Science.gov

Sample records for filtration centrifugation deliquoring

  1. Mechanisms of flow through compressible porous beds in sedimentation, filtration, centrifugation, deliquoring, and ceramic processing

    SciTech Connect

    Tiller, F.M.

    1992-06-01

    The University of Houston research program is aimed at the specific area of solid/liquid separation including sedimentation, thickening, cake filtration, centrifugation, expression, washing, deep-bed filtration, screening, and membrane separation. Unification of the theoretical approaches to the various solid/liquid separation operations is the principle objective of the research. Exploring new aspects of basic separation mechanisms, verification of theory with experiment, development of laboratory procedures for obtaining data for design, optimizing operational methods, and transferring the results to industry are a part of the Houston program. New methodology developed in our program now permits an engineer or scientist to handle thickening, cake filtration, centrigual filtration, and expression in a unified manner. The same fundamental equations are simply adapted to the differing parameters and conditions related to the various modes of separation. As the system is flexible and adaptable to computational software, new developments can continually be added. Discussions of the various research projects in this report have been kept to a minimum and are principally qualitative. The length of the report would be excessive if each topic were covered in depth. Although the number of research topics may appear larger than one would expect, many are closely interconnected and reflect our philosophy of working in apparently diverse fields such as ceramics, mining, wastewater, food, chemical processing, and oil well operations.

  2. Mechanisms of flow through compressible porous beds in sedimentation, filtration, centrifugation, deliquoring, and ceramic processing. Progress report, January 1993--November 1993

    SciTech Connect

    Tiller, F.M.

    1993-11-01

    The research program is involved with the area of solid/liquid separation including sedimentation, thickening, cake filtration, centrifugation, expression, washing, deep-bed filtration, screening, and membrane separation. Objective is the unification of theoretical approaches to solid/liquid separations. The research is divided according to: Centrifugation, cake filtration, sedimentation/thickening, and optimization studies (tubular arrangements in candle filters; maximizing filtration rates with filter aids).

  3. Mechanisms of flow through compressible porous beds in sedimentation, filtration, centrifugation, deliquoring, and ceramic processing. [Annual report], February 1, 1991--January 31, 1992

    SciTech Connect

    Tiller, F.M.

    1992-06-01

    The University of Houston research program is aimed at the specific area of solid/liquid separation including sedimentation, thickening, cake filtration, centrifugation, expression, washing, deep-bed filtration, screening, and membrane separation. Unification of the theoretical approaches to the various solid/liquid separation operations is the principle objective of the research. Exploring new aspects of basic separation mechanisms, verification of theory with experiment, development of laboratory procedures for obtaining data for design, optimizing operational methods, and transferring the results to industry are a part of the Houston program. New methodology developed in our program now permits an engineer or scientist to handle thickening, cake filtration, centrigual filtration, and expression in a unified manner. The same fundamental equations are simply adapted to the differing parameters and conditions related to the various modes of separation. As the system is flexible and adaptable to computational software, new developments can continually be added. Discussions of the various research projects in this report have been kept to a minimum and are principally qualitative. The length of the report would be excessive if each topic were covered in depth. Although the number of research topics may appear larger than one would expect, many are closely interconnected and reflect our philosophy of working in apparently diverse fields such as ceramics, mining, wastewater, food, chemical processing, and oil well operations.

  4. Mechanisms of flow through compressible porous beds in sedimentation, centrifugation, deliquoring, and ceramic processing

    SciTech Connect

    1996-01-25

    The major topics covered in the investigation include: centrifugation; cake filtration; sedimentation and thickening; capillary suction operations; ceramics, slip casting; optimization studies; and wastewater. The research program was aimed at the specific areas of solid/liquid separation including sedimentation, thickening, cake filtration, centrifugation, expression, washing, deep-bed filtration, screening, and membrane separation. Unification of the theoretical approaches to the various solid/liquid separation operations was the principle objective of the research. Exploring new aspects of basic separation mechanisms, verification of theory with experiment, development of laboratory procedures for obtaining data for design, optimizing operational methods, and transferring the results to industry were part of the program.

  5. CENTRIFUGAL MEMBRANE FILTRATION

    SciTech Connect

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

    1999-10-01

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

  6. CENTRIFUGAL MEMBRANE FILTRATION

    SciTech Connect

    William A. Greene; Patricia A. Kirk; Richard Hayes; Joshua Riley

    2005-10-28

    SpinTek Membrane Systems, Inc., the developer of a centrifugal membrane filtration technology, has engineered and developed a system for use within the U.S. Department of Energy (DOE) Environmental Management (EM) Program. The technology uses supported microporous membranes rotating at high rpm, under pressure, to separate suspended and colloidal solids from liquid streams, yielding a solids-free permeate stream and a highly concentrated solids stream. This is a crosscutting technology that falls under the Efficient Separations and Processing Crosscutting Program, with potential application to tank wastes, contaminated groundwater, landfill leachate, and secondary liquid waste streams from other remediation processes, including decontamination and decommissioning systems. SpinTek II High Shear Rotary Membrane Filtration System is a unique compact crossflow membrane system that has large, demonstrable advantages in performance and cost compared to currently available systems: (1) High fluid shear prevents membrane fouling even with very high solids content; hazardous and radioactive components can be concentrated to the consistency of a pasty slurry without fouling. (2) Induced turbulence and shear across the membrane increases membrane flux by a factor of ten over existing systems and allows operation on fluids not otherwise treatable. (3) Innovative ceramic membrane and mechanical sealing technology eliminates compatibility problems with aggressive DOE waste streams. (4) System design allows rapid, simple disassembly for inspection or complete decontamination. (5) Produces colloidal- and suspended-solids-free filtrate without the addition of chemicals. The first phase of this project (PRDA maturity stage 5) completed the physical scale-up of the SpinTek unit and verified successful scale-up with surrogate materials. Given successful scale-up and DOE concurrence, the second phase of this project (PRDA maturity stage 6) will provide for the installation and

  7. Centrifugal membrane filtration -- Task 9

    SciTech Connect

    1996-08-01

    The Energy and Environmental Research Center (EERC) has teamed with SpinTek Membrane Systems, Inc., the developer of a centrifugal membrane filtration technology, to demonstrate applications for the SpinTek technology within the US Department of Energy (DOE) Environmental management (EM) Program. The technology uses supported microporous membranes rotating at high rpm, under pressure, to separate suspended and colloidal solids from liquid streams, yielding a solids-free permeate stream and a highly concentrated solids stream. This is a crosscutting technology that falls under the Efficient Separations and Processing Crosscutting Program, with potential application to tank wastes, contaminated groundwater, landfill leachate, and secondary liquid waste streams from other remediation processes, including decontamination and decommissioning systems. Membrane-screening tests were performed with the SpinTek STC-X4 static test cell filtration unit, using five ceramic membranes with different pore size and composition. Based on permeate flux, a 0.25-{micro}m TiO{sub 2}/Al{sub 2}O{sub 3} membrane was selected for detailed performance evaluation using the SpinTek ST-IIL centrifugal membrane filtration unit with a surrogate tank waste solution. An extended test run of 100 hr performed on a surrogate tank waste solution showed some deterioration in filtration performance, based on flux, apparently due to the buildup of solids near the inner portion of the membrane where relative membrane velocities were low. Continued testing of the system will focus on modifications to the shear pattern across the entire membrane surface to affect improved long-term performance.

  8. Assessment and mitigation of DNA loss utilizing centrifugal filtration devices.

    PubMed

    Doran, Ashley E; Foran, David R

    2014-11-01

    Maximizing DNA recovery during its isolation can be vital in forensic casework, particularly when DNA yields are expected to be low, such as from touch samples. Many forensic laboratories utilize centrifugal filtration devices to purify and concentrate the DNA; however, DNA loss has been reported when using them. In this study, all centrifugal filtration devices tested caused substantial DNA loss, affecting low molecular weight DNA (PCR product) somewhat more than high molecular weight DNA. Strategies for mitigating DNA loss were then examined, including pre-treatment with glucose, glycogen, silicone (RainX(®)), bovine serum albumin, yeast RNA, or high molecular weight DNA. The length of pre-treatment and UV irradiation of pre-treatment reagents were also investigated. Pre-treatments with glucose and glycogen resulted in little or no improvement in DNA recovery, and most or all DNA was lost after silicone pre-treatment. Devices pre-treated with BSA produced irregular and uninterpretable quantitative PCR amplification curves for the DNA and internal PCR control. On the other hand, nucleic acid pre-treatments greatly improved recovery of all DNAs. Pre-treatment time and its UV irradiation did not influence DNA recovery. Overall, the results show that centrifugal filtration devices trap DNA, yet their proper pre-treatment can circumvent that loss, which is critical in the case of low copy forensic DNA samples.

  9. Effect of particle size on the performance of batchwise centrifugal filtration.

    PubMed

    Hwang, K J

    2001-01-01

    The effect of particle size distribution on the performance of batchwise centrifugal filtration is studied. By analyzing the velocity of particles in a filter, a numerical program is designed for simulating the migration and deposition of particles. The particle size distributions and the average specific filtration resistances of cake are then estimated under various rotating speeds of the centrifuge. A large deviation of particle concentration profiles in the filter chamber will occur if the particle size distribution is not taken into consideration. A more heterogeneous cake will form under a lower rotating speed due to the sedimentation effect of particles. The predicted results of particle size distribution and average specific filtration resistance of cake agree well with the available experimental data.

  10. Enabling safe dry cake disposal of bauxite residue by deliquoring and washing with a membrane filter press.

    PubMed

    Kinnarinen, Teemu; Lubieniecki, Boguslaw; Holliday, Lloyd; Helsto, Jaakko-Juhani; Häkkinen, Antti

    2015-03-01

    Dry cake disposal is the preferred technique for the disposal of bauxite residue, when considering environmental issues together with possible future utilisation of the solids. In order to perform dry cake disposal in an economical way, the deliquoring of the residue must be carried out efficiently, and it is also important to wash the obtained solids well to minimise the amount of soluble soda within the solids. The study presented in this article aims at detecting the most important variables influencing the deliquoring and washing of bauxite residue, performed with a horizontal membrane filter press and by determining the optimal washing conditions. The results obtained from pilot-scale experiments are evaluated by considering the properties of the solids, for instance, the residual alkali and aluminium content, as well as the consumption of wash liquid. Two different cake washing techniques, namely classic washing and channel washing, are also used and their performances compared. The results show that cake washing can be performed successfully in a horizontal membrane filter press, and significant improvements in the recovery of alkali and aluminium can be achieved compared with pressure filtration carried out without washing, or especially compared with the more traditionally used vacuum filtration.

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

    NASA Technical Reports Server (NTRS)

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

    1981-01-01

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

  12. Effects of ultra-clean and centrifugal filtration on rolling-element bearing life

    NASA Technical Reports Server (NTRS)

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

    1981-01-01

    Fatigue tests were conducted on groups of 65-mm bore diameter deep-groove ball bearings in a MIL-L-23699 lubricant under two levels of filtration to determine the upper limit in bearing life under the strictest possible lubricant cleanliness conditions. Bearing fatigue lives, surface distress and weight loss were compared to previous bearing fatigue tests in contaminated and noncontaminated oil filters having absolute removal ratings of 3, 30, 49, and 105 microns, with lubricant and sump temperatures maintained at 347 K. Ultra clean lubrication was found to produce bearing fatigue lives that were approximately twice that obtained in previous tests with contaminated oil using 3 micron absolute filtration. It was also observed that the centrifugal oil filter has the same effectiveness as a 30 micron absolute filter in preventing surface damage.

  13. Task 9 - centrifugal membrane filtration. Semi-annual report April 1--September 30, 1996

    SciTech Connect

    Stepan, D.J.; Moe, T.A.; Collings, M.E.

    1997-05-01

    This report assesses a centrifugal membrane filtration technology developed by SpinTek Membrane Systems, Inc. The technology uses supported microporous membranes rotating at high rpm, under pressure, to separate suspended and colloidal solids from liquid streams, yielding a solids-free permeate stream and a highly concentrated solids stream. The Tank Waste Focus Area was chosen for study. Membrane-screening tests were performed with the STC-X4 static test cell filtration unit, using five ceramic membranes with different pore size and composition. Based on permeate flux, a 0.25-{mu}m TiO{sub 2}/Al{sub 2}O{sub 3} membrane was selected for detailed performance evaluation using the centrifugal membrane filtration unit with a surrogate tank waste solution. The performance of the unit was evaluated with a statistical test design that determined the effect of temperature, pressure, membrane rotational speed, and solids loading on permeate flux. All four variables were found to be statistically significant, with the magnitude of the effect in the order of temperature, solids loading, rotor speed, and pressure. Temperature, rotor speed, and pressure had an increasing effect on flux with increasing value, while increases in solids loading showed a decrease in permeate flux. Significant interactions between rotor speed and solids loading and pressure and solids loading were also observed. The regression equation derived from test data had a correlation coefficient of 0.934, which represents a useful predictive capability for integrating the technology into DOE cleanup efforts. An extended test run performed on surrogate waste showed some deterioration in filtration performance, based on flux, apparently due to the buildup of solids near the inner portion of the membrane where relative membrane velocities were low. Continued testing of the system will focus on modifications to the shear pattern across the entire membrane surface to affect improved long-term performance.

  14. Comparison of the compressive yield response of aggregated suspensions: Pressure filtration, centrifugation, and osmotic consolidation

    SciTech Connect

    Miller, K.T.; Melant, R.M.; Zukoski, C.F.

    1996-10-01

    The compressive rheological responses of suspensions containing flocculated kaolin, alumina (average particle sizes of 0.2 and 0.5 {micro}m), and hydrous zirconia (average particle sizes of 8, 57, and 139 nm) particles have been measured using three different techniques: pressure filtration, volume fraction profile during centrifugation, and sediment height during centrifugation at multiple spinning speeds. While the volume fraction profile technique appears to be experimentally most robust, equivalent responses are found using the different techniques, indicating that the compressive yield stress is a material property of a given suspension. The compressive yield stress of each suspension increases rapidly with volume fraction but cannot be generally described using simple power-law or exponential fits. The compressive yield stress also increases with the inverse square of particle size. The packing behavior of the suspensions undergoing osmotic consolidation is compared with the mechanical compressive yield response. Some suspensions exhibited the same packing behavior as in the mechanical techniques, while others consistently packed to higher densities during osmotic consolidation. Although equivalent osmotic and mechanical loads do not always result in the same volume fractions, the similar increases in volume fraction with applied driving force suggest that both the osmotic and mechanical techniques are controlled by the force needed to rearrange the particle network.

  15. Concentration of Sonication Fluid through Centrifugation Is Superior to Membrane Filtration for Microbial Diagnosis of Orthopedic Implant-Associated Infection.

    PubMed

    Zitron, Renato; Wajsfeld, Tali; Klautau, Giselle Burlamaqui; da Silva, Cely Barreto; Nigro, Stanley; Mercadante, Marcelo Tomanik; Polesello, Giancarlo Cavalli; Cury, Ricardo de Paula Leite; Salles, Mauro Jose Costa

    2016-03-01

    Microbial identification of orthopedic implant-associated infections using sonication fluid (SF) submitted to a concentration step by membrane filtration (SMF) was compared with the standard centrifugation (SC) method. Among 33 retrieved infected implants, sonication identified microorganisms in 26 (78.8%). The sensitivity of SC was higher than that of SMF (78.8% versus 30.3%; P < 0.001).

  16. Comparison [(3)H]-flumazenil binding parameters in rat cortical membrane using different separation methods, filtration and centrifugation.

    PubMed

    Ahmadi, Fatemeh; Faizi, Mehrdad; Tabatabai, Sayyed Abbas; Beiki, Davood; Shahhosseini, Soraya

    2013-10-01

    Radioligand receptor binding assays are a common method to evaluate the affinity of newly synthesized benzodiazepine ligands for the receptor. [(3)H]-flumazenil is an antagonist of benzodiazepine receptors and is generally used as a radioligand. In this study, the binding parameters of [(3)H]-flumazenil to rat cortical membranes were evaluated using two separation methods: filtration with GF/C filters and centrifugation. Additionally, the effects of vacuum pressure, exposure time to the cocktail, and geometry on the filtration method were studied. The binding parameters of [(3)H]-flumazenil (Kd and Bmax) were determined through saturation studies using two methods. The results from this study showed that the filtration method is time consuming and requires more steps to be completed. Because filtration causes partial elution of bound [(3)H]-flumazenil into the liquid scintillation cocktail, the results are not reproducible, which result in inaccurate estimation of the binding parameters. The centrifugation method in contrast to filtration is straightforward and produces reproducible as well as reliable results, all of the steps are performed in a single polypropylene tube, which eliminates the loss of tissue and avoids other systematic errors associated with transfer and handling.

  17. [Comparison of the Conventional Centrifuged and Filtrated Preparations in Urine Cytology].

    PubMed

    Sekita, Nobuyuki; Shimosakai, Hirofumi; Nishikawa, Rika; Sato, Hiroaki; Kouno, Hiroyoshi; Fujimura, Masaaki; Mikami, Kazuo

    2016-03-01

    The urine cytology test is one of the most important tools for the diagnosis of malignant urinary tract tumors. This test is also of great value for predicting malignancy. However, the sensitivity of this test is not high enough to screen for malignant cells. In our laboratory, we were able to attain a high sensitivity of urine cytology tests after changing the preparation method of urine samples. The differences in the cytodiagnosis between the two methods are discussed here. From January 2012 to June 2013, 2,031 urine samples were prepared using the conventional centrifuge method (C method) ; and from September 2013 to March 2015, 2,453 urine samples were prepared using the filtration method (F method) for the cytology test. When the samples included in category 4 or 5, were defined as cytological positive, the sensitivities of this test with samples prepared using the F method were significantly high compared with samples prepared using the C method (72% vs 28%, p<0.001). The number of cells on the glass slides prepared by the F method was significantly higher than that of the samples prepared by the C method (p<0.001). After introduction of the F method, the number of f alse negative cases was decreased in the urine cytology test because a larger number of cells was seen and easily detected as atypical or malignant epithelial cells. Therefore, this method has a higher sensitivity than the conventional C method as the sensitivity of urine cytology tests relies partially on the number of cells visualized in the prepared samples.

  18. CENTRIFUGE

    DOEpatents

    Rushing, F.C.

    1960-09-01

    A vibration damping mechanism for damping vibration forces occurring during the operation of a centrifuge is described. The vibration damping mechanism comprises a plurality of nested spaced cylindrical elements surrounding the rotating shaft of the centrifuge. Some of the elements are held substantially stationary while the others are held with respect to a pair of hearings spaced along the rotating shaft. A fluid is retained about the cylindrical elements.

  19. The effect of cyanobacterial biomass enrichment by centrifugation and GF/C filtration on subsequent microcystin measurement.

    PubMed

    Rogers, Shelley; Puddick, Jonathan; Wood, Susanna A; Dietrich, Daniel R; Hamilton, David P; Prinsep, Michele R

    2015-03-10

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

  20. MALDI-TOF identification of Gram-negative bacteria directly from blood culture bottles containing charcoal: Sepsityper® kits versus centrifugation-filtration method.

    PubMed

    Riederer, Kathleen; Cruz, Kristian; Shemes, Stephen; Szpunar, Susan; Fishbain, Joel T

    2015-06-01

    Matrix-assisted laser desorption ionization time-of-flight (MALDI-TOF) mass spectrometry has dramatically altered the way microbiology laboratories identify clinical isolates. Direct blood culture (BC) detection may be hampered, however, by the presence of charcoal in BC bottles currently in clinical use. This study evaluates an in-house process for extraction and MALDI-TOF identification of Gram-negative bacteria directly from BC bottles containing charcoal. Three hundred BC aliquots were extracted by a centrifugation-filtration method developed in our research laboratory with the first 96 samples processed in parallel using Sepsityper® kits. Controls were colonies from solid media with standard phenotypic and MALDI-TOF identification. The identification of Gram-negative bacteria was successful more often via the in-house method compared to Sepsityper® kits (94.7% versus 78.1%, P≤0.0001). Our in-house centrifugation-filtration method was further validated for isolation and identification of Gram-negative bacteria (95%; n=300) directly from BC bottles containing charcoal.

  1. Severe Hemolysis in a Patient With Erythrocytosis During Coupled Plasma Filtration Adsorption Therapy Was Prevented by Changing From Membrane-Based Technique to a Centrifuge-Based One.

    PubMed

    Fan, Rong; Wu, Buyun; Kong, Ling; Gong, Dehua

    2016-01-01

    Coupled plasma filtration adsorption (CPFA) usually adopts membrane to separate plasma from blood. Here, we reported a case with erythrocytosis experienced severe hemolysis and membrane rupture during CPFA, which was avoided by changing from membrane-based technique to a centrifuge-based one. A 66-year-old man was to receive CPFA for severe hyperbilirubinemia (total bilirubin 922 μmol/L, direct bilirubin 638 μmol/L) caused by obstruction of biliary tract. He had erythrocytosis (hemoglobin 230 g/L, hematocrit 0.634) for years because of untreated tetralogy of Fallot. Severe hemolysis and membrane rupture occurred immediately after blood entering into the plasma separator even at a low flow rate (50 mL/min) and persisted after changing a new separator. Finally, centrifugal plasma separation technique was used for CPFA in this patient, and no hemolysis occurred. After 3 sessions of CPFA, total bilirubin level decreased to 199 μmol/L with an average decline by 35% per session. Thereafter, the patient received endoscopic biliary stent implantation, and total bilirubin level returned to nearly normal. Therefore, centrifugal-based plasma separation can also be used in CPFA and may be superior to a membrane-based one in patients with hyperviscosity.

  2. Asparaginase-associated concurrence of hyperlipidemia, hyperglobulinemia, and thrombocytosis was successfully treated by centrifuge/membrane hybrid double-filtration plasmapheresis.

    PubMed

    Wang, Taina; Xu, Bin; Fan, Rong; Liu, Zhihong; Gong, Dehua

    2016-01-01

    Asparaginase-associated concurrence of hyperlipidemia, hyperglobulinemia, and thrombocytosis is a rare complication requiring aggressive lipoprotein apheresis, but no one of currently available lipoprotein apheresis methods can simultaneously resolve the 3 abnormalities. Herein, we reported a construction of double-filtration plasmapheresis (DFPP) using a combination of centrifugal/membranous plasma separation techniques to successfully treat a patient with hyperlipidemia, hyperglobulinemia, and thrombocytosis. A male presented with severe hyperlipidemia, hyperglobulinemia, and thrombocytosis during asparaginase treatment for NK/T-cell lymphoblastic lymphoma and was scheduled to receive lipoprotein apheresis. To simultaneously remove lipoproteins, immunoglobulin, and deplete platelets from blood, a centrifuge/membrane hybrid DFPP was constructed as following steps: plasma and part of platelets were separated first from whole blood by centrifugal technique and then divided by a fraction plasma separator into 2 parts: platelets and plasma components with large size, which were discarded; and those containing albumin, which were returned to blood with a supplement of extrinsic albumin solution. DFPP lasted 240 minutes uneventfully, processing 5450-mL plasma. The concentrations of plasma components before DFPP were as follows: triglycerides 38.22 mmol/L, total cholesterols 22.98 mmol/L, immunoglobulin A (IgA) 15.7 g/L, IgG 12.7 g/L, and IgM 14.3 g/L; whereas after treatment were 5.69 mmol/L, 2.38 mmol/L, 2.5 g/L, 7.7 g/L, and 0.4 g/L, respectively. The respective reduction ratio was 85.1%, 89.6%, 83.9%, 39.4%, and 96.9%. Platelet count decreased by 40.4% (from 612 × 10(9)/L to 365 × 10(9)/L). Centrifuge/membrane hybrid DFPP can simultaneously remove lipoproteins, immunoglobulin, and deplete platelets, with a success in treatment of asparaginase treatment-induced hyperlipidemia, hyperglobulinemia, and thrombocytosis, and may be useful for patients

  3. Use of Carbon Nanotubes as a Solid Support To Establish Quantitative (Centrifugation) and Qualitative (Filtration) Immunoassays To Detect Gentamicin Contamination in Commercial Milk.

    PubMed

    Zeng, Kun; Wei, Wei; Jiang, Ling; Zhu, Fang; Du, Daolin

    2016-10-11

    Current methods to detect gentamicin (GEN), a broad-spectrum antibiotic that causes ototoxicity and nephrotoxicity when present in excess, have several limitations. Hence, we have developed two methods using multi-walled carbon nanotubes (MWCNTs) as a solid support to detect GEN. Hybridoma cells (2D12) producing high-sensitivity antibodies against GEN were established. The goat anti-mouse antibody was immobilized on MWCNTs directly or using bifunctional polyethylene glycol as a linker. On the basis of the physical characteristics of MWCNTs, a quantitative method involving centrifugation separation and a qualitative method involving filtration separation were established. Various experimental parameters were optimized for GEN detection, and recovery tests were performed. For the quantitative method, the limit of detection (LOD) was 0.048 ng/mL, whereas for the qualitative method, a LOD of 0.1 ng/mL was observed by the naked eye. The proposed immunoassays were applied to commercial milk samples. Thus, these methods show potential application for the detection of GEN.

  4. Evaluation of two new filtration systems--Fenwal PS400 and Organon Teknika Curesis--and comparison of results with two centrifugation systems--IBM model 2997 and Haemonetics V50.

    PubMed

    Coffe, C; Couteret, Y; Pujol, J P; Kieffer, Y; Lenys, R; Panouse, J; Peters, A

    1985-07-01

    Two new filtration systems (Fenwal CPS 10TM - PS 400 and Organon Teknika Curesis - M82) were evaluated and compared with two centrifugal cell separators (IBM 2997 and Haemonetics V50). 11 patients with auto immune diseases and dermatological diseases underwent 230 consecutive plasma exchanges. For the filtration systems, the average whole blood rate was 50 ml/min and the plasma separation rate was about 21 ml/min for a transmembrane pressure about 70 mmHg. The pre/post percent reduction and sieving coefficient were calculated for some plasma and blood components. A variety of laboratory studies was monitored to assess the efficacy of plasma separators, their biocompatibility and some yields. These results show that the 2 filters appear safe and efficacious but their modules are too simple and do not offer a great security (no transmembrane pressure control or no extracorporeal fluid balance). For a blood banker, IBM 2997 seems more interesting if we take in account its characteristics during plasma exchanges and the possibility which is offered to carry out cytapheresis procedures. But for a thrombopenic patient the filtration systems keep their advantages.

  5. CENTRIFUGE APPARATUS

    DOEpatents

    Skarstrom, C.; Urey, H.C.; Cohen, K.

    1960-08-01

    A high-speed centrifuge for the separation of gaseous isotopes is designed comprising a centrifugal pump mounted on the outlet of a centrifuge bowl and arranged to pump the heavy and light fractions out of the centrifuge bowl in two separate streams.

  6. Filtration Fundamentals.

    ERIC Educational Resources Information Center

    Ward, Ken; Hunsaker, Scot

    1997-01-01

    Examines how choice of commercial swimming-pool filtration systems is driven by the project-specific needs of the pools. Also highlighted are definitions of specific terms used when discussing filtration systems. Questions that pool designers can answer to make filtration-system purchasing decisions are listed. (GR)

  7. 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.

  8. Centrifuge apparatus

    DOEpatents

    Sartory, Walter K.; Eveleigh, John W.

    1976-01-01

    A method and apparatus for operating a continuous flow blood separation centrifuge are provided. The hematocrit of the entrant whole blood is continuously maintained at an optimum constant value by the addition of plasma to the entrant blood. The hematocrit of the separated red cells is monitored to indicate the degree of separation taking place, thereby providing a basis for regulating the flow through the centrifuge.

  9. Centrifugal pyrocontactor

    DOEpatents

    Chow, L.S.; Leonard, R.A.

    1993-10-19

    A method is described for mixing and separating immiscible liquid salts and liquid metals in a centrifugal contractor. The method includes introducing the liquids into an annular mixing zone and intensely mixing the liquids using vertical vanes attached to a rotor cooperating with vertical baffles, a horizontal baffle, and bottom vanes attached to the contactor housing. The liquids enter the contactor in the range of 700-800 degrees Celsius. The liquids are separated in the rotor into a dense phase and a light phase which are discharged from the contactor. 6 figures.

  10. Centrifugal pyrocontactor

    DOEpatents

    Chow, Lorac S.; Leonard, Ralph A.

    1993-01-01

    A method for mixing and separating immiscible liquid salts and liquid metals in a centrifugal contractor. The method includes introducing the liquids into an annular mixing zone and intensely mixing the liquids using vertical vanes attached to a rotor cooperating with vertical baffles, a horizontal baffle, and bottom vanes attached to the contactor housing. The liquids enter the contactor in the range of 700-800 degrees Celsius. The liquids are separated in the rotor into a dense phase and a light phase which are discharged from the contactor.

  11. Filtration engineering study to upgrade the ETF

    SciTech Connect

    McDonald, F.N.N.

    1995-10-18

    Filtration technologies are evaluated which have potential to augment or upgrade the 200 Area Effluent Treatment Facility. The study was written in anticipation of treating future waste waters that have high fouling potentials. The Three ultrafilters judged to be capable of treating future waste waters are: hollow fiber, tubular, and centrifugal

  12. CENTRIFUGE END CAP

    DOEpatents

    Beams, J.W.; Snoddy, L.B.

    1960-08-01

    An end cap for ultra-gas centrifuges is designed to impart or remove angular momentum to or from the gas and to bring the entering gas to the temperature of the gas inside the centrifuge. The end cap is provided with slots or fins for adjusting the temperature and the angular momentum of the entering gas to the temperature and momentum of the gas in the centrifuge and is constructed to introduce both the inner and the peripheral stream into the centrifuge.

  13. Glomerular filtration rate

    MedlinePlus

    ... page: //medlineplus.gov/ency/article/007305.htm Glomerular filtration rate To use the sharing features on this page, please enable JavaScript. Glomerular filtration rate (GFR) is a test used to check ...

  14. Alternative filtration testing program: Pre-evaluation of test results

    SciTech Connect

    Georgeton, G.K.; Poirier, M.R.

    1990-09-28

    Based on results of testing eight solids removal technologies and one pretreatment option, it is recommended that a centrifugal ultrafilter and polymeric ultrafilter undergo further testing as possible alternatives to the Norton Ceramic filters. Deep bed filtration should be considered as a third alternative, if a backwashable cartridge filter is shown to be inefficient in separate testing.

  15. METHOD OF CENTRIFUGE OPERATION

    DOEpatents

    Cohen, K.

    1960-05-10

    A method of isotope separation is described in which two streams are flowed axially of, and countercurrently through, a cylindrical centrifuge bowl. Under the influence of a centrifugal field, the light fraction is concentrated in a stream flowing through the central portion of the bowl, whereas the heavy fraction is concentrated in a stream at the periphery thereof.

  16. Valve for gas centrifuges

    DOEpatents

    Hahs, C.A.; Rurbage, C.H.

    1982-03-17

    The invention is pneumatically operated valve assembly for simulatenously (1) closing gas-transfer lines connected to a gas centrifuge or the like and (2) establishing a recycle path between two on the lines so closed. The value assembly is especially designed to be compact, fast-acting, reliable, and comparatively inexpensive. It provides large reductions in capital costs for gas-centrifuge cascades.

  17. Rotary filtration system

    DOEpatents

    Herman, David T.; Maxwell, David N.

    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.

  18. Valve for gas centrifuges

    DOEpatents

    Hahs, Charles A.; Burbage, Charles H.

    1984-01-01

    The invention is a pneumatically operated valve assembly for simultaneously (1) closing gas-transfer lines connected to a gas centrifuge or the like and (2) establishing a recycle path between two of the lines so closed. The valve assembly is especially designed to be compact, fast-acting, reliable, and comparatively inexpensive. It provides large reductions in capital costs for gas-centrifuge cascades.

  19. Design parameters for rotating cylindrical filtration

    NASA Technical Reports Server (NTRS)

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

    2002-01-01

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

  20. 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

  1. 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

  2. Centrifugal main fuel pump

    SciTech Connect

    Cole, E.F.

    1986-08-26

    For a gas turbine power plant having a fuel supply and a fuel metering valve and variable geometry for the power plant including servo actuating mechanisms for the fuel metering valve and variable geometry, a fuel pumping system, is described to supply pressurized fuel for the servo actuating mechanisms and for the engine working fluid medium. The pumping system includes a centrifugal pump solely supplying the fuel to the fuel metering valve to be delivered to the power plant for its working fluid medium, a positive displacement pump in parallel with the centrifugal pump and solely to supply pressurized fuel to the servo actuating mechanisms for the fuel metering valve and for the variable geometry, and a boost pump means disposed in serial relationship with the positive displacement pump and the centrifugal pump for augmenting the pressure supplied by the positive displacement pump and the centrifugal pump during predetermined operating conditions of the power plant. The combined boost pump and centrifugal pump capability is sufficient to satisfy the vapor to liquid ratio requirements of the power during its entire operating envelope.

  3. SEAL FOR HIGH SPEED CENTRIFUGE

    DOEpatents

    Skarstrom, C.W.

    1957-12-17

    A seal is described for a high speed centrifuge wherein the centrifugal force of rotation acts on the gasket to form a tight seal. The cylindrical rotating bowl of the centrifuge contains a closure member resting on a shoulder in the bowl wall having a lower surface containing bands of gasket material, parallel and adjacent to the cylinder wall. As the centrifuge speed increases, centrifugal force acts on the bands of gasket material forcing them in to a sealing contact against the cylinder wall. This arrangememt forms a simple and effective seal for high speed centrifuges, replacing more costly methods such as welding a closure in place.

  4. Geotechnical centrifuge under construction

    NASA Astrophysics Data System (ADS)

    Richman, Barbara T.

    Modifications are underway at the National Aeronautics and Space Administration (NASA) Ames Research Center in California to transform a centrifuge used in the Apollo space program to the largest geotechnical centrifuge in the free world. The centrifuge, to be finished in August and opened next January, following check out and tuning, will enable geoscientists to model stratigraphic features down to 275 m below the earth's surface. Scientists will be able to model processes that are coupled with body force loading, including earthquake response of earth structures and soil structure interaction; rubbled-bed behavior during in situ coal gasification or in oil shale in situ retorts; behavior of frozen soil; frost heave; behavior of offshore structures; wave-seabed interactions; explosive cratering; and blast-induced liquefaction.The centrifuge will have a load capacity of 900-g-tons (short); that is, it will be able to carry a net soil load of 3 short tons to a centripetal acceleration of 300 times the acceleration caused by gravity. Modified for a total cost of $2.4 million, the centrifuge will have an arm with a 7.6-m radius and a swinging platform or bucket at its end that will be able to carry a payload container measuring 2.1×2.1 m. An additional future input of $500,000 would enable the purchase of a larger bucket that could accommodate a load of up to 20 tons, according to Charles Babendreier, program director for geotechnical engineering at the National Science Foundation. Additional cooling for the motor would also be required. The centrifuge has the capability of accelerating the 20-ton load to 100 g.

  5. Magnetic-seeding filtration

    SciTech Connect

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

    1997-10-01

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

  6. Human Powered Centrifuge

    NASA Technical Reports Server (NTRS)

    Mulenburg, Gerald M. (Inventor); Vernikos, Joan (Inventor)

    1997-01-01

    A human powered centrifuge has independently established turntable angular velocity and human power input. A control system allows excess input power to be stored as electric energy in a battery or dissipated as heat through a resistors. In a mechanical embodiment, the excess power is dissipated in a friction brake.

  7. Enhancing Centrifugal Separation With Electrophoresis

    NASA Technical Reports Server (NTRS)

    Herrmann, F. T.

    1986-01-01

    Separation of biological cells by coil-planet centrifuge enhanced by electrophoresis. By itself, coil-planet centrifuge offers relatively gentle method of separating cells under low centrifugal force in physiological medium that keeps cells alive. With addition of voltage gradient to separation column of centrifuge, separation still gentle but faster and more complete. Since separation apparatus contains no rotary seal, probability of leakage, contamination, corrosion, and short circuits reduced.

  8. Water sample filtration unit

    USGS Publications Warehouse

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

    1968-01-01

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

  9. Water Filtration Products

    NASA Technical Reports Server (NTRS)

    1986-01-01

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

  10. The Human Centrifuge

    NASA Astrophysics Data System (ADS)

    van Loon, Jack J. W. A.

    2009-01-01

    Life on Earth has developed at unit gravity, 9.81 m/s2, which was a major factor especially when vertebrates emerged from water onto land in the late Devonian, some 375 million years ago. But how would nature have evolved on a larger planet? We are able to address this question simply in experiments using centrifuges. Based on these studies we have gained valuable insights in the physiological process in plants and animals. They adapt to a new steady state suitable for the high-g environments applied. Information on mammalian adaptations to hyper-g is interesting or may be even vital for human space exploration programs. It has been shown in long duration animal hypergravity studies, ranging from snails, rats to primates, that various structures like muscles, bones, neuro-vestibular, or the cardio-vascular system are affected. However, humans have never been exposed to a hyper-g environment for long durations. Centrifuge studies involving humans are mostly in the order of hours. The current work on human centrifuges are all focused on short arm systems to apply short periods of artificial gravity in support of long duration space missions in ISS or to Mars. In this paper we will address the possible usefulness of a large human centrifuge on Earth. In such a centrifuge a group of humans can be exposed to hypergravity for, in principle, an unlimited period of time like living on a larger planet. The input from a survey under scientists working in the field of gravitational physiology, but also other disciplines, will be discussed.

  11. Visualization of water flow during filtration using flat filtration materials

    NASA Astrophysics Data System (ADS)

    Bílek, Petr; Šidlof, Petr; Hrůza, Jakub

    2012-04-01

    Filtration materials are very important elements of some industrial appliances. Water filtration is a separation of solid materials from fluid. Solid particles are captured on the frontal area of the filtration textile and only liquid passes through it. It is important to know the filtration process in a detailed way to be able to develop filtration materials. Visualization of filtration process enables a better view of the filtration. This method also enables to determine efficiency and homogeneity of filtration using image analysis. For this purpose, a new waterfiltration measuring setup was proposed and constructed. Filtration material is mounted into the optically transparent place in the setup. Laser sheet is directed into this place as in the case of Particle Image Velocimetry measuring method. Monochrome and sensitive camera records the light scattered by seeding particles in water. The seeding particles passing through the filter serve for measuring filtration efficiency, and also for visualization of filtration process. Filtration setup enables to measure also the pressure drop and a flow. The signals are processed by National Instruments compactDAQ system and UMA software. Microfibrous and nanofibrous filtration materials are tested by this measuring method. In the case of nanofibrous filtration, appropriate size of seeding particles is needed to be used to perform a process of filtration.

  12. Centrifugally decoupling touchdown bearings

    DOEpatents

    Post, Richard F

    2014-06-24

    Centrifugally decoupling mechanical bearing systems provide thin tensioned metallic ribbons contained in a support structure. This assembly rotates around a stationary shaft being centered at low speeds by the action of the metal ribbons. Tension springs are connected on one end to the ribbons and on the other end to the support structure. The ribbons pass through slots in the inner ring of the support structure. The spring preloading thus insures contact (or near-contact) between the ribbons and the shaft at rotation speeds below the transition speed. Above this speed, however, the centrifugal force on the ribbons produces a tensile force on them that exceeds the spring tensile force so that the ribbons curve outward, effectively decoupling them from mechanical contact with the shaft. They still remain, however, in position to act as a touchdown bearing in case of abnormally high transverse accelerations.

  13. Centrifugal pump fuel system

    SciTech Connect

    McGlone, M.E.; Larkins, L.J.; Johnson, R.O.; Moeller, K.A.

    1993-06-22

    A centrifugal pump fuel system for an engine driven fuel pump for an aircraft gas turbine engine is described comprising: a centrifugal pump having at constant speed rising head/flow characteristic at low flows; a plumbing system receiving flow from the pump, and having at least one control valve located down stream of and defining a discrete volume of the plumbing system; a plumbing resonant frequency defined by the discrete volume, the geometry of the plumbing system, and the bulk modulus of the fuel; a pressure difference regulating valve located adjacent to the discharge of the pump, up stream of the vast majority of the discrete volume; and the frequency response of the regulating valve being significantly less than the frequency response of the plumbing system such that the response of the regulating valve is attenuated at the resonant frequency of the plumbing system.

  14. Centrifugal unbalance detection system

    DOEpatents

    Cordaro, Joseph V.; Reeves, George; Mets, Michael

    2002-01-01

    A system consisting of an accelerometer sensor attached to a centrifuge enclosure for sensing vibrations and outputting a signal in the form of a sine wave with an amplitude and frequency that is passed through a pre-amp to convert it to a voltage signal, a low pass filter for removing extraneous noise, an A/D converter and a processor and algorithm for operating on the signal, whereby the algorithm interprets the amplitude and frequency associated with the signal and once an amplitude threshold has been exceeded the algorithm begins to count cycles during a predetermined time period and if a given number of complete cycles exceeds the frequency threshold during the predetermined time period, the system shuts down the centrifuge.

  15. Centrifugal adsorption system

    NASA Technical Reports Server (NTRS)

    Gonda, Steve R. (Inventor); Tsao, Yow-Min D. (Inventor); Lee, Wenshan (Inventor)

    2006-01-01

    A gas-liquid separator uses a helical passageway to impart a spiral motion to a fluid passing therethrough. The centrifugal force generated by the spiraling motion urges the liquid component of the fluid radially outward which forces the gas component radially inward. The gas component is then separated through a gas-permeable, liquid-impervious membrane and discharged through a central passageway. A filter material captures target substances contained in the fluid.

  16. Oscillatory counter-centrifugation

    NASA Astrophysics Data System (ADS)

    Xu, Shujing; Nadim, Ali

    2016-02-01

    In ordinary centrifugation, a suspended particle that is heavier than the displaced fluid migrates away from the rotation axis when the fluid-filled container rotates steadily about that axis. In contrast a particle that is lighter than the displaced fluid (e.g., a bubble) migrates toward the rotation axis in a centrifuge. In this paper, we show theoretically that if a fluid-filled container rotates in an oscillatory manner as a rigid body about an axis, at high enough oscillation frequencies, the sense of migration of suspended particles is reversed. That is, in that case particles denser than the fluid migrate inward, while those that are lighter than the fluid move outward. We term this unusual phenomenon "Oscillatory Counter-Centrifugation" or OCC, for short. Through application of the method of averaging to the equations of motion, we derive a simple criterion to predict the occurrence of OCC. The analysis also reveals that the time-average of the Coriolis force in the radial direction is the term that is responsible for this effect. In addition, we analyze the effects of the Basset history force and the Rubinow-Keller lift force on particle trajectories and find that OCC persists even when these forces are active. The phenomenon awaits experimental verification.

  17. C-018H LERF filtration test plan. Revision 1

    SciTech Connect

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

    1994-08-26

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

  18. Microfluidic colloid filtration

    NASA Astrophysics Data System (ADS)

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

    2016-03-01

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

  19. Filtration by eyelashes

    NASA Astrophysics Data System (ADS)

    Vistarakula, Krishna; Bergin, Mike; Hu, David

    2010-11-01

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

  20. Magnetic-seeding filtration

    SciTech Connect

    Depaoli, D.

    1996-10-01

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

  1. Gas Centrifuges and Nuclear Proliferation

    SciTech Connect

    Albright, David

    2004-09-15

    Gas centrifuges have been an ideal enrichment method for a wide variety of countries. Many countries have built gas centrifuges to make enriched uranium for peaceful nuclear purposes. Other countries have secretly sought centrifuges to make highly enriched uranium for nuclear weapons. In more recent times, several countries have secretly sought or built gas centrifuges in regions of tension. The main countries that have been of interest in the last two decades have been Pakistan, Iraq, Iran, and North Korea. Currently, most attention is focused on Iran, Pakistan, and North Korea. These states did not have the indigenous abilities to make gas centrifuges, focusing instead on illicit and questionable foreign procurement. The presentation covered the following main sections: Spread of centrifuges through illicit procurement; Role of export controls in stopping proliferation; Increasing the transparency of gas centrifuge programs in non-nuclear weapon states; and, Verified dismantlement of gas centrifuge programs. Gas centrifuges are important providers of low enriched uranium for civil nuclear power reactors. They also pose special nuclear proliferation risks. We all have special responsibilities to prevent the spread of gas centrifuges into regions of tension and to mitigate the consequences of their spread into the Middle East, South Asia, and North Asia.

  2. 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

  3. Water Treatment Technology - Filtration.

    ERIC Educational Resources Information Center

    Ross-Harrington, Melinda; Kincaid, G. David

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

  4. Centrifugal Adsorption Cartridge System

    NASA Technical Reports Server (NTRS)

    Gonda, Steve R.; Tsao, Yow-Min D.; Lee, Wenshan

    2004-01-01

    The centrifugal adsorption cartridge system (CACS) is an apparatus that recovers one or more bioproduct(s) from a dilute aqueous solution or suspension flowing from a bioreactor. The CACS can be used both on Earth in unit gravity and in space in low gravity. The CACS can be connected downstream from the bioreactor; alternatively, it can be connected into a flow loop that includes the bioreactor so that the liquid can be recycled. A centrifugal adsorption cartridge in the CACS (see figure) includes two concentric cylinders with a spiral ramp between them. The volume between the inner and outer cylinders, and between the turns of the spiral ramp is packed with an adsorbent material. The inner cylinder is a sieve tube covered with a gas-permeable, hydrophobic membrane. During operation, the liquid effluent from the bioreactor is introduced at one end of the spiral ramp, which then constrains the liquid to flow along the spiral path through the adsorbent material. The spiral ramp also makes the flow more nearly uniform than it would otherwise be, and it minimizes any channeling other than that of the spiral flow itself. The adsorbent material is formulated to selectively capture the bioproduct(s) of interest. The bioproduct(s) can then be stored in bound form in the cartridge or else eluted from the cartridge. The centrifugal effect of the spiral flow is utilized to remove gas bubbles from the liquid. The centrifugal effect forces the bubbles radially inward, toward and through the membrane of the inner cylinder. The gas-permeable, hydrophobic membrane allows the bubbles to enter the inner cylinder while keeping the liquid out. The bubbles that thus enter the cylinder are vented to the atmosphere. The spacing between the ramps determines rate of flow along the spiral, and thereby affects the air-bubble-removal efficiency. The spacing between the ramps also determines the length of the fluid path through the cartridge adsorbent, and thus affects the bioproduct

  5. National geotechnical centrifuge

    NASA Technical Reports Server (NTRS)

    Hallam, J. A.; Kunz, N.; Vallotton, W. C.

    1982-01-01

    A high G-ton centrifuge, able to take a 2700 kg (6000 lb) payload up to 300 G, is described. The stability of dams and embankments, the bearing capacity of soil foundations, and the dynamic behavior of foundations due to vibration of machinery are examples of applications. A power rating of 6,000 kW (9,000 hp) was established for the motor. An acceptable maximum speed of 70 rpm was determined. A speed increase with a ratio of 1:3 is discussed. The isolated tension straps, the anti-spreader bar and the flexwall bucket, and safety precautions are also discussed.

  6. Centrifugal-reciprocating compressor

    NASA Technical Reports Server (NTRS)

    Higa, W. H. (Inventor)

    1984-01-01

    A centrifugal compressor is described which includes at least one pair of cylinders arranged in coaxial alignment and supported for angular displacement about a common axis of rotation normally disecting a common longitudinal axis of symmetry for the cylinders. The cylinders are characterized by ported closures located at the mutually remote ends thereof through which the cylinders are charged and discharged, and a pair of piston heads seated within the cylinders and supported for floating displacement in compressive strokes in response to unidirectional angular displacement imparted to the cylinders.

  7. Evaluation of a Particulate Filtration System for an Alkaline Paint Stripper at Letterkenny Army Depot

    DTIC Science & Technology

    1991-08-01

    hydrostatic) filtration 12 3.1.4 Vacuum filtration 15 3.1.5 Hydrocyclone 15 3.1.6 Microfiltration NS EC 15 3.1.7 Sedimentation,. 19 3.1.8 Skimmers 19...a Centrifuge 13 4 Illustration of a Gravity Filter 14 5 Illustration of a Vacuum Filter 16 6 Illustration of a Hydrocyclone 17 7 Illustration of a...filtration o Hydrocyclone o Microfiltration o Sedimentation o Skimmers. Based upon the data presented in the Di- ft Assessment Report, discussions with

  8. Centrifuge impact cratering experiment 5

    NASA Technical Reports Server (NTRS)

    1984-01-01

    Transient crates motions, cratering flow fields, crates dynamics, determining impact conditions from total crater welt, centrifuge quarter-space cratering, and impact cratering mechanics research is documented.

  9. Centrifugal precipitation chromatography.

    PubMed

    Ito, Yoichiro; Qi, Lin

    2010-01-15

    Centrifugal precipitation chromatography separates analytes according their solubility in ammonium sulfate (AS) solution and other precipitants. The separation column is made from a pair of long spiral channels partitioned with a semipermeable membrane. In a typical separation, concentrated ammonium sulfate is eluted through one channel while water is eluted through the other channel in the opposite direction. This countercurrent process forms an exponential AS concentration gradient through the water channel. Consequently, protein samples injected into the water channel is subjected to a steadily increasing AS concentration and at the critical AS concentration they are precipitated and deposited in the channel bed by the centrifugal force. Then the chromatographic separation is started by gradually reducing the AS concentration in the AS channel which lowers the AS gradient concentration in the water channel. This results in dissolution of deposited proteins which are again precipitated at an advanced critical point as they move through the channel. Consequently, proteins repeat precipitation and dissolution through a long channel and finally eluted out from the column in the order of their solubility in the AS solution. The present method has been successfully applied to a number of analytes including human serum proteins, recombinant ketosteroid isomerase, carotenoid cleavage enzymes, plasmid DNA, polysaccharide, polymerized pigments, PEG-protein conjugates, etc. The method is capable to single out the target species of proteins by affinity ligand or immunoaffinity separation.

  10. Ultrasound-Assisted Extraction, Centrifugation and Ultrafiltration: Multistage Process for Polyphenol Recovery from Purple Sweet Potatoes.

    PubMed

    Zhu, Zhenzhou; Jiang, Tian; He, Jingren; Barba, Francisco J; Cravotto, Giancarlo; Koubaa, Mohamed

    2016-11-20

    This work provides an evaluation of an ultrasound-assisted, combined extraction, centrifugation and ultrafiltration process for the optimal recovery of polyphenols. A purple sweet potato (PSP) extract has been obtained using ultrasonic circulating extraction equipment at a power of 840 W, a frequency of 59 kHz and using water as solvent. Extract ultrafiltration, using polyethersulfone (PES), was carried out for the recovery of polyphenol, protein and anthocyanin. Pre-treatment, via the centrifugation of purple sweet potato extract at 2500 rpm over 6 min, led to better polyphenol recovery, with satisfactory protein removal (reused for future purposes), than PSP extract filtration without centrifugation. Results showed that anthocyanin was efficiently recovered (99%) from permeate. The exponential model fit well with the experimental ultrafiltration data and led to the calculation of the membrane's fouling coefficient. The optimization of centrifugation conditions showed that, at a centrifugation speed of 4000 rpm (1195× g) and duration of 7.74 min, the optimized polyphenol recovery and fouling coefficient were 34.5% and 29.5 m(-1), respectively. The removal of proteins in the centrifugation process means that most of the anthocyanin content (90%) remained after filtration. No significant differences in the intensities of the HPLC-DAD-ESI-MS² peaks were found in the samples taken before and after centrifugation for the main anthocyanins; peonidin-3-feruloylsophoroside-5-glucoside, peonidin-3-caffeoyl-p-hydroxybenzoylsophoroside-5-glucoside, and peonidin-3-caffeoyl-feruloyl sophoroside-5-glucoside. This proves that centrifugation is an efficient method for protein removal without anthocyanin loss. This study considers this process an ultrasound-assisted extraction-centrifugation-ultrafiltration for purple sweet potato valorization in "green" technology.

  11. Centrifuge treatment of coal tar

    SciTech Connect

    L.A. Kazak; V.Z. Kaidalov; L.F. Syrova; O.S. Miroshnichenko; A.S. Minakov

    2009-07-15

    New technology is required for the removal of water and heavy fractions from regular coal tar. Centrifuges offer the best option. Purification of coal tar by means of centrifuges at OAO NLMK permits the production of pitch coke or electrode pitch that complies with current standards.

  12. Unshrouded Centrifugal Turbopump Impeller

    NASA Technical Reports Server (NTRS)

    Prueger, George; Williams, Morgan; Chen, Wei; Paris, John; Stewart, Eric; Williams, Robert

    1999-01-01

    The ratio of rocket engine thrust to weight is a limiting constraint in placing more payload into orbit at a low cost. A key component of an engine's overall weight is the turbopump weight, Reducing the turbopump weight can result in significant engine weight reduction and hence, increased delivered payload. There are two main types of pumps: centrifugal and axial pumps. These types of pumps can be further sub-divided into those with shrouds and those without shrouds (unshrouded pumps). Centrifugal pumps can achieve the same pump discharge pressure as an axial pump and it requires fewer pump stages and lower pump weight than an axial pump. Also, with unshrouded centrifugal pumps (impeller), the number of stages and weight can be further reduced. However. there are several issues with regard to using an unshrouded impeller: 1) there is a pump performance penalty due to the front open face recirculation flow; 2) there is a potential pump axial thrust problem from the unbalanced front open face and the back shroud face; and, 3) since test data is very linu'ted for this configuration, there is uncertainty in the magnitude and phase of the rotordynamics forces due to the front impeller passage. The purpose of the paper is to discuss the design of an unshrouded impeller and to examine the design's hydrodynamic performance, axial thrust, and rotordynamics performance. The design methodology will also be discussed. This work will help provide some guidelines for unshrouded impeller design. In particular, the paper will discuss the design of three unshrouded impellers - one with 5 full and 5 partial blades (5+5). one with 6+6 blades and one with 8+8 blades. One of these designs will be selected for actual fabrication and flow test. Computational fluid dynamics (CFD) is used to help design and optimize the unshrouded impeller. The relative pump performance penalty is assessed by comparing the CFD results of the unshrouded impeller with the equivalent shrouded impeller for a

  13. Rat growth during chronic centrifugation

    NASA Technical Reports Server (NTRS)

    Pitts, G. C.; Oyama, J.

    1978-01-01

    Female weanling rats were chronically centrifuged at 4.15 G with controls at terrestrial gravity. Samples were sacrificed for body composition studies at 0, 28, 63, 105 and 308 days of centrifugation. The centrifuged group approached a significantly lower mature body mass than the controls (251 and 318g) but the rate of approach was the same in both groups. Retirement to 1G on the 60th day resulted in complete recovery. Among individual components muscle, bone, skin, CNS, heart, kidneys, body water and body fat were changed in the centrifuged group. However, an analysis of the growth of individual components relative to growth of the total fat-free compartment revealed that only skin (which increased in mass) was responding to centrifugation per se.

  14. [Galileo and centrifugal force].

    PubMed

    Vilain, Christiane

    This work intends to focus on Galileo's study of what is now called "centrifugal force," within the framework of the Second Day of his Dialogo written in 1632, rather than on the previously published commentaries on the topic. Galileo proposes three geometrical demonstrations in order to prove that gravity will always overcome centrifugalforce, and that the potential rotation of the Earth, whatever its speed, cannot in any case project objects beyond it. Each of these demonstrations must consequently contain an error and it has seemed to us that the first one had not been understood up until now. Our analysis offers an opportunity to return to Galileo's geometrical representation of dynamical questions; actually, we get an insight into the sophistication of Galileo's practices more than into his mistakes. Our second point, concerning the historiography of the problem, shows an evolution from anachronic critics to more contextual considerations, in the course of the second half of the twentieth century.

  15. Immunoaffinity centrifugal precipitation chromatography.

    PubMed

    Qi, Lin; Ito, Yoichiro

    2007-06-01

    Purification of proteins based on immunoaffinity has been performed using a solid support coated with antibody against the target proteins. The method requires immobilizing the antibody onto the solid support using protein A or G, and has a risk of adsorptive loss of target proteins onto the solid support. Centrifugal precipitation chromatography has been successfully used to purify enzymes, such as ketosteroid isomerase and hyaluronidase without the use of solid support. The purpose of this study is to demonstrate that immunoaffinity centrifugal precipitation chromatography is capable of isolating an antigen by exploiting antigen-antibody binding. The separation was initiated by filling both channels with 40% saturated ammonium sulfate (AS) of pH 4-4.5 followed by loading 20 microl of human plasma (National Institutes of Health blood bank) mixed with 2 mg of rabbit anti-HSA (human serum protein) antibody (Sigma). Then, the sample channel was eluted with water at 0.03 ml/min and AS channel with 40% AS solution of pH 4-4.5 at 1 ml/min until all non-binding components were eluted. Then, the releasing reagent (50% AS solution containing 0.5 M glycine and 10% ammonium hydroxide at pH 10) was introduced through the AS channel to release the target protein (HSA). The retained antibody was recovered by eluting the sample channel with water at 1 ml/min. A hollow fiber membrane device at the outlet (MicroKros, Spectrum, New Brunswick, NJ, USA) was provided on-line dialysis of the eluent before fractions were collected, so that the fractions could be analyzed by SDS-PAGE (sodium dodecyl sulfate - polyacrylamide gel electrophoresis) without further dialysis. The current method does not require immobilizing the antibody onto a matrix, which is used by the conventional immunoaffinity chromatography. This method ensures full recovery of the antigen and antibody, and it may be applied to purification of other proteins.

  16. Gas centrifuge purge method

    DOEpatents

    Theurich, Gordon R.

    1976-01-01

    1. In a method of separating isotopes in a high speed gas centrifuge wherein a vertically oriented cylindrical rotor bowl is adapted to rotate about its axis within an evacuated chamber, and wherein an annular molecular pump having an intake end and a discharge end encircles the uppermost portion of said rotor bowl, said molecular pump being attached along its periphery in a leak-tight manner to said evacuated chamber, and wherein end cap closure means are affixed to the upper end of said rotor bowl, and a process gas withdrawal and insertion system enters said bowl through said end cap closure means, said evacuated chamber, molecular pump and end cap defining an upper zone at the discharge end of said molecular pump, said evacuated chamber, molecular pump and rotor bowl defining a lower annular zone at the intake end of said molecular pump, a method for removing gases from said upper and lower zones during centrifuge operation with a minimum loss of process gas from said rotor bowl, comprising, in combination: continuously measuring the pressure in said upper zone, pumping gas from said lower zone from the time the pressure in said upper zone equals a first preselected value until the pressure in said upper zone is equal to a second preselected value, said first preselected value being greater than said second preselected value, and continuously pumping gas from said upper zone from the time the pressure in said upper zone equals a third preselected value until the pressure in said upper zone is equal to a fourth preselected value, said third preselected value being greater than said first, second and fourth preselected values.

  17. Dynamic optical filtration

    NASA Technical Reports Server (NTRS)

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

    2005-01-01

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

  18. Dynamic Optical Filtration

    NASA Technical Reports Server (NTRS)

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

    2005-01-01

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

  19. Melt Purification via Filtration

    DTIC Science & Technology

    1981-06-01

    4 ) c. re: " exp((|)n) + exp -i e ^ ( 6 - n) ’m - 7 - - 1 t where the subscript i refers to the inlet condition...temperature model system studies. 4 . PROGRESS TO DATE The phase of the work investigating the filtration of the aluminum- titanium diboride system through...CO 4 -1 3 O >, 3 6 ^ -H 4 -1 O B 3 SH 3 _^ u r-i a O 3 O CU SO rH 3 M w -H ca E l e c t r o l

  20. Magnetic-seeding filtration

    SciTech Connect

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

    1997-10-01

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

  1. HOUSINGS AND MOUNTINGS FOR CENTRIFUGES

    DOEpatents

    Rushing, F.C.

    1960-08-16

    A protective housing for a gas centrifuge comprises a slidable connection between flanges and framework portions for absorbing rotational energy in case of bursting of the rotor and a sealing means for sealing the rotor chamber.

  2. Centrifugal dryers keep pace with the market

    SciTech Connect

    Fiscor, S.

    2008-03-15

    New plant design and upgrades create a shift in dewatering strategies. The article describes recent developments. Three major manufacturers supply centrifugal dryers - TEMA, Centrifugal & Mechanical Industries (CMI) and Ludowici. CMI introduced a line of vertical centrifugal dryers. TEMA improved the techniques by developing a horizontal vibratory centrifuge (HVC) which simplified maintenance. 3 figs., 1 photo.

  3. Microwave assisted centrifuge and related methods

    DOEpatents

    Meikrantz, David H [Idaho Falls, ID

    2010-08-17

    Centrifuge samples may be exposed to microwave energy to heat the samples during centrifugation and to promote separation of the different components or constituents of the samples using a centrifuge device configured for generating microwave energy and directing the microwave energy at a sample located in the centrifuge.

  4. Variable-Speed Instrumented Centrifuges

    NASA Technical Reports Server (NTRS)

    Chapman, David K.; Brown, Allan H.

    1991-01-01

    Report describes conceptual pair of centrifuges, speed of which varied to produce range of artificial gravities in zero-gravity environment. Image and data recording and controlled temperature and gravity provided for 12 experiments. Microprocessor-controlled centrifuges include video cameras to record stop-motion images of experiments. Potential applications include studies of effect of gravity on growth and on production of hormones in corn seedlings, experiments with magnetic flotation to separate cells, and electrophoresis to separate large fragments of deoxyribonucleic acid.

  5. Centrifugal Compressor Aeroelastic Analysis Code

    NASA Astrophysics Data System (ADS)

    Keith, Theo G., Jr.; Srivastava, Rakesh

    2002-01-01

    Centrifugal compressors are very widely used in the turbomachine industry where low mass flow rates are required. Gas turbine engines for tanks, rotorcraft and small jets rely extensively on centrifugal compressors for rugged and compact design. These compressors experience problems related with unsteadiness of flowfields, such as stall flutter, separation at the trailing edge over diffuser guide vanes, tip vortex unsteadiness, etc., leading to rotating stall and surge. Considerable interest exists in small gas turbine engine manufacturers to understand and eventually eliminate the problems related to centrifugal compressors. The geometric complexity of centrifugal compressor blades and the twisting of the blade passages makes the linear methods inapplicable. Advanced computational fluid dynamics (CFD) methods are needed for accurate unsteady aerodynamic and aeroelastic analysis of centrifugal compressors. Most of the current day industrial turbomachines and small aircraft engines are designed with a centrifugal compressor. With such a large customer base and NASA Glenn Research Center being, the lead center for turbomachines, it is important that adequate emphasis be placed on this area as well. Currently, this activity is not supported under any project at NASA Glenn.

  6. Removal of Inclusions from Molten Aluminum by Supergravity Filtration

    NASA Astrophysics Data System (ADS)

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

    2016-12-01

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

  7. Modus of filtration.

    PubMed

    Meltzer, Theodore H

    2006-01-01

    Experience teaches that particles larger than the pores of a filter cannot negotiate its passage. Other retention mechanisms are less obvious than sieve retention or size exclusion. They are electrical in nature, and find expression in the bonding alliances that mutually attract (or repel) filters and particles. The influence of hydrogen bonds, of van der Waals forces, of hydrophobic adsorptions, and of transient polarities on particle retentions are set forth in terms of the double electrical layer concept that also governs colloidal destabilizations. The origins of differences in membrane porosities is explained, as also the importance of the filtration conditions. The singularity of the particle-fluid-filter relationship on organism and/or pore size alteration is stressed.

  8. Filtration: Principles and practices. 2. edition

    SciTech Connect

    Matteson, M.J.; Orr, C.

    1998-12-31

    This new book is the most authoritative and comprehensive guide to essential, state-of-the-art data. It provides the very latest theoretical and practical data on filtration for gas and liquids. The 2nd edition has been revised and updated to include several new chapters which detail filtration in the mineral industry, high-efficiency air filtration, cartridge filters, and ultrafiltration. The contents include: Gas filtration theory; Liquid-filtration theory; Filter media; Industrial gas filtration; Filtration pretreatment; Filtration in the chemical process industry; Ultrafiltration; Filtration in the mineral industry; Filtration in heating, ventilating, and air conditioning; Cartridge filtration; High-efficiency air filtration; Analytical applications of filtration; and Filter evaluation and testing.

  9. Use of the Centritech Lab centrifuge for perfusion culture of hybridoma cells in protein-free medium.

    PubMed

    Johnson, M; Lanthier, S; Massie, B; Lefebvre, G; Kamen, A A

    1996-01-01

    As part of an effort to develop a suspension-culture perfusion-based process with high flow rate without the fouling and antibody retention inherent to filter-based cell-separation devices, we have evaluated and contributed to the development of the Centritech Lab centrifuge for the perfusion culture of hybridoma cells in protein-free medium. Culture start-ups showed that cell growth and monoclonal-antibody (MAb) production rates were similar in both a spinner flask and continuous centrifugation coupled to a bioreactor. The centrifuge efficiently separated viable cells from dead ones. Viable-cell recoveries were never below 98%, whereas dead-cell recoveries were usually around 80%. The cell content of the centrifuge supernatant and concentrate was strongly determined by the total amount of cells, viable and dead, in the culture broth, but an influence of the centrifugation parameters (feed rate, times of separation and discharge, and rotor speed) was observed. This understanding of the separation process inside the centrifuge is important and may apply to other similar devices. Monoclonal antibodies were not retained in the bioreactor during centrifugation perfusion. However, whereas similar growth rates were obtained in perfusion cultures using either continuous centrifugation or filtration, MAb concentrations were 35% lower in the former case. Utilization of the centrifuge in an intermittent fashion decreased the daily cell residence time outside the bioreactor, the daily pelleted-cell residence time in the centrifuge, and the frequency of cell passage to the centrifuge. This led to higher viable-cell numbers in the bioreactor and an accompanying increase in MAb concentrations, 225-250 mg of IgM L-1, equal to the performance of filter-based perfusion systems with the same cell line. It was hypothesized that having cells periodically packed at the bottom of the centrifuge insert (up to 800 x 10(6) cells mL-1) is deleterious to the culture by exposing the pelleted

  10. A PERSPECTIVE OF RIVERBANK FILTRATION

    EPA Science Inventory

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

  11. 40 CFR 141.173 - Filtration.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

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

  12. 40 CFR 141.173 - Filtration.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

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

  13. 40 CFR 141.173 - Filtration.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

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

  14. 40 CFR 141.173 - Filtration.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

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

  15. 40 CFR 141.173 - Filtration.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

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

  16. Centrifuge-Based Fluidic Platforms

    NASA Astrophysics Data System (ADS)

    Zoval, Jim; Jia, Guangyao; Kido, Horacio; Kim, Jitae; Kim, Nahui; Madou, Marc

    In this chapter centrifuge-based microfluidic platforms are reviewed and compared with other popular microfluidic propulsion methods. The underlying physical principles of centrifugal pumping in microfluidic systems are presented and the various centrifuge fluidic functions such as valving, decanting, calibration, mixing, metering, heating, sample splitting, and separation are introduced. Those fluidic functions have been combined with analytical measurements techniques such as optical imaging, absorbance and fluorescence spectroscopy and mass spectrometry to make the centrifugal platform a powerful solution for medical and clinical diagnostics and high-throughput screening (HTS) in drug discovery. Applications of a compact disc (CD)-based centrifuge platform analyzed in this review include: two-point calibration of an optode-based ion sensor, an automated immunoassay platform, multiple parallel screening assays and cellular-based assays. The use of modified commercial CD drives for high-resolution optical imaging is discussed as well. From a broader perspective, we compare the technical barriers involved in applying microfluidics for sensing and diagnostic as opposed to applying such techniques to HTS. The latter poses less challenges and explains why HTS products based on a CD fluidic platform are already commercially available, while we might have to wait longer to see commercial CD-based diagnostics.

  17. Hemolysis in different centrifugal pumps.

    PubMed

    Kawahito, K; Nosé, Y

    1997-04-01

    Different types of centrifugal pumps cause different amounts of hemolysis based on shear stress and blood exposure time. However, the hemolytic characteristics of centrifugal pumps in each clinical condition are not always clear. We compared the hemolytic characteristics of one cone-type centrifugal pump (Medtronic BioMedicus BP-80) and 2 impeller-type centrifugal pumps (Nikkiso HMS-12 and Terumo Capiox) under experimental conditions simulating their use in cardiopulmonary bypass (CPB), extracorporeal membrane oxygenation (ECMO), and percutaneous cardiopulmonary support (PCPS) as well as their use as left ventricular assist devices (LVADs). The normalized indexes of hemolysis (NIHs; grams free plasma hemoglobin per 100 L blood pumped) during use as LVADs were not significantly different among the 3 pumps. The BP-80 pump produced almost 3-fold more hemolysis than the HMS-12 and Capiox pumps during CPB, 3- to 4-fold more hemolysis during ECMO, and 5.5-fold more hemolysis during PCPS. The 2 impeller-type centrifugal pumps will therefore cause less hemolysis under high flow, high pressure difference (as in CPB) and low flow, high pressure difference (as in ECMO and PCPS) conditions than the cone-type pump.

  18. Improving the quality of graphene oxide prepared by Hummer's method by using centrifugation

    NASA Astrophysics Data System (ADS)

    Ardakani, Seyed Esmaeil Mahdavi; Singh, Balbir Singh Mahinder; Mohammed, Norani Muti

    2015-07-01

    Hummer's method is one of the most popular methods for preparing graphene oxide. This method requires fewer hazardous materials and is carried out at lower temperatures. The graphene oxide sheets prepared by this approach, contains various functional groups such as epoxide and hydroxyl. The oxidation of graphite by powerful oxidants used in this method is not easily controllable and this causes the quality exfoliated sheets to vary. Furthermore, reducing the PH of the solution and washing the sample in the final stage of process by filtration cannot separate the nanosheets. Hence, in this study, washing of the samples by distilled water in the filtration setup was replaced by centrifuge approach. The microscopic characterizations like TEM, FESEM, SAED and EDX that were carried out revealed that centrifuging the samples gave better outcomes for the Hummer's method.

  19. Centrifugal slip casting of components

    SciTech Connect

    Steinlage, G.A.; Roeder, R.K.; Trumble, K.P.; Bowman, K.J.

    1996-05-01

    Research in layered and functionally gradient materials has emerged because of the increasing demand for high-performance engineering materials. Many techniques have been used to produce layered and functionally gradient components. Common examples include thermal spray processing, powder processing, chemical and physical vapor deposition, high-temperature or combustion synthesis, diffusion treatments, microwave processing and infiltration. Of these techniques, powder processing routes offer excellent microstructural control and product quality, and they are capable of producing large components. Centrifugal slip casting is a powder-processing technique combining the effects of slip casting and centrifugation. In slip casting, consolidation takes place as fluid is removed by the porous mold. Particles within the slip move with the suspending fluid until reaching the mold wall, at which point they are consolidated. In centrifugation, particles within the slip move through the fluid at a rate dependent upon the gravitational force and particle drag.

  20. Simulated stand tests and centrifuge training to prevent orthostatic intolerance on Earth, moon, and Mars.

    PubMed

    Coats, Brandon W; Sharp, M Keith

    2010-03-01

    One proposed method to overcome postflight orthostatic intolerance is for astronauts to undergo inflight centrifugation. Cardiovascular responses were compared between centrifuge and gravitational conditions using a seven-compartment cardiovascular model. Vascular resistance, heart rate, and stroke volume values were adopted from literature, while compartmental volumes and compliances were derived from impedance plethysmography of subjects (n=8) riding on a centrifuge. Three different models were developed to represent the typical male subject who completed a 10-min postflight stand test ("male finisher"), "non-finishing male" and "female" (all non-finishers). A sensitivity analysis found that both cardiac output and arterial pressure were most sensitive to total blood volume. Simulated stand tests showed that female astronauts were more susceptible to orthostatic intolerance due to lower initial blood pressure and higher pressure threshold for presyncope. Rates of blood volume loss by capillary filtration were found to be equivalent in female and male non-finishers, but four times smaller in male finishers. For equivalent times to presyncope during centrifugation as those during constant gravity, lower G forces at the level of the heart were required. Centrifuge G levels to match other cardiovascular parameters varied depending on the parameter, centrifuge arm length, and the gravity level being matched.

  1. Centrifugation and the Manhattan Project

    NASA Astrophysics Data System (ADS)

    Reed, Cameron

    2009-05-01

    A study of U. S. Army Manhattan Engineer District documents reveals that consideration of centrifugation as a means of uranium enrichment during World War II was considerably more extensive than is commonly appreciated. By the time the centrifuge project was abandoned in early 1944 a full-scale prototype unit had been fabricated and tested at near-production speeds, enrichments of close to theoretically-expected levels had been demonstrated with pilot-plant units, and plans for production plants had been developed. This paper will review the history of this little-known aspect of the Project and examine the circumstances of how it came to be discontinued.

  2. Centrifugation and the Manhattan Project

    NASA Astrophysics Data System (ADS)

    Reed, Cameron

    2009-04-01

    A study of U. S. Army Manhattan Engineer District documents reveals that consideration of centrifugation as a means of uranium enrichment during World War II was considerably more extensive than is commonly appreciated. By the time the centrifuge project was abandoned in early 1944 a full-scale prototype unit had been fabricated and tested at near-production speeds, enrichments of close to theoretically-expected levels had been demonstrated with pilot-plant units, and plans for production plants had been developed. This paper will review the history of this little-known aspect of the Project and examine the circumstances of how it came to be discontinued.

  3. MEANS FOR DETERMINING CENTRIFUGE ALIGNMENT

    DOEpatents

    Smith, W.Q.

    1958-08-26

    An apparatus is presented for remotely determining the alignment of a centrifuge. The centrifage shaft is provided with a shoulder, upon which two followers ride, one for detecting radial movements, and one upon the shoulder face for determining the axial motion. The followers are attached to separate liquid filled bellows, and a tube connects each bellows to its respective indicating gage at a remote location. Vibrations produced by misalignment of the centrifuge shaft are transmitted to the bellows, and tbence through the tubing to the indicator gage. This apparatus is particularly useful for operation in a hot cell where the materials handled are dangerous to the operating personnel.

  4. A simplified protein precipitation and filtration procedure for determining serum vitamin B6 by high-performance liquid chromatography.

    PubMed

    Rybak, Michael E; Pfeiffer, Christine M

    2009-05-01

    Protein precipitation followed by centrifuge filtration was tested as a simplified sample preparation procedure for quantifying pyridoxal 5'-phosphate (PLP) and 4-pyridoxic acid (4PA) in serum by high-performance liquid chromatography. Serum samples (n=160) were prepared by both centrifuge filtration and an established technique using traditional supernatant extraction with manual filtration. Bland-Altman bias analysis (95% confidence levels [CLs]) of the results showed a -1.3 (-2.2, -0.5)% difference in PLP values and a -6.2 (-7.3, -5.2)% difference in 4PA values using the simplified sample preparation. These deviations were found to be well within allowable biases on the basis of biologic variation.

  5. Life Sciences Centrifuge Facility assessment

    NASA Technical Reports Server (NTRS)

    Benson, Robert H.

    1994-01-01

    This report provides an assessment of the status of the Centrifuge Facility being developed by ARC for flight on the International Space Station Alpha. The assessment includes technical status, schedules, budgets, project management, performance of facility relative to science requirements, and identifies risks and issues that need to be considered in future development activities.

  6. Life Sciences Centrifuge Facility review

    NASA Technical Reports Server (NTRS)

    Young, Laurence R.

    1994-01-01

    The Centrifuge Facility Project at ARC was reviewed by a code U team to determine appropriateness adequacy for the ISSA. This report represents the findings of one consultant to this team and concentrates on scientific and technical risks. This report supports continuation of the project to the next phase of development.

  7. Axial-Centrifugal Compressor Program

    DTIC Science & Technology

    1975-10-01

    We also wish to thank Robert Langworthy of the Eustis Directorate for his timely assistance and constructive guidance. 3, INj TABLE OF CONTENTS Page...34 PREFACE 3 LIST OF ILLUSTRATIONS ..................... 7 LIST OF TABLES . . . . . . . . . . . . . . . . . . . . . . . . . 17 INTRODUCTIONB...Blow Test. 132 Axial IGV Blow Test . . . . . . . . ........... 141 PMIZ ?crn AM BLANK-NOT 1=43D TABLE OF CONTENTS - Continued Centrifugal Compressor

  8. Centrifugal pumps for rocket engines

    NASA Technical Reports Server (NTRS)

    Campbell, W. E.; Farquhar, J.

    1974-01-01

    The use of centrifugal pumps for rocket engines is described in terms of general requirements of operational and planned systems. Hydrodynamic and mechanical design considerations and techniques and test procedures are summarized. Some of the pump development experiences, in terms of both problems and solutions, are highlighted.

  9. Laser and gas centrifuge enrichment

    SciTech Connect

    Heinonen, Olli

    2014-05-09

    Principles of uranium isotope enrichment using various laser and gas centrifuge techniques are briefly discussed. Examples on production of high enriched uranium are given. Concerns regarding the possibility of using low end technologies to produce weapons grade uranium are explained. Based on current assessments commercial enrichment services are able to cover the global needs of enriched uranium in the foreseeable future.

  10. Health benefits of particle filtration.

    PubMed

    Fisk, W J

    2013-10-01

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

  11. Health Benefits of Particle Filtration

    SciTech Connect

    Fisk, William J.

    2013-10-01

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

  12. Health Benefits of Particle Filtration

    SciTech Connect

    Fisk, William J.

    2013-10-01

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

  13. 40 CFR 141.73 - Filtration.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... PRIMARY DRINKING WATER REGULATIONS Filtration and Disinfection § 141.73 Filtration. A public water system... filtration, the turbidity level of representative samples of a system's filtered water must be less than or....74 (a)(1) and (c)(1). (d) Other filtration technologies. A public water system may use a...

  14. 40 CFR 141.73 - Filtration.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... PRIMARY DRINKING WATER REGULATIONS Filtration and Disinfection § 141.73 Filtration. A public water system... filtration, the turbidity level of representative samples of a system's filtered water must be less than or....74 (a)(1) and (c)(1). (d) Other filtration technologies. A public water system may use a...

  15. 40 CFR 141.73 - Filtration.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... PRIMARY DRINKING WATER REGULATIONS Filtration and Disinfection § 141.73 Filtration. A public water system... filtration, the turbidity level of representative samples of a system's filtered water must be less than or....74 (a)(1) and (c)(1). (d) Other filtration technologies. A public water system may use a...

  16. 40 CFR 141.73 - Filtration.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... PRIMARY DRINKING WATER REGULATIONS Filtration and Disinfection § 141.73 Filtration. A public water system... filtration, the turbidity level of representative samples of a system's filtered water must be less than or....74 (a)(1) and (c)(1). (d) Other filtration technologies. A public water system may use a...

  17. 40 CFR 141.73 - Filtration.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... PRIMARY DRINKING WATER REGULATIONS Filtration and Disinfection § 141.73 Filtration. A public water system... filtration, the turbidity level of representative samples of a system's filtered water must be less than or....74 (a)(1) and (c)(1). (d) Other filtration technologies. A public water system may use a...

  18. Design of a centrifugal blood pump: Heart Turcica Centrifugal.

    PubMed

    Demir, Onur; Biyikli, Emre; Lazoglu, Ismail; Kucukaksu, Suha

    2011-07-01

    A prototype of a new implantable centrifugal blood pump system named Heart Turcica Centrifugal (HTC) was developed as a left ventricular assist device (LVAD) for the treatment of end-stage cardiac failure. In the development of HTC, effects of blade height and volute tongue profiles on the hydraulic and hemolytic performances of the pump were investigated. As a result, the prototype was manufactured using the best blade height and volute tongue profiles. Performance of the prototype model was experimentally evaluated in a closed-loop flow system using water as the medium. The hydraulic performance requirement of an LVAD (5 L/min flow rate against a pressure difference of 100 mm Hg) was attained at 2800 rpm rotational speed.

  19. Centrifugal separator devices, systems and related methods

    DOEpatents

    Meikrantz, David H [Idaho Falls, ID; Law, Jack D [Pocatello, ID; Garn, Troy G [Idaho Falls, ID; Todd, Terry A [Aberdeen, ID; Macaluso, Lawrence L [Carson City, NV

    2012-03-20

    Centrifugal separator devices, systems and related methods are described. More particularly, fluid transfer connections for a centrifugal separator system having support assemblies with a movable member coupled to a connection tube and coupled to a fixed member, such that the movable member is constrained to movement along a fixed path relative to the fixed member are described. Also, centrifugal separator systems including such fluid transfer connections are described. Additionally, methods of installing, removing and/or replacing centrifugal separators from centrifugal separator systems are described.

  20. When to maintain centrifugal pumps

    SciTech Connect

    Karassik, I.J.

    1993-04-01

    Centrifugal pumps comprise critical maintenance equipment. The rationale of when to maintain them relates to a spreading tendency to contain costs in the face of tight money. Plant managers are thus entitled to a thorough analysis of whether reduced expenditures truly lower costs or actually hinder maintenance and increase costs. Absence of such an analysis hides the fact that proper and timely maintenance has a double effect: it not only reduces power consumption but also extends equipment life, and thus reduces the frequency of labor and material expenditures for scheduled or crisis maintenance. Centrifugal pump maintenance can demonstrate well the validity of this observation. The paper discusses: restoring internal clearances; real cost of renewing clearances; and monitoring clearances and pump performance.

  1. Development of Advanced Centrifugal Pumps

    SciTech Connect

    Rohatgi, U.

    2009-09-30

    A CRADA project was performed between BNL and Flowserve, California, under the auspices of Initiative for Proliferation Prevention (IPP) with the DOE support. The purpose was to jointly support a team of Russian institutes led by Kurchatov Institute to develop technology to increase operating life of centrifugal pumps. The work was performed from March 1, 2002 to September 30, 2009. The project resulted in development and validation the total cost of the sub-contract with Kurchatov Institute was $700,000, with matching fund from the industrial partner, Flowserve. The technical objective of this project is to develop advanced centrifugal pumps for the power, petroleum, chemical and water services industries by increasing the reliability of pumping equipment without a corresponding increase in life cycle cost. This major market need can be served by developing centrifugal pumps that generate only modest forces on the mechanical system even when operating under significant off-design conditions. This project is focused towards understanding the origin of hydraulic forces (both radial and axial, steady and time-dependent) and to develop design options, which reduce these forces over a broad flow range. This focus will include the force generation due to cavitation inside the pump as the operating conditions extend to low suction pressures. The results of research will reduce the inception of cavitation that leads to surface erosion and to find passive method of reducing peaks in axial thrust during whole range of flow rates.

  2. Investigation of the Aerodynamic Drag of an Eight-Channel Centrifugal Filter

    NASA Astrophysics Data System (ADS)

    Serebryanskii, D. A.; Semenyuk, N. S.; Plashikhin, S. V.

    2015-03-01

    The aerodynamic characteristics and the structure of vortices of the central region of the channel system of an eight-channel centrifugal filter have been investigated. An overview of the foreign and home literature on the filtration of solid particles in the gas flow in centrifugal apparatuses is given [1, 2]. We present the design and the principle of operation of the eight-channel centrifugal filter based on a system of curvilinear channels with equal turn angles and equal cross-sectional areas connected in series. We have performed numerical calculations of the dependence of the aerodynamic drag of the centrifugal filter on the rate of fl ow obtained by three different methods: analytical calculation, experiments on the laboratory facility, and with the help of modern means of computer modeling. Computational modeling of the flow was carried out by solving Reynolds (RANS, Reynolds-averaged Navier-Stokes) equations by the SFD method with the use of a k-ɛ model of turbulence for three modes of operation of the apparatus. The results of computer modeling permitted visualizing the vortex structure of the central region of the separation chamber in the form of 3D graphs. The obtained results have been confirmed experimentally on a laboratory model of the centrifugal filter of capacity up to 200 m3/h of purified air.

  3. Harvesting microalgal biomass using a magnetically induced membrane vibration (MMV) system: filtration performance and energy consumption.

    PubMed

    Bilad, M R; Discart, V; Vandamme, D; Foubert, I; Muylaert, K; Vankelecom, Ivo F J

    2013-06-01

    This study was performed to investigate the effectiveness of submerged microfiltration to harvest both a marine diatom Phaeodactylum tricornutum and a Chlorella vulgaris in a recently developed magnetically induced membrane vibrating (MMV) system. We assess the filtration performance by conducting the improved flux step method (IFM), fed-batch concentration filtrations and membrane fouling autopsy using two lab-made membranes with different porosity. The full-scale energy consumption was also estimated. Overall results suggest that the MMV offers a good fouling control and the process was proven to be economically attractive. By combining the membrane filtration (15× concentration) with centrifugation to reach a final concentration of 25% w/v, the energy consumption to harvest P. tricornutum and C. vulgaris was, respectively, as low as 0.84 and 0.77kWh/m(3), corresponding to 1.46 and 1.39 kWh/kg of the harvested biomass.

  4. Filtrates and Residues: Gel Filtration--An Innovative Separation Technique.

    ERIC Educational Resources Information Center

    Blumenfeld, Fred; Gardner, James

    1985-01-01

    Gel filtration is a form of liquid chromatography that separates molecules primarily on the basis of their size. Advantages of using this technique, theoretical aspects, and experiments (including procedures used) are discussed. Several questions for students to answer (with answers) are also provided. (JN)

  5. Twinning of amphibian embryos by centrifugation

    NASA Technical Reports Server (NTRS)

    Black, S. D.

    1984-01-01

    In the frog Xenopus laevis, the dorsal structures of the embryonic body axis normally derive from the side of the egg opposite the side of sperm entry. However, if the uncleaved egg is inclined at lg or centrifuged in an inclined position, this topographic relationship is overridden: the egg makes its dorsal axial structures according to its orientation in the gravitational/centrifugal field, irrespective of the position of sperm entry. Certain conditions of centrifugation cause eggs to develop into conjoined twins with two sets of axial structures. A detailed analysis of twinning provided some insight into experimental axis orientation. First, as with single-axis embryos, both axes in twins are oriented according to the direction of centrifugation. One axis forms at the centripetal side of the egg and the other forms at the centrifugal side, even when the side of sperm entry is normal to the centrifugal force vector. Second, if eggs are centrifuged to give twins, but are inclined at lg to prevent post-centrifugation endoplasmic redistributions, only single-axis embryos develop. Thus, a second redistribution is required for high-frequency secondary axis formation. This can be accomplished by lg (as in the single centrifugations) or by a second centrifugation directed along the egg's animal-vegetal axis.

  6. Public health protection through bank filtration - Kearney Nebraska case study

    NASA Astrophysics Data System (ADS)

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

    2003-04-01

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

  7. The application of cross-flow filtration to the collection of colloids and their associated metals in seawater

    NASA Astrophysics Data System (ADS)

    Moran, S. B.

    A variety of techniques have been used for the collection of colloidal material in natural waters; for example, centrifugation, filtration, ultrafiltration, dialysis, gel-permeation chromatography and field-flow fractionation [e.g. Karaiskakis et al., 1982; Laxen and Chandler, 1982; de Mora and Harrison, 1983; Salbu et al., 1985; Giddings, 1988]. There have been few studies of the size speciation of trace materials, organic or inorganic, in oceanic waters due primarily to problems of contamination and slow filtration rates (e.g. mL hr-1) associated with conventional ultrafiltration equipment. A relatively new technique for marine applications, crossflow filtration (CFF), has the potential to overcome both of these problems. Cross-flow, or tangential-flow, filtration has been used in such disciplines as medical research, sewage treatment and microbiology. However, the application of this technique to oceanographic studies has only recently been reported [e.g. Whitehouse et al., 1986, 1990; Moran and Moore, 1989].

  8. Filtration combustion: Smoldering and SHS

    NASA Technical Reports Server (NTRS)

    Matkowsky, Bernard J.

    1995-01-01

    Smolder waves and SHS (self-propagating high-temperature synthesis) waves are both examples of combustion waves propagating in porous media. When delivery of reactants through the pores to the reaction site is an important aspect of the process, it is referred to as filtration combustion. The two types of filtration combustion have a similar mathematical formulation, describing the ignition, propagation and extinction of combustion waves in porous media. The goal in each case, however, is different. In smoldering the desired goal is to prevent propagation, whereas in SHS the goal is to insure propagation of the combustion wave, leading to the synthesis of desired products. In addition, the scales in the two areas of application may well differ. For example, smoldering generally occurs at a relatively low temperature and with a smaller propagation velocity than SHS filtration combustion waves. Nevertheless, the two areas of application have much in common, so that mechanisms learned about in one application can be used to advantage in the other. In this paper we discuss recent results in the areas of filtration combustion.

  9. Improving IAQ Via Air Filtration.

    ERIC Educational Resources Information Center

    Monk, Brian

    1999-01-01

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

  10. MICROBIOLOGICAL REMOVAL BY FILTRATION PROCESSES

    EPA Science Inventory

    Filtration ws originally used to remove contaminants that affect the appearance, odor, and taste of drinking water. Later it was demonstrated that bacteria in drinking water were causative agents of disease. Water treatment technology improved with the addition of disinfection, c...

  11. ITP Filtrate Benzene Removal Alternatives

    SciTech Connect

    Dworjanyn, L.O.

    1993-05-21

    Existing ITP filtrate hold tanks may provide sufficient capacity and residence time to strip dissolved benzene from the incoming filtrate using nitrogen sparging in the bottom of the old tanks. This is based on equilibrium supported by late Wash test data using aged washed slurry. Theoretical considerations indicate that benzene stripping will be more difficult from the ITP unwashed high salt filtrates due to reduced mass transfer. Therefore experimental sparging data is needed to quantify the theoretical effects.Foaming limits which dictate allowable sparging rate will also have to be established. Sparging in the hold tanks will require installation of sintered metal spargers, and possibly stirrers and foam monitoring/disengagement equipment. The most critical sparging needs are at the start of the precipitation/concentration cycle, when the filtrate flux rate is the highest,and at the end of wash cycle where Henry`s equilibrium constant falls off,requiring more gas to sparge the dissolved benzene. With adequate recycle (for proper distribution) or sparging in the old tanks, the 30 inch column could be used for the complete ITP process. A courser packing would reduce back pressure while enabling benzene stripping. The Late Wash Tests indicate adequate benzene stripping even at reduced gas flow. This will require experimental verification under ITP conditions. Using the 30 in. column vs 18 in. during the wash cycle will enhance stripping without need for additional sparging provided the minimum flow requirements are met.

  12. Health benefits of particle filtration

    EPA Science Inventory

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

  13. CENTRIFUGES

    DOEpatents

    Beams, J.W.; Snoddy, L.B.

    1960-08-01

    Damping bearings for use on the shafts of an ultracentrifuge were designed which are capable of passing through critical angular speeds. The shaft extending from one end of the rotor is journaled in fixed-plain bearings mounted on annular resilient shock-absorbing elements to dampen small vibrations. The shaft at the other end of the rotor is journaled in two damper-bearing assemblies which are so spaced on the shaft that a vibration node can at no time exist at both bearing assemblies. These bearings are similar to the other bearings except that the bearing housings are slidably mounted on the supporting structure for movement transverse to the rotational axis of the rotor.

  14. Centrifugal separators and related devices and methods

    DOEpatents

    Meikrantz, David H [Idaho Falls, ID; Law, Jack D [Pocatello, ID; Garn, Troy G [Idaho Falls, ID; Macaluso, Lawrence L [Carson City, NV; Todd, Terry A [Aberdeen, ID

    2012-03-06

    Centrifugal separators and related methods and devices are described. More particularly, centrifugal separators comprising a first fluid supply fitting configured to deliver fluid into a longitudinal fluid passage of a rotor shaft and a second fluid supply fitting sized and configured to sealingly couple with the first fluid supply fitting are described. Also, centrifugal separator systems comprising a manifold having a drain fitting and a cleaning fluid supply fitting are described, wherein the manifold is coupled to a movable member of a support assembly. Additionally, methods of cleaning centrifugal separators are described.

  15. Filtration Understanding: FY10 Testing Results and Filtration Model Update

    SciTech Connect

    Daniel, Richard C.; Billing, Justin M.; Burns, Carolyn A.; Peterson, Reid A.; Russell, Renee L.; Schonewill, Philip P.; Shimskey, Rick W.

    2011-04-04

    This document completes the requirements of Milestone 2-4, Final Report of FY10 Testing, discussed in the scope of work outlined in the EM31 task plan WP-2.3.6-2010-1. The focus of task WP 2.3.6 is to improve the U.S. Department of Energy’s (DOE’s) understanding of filtration operations for high-level waste (HLW) to improve filtration and cleaning efficiencies, thereby increasing process throughput and reducing the Na demand (through acid neutralization). Developing the cleaning/backpulsing requirements will produce much more efficient operations for both the Hanford Tank Waste Treatment and Immobilization Plant (WTP) and the Savannah River Site (SRS), thereby significantly increasing throughput by limiting cleaning cycles. The scope of this work is to develop the understanding of filter fouling to allow developing this cleaning/backpulsing strategy.

  16. A critical evaluation of Amicon Ultra centrifugal filters for separating proteins, drugs and nanoparticles in biosamples.

    PubMed

    Johnsen, Elin; Brandtzaeg, Ole Kristian; Vehus, Tore; Roberg-Larsen, Hanne; Bogoeva, Vanya; Ademi, Ornela; Hildahl, Jon; Lundanes, Elsa; Wilson, Steven Ray

    2016-02-20

    Amicon(®) Ultra centrifugal filters were critically evaluated for various sample preparations, namely (a) proteome fractionation, (b) sample cleanup prior to liquid chromatography mass spectrometry (LC-MS) measurement of small molecules in cell lysate, and (c) separating drug-loaded nanoparticles and released drugs for accurate release profiling in biological samples. (a) Filters of supposedly differing molar mass (MM) selectivity (10, 30, 50 and 100K) were combined to attempt fractionation of samples of various complexity and concentration. However, the products had surprisingly similar MM retentate/filtrate profiles, and the filters were unsuited for proteome fractionation. (b) Centrifugal filtration was the only clean-up procedure in a FDA-guideline validated LC-MS method for determining anti-tuberculosis agents rifampicin and thioridazine in macrophage cell lysate. An additional organic solvent washing step (drug/protein-binding disruption) was required for satisfactory recovery. (c) The centrifugation filters are well suited for separating drugs and nanoparticles in simple aqueous solutions, but significantly less so for biological samples, as common drug-protein binding disruptors can dissolve NPs or be incompatible with LC-MS instrumentation.

  17. High Temperature Particle Filtration Technology

    SciTech Connect

    Besmann, T.M.

    2001-11-13

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

  18. Enrichment of high-quality spermatozoa in bovine semen: relative effectiveness of three filtration matrixes.

    PubMed

    Cisale, H O; Fischman, M L; Blasi, C D; Fernandez, H A; Gledhill, B L

    2001-05-01

    To be practical, any method for improving bull semen must yield a large quantity of motile spermatozoa. Some separation methods based on physical properties, e.g. filtration, chromatography, centrifugation, washing and pooling, have been reported as satisfactory, but generally are not repeatable. Nevertheless, filtration methods appear to allow the attainment of an acceptable number of spermatozoa, thus allowing such a technique to be introduced in the production of standard bovine semen doses for artificial insemination. The aim of this work was to evaluate systematically the relative effects of three filtration matrixes (silica oxide, glass beads or Sephadexätrade mark) on the improvement of whole ejaculate quality. Analysis of the type of matrix and the volume and height of the filtration column was performed. The only characteristic of the columns that appears to influence ejaculate quality after filtering is the matrix volume. While all matrixes produced improvement of semen quality, SephadexTM was better than the other matrixes tested. An explanation for the mechanism of column filtration is proposed.

  19. Apparatus for centrifugal separation of coal particles

    SciTech Connect

    Dickie, William; Cavallaro, Joseph A.; Killmeyer, Richard P.

    1991-01-01

    A gravimetric cell for centrifugal separation of fine coal by density has a cylindrical body and a butterfly valve or other apparatus for selectively sealing the body radially across the approximate center of the cylinder. A removable top is provided which seals the cylinder in the centrifuge and in unvented areas.

  20. Cake Filtration in Viscoelastic Polymer Solutions

    NASA Astrophysics Data System (ADS)

    Surý, Alexander; Machač, Ivan

    2009-07-01

    In this contribution, the filtration equations for a cake filtration in viscoelastic fluids are presented. They are based on a capillary hybrid model for the flow of a power law fluid. In order to express the elastic pressure drop excess in the flow of viscoelastic filtrate through the filter cake and filter screen, modified Deborah number correction functions are included into these equations. Their validity was examined experimentally. Filtration experiments with suspensions of hardened polystyrene particles (Krasten) in viscoelastic aqueous solutions of polyacryl amides (0.4% and 0.6%wt. Kerafloc) were carried out at a constant pressure on a cylindrical filtration unit using filter screens of different resistance.

  1. Relation Between Filtration and Soil Consolidation Theories

    NASA Astrophysics Data System (ADS)

    Strzelecki, Tomasz; Strzelecki, Michał

    2015-03-01

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

  2. Rotor for centrifugal fast analyzers

    DOEpatents

    Lee, N.E.

    1984-01-01

    The invention is an improved photometric analyzer of the rotary cuvette type, the analyzer incorporating a multicuvette rotor of novel design. The rotor (a) is leaktight, (b) permits operation in the 90/sup 0/ and 180/sup 0/ excitation modes, (c) is compatible with extensively used Centrifugal Fast Analyzers, and (d) can be used thousands of times. The rotor includes an assembly comprising a top plate, a bottom plate, and a central plate, the rim of the central plate being formed with circumferentially spaced indentations. A uv-transmitting ring is sealably affixed to the indented rim to define with the indentations an array of cuvettes. The ring serves both as a sealing means and an end window for the cuvettes.

  3. Rotor for centrifugal fast analyzers

    DOEpatents

    Lee, Norman E.

    1985-01-01

    The invention is an improved photometric analyzer of the rotary cuvette type, the analyzer incorporating a multicuvette rotor of novel design. The rotor (a) is leaktight, (b) permits operation in the 90.degree. and 180.degree. excitation modes, (c) is compatible with extensively used Centrifugal Fast Analyzers, and (d) can be used thousands of times. The rotor includes an assembly comprising a top plate, a bottom plate, and a central plate, the rim of the central plate being formed with circumferentially spaced indentations. A UV-transmitting ring is sealably affixed to the indented rim to define with the indentations an array of cuvettes. The ring serves both as a sealing means and an end window for the cuvettes.

  4. Centrifuges in gravitational physiology research

    NASA Technical Reports Server (NTRS)

    Ballard, Rodney W.; Davies, Phil; Fuller, Charles A.

    1993-01-01

    Data from space flight and ground based experiments have clearly demonstrated the importance of Earth gravity for normal physiological function in man and animals. Gravitational Physiology is concerned with the role and influence of gravity on physiological systems. Research in this field examines how we perceive and respond to gravity and the mechanisms underlying these responses. Inherent in our search for answers to these questions is the ability to alter gravity, which is not physically possible without leaving Earth. However, useful experimental paradigms have been to modify the perceived force of gravity by changing either the orientation of subjects to the gravity vector (i.e., postural changes) or by applying inertial forces to augment the magnitude of the gravity vector. The later technique has commonly been used by applying centripetal force via centrifugation.

  5. An Optimized Centrifugal Method for Separation of Semen from Superabsorbent Polymers for Forensic Analysis.

    PubMed

    Camarena, Lucy R; Glasscock, Bailey K; Daniels, Demi; Ackley, Nicolle; Sciarretta, Marybeth; Seashols-Williams, Sarah J

    2017-03-01

    Connection of a perpetrator to a sexual assault is best performed through the confirmed presence of semen, thereby proving sexual contact. Evidentiary items can include sanitary napkins or diapers containing superabsorbent polymers (SAPs), complicating spermatozoa visualization and DNA analysis. In this report, we evaluated the impact of SAPS on the current forensic DNA workflow, developing an efficient centrifugal protocol for separating spermatozoa from SAP material. The optimized filtration method was compared to common practices of excising the top layer only, resulting in significantly higher sperm yields when a core sample of the substrate was taken. Direct isolation of the SAP-containing materials without filtering resulted in 20% sample failure; additionally, SAP material was observed in the final eluted DNA samples, causing physical interference. Thus, use of the described centrifugal-filtering method is a simple preliminary step that improves spermatozoa visualization and enables more consistent DNA yields, while also avoiding SAP interference.

  6. Membrane solubility of chlorpromazine. Hygroscopic desorption and centrifugation methods yield comparable results.

    PubMed Central

    Luxnat, M; Müller, H J; Galla, H J

    1984-01-01

    Binding of the positively charged drug chlorpromazine to artificial and erythrocyte bilayer membranes was investigated by the filtration method called hygroscopic desorption [Conrad & Singer (1979) Proc. Natl. Acad. Sci. U.S.A. 76, 5202-5206] and by the conventional centrifugation method. Only minor differences in the partition coefficients were observed using the two methods. Our finding is not consistent with the observation of Conrad & Singer that amphipaths are completely excluded from biological membranes. However, the partition coefficient is dependent on membrane composition, which means dependent on the physical properties of a membrane. PMID:6525170

  7. Centrifuge workers study. Phase II, completion report

    SciTech Connect

    Wooten, H.D.

    1994-09-01

    Phase II of the Centrifuge Workers Study was a follow-up to the Phase I efforts. The Phase I results had indicated a higher risk than expected among centrifuge workers for developing bladder cancer when compared with the risk in the general population for developing this same type of cancer. However, no specific agent could be identified as the causative agent for these bladder cancers. As the Phase II Report states, Phase I had been limited to workers who had the greatest potential for exposure to substances used in the centrifuge process. Phase II was designed to expand the survey to evaluate the health of all employees who had ever worked in Centrifuge Program Departments 1330-1339 but who had not been interviewed in Phase I. Employees in analytical laboratories and maintenance departments who provided support services for the Centrifuge Program were also included in Phase II. In December 1989, the Oak Ridge Associated Universities (ORAU), now known as Oak Ridge Institute for Science and Education (ORISE), was contracted to conduct a follow-up study (Phase II). Phase H of the Centrifuge Workers Study expanded the survey to include all former centrifuge workers who were not included in Phase I. ORISE was chosen because they had performed the Phase I tasks and summarized the corresponding survey data therefrom.

  8. Microwave Digestion--Vacuum Filtration-Automated Scanning Electron Microscopy as a sensitive method for forensic diatom test.

    PubMed

    Zhao, Jian; Liu, Chao; Hu, Sunlin; He, Shuwen; Lu, Siya

    2013-03-01

    Diagnosis of drowning is one of the most difficult issues in forensic practice. A number of methods have been developed over the years to determine whether a person was drowned. Microwave Digestion-Vacuum Filtration-Automated Scanning Electron Microscopy (MD-VF-Auto SEM) method we developed is a new qualitative and quantitative method of diatom test for diagnosis of drowning. The new method is based on microwave digestion technique, vacuum filtration, and automated SEM, which would achieve a maximal recovery of diatoms and identify diatoms easily by SEM with high resolution. This study was designed to evaluate the sensitivity of this method, the recovery of diatom, and loss ratio of centrifugation, which were compared using the MD-VF-Auto SEM method and the conventional acid digestion method. Two groups of samples were designed in the study. Groups A (n = 20) and B (n = 20) were performed by MD-VF-Auto SEM method and the conventional acid digestion method, respectively. In addition, another eight water samples were centrifuged, and the diatoms in the supernatant and precipitate were counted and measured, respectively, in order to find out how many diatoms were lost after centrifugation. The difference between the two groups was statistically highly significant, and about 34 % of diatoms were lost after centrifugation at 4,000 rpm for 15 min. The results showed that the MD-VF-Auto SEM method was more sensitive and specific.

  9. Water Filtration Using Plant Xylem

    PubMed Central

    Chambers, Valerie; Venkatesh, Varsha; Karnik, Rohit

    2014-01-01

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

  10. Sioux City Riverbank Filtration Study

    NASA Astrophysics Data System (ADS)

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

    2003-04-01

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

  11. Gas dynamics in strong centrifugal fields

    SciTech Connect

    Bogovalov, S.V.; Kislov, V.A.; Tronin, I.V.

    2015-03-10

    Dynamics of waves generated by scopes in gas centrifuges (GC) for isotope separation is considered. The centrifugal acceleration in the GC reaches values of the order of 106g. The centrifugal and Coriolis forces modify essentially the conventional sound waves. Three families of the waves with different polarisation and dispersion exist in these conditions. Dynamics of the flow in the model GC Iguasu is investigated numerically. Comparison of the results of the numerical modelling of the wave dynamics with the analytical predictions is performed. New phenomena of the resonances in the GC is found. The resonances occur for the waves polarized along the rotational axis having the smallest dumping due to the viscosity.

  12. Pig manure treatment and purification by filtration.

    PubMed

    Makara, A; Kowalski, Z

    2015-09-15

    This study aimed to develop a new, complex pig manure treatment and filtration process. The final scheme, called the AMAK process, comprised the following successive steps: mineralization with mineral acids, alkalization with lime milk, superphosphate addition, a second alkalization, thermal treatment, and pressure filtration. The proposed method produced a filtrate with 95%, 80%, and 96% reductions in chemical oxygen demand, nitrogen content, and phosphorus content, respectively. An advantage of the proposed method was that it incorporated a crystalline phase into the solid organic part of the manure, which enabled high filtration rates (>1000 kg m(-2) h(-1)) and efficient separation. The process also eliminated odor emissions from the filtrate and sediment. The treated filtrate could be used to irrigate crops or it could be further treated in conventional biological wastewater treatment plants. The sediment could be used for producing mineral-organic fertilizer. The AMAK process is inexpensive, and it requires low investment costs.

  13. Membrane filtration of food suspensions.

    PubMed Central

    Sharpe, A N; Peterkin, P I; Dudas, I

    1979-01-01

    Factors affecting the membrane filtration of food suspensions were studied for 58 foods and 13 membrane filters. Lot number within a brand, pore size (0.45 or 0.8 micrometer), and time elapsed before filtration had little effect on filterability. Brand of membrane filter, flow direction, pressure differential, age (microbiological quality) of the food, duration of the blending process, temperature, and concentration of food in the suspension had significant and often predictable effects. Preparation of suspensions by Stomacher (relative to rotary blender) addition of surfactant (particularly at elevated temperature) and prior incubation with proteases sometimes had dramatic effects of filterability. In contrast to popular opinion, foods can be membrane filtered in quantities pertinent to the maximums used in conventional plating procedures. Removal of growth inhibitors and food debris is possible by using membrane filters. Lowering of the limits of detection of microorganisms by concentration on membrane filters can be considered feasible for many foods. The data are particularly relevant to the use of hydrophobic grid-membrane filters (which are capable of enumerating up to 9 X 10(4) organisms per filter) in instrumented methods of food microbiological analysis. Images PMID:760637

  14. Modeling of Centrifugal Force Field and the Effect on Filling and Solidification in Centrifugal Casting

    NASA Astrophysics Data System (ADS)

    Sheng, Wenbin; Ma, Chunxue; Gu, Wanli

    2011-06-01

    Based on the steady flow in a tube, a mathematical model has been established for the consideration of centrifuging force field by combining the equations of continuity, conservation of momentum and general energy. Effects of centrifugal field on the filling and solidification are modeled by two accessional terms: centrifugal force and Chorios force. In addition, the transfer of heat by convection is considered to achieve a coupling calculation of velocity field and temperature field. The solution of pressure item is avoided by introducing the stream function ψ(x,y) and the eddy function ξ(x,y). Corresponding difference formats for the simultaneous equations of centrifugal filling, the accessional terms and the solidifying latent heat have been established by the finite difference technique. Furthermore, the centrifugal filling and solidification processes in a horizontal tube are summarized to interpret the mechanism by which internal defects are formed in centrifugal castings.

  15. Side Stream Filtration for Cooling Towers

    SciTech Connect

    2012-10-20

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

  16. Nonwoven filtration mat production by electrospinning method

    NASA Astrophysics Data System (ADS)

    Lackowski, M.; Krupa, A.; Jaworek, A.

    2011-06-01

    The filtration of nanoparticles and submicron particles is an important problem in industry and health protection. One of the methods which can be used to solve this problem is to use nonwoven nanofibrous filters. The process of producing filtration mats of different thickness by electrospinning is presented in the paper. The experimental results on filtration properties of nanofibrous filter mat, including the efficiency of removal of cigarette smoke particles from a gas are also presented.

  17. Metabolomics sampling of Pichia pastoris revisited: rapid filtration prevents metabolite loss during quenching.

    PubMed

    Russmayer, Hannes; Troyer, Christina; Neubauer, Stefan; Steiger, Matthias G; Gasser, Brigitte; Hann, Stephan; Koellensperger, Gunda; Sauer, Michael; Mattanovich, Diethard

    2015-09-01

    Metabolomics can be defined as the quantitative assessment of a large number of metabolites of a biological system. A prerequisite for the accurate determination of intracellular metabolite concentrations is a reliable and reproducible sample preparation method, which needs to be optimized for each organism individually. Here, we compare the performance of rapid filtration and centrifugation after quenching of Pichia pastoris cells in cold methanol. During incubation in the quenching solution, metabolites are lost from the cells with a half-life of 70-180 min. Metabolites with lower molecular weights showed lower half-lifes compared to metabolites with higher molecular weight. Rapid filtration within 2 min after quenching leads to only minor losses below 2%, and is thus the preferred method for cell separation.

  18. Gas centrifuge with driving motor

    DOEpatents

    Dancy, Jr., William H.

    1976-01-01

    1. A centrifuge for separating gaseous constituents of different masses comprising a vertical tubular rotor, means for introducing a gas mixture of different masses into said rotor and means for removing at least one of the gas components from the rotor, a first bearing means supporting said rotor at one end for rotational movement, a support, a damping bearing mounted on said support, a shaft fixed to said rotor at the opposite end and mechanically connecting said rotor to said damping bearing, a cup-shaped tube of electrically conductive, non-magnetic material in coaxial relationship with said shaft, the open end of said tube extending away from said rotor and the closed end of said tube being directly secured to the adjacent end of the rotor, an annular core of magnetic material fixedly mounted on said support so as to be disposed within said tube and around said shaft, and a second annular magnetic core with coils arranged thereon to receive polyphase current to produce a rotating magnetic field traversing the circumference of said tube, fixedly mounted on said support so as to surround said tube, the size of said first annular core and said second annular core being such as to permit limited radial displacement of said shaft and said tube.

  19. Two-Stage Centrifugal Fan

    NASA Technical Reports Server (NTRS)

    Converse, David

    2011-01-01

    Fan designs are often constrained by envelope, rotational speed, weight, and power. Aerodynamic performance and motor electrical performance are heavily influenced by rotational speed. The fan used in this work is at a practical limit for rotational speed due to motor performance characteristics, and there is no more space available in the packaging for a larger fan. The pressure rise requirements keep growing. The way to ordinarily accommodate a higher DP is to spin faster or grow the fan rotor diameter. The invention is to put two radially oriented stages on a single disk. Flow enters the first stage from the center; energy is imparted to the flow in the first stage blades, the flow is redirected some amount opposite to the direction of rotation in the fixed stators, and more energy is imparted to the flow in the second- stage blades. Without increasing either rotational speed or disk diameter, it is believed that as much as 50 percent more DP can be achieved with this design than with an ordinary, single-stage centrifugal design. This invention is useful primarily for fans having relatively low flow rates with relatively high pressure rise requirements.

  20. Persistent homology in graph power filtrations

    PubMed Central

    Marchette, David J.

    2016-01-01

    The persistence of homological features in simplicial complex representations of big datasets in Rn resulting from Vietoris–Rips or Čech filtrations is commonly used to probe the topological structure of such datasets. In this paper, the notion of homological persistence in simplicial complexes obtained from power filtrations of graphs is introduced. Specifically, the rth complex, r ≥ 1, in such a power filtration is the clique complex of the rth power Gr of a simple graph G. Because the graph distance in G is the relevant proximity parameter, unlike a Euclidean filtration of a dataset where regional scale differences can be an issue, persistence in power filtrations provides a scale-free insight into the topology of G. It is shown that for a power filtration of G, the girth of G defines an r range over which the homology of the complexes in the filtration are guaranteed to persist in all dimensions. The role of chordal graphs as trivial homology delimiters in power filtrations is also discussed and the related notions of ‘persistent triviality’, ‘transient noise’ and ‘persistent periodicity’ in power filtrations are introduced. PMID:27853540

  1. Filtration Behaviour and Fouling Mechanisms of Polysaccharides

    PubMed Central

    Jamal, Sondus; Chang, Sheng; Zhou, Hongde

    2014-01-01

    This study investigated filtration behaviors of polysaccharides solutions, both alone and in mixture with proteins, in the short-time constant flux filtration with the focus on factors affecting the transmembrane pressure (TMP) increase rate, the irreversible filtration resistance, and the membrane rejection behavior. The results showed that the TMP increase rates in the short-time constant flux filtration of alginate solutions were significantly affected by the calcium addition, alginate concentration, and flux. Although the addition of calcium resulted in a decrease in the TMP increase rate, it was found that the irreversible fouling developed during the filtration increased with the calcium addition, implying that the double-sided effect of calcium on membrane filtration and that the TMP increase rate observed in the filtration does not always reflect the irreversible membrane fouling development. It was also found that for the filtration of solutions containing mixed alginate and BSA, alginate exerted a dominant effect on the TMP increase rate and the membrane exhibited a reduced rejection to both alginate and BSA molecules compared to that in the filtration of the pure alginate or BSA. PMID:25007243

  2. Optical detection strategies for centrifugal microfluidic platforms

    NASA Astrophysics Data System (ADS)

    King, Damien; O'Sullivan, Mary; Ducrée, Jens

    2014-01-01

    Centrifugal microfluidic systems have become one of the principal platforms for implementing bioanalytical assays, most notably for biomedical point-of-care diagnostics. These so-called 'lab-on-a-disc' systems primarily utilise the rotationally controlled centrifugal field in combination with capillary forces to automate a range of laboratory unit operations (LUOs) for sample preparation, such as metering, aliquoting, mixing and extraction for biofluids as well as sorting, isolation and counting of bioparticles. These centrifugal microfluidic LUOs have been regularly surveyed in the literature. However, even though absolutely essential to provide true sample-to-answer functionality of lab-on-a-disc platforms, systematic examination of associated, often optical, read-out technologies has been so far neglected. This review focusses on the history and state-of-the-art of optical read-out strategies for centrifugal microfluidic platforms, arising (commercial) application potential and future opportunities.

  3. Combination Of Investment And Centrifugal Casting

    NASA Technical Reports Server (NTRS)

    Creeger, Gordon A.

    1994-01-01

    Modifications, including incorporation of centrifugal casting, made in investment-casting process reducing scrap rate. Used to make first- and second-stage high-pressure-fuel-turbopump nozzles, containing vanes with thin trailing edges and other thin sections. Investment mold spun for short time while being filled, and stopped before solidification occurs. Centrifugal force drives molten metal into thin trailing edges, ensuring they are filled. With improved filling, preheat and pour temperatures reduced and solidification hastened so less hot tearing.

  4. Renal Response to Chronic Centrifugation in Rats

    NASA Technical Reports Server (NTRS)

    Ortiz, Rudy M.; Wang, T. J.; Corbin, B. J.; Wade, C. E.; Hargens, Alan R. (Technical Monitor)

    1996-01-01

    Previously reported effects of chronic centrifugation on renal function in mammals are contradictory. The present study was conducted as an effort to provide a comprehensive analysis of renal response to chronic centrifugation (12 days at +2 Gz). Sixteen male Sprague-Dawley rats (210-230 g) were used: eight centrifuged (EC) and eight off centrifuge controls (OCC). During centrifugation EC had lower body weight and food consumption. EC showed a decrease (72%) in water intake for the first two days (T1 and T2) followed by significant increases from T4-T6. EC urine output increased two-fold over the first four days, returning to baseline by T9. EC urea excretion was elevated on T3 through T5. Creatinine, Na(+), K(+), and osmolar excretion were lower than OCC over the last four days of the study. Assuming constant plasma osmolarity and creatinine levels, EC free water clearance (C(sub H2O)) was elevated significantly on T4 when the peak urine output was exhibited. EC also had a greater C(sub H2O) over the last four days, associated with a significantly lower osmolar clearance and GFR. The initial diuresis exhibited during centrifugation can be attributed to a reduced water resorption and increased urea excretion. This diuresis was mediated independent of changes in GFR over the first eight days. However, differences in excretion seen after eight days of centrifugation are probably GFR mediated which would imply animals established a new homeostatic setpoint by that time. Centrifugation elicites an acute alteration in fluid homeostasis followed by adaptation within a week.

  5. Tangential flow filtration of hemoglobin.

    PubMed

    Palmer, Andre F; Sun, Guoyong; Harris, David R

    2009-01-01

    Bovine and human hemoglobin (bHb and hHb, respectively) was purified from bovine and human red blood cells via tangential flow filtration (TFF) in four successive stages. TFF is a fast and simple method to purify Hb from RBCs using filtration through hollow fiber (HF) membranes. Most of the Hb was retained in stage III (100 kDa HF membrane) and displayed methemoglobin levels less than 1%, yielding final concentrations of 318 and 300 mg/mL for bHb and hHb, respectively. Purified Hb exhibited much lower endotoxin levels than their respective RBCs. The purity of Hb was initially assessed via SDS-PAGE, and showed tiny impurity bands for the stage III retentate. The oxygen affinity (P(50)) and cooperativity coefficient (n) were regressed from the measured oxygen-RBC/Hb equilibrium curves of RBCs and purified Hb. These results suggest that TFF yielded oxygen affinities of bHb and hHb that are comparable to values in the literature. LC-MS was used to measure the molecular weight of the alpha (alpha) and beta (beta) globin chains of purified Hb. No impurity peaks were present in the HPLC chromatograms of purified Hb. The mass of the molecular ions corresponding to the alpha and beta globin chains agreed well with the calculated theoretical mass of the alpha- and beta- globin chains. Taken together, our results demonstrate that HPLC-grade Hb can be generated via TFF. In general, this method can be more broadly applied to purify Hb from any source of RBCs. This work is significant, since it outlines a simple method for generating Hb for synthesis and/or formulation of Hb-based oxygen carriers.

  6. Development of a virus concentration method using lanthanum-based chemical flocculation coupled with modified membrane filtration procedures.

    PubMed

    Zhang, Yanyan; Riley, Lela K; Lin, Mengshi; Purdy, Gregory A; Hu, Zhiqiang

    2013-06-01

    Direct membrane filtration is often used to concentrate viruses in water but it may suffer from severe membrane fouling and clogging. Here, a lanthanum-based flocculation method coupled with modified membrane filtration procedures was developed and evaluated to detect viruses in large volume (40 L) water samples. The lanthanum-based flocculation method could easily reduce the water sample volume by a factor of 40. Additional volume reduction was achieved by a two-step membrane filtration approach. First, selected membrane filters (including 1MDS electropositive filters and nitrocellulose electronegative filters-Millipore HATF filters) were used to reduce water sample volume further and compare their efficiencies in virus recovery. The Mg²⁺-modified HATF membrane performed better on MS2 retention with an average virus recovery of 83.4% (±4.5% [standard deviation]). After HATF membrane filtration and elution, centrifugal ultrafiltration through a 30 kDa cut-off membrane resulted in an overall concentration factor of 20,000. Results from the infectivity assay showed that the MS2 recovery efficiencies from the NanoCeram- and 1MDS-based direct filtration and the lanthanum-based concentration coupled with the modified filtration procedure were 10.1% (±1.0%), 3.3% (±0.1%), and 17.5% (±1.1%), respectively. Results from the PCR analysis showed that the virus recoveries of the lanthanum-based method were 20.6% (±2.9%) and 19.5% (±3.4%) for MS2 and adenovirus, respectively, while no adenovirus could be detected through the NanoCeram- and 1MDS-based direct filtration. The lanthanum-based concentration method coupled with modified membrane filtration procedures is therefore a promising method for detecting waterborne viruses.

  7. Microfluidic filtration system to isolate extracellular vesicles from blood.

    PubMed

    Davies, Ryan T; Kim, Junho; Jang, Su Chul; Choi, Eun-Jeong; Gho, Yong Song; Park, Jaesung

    2012-12-21

    Extracellular vesicles are released by various cell types, particularly tumor cells, and may be potential targets for blood-based cancer diagnosis. However, studies performed on blood-borne vesicles to date have been limited by lack of effective, standardized purification strategies. Using in situ prepared nanoporous membranes, we present a simple strategy employing a microfluidic filtration system to isolate vesicles from whole blood samples. This method can be applied to purify nano-sized particles from blood allowing isolation of intact extracellular vesicles, avoiding the need for laborious and potentially damaging centrifugation steps or overly specific antibody-based affinity purification. Porous polymer monoliths were integrated as membranes into poly(methyl methacrylate) microfluidic chips by benchtop UV photopolymerization through a mask, allowing precise positioning of membrane elements while preserving simplicity of device preparation. Pore size could be manipulated by changing the ratio of porogenic solvent to prepolymer solution, and was tuned to a size proper for extraction of vesicles. Using the membrane as a size exclusion filter, we separated vesicles from cells and large debris by injecting whole blood under pressure through the microfluidic device. To enhance isolation purity, DC electrophoresis was employed as an alternative driving force to propel particles across the filter and increase the separation efficiency of vesicles from proteins. From the whole blood of melanoma-grown mice, we isolated extracellular vesicles and performed RT-PCR to verify their contents of RNA. Melan A mRNA derived from melanoma tumor cells were found enriched in filtered samples, confirming the recovery of vesicles via their cargo. This filtration system can be incorporated into other on-chip processes enabling integrated sample preparation for the downstream analysis of blood-based extracellular vesicles.

  8. MHD Stability of Centrifugally Confined Plasmas

    NASA Astrophysics Data System (ADS)

    Huang, Yi-Min

    2003-10-01

    Centrifugally confined plasmas utilize centrifugal forces from plasma rotation to augment magnetic confinement, as an alternative approach to fusion. One magnetic geometry is mirror-type, with rotation about the axis induced from a central, biased core conductor. The outward centrifugal forces from the rotation have a component along the field lines, thus confining ions to the center. The immediate concern, of course, is that the system could be flute unstable to the interchange. The antidote here is that the radial shear in the rotation could stabilize the flute. Our 2D simulations show, first, that plasma pressure is highly peaked at the center away from the mirror end coils. Next, 3D simulations show unequivocally that velocity shear is providing the stability. Further study indicates that the flute stability is sensitive to the density profile. A favorable density profile could be achieved by judiciously placing the particle source, also necessary for a steady state centrifuge. As flows approach the Alfven speed, electromagnetic modes could be involved. The latter is motivated by the question of whether magnetorotational instability, thought to be an angular momentum transporter in accretion disks, could be found in centrifugal plasmas, since all the ingredients are there. We show that the MRI as understood should be stable; however, a related astrophysical instability, the Parker instability, could arise. The Parker instability results in plasma accumulating in regions of bent field lines, further accentuating the bending.

  9. Centrifugal techniques for measuring saturated hydraulic conductivity

    USGS Publications Warehouse

    Nimmo, John R.; Mello, Karen A.

    1991-01-01

    Centrifugal force is an alternative to large pressure gradients for the measurement of low values of saturated hydraulic conductivity (Ksat). With a head of water above a porous medium in a centrifuge bucket, both constant-head and falling-head measurements are practical at forces up to at least 1800 times normal gravity. Darcy's law applied to the known centrifugal potential leads to simple formulas for Ksat that are analogous to those used in the standard gravity-driven constant- and falling-head methods. Both centrifugal methods were tested on several fine-textured samples of soil and ceramic with Ksat between about 10−10 and 10−9 m/s. The results were compared to falling-head gravity measurements. The comparison shows most measurements agreeing to within 20% for a given sample, much of the variation probably resulting from run-to-run changes in sample structure. The falling-head centrifuge method proved to be especially simple in design and operation and was more accurate than the constant-head method. With modified apparatus, Ksat measurements less than 10−10 m/s should be attainable.

  10. Liquid centrifugation for nuclear waste partitioning

    SciTech Connect

    Bowman, C.D.

    1992-03-11

    The performance of liquid centrifugation for nuclear waste partitioning is examined for the Accelerator Transmutation of Waste Program currently under study at the Los Alamos National Laboratory. Centrifugation might have application for the separation of the LiF-BeF{sub 2} salt from heavier radioactive materials fission product and actinides in the separation of fission product from actinides, in the isotope separation of fission-product cesium before transmutation of the {sup 137}Cs and {sup 135}Cs, and in the removal of spallation product from the liquid lead target. It is found that useful chemical separations should be possible using existing materials for the centrifuge construction for all four cases with the actinide fraction in fission product perhaps as low as 1 part in 10{sup 7} and the fraction of {sup 137}CS in {sup 133}Cs being as low as a few parts in 10{sup 5}. A centrifuge cascade has the advantage that it can be assembled and operated as a completely closed system without a waste stream except that associated with maintenance or replacement of centrifuge components.

  11. The Use of a "Qual" Centrifuge for Greatly Simplifying and Speeding the Study of Milk

    NASA Astrophysics Data System (ADS)

    Petersen, Quentin R.

    1996-09-01

    Laboratory study of the constituents of milk is almost always slowed by difficult separation of relatively large amounts of curd and whey by filtration. In the two-and-one-half hour experiment described, only 5 mL of skim milk is used and the curd is separated from the whey by using a simple "qual" centrifuge. Casein and serum proteins are quickly isolated as solids in essentially-quantitative yields in a procedure utilizing only two 13 x 100 mm test tubes and a 50 mL beaker along with the centrifuge and a hotplate. Protein solutions are prepared in the test tubes in which they were isolated and subjected to a variety of classical tests, the most dramatic of which is the Hopkins-Cole test which shows the presence of tryptophan in casein and its absence in serum protein. An essentially-quantitative yield of solid lactose is obtained by evaporation of the supernatant liquid obtained from the serum protein centrifugation. A lactose solution is subjected to Benedict's and Barfoed's tests, identifying it as a disaccharide. Sufficient time is available to compare the fat and enzyme contents of raw milk and skim milk.

  12. 8. Detail view of southwest corner of filtration bed building. ...

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

    8. Detail view of southwest corner of filtration bed building. - Lake Whitney Water Filtration Plant, Filtration Plant, South side of Armory Street between Edgehill Road & Whitney Avenue, Hamden, New Haven County, CT

  13. 12. View west of access bridge to top of filtration ...

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

    12. View west of access bridge to top of filtration bed building. - Lake Whitney Water Filtration Plant, Filtration Plant, South side of Armory Street between Edgehill Road & Whitney Avenue, Hamden, New Haven County, CT

  14. 11. View of east entry to central corridor of filtration ...

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

    11. View of east entry to central corridor of filtration bed building. - Lake Whitney Water Filtration Plant, Filtration Plant, South side of Armory Street between Edgehill Road & Whitney Avenue, Hamden, New Haven County, CT

  15. 32. Piping under central corridor of filtration bed building. ...

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

    32. Piping under central corridor of filtration bed building. - Lake Whitney Water Filtration Plant, Filtration Plant, South side of Armory Street between Edgehill Road & Whitney Avenue, Hamden, New Haven County, CT

  16. 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

  17. 4. View south of rear of filtration bed building. ...

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

    4. View south of rear of filtration bed building. - Lake Whitney Water Filtration Plant, Filtration Plant, South side of Armory Street between Edgehill Road & Whitney Avenue, Hamden, New Haven County, CT

  18. 14. View of damage to southeast corner of filtration building. ...

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

    14. View of damage to southeast corner of filtration building. Note construction of concrete over brick. - Lake Whitney Water Filtration Plant, Filtration Plant, South side of Armory Street between Edgehill Road & Whitney Avenue, Hamden, New Haven County, CT

  19. 31. Piping under central corridor of filtration bed building. ...

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

    31. Piping under central corridor of filtration bed building. - Lake Whitney Water Filtration Plant, Filtration Plant, South side of Armory Street between Edgehill Road & Whitney Avenue, Hamden, New Haven County, CT

  20. 13. View of west entrance to central corridor of filtration ...

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

    13. View of west entrance to central corridor of filtration bed building. - Lake Whitney Water Filtration Plant, Filtration Plant, South side of Armory Street between Edgehill Road & Whitney Avenue, Hamden, New Haven County, CT

  1. 7. View east of southeast corner of filtration bed building. ...

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

    7. View east of southeast corner of filtration bed building. Laboratory building is at center left of photograph. - Lake Whitney Water Filtration Plant, Filtration Plant, South side of Armory Street between Edgehill Road & Whitney Avenue, Hamden, New Haven County, CT

  2. Reduced quenching and extraction time for mammalian cells using filtration and syringe extraction.

    PubMed

    Hernández Bort, Juan A; Shanmukam, Vinoth; Pabst, Martin; Windwarder, Markus; Neumann, Laura; Alchalabi, Ali; Krebiehl, Guido; Koellensperger, Gunda; Hann, Stephan; Sonntag, Denise; Altmann, Friedrich; Heel, Christine; Borth, Nicole

    2014-07-20

    In order to preserve the in vivo metabolite levels of cells, a quenching protocol must be quickly executed to avoid degradation of labile metabolites either chemically or biologically. In the case of mammalian cell cultures cultivated in complex media, a wash step previous to quenching is necessary to avoid contamination of the cell pellet with extracellular metabolites, which could distort the real intracellular concentration of metabolites. This is typically achieved either by one or multiple centrifugation/wash steps which delay the time until quenching (even harsh centrifugation requires several minutes for processing until the cells are quenched) or filtration. In this article, we describe and evaluate a two-step optimized protocol based on fast filtration by use of a vacuum pump for quenching and subsequent extraction of intracellular metabolites from CHO (Chinese hamster ovary) suspension cells, which uses commercially available components. The method allows transfer of washed cells into liquid nitrogen within 10-15s of sampling and recovers the entire extraction solution volume. It also has the advantage to remove residual filter filaments in the final sample, thus preventing damage to separation columns during subsequent MS analysis. Relative to other methods currently used in the literature, the resulting energy charge of intracellular adenosine nucleotides was increased to 0.94 compared to 0.90 with cold PBS quenching or 0.82 with cold methanol/AMBIC quenching.

  3. PDF-based heterogeneous multiscale filtration model.

    PubMed

    Gong, Jian; Rutland, Christopher J

    2015-04-21

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

  4. Filtrating forms of soil bacteria

    NASA Astrophysics Data System (ADS)

    Van'kova, A. A.; Ivanov, P. I.; Emtsev, V. T.

    2013-03-01

    Filtrating (ultramicroscopic) forms (FF) of bacteria were studied in a soddy-podzolic soil and the root zone of alfalfa plants as part of populations of the most widespread physiological groups of soil bacteria. FF were obtained by filtering soil solutions through membrane filters with a pore diameter of 0.22 μm. It was established that the greater part of the bacteria in the soil and in the root zone of the plants has an ultramicroscopic size: the average diameter of the cells is 0.3 μm, and their length is 0.6 μm, which is significantly less than the cell size of banal bacteria. The number of FF varies within a wide range depending on the physicochemical conditions of the habitat. The FF number's dynamics in the soil is of a seasonal nature; i.e., the number of bacteria found increases in the summer and fall and decreases in the winter-spring period. In the rhizosphere of the alfalfa, over the vegetation period, the number of FF and their fraction in the total mass of the bacteria increase. A reverse tendency is observed in the rhizoplane. The morphological particularities (identified by an electron microscopy) and the nature of the FF indicate their physiological activity.

  5. Effects of chronic centrifugation on mice

    NASA Technical Reports Server (NTRS)

    Janer, L.; Duke, J.

    1984-01-01

    Previous studies have shown that exposure to excess gravity in vitro alters the developmental sequence in embryonic mouse limbs and palates (Duke, Janer and Campbell, 1984; Duke, 1983). The effects of excess gravity on in vivo mammalian development was investigated using a small animal centrifuge. Four-week old female mice exposed to excess gravities of 1.8-3.5 G for eight weeks weighed significantly less than controls. Mice were mated after five weeks of adaptation to excess G, and sacrificed either at gestational day 12 or 18. There were fewer pregnancies in the centrifuged group (4/36) than in controls (9/31), and crown rump lengths (CRL) of embryos developing in the centrifuge were less than CRLs of 1-G embryos. These results show that although immersed in amniotic fluid, embryos are responsive to Delta-G.

  6. Possible segregation caused by centrifugal titanium casting.

    PubMed

    Watanabe, K; Okawa, S; Kanatani, M; Nakano, S; Miyakawa, O; Kobayashi, M

    1996-12-01

    The possibility of the segregation under solidification process using a centrifugal casting machine was investigated using an electron probe microanalyzer with elemental distribution map, line analysis and quantitative analysis. When a very small quantity of platinum was added to local molten titanium during the casting process, macroscopic segregation was observed under conditions of density difference of 0.1 g/cm3 at the most, confirming that the centrifugal force of the casting machine is extremely strong. When a Ti-6Al-4V alloy was cast, however, no macroscopic segregation was observed. The centrifugal force of the casting machine examined in the present study hardly results in the body-force segregation in this titanium alloy.

  7. 26. RW Meyer Sugar Mill: 18761889. Centrifugals, 1879, 1881. Manufacturer, ...

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

    26. RW Meyer Sugar Mill: 1876-1889. Centrifugals, 1879, 1881. Manufacturer, unknown. Supplied by Honolulu Ironworks, Honolulu, Hawaii, 1879, 1881. View: Historical view, 1934, from T. T. Waterman collection, Hawaiian Sugar Planters' Association. Once the molasses was separated from the sugar crystals it flowed through the spouts in the base of the centrifugals. The centrifugals' pulleys can be seen underneath the centrifugal. The centrifugal on the right has been reinforced with seven metal bands. The handles for the clutch mechanism are located above the centrifugal. - R. W. Meyer Sugar Mill, State Route 47, Kualapuu, Maui County, HI

  8. Plankton filtration with compressible crumb rubber packs.

    PubMed

    Karanikola, Vasiliki; Ngo, Anh T; Valdes, Julio R

    2011-01-01

    The experiments described provide insight into the feasibility of using compressible particulate packs to filter live plankton. The pore constriction sizes are controlled by subjecting the filter pack to isotropic confinement, thereby allowing for: (1) enhanced filtration upon confinement and (2) enhanced unclogging upon relaxation. Results show that filtration efficiency increases with increasing confinement; however, complete plankton retention is difficult to attain due to the plankton's ability to pass through pore constrictions that are smaller than the plankton size. The results are anticipated to offer potential benefits to ballast treatment and aquatic filtration operations.

  9. Effects of Centrifuge Diameter and Operation on Rodent Adaptation to Chronic Centrifugation

    NASA Technical Reports Server (NTRS)

    Fuller, Charles A.

    1992-01-01

    This study examined the responses of rats to centrifugation in a constant acceleration field (1.5 G). Centrifuge diameter (1.8m, 2.5m or 6.0m) and schedule of operation (Daily or weekly stop) varied between groups. Body mass, food consumption, water consumption and neurovestibular function were measured weekly. Body temperature and activity were continuously monitored using telemetry. A subset of subjects were videotaped (50 minutes per day) to allow for movement analysis. Exposure to a hyperdynamic field of this magnitude did cause the expected depression in the physiological variables monitored. Recovery was accomplished within a relatively rapid time frame; all variables returned to precentrifugation levels. In general, the magnitudes of the changes and the rate of recovery were similar at different centrifuge diameters and stopping frequency. There were cases, however, in which the magnitude of the response and/or the rate of recovery to a new steady-state were altered as a result of centrifuge diameter. In summary, these results indicate that stopping frequency has little, if any, effect on adaptation to chronic centrifugation. However, the angular velocity (omega), and therefore centrifuge diameter is an important consideration in the adaptation of an organism to chronic centrifugation.

  10. Effects of Centrifuge Diameter and Operation on Rodent Adaptation to Chronic Centrifugation

    NASA Technical Reports Server (NTRS)

    Fuller, Charles A.

    1997-01-01

    This study examined the responses of rats to centrifugation in a constant acceleration field (1.5 G). Centrifuge diameter (1.8m, 2.5m or 6.0m) and schedule of operation (Daily or weekly stop) varied between groups. Body mass, food consumption, water consumption and neurovestibular function were measured weekly. Body temperature and activity were continuously monitored using telemetry. A subset of subjects were videotaped (50 minutes per day) to allow for movement analysis. Exposure to a hyperdynamic field of this magnitude did cause the expected depression in the physiological variables monitored. Recovery was accomplished within a relatively rapid time frame; all variables returned to precentrifugation levels. In general, the magnitudes of the changes and the rate of recovery were similar at different centrifuge diameters and stopping frequency. There were cases, however, in which the magnitude of the response and/or the rate of recovery to a new steady-state were altered as a result of centrifuge diameter. In summary, these results indicate that stopping frequency has little, if any, effect on adaptation to chronic centrifugation. However, the angular velocity (omega), and therefore centrifuge diameter is an important consideration in the adaptation of an organism to chronic centrifugation.

  11. Detection methods for centrifugal microfluidic platforms.

    PubMed

    Burger, Robert; Amato, Letizia; Boisen, Anja

    2016-02-15

    Centrifugal microfluidics has attracted much interest from academia as well as industry, since it potentially offers solutions for affordable, user-friendly and portable biosensing. A wide range of so-called fluidic unit operations, e.g. mixing, metering, liquid routing, and particle separation, have been developed and allow automation and integration of complex assay protocols in lab-on-a-disc systems. Besides liquid handling, the detection strategy for reading out the assay is crucial for developing a fully integrated system. In this review, we focus on biosensors and readout methods for the centrifugal microfluidics platform and cover optical as well as mechanical and electrical detection principles.

  12. Wave-Driven Rotation In Centrifugal Mirrors

    SciTech Connect

    Abraham J. Fetterman and Nathaniel J. Fisch

    2011-03-28

    Centrifugal mirrors use supersonic rotation to provide axial confinement and enhanced stability. Usually the rotation is produced using electrodes, but these electrodes have limited the rotation to the Alfven critical ionization velocity, which is too slow to be useful for fusion. Instead, the rotation could be produced using radio frequency waves. A fixed azimuthal ripple is a simple and efficient wave that could produce rotation by harnessing alpha particle energy. This is an extension of the alpha channeling effect. The alpha particle power and efficiency in a simulated devices is sufficient to produce rotation without external energy input. By eliminating the need for electrodes, this opens new opportunities for centrifugal traps.

  13. Portable water filtration system for oil well fractionation

    SciTech Connect

    Seibert, D. L.

    1985-08-13

    The invention comprises a portable, multi-stage filtration system utilized in filtering water for an oil and gas stimulation process commonly known as fracking. Three stages are used, the first being a straining operation reducing the size of particulate matter in the water to about three-eighths of an inch. The second stage is a centrifugal separator, reducing the particle size to about 50 microns. The final stage utilizes a cartridge-type filter giving a final particle size in the water of about 5 microns. In this manner, water which is injected into the well head during the fracking process and which is obtained from readily available sources such as ponds, streams and the like is relatively free of particulate matter which can foul the fracking process. The invention, by virtue of being mounted on a trailer, is portable and thus can be easily moved from site to site. Water flow rates obtained using the invention are between 250 and 300 gallons per minute, sufficient for processing a small to medium sized well.

  14. Establishment and application of milk fingerprint by gel filtration chromatography.

    PubMed

    Gao, P; Li, J; Li, Z; Hao, J; Zan, L

    2016-12-01

    Raw milk adulteration frequently occurs in undeveloped countries. It not only reduces the nutritional value of milk, but it is also harmful to consumers. In this paper, we focused on investigating an efficient method for the quality control of raw milk protein. A gel filtration chromatography (GFC) fingerprint method combined with chemometrics was developed for fingerprint analysis of raw milk. To optimize the GFC conditions, milk fat was removed by centrifugation, and GFC analysis was performed on a Superdex 75 10/300GL column (Just Scientific, Shanghai, China) with 0.2 M NaH2PO4-Na2HPO4 buffer (pH 7.0) as the mobile phase. The flow rate was 0.5mL/min, and the detection wavelength was set at 280 nm. Ten batches of 120 raw milk samples were analyzed to establish the GFC fingerprint under optimal conditions. Six major peaks common to the chromatogram of each raw milk sample were selected for fingerprint analysis, and the characteristic peaks were used to establish a standard chromatographic fingerprint. Principal component analysis was then applied to classify GFC information of adulterated milk and raw milk, allowing adulterated samples to be effectively screened out from the raw milk in principal component analysis scores plot. The fingerprint method demonstrates promising features in detecting milk protein adulteration.

  15. Residual urinary extracellular vesicles in ultracentrifugation supernatants after hydrostatic filtration dialysis enrichment

    PubMed Central

    Musante, Luca; Tataruch-Weinert, Dorota; Kerjaschki, Dontscho; Henry, Michael; Meleady, Paula; Holthofer, Harry

    2017-01-01

    ABSTRACT Urinary extracellular vesicles (UEVs) appear an ideal source of biomarkers for kidney and urogenital diseases. The majority of protocols designed for their isolation are based on differential centrifugation steps. However, little is still known of the type and amount of vesicles left in the supernatant. Here we used an isolation protocol for UEVs which uses hydrostatic filtration dialysis as first pre-enrichment step, followed by differential centrifugation. Transmission electron microscopy (TEM), mass spectrometry (MS), western blot, ELISA assays and tuneable resistive pulse sensing (TRPS) were used to characterise and quantify UEVs in the ultracentrifugation supernatant. TEM showed the presence of a variety of small size vesicles in the supernatant while protein identification by MS matched accurately with the protein list available in Vesiclepedia. Screening and relative quantification for specific vesicle markers showed that the supernatant was preferentially positive for CD9 and TSG101. ELISA tests for quantification of exosome revealed that 14%, was left in the supernatant with a particle diameter of 110 nm and concentration of 1.54 × 1010/ml. Here we show a comprehensive characterisation of exosomes and other small size urinary vesicles which the conventional differential centrifugation protocol may lose. PMID:28326167

  16. Coagulation-membrane filtration of Chlorella vulgaris.

    PubMed

    Lee, Duu-Jong; Liao, Guan-Yu; Chang, Yin-Ru; Chang, Jo-Shu

    2012-03-01

    Filtration-based separation of Chlorella vulgaris, a species with excellent potential for CO(2) capture and lipid production, was investigated using a surface-modified hydrophilic polytetrafluoroethylene (PTFE) membrane. Coagulation using polyaluminum chloride (PACl) attained maximum turbidity removal at 200 mg L(-1) as Al(2)O(3). The membrane filtration flux at 1 bar increased as the PACl dose increased, regardless of overdosing in the coagulation stage. The filtered cake at the end of filtration tests peaked in solid content at 10 mg L(-1) as Al(2)O(3), reaching 34% w/w, roughly two times that of the original suspension. Differential scanning calorimetry (DSC) tests demonstrate that the cake with minimum water-solid binding strength produced the driest filter cake. Coagulation using 10 mg L(-1) PACl as Al(2)O(3), followed by PTFE membrane filtration at 1 bar, is an effective process for harvesting C. vulgaris from algal froth.

  17. Filtration in coal liquefaction - Influence of filtration conditions in non-hydrogenated systems

    NASA Astrophysics Data System (ADS)

    Clarke, J. W.; Rantell, T. D.

    1980-01-01

    A series of experiments has been carried out to study the effects of filtration conditions upon the rate of filtration of non-hydrogenated coal digests. The results show the dependence of cake resistivity on both the filtration temperature and pressure. Filter cakes were found to be compressible, resulting in smaller increases in rate with increasing pressure than with incompressible cakes. The filtration temperature determines the packing of residual solids in the cake which in turn affects the cake resistivity. An empirical relation has been derived between filtration temperature and resistivity. With increasing temperature there is an increase in filtration rate due to the reduced viscosity, but a reduction owing to a higher packing density of solids in the filter cake.

  18. Filtration treatment of dairy processing wastewater.

    PubMed

    Samkutty, Pushpa J; Gough, Ronald H

    2002-01-01

    The effectiveness of various filtration agents in the primary treatment of dairy processing wastewater was investigated in laboratory-scale studies. The filtration agents used were: zeolite, crushed coral, charcoal, sand and crushed coral and sand and glass beads. The effectiveness of the filtration media was determined by testing parameters such as chemical oxygen demand (COD), total solids (TS) and total suspended solids (TSS) before and after filtration of wastewater. Percent reduction of the different parameters as a result of filtration was calculated. Sand combined with crushed coral or glass beads was found to be the most effective filtering medium with an average reduction of 99% in TSS, 93% in COD and 51% in TS. Charcoal filtration resulted in an average 85% reduction in TSS, 83% reduction in COD and 46% reduction in TS. Filtration using crushed coral resulted in an average 83% reduction in TSS, 78% reduction in COD and 39% reduction in TS. Zeolite was the least effective of the four media; it resulted in an average reduction of 78% in TSS, 76% in COD and 30% in TS. The differences among mean values of COD, TSS and TS after the different treatments were analyzed statistically using analysis of variance (ANOVA). When differences among means were found to be statistically significant (p < 0.0001), each mean value was compared with every other mean value using Duncan's multiple range test and least significant difference (LSD) test. Comparison of the mean values indicated the following: No significant difference between means of zeolite and crushed coral treatment. Mean values of COD, TSS, and TS of charcoal treatment were significantly different from the other treatments. Sand combined with crushed coral or glass beads was the most effective filtration agent and the means were significantly different from the means of the other treatments.

  19. Vacuum chamber-free centrifuge with magnetic bearings.

    PubMed

    Park, Cheol Hoon; Kim, Soohyun; Kim, Kyung-Soo

    2013-09-01

    Centrifuges are devices that separate particles of different densities and sizes through the application of a centrifugal force. If a centrifuge could be operated under atmospheric conditions, all vacuum-related components such as the vacuum chamber, vacuum pump, diffusion pump, and sealing could be removed from a conventional centrifuge system. The design and manufacturing procedure for centrifuges could then be greatly simplified to facilitate the production of lightweight centrifuge systems of smaller volume. Furthermore, the maintenance costs incurred owing to wear and tear due to conventional ball bearings would be eliminated. In this study, we describe a novel vacuum chamber-free centrifuge supported by magnetic bearings. We demonstrate the feasibility of the vacuum chamber-free centrifuge by presenting experimental results that verify its high-speed support capability and motoring power capacity.

  20. Clean-in-Place and Reliability Testing of a Commercial 12.5 cm Annular Centrifugal Contactor at the INL

    SciTech Connect

    N. R. Mann; T. G. Garn; D. H. Meikrantz; J. D. Law; T. A. Todd

    2007-09-01

    The renewed interest in advancing nuclear energy has spawned the research of advanced technologies for recycling nuclear fuel. A significant portion of the advanced fuel cycle includes the recovery of selected actinides by solvent extraction methods utilizing centrifugal contactors. Although the use of centrifugal contactors for solvent extraction is widely known, their operation is not without challenges. Solutions generated from spent fuel dissolution contain unknown quantities of undissolved solids. A majority of these solids will be removed via various methods of filtration. However, smaller particles are expected to carry through to downstream solvent extraction processes and equipment. In addition, solids/precipitates brought about by mechanical or chemical upsets are another potential area of concern. During processing, particulate captured in the rotor assembly by high centrifugal forces eventually forms a cake-like structure on the inner wall introducing balance problems and negatively affecting phase separations. One of the features recently developed for larger engineering scale Annular Centrifugal Contactors (ACCs) is the Clean-In-Place (CIP) capability. Engineered spray nozzles were installed into the hollow central rotor shaft in all four quadrants of the rotor assembly. This arrangement allows for a very convenient and effective method of solids removal from within the rotor assembly.

  1. Clean-in-Place and Reliability Testing of a Commercial 12.5-cm Annular Centrifugal Contactor at the INL

    SciTech Connect

    N. R. Mann; T. G. Garn; D. H. Meikrantz; J. D. Law; T. A. Todd

    2007-09-01

    The renewed interest in advancing nuclear energy has spawned the research of advanced technologies for recycling nuclear fuel. A significant portion of the advanced fuel cycle includes the recovery of selected actinides by solvent extraction methods utilizing centrifugal contactors. Although the use of centrifugal contactors for solvent extraction is widely known, their operation is not without challenges. Solutions generated from spent fuel dissolution contain unknown quantities of undissolved solids. A majority of these solids will be removed via various methods of filtration. However, smaller particles are expected to carry through to downstream solvent extraction processes and equipment. In addition, solids/precipitates brought about by mechanical or chemical upsets are another potential area of concern. During processing, particulate captured in the rotor assembly by high centrifugal forces eventually forms a cake-like structure on the inner wall introducing balance problems and negatively affecting phase separations. One of the features recently developed for larger engineering scale Annular Centrifugal Contactors (ACCs) is the Clean-In-Place (CIP) capability. Engineered spray nozzles were installed into the hollow central rotor shaft in all four quadrants of the rotor assembly. This arrangement allows for a very convenient and effective method of solids removal from within the rotor assembly.

  2. 21 CFR 864.5350 - Microsedimentation centrifuge.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Microsedimentation centrifuge. 864.5350 Section 864.5350 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES HEMATOLOGY AND PATHOLOGY DEVICES Automated and Semi-Automated Hematology...

  3. 21 CFR 864.5350 - Microsedimentation centrifuge.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Microsedimentation centrifuge. 864.5350 Section 864.5350 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES HEMATOLOGY AND PATHOLOGY DEVICES Automated and Semi-Automated Hematology...

  4. Research centrifuge accommodations on Space Station Freedom

    NASA Technical Reports Server (NTRS)

    Arno, Roger D.; Horkachuk, Michael J.

    1990-01-01

    Life sciences research using plants and animals on the Space Station Freedom requires the ability to maintain live subjects in a safe and low stress environment for long durations at microgravity and at one g. The need for a centrifuge to achieve these accelerations is evident. Programmatic, technical, and cost considerations currently favor a 2.5 meter diameter centrifuge located either in the end cone of a Space Station Freedom node or in a separate module. A centrifuge facility could support a mix of rodent, plant, and small primate habitats. An automated cage extractor could be used to remove modular habitats in pairs without stopping the main rotor, minimizing the disruption to experiment protocols. The accommodation of such a centrifuge facility on the Space Station represents a significant demand on the crew time, power, data, volume, and logistics capability. It will contribute to a better understanding of the effects of space flight on humans, an understanding of plant growth in space for the eventual production of food, and an understanding of the role of gravity in biological processes.

  5. Predicting Droplet Formation on Centrifugal Microfluidic Platforms

    NASA Astrophysics Data System (ADS)

    Moebius, Jacob Alfred

    Centrifugal microfluidics is a widely known research tool for biological sample and water quality analysis. Currently, the standard equipment used for such diagnostic applications include slow, bulky machines controlled by multiple operators. These machines can be condensed into a smaller, faster benchtop sample-to-answer system. Sample processing is an important step taken to extract, isolate, and convert biological factors, such as nucleic acids or proteins, from a raw sample to an analyzable solution. Volume definition is one such step. The focus of this thesis is the development of a model predicting monodispersed droplet formation and the application of droplets as a technique for volume definition. First, a background of droplet microfluidic platforms is presented, along with current biological analysis technologies and the advantages of integrating such technologies onto microfluidic platforms. Second, background and theories of centrifugal microfluidics is given, followed by theories relevant to droplet emulsions. Third, fabrication techniques for centrifugal microfluidic designs are discussed. Finally, the development of a model for predicting droplet formation on the centrifugal microfluidic platform are presented for the rest of the thesis. Predicting droplet formation analytically based on the volumetric flow rates of the continuous and dispersed phases, the ratios of these two flow rates, and the interfacial tension between the continuous and dispersed phases presented many challenges, which will be discussed in this work. Experimental validation was completed using continuous phase solutions of different interfacial tensions. To conclude, prospective applications are discussed with expected challenges.

  6. Centrifugal Pump Experiment for Chemical Engineering Undergraduates

    ERIC Educational Resources Information Center

    Vanderslice, Nicholas; Oberto, Richard; Marrero, Thomas R.

    2012-01-01

    The purpose of this paper is to describe a Centrifugal Pump Experiment that provided an experiential learning experience to chemical engineering undergraduates at the University of Missouri in the spring of 2010 in the Unit Operations Laboratory course. Lab equipment was used by senior students with computer-based data and control technology. In…

  7. Extracting hydrocarbons from water using a centrifuge

    NASA Astrophysics Data System (ADS)

    Ryabov, A. Yu.; Ilyina, A. A.; Chuikin, A. V.; Velikov, A. A.

    2014-09-01

    An original method for the solid-phase microextraction of hydrocarbons from water using a centrifuge is proposed. Comparative results from the chromatographic elution of substances after liquid-phase and solid-phase microextraction are presented. The percentage of the extraction of substances from aqueous solutions and the minimum detection limit for aromatic and aliphatic compounds are calculated.

  8. Differential white cell count by centrifugal microfluidics.

    SciTech Connect

    Sommer, Gregory Jon; Tentori, Augusto M.; Schaff, Ulrich Y.

    2010-07-01

    We present a method for counting white blood cells that is uniquely compatible with centrifugation based microfluidics. Blood is deposited on top of one or more layers of density media within a microfluidic disk. Spinning the disk causes the cell populations within whole blood to settle through the media, reaching an equilibrium based on the density of each cell type. Separation and fluorescence measurement of cell types stained with a DNA dye is demonstrated using this technique. The integrated signal from bands of fluorescent microspheres is shown to be proportional to their initial concentration in suspension. Among the current generation of medical diagnostics are devices based on the principle of centrifuging a CD sized disk functionalized with microfluidics. These portable 'lab on a disk' devices are capable of conducting multiple assays directly from a blood sample, embodied by platforms developed by Gyros, Samsung, and Abaxis. [1,2] However, no centrifugal platform to date includes a differential white blood cell count, which is an important metric complimentary to diagnostic assays. Measuring the differential white blood cell count (the relative fraction of granulocytes, lymphocytes, and monocytes) is a standard medical diagnostic technique useful for identifying sepsis, leukemia, AIDS, radiation exposure, and a host of other conditions that affect the immune system. Several methods exist for measuring the relative white blood cell count including flow cytometry, electrical impedance, and visual identification from a stained drop of blood under a microscope. However, none of these methods is easily incorporated into a centrifugal microfluidic diagnostic platform.

  9. Centrifugal blood pumps for various clinical needs.

    PubMed

    Ichikawa, Seiji; Nosé, Yukihiko

    2002-11-01

    During the past 10 years, different types of blood pumps were developed to address various clinical needs. The Nikkiso centrifugal blood pump was developed for cardiopulmonary bypass application. This blood pump has been widely used in Japan in more than 20% of the cardiopulmonary bypass procedures. The Kyocera C1E3 Gryo pump was developed for short-term circulatory assistance and extracorporeal membrane oxygenation application for up to 2 weeks. This blood pump has been clinically used for up to 28 days without any blood clot formation. Through Phase I of the Japanese government New Energy and Industrial Technology Development Organization (NEDO) program, a chronically implanted centrifugal pump for left ventricular assistance was developed. This pump has already demonstrated its effectiveness, safety, and durability as a 2 year blood pump through in vitro and in vivo experiments. Currently, it is in the process of being converted from an experimental to a clinical device. Through Phase II of the NEDO program, a permanently implantable biventricular assist centrifugal blood pump system is under development. It has demonstrated that the previously mentioned left ventricular assist device blood pump is easily converted into a right ventricular assist pump by simply adding a spacer between the pump and the actuator. This communication discusses the historical development strategies for centrifugal blood pumps and their current status for different clinical needs.

  10. 21 CFR 864.5350 - Microsedimentation centrifuge.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Microsedimentation centrifuge. 864.5350 Section 864.5350 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES HEMATOLOGY AND PATHOLOGY DEVICES Automated and Semi-Automated Hematology...

  11. 21 CFR 864.5350 - Microsedimentation centrifuge.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Microsedimentation centrifuge. 864.5350 Section 864.5350 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES HEMATOLOGY AND PATHOLOGY DEVICES Automated and Semi-Automated Hematology...

  12. 21 CFR 864.5350 - Microsedimentation centrifuge.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Microsedimentation centrifuge. 864.5350 Section 864.5350 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES HEMATOLOGY AND PATHOLOGY DEVICES Automated and Semi-Automated Hematology...

  13. Evaluation of an improved centrifugal casting machine.

    PubMed

    Donovan, T E; White, L E

    1985-05-01

    A Type III gold alloy, a silver-palladium alloy, and a base metal alloy were cast in two different centrifugal casting machines. With the number of complete cast mesh squares as an indicator of castability, the Airspin casting machine produced superior castings with all three alloys. The base metal alloy produced the greatest number of complete squares with both casting machines.

  14. Pressure distribution in centrifugal dental casting.

    PubMed

    Nielsen, J P

    1978-02-01

    Equations are developed for liquid metal pressure in centrifugal dental casting, given the instantaneous rotational velocity, density, and certain dimensions of the casting machine and casting pattern. A "reference parabola" is introduced making the fluid pressure concept more understandable. A specially designed specimen demonstrates experimentally the reference parabola at freezing.

  15. Flow Pattern Characterization for a Centrifugal Impeller

    NASA Astrophysics Data System (ADS)

    Benavides, Efrén M.

    2014-08-01

    This paper proposes a model for characterizing the flow pattern of a centrifugal impeller attending to the severity of the reverse flow. The model assumes 1) a definition of an escaping particle as the one that flows in every operational point from the trailing edge towards the leading edge of the impeller blades, and 2) a characterization of flow where an operational point is said to have a theoretical flow pattern if it is not possible to establish a fully-reversed escaping particle on it. Therefore, the first part of the article is focused on defining an escaping particle for a centrifugal compressor. The model locates over the map of a centrifugal impeller the line that splits the map in two regions: the region on the right hand side, where a theoretical flow pattern can exist, and the region on the left, where a theoretical flow pattern cannot exist. Therefore, the locus of this line marks a frontier where the expected performance of the impeller cannot be sustained as high as expected. The second part of the article uses a high-performance commercial centrifugal impeller wheel for contrasting the model. A qualitative characterization of the surge line, conclusions and discussions are presented.

  16. APPLICATION ANALYSIS REPORT: RETECH PLASMA CENTRIFUGAL FURNACE

    EPA Science Inventory

    This document is an evaluation of the performance of the Retech, Inc. Plasma Centrifugal Furnace (PCF) and its applicability as a treatment for soils contaminated with organic and/or inorganic compounds. Both the technical and economic aspectsof the technology were examined. A...

  17. Mass Transfer in 12-CM Centrifugal Contactors

    SciTech Connect

    Chesna, J.C.

    2001-06-26

    One eight-stage unit (8-pack) of centrifugal contactors was tested in both extraction and stripping modes. Efficiencies approaching 100 percent were obtained in both modes. The contactors were operated successfully at a wide range of combined flow rates, including the HEF conditions. This report discusses the results of that test.

  18. 76 FR 9613 - USEC Inc. (American Centrifuge Lead Cascade Facility and American Centrifuge Plant); Order...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-02-18

    ... use source and special nuclear material at the Lead Cascade at the Portsmouth Gaseous Diffusion Plant... operate a gas centrifuge uranium enrichment facility (the ACP) at the Portsmouth Gaseous Diffusion...

  19. Mechanisms of Sensorimotor Adaptation to Centrifugation

    NASA Technical Reports Server (NTRS)

    Paloski, W. H.; Wood, S. J.; Kaufman, G. D.

    1999-01-01

    We postulate that centripetal acceleration induced by centrifugation can be used as an inflight sensorimotor countermeasure to retain and/or promote appropriate crewmember responses to sustained changes in gravito-inertial force conditions. Active voluntary motion is required to promote vestibular system conditioning, and both visual and graviceptor sensory feedback are critical for evaluating internal representations of spatial orientation. The goal of our investigation is to use centrifugation to develop an analog to the conflicting visual/gravito-inertial force environment experienced during space flight, and to use voluntary head movements during centrifugation to study mechanisms of adaptation to altered gravity environments. We address the following two hypotheses: (1) Discordant canal-otolith feedback during head movements in a hypergravity tilted environment will cause a reorganization of the spatial processing required for multisensory integration and motor control, resulting in decreased postural stability upon return to normal gravity environment. (2) Adaptation to this "gravito-inertial tilt distortion" will result in a negative after-effect, and readaptation will be expressed by return of postural stability to baseline conditions. During the third year of our grant we concentrated on examining changes in balance control following 90-180 min of centrifugation at 1.4 9. We also began a control study in which we exposed subjects to 90 min of sustained roll tilt in a static (non-rotating) chair. This allowed us to examine adaptation to roll tilt without the hypergravity induced by centrifugation. To these ends, we addressed the question: Is gravity an internal calibration reference for postural control? The remainder of this report is limited to presenting preliminary findings from this study.

  20. Centrifugal Modelling of Soil Structures. Part I. Centrifugal Modelling of Slope Failures.

    DTIC Science & Technology

    1979-03-01

    centrifugal loading in multiples of earth’s gravitational acceleration Nd number of equipotential drops in a flow net Nf number of flow channels in a... straight line from point A to point B. It is valid for laminar flow , where v - discharge velocity, k - coefficient of permeability, i - hydraulic gradient...number) Soil mechanics, embankmen’: stability, sloPe Stability, centrifuge modelling, clay slopes, mine waste slltpes, sea clay, landslides, flow slides

  1. A new method for yeast recovery in batch ethanol fermentations: filter aid filtration followed by separation of yeast from filter aid using hydrocyclones.

    PubMed

    da Matta, V M; Medronho, R de A

    2000-01-01

    In the Melle-Boinot process for alcohol production, centrifuges are normally used for yeast recovery at the end of a batch fermentation. Centrifuges are expensive equipment and represent an impressive part of the equipment costs in alcohol industries. In the present work, an alternative method for yeast recovery using less expensive equipment was studied. Instead of using centrifuges, yeast was separated from the fermented broth by filter aid filtration, followed by separation of yeast from the filter aid using hydrocyclones. A stainless steel plate-and-frame filter of filtration area 1.14 m2 and two 30 mm hydrocyclones, which followed the Bradley and Rietema recommended proportions, were used in this work. The filter aid was perlite. Tests of direct separation of yeast from the fermented broth using the Bradley hydrocyclone proved to be completely unfeasible, since the maximal reduced total efficiency obtained was only 1%. When the hydrocyclones were used to separate perlite from the resuspended filtration cake, the perlite total separation efficiency obtained in the underflow was as high as 95% when using the Bradley hydrocyclone with an underflow diameter of 3 mm. To show the feasibility of the proposed new method of yeast recovery, a complete cycle of experiments, which included fermentation, yeast separation, and new fermentation using the recycled cells, was performed with good results.

  2. 5. View northeast of rear of filtration bed building. Note ...

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

    5. View northeast of rear of filtration bed building. Note monitor roof with clerestory windows over central corridor between filtration beds at center right of photograph. Laboratory building is at extreme center right of photograph. - Lake Whitney Water Filtration Plant, Filtration Plant, South side of Armory Street between Edgehill Road & Whitney Avenue, Hamden, New Haven County, CT

  3. 10. View west of east entry to filtration beds. Note ...

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

    10. View west of east entry to filtration beds. Note monitor roof and clerestory windows over central corridor. Laboratory building is sited over the center of the filtration bed building at extreme left center of photograph. - Lake Whitney Water Filtration Plant, Filtration Plant, South side of Armory Street between Edgehill Road & Whitney Avenue, Hamden, New Haven County, CT

  4. 6. Detail view northeast of rear of filtration bed building. ...

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

    6. Detail view northeast of rear of filtration bed building. Note monitor roof with clerestory windows over central corridor between filtration beds at center right of photograph. Laboratory building is at center right of photograph. - Lake Whitney Water Filtration Plant, Filtration Plant, South side of Armory Street between Edgehill Road & Whitney Avenue, Hamden, New Haven County, CT

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

    EPA Science Inventory

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

  6. 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...

  7. Dynamic filtration of invert-emulsion muds

    SciTech Connect

    Jiao, D.; Sharma, M.M. )

    1993-09-01

    Dynamic-filtration experiments conducted on oil-based muds show that the dynamic-filtration rate is much higher than API filtration rates. The use of water-wet solids results in very poor-quality external mudcakes and high fluid-loss rates. Better external mudcakes are formed by mixing equal parts organophilic clay and mud. Filtration-loss-control additives (asphalt mineral pitches) do not reduce the equilibrium filtration rate, but do reduce spurt loss and limit solids invasion. In brine-saturated rocks, the invasion rate for oil-based muds is significantly smaller than for water-based muds because capillary pressure prevents the oil phase from entering the core in oil-based muds. Oil-based mudcakes are softer and more shear-sensitive than water-based mudcakes. Scanning electron microscope (SEM) photomicrographs indicate that oil-based mudcakes consist of individual water droplets coated with clay particles. This cake structure gives rise to the low permeability and shear sensitivity of oil-based muds.

  8. High stability design for new centrifugal compressor

    NASA Technical Reports Server (NTRS)

    Kanki, H.; Katayama, K.; Morii, S.; Mouri, Y.; Umemura, S.; Ozawa, U.; Oda, T.

    1989-01-01

    It is essential that high-performance centrifugal compressors be free of subsynchronous vibrations. A new high-performance centrifugal compressor has been developed by applying the latest rotordynamics knowledge and design techniques: (1) To improve the system damping, a specially designed oil film seal was developed. This seal attained a damping ratio three times that of the conventional design. The oil film seal contains a special damper ring in the seal cartridge. (2) To reduce the destabilizing effect of the labyrinth seal, a special swirl canceler (anti-swirl nozzle) was applied to the balance piston seal. (3) To confirm the system damping margin, the dynamic simulation rotor model test and the full load test applied the vibration exciting test in actual load conditions.

  9. A centrifugal pump used as a turbine

    SciTech Connect

    Yap, F.U.; Lasnier, F. )

    1990-06-01

    Due to the high cost of putting up conventional turbines for micro-hydropower installations, Inversin (1986) mentioned the use of pumps being run in reverse to function as turbines. Typical performance characteristics of a centrifugal pump running as a turbine are shown in a figure. Pump/turbine maximum efficiencies tend to occur over a wide range of capacity. This study is concerned with the use of non-conventional hydro equipment, locally and readily available for small rural electricity applications. Here, the operation of a small centrifugal pump, used as a turbine and coupled with a conventional car alternator, was investigated. The article reveals a method for evaluating not only this but other small generating systems for appropriateness to the conditions of the site.

  10. Spaceborne centrifugal relays for spacecraft propulsion

    NASA Technical Reports Server (NTRS)

    Ouzidane, Malika

    1991-01-01

    Acceleration using centrifugal relays is a recently discovered method for the acceleration of spaceborne payloads to high velocity at high thrust. Centrifugal relays are moving rotors which progressively accelerate reaction mass to higher velocities. One important engineering problem consists of accurately tracking the position of the projectiles and rotors and guiding each projectile exactly onto the appropriate guide tracks on each rotor. The topics of this research are the system kinematics and dynamics and the computerized guidance system which will allow the projectile to approach each rotor with exact timing with respect to the rotor rotation period and with very small errors in lateral positions. Kinematics studies include analysis of rotor and projectile positions versus time and projectile/rotor interactions. Guidance studies include a detailed description of the tracking mechanism (interrupt of optical beams) and the aiming mechanism (electromagnetic focusing) including the design of electromagnetic deflection coils and the switching circuitry.

  11. Optimum design for LRE centrifugal pumps

    NASA Astrophysics Data System (ADS)

    Zhu, Zuchao; Zhang, Guoqian; Sun, Jiren

    1995-05-01

    We set up a mathematical model to predict low specific speed liquid rocket engine (LRE) centrifugal pump unit performance. Using the model in question, performance predictions were carried out for 10 types of LRE centrifugal pumps. Relative errors between experimental values and predicted values associated with efficiency and lift were all within 4%. Using the model in question, design optimization with efficiency as the target function was carried out on AM-7H and O pumps as well as AM-1R pumps and AM-50 pumps. Results clearly show that, with a presupposition of surety systems possessing high vapor corrosion characteristics, the efficiencies of these four types of pumps can be respectively raised 6.5%, 5.22%, 5.2%, and 4.41%.

  12. Mathematical simulation of centrifugal casting of pipes

    SciTech Connect

    Minosyan, Ya.P.; Gerasimov, V.G.; Ryadno, A.A.; Solov'yev, Yu.G.

    1983-01-01

    A mathematical description of centrifugal casting of long pipes in rapidly-rotating ingot molds is given. The effect of gravity force is neglected. A numerical solution is obtained for the solidification of a steel casting in a thermally insulated mold. The effect of the rate of metal pouring on the motion of the solidification interface is investigated. The disagreement with experimental data is less then 7 percent.

  13. Centrifugal shot blasting. Innovative technology summary report

    SciTech Connect

    Not Available

    1999-07-01

    At the US Department of Energy (DOE) Fernald Environmental Management Project (FEMP), the Facilities Closure and Demolition Projects Integrated Remedial Design/Remedial Action (RD/RA) work plan calls for the removal of one inch (1 in) depth of concrete surface in areas where contamination with technetium-99 has been identified. This report describes a comparative demonstration between two concrete removal technologies: an innovative system using Centrifugal Shot Blasting (CSB) and a modified baseline technology called a rotary drum planer.

  14. Operating and maintenance guidelines for screenbowl centrifuges

    SciTech Connect

    Jahnig, W.S.R.; Bratton, R.; Luttrell, G.

    2009-01-15

    Plant dewatering circuits equipped with screenbowl centrifuges need to be well designed, properly operated, and adequately maintained to maximize the dewatering performance. The most important 'feed variables' are particle size, dry solids feed rate and slurry flow rate. The most important 'machine variables' include pool depth, rotational speed and gearbox ratio. The article discusses the effect of these parameters and offers some maintenance guidelines. The article was adapted from a paper presented at CoalPrep 2008. 6 refs., 2 figs., 2 tabs.

  15. Potential flow through centrifugal pumps and turbines

    NASA Technical Reports Server (NTRS)

    Sorensen, E

    1941-01-01

    The methods of conformal transformation up to the present have been applied to the potential flows in the rotation of solid bodies only to a limited extent. This report deals with aspects of centrifugal pumps and turbines such as: the complex potential for rotation, potential for the flow due to the blade rotation, velocities at the blade tip, comparison with "infinite number of blades," and a variable number of blades.

  16. Wave-driven Countercurrent Plasma Centrifuge

    SciTech Connect

    A.J. Fetterman and N.J. Fisch

    2009-03-20

    A method for driving rotation and a countercurrent flow in a fully ionized plasma centrifuge is described. The rotation is produced by radiofrequency waves near the cyclotron resonance. The wave energy is transferred into potential energy in a manner similar to the α channeling effect. The countercurrent flow may also be driven by radiofrequency waves. By driving both the rotation and the flow pattern using waves instead of electrodes, physical and engineering issues may be avoided.

  17. Femoral development in chronically centrifuged rats

    NASA Technical Reports Server (NTRS)

    Smith, S. D.

    1977-01-01

    Groups of 30-d-old male and female rats were centrifuged at 2.00 G (RE, Rotation Experimental), 1.05 G (RC, Rotation Control) or exposed to the noise and wind of the centrifuge at 1.00 G (EC, Earth Control) for periods of 1, 2, 4, 8, and 16 weeks. Measurements of their femurs indicated that exposure to centrifugation a) decreased femoral length in RE animals, b) increased femoral length in RC animals, c) reduced femoral diameter in RE and RC animals, d) increased L/D ratios in RC animals, e) decreased L/D ratios in RE animals, f) increased femur length/body weight in RE animals, g) decreased cortical thickness (CT) in RE animals, h) increased relative CT in RE animals, and decreased it in RC animals, i) accelerated ossification in RC femoral heads, j) thinned and distorted RE epiphyseal plates, and k) thickened condylar cartilage in RE females. The effects tended to be strongly sexually dimorphic, with females more severely affected by the stress than males.

  18. Avoid self-priming centrifugal pump

    SciTech Connect

    Reeves, G.G.

    1987-01-01

    The self-priming horizontal centrifugal pump becomes known to its operator either as a good pump or a bad pump. The latter is usually replaced by another type of pump, even though a properly specified self-priming centrifugal pump might have been a good choice. Use of the guidelines described in this article are intended to help in the purchase and installation of a good pump. Self-priming centrifugal pumps are used for removing liquids from below grade sumps or pits that may also contain solids, fibers and/or muck. Alternate pumps for this service include submersible pumps, vertical turbine pumps and positive displacement pumps. These alternate pumps do not pass solid particles as large as self-priming pumps do without damage. Positive displacement pumps are not normally cost-effective when pumping liquid at rates in excess of 500 gallons per minute in low-head applications. Vertical and submersible pumps must be removed when cleaning of the pump is required. Self-priming pumps are easily cleaned by opening the access plates without moving the pump; and they cost less than the other types.

  19. Effects of scaling on centrifugal blood pumps.

    PubMed

    Wong, Yew Wah; Chan, Weng Kong; Yu, S C M; Chua, Leok Poh

    2002-11-01

    Experimental studies on the effects of scaling on the performance of centrifugal blood pumps were conducted in a closed-loop test rig. For the prototype, eight different impellers of the same outer diameter of 25 mm were tested at 1,500, 2,000, and 2,500 revolutions per minute (rpm) using blood analog as fluid medium. This corresponds to Reynolds numbers (Re) of 25,900, 34,500, and 43,200, respectively. The results indicated that the nondimensional pump characteristic is a function of Re. This is understandable since the typical operating Re for centrifugal blood pumps is less than 100,000. Thus, the effects of scaling cannot be ignored for centrifugal blood pumps. Experiments on a 5x scaled-up model have also indicated that the scaled-up model is more efficient than the prototype model. Our results showed that in the range of Re tested, the nondimensional head versus flow curve is a function of Re to the power of approximately 0.25. It is observed that the nondimensional head versus flow is a function of diameter ratio to the power of 0.2.

  20. Research opportunities with the Centrifuge Facility

    NASA Astrophysics Data System (ADS)

    Funk, Glenn A.

    The Centrifuge Facility on Space Station Freedom will consist of a 2.5-meter diameter Centrifuge accommodating two concentric rings of habitats and providing variable g-forces between 0.01 g and 2.0 g; modular habitats providing housing and lifesupport for rats, mice, and plants; a habitat holding system providing power, water, airflow and other utilities to several modular habitats; and a life sciences glovebox, an isolated work volume accommodating simultaneous operations by at least two scientists and providing lighting, airflow, video and data access, and other experiment support functions. The centrifuge facility will enable long-duration animal and plant microgravity research not previously possible in the NASA flight research program. It will offer unprecedented opportunities for use of on-board 1-g control populations and statistically significant numbers of specimens. On orbit 1-g controls will allow separation of the effects of microgravity from other environmental factors. Its selectable-g and simultaneous multiple-g capabilities will enable studies of gravitational thresholds, the use of artificial gravity as a countermeasure to the effects of microgravity, and ready simulation of Lunar and Martian gravities.

  1. Research opportunities with the Centrifuge Facility

    NASA Technical Reports Server (NTRS)

    Funk, Glenn A.

    1992-01-01

    The Centrifuge Facility on Space Station Freedom will consist of a 2.5-meter diameter Centrifuge accommodating two concentric rings of habitats and providing variable g-forces between 0.01 g and 2.0 g; modular habitats providing housing and lifesupport for rats, mice, and plants; a habitat holding system providing power, water, airflow and other utilities to several modular habitats; and a life sciences glovebox, an isolated work volume accommodating simultaneous operations by at least two scientists and providing lighting, airflow, video and data access, and other experiment support functions. The centrifuge facility will enable long-duration animal and plant microgravity research not previously possible in the NASA flight research program. It will offer unprecedented opportunities for use of on-board 1-g control populations and statistically significant numbers of specimens. On orbit 1-g controls will allow separation of the effects of microgravity from other environmental factors. Its selectable-g and simultaneous multiple-g capabilities will enable studies of gravitational thresholds, the use of artificial gravity as a countermeasure to the effects of microgravity, and ready simulation of Lunar and Martian gravities.

  2. Shallow water model for horizontal centrifugal casting

    NASA Astrophysics Data System (ADS)

    Boháček, J.; Kharicha, A.; Ludwig, A.; Wu, M.

    2012-07-01

    A numerical model was proposed to simulate the solidification process of an outer shell of work roll made by the horizontal centrifugal casting technique. Shallow water model was adopted to solve the 2D average flow dynamics of melt spreading and the average temperature distribution inside the centrifugal casting mould by considering the centrifugal force, Coriolis force, viscous force due to zero velocity on the mould wall, gravity, and energy transport by the flow. Additionally, a 1D sub-model was implemented to consider the heat transfer in the radial direction from the solidifying shell to the mould. The solidification front was tracked by fulfilling the Stefan condition. Radiative and convective heat losses were included from both, the free liquid surface and the outer wall of the mould. Several cases were simulated with the following assumed initial conditions: constant height of the liquid metal (10, 20, and 30 mm), uniform temperature of the free liquid surface (1755 K). The simulation results have shown that while the solidification front remained rather flat, the free surface was disturbed by waves. The amplitude of waves increased with the liquid height. Free surface waves diminished as the solidification proceeded.

  3. Compact, Automated Centrifugal Slide-Staining System

    NASA Technical Reports Server (NTRS)

    Feeback, Daniel L.; Clarke, Mark S. F.

    2004-01-01

    The Directional Acceleration Vector-Driven Displacement of Fluids (DAVD-DOF) system, under development at the time of reporting the information for this article, would be a relatively compact, automated, centrifugally actuated system for staining blood smears and other microbiological samples on glass microscope slides in either a microgravitational or a normal Earth gravitational environment. The DAVD-DOF concept is a successor to the centrifuge-operated slide stainer (COSS) concept, which was reported in Slide-Staining System for Microgravity or Gravity (MSC-22949), NASA Tech Briefs, Vol. 25, No. 1 (January, 2001), page 64. The COSS includes reservoirs and a staining chamber that contains a microscope slide to which a biological sample is affixed. The staining chamber is sequentially filled with and drained of staining and related liquids from the reservoirs by use of a weighted plunger to force liquid from one reservoir to another at a constant level of hypergravity maintained in a standard swing-bucket centrifuge. In the DAVD-DOF system, a staining chamber containing a sample would also be sequentially filled and emptied, but with important differences. Instead of a simple microscope slide, one would use a special microscope slide on which would be fabricated a network of very small reservoirs and narrow channels connected to a staining chamber (see figure). Unlike in the COSS, displacement of liquid would be effected by use of the weight of the liquid itself, rather than the weight of a plunger.

  4. Maize genome sequencing by methylation filtration.

    PubMed

    Palmer, Lance E; Rabinowicz, Pablo D; O'Shaughnessy, Andrew L; Balija, Vivekanand S; Nascimento, Lidia U; Dike, Sujit; de la Bastide, Melissa; Martienssen, Robert A; McCombie, W Richard

    2003-12-19

    Gene enrichment strategies offer an alternative to sequencing large and repetitive genomes such as that of maize. We report the generation and analysis of nearly 100,000 undermethylated (or methylation filtration) maize sequences. Comparison with the rice genome reveals that methylation filtration results in a more comprehensive representation of maize genes than those that result from expressed sequence tags or transposon insertion sites sequences. About 7% of the repetitive DNA is unmethylated and thus selected in our libraries, but potentially active transposons and unmethylated organelle genomes can be identified. Reverse transcription polymerase chain reaction can be used to finish the maize transcriptome.

  5. Quantifying oil filtration effects on bearing life

    NASA Technical Reports Server (NTRS)

    Needelman, William M.; Zaretsky, Erwin V.

    1991-01-01

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

  6. Vacuum distillation/vapor filtration water recovery

    NASA Technical Reports Server (NTRS)

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

    1974-01-01

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

  7. Filtration of A Hanford AN-104 Sample

    SciTech Connect

    Poirier, MichaelR

    2004-03-01

    The Savannah River Technology Center (SRTC) conducted ultrafiltration tests with samples from the Hanford Site's AN-104 tank. The test objectives were to measure filter flux during dewatering and the removal of soluble species during washing. The filtration tests were conducted with the Cells Unit Filter (CUF) currently installed in Cell 16 of the SRTC High Activity Caves. Following filtration, personnel performed inhibited water washing to remove soluble species. Because of the limited volume of concentrated slurry, the washing was performed with a volumetric flask rather than a crossflow filter.Following the washing, personnel chemically cleaned the filter with 1 M nitric acid and periodically measured the clean water flux.

  8. Filtration of a Hanford AN-104 Sample

    SciTech Connect

    POIRIER, MICHAEL

    2004-04-19

    The Savannah River Technology Center (SRTC) conducted ultrafiltration tests with samples from the Hanford Site's 241-AN-104 tank. The test objectives were to measure filter flux during dewatering and the removal of soluble species during washing. The filtration tests were conducted with the Cells Unit Filter (CUF) currently installed in Cell 16 of the SRTC High Activity Caves. Following filtration, personnel performed inhibited water washing to remove soluble species. Because of the limited volume of concentrated slurry, the washing was performed with a volumetric flask rather than a crossflow filter. Following the washing, personnel chemically cleaned the filter with 1 M nitric acid and periodically measured the clean water flux.

  9. 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

  10. Mechanisms of pressure filtration of liquid aluminum alloys

    NASA Astrophysics Data System (ADS)

    Cao, X.

    2006-12-01

    The Prefil Footprinter, a portable pressure filtration instrument, is usually used to detect the quality of liquid aluminum alloys. However, no investigations have ever been done to calculate the cake resistance to date. Based on the identification and classification of flow behavior using the first derivative method for filtrate mass vs filtration time curves, conventional filtration equations are successfully employed to understand the filtration behaviors. From the analyses of the variations of cake resistance with filtration time, the filtration mechanisms are discussed in detail over the different filtration stages. During the steady stage, either incompressible or compressible cake mode is the main mechanism. At the initial and terminal transient stages, however, deep-bed filtration, complete straining, and solidification clogging may appear. Solid inclusions in liquid metal have significant influence on the cake structures and properties. Some important issues related to the heterogeneity of filter media and test methodology are highlighted in this work.

  11. Effects of continuous flow centrifugation on measurements of trace elements in river water: intrinsic contamination and particle fragmentation

    NASA Astrophysics Data System (ADS)

    Rossé, Patrick; Vignati, Davide; Dominik, Janusz

    2006-08-01

    Continuous flow centrifugation (CFC) is a well-established technique used in natural surface water studies to collect large amounts of suspended solids, thus allowing a broad spectrum of measurements. However, a potential contamination or changes in the particle size distribution during the centrifugation may restrain the use of CFC effluents for element analysis in the colloidal and dissolved fractions. In this paper we evaluate the possibility of using the effluent of a Westfalia centrifuge (type KA2-06-075, 9700 rpm) for such analysis. This evaluation is based on two laboratory experiments with deionized and tap water and two field experiments in rivers. Elemental concentration changes across the CFC were assessed from the CFC influent and effluent after a filtration at 0.45 μm. Significant increases were found, mainly in the field experiments at a high suspended solids level and a slightly acid pH. A hypothesis was made on the origin of these increases as a superposition of a centrifuge intrinsic contamination and a particle fragmentation effect. A numerical model based on elemental concentration measurements (inductively coupled plasma mass spectrometry) gave a particle fragmentation level of 0.55% (mass percentage of particles broken up into smaller fragments during centrifugation). In another experiment, a direct particle counting (single particle counter) shows an excess of particles smaller than 500 nm in the CFC effluent, corresponding to a fragmentation level of 0.11%. In consequence, the use of CFC effluent for element analysis is possible in low-turbidity river or lake waters, but should be carefully considered in waters with high suspended matter contents.

  12. Harvesting of Dunaliella tertiolecta cells by magnetic filtration

    NASA Astrophysics Data System (ADS)

    Manousakis, Emmanouil; Manariotis, Ioannis D.

    2015-04-01

    The rising cost and reduced reserves of fossil fuels have enhanced the interest for finding alterative energy sources. Microalgae are considered to be the only sustainable option in biodiesel production for two key points. The energy yield from microalgae is much higher than that of oil producing crops, and the cultivation of algae it is not antagonistic with food supply chain. Because of the small size of microalgae and the dilute nature of algal cultures, the harvesting cost of microalgae is so far a limiting step for the scale up of microalgal biofuel production. It is estimated that the algal harvesting cost is at least 20-30% of the total biomass production cost. Traditional methods, which have been employed for the recovery of microalgal biomass, include centrifugation, gravity separation, filtration, flocculation, and flotation. Alternative approaches, other than conventional methods, capable of processing large cultures volume at a low cost, and reducing effluent toxicity are essential for microalgal biomass production. Magnetic separation is a promising technology and has been applied for algal removal in the mid of 1970s. The aim of this study was to investigate the harvesting of microalgae cells using magnetic microparticles (MPs). Dunaliella tertiolecta was selected as a representative for marine microalgae. The cultivation of microalgae was conducted under continuous artificial light, in 20 L flasks. Iron oxide microparticles were prepared by microwave irradiation of FeSO4 7H2O in an alkaline solution. Samples were taken at different operation intervals to conduct harvesting studies. Batch and flow-through experiments were conducted in order to investigate the effect of the magnetic material on microalgae removal. Algal removal in flow through experiments ranged from 70 to 85% depending on the initial MPs concentration even at very short hydraulic retention times (i.e. 2 min). In batch tests, algal removal was up to 97% at MPs concentration of 490 mg/L.

  13. Plasma discharge self-cleaning filtration system

    SciTech Connect

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

    2014-07-22

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

  14. Gel Filtration Chromatography: A Laboratory Experiment.

    ERIC Educational Resources Information Center

    Hurlbut, Jeffrey A.; Schonbeck, Niels D.

    1984-01-01

    Describes a rapid, visual demonstration of protein separation by gel filtration chromatography. The procedure separates two highly colored proteins of different molecular weights on a Sephadex G-75 in 45 minutes. This time includes packing the column as well. Background information, reagents needed, procedures used, and results obtained are…

  15. Solute partitioning and filtration by extracellular matrices

    PubMed Central

    Hofmann, Christina L.; Ferrell, Nicholas; Schnell, Lisa; Dubnisheva, Anna; Zydney, Andrew L.; Yurchenco, Peter D.; Roy, Shuvo

    2009-01-01

    The physiology of glomerular filtration remains mechanistically obscure despite its importance in disease. The correspondence between proteinuria and foot process effacement suggests podocytes as the locus of the filtration barrier. If so, retained macromolecules ought to accumulate at the filtration barrier, an effect called concentration polarization. Literature data indicate macromolecule concentrations decrease from subendothelial to subepithelial glomerular basement membrane (GBM), as would be expected if the GBM were itself the filter. The objective of this study was to obtain insights into the possible role of the GBM in protein retention by performing fundamental experimental and theoretical studies on the properties of three model gels. Solute partitioning and filtration through thin gels of a commercially available laminin-rich extracellular matrix, Matrigel, were measured using a polydisperse polysaccharide tracer molecule, Ficoll 70. Solute partitioning into laminin gels and lens basement membrane (LBM) were measured using Ficoll 70. A novel model of a laminin gel was numerically simulated, as well as a mixed structure-random-fiber model for LBM. Experimental partitioning was predicted by numerical simulations. Sieving coefficients through thin gels of Matrigel were size dependent and strongly flux dependent. The observed flux dependence arose from compression of the gel in response to the applied pressure. Gel compression may alter solute partitioning into extracellular matrix at physiologic pressures present in the glomerular capillary. This suggests a physical mechanism coupling podocyte structure to permeability characteristics of the GBM. PMID:19587146

  16. [Clinical experience of automated double filtration plasmapheresis].

    PubMed

    Lee, C T; Chuang, F R; Hsu, K T; Lam, K K; Liao, S C; Liu, C C; Chen, J B; Jang, S W; Chien, Y S; Pan, H H

    1996-12-01

    Double filtration plasmapheresis, one kind of fractionation plasmapheresis, was developed from membrane type plasmapheresis to remove only the pathogen and return the normal protein back to the patient. We started our automated double filtration plasmapheresis since December 1993. There were 13 patients who received one hundred treatments totally during one year period. And they are myasthenia gravis (8 patients); acute inflammatory demyelinating polyneuropathy (1 patient), multiple myeloma (1 patient); acquired factor VIII inhibitor (1 patient); autoimmune hemolytic anemia (1 patient); systemic lupus erythematous (1 patient). Technically double filtration plasmapheresis is easy to perform and time-saving. It also makes necessity of replacement fluid less frequent. Incidence of complication is rare, and this includes hypotension 2%, palpitation 1%, headache 1%, hemolysis 4%, air emboli 1%, high secondary pressure 2%, and no motality during our treatment. Clinical response is documented in cases of myasthenia gravis; acute inflammatory demyelinating polyneuropathy and acquired factor VIII inhibitor in our study. In conclusion, double filtration plasmapheresis is a time-saving, convenient, and safe therapeutic modality with rare complication. Because its effectiveness on limited kinds of diseases and costs relatively high price, thus plasmapheresis should be used in selected cases and treat aggressively if indicated.

  17. Contamination control through filtration of microorganisms

    NASA Technical Reports Server (NTRS)

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

    1972-01-01

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

  18. DEMONSTRATION BULLETIN: MEMBRANE FILTRATION - SBP TECHNOLOGIES, INC.

    EPA Science Inventory

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

  19. Fluorescent biodegradable PLGA particles with narrow size distributions: preparation by means of selective centrifugation.

    PubMed

    Gaumet, Marie; Gurny, Robert; Delie, Florence

    2007-09-05

    Size is the most studied parameter in the field of nanoparticle characterization but few studies have been performed on biodegradable particles with well-defined sizes. The aim of this work was to prepare fluorescent biodegradable polymeric particles having well-defined sizes and well-characterized surface properties. Poly(D,L-lactide-co-glycolide acid) particles were prepared by the emulsion evaporation process. Filtration and centrifugation were used to produce particle fractions in the narrow size range from polydispersed batches, and the efficiency of separation was compared. Selective centrifugation allowed for the preparation of five classes of particles having narrow size distribution (0.1, 0.3, 0.6, 1 and 2 microm). Particles were characterized in terms of size distribution, surface morphology, charge, residual surfactant and hydrophilicity. The results showed similar surface properties for all the batches. 3,3'-Dioctadecyloxacarbo-cyanine perchlorate has been successfully incorporated as a fluorescent dye and its ability to remain associated with the particles during cell culture experiments has been proven. Such particles may be used as an adequate tool for studying cellular uptake.

  20. [Rapid centrifugation assay standarization for dengue virus isolation].

    PubMed

    Palomino, Miryam; Gutierrez, Victoria; Salas, Ramses

    2010-03-01

    The plate centrifugation assay was standardized for dengue virus isolation from serum samples. C6/36-HT cells were used determining the optimal values for centrifugation spin speed, inoculum, sera dilution, and incubation time. Then, 22 positive serum samples with viral isolation and viral strains of the four reference dengue virus serotypes were tested simultaneously by the standardized plate centrifugation method and the conventional tube culture. The isolations were typified by indirect immunofluorescent test using monoclonal antibodies. The plate centrifugation method was optimized to 200 μL of inoculum, dilution of sera 1/20, centrifugation speed at 1600 rpm/30 min, and sensitivity of 95,5% after 5 days post-inoculation. We concluded that the plate centrifugation method increased dengue virus isolation, with a significant reduction of the time of isolation for dengue virus.

  1. Laminar flow effects in the coil planet centrifuge

    NASA Technical Reports Server (NTRS)

    Herrmann, F. T.

    1984-01-01

    The coil planet centrifuge designed by Ito employs flow of a single liquid phase, through a rotating coiled tube in a centrifugal force field, to provide a separation of particles based on sedimentation rates. Mathematical solutions are derived for the linear differential equations governing particle behavior in the coil planet centrifuge device. These solutions are then applied as the basis of a model for optimizing particle separations.

  2. Modeling Platform Dynamics and Physiological Response to Short Arm Centrifugation

    DTIC Science & Technology

    1994-03-01

    parametric design study for a small radius centrifuge revealed such a centrifuge could fit on the NASA Space Shuttle and provide artificial gravity and...the heart are modelled as variable capacitances separated by one-way valves. The pulmonic and aortic valves are also modelled as one-way valves. The...1992 June. 10. Halstead, TW; Brown, AH; Fuller, CA; Oyama, J. Artificial gravity studies and design considerations for space station centrifuges

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

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

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

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

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

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

  5. Theory and experiments on centrifuge cratering

    NASA Astrophysics Data System (ADS)

    Schmidt, R. M.; Holsapple, K. A.

    1980-01-01

    Centrifuge experimental techniques provide possibilities for laboratory simulation of ground motion and cratering effects due to explosive loadings. The results of a similarity analysis for the thermomechanical response of a continuum show that increased gravity is a necessary condition for subscale testing when identical materials for both model and prototype are being used. The general similarity requirements for this type of subscale testing are examined both theoretically and experimentally. The similarity analysis is used to derive the necessary and sufficient requirements due to the general balance and jump equations and gives relations among all the scale factors for size, density, stress, body forces, internal energy, heat supply, heat conduction, heat of detonation, and time. Additional constraints due to specific choices of material constitutive equations are evaluated separately. The class of constitutive equations that add no further requirements is identified. For this class of materials, direct simulation of large-scale cratering events at small scale on the centrifuge is possible and independent of the actual constitutive equations. For a rate-independent soil it is shown that a small experiment at gravity g and energy E is similar to a large event at 1 G but with energy equal to g3E. Consequently, experiments at 500 G with 8 grams of explosives can be used to simulate a kiloton in the field. A series of centrifuge experiments was performed to validate the derived similarity requirements and to determine the practicality of applying the technique to dry granular soils having little or no cohesion. Ten shots using Ottawa sand at various gravities confirmed reproducibility of results in the centrifuge environment, provided information on particle size effects, and demonstrated the applicability of the derived similitude requirements. These experiments used 0.5-4 grams of pentaerythritol-tetranitrate (PETN) and 1.7 grams of lead-azide explosives. They

  6. Impeller blade design method for centrifugal compressors

    NASA Technical Reports Server (NTRS)

    Jansen, W.; Kirschner, A. M.

    1974-01-01

    The design of a centrifugal impeller with blades that are aerodynamically efficient, easy to manufacture, and mechanically sound is discussed. The blade design method described here satisfies the first two criteria and with a judicious choice of certain variables will also satisfy stress considerations. The blade shape is generated by specifying surface velocity distributions and consists of straight-line elements that connect points at hub and shroud. The method may be used to design radially elemented and backward-swept blades. The background, a brief account of the theory, and a sample design are described.

  7. Internal filtration, filtration fraction, and blood flow resistance in high- and low-flux dialyzers.

    PubMed

    Schneditz, Daniel; Zierler, Edda; Vanholder, Raymond; Eloot, Sunny

    2014-01-01

    It was the aim to examine the fluid flow in blood and dialysate compartments of highly permeable hollow fiber dialyzers where internal filtration contributes to solute removal but where excessive filtration bears a risk of cell activation and damage. Flow characteristics of high- (HF) and low-flux (LF) dialyzers were studied in lab-bench experiments using whole bovine blood. Measurements obtained under different operating conditions and under zero net ultrafiltration were compared to theoretical calculations obtained from a mathematical model. Experimental resistances in the blood compartment were within ±2% of those calculated from the model when dialysate was used as a test fluid. With whole blood, the experimental resistances in the blood compartment were only 81.8 ± 2.8% and 83.7 ± 4.3% of those calculated for the LF and HF dialyzer, respectively. Surprisingly, measured blood flow resistance slightly but significantly decreased with increasing flow rate (p < 0.001). Mathematical modeling confirmed this decrease both in LF and HF dialyzers which was accompanied by a concomitant decrease in internal filtration fraction, while overall internal filtration increased. The increase in internal filtration when increasing blood flow is associated with a beneficial reduction in internal filtration fraction. Concerns of increased hemoconcentration when increasing blood flow therefore appear to be unwarranted.

  8. Autobalancing and FDIR for a space-based centrifuge prototype

    NASA Technical Reports Server (NTRS)

    Wilson, Edward; Mah, Robert W.

    2005-01-01

    This report summarizes centrifuge-related work performed at the Smart Systems Research Laboratory at NASA Ames Research Center's Computational Sciences Division from 1995 through 2003. The goal is to develop an automated system that will sense an imbalance (both static and dynamic3) in a centrifuge and issue control commands to drive counterweights to eliminate the effects of the imbalance. This autobalancing development began when the ISS centrifuge design was not yet finalized, and was designed to work with the SSRL Centrifuge laboratory prototype, constructed in 1993-1995. Significant differences between that prototype and the current International Space Station (ISS) Centrifuge design are that: the spin axis for the SSRL Centrifuge prototype can translate freely in x and y, but not wobble, whereas the ISS centrifuge spin axis has 3 translational and two rotational degrees of freedom, supported by a vibration 34. The imbalance sensors are strained gauges both in the rotor and the stator, measuring the imbalance forces, whereas the ISS centrifuge uses eddy current displacement sensors to measure the displacements resulting from imbalance. High fidelity autobalancing and FDIR systems (for both counterweights and strain gauges) are developed and tested in MATLAB simulation, for the SSRL Centrifuge configuration. Hardware implementation of the autobalancing technology was begun in 1996, but was terminated due to lack of funding. The project lay dormant until 2001-2002 when the FDIR capability was added.

  9. Effects of centrifugation on gonadal and adrenocortical steroids in rats

    NASA Technical Reports Server (NTRS)

    Kakihana, R.; Butte, J. C.

    1980-01-01

    Many endocrine systems are sensitive to external changes in the environment. Both the pituitary adrenal and pituitary gonadal systems are affected by stress including centrifugation stress. The effect of centrifugation on the pituitary gonadal and pituitary adrenocortical systems was examined by measuring the gonadal and adrenal steroids in the plasma and brain following different duration and intensity of centrifugation stress in rats. Two studies were completed and the results are presented. The second study was carried out to describe the developmental changes of brain, plasma and testicular testosterone and dihydrotestosterone in Sprague Dawley rats so that the effect of centrifugation stress on the pituitary gonadal syatem could be better evaluated in future studies.

  10. 77 FR 9273 - USEC Inc. (American Centrifuge Lead Cascade Facility and American Centrifuge Plant); Direct...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-02-16

    ... American Centrifuge Operating, LLC (ACO), pursuant to Sections 161(b), 161(i), 161(o) and 184 of the Atomic... that due to uncertainty, it appears that the date for completion of activities associated with the sub... be completed. IV Accordingly, pursuant to Sections 161b, 161i, 161o, and 184 of the Atomic Energy...

  11. Development of a 3D circular microfluidic centrifuge for the separation of mixed particles by using their different centrifuge times

    NASA Astrophysics Data System (ADS)

    Jeon, H. J.; Kim, D. I.; Kim, M. J.; Nguyen, X. D.; Park, D. H.; Go, J. S.

    2015-11-01

    This paper presents a circular microfluidic centrifuge with two inlets and two outlets to separate mixed microparticles with a specially designed sample injection hole. To separate the mixed particles, it uses a rotational flow, generated in a chamber by counter primary flows in the microchannels. The shape and sizes of the circular microfluidic centrifuge have been designed through numerical evaluation to have a large relative centrifugal force. The difference of centrifuge times of the mixed particles of 1 μm and 6 μm was determined to be 8.2 s at an inlet Reynolds number of 500 and a sample Reynolds number of 20. In the experiment, this was measured to be about 10 s. From the separation of the two polymer particles analogous to the representative sizes of platelets and red blood cells, the circular microfluidic centrifuge shows a potential to separate human blood cells size-selectively by using the difference of centrifuge times.

  12. Filtration Combustion in Smoldering and SHS

    NASA Technical Reports Server (NTRS)

    Matkowsky, Bernard

    1999-01-01

    Smolder waves and SHS (self-propagating high-temperature synthesis) waves are both examples of filtration combustion waves propagating in porous media. Smoldering combustion is important for the study of fire safety. Smoldering itself can cause damage, its products are toxic and it can also lead to the more dangerous gas phase combustion which corresponds to faster propagation at higher temperatures. In SHS, a porous solid sample, consisting of a finely ground powder mixture of reactants, is ignited at one end. A high temperature thermal wave, having a frontal structure, then propagates through the sample converting reactants to products. The SHS technology appears to enjoy a number of advantages over the conventional technology, in which the sample is placed in a furnace and "baked" until it is "well done". The advantages include shorter synthesis times, greater economy, in that the internal energy of the reactions is employed rather than the costly external energy of the furnace, purer products, simpler equipment and no intrinsic limitation on the size of the sample to be synthesized, as exists in the conventional technology. When delivery of reactants through the pores to the reaction site is an important aspect of the combustion process, it is referred to as filtration combustion. The two types of filtration combustion have a similar mathematical formulation, describing the ignition, propagation and extinction of combustion waves in porous media. The goal in each case, however, is different. In smoldering the desired goal is to prevent propagation, whereas in SHS the goal is to insure propagation of the combustion wave, leading to the synthesis of desired products. In addition, the scales in the two areas of application differ. Smoldering generally occurs at lower temperatures and propagation velocities than in SHS. Nevertheless, the two applications have much in common, so that what is learned in one application can be used to advantage in the other. We have

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

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

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

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

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

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

  15. 3. View southeast of northwest corner of filtration bed. Laboratory ...

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

    3. View southeast of northwest corner of filtration bed. Laboratory building is at center right of photograph. East rock appears directly behind the laboratory building. - Lake Whitney Water Filtration Plant, Filtration Plant, South side of Armory Street between Edgehill Road & Whitney Avenue, Hamden, New Haven County, CT

  16. 40 CFR 141.174 - Filtration sampling requirements.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... PROGRAMS (CONTINUED) NATIONAL PRIMARY DRINKING WATER REGULATIONS Enhanced Filtration and Disinfection... water system subject to the requirements of this subpart that provides conventional filtration treatment... 40 Protection of Environment 24 2012-07-01 2012-07-01 false Filtration sampling requirements....

  17. 40 CFR 141.174 - Filtration sampling requirements.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... PROGRAMS (CONTINUED) NATIONAL PRIMARY DRINKING WATER REGULATIONS Enhanced Filtration and Disinfection... water system subject to the requirements of this subpart that provides conventional filtration treatment... 40 Protection of Environment 23 2014-07-01 2014-07-01 false Filtration sampling requirements....

  18. 40 CFR 141.71 - Criteria for avoiding filtration.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

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

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

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

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

  20. 40 CFR 141.174 - Filtration sampling requirements.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

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

  1. 40 CFR 141.71 - Criteria for avoiding filtration.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

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

  2. 40 CFR 141.174 - Filtration sampling requirements.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... PROGRAMS (CONTINUED) NATIONAL PRIMARY DRINKING WATER REGULATIONS Enhanced Filtration and Disinfection... water system subject to the requirements of this subpart that provides conventional filtration treatment... 40 Protection of Environment 23 2011-07-01 2011-07-01 false Filtration sampling requirements....

  3. 15. View west of central corridor between filtration beds which ...

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

    15. View west of central corridor between filtration beds which are located to the left and right of the photograph. - Lake Whitney Water Filtration Plant, Filtration Plant, South side of Armory Street between Edgehill Road & Whitney Avenue, Hamden, New Haven County, CT

  4. 40 CFR 141.174 - Filtration sampling requirements.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... PROGRAMS (CONTINUED) NATIONAL PRIMARY DRINKING WATER REGULATIONS Enhanced Filtration and Disinfection... water system subject to the requirements of this subpart that provides conventional filtration treatment... 40 Protection of Environment 24 2013-07-01 2013-07-01 false Filtration sampling requirements....

  5. 40 CFR 141.71 - Criteria for avoiding filtration.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

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

  6. 40 CFR 141.71 - Criteria for avoiding filtration.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

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

  7. 16. View west from center of central corridor between filtration ...

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

    16. View west from center of central corridor between filtration beds which are located to the left and right of the photograph. - Lake Whitney Water Filtration Plant, Filtration Plant, South side of Armory Street between Edgehill Road & Whitney Avenue, Hamden, New Haven County, CT

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

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

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

  9. 40 CFR 141.71 - Criteria for avoiding filtration.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

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

  10. Membrane filtration technology for the metals fabrication industry

    SciTech Connect

    Peden, J.; Lindsey, T.

    1995-12-31

    Membrane filtration for separating contaminants from aqueous cleaning solutions based on molecular size, shape, and charge is described in this paper. Ultrafiltration is a pressure driven membrane filtration technique capable of producing high quality filtrate from wastewater. Three case studies are briefly described where ultrafiltration has been incorporated into the manufacturing process.

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

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

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

  12. Centrifugation of coal-derived liquids

    SciTech Connect

    Weintraub, Murray; Weiss, Milton L.; Akhtar, Sayeed

    1980-06-01

    The application of the continuous solid bowl centrifuge to the removal of solids from coal liquefaction products was investigated. The centrifuge removed from 23 to 88% of the input ash from 8 to 73% of the input organic benzene insolubles while flow rates, viscosities, and dam heights were varied. Viscosity ..mu.., effluent liquid rate Q/sub e/, and Ambler's geometric parameter ..sigma.. were graphically correlated with attained separations. The separation was relatively insensitive to the variables, as a 50-fold increase in Q/sub e//..sigma.. corresponded to a decrease in ash removal only from 84% to 60% and to a decrease in organic solids removal only from 77% to 22%. Organic solids removal was poorer and more erratic than ash removal because of the lesser density differences and greater size variability of the organics. Ancillary studies demonstrated that coal liquefaction products may behave as a Bingham Plastic fluid, and that this results in an absolute limit on the attainable solids separation. Additional studies showed that little difference in density may exist between the organic solids and liquids, and that effects of aging may threaten the validity of viscosity measurements.

  13. Some aversive characteristics of centrifugally generated gravity.

    NASA Technical Reports Server (NTRS)

    Altman, F.

    1973-01-01

    The effective weight of rats was manipulated by centrifugation. Two effective weight levels were obtained. In three escape avoidance conditions a lever press produced a change from a base level of 2.1 g to a response level of 1.1 g. In a punishment condition a response produced a change from a 1.1 g level to a 2.1 g level and in an extinction condition responses had no effect on the 2.1 g effective weight level present. All changes took 30 sec and were maintained for an additional 10 sec before a return to base level was initiated. When responses occurred closer together than the 40 sec, they delayed the return to base level by 40 sec. This 40 sec interval is referred to as response-contingent-time. The response rate and amount of response-contingent-time served as the data. The results confirmed previous data that centrifugation is aversive. The results are interpreted as indicating that the aversiveness is attributable to the increase in effective weight, and that rats can discriminate the different angular velocity-radius of rotation combinations used.

  14. Experimental Investigation of Centrifugal Compressor Stabilization Techniques

    NASA Technical Reports Server (NTRS)

    Skoch, Gary J.

    2003-01-01

    Results from a series of experiments to investigate techniques for extending the stable flow range of a centrifugal compressor are reported. The research was conducted in a high-speed centrifugal compressor at the NASA Glenn Research Center. The stabilizing effect of steadily flowing air-streams injected into the vaneless region of a vane-island diffuser through the shroud surface is described. Parametric variations of injection angle, injection flow rate, number of injectors, injector spacing, and injection versus bleed were investigated for a range of impeller speeds and tip clearances. Both the compressor discharge and an external source were used for the injection air supply. The stabilizing effect of flow obstructions created by tubes that were inserted into the diffuser vaneless space through the shroud was also investigated. Tube immersion into the vaneless space was varied in the flow obstruction experiments. Results from testing done at impeller design speed and tip clearance are presented. Surge margin improved by 1.7 points using injection air that was supplied from within the compressor. Externally supplied injection air was used to return the compressor to stable operation after being throttled into surge. The tubes, which were capped to prevent mass flux, provided 9.3 points of additional surge margin over the baseline surge margin of 11.7 points.

  15. Centrifugally Stimulated Exospheric Ion Escape at Mercury

    NASA Technical Reports Server (NTRS)

    Delcourt, Dominique; Seki, K.; Terada, N.; Moore, Thomas E.

    2012-01-01

    We investigate the transport of ions in the low-altitude magnetosphere magnetosphere of Mercury. We show that, because of small spatial scales, the centrifugal effect due to curvature of the E B drift paths can lead to significant particle energization in the parallel direction. We demonstrate that because of this effect, ions with initial speed smaller than the escape speed such as those produced via thermal desorption can overcome gravity and escape into the magnetosphere. The escape route of this low-energy exosphere originating material is largely controlled by the magnetospheric convection rate. This escape route spreads over a narrower range of altitudes when the convection rate increases. Bulk transport of low-energy planetary material thus occurs within a limited region of space once moderate magnetospheric convection is established. These results suggest that, via release of material otherwise gravitationally trapped, the E B related centrifugal acceleration is an important mechanism for the net supply of plasma to the magnetosphere of Mercury.

  16. Wave Augmented Diffusers for Centrifugal Compressors

    NASA Technical Reports Server (NTRS)

    Paxson, Daniel E.; Skoch, Gary J.

    1998-01-01

    A conceptual device is introduced which would utilize unsteady wave motion to slow and turn flows in the diffuser section of a centrifugal compressor. The envisioned device would substantially reduce the size of conventional centrifugal diffusers by eliminating the relatively large ninety degree bend needed to turn the flow from the radial/tangential to the axial direction. The bend would be replaced by a wall and the flow would instead exit through a series of rotating ports located on a disk, adjacent to the diffuser hub, and fixed to the impeller shaft. The ports would generate both expansion and compression waves which would rapidly transition from the hub/shroud (axial) direction to the radial/tangential direction. The waves would in turn induce radial/tangential and axial flow. This paper presents a detailed description of the device. Simplified cycle analysis and performance results are presented which were obtained using a time accurate, quasi-one-dimensional CFD code with models for turning, port flow conditions, and losses due to wall shear stress. The results indicate that a periodic wave system can be established which yields diffuser performance comparable to a conventional diffuser. Discussion concerning feasibility, accuracy, and integration follow.

  17. Development of an implantable centrifugal blood pump.

    PubMed

    Goldstein, A H; Pacella, J J; Trumble, D R; Clark, R E

    1992-01-01

    The efficacy of centrifugal pumps for short-term (0-30 days) ventricular support has been widely reported and favorably compared with pulsatile systems. A small, durable, implantable centrifugal blood pump is being developed for medium-term use (up to 6 months). The pump is based on the Medtronic Hemadyne system that has existed in multiple forms over the past 30 years. The pump is approximately the size of a tennis ball, weighs 240 g, and is comprised of a 2.5 cm plastic impeller driven by a radially coupled brushless DC motor. In vitro hydraulic performance was recorded over a wide range of flow conditions on a mock circulatory loop. The pump generated 7 L/min flow against an afterload of 100 mmHg pressure, with a maximum power draw of 10.4 watts. Pulsatile flow was preserved when placed in conjunction with a simulated left ventricle. In vivo testing was performed in 10 healthy sheep for 10-292 hr. Heparin was used to facilitate cannulation, and no anticoagulation was administered after pump implantation. Blood chemistries reflecting hematologic, pulmonary, renal, and hepatic functions were recorded and demonstrated no adverse effects with normal pump operation. Complications were related to kinking of blood conduits and thrombus formation within the cannulae. These results are encouraging and warrant further studies to prove feasibility of this pump as a medium-term implantable ventricular assist device.

  18. Ultrasonic filtration of industrial chemical solutions

    NASA Technical Reports Server (NTRS)

    Cosma, T.

    1974-01-01

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

  19. Optimal filtration of the atmospheric parameters profiles

    NASA Technical Reports Server (NTRS)

    Zuev, V. E.; Glazov, G. N.; Igonin, G. M.

    1986-01-01

    The idea of optimal Marcovian filtration of fluctuating profiles from lidar signals is developed but as applied to a double-frequency sounding which allows the use of large cross sections of elastic scattering and correct separation of the contributions due to aerosol and Rayleigh scatterings from the total lidar return. The filtration efficiency is shown under different conditions of sounding using a computer model. The accuracy of restituted profiles (temperature, pressure, density) is determined by the elements of a posteriori matrix K. The results obtained allow the determination of the lidar power required for providing the necessary accuracy of restitution of the atmospheric parameter profiles at chosen wavelengths of sounding in the ultraviolet and visible range.

  20. Cellular proliferation after experimental glaucoma filtration surgery

    SciTech Connect

    Jampel, H.D.; McGuigan, L.J.; Dunkelberger, G.R.; L'Hernault, N.L.; Quigley, H.A.

    1988-01-01

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

  1. Diatomite releases silica during spirit filtration.

    PubMed

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

    2014-09-15

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

  2. Power transmission mechanism equipped with fluid and centrifugal clutch

    SciTech Connect

    Tamura, K.; Takeshita, S.; Fukunaga, T.

    1986-12-30

    This patent describes a power transmission mechanism equipped with a fluid coupling, an input shaft thereof interconnected to a power source being interconnected through the fluid coupling to an output shaft, and the output shaft being interconnected to a forward-rearward changeover mechanism including a speed changer. It is characterized in that the fluid coupling includes a shell, an impeller in the shell and a centrifugal clutch means in the shell for engaging the impeller and for driving the impeller when the shell is rotated by the input shaft at a speed above idle speed and for disengaging the impeller and the driving of the impeller when the shell is rotated by the input shaft at the idle speed. A turbine is included in the shell for standing idle in the shell when the centrifugal clutch means is disengaged and for drive by the impeller when the centrifugal clutch means is engaged and for driving the output shaft. The centrifugal clutch means comprises a support member fixed to the shell, a centrifugal shoe mounted on the support member for radial movement outwardly of the support member by centrifugal force and radial movement inwardly toward the support member. It also comprises spring means for moving the shoe inwardly toward the support member when the shell is rotated at idle speed, a cylindrical casing fixed to the impeller radially outward from the shoe and having an engaging surface for engagement by the centrifugal shoe when the shell is rotated at a speed above idle speed and the centrifugal shoe is moved radially outward by centrifugal force. The forward-rearward changeover mechanism, including the speed changer, is driven by the turbine when the centrifugal clutch means is engaged with the engaging surface and standing idle when the centrifugal clutch means is disengaged from the engaging surface and the turbine is standing idle.

  3. Solving filtrate invasion with clay-water base mud systems

    SciTech Connect

    Hassen, B.R.

    1982-11-01

    Addressing the problem of drilling fluid filtration damage to the permeability of formations, a technique has been developed which calculates filtration of drilling fluids under actual well conditions. Filtration volumes into a particular zone can now be estimated through use of a programmable calculator. This article outlines study results, specifically the types of filtration relationships derived, examples of model results and also potential applications of the system. Armed with the capabilities of this system, it becomes possible to reap the benefits of reduced filtrate invasion.

  4. High Efficiency Centrifugal Compressor for Rotorcraft Applications

    NASA Technical Reports Server (NTRS)

    Medic, Gorazd; Sharma, Om P.; Jongwook, Joo; Hardin, Larry W.; McCormick, Duane C.; Cousins, William T.; Lurie, Elizabeth A.; Shabbir, Aamir; Holley, Brian M.; Van Slooten, Paul R.

    2014-01-01

    The report "High Efficiency Centrifugal Compressor for Rotorcraft Applications" documents the work conducted at UTRC under the NRA Contract NNC08CB03C, with cost share 2/3 NASA, and 1/3 UTRC, that has been extended to 4.5 years. The purpose of this effort was to identify key technical barriers to advancing the state-of-the-art of small centrifugal compressor stages; to delineate the measurements required to provide insight into the flow physics of the technical barriers; to design, fabricate, install, and test a state-of-the-art research compressor that is representative of the rear stage of an axial-centrifugal aero-engine; and to acquire detailed aerodynamic performance and research quality data to clarify flow physics and to establish detailed data sets for future application. The design activity centered on meeting the goal set outlined in the NASA solicitation-the design target was to increase efficiency at higher work factor, while also reducing the maximum diameter of the stage. To fit within the existing Small Engine Components Test Facility at NASA Glenn Research Center (GRC) and to facilitate component re-use, certain key design parameters were fixed by UTRC, including impeller tip diameter, impeller rotational speed, and impeller inlet hub and shroud radii. This report describes the design effort of the High Efficiency Centrifugal Compressor stage (HECC) and delineation of measurements, fabrication of the compressor, and the initial tests that were performed. A new High-Efficiency Centrifugal Compressor stage with a very challenging reduction in radius ratio was successfully designed, fabricated and installed at GRC. The testing was successful, with no mechanical problems and the running clearances were achieved without impeller rubs. Overall, measured pressure ratio of 4.68, work factor of 0.81, and at design exit corrected flow rate of 3 lbm/s met the target requirements. Polytropic efficiency of 85.5 percent and stall margin of 7.5 percent were

  5. Fast Filtration of Bacterial or Mammalian Suspension Cell Cultures for Optimal Metabolomics Results

    PubMed Central

    Bordag, Natalie; Janakiraman, Vijay; Nachtigall, Jonny; González Maldonado, Sandra; Bethan, Bianca; Laine, Jean-Philippe; Fux, Elie

    2016-01-01

    The metabolome offers real time detection of the adaptive, multi-parametric response of the organisms to environmental changes, pathophysiological stimuli or genetic modifications and thus rationalizes the optimization of cell cultures in bioprocessing. In bioprocessing the measurement of physiological intracellular metabolite levels is imperative for successful applications. However, a sampling method applicable to all cell types with little to no validation effort which simultaneously offers high recovery rates, high metabolite coverage and sufficient removal of extracellular contaminations is still missing. Here, quenching, centrifugation and fast filtration were compared and fast filtration in combination with a stabilizing washing solution was identified as the most promising sampling method. Different influencing factors such as filter type, vacuum pressure, washing solutions were comprehensively tested. The improved fast filtration method (MxP® FastQuench) followed by routine lipid/polar extraction delivers a broad metabolite coverage and recovery reflecting well physiological intracellular metabolite levels for different cell types, such as bacteria (Escherichia coli) as well as mammalian cells chinese hamster ovary (CHO) and mouse myeloma cells (NS0).The proposed MxP® FastQuench allows sampling, i.e. separation of cells from medium with washing and quenching, in less than 30 seconds and is robustly designed to be applicable to all cell types. The washing solution contains the carbon source respectively the 13C-labeled carbon source to avoid nutritional stress during sampling. This method is also compatible with automation which would further reduce sampling times and the variability of metabolite profiling data. PMID:27438065

  6. Nanofiber filter media for air filtration

    NASA Astrophysics Data System (ADS)

    Raghavan, Bharath Kumar

    Nanofibers have higher capture efficiencies in comparison to microfibers in the submicron particle size range of 100-500 nm because of small fiber diameter and increased surface area of the fibers. Pressure drop across the filter increases tremendously with decrease in fiber diameter in the continuum flow regime. Nanofibers with fiber diameter less than 300 nm are in the slip flow regime as a consequence of which steep increase in pressure drop is considerably reduced due to slip effect. The outlet or inlet gases have broad range of particle size distribution varying from few micrometers to nanometers. The economic benefits include capture of a wide range of particle sizes in the gas streams using compact filters composed of nanofibers and microfibers. Electrospinning technique was used to successfully fabricate polymeric and ceramic nanofibers. The nanofibers were long, continuous, and flexible with diameters in the range of 200--300 nm. Nanofibers were added to the filter medium either by mixing microfibers and nanofibers or by directly electrospinning nanofibers as thin layer on the surface of the microfiber filter medium. Experimental results showed that either by mixing Nylon 6 nanofibers with B glass fibers or by electrospinning Nylon 6 nanofibers as a thin layer on the surface of the microfiber medium in the surface area ratio of 1 which is 0.06 g of nanofibers for 2 g of microfibers performed better than microfiber filter media in air filtration tests. This improved performance is consistent with numerical modeling. The particle loading on a microfibrous filter were studied for air filtration tests. The experimental and modeling results showed that both pressure drop and capture efficiency increased with loading time. Nanofiber filter media has potential applications in many filtration applications and one of them being hot gas filtration. Ceramic nanofibers made of alumina and titania nanofibers can withstand in the range of 1000°C. Ceramic nanofibers

  7. Filtration Combustion in Smoldering and SHS

    NASA Technical Reports Server (NTRS)

    Matkowsky, Bernard J.

    2001-01-01

    Smolder waves and SHS (self-propagating high-temperature synthesis) waves are both examples of filtration combustion waves propagating in porous media. Smoldering combustion is important for the study of fire safety. Smoldering itself can cause damage, its products are toxic and it can also lead to the more dangerous gas phase combustion which corresponds to faster propagation at higher temperatures. In SHS , a porous solid sample, consisting of a finely ground powder mixture of reactants, is ignited at one end. A high temperature thermal wave, having a frontal structure, then propagates through the sample converting reactants to products. The SHS technology appears to enjoy a number of advantages over the conventional technology, in which the sample is placed in a furnace and "baked" until it is "well done". The advantages include shorter synthesis times, greater economy, in that the internal energy of the reactions is employed rather than the costly external energy of the furnace, purer products, simpler equipment and no intrinsic limitation on the size of the sample to be synthesized as exists in the conventional technology. When delivery of reactants through the pores to the reaction site is an important aspect of the combustion process, it is referred to as filtration combustion. The two types of filtration combustion have a similar mathematical formulation, describing the ignition, propagation and extinction of combustion waves in porous media. The goal in each case, however, is different. In smoldering the desired goal is to prevent propagation, whereas in SHS the goal is to ensure propagation of the combustion wave, leading to the synthesis of desired products. In addition, the scales in the two areas of application differ. Smoldering generally occurs at lower temperatures and propagation velocities than in SHS nevertheless, the two applications have much in common so that what is learned fit make application can be used to advantage in the other. In porous

  8. Parameter Study of Melt Spun Polypropylene Fibers by Centrifugal Spinning

    DTIC Science & Technology

    2014-07-01

    including drawing, template synthesis, phase separation, self- assembly, and electrospinning . Most methods are only relevant on a laboratory scale...attention as an alternative to electrospinning , the most common nanofiber formation method. Fibers of low dielectric constants and insoluble polymers that...generally cannot be used in electrospinning can be produced through centrifugal spinning. The centrifugal spinning process has several key

  9. Coil planet centrifugation as a means for small particle separation

    NASA Technical Reports Server (NTRS)

    Herrmann, F. T.

    1983-01-01

    The coil planet centrifuge uses a centrifugal force field to provide separation of particles based on differences in sedimentation rates by flow through a rotating coiled tube. Three main separations are considered: (1) single phase fresh sheep and human erythrocytes, (2) single phase fixed heep and human erythrocytes, and (3) electrophoretically enhanced single phase fresh sheep and human erythrocytes.

  10. Centrifugal Barrel Finishing Of Turbine-Blade "Fir Trees"

    NASA Technical Reports Server (NTRS)

    Mandel, Johnny L.

    1990-01-01

    Modified centrifugal barrel-finishing machine imparts desired residual compressive stresses to "fir trees" of turbine blades. Centrifugal forces generate compressive stresses, which are transmitted to turbine blades through abrasive slurries in which suspended. Eliminates need for shot peening, rounding of edges and burrs caused by shot peening and, consequently, need for mass finishing operations to remove burrs. Improves surface finish of "fir trees".

  11. Treatment efficiency and filtration rate of a horizontal sand filtration system.

    PubMed

    Kompayak, U; Dejthai, T

    1990-01-01

    The purpose of this study was to establish acceptable criteria for a horizontal sand filtration (HSF) system that are suitable for the design of community water supply units in rural areas. Two laboratory scales of HSF were constructed and tested for their filtration rates and treatment efficiency in Visetchaicharn District of Angthong Province, Thailand. The main structure of both models was the same except for the lengths of the filtration column, i.e., 80 cm. in Model 1 and 100 cm. in Model 2. The results of treatment efficiency of both models were very satisfactory. The physical and chemical quality of the filtered water was within the standards for drinking water except for bacteria quality. The rates of filtration of Model 1 were slightly faster than those of Model 2 for both one and two meters of water level in the raw water column. The rates for both models were higher than the lower limit standards of the slow sand filtration system throughout the study.

  12. Filtration Efficiency of Functionalized Ceramic Foam Filters for Aluminum Melt Filtration

    NASA Astrophysics Data System (ADS)

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

    2017-02-01

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

  13. Bubble Eliminator Based on Centrifugal Flow

    NASA Technical Reports Server (NTRS)

    Gonda, Steve R.; Tsao, Yow-Min D.; Lee, Wenshan

    2004-01-01

    The fluid bubble eliminator (FBE) is a device that removes gas bubbles from a flowing liquid. The FBE contains no moving parts and does not require any power input beyond that needed to pump the liquid. In the FBE, the buoyant force for separating the gas from the liquid is provided by a radial pressure gradient associated with a centrifugal flow of the liquid and any entrained bubbles. A device based on a similar principle is described in Centrifugal Adsorption Cartridge System (MSC- 22863), which appears on page 48 of this issue. The FBE was originally intended for use in filtering bubbles out of a liquid flowing relatively slowly in a bioreactor system in microgravity. Versions that operate in normal Earth gravitation at greater flow speeds may also be feasible. The FBE (see figure) is constructed as a cartridge that includes two concentric cylinders with flanges at the ends. The outer cylinder is an impermeable housing; the inner cylinder comprises a gas-permeable, liquid-impermeable membrane covering a perforated inner tube. Multiple spiral disks that collectively constitute a spiral ramp are mounted in the space between the inner and outer cylinders. The liquid enters the FBE through an end flange, flows in the annular space between the cylinders, and leaves through the opposite end flange. The spiral disks channel the liquid into a spiral flow, the circumferential component of which gives rise to the desired centrifugal effect. The resulting radial pressure gradient forces the bubbles radially inward; that is, toward the inner cylinder. At the inner cylinder, the gas-permeable, liquid-impermeable membrane allows the bubbles to enter the perforated inner tube while keeping the liquid in the space between the inner and outer cylinders. The gas thus collected can be vented via an endflange connection to the inner tube. The centripetal acceleration (and thus the radial pressure gradient) is approximately proportional to the square of the flow speed and

  14. Supersonic rotation in the Maryland Centrifugal Experiment

    NASA Astrophysics Data System (ADS)

    Messer, Sarah

    The Maryland Centrifugal Experiment (MCX) has been built to study the confinement of supersonically-rotating plasmas and velocity shear stabilization of MHD instabilities. Theory predicts improved stability and confinement when a strong radial electric field is introduced into a magnetic-mirror geometry. The resulting radial currents establish a stable highly sheared plasma rotating at supersonic velocities in the azimuthal direction under the influence of J x B forces. This arrangement leads to increased confinement because the supersonic rotation creates an artificial radial gravity which draws the plasma away from the mirrors, closing the mirror loss cone. The large vφ shear stabilizes the plasma and enforces laminar flow. Based on these concepts, we have designed and constructed a machine to produce supersonically rotating highly-ionized plasmas. It typically does this by introducing a radial voltage of 7 kV in a magnetic-mirror geometry, 2 kG at the midplane and 19 kG at each mirror. MCX has completed its main construction phase and is acquiring data, here analyzed primarily in terms of a circuit model which infers plasma characteristics from the radial voltage across the plasma and the total radial current. The theory and simulations supporting the MCX centrifugal confinement scheme are presented here with the data and analysis from its first nine months of operation, including a description of basic plasma characteristics and evidence for both stability and confinement. Theory simulation, and initial experimental data all indicate that this centrifugal confinement scheme provides good stability and confinement at the temperatures and densities under study, as well as at the larger temperatures, fields, and dimensions expected for a fusion reactor. In particular, spectroscopic and circuit-model data indicate rotational velocities in MCX of up to 100 km/s, ion temperatures of approximately 30 eV, and ion densities upwards of 1020m-3. These parameters give

  15. 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

  16. Characterization of Filtration Scale-Up Performance

    SciTech Connect

    Daniel, Richard C.; Billing, Justin M.; Luna, Maria L.; Cantrell, Kirk J.; Peterson, Reid A.; Bonebrake, Michael L.; Shimskey, Rick W.; Jagoda, Lynette K.

    2009-03-09

    The scale-up performance of sintered stainless steel crossflow filter elements planned for use at the Pretreatment Engineering Platform (PEP) and at the Waste Treatment and Immobilization Plant (WTP) were characterized in partial fulfillment (see Table S.1) of the requirements of Test Plan TP RPP WTP 509. This test report details the results of experimental activities related only to filter scale-up characterization. These tests were performed under the Simulant Testing Program supporting Phase 1 of the demonstration of the pretreatment leaching processes at PEP. Pacific Northwest National Laboratory (PNNL) conducted the tests discussed herein for Bechtel National, Inc. (BNI) to address the data needs of Test Specification 24590-WTP-TSP-RT-07-004. Scale-up characterization tests employ high-level waste (HLW) simulants developed under the Test Plan TP-RPP-WTP-469. The experimental activities outlined in TP-RPP-WTP-509 examined specific processes from two broad areas of simulant behavior: 1) leaching performance of the boehmite simulant as a function of suspending phase chemistry and 2) filtration performance of the blended simulant with respect to filter scale-up and fouling. With regard to leaching behavior, the effect of anions on the kinetics of boehmite leaching was examined. Two experiments were conducted: 1) one examined the effect of the aluminate anion on the rate of boehmite dissolution and 2) another determined the effect of secondary anions typical of Hanford tank wastes on the rate of boehmite dissolution. Both experiments provide insight into how compositional variations in the suspending phase impact the effectiveness of the leaching processes. In addition, the aluminate anion studies provide information on the consequences of gibbsite in waste. The latter derives from the expected fast dissolution of gibbsite relative to boehmite. This test report concerns only results of the filtration performance with respect to scale-up. Test results for boehmite

  17. Centrifugal regulator for control of deployment rates of deployable elements

    NASA Technical Reports Server (NTRS)

    Vermalle, J. C.

    1980-01-01

    The requirements, design, and performance of a centrifugal regulator aimed at limiting deployment rates of deployable elements are discussed. The overall mechanism is comprised of four distinct functional parts in a machined housing: (1) the centrifugal brake device, which checks the payout of a deployment cable; (2) the reducing gear, which produces the spin rate necesary for the braking device; (3) the payout device, which allows the unwinding of the cable; and (4) the locking device, which prevents untimely unwinding. The centrifugal regulator is set into operation by a threshold tension of the cable which unlocks the mechanism and allows unwinding. The pulley of the windout device drives the centrifugal brake with the help of the reducing gear. The centrifugal force pushes aside weights that produce friction of the studs in a cylindrical housing. The mechanism behaved well at qualification temperature and vibrations.

  18. Infiltration of fibrous preform in the centrifugal force field

    SciTech Connect

    Nishida, Yoshinori; Shirayanagi, Itaru; Sakai, Yoshibumi; Tozawa, Yasuhisa

    1994-12-31

    The pressure to infiltrate molten aluminum into alumina short fiber preform was generated by centrifugal force, and the start pressure for the infiltration was measured. The fundamental equation of infiltration phenomenon was derived from the equation of the conservation of momentum of fluid flow in the porous media in the centrifugal force field. One-dimensional solution of the equation was obtained to discuss the characteristics of fluid flow in a centrifugal force field. It was made clear that centrifugal force is effective as a motive force to infiltrate molten metal into fibrous preform, the pressure distribution of molten metal in the preform is different from that predicted by D`Arcy`s law and the infiltration is enhanced by centrifugal force.

  19. Development of Centrifugal Contactor with High Reliability

    SciTech Connect

    Okamura, Nobuo; Takeuchi, Masayuki; Ogino, Hideki; Kase, Takeshi; Koizumi, Tsutomu

    2007-07-01

    In Japan Atomic Energy Agency (JAEA), an innovative centrifugal contactor system has been developed for a future reprocessing plant. It was confirmed that it had a higher extraction capacity through the uranium test already. But it was necessary that it had the higher mechanical reliability to be applied in a reprocessing plant. In this study, two types of driving units that use a ball bearing or a magnetic bearing have been developed for it. It was confirmed that they had enough abilities trough endurance tests. The driving unit with ball bearing could be operated continuously for 5000 hours that was equal to a term of an annual operation. It was found that it could be operated for a year without maintenance. JAEA will continue to improve them and select more advantageous one on the basis of economy and lifetime in near future. (authors)

  20. Implantable centrifugal pump with hybrid magnetic bearings.

    PubMed

    Bearnson, G B; Olsen, D B; Khanwilkar, P S; Long, J W; Sinnott, M; Kumar, A; Allaire, P E; Baloh, M; Decker, J

    1998-01-01

    Test methods and results of in vitro assessment of a centrifugal pump with a magnetically suspended impeller are provided. In vitro blood tests have been completed with a resulting normalized milligram index of hemolysis (NmIH) of 12.4 +/- 4.1, indicating that hemolysis is not a problem. Hydraulic characterization of the system with water has shown that a nominal pumping condition of 6 L/min at 100 mmHg was met at 2,200 rpm. Maximum clinically usable cardiac output is predicted be 10 L/min. The magnetic bearing supported impeller did not contact the housing and was shown to be stable under a variety of pumping conditions. The driving motor efficiency is 75% at the nominal condition. Finally, a description of the clinical version of the pump under development is provided.

  1. Centrifugal governor for internal combustion engines

    SciTech Connect

    Ohnishi, M.

    1986-09-23

    A centrifugal governor is described for use with an internal combustion engine which consists of: a control rack for regulating the quantity of fuel to be supplied to the engine; flyweights radially displaceable in response to the rotational speed of the engine; a tension lever pivotable through an angle dependent upon the amount of radial displacement of the flyweights; an idling spring for urging the tension lever against radially outward displacement of the flyweights; a torque cam having a cam surface determining a fuel increment to be applied at the start of the engine; a sensor lever having one end engaged by the control rack, and another end adapted to engage with the cam surface of the torque cam; a cancelling spring interposed between the torque cam and the tension lever; a control lever; a floating lever interlocking with the control lever; and spring force adjusting means arranged at one end of the idling spring.

  2. A modeling study of a centrifugal compressor

    SciTech Connect

    Popovic, P.; Shapiro, H.N.

    1998-12-31

    A centrifugal compressor, which is part of a chlorofluorocarbon R-114 chiller installation, was investigated, operating with a new refrigerant, hydrofluorocarbon R-236ea, a proposed alternative to R-114. A large set of R-236ea operating data, as well as a limited amount of R-114 data, were available for this study. A relatively simple analytical compressor model was developed to describe compressor performance. The model was built upon a thorough literature search, experimental data, and some compressor design parameters. Two original empirical relations were developed, providing a new approach to the compressor modeling. The model was developed in a format that would permit it to be easily incorporated into a complete chiller simulation. The model was found to improve somewhat on the quantitative and physical aspects of a compressor model of the same format found in the literature. It was found that the compressor model is specific to the particular refrigerant.

  3. Closed continuous-flow centrifuge rotor

    DOEpatents

    Breillatt, Jr., Julian P.; Remenyik, Carl J.; Sartory, Walter K.; Thacker, Louis H.; Penland, William Z.

    1976-01-01

    A blood separation centrifuge rotor having a generally parabolic core disposed concentrically and spaced apart within a housing having a similarly shaped cavity. Blood is introduced through a central inlet and into a central passageway enlarged downwardly to decrease the velocity of the entrant blood. Septa are disposed inside the central passageway to induce rotation of the entrant blood. A separation chamber is defined between the core and the housing wherein the whole blood is separated into red cell, white cell, and plasma zones. The zones are separated by annular splitter blades disposed within the separation chamber. The separated components are continuously removed through conduits communicating through a face seal to the outside of the rotor.

  4. [Hemodynamic analysis of a centrifugal blood pump].

    PubMed

    Wang, Yang; Yang, Ming; Xu, Zihao; Zhuang, Xiaoqi; Li, Qilei; Xu, Liang

    2015-01-01

    This paper built the mathematical model of a centrifugal blood pump, which was designed by ourselves, combined it with that of the human cardiovascular system and simulated the coupling system using Matlab. Then we set up the experiment platform, linked the blood pump to mock human cardiovascular system in case of three-stage heart failure, and measured aortic pressure and flow under different speed. The comparison between experiment results and simulation results not only indicates the coupling model is correct and the blood pump works well, but also shows that with the increase of blood pump speed, the pulsation of aortic pressure and flow will be reduced, this situation will affect the structure and function of blood vessels.

  5. Numerical simulation of centrifugal casting of pipes

    NASA Astrophysics Data System (ADS)

    Kaschnitz, E.

    2012-07-01

    A numerical simulation model for the horizontal centrifugal pipe casting process was developed with the commercial simulation package Flow3D. It considers - additionally to mass, energy and momentum conservation equations and free surface tracking - the fast radial and slower horizontal movement of the mold. The iron inflow is not steady state but time dependent. Of special importance is the friction between the liquid and the mold in connection with the viscosity and turbulence of the iron. Experiments with the mold at controlled revolution speeds were carried out using a high-speed camera. From these experiments friction coefficients for the description of the interaction between mold and melt were obtained. With the simulation model, the influence of typical process parameters (e.g. melts inflow, mold movement, melt temperature, cooling media) on the wall thickness of the pipes can be studied. The comparison to results of pipes from production shows a good agreement between simulation and reality.

  6. Rotordynamic forces on centrifugal pump impellers

    NASA Technical Reports Server (NTRS)

    Franz, R.; Arndt, N.; Caughey, T. K.; Brennen, C. E.; Acosta, A. J.

    1987-01-01

    The asymmetric flow around an impeller in a volute exerts a force upon the impeller. To study the rotordynamic force on an impeller which is vibrating around its machine axis of rotation, the impeller, mounted on a dynamometer, is made to whirl in a circular orbit within the volute. The measured force is expressed as the sum of a steady radial force and an unsteady force due to the eccentric motion of the impeller. These forces were measured in separate tests on a centrifugal pump with radically increased shroud clearance, a two-dimensional impeller, and an impeller with an inducer, the impeller of the HPOTP (High Pressure Oxygen Turbopump) of the SSME (Space Shuttle Main Engine). In each case, a destabilizing force was observed over a region of positive whirl.

  7. Reciprocating flow-based centrifugal microfluidics mixer

    NASA Astrophysics Data System (ADS)

    Noroozi, Zahra; Kido, Horacio; Micic, Miodrag; Pan, Hansheng; Bartolome, Christian; Princevac, Marko; Zoval, Jim; Madou, Marc

    2009-07-01

    Proper mixing of reagents is of paramount importance for an efficient chemical reaction. While on a large scale there are many good solutions for quantitative mixing of reagents, as of today, efficient and inexpensive fluid mixing in the nanoliter and microliter volume range is still a challenge. Complete, i.e., quantitative mixing is of special importance in any small-scale analytical application because the scarcity of analytes and the low volume of the reagents demand efficient utilization of all available reaction components. In this paper we demonstrate the design and fabrication of a novel centrifugal force-based unit for fast mixing of fluids in the nanoliter to microliter volume range. The device consists of a number of chambers (including two loading chambers, one pressure chamber, and one mixing chamber) that are connected through a network of microchannels, and is made by bonding a slab of polydimethylsiloxane (PDMS) to a glass slide. The PDMS slab was cast using a SU-8 master mold fabricated by a two-level photolithography process. This microfluidic mixer exploits centrifugal force and pneumatic pressure to reciprocate the flow of fluid samples in order to minimize the amount of sample and the time of mixing. The process of mixing was monitored by utilizing the planar laser induced fluorescence (PLIF) technique. A time series of high resolution images of the mixing chamber were analyzed for the spatial distribution of light intensities as the two fluids (suspension of red fluorescent particles and water) mixed. Histograms of the fluorescent emissions within the mixing chamber during different stages of the mixing process were created to quantify the level of mixing of the mixing fluids. The results suggest that quantitative mixing was achieved in less than 3 min. This device can be employed as a stand alone mixing unit or may be integrated into a disk-based microfluidic system where, in addition to mixing, several other sample preparation steps may be

  8. Method and centrifugal apparatus for slurry testing

    SciTech Connect

    Tuzson, J.J.

    1984-04-17

    In accordance with the centrifugal erosion testing method of the invention, a material specimen is rotated with a flat surface facing the direction of rotation and a narrow stream of an abrasive particle slurry is concurrently flowed at a preselected rate in a radial direction across the flat surface, the rotating step being at sufficiently high angular velocity to urge the abrasive particles by Coriolis acceleration into a compacted mass against the flat surface and erode material therefrom by scouring type action as the particles flow radially outward. The rotating and flowing steps are continued for a sufficient preselected duration to erode material to a measurable depth, and the depth to which the flat surface is worn by the abrasive particles is measured as an indication of the erosion resistance of the specimen material. The centrifugal slurry erosion testing apparatus includes a rotatable cylindrical vessel into the interior of which the abrasive slurry is fed and a specimen holder extending radially from the vessel having a cavity for receiving the specimen and a radial slurry flow passage communicating with the interior of the vessel. One of the radial passage longitudinal walls is defined by the flat surface of the specimen. Preferably the specimen holder comprises mating semicylindrical halves one of which has a specimen-receiving cavity in its abutting surface and the other has a narrow rectangular-in-cross section groove in its abutting surface which communicates with the interior of the vessel and together with the flat surface of the specimen defines the radial slurry flow passage. The mating semicylindrical halves are enclosed by a sleeve having an annular rim disposed interiorly of the vessel to prevent radially outward movement of the specimen holder.

  9. Transfer and transport of aluminum in filtration unit.

    PubMed

    Wen-dong, Wang; Hong-wei, Yang; Hua-zhang, Zhao; Zhan-peng, Jiang

    2007-01-01

    Aluminum salt coagulants were used prevalently in various water works. In this article, the effects of filtration on residual aluminum concentration and species distribution were researched by determining the concentration of different aluminum species before and after single layer filter, double layer filter, and membrane filtration units. In the research, size exclusion chromatography (SEC) was used to separate colloidal and soluble aluminum, ion exchange chromatography (IEC) was used to separate organic and inorganic aluminum, and inductivity coupled plasma-atomic emission spectrometry (ICP-AES) was used to determine the aluminum concentration. The results showed that the rapid filtration process had the ability of removing residual aluminum from coagulant effluent water, and that double layer filtration was more effective in residual aluminum removal than single layer filtration, while nano filtration was more effective than micro filtration. It was found that when the residual aluminum concentration was below 1 mg/L in sediment effluent, the residual aluminum concentration in treated water was above 0.2 mg/L. The direct rapid filtration process mainly removed the suspended aluminum. The removal of soluble and colloidal aluminum was always less than 10% and the natural small particles that adsorbed the amount of soluble or small particles aluminum on their surface were difficult to be removed in this process. Micro filtration and nano filtration were good technologies for removing aluminum; the residual aluminum concentration in the effluent was less than 0.05 mg/L.

  10. Electrospinning of nanofibers for filtration media

    NASA Astrophysics Data System (ADS)

    Park, Hyoungjun

    Since particulate impurity is regarded as the primary cause of lung diseases, purification of air has been a crucial issue. Filtration is the most conventional method to obtain clean air, whereby particulate matter is collected on a fibrous media. The use of fibrous filters is prevalent because of their high filtration efficiency and low pressure drop. Fibrous filters were fabricated via the electrospinning process which can be used to produce continuous submicron-diameter sized fibers. Polyacrylonitrile (PAN) nanofibers with a mean fiber diameter of 224 nm were electrospun to form fibermats. Filtration tests on fibermats of PAN were conducted to confirm that filters of thinner fibers result in higher collection efficiencies and lower pressure drops than that of thicker fibers as predicted by the theoretical filtration mechanism. Results showed that electrospun PAN nanofibermats had a superior quality factor of 0.067+/-0 compared to 0.031+/-0.001 by the current state-of-the-art microfiber-based high particulate air (HEPA) filtration media. The verified theory implies that nanofibermats of other types of materials could also be considered as promising filtration media since filtration performance is independent of the material used. As materials for advanced next-generation filtration media, ceramics are favored over polymeric materials due to their robustness against environmental factors such as ultraviolet rays, abrasive particles, and high temperature all of which degrade and damage the fibrous structure. Amidst various ceramic materials, the anatase phase of TiO2 was selected due to its mechanical property and versatility as a photocatalyst and microwave-absorbing material. Anatase TiO2 fibers were fabricated by electrospinning followed by heat treatment at 500°C for 3 hours. However, early precipitation or gelation of the organic solvent-based TiO2 sol posed a practical challenge in the sample preparation. In order to enhance stability of the precursor sol, a

  11. Investigation of Microgranular Adsorptive Filtration System

    NASA Astrophysics Data System (ADS)

    Cai, Zhenxiao

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

  12. Tropic Responses of Phycomyces Sporangiophores to Gravitational and Centrifugal Stimuli

    PubMed Central

    Dennison, David S.

    1961-01-01

    A low-speed centrifuge was used to study the tropic responses of Phycomyces sporangiophores in darkness to the stimulus of combined gravitational and centrifugal forces. If this stimulus is constant the response is a relatively slow tropic reaction, which persists for up to 12 hours. The response is accelerated by increasing the magnitude of the gravitational-centrifugal force. A wholly different tropic response, the transient response, is elicited by an abrupt change in the gravitational-centrifugal stimulus. The transient response has a duration of only about 6 min. but is characterized by a high bending speed (about 5°/min.). An analysis of the distribution of the transient response along the growing zone shows that the active phase of the response has a distribution similar to that of the light sensitivity for the light-growth and phototropic responses. Experiments in which sporangiophores are centrifuged in an inert dense fluid indicate that the sensory mechanism of the transient response is closely related to the physical deformation of the growing zone caused by the action of the gravitational-centrifugal force on the sporangiophore as a whole. However, the response to a steady gravitational-centrifugal force is most likely not connected with this deformation, but is probably triggered by the shifting of regions or particles of differing density relative to one another inside the cell. PMID:13721903

  13. Centrifugal Casting Features/Metallurgical Characterization of Aluminum Alloys

    SciTech Connect

    Chirita, G.; Soares, D.; Cruz, D.; Silva, F. S.; Stefanescu, I.

    2008-02-15

    This paper deals with the study of centrifugal effects on aluminium castings under high G values. Most of the studies in this domain (FGMs obtained by centrifugal casting) deal with functionally graded composites reinforced with a solid phase such as silicon particles or others. However, in this study it will be shown that unreinforced aluminium alloys may be significantly influenced by the centrifugal effect and that functionally graded castings are also obtained. It has been observed that the centrifugal effect may increase in some alloys, depending on the relative position in the castings, the rupture strength by approx. 50%, and rupture strain by about 300%, as compared to the gravity casting technique. The Young's modulus may also increase by about 20%. It has also been reported that in vertical centrifugal castings there are mainly three aspects that affect the components thus obtained, namely: fluid dynamics; vibration (inherent to the system); and centrifugal force. These features have a different effect on the castings depending on the aluminium alloy. In this paper, an analysis of the most important effects of the centrifugal casting process on metallurgical features is conducted. A solidification characterization at several points along the mould will be made in order to have an accurate idea of both the fluid dynamics inside the mould during the casting and the solidification behavior in different parts of the component. These two analyses will be related to the metallurgical properties (phase distribution; SDAS; eutectic silicon content and shape, pores density and shape) along the component and mainly along the direction of the centrifugal pressure. A comparison between castings obtained by both centrifugal casting technique and gravity casting technique is made for reference (gravity casting)

  14. The American Gas Centrifuge Past, Present, and Future

    SciTech Connect

    Waters, Dean

    2004-09-15

    The art of gas centrifugation was born in 1935 at the University of Virginia when Dr. Jesse Beams demonstrated experimentally the separation of chlorine isotopes using an ultra-high speed centrifuge. Dr. Beam’s experiment initiated work that created a rich history of scientific and engineering accomplishment in the United States in the art of isotope separation and even large scale biological separation by centrifugation. The early history of the gas centrifuge development was captured in a lecture and documented by Dr. Jesse Beams in 1975. Much of Dr. Beams lecture material is used in this paper up to the year 1960. Following work by Dr. Gernot Zippe at the University of Virginia between 1958 and 1960, the US government embarked on a centrifuge development program that ultimately led to the start of construction of the Gas Centrifuge Enrichment Plant in Piketon Ohio in the late 1970’s. The government program was abandoned in 1985 after investing in the construction of two of six planned process buildings, a complete supply chain for process and centrifuge parts, and the successful manufacture and brief operation of an initial complement of production machines that would have met 15 percent of the planned capacity of the constructed process buildings. A declining market for enriched uranium, a glut of uranium enrichment capacity worldwide, and the promise of a new laser based separation process factored in the decision to stop the government program. By the late 1990’s it had become evident that gas centrifugation held the best promise to produce enriched uranium at low cost. In1999, the United States Enrichment Corporation undertook an initiative to revive the best of the American centrifuge technology that had been abandoned fourteen years earlier. This is an exciting story and one that when complete will enable the United States to maintain its domestic supply and to be highly competitive in the world market for this important energy commodity. (auth)

  15. 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 ...

  16. Ocular counterrolling induced by centrifugation during orbital space flight

    NASA Technical Reports Server (NTRS)

    Moore, S. T.; Clement, G.; Raphan, T.; Cohen, B.

    2001-01-01

    During the 1998 Neurolab mission (STS-90), four astronauts were exposed to interaural centripetal accelerations (Gy centrifugation) of 0.5 g and 1 g during rotation on a centrifuge, both on Earth and during orbital space flight. Subjects were oriented either left-ear out or right-ear out, facing or back to motion. Binocular eye movements were measured in three dimensions using a video technique. On Earth, tangential centrifugation that produces 1 g of interaural linear acceleration combines with gravity to tilt the gravitoinertial acceleration (GIA) vector 45 degrees in the roll plane relative to the head vertical, generating a summed vector of 1.4 g. Before flight, this elicited mean ocular counterrolling (OCR) of 5.7 degrees. Due to the relative absence of gravity during flight, there was no linear acceleration along the dorsoventral axis of the head. As a result, during in-flight centrifugation, gravitoinertial acceleration was strictly aligned with the centripetal acceleration along the interaural axis. There was a small but significant decrease (mean 10%) in the magnitude of OCR in space (5.1 degrees). The magnitude of OCR during postflight 1 g centrifugation was not significantly different from preflight OCR (5.9 degrees). Findings were similar for 0.5 g centrifugation, but the OCR magnitude was approximately 60% of that induced by centrifugation at 1 g. OCR during pre- and postflight static tilt was not significantly different and was always less than OCR elicited by centrifugation of Earth for an equivalent interaural linear acceleration. In contrast, there was no difference between the OCR generated by in-flight centrifugation and by static tilt on Earth at equivalent interaural linear accelerations. These data support the following conclusions: (1) OCR is generated predominantly in response to interaural linear acceleration; (2) the increased OCR during centrifugation on Earth is a response to the head dorsoventral 1 g linear acceleration component, which

  17. Centrifugal pumps: which suction specific speeds are acceptable

    SciTech Connect

    Hallam, J.L.

    1982-04-01

    Suction specific speed is an important consideration when purchasing or analyzing centrifugal pumps. There is a direct correlation between this parameter, pump reliability and maintenance expenses. This article demonstrates that in a large Gulf Coast oil refinery, centrifugal pumps with a suction specific speed greater than 11,000 failed at a frequency nearly twice that of centrifugal pumps with suction specific speed less than 11,000. This study consisted primarily of hydrocarbon pumps with an average horsepower of 150 hp. Results may vary some from those found if high energy water pumps are studied. 5 refs.

  18. Centrifugal Size-Separation Sieve for Granular Materials

    NASA Technical Reports Server (NTRS)

    Walton, Otis (Inventor); Dreyer, Christopher (Inventor); Riedel, Edward (Inventor)

    2015-01-01

    A centrifugal sieve and method utilizes centrifugal force in rapidly-rotated cylindrical or conical screens as the primary body force contributing to size segregation. Within the centrifugal acceleration field, vibration and/or shearing flows are induced to facilitate size segregation and eventual separation of the fines from the coarse material. Inside a rotating cylindrical or conical screen, a separately-rotated screw auger blade can be used to transport material along the rotating cylinder or conical wall and to induce shearing in the material.

  19. 27. RW Meyer Sugar Mill: 18761889. Centrifugals, 1879, 1881. Manufacturer, ...

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

    27. RW Meyer Sugar Mill: 1876-1889. Centrifugals, 1879, 1881. Manufacturer, Unknown. Supplied by Honolulu Ironworks, Honolulu Hawaii, 1879, 1881. View: Historical view, 1934, from T.T. Waterman collection, Hawaiian Sugar Planters' Association. With the inner basket of the centrifugal revolving at 1200 rpm molasses flew outward from the granulated sugar, through the holes in the brass lining, and into the stationary outer basket. The molasses drained through the spout at the right and into molasses storage pits below the floor. The centrifugals were underdriven with a belt connected to the pulley beneath the basket. - R. W. Meyer Sugar Mill, State Route 47, Kualapuu, Maui County, HI

  20. Increased mitogenic response in lymphocytes from chronically centrifuged mice

    NASA Technical Reports Server (NTRS)

    Mueller, Otfried; Hunzinger, E.; Cogoli, Augusto; Bechler, B.; Lee, J.; Moore, J.; Duke, J.

    1990-01-01

    The effects upon the mitogenic response of splenic lymphocytes when exposing mice to prolonged hypergravity conditions (3.5 G for 1 year) were studied. Cultures of splenic lymphocytes isolated from both centrifuged and control (1 G) animals were stimulated with Concanavalin A and the response measured using both morphological and biochemical means. Lymphocytes obtained from centrifuged mice exhibited much higher activation rates (as measured by the incorporation of H-3 thymidine) and larger cell aggregates consisting of more lymphoblasts and mitotic figures than those observed in non centrifuged control animals. Isolated splenic lymphocytes thus appear to have been conditioned by hypergravity state.

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

    PubMed

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

    2006-05-01

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

  2. Granular media filtration: old process, new thoughts.

    PubMed

    Lawler, D F; Nason, J A

    2006-01-01

    The design of granular media filters has evolved over many years so that modern filters have larger media sizes and higher filtration velocities than in earlier times. The fundamental understanding of filtration has also improved over time, with current models that account reasonably for all characteristics of the media, the suspension and the filter operation. The methodology for design, however, has not kept pace with these improvements; current designs are based on pilot plants, past experience, or a simple guideline (the ratio of the bed depth to media grain size). We propose that design should be based universally on a characteristic removal length, with the provision of a bed depth that is some multiple of that characteristic length. This characteristic removal length is calculated using the most recent (and most complete) fundamental model and is based on the particle size with the minimum removal efficiency in a filter. The multiple of the characteristic length that yields the required bed depth has been calibrated to existing, successful filters.

  3. Approximate theory for radial filtration/consolidation

    SciTech Connect

    Tiller, F.M.; Kirby, J.M.; Nguyen, H.L.

    1996-10-01

    Approximate solutions are developed for filtration and subsequent consolidation of compactible cakes on a cylindrical filter element. Darcy`s flow equation is coupled with equations for equilibrium stress under the conditions of plane strain and axial symmetry for radial flow inwards. The solutions are based on power function forms involving the relationships of the solidosity {epsilon}{sub s} (volume fraction of solids) and the permeability K to the solids effective stress p{sub s}. The solutions allow determination of the various parameters in the power functions and the ratio k{sub 0} of the lateral to radial effective stress (earth stress ratio). Measurements were made of liquid and effective pressures, flow rates, and cake thickness versus time. Experimental data are presented for a series of tests in a radial filtration cell with a central filter element. Slurries prepared from two materials (Microwate, which is mainly SrSO{sub 4}, and kaolin) were used in the experiments. Transient deposition of filter cakes was followed by static (i.e., no flow) conditions in the cake. The no-flow condition was accomplished by introducing bentonite which produced a nearly impermeable layer with negligible flow. Measurement of the pressure at the cake surface and the transmitted pressure on the central element permitted calculation of k{sub 0}.

  4. Particle Dynamics in Tangential Flow Filtration

    NASA Astrophysics Data System (ADS)

    Garcia, Mike; Pennathur, Sumita

    2015-11-01

    Tangential Flow Filtration (TFF) is a rapid and efficient method for filtration and separation of solutions containing particles such as viruses, bacteria or cellular material. Enhancing the efficiency of TFF not only requires a detailed understanding of the individual mechanisms behind particle transport, but the interaction between these transport mechanisms and a porous wall. In this work, we numerically and experimentally explore how inertial migration is affected by the presence of a permeate flow through the porous walls of a microchannel in order to develop a platform for further studies of particle transport in a TFF device. Numerically, we use COMSOL multiphysics to model the large parameter space of permeate versus inertial forces. Experimentally, we develop a MEMS fabricated TFF device to confirm the results of the numerical model, where the permeate flow is controlled using multiple pumps and pressure transducers regulated by a feedback loop. Experimental and numerical results reveal interesting dynamics, including the competition between permeate and inertial forces and the consequences of this competition on particle trajectories and equilibrium location.

  5. METC CFD simulations of hot gas filtration

    SciTech Connect

    O`Brien, T.J.

    1995-06-01

    Computational Fluid Dynamic (CFD) simulations of the fluid/particle flow in several hot gas filtration vessels will be presented. These simulations have been useful in designing filtration vessels and in diagnosing problems with filter operation. The simulations were performed using the commercial code FLUENT and the METC-developed code MFIX. Simulations of the initial configuration of the Karhula facility indicated that the dirty gas flow over the filter assemblage was very non-uniform. The force of the dirty gas inlet flow was inducing a large circulation pattern that caused flow around the candles to be in opposite directions on opposite sides of the vessel. By introducing a system of baffles, a more uniform flow pattern was developed. This modification may have contributed to the success of the project. Several simulations of configurations proposed by Industrial Filter and Pump were performed, varying the position of the inlet. A detailed resolution of the geometry of the candles allowed determination of the flow between the individual candles. Recent simulations in support of the METC/CeraMem Cooperative Research and Development Agreement have analyzed the flow in the vessel during the cleaning back-pulse. Visualization of experiments at the CeraMem cold-flow facility provided confidence in the use of CFD. Extensive simulations were then performed to assist in the design of the hot test facility being built by Ahlstrom/Pyropower. These tests are intended to demonstrate the CeraMem technology.

  6. Dewatering of flocculated suspensions by pressure filtration

    NASA Astrophysics Data System (ADS)

    Landman, K. A.; Sirakoff, C.; White, L. R.

    1991-06-01

    Pressure filtration is an important method for removing liquids from a suspension. Previous work used linear models or applied to stable suspensions. Nonlinear models for flocculated suspensions are studied here. The equations governing the consolidation of flocculated suspensions under the influence of an applied pressure are based on the assumption that when the volume fraction is high enough, the network formed from the aggregation of flocs possesses a compressive yield stress Py(φ) that is a function of local volume fraction φ only. There are two modes of operation of the pressure filter—the fluid flux or the applied pressure is specified—and both of these are studied. The resulting nonlinear partial differential equations involve the time-dependent piston position, and in the case of the suspension being initially unnetworked, another internal moving boundary below which the suspension is networked. The small time behavior of these systems is obtained with an asymptotic method. In general, at later times, the solution can only be found numerically and an algorithm for doing this is discussed. The important parameters and properties of the filter cake are described. The results suggest various ways of controlling the filtration process, which may be useful in the manufacture of ceramics.

  7. Addi-Chek filtration, BACTEC, and 10-ml culture methods for recovery of microorganisms from dialysis effluent during episodes of peritonitis.

    PubMed

    Males, B M; Walshe, J J; Garringer, L; Koscinski, D; Amsterdam, D

    1986-02-01

    The Addi-Chek (filtration; Millipore Corp., Bedford, Mass.) and BACTEC (radiometric detection of growth in culture media; Johnston Laboratories, Inc., Towson, Md.) systems were compared with the 10-ml culture (centrifugation) method for the recovery of microorganisms from peritoneal dialysate collected from patients with clinical evidence of peritonitis and containing greater than or equal to 200 leukocytes per mm3. Both alternate methods were comparable, and results were not significantly different from those of the conventional 10-ml culture method. All systems were adversely affected in their capacity to recover organisms when dialysates had been collected during periods of antimicrobial therapy.

  8. Removal of Cryptosporidium parvum in bank filtration systems

    NASA Astrophysics Data System (ADS)

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

    2003-04-01

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

  9. Simulation of combined rapid gravity filtration and backwash models.

    PubMed

    Han, S J; Fitzpatrick, C S B; Wetherill, A

    2009-01-01

    Combined rapid gravity filtration and backwash models are applied to simulate filtration and backwash cycles. The simulated results from the backwash model suggest that air flow rate can be optimised to maximise particle removal efficiency in the backwash for a particular system. The simulation of combined rapid gravity filtration and backwash models suggests that efficient backwash operation is essential for maintaining the life time of a filter. However, the filter is not advised to be completely cleaned up in the backwash and the particles retained on filter grains after the backwash can be beneficial for subsequent filtration runs.

  10. Simulation on combined rapid gravity filtration and backwash models.

    PubMed

    Han, S J; Fitzpatrick, C S B; Wetherill, A

    2009-01-01

    Combined rapid gravity filtration and backwash models have been applied to simulate filtration and backwash cycles. The simulated results from the backwash model suggest that an optimum air flow rate exists to maximise particle removal efficiency in the backwash operation for a certain backwash system. The simulation of combined rapid gravity filtration and backwash models suggests that the filter should not be completely cleaned up in the backwash and a certain amount of particles retained on filter grains after backwash can be beneficial for subsequent filtration runs. This is consistent with the experimental results in the literature.

  11. Rapid concentration of Bacillus and Clostridium spores from large volumes of milk, using continuous flow centrifugation.

    PubMed

    Agoston, Réka; Soni, Kamlesh A; McElhany, Katherine; Cepeda, Martha L; Zuckerman, Udi; Tzipori, Saul; Mohácsi-Farkas, Csilla; Pillai, Suresh D

    2009-03-01

    Deliberate or accidental contamination of foods such as milk, soft drinks, and drinking water with infectious agents or toxins is a major concern to health authorities. There is a critical need to develop technologies that can rapidly and efficiently separate and concentrate biothreat agents from food matrices. A key limitation of current centrifugation and filtration technologies is that they are batch processes with extensive hands-on involvement and processing times. The objective of our studies was to evaluate the continuous flow centrifugation (CFC) technique for the rapid separation and concentration of bacterial spores from large volumes of milk. We determined the effectiveness of the CFC technology for concentrating approximately 10(3) bacterial spores in 3.7 liters (1 gal) of whole milk and skim milk, using Bacillus subtilis, Bacillus atrophaeus, and Clostridium sporogenes spores as surrogates for biothreat agents. The spores in the concentrated samples were enumerated by using standard plating techniques. Three independent experiments were performed at 10,000 rpm and 0.7 liters/min flow rate. The mean B. subtilis spore recoveries were 71.3 and 56.5% in skim and whole milk, respectively, and those for B. atrophaeus were 55 and 59.3% in skim and whole milk, respectively. In contrast, mean C. sporogenes spore recoveries were 88.2 and 78.6% in skim and whole milk, respectively. The successful use of CFC to concentrate these bacterial spores from 3.7 liters of milk in 10 min shows promise for rapidly concentrating other spores from large volumes of milk.

  12. Investigation of Flow in a Centrifugal Pump

    NASA Technical Reports Server (NTRS)

    Fischer, Karl

    1946-01-01

    The investigation of the flow in a centrifugal pump indicated that the flow patterns in frictional fluid are fundamentally different from those in frictionless fluid. In particular, the dead air space adhering to the section side undoubtedly causes a reduction of the theoretically possible delivery head. The velocity distribution over a parallel circle is also subjected to a noticeable change as a result of the incomplete filling of the passages. The relative velocity on the pressure side of the vane, which for passages completely filled with active flow would differ little from zero even at comparatively lower than normal delivery volume, is increased, so that no rapid reverse flow occurs on the pressure side of the vane even for smaller delivery volume. It was established, further, that the flow ceases to be stationary for very small quantities of water. The inflow to the impeller can be regarded as radial for the operating range an question. The velocity triangles at the exit are subjected to a significant alteration in shape ae a result of the increased peripheral velocity, which may be of particular importance in the determination of the guide vane entrance angle.

  13. Centrifugal governor for internal combustion engines

    SciTech Connect

    Ohnishi, M.

    1986-08-12

    A centrifugal governor is described for use with an internal combustion engine, comprising: a control rack for regulating the quantity of fuel to be supplied to the engine; flyweights radially displaceable in response to the rotational speed of the engine; a tension lever pivotable about a stationary fulcrum in response to the radial displacement of the flyweights; a torque cam having a cam surface determining a fuel increment to be applied at the start of the engine; a sensor lever having one end engaged by the control rack and another end disposed for engagement with the cam surface of the torque cam, the sensor lever being adapted to engage with the cam surface of the torque cam when the engine is in a starting condition, to cause displacement of the control rack into a fuel increasing position for the start of the engine; and spring means interposed between the torque cam and the tension lever and urging the torque cam with a force dependent upon the angularity of the tension lever in a direction of disengaging the sensor lever from the cam surface of the torque cam; the spring means comprising first and second springs, one of the first and second springs being formed of a thermosensitive material having a smaller spring constant at a low temperature below a predetermined value, and a larger spring constant at a temperature above the predetermined value; and the first and second springs of the spring means comprising coiled springs disposed concentrically with each other.

  14. Centrifugal governor for internal combustion engines

    SciTech Connect

    Ohkoshi, M.

    1987-04-14

    This patent describes a centrifugal governor for use with an internal combustion engine, comprising: a control rack for regulating the quantity of fuel to be supplied to the engine; flyweights radially displaceable in response to the rotational speed of the engine; a tension lever pivotable through an angle dependent upon the amount of radial displacement of the flyweights; a torque cam pivotable about and relative to a fulcrum shaft thereof and having a cam surface including a cam surface portion determining a fuel increment to be applied at the start of the engine; a sensor lever having one end engaged by the control rack; the sensor lever having another end disposed to engage with the cam surface portion of the torque cam when the engine is in a starting condition, to permit displacement of the control rack into a fuel increasing position for the start of the engine; and a cancelling spring interposed between the torque cam and the tension lever and urging the torque cam with a force dependent upon the angularity of the tension lever to cause pivoting of the torque cam about the fulcrum shaft thereof in a direction of disengaging the sensor lever from the cam surface portion of the torque cam. The improvement is described comprising biasing means for forcibly pivotally displacing, immediately before operation of a starter of the engine, the torque cam in one direction against the urging force of the cancelling spring to a predetermined position.

  15. Fluid dynamic noise in a centrifugal pump

    NASA Astrophysics Data System (ADS)

    Tse, D. G.; Whitelaw, J. H.

    1993-08-01

    Pressure distributions and frequency spectra have been obtained in a centrifugal pump having flow rates between the design point and near shut-down. The pump was comprised of a radial flow impeller with four backswept blades and a single volute. Measurements were obtained at the design flow rate and at off-design conditions to advance understanding of noise generation, to quantify the contribution of tonal, narrowband and broadband components to the overall noise and to develop strategies for suppressing fluid dynamic noise by flow control and active control. Fluid dynamic noise was generated by the unsteady conditions encountered by the impeller blade. Unsteady conditions originated from non-uniformities at the inlet and the impeller outlet at design and off-design conditions. Inlet flow non-uniformity was induced by separation regions. Flow separations are inherent in turbomachinery because of growth of the boundary layer and the disturbance effect of the rotating impeller. Flow non-uniformity at the impeller outlet stemmed from inlet flow non-uniformities in the inlet, from propagation of pressure waves in a vaneless diffuser, and from scroll effects.

  16. Wave Augmented Diffuser for Centrifugal Compressor

    NASA Technical Reports Server (NTRS)

    Skoch, Gary J. (Inventor); Paxson, Daniel E. (Inventor)

    2001-01-01

    A wave augmented diffuser for a centrifugal compressor surrounds the outlet of an impeller that rotates on a drive shaft having an axis of rotation. The impeller brings flow in in an axial direction and imparts kinetic energy to the flow discharging it in radial and tangential directions. The flow is discharged into a plurality of circumferentially disposed wave chambers. The wave chambers are periodically opened and closed by a rotary valve such that the flow through the diffuser is unsteady. The valve includes a plurality of valve openings that are periodically brought into and out of fluid communication with the wave chambers. When the wave chambers are closed, a reflected compression wave moves upstream towards the diffuser bringing the flow into the wave chamber to rest. This action recovers the kinetic energy from the flow and limits any boundary layer growth. The flow is then discharged in an axial direction through an opening in the valve plate when the valve plate is rotated to an open position. The diffuser thus efficiently raises the static pressure of the fluid and discharges an axially directed flow at a radius that is predominantly below the maximum radius of the diffuser.

  17. High efficiency, variable geometry, centrifugal cryogenic pump

    SciTech Connect

    Forsha, M.D.; Nichols, K.E.; Beale, C.A.

    1994-12-31

    A centrifugal cryogenic pump has been developed which has a basic design that is rugged and reliable with variable speed and variable geometry features that achieve high pump efficiency over a wide range of head-flow conditions. The pump uses a sealless design and rolling element bearings to achieve high reliability and the ruggedness to withstand liquid-vapor slugging. The pump can meet a wide range of variable head, off-design flow requirements and maintain design point efficiency by adjusting the pump speed. The pump also has features that allow the impeller and diffuser blade heights to be adjusted. The adjustable height blades were intended to enhance the pump efficiency when it is operating at constant head, off-design flow rates. For small pumps, the adjustable height blades are not recommended. For larger pumps, they could provide off-design efficiency improvements. This pump was developed for supercritical helium service, but the design is well suited to any cryogenic application where high efficiency is required over a wide range of head-flow conditions.

  18. Central centrifugal cicatricial alopecia: challenges and solutions

    PubMed Central

    Herskovitz, Ingrid; Miteva, Mariya

    2016-01-01

    Central centrifugal cicatricial alopecia (CCCA) is the most common scarring alopecia among African American women. Data about epidemiology, etiology, genetic inheritance, and management are scarce and come from individual reports or small series. CCCA has been associated with hot combing and traumatic hair styling for years; however, studies fail to confirm it as the sole etiologic factor. It has been shown in a small series that CCCA can be inherited in an autosomal dominant fashion, with a partial penetrance and a strong modifying effect of hairstyling and sex. CCCA presents clinically as a central area of progressive irreversible hair loss that expands to the periphery. A patchy form has also been described. Dermoscopy is helpful to identify the optimal site for the biopsy, which establishes the diagnosis. Well-designed randomized controlled trials are needed to discover the optimal management. At this point, patients are advised to avoid traction and chemical treatments; topical and intralesional steroids, calcineurin inhibitors, and minoxidil can be helpful in halting the progression. PMID:27574457

  19. 18. View north of Tropic Chamber Worthington centrifugal compressor and ...

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

    18. View north of Tropic Chamber Worthington centrifugal compressor and control panel, in machine area. - Natick Research & Development Laboratories, Climatic Chambers Building, U.S. Army Natick Research, Development & Engineering Center (NRDEC), Natick, Middlesex County, MA

  20. 16. View northwest of Arctic Chamber Worthington centrifugal compressor and ...

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

    16. View northwest of Arctic Chamber Worthington centrifugal compressor and control panel, in machine area. - Natick Research & Development Laboratories, Climatic Chambers Building, U.S. Army Natick Research, Development & Engineering Center (NRDEC), Natick, Middlesex County, MA

  1. A multiplexed immunoassay system based upon reciprocating centrifugal microfluidics

    NASA Astrophysics Data System (ADS)

    Noroozi, Zahra; Kido, Horacio; Peytavi, Régis; Nakajima-Sasaki, Rie; Jasinskas, Algimantas; Micic, Miodrag; Felgner, Philip L.; Madou, Marc J.

    2011-06-01

    A novel, centrifugal disk-based micro-total analysis system (μTAS) for low cost and high throughput semi-automated immunoassay processing was developed. A key innovation in the disposable immunoassay disk design is in a fluidic structure that enables very efficient micro-mixing based on a reciprocating mechanism in which centrifugal acceleration acting upon a liquid element first generates and stores pneumatic energy that is then released by a reduction of the centrifugal acceleration, resulting in a reversal of direction of flow of the liquid. Through an alternating sequence of high and low centrifugal acceleration, the system reciprocates the flow of liquid within the disk to maximize incubation/hybridization efficiency between antibodies and antigen macromolecules during the incubation/hybridization stage of the assay. The described reciprocating mechanism results in a reduction in processing time and reagent consumption by one order of magnitude.

  2. 3. Interior view of centrifugal pump house showing pumps and ...

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

    3. Interior view of centrifugal pump house showing pumps and engines, looking W. - Laurel Valley Sugar Plantation, Drainage Plant, 2 Miles South of Thibodaux on State Route 308, Thibodaux, Lafourche Parish, LA

  3. 2. View of centrifugal pump house sitting at edge of ...

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

    2. View of centrifugal pump house sitting at edge of drainage canal, looking E. - Laurel Valley Sugar Plantation, Drainage Plant, 2 Miles South of Thibodaux on State Route 308, Thibodaux, Lafourche Parish, LA

  4. 23. TEMPORARY CENTRIFUGAL PUMP. NOTE CHAPMAN HYDRAULICOPERATED VALVE FOR LATER ...

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

    23. TEMPORARY CENTRIFUGAL PUMP. NOTE CHAPMAN HYDRAULIC-OPERATED VALVE FOR LATER CONNECTION OF ENGINE PUMP ENG TO DISCHARGE HEADER. - Lakeview Pumping Station, Clarendon & Montrose Avenues, Chicago, Cook County, IL

  5. Manufacture of hollow ingots using centrifugal casting machines

    NASA Astrophysics Data System (ADS)

    Pomeshchikov, A. G.; Greneva, T. S.; Baidachenko, V. I.; Berezin, V. I.

    2010-12-01

    Centrifugal machines are proposed for the foundry created at the Almalyk Mining and Smelting Factory in order to produce hollow ingots of a liquid metal made by remelting of consumable electrodes in a refractory accumulating crucible.

  6. 25. RW Meyer Sugar Mill: 18761889. Centrifugals, 1879, 1881. Manufacturer, ...

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

    25. RW Meyer Sugar Mill: 1876-1889. Centrifugals, 1879, 1881. Manufacturer, Unknown. Supplied by Honolulu Iron Works, Honolulu, Hawaii, 1879, 1881. View: After sugar was granulated and cooled it had to be dried and drained, completely separating the sugar crystals from the molasses. Revolving at 1200 rpm the inner basket drove the molasses outward into the stationary outer basket leaving dried sugar behind. The steam engine counter-shaft at the left was belt driven and belts running from the counter-shaft pulleys to the centrifugals' base-pulleys provided the necessary power. Part of the clutch system which moved the belt from a moving to a stationary pulley, thus turning the centrifugals on and off, is seen in Between the counter-shaft and the centrifugals. - R. W. Meyer Sugar Mill, State Route 47, Kualapuu, Maui County, HI

  7. 19. LOWER OIL ROOM DIABLO POWERHOUSE: SHARPLES OIL CENTRIFUGE AND ...

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

    19. LOWER OIL ROOM DIABLO POWERHOUSE: SHARPLES OIL CENTRIFUGE AND OIL TANK, 1989. - Skagit Power Development, Diablo Powerhouse, On Skagit River, 6.1 miles upstream from Newhalem, Newhalem, Whatcom County, WA

  8. Looking Southeast at Precipitation System, Steam Dryer and Centrifuge in ...

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

    Looking Southeast at Precipitation System, Steam Dryer and Centrifuge in Red Room within Recycle Recovery Building - Hematite Fuel Fabrication Facility, Recycle Recovery Building, 3300 State Road P, Festus, Jefferson County, MO

  9. A multiplexed immunoassay system based upon reciprocating centrifugal microfluidics

    PubMed Central

    Noroozi, Zahra; Kido, Horacio; Peytavi, Régis; Nakajima-Sasaki, Rie; Jasinskas, Algimantas; Micic, Miodrag; Felgner, Philip L.; Madou, Marc J.

    2011-01-01

    A novel, centrifugal disk-based micro-total analysis system (μTAS) for low cost and high throughput semi-automated immunoassay processing was developed. A key innovation in the disposable immunoassay disk design is in a fluidic structure that enables very efficient micro-mixing based on a reciprocating mechanism in which centrifugal acceleration acting upon a liquid element first generates and stores pneumatic energy that is then released by a reduction of the centrifugal acceleration, resulting in a reversal of direction of flow of the liquid. Through an alternating sequence of high and low centrifugal acceleration, the system reciprocates the flow of liquid within the disk to maximize incubation/hybridization efficiency between antibodies and antigen macromolecules during the incubation/hybridization stage of the assay. The described reciprocating mechanism results in a reduction in processing time and reagent consumption by one order of magnitude. PMID:21721711

  10. TECHNOLOGY EVALUATION REPORT: RETECH'S PLASMA CENTRIFUGAL FURNACE - VOLUME I

    EPA Science Inventory

    A demonstration of the Retech, Inc. Plasma Centrifugal Furnace (PCF) was conducted under the Superfund Innovative Technology Evaluation (SITE) Program at the Department of Energy's (DOE's) Component Development and Integration Facility in Butte, Montana. The furnace uses heat gen...

  11. 14. CENTRIFUGAL FREQUENCY RELAY IN WAYSIDE CABINET, NEW HAVEN YARD ...

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

    14. CENTRIFUGAL FREQUENCY RELAY IN WAYSIDE CABINET, NEW HAVEN YARD - New York, New Haven & Hartford Railroad, Automatic Signalization System, Long Island Sound shoreline between Stamford & New Haven, Stamford, Fairfield County, CT

  12. 15. FRONT VIEW, DETAIL, CENTRIFUGAL FREQUENCY RELAY IN WAYSIDE CABINET, ...

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

    15. FRONT VIEW, DETAIL, CENTRIFUGAL FREQUENCY RELAY IN WAYSIDE CABINET, NEW HAVEN YARD - New York, New Haven & Hartford Railroad, Automatic Signalization System, Long Island Sound shoreline between Stamford & New Haven, Stamford, Fairfield County, CT

  13. 8. FLOOR 1: TENTERING GEAR FOR SOUTH STONES, CENTRIFUGAL GOVERNOR ...

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

    8. FLOOR 1: TENTERING GEAR FOR SOUTH STONES, CENTRIFUGAL GOVERNOR MOUNTED ON STONE SPINDLE, VERY SHORT STEELYARD - Windmill at Water Mill, Montauk Highway & Halsey Lane, Water Mill, Suffolk County, NY

  14. Centrifuge Facility for the International Space Station Alpha

    NASA Technical Reports Server (NTRS)

    Johnson, Catherine C.; Hargens, Alan R.

    1994-01-01

    The Centrifuge Facility planned for the International Space Station Alpha has under-one considerable redesign over the past year, primarily because the Station is now viewed as a 10 year mission rather than a 30 year mission and because of the need to simply the design to meet budget constraints and a 2000 launch date. The basic elements of the Centrifuge Facility remain the same, i.e., a 2.5 m diameter centrifuge, a micro-g holding unit, plant and animal habitats, a glovebox and a service unit. The centrifuge will still provide the full range of artificial gravity from 0.01 a to 2 - as originally planned; however, the extractor to permit withdrawal of habitats from the centrifuge without stopping the centrifuge has been eliminated. The specimen habitats have also been simplified and are derived from other NASA programs. The Plant Research Unit being developed by the Gravitational Biology Facility will be used to house plants in the Centrifuge Facility. Although not as ambitious as the Centrifuge Facility plant habitat, it will provide much better environmental control and lighting than the current Shuttle based Plant Growth Facility. Similarly, rodents will be housed in the Advanced Animal Habitat being developed for the Shuttle program. The Centrifuge Facility and ISSA will provide the opportunity to perform repeatable, high quality science. The long duration increments available on the Station will permit multigeneration studies on both plants and animals which have not previously been possible. The Centrifuge Facility will accommodate sufficient number of specimens to permit statistically significant sampling of specimens to investigate the time course of adaptation to altered gravity environments. The centrifuge will for the first time permit investigators to use gravity itself as a tool to investigate fundamental processes, to investigate the intensity and duration of gravity to maintain normal structure and function, to separate the effects of micro-g from

  15. Centrifugal microfluidic platforms: advanced unit operations and applications.

    PubMed

    Strohmeier, O; Keller, M; Schwemmer, F; Zehnle, S; Mark, D; von Stetten, F; Zengerle, R; Paust, N

    2015-10-07

    Centrifugal microfluidics has evolved into a mature technology. Several major diagnostic companies either have products on the market or are currently evaluating centrifugal microfluidics for product development. The fields of application are widespread and include clinical chemistry, immunodiagnostics and protein analysis, cell handling, molecular diagnostics, as well as food, water, and soil analysis. Nevertheless, new fluidic functions and applications that expand the possibilities of centrifugal microfluidics are being introduced at a high pace. In this review, we first present an up-to-date comprehensive overview of centrifugal microfluidic unit operations. Then, we introduce the term "process chain" to review how these unit operations can be combined for the automation of laboratory workflows. Such aggregation of basic functionalities enables efficient fluidic design at a higher level of integration. Furthermore, we analyze how novel, ground-breaking unit operations may foster the integration of more complex applications. Among these are the storage of pneumatic energy to realize complex switching sequences or to pump liquids radially inward, as well as the complete pre-storage and release of reagents. In this context, centrifugal microfluidics provides major advantages over other microfluidic actuation principles: the pulse-free inertial liquid propulsion provided by centrifugal microfluidics allows for closed fluidic systems that are free of any interfaces to external pumps. Processed volumes are easily scalable from nanoliters to milliliters. Volume forces can be adjusted by rotation and thus, even for very small volumes, surface forces may easily be overcome in the centrifugal gravity field which enables the efficient separation of nanoliter volumes from channels, chambers or sensor matrixes as well as the removal of any disturbing bubbles. In summary, centrifugal microfluidics takes advantage of a comprehensive set of fluidic unit operations such as

  16. Preferred orientation of BSCCO via centrifugal slip casting

    SciTech Connect

    Steinlage, G.; Roeder, R.; Trumble, K.; Bowman, K. ); Li, S.; McElfresh, M. )

    1994-04-01

    Due to the highly anisotropic properties of BSCCO superconductors, the bulk properties of these materials can be greatly affected by preferential orientation. Substantial [ital c]-axis orientation normal to the desired direction of current flow has been demonstrated by centrifugally slip casting lead-doped BSCCO-2223. The strong preferred orientation developed in the centrifugally slip-cast material demonstrates high critical current potential.

  17. Synchronization of Mammalian Cells and Nuclei by Centrifugal Elutriation.

    PubMed

    Banfalvi, Gaspar

    2017-01-01

    Synchronized populations of large numbers of cells can be obtained by centrifugal elutriation on the basis of sedimentation properties of small round particles, with minimal perturbation of cellular functions. The physical characteristics of cell size and sedimentation velocity are operative in the technique of centrifugal elutriation also known as counterstreaming centrifugation. The elutriator is an advanced device for increasing the sedimentation rate to yield enhanced resolution of cell separation. A random population of cells is introduced into the elutriation chamber of an elutriator rotor running in a specially designed centrifuge. By increasing step-by-step the flow rate of the elutriation fluid, successive populations of relatively homogeneous cell size can be removed from the elutriation chamber and used as synchronized subpopulations. For cell synchronization by centrifugal elutriation, early log S phase cell populations are most suitable where most of the cells are in G1 and S phase (>80 %). Apoptotic cells can be found in the early elutriation fractions belonging to the sub-Go window. Protocols for the synchronization of nuclei of murine pre-B cells and high-resolution centrifugal elutriation of CHO cells are given. The verification of purity and cell cycle positions of cells in elutriated fractions includes the measurement of DNA synthesis by [(3)H]-thymidine incorporation and DNA content by propidium iodide flow cytometry.

  18. Improved g-level calculations for coil planet centrifuges.

    PubMed

    van den Heuvel, Remco N A M; König, Carola S

    2011-09-09

    Calculation of the g-level is often used to compare CCC centrifuges, either against each other or to allow for comparison with other centrifugal techniques. This study shows the limitations of calculating the g-level in the traditional way. Traditional g-level calculations produce a constant value which does not accurately reflect the dynamics of the coil planet centrifuge. This work has led to a new equation which can be used to determine the improved non-dimensional values. The new equations describe the fluctuating radial and tangential g-level associated with CCC centrifuges and the mean radial g-level value. The latter has been found to be significantly different than that determined by the traditional equation. This new equation will give a better understanding of forces experienced by sample components and allows for more accurate comparison between centrifuges. Although the new equation is far better than the traditional equation for comparing different types of centrifuges, other factors such as the mixing regime may need to be considered to improve the comparison further.

  19. Optimizing the separation performance of a gas centrifuge

    NASA Astrophysics Data System (ADS)

    Wood, H. G.

    1997-11-01

    Gas centrifuges were originally developed for the enrichment of U^235 from naturally occurring uranium for the purpose of providing fuel for nuclear power reactors and material for nuclear weapons. This required the separation of a binary mixture composed of U^235 and U^238. Since the end of the cold war, a surplus of enriched uranium exists on the world market, but many centrifuge plants exist in numerous countries. These circumstances together with the growing demand for stable isotopes for chemical and physical research and in medical science has led to the exploration of alternate applications of gas centrifuge technology. In order to acieve these multi-component separations, existing centrifuges must be modified or new centrifuges must be designed. In either case, it is important to have models of the internal flow fields to predict the separation performance and algorithms to seek the optimal operating conditions of the centrifuges. Here, we use the Onsager pancake model of the internal flow field, and we present an optimization strategy which exploits a similarity parameter in the pancake model. Numerical examples will be presented.

  20. The slide centrifuge gram stain as a urine screening method.

    PubMed

    Olson, M L; Shanholtzer, C J; Willard, K E; Peterson, L R

    1991-10-01

    A slide centrifuge Gram stain procedure was performed to screen for bacteriuria 4161 urine specimens submitted in urine preservative tubes for routine culture. For slide centrifuge Gram staining, each urine sample was mixed well. Thereafter, 0.2 mL of each sample was placed, using a pipette, into a slide centrifuge chamber and centrifuged at 2,000 rpm for 5 minutes. The slides were heat fixed, Gram stained, and read by laboratory personnel who scanned 12 consecutive oil-immersion fields using a set pattern. The presence of the same organism in six or more fields was defined as a positive urine screen. Urine samples were cultured using a 0.001-mL loop and a comparison of culture growth with slide centrifuge screening was made. When growth of 100,000 or more colony-forming units per milliliter (CFU/mL) was the reference for comparison, the screen had a sensitivity rate of 98%, a specificity rate of 90%, a negative predictive value of 99%, and a positive predictive value of 65%. When a lower colony count of 10,000 or more CFU/mL was the reference for comparison, the screen had a sensitivity rate of 88%, a specificity rate of 95%, a negative predictive value of 96%, and a positive predictive value of 84%. The slide centrifuge Gram stain is a very sensitive screening method to detect bacteriuria in an adult male population.

  1. Filtration of ultrafine metallic particles in industry.

    PubMed

    Bémer, D; Morele, Y; Régnier, R

    2015-01-01

    Thermal metal spraying, metal cutting and arc welding processes generate large quantities of ultrafine particles that cause the irreversible clogging of industrial filters. The aim of the study performed was to identify the causes of the clogging of cartridge filters and investigate other paths for cleaning them. This study required the development of a test bench capable of reproducing a thermal spraying process to test the performances of different filtration techniques. This test instrument first, permitted the precise characterization of the aerosol generated by the process and, second, defined the clogging and cleaning conditions for filters. Several parameters were tested: the type of filter, online and off-line cleaning, pre-coating, cleaning by jets of high-speed compressed air via a probe.

  2. Dynamical Systems, Cytokine Storms, and Blood Filtration

    NASA Astrophysics Data System (ADS)

    Foster, Glenn; Hubler, Alfred

    2008-03-01

    Various infections and non-infectious diseases can trigger immune cells and the proteins (cytokines) the cells use to communicate with each other to be caught in a positive feedback loop; this ``cytokine storm'' is frequently fatal. By examining the network of cytokine-immune cell interactions we will illustrate why anti-mediator drugs have been generally ineffective in stopping this feedback. A more effective approach may be to try and reduce interactions by dampening many signals at once by filtering the cytokines out of the blood directly (think dialysis). We will argue that feedback on an out of control nonlinear dynamical system is easier to understand than its normal healthy state and apply filtration to a toy model of immune response.

  3. Membraneless water filtration using CO2

    NASA Astrophysics Data System (ADS)

    Shin, Sangwoo; Shardt, Orest; Warren, Patrick; Stone, Howard

    2016-11-01

    Water purification technologies such as ultrafiltration and reverse osmosis utilize porous membranes to remove suspended particles and solutes. These membranes, however, cause many drawbacks such as a high pumping cost and a need for periodic replacement due to fouling. Here we show an alternative membraneless method for separating suspended particles by exposing the colloidal suspension to CO2. Dissolution of CO2 into the suspension creates solute gradients that drive phoretic motion of particles, or so-called diffusiophoresis. Due to the large diffusion potential built up by the dissociation of carbonic acid, colloidal particles move either away from or towards the gas-liquid interface depending on their surface charge. Our findings suggest a means to separate particles without membranes or filters, thus reducing operating and maintenance costs. Using the directed motion of particles induced by exposure to CO2, we demonstrate a scalable, continuous flow, membraneless particle filtration process that exhibits very low pressure drop and is essentially free from fouling.

  4. Dynamics and filtration of microgel suspensions

    NASA Astrophysics Data System (ADS)

    Naegele, Gerhard; Roa, Rafael; Riest, Jonas

    Microgel suspensions exhibit interesting transport properties determined by direct and hydrodynamic interactions. Using an annulus model to account for solvent permeability, we calculate the diffusion function and sedimentation coefficient of PNiPAM microgel suspensions, in excellent agreement with experimental results. Moreover, an extension of our precise analytic methods to long-time properties including viscosity and self-diffusion coefficient is presented, with results compared to simulation and experimental data. The predicted transport properties are an important ingredient to the modeling of convective-diffusive transport in membrane ultrafiltration of permeable particles. The efficiency of the separation process depends on hydrodynamic boundary conditions, membrane properties and particle interactions. We calculate the concentration polarization layer and permeate flux at different operating conditions for cross-flow ultrafiltration of non-ionic and ionic microgels. Small microgel permeability already affects the filtration significantly.

  5. Filtration test of sunflower oil for fuel

    SciTech Connect

    Olson, J.C.; Backer, L.F.

    1983-01-01

    A filtration system was developed to test for particulate matter in 1.6 liter samples of fuel. Four micron, absolute, filter paper was used. Four alkali refined sunflower oils, two of which were also dewaxed, were tested along with 50:50% and 25:75% blends with No. 2-D diesel fuel. The two sunflower oils that were not dewaxed were darker and cloudier than the dewaxed oils and clogged the test filter in less than 10 minutes. Clogging also occurred for the 50:50% and 25:75% blends of these oils at all temperatures and pressures tested. The two dewaxed sunflower oils did not clog the filter in the ten minute tests. The flow rates of the latter two oils and their blends decreased only slightly with time.

  6. Hierarchical analysis of filtration. Progress report

    SciTech Connect

    Quintard, M.; Whitaker, S.

    1993-07-01

    The original proposal for this work suggested two lines Of analysis that could be used to develop an hierarchical analysis of filtration. The first of these was semi-empirical and required the use of an angle-dependent rate coefficient to model the effect of particle inertia, while the second made use of a particle velocity decomposition that separated the velocity into an inertial part and a diffusive part. We have concluded that the semiempirical approach cannot lead to an efficient treatment of the filtration problem, and in this study we have dirrcted most of our effort toward the development of the velocity decomposition approach. Problems arise with the velocity decomposition method because the panicle tracking equation is hyperbolic in nature, and there are regions in the flow field where it is difficult to calculate the deterministic particle velocity. These problems can be avoided with an asymptotic analysis, and we have used this approach to determine single fiber efficiencies for small Stokes numbers. These efficiencies illustrate a minimum as a function of the particle diameter; however, the range of validity (in terms of the Stokes number) of the asymptotic method is uncertain. If the range of validity of the asymptotic expansion is suitable for the solution of practical problems, the current work on homogeneous filters should be expanded to included a broader range of values of the key parameters and then extended to include the case of heterogeneous filters. If the range of validity of the asymptotic method is not suitable for the solution of practical problems, the particle tracking problem must be resolved or we must move on to the use of Brownian dynamics. This approach is outlined, where we have indicated how Brownian dynamics may be incorporated into the method of volume averaging.

  7. Loading and filtration characteristics of filtering facepieces.

    PubMed

    Chen, C C; Lehtimäki, M; Willeke, K

    1993-02-01

    Most filtering facepieces used today are made of electret material (material with significant electrical charges on the filter fibers). Because of the addition of this electrical removal force, the filtration efficiency can be significantly increased without increasing the air pressure drop inside the respirator; pressure drop is closely related to physiological load. However, the removal by electrical forces is reduced in time, as aerosols deposit on the filter fibers. We have studied the contribution of this electrical removal and its change in time as a function of aerosol loading. To prove the change in aerosol penetration is due to the reduction of electrical force, the electrical charges were removed from new facepieces by the application of appropriate chemicals. The dust-mist filtering facepieces tested have similar fiber diameters and packing densities, as determined by scanning electron microscopy and pressure drop data. At a face velocity of 10 cm/s (corresponding to 100 L/min through a complete filtering facepiece) and an aerosol size of 0.16 microns, electrical force removal accounts for 69% of the total filtration for the respirator found to have the best filter quality but only 25% for the respirator (from a different manufacturer) found to have the worst filter quality. Our experimental data show that the removal efficiency of these facepieces is reduced in time by as much as this amount. However, under normal wear conditions, the total aerosol particle load is not as high as shown and the filtering facepieces are likely to be discarded before the fiber charges (i.e., the electrostatic attractions) are significantly diminished.

  8. Fabrication of Al/Diamond Particles Functionally Graded Materials by Centrifugal Sintered-Casting Method

    NASA Astrophysics Data System (ADS)

    Watanabe, Yoshimi; Shibuya, Masafumi; Sato, Hisashi

    2013-03-01

    The continuous graded structure of functionally graded materials (FGMs) can be created under a centrifugal force. Centrifugal sintered-casting (CSC) method, proposed by the authors, is one of the fabrication methods of FGM under centrifugal force. This method is a combination of the centrifugal sintering method and centrifugal casting method. In this study, Al/diamond particle FGM was fabricated by the proposed method.

  9. Cerebral Hypoperfusion Precedes Nausea During Centrifugation

    NASA Technical Reports Server (NTRS)

    Serrador, Jorge M.; Schlegel, Todd T.; Black, F. Owen; Wood, Scott J.

    2004-01-01

    Nausea and motion sickness are important operational concerns for aviators and astronauts. Understanding underlying mechanisms associated with motion sickness may lead to new treatments. The goal of this work was to determine if cerebral blood flow changes precede the development of nausea in motion sick susceptible subjects. Cerebral flow velocity in the middle cerebral artery (transcranial Doppler), blood pressure (Finapres) and end-tidal CO2 were measured while subjects were rotated on a centrifuge (250 degrees/sec). Following 5 min of rotation, subjects were translated 0.504 m off-center, creating a +lGx centripetal acceleration in the nasal-occipital plane. Ten subjects completed the protocol without symptoms while 5 developed nausea (4 while 6ff-center and 1 while rotating on-center). Prior to nausea, subjects had significant increases in blood pressure (+13plus or minus 3 mmHg, P less than 0.05) and cerebrovascular resistance (+46 plus or minus 17%, P less than 0.05) and decreases in cerebral flow velocity both in the second (-13 plus or minus 4%) and last minute (-22 plus or minus 5%) before symptoms (P less than 0.05). In comparison, controls demonstrated no change in blood pressure or cerebrovascular resistance in the last minute of off-center rotation and only a 7 plus or minus 2% decrease in cerebral flow velocity. All subjects had significant hypocapnia (-3.8 plus or minus 0.4 mmHg, P less than 0.05), however this hypocapnia could not fully explain the cerebral hypoperfusion associated with the development of nausea. These data indicate that reductions in cerebral blood flow precede the development of nausea. Further work is necessary to determine what role cerebral hypoperfusion plays in motion sickness and whether cerebral hypoperfusion can be used to predict the development of nausea in susceptible individuals.

  10. Vibrating membrane filtration as improved technology for microalgae dewatering.

    PubMed

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

    2014-04-01

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

  11. STORMWATER TREATMENT AT CRITICAL AREAS: EVALUATION OF FILTRATION MEDIA

    EPA Science Inventory

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

  12. RIVERBANK FILTRATION: FATE OF DBP PRECURSORS AND SELECTED MICROORGANISMS

    EPA Science Inventory

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

  13. 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...

  14. Purification of contaminated water by filtration through porous glass

    NASA Technical Reports Server (NTRS)

    Wydeven, T.; Leban, M. I.

    1972-01-01

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

  15. 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...

  16. 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...

  17. 40 CFR 141.171 - Criteria for avoiding filtration.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

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

  18. 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...

  19. 40 CFR 141.719 - Additional filtration toolbox components.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...) WATER PROGRAMS (CONTINUED) NATIONAL PRIMARY DRINKING WATER REGULATIONS Enhanced Treatment for... separate stage of filtration if both filtration stages treat entire plant flow taken from a surface water or GWUDI source and no disinfectant residual is present in the influent water to the slow...

  20. 40 CFR 141.719 - Additional filtration toolbox components.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...) WATER PROGRAMS (CONTINUED) NATIONAL PRIMARY DRINKING WATER REGULATIONS Enhanced Treatment for... separate stage of filtration if both filtration stages treat entire plant flow taken from a surface water or GWUDI source and no disinfectant residual is present in the influent water to the slow...

  1. 40 CFR 141.719 - Additional filtration toolbox components.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...) WATER PROGRAMS (CONTINUED) NATIONAL PRIMARY DRINKING WATER REGULATIONS Enhanced Treatment for... separate stage of filtration if both filtration stages treat entire plant flow taken from a surface water or GWUDI source and no disinfectant residual is present in the influent water to the slow...

  2. 40 CFR 141.719 - Additional filtration toolbox components.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...) WATER PROGRAMS (CONTINUED) NATIONAL PRIMARY DRINKING WATER REGULATIONS Enhanced Treatment for... separate stage of filtration if both filtration stages treat entire plant flow taken from a surface water or GWUDI source and no disinfectant residual is present in the influent water to the slow...

  3. 40 CFR 141.719 - Additional filtration toolbox components.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...) WATER PROGRAMS (CONTINUED) NATIONAL PRIMARY DRINKING WATER REGULATIONS Enhanced Treatment for... separate stage of filtration if both filtration stages treat entire plant flow taken from a surface water or GWUDI source and no disinfectant residual is present in the influent water to the slow...

  4. PDADMAC flocculation of Chinese hamster ovary cells: enabling a centrifuge-less harvest process for monoclonal antibodies.

    PubMed

    McNerney, Thomas; Thomas, Anne; Senczuk, Anna; Petty, Krista; Zhao, Xiaoyang; Piper, Rob; Carvalho, Juliane; Hammond, Matthew; Sawant, Satin; Bussiere, Jeanine

    2015-01-01

    High titer (>10 g/L) monoclonal antibody (mAb) cell culture processes are typically achieved by maintaining high viable cell densities over longer culture durations. A corresponding increase in the solids and sub-micron cellular debris particle levels are also observed. This higher burden of solids (≥15%) and sub-micron particles typically exceeds the capabilities of a continuous centrifuge to effectively remove the solids without a substantial loss of product and/or the capacity of the harvest filtration train (depth filter followed by membrane filter) used to clarify the centrate. We discuss here the use of a novel and simple two-polymer flocculation method used to harvest mAb from high cell mass cell culture processes. The addition of the polycationic polymer, poly diallyldimethylammonium chloride (PDADMAC) to the cell culture broth flocculates negatively-charged cells and cellular debris via an ionic interaction mechanism. Incorporation of a non-ionic polymer such as polyethylene glycol (PEG) into the PDADMAC flocculation results in larger flocculated particles with faster settling rate compared to PDADMAC-only flocculation. PDADMAC also flocculates the negatively-charged sub-micron particles to produce a feed stream with a significantly higher harvest filter train throughput compared to a typical centrifuged harvest feed stream. Cell culture process variability such as lactate production, cellular debris and cellular densities were investigated to determine the effect on flocculation. Since PDADMAC is cytotoxic, purification process clearance and toxicity assessment were performed.

  5. PDADMAC flocculation of Chinese hamster ovary cells: Enabling a centrifuge-less harvest process for monoclonal antibodies

    PubMed Central

    McNerney, Thomas; Thomas, Anne; Senczuk, Anna; Petty, Krista; Zhao, Xiaoyang; Piper, Rob; Carvalho, Juliane; Hammond, Matthew; Sawant, Satin; Bussiere, Jeanine

    2015-01-01

    High titer (>10 g/L) monoclonal antibody (mAb) cell culture processes are typically achieved by maintaining high viable cell densities over longer culture durations. A corresponding increase in the solids and sub-micron cellular debris particle levels are also observed. This higher burden of solids (≥15%) and sub-micron particles typically exceeds the capabilities of a continuous centrifuge to effectively remove the solids without a substantial loss of product and/or the capacity of the harvest filtration train (depth filter followed by membrane filter) used to clarify the centrate. We discuss here the use of a novel and simple two-polymer flocculation method used to harvest mAb from high cell mass cell culture processes. The addition of the polycationic polymer, poly diallyldimethylammonium chloride (PDADMAC) to the cell culture broth flocculates negatively-charged cells and cellular debris via an ionic interaction mechanism. Incorporation of a non-ionic polymer such as polyethylene glycol (PEG) into the PDADMAC flocculation results in larger flocculated particles with faster settling rate compared to PDADMAC-only flocculation. PDADMAC also flocculates the negatively-charged sub-micron particles to produce a feed stream with a significantly higher harvest filter train throughput compared to a typical centrifuged harvest feed stream. Cell culture process variability such as lactate production, cellular debris and cellular densities were investigated to determine the effect on flocculation. Since PDADMAC is cytotoxic, purification process clearance and toxicity assessment were performed. PMID:25706650

  6. Air cooled turbine component having an internal filtration system

    DOEpatents

    Beeck, Alexander R [Orlando, FL

    2012-05-15

    A centrifugal particle separator is provided for removing particles such as microscopic dirt or dust particles from the compressed cooling air prior to reaching and cooling the turbine blades or turbine vanes of a turbine engine. The centrifugal particle separator structure has a substantially cylindrical body with an inlet arranged on a periphery of the substantially cylindrical body. Cooling air enters centrifugal particle separator through the separator inlet port having a linear velocity. When the cooling air impinges the substantially cylindrical body, the linear velocity is transformed into a rotational velocity, separating microscopic particles from the cooling air. Microscopic dust particles exit the centrifugal particle separator through a conical outlet and returned to a working medium.

  7. [The analytical setting of rotary speed of centrifuge rotor and centrifugation time in chemical, biochemical and microbiological practice].

    PubMed

    Zolotarev, K V

    2012-08-01

    The researchers happen to face with suspensions in their chemical, biochemical and microbiological practice. The suspensions are the disperse systems with solid dispersed phase and liquid dispersion medium and with dispersed phase particle size > 100 nm (10-7 m). Quite often the necessity occurs to separate solid particles from liquid. To use for this purpose the precipitation in gravitation field can make the process to progress too long. In this respect an effective mode is the precipitation in the field of centrifugal forces--the centrifugation. The rotary speed of centrifuge rotor and centrifugation time can be set analytically using regularities of general dynamics and hydrodynamics. To this effect, should be written and transformed the equation of First and Second Newton Laws for suspension particle being in the field of centrifugal forces and forces of resistance of liquid and vessel wall. The force of liquid resistance depends on particle motion condition in liquid. To determine the regimen the Archimedes and Reynolds numerical dimensionless criteria are to be applied. The article demonstrates the results of these transformations as analytical inverse ratio dependence of centrifugation time from rotary speed. The calculation of series of "rate-time" data permits to choose the optimal data pair on the assumption of centrifuge capacity and practical reasonability. The results of calculations are validated by actual experimental data hence the physical mathematical apparatus can be considered as effective one. The setting progress depends both from parameter (Reynolds criterion) and data series calculation. So, the most convenient way to apply this operation is the programming approach. The article proposes to use the program Microsoft Excel and VBA programming language for this purpose. The possibility to download the file from Internet to use it for fast solution is proposed.

  8. A fuzzy controlled three-phase centrifuge for waste separation

    SciTech Connect

    Parkinson, W.J.; Smith, R.E.; Miller, N.

    1998-02-01

    The three-phase centrifuge technology discussed in this paper was developed by Neal Miller, president of Centech, Inc. The three-phase centrifuge is an excellent device for cleaning up oil field and refinery wastes which are typically composed of hydrocarbons, water, and solids. The technology is unique. It turns the waste into salable oil, reusable water, and landfill-able solids. No secondary waste is produced. The problem is that only the inventor can set up and run the equipment well enough to provide an optimal cleanup. Demand for this device has far exceeded a one man operation. There is now a need for several centrifuges to be operated at different locations at the same time. This has produced a demand for an intelligent control system, one that could replace a highly skilled operator, or at least supplement the skills of a less experienced operator. The control problem is ideally suited to fuzzy logic, since the centrifuge is a highly complicated machine operated entirely by the skill and experience of the operator. A fuzzy control system was designed for and used with the centrifuge.

  9. Exosome enrichment of human serum using multiple cycles of centrifugation.

    PubMed

    Kim, Jeongkwon; Tan, Zhijing; Lubman, David M

    2015-09-01

    In this work, we compared the use of repeated cycles of centrifugation at conventional speeds for enrichment of exosomes from human serum compared to the use of ultracentrifugation (UC). After removal of cells and cell debris, a speed of 110 000 × g or 40 000 × g was used for the UC or centrifugation enrichment process, respectively. The enriched exosomes were analyzed using the bicinchoninic acid assay, 1D gel separation, transmission electron microscopy, Western blotting, and high-resolution LC-MS/MS analysis. It was found that a five-cycle repetition of UC or centrifugation is necessary for successful removal of nonexosomal proteins in the enrichment of exosomes from human serum. More significantly, 5× centrifugation enrichment was found to provide similar or better performance than 5× UC enrichment in terms of enriched exosome protein amount, Western blot band intensity for detection of CD-63, and numbers of identified exosome-related proteins and cluster of differentiation (CD) proteins. A total of 478 proteins were identified in the LC-MS/MS analyses of exosome proteins obtained from 5× UCs and 5× centrifugations including many important CD membrane proteins. The presence of previously reported exosome-related proteins including key exosome protein markers demonstrates the utility of this method for analysis of proteins in human serum.

  10. Development of a Feeder for Uninterrupted Centrifugation Studies

    NASA Technical Reports Server (NTRS)

    Mulenburg, Gerald M.; Vasques, Marilyn F.; Gundo, Daniel P.; Griffith, Jon B.; Wade, Charles E. (Technical Monitor)

    1994-01-01

    A specialized paste diet feeder was developed in support of a hypergravity (2G) centrifuge study. The centrifuge study was to be compared to a previously flown Russian Cosmos spaceflight so experimental parameters of the 14 day spaceflight had to be duplicated. In order to duplicate at hyper G an experiment that took place in weightlessness, all other conditions must be as identical as possible. Stopping the centrifuge to provide maintenance for the animals causes unacceptable changes in experimental research results. Thus the experimental protocol required the delivery of a designated amount of paste diet at regular intervals for a two week period without stopping the centrifuge. A centrifuge and a stationary control cage, each containing 10 laboratory rats, were fitted with feeders that were calibrated to provide 140 plus or minus 2g of paste diet every 6 hours. This paper describes development of the feeder design and results of its operation over the two week experiment. The design philosophy and details of the feeder system are provided with recommendations for future such devices.

  11. Centrifuges and Their Application for Biological Experiments in Space

    NASA Astrophysics Data System (ADS)

    Brinckmann, Enno

    2012-12-01

    The need for an in-orbit 1×g control originated from the fact that Space radiation or other environmental factors of Space flight could not be excluded as cause for the effects on biological systems that were mainly interpreted as effects of the weightlessness environment. Indeed, in many experiments the 1×g reference centrifuge on board revealed the same data as the 1×g controls on ground, proving the lack of gravity was causing the results. In other cases, the reference centrifuge data were intermediate or clearly different to the ground data which was either due to interrupted 1×g conditions on board or to other, sometimes not well understood factors. This triggered also the development of sophisticated hardware allowing the start, i.e. the transition from 1×g to 0×g, or the termination of the experiment without stopping the centrifuge. Recently developed facilities provide also a complete life support system on the centrifuge rotor. Besides the in-flight 1×g control, acceleration experiments required a centrifuge for determination of threshold values in orbit.

  12. Centrifugation Effects on Estrous Cycling, Mating Success and Pregnancy Outcome in Rats

    NASA Technical Reports Server (NTRS)

    Ronca, April E.; Rushing, Linda S.; Tou, Janet; Wade, Charles E.; Baer, Lisa A.

    2005-01-01

    We analyzed the effects of 2-g centrifugation on estrous cycling, mating success and pregnancy outcome in rats. Sexually mature female and male rats were assigned to either 2-g centrifuge or non-centrifuge conditions, and to non-breeding or breeding conditions. In non-breeding females, estrous cycles were analyzed by examining vaginal cytology before and for 35 days during centrifugation. Breeding females were time-mated following 7 days of adaptation to centrifugation. Following adaptation to centrifugation, estrous cycle duration over a five-cycle period was similar in centrifuged and non-centrifuged females. Identical numbers of centrifuged and non-centrifuged females conceived, however centrifuged females took four-times longer than controls to achieve conception. Births occurred at the normal gestational length. Pup birth weight and postnatal survival were p<0.05 reduced in centrifuged as compared to non-centrifuged groups. In conclusion, 2-g centrifugation had no effect on estrous cycle length or the probably of becoming pregnant but delayed conception and diminished pregnancy outcome.

  13. Centrifugation effects on estrous cycle, mating success and pregnancy outcome in rats

    NASA Astrophysics Data System (ADS)

    Ronca, April E.; Rushing, Linda; Tou, Janet; Wade, Charles E.; Baer, Lisa A.

    2005-08-01

    We analyzed the effects of 2-g centrifugation on estrous cycling, mating success and pregnancy outcome in rats. Sexually mature female and male rats were assigned to either 2-g centrifuge or non-centrifuge conditions, and to non-breeding or breeding conditions. In non-breeding females, estrous cycles were analyzed by examining vaginal cytology before and for 35 days during centrifugation. Breeding females were time-mated following 7 days of adaptation to centrifugation. Following adaptation to centrifugation, estrous cycle duration over a five-cycle period was similar in centrifuged and non-centrifuged females. Identical numbers of centrifuged and non-centrifuged females conceived, however centrifuged females took four-times longer than controls to achieve conception. Births occurred at the normal gestational length. Pup birth weight and postnatal survival were p<0.05 reduced in centrifuged as compared to non-centrifuged groups. In conclusion, 2-g centrifugation had no effect on estrus cycle length or the probably of becoming pregnant but delayed conception and diminished pregnancy outcome.

  14. Sorghum genome sequencing by methylation filtration.

    PubMed

    Bedell, Joseph A; Budiman, Muhammad A; Nunberg, Andrew; Citek, Robert W; Robbins, Dan; Jones, Joshua; Flick, Elizabeth; Rholfing, Theresa; Fries, Jason; Bradford, Kourtney; McMenamy, Jennifer; Smith, Michael; Holeman, Heather; Roe, Bruce A; Wiley, Graham; Korf, Ian F; Rabinowicz, Pablo D; Lakey, Nathan; McCombie, W Richard; Jeddeloh, Jeffrey A; Martienssen, Robert A

    2005-01-01

    Sorghum bicolor is a close relative of maize and is a staple crop in Africa and much of the developing world because of its superior tolerance of arid growth conditions. We have generated sequence from the hypomethylated portion of the sorghum genome by applying methylation filtration (MF) technology. The evidence suggests that 96% of the genes have been sequence tagged, with an average coverage of 65% across their length. Remarkably, this level of gene discovery was accomplished after generating a raw coverage of less than 300 megabases of the 735-megabase genome. MF preferentially captures exons and introns, promoters, microRNAs, and simple sequence repeats, and minimizes interspersed repeats, thus providing a robust view of the functional parts of the genome. The sorghum MF sequence set is beneficial to research on sorghum and is also a powerful resource for comparative genomics among the grasses and across the entire plant kingdom. Thousands of hypothetical gene predictions in rice and Arabidopsis are supported by the sorghum dataset, and genomic similarities highlight evolutionarily conserved regions that will lead to a better understanding of rice and Arabidopsis.

  15. Capturing phosphates with iron enhanced sand filtration.

    PubMed

    Erickson, Andrew J; Gulliver, John S; Weiss, Peter T

    2012-06-01

    Most treatment practices for urban runoff capture pollutants such as phosphorus by either settling or filtration while dissolved phosphorus, typically as phosphates, is untreated. Dissolved phosphorus, however, represents an average 45% of total phosphorus in stormwater runoff and can be more than 95%. In this study, a new stormwater treatment technology to capture phosphate, called the Minnesota Filter, is introduced. The filter comprises iron filings mixed with sand and is tested for phosphate removal from synthetic stormwater. Results indicate that sand mixed with 5% iron filings captures an average of 88% phosphate for at least 200 m of treated depth, which is significantly greater than a sand filter without iron filings. Neither incorporation of iron filings into a sand filter nor capture of phosphates onto iron filings in column experiments had a significant effect on the hydraulic conductivity of the filter at mixtures of 5% or less iron by weight. Field applications with up to 10.7% iron were operated over 1 year without detrimental effects upon hydraulic conductivity. A model is applied and fit to column studies to predict the field performance of iron-enhanced sand filters. The model predictions are verified through the predicted performance of the filters in removing phosphates in field applications. Practical applications of the technology, both existing and proposed, are presented so stormwater managers can begin implementation.

  16. Gravity filtration of suspensions: permeability effects

    NASA Astrophysics Data System (ADS)

    Soori, Tejaswi; Wang, Mengyu; Ward, Thomas

    2015-11-01

    This paper examines the filtration rates of mono-modal suspensions as a function of time and a cake layer builds up through theory and experimentation. Darcy's Law, which describes fluid flow through porous media, was applied along with the Kynch theory of sedimentation, which provides the basis for analyzing low concentration (ϕ <=20%) cake formation. Experiments were performed to study the effects of varying particle sizes (45 μm <= d <= 1400 μm) and total solid concentration ϕ on both the formation rate of the cake layer and its flow permeability (k) in conjunction with the filter media. A CCD camera was used to capture images of the cake formation and fluid drainage processes, and subsequent image and theoretical analysis found the fluid flow experienced a constant pressure loss due to the permeability of the filter media, whereas the experienced pressure loss due to the cake formation varies as a function of time, ϕ and d. The rate of cake formation was also found to be independent of ϕ but dependent on d which can be attributed to a change in porosity affecting permeability. Studies on similar systems with multi-modal suspensions are in-progress.

  17. Automated filtration capture immunoelectrochemical assay of bacteria

    NASA Astrophysics Data System (ADS)

    Brewster, Jeffrey D.

    1999-01-01

    An automated system for filtration capture and immunoelectrochemical detection of bactria in liquid samples is described. The detector incorporates a porous electrode in contact with the filter, rather than the solid electrode used previously, to allow sample and reagent solutions to be delivered in a flowing stream. This eliminated the need for manual assembly of the electrode and filter for each assay and allowed repetitive assays on a single filter/electrode. The electrochemical response of the novel gold grid electrode under static and flow conditions was found to be consistent with theory for a planar electrode operating in laminar flow conditions. A computer-controlled fluid handling system was coupled to the detector for delivery of samples and reagents at controlled flow rates and times. The combination of flow detector and fluid handling system allows for automation of the previous assay protocol as well as providing new operating modes with enhanced background rejection and improved sensitivity. The use of these operating modes is demonstrated by a simple assay for Escherichia coli O157:H7 with virtually no background current.

  18. Filtration application from recycled expanded polystyrene.

    PubMed

    Shin, C

    2006-10-01

    Water-in-oil emulsion with drop size less than 100 mum is difficult to separate. Coalescence filtration is economical and effective for separation of secondary dispersions. Coalescence performance depends on flow rate, bed depth, fiber surface properties, and drop size. The amount of surface area of the fibers directly affects the efficiency. A new recycling method was investigated in the previous work in which polystyrene (PS) sub-mum fibers were electro-spun from recycled expanded polystyrene (EPS). These fibers are mixed with micro glass fibers to modify the glass fiber filter media. The filter media are tested in the separation of water droplets from an emulsion of water droplets in oil. The experimental results in this work show that adding nanofibers to conventional micron sized fibrous filter media improves the separation efficiency of the filter media but also increases the pressure drop. An optimum in the performance occurs (significant increase in efficiency with minimal increase in pressure drop) with the addition of about 4% by mass of 500 nm diameter PS nanofibers to glass fibers for the filters.

  19. Coal fired powerhouse wastewater pressure filtration

    SciTech Connect

    Martin, H.L.; Diener, G.A.

    1994-05-01

    The Savannah River Site`s permit for construction of an industrial wastewater treatment facility to remove solids from the boiler blow-down and wet ash scrubber effluent of the A-Area coal fired powerhouse was rejected. Conventional clarification technology would not remove arsenic from the combined effluent sufficient to achieve human health criteria in the small receiving surface stream. Treatability studies demonstrated that an existing facility, which will no longer be needed for metal finishing wastewater, can very efficiently process the powerhouse wastewater to less than 35 {mu}g/L arsenic. Use of cationic and anionic polymers to flocculate both the wastewater and filter aid solids formed a ``bridged cake`` with exceptionally low resistance to flow. This will double the capacity of the Oberlin pressure filters with the Tyvek T-980 sub micron filter media. The affects of high sheer agitation and high temperature in the raw wastewater on the filtration process were also studied and adequate controls were demonstrated.

  20. Analytical liquid test sample filtration apparatus

    DOEpatents

    Lohnes, Brent C.; Turner, Terry D.; Klingler, Kerry M.; Clark, Michael L.

    1996-01-01

    A liquid sample filtration apparatus includes: a) a module retaining filter elements; b) a filter clamping and fluid injection apparatus positioned relative to the module to engage a filter element thereon, and includes a pair of first and second opposing engageable members to sealing engage a filter element therebetween; c) an inlet tube connected to an opposing engageable member; d) an outlet tube connected to an opposing engageable member; e) a motor to move the module relative to the filter clamping and injection apparatus to register filter elements on the module to the clamping and injection apparatus; and f) a motor associated with the filter clamping and injection apparatus to move the opposing engageable members into substantial sealing fluid communication relative to a filter element on the module. An apparatus for engaging opposing ends of a filter element includes: a) a member having a recess configured to engage one end of a filter element, including a first fluid passage communicating with the recess to pass fluid between the recess and externally of the member; and b) a second member positioned in opposing juxtaposition relative to the other member, and having a projection sized and shaped to matingly fit within the other member recess, the second member projection including a second recess configured to engage the other end of the filter element, the second member including a second fluid passage communicating with the second recess to pass fluid between the second recess and externally of the second member.

  1. Analytical liquid test sample filtration apparatus

    DOEpatents

    Lohnes, B.C.; Turner, T.D.; Klingler, K.M.; Clark, M.L.

    1996-01-09

    A liquid sample filtration apparatus includes: (a) a module retaining filter elements; (b) a filter clamping and fluid injection apparatus positioned relative to the module to engage a filter element thereon, and includes a pair of first and second opposing engageable members to engage a filter element there between; (c) an inlet tube connected to an opposing engageable member; (d) an outlet tube connected to an opposing engageable member; (e) a motor to move the module relative to the filter clamping and injection apparatus to register filter elements on the module to the clamping and injection apparatus; and (f) a motor associated with the filter clamping and injection apparatus to move the opposing engageable members into substantial sealing fluid communication relative to a filter element on the module. An apparatus for engaging opposing ends of a filter element includes: (a) a member having a recess configured to engage one end of a filter element, including a first fluid passage communicating with the recess to pass fluid between the recess and externally of the member; and (b) a second member positioned in opposing juxtaposition relative to the other member, and having a projection sized and shaped to matingly fit within the other member recess, the second member projection including a second recess configured to engage the other end of the filter element, the second member including a second fluid passage communicating with the second recess to pass fluid between the second recess and externally of the second member. 8 figs.

  2. Improve filtration for optimum equipment reliability

    SciTech Connect

    Cervera, S.M.

    1996-01-01

    The introduction 20 years ago of the American Petroleum Institute Standard API-614 as a purchase specification for lubrication, shaft sealing and control oil systems, had a considerable impact and did much to improve system reliability at that time. Today, however, these recommendations regarding filter rating and flushing cleanliness are outdated. Much research in the tribology field correlates clearance size particulate contamination with accelerated component wear, fatigue and performance degradation. Some of these studies demonstrate that by decreasing the population of clearance size particulate in lubrication oils, component life increases exponentially. Knowing the dynamic clearances of a piece of machinery makes it possible, using the ISO 4406 Cleanliness Code, to determine what cleanliness level will minimize contamination-related component wear/fatigue and thus help optimize machinery performance and reliability. Data obtained by the author through random sampling of rotating equipment lube and seal oil systems indicate that the API-614 standard, as it pertains to filtration and flushing, is insufficient to ensure that particulate contamination is maintained to within the levels necessary to achieve optimum equipment reliability and safety, without increasing operating cost. Adopting and practicing the guidelines presented should result in the following benefits: (1) the frequency of bearing, oil pump, mechanical seal, fluid coupling, gearbox and hydraulic control valve failures would be minimized; (2) the mean time between planned maintenance (MTBPM) would be increased. The result will be a substantial increase in safety and cost savings to the operator.

  3. Radionuclide measurement of differential glomerular filtration rate

    SciTech Connect

    Powers, T.A.; Stone, W.J.; Grove, R.B.; Plunkett, J.M.; Kadir, S.; Patton, J.A.; Bowen, R.D.

    1981-01-01

    The authors sought to determine whether radionuclides could provide a reasonable estimate of differential renal function in five normal dogs and six dogs with unilateral segmental renal infarction. Glomerular filtration rate (GFR) of each kidney was measured by the standard technique using constant infusions of 99mTc-DTPA, iothalamate, and creatinine following ureteral catheterization. These results were correlated with total GFR estimated by bolus injection of 99mTc-DTPA and analysis of the plasma 99mTc-DTPA disappearance curve obtained by blood sampling. Differential GFR was then calculated by multiplying the total GFR from double exponential analysis of this curve (DTPA2) by each of three measures of differential function. These include the percent differential uptake of 99mTc-DTPA and 99mTc-DMSA in the posterior projection as well as the geometric mean of 99mTc-DMSA uptake. There were good correlations between differential GFR calculated from iothalamate clearances obtained at ureteral catheterization and all noninvasive methods involving radionuclides and DTPA2 (r = 0.85 - 0.99). Single exponential analysis of the 99mTc-DTPA plasma disappearance curve was less satisfactory. The authors suggest that measurement of total and differential GFR calculated from plasma clearance of 99mTc-DTPA and external counting may be a useful method with potential clinical applications.

  4. Thermophilic biotrickling filtration of ethanol vapors.

    PubMed

    Cox, H H; Sexton, T; Shareefdeen, Z M; Deshusses, M A

    2001-06-15

    The treatment of ethanol vapors in biotrickling filters for air pollution control was investigated. Two reactors were operated in parallel, one at ambient temperature (22 degrees C) and one at high temperature (53 degrees C). After a short adaptation phase, the removal of ethanol was similar in both reactors. At a bed contact time of 57 s, the elimination capacity exceeded 220 g m(-3) h(-1) at both temperatures. The experiments performed revealed that the process was most likely limited by biodegradation in the biofilm. The high-temperature biotrickling filter exhibited a higher degree of ethanol mineralization to CO2 (60 vs 46% at ambient temperature); hence, a lower rate of biomass accumulation was observed. Plating and cultivation of biofilm samples revealed that the high-temperature biotrickling filter hosted a process culture composed of both mesophilic and thermotolerant or thermophilic microorganisms, whereas the ambient-temperature reactor lacked microorganisms capable of growing at high temperature. Consequently, the performance of the control biotrickling filter was significantly affected by a short incursion at 53 degrees C. The upper temperature limit for treatment was 62 degrees C. Overall, the results of this study open new possibilities for biotrickling filtration of hot gases.

  5. 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.

  6. Rapid and Efficient Filtration-Based Procedure for Separation and Safe Analysis of CBRN Mixed Samples

    PubMed Central

    Bentahir, Mostafa; Laduron, Frederic; Irenge, Leonid; Ambroise, Jérôme; Gala, Jean-Luc

    2014-01-01

    Separating CBRN mixed samples that contain both chemical and biological warfare agents (CB mixed sample) in liquid and solid matrices remains a very challenging issue. Parameters were set up to assess the performance of a simple filtration-based method first optimized on separate C- and B-agents, and then assessed on a model of CB mixed sample. In this model, MS2 bacteriophage, Autographa californica nuclear polyhedrosis baculovirus (AcNPV), Bacillus atrophaeus and Bacillus subtilis spores were used as biological agent simulants whereas ethyl methylphosphonic acid (EMPA) and pinacolyl methylphophonic acid (PMPA) were used as VX and soman (GD) nerve agent surrogates, respectively. Nanoseparation centrifugal devices with various pore size cut-off (30 kD up to 0.45 µm) and three RNA extraction methods (Invisorb, EZ1 and Nuclisens) were compared. RNA (MS2) and DNA (AcNPV) quantification was carried out by means of specific and sensitive quantitative real-time PCRs (qPCR). Liquid chromatography coupled to time-of-flight mass spectrometry (LC/TOFMS) methods was used for quantifying EMPA and PMPA. Culture methods and qPCR demonstrated that membranes with a 30 kD cut-off retain more than 99.99% of biological agents (MS2, AcNPV, Bacillus Atrophaeus and Bacillus subtilis spores) tested separately. A rapid and reliable separation of CB mixed sample models (MS2/PEG-400 and MS2/EMPA/PMPA) contained in simple liquid or complex matrices such as sand and soil was also successfully achieved on a 30 kD filter with more than 99.99% retention of MS2 on the filter membrane, and up to 99% of PEG-400, EMPA and PMPA recovery in the filtrate. The whole separation process turnaround-time (TAT) was less than 10 minutes. The filtration method appears to be rapid, versatile and extremely efficient. The separation method developed in this work constitutes therefore a useful model for further evaluating and comparing additional separation alternative procedures for a safe handling and

  7. Rapid and efficient filtration-based procedure for separation and safe analysis of CBRN mixed samples.

    PubMed

    Bentahir, Mostafa; Laduron, Frederic; Irenge, Leonid; Ambroise, Jérôme; Gala, Jean-Luc

    2014-01-01

    Separating CBRN mixed samples that contain both chemical and biological warfare agents (CB mixed sample) in liquid and solid matrices remains a very challenging issue. Parameters were set up to assess the performance of a simple filtration-based method first optimized on separate C- and B-agents, and then assessed on a model of CB mixed sample. In this model, MS2 bacteriophage, Autographa californica nuclear polyhedrosis baculovirus (AcNPV), Bacillus atrophaeus and Bacillus subtilis spores were used as biological agent simulants whereas ethyl methylphosphonic acid (EMPA) and pinacolyl methylphophonic acid (PMPA) were used as VX and soman (GD) nerve agent surrogates, respectively. Nanoseparation centrifugal devices with various pore size cut-off (30 kD up to 0.45 µm) and three RNA extraction methods (Invisorb, EZ1 and Nuclisens) were compared. RNA (MS2) and DNA (AcNPV) quantification was carried out by means of specific and sensitive quantitative real-time PCRs (qPCR). Liquid chromatography coupled to time-of-flight mass spectrometry (LC/TOFMS) methods was used for quantifying EMPA and PMPA. Culture methods and qPCR demonstrated that membranes with a 30 kD cut-off retain more than 99.99% of biological agents (MS2, AcNPV, Bacillus Atrophaeus and Bacillus subtilis spores) tested separately. A rapid and reliable separation of CB mixed sample models (MS2/PEG-400 and MS2/EMPA/PMPA) contained in simple liquid or complex matrices such as sand and soil was also successfully achieved on a 30 kD filter with more than 99.99% retention of MS2 on the filter membrane, and up to 99% of PEG-400, EMPA and PMPA recovery in the filtrate. The whole separation process turnaround-time (TAT) was less than 10 minutes. The filtration method appears to be rapid, versatile and extremely efficient. The separation method developed in this work constitutes therefore a useful model for further evaluating and comparing additional separation alternative procedures for a safe handling and

  8. Centrifuge Techniques and Apparatus for Transport Experiments in Porous Media

    SciTech Connect

    Earl D. Mattson; Carl D. Paler; Robert W. Smith; Markus Flury

    2010-06-01

    This paper describes experimental approaches and apparatus that we have developed to study solute and colloid transport in porous media using Idaho National Laboratory's 2-m radius centrifuge. The ex-perimental techniques include water flux scaling with applied acceleration at the top of the column and sub-atmospheric pressure control at the column base, automation of data collection, and remote experimental con-trol over the internet. These apparatus include a constant displacement piston pump, a custom designed liquid fraction collector based on switching valve technology, and modified moisture monitoring equipment. Suc-cessful development of these experimental techniques and equipment is illustrated through application to transport of a conservative tracer through unsaturated sand column, with centrifugal acceleration up to 40 gs. Development of such experimental equipment that can withstand high accelerations enhances the centrifuge technique to conduct highly controlled unsaturated solute/colloid transport experiments and allows in-flight liquid sample collection of the effluent.

  9. Oscillatory Counter-Centrifugation: Effects of History and Lift Forces

    NASA Astrophysics Data System (ADS)

    Nadim, Ali

    2014-11-01

    This work is co-authored with my doctoral student Shujing Xu and is dedicated to the memory of my doctoral advisor Howard Brenner who enjoyed thought experiments related to rotating systems. Oscillatory Counter-Centrifugation refers to our theoretical discovery that within a liquid-filled container that rotates in an oscillatory manner about a fixed axis as a rigid body, a suspended particle can be made to migrate on average in the direction opposite to that of ordinary centrifugation. That is, a heavy (or light) particle can move toward (or away from) the rotation axis, when the frequency of oscillations is high enough. In this work we analyze the effects of the Basset history force and the Saffman lift force on particle trajectories and find that the counter-centrifugation phenomenon persists even when these forces are active.

  10. Space Station Centrifuge: A Requirement for Life Science Research

    NASA Technical Reports Server (NTRS)

    Smith, Arthur H.; Fuller, Charles A.; Johnson, Catherine C.; Winget, Charles M.

    1992-01-01

    A centrifuge with the largest diameter that can be accommodated on Space Station Freedom is required to conduct life science research in the microgravity environment of space. (This was one of the findings of a group of life scientists convened at the University of California, Davis, by Ames Research Center.) The centrifuge will be used as a research tool to understand how gravity affects biological processes; to provide an on-orbit one-g control; and to assess the efficacy of using artificial gravity to counteract the deleterious biological effect of space flight. The rationale for the recommendation and examples of using ground-based centrifugation for animal and plant acceleration studies are presented. Included are four appendixes and an extensive bibliography of hypergravity studies.

  11. Centrifugally activated bearing for high-speed rotating machinery

    DOEpatents

    Post, R.F.

    1994-02-15

    A centrifugally activated bearing is disclosed. The bearing includes an annular member that extends laterally and radially from a central axis. A rotating member that rotates about the central axis relative to the annular member is also included. The rotating member has an interior chamber that surrounds the central axis and in which the annular member is suspended. Furthermore, the interior chamber has a concave shape for retaining a lubricant therein while the rotating member is at rest and for retaining a lubricant therein while the rotating member is rotating. The concave shape is such that while the rotating member is rotating a centrifugal force causes a lubricant to be forced away from the central axis to form a cylindrical surface having an axis collinear with the central axis. This centrifugally displaced lubricant provides restoring forces to counteract lateral displacement during operation. 4 figures.

  12. Operation effectiveness of wells by enhancing the electric- centrifugal pump

    NASA Astrophysics Data System (ADS)

    Zyatikov, P. N.; Kozyrev, I. N.; Deeva, V. S.

    2016-09-01

    We present the method to improve the operation effectiveness of wells by enhancing the electric-centrifugal pump. Some of the best ways to extend the electric-centrifugal pumps operating lifetime is using today's techniques as well as additional protective equipment as a part of the electric-centrifugal pump. In paper it is shown that high corrosiveness of formation fluid (a multi-component medium composed of oil, produced water, free and dissolved gases) is a major cause of failures of downhole equipment. Coil tubing is the most efficient technology to deal with this problem. The experience of coil tubing operations has proved that high-quality bottom hole cleaning saving the cost of operation due to a decreased failure rate of pumps associated with ejection of mechanical impurity.

  13. Centrifugally activated bearing for high-speed rotating machinery

    DOEpatents

    Post, Richard F.

    1994-01-01

    A centrifugally activated bearing is disclosed. The bearing includes an annular member that extends laterally and radially from a central axis. A rotating member that rotates about the central axis relative to the annular member is also included. The rotating member has an interior chamber that surrounds the central axis and in which the annular member is suspended. Furthermore, the interior chamber has a concave shape for retaining a lubricant therein while the rotating member is at rest and for retaining a lubricant therein while the rotating member is rotating. The concave shape is such that while the rotating member is rotating a centrifugal force causes a lubricant to be forced away from the central axis to form a cylindrical surface having an axis collinear with the central axis. This centrifugally displaced lubricant provides restoring forces to counteract lateral displacement during operation.

  14. Design Optimization of a Centrifugal Fan with Splitter Blades

    NASA Astrophysics Data System (ADS)

    Heo, Man-Woong; Kim, Jin-Hyuk; Kim, Kwang-Yong

    2015-05-01

    Multi-objective optimization of a centrifugal fan with additionally installed splitter blades was performed to simultaneously maximize the efficiency and pressure rise using three-dimensional Reynolds-averaged Navier-Stokes equations and hybrid multi-objective evolutionary algorithm. Two design variables defining the location of splitter, and the height ratio between inlet and outlet of impeller were selected for the optimization. In addition, the aerodynamic characteristics of the centrifugal fan were investigated with the variation of design variables in the design space. Latin hypercube sampling was used to select the training points, and response surface approximation models were constructed as surrogate models of the objective functions. With the optimization, both the efficiency and pressure rise of the centrifugal fan with splitter blades were improved considerably compared to the reference model.

  15. Solvent-free cleaning using a centrifugal cryogenic pellet accelerator

    SciTech Connect

    Haines, J.R.; Fisher, P.W.; Foster, C.A.

    1995-06-01

    An advanced centrifuge that accelerates frozen CO{sub 2} pellets to high speeds for surface cleaning and paint removal is being developed at the Oak Ridge National Laboratory. The centrifuge-based accelerator was designed, fabricated, and tested under a program sponsored by the Warner Robins Air Logistics Center, Robins Air Force Base, Georgia. In comparison to the more conventional compressed air ``sandblast`` pellet accelerators, the centrifugal accelerator system can achieve higher pellet speeds, has precise speed control, and is more than ten times as energy efficient. Furthermore, the use of frozen CO{sub 2} pellets instead of conventional metal, plastic, sand, or other abrasive materials that remain solid at room temperature, minimizes the waste stream. This apparatus has been used to demonstrate cleaning of various surfaces, including removal of paint, oxide coatings, metal coatings, organic coatings, and oil and grease coatings from a variety of surfaces. The design and operation of the apparatus is discussed.

  16. Passively Shunted Piezoelectric Damping of Centrifugally-Loaded Plates

    NASA Technical Reports Server (NTRS)

    Duffy, Kirsten P.; Provenza, Andrew J.; Trudell, Jeffrey J.; Min, James B.

    2009-01-01

    Researchers at NASA Glenn Research Center have been investigating shunted piezoelectric circuits as potential damping treatments for turbomachinery rotor blades. This effort seeks to determine the effects of centrifugal loading on passively-shunted piezoelectric - damped plates. Passive shunt circuit parameters are optimized for the plate's third bending mode. Tests are performed both non-spinning and in the Dynamic Spin Facility to verify the analysis, and to determine the effectiveness of the damping under centrifugal loading. Results show that a resistive shunt circuit will reduce resonant vibration for this configuration. However, a tuned shunt circuit will be required to achieve the desired damping level. The analysis and testing address several issues with passive shunt circuit implementation in a rotating system, including piezoelectric material integrity under centrifugal loading, shunt circuit implementation, and tip mode damping.

  17. Biorefinery concept in a microalgae pilot plant. Culturing, dynamic filtration and steam explosion fractionation.

    PubMed

    Nurra, C; Torras, C; Clavero, E; Ríos, S; Rey, M; Lorente, E; Farriol, X; Salvadó, J

    2014-07-01

    A 53 m(3) microalgae pilot plant with semi-closed photobioreactors has been operated in batch mode at Tarragona, where proper climatic conditions exist. Operations carried-out were microalgae culturing, concentration, cell disruption and lipid extraction. Culturing was performed with and without CO2 fertilization. pH was used to control CO2 dosing. With CO2 fertilization best microalgae concentrations were obtained. Productivities up to 19.9 g/m(2)/day were reached. Although sedimentation and centrifugation was performed, studies focused on dynamic membrane filtration as improved technique compared with conventional one. Significant fouling reduction was obtained by using a vibrational membrane setup. Cell disruption including product pre-extraction was performed by using steam explosion at moderate conditions, as novel technique for this application. Lipid extraction was performed by using conventional techniques with and without exploded material. The amount of lipids obtained from exploded material was higher than with non-exploded material, which shows that steam explosion provides a clear enhancement.

  18. Separation of in-vitro-derived megakaryocytes and platelets using spinning-membrane filtration.

    PubMed

    Schlinker, Alaina C; Radwanski, Katherine; Wegener, Christopher; Min, Kyungyoon; Miller, William M

    2015-04-01

    In-vitro-derived platelets (PLTs) could potentially overcome problems associated with donated PLTs, including contamination and alloimmunization. Although several groups have produced functional PLTs from stem cells in vitro, the challenge of developing this technology to yield transfusable PLT units has yet to be addressed. The asynchronous nature of in vitro PLT generation makes a single harvest point infeasible for collecting PLTs as soon as they are formed. The current standard of performing manual centrifugations to separate PLTs from nucleated cells at multiple points during culture is labor-intensive, imprecise, and difficult to standardize in accordance with current Good Manufacturing Practices (cGMP). In an effort to develop a more effective method, we adapted a commercially-available, spinning-membrane filtration device to separate in-vitro-derived PLTs from nucleated cells and recover immature megakaryocytes (MKs), the precursor cells to PLTs, for continued culture. Processing a mixture of in-vitro-derived MKs and PLTs on the adapted device yielded a pure PLT population and did not induce PLT pre-activation. MKs recovered from the separation process were unaffected with respect to viability and ploidy, and were able to generate PLTs after reseeding in culture. Being able to efficiently harvest in-vitro-derived PLTs brings this technology one step closer to clinical relevance.

  19. Comparison of two gel filtration chromatographic methods for the purification of Lily symptomless virus.

    PubMed

    Wang, Ruoyu; Wang, Jianhui; Li, Juan; Wang, Yun; Xie, Zhongkui; An, Lizhe

    2007-02-01

    Lily symptomless virus (LSV) occurs frequently in many Lilium species worldwide and often causes developmental abnormalities such as a smaller flower and lower bulb yield. In this study, two moderate and efficient gel filtration chromatography (GFC) methods was compared, these two techniques were, respectively, based on Superdex-200 HR and Sephacryl S-1000 SF. The products purified by the two methods were then characterized by measurements with UV-spectrophotometer, reverse transcriptase (RT)-PCR, transmission electron microscope (TEM), polyacrylamide gel electrophoresis (PAGE), Western blotting and matrix assisted laser desorption-ionisation/time-of-flight mass spectrometry (MALDI-TOF-MS). The final yield of purified LSV by the Superdex-200 HR GFC was 9.4 mg from 50 g of fresh infected tissues of Lanzhou lily. However, from the same amount tissues, only 5.6 mg of LSV were obtained by using Sephacryl S-1000 SF GFC. The Superdex-200 HR method was thus shown to be more suitable for the purification of LSV than the Sephacryl S-1000 SF GFC. The Superdex-200 HR method does not require costly equipment for density centrifugation and ultracentrifugation. Furthermore, it can provide an economical and efficient way to obtain purified products for the preparation of antibodies for serological diagnosis or LSV infection and related investigations.

  20. Control of centrifugal blood pump based on the motor current.

    PubMed

    Iijima, T; Inamoto, T; Nogawa, M; Takatani, S

    1997-07-01

    In this study, centrifugal pump performance was examined in a mock circulatory loop to derive an automatic pump rotational speed (rpm) control method. The pivot bearing supported sealless centrifugal pump was placed in the left ventricular apex to aorta bypass mode. The pneumatic pulsatile ventricle was used to simulate the natural ventricle. To simulate the suction effect in the ventricle, a collapsible rubber tube was placed in the inflow port of the centrifugal pump in series with the apex of the simulated ventricle. Experimentally, the centrifugal pump speed (rpm) was gradually increased to simulate the suction effect. The pump flow through the centrifugal pump measured by an electromagnetic flowmeter, the aortic pressure, and the motor current were continuously digitized at 100 Hz and stored in a personal computer. The analysis of the cross-spectral density between the pump flow and motor current waveforms revealed that 2 waveforms were highly correlated at the frequency range between 0 and 4 Hz, with the coherence and phase angles being close to 1.0 and 0 degree, respectively. The fast Fourier transform analysis of the motor current indicated that the second harmonic component of the motor current power density increased with the occurrence of the suction effect in the circuit. The ratio of the fundamental to the second harmonic component decreased less than 1.3 as the suction effect developed in the circuit. It is possible to detect and prevent the suction effect of the centrifugal blood pump in the natural ventricle through analysis of the motor current waveform.

  1. Centrifugal inertia effects in two-phase face seal films

    NASA Technical Reports Server (NTRS)

    Basu, P.; Hughes, W. F.; Beeler, R. M.

    1987-01-01

    A simplified, semianalytical model has been developed to analyze the effect of centrifugal inertia in two-phase face seals. The model is based on the assumption of isothermal flow through the seal, but at an elevated temperature, and takes into account heat transfer and boiling. Using this model, seal performance curves are obtained with water as the working fluid. It is shown that the centrifugal inertia of the fluid reduces the load-carrying capacity dramatically at high speeds and that operational instability exists under certain conditions. While an all-liquid seal may be starved at speeds higher than a 'critical' value, leakage always occurs under boiling conditions.

  2. Apparatus and method for centrifugation and robotic manipulation of samples

    NASA Technical Reports Server (NTRS)

    Vellinger, John C. (Inventor); Ormsby, Rachel A. (Inventor); Kennedy, David J. (Inventor); Thomas, Nathan A. (Inventor); Shulthise, Leo A. (Inventor); Kurk, Michael A. (Inventor); Metz, George W. (Inventor)

    2007-01-01

    A device for centrifugation and robotic manipulation of specimen samples, including incubating eggs, and uses thereof are provided. The device may advantageously be used for the incubation of avian, reptilian or any type of vertebrate eggs. The apparatus comprises a mechanism for holding samples individually, rotating them individually, rotating them on a centrifuge collectively, injecting them individually with a fixative or other chemical reagent, and maintaining them at controlled temperature, relative humidity and atmospheric composition. The device is applicable to experiments involving entities other than eggs, such as invertebrate specimens, plants, microorganisms and molecular systems.

  3. The effect of gas fraction on centrifugal pump

    NASA Astrophysics Data System (ADS)

    Zhu, Z. T.; Wang, Y.; Zhao, L. F.; Ning, C.; Xie, S. F.; Liu, Z. C.

    2015-01-01

    In order to study the multiphase flow field in M125 centrifugal pump, three-dimensional modeling was used for internal flow through three-dimensional software Pro/E. Then based on SST turbulence model combining with Rayleigh-Plesset cavitation model, and structured grid to simulate the hydraulic characteristics of volute and impeller within different gas conditions. The velocity, pressure and gas volume fraction distributions of the interior flow field of volute and impeller were obtained and analyzed, which revealed the effect of gas fractions on the flow characteristic of the centrifugal pump.

  4. The use of centrifugation to study early Drosophila embryogenesis

    NASA Technical Reports Server (NTRS)

    Abbott, M. K.; Spooner, B. S. (Principal Investigator)

    1993-01-01

    By the end of 10th nuclear cycle, the somatic nuclei of the Drosophila embryo have migrated to the periphery of the egg. Centrifugation of embryos did not result in the displacement of these nuclei, since cytoskeletal elements anchor them to the cortex. But, mild centrifugal forces displace the centrally located, nascent yolk nuclei. If this increased sensitivity to hypergravity occurs before the beginning of nuclear differentiation during cycle 8, when the nascent yolk and somatic nuclei physically separate, then it would mark the earliest functional difference between these two lineages.

  5. 24. RW Meyer Sugar Mill: 18761889. Centrifugal inner basket, 1879. ...

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

    24. RW Meyer Sugar Mill: 1876-1889. Centrifugal inner basket, 1879. Manufacturer, unknown. Supplied by Honolulu Iron Works, Honolulu, Hawaii, 1879. View: After sugar was granulated and cooled it was dried and drained, completely separating the sugar crystals from the molasses, in the centrifugal. Revolving at 1200 rpm the sugar charge was forced outward with the molasses flying through the holes in the brass lining. Dried sugar was left behind in the inner basket and was dug out by hand. - R. W. Meyer Sugar Mill, State Route 47, Kualapuu, Maui County, HI

  6. Multiplexed single-molecule force spectroscopy using a centrifuge

    PubMed Central

    Yang, Darren; Ward, Andrew; Halvorsen, Ken; Wong, Wesley P.

    2016-01-01

    We present a miniature centrifuge force microscope (CFM) that repurposes a benchtop centrifuge for high-throughput single-molecule experiments with high-resolution particle tracking, a large force range, temperature control and simple push-button operation. Incorporating DNA nanoswitches to enable repeated interrogation by force of single molecular pairs, we demonstrate increased throughput, reliability and the ability to characterize population heterogeneity. We perform spatiotemporally multiplexed experiments to collect 1,863 bond rupture statistics from 538 traceable molecular pairs in a single experiment, and show that 2 populations of DNA zippers can be distinguished using per-molecule statistics to reduce noise. PMID:26984516

  7. On the characteristics of centrifugal-reciprocating machines. [cryogenic coolers

    NASA Technical Reports Server (NTRS)

    Higa, W. H.

    1980-01-01

    A method of compressing helium gas for cryogenic coolers is presented which uses centrifugal force to reduce the forces on the connecting rod and crankshaft in the usual reciprocating compressor. This is achieved by rotating the piston-cylinder assembly at a speed sufficient for the centrifugal force on the piston to overcome the compressional force due to the working fluid. The rotating assembly is dynamically braked in order to recharge the working space with fluid. The intake stroke consists of decelerating the rotating piston-cylinder assembly and the exhaust stroke consists of accelerating the assembly.

  8. Deep eutectic solvents in countercurrent and centrifugal partition chromatography.

    PubMed

    Roehrer, Simon; Bezold, Franziska; García, Eva Marra; Minceva, Mirjana

    2016-02-19

    Deep eutectic solvents (DESs) were evaluated as solvents in centrifugal partition chromatography, a liquid-liquid chromatography separation technology. To this end, the partition coefficients of ten natural compounds of different hydrophobicity were determined in non-aqueous biphasic systems containing DES. The influence of the composition of DESs and the presence of water in the biphasic system on the partition coefficient were also examined. In addition, several process relevant physical properties of the biphasic system, such as the density and viscosity of the phases, were measured. A mixture of three to four hydrophobic compounds was successfully separated in a centrifugal partition extractor using a heptane/ethanol/DES biphasic system.

  9. Secondary Containment Design for a High Speed Centrifuge

    SciTech Connect

    Snyder, K.W.

    1999-03-01

    Secondary containment for high speed rotating machinery, such as a centrifuge, is extremely important for operating personnel safety. Containment techniques can be very costly, ungainly and time consuming to construct. A novel containment concept is introduced which is fabricated out of modular sections of polycarbonate glazed into a Unistrut metal frame. A containment study for a high speed centrifuge is performed which includes the development of parameters for secondary containment design. The Unistrut/polycarbonate shield framing concept is presented including design details and proof testing procedures. The economical fabrication and modularity of the design indicates a usefulness for this shielding system in a wide variety of containment scenarios.

  10. Filtration performance of microporous ceramic supports.

    PubMed

    Belouatek, Aissa; Ouagued, Abdellah; Belhakem, Mustapha; Addou, Ahmed

    2008-04-24

    The use of inorganic membranes in pollution treatment is actually limited by the cost of such membranes. Advantages of inorganic membranes are their chemical, thermal and pH properties. The purpose of this work was the development of microporous ceramic materials based on clay for liquid waste processing. The supports or ceramic filters having various compositions were prepared and thermally treated at 1100 degrees C. The results show that, at the temperature studied, porosity varied according to the support composition from 12% for the double-layered (ceramic) support to 47% for the activated carbon- filled support with a mean pore diameter between 0.8 and 1.3 microm, respectively. Volumes of 5 l of distilled water were filtered tangentially for 3 h under an applied pressure of 3.5 and 5.5 bar. The retention of tubular supports prepared was tested with molecules of varying size (Evans blue, NaCl and Sacharose). The study of the liquid filtration and flow through these supports showed that the retention rate depends on support composition and pore diameter, and solute molecular weight. The S1 support (mixture of barbotine and 1% (w/w) activated carbon) gave a flux for distilled water of 68 L/m2 h while the double-layered support resulted in a flux of 8 L/m2 h for the same solution at the pressure of 3.5 bar. At a pressure of 5.5 bar an increase in the distilled water flux through the various supports was observed. It was significant for the S1 support (230 L/m h).

  11. Experimental and Theoretical Study on Circular Disk Particles Suspended in Centrifugal and Non-Centrifugal Force Environments

    SciTech Connect

    Torii, Shuichi; Watanabe, Yoshimi; Tanaka, Satoyuki; Yano, Toshiaki; Iino, Naoko

    2008-02-15

    Theoretical and experimental studies are performed on suspension particle motion in Centrifugal and Non-Centrifugal Force Environment, i.e., in both an axially rotating drum and a stable liquid tank. The particle velocity of circular disks is measured by PTV (Particle Tracking Velocimetry) method and is predicted by BBO (Basset-Boussinesq-Ossen) equation. It is found that (1) as time progresses, one side of the disk in the axially rotating drum is attracted toward the drum wall and its velocity is affected by the rotating speed, (2) when the particle moves in the Stokes' regime, its velocity is linearly increased with the distance from the center of the drum, (3) in contrast, the autorotation of the disk occurs in the non-centrifugal force field, and (4) the corresponding drag coefficient in the low Reynolds number region is in good agreement with the theoretical value of the sphere.

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

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

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

  13. Conservation laws for two-phase filtration models

    NASA Astrophysics Data System (ADS)

    Baikov, V. A.; Ibragimov, N. H.; Zheltova, I. S.; Yakovlev, A. A.

    2014-02-01

    The paper is devoted to investigation of group properties of a one-dimensional model of two-phase filtration in porous medium. Along with the general model, some of its particular cases widely used in oil-field development are discussed. The Buckley-Leverett model is considered in detail as a particular case of the one-dimensional filtration model. This model is constructed under the assumption that filtration is one-dimensional and horizontally directed, the porous medium is homogeneous and incompressible, the filtering fluids are also incompressible. The model of "chromatic fluid" filtration is also investigated. New conservation laws and particular solutions are constructed using symmetries and nonlinear self-adjointness of the system of equations.

  14. Granular bed filtration of high temperature biomass gasification gas.

    PubMed

    Stanghelle, Daniel; Slungaard, Torbjørn; Sønju, Otto K

    2007-06-18

    High temperature cleaning of producer gas from biomass gasification has been investigated with a granular filter. Field tests were performed for several hours on a single filter element at about 550 degrees C. The results show cake filtration on the granular material and indicate good filtration of the biomass gasification producer gas. The relatively low pressure drop over the filter during filtration is comparable to those of bag filters. The granular filter can operate with high filtration velocities compared to bag filters and maintain high efficiency and a low residual pressure. This work is a part of the BioSOFC-up project that has a goal of utilizing the producer gas from the gasification plant in a solid oxide fuel cell (SOFC). The BioSOFC-up project will continue to the end of 2007.

  15. RIVERBANK FILTRATION: EFFECT OF GROUND PASSAGE ON NOM CHARACTER

    EPA Science Inventory

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

  16. 21 CFR 177.2910 - Ultra-filtration membranes.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... up to 12 percent yttrium oxide (CAS Reg. No. 1314-36-9). (3) Ultra-filtration membranes that consist... up to 5 percent yttrium oxide (CAS Reg. No. 1314-36-9). (4) Ultrafiltration membranes that consist...

  17. 21 CFR 177.2910 - Ultra-filtration membranes.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... up to 12 percent yttrium oxide (CAS Reg. No. 1314-36-9). (3) Ultra-filtration membranes that consist... up to 5 percent yttrium oxide (CAS Reg. No. 1314-36-9). (4) Ultrafiltration membranes that consist...

  18. 21 CFR 177.2910 - Ultra-filtration membranes.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... up to 12 percent yttrium oxide (CAS Reg. No. 1314-36-9). (3) Ultra-filtration membranes that consist... up to 5 percent yttrium oxide (CAS Reg. No. 1314-36-9). (4) Ultrafiltration membranes that consist...

  19. A CONTINUED INVESTIGATION OF ELECTRICALLY STIMULATED FABRIC FILTRATION

    EPA Science Inventory

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

  20. Kinetic modelling of pressure filtration of ceramic powder suspensions

    SciTech Connect

    Correia, L.A.; Salomoni, A.; Hey, A.W.

    1995-09-01

    A kinetic model developed for radial pressure filtration is described and used to study the casting behaviour of an Alumina (Al6SG) and a Zirconia (TZ3Ys) slip stabilized with Dolapix CE64. For the Zirconia slip no influence of pressure and curvature is found. The casting behaviour of the Alumina slip seems to be influenced by both the pressure and the curvature of the filtrating surface.

  1. Aerosol filtration efficiency of in-duct air cleaners

    SciTech Connect

    Hanley, J.T.; Ensor, D.S.; Sparks, L.E.

    1998-09-01

    The paper discusses the evaluation of the fractional efficiency of several common ventilation air cleaners. The air cleaners included fiberglass furnace filters, paper-media filters, and electrostatically charged fiber cleaners. Results showed that filtration efficiency is highly particle size dependent over a 0.01-10 micrometer size range. Filtration efficiency was also seen to be dependent upon flow rate and the dust load condition of the air cleaner.

  2. Water Clarity Simulant for K East Basin Filtration Testing

    SciTech Connect

    Schmidt, Andrew J.

    2006-01-20

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

  3. The Maryland Centrifugal Experiment (MCX): Centrifugal Confinement and Velocity Shear Stabilization of Plasmas in Shaped Open Magnetic Systems

    SciTech Connect

    Hassam, Adil; Ellis, Richard F.

    2012-01-01

    The Maryland Centrifugal Experiment (MCX) Project has investigated the concepts of centrifugal plasma confinement and stabilization of instabilities by velocity shear. The basic requirement is supersonic plasma rotation about a shaped, open magnetic field. Overall, the MCX Project attained three primary goals that were set out at the start of the project. First, supersonic rotation at Mach number upto 2.5 was obtained. Second, turbulence from flute interchange modes was found considerably reduced from conventional. Third, plasma pressure was contained along the field, as evidenced by density drops of x10 from the center to the mirror throats.

  4. Integrated use of ultra scale-down and financial modeling to identify optimal conditions for the precipitation and centrifugal recovery of milk proteins.

    PubMed

    Chhatre, Sunil; Pampel, Lars; Titchener-Hooker, Nigel J

    2011-07-01

    This article investigates the integrated application of ultra scale-down (USD) techniques and economic modeling as a means for identifying optimal bioprocess operating conditions. The benefits of the approach are illustrated for the recovery of lactoperoxidase (LPO) from bovine milk. In the process, milk is skimmed to deplete its lipid content, before being subjected to low pH incubation with acetic acid in order to precipitate the primary impurity (casein). Following removal of the solids by disk stack centrifugation, pH adjustment and filtration, cation exchange chromatography is used as a positive mode column step to bind the LPO before it is polished and freeze dried. An economic model of this process was used to identify where greatest product loss occurs and hence where the largest opportunity cost was being incurred. Scale-down analysis was used to characterize the influence of the critical steps, identified as precipitation and centrifugation, upon LPO recovery. A mathematical model was used to relate the centrifuge feed flowrate and discharge interval to the supernatant yield, and it was shown that increasing the centrifugal solids residence time achieved superior solids de-watering and so higher product yield, although this also increased the overall processing time. To resolve this conflict, scale-down data were used again in conjunction with an economic model to determine the most suitable conditions that maximized annual profit and minimized operating costs. The results demonstrate the power of combining USD data with models of economic and process performance in order to establish the best overall operating strategies for biopharmaceutical manufacture.

  5. Characterization and modification of particulate properties to enhance filtration performance

    SciTech Connect

    Snyder, T.R.; Vann Bush, P.; Robinson, M.S.

    1990-06-01

    The specific objectives of this project are to characterize the particulate properties that determine the filtration performance of fabric filters, and to investigate methods for modifying these particulate properties to enhance filtration performance. Inherent in these objectives is the development of an experimental approach that will lead to full-scale implementation of beneficial conditioning processes identified during the project. The general approach has included a large number of laboratory evaluations to be followed by optional field tests of a new successful conditioning processes performed on a sidestream device. This project was divided into five tasks. The schedule followed for these tasks is shown in Figure 4. Tasks 2 and 3 each focus on one of the two complementary parts of the project. Task 2 Parametric Tests of Ashes and Fabrics, evaluates the degree to which ash properties and fabric design determine filtration performance. Task 3 Survey of Methods to Modify the Particle Filtration Properties, provides a literature review and laboratory study of techniques to modify ash properties. The results of these two tasks were used in Task 4 Proof-of-Concept Tests of Methods to Modify Particle Filtration Properties to demonstrate the effects on filtration performance of modifying ash properties. The findings of all the tasks are summarized in this Final Report. 13 refs.

  6. Viability of Heterodera glycines Exposed to Fungal Filtrates

    PubMed Central

    Chen, S. Y.; Dickson, D. W.; Mitchell, D. J.

    2000-01-01

    Filtrates from nematode-parasitic fungi have been reported to be toxic to plant-parasitic nematodes. Our objective was to determine the effects of fungal filtrates on second-stage juveniles and eggs of Heterodera glycines. Eleven fungal species that were isolated from cysts extracted from a soybean field in Florida were tested on J2, and five species were tested on eggs in vitro. Each fungal species was grown in Czapek-Dox broth and malt extract broth. No toxic activity was observed for fungi grown in Czapek-Dox broth. Filtrates from Paecilomyces lilacinus, Stagonospora heteroderae, Neocosmospora vasinfecta, and Fusarium solani grown in malt extract broth were toxic to J2, whereas filtrates from Exophiala pisciphila, Fusarium oxysporum, Gliocladium catenulatum, Pyrenochaeta terrestris, Verticillium chlamydosporium, and sterile fungi 1 and 2 were not toxic to J2. Filtrates of P. lilacinus, S. heteroderae, and N. vasinfecta grown in malt extract broth reduced egg viability, whereas F. oxysporum and P. terrestris filtrates had no effect on egg viability. PMID:19270965

  7. Wind Turbine Gearbox Oil Filtration and Condition Monitoring

    SciTech Connect

    Sheng, Shuangwen

    2015-10-25

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

  8. Effects of centrifugation stress on pituitary-gonadal function in male rats

    NASA Technical Reports Server (NTRS)

    Gray, G. D.; Smith, E. R.; Damassa, D. A.; Davidson, J. M.

    1980-01-01

    The effects of centrifugation for various lengths of time on circulating levels of luteinizing hormone (LH) and testosterone in male rats were investigated. In a chronic 52-day experiment, centrifugation at 4.1 G significantly reduced LH and testosterone levels for the entire period. Centrifugation at 2.3 G had less effect inasmuch as LH levels were not significantly decreased and testosterone levels were significantly reduced only during the first few days of centrifugation. In more acute experiments, centrifugation at 4.1 G for 4 h resulted in reduced testosterone levels, whereas centrifugation for 15 min did not significantly alter the hormone levels. These results indicate that centrifugation can decrease circulating LH and testosterone levels if the gravitational force is of sufficient magnitude and is maintained for a period of hours. Chronic centrifugation may also inhibit the acute excitatory response of LH to handling and ether stress.

  9. Geotechnical Centrifuge Experiments to Evaluate Piping in Foundation Soils

    DTIC Science & Technology

    2014-05-01

    Catalogue of scaling laws and similitude questions in geotechnical centrifuge modeling. IJPMG International Journal of Physical Modeling in...Technology. Sellmeijer, J. B., and M. A. Koenders. 1991. A mathematical model for piping. Applied Mathematical Modeling 15(11-12):646–651. van Beek, V

  10. Design of a piezoelectric shaker for centrifuge testing

    NASA Technical Reports Server (NTRS)

    Canclini, J. G.; Henderson, J. M.

    1979-01-01

    The design of a prototype piezoelectric shaker and its development to date is described. Although certain design problems remain to be solved, the piezoelectric system shows promise for adaptation to a larger payload system, such as the proposed geotechnical centrifuge at the Ames Research Center.

  11. Fluid forces on rotating centrifugal impeller with whirling motion

    NASA Technical Reports Server (NTRS)

    Shoji, H.; Ohashi, H.

    1980-01-01

    Fluid forces on a centrifugal impeller, whose rotating axis whirls with a constant speed, were calculated by using unsteady potential theory. Calculations were performed for various values of whirl speed, number of impeller blades and angle of blades. Specific examples as well as significant results are given.

  12. Quasi-steady centrifuge method for unsaturated hydraulic properties

    USGS Publications Warehouse

    Caputo, M.C.; Nimmo, J.R.

    2005-01-01

    [1] We have developed the quasi-steady centrifuge (QSC) method as a variation of the steady state centrifuge method that can be implemented simply and inexpensively with greater versatility in terms of sample size and other features. It achieves these advantages by somewhat relaxing the criterion for steadiness of flow through the sample. This compromise entails an increase in measurement uncertainty but to a degree that is tolerable in most applications. We have tested this new approach with an easily constructed apparatus to establish a quasi-steady flow of water in unsaturated porous rock samples spinning in a centrifuge, obtaining measurements of unsaturated hydraulic conductivity and water retention that agree with results of other methods. The QSC method is adaptable to essentially any centrifuge suitable for hydrogeologic applications, over a wide range of sizes and operating speeds. The simplified apparatus and greater adaptability of this method expands the potential for exploring situations that are common in nature but have been the subject of few laboratory investigations. Copyright 2005 by the American Geophysical Union.

  13. Prediction of performance of centrifugal pumps during starts under pressure

    NASA Technical Reports Server (NTRS)

    Rostafinski, W.

    1969-01-01

    Method which calculates start-up characteristics of centrifugal pumps reveals a capacity to predict pressure drop characteristics of pumps with vaned diffusers. Calculations are based on pump geometry, design-point flow, speed, and pressure rise, and the pump characteristic within range of approximately ten percent of the design-point flow.

  14. Latex micro-balloon pumping in centrifugal microfluidic platforms.

    PubMed

    Aeinehvand, Mohammad Mahdi; Ibrahim, Fatimah; Harun, Sulaiman Wadi; Al-Faqheri, Wisam; Thio, Tzer Hwai Gilbert; Kazemzadeh, Amin; Madou, Marc

    2014-03-07

    Centrifugal microfluidic platforms have emerged as point-of-care diagnostic tools. However, the unidirectional nature of the centrifugal force limits the available space for multi-step processes on a single microfluidic disc. To overcome this limitation, a passive pneumatic pumping method actuated at high rotational speeds has been previously proposed to pump liquid against the centrifugal force. In this paper, a novel micro-balloon pumping method that relies on elastic energy stored in a latex membrane is introduced. It operates at low rotational speeds and pumps a larger volume of liquid towards the centre of the disc. Two different micro-balloon pumping mechanisms have been designed to study the pump performance at a range of rotational frequencies from 0 to 1500 rpm. The behaviour of the micro-balloon pump on the centrifugal microfluidic platforms has been theoretically analysed and compared with the experimental data. The experimental data show that the developed pumping method dramatically decreases the required rotational speed to pump liquid compared to the previously developed pneumatic pumping methods. It also shows that within a range of rotational speed, a desirable volume of liquid can be stored and pumped by adjusting the size of the micro-balloon.

  15. Measurements of the rotordynamic shroud forces for centrifugal pumps

    NASA Technical Reports Server (NTRS)

    Guinzburg, A.; Brennen, C. E.; Acosta, A. J.; Caughey, T. K.

    1990-01-01

    An experiment was designed to measure the rotordynamic shroud forces on a centrifugal pump impeller. The measurements were done for various whirl/impeller speed ratios and for different flow rates. A destabilizing tangential force was measured for small positive whirl ratios and this force decreased with increasing flow rate.

  16. Pasteurization of grapefruit juice using a centrifugal ultraviolet light irradiator

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The pharmaceutical industry uses UV irradiators to inactivate viruses in liquids without heat. The penetration depth of UV in some liquids, such as serum plasma, can be short. To overcome this, very thin films may be produced by centrifugal force, small diameter tubing, or other means. Many liquid f...

  17. Liquid egg white pasteurization using a centrifugal UV irradiator

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Studies are lacking on UV nonthermal pasteurization of liquid egg white (LEW). The objective of this study was to inactivate Escherichia coli using a UV irradiator that centrifugally formed a thin film of LEW on the inside of a rotating cylinder. The LEW was inoculated with E. coli K12 to approximat...

  18. DEMONSTRATION BULLETIN: THE PLASMA CENTRIFUGAL FURNACE RETECH, INC.

    EPA Science Inventory

    The plasma centrifugal furnace is a thermal technology which uses the heat generated from a plasma torch to decontaminate metal and organic contaminated waste. This is accomplished by melting metal-bearing solids and, in the process, thermally destroying organic contaminants. The...

  19. Numerical Simulation and Cold Modeling experiments on Centrifugal Casting

    NASA Astrophysics Data System (ADS)

    Keerthiprasad, Kestur Sadashivaiah; Murali, Mysore Seetharam; Mukunda, Pudukottah Gopaliengar; Majumdar, Sekhar

    2011-02-01

    In a centrifugal casting process, the fluid flow eventually determines the quality and characteristics of the final product. It is difficult to study the fluid behavior here because of the opaque nature of melt and mold. In the current investigation, numerical simulations of the flow field and visualization experiments on cold models have been carried out for a centrifugal casting system using horizontal molds and fluids of different viscosities to study the effect of different process variables on the flow pattern. The effects of the thickness of the cylindrical fluid annulus formed inside the mold and the effects of fluid viscosity, diameter, and rotational speed of the mold on the hollow fluid cylinder formation process have been investigated. The numerical simulation results are compared with corresponding data obtained from the cold modeling experiments. The influence of rotational speed in a real-life centrifugal casting system has also been studied using an aluminum-silicon alloy. Cylinders of different thicknesses are cast at different rotational speeds, and the flow patterns observed visually in the actual castings are found to be similar to those recorded in the corresponding cold modeling experiments. Reasonable agreement is observed between the results of numerical simulation and the results of cold modeling experiments with different fluids. The visualization study on the hollow cylinders produced in an actual centrifugal casting process also confirm the conclusions arrived at from the cold modeling experiments and numerical simulation in a qualitative sense.

  20. Pasteurization of Grapefruit Juice using a Centrifugal Ultraviolet Light Device

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The pharmaceutical industry uses UV devices to nonthermally inactivate viruses in liquids. To overcome the low penetration depth of UV in some liquids, such as serum plasma, thin films are formed by centrifugal force. Liquid foods also have low UV penetration depths. Studies are lacking on nontherma...

  1. Application of antioxidants and centrifugation for cryopreservation of boar spermatozoa.

    PubMed

    Zhang, Wei; Yi, Kangle; Chen, Chao; Hou, Xiaofeng; Zhou, Xu

    2012-06-01

    Although cryopreserved boar semen has been available since 1975, a major breakthrough in commercial application has not yet occurred due to the high susceptibility of boar spermatozoa to damage during cryopreservation and the complicated process required for deep freezing. In recent years, the application of antioxidants during the cryopreservation of boar semen has been the subject of considerable research aimed at improving the quality of post-thaw semen. Centrifugation is necessary before using cryopreservation protocols for freezing boar spermatozoa. Studies of the effect of different centrifugation regimens on boar sperm recovery, yield and cryosurvival have made significant contributions. Therefore this review elucidates results of recent applications of various antioxidants and centrifugation regimens used in efforts to improve cryopreservation of boar spermatozoa. This review is intended to enhance understanding of the roles of these antioxidants and centrifugation regimens with respect to mechanisms that increase resistance to cryodamage of boar spermatozoa. In addition, the discussion addresses the need for developing an objective evaluation of effectiveness and estimating the prospect of application of new techniques for the cryopreservation of boar semen and its use in artificial insemination.

  2. Ocular torsion before and after 1 hour centrifugation.

    PubMed

    Groen, E; De Graaf, B; Bles, W; Bos, J E

    1996-01-01

    To assess a possible otolith contribution to effects observed following prolonged exposure to hypergravity, we used video oculography to measure ocular torsion during static and dynamic conditions of lateral body tilt (roll) before and after 1 h of centrifugation with a Gx-load of 3 G. Static tilt (from 0 to 57 degrees to either side) showed a 10% decrease in otolith-induced ocular torsion after centrifugation. This implies a reduced gain of the otolith function. The dynamic condition consisted of sinusoidal body roll (frequency 0.25 Hz, amplitude 45 degrees) about an earth horizontal and about an earth vertical axis (respectively, "with" and "without" otolith stimulation). Before centrifugation the gain of the slow component velocity (SCV) was significantly lower "with" otolith stimulation than "without" otolith stimulation. Apparently, the contribution of the otoliths counteracts the ocular torsion response generated by the semicircular canals. Therefore, the observed increase in SCV gain in the condition "with" otolith stimulation after centrifugation, seems in correspondence with the decreased otolith gain in the static condition.

  3. Demonstration of Reduced Gas Pressure in a Centrifugal Field.

    ERIC Educational Resources Information Center

    Fischer, Fred; Wild, R. L.

    1979-01-01

    Describes a simple demonstration that shows the change in molecular density and the reduction in pressure of air in a centrifugal field. Uses two circular disks with the same radius and rotating with the same angular velocity, in loose mutual contact, around their symmetry axis. (GA)

  4. Effect of chronic centrifugation on body composition in the rat.

    NASA Technical Reports Server (NTRS)

    Pitts, G. C.; Bull, L. S.; Oyama, J.

    1972-01-01

    Two groups of adult female rats were chronically centrifuged for 60 days (2.76 G, 4.15 G, controls at 1.00 G). Live weights of centrifugal rats decreased about 20 g (6%) per Delta 1 G above control. This weight loss comprised reductions in both body fat and fat-free body weight (FFBW) as determined by body-composition studies on eight rats per group killed at the end of centrifugation. Of nine components constituting the FFBW, only skeletal muscle, liver, and heart changed significantly in weight. Chemical composition showed reductions (compared with controls) in the fat fraction of most components and increases in the water fraction of liver and gut. Identical measurements were made on the remaining eight rats per group killed 43 days after return to 1 G. Neither centrifuged group had reached the control body-weight level at this time. No statistically significant effect of previous G level was found in any of the body-composition parameters. The possible involvment of physiological regulation was considered.

  5. Rapid multiplug filtration cleanup with multiple-walled carbon nanotubes and gas chromatography-triple-quadruple mass spectrometry detection for 186 pesticide residues in tomato and tomato products.

    PubMed

    Zhao, Pengyue; Huang, Baoyong; Li, Yanjie; Han, Yongtao; Zou, Nan; Gu, Kejia; Li, Xuesheng; Pan, Canping

    2014-04-30

    This study reports the development and validation of a novel rapid cleanup method based on multiple-walled carbon nanotubes in a packed column filtration procedure for analysis of pesticide residues followed by gas chromatography-triple-quadruple tandem mass spectrometry detection. The cleanup method was carried out by applying the streamlined procedure on a multiplug filtration cleanup column with syringes. The sorbent used for removing the interferences in the matrices is multiple-walled carbon nanotubes mixed with anhydrous magnesium sulfate. The proposed cleanup method is convenient and time-saving as it does not require any solvent evaporation, vortex, or centrifugation procedures. It was validated on 186 pesticides and 3 tomato product matrices spiked at two concentration levels of 10 and 100 μg kg(-1). Satisfactory recoveries and relative standard deviations are shown for most pesticides using the multiplug filtration cleanup method in tomato product samples. The developed method was successfully applied to the determination of pesticide residues in market samples.

  6. Membrane filtration – Fluorescent antibody staining procedure for detecting and quantifying Renibacterium salmoninarum in coelomic fluid of Chinook Salmon (Oncorhynchus tshawytscha)

    USGS Publications Warehouse

    Elliott, D.G.; Barila, T.Y.

    1987-01-01

    We developed a rapid method for detecting and quantifying the pathogen Renibacterium salmoninarum in coelomic fluid of spring chinook salmon (Oncorhynchus tshawytscha) by concentrating the bacteria on 0.2-μm polycarbonate filters and staining them with specific fluorescein-labeled antibody. Centrifugation of samples and resuspension of the sedimented material in phosphate-buffered saline containing Triton X-100 increased the ease of filtration. Background fluorescence was reduced by counterstaining filters with Eriochrome black T. Postfiltration staining, rinsing, and counterstaining were done in the syringe-mounted filter holders, reducing handling of the filters and possible loss of bacteria. The number of bacteria detected by the filtration – fluorescent antibody technique in a broth culture of R. salmoninarum ranged from 6.7 × 107to7.6 × 107/mL and was slightly higher than that determined by plate count (9.6 × 106/mL). Increasing the sample dilution or decreasing the number of microscope fields examined generally increased the variability of filter counts of R. salmoninarum. Using the filtration – fluorescent antibody technique, we detected the bacterium in the coelomic fluid of 85% of spawning female spring chinook salmon sampled from a hatchery population.

  7. Return to Flying Duties Following Centrifuge or Vibration Exposures

    NASA Technical Reports Server (NTRS)

    Scheuring, Richard A.; Clarke, Jonathan; Jones, Jeffrey A.

    2009-01-01

    Introduction: In an effort to determine the human performance limits for vibration in spacecraft being developed by NASA, astronauts were evaluated during a simulated launch profile in a centrifuge/vibration environment and separate vibration-only simulation. Current USAF and Army standards for return to flight following centrifuge exposures require 12-24 hours to pass before a crewmember may return to flying duties. There are no standards on vibration exposures and return to flying duties. Based on direct observation and provocative neurological testing of the astronauts, a new standard for return to flying duties following centrifuge and/or vibration exposures was established. Methods: 13 astronaut participants were exposed to simulated launch profiles in a + 3.5 Gx bias centrifuge/vibration environment and separately on a vibration table at the NASA-Ames Research Center. Each subject had complete neurological evaluations pre- and post-exposure for the centrifuge/vibration runs with the NASA neurological function rating scale (NFRS). Subjects who participated in the vibration-only exposures had video oculography performed with provocative maneuvers in addition to the NFRS. NFRS evaluations occurred immediately following each exposure and at 1 hour post-run. Astronauts who remained symptomatic at 1 hour had repeat NFRS performed at 1 hour intervals until the crewmember was asymptomatic. Results: Astronauts in the centrifuge/vibration study averaged a 3-5 point increase in NFRS scores immediately following exposure but returned to baseline 3 hours post-run. Subjects exposed to the vibration-only simulation had a 1-3 point increase following exposure and returned to baseline within 1-2 hours. Pre- and post- vibration exposure video oculography did not reveal any persistent ocular findings with provocative testing 1 hour post-exposure. Discussion: Based on direct observations and objective measurement of neurological function in astronauts following simulated launch

  8. Diverse Representations of Olfactory Information in Centrifugal Feedback Projections

    PubMed Central

    Osakada, Fumitaka; Tarabrina, Anna; Kizer, Erin; Callaway, Edward M.; Gage, Fred H.; Sejnowski, Terrence J.

    2016-01-01

    Although feedback or centrifugal projections from higher processing centers of the brain to peripheral regions have long been known to play essential functional roles, the anatomical organization of these connections remains largely unknown. Using a virus-based retrograde labeling strategy and 3D whole-brain reconstruction methods, we mapped the spatial organization of centrifugal projections from two olfactory cortical areas, the anterior olfactory nucleus (AON) and the piriform cortex, to the granule cell layer of the main olfactory bulb in the mouse. Both regions are major recipients of information from the bulb and are the largest sources of feedback to the bulb, collectively constituting circuits essential for olfactory coding and olfactory behavior. We found that, although ipsilateral inputs from the AON were uniformly distributed, feedback from the contralateral AON had a strong ventral bias. In addition, we observed that centrifugally projecting neurons were spatially clustered in the piriform cortex, in contrast to the distributed feedforward axonal inputs that these cells receive from the principal neurons of the bulb. Therefore, information carried from the bulb to higher processing structures by anatomically stereotypic projections is likely relayed back to the bulb by organizationally distinct feedback projections that may reflect different coding strategies and therefore different functional roles. SIGNIFICANCE STATEMENT Principles of anatomical organization, sometimes instantiated as “maps” in the mammalian brain, have provided key insights into the structure and function of circuits in sensory systems. Generally, these characterizations focus on projections from early sensory processing areas to higher processing structures despite considerable evidence that feedback or centrifugal projections often constitute major conduits of information flow. Our results identify structure in the organization of centrifugal feedback projections to the

  9. 21 CFR 864.9285 - Automated cell-washing centrifuge for immuno-hematology.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Automated cell-washing centrifuge for immuno... Establishments That Manufacture Blood and Blood Products § 864.9285 Automated cell-washing centrifuge for immuno-hematology. (a) Identification. An automated cell-washing centrifuge for immuno-hematology is a device...

  10. 21 CFR 864.9285 - Automated cell-washing centrifuge for immuno-hematology.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Automated cell-washing centrifuge for immuno... Establishments That Manufacture Blood and Blood Products § 864.9285 Automated cell-washing centrifuge for immuno-hematology. (a) Identification. An automated cell-washing centrifuge for immuno-hematology is a device...

  11. 21 CFR 864.9285 - Automated cell-washing centrifuge for immuno-hematology.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Automated cell-washing centrifuge for immuno... Establishments That Manufacture Blood and Blood Products § 864.9285 Automated cell-washing centrifuge for immuno-hematology. (a) Identification. An automated cell-washing centrifuge for immuno-hematology is a device...

  12. 77 FR 65360 - Grant of Authority for Subzone Status (Centrifugal and Submersible Pumps); Auburn, NY

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-10-26

    ... Foreign-Trade Zones Board Grant of Authority for Subzone Status (Centrifugal and Submersible Pumps... subzone at the centrifugal and submersible pump manufacturing and warehousing facilities of Xylem Water... activity related to the manufacturing of centrifugal and submersible pumps and related controllers at...

  13. Cycle-powered short radius (1.9M) centrifuge: exercise vs. passive acceleration

    NASA Technical Reports Server (NTRS)

    Greenleaf, J. E.; Gundo, D. P.; Watenpaugh, D. E.; Mulenburg, G. M.; Marchman, N.; Looft-Wilson, R.; Hargens, A. R.

    1996-01-01

    A human-powered short-arm centrifuge is described. This centrifuge could be used during spaceflight to provide +Gz acceleration while subjects performed exercise, thus supplying two forms of weightlessness countermeasures. Results from a study of cardiovascular responses while using the centrifuge are presented.

  14. 21 CFR 864.9275 - Blood bank centrifuge for in vitro diagnostic use.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Blood bank centrifuge for in vitro diagnostic use... Manufacture Blood and Blood Products § 864.9275 Blood bank centrifuge for in vitro diagnostic use. (a) Identification. A blood bank centrifuge for in vitro diagnostic use is a device used only to separate blood...

  15. 21 CFR 864.9275 - Blood bank centrifuge for in vitro diagnostic use.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Blood bank centrifuge for in vitro diagnostic use... Manufacture Blood and Blood Products § 864.9275 Blood bank centrifuge for in vitro diagnostic use. (a) Identification. A blood bank centrifuge for in vitro diagnostic use is a device used only to separate blood...

  16. 21 CFR 864.9275 - Blood bank centrifuge for in vitro diagnostic use.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Blood bank centrifuge for in vitro diagnostic use... Manufacture Blood and Blood Products § 864.9275 Blood bank centrifuge for in vitro diagnostic use. (a) Identification. A blood bank centrifuge for in vitro diagnostic use is a device used only to separate blood...

  17. 21 CFR 864.9275 - Blood bank centrifuge for in vitro diagnostic use.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Blood bank centrifuge for in vitro diagnostic use... Manufacture Blood and Blood Products § 864.9275 Blood bank centrifuge for in vitro diagnostic use. (a) Identification. A blood bank centrifuge for in vitro diagnostic use is a device used only to separate blood...

  18. 21 CFR 864.9275 - Blood bank centrifuge for in vitro diagnostic use.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Blood bank centrifuge for in vitro diagnostic use... Manufacture Blood and Blood Products § 864.9275 Blood bank centrifuge for in vitro diagnostic use. (a) Identification. A blood bank centrifuge for in vitro diagnostic use is a device used only to separate blood...

  19. 40 CFR Appendix - Alternative Organic HAP Emissions Limits for Open Molding, Centrifugal Casting, and SMC...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... Limits for Open Molding, Centrifugal Casting, and SMC Manufacturing Operations Where the Standards Are..., Table 5 Alternative Organic HAP Emissions Limits for Open Molding, Centrifugal Casting, and SMC... casting—CR/HS 3,4 A vent system that moves heated air through the mold 27 lb/ton. 8. Centrifugal...

  20. 40 CFR Appendix - Alternative Organic HAP Emissions Limits for Open Molding, Centrifugal Casting, and SMC...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... Limits for Open Molding, Centrifugal Casting, and SMC Manufacturing Operations Where the Standards Are..., Table 5 Alternative Organic HAP Emissions Limits for Open Molding, Centrifugal Casting, and SMC... casting—CR/HS 3,4 A vent system that moves heated air through the mold 27 lb/ton. 8. Centrifugal...