and Optimized Economics through Parvovirus Filter Validation using Purified TrueSpikeTM Viruses.

PubMed

De Vilmorin, Philippe; Slocum, Ashley; Jaber, Tareq; Schaefer, Oliver; Ruppach, Horst; Genest, Paul

2015-01-01

This article describes a four virus panel validation of EMD Millipore's (Bedford, MA) small virus-retentive filter, Viresolve® Pro, using TrueSpike(TM) viruses for a Biogen Idec process intermediate. The study was performed at Charles River Labs in King of Prussia, PA. Greater than 900 L/m(2) filter throughput was achieved with the approximately 8 g/L monoclonal antibody feed. No viruses were detected in any filtrate samples. All virus log reduction values were between ≥3.66 and ≥5.60. The use of TrueSpike(TM) at Charles River Labs allowed Biogen Idec to achieve a more representative scaled-down model and potentially reduce the cost of its virus filtration step and the overall cost of goods. The body of data presented here is an example of the benefits of following the guidance from the PDA Technical Report 47, The Preparation of Virus Spikes Used for Viral Clearance Studies. The safety of biopharmaceuticals is assured through the use of multiple steps in the purification process that are capable of virus clearance, including filtration with virus-retentive filters. The amount of virus present at the downstream stages in the process is expected to be and is typically low. The viral clearance capability of the filtration step is assessed in a validation study. The study utilizes a small version of the larger manufacturing size filter, and a large, known amount of virus is added to the feed prior to filtration. Viral assay before and after filtration allows the virus log reduction value to be quantified. The representativeness of the small-scale model is supported by comparing large-scale filter performance to small-scale filter performance. The large-scale and small-scale filtration runs are performed using the same operating conditions. If the filter performance at both scales is comparable, it supports the applicability of the virus log reduction value obtained with the small-scale filter to the large-scale manufacturing process. However, the virus preparation used to spike the feed material often contains impurities that contribute adversely to virus filter performance in the small-scale model. The added impurities from the virus spike, which are not present at manufacturing scale, compromise the scale-down model and put into question the direct applicability of the virus clearance results. Another consequence of decreased filter performance due to virus spike impurities is the unnecessary over-sizing of the manufacturing system to match the low filter capacity observed in the scale-down model. This article describes how improvements in mammalian virus spike purity ensure the validity of the log reduction value obtained with the scale-down model and support economically optimized filter usage. © PDA, Inc. 2015.

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.

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.

Flexibility of Physiological Traits Underlying Inter-Individual Growth Differences in Intertidal and Subtidal Mussels Mytilusgalloprovincialis

PubMed Central

Fernández-Reiriz, María José; Irisarri, Jade; Labarta, Uxio

2016-01-01

Mussel seed (Mytilusgalloprovincialis) gathered from the intertidal and subtidal environments of a Galician embayment (NW, Spain) were maintained in the laboratory during five months to select fast (F) and slow (S) growing mussels. The physiological basis underlying inter-individual growth variations were compared for F and S mussels from both origins. Fast growing seemed to be a consequence of greater energy intake (20% higher clearance and ingestion rate) and higher food absorption rate coupled with low metabolic costs. The enhanced energy absorption (around 65% higher) resulted in 3 times higher Scope for Growth in F mussels (20.5±4.9 J h−1) than S individuals (7.3±1.1 J h−1). The higher clearance rate of F mussels appears to be linked with larger gill filtration surface compared to S mussels. Intertidal mussels showed higher food acquisition and absorption per mg of organic weight (i.e. mass-specific standardization) than subtidal mussels under the optimal feeding conditions of the laboratory. However, the enhanced feeding and digestive rates were not enough to compensate for the initial differences in tissue weight between mussels of similar shell length collected from the intertidal and subtidal environments. At the end of the experiment, subtidal individuals had higher gill efficiency, which probably lead to higher total feeding and absorption rates relative to intertidal individuals. PMID:26849372

[Analysis and characterization of Belamcanda chinensis with space mutagenesis breeding by X-ray fluorescence analysis and X-ray diffraction].

PubMed

Guan, Ying; Ding, Xi-Feng; Wang, Wen-Jing; Guo, Xi-Hua; Zhu, Yan-Ying

2008-02-01

The contents of various elements in the fourth generation Belamcanda chinensis (L.) DC. with space mutagenesis breeding were analyzed and characterized. X-ray fluorescence spectrum analysis (XRF) and powder X-ray diffraction (PXRD) were applied jointly. It was found that the content of K element in the space flight mutagenesis increases 1.03 and 0.31 times, Mg enhances 1.44 and 0.06 times, but Al reduces 38.5% and 85.5% respectively compared to the contents in the ground group and the comparison group, while those of Ca, Mn and Fe enhance 0.95, 0.30 and 0.29 times respectively contrasted to the ground group. Besides, there was discovered the crystal of whewellite in the Belamcanda chinensis (L.) DC. and the content in the ground group is less than that of the outer space and the outer space group, which in turn is less than that of the comparison group. It is concluded that the contents of mineral elements indispensable to body in the space group are closer or superior to the comparison, group as compared to the ground group. In the present paper, a quick and simple appraising method is offered, which may be of great significance to the popularization of the planting outer space Chinese traditional medicine to filtrate more excellent breed and set up norm of quality appraisal.

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)...

Using data from colloid transport experiments to parameterize filtration model parameters for favorable conditions

NASA Astrophysics Data System (ADS)

Kamai, Tamir; Nassar, Mohamed K.; Nelson, Kirk E.; Ginn, Timothy R.

2017-04-01

Colloid filtration in porous media spans across many disciplines and includes scenarios such as in-situ bioremediation, colloid-facilitated transport, water treatment of suspended particles and pathogenic bacteria, and transport of natural and engineered nanoparticles in the environment. Transport and deposition of colloid particles in porous media are determined by a combination of complex processes and forces. Given the convoluted physical, chemical, and biological processes involved, and the complexity of porous media in natural settings, it should not come as surprise that colloid filtration theory does not always sufficiently predict colloidal transport, and that there is still a pressing need for improved predictive capabilities. Here, instead of developing the macroscopic equation from pore-scale models, we parametrize the different terms in the macroscopic collection equation through fitting it to experimental data, by optimizing the parameters in the different terms of the equation. This way we combine a mechanistically-based filtration-equation with empirical evidence. The impact of different properties of colloids and porous media are studied by comparing experimental properties with different terms of the correlation equation. This comparison enables insight about different processes that occur during colloid transport and retention under in porous media under favorable conditions, and provides directions for future theoretical developments.

The application of biotic elicitor on Artemisia annua L. to increase artemisinin content

NASA Astrophysics Data System (ADS)

Darwati, I.; Manohara, D.; Rohimatun; Nurhayati, H.

2018-01-01

Artemisinin-based Combination Therapy (ACT) has been recommended by WHO as an alternative to treat malaria overcoming drug resistance. The secondary metabolic products in plants, including artemisinin, can be increased by utilizing biotic elicitor from fungi. The research was conducted in Gunung Putri Research Installation, Cipanas, West Java from 2010 to 2011. Phytophthora sp. from eggplant and Colletotrichum sp. from Artemisia annua were applied as biotic elicitor. The types of biotic elicitor applied to the plants were 1) the medium of potato dextrose broth were inoculated with fungi and harvested after 10 days (filtrate), 2) powdery mycelium of both fungi. There were 16 treatments: control negative, control positive (uninoculated medium) 1%, 2%, 3% (v/v)], Phytophthora sp. filtrate [1, 2% and 3% (v/v)], Colletotrichum sp. filtrate [1, 2% and 3% (v/v)], Phytophthora sp. mycelium [1%, 2% and 3% (w/v)], Colletotrichum sp mycelium [1%, 2% and 3% (w/v)]. The elicitor application increased plant production by 26.21% and artemisinin yield by 72% compared to control. Furthermore, the artemisinin production of the plants treated with medium inoculated with 2% filtrate of Phytophthora sp (FP2) (25.19 kg/ha) and 1% powdery mycelium of Colletotrichum sp (MC1) (26.42 kg/ha) were higher than control (K) (11.17 kg/ha).

Comparison of m-Endo LES, MacConkey, and Teepol media for membrane filtration counting of total coliform bacteria in water.

