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Sample records for vial centrifugation cultures

  1. RAPID DETECTION OF RESPIRATORY VIRUSES USING MIXTURES OF MONOCLONAL-ANTIBODIES ON SHELL VIAL CULTURES

    NARCIS (Netherlands)

    SCHIRM, J; LUIJT, DS; PASTOOR, GW; MANDEMA, JM; SCHRODER, FP

    1992-01-01

    Eleven hundred and thirty-three clinical specimens submitted to the laboratory for diagnosis of respiratory virus infections were tested by direct immunofluorescence (DIF) for respiratory syncytial virus (RSV), by shell vial culture, and by conventional cell culture. The shell vial cultures were

  2. Application of modified shell vial culture procedure for arbovirus detection.

    Directory of Open Access Journals (Sweden)

    Edna R Caceda

    Full Text Available The isolation of arboviruses from patient's low titer sera can be difficult. Here we compared the detection efficiency of Dengue (DEN, Yellow Fever (YF, Saint Louis Encephalitis (SLE, West Nile (WN, Ilheus (ILH, Group C (GC, Oropouche (ORO, Mayaro (MAY and Venezuela Encephalitis Equine (VEE viruses using a Modified Shell Vial Culture (MSVC protocol to a Standard Cell Culture (SCC protocol. First the MSVC and SCC protocols were compared using five dilutions for each of the following stock viruses: DEN-1, DEN-2, DEN-3, DEN-4, YF, SLE, WN, ILH, GC, ORO, MAY and VEE. Next, patients' original sera from which viruses (DEN-1, DEN-2, DEN-3, YF, GC, ORO, MAY and VEE had been previously isolated were compare by the two methods using five sera dilutions. In addition, seven sera that were positive for DEN-3 by RT-PCR and negative by SCC were processed by MSVC. The MSVC protocol was consistently 1-2 logs higher virus dilution more sensitive for virus detection than the SCC protocol for all stock Flaviviruses tested (DEN-1, DEN-2, DEN-3, DEN-4, YF, SLE, WN and ILH. MSVC was equal to or one log more sensitive for virus detection than SCC for the stock Bunyaviruses (GC and ORO. For the stock Alphavirus MAY, MSVC was equally or one log more sensitive for virus detection than SCC, while for VEE SCC was equally or one log more sensitive for virus detection than MSVC. MSVC was consistently one to two sera dilutions more sensitive than SCC for the detection of Flaviviruses from patients' sera. Both methods were approximately equally sensitive for the detection of Bunyaviruses from patients' sera and equal or one dilution less sensitive for the detection of Alphaviruses from patients' sera. Additionally, MSVC detected DEN virus in five of seven DEN-3 RT-PCR positive, SCC negative patients' sera.

  3. Enhanced infectivity of bluetongue virus in cell culture by centrifugation.

    OpenAIRE

    Sundin, D R; Mecham, J.O.

    1989-01-01

    The effects of centrifugation of the infection of cell culture with bluetongue virus (BTV) were investigated. Baby hamster kidney cells were infected with BTV with or without centrifugation. Viral antigen was detected by immunofluorescence at 24 h in both centrifuged and noncentrifuged cultures. However, after 24 h of infection, the production of PFU in centrifuged cell cultures was 10- to 20-fold greater than that seen in cultures not centrifuged. In addition, centrifugation enhanced the dir...

  4. MALDI-TOF MS based carbapenemase detection from culture isolates and from positive blood culture vials.

    Science.gov (United States)

    Ghebremedhin, B; Halstenbach, A; Smiljanic, M; Kaase, M; Ahmad-Nejad, P

    2016-02-02

    Antibiotic resistance in bacteria leads to massive health problems. Incidence of carbapenem and multidrug resistance in Gram-negative bacteria are increasing globally and turn out to be a very urgent challenge in health care. Resistant bacteria play an important clinical role during hospital outbreaks as well as in sepsis. Rapid diagnostic tests are necessary to provide immediate information for antimicrobial treatment and infection control measures. Our mass spectrometry-based assay was validated with 63 carbapenemase-producing Gram-negative bacterial isolates, and 35 carbapenem-resistant Gram-negative species with no carbapenemase production. These were analyzed from solid culture media and positive blood culture vials. After 4 h of incubation the carbapenemase products were analyzed with the MALDI-TOF MS. All the isolates were genotyped for carbapenemase genes by PCR and sequencing. For culture isolates the concordance of hydrolysis assay to genetic results was 98 % for OXA variants, KPC, VIM, IMP, GIM, and NDM. In contrast, only 14 of 29 Acinetobacter baumannii isolates carrying the OXA and NDM genes could be identified from blood culture. However, from blood culture vials our method allowed the detection of carbapenemases in 98 % of Pseudomonas and Enterobacteriaceae isolates harboring different genes. This MALDI-TOF MS-based assay permitted the detection of carbapenemases either from solid culture media (98-100 %) or blood culture vials (96 %) for all non-A. baumannii isolates within 4 h. In case of A. baumannii isolates the assay was highly sensitive for the detection of carbapenemases directly from solid culture media.

  5. Enhanced infectivity of bluetongue virus in cell culture by centrifugation.

    Science.gov (United States)

    Sundin, D R; Mecham, J O

    1989-07-01

    The effects of centrifugation of the infection of cell culture with bluetongue virus (BTV) were investigated. Baby hamster kidney cells were infected with BTV with or without centrifugation. Viral antigen was detected by immunofluorescence at 24 h in both centrifuged and noncentrifuged cultures. However, after 24 h of infection, the production of PFU in centrifuged cell cultures was 10- to 20-fold greater than that seen in cultures not centrifuged. In addition, centrifugation enhanced the direct detection of PFU from blood samples collected from a sheep experimentally infected with BTV.

  6. Combined use of sonication and monoclonal antibodies for the detection of early and late cytomegalovirus antigens in centrifugation cultures.

    Science.gov (United States)

    Agha, S A; Coleman, J C; Selwyn, S; Mahmoud, L A; Abd-Elaal, A M

    1988-10-01

    A total of 157 clinical specimens was inoculated into shell vials and conventional tube cell cultures containing confluent monolayers of human embryonic lung fibroblasts (HELF). Of 31 clinical cytomegalovirus (CMV) isolates, 30 specimens (96.8%) were positive by the immunofluorescence method on centrifugation vial cultures (CVC-IF), whereas the cytopathic effects (CPE) of CMV were detected in only 14 specimens (45.2%) in conventional tube cell cultures (CCC), P less than 0.001 and in 22 specimens (70.9%) in centrifugation vial cultures (CVC-P), P less than 0.1. Significantly more fluorescent foci were detected in centrifugation cultures inoculated with sonicated urine samples (P less than 0.001). CVC-P is more sensitive than CCC for the diagnosis of CMV (P less than 0.05), and a highly significant difference was observed when we compared the mean day to initial detection of CPE (P less than 0.001). For optimal detection of CMV, both CVC-IF and CVC-P should be used for the laboratory diagnosis of this virus infection.

  7. Rapid detection of respiratory viruses by shell vial culture and direct staining by using pooled and individual monoclonal antibodies.

    Science.gov (United States)

    Matthey, S; Nicholson, D; Ruhs, S; Alden, B; Knock, M; Schultz, K; Schmuecker, A

    1992-03-01

    The Bartels respiratory virus panel detection kit is an indirect fluorescent-antibody (IFA) method that uses pooled and individual antisera for tissue culture confirmation of seven respiratory viruses. We evaluated these reagents for detecting viral antigen in shell vial cultures and by direct staining of cells from respiratory specimens. The isolation from 254 specimens of respiratory viruses in shell vial cultures compared with standard tube cultures was highly sensitive (94%) and specific (97.3%). The numbers of viral isolates detected in three consecutive years of testing with shell vial cultures were 68 of 254 (26.8%), 101 of 381 (26.5%), and 122 of 430 (28.4%). IFA direct staining of all 1,065 specimens resulted in 183 (17.2) being uninterpretable because of inadequate numbers of cells or interfering fluorescence. The sensitivity and specificity of the interpretable IFA direct stains in comparison with shell vial cultures were 85.9 and 87.1%, respectively. For detection of 881 adequate specimens, Bartels respiratory syncytial virus IFA direct staining compared with an Ortho Diagnostics Systems direct fluorescent-antibody test for respiratory syncytial virus RSV was highly sensitive (95.5%) and specific (97%). Shell vial cultures combined with Bartels IFA reagents are a rapid alternative to standard tube cultures. Bartels IFA direct staining with individual antisera provides useful same-day screening of respiratory specimens, but the antiserum pool was not effective in screening for positive specimens because of excessive amounts of nonspecific fluorescence.

  8. Modeling industrial centrifugation of mammalian cell culture using a capillary based scale-down system.

    Science.gov (United States)

    Westoby, Matthew; Rogers, Jameson K; Haverstock, Ryan; Romero, Jonathan; Pieracci, John

    2011-05-01

    Continuous-flow centrifugation is widely utilized as the primary clarification step in the recovery of biopharmaceuticals from cell culture. However, it is a challenging operation to develop and characterize due to the lack of easy to use, small-scale, systems that can be used to model industrial processes. As a result, pilot-scale continuous centrifugation is typically employed to model large-scale systems requiring a significant amount of resources. In an effort to reduce resource requirements and create a system which is easy to construct and utilize, a capillary shear device, capable of producing energy dissipation rates equivalent to those present in the feed zones of industrial disk stack centrifuges, was developed and evaluated. When coupled to a bench-top, batch centrifuge, the capillary device reduced centrate turbidity prediction error from 37% to 4% compared to using a bench-top centrifuge alone. Laboratory-scale parameters that are analogous to those routinely varied during industrial-scale continuous centrifugation were identified and evaluated for their utility in emulating disk stack centrifuge performance. The resulting relationships enable bench-scale process modeling of continuous disk stack centrifuges using an easily constructed, scalable, capillary shear device coupled to a typical bench-top centrifuge. Copyright © 2010 Wiley Periodicals, Inc.

  9. Evaluating the role of low-speed centrifugation towards transfecting human peripheral blood mononuclear cell culture

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    M Majumdar

    2014-01-01

    Full Text Available The conventional method of transfection of suspension cells by chemical has proven to be very difficult. We present a new transfection protocol, wherein, low-speed centrifugation of cell culture plates immediately after adding the lipid: DNA complex significantly enhances the transfection efficiency. Peripheral blood mononuclear cells (PBMCs were transfected with BLOCK-iT™ Fluorescent Oligo (scrambled siRNA and lipofectamine complex using conventional and low-speed centrifugation modified transfection protocols. The efficiency of transfection was determined using flowcytometer and cell viability was checked using MTT assay. Incorporation of low-speed centrifugation significantly enhances the transfection efficiency of BLOCK-iT™ in the suspension culture of PBMCs as compared to conventional transfection method (99.8% vs 28.3%; P < 0.0001, even at a low concentration of 40 picomoles without affecting the cell viability. Centrifugation enhanced transfection (CET technique is simple, time-saving and novel application without compromising the cell viability in the context of recently popular RNA interference in suspension cultures of PBMCs. This undemanding modification might be applicable to a wide variety of cell lines and solve crucial problem of researchers working with RNA interference in suspension cultures.

  10. Evaluation of commercial boric acid containing vials for urine culture: low risk of contamination and cost effectiveness considerations.

    Science.gov (United States)

    Appannanavar, Suma B; Biswal, Manisha; Rajkumari, Nonika; Mohan, Balvinder; Taneja, Neelam

    2013-01-01

    Urine culture is a gold standard in the diagnosis of urinary tract infection. Clean catch midstream urine collection and prompt transportation is essential for appropriate diagnosis. Improper collection and delay in transportation leads to diagnostic dilemma. In developing countries, higher ambient temperatures further complicate the scenario. Here, we have evaluated the role of boric acid as a preservative for urine samples prior to culture in female patients attending outpatient department at our center. Consecutive 104 urine samples were cultured simultaneously in plain uricol (Control-C) and boric acid containing tubes from Becton Dickinson urine culture kit (Boric acid group-BA). In the real-time evaluation, we found that in almost 57% (59/104) of the urine samples tested, it was more effective in maintaining the number of the organisms as compared to samples in the container without any preservative. Our in vitro study of simulated urine cultures revealed that urine samples could be kept up to 12 h before culture in the preservative without any inhibitory effect of boric acid. Though the use of boric acid kit may marginally increase the initial cost but has indirect effects like preventing delays in treatment and avoidance of false prescription of antibiotics. If the man-hours spent on repeat investigations are also taken into consideration, then the economic cost borne by the laboratory would also decrease manifold with the use of these containers.

  11. Environmental surveillance of enterovirus in Northern India using an integrated shell vial culture with a semi-nested RT PCR and partial sequencing of the VP1 gene.

    Science.gov (United States)

    Shukla, Deepti; Kumar, Arvind; Srivastava, Shalini; Idris, Mohammad Z; Dhole, Tapan N

    2013-03-01

    Enteroviruses have been reported in epidemic form during last 10 years in northern India. Environmental surveillance of sewage is the method of choice in limited resources countries for detection of enterovirus serotypes circulating in the community. Twenty-four sewage samples collected between January, 2009 and December, 2010 were tested for enterovirus by using a new modified integrated shell vial culture (ISVC) with a semi-nested RT-PCR of a partial VP1 gene and virus isolation integrated with semi-nested RT-PCR of a partial VP1 gene. Twenty-one (87.5%) out of 24 samples were positive for enterovirus by the conventional method and all samples (100%) by the ISVC-RT-PCR. The additional positive samples detected by ISVC-RT-PCR was typed as six different enterovirus serotypes (Sabin poliovirus 3, Coxsackievirus B3, Coxsackievirus A13, Coxsackievirus A17, Echovirus 33, and Enterovirus 75). Phylogenetic analysis of a partial VP1 gene of Echovirus 19 showed that one genetic lineage clustered with isolates from Georgia suggesting their importation into northern India. Detection of wild poliovirus in the absence of clinical cases with 16 different co-circulating enterovirus serotypes supports the need of increased molecular surveillance of sewage. Rapid identification and characterization of enterovirus serotypes is necessary to study their transmission and evolution in different geographical regions to prevent future outbreak. Copyright © 2013 Wiley Periodicals, Inc.

  12. Isolation of Peroxisomes from Rat Liver and Cultured Hepatoma Cells by Density Gradient Centrifugation.

    Science.gov (United States)

    Manner, Andreas; Islinger, Markus

    2017-01-01

    Subcellular fractionation is still a valuable technique to unravel organelle-specific proteomes, validate the location of uncharacterized proteins, or to functionally analyze import and metabolism in individual subcellular compartments. In this respect, density gradient centrifugation still represents a very classic, indispensable technique to isolate and analyze peroxisomes. Here, we present two independent protocols for the purification of peroxisomes from either liver tissue or the HepG2 hepatoma cell line. While the former permits the isolation of highly pure peroxisomes suitable for, e.g., subcellular proteomics experiments, the latter protocol yields peroxisomal fractions from considerably less purity but allows to easily modify metabolic conditions in the culture medium or to genetically manipulate the peroxisomal compartment. In this respect, both purification methods represent alternative tools to be applied in experiments investigating peroxisome physiology.

  13. Comparison of the Lysis Centrifugation Method with the Conventional Blood Culture Method in Cases of Sepsis in a Tertiary Care Hospital

    Directory of Open Access Journals (Sweden)

    Harshal R Parikh

    2012-01-01

    Conclusion: For the diagnosis of sepsis, combination of the lysis centrifugation method and the conventional blood culture method with trypticase soy broth or biphasic media is advocable, in order to achieve faster recovery and a better yield of microorganisms.

  14. Detection and serotyping of herpes simplex virus in MRC-5 cells by use of centrifugation and monoclonal antibodies 16 h postinoculation.

    Science.gov (United States)

    Gleaves, C A; Wilson, D J; Wold, A D; Smith, T F

    1985-01-01

    Monoclonal antibodies (Syva Co., Palo Alto, Calif.) were used for the detection and serotyping of herpes simplex virus (HSV) isolates by immunofluorescence 16 h after inoculation of MRC-5 monolayers in 3.7-ml shell vials and after low-speed centrifugation. A total of 119 specimens were inoculated into conventional tube cell cultures and shell vials. Of 98 specimens inoculated on the same day of receipt in the laboratory (fresh specimens), all 23 (23.5%) HSV-positive specimens were identified by serotype in 16 h in shell vials by immunofluorescence, whereas only 8 of 23 HSV-positive specimens (34.8%) produced cytopathic effects in conventional tube cell cultures in this time period. Similarly, of 21 original specimen extracts previously determined to be culture positive for HSV (stored specimens), all were detected and serotyped by the immunofluorescence test with monoclonal antibodies 16 h postinoculation compared with the recognition of only 8 of these isolates (38.1%) by cytopathic effect that soon. This technique of centrifugal inoculation of HSV in shell vials containing MRC-5 cells permitted detection of this virus in all positive specimens with serotype determination within 16 h postinoculation.

  15. Limited use of Centritech Lab II Centrifuge in perfusion culture of rCHO cells for the production of recombinant antibody.

    Science.gov (United States)

    Kim, Byoung Jin; Oh, Duk Jae; Chang, Ho Nam

    2008-01-01

    Perfusion cultures of recombinant Chinese hamster ovary cells, producing recombinant antibody against the S surface antigen of Hepatitis B virus, were carried out in continuous and intermittent mode using a Centritech Lab II Centrifuge. In the continuous perfusion process, despite the absence of shear stress from the pump head, long-term operation was not possible because of continuously repeated exposure to oxygen limitation and low temperature, as well as shear stress from centrifugal force. In the intermittent perfusion processes, the frequency of cell-passage through the centrifuge was substantially reduced, compared with the continuous perfusion mode; however, the degree of reduction could not guarantee stable long-term operation. Although various operating parameters were applied in the intermittent perfusion cultures, high cell densities could not be maintained stably. In a single bioreactor culture system, a specific cell that is returned from the centrifuge to the bioreactor could be transferred from the bioreactor to the centrifuge again in the next cycle. These repetitive damages, caused by shear stress from the pump head and centrifugal force, as well as exposure to suboptimal conditions such as oxygen limitation and low temperature below 37 degrees C, were more serious at higher perfusion rates. Subsequently, damaged cells and dead cells were continuously accumulated in the bioreactor. Culture temperature shift from 37 to 33 degrees C increased antibody concentrations but showed inhibitory effects on cell growth. The negative effects of lowering culture temperature on cell growth overwhelmed the positive effects on antibody production. To protect cells from shear stress, Pluronic F-68 was 2-fold concentrated in the culture medium; nevertheless, a significantly higher concentration of Pluronic F-68 (2 g/L) may have inhibitory effects on cell growth.

  16. Effect of dexamethasone on detection of herpes simplex virus in clinical specimens by conventional cell culture and rapid 24-well plate centrifugation.

    Science.gov (United States)

    Woods, G L; Mills, R D

    1988-06-01

    During a 4-month period, two methods for rapid detection of herpes simplex virus (HSV) were examined: (i) pretreatment of A549 cells with dexamethasone for conventional tissue culture (277 specimens) and (ii) 24-well plate centrifugation using A549 cells with and without dexamethasone pretreatment and staining with serotype-specific monoclonal antibodies (Syva Co., Palo Alto, Calif.) after incubation for 16 to 18 h (153 specimens). By conventional tube cell culture, both with and without dexamethasone, HSV was identified in 88 of 277 (32%) specimens. Significantly more specimens were positive for HSV at 24 h (46 versus 27 specimens) and at 48 h (a total of 72 versus 59 specimens) (P less than 0.0001) in dexamethasone-treated A549 cells. Of the 153 specimens tested by conventional culture and 24-well plate centrifugation, HSV was detected in 44 (29%) by conventional culture, and by 24-well plate centrifugation with and without dexamethasone, HSV was detected in 32 (21%) and 30 (20%) specimens, respectively. The sensitivity, specificity, and positive and negative predictive values of 24-well plate centrifugation with A549 cells for detection of HSV were 73 (71% without dexamethasone), 100, 100, and 90%, respectively. In conventional tube cell culture, pretreatment of A549 cells with dexamethasone results in more rapid detection of HSV. Centrifugal inoculation of dexamethasone-treated and untreated A549 cells in 24-well plates and staining with monoclonal antibodies after incubation for 16 to 18 h is an insensitive means to detect HSV in clinical specimens and should not replace conventional tube cell culture.

  17. Centrifugal pumps

    CERN Document Server

    Anderson, HH

    1981-01-01

    Centrifugal Pumps describes the whole range of the centrifugal pump (mixed flow and axial flow pumps are dealt with more briefly), with emphasis on the development of the boiler feed pump. Organized into 46 chapters, this book discusses the general hydrodynamic principles, performance, dimensions, type number, flow, and efficiency of centrifugal pumps. This text also explains the pumps performance; entry conditions and cavitation; speed and dimensions for a given duty; and losses. Some chapters further describe centrifugal pump mechanical design, installation, monitoring, and maintenance. The

  18. CENTRIFUGAL SEPARATORS

    Science.gov (United States)

    Skarstrom, C.

    1959-03-10

    A centrifugal separator is described for separating gaseous mixtures where the temperature gradients both longitudinally and radially of the centrifuge may be controlled effectively to produce a maximum separation of the process gases flowing through. Tbe invention provides for the balancing of increases and decreases in temperature in various zones of the centrifuge chamber as the result of compression and expansions respectively, of process gases and may be employed effectively both to neutralize harmful temperature gradients and to utilize beneficial temperaturc gradients within the centrifuge.

  19. Enhanced detection of infectious salmon anaemia virus using a low-speed centrifugation technique in three fish cell lines.

    Science.gov (United States)

    Molloy, S D; Thomas, E; Hoyt, K; Bouchard, D A

    2013-01-01

    Infectious salmon anaemia (ISA), caused by ISA virus (ISAV), is a serious disease of farmed Atlantic salmon, Salmo salar L. Recently, molecular- and immunofluorescent-based techniques have become powerful diagnostic tools for ISAV detection, but culture-based techniques remain the gold standard. A disadvantage of ISAV culture is that the incubation time required before cytopathic effect (CPE) is observed in cell monolayers. To decrease time until CPE is observed, a low-speed centrifugation technique was applied to existing standard operating procedures for ISAV culture in three fish cell lines. Time until CPE observation was compared in CHSE, SHK and ASK cells, treated or not treated with low-speed centrifugation after inoculation with ISAV. Low-speed centrifugation treatment significantly enhanced observable cell infection. Compared to control cells, the length of time until ISAV CPE observation decreased in centrifuged ASK and CHSE cells. Low-speed centrifugation was also incorporated into a modified clinical shell vial assay. At 48 h post-inoculation with approximately 20 viral particles, ISAV was detected by an immunofluorescence antibody test in treated ASK and SHK1 cells but not in control cells. Finally, this enhanced viral adsorption assay performed in ASK cells demonstrated higher sensitivity than a real-time RT-PCR assay performed on RNA isolated from ISAV-spiked salmon kidney homogenates. © 2012 Blackwell Publishing Ltd.

  20. Isolation of human monocytes by double gradient centrifugation and their differentiation to macrophages in teflon-coated cell culture bags.

    Science.gov (United States)

    Menck, Kerstin; Behme, Daniel; Pantke, Mathias; Reiling, Norbert; Binder, Claudia; Pukrop, Tobias; Klemm, Florian

    2014-09-09

    Human macrophages are involved in a plethora of pathologic processes ranging from infectious diseases to cancer. Thus they pose a valuable tool to understand the underlying mechanisms of these diseases. We therefore present a straightforward protocol for the isolation of human monocytes from buffy coats, followed by a differentiation procedure which results in high macrophage yields. The technique relies mostly on commonly available lab equipment and thus provides a cost and time effective way to obtain large quantities of human macrophages. Briefly, buffy coats from healthy blood donors are subjected to a double density gradient centrifugation to harvest monocytes from the peripheral blood. These monocytes are then cultured in fluorinated ethylene propylene (FEP) Teflon-coated cell culture bags in the presence of macrophage colony-stimulating factor (M-CSF). The differentiated macrophages can be easily harvested and used for subsequent studies and functional assays. Important methods for quality control and validation of the isolation and differentiation steps will be highlighted within the protocol. In summary, the protocol described here enables scientists to routinely and reproducibly isolate human macrophages without the need for cost intensive tools. Furthermore, disease models can be studied in a syngeneic human system circumventing the use of murine macrophages.

  1. Ultra scale-down approaches for clarification of mammalian cell culture broths in disc-stack centrifuges.

    Science.gov (United States)

    Zaman, Ferhana; Allan, Corey M; Ho, Sa V

    2009-01-01

    Ultra-scale down (USD) methodology developed by University College London for cell broth clarification with industrial centrifuges was applied to two common cell lines (NS0 and GS-CHO) expressing various therapeutic monoclonal antibodies. A number of centrifuges at various scales were used with shear devices operating either by high speed rotation or flow-through narrow channels. The USD methodology was found effective in accounting for both gravitational and shear effects on clarification performance with three continuous centrifuges at pilot and manufacturing scales. Different shear responses were observed with the two different cell lines and even with the same cell line expressing different products. Separate particle size analysis of the treated broths seems consistent with the shear results. Filterability of the centrifuged solutions was also evaluated to assess the utility of the USD approach for this part of the clarification operation. (c) 2009 American Institute of Chemical Engineers Biotechnol. Prog., 2009.

  2. Legislacion sobre seguridad vial en las Americas

    National Research Council Canada - National Science Library

    Hijar, Martha; Perez-Nunez, Ricardo; Inclan-Valadez, Cristina; Silveira-Rodrigues, Eugenia Maria

    2012-01-01

    La legislacion sobre cinco de los principales factores de riesgo de sufrir lesiones causadas por el transito, asi como el cumplimiento de la ley, son esenciales para forjar una cultura integral de seguridad vial...

  3. Drawing medicine out of a vial

    Science.gov (United States)

    ... page: //medlineplus.gov/ency/patientinstructions/000530.htm Drawing medicine out of a vial To use the sharing ... a clean area. Wash your hands. Check Your Medicine Carefully check your medicine: Check the label. Make ...

  4. Centrifugal partition extraction, a new method for direct metabolites recovery from culture broth: case study of torularhodin recovery from Rhodotorula rubra.

    Science.gov (United States)

    Ungureanu, Camelia; Marchal, Luc; Chirvase, Ana Aurelia; Foucault, Alain

    2013-03-01

    Centrifugal partition extraction (CPE), close to centrifugal partition chromatography, put in contact in a continuous way two immiscible liquid phases. This work presents early experiments on CPE use for solid-liquid-liquid extraction. It was applied to the direct treatment of culture broth for metabolites recovery. Torularhodin is one of the carotenoid pigments produced by the yeast Rhodotorula sp., with a terminal carboxylic group considered nowadays as a powerful antioxidant to be included in food and drugs formulations. Torularhodin was extracted from Rhodotorula rubra ICCF 209 cells by CPE. The recovery of torularhodin reaches 74 μg/g of biomass i.e. 294 μg/L of culture medium. The efficiency of the extraction step increased with the operating flow rate. The extraction yield could reach 91% with a contact time lower than 2 min. A 300 mL apparatus allowed a feed at 90 mL/min. The technique is proposed for extraction or sample preparation before analysis. Copyright © 2012 Elsevier Ltd. All rights reserved.

  5. Vial freeze-drying, part 1: new insights into heat transfer characteristics of tubing and molded vials.

    Science.gov (United States)

    Hibler, Susanne; Wagner, Christophe; Gieseler, Henning

    2012-03-01

    In order to optimize a freeze-drying cycle, information regarding the heat transfer characteristics of the container system is imperative. Two most recently developed tubing (TopLyo™) and molded (EasyLyo™) vial designs were compared with a standard serum tubing and molded vial, a polymer vial (TopPac™), and an amber molded EasyLyo™. In addition, the impact of methodology on the determination of reliable vial heat transfer coefficient (K(v) ) data is examined in detail. All K(v) s were gravimetrically determined by sublimation tests with pure water at 50, 100, 200, and 400 mTorr. In contrast to the traditional assumption that molded vials exhibit inefficient heat transfer characteristics, these vials showed a very similar performance compared with their serum tubing counterparts in the relevant pressure range for freeze-drying. At 100 mTorr, the TopLyo™ center vials show only 4% higher K(v) values than the EasyLyo™ center vials. All glass vials outmatch the polymer vial in terms of heat transfer, up to 30% elevated heat transfer for the TopLyo™ center vials at 400 mTorr. Sublimation tests have demonstrated to be a valuable tool to investigate the heat transfer characteristics of vials, but results are dependent on methodology. New developments in molded vial manufacturing lead to improved heat transfer performance. Copyright © 2011 Wiley Periodicals, Inc.

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

    Science.gov (United States)

    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. Copyright © 2015 Elsevier Inc. All rights reserved.

  7. Centrifugal pumps

    CERN Document Server

    Gülich, Johann Friedrich

    2014-01-01

    This book gives an unparalleled, up-to-date, in-depth treatment of all kinds of flow phenomena encountered in centrifugal pumps including the complex interactions of fluid flow with vibrations and wear of materials. The scope includes all aspects of hydraulic design, 3D-flow phenomena and partload operation, cavitation, numerical flow calculations, hydraulic forces, pressure pulsations, noise, pump vibrations (notably bearing housing vibration diagnostics and remedies), pipe vibrations, pump characteristics and pump operation, design of intake structures, the effects of highly viscous flows, pumping of gas-liquid mixtures, hydraulic transport of solids, fatigue damage to impellers or diffusers, material selection under the aspects of fatigue, corrosion, erosion-corrosion or hydro-abrasive wear, pump selection, and hydraulic quality criteria. As a novelty, the 3rd ed. brings a fully analytical design method for radial impellers, which eliminates the arbitrary choices inherent to former design procedures. The d...

  8. Three-dimensionally spiral structure of the water stream induced by a centrifugal stirrer in large aqua-cultural ponds

    Science.gov (United States)

    Itano, Tomoaki; Inagaki, Taishi; Nakamura, Choji; Sugihara-Seki, Masako; Hyodo, Jinsuke

    2017-11-01

    We have conducted measurements of the water stream produced by a mechanical stirrer (diameter 2.4[m], electric power 50[W]) located in shallow rectangular reservoirs (small 0.7[ha], large 3.7[ha]), which may be employed as a cost-efficient aerator for the aqua-cultural purpose, with the aid of both particle tracking velocimetry by passive tracers floating on the surface and direct measurement by electro-magnetic velocimeter under the surface. The present measurements indicate that the stirrer drives primarily the horizontally rotating water stream and secondarily the vertical convection between the surface and the bottom of the reservoir, which results in the three-dimensionally spiral-shaped water streams scaled vertically by just a meter but horizontally by more than ten meters. It is suggested that the spiral structure driven by the stirrer may activate the underwater vertical mixing and enhance dissolved oxygen at the bottom of aqua-cultural pond more effectively than the paddle-wheel aerators commonly used in aqua-cultural ponds. This research was financially supported in part by the Kansai University Fund for Supporting Young Scholars, 2016-2017.

  9. CENTRIFUGE END CAP

    Science.gov (United States)

    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.

  10. Centrifuge modeling of monopiles

    DEFF Research Database (Denmark)

    Klinkvort, Rasmus Tofte

    2010-01-01

    To gain a larger knowledge of the monopile foundation concept, centrifuge modeling is used by the geotechnical group at DTU. The centrifuge operated at DTU is a beam centrifuge and was built in 1976. In the recent years it has been upgraded with onboard data acquisition and control systems....... The capabilities of the centrifuge at DTU makes it possible to obtain a scale factor of 85 in experiments which equals a soil volume in prototype scale of a diameter of 40 meters and a depth of 40 meters. This paper describes centrifuge modeling theory, the centrifuge setup at DTU and as an example show results...... from centrifuge tests performed on large diameter piles installed in dry sand....

  11. El Sistema Vial Inca y los desafíos para su conservación en tiempos modernos

    OpenAIRE

    Ríos Canales, Moisés

    2013-01-01

    El Estado peruano, a través del Ministerio de Cultura, desarrolla dentro de su política cultural una estrategia para la identificación, protección, conservación y puesta en uso social del Sistema Vial Inca, el mayor monumento de la historia americana construida por el Estado Inca en el Siglo XV.

  12. Rapid Detection and Identification of Candidemia by Direct Blood Culturing on Solid Medium by Use of Lysis-Centrifugation Method Combined with Matrix-Assisted Laser Desorption Ionization-Time of Flight Mass Spectrometry (MALDI-TOF MS).

    Science.gov (United States)

    Idelevich, Evgeny A; Grünastel, Barbara; Becker, Karsten

    2017-01-01

    Candida sepsis is a life-threatening condition with increasing prevalence. In this study, direct blood culturing on solid medium using a lysis-centrifugation procedure enabled successful Candida species identification by matrix-assisted laser desorption-ionization time of flight mass spectrometry on average 3.8 h (Sabouraud agar) or 7.4 h (chocolate agar) before the positivity signal for control samples in Bactec mycosis-IC/F or Bactec Plus aerobic/F bottles, respectively. Direct culturing on solid medium accelerated candidemia diagnostics compared to that with automated broth-based systems. Copyright © 2016 American Society for Microbiology.

  13. Optimizing human semen cryopreservation by reducing test vial volume and repetitive test vial sampling

    DEFF Research Database (Denmark)

    Jensen, Christian F S; Ohl, Dana A; Parker, Walter R

    2015-01-01

    : Prospective clinical laboratory study. SETTING: University assisted reproductive technology (ART) laboratory. PATIENT(S): A total of 594 patients undergoing semen analysis and cryopreservation. INTERVENTION(S): Semen analysis, cryopreservation with different intermediate steps and in different volumes (50......-1,000 μL), and long-term storage in LN2 or VN2. MAIN OUTCOME MEASURE(S): Optimal TV volume, prediction of cryosurvival (CS) in ART procedure vials (ARTVs) with pre-freeze semen parameters and TV CS, post-thaw motility after two- or three-step semen cryopreservation and cryostorage in VN2 and LN2. RESULT......(S): Test vial volume of 50 μL yielded lower CS than other volumes tested. Cryosurvival of 100 μL was similar to that of larger volumes tested. An intermediate temperature exposure (-88°C to -93°C for 20 minutes) during cryopreservation did not affect post-thaw motility. Cryosurvival of TVs and ARTVs from...

  14. Residual volume in vials of antibiotics used in pediatrics

    Directory of Open Access Journals (Sweden)

    Caroline Magna Pessoa Chaves

    Full Text Available Abstract OBJECTIVE Quantifying residual volume contained in vials of antibiotics used in pediatrics. METHOD This is an experiment involving samples from vials of antibiotics used in a pediatric hospital. Residual volume was identified by calculating the difference in weight measurement before and after the vials were washed. Evaluation of the residual volume difference in the vials was determined by the Wilcoxon non-parametric test for a sample and established at a significance level of 5%. RESULTS 105 samples of antibiotics were selected. The correct use of the antibiotics oxacillin (88.57% and ceftriaxone (94.28% predominated with low residual values. The same did not occur for procaine benzylpenicillin + potassium benzylpenicillin, since a greater residual volume was discarded in 74.28% of the vials. CONCLUSION We highlight the need for improvements in managing antibiotics in the institution under study, so that the excess volume of the antibiotics in the vials is used within the acceptable stable time. It is also necessary that the disposal of the residual volume be adequately disposed, since it presents a risk to public health and the environment.

  15. RESEARCH CENTRIFUGE- ADVANCED TOOL SEPERATION

    OpenAIRE

    Mahajan Ashwini; Prof. B.V. Jain; Dr Surajj Sarode

    2015-01-01

    A centrifuge is a critical piece of equipment for the laboratory. Purpose of this study was to study research centrifuge in detail, its applications, uses in different branches and silent features. Their are two types of research centrifuge study here revolutionary research centrifuge and microprocessor research centrifuge. A centrifuge is a device that separates particles from a solution through use of a rotor. In biology, the particles are usually cells, sub cellular organelles, or large mo...

  16. Centrifugal pump handbook

    CERN Document Server

    Pumps, Sulzer

    2010-01-01

    This long-awaited new edition is the complete reference for engineers and designers working on pump design and development or using centrifugal pumps in the field. This authoritative guide has been developed with access to the technical expertise of the leading centrifugal pump developer, Sulzer Pumps. In addition to providing the most comprehensive centrifugal pump theory and design reference with detailed material on cavitation, erosion, selection of materials, rotor vibration behavior and forces acting on pumps, the handbook also covers key pumping applications topics and operational

  17. Agresividad vial en la población general

    OpenAIRE

    Fierro, Inmaculada; Gómez-Talegón, Trinidad; Álvarez, Francisco Javier

    2010-01-01

    Producción Científica Objetivos: Analizar la prevalencia y los factores sociodemográficos asociados con la agresividad vial en la población. Métodos: Se han realizado 2.500 entrevistas a la población de Castilla y León de entre 14 y 70 años de edad. Se evaluó la agresividad vial en el año previo a la realización de la encuesta utilizando un test de ocho preguntas. Resultados: El 31,1% refirió haber vivido alguna situación de agresividad vial en el último año, y el 26,8% en más de u...

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

    Science.gov (United States)

    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.

  19. Filtration of Glass Delamination Particles with West Pharmaceutical Vial Adapters.

    Science.gov (United States)

    Zarour-Shalev, Elinor H; Ovadia, Yaron; Tuchmay, Oren; Reynolds, Graham; Lev, Nimrod

    2015-01-01

    One major current challenge facing companies producing injectable drugs contained in glass vials is the phenomenon of delamination that results in drug contamination. Particulate contamination of parenteral fluids is a fact of life. Particulate infusion is unlikely to cause immediate or severe signs and symptoms, but adverse effects, tissue damage, and loss of function are likely in the long term. Since 2010, recalls due to glass delamination have increased, and recently the U.S. Food and Drug Administration exercised temporary regulatory flexibility by allowing filtration as means of removing glass particles. The vial adapter is a needle-free product from West Pharmaceuticals Services that provides a simple and cost-effective solution for the safe and rapid transfer reconstitution of drugs between vials and syringes. One variant of the vial adapter is integrated with a filter to address various types of particles. In the present study, the performance of the filter-integrated vial adapter is evaluated with respect to glass delamination particles. Silica particles of 0.5-10 μm are used to emulate glass delamination particles. High-filtration efficiency is demonstrated according to the severest criteria stated by the British Pharmacopoeia that allows up to 100 particles smaller than 5 μm for every 1 mL liquid of a large-volume parenteral. The study was conducted using environmental scanning electron microscopy and statistical analysis. One major current challenge facing companies producing injectable drugs contained in glass vials is the phenomenon of delamination that results in drug contamination. Glass delamination is defined as degradation of surface glass, as from a vial, that produces glass flakes. Contamination of injectable drugs due to glass delamination is a fact of life. Normally, this type of contamination does not involve immediate severe signs, but rather accumulative damage to tissues in the long run. Recently, the U.S. Food and Drug Administration

  20. Determining the delamination propensity of pharmaceutical glass vials using a direct stress method.

    Science.gov (United States)

    Sloey, Christopher; Gleason, Camille; Phillips, Joseph

    2013-01-01

    An accelerated lamellae formation (ALF) methodology has been developed to determine the delamination propensity and susceptibility of pharmaceutical glass vials. The ALF process consists of a vial wash and depyrogenation mimic procedure followed by stressing glass vials with 20 mM glycine pH 10.0 solution at 50 °C for 24 h and analyzing the resulting solutions by visual inspection for glass lamellae. ALF results demonstrate that while vial delamination propensity generally correlates with glass hydrolytic resistance, ALF is a more direct test of glass delamination propensity and is not affected by post-production vial washing that can affect results obtained using hydrolytic resistance tests. ALF can potentially be used by pharmaceutical companies to evaluate and screen incoming vial lots to minimize the risk of delamination during the shelf life of parenteral therapeutics, and by glass vial manufacturers to monitor and improve their vial manufacturing processes. Glass flakes can sometimes appear in liquid pharmaceutical drugs contained in glass vials. These glass flakes are a result of several factors related to the glass vial production process, glass vial sterilization procedures, and the formulation of the liquid pharmaceutical drug. Vial testing is routinely done in order to select glass vials that are less likely to form glass flakes. The factors leading to the formation of glass flakes were studied and applied to a method designed to directly screen vials for their propensity to form glass flakes. The washing of vials followed immediately by sterilization at high temperatures was determined to be a critical factor in the formation of glass flakes. As a result, a laboratory mimic of this procedure was incorporated into the newly developed method for screening vials. This mimic procedure as well as robust accelerated incubation conditions and a sensitive visual inspection procedure are key aspects of this vial screening method.

  1. Estudio integral de la accidentalidad vial en bicicletas

    OpenAIRE

    Sanromà Roger, Víctor

    2017-01-01

    El alcance de este proyecto es estudiar las causas que provocan los accidentes en que hay bicicletas implicadas y el posterior análisis de los diferentes tipos de tecnologías existentes para la seguridad vial de los ciclistas, para poder desarrollar mejoras que reduzcan la accidentalidad y que complementen las tecnologías ya existentes.

  2. Dosing Accuracy of Insulin Pens Versus Conventional Syringes and Vials

    NARCIS (Netherlands)

    Luijf, Y. M.; DeVries, J. H.

    2010-01-01

    Pen injection devices have acquired a pivotal role in insulin delivery, surpassing the use of conventional insulin syringes in many parts of the world. In this review we sought to determine differences in dosing accuracy between insulin pens and conventional syringes and vials, also touching on

  3. Residual volume in vials of antibiotics used in pediatrics.

    Science.gov (United States)

    Chaves, Caroline Magna Pessoa; Bezerra, Carolina Martins; Lima, Francisca Elisângela Teixeira; Cardoso, Maria Vera Lúcia Moreira Leitão; Fonseca, Said Gonçalves da Cruz; Silva, Viviane Martins da

    2017-06-12

    Quantifying residual volume contained in vials of antibiotics used in pediatrics. This is an experiment involving samples from vials of antibiotics used in a pediatric hospital. Residual volume was identified by calculating the difference in weight measurement before and after the vials were washed. Evaluation of the residual volume difference in the vials was determined by the Wilcoxon non-parametric test for a sample and established at a significance level of 5%. 105 samples of antibiotics were selected. The correct use of the antibiotics oxacillin (88.57%) and ceftriaxone (94.28%) predominated with low residual values. The same did not occur for procaine benzylpenicillin + potassium benzylpenicillin, since a greater residual volume was discarded in 74.28% of the vials. We highlight the need for improvements in managing antibiotics in the institution under study, so that the excess volume of the antibiotics in the vials is used within the acceptable stable time. It is also necessary that the disposal of the residual volume be adequately disposed, since it presents a risk to public health and the environment. Quantificar o volume residual contido em frascos-ampola de antibióticos utilizados na pediatria. Trata-se de um experimento com amostras de frascos-ampola de antibióticos utilizados em hospital pediátrico. O volume residual foi identificado calculando-se a diferença da aferição do peso antes e após a lavagem do frasco-ampola. A avaliação da diferença dos volumes residuais nos frascos-ampola foi determinada pelo teste não paramétrico de Wilcoxon para uma amostra e estabelecido o nível de significância de 5%. Foram selecionadas 105 amostras de antibióticos. Predominou o correto aproveitamento dos antibióticos oxacilina (88,57%) e ceftriaxona (94,28%), com baixos valores residuais. O mesmo não ocorreu com a benzilpenicilina procaína + potássica, pois em 74,28% dos frascos houve descarte de volume residual superior. Destaca-se a necessidade de

  4. Centrifugal blood pump 603

    Indian Academy of Sciences (India)

    Centrifugal blood pump 603 pressure obtained for real blood, as shown in figure 6, is a little higher than that for glycerin aqua Solution with the same viscosity as blood. This may indicate the effect of slight non-. Newtonian turbulent flow. The radial whirl motion of the impeller was observed by dual laser position sensors.

  5. Centrifugal Gas Compression Cycle

    Science.gov (United States)

    Fultun, Roy

    2002-11-01

    A centrifuged gas of kinetic, elastic hard spheres compresses isothermally and without flow of heat in a process that reverses free expansion. This theorem follows from stated assumptions via a collection of thought experiments, theorems and other supporting results, and it excludes application of the reversible mechanical adiabatic power law in this context. The existence of an isothermal adiabatic centrifugal compression process makes a three-process cycle possible using a fixed sample of the working gas. The three processes are: adiabatic mechanical expansion and cooling against a piston, isothermal adiabatic centrifugal compression back to the original volume, and isochoric temperature rise back to the original temperature due to an influx of heat. This cycle forms the basis for a Thomson perpetuum mobile that induces a loop of energy flow in an isolated system consisting of a heat bath connectable by a thermal path to the working gas, a mechanical extractor of the gas's internal energy, and a device that uses that mechanical energy and dissipates it as heat back into the heat bath. We present a simple experimental procedure to test the assertion that adiabatic centrifugal compression is isothermal. An energy budget for the cycle provides a criterion for breakeven in the conversion of heat to mechanical energy.

  6. The Human Centrifuge

    Science.gov (United States)

    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.

  7. Proteja a sus seres queridos de las lesiones viales

    Centers for Disease Control (CDC) Podcasts

    2008-12-10

    Este podcast, que forma parte de la iniciativa Proteja a sus seres queridos, aborda las medidas que pueden tomar los padres de familia para ayudar a proteger a sus niños de las lesiones viales, una de las principales causas de lesiones infantiles.  Created: 12/10/2008 by National Center for Injury Prevention and Control (NCIPC).   Date Released: 4/1/2009.

  8. Red Vial de Nicaragua (Optimización y Mantenimiento

    Directory of Open Access Journals (Sweden)

    Wilfredo Martínez

    2013-06-01

    Full Text Available La red vial es un patrimonio nacional, el cual es necesario: proteger, conservar, aumentar y mejorar; para apoyar eldesarrollo socioeconómico de nuestro país. La actividad de mantenimiento, constituye un factor determinante quegarantiza la operación satisfactoria del transporte durante la vida útil de los caminos; en sus diferentes modalidades. La ausencia de un mantenimiento preventivo y de un mantenimiento correctivo tardío, conduce a que la inversiónrealizada sufra una depreciación más acelerada, acortando su vida útil; obteniendo un grado de aprovechamientomenor que se traduce en una disminución de los beneficios estimados, ya que la rentabilidad no podrá ser óptima aldescuidar esta función. “Con frecuencia, los costos operativos de los vehículos, excederán los costos de losdepartamentos viales por un factor de 10 o màs, especialmente en carreteras de gran volumen de trànsito”.(Zaniewski, 1989. Por lo tanto, los costos (economía de los usuarios deben ser tomados en cuenta al momento deproyectar la construcción de una carretera. Por tal razón el Gobierno de Nicaragua, en conjunto con lasinstituciones correspondientes, han asumido un rol prioritario en la ejecución y mantenimiento de la red vial. Esteensayo pretende aportar elementos cuantitativos y cualitativos, para el análisis y mejoramiento de la Red Vial.

  9. Límites de la tarificación vial

    Directory of Open Access Journals (Sweden)

    Louis de Grange

    2015-01-01

    Full Text Available Para muchos académicos y profesionales de la ingeniería de transporte, el concepto de tarificación por congestión se ha transformado en el paradigma de la eficiencia en el uso de la escasa infraestructura vial y del desincentivo al uso excesivo del automóvil. Si bien la tarificación vial puede ser, en varios casos, una buena herramienta de gestión de tráfico, comporta también una serie de riesgos y sobreexpectativas que es importante tener en consideración a la hora de diseñar, implementar y administrar un eficiente esquema de tarificación vial. En este trabajo presentamos una serie de antecedentes, basados muchos de ellos en la literatura especializada y en evidencia empírica, que permiten describir los riesgos potenciales y eventuales sobreexpectativas que enfrenta una política de tarificación por congestión, lo que puede ser de gran ayuda para impulsar una correcta implementación de esta política de gestión de tráfico.

  10. Phase system selection with fractional factorial design for purification of recombinant cyanovirin-N from a hydroponic culture medium using centrifugal partition chromatography.

    Science.gov (United States)

    Grudzień, Łukasz; Madeira, Luisa; Fisher, Derek; Ma, Julian; Garrard, Ian

    2013-04-12

    Centrifugal partition chromatography (CPC) with an aqueous two-phase system (ATPS) was used to purify recombinant cyanovirin-N (CV-N) from other proteins which were co-secreted into a hydroponic plant medium in a rhizosecretion process. To achieve satisfactory protein concentration, the purification was preceded by ultrafiltration performed on a 5 kDa filter. ATPS, because of their gentle nature, were selected as the phase system for CPC. A systematic phase system selection was applied. This involved studying the effect of seven parameters of ATPS: polymer type, salt type, the polymer and salt concentration, the polymer molecular weight, pH, and presence of two additional salts; NaCl and NaClO4, which all together gave 320 combinations. design of experiment (DoE) software allowed the reduction of this number to 46. Having tested partitioning of cyanovirin-N and impurities in 46 ATPS, the three best potential phase systems generated by the programme were then tested on the CPC. Out of these three, 13/13% PEG4000 sodium phosphate, pH 3.0, proved to be most effective phase system in the purification of cyanovirin-N, judged by ELISA and SDS-PAGE analysis, as it eliminated most of the impurities from the final cyanovirin-N preparation. Copyright © 2013 Elsevier B.V. All rights reserved.

  11. Centrifugal Contactor Efficiency Measurements

    Energy Technology Data Exchange (ETDEWEB)

    Mincher, Bruce Jay [Idaho National Lab. (INL), Idaho Falls, ID (United States); Tillotson, Richard Dean [Idaho National Lab. (INL), Idaho Falls, ID (United States); Grimes, Travis Shane [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2017-01-01

    The contactor efficiency of a 2-cm acrylic centrifugal contactor, fabricated by ANL using 3D printer technology was measured by comparing a contactor test run to 5-min batch contacts. The aqueous phase was ~ 3 ppm depleted uranium in 3 M HNO3, and the organic phase was 1 M DAAP/dodecane. Sampling during the contactor run showed that equilibrium was achieved within < 3 minutes. The contactor efficiency at equilibrium was 95% to 100 %, depending on flowrate.

  12. Characterization of Surface Properties of Glass Vials Used as Primary Packaging Material for Parenterals.

    Science.gov (United States)

    Ditter, Dominique; Mahler, Hanns-Christian; Roehl, Holger; Wahl, Michael; Huwyler, Joerg; Nieto, Alejandra; Allmendinger, Andrea

    2018-01-10

    The appropriate selection of adequate primary packaging, such as the glass vial, rubber stopper, and crimp cap for parenteral products is of high importance to ensure product stability, microbiological quality (integrity) during storage as well as patient safety. A number of issues can arise when inadequate vial material is chosen, and sole compliance to hydrolytic class I is sometimes not sufficient when choosing a glass vial. Using an appropriate pre-treatment, such as surface modification or coating of the inner vial surface after the vial forming process the glass container quality is often improved and interactions of the formulation with the surface of glass may be minimized. This study aimed to characterize the inner surface of different type I glass vials (Exp33, Exp51, Siliconized, TopLyo TM and Type I plus®) at the nanoscale level. All vials were investigated topographically by colorimetric staining and Scanning Electron Microscopy (SEM). Glass composition of the surface was studied by Time-of-Flight - Secondary Ion Mass Spectrometry (ToF-SIMS) and X-ray Photoelectron Spectroscopy (XPS), and hydrophobicity/hydrophilicity of the inner surface was assessed by dye tests and surface energy measurements. All containers were studied unprocessed, as received from the vendor, i.e. in unwashed and non-depyrogenized condition. Clear differences were found between the different vial types studied. Especially glass vials without further surface modifications, like Exp33 and Exp51 vials, showed significant (I) vial-to-vial variations within one vial lot as well as (II) variations along the vertical axis of a single vial when studying topography and chemical composition. In addition, differences and heterogeneity in surface energy were found within a given tranche (circumferential direction) of Exp51 as well as Type I plus® vials. Most consistent quality was achieved with TopLyo TM vials. The present comprehensive characterization of surface properties of the

  13. Effects of vial packing density on drying rate during freeze-drying of carbohydrates or a model protein measured using a vial-weighing technique.

    Science.gov (United States)

    Gieseler, Henning; Lee, Geoffrey

    2008-02-01

    To determine the effects of vial packing density in a laboratory freeze dryer on drying rate profiles of crystalline and amorphous formulations. The Christ freeze-drying balance measured cumulative water loss, m(t), and instantaneous drying rate, m(t), of water, mannitol, sucrose and sucrose/BSA formulations in commercial vials. Crystalline mannitol shows drying rate behaviour indicative of a largely homogeneous dried-product layer. The drying rate behaviour of amorphous sucrose indicates structural heterogeneity, postulated to come from shrinkage or microcollapse. Trehalose dries more slowly than sucrose. Addition of BSA to either disaccharide decreases primary drying time. Higher vial packing density greatly reduces drying rate because of effects of radiation heat transfer from chamber walls to test vial. Plots of m(t) versus radical t and m(t) versus layer thickness (either ice or dried-product) allow interpretation of changes in internal cake morphology during drying. Vial packing density greatly influences these profiles.

  14. How Vial Geometry Variability Influences Heat Transfer and Product Temperature During Freeze-Drying.

    Science.gov (United States)

    Scutellà, Bernadette; Passot, Stéphanie; Bourlés, Erwan; Fonseca, Fernanda; Tréléa, Ioan Cristian

    2017-03-01

    Vial design features can play a significant role in heat transfer between the shelf and the product and, consequently, in the final quality of the freeze-dried product. Our objective was to investigate the impact of the variability of some geometrical dimensions of a set of tubing vials commonly used for pharmaceuticals production on the distribution of the vial heat transfer coefficients (Kv) and its potential consequence on product temperature. Sublimation tests were carried out using pure water and 8 combinations of chamber pressure (4-50 Pa) and shelf temperature (-40°C and 0°C) in 2 freeze-dryers. Kv values were individually determined for 100 vials located in the center of the shelf. Vial bottom curvature depth and contact area between the vial and the shelf were carefully measured for 120 vials and these data were used to calculate Kv distribution due to variability in vial geometry. At low pressures commonly used for sensitive products (below 10 Pa), the vial-shelf contact area appeared crucial for explaining Kv heterogeneity and was found to generate, in our study, a product temperature distribution of approximately 2°C during sublimation. Our approach provides quantitative guidelines for defining vial geometry tolerance specifications and product temperature safety margins. Copyright © 2017 American Pharmacists Association®. Published by Elsevier Inc. All rights reserved.

  15. Edificio de oficinas. Viale di Trastevere – Roma

    Directory of Open Access Journals (Sweden)

    Lafuente, Julio G.

    1958-09-01

    Full Text Available El solar, largo y estrecho, en esquina a Viale di Trastevere y Via Carlo Porta, y con fachada posterior a amplio patio de manzana, ha permitido resolver el bloque de viviendas en tres unidades alineadas, cada una de cuyas escaleras da acceso a dos viviendas por planta. No obstante, al exterior, el conjunto ha sido concebido con gran unidad de composición, jugando un papel importante el ritmo vigoroso de terrazas y paños ciegos de fábrica de ladrillo de sus miradores.

  16. Centrifuge modelling of capillary rise

    OpenAIRE

    Depountis, N.; DAVIES, MCR; Harris, C; Burkhart, S; THOREL, L; A. Rezzoug; Konig, D; Merrifield, C; CRAIG, WH

    2001-01-01

    This paper reports results from centrifuge tests designed to investigate capillary rise in soils subjected to different gravitational fields. The experimental programme is part of the EU-funded NECER project (Network of European Centrifuges for Environmental Geotechnic Research), whose objective is to investigate the appropriateness of geotechnical centrifuge modelling for the investigation of geoenvironmental problems, particularly with reference to partially saturated soils. The tests were ...

  17. National geotechnical centrifuge

    Science.gov (United States)

    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.

  18. CRITERIOS E INDICADORES DE SOSTENIBILIDAD EN EL SUBSECTOR VIAL

    Directory of Open Access Journals (Sweden)

    Martha Melizza Ordoñez Díaz

    2015-01-01

    Full Text Available Actualmente en Colombia el desempeño de un contratista de obra se determina de acuerdo con los avances y resultados obtenidos en la construcción de la misma, mas no por su desempeño ambiental; sin embargo, cualquier tipo de obra civil se puede llevar a cabo con mayor o menor complejidad, dependiendo de la disponibilidad de recursos naturales en la zona y la visión que tenga la comunidad sobre el proyecto, de tal forma que la inversión económica y el tiempo de ejecución no solo dependerá de las actividades y costos netos de las obras civiles sino, además, de factores ambientales y sociales propios del lugar de ejecución. Con esta revisión bibliográfica sobre indicadores y guías ambientales internacionales, se pretende incentivar la sostenibilidad como eje transversal de los proyectos viales en Colombia, fortalecer las medidas de manejo socioambiental y mejorar el seguimiento y evaluación de los proyectos viales en el marco del equilibrio social, ambiental y económico que impulsa el desarrollo sostenible

  19. Effectiveness of Needleless Vial Adaptors and Blunt Cannulas for Drug Administration in a Microgravity Environment

    Science.gov (United States)

    Hailey, M.; Bayuse, T.

    2010-01-01

    Fluid Isolation in the medication vial: Air/ fluid isolation maneuvers were used to move the medication to the septum end of vial. This isolation may be achieved in multiple ways based on the experience of the astronaut with fluid management in microgravity. If vial adaptors/blunt cannula or syringe assembly is inserted into the to vial before fluid isolation commences, the stability of this assembly should be considered in an effort to limit the risk of "slinging off" of the vial during isolation. Alternatively, fluid isolation can be performed prior to attaching the syringe/vial adaptor assembly. Terrestrial practices for medication withdrawal from a nonvented vial require injection of an equivalent amount of air as the expected medication volume prior to withdrawing liquid. In microgravity, this action is still valid, however the injection of additional air into the vial creates a multitude of micro bubbles and increases the volume of medication mixed with air that then must be withdrawn to achieve the desired drug volume in syringe. This practice is more likely to be required when using vials >30ml in size and injection volumes >10mL. It is felt that based on the microgravity flight, the practice of air injection is more of a hindrance than help.

  20. Inventarios viales y categorización de la red vial en estudios de Ingeniería de Tránsito y Transporte

    OpenAIRE

    Julián Rodrigo Quintero

    2011-01-01

    Se presentan las principales consideraciones y los aspectos técnicos fundamentales de la elaboración de Inventarios Viales y la Categorización de la Red Vial, aplicadas a la realización de estudios de ingeniería de tránsito y transporte. Se exponen los aspectos generales relacionados con la elaboración de los inventarios de infraestructura vial, de señalización y dispositivos de control, de estacionamientos, de paraderos y de rutas de transporte público colectivo urbano de pasajeros, como una...

  1. Centrifugal seeding of mammalian cells in nonwoven fibrous matrices.

    Science.gov (United States)

    Ng, Robin; Gurm, Jesse Singh; Yang, Shang-Tian

    2010-01-01

    Three-dimensional (3D) cell cultures have many advantages over two-dimensional cultures. However, seeding cells in 3D scaffolds such as nonwoven fibrous polyethylene terephthalate (PET) matrices has been a challenge task in tissue engineering and cell culture bioprocessing. In this study, a centrifugal seeding method was investigated to improve the cell seeding efficiency in PET matrices with two different porosities (93% and 88%). Both the centrifugal force and centrifugation time were found to affect the seeding efficiency. With an appropriate centrifugation speed, a high 80-90% cell seeding efficiency was achieved and the time to reach this high seeding efficiency was less than 5 min. The seeding efficiency was similar for matrices with different porosities, although the optimal seeding time was significantly shorter for the low-porosity scaffold. Post seeding cell viability was demonstrated by culturing colon cancer cells seeded in PET matrices for over 5 days. The centrifugal seeding method developed in this work can be used to efficiently and uniformly seed small fibrous scaffolds for applications in 3D cell-based assays for high-throughput screening.

  2. [Galileo and centrifugal force].

    Science.gov (United States)

    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.

  3. Seguridad vial en carreteras rurales de dos carriles

    Directory of Open Access Journals (Sweden)

    R García

    Full Text Available La presente investigación se realiza con el objetivo de evaluar la seguridad vial en carreteras rurales de dos carriles de interés nacional en la provincia de Sancti Spíritus, a partir del procedimiento desarrollado en la Universidad Central de Las Villas (UCLV, donde se realiza la caracterización de la accidentalidad, la identificación de los tramos de mayor peligrosidad y la identifican los factores de riesgos, en el tramos de mayor peligrosidad, para con esta información formular las posibles acciones a efectuar en el tramo, las cuales luego de su aprobación por los organismos rectores de la vialidad se implementan, y transcurrido un período de tiempo pueden ser evaluadas para comprobar su efectividad.

  4. Analysis of pressurization of plutonium oxide storage vials during a postulated fire

    Energy Technology Data Exchange (ETDEWEB)

    Laurinat, J.; Kesterson, M.; Hensel, S.

    2015-02-10

    The documented safety analysis for the Savannah River Site evaluates the consequences of a postulated 1000 °C fire in a glovebox. The radiological dose consequences for a pressurized release of plutonium oxide powder during such a fire depend on the maximum pressure that is attained inside the oxide storage vial. To enable evaluation of the dose consequences, pressure transients and venting flow rates have been calculated for exposure of the storage vial to the fire. A standard B vial with a capacity of approximately 8 cc was selected for analysis. The analysis compares the pressurization rate from heating and evaporation of moisture adsorbed onto the plutonium oxide contents of the vial with the pressure loss due to venting of gas through the threaded connection between the vial cap and body. Tabulated results from the analysis include maximum pressures, maximum venting velocities, and cumulative vial volumes vented during the first 10 minutes of the fire transient. Results are obtained for various amounts of oxide in the vial, various amounts of adsorbed moisture, different vial orientations, and different surface fire exposures.

  5. Effectiveness of Needles Vial Adaptors and Blunt Cannulas for Drug Administration in a Microgravity Environment

    Science.gov (United States)

    Hailey, Melinda; Bayuse, Tina

    2009-01-01

    The need for a new system of injectable medications aboard the International Space Station (ISS) was identified. It is desired that this system fly medications in their original manufacturer's packaging, allowing the system to comply with United States Pharmacopeia (USP) guidelines while minimizing the resupply frequency due to medication expiration. Pre-filled syringes are desired, however, the evolving nature of the healthcare marketplace requires flexibility in the redesign. If medications must be supplied in a vial, a system is required that allows for the safe withdrawal of medication from the vial into a syringe for administration in microgravity. During two reduced gravity flights, the effectiveness of two versions of a blunt cannula and needleless vial adaptors was evaluated to facilitate the withdrawal of liquid medication from a vial into a syringe for injection. Other parameters assessed included the ability to withdraw the required amount of medication and whether this is dependent on vial size, liquid, or the total volume of fluid within the vial. Injectable medications proposed for flight on ISS were used for this evaluation. Due to differing sizes of vials and the fluid properties of the medications, the needleless vial adaptors proved to be too cumbersome to recommend for use on the ISS. The blunt cannula, specifically the plastic version, proved to be more effective at removing medication from the various sizes of vials and are the recommended hardware for ISS. Fluid isolation within the vials and syringes is an important step in preparing medication for injection regardless of the hardware used. Although isolation is a challenge in the relatively short parabolas during flight, it is not an obstacle for sustained microgravity. This presentation will provide an overview of the products tested as well as the challenges identified during the microgravity flights.