PubMed Central

Grabow, W O; du Preez, M

1979-01-01

Total coliform counts obtained by means of standard membrane filtration techniques, using MacConkey agar, m-Endo LES agar, Teepol agar, and pads saturated with Teepol broth as growth media, were compared. Various combinations of these media were used in tests on 490 samples of river water and city wastewater after different stages of conventional purification and reclamation processes including lime treatment, and filtration, active carbon treatment, ozonation, and chlorination. Endo agar yielded the highest average counts for all these samples. Teepol agar generally had higher counts then Teepol broth, whereas MacConkey agar had the lowest average counts. Identification of 871 positive isolates showed that Aeromonas hydrophila was the species most commonly detected. Species of Escherichia, Citrobacter, Klebsiella, and Enterobacter represented 55% of isolates which conformed to the definition of total coliforms on Endo agar, 54% on Teepol agar, and 45% on MacConkey agar. Selection for species on the media differed considerably. Evaluation of these data and literature on alternative tests, including most probable number methods, indicated that the technique of choice for routine analysis of total coliform bacteria in drinking water is membrane filtration using m-Endo LES agar as growth medium without enrichment procedures or a cytochrome oxidase restriction. PMID:394678

Clostridium perfringens Type A Food Poisoning II. Response of the Rabbit Ileum as an Indication of Enteropathogenicity of Strains of Clostridium perfringens in Human Beings

PubMed Central

Strong, Dorothy H.; Duncan, Charles L.; Perna, Giuseppe

1971-01-01

The effect of feeding human beings individual strains of Clostridium perfringens or culture filtrates thereof was examined. The strains selected for challenge included both those which had previously been shown to produce fluid accumulation in the ligated ileum or overt diarrhea when injected into the nonligated ileum of the rabbit, or had produced both, and those which did not regularly produce these responses. Challenge doses prepared by allowing each strain to grow in beef stew for 3 hr at 46 C resulted in a 61% incidence of diarrhea when rabbit-positive cells were used. No diarrhea occurred among the subjects fed rabbit-negative strains prepared in a similar manner. The procedures employed in preparing the challenge dose appeared to influence the results obtained. When cell-free filtrates were fed, 4 of 15 persons consuming filtrates from rabbit-positive strains developed diarrhea. All subjects fed filtrates from rabbit-negative strains remained free from diarrhea. Serological tests were carried out to compare the identity of the strains of C. perfringens consumed by the subjects and those excreted in the feces. Heat resistance measured as D100 values varied greatly among the rabbit-positive strains. PMID:16557937

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.

The use of charcoal in modified cigarette filters for mainstream smoke carbonyl reduction

PubMed Central

Holman, Matthew R.; Ding, Yan S.; Yan, Xizheng; Chan, Michele; Chafin, Dana; Perez, Jose; Mendez, Magaly I.; Cardenas, Roberto Bravo; Watson, Clifford

2017-01-01

Carbonyls are harmful and potentially harmful constituents (HPHCs) in mainstream cigarette smoke (MSS). Carbonyls, including formaldehyde and acrolein, are carcinogenic or mutagenic in a dose-dependent manner. Past studies demonstrate significant reduction of HPHCs by charcoal filtration. However, limits of charcoal filtration and cigarette design have not yet been investigated in a systematic manner. Objective data is needed concerning the feasibility of HPHC reduction in combustible filtered cigarettes. This systematic study evaluates the effect of charcoal filtration on carbonyl reduction in MSS. We modified filters of ten popular cigarette products with predetermined quantities (100–400 mg) of charcoal in a plug-space-plug configuration. MSS carbonyls, as well as total particulate matter, tar, nicotine, carbon monoxide (TNCO), and draw resistance were quantified. Significant carbonyl reductions were observed across all cigarette products as charcoal loading increased. At the highest charcoal loadings, carbonyls were reduced by nearly 99%. Tar and nicotine decreased modestly (<20%) compared to reductions in carbonyls. Increased draw resistance was significant at only the highest charcoal loadings. This work addresses information gaps in the science base that can inform the evaluation of charcoal filtration as an available technological adaptation to cigarette design which reduces levels of carbonyls in MSS. PMID:28238852

Risk factors for requirement of filtration surgery after vitrectomy in patients with proliferative diabetic retinopathy.

PubMed

Sakamoto, Masashi; Hashimoto, Ryuya; Yoshida, Izumi; Maeno, Takatoshi

2018-01-01

We retrospectively reviewed patients with postoperative neovascular glaucoma (NVG) after vitrectomy for proliferative diabetic retinopathy to investigate how variables assessed before, during, and after vitrectomy are associated with the requirement for filtration surgery. The subjects in this retrospective, observational, comparative study were 55 consecutive patients (61 eyes) who underwent vitrectomy for proliferative diabetic retinopathy at Toho University Sakura Medical Center between December 2011 and November 2016, were followed up for at least 6 months after surgery, and developed NVG within 2 years after surgery. They comprised 44 men and 11 women of mean age 52.4±9.1 years, who were followed up for a mean 7.1±6.1 months. We collected data on the following 16 variables: sex, age, history of panretinal photocoagulation completed within 3 months before vitrectomy, presence/absence of a lens, obvious iris/angle neovascularization, tractional retinal detachment, diabetic macular edema, vitreous hemorrhage, visual acuity and intraocular pressure before vitrectomy and at the onset of NVG, glycated hemoglobin, fasting blood glucose, estimated glomerular filtration rate, and use of intraoperative gas tamponade. Logistic regression analysis with the backward elimination method identified preoperative fasting hyperglycemia ( P =0.08), high intraocular pressure at the onset of NVG ( P =0.04), and use of gas tamponade during vitrectomy ( P =0.008) to be significant risk factors for requirement of filtration surgery. Preoperative fasting hyperglycemia, high intraocular pressure at the onset of NVG, and use of gas tamponade during vitrectomy predispose patients to require filtration surgery in the event of postoperative NVG.

In-line filtration minimizes organ dysfunction: new aspects from a prospective, randomized, controlled trial.

PubMed

Boehne, Martin; Jack, Thomas; Köditz, Harald; Seidemann, Kathrin; Schmidt, Florian; Abura, Michaela; Bertram, Harald; Sasse, Michael

2013-02-06

Infused particles induce thrombogenesis, impair microcirculation and modulate immune response. We have previously shown in critically ill children, that particle-retentive in-line filtration reduced the overall complication rate of severe events, length of stay and duration of mechanical ventilation. We now evaluated the influence of in-line filtration on different organ function and thereby elucidated the potential underlying pathophysiological effects of particle infusion. In this single-centre, prospective, randomized controlled trial 807 critically ill children were assigned to either control (n = 406) or filter group (n = 401), the latter receiving in-line filtration for complete infusion therapy. Both groups were compared regarding the differences of incidence rates and its 95% confidence interval (CI) of different organ dysfunction as defined by the International Pediatric Sepsis Consensus Conference 2005. The incidence rates of respiratory (-5.06%; 95% CI, -9.52 to -0.59%), renal (-3.87%; 95% CI, -7.58 to -0.15%) and hematologic (-3.89%; 95% CI, -7.26 to -0.51%) dysfunction were decreased in the filter group. No difference was demonstrated for the occurrence rates of cardiovascular, hepatic, or neurologic dysfunction between both groups. In-line filtration has beneficial effects on the preservation of hematologic, renal and respiratory function in critically ill patients. The presented clinical data further support our hypothesis regarding potential harmful effects of particles. In critically ill patients infused particles may lead to further deterioration of the microcirculation, induce a systemic hypercoagulability and inflammation with consecutive negative effects on organ function. ClinicalTrials.gov number; NCT00209768.

Transport and abatement of fluorescent silica nanoparticle (SiO2 NP) in granular filtration: effect of porous media and ionic strength

NASA Astrophysics Data System (ADS)

Zeng, Chao; Shadman, Farhang; Sierra-Alvarez, Reyes

2017-03-01

The extensive production and application of engineered silica nanoparticles (SiO2 NPs) will inevitably lead to their release into the environment. Granular media filtration, a widely used process in water and wastewater treatment plants, has the potential for NP abatement. In this work, laboratory-scale column experiments were performed to study the transport and retention of SiO2 NPs on three widely used porous materials, i.e., sand, anthracite, and granular activated carbon (GAC). Synthetic fluorescent core-shell SiO2 NPs (83 nm) were used to facilitate NP detection. Sand showed very low capacity for SiO2 filtration as this material had a surface with limited surface area and a high concentration of negative charge. Also, we found that the stability and transport of SiO2 NP were strongly dependent on the ionic strength of the solution. Increasing ionic strength led to NP agglomeration and facilitated SiO2 NP retention, while low ionic strength resulted in release of captured NPs from the sand bed. Compared to sand, anthracite and GAC showed higher affinity for SiO2 NP capture. The superior capacity of GAC was primarily due to its porous structure and high surface area. A process model was developed to simulate NP capture in the packed bed columns and determine fundamental filtration parameters. This model provided an excellent fit to the experimental data. Taken together, the results obtained indicate that GAC is an interesting material for SiO2 NP filtration.

Performance evaluation of different filter media in turbidity removal from water by application of modified qualitative indices.

PubMed

Gholikandi, G Badalians; Dehghanifard, E; Sepehr, M Noori; Torabian, A; Moalej, S; Dehnavi, A; Yari, Ar; Asgari, Ar

2012-01-01

Water filtration units have been faced problems in water turbidity removal related to their media, which is determined by qualitative indices. Moreover, Current qualitative indices such as turbidity and escaping particle number could not precisely determine the efficiency of the media in water filtration, so defining new indices is essential. In this study, the efficiency of Anthracite-Silica and LECA-Silica media in turbidity removal were compared in different operating condition by using modified qualitative indices. The pilot consisted of a filter column (one meter depth) which consisted of a layer of LECA (450 mm depth) and a layer of Silica sand (350 mm depth. Turbidities of 10, 20, and 30 NTU, coagulant concentrations of 4, 8, and 12 ppm and filtration rates of 10, 15, and 20 m/h were considered as variables. The LECA-Silica media is suitable media for water filtration. Averages of turbidity removal efficiencies in different condition for the LECA-Silica media were 85.8±5.37 percent in stable phase and 69.75±3.37 percent in whole operation phase, while the efficiency of total system were 98.31±0.63 and 94.49±2.97 percent, respectively. The LECA layer efficiency in turbidity removal was independent from filtration rates and due to its low head loss; LECA can be used as a proper medium for treatment plants. Results also showed that the particle index (PI) was a suitable index as a substitute for turbidity and EPN indices.

Kidney-inspired algorithm for optimization problems

NASA Astrophysics Data System (ADS)

Jaddi, Najmeh Sadat; Alvankarian, Jafar; Abdullah, Salwani

2017-01-01

In this paper, a population-based algorithm inspired by the kidney process in the human body is proposed. In this algorithm the solutions are filtered in a rate that is calculated based on the mean of objective functions of all solutions in the current population of each iteration. The filtered solutions as the better solutions are moved to filtered blood and the rest are transferred to waste representing the worse solutions. This is a simulation of the glomerular filtration process in the kidney. The waste solutions are reconsidered in the iterations if after applying a defined movement operator they satisfy the filtration rate, otherwise it is expelled from the waste solutions, simulating the reabsorption and excretion functions of the kidney. In addition, a solution assigned as better solution is secreted if it is not better than the worst solutions simulating the secreting process of blood in the kidney. After placement of all the solutions in the population, the best of them is ranked, the waste and filtered blood are merged to become a new population and the filtration rate is updated. Filtration provides the required exploitation while generating a new solution and reabsorption gives the necessary exploration for the algorithm. The algorithm is assessed by applying it on eight well-known benchmark test functions and compares the results with other algorithms in the literature. The performance of the proposed algorithm is better on seven out of eight test functions when it is compared with the most recent researches in literature. The proposed kidney-inspired algorithm is able to find the global optimum with less function evaluations on six out of eight test functions. A statistical analysis further confirms the ability of this algorithm to produce good-quality results.

Insulin induces the correlation between renal blood flow and glomerular filtration rate in diabetes: implications for mechanisms causing hyperfiltration.

PubMed

Pihl, Liselotte; Persson, Patrik; Fasching, Angelica; Hansell, Peter; DiBona, Gerald F; Palm, Fredrik

2012-07-01

Glomerular filtration rate (GFR) and renal blood flow (RBF) are normally kept constant via renal autoregulation. However, early diabetes results in increased GFR and the potential mechanisms are debated. Tubuloglomerular feedback (TGF) inactivation, with concomitantly increased RBF, is proposed but challenged by the finding of glomerular hyperfiltration in diabetic adenosine A(1) receptor-deficient mice, which lack TGF. Furthermore, we consistently find elevated GFR in diabetes with only minor changes in RBF. This may relate to the use of a lower streptozotocin dose, which produces a degree of hyperglycemia, which is manageable without supplemental suboptimal insulin administration, as has been used by other investigators. Therefore, we examined the relationship between RBF and GFR in diabetic rats with (diabetes + insulin) and without suboptimal insulin administration (untreated diabetes). As insulin can affect nitric oxide (NO) release, the role of NO was also investigated. GFR, RBF, and glomerular filtration pressures were measured. Dynamic RBF autoregulation was examined by transfer function analysis between arterial pressure and RBF. Both diabetic groups had increased GFR (+60-67%) and RBF (+20-23%) compared with controls. However, only the diabetes + insulin group displayed a correlation between GFR and RBF (R(2) = 0.81, P < 0.0001). Net filtration pressure was increased in untreated diabetes compared with both other groups. The difference between untreated and insulin-treated diabetic rats disappeared after administering N(ω)-nitro-l-arginine methyl ester to inhibit NO synthase and subsequent NO release. In conclusion, mechanisms causing diabetes-induced glomerular hyperfiltration are animal model-dependent. Supplemental insulin administration results in a RBF-dependent mechanism, whereas elevated GFR in untreated diabetes is mediated primarily by a tubular event. Insulin-induced NO release partially contributes to these differences.

Predicting membrane flux decline from complex mixtures using flow-field flow fractionation measurements and semi-empirical theory.

PubMed

Pellegrino, J; Wright, S; Ranvill, J; Amy, G

2005-01-01

Flow-Field Flow Fractionation (FI-FFF) is an idealization of the cross flow membrane filtration process in that, (1) the filtration flux and crossflow velocity are constant from beginning to end of the device, (2) the process is a relatively well-defined laminar-flow hydrodynamic condition, and (3) the solutes are introduced as a pulse-input that spreads due to interactions with each other and the membrane in the dilute-solution limit. We have investigated the potential for relating FI-FFF measurements to membrane fouling. An advection-dispersion transport model was used to provide 'ideal' (defined as spherical, non-interacting solutes) solute residence time distributions (RTDs) for comparison with 'real' RTDs obtained experimentally at different cross-field velocities and solution ionic strength. An RTD moment analysis based on a particle diameter probability density function was used to extract "effective" characteristic properties, rather than uniquely defined characteristics, of the standard solute mixture. A semi-empirical unsteady-state, flux decline model was developed that uses solute property parameters. Three modes of flux decline are included: (1) concentration polarization, (2) cake buildup, and (3) adsorption on/in pores, We have used this model to test the hypothesis-that an analysis of a residence time distribution using FI-FFF can describe 'effective' solute properties or indices that can be related to membrane flux decline in crossflow membrane filtration. Constant flux filtration studies included the changes of transport hydrodynamics (solvent flux to solute back diffusion (J/k) ratios), solution ionic strength, and feed water composition for filtration using a regenerated cellulose ultrafiltration membrane. Tests of the modeling hypothesis were compared with experimental results from the filtration measurements using several correction parameters based on the mean and variance of the solute RTDs. The corrections used to modify the boundary layer mass transfer coefficient and the specific resistance of cake or adsorption layers demonstrated that RTD analysis is potentially useful technique to describe colloid properties but requires improvements.

The relationship between red blood cell deformability metrics and perfusion of an artificial microvascular network

PubMed Central

Sosa, Jose M.; Nielsen, Nathan D.; Vignes, Seth M.; Chen, Tanya G.; Shevkoplyas, Sergey S.

2013-01-01

The ability of red blood cells (RBC) to undergo a wide range of deformations while traversing the microvasculature is crucial for adequate perfusion. Interpretation of RBC deformability measurements performed in vitro in the context of microvascular perfusion has been notoriously difficult. This study compares the measurements of RBC deformability performed using micropore filtration and ektacytometry with the RBC ability to perfuse an artificial microvascular network (AMVN). Human RBCs were collected from healthy consenting volunteers, leukoreduced, washed and exposed to graded concentrations (0% – 0.08%) of glutaraldehyde (a non-specific protein cross-linker) and diamide (a spectrin-specific protein cross-linker) to impair the deformability of RBCs. Samples comprising cells with two different levels of deformability were created by adding non-deformable RBCs (hardened by exposure to 0.08% glutaraldehyde) to the sample of normal healthy RBCs. Ektacytometry indicated a nearly linear decline in RBC deformability with increasing glutaraldehyde concentration. Micropore filtration showed a significant reduction only for concentrations of glutaraldehyde higher than 0.04%. Neither micropore filtration nor ektacytometry measurements could accurately predict the AMVN perfusion. Treatment with diamide reduced RBC deformability as indicated by ektacytometry, but had no significant effect on either micropore filtration or the AMVN perfusion. Both micropore filtration and ektacytometry showed a linear decline in effective RBC deformability with increasing fraction of non-deformable RBCs in the sample. The corresponding decline in the AMVN perfusion plateaued above 50%, reflecting the innate ability of blood flow in the microvasculature to bypass occluded capillaries. Our results suggest that in vitro measurements of RBC deformability performed using either micropore filtration or ektacytometry may not represent the ability of same RBCs to perfuse microvascular networks. Further development of biomimetic tools for measuring RBC deformability (e.g. the AMVN) could enable a more functionally relevant testing of RBC mechanical properties. PMID:23603326

The relationship between red blood cell deformability metrics and perfusion of an artificial microvascular network.

PubMed

Sosa, Jose M; Nielsen, Nathan D; Vignes, Seth M; Chen, Tanya G; Shevkoplyas, Sergey S

2014-01-01

The ability of red blood cells (RBC) to undergo a wide range of deformations while traversing the microvasculature is crucial for adequate perfusion. Interpretation of RBC deformability measurements performed in vitro in the context of microvascular perfusion has been notoriously difficult. This study compares the measurements of RBC deformability performed using micropore filtration and ektacytometry with the RBC ability to perfuse an artificial microvascular network (AMVN). Human RBCs were collected from healthy consenting volunteers, leukoreduced, washed and exposed to graded concentrations (0-0.08%) of glutaraldehyde (a non-specific protein cross-linker) and diamide (a spectrin-specific protein cross-linker) to impair the deformability of RBCs. Samples comprising cells with two different levels of deformability were created by adding non-deformable RBCs (hardened by exposure to 0.08% glutaraldehyde) to the sample of normal healthy RBCs. Ektacytometry indicated a nearly linear decline in RBC deformability with increasing glutaraldehyde concentration. Micropore filtration showed a significant reduction only for concentrations of glutaraldehyde higher than 0.04%. Neither micropore filtration nor ektacytometry measurements could accurately predict the AMVN perfusion. Treatment with diamide reduced RBC deformability as indicated by ektacytometry, but had no significant effect on either micropore filtration or the AMVN perfusion. Both micropore filtration and ektacytometry showed a linear decline in effective RBC deformability with increasing fraction of non-deformable RBCs in the sample. The corresponding decline in the AMVN perfusion plateaued above 50%, reflecting the innate ability of blood flow in the microvasculature to bypass occluded capillaries. Our results suggest that in vitro measurements of RBC deformability performed using either micropore filtration or ektacytometry may not represent the ability of same RBCs to perfuse microvascular networks. Further development of biomimetic tools for measuring RBC deformability (e.g. the AMVN) could enable a more functionally relevant testing of RBC mechanical properties.

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

Wunderle, K; Wayne State University School of Medicine, Detroit, MI; Godley, A

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

Clinical Relevance of Differences in Glomerular Filtration Rate Estimations in Frail Older People by Creatinine- vs. Cystatin C-Based Formulae.

PubMed

Jacobs, Anne; Benraad, Carolien; Wetzels, Jack; Rikkert, Marcel Olde; Kramers, Cornelis

2017-06-01

The risk of incorrect medication dosing is high in frail older people. Therefore, accurate assessment of the glomerular filtration rate is important. The objective of this study was to compare the estimated glomerular filtration rate using creatinine- and cystatin C-based formulae, the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equations, in frail older people. We hypothesized that frailty determines the difference between the creatinine- and cystatin C-based formulae. The mean difference between CKD-EPI creatinine and cystatin C was determined using (cross-sectional) data of 55 patients (mean age 73 years) admitted to a psychiatric ward for older adults. The level of agreement of these estimations was assessed by a Bland-Altman analysis. In all patients, the Rockwood's Frailty Index was derived and correlated with the mean difference between CKD-EPI creatinine and cystatin C. The mean difference between CKD-EPI creatinine (mean 71.2 mL/min/1.73 m 2 ) and CKD-EPI cystatin C (mean 57.6 mL/min/1.73 m 2 ) was 13.6 mL/min/1.73 m 2 (p < 0.0001). The two standard deviation limit in the Bland-Altman plot was large (43.2 mL/min/1.73 m 2 ), which represents a low level of agreement. The Frailty Index did not correlate with the mean difference between the creatinine- and cystatin C-based glomerular filtration rate (Pearson correlation coefficient 0.182, p = 0.184). There was a significant gap between a creatinine- and cystatin C-based estimation of glomerular filtration rate, irrespective of frailty. The range of differences between the commonly used estimated glomerular filtration rate formulae might result in clinically relevant differences in drug prescription and differences in chronic kidney disease staging.

High-flux ceramic membranes with a nanomesh of metal oxide nanofibers.

PubMed

Ke, Xue Bin; Zheng, Zhan Feng; Liu, Hong Wei; Zhu, Huai Yong; Gao, Xue Ping; Zhang, Li Xiong; Xu, Nan Ping; Wang, Huanting; Zhao, Hui Jun; Shi, Jeffrey; Ratinac, Kyle R

2008-04-24

Traditional ceramic separation membranes, which are fabricated by applying colloidal suspensions of metal hydroxides to porous supports, tend to suffer from pinholes and cracks that seriously affect their quality. Other intrinsic problems for these membranes include dramatic losses of flux when the pore sizes are reduced to enhance selectivity and dead-end pores that make no contribution to filtration. In this work, we propose a new strategy for addressing these problems by constructing a hierarchically structured separation layer on a porous substrate using large titanate nanofibers and smaller boehmite nanofibers. The nanofibers are able to divide large voids into smaller ones without forming dead-end pores and with the minimum reduction of the total void volume. The separation layer of nanofibers has a porosity of over 70% of its volume, whereas the separation layer in conventional ceramic membranes has a porosity below 36% and inevitably includes dead-end pores that make no contribution to the flux. This radical change in membrane texture greatly enhances membrane performance. The resulting membranes were able to filter out 95.3% of 60-nm particles from a 0.01 wt % latex while maintaining a relatively high flux of between 800 and 1000 L/m2.h, under a low driving pressure (20 kPa). Such flow rates are orders of magnitude greater than those of conventional membranes with equal selectivity. Moreover, the flux was stable at approximately 800 L/m2.h with a selectivity of more than 95%, even after six repeated runs of filtration and calcination. Use of different supports, either porous glass or porous alumina, had no substantial effect on the performance of the membranes; thus, it is possible to construct the membranes from a variety of supports without compromising functionality. The Darcy equation satisfactorily describes the correlation between the filtration flux and the structural parameters of the new membranes. The assembly of nanofiber meshes to combine high flux with excellent selectivity is an exciting new direction in membrane fabrication.

Glomerular barrier behaves as an atomically precise bandpass filter in a sub-nanometre regime

NASA Astrophysics Data System (ADS)

Du, Bujie; Jiang, Xingya; Das, Anindita; Zhou, Qinhan; Yu, Mengxiao; Jin, Rongchao; Zheng, Jie

2017-11-01

The glomerular filtration barrier is known as a 'size cutoff' slit, which retains nanoparticles or proteins larger than 6-8 nm in the body and rapidly excretes smaller ones through the kidneys. However, in the sub-nanometre size regime, we have found that this barrier behaves as an atomically precise 'bandpass' filter to significantly slow down renal clearance of few-atom gold nanoclusters (AuNCs) with the same surface ligands but different sizes (Au18, Au15 and Au10-11). Compared to Au25 (∼1.0 nm), just few-atom decreases in size result in four- to ninefold reductions in renal clearance efficiency in the early elimination stage, because the smaller AuNCs are more readily trapped by the glomerular glycocalyx than larger ones. This unique in vivo nano-bio interaction in the sub-nanometre regime also slows down the extravasation of sub-nanometre AuNCs from normal blood vessels and enhances their passive targeting to cancerous tissues through an enhanced permeability and retention effect. This discovery highlights the size precision in the body's response to nanoparticles and opens a new pathway to develop nanomedicines for many diseases associated with glycocalyx dysfunction.

Analysis of multilayer and single layer X-ray detectors for contrast-enhanced mammography using imaging task

NASA Astrophysics Data System (ADS)

Allec, Nicholas; Abbaszadeh, Shiva; Karim, Karim S.

2011-03-01

A multilayer (single-shot) detector has previously been proposed for contrast-enhanced mammography. The multilayer detector has the benefit of avoiding motion artifacts due to simultaneous acquisition of both high and low energy images. A single layer (dual-shot) detector has the benefit of better control over the energy separation since the incident beams can be produced and filtered separately. In this paper the performance of the multilayer detector is compared to that of a single layer detector using an ideal observer detectability index which is determined from an extended cascaded systems model and a defined imaging task. The detectors are assumed to have amorphous selenium direct conversion layers, however the same theoretical techniques used here may be applied to other types of integrating detectors. The anatomical noise caused by variation of glandularity within the breast is known to dominate the noise power spectrum at low frequencies due to its inverse power law dependence and is thus taken into account in our model to provide an accurate estimate of the detectability index. The conditions leading to the optimal detectability index, such as tube voltage, filtration, and weight factor are reported for both detector designs.

Morphine induces albuminuria by compromising podocyte integrity.

PubMed

Lan, Xiqian; Rai, Partab; Chandel, Nirupama; Cheng, Kang; Lederman, Rivka; Saleem, Moin A; Mathieson, Peter W; Husain, Mohammad; Crosson, John T; Gupta, Kalpna; Malhotra, Ashwani; Singhal, Pravin C

2013-01-01

Morphine has been reported to accelerate the progression of chronic kidney disease. However, whether morphine affects slit diaphragm (SD), the major constituent of glomerular filtration barrier, is still unclear. In the present study, we examined the effect of morphine on glomerular filtration barrier in general and podocyte integrity in particular. Mice were administered either normal saline or morphine for 72 h, then urine samples were collected and kidneys were subsequently isolated for immunohistochemical studies and Western blot. For in vitro studies, human podocytes were treated with morphine and then probed for the molecular markers of slit diaphragm. Morphine-receiving mice displayed a significant increase in albuminuria and showed effacement of podocyte foot processes. In both in vivo and in vitro studies, the expression of synaptopodin, a molecular marker for podocyte integrity, and the slit diaphragm constituting molecules (SDCM), such as nephrin, podocin, and CD2-associated protein (CD2AP), were decreased in morphine-treated podocytes. In vitro studies indicated that morphine modulated podocyte expression of SDCM through opiate mu (MOR) and kappa (KOR) receptors. Since morphine also enhanced podocyte oxidative stress, the latter seems to contribute to decreased SDCM expression. In addition, AKT, p38, and JNK pathways were involved in morphine-induced down regulation of SDCM in human podocytes. These findings demonstrate that morphine has the potential to alter the glomerular filtration barrier by compromising the integrity of podocytes.

Tailoring Mechanically Robust Poly(m-phenylene isophthalamide) Nanofiber/nets for Ultrathin High-Efficiency Air Filter

PubMed Central

Zhang, Shichao; Liu, Hui; Yin, Xia; Li, Zhaoling; Yu, Jianyong; Ding, Bin

2017-01-01

Effective promotion of air filtration applications proposed for fibers requires their real nanoscale diameter, optimized pore structure, and high service strength; however, creating such filter medium has proved to be a tremendous challenge. This study first establishes a strategy to design and fabricate novel poly(m-phenylene isophthalamide) nanofiber/nets (PMIA NF/N) air filter via electrospinning/netting. Our strategy results in generation of a bimodal structure including a scaffold of nanofibers and abundant two-dimensional ultrathin (~20 nm) nanonets to synchronously construct PMIA filters by combining solution optimization, humidity regulation, and additive inspiration. Benefiting from the structural features including the true nanoscale diameter, small pore size, high porosity, and nets bonding contributed by the widely distributed nanonets, our PMIA NF/N filter exhibits the integrated properties of superlight weight (0.365 g m−2), ultrathin thickness (~0.5 μm), and high tensile strength (72.8 MPa) for effective air filtration, achieving the ultra-low penetration air filter level of 99.999% and low pressure drop of 92 Pa for 300–500 nm particles by sieving mechanism. The successful synthesis of PMIA NF/N would not only provide a promising medium for particle filtration, but also develop a versatile platform for exploring the application of nanonets in structural enhancement, separation and purification. PMID:28074880

Influence of gas-liquid two-phase flow on angiotensin-I converting enzyme inhibitory peptides separation by ultra-filtration.

PubMed

Charoenphun, Narin; Youravong, Wirote

2017-01-01

Membrane fouling is a major problem in ultra-filtration systems and two-phase flow is a promising technique for permeate flux enhancement. The objective of this research was to study the use of an ultra-filtration (UF) system to enrich angiotensin-I converting enzyme (ACE) inhibitory peptides from tilapia protein hydrolysate. To select the most appropriate membrane and operating condition, the effects of membrane molecular weight cut-off (MWCO), transmembrane pressure (TMP) and cross-flow velocity (CFV) on permeate flux and ACE inhibitory peptide separation were studied. Additionally, the gas-liquid two-phase flow technique was applied to investigate its effect on the process capability. The results showed that the highest ACE inhibitory activity was obtained from permeate of the 1 kDa membrane. In terms of TMP and CFV, the permeate flux tended to increase with TMP and CFV. The use of gas-liquid two-phase flow as indicated by shear stress number could reduce membrane fouling and increase the permeate flux up to 42%, depending on shear stress number. Moreover, the use of a shear stress number of 0.039 led to an augmentation in ACE inhibitory activity of permeates. Operating conditions using a shear stress number of 0.039 were recommended for enrichment of ACE inhibitory peptides. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

Tailoring Mechanically Robust Poly(m-phenylene isophthalamide) Nanofiber/nets for Ultrathin High-Efficiency Air Filter

NASA Astrophysics Data System (ADS)

Zhang, Shichao; Liu, Hui; Yin, Xia; Li, Zhaoling; Yu, Jianyong; Ding, Bin

2017-01-01

Effective promotion of air filtration applications proposed for fibers requires their real nanoscale diameter, optimized pore structure, and high service strength; however, creating such filter medium has proved to be a tremendous challenge. This study first establishes a strategy to design and fabricate novel poly(m-phenylene isophthalamide) nanofiber/nets (PMIA NF/N) air filter via electrospinning/netting. Our strategy results in generation of a bimodal structure including a scaffold of nanofibers and abundant two-dimensional ultrathin (~20 nm) nanonets to synchronously construct PMIA filters by combining solution optimization, humidity regulation, and additive inspiration. Benefiting from the structural features including the true nanoscale diameter, small pore size, high porosity, and nets bonding contributed by the widely distributed nanonets, our PMIA NF/N filter exhibits the integrated properties of superlight weight (0.365 g m-2), ultrathin thickness (~0.5 μm), and high tensile strength (72.8 MPa) for effective air filtration, achieving the ultra-low penetration air filter level of 99.999% and low pressure drop of 92 Pa for 300-500 nm particles by sieving mechanism. The successful synthesis of PMIA NF/N would not only provide a promising medium for particle filtration, but also develop a versatile platform for exploring the application of nanonets in structural enhancement, separation and purification.

Water Filtration

ERIC Educational Resources Information Center

Jacobsen, Erica K.

2004-01-01

A water filtration column is devised by students using a two-liter plastic bottle containing gravel, sand, and activated charcoal, to test the filtration potential of the column. Results indicate that the filtration column eliminates many of the contaminating materials, but does not kill bacteria.

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

Test of precoat filtration technology for treatment of swimming pool water.

PubMed

Christensen, Morten Lykkegaard; Klausen, Morten Møller; Christensen, Peter Vittrup

2018-02-01

The technical performance of a precoat filter was compared with that of a traditional sand filter. Particle concentration and size distribution were measured before and after the filtration of swimming pool water. Both the sand and precoat filters could reduce the particle concentration in the effluent. However, higher particle removal efficiency was generally observed for the precoat filter, especially for particles smaller than 10 μm in diameter. Adding flocculant improved the removal efficiency of the sand filter, resulting in removal efficiencies comparable to those of the precoat filter. Three powders, i.e., two types of perlite (Harbolite ® and Aquatec perlite) and cellulose fibers (Arbocel ® ), were tested for the precoat filter, but no significant difference in particle removal efficiency was observed among them. The maximum efficiency was reached within 30-40 min of filtration. The energy required for the pumps increased by approximately 35% over a period of 14 days. The energy consumption could be reduced by replacing the powder on the filter cloth. The sand filter was backwashed once a week, while the powder on the precoat filter was replaced every two weeks. Under these conditions, it was possible to reduce the water used for cleaning by 88% if the precoat filter was used instead of the sand filter.

Enhanced Wound Healing Using Topically Administered Nanoparticle Encapsulated siRNA

DTIC Science & Technology

2013-11-01

from eye surgery such as LASIK surgery, LASEK surgery, PRK surgery, glaucoma filtration surgery, cataract surgery, or surgery in which the lens...treatment vs . siRNA transfection using the RNAiMAX delivery system from InVitrogen (http://www.invitrogen.com/site/us/en/home/Products-and- Services...consisting of: wounds of the skin; wounds of the eye (including the inhibition of scarring resulting from eye surgery such as LASIK surgery, LASEK surgery

Influence of Renal Impairment on Outcome for Thrombolysis-Treated Acute Ischemic Stroke: ENCHANTED (Enhanced Control of Hypertension and Thrombolysis Stroke Study) Post Hoc Analysis.

PubMed

Carr, Susan J; Wang, Xia; Olavarria, Veronica V; Lavados, Pablo M; Rodriguez, Jorge A; Kim, Jong S; Lee, Tsong-Hai; Lindley, Richard I; Pontes-Neto, Octavio M; Ricci, Stefano; Sato, Shoichiro; Sharma, Vijay K; Woodward, Mark; Chalmers, John; Anderson, Craig S; Robinson, Thompson G

2017-09-01

Renal dysfunction (RD) is associated with poor prognosis after stroke. We assessed the effects of RD on outcomes and interaction with low- versus standard-dose alteplase in a post hoc subgroup analysis of the ENCHANTED (Enhanced Control of Hypertension and Thrombolysis Stroke Study). A total of 3220 thrombolysis-eligible patients with acute ischemic stroke (mean age, 66.5 years; 37.8% women) were randomly assigned to low-dose (0.6 mg/kg) or standard-dose (0.9 mg/kg) intravenous alteplase within 4.5 hours of symptom onset. Six hundred and fifty-nine (19.8%) patients had moderate-to-severe RD (estimated glomerular filtration rate, <60 mL/min per 1.73 m 2 ) at baseline. The impact of RD on death or disability (modified Rankin Scale scores, 2-6) at 90 days, and symptomatic intracerebral hemorrhage, was assessed in logistic regression models. Compared with patients with normal renal function (>90 mL/min per 1.73 m 2 ), those with severe RD (<30 mL/min per 1.73 m 2 ) had increased mortality (adjusted odds ratio, 2.07; 95% confidence interval, 0.89-4.82; P =0.04 for trend); every 10 mL/min per 1.73 m 2 lower estimated glomerular filtration rate was associated with an adjusted 9% increased odds of death from thrombolysis-treated acute ischemic stroke. There was no significant association with modified Rankin Scale scores 2 to 6 (adjusted odds ratio, 1.03; 95% confidence interval, 0.62-1.70; P =0.81 for trend), modified Rankin Scale 3 to 6 (adjusted odds ratio, 1.20; 95% confidence interval, 0.72-2.01; P =0.44 for trend), or symptomatic intracerebral hemorrhage, or any heterogeneity in comparative treatment effects between low-dose and standard-dose alteplase by RD grades. RD is associated with increased mortality but not disability or symptomatic intracerebral hemorrhage in thrombolysis-eligible and treated acute ischemic stroke patients. Uncertainty persists as to whether low-dose alteplase confers benefits over standard-dose alteplase in acute ischemic stroke patients with RD. URL: http://www.clinicaltrials.gov. Unique identifier: NCT01422616. © 2017 American Heart Association, Inc.

Exploration of permeability and antifouling performance on modified cellulose acetate ultrafiltration membrane with cellulose nanocrystals.

PubMed

Lv, Jinling; Zhang, Guoquan; Zhang, Hanmin; Yang, Fenglin

2017-10-15

Cellulose nanocrystals (CNCs) were introduced into cellulose diacetate (CDA) matrix via immerged phase-inversion process, aiming to improve the filtration and antifouling performance of CNCs/CDA blending membrane. The effects of CNCs on membrane morphologies, hydrophilicity, permeability and antifouling property were investigated. Results showed that the incorporation of CNCs into CDA membrane could effectively enhance the permeability and antifouling property of CNCs/CDA blending membrane by optimizing membrane microstructure and improving membrane hydrophilicity. A high pure water flux of 173.8L/m 2 h was achieved for the CNCs/CDA blending membrane at 200KPa, which is 24 times that of the CDA membrane (7.2L/m 2 h). The bovine serum albumin (BSA) adsorption amount of the CNCs/CDA blending membrane decreased about 48% compared to that of the CDA membrane. Additionally, the CNCs/CDA blending membrane exhibited better antifouling performance with the flux recovery ratio (FRR) of 89.5% after three fouling cycles, compared to 59.7% for the CDA membrane. Copyright © 2017 Elsevier Ltd. All rights reserved.

Fouling potential evaluation of soluble microbial products (SMP) with different membrane surfaces in a hybrid membrane bioreactor using worm reactor for sludge reduction.

PubMed

Li, Zhipeng; Tian, Yu; Ding, Yi; Chen, Lin; Wang, Haoyu

2013-07-01

The fouling characteristics of soluble microbial products (SMP) in the membrane bioreactor coupled with Static Sequencing Batch Worm Reactor (SSBWR-MBR) were tested with different types of membranes. It was noted that the flux decrements of S-SMP (SMP in SSBWR-MBR) with cellulose acetate (CA), polyvinylidene fluoride (PVDF) and polyether sulfones (PES) membranes were respectively 6.7%, 8.5% and 9.5% lower compared to those of C-SMP (SMP in Control-MBR) with corresponding membranes. However, for both the filtration of the C-SMP and S-SMP, the CA membrane exhibited the fastest diminishing rate of flux among the three types of membranes. The surface morphology analysis showed that the CA membrane exhibited more but smaller protuberances compared to the PVDF and PES. The second minimums surrounding each protruding asperity on CA membrane were more than those on the PVDF and PES membranes, enhancing the attachment of SMP onto the membrane surface. Copyright © 2013 Elsevier Ltd. All rights reserved.

[Physiological analysis of various types of osmotic diuresis].

PubMed

Marina, A S; Kutina, A V; Natochin, Iu V

2011-12-01

Efficacy of drugs reduced proximal reabsorption was compared in experiments with female Wistar rats. Urine flow rate for the 1st h of experiment was enhanced after polyethylene glycol-400 (PEG) and 6% Na2SO4 infusion by over 30-fold, exenatide--40-fold, glycerol--11-fold as compared with the control. The maximal values of Na+ excretion were observed during Na2SO4 and exenatide administration (280 +/- 31 micromol/h vs. 3.2 +/- 0.6 Imol/h/100 g bw). The highest K+ excretion was revealed in experiments with glycerol administration (41 +/- 5 micromol/h vs. 7 +/- 2 micromol/h/100 g bw), Mg2+ --after exenatide injection (5.3 +/- 1.3 micromol/h vs. 0.16 +/- 0.03 micromol/ h/100 g bw). Diuretic effects were additive after combined administration of maximal doses of exenatide and PEG which suggests a different mechanism of action of solutes filtrated (PEG) to the proximal nephron segment and generated due to Na+/HW-exchange inhibition (exenatide). Osmotic diuretics differ by potency, mechanism of diuretic action and selectivity of ion excretion).

AUTOMATED DEAD-END ULTRAFILTRATION FOR ENHANCED SURVEILLANCE OF LEGIONELLA 2 PNEUMOPHILA AND LEGIONELLA SPP. IN COOLING TOWER WATERS

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

Brigmon, R.; Leskinen, S.; Kearns, E.

2011-10-10

Detection of Legionella pneumophila in cooling towers and domestic hot water systems involves concentration by centrifugation or membrane filtration prior to inoculation onto growth media or analysis using techniques such as PCR or immunoassays. The Portable Multi-use Automated Concentration System (PMACS) was designed for concentrating microorganisms from large volumes of water in the field and was assessed for enhancing surveillance of L. pneumophila at the Savannah River Site, SC. PMACS samples (100 L; n = 28) were collected from six towers between August 2010 and April 2011 with grab samples (500 ml; n = 56) being collected before and aftermore » each PMACS sample. All samples were analyzed for the presence of L. pneumophila by direct fluorescence immunoassay (DFA) using FITC-labeled monoclonal antibodies targeting serogroups 1, 2, 4 and 6. QPCR was utilized for detection of Legionella spp. in the same samples. Counts of L. pneumophila from DFA and of Legionella spp. from qPCR were normalized to cells/L tower water. Concentrations were similar between grab and PMACS samples collected throughout the study by DFA analysis (P = 0.4461; repeated measures ANOVA). The same trend was observed with qPCR. However, PMACS concentration proved advantageous over membrane filtration by providing larger volume, more representative samples of the cooling tower environment, which led to reduced variability among sampling events and increasing the probability of detection of low level targets. These data highlight the utility of the PMACS for enhanced surveillance of L. pneumophila by providing improved sampling of the cooling tower environment.« less

Radiofrequency ablation of renal cell carcinoma: a follow up of outcomes.

PubMed

Curry, David; Yassin, Musaab; Thwaini, Ali; Pahuja, Ajay; Alanbuki, Ammar H; Rajan, Thiagarajan Nambi; Loan, Willie

2014-02-01

To present the oncological outcomes in a series of patients with cT1a renal cell carcinoma (RCC) treated with radiofrequency ablation (RFA) and its effect on the glomerular filtration rate (GFR). Forty-five patients (48 renal units) treated at the Belfast City Hospital, over 4 years. Average age is 61.5 years (range 41-80). Eighteen patients (22 renal units) were included with American Society of Anesthesiologists (ASA) II and III. The rest were ASA I. Average tumor size was 2.63 cm (range 1.2 cm-6 cm). Renal function before and after RFA was recorded by means of the estimated glomerular filtration rate (eGFR) and the changes are presented. Oncological outcomes were established from follow up imaging. A satisfactory response was defined by disappearance or a persistence of non-enhancing lesion of smaller size at follow up. A partial response was defined by a persistent but non-enhancing similar size lesion. A failed response was defined by enlarging or persistently enhancing lesions. Mean follow up was 30.6 months (4-60 months). A good response was found in 33 (74%) patients. A partial response was found in 3 (8%) patients and failed response was identified in 8 (18%) patients. The average reduction in eGFR was 11 mL/min. Two patients had a 50% reduction in their eGFR. No patient required dialysis following treatment. RFA presents safe treatment choice for patients with RCC, particularly those that are high risk surgical candidates and those who refuse surgery. Short term results suggest good oncological outcomes and preservation of renal function.

A comparative study on the effects of barite, ilmenite and bentonite on four suspension feeding bivalves.

PubMed

Strachan, Maia F; Kingston, Paul F

2012-10-01

The impact of drilling mud components on the filtration activity and survival of bivalve molluscs was investigated by exposing them to suspensions of 'standard' barite, finely milled barite, ilmenite and bentonite in sea water. Introduction of the components stimulated filtration activity in all four bivalves. In addition, the introduction of standard barite and ilmenite both had lethal effects, with none of the bivalves surviving the full duration of the experiments. In-vivo observations of the gill surfaces provided direct evidence of physical damage caused by the administration of barite and ilmenite. A marked difference between filtration activity and survival of animals dosed with 'standard' barite and 'fine' barite suggests that the observed effects were primarily caused by physical interference with gill function. The results also suggest that the use of fine barite in offshore drilling may provide a more favourable environmental impact profile than the use of ilmenite. Copyright © 2012. Published by Elsevier Ltd.

The portable device for continual measurement of radon progenies on filter using the detector Timepix.

PubMed

Bulanek, Boris; Hulka, Jiri; Jilek, Karel; Stekl, Ivan

2015-06-01

In this article, a portable device was presented for continual measuring of equilibrium equivalent concentration (EEC) of (222)Rn based on the Timepix detector with 300-µm-thick active layer. In order to have a portable device, a filtration head was developed for collecting short-lived radon progenies attached on aerosols. The short-lived progenies are estimated from analysing alphas from decay of (218,214)Po from Millipore filter after termination of filtration. Comparison with beta measurement was done as well. The dependence of EEC on an air flow and filtration time was studied. The low-level detection limit for EEC was estimated from the last 10 min of 3-h decay measurement and was found in the range of 40-70 Bq m(-3). EEC was measured in National Radiation Protection Institute radon chamber, and results were compared with the commercial detector Fritra4. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Universal and reusable virus deactivation system for respiratory protection

NASA Astrophysics Data System (ADS)

Quan, Fu-Shi; Rubino, Ilaria; Lee, Su-Hwa; Koch, Brendan; Choi, Hyo-Jick

2017-01-01

Aerosolized pathogens are a leading cause of respiratory infection and transmission. Currently used protective measures pose potential risk of primary/secondary infection and transmission. Here, we report the development of a universal, reusable virus deactivation system by functionalization of the main fibrous filtration unit of surgical mask with sodium chloride salt. The salt coating on the fiber surface dissolves upon exposure to virus aerosols and recrystallizes during drying, destroying the pathogens. When tested with tightly sealed sides, salt-coated filters showed remarkably higher filtration efficiency than conventional mask filtration layer, and 100% survival rate was observed in mice infected with virus penetrated through salt-coated filters. Viruses captured on salt-coated filters exhibited rapid infectivity loss compared to gradual decrease on bare filters. Salt-coated filters proved highly effective in deactivating influenza viruses regardless of subtypes and following storage in harsh environmental conditions. Our results can be applied in obtaining a broad-spectrum, airborne pathogen prevention device in preparation for epidemic and pandemic of respiratory diseases.

Universal and reusable virus deactivation system for respiratory protection

PubMed Central

Quan, Fu-Shi; Rubino, Ilaria; Lee, Su-Hwa; Koch, Brendan; Choi, Hyo-Jick

2017-01-01

Aerosolized pathogens are a leading cause of respiratory infection and transmission. Currently used protective measures pose potential risk of primary/secondary infection and transmission. Here, we report the development of a universal, reusable virus deactivation system by functionalization of the main fibrous filtration unit of surgical mask with sodium chloride salt. The salt coating on the fiber surface dissolves upon exposure to virus aerosols and recrystallizes during drying, destroying the pathogens. When tested with tightly sealed sides, salt-coated filters showed remarkably higher filtration efficiency than conventional mask filtration layer, and 100% survival rate was observed in mice infected with virus penetrated through salt-coated filters. Viruses captured on salt-coated filters exhibited rapid infectivity loss compared to gradual decrease on bare filters. Salt-coated filters proved highly effective in deactivating influenza viruses regardless of subtypes and following storage in harsh environmental conditions. Our results can be applied in obtaining a broad-spectrum, airborne pathogen prevention device in preparation for epidemic and pandemic of respiratory diseases. PMID:28051158

Reuse of effluent water from a municipal wastewater treatment plant in microalgae cultivation for biofuel production.

PubMed

Cho, Sunja; Luong, Thanh Thao; Lee, Dukhaeng; Oh, You-Kwan; Lee, Taeho

2011-09-01

This study assessed the usability of effluent water discharged from a secondary municipal wastewater treatment plant for mass cultivation of microalgae for biofuel production. It was observed that bacteria and protozoa in the effluent water exerted a negative impact on the growth of Chlorella sp. 227. To reduce the effect, filtration or UV-radiation were applied on the effluent water as pre-treatment methods. Of all the pretreatment options tested, the filtration (by 0.2 μm) resulted in the highest biomass and lipid productivity. To be comparable with the growth in the autoclaved effluent water, the filtration with a proper pore size filter (less than 0.45 μm) or UV-B radiation of a proper dose (over 1620 mJ cm(-2)) are proposed. These findings led us to conclude that the utilization can be realized only when bacteria and other microorganisms are greatly reduced or eliminated from the effluent prior to its use. Copyright © 2011 Elsevier Ltd. All rights reserved.

Influence of linearly polarized near-infrared irradiation on deformability of human stored erythrocytes.

PubMed

Yokoyama, Kozo; Sugiyama, Kazuna

2003-02-01

To investigate the influence of linearly polarized near-infrared irradiation using the Super Lizer trade mark on deformability of human erythrocytes. Not only low-powered laser but also linearly polarized near-infrared beams have some biostimulation effects on various tissues. There were some reports of erythrocyte deformability improved by low-powered He-Ne laser irradiation. Human erythrocyte samples stored for three weeks were adjusted to 30% hematocrit. Erythrocyte deformability presented as the filter filtration rate was measured. There was no difference of the filter filtration rate between control group without irradiation and the group of 125 mJ/cm(2) exposure level at a wavelength of 830 nm. However, the groups of 625 and 1,250 mJ/cm(2) exposure levels at a wavelength of 830 nm showed higher filter filtration rates compared to the control group. Linearly polarized near-infrared irradiation in a range of 625-1,250 mJ/cm(2) exposure level at a wavelength of 830 nm improved deformability of human stored erythrocytes.

Fouling mechanisms of gel layer in a submerged membrane bioreactor.

PubMed

Hong, Huachang; Zhang, Meijia; He, Yiming; Chen, Jianrong; Lin, Hongjun

2014-08-01

The fouling mechanisms underlying gel layer formation and its filtration resistance in a submerged membrane bioreactor (MBR) were investigated. It was found that gel layer rather than cake layer was more easily formed when soluble microbial products content in sludge suspension was relatively high. Thermodynamic analyses showed that gel layer formation process should overcome a higher energy barrier as compared with cake layer formation process. However, when separation distance <2.3 nm, attractive interaction energy of gelling foulant-membrane combination was remarkably higher than that of sludge floc-membrane combination. The combined effects were responsible for gel layer formation. Filtration tests showed that specific filtration resistance (SFR) of gel layer was almost 100 times higher than that of cake layer. The unusually high SFR of gel layer could be ascribed to the gelling propensity and osmotic pressure mechanism. These findings shed significant light on fouling mechanisms of gel layer in MBRs. Copyright © 2014 Elsevier Ltd. All rights reserved.

Ischaemic Strokes in Patients with Pulmonary Arteriovenous Malformations and Hereditary Hemorrhagic Telangiectasia: Associations with Iron Deficiency and Platelets

PubMed Central

Shovlin, Claire L.; Chamali, Basel; Santhirapala, Vatshalan; Livesey, John A.; Angus, Gillian; Manning, Richard; Laffan, Michael A.; Meek, John; Tighe, Hannah C.; Jackson, James E.

2014-01-01

Background Pulmonary first pass filtration of particles marginally exceeding ∼7 µm (the size of a red blood cell) is used routinely in diagnostics, and allows cellular aggregates forming or entering the circulation in the preceding cardiac cycle to lodge safely in pulmonary capillaries/arterioles. Pulmonary arteriovenous malformations compromise capillary bed filtration, and are commonly associated with ischaemic stroke. Cohorts with CT-scan evident malformations associated with the highest contrast echocardiographic shunt grades are known to be at higher stroke risk. Our goal was to identify within this broad grouping, which patients were at higher risk of stroke. Methodology 497 consecutive patients with CT-proven pulmonary arteriovenous malformations due to hereditary haemorrhagic telangiectasia were studied. Relationships with radiologically-confirmed clinical ischaemic stroke were examined using logistic regression, receiver operating characteristic analyses, and platelet studies. Principal Findings Sixty-one individuals (12.3%) had acute, non-iatrogenic ischaemic clinical strokes at a median age of 52 (IQR 41–63) years. In crude and age-adjusted logistic regression, stroke risk was associated not with venous thromboemboli or conventional neurovascular risk factors, but with low serum iron (adjusted odds ratio 0.96 [95% confidence intervals 0.92, 1.00]), and more weakly with low oxygen saturations reflecting a larger right-to-left shunt (adjusted OR 0.96 [0.92, 1.01]). For the same pulmonary arteriovenous malformations, the stroke risk would approximately double with serum iron 6 µmol/L compared to mid-normal range (7–27 µmol/L). Platelet studies confirmed overlooked data that iron deficiency is associated with exuberant platelet aggregation to serotonin (5HT), correcting following iron treatment. By MANOVA, adjusting for participant and 5HT, iron or ferritin explained 14% of the variance in log-transformed aggregation-rate (p = 0.039/p = 0.021). Significance These data suggest that patients with compromised pulmonary capillary filtration due to pulmonary arteriovenous malformations are at increased risk of ischaemic stroke if they are iron deficient, and that mechanisms are likely to include enhanced aggregation of circulating platelets. PMID:24586400

Indoor air quality in 24 California residences designed as high-performance homes

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

Less, Brennan; Mullen, Nasim; Singer, Brett

2015-01-01

Today’s high performance green homes are reaching previously unheard of levels of airtightness and are using new materials, technologies and strategies, whose impacts on Indoor Air Quality (IAQ) cannot be fully anticipated from prior studies. This research study used pollutant measurements, home inspections, diagnostic testing and occupant surveys to assess IAQ in 24 new or deeply retrofitted homes designed to be high performance green buildings in California. Although the mechanically vented homes were six times as airtight as non-mechanically ventilated homes (medians of 1.1 and 6.1 ACH 50, n=11 and n=8, respectively), their use of mechanical ventilation systems and possiblymore » window operation meant their median air exchange rates were almost the same (0.30 versus 0.32 hr -1, n=8 and n=8, respectively). Pollutant levels were also similar in vented and unvented homes. In addition, these similarities were achieved despite numerous observed faults in complex mechanical ventilation systems. More rigorous commissioning is still recommended. Cooking exhaust systems were used inconsistently and several suffered from design flaws. Failure to follow best practices led to IAQ problems in some cases. Ambient nitrogen dioxide standards were exceeded or nearly so in four homes that either used gas ranges with standing pilots, or in Passive House-style homes that used gas cooking burners without venting range hoods. Homes without active particle filtration had particle count concentrations approximately double those in homes with enhanced filtration. The majority of homes reported using low-emitting materials; consistent with this, formaldehyde levels were approximately half those in conventional, new CA homes built before 2008. Emissions of ultrafine particles (with diameters <100 nm) were dramatically lower on induction electric cooktops, compared with either gas or resistance electric models. These results indicate that high performance homes can achieve acceptable and even exceptional IAQ by providing adequate general mechanical ventilation, using low-emitting materials, providing mechanical particle filtration, incorporating well-designed exhaust ventilation for kitchens and bathrooms, and educating occupants to use the kitchen and bath ventilation.« less

A Randomized Cross-over Air Filtration Intervention Trial for Reducing Cardiovascular Health Risks in Residents of Public Housing near a Highway

PubMed Central

Padró-Martínez, Luz T.; Owusu, Emmanuel; Reisner, Ellen; Zamore, Wig; Simon, Matthew C.; Mwamburi, Mkaya; Brown, Carrie A.; Chung, Mei; Brugge, Doug; Durant, John L.

2015-01-01

Exposure to traffic-generated ultrafine particles (UFP; particles <100 nm) is likely a risk factor for cardiovascular disease. We conducted a trial of high-efficiency particulate arrestance (HEPA) filtration in public housing near a highway. Twenty residents in 19 apartments living <200 m from the highway participated in a randomized, double-blind crossover trial. A HEPA filter unit and a particle counter (measuring particle number concentration (PNC), a proxy for UFP) were installed in living rooms. Participants were exposed to filtered air for 21 days and unfiltered air for 21 days. Blood samples were collected and blood pressure measured at days 0, 21 and 42 after a 12-hour fasting period. Plasma was analyzed for high sensitivity C-reactive protein (hsCRP), interleukin-6 (IL-6), tumor necrosis factor alpha-receptor II (TNF-RII) and fibrinogen. PNC reductions ranging from 21% to 68% were recorded in 15 of the apartments. We observed no significant differences in blood pressure or three of the four biomarkers (hsCRP, fibrinogen, and TNF-RII) measured in participants after 21-day exposure to HEPA-filtered air compared to measurements after 21-day exposure to sham-filtered air. In contrast, IL-6 concentrations were significantly higher following HEPA filtration (0.668 pg/mL; CI = 0.465–0.959) compared to sham filtration. Likewise, PNC adjusted for time activity were associated with increasing IL-6 in 14- and 21-day moving averages, and PNC was associated with decreasing blood pressure in Lags 0, 1 and 2, and in a 3-day moving average. These negative associations were unexpected and could be due to a combination of factors including exposure misclassification, unsuccessful randomization (i.e., IL-6 and use of anti-inflammatory medicines), or uncontrolled confounding. Studies with greater reduction in UFP levels and larger sample sizes are needed. There also needs to be more complete assessment of resident time activity and of outdoor vs. indoor source contributions to UFP exposure. HEPA filtration remains a promising, but not fully realized intervention. PMID:26184257

TU-EF-204-08: Dose Efficiency of Added Beam-Shaping Filter with Varied Attenuation Levels in Lung-Cancer Screening CT

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

Ma, C; Yu, L; Vrieze, T

Purpose: Added filtration such as tin filter has the potential to improve dose efficiency of x-ray beam in lung-cancer screening CT. However, dose efficiency with added beam filtration is highly dependent on patient attenuation level. In this phantom study, we evaluated the image quality at different tube voltages with and without added tin filter when attenuation level varies. Methods: A 30 x 20 cm anthropomorphic thorax phantom with three added extension rings were used to simulate small (S), medium (M), large (L), and extra-large (XL) adult patients. These phantoms were scanned on a 192-slice CT scanner (Force, Siemens) at 100more » and 120kV without tin filtration, and 100 and 150 kV with tin filtration (100Sn and 150Sn), at multiple dose levels at each kV. Images were reconstructed using iterative reconstruction (ADMIRE, Siemens). Radiation dose was measured with a 0.6 cc ion chamber in the middle and peripheral areas of the phantom. Image quality was assessed using mean image noise at uniform areas in the central region and lung. Radiation dose that is required for each kV to match the noise in a routine lung-cancer CT screening technique (120kV, 25 quality reference mAs) was calculated. Results: At each of the four phantom sizes, 100Sn had the lowest noise in both soft tissue and lung. Compared with 120 kV, 100Sn saved 39%–60% dose for the same noise, depending on phantom size. For the XL phantom (50 by 40 cm), 150Sn provided images with the least beam-hardening artifact in peripheral region. Conclusion: For thoracic CT, added tin filtration can provide considerable dose reduction compared with 120 kV. 100Sn provides better dose efficiencies for all phantom sizes, while 150Sn provides better image quality in peripheral region for extra-large patients. Drs.Joel G. Fletcher and Cynthia H. McCollough receive research support from Siemens Healthcare.« less

A Randomized Cross-over Air Filtration Intervention Trial for Reducing Cardiovascular Health Risks in Residents of Public Housing near a Highway.

PubMed

Padró-Martínez, Luz T; Owusu, Emmanuel; Reisner, Ellen; Zamore, Wig; Simon, Matthew C; Mwamburi, Mkaya; Brown, Carrie A; Chung, Mei; Brugge, Doug; Durant, John L

2015-07-10

Exposure to traffic-generated ultrafine particles (UFP; particles <100 nm) is likely a risk factor for cardiovascular disease. We conducted a trial of high-efficiency particulate arrestance (HEPA) filtration in public housing near a highway. Twenty residents in 19 apartments living <200 m from the highway participated in a randomized, double-blind crossover trial. A HEPA filter unit and a particle counter (measuring particle number concentration (PNC), a proxy for UFP) were installed in living rooms. Participants were exposed to filtered air for 21 days and unfiltered air for 21 days. Blood samples were collected and blood pressure measured at days 0, 21 and 42 after a 12-hour fasting period. Plasma was analyzed for high sensitivity C-reactive protein (hsCRP), interleukin-6 (IL-6), tumor necrosis factor alpha-receptor II (TNF-RII) and fibrinogen. PNC reductions ranging from 21% to 68% were recorded in 15 of the apartments. We observed no significant differences in blood pressure or three of the four biomarkers (hsCRP, fibrinogen, and TNF-RII) measured in participants after 21-day exposure to HEPA-filtered air compared to measurements after 21-day exposure to sham-filtered air. In contrast, IL-6 concentrations were significantly higher following HEPA filtration (0.668 pg/mL; CI = 0.465-0.959) compared to sham filtration. Likewise, PNC adjusted for time activity were associated with increasing IL-6 in 14- and 21-day moving averages, and PNC was associated with decreasing blood pressure in Lags 0, 1 and 2, and in a 3-day moving average. These negative associations were unexpected and could be due to a combination of factors including exposure misclassification, unsuccessful randomization (i.e., IL-6 and use of anti-inflammatory medicines), or uncontrolled confounding. Studies with greater reduction in UFP levels and larger sample sizes are needed. There also needs to be more complete assessment of resident time activity and of outdoor vs. indoor source contributions to UFP exposure. HEPA filtration remains a promising, but not fully realized intervention.

Optimisation of radiation dose and image quality in mobile neonatal chest radiography.

PubMed

Hinojos-Armendáriz, V I; Mejía-Rosales, S J; Franco-Cabrera, M C

2018-05-01

To optimise the radiation dose and image quality for chest radiography in the neonatal intensive care unit (NICU) by increasing the mean beam energy. Two techniques for the acquisition of NICU AP chest X-ray images were compared for image quality and radiation dose. 73 images were acquired using a standard technique (56 kV, 3.2 mAs and no additional filtration) and 90 images with a new technique (62 kV, 2 mAs and 2 mm Al filtration). The entrance surface air kerma (ESAK) was measured using a phantom and compared between the techniques and against established diagnostic reference levels (DRL). Images were evaluated using seven image quality criteria independently by three radiologists. Images quality and radiation dose were compared statistically between the standard and new techniques. The maximum ESAK for the new technique was 40.20 μGy, 43.7% of the ESAK of the standard technique. Statistical evaluation demonstrated no significant differences in image quality between the two acquisition techniques. Based on the techniques and acquisition factors investigated within this study, it is possible to lower the radiation dose without any significant effects on image quality by adding filtration (2 mm Al) and increasing the tube potential. Such steps are relatively simple to undertake and as such, other departments should consider testing and implementing this dose reduction strategy within clinical practice where appropriate. Copyright © 2017 The College of Radiographers. Published by Elsevier Ltd. All rights reserved.

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

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

Optimal Design of Dialyzers.

PubMed

Mineshima, Michio

2017-01-01

Several types of synthetic dialysis membranes, including polysulfone, polyethersulfone, and polyester polymer alloy membranes, have asymmetrical structures. Dialyzers with these membranes show higher water and solute transport performance because the actual membrane thickness, which is related to the water and solute transfer resistance, is quite small compared with that in membranes with a homogeneous structure. The performance of a dialyzer depends not only on membrane permeability to water and solutes, but also on flow conditions of the blood and dialysate, which are determined during dialyzer fabrication. Many types of high-flux dialyzers with high-performance membranes have a high internal filtration/backfiltration (IF/BF) flow rate. In the enhanced IF/BF dialyzer, membrane fouling occurs more readily than with the conventional dialyzer because of the high local transmembrane pressure needed to enhance the IF/BF flow rate. To select the optimal enhanced IF/BF dialyzer for individual patients, we need to balance the disadvantage of membrane fouling with the advantage of increased convective transport. Key Messages: The following principles should guide dialyzer development in the near term. (1) Dialyzers should show high performance for the removal of low-molecular-weight proteins related to certain complications under conditions of low albumin and amino acid loss. (2) Dialyzers with biocompatible membranes are required to prevent severe adverse reactions, even though the causal relationship between these reactions and some complications remains to be clarified. © 2017 S. Karger AG, Basel.