  6. Development of the detection threshold concept from a close look at sorption occurrence inside a glass vial based on the in-vial vaporization of semivolatile fatty acids.

    Science.gov (United States)

    Kim, Yong-Hyun; Kim, Ki-Hyun; Szulejko, Jan E; Parker, David

    2014-07-01

    Headspace (HS) analysis has been recommended as one of the most optimal methods for extracting and analyzing volatile organic compounds from samples in diverse media such as soil and water. Short-chain volatile fatty acids (VFA, C3-C7) with strong adsorptivity were selected as the target compounds to assess the basic characteristics of the HS analysis through simulation of HS conditions by in-vial vaporization of liquid-phase standards (VL) in 25 mL glass vials. The reliability of the VL approach was assessed by apportioning the in-vial VFA mass into three classes: (1) vaporized fraction, (2) dynamic adsorption on the vial walls (intermediate stage between vaporization and irreversible absorption), and (3) irreversible absorptive loss (on the vial wall). The dynamic adsorption partitioning inside the vial increased with n-VFA carbon number, e.g., 43% (C2: acetic acid, extrapolated value), 65% (C3: propanoic acid), and 98% (C7: heptanoic acid). The maximum irreversible losses for the studied n-VFAs exhibited a quadratic relationship with carbon number. If the detection threshold limit (DTL: the onset of mass detection after attaining the maximum irreversible loss) is estimated, the DTL values for target VFAs were in the range of 101 ng for i-valeric acid to 616 ng for propionic acid, which are larger than the method detection limit by about 3 orders of magnitude. Consequently, quantitation of VFAs using the VL approach should be critically assessed by simultaneously considering the DTL criterion and the initial VFA masses loaded into the vial.

  7. Glass delamination: a comparison of the inner surface performance of vials and pre-filled syringes.

    Science.gov (United States)

    Zhao, Jianxiu; Lavalley, Virginie; Mangiagalli, Paolo; Wright, Justin M; Bankston, Theresa E

    2014-12-01

    The occurrence of glass delamination is a serious concern for parenteral drug products. Over the past several years, there has been a series of product recalls involving glass delamination in parenteral drugs stored in vials which has led to heightened industry and regulatory scrutiny. In this study, a two-pronged approach was employed to assess the inner surface durability of vials and pre-filled syringes. Non-siliconized syringes were used in order to directly compare glass to glass performance between vials and syringes. The vial and syringe performance was screened with pharmaceutically relevant formulation conditions. The influence of pH, buffer type, ionic strength, and glass type and source was evaluated. In addition, an aggressive but discriminating formulation condition (glutaric acid, pH 11) was used to ascertain the impact of syringe processing. Advanced analytical tools including inductively coupled plasma/mass spectrometry, scanning electron microscopy, atomic force microscopy, and dynamic secondary ion mass spectroscopy showed significant differences in glass performance between vials and syringes. Pre-filled syringes outperform vials for most tests and conditions. The manufacturing conditions for vials lead to glass defects, not found in pre-filled syringes, which result in a less chemically resistant surface. The screening methodology presented in this work can be applied to assess suitability of primary containers for specific drug applications.

  8. Valoraciones sobre la gestión del sistema de seguridad vial en Cuba.

    Directory of Open Access Journals (Sweden)

    Tania Ivón Sosa Ibarra

    2015-12-01

    Full Text Available El presente trabajo tiene como objetivo valorar con enfoque crítico el cumplimiento de la agenda del Observatorio Iberoamericano para la Seguridad Vial (OISEVI que evidencie los aciertos y desaciertos en esta actividad, se analiza en la literatura los enfoques de los autores Tony Bliss y Jeanne Breen que enfatizan en la concepción de sistema no solo a la seguridad vial sino también a la gestión de esta como sistema y se realiza una aplicación de los aspectos de la encuesta del OISEVI a la gestión de la seguridad vial en Cuba por el grupo de asesores de la Comisión Nacional de seguridad vial, pertenecientes a la Universidad de Sancti Spíritus, que durante los últimos años estudian esta problemática, detallando los argumentos que conciben para otorgar los valores en las respuestas al cuestionario. Con esta encuesta se obtiene una primera aproximación del estado de la gestión de la seguridad vial en el país, y se arriban a valoraciones acerca de cómo se encuentra Cuba respecto a los lineamientos básicos y generales que hacen exitosa a la gestión en seguridad vial, basada en los cinco pilares del Plan Mundial para el Decenio de Acción para la Seguridad Vial 2011-2020.

  9. Centrifugal Compressor Aeroelastic Analysis Code

    Science.gov (United States)

    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.

  10. Evaluation of the open vial method in the radon measurement; Evaluacion del metodo del vial abierto en la medicion de radon

    Energy Technology Data Exchange (ETDEWEB)

    Lopez del Rio, H.; Davila R, J. I.; Mireles G, F., E-mail: hlopezdelrio@hotmail.com [Universidad Autonoma de Zacatecas, Unidad Academica de Estudios Nucleares, Cipres No. 10, Fracc. La Penuela, 98068 Zacatecas (Mexico)

    2014-10-15

    The open vial method is a simple technique, under-utilized but that take advantage of the great radon solubility in organic solvents, therefore applies in the measurement of the radon concentration exhaled in soil. The method consists on the exposition to the gas radon of an open vial with scintillating solution. An integral mathematical model for indoors that describes the emanation processes and gas radon exhalation was developed, as well as the radon dissolution in the scintillation liquid, besides obtaining the characteristic parameters of the experimental system proposed for the radon concentration calculation exhaled by soils. Two experimental arrangements were designed with exposition cameras of 12 and 6 L and quantity of different soil. The open vial was prepared with a mixture of 8 ml of deionized water and 12 ml of scintillation liquid OptiPhase Hi Safe 3 in polyethylene vials; the measurements of the dissolved radon were carried out in scintillation liquid equipment. As a result, on average 2.0% of the exhaled radon is dissolved in the open vial and the dissolved fraction is independent of the experimental arrangement. Also was observed that the exposition time does not affect the radon dissolution significantly, in correspondence with the reported in the literature. (Author)

  11. Evaluation of septum-capped vials for storage of gas samples during air transport.

    Science.gov (United States)

    Glatzel, Stephan; Well, Reinhard

    2008-01-01

    In order to provide information on the suitability of commonly used gas storage vials for air transport, we tested two vial types on their ability to preserve defined nitrous oxide concentrations and excess pressure when exposed to low pressure, low temperature and puncture by needles. Unlike in Crimp Cap vials, in Exetainers no nitrous oxide loss following low pressure storage was detectable. Tightness of Exetainers following multiple puncture was best using a small needle diameter. Pressure loss following 5, 10, or 25 punctures was lowest in the Exetainers. We conclude that Exetainers are suitable for storing gas samples for an extended period of time during aircraft transport.

  12. Introduction: Centrifuge and Fragmentation

    Directory of Open Access Journals (Sweden)

    Helena Goscilo

    2000-01-01

    Full Text Available The seismic changes inaugurated by desovietization not only recast the entire framework of Russia's cultural priorities, production, and reception, but ultimately revised fundamental concepts of what constitutes culture…

  13. Educación vial y movilidad en la Infancia

    Directory of Open Access Journals (Sweden)

    Fernando Martín Poó

    Full Text Available Resumen:La motorización creciente de los desplazamientos ha convertido al ambiente urbano en un lugar cada vez más hostil para los niños y niñas, quienes se encuentran entre los grupos humanos más vulnerables del tránsito. En esta etapa del desarrollo, la educación puede ser una herramienta clave para prevenir comportamientos de riesgo y promocionar hábitos de movilidad más saludables. El presente trabajo discute algunos aspectos relacionados con la educación vial en la infancia. Se destaca la importancia de considerar los patrones de movilidad típicos de cada edad, y de promover el uso de medios de transporte más saludables, equitativos y sustentables. Se señala además la necesidad de complementar las acciones educativas con intervenciones multi-sectoriales a diferente nivel.

  14. Centrifugation. A theoretical study of oxygen enrichment by centrifugation

    Energy Technology Data Exchange (ETDEWEB)

    Kierkegaard, P.; Raetz, E.

    1998-12-01

    In the present paper we first investigate what happens if we fill a cylinder with air, close it and rotate it. The results show that no matter which peripheral speed is used, it is not possible by means of the radial separation effect alone, to enrich the oxygen concentration from the previous 21% to more then 23.3%, which is of no practical value. In case of a too low enrichment in one centrifuge, the wanted material from this centrifuge can be used as an input for a second centrifuge and so on, in this way forming a cascade of centrifuges. Oxygen will be enriched in each step, until the desired concentration is reached. Cascading was the technology in the very beginning by enrichment plants for uraniumhexaflouride, used for atomic weapons and nuclear power plants. In this study we try to avoid cascading by aiming for higher separation factors. Therefore, we next investigate the possibilities of using a countercurrent centrifuge where in principle the enriched gas is subjected to several centrifugation in the same centrifuge. The calculations show, that in this way it is possible to produce nearly a 100% pure oxygen (polluted with some heavier molecules like argon) in one machine. Our third step was to calculate the amount of oxygen produced per hour. Using a countercurrent centrifuge of the Zippe type, 100 cm high and 20 cm in diameter, it is or will be possible in the near future to produce 17 g enriched air per hour enriched to 50% oxygen. That corresponds to processing 1 m{sup 3} atmospherical air in the period of approximately 24 hours. This is not very impressive. Our fourth step was to estimate the amount of power used for producing this amount of oxygen. A rough, but complicated, estimate shows that the power consumption at the production level will be about the double of the consumption used today. The overall conclusion is, that centrifugation as a production method for oxygen (or nitrogen) will not be competitive with the currently used method in the

  15. Inventarios viales y categorización de la red vial en estudios de Ingeniería de Tránsito y Transporte

    Directory of Open Access Journals (Sweden)

    Julián Rodrigo Quintero

    2011-03-01

    Full Text Available Se presentan las principales consideraciones y los aspectos técnicos fundamentales de la elaboración de Inventarios Viales y la Categorización de la Red Vial, aplicadas a la realización de estudios de ingeniería de tránsito y transporte. Se exponen los aspectos generales relacionados con la elaboración de los inventarios de infraestructura vial, de señalización y dispositivos de control, de estacionamientos, de paraderos y de rutas de transporte público colectivo urbano de pasajeros, como una herramienta práctica para complementar los procedimientos de campo y optimizar los procesos y análisis de resultados orientados a identificar, caracterizar y cuantificar las variables relacionadas con el desarrollo del fenómeno del tránsito y la actividad del transporte.

  16. CENTRIFUGAL MEMBRANE FILTRATION

    Energy Technology Data Exchange (ETDEWEB)

    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

  17. Dual centrifugation - A new technique for nanomilling of poorly soluble drugs and formulation screening by an DoE-approach.

    Science.gov (United States)

    Hagedorn, Martin; Bögershausen, Ansgar; Rischer, Matthias; Schubert, Rolf; Massing, Ulrich

    2017-09-15

    The development of nanosuspensions of poorly soluble APIs takes a lot of time and high amount of active material is needed. In this publication the use of dual centrifugation (DC) for an effective and rapid API-nanomilling is described for the first time. DC differs from normal centrifugation by an additional rotation of the samples during centrifugation, resulting in a very fast and powerful movement of the samples inside the vials, which - in combination with milling beads - result in effective milling. DC-nanomilling was compared to conventional wet ball milling and results in same or even smaller particle sizes. Also drug concentrations up to 40% can be processed. The process is fast (typical 90min) and the temperature can be controlled. DC-nanomilling appears to be very gentle, experiments showed no change of the crystal structure during milling. Since batch sizes are very small (100-1000mg) and since 40 sample vials can be processed in parallel, DC is ideal for the screening of suitable polymer/surfactant combinations. Fenofibrate was used to investigate DC-nanomilling for formulation screening by applying a DoE-approach. The presented data also show that the results of DC-nanomilling experiments are highly comparable to the results obtained by common agitator mills. Copyright © 2017 Elsevier B.V. All rights reserved.

  18. Comparison of Oil Sorbent/Vial Kit for Sampling and Preservation of Liquid Volatile Petroleum

    National Research Council Canada - National Science Library

    Shoji Kurata; Takeshi Iyozumi; Naoyuki Aizawa

    2010-01-01

      An oil sorbent sheet made of nonwoven polypropylene fiber and a vial with screw cap were assessed as the test kit for sampling and preservation of liquid volatile petroleum samples in the forensic science field...

  19. Seguridad vial y peatonal: una aproximacion teorica desde la politica publica

    National Research Council Canada - National Science Library

    Pico Merchan, Maria Eugenia; Gonzalez Perez, Rosa Elena; Norena Aristizabal, Olga Patricia

    2011-01-01

    Introduccion: la seguridad vial se constituye en una de las grandes preocupaciones de los paises donde, por los procesos acelerados de desarrollo y expansion de las ciudades, sobresalen los vehiculos sobre los peatones. Objetivo...

  20. Nondestructive detection of glass vial inner surface morphology with differential interference contrast microscopy.

    Science.gov (United States)

    Wen, Zai-Qing; Torraca, Gianni; Masatani, Peter; Sloey, Christopher; Phillips, Joseph

    2012-04-01

    Glass particles generated by glass dissolution and delamination of the glass container for pharmaceutical products have become a major issue in the pharmaceutical industry. The observation of glass particles in certain injectable drugs, including several protein therapeutics, has recently resulted in a number of product recalls. Glass vial surface properties have been suggested to play a critical role in glass dissolution and delamination. Surface characterization of glass container, therefore, is important to evaluate the quality of the glass container. In this work, we demonstrate that differential interference contrast (DIC) microscopy is a powerful, effective, and convenient technique to examine the inner surface morphology of glass vials nondestructively. DIC microscopy does not require the cutting of the glass vial for scanning the inner surface and has sufficient spatial resolution to reveal glass pitting, phase separation, delamination scars, and other defects. Typical surface morphology of pharmaceutical glass vials with different alkalinity are compared and discussed. Copyright © 2012 Wiley Periodicals, Inc.

  1. Bacterial contamination of propofol vials used in operating rooms of a third-level hospital.

    Science.gov (United States)

    Zorrilla-Vaca, Andrés; Escandón-Vargas, Kevin; Brand-Giraldo, Vanessa; León, Tatiana; Herrera, Mónica; Payán, Andrey

    2016-01-01

    We found a 6.1% bacterial contamination rate among 198 propofol vials collected after clinical use in 12 operating rooms of a high-complexity hospital in Cali, Colombia. Some propofol vials were used for extended periods (up to 72 hours), and only 26.1% of vials were punctured once. Median time of use, although not statistically significant, was higher in positive samples (7.2 vs 3.5 hours, P = .08). Education on the topic should stress that vials are single-patient use and must be immediately discarded after use. Copyright © 2016 Association for Professionals in Infection Control and Epidemiology, Inc. Published by Elsevier Inc. All rights reserved.

  2. MALDI-TOF MS based carbapenemase detection from culture isolates and from positive blood culture vials

    National Research Council Canada - National Science Library

    Ghebremedhin, B; Halstenbach, A; Smiljanic, M; Kaase, M; Ahmad-Nejad, P

    2016-01-01

    .... Our mass spectrometry-based assay was validated with 63 carbapenemase-producing Gram-negative bacterial isolates, and 35 carbapenem-resistant Gram-negative species with no carbapenemase production...

  3. Rotatingwall Technique and Centrifugal Separation

    Science.gov (United States)

    Anderegg, François

    This chapter describes the "rotating wall" technique which enables essentially unlimited confinement time of 109-1010 charged particles in a Penning trap. The applied rotating wall electric field provides a positive torque that counteracts background drags, resulting in radial compression or steady-state confinement in near-thermal equilibrium states. The last part of the chapter discusses centrifugal separation in a rotating multi-species non-neutral plasma. Separation occurs when the centrifugal energy is larger than the mixing due to thermal energy.

  4. MEANS FOR DETERMINING CENTRIFUGE ALIGNMENT

    Science.gov (United States)

    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.

  5. Una alternativa para la formación vial

    Directory of Open Access Journals (Sweden)

    Carolina Belén Tencio Blanco

    2008-01-01

    Full Text Available Este artículo muestra de manera general la problemática que actualmente se vive a nivel mun-dial, y que ha venido aumentado año tras año en la sociedad costarricense, con cifras alarmantes donde la edad, el sexo, el credo, status social no escapan a tal situación, y que afecta las diferentes áreas sociales que velan por el bienestar de todos, una problemática que desencadena un sin fin de consecuencias fatales: los accidentes de tránsito. Esta epidemia como la llama la OMS (Organización Mundial de la Salud, ha sido desde ya hace décadas una enfermedad silen-ciosa, donde no se encuentran soluciones eficaces que acaben con tantas secuelas que deja a su paso, a pesar del esfuerzo de muchas instituciones del país. Es así como se pretende desarrollar una iniciativa desde una perspectiva que oriente la búsqueda de soluciones, desde las raíces de nuestra cultura, por medio de una formación integral continua desde edades tempranas. Esta tarea sin lugar a dudas le corresponde a todos los que somos partícipes, pero la visión y misión de formar ciudadanos concientes de sus derechos, sin olvidar sus deberes en armonía con lo que le rodea desde principios que demuestran una sociedad más responsable y segura, le corresponde al sistema edu-cativo costarricense, en conjunto con las diversas enti-dades que de una u otra forma son parte de esta situa-ción. Esto con el objetivo de encontrar en la educación continua y sistemática, una herramienta efectiva que a mediano o largo plazo logre disminuir las estadísticas de muertes en carretera, por la negligencia o error humano, causa de mayor incidencia en los accidentes de tránsito, por medio de una formación en y para una cultura vial, cuya política e ideología sea respetar la vida en la búsqueda del bienestar común.

  6. Continuous-Flow Centrifugal Separator

    Science.gov (United States)

    Waldron, Robert D.

    1988-01-01

    Apparatus combines principles of centrifugal and cyclone separators to control movement of solid or liquid particles suspended in flowing gas. Spinning disk contains radial channels, width varys as function of distance from center. Gas flows from outer ring around disk toward center. Particles in gas collected at periphery, center or both.

  7. theory of batchwise centrifugal casting

    NARCIS (Netherlands)

    Biesheuvel, P.M.; Biesheuvel, Pieter Maarten; Nijmeijer, Arian; Verweij, H.

    1998-01-01

    In batchwise centrifugal casting a cylindrical mold is filled with suspension and rotated rapidly around its axis. This results in the movement of the particulate phase toward the cylinder wall and the formation of a tubular cast. Theory is presented for particle transport in the suspension phase

  8. Novel Mechanism of Glass Delamination in Type 1A Borosilicate Vials Containing Frozen Protein Formulations.

    Science.gov (United States)

    Jiang, Ge; Goss, Monica; Li, Guiyang; Jing, Wendy; Shen, Hong; Fujimori, Kiyoshi; Le, Linda; Wong, Lyanne; Wen, Zai-Qing; Nashed-Samuel, Yasser; Riker, Ken; Germansderfer, Abe; Tsang, Paul; Ricci, Margaret

    2013-01-01

    Storing protein formulations in the frozen state typically improves stability during long-term storage as a drug substance or as a drug product. The frozen state minimizes chemical degradation and physical instability. However, the frozen state is not an optimal storage condition for the glass vial itself. A significant issue was observed when small, flake-like pieces of glass particles (lamellae) appeared in vials containing thawed protein product. The occurrence of glass particles during freeze-thaw results in product rejection and potentially, adverse events. In recent years, glass flakes due to chemical delamination have been observed in parenteral liquid formulations after long-term storage, resulting in a number of product recalls. In this study, for the first time, glass delamination is reported in pharmaceutical glass vials containing frozen protein formulation, caused by a novel mechanism involving thermally-induced mechanical stress. In this article, a monoclonal antibody drug product in glass vials and the corresponding placebo vials were studied to identify the contributing factors from the freeze-thaw process, such as freezing temperature, the presence or absence of protein, and other handling conditions. Freezing temperature was found to be the most critical factor. Glass lamellae were only observed when the products were frozen to -70 °C, while freezing only to -30 °C did not cause any lamellae formation even after multiple freeze-thaw cycles. Protein concentration and the handling of the vials were also identified as contributing factors. A concentration gradient which formed after freeze-thaw induced a higher rate of lamellae occurrence in a subsequent freeze-thaw cycle compared to vials without the concentration gradient. Analyses by Fourier transform infrared spectroscopy and scanning electron microscopy/energy dispersive spectroscopy confirmed that the flake-like lamellae were thin, flat glass particles. Defects corresponding to the glass

  9. Prediction of the acoustic and bubble fields in insonified freeze-drying vials.

    Science.gov (United States)

    Louisnard, O; Cogné, C; Labouret, S; Montes-Quiroz, W; Peczalski, R; Baillon, F; Espitalier, F

    2015-09-01

    The acoustic field and the location of cavitation bubble are computed in vials used for freeze-drying, insonified from the bottom by a vibrating plate. The calculations rely on a nonlinear model of sound propagation in a cavitating liquid [Louisnard, Ultrason. Sonochem., 19, (2012) 56-65]. Both the vibration amplitude and the liquid level in the vial are parametrically varied. For low liquid levels, a threshold amplitude is required to form a cavitation zone at the bottom of the vial. For increasing vibration amplitudes, the bubble field slightly thickens but remains at the vial bottom, and the acoustic field saturates, which cannot be captured by linear acoustics. On the other hand, increasing the liquid level may promote the formation of a secondary bubble structure near the glass wall, a few centimeters below the free liquid surface. These predictions suggest that rather complex acoustic fields and bubble structures can arise even in such small volumes. As the acoustic and bubble fields govern ice nucleation during the freezing step, the final crystal's size distribution in the frozen product may crucially depend on the liquid level in the vial. Copyright © 2015 Elsevier B.V. All rights reserved.

  10. Centrifugal separator devices, systems and related methods

    Science.gov (United States)

    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.

  11. Centrifugal pumps and allied machinery

    CERN Document Server

    Anderson, HH

    1994-01-01

    This book will be of vital interest to all engineers and designers concerned with centrifugal pumps and turbines. Including statistical information derived from 20000 pumps and 700 turbines with capacities of 5gpm to 5000000gpm, this book offers the widest range and scope of information currently available. Statistical analyses suggest practical methods of increasing pump performance and provide valuable data for new design aspects.

  12. Experiencia-modelo piloto de los talleres de seguridad vial, como alternativa a la pena privativa de libertad en los delitos contra la seguridad vial

    Directory of Open Access Journals (Sweden)

    Isabel Germán Mancebo

    2012-12-01

    Full Text Available Algunos de los delitos contra la seguridad vial en España tienen asignada la pena de trabajos en beneficio de la comunidad (TBC. Y en la práctica se han percibido problemas en su implementación, entre otros motivos por el aumento de la comisión de los delitos de tránsito y la escasez de puestos de trabajo social para poder llevar a cabo los trabajos comunitarios. Tanto la reciente modificación del Código Penal, como de la normativa reguladora de esta sanción, permite desarrollar los TBC por medio de la realización de talleres. En este artículo se presenta la experiencia-modelo piloto de los talleres de seguridad vial que dan contenido a la pena de TBC, como alternativa a la pena privativa de libertad, lo que resulta de especial interés al ser una de las primeras experiencias de esta naturaleza en España. Para ello se describen los talleres desarrollados, mensualmente, durante el año 2010, a saber: su primer año de funcionamiento en la provincia de Gipuzkoa (España, detallando su estructura, dinámica y tareas -tanto formativas como de utilidad pública- que realizaron los penados. La implementación de estos talleres ha paliado las deficiencias percibidas en la aplicación de la pena de TBC, dotándola de contenido, y superando así las críticas a las que esta sanción se había visto expuesta. Los talleres de seguridad vial responden de forma efectiva al papel preventivo que se le ha otorgado a este tipo de sanciones en el ámbito de la seguridad vial.

  13. Inventarios viales y categorización de la red vial en estudios de Ingeniería de Tránsito y Transporte

    Directory of Open Access Journals (Sweden)

    Julián Rodrigo Quintero

    2011-11-01

    Full Text Available Se presentan las principales consideraciones y los aspectos técnicos fundamentales de la elaboración de Inventarios Viales y la Categorización de la Red Vial, aplicadas a la realización de estudios de ingeniería de tránsito y transporte. Se exponen los aspectos generales relacionados con la elaboración de los inventarios de infraestructura vial, de señalización y dispositivos de control, de estacionamientos, de paraderos y de rutas de transporte público colectivo urbano de pasajeros, como una herramienta práctica para complementar los procedimientos de campo y optimizar los procesos y análisis de resultados orientados a identificar, caracterizar y cuantificar las variables relacionadas con el desarrollo del fenómeno del tránsito y la actividad del transporte.

  14. Comparison of Acid Titration, Conductivity, Flame Photometry, ICP-MS, and Accelerated Lamellae Formation Techniques in Determining Glass Vial Quality.

    Science.gov (United States)

    Fujimori, Kiyoshi; Lee, Hans; Sloey, Christopher; Ricci, Margaret S; Wen, Zai-Qing; Phillips, Joseph; Nashed-Samuel, Yasser

    2016-01-01

    Certain types of glass vials used as primary containers for liquid formulations of biopharmaceutical drug products have been observed with delamination that produced small glass like flakes termed lamellae under certain conditions during storage. The cause of this delamination is in part related to the glass surface defects, which renders the vials susceptible to flaking, and lamellae are formed during the high-temperature melting and annealing used for vial fabrication and shaping. The current European Pharmacopoeia method to assess glass vial quality utilizes acid titration of vial extract pools to determine hydrolytic resistance or alkalinity. Four alternative techniques with improved throughput, convenience, and/or comprehension were examined by subjecting seven lots of vials to analysis by all techniques. The first three new techniques of conductivity, flame photometry, and inductively coupled plasma mass spectrometry measured the same sample pools as acid titration. All three showed good correlation with alkalinity: conductivity (R(2) = 0.9951), flame photometry sodium (R(2) = 0.9895), and several elements by inductively coupled plasma mass spectrometry [(sodium (R(2) = 0.9869), boron (R(2) = 0.9796), silicon (R(2) = 0.9426), total (R(2) = 0.9639)]. The fourth technique processed the vials under conditions that promote delamination, termed accelerated lamellae formation, and then inspected those vials visually for lamellae. The visual inspection results without the lot with different processing condition correlated well with alkalinity (R(2) = 0.9474). Due to vial processing differences affecting alkalinity measurements and delamination propensity differently, the ratio of silicon and sodium measurements from inductively coupled plasma mass spectrometry was the most informative technique to assess overall vial quality and vial propensity for lamellae formation. The other techniques of conductivity, flame photometry, and accelerated lamellae formation

  15. A scale?down mimic for mapping the process performance of centrifugation, depth and sterile filtration

    OpenAIRE

    2016-01-01

    ABSTRACT In the production of biopharmaceuticals disk?stack centrifugation is widely used as a harvest step for the removal of cells and cellular debris. Depth filters followed by sterile filters are often then employed to remove residual solids remaining in the centrate. Process development of centrifugation is usually conducted at pilot?scale so as to mimic the commercial scale equipment but this method requires large quantities of cell culture and significant levels of effort for successfu...

  16. Centrifuge facilities at Technical University of Denmark

    DEFF Research Database (Denmark)

    Leth, Caspar Thrane; Krogsbøll, Anette Susanne; Hededal, Ole

    2008-01-01

    The geotechnical group at the Danish Technical University (DTU) operates a geotechnical beam centrifuge. The centrifuge was build in 1976 and has been upgraded through the years, latest with onboard data and control systems. The centrifuge concept involves an increased gravity field in which...... the physical model is placed and tested. The capabilities of the centrifuge at DTU makes it possible to obtain a scale factor of 75-85 in the tests which equals a soil volume in prototype scale of ø40m and a depth of 36 m. The centrifuge facilities at DTU have through the years been used for testing various...... geotechnical issues, such as suction anchors, tension piles in clay, active earth pressures on sheet piles and group effects for lateral loaded piles. The paper describes physical modelling in general, the centrifuge, present setups and shows samples of obtained results....

  17. Microfabrication of screen-printed nanoliter vials with embedded surface-modified electrodes.

    Science.gov (United States)

    Lenihan, Jeffrey S; Ball, J Christopher; Gavalas, Vasilis G; Lumpp, Janet K; Hines, John; Daunert, Sylvia; Bachas, Leonidas G

    2007-01-01

    A self-contained ion-selective sensing system within a nanoliter-volume vial has been developed by integrating screen printing, laser ablation, and molecular imprinting techniques. Screen printing and laser ablation are used in tandem to fabricate nanoliter-volume vials with carbon and Ag/AgCl ring electrodes embedded in the sidewalls. Using multisweep cyclic voltammetry, the surface of the carbon electrode can be modified with a polypyrrole film. By polymerizing pyrrole in the presence of nitrate, pores complementary to the nitrate anion in size, shape, and charge distribution are formed in the resulting film. Electrochemical cells modified with this nitrate-imprinted polypyrrole film show a near-Nernstian response to nitrate, and excellent reproducibility. The integration of molecular recognition and electrochemical response in the nanoliter vials is demonstrated by the detection of as little as 0.36 ng nitrate in nanoliter-volume samples. The integration of tailored molecular recognition within nanoliter vials via established fabrication and imprinting protocols should result in a number of nanosensor devices with applications in BioMEMS and micro total analysis systems.

  18. Evaluation of Glass Delamination Risk in Pharmaceutical 10 mL/10R Vials.

    Science.gov (United States)

    Ditter, Dominique; Nieto, Alejandra; Mahler, Hanns-Christian; Roehl, Holger; Wahl, Michael; Huwyler, Joerg; Allmendinger, Andrea

    2017-10-06

    Glass delamination is characterized by the dissociation of glass flakes from the glass surface. Since glass delamination is time dependent, 5 vial types were investigated to assess delamination under accelerated stress conditions published as quick tests in literature and compared to stress testing recommended per United States Pharmacopoeia . A broad panel of analytical techniques was employed to test the solution for visible/subvisible particles and leachables and characterize topography and composition of the surface. The vial types showed significant differences in surface durability when applying the same stress conditions. An increase in glass leachables and change in topography were shown for uncoated vials. An indication for an elevated delamination risk was confirmed for Expansion 33 vials only by the compiled analytical data set including particle assessment and change in elemental composition of the near glass surface investigated by dynamic secondary ion mass spectrometry. The delamination test protocols differ in test solution, handling, and time. Before choosing the most appropriate protocol to predict delamination propensity and mimic real-time conditions, long-term storage data are needed. A combination of analytical techniques to study the risk for long-term corrosion of glass is highly recommended covering the 3 aspects: visible/subvisible particle assessment, solution analysis, and surface characterization. Copyright © 2017 American Pharmacists Association®. Published by Elsevier Inc. All rights reserved.

  19. Hacia el desarrollo sostenible en la seguridad vial : el caso holandés.

    NARCIS (Netherlands)

    Wegman, F.C.M.

    1999-01-01

    En esta ponencia, se hace un estudio general sobre la Seguridad Vial en los Países Bajos, mostrando la evolución del indice de accidentes. Se indican cuales son los objetivos fijados por el Gobierno neerlandés y la estrategia a seguir desde el punto de vista político. Aparece el concepto de

  20. Supervisando la seguridad vial en el Perú Supervising road safety in Peru

    Directory of Open Access Journals (Sweden)

    Freddy Sagástegui

    2010-06-01

    Full Text Available En este artículo se describe algunos problemas en seguridad vial que la Defensoría del Pueblo del Perú, en su trabajo como ente supervisor de la administración pública ha detectado, entre esos problemas se mencionan a: la escasa y mala elaboración de estadísticas de accidentes de tránsito; la inconsistencia del Consejo Nacional de Seguridad Vial y la irresponsabilidad de los gobiernos regionales y locales por su falta de aplicación del Plan Nacional de Seguridad Vial. Ante ello, la Defensoría del Pueblo sugiere que el Estado desarrolle un sistema estadístico riguroso, que fortalezca al Consejo Nacional de Seguridad Vial y que los diferentes sectores del Estado desarrollen el mencionado Plan Nacional.In this article some problems in road safety are described, which have been detected by the Ombudsman of Peru, as part of its role of public administration supervisor, amongst these problems we mention: lack of and inadequate elaboration of the statistics on road traffic accidents, the inconsistency of the National Council for Road Security and the lack of responsibility of the local and regional governments reflected by the lack of application of the National Plan of Road Safety. Facing this, the Ombudsman suggests that the State develops a rigorous statistical system, strengthens the National Council of Road Safety and that the different sectors of the government develop the mentioned National Plan.

  1. Influence of storage vial material on measurement of organophosphate flame retardant metabolites in urine.

    Science.gov (United States)

    Carignan, Courtney C; Butt, Craig M; Stapleton, Heather M; Meeker, John D; Minguez-Alarcón, Lidia; Williams, Paige L; Hauser, Russ

    2017-08-01

    Use of organophosphate flame retardants (PFRs) has increased over the past decade with the phase out of polybrominated diphenyl ethers. Urinary metabolites of PFRs are used as biomarkers of exposure in epidemiologic research, which typically uses samples collected and stored in polypropylene plastic cryovials. However, a small study suggested that the storage vial material may influence reported concentrations. Therefore, we aimed to examine the influence of the storage vial material on analytical measurement of PFR urinary metabolites. Using urine samples collected from participants in the Environment and Reproductive Health (EARTH) Study, we analyzed the PFR metabolites in duplicate aliquots that were stored in glass and plastic vials (n = 31 pairs). Bis(1,3-dichloro-2-propyl) phosphate (BDCIPP), diphenyl phosphate (DPHP) and isopropyl-phenyl phenyl phosphate (ip-PPP) were detected in 98%, 97% and 87% of duplicates. We observed high correlations between glass-plastic duplicates for BDCIPP (rs = 0.95), DPHP (rs = 0.79) and ip-PPP (rs = 0.82) (p polypropylene plastic cryovials may result in slightly reduced concentrations of urinary ip-PPP relative to storage in glass vials and future research should seek to increase the sample size, reduce background variability and consider the material of the urine collection cup. Copyright © 2017 Elsevier Ltd. All rights reserved.

  2. Protect Patients by Using Single- and Multi-Dose Vials Correctly

    Centers for Disease Control (CDC) Podcasts

    2014-07-10

    CDC’s One & Only Campaign urges healthcare providers to recognize the differences between single-dose and multi-dose vials, and to understand appropriate use of each container type.  Created: 7/10/2014 by National Center for Emerging and Zoonotic Infectious Diseases (NCEZID).   Date Released: 7/10/2014.

  3. Aluminum elution and precipitation in glass vials: effect of pH and buffer species.

    Science.gov (United States)

    Ogawa, Toru; Miyajima, Makoto; Wakiyama, Naoki; Terada, Katsuhide

    2015-02-01

    Inorganic extractables from glass vials may cause particle formation in the drug solution. In this study, the ability of eluting Al ion from borosilicate glass vials, and tendencies of precipitation containing Al were investigated using various pHs of phosphate, citrate, acetate and histidine buffer. Through heating, all of the buffers showed that Si and Al were eluted from glass vials in ratios almost the same as the composition of borosilicate glass, and the amounts of Al and Si from various buffer solutions at pH 7 were in the following order: citrate > phosphate > acetate > histidine. In addition, during storage after heating, the Al concentration at certain pHs of phosphate and acetate buffer solution decreased, suggesting the formation of particles containing Al. In citrate buffer, Al did not decrease in spite of the high elution amount. Considering that the solubility profile of aluminum oxide and the Al eluting profile of borosilicate glass were different, it is speculated that Al ion may be forced to leach into the buffer solution according to Si elution on the surface of glass vials. When Al ions were added to the buffer solutions, phosphate, acetate and histidine buffer showed a decrease of Al concentration during storage at a neutral range of pHs, indicating the formation of particles containing Al. In conclusion, it is suggested that phosphate buffer solution has higher possibility of forming particles containing Al than other buffer solutions.

  4. Measurement of shrinkage and cracking in lyophilized amorphous cakes, part 3: hydrophobic vials and the question of adhesion.

    Science.gov (United States)

    Ullrich, Sabine; Seyferth, Stefan; Lee, Geoffrey

    2015-06-01

    The importance of cake adhesion to the inside vial wall during lyophilization of amorphous trehalose cakes was determined by using hydrophobized vials. The degrees of cake shrinkage and cracking were determined independently by photographic imaging of the cake top surface in a dark cell. Additionally, measurements with microcomputed tomography were performed. Adhesion is found to be a determining factor in both cake shrinkage and cracking. The correlation between cake detachment from the vial inner wall and trehalose concentration indicates that adhesion of the frozen solute phase is a determining factor in shrinkage. The hydrophobized vials give reduced cracking at trehalose concentrations of up to 15%. The reduced wetting of the hydrophobized inside vial wall gives a planar cake topography with a uniform distribution of cracks within the cake. © 2015 Wiley Periodicals, Inc. and the American Pharmacists Association.

  5. Impact of changing the measles vaccine vial size on Niger's vaccine supply chain: a computational model

    Directory of Open Access Journals (Sweden)

    Kenea Hailu

    2011-06-01

    Full Text Available Abstract Background Many countries, such as Niger, are considering changing their vaccine vial size presentation and may want to evaluate the subsequent impact on their supply chains, the series of steps required to get vaccines from their manufacturers to patients. The measles vaccine is particularly important in Niger, a country prone to measles outbreaks. Methods We developed a detailed discrete event simulation model of the vaccine supply chain representing every vaccine, storage location, refrigerator, freezer, and transport device (e.g., cold trucks, 4 × 4 trucks, and vaccine carriers in the Niger Expanded Programme on Immunization (EPI. Experiments simulated the impact of replacing the 10-dose measles vial size with 5-dose, 2-dose and 1-dose vial sizes. Results Switching from the 10-dose to the 5-dose, 2-dose and 1-dose vial sizes decreased the average availability of EPI vaccines for arriving patients from 83% to 82%, 81% and 78%, respectively for a 100% target population size. The switches also changed transport vehicle's utilization from a mean of 58% (range: 4-164% to means of 59% (range: 4-164%, 62% (range: 4-175%, and 67% (range: 5-192%, respectively, between the regional and district stores, and from a mean of 160% (range: 83-300% to means of 161% (range: 82-322%, 175% (range: 78-344%, and 198% (range: 88-402%, respectively, between the district to integrated health centres (IHC. The switch also changed district level storage utilization from a mean of 65% to means of 64%, 66% and 68% (range for all scenarios: 3-100%. Finally, accounting for vaccine administration, wastage, and disposal, replacing the 10-dose vial with the 5 or 1-dose vials would increase the cost per immunized patient from $0.47US to $0.71US and $1.26US, respectively. Conclusions The switch from the 10-dose measles vaccines to smaller vial sizes could overwhelm the capacities of many storage facilities and transport vehicles as well as increase the cost per

  6. Iohexol in patients undergoing urography: a comparison of polypropylene containers (Unique Soft Pack) and glass vials.

    Science.gov (United States)

    Tveit, K; Dardenne, A N; Svihus, R; Fairhurst, J; Jenssen, G; Lemaitre, L; Grellet, J; Brekke, O; Skinningsrud, K

    1995-01-01

    The purpose of the present phase IV multicentre trial was to evaluate general patient tolerance to Omnipaque 350 mgI/ml (iohexol) supplied in polypropylene containers compared to that of the same product supplied in routinely used glass vials, with emphasis on allergy-like adverse events. Polypropylene is a pure plastic material with practically no additives, and has been tested in vitro as a contrast medium packaging material for several years. Handling of these containers is easier and safer than handling of glass vials. Iohexol was administered to 1481 patients undergoing urography (741 patients in the glass vial group, 740 in the polypropylene container group), all of whom successfully participated in the trial. Six centres, representing four European countries, participated. Patients were randomized to receive iohexol from either polypropylene containers or traditional glass vials according to a double blind, parallel design. Pre-established inclusion and pre-admission exclusion criteria were followed, as well as routine procedures for preparation of the patients and conduct of the urography examinations at each hospital. Patient tolerance was assessed by recording all adverse events experienced over a period of up to 1 h after the procedure. Allergy-like events were defined as coughing, sneezing, nausea, vomiting, urticaria or itching. No adverse events were experienced by 56.5% of the patients in the glass vial group, nor by 58.0% of those in the polypropylene group. Discomfort (mainly a sensation of warmth) was reported by 39.4% and 38.6% of the patients, and adverse events other than discomfort by 7.4% and 5.9% of the patients, respectively. There seemed to be a correlation between the speed of injection and the frequency of discomfort (an increase with increasing speed), both of which varied a lot between centres. There was no significant difference in the incidence of allergy-like events between the two groups. Such reactions were seen in 2.0% of

  7. Impact of changing the measles vaccine vial size on Niger's vaccine supply chain: a computational model.

    Science.gov (United States)

    Assi, Tina-Marie; Brown, Shawn T; Djibo, Ali; Norman, Bryan A; Rajgopal, Jayant; Welling, Joel S; Chen, Sheng-I; Bailey, Rachel R; Kone, Souleymane; Kenea, Hailu; Connor, Diana L; Wateska, Angela R; Jana, Anirban; Wisniewski, Stephen R; Van Panhuis, Willem G; Burke, Donald S; Lee, Bruce Y

    2011-06-02

    Many countries, such as Niger, are considering changing their vaccine vial size presentation and may want to evaluate the subsequent impact on their supply chains, the series of steps required to get vaccines from their manufacturers to patients. The measles vaccine is particularly important in Niger, a country prone to measles outbreaks. We developed a detailed discrete event simulation model of the vaccine supply chain representing every vaccine, storage location, refrigerator, freezer, and transport device (e.g., cold trucks, 4 × 4 trucks, and vaccine carriers) in the Niger Expanded Programme on Immunization (EPI). Experiments simulated the impact of replacing the 10-dose measles vial size with 5-dose, 2-dose and 1-dose vial sizes. Switching from the 10-dose to the 5-dose, 2-dose and 1-dose vial sizes decreased the average availability of EPI vaccines for arriving patients from 83% to 82%, 81% and 78%, respectively for a 100% target population size. The switches also changed transport vehicle's utilization from a mean of 58% (range: 4-164%) to means of 59% (range: 4-164%), 62% (range: 4-175%), and 67% (range: 5-192%), respectively, between the regional and district stores, and from a mean of 160% (range: 83-300%) to means of 161% (range: 82-322%), 175% (range: 78-344%), and 198% (range: 88-402%), respectively, between the district to integrated health centres (IHC). The switch also changed district level storage utilization from a mean of 65% to means of 64%, 66% and 68% (range for all scenarios: 3-100%). Finally, accounting for vaccine administration, wastage, and disposal, replacing the 10-dose vial with the 5 or 1-dose vials would increase the cost per immunized patient from $0.47US to $0.71US and $1.26US, respectively. The switch from the 10-dose measles vaccines to smaller vial sizes could overwhelm the capacities of many storage facilities and transport vehicles as well as increase the cost per vaccinated child.

  8. Centrifugal separators and related devices and methods

    Energy Technology Data Exchange (ETDEWEB)

    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.

  9. Extraction technique for the determination of oxygen-18 in water using preevacuated glass vials

    Science.gov (United States)

    Socki, R. A.; Karlsson, H. R.; Gibson, E. K. Jr; Gibson EK, J. r. (Principal Investigator)

    1992-01-01

    The need for a rapid, inexpensive technique for routine 18O/16O extraction from water has arisen recently through applications in the medical sciences and in hydrology. The traditional experimental technique for determining the oxygen isotope composition of water, the CO2-H2O equilibration method, is tedious, time consuming, and involves the use of custom-made glass apparatus. Furthermore, because of potential memory effects from one sample to the next, the glassware needs to be thoroughly cleaned between runs. A few attempts have been made to improve upon the method. Attempts to analyze water directly in the source of the mass spectrometer produced large memory effects and questionable results. Commercially available apparatus for automated extraction of 18O/16O from water is generally prohibitively expensive and often is designed to interface only with the manufacturer's own mass spectrometer. The method described in this paper utilizes inexpensive, off-the-shelf, preevacuated, glass vials. Preevacuated vials have been used by others for the isotopic analysis of breath CO2 and are well tested. The vials can be purchased in bulk from scientific apparatus suppliers at a relatively low cost. These are coupled with a simplified extraction line consisting of a stainless steel syringe needle and a glass cold trap. Vials are filled with CO2 and H2O and shaken in a constant-temperature water bath for at least 90 min. Since the vials are discarded after use, no cleaning is necessary, essentially eliminating any memory effect. Reproducibility is generally better than +/- 0.05%. The only reagents required are gaseous CO2 for equilibration, a dry ice/alcohol mixture for trapping water, and liquid nitrogen for transferring the CO2.

  10. Isolation of exosomes by differential centrifugation: Theoretical analysis of a commonly used protocol

    Science.gov (United States)

    Livshts, Mikhail A.; Khomyakova, Elena; Evtushenko, Evgeniy G.; Lazarev, Vassili N.; Kulemin, Nikolay A.; Semina, Svetlana E.; Generozov, Edward V.; Govorun, Vadim M.

    2015-11-01

    Exosomes, small (40-100 nm) extracellular membranous vesicles, attract enormous research interest because they are carriers of disease markers and a prospective delivery system for therapeutic agents. Differential centrifugation, the prevalent method of exosome isolation, frequently produces dissimilar and improper results because of the faulty practice of using a common centrifugation protocol with different rotors. Moreover, as recommended by suppliers, adjusting the centrifugation duration according to rotor K-factors does not work for “fixed-angle” rotors. For both types of rotors - “swinging bucket” and “fixed-angle” - we express the theoretically expected proportion of pelleted vesicles of a given size and the “cut-off” size of completely sedimented vesicles as dependent on the centrifugation force and duration and the sedimentation path-lengths. The proper centrifugation conditions can be selected using relatively simple theoretical estimates of the “cut-off” sizes of vesicles. Experimental verification on exosomes isolated from HT29 cell culture supernatant confirmed the main theoretical statements. Measured by the nanoparticle tracking analysis (NTA) technique, the concentration and size distribution of the vesicles after centrifugation agree with those theoretically expected. To simplify this “cut-off”-size-based adjustment of centrifugation protocol for any rotor, we developed a web-calculator.

  11. Operation of Droplet-Microfluidic Devices with a Lab Centrifuge

    Directory of Open Access Journals (Sweden)

    Noorsher Ahmed

    2016-09-01

    Full Text Available Microfluidic devices are valuable for a variety of biotechnology applications, such as synthesizing biochemical libraries, screening enzymes, and analyzing single cells. However, normally, the devices are controlled using specialized pumps, which require expert knowledge to operate. Here, we demonstrate operation of poly(dimethylsiloxane devices without pumps. We build a scaffold that holds the device and reagents to be infused in a format that can be inserted into a 50 mL falcon tube and spun in a common lab centrifuge. By controlling the device design and centrifuge spin speed, we infuse the reagents at controlled flow rates. We demonstrate the encapsulation and culture of clonal colonies of red and green Escherichia coli in droplets seeded from single cells.

  12. Isolation of Intact Mitochondria from Skeletal Muscle by Differential Centrifugation for High-resolution Respirometry Measurements.

    Science.gov (United States)

    Djafarzadeh, Siamak; Jakob, Stephan Mathias

    2017-03-08

    Mitochondria are involved in cellular energy metabolism and use oxygen to produce energy in the form of adenosine triphosphate (ATP). Differential centrifugation at low- and high-speed is commonly used to isolate mitochondria from tissues and cultured cells. Crude mitochondrial fractions obtained by differential centrifugation are used for respirometry measurements. The differential centrifugation technique is based on the separation of organelles according to their size and sedimentation velocity. The isolation of mitochondria is performed immediately after tissue harvesting. The tissue is immersed in an ice-cold homogenization medium, minced using scissors and homogenized in a glass homogenizer with a loose-fitting pestle. The differential centrifugation technique is efficient, fast and inexpensive and the mitochondria obtained by differential centrifugation are pure enough for respirometry assays. Some of the limitations and disadvantages of isolated mitochondria, based on differential centrifugation, are that the mitochondria can be damaged during the homogenization and isolation procedure and that large amounts of the tissue biopsy or cultured cells are required for the mitochondrial isolation.

  13. Rotor for a pyrolysis centrifuge reactor

    DEFF Research Database (Denmark)

    2015-01-01

    The present invention relates to a rotor for a pyrolysis centrifuge reactor, said rotor comprising a rotor body having a longitudinal centre axis, and at least one pivotally mounted blade being adapted to pivot around a pivot axis under rotation of the rotor body around the longitudinal centre axis....... Moreover, the present invention relates to a pyrolysis centrifuge reactor applying such a rotor....

  14. Astronaut Gordon Cooper in centrifuge for tests

    Science.gov (United States)

    1963-01-01

    Astronaut L. Gordon Cooper, prime pilot for the Mercury-Atlas 9 mission, is strapped into the gondola while undergoing tests in the centrifuge at the Naval Air Development Center, Johnsville, Pennsylvania. The centrifuge is used to investigate by simulation the pilot's capability to control the vehicle during the actual flight in its booster and reentry profile.

  15. Centrifuge modelling of offshore monopile foundation

    DEFF Research Database (Denmark)

    Klinkvort, Rasmus Tofte; Hededal, Ole

    2010-01-01

    centrifuge tests on a laterally loaded monopile in dry sand. The prototype dimension of the piles was modelled to a diameter of 1 meter and penetration depth on 6 meter. The test series were designed in order to investigate the scaling laws in the centrifuge both for monotonic and cyclic loading...

  16. Consequences of not relieving negative internal pressure of a medication vial: A survey and simulation study.

    Science.gov (United States)

    Fujimoto, Hiroko; Irie, Tomoya; Kawakami, Hiromasa; Miyashita, Tetsuya; Goto, Takahisa

    2017-02-01

    The glass vial of acetaminophen as an intravenous preparation (Acelio®, Terumo, Japan) has a strong internal negative pressure. The aim of our study was to determine if this negative pressure could result in medication administration errors if not released prior to connecting to the IV set. Questionnaire survey and simulation study. University hospital and its affiliated hospitals. Fifty-two anesthesiologists in 6 different hospitals in Yokohama. A questionnaire on current practice was sent to the subjects. The authors then first calculated the internal pressure of the Acelio® vial followed by a simulation set-up. This set-up measured the amount of saline that could be aspirated from a syringe loaded on a syringe pump connected via a secondary IV line when the Acelio® vial was attached to the primary line without prior release of the internal pressure. The volume of aspiration was tested with two syringe sizes and with a fully open IV clamp vs partially closed. Twenty-nine (56.9%) of 51 anesthesiologists who responded to the survey had connected the Acelio® vial at least once without releasing the internal negative pressure, and 21 experienced consequences such as backflow of the venous blood. The pressure inside the Acelio® vial was 81.8±19.6Torr. With the clamp of the simulated IV line fully open, the amount of saline aspirated before the alarm of the syringe pump went off was 1.5±0.1ml and 3.2±0.3ml when 20ml and 50ml syringes were used, respectively. When the clamp was partially closed to allow 2 drops per second, this value was 1.3±0.1ml and 2.3±0.1ml, respectively. After removing the plunger from the holder of the syringe pump, an additional 7ml (clamp partially closed) or 15-18ml (clamp fully open) was aspirated in the subsequent 1min. A considerable number of anesthesiologists experienced consequences caused by the negative pressure inside the Acelio® vial. This can also cause aspiration of the contents of the syringe pump. Copyright © 2016

  17. Centrifugal and axial compressor control

    CERN Document Server

    McMillan, Gregory K

    2009-01-01

    Control engineers, mechanical engineers and mechanical technicians will learn how to select the proper control systems for axial and centrifugal compressors for proper throughput and surge control, with a particular emphasis on surge control. Readers will learn to understand the importance of transmitter speed, digital controller sample time, and control valve stroking time in helping to prevent surge. Engineers and technicians will find this book to be a highly valuable guide on compressor control schemes and the importance of mitigating costly and sometimes catastrophic surge problems. It can be used as a self-tutorial guide or in the classroom with the book's helpful end-of-chapter questions and exercises and sections for keeping notes.

  18. Centrifuges in gravitational physiology research

    Science.gov (United States)

    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.

  19. Vial position in the determination of chlorophenols in water by solid phase microextraction.

    Science.gov (United States)

    Portillo, M; Prohibas, N; Salvadó, V; Simonet, B M

    2006-01-20

    The extraction of chlorophenol from water by headspace solid phase microextraction (HS-SPME) in vials located both vertically and horizontally is compared. The results obtained show that kinetic parameters are clearly affected by how the vial is placed in the analysis of semivolatile compounds. Extraction time for reach the equilibrium was three times lower in the horizontal configuration. An on-line extraction unit coupled to a continuous flow system is used to analyse unmodified ground water samples. In order to increase the high throughput, the analysis time is reduced and the sensitivity increased by making the extraction simultaneously with two fibres. The proposed method is applied to the analysis of spiked river water samples. The precision expressed as relative standard deviation ranges from 3.5 to 4.8%, and the recoveries from 94 to 105%.

  20. Effect of Air Space in Storage Vials on Motility of Spermatozoa in Chilled Buck Semen

    Directory of Open Access Journals (Sweden)

    Magnus Paul K and Lali F Anand 1

    Full Text Available This study was conducted in order to find out the effect of air space on the top of glass vial in which semen is stored, on the motility of spermatozoa. 45 samples collected from two bucks over a span of 6 months were used for experiment. Goat milk extender was the diluent used. Two ml each of diluted semen after noting their initial motility was stored in 2 ml and 5 ml vials. Samples were stored at 5°C and motility of spermatozoa noted at 24 and 48 hours. Semen without air space was found to preserve the motility better than semen with air space on 24 and 48 hours of incubation. This could be better attributed to reactive oxygen species production by the spermatozoa, but further investigation is needed in this aspect to confirm it. [Veterinary World 2010; 3(9.000: 421-423

  1. Quality of bevacizumab (Avastin® repacked in single-use glass vials for intravitreal administration

    Directory of Open Access Journals (Sweden)

    Michelle A. A. Sugimoto

    Full Text Available ABSTRACT Purpose: Avastin® (bevacizumab is an anti-vascular endothelial growth factor (VEGF monoclonal antibody given as an off-label drug by intravitreal administration for treatment of ocular diseases. The drug's clinical application and its cost-benefit profile has generated demand for its division into single-use vials to meet the low volume and low-cost doses necessary for intraocular administration. However, the safety of compounding the drug in single-use vials is still under discussion. In this study, the stability and efficacy of Avastin® repacked in individual single-use glass vials and glass ampoules by external compounding pharmacies were evaluated. Methods: Polyacrylamide gel electrophoresis (PAGE, size-exclusion chromatography (SEC, dynamic light scattering (DLS, and turbidimetry were selected to detect the formation of aggregates of various sizes. Changes in bevacizumab biological efficacy were investigated by using an enzyme-linked immunosorbent assay (ELISA. Results: Repacked and reference bevacizumab showed similar results when analyzed by PAGE. By SEC, a slight increase in high molecular weight aggregates and a reduction in bevacizumab monomers were observed in the products of the three compounding pharmacies relative to those in the reference bevacizumab. A comparison of repacked and reference SEC chromatograms showed that the mean monomer loss was ≤1% for all compounding pharmacies. Protein aggregates in the nanometer- and micrometer-size ranges were not detected by DLS and turbidimetry. In the efficacy assay, the biological function of repacked bevacizumab was preserved, with <3% loss of VEGF binding capacity relative to that of the reference. Conclusion: The results showed that bevacizumab remained stable after compounding in ampoules and single-use glass vials; no significant aggregation, fragmentation, or loss of biological activity was observed.

  2. Centrifuge workers study. Phase II, completion report

    Energy Technology Data Exchange (ETDEWEB)

    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.

  3. Laser Scanner Como Sistema de Detección de Entornos Viales

    Directory of Open Access Journals (Sweden)

    F. García

    2011-01-01

    Full Text Available Resumen: Los últimos avances en seguridad vial, con sistemas cada vez más complejos, requieren de los más modernos sistemas de adquisición de información. La naturaleza misma del problema requiere sensores capaces de proveer información fiable para tareas complejas y exigentes. Los escáneres láser (LIDAR han demostrado ser una familia de sensores altamente fiable, por lo que durante los últimos años los esfuerzos dedicados a investigar posibles aplicaciones viales han ido en aumento. De esta forma, es cada vez más frecuente observar sistemas de ayuda a la conducción (ADAS con este tipo de dispositivos que proveen de información del entorno necesaria para realizar tareas complejas como deteccián y prediccián de situaciones peligrosas. En el presente trabajo, dos sistemas LIDAR han sido probados para comprobar sus capacidades reales en entornos viales. En segundo término, se propone una aplicación que hace uso de las capacidades de dichos sensores para la detección y clasificación de obstaculos en entornos viarios. Palabras clave: sensores, procesamiento de senales, sistemas reales, vehiculos, algoritmos de deteccion

  4. Use of soft sensors to monitor a pharmaceuticals freeze-drying process in vials.

    Science.gov (United States)

    Bosca, Serena; Barresi, Antonello A; Fissore, Davide

    2014-03-01

    This paper presents a soft sensor that can be effectively used for in-line monitoring of the primary drying step of a pharmaceuticals freeze-drying process in vials. Process modeling and product temperature measurements are used to estimate the residual amount of ice in the vial and the heat transfer coefficient from the shelf to the product in the vial. The resistance of the dried cake to vapor flow is determined through the heat balance equation at the interface of sublimation. Mathematical simulation and experimental tests have been carried out to validate the estimations provided by the soft sensor. Accurate estimations of the dynamics of the product until the end of primary drying are obtained, as well as of the heat and mass transfer coefficients, even in the case of a highly non-uniform batch. The reduction in the number of variables directly estimated by the soft sensor allows increasing the robustness of the tool with respect to other sensors presented in the literature. The proposed soft sensor is thus effective for process monitoring and it allows using model-based tools for cycle development in lab-scale units, where thermocouples are usually available, and for process monitoring in industrial-scale freeze-dryers, in case wireless sensors are used.

  5. The study of vial and cocktail for tritium radioactivity analysis of rain water by liquid scintillation counter

    Energy Technology Data Exchange (ETDEWEB)

    Noh, Sung Jin; Kim, Hyo Jin; Kim, Hyun; Lee, Man Woo; Jeong, Dong Hyeok; Yang, Kwang Mo; Kang, Yeong Rok [Research Center, Dongnam Institute of Radiological and Medical Sciences, Busan (Korea, Republic of); Nam, Sang Hee [Dept. of Biomedical Engineering, Inje University, Gimhae (Korea, Republic of)

    2015-10-15

    Even though the current method for tritium (3H) analysis is routine, for the case of the low level of tritium in the environment, special conditions have to be fulfilled in order to obtain accurate and reliable tritium measurements. There are very little comparative data concerning commercial scintillating cocktails. The best cocktails for measuring tritium are those based on benzene derived solvent, and the worse cocktails are those which have complex chemical composition or contain too small concentration of scintillators. The aim of study was to investigate various vials and cocktails by comparison with the combination of few different scintillation cocktails and vials in our routine measurements according to count, efficiency, and the figure of merit (FOM). The comparison of three types of vials with scintillation cocktails for tritium activity analysis of rain water shows that glass vials have higher count rates and HiSafe 3 cocktails have lower FOM.

  6. Fault Detection and Isolation in Centrifugal Pumps

    DEFF Research Database (Denmark)

    Kallesøe, Carsten

    Centrifugal pumps are used in a variety of different applications, such as water supply, wastewater, and different industrial applications. Some pump installations are crucial for the applications to work. Failures can lead to substantial economic losses and can influence the life of many people...... is placed. The topic of this work is Fault Detection and Identification in centrifugal pumps. Different approaches are developed with special focus on robustness. Robustness with respect to disturbances, unknown parts of the system, and parameter variations are considered. All developed algorithms...... are tested on an industrial test setup, showing the usability of the algorithms on a real centrifugal pump....

  7. Turbidity removal by centrifugal microfiltration

    Directory of Open Access Journals (Sweden)

    Tim C. Keener

    2017-03-01

    Full Text Available Water turbidity is an important characteristic of surface waters and wastewater treatment plant effluents as well as a key indicator of water quality. Turbidity is the lack of clarity of water caused by microalgae and other particles that attenuates light. The cost of clarifying water can be high. This is primarily due to the physical and chemical steps that must be taken to remove the extremely small entrained particles and colloidal substances that cause high turbidity, and the large amounts of water that generally must be process for such small masses of entrained materials. This paper discusses the results of a series of experiments of a potentially new method of clarifying water by incorporating microfiltration through a high throughput filter operating under a centrifugal force. The results have shown that significant reductions in turbidity can be achieved at relatively high water flux values through a commercially available filter. This indicates the potential of the technology as a water clarifying method by means of this low energy separation device.

  8. Cell structure and percent viability by a slide centrifuge technique.

    Science.gov (United States)

    Fitzgerald, M G; Hosking, C S

    1982-01-01

    It was found that a slide centrifuge (Cytospin) preparation of a cell suspension allowed a reliable assessment of not only cell structure but also the percentage of non-viable cells. The non-viable cells appeared as "smear" cells and paralleled in number the cells taking up trypan blue. Direct experiment showed the unstained viable cells in a trypan blue cell suspension remained intact in a Cytospin preparation while the cells taking up trypan blue were the "smear" cells. The non-viability of the "smear" cells was confirmed by their inability to survive in culture. Images PMID:7040483

  9. Histoplasma capsulatum fungemia in patients with acquired immunodeficiency syndrome: detection by lysis-centrifugation blood-culturing technique Fungemia por Histoplasma capsulatum em pacientes com a síndrome da imunodeficiência adquirida: detecção através da técnica de hemocultivo por lise-centrifugação

    Directory of Open Access Journals (Sweden)

    Flávio de Mattos Oliveira

    2007-06-01

    Full Text Available Progressive disseminated histoplasmosis (PDH is an increasingly common cause of infection in patients with acquired immune deficiency syndrome (AIDS. We report 21 cases of PDH associated with AIDS diagnosed by lysis-centrifugation blood culture method. The most prevalent clinical findings were fever, weight loss, respiratory symptoms, and mucocutaneous lesions. Chest roentgenogram showed diffuse pulmonary infiltrates in 13 of 21 patients (62%. Brochoalveolar fluid has yelded positive culture in four patients only in medium with cycloheximide.Histoplasmose progressiva disseminada (HPD tem aumentado e é causa comum de infecção em pacientes com síndrome da imunodeficiência adquirida (Aids. Relatamos 21 casos de HPD associado com Aids diagnosticada pela técnica de hemocultivo por lise-centrifugação. Os achados clínicos mais prevalentes foram febre, perda de peso, sintomas respiratórios e lesões mucocutâneas. Raios X de tórax mostrou infiltrados pulmonares difusos em 13 dos 21 pacientes (62%. Amostras de lavado broncoalveolar foram positivos em apenas 4 pacientes através de meio com cicloheximida.

  10. Renal Response to Chronic Centrifugation in Rats

    Science.gov (United States)

    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.

  11. Centrifugal Separation of Antiprotons and Electrons

    CERN Document Server

    Gabrielse, G; McConnell, R; Richerme, P; Wrubel, J; Kalra, R; Novitski, E; Grzonka, D; Oelert, W; Sefzick, T; Zielinski, M; Borbely, J S; Fitzakerley, D; George, M C; Hessels, E A; Storry, C H; Weel, M; Mullers, A; Walz, J; Speck, A

    2010-01-01

    Centrifugal separation of antiprotons and electrons is observed, the first such demonstration with particles that cannot be laser cooled or optically imaged. The spatial separation takes place during the electron cooling of trapped antiprotons, the only method available to produce cryogenic antiprotons for precision tests of fundamental symmetries and for cold antihydrogen studies. The centrifugal separation suggests a new approach for isolating low energy antiprotons and for producing a controlled mixture of antiprotons and electrons.

  12. Agresividad vial en la población general Road-rage in the general population

    Directory of Open Access Journals (Sweden)

    Inmaculada Fierro

    2010-10-01

    Full Text Available Objetivos: Analizar la prevalencia y los factores sociodemográficos asociados con la agresividad vial en la población. Métodos: Se han realizado 2.500 entrevistas a la población de Castilla y León de entre 14 y 70 años de edad. Se evaluó la agresividad vial en el año previo a la realización de la encuesta utilizando un test de ocho preguntas. Resultados: El 31,1% refirió haber vivido alguna situación de agresividad vial en el último año, y el 26,8% en más de una ocasión. El 2,6% fueron agresores viales «graves». Entre los conductores, la probabilidad de experimentar agresividad vial aumenta a medida que aumentan los miles de kilómetros conducidos a la semana (odds ratio [OR]=1,52, es menor cuanto mayor es la edad del entrevistado (OR=0,975 y es mayor en los hombres (OR=1,287, en los que tienen estudios universitarios (OR=1,408 y en los que viven en localidades de más de 10.000 habitantes (OR=1,25. Conclusiones: Los datos del presente estudio muestran que la agresividad vial afecta a casi un tercio de la población general de Castilla y León, lo que justificaría la adopción de medidas para su prevención y reducción.Objective: To analyze the prevalence of road rage in the general population and the sociodemographic factors associated with this phenomenon. Methods: A total of 2,500 interviews were carried out in the population of Castile and Leon aged 14-70 years. Road rage was evaluated in the year prior to the survey using a test with eight questions. Results: One-third (31.1% of the interviewees reported they had experienced a situation involving road rage during the previous 12 months (26.8% on more than one occasion. Among these episodes, 2.6% involved "serious" aggressors. In drivers, the probability of experiencing road rage increased in line with the number of kilometers driven per week (odds ratio [OR]=1.52, decreased as the age of the driver increased (OR=0.975, and was highest in men (OR=1.287, university

  13. Stability of Procainamide Injection in Clear Glass Vials and Polyvinyl Chloride Bags.

    Science.gov (United States)

    Donnelly, Ronald F

    2017-11-01

    The objective of this study was to evaluate the chemical stability of procainamide hydrochloride, 100 mg/mL, when repackaged in clear glass vials or diluted to 3 mg/mL with normal saline and packaged in polyvinyl chloride (PVC) bags when stored at either 23°C and exposed to light (ETL) or 5°C and protected from light (PFL). Solutions were assayed using a stability-indicating high-performance liquid chromatography method. Samples (5 mL) were collected from triplicate containers on days 0, 7, 14, 21, 28, 56, 91, and 193. Color/clarity and pH changes were also monitored at each time interval. During the study, all samples remained clear and there was only a slight pH change. The color of the solutions stored at 23°C intensified but did not correlate with a significant decrease in concentration, while solutions stored at 5°C remained unchanged. Solutions repackaged in glass vials were stable for 193 days when stored at 23ºC and ETL or 5ºC and PFL. When further diluted to 3 mg/mL with normal saline and packaged in PVC bags, procainamide was also stable for 193 days at either 23ºC and ETL or 5°C and PFL. The stability of procainamide, 100 mg/mL, repackaged in clear glass vials was 193 days when stored at either 23ºC and ETL or 5ºC or PFL. If diluted further to 3 mg/mL with normal saline and packaged in PVC bags, the drug was also stable for 193 days at either 23ºC and ETL or 5°C and PFL.

  14. Componentes descriptivos y explicativos de la accidentalidad vial en Colombia: Incidencia del factor humano

    OpenAIRE

    Ervyn H. Norza Céspedes; Elba Lucía Granados León; Sergio Alejandro Useche Hernández; Mauricio Romero Hernández; Jesica Moreno Rodríguez

    2016-01-01

    Problema: Se analizó la incidencia del factor humano en la accidentalidad vial en el territorio colombiano, y se identificó evidencia empírica para la formulación de política pública del tránsito. Metodología: El diseño es descriptivo-correlacional. Instrumentos: cuestionario de comportamiento para conductores y motociclistas (D.B.Q.) y encuesta tipo Likert. Muestra no probabilística intencional: 16.322 personas (8.631 conductores de automotores, 5.133 motociclistas y 2.558 peatones, pasajero...

  15. Stability of Pantoprazole Sodium in Glass Vials, Polyvinyl Chloride Minibags, and Polypropylene Syringes

    Science.gov (United States)

    Donnelly, Ronald F

    2011-01-01

    Background: Pantoprazole sodium, a proton-pump inhibitor, is approved for the short-term treatment of several types of ulcer, Zollinger–Ellison syndrome, and gastroesophageal reflux disease. Objective: To determine the physical compatibility and chemical stability of ethylenediaminetetra-acetic acid (EDTA)–free pantoprazole in glass vials, polypropylene syringes, and polyvinylchloride (PVC) minibags, after storage at 2°C to 8°C with protection from light or at 20°C to 25°C with exposure to light. Methods: Solutions of pantoprazole 4 mg/mL reconstituted in 0.9% sodium chloride (normal saline [NS]) were stored in glass vials at 20°C to 25°C. Similar solutions were transferred to polypropylene syringes and stored at 2°C to 8°C. Stock solution was further diluted, in 5% dextrose in water (D5W) or NS, to 0.4 or 0.8 mg/mL, and samples were then packaged in PVC minibags for storage at 2°C to 8°C or at 20°C to 25°C. Samples collected on days 0, 2, 3, 7, 14, 21, and 28 were analyzed in duplicate with a stability-indicating high-performance liquid chromatography assay. Results: Pantoprazole 4 mg/mL was stable (i.e., retained at least 90% of initial concentration) for 3 days when stored in glass vials at 20°C to 25°C or for 28 days when stored in polypropylene syringes at 2°C to 8°C. Pantoprazole 0.4 mg/mL diluted in D5W and stored in PVC minibags was stable for 2 days at 20°C to 25°C or for 14 days at 2°C to 8°C. At 0.8 mg/mL, pantoprazole in D5W was stable for 3 days at 20°C to 25°C or 28 days at 2°C to 8°C. Pantoprazole diluted to either 0.4 or 0.8 mg/mL in NS and stored in PVC minibags was stable for 3 days at 20°C to 25°C or 28 days at 2°C to 8°C. Conclusions: The present study confirmed or extended previously reported expiry dates for pantoprazole sodium packaged in glass vials, polypropylene syringes, and PVC minibags. PMID:22479054

  16. Un experimento de física útil para la educación vial

    Directory of Open Access Journals (Sweden)

    Jesús Vila

    2009-01-01

    Full Text Available El índice de fallecidos y de minusvalías debido a los accidentes de coches en las vías se relaciona (1 muy directamente con el exceso de velocidad de los automóviles. En la educación vial internacional se establecen variadas estrategias para concienciar a los conductores de modo que respeten los límites de velocidades establecidos e incrementen las precauciones cuando las condiciones climatológicas así lo aconsejen.

  17. Un experimento de física útil para la educación vial

    OpenAIRE

    Jesús Vila; Carlos J. Sierra

    2009-01-01

    El índice de fallecidos y de minusvalías debido a los accidentes de coches en las vías se relaciona (1) muy directamente con el exceso de velocidad de los automóviles. En la educación vial internacional se establecen variadas estrategias para concienciar a los conductores de modo que respeten los límites de velocidades establecidos e incrementen las precauciones cuando las condiciones climatológicas así lo aconsejen.

  18. Effect of simulated microgravity and centrifugation on nitric oxide synthase activity of osteocyte-like cell line MLO-Y4

    Science.gov (United States)

    Sun, Lian-Wen; Yang, Xiao; Fan, Yu-Bo

    Bone is a highly mechanosensitive tissue, which can adapt functionally to varying levels of mechanical loads throughout a lifetime. Osteocytes are thought to be the most mechanically sensitive bone cell population. In order to understand the mechanism of microgravity-induced bone loss, it's very important to research the behavior of osteocytes under microgravity. In this study, rotary cell culture system was used to simulate microgravity. Nitric oxide synthase (NOS) activity in osteocyte-like cell MLO-Y4 was investigated under simulated microgravity. And the effect of centrifugation on NOS activity in sedentary and rotary culture cell was also investi-gated. The cultured cells were divided into four groups, including sedentary control (CON), sedentary control and centrifugation (CONC), rotary culture (RT), rotary and centrifugation (RTC). In CONC and RTC, NOS activity was determined after centrifugation (1100g 5min). The results showed NOS activity decreased significantly in RT compared with CON. However, this difference disappeared after centrifugation. On the other hand, NOS activity increased significant in RTC compared with RT while there was no difference between CON and CONC. These results indicate the normal centrifugation could counter the effect of simulated micro-gravity on NOS activity. However, it has no effect on the cells cultured under 1G. In general, osteocytes under simulated microgravity are more sensitive to centrifugation than that under 1G.

  19. Centrifugal acceleration in the magnetotail lobes

    Directory of Open Access Journals (Sweden)

    H. Nilsson

    2010-02-01

    Full Text Available Combined Cluster EFW and EDI measurements have shown that cold ion outflow in the magnetospheric lobes dominates the hydrogen ion outflow from the Earth's atmosphere. The ions have too low kinetic energy to be measurable with particle instruments, at least for the typical spacecraft potential of a sunlit spacecraft in the tenuous lobe plasmas outside a few RE. The measurement technique yields both density and bulk velocity, which can be combined with magnetic field measurements to estimate the centrifugal acceleration experienced by these particles. We present a quantitative estimate of the centrifugal acceleration, and the velocity change with distance which we would expect due to centrifugal acceleration. It is found that the centrifugal acceleration is on average outward with an average value of about of 5 m s−2. This is small, but acting during long transport times and over long distances the cumulative effect is significant, while still consistent with the relatively low velocities estimated using the combination of EFW and EDI data. The centrifugal acceleration should accelerate any oxygen ions in the lobes to energies observable by particle spectrometers. The data set also put constraints on the effectiveness of any other acceleration mechanisms acting in the lobes, where the total velocity increase between 5 and 19 RE geocentric distance is less than 5 km s−1.

  20. Centrifugal acceleration in the magnetotail lobes

    Directory of Open Access Journals (Sweden)

    H. Nilsson

    2010-02-01

    Full Text Available Combined Cluster EFW and EDI measurements have shown that cold ion outflow in the magnetospheric lobes dominates the hydrogen ion outflow from the Earth's atmosphere. The ions have too low kinetic energy to be measurable with particle instruments, at least for the typical spacecraft potential of a sunlit spacecraft in the tenuous lobe plasmas outside a few RE. The measurement technique yields both density and bulk velocity, which can be combined with magnetic field measurements to estimate the centrifugal acceleration experienced by these particles. We present a quantitative estimate of the centrifugal acceleration, and the velocity change with distance which we would expect due to centrifugal acceleration. It is found that the centrifugal acceleration is on average outward with an average value of about of 5 m s−2. This is small, but acting during long transport times and over long distances the cumulative effect is significant, while still consistent with the relatively low velocities estimated using the combination of EFW and EDI data. The centrifugal acceleration should accelerate any oxygen ions in the lobes to energies observable by particle spectrometers. The data set also put constraints on the effectiveness of any other acceleration mechanisms acting in the lobes, where the total velocity increase between 5 and 19 RE geocentric distance is less than 5 km s−1.

  1. Elementos del impacto ambiental producido por los deslizamientos de taludes viales colombianos

    Directory of Open Access Journals (Sweden)

    Lisandro Beltrán Moreno

    2011-01-01

    Full Text Available Las características orográficas; climáticas y geotécnices, junto con las condiciones impuestas por el tipo y el nivel de desarrollo en el territorio colombiano favorecen la ocurrencia de los deslizamientos. Durante las épocas de invierno se producen numerosos y a veces grandes movimiento en masa en los taludes viales causando notables pérdidas físicas y económicas. Para reducirlas se pueden mejorar los procedimientos seguidos durante el diseño, la interventorie, y la construcción. En este artículo se describen aquellos factores y condiciones que favorecen la ocurrencia de los movimientos en masa, se mencionan las características de estos últimos determinadas mediante un inventario reciente, se indican las deficiencias actuales más notorias qce se encuentran en el diseño y en la construcción de carreteras, y se incluyen informaciones sobre costos parciales de los daños ocasionados por  los derrumbes de los taludes viales. Este trabajo fue publicado en las memorias del lV Congreso Colombiano de Geotecnia, que se realizó en Bogotá, entre el 20 y 23 de agosto de 1991.

  2. CONTROL SYSTEM SURGE OF CENTRIFUGAL COMPRESSORS

    Directory of Open Access Journals (Sweden)

    M. V. Tsabenko

    2016-07-01

    Full Text Available The article investigates the anti-surge protection systems and mathematical modeling of systems of gas compressor units on the basis of centrifugal compressors with anti-surge valve or baypass, and a mixed protection system. The review of existing systems, surge protection of gas compressor units, which revealed a number of shortcomings when using antisurge valve or baypass system. The proposed mixed system of surge protection with simultaneous use of surge valve and baypass system. The proposed sequence of the mixed system of surge protection. The above block diagram of an electromechanical system centrifugal compressor – anti-surge valve - direct current motor with an automatic control system. Obtained by use of transient surge valve baypass and mixed anti-surge system. These conclusions underline the relevance of the research and energy efficiency centrifugal compressor anti-surge protection system.

  3. Centrifugal compressor design for electrically assisted boost

    Science.gov (United States)

    Y Yang, M.; Martinez-Botas, R. F.; Zhuge, W. L.; Qureshi, U.; Richards, B.

    2013-12-01

    Electrically assisted boost is a prominent method to solve the issues of transient lag in turbocharger and remains an optimized operation condition for a compressor due to decoupling from turbine. Usually a centrifugal compressor for gasoline engine boosting is operated at high rotational speed which is beyond the ability of an electric motor in market. In this paper a centrifugal compressor with rotational speed as 120k RPM and pressure ratio as 2.0 is specially developed for electrically assisted boost. A centrifugal compressor including the impeller, vaneless diffuser and the volute is designed by meanline method followed by 3D detailed design. Then CFD method is employed to predict as well as analyse the performance of the design compressor. The results show that the pressure ratio and efficiency at design point is 2.07 and 78% specifically.

  4. Centrifugal Trends in Collective Bargaining

    OpenAIRE

    Raluca DIMITRIU

    2013-01-01

    Labour Law is dealing with a period of tremendous changes, which may even jeopardise its legitimacy. Solidarity between employees has lost its vigour since the organisational culture of the company shows a trend towards internal competition. Indeed, decreased union membership and increased number of collective labour agreements seems to definitely mark a new era of labour relations. Today, solidarity, a basic principle of the collective labour law, seems to have diminished; employees perceive...

  5. Safety Factor Analysis for Centrifuge Systems.

    Science.gov (United States)

    1991-07-24

    implementation 27 3.3 Project QA files 28 3.4 Document control 28 3.5 Calculations 29 3.6 Reports 29 3.7 Audits and nonconformances 29 3.8 Documentation...stop it should be possible to rotate the centrifuge manually when the motor is at a stop. 2.2.18 Behaviour of the centrifuge during power cuts or surges...periodic review and audit of QA files, records and WES input; 4. Evaluation of nonconformance reports; 5. Definition of remedial measures and follow-um

  6. Evaluación técnica de los puentes en la infraestructura vial del departamento de Antioquia

    OpenAIRE

    Garcia, John Mario; Ospina Giraldo, Jaime; Graciano, Edir Amparo

    2014-01-01

    El desarrollo económico y social de una región está directamente relacionado con el estado de su infraestructura vial. La falla de un puente genera la interrupción total del tráfico de bienes en su superficie, generando incalculables pérdidas materiales y sociales mientras se restituye el flujo vehicular. El departamento de Antioquia cuenta en su patrimonio vial con una de las redes más extensas del territorio colombiano. La gobernación departamental es la encargada del adecuado funcionamient...

  7. Educación vial en la Escuela Primaria para Prevención de Accidentes de Peatones

    OpenAIRE

    Alvarado, Danilo Eliseo

    2015-01-01

    179 p. Este estudio presenta un análisis profundo en el marco de la educación vial en la escuela primaria, enfocado en los docentes del establecimiento educativo 23 de Agosto Nº 85, sobre que concepciones de educación vial para la prevención de accidentes de peatones poseen estos y, cuales son los fundamentos legales y teóricos que usan para la implementación dentro del marco regulatorio que lo establece la ley nacional 24.449.

  8. Componentes descriptivos y explicativos de la accidentalidad vial en Colombia: Incidencia del factor humano

    Directory of Open Access Journals (Sweden)

    Ervyn H. Norza Céspedes

    2016-03-01

    Full Text Available Problema: Se analizó la incidencia del factor humano en la accidentalidad vial en el territorio colombiano, y se identificó evidencia empírica para la formulación de política pública del tránsito. Metodología: El diseño es descriptivo-correlacional. Instrumentos: cuestionario de comportamiento para conductores y motociclistas (D.B.Q. y encuesta tipo Likert. Muestra no probabilística intencional: 16.322 personas (8.631 conductores de automotores, 5.133 motociclistas y 2.558 peatones, pasajeros y acompañantes. Resultados: a conductores con nivel educativo superior inciden en menos accidentes; b peatones con menor nivel educativo inciden en mayores conductas riesgosas; c las mujeres tienen actitud positiva y perciben eficacia de campañas en prevencion; d estilos de conducción iracundo, ansioso, riesgoso y de alta velocidad cometen más infracciones y accidentes; e desobedecer señales de tránsito, la principal causa de accidentalidad; f agresividad, hostilidad y estrés en el tránsito son factores que aumentan la probabilidad de accidente; g campañas de prevención no están siendo captadas por la población más afectada. Conclusiones y recomendaciones: Los factores de accidentalidad vial guardan correspondencia con el Triángulo de Seguridad Vial establecido por la Organización de las Naciones Unidas -factor humano preponderante en la accidentalidad-. Lineamientos de política pública fundamentados en procesos educativos y corporativos tendientes a disminuir la accidentalidad por lo general no se concibe aplicada a la seguridad pública. Por ello, se presenta la inteligencia criminal como una disciplina que se ocupa de anticipar los riesgos criminales contra la seguridad pública. Esto permitiría disminuir la incertidumbre durante la toma de decisiones y calcular los daños contra la seguridad pública, que se pretende prevenir.

  9. Design of Structural Parameters for Centrifugal Elevator Overspeed Governors

    Directory of Open Access Journals (Sweden)

    Song Yunpu

    2014-01-01

    Full Text Available As an important part of overspeed and fail-safe protection for elevators, the centrifugal elevator overspeed governor is a device for limiting overspeed of elevator cars. This paper researches on the vibration of the centrifugal block, which plays a key role in the performance of this overspeed governor. By performing dynamics analysis on the centrifugal block, the differential equation on the vibration of the centrifugal block is established. Based on this, the paper performs simulation analysis on the influence of systematic parameters such as the speed of the overspeed governor sheave, the mass of centrifugal block, the turning radius of the centrifugal block, the position where the spring acts, and the stiffness of the centrifugal block spring, on the vibration of the centrifugal block, and finds out their specific influence relationship.

  10. Centrifugal Sieve for Size-Segregation/ Beneficiation of Regolith Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Utilizing centrifugal force as the primary body-force, combined with both shearing flow and vibratory motion the proposed centrifugal-sieve separators can provide...

  11. Purification of Encephalitozoon Cultures Contaminated by Mycoplasmas by Murine Intraperitoneal Inoculation

    Science.gov (United States)

    Ridoux, Olivier; Foucault, Cédric; Drancourt, Michel

    1998-01-01

    Encephalitozoon species are strict intracellular microsporidia. Cocultures with eukaryotic cell lines can become accidently contaminated by mycoplasmas. We propose a decontamination protocol based on differential cell targeting after intraperitoneal inoculation in mice. Mycoplasma-free microsporidia were isolated from the brains and spleens of inoculated mice 24 h postinoculation by using the centrifugation shell vial system. Identification was confirmed by direct sequencing of PCR-amplified 16S rRNA. PMID:9666031

  12. Differential white cell count by centrifugal microfluidics.

    Energy Technology Data Exchange (ETDEWEB)

    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.

  13. Separation mechanisms in a plasma centrifuge

    Energy Technology Data Exchange (ETDEWEB)

    Timchenko, N.N.; Khripunov, B.I.

    1979-01-01

    The separation of elements and isotopes is studied in a fully ionized plasma with crossed E and H fields. Two separation mechanisms, the centrifuge mechanism and polarization, are discussed. The parameter ranges in which each of these mechanisms is important are found. The mechanisms are compared in terms of relative efficiency.

  14. Mass Transfer in 12-CM Centrifugal Contactors

    Energy Technology Data Exchange (ETDEWEB)

    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.

  15. Positive feedback stabilization of centrifugal compressor surge

    NARCIS (Netherlands)

    Willems, Frank; Heemels, W.P.M.H.; de Jager, Bram; Stoorvogel, Antonie Arij

    Stable operation of axial and centrifugal compressors is limited towards low mass flows due to the occurrence of surge. The stable operating region can be enlarged by active control. In this study, we use a control valve which is fully closed in the desired operating point and only opens to

  16. Centrifugal acceleration of plasma in pulsar magnetosphere

    Indian Academy of Sciences (India)

    We present a relativistic model for the centrifugal acceleration of plasma bunches and the coherent radio emission in pulsar magnetosphere. We find that rotation broadens the width of leading component compared to the width of trailing component. We explain this difference in the component widths using the nested cone ...

  17. Centrifugal Pump Experiment for Chemical Engineering Undergraduates

    Science.gov (United States)

    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…

  18. Structural Optimization Including Centrifugal and Coriolis Effects

    Science.gov (United States)

    1988-01-01

    the problem with Galerkin’s method. Tomar and Dhole (1976) expanded the solution to encompass pretwisted beams, solving the equations by a conventional...Tomar, J.S. and Dhole , A. (1976) "Coupled Vibrations of a Pretwisted Slender Beam in a Centrifugal Force Field", Journal of the Aeronautical Society of

  19. Engineering design of centrifugal casting machine

    Science.gov (United States)

    Kusnowo, Roni; Gunara, Sophiadi

    2017-06-01

    Centrifugal casting is a metal casting process in which metal liquid is poured into a rotating mold at a specific temperature. Given round will generate a centrifugal force that will affect the outcome of the casting. Casting method is suitable in the manufacture of the casting cylinder to obtain better results. This research was performed to design a prototype machine by using the concept of centrifugal casting. The design method was a step-by-step systematic approach in the process of thinking to achieve the desired goal of realizing the idea and build bridges between idea and the product. Design process was commenced by the conceptual design phase and followed by the embodiment design stage and detailed design stage. With an engineering design process based on the method developed by G. E. Dieter, draft prototype of centrifugal casting machine with dimension of 550×450×400 mm, ¼ HP motor power, pulley and belt mechanism, diameter of 120-150mm, simultaneously with the characteristics of simple casting product, easy manufacture and maintenance, and relatively inexpensive, was generated.

  20. Design Optimization of Centrifugal Pump Using Radial Basis Function Metamodels

    OpenAIRE

    Yu Zhang; Jinglai Wu; Yunqing Zhang; Liping Chen

    2014-01-01

    Optimization design of centrifugal pump is a typical multiobjective optimization (MOO) problem. This paper presents an MOO design of centrifugal pump with five decision variables and three objective functions, and a set of centrifugal pumps with various impeller shroud shapes are studied by CFD numerical simulations. The important performance indexes for centrifugal pump such as head, efficiency, and required net positive suction head (NPSHr) are investigated, and the results indicate that th...

  1. Hacia un análisis sociológico de la siniestrabilidad vial

    Directory of Open Access Journals (Sweden)

    Emilio Sánchez Ferreira

    2012-01-01

    Full Text Available Este artículo reivindica la importancia de una sociología de los transportes, un área esencial para nuestras sociedades que tradicionalmente las ciencias sociales no han atendido. Este vacío científico se ha trasladado a las investigaciones sobre la siniestrabilidad vial. En su lugar han imperado estudios sin verdadera base científica que, divulgados por los medios de comunicación, no permiten a la opinión pública visualizar la realidad del problema. Las instituciones de tráfico se limitan a establecer medidas recaudatorias y a responsabilizar a los conductores. Sin embargo, un análisis detallado de los datos y un cuestionamiento razonado de los planteamientos oficiales pueden desvelarnos las auténticas causas de los accidentes.

  2. Effect of centrifugation and microagglutination techniques on Brucella agglutinin titers.

    OpenAIRE

    Klein, G C; Behan, K A; Brown, S L; Couch, E E

    1982-01-01

    The microagglutination technique without centrifugation was more effective than centrifugation of the standard tube test for increasing Brucella agglutinin titers of specimens with a titer greater than or equal to 160 but was less effective than centrifugation of the standard tube test for specimens with a titer less than 160.

  3. Safety and efficacy of multiuse botulinum toxin vials for intralaryngeal injection.

    Science.gov (United States)

    Barrow, Emily M; Rosen, Clark A; Hapner, Edie R; Smith, Sarah; Hatcher, Jeanne L; Simpson, Blake; Johns, Michael M

    2015-05-01

    Centers for Disease Control and Prevention guidelines maintain that single-use vials cannot be used for multiple patients. Botox product labeling states that the reconstituted toxin should be used within 4 hours on a single patient based on concerns of reduced potency, contamination, and consequent infections. The purpose of this study was to determine the safety and efficacy of using single-use vials in a multidose fashion. Prospective study and cohort chart review. A multi-institutional three-part study was performed between May 2013 and October 2013: 1) a summation of subjects' recall of their past experiences (symptoms/response) with previous multidose Botox injections, 2) a prospective study of intralaryngeal injections, and 3) a chart review of injection responses in a subset of the cohort. Seven hundred forty-three subjects receiving 6,216 injections demonstrated zero infection-related complications on retrospective chart review. One hundred seventy-nine subjects recalled 24.0% overall adverse events, 10.6% redness, 7.3% pain and swelling at the injection site, and 0% fever. One hundred seventy-four subjects prospectively reported 12.6% overall adverse events. The self-reported efficacy rate of Botox injection was 96.6%. The low rates of adverse events following the use of Botox in a multipatient fashion are consistent with other percutaneous injections. No evidence of infection was found with multidose Botox use. Given the low incidence of side effects and high success rate, Botox can be used both safely and effectively in a multipatient fashion. 4 © 2014 The American Laryngological, Rhinological and Otological Society, Inc.

  4. Culture

    OpenAIRE

    Smith, Timothy B.; Melanie M. Domenech Rodríguez; Bernal, Guillermo

    2011-01-01

    This article summarizes the definitions, means, and research of adapting psychotherapy to clients' cultural backgrounds. We begin by reviewing the prevailing definitions of cultural adaptation and providing a clinical example. We present an original meta-analysis of 65 experimental and quasi-experimental studies involving 8,620 participants. The omnibus effect size of d = .46 indicates that treatments specifically adapted for clients of color were moderately more effective with that clientele...

  5. Seguridad Vial y Procesos Psicológicos: Acciones Preventivas. [ Road Safety and Psychological Processes: Preventive Actions

    Directory of Open Access Journals (Sweden)

    Manuel Ernesto Riaño Garzón

    2017-01-01

    Full Text Available El artículo revisa la relación entre los procesos psicológicos y la seguridad vial desde una postura preventiva con el fin de proporcionar evidencias sobre alternativas utilizadas en terapia que puedan ser de utilidad para el adecuado funcionamiento psico-fisiológico y que determinen una mayor Seguridad Vial. Dicha revisión resulta pertinente en el marco de la Policía Nacional y de la Seguridad Vial en tanto ilustra metodologías empíricamente validadas que pueden ser utilizadas por las personas que desarrollen labores de alto esfuerzo cognitivo como la conducción. Con el fin de desarrollar la temática propuesta, se revisarán las nociones iniciales de la accidentalidad en tránsito dando paso a la revisión de los procesos cognoscitivos implicados en la seguridad vial citando algunos estudios empíricos que dan cuenta de métodos de utilidad en el incremento de las capacidades del conductor. Se concluye la efectividad de métodos basados en estimulación cognoscitiva y bioretroalimentación para el fortalecimiento de procesos cognoscitivos especialmente atencionales, advirtiendo la relación directamente proporcional entre la capacidad atencional y la seguridad al conducir.

  6. Culture

    OpenAIRE

    Coulangeon, Philippe

    2013-01-01

    Il n’est sans doute pas de notion aussi vaste et aussi polysémique en sciences sociales que la notion de culture, qui renvoie alternativement à l’ensemble des symboles, des significations, des valeurs et des manières de faire propres à un groupe et au domaine spécialisé des activités expressives, savantes et populaires. La notion de culture est ainsi tout autant mobilisée dans l’exploration des grandes thématiques de la sociologie (stratification, inégalités, institutions, mouvements sociaux)...

  7. Container/Closure Integrity Testing and the Identification of a Suitable Vial/Stopper Combination for Low-Temperature Storage at -80 {degrees}C.

    Science.gov (United States)

    Zuleger, Brigitte; Werner, Uwe; Kort, Alexander; Glowienka, Rene; Wehnes, Engelbert; Duncan, Derek

    2012-01-01

    It was recently found that after storage of a live viral vaccine at -80 °C in glass vials closed with rubber stoppers, a phenomenon was revealed which had not been observed before with other viral products stored at -20 °C: overpressure in the vials. As this phenomenon poses a serious safety problem for medical personnel as well as for the product itself, an investigation was initiated to identify the root cause of the overpressure. After exclusion of possible root causes (differences in air temperature or atmospheric air pressure during filling and quality control testing, outgassing from the formulation buffer) the remaining hypothesis involved a possible container closure integrity issue at low temperature. The glass transition temperatures (T(g)) of many rubber stopper formulations are in the range -55 to -70 °C. At storage temperatures below T(g), the rubber stopper loses its elastic properties and there is a risk that the seal integrity of the vial could be compromised. Loss of seal integrity of the vials near storage temperatures of -80 °C would result in an ingress of cold dense gas into the vial headspace. After removal of the vials from storage at -80 °C, the rubber stoppers could regain their elastic properties and the vials would quickly reseal, thereby trapping the ingressed gas, which leads to overpressure in the vial headspace. Nondestructive laser-based headspace analysis was used to investigate the maintenance of container closure integrity as a function of the filling and capping/crimping process, storage and transport conditions, and vial/stopper designs. This analytical method is based on frequency modulation spectroscopy (FMS) and can be used for noninvasive headspace measurements of headspace pressure and headspace gas composition. Changes in the vial headspace composition and/or pressure are a clear marker for vials that have lost container closure integrity. After storage of a live viral vaccine at -80 °C in glass vials closed with

  8. Cavitation pulse extraction and centrifugal pump analysis

    Energy Technology Data Exchange (ETDEWEB)

    Luo, Hong Lind Shaoran [University of Electronic Science and Technology of China, Chengdu (China); Yu, Bo; Qing, Biao [Xihua University, Chengdu (China)

    2017-03-15

    This study extracted cavitation pulses from hydrophone signals sampled in a centrifugal pump and analyzed their characteristics. The modified and simplified Empirical mode decomposition (EMD) algorithm was proposed for extracting cavitation pulses from strong background noise. Experimental results showed that EMD can effectively suppress noise and obtain clear cavitation pulses, facilitating the identification of the number of pulses associated with the degree of cavitation. The cavitation characteristics were modeled to predict the value of incipient cavitation. Then, we proposed a method for detecting the wear of the impeller surface. That is, the information on the impeller surface of the centrifugal pump, including the roughness of the impeller surface and its wear trends, were quantified based on the net positive suction head available of incipient cavitation. The findings indicate that the proposed technique is suitable for condition monitoring of the pump.

  9. A vibration model for centrifugal contactors

    Energy Technology Data Exchange (ETDEWEB)

    Leonard, R.A.; Wasserman, M.O.; Wygmans, D.G.

    1992-11-01

    Using the transfer matrix method, we created the Excel worksheet ``Beam`` for analyzing vibrations in centrifugal contactors. With this worksheet, a user can calculate the first natural frequency of the motor/rotor system for a centrifugal contactor. We determined a typical value for the bearing stiffness (k{sub B}) of a motor after measuring the k{sub B} value for three different motors. The k{sub B} value is an important parameter in this model, but it is not normally available for motors. The assumptions that we made in creating the Beam worksheet were verified by comparing the calculated results with those from a VAX computer program, BEAM IV. The Beam worksheet was applied to several contactor designs for which we have experimental data and found to work well.

  10. Continuous centrifuge decelerator for polar molecules.

    Science.gov (United States)

    Chervenkov, S; Wu, X; Bayerl, J; Rohlfes, A; Gantner, T; Zeppenfeld, M; Rempe, G

    2014-01-10

    Producing large samples of slow molecules from thermal-velocity ensembles is a formidable challenge. Here we employ a centrifugal force to produce a continuous molecular beam with a high flux at near-zero velocities. We demonstrate deceleration of three electrically guided molecular species, CH3F, CF3H, and CF3CCH, with input velocities of up to 200  m s(-1) to obtain beams with velocities below 15  m s(-1) and intensities of several 10(9)  mm(-2) s(-1). The centrifuge decelerator is easy to operate and can, in principle, slow down any guidable particle. It has the potential to become a standard technique for continuous deceleration of molecules.

  11. Continuous Centrifuge Decelerator for Polar Molecules

    CERN Document Server

    Chervenkov, S; Bayerl, J; Rohlfes, A; Gantner, T; Zeppenfeld, M; Rempe, G

    2013-01-01

    Producing large samples of slow molecules from thermal-velocity ensembles is a formidable challenge. Here we employ a centrifugal force to produce a continuous molecular beam with a high flux at near-zero velocities. We demonstrate deceleration of three electrically guided molecular species, CH$_3$F, CF$_3$H, and CF$_3$CCH, with input velocities of up to $200\\,\\rm{m\\,s^{-1}}$ to obtain beams with velocities below $15\\,\\rm{m\\,s^{-1}}$ and intensities of several $10^9\\,\\rm{mm^{-2}\\,s^{-1}}$. The centrifuge decelerator is easy to operate and can, in principle, slow down any guidable particle. It has the potential to become a standard technique for continuous deceleration of molecules.

  12. Fractal structures in centrifugal flywheel governor system

    Science.gov (United States)

    Rao, Xiao-Bo; Chu, Yan-Dong; Lu-Xu; Chang, Ying-Xiang; Zhang, Jian-Gang

    2017-09-01

    The global structure of nonlinear response of mechanical centrifugal governor, forming in two-dimensional parameter space, is studied in this paper. By using three kinds of phases, we describe how responses of periodicity, quasi-periodicity and chaos organize some self-similarity structures with parameters varying. For several parameter combinations, the regular vibration shows fractal characteristic, that is, the comb-shaped self-similarity structure is generated by alternating periodic response with intermittent chaos, and Arnold's tongues embedded in quasi-periodic response are organized according to Stern-Brocot tree. In particular, a new type of mixed-mode oscillations (MMOs) is found in the periodic response. These unique structures reveal the natural connection of various responses between part and part, part and the whole in parameter space based on self-similarity of fractal. Meanwhile, the remarkable and unexpected results are to contribute a valid dynamic reference for practical applications with respect to mechanical centrifugal governor.

  13. Windmilling characteristics of centrifugal-flow turbojets

    Energy Technology Data Exchange (ETDEWEB)

    Su, Yoo Il [Korea Advanced Institute of Science and Technology, Daejeon (Korea, Republic of); Jin, Song Seung [Seoul Natioal Univ., Seoul (Korea, Republic of); Shik, Lim Jin [Agency for Defense Development, Daejeon (Korea, Republic of)

    2004-11-01

    A new nondimensional method for predicting the windmilling performance of centrifugal-flow turbojet engines in flight has been developed. The method incorporates loss correlations to estimate the performance of major engine components. Given basic engine geometry, flight Mach number, and ambient conditions, this method predicts transient and steady-state windmilling performance. Thus, this method can be used during the preliminary design stage when detailed hardware geometry and component performance data are not yet available. A nondimensional time parameter is newly defined, and using this parameter, the transient performance of different types of turbojets (e.g. centrifugal vs. axial) is compared. In addition, the predictions' sensitivity to loss correlations, slip factors, and inlet ambient temperatures are analyzed.

  14. Meridional Considerations of the Centrifugal Compressor Development

    Directory of Open Access Journals (Sweden)

    C. Xu

    2012-01-01

    Full Text Available Centrifugal compressor developments are interested in using optimization procedures that enable compressor high efficiency and wide operating ranges. Recently, high pressure ratio and efficiency of the centrifugal compressors require impeller design to pay attention to both the blade angle distribution and the meridional profile. The geometry of the blades and the meridional profile are very important contributions of compressor performance and structure reliability. This paper presents some recent studies of meridional impacts of the compressor. Studies indicated that the meridional profiles of the impeller impact the overall compressor efficiency and pressure ratio at the same rotational speed. Proper meridional profiles can improve the compressor efficiency and increase the overall pressure ratio at the same blade back curvature.

  15. Cultural

    Science.gov (United States)

    Wilbur F. LaPage

    1971-01-01

    A critical look at outdoor recreation research and some underlying premises. The author focuses on the concept of culture as communication and how it influences our perception of problems and our search for solutions. Both outdoor recreation and science are viewed as subcultures that have their own bodies of mythology, making recreation problems more difficult to...

  16. Wave-driven Countercurrent Plasma Centrifuge

    Energy Technology Data Exchange (ETDEWEB)

    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. Centrifugal shot blasting. Innovative technology summary report

    Energy Technology Data Exchange (ETDEWEB)

    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.

  18. Leaching of plastic polymers by plastic vials used for storing homoeopathic medicines: A preliminary study

    Directory of Open Access Journals (Sweden)

    Neeraj Gupta

    2014-01-01

    Full Text Available Background: In Homoeopathy, plastic containers/vials are used for the storing/dispensing of ethanol-based medicines instead of glass. Various studies have suggested that plastic components that leach out in stored substances tend to cause contamination and may produce adverse effects in living systems. The present study was aimed to find out chemical composition and leaching behaviour of commonly used plastic vials (PVs if any during the storage of ethanol-based homoeopathic medicines in optimal environment. Material and Methods: The experiments were conducted on two sample sets of PVs. Chemical properties of PV were assessed by Fourier Transform Infrared Attenuated Total Reflectance (FTIR-ATR spectroscopy. PV were cut separately [sample-1 (S-1 and sample-2 (S-2] and immersed in Homoeopathic Grade Ethanol (HGE in conical flask and stored for 7 days at ambient temperature (25° ± 5C with constant rotary shaking. After 7 days, S-1 and S-2 of PV in Homoeopathic Grade Ethanol (HGE were decanted and filtered. Aliquots (A1 and A2 were analysed by proton nuclear magnetic resonance spectroscopy (H 1 NMR. The spectral graph obtained by FTIR-ATR spectroscopy for PV compositions and spectral graph obtained by H 1 NMR spectroscopy for PV ethanol aliquots were examined for PVs material and PV leaching effect in HGE. Results: FTIR-ATR spectra showed that PV are made up of two types of polyolefin′s compounds i.e. Low Density Polyethylene (LDPE and Linear Low Density Polyethylene (LLDPE. Aliquots of PV in HGE showed the presence benzophenone and its methyl derivative, heat and light stabiliser (2, 2, 6, 6-tetramethylpiperidine and amino derivative, antioxidant (4, 4′- thiobis and 2-tertbutyl-5-methylphenol and plasticizer bis 2-Diethylhexyl phthalate (DEHP or Dioctyl phthalate (DOP. Results of study suggest that PVs leach out plastic polymers in HGE. Conclusion: This preliminary experiment suggests that it is not safe to use LDPE/LLDPE plastic for storing

  19. cultural

    Directory of Open Access Journals (Sweden)

    Irene Kreutz

    2006-01-01

    Full Text Available Es un estudio cualitativo que adoptó como referencial teorico-motodológico la antropología y la etnografía. Presenta las experiencias vivenciadas por mujeres de una comunidad en el proceso salud-enfermedad, con el objetivo de comprender los determinantes sócio-culturales e históricos de las prácticas de prevención y tratamiento adoptados por el grupo cultural por medio de la entrevista semi-estructurada. Los temas que emergieron fueron: la relación entre la alimentación y lo proceso salud-enfermedad, las relaciones con el sistema de salud oficial y el proceso salud-enfermedad y lo sobrenatural. Los dados revelaron que los moradores de la comunidad investigada tienen un modo particular de explicar sus procedimientos terapéuticos. Consideramos que es papel de los profesionales de la salud en sus prácticas, la adopción de abordajes o enfoques que consideren al individuo en su dimensión sócio-cultural e histórica, considerando la enorme diversidad cultural en nuestro país.

  20. Vial usage, device dead space, vaccine wastage, and dose accuracy of intradermal delivery devices for inactivated poliovirus vaccine (IPV).

    Science.gov (United States)

    Jarrahian, Courtney; Rein-Weston, Annie; Saxon, Gene; Creelman, Ben; Kachmarik, Greg; Anand, Abhijeet; Zehrung, Darin

    2017-03-27

    Intradermal delivery of a fractional dose of inactivated poliovirus vaccine (IPV) offers potential benefits compared to intramuscular (IM) delivery, including possible cost reductions and easing of IPV supply shortages. Objectives of this study were to assess intradermal delivery devices for dead space, wastage generated by the filling process, dose accuracy, and total number of doses that can be delivered per vial. Devices tested included syringes with staked (fixed) needles (autodisable syringes and syringes used with intradermal adapters), a luer-slip needle and syringe, a mini-needle syringe, a hollow microneedle device, and disposable-syringe jet injectors with their associated filling adapters. Each device was used to withdraw 0.1-mL fractional doses from single-dose IM glass vials which were then ejected into a beaker. Both vial and device were weighed before and after filling and again after expulsion of liquid to record change in volume at each stage of the process. Data were used to calculate the number of doses that could potentially be obtained from multidose vials. Results show wide variability in dead space, dose accuracy, overall wastage, and total number of doses that can be obtained per vial among intradermal delivery devices. Syringes with staked needles had relatively low dead space and low overall wastage, and could achieve a greater number of doses per vial compared to syringes with a detachable luer-slip needle. Of the disposable-syringe jet injectors tested, one was comparable to syringes with staked needles. If intradermal delivery of IPV is introduced, selection of an intradermal delivery device can have a substantial impact on vaccine wasted during administration, and thus on the required quantity of vaccine that needs to be purchased. An ideal intradermal delivery device should be not only safe, reliable, accurate, and acceptable to users and vaccine recipients, but should also have low dead space, high dose accuracy, and low overall

  1. Development of Conductivity Method as an Alternative to Titration for Hydrolytic Resistance Testing Used for Evaluation of Glass Vials Used in Pharmaceutical Industry.

    Science.gov (United States)

    Fujimori, Kiyoshi; Lee, Hans; Phillips, Joseph; Nashed-Samuel, Yasser

    The European Pharmacopeia surface test to analyze the hydrolytic resistance is a common industrial method to understand and ensure the quality of produced glass vials. Hydrolytic resistance is evaluated by calculating the alkalinity of water extract from autoclaved vials by titration. As an alternative to this titration technique, a conductivity technique was assessed, which directly measures the ions in the water extract. A conductivity meter with a 12 mm diameter electrode was calibrated with a 100 μS/cm conductivity standard and carryover minimized by rinsing the probe in a water beaker per analysis. The limit of quantification at 1 μS/cm was determined as having a signal-to-noise ratio of 3 compared with the water blank. The conductivity method was selective for glass-composing elements (boron, sodium, aluminum, silicon, potassium, and calcium) within the vial extract. Accuracies of spiked conductivity standard within the range of 1 to 100 μS/cm were ±7% and had linearity with coefficient of determination (R 2 ) of ≥0.9999. Intraday precision had a relative standard deviation (RSD) (n = 5) of ≤6% for spiked conductivity standard within the range of 1 to 100 μS/cm. Interday precision had a RSD (n = 4) of ≤6% for 10 vials from three glass vial lots. Conductivity of water extracts from nine sets of seven lots of glass vials had a precise linear relationship [R 2 = 0.9876, RSD = 1% (n = 9)] with titration volumes of the same lots. Conductivity results in μS/cm could be converted to titration volumes in milliliters by a conversion factor of 0.0275. The simplicity, sample stability, and individual vial analysis of the conductivity technique were more advantageous than the current titration technique. The quality of glass vials used as primary containers in the pharmaceutical industry is of concern due to recent observations of glass flake-like delamination, or lamellae, under specific storage conditions. The current European Pharmacopoeia method to assess

  2. Predictores Psicosociales de Delitos contra la Seguridad Vial: Un Estudio con Internos de un Centro Penitenciario

    Directory of Open Access Journals (Sweden)

    Félix Herraiz Gonzalo

    2011-01-01

    Full Text Available En el Centro Penitenciario de Hombres de Barcelona ha habido un aumento creciente de ingresos por delitos contra la seguridad vial. El objetivo de esta investigación es obtener un perfil psicológico en una muestra de 115 internos, analizar cuáles son los predictores en la conducción agresiva, y finalmente contrastar la posible existencia de diferentes tipologías, en función de la ausencia o presencia de otros delitos, con o sin componentes agresivos. Los resultados muestran que las causas o estados que causan irritación, los antecedentes familiares de conducción agresiva y la presencia de trastornos psiquiátricos son predictores de la conducta agresiva en la conducción, así como la agresividad física es también un predictor de los accidentes. No hay diferencias en internos que también presentan otras tipologías delictivas.

  3. Culture

    OpenAIRE

    Dubois, Vincent

    2007-01-01

    Le découpage des spécialités sociologiques hésite habituellement entre une répartition thématique par domaines empiriquement distingués et un partage conceptuel reposant sur des orientations de recherche. La sociologie de la culture n'échappe pas à cette oscillation. De prime abord, elle couvre un secteur plus ou moins clairement délimité, qui englobe la sociologie de l'art et ce qui est socialement désigné comme relevant de la « vie culturelle ». Elle regroupe alors un ensemble de subdivisio...

  4. La Webquest como innovación educativa en el ámbito de la educación vial

    Directory of Open Access Journals (Sweden)

    Rosa María GOIG MARTÍNEZ

    2013-01-01

    Full Text Available La Educación Vial en las edades tempranas se puede implementar a través de cuentos, talleres, rincones de juego, patios de recreo, salidas extraescolares, actividades de psicomotricidad. Sin embargo, es importante destacar el papel de las Tecnologías de la Información y la Comunicación en el enriquecimiento de las propuestas de aula en relación a la Educación Vial, tomándolas como recurso complementario, en nuestro contexto, la Webquest. Sin olvidar la necesidad de seguir trabajando con los niños y las niñas situaciones reales ligadas a sus experiencias vitales en materia de Educación Vial, pues el mundo real nunca debiera ser desplazado por el mundo virtual en ningún caso, máxime si tenemos en cuenta que se trata de la etapa de Educación Infantil. El objetivo general de este artículo es corroborar que la Webquest constituye una auténtica oportunidad para innovar en el ámbito de la Educación Vial, ofreciendo al alumnado experiencias didácticas coherentes y complementarias desde la etapa de Educación Infantil. La metodología, de carácter cuantitativo y cualitativo, se desarrolló a través de la aplicación de un cuestionario, de una entrevista, del análisis documental y su triangulación, finalizando con el análisis de los datos obtenidos. Una de las conclusiones obtenidas expone que la Webquest es un recurso que nos facilita el proceso de enseñanza-aprendizaje y aumenta la motivación tanto en alumnos como en agentes educativos.

  5. Validation of a Minor Modification to the Soleris® Direct Yeast and Mold Vial and Selective Supplement.

    Science.gov (United States)

    Alles, Susan; McDougal, Susan; Caballero, Oscar; Mozola, Mark; Rice, Jennifer

    2015-01-01

    Here we describe results of a study to validate minor reagent formulation changes to the Soleris Direct Yeast and Mold (DYM) automated growth-based method for semi-quantitative detection of yeast and mold in food products. In order to reduce the maximum concentration of the selective agent chloramphenicol in the Soleris reagents, chloramphenicol was removed from the selective supplement and added to the vial growth medium itself. Therefore, both the vial medium and supplement have been reformulated in an alternative version of the method. A probability of detection (POD) statistical model was used to compare Soleris results at multiple test thresholds (dilutions) with plate counts determined using the U.S. Food and Drug Administration Bacteriological Analytical Manual dilution plating procedure. Three matrixes were tested; yogurt, tomato juice, and cocoa powder. POD analysis showed that the percentage of positive Soleris tests at various test thresholds were within the limits predicted by the reference method plate counts for all matrixes evaluated. Real-time stability data on three manufactured lots showed that the modified Soleris vial and supplement are stable for at a minimum of 10 months when stored at 2-8°C. In sum, results presented here demonstrate that the modifications to the Soleris DYM vial and supplement do not impact method performance. The modified Soleris DYM method can be used as an accurate alternative to conventional dilution plating procedures for semi-quantitative determination of yeast and mold at threshold levels, while saving as much as 3 days in analysis time.

  6. Centrifugal Compressors, Flow Phenomena and Performance.

    Science.gov (United States)

    1980-11-01

    compressors". February 1977. 39 PAPAILIOU K.D., VOUILLARMET A. & BOIS G. "Analyse monodimensionnelle d’un 6tage de compresseur centrifuge". Contrat Creusot...mouvemant at d’Anargie s𔄀crivent (2)ew + a Co travail a Mt .1 fectul scue contrat DET. 5-2 avec D. *temps, fmasse volumique du fluide, ~,vitesse relative A...12)) n’eat plus enti~irement inatationnaire, d’oi lIa d~no- mination de pseudo-instationnaire. Cette modification implique une diminution du noinbre

  7. Continuous Centrifuge Decelerator for Polar Molecules

    OpenAIRE

    Chervenkov, S.; Wu, X.; Bayerl, J.; Rohlfes, A.; Gantner, T.; Zeppenfeld, M.; Rempe, G.

    2013-01-01

    Producing large samples of slow molecules from thermal-velocity ensembles is a formidable challenge. Here we employ a centrifugal force to produce a continuous molecular beam with a high flux at near-zero velocities. We demonstrate deceleration of three electrically guided molecular species, CH$_3$F, CF$_3$H, and CF$_3$CCH, with input velocities of up to $200\\,\\rm{m\\,s^{-1}}$ to obtain beams with velocities below $15\\,\\rm{m\\,s^{-1}}$ and intensities of several $10^9\\,\\rm{mm^{-2}\\,s^{-1}}$. Th...

  8. Design and prototyping of micro centrifugal compressor

    Science.gov (United States)

    Mizuki, Shimpei; Minorikawa, Gaku; Hirano, Toshiyuki; Asaga, Yuichiro; Yamaguchi, Naoki; Ohta, Yutaka; Outa, Eisuke

    2003-02-01

    In order to establish the design methodology of ultra micro centrifugal compressor, which is the most important component of ultra micro gas turbine unit, a 10 times of the final target size model was designed, prototyped and tested. The problems to be solved for downsizing were examined and 2-dimensional impeller was chosen as the first model due to its productivity. The conventional 1D prediction method, CFD and the inverse design were attempted. The prototyped compressor was driven by using a turbocharger and the performance characteristics were measured.

  9. Culture

    OpenAIRE

    Boas, Franz

    2003-01-01

    L’un des objets de l’enquête anthropologique, pour laquelle des éléments peuvent être obtenus par l’étude des sociétés existantes, est l’inter-dépendance des phénomènes culturels. Alors que dans l’étude des processus de diffusion et de développement parallèle les caractères et la distribution de traits singuliers sont communément les objets de l’analyse, nous sommes conduits, ici, à considérer la culture, dans toutes ses manifestations, comme un tout. Les inventions, la vie économique, la str...

  10. EMBRYONIC DEVELOPMENTAL ANOMALY IDENTIFICATION OF GIANT MIMI-MINTUNO (Tachupleus gigas DURING ARTIFICIAL INCUBATION PERIOD IN THE VIAL BOTTLES

    Directory of Open Access Journals (Sweden)

    Ciptono Ciptono

    2016-04-01

    Full Text Available This study aims to reveal the phenomenon of presence / absence of anomalies in the early development of Mimi-giant mintuno (Tachypleus gigas during artificial incubation in the vial bottles. Samples 5 eggs are fertilized incorporated into transparent 50 bottles and vials each filled with clear sea water medium. Embryonic stages (instars hatch, bottles marked, then dumped seawater medium was replaced with 4% formalin solution and glycerin amount of 5% by volume, up to ¾ of the total volume of the vial bottles. Standard stages of giant Mimi-mintuno embryonic normal development Mimi-mintuno according to Itow (1988. The description type of anomalies contained in the post-hatching embryo development. The observations are documented in the form of stereo-microphotograph. The results showed that there are forms anomalies: (a. Delayed development, the structure of the body is not perfect; (b. In observation of the embryo hatches, open shell and egg perivitelline membrane has been opened but delayed development, the structure of the body is not perfect; (c. Embryos after hatched perfectly, abnormalities of morphologic structure such as abnormal protrusion on the dorsal carapace part found.   Keywords: Tachypleus gigas, artificially, incubation

  11. A new type of seeded continuous plasma centrifuge

    Science.gov (United States)

    Simpson, S. W.; Yue, Y.

    1999-02-01

    This paper investigates the possibility of optimizing the performance of plasma centrifuges by an appropriate choice of operating gas mixture. Plasma centrifuges with partial ionization are known to be adversely affected by plasma nonuniformities. Using the concept of a fully ionized seed may overcome the ionization instability problem. Theoretical calculations show that at a temperature as low as 3800 K, with a 0.01% mole fraction of caesium seeding in a hydrogen plasma centrifuge, the figure of merit for separation A can reach about 20, which means the separative power should be improved by approximately a factor of 2500 compared with a conventional mechanical centrifuge.

  12. Separative Power of an Optimised Concurrent Gas Centrifuge

    Directory of Open Access Journals (Sweden)

    Sergey Bogovalov

    2016-06-01

    Full Text Available The problem of separation of isotopes in a concurrent gas centrifuge is solved analytically for an arbitrary binary mixture of isotopes. The separative power of the optimised concurrent gas centrifuges for the uranium isotopes equals to δU = 12.7 (V/700 m/s2(300 K/T(L/1 m kg·SWU/yr, where L and V are the length and linear velocity of the rotor of the gas centrifuge and T is the temperature. This equation agrees well with the empirically determined separative power of optimised counter-current gas centrifuges.

  13. Research on the development of the centrifugal spinning

    Directory of Open Access Journals (Sweden)

    Zhang Zhiming

    2017-01-01

    Full Text Available Centrifugal spinning is a new and efficient method to produce nanofibers quickly. It makes use of the centrifugal force instead of high voltage to produce the nanofibers. The centrifugal spinning has many advantages such as no high voltage, high yield, simple structure, no pollution and can be applied to high polymer material, ceramic and metal material. In order to have more understand about this novel nanofibers formation method, this paper introduces the method of centrifugal spinning and the effect of rotation speed, the properties of material such as viscosity and solvent evaporation, collector distance which have an impact on nanofibers morphology and diameter were also analyzed.

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

    Science.gov (United States)

    1979-03-01

    constant electric motor driving the rotating structure of the centrifuge through a water cooled)current coupling, and worm and wheel gear box. The 225 kw...the form of leachates which pollute adjacent streams and groundwater, embankment fires and slope instability (Holubec (1976)); when water is ponded

  15. 75 FR 70300 - USEC, Inc.; American Centrifuge Lead Cascade Facility; American Centrifuge Plant; Notice of...

    Science.gov (United States)

    2010-11-17

    ... to the License Applications, and Security Program documents to reflect American Centrifuge Operating... EIE, users will be required to install a Web browser plug-in from the NRC Web site. Further information on the Web- based submission form, including the installation of the Web browser plug-in, is...

  16. Centrifugally Stimulated Exospheric Ion Escape at Mercury

    Science.gov (United States)

    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.

  17. Comparison of tau-fluvalinate, acrinathrin, and amitraz effects on susceptible and resistant populations of Varroa destructor in a vial test.

    Science.gov (United States)

    Kamler, Martin; Nesvorna, Marta; Stara, Jitka; Erban, Tomas; Hubert, Jan

    2016-05-01

    The parasitic mite Varroa destructor is a major pest of the western honeybee, Apis mellifera. The development of acaricide resistance in Varroa populations is a global issue. Discriminating concentrations of acaricides are widely used to detect pest resistance. Two methods, using either glass vials or paraffin capsules, are used to screen for Varroa resistance to various acaricides. We found the glass vial method to be useless for testing Varroa resistance to acaridices, so we developed a polypropylene vial bioassay. This method was tested on tau-fluvalinate-, acrinathrin-, and amitraz-resistant mite populations from three apiaries in Czechia. Acetone was used as a control and technical grade acaricide compounds diluted in acetone were applied to the polypropylene vials. The solutions were spread on the vial surface by rolling the vial, and were then evaporated. Freshly collected Varroa females were placed in the vials and the mortality of the exposed mites was measured after 24 h. The Varroa populations differed in mortality between the apiaries and the tested compounds. Mites from the Kyvalka site were resistant to acrinathrin, tau-fluvalinate, and amitraz, while mites from the Postrizin site were susceptible to all three acaricides. In Prelovice apiary, the mites were susceptible to acrinathrin and amitraz, but not to tau-fluvalinate. The calculated discriminating concentrations for tau-fluvalinate, acrinathrin, and amitraz were 0.66, 0.26 and 0.19 µg/mL, respectively. These results indicate that polyproplyne vial tests can be used to determine discriminating concentrations for the early detection of acaricide resistant Varroa. Finally, multiple-resistance in Kyvalka may indicate metabolic resistance.

  18. Auditorías viales e intervenciones para prevenir atropellamientos, Cuernavaca, México, 2010

    Directory of Open Access Journals (Sweden)

    Martha Híjar M.

    2014-09-01

    Full Text Available Resumen Los atropellamientos son un problema de Salud Pública en México. Representan más del 40% de las muertes reportadas como lesiones causadas por el tránsito (lct. En zonas urbanas representan hasta el 60% de las lct. Objetivo: caracterizar y analizar algunas zonas donde se concentraban tanto las muertes como los lesionados por atropellamiento en Cuernavaca, México. Metodología: desde un estudio descriptivo-retrospectivo se planearon y ejecutaron auditorías viales sobre las intersecciones que habían representado mayor riesgo de lesiones y muertes en peatones. En cada lugar se evaluó el aforo peatonal, vehicular, los ciclos semafóricos, las condiciones del medio ambiente físico y se tomaron archivos fotográficos. Resultados: se observó deficiencia de elementos del medio ambiente físico: señalamientos desgastados sobre y al costado de la vía, mala visibilidad por ramas de árboles, vehículos estacionados indebidamente, paradas no autorizadas de transporte público, no uso de puentes peatonales y ciclos semafóricos deficientes. Conclusión: las auditorías viales son herramientas procedentes y empleadas en la ingeniería del tránsito, poco usadas por los salubristas como técnicas para prevenir LCT, en especial atropellamientos. Permiten diseñar e implementar medidas de prevención primaria para disminuir los riesgos de lesión en los usuarios más vulnerables de la vía pública: los peatones. Abstract Pedestrian injuries are a public health problem in Mexico.Represent more than 40% of the deaths reported as road traffic injuries (rti. Likewise, they represent up to 60% of all RTIs in urban areas. Objective: To characterize and analyze the areas with a high incidence of fatal and non-fatal pedestrian injuries in Cuernavaca, Mexico. Methodology: a retrospective descriptive study in which street audits were conducted on the intersections with the highest risk of pedestrian fatality and injury. Pedestrian and vehicle equipment

  19. Criterios de cuantificación indemnizatoria en accidentalidad vial: una ítica judicial

    Directory of Open Access Journals (Sweden)

    Marcela Pantoja Echeverri

    2010-12-01

    Full Text Available La accidentalidad vial, es la segunda causa de muerte violenta en Colombia, fuente de daños materiales y morales en las personas. Las normas de responsabilidad civil obligan al propietario o conductor a responder civil y penalmente por sus consecuencias. El problema de accidentalidad y de la cuantificación de indemnizaciones, reviste gran interés por el alto número de procesos que por homicidios en accidentes de tránsito cursan en el Distrito Judicial de Cali. En la investigación realizada en la Escuela de Ingeniería Estadística de la Universidad del Valle, se efectuó recolección de expedientes y se aplicó una encuesta de tipo cuestionario para indagar sobre la política judicial que se usó en el cálculo de indemnizaciones en Juzgados Penales del Circuito de Cali, donde se observa gran disparidad en los criterios de reparación. Tampoco se contempla un modelo estándar para cuantificar los perjuicios tanto materiales como morales y no hay evidencia de una política baremada; por tanto, el estudio intenta brindar un marco de referencia para proponer a Jueces y Fiscales, un modelo de regresión múltiple en el cual se consideran características socioeconómicas de víctimas, perjudicados y procesados, con el fin de unificar criterios de cuantificación que fijen el monto de la reparación económica a los perjudicados, sus herederos. El modelo resultante propone criterios utilizados por las compañías de seguros para fijar las primas de seguro de vida, tales como: el tiempo de vida y el nivel de ingresos del occiso, y responsabilidades con su grupo familiar.

  20. High Efficiency Centrifugal Compressor for Rotorcraft Applications

    Science.gov (United States)

    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

  1. Implementation of centrifuge testing of expansive soils for pavement design.

    Science.gov (United States)

    2017-03-01

    The novel centrifuge-based method for testing of expansive soils from project 5-6048-01 was implemented into : use for the determination of the Potential Vertical Rise (PVR) of roadways that sit on expansive subgrades. The : centrifuge method was mod...

  2. Determination of {sup 226}Ra by gamma spectrometry: study of packaging vial of sample for analysis; Determinacao de {sup 226}Ra por espectrometria gama: estudo do recipiente de acondicionamento de amostra para analise

    Energy Technology Data Exchange (ETDEWEB)

    Carneiro, Andre Cavalcanti

    2015-07-01

    Determination of radioactivity levels of {sup 226}Ra by gamma spectrometry in a sample is based on measurements of {sup 214}Pb and {sup 214}Bi, daughters of {sup 222}Rn. Because radon is a gas, it can leak from the sample vial or accumulate on the upper empty it. If the vial has any crack, there will be loss of gas, which will cause error in determining the {sup 226}Ra concentration. One possible cause of cracks in the vials, that houses standards and samples, is the radiolysis action in the vial material, usually a polymer. As the demand {sup 226}Ra analysis in different matrices (geological samples, food, plants, etc.) is increasing, it was decided to study some polymer vials available on the market, to verify the feasibility to be used when is applied the analysis method using gamma spectrometry. Four types of polymer vials have been studied. The radiation doses in walls of the vials caused by natural radionuclides present in the sample were simulated using gamma irradiation. Tests, such as compressive strength test and tightness, were applied to the irradiated and non-irradiated vials. First, to verify the effect of radiolysis on the vial material and also if there was {sup 222}Rn diffusion in their walls. These preliminary results pointed out that the acrylic vials are the best option of packaging samples for analysis. This study should be repeated in a larger number of samples for a better evaluation. (author)

  3. Recent advances in centrifugal contactors design

    Energy Technology Data Exchange (ETDEWEB)

    Leonard, R.A.

    1987-10-01

    Advances in thedesign of the Argonne centrifugal contactor for solvent extaction are being realized as these contactors are built, tested, and used to implement the TRUEX process for the cleanup of nuclear waste liquids. These advances include (1) using off-the-shelf, face-mounted motors, (2) modifying the contractor so that relatively volatile solvents can be used, (3) adding a high-level liquid detector that can be used to alert the plant operator of process upsets, (4) providing secondary feed ports, (5) optimizing support frame design, (6) maintaining a linear design with external interstage lines so the stages can be allocated as needed for extraction, scrub, strip, and solvent cleanup operations, and (7) developing features that facilitate contractor operation in remote facilities. 11 refs., 8 figs.

  4. Head pulsations in a centrifugal pump

    Science.gov (United States)

    Boiko, V. S.; Sotnyk, M. I.; Moskalenko, V. V.

    2017-08-01

    This article investigated the factors, which affect to the character of the head pulsations of a centrifugal pump. We investigated the dependence of the shape and depth of these pulsations from the operation mode of the pump. Was determined, that the head pulsations at the outlet of the impeller (pulsations on the blade passing frequency) cause head pulsations at the outlet of the pump, that have the same frequency, but differ in shape and depth. These pulsations depend on the design features of the flow-through part of the pump (from the ratio of hydraulic losses on the friction and losses on the vortex formation). A feature of the researches that were conducted is also the using of not only hydraulic but also electric modeling methods. It allows determining the values of the components of hydraulic losses.

  5. Use of a centrifugal bioreactor for cartilaginous tissue formation from isolated chondrocytes.

    Science.gov (United States)

    Detzel, Christopher J; Van Wie, Bernard J

    2011-01-01

    Although a centrifugal bioreactor (CCBR) supports high-density mammalian suspension cell cultures by balancing drag, buoyancy, and centrifugal forces, to date anchorage-dependent cultures have not been tried. Also, steady or intermittent hydrostatic pressures of 8 to 500 kPa, and shears of 0.02 to 1.4 N/m(2) can be simultaneously applied in the CCBR. This article demonstrates the use of a CCBR to stimulate chondrogenesis in a high-density culture. At 3 weeks, histological results show even distribution of glycosaminoglycan (GAG) and collagen, with 1,890 ± 270 cells/mm(2) cell densities that exceed those of 1,470 ± 270 in pellet cultures. Analysis of collagen content reveals similar levels for all treatment groups; 6.8 ± 3.5 and 5.0 ± 0.4 μg collagen/μg DNA for 0.07 and 0.26 MPa CCBR cultures, respectively, in contrast to 6.6 ± 1.9 values for control pellet cultures. GAG levels of 5.6 ± 1.5 and 4.1 ± 0.9 μg GAG /μg DNA are present for cultures stressed at 0.07 and 0.26 MPa, respectively, in comparison to control pellet cultures at the 8.4 ± 0.9 level. Although results to date have not revealed mechanical stress combinations that stimulate chondrogenesis over unstressed controls, system advantages include continuous culture at cell densities above those in the pellet, precise medium control, the ability to independently vary multiple mechanical stresses over a broad range, and the flexibility for integration of scaffold features for future chondrogenesis stimulation studies. Copyright © 2011 American Institute of Chemical Engineers (AIChE).

  6. Multiphase flow modeling in centrifugal partition chromatography.

    Science.gov (United States)

    Adelmann, S; Schwienheer, C; Schembecker, G

    2011-09-09

    The separation efficiency in Centrifugal Partition Chromatography (CPC) depends on selection of a suitable biphasic solvent system (distribution ratio, selectivity factor, sample solubility) and is influenced by hydrodynamics in the chambers. Especially the stationary phase retention, the interfacial area for mass transfer and the flow pattern (backmixing) are important parameters. Their relationship with physical properties, operating parameters and chamber geometry is not completely understood and predictions are hardly possible. Experimental flow visualization is expensive and two-dimensional only. Therefore we simulated the flow pattern using a volume-of-fluid (VOF) method, which was implemented in OpenFOAM®. For the three-dimensional simulation of a rotating FCPC®-chamber, gravitational centrifugal and Coriolis forces were added to the conservation equation. For experimental validation the flow pattern of different solvent systems was visualized with an optical measurement system. The amount of mobile phase in a chamber was calculated from gray scale values of videos recorded by an image processing routine in ImageJ®. To visualize the flow of the stationary phase polyethylene particles were used to perform a qualitative particle image velocimetry (PIV) analysis. We found a good agreement between flow patterns and velocity profiles of experiments and simulations. By using the model we found that increasing the chamber depth leads to higher specific interfacial area. Additionally a circular flow in the stationary phase was identified that lowers the interfacial area because it pushes the jet of mobile phase to the chamber wall. The Coriolis force alone gives the impulse for this behavior. As a result the model is easier to handle than experiments and allows 3D prediction of hydrodynamics in the chamber. Additionally it can be used for optimizing geometry and operating parameters for given physical properties of solvent systems. Copyright © 2011 Elsevier B

  7. Reciprocating flow-based centrifugal microfluidics mixer

    Science.gov (United States)

    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. Vaccine vial monitor availability and use in low- and middle-income countries: A systematic review.

    Science.gov (United States)

    Eriksson, Pär; Gessner, Bradford D; Jaillard, Philippe; Morgan, Christopher; Le Gargasson, Jean Bernard

    2017-04-19

    The vaccine vial monitor (VVM) registers cumulative heat exposure on vaccines over time. As low- and lower-middle-income countries transition beyond support from the Global Alliance for Vaccines and Immunization (Gavi), they will assume full responsibility for vaccine financing and procurement. It is unclear to what extent countries transitioning out of Gavi support will continue to include VVMs on their vaccines. This paper aims to systematically review evidence on VVM availability and use in low- and middle-income countries to document factors behind global access to and country demand for VVMs. Such results could help identify actions needed to ensure continued use of VVMs in countries that transition out of Gavi support. We performed a systematic review of electronic databases, reference lists, and grey literature in English and French languages with publication dates from 2005 onwards. The studies included were analyzed for the following outcomes: (1) availability and deployment of VVM-labeled vaccines; (2) VVM practices and perceptions in the immunization system; (3) vaccine introduction and decision-making processes; (4) Gavi graduation and vaccine program sustainability. The study found that VVM availability and use was affected by multiple sourcing of vaccines and the extent to which VVM was included in the vaccine specification in the tendering documents when procuring vaccines. Knowledge about VVM and its impact on the EPI program was found to be high among health workers as well as decision-makers. However, the study also found that weak capacity in key national institutions such as NRA and NPA might impact on demand for VVM. As countries take decisions regarding the adoption of new vaccines, factors such as disease burden and vaccine price may assume greater importance than vaccine characteristics and presentation. Finally, the study found that countries rely largely on the advice and recommendations from technical partners such as WHO and PAHO. The

  9. Determination of moisture content in lyophilized mannitol through intact glass vials using NIR micro-spectrometers

    Directory of Open Access Journals (Sweden)

    Cristian Rodrigo Muzzio

    2011-06-01

    Full Text Available Determination of moisture content in lyophilized solids is fundamental to predict quality and stability of freeze-dried products, but conventional methods are time-consuming, invasive and destructive. The aim of this study was to develop and optimize a fast, inexpensive, noninvasive and nondestructive method for determination of moisture content in lyophilized mannitol, based on an NIR micro-spectrometer instead of a conventional NIR spectrometer. Measurements of lyophilized mannitol were performed through the bottom of rotating glass vials by means of a reflectance probe. The root mean standard error of prediction (RMSEP and the correlation coefficient (R²pred, yielded by the pre-treatments and calibration method proposed, was 0.233% (w/w and 0.994, respectively.A determinação do conteúdo de umidade em sólidos liofilizados é fundamental para se prever a qualidade e a estabilidade de produtos liofilizados, mas os métodos convencionais consomem muito tempo, são invasivos e destrutivos. O objetivo desse estudo foi desenvolver e otimizar um método rápido, econômico, não invasivo e não destrutivo para a determinação do conteúdo de umidade em manitol liofilizado, com base em microespectrômetro de infravermelho próximo ao invés de um espectrômetro de infravermelho próximo convencional. As medidas de manitol liofilizado foram realizadas através do fundo de recipiente de vidro em rotação por meio de sonda de reflectância. A raíz do erro médio padrão de predição (RMSEP e o coeficiente de correlação (R²pred obtidos pelo prétratamento e pelo método de calibração proposto foram, respectivamente, 0,233% (p/p e 0,994.

  10. A straight path centrifugal blood pump concept in the Capiox centrifugal pump.

    Science.gov (United States)

    Kijima, T; Oshiyama, H; Horiuchi, K; Nogawa, A; Hamasaki, H; Amano, N; Nojiri, C; Fukasawa, H; Akutsu, T

    1993-07-01

    This article describes comparative studies of a newly developed "straight path" centrifugal pump (Capiox centrifugal pump) targeted for open-heart surgery and circulatory support. A unique straight path design of the rotor was very effective in reducing the pump's rotational speed and prime volume. This pump was evaluated for hydraulics, hemolysis, depriming characteristics, cavitation, and heat generation. Two commercially available centrifugal pumps, the Biomedicus cone-type pump and the Sarns 3M impeller-type pump, were used as controls. The new pump required the lowest pump speed to produce the same flow rates under the same pressure loads and demonstrated the lowest hemolysis and the lowest temperature rise with the outlet clamped. The air volume required to deprime the new pump was one-third to one-half that for the other pumps, and no sign of cavitation was observed even if a small amount of air was introduced to the pump inlet under a negative pressure of 200 mm Hg.

  11. Bienestar psicológico y conductas de riesgo vial en jóvenes universitarios/as

    OpenAIRE

    Govillard, L.; Herrero, D.; Jáuregui, P.; Iraurgi, I.; Gorbeña, S.

    2017-01-01

    Introducción: El riesgo vial asociado con la velocidad y con el consumo de alcohol y drogas, y su relación con problemas de salud mental ha sido ampliamente investigado en la población universitaria. Existen, sin embargo, otras conductas de riesgo como la falta de uso del cinturón de seguridad o del casco que han sido menos estudiadas. El objetivo ha sido analizar la relación entre estos indicadores y el bienestar psicológico. Material y método: Se encuestó, de forma voluntaria y anónima, a 3...

  12. Comparative analysis of ampoules and vials in sterile and conventional packaging as to microbial load and sterility test.

    Science.gov (United States)

    Freitas, Raphael Ribeiro de Aquino; Tardelli, Maria Angela

    2016-05-24

    To compare sterility and microbial (bacteria and fungi) load in the outer part of hyperbaric bupivacaine (Neocaína®) in ampoule and bupivacaine in vial, in conventional and sterile pack formulations. The sterile packs were divided into two groups: G1 (n=16) with ampoules and G2 (n=16) with vials. Conventional formulations were divided into two groups, being G3 (n=16) with ampoules and G4 (n=16) with vials. The ampoules and vials were opened and had their content drawn. The empty bottles were then placed in sterile plastic bags and sent for analysis of microbial load (bacteria and fungi) and sterility testing. Data were analyzed using the χ2 test with Yates correction, and 95% confidence interval. G1 and G2 showed no bacterial growth when compared to conventional groups (pfungos) da parte externa dos frascos de envasamento de bupivacaína hiperbárica (Neocaína®) em ampola e bupivacaína em frasco-ampola das apresentações convencional e estéril (sterile pack). As apresentações estéreis (sterile pack) foram distribuídas em dois grupos, sendo que o G1 (n=16) continha as ampolas e o G2 (n=16), os frascos-ampola. As apresentações convencionais foram distribuídas em dois grupos, a saber G3 (n=16) com as ampolas e G4 (n=16) com os frascos-ampola. As ampolas e os frascos-ampolas eram abertos e tinham seu conteúdo aspirado. Os frascos vazios eram, então, acondicionados em sacos plásticos estéreis e enviados para análise quanto à carga microbiana (bactérias e fungos), bem como para o teste de esterilidade. Os dados foram analisados por meio do teste χ2 com correção Yates com intervalo de confiança de 95%. Os grupos G1 e G2 não apresentaram crescimento bacteriano quando comparado aos grupos convencionais (pfungos em nenhum dos grupos. O uso de embalagens estéreis (sterile pack) diminui a carga microbiana dos frascos de envasamentos, o que diminuiria a chance de exposição a uma potencial contaminação da solução anestésica.

  13. Delitos contra la seguridad vial. La Agrupación de Tráfico de la Guardia Civil

    OpenAIRE

    Rosa Carbajo, Jorge Juan de la

    2015-01-01

    El crecimiento económico, los avances tecnológicos y el estilo de vida nos conducen a una movilidad creciente. En esta hodierna violencia vial que sufrimos "in crescendo" en la actualidad, el infractor se convierte en un enemigo para la sociedad, en donde el conductor se percibe como fuente de peligro, la víctima encarnada en protagonista inocente, y la conducción "per se" como una conducta peligosa y arriesgada. Lo que en otros pretéritos tiempos se consideraba por todos la fórmula CONDUCCIÓ...

  14. Performance analysis of mini centrifugal pump with splitter blades

    Science.gov (United States)

    Shigemitsu, T.; Fukutomi, J.; Wada, T.; Shinohara, H.

    2013-12-01

    Design method for a mini centrifugal pump is not established because the internal flow condition for these small-sized fluid machines is not clarified and conventional theory is not suitable for small-sized pumps. Then, a semi-open impeller for the mini centrifugal pump with 55mm impeller diameter is adopted in this research to take simplicity and maintenance into consideration. Splitter blades are adopted in this research to improve the performance and internal flow condition of mini centrifugal pump having large blade outlet angle. The performance tests are conducted with these rotors in order to investigate the effect of the splitter blades on the performance and internal flow condition of the mini centrifugal pump. A three dimensional steady numerical flow analysis is conducted to analyze rotor, volute efficiency and loss caused by a vortex. It is clarified from the experimental results that the performance of the mini centrifugal pump is improved by the effect of the splitter blades. Flow condition at outlet of the rotor becomes uniform and back flow regions are suppressed in the case with the splitter blades. Further, the volute efficiency increases and the vortex loss decreases. In the present paper, the performance of the mini centrifugal pump is shown and the flow condition is clarified with the results of the experiment and the numerical flow analysis. Furthermore, the performance analyses of the mini centrifugal pumps with and without the splitter blades are conducted.

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

    Energy Technology Data Exchange (ETDEWEB)

    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)

  16. Centrifugal Spinning and Its Energy Storage Applications

    Science.gov (United States)

    Yao, Lu

    -/micro-fiber production method to substitute electrospinning in industrial production. Recently, centrifugal spinning has gained researchers' attention. The centrifugal spinning method avoids the use of high voltage supply and can work with concentrated solutions, and most importantly, it can increase the production rate of nano-/micro-fibers to at least two orders or magnitude higher than that of electrospinning. This novel fiber fabrication approach is mostly used in tissue engineering field, and it can be potentially applied in preparing electrodes for SIBs and EDLCs. In the present work, we firstly study the influence of solution intrinsic properties and operational parameters using polyacrylonitrile as an example, and establish the processing-structure relationships for this spinning technique. We then use this novel spinning method to prepare porous carbon nanofibers (PCNFs), SnO2 microfibers and lithium-substituted sodium layered transition metal oxide fibers and use them as electrodes for EDLCs and SIBs. The as-prepared PCNFs, SnO2 microfibers and lithiumsubstituted sodium layered transition metal oxide fibers exhibit good electrochemical performance. It is therefore demonstrated that centrifugal spinning can be a promising nano- /micro-fiber preparation approach for mass production of electrode materials used in energy storage applications.

  17. Centrifugal Size-Separation Sieve for Granular Materials

    Science.gov (United States)

    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.

  18. Separation of Nanoparticles in Aqueous Multiphase Systems through Centrifugation

    KAUST Repository

    Akbulut, Ozge

    2012-08-08

    This paper demonstrates the use of aqueous multiphase systems (MuPSs) as media for rate-zonal centrifugation to separate nanoparticles of different shapes and sizes. The properties of MuPSs do not change with time or during centrifugation; this stability facilitates sample collection after separation. A three-phase system demonstrates the separation of the reaction products (nanorods, nanospheres, and large particles) of a synthesis of gold nanorods, and enriches the nanorods from 48 to 99% in less than ten minutes using a benchtop centrifuge. © 2012 American Chemical Society.

  19. Anomalous Centrifugal Distortion in NH_2

    Science.gov (United States)

    Martin-Drumel, Marie-Aline; Pirali, Olivier; Coudert, L. H.

    2017-06-01

    The NH2 radical spectrum, first observed by Herzberg and Ramsay, is dominated by a strong Renner-Teller effect giving rise to two electronic states: the bent X ^{2}B_1 ground state and the quasi-linear A ^{2}A_1 excited state. The NH2 radical has been the subject of numerous high-resolution investigations and its electronic and ro-vibrational transitions have been measured. Using synchrotron radiation, new rotational transitions have been recently recorded and a value of the rotational quantum number N as large as 26 could be reached. In the X ^{2}B_1 ground state, the NH2 radical behaves like a triatomic molecule displaying spin-rotation splittings. Due to the lightness of the molecule, a strong coupling between the overall rotation and the bending mode arises whose effects increase with N and lead to the anomalous centrifugal distortion evidenced in the new measurements.^d In this talk the Bending-Rotation approach developed to account for the anomalous centrifugal distortion of the water molecule is modified to include spin-rotation coupling and applied to the fitting of high-resolution data pertaining to the ground electronic state of NH2. A preliminary line position analysis of the available data^{c,d} allowed us to account for 1681 transitions with a unitless standard deviation of 1.2. New transitions could also be assigned in the spectrum recorded by Martin-Drumel et al.^d In the talk, the results obtained with the new theoretical approach will be compared to those retrieved with a Watson-type Hamiltonian and the effects of the vibronic coupling between the ground X ^{2}B_1 and the excited A ^{2}A_1 electronic state will be discussed. Herzberg and Ramsay, J. Chem. Phys. 20 (1952) 347 Dressler and Ramsay, Phil. Trans. R. Soc. A 25 (1959) 553 Hadj Bachir, Huet, Destombes, and Vervloet, J. Molec. Spectrosc. 193 (1999) 326 McKellar, Vervloet, Burkholder, and Howard, J. Molec. Spectrosc. 142 (1990) 319 Morino and Kawaguchi, J. Molec. Spectrosc. 182 (1997) 428

  20. El impacto de las nuevas políticas de seguridad vial sobre la conducta de los conductores

    Directory of Open Access Journals (Sweden)

    Jordi Tena-Sánchez

    2013-04-01

    Full Text Available La evidencia empírica disponible señala de manera unánime que las nuevas políticas de tráfico y seguridad vial aplicadas en España desde 2004, y en particular la introducción del carné por puntos y la reforma del Código Penal, han tenido una fuerte incidencia positiva en la reducción de la siniestralidad. De dichos resultados se deriva que las nuevas políticas han tenido también un efecto positivo sobre la conducta de los conductores, de modo que ha sido esa mejora en la conducta al volante la que finalmente se ha traducido en una reducción de la siniestralidad. No obstante, hasta el momento, los investigadores han descuidado el análisis directo de los datos sobre cumplimiento. En el presente trabajo se analizan todos los datos disponibles que ofrecen información sobre el cumplimiento de la normativa de tráfico y seguridad vial.

  1. Rational designing of multistage centrifugal pumps

    Energy Technology Data Exchange (ETDEWEB)

    Grokhovskii, D.V.

    1984-07-01

    This article considers a more rational approach to the increase of the rigidity of a rotor for a multistage centrifugal pump (MCP), which will enable a more rational design of the entire pump. An important problem in modern pump designing is the dynamic strength of the rotors of high-pressure MCPs. An equation is presented for the calculation of the hydrostatic forces in the slit seals between the stages (SSBS) of the MCP rotors, which increase the rigidity of the rotor. It is determined that the length of the SSBS decreases with increasing finishing roughness. The existence of a close relationship between the operational and the variable design parameters allow the computer-aided design of MCPs. It is concluded that the optimum mass, dimension, and vibroacoustic characteristics for high-pressure MCPs depend on the minimum radial gaps in the rotor seals, and the stages should not exceed four. The modern tendency in worldwide pump design is to significantly reduce the number of stages of high-pressure MCP for large power plants.

  2. More quantum centrifugal effect in rotating frame

    Science.gov (United States)

    Gazeau, J.-P.; Koide, T.; Murenzi, R.

    2017-06-01

    The behaviour of quantum systems in non-inertial frames is revisited from the point of view of affine coherent state (ACS) quantization. We restrict our approach to the one-particle dynamics confined in a rotating plane about a fixed axis. This plane is considered as punctured due to the existence of the rotation center, which is viewed as a singularity. The corresponding phase space is the affine group of the plane and the ACS quantization enables us to quantize the system by respecting the affine symmetry of the true phase space. Our formulation predicts the appearance of an additional quantum centrifugal term, besides the usual angular-momentum one, which prevents the particle to reach the singular rotation center. Moreover it helps us to understand why two different non-inertial Schrödinger equations are obtained in previous works. The validity of our equation can be confirmed experimentally by observing the harmonic oscillator bound states and the critical angular velocity for their existence.

  3. Effect of sludge behavior on performance of centrifugal contactor

    Energy Technology Data Exchange (ETDEWEB)

    Sakamoto, A.; Sano, Y.; Takeuchi, M. [Japan Atomic Energy Agency - JAEA, 4-33 Muramatsu Tokai-mura Naka-gun Ibaraki-pref. 319-1194 (Japan)

    2016-07-01

    The Japan Atomic Energy Agency has been developing an annular centrifugal contactor for solvent extraction in spent fuel reprocessing, which allows the mixing of aqueous and organic phases in the annular area and their separation from the mixed phase in the rotor. The effects of sludge behavior on the performance of a centrifugal contactor were investigated. Sludge accumulation during the operation of the centrifugal contactor was observed only in the rotor. Based on the sludge accumulation behavior, the effects of rotor sludge accumulation on the performance of phase separation and extraction were investigated using several types of rotors, which simulated different sludge accumulation levels in the separation area. It was confirmed that rotor sludge accumulation would affect the phase separation performance but not the extraction performance. This can be explained by the structure of the centrifugal contactor, wherein the extraction reaction and phase separation mainly proceed in the housing and rotor, respectively.

  4. Centrifuge Modelling of Two Civil-Environmental Problems

    National Research Council Canada - National Science Library

    Goodings, Deborah

    2001-01-01

    Research Problem 1: Frost heave and thaw induced settlement in silt and silty clay developing over a year have been modelled correctly using a geotechnical centrifuge with tests requiring less than a day...

  5. Confusion around the tidal force and the centrifugal force

    CERN Document Server

    Matsuda, Takuya; Boffin, Henri M J

    2015-01-01

    We discuss the tidal force, whose notion is sometimes misunderstood in the public domain literature. We discuss the tidal force exerted by a secondary point mass on an extended primary body such as the Earth. The tidal force arises because the gravitational force exerted on the extended body by the secondary mass is not uniform across the primary. In the derivation of the tidal force, the non-uniformity of the gravity is essential, and inertial forces such as the centrifugal force are not needed. Nevertheless, it is often asserted that the tidal force can be explained by the centrifugal force. If we literally take into account the centrifugal force, it would mislead us. We therefore also discuss the proper treatment of the centrifugal force.

  6. Zero-ODP Refrigerants for Low Tonnage Centrifugal Chiller Systems

    National Research Council Canada - National Science Library

    Gui, Fulin

    1996-01-01

    ..., HFC-236cb, HFC-236fa, HFC-245cb, and HFC-254cb, for centrifugal chiller applications. We took into account the thermodynamic properties of the refrigerant and aerodynamic properties of the impeller compression process to this evaluation...

  7. DEM simulation of granular flows in a centrifugal acceleration field

    Science.gov (United States)

    Cabrera, Miguel Angel; Peng, Chong; Wu, Wei

    2017-04-01

    The main purpose of mass-flow experimental models is abstracting distinctive features of natural granular flows, and allow its systematic study in the laboratory. In this process, particle size, space, time, and stress scales must be considered for the proper representation of specific phenomena [5]. One of the most challenging tasks in small scale models, is matching the range of stresses and strains among the particle and fluid media observed in a field event. Centrifuge modelling offers an alternative to upscale all gravity-driven processes, and it has been recently employed in the simulation of granular flows [1, 2, 3, 6, 7]. Centrifuge scaling principles are presented in Ref. [4], collecting a wide spectrum of static and dynamic models. However, for the case of kinematic processes, the non-uniformity of the centrifugal acceleration field plays a major role (i.e., Coriolis and inertial effects). In this work, we discuss a general formulation for the centrifugal acceleration field, implemented in a discrete element model framework (DEM), and validated with centrifuge experimental results. Conventional DEM simulations relate the volumetric forces as a function of the gravitational force Gp = mpg. However, in the local coordinate system of a rotating centrifuge model, the cylindrical centrifugal acceleration field needs to be included. In this rotating system, the centrifugal acceleration of a particle depends on the rotating speed of the centrifuge, as well as the position and speed of the particle in the rotating model. Therefore, we obtain the formulation of centrifugal acceleration field by coordinate transformation. The numerical model is validated with a series of centrifuge experiments of monodispersed glass beads, flowing down an inclined plane at different acceleration levels and slope angles. Further discussion leads to the numerical parameterization necessary for simulating equivalent granular flows under an augmented acceleration field. The premise of

  8. Centrifuging Step-Screw Conveyor for Regolith Project

    Data.gov (United States)

    National Aeronautics and Space Administration — A variety of ISRU operations will utilize lunar regolith as feedstock. The proposed centrifuging step-screw conveyor concept will provide a well controlled robust,...

  9. Centrifuge Facility for the International Space Station Alpha

    Science.gov (United States)

    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

  10. Ultra scale-down prediction using microwell technology of the industrial scale clarification characteristics by centrifugation of mammalian cell broths.

    Science.gov (United States)

    Tait, A S; Aucamp, J P; Bugeon, A; Hoare, M

    2009-10-01

    solids remaining after centrifugation rate provide insight into the state of the cells throughout the fermentation and the ease with which they and accumulated debris may be removed by continuous centrifugation. Hence bioprocess data are more readily available to help better integrate cell culture and cell removal stages and resolve key bioprocess design issues such as choice of time of harvesting and the impact on product yield and contaminant carry over. Operation at microwell scale allows data acquisition and bioprocess understanding over a wide range of operating conditions that might not normally be achieved during bioprocess development. (c) 2009 Wiley Periodicals, Inc.

  11. The vacancies formation and agglomeration under centrifugal force

    Science.gov (United States)

    Wierzba, Bartek

    2017-10-01

    In this paper the vacancies formation and agglomeration under centrifugal force - sedimentation will be analyzed. The evolutionary algorithm for diffusion and vacancy evolution will be shown. The model predicts the location of vacancies agglomeration during the sedimentation process - the most probably place of voids formation. The computed results will be compared with experiments in Cu-brass diffusion couple. The influence of the centrifugal force on the vacancies migration will be presented.

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

    Science.gov (United States)

    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

  13. Synthesis and Analytical Centrifugation of Magnetic Model Colloids

    OpenAIRE

    Luigjes, B.

    2012-01-01

    This thesis is a study of the preparation and thermodynamic properties of magnetic colloids. First, two types of magnetic model colloids are investigated: composite colloids and single-domain nanoparticles. Thermodynamics of magnetic colloids is studied using analytical centrifugation, including a specially adapted centrifuge for measuring heavy and strongly light absorbing colloids. Magnetic composite colloids can be prepared from thermodynamically stable Pickering emulsions of 3-methacrylox...

  14. Efectividad de las campañas de publicidad para reducir la siniestralidad vial en España: un análisis econométrico

    OpenAIRE

    Castillo Manzano, José I.; Castro Nuño, Mercedes; Pedregal Tercero, Diego José

    2011-01-01

    A principios del siglo XXI, hemos asistido a un endurecimiento considerable de las estrategias de prevención y sanción aplicadas por la Administración española en materia de seguridad vial, con objeto de lograr una reducción en los accidentes de tráfico. Este endurecimiento puede apreciarse de manera particular, en las campañas públicas de publicidad vial dirigidas a los diferentes medios de comunicación, a través de un cambio profundo en el diseño de los mensajes emitidos, pas...

  15. Application of CFD in Bioprocessing: Separation of mammalian cells using disc stack centrifuge during production of biotherapeutics.

    Science.gov (United States)

    Shekhawat, Lalita Kanwar; Sarkar, Jayati; Gupta, Rachit; Hadpe, Sandeep; Rathore, Anurag S

    2017-12-24

    Centrifugation continues to be one of the most commonly used unit operations for achieving efficient harvest of the product from the mammalian cell culture broth during production of therapeutic monoclonal antibodies (mAbs). Since the mammalian cells are known to be shear sensitive, optimal performance of the centrifuge requires a balance between productivity and shear. In this study, Computational Fluid Dynamics (CFD) has been successfully used as a tool to facilitate efficient optimization. Multiphase Eulerian-Eulerian model coupled with Gidaspow drag model along with Eulerian-Eulerian k-ε mixture turbulence model have been used to quantify the complex hydrodynamics of the centrifuge and thus evaluate the turbulent stresses generated by the centrifugal forces. An empirical model has been developed by statistical analysis of experimentally observed cell lysis data as a function of turbulent stresses. An operating window that offers the optimal balance between high productivity, high separation efficiency, and low cell damage has been identified by use of CFD modeling. Copyright © 2017 Elsevier B.V. All rights reserved.

  16. Stool Culture

    Science.gov (United States)

    ... dsDNA Anti-LKM-1 Anti-Müllerian Hormone Anti-Saccharomyces cerevisiae Antibodies (ASCA) Antibiotic Susceptibility Testing Anticentromere Antibody ... one that has been placed in a transport medium (a collection vial containing a preservative) Test Preparation ...

  17. Production of senescent cells of Saccharomyces cerevisiae by centrifugal elutriation.

    Science.gov (United States)

    Woldringh, C L; Fluiter, K; Huls, P G

    1995-04-15

    The centrifugal elutriator has been used as a baby machine by loading the chamber with a population of mixed-generation daughter cells and allowing this population to grow, divide and age under continuous washing-out of newborn daughter cells. Clear peaks in the number of elutriated cells were reproducibly obtained for at least ten generations. The parent cells growing in the chamber continued to divide at the steady-state generation time of 95-100 min, showing no change in cycle time during aging. The washed-out daughter cells increased in volume during the first five generations from their steady-state value of 17 micro3 to a maximum of 34 micro3. As to be expected, the generation times of these large daughters, determined in a synchronous batch culture, were shorter (130 min) than that of the steady-state daughters (240 min), even when derived from 15-generation parents. No indication for a volume increase of daughter cells without bud was observed when a population was allowed to grow in the chamber without washing-out the smaller daughter cells. The 15-generation parent population, recovered from the chamber, had an average volume of 80 micro3 and consisted of: (i) 71% cells with more than ten scars, (ii) 13% cells with one to nine scars, and (iii) 17% daughter cells. The production of senescent cells by undisturbed growth in the elutriator chamber has been prolonged to 29 generations. The method is therefore suitable to examine what factors determine the life span of budding yeast.

  18. Análisis de la seguridad vial en la región central de Cuba

    OpenAIRE

    García Depestre, René A; Domingo E. Delgado Martínez; Eduardo E. Díaz García

    2012-01-01

    La accidentalidad vehicular es un problema de salud mundial, lo que constituye la primera causa de muerte de niños y adultos jóvenes. Cuba no está exenta de esta situación y la provincia de Villa Clara, ubicada en la región central del país, está entre las primeras en el país en lo que se refiere a la inseguridad vial; por lo que es necesario analizar los factores que inciden en los accidentes a partir de la información contenida en los reportes de accidentes de tránsito. En este trabajo se c...

  19. Environmental Testing of Tritium-Phosphor Glass Vials for Use in Long-Life Radioisotope Power Conversion Units

    Science.gov (United States)

    Zemcov, Michael; Cardona, Pedro; Parkus, James; Patru, Dorin; Yost, Valerie

    2017-01-01

    Power generation in extreme environments, such as the outer solar system, the night side of planets, or other low-illumination environments, currently presents a technology gap that challenges NASA's ambitious scientific goals. We are developing a radioisotope power cell (RPC) that utilizes commercially available tritium light sources and standard 1.85 eV InGaP2 photovoltaic cells to convert beta particle energy to electric energy. In the test program described here, we perform environmental tests on commercially available borosilicate glass vials internally coated with a ZnS luminescent phosphor that are designed to contain gaseous tritium in our proposed power source. Such testing is necessary to ensure that the glass containing the radioactive tritium is capable of withstanding the extreme environments of launch and space for extended periods of time.

  20. Sensitivities, Specificities, and Predictive Values of Microbiological Culture Techniques for the Diagnosis of Prosthetic Joint Infection

    Directory of Open Access Journals (Sweden)

    Robert W. Jordan

    2014-01-01

    Full Text Available Background. Identifying the microorganism in a prosthetic joint infection is the key to appropriately targeting antimicrobial treatment. Despite the availability of various techniques, no single test is considered the definitive gold standard. Aim. Our aim was to determine the sensitivity, specificity, and positive/negative predictive values for a variety of culture techniques. Methods. We performed a retrospective case series of 219 patients undergoing revision surgery of their hip or knee replacement between May 2004 and February 2013. The patients were classified as either infected or noninfected according to criteria set out by the Musculoskeletal Infection Society. The number and type of samples taken intraoperatively varied between cases but included tissue samples and fluid sent in either blood culture vials or sterile containers. Results. The highest sensitivity was found with blood culture vials (0.85 compared to fluid in sterile containers (0.26 and tissues samples (0.32. Blood culture vials also had a better specificity and positive and negative predictive values profile. Conclusion. We conclude that, of the techniques studied, fluid in blood culture vials had the best profile for the correct identification of microorganisms and advocate its use.

  1. Sensitivities, Specificities, and Predictive Values of Microbiological Culture Techniques for the Diagnosis of Prosthetic Joint Infection

    Science.gov (United States)

    Jordan, Robert W.; Smith, Nicholas A.; Sprowson, Andrew P.

    2014-01-01

    Background. Identifying the microorganism in a prosthetic joint infection is the key to appropriately targeting antimicrobial treatment. Despite the availability of various techniques, no single test is considered the definitive gold standard. Aim. Our aim was to determine the sensitivity, specificity, and positive/negative predictive values for a variety of culture techniques. Methods. We performed a retrospective case series of 219 patients undergoing revision surgery of their hip or knee replacement between May 2004 and February 2013. The patients were classified as either infected or noninfected according to criteria set out by the Musculoskeletal Infection Society. The number and type of samples taken intraoperatively varied between cases but included tissue samples and fluid sent in either blood culture vials or sterile containers. Results. The highest sensitivity was found with blood culture vials (0.85) compared to fluid in sterile containers (0.26) and tissues samples (0.32). Blood culture vials also had a better specificity and positive and negative predictive values profile. Conclusion. We conclude that, of the techniques studied, fluid in blood culture vials had the best profile for the correct identification of microorganisms and advocate its use. PMID:24963476

  2. Clinical and experimental study of autologous fat grafting after processing by centrifugation and serum lavage.

    Science.gov (United States)

    Khater, Regina; Atanassova, Pepa; Anastassov, Yorii; Pellerin, Philippe; Martinot-Duquennoy, Veronique

    2009-01-01

    This clinical and experimental study compared adipose tissue transplant behavior after two different techniques of purifying: centrifugation at 3400 rpm for 3 min and serum lavage without centrifugation. Clinical evaluation was performed under standardized conditions for lipofilling on a series of 51 female patients, intentionally selected to have similar characteristics and assigned to two groups based on the method of processing. Experimentally, a culture system in diffusion chambers with vitaline membranes was designed to mimic the behavior and to study the morphology of the adipose tissue used for autografting. Survival, structure, and proliferation of the adipose cells in vitro were examined by classical histologic H&E staining and immunohistochemistry for leptin and cyclin D1. The main differences encountered experimentally were the presence of a greater amount of preadipocytes in the noncentrifuged adipose tissue cultures and more distinctly expressed cell proliferation. The postoperative clinical results favored of the serum lavage purifying technique. Our data suggest that with transplantation of noncentrifuged adipose tissue more active preadipocytes are applied which could possibly lead to better potential chances of survival and even de novo development of fat.

  3. Monodisperse Multidimensional Nanostructures via Centrifugal Separation

    Science.gov (United States)

    Shin, Yu Jin

    Anisotropic nanomaterials, including zero-dimensional metallic nanoparticles (MNPs), one-dimensional single-walled carbon nanotubes (SWCNTs), and two-dimensional few-layer black phosphorous (FL-P) exhibit interesting structure-dependent properties that could be exploited in biomedicine, plasmonics, and optoelectronics. In this thesis, centrifugation sorting of these nanomaterials is utilized for structure refinement, investigation of structure-dependent optical response, and applications in biomedical imaging and plasmonics. Nobel NMPs show unique shape- and size-dependent optical properties. Controlled synthetic methods are developed to manipulate the structure of these NMPs, but intrinsically produce dispersions of polydisperse NPs with various shape and size, and synthetic byproducts. Here, we describe a facile strategy for separating small (edge length 80%) and subsequently achieve a 2.5 fold enhancement in refractive index sensitivity, comparable to the unsorted mixture. This shallow DGC approach is robust and reliable, and therefore can be applied to other metal nanostructures for concomitant improvements in plasmonic properties and applications. Using the identical separation strategy in the previous study, we are able to enrich gold nanostars as a function of branch number. In particular, we explore different variants of density gradient media to ensure compatibility with the star shape and colloid stability. We determine that sucrose is compatible with nanostars stability and surface functionalizaton. The refined population of gold stars are functionalized with Gd(III)-DNA to act as MRI contrast agents, and thus enables us to investigate how populations of nanostars with different branch numbers contribute to the relaxivity of surface bound Gd(III)-DNA. It is shown that the increased relaxivity of DNA-Gd star is correlated with increased number of star branches, not with increased size of the stars. Therefore, shape is a new parameter which can be tuned in

  4. The impact of the centrifuge characteristics and centrifugation protocols on the cells, growth factors, and fibrin architecture of a leukocyte- and platelet-rich fibrin (L-PRF) clot and membrane.

    Science.gov (United States)

    Dohan Ehrenfest, David M; Pinto, Nelson R; Pereda, Andrea; Jiménez, Paula; Corso, Marco Del; Kang, Byung-Soo; Nally, Mauricio; Lanata, Nicole; Wang, Hom-Lay; Quirynen, Marc

    2017-04-24

    -PRF. All centrifugations were done using the original L-PRF centrifuge (Intra-Spin), as recommended by the two manufacturers. Half of the membranes were placed individually in culture media and transferred in a new tube at seven experimental times (up to 7 days). The releases of transforming growth factor β-1 (TGFβ-1), platelet derived growth factor AB (PDGF-AB), vascular endothelial growth factor (VEGF) and bone morphogenetic protein 2 (BMP-2) were quantified using ELISA kits at these seven experimental times. The remaining membranes were used to evaluate the initial quantity of growth factors of the L-PRF and A-PRF membranes, through forcible extraction. Very significant differences in the level of vibrations at each rotational speed were observed between the four tested centrifuges. The original L-PRF centrifuge (Intra-Spin) was by far the most stable machine in all configurations and always remained under the threshold of resonance, unlike the three other tested machines. At the classical speed of production of L-PRF, the level of undesirable vibrations on the original centrifuge was between 4.5 and 6 times lower than with other centrifuges. Intra-Spin showed the lowest temperature of the tubes. A-PRF and Salvin were both associated with a significant increase in temperature in the tube. Intra-Spin produced the heaviest clot and quantity of exudate among the four techniques. A-PRF and LW produced much lighter, shorter and narrower clots and membranes than the two other centrifuges. Light microscopy analysis showed relatively similar features for all L-PRF types (concentration of cell bodies in the first half). However, SEM illustrated considerable differences between samples. The original Intra-Spin L-PRF showed a strongly polymerized thick fibrin matrix and all cells appeared alive with a normal shape, including the textured surface aspect of activated lymphocytes. The A-PRF, Salvin and LW PRF-like membranes presented a lightly polymerized slim fibrin gel and most

  5. Risk of Injection-Site Abscess among Infants Receiving a Preservative-Free, Two-Dose Vial Formulation of Pneumococcal Conjugate Vaccine in Kenya.

    Directory of Open Access Journals (Sweden)

    Deron C Burton

    Full Text Available There is a theoretical risk of adverse events following immunization with a preservative-free, 2-dose vial formulation of 10-valent-pneumococcal conjugate vaccine (PCV10. We set out to measure this risk. Four population-based surveillance sites in Kenya (total annual birth cohort of 11,500 infants were used to conduct a 2-year post-introduction vaccine safety study of PCV10. Injection-site abscesses occurring within 7 days following vaccine administration were clinically diagnosed in all study sites (passive facility-based surveillance and, also, detected by caregiver-reported symptoms of swelling plus discharge in two sites (active household-based surveillance. Abscess risk was expressed as the number of abscesses per 100,000 injections and was compared for the second vs first vial dose of PCV10 and for PCV10 vs pentavalent vaccine (comparator. A total of 58,288 PCV10 injections were recorded, including 24,054 and 19,702 identified as first and second vial doses, respectively (14,532 unknown vial dose. The risk ratio for abscess following injection with the second (41 per 100,000 vs first (33 per 100,000 vial dose of PCV10 was 1.22 (95% confidence interval [CI] 0.37-4.06. The comparator vaccine was changed from a 2-dose to 10-dose presentation midway through the study. The matched odds ratios for abscess following PCV10 were 1.00 (95% CI 0.12-8.56 and 0.27 (95% CI 0.14-0.54 when compared to the 2-dose and 10-dose pentavalent vaccine presentations, respectively. In Kenya immunization with PCV10 was not associated with an increased risk of injection site abscess, providing confidence that the vaccine may be safely used in Africa. The relatively higher risk of abscess following the 10-dose presentation of pentavalent vaccine merits further study.

  6. Risk of Injection-Site Abscess among Infants Receiving a Preservative-Free, Two-Dose Vial Formulation of Pneumococcal Conjugate Vaccine in Kenya

    Science.gov (United States)

    Burton, Deron C.; Bigogo, Godfrey M.; Audi, Allan O.; Williamson, John; Munge, Kenneth; Wafula, Jackline; Ouma, Dominic; Khagayi, Sammy; Mugoya, Isaac; Mburu, James; Muema, Shadrack; Bauni, Evasius; Bwanaali, Tahreni; Feikin, Daniel R.; Ochieng, Peter M.; Mogeni, Ondari D.; Otieno, George A.; Olack, Beatrice; Kamau, Tatu; Van Dyke, Melissa K.; Chen, Robert; Farrington, Paddy; Montgomery, Joel M.; Breiman, Robert F.; Scott, J. Anthony G.; Laserson, Kayla F.

    2015-01-01

    There is a theoretical risk of adverse events following immunization with a preservative-free, 2-dose vial formulation of 10-valent-pneumococcal conjugate vaccine (PCV10). We set out to measure this risk. Four population-based surveillance sites in Kenya (total annual birth cohort of 11,500 infants) were used to conduct a 2-year post-introduction vaccine safety study of PCV10. Injection-site abscesses occurring within 7 days following vaccine administration were clinically diagnosed in all study sites (passive facility-based surveillance) and, also, detected by caregiver-reported symptoms of swelling plus discharge in two sites (active household-based surveillance). Abscess risk was expressed as the number of abscesses per 100,000 injections and was compared for the second vs first vial dose of PCV10 and for PCV10 vs pentavalent vaccine (comparator). A total of 58,288 PCV10 injections were recorded, including 24,054 and 19,702 identified as first and second vial doses, respectively (14,532 unknown vial dose). The risk ratio for abscess following injection with the second (41 per 100,000) vs first (33 per 100,000) vial dose of PCV10 was 1.22 (95% confidence interval [CI] 0.37–4.06). The comparator vaccine was changed from a 2-dose to 10-dose presentation midway through the study. The matched odds ratios for abscess following PCV10 were 1.00 (95% CI 0.12–8.56) and 0.27 (95% CI 0.14–0.54) when compared to the 2-dose and 10-dose pentavalent vaccine presentations, respectively. In Kenya immunization with PCV10 was not associated with an increased risk of injection site abscess, providing confidence that the vaccine may be safely used in Africa. The relatively higher risk of abscess following the 10-dose presentation of pentavalent vaccine merits further study. PMID:26509274

  7. Ultrasonic Inspection Techniques Possibilities for Centrifugal Cast Copper Alloy

    Directory of Open Access Journals (Sweden)

    Konar R.

    2017-06-01

    Full Text Available The article deals with ultrasonic testing possibilities of the copper alloy centrifugal casts. It focused on the problems that arise when testing of castings is made of non-ferrous materials. Most common types of casting defects is dedicated in theoretical introduction of article. Ultrasonic testing technique by conventional ultrasound system is described in the theoretical part too. Practical ultrasonic testing of centrifugal copper alloy cast - brass is in experimental part. The experimental sample was part of centrifugally cast brass ring with dimensions of Ø1200x34 mm. The influence of microstructure on ultrasonic attenuation and limitations in testing due to attenuation is describes in experimental part. Conventional direct single element contact ultrasound probe with frequencies of 5 MHz, 3.5 MHz and 2 MHz were used for all experimental measurements. The results of experimental part of article are recommendations for selecting equipment and accessories for casting testing made of non-ferrous metals.

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

    Energy Technology Data Exchange (ETDEWEB)

    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. Liquid density effect on burst frequency in centrifugal microfluidic platforms.

    Science.gov (United States)

    Al-Faqheri, Wisam; Ibrahim, Fatimah; Thio, Tzer Hwai Gilbert; Joseph, Karunan; Mohktar, Mas S; Madou, Marc

    2015-01-01

    Centrifugal microfluidic platforms are widely used in various advanced processes such as biomedical diagnostics, chemical analysis and drug screening. This paper investigates the effect of liquid density on the burst frequency of the centrifugal microfluidic platform. This effect is experimentally investigated and compared to theoretical values. It is found that increasing the liquid density results in lower burst frequency and it is in agreement with theoretical calculations. Moreover, in this study we proposed the use of the microfluidic CD platform as an inexpensive and simple sensor for liquid density measurements. The proposed liquid sensor requires much less liquid volume (in the range of microliters) compared to conventional density meters. This study presents fundamental work which allows for future advance studies with the aim of designing and fabricating centrifugal microfluidic platforms for more complex tasks such as blood analysis.

  10. Studies on preparation of aceclofenac pellets by centrifugal granulator

    Directory of Open Access Journals (Sweden)

    Zibin GAO

    Full Text Available To prepare aceclofenac pellets by centrifugal granulation. Using 90~100 g of starch pellets as the core pellets,100 g of aceclofenac mixed with 50 g of microcrystalline cellulose(MCC and 4 g talc, methyl cellulose (HPMC as binder,the aceclofenac pellets were prepared by centrifugal granulation .And evaluate the quality of the pellets. The aceclofenac pellets had high yield and less losses,the pellets had a partical size of 0.70~0.88 mm(18~24 mesh)and had uniform particle size .the moisture ,drug content and dissolution meet the requirement . Aceclofenac pellets were prepared by the process of centrifugal granulation .The preparation prescription and process parameters were optimized by single factor method .and the pellets meet the standard requirements.

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

    Science.gov (United States)

    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.

  12. Detection of outliers in a gas centrifuge experimental data

    Directory of Open Access Journals (Sweden)

    M. C. V. Andrade

    2005-09-01

    Full Text Available Isotope separation with a gas centrifuge is a very complex process. Development and optimization of a gas centrifuge requires experimentation. These data contain experimental errors, and like other experimental data, there may be some gross errors, also known as outliers. The detection of outliers in gas centrifuge experimental data is quite complicated because there is not enough repetition for precise statistical determination and the physical equations may be applied only to control of the mass flow. Moreover, the concentrations are poorly predicted by phenomenological models. This paper presents the application of a three-layer feed-forward neural network to the detection of outliers in analysis of performed on a very extensive experiment.

  13. Fault diagnosis of monoblock centrifugal pump using SVM

    Directory of Open Access Journals (Sweden)

    V. Muralidharan

    2014-09-01

    Full Text Available Monoblock centrifugal pumps are employed in variety of critical engineering applications. Continuous monitoring of such machine component becomes essential in order to reduce the unnecessary break downs. At the outset, vibration based approaches are widely used to carry out the condition monitoring tasks. Particularly fuzzy logic, support vector machine (SVM and artificial neural networks were employed for continuous monitoring and fault diagnosis. In the present study, the application of SVM algorithm in the field of fault diagnosis and condition monitoring is discussed. The continuous wavelet transforms were calculated for different families and at different levels. The computed transformation coefficients form the feature set for the classification of good and faulty conditions of the components of centrifugal pump. The classification accuracies of different continuous wavelet families at different levels were calculated and compared to find the best wavelet for the fault diagnosis of the monoblock centrifugal pump.

  14. Passively Shunted Piezoelectric Damping of Centrifugally-Loaded Plates

    Science.gov (United States)

    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.

  15. Bicicleta, circulación vial y espacio público en la Italia fascista.

    Directory of Open Access Journals (Sweden)

    Carlos Héctor Caracciolo.

    2009-09-01

    Full Text Available While the bicycle has not changed much since the end of the nineteenth century, the world around it -fashion, customs, technology, ideology, material culture, political and economic systems- has changed. The bicycle was a part of many aspects of Italian life (work, sports, politics, leisure for various decades and its social meaning changed over the years. This article analyzes the bicycle during the fascist dictatorship: the transformation of its social meaning and its relationship with public space. It highlights the values, strategies of power, hierarchies, tensions, and contradictions of the society and the regime, proposing a way to read them that is useful for understanding other contexts and eras.

  16. Design Method for Channel Diffusers of Centrifugal Compressors

    Directory of Open Access Journals (Sweden)

    Mykola Kalinkevych

    2013-01-01

    Full Text Available The design method for channel diffusers of centrifugal compressors, which is based on the solving of the inverse problem of gas dynamics, is presented in the paper. The concept of the design is to provide high pressure recovery of the diffuser by assuming the preseparation condition of the boundary layer along one of the channel surfaces. The channel diffuser was designed with the use of developed method to replace the vaned diffuser of the centrifugal compressor model stage. The numerical simulation of the diffusers was implemented by means of CFD software. Obtained gas dynamic characteristics of the designed diffuser were compared to the base vaned diffuser of the compressor stage.

  17. Secondary Containment Design for a High Speed Centrifuge

    Energy Technology Data Exchange (ETDEWEB)

    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.

  18. Sharp nonlinear stability for centrifugal filtration convection in magnetizable media.

    Science.gov (United States)

    Saravanan, S; Brindha, D

    2011-11-01

    A nonlinear stability theory is adopted to study centrifugal thermal convection in a magnetic-fluid-saturated and differentially heated porous layer placed in a zero-gravity environment. The axis of rotation of the layer is placed within its boundaries that leads to an alternating direction of the centrifugal body force. An analysis through the variational principles is made to find the unconditional and sharp nonlinear limits. The compound matrix method is employed to solve the eigenvalue problems of the nonlinear and corresponding linear theories. The importance of nonlinear theory is established by demonstrating the failure of the linear theory in capturing the physics of the onset of convection.

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

    Science.gov (United States)

    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.

  20. Rapid determination of vial heat transfer parameters using tunable diode laser absorption spectroscopy (TDLAS) in response to step-changes in pressure set-point during freeze-drying.

    Science.gov (United States)

    Kuu, Wei Y; Nail, Steven L; Sacha, Gregory

    2009-03-01

    The purpose of this study was to perform a rapid determination of vial heat transfer parameters, that is, the contact parameter K(cs) and the separation distance l(v), using the sublimation rate profiles measured by tunable diode laser absorption spectroscopy (TDLAS). In this study, each size of vial was filled with pure water followed by a freeze-drying cycle using a LyoStar II dryer (FTS Systems) with step-changes of the chamber pressure set-point at to 25, 50, 100, 200, 300, and 400 mTorr. K(cs) was independently determined by nonlinear parameter estimation using the sublimation rates measured at the pressure set-point of 25 mTorr. After obtaining K(cs), the l(v) value for each vial size was determined by nonlinear parameter estimation using the pooled sublimation rate profiles obtained at 25 to 400 mTorr. The vial heat transfer coefficient K(v), as a function of the chamber pressure, was readily calculated, using the obtained K(cs) and l(v) values. It is interesting to note the significant difference in K(v) of two similar types of 10 mL Schott tubing vials, primary due to the geometry of the vial-bottom, as demonstrated by the images of the contact areas of the vial-bottom. (c) 2008 Wiley-Liss, Inc. and the American Pharmacists Association

  1. Effect of chronic centrifugation on body composition in the rat.

    Science.gov (United States)

    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.

  2. Study of a centrifugal pump, asynchronous motor and inverter, using ...

    African Journals Online (AJOL)

    ... concept to the study of a three-phase inverter, asynchronous motor and centrifugal pump. It presents the realization of the rectangular control using a micro controller (ATMEGA 168). The signals generated by the micro controller have been used to program the parallel port of a computer. By reading the recorded bits of the ...

  3. The effect of balance holes to centrifugal pump performance

    Science.gov (United States)

    Babayigit, O.; Ozgoren, M.; Aksoy, M. H.; Kocaaslan, O.

    2017-07-01

    The aim of this study is to analyze of a centrifugal pump with and without balance holes by using ANSYS-Fluent software. The pump used in the study is a commercial centrifugal pump consisting of two stages that is a model of Sempa Pump Company. Firstly, models of impeller, diffuser, suction and discharge sections of the centrifugal pump were separately drawn using Ansys and Solidworks software. Later, grid structures were generated on the flow volume of the pump. Turbulent flow volume was numerically solved by realizable k-є turbulence model. The flow analyses were focused on the centrifugal pump performance and the flow characteristics under different operational conditions with/without balance holes. Distributions of flow characteristics such as velocity and pressure distributions in the flow volume were also determined, numerically. The results of Computational Fluid Dynamics (CFD) with/without balance holes for the pump head and hydraulic efficiency on the design flow rate of 80 m3/h were found to be 81.5/91.3 m and 51.9/65.3%, respectively.

  4. NUMERICAL SIMULATION OF MASS TRANSFER IN CENTRIFUGAL EVAPORATOR

    Directory of Open Access Journals (Sweden)

    E. N. Kalinin

    2017-01-01

    Full Text Available Subject of Research. The paper deals with the problem of an adequate mathematical model of mass transfer process occurring during evaporation and concentration of spent process solution in a centrifugal evaporator with variable geometric parameters. The model provides a science-based forecast of the process parameters. Methods. Definition of the film flow parameters on a rotating conical surface of the centrifugal evaporator rotor is carried out on the basis of the solution of Navier-Stokes equations. Solution of the system of differential equations describing the mass transfer process in the studied dynamic system is performed by numerical methods. With this aim in view, we realized semi-implicit finite difference scheme for the SIMPLE pressure. Main Results. We have developed an algorithm and performed numerical solution of differential equations describing the mass transfer process occurring during concentration of the working solution in the centrifugal type evaporator. On the basis of the obtained numerical solution we have created a computer model of the given process. With the aid of the model we have defined basic hydrodynamic and operating parameters of the evaporator, as well as dependencies between them. Practical Relevance. Developed computer model of the mass transfer process enables to define the parameters of the solution moving along the conical surface of the centrifugal evaporator rotor: speed, pressure and the thickness of the flowing-down film. The results can be applied in real industrial process management and during personnel training.

  5. Fast Pyrolysis of Lignin Using a Pyrolysis Centrifuge Reactor

    DEFF Research Database (Denmark)

    Trinh, Ngoc Trung; Jensen, Peter Arendt; Sárossy, Zsuzsa

    2013-01-01

    Fast pyrolysis of lignin from an ethanol plant was investigated on a lab scale pyrolysis centrifuge reactor (PCR) with respect to pyrolysis temperature, reactor gas residence time, and feed rate. A maximal organic oil yield of 34 wt % dry basis (db) (bio-oil yield of 43 wt % db) is obtained...

  6. Design Optimization of Centrifugal Pump Using Radial Basis Function Metamodels

    Directory of Open Access Journals (Sweden)

    Yu Zhang

    2014-05-01

    Full Text Available Optimization design of centrifugal pump is a typical multiobjective optimization (MOO problem. This paper presents an MOO design of centrifugal pump with five decision variables and three objective functions, and a set of centrifugal pumps with various impeller shroud shapes are studied by CFD numerical simulations. The important performance indexes for centrifugal pump such as head, efficiency, and required net positive suction head (NPSHr are investigated, and the results indicate that the geometry shape of impeller shroud has strong effect on the pump's performance indexes. Based on these, radial basis function (RBF metamodels are constructed to approximate the functional relationship between the shape parameters of impeller shroud and the performance indexes of pump. To achieve the objectives of maximizing head and efficiency and minimizing NPSHr simultaneously, multiobjective evolutionary algorithm based on decomposition (MOEA/D is applied to solve the triobjective optimization problem, and a final design point is selected from the Pareto solution set by means of robust design. Compared with the values of prototype test and CFD simulation, the solution of the final design point exhibits a good consistency.

  7. Synthesis and Analytical Centrifugation of Magnetic Model Colloids

    NARCIS (Netherlands)

    Luigjes, B.|info:eu-repo/dai/nl/31412330X

    2012-01-01

    This thesis is a study of the preparation and thermodynamic properties of magnetic colloids. First, two types of magnetic model colloids are investigated: composite colloids and single-domain nanoparticles. Thermodynamics of magnetic colloids is studied using analytical centrifugation, including a

  8. Latex micro-balloon pumping in centrifugal microfluidic platforms.

    Science.gov (United States)

    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.

  9. Advanced Remote Maintenance Design for Pilot-Scale Centrifugal Contactors

    Energy Technology Data Exchange (ETDEWEB)

    Jack Law; David Meikrantz; Troy Garn; Lawrence Macaluso

    2011-02-01

    Advanced designs of used nuclear fuel recycling processes and radioactive waste treatment processes are expected to include more ambitious goals for aqueous based separations including; higher separations efficiency, high-level waste minimization, and a greater focus on continuous processes to minimize cost and footprint. Therefore, annular centrifugal contactors are destined to play a more important role for such future processing schemes. Pilot-scale testing will be an integral part of development of many of these processes. An advanced design for remote maintenance of pilot-scale centrifugal contactors has been developed and a prototype module fabricated and tested for a commercially available pilot-scale centrifugal contactor (CINC V-02, 5-cm rotor diameter). Advanced design features include air actuated clamps for holding the motor-rotor assembly in place, an integral electrical connection, upper flange o-rings, a welded bottom plate, a lifting bale, and guide pins. These design features will allow for rapid replacement of the motor rotor assembly, which can be accomplished while maintaining process equilibrium. Hydraulic testing of a three-stage prototype unit was also performed to verify that design changes did not impact performance of the centrifugal contactors. Details of the pilot-scale remote maintenance design, results of testing in a remote mockup test facility, and results of hydraulic testing of the advanced design are provided.

  10. Centrifuge modeling of LNAPL transport in partially saturated sand

    NARCIS (Netherlands)

    Esposito, G.; Allersma, H.G.B.; Selvadurai, A.P.S.

    1999-01-01

    Model tests were performed at the Geotechnical Centrifuge Facility of Delft University of Technology, The Netherlands, to examine the mechanics of light nonaqueous phase liquid (LNAPL) movement in a partially saturated porous granular medium. The experiment simulated a 2D spill of LNAPL in an

  11. Centrifugally driven microfluidic disc for detection of chromosomal translocations

    DEFF Research Database (Denmark)

    Brøgger, Anna Line; Kwasny, Dorota; Bosco, Filippo G.

    2012-01-01

    and prognosis of patients. In this work we demonstrate a novel, centrifugally-driven microfluidic system for controlled manipulation of oligonucleotides and subsequent detection of chromosomal translocations. The device is fabricated in the form of a disc with capillary burst microvalves employed to control...

  12. Page 1 Centrifugal distortion constants - - 115 triangular form ...

    Indian Academy of Sciences (India)

    Centrifugal distortion constants - - 115 triangular form (Ananthakrishnan et al 1972, 1973, 1976). In this context, setting. C equal to unit matrix is identical with the L matrix approximation technique developed by Muller (Alix et al 1975) and should hold good for nonhydride mole- cules as is implied in the observations of Strey ...

  13. Numerical analysis on centrifugal compressor with membrane type dryer

    Science.gov (United States)

    Razali, M. A.; Zulkafli, M. F.; Mat Isa, N.; Subari, Z.

    2017-09-01

    Moisture content is a common phenomenon in industrial processes especially in oil and gas industries. This contaminant has a lot of disadvantages which can lead to mechanical failure DEC (Deposition, Erosion & Corrosion) problems. To overcome DEC problem, this study proposed to design a centrifugal compressor with a membrane type dryer to reduce moisture content of a gas. The effectiveness of such design has been analyzed in this study using Computational Fluid Dynamics (CFD) approach. Numerical scheme based on multiphase flow technique is used in ANSYS Fluent software to evaluate the moisture content of the gas. Through this technique, two kind of centrifugal compressor, with and without membrane type dryer has been tested. The results show that the effects of pressure on dew point temperature of the gas change the composition of its moisture content, where high value lead more condensation to occur. However, with the injection of cool dry gas through membrane type dryer in the centrifugal compressor, the pressure and temperature of moisture content as well as mass fraction of H2O in centrifugal compressor show significant reduction.

  14. Model Based Fault Detection in a Centrifugal Pump Application

    DEFF Research Database (Denmark)

    Kallesøe, Carsten; Cocquempot, Vincent; Izadi-Zamanabadi, Roozbeh

    2006-01-01

    A model based approach for fault detection in a centrifugal pump, driven by an induction motor, is proposed in this paper. The fault detection algorithm is derived using a combination of structural analysis, observer design and Analytical Redundancy Relation (ARR) design. Structural considerations...... is capable of detecting four different faults in the mechanical and hydraulic parts of the pump....

  15. Centrifuge modelling of a laterally cyclic loaded pile

    DEFF Research Database (Denmark)

    Klinkvort, Rasmus Tofte; Leth, Caspar Thrane; Hededal, Ole

    2010-01-01

    A total number of 9 static and 6 cyclic centrifuge tests on laterally loaded piles in very dense, dry sand was erformed. The prototype dimensions of the piles were 1 meter in diameter and penetration depths varying from 6 to 10 meters. The static tests were used to investigate the initial subgrade...

  16. Novel method for continuous cell separation by density gradient centrifugation: evaluation of a miniature separation column.

    Science.gov (United States)

    Shiono, Hiroyuki; Ito, Yoichiro

    2003-05-01

    A compact bench-top model of the centrifuge enables continuous cell separation based on density differences. The apparatus holds a small separation disk equipped with a circular channel (8 mL capacity) separated by a septum. A set of isotonic Percoll media with different densities is continuously introduced at one terminal and collected from the other. Under a centrifugal force field, cell suspension introduced into the proximal portion of the channel results in continuous separation of cells according to their densities. The performance of the apparatus was demonstrated with the separation of human buffy coat containing nucleated cells (>10(8)) among a large population (10(10)) of RBC. The results indicated that the method is capable of separating a large number of nucleated cells, with minimum damage, for a few hours of operation wherein neutrophils are well resolved from lymphocytes. The method may be applied to other types of samples including cord blood, blood from small animals, cultured cells, pancreatic beta cell islets, malaria parasites, sperm cells, etc.

  17. Dysrhythmias in Laypersons During Centrifuge-Simulated Suborbital Spaceflight.

    Science.gov (United States)

    Suresh, Rahul; Blue, Rebecca S; Mathers, Charles H; Castleberry, Tarah L; Vanderploeg, James M

    2017-11-01

    There are limited data on cardiac dysrhythmias in laypersons during hypergravity exposure. We report layperson electrocardiograph (ECG) findings and tolerance of dysrhythmias during centrifuge-simulated suborbital spaceflight. Volunteers participated in varied-length centrifuge training programs of 2-7 centrifuge runs over 0.5-2 d, culminating in two simulated suborbital spaceflights of combined +Gz and +Gx (peak +4.0 Gz, +6.0 Gx, duration 5 s). Monitors recorded pre- and post-run mean arterial blood pressure (MAP), 6-s average heart rate (HR) collected at prespecified points during exposures, documented dysrhythmias observed on continuous 3-lead ECG, self-reported symptoms, and objective signs of intolerance on real-time video monitoring. Participating in the study were 148 subjects (43 women). Documented dysrhythmias included sinus pause (N = 5), couplet premature ventricular contractions (N = 4), bigeminy (N = 3), accelerated idioventricular rhythm (N = 1), and relative bradycardia (RB, defined as a transient HR drop of >20 bpm; N = 63). None were associated with subjective symptoms or objective signs of acceleration intolerance. Episodes of RB occurred only during +Gx exposures. Subjects had a higher post-run vs. pre-run MAP after all exposures, but demonstrated no difference in pre- and post-run HR. RB was more common in men, younger individuals, and subjects experiencing more centrifuge runs. Dysrhythmias in laypersons undergoing simulated suborbital spaceflight were well tolerated, though RB was frequently noted during short-duration +Gx exposure. No subjects demonstrated associated symptoms or objective hemodynamic sequelae from these events. Even so, heightened caution remains warranted when monitoring dysrhythmias in laypersons with significant cardiopulmonary disease or taking medications that modulate cardiac conduction.Suresh R, Blue RS, Mathers CH, Castleberry TL, Vanderploeg JM. Dysrhythmias in laypersons during centrifuge-stimulated suborbital

  18. La valoración monetaria de los costes humanos de la siniestralidad vial en España

    Directory of Open Access Journals (Sweden)

    Jorge Eduardo Martínez Pérez

    2015-09-01

    Full Text Available Los análisis coste-beneficio en el ámbito de la seguridad vial han de computar la totalidad de los costes, y dentro de ellos ocupan un lugar clave los costes humanos. En esta nota se da cuenta de dos estudios promovidos por la Dirección General de Tráfico orientados a la obtención de valores oficiales para España de los costes asociados a las víctimas mortales y no mortales de los accidentes de tráfico. Mediante la combinación del enfoque de la valoración contingente con la técnica de la lotería estándar (modificada, y con muestras amplias (n1 = 2020, n2 = 2000 representativas de la población española, se estimó en 1,4 millones de euros el valor monetario de prevenir un fallecido por accidente de tráfico. Para las lesiones graves y leves, los valores estimados fueron de 219.000 y 6100 euros, respectivamente. Las cifras obtenidas tienen un orden de magnitud similar al de los países de nuestro entorno.

  19. Single vial kit formulation of DOTATATE for preparation of (177) Lu-labeled therapeutic radiopharmaceutical at hospital radiopharmacy.

    Science.gov (United States)

    Mukherjee, Archana; Lohar, Sharad; Dash, Ashutosh; Sarma, Haladhar Dev; Samuel, Grace; Korde, Aruna

    2015-04-01

    The clinical applications of radiolabeled somatostatin analogue (177) Lu-DOTA-Tyr(3) -Thr(8) -Octreotide ((177) Lu-DOTATATE) constitute a promising treatment option for patients with disseminated and inoperable neuroendocrine (NET) tumors. Formulation of (177) Lu-DOTATATE in hospital radiopharmacy under aseptic conditions in a safe and reliable manner is a major constraint for its extensive use. The present work was intended to develop a kit for the safe preparation of the therapeutic radiopharmaceutical, viz. (177) Lu-DOTATATE of high quality that can be easily adapted at conventional hospital radiopharmacies. Single vial kits of DOTATATE were formulated and evaluated for suitability for radiolabeling as well as stability on its storage. Patient dose of (177) Lu-DOTATATE (7.4 GBq) could be successfully prepared using semi-automated in-house setup that assures safe handling and high yields of product of pharmaceutical purity suitable for clinical use. Fast clearance of activity via renal route was observed in preclinical biodistribution studies of (177) Lu-DOTATATE carried out in normal Swiss mice. Deployment of in-house produced (177) LuCl3 , cold kits and easy adaptability of synthesis setup at hospital radiopharmacy for preparation is likely to expand applications of peptide receptor radionuclide therapy. Copyright © 2015 John Wiley & Sons, Ltd.

  20. A novel technique using the Hendrickx centrifuge for extracting winter sporangia of Synchytrium endobioticum from soil

    NARCIS (Netherlands)

    Wander, J.G.N.; Berg, van den W.; Boogert, van den P.H.J.F.; Lamers, J.G.; Leeuwen, van G.C.M.; Hendrickx, G.; Bonants, P.J.M.

    2007-01-01

    A zonal centrifugation method, known as the Hendrickx centrifuge technique, was tested for routine detection of winter sporangia of Synchytrium endobioticum in soil. In four experiments the ability of the Hendrickx centrifuge to extract the sporangia from soil was compared with a method used by the

  1. Medical incidences during centrifuge training and F-16 flying in the Netherlands

    NARCIS (Netherlands)

    Holewijn, M.

    1996-01-01

    A survey in the NAMC database containing the records of centrifuge runs of candidate and experienced pilots revealed that in 15.1% of the centrifuge training sessions, a run was stopped. The major reasons were motion sickness (31%), fatigue (28%), and arrhythmias (22%). During centrifuge training at

  2. Design and construction of a two-stage centrifugal pump | Nordiana ...

    African Journals Online (AJOL)

    Centrifugal pumps are widely used in moving liquids from one location to another in homes, offices and industries. Due to the ever increasing demand for centrifugal pumps it became necessary to design and construction of a two-stage centrifugal pump. The pump consisted of an electric motor, a shaft, two rotating impellers ...

  3. Calibration-free sensor for pressure and H2O concentration in headspace of sterile vial using tunable diode laser absorption spectroscopy.

    Science.gov (United States)

    Cai, Tingdong; Gao, Guangzhen; Liu, Ying

    2013-11-10

    Tunable diode laser absorption measurements of pressure and H2O concentration in the headspace of vials using a distributed-feedback (DFB) diode laser near 1.4 μm are reported. A H2O line located near 7161.41 cm(-1) is selected based on its strong absorption strength and isolation from interference of neighboring transitions. Direct absorption spectra of H2O are obtained for the measurement path as well as the reference path by scanning the laser wavelength. The pressure and H2O vapor concentration in the headspace of a vial are inferred from a differential absorption signal, which is the difference between the measured and the referenced absorbance spectra. This sensor is calibration-free and no purge gas is needed. The demonstrated capability would enable measurements of pressure and H2O concentration in the headspace of vials within 2.21% and 2.86%, respectively. A precision of 1.02 Torr and 390 ppm is found for the pressure and H2O concentration, respectively. A set of measurements for commercial freeze-dried products are also performed to illustrate the usefulness of this sensor.

  4. Through-vial impedance spectroscopy of critical events during the freezing stage of the lyophilization cycle: the example of the impact of sucrose on the crystallization of mannitol.

    Science.gov (United States)

    Arshad, Muhammad Sohail; Smith, Geoff; Polygalov, Eugene; Ermolina, Irina

    2014-08-01

    The aim of this work was to evaluate the application of through-vial impedance spectroscopy in the measurement of eutectic crystallization during the freezing stage of the lyophilisation cycle. Impedance measurements of various sugar solutions (mannitol 5%, 10% and 15% w/v, sucrose 5% w/v and mannitol 5% w/v, and sucrose 5% w/v solutions) were taken during a freeze-thaw cycle, over a frequency range 10-10(6) Hz with a scan interval of 1.5 min, using measurement vials with externally attached electrodes connected to a high resolution impedance analyzer. Estimates for the electrical resistance of the mannitol solutions record the exothermic crystallization of mannitol at a temperature of -24 °C during the temperature ramp down stage of the freezing cycle, which is in close agreement with the off-line DSC measurement of -22 °C. The freezing profile of a 5% mannitol solution with 5% sucrose (a component that does not crystallize in the frozen solution) demonstrated the inhibition of mannitol crystallization (with the implication that the product will then require sub-Tg' freezing and drying). The work suggests a role for through-vial impedance spectroscopy in the concurrent development of the product formulation and freeze drying cycle without the uncertainty introduced when using off-line date to define the critical process parameters. Copyright © 2014 Elsevier B.V. All rights reserved.

  5. Evaluación del pavimento de la carretera “cumbe – oña (tramo i)” de 20 km de longitud, ubicada en la provincia del Azuay mediante equipos de auscultación vial

    OpenAIRE

    Bravo Castro, María Fernanda

    2011-01-01

    Evaluacion del Pavimento de la Carretera “Cumbe – Oña (Tramo I)” de 20 Km de longitud, ubicada en la Provincia del Azuay mediante Equipos de Auscultación Vial Evaluacion del Pavimento de la Carretera “Cumbe – Oña (Tramo I)” de 20 Km de longitud, ubicada en la Provincia del Azuay mediante Equipos de Auscultación Vial

  6. Optimization of centrifugal pump cavitation performance based on CFD

    Science.gov (United States)

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

    2015-01-01

    In order to further improve the cavitation performance of a centrifugal pump, slots on impeller blade near inlet were studied and six groups of hydraulic model were designed. Base on cavitating flow feature inside a centrifugal pump, bubble growth and implosion are calculated from the Rayleigh-Plesset equation which describes the dynamic behavior of spherical bubble and RNG κ-epsilon model was employed to simulate and analyze the internal two-phase flow of the model pump under the same conditions. The simulation results show that slots on blade near inlet could improve the cavitation performance and cavitation performance improvement of the second group was more obvious. Under the same conditions, the pressure on the back of blade near inlet was higher than the pressure on the back of unmodified blade near inlet, and energy distribution in the flow channel between the two blades was more uniform with a small change of head.

  7. Massively parallel single-molecule manipulation using centrifugal force

    CERN Document Server

    Halvorsen, Ken

    2009-01-01

    Precise manipulation of single molecules has already led to remarkable insights in physics, chemistry, biology and medicine. However, widespread adoption of single-molecule techniques has been impeded by equipment cost and the laborious nature of making measurements one molecule at a time. We have solved these issues with a new approach: massively parallel single-molecule force measurements using centrifugal force. This approach is realized in a novel instrument that we call the Centrifuge Force Microscope (CFM), in which objects in an orbiting sample are subjected to a calibration-free, macroscopically uniform force-field while their micro-to-nanoscopic motions are observed. We demonstrate high-throughput single-molecule force spectroscopy with this technique by performing thousands of rupture experiments in parallel, characterizing force-dependent unbinding kinetics of an antibody-antigen pair in minutes rather than days. Additionally, we verify the force accuracy of the instrument by measuring the well-est...

  8. Analysis of cantilever NEMS in centrifugal-fluidic systems

    Science.gov (United States)

    Mohsen-Nia, Mohsen; Abadian, Fateme; Abadian, Naeime; Dehkordi, Keivan Mosaiebi; Keivani, Maryam; Abadyan, Mohamadreza

    2016-07-01

    Electromechanical nanocantilevers are promising for using as sensors/detectors in centrifugal-fluidic systems. For this application, the presence of angular speed and electrolyte environment should be considered in the theoretical analysis. Herein, the pull-in instability of the nanocantilever incorporating the effects of angular velocity and liquid media is investigated using a size-dependent continuum theory. Using d’Alembert principle, the angular speed is transformed into an equivalent centrifugal force. The electrochemical and dispersion forces are incorporated considering the corrections due to the presence of electrolyte media. Two different approaches, i.e., the Rayleigh-Ritz method (RRM) and proposing a lumped parameter model (LPM), were applied to analyze the system. The models are validated with the results presented in literature. Impacts of the angular velocity, electrolyte media, dispersion forces, and size effect on the instability characteristics of the nanocantilever are discussed.

  9. Effect of piping systems on surge in centrifugal compressors

    Energy Technology Data Exchange (ETDEWEB)

    Tamaki, Hideaki [Products Development Center, Yokohama (Japan)

    2008-10-15

    There is a possibility that the exchange of the piping system may change the surge characteristic of a compressor. The piping system of a plant is not always the same as that of a test site. Then it is important to evaluate the effect of piping systems on surge characteristics in centrifugal compressors. Several turbochargers combined with different piping systems were tested. The lumped parameter model which was simplified to be solved easily was applied for the prediction of surge point. Surge lines were calculated with the linearlized lumped parameter model. The difference between the test and calculated results was within 10 %. Trajectory of surge cycle was also examined by solving the lumped parameter model. Mild surge and deep surge were successfully predicted. This study confirmed that the lumped parameter model was a very useful tool to predict the effect of piping systems on surge characteristics in centrifugal compressors, even though that was a simple model

  10. Centrifuge modelling of drained lateral pile - soil response

    DEFF Research Database (Denmark)

    Klinkvort, Rasmus Tofte

    popular foundation methods today for offshore wind turbines. These piles are often installed in dense sand at water depths ranging from 10-30 meters. A monopile is a single, large diameter tubular steel pile. The current design methodology originates from tests on long slender piles but is also used...... for monopiles today. Therefore it appears that the methodology for monopiles lacks scientific justification and a better understanding of rigid piles is needed. More than 70 centrifuge tests on laterally loaded rigid model piles have been carried out in connection with this thesis to get a better understanding...... of rigid piles. The tests have been performed in homogeneously dense dry or saturated Fontainebleau sand in order to mimic simplified drained offshore soil conditions. Approximately half of the tests have been carried out to investigate the centrifuge procedure in order to create a methodology of testing...

  11. Effect of room temperature transport vials on DNA quality and phylogenetic composition of faecal microbiota of elderly adults and infants.

    Science.gov (United States)

    Hill, Cian J; Brown, Jillian R M; Lynch, Denise B; Jeffery, Ian B; Ryan, C Anthony; Ross, R Paul; Stanton, Catherine; O'Toole, Paul W

    2016-05-10

    Alterations in intestinal microbiota have been correlated with a growing number of diseases. Investigating the faecal microbiota is widely used as a non-invasive and ethically simple proxy for intestinal biopsies. There is an urgent need for collection and transport media that would allow faecal sampling at distance from the processing laboratory, obviating the need for same-day DNA extraction recommended by previous studies of freezing and processing methods for stool. We compared the faecal bacterial DNA quality and apparent phylogenetic composition derived using a commercial kit for stool storage and transport (DNA Genotek OMNIgene GUT) with that of freshly extracted samples, 22 from infants and 20 from older adults. Use of the storage vials increased the quality of extracted bacterial DNA by reduction of DNA shearing. When infant and elderly datasets were examined separately, no differences in microbiota composition were observed due to storage. When the two datasets were combined, there was a difference according to a Wilcoxon test in the relative proportions of Faecalibacterium, Sporobacter, Clostridium XVIII, and Clostridium XlVa after 1 week's storage compared to immediately extracted samples. After 2 weeks' storage, Bacteroides abundance was also significantly different, showing an apparent increase from week 1 to week 2. The microbiota composition of infant samples was more affected than that of elderly samples by storage, with significantly higher Spearman distances between paired freshly extracted and stored samples (p microbiota profiles were analysed at the operational taxonomic unit (OTU) level, three infant datasets in the study did not cluster together, while only one elderly dataset did not. The lower microbiota diversity of the infant gut microbiota compared to the elderly gut microbiota (p microbiota samples, but may be less appropriate for lower diversity samples. Differences between fresh and stored samples mean that where storage is

  12. Scalp psoriasis associated with central centrifugal cicatricial alopecia

    Directory of Open Access Journals (Sweden)

    Krista N. Larson

    2017-01-01

    Full Text Available Scalp psoriasis is a very common dermatological condition with a variety of presentations, but only rarely presents as severe alopecia. We present a case of a 50-year-old female with many years of recalcitrant hair loss that was thought to be secondary to central centrifugal cicatricial alopecia which was later diagnosed as psoriasis. This case highlights an interesting presentation and rare complication of a common disease.

  13. Centrifugal stretching of 170Hf in the interacting boson model

    Directory of Open Access Journals (Sweden)

    Werner V.

    2014-03-01

    Full Text Available We present the results of a recent experiment to deduce lifetimes of members of the ground state rotational band of 170Hf, which show the effect of centrifugal stretching in this deformed isotope. Results are compared to the geometrical confined beta-soft(CBS rotor model, as well as to the interacting boson model (IBM. Two methods to correct for effects due to the finite valence space within the IBM are proposed.

  14. Laser tracker TSPI uncertainty quantification via centrifuge trajectory

    Science.gov (United States)

    Romero, Edward; Paez, Thomas; Brown, Timothy; Miller, Timothy

    2009-08-01

    Sandia National Laboratories currently utilizes two laser tracking systems to provide time-space-position-information (TSPI) and high speed digital imaging of test units under flight. These laser trackers have been in operation for decades under the premise of theoretical accuracies based on system design and operator estimates. Advances in optical imaging and atmospheric tracking technology have enabled opportunities to provide more precise six degree of freedom measurements from these trackers. Applying these technologies to the laser trackers requires quantified understanding of their current errors and uncertainty. It was well understood that an assortment of variables contributed to laser tracker uncertainty but the magnitude of these contributions was not quantified and documented. A series of experiments was performed at Sandia National Laboratories large centrifuge complex to quantify TSPI uncertainties of Sandia National Laboratories laser tracker III. The centrifuge was used to provide repeatable and economical test unit trajectories of a test-unit to use for TSPI comparison and uncertainty analysis. On a centrifuge, testunits undergo a known trajectory continuously with a known angular velocity. Each revolution may represent an independent test, which may be repeated many times over for magnitudes of data practical for statistical analysis. Previously these tests were performed at Sandia's rocket sled track facility but were found to be costly with challenges in the measurement ground truth TSPI. The centrifuge along with on-board measurement equipment was used to provide known ground truth position of test units. This paper discusses the experimental design and techniques used to arrive at measures of laser tracker error and uncertainty.

  15. An alternative arrangement of metered dosing fluid using centrifugal pump

    Science.gov (United States)

    Islam, Md. Arafat; Ehsan, Md.

    2017-06-01

    Positive displacement dosing pumps are extensively used in various types of process industries. They are widely used for metering small flow rates of a dosing fluid into a main flow. High head and low controllable flow rates make these pumps suitable for industrial flow metering applications. However their pulsating flow is not very suitable for proper mixing of fluids and they are relatively more expensive to buy and maintain. Considering such problems, alternative techniques to control the fluid flow from a low cost centrifugal pump is practiced. These include - throttling, variable speed drive, impeller geometry control and bypass control. Variable speed drive and impeller geometry control are comparatively costly and the flow control by throttling is not an energy efficient process. In this study an arrangement of metered dosing flow was developed using a typical low cost centrifugal pump using bypass flow technique. Using bypass flow control technique a wide range of metered dosing flows under a range of heads were attained using fixed pump geometry and drive speed. The bulk flow returning from the system into the main tank ensures better mixing which may eliminate the need of separate agitators. Comparative performance study was made between the bypass flow control arrangement of centrifugal pump and a diaphragm type dosing pump. Similar heads and flow rates were attainable using the bypass control system compared to the diaphragm dosing pump, but using relatively more energy. Geometrical optimization of the centrifugal pump impeller was further carried out to make the bypass flow arrangement more energy efficient. Although both the systems run at low overall efficiencies but the capital cost could be reduced by about 87% compared to the dosing pump. The savings in capital investment and lower maintenance cost very significantly exceeds the relatively higher energy cost of the bypass system. This technique can be used as a cost effective solution for

  16. A Large Radius Human Centrifuge: The Human Hypergravity Havitat

    Science.gov (United States)

    van Loon, J. J. W. A.

    2008-06-01

    Life on Earth has developed at unit gravity, 9.81 m/s2, but how would plants and animals have evolved on a larger planet, i.e. larger than Earth? We are able to address this question simply by studies using centrifuges. In the past decades numerous experiments have been performed on cells, plants and animals grown for longer durations, even multi generations, under hypergravity conditions. Based on these studies we have gained interesting insights in the physiological process of these systems when exposed to artificial gravity. Animals and plants adapt themselves to this new high-g environment. Information of adaptation to hyper-g in mammals is interesting, or maybe even proof vital, for future human space flight programs especially in light of long duration missions to Moon and Mars. We know from long duration animal studies that numerous physiological processes and structures like muscles, bones, neuro-vestibular, or the cardiovascular system are affected. However, humans have never been exposed to a hyper-g environment for long durations. Human studies are mostly in the order of hours at most. Current work on human centrifuges is all focused on short arm systems to apply artificial gravity in long duration space missions. In this paper we want to address the possible usefulness of a large radius human centrifuge on Earth, or even on Moon or Mars, for both basic research and possible applications. In such a centrifuge a group of humans may be exposed to hypergravity for, in principle, an unlimited period of time.

  17. A new practice in fruit trees: Centrifugal training system

    Directory of Open Access Journals (Sweden)

    Ersin ATAY

    2013-06-01

    Full Text Available The choice of the training system is a rather important decision for yield, fruit quality and profitability. There were dramatic changes in concepts for apple training in the last years. Centrifugal training system which was one of the innovations was developed in the beginning of the 2000’s in France. SolAxe training system forms the main part of this training system. The most innovative aspect of the Centrifugal training system is the artificial extinction technique. This technique is carried out more specifically in the center of the tree and on the underside of branches to remove potentially poor quality fruits. Artificial extinction improves light distribution within the tree canopy especially in colored-fruit varieties for which the light climate is particularly important. It also offers an alternative training method to reduce biennial bearing. In addition to canopy porosity created by artificial extinction, this training system can help reducing disease and harmful insects. In this study it is aimed to explain general rules of centrifugal training system.

  18. Prenatal centrifugation: A model for fetal programming of adult weight?

    Science.gov (United States)

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

    2005-08-01

    'Fetal programming' is a newly emerging field that is revealing astounding insights into the prenatal origins of adult disease, including metabolic, endocrine, and cardiovascular pathophysiology. In the present study, we tested the hypothesis that rat pups conceived, gestated and born at 2-g have significantly reduced birth weights and increased adult body weights as compared to 1-g controls. Offspring were produced by mating young adult male and female rats that were adapted to 2-g centrifugation. Female rats underwent conception, pregnancy and birth at 2-g. Newborn pups in the 2-g condition were removed from the centrifuge and fostered to non-manipulated, newly parturient dams maintained at 1-g. Comparisons were made with 1-g stationary controls, also cross- fostered at birth. As compared to 1-g controls, birth weights of pups gestated and born at 2-g were significantly reduced. Pup body weights were significantly reduced until Postnatal day (P)12. Beginning on P63, body weights of 2-g-gestated offspring exceeded those of 1-g controls by 7-10%. Thus, prenatal rearing at 2-g restricts neonatal growth and increases adult body weight. Collectively, these data support the hypothesis that 2-g centrifugation alters the intrauterine milieu, thereby inducing persistent changes in adult phenotype.

  19. Evolutionary Optimization of Centrifugal Nozzles for Organic Vapours

    Science.gov (United States)

    Persico, Giacomo

    2017-03-01

    This paper discusses the shape-optimization of non-conventional centrifugal turbine nozzles for Organic Rankine Cycle applications. The optimal aerodynamic design is supported by the use of a non-intrusive, gradient-free technique specifically developed for shape optimization of turbomachinery profiles. The method is constructed as a combination of a geometrical parametrization technique based on B-Splines, a high-fidelity and experimentally validated Computational Fluid Dynamic solver, and a surrogate-based evolutionary algorithm. The non-ideal gas behaviour featuring the flow of organic fluids in the cascades of interest is introduced via a look-up-table approach, which is rigorously applied throughout the whole optimization process. Two transonic centrifugal nozzles are considered, featuring very different loading and radial extension. The use of a systematic and automatic design method to such a non-conventional configuration highlights the character of centrifugal cascades; the blades require a specific and non-trivial definition of the shape, especially in the rear part, to avoid the onset of shock waves. It is shown that the optimization acts in similar way for the two cascades, identifying an optimal curvature of the blade that both provides a relevant increase of cascade performance and a reduction of downstream gradients.

  20. Water Drainage from Unsaturated Soils in a Centrifuge Permeameter

    Science.gov (United States)

    Ornelas, G.; McCartney, J.; Zhang, M.

    2013-12-01

    This study involves an analysis of water drainage from an initially saturated silt layer in a centrifuge permeameter to evaluate the hydraulic properties of the soil layer in unsaturated conditions up to the point where the water phase becomes discontinuous. These properties include the soil water retention curve (SWRC) and the hydraulic conductivity function (HCF). The hydraulic properties of unsaturated silt are used in soil-atmosphere interaction models that take into account the role of infiltration and evaporation of water from soils due to atmospheric interaction. These models are often applied in slope stability analyses, landfill cover design, aquifer recharge analyses, and agricultural engineering. The hydraulic properties are also relevant to recent research concerning geothermal heating and cooling, as they can be used to assess the insulating effects of soil around underground heat exchangers. This study employs a high-speed geotechnical centrifuge to increase the self-weight of a compacted silt specimen atop a filter plate. Under a centrifuge acceleration of N times earth's gravity, the concept of geometric similitude indicates that the water flow process in a small-scale soil layer will be similar to those in a soil layer in the field that is N times thicker. The centrifuge acceleration also results in an increase in the hydraulic gradient across the silt specimen, which causes water to flow out of the pores following Darcy's law. The drainage test was performed until the rate of liquid water flow out of the soil layer slowed to a negligible level, which corresponds to the transition point at which further water flow can only occur due to water vapor diffusion following Fick's law. The data from the drainage test in the centrifuge were used to determine the SWRC and HCF at different depths in the silt specimen, which compared well with similar properties defined using other laboratory tests. The transition point at which liquid water flow stopped (and

  1. An integrated system for synchronous culture of animal cells under controlled conditions

    National Research Council Canada - National Science Library

    Mendoza-Pérez, Elena; Hernández, Vanessa; Palomares, Laura A; Serrato, José A

    2016-01-01

    .... Moreover, only a few viable cells are recovered. Here, we designed an integrated system where a large number of cells from a controlled bioreactor culture is separated by centrifugal elutriation at high viabilities...

  2. Extraction of soil solution by drainage centrifugation-effects of centrifugal force and time of centrifugation on soil moisture recovery and solute concentration in soil moisture of loess subsoils.

    Science.gov (United States)

    Fraters, Dico; Boom, Gerard J F L; Boumans, Leo J M; de Weerd, Henk; Wolters, Monique

    2017-02-01

    The solute concentration in the subsoil beneath the root zone is an important parameter for leaching assessment. Drainage centrifugation is considered a simple and straightforward method of determining soil solution chemistry. Although several studies have been carried out to determine whether this method is robust, hardly any results are available for loess subsoils. To study the effect of centrifugation conditions on soil moisture recovery and solute concentration, we sampled the subsoil (1.5-3.0 m depth) at commercial farms in the loess region of the Netherlands. The effect of time (20, 35, 60, 120 and 240 min) on recovery was studied at two levels of the relative centrifugal force (733 and 6597g). The effect of force on recovery was studied by centrifugation for 35 min at 117, 264, 733, 2932, 6597 and 14,191g. All soil moisture samples were chemically analysed. This study shows that drainage centrifugation offers a robust, reproducible and standardised way for determining solute concentrations in mobile soil moisture in silt loam subsoils. The centrifugal force, rather than centrifugation time, has a major effect on recovery. The maximum recovery for silt loams at field capacity is about 40%. Concentrations of most solutes are fairly constant with an increasing recovery, as most solutes, including nitrate, did not show a change in concentration with an increasing recovery.

  3. Enriched surface acidity for surfactant-free suspensions of carboxylated carbon nanotubes purified by centrifugation

    Directory of Open Access Journals (Sweden)

    Elizabeth I. Braun

    2016-06-01

    Full Text Available It is well known that surfactant-suspended carbon nanotube (CNT samples can be purified by centrifugation to decrease agglomerates and increase individually-dispersed CNTs. However, centrifugation is not always part of protocols to prepare CNT samples used in biomedical applications. Herein, using carboxylated multi-walled CNTs (cMWCNTs suspended in water without a surfactant, we developed a Boehm titrimetric method for the analysis of centrifuged cMWCNT suspensions and used it to show that the surface acidity of oxidized carbon materials in aqueous cMWCNT suspensions was enriched by ∼40% by a single low-speed centrifugation step. This significant difference in surface acidity between un-centrifuged and centrifuged cMWCNT suspensions has not been previously appreciated and is important because the degree of surface acidity is known to affect the interactions of cMWCNTs with biological systems.

  4. Influence of blade angle distribution along leading edge on cavitation performance of a centrifugal pump

    Science.gov (United States)

    Xu, Y.; Tan, L.; Cao, S. L.; Wang, Y. C.; Meng, G.; Qu, W. S.

    2015-01-01

    The influence of blade angle distribution along leading edge on cavitation performance of centrifugal pumps is analysed in the present paper. Three sets of blade angle distribution along leading edge for three blade inlet angles are chosen to design nine centrifugal pump impellers. The RNG k-epsilon turbulence model and the Zwart-Gerber-Belamri cavitation model are employed to simulate the cavitation flows in centrifugal pumps with different impellers and the same volute. The numerical results are compared with the experimental data, and the comparison proves that the numerical simulation can accurately predict the cavitation performance of centrifugal pumps. On the basis of the numerical simulations, the pump head variations with pump inlet pressure, and the flow details in centrifugal pump are revealed to demonstrate the influence of blade angle distribution along leading edge on cavitation performances of centrifugal pumps.

  5. Evaluación de factores camión de los vehículos comerciales de carga que circulan por la red vial principal colombiana

    Directory of Open Access Journals (Sweden)

    Luis F. Macea

    2013-01-01

    Full Text Available La estimación del tránsito es uno de los aspectos más importantes en el análisis y diseño estructural de pavimentos y para su adecuada determinación se hace necesario disponer de valores de factor camión actualizados. En el presente estudio se evaluaron los factores camión de los vehículos comerciales de carga de la red vial primaria de Colombia. Con este objetivo, en el año 2011 se realizaron treinta y ocho operativos móviles de pesaje de ejes en carretera, localizados en distintos puntos estratégicos de la red vial nacional. Como resultado se obtuvo, a través de procedimientos estadísticos, factores camión actualizados y representativos para cada tipo de camión que circula en las vías analizadas. Estos factores camión podrían ser utilizados en el diseño de tramos carreteros con características socioeconómicas similares a aquellas de las vías evaluadas. De igual forma, se encontró que a nivel nacional la flota vehicular de carga está compuesta por los camiones tipo C3-S3, C2, C3-S2, C3 y C2-S2 con una distribución del 36%, 35%, 13%, 11% y 5%, respectivamente. Adicionalmente, se observó que los camiones C3 y C3-S3 son los que mayor daño le causan a la infraestructura vial colombiana, ya que se encuentran circulando excesivamente sobrecargados en algunos tramos departamentales del país.

  6. Infraestructura Vial y crecimiento económico: Caso Parroquias Sevilla Don Bosco y San Isidro, Provincia de Morona Santiago, Ecuador

    OpenAIRE

    Zurita Vaca, Mauricio; Universidad Nacional de Chimborazo- Riobamba, Ecuador; Amboya Soqueb, Renato; Universidad Nacional de Chimborazo- Riobamba, Ecuador; Barba Castro, Elizabeth; Universidad Nacional de Chimborazo- Riobamba, Ecuador

    2016-01-01

    RESUMENLas parroquias mencionadas en esta investigación son eminentemente agrícolas y han mostrado un crecimiento de su producción en los últimos años gracias al cultivo de tubérculos (yuca y malanga) destinados a la exportación, esta situación se complementa con la ejecución de proyectos de asfaltado de carreteras por parte del Gobierno Autónomo de Morona Santiago, por ello la investigación realizada se canalizó hacia la determinación del nivel de influencia de esta infraestructura vial sobr...

  7. Beneficios económicos de Transmetro sobre la reducción de la accidentalidad vial en el área metropolitana de Barranquilla, Colombia

    OpenAIRE

    José Andrés Perdomo Calvo; María Cristina Arzuza Picon

    2015-01-01

    El principal objetivo de este documento es examinar la reducción de la accidentalidad vial en el área metropolitana de Barranquilla (AMBAQ), Colombia, a partir de la implementación del bus de tránsito rápido (BTR) Transmetro, y estimar económicamente los beneficios sociales debidos a la disminución de muertes y heridos por accidentes de tránsito en esta área entre 2010 y 2011. Con este propósito, se emplearon los lineamientos teóricos sobre externalidades en economía del transporte y un análi...

  8. Cursos de reeducación vial como estrategia para evitar accidentes de tráfico: estudio de la actitud de los participantes hacia estos cursos

    OpenAIRE

    Suriá Martínez, Raquel

    2012-01-01

    El objetivo de este estudio examina la valoración que hacen los conductores sancionados que participan en los cursos de reeducación vial sobre el Sistema de Permiso por Puntos, como estrategia para sustituir sus conductas infractoras por conductas adecuadas, asimismo, examinamos la apreciación de los aspectos positivos y negativos que perciben de dichos cursos. Participaron 240 infractores de los cursos de reeducación y sensibilización impartidos en las Aautoescuelas de la provincia de Alican...

  9. Quantification of platelets obtained by different centrifugation protocols in SHR rats

    Directory of Open Access Journals (Sweden)

    João Alberto Yazigi Junior

    2015-12-01

    Full Text Available ABSTRACT OBJECTIVE: To quantify the platelet concentration in the blood of SHR rats, by means of different centrifugation protocols, and to evaluate what the most effective method for obtaining platelets is. METHODS: We used 40 male rats of the isogenic SHR lineage. The animals were divided into three groups: control, using whole blood without centrifugation; single centrifugation, using whole blood subjected to a single centrifugation at 200 × gand 400 × g; and double centrifugation, using whole blood subjected one centrifugation at different rotations, followed by collection of whole plasma subjected to another centrifugation at different rotations: 200 × g+ 200 ×g; 200 × g+ 400 × g; 200 × g+ 800 × g; 400 ×g+ 400 × g; 400 × g+ 800 × g. Samples of 3 ml of blood were drawn from each animal by means of cardiac puncture. The blood was stored in Vacutainer collection tubes containing 3.2% sodium citrate. The blood from the control group animals was analyzed without being subjected to centrifugation. After the blood from the other groups of animals had been subjected to centrifugation, the whole plasma was collected and subjected to platelet counting in the lower third of the sample. RESULTS: We obtained greatest platelet enrichment in the subgroup with two centrifugations comprising 400 × gfor 10 min + 400 ×gfor 10 min, in which the mean platelet concentration was 11.30 times higher than that of the control group. CONCLUSION: It was possible to obtain a high platelet concentration using viable simple techniques, by means of centrifugation of whole blood and use of commonly used materials. The most effective method for obtaining platelet concentrate was found in samples subjected to two centrifugations.

  10. Effect of Mould Wall Thickness on Rate of Solidification of Centrifugal Casting

    OpenAIRE

    Madhusudhan; Narendranaath S; S, Mohankumar G C; Mukunda P G

    2010-01-01

    In Centrifugal Casting process the centrifugal force presses the metal against the inner wall of the metal mould, resulting in rapid solidification of the molten metal. However the solidification structures like structural uniformity and structural character of the solidified metal of centrifugal casting is of great importance, regarding to its mechanical properties. The solidification time of the casting is dependent upon the various parameters like speed ofrotation of the mold, mould wall t...

  11. Mathematical Modeling of Nonstationary Separation Processes in Gas Centrifuge Cascade for Separation of Multicomponent Isotope Mixtures

    Directory of Open Access Journals (Sweden)

    Orlov Alexey

    2016-01-01

    Full Text Available This article presents results of development of the mathematical model of nonstationary separation processes occurring in gas centrifuge cascades for separation of multicomponent isotope mixtures. This model was used for the calculation parameters of gas centrifuge cascade for separation of germanium isotopes. Comparison of obtained values with results of other authors revealed that developed mathematical model is adequate to describe nonstationary separation processes in gas centrifuge cascades for separation of multicomponent isotope mixtures.

  12. Gender Differences in Cardiovascular Tolerance to Short Arm Centrifugation

    Science.gov (United States)

    Fong, Kevin J.; Arya, Maneesh; Paloski, William H.

    2007-01-01

    In preparation for the NASA Artificial Gravity (AG) pilot study, the tolerability of the proposed AG parameters was tested in 11 ambulatory human subjects (6m, 5w) by exposing each to a short arm centrifuge trial. Subjects were oriented in the supine position (but inclined 6deg head down) on one arm of the centrifuge, and the rotation rate (30.6-33.4 rpm) and radial position of the feet were set to produce 2.5G of equivalent gravitational load at the force plate directly beneath the feet, 1G at the level of the mediastinum, and approximately 0.55G at the labyrinth. Amongst the 6 men participating in this preliminary study, 5 completed at least 60 minutes of the trial successfully with no adverse sequelae. However, amongst the female cohort the test was stopped by the medical monitor before 60 min in all but one case, with pre-syncope listed as the reason for termination in all cases. Mean time before abort of the centrifuge run amongst the women was 33.2 +/- 20.97 min. It is known that women have a greater predisposition to syncope during orthostatic stress, under normal tilt table conditions, during LBNP, and following space flight. The reasons for this difference are the subject of some debate, but anthropometric factors, the vasoactive effects of sex hormones, gender differences in susceptibility to motion sickness, catecholamine levels, ability to augment total peripheral resistance in response to orthostatic stress, and structural differences in cardiac anatomy and physiology have all been suggested. This finding led to the exclusion of women from the AG pilot study. Clearly if AG is to be employed as a multi-system countermeasure it must provide physiological protection at rotation rates within the tolerance limits of all potential astronauts. Further investigation of the responses of women to centrifugation will be necessary to determine how to adjust AG parameters for tolerance by female subjects before a more detailed investigation of the appropriate dose

  13. Centrifuge modelling of rigid piles in soft clay

    DEFF Research Database (Denmark)

    Klinkvort, R.T.; Poder, M.; Truong, P.

    2016-01-01

    of this study is to employ centrifuge modelling in order to derive experimental p-y curves for rigid piles embedded in over-consolidated soft clay. A kaolin clay sample was prepared and pre-consolidated by applying a constant pressure at the soil surface, while different over-consolidation ratios were achieved...... within the clay sample by carrying out the experiments at different g fields. The findings suggest that the normalised shape of the p-y curves can be predicted within a sufficient accuracy using the current methodology but that the ultimate lat-eral resistance is underestimated at shallow depths...

  14. Preliminary report: a pregnancy from frozen centrifuged dog semen.

    Science.gov (United States)

    Oettlé, E E

    1982-12-01

    Semen obtained from a pure-bred Beagle was diluted 1:3 with a Tris (hydroxymethyl) - aminomethane buffered egg yolk diluent, centrifuged at 450 g for 10 minutes and the spermatozoa thus concentrated stored in 8 Cassou mini straws (0,25 ml) in liquid nitrogen. One month after collection, a single semen straw was thawed, rediluted with 4 ml of diluent containing no glycerol and inseminated into a Beagle in oestrus. This was repeated daily for 4 days. The vagina of the bitch was flushed with 4 ml of the diluent immediately prior to insemination on each occasion. The bitch whelped 7 pups 60 days after the first insemination.

  15. Rapid, low-cost prototyping of centrifugal microfluidic devices for effective implementation of various microfluidic components

    Directory of Open Access Journals (Sweden)

    Smith, Suzanne

    2015-05-01

    Full Text Available A centrifugal microfluidic platform to develop various microfluidic operations – the first of its kind in South Africa – is presented. Rapid and low-cost prototyping of centrifugal microfluidic disc devices, as well as a set-up to test the devices using centrifugal forces, is described. Preliminary results show that various microfluidic operations such as fluidic valving, transportation, and microfluidic droplet generation can be achieved. This work provides a complete centrifugal microfluidic platform and the building blocks on which to develop a variety of microfluidic applications and potential products rapidly and at a low cost.

  16. Extended residence time centrifugal contactor design modification and centrifugal contactor vane plate valving apparatus for extending mixing zone residence time

    Science.gov (United States)

    Wardle, Kent E.

    2017-06-06

    The present invention provides an annular centrifugal contactor, having a housing adapted to receive a plurality of flowing liquids; a rotor on the interior of the housing; an annular mixing zone, wherein the annular mixing zone has a plurality of fluid retention reservoirs with ingress apertures near the bottom of the annular mixing zone and egress apertures located above the ingress apertures of the annular mixing zone; and an adjustable vane plate stem, wherein the stem can be raised to restrict the flow of a liquid into the rotor or lowered to increase the flow of the liquid into the rotor.

  17. Performance Optimization of Centrifugal Pump for Crude Oil Delivery

    Directory of Open Access Journals (Sweden)

    S.A.I. Bellary

    2018-02-01

    Full Text Available Crude oil transport is an essential task in oil and gas industries, where centrifugal pumps are extensively used. The design of a centrifugal pump involves a number of independent parameters which affect the pump performance. Altering some of the parameters within a realistic range improves pump performance and saves a significant amount of energy. The present research investigated the pump characteristics by modifying the number of blades and the exit blade-angles. Reynolds-Averaged Navier-Stokes equations with standard k-ε two-equation turbulence closure were used for steady and incompressible flow of crude oil through the pump. The experimental set-up was installed and the pump performance calculated numerically  was compared with the experiments.   The investigations showed that the number of blades and the exit blade-angles have a significant influence on the head, shaft power, and efficiency. The vortical flow structures, recirculation and reverse flow characteristics around the impeller were investigated to explain the flow dynamics of impeller and casing. A larger number of blades on the rotor showed dominant streamlined flow without any wake phenomena. The combined effect of the number of blades and exit blade angle has led to an increase in head and efficiency through the parametric optimization.

  18. Flow in a Low Specific Speed Centrifugal Pump Using PIV

    Directory of Open Access Journals (Sweden)

    Cui Dai

    2013-01-01

    Full Text Available The interflow plays important roles in centrifugal pump design. In order to study the effect of rotation and z-axis on internal flow, two-dimensional particle image velocimetry (PIV measurements have been performed to measure the steady velocity field on three planes in all impeller passages of a low specific-speed centrifugal pump. The results show that the relative velocity flows in blade passages are obviously different in terms of the positions of the blade relative to the tongue. The interaction between the impeller and tongue changes the occurrence and development of low velocity region with time. From shroud to hub, the relative velocity gradually increases, and the minimum value moves toward the suction surface. On the midplane, the magnitude increases with increased flow rate from pressure surface to suction surface, while at the shroud and hub, the measured velocity first increases with decreased flow rate from the blade pressure surface to nearly ζ = 0.5 to 0.6.

  19. Numerical Calculation on Cavitation Pressure Pulsation in Centrifugal Pump

    Directory of Open Access Journals (Sweden)

    Weidong Shi

    2014-02-01

    Full Text Available In order to study the internal flow in centrifugal pump when cavitation occurs, numerical calculation of the unsteady flow field in the WP7 automobile centrifugal pump is conducted based on the Navier-Stokes equations with the RNG k – ε turbulence model and Zwart-Gerber-Belamri cavitation model. The distributions of bubble volume fraction and pressure pulsation laws in the pump are analyzed when cavitation occurs. The conclusions are as follows: the bubble volume fraction is larger on the suction side of impeller blade near the inlet edge, which is consistent with the low-pressure region distribution. Bubble volume is determined by the growth rate and collapse rate of every bubble in the bubble group. The cavitation degree changes over time with the impeller rotation and the bubble growth and collapse coexist in the impeller flow channels. The main pulsation results from the cyclic and static coupling between the impeller and the tongue, while the fluctuating amplitude is increased by the cavitation.

  20. [Preparation of Shuxiong micropellets by centrifugal granulation technology].

    Science.gov (United States)

    Song, Hong-Tao; Zhang, Qian; Kong, Lu-Ling; Chen, Da-Wei; He, Zhong-Gui

    2006-07-01

    To prepare shuxiong micropellets. Shuxiong micropellets were prepared by using a centrifugal granulator. The formulation composition and process factors were optimized investigated by adopting several indices such as size distribution, repose angle, bulk density and friability as indexes. The optimal process parameters were as follows. The ratio of fine intermediate product and MCC was 3:1 (w/w), the adhesive agent was 3% HMPC solution, the rotating rate of plate was 200 r x min(-1), the blower rate was 15 x 20 L x min(-1), the rate of air flow was 15 L x min(-1), the spray air pressure was 0.5 MPa, the rotating of spray solution pump was 5-25 r x min(-1) and the rotating rate of powder feed machine was 5-25 r x min(-1). Under the optimal conditions, micropellets prepared by using centrifugal granulator hadpossessed prefect shape and surface characteristics and the yield of shuxiong pellets was 90.5%.

  1. Numerical Study of Unsteady Flow in Centrifugal Cold Compressor

    Science.gov (United States)

    Zhang, Ning; Zhang, Peng; Wu, Jihao; Li, Qing

    In helium refrigeration system, high-speed centrifugal cold compressor is utilized to pumped gaseous helium from saturated liquid helium tank at low temperature and low pressure for producing superfluid helium or sub-cooled helium. Stall and surge are common unsteady flow phenomena in centrifugal cold compressors which severely limit operation range and impact efficiency reliability. In order to obtain the installed range of cold compressor, unsteady flow in the case of low mass flow or high pressure ratio is investigated by the CFD. From the results of the numerical analysis, it can be deduced that the pressure ratio increases with the decrease in reduced mass flow. With the decrease of the reduced mass flow, backflow and vortex are intensified near the shroud of impeller. The unsteady flow will not only increase the flow loss, but also damage the compressor. It provided a numerical foundation of analyzing the effect of unsteady flow field and reducing the flow loss, and it is helpful for the further study and able to instruct the designing.

  2. Concrete Cleaning, Inc. centrifugal shot blaster: Baseline report; Greenbook (chapter)

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-07-31

    The centrifugal shot blaster technology was tested and is being evaluated at Florida International University (FIU) as a baseline technology. In conjunction with FIU`s evaluation of efficiency and cost, this report covers the evaluation conducted for safety and health issues. It is a commercially available technology and has been used for various projects at locations throughout the country. The centrifugal shot blaster is an electronically operated shot blast machine that has been modified to remove layers of concrete to varying depths. A hardened steel shot propelled at a high rate of speed abrades the surface of the concrete. The depth of material removed is determined by the rate of speed the machine is traveling and the volume of shot being fired into the blast chamber. The steel shot is recycled and used over until it is pulverized into dust, which ends up in the waste container with the concrete being removed. Debris is continually vacuumed by a large dust collection system attached to the shot blaster. The safety and health evaluation during the human factors assessment focused on two main areas: noise and dust.

  3. Concrete Cleaning, Inc. centrifugal shot blaster: Baseline report

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-07-31

    The centrifugal shot blaster technology was tested and is being evaluated at Florida International University (FIU) as a baseline technology. In conjunction with FIU`s evaluation of efficiency and cost, this report covers the evaluation conducted for safety and health issues. It is a commercially available technology and has been used for various projects at locations throughout the country. The centrifugal shot blaster is an electronically operated shot blast machine that has been modified to remove layers of concrete to varying depths. A hardened steel shot propelled at a high rate of speed abrades the surface of the concrete. The depth of material removed is determined by the rate of speed the machine is traveling and the volume of shot being fired into the blast chamber. The steel shot is recycled and used over until it is pulverized into dust, which ends up in the waste container with the concrete being removed. Debris is continually vacuumed by a large dust collection system attached to the shot blaster. The safety and health evaluation during the human factors assessment focused on two main areas: noise and dust.

  4. Centrifuge modeling of buried continuous pipelines subjected to normal faulting

    Science.gov (United States)

    Moradi, Majid; Rojhani, Mahdi; Galandarzadeh, Abbas; Takada, Shiro

    2013-03-01

    Seismic ground faulting is the greatest hazard for continuous buried pipelines. Over the years, researchers have attempted to understand pipeline behavior mostly via numerical modeling such as the finite element method. The lack of well-documented field case histories of pipeline failure from seismic ground faulting and the cost and complicated facilities needed for full-scale experimental simulation mean that a centrifuge-based method to determine the behavior of pipelines subjected to faulting is best to verify numerical approaches. This paper presents results from three centrifuge tests designed to investigate continuous buried steel pipeline behavior subjected to normal faulting. The experimental setup and procedure are described and the recorded axial and bending strains induced in a pipeline are presented and compared to those obtained via analytical methods. The influence of factors such as faulting offset, burial depth and pipe diameter on the axial and bending strains of pipes and on ground soil failure and pipeline deformation patterns are also investigated. Finally, the tensile rupture of a pipeline due to normal faulting is investigated.

  5. Centrifuge modeling of rocking-isolated inelastic RC bridge piers

    Science.gov (United States)

    Loli, Marianna; Knappett, Jonathan A; Brown, Michael J; Anastasopoulos, Ioannis; Gazetas, George

    2014-01-01

    Experimental proof is provided of an unconventional seismic design concept, which is based on deliberately underdesigning shallow foundations to promote intense rocking oscillations and thereby to dramatically improve the seismic resilience of structures. Termed rocking isolation, this new seismic design philosophy is investigated through a series of dynamic centrifuge experiments on properly scaled models of a modern reinforced concrete (RC) bridge pier. The experimental method reproduces the nonlinear and inelastic response of both the soil-footing interface and the structure. To this end, a novel scale model RC (1:50 scale) that simulates reasonably well the elastic response and the failure of prototype RC elements is utilized, along with realistic representation of the soil behavior in a geotechnical centrifuge. A variety of seismic ground motions are considered as excitations. They result in consistent demonstrably beneficial performance of the rocking-isolated pier in comparison with the one designed conventionally. Seismic demand is reduced in terms of both inertial load and deck drift. Furthermore, foundation uplifting has a self-centering potential, whereas soil yielding is shown to provide a particularly effective energy dissipation mechanism, exhibiting significant resistance to cumulative damage. Thanks to such mechanisms, the rocking pier survived, with no signs of structural distress, a deleterious sequence of seismic motions that caused collapse of the conventionally designed pier. © 2014 The Authors Earthquake Engineering & Structural Dynamics Published by John Wiley & Sons Ltd. PMID:26300573

  6. Centrifuge modeling of rocking-isolated inelastic RC bridge piers.

    Science.gov (United States)

    Loli, Marianna; Knappett, Jonathan A; Brown, Michael J; Anastasopoulos, Ioannis; Gazetas, George

    2014-12-01

    Experimental proof is provided of an unconventional seismic design concept, which is based on deliberately underdesigning shallow foundations to promote intense rocking oscillations and thereby to dramatically improve the seismic resilience of structures. Termed rocking isolation , this new seismic design philosophy is investigated through a series of dynamic centrifuge experiments on properly scaled models of a modern reinforced concrete (RC) bridge pier. The experimental method reproduces the nonlinear and inelastic response of both the soil-footing interface and the structure. To this end, a novel scale model RC (1:50 scale) that simulates reasonably well the elastic response and the failure of prototype RC elements is utilized, along with realistic representation of the soil behavior in a geotechnical centrifuge. A variety of seismic ground motions are considered as excitations. They result in consistent demonstrably beneficial performance of the rocking-isolated pier in comparison with the one designed conventionally. Seismic demand is reduced in terms of both inertial load and deck drift. Furthermore, foundation uplifting has a self-centering potential, whereas soil yielding is shown to provide a particularly effective energy dissipation mechanism, exhibiting significant resistance to cumulative damage. Thanks to such mechanisms, the rocking pier survived, with no signs of structural distress, a deleterious sequence of seismic motions that caused collapse of the conventionally designed pier. © 2014 The Authors Published by John Wiley & Sons Ltd.

  7. Human ES cells: Starting Culture from Frozen Cells

    OpenAIRE

    Trish, Erin; Dimos, John; Eggan, Kevin

    2006-01-01

    Here we demonstrate how our lab begins a HuES human embryonic stem cell line culture from a frozen stock. First, a one to two day old ten cm plate of approximately one (to two) million irradiated mouse embryonic fibroblast feeder cells is rinsed with HuES media to remove residual serum and cell debris, and then HuES media added and left to equilibrate in the cell culture incubator. A frozen vial of cells from long term liquid nitrogen storage or a -80C freezer is sourced and quickly submer...

  8. Cardio-postural interactions and short-arm centrifugation.

    Science.gov (United States)

    Blaber, Andrew; Goswami, Nandu; Xu, Da; Laurin, Alexendre

    INTRODUCTION: We are interested in mechanisms associated with orthostatic tolerance. In previous studies we have shown that postural muscles in the calf contribute to both posture and blood pressure regulation during orthostatic stress. In this study we investigated the relationship between cardiovascular and postural muscle control before, during and after short arm human centrifuge (SAHC) up to 2.2 G. METHODS: Eleven healthy young subjects (6 m, 5 f), with no history of cardiovascular disease, falls or orthostatic hypotension, participated. All were familiarized with the SAHC with 10 minutes at 1-G at the feet. Each subject was instrumented in the supine position on the SAHC for beat-to-beat ECG and blood pressure (Portapres derived SBP). Bilateral lower leg EMG was collected from four leg postural muscles: tibialis anterior, medial gastrocnemius, lateral gastrocnemius, and medial soleus. Transdermal differential recording of signals was performed using an 8-channel EMG system, (Myosystem 1200, Noraxon Inc., Arizona, USA). Postural sway data of the body COP was computed from the force and moment data collected with a force platform (Accusway, AMTI, MA, USA). Before and after SAHC, the subject stood on a force platform with their gaze fixed on a point at eye level, closed their eyes and stood quietly for 5 min. A final stand was conducted 30 min after centrifugation with supine rest in between. During clockwise centrifugation (10-min 1g and 10-min 2.2g at the foot) the subjects’ head was hooded and in the dark. The subject’s body was restrained into the rotation arm with a parachute harness and given additional body support with a foot-plate. ECG, EMG and BP data were collected throughout and centre of pressure trajectory (COP) collected during the stand test. Subjects were requested to relax and not to voluntarily contract the leg muscles; however, they were not to suppress contractions as they occurred involuntarily or by reflex. A Continuous Wavelet

  9. Aislamiento rápido del virus dengue 3 por el método de shell vial en el brote de dengue en Lima

    Directory of Open Access Journals (Sweden)

    Victoria Gutiérrez P

    2005-07-01

    Full Text Available El aislamiento de virus dengue con los métodos tradicionales demora hasta un mes, en situaciones de emergencia como el brote de dengue clásico en el distrito de Comas-Lima entre abril y mayo de 2005, es necesario un diagnóstico precoz. Se procesaron 117 muestras de sueros de pacientes con diagnóstico clínico de dengue clásico en fase virémica procedentes la zona del brote, mediante el método de shell vial para el aislamiento del virus dengue en la línea celular C6-36, se identificó el serotipo del virus mediante inmunofluorescencia indirecta (IFI empleando anticuerpos monoclonales. Se logró el aislamiento del virus DEN-3 al quinto día de cosecha en el 48,7% (57/117 de los sueros. Los resultados sugieren que el método de shell vial, por el menor tiempo de aislamiento que el método tradicional, puede ser implementado como método de diagnóstico y usado en la vigilancia epidemiológica del virus dengue.

  10. Application of in-vial membrane assisted solvent extraction to the determination of polycyclic aromatic hydrocarbons in seawater by gas chromatography-mass spectrometry.

    Science.gov (United States)

    March, J G; Moukhchan, F; Cerdà, V

    2011-01-31

    A device for membrane assisted solvent extraction from an aqueous sample to an organic solvent within a micro-vial compatible with a chromatography auto-sampler was used to extract trace amounts of seven polycyclic aromatic hydrocarbons from seawater. The device consisted in an assembly of a volumetric flask containing the sample and a micro-vial containing the organic solvent by means of a screw stopper in which the septum was replaced by a sized piece of a membrane. Extraction conditions (nature of the organic solvent, extraction time, presence of ethanol in the donor phase, ionic content of the donor phase, characteristics of the membrane and volumes of donor and acceptor phases) were studied in order to find the conditions for maximum extraction. Analytical performance characteristics have also been established. The extraction efficiency was between 12.5 and 23%, which implies an enrichment factor value above 40. The repeatability and reproducibility were in the range of 8.6-10.0% and 13-19%, respectively. Detection limits were in the range of 24-39 ng L(-1). Nine seawater samples have been studied. Most of the concentrations were under the limits of detection. Naphthalene and phenanthrene contents have been determined in a sample using the method of standard additions, and concentrations 100 and 91 ng L(-1), respectively. Copyright © 2010 Elsevier B.V. All rights reserved.

  11. Extended stability of the rituximab biosimilar CT-P10 in its opened vials and after dilution and storage in polyolefin bags.

    Science.gov (United States)

    Vieillard, V; Paul, M; Ibrahim, T; Astier, A

    2017-11-01

    The stability of the rituximab biosimilar CT-P10, in 50mL vials at a concentration of 10mg/mL, and after dilution to final concentrations of 1 and 4mg/mL and storage in polyolefin bags at 4°C and 25°C was studied by several orthogonal and complementary methods. No significant change (as defined by a magnitude greater than the inter-batch variability) was observed, for each of the parameters characterizing physical and chemical stability studied, for the two concentrations and temperatures tested, or for any of the three batches tested. This implies that cold-chain rupture and exposure to room temperature up to 15 days both for vials and diluted bags have no deleterious consequence on the quality of the product. Moreover, this extended stability permits safe in-advance preparation, dose-banding or flat-dose, that to avoid unnecessary delays in the management of the patient, improvement of the pharmacy and nurse workload and money saving by avoiding non justified losses of this expensive drug. Copyright © 2017 Académie Nationale de Pharmacie. Published by Elsevier Masson SAS. All rights reserved.

  12. Beneficios económicos de Transmetro sobre la reducción de la accidentalidad vial en el área metropolitana de Barranquilla, Colombia

    Directory of Open Access Journals (Sweden)

    Jorge Perdomo

    2015-01-01

    Full Text Available El principal objetivo de este documento es examinar la reducción de la accidentalidad vial en el área metropolitana de Barranquilla (AMBAQ, Colombia, a partir de la implementación del bus de tránsito rápido (BTR Transmetro, y estimar económicamente los beneficios sociales debidos a la disminución de muertes y heridos por accidentes de tránsito en esta área entre 2010 y 2011. Con este propósito, se emplearon los lineamientos teóricos sobre externalidades en economía del transporte y un análisis cuantitativo, mediante información secundaria, a través de modelos de series de tiempo ARIMAX con cambio estructural y el valor estadístico de la vida por accidentalidad vial en Colombia. De este modo, se determinó que el beneficio agregado anual por disminución de muertes en accidentes de tránsito en el AMBAQ en 2011 fue de $3.553’216.056, y para heridos graves fue de $13.732’882.320 aproximadamente.

  13. The impact of cushioned centrifugation protocols on semen quality of stallions.

    Science.gov (United States)

    Bliss, S B; Voge, J L; Hayden, S S; Teague, S R; Brinsko, S P; Love, C C; Blanchard, T L; Varner, D D

    2012-04-01

    The objective was to determine if decreased cushion-fluid volume and increased sperm number during centrifugation, or if sperm concentration of extended semen following centrifugation, affected stallion sperm quality. Three ejaculates from each of three stallions were subjected to cushioned centrifugation (1,000g for 20 min). Cushion-fluid volume was set at 1 or 3.5 ml, and sperm number per centrifuge tube was set 1 billion or 3 billion. Following centrifugation, sperm pellets were resuspended in semen extender containing 20% seminal plasma (v/v) with sperm concentrations of 25 or 250 million/mL. Sperm recovery rate among centrifugation treatment groups was compared. Motion characteristics, plasma membrane intactness (SMI), and DNA quality (COMPαt) of sperm were compared among treatment groups and uncentrifuged controls immediately following centrifugation (Time 0 h) and following 24 h of cooled storage (Time 24 h). Centrifugation treatment did not affect sperm recovery rate (P > 0.05). At Time 0 h, no differences in experimental end points were detected between cushion-fluid volumes tested (P > 0.05). Values for percent total sperm motility, percent progressive sperm motility, and track straightness were similar between sperm-number treatments subjected to centrifugation (P > 0.05). At Time 24 h, values for all experimental endpoints were similar between centrifugation treatments for cushion volume per tube, and between centrifugation treatments for sperm number per tube (P > 0.05). Centrifugation treatments and control treatments were similar for five of six variables tested (P > 0.05). Sperm storage concentrations of 25 × 10(6) and 250 × 10(6)/mL yielded similar values for percent total sperm motility, percent progressive sperm motility, percent SMI, and percent COMPαt (P > 0.05). A storage concentration of 250 × 10(6) sperm/ml yielded higher values for curvilinear velocity, and lower values for straightness, than all other groups (P < 0.05). In conclusion

  14. A Shandon PapSpin liquid-based gynecological test: A split-sample and direct-to-vial test with histology follow-up study

    Directory of Open Access Journals (Sweden)

    Rimiene J

    2010-01-01

    Full Text Available Background: Studies for liquid-based Papanicolaou (Pap tests reveal that liquid-based cytology (LBC is a safe and effective alternative to the conventional Pap smear. Although there is research on ThinPrep and SurePath systems, information is lacking to evaluate the efficiency and effectiveness of systems based on cytocentrifugation. This study is designed to determine the sensitivity and specificity of the Shandon PapSpin (ThermoShandon, Pittsburgh, Pennsylvania, USA liquid-based gynecological system. We used split-sample and direct-to-vial study design. Materials and Methods: 2,945 women referred to prophylactic check-up were enrolled in this study. Split sample design was used in 1,500 women and residual cervical cytology specimen from all these cases was placed in fluid for PapSpin preparation after performing conventional smear. The direct-to-vial study was carried out in another cohort of 1,445 women in whom the entire cervical material was investigated using only the PapSpin technique. Follow up histological diagnoses for 141 women were obtained from both study arms following 189 abnormal cytology cases. 80 LBC cases from the split sample group and 61 LBC cases in the direct-to-vial group were correlated with the histology results. The sensitivity and secificity of the conventional smear and PapSpin tests in both study arms were compared. Results: In the split sample group, conventional smears showed a higher proportion of ASC-US (atypical cells undetermined significance: 31 (2.1% vs 10 (0.7% in PapSpin (P = 0.001. A higher proportion of unsatisfactory samples was found in the conventional smear group: 25 (1.7% vs 6 (0.4% cases (P = 0.001. In the split sample group, the sensitivity of the conventional and PapSpin tests was 68.7% vs 78.1%, and the specificity 93.8% vs 91.8%, respectively. In the direct to vial group PapSpin sensitivity was 75.9% and specificity 96.5%. The differences in sensitivity and specificity were not significant. The

  15. Incidence of electrocardiographic changes during cytapheresis using an intermittent flow centrifuge, haemonetics V50 and a continuous flow centrifuge, AS104.

    Science.gov (United States)

    Komatsu, F; Kajiwara, M

    1997-03-01

    Electrocardiographic (ECG) monitoring was performed during cytapheresis and the incidence of ECG changes was compared between methods of intermittent flow centrifugation using the Haemonetics V50 with apheresis donors and continuous flow centrifugation with the AS104 for peripheral blood stem cell (PBSC) collection from patients. ST depression, inverted T wave and other ECG changes were found in 49 (14.3%) of the 342 cytaphereses carried out by the intermittent flow centrifugation method and in 8 (4.7%) of the 169 PBSC collections by the continuous flow centrifugation method. This difference was significant (P < 0.05). The hemodynamic changes in the procedure with the AS104 seem to be small. This is considered to be important for prevention of serious ST and T wave changes.

  16. Aplicación de los Sistemas de Información Geográfica para la gestión de la malla vial de la ciudad de Medellín

    Directory of Open Access Journals (Sweden)

    Jaime A. Zapata Duque

    2012-12-01

    Full Text Available El estado de la malla vial depende fundamentalmente de factores tales como el tráfico, características estructurales y funcionales del pavimento y condiciones climatológicas locales, y su mantenimiento tiene importantes implicaciones espaciales. Este documento describe el proceso de implementación del sistema de gestión de pavimentos de la ciudad de Medellín, desarrollado en una plataforma SIG. El sistema está soportado en una geodatabase corporativa de inventario y diagnóstico, el cual alimenta un software de modelación del deterioro del pavimento y arroja recomendaciones de intervención en cada segmento vial. Este sistema sirve como apoyo a las autoridades encargadas a la toma de decisiones, con el fin de realizar la planeación del mantenimiento de la malla vial, optimizar los recursos disponibles y ofrecer un mejor servicio a la comunidad.

  17. Diseño del subsistema de reclutamiento selección e inducción de la Comisión Nacional de Transito, Transporte Terrestre y Seguridad Vial

    OpenAIRE

    Atapuma Ramos, Diana Carolina; Armas Lasso, Elsa Michelle

    2012-01-01

    Mediante Ley Orgánica de Transporte Terrestre, Tránsito y Seguridad Vial, promulgada el 24 de julio del 2008 y publicada en el Registro Oficial No. 398 del 7 de agosto del mismo año; la Comisión Nacional del Transporte Terrestre, Tránsito y Seguridad Vial, es el ente encargado de la regulación y control del Transporte Terrestre, Tránsito y Seguridad Vial en el país; dicha institución es una entidad autónoma de derecho público con personería jurídica, jurisdicción nacional, p...

  18. THEORETICAL FLOW MODEL THROUGH A CENTRIFUGAL PUMP USED FOR WATER SUPPLY IN AGRICULTURE IRRIGATION

    Directory of Open Access Journals (Sweden)

    SCHEAUA Fanel Dorel

    2017-05-01

    motion of the rotor. A theoretical model for calculating the flow of the working fluid through the interior of a centrifugal pump model is presented in this paper as well as the numerical analysis on the virtual model performed with the ANSYS CFX software in order to highlight the flow parameters and flow path-lines that are formed during centrifugal pump operation.

  19. Numerical Calculation of the Three-Dimensional Swirling Flow Inside the Centrifugal Pump Volutes

    Directory of Open Access Journals (Sweden)

    E. Cezmi Nursen

    2003-01-01

    Full Text Available The flow inside the volute of a centrifugal pump is threedimensional and, depending upon the position of the inlet relative to the cross-section center line, a single or double swirling flow occurs. The purpose of this study was the calculation of the three-dimensional swirling flow inside the centrifugal pump volute.

  20. Sandia National Laboratories 8. 8 metre (29-foot) and 10. 7-metre (35-foot) centrifuge facilities

    Energy Technology Data Exchange (ETDEWEB)

    Adams, P.H.; Ault, R.L.; Fulton, D.L.

    1980-05-01

    This report outlines the capabilities and limitations of the two centrifuges and gives other details which must be considered in preparing test specifications and designing fixtures, gives the theory and terminology of centrifuge testing, and describes the layout, operating principles, support functions, and reference material for each facility.

  1. Platelet concentration of plateletrich plasma from dogs, obtained through three centrifugation speeds

    Directory of Open Access Journals (Sweden)

    Vanessa Couto de Magalhães Ferraz

    2007-12-01

    Full Text Available The platelets release at least 4 growth factors (Platelet Derived Growth Factor. ²1 and ²2 Transforming Growth Factors and Insulin-like Growth Factor which are responsible for the migration and activation of cells that will start the reparation of soft tissues and bones. The Platelet Rich Plasma is an autogenous source for Growth Factors, obtained by platelet concentration by centrifuging total blood. This study aimed the comparison of platelet concentrations in plasma centrifuged in three different centrifugation speeds (1300, 1600 e 3200rpm, for the production of platelet rich plasma. Blood was drowned from 15 dogs, 40ml of each, and these were divided into four groups and centrifuged at 800rpm. Then the first group was centrifuged at 1300rpm, the second at 1600rpm, the third at 3200rpm and the last was used as control, named plasma. The mean percentage increase in the platelet concentration for each technique was: 1300 - 183%, 1600 - 210% and 3200 - 222%. But in centrifugation at 3200 rpm, platelets presented altered morphology and different sizes in every sample studied, which was understood as severe cell damage. It was concluded that the best technique for the preparation of the platelet rich plasma in dogs consisted of the previous centrifugation of the blood at 800rpm for ten minutes, and then the plasma should be separated. This plasma is then submitted to a second centrifugation of 1600rpm for 10 minutes, and the platelet poor plasma is separated and discharged.

  2. Asymmetric hetero-assembly of colloidal nanoparticles through "crash reaction" in a centrifugal field.

    Science.gov (United States)

    Song, Sha; Kuang, Yun; Luo, Liang; Sun, Xiaoming

    2014-04-28

    Asymmetric hetero-assembly of two kinds of colloidal nanoparticles (NPs) was achieved by "crash reaction" in a density gradient centrifugation system using Au NPs as an example. Centrifugal force was applied to overcome the Brownian motion effect and cause NPs' directional movements. A water-oil interface was introduced to increase the effective collision probability.

  3. Effect of centrifugal fractionation protocols on quality and recovery rate of equine sperm.

    Science.gov (United States)

    Edmond, A J; Brinsko, S P; Love, C C; Blanchard, T L; Teague, S R; Varner, D D

    2012-03-15

    Centrifugal fractionation of semen is commonly done to improve quality of human semen in assisted-reproduction laboratories, allowing sperm separation based on their isopycnic points. Sperm with morphologic abnormalities are often more buoyant, promoting their retention above defined density media, with structurally normal sperm passing through the media following centrifugation. Three experiments were conducted to evaluate the effects of density-medium type, centrifuge-tube size, sperm number, and density-medium volume (column height) on stallion sperm quality and recovery rate in sperm pellets following centrifugation. In all three experiments, equine semen was initially centrifuged to increase sperm concentration. In Experiment 1, semen was layered over continuous or discontinuous gradients. For Experiment 2, semen was layered over three column heights of continuous gradients in 15- or 50-ml conical-bottom tubes. For Experiment 3, increasing sperm numbers were layered over continuous gradient in 15- or 50-ml conical-bottom tubes. Following centrifugation, sperm pellets were evaluated for sperm morphologic quality, motility, DNA integrity, and recovery rate. Centrifugal fractionation improved (P continuous gradient increased (P 0.05) by column height of gradient. Increasing sperm number subjected to gradient centrifugation decreased (P < 0.05) sperm recovery rate when 15-ml tubes were used. Copyright © 2012 Elsevier Inc. All rights reserved.

  4. Preparation of leukocyte-poor platelet concentrates from buffy coats. I. Special inserts for centrifuge cups

    NARCIS (Netherlands)

    Pietersz, R. N.; Reesink, H. W.; Dekker, W. J.; Fijen, F. J.

    1987-01-01

    A special insert was developed for centrifuge cups in order to prepare leukocyte-poor platelet concentrates from buffy coats by using quadruple citrate phosphate dextrose-saline adenine glucose mannitol systems from different manufacturers. Each centrifuge cup could contain up to 4 sets of double

  5. Vibration assessment for thrombus formation in the centrifugal pump.

    Science.gov (United States)

    Nakazawa, T; Makinouchi, K; Takami, Y; Glueck, J; Tayama, E; Nosé, Y

    1997-04-01

    To clarify the correlation of vibration and thrombus formation inside a rotary blood pump, 40 preliminary vibration studies were performed on pivot bearing centrifugal pumps. No such studies were found in the literature. The primary data acquisition equipment included an accelerometer (Isotron PE accelerometer, ENDEVCO, San Juan Capistrano, CA, U.S.A.), digitizing oscilloscope (TDS 420, Tektronix Inc., Pittsfield, MA, U.S.A.), and pivot bearing centrifugal pumps. The pump impeller was coupled magnetically to the driver magnet. The accelerometer was mounted on the top of the pump casing to sense radial and axial accelerations. To simulate the 3 common areas of thrombus formation, a piece of silicone rubber was attached to each of the following 3 locations as described: a circular shape on the center bottom of the impeller (CI), an eccentric shape on the bottom of the impeller (EI), and a circular shape on the center bottom casing (CC). A fast Fourier transform (FFT) method at 5 L/min against 100 mm Hg, with a pump rotating speed of 1,600 rpm was used. The frequency response of the vibration sensors used spans of 40 Hz to 2 kHz. The frequency domain was already integrated into the oscilloscope, allowing for comparison of the vibration results. The area of frequency domain at a radial direction was 206 +/- 12.7 mVHz in CI, 239.5 +/- 12.1 mVHz in EI, 365 +/- 12.9 mVHz in CC, and 163 +/- 7.9 mVHz in the control (control vs. CI p = 0.07, control vs. EI p < 0.001, control vs. CC p < 0.001, EI vs. CC p < 0.001, CI vs. CC p < 0.001). Three types of imitation thrombus formations were roughly distinguishable. These results suggested the possibility of detecting thrombus formation using vibration signals, and these studies revealed the usefulness of vibration monitoring to detect thrombus formation in a centrifugal pump.

  6. Stability of 10 mg/mL cefuroxime solution for intracameral injection in commonly used polypropylene syringes and new ready-to-use cyclic olefin copolymer sterile vials using the LC-UV stability-indicating method.

    Science.gov (United States)

    Feutry, Frédéric; Simon, Nicolas; Genay, Stéphanie; Lannoy, Damien; Barthélémy, Christine; Décaudin, Bertrand; Labalette, Pierre; Odou, Pascal

    2016-01-01

    Injecting intracameral cefuroxime has been found beneficial in reducing the risk of postoperative endophthalmitis but its use has been limited through a lack of approved marketing and of ready-to-use single-units as well as the problem of aseptic compounding. Our aim was to assess a new automated primary packaging system which should ensure a higher level of sterility, thanks to its closed, sterile, ready-to-use polymer vial called "Crystal® vial". The chemical stability of a 10 mg/mL cefuroxime solution was compared in 1 mL Crystal® vials and 1 mL Luer-lock polypropylene syringes (actual reference) to eliminate any potential and specific interactions with its cyclic olefin copolymer (COC) body and elastomer stopper. Cefuroxime solution was introduced into vials and syringes and stored at -20 °C, +5 °C and +25°C/60% Relative Humidity. Cefuroxime concentration and the relative amount of the main degradation product (descarbamoyl-cefuroxime) were both determined by an HPLC/UV method indicating stability. Solutions were considered steady if the concentration remained at over 90% of the initial value. In the adapted storage conditions, the evolution of osmolality, pH and sterility was assessed. Stability profiles were identical between vials and syringes in all storage and temperature conditions. The solution was stable (cefuroxime concentration, pH and osmolality) and still sterile for 365 days at -20°C. The concentration fell below 90% after 21 days at +5 °C and after 16 h at +25°C/60%s relative humidity. The COC and thermoplastic elastomer of the vials had no impact on the degradation process confirming its possible use for a ready-to-use cefuroxime solution single-unit dose.

  7. Automated cellular sample preparation using a Centrifuge-on-a-Chip.

    Science.gov (United States)

    Mach, Albert J; Kim, Jae Hyun; Arshi, Armin; Hur, Soojung Claire; Di Carlo, Dino

    2011-09-07

    The standard centrifuge is a laboratory instrument widely used by biologists and medical technicians for preparing cell samples. Efforts to automate the operations of concentration, cell separation, and solution exchange that a centrifuge performs in a simpler and smaller platform have had limited success. Here, we present a microfluidic chip that replicates the functions of a centrifuge without moving parts or external forces. The device operates using a purely fluid dynamic phenomenon in which cells selectively enter and are maintained in microscale vortices. Continuous and sequential operation allows enrichment of cancer cells from spiked blood samples at the mL min(-1) scale, followed by fluorescent labeling of intra- and extra-cellular antigens on the cells without the need for manual pipetting and washing steps. A versatile centrifuge-analogue may open opportunities in automated, low-cost and high-throughput sample preparation as an alternative to the standard benchtop centrifuge in standardized clinical diagnostics or resource poor settings.

  8. Column-centrifugation method for determining water retention curves of soils and disperse sediments

    Science.gov (United States)

    Smagin, A. V.

    2012-04-01

    A new instrumental method was proposed for the rapid estimation of the water-retention capacity of soils and sediments. The method is based on the use of a centrifugal field to remove water from distributed soil columns. In distinction from the classical method of high columns, the use of a centrifugal force field stronger than the gravity field allowed reducing the height of the soil samples from several meters to 10-20 cm (the typical size of centrifuge bags). In distinction from equilibrium centrifugation, the proposed method obtained an almost continuous water retention curve during the rotation of the soil column only at one-two centrifuge speeds. The procedure was simple in use, had high accuracy, and obtained reliable relationships between the capillary-sorption water potential and the soil water content in a wide range from the total water capacity to the wilting point.

  9. A cryogenic axial-centrifugal compressor for superfluid helium refrigeration

    CERN Document Server

    Decker, L; Schustr, P; Vins, M; Brunovsky, I; Lebrun, P; Tavian, L

    1997-01-01

    CERN's new project, the Large Hadron Collider (LHC), will use superfluid helium as coolant for its high-field superconducting magnets and therefore require large capacity refrigeration at 1.8 K. This may only be achieved by subatmospheric compression of gaseous helium at cryogenic temperature. To stimulate development of this technology, CERN has procured from industry prototype Cold Compressor Units (CCU). This unit is based on a cryogenic axial-centrifugal compressor, running on ceramic ball bearings and driven by a variable-frequency electrical motor operating under low-pressure helium at ambient temperature. The machine has been commissioned and is now in operation. After describing basic constructional features of the compressor, we report on measured performance.

  10. Method of operating a centrifugal plasma arc furnace

    Science.gov (United States)

    Kujawa, S.T.; Battleson, D.M.; Rademacher, E.L. Jr.; Cashell, P.V.; Filius, K.D.; Flannery, P.A.; Whitworth, C.G.

    1998-03-24

    A centrifugal plasma arc furnace is used to vitrify contaminated soils and other waste materials. An assessment of the characteristics of the waste is performed prior to introducing the waste into the furnace. Based on the assessment, a predetermined amount of iron is added to each batch of waste. The waste is melted in an oxidizing atmosphere into a slag. The added iron is oxidized into Fe{sub 3}O{sub 4}. Time of exposure to oxygen is controlled so that the iron does not oxidize into Fe{sub 2}O{sub 3}. Slag in the furnace remains relatively non-viscous and consequently it pours out of the furnace readily. Cooled and solidified slag produced by the furnace is very resistant to groundwater leaching. The slag can be safely buried in the earth without fear of contaminating groundwater. 3 figs.

  11. Numerical Investigation of Flow in a Centrifugal Compressor

    Science.gov (United States)

    Grishin, Yu. A.; Bakulin, V. N.

    2015-09-01

    With the use of the domestic software suite of computational hydrodynamics Flow Vision based on application of the method of control volumes, numerical simulation of air composition and delivery by a centrifugal compressor employed for supercharging a piston engine has been carried out. The head-flow characteristics of the compressor, as well as the 3D fields of flow velocity and pressure distributions in the elements of the compressor flow passage, including the interblade channels of the impeller, have been obtained for various regimes. In the regimes of diminished air flow rate, surging phenomena are identified, characterized by a return flow. The application of the technique of numerical experiment will make it possible from here on to carry out design optimization of the compressor flow passage profile and thus to improve its basic characteristics — the degree of pressure increase, compressed air flow rate, and the efficiency — as well as to reduce the costs of the development and production of compressors.

  12. New phenolic compounds from Kokuto, non-centrifuged cane sugar.

    Science.gov (United States)

    Takara, Kensaku; Matsui, Daigo; Wada, Koji; Ichiba, Toshio; Chinen, Isao; Nakasone, Yoko

    2003-02-01

    Five new phenolic compounds, 4-(beta-D-glucopyranosyloxy)-3,5-dimethoxyphenyl-propanone (8), 3-[5-[(threo) 2,3-dihydro-2-(4-hydroxy-3-methoxyphenyl)-3-hydroxymethyl-7-methoxybenzofuranyl]-propanoic acid (12), 2-[4-(3-hydroxy-1-propenyl)-2,6-dimethoxyphenoxy]-3-hydroxy-3-(4-hydroxy-3,5-dimethoxyphenyl)propyl-beta-D-glucopyranoside (13), 4-[(erythro) 2,3-dihydro-3(hydroxymethyl)-5-(3-hydropropyl)-7-methoxy-2-benzofuranyl]-2,6-dimethoxyphenyl-beta-D-glucopyranoside (14), 9-O-beta-D-xylopyranoside of icariol A2 (15), and known phenolic compounds were isolated from Kokuto, non-centrifuged cane sugar (Saccharum officinarum L.). Their structures were determined by a spectral investigation.

  13. Separation of a binary mixture by sequential centrifugal partition chromatography.

    Science.gov (United States)

    Hopmann, Elisabeth; Minceva, Mirjana

    2012-03-16

    Sequential centrifugal partition chromatography (sCPC) is a novel continuous cyclic liquid-liquid chromatographic separation technology. Each cycle of the process comprises two steps, which differ by the liquid phase used as mobile phase (upper or lower phase) and its flow direction. The feed is introduced continuously in the unit and two product streams are collected alternately, in each step of the cycle. In this work, the sCPC was modeled using the stage (cell) model. The model was used to simulate a separation of a model binary mixture consisting of pyrocatechol and hydroquinone. The solutes distribution constants, system hydrodynamics and mass transfer parameters were determined experimentally and implemented in the model. Furthermore, a parameter study (variation of the feed concentration and step times) was performed by experiments and simulation. A recently developed method was used to select the operating parameters of the sCPC unit. Copyright © 2012 Elsevier B.V. All rights reserved.

  14. Operational Experience with a Cryogenic Axial-Centrifugal Compressor

    CERN Document Server

    Decker, L; Löhlein, K; Purtschert, W; Ziegler, B L; Lebrun, P; Tavian, L; Brunovsky, I; Tucek, L

    1998-01-01

    The Large Hadron Collider (LHC), presently under construction at CERN, requires large refrigeration capacity at 1.8 K. Compression of gaseous helium at cryogenic temperatures is therefore inevitable. Together with subcontractors, Linde Kryotechnik has developed a prototype machine. This unit is based on a cryogenic axial-centrifugal compressor, running on ceramic ball bearings and driven by a variable-frequency electrical motor operating at ambient temperature. Integrated in a test facility for superconducting magnets the machine has been commissioned without major problems and successfully gone through the acceptance test in autumn 1995. Subsequent steps were initiated to improve efficiency of this prototype. This paper describes operating experience gained so far and reports on measured performance prior to and after constructional modifications.

  15. Systems approach used in the Gas Centrifuge Enrichment Plant

    Energy Technology Data Exchange (ETDEWEB)

    Rooks, W.A. Jr.

    1982-01-01

    A requirement exists for effective and efficient transfer of technical knowledge from the design engineering team to the production work force. Performance-Based Training (PBT) is a systematic approach to the design, development, and implementation of technical training. This approach has been successfully used by the US Armed Forces, industry, and other organizations. The advantages of the PBT approach are: cost-effectiveness (lowest life-cycle training cost), learning effectiveness, reduced implementation time, and ease of administration. The PBT process comprises five distinctive and rigorous phases: Analysis of Job Performance, Design of Instructional Strategy, Development of Training Materials and Instructional Media, Validation of Materials and Media, and Implementation of the Instructional Program. Examples from the Gas Centrifuge Enrichment Plant (GCEP) are used to illustrate the application of PBT.

  16. Numerical study of a high-speed miniature centrifugal compressor

    Science.gov (United States)

    Li, Xiaoyi

    A miniature centrifugal compressor is a key component of reverse Brayton cycle cryogenic cooling system. The system is commonly used to generate a low cryogenic temperature environment for electronics to increase their efficiency, or generate, store and transport cryogenic liquids, such as liquid hydrogen and oxygen, where space limit is also an issue. Because of space limitation, the compressor is composed of a radial IGV, a radial impeller and an axial-direction diffuser (which reduces the radial size because of smaller diameter). As a result of reduction in size, rotating speed of the impeller is as high as 313,000 rpm, and Helium is used as the working fluid, in order to obtain the required static pressure ratio/rise. Two main characteristics of the compressor---miniature and high-speed, make it distinct from conventional compressors. Higher compressor efficiency is required to obtain a higher COP (coefficient of performance) system. Even though miniature centrifugal compressors start to draw researchers' attention in recent years, understanding of the performance and loss mechanism is still lacking. Since current experimental techniques are not advanced enough to capture details of flow at miniature scale, numerical methods dominate miniature turbomachinery study. This work numerically studied a high speed miniature centrifugal compressor with commercial CFD code. The overall performance of the compressor was predicted with consideration of interaction between blade rows by using sliding mesh model. The law of similarity of turbomachinery was validated for small scale machines. It was found that the specific ratio effect needs to be considered when similarity law is applied. But Reynolds number effect can be neglected. The loss mechanism of each component was analyzed. Loss due to turning bend was significant in each component. Tip leakage loss of small scale turbomachines has more impact on the impeller performance than that of large scale ones. Because the

  17. Thirty Stage Annular Centrifugal Contactor Thermal Profile Measurements

    Energy Technology Data Exchange (ETDEWEB)

    David H. Meikrantz; Troy G. Garn; Jack D. Law

    2010-02-01

    A thirty stage 5 cm annular centrifugal contactor cascade has been assembled and tested to obtain thermal profiles during both ambient and heated input conditions of operation. Thermocouples were installed on every stage as well as feed inputs and Real-time data was taken during experiments lasting from two to eight hours at total flow rates of 0.5 to 1.4 liters per minute. Ambient temperature profile results show that only a small amount of heat is generated by the mechanical energy of the contactors. Steady state temperature profiles mimic the ambient temperature of the lab but are higher toward the middle of the cascade. Heated inlet solutions gave temperature profiles with smaller temperature gradients, more driven by the temperature of the inlet solutions than ambient lab temperature. Temperature effects of solution mixing, even at rotor speeds of 4000 rpm, were not measurable.

  18. Effect of Bearing Housings on Centrifugal Pump Rotor Dynamics

    Science.gov (United States)

    Yashchenko, A. S.; Rudenko, A. A.; Simonovskiy, V. I.; Kozlov, O. M.

    2017-08-01

    The article deals with the effect of a bearing housing on rotor dynamics of a barrel casing centrifugal boiler feed pump rotor. The calculation of the rotor model including the bearing housing has been performed by the method of initial parameters. The calculation of a rotor solid model including the bearing housing has been performed by the finite element method. Results of both calculations highlight the need to add bearing housings into dynamic analyses of the pump rotor. The calculation performed by modern software packages is more a time-taking process, at the same time it is a preferred one due to a graphic editor that is employed for creating a numerical model. When it is necessary to view many variants of design parameters, programs for beam modeling should be used.

  19. Cavitation Bubble Dynamics in Ammoniacal Fluids Transferred by Centrifugal Pumps

    Directory of Open Access Journals (Sweden)

    Jorge Reyes-Cruz

    2016-10-01

    Full Text Available An experiment with water and ammoniacal liquor at 27% and 34% concentrations of ammonia was carried out in order to determine the pressure dynamics during the formation of bubbles and their movement when causing cavitations in centrifugal pumps. The dynamics of bubbles was calculated numerically by applying the Rayleigh-Plesset equation using the bubble radius and the bubble build-up time. It is concluded that the pressure to form the bubbles at 22 ºC is 10,135.103 Pa for water and 45,468.103 Pa for the ammoniacal liquor at a concentration of 34 %. The radius of the bubbles found in ammoniacal liquor is in the range of 30 to 120 times the original bubble radius while the bubbles formed in water are only in the range of 15 times the original radius value.

  20. Shunted Piezoelectric Vibration Damping Analysis Including Centrifugal Loading Effects

    Science.gov (United States)

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

    2011-01-01

    Excessive vibration of turbomachinery blades causes high cycle fatigue problems which require damping treatments to mitigate vibration levels. One method is the use of piezoelectric materials as passive or active dampers. Based on the technical challenges and requirements learned from previous turbomachinery rotor blades research, an effort has been made to investigate the effectiveness of a shunted piezoelectric for the turbomachinery rotor blades vibration control, specifically for a condition with centrifugal rotation. While ample research has been performed on the use of a piezoelectric material with electric circuits to attempt to control the structural vibration damping, very little study has been done regarding rotational effects. The present study attempts to fill this void. Specifically, the objectives of this study are: (a) to create and analyze finite element models for harmonic forced response vibration analysis coupled with shunted piezoelectric circuits for engine blade operational conditions, (b) to validate the experimental test approaches with numerical results and vice versa, and (c) to establish a numerical modeling capability for vibration control using shunted piezoelectric circuits under rotation. Study has focused on a resonant damping control using shunted piezoelectric patches on plate specimens. Tests and analyses were performed for both non-spinning and spinning conditions. The finite element (FE) shunted piezoelectric circuit damping simulations were performed using the ANSYS Multiphysics code for the resistive and inductive circuit piezoelectric simulations of both conditions. The FE results showed a good correlation with experimental test results. Tests and analyses of shunted piezoelectric damping control, demonstrating with plate specimens, show a great potential to reduce blade vibrations under centrifugal loading.

  1. Approach to novel design of CO2 based centrifugal compressor

    Directory of Open Access Journals (Sweden)

    Kura Tomasz

    2016-01-01

    Full Text Available Even though turbomachinery design issues have been investigated almost since the beginning of engineering, its optimization process is still important. With the development of refrigeration devices and ORC based distributed generation facilities, a need for efficient and low-energy compressors and turbines became even more demanding. Such machines working with typical fluid, like air, are well described, but there is a room regarding the fluids like CO2, vapour of organic fluids, etc. The main objective of present studies is to propose a numerical model of the centrifugal compressor, with CO2 as the working fluid. Such unit may be a part of refrigeration cycle. Commonly, the scroll or piston compressors are used in such cases, however some discussed disadvantages show that the novel designs should be looked for. Properly designed centrifugal compressors can have higher efficiency than the presently used. Three dimensional analyses of proposed geometries were conducted – using a model including heat, mass and momentum conservation laws as well as ideal gas law. Verification of the proposed mesh and results was performed in the basis of values obtained using theoretical and empirical equations. With about 700 000 control volumes in the validated model, error of the results was no higher than 5%, with only about 1% in regards to the thermal parameters. Two design proposals were analysed, with performance maps as the main comparison factor. Apart from performance characteristics, the pressure and velocity fields were presented, showing the process of flow structure optimization. The main goal was to reduce negative effects of pressure and velocity gradients on the performance. Proposed precursory design might be a good starting point for further development of compressors. The results of numerical analysis were promising and shows the possibility of proposed design usage in practical applications, however to obtain deep understanding of the

  2. Progress of High Efficiency Centrifugal Compressor Simulations Using TURBO

    Science.gov (United States)

    Kulkarni, Sameer; Beach, Timothy A.

    2017-01-01

    Three-dimensional, time-accurate, and phase-lagged computational fluid dynamics (CFD) simulations of the High Efficiency Centrifugal Compressor (HECC) stage were generated using the TURBO solver. Changes to the TURBO Parallel Version 4 source code were made in order to properly model the no-slip boundary condition along the spinning hub region for centrifugal impellers. A startup procedure was developed to generate a converged flow field in TURBO. This procedure initialized computations on a coarsened mesh generated by the Turbomachinery Gridding System (TGS) and relied on a method of systematically increasing wheel speed and backpressure. Baseline design-speed TURBO results generally overpredicted total pressure ratio, adiabatic efficiency, and the choking flow rate of the HECC stage as compared with the design-intent CFD results of Code Leo. Including diffuser fillet geometry in the TURBO computation resulted in a 0.6 percent reduction in the choking flow rate and led to a better match with design-intent CFD. Diffuser fillets reduced annulus cross-sectional area but also reduced corner separation, and thus blockage, in the diffuser passage. It was found that the TURBO computations are somewhat insensitive to inlet total pressure changing from the TURBO default inlet pressure of 14.7 pounds per square inch (101.35 kilopascals) down to 11.0 pounds per square inch (75.83 kilopascals), the inlet pressure of the component test. Off-design tip clearance was modeled in TURBO in two computations: one in which the blade tip geometry was trimmed by 12 mils (0.3048 millimeters), and another in which the hub flow path was moved to reflect a 12-mil axial shift in the impeller hub, creating a step at the hub. The one-dimensional results of these two computations indicate non-negligible differences between the two modeling approaches.

  3. Methodology for optimally sized centrifugal partition chromatography columns.

    Science.gov (United States)

    Chollet, Sébastien; Marchal, Luc; Jérémy Meucci; Renault, Jean-Hugues; Legrand, Jack; Foucault, Alain

    2015-04-03

    Centrifugal Partition Chromatography (CPC) is a separation process based on the partitioning of solutes between two partially miscible liquid phases. There is no solid support for the stationary phase. The centrifugal acceleration is responsible for both stationary phase retention and mobile phase dispersion. CPC is thus a process based on liquid-liquid mass transfer. The separation efficiency is mainly influenced by the hydrodynamics of the phases in each cell of the column. Thanks to a visualization system, called "Visual CPC", it was observed that the mobile phase can flow through the stationary phase as a sheet, or a spray. Hydrodynamics, which directly governs the instrument efficiency, is directly affected during scale changes, and non-linear phenomena prevent the successful achievement of mastered geometrical scale changes. In this work, a methodology for CPC column sizing is proposed, based on the characterization of the efficiency of advanced cell shapes, taking into account the hydrodynamics. Knowledge about relationship between stationary phase volume, cell efficiency and separation resolution in CPC allowed calculating the optimum cell number for laboratory and industrial scale CPC application. The methodology is highlighted with results on five different geometries from 25 to 5000 mL, for two applications: the separation of alkylbenzene by partitioning with heptane/methanol/water biphasic system; and the separation of peptides by partitioning with n-butanol/acetic acid/water (4/1/5) biphasic system. With this approach, it is possible to predict the optimal CPC column length leading to highest productivity. Copyright © 2015 Elsevier B.V. All rights reserved.

  4. A Review of Centrifugal Testing of Gasoline Contamination and Remediation

    Directory of Open Access Journals (Sweden)

    Jay N. Meegoda

    2011-08-01

    Full Text Available Leaking underground storage tanks (USTs containing gasoline represent a significant public health hazard. Virtually undetectable to the UST owner, gasoline leaks can contaminate groundwater supplies. In order to develop remediation plans one must know the extent of gasoline contamination. Centrifugal simulations showed that in silty and sandy soils gasoline moved due to the physical process of advection and was retained as a pool of free products above the water table. However, in clayey soils there was a limited leak with lateral spreading and without pooling of free products above the water table. Amount leaked depends on both the type of soil underneath the USTs and the amount of corrosion. The soil vapor extraction (SVE technology seems to be an effective method to remove contaminants from above the water table in contaminated sites. In-situ air sparging (IAS is a groundwater remediation technology for contamination below the water table, which involves the injection of air under pressure into a well installed into the saturated zone. However, current state of the art is not adequate to develop a design guide for site implementation. New information is being currently generated by both centrifugal tests as well as theoretical models to develop a design guide for IAS. The petroleum contaminated soils excavated from leaking UST sites can be used for construction of highway pavements, specifically as sub-base material or blended and used as hot or cold mix asphalt concrete. Cost analysis shows that 5% petroleum contaminated soils is included in hot or cold mix asphalt concrete can save US$5.00 production cost per ton of asphalt produced.

  5. Rigorous buoyancy driven bubble mixing for centrifugal microfluidics.

    Science.gov (United States)

    Burger, S; Schulz, M; von Stetten, F; Zengerle, R; Paust, N

    2016-01-21

    We present batch-mode mixing for centrifugal microfluidics operated at fixed rotational frequency. Gas is generated by the disk integrated decomposition of hydrogen peroxide (H2O2) to liquid water (H2O) and gaseous oxygen (O2) and inserted into a mixing chamber. There, bubbles are formed that ascent through the liquid in the artificial gravity field and lead to drag flow. Additionaly, strong buoyancy causes deformation and rupture of the gas bubbles and induces strong mixing flows in the liquids. Buoyancy driven bubble mixing is quantitatively compared to shake mode mixing, mixing by reciprocation and vortex mixing. To determine mixing efficiencies in a meaningful way, the different mixers are employed for mixing of a lysis reagent and human whole blood. Subsequently, DNA is extracted from the lysate and the amount of DNA recovered is taken as a measure for mixing efficiency. Relative to standard vortex mixing, DNA extraction based on buoyancy driven bubble mixing resulted in yields of 92 ± 8% (100 s mixing time) and 100 ± 8% (600 s) at 130g centrifugal acceleration. Shake mode mixing yields 96 ± 11% and is thus equal to buoyancy driven bubble mixing. An advantage of buoyancy driven bubble mixing is that it can be operated at fixed rotational frequency, however. The additional costs of implementing buoyancy driven bubble mixing are low since both the activation liquid and the catalyst are very low cost and no external means are required in the processing device. Furthermore, buoyancy driven bubble mixing can easily be integrated in a monolithic manner and is compatible to scalable manufacturing technologies such as injection moulding or thermoforming. We consider buoyancy driven bubble mixing an excellent alternative to shake mode mixing, in particular if the processing device is not capable of providing fast changes of rotational frequency or if the low average rotational frequency is challenging for the other integrated fluidic operations.

  6. 40 CFR 63.5810 - What are my options for meeting the standards for open molding and centrifugal casting operations...

    Science.gov (United States)

    2010-07-01

    ... standards for open molding and centrifugal casting operations at new and existing sources? 63.5810 Section... § 63.5810 What are my options for meeting the standards for open molding and centrifugal casting... (d) of this section to meet the standards for open molding or centrifugal casting operations in Table...

  7. A Laboratory Experiment to Demonstrate the Principles of Sedimentation in a Centrifuge: Estimation of Radius and Settling Velocity of Bacteria

    Science.gov (United States)

    Riley, Erin; Felse, P. Arthur

    2017-01-01

    Centrifugation is a major unit operation in chemical and biotechnology industries. Here we present a simple, hands-on laboratory experiment to teach the basic principles of centrifugation and to explore the shear effects of centrifugation using bacterial cells as model particles. This experiment provides training in the use of a bench-top…

  8. Aproximación neuro-fuzzy para identificación de señales viales mediante tecnología infrarroja

    Directory of Open Access Journals (Sweden)

    G.N. Marichal

    2007-04-01

    Full Text Available Resumen: En este artículo se presenta un sistema basado en tecnología infrarroja para la clasificación de marcas viales empleando un sistema Neuro-Fuzzy como herramienta de clasificación. El sistema se ha testeado a partir de los datos suministrados cuando se ha instalado un prototipo en un robot móvil. Los resultados obtenidos son explicados en este artículo, haciendo hincapié en el diseño de nuevas reglas y la mejoría lograda mediante los métodos propuestos. Palabras clave: Control Inteligente, Robótica, Navegación de robots, Sistemas Neuro-Fuzzy

  9. Sorption of PAHs to humic acid- and iron(III)carbon ate particles by using passive dosing vials for investigating the transport of organic contamination in stormwater runoff

    DEFF Research Database (Denmark)

    Nielsen, Katrine; Mikkelsen, Peter Steen; Baun, Anders

    2013-01-01

    During the last decades, the growing urbanisation a nd increasing anthropogenic activities in urban areas have turned urban stormwater runoff int o a surface water quality contamination problem. The concerns of urban stormwater runoff as a source of contamination in the receiving surface water......) has been foun d to facilitate transport of organic contaminants and metals in stormwater runoff system s, but little is known about the role of the colloidal fraction including nano-sized particl es (0.001-1 μm). Based on the large specific surface area of colloids and nanosized particles, t heir...... for their ability to sorb polycyclic aromatic hydrocarbons (PAH’s) in an aqueous solution. These particles were used as indicators for stormwater particles which a re diverse in size and composition. For controlling the sorption onto the particles, passiv e doing vials were used (Birch et. al., 2010). Using passive...

  10. Identification of pathogenic microorganisms directly from positive blood vials by matrix-assisted laser desorption/ionization time of flight mass spectrometry

    DEFF Research Database (Denmark)

    Nonnemann, Bettina; Tvede, Michael; Bjarnsholt, Thomas

    2013-01-01

    blood vials spiked with fungi were examined. Using the cut-off score of 1.8, 81% Gram-negative bacteria were identified to the species level compared to 84% using a cut-off score of 1.5. For Gram-positive bacteria 44% were identified to the species level with a cut-off of 1.8 compared to 55...... degree of Gram positives. Using 1.5 as cut-off score increased the diagnosis for both Gram-positives and -negatives bacteria.......% with the value of 1.5. The overall identification rate was 63% (cut-off 1.5) and 54% (cut-off 1.8). Seventy-seven per cent of fungal species were identified with both log scores. MALDI-TOF MS was in this study found to be a powerful tool in fast diagnosis of Gram-negative bacteria and fungi and to a lesser...

  11. Artificial Leaks in Container Closure Integrity Testing: Nonlinear Finite Element Simulation of Aperture Size Originated by a Copper Wire Sandwiched between the Stopper and the Glass Vial.

    Science.gov (United States)

    Nieto, Alejandra; Roehl, Holger; Brown, Helen; Adler, Michael; Chalus, Pascal; Mahler, Hanns-Christian

    2016-01-01

    Container closure integrity (CCI) testing is required by different regulatory authorities in order to provide assurance of tightness of the container closure system against possible contamination, for example, by microorganisms. Microbial ingress CCI testing is performed by incubation of the container closure system with microorganisms under specified testing conditions. Physical CCI uses surrogate endpoints, such as coloration by dye solution ingress or gas flow (helium leakage testing). In order to correlate microbial CCI and physical CCI test methods and to evaluate the methods' capability to detect a given leak, artificial leaks are being introduced into the container closure system in a variety of different ways. In our study, artificial leaks were generated using inserted copper wires between the glass vial opening and rubber stopper. However, the insertion of copper wires introduces leaks of unknown size and shape. With nonlinear finite element simulations, the aperture size between the rubber stopper and the glass vial was calculated, depending on wire diameter and capping force. The dependency of the aperture size on the copper wire diameter was quadratic. With the data obtained, we were able to calculate the leak size and model leak shape. Our results suggest that the size as well as the shape of the artificial leaks should be taken into account when evaluating critical leak sizes, as flow rate does not, independently, correlate to hole size. Capping force also affected leak size. An increase in the capping force from 30 to 70 N resulted in a reduction of the aperture (leak size) by approximately 50% for all wire diameters. From 30 to 50 N, the reduction was approximately 33%. Container closure integrity (CCI) testing is required by different regulatory authorities in order to provide assurance of tightness of the container closure system against contamination, for example, by microorganisms. Microbial ingress CCI testing is performed by incubation of the

  12. Streamlined sample cleanup using combined dispersive solid-phase extraction and in-vial filtration for analysis of pesticides and environmental pollutants in shrimp

    Energy Technology Data Exchange (ETDEWEB)

    Han, Lijun [College of Science, China Agricultural University, Beijing (China); Sapozhnikova, Yelena [U.S. Dept. of Agriculture, Agricultural Research Service, Eastern Regional Research Center, 600 East Mermaid Lane, Wyndmoor, PA 19038 (United States); Lehotay, Steven J., E-mail: Steven.Lehotay@ars.usda.gov [U.S. Dept. of Agriculture, Agricultural Research Service, Eastern Regional Research Center, 600 East Mermaid Lane, Wyndmoor, PA 19038 (United States)

    2014-05-01

    Highlights: • The first report that combines in-vial filtration and dispersive-SPE for sample cleanup. • The unique application of ammonium formate for salting-out partitioning in QuEChERS. • Evaluations of a new zirconium-based and a non-friable GCB sorbent for d-SPE cleanup. • A new analytical method for 59 pesticides and environmental pollutants in shrimp. Abstract: A new method of sample preparation was developed and is reported for the first time. The approach combines in-vial filtration with dispersive solid-phase extraction (d-SPE) in a fast and convenient cleanup of QuEChERS (quick, easy, cheap, effective, rugged, and safe) extracts. The method was applied to simultaneous analysis of 42 diverse pesticides and 17 environmental contaminants, including polycyclic aromatic hydrocarbons, polychlorinated biphenyls (PCBs), and flame retardants, in shrimp as the sample matrix. Final extracts were analyzed by both low-pressure gas chromatography – triple quadrupole tandem mass spectrometry (LPGC-MS/MS), and high-performance liquid chromatography – triple quadrupole tandem mass spectrometry (HPLC-MS/MS) to provide a wide scope of analysis for targeted analytes. During method development, several different commercial sorbents for d-SPE were investigated and compared with respect to analyte recoveries. The method was validated at 10, 50, and 100 ng g⁻¹ spiking levels (10-fold lower for PCBs), and the results for nearly all analytes were between 70 and 115% recoveries with ≤17% relative standard deviations. The method was shown to be simple, fast, and effective for multi-application analysis of chemical residues in the representative food and environmental marker matrix.

  13. Stability of tranexamic acid in 0.9% sodium chloride, stored in type 1 glass vials and ethylene/propylene copolymer plastic containers.

    Science.gov (United States)

    McCluskey, Susan V; Sztajnkrycer, Matthew D; Jenkins, Donald A; Zietlow, Scott P; Berns, Kathleen S; Park, Myung S

    2014-01-01

    Tranexamic acid has recently been demonstrated to decrease all-cause mortality and deaths due to hemorrhage in trauma patients. The optimal administration of tranexamic acid is within one hour of injury, but not more than three hours from the time of injury. To aid with timely administration, a premixed solution of 1 gram tranexamic acid and 0.9% sodium chloride was proposed to be stocked as a medication in both the aeromedical transport helicopters and Emergency Department at Mayo Clinic Hospital--Rochester Saint Marys Campus. Since no published stability data exists for tranexamic acid diluted with 0.9% sodium chloride, this study was undertaken to determine the stability of tranexamic acid diluted with 0.9% sodium chloride while being stored in two types of containers. Stability was determined through the use of a stability-indicating high-performance liquid reverse phase chromatography assay, pH, and visual tests. Tranexamic acid solutions of 1 gram in 0.9% sodium chloride 65 mL were studied at predetermined intervals for 90 days in ethylene/propylene copolymer plastic containers, protected from light, and at both controlled room and refrigerated temperatures. Tranexamic acid solutions of 1 gram in 0.9% sodium chloride 50 mL were studied at predetermined intervals for 180 days in clear Type 1 borosilicate glass vials sealed with intact elastomeric, Flourotec-coated stoppers, stored protected from light at controlled room temperature. Solutions stored in the ethylene/propylene copolymer plastic containers at both storage temperatures maintained at least 98% of initial potency throughout the 90-day study period. Solutions stored in glass vials at controlled room temperature maintained at least 92% of initial potency throughout the 180-day study period. Visual and pH tests revealed stable, clear, colorless, and particulate-free solutions throughout the respective study periods.

  14. Diseño de un plan estratégico de seguridad vial departamental (Modelo piloto para el departamento de Boyacá

    Directory of Open Access Journals (Sweden)

    Flor Ángela Cerquera Escobar Julio Andrés Pabón Cachope Ricardo Andrés Fajardo

    2010-11-01

    Full Text Available Sintetiza  una  serie  de  consideraciones  que  sirvencomo marco  de  referencia  para  definir  un  plan  deacción en seguridad vial, cuyo desarrollo y ejecuciónestán  encaminados  a  reducir  los  accidentes  en  lasvías del departamento de Boyacá, y que sirve comomodelo guía para cualquier otra región del país. Losresultados  que  se  presentan  fueron  obtenidos  en  eldesarrollo  del  proyecto  de  grado  en  Ingeniería  deTransporte  y  Vías  t itulado  “Diseño  del  PlanEstratégico de Seguridad Vial para el departamentode Boyacá”;  además,  se  consideran  varios  tópicosplanteados en documentos que sobre Seguridad Vialha  desarrollado  el  Grupo  de  Invest igación  yDesarrollo en Operación del Tránsito, GIDOT. Esteproyecto  se  adelantó  como  un  direccionamiento  alPlan  de  Desarrollo  del  departamento,   en  lo

  15. Efficient centrifugal recovery of Bacillus thuringiensis biopesticides from fermented wastewater and wastewater sludge.

    Science.gov (United States)

    Brar, Satinder K; Verma, M; Tyagi, R D; Valéro, J R; Surampalli, R Y

    2006-03-01

    Studies were conducted on harvesting of Bacillus thuringiensis (Bt)-based biopesticides from fermented broths of starch industry wastewater (SIW), wastewater sludge (raw and hydrolyzed-NH and TH, respectively) and semi-synthetic soyameal to enhance entomotoxicity (Tx) by centrifugation. Pertinent factors influencing Tx, solids concentration, pH, temperature and centrifugal force were investigated. The centrifugate solids concentration beyond 100 g/l did not enhance Tx, instead caused pellet formation. Centrifugation efficiency (Tx recovery) was higher at pH 4, and temperature 20 degrees C for starch wastewater (98%), wastewater sludge (98% and 97.8% for non-hydrolyzed and hydrolyzed, respectively) and soya broth (83%). For maximum Tx recovery (SIW-95%; NH-90%; TH-98% and soya-78%), the centrifugal force and time required was 48,000 g and 30 min, respectively. Losses in recovery efficiency were lower for SIW and wastewater sludge in comparison to soya on adopting commercially recommended centrifugal force of 9000 g. The settling velocity computations for different fermented broths enabled calculation of Sigma factor for continuous commercial centrifuge of a given capacity and hence simulation of power requirements. It was established that power requirements for a given Tx recovery efficiency were highest for conventional medium (soya) in comparison to other waste-based fermented broths.

  16. Numerical studies in a centrifugal pump with the improved blade considering cavitation

    Science.gov (United States)

    Song, P. F.; Zhang, Y. X.; Xu, C.; Zhou, X.; Zhang, J. Y.

    2015-01-01

    In this paper, a centrifugal pump with the improved blade for cavitation is studied numerically. A 3D impeller with logarithmic spiral blade profile was designed by the in-house hydraulic design code using a centrifugal pump geometric parameters, and the blade profile curve of suction side on the designed impeller is replaced by a combination of tangent line and circle arc line. The cavitation flows in the centrifugal pump with designed impeller, modified impeller and centrifugal pump spectrum impeller are respectively calculated by two-phase CFD simulation at three flow rates. The tests of the centrifugal pump have been conducted to verify numerical simulation. The effects of designed impeller and modified impeller on hydraulic efficiency, critical cavitation number, cavitation length, head drop performance and vapor cavity distribution in impeller are investigated. The results show that the modification of blade profile curve of suction side can improve the cavitation performance of an impeller and hydraulic efficiency of centrifugal pump. Compared with designed impeller, the critical cavitation number of centrifugal pump with modified impeller decrease by 26.5% under the same flow rate coefficient, and the cavitation intensity in the modified impeller is weakened effectively. The hydraulic efficiency of modified impeller also increases by 4.9%.

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

    Science.gov (United States)

    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.

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

    Directory of Open Access Journals (Sweden)

    Zhenzhou Zhu

    2016-11-01

    Full Text Available 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.

  19. Centrifuge-dewatered mature fine tails : geotechnical observations from a field test

    Energy Technology Data Exchange (ETDEWEB)

    Lahaie, R. [Syncrude Canada Ltd., Fort McMurray, AB (Canada); Seto, J.T.C. [BGC Engineering, Edmonton, AB (Canada)

    2010-07-01

    This paper discussed the field scale test of a centrifuge-dewatering method for treating mature fine tailings (MFT). The method is intended to reduce MFT stockpiles and create a trafficable surface. In centrifuge-dewatering, the MFT is diluted, flocculated, and processed through a centrifuge plant. The resulting cake is taken to a tailings deposit. In the oil sands industry, centrifuges have not yet been used to dewater fluid tailings on a commercial scale. A 6-week trial was undertaken to better comprehend the process of centrifuging MFT and evaluate ways of reclaiming centrifuge-dewatered MFT. Centrifuge cake was produced and deposited in 5 partly contained cells and 2 large culverts, and the deposits were instrumented, sampled, and tested over the course of a year. Centrifugation initially caused the solids content of the MFT to increase from 30 percent to more than 50 percent, and the exposed cell deposits subsequently densified and strengthened as a result of natural desiccation, such as freeze-thaw and evaporative drying. Less than a year after deposition, the resulting solids content exceeded 70 percent, and the undrained shear strength exceeded 15 kilopascals. The cake in the 2 culverts was found to consolidate and strengthen more slowly. A ground-based laser scanning technique was used to survey the deposits in order to measure changes over time. The centrifuge-dewatering process was found to be viable, but in order to meet regulatory mandates, supplementary methods will be needed to further increase the strength gain. 2 refs., 3 tabs., 11 figs.

  20. Proyectos de espacio público: Reciclaje de espacio público mediante la optimización de la sección vial en las calles de Bogotá

    Directory of Open Access Journals (Sweden)

    Álvaro Rodríguez-Valencia

    2009-07-01

    Full Text Available Debido a las dinámicas dispersas de crecimiento urbano y a la forma seccionada en la que se desarrollaron las calles en Bogotá, muchas zonas de la ciudad presentan actualmente sobre oferta de la red vial de acceso y colectoras, donde grandes superficies pavimentadas sirven a unos pocos usuarios. Estas extensas superficies que son utilizadas exclusivamente por los usuarios de unas pocas construcciones, representan grandes sobrecostos para la ciudad en términos de mantenimiento vial. En contraposición, muchas de estas, así como la zona en la que se ubican, presentan deficiencias en materia de otras formas de espacio público, tales como andenes o zonas verdes. Para evitar esta situación se hace necesario un tratamiento más dinámico e integral de la red vial, basado en una relación directa entre volumen de tráfico y la sección vial, resultante de modelaciones zonales de tráfico.

  1. Analytical procedure for the in-vial derivatization-extraction of phenolic acids and flavonoids in methanolic and aqueous plant extracts followed by gas chromatography with mass selective detection.

    NARCIS (Netherlands)

    Fiamegos, Y.C.; Nanos, C.G.; Vervoort, J.J.M.; Stalikas, C.D.

    2004-01-01

    An in-vial simple method for the combined derivatization and extraction of phenolic acids and flavonoids from plant extracts and their direct determination with GC-MS, is described. The method is taking advantage of the beneficial potentials of phase transfer catalysis (PTC). Catalysts in soluble

  2. Culture.:'Culture.'

    OpenAIRE

    Thin, Neil; Biswas-Diener, Robert

    2016-01-01

    Although the most visible elements of culture are dress, cuisine and architecture, culture is a highly psychological phenomenon. Culture is a pattern of meaning for understanding how the world works. This knowledge is shared among a group of people and passed from one generation to the next. This module defines culture, addresses methodological issues, and introduces the idea that culture is a process. Understanding cultural processes can help people get along better with others and be more s...

  3. Oil-free centrifugal hydrogen compression technology demonstration

    Energy Technology Data Exchange (ETDEWEB)

    Heshmat, Hooshang [Mohawk Innovative Technology Inc., Albany, NY (United States)

    2014-05-31

    One of the key elements in realizing a mature market for hydrogen vehicles is the deployment of a safe and efficient hydrogen production and delivery infrastructure on a scale that can compete economically with current fuels. The challenge, however, is that hydrogen, being the lightest and smallest of gases with a lower viscosity and density than natural gas, readily migrates through small spaces and is difficult to compresses efficiently. While efficient and cost effective compression technology is crucial to effective pipeline delivery of hydrogen, the compression methods used currently rely on oil lubricated positive displacement (PD) machines. PD compression technology is very costly, has poor reliability and durability, especially for components subjected to wear (e.g., valves, rider bands and piston rings) and contaminates hydrogen with lubricating fluid. Even so called “oil-free” machines use oil lubricants that migrate into and contaminate the gas path. Due to the poor reliability of PD compressors, current hydrogen producers often install duplicate units in order to maintain on-line times of 98-99%. Such machine redundancy adds substantially to system capital costs. As such, DOE deemed that low capital cost, reliable, efficient and oil-free advanced compressor technologies are needed. MiTi’s solution is a completely oil-free, multi-stage, high-speed, centrifugal compressor designed for flow capacity of 500,000 kg/day with a discharge pressure of 1200 psig. The design employs oil-free compliant foil bearings and seals to allow for very high operating speeds, totally contamination free operation, long life and reliability. This design meets the DOE’s performance targets and achieves an extremely aggressive, specific power metric of 0.48 kW-hr/kg and provides significant improvements in reliability/durability, energy efficiency, sealing and freedom from contamination. The multi-stage compressor system concept has been validated through full scale

  4. Reversible thermo-pneumatic valves on centrifugal microfluidic platforms.

    Science.gov (United States)

    Aeinehvand, Mohammad Mahdi; Ibrahim, Fatimah; Harun, Sulaiman Wadi; Kazemzadeh, Amin; Rothan, Hussin A; Yusof, Rohana; Madou, Marc

    2015-08-21

    Centrifugal microfluidic systems utilize a conventional spindle motor to automate parallel biochemical assays on a single microfluidic disk. The integration of complex, sequential microfluidic procedures on these platforms relies on robust valving techniques that allow for the precise control and manipulation of fluid flow. The ability of valves to consistently return to their former conditions after each actuation plays a significant role in the real-time manipulation of fluidic operations. In this paper, we introduce an active valving technique that operates based on the deflection of a latex film with the potential for real-time flow manipulation in a wide range of operational spinning speeds. The reversible thermo-pneumatic valve (RTPV) seals or reopens an inlet when a trapped air volume is heated or cooled, respectively. The RTPV is a gas-impermeable valve composed of an air chamber enclosed by a latex membrane and a specially designed liquid transition chamber that enables the efficient usage of the applied thermal energy. Inputting thermo-pneumatic (TP) energy into the air chamber deflects the membrane into the liquid transition chamber against an inlet, sealing it and thus preventing fluid flow. From this point, a centrifugal pressure higher than the induced TP pressure in the air chamber reopens the fluid pathway. The behaviour of this newly introduced reversible valving system on a microfluidic disk is studied experimentally and theoretically over a range of rotational frequencies from 700 RPM to 2500 RPM. Furthermore, adding a physical component (e.g., a hemispherical rubber element) to induce initial flow resistance shifts the operational range of rotational frequencies of the RTPV to more than 6000 RPM. An analytical solution for the cooling of a heated RTPV on a spinning disk is also presented, which highlights the need for the future development of time-programmable RTPVs. Moreover, the reversibility and gas impermeability of the RTPV in the

  5. Composite Fibers from Recycled Plastics Using Melt Centrifugal Spinning.

    Science.gov (United States)

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

    2017-09-06

    New methods are being developed to enable the production of value-added materials from high-volume, low-cost feedstocks arising from domestic recycling streams. In this work, recycled bottle-grade polyethylene terephthalate, polystyrene, and polypropylene were spun into fibers from the melt using a centrifugal spinning technique. Mono-component fibers and 50/50 blends of each polymer and a 33/33/33 blend of all three polymers were evaluated. Fiber morphology, chemistry, thermal, and mechanical properties were probed. Fiber diameters ranged from ca. 1 to over 12 µm, with polypropylene fibers having the smallest fiber diameters. Mono-component fibers were generally defect-free, while composite fibers containing polypropylene were beady. Fibers made from polyethylene terephthalate had the highest tensile strength, and the addition of polyethylene terephthalate to the other polymers improved the mechanical properties of the blends. Nano- and micro-fibers from both pure and mixed waste streams are expected to have applications in myriad areas such as ultra/micro-filtration, composites, and insulation.

  6. Centrifugal compressor shape modification using a proposed inverse design method

    Energy Technology Data Exchange (ETDEWEB)

    Niliahmadabadi, Mahdi [Isfahan University of Technology, Isfahan (Iran, Islamic Republic of); Poursadegh, Farzad [Sharif University of Technology, Tehran (Iran, Islamic Republic of)

    2013-03-15

    This paper is concerned with a quasi-3D design method for the radial and axial diffusers of a centrifugal compressor on the meridional plane. The method integrates a novel inverse design algorithm, called ball-spine algorithm (BSA), and a quasi-3D analysis code. The Euler equation is solved on the meridional plane for a numerical domain, of which unknown boundaries (hub and shroud) are iteratively modified under the BSA until a prescribed pressure distribution is reached. In BSA, unknown walls are composed of a set of virtual balls that move freely along specified directions called spines. The difference between target and current pressure distributions causes the flexible boundary to deform at each modification step. In validating the quasi-3D analysis code, a full 3D Navier-Stokes code is used to analyze the existing and designed compressors numerically. Comparison of the quasi-3D analysis results with full 3D analysis results shows viable agreement. The 3D numerical analysis of the current compressor shows a huge total pressure loss on the 90 .deg. bend between the radial and axial diffusers. Geometric modification of the meridional plane causes the efficiency to improve by about 10%.

  7. Small centrifugal pumps for low-thrust rocket engines

    Science.gov (United States)

    Furst, R. B.

    1986-01-01

    Six small, low specific speed centrifugal pump configurations were designed, fabricated, and tested. The configurations included shrouded, and 25 and 100% admission open face impellers with 2 inch tip diameters; 25, 50, and 100% emission vaned diffusers; and volutes with conical exits. Impeller tip widths varied from 0.030 inch to 0.052 inch. Design specific speeds (N sub s = RPM*GPM**0.5.FT**0.75) were 430 (four configurations) and 215 (two configurations). The six configurations were tested with water as the pumped fluid. Noncavitating performance results are presented for the design speed of 24,500 rpm over a flowrate range from 1 to 6 gpm for the N sub s = 430 configurations and test speeds up to 29,000 rpm over a flowrate range from 0.3 to 1.2 gpm for the N sub s = 215 configurations. Cavitating performance results are presented over a flowrate range from 60 to 120% of design flow. Fabrication of the small pump conponents is also discussed.

  8. Compressive yield stress of depletion gels from stationary centrifugation profiles

    Science.gov (United States)

    Lattuada, Enrico; Buzzaccaro, Stefano; Piazza, Roberto

    2018-01-01

    We have investigated the stationary sedimentation profiles of colloidal gels obtained by an arrested phase-separation process driven by depletion forces, which have been compressed either by natural gravity or by a centrifugal acceleration ranging between 6g and 2300g. Our measurements show that the gel rheological properties display a drastic change when the gel particle volume fraction exceeds a value φc , which barely depends on the strength of the interparticle attractive forces that consolidate the network. In particular, the gel compressive yield stress \\Pi(φ) , which increases as \\Pi(φ) ∼ φ4.2 for φ ≲ φc , displays a diverging behaviour for φ>φc , with an asymptotic value that is close to the random close packing value for hard spheres. The evidence we obtained suggests that φc basically coincides with the liquid (colloid-rich) branch of the metastable coexistence curve, rather than with the lower (and ϕ-dependent) values expected for an attractive glass line penetrating inside the coexistence region.

  9. Design concepts for the Centrifuge Facility Life Sciences Glovebox

    Science.gov (United States)

    Sun, Sidney C.; Horkachuck, Michael J.; Mckeown, Kellie A.

    1989-01-01

    The Life Sciences Glovebox will provide the bioisolated environment to support on-orbit operations involving non-human live specimens and samples for human life sceinces experiments. It will be part of the Centrifuge Facility, in which animal and plant specimens are housed in bioisolated Habitat modules and transported to the Glovebox as part of the experiment protocols supported by the crew. At the Glovebox, up to two crew members and two habitat modules must be accommodated to provide flexibility and support optimal operations. This paper will present several innovative design concepts that attempt to satisfy the basic Glovebox requirements. These concepts were evaluated for ergonomics and ease of operations using computer modeling and full-scale mockups. The more promising ideas were presented to scientists and astronauts for their evaluation. Their comments, and the results from other evaluations are presented. Based on the evaluations, the authors recommend designs and features that will help optimize crew performance and facilitate science accommodations, and specify problem areas that require further study.

  10. Central centrifugal cicatricial alopecia amalgamated with alopecia areata: immunologic findings

    Directory of Open Access Journals (Sweden)

    Ana Maria Abreu Velez

    2014-07-01

    Full Text Available Introduction: Both scarring and non-scarring alopecias exist; however, rare cases demonstrate features of both classes. Case Report: We describe an interesting alopecia case with amalgamated clinical, histologic and immunopathologic features of scarring and non-scarring alopecia. Specifically, the case displays combined features of alopecia areata (AA and of central centrifugal cicatricial alopecia (CCCA. A 36 year old female presented with symmetric, round, patchy hair loss on her scalp. Methods: Biopsies for hematoxylin and eosin (H&E examination, as well as for special stains, direct immunofluorescence (DIF and immunohistochemistry (IHC were performed. Results: The H&E biopsy revealed focally diminished hair follicular units, and sebaceous gland damage. Perifollicular concentric fibrosis was confirmed by Verhoeff elastin special staining. Antibodies to micelles were noted. Positive IHC staining for CD4, CD8, CD45 and multiple proteases and protease inhibitors was noted around selected follicular unit remnants. Conclusion: We present a rare alopecia, combining histologic features of CCCA with additional, selected immunologic features of AA.

  11. Solanidine isolation from Solanum tuberosum by centrifugal partition chromatography.

    Science.gov (United States)

    Attoumbré, Jacques; Giordanengo, Philippe; Baltora-Rosset, Sylvie

    2013-07-01

    The aim of this investigation was the preparative isolation of solanidine (aglycone of the two main potato glycoalkaloids: α-chaconine and α-solanine) from fresh Solanum tuberosum (cv. Pompadour) material by implementing a new preparation scheme using centrifugal partition chromatography (CPC). A setup for obtaining solanidine by hydrolysis of the glycoalkaloids found in the skin and sprouts of S. tuberosum was first developed. Then its isolation was carried out by the development of CPC conditions: the solvent system used for separation was ethyl acetate/butanol/water in the ratio 42.5:7.5:50 v/v/v, 0.6 g of crude extract were separated with a 8 mL/min flow rate of mobile phase while rotating at 2500 rpm. A run yielded 98 mg of solanidine (86.7% recovery from the crude extract) in a one-step separation. The purity of the isolated solanidine was over 98%. Thus, CPC has proven to be the method of choice to get solanidine of very high purity from S. tuberosum biomass in large quantities. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  12. Centrifugal Filtration System for Severe Accident Source Term Treatment

    Energy Technology Data Exchange (ETDEWEB)

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

    2016-05-15

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

  13. A test program to measure fluid mechanical whirl-excitation forces in centrifugal pumps

    Science.gov (United States)

    Brennen, C. E.; Acosta, A. J.; Caughey, T. K.

    1980-01-01

    The details of a test program for the measurement of the unsteady forces on centrifugal impellers are discussed. Various hydrodynamic flows are identified as possible contributors to these destabilizing forces.

  14. Rapid, low-cost prototyping of centrifugal microfluidic devices for effective implementation of various microfluidic operations

    CSIR Research Space (South Africa)

    Hugo, S

    2013-10-01

    Full Text Available particularly attractive solution for implementing microfluidic operations, as pumps, valves and other fluidic operations can be achieved primarily using centrifugal forces, with only a small motor required to power the system. Numerous devices can...

  15. Analysis and improvement of calculation procedure of high-speed centrifugal pumps

    Science.gov (United States)

    Kraeva, E. M.; Masich, I. S.

    2017-10-01

    The model of flow around a flowing part of a high-speed centrifugal pump with a semi-open impeller is presented. The calculated ratios for design of lowflow pumps are obtained and confirmed experimentally.

  16. Intelligent Diagnosis Method for Centrifugal Pump System Using Vibration Signal and Support Vector Machine

    National Research Council Canada - National Science Library

    Xue, Hongtao; Li, Zhongxing; Wang, Huaqing; Chen, Peng

    2014-01-01

    ...), possibility theory, and Dempster-Shafer theory (DST) on the basis of the vibration signals, to diagnose frequent faults in the centrifugal pump at an early stage, such as cavitation, impeller unbalance, and shaft misalignment...

  17. Flow behaviour and robustness of non-segregating tailings made from filtered/centrifuged MFT

    Energy Technology Data Exchange (ETDEWEB)

    Nik, R.M.; Sego, D.C.; Morgenstern, N.R. [Alberta Univ., Edmonton, AB (Canada). Geotechnical Center

    2010-07-01

    This PowerPoint presentation described an experimental study of a centrifugal dewatering filtration process for mature fine tailings (MFT). Various MFT samples from different oil sands operations were pumped into a filtering centrifuge that produced cake, thin tailings, and filtrate. The MFT was then transformed into non-segregated tailings (NST) and composite tailings (CT). The depositional characteristics of the CT-NST samples were evaluated in a series of flume tests. Flow profiles were presented for various samples. Vane shear tests were also conducted. The yield stress of each sample was compared with its flow duration and solids content. The results of the experimental tests demonstrated that the centrifugal filtration process can be considered as the initial stage of a multi-stage tailings management plan. The filtering centrifuge method can be used to produce robust CTs with higher solids content. Use of the method can decrease the amount of coagulants or flocculants required for further treatment. tabs., figs.

  18. Whirling disease Myxosoma cerebralis spore concentration using the continuous plankton centrifuge.

    Science.gov (United States)

    O'Grodnick, J J

    1975-01-01

    A method for concentrating and detecting the spores of the cause of whirling disease (Myxosoma cerebralis) of salmonids is described. The method involves homogenization of head skeletons, screening out tissue shreds, and concentrating with a continuous plankton centrifuge.

  19. Sedimentation equilibria of ferrofluids: I. Analytical centrifugation in ultrathin glass capillaries

    NARCIS (Netherlands)

    Luigjes, B.|info:eu-repo/dai/nl/31412330X; Thies-Weesie, D.M.E.|info:eu-repo/dai/nl/138690200; Philipse, A.P.|info:eu-repo/dai/nl/073532894; Erné, B.H.|info:eu-repo/dai/nl/141937378

    2012-01-01

    Analytical centrifugation is used for the first time to measure sedimentation equilibrium concentration profiles of a ferrofluid, a concentrated colloidal dispersion of strongly absorbing magnetic nanoparticles. To keep the optical absorbance from becoming too strong, the optical path length is

  20. Influence of the positive prewhirl on the performance of centrifugal pumps with different airfoils

    Science.gov (United States)

    Zhou, C. M.; Wang, H. M.; Huang, X.; Lin, H.

    2012-11-01

    According to the basic theory of turbomachinery design and inlet guide vanes prewhirl regulation, two different airfoils inlet guide vanes of prewhirl regulation device were designed, the influence of the positive prewhirl to the performance of centrifugal pump were studied based on different airfoils. The results show that, for a single-suction centrifugal pump: Gottingen bowed blade-type inlet guide vane adjustment effect is better than straight blade-type inlet guide; appropriate design of positive prewhirl can elevate the efficiency of centrifugal pumps. Compared with no vane conditions, the efficiency of centrifugal pump with prewhirl vanes has been greatly improved and the power consumption has been reduced significantly, while has little influence on the head.

  1. Interrogation of fibre Bragg gratings through a fibre optic rotary joint on a geotechnical centrifuge

    Science.gov (United States)

    Correia, Ricardo; James, Stephen W.; Marshall, Alec; Heron, Charles; Korposh, Sergiy

    2016-05-01

    The monitoring of an array of fibre Bragg gratings (FBGs) strain sensors was performed through a single channel, single mode fibre optic rotary joint (FORJ) mounted on a geotechnical centrifuge. The array of three FBGs was attached to an aluminum plate that was anchored at the ends and placed on the model platform of the centrifuge. Acceleration forces of up to 50g were applied and the reflection signal of the monitored FBGs recorded dynamically using a 2.5kHz FBG interrogator placed outside the centrifuge. The use of a FORJ allowed the monitoring of the FBGs without submitting the FBG interrogator to the high g-forces experienced in the centrifuge.

  2. Retention of Ascorbic Acid and Solid Concentration via Centrifugal Freeze Concentration of Orange Juice

    Directory of Open Access Journals (Sweden)

    P. Orellana-Palma

    2017-01-01

    Full Text Available Freeze concentration of liquid foods produces high-quality concentrates while retaining the heat-labile compounds found in fresh samples. Centrifugal freeze concentration is a cryoconcentration method assisted by an external force, centrifugation, to enhance the separation of concentrate from the ice. When applying centrifugal freeze concentration to orange juice, after the third cryoconcentration cycle, the ascorbic acid content in the concentrate showed retention close to 70% of the initial value. After the third cycle, the solutes in the concentrate increased 4 times the initial value of the fresh sample with 70% efficiency. The color evaluation showed that the final concentrated fraction was darker than the fresh juice. The centrifugal freeze concentration in orange juice was effective for obtaining a high-quality concentrate with a higher concentration of solids and ascorbic acid retention.

  3. Diagnosing herpesvirus infections by real time amplification and rapid culture.

    NARCIS (Netherlands)

    J. Guldemeester; A.D.M.E. Osterhaus (Albert); H.G.M. Niesters (Bert); G.J.J. van Doornum (Gerard)

    2003-01-01

    textabstractProcedures using real-time technique were developed to demonstrate the presence of herpes simplex virus type 1 (HSV-1) and HSV-2, varicella zoster virus (VZV), and cytomegalovirus (CMV) in miscellaneous clinical specimens. The assays were compared to rapid culture using centrifugation

  4. A Method to Determine the Slip Factor of Centrifugal Pumps through Experiment

    Science.gov (United States)

    Zhang, Yu-Liang; Zhu, Zu-Chao; Dou, Hua-Shu; Cui, Bao-Ling; Li, Yi; Xiao, Jun-Jian

    2015-04-01

    In this paper, a method to determine the slip factor of centrifugal impellers is proposed based on the experimental result of the external performance of centrifugal pumps. This proposed method is superior to the conventional experimental method, which needs not to measure the flow parameters at impeller outlet. The results show that the present method can be used to obtain the slip factor at offdesign condition in a wide range of flow rate besides at the design point.

  5. Centrifugal Modelling of Soil Structures. Part III. The Stability of River Banks and Flood Embankments.

    Science.gov (United States)

    1978-10-01

    backup in centrifuge model preparation. Mr. C. Collison and Mr. S. Boniface who built, service and run the Cambridge centrifuge, for an excellent working...respects from the procedure described above. The first test, 2DF1 01SLACEINNT PORE WAfIm TRANSAUCERS PRESURE II no I [0 0 PANS LOODAN MODELO ~OP~A...diaphragm strain gauge on the back. The transducers were very small and gave excellent results in the water line to the reservoir. In the soil, however

  6. Guided imagery, anxiety, heart rate, and heart rate variability during centrifuge training.

    Science.gov (United States)

    Jing, Xiaolu; Wu, Ping; Liu, Fang; Wu, Bin; Miao, Danmin

    2011-02-01

    Centrifuge training is an important method of improving the hypergravity tolerance of pilots, cosmonauts, and Chinese astronauts. However, the concomitants of tension or anxiety often impede training. Guided imagery (GI), a mind-body relaxation technique, provides a behavioral and cognitive means whereby individuals are able to exert control over the focus of attention. This study aims to investigate the immediate effects of GI for reducing stress in centrifuge training. There were 12 healthy young men who were randomly assigned to a GI group or music group. We measured changes in heart rate during centrifuge training, in heart rate variability before and after centrifuge training, and also evaluated relaxation and anxiety in three phases: before intervention, after intervention, and following centrifuge training. The change in the pattern of anxiety was different in the two groups over the three phases. Anxiety (measured by State Anxiety Inventory) in the GI group changed from 31.7 +/- 5.9 to 26.8 +/- 2.6 and 27.8 +/- 4.1, whereas for the music group this changed from 32.2 +/- 7.6 to 31.2 +/- 8.3 and 26.8 +/- 6.8. During centrifuge training, the maximal HR for the GI group (101.2 +/- 8.8) was lower than that of the music group (123.0 +/- 19.1). In addition GI showed a decrease in low frequency (LF, 0.04-0.15 Hz) components and an increase in high frequency (HF, 0.15-0.4 Hz) components before and after centrifuge training. GI was capable of decreasing tension, anxiety, and sympathetic nervous system activity pre- or post-centrifugation.

  7. Influence of Prewhirl Regulation by Inlet Guide Vanes on Cavitation Performance of a Centrifugal Pump

    OpenAIRE

    Lei Tan; Baoshan Zhu; Shuliang Cao; Yuchuan Wang; Binbin Wang

    2014-01-01

    The influence of prewhirl regulation by inlet guide vanes (IGVs) on a centrifugal pump performance is investigated experimentally and numerically. The experimental results show that IGVs can obviously change the head and increase the efficiency of the tested centrifugal pump over a wide range of flow rates. Although the cavitation performance is degraded, the variation of the cavitation critical point is less than 0.5 m. Movement of the computed three-dimensional streamlines in suction pipe a...

  8. Effect of density gradient centrifugation on reactive oxygen species in human semen.

    Science.gov (United States)

    Takeshima, Teppei; Yumura, Yasushi; Kuroda, Shinnosuke; Kawahara, Takashi; Uemura, Hiroji; Iwasaki, Akira

    2017-06-01

    Density gradient centrifugation can separate motile sperm from immotile sperm and other cells for assisted reproduction, but may also remove antioxidants from seminal plasma, resulting in oxidative stress. Therefore, we investigated reactive oxygen species (ROS) concentrations and distribution in semen before and after density gradient centrifugation. We assessed semen volume, sperm concentration, sperm motility, and ROS levels before and after density gradient centrifugation (300 x g for 20 minutes) in 143 semen samples from 118 patients. The ROS removal rate was evaluated in ROS-positive samples and ROS formation rate in ROS-negative samples. Thirty-eight of 143 untreated samples (26.6%) were ROS-positive; sperm motility was significantly lower in these samples than in ROS-negative samples (p density gradient centrifugation, only seven of the 38 ROS-positive samples (18.42%) exhibited a ROS-positive lower layer (containing motile sperm) with a ROS removal rate of 81.58%, whereas the upper layer was ROS-positive in 24 samples (63.16%). In the ROS-negative group (n = 105), ROS was detected in 19 samples after centrifugation (18.10%, ROS generation rate), of which 18 were ROS-positive only in the upper layer or interface and the other was ROS-positive in both layers. Density gradient centrifugation can separate motile sperm from immotile sperm as well as remove ROS (including newly generated ROS). This data supports the view that density gradient centrifugation can select motile spermatozoa without enhancing oxidative stress. ROS: reactive oxygen species; SOD: superoxide dismutase; GPx: glutathione peroxidase; DNA: deoxyribonucleic acid; DGC: density gradient centrifugation; IUI: intrauterine insemination; IVF: in vitro fertilization; HEPES: 4-(2-hydroxyethyl)-1-piperazineethanesulfonic acid; EDTA: ethylenediaminetetraacetic acid; HTF: HEPES-buffered human tubal fluid; IMSI: intracytoplasmic morphologically selected sperm injection; SMAS: sperm motility analyzing

  9. Modeling on Fluid Flow and Inclusion Motion in Centrifugal Continuous Casting Strands

    Science.gov (United States)

    Wang, Qiangqiang; Zhang, Lifeng; Sridhar, Seetharaman

    2016-08-01

    During the centrifugal continuous casting process, unreasonable casting parameters can cause violent level fluctuation, serious gas entrainment, and formation of frozen shell pieces at the meniscus. Thus, in the current study, a three-dimensional multiphase turbulent model was established to study the transport phenomena during centrifugal continuous casting process. The effects of nozzle position, casting and rotational speed on the flow pattern, centrifugal force acting on the molten steel, level fluctuation, gas entrainment, shear stress on mold wall, and motion of inclusions during centrifugal continuous casting process were investigated. Volume of Fluid model was used to simulate the molten steel-air two-phase. The level fluctuation and the gas entrainment during casting were calculated by user-developed subroutines. The trajectory of inclusions in the rotating system was calculated using the Lagrangian approach. The results show that during centrifugal continuous casting, a large amount of gas was entrained into the molten steel, and broken into bubbles of various sizes. The greater the distance to the mold wall, the smaller the centrifugal force. Rotation speed had the most important influence on the centrifugal force distribution at the side region. Angular moving angle of the nozzle with 8° and keeping the rotation speed with 60 revolutions per minute can somehow stabilize the level fluctuation. The increase of angular angle of nozzle from 8 to 18 deg and rotation speed from 40 to 80 revolutions per minute favored to decrease the total volume of entrained bubbles, while the increase of distance of nozzle moving left and casting speed had reverse effects. The trajectories of inclusions in the mold were irregular, and then rotated along the strand length. After penetrating a certain distance, the inclusions gradually moved to the center of billet and gathered there. More work, such as the heat transfer, the solidification, and the inclusions entrapment

  10. Numerical identification of blade exit angle effect on the performance for a multistage centrifugal pump impeller

    OpenAIRE

    Babayigit Osman; Kocaaslan Osman; Aksoy Muharrem Hilmi; Guleren Kursad Melih; Ozgoren Muammer

    2015-01-01

    Nowadays, single and multistage centrifugal pumps are widely used in industrial and mining enterprises. One of the most important components of a centrifugal pump is the impeller. The performance characteristics are related to the pump comprising the head and the overall efficiency rely a great deal on the impeller geometry. In this work, effects of blade exit angle change on hydraulic efficiency of a multi stage pump impeller are investigated via Ansys-Fluent computational fluid dynamics sof...

  11. Experimental Study on Series Operation of Sliding Vane Pump and Centrifugal Pump

    OpenAIRE

    Tao Li; Weiming Zhang; Ming Jiang; Zhengyang Li

    2013-01-01

    A platform for sliding vane pump and centrifugal pump tests is installed to study the series operation of them under different characteristics of pipeline. Firstly, the sliding vane pump and the centrifugal pump work independently, and the performance is recorded. Then, the two types of pumps are combined together, with the sliding vane pump acting as the feeding pump. Comparison is made between the performance of the independently working pump and the performance of series operation pump. Re...

  12. The Effect of Moment of Inertia on the Liquids in Centrifugal Microfluidics

    Directory of Open Access Journals (Sweden)

    Esmail Pishbin

    2016-12-01

    Full Text Available The flow of liquids in centrifugal microfluidics is unidirectional and dominated by centrifugal and Coriolis forces (i.e., effective only at T-junctions. Developing mechanisms and discovering efficient techniques to propel liquids in any direction other than the direction of the centrifugal force has been the subject of a large number of studies. The capillary force attained by specific surface treatments, pneumatic energy, active and passive flow reciprocation and Euler force have been previously introduced in order to manipulate the liquid flow and push it against the centrifugal force. Here, as a new method, the moment of inertia of the liquid inside a chamber in a centrifugal microfluidic platform is employed to manipulate the flow and propel the liquid passively towards the disc center. Furthermore, the effect of the moment of inertia on the liquid in a rectangular chamber is evaluated, both in theory and experiments, and the optimum geometry is defined. As an application of the introduced method, the moment of inertia of the liquid is used in order to mix two different dyed deionized (DI waters; the mixing efficiency is evaluated and compared to similar mixing techniques. The results show the potential of the presented method for pumping liquids radially inward with relatively high flow rates (up to 23 mm3/s and also efficient mixing in centrifugal microfluidic platforms.

  13. Performance and internal flow condition of mini centrifugal pump with splitter blades

    Science.gov (United States)

    Shigemitsu, T.; Fukutomi, J.; Kaji, K.; Wada, T.

    2012-11-01

    Mini centrifugal pumps having a diameter smaller than 100mm are employed in many fields. But the design method for the mini centrifugal pump is not established because the internal flow condition for these small-sized fluid machines is not clarified and conventional theory is not suitable for small-sized pumps. Therefore, mini centrifugal pumps with simple structure were investigated by this research. Splitter blades were adopted in this research to improve the performance and the internal flow condition of mini centrifugal pump which had large blade outlet angle. The original impeller without the splitter blades and the impeller with the splitter blades were prepared for an experiment. The performance tests are conducted with these rotors in order to investigate the effect of the splitter blades on performance and internal flow condition of mini centrifugal pump. On the other hand, a three dimensional steady numerical flow analysis is conducted with the commercial code (ANSYS-CFX) to investigate the internal flow condition in detail. It is clarified from the experimental results that the performance of the mini centrifugal pump is improved by the effect of the splitter blades. The blade-to-blade low velocity regions are suppressed in the case with the splitter blades and the total pressure loss regions are decreased. The effects of the splitter blades on the performance and the internal flow condition are discussed in this paper.

  14. Research on energy conversion mechanism of a screw centrifugal pump under the water

    Science.gov (United States)

    Quan, H.; Li, R. N.; Su, Q. M.; Han, W.; Cheng, X. R.; Shen, Z. J.

    2013-12-01

    In order to research screw centrifugal pump impeller power capability and energy conversion mechanism, we used Navier-Stokes equation and standard k-ε equation turbulence model on the basis of the Euler equations to carry out screw centrifugal pump internal flow numerical simulation. This was explored by simulating specific design conditions; the medium is water, variation of speed and pressure of flow filed under the action of the impeller, and the screw centrifugal impeller shroud line and wheel line segment take monitoring sites. The monitoring points are between dynamic head and static head change to analyze the energy conversion capability along the impeller corners of screw centrifugal pump. The results show that the energy of fluid of the screw centrifugal pump is provided by spiral segment, the spiral segment in front of the impeller has played a multi-level role, it has significant reference value to research the energy conversion mechanism of screw centrifugal pump under solid-liquid two phase.

  15. Feasibility of a Short-Arm Centrifuge for Mouse Hypergravity Experiments

    Science.gov (United States)

    Morita, Hironobu; Obata, Koji; Abe, Chikara; Shiba, Dai; Shirakawa, Masaki; Kudo, Takashi; Takahashi, Satoru

    2015-01-01

    To elucidate the pure impact of microgravity on small mammals despite uncontrolled factors that exist in the International Space Station, it is necessary to construct a 1 g environment in space. The Japan Aerospace Exploration Agency has developed a novel mouse habitat cage unit that can be installed in the Cell Biology Experiment Facility in the Kibo module of the International Space Station. The Cell Biology Experiment Facility has a short-arm centrifuge to produce artificial 1 g gravity in space for mouse experiments. However, the gravitational gradient formed inside the rearing cage is larger when the radius of gyration is shorter; this may have some impact on mice. Accordingly, biological responses to hypergravity induced by a short-arm centrifuge were examined and compared with those induced by a long-arm centrifuge. Hypergravity induced a significant Fos expression in the central nervous system, a suppression of body mass growth, an acute and transient reduction in food intake, and impaired vestibulomotor coordination. There was no difference in these responses between mice raised in a short-arm centrifuge and those in a long-arm centrifuge. These results demonstrate the feasibility of using a short-arm centrifuge for mouse experiments. PMID:26221724

  16. Physical mechanism of centrifugal-gravity wave resonant instability in azimuthally symmetric swirling flows

    Science.gov (United States)

    Yellin-Bergovoy, Ron; Heifetz, Eyal; Umurhan, Orkan M.

    2017-10-01

    We present an explicit analysis of wave-resonant instability of swirling flows inside fast rotating cylindrical containers. The linear dynamics are decomposed into the interaction between the horizontal inner centrifugal edge waves and the outer vertical gravity waves with the aim of understanding the dynamics of the centrifugal waves. We show how the far field velocity induced respectively by the centrifugal and the gravity waves affect each other's propagation rates and amplitude growth. We follow this with an analysis of the instability in terms of a four-wave interaction, two centrifugal and two gravity ones, and explain why the resonant instability can be obtained only between a pair of two counterpropagating waves, one centrifugal and one gravity. Furthermore, a near resonant regime which does not yield instability is shown to result from a phase-locking configuration between a pair of a counterpropagating centrifugal wave and a propropagating gravity one, where the interaction affects the waves' propagation rates but not the amplitude growth.

  17. New methods and media for the centrifugation of honey bee (Hymenoptera: Apidae) drone semen.

    Science.gov (United States)

    Wegener, Jakob; May, Tanja; Kamp, Günter; Bienefeld, Kaspar

    2014-02-01

    Centrifugation of Apis mellifera L. drone semen is a necessary step in the homogenization of semen pools for the enlargement of the effective breeding population, as well as in the collection of semen by the so-called washing technique. It is also of interest for the removal of cryoprotectants after cryopreservation. The adoption of methods involving semen centrifugation has been hampered by their damaging effect to sperm. Here, we tested four new diluents as well as three additives (catalase, hen egg yolk, and a protease inhibitor), using sperm motility and dual fluorescent staining as indicators of semen quality. Three of the new diluents significantly reduced motility losses after centrifugation, as compared with the literature standard. Values of motility and propidium iodide negativity obtained with two of these diluents were not different from those measured with untreated semen. The least damaging diluent, a citrate-HEPES buffer containing trehalose, was then tested in an insemination experiment with centrifuged semen. Most queens receiving this semen produced normal brood, and the number of sperm reaching the storage organ of the queen was not significantly different from that in queens receiving untreated semen. These results could improve the acceptance of techniques involving the centrifugation of drone semen. The diluent used in the insemination experiment could also serve as semen extender for applications not involving centrifugation.

  18. Polymethylmethacrylate/Polyacrylonitrile Membranes via Centrifugal Spinning as Separator in Li-Ion Batteries

    Directory of Open Access Journals (Sweden)

    Meltem Yanilmaz

    2015-04-01

    Full Text Available Electrospun nanofiber membranes have been extensively studied as separators in Li-ion batteries due to their large porosity, unique pore structure, and high electrolyte uptake. However, the electrospinning process has some serious drawbacks, such as low spinning rate and high production cost. The centrifugal spinning technique can be used as a fast, cost-effective and safe technique to fabricate high-performance fiber-based separators. In this work, polymethylmethacrylate (PMMA/polyacrylonitrile (PAN membranes with different blend ratios were produced via centrifugal spinning and characterized by using different electrochemical techniques for use as separators in Li-ion batteries. Compared with commercial microporous polyolefin membrane, centrifugally-spun PMMA/PAN membranes had larger ionic conductivity, higher electrochemical oxidation limit, and lower interfacial resistance with lithium. Centrifugally-spun PMMA/PAN membrane separators were assembled into Li/LiFePO4 cells and these cells delivered high capacities and exhibited good cycling performance at room temperature. In addition, cells using centrifugally-spun PMMA/PAN membrane separators showed superior C-rate performance compared to those using microporous polypropylene (PP membranes. It is, therefore, demonstrated that centrifugally-spun PMMA/PAN membranes are promising separator candidate for high-performance Li-ion batteries.

  19. Feasibility of a Short-Arm Centrifuge for Mouse Hypergravity Experiments.

    Directory of Open Access Journals (Sweden)

    Hironobu Morita

    Full Text Available To elucidate the pure impact of microgravity on small mammals despite uncontrolled factors that exist in the International Space Station, it is necessary to construct a 1 g environment in space. The Japan Aerospace Exploration Agency has developed a novel mouse habitat cage unit that can be installed in the Cell Biology Experiment Facility in the Kibo module of the International Space Station. The Cell Biology Experiment Facility has a short-arm centrifuge to produce artificial 1 g gravity in space for mouse experiments. However, the gravitational gradient formed inside the rearing cage is larger when the radius of gyration is shorter; this may have some impact on mice. Accordingly, biological responses to hypergravity induced by a short-arm centrifuge were examined and compared with those induced by a long-arm centrifuge. Hypergravity induced a significant Fos expression in the central nervous system, a suppression of body mass growth, an acute and transient reduction in food intake, and impaired vestibulomotor coordination. There was no difference in these responses between mice raised in a short-arm centrifuge and those in a long-arm centrifuge. These results demonstrate the feasibility of using a short-arm centrifuge for mouse experiments.

  20. Analogue scale modelling of extensional tectonic processes using a large state-of-the-art centrifuge

    Science.gov (United States)

    Park, Heon-Joon; Lee, Changyeol

    2017-04-01

    Analogue scale modelling of extensional tectonic processes such as rifting and basin opening has been numerously conducted. Among the controlling factors, gravitational acceleration (g) on the scale models was regarded as a constant (Earth's gravity) in the most of the analogue model studies, and only a few model studies considered larger gravitational acceleration by using a centrifuge (an apparatus generating large centrifugal force by rotating the model at a high speed). Although analogue models using a centrifuge allow large scale-down and accelerated deformation that is derived by density differences such as salt diapir, the possible model size is mostly limited up to 10 cm. A state-of-the-art centrifuge installed at the KOCED Geotechnical Centrifuge Testing Center, Korea Advanced Institute of Science and Technology (KAIST) allows a large surface area of the scale-models up to 70 by 70 cm under the maximum capacity of 240 g-tons. Using the centrifuge, we will conduct analogue scale modelling of the extensional tectonic processes such as opening of the back-arc basin. Acknowledgement This research was supported by Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Education (grant number 2014R1A6A3A04056405).

  1. Human ES cells: starting culture from frozen cells.

    Science.gov (United States)

    Trish, Erin; Dimos, John; Eggan, Kevin

    2006-11-09

    Here we demonstrate how our lab begins a HuES human embryonic stem cell line culture from a frozen stock. First, a one to two day old ten cm plate of approximately one (to two) million irradiated mouse embryonic fibroblast feeder cells is rinsed with HuES media to remove residual serum and cell debris, and then HuES media added and left to equilibrate in the cell culture incubator. A frozen vial of cells from long term liquid nitrogen storage or a -80 C freezer is sourced and quickly submerged in a 37 C water bath for quick thawing. Cells in freezing media are then removed from the vial and placed in a large volume of HuES media. The large volume of HuES media facilitates removal of excess serum and DMSO, which can cause HuES human embryonic stem cells to differentiate. Cells are gently spun out of suspension, and then re-suspended in a small volume of fresh HuES media that is then used to seed the MEF plate. It is considered important to seed the MEF plate by gently adding the HuES cells in a drop wise fashion to evenly disperse them throughout the plate. The newly established HuES culture plate is returned to the incubator for 48 hrs before media is replaced, then is fed every 24 hours thereafter.

  2. Solid-state chemiluminescence assay for ultrasensitive detection of antimony using on-vial immobilization of CdSe quantum dots combined with liquid–liquid–liquid microextraction

    Energy Technology Data Exchange (ETDEWEB)

    Costas-Mora, Isabel; Romero, Vanesa; Lavilla, Isela; Bendicho, Carlos, E-mail: bendicho@uvigo.es

    2013-07-25

    Graphical abstract: -- Highlights: •Solid-state chemiluminescence based on CdSe QDs was developed. •QDs immobilization in a vial was achieved in a simple and fast way. •Antimony detection was achieved by inhibition of the CdSe QDs/H{sub 2}O{sub 2} CL reaction. •LLLME allowed improving the selectivity and sensitivity of the CL assay. •The capping ligand played a critical role in the selectivity of the CL system. -- Abstract: On-vial immobilized CdSe quantum dots (QDs) are applied for the first time as chemiluminescent probes for the detection of trace metal ions. Among 17 metal ions tested, inhibition of the chemiluminescence when CdSe QDs are oxidized by H{sub 2}O{sub 2} was observed for Sb, Se and Cu. Liquid–liquid–liquid microextraction was implemented in order to improve the selectivity and sensitivity of the chemiluminescent assay. Factors influencing both the CdSe QDs/H{sub 2}O{sub 2} chemiluminescent system and microextraction process were optimized for ultrasensitive detection of Sb(III) and total Sb. In order to investigate the mechanism by which Sb ions inhibit the chemiluminescence of the CdSe QDs/H{sub 2}O{sub 2} system, atomic force microscopy (AFM), X-ray photoelectron spectroscopy (XPS), UV–vis absorption and fluorescence measurements were performed. The selection of the appropriate CdSe QDs capping ligand was found to be a critical issue. Immobilization of QDs caused the chemiluminescence signal to be enhanced by a factor of 100 as compared to experiments carried out with QDs dispersed in the bulk aqueous phase. Under optimized conditions, the detection limit was 6 ng L{sup −1} Sb and the repeatability expressed as relative standard deviation (N = 7) was about 1.3%. An enrichment factor of 95 was achieved within only 3 min of microextraction. Several water samples including drinking, spring, and river waters were analyzed. The proposed method was validated against CRM NWTM-27.2 fortified lake water, and a recovery study was

  3. Defining the needs for gas centrifuge enrichment plants advanced safeguards

    Energy Technology Data Exchange (ETDEWEB)

    Boyer, Brian David [Los Alamos National Laboratory; Erpenbeck, Heather H [Los Alamos National Laboratory; Miller, Karen A [Los Alamos National Laboratory; Swinhoe, Martyn T [Los Alamos National Laboratory; Ianakiev, Kiril [Los Alamos National Laboratory; Marlow, Johnna B [Los Alamos National Laboratory

    2010-04-05

    Current safeguards approaches used by the International Atomic Energy Agency (IAEA) at gas centrifuge enrichment plants (GCEPs) need enhancement in order to verify declared low-enriched (LEU) production, detect undeclared LEU production and detect highly enriched uranium (HEU) production with adequate detection probability using nondestructive assay (NDA) techniques. At present inspectors use attended systems, systems needing the presence of an inspector for operation, during inspections to verify the mass and {sup 235}U enrichment of declared UF{sub 6} containers used in the process of enrichment at GCEPs. In verifying declared LEU production, the inspectors also take samples for off-site destructive assay (DA) which provide accurate data, with 0.1% to 0.5% measurement uncertainty, on the enrichment of the UF{sub 6} feed, tails, and product. However, taking samples of UF{sub 6} for off-site analysis is a much more labor and resource intensive exercise for the operator and inspector. Furthermore, the operator must ship the samples off-site to the IAEA laboratory which delays the timeliness of results and interruptions to the continuity of knowledge (CofK) of the samples during their storage and transit. This paper contains an analysis of possible improvements in unattended and attended NDA systems such as process monitoring and possible on-site analysis of DA samples that could reduce the uncertainty of the inspector's measurements and provide more effective and efficient IAEA GCEPs safeguards. We also introduce examples advanced safeguards systems that could be assembled for unattended operation.

  4. A Centrifugal Contactor Design to Facilitate Remote Replacement

    Energy Technology Data Exchange (ETDEWEB)

    David H. Meikrantz; Jack. D. Law; Troy G. Garn; Lawrence L. Macaluso

    2011-03-01

    Advanced designs of nuclear fuel recycling and radioactive waste treatment plants are expected to include more ambitious goals for solvent extraction based separations including; higher separations efficiency, high-level waste minimization, and a greater focus on continuous processes to minimize cost and footprint. Therefore, Annular Centrifugal Contactors (ACCs) are destined to play a more important role for such future processing schemes. This work continues the development of remote designs for ACCs that can process the large throughputs needed for future nuclear fuel recycling and radioactive waste treatment plants. A three stage, 12.5 cm diameter rotor module has been constructed and is being evaluated for use in highly radioactive environments. This prototype assembly employs three standard CINC V-05 clean-in-place (CIP) units modified for remote service and replacement via new methods of connection for solution inlets, outlets, drain and CIP. Hydraulic testing and functional checks were successfully conducted and then the prototype was evaluated for remote handling and maintenance. Removal and replacement of the center position V-05R contactor in the three stage assembly was demonstrated using an overhead rail mounted PaR manipulator. Initial evaluation indicates a viable new design for interconnecting and cleaning individual stages while retaining the benefits of commercially reliable ACC equipment. Replacement of a single stage via remote manipulators and tools is estimated to take about 30 minutes, perhaps fast enough to support a contactor change without loss of process equilibrium. The design presented in this work is scalable to commercial ACC models from V-05 to V-20 with total throughput rates ranging from 20 to 650 liters per minute.

  5. Prolonged expression of MHC class I - peptide expression in bone marrow derived retrovirus transfected matured dendritic cells by continuous centrifugation in the presence of IL-4.

    Science.gov (United States)

    Hettihewa, L M

    2011-11-01

    Dendritic cells (DCs) are potent antigen presenting cells which proceed from immature to a mature stage during their differentiation. There are several methods of obtaining long lasting mature antigen expressing DCs and different methods show different levels of antigen expressions. We investigated bone marrow derived DCs for the degree of maturation and genetically engineered antigen presentation in the presence of interleukin-4 (IL-4) as a maturity enhancer. DCs and transfected retrovirus were cultured together in the presence of granulocyte-macrophage colony stimulating factor (GMCSF)-IL4, GMCSF +IL4, lipopolysaccharide (LPS). B 7.1, B7.2 and CD11c were measured by the degree of immune fluorescence using enhanced green fluorescent protein (EGFP) shuttled retrovirus transfected antigen. Degree of MHC class I molecule with antigen presentation of antigen was also evaluated by fluorescence activated cell sorting. The antigen presenting capacity of transfected DCs was investigated. Bone marrow DCs were generated in the presence of GMCSF and IL-4 in vitro. Dividing bone marrow cells were infected with EGFP shuttled retrovirus expressing SSP2 by prolonged centrifugation for three consecutive days from day 5, 6 and 7 and continued to culture in the presence of GMSCF and IL-4 until day 8. IL-4 as a cytokine increased the maturation of retrovirus transfected DCs by high expression of B 7-1 and B 7-2. Also, IL-4 induced DC enhanced by the prolonged centrifugation and it was shown by increased antigen presentation of these dendric cells as antigen presenting cell (APC). Cytolytic effects were significantly higher in cytotoxic T cell response (CTLs) mixed with transfected DCs than CTLs mixed with pulsed DCs. There was an enhanced antigen presentation by prolonged expression of antigen loaded MHC class I receptors in DCs in the presence of IL-4 by prolonged centrifugation.

  6. The Effect of Age in the Alteration in Fluid Balance of Rats in Response to Centrifugation

    Science.gov (United States)

    Fuller, Charles A.

    2000-01-01

    With an increase in gravity load induced by centrifugation or upon return to Earth following spaceflight, there is a period of adjustment in fluid balance in rats. With centrifugation there is a reduced fluid intake with maintenance of the rate of urine excretion. Following spaceflight there is an increase in urine output and maintenance of fluid intake. The initial period of acclimation to hypergravity is associated with a net loss of fluids. In the present study in response to centrifugation at 2.0 G this period of acclimation is present in mature rats for a longer period of time, about 24 hours. Following this initial response a period of over compensation has previously been reported. In the present study this was not observed. The net effect of these alterations in water intake and output in response to centrifugation for 14 days was slight increase in the percent total body water, with effective compensation seen in both young and mature rats. Older rats have been shown to have a reduced relative thirst and compensatory renal function in response to hypohydration, hyperosmolality and pharmacological stimuli. Responsiveness to these stimuli are delayed and/or attenuated in older animals. Similar findings were noted in the present study in the initial response to centrifugation. The older animal had a delayed return of fluid intake to control levels. The delay of one day did not appear to effect long-term fluid homeostasis, as there was difference in the response of percent total body water at the end of 14 days of centrifugation with both age groups having a slight but significant increase. This increase has been attributed to the increase in lean body mass induced by centrifugation.

  7. Combining ergometer exercise and artificial gravity in a compact-radius centrifuge

    Science.gov (United States)

    Diaz, Ana; Trigg, Chris; Young, Laurence R.

    2015-08-01

    Humans experience physiological deconditioning during space missions, primarily attributable to weightlessness. Some of these adverse consequences include bone loss, muscle atrophy, sensory-motor deconditioning, and cardiovascular alteration, which may lead to orthostatic intolerance when astronauts return to Earth. Artificial gravity could provide a comprehensive countermeasure capable of challenging all the physiological systems at once, particularly if combined with exercise, thereby maintaining overall health during extended exposure to weightlessness. A new Compact Radius Centrifuge (CRC) platform was designed and built on the existing Short Radius Centrifuge (SRC) at the Massachusetts Institute of Technology (MIT). The centrifuge has been constrained to a radius of 1.4 m, the upper radial limit for a centrifuge to fit within an International Space Station (ISS) module without extensive structural alterations. In addition, a cycle ergometer has been added for exercise during centrifugation. The CRC now includes sensors of foot forces, cardiovascular parameters, and leg muscle electromyography. An initial human experiment was conducted on 12 subjects to analyze the effects of different artificial gravity levels (0 g, 1 g, and 1.4 g, measured at the feet) and ergometer exercise intensities (25 W warm-up, 50 W moderate and 100 W vigorous) on the musculoskeletal function as well as motion sickness and comfort. Foot forces were measured during the centrifuge runs, and subjective comfort and motion sickness data were gathered after each session. Preliminary results indicate that ergometer exercise on a centrifuge may be effective in improving musculoskeletal function. The combination is well tolerated and motion sickness is minimal. The MIT CRC is a novel platform for future studies of exercise combined with artificial gravity. This combination may be effective as a countermeasure to space physiological deconditioning.

  8. Unsteady internal flow conditions of mini-centrifugal pump with splitter blades

    Science.gov (United States)

    Shigemitsu, T.; Fukutomi, J.; Kaji, K.; Wada, T.

    2013-02-01

    Mini centrifugal pumps having a diameter smaller than 100mm are employed in many fields. But the design method for the mini centrifugal pump is not established because the internal flow condition for these small-sized fluid machines is not clarified and conventional theory is not suitable for small-sized pumps. Therefore, mini centrifugal pumps with simple structure were investigated by this research. Splitter blades were adopted in this research to improve the performance and the internal flow condition of mini centrifugal pump which had large blade outlet angle. The original impeller without the splitter blades and the impeller with the splitter blades were prepared for experiment. The performance tests are conducted with these rotors in order to investigate the effect of the splitter blades on performance and internal flow condition of mini centrifugal pump. On the other hand, a three dimensional unsteady numerical flow analysis was conducted to investigate the change of the internal flow according to the rotor rotation. It is clarified from the experimental results that the performance of the mini centrifugal pump is improved by the splitter blades. The blade-to-blade low velocity region was suppressed in the case with the splitter blades. In addition to that, the unsteady flows near the volute casing tongue were suppressed due to the splitter blades. In the present paper, the performance of the mini centrifugal pump is shown and the unsteady flow condition is clarified with the results of the numerical flow analysis. Furthermore, the effects of the splitter blades on the performance and the unsteady internal flow condition are investigated.

  9. Potential Application of Centrifuges to Protect the CNS in Space and on Earth.

    Science.gov (United States)

    Takamatsu, Yoshiki; Ho, Gilbert; Shimizu, Yuki; Sugama, Shuei; Takenouchi, Takato; Waragai, Masaaki; Wei, Jianshe; Hashimoto, Makoto

    2017-12-29

    Centrifuges are the principal means of generating physiological hypergravity and have been used for many medical purposes, including the therapy of psychiatric diseases and evaluation of vestibular system in the pilots. In particular, modern centrifuges have evolved into mechanically sophisticated precision instruments compared to primitive ones in old times, indicating that centrifuges might possess great potential in modern medicine. Indeed, studies are in progress to apply centrifuges to musculoskeletal degenerative diseases, such as osteoporosis and sarcopenia. Given that the aging-related diseases are manifested under microgravity conditions, including astronauts and the bed-ridden elderly, it is reasonable to speculate that centrifuge-induced hypergravity may counteract the progression of these diseases. Such a view may also be important for neurodegenerative diseases for which the radical treatments are yet to be established. Therefore, the main objective of this paper is to discuss a potential therapeutic use of centrifuges for protection against the central nervous system (CNS) disorders, both in space and on Earth. Mechanistically hypergravity may exert stimulatory effects on preconditioning, chaperone expression, synapse plasticity, and growth and differentiation in the nervous system. Furthermore, hypergravity may suppress the progress of type II diabetes mellitus (T2DM), leading to inhibition of T2DM-triggered CNS disorders, including neurodegenerative diseases, ischemia and depression. Moreover, it is possible that hypergravity may counteract the neurodegeneration in hippocampus induced by the microgravity conditions and psychiatric diseases. Collectively, further investigations are warranted to demonstrate that centrifuge-induced hypergravity may be beneficial for the therapy of the CNS disorders. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

  10. Metabolomic method: UPLC-q-ToF polar and non-polar metabolites in the healthy rat cerebellum using an in-vial dual extraction.

    Directory of Open Access Journals (Sweden)

    Amera A Ebshiana

    Full Text Available Unbiased metabolomic analysis of biological samples is a powerful and increasingly commonly utilised tool, especially for the analysis of bio-fluids to identify candidate biomarkers. To date however only a small number of metabolomic studies have been applied to studying the metabolite composition of tissue samples, this is due, in part to a number of technical challenges including scarcity of material and difficulty in extracting metabolites. The aim of this study was to develop a method for maximising the biological information obtained from small tissue samples by optimising sample preparation, LC-MS analysis and metabolite identification. Here we describe an in-vial dual extraction (IVDE method, with reversed phase and hydrophilic liquid interaction chromatography (HILIC which reproducibly measured over 4,000 metabolite features from as little as 3mg of brain tissue. The aqueous phase was analysed in positive and negative modes following HILIC separation in which 2,838 metabolite features were consistently measured including amino acids, sugars and purine bases. The non-aqueous phase was also analysed in positive and negative modes following reversed phase separation gradients respectively from which 1,183 metabolite features were consistently measured representing metabolites such as phosphatidylcholines, sphingolipids and triacylglycerides. The described metabolomics method includes a database for 200 metabolites, retention time, mass and relative intensity, and presents the basal metabolite composition for brain tissue in the healthy rat cerebellum.

  11. In-Vial Micro-Matrix-Solid Phase Dispersion for the Analysis of Fragrance Allergens, Preservatives, Plasticizers, and Musks in Cosmetics

    Directory of Open Access Journals (Sweden)

    Maria Celeiro

    2014-07-01

    Full Text Available Fragrance allergens, preservatives, plasticizers, and synthetic musks are usually present in cosmetic and personal care products formulations and many of them are subjected to use restrictions or labeling requirements. Matrix solid-phase dispersion (MSPD is a very suitable analytical technique for the extraction of these compounds providing a simple, low cost sample preparation, and the possibility of performing both extraction and clean-up in one step, reducing possible contamination and analyte losses. This extraction technique has been successfully applied to many cosmetics ingredients allowing obtaining quantitative recoveries. A new very simple micro-MSPD procedure performing the disruption step in a vial is proposed for the gas chromatography-mass spectrometry (GC-MS analysis of 66 chemicals usually present in cosmetics and personal care products. The method was validated showing general recoveries between 80% and 110%, relative standard deviation (RSD values lower than 15%, and limits of detection (LODs below 30 ng·g−1. The validated method was applied to a broad range of cosmetics and personal care products, including several products intended for baby care.

  12. Chromatographic and Spectral Analysis of Two Main Extractable Compounds Present in Aqueous Extracts of Laminated Aluminum Foil Used for Protecting LDPE-Filled Drug Vials

    Directory of Open Access Journals (Sweden)

    Samuel O. Akapo

    2009-01-01

    Full Text Available Laminated aluminum foils are increasingly being used to protect drug products packaged in semipermeable containers (e.g., low-density polyethylene (LDPE from degradation and/or evaporation. The direct contact of such materials with primary packaging containers may potentially lead to adulteration of the drug product by extractable or leachable compounds present in the closure system. In this paper, we described a simple and reliable HPLC method for analysis of an aqueous extract of laminated aluminum foil overwrap used for packaging LDPE vials filled with aqueous pharmaceutical formulations. By means of combined HPLC-UV, GC/MS, LC/MS/MS, and NMR spectroscopy, the two major compounds detected in the aqueous extracts of the representative commercial overwraps were identified as cyclic oligomers with molecular weights of 452 and 472 and are possibly formed from poly-condensation of the adhesive components, namely, isophthalic acid, adipic acid, and diethylene glycol. Lower molecular weight compounds that might be associated with the “building blocks” of these compounds were not detected in the aqueous extracts.

  13. Víctimización Vial y Justicia Restaurativa: Reflexiones desde la Propia Experiencia Victimal (Road Victimization and Restorative Justice: some Reflections from the own Experience

    Directory of Open Access Journals (Sweden)

    Isabel Germán

    2014-07-01

    Full Text Available After a very brief statement of the circumstances of road victimization suffered by the author of this text, some reflections on their perceptions of restorative justice in cases of serious victimization are presented. As well, and on the basis of some victimological and criminological concepts that have previously been delimited, the author suggests some touches on issues such as direct and indirect victimization, the secondary victimization, altruistic and vicarious pain, resilience, and the facilitating role of forgiveness to re-build and re-create the victims. Tras una breve exposición de las circunstancias de victimización vial sufrida por la autora de este texto, se plasman algunas reflexiones sobre su percepción de la Justicia restaurativa en casos graves de victimación. Así, con base en conceptos victimológico-criminológicos que se van delimitando a lo largo del texto, se apuntan algunas pinceladas sobre cuestiones como la victimización directa e indirecta, la victimización secundaria, el dolor altruista y el dolor vicario, la resiliencia, y la función facilitadora del perdón para re-construir y re-crear a la víctima.

  14. Physicochemical stability of carfilzomib (Kyprolis®) containing solutions in glass vials, ready-to-administer plastic syringes and infusion bags over a 28-day storage period.

    Science.gov (United States)

    Kim, Sun Hee; Krämer, Irene

    2017-01-01

    Centralized aseptic preparation of ready-to-administer carfilzomib containing parenteral solutions in plastic syringes and polyolefine (PO) infusion bags needs profound knowledge about the physicochemical stability in order to determine the beyond-use-date of the preparations. Therefore, the purpose of this study was to determine the physicochemical stability of carfilzomib solution marketed as Kyprolis® powder for solution for infusion. Reconstituted solutions and ready-to-administer preparations of Kyprolis® stored under refrigeration (2-8℃) or at room temperature (25℃) were analyzed at predetermined intervals over a maximum storage period of 28 days. Chemical stability of carfilzomib was planned to be determined with a stability-indicating reversed-phase high-performance liquid chromatography assay. Physicochemical stability was planned to be determined by visual inspection of clarity and color as well as pH measurement. The study results show that reconstituted carfilzomib containing parenteral solutions are stable in glass vials as well as diluted solutions in plastic syringes and PO infusion bags over a period of at least 28 days when stored light protected under refrigeration. When stored at room temperature, reconstituted and diluted carfilzomib solutions are physicochemically stable over 14 days and 10 days, respectively. The physicochemical stability of carfilzomib infusion solutions allows cost-saving pharmacy-based centralized preparation of ready-to-administer preparations.

  15. Reversible gelling culture media for in-vitro cell culture in three-dimensional matrices

    Science.gov (United States)

    An, Yuehuei H.; Mironov, Vladimir A.; Gutowska, Anna

    2000-01-01

    A gelling cell culture medium useful for forming a three dimensional matrix for cell culture in vitro is prepared by copolymerizing an acrylamide derivative with a hydrophilic comonomer to form a reversible (preferably thermally reversible) gelling linear random copolymer in the form of a plurality of linear chains having a plurality of molecular weights greater than or equal to a minimum gelling molecular weight cutoff, mixing the copolymer with an aqueous solvent to form a reversible gelling solution and adding a cell culture medium to the gelling solution to form the gelling cell culture medium. Cells such as chondrocytes or hepatocytes are added to the culture medium to form a seeded culture medium, and temperature of the medium is raised to gel the seeded culture medium and form a three dimensional matrix containing the cells. After propagating the cells in the matrix, the cells may be recovered by lowering the temperature to dissolve the matrix and centrifuging.

  16. Influence of Velocity Curves Unevenness on the Centrifugal Pump Head

    Directory of Open Access Journals (Sweden)

    V. A. Cheryomushkin

    2017-01-01

    Full Text Available A formula of the theoretical head, which gives the value of the impeller in terms of its geometrical parameters, is used to calculate the pump head at the stage of theoretical design. One of the main assumptions in this case is a strip theory, which does not take into consideration the unevenness of curves of the meridional and circumferential velocity components at the impeller outlet of a centrifugal pump. The article studies this influence. Describes a mathematical model for theoretical and numerical calculations. Shows the figures of the flow part under study and of the computational grid. For complete formalization of the problem the meshing models and boundary conditions are shown. As the boundary conditions, full pump-inlet head into the flow part and velocity at the outlet were used. Then, there are the graphs to compare the results of theoretical and numerical calculation and the error is shown. For comparison, a value of the theoretical head was multiplied by the efficiency, which was defined by computer simulation. A designing process of the flow part was iterative, so the comparison was carried out for all iterations. It should be noted that correction for the finite number of blades is also assumption. To determine a degree of the errors impact because of this correction, an average value of the circumferential component of the fluid velocity at the impeller outlet was calculated by two above methods followed by their comparison. It was shown that this impact is negligible, i.e. correction provides a sufficiently accurate value. In conclusion, the paper explains the possible reasons for inaccuracies in theoretical determination of the head, as well as the option to eliminate this inaccuracy, thereby reducing the time required for defining the basic parameters of the flow part. To illustrate the nature of fluid flow, for the last iteration are given the fields of the pressure distribution and the velocity vector in the equatorial

  17. Centrifugal fans: Similarity, scaling laws, and fan performance

    Science.gov (United States)

    Sardar, Asad Mohammad

    Centrifugal fans are rotodynamic machines used for moving air continuously against moderate pressures through ventilation and air conditioning systems. There are five major topics presented in this thesis: (1) analysis of the fan scaling laws and consequences of dynamic similarity on modelling; (2) detailed flow visualization studies (in water) covering the flow path starting at the fan blade exit to the evaporator core of an actual HVAC fan scroll-diffuser module; (3) mean velocity and turbulence intensity measurements (flow field studies) at the inlet and outlet of large scale blower; (4) fan installation effects on overall fan performance and evaluation of fan testing methods; (5) two point coherence and spectral measurements conducted on an actual HVAC fan module for flow structure identification of possible aeroacoustic noise sources. A major objective of the study was to identity flow structures within the HVAC module that are responsible for noise and in particular "rumble noise" generation. Possible mechanisms for the generation of flow induced noise in the automotive HVAC fan module are also investigated. It is demonstrated that different modes of HVAC operation represent very different internal flow characteristics. This has implications on both fan HVAC airflow performance and noise characteristics. It is demonstrated from principles of complete dynamic similarity that fan scaling laws require that Reynolds, number matching is a necessary condition for developing scale model fans or fan test facilities. The physical basis for the fan scaling laws derived was established from both pure dimensional analysis and also from the fundamental equations of fluid motion. Fan performance was measured in a three times scale model (large scale blower) in air of an actual forward curved automotive HVAC blower. Different fan testing methods (based on AMCA fan test codes) were compared on the basis of static pressure measurements. Also, the flow through an actual HVAC

  18. Hypolipidemic activities of xanthorrhizol purified from centrifugal TLC.

    Science.gov (United States)

    Oon, Seok Fang; Nallappan, Meenakshii; Kassim, Nur Kartinee; Shohaimi, Shamarina; Sa'ariwijaya, Mohd Shazrul Fazry; Tee, Thiam Tsui; Cheah, Yew Hoong

    2016-09-23

    Hyperlipidemia is defined as the presence of either hypertriglyceridemia or hypercholesterolemia, which could cause atherosclerosis. Although hyperlipidemia can be treated by hypolipidemic drugs, they are limited due to lack of effectiveness and safety. Previous studies demonstrated that xanthorrhizol (XNT) isolated from Curcuma xanthorrhizza Roxb. reduced the levels of free fatty acid and triglyceride in vivo. However, its ability to inhibit cholesterol uptake in HT29 colon cells and adipogenesis in 3T3-L1 cells are yet to be reported. In this study, XNT purified from centrifugal TLC demonstrated 98.3% purity, indicating it could be an alternative purification method. The IC50 values of XNT were 30.81 ± 0.78 μg/mL in HT29 cells and 35.07 ± 0.24 μg/mL in 3T3-L1 adipocytes, respectively. Cholesterol uptake inhibition study using HT29 colon cells showed that XNT (15 μg/mL) significantly inhibited the fluorescent cholesterol analogue NBD uptake by up to 27 ± 3.1% relative to control. On the other hand, higher concentration of XNT (50 μg/mL) significantly suppressed the growth of 3T3-L1 adipocytes (5.9 ± 0.58%) compared to 3T3-L1 preadipocytes (81.31 ± 0.55%). XNT was found to impede adipogenesis of 3T3-L1 adipocytes in a dose-dependent manner from 3.125 to 12.5 μg/mL, where 12.5 μg/mL significantly suppressed 36.13 ± 2.1% of lipid accumulation. We postulate that inhibition of cholesterol uptake, adipogenesis, preadipocyte and adipocyte number may be utilized as treatment modalities to reduce the prevalence of lipidemia. To conclude, XNT could be a potential hypolipidemic agent to improve cardiovascular health in the future. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

  19. Scaling up debris-flow experiments on a centrifuge

    Science.gov (United States)

    Hung, C.; Capart, H.; Crone, T. J.; Grinspum, E.; Hsu, L.; Kaufman, D.; Li, L.; Ling, H.; Reitz, M. D.; Smith, B.; Stark, C. P.

    2013-12-01

    Boundary forces generated by debris flows can be powerful enough to erode bedrock and cause considerable damage to infrastructure during runout. Formulation of an erosion-rate law for debris flows is therefore a high priority, and it makes sense to build such a law around laboratory experiments. However, running experiments big enough to generate realistic boundary forces is a logistical challenge to say the least [1]. One alternative is to run table-top simulations with unnaturally weak but fast-eroding pseudo-bedrock, another is to extrapolate from micro-erosion of natural substrates driven by unnaturally weak impacts; hybrid-scale experiments have also been conducted [2]. Here we take a different approach in which we scale up granular impact forces by running our experiments under enhanced gravity in a geotechnical centrifuge [3]. Using a 40cm-diameter rotating drum [2] spun at up to 100g, we generate debris flows with an effective depth of over several meters. By varying effective gravity from 1g to 100g we explore the scaling of granular flow forces and the consequent bed and wall erosion rates. The velocity and density structure of these granular flows is monitored using laser sheets, high-speed video, and particle tracking [4], and the progressive erosion of the boundary surfaces is measured by laser scanning. The force structures and their fluctuations within the granular mass and at the boundaries are explored with contact dynamics numerical simulations that mimic the lab experimental conditions [5]. In this presentation we summarize these results and discuss how they can contribute to the formulation of debris-flow erosion law. [1] Major, J. J. (1997), Journal of Geology 105: 345-366, doi:10.1086/515930 [2] Hsu, L. (2010), Ph.D. thesis, University of California, Berkeley [3] Brucks, A., et al (2007), Physical Review E 75, 032301, doi:10.1103/PhysRevE.75.032301 [4] Spinewine, B., et al (2011), Experiments in Fluids 50: 1507-1525, doi: 10.1007/s00348

  20. Conocimiento de las normas de tráfico en función de la edad y de la importancia para la seguridad vial / Knowledge of Traffic Rules According to the Age and the Importance for Road Safety

    Directory of Open Access Journals (Sweden)

    Cristina Vargas

    2012-12-01

    Full Text Available Un déficit en la memoria producido por la edad puede influir en el conocimiento de la normativa de tráfico. El presente estudio analiza las diferencias en el conocimiento de la normativa en función de la edad e importancia para la seguridad vial. Participaron 300 personas (18-75 años. Se elaboró un cuestionario de conocimiento sobre normativa de tráfico, según la importancia que desempeñan para la seguridad vial (poco importantes, importantes y muy importantes. En general, el conocimiento de los conductores sobre la normativa de tráfico fue pobre. Contrario a lo esperado, el rendimiento de los conductores mayores no siempre fue inferior al de los otros grupos de edad, presentando mejores resultados en preguntas poco importantes y muy importantes.

  1. Improved Recovery and Identification of Membrane Proteins from Rat Hepatic Cells using a Centrifugal Proteomic Reactor*

    Science.gov (United States)

    Zhou, Hu; Wang, Fangjun; Wang, Yuwei; Ning, Zhibin; Hou, Weimin; Wright, Theodore G.; Sundaram, Meenakshi; Zhong, Shumei; Yao, Zemin; Figeys, Daniel

    2011-01-01

    Despite their importance in many biological processes, membrane proteins are underrepresented in proteomic analysis because of their poor solubility (hydrophobicity) and often low abundance. We describe a novel approach for the identification of plasma membrane proteins and intracellular microsomal proteins that combines membrane fractionation, a centrifugal proteomic reactor for streamlined protein extraction, protein digestion and fractionation by centrifugation, and high performance liquid chromatography-electrospray ionization-tandem MS. The performance of this approach was illustrated for the study of the proteome of ER and Golgi microsomal membranes in rat hepatic cells. The centrifugal proteomic reactor identified 945 plasma membrane proteins and 955 microsomal membrane proteins, of which 63 and 47% were predicted as bona fide membrane proteins, respectively. Among these proteins, >800 proteins were undetectable by the conventional in-gel digestion approach. The majority of the membrane proteins only identified by the centrifugal proteomic reactor were proteins with ≥2 transmembrane segments or proteins with high molecular mass (e.g. >150 kDa) and hydrophobicity. The improved proteomic reactor allowed the detection of a group of endocytic and/or signaling receptor proteins on the plasma membrane, as well as apolipoproteins and glycerolipid synthesis enzymes that play a role in the assembly and secretion of apolipoprotein B100-containing very low density lipoproteins. Thus, the centrifugal proteomic reactor offers a new analytical tool for structure and function studies of membrane proteins involved in lipid and lipoprotein metabolism. PMID:21749988

  2. Effects of centrifugation on transmembrane water loss from normal and pathologic erythrocytes

    Energy Technology Data Exchange (ETDEWEB)

    Kaperonis, A.A.; Chien, S.

    1989-02-01

    Plasma /sup 125/I-albumin was used as a marker of extracellular dilution in order to study the effect of high-speed centrifugation on transmembrane water distribution in several types of human red cells, including normal (AA), hemoglobin variants (beta A, AS, SC, beta S, and SS), and those from patients with hereditary spherocytosis. SS and AA erythrocytes were also examined for changes in intracellular hemoglobin concentration of three different density fractions and with increasing duration of spin. The minimum force and duration of centrifugation required to impair water permeability were found to vary with the red cell type, the anticoagulant used (heparin or EDTA), the initial hematocrit of the sample centrifuged, as well as among the individual erythrocyte fractions within the same sample. When subjecting pathologic erythrocytes to high-speed centrifugation, the /sup 125/I-albumin dilution technique can be used to determine whether the centrifugation procedure has led to an artifactual red cell water loss and to correct for this when it does occur. An abnormal membrane susceptibility to mechanical stress was demonstrated in erythrocytes from patients with hereditary spherocytosis and several hemoglobinopathies.

  3. Aerodynamic Optimization Design of a Multistage Centrifugal Steam Turbine and Its Off-Design Performance Analysis

    Directory of Open Access Journals (Sweden)

    Hui Li

    2017-01-01

    Full Text Available Centrifugal turbine which has less land occupation, simple structure, and high aerodynamic efficiency is suitable to be used as small to medium size steam turbines or waste heat recovery plant. In this paper, one-dimensional design of a multistage centrifugal steam turbine was performed by using in-house one-dimensional aerodynamic design program. In addition, three-dimensional numerical simulation was also performed in order to analyze design and off-design aerodynamic performance of the proposed centrifugal steam turbine. The results exhibit reasonable flow field and smooth streamline; the aerodynamic performance of the designed turbine meets our initial expectations. These results indicate that the one-dimensional aerodynamic design program is reliable and effective. The off-design aerodynamic performance of centrifugal steam turbine was analyzed, and the results show that the mass flow increases with the decrease of the pressure ratio at a constant speed, until the critical mass flow is reached. The efficiency curve with the pressure ratio has an optimum efficiency point. And the pressure ratio of the optimum efficiency agrees well with that of the one-dimensional design. The shaft power decreases as the pressure ratio increases at a constant speed. Overall, the centrifugal turbine has a wide range and good off-design aerodynamic performance.

  4. Concentration of Cryptosporidium, microsporidia and other water-borne pathogens by continuous separation channel centrifugation.

    Science.gov (United States)

    Borchardt, M A; Spencer, S K

    2002-01-01

    The aim of this study was to determine the effectiveness of continuous separation channel centrifugation for concentrating water-borne pathogens of various taxa and sizes. Cryptosporidium parvum oocysts, Giardia lamblia cysts, Encephalitozoon intestinalis spores and Escherichia coli were seeded into different water matrices at densities ranging from 5 to 10 000 organisms l(-1) and recovered using continuous separation channel centrifugation. All pathogens were enumerated on membrane filters using microscopy. Recovery efficiencies were usually > 90%. Oocyst recovery did not vary with source water turbidity or with centrifuge flow rate up to 250 ml min(-1). Based on excystation, this concentration method did not alter oocyst viability. Continuous separation channel centrifugation is an effective means of concentrating water-borne pathogens. Methods are needed for detecting pathogens in drinking water to ensure public health. The first step for any pathogen detection procedure is concentration. However, this step has been problematic because recovery efficiencies of conventional methods, like filtration, are often low and variable, which may lead to false negatives. Continuous separation channel centrifugation can simultaneously concentrate multiple pathogens as small as 1 microm with high and reproducible efficiency in a variety of water matrices.

  5. A novel centrifuge for animal physiological researches in hypergravity and variable gravity forces

    Science.gov (United States)

    Kumei, Yasuhiro; Hasegawa, Katsuya; Inoue, Katarzyna; Zeredo, . Jorge; Kimiya Narikiyo, .; Maezawa, Yukio; Yuuki Watanabe, .; Aou, Shuji

    2012-07-01

    Understanding the physiological responses to altered gravitational environments is essential for space exploration and long-term human life in space. Currently available centrifuges restrict experimentation due to limited space for laboratory equipments. We developed a medium-sized disc-type centrifuge to conduct ground-based studies on animal physiological response to hypergravity and variable gravity forces, which features the following advantages: 1) It enables simultaneous examination into the effects of various gravity levels including rotation control. 2) Beside the constant G force, variable G forces (delta-G) can be loaded to generate gravitational acceleration and deceleration. 3) Multiple imaging techniques can be used, such as high-speed video (16 channels wireless) and photography, X-ray, and infra-red imaging. 4) Telemetry is available on the disc table of the centrifuge through 128-channel analog and 32-channel digital signals, with sampling rate of 100 kHz for 2 hours. Our dynamic-balanced centrifuge can hold payloads of 600 kg that enable experimentation on various models of living organisms, from cells to animals and plants. We use this novel centrifuge for neurochemical and neurophysiological approaches such as microdialysis and telemetrical recording of neuronal activity in the rat brain. Financial supports from JSPS to K. Hasegawa (2011) and from JAXA to Y. Kumei (2011).

  6. Prediction and Reduction of Aerodynamic Noise of the Multiblade Centrifugal Fan

    Directory of Open Access Journals (Sweden)

    Shuiqing Zhou

    2014-08-01

    Full Text Available An aerodynamic and aeroacoustic investigation of the multiblade centrifugal fan is proposed in this paper, and a hybrid technique of combining flow field calculation and acoustic analysis is applied to solve the aeroacoustic problem of multiblade centrifugal fan. The unsteady flow field of the multiblade centrifugal fan is predicted by solving the incompressible Reynolds-averaged Navier-Stokes (RANS equations with conventional computing techniques for fluid dynamics. The principal noise source induced is extracted from the calculation of the flow field by using acoustic principles, and the modeled sources on inner and outer surfaces of the volute are calculated with multiregional boundary element method (BEM. Through qualitative analysis, the sound pressure amplitude distribution of the multiblade centrifugal fan in near field is given and the sound pressure level (SPL spectrum diagram of monitoring points in far field is obtained. Based on the analysis results, the volute tongue structure is adjusted and then a low-noise design for the centrifugal fan is proposed. The comparison of noise tests shows the noise reduction of improved fan model is more obvious, which is in good agreement with the prediction using the hybrid techniques.

  7. A Stability Enhancement Method for Centrifugal Compressors using Active Control Casing Treatment System

    Science.gov (United States)

    Zhao, Yuanyang; Xiao, Jun; Li, Liansheng; Yang, Qichao; Liu, Guangbin; Wang, Le

    2015-08-01

    The centrifugal compressors are widely used in many fields. When the centrifugal compressors operate at the edge of the surge line, the compressor will be unstable. In addition, if the centrifugal compressor runs at this situation long time, the damage will be occurred on compressor. There are some kinds of method to improve and enlarge the range of the centrifugal compressors, such as inlet guide vane, and casing treatment. For casing treatment method, some structures have been researched, such as holed recirculation, basic slot casing treatment and groove casing treatment. All these researches are the passive methods. This paper present a new stability enhancement method based Active Control Casing Treatment (ACCT). All parts of this new method are introduced in detail. The control strategy of the system is mentioned in the paper. As a research sample, a centrifugal compressor having this system is researched using CFD method. The study focuses on the effect of the active control system on the impeller flow. The vortex in impeller is changed by the active control system. And this leads to the suppression of the extension of vortex blockage in impeller and to contribute to the enhancement of the compressor operating range.

  8. Centrifugal Pump Effect on Average Particle Diameter of Oil-Water Emulsion

    Science.gov (United States)

    Morozova, A.; Eskin, A.

    2017-11-01

    In this paper we review the process of oil-water emulsion particles fragmentation in a turbulent flow created by a centrifugal pump. We examined the influence of time necessary for oil-water emulsion preparation on the particle size of oil products and the dependence of a centrifugal pump emulsifying capacity on the initial emulsion dispersion. The investigated emulsion contained the brand fuel oil M-100 and tap water; it was sprayed with a nozzle in a gas-water flare. After preparation of the emulsion, the centrifugal pump was turned on and the emulsion samples were taken before and after the pump passing in 15, 30 and 45 minutes of spraying. To determine the effect the centrifugal pump has on the dispersion of the oil-water emulsion, the mean particle diameter of the emulsion particles was determined by the optical and microscopic method before and after the pump passing. A dispersion analysis of the particles contained in the emulsion was carried out by a laser diffraction analyzer. By analyzing the pictures of the emulsion samples, it was determined that after the centrifugal pump operation a particle size of oil products decreases. This result is also confirmed by the distribution of the obtained analyzer where the content of fine particles with a diameter less than 10 μm increased from 12% to 23%. In case of increasing emulsion preparation time, a particle size of petroleum products also decreases.

  9. Current and Past Strategies for Bacterial Culture in Clinical Microbiology

    Science.gov (United States)

    Lagier, Jean-Christophe; Edouard, Sophie; Pagnier, Isabelle; Mediannikov, Oleg; Drancourt, Michel

    2015-01-01

    SUMMARY A pure bacterial culture remains essential for the study of its virulence, its antibiotic susceptibility, and its genome sequence in order to facilitate the understanding and treatment of caused diseases. The first culture conditions empirically varied incubation time, nutrients, atmosphere, and temperature; culture was then gradually abandoned in favor of molecular methods. The rebirth of culture in clinical microbiology was prompted by microbiologists specializing in intracellular bacteria. The shell vial procedure allowed the culture of new species of Rickettsia. The design of axenic media for growing fastidious bacteria such as Tropheryma whipplei and Coxiella burnetii and the ability of amoebal coculture to discover new bacteria constituted major advances. Strong efforts associating optimized culture media, detection methods, and a microaerophilic atmosphere allowed a dramatic decrease of the time of Mycobacterium tuberculosis culture. The use of a new versatile medium allowed an extension of the repertoire of archaea. Finally, to optimize the culture of anaerobes in routine bacteriology laboratories, the addition of antioxidants in culture media under an aerobic atmosphere allowed the growth of strictly anaerobic species. Nevertheless, among usual bacterial pathogens, the development of axenic media for the culture of Treponema pallidum or Mycobacterium leprae remains an important challenge that the patience and innovations of cultivators will enable them to overcome. PMID:25567228

  10. Current and past strategies for bacterial culture in clinical microbiology.

    Science.gov (United States)

    Lagier, Jean-Christophe; Edouard, Sophie; Pagnier, Isabelle; Mediannikov, Oleg; Drancourt, Michel; Raoult, Didier

    2015-01-01

    A pure bacterial culture remains essential for the study of its virulence, its antibiotic susceptibility, and its genome sequence in order to facilitate the understanding and treatment of caused diseases. The first culture conditions empirically varied incubation time, nutrients, atmosphere, and temperature; culture was then gradually abandoned in favor of molecular methods. The rebirth of culture in clinical microbiology was prompted by microbiologists specializing in intracellular bacteria. The shell vial procedure allowed the culture of new species of Rickettsia. The design of axenic media for growing fastidious bacteria such as Tropheryma whipplei and Coxiella burnetii and the ability of amoebal coculture to discover new bacteria constituted major advances. Strong efforts associating optimized culture media, detection methods, and a microaerophilic atmosphere allowed a dramatic decrease of the time of Mycobacterium tuberculosis culture. The use of a new versatile medium allowed an extension of the repertoire of archaea. Finally, to optimize the culture of anaerobes in routine bacteriology laboratories, the addition of antioxidants in culture media under an aerobic atmosphere allowed the growth of strictly anaerobic species. Nevertheless, among usual bacterial pathogens, the development of axenic media for the culture of Treponema pallidum or Mycobacterium leprae remains an important challenge that the patience and innovations of cultivators will enable them to overcome. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

  11. Nutritional and mineral contents of honey extracted by centrifugation and pressed processes.

    Science.gov (United States)

    Kadri, Samir Moura; Zaluski, Rodrigo; Orsi, Ricardo de Oliveira

    2017-03-01

    In this study, wild honey samples extracted by two different methods (centrifugation and pressed processing) were characterized and compared based on their physicochemical, and nutritional properties, macro- and micro-mineral contents, and pollen counts. Twelve colonies of Africanized Apis mellifera were used; six honey samples were obtained by centrifugation and six by honeycomb press. All physicochemical parameters of honey samples (moisture, pH, total acidity, ash, dry matter, and qualitative absence of hydroxymethylfurfural) were within the limits established by EU legislation, and all parameters in pressed honey were superior (phoney. The quantity of pollen in pressed honey samples was 5.6-fold higher than in centrifuged samples. Pressed honey, can be marked as a differentiated product with a higher mineral content and several nutritional properties. Copyright © 2016 Elsevier Ltd. All rights reserved.

  12. Single-step fabrication of quantum funnels via centrifugal colloidal casting of nanoparticle films.

    KAUST Repository

    Kim, Jin Young

    2015-07-13

    Centrifugal casting of composites and ceramics has been widely employed to improve the mechanical and thermal properties of functional materials. This powerful method has yet to be deployed in the context of nanoparticles--yet size-effect tuning of quantum dots is among their most distinctive and application-relevant features. Here we report the first gradient nanoparticle films to be constructed in a single step. By creating a stable colloid of nanoparticles that are capped with electronic-conduction-compatible ligands we were able to leverage centrifugal casting for thin-films devices. This new method, termed centrifugal colloidal casting, is demonstrated to form films in a bandgap-ordered manner with efficient carrier funnelling towards the lowest energy layer. We constructed the first quantum-gradient photodiode to be formed in a single deposition step and, as a result of the gradient-enhanced electric field, experimentally measured the highest normalized detectivity of any colloidal quantum dot photodetector.

  13. Optimization and Analysis of Centrifugal Pump considering Fluid-Structure Interaction

    Science.gov (United States)

    Hu, Sanbao

    2014-01-01

    This paper presents the optimization of vibrations of centrifugal pump considering fluid-structure interaction (FSI). A set of centrifugal pumps with various blade shapes were studied using FSI method, in order to investigate the transient vibration performance. The Kriging model, based on the results of the FSI simulations, was established to approximate the relationship between the geometrical parameters of pump impeller and the root mean square (RMS) values of the displacement response at the pump bearing block. Hence, multi-island genetic algorithm (MIGA) has been implemented to minimize the RMS value of the impeller displacement. A prototype of centrifugal pump has been manufactured and an experimental validation of the optimization results has been carried out. The comparison among results of Kriging surrogate model, FSI simulation, and experimental test showed a good consistency of the three approaches. Finally, the transient mechanical behavior of pump impeller has been investigated using FSI method based on the optimized geometry parameters of pump impeller. PMID:25197690

  14. Single-step fabrication of quantum funnels via centrifugal colloidal casting of nanoparticle films

    Science.gov (United States)

    Kim, Jin Young; Adinolfi, Valerio; Sutherland, Brandon R.; Voznyy, Oleksandr; Kwon, S. Joon; Kim, Tae Wu; Kim, Jeongho; Ihee, Hyotcherl; Kemp, Kyle; Adachi, Michael; Yuan, Mingjian; Kramer, Illan; Zhitomirsky, David; Hoogland, Sjoerd; Sargent, Edward H.

    2015-01-01

    Centrifugal casting of composites and ceramics has been widely employed to improve the mechanical and thermal properties of functional materials. This powerful method has yet to be deployed in the context of nanoparticles—yet size–effect tuning of quantum dots is among their most distinctive and application-relevant features. Here we report the first gradient nanoparticle films to be constructed in a single step. By creating a stable colloid of nanoparticles that are capped with electronic-conduction-compatible ligands we were able to leverage centrifugal casting for thin-films devices. This new method, termed centrifugal colloidal casting, is demonstrated to form films in a bandgap-ordered manner with efficient carrier funnelling towards the lowest energy layer. We constructed the first quantum-gradient photodiode to be formed in a single deposition step and, as a result of the gradient-enhanced electric field, experimentally measured the highest normalized detectivity of any colloidal quantum dot photodetector. PMID:26165185

  15. Damages on pumps and systems the handbook for the operation of centrifugal pumps

    CERN Document Server

    Merkle, Thomas

    2014-01-01

    Damage on Pumps and Systems. The Handbook for the Operation of Centrifugal Pumps offers a combination of the theoretical basics and practical experience for the operation of circulation pumps in the engineering industry. Centrifugal pumps and systems are extremely vulnerable to damage from a variety of causes, but the resulting breakdown can be prevented by ensuring that these pumps and systems are operated properly. This book provides a total overview of operating centrifugal pumps, including condition monitoring, preventive maintenance, life cycle costs, energy savings and economic aspects. Extra emphasis is given to the potential damage to these pumps and systems, and what can be done to prevent breakdown. Addresses specific issues about pumping of metal chips, sand, abrasive dust and other solids in fluidsEmphasis on economic and efficiency aspects of predictive maintenance and condition monitoring Uses life cycle costs (LCC) to evaluate and calculate the costs of pumping systems

  16. [Concordance between the zinc sulphate flotation and centrifugal sedimentation methods for the diagnosis of intestinal parasites].

    Science.gov (United States)

    Inês, Elizabete De Jesus; Pacheco, Flavia Thamiris Figueiredo; Pinto, Milena Carneiro; Mendes, Patrícia Silva de Almeida; Da Costa-Ribeiro, Hugo; Soares, Neci Matos; Teixeira, Márcia Cristina Aquino

    2016-12-01

    The diagnosis of intestinal parasitic infections depends on the parasite load, the specific gravity density of the parasite eggs, oocysts or cysts, and the density and viscosity of flotation or sedimentation medium where faeces are processed. To evaluate the concordance between zinc sulphate flotation and centrifugal sedimentation in the recovery of parasites in faecal samples of children. Faecal samples of 330 children from day care centers were evaluated by zinc sulphate flotation and centrifugal sedimentation techniques. The frequencies of detection of parasites by each method were determined and the agreement between the diagnostic techniques was evaluated using the kappa index, with 95% confidence intervals. The faecal flotation in zinc sulphate diagnosed significantly more cases of Trichuris trichiura infection when compared to centrifugal sedimentation (39/330; 11.8% vs. 13/330; 3.9%, psedimentation process.

  17. Influence of Prewhirl Regulation by Inlet Guide Vanes on Cavitation Performance of a Centrifugal Pump

    Directory of Open Access Journals (Sweden)

    Lei Tan

    2014-02-01

    Full Text Available The influence of prewhirl regulation by inlet guide vanes (IGVs on a centrifugal pump performance is investigated experimentally and numerically. The experimental results show that IGVs can obviously change the head and increase the efficiency of the tested centrifugal pump over a wide range of flow rates. Although the cavitation performance is degraded, the variation of the cavitation critical point is less than 0.5 m. Movement of the computed three-dimensional streamlines in suction pipe and impeller are analyzed in order to reveal the mechanism how the IGVs realize the prewhirl regulation. The calculated results show that the influence of IGVs on the cavitation performance of centrifugal pump is limited by a maximum total pressure drop of 1777 Pa, about 7.6% of the total pressure at the suction pipe inlet for a prewhirl angle of 24°.

  18. Single-step fabrication of quantum funnels via centrifugal colloidal casting of nanoparticle films

    Science.gov (United States)

    Kim, Jin Young; Adinolfi, Valerio; Sutherland, Brandon R.; Voznyy, Oleksandr; Kwon, S. Joon; Kim, Tae Wu; Kim, Jeongho; Ihee, Hyotcherl; Kemp, Kyle; Adachi, Michael; Yuan, Mingjian; Kramer, Illan; Zhitomirsky, David; Hoogland, Sjoerd; Sargent, Edward H.

    2015-07-01

    Centrifugal casting of composites and ceramics has been widely employed to improve the mechanical and thermal properties of functional materials. This powerful method has yet to be deployed in the context of nanoparticles--yet size-effect tuning of quantum dots is among their most distinctive and application-relevant features. Here we report the first gradient nanoparticle films to be constructed in a single step. By creating a stable colloid of nanoparticles that are capped with electronic-conduction-compatible ligands we were able to leverage centrifugal casting for thin-films devices. This new method, termed centrifugal colloidal casting, is demonstrated to form films in a bandgap-ordered manner with efficient carrier funnelling towards the lowest energy layer. We constructed the first quantum-gradient photodiode to be formed in a single deposition step and, as a result of the gradient-enhanced electric field, experimentally measured the highest normalized detectivity of any colloidal quantum dot photodetector.

  19. The effect of centrifugation speed and time on pre-analytical platelet activation

    DEFF Research Database (Denmark)

    Söderström, Anna Cecilia; Nybo, Mads; Nielsen, Christian

    2016-01-01

    BACKGROUND: The results of laboratory analyses are affected by pre-analytical variables, and in particular can platelets be activated by shear handling stress and secrete granular substances. We therefore evaluated the effect of centrifugation speed and time on pre-analytical platelet activation....... METHODS: Citrate- and EDTA-anticoagulated blood from healthy volunteers were centrifuged at 80-10,000 g for 5-15 min to prepare plasma and platelet-rich plasma. Pre-analytical platelet activation was assessed by flow cytometric measurement of platelet P-selectin (CD62p) expression. Blood cell counts, mean...... of platelets expressing P-selectin in citrate- and EDTA-plasma centrifuged at 2000 g for 10 min were 43% [interquartile range (IQR), 38%-53%] and 56% (IQR, 31%-78%), respectively (p=0.82). Platelet-rich plasma prepared at 100-250 g for 10 min had significantly lower platelet P-selectin expression (11%-15%), p...

  20. Root resistance to cavitation is accurately measured using a centrifuge technique.

    Science.gov (United States)

    Pratt, R B; MacKinnon, E D; Venturas, M D; Crous, C J; Jacobsen, A L

    2015-02-01

    Plants transport water under negative pressure and this makes their xylem vulnerable to cavitation. Among plant organs, root xylem is often highly vulnerable to cavitation due to water stress. The use of centrifuge methods to study organs, such as roots, that have long vessels are hypothesized to produce erroneous estimates of cavitation resistance due to the presence of open vessels through measured samples. The assumption that roots have long vessels may be premature since data for root vessel length are sparse; moreover, recent studies have not supported the existence of a long-vessel artifact for stems when a standard centrifuge technique was used. We examined resistance to cavitation estimated using a standard centrifuge technique and compared these values with native embolism measurements for roots of seven woody species grown in a common garden. For one species we also measured vulnerability using single-vessel air injection. We found excellent agreement between root native embolism and the levels of embolism measured using a centrifuge technique, and with air-seeding estimates from single-vessel injection. Estimates of cavitation resistance measured from centrifuge curves were biologically meaningful and were correlated with field minimum water potentials, vessel diameter (VD), maximum xylem-specific conductivity (Ksmax) and vessel length. Roots did not have unusually long vessels compared with stems; moreover, root vessel length was not correlated to VD or to the vessel length of stems. These results suggest that root cavitation resistance can be accurately and efficiently measured using a standard centrifuge method and that roots are highly vulnerable to cavitation. The role of root cavitation resistance in determining drought tolerance of woody species deserves further study, particularly in the context of climate change. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  1. Cost/performance comparison between pulse columns and centrifugal contactors designed to process Clinch River Breeder Reactor fuel

    Energy Technology Data Exchange (ETDEWEB)

    Ciucci, J.A. Jr.

    1983-12-01

    A comparison between pulse columns and centrifugal contactors was made to determine which type of equipment was more advantageous for use in the primary decontamination cycle of a remotely operated fuel reprocessing plant. Clinch River Breeder Reactor (CRBR) fuel was chosen as the fuel to be processed in the proposed 1 metric tonne/day reprocessing facility. The pulse columns and centrifugal contactors were compared on a performance and total cost basis. From this comparison, either the pulse columns or the centrifugal contactors will be recommended for use in a fuel reprocessing plant built to reprocess CRBR fuel. The reliability, solvent exposure to radiation, required time to reach steady state, and the total costs were the primary areas of concern for the comparison. The pulse column units were determined to be more reliable than the centrifugal contactors. When a centrifugal contactor motor fails, it can be remotely changed in less than one eight hour shift. Pulse columns expose the solvent to approximately five times as much radiation dose as the centrifugal contactor units; however, the proposed solvent recovery system adequately cleans the solvent for either case. The time required for pulse columns to reach steady state is many times longer than the time required for centrifugal contactors to reach steady state. The cost comparison between the two types of contacting equipment resulted in centrifugal contactors costing 85% of the total cost of pulse columns when the contactors were stacked on three levels in the module. If the centrifugal contactors were all positioned on the top level of a module with the unoccupied volume in the module occupied by other equipment, the centrifugal contactors cost is 66% of the total cost of pulse columns. Based on these results, centrifugal contactors are recommended for use in a remotely operated reprocessing plant built to reprocess CRBR fuel.

  2. Development of a Single Vial Kit Solution for Radiolabeling of 68Ga-DKFZ-PSMA-11 and Its Performance in Prostate Cancer Patients

    Directory of Open Access Journals (Sweden)

    Thomas Ebenhan

    2015-08-01

    Full Text Available Prostate-specific membrane antigen (PSMA, a type II glycoprotein, is highly expressed in almost all prostate cancers. By playing such a universal role in the disease, PSMA provides a target for diagnostic imaging of prostate cancer using positron emission tomography/computed tomography (PET/CT. The PSMA-targeting ligand Glu-NH-CO-NH-Lys-(Ahx-HBED-CC (DKFZ-PSMA-11 has superior imaging properties and allows for highly-specific complexation of the generator-based radioisotope Gallium-68 (68Ga. However, only module-based radiolabeling procedures are currently available. This study intended to develop a single vial kit solution to radiolabel buffered DKFZ-PSMA-11 with 68Ga. A 68Ge/68Ga-generator was utilized to yield 68GaCl3 and major aspects of the kit development were assessed, such as radiolabeling performance, quality assurance, and stability. The final product was injected into patients with prostate cancer for PET/CT imaging and the kit performance was evaluated on the basis of the expected biodistribution, lesion detection, and dose optimization. Kits containing 5 nmol DKFZ-PSMA-11 showed rapid, quantitative 68Ga-complexation and all quality measurements met the release criteria for human application. The increased precursor content did not compromise the ability of 68Ga-DKFZ-PSMA-11 PET/CT to detect primary prostate cancer and its advanced lymphatic- and metastatic lesions. The 68Ga-DKFZ-PSMA-11 kit is a robust, ready-to-use diagnostic agent in prostate cancer with high diagnostic performance.

  3. Solid-state chemiluminescence assay for ultrasensitive detection of antimony using on-vial immobilization of CdSe quantum dots combined with liquid-liquid-liquid microextraction.

    Science.gov (United States)

    Costas-Mora, Isabel; Romero, Vanesa; Lavilla, Isela; Bendicho, Carlos

    2013-07-25

    On-vial immobilized CdSe quantum dots (QDs) are applied for the first time as chemiluminescent probes for the detection of trace metal ions. Among 17 metal ions tested, inhibition of the chemiluminescence when CdSe QDs are oxidized by H2O2 was observed for Sb, Se and Cu. Liquid-liquid-liquid microextraction was implemented in order to improve the selectivity and sensitivity of the chemiluminescent assay. Factors influencing both the CdSe QDs/H2O2 chemiluminescent system and microextraction process were optimized for ultrasensitive detection of Sb(III) and total Sb. In order to investigate the mechanism by which Sb ions inhibit the chemiluminescence of the CdSe QDs/H2O2 system, atomic force microscopy (AFM), X-ray photoelectron spectroscopy (XPS), UV-vis absorption and fluorescence measurements were performed. The selection of the appropriate CdSe QDs capping ligand was found to be a critical issue. Immobilization of QDs caused the chemiluminescence signal to be enhanced by a factor of 100 as compared to experiments carried out with QDs dispersed in the bulk aqueous phase. Under optimized conditions, the detection limit was 6 ng L(-1) Sb and the repeatability expressed as relative standard deviation (N=7) was about 1.3%. An enrichment factor of 95 was achieved within only 3 min of microextraction. Several water samples including drinking, spring, and river waters were analyzed. The proposed method was validated against CRM NWTM-27.2 fortified lake water, and a recovery study was performed with different types of water samples. Sb recoveries ranged from 94 to 105%. A fast, miniaturized and relatively inexpensive assay for selective and sensitive detection of Sb(III) and total Sb in waters is accomplished. Copyright © 2013 Elsevier B.V. All rights reserved.

  4. Combination of solid phase extraction and in vial solid phase derivatization using a strong anion exchange disk for the determination of nerve agent markers.

    Science.gov (United States)

    Subramaniam, Raja; Astot, Crister; Nilsson, Calle; Ostin, Anders

    2009-11-27

    Alkylphosphonic acids (APAs) are degradation products and chemical markers of organophosphorous (OP) nerve agents (chemical warfare agents). Anion exchange disk-based solid phase extraction (SPE) has been combined with in vial solid phase derivatization (SPD) and GC-MS analysis for the determination of APAs in aqueous samples. The optimization of critical method parameters, such as the SPD reaction, was achieved using statistical experimental design and multivariate data analysis. The optimized method achieved quantitative recoveries in the range from 83% to 101% (n=13, RSD from 4% to 10%). The method was sensitive, with LODs in SIM mode of 0.14 ppb, and demonstrated excellent linearity with an average R(2)>or=0.99 over the concentration range of 0.07-1.4 ppm in full scan mode and from 0.14 ppb to 14 ppb in SIM mode. For forensic applications, aqueous samples containing APAs at concentrations exceeding 14 ppb were concentrated and target analytes were successfully identified by spectral library and retention index matching. Method robustness was evaluated using aqueous samples from the official OPCW Proficiency Test (round 19) and all APAs present in the sample were conclusively identified. The SPE disk retained the underivatized APAs in a stable condition for extended periods of time. No significant losses of APAs from the disk were observed over a 36-day period. Overall, the method is well suited to the qualitative and quantitative analysis of degradation markers of OP nerve agents in aqueous matrices with simplicity, a low risk of cross-contamination and trace level sensitivity.

  5. SISTEMA ADAPTATIVO DE CONTROL Y OPTIMIZACIÓN DEL TRÁFICO DE UN CORREDOR VIAL SEMAFORIZADO. APLICACIÓN A LA CIUDAD DE MEDELLÍN

    Directory of Open Access Journals (Sweden)

    MARGARITA JIMÉNEZ

    2011-01-01

    Full Text Available Son tres los aspectos fundamentales a tener en cuenta en el diseño de un sistema de control adaptativo. El primer aspecto está vinculado con la naturaleza del fenómeno vehicular. Éste, lejos está de poder ser enfocado desde la perspectiva de un modelo determinista. El segundo aspecto, es inherente con una realidad física; teniendo en cuenta que las redes viales, cualesquiera sea su diseño y/o constitución, soportan un flujo vehicular máximo y una densidad máxima definida por sus dimensiones, número de carriles y condiciones del tráfico. Todo prueba, que por más perfeccionado que resulte el sistema, no es posible mejorar el rendimiento del flujo vehicular por unidad de tiempo, más allá de las limitaciones físicas impuestas por el diseño de la vía y las normas de circulación. De otro lado, los costos iníciales de inversión más los costos de operación y los costos externos relacionados con la eficiencia en el flujo de tráfico constituyen un tercer factor a tener en cuenta como consecuencia de los dos anteriores. Así mismo, la magnitud del costo dependerá en gran parte del grado de inteligencia que se asigne sobre la estrategia a implementar, de la tecnología a utilizar en la detección y del sistema de comunicaciones.

  6. The Life Cycle of the Parasitic Crustacean, Lernanthropus latis Yamaguti, 1954 (Copepoda: Lernanthropidae), on Marine-Cultured Fish, Lates calcarifer, from Setiu Wetland, Terengganu

    OpenAIRE

    Nur Qamarina Abdul Khalid; Faizah Shaharoum-Harrison

    2014-01-01

    Parasitic crustaceans of Lernanthropus latis were isolated from the host, the seabass, Lates calcarifer, obtained from a cage culture in Setiu Wetland, Terengganu. The adult females with egg were kept alive in vials containing 20 mL of filtered seawater and incubated at 30°C. The eggs were monitored every hour and the hatching periods were recorded. Three developmental stages were observed, namely, nauplii I, nauplii II, and infective copepodid. The infective copepodids were then transferred ...

  7. Alumina matrix ceramic-nickel composites formed by centrifugal slip casting

    Directory of Open Access Journals (Sweden)

    Justyna Zygmuntowicz

    2015-12-01

    Full Text Available The paper is focused on the possibility of fabricating the alumina matrix ceramic-nickel composites with gradient concentration of metal particles. Centrifugal slip casting method was chosen for the composite fabrication. This method allows fabrication of the graded distribution of nickel particles in the hollow cylinder composites. The horizontal rotation axis was applied. The samples were characterized by XRD, SEM and quantitative description of the microstructure. The macroscopic as well as SEM observations of the prepared composites confirmed the gradient concentration of Ni particles in the composite materials. The application of the centrifugal slip casting method allows for the graded distribution of metal particles in the samples.

  8. Long ceramic-lined pipes produced by a centrifugal-thermit process

    Energy Technology Data Exchange (ETDEWEB)

    Odawara, O. (Dept. of Electronic Chemistry, Tokyo Institute of Technology, Nagatsuta, Midori-ku, Yokohama 227 (JP))

    1990-03-01

    Longer than 3-m ceramic-lined pipes can be produced by means of a thermit-reaction-induced process under the influence of a centrifugal force (centrifugal-thermit process). By igniting only a part of the reactant, the thermit reaction rapidly proceeds to provide a ceramic lining of homogeneous quality in the direction of the pipe length. As a result of the residual stress measurement of each layer forming the present ceramic-lined pipe, it is confirmed that the intermediate metal layer produced plays an important role in balancing the stress between the ceramic and outer pipe layers.

  9. A Turbidity Test Based Centrifugal Microfluidics Diagnostic System for Simultaneous Detection of HBV, HCV, and CMV

    Directory of Open Access Journals (Sweden)

    Hung-Cheng Chang

    2015-01-01

    Full Text Available This paper presents a LAMP- (loop-mediated isothermal amplification- based lab-on-disk optical system that allows the simultaneous detection of hepatitis B virus, hepatitis C virus, and cytomegalovirus. The various flow stages are controlled in the proposed system using different balance among centrifugal pumping, Coriolis pumping, and the capillary force. We have implemented a servo system for positioning and speed control for the heating and centrifugal pumping. We have also successfully employed a polymer light-emitting diode section for turbidity detection. The easy-to-use one-click system can perform diagnostics in less than 1 hour.

  10. Spectral analysis of surface waves method to assess shear wave velocity within centrifuge models

    Science.gov (United States)

    Murillo, Carol Andrea; Thorel, Luc; Caicedo, Bernardo

    2009-06-01

    The method of the spectral analysis of surface waves (SASW) is tested out on reduced scale centrifuge models, with a specific device, called the mini Falling Weight, developed for this purpose. Tests are performed on layered materials made of a mixture of sand and clay. The shear wave velocity VS determined within the models using the SASW is compared with the laboratory measurements carried out using the bender element test. The results show that the SASW technique applied to centrifuge testing is a relevant method to characterize VS near the surface.

  11. Centrifuge modelling of lateral displacement of buried pipelines; Modelagem fisica centrifuga de flambagem lateral de dutos

    Energy Technology Data Exchange (ETDEWEB)

    Oliveira, Jose Renato Moreira da Silva de; Almeida, Marcio de Souza Soares de; Marques, Maria Esther Soares; Almeida, Maria Cascao Ferreira de [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil). Coordenacao dos Programas de Pos-graduacao de Engenharia (COPPE); Costa, Alvaro Maia da [PETROBRAS, Rio de Janeiro, RJ (Brazil). Centro de Pesquisas (CENPES)

    2003-07-01

    This work discusses soil-structure interaction applied to the buckling phenomena of buried pipelines subjected to heated oil flow. A set of physical modelling tests on lateral buckling of pipelines buried on soft clay is presented using COPPE/UFRJ geotechnical centrifuge. A 1:30 pipeline model was moved side ward through a soft clay layer during centrifuge flight, varying the burial depth, in order to simulate the lateral buckling in plane strain condition. The results show different behaviour concerning horizontal and vertical forces measured at pipeline level due to soil reaction. (author)

  12. Cavitation performance and flow characteristic in a centrifugal pump with inlet guide vanes

    Science.gov (United States)

    Tan, L.; Zha, L.; Cao, S. L.; Wang, Y. C.; Gui, S. B.

    2015-01-01

    The influence of prewhirl regulation by inlet guide vanes (IGVs) on cavitation performance and flow characteristic in a centrifugal pump is investigated. At the impeller inlet, the streamlines are regulated by the IGVs, and the axial velocity distribution is also influenced by the IGVs. Due to the total pressure loss on the IGVs, the cavitation performance of the centrifugal pump degrades. The cavitation area in impeller with IGVs is larger than one without IGVs. The specify values of total pressure loss between the suction pipe inlet and impeller inlet for three cavitation conditions show that the IGVs will generate additional pressure loss, which is related to the IGVs angles and cavitation conditions.

  13. Centrifugal separation and equilibration dynamics in an electron-antiproton plasma

    CERN Document Server

    Andresen, G B; Baquero-Ruiz, Marcelo; Bertsche, William; Bowe, Paul D; Butler, Eoin; Cesar, Claudio L; Chapman, Steven; Charlton, Michael; Deller, A; Eriksson, S; Fajans, Joel; Friesen, Tim; Fujiwara, Makoto C; Gill, David R; Gutierrez, A; Hangst, Jeffrey S; Hardy, Walter N; Hayden, Michael E; Humphries, Andrew J; Hydomako, Richard; Jonsell, Svante; Madsen, Niels; Menary, Scott; Nolan, Paul; Olin, Art; Povilus, Alexander; Pusa, Petteri; Robicheaux, Francis; Sarid, Eli; Silveira, Daniel M; So, Chukman; Storey, James W; Thompson, Robert I; van der Werf, Dirk P; Wurtele, Jonathan S; Yamazaki, Yasunori

    2011-01-01

    Charges in cold, multiple-species, non-neutral plasmas separate radially by mass, forming centrifugally-separated states. Here, we report the first detailed measurements of such states in an electron-antiproton plasma, and the first observations of the separation dynamics in any centrifugally-separated system. While the observed equilibrium states are expected and in agreement with theory, the equilibration time is approximately constant over a wide range of parameters, a surprising and as yet unexplained result. Electron-antiproton plasmas play a crucial role in antihydrogen trapping experiments.

  14. Enrichment of bacteria samples by centrifugation improves the diagnosis of orthopaedics-related infections via real-time PCR amplification of the bacterial methicillin-resistance gene.

    Science.gov (United States)

    Tsuru, Arisa; Setoguchi, Takao; Kawabata, Naoya; Hirotsu, Masataka; Yamamoto, Takuya; Nagano, Satoshi; Yokouchi, Masahiro; Kakoi, Hironori; Kawamura, Hideki; Ishidou, Yasuhiro; Tanimoto, Akihide; Komiya, Setsuro

    2015-07-03

    To effectively treat orthopaedic infections by methicillin-resistant strains, an early diagnosis is necessary. Bacterial cultures and real-time polymerase chain reaction (PCR) have been used to define methicillin-resistant staphylococci. However, even when patients display clinical signs of infections, bacterial culture and real-time PCR often cannot confirm infection. The aim of this study was to prospectively compare the utility of real-time PCR for the mecA gene detection following centrifugation of human samples with suspected orthopaedic infections. In addition to the conventional real-time PCR method, we performed real-time PCR following centrifugation of the sample at 4,830×g for 10 min in a modified real-time PCR (M-PCR) method. We suspended cultured methicillin-resistant Staphylococcus aureus and generated standard dilution series for in vitro experiments. The in vitro detection sensitivity of the M-PCR method was approximately 5.06 times higher than that of the conventional real-time PCR method. We performed bacterial culture, pathological examination, real-time PCR, and M-PCR to examine the infectious fluids and tissues obtained from 36 surgical patients at our hospital. Of these, 20 patients who had undergone primary total hip arthroplasty were enrolled as negative controls. In addition, 15 patients were examined who were clinically confirmed to have an infection, including periprosthetic joint infection (eight patients), pyogenic spondylitis (two patients), infectious pseudoarthrosis (two patients), and after spine surgery (three patients). In one sample from a patient who developed infectious pseudoarthrosis and two samples from surgical site infections after spine surgery, the mecA gene was detected only by the M-PCR method. In one patient with infectious pseudoarthrosis, one patient with infection after arthroplasty, and two patients with purulent spondylitis, the detection sensitivity of the M-PCR method was increased compared with PCR (clinical

  15. Effect of Excess Gravitational Force on Cultured Myotubes in Vitro

    Directory of Open Access Journals (Sweden)

    Shigehiro Hashimoto

    2013-06-01

    Full Text Available An effect of an excess gravitational force on cultured myoblasts has been studied in an experimental system with centrifugal force in vitro. Mouse myoblasts (C2C12 were seeded on a culture dish of 35 mm diameter, and cultured in the Dulbecco's Modified Eagle's Medium until the sub-confluent condition. To apply the excess gravitational force on the cultured cells, the dish was set in a conventional centrifugal machine. Constant gravitational force was applied to the cultured cells for three hours. Variations were made on the gravitational force (6 G, 10 G, 100 G, 500 G, and 800 G with control of the rotational speed of the rotator in the centrifugal machine. Morphology of the cells was observed with a phasecontrast microscope for eight days. The experimental results show that the myotube thickens day by day after the exposure to the excess gravitational force field. The results also show that the higher excess gravitational force thickens myotubes. The microscopic study shows that myotubes thicken with fusion each other.

  16. Detection of bacterial metabolites through dynamic acquisition from surface enhanced raman spectroscopy substrates integtrated in a centrifugal microfluidic platform

    DEFF Research Database (Denmark)

    Durucan, Onur; Morelli, Lidia; Schmidt, Michael Stenbæk

    2015-01-01

    In this work we present a novel technology that combines the advantages of centrifugal microfluidics with dynamic in-situ Surface Enhanced Raman Spectroscopy (SERS) sensing. Our technology is based on an automated readout system that allows on-line SERS acquisition on a rotating centrifugal...

  17. Subjective estimates of G-load in centrifuge-based simulation and applications for G-cueing in Desdemona

    NARCIS (Netherlands)

    Correia Grácio, B.J.; Wentink, M.; Groen, E.; Bles, W.

    2009-01-01

    In centrifuge simulators pilots experience the G-forces and fast G-onsets encountered in the real fighter aircraft. The motion cueing principle that drives these simulators is based on creating G-forces by increasing the centripetal force of the centrifuge through a rotation of the simulator arm.

  18. The sensitivity of direct faecal examination, direct faecal flotation, modified centrifugal faecal flotation and centrifugal sedimentation/flotation in the diagnosis of canine spirocercosis

    Directory of Open Access Journals (Sweden)

    J. Christie

    2011-04-01

    Full Text Available Several faecal examination techniques have shown variable sensitivity in demonstrating Spirocerca lupi (S. lupi eggs. The objective of this study was to determine which faecal examination technique, including a novel modified centrifugal flotation technique, was most sensitive to diagnose spirocercosis. Ten coproscopic examinations were performed on faeces collected from 33 dogs confirmed endoscopically to have spirocercosis. The tests included a direct faecal examination, a faecal sedimentation/flotation test, 4 direct faecal flotations and 4 modified faecal centrifugal flotations. These latter 2 flotation tests utilised 4 different faecal flotation solutions:NaNO3 (SG 1.22,MgSO4 (SG 1.29,ZnSO4 (SG 1.30 and sugar (SG 1.27. The sensitivity of the tests ranged between 42 %and 67 %, with theNaNO3 solution showing the highest sensitivity in both the direct and modified-centrifugal flotations. The modified NaNO3 centrifugal method ranked 1st with the highest mean egg count (45.24±83, and was superior (i.e. higher egg count and significantly different (P< 0.05 compared with the routine saturated sugar,ZnSO4 andMgSO4 flotation methods. The routine NaNO3 flotation method was also superior and significantly different (P < 0.05 compared with the routine ZnSO4 andMgSO4 flotation methods. Fifteen per cent (n=5 of dogs had neoplastic oesophageal nodules and a further 18 % (n = 6 had both neoplastic and non-neoplastic nodules. S. lupi eggs were demonstrated in 40%of dogs with neoplastic nodules only and 72.9 % of the dogs with non-neoplastic nodules. The mean egg count in the non-neoplastic group (61 was statistically greater (P = 0.02 than that of the neoplastic group (1. The results show that faecal examination using a NaNO3 solution is the most sensitive in the diagnosis of spirocercosis. The modified centrifugal flotation faecal method using this solution has the highest egg count. The study also found that dogs with neoplastic nodules shed

  19. The Design Fabrication Installation & Evaluation of the Balance Probe Monitor for Large Centrifuges at a National Laboratory Facility.

    Energy Technology Data Exchange (ETDEWEB)

    Gallegos, Jonathan Michael [Univ. of Texas, Austin, TX (United States)

    2016-11-01

    Balance Probe Monitors were designed, fabricated, installed, and evaluated at Sandia National Laboratories (SNL) for the 22,600 g kg (50,000 g lb) direct drive electromotor driven large centrifuges. These centrifuges provide a high onset/decay rate g environment. The Balance Probe Monitor is physically located near a centrifuge’s Capacitance Probe, a crucial sensor for the centrifuge’s sustainability. The Balance Probe Monitor will validate operability of the centrifuge. Most importantly, it is used for triggering a kill switch under the condition that the centrifuge displacement value exceeds allowed tolerances. During operational conditions, the Capacitance Probe continuously detects the structural displacement of the centrifuge and an adjoining AccuMeasure 9000 translates this displacement into an output voltage.

  20. Performance Prediction of Centrifugal Compressor for Drop-In Testing Using Low Greenhouse Warming Potential Alternative Refrigerants and Performance Test Codes

    National Research Council Canada - National Science Library

    Joo Hoon Park; Youhwan Shin; Jin Taek Chung

    2017-01-01

    ...) alternative refrigerants are increasing. In this study, substitute refrigerants, R-1234ze (E) and R-1233zd (E), were used in the centrifugal compressor of an R-134a 2-stage centrifugal chiller with a fixed rotational speed...

  1. MODELING AND DESIGN STUDY USING HFC-236EA AS AN ALTERNATIVE REFRIGERANT IN A CENTRIFUGAL COMPRESSOR

    Science.gov (United States)

    The report gives results of an investigation of the operation of a centrifugal compressor--part of a chlorofluorocarbon (CFC)-114 chiller installation--with the new refrigerant hydrofluorocarbon (HFC)-236ea, a proposed alternative to CFC-114. A large set of CFC-236ea operating da...

  2. Effect of Perturbations in the Coriolis and Centrifugal Forces on the ...

    Indian Academy of Sciences (India)

    Jupiter on an asteroid. This enables many researchers to study the restricted prob- lem by taking into account the effects of small perturbations in the Coriolis and centrifugal forces radiation, oblateness and triaxiality of the bodies (Sharma and. Ishwar 1995; Szebehely 1967a; SubbaRao and Sharma 1975; Bhatnagar and ...

  3. System-level network simulation for robust centrifugal-microfluidic lab-on-a-chip systems.

    Science.gov (United States)

    Schwarz, I; Zehnle, S; Hutzenlaub, T; Zengerle, R; Paust, N

    2016-05-10

    Centrifugal microfluidics shows a clear trend towards a higher degree of integration and parallelization. This trend leads to an increase in the number and density of integrated microfluidic unit operations. The fact that all unit operations are processed by the same common spin protocol turns higher integration into higher complexity. To allow for efficient development anyhow, we introduce advanced lumped models for network simulations in centrifugal microfluidics. These models consider the interplay of centrifugal and Euler pressures, viscous dissipation, capillary pressures and pneumatic pressures. The simulations are fast and simple to set up and allow for the precise prediction of flow rates as well as switching and valving events. During development, channel and chamber geometry variations due to manufacturing tolerances can be taken into account as well as pipetting errors, variations of contact angles, compliant chamber walls and temperature variations in the processing device. As an example of considering these parameters during development, we demonstrate simulation based robustness analysis for pneumatic siphon valving in centrifugal microfluidics. Subsequently, the influence of liquid properties on pumping and valving is studied for four liquids relevant for biochemical analysis, namely, water (large surface tension), blood plasma (large contact angle hysteresis), ethanol/water (highly wetting) and glycerine/water (highly viscous). In a second example, we derive a spin protocol to attain a constant flow rate under varying pressure conditions. Both examples show excellent agreement with experimental validations.

  4. Reflection of centrifugal pumps maintenance; Reflexiones sobre el mantenimiento de bombas centrifugas

    Energy Technology Data Exchange (ETDEWEB)

    Mozos Fernandez, V.

    2010-07-01

    The aim of this work is to prove that is not necessary a deep and complex knowledge to manage the centrifugal pumps maintenance. According to the author, only deep but single technical knowledge about causes of breakdowns in the different and simple component parts of the pumps, are required. (Author)

  5. Rapid prototyping of centrifugal microfluidic modules for point of care blood testing

    CSIR Research Space (South Africa)

    Madzivhandila, Phophi

    2016-11-01

    Full Text Available We present modular centrifugal microfluidic devices that enable a series of blood tests to be performed towards a full blood count. The modular approach allows for rapid prototyping of device components in a generic format to complete different...

  6. PIV Measurements and CFD computations of secondary flow in a centrifugal pump impeller (061104)

    NARCIS (Netherlands)

    Westra, R.W.; Broersma, L.; van Andel, Koen; Kruyt, Nicolaas P.

    2010-01-01

    Two-dimensional particle image velocimetry measurements and three-dimensional computational fluid dynamics (CFD) analyses have been performed on the steady velocity field inside the shrouded impeller of a low specific-speed centrifugal pump operating with a vaneless diffuser. Flow rates ranging from

  7. Synthesis and refining of sunflower biodiesel in a cascade of continuous centrifugal contactor separators

    NARCIS (Netherlands)

    Bin Abu Ghazali, Yusuf; van Ulden, Wouter; van de Bovenkamp, Hendrik; Teddy, T; Picchioni, Francesco; Manurung, Robert; Heeres, Hero J.

    The synthesis of fatty acid methyl esters (FAME) from sunflower oil and methanol was studied in a continuous centrifugal contactor separator (CCCS) using sodium methoxide as the catalyst. The effect of relevant process variables like oil and methanol flow rate, rotational speed and catalyst

  8. Finite element calculations and experimental verification of the unsteady potential flow in a centrifugal volute pump

    NARCIS (Netherlands)

    Badie, R.; Badie, R.; Jonker, Jan B.; van den Braembussche, R.A.

    1994-01-01

    In this paper we present a finite-element-based methode for the calculation of the unsteady potential flow in rotor/stator configurations. A numerical algorithm was developed to calculate the two-dimensional flow through a centrifugal volute pump, taking into account the width variation of the

  9. Analysis on Energy Conversion of Screw Centrifugal Pump in Impeller Domain Based on Profile Lines

    Directory of Open Access Journals (Sweden)

    Hui Quan

    2013-01-01

    Full Text Available In order to study the power capability of impeller and energy conversion mechanism of screw centrifugal pump, the methods of theoretical analysis and numerical simulation by computational fluid dynamics theory (CFD were adopted, specifically discussing the conditions of internal flow such as velocity, pressure, and concentration. When the medium is sand-water two-phase flow and dividing the rim of the lines and wheel lines of screw centrifugal pump to segments to analyze energy conversion capabilities which along the impeller profile lines with the dynamic head and hydrostatic head changer, the results show that the energy of fluid of the screw centrifugal pump is provided by helical segment, and the helical segment of the front of the impeller has played the role of multilevel increasing energy; the sand-water two phases move at different speeds because the different force field and the impeller propeller and centrifugal effect. As liquid phase is the primary phase, the energy conversion is mainly up to the change of liquid energy, the solid phase flows under the wrapped action of liquid, and solid energy is carried out through liquid indirectly.

  10. Studies on the chemistry of element 104 with the centrifuge system SISAK-3

    Energy Technology Data Exchange (ETDEWEB)

    Eberhardt, K.; Kratz, J.V.; Mendel, M.; Naehler, A.; Trautmann, N.; Wiehl, N. [Mainz Univ. (Germany); Alstadt, J.; Omtvedt, J.P. [Oslo Univ. (Norway); Malmbeck, R.; Skarnemark, G.; Wierczinski, B. [Chalmers Univ. of Technology, Goeteborg (Sweden); Eichler, B.; Gaeggeler, H.W.; Jost, D.T.; Tuerler, A. [Paul Scherrer Inst. (PSI), Villigen (Switzerland)

    1997-09-01

    The centrifuge system SISAK-3 combined with a detector for the measurement of {alpha}-particles and spontaneous fission (SF) fragments in a flowing organic liquid has been applied to study the chemical behaviour of element 104 produced in the reaction {sup 248}Cm({sup 18}O,5n){sup 261}104. (author) 2 figs., 2 refs.

  11. Predictability of rotating stall and surge in a centrifugal compressor stage with dynamic simulations

    NARCIS (Netherlands)

    González Díez, N.; Smeulers, J.P.M.; Tapinassi, L.; Scotti del Greco, A.; Toni, L.

    2014-01-01

    A testing campaign performed on a centrifugal compressor test-loop showed that multiple areas of stable operation existed that were not expected. It was shown during the tests that after a first region of instability at low flow rates, a second stable region would appear at even lower flow rates.

  12. Experimental testing of centrifugal pump: small and medium sized enterprise product

    Science.gov (United States)

    Ismail, R.; Paddiyatu, F.; Khafidh, M.; Nugroho, S.; Sugiyanto, S.; Jamari, J.

    2014-06-01

    This paper reports the experimental testing for centrifugal pump for fisherman ship, manufactured by small and medium sized enterprises in Central Java Province, Indonesia. The research covers material analysis, component observation, endurance and vibration test. Six centrifugal pumps are tested and three main pump components are discussed: shaft, bearings and seals. The results show that the material of the shaft is predicted to support and transmit the load from the engine to impeller. The problem found in the tolerance and geometry accuracy of the shaft which causes difficulties during assembling process, excessive wear and leakage during testing. From the endurance and vibration test, the ball bearings fail and lock the shaft due to the fatigue on the rolling elements and raceways. The oil seal and water seal also fail in maintaining the oil and water in the chamber and induce the unlubricated system for the ball bearings. Some suggestions are delivered to improve the product quality of the centrifugal pump. A good quality of the centrifugal pump for fishermen ship and long life span is expected to be produced by local SMEs to win the free trade competition in the Indonesian market.

  13. Comparison of rotordynamic fluid forces in axial inducers and centrifugal turbopump impellers

    Science.gov (United States)

    d'Agostino, Luca

    2016-05-01

    The paper illustrates and compares the results of the experimental campaigns carried out in the Cavitating Pump Rotordynamic Test Facility (CPRTF) at Alta, Italy, under ESA funding for the characterization of the lateral rotordynamic fluid forces acting on high-head axial inducers and centrifugal turbopump impellers for space propulsion applications. The configurations presented here refer to a three-bladed tapered-hub, variable-pitch, inducer (DAPROT3) and a single-stage centrifugal pump (VAMPIRE) with vaneless diffuser and single spiral volute. Both the centrifugal pump and the inducer have been designed by means of reduced order models specifically developed by the author and his collaborators for the geometric definition and performance prediction of this kind of hydraulic turbomachinery. Continuous spectra of the rotordynamic forces acting on the impellers as functions of the whirl frequency have been obtained by means of the novel technique recently developed and demonstrated at Alta. The influence of the rotor whirl motion, flow rate, cavitating conditions, and liquid temperature (thermal cavitation effects) on the rotordynamic fluid forces is illustrated and the observed differences in their behavior in axial inducers and centrifugal turbpumps are discussed and interpreted in the light of the outcome of recent cavitation visualization experiments carried out by the Chemical Propulsion Team at Alta.

  14. Statistical characteristics of suction pressure signals for a centrifugal pump under cavitating conditions

    Science.gov (United States)

    Li, Xiaojun; Yu, Benxu; Ji, Yucheng; Lu, Jiaxin; Yuan, Shouqi

    2017-02-01

    Centrifugal pumps are often used in operating conditions where they can be susceptible to premature failure. The cavitation phenomenon is a common fault in centrifugal pumps and is associated with undesired effects. Among the numerous cavitation detection methods, the measurement of suction pressure fluctuation is one of the most used methods to detect or diagnose the degree of cavitation in a centrifugal pump. In this paper, a closed loop was established to investigate the pump cavitation phenomenon, the statistical parameters for PDF (Probability Density Function), Variance and RMS (Root Mean Square) were used to analyze the relationship between the cavitation performance and the suction pressure signals during the development of cavitation. It is found that the statistical parameters used in this research are able to capture critical cavitation condition and cavitation breakdown condition, whereas difficult for the detection of incipient cavitation in the pump. At part-load conditions, the pressure fluctuations at the impeller inlet show more complexity than the best efficiency point (BEP). Amplitude of PDF values of suction pressure increased steeply when the flow rate dropped to 40 m3/h (the design flow rate was 60 m3/h). One possible reason is that the flow structure in the impeller channel promotes an increase of the cavitation intensity when the flow rate is reduced to a certain degree. This shows that it is necessary to find the relationship between the cavitation instabilities and flow instabilities when centrifugal pumps operate under part-load flow rates.

  15. Residual moisture reduction in coarse coal centrifuges using air purging. Part 3. Commercial scale trials

    Energy Technology Data Exchange (ETDEWEB)

    Condie, D.; Johnston, B.; Nicol, S.; Thomas, M.; Veal, C. [CSIRO, North Ryde, NSW (Australia). Division of Energy Technology

    2002-04-01

    Air purging is being developed as a new way of reducing the moisture content of coarse coal products from vibrating basket centrifuges. The process involves injecting a turbulent stream of high velocity air, via an air knife manifold, through the coal bed as it traverses the centrifuge basket. This paper describes the results obtained when the process was trialled in a commercial scale centrifuge. Five manifolds of different shapes and sizes were tested. The best results were achieved with units of square cross-section, located close to the outlet edge of the basket. Depending on air speed, product moisture was reduced by between 0.7 and 0.9 wt% at a confidence level exceeding 95%. The best results approached closely the 1.0 wt% moisture reduction target which had been adopted as the project objective. Air purging had no significant effect on the content or size distribution of the solids in the centrate. Increasing air speed led to larger moisture reductions. Higher air speeds were needed compared with previous pilot scale work probably due to the thicker beds encountered in the full scale centrifuge. Despite the higher air speed, the actual air usage (cfm/t of coal) was much more efficient at full scale, being less than half that at pilot scale.

  16. Centrifuge-induced neck and back pain in F-16 pilots

    DEFF Research Database (Denmark)

    Lange, Britt; Nielsen, René Tyranski; Skejø, Pernille Bro

    2013-01-01

    Early in their careers, as an important part of their training to become fighter pilots, pilots undergo centrifuge training in order to learn effective anti-G straining maneuvers (AGSM) and to test their G tolerance. The exposure of pilots, especially early in their careers, to training that coul...

  17. Centrifugal compressor fault diagnosis based on qualitative simulation and thermal parameters

    Science.gov (United States)

    Lu, Yunsong; Wang, Fuli; Jia, Mingxing; Qi, Yuanchen

    2016-12-01

    This paper concerns fault diagnosis of centrifugal compressor based on thermal parameters. An improved qualitative simulation (QSIM) based fault diagnosis method is proposed to diagnose the faults of centrifugal compressor in a gas-steam combined-cycle power plant (CCPP). The qualitative models under normal and two faulty conditions have been built through the analysis of the principle of centrifugal compressor. To solve the problem of qualitative description of the observations of system variables, a qualitative trend extraction algorithm is applied to extract the trends of the observations. For qualitative states matching, a sliding window based matching strategy which consists of variables operating ranges constraints and qualitative constraints is proposed. The matching results are used to determine which QSIM model is more consistent with the running state of system. The correct diagnosis of two typical faults: seal leakage and valve stuck in the centrifugal compressor has validated the targeted performance of the proposed method, showing the advantages of fault roots containing in thermal parameters.

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

    Science.gov (United States)

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

    1998-01-01

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

  19. Investigation on Flow-Induced Noise due to Backflow in Low Specific Speed Centrifugal Pumps

    Directory of Open Access Journals (Sweden)

    Qiaorui Si

    2013-01-01

    Full Text Available Flow-induced noise causes disturbances during the operation of centrifugal pumps and also affects their performance. The pumps often work at off-design conditions, mainly at part-load conditions, because of frequent changes in the pump device system. Consequently numerous unstable phenomena occur. In low specific speed centrifugal pumps the main disturbance is the inlet backflow, which is considered as one of the most important factors of flow-induced noise and vibration. In this study, a test rig of the flow-induced noise and vibration of the centrifugal pump was built to collect signals under various operating conditions. The three-dimensional unsteady flow of centrifugal pumps was calculated based on the Reynolds-averaged equations that resemble the shear stress transport (SST k-ω turbulence model. The results show that the blade passing frequency and shaft frequency are dominant in the spectrum of flow-induced noise, whereas the shaft component, amplitude value at shaft frequency, and peak frequencies around the shaft increase with decreasing flow. Through flow field analysis, the inlet backflow of the impeller occurs under 0.7 times the design flow. The pressure pulsation spectrum with backflow conditions validates the flow-induced noise findings. The velocity characteristics of the backflow zone at the inlet pipe were analyzed, and the dynamic characteristics of the backflow eddy during one impeller rotating period were simultaneously obtained by employing the backflow conditions. A flow visualization experiment was performed to confirm the numerical calculations.

  20. Study of the Effect of Centrifugal Force on Rotor Blade Icing Process

    Directory of Open Access Journals (Sweden)

    Zhengzhi Wang

    2017-01-01

    Full Text Available In view of the rotor icing problems, the influence of centrifugal force on rotor blade icing is investigated. A numerical simulation method of three-dimensional rotor blade icing is presented. Body-fitted grids around the rotor blade are generated using overlapping grid technology and rotor flow field characteristics are obtained by solving N-S equations. According to Eulerian two-phase flow, the droplet trajectories are calculated and droplet impingement characteristics are obtained. The mass and energy conservation equations of ice accretion model are established and a new calculation method of runback water mass based on shear stress and centrifugal force is proposed to simulate water flow and ice shape. The calculation results are compared with available experimental results in order to verify the correctness of the numerical simulation method. The influence of centrifugal force on rotor icing is calculated. The results show that the flow direction and distribution of liquid water on rotor surfaces change under the action of centrifugal force, which lead to the increasing of icing at the stagnation point and the decreasing of icing on both frozen limitations